Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
diff --git a/fs/Kconfig b/fs/Kconfig
index 522469a..5f62e7e 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -268,6 +268,25 @@
is backwards compatible with JBD. It is safe to say N here.
However, if you really want to use the original JBD, say Y here.
+config BTRFS_FS
+ tristate "Btrfs filesystem (EXPERIMENTAL) Unstable disk format"
+ depends on EXPERIMENTAL
+ select LIBCRC32C
+ select ZLIB_INFLATE
+ select ZLIB_DEFLATE
+ help
+ Btrfs is a new filesystem with extents, writable snapshotting,
+ support for multiple devices and many more features.
+
+ Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET
+ FINALIZED. You should say N here unless you are interested in
+ testing Btrfs with non-critical data.
+
+ To compile this file system support as a module, choose M here. The
+ module will be called btrfs.
+
+ If unsure, say N.
+
endif # BLOCK
config DNOTIFY
diff --git a/fs/Makefile b/fs/Makefile
index d9f8afe..5fbb23d 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -121,4 +121,5 @@
obj-$(CONFIG_HPPFS) += hppfs/
obj-$(CONFIG_DEBUG_FS) += debugfs/
obj-$(CONFIG_OCFS2_FS) += ocfs2/
+obj-$(CONFIG_BTRFS_FS) += btrfs/
obj-$(CONFIG_GFS2_FS) += gfs2/
diff --git a/fs/btrfs/COPYING b/fs/btrfs/COPYING
new file mode 100644
index 0000000..ca442d3
--- /dev/null
+++ b/fs/btrfs/COPYING
@@ -0,0 +1,356 @@
+
+ NOTE! This copyright does *not* cover user programs that use kernel
+ services by normal system calls - this is merely considered normal use
+ of the kernel, and does *not* fall under the heading of "derived work".
+ Also note that the GPL below is copyrighted by the Free Software
+ Foundation, but the instance of code that it refers to (the Linux
+ kernel) is copyrighted by me and others who actually wrote it.
+
+ Also note that the only valid version of the GPL as far as the kernel
+ is concerned is _this_ particular version of the license (ie v2, not
+ v2.2 or v3.x or whatever), unless explicitly otherwise stated.
+
+ Linus Torvalds
+
+----------------------------------------
+
+ GNU GENERAL PUBLIC LICENSE
+ Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+ 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The licenses for most software are designed to take away your
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+License is intended to guarantee your freedom to share and change free
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+Foundation's software and to any other program whose authors commit to
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+the GNU Library General Public License instead.) You can apply it to
+your programs, too.
+
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+ GNU GENERAL PUBLIC LICENSE
+ TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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+ 0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
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+ 10. If you wish to incorporate parts of the Program into other free
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+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
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+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+
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+
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+
+ Gnomovision version 69, Copyright (C) year name of author
+ Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary. Here is a sample; alter the names:
+
+ Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+ `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+ <signature of Ty Coon>, 1 April 1989
+ Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs. If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library. If this is what you want to do, use the GNU Library General
+Public License instead of this License.
diff --git a/fs/btrfs/INSTALL b/fs/btrfs/INSTALL
new file mode 100644
index 0000000..16b45a5
--- /dev/null
+++ b/fs/btrfs/INSTALL
@@ -0,0 +1,48 @@
+Install Instructions
+
+Btrfs puts snapshots and subvolumes into the root directory of the FS. This
+directory can only be changed by btrfsctl right now, and normal filesystem
+operations do not work on it. The default subvolume is called 'default',
+and you can create files and directories in mount_point/default
+
+Btrfs uses libcrc32c in the kernel for file and metadata checksums. You need
+to compile the kernel with:
+
+CONFIG_LIBCRC32C=m
+
+libcrc32c can be static as well. Once your kernel is setup, typing make in the
+btrfs module sources will build against the running kernel. When the build is
+complete:
+
+modprobe libcrc32c
+insmod btrfs.ko
+
+The Btrfs utility programs require libuuid to build. This can be found
+in the e2fsprogs sources, and is usually available as libuuid or
+e2fsprogs-devel from various distros.
+
+Building the utilities is just make ; make install. The programs go
+into /usr/local/bin. The commands available are:
+
+mkfs.btrfs: create a filesystem
+
+btrfsctl: control program to create snapshots and subvolumes:
+
+ mount /dev/sda2 /mnt
+ btrfsctl -s new_subvol_name /mnt
+ btrfsctl -s snapshot_of_default /mnt/default
+ btrfsctl -s snapshot_of_new_subvol /mnt/new_subvol_name
+ btrfsctl -s snapshot_of_a_snapshot /mnt/snapshot_of_new_subvol
+ ls /mnt
+ default snapshot_of_a_snapshot snapshot_of_new_subvol
+ new_subvol_name snapshot_of_default
+
+ Snapshots and subvolumes cannot be deleted right now, but you can
+ rm -rf all the files and directories inside them.
+
+btrfsck: do a limited check of the FS extent trees.</li>
+
+debug-tree: print all of the FS metadata in text form. Example:
+
+ debug-tree /dev/sda2 >& big_output_file
+
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
new file mode 100644
index 0000000..d2cf5a5
--- /dev/null
+++ b/fs/btrfs/Makefile
@@ -0,0 +1,25 @@
+ifneq ($(KERNELRELEASE),)
+# kbuild part of makefile
+
+obj-$(CONFIG_BTRFS_FS) := btrfs.o
+btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
+ file-item.o inode-item.o inode-map.o disk-io.o \
+ transaction.o inode.o file.o tree-defrag.o \
+ extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
+ extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
+ ref-cache.o export.o tree-log.o acl.o free-space-cache.o zlib.o \
+ compression.o
+else
+
+# Normal Makefile
+
+KERNELDIR := /lib/modules/`uname -r`/build
+all:
+ $(MAKE) -C $(KERNELDIR) M=`pwd` CONFIG_BTRFS_FS=m modules
+
+modules_install:
+ $(MAKE) -C $(KERNELDIR) M=`pwd` modules_install
+clean:
+ $(MAKE) -C $(KERNELDIR) M=`pwd` clean
+
+endif
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
new file mode 100644
index 0000000..867eaf1
--- /dev/null
+++ b/fs/btrfs/acl.c
@@ -0,0 +1,352 @@
+/*
+ * Copyright (C) 2007 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/sched.h>
+
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "xattr.h"
+
+#ifdef CONFIG_FS_POSIX_ACL
+
+static void btrfs_update_cached_acl(struct inode *inode,
+ struct posix_acl **p_acl,
+ struct posix_acl *acl)
+{
+ spin_lock(&inode->i_lock);
+ if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED)
+ posix_acl_release(*p_acl);
+ *p_acl = posix_acl_dup(acl);
+ spin_unlock(&inode->i_lock);
+}
+
+static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
+{
+ int size;
+ const char *name;
+ char *value = NULL;
+ struct posix_acl *acl = NULL, **p_acl;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = POSIX_ACL_XATTR_ACCESS;
+ p_acl = &BTRFS_I(inode)->i_acl;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name = POSIX_ACL_XATTR_DEFAULT;
+ p_acl = &BTRFS_I(inode)->i_default_acl;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ spin_lock(&inode->i_lock);
+ if (*p_acl != BTRFS_ACL_NOT_CACHED)
+ acl = posix_acl_dup(*p_acl);
+ spin_unlock(&inode->i_lock);
+
+ if (acl)
+ return acl;
+
+
+ size = __btrfs_getxattr(inode, name, "", 0);
+ if (size > 0) {
+ value = kzalloc(size, GFP_NOFS);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ size = __btrfs_getxattr(inode, name, value, size);
+ if (size > 0) {
+ acl = posix_acl_from_xattr(value, size);
+ btrfs_update_cached_acl(inode, p_acl, acl);
+ }
+ kfree(value);
+ } else if (size == -ENOENT) {
+ acl = NULL;
+ btrfs_update_cached_acl(inode, p_acl, acl);
+ }
+
+ return acl;
+}
+
+static int btrfs_xattr_get_acl(struct inode *inode, int type,
+ void *value, size_t size)
+{
+ struct posix_acl *acl;
+ int ret = 0;
+
+ acl = btrfs_get_acl(inode, type);
+
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+ ret = posix_acl_to_xattr(acl, value, size);
+ posix_acl_release(acl);
+
+ return ret;
+}
+
+/*
+ * Needs to be called with fs_mutex held
+ */
+static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int ret, size = 0;
+ const char *name;
+ struct posix_acl **p_acl;
+ char *value = NULL;
+ mode_t mode;
+
+ if (acl) {
+ ret = posix_acl_valid(acl);
+ if (ret < 0)
+ return ret;
+ ret = 0;
+ }
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ mode = inode->i_mode;
+ ret = posix_acl_equiv_mode(acl, &mode);
+ if (ret < 0)
+ return ret;
+ ret = 0;
+ inode->i_mode = mode;
+ name = POSIX_ACL_XATTR_ACCESS;
+ p_acl = &BTRFS_I(inode)->i_acl;
+ break;
+ case ACL_TYPE_DEFAULT:
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EINVAL : 0;
+ name = POSIX_ACL_XATTR_DEFAULT;
+ p_acl = &BTRFS_I(inode)->i_default_acl;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ size = posix_acl_xattr_size(acl->a_count);
+ value = kmalloc(size, GFP_NOFS);
+ if (!value) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = posix_acl_to_xattr(acl, value, size);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = __btrfs_setxattr(inode, name, value, size, 0);
+
+out:
+ if (value)
+ kfree(value);
+
+ if (!ret)
+ btrfs_update_cached_acl(inode, p_acl, acl);
+
+ return ret;
+}
+
+static int btrfs_xattr_set_acl(struct inode *inode, int type,
+ const void *value, size_t size)
+{
+ int ret = 0;
+ struct posix_acl *acl = NULL;
+
+ if (value) {
+ acl = posix_acl_from_xattr(value, size);
+ if (acl == NULL) {
+ value = NULL;
+ size = 0;
+ } else if (IS_ERR(acl)) {
+ return PTR_ERR(acl);
+ }
+ }
+
+ ret = btrfs_set_acl(inode, acl, type);
+
+ posix_acl_release(acl);
+
+ return ret;
+}
+
+
+static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
+ void *value, size_t size)
+{
+ return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
+ void *value, size_t size)
+{
+ return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+int btrfs_check_acl(struct inode *inode, int mask)
+{
+ struct posix_acl *acl;
+ int error = -EAGAIN;
+
+ acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl) {
+ error = posix_acl_permission(inode, acl, mask);
+ posix_acl_release(acl);
+ }
+
+ return error;
+}
+
+/*
+ * btrfs_init_acl is already generally called under fs_mutex, so the locking
+ * stuff has been fixed to work with that. If the locking stuff changes, we
+ * need to re-evaluate the acl locking stuff.
+ */
+int btrfs_init_acl(struct inode *inode, struct inode *dir)
+{
+ struct posix_acl *acl = NULL;
+ int ret = 0;
+
+ /* this happens with subvols */
+ if (!dir)
+ return 0;
+
+ if (!S_ISLNK(inode->i_mode)) {
+ if (IS_POSIXACL(dir)) {
+ acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ }
+
+ if (!acl)
+ inode->i_mode &= ~current->fs->umask;
+ }
+
+ if (IS_POSIXACL(dir) && acl) {
+ struct posix_acl *clone;
+ mode_t mode;
+
+ if (S_ISDIR(inode->i_mode)) {
+ ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
+ if (ret)
+ goto failed;
+ }
+ clone = posix_acl_clone(acl, GFP_NOFS);
+ ret = -ENOMEM;
+ if (!clone)
+ goto failed;
+
+ mode = inode->i_mode;
+ ret = posix_acl_create_masq(clone, &mode);
+ if (ret >= 0) {
+ inode->i_mode = mode;
+ if (ret > 0) {
+ /* we need an acl */
+ ret = btrfs_set_acl(inode, clone,
+ ACL_TYPE_ACCESS);
+ }
+ }
+ }
+failed:
+ posix_acl_release(acl);
+
+ return ret;
+}
+
+int btrfs_acl_chmod(struct inode *inode)
+{
+ struct posix_acl *acl, *clone;
+ int ret = 0;
+
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+
+ if (!IS_POSIXACL(inode))
+ return 0;
+
+ acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+ if (IS_ERR(acl) || !acl)
+ return PTR_ERR(acl);
+
+ clone = posix_acl_clone(acl, GFP_KERNEL);
+ posix_acl_release(acl);
+ if (!clone)
+ return -ENOMEM;
+
+ ret = posix_acl_chmod_masq(clone, inode->i_mode);
+ if (!ret)
+ ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
+
+ posix_acl_release(clone);
+
+ return ret;
+}
+
+struct xattr_handler btrfs_xattr_acl_default_handler = {
+ .prefix = POSIX_ACL_XATTR_DEFAULT,
+ .get = btrfs_xattr_acl_default_get,
+ .set = btrfs_xattr_acl_default_set,
+};
+
+struct xattr_handler btrfs_xattr_acl_access_handler = {
+ .prefix = POSIX_ACL_XATTR_ACCESS,
+ .get = btrfs_xattr_acl_access_get,
+ .set = btrfs_xattr_acl_access_set,
+};
+
+#else /* CONFIG_FS_POSIX_ACL */
+
+int btrfs_acl_chmod(struct inode *inode)
+{
+ return 0;
+}
+
+int btrfs_init_acl(struct inode *inode, struct inode *dir)
+{
+ return 0;
+}
+
+int btrfs_check_acl(struct inode *inode, int mask)
+{
+ return 0;
+}
+
+#endif /* CONFIG_FS_POSIX_ACL */
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
new file mode 100644
index 0000000..4229450
--- /dev/null
+++ b/fs/btrfs/async-thread.c
@@ -0,0 +1,419 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/version.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+# include <linux/freezer.h>
+#include "async-thread.h"
+
+#define WORK_QUEUED_BIT 0
+#define WORK_DONE_BIT 1
+#define WORK_ORDER_DONE_BIT 2
+
+/*
+ * container for the kthread task pointer and the list of pending work
+ * One of these is allocated per thread.
+ */
+struct btrfs_worker_thread {
+ /* pool we belong to */
+ struct btrfs_workers *workers;
+
+ /* list of struct btrfs_work that are waiting for service */
+ struct list_head pending;
+
+ /* list of worker threads from struct btrfs_workers */
+ struct list_head worker_list;
+
+ /* kthread */
+ struct task_struct *task;
+
+ /* number of things on the pending list */
+ atomic_t num_pending;
+
+ unsigned long sequence;
+
+ /* protects the pending list. */
+ spinlock_t lock;
+
+ /* set to non-zero when this thread is already awake and kicking */
+ int working;
+
+ /* are we currently idle */
+ int idle;
+};
+
+/*
+ * helper function to move a thread onto the idle list after it
+ * has finished some requests.
+ */
+static void check_idle_worker(struct btrfs_worker_thread *worker)
+{
+ if (!worker->idle && atomic_read(&worker->num_pending) <
+ worker->workers->idle_thresh / 2) {
+ unsigned long flags;
+ spin_lock_irqsave(&worker->workers->lock, flags);
+ worker->idle = 1;
+ list_move(&worker->worker_list, &worker->workers->idle_list);
+ spin_unlock_irqrestore(&worker->workers->lock, flags);
+ }
+}
+
+/*
+ * helper function to move a thread off the idle list after new
+ * pending work is added.
+ */
+static void check_busy_worker(struct btrfs_worker_thread *worker)
+{
+ if (worker->idle && atomic_read(&worker->num_pending) >=
+ worker->workers->idle_thresh) {
+ unsigned long flags;
+ spin_lock_irqsave(&worker->workers->lock, flags);
+ worker->idle = 0;
+ list_move_tail(&worker->worker_list,
+ &worker->workers->worker_list);
+ spin_unlock_irqrestore(&worker->workers->lock, flags);
+ }
+}
+
+static noinline int run_ordered_completions(struct btrfs_workers *workers,
+ struct btrfs_work *work)
+{
+ unsigned long flags;
+
+ if (!workers->ordered)
+ return 0;
+
+ set_bit(WORK_DONE_BIT, &work->flags);
+
+ spin_lock_irqsave(&workers->lock, flags);
+
+ while(!list_empty(&workers->order_list)) {
+ work = list_entry(workers->order_list.next,
+ struct btrfs_work, order_list);
+
+ if (!test_bit(WORK_DONE_BIT, &work->flags))
+ break;
+
+ /* we are going to call the ordered done function, but
+ * we leave the work item on the list as a barrier so
+ * that later work items that are done don't have their
+ * functions called before this one returns
+ */
+ if (test_and_set_bit(WORK_ORDER_DONE_BIT, &work->flags))
+ break;
+
+ spin_unlock_irqrestore(&workers->lock, flags);
+
+ work->ordered_func(work);
+
+ /* now take the lock again and call the freeing code */
+ spin_lock_irqsave(&workers->lock, flags);
+ list_del(&work->order_list);
+ work->ordered_free(work);
+ }
+
+ spin_unlock_irqrestore(&workers->lock, flags);
+ return 0;
+}
+
+/*
+ * main loop for servicing work items
+ */
+static int worker_loop(void *arg)
+{
+ struct btrfs_worker_thread *worker = arg;
+ struct list_head *cur;
+ struct btrfs_work *work;
+ do {
+ spin_lock_irq(&worker->lock);
+ while(!list_empty(&worker->pending)) {
+ cur = worker->pending.next;
+ work = list_entry(cur, struct btrfs_work, list);
+ list_del(&work->list);
+ clear_bit(WORK_QUEUED_BIT, &work->flags);
+
+ work->worker = worker;
+ spin_unlock_irq(&worker->lock);
+
+ work->func(work);
+
+ atomic_dec(&worker->num_pending);
+ /*
+ * unless this is an ordered work queue,
+ * 'work' was probably freed by func above.
+ */
+ run_ordered_completions(worker->workers, work);
+
+ spin_lock_irq(&worker->lock);
+ check_idle_worker(worker);
+
+ }
+ worker->working = 0;
+ if (freezing(current)) {
+ refrigerator();
+ } else {
+ set_current_state(TASK_INTERRUPTIBLE);
+ spin_unlock_irq(&worker->lock);
+ if (!kthread_should_stop())
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ }
+ } while (!kthread_should_stop());
+ return 0;
+}
+
+/*
+ * this will wait for all the worker threads to shutdown
+ */
+int btrfs_stop_workers(struct btrfs_workers *workers)
+{
+ struct list_head *cur;
+ struct btrfs_worker_thread *worker;
+
+ list_splice_init(&workers->idle_list, &workers->worker_list);
+ while(!list_empty(&workers->worker_list)) {
+ cur = workers->worker_list.next;
+ worker = list_entry(cur, struct btrfs_worker_thread,
+ worker_list);
+ kthread_stop(worker->task);
+ list_del(&worker->worker_list);
+ kfree(worker);
+ }
+ return 0;
+}
+
+/*
+ * simple init on struct btrfs_workers
+ */
+void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max)
+{
+ workers->num_workers = 0;
+ INIT_LIST_HEAD(&workers->worker_list);
+ INIT_LIST_HEAD(&workers->idle_list);
+ INIT_LIST_HEAD(&workers->order_list);
+ spin_lock_init(&workers->lock);
+ workers->max_workers = max;
+ workers->idle_thresh = 32;
+ workers->name = name;
+ workers->ordered = 0;
+}
+
+/*
+ * starts new worker threads. This does not enforce the max worker
+ * count in case you need to temporarily go past it.
+ */
+int btrfs_start_workers(struct btrfs_workers *workers, int num_workers)
+{
+ struct btrfs_worker_thread *worker;
+ int ret = 0;
+ int i;
+
+ for (i = 0; i < num_workers; i++) {
+ worker = kzalloc(sizeof(*worker), GFP_NOFS);
+ if (!worker) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ INIT_LIST_HEAD(&worker->pending);
+ INIT_LIST_HEAD(&worker->worker_list);
+ spin_lock_init(&worker->lock);
+ atomic_set(&worker->num_pending, 0);
+ worker->task = kthread_run(worker_loop, worker,
+ "btrfs-%s-%d", workers->name,
+ workers->num_workers + i);
+ worker->workers = workers;
+ if (IS_ERR(worker->task)) {
+ kfree(worker);
+ ret = PTR_ERR(worker->task);
+ goto fail;
+ }
+
+ spin_lock_irq(&workers->lock);
+ list_add_tail(&worker->worker_list, &workers->idle_list);
+ worker->idle = 1;
+ workers->num_workers++;
+ spin_unlock_irq(&workers->lock);
+ }
+ return 0;
+fail:
+ btrfs_stop_workers(workers);
+ return ret;
+}
+
+/*
+ * run through the list and find a worker thread that doesn't have a lot
+ * to do right now. This can return null if we aren't yet at the thread
+ * count limit and all of the threads are busy.
+ */
+static struct btrfs_worker_thread *next_worker(struct btrfs_workers *workers)
+{
+ struct btrfs_worker_thread *worker;
+ struct list_head *next;
+ int enforce_min = workers->num_workers < workers->max_workers;
+
+ /*
+ * if we find an idle thread, don't move it to the end of the
+ * idle list. This improves the chance that the next submission
+ * will reuse the same thread, and maybe catch it while it is still
+ * working
+ */
+ if (!list_empty(&workers->idle_list)) {
+ next = workers->idle_list.next;
+ worker = list_entry(next, struct btrfs_worker_thread,
+ worker_list);
+ return worker;
+ }
+ if (enforce_min || list_empty(&workers->worker_list))
+ return NULL;
+
+ /*
+ * if we pick a busy task, move the task to the end of the list.
+ * hopefully this will keep things somewhat evenly balanced.
+ * Do the move in batches based on the sequence number. This groups
+ * requests submitted at roughly the same time onto the same worker.
+ */
+ next = workers->worker_list.next;
+ worker = list_entry(next, struct btrfs_worker_thread, worker_list);
+ atomic_inc(&worker->num_pending);
+ worker->sequence++;
+
+ if (worker->sequence % workers->idle_thresh == 0)
+ list_move_tail(next, &workers->worker_list);
+ return worker;
+}
+
+/*
+ * selects a worker thread to take the next job. This will either find
+ * an idle worker, start a new worker up to the max count, or just return
+ * one of the existing busy workers.
+ */
+static struct btrfs_worker_thread *find_worker(struct btrfs_workers *workers)
+{
+ struct btrfs_worker_thread *worker;
+ unsigned long flags;
+
+again:
+ spin_lock_irqsave(&workers->lock, flags);
+ worker = next_worker(workers);
+ spin_unlock_irqrestore(&workers->lock, flags);
+
+ if (!worker) {
+ spin_lock_irqsave(&workers->lock, flags);
+ if (workers->num_workers >= workers->max_workers) {
+ struct list_head *fallback = NULL;
+ /*
+ * we have failed to find any workers, just
+ * return the force one
+ */
+ if (!list_empty(&workers->worker_list))
+ fallback = workers->worker_list.next;
+ if (!list_empty(&workers->idle_list))
+ fallback = workers->idle_list.next;
+ BUG_ON(!fallback);
+ worker = list_entry(fallback,
+ struct btrfs_worker_thread, worker_list);
+ spin_unlock_irqrestore(&workers->lock, flags);
+ } else {
+ spin_unlock_irqrestore(&workers->lock, flags);
+ /* we're below the limit, start another worker */
+ btrfs_start_workers(workers, 1);
+ goto again;
+ }
+ }
+ return worker;
+}
+
+/*
+ * btrfs_requeue_work just puts the work item back on the tail of the list
+ * it was taken from. It is intended for use with long running work functions
+ * that make some progress and want to give the cpu up for others.
+ */
+int btrfs_requeue_work(struct btrfs_work *work)
+{
+ struct btrfs_worker_thread *worker = work->worker;
+ unsigned long flags;
+
+ if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
+ goto out;
+
+ spin_lock_irqsave(&worker->lock, flags);
+ atomic_inc(&worker->num_pending);
+ list_add_tail(&work->list, &worker->pending);
+
+ /* by definition we're busy, take ourselves off the idle
+ * list
+ */
+ if (worker->idle) {
+ spin_lock_irqsave(&worker->workers->lock, flags);
+ worker->idle = 0;
+ list_move_tail(&worker->worker_list,
+ &worker->workers->worker_list);
+ spin_unlock_irqrestore(&worker->workers->lock, flags);
+ }
+
+ spin_unlock_irqrestore(&worker->lock, flags);
+
+out:
+ return 0;
+}
+
+/*
+ * places a struct btrfs_work into the pending queue of one of the kthreads
+ */
+int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
+{
+ struct btrfs_worker_thread *worker;
+ unsigned long flags;
+ int wake = 0;
+
+ /* don't requeue something already on a list */
+ if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
+ goto out;
+
+ worker = find_worker(workers);
+ if (workers->ordered) {
+ spin_lock_irqsave(&workers->lock, flags);
+ list_add_tail(&work->order_list, &workers->order_list);
+ spin_unlock_irqrestore(&workers->lock, flags);
+ } else {
+ INIT_LIST_HEAD(&work->order_list);
+ }
+
+ spin_lock_irqsave(&worker->lock, flags);
+ atomic_inc(&worker->num_pending);
+ check_busy_worker(worker);
+ list_add_tail(&work->list, &worker->pending);
+
+ /*
+ * avoid calling into wake_up_process if this thread has already
+ * been kicked
+ */
+ if (!worker->working)
+ wake = 1;
+ worker->working = 1;
+
+ spin_unlock_irqrestore(&worker->lock, flags);
+
+ if (wake)
+ wake_up_process(worker->task);
+out:
+ return 0;
+}
diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h
new file mode 100644
index 0000000..31be4ed
--- /dev/null
+++ b/fs/btrfs/async-thread.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_ASYNC_THREAD_
+#define __BTRFS_ASYNC_THREAD_
+
+struct btrfs_worker_thread;
+
+/*
+ * This is similar to a workqueue, but it is meant to spread the operations
+ * across all available cpus instead of just the CPU that was used to
+ * queue the work. There is also some batching introduced to try and
+ * cut down on context switches.
+ *
+ * By default threads are added on demand up to 2 * the number of cpus.
+ * Changing struct btrfs_workers->max_workers is one way to prevent
+ * demand creation of kthreads.
+ *
+ * the basic model of these worker threads is to embed a btrfs_work
+ * structure in your own data struct, and use container_of in a
+ * work function to get back to your data struct.
+ */
+struct btrfs_work {
+ /*
+ * func should be set to the function you want called
+ * your work struct is passed as the only arg
+ *
+ * ordered_func must be set for work sent to an ordered work queue,
+ * and it is called to complete a given work item in the same
+ * order they were sent to the queue.
+ */
+ void (*func)(struct btrfs_work *work);
+ void (*ordered_func)(struct btrfs_work *work);
+ void (*ordered_free)(struct btrfs_work *work);
+
+ /*
+ * flags should be set to zero. It is used to make sure the
+ * struct is only inserted once into the list.
+ */
+ unsigned long flags;
+
+ /* don't touch these */
+ struct btrfs_worker_thread *worker;
+ struct list_head list;
+ struct list_head order_list;
+};
+
+struct btrfs_workers {
+ /* current number of running workers */
+ int num_workers;
+
+ /* max number of workers allowed. changed by btrfs_start_workers */
+ int max_workers;
+
+ /* once a worker has this many requests or fewer, it is idle */
+ int idle_thresh;
+
+ /* force completions in the order they were queued */
+ int ordered;
+
+ /* list with all the work threads. The workers on the idle thread
+ * may be actively servicing jobs, but they haven't yet hit the
+ * idle thresh limit above.
+ */
+ struct list_head worker_list;
+ struct list_head idle_list;
+
+ /*
+ * when operating in ordered mode, this maintains the list
+ * of work items waiting for completion
+ */
+ struct list_head order_list;
+
+ /* lock for finding the next worker thread to queue on */
+ spinlock_t lock;
+
+ /* extra name for this worker, used for current->name */
+ char *name;
+};
+
+int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work);
+int btrfs_start_workers(struct btrfs_workers *workers, int num_workers);
+int btrfs_stop_workers(struct btrfs_workers *workers);
+void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max);
+int btrfs_requeue_work(struct btrfs_work *work);
+#endif
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
new file mode 100644
index 0000000..0b2e623
--- /dev/null
+++ b/fs/btrfs/btrfs_inode.h
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_I__
+#define __BTRFS_I__
+
+#include "extent_map.h"
+#include "extent_io.h"
+#include "ordered-data.h"
+
+/* in memory btrfs inode */
+struct btrfs_inode {
+ /* which subvolume this inode belongs to */
+ struct btrfs_root *root;
+
+ /* the block group preferred for allocations. This pointer is buggy
+ * and needs to be replaced with a bytenr instead
+ */
+ struct btrfs_block_group_cache *block_group;
+
+ /* key used to find this inode on disk. This is used by the code
+ * to read in roots of subvolumes
+ */
+ struct btrfs_key location;
+
+ /* the extent_tree has caches of all the extent mappings to disk */
+ struct extent_map_tree extent_tree;
+
+ /* the io_tree does range state (DIRTY, LOCKED etc) */
+ struct extent_io_tree io_tree;
+
+ /* special utility tree used to record which mirrors have already been
+ * tried when checksums fail for a given block
+ */
+ struct extent_io_tree io_failure_tree;
+
+ /* held while inserting checksums to avoid races */
+ struct mutex csum_mutex;
+
+ /* held while inesrting or deleting extents from files */
+ struct mutex extent_mutex;
+
+ /* held while logging the inode in tree-log.c */
+ struct mutex log_mutex;
+
+ /* used to order data wrt metadata */
+ struct btrfs_ordered_inode_tree ordered_tree;
+
+ /* standard acl pointers */
+ struct posix_acl *i_acl;
+ struct posix_acl *i_default_acl;
+
+ /* for keeping track of orphaned inodes */
+ struct list_head i_orphan;
+
+ /* list of all the delalloc inodes in the FS. There are times we need
+ * to write all the delalloc pages to disk, and this list is used
+ * to walk them all.
+ */
+ struct list_head delalloc_inodes;
+
+ /* full 64 bit generation number, struct vfs_inode doesn't have a big
+ * enough field for this.
+ */
+ u64 generation;
+
+ /*
+ * transid of the trans_handle that last modified this inode
+ */
+ u64 last_trans;
+ /*
+ * transid that last logged this inode
+ */
+ u64 logged_trans;
+
+ /*
+ * trans that last made a change that should be fully fsync'd. This
+ * gets reset to zero each time the inode is logged
+ */
+ u64 log_dirty_trans;
+
+ /* total number of bytes pending delalloc, used by stat to calc the
+ * real block usage of the file
+ */
+ u64 delalloc_bytes;
+
+ /*
+ * the size of the file stored in the metadata on disk. data=ordered
+ * means the in-memory i_size might be larger than the size on disk
+ * because not all the blocks are written yet.
+ */
+ u64 disk_i_size;
+
+ /* flags field from the on disk inode */
+ u32 flags;
+
+ /*
+ * if this is a directory then index_cnt is the counter for the index
+ * number for new files that are created
+ */
+ u64 index_cnt;
+
+ struct inode vfs_inode;
+};
+
+static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
+{
+ return container_of(inode, struct btrfs_inode, vfs_inode);
+}
+
+static inline void btrfs_i_size_write(struct inode *inode, u64 size)
+{
+ inode->i_size = size;
+ BTRFS_I(inode)->disk_i_size = size;
+}
+
+
+#endif
diff --git a/fs/btrfs/compat.h b/fs/btrfs/compat.h
new file mode 100644
index 0000000..cd6598b
--- /dev/null
+++ b/fs/btrfs/compat.h
@@ -0,0 +1,24 @@
+#ifndef _COMPAT_H_
+#define _COMPAT_H_
+
+#define btrfs_drop_nlink(inode) drop_nlink(inode)
+#define btrfs_inc_nlink(inode) inc_nlink(inode)
+
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,27)
+static inline struct dentry *d_obtain_alias(struct inode *inode)
+{
+ struct dentry *d;
+
+ if (!inode)
+ return NULL;
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+
+ d = d_alloc_anon(inode);
+ if (!d)
+ iput(inode);
+ return d;
+}
+#endif
+
+#endif /* _COMPAT_H_ */
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
new file mode 100644
index 0000000..bfd1512
--- /dev/null
+++ b/fs/btrfs/compression.c
@@ -0,0 +1,618 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/bit_spinlock.h>
+#include <linux/version.h>
+#include <linux/pagevec.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "volumes.h"
+#include "ordered-data.h"
+#include "compat.h"
+#include "compression.h"
+#include "extent_io.h"
+#include "extent_map.h"
+
+struct compressed_bio {
+ /* number of bios pending for this compressed extent */
+ atomic_t pending_bios;
+
+ /* the pages with the compressed data on them */
+ struct page **compressed_pages;
+
+ /* inode that owns this data */
+ struct inode *inode;
+
+ /* starting offset in the inode for our pages */
+ u64 start;
+
+ /* number of bytes in the inode we're working on */
+ unsigned long len;
+
+ /* number of bytes on disk */
+ unsigned long compressed_len;
+
+ /* number of compressed pages in the array */
+ unsigned long nr_pages;
+
+ /* IO errors */
+ int errors;
+
+ /* for reads, this is the bio we are copying the data into */
+ struct bio *orig_bio;
+};
+
+static struct bio *compressed_bio_alloc(struct block_device *bdev,
+ u64 first_byte, gfp_t gfp_flags)
+{
+ struct bio *bio;
+ int nr_vecs;
+
+ nr_vecs = bio_get_nr_vecs(bdev);
+ bio = bio_alloc(gfp_flags, nr_vecs);
+
+ if (bio == NULL && (current->flags & PF_MEMALLOC)) {
+ while (!bio && (nr_vecs /= 2))
+ bio = bio_alloc(gfp_flags, nr_vecs);
+ }
+
+ if (bio) {
+ bio->bi_size = 0;
+ bio->bi_bdev = bdev;
+ bio->bi_sector = first_byte >> 9;
+ }
+ return bio;
+}
+
+/* when we finish reading compressed pages from the disk, we
+ * decompress them and then run the bio end_io routines on the
+ * decompressed pages (in the inode address space).
+ *
+ * This allows the checksumming and other IO error handling routines
+ * to work normally
+ *
+ * The compressed pages are freed here, and it must be run
+ * in process context
+ */
+static void end_compressed_bio_read(struct bio *bio, int err)
+{
+ struct extent_io_tree *tree;
+ struct compressed_bio *cb = bio->bi_private;
+ struct inode *inode;
+ struct page *page;
+ unsigned long index;
+ int ret;
+
+ if (err)
+ cb->errors = 1;
+
+ /* if there are more bios still pending for this compressed
+ * extent, just exit
+ */
+ if (!atomic_dec_and_test(&cb->pending_bios))
+ goto out;
+
+ /* ok, we're the last bio for this extent, lets start
+ * the decompression.
+ */
+ inode = cb->inode;
+ tree = &BTRFS_I(inode)->io_tree;
+ ret = btrfs_zlib_decompress_biovec(cb->compressed_pages,
+ cb->start,
+ cb->orig_bio->bi_io_vec,
+ cb->orig_bio->bi_vcnt,
+ cb->compressed_len);
+ if (ret)
+ cb->errors = 1;
+
+ /* release the compressed pages */
+ index = 0;
+ for (index = 0; index < cb->nr_pages; index++) {
+ page = cb->compressed_pages[index];
+ page->mapping = NULL;
+ page_cache_release(page);
+ }
+
+ /* do io completion on the original bio */
+ if (cb->errors) {
+ bio_io_error(cb->orig_bio);
+ } else
+ bio_endio(cb->orig_bio, 0);
+
+ /* finally free the cb struct */
+ kfree(cb->compressed_pages);
+ kfree(cb);
+out:
+ bio_put(bio);
+}
+
+/*
+ * Clear the writeback bits on all of the file
+ * pages for a compressed write
+ */
+static noinline int end_compressed_writeback(struct inode *inode, u64 start,
+ unsigned long ram_size)
+{
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long end_index = (start + ram_size - 1) >> PAGE_CACHE_SHIFT;
+ struct page *pages[16];
+ unsigned long nr_pages = end_index - index + 1;
+ int i;
+ int ret;
+
+ while(nr_pages > 0) {
+ ret = find_get_pages_contig(inode->i_mapping, index,
+ min_t(unsigned long,
+ nr_pages, ARRAY_SIZE(pages)), pages);
+ if (ret == 0) {
+ nr_pages -= 1;
+ index += 1;
+ continue;
+ }
+ for (i = 0; i < ret; i++) {
+ end_page_writeback(pages[i]);
+ page_cache_release(pages[i]);
+ }
+ nr_pages -= ret;
+ index += ret;
+ }
+ /* the inode may be gone now */
+ return 0;
+}
+
+/*
+ * do the cleanup once all the compressed pages hit the disk.
+ * This will clear writeback on the file pages and free the compressed
+ * pages.
+ *
+ * This also calls the writeback end hooks for the file pages so that
+ * metadata and checksums can be updated in the file.
+ */
+static void end_compressed_bio_write(struct bio *bio, int err)
+{
+ struct extent_io_tree *tree;
+ struct compressed_bio *cb = bio->bi_private;
+ struct inode *inode;
+ struct page *page;
+ unsigned long index;
+
+ if (err)
+ cb->errors = 1;
+
+ /* if there are more bios still pending for this compressed
+ * extent, just exit
+ */
+ if (!atomic_dec_and_test(&cb->pending_bios))
+ goto out;
+
+ /* ok, we're the last bio for this extent, step one is to
+ * call back into the FS and do all the end_io operations
+ */
+ inode = cb->inode;
+ tree = &BTRFS_I(inode)->io_tree;
+ cb->compressed_pages[0]->mapping = cb->inode->i_mapping;
+ tree->ops->writepage_end_io_hook(cb->compressed_pages[0],
+ cb->start,
+ cb->start + cb->len - 1,
+ NULL, 1);
+ cb->compressed_pages[0]->mapping = NULL;
+
+ end_compressed_writeback(inode, cb->start, cb->len);
+ /* note, our inode could be gone now */
+
+ /*
+ * release the compressed pages, these came from alloc_page and
+ * are not attached to the inode at all
+ */
+ index = 0;
+ for (index = 0; index < cb->nr_pages; index++) {
+ page = cb->compressed_pages[index];
+ page->mapping = NULL;
+ page_cache_release(page);
+ }
+
+ /* finally free the cb struct */
+ kfree(cb->compressed_pages);
+ kfree(cb);
+out:
+ bio_put(bio);
+}
+
+/*
+ * worker function to build and submit bios for previously compressed pages.
+ * The corresponding pages in the inode should be marked for writeback
+ * and the compressed pages should have a reference on them for dropping
+ * when the IO is complete.
+ *
+ * This also checksums the file bytes and gets things ready for
+ * the end io hooks.
+ */
+int btrfs_submit_compressed_write(struct inode *inode, u64 start,
+ unsigned long len, u64 disk_start,
+ unsigned long compressed_len,
+ struct page **compressed_pages,
+ unsigned long nr_pages)
+{
+ struct bio *bio = NULL;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct compressed_bio *cb;
+ unsigned long bytes_left;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ int page_index = 0;
+ struct page *page;
+ u64 first_byte = disk_start;
+ struct block_device *bdev;
+ int ret;
+
+ WARN_ON(start & ((u64)PAGE_CACHE_SIZE - 1));
+ cb = kmalloc(sizeof(*cb), GFP_NOFS);
+ atomic_set(&cb->pending_bios, 0);
+ cb->errors = 0;
+ cb->inode = inode;
+ cb->start = start;
+ cb->len = len;
+ cb->compressed_pages = compressed_pages;
+ cb->compressed_len = compressed_len;
+ cb->orig_bio = NULL;
+ cb->nr_pages = nr_pages;
+
+ bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
+
+ ret = btrfs_csum_file_bytes(root, inode, start, len);
+ BUG_ON(ret);
+
+ bio = compressed_bio_alloc(bdev, first_byte, GFP_NOFS);
+ bio->bi_private = cb;
+ bio->bi_end_io = end_compressed_bio_write;
+ atomic_inc(&cb->pending_bios);
+
+ /* create and submit bios for the compressed pages */
+ bytes_left = compressed_len;
+ for (page_index = 0; page_index < cb->nr_pages; page_index++) {
+ page = compressed_pages[page_index];
+ page->mapping = inode->i_mapping;
+ if (bio->bi_size)
+ ret = io_tree->ops->merge_bio_hook(page, 0,
+ PAGE_CACHE_SIZE,
+ bio, 0);
+ else
+ ret = 0;
+
+ page->mapping = NULL;
+ if (ret || bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) <
+ PAGE_CACHE_SIZE) {
+ bio_get(bio);
+
+ /*
+ * inc the count before we submit the bio so
+ * we know the end IO handler won't happen before
+ * we inc the count. Otherwise, the cb might get
+ * freed before we're done setting it up
+ */
+ atomic_inc(&cb->pending_bios);
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
+ BUG_ON(ret);
+
+ ret = btrfs_map_bio(root, WRITE, bio, 0, 1);
+ BUG_ON(ret);
+
+ bio_put(bio);
+
+ bio = compressed_bio_alloc(bdev, first_byte, GFP_NOFS);
+ bio->bi_private = cb;
+ bio->bi_end_io = end_compressed_bio_write;
+ bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
+ }
+ if (bytes_left < PAGE_CACHE_SIZE) {
+ printk("bytes left %lu compress len %lu nr %lu\n",
+ bytes_left, cb->compressed_len, cb->nr_pages);
+ }
+ bytes_left -= PAGE_CACHE_SIZE;
+ first_byte += PAGE_CACHE_SIZE;
+ cond_resched();
+ }
+ bio_get(bio);
+
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
+ BUG_ON(ret);
+
+ ret = btrfs_map_bio(root, WRITE, bio, 0, 1);
+ BUG_ON(ret);
+
+ bio_put(bio);
+ return 0;
+}
+
+static noinline int add_ra_bio_pages(struct inode *inode,
+ u64 compressed_end,
+ struct compressed_bio *cb)
+{
+ unsigned long end_index;
+ unsigned long page_index;
+ u64 last_offset;
+ u64 isize = i_size_read(inode);
+ int ret;
+ struct page *page;
+ unsigned long nr_pages = 0;
+ struct extent_map *em;
+ struct address_space *mapping = inode->i_mapping;
+ struct pagevec pvec;
+ struct extent_map_tree *em_tree;
+ struct extent_io_tree *tree;
+ u64 end;
+ int misses = 0;
+
+ page = cb->orig_bio->bi_io_vec[cb->orig_bio->bi_vcnt - 1].bv_page;
+ last_offset = (page_offset(page) + PAGE_CACHE_SIZE);
+ em_tree = &BTRFS_I(inode)->extent_tree;
+ tree = &BTRFS_I(inode)->io_tree;
+
+ if (isize == 0)
+ return 0;
+
+ end_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
+
+ pagevec_init(&pvec, 0);
+ while(last_offset < compressed_end) {
+ page_index = last_offset >> PAGE_CACHE_SHIFT;
+
+ if (page_index > end_index)
+ break;
+
+ rcu_read_lock();
+ page = radix_tree_lookup(&mapping->page_tree, page_index);
+ rcu_read_unlock();
+ if (page) {
+ misses++;
+ if (misses > 4)
+ break;
+ goto next;
+ }
+
+ page = alloc_page(mapping_gfp_mask(mapping) | GFP_NOFS);
+ if (!page)
+ break;
+
+ page->index = page_index;
+ /*
+ * what we want to do here is call add_to_page_cache_lru,
+ * but that isn't exported, so we reproduce it here
+ */
+ if (add_to_page_cache(page, mapping,
+ page->index, GFP_NOFS)) {
+ page_cache_release(page);
+ goto next;
+ }
+
+ /* open coding of lru_cache_add, also not exported */
+ page_cache_get(page);
+ if (!pagevec_add(&pvec, page))
+ __pagevec_lru_add(&pvec);
+
+ end = last_offset + PAGE_CACHE_SIZE - 1;
+ /*
+ * at this point, we have a locked page in the page cache
+ * for these bytes in the file. But, we have to make
+ * sure they map to this compressed extent on disk.
+ */
+ set_page_extent_mapped(page);
+ lock_extent(tree, last_offset, end, GFP_NOFS);
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, last_offset,
+ PAGE_CACHE_SIZE);
+ spin_unlock(&em_tree->lock);
+
+ if (!em || last_offset < em->start ||
+ (last_offset + PAGE_CACHE_SIZE > extent_map_end(em)) ||
+ (em->block_start >> 9) != cb->orig_bio->bi_sector) {
+ free_extent_map(em);
+ unlock_extent(tree, last_offset, end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ break;
+ }
+ free_extent_map(em);
+
+ if (page->index == end_index) {
+ char *userpage;
+ size_t zero_offset = isize & (PAGE_CACHE_SIZE - 1);
+
+ if (zero_offset) {
+ int zeros;
+ zeros = PAGE_CACHE_SIZE - zero_offset;
+ userpage = kmap_atomic(page, KM_USER0);
+ memset(userpage + zero_offset, 0, zeros);
+ flush_dcache_page(page);
+ kunmap_atomic(userpage, KM_USER0);
+ }
+ }
+
+ ret = bio_add_page(cb->orig_bio, page,
+ PAGE_CACHE_SIZE, 0);
+
+ if (ret == PAGE_CACHE_SIZE) {
+ nr_pages++;
+ page_cache_release(page);
+ } else {
+ unlock_extent(tree, last_offset, end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ break;
+ }
+next:
+ last_offset += PAGE_CACHE_SIZE;
+ }
+ if (pagevec_count(&pvec))
+ __pagevec_lru_add(&pvec);
+ return 0;
+}
+
+/*
+ * for a compressed read, the bio we get passed has all the inode pages
+ * in it. We don't actually do IO on those pages but allocate new ones
+ * to hold the compressed pages on disk.
+ *
+ * bio->bi_sector points to the compressed extent on disk
+ * bio->bi_io_vec points to all of the inode pages
+ * bio->bi_vcnt is a count of pages
+ *
+ * After the compressed pages are read, we copy the bytes into the
+ * bio we were passed and then call the bio end_io calls
+ */
+int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ struct extent_io_tree *tree;
+ struct extent_map_tree *em_tree;
+ struct compressed_bio *cb;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ unsigned long uncompressed_len = bio->bi_vcnt * PAGE_CACHE_SIZE;
+ unsigned long compressed_len;
+ unsigned long nr_pages;
+ unsigned long page_index;
+ struct page *page;
+ struct block_device *bdev;
+ struct bio *comp_bio;
+ u64 cur_disk_byte = (u64)bio->bi_sector << 9;
+ u64 em_len;
+ u64 em_start;
+ struct extent_map *em;
+ int ret;
+
+ tree = &BTRFS_I(inode)->io_tree;
+ em_tree = &BTRFS_I(inode)->extent_tree;
+
+ /* we need the actual starting offset of this extent in the file */
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree,
+ page_offset(bio->bi_io_vec->bv_page),
+ PAGE_CACHE_SIZE);
+ spin_unlock(&em_tree->lock);
+
+ cb = kmalloc(sizeof(*cb), GFP_NOFS);
+ atomic_set(&cb->pending_bios, 0);
+ cb->errors = 0;
+ cb->inode = inode;
+
+ cb->start = em->orig_start;
+ compressed_len = em->block_len;
+ em_len = em->len;
+ em_start = em->start;
+ free_extent_map(em);
+ em = NULL;
+
+ cb->len = uncompressed_len;
+ cb->compressed_len = compressed_len;
+ cb->orig_bio = bio;
+
+ nr_pages = (compressed_len + PAGE_CACHE_SIZE - 1) /
+ PAGE_CACHE_SIZE;
+ cb->compressed_pages = kmalloc(sizeof(struct page *) * nr_pages,
+ GFP_NOFS);
+ bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
+
+ for (page_index = 0; page_index < nr_pages; page_index++) {
+ cb->compressed_pages[page_index] = alloc_page(GFP_NOFS |
+ __GFP_HIGHMEM);
+ }
+ cb->nr_pages = nr_pages;
+
+ add_ra_bio_pages(inode, em_start + em_len, cb);
+
+ if (!btrfs_test_opt(root, NODATASUM) &&
+ !btrfs_test_flag(inode, NODATASUM)) {
+ btrfs_lookup_bio_sums(root, inode, cb->orig_bio);
+ }
+
+ /* include any pages we added in add_ra-bio_pages */
+ uncompressed_len = bio->bi_vcnt * PAGE_CACHE_SIZE;
+ cb->len = uncompressed_len;
+
+ comp_bio = compressed_bio_alloc(bdev, cur_disk_byte, GFP_NOFS);
+ comp_bio->bi_private = cb;
+ comp_bio->bi_end_io = end_compressed_bio_read;
+ atomic_inc(&cb->pending_bios);
+
+ for (page_index = 0; page_index < nr_pages; page_index++) {
+ page = cb->compressed_pages[page_index];
+ page->mapping = inode->i_mapping;
+ if (comp_bio->bi_size)
+ ret = tree->ops->merge_bio_hook(page, 0,
+ PAGE_CACHE_SIZE,
+ comp_bio, 0);
+ else
+ ret = 0;
+
+ page->mapping = NULL;
+ if (ret || bio_add_page(comp_bio, page, PAGE_CACHE_SIZE, 0) <
+ PAGE_CACHE_SIZE) {
+ bio_get(comp_bio);
+
+ ret = btrfs_bio_wq_end_io(root->fs_info, comp_bio, 0);
+ BUG_ON(ret);
+
+ /*
+ * inc the count before we submit the bio so
+ * we know the end IO handler won't happen before
+ * we inc the count. Otherwise, the cb might get
+ * freed before we're done setting it up
+ */
+ atomic_inc(&cb->pending_bios);
+
+ ret = btrfs_map_bio(root, READ, comp_bio, 0, 0);
+ BUG_ON(ret);
+
+ bio_put(comp_bio);
+
+ comp_bio = compressed_bio_alloc(bdev, cur_disk_byte,
+ GFP_NOFS);
+ comp_bio->bi_private = cb;
+ comp_bio->bi_end_io = end_compressed_bio_read;
+
+ bio_add_page(comp_bio, page, PAGE_CACHE_SIZE, 0);
+ }
+ cur_disk_byte += PAGE_CACHE_SIZE;
+ }
+ bio_get(comp_bio);
+
+ ret = btrfs_bio_wq_end_io(root->fs_info, comp_bio, 0);
+ BUG_ON(ret);
+
+ ret = btrfs_map_bio(root, READ, comp_bio, 0, 0);
+ BUG_ON(ret);
+
+ bio_put(comp_bio);
+ return 0;
+}
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
new file mode 100644
index 0000000..421f5b4
--- /dev/null
+++ b/fs/btrfs/compression.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_COMPRESSION_
+#define __BTRFS_COMPRESSION_
+
+int btrfs_zlib_decompress(unsigned char *data_in,
+ struct page *dest_page,
+ unsigned long start_byte,
+ size_t srclen, size_t destlen);
+int btrfs_zlib_compress_pages(struct address_space *mapping,
+ u64 start, unsigned long len,
+ struct page **pages,
+ unsigned long nr_dest_pages,
+ unsigned long *out_pages,
+ unsigned long *total_in,
+ unsigned long *total_out,
+ unsigned long max_out);
+int btrfs_zlib_decompress_biovec(struct page **pages_in,
+ u64 disk_start,
+ struct bio_vec *bvec,
+ int vcnt,
+ size_t srclen);
+void btrfs_zlib_exit(void);
+int btrfs_submit_compressed_write(struct inode *inode, u64 start,
+ unsigned long len, u64 disk_start,
+ unsigned long compressed_len,
+ struct page **compressed_pages,
+ unsigned long nr_pages);
+int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
+ int mirror_num, unsigned long bio_flags);
+#endif
diff --git a/fs/btrfs/crc32c.h b/fs/btrfs/crc32c.h
new file mode 100644
index 0000000..1eaf11d
--- /dev/null
+++ b/fs/btrfs/crc32c.h
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_CRC32C__
+#define __BTRFS_CRC32C__
+#include <asm/byteorder.h>
+#include <linux/crc32c.h>
+#include <linux/version.h>
+
+/* #define CONFIG_BTRFS_HW_SUM 1 */
+
+#ifdef CONFIG_BTRFS_HW_SUM
+#ifdef CONFIG_X86
+/*
+ * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal.
+ * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE)
+ * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at:
+ * http://www.intel.com/products/processor/manuals/
+ * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
+ * Volume 2A: Instruction Set Reference, A-M
+ */
+
+#include <asm/cpufeature.h>
+#include <asm/processor.h>
+
+#define X86_FEATURE_XMM4_2 (4*32+20) /* Streaming SIMD Extensions-4.2 */
+#define cpu_has_xmm4_2 boot_cpu_has(X86_FEATURE_XMM4_2)
+
+#ifdef CONFIG_X86_64
+#define REX_PRE "0x48, "
+#define SCALE_F 8
+#else
+#define REX_PRE
+#define SCALE_F 4
+#endif
+
+static inline u32 btrfs_crc32c_le_hw_byte(u32 crc, unsigned char const *data,
+ size_t length)
+{
+ while (length--) {
+ __asm__ __volatile__(
+ ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
+ :"=S"(crc)
+ :"0"(crc), "c"(*data)
+ );
+ data++;
+ }
+
+ return crc;
+}
+
+static inline u32 __pure btrfs_crc32c_le_hw(u32 crc, unsigned char const *p,
+ size_t len)
+{
+ unsigned int iquotient = len / SCALE_F;
+ unsigned int iremainder = len % SCALE_F;
+#ifdef CONFIG_X86_64
+ u64 *ptmp = (u64 *)p;
+#else
+ u32 *ptmp = (u32 *)p;
+#endif
+
+ while (iquotient--) {
+ __asm__ __volatile__(
+ ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
+ :"=S"(crc)
+ :"0"(crc), "c"(*ptmp)
+ );
+ ptmp++;
+ }
+
+ if (iremainder)
+ crc = btrfs_crc32c_le_hw_byte(crc, (unsigned char *)ptmp,
+ iremainder);
+
+ return crc;
+}
+#endif /* CONFIG_BTRFS_HW_SUM */
+
+static inline u32 __btrfs_crc32c(u32 crc, unsigned char const *address,
+ size_t len)
+{
+#ifdef CONFIG_BTRFS_HW_SUM
+ if (cpu_has_xmm4_2)
+ return btrfs_crc32c_le_hw(crc, address, len);
+#endif
+ return crc32c_le(crc, address, len);
+}
+
+#else
+
+#define __btrfs_crc32c(seed, data, length) crc32c(seed, data, length)
+
+#endif /* CONFIG_X86 */
+
+/**
+ * implementation of crc32c_le() changed in linux-2.6.23,
+ * has of v0.13 btrfs-progs is using the latest version.
+ * We must workaround older implementations of crc32c_le()
+ * found on older kernel versions.
+ */
+#define btrfs_crc32c(seed, data, length) \
+ __btrfs_crc32c(seed, (unsigned char const *)data, length)
+#endif
+
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
new file mode 100644
index 0000000..71ef0a2
--- /dev/null
+++ b/fs/btrfs/ctree.c
@@ -0,0 +1,3892 @@
+/*
+ * Copyright (C) 2007,2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+#include "locking.h"
+
+static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, int level);
+static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *ins_key,
+ struct btrfs_path *path, int data_size, int extend);
+static int push_node_left(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *dst,
+ struct extent_buffer *src, int empty);
+static int balance_node_right(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *dst_buf,
+ struct extent_buffer *src_buf);
+static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_path *path, int level, int slot);
+
+inline void btrfs_init_path(struct btrfs_path *p)
+{
+ memset(p, 0, sizeof(*p));
+}
+
+struct btrfs_path *btrfs_alloc_path(void)
+{
+ struct btrfs_path *path;
+ path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
+ if (path) {
+ btrfs_init_path(path);
+ path->reada = 1;
+ }
+ return path;
+}
+
+/* this also releases the path */
+void btrfs_free_path(struct btrfs_path *p)
+{
+ btrfs_release_path(NULL, p);
+ kmem_cache_free(btrfs_path_cachep, p);
+}
+
+/*
+ * path release drops references on the extent buffers in the path
+ * and it drops any locks held by this path
+ *
+ * It is safe to call this on paths that no locks or extent buffers held.
+ */
+void noinline btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
+{
+ int i;
+
+ for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+ p->slots[i] = 0;
+ if (!p->nodes[i])
+ continue;
+ if (p->locks[i]) {
+ btrfs_tree_unlock(p->nodes[i]);
+ p->locks[i] = 0;
+ }
+ free_extent_buffer(p->nodes[i]);
+ p->nodes[i] = NULL;
+ }
+}
+
+/*
+ * safely gets a reference on the root node of a tree. A lock
+ * is not taken, so a concurrent writer may put a different node
+ * at the root of the tree. See btrfs_lock_root_node for the
+ * looping required.
+ *
+ * The extent buffer returned by this has a reference taken, so
+ * it won't disappear. It may stop being the root of the tree
+ * at any time because there are no locks held.
+ */
+struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
+{
+ struct extent_buffer *eb;
+ spin_lock(&root->node_lock);
+ eb = root->node;
+ extent_buffer_get(eb);
+ spin_unlock(&root->node_lock);
+ return eb;
+}
+
+/* loop around taking references on and locking the root node of the
+ * tree until you end up with a lock on the root. A locked buffer
+ * is returned, with a reference held.
+ */
+struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
+{
+ struct extent_buffer *eb;
+
+ while(1) {
+ eb = btrfs_root_node(root);
+ btrfs_tree_lock(eb);
+
+ spin_lock(&root->node_lock);
+ if (eb == root->node) {
+ spin_unlock(&root->node_lock);
+ break;
+ }
+ spin_unlock(&root->node_lock);
+
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+ }
+ return eb;
+}
+
+/* cowonly root (everything not a reference counted cow subvolume), just get
+ * put onto a simple dirty list. transaction.c walks this to make sure they
+ * get properly updated on disk.
+ */
+static void add_root_to_dirty_list(struct btrfs_root *root)
+{
+ if (root->track_dirty && list_empty(&root->dirty_list)) {
+ list_add(&root->dirty_list,
+ &root->fs_info->dirty_cowonly_roots);
+ }
+}
+
+/*
+ * used by snapshot creation to make a copy of a root for a tree with
+ * a given objectid. The buffer with the new root node is returned in
+ * cow_ret, and this func returns zero on success or a negative error code.
+ */
+int btrfs_copy_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *buf,
+ struct extent_buffer **cow_ret, u64 new_root_objectid)
+{
+ struct extent_buffer *cow;
+ u32 nritems;
+ int ret = 0;
+ int level;
+ struct btrfs_root *new_root;
+
+ new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
+ if (!new_root)
+ return -ENOMEM;
+
+ memcpy(new_root, root, sizeof(*new_root));
+ new_root->root_key.objectid = new_root_objectid;
+
+ WARN_ON(root->ref_cows && trans->transid !=
+ root->fs_info->running_transaction->transid);
+ WARN_ON(root->ref_cows && trans->transid != root->last_trans);
+
+ level = btrfs_header_level(buf);
+ nritems = btrfs_header_nritems(buf);
+
+ cow = btrfs_alloc_free_block(trans, new_root, buf->len, 0,
+ new_root_objectid, trans->transid,
+ level, buf->start, 0);
+ if (IS_ERR(cow)) {
+ kfree(new_root);
+ return PTR_ERR(cow);
+ }
+
+ copy_extent_buffer(cow, buf, 0, 0, cow->len);
+ btrfs_set_header_bytenr(cow, cow->start);
+ btrfs_set_header_generation(cow, trans->transid);
+ btrfs_set_header_owner(cow, new_root_objectid);
+ btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
+
+ write_extent_buffer(cow, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(cow),
+ BTRFS_FSID_SIZE);
+
+ WARN_ON(btrfs_header_generation(buf) > trans->transid);
+ ret = btrfs_inc_ref(trans, new_root, buf, cow, NULL);
+ kfree(new_root);
+
+ if (ret)
+ return ret;
+
+ btrfs_mark_buffer_dirty(cow);
+ *cow_ret = cow;
+ return 0;
+}
+
+/*
+ * does the dirty work in cow of a single block. The parent block
+ * (if supplied) is updated to point to the new cow copy. The new
+ * buffer is marked dirty and returned locked. If you modify the block
+ * it needs to be marked dirty again.
+ *
+ * search_start -- an allocation hint for the new block
+ *
+ * empty_size -- a hint that you plan on doing more cow. This is the size in bytes
+ * the allocator should try to find free next to the block it returns. This is
+ * just a hint and may be ignored by the allocator.
+ *
+ * prealloc_dest -- if you have already reserved a destination for the cow,
+ * this uses that block instead of allocating a new one. btrfs_alloc_reserved_extent
+ * is used to finish the allocation.
+ */
+int noinline __btrfs_cow_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *buf,
+ struct extent_buffer *parent, int parent_slot,
+ struct extent_buffer **cow_ret,
+ u64 search_start, u64 empty_size,
+ u64 prealloc_dest)
+{
+ u64 parent_start;
+ struct extent_buffer *cow;
+ u32 nritems;
+ int ret = 0;
+ int level;
+ int unlock_orig = 0;
+
+ if (*cow_ret == buf)
+ unlock_orig = 1;
+
+ WARN_ON(!btrfs_tree_locked(buf));
+
+ if (parent)
+ parent_start = parent->start;
+ else
+ parent_start = 0;
+
+ WARN_ON(root->ref_cows && trans->transid !=
+ root->fs_info->running_transaction->transid);
+ WARN_ON(root->ref_cows && trans->transid != root->last_trans);
+
+ level = btrfs_header_level(buf);
+ nritems = btrfs_header_nritems(buf);
+
+ if (prealloc_dest) {
+ struct btrfs_key ins;
+
+ ins.objectid = prealloc_dest;
+ ins.offset = buf->len;
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+
+ ret = btrfs_alloc_reserved_extent(trans, root, parent_start,
+ root->root_key.objectid,
+ trans->transid, level, &ins);
+ BUG_ON(ret);
+ cow = btrfs_init_new_buffer(trans, root, prealloc_dest,
+ buf->len);
+ } else {
+ cow = btrfs_alloc_free_block(trans, root, buf->len,
+ parent_start,
+ root->root_key.objectid,
+ trans->transid, level,
+ search_start, empty_size);
+ }
+ if (IS_ERR(cow))
+ return PTR_ERR(cow);
+
+ copy_extent_buffer(cow, buf, 0, 0, cow->len);
+ btrfs_set_header_bytenr(cow, cow->start);
+ btrfs_set_header_generation(cow, trans->transid);
+ btrfs_set_header_owner(cow, root->root_key.objectid);
+ btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
+
+ write_extent_buffer(cow, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(cow),
+ BTRFS_FSID_SIZE);
+
+ WARN_ON(btrfs_header_generation(buf) > trans->transid);
+ if (btrfs_header_generation(buf) != trans->transid) {
+ u32 nr_extents;
+ ret = btrfs_inc_ref(trans, root, buf, cow, &nr_extents);
+ if (ret)
+ return ret;
+
+ ret = btrfs_cache_ref(trans, root, buf, nr_extents);
+ WARN_ON(ret);
+ } else if (btrfs_header_owner(buf) == BTRFS_TREE_RELOC_OBJECTID) {
+ /*
+ * There are only two places that can drop reference to
+ * tree blocks owned by living reloc trees, one is here,
+ * the other place is btrfs_drop_subtree. In both places,
+ * we check reference count while tree block is locked.
+ * Furthermore, if reference count is one, it won't get
+ * increased by someone else.
+ */
+ u32 refs;
+ ret = btrfs_lookup_extent_ref(trans, root, buf->start,
+ buf->len, &refs);
+ BUG_ON(ret);
+ if (refs == 1) {
+ ret = btrfs_update_ref(trans, root, buf, cow,
+ 0, nritems);
+ clean_tree_block(trans, root, buf);
+ } else {
+ ret = btrfs_inc_ref(trans, root, buf, cow, NULL);
+ }
+ BUG_ON(ret);
+ } else {
+ ret = btrfs_update_ref(trans, root, buf, cow, 0, nritems);
+ if (ret)
+ return ret;
+ clean_tree_block(trans, root, buf);
+ }
+
+ if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
+ ret = btrfs_reloc_tree_cache_ref(trans, root, cow, buf->start);
+ WARN_ON(ret);
+ }
+
+ if (buf == root->node) {
+ WARN_ON(parent && parent != buf);
+
+ spin_lock(&root->node_lock);
+ root->node = cow;
+ extent_buffer_get(cow);
+ spin_unlock(&root->node_lock);
+
+ if (buf != root->commit_root) {
+ btrfs_free_extent(trans, root, buf->start,
+ buf->len, buf->start,
+ root->root_key.objectid,
+ btrfs_header_generation(buf),
+ level, 1);
+ }
+ free_extent_buffer(buf);
+ add_root_to_dirty_list(root);
+ } else {
+ btrfs_set_node_blockptr(parent, parent_slot,
+ cow->start);
+ WARN_ON(trans->transid == 0);
+ btrfs_set_node_ptr_generation(parent, parent_slot,
+ trans->transid);
+ btrfs_mark_buffer_dirty(parent);
+ WARN_ON(btrfs_header_generation(parent) != trans->transid);
+ btrfs_free_extent(trans, root, buf->start, buf->len,
+ parent_start, btrfs_header_owner(parent),
+ btrfs_header_generation(parent), level, 1);
+ }
+ if (unlock_orig)
+ btrfs_tree_unlock(buf);
+ free_extent_buffer(buf);
+ btrfs_mark_buffer_dirty(cow);
+ *cow_ret = cow;
+ return 0;
+}
+
+/*
+ * cows a single block, see __btrfs_cow_block for the real work.
+ * This version of it has extra checks so that a block isn't cow'd more than
+ * once per transaction, as long as it hasn't been written yet
+ */
+int noinline btrfs_cow_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *buf,
+ struct extent_buffer *parent, int parent_slot,
+ struct extent_buffer **cow_ret, u64 prealloc_dest)
+{
+ u64 search_start;
+ int ret;
+
+ if (trans->transaction != root->fs_info->running_transaction) {
+ printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+ root->fs_info->running_transaction->transid);
+ WARN_ON(1);
+ }
+ if (trans->transid != root->fs_info->generation) {
+ printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+ root->fs_info->generation);
+ WARN_ON(1);
+ }
+
+ spin_lock(&root->fs_info->hash_lock);
+ if (btrfs_header_generation(buf) == trans->transid &&
+ btrfs_header_owner(buf) == root->root_key.objectid &&
+ !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
+ *cow_ret = buf;
+ spin_unlock(&root->fs_info->hash_lock);
+ WARN_ON(prealloc_dest);
+ return 0;
+ }
+ spin_unlock(&root->fs_info->hash_lock);
+ search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
+ ret = __btrfs_cow_block(trans, root, buf, parent,
+ parent_slot, cow_ret, search_start, 0,
+ prealloc_dest);
+ return ret;
+}
+
+/*
+ * helper function for defrag to decide if two blocks pointed to by a
+ * node are actually close by
+ */
+static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
+{
+ if (blocknr < other && other - (blocknr + blocksize) < 32768)
+ return 1;
+ if (blocknr > other && blocknr - (other + blocksize) < 32768)
+ return 1;
+ return 0;
+}
+
+/*
+ * compare two keys in a memcmp fashion
+ */
+static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
+{
+ struct btrfs_key k1;
+
+ btrfs_disk_key_to_cpu(&k1, disk);
+
+ if (k1.objectid > k2->objectid)
+ return 1;
+ if (k1.objectid < k2->objectid)
+ return -1;
+ if (k1.type > k2->type)
+ return 1;
+ if (k1.type < k2->type)
+ return -1;
+ if (k1.offset > k2->offset)
+ return 1;
+ if (k1.offset < k2->offset)
+ return -1;
+ return 0;
+}
+
+/*
+ * same as comp_keys only with two btrfs_key's
+ */
+static int comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
+{
+ if (k1->objectid > k2->objectid)
+ return 1;
+ if (k1->objectid < k2->objectid)
+ return -1;
+ if (k1->type > k2->type)
+ return 1;
+ if (k1->type < k2->type)
+ return -1;
+ if (k1->offset > k2->offset)
+ return 1;
+ if (k1->offset < k2->offset)
+ return -1;
+ return 0;
+}
+
+/*
+ * this is used by the defrag code to go through all the
+ * leaves pointed to by a node and reallocate them so that
+ * disk order is close to key order
+ */
+int btrfs_realloc_node(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *parent,
+ int start_slot, int cache_only, u64 *last_ret,
+ struct btrfs_key *progress)
+{
+ struct extent_buffer *cur;
+ u64 blocknr;
+ u64 gen;
+ u64 search_start = *last_ret;
+ u64 last_block = 0;
+ u64 other;
+ u32 parent_nritems;
+ int end_slot;
+ int i;
+ int err = 0;
+ int parent_level;
+ int uptodate;
+ u32 blocksize;
+ int progress_passed = 0;
+ struct btrfs_disk_key disk_key;
+
+ parent_level = btrfs_header_level(parent);
+ if (cache_only && parent_level != 1)
+ return 0;
+
+ if (trans->transaction != root->fs_info->running_transaction) {
+ printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+ root->fs_info->running_transaction->transid);
+ WARN_ON(1);
+ }
+ if (trans->transid != root->fs_info->generation) {
+ printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+ root->fs_info->generation);
+ WARN_ON(1);
+ }
+
+ parent_nritems = btrfs_header_nritems(parent);
+ blocksize = btrfs_level_size(root, parent_level - 1);
+ end_slot = parent_nritems;
+
+ if (parent_nritems == 1)
+ return 0;
+
+ for (i = start_slot; i < end_slot; i++) {
+ int close = 1;
+
+ if (!parent->map_token) {
+ map_extent_buffer(parent,
+ btrfs_node_key_ptr_offset(i),
+ sizeof(struct btrfs_key_ptr),
+ &parent->map_token, &parent->kaddr,
+ &parent->map_start, &parent->map_len,
+ KM_USER1);
+ }
+ btrfs_node_key(parent, &disk_key, i);
+ if (!progress_passed && comp_keys(&disk_key, progress) < 0)
+ continue;
+
+ progress_passed = 1;
+ blocknr = btrfs_node_blockptr(parent, i);
+ gen = btrfs_node_ptr_generation(parent, i);
+ if (last_block == 0)
+ last_block = blocknr;
+
+ if (i > 0) {
+ other = btrfs_node_blockptr(parent, i - 1);
+ close = close_blocks(blocknr, other, blocksize);
+ }
+ if (!close && i < end_slot - 2) {
+ other = btrfs_node_blockptr(parent, i + 1);
+ close = close_blocks(blocknr, other, blocksize);
+ }
+ if (close) {
+ last_block = blocknr;
+ continue;
+ }
+ if (parent->map_token) {
+ unmap_extent_buffer(parent, parent->map_token,
+ KM_USER1);
+ parent->map_token = NULL;
+ }
+
+ cur = btrfs_find_tree_block(root, blocknr, blocksize);
+ if (cur)
+ uptodate = btrfs_buffer_uptodate(cur, gen);
+ else
+ uptodate = 0;
+ if (!cur || !uptodate) {
+ if (cache_only) {
+ free_extent_buffer(cur);
+ continue;
+ }
+ if (!cur) {
+ cur = read_tree_block(root, blocknr,
+ blocksize, gen);
+ } else if (!uptodate) {
+ btrfs_read_buffer(cur, gen);
+ }
+ }
+ if (search_start == 0)
+ search_start = last_block;
+
+ btrfs_tree_lock(cur);
+ err = __btrfs_cow_block(trans, root, cur, parent, i,
+ &cur, search_start,
+ min(16 * blocksize,
+ (end_slot - i) * blocksize), 0);
+ if (err) {
+ btrfs_tree_unlock(cur);
+ free_extent_buffer(cur);
+ break;
+ }
+ search_start = cur->start;
+ last_block = cur->start;
+ *last_ret = search_start;
+ btrfs_tree_unlock(cur);
+ free_extent_buffer(cur);
+ }
+ if (parent->map_token) {
+ unmap_extent_buffer(parent, parent->map_token,
+ KM_USER1);
+ parent->map_token = NULL;
+ }
+ return err;
+}
+
+/*
+ * The leaf data grows from end-to-front in the node.
+ * this returns the address of the start of the last item,
+ * which is the stop of the leaf data stack
+ */
+static inline unsigned int leaf_data_end(struct btrfs_root *root,
+ struct extent_buffer *leaf)
+{
+ u32 nr = btrfs_header_nritems(leaf);
+ if (nr == 0)
+ return BTRFS_LEAF_DATA_SIZE(root);
+ return btrfs_item_offset_nr(leaf, nr - 1);
+}
+
+/*
+ * extra debugging checks to make sure all the items in a key are
+ * well formed and in the proper order
+ */
+static int check_node(struct btrfs_root *root, struct btrfs_path *path,
+ int level)
+{
+ struct extent_buffer *parent = NULL;
+ struct extent_buffer *node = path->nodes[level];
+ struct btrfs_disk_key parent_key;
+ struct btrfs_disk_key node_key;
+ int parent_slot;
+ int slot;
+ struct btrfs_key cpukey;
+ u32 nritems = btrfs_header_nritems(node);
+
+ if (path->nodes[level + 1])
+ parent = path->nodes[level + 1];
+
+ slot = path->slots[level];
+ BUG_ON(nritems == 0);
+ if (parent) {
+ parent_slot = path->slots[level + 1];
+ btrfs_node_key(parent, &parent_key, parent_slot);
+ btrfs_node_key(node, &node_key, 0);
+ BUG_ON(memcmp(&parent_key, &node_key,
+ sizeof(struct btrfs_disk_key)));
+ BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
+ btrfs_header_bytenr(node));
+ }
+ BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
+ if (slot != 0) {
+ btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
+ btrfs_node_key(node, &node_key, slot);
+ BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
+ }
+ if (slot < nritems - 1) {
+ btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
+ btrfs_node_key(node, &node_key, slot);
+ BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
+ }
+ return 0;
+}
+
+/*
+ * extra checking to make sure all the items in a leaf are
+ * well formed and in the proper order
+ */
+static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
+ int level)
+{
+ struct extent_buffer *leaf = path->nodes[level];
+ struct extent_buffer *parent = NULL;
+ int parent_slot;
+ struct btrfs_key cpukey;
+ struct btrfs_disk_key parent_key;
+ struct btrfs_disk_key leaf_key;
+ int slot = path->slots[0];
+
+ u32 nritems = btrfs_header_nritems(leaf);
+
+ if (path->nodes[level + 1])
+ parent = path->nodes[level + 1];
+
+ if (nritems == 0)
+ return 0;
+
+ if (parent) {
+ parent_slot = path->slots[level + 1];
+ btrfs_node_key(parent, &parent_key, parent_slot);
+ btrfs_item_key(leaf, &leaf_key, 0);
+
+ BUG_ON(memcmp(&parent_key, &leaf_key,
+ sizeof(struct btrfs_disk_key)));
+ BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
+ btrfs_header_bytenr(leaf));
+ }
+#if 0
+ for (i = 0; nritems > 1 && i < nritems - 2; i++) {
+ btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
+ btrfs_item_key(leaf, &leaf_key, i);
+ if (comp_keys(&leaf_key, &cpukey) >= 0) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d offset bad key\n", i);
+ BUG_ON(1);
+ }
+ if (btrfs_item_offset_nr(leaf, i) !=
+ btrfs_item_end_nr(leaf, i + 1)) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d offset bad\n", i);
+ BUG_ON(1);
+ }
+ if (i == 0) {
+ if (btrfs_item_offset_nr(leaf, i) +
+ btrfs_item_size_nr(leaf, i) !=
+ BTRFS_LEAF_DATA_SIZE(root)) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d first offset bad\n", i);
+ BUG_ON(1);
+ }
+ }
+ }
+ if (nritems > 0) {
+ if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d bad size \n", nritems - 1);
+ BUG_ON(1);
+ }
+ }
+#endif
+ if (slot != 0 && slot < nritems - 1) {
+ btrfs_item_key(leaf, &leaf_key, slot);
+ btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
+ if (comp_keys(&leaf_key, &cpukey) <= 0) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d offset bad key\n", slot);
+ BUG_ON(1);
+ }
+ if (btrfs_item_offset_nr(leaf, slot - 1) !=
+ btrfs_item_end_nr(leaf, slot)) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d offset bad\n", slot);
+ BUG_ON(1);
+ }
+ }
+ if (slot < nritems - 1) {
+ btrfs_item_key(leaf, &leaf_key, slot);
+ btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
+ BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
+ if (btrfs_item_offset_nr(leaf, slot) !=
+ btrfs_item_end_nr(leaf, slot + 1)) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d offset bad\n", slot);
+ BUG_ON(1);
+ }
+ }
+ BUG_ON(btrfs_item_offset_nr(leaf, 0) +
+ btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
+ return 0;
+}
+
+static int noinline check_block(struct btrfs_root *root,
+ struct btrfs_path *path, int level)
+{
+ u64 found_start;
+ return 0;
+ if (btrfs_header_level(path->nodes[level]) != level)
+ printk("warning: bad level %Lu wanted %d found %d\n",
+ path->nodes[level]->start, level,
+ btrfs_header_level(path->nodes[level]));
+ found_start = btrfs_header_bytenr(path->nodes[level]);
+ if (found_start != path->nodes[level]->start) {
+ printk("warning: bad bytentr %Lu found %Lu\n",
+ path->nodes[level]->start, found_start);
+ }
+#if 0
+ struct extent_buffer *buf = path->nodes[level];
+
+ if (memcmp_extent_buffer(buf, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(buf),
+ BTRFS_FSID_SIZE)) {
+ printk("warning bad block %Lu\n", buf->start);
+ return 1;
+ }
+#endif
+ if (level == 0)
+ return check_leaf(root, path, level);
+ return check_node(root, path, level);
+}
+
+/*
+ * search for key in the extent_buffer. The items start at offset p,
+ * and they are item_size apart. There are 'max' items in p.
+ *
+ * the slot in the array is returned via slot, and it points to
+ * the place where you would insert key if it is not found in
+ * the array.
+ *
+ * slot may point to max if the key is bigger than all of the keys
+ */
+static noinline int generic_bin_search(struct extent_buffer *eb,
+ unsigned long p,
+ int item_size, struct btrfs_key *key,
+ int max, int *slot)
+{
+ int low = 0;
+ int high = max;
+ int mid;
+ int ret;
+ struct btrfs_disk_key *tmp = NULL;
+ struct btrfs_disk_key unaligned;
+ unsigned long offset;
+ char *map_token = NULL;
+ char *kaddr = NULL;
+ unsigned long map_start = 0;
+ unsigned long map_len = 0;
+ int err;
+
+ while(low < high) {
+ mid = (low + high) / 2;
+ offset = p + mid * item_size;
+
+ if (!map_token || offset < map_start ||
+ (offset + sizeof(struct btrfs_disk_key)) >
+ map_start + map_len) {
+ if (map_token) {
+ unmap_extent_buffer(eb, map_token, KM_USER0);
+ map_token = NULL;
+ }
+ err = map_extent_buffer(eb, offset,
+ sizeof(struct btrfs_disk_key),
+ &map_token, &kaddr,
+ &map_start, &map_len, KM_USER0);
+
+ if (!err) {
+ tmp = (struct btrfs_disk_key *)(kaddr + offset -
+ map_start);
+ } else {
+ read_extent_buffer(eb, &unaligned,
+ offset, sizeof(unaligned));
+ tmp = &unaligned;
+ }
+
+ } else {
+ tmp = (struct btrfs_disk_key *)(kaddr + offset -
+ map_start);
+ }
+ ret = comp_keys(tmp, key);
+
+ if (ret < 0)
+ low = mid + 1;
+ else if (ret > 0)
+ high = mid;
+ else {
+ *slot = mid;
+ if (map_token)
+ unmap_extent_buffer(eb, map_token, KM_USER0);
+ return 0;
+ }
+ }
+ *slot = low;
+ if (map_token)
+ unmap_extent_buffer(eb, map_token, KM_USER0);
+ return 1;
+}
+
+/*
+ * simple bin_search frontend that does the right thing for
+ * leaves vs nodes
+ */
+static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
+ int level, int *slot)
+{
+ if (level == 0) {
+ return generic_bin_search(eb,
+ offsetof(struct btrfs_leaf, items),
+ sizeof(struct btrfs_item),
+ key, btrfs_header_nritems(eb),
+ slot);
+ } else {
+ return generic_bin_search(eb,
+ offsetof(struct btrfs_node, ptrs),
+ sizeof(struct btrfs_key_ptr),
+ key, btrfs_header_nritems(eb),
+ slot);
+ }
+ return -1;
+}
+
+/* given a node and slot number, this reads the blocks it points to. The
+ * extent buffer is returned with a reference taken (but unlocked).
+ * NULL is returned on error.
+ */
+static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
+ struct extent_buffer *parent, int slot)
+{
+ int level = btrfs_header_level(parent);
+ if (slot < 0)
+ return NULL;
+ if (slot >= btrfs_header_nritems(parent))
+ return NULL;
+
+ BUG_ON(level == 0);
+
+ return read_tree_block(root, btrfs_node_blockptr(parent, slot),
+ btrfs_level_size(root, level - 1),
+ btrfs_node_ptr_generation(parent, slot));
+}
+
+/*
+ * node level balancing, used to make sure nodes are in proper order for
+ * item deletion. We balance from the top down, so we have to make sure
+ * that a deletion won't leave an node completely empty later on.
+ */
+static noinline int balance_level(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int level)
+{
+ struct extent_buffer *right = NULL;
+ struct extent_buffer *mid;
+ struct extent_buffer *left = NULL;
+ struct extent_buffer *parent = NULL;
+ int ret = 0;
+ int wret;
+ int pslot;
+ int orig_slot = path->slots[level];
+ int err_on_enospc = 0;
+ u64 orig_ptr;
+
+ if (level == 0)
+ return 0;
+
+ mid = path->nodes[level];
+ WARN_ON(!path->locks[level]);
+ WARN_ON(btrfs_header_generation(mid) != trans->transid);
+
+ orig_ptr = btrfs_node_blockptr(mid, orig_slot);
+
+ if (level < BTRFS_MAX_LEVEL - 1)
+ parent = path->nodes[level + 1];
+ pslot = path->slots[level + 1];
+
+ /*
+ * deal with the case where there is only one pointer in the root
+ * by promoting the node below to a root
+ */
+ if (!parent) {
+ struct extent_buffer *child;
+
+ if (btrfs_header_nritems(mid) != 1)
+ return 0;
+
+ /* promote the child to a root */
+ child = read_node_slot(root, mid, 0);
+ btrfs_tree_lock(child);
+ BUG_ON(!child);
+ ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
+ BUG_ON(ret);
+
+ spin_lock(&root->node_lock);
+ root->node = child;
+ spin_unlock(&root->node_lock);
+
+ ret = btrfs_update_extent_ref(trans, root, child->start,
+ mid->start, child->start,
+ root->root_key.objectid,
+ trans->transid, level - 1);
+ BUG_ON(ret);
+
+ add_root_to_dirty_list(root);
+ btrfs_tree_unlock(child);
+ path->locks[level] = 0;
+ path->nodes[level] = NULL;
+ clean_tree_block(trans, root, mid);
+ btrfs_tree_unlock(mid);
+ /* once for the path */
+ free_extent_buffer(mid);
+ ret = btrfs_free_extent(trans, root, mid->start, mid->len,
+ mid->start, root->root_key.objectid,
+ btrfs_header_generation(mid),
+ level, 1);
+ /* once for the root ptr */
+ free_extent_buffer(mid);
+ return ret;
+ }
+ if (btrfs_header_nritems(mid) >
+ BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
+ return 0;
+
+ if (btrfs_header_nritems(mid) < 2)
+ err_on_enospc = 1;
+
+ left = read_node_slot(root, parent, pslot - 1);
+ if (left) {
+ btrfs_tree_lock(left);
+ wret = btrfs_cow_block(trans, root, left,
+ parent, pslot - 1, &left, 0);
+ if (wret) {
+ ret = wret;
+ goto enospc;
+ }
+ }
+ right = read_node_slot(root, parent, pslot + 1);
+ if (right) {
+ btrfs_tree_lock(right);
+ wret = btrfs_cow_block(trans, root, right,
+ parent, pslot + 1, &right, 0);
+ if (wret) {
+ ret = wret;
+ goto enospc;
+ }
+ }
+
+ /* first, try to make some room in the middle buffer */
+ if (left) {
+ orig_slot += btrfs_header_nritems(left);
+ wret = push_node_left(trans, root, left, mid, 1);
+ if (wret < 0)
+ ret = wret;
+ if (btrfs_header_nritems(mid) < 2)
+ err_on_enospc = 1;
+ }
+
+ /*
+ * then try to empty the right most buffer into the middle
+ */
+ if (right) {
+ wret = push_node_left(trans, root, mid, right, 1);
+ if (wret < 0 && wret != -ENOSPC)
+ ret = wret;
+ if (btrfs_header_nritems(right) == 0) {
+ u64 bytenr = right->start;
+ u64 generation = btrfs_header_generation(parent);
+ u32 blocksize = right->len;
+
+ clean_tree_block(trans, root, right);
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ right = NULL;
+ wret = del_ptr(trans, root, path, level + 1, pslot +
+ 1);
+ if (wret)
+ ret = wret;
+ wret = btrfs_free_extent(trans, root, bytenr,
+ blocksize, parent->start,
+ btrfs_header_owner(parent),
+ generation, level, 1);
+ if (wret)
+ ret = wret;
+ } else {
+ struct btrfs_disk_key right_key;
+ btrfs_node_key(right, &right_key, 0);
+ btrfs_set_node_key(parent, &right_key, pslot + 1);
+ btrfs_mark_buffer_dirty(parent);
+ }
+ }
+ if (btrfs_header_nritems(mid) == 1) {
+ /*
+ * we're not allowed to leave a node with one item in the
+ * tree during a delete. A deletion from lower in the tree
+ * could try to delete the only pointer in this node.
+ * So, pull some keys from the left.
+ * There has to be a left pointer at this point because
+ * otherwise we would have pulled some pointers from the
+ * right
+ */
+ BUG_ON(!left);
+ wret = balance_node_right(trans, root, mid, left);
+ if (wret < 0) {
+ ret = wret;
+ goto enospc;
+ }
+ if (wret == 1) {
+ wret = push_node_left(trans, root, left, mid, 1);
+ if (wret < 0)
+ ret = wret;
+ }
+ BUG_ON(wret == 1);
+ }
+ if (btrfs_header_nritems(mid) == 0) {
+ /* we've managed to empty the middle node, drop it */
+ u64 root_gen = btrfs_header_generation(parent);
+ u64 bytenr = mid->start;
+ u32 blocksize = mid->len;
+
+ clean_tree_block(trans, root, mid);
+ btrfs_tree_unlock(mid);
+ free_extent_buffer(mid);
+ mid = NULL;
+ wret = del_ptr(trans, root, path, level + 1, pslot);
+ if (wret)
+ ret = wret;
+ wret = btrfs_free_extent(trans, root, bytenr, blocksize,
+ parent->start,
+ btrfs_header_owner(parent),
+ root_gen, level, 1);
+ if (wret)
+ ret = wret;
+ } else {
+ /* update the parent key to reflect our changes */
+ struct btrfs_disk_key mid_key;
+ btrfs_node_key(mid, &mid_key, 0);
+ btrfs_set_node_key(parent, &mid_key, pslot);
+ btrfs_mark_buffer_dirty(parent);
+ }
+
+ /* update the path */
+ if (left) {
+ if (btrfs_header_nritems(left) > orig_slot) {
+ extent_buffer_get(left);
+ /* left was locked after cow */
+ path->nodes[level] = left;
+ path->slots[level + 1] -= 1;
+ path->slots[level] = orig_slot;
+ if (mid) {
+ btrfs_tree_unlock(mid);
+ free_extent_buffer(mid);
+ }
+ } else {
+ orig_slot -= btrfs_header_nritems(left);
+ path->slots[level] = orig_slot;
+ }
+ }
+ /* double check we haven't messed things up */
+ check_block(root, path, level);
+ if (orig_ptr !=
+ btrfs_node_blockptr(path->nodes[level], path->slots[level]))
+ BUG();
+enospc:
+ if (right) {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ }
+ if (left) {
+ if (path->nodes[level] != left)
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ }
+ return ret;
+}
+
+/* Node balancing for insertion. Here we only split or push nodes around
+ * when they are completely full. This is also done top down, so we
+ * have to be pessimistic.
+ */
+static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int level)
+{
+ struct extent_buffer *right = NULL;
+ struct extent_buffer *mid;
+ struct extent_buffer *left = NULL;
+ struct extent_buffer *parent = NULL;
+ int ret = 0;
+ int wret;
+ int pslot;
+ int orig_slot = path->slots[level];
+ u64 orig_ptr;
+
+ if (level == 0)
+ return 1;
+
+ mid = path->nodes[level];
+ WARN_ON(btrfs_header_generation(mid) != trans->transid);
+ orig_ptr = btrfs_node_blockptr(mid, orig_slot);
+
+ if (level < BTRFS_MAX_LEVEL - 1)
+ parent = path->nodes[level + 1];
+ pslot = path->slots[level + 1];
+
+ if (!parent)
+ return 1;
+
+ left = read_node_slot(root, parent, pslot - 1);
+
+ /* first, try to make some room in the middle buffer */
+ if (left) {
+ u32 left_nr;
+
+ btrfs_tree_lock(left);
+ left_nr = btrfs_header_nritems(left);
+ if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
+ wret = 1;
+ } else {
+ ret = btrfs_cow_block(trans, root, left, parent,
+ pslot - 1, &left, 0);
+ if (ret)
+ wret = 1;
+ else {
+ wret = push_node_left(trans, root,
+ left, mid, 0);
+ }
+ }
+ if (wret < 0)
+ ret = wret;
+ if (wret == 0) {
+ struct btrfs_disk_key disk_key;
+ orig_slot += left_nr;
+ btrfs_node_key(mid, &disk_key, 0);
+ btrfs_set_node_key(parent, &disk_key, pslot);
+ btrfs_mark_buffer_dirty(parent);
+ if (btrfs_header_nritems(left) > orig_slot) {
+ path->nodes[level] = left;
+ path->slots[level + 1] -= 1;
+ path->slots[level] = orig_slot;
+ btrfs_tree_unlock(mid);
+ free_extent_buffer(mid);
+ } else {
+ orig_slot -=
+ btrfs_header_nritems(left);
+ path->slots[level] = orig_slot;
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ }
+ return 0;
+ }
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ }
+ right = read_node_slot(root, parent, pslot + 1);
+
+ /*
+ * then try to empty the right most buffer into the middle
+ */
+ if (right) {
+ u32 right_nr;
+ btrfs_tree_lock(right);
+ right_nr = btrfs_header_nritems(right);
+ if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
+ wret = 1;
+ } else {
+ ret = btrfs_cow_block(trans, root, right,
+ parent, pslot + 1,
+ &right, 0);
+ if (ret)
+ wret = 1;
+ else {
+ wret = balance_node_right(trans, root,
+ right, mid);
+ }
+ }
+ if (wret < 0)
+ ret = wret;
+ if (wret == 0) {
+ struct btrfs_disk_key disk_key;
+
+ btrfs_node_key(right, &disk_key, 0);
+ btrfs_set_node_key(parent, &disk_key, pslot + 1);
+ btrfs_mark_buffer_dirty(parent);
+
+ if (btrfs_header_nritems(mid) <= orig_slot) {
+ path->nodes[level] = right;
+ path->slots[level + 1] += 1;
+ path->slots[level] = orig_slot -
+ btrfs_header_nritems(mid);
+ btrfs_tree_unlock(mid);
+ free_extent_buffer(mid);
+ } else {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ }
+ return 0;
+ }
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ }
+ return 1;
+}
+
+/*
+ * readahead one full node of leaves, finding things that are close
+ * to the block in 'slot', and triggering ra on them.
+ */
+static noinline void reada_for_search(struct btrfs_root *root,
+ struct btrfs_path *path,
+ int level, int slot, u64 objectid)
+{
+ struct extent_buffer *node;
+ struct btrfs_disk_key disk_key;
+ u32 nritems;
+ u64 search;
+ u64 lowest_read;
+ u64 highest_read;
+ u64 nread = 0;
+ int direction = path->reada;
+ struct extent_buffer *eb;
+ u32 nr;
+ u32 blocksize;
+ u32 nscan = 0;
+
+ if (level != 1)
+ return;
+
+ if (!path->nodes[level])
+ return;
+
+ node = path->nodes[level];
+
+ search = btrfs_node_blockptr(node, slot);
+ blocksize = btrfs_level_size(root, level - 1);
+ eb = btrfs_find_tree_block(root, search, blocksize);
+ if (eb) {
+ free_extent_buffer(eb);
+ return;
+ }
+
+ highest_read = search;
+ lowest_read = search;
+
+ nritems = btrfs_header_nritems(node);
+ nr = slot;
+ while(1) {
+ if (direction < 0) {
+ if (nr == 0)
+ break;
+ nr--;
+ } else if (direction > 0) {
+ nr++;
+ if (nr >= nritems)
+ break;
+ }
+ if (path->reada < 0 && objectid) {
+ btrfs_node_key(node, &disk_key, nr);
+ if (btrfs_disk_key_objectid(&disk_key) != objectid)
+ break;
+ }
+ search = btrfs_node_blockptr(node, nr);
+ if ((search >= lowest_read && search <= highest_read) ||
+ (search < lowest_read && lowest_read - search <= 16384) ||
+ (search > highest_read && search - highest_read <= 16384)) {
+ readahead_tree_block(root, search, blocksize,
+ btrfs_node_ptr_generation(node, nr));
+ nread += blocksize;
+ }
+ nscan++;
+ if (path->reada < 2 && (nread > (64 * 1024) || nscan > 32))
+ break;
+ if(nread > (256 * 1024) || nscan > 128)
+ break;
+
+ if (search < lowest_read)
+ lowest_read = search;
+ if (search > highest_read)
+ highest_read = search;
+ }
+}
+
+/*
+ * when we walk down the tree, it is usually safe to unlock the higher layers in
+ * the tree. The exceptions are when our path goes through slot 0, because operations
+ * on the tree might require changing key pointers higher up in the tree.
+ *
+ * callers might also have set path->keep_locks, which tells this code to
+ * keep the lock if the path points to the last slot in the block. This is
+ * part of walking through the tree, and selecting the next slot in the higher
+ * block.
+ *
+ * lowest_unlock sets the lowest level in the tree we're allowed to unlock.
+ * so if lowest_unlock is 1, level 0 won't be unlocked
+ */
+static noinline void unlock_up(struct btrfs_path *path, int level,
+ int lowest_unlock)
+{
+ int i;
+ int skip_level = level;
+ int no_skips = 0;
+ struct extent_buffer *t;
+
+ for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+ if (!path->nodes[i])
+ break;
+ if (!path->locks[i])
+ break;
+ if (!no_skips && path->slots[i] == 0) {
+ skip_level = i + 1;
+ continue;
+ }
+ if (!no_skips && path->keep_locks) {
+ u32 nritems;
+ t = path->nodes[i];
+ nritems = btrfs_header_nritems(t);
+ if (nritems < 1 || path->slots[i] >= nritems - 1) {
+ skip_level = i + 1;
+ continue;
+ }
+ }
+ if (skip_level < i && i >= lowest_unlock)
+ no_skips = 1;
+
+ t = path->nodes[i];
+ if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
+ btrfs_tree_unlock(t);
+ path->locks[i] = 0;
+ }
+ }
+}
+
+/*
+ * look for key in the tree. path is filled in with nodes along the way
+ * if key is found, we return zero and you can find the item in the leaf
+ * level of the path (level 0)
+ *
+ * If the key isn't found, the path points to the slot where it should
+ * be inserted, and 1 is returned. If there are other errors during the
+ * search a negative error number is returned.
+ *
+ * if ins_len > 0, nodes and leaves will be split as we walk down the
+ * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
+ * possible)
+ */
+int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *key, struct btrfs_path *p, int
+ ins_len, int cow)
+{
+ struct extent_buffer *b;
+ struct extent_buffer *tmp;
+ int slot;
+ int ret;
+ int level;
+ int should_reada = p->reada;
+ int lowest_unlock = 1;
+ int blocksize;
+ u8 lowest_level = 0;
+ u64 blocknr;
+ u64 gen;
+ struct btrfs_key prealloc_block;
+
+ lowest_level = p->lowest_level;
+ WARN_ON(lowest_level && ins_len > 0);
+ WARN_ON(p->nodes[0] != NULL);
+
+ if (ins_len < 0)
+ lowest_unlock = 2;
+
+ prealloc_block.objectid = 0;
+
+again:
+ if (p->skip_locking)
+ b = btrfs_root_node(root);
+ else
+ b = btrfs_lock_root_node(root);
+
+ while (b) {
+ level = btrfs_header_level(b);
+
+ /*
+ * setup the path here so we can release it under lock
+ * contention with the cow code
+ */
+ p->nodes[level] = b;
+ if (!p->skip_locking)
+ p->locks[level] = 1;
+
+ if (cow) {
+ int wret;
+
+ /* is a cow on this block not required */
+ spin_lock(&root->fs_info->hash_lock);
+ if (btrfs_header_generation(b) == trans->transid &&
+ btrfs_header_owner(b) == root->root_key.objectid &&
+ !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
+ spin_unlock(&root->fs_info->hash_lock);
+ goto cow_done;
+ }
+ spin_unlock(&root->fs_info->hash_lock);
+
+ /* ok, we have to cow, is our old prealloc the right
+ * size?
+ */
+ if (prealloc_block.objectid &&
+ prealloc_block.offset != b->len) {
+ btrfs_free_reserved_extent(root,
+ prealloc_block.objectid,
+ prealloc_block.offset);
+ prealloc_block.objectid = 0;
+ }
+
+ /*
+ * for higher level blocks, try not to allocate blocks
+ * with the block and the parent locks held.
+ */
+ if (level > 1 && !prealloc_block.objectid &&
+ btrfs_path_lock_waiting(p, level)) {
+ u32 size = b->len;
+ u64 hint = b->start;
+
+ btrfs_release_path(root, p);
+ ret = btrfs_reserve_extent(trans, root,
+ size, size, 0,
+ hint, (u64)-1,
+ &prealloc_block, 0);
+ BUG_ON(ret);
+ goto again;
+ }
+
+ wret = btrfs_cow_block(trans, root, b,
+ p->nodes[level + 1],
+ p->slots[level + 1],
+ &b, prealloc_block.objectid);
+ prealloc_block.objectid = 0;
+ if (wret) {
+ free_extent_buffer(b);
+ ret = wret;
+ goto done;
+ }
+ }
+cow_done:
+ BUG_ON(!cow && ins_len);
+ if (level != btrfs_header_level(b))
+ WARN_ON(1);
+ level = btrfs_header_level(b);
+
+ p->nodes[level] = b;
+ if (!p->skip_locking)
+ p->locks[level] = 1;
+
+ ret = check_block(root, p, level);
+ if (ret) {
+ ret = -1;
+ goto done;
+ }
+
+ ret = bin_search(b, key, level, &slot);
+ if (level != 0) {
+ if (ret && slot > 0)
+ slot -= 1;
+ p->slots[level] = slot;
+ if (ins_len > 0 && btrfs_header_nritems(b) >=
+ BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
+ int sret = split_node(trans, root, p, level);
+ BUG_ON(sret > 0);
+ if (sret) {
+ ret = sret;
+ goto done;
+ }
+ b = p->nodes[level];
+ slot = p->slots[level];
+ } else if (ins_len < 0) {
+ int sret = balance_level(trans, root, p,
+ level);
+ if (sret) {
+ ret = sret;
+ goto done;
+ }
+ b = p->nodes[level];
+ if (!b) {
+ btrfs_release_path(NULL, p);
+ goto again;
+ }
+ slot = p->slots[level];
+ BUG_ON(btrfs_header_nritems(b) == 1);
+ }
+ unlock_up(p, level, lowest_unlock);
+
+ /* this is only true while dropping a snapshot */
+ if (level == lowest_level) {
+ ret = 0;
+ goto done;
+ }
+
+ blocknr = btrfs_node_blockptr(b, slot);
+ gen = btrfs_node_ptr_generation(b, slot);
+ blocksize = btrfs_level_size(root, level - 1);
+
+ tmp = btrfs_find_tree_block(root, blocknr, blocksize);
+ if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
+ b = tmp;
+ } else {
+ /*
+ * reduce lock contention at high levels
+ * of the btree by dropping locks before
+ * we read.
+ */
+ if (level > 1) {
+ btrfs_release_path(NULL, p);
+ if (tmp)
+ free_extent_buffer(tmp);
+ if (should_reada)
+ reada_for_search(root, p,
+ level, slot,
+ key->objectid);
+
+ tmp = read_tree_block(root, blocknr,
+ blocksize, gen);
+ if (tmp)
+ free_extent_buffer(tmp);
+ goto again;
+ } else {
+ if (tmp)
+ free_extent_buffer(tmp);
+ if (should_reada)
+ reada_for_search(root, p,
+ level, slot,
+ key->objectid);
+ b = read_node_slot(root, b, slot);
+ }
+ }
+ if (!p->skip_locking)
+ btrfs_tree_lock(b);
+ } else {
+ p->slots[level] = slot;
+ if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
+ sizeof(struct btrfs_item) + ins_len) {
+ int sret = split_leaf(trans, root, key,
+ p, ins_len, ret == 0);
+ BUG_ON(sret > 0);
+ if (sret) {
+ ret = sret;
+ goto done;
+ }
+ }
+ unlock_up(p, level, lowest_unlock);
+ goto done;
+ }
+ }
+ ret = 1;
+done:
+ if (prealloc_block.objectid) {
+ btrfs_free_reserved_extent(root,
+ prealloc_block.objectid,
+ prealloc_block.offset);
+ }
+
+ return ret;
+}
+
+int btrfs_merge_path(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_key *node_keys,
+ u64 *nodes, int lowest_level)
+{
+ struct extent_buffer *eb;
+ struct extent_buffer *parent;
+ struct btrfs_key key;
+ u64 bytenr;
+ u64 generation;
+ u32 blocksize;
+ int level;
+ int slot;
+ int key_match;
+ int ret;
+
+ eb = btrfs_lock_root_node(root);
+ ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0);
+ BUG_ON(ret);
+
+ parent = eb;
+ while (1) {
+ level = btrfs_header_level(parent);
+ if (level == 0 || level <= lowest_level)
+ break;
+
+ ret = bin_search(parent, &node_keys[lowest_level], level,
+ &slot);
+ if (ret && slot > 0)
+ slot--;
+
+ bytenr = btrfs_node_blockptr(parent, slot);
+ if (nodes[level - 1] == bytenr)
+ break;
+
+ blocksize = btrfs_level_size(root, level - 1);
+ generation = btrfs_node_ptr_generation(parent, slot);
+ btrfs_node_key_to_cpu(eb, &key, slot);
+ key_match = !memcmp(&key, &node_keys[level - 1], sizeof(key));
+
+ if (generation == trans->transid) {
+ eb = read_tree_block(root, bytenr, blocksize,
+ generation);
+ btrfs_tree_lock(eb);
+ }
+
+ /*
+ * if node keys match and node pointer hasn't been modified
+ * in the running transaction, we can merge the path. for
+ * blocks owened by reloc trees, the node pointer check is
+ * skipped, this is because these blocks are fully controlled
+ * by the space balance code, no one else can modify them.
+ */
+ if (!nodes[level - 1] || !key_match ||
+ (generation == trans->transid &&
+ btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID)) {
+ if (level == 1 || level == lowest_level + 1) {
+ if (generation == trans->transid) {
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+ }
+ break;
+ }
+
+ if (generation != trans->transid) {
+ eb = read_tree_block(root, bytenr, blocksize,
+ generation);
+ btrfs_tree_lock(eb);
+ }
+
+ ret = btrfs_cow_block(trans, root, eb, parent, slot,
+ &eb, 0);
+ BUG_ON(ret);
+
+ if (root->root_key.objectid ==
+ BTRFS_TREE_RELOC_OBJECTID) {
+ if (!nodes[level - 1]) {
+ nodes[level - 1] = eb->start;
+ memcpy(&node_keys[level - 1], &key,
+ sizeof(node_keys[0]));
+ } else {
+ WARN_ON(1);
+ }
+ }
+
+ btrfs_tree_unlock(parent);
+ free_extent_buffer(parent);
+ parent = eb;
+ continue;
+ }
+
+ btrfs_set_node_blockptr(parent, slot, nodes[level - 1]);
+ btrfs_set_node_ptr_generation(parent, slot, trans->transid);
+ btrfs_mark_buffer_dirty(parent);
+
+ ret = btrfs_inc_extent_ref(trans, root,
+ nodes[level - 1],
+ blocksize, parent->start,
+ btrfs_header_owner(parent),
+ btrfs_header_generation(parent),
+ level - 1);
+ BUG_ON(ret);
+
+ /*
+ * If the block was created in the running transaction,
+ * it's possible this is the last reference to it, so we
+ * should drop the subtree.
+ */
+ if (generation == trans->transid) {
+ ret = btrfs_drop_subtree(trans, root, eb, parent);
+ BUG_ON(ret);
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+ } else {
+ ret = btrfs_free_extent(trans, root, bytenr,
+ blocksize, parent->start,
+ btrfs_header_owner(parent),
+ btrfs_header_generation(parent),
+ level - 1, 1);
+ BUG_ON(ret);
+ }
+ break;
+ }
+ btrfs_tree_unlock(parent);
+ free_extent_buffer(parent);
+ return 0;
+}
+
+/*
+ * adjust the pointers going up the tree, starting at level
+ * making sure the right key of each node is points to 'key'.
+ * This is used after shifting pointers to the left, so it stops
+ * fixing up pointers when a given leaf/node is not in slot 0 of the
+ * higher levels
+ *
+ * If this fails to write a tree block, it returns -1, but continues
+ * fixing up the blocks in ram so the tree is consistent.
+ */
+static int fixup_low_keys(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_disk_key *key, int level)
+{
+ int i;
+ int ret = 0;
+ struct extent_buffer *t;
+
+ for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+ int tslot = path->slots[i];
+ if (!path->nodes[i])
+ break;
+ t = path->nodes[i];
+ btrfs_set_node_key(t, key, tslot);
+ btrfs_mark_buffer_dirty(path->nodes[i]);
+ if (tslot != 0)
+ break;
+ }
+ return ret;
+}
+
+/*
+ * update item key.
+ *
+ * This function isn't completely safe. It's the caller's responsibility
+ * that the new key won't break the order
+ */
+int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *new_key)
+{
+ struct btrfs_disk_key disk_key;
+ struct extent_buffer *eb;
+ int slot;
+
+ eb = path->nodes[0];
+ slot = path->slots[0];
+ if (slot > 0) {
+ btrfs_item_key(eb, &disk_key, slot - 1);
+ if (comp_keys(&disk_key, new_key) >= 0)
+ return -1;
+ }
+ if (slot < btrfs_header_nritems(eb) - 1) {
+ btrfs_item_key(eb, &disk_key, slot + 1);
+ if (comp_keys(&disk_key, new_key) <= 0)
+ return -1;
+ }
+
+ btrfs_cpu_key_to_disk(&disk_key, new_key);
+ btrfs_set_item_key(eb, &disk_key, slot);
+ btrfs_mark_buffer_dirty(eb);
+ if (slot == 0)
+ fixup_low_keys(trans, root, path, &disk_key, 1);
+ return 0;
+}
+
+/*
+ * try to push data from one node into the next node left in the
+ * tree.
+ *
+ * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
+ * error, and > 0 if there was no room in the left hand block.
+ */
+static int push_node_left(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *dst,
+ struct extent_buffer *src, int empty)
+{
+ int push_items = 0;
+ int src_nritems;
+ int dst_nritems;
+ int ret = 0;
+
+ src_nritems = btrfs_header_nritems(src);
+ dst_nritems = btrfs_header_nritems(dst);
+ push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
+ WARN_ON(btrfs_header_generation(src) != trans->transid);
+ WARN_ON(btrfs_header_generation(dst) != trans->transid);
+
+ if (!empty && src_nritems <= 8)
+ return 1;
+
+ if (push_items <= 0) {
+ return 1;
+ }
+
+ if (empty) {
+ push_items = min(src_nritems, push_items);
+ if (push_items < src_nritems) {
+ /* leave at least 8 pointers in the node if
+ * we aren't going to empty it
+ */
+ if (src_nritems - push_items < 8) {
+ if (push_items <= 8)
+ return 1;
+ push_items -= 8;
+ }
+ }
+ } else
+ push_items = min(src_nritems - 8, push_items);
+
+ copy_extent_buffer(dst, src,
+ btrfs_node_key_ptr_offset(dst_nritems),
+ btrfs_node_key_ptr_offset(0),
+ push_items * sizeof(struct btrfs_key_ptr));
+
+ if (push_items < src_nritems) {
+ memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
+ btrfs_node_key_ptr_offset(push_items),
+ (src_nritems - push_items) *
+ sizeof(struct btrfs_key_ptr));
+ }
+ btrfs_set_header_nritems(src, src_nritems - push_items);
+ btrfs_set_header_nritems(dst, dst_nritems + push_items);
+ btrfs_mark_buffer_dirty(src);
+ btrfs_mark_buffer_dirty(dst);
+
+ ret = btrfs_update_ref(trans, root, src, dst, dst_nritems, push_items);
+ BUG_ON(ret);
+
+ return ret;
+}
+
+/*
+ * try to push data from one node into the next node right in the
+ * tree.
+ *
+ * returns 0 if some ptrs were pushed, < 0 if there was some horrible
+ * error, and > 0 if there was no room in the right hand block.
+ *
+ * this will only push up to 1/2 the contents of the left node over
+ */
+static int balance_node_right(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *dst,
+ struct extent_buffer *src)
+{
+ int push_items = 0;
+ int max_push;
+ int src_nritems;
+ int dst_nritems;
+ int ret = 0;
+
+ WARN_ON(btrfs_header_generation(src) != trans->transid);
+ WARN_ON(btrfs_header_generation(dst) != trans->transid);
+
+ src_nritems = btrfs_header_nritems(src);
+ dst_nritems = btrfs_header_nritems(dst);
+ push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
+ if (push_items <= 0) {
+ return 1;
+ }
+
+ if (src_nritems < 4) {
+ return 1;
+ }
+
+ max_push = src_nritems / 2 + 1;
+ /* don't try to empty the node */
+ if (max_push >= src_nritems) {
+ return 1;
+ }
+
+ if (max_push < push_items)
+ push_items = max_push;
+
+ memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
+ btrfs_node_key_ptr_offset(0),
+ (dst_nritems) *
+ sizeof(struct btrfs_key_ptr));
+
+ copy_extent_buffer(dst, src,
+ btrfs_node_key_ptr_offset(0),
+ btrfs_node_key_ptr_offset(src_nritems - push_items),
+ push_items * sizeof(struct btrfs_key_ptr));
+
+ btrfs_set_header_nritems(src, src_nritems - push_items);
+ btrfs_set_header_nritems(dst, dst_nritems + push_items);
+
+ btrfs_mark_buffer_dirty(src);
+ btrfs_mark_buffer_dirty(dst);
+
+ ret = btrfs_update_ref(trans, root, src, dst, 0, push_items);
+ BUG_ON(ret);
+
+ return ret;
+}
+
+/*
+ * helper function to insert a new root level in the tree.
+ * A new node is allocated, and a single item is inserted to
+ * point to the existing root
+ *
+ * returns zero on success or < 0 on failure.
+ */
+static int noinline insert_new_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int level)
+{
+ u64 lower_gen;
+ struct extent_buffer *lower;
+ struct extent_buffer *c;
+ struct extent_buffer *old;
+ struct btrfs_disk_key lower_key;
+ int ret;
+
+ BUG_ON(path->nodes[level]);
+ BUG_ON(path->nodes[level-1] != root->node);
+
+ lower = path->nodes[level-1];
+ if (level == 1)
+ btrfs_item_key(lower, &lower_key, 0);
+ else
+ btrfs_node_key(lower, &lower_key, 0);
+
+ c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
+ root->root_key.objectid, trans->transid,
+ level, root->node->start, 0);
+ if (IS_ERR(c))
+ return PTR_ERR(c);
+
+ memset_extent_buffer(c, 0, 0, root->nodesize);
+ btrfs_set_header_nritems(c, 1);
+ btrfs_set_header_level(c, level);
+ btrfs_set_header_bytenr(c, c->start);
+ btrfs_set_header_generation(c, trans->transid);
+ btrfs_set_header_owner(c, root->root_key.objectid);
+
+ write_extent_buffer(c, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(c),
+ BTRFS_FSID_SIZE);
+
+ write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
+ (unsigned long)btrfs_header_chunk_tree_uuid(c),
+ BTRFS_UUID_SIZE);
+
+ btrfs_set_node_key(c, &lower_key, 0);
+ btrfs_set_node_blockptr(c, 0, lower->start);
+ lower_gen = btrfs_header_generation(lower);
+ WARN_ON(lower_gen != trans->transid);
+
+ btrfs_set_node_ptr_generation(c, 0, lower_gen);
+
+ btrfs_mark_buffer_dirty(c);
+
+ spin_lock(&root->node_lock);
+ old = root->node;
+ root->node = c;
+ spin_unlock(&root->node_lock);
+
+ ret = btrfs_update_extent_ref(trans, root, lower->start,
+ lower->start, c->start,
+ root->root_key.objectid,
+ trans->transid, level - 1);
+ BUG_ON(ret);
+
+ /* the super has an extra ref to root->node */
+ free_extent_buffer(old);
+
+ add_root_to_dirty_list(root);
+ extent_buffer_get(c);
+ path->nodes[level] = c;
+ path->locks[level] = 1;
+ path->slots[level] = 0;
+ return 0;
+}
+
+/*
+ * worker function to insert a single pointer in a node.
+ * the node should have enough room for the pointer already
+ *
+ * slot and level indicate where you want the key to go, and
+ * blocknr is the block the key points to.
+ *
+ * returns zero on success and < 0 on any error
+ */
+static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, struct btrfs_disk_key
+ *key, u64 bytenr, int slot, int level)
+{
+ struct extent_buffer *lower;
+ int nritems;
+
+ BUG_ON(!path->nodes[level]);
+ lower = path->nodes[level];
+ nritems = btrfs_header_nritems(lower);
+ if (slot > nritems)
+ BUG();
+ if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
+ BUG();
+ if (slot != nritems) {
+ memmove_extent_buffer(lower,
+ btrfs_node_key_ptr_offset(slot + 1),
+ btrfs_node_key_ptr_offset(slot),
+ (nritems - slot) * sizeof(struct btrfs_key_ptr));
+ }
+ btrfs_set_node_key(lower, key, slot);
+ btrfs_set_node_blockptr(lower, slot, bytenr);
+ WARN_ON(trans->transid == 0);
+ btrfs_set_node_ptr_generation(lower, slot, trans->transid);
+ btrfs_set_header_nritems(lower, nritems + 1);
+ btrfs_mark_buffer_dirty(lower);
+ return 0;
+}
+
+/*
+ * split the node at the specified level in path in two.
+ * The path is corrected to point to the appropriate node after the split
+ *
+ * Before splitting this tries to make some room in the node by pushing
+ * left and right, if either one works, it returns right away.
+ *
+ * returns 0 on success and < 0 on failure
+ */
+static noinline int split_node(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int level)
+{
+ struct extent_buffer *c;
+ struct extent_buffer *split;
+ struct btrfs_disk_key disk_key;
+ int mid;
+ int ret;
+ int wret;
+ u32 c_nritems;
+
+ c = path->nodes[level];
+ WARN_ON(btrfs_header_generation(c) != trans->transid);
+ if (c == root->node) {
+ /* trying to split the root, lets make a new one */
+ ret = insert_new_root(trans, root, path, level + 1);
+ if (ret)
+ return ret;
+ } else {
+ ret = push_nodes_for_insert(trans, root, path, level);
+ c = path->nodes[level];
+ if (!ret && btrfs_header_nritems(c) <
+ BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
+ return 0;
+ if (ret < 0)
+ return ret;
+ }
+
+ c_nritems = btrfs_header_nritems(c);
+
+ split = btrfs_alloc_free_block(trans, root, root->nodesize,
+ path->nodes[level + 1]->start,
+ root->root_key.objectid,
+ trans->transid, level, c->start, 0);
+ if (IS_ERR(split))
+ return PTR_ERR(split);
+
+ btrfs_set_header_flags(split, btrfs_header_flags(c));
+ btrfs_set_header_level(split, btrfs_header_level(c));
+ btrfs_set_header_bytenr(split, split->start);
+ btrfs_set_header_generation(split, trans->transid);
+ btrfs_set_header_owner(split, root->root_key.objectid);
+ btrfs_set_header_flags(split, 0);
+ write_extent_buffer(split, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(split),
+ BTRFS_FSID_SIZE);
+ write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
+ (unsigned long)btrfs_header_chunk_tree_uuid(split),
+ BTRFS_UUID_SIZE);
+
+ mid = (c_nritems + 1) / 2;
+
+ copy_extent_buffer(split, c,
+ btrfs_node_key_ptr_offset(0),
+ btrfs_node_key_ptr_offset(mid),
+ (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
+ btrfs_set_header_nritems(split, c_nritems - mid);
+ btrfs_set_header_nritems(c, mid);
+ ret = 0;
+
+ btrfs_mark_buffer_dirty(c);
+ btrfs_mark_buffer_dirty(split);
+
+ btrfs_node_key(split, &disk_key, 0);
+ wret = insert_ptr(trans, root, path, &disk_key, split->start,
+ path->slots[level + 1] + 1,
+ level + 1);
+ if (wret)
+ ret = wret;
+
+ ret = btrfs_update_ref(trans, root, c, split, 0, c_nritems - mid);
+ BUG_ON(ret);
+
+ if (path->slots[level] >= mid) {
+ path->slots[level] -= mid;
+ btrfs_tree_unlock(c);
+ free_extent_buffer(c);
+ path->nodes[level] = split;
+ path->slots[level + 1] += 1;
+ } else {
+ btrfs_tree_unlock(split);
+ free_extent_buffer(split);
+ }
+ return ret;
+}
+
+/*
+ * how many bytes are required to store the items in a leaf. start
+ * and nr indicate which items in the leaf to check. This totals up the
+ * space used both by the item structs and the item data
+ */
+static int leaf_space_used(struct extent_buffer *l, int start, int nr)
+{
+ int data_len;
+ int nritems = btrfs_header_nritems(l);
+ int end = min(nritems, start + nr) - 1;
+
+ if (!nr)
+ return 0;
+ data_len = btrfs_item_end_nr(l, start);
+ data_len = data_len - btrfs_item_offset_nr(l, end);
+ data_len += sizeof(struct btrfs_item) * nr;
+ WARN_ON(data_len < 0);
+ return data_len;
+}
+
+/*
+ * The space between the end of the leaf items and
+ * the start of the leaf data. IOW, how much room
+ * the leaf has left for both items and data
+ */
+int noinline btrfs_leaf_free_space(struct btrfs_root *root,
+ struct extent_buffer *leaf)
+{
+ int nritems = btrfs_header_nritems(leaf);
+ int ret;
+ ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
+ if (ret < 0) {
+ printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
+ ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
+ leaf_space_used(leaf, 0, nritems), nritems);
+ }
+ return ret;
+}
+
+/*
+ * push some data in the path leaf to the right, trying to free up at
+ * least data_size bytes. returns zero if the push worked, nonzero otherwise
+ *
+ * returns 1 if the push failed because the other node didn't have enough
+ * room, 0 if everything worked out and < 0 if there were major errors.
+ */
+static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, int data_size,
+ int empty)
+{
+ struct extent_buffer *left = path->nodes[0];
+ struct extent_buffer *right;
+ struct extent_buffer *upper;
+ struct btrfs_disk_key disk_key;
+ int slot;
+ u32 i;
+ int free_space;
+ int push_space = 0;
+ int push_items = 0;
+ struct btrfs_item *item;
+ u32 left_nritems;
+ u32 nr;
+ u32 right_nritems;
+ u32 data_end;
+ u32 this_item_size;
+ int ret;
+
+ slot = path->slots[1];
+ if (!path->nodes[1]) {
+ return 1;
+ }
+ upper = path->nodes[1];
+ if (slot >= btrfs_header_nritems(upper) - 1)
+ return 1;
+
+ WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+
+ right = read_node_slot(root, upper, slot + 1);
+ btrfs_tree_lock(right);
+ free_space = btrfs_leaf_free_space(root, right);
+ if (free_space < data_size + sizeof(struct btrfs_item))
+ goto out_unlock;
+
+ /* cow and double check */
+ ret = btrfs_cow_block(trans, root, right, upper,
+ slot + 1, &right, 0);
+ if (ret)
+ goto out_unlock;
+
+ free_space = btrfs_leaf_free_space(root, right);
+ if (free_space < data_size + sizeof(struct btrfs_item))
+ goto out_unlock;
+
+ left_nritems = btrfs_header_nritems(left);
+ if (left_nritems == 0)
+ goto out_unlock;
+
+ if (empty)
+ nr = 0;
+ else
+ nr = 1;
+
+ if (path->slots[0] >= left_nritems)
+ push_space += data_size + sizeof(*item);
+
+ i = left_nritems - 1;
+ while (i >= nr) {
+ item = btrfs_item_nr(left, i);
+
+ if (!empty && push_items > 0) {
+ if (path->slots[0] > i)
+ break;
+ if (path->slots[0] == i) {
+ int space = btrfs_leaf_free_space(root, left);
+ if (space + push_space * 2 > free_space)
+ break;
+ }
+ }
+
+ if (path->slots[0] == i)
+ push_space += data_size + sizeof(*item);
+
+ if (!left->map_token) {
+ map_extent_buffer(left, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &left->map_token, &left->kaddr,
+ &left->map_start, &left->map_len,
+ KM_USER1);
+ }
+
+ this_item_size = btrfs_item_size(left, item);
+ if (this_item_size + sizeof(*item) + push_space > free_space)
+ break;
+
+ push_items++;
+ push_space += this_item_size + sizeof(*item);
+ if (i == 0)
+ break;
+ i--;
+ }
+ if (left->map_token) {
+ unmap_extent_buffer(left, left->map_token, KM_USER1);
+ left->map_token = NULL;
+ }
+
+ if (push_items == 0)
+ goto out_unlock;
+
+ if (!empty && push_items == left_nritems)
+ WARN_ON(1);
+
+ /* push left to right */
+ right_nritems = btrfs_header_nritems(right);
+
+ push_space = btrfs_item_end_nr(left, left_nritems - push_items);
+ push_space -= leaf_data_end(root, left);
+
+ /* make room in the right data area */
+ data_end = leaf_data_end(root, right);
+ memmove_extent_buffer(right,
+ btrfs_leaf_data(right) + data_end - push_space,
+ btrfs_leaf_data(right) + data_end,
+ BTRFS_LEAF_DATA_SIZE(root) - data_end);
+
+ /* copy from the left data area */
+ copy_extent_buffer(right, left, btrfs_leaf_data(right) +
+ BTRFS_LEAF_DATA_SIZE(root) - push_space,
+ btrfs_leaf_data(left) + leaf_data_end(root, left),
+ push_space);
+
+ memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
+ btrfs_item_nr_offset(0),
+ right_nritems * sizeof(struct btrfs_item));
+
+ /* copy the items from left to right */
+ copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
+ btrfs_item_nr_offset(left_nritems - push_items),
+ push_items * sizeof(struct btrfs_item));
+
+ /* update the item pointers */
+ right_nritems += push_items;
+ btrfs_set_header_nritems(right, right_nritems);
+ push_space = BTRFS_LEAF_DATA_SIZE(root);
+ for (i = 0; i < right_nritems; i++) {
+ item = btrfs_item_nr(right, i);
+ if (!right->map_token) {
+ map_extent_buffer(right, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &right->map_token, &right->kaddr,
+ &right->map_start, &right->map_len,
+ KM_USER1);
+ }
+ push_space -= btrfs_item_size(right, item);
+ btrfs_set_item_offset(right, item, push_space);
+ }
+
+ if (right->map_token) {
+ unmap_extent_buffer(right, right->map_token, KM_USER1);
+ right->map_token = NULL;
+ }
+ left_nritems -= push_items;
+ btrfs_set_header_nritems(left, left_nritems);
+
+ if (left_nritems)
+ btrfs_mark_buffer_dirty(left);
+ btrfs_mark_buffer_dirty(right);
+
+ ret = btrfs_update_ref(trans, root, left, right, 0, push_items);
+ BUG_ON(ret);
+
+ btrfs_item_key(right, &disk_key, 0);
+ btrfs_set_node_key(upper, &disk_key, slot + 1);
+ btrfs_mark_buffer_dirty(upper);
+
+ /* then fixup the leaf pointer in the path */
+ if (path->slots[0] >= left_nritems) {
+ path->slots[0] -= left_nritems;
+ if (btrfs_header_nritems(path->nodes[0]) == 0)
+ clean_tree_block(trans, root, path->nodes[0]);
+ btrfs_tree_unlock(path->nodes[0]);
+ free_extent_buffer(path->nodes[0]);
+ path->nodes[0] = right;
+ path->slots[1] += 1;
+ } else {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ }
+ return 0;
+
+out_unlock:
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return 1;
+}
+
+/*
+ * push some data in the path leaf to the left, trying to free up at
+ * least data_size bytes. returns zero if the push worked, nonzero otherwise
+ */
+static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, int data_size,
+ int empty)
+{
+ struct btrfs_disk_key disk_key;
+ struct extent_buffer *right = path->nodes[0];
+ struct extent_buffer *left;
+ int slot;
+ int i;
+ int free_space;
+ int push_space = 0;
+ int push_items = 0;
+ struct btrfs_item *item;
+ u32 old_left_nritems;
+ u32 right_nritems;
+ u32 nr;
+ int ret = 0;
+ int wret;
+ u32 this_item_size;
+ u32 old_left_item_size;
+
+ slot = path->slots[1];
+ if (slot == 0)
+ return 1;
+ if (!path->nodes[1])
+ return 1;
+
+ right_nritems = btrfs_header_nritems(right);
+ if (right_nritems == 0) {
+ return 1;
+ }
+
+ WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+
+ left = read_node_slot(root, path->nodes[1], slot - 1);
+ btrfs_tree_lock(left);
+ free_space = btrfs_leaf_free_space(root, left);
+ if (free_space < data_size + sizeof(struct btrfs_item)) {
+ ret = 1;
+ goto out;
+ }
+
+ /* cow and double check */
+ ret = btrfs_cow_block(trans, root, left,
+ path->nodes[1], slot - 1, &left, 0);
+ if (ret) {
+ /* we hit -ENOSPC, but it isn't fatal here */
+ ret = 1;
+ goto out;
+ }
+
+ free_space = btrfs_leaf_free_space(root, left);
+ if (free_space < data_size + sizeof(struct btrfs_item)) {
+ ret = 1;
+ goto out;
+ }
+
+ if (empty)
+ nr = right_nritems;
+ else
+ nr = right_nritems - 1;
+
+ for (i = 0; i < nr; i++) {
+ item = btrfs_item_nr(right, i);
+ if (!right->map_token) {
+ map_extent_buffer(right, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &right->map_token, &right->kaddr,
+ &right->map_start, &right->map_len,
+ KM_USER1);
+ }
+
+ if (!empty && push_items > 0) {
+ if (path->slots[0] < i)
+ break;
+ if (path->slots[0] == i) {
+ int space = btrfs_leaf_free_space(root, right);
+ if (space + push_space * 2 > free_space)
+ break;
+ }
+ }
+
+ if (path->slots[0] == i)
+ push_space += data_size + sizeof(*item);
+
+ this_item_size = btrfs_item_size(right, item);
+ if (this_item_size + sizeof(*item) + push_space > free_space)
+ break;
+
+ push_items++;
+ push_space += this_item_size + sizeof(*item);
+ }
+
+ if (right->map_token) {
+ unmap_extent_buffer(right, right->map_token, KM_USER1);
+ right->map_token = NULL;
+ }
+
+ if (push_items == 0) {
+ ret = 1;
+ goto out;
+ }
+ if (!empty && push_items == btrfs_header_nritems(right))
+ WARN_ON(1);
+
+ /* push data from right to left */
+ copy_extent_buffer(left, right,
+ btrfs_item_nr_offset(btrfs_header_nritems(left)),
+ btrfs_item_nr_offset(0),
+ push_items * sizeof(struct btrfs_item));
+
+ push_space = BTRFS_LEAF_DATA_SIZE(root) -
+ btrfs_item_offset_nr(right, push_items -1);
+
+ copy_extent_buffer(left, right, btrfs_leaf_data(left) +
+ leaf_data_end(root, left) - push_space,
+ btrfs_leaf_data(right) +
+ btrfs_item_offset_nr(right, push_items - 1),
+ push_space);
+ old_left_nritems = btrfs_header_nritems(left);
+ BUG_ON(old_left_nritems < 0);
+
+ old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
+ for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
+ u32 ioff;
+
+ item = btrfs_item_nr(left, i);
+ if (!left->map_token) {
+ map_extent_buffer(left, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &left->map_token, &left->kaddr,
+ &left->map_start, &left->map_len,
+ KM_USER1);
+ }
+
+ ioff = btrfs_item_offset(left, item);
+ btrfs_set_item_offset(left, item,
+ ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
+ }
+ btrfs_set_header_nritems(left, old_left_nritems + push_items);
+ if (left->map_token) {
+ unmap_extent_buffer(left, left->map_token, KM_USER1);
+ left->map_token = NULL;
+ }
+
+ /* fixup right node */
+ if (push_items > right_nritems) {
+ printk("push items %d nr %u\n", push_items, right_nritems);
+ WARN_ON(1);
+ }
+
+ if (push_items < right_nritems) {
+ push_space = btrfs_item_offset_nr(right, push_items - 1) -
+ leaf_data_end(root, right);
+ memmove_extent_buffer(right, btrfs_leaf_data(right) +
+ BTRFS_LEAF_DATA_SIZE(root) - push_space,
+ btrfs_leaf_data(right) +
+ leaf_data_end(root, right), push_space);
+
+ memmove_extent_buffer(right, btrfs_item_nr_offset(0),
+ btrfs_item_nr_offset(push_items),
+ (btrfs_header_nritems(right) - push_items) *
+ sizeof(struct btrfs_item));
+ }
+ right_nritems -= push_items;
+ btrfs_set_header_nritems(right, right_nritems);
+ push_space = BTRFS_LEAF_DATA_SIZE(root);
+ for (i = 0; i < right_nritems; i++) {
+ item = btrfs_item_nr(right, i);
+
+ if (!right->map_token) {
+ map_extent_buffer(right, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &right->map_token, &right->kaddr,
+ &right->map_start, &right->map_len,
+ KM_USER1);
+ }
+
+ push_space = push_space - btrfs_item_size(right, item);
+ btrfs_set_item_offset(right, item, push_space);
+ }
+ if (right->map_token) {
+ unmap_extent_buffer(right, right->map_token, KM_USER1);
+ right->map_token = NULL;
+ }
+
+ btrfs_mark_buffer_dirty(left);
+ if (right_nritems)
+ btrfs_mark_buffer_dirty(right);
+
+ ret = btrfs_update_ref(trans, root, right, left,
+ old_left_nritems, push_items);
+ BUG_ON(ret);
+
+ btrfs_item_key(right, &disk_key, 0);
+ wret = fixup_low_keys(trans, root, path, &disk_key, 1);
+ if (wret)
+ ret = wret;
+
+ /* then fixup the leaf pointer in the path */
+ if (path->slots[0] < push_items) {
+ path->slots[0] += old_left_nritems;
+ if (btrfs_header_nritems(path->nodes[0]) == 0)
+ clean_tree_block(trans, root, path->nodes[0]);
+ btrfs_tree_unlock(path->nodes[0]);
+ free_extent_buffer(path->nodes[0]);
+ path->nodes[0] = left;
+ path->slots[1] -= 1;
+ } else {
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ path->slots[0] -= push_items;
+ }
+ BUG_ON(path->slots[0] < 0);
+ return ret;
+out:
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ return ret;
+}
+
+/*
+ * split the path's leaf in two, making sure there is at least data_size
+ * available for the resulting leaf level of the path.
+ *
+ * returns 0 if all went well and < 0 on failure.
+ */
+static noinline int split_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_key *ins_key,
+ struct btrfs_path *path, int data_size,
+ int extend)
+{
+ struct extent_buffer *l;
+ u32 nritems;
+ int mid;
+ int slot;
+ struct extent_buffer *right;
+ int space_needed = data_size + sizeof(struct btrfs_item);
+ int data_copy_size;
+ int rt_data_off;
+ int i;
+ int ret = 0;
+ int wret;
+ int double_split;
+ int num_doubles = 0;
+ struct btrfs_disk_key disk_key;
+
+ if (extend)
+ space_needed = data_size;
+
+ /* first try to make some room by pushing left and right */
+ if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
+ wret = push_leaf_right(trans, root, path, data_size, 0);
+ if (wret < 0) {
+ return wret;
+ }
+ if (wret) {
+ wret = push_leaf_left(trans, root, path, data_size, 0);
+ if (wret < 0)
+ return wret;
+ }
+ l = path->nodes[0];
+
+ /* did the pushes work? */
+ if (btrfs_leaf_free_space(root, l) >= space_needed)
+ return 0;
+ }
+
+ if (!path->nodes[1]) {
+ ret = insert_new_root(trans, root, path, 1);
+ if (ret)
+ return ret;
+ }
+again:
+ double_split = 0;
+ l = path->nodes[0];
+ slot = path->slots[0];
+ nritems = btrfs_header_nritems(l);
+ mid = (nritems + 1)/ 2;
+
+ right = btrfs_alloc_free_block(trans, root, root->leafsize,
+ path->nodes[1]->start,
+ root->root_key.objectid,
+ trans->transid, 0, l->start, 0);
+ if (IS_ERR(right)) {
+ BUG_ON(1);
+ return PTR_ERR(right);
+ }
+
+ memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
+ btrfs_set_header_bytenr(right, right->start);
+ btrfs_set_header_generation(right, trans->transid);
+ btrfs_set_header_owner(right, root->root_key.objectid);
+ btrfs_set_header_level(right, 0);
+ write_extent_buffer(right, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(right),
+ BTRFS_FSID_SIZE);
+
+ write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
+ (unsigned long)btrfs_header_chunk_tree_uuid(right),
+ BTRFS_UUID_SIZE);
+ if (mid <= slot) {
+ if (nritems == 1 ||
+ leaf_space_used(l, mid, nritems - mid) + space_needed >
+ BTRFS_LEAF_DATA_SIZE(root)) {
+ if (slot >= nritems) {
+ btrfs_cpu_key_to_disk(&disk_key, ins_key);
+ btrfs_set_header_nritems(right, 0);
+ wret = insert_ptr(trans, root, path,
+ &disk_key, right->start,
+ path->slots[1] + 1, 1);
+ if (wret)
+ ret = wret;
+
+ btrfs_tree_unlock(path->nodes[0]);
+ free_extent_buffer(path->nodes[0]);
+ path->nodes[0] = right;
+ path->slots[0] = 0;
+ path->slots[1] += 1;
+ btrfs_mark_buffer_dirty(right);
+ return ret;
+ }
+ mid = slot;
+ if (mid != nritems &&
+ leaf_space_used(l, mid, nritems - mid) +
+ space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
+ double_split = 1;
+ }
+ }
+ } else {
+ if (leaf_space_used(l, 0, mid + 1) + space_needed >
+ BTRFS_LEAF_DATA_SIZE(root)) {
+ if (!extend && slot == 0) {
+ btrfs_cpu_key_to_disk(&disk_key, ins_key);
+ btrfs_set_header_nritems(right, 0);
+ wret = insert_ptr(trans, root, path,
+ &disk_key,
+ right->start,
+ path->slots[1], 1);
+ if (wret)
+ ret = wret;
+ btrfs_tree_unlock(path->nodes[0]);
+ free_extent_buffer(path->nodes[0]);
+ path->nodes[0] = right;
+ path->slots[0] = 0;
+ if (path->slots[1] == 0) {
+ wret = fixup_low_keys(trans, root,
+ path, &disk_key, 1);
+ if (wret)
+ ret = wret;
+ }
+ btrfs_mark_buffer_dirty(right);
+ return ret;
+ } else if (extend && slot == 0) {
+ mid = 1;
+ } else {
+ mid = slot;
+ if (mid != nritems &&
+ leaf_space_used(l, mid, nritems - mid) +
+ space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
+ double_split = 1;
+ }
+ }
+ }
+ }
+ nritems = nritems - mid;
+ btrfs_set_header_nritems(right, nritems);
+ data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
+
+ copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
+ btrfs_item_nr_offset(mid),
+ nritems * sizeof(struct btrfs_item));
+
+ copy_extent_buffer(right, l,
+ btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
+ data_copy_size, btrfs_leaf_data(l) +
+ leaf_data_end(root, l), data_copy_size);
+
+ rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
+ btrfs_item_end_nr(l, mid);
+
+ for (i = 0; i < nritems; i++) {
+ struct btrfs_item *item = btrfs_item_nr(right, i);
+ u32 ioff;
+
+ if (!right->map_token) {
+ map_extent_buffer(right, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &right->map_token, &right->kaddr,
+ &right->map_start, &right->map_len,
+ KM_USER1);
+ }
+
+ ioff = btrfs_item_offset(right, item);
+ btrfs_set_item_offset(right, item, ioff + rt_data_off);
+ }
+
+ if (right->map_token) {
+ unmap_extent_buffer(right, right->map_token, KM_USER1);
+ right->map_token = NULL;
+ }
+
+ btrfs_set_header_nritems(l, mid);
+ ret = 0;
+ btrfs_item_key(right, &disk_key, 0);
+ wret = insert_ptr(trans, root, path, &disk_key, right->start,
+ path->slots[1] + 1, 1);
+ if (wret)
+ ret = wret;
+
+ btrfs_mark_buffer_dirty(right);
+ btrfs_mark_buffer_dirty(l);
+ BUG_ON(path->slots[0] != slot);
+
+ ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
+ BUG_ON(ret);
+
+ if (mid <= slot) {
+ btrfs_tree_unlock(path->nodes[0]);
+ free_extent_buffer(path->nodes[0]);
+ path->nodes[0] = right;
+ path->slots[0] -= mid;
+ path->slots[1] += 1;
+ } else {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ }
+
+ BUG_ON(path->slots[0] < 0);
+
+ if (double_split) {
+ BUG_ON(num_doubles != 0);
+ num_doubles++;
+ goto again;
+ }
+ return ret;
+}
+
+/*
+ * make the item pointed to by the path smaller. new_size indicates
+ * how small to make it, and from_end tells us if we just chop bytes
+ * off the end of the item or if we shift the item to chop bytes off
+ * the front.
+ */
+int btrfs_truncate_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u32 new_size, int from_end)
+{
+ int ret = 0;
+ int slot;
+ int slot_orig;
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ u32 nritems;
+ unsigned int data_end;
+ unsigned int old_data_start;
+ unsigned int old_size;
+ unsigned int size_diff;
+ int i;
+
+ slot_orig = path->slots[0];
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+
+ old_size = btrfs_item_size_nr(leaf, slot);
+ if (old_size == new_size)
+ return 0;
+
+ nritems = btrfs_header_nritems(leaf);
+ data_end = leaf_data_end(root, leaf);
+
+ old_data_start = btrfs_item_offset_nr(leaf, slot);
+
+ size_diff = old_size - new_size;
+
+ BUG_ON(slot < 0);
+ BUG_ON(slot >= nritems);
+
+ /*
+ * item0..itemN ... dataN.offset..dataN.size .. data0.size
+ */
+ /* first correct the data pointers */
+ for (i = slot; i < nritems; i++) {
+ u32 ioff;
+ item = btrfs_item_nr(leaf, i);
+
+ if (!leaf->map_token) {
+ map_extent_buffer(leaf, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &leaf->map_token, &leaf->kaddr,
+ &leaf->map_start, &leaf->map_len,
+ KM_USER1);
+ }
+
+ ioff = btrfs_item_offset(leaf, item);
+ btrfs_set_item_offset(leaf, item, ioff + size_diff);
+ }
+
+ if (leaf->map_token) {
+ unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+ leaf->map_token = NULL;
+ }
+
+ /* shift the data */
+ if (from_end) {
+ memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+ data_end + size_diff, btrfs_leaf_data(leaf) +
+ data_end, old_data_start + new_size - data_end);
+ } else {
+ struct btrfs_disk_key disk_key;
+ u64 offset;
+
+ btrfs_item_key(leaf, &disk_key, slot);
+
+ if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
+ unsigned long ptr;
+ struct btrfs_file_extent_item *fi;
+
+ fi = btrfs_item_ptr(leaf, slot,
+ struct btrfs_file_extent_item);
+ fi = (struct btrfs_file_extent_item *)(
+ (unsigned long)fi - size_diff);
+
+ if (btrfs_file_extent_type(leaf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE) {
+ ptr = btrfs_item_ptr_offset(leaf, slot);
+ memmove_extent_buffer(leaf, ptr,
+ (unsigned long)fi,
+ offsetof(struct btrfs_file_extent_item,
+ disk_bytenr));
+ }
+ }
+
+ memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+ data_end + size_diff, btrfs_leaf_data(leaf) +
+ data_end, old_data_start - data_end);
+
+ offset = btrfs_disk_key_offset(&disk_key);
+ btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
+ btrfs_set_item_key(leaf, &disk_key, slot);
+ if (slot == 0)
+ fixup_low_keys(trans, root, path, &disk_key, 1);
+ }
+
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_set_item_size(leaf, item, new_size);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = 0;
+ if (btrfs_leaf_free_space(root, leaf) < 0) {
+ btrfs_print_leaf(root, leaf);
+ BUG();
+ }
+ return ret;
+}
+
+/*
+ * make the item pointed to by the path bigger, data_size is the new size.
+ */
+int btrfs_extend_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ u32 data_size)
+{
+ int ret = 0;
+ int slot;
+ int slot_orig;
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ u32 nritems;
+ unsigned int data_end;
+ unsigned int old_data;
+ unsigned int old_size;
+ int i;
+
+ slot_orig = path->slots[0];
+ leaf = path->nodes[0];
+
+ nritems = btrfs_header_nritems(leaf);
+ data_end = leaf_data_end(root, leaf);
+
+ if (btrfs_leaf_free_space(root, leaf) < data_size) {
+ btrfs_print_leaf(root, leaf);
+ BUG();
+ }
+ slot = path->slots[0];
+ old_data = btrfs_item_end_nr(leaf, slot);
+
+ BUG_ON(slot < 0);
+ if (slot >= nritems) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d too large, nritems %d\n", slot, nritems);
+ BUG_ON(1);
+ }
+
+ /*
+ * item0..itemN ... dataN.offset..dataN.size .. data0.size
+ */
+ /* first correct the data pointers */
+ for (i = slot; i < nritems; i++) {
+ u32 ioff;
+ item = btrfs_item_nr(leaf, i);
+
+ if (!leaf->map_token) {
+ map_extent_buffer(leaf, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &leaf->map_token, &leaf->kaddr,
+ &leaf->map_start, &leaf->map_len,
+ KM_USER1);
+ }
+ ioff = btrfs_item_offset(leaf, item);
+ btrfs_set_item_offset(leaf, item, ioff - data_size);
+ }
+
+ if (leaf->map_token) {
+ unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+ leaf->map_token = NULL;
+ }
+
+ /* shift the data */
+ memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+ data_end - data_size, btrfs_leaf_data(leaf) +
+ data_end, old_data - data_end);
+
+ data_end = old_data;
+ old_size = btrfs_item_size_nr(leaf, slot);
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_set_item_size(leaf, item, old_size + data_size);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = 0;
+ if (btrfs_leaf_free_space(root, leaf) < 0) {
+ btrfs_print_leaf(root, leaf);
+ BUG();
+ }
+ return ret;
+}
+
+/*
+ * Given a key and some data, insert items into the tree.
+ * This does all the path init required, making room in the tree if needed.
+ * Returns the number of keys that were inserted.
+ */
+int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *cpu_key, u32 *data_size,
+ int nr)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ int ret = 0;
+ int slot;
+ int i;
+ u32 nritems;
+ u32 total_data = 0;
+ u32 total_size = 0;
+ unsigned int data_end;
+ struct btrfs_disk_key disk_key;
+ struct btrfs_key found_key;
+
+ found_key.objectid = 0;
+ nr = min_t(int, nr, BTRFS_NODEPTRS_PER_BLOCK(root));
+
+ for (i = 0; i < nr; i++)
+ total_data += data_size[i];
+
+ total_data = min_t(u32, total_data, BTRFS_LEAF_DATA_SIZE(root));
+ total_size = total_data + (nr * sizeof(struct btrfs_item));
+ ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
+ if (ret == 0)
+ return -EEXIST;
+ if (ret < 0)
+ goto out;
+
+ leaf = path->nodes[0];
+
+ nritems = btrfs_header_nritems(leaf);
+ data_end = leaf_data_end(root, leaf);
+
+ if (btrfs_leaf_free_space(root, leaf) < total_size) {
+ for (i = nr; i >= 0; i--) {
+ total_data -= data_size[i];
+ total_size -= data_size[i] + sizeof(struct btrfs_item);
+ if (total_size < btrfs_leaf_free_space(root, leaf))
+ break;
+ }
+ nr = i;
+ }
+
+ slot = path->slots[0];
+ BUG_ON(slot < 0);
+
+ if (slot != nritems) {
+ unsigned int old_data = btrfs_item_end_nr(leaf, slot);
+
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ /* figure out how many keys we can insert in here */
+ total_data = data_size[0];
+ for (i = 1; i < nr; i++) {
+ if (comp_cpu_keys(&found_key, cpu_key + i) <= 0)
+ break;
+ total_data += data_size[i];
+ }
+ nr = i;
+
+ if (old_data < data_end) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d old_data %d data_end %d\n",
+ slot, old_data, data_end);
+ BUG_ON(1);
+ }
+ /*
+ * item0..itemN ... dataN.offset..dataN.size .. data0.size
+ */
+ /* first correct the data pointers */
+ WARN_ON(leaf->map_token);
+ for (i = slot; i < nritems; i++) {
+ u32 ioff;
+
+ item = btrfs_item_nr(leaf, i);
+ if (!leaf->map_token) {
+ map_extent_buffer(leaf, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &leaf->map_token, &leaf->kaddr,
+ &leaf->map_start, &leaf->map_len,
+ KM_USER1);
+ }
+
+ ioff = btrfs_item_offset(leaf, item);
+ btrfs_set_item_offset(leaf, item, ioff - total_data);
+ }
+ if (leaf->map_token) {
+ unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+ leaf->map_token = NULL;
+ }
+
+ /* shift the items */
+ memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
+ btrfs_item_nr_offset(slot),
+ (nritems - slot) * sizeof(struct btrfs_item));
+
+ /* shift the data */
+ memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+ data_end - total_data, btrfs_leaf_data(leaf) +
+ data_end, old_data - data_end);
+ data_end = old_data;
+ } else {
+ /*
+ * this sucks but it has to be done, if we are inserting at
+ * the end of the leaf only insert 1 of the items, since we
+ * have no way of knowing whats on the next leaf and we'd have
+ * to drop our current locks to figure it out
+ */
+ nr = 1;
+ }
+
+ /* setup the item for the new data */
+ for (i = 0; i < nr; i++) {
+ btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
+ btrfs_set_item_key(leaf, &disk_key, slot + i);
+ item = btrfs_item_nr(leaf, slot + i);
+ btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+ data_end -= data_size[i];
+ btrfs_set_item_size(leaf, item, data_size[i]);
+ }
+ btrfs_set_header_nritems(leaf, nritems + nr);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = 0;
+ if (slot == 0) {
+ btrfs_cpu_key_to_disk(&disk_key, cpu_key);
+ ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+ }
+
+ if (btrfs_leaf_free_space(root, leaf) < 0) {
+ btrfs_print_leaf(root, leaf);
+ BUG();
+ }
+out:
+ if (!ret)
+ ret = nr;
+ return ret;
+}
+
+/*
+ * Given a key and some data, insert items into the tree.
+ * This does all the path init required, making room in the tree if needed.
+ */
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *cpu_key, u32 *data_size,
+ int nr)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ int ret = 0;
+ int slot;
+ int slot_orig;
+ int i;
+ u32 nritems;
+ u32 total_size = 0;
+ u32 total_data = 0;
+ unsigned int data_end;
+ struct btrfs_disk_key disk_key;
+
+ for (i = 0; i < nr; i++) {
+ total_data += data_size[i];
+ }
+
+ total_size = total_data + (nr * sizeof(struct btrfs_item));
+ ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
+ if (ret == 0)
+ return -EEXIST;
+ if (ret < 0)
+ goto out;
+
+ slot_orig = path->slots[0];
+ leaf = path->nodes[0];
+
+ nritems = btrfs_header_nritems(leaf);
+ data_end = leaf_data_end(root, leaf);
+
+ if (btrfs_leaf_free_space(root, leaf) < total_size) {
+ btrfs_print_leaf(root, leaf);
+ printk("not enough freespace need %u have %d\n",
+ total_size, btrfs_leaf_free_space(root, leaf));
+ BUG();
+ }
+
+ slot = path->slots[0];
+ BUG_ON(slot < 0);
+
+ if (slot != nritems) {
+ unsigned int old_data = btrfs_item_end_nr(leaf, slot);
+
+ if (old_data < data_end) {
+ btrfs_print_leaf(root, leaf);
+ printk("slot %d old_data %d data_end %d\n",
+ slot, old_data, data_end);
+ BUG_ON(1);
+ }
+ /*
+ * item0..itemN ... dataN.offset..dataN.size .. data0.size
+ */
+ /* first correct the data pointers */
+ WARN_ON(leaf->map_token);
+ for (i = slot; i < nritems; i++) {
+ u32 ioff;
+
+ item = btrfs_item_nr(leaf, i);
+ if (!leaf->map_token) {
+ map_extent_buffer(leaf, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &leaf->map_token, &leaf->kaddr,
+ &leaf->map_start, &leaf->map_len,
+ KM_USER1);
+ }
+
+ ioff = btrfs_item_offset(leaf, item);
+ btrfs_set_item_offset(leaf, item, ioff - total_data);
+ }
+ if (leaf->map_token) {
+ unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+ leaf->map_token = NULL;
+ }
+
+ /* shift the items */
+ memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
+ btrfs_item_nr_offset(slot),
+ (nritems - slot) * sizeof(struct btrfs_item));
+
+ /* shift the data */
+ memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+ data_end - total_data, btrfs_leaf_data(leaf) +
+ data_end, old_data - data_end);
+ data_end = old_data;
+ }
+
+ /* setup the item for the new data */
+ for (i = 0; i < nr; i++) {
+ btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
+ btrfs_set_item_key(leaf, &disk_key, slot + i);
+ item = btrfs_item_nr(leaf, slot + i);
+ btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+ data_end -= data_size[i];
+ btrfs_set_item_size(leaf, item, data_size[i]);
+ }
+ btrfs_set_header_nritems(leaf, nritems + nr);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = 0;
+ if (slot == 0) {
+ btrfs_cpu_key_to_disk(&disk_key, cpu_key);
+ ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+ }
+
+ if (btrfs_leaf_free_space(root, leaf) < 0) {
+ btrfs_print_leaf(root, leaf);
+ BUG();
+ }
+out:
+ return ret;
+}
+
+/*
+ * Given a key and some data, insert an item into the tree.
+ * This does all the path init required, making room in the tree if needed.
+ */
+int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *cpu_key, void *data, u32
+ data_size)
+{
+ int ret = 0;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ unsigned long ptr;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
+ if (!ret) {
+ leaf = path->nodes[0];
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ write_extent_buffer(leaf, data, ptr, data_size);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * delete the pointer from a given node.
+ *
+ * the tree should have been previously balanced so the deletion does not
+ * empty a node.
+ */
+static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_path *path, int level, int slot)
+{
+ struct extent_buffer *parent = path->nodes[level];
+ u32 nritems;
+ int ret = 0;
+ int wret;
+
+ nritems = btrfs_header_nritems(parent);
+ if (slot != nritems -1) {
+ memmove_extent_buffer(parent,
+ btrfs_node_key_ptr_offset(slot),
+ btrfs_node_key_ptr_offset(slot + 1),
+ sizeof(struct btrfs_key_ptr) *
+ (nritems - slot - 1));
+ }
+ nritems--;
+ btrfs_set_header_nritems(parent, nritems);
+ if (nritems == 0 && parent == root->node) {
+ BUG_ON(btrfs_header_level(root->node) != 1);
+ /* just turn the root into a leaf and break */
+ btrfs_set_header_level(root->node, 0);
+ } else if (slot == 0) {
+ struct btrfs_disk_key disk_key;
+
+ btrfs_node_key(parent, &disk_key, 0);
+ wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
+ if (wret)
+ ret = wret;
+ }
+ btrfs_mark_buffer_dirty(parent);
+ return ret;
+}
+
+/*
+ * a helper function to delete the leaf pointed to by path->slots[1] and
+ * path->nodes[1]. bytenr is the node block pointer, but since the callers
+ * already know it, it is faster to have them pass it down than to
+ * read it out of the node again.
+ *
+ * This deletes the pointer in path->nodes[1] and frees the leaf
+ * block extent. zero is returned if it all worked out, < 0 otherwise.
+ *
+ * The path must have already been setup for deleting the leaf, including
+ * all the proper balancing. path->nodes[1] must be locked.
+ */
+noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 bytenr)
+{
+ int ret;
+ u64 root_gen = btrfs_header_generation(path->nodes[1]);
+
+ ret = del_ptr(trans, root, path, 1, path->slots[1]);
+ if (ret)
+ return ret;
+
+ ret = btrfs_free_extent(trans, root, bytenr,
+ btrfs_level_size(root, 0),
+ path->nodes[1]->start,
+ btrfs_header_owner(path->nodes[1]),
+ root_gen, 0, 1);
+ return ret;
+}
+/*
+ * delete the item at the leaf level in path. If that empties
+ * the leaf, remove it from the tree
+ */
+int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_path *path, int slot, int nr)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ int last_off;
+ int dsize = 0;
+ int ret = 0;
+ int wret;
+ int i;
+ u32 nritems;
+
+ leaf = path->nodes[0];
+ last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
+
+ for (i = 0; i < nr; i++)
+ dsize += btrfs_item_size_nr(leaf, slot + i);
+
+ nritems = btrfs_header_nritems(leaf);
+
+ if (slot + nr != nritems) {
+ int data_end = leaf_data_end(root, leaf);
+
+ memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+ data_end + dsize,
+ btrfs_leaf_data(leaf) + data_end,
+ last_off - data_end);
+
+ for (i = slot + nr; i < nritems; i++) {
+ u32 ioff;
+
+ item = btrfs_item_nr(leaf, i);
+ if (!leaf->map_token) {
+ map_extent_buffer(leaf, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &leaf->map_token, &leaf->kaddr,
+ &leaf->map_start, &leaf->map_len,
+ KM_USER1);
+ }
+ ioff = btrfs_item_offset(leaf, item);
+ btrfs_set_item_offset(leaf, item, ioff + dsize);
+ }
+
+ if (leaf->map_token) {
+ unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+ leaf->map_token = NULL;
+ }
+
+ memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
+ btrfs_item_nr_offset(slot + nr),
+ sizeof(struct btrfs_item) *
+ (nritems - slot - nr));
+ }
+ btrfs_set_header_nritems(leaf, nritems - nr);
+ nritems -= nr;
+
+ /* delete the leaf if we've emptied it */
+ if (nritems == 0) {
+ if (leaf == root->node) {
+ btrfs_set_header_level(leaf, 0);
+ } else {
+ ret = btrfs_del_leaf(trans, root, path, leaf->start);
+ BUG_ON(ret);
+ }
+ } else {
+ int used = leaf_space_used(leaf, 0, nritems);
+ if (slot == 0) {
+ struct btrfs_disk_key disk_key;
+
+ btrfs_item_key(leaf, &disk_key, 0);
+ wret = fixup_low_keys(trans, root, path,
+ &disk_key, 1);
+ if (wret)
+ ret = wret;
+ }
+
+ /* delete the leaf if it is mostly empty */
+ if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
+ /* push_leaf_left fixes the path.
+ * make sure the path still points to our leaf
+ * for possible call to del_ptr below
+ */
+ slot = path->slots[1];
+ extent_buffer_get(leaf);
+
+ wret = push_leaf_left(trans, root, path, 1, 1);
+ if (wret < 0 && wret != -ENOSPC)
+ ret = wret;
+
+ if (path->nodes[0] == leaf &&
+ btrfs_header_nritems(leaf)) {
+ wret = push_leaf_right(trans, root, path, 1, 1);
+ if (wret < 0 && wret != -ENOSPC)
+ ret = wret;
+ }
+
+ if (btrfs_header_nritems(leaf) == 0) {
+ path->slots[1] = slot;
+ ret = btrfs_del_leaf(trans, root, path, leaf->start);
+ BUG_ON(ret);
+ free_extent_buffer(leaf);
+ } else {
+ /* if we're still in the path, make sure
+ * we're dirty. Otherwise, one of the
+ * push_leaf functions must have already
+ * dirtied this buffer
+ */
+ if (path->nodes[0] == leaf)
+ btrfs_mark_buffer_dirty(leaf);
+ free_extent_buffer(leaf);
+ }
+ } else {
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ }
+ return ret;
+}
+
+/*
+ * search the tree again to find a leaf with lesser keys
+ * returns 0 if it found something or 1 if there are no lesser leaves.
+ * returns < 0 on io errors.
+ *
+ * This may release the path, and so you may lose any locks held at the
+ * time you call it.
+ */
+int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
+{
+ struct btrfs_key key;
+ struct btrfs_disk_key found_key;
+ int ret;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
+
+ if (key.offset > 0)
+ key.offset--;
+ else if (key.type > 0)
+ key.type--;
+ else if (key.objectid > 0)
+ key.objectid--;
+ else
+ return 1;
+
+ btrfs_release_path(root, path);
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+ btrfs_item_key(path->nodes[0], &found_key, 0);
+ ret = comp_keys(&found_key, &key);
+ if (ret < 0)
+ return 0;
+ return 1;
+}
+
+/*
+ * A helper function to walk down the tree starting at min_key, and looking
+ * for nodes or leaves that are either in cache or have a minimum
+ * transaction id. This is used by the btree defrag code, and tree logging
+ *
+ * This does not cow, but it does stuff the starting key it finds back
+ * into min_key, so you can call btrfs_search_slot with cow=1 on the
+ * key and get a writable path.
+ *
+ * This does lock as it descends, and path->keep_locks should be set
+ * to 1 by the caller.
+ *
+ * This honors path->lowest_level to prevent descent past a given level
+ * of the tree.
+ *
+ * min_trans indicates the oldest transaction that you are interested
+ * in walking through. Any nodes or leaves older than min_trans are
+ * skipped over (without reading them).
+ *
+ * returns zero if something useful was found, < 0 on error and 1 if there
+ * was nothing in the tree that matched the search criteria.
+ */
+int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
+ struct btrfs_key *max_key,
+ struct btrfs_path *path, int cache_only,
+ u64 min_trans)
+{
+ struct extent_buffer *cur;
+ struct btrfs_key found_key;
+ int slot;
+ int sret;
+ u32 nritems;
+ int level;
+ int ret = 1;
+
+again:
+ cur = btrfs_lock_root_node(root);
+ level = btrfs_header_level(cur);
+ WARN_ON(path->nodes[level]);
+ path->nodes[level] = cur;
+ path->locks[level] = 1;
+
+ if (btrfs_header_generation(cur) < min_trans) {
+ ret = 1;
+ goto out;
+ }
+ while(1) {
+ nritems = btrfs_header_nritems(cur);
+ level = btrfs_header_level(cur);
+ sret = bin_search(cur, min_key, level, &slot);
+
+ /* at the lowest level, we're done, setup the path and exit */
+ if (level == path->lowest_level) {
+ if (slot >= nritems)
+ goto find_next_key;
+ ret = 0;
+ path->slots[level] = slot;
+ btrfs_item_key_to_cpu(cur, &found_key, slot);
+ goto out;
+ }
+ if (sret && slot > 0)
+ slot--;
+ /*
+ * check this node pointer against the cache_only and
+ * min_trans parameters. If it isn't in cache or is too
+ * old, skip to the next one.
+ */
+ while(slot < nritems) {
+ u64 blockptr;
+ u64 gen;
+ struct extent_buffer *tmp;
+ struct btrfs_disk_key disk_key;
+
+ blockptr = btrfs_node_blockptr(cur, slot);
+ gen = btrfs_node_ptr_generation(cur, slot);
+ if (gen < min_trans) {
+ slot++;
+ continue;
+ }
+ if (!cache_only)
+ break;
+
+ if (max_key) {
+ btrfs_node_key(cur, &disk_key, slot);
+ if (comp_keys(&disk_key, max_key) >= 0) {
+ ret = 1;
+ goto out;
+ }
+ }
+
+ tmp = btrfs_find_tree_block(root, blockptr,
+ btrfs_level_size(root, level - 1));
+
+ if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
+ free_extent_buffer(tmp);
+ break;
+ }
+ if (tmp)
+ free_extent_buffer(tmp);
+ slot++;
+ }
+find_next_key:
+ /*
+ * we didn't find a candidate key in this node, walk forward
+ * and find another one
+ */
+ if (slot >= nritems) {
+ path->slots[level] = slot;
+ sret = btrfs_find_next_key(root, path, min_key, level,
+ cache_only, min_trans);
+ if (sret == 0) {
+ btrfs_release_path(root, path);
+ goto again;
+ } else {
+ goto out;
+ }
+ }
+ /* save our key for returning back */
+ btrfs_node_key_to_cpu(cur, &found_key, slot);
+ path->slots[level] = slot;
+ if (level == path->lowest_level) {
+ ret = 0;
+ unlock_up(path, level, 1);
+ goto out;
+ }
+ cur = read_node_slot(root, cur, slot);
+
+ btrfs_tree_lock(cur);
+ path->locks[level - 1] = 1;
+ path->nodes[level - 1] = cur;
+ unlock_up(path, level, 1);
+ }
+out:
+ if (ret == 0)
+ memcpy(min_key, &found_key, sizeof(found_key));
+ return ret;
+}
+
+/*
+ * this is similar to btrfs_next_leaf, but does not try to preserve
+ * and fixup the path. It looks for and returns the next key in the
+ * tree based on the current path and the cache_only and min_trans
+ * parameters.
+ *
+ * 0 is returned if another key is found, < 0 if there are any errors
+ * and 1 is returned if there are no higher keys in the tree
+ *
+ * path->keep_locks should be set to 1 on the search made before
+ * calling this function.
+ */
+int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *key, int lowest_level,
+ int cache_only, u64 min_trans)
+{
+ int level = lowest_level;
+ int slot;
+ struct extent_buffer *c;
+
+ while(level < BTRFS_MAX_LEVEL) {
+ if (!path->nodes[level])
+ return 1;
+
+ slot = path->slots[level] + 1;
+ c = path->nodes[level];
+next:
+ if (slot >= btrfs_header_nritems(c)) {
+ level++;
+ if (level == BTRFS_MAX_LEVEL) {
+ return 1;
+ }
+ continue;
+ }
+ if (level == 0)
+ btrfs_item_key_to_cpu(c, key, slot);
+ else {
+ u64 blockptr = btrfs_node_blockptr(c, slot);
+ u64 gen = btrfs_node_ptr_generation(c, slot);
+
+ if (cache_only) {
+ struct extent_buffer *cur;
+ cur = btrfs_find_tree_block(root, blockptr,
+ btrfs_level_size(root, level - 1));
+ if (!cur || !btrfs_buffer_uptodate(cur, gen)) {
+ slot++;
+ if (cur)
+ free_extent_buffer(cur);
+ goto next;
+ }
+ free_extent_buffer(cur);
+ }
+ if (gen < min_trans) {
+ slot++;
+ goto next;
+ }
+ btrfs_node_key_to_cpu(c, key, slot);
+ }
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * search the tree again to find a leaf with greater keys
+ * returns 0 if it found something or 1 if there are no greater leaves.
+ * returns < 0 on io errors.
+ */
+int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
+{
+ int slot;
+ int level = 1;
+ struct extent_buffer *c;
+ struct extent_buffer *next = NULL;
+ struct btrfs_key key;
+ u32 nritems;
+ int ret;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (nritems == 0) {
+ return 1;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+
+ btrfs_release_path(root, path);
+ path->keep_locks = 1;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ path->keep_locks = 0;
+
+ if (ret < 0)
+ return ret;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ /*
+ * by releasing the path above we dropped all our locks. A balance
+ * could have added more items next to the key that used to be
+ * at the very end of the block. So, check again here and
+ * advance the path if there are now more items available.
+ */
+ if (nritems > 0 && path->slots[0] < nritems - 1) {
+ path->slots[0]++;
+ goto done;
+ }
+
+ while(level < BTRFS_MAX_LEVEL) {
+ if (!path->nodes[level])
+ return 1;
+
+ slot = path->slots[level] + 1;
+ c = path->nodes[level];
+ if (slot >= btrfs_header_nritems(c)) {
+ level++;
+ if (level == BTRFS_MAX_LEVEL) {
+ return 1;
+ }
+ continue;
+ }
+
+ if (next) {
+ btrfs_tree_unlock(next);
+ free_extent_buffer(next);
+ }
+
+ if (level == 1 && (path->locks[1] || path->skip_locking) &&
+ path->reada)
+ reada_for_search(root, path, level, slot, 0);
+
+ next = read_node_slot(root, c, slot);
+ if (!path->skip_locking) {
+ WARN_ON(!btrfs_tree_locked(c));
+ btrfs_tree_lock(next);
+ }
+ break;
+ }
+ path->slots[level] = slot;
+ while(1) {
+ level--;
+ c = path->nodes[level];
+ if (path->locks[level])
+ btrfs_tree_unlock(c);
+ free_extent_buffer(c);
+ path->nodes[level] = next;
+ path->slots[level] = 0;
+ if (!path->skip_locking)
+ path->locks[level] = 1;
+ if (!level)
+ break;
+ if (level == 1 && path->locks[1] && path->reada)
+ reada_for_search(root, path, level, slot, 0);
+ next = read_node_slot(root, next, 0);
+ if (!path->skip_locking) {
+ WARN_ON(!btrfs_tree_locked(path->nodes[level]));
+ btrfs_tree_lock(next);
+ }
+ }
+done:
+ unlock_up(path, 0, 1);
+ return 0;
+}
+
+/*
+ * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
+ * searching until it gets past min_objectid or finds an item of 'type'
+ *
+ * returns 0 if something is found, 1 if nothing was found and < 0 on error
+ */
+int btrfs_previous_item(struct btrfs_root *root,
+ struct btrfs_path *path, u64 min_objectid,
+ int type)
+{
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ u32 nritems;
+ int ret;
+
+ while(1) {
+ if (path->slots[0] == 0) {
+ ret = btrfs_prev_leaf(root, path);
+ if (ret != 0)
+ return ret;
+ } else {
+ path->slots[0]--;
+ }
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (nritems == 0)
+ return 1;
+ if (path->slots[0] == nritems)
+ path->slots[0]--;
+
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.type == type)
+ return 0;
+ if (found_key.objectid < min_objectid)
+ break;
+ if (found_key.objectid == min_objectid &&
+ found_key.type < type)
+ break;
+ }
+ return 1;
+}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
new file mode 100644
index 0000000..0f2a9b5
--- /dev/null
+++ b/fs/btrfs/ctree.h
@@ -0,0 +1,2043 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_CTREE__
+#define __BTRFS_CTREE__
+
+#include <linux/version.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/fs.h>
+#include <linux/completion.h>
+#include <linux/backing-dev.h>
+#include <linux/wait.h>
+#include <asm/kmap_types.h>
+#include "extent_io.h"
+#include "extent_map.h"
+#include "async-thread.h"
+
+struct btrfs_trans_handle;
+struct btrfs_transaction;
+extern struct kmem_cache *btrfs_trans_handle_cachep;
+extern struct kmem_cache *btrfs_transaction_cachep;
+extern struct kmem_cache *btrfs_bit_radix_cachep;
+extern struct kmem_cache *btrfs_path_cachep;
+struct btrfs_ordered_sum;
+
+#define BTRFS_MAGIC "_BFRfS_M"
+
+#define BTRFS_ACL_NOT_CACHED ((void *)-1)
+
+#ifdef CONFIG_LOCKDEP
+# define BTRFS_MAX_LEVEL 7
+#else
+# define BTRFS_MAX_LEVEL 8
+#endif
+
+/* holds pointers to all of the tree roots */
+#define BTRFS_ROOT_TREE_OBJECTID 1ULL
+
+/* stores information about which extents are in use, and reference counts */
+#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
+
+/*
+ * chunk tree stores translations from logical -> physical block numbering
+ * the super block points to the chunk tree
+ */
+#define BTRFS_CHUNK_TREE_OBJECTID 3ULL
+
+/*
+ * stores information about which areas of a given device are in use.
+ * one per device. The tree of tree roots points to the device tree
+ */
+#define BTRFS_DEV_TREE_OBJECTID 4ULL
+
+/* one per subvolume, storing files and directories */
+#define BTRFS_FS_TREE_OBJECTID 5ULL
+
+/* directory objectid inside the root tree */
+#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
+
+/* orhpan objectid for tracking unlinked/truncated files */
+#define BTRFS_ORPHAN_OBJECTID -5ULL
+
+/* does write ahead logging to speed up fsyncs */
+#define BTRFS_TREE_LOG_OBJECTID -6ULL
+#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
+
+/* for space balancing */
+#define BTRFS_TREE_RELOC_OBJECTID -8ULL
+#define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
+
+/* dummy objectid represents multiple objectids */
+#define BTRFS_MULTIPLE_OBJECTIDS -255ULL
+
+/*
+ * All files have objectids in this range.
+ */
+#define BTRFS_FIRST_FREE_OBJECTID 256ULL
+#define BTRFS_LAST_FREE_OBJECTID -256ULL
+#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
+
+
+/*
+ * the device items go into the chunk tree. The key is in the form
+ * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
+ */
+#define BTRFS_DEV_ITEMS_OBJECTID 1ULL
+
+/*
+ * we can actually store much bigger names, but lets not confuse the rest
+ * of linux
+ */
+#define BTRFS_NAME_LEN 255
+
+/* 32 bytes in various csum fields */
+#define BTRFS_CSUM_SIZE 32
+/* four bytes for CRC32 */
+#define BTRFS_CRC32_SIZE 4
+#define BTRFS_EMPTY_DIR_SIZE 0
+
+#define BTRFS_FT_UNKNOWN 0
+#define BTRFS_FT_REG_FILE 1
+#define BTRFS_FT_DIR 2
+#define BTRFS_FT_CHRDEV 3
+#define BTRFS_FT_BLKDEV 4
+#define BTRFS_FT_FIFO 5
+#define BTRFS_FT_SOCK 6
+#define BTRFS_FT_SYMLINK 7
+#define BTRFS_FT_XATTR 8
+#define BTRFS_FT_MAX 9
+
+/*
+ * the key defines the order in the tree, and so it also defines (optimal)
+ * block layout. objectid corresonds to the inode number. The flags
+ * tells us things about the object, and is a kind of stream selector.
+ * so for a given inode, keys with flags of 1 might refer to the inode
+ * data, flags of 2 may point to file data in the btree and flags == 3
+ * may point to extents.
+ *
+ * offset is the starting byte offset for this key in the stream.
+ *
+ * btrfs_disk_key is in disk byte order. struct btrfs_key is always
+ * in cpu native order. Otherwise they are identical and their sizes
+ * should be the same (ie both packed)
+ */
+struct btrfs_disk_key {
+ __le64 objectid;
+ u8 type;
+ __le64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_key {
+ u64 objectid;
+ u8 type;
+ u64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_mapping_tree {
+ struct extent_map_tree map_tree;
+};
+
+#define BTRFS_UUID_SIZE 16
+struct btrfs_dev_item {
+ /* the internal btrfs device id */
+ __le64 devid;
+
+ /* size of the device */
+ __le64 total_bytes;
+
+ /* bytes used */
+ __le64 bytes_used;
+
+ /* optimal io alignment for this device */
+ __le32 io_align;
+
+ /* optimal io width for this device */
+ __le32 io_width;
+
+ /* minimal io size for this device */
+ __le32 sector_size;
+
+ /* type and info about this device */
+ __le64 type;
+
+ /* expected generation for this device */
+ __le64 generation;
+
+ /* grouping information for allocation decisions */
+ __le32 dev_group;
+
+ /* seek speed 0-100 where 100 is fastest */
+ u8 seek_speed;
+
+ /* bandwidth 0-100 where 100 is fastest */
+ u8 bandwidth;
+
+ /* btrfs generated uuid for this device */
+ u8 uuid[BTRFS_UUID_SIZE];
+
+ /* uuid of FS who owns this device */
+ u8 fsid[BTRFS_UUID_SIZE];
+} __attribute__ ((__packed__));
+
+struct btrfs_stripe {
+ __le64 devid;
+ __le64 offset;
+ u8 dev_uuid[BTRFS_UUID_SIZE];
+} __attribute__ ((__packed__));
+
+struct btrfs_chunk {
+ /* size of this chunk in bytes */
+ __le64 length;
+
+ /* objectid of the root referencing this chunk */
+ __le64 owner;
+
+ __le64 stripe_len;
+ __le64 type;
+
+ /* optimal io alignment for this chunk */
+ __le32 io_align;
+
+ /* optimal io width for this chunk */
+ __le32 io_width;
+
+ /* minimal io size for this chunk */
+ __le32 sector_size;
+
+ /* 2^16 stripes is quite a lot, a second limit is the size of a single
+ * item in the btree
+ */
+ __le16 num_stripes;
+
+ /* sub stripes only matter for raid10 */
+ __le16 sub_stripes;
+ struct btrfs_stripe stripe;
+ /* additional stripes go here */
+} __attribute__ ((__packed__));
+
+static inline unsigned long btrfs_chunk_item_size(int num_stripes)
+{
+ BUG_ON(num_stripes == 0);
+ return sizeof(struct btrfs_chunk) +
+ sizeof(struct btrfs_stripe) * (num_stripes - 1);
+}
+
+#define BTRFS_FSID_SIZE 16
+#define BTRFS_HEADER_FLAG_WRITTEN (1 << 0)
+
+/*
+ * every tree block (leaf or node) starts with this header.
+ */
+struct btrfs_header {
+ /* these first four must match the super block */
+ u8 csum[BTRFS_CSUM_SIZE];
+ u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+ __le64 bytenr; /* which block this node is supposed to live in */
+ __le64 flags;
+
+ /* allowed to be different from the super from here on down */
+ u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
+ __le64 generation;
+ __le64 owner;
+ __le32 nritems;
+ u8 level;
+} __attribute__ ((__packed__));
+
+#define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->nodesize - \
+ sizeof(struct btrfs_header)) / \
+ sizeof(struct btrfs_key_ptr))
+#define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
+#define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->leafsize))
+#define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
+ sizeof(struct btrfs_item) - \
+ sizeof(struct btrfs_file_extent_item))
+
+#define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32)
+
+/*
+ * this is a very generous portion of the super block, giving us
+ * room to translate 14 chunks with 3 stripes each.
+ */
+#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
+#define BTRFS_LABEL_SIZE 256
+
+/*
+ * the super block basically lists the main trees of the FS
+ * it currently lacks any block count etc etc
+ */
+struct btrfs_super_block {
+ u8 csum[BTRFS_CSUM_SIZE];
+ /* the first 4 fields must match struct btrfs_header */
+ u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+ __le64 bytenr; /* this block number */
+ __le64 flags;
+
+ /* allowed to be different from the btrfs_header from here own down */
+ __le64 magic;
+ __le64 generation;
+ __le64 root;
+ __le64 chunk_root;
+ __le64 log_root;
+ __le64 total_bytes;
+ __le64 bytes_used;
+ __le64 root_dir_objectid;
+ __le64 num_devices;
+ __le32 sectorsize;
+ __le32 nodesize;
+ __le32 leafsize;
+ __le32 stripesize;
+ __le32 sys_chunk_array_size;
+ __le64 chunk_root_generation;
+ u8 root_level;
+ u8 chunk_root_level;
+ u8 log_root_level;
+ struct btrfs_dev_item dev_item;
+ char label[BTRFS_LABEL_SIZE];
+ u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
+} __attribute__ ((__packed__));
+
+/*
+ * A leaf is full of items. offset and size tell us where to find
+ * the item in the leaf (relative to the start of the data area)
+ */
+struct btrfs_item {
+ struct btrfs_disk_key key;
+ __le32 offset;
+ __le32 size;
+} __attribute__ ((__packed__));
+
+/*
+ * leaves have an item area and a data area:
+ * [item0, item1....itemN] [free space] [dataN...data1, data0]
+ *
+ * The data is separate from the items to get the keys closer together
+ * during searches.
+ */
+struct btrfs_leaf {
+ struct btrfs_header header;
+ struct btrfs_item items[];
+} __attribute__ ((__packed__));
+
+/*
+ * all non-leaf blocks are nodes, they hold only keys and pointers to
+ * other blocks
+ */
+struct btrfs_key_ptr {
+ struct btrfs_disk_key key;
+ __le64 blockptr;
+ __le64 generation;
+} __attribute__ ((__packed__));
+
+struct btrfs_node {
+ struct btrfs_header header;
+ struct btrfs_key_ptr ptrs[];
+} __attribute__ ((__packed__));
+
+/*
+ * btrfs_paths remember the path taken from the root down to the leaf.
+ * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
+ * to any other levels that are present.
+ *
+ * The slots array records the index of the item or block pointer
+ * used while walking the tree.
+ */
+struct btrfs_path {
+ struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
+ int slots[BTRFS_MAX_LEVEL];
+ /* if there is real range locking, this locks field will change */
+ int locks[BTRFS_MAX_LEVEL];
+ int reada;
+ /* keep some upper locks as we walk down */
+ int keep_locks;
+ int skip_locking;
+ int lowest_level;
+};
+
+/*
+ * items in the extent btree are used to record the objectid of the
+ * owner of the block and the number of references
+ */
+struct btrfs_extent_item {
+ __le32 refs;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_ref {
+ __le64 root;
+ __le64 generation;
+ __le64 objectid;
+ __le32 num_refs;
+} __attribute__ ((__packed__));
+
+/* dev extents record free space on individual devices. The owner
+ * field points back to the chunk allocation mapping tree that allocated
+ * the extent. The chunk tree uuid field is a way to double check the owner
+ */
+struct btrfs_dev_extent {
+ __le64 chunk_tree;
+ __le64 chunk_objectid;
+ __le64 chunk_offset;
+ __le64 length;
+ u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
+} __attribute__ ((__packed__));
+
+struct btrfs_inode_ref {
+ __le64 index;
+ __le16 name_len;
+ /* name goes here */
+} __attribute__ ((__packed__));
+
+struct btrfs_timespec {
+ __le64 sec;
+ __le32 nsec;
+} __attribute__ ((__packed__));
+
+typedef enum {
+ BTRFS_COMPRESS_NONE = 0,
+ BTRFS_COMPRESS_ZLIB = 1,
+ BTRFS_COMPRESS_LAST = 2,
+} btrfs_compression_type;
+
+/* we don't understand any encryption methods right now */
+typedef enum {
+ BTRFS_ENCRYPTION_NONE = 0,
+ BTRFS_ENCRYPTION_LAST = 1,
+} btrfs_encryption_type;
+
+struct btrfs_inode_item {
+ /* nfs style generation number */
+ __le64 generation;
+ /* transid that last touched this inode */
+ __le64 transid;
+ __le64 size;
+ __le64 nbytes;
+ __le64 block_group;
+ __le32 nlink;
+ __le32 uid;
+ __le32 gid;
+ __le32 mode;
+ __le64 rdev;
+ __le16 flags;
+ __le16 compat_flags;
+
+ struct btrfs_timespec atime;
+ struct btrfs_timespec ctime;
+ struct btrfs_timespec mtime;
+ struct btrfs_timespec otime;
+} __attribute__ ((__packed__));
+
+struct btrfs_dir_log_item {
+ __le64 end;
+} __attribute__ ((__packed__));
+
+struct btrfs_dir_item {
+ struct btrfs_disk_key location;
+ __le64 transid;
+ __le16 data_len;
+ __le16 name_len;
+ u8 type;
+} __attribute__ ((__packed__));
+
+struct btrfs_root_item {
+ struct btrfs_inode_item inode;
+ __le64 generation;
+ __le64 root_dirid;
+ __le64 bytenr;
+ __le64 byte_limit;
+ __le64 bytes_used;
+ __le64 last_snapshot;
+ __le32 flags;
+ __le32 refs;
+ struct btrfs_disk_key drop_progress;
+ u8 drop_level;
+ u8 level;
+} __attribute__ ((__packed__));
+
+/*
+ * this is used for both forward and backward root refs
+ */
+struct btrfs_root_ref {
+ __le64 dirid;
+ __le64 sequence;
+ __le16 name_len;
+} __attribute__ ((__packed__));
+
+#define BTRFS_FILE_EXTENT_INLINE 0
+#define BTRFS_FILE_EXTENT_REG 1
+#define BTRFS_FILE_EXTENT_PREALLOC 2
+
+struct btrfs_file_extent_item {
+ /*
+ * transaction id that created this extent
+ */
+ __le64 generation;
+ /*
+ * max number of bytes to hold this extent in ram
+ * when we split a compressed extent we can't know how big
+ * each of the resulting pieces will be. So, this is
+ * an upper limit on the size of the extent in ram instead of
+ * an exact limit.
+ */
+ __le64 ram_bytes;
+
+ /*
+ * 32 bits for the various ways we might encode the data,
+ * including compression and encryption. If any of these
+ * are set to something a given disk format doesn't understand
+ * it is treated like an incompat flag for reading and writing,
+ * but not for stat.
+ */
+ u8 compression;
+ u8 encryption;
+ __le16 other_encoding; /* spare for later use */
+
+ /* are we inline data or a real extent? */
+ u8 type;
+
+ /*
+ * disk space consumed by the extent, checksum blocks are included
+ * in these numbers
+ */
+ __le64 disk_bytenr;
+ __le64 disk_num_bytes;
+ /*
+ * the logical offset in file blocks (no csums)
+ * this extent record is for. This allows a file extent to point
+ * into the middle of an existing extent on disk, sharing it
+ * between two snapshots (useful if some bytes in the middle of the
+ * extent have changed
+ */
+ __le64 offset;
+ /*
+ * the logical number of file blocks (no csums included). This
+ * always reflects the size uncompressed and without encoding.
+ */
+ __le64 num_bytes;
+
+} __attribute__ ((__packed__));
+
+struct btrfs_csum_item {
+ u8 csum;
+} __attribute__ ((__packed__));
+
+/* different types of block groups (and chunks) */
+#define BTRFS_BLOCK_GROUP_DATA (1 << 0)
+#define BTRFS_BLOCK_GROUP_SYSTEM (1 << 1)
+#define BTRFS_BLOCK_GROUP_METADATA (1 << 2)
+#define BTRFS_BLOCK_GROUP_RAID0 (1 << 3)
+#define BTRFS_BLOCK_GROUP_RAID1 (1 << 4)
+#define BTRFS_BLOCK_GROUP_DUP (1 << 5)
+#define BTRFS_BLOCK_GROUP_RAID10 (1 << 6)
+
+struct btrfs_block_group_item {
+ __le64 used;
+ __le64 chunk_objectid;
+ __le64 flags;
+} __attribute__ ((__packed__));
+
+struct btrfs_space_info {
+ u64 flags;
+ u64 total_bytes;
+ u64 bytes_used;
+ u64 bytes_pinned;
+ u64 bytes_reserved;
+ u64 bytes_readonly;
+ int full;
+ int force_alloc;
+ struct list_head list;
+
+ /* for block groups in our same type */
+ struct list_head block_groups;
+ spinlock_t lock;
+ struct rw_semaphore groups_sem;
+};
+
+struct btrfs_free_space {
+ struct rb_node bytes_index;
+ struct rb_node offset_index;
+ u64 offset;
+ u64 bytes;
+};
+
+struct btrfs_block_group_cache {
+ struct btrfs_key key;
+ struct btrfs_block_group_item item;
+ spinlock_t lock;
+ struct mutex alloc_mutex;
+ u64 pinned;
+ u64 reserved;
+ u64 flags;
+ int cached;
+ int ro;
+ int dirty;
+
+ struct btrfs_space_info *space_info;
+
+ /* free space cache stuff */
+ struct rb_root free_space_bytes;
+ struct rb_root free_space_offset;
+
+ /* block group cache stuff */
+ struct rb_node cache_node;
+
+ /* for block groups in the same raid type */
+ struct list_head list;
+};
+
+struct btrfs_leaf_ref_tree {
+ struct rb_root root;
+ struct list_head list;
+ spinlock_t lock;
+};
+
+struct btrfs_device;
+struct btrfs_fs_devices;
+struct btrfs_fs_info {
+ u8 fsid[BTRFS_FSID_SIZE];
+ u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
+ struct btrfs_root *extent_root;
+ struct btrfs_root *tree_root;
+ struct btrfs_root *chunk_root;
+ struct btrfs_root *dev_root;
+ struct btrfs_root *fs_root;
+
+ /* the log root tree is a directory of all the other log roots */
+ struct btrfs_root *log_root_tree;
+ struct radix_tree_root fs_roots_radix;
+
+ /* block group cache stuff */
+ spinlock_t block_group_cache_lock;
+ struct rb_root block_group_cache_tree;
+
+ struct extent_io_tree pinned_extents;
+ struct extent_io_tree pending_del;
+ struct extent_io_tree extent_ins;
+
+ /* logical->physical extent mapping */
+ struct btrfs_mapping_tree mapping_tree;
+
+ u64 generation;
+ u64 last_trans_committed;
+ u64 last_trans_new_blockgroup;
+ u64 open_ioctl_trans;
+ unsigned long mount_opt;
+ u64 max_extent;
+ u64 max_inline;
+ u64 alloc_start;
+ struct btrfs_transaction *running_transaction;
+ wait_queue_head_t transaction_throttle;
+ wait_queue_head_t transaction_wait;
+
+ wait_queue_head_t async_submit_wait;
+ wait_queue_head_t tree_log_wait;
+
+ struct btrfs_super_block super_copy;
+ struct btrfs_super_block super_for_commit;
+ struct block_device *__bdev;
+ struct super_block *sb;
+ struct inode *btree_inode;
+ struct backing_dev_info bdi;
+ spinlock_t hash_lock;
+ struct mutex trans_mutex;
+ struct mutex tree_log_mutex;
+ struct mutex transaction_kthread_mutex;
+ struct mutex cleaner_mutex;
+ struct mutex extent_ins_mutex;
+ struct mutex pinned_mutex;
+ struct mutex chunk_mutex;
+ struct mutex drop_mutex;
+ struct mutex volume_mutex;
+ struct mutex tree_reloc_mutex;
+ struct list_head trans_list;
+ struct list_head hashers;
+ struct list_head dead_roots;
+
+ atomic_t nr_async_submits;
+ atomic_t async_submit_draining;
+ atomic_t nr_async_bios;
+ atomic_t async_delalloc_pages;
+ atomic_t tree_log_writers;
+ atomic_t tree_log_commit;
+ unsigned long tree_log_batch;
+ u64 tree_log_transid;
+
+ /*
+ * this is used by the balancing code to wait for all the pending
+ * ordered extents
+ */
+ spinlock_t ordered_extent_lock;
+ struct list_head ordered_extents;
+ struct list_head delalloc_inodes;
+
+ /*
+ * there is a pool of worker threads for checksumming during writes
+ * and a pool for checksumming after reads. This is because readers
+ * can run with FS locks held, and the writers may be waiting for
+ * those locks. We don't want ordering in the pending list to cause
+ * deadlocks, and so the two are serviced separately.
+ *
+ * A third pool does submit_bio to avoid deadlocking with the other
+ * two
+ */
+ struct btrfs_workers workers;
+ struct btrfs_workers delalloc_workers;
+ struct btrfs_workers endio_workers;
+ struct btrfs_workers endio_write_workers;
+ struct btrfs_workers submit_workers;
+ /*
+ * fixup workers take dirty pages that didn't properly go through
+ * the cow mechanism and make them safe to write. It happens
+ * for the sys_munmap function call path
+ */
+ struct btrfs_workers fixup_workers;
+ struct task_struct *transaction_kthread;
+ struct task_struct *cleaner_kthread;
+ int thread_pool_size;
+
+ /* tree relocation relocated fields */
+ struct list_head dead_reloc_roots;
+ struct btrfs_leaf_ref_tree reloc_ref_tree;
+ struct btrfs_leaf_ref_tree shared_ref_tree;
+
+ struct kobject super_kobj;
+ struct completion kobj_unregister;
+ int do_barriers;
+ int closing;
+ int log_root_recovering;
+ atomic_t throttles;
+ atomic_t throttle_gen;
+
+ u64 total_pinned;
+ struct list_head dirty_cowonly_roots;
+
+ struct btrfs_fs_devices *fs_devices;
+ struct list_head space_info;
+ spinlock_t delalloc_lock;
+ spinlock_t new_trans_lock;
+ u64 delalloc_bytes;
+ u64 last_alloc;
+ u64 last_data_alloc;
+
+ spinlock_t ref_cache_lock;
+ u64 total_ref_cache_size;
+
+ u64 avail_data_alloc_bits;
+ u64 avail_metadata_alloc_bits;
+ u64 avail_system_alloc_bits;
+ u64 data_alloc_profile;
+ u64 metadata_alloc_profile;
+ u64 system_alloc_profile;
+
+ void *bdev_holder;
+};
+
+/*
+ * in ram representation of the tree. extent_root is used for all allocations
+ * and for the extent tree extent_root root.
+ */
+struct btrfs_dirty_root;
+struct btrfs_root {
+ struct extent_buffer *node;
+
+ /* the node lock is held while changing the node pointer */
+ spinlock_t node_lock;
+
+ struct extent_buffer *commit_root;
+ struct btrfs_leaf_ref_tree *ref_tree;
+ struct btrfs_leaf_ref_tree ref_tree_struct;
+ struct btrfs_dirty_root *dirty_root;
+ struct btrfs_root *log_root;
+ struct btrfs_root *reloc_root;
+
+ struct btrfs_root_item root_item;
+ struct btrfs_key root_key;
+ struct btrfs_fs_info *fs_info;
+ struct extent_io_tree dirty_log_pages;
+
+ struct kobject root_kobj;
+ struct completion kobj_unregister;
+ struct mutex objectid_mutex;
+ struct mutex log_mutex;
+
+ u64 objectid;
+ u64 last_trans;
+
+ /* data allocations are done in sectorsize units */
+ u32 sectorsize;
+
+ /* node allocations are done in nodesize units */
+ u32 nodesize;
+
+ /* leaf allocations are done in leafsize units */
+ u32 leafsize;
+
+ u32 stripesize;
+
+ u32 type;
+ u64 highest_inode;
+ u64 last_inode_alloc;
+ int ref_cows;
+ int track_dirty;
+ u64 defrag_trans_start;
+ struct btrfs_key defrag_progress;
+ struct btrfs_key defrag_max;
+ int defrag_running;
+ int defrag_level;
+ char *name;
+ int in_sysfs;
+
+ /* the dirty list is only used by non-reference counted roots */
+ struct list_head dirty_list;
+
+ spinlock_t list_lock;
+ struct list_head dead_list;
+ struct list_head orphan_list;
+
+ /*
+ * right now this just gets used so that a root has its own devid
+ * for stat. It may be used for more later
+ */
+ struct super_block anon_super;
+};
+
+/*
+
+ * inode items have the data typically returned from stat and store other
+ * info about object characteristics. There is one for every file and dir in
+ * the FS
+ */
+#define BTRFS_INODE_ITEM_KEY 1
+#define BTRFS_INODE_REF_KEY 12
+#define BTRFS_XATTR_ITEM_KEY 24
+#define BTRFS_ORPHAN_ITEM_KEY 48
+/* reserve 2-15 close to the inode for later flexibility */
+
+/*
+ * dir items are the name -> inode pointers in a directory. There is one
+ * for every name in a directory.
+ */
+#define BTRFS_DIR_LOG_ITEM_KEY 60
+#define BTRFS_DIR_LOG_INDEX_KEY 72
+#define BTRFS_DIR_ITEM_KEY 84
+#define BTRFS_DIR_INDEX_KEY 96
+/*
+ * extent data is for file data
+ */
+#define BTRFS_EXTENT_DATA_KEY 108
+/*
+ * csum items have the checksums for data in the extents
+ */
+#define BTRFS_CSUM_ITEM_KEY 120
+
+
+/* reserve 21-31 for other file/dir stuff */
+
+/*
+ * root items point to tree roots. There are typically in the root
+ * tree used by the super block to find all the other trees
+ */
+#define BTRFS_ROOT_ITEM_KEY 132
+
+/*
+ * root backrefs tie subvols and snapshots to the directory entries that
+ * reference them
+ */
+#define BTRFS_ROOT_BACKREF_KEY 144
+
+/*
+ * root refs make a fast index for listing all of the snapshots and
+ * subvolumes referenced by a given root. They point directly to the
+ * directory item in the root that references the subvol
+ */
+#define BTRFS_ROOT_REF_KEY 156
+
+/*
+ * extent items are in the extent map tree. These record which blocks
+ * are used, and how many references there are to each block
+ */
+#define BTRFS_EXTENT_ITEM_KEY 168
+#define BTRFS_EXTENT_REF_KEY 180
+
+/*
+ * block groups give us hints into the extent allocation trees. Which
+ * blocks are free etc etc
+ */
+#define BTRFS_BLOCK_GROUP_ITEM_KEY 192
+
+#define BTRFS_DEV_EXTENT_KEY 204
+#define BTRFS_DEV_ITEM_KEY 216
+#define BTRFS_CHUNK_ITEM_KEY 228
+
+/*
+ * string items are for debugging. They just store a short string of
+ * data in the FS
+ */
+#define BTRFS_STRING_ITEM_KEY 253
+
+#define BTRFS_MOUNT_NODATASUM (1 << 0)
+#define BTRFS_MOUNT_NODATACOW (1 << 1)
+#define BTRFS_MOUNT_NOBARRIER (1 << 2)
+#define BTRFS_MOUNT_SSD (1 << 3)
+#define BTRFS_MOUNT_DEGRADED (1 << 4)
+#define BTRFS_MOUNT_COMPRESS (1 << 5)
+
+#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
+#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
+#define btrfs_test_opt(root, opt) ((root)->fs_info->mount_opt & \
+ BTRFS_MOUNT_##opt)
+/*
+ * Inode flags
+ */
+#define BTRFS_INODE_NODATASUM (1 << 0)
+#define BTRFS_INODE_NODATACOW (1 << 1)
+#define BTRFS_INODE_READONLY (1 << 2)
+#define BTRFS_INODE_NOCOMPRESS (1 << 3)
+#define BTRFS_INODE_PREALLOC (1 << 4)
+#define btrfs_clear_flag(inode, flag) (BTRFS_I(inode)->flags &= \
+ ~BTRFS_INODE_##flag)
+#define btrfs_set_flag(inode, flag) (BTRFS_I(inode)->flags |= \
+ BTRFS_INODE_##flag)
+#define btrfs_test_flag(inode, flag) (BTRFS_I(inode)->flags & \
+ BTRFS_INODE_##flag)
+/* some macros to generate set/get funcs for the struct fields. This
+ * assumes there is a lefoo_to_cpu for every type, so lets make a simple
+ * one for u8:
+ */
+#define le8_to_cpu(v) (v)
+#define cpu_to_le8(v) (v)
+#define __le8 u8
+
+#define read_eb_member(eb, ptr, type, member, result) ( \
+ read_extent_buffer(eb, (char *)(result), \
+ ((unsigned long)(ptr)) + \
+ offsetof(type, member), \
+ sizeof(((type *)0)->member)))
+
+#define write_eb_member(eb, ptr, type, member, result) ( \
+ write_extent_buffer(eb, (char *)(result), \
+ ((unsigned long)(ptr)) + \
+ offsetof(type, member), \
+ sizeof(((type *)0)->member)))
+
+#ifndef BTRFS_SETGET_FUNCS
+#define BTRFS_SETGET_FUNCS(name, type, member, bits) \
+u##bits btrfs_##name(struct extent_buffer *eb, type *s); \
+void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val);
+#endif
+
+#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits) \
+static inline u##bits btrfs_##name(struct extent_buffer *eb) \
+{ \
+ type *p = kmap_atomic(eb->first_page, KM_USER0); \
+ u##bits res = le##bits##_to_cpu(p->member); \
+ kunmap_atomic(p, KM_USER0); \
+ return res; \
+} \
+static inline void btrfs_set_##name(struct extent_buffer *eb, \
+ u##bits val) \
+{ \
+ type *p = kmap_atomic(eb->first_page, KM_USER0); \
+ p->member = cpu_to_le##bits(val); \
+ kunmap_atomic(p, KM_USER0); \
+}
+
+#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits) \
+static inline u##bits btrfs_##name(type *s) \
+{ \
+ return le##bits##_to_cpu(s->member); \
+} \
+static inline void btrfs_set_##name(type *s, u##bits val) \
+{ \
+ s->member = cpu_to_le##bits(val); \
+}
+
+BTRFS_SETGET_FUNCS(device_type, struct btrfs_dev_item, type, 64);
+BTRFS_SETGET_FUNCS(device_total_bytes, struct btrfs_dev_item, total_bytes, 64);
+BTRFS_SETGET_FUNCS(device_bytes_used, struct btrfs_dev_item, bytes_used, 64);
+BTRFS_SETGET_FUNCS(device_io_align, struct btrfs_dev_item, io_align, 32);
+BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32);
+BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32);
+BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64);
+BTRFS_SETGET_FUNCS(device_group, struct btrfs_dev_item, dev_group, 32);
+BTRFS_SETGET_FUNCS(device_seek_speed, struct btrfs_dev_item, seek_speed, 8);
+BTRFS_SETGET_FUNCS(device_bandwidth, struct btrfs_dev_item, bandwidth, 8);
+BTRFS_SETGET_FUNCS(device_generation, struct btrfs_dev_item, generation, 64);
+
+BTRFS_SETGET_STACK_FUNCS(stack_device_type, struct btrfs_dev_item, type, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_device_total_bytes, struct btrfs_dev_item,
+ total_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_device_bytes_used, struct btrfs_dev_item,
+ bytes_used, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_device_io_align, struct btrfs_dev_item,
+ io_align, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_device_io_width, struct btrfs_dev_item,
+ io_width, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_device_sector_size, struct btrfs_dev_item,
+ sector_size, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_device_id, struct btrfs_dev_item, devid, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_device_group, struct btrfs_dev_item,
+ dev_group, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_device_seek_speed, struct btrfs_dev_item,
+ seek_speed, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_device_bandwidth, struct btrfs_dev_item,
+ bandwidth, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_device_generation, struct btrfs_dev_item,
+ generation, 64);
+
+static inline char *btrfs_device_uuid(struct btrfs_dev_item *d)
+{
+ return (char *)d + offsetof(struct btrfs_dev_item, uuid);
+}
+
+static inline char *btrfs_device_fsid(struct btrfs_dev_item *d)
+{
+ return (char *)d + offsetof(struct btrfs_dev_item, fsid);
+}
+
+BTRFS_SETGET_FUNCS(chunk_length, struct btrfs_chunk, length, 64);
+BTRFS_SETGET_FUNCS(chunk_owner, struct btrfs_chunk, owner, 64);
+BTRFS_SETGET_FUNCS(chunk_stripe_len, struct btrfs_chunk, stripe_len, 64);
+BTRFS_SETGET_FUNCS(chunk_io_align, struct btrfs_chunk, io_align, 32);
+BTRFS_SETGET_FUNCS(chunk_io_width, struct btrfs_chunk, io_width, 32);
+BTRFS_SETGET_FUNCS(chunk_sector_size, struct btrfs_chunk, sector_size, 32);
+BTRFS_SETGET_FUNCS(chunk_type, struct btrfs_chunk, type, 64);
+BTRFS_SETGET_FUNCS(chunk_num_stripes, struct btrfs_chunk, num_stripes, 16);
+BTRFS_SETGET_FUNCS(chunk_sub_stripes, struct btrfs_chunk, sub_stripes, 16);
+BTRFS_SETGET_FUNCS(stripe_devid, struct btrfs_stripe, devid, 64);
+BTRFS_SETGET_FUNCS(stripe_offset, struct btrfs_stripe, offset, 64);
+
+static inline char *btrfs_stripe_dev_uuid(struct btrfs_stripe *s)
+{
+ return (char *)s + offsetof(struct btrfs_stripe, dev_uuid);
+}
+
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_length, struct btrfs_chunk, length, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_owner, struct btrfs_chunk, owner, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_stripe_len, struct btrfs_chunk,
+ stripe_len, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_align, struct btrfs_chunk,
+ io_align, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_width, struct btrfs_chunk,
+ io_width, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_sector_size, struct btrfs_chunk,
+ sector_size, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_type, struct btrfs_chunk, type, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_num_stripes, struct btrfs_chunk,
+ num_stripes, 16);
+BTRFS_SETGET_STACK_FUNCS(stack_chunk_sub_stripes, struct btrfs_chunk,
+ sub_stripes, 16);
+BTRFS_SETGET_STACK_FUNCS(stack_stripe_devid, struct btrfs_stripe, devid, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_stripe_offset, struct btrfs_stripe, offset, 64);
+
+static inline struct btrfs_stripe *btrfs_stripe_nr(struct btrfs_chunk *c,
+ int nr)
+{
+ unsigned long offset = (unsigned long)c;
+ offset += offsetof(struct btrfs_chunk, stripe);
+ offset += nr * sizeof(struct btrfs_stripe);
+ return (struct btrfs_stripe *)offset;
+}
+
+static inline char *btrfs_stripe_dev_uuid_nr(struct btrfs_chunk *c, int nr)
+{
+ return btrfs_stripe_dev_uuid(btrfs_stripe_nr(c, nr));
+}
+
+static inline u64 btrfs_stripe_offset_nr(struct extent_buffer *eb,
+ struct btrfs_chunk *c, int nr)
+{
+ return btrfs_stripe_offset(eb, btrfs_stripe_nr(c, nr));
+}
+
+static inline void btrfs_set_stripe_offset_nr(struct extent_buffer *eb,
+ struct btrfs_chunk *c, int nr,
+ u64 val)
+{
+ btrfs_set_stripe_offset(eb, btrfs_stripe_nr(c, nr), val);
+}
+
+static inline u64 btrfs_stripe_devid_nr(struct extent_buffer *eb,
+ struct btrfs_chunk *c, int nr)
+{
+ return btrfs_stripe_devid(eb, btrfs_stripe_nr(c, nr));
+}
+
+static inline void btrfs_set_stripe_devid_nr(struct extent_buffer *eb,
+ struct btrfs_chunk *c, int nr,
+ u64 val)
+{
+ btrfs_set_stripe_devid(eb, btrfs_stripe_nr(c, nr), val);
+}
+
+/* struct btrfs_block_group_item */
+BTRFS_SETGET_STACK_FUNCS(block_group_used, struct btrfs_block_group_item,
+ used, 64);
+BTRFS_SETGET_FUNCS(disk_block_group_used, struct btrfs_block_group_item,
+ used, 64);
+BTRFS_SETGET_STACK_FUNCS(block_group_chunk_objectid,
+ struct btrfs_block_group_item, chunk_objectid, 64);
+
+BTRFS_SETGET_FUNCS(disk_block_group_chunk_objectid,
+ struct btrfs_block_group_item, chunk_objectid, 64);
+BTRFS_SETGET_FUNCS(disk_block_group_flags,
+ struct btrfs_block_group_item, flags, 64);
+BTRFS_SETGET_STACK_FUNCS(block_group_flags,
+ struct btrfs_block_group_item, flags, 64);
+
+/* struct btrfs_inode_ref */
+BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);
+BTRFS_SETGET_FUNCS(inode_ref_index, struct btrfs_inode_ref, index, 64);
+
+/* struct btrfs_inode_item */
+BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
+BTRFS_SETGET_FUNCS(inode_transid, struct btrfs_inode_item, transid, 64);
+BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64);
+BTRFS_SETGET_FUNCS(inode_nbytes, struct btrfs_inode_item, nbytes, 64);
+BTRFS_SETGET_FUNCS(inode_block_group, struct btrfs_inode_item, block_group, 64);
+BTRFS_SETGET_FUNCS(inode_nlink, struct btrfs_inode_item, nlink, 32);
+BTRFS_SETGET_FUNCS(inode_uid, struct btrfs_inode_item, uid, 32);
+BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32);
+BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32);
+BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 64);
+BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 16);
+BTRFS_SETGET_FUNCS(inode_compat_flags, struct btrfs_inode_item,
+ compat_flags, 16);
+
+static inline struct btrfs_timespec *
+btrfs_inode_atime(struct btrfs_inode_item *inode_item)
+{
+ unsigned long ptr = (unsigned long)inode_item;
+ ptr += offsetof(struct btrfs_inode_item, atime);
+ return (struct btrfs_timespec *)ptr;
+}
+
+static inline struct btrfs_timespec *
+btrfs_inode_mtime(struct btrfs_inode_item *inode_item)
+{
+ unsigned long ptr = (unsigned long)inode_item;
+ ptr += offsetof(struct btrfs_inode_item, mtime);
+ return (struct btrfs_timespec *)ptr;
+}
+
+static inline struct btrfs_timespec *
+btrfs_inode_ctime(struct btrfs_inode_item *inode_item)
+{
+ unsigned long ptr = (unsigned long)inode_item;
+ ptr += offsetof(struct btrfs_inode_item, ctime);
+ return (struct btrfs_timespec *)ptr;
+}
+
+static inline struct btrfs_timespec *
+btrfs_inode_otime(struct btrfs_inode_item *inode_item)
+{
+ unsigned long ptr = (unsigned long)inode_item;
+ ptr += offsetof(struct btrfs_inode_item, otime);
+ return (struct btrfs_timespec *)ptr;
+}
+
+BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_timespec, sec, 64);
+BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32);
+
+/* struct btrfs_dev_extent */
+BTRFS_SETGET_FUNCS(dev_extent_chunk_tree, struct btrfs_dev_extent,
+ chunk_tree, 64);
+BTRFS_SETGET_FUNCS(dev_extent_chunk_objectid, struct btrfs_dev_extent,
+ chunk_objectid, 64);
+BTRFS_SETGET_FUNCS(dev_extent_chunk_offset, struct btrfs_dev_extent,
+ chunk_offset, 64);
+BTRFS_SETGET_FUNCS(dev_extent_length, struct btrfs_dev_extent, length, 64);
+
+static inline u8 *btrfs_dev_extent_chunk_tree_uuid(struct btrfs_dev_extent *dev)
+{
+ unsigned long ptr = offsetof(struct btrfs_dev_extent, chunk_tree_uuid);
+ return (u8 *)((unsigned long)dev + ptr);
+}
+
+/* struct btrfs_extent_ref */
+BTRFS_SETGET_FUNCS(ref_root, struct btrfs_extent_ref, root, 64);
+BTRFS_SETGET_FUNCS(ref_generation, struct btrfs_extent_ref, generation, 64);
+BTRFS_SETGET_FUNCS(ref_objectid, struct btrfs_extent_ref, objectid, 64);
+BTRFS_SETGET_FUNCS(ref_num_refs, struct btrfs_extent_ref, num_refs, 32);
+
+BTRFS_SETGET_STACK_FUNCS(stack_ref_root, struct btrfs_extent_ref, root, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_ref_generation, struct btrfs_extent_ref,
+ generation, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_ref_objectid, struct btrfs_extent_ref,
+ objectid, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_ref_num_refs, struct btrfs_extent_ref,
+ num_refs, 32);
+
+/* struct btrfs_extent_item */
+BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 32);
+BTRFS_SETGET_STACK_FUNCS(stack_extent_refs, struct btrfs_extent_item,
+ refs, 32);
+
+/* struct btrfs_node */
+BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64);
+BTRFS_SETGET_FUNCS(key_generation, struct btrfs_key_ptr, generation, 64);
+
+static inline u64 btrfs_node_blockptr(struct extent_buffer *eb, int nr)
+{
+ unsigned long ptr;
+ ptr = offsetof(struct btrfs_node, ptrs) +
+ sizeof(struct btrfs_key_ptr) * nr;
+ return btrfs_key_blockptr(eb, (struct btrfs_key_ptr *)ptr);
+}
+
+static inline void btrfs_set_node_blockptr(struct extent_buffer *eb,
+ int nr, u64 val)
+{
+ unsigned long ptr;
+ ptr = offsetof(struct btrfs_node, ptrs) +
+ sizeof(struct btrfs_key_ptr) * nr;
+ btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);
+}
+
+static inline u64 btrfs_node_ptr_generation(struct extent_buffer *eb, int nr)
+{
+ unsigned long ptr;
+ ptr = offsetof(struct btrfs_node, ptrs) +
+ sizeof(struct btrfs_key_ptr) * nr;
+ return btrfs_key_generation(eb, (struct btrfs_key_ptr *)ptr);
+}
+
+static inline void btrfs_set_node_ptr_generation(struct extent_buffer *eb,
+ int nr, u64 val)
+{
+ unsigned long ptr;
+ ptr = offsetof(struct btrfs_node, ptrs) +
+ sizeof(struct btrfs_key_ptr) * nr;
+ btrfs_set_key_generation(eb, (struct btrfs_key_ptr *)ptr, val);
+}
+
+static inline unsigned long btrfs_node_key_ptr_offset(int nr)
+{
+ return offsetof(struct btrfs_node, ptrs) +
+ sizeof(struct btrfs_key_ptr) * nr;
+}
+
+void btrfs_node_key(struct extent_buffer *eb,
+ struct btrfs_disk_key *disk_key, int nr);
+
+static inline void btrfs_set_node_key(struct extent_buffer *eb,
+ struct btrfs_disk_key *disk_key, int nr)
+{
+ unsigned long ptr;
+ ptr = btrfs_node_key_ptr_offset(nr);
+ write_eb_member(eb, (struct btrfs_key_ptr *)ptr,
+ struct btrfs_key_ptr, key, disk_key);
+}
+
+/* struct btrfs_item */
+BTRFS_SETGET_FUNCS(item_offset, struct btrfs_item, offset, 32);
+BTRFS_SETGET_FUNCS(item_size, struct btrfs_item, size, 32);
+
+static inline unsigned long btrfs_item_nr_offset(int nr)
+{
+ return offsetof(struct btrfs_leaf, items) +
+ sizeof(struct btrfs_item) * nr;
+}
+
+static inline struct btrfs_item *btrfs_item_nr(struct extent_buffer *eb,
+ int nr)
+{
+ return (struct btrfs_item *)btrfs_item_nr_offset(nr);
+}
+
+static inline u32 btrfs_item_end(struct extent_buffer *eb,
+ struct btrfs_item *item)
+{
+ return btrfs_item_offset(eb, item) + btrfs_item_size(eb, item);
+}
+
+static inline u32 btrfs_item_end_nr(struct extent_buffer *eb, int nr)
+{
+ return btrfs_item_end(eb, btrfs_item_nr(eb, nr));
+}
+
+static inline u32 btrfs_item_offset_nr(struct extent_buffer *eb, int nr)
+{
+ return btrfs_item_offset(eb, btrfs_item_nr(eb, nr));
+}
+
+static inline u32 btrfs_item_size_nr(struct extent_buffer *eb, int nr)
+{
+ return btrfs_item_size(eb, btrfs_item_nr(eb, nr));
+}
+
+static inline void btrfs_item_key(struct extent_buffer *eb,
+ struct btrfs_disk_key *disk_key, int nr)
+{
+ struct btrfs_item *item = btrfs_item_nr(eb, nr);
+ read_eb_member(eb, item, struct btrfs_item, key, disk_key);
+}
+
+static inline void btrfs_set_item_key(struct extent_buffer *eb,
+ struct btrfs_disk_key *disk_key, int nr)
+{
+ struct btrfs_item *item = btrfs_item_nr(eb, nr);
+ write_eb_member(eb, item, struct btrfs_item, key, disk_key);
+}
+
+BTRFS_SETGET_FUNCS(dir_log_end, struct btrfs_dir_log_item, end, 64);
+
+/*
+ * struct btrfs_root_ref
+ */
+BTRFS_SETGET_FUNCS(root_ref_dirid, struct btrfs_root_ref, dirid, 64);
+BTRFS_SETGET_FUNCS(root_ref_sequence, struct btrfs_root_ref, sequence, 64);
+BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16);
+
+/* struct btrfs_dir_item */
+BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
+BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
+BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16);
+BTRFS_SETGET_FUNCS(dir_transid, struct btrfs_dir_item, transid, 64);
+
+static inline void btrfs_dir_item_key(struct extent_buffer *eb,
+ struct btrfs_dir_item *item,
+ struct btrfs_disk_key *key)
+{
+ read_eb_member(eb, item, struct btrfs_dir_item, location, key);
+}
+
+static inline void btrfs_set_dir_item_key(struct extent_buffer *eb,
+ struct btrfs_dir_item *item,
+ struct btrfs_disk_key *key)
+{
+ write_eb_member(eb, item, struct btrfs_dir_item, location, key);
+}
+
+/* struct btrfs_disk_key */
+BTRFS_SETGET_STACK_FUNCS(disk_key_objectid, struct btrfs_disk_key,
+ objectid, 64);
+BTRFS_SETGET_STACK_FUNCS(disk_key_offset, struct btrfs_disk_key, offset, 64);
+BTRFS_SETGET_STACK_FUNCS(disk_key_type, struct btrfs_disk_key, type, 8);
+
+static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
+ struct btrfs_disk_key *disk)
+{
+ cpu->offset = le64_to_cpu(disk->offset);
+ cpu->type = disk->type;
+ cpu->objectid = le64_to_cpu(disk->objectid);
+}
+
+static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
+ struct btrfs_key *cpu)
+{
+ disk->offset = cpu_to_le64(cpu->offset);
+ disk->type = cpu->type;
+ disk->objectid = cpu_to_le64(cpu->objectid);
+}
+
+static inline void btrfs_node_key_to_cpu(struct extent_buffer *eb,
+ struct btrfs_key *key, int nr)
+{
+ struct btrfs_disk_key disk_key;
+ btrfs_node_key(eb, &disk_key, nr);
+ btrfs_disk_key_to_cpu(key, &disk_key);
+}
+
+static inline void btrfs_item_key_to_cpu(struct extent_buffer *eb,
+ struct btrfs_key *key, int nr)
+{
+ struct btrfs_disk_key disk_key;
+ btrfs_item_key(eb, &disk_key, nr);
+ btrfs_disk_key_to_cpu(key, &disk_key);
+}
+
+static inline void btrfs_dir_item_key_to_cpu(struct extent_buffer *eb,
+ struct btrfs_dir_item *item,
+ struct btrfs_key *key)
+{
+ struct btrfs_disk_key disk_key;
+ btrfs_dir_item_key(eb, item, &disk_key);
+ btrfs_disk_key_to_cpu(key, &disk_key);
+}
+
+
+static inline u8 btrfs_key_type(struct btrfs_key *key)
+{
+ return key->type;
+}
+
+static inline void btrfs_set_key_type(struct btrfs_key *key, u8 val)
+{
+ key->type = val;
+}
+
+/* struct btrfs_header */
+BTRFS_SETGET_HEADER_FUNCS(header_bytenr, struct btrfs_header, bytenr, 64);
+BTRFS_SETGET_HEADER_FUNCS(header_generation, struct btrfs_header,
+ generation, 64);
+BTRFS_SETGET_HEADER_FUNCS(header_owner, struct btrfs_header, owner, 64);
+BTRFS_SETGET_HEADER_FUNCS(header_nritems, struct btrfs_header, nritems, 32);
+BTRFS_SETGET_HEADER_FUNCS(header_flags, struct btrfs_header, flags, 64);
+BTRFS_SETGET_HEADER_FUNCS(header_level, struct btrfs_header, level, 8);
+
+static inline int btrfs_header_flag(struct extent_buffer *eb, u64 flag)
+{
+ return (btrfs_header_flags(eb) & flag) == flag;
+}
+
+static inline int btrfs_set_header_flag(struct extent_buffer *eb, u64 flag)
+{
+ u64 flags = btrfs_header_flags(eb);
+ btrfs_set_header_flags(eb, flags | flag);
+ return (flags & flag) == flag;
+}
+
+static inline int btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag)
+{
+ u64 flags = btrfs_header_flags(eb);
+ btrfs_set_header_flags(eb, flags & ~flag);
+ return (flags & flag) == flag;
+}
+
+static inline u8 *btrfs_header_fsid(struct extent_buffer *eb)
+{
+ unsigned long ptr = offsetof(struct btrfs_header, fsid);
+ return (u8 *)ptr;
+}
+
+static inline u8 *btrfs_header_chunk_tree_uuid(struct extent_buffer *eb)
+{
+ unsigned long ptr = offsetof(struct btrfs_header, chunk_tree_uuid);
+ return (u8 *)ptr;
+}
+
+static inline u8 *btrfs_super_fsid(struct extent_buffer *eb)
+{
+ unsigned long ptr = offsetof(struct btrfs_super_block, fsid);
+ return (u8 *)ptr;
+}
+
+static inline u8 *btrfs_header_csum(struct extent_buffer *eb)
+{
+ unsigned long ptr = offsetof(struct btrfs_header, csum);
+ return (u8 *)ptr;
+}
+
+static inline struct btrfs_node *btrfs_buffer_node(struct extent_buffer *eb)
+{
+ return NULL;
+}
+
+static inline struct btrfs_leaf *btrfs_buffer_leaf(struct extent_buffer *eb)
+{
+ return NULL;
+}
+
+static inline struct btrfs_header *btrfs_buffer_header(struct extent_buffer *eb)
+{
+ return NULL;
+}
+
+static inline int btrfs_is_leaf(struct extent_buffer *eb)
+{
+ return (btrfs_header_level(eb) == 0);
+}
+
+/* struct btrfs_root_item */
+BTRFS_SETGET_FUNCS(disk_root_generation, struct btrfs_root_item,
+ generation, 64);
+BTRFS_SETGET_FUNCS(disk_root_refs, struct btrfs_root_item, refs, 32);
+BTRFS_SETGET_FUNCS(disk_root_bytenr, struct btrfs_root_item, bytenr, 64);
+BTRFS_SETGET_FUNCS(disk_root_level, struct btrfs_root_item, level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(root_generation, struct btrfs_root_item,
+ generation, 64);
+BTRFS_SETGET_STACK_FUNCS(root_bytenr, struct btrfs_root_item, bytenr, 64);
+BTRFS_SETGET_STACK_FUNCS(root_level, struct btrfs_root_item, level, 8);
+BTRFS_SETGET_STACK_FUNCS(root_dirid, struct btrfs_root_item, root_dirid, 64);
+BTRFS_SETGET_STACK_FUNCS(root_refs, struct btrfs_root_item, refs, 32);
+BTRFS_SETGET_STACK_FUNCS(root_flags, struct btrfs_root_item, flags, 32);
+BTRFS_SETGET_STACK_FUNCS(root_used, struct btrfs_root_item, bytes_used, 64);
+BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);
+BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
+ last_snapshot, 64);
+
+/* struct btrfs_super_block */
+BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
+BTRFS_SETGET_STACK_FUNCS(super_flags, struct btrfs_super_block, flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_generation, struct btrfs_super_block,
+ generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_root, struct btrfs_super_block, root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_sys_array_size,
+ struct btrfs_super_block, sys_chunk_array_size, 32);
+BTRFS_SETGET_STACK_FUNCS(super_chunk_root_generation,
+ struct btrfs_super_block, chunk_root_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_root_level, struct btrfs_super_block,
+ root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(super_chunk_root, struct btrfs_super_block,
+ chunk_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_chunk_root_level, struct btrfs_super_block,
+ chunk_root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(super_log_root, struct btrfs_super_block,
+ log_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_log_root_level, struct btrfs_super_block,
+ log_root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(super_total_bytes, struct btrfs_super_block,
+ total_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(super_bytes_used, struct btrfs_super_block,
+ bytes_used, 64);
+BTRFS_SETGET_STACK_FUNCS(super_sectorsize, struct btrfs_super_block,
+ sectorsize, 32);
+BTRFS_SETGET_STACK_FUNCS(super_nodesize, struct btrfs_super_block,
+ nodesize, 32);
+BTRFS_SETGET_STACK_FUNCS(super_leafsize, struct btrfs_super_block,
+ leafsize, 32);
+BTRFS_SETGET_STACK_FUNCS(super_stripesize, struct btrfs_super_block,
+ stripesize, 32);
+BTRFS_SETGET_STACK_FUNCS(super_root_dir, struct btrfs_super_block,
+ root_dir_objectid, 64);
+BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,
+ num_devices, 64);
+
+static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)
+{
+ return offsetof(struct btrfs_leaf, items);
+}
+
+/* struct btrfs_file_extent_item */
+BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8);
+
+static inline unsigned long btrfs_file_extent_inline_start(struct
+ btrfs_file_extent_item *e)
+{
+ unsigned long offset = (unsigned long)e;
+ offset += offsetof(struct btrfs_file_extent_item, disk_bytenr);
+ return offset;
+}
+
+static inline u32 btrfs_file_extent_calc_inline_size(u32 datasize)
+{
+ return offsetof(struct btrfs_file_extent_item, disk_bytenr) + datasize;
+}
+
+BTRFS_SETGET_FUNCS(file_extent_disk_bytenr, struct btrfs_file_extent_item,
+ disk_bytenr, 64);
+BTRFS_SETGET_FUNCS(file_extent_generation, struct btrfs_file_extent_item,
+ generation, 64);
+BTRFS_SETGET_FUNCS(file_extent_disk_num_bytes, struct btrfs_file_extent_item,
+ disk_num_bytes, 64);
+BTRFS_SETGET_FUNCS(file_extent_offset, struct btrfs_file_extent_item,
+ offset, 64);
+BTRFS_SETGET_FUNCS(file_extent_num_bytes, struct btrfs_file_extent_item,
+ num_bytes, 64);
+BTRFS_SETGET_FUNCS(file_extent_ram_bytes, struct btrfs_file_extent_item,
+ ram_bytes, 64);
+BTRFS_SETGET_FUNCS(file_extent_compression, struct btrfs_file_extent_item,
+ compression, 8);
+BTRFS_SETGET_FUNCS(file_extent_encryption, struct btrfs_file_extent_item,
+ encryption, 8);
+BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item,
+ other_encoding, 16);
+
+/* this returns the number of file bytes represented by the inline item.
+ * If an item is compressed, this is the uncompressed size
+ */
+static inline u32 btrfs_file_extent_inline_len(struct extent_buffer *eb,
+ struct btrfs_file_extent_item *e)
+{
+ return btrfs_file_extent_ram_bytes(eb, e);
+}
+
+/*
+ * this returns the number of bytes used by the item on disk, minus the
+ * size of any extent headers. If a file is compressed on disk, this is
+ * the compressed size
+ */
+static inline u32 btrfs_file_extent_inline_item_len(struct extent_buffer *eb,
+ struct btrfs_item *e)
+{
+ unsigned long offset;
+ offset = offsetof(struct btrfs_file_extent_item, disk_bytenr);
+ return btrfs_item_size(eb, e) - offset;
+}
+
+static inline struct btrfs_root *btrfs_sb(struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+static inline int btrfs_set_root_name(struct btrfs_root *root,
+ const char *name, int len)
+{
+ /* if we already have a name just free it */
+ if (root->name)
+ kfree(root->name);
+
+ root->name = kmalloc(len+1, GFP_KERNEL);
+ if (!root->name)
+ return -ENOMEM;
+
+ memcpy(root->name, name, len);
+ root->name[len] ='\0';
+
+ return 0;
+}
+
+static inline u32 btrfs_level_size(struct btrfs_root *root, int level) {
+ if (level == 0)
+ return root->leafsize;
+ return root->nodesize;
+}
+
+/* helper function to cast into the data area of the leaf. */
+#define btrfs_item_ptr(leaf, slot, type) \
+ ((type *)(btrfs_leaf_data(leaf) + \
+ btrfs_item_offset_nr(leaf, slot)))
+
+#define btrfs_item_ptr_offset(leaf, slot) \
+ ((unsigned long)(btrfs_leaf_data(leaf) + \
+ btrfs_item_offset_nr(leaf, slot)))
+
+static inline struct dentry *fdentry(struct file *file)
+{
+ return file->f_path.dentry;
+}
+
+/* extent-tree.c */
+int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len);
+int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 num_bytes, u32 *refs);
+int btrfs_update_pinned_extents(struct btrfs_root *root,
+ u64 bytenr, u64 num, int pin);
+int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *leaf);
+int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr);
+int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy);
+struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
+ btrfs_fs_info *info,
+ u64 bytenr);
+struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
+ struct btrfs_block_group_cache
+ *hint, u64 search_start,
+ int data, int owner);
+struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u32 blocksize, u64 parent,
+ u64 root_objectid,
+ u64 ref_generation,
+ int level,
+ u64 hint,
+ u64 empty_size);
+struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u32 blocksize);
+int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 num_bytes, u64 parent, u64 min_bytes,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner, u64 empty_size, u64 hint_byte,
+ u64 search_end, struct btrfs_key *ins, u64 data);
+int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner, struct btrfs_key *ins);
+int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner, struct btrfs_key *ins);
+int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 num_bytes, u64 min_alloc_size,
+ u64 empty_size, u64 hint_byte,
+ u64 search_end, struct btrfs_key *ins,
+ u64 data);
+int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *orig_buf, struct extent_buffer *buf,
+ u32 *nr_extents);
+int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *buf, u32 nr_extents);
+int btrfs_update_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *orig_buf,
+ struct extent_buffer *buf, int start_slot, int nr);
+int btrfs_free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner_objectid, int pin);
+int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
+int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_io_tree *unpin);
+int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner_objectid);
+int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 orig_parent, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner_objectid);
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+int btrfs_free_block_groups(struct btrfs_fs_info *info);
+int btrfs_read_block_groups(struct btrfs_root *root);
+int btrfs_make_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytes_used,
+ u64 type, u64 chunk_objectid, u64 chunk_offset,
+ u64 size);
+int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 group_start);
+int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start);
+int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+int btrfs_drop_dead_reloc_roots(struct btrfs_root *root);
+int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *buf, u64 orig_start);
+int btrfs_add_dead_reloc_root(struct btrfs_root *root);
+int btrfs_cleanup_reloc_trees(struct btrfs_root *root);
+u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);
+/* ctree.c */
+int btrfs_previous_item(struct btrfs_root *root,
+ struct btrfs_path *path, u64 min_objectid,
+ int type);
+int btrfs_merge_path(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_key *node_keys,
+ u64 *nodes, int lowest_level);
+int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *new_key);
+struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
+struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root);
+int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *key, int lowest_level,
+ int cache_only, u64 min_trans);
+int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
+ struct btrfs_key *max_key,
+ struct btrfs_path *path, int cache_only,
+ u64 min_trans);
+int btrfs_cow_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *buf,
+ struct extent_buffer *parent, int parent_slot,
+ struct extent_buffer **cow_ret, u64 prealloc_dest);
+int btrfs_copy_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *buf,
+ struct extent_buffer **cow_ret, u64 new_root_objectid);
+int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, u32 data_size);
+int btrfs_truncate_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u32 new_size, int from_end);
+int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *key, struct btrfs_path *p, int
+ ins_len, int cow);
+int btrfs_realloc_node(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *parent,
+ int start_slot, int cache_only, u64 *last_ret,
+ struct btrfs_key *progress);
+void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
+struct btrfs_path *btrfs_alloc_path(void);
+void btrfs_free_path(struct btrfs_path *p);
+void btrfs_init_path(struct btrfs_path *p);
+int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_path *path, int slot, int nr);
+int btrfs_del_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 bytenr);
+static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ return btrfs_del_items(trans, root, path, path->slots[0], 1);
+}
+
+int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *key, void *data, u32 data_size);
+int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *cpu_key, u32 *data_size,
+ int nr);
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *cpu_key, u32 *data_size, int nr);
+
+static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *key,
+ u32 data_size)
+{
+ return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
+}
+
+int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
+int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
+int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);
+int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root);
+int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *node,
+ struct extent_buffer *parent);
+/* root-item.c */
+int btrfs_find_root_ref(struct btrfs_root *tree_root,
+ struct btrfs_path *path,
+ u64 root_id, u64 ref_id);
+int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *tree_root,
+ u64 root_id, u8 type, u64 ref_id,
+ u64 dirid, u64 sequence,
+ const char *name, int name_len);
+int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_key *key);
+int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *key, struct btrfs_root_item
+ *item);
+int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *key, struct btrfs_root_item
+ *item);
+int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct
+ btrfs_root_item *item, struct btrfs_key *key);
+int btrfs_search_root(struct btrfs_root *root, u64 search_start,
+ u64 *found_objectid);
+int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
+ struct btrfs_root *latest_root);
+/* dir-item.c */
+int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, const char *name, int name_len, u64 dir,
+ struct btrfs_key *location, u8 type, u64 index);
+struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 dir,
+ const char *name, int name_len,
+ int mod);
+struct btrfs_dir_item *
+btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 dir,
+ u64 objectid, const char *name, int name_len,
+ int mod);
+struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
+ struct btrfs_path *path,
+ const char *name, int name_len);
+int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_dir_item *di);
+int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, const char *name,
+ u16 name_len, const void *data, u16 data_len,
+ u64 dir);
+struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 dir,
+ const char *name, u16 name_len,
+ int mod);
+
+/* orphan.c */
+int btrfs_insert_orphan_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 offset);
+int btrfs_del_orphan_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 offset);
+
+/* inode-map.c */
+int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
+ struct btrfs_root *fs_root,
+ u64 dirid, u64 *objectid);
+int btrfs_find_highest_inode(struct btrfs_root *fs_root, u64 *objectid);
+
+/* inode-item.c */
+int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, u64 index);
+int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, u64 *index);
+int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid);
+int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path,
+ struct btrfs_key *location, int mod);
+
+/* file-item.c */
+int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
+ struct bio *bio);
+int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 pos,
+ u64 disk_offset, u64 disk_num_bytes,
+ u64 num_bytes, u64 offset, u64 ram_bytes,
+ u8 compression, u8 encryption, u16 other_encoding);
+int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid,
+ u64 bytenr, int mod);
+int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ struct btrfs_ordered_sum *sums);
+int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
+ struct bio *bio);
+int btrfs_csum_file_bytes(struct btrfs_root *root, struct inode *inode,
+ u64 start, unsigned long len);
+struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid, u64 offset,
+ int cow);
+int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ u64 isize);
+/* inode.c */
+
+/* RHEL and EL kernels have a patch that renames PG_checked to FsMisc */
+#if defined(ClearPageFsMisc) && !defined(ClearPageChecked)
+#define ClearPageChecked ClearPageFsMisc
+#define SetPageChecked SetPageFsMisc
+#define PageChecked PageFsMisc
+#endif
+
+struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry);
+int btrfs_set_inode_index(struct inode *dir, u64 *index);
+int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir, struct inode *inode,
+ const char *name, int name_len);
+int btrfs_add_link(struct btrfs_trans_handle *trans,
+ struct inode *parent_inode, struct inode *inode,
+ const char *name, int name_len, int add_backref, u64 index);
+int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode, u64 new_size,
+ u32 min_type);
+
+int btrfs_start_delalloc_inodes(struct btrfs_root *root);
+int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end);
+int btrfs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc);
+int btrfs_create_subvol_root(struct btrfs_root *new_root, struct dentry *dentry,
+ struct btrfs_trans_handle *trans, u64 new_dirid,
+ struct btrfs_block_group_cache *block_group);
+
+int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
+ size_t size, struct bio *bio, unsigned long bio_flags);
+
+unsigned long btrfs_force_ra(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *file,
+ pgoff_t offset, pgoff_t last_index);
+int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
+ int for_del);
+int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page);
+int btrfs_readpage(struct file *file, struct page *page);
+void btrfs_delete_inode(struct inode *inode);
+void btrfs_put_inode(struct inode *inode);
+void btrfs_read_locked_inode(struct inode *inode);
+int btrfs_write_inode(struct inode *inode, int wait);
+void btrfs_dirty_inode(struct inode *inode);
+struct inode *btrfs_alloc_inode(struct super_block *sb);
+void btrfs_destroy_inode(struct inode *inode);
+int btrfs_init_cachep(void);
+void btrfs_destroy_cachep(void);
+long btrfs_ioctl_trans_end(struct file *file);
+struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
+ struct btrfs_root *root, int wait);
+struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
+ struct btrfs_root *root);
+struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
+ struct btrfs_root *root, int *is_new);
+int btrfs_commit_write(struct file *file, struct page *page,
+ unsigned from, unsigned to);
+struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
+ size_t page_offset, u64 start, u64 end,
+ int create);
+int btrfs_update_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode);
+int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);
+int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
+void btrfs_orphan_cleanup(struct btrfs_root *root);
+int btrfs_cont_expand(struct inode *inode, loff_t size);
+
+/* ioctl.c */
+long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+
+/* file.c */
+int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync);
+int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
+ int skip_pinned);
+int btrfs_check_file(struct btrfs_root *root, struct inode *inode);
+extern struct file_operations btrfs_file_operations;
+int btrfs_drop_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ u64 start, u64 end, u64 inline_limit, u64 *hint_block);
+int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode, u64 start, u64 end);
+int btrfs_release_file(struct inode *inode, struct file *file);
+
+/* tree-defrag.c */
+int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, int cache_only);
+
+/* sysfs.c */
+int btrfs_init_sysfs(void);
+void btrfs_exit_sysfs(void);
+int btrfs_sysfs_add_super(struct btrfs_fs_info *fs);
+int btrfs_sysfs_add_root(struct btrfs_root *root);
+void btrfs_sysfs_del_root(struct btrfs_root *root);
+void btrfs_sysfs_del_super(struct btrfs_fs_info *root);
+
+/* xattr.c */
+ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
+
+/* super.c */
+u64 btrfs_parse_size(char *str);
+int btrfs_parse_options(struct btrfs_root *root, char *options);
+int btrfs_sync_fs(struct super_block *sb, int wait);
+
+/* acl.c */
+int btrfs_check_acl(struct inode *inode, int mask);
+int btrfs_init_acl(struct inode *inode, struct inode *dir);
+int btrfs_acl_chmod(struct inode *inode);
+
+/* free-space-cache.c */
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+ u64 bytenr, u64 size);
+int btrfs_add_free_space_lock(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes);
+int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
+ u64 bytenr, u64 size);
+int btrfs_remove_free_space_lock(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes);
+void btrfs_remove_free_space_cache(struct btrfs_block_group_cache
+ *block_group);
+struct btrfs_free_space *btrfs_find_free_space(struct btrfs_block_group_cache
+ *block_group, u64 offset,
+ u64 bytes);
+void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
+ u64 bytes);
+u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group);
+#endif
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
new file mode 100644
index 0000000..5040b71
--- /dev/null
+++ b/fs/btrfs/dir-item.c
@@ -0,0 +1,386 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "hash.h"
+#include "transaction.h"
+
+/*
+ * insert a name into a directory, doing overflow properly if there is a hash
+ * collision. data_size indicates how big the item inserted should be. On
+ * success a struct btrfs_dir_item pointer is returned, otherwise it is
+ * an ERR_PTR.
+ *
+ * The name is not copied into the dir item, you have to do that yourself.
+ */
+static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
+ *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *cpu_key,
+ u32 data_size,
+ const char *name,
+ int name_len)
+{
+ int ret;
+ char *ptr;
+ struct btrfs_item *item;
+ struct extent_buffer *leaf;
+
+ ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
+ if (ret == -EEXIST) {
+ struct btrfs_dir_item *di;
+ di = btrfs_match_dir_item_name(root, path, name, name_len);
+ if (di)
+ return ERR_PTR(-EEXIST);
+ ret = btrfs_extend_item(trans, root, path, data_size);
+ WARN_ON(ret > 0);
+ }
+ if (ret < 0)
+ return ERR_PTR(ret);
+ WARN_ON(ret > 0);
+ leaf = path->nodes[0];
+ item = btrfs_item_nr(leaf, path->slots[0]);
+ ptr = btrfs_item_ptr(leaf, path->slots[0], char);
+ BUG_ON(data_size > btrfs_item_size(leaf, item));
+ ptr += btrfs_item_size(leaf, item) - data_size;
+ return (struct btrfs_dir_item *)ptr;
+}
+
+/*
+ * xattrs work a lot like directories, this inserts an xattr item
+ * into the tree
+ */
+int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, const char *name,
+ u16 name_len, const void *data, u16 data_len,
+ u64 dir)
+{
+ int ret = 0;
+ struct btrfs_path *path;
+ struct btrfs_dir_item *dir_item;
+ unsigned long name_ptr, data_ptr;
+ struct btrfs_key key, location;
+ struct btrfs_disk_key disk_key;
+ struct extent_buffer *leaf;
+ u32 data_size;
+
+ key.objectid = dir;
+ btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+ key.offset = btrfs_name_hash(name, name_len);
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ if (name_len + data_len + sizeof(struct btrfs_dir_item) >
+ BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
+ return -ENOSPC;
+
+ data_size = sizeof(*dir_item) + name_len + data_len;
+ dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+ name, name_len);
+ /*
+ * FIXME: at some point we should handle xattr's that are larger than
+ * what we can fit in our leaf. We set location to NULL b/c we arent
+ * pointing at anything else, that will change if we store the xattr
+ * data in a separate inode.
+ */
+ BUG_ON(IS_ERR(dir_item));
+ memset(&location, 0, sizeof(location));
+
+ leaf = path->nodes[0];
+ btrfs_cpu_key_to_disk(&disk_key, &location);
+ btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
+ btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
+ btrfs_set_dir_name_len(leaf, dir_item, name_len);
+ btrfs_set_dir_transid(leaf, dir_item, trans->transid);
+ btrfs_set_dir_data_len(leaf, dir_item, data_len);
+ name_ptr = (unsigned long)(dir_item + 1);
+ data_ptr = (unsigned long)((char *)name_ptr + name_len);
+
+ write_extent_buffer(leaf, name, name_ptr, name_len);
+ write_extent_buffer(leaf, data, data_ptr, data_len);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * insert a directory item in the tree, doing all the magic for
+ * both indexes. 'dir' indicates which objectid to insert it into,
+ * 'location' is the key to stuff into the directory item, 'type' is the
+ * type of the inode we're pointing to, and 'index' is the sequence number
+ * to use for the second index (if one is created).
+ */
+int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, const char *name, int name_len, u64 dir,
+ struct btrfs_key *location, u8 type, u64 index)
+{
+ int ret = 0;
+ int ret2 = 0;
+ struct btrfs_path *path;
+ struct btrfs_dir_item *dir_item;
+ struct extent_buffer *leaf;
+ unsigned long name_ptr;
+ struct btrfs_key key;
+ struct btrfs_disk_key disk_key;
+ u32 data_size;
+
+ key.objectid = dir;
+ btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
+ key.offset = btrfs_name_hash(name, name_len);
+ path = btrfs_alloc_path();
+ data_size = sizeof(*dir_item) + name_len;
+ dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+ name, name_len);
+ if (IS_ERR(dir_item)) {
+ ret = PTR_ERR(dir_item);
+ if (ret == -EEXIST)
+ goto second_insert;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ btrfs_cpu_key_to_disk(&disk_key, location);
+ btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
+ btrfs_set_dir_type(leaf, dir_item, type);
+ btrfs_set_dir_data_len(leaf, dir_item, 0);
+ btrfs_set_dir_name_len(leaf, dir_item, name_len);
+ btrfs_set_dir_transid(leaf, dir_item, trans->transid);
+ name_ptr = (unsigned long)(dir_item + 1);
+
+ write_extent_buffer(leaf, name, name_ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+
+second_insert:
+ /* FIXME, use some real flag for selecting the extra index */
+ if (root == root->fs_info->tree_root) {
+ ret = 0;
+ goto out;
+ }
+ btrfs_release_path(root, path);
+
+ btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
+ key.offset = index;
+ dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+ name, name_len);
+ if (IS_ERR(dir_item)) {
+ ret2 = PTR_ERR(dir_item);
+ goto out;
+ }
+ leaf = path->nodes[0];
+ btrfs_cpu_key_to_disk(&disk_key, location);
+ btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
+ btrfs_set_dir_type(leaf, dir_item, type);
+ btrfs_set_dir_data_len(leaf, dir_item, 0);
+ btrfs_set_dir_name_len(leaf, dir_item, name_len);
+ btrfs_set_dir_transid(leaf, dir_item, trans->transid);
+ name_ptr = (unsigned long)(dir_item + 1);
+ write_extent_buffer(leaf, name, name_ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+out:
+ btrfs_free_path(path);
+ if (ret)
+ return ret;
+ if (ret2)
+ return ret2;
+ return 0;
+}
+
+/*
+ * lookup a directory item based on name. 'dir' is the objectid
+ * we're searching in, and 'mod' tells us if you plan on deleting the
+ * item (use mod < 0) or changing the options (use mod > 0)
+ */
+struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 dir,
+ const char *name, int name_len,
+ int mod)
+{
+ int ret;
+ struct btrfs_key key;
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+
+ key.objectid = dir;
+ btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
+
+ key.offset = btrfs_name_hash(name, name_len);
+
+ ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ return NULL;
+ path->slots[0]--;
+ }
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid != dir ||
+ btrfs_key_type(&found_key) != BTRFS_DIR_ITEM_KEY ||
+ found_key.offset != key.offset)
+ return NULL;
+
+ return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
+/*
+ * lookup a directory item based on index. 'dir' is the objectid
+ * we're searching in, and 'mod' tells us if you plan on deleting the
+ * item (use mod < 0) or changing the options (use mod > 0)
+ *
+ * The name is used to make sure the index really points to the name you were
+ * looking for.
+ */
+struct btrfs_dir_item *
+btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 dir,
+ u64 objectid, const char *name, int name_len,
+ int mod)
+{
+ int ret;
+ struct btrfs_key key;
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+
+ key.objectid = dir;
+ btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
+ key.offset = objectid;
+
+ ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return ERR_PTR(-ENOENT);
+ return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
+struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 dir,
+ const char *name, u16 name_len,
+ int mod)
+{
+ int ret;
+ struct btrfs_key key;
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+
+ key.objectid = dir;
+ btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+ key.offset = btrfs_name_hash(name, name_len);
+ ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ return NULL;
+ path->slots[0]--;
+ }
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid != dir ||
+ btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
+ found_key.offset != key.offset)
+ return NULL;
+
+ return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
+/*
+ * helper function to look at the directory item pointed to by 'path'
+ * this walks through all the entries in a dir item and finds one
+ * for a specific name.
+ */
+struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
+ struct btrfs_path *path,
+ const char *name, int name_len)
+{
+ struct btrfs_dir_item *dir_item;
+ unsigned long name_ptr;
+ u32 total_len;
+ u32 cur = 0;
+ u32 this_len;
+ struct extent_buffer *leaf;
+
+ leaf = path->nodes[0];
+ dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
+ total_len = btrfs_item_size_nr(leaf, path->slots[0]);
+ while(cur < total_len) {
+ this_len = sizeof(*dir_item) +
+ btrfs_dir_name_len(leaf, dir_item) +
+ btrfs_dir_data_len(leaf, dir_item);
+ name_ptr = (unsigned long)(dir_item + 1);
+
+ if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
+ memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
+ return dir_item;
+
+ cur += this_len;
+ dir_item = (struct btrfs_dir_item *)((char *)dir_item +
+ this_len);
+ }
+ return NULL;
+}
+
+/*
+ * given a pointer into a directory item, delete it. This
+ * handles items that have more than one entry in them.
+ */
+int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_dir_item *di)
+{
+
+ struct extent_buffer *leaf;
+ u32 sub_item_len;
+ u32 item_len;
+ int ret = 0;
+
+ leaf = path->nodes[0];
+ sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
+ btrfs_dir_data_len(leaf, di);
+ item_len = btrfs_item_size_nr(leaf, path->slots[0]);
+ if (sub_item_len == item_len) {
+ ret = btrfs_del_item(trans, root, path);
+ } else {
+ /* MARKER */
+ unsigned long ptr = (unsigned long)di;
+ unsigned long start;
+
+ start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
+ item_len - (ptr + sub_item_len - start));
+ ret = btrfs_truncate_item(trans, root, path,
+ item_len - sub_item_len, 1);
+ }
+ return 0;
+}
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
new file mode 100644
index 0000000..c8dcb47
--- /dev/null
+++ b/fs/btrfs/disk-io.c
@@ -0,0 +1,2234 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/version.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/scatterlist.h>
+#include <linux/swap.h>
+#include <linux/radix-tree.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h> // for block_sync_page
+#include <linux/workqueue.h>
+#include <linux/kthread.h>
+# include <linux/freezer.h>
+#include "crc32c.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "volumes.h"
+#include "print-tree.h"
+#include "async-thread.h"
+#include "locking.h"
+#include "ref-cache.h"
+#include "tree-log.h"
+
+#if 0
+static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
+{
+ if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
+ printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
+ (unsigned long long)extent_buffer_blocknr(buf),
+ (unsigned long long)btrfs_header_blocknr(buf));
+ return 1;
+ }
+ return 0;
+}
+#endif
+
+static struct extent_io_ops btree_extent_io_ops;
+static void end_workqueue_fn(struct btrfs_work *work);
+
+/*
+ * end_io_wq structs are used to do processing in task context when an IO is
+ * complete. This is used during reads to verify checksums, and it is used
+ * by writes to insert metadata for new file extents after IO is complete.
+ */
+struct end_io_wq {
+ struct bio *bio;
+ bio_end_io_t *end_io;
+ void *private;
+ struct btrfs_fs_info *info;
+ int error;
+ int metadata;
+ struct list_head list;
+ struct btrfs_work work;
+};
+
+/*
+ * async submit bios are used to offload expensive checksumming
+ * onto the worker threads. They checksum file and metadata bios
+ * just before they are sent down the IO stack.
+ */
+struct async_submit_bio {
+ struct inode *inode;
+ struct bio *bio;
+ struct list_head list;
+ extent_submit_bio_hook_t *submit_bio_start;
+ extent_submit_bio_hook_t *submit_bio_done;
+ int rw;
+ int mirror_num;
+ unsigned long bio_flags;
+ struct btrfs_work work;
+};
+
+/*
+ * extents on the btree inode are pretty simple, there's one extent
+ * that covers the entire device
+ */
+struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
+ size_t page_offset, u64 start, u64 len,
+ int create)
+{
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_map *em;
+ int ret;
+
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (em) {
+ em->bdev =
+ BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
+ spin_unlock(&em_tree->lock);
+ goto out;
+ }
+ spin_unlock(&em_tree->lock);
+
+ em = alloc_extent_map(GFP_NOFS);
+ if (!em) {
+ em = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+ em->start = 0;
+ em->len = (u64)-1;
+ em->block_len = (u64)-1;
+ em->block_start = 0;
+ em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
+
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ if (ret == -EEXIST) {
+ u64 failed_start = em->start;
+ u64 failed_len = em->len;
+
+ printk("failed to insert %Lu %Lu -> %Lu into tree\n",
+ em->start, em->len, em->block_start);
+ free_extent_map(em);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (em) {
+ printk("after failing, found %Lu %Lu %Lu\n",
+ em->start, em->len, em->block_start);
+ ret = 0;
+ } else {
+ em = lookup_extent_mapping(em_tree, failed_start,
+ failed_len);
+ if (em) {
+ printk("double failure lookup gives us "
+ "%Lu %Lu -> %Lu\n", em->start,
+ em->len, em->block_start);
+ free_extent_map(em);
+ }
+ ret = -EIO;
+ }
+ } else if (ret) {
+ free_extent_map(em);
+ em = NULL;
+ }
+ spin_unlock(&em_tree->lock);
+
+ if (ret)
+ em = ERR_PTR(ret);
+out:
+ return em;
+}
+
+u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
+{
+ return btrfs_crc32c(seed, data, len);
+}
+
+void btrfs_csum_final(u32 crc, char *result)
+{
+ *(__le32 *)result = ~cpu_to_le32(crc);
+}
+
+/*
+ * compute the csum for a btree block, and either verify it or write it
+ * into the csum field of the block.
+ */
+static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
+ int verify)
+{
+ char result[BTRFS_CRC32_SIZE];
+ unsigned long len;
+ unsigned long cur_len;
+ unsigned long offset = BTRFS_CSUM_SIZE;
+ char *map_token = NULL;
+ char *kaddr;
+ unsigned long map_start;
+ unsigned long map_len;
+ int err;
+ u32 crc = ~(u32)0;
+
+ len = buf->len - offset;
+ while(len > 0) {
+ err = map_private_extent_buffer(buf, offset, 32,
+ &map_token, &kaddr,
+ &map_start, &map_len, KM_USER0);
+ if (err) {
+ printk("failed to map extent buffer! %lu\n",
+ offset);
+ return 1;
+ }
+ cur_len = min(len, map_len - (offset - map_start));
+ crc = btrfs_csum_data(root, kaddr + offset - map_start,
+ crc, cur_len);
+ len -= cur_len;
+ offset += cur_len;
+ unmap_extent_buffer(buf, map_token, KM_USER0);
+ }
+ btrfs_csum_final(crc, result);
+
+ if (verify) {
+ /* FIXME, this is not good */
+ if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
+ u32 val;
+ u32 found = 0;
+ memcpy(&found, result, BTRFS_CRC32_SIZE);
+
+ read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
+ printk("btrfs: %s checksum verify failed on %llu "
+ "wanted %X found %X level %d\n",
+ root->fs_info->sb->s_id,
+ buf->start, val, found, btrfs_header_level(buf));
+ return 1;
+ }
+ } else {
+ write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
+ }
+ return 0;
+}
+
+/*
+ * we can't consider a given block up to date unless the transid of the
+ * block matches the transid in the parent node's pointer. This is how we
+ * detect blocks that either didn't get written at all or got written
+ * in the wrong place.
+ */
+static int verify_parent_transid(struct extent_io_tree *io_tree,
+ struct extent_buffer *eb, u64 parent_transid)
+{
+ int ret;
+
+ if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
+ return 0;
+
+ lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
+ if (extent_buffer_uptodate(io_tree, eb) &&
+ btrfs_header_generation(eb) == parent_transid) {
+ ret = 0;
+ goto out;
+ }
+ printk("parent transid verify failed on %llu wanted %llu found %llu\n",
+ (unsigned long long)eb->start,
+ (unsigned long long)parent_transid,
+ (unsigned long long)btrfs_header_generation(eb));
+ ret = 1;
+ clear_extent_buffer_uptodate(io_tree, eb);
+out:
+ unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
+ GFP_NOFS);
+ return ret;
+}
+
+/*
+ * helper to read a given tree block, doing retries as required when
+ * the checksums don't match and we have alternate mirrors to try.
+ */
+static int btree_read_extent_buffer_pages(struct btrfs_root *root,
+ struct extent_buffer *eb,
+ u64 start, u64 parent_transid)
+{
+ struct extent_io_tree *io_tree;
+ int ret;
+ int num_copies = 0;
+ int mirror_num = 0;
+
+ io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
+ while (1) {
+ ret = read_extent_buffer_pages(io_tree, eb, start, 1,
+ btree_get_extent, mirror_num);
+ if (!ret &&
+ !verify_parent_transid(io_tree, eb, parent_transid))
+ return ret;
+printk("read extent buffer pages failed with ret %d mirror no %d\n", ret, mirror_num);
+ num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
+ eb->start, eb->len);
+ if (num_copies == 1)
+ return ret;
+
+ mirror_num++;
+ if (mirror_num > num_copies)
+ return ret;
+ }
+ return -EIO;
+}
+
+/*
+ * checksum a dirty tree block before IO. This has extra checks to make
+ * sure we only fill in the checksum field in the first page of a multi-page block
+ */
+int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
+{
+ struct extent_io_tree *tree;
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 found_start;
+ int found_level;
+ unsigned long len;
+ struct extent_buffer *eb;
+ int ret;
+
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+
+ if (page->private == EXTENT_PAGE_PRIVATE)
+ goto out;
+ if (!page->private)
+ goto out;
+ len = page->private >> 2;
+ if (len == 0) {
+ WARN_ON(1);
+ }
+ eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
+ ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
+ btrfs_header_generation(eb));
+ BUG_ON(ret);
+ found_start = btrfs_header_bytenr(eb);
+ if (found_start != start) {
+ printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
+ start, found_start, len);
+ WARN_ON(1);
+ goto err;
+ }
+ if (eb->first_page != page) {
+ printk("bad first page %lu %lu\n", eb->first_page->index,
+ page->index);
+ WARN_ON(1);
+ goto err;
+ }
+ if (!PageUptodate(page)) {
+ printk("csum not up to date page %lu\n", page->index);
+ WARN_ON(1);
+ goto err;
+ }
+ found_level = btrfs_header_level(eb);
+
+ csum_tree_block(root, eb, 0);
+err:
+ free_extent_buffer(eb);
+out:
+ return 0;
+}
+
+static int check_tree_block_fsid(struct btrfs_root *root,
+ struct extent_buffer *eb)
+{
+ struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+ u8 fsid[BTRFS_UUID_SIZE];
+ int ret = 1;
+
+ read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
+ BTRFS_FSID_SIZE);
+ while (fs_devices) {
+ if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
+ ret = 0;
+ break;
+ }
+ fs_devices = fs_devices->seed;
+ }
+ return ret;
+}
+
+int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
+ struct extent_state *state)
+{
+ struct extent_io_tree *tree;
+ u64 found_start;
+ int found_level;
+ unsigned long len;
+ struct extent_buffer *eb;
+ struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+ int ret = 0;
+
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ if (page->private == EXTENT_PAGE_PRIVATE)
+ goto out;
+ if (!page->private)
+ goto out;
+ len = page->private >> 2;
+ if (len == 0) {
+ WARN_ON(1);
+ }
+ eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
+
+ found_start = btrfs_header_bytenr(eb);
+ if (found_start != start) {
+ printk("bad tree block start %llu %llu\n",
+ (unsigned long long)found_start,
+ (unsigned long long)eb->start);
+ ret = -EIO;
+ goto err;
+ }
+ if (eb->first_page != page) {
+ printk("bad first page %lu %lu\n", eb->first_page->index,
+ page->index);
+ WARN_ON(1);
+ ret = -EIO;
+ goto err;
+ }
+ if (check_tree_block_fsid(root, eb)) {
+ printk("bad fsid on block %Lu\n", eb->start);
+ ret = -EIO;
+ goto err;
+ }
+ found_level = btrfs_header_level(eb);
+
+ ret = csum_tree_block(root, eb, 1);
+ if (ret)
+ ret = -EIO;
+
+ end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
+ end = eb->start + end - 1;
+err:
+ free_extent_buffer(eb);
+out:
+ return ret;
+}
+
+static void end_workqueue_bio(struct bio *bio, int err)
+{
+ struct end_io_wq *end_io_wq = bio->bi_private;
+ struct btrfs_fs_info *fs_info;
+
+ fs_info = end_io_wq->info;
+ end_io_wq->error = err;
+ end_io_wq->work.func = end_workqueue_fn;
+ end_io_wq->work.flags = 0;
+ if (bio->bi_rw & (1 << BIO_RW))
+ btrfs_queue_worker(&fs_info->endio_write_workers,
+ &end_io_wq->work);
+ else
+ btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
+}
+
+int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
+ int metadata)
+{
+ struct end_io_wq *end_io_wq;
+ end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
+ if (!end_io_wq)
+ return -ENOMEM;
+
+ end_io_wq->private = bio->bi_private;
+ end_io_wq->end_io = bio->bi_end_io;
+ end_io_wq->info = info;
+ end_io_wq->error = 0;
+ end_io_wq->bio = bio;
+ end_io_wq->metadata = metadata;
+
+ bio->bi_private = end_io_wq;
+ bio->bi_end_io = end_workqueue_bio;
+ return 0;
+}
+
+unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
+{
+ unsigned long limit = min_t(unsigned long,
+ info->workers.max_workers,
+ info->fs_devices->open_devices);
+ return 256 * limit;
+}
+
+int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
+{
+ return atomic_read(&info->nr_async_bios) >
+ btrfs_async_submit_limit(info);
+}
+
+static void run_one_async_start(struct btrfs_work *work)
+{
+ struct btrfs_fs_info *fs_info;
+ struct async_submit_bio *async;
+
+ async = container_of(work, struct async_submit_bio, work);
+ fs_info = BTRFS_I(async->inode)->root->fs_info;
+ async->submit_bio_start(async->inode, async->rw, async->bio,
+ async->mirror_num, async->bio_flags);
+}
+
+static void run_one_async_done(struct btrfs_work *work)
+{
+ struct btrfs_fs_info *fs_info;
+ struct async_submit_bio *async;
+ int limit;
+
+ async = container_of(work, struct async_submit_bio, work);
+ fs_info = BTRFS_I(async->inode)->root->fs_info;
+
+ limit = btrfs_async_submit_limit(fs_info);
+ limit = limit * 2 / 3;
+
+ atomic_dec(&fs_info->nr_async_submits);
+
+ if (atomic_read(&fs_info->nr_async_submits) < limit &&
+ waitqueue_active(&fs_info->async_submit_wait))
+ wake_up(&fs_info->async_submit_wait);
+
+ async->submit_bio_done(async->inode, async->rw, async->bio,
+ async->mirror_num, async->bio_flags);
+}
+
+static void run_one_async_free(struct btrfs_work *work)
+{
+ struct async_submit_bio *async;
+
+ async = container_of(work, struct async_submit_bio, work);
+ kfree(async);
+}
+
+int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
+ int rw, struct bio *bio, int mirror_num,
+ unsigned long bio_flags,
+ extent_submit_bio_hook_t *submit_bio_start,
+ extent_submit_bio_hook_t *submit_bio_done)
+{
+ struct async_submit_bio *async;
+
+ async = kmalloc(sizeof(*async), GFP_NOFS);
+ if (!async)
+ return -ENOMEM;
+
+ async->inode = inode;
+ async->rw = rw;
+ async->bio = bio;
+ async->mirror_num = mirror_num;
+ async->submit_bio_start = submit_bio_start;
+ async->submit_bio_done = submit_bio_done;
+
+ async->work.func = run_one_async_start;
+ async->work.ordered_func = run_one_async_done;
+ async->work.ordered_free = run_one_async_free;
+
+ async->work.flags = 0;
+ async->bio_flags = bio_flags;
+
+ atomic_inc(&fs_info->nr_async_submits);
+ btrfs_queue_worker(&fs_info->workers, &async->work);
+#if 0
+ int limit = btrfs_async_submit_limit(fs_info);
+ if (atomic_read(&fs_info->nr_async_submits) > limit) {
+ wait_event_timeout(fs_info->async_submit_wait,
+ (atomic_read(&fs_info->nr_async_submits) < limit),
+ HZ/10);
+
+ wait_event_timeout(fs_info->async_submit_wait,
+ (atomic_read(&fs_info->nr_async_bios) < limit),
+ HZ/10);
+ }
+#endif
+ while(atomic_read(&fs_info->async_submit_draining) &&
+ atomic_read(&fs_info->nr_async_submits)) {
+ wait_event(fs_info->async_submit_wait,
+ (atomic_read(&fs_info->nr_async_submits) == 0));
+ }
+
+ return 0;
+}
+
+static int btree_csum_one_bio(struct bio *bio)
+{
+ struct bio_vec *bvec = bio->bi_io_vec;
+ int bio_index = 0;
+ struct btrfs_root *root;
+
+ WARN_ON(bio->bi_vcnt <= 0);
+ while(bio_index < bio->bi_vcnt) {
+ root = BTRFS_I(bvec->bv_page->mapping->host)->root;
+ csum_dirty_buffer(root, bvec->bv_page);
+ bio_index++;
+ bvec++;
+ }
+ return 0;
+}
+
+static int __btree_submit_bio_start(struct inode *inode, int rw,
+ struct bio *bio, int mirror_num,
+ unsigned long bio_flags)
+{
+ /*
+ * when we're called for a write, we're already in the async
+ * submission context. Just jump into btrfs_map_bio
+ */
+ btree_csum_one_bio(bio);
+ return 0;
+}
+
+static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ /*
+ * when we're called for a write, we're already in the async
+ * submission context. Just jump into btrfs_map_bio
+ */
+ return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
+}
+
+static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ /*
+ * kthread helpers are used to submit writes so that checksumming
+ * can happen in parallel across all CPUs
+ */
+ if (!(rw & (1 << BIO_RW))) {
+ int ret;
+ /*
+ * called for a read, do the setup so that checksum validation
+ * can happen in the async kernel threads
+ */
+ ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
+ bio, 1);
+ BUG_ON(ret);
+
+ return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
+ mirror_num, 0);
+ }
+ return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
+ inode, rw, bio, mirror_num, 0,
+ __btree_submit_bio_start,
+ __btree_submit_bio_done);
+}
+
+static int btree_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+
+ if (current->flags & PF_MEMALLOC) {
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 0;
+ }
+ return extent_write_full_page(tree, page, btree_get_extent, wbc);
+}
+
+static int btree_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ if (wbc->sync_mode == WB_SYNC_NONE) {
+ u64 num_dirty;
+ u64 start = 0;
+ unsigned long thresh = 32 * 1024 * 1024;
+
+ if (wbc->for_kupdate)
+ return 0;
+
+ num_dirty = count_range_bits(tree, &start, (u64)-1,
+ thresh, EXTENT_DIRTY);
+ if (num_dirty < thresh) {
+ return 0;
+ }
+ }
+ return extent_writepages(tree, mapping, btree_get_extent, wbc);
+}
+
+int btree_readpage(struct file *file, struct page *page)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ return extent_read_full_page(tree, page, btree_get_extent);
+}
+
+static int btree_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ struct extent_io_tree *tree;
+ struct extent_map_tree *map;
+ int ret;
+
+ if (PageWriteback(page) || PageDirty(page))
+ return 0;
+
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ map = &BTRFS_I(page->mapping->host)->extent_tree;
+
+ ret = try_release_extent_state(map, tree, page, gfp_flags);
+ if (!ret) {
+ return 0;
+ }
+
+ ret = try_release_extent_buffer(tree, page);
+ if (ret == 1) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+
+ return ret;
+}
+
+static void btree_invalidatepage(struct page *page, unsigned long offset)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ extent_invalidatepage(tree, page, offset);
+ btree_releasepage(page, GFP_NOFS);
+ if (PagePrivate(page)) {
+ printk("warning page private not zero on page %Lu\n",
+ page_offset(page));
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+}
+
+#if 0
+static int btree_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct buffer_head *bh;
+ struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+ struct buffer_head *head;
+ if (!page_has_buffers(page)) {
+ create_empty_buffers(page, root->fs_info->sb->s_blocksize,
+ (1 << BH_Dirty)|(1 << BH_Uptodate));
+ }
+ head = page_buffers(page);
+ bh = head;
+ do {
+ if (buffer_dirty(bh))
+ csum_tree_block(root, bh, 0);
+ bh = bh->b_this_page;
+ } while (bh != head);
+ return block_write_full_page(page, btree_get_block, wbc);
+}
+#endif
+
+static struct address_space_operations btree_aops = {
+ .readpage = btree_readpage,
+ .writepage = btree_writepage,
+ .writepages = btree_writepages,
+ .releasepage = btree_releasepage,
+ .invalidatepage = btree_invalidatepage,
+ .sync_page = block_sync_page,
+};
+
+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+ u64 parent_transid)
+{
+ struct extent_buffer *buf = NULL;
+ struct inode *btree_inode = root->fs_info->btree_inode;
+ int ret = 0;
+
+ buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
+ if (!buf)
+ return 0;
+ read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
+ buf, 0, 0, btree_get_extent, 0);
+ free_extent_buffer(buf);
+ return ret;
+}
+
+struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
+ u64 bytenr, u32 blocksize)
+{
+ struct inode *btree_inode = root->fs_info->btree_inode;
+ struct extent_buffer *eb;
+ eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
+ bytenr, blocksize, GFP_NOFS);
+ return eb;
+}
+
+struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
+ u64 bytenr, u32 blocksize)
+{
+ struct inode *btree_inode = root->fs_info->btree_inode;
+ struct extent_buffer *eb;
+
+ eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
+ bytenr, blocksize, NULL, GFP_NOFS);
+ return eb;
+}
+
+
+int btrfs_write_tree_block(struct extent_buffer *buf)
+{
+ return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
+ buf->start + buf->len - 1, WB_SYNC_ALL);
+}
+
+int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
+{
+ return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
+ buf->start, buf->start + buf->len -1);
+}
+
+struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
+ u32 blocksize, u64 parent_transid)
+{
+ struct extent_buffer *buf = NULL;
+ struct inode *btree_inode = root->fs_info->btree_inode;
+ struct extent_io_tree *io_tree;
+ int ret;
+
+ io_tree = &BTRFS_I(btree_inode)->io_tree;
+
+ buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
+ if (!buf)
+ return NULL;
+
+ ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
+
+ if (ret == 0) {
+ buf->flags |= EXTENT_UPTODATE;
+ } else {
+ WARN_ON(1);
+ }
+ return buf;
+
+}
+
+int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *buf)
+{
+ struct inode *btree_inode = root->fs_info->btree_inode;
+ if (btrfs_header_generation(buf) ==
+ root->fs_info->running_transaction->transid) {
+ WARN_ON(!btrfs_tree_locked(buf));
+ clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
+ buf);
+ }
+ return 0;
+}
+
+static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
+ u32 stripesize, struct btrfs_root *root,
+ struct btrfs_fs_info *fs_info,
+ u64 objectid)
+{
+ root->node = NULL;
+ root->commit_root = NULL;
+ root->ref_tree = NULL;
+ root->sectorsize = sectorsize;
+ root->nodesize = nodesize;
+ root->leafsize = leafsize;
+ root->stripesize = stripesize;
+ root->ref_cows = 0;
+ root->track_dirty = 0;
+
+ root->fs_info = fs_info;
+ root->objectid = objectid;
+ root->last_trans = 0;
+ root->highest_inode = 0;
+ root->last_inode_alloc = 0;
+ root->name = NULL;
+ root->in_sysfs = 0;
+
+ INIT_LIST_HEAD(&root->dirty_list);
+ INIT_LIST_HEAD(&root->orphan_list);
+ INIT_LIST_HEAD(&root->dead_list);
+ spin_lock_init(&root->node_lock);
+ spin_lock_init(&root->list_lock);
+ mutex_init(&root->objectid_mutex);
+ mutex_init(&root->log_mutex);
+ extent_io_tree_init(&root->dirty_log_pages,
+ fs_info->btree_inode->i_mapping, GFP_NOFS);
+
+ btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
+ root->ref_tree = &root->ref_tree_struct;
+
+ memset(&root->root_key, 0, sizeof(root->root_key));
+ memset(&root->root_item, 0, sizeof(root->root_item));
+ memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
+ memset(&root->root_kobj, 0, sizeof(root->root_kobj));
+ root->defrag_trans_start = fs_info->generation;
+ init_completion(&root->kobj_unregister);
+ root->defrag_running = 0;
+ root->defrag_level = 0;
+ root->root_key.objectid = objectid;
+ root->anon_super.s_root = NULL;
+ root->anon_super.s_dev = 0;
+ INIT_LIST_HEAD(&root->anon_super.s_list);
+ INIT_LIST_HEAD(&root->anon_super.s_instances);
+ init_rwsem(&root->anon_super.s_umount);
+
+ return 0;
+}
+
+static int find_and_setup_root(struct btrfs_root *tree_root,
+ struct btrfs_fs_info *fs_info,
+ u64 objectid,
+ struct btrfs_root *root)
+{
+ int ret;
+ u32 blocksize;
+ u64 generation;
+
+ __setup_root(tree_root->nodesize, tree_root->leafsize,
+ tree_root->sectorsize, tree_root->stripesize,
+ root, fs_info, objectid);
+ ret = btrfs_find_last_root(tree_root, objectid,
+ &root->root_item, &root->root_key);
+ BUG_ON(ret);
+
+ generation = btrfs_root_generation(&root->root_item);
+ blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
+ root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
+ blocksize, generation);
+ BUG_ON(!root->node);
+ return 0;
+}
+
+int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct extent_buffer *eb;
+ struct btrfs_root *log_root_tree = fs_info->log_root_tree;
+ u64 start = 0;
+ u64 end = 0;
+ int ret;
+
+ if (!log_root_tree)
+ return 0;
+
+ while(1) {
+ ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
+ 0, &start, &end, EXTENT_DIRTY);
+ if (ret)
+ break;
+
+ clear_extent_dirty(&log_root_tree->dirty_log_pages,
+ start, end, GFP_NOFS);
+ }
+ eb = fs_info->log_root_tree->node;
+
+ WARN_ON(btrfs_header_level(eb) != 0);
+ WARN_ON(btrfs_header_nritems(eb) != 0);
+
+ ret = btrfs_free_reserved_extent(fs_info->tree_root,
+ eb->start, eb->len);
+ BUG_ON(ret);
+
+ free_extent_buffer(eb);
+ kfree(fs_info->log_root_tree);
+ fs_info->log_root_tree = NULL;
+ return 0;
+}
+
+int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+
+ root = kzalloc(sizeof(*root), GFP_NOFS);
+ if (!root)
+ return -ENOMEM;
+
+ __setup_root(tree_root->nodesize, tree_root->leafsize,
+ tree_root->sectorsize, tree_root->stripesize,
+ root, fs_info, BTRFS_TREE_LOG_OBJECTID);
+
+ root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
+ root->root_key.type = BTRFS_ROOT_ITEM_KEY;
+ root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
+ root->ref_cows = 0;
+
+ root->node = btrfs_alloc_free_block(trans, root, root->leafsize,
+ 0, BTRFS_TREE_LOG_OBJECTID,
+ trans->transid, 0, 0, 0);
+
+ btrfs_set_header_nritems(root->node, 0);
+ btrfs_set_header_level(root->node, 0);
+ btrfs_set_header_bytenr(root->node, root->node->start);
+ btrfs_set_header_generation(root->node, trans->transid);
+ btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
+
+ write_extent_buffer(root->node, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(root->node),
+ BTRFS_FSID_SIZE);
+ btrfs_mark_buffer_dirty(root->node);
+ btrfs_tree_unlock(root->node);
+ fs_info->log_root_tree = root;
+ return 0;
+}
+
+struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
+ struct btrfs_key *location)
+{
+ struct btrfs_root *root;
+ struct btrfs_fs_info *fs_info = tree_root->fs_info;
+ struct btrfs_path *path;
+ struct extent_buffer *l;
+ u64 highest_inode;
+ u64 generation;
+ u32 blocksize;
+ int ret = 0;
+
+ root = kzalloc(sizeof(*root), GFP_NOFS);
+ if (!root)
+ return ERR_PTR(-ENOMEM);
+ if (location->offset == (u64)-1) {
+ ret = find_and_setup_root(tree_root, fs_info,
+ location->objectid, root);
+ if (ret) {
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+ goto insert;
+ }
+
+ __setup_root(tree_root->nodesize, tree_root->leafsize,
+ tree_root->sectorsize, tree_root->stripesize,
+ root, fs_info, location->objectid);
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
+ if (ret != 0) {
+ if (ret > 0)
+ ret = -ENOENT;
+ goto out;
+ }
+ l = path->nodes[0];
+ read_extent_buffer(l, &root->root_item,
+ btrfs_item_ptr_offset(l, path->slots[0]),
+ sizeof(root->root_item));
+ memcpy(&root->root_key, location, sizeof(*location));
+ ret = 0;
+out:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ if (ret) {
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+ generation = btrfs_root_generation(&root->root_item);
+ blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
+ root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
+ blocksize, generation);
+ BUG_ON(!root->node);
+insert:
+ if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
+ root->ref_cows = 1;
+ ret = btrfs_find_highest_inode(root, &highest_inode);
+ if (ret == 0) {
+ root->highest_inode = highest_inode;
+ root->last_inode_alloc = highest_inode;
+ }
+ }
+ return root;
+}
+
+struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
+ u64 root_objectid)
+{
+ struct btrfs_root *root;
+
+ if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
+ return fs_info->tree_root;
+ if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
+ return fs_info->extent_root;
+
+ root = radix_tree_lookup(&fs_info->fs_roots_radix,
+ (unsigned long)root_objectid);
+ return root;
+}
+
+struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location)
+{
+ struct btrfs_root *root;
+ int ret;
+
+ if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
+ return fs_info->tree_root;
+ if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
+ return fs_info->extent_root;
+ if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
+ return fs_info->chunk_root;
+ if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
+ return fs_info->dev_root;
+
+ root = radix_tree_lookup(&fs_info->fs_roots_radix,
+ (unsigned long)location->objectid);
+ if (root)
+ return root;
+
+ root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
+ if (IS_ERR(root))
+ return root;
+
+ set_anon_super(&root->anon_super, NULL);
+
+ ret = radix_tree_insert(&fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid,
+ root);
+ if (ret) {
+ free_extent_buffer(root->node);
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+ if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+ ret = btrfs_find_dead_roots(fs_info->tree_root,
+ root->root_key.objectid, root);
+ BUG_ON(ret);
+ btrfs_orphan_cleanup(root);
+ }
+ return root;
+}
+
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location,
+ const char *name, int namelen)
+{
+ struct btrfs_root *root;
+ int ret;
+
+ root = btrfs_read_fs_root_no_name(fs_info, location);
+ if (!root)
+ return NULL;
+
+ if (root->in_sysfs)
+ return root;
+
+ ret = btrfs_set_root_name(root, name, namelen);
+ if (ret) {
+ free_extent_buffer(root->node);
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+#if 0
+ ret = btrfs_sysfs_add_root(root);
+ if (ret) {
+ free_extent_buffer(root->node);
+ kfree(root->name);
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+#endif
+ root->in_sysfs = 1;
+ return root;
+}
+#if 0
+static int add_hasher(struct btrfs_fs_info *info, char *type) {
+ struct btrfs_hasher *hasher;
+
+ hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
+ if (!hasher)
+ return -ENOMEM;
+ hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
+ if (!hasher->hash_tfm) {
+ kfree(hasher);
+ return -EINVAL;
+ }
+ spin_lock(&info->hash_lock);
+ list_add(&hasher->list, &info->hashers);
+ spin_unlock(&info->hash_lock);
+ return 0;
+}
+#endif
+
+static int btrfs_congested_fn(void *congested_data, int bdi_bits)
+{
+ struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
+ int ret = 0;
+ struct list_head *cur;
+ struct btrfs_device *device;
+ struct backing_dev_info *bdi;
+#if 0
+ if ((bdi_bits & (1 << BDI_write_congested)) &&
+ btrfs_congested_async(info, 0))
+ return 1;
+#endif
+ list_for_each(cur, &info->fs_devices->devices) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ if (!device->bdev)
+ continue;
+ bdi = blk_get_backing_dev_info(device->bdev);
+ if (bdi && bdi_congested(bdi, bdi_bits)) {
+ ret = 1;
+ break;
+ }
+ }
+ return ret;
+}
+
+/*
+ * this unplugs every device on the box, and it is only used when page
+ * is null
+ */
+static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
+{
+ struct list_head *cur;
+ struct btrfs_device *device;
+ struct btrfs_fs_info *info;
+
+ info = (struct btrfs_fs_info *)bdi->unplug_io_data;
+ list_for_each(cur, &info->fs_devices->devices) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ bdi = blk_get_backing_dev_info(device->bdev);
+ if (bdi->unplug_io_fn) {
+ bdi->unplug_io_fn(bdi, page);
+ }
+ }
+}
+
+void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
+{
+ struct inode *inode;
+ struct extent_map_tree *em_tree;
+ struct extent_map *em;
+ struct address_space *mapping;
+ u64 offset;
+
+ /* the generic O_DIRECT read code does this */
+ if (1 || !page) {
+ __unplug_io_fn(bdi, page);
+ return;
+ }
+
+ /*
+ * page->mapping may change at any time. Get a consistent copy
+ * and use that for everything below
+ */
+ smp_mb();
+ mapping = page->mapping;
+ if (!mapping)
+ return;
+
+ inode = mapping->host;
+
+ /*
+ * don't do the expensive searching for a small number of
+ * devices
+ */
+ if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
+ __unplug_io_fn(bdi, page);
+ return;
+ }
+
+ offset = page_offset(page);
+
+ em_tree = &BTRFS_I(inode)->extent_tree;
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
+ spin_unlock(&em_tree->lock);
+ if (!em) {
+ __unplug_io_fn(bdi, page);
+ return;
+ }
+
+ if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
+ free_extent_map(em);
+ __unplug_io_fn(bdi, page);
+ return;
+ }
+ offset = offset - em->start;
+ btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
+ em->block_start + offset, page);
+ free_extent_map(em);
+}
+
+static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
+{
+ bdi_init(bdi);
+ bdi->ra_pages = default_backing_dev_info.ra_pages;
+ bdi->state = 0;
+ bdi->capabilities = default_backing_dev_info.capabilities;
+ bdi->unplug_io_fn = btrfs_unplug_io_fn;
+ bdi->unplug_io_data = info;
+ bdi->congested_fn = btrfs_congested_fn;
+ bdi->congested_data = info;
+ return 0;
+}
+
+static int bio_ready_for_csum(struct bio *bio)
+{
+ u64 length = 0;
+ u64 buf_len = 0;
+ u64 start = 0;
+ struct page *page;
+ struct extent_io_tree *io_tree = NULL;
+ struct btrfs_fs_info *info = NULL;
+ struct bio_vec *bvec;
+ int i;
+ int ret;
+
+ bio_for_each_segment(bvec, bio, i) {
+ page = bvec->bv_page;
+ if (page->private == EXTENT_PAGE_PRIVATE) {
+ length += bvec->bv_len;
+ continue;
+ }
+ if (!page->private) {
+ length += bvec->bv_len;
+ continue;
+ }
+ length = bvec->bv_len;
+ buf_len = page->private >> 2;
+ start = page_offset(page) + bvec->bv_offset;
+ io_tree = &BTRFS_I(page->mapping->host)->io_tree;
+ info = BTRFS_I(page->mapping->host)->root->fs_info;
+ }
+ /* are we fully contained in this bio? */
+ if (buf_len <= length)
+ return 1;
+
+ ret = extent_range_uptodate(io_tree, start + length,
+ start + buf_len - 1);
+ if (ret == 1)
+ return ret;
+ return ret;
+}
+
+/*
+ * called by the kthread helper functions to finally call the bio end_io
+ * functions. This is where read checksum verification actually happens
+ */
+static void end_workqueue_fn(struct btrfs_work *work)
+{
+ struct bio *bio;
+ struct end_io_wq *end_io_wq;
+ struct btrfs_fs_info *fs_info;
+ int error;
+
+ end_io_wq = container_of(work, struct end_io_wq, work);
+ bio = end_io_wq->bio;
+ fs_info = end_io_wq->info;
+
+ /* metadata bios are special because the whole tree block must
+ * be checksummed at once. This makes sure the entire block is in
+ * ram and up to date before trying to verify things. For
+ * blocksize <= pagesize, it is basically a noop
+ */
+ if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
+ btrfs_queue_worker(&fs_info->endio_workers,
+ &end_io_wq->work);
+ return;
+ }
+ error = end_io_wq->error;
+ bio->bi_private = end_io_wq->private;
+ bio->bi_end_io = end_io_wq->end_io;
+ kfree(end_io_wq);
+ bio_endio(bio, error);
+}
+
+static int cleaner_kthread(void *arg)
+{
+ struct btrfs_root *root = arg;
+
+ do {
+ smp_mb();
+ if (root->fs_info->closing)
+ break;
+
+ vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
+ mutex_lock(&root->fs_info->cleaner_mutex);
+ btrfs_clean_old_snapshots(root);
+ mutex_unlock(&root->fs_info->cleaner_mutex);
+
+ if (freezing(current)) {
+ refrigerator();
+ } else {
+ smp_mb();
+ if (root->fs_info->closing)
+ break;
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ }
+ } while (!kthread_should_stop());
+ return 0;
+}
+
+static int transaction_kthread(void *arg)
+{
+ struct btrfs_root *root = arg;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_transaction *cur;
+ unsigned long now;
+ unsigned long delay;
+ int ret;
+
+ do {
+ smp_mb();
+ if (root->fs_info->closing)
+ break;
+
+ delay = HZ * 30;
+ vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
+ mutex_lock(&root->fs_info->transaction_kthread_mutex);
+
+ if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
+ printk("btrfs: total reference cache size %Lu\n",
+ root->fs_info->total_ref_cache_size);
+ }
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ cur = root->fs_info->running_transaction;
+ if (!cur) {
+ mutex_unlock(&root->fs_info->trans_mutex);
+ goto sleep;
+ }
+
+ now = get_seconds();
+ if (now < cur->start_time || now - cur->start_time < 30) {
+ mutex_unlock(&root->fs_info->trans_mutex);
+ delay = HZ * 5;
+ goto sleep;
+ }
+ mutex_unlock(&root->fs_info->trans_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_commit_transaction(trans, root);
+sleep:
+ wake_up_process(root->fs_info->cleaner_kthread);
+ mutex_unlock(&root->fs_info->transaction_kthread_mutex);
+
+ if (freezing(current)) {
+ refrigerator();
+ } else {
+ if (root->fs_info->closing)
+ break;
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(delay);
+ __set_current_state(TASK_RUNNING);
+ }
+ } while (!kthread_should_stop());
+ return 0;
+}
+
+struct btrfs_root *open_ctree(struct super_block *sb,
+ struct btrfs_fs_devices *fs_devices,
+ char *options)
+{
+ u32 sectorsize;
+ u32 nodesize;
+ u32 leafsize;
+ u32 blocksize;
+ u32 stripesize;
+ u64 generation;
+ struct btrfs_key location;
+ struct buffer_head *bh;
+ struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
+ GFP_NOFS);
+ struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
+ GFP_NOFS);
+ struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
+ GFP_NOFS);
+ struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
+ GFP_NOFS);
+ struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
+ GFP_NOFS);
+ struct btrfs_root *log_tree_root;
+
+ int ret;
+ int err = -EINVAL;
+
+ struct btrfs_super_block *disk_super;
+
+ if (!extent_root || !tree_root || !fs_info ||
+ !chunk_root || !dev_root) {
+ err = -ENOMEM;
+ goto fail;
+ }
+ INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
+ INIT_LIST_HEAD(&fs_info->trans_list);
+ INIT_LIST_HEAD(&fs_info->dead_roots);
+ INIT_LIST_HEAD(&fs_info->hashers);
+ INIT_LIST_HEAD(&fs_info->delalloc_inodes);
+ spin_lock_init(&fs_info->hash_lock);
+ spin_lock_init(&fs_info->delalloc_lock);
+ spin_lock_init(&fs_info->new_trans_lock);
+ spin_lock_init(&fs_info->ref_cache_lock);
+
+ init_completion(&fs_info->kobj_unregister);
+ fs_info->tree_root = tree_root;
+ fs_info->extent_root = extent_root;
+ fs_info->chunk_root = chunk_root;
+ fs_info->dev_root = dev_root;
+ fs_info->fs_devices = fs_devices;
+ INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
+ INIT_LIST_HEAD(&fs_info->space_info);
+ btrfs_mapping_init(&fs_info->mapping_tree);
+ atomic_set(&fs_info->nr_async_submits, 0);
+ atomic_set(&fs_info->async_delalloc_pages, 0);
+ atomic_set(&fs_info->async_submit_draining, 0);
+ atomic_set(&fs_info->nr_async_bios, 0);
+ atomic_set(&fs_info->throttles, 0);
+ atomic_set(&fs_info->throttle_gen, 0);
+ fs_info->sb = sb;
+ fs_info->max_extent = (u64)-1;
+ fs_info->max_inline = 8192 * 1024;
+ setup_bdi(fs_info, &fs_info->bdi);
+ fs_info->btree_inode = new_inode(sb);
+ fs_info->btree_inode->i_ino = 1;
+ fs_info->btree_inode->i_nlink = 1;
+
+ fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
+
+ INIT_LIST_HEAD(&fs_info->ordered_extents);
+ spin_lock_init(&fs_info->ordered_extent_lock);
+
+ sb->s_blocksize = 4096;
+ sb->s_blocksize_bits = blksize_bits(4096);
+
+ /*
+ * we set the i_size on the btree inode to the max possible int.
+ * the real end of the address space is determined by all of
+ * the devices in the system
+ */
+ fs_info->btree_inode->i_size = OFFSET_MAX;
+ fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
+ fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
+
+ extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
+ fs_info->btree_inode->i_mapping,
+ GFP_NOFS);
+ extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
+ GFP_NOFS);
+
+ BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
+
+ spin_lock_init(&fs_info->block_group_cache_lock);
+ fs_info->block_group_cache_tree.rb_node = NULL;
+
+ extent_io_tree_init(&fs_info->pinned_extents,
+ fs_info->btree_inode->i_mapping, GFP_NOFS);
+ extent_io_tree_init(&fs_info->pending_del,
+ fs_info->btree_inode->i_mapping, GFP_NOFS);
+ extent_io_tree_init(&fs_info->extent_ins,
+ fs_info->btree_inode->i_mapping, GFP_NOFS);
+ fs_info->do_barriers = 1;
+
+ INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
+ btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
+ btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
+
+ BTRFS_I(fs_info->btree_inode)->root = tree_root;
+ memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
+ sizeof(struct btrfs_key));
+ insert_inode_hash(fs_info->btree_inode);
+
+ mutex_init(&fs_info->trans_mutex);
+ mutex_init(&fs_info->tree_log_mutex);
+ mutex_init(&fs_info->drop_mutex);
+ mutex_init(&fs_info->extent_ins_mutex);
+ mutex_init(&fs_info->pinned_mutex);
+ mutex_init(&fs_info->chunk_mutex);
+ mutex_init(&fs_info->transaction_kthread_mutex);
+ mutex_init(&fs_info->cleaner_mutex);
+ mutex_init(&fs_info->volume_mutex);
+ mutex_init(&fs_info->tree_reloc_mutex);
+ init_waitqueue_head(&fs_info->transaction_throttle);
+ init_waitqueue_head(&fs_info->transaction_wait);
+ init_waitqueue_head(&fs_info->async_submit_wait);
+ init_waitqueue_head(&fs_info->tree_log_wait);
+ atomic_set(&fs_info->tree_log_commit, 0);
+ atomic_set(&fs_info->tree_log_writers, 0);
+ fs_info->tree_log_transid = 0;
+
+#if 0
+ ret = add_hasher(fs_info, "crc32c");
+ if (ret) {
+ printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
+ err = -ENOMEM;
+ goto fail_iput;
+ }
+#endif
+ __setup_root(4096, 4096, 4096, 4096, tree_root,
+ fs_info, BTRFS_ROOT_TREE_OBJECTID);
+
+
+ bh = __bread(fs_devices->latest_bdev,
+ BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
+ if (!bh)
+ goto fail_iput;
+
+ memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
+ brelse(bh);
+
+ memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
+
+ disk_super = &fs_info->super_copy;
+ if (!btrfs_super_root(disk_super))
+ goto fail_sb_buffer;
+
+ ret = btrfs_parse_options(tree_root, options);
+ if (ret) {
+ err = ret;
+ goto fail_sb_buffer;
+ }
+
+ /*
+ * we need to start all the end_io workers up front because the
+ * queue work function gets called at interrupt time, and so it
+ * cannot dynamically grow.
+ */
+ btrfs_init_workers(&fs_info->workers, "worker",
+ fs_info->thread_pool_size);
+
+ btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
+ fs_info->thread_pool_size);
+
+ btrfs_init_workers(&fs_info->submit_workers, "submit",
+ min_t(u64, fs_devices->num_devices,
+ fs_info->thread_pool_size));
+
+ /* a higher idle thresh on the submit workers makes it much more
+ * likely that bios will be send down in a sane order to the
+ * devices
+ */
+ fs_info->submit_workers.idle_thresh = 64;
+
+ fs_info->workers.idle_thresh = 16;
+ fs_info->workers.ordered = 1;
+
+ fs_info->delalloc_workers.idle_thresh = 2;
+ fs_info->delalloc_workers.ordered = 1;
+
+ btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
+ btrfs_init_workers(&fs_info->endio_workers, "endio",
+ fs_info->thread_pool_size);
+ btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
+ fs_info->thread_pool_size);
+
+ /*
+ * endios are largely parallel and should have a very
+ * low idle thresh
+ */
+ fs_info->endio_workers.idle_thresh = 4;
+ fs_info->endio_write_workers.idle_thresh = 64;
+
+ btrfs_start_workers(&fs_info->workers, 1);
+ btrfs_start_workers(&fs_info->submit_workers, 1);
+ btrfs_start_workers(&fs_info->delalloc_workers, 1);
+ btrfs_start_workers(&fs_info->fixup_workers, 1);
+ btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
+ btrfs_start_workers(&fs_info->endio_write_workers,
+ fs_info->thread_pool_size);
+
+ fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
+ fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
+ 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
+
+ nodesize = btrfs_super_nodesize(disk_super);
+ leafsize = btrfs_super_leafsize(disk_super);
+ sectorsize = btrfs_super_sectorsize(disk_super);
+ stripesize = btrfs_super_stripesize(disk_super);
+ tree_root->nodesize = nodesize;
+ tree_root->leafsize = leafsize;
+ tree_root->sectorsize = sectorsize;
+ tree_root->stripesize = stripesize;
+
+ sb->s_blocksize = sectorsize;
+ sb->s_blocksize_bits = blksize_bits(sectorsize);
+
+ if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
+ sizeof(disk_super->magic))) {
+ printk("btrfs: valid FS not found on %s\n", sb->s_id);
+ goto fail_sb_buffer;
+ }
+
+ mutex_lock(&fs_info->chunk_mutex);
+ ret = btrfs_read_sys_array(tree_root);
+ mutex_unlock(&fs_info->chunk_mutex);
+ if (ret) {
+ printk("btrfs: failed to read the system array on %s\n",
+ sb->s_id);
+ goto fail_sys_array;
+ }
+
+ blocksize = btrfs_level_size(tree_root,
+ btrfs_super_chunk_root_level(disk_super));
+ generation = btrfs_super_chunk_root_generation(disk_super);
+
+ __setup_root(nodesize, leafsize, sectorsize, stripesize,
+ chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
+
+ chunk_root->node = read_tree_block(chunk_root,
+ btrfs_super_chunk_root(disk_super),
+ blocksize, generation);
+ BUG_ON(!chunk_root->node);
+
+ read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
+ (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
+ BTRFS_UUID_SIZE);
+
+ mutex_lock(&fs_info->chunk_mutex);
+ ret = btrfs_read_chunk_tree(chunk_root);
+ mutex_unlock(&fs_info->chunk_mutex);
+ if (ret) {
+ printk("btrfs: failed to read chunk tree on %s\n", sb->s_id);
+ goto fail_chunk_root;
+ }
+
+ btrfs_close_extra_devices(fs_devices);
+
+ blocksize = btrfs_level_size(tree_root,
+ btrfs_super_root_level(disk_super));
+ generation = btrfs_super_generation(disk_super);
+
+ tree_root->node = read_tree_block(tree_root,
+ btrfs_super_root(disk_super),
+ blocksize, generation);
+ if (!tree_root->node)
+ goto fail_chunk_root;
+
+
+ ret = find_and_setup_root(tree_root, fs_info,
+ BTRFS_EXTENT_TREE_OBJECTID, extent_root);
+ if (ret)
+ goto fail_tree_root;
+ extent_root->track_dirty = 1;
+
+ ret = find_and_setup_root(tree_root, fs_info,
+ BTRFS_DEV_TREE_OBJECTID, dev_root);
+ dev_root->track_dirty = 1;
+
+ if (ret)
+ goto fail_extent_root;
+
+ btrfs_read_block_groups(extent_root);
+
+ fs_info->generation = generation + 1;
+ fs_info->last_trans_committed = generation;
+ fs_info->data_alloc_profile = (u64)-1;
+ fs_info->metadata_alloc_profile = (u64)-1;
+ fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
+ fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
+ "btrfs-cleaner");
+ if (!fs_info->cleaner_kthread)
+ goto fail_extent_root;
+
+ fs_info->transaction_kthread = kthread_run(transaction_kthread,
+ tree_root,
+ "btrfs-transaction");
+ if (!fs_info->transaction_kthread)
+ goto fail_cleaner;
+
+ if (btrfs_super_log_root(disk_super) != 0) {
+ u32 blocksize;
+ u64 bytenr = btrfs_super_log_root(disk_super);
+
+ if (fs_devices->rw_devices == 0) {
+ printk("Btrfs log replay required on RO media\n");
+ err = -EIO;
+ goto fail_trans_kthread;
+ }
+ blocksize =
+ btrfs_level_size(tree_root,
+ btrfs_super_log_root_level(disk_super));
+
+ log_tree_root = kzalloc(sizeof(struct btrfs_root),
+ GFP_NOFS);
+
+ __setup_root(nodesize, leafsize, sectorsize, stripesize,
+ log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
+
+ log_tree_root->node = read_tree_block(tree_root, bytenr,
+ blocksize,
+ generation + 1);
+ ret = btrfs_recover_log_trees(log_tree_root);
+ BUG_ON(ret);
+ }
+
+ if (!(sb->s_flags & MS_RDONLY)) {
+ ret = btrfs_cleanup_reloc_trees(tree_root);
+ BUG_ON(ret);
+ }
+
+ location.objectid = BTRFS_FS_TREE_OBJECTID;
+ location.type = BTRFS_ROOT_ITEM_KEY;
+ location.offset = (u64)-1;
+
+ fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
+ if (!fs_info->fs_root)
+ goto fail_trans_kthread;
+ return tree_root;
+
+fail_trans_kthread:
+ kthread_stop(fs_info->transaction_kthread);
+fail_cleaner:
+ kthread_stop(fs_info->cleaner_kthread);
+
+ /*
+ * make sure we're done with the btree inode before we stop our
+ * kthreads
+ */
+ filemap_write_and_wait(fs_info->btree_inode->i_mapping);
+ invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
+
+fail_extent_root:
+ free_extent_buffer(extent_root->node);
+fail_tree_root:
+ free_extent_buffer(tree_root->node);
+fail_chunk_root:
+ free_extent_buffer(chunk_root->node);
+fail_sys_array:
+ free_extent_buffer(dev_root->node);
+fail_sb_buffer:
+ btrfs_stop_workers(&fs_info->fixup_workers);
+ btrfs_stop_workers(&fs_info->delalloc_workers);
+ btrfs_stop_workers(&fs_info->workers);
+ btrfs_stop_workers(&fs_info->endio_workers);
+ btrfs_stop_workers(&fs_info->endio_write_workers);
+ btrfs_stop_workers(&fs_info->submit_workers);
+fail_iput:
+ invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
+ iput(fs_info->btree_inode);
+fail:
+ btrfs_close_devices(fs_info->fs_devices);
+ btrfs_mapping_tree_free(&fs_info->mapping_tree);
+
+ kfree(extent_root);
+ kfree(tree_root);
+ bdi_destroy(&fs_info->bdi);
+ kfree(fs_info);
+ kfree(chunk_root);
+ kfree(dev_root);
+ return ERR_PTR(err);
+}
+
+static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
+{
+ char b[BDEVNAME_SIZE];
+
+ if (uptodate) {
+ set_buffer_uptodate(bh);
+ } else {
+ if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+ printk(KERN_WARNING "lost page write due to "
+ "I/O error on %s\n",
+ bdevname(bh->b_bdev, b));
+ }
+ /* note, we dont' set_buffer_write_io_error because we have
+ * our own ways of dealing with the IO errors
+ */
+ clear_buffer_uptodate(bh);
+ }
+ unlock_buffer(bh);
+ put_bh(bh);
+}
+
+int write_all_supers(struct btrfs_root *root)
+{
+ struct list_head *cur;
+ struct list_head *head = &root->fs_info->fs_devices->devices;
+ struct btrfs_device *dev;
+ struct btrfs_super_block *sb;
+ struct btrfs_dev_item *dev_item;
+ struct buffer_head *bh;
+ int ret;
+ int do_barriers;
+ int max_errors;
+ int total_errors = 0;
+ u32 crc;
+ u64 flags;
+
+ max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
+ do_barriers = !btrfs_test_opt(root, NOBARRIER);
+
+ sb = &root->fs_info->super_for_commit;
+ dev_item = &sb->dev_item;
+ list_for_each(cur, head) {
+ dev = list_entry(cur, struct btrfs_device, dev_list);
+ if (!dev->bdev) {
+ total_errors++;
+ continue;
+ }
+ if (!dev->in_fs_metadata || !dev->writeable)
+ continue;
+
+ btrfs_set_stack_device_generation(dev_item, 0);
+ btrfs_set_stack_device_type(dev_item, dev->type);
+ btrfs_set_stack_device_id(dev_item, dev->devid);
+ btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
+ btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
+ btrfs_set_stack_device_io_align(dev_item, dev->io_align);
+ btrfs_set_stack_device_io_width(dev_item, dev->io_width);
+ btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
+ memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
+ memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
+ flags = btrfs_super_flags(sb);
+ btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
+
+
+ crc = ~(u32)0;
+ crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
+ BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+ btrfs_csum_final(crc, sb->csum);
+
+ bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
+ BTRFS_SUPER_INFO_SIZE);
+
+ memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
+ dev->pending_io = bh;
+
+ get_bh(bh);
+ set_buffer_uptodate(bh);
+ lock_buffer(bh);
+ bh->b_end_io = btrfs_end_buffer_write_sync;
+
+ if (do_barriers && dev->barriers) {
+ ret = submit_bh(WRITE_BARRIER, bh);
+ if (ret == -EOPNOTSUPP) {
+ printk("btrfs: disabling barriers on dev %s\n",
+ dev->name);
+ set_buffer_uptodate(bh);
+ dev->barriers = 0;
+ get_bh(bh);
+ lock_buffer(bh);
+ ret = submit_bh(WRITE, bh);
+ }
+ } else {
+ ret = submit_bh(WRITE, bh);
+ }
+ if (ret)
+ total_errors++;
+ }
+ if (total_errors > max_errors) {
+ printk("btrfs: %d errors while writing supers\n", total_errors);
+ BUG();
+ }
+ total_errors = 0;
+
+ list_for_each(cur, head) {
+ dev = list_entry(cur, struct btrfs_device, dev_list);
+ if (!dev->bdev)
+ continue;
+ if (!dev->in_fs_metadata || !dev->writeable)
+ continue;
+
+ BUG_ON(!dev->pending_io);
+ bh = dev->pending_io;
+ wait_on_buffer(bh);
+ if (!buffer_uptodate(dev->pending_io)) {
+ if (do_barriers && dev->barriers) {
+ printk("btrfs: disabling barriers on dev %s\n",
+ dev->name);
+ set_buffer_uptodate(bh);
+ get_bh(bh);
+ lock_buffer(bh);
+ dev->barriers = 0;
+ ret = submit_bh(WRITE, bh);
+ BUG_ON(ret);
+ wait_on_buffer(bh);
+ if (!buffer_uptodate(bh))
+ total_errors++;
+ } else {
+ total_errors++;
+ }
+
+ }
+ dev->pending_io = NULL;
+ brelse(bh);
+ }
+ if (total_errors > max_errors) {
+ printk("btrfs: %d errors while writing supers\n", total_errors);
+ BUG();
+ }
+ return 0;
+}
+
+int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root)
+{
+ int ret;
+
+ ret = write_all_supers(root);
+ return ret;
+}
+
+int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
+{
+ radix_tree_delete(&fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid);
+ if (root->anon_super.s_dev) {
+ down_write(&root->anon_super.s_umount);
+ kill_anon_super(&root->anon_super);
+ }
+#if 0
+ if (root->in_sysfs)
+ btrfs_sysfs_del_root(root);
+#endif
+ if (root->node)
+ free_extent_buffer(root->node);
+ if (root->commit_root)
+ free_extent_buffer(root->commit_root);
+ if (root->name)
+ kfree(root->name);
+ kfree(root);
+ return 0;
+}
+
+static int del_fs_roots(struct btrfs_fs_info *fs_info)
+{
+ int ret;
+ struct btrfs_root *gang[8];
+ int i;
+
+ while(1) {
+ ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
+ (void **)gang, 0,
+ ARRAY_SIZE(gang));
+ if (!ret)
+ break;
+ for (i = 0; i < ret; i++)
+ btrfs_free_fs_root(fs_info, gang[i]);
+ }
+ return 0;
+}
+
+int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
+{
+ u64 root_objectid = 0;
+ struct btrfs_root *gang[8];
+ int i;
+ int ret;
+
+ while (1) {
+ ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
+ (void **)gang, root_objectid,
+ ARRAY_SIZE(gang));
+ if (!ret)
+ break;
+ for (i = 0; i < ret; i++) {
+ root_objectid = gang[i]->root_key.objectid;
+ ret = btrfs_find_dead_roots(fs_info->tree_root,
+ root_objectid, gang[i]);
+ BUG_ON(ret);
+ btrfs_orphan_cleanup(gang[i]);
+ }
+ root_objectid++;
+ }
+ return 0;
+}
+
+int btrfs_commit_super(struct btrfs_root *root)
+{
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ mutex_lock(&root->fs_info->cleaner_mutex);
+ btrfs_clean_old_snapshots(root);
+ mutex_unlock(&root->fs_info->cleaner_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_commit_transaction(trans, root);
+ BUG_ON(ret);
+ /* run commit again to drop the original snapshot */
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_commit_transaction(trans, root);
+ ret = btrfs_write_and_wait_transaction(NULL, root);
+ BUG_ON(ret);
+
+ ret = write_ctree_super(NULL, root);
+ return ret;
+}
+
+int close_ctree(struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret;
+
+ fs_info->closing = 1;
+ smp_mb();
+
+ kthread_stop(root->fs_info->transaction_kthread);
+ kthread_stop(root->fs_info->cleaner_kthread);
+
+ if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+ ret = btrfs_commit_super(root);
+ if (ret) {
+ printk("btrfs: commit super returns %d\n", ret);
+ }
+ }
+
+ if (fs_info->delalloc_bytes) {
+ printk("btrfs: at unmount delalloc count %Lu\n",
+ fs_info->delalloc_bytes);
+ }
+ if (fs_info->total_ref_cache_size) {
+ printk("btrfs: at umount reference cache size %Lu\n",
+ fs_info->total_ref_cache_size);
+ }
+
+ if (fs_info->extent_root->node)
+ free_extent_buffer(fs_info->extent_root->node);
+
+ if (fs_info->tree_root->node)
+ free_extent_buffer(fs_info->tree_root->node);
+
+ if (root->fs_info->chunk_root->node);
+ free_extent_buffer(root->fs_info->chunk_root->node);
+
+ if (root->fs_info->dev_root->node);
+ free_extent_buffer(root->fs_info->dev_root->node);
+
+ btrfs_free_block_groups(root->fs_info);
+
+ del_fs_roots(fs_info);
+
+ iput(fs_info->btree_inode);
+
+ btrfs_stop_workers(&fs_info->fixup_workers);
+ btrfs_stop_workers(&fs_info->delalloc_workers);
+ btrfs_stop_workers(&fs_info->workers);
+ btrfs_stop_workers(&fs_info->endio_workers);
+ btrfs_stop_workers(&fs_info->endio_write_workers);
+ btrfs_stop_workers(&fs_info->submit_workers);
+
+#if 0
+ while(!list_empty(&fs_info->hashers)) {
+ struct btrfs_hasher *hasher;
+ hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
+ hashers);
+ list_del(&hasher->hashers);
+ crypto_free_hash(&fs_info->hash_tfm);
+ kfree(hasher);
+ }
+#endif
+ btrfs_close_devices(fs_info->fs_devices);
+ btrfs_mapping_tree_free(&fs_info->mapping_tree);
+
+ bdi_destroy(&fs_info->bdi);
+
+ kfree(fs_info->extent_root);
+ kfree(fs_info->tree_root);
+ kfree(fs_info->chunk_root);
+ kfree(fs_info->dev_root);
+ return 0;
+}
+
+int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
+{
+ int ret;
+ struct inode *btree_inode = buf->first_page->mapping->host;
+
+ ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
+ if (!ret)
+ return ret;
+
+ ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
+ parent_transid);
+ return !ret;
+}
+
+int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
+{
+ struct inode *btree_inode = buf->first_page->mapping->host;
+ return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
+ buf);
+}
+
+void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
+{
+ struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
+ u64 transid = btrfs_header_generation(buf);
+ struct inode *btree_inode = root->fs_info->btree_inode;
+
+ WARN_ON(!btrfs_tree_locked(buf));
+ if (transid != root->fs_info->generation) {
+ printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
+ (unsigned long long)buf->start,
+ transid, root->fs_info->generation);
+ WARN_ON(1);
+ }
+ set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
+}
+
+void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
+{
+ /*
+ * looks as though older kernels can get into trouble with
+ * this code, they end up stuck in balance_dirty_pages forever
+ */
+ struct extent_io_tree *tree;
+ u64 num_dirty;
+ u64 start = 0;
+ unsigned long thresh = 32 * 1024 * 1024;
+ tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
+
+ if (current_is_pdflush() || current->flags & PF_MEMALLOC)
+ return;
+
+ num_dirty = count_range_bits(tree, &start, (u64)-1,
+ thresh, EXTENT_DIRTY);
+ if (num_dirty > thresh) {
+ balance_dirty_pages_ratelimited_nr(
+ root->fs_info->btree_inode->i_mapping, 1);
+ }
+ return;
+}
+
+int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
+{
+ struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
+ int ret;
+ ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
+ if (ret == 0) {
+ buf->flags |= EXTENT_UPTODATE;
+ }
+ return ret;
+}
+
+int btree_lock_page_hook(struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct extent_buffer *eb;
+ unsigned long len;
+ u64 bytenr = page_offset(page);
+
+ if (page->private == EXTENT_PAGE_PRIVATE)
+ goto out;
+
+ len = page->private >> 2;
+ eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
+ if (!eb)
+ goto out;
+
+ btrfs_tree_lock(eb);
+ spin_lock(&root->fs_info->hash_lock);
+ btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
+ spin_unlock(&root->fs_info->hash_lock);
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+out:
+ lock_page(page);
+ return 0;
+}
+
+static struct extent_io_ops btree_extent_io_ops = {
+ .write_cache_pages_lock_hook = btree_lock_page_hook,
+ .readpage_end_io_hook = btree_readpage_end_io_hook,
+ .submit_bio_hook = btree_submit_bio_hook,
+ /* note we're sharing with inode.c for the merge bio hook */
+ .merge_bio_hook = btrfs_merge_bio_hook,
+};
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
new file mode 100644
index 0000000..717e948
--- /dev/null
+++ b/fs/btrfs/disk-io.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __DISKIO__
+#define __DISKIO__
+
+#define BTRFS_SUPER_INFO_OFFSET (16 * 1024)
+#define BTRFS_SUPER_INFO_SIZE 4096
+struct btrfs_device;
+struct btrfs_fs_devices;
+
+struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
+ u32 blocksize, u64 parent_transid);
+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+ u64 parent_transid);
+struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
+ u64 bytenr, u32 blocksize);
+int clean_tree_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *buf);
+struct btrfs_root *open_ctree(struct super_block *sb,
+ struct btrfs_fs_devices *fs_devices,
+ char *options);
+int close_ctree(struct btrfs_root *root);
+int write_ctree_super(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+int btrfs_commit_super(struct btrfs_root *root);
+struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
+ u64 bytenr, u32 blocksize);
+struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
+ u64 root_objectid);
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location,
+ const char *name, int namelen);
+struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
+ struct btrfs_key *location);
+struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location);
+int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
+int btrfs_insert_dev_radix(struct btrfs_root *root,
+ struct block_device *bdev,
+ u64 device_id,
+ u64 block_start,
+ u64 num_blocks);
+void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr);
+int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
+void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
+int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid);
+int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
+int wait_on_tree_block_writeback(struct btrfs_root *root,
+ struct extent_buffer *buf);
+int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
+u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
+void btrfs_csum_final(u32 crc, char *result);
+int btrfs_open_device(struct btrfs_device *dev);
+int btrfs_verify_block_csum(struct btrfs_root *root,
+ struct extent_buffer *buf);
+int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
+ int metadata);
+int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
+ int rw, struct bio *bio, int mirror_num,
+ unsigned long bio_flags,
+ extent_submit_bio_hook_t *submit_bio_start,
+ extent_submit_bio_hook_t *submit_bio_done);
+
+int btrfs_congested_async(struct btrfs_fs_info *info, int iodone);
+unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
+int btrfs_write_tree_block(struct extent_buffer *buf);
+int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
+int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info);
+int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info);
+int btree_lock_page_hook(struct page *page);
+#endif
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
new file mode 100644
index 0000000..48b82cd
--- /dev/null
+++ b/fs/btrfs/export.c
@@ -0,0 +1,201 @@
+#include <linux/fs.h>
+#include <linux/types.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "btrfs_inode.h"
+#include "print-tree.h"
+#include "export.h"
+#include "compat.h"
+
+#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, parent_objectid)/4)
+#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, parent_root_objectid)/4)
+#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid)/4)
+
+static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
+ int connectable)
+{
+ struct btrfs_fid *fid = (struct btrfs_fid *)fh;
+ struct inode *inode = dentry->d_inode;
+ int len = *max_len;
+ int type;
+
+ if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) ||
+ (connectable && len < BTRFS_FID_SIZE_CONNECTABLE))
+ return 255;
+
+ len = BTRFS_FID_SIZE_NON_CONNECTABLE;
+ type = FILEID_BTRFS_WITHOUT_PARENT;
+
+ fid->objectid = BTRFS_I(inode)->location.objectid;
+ fid->root_objectid = BTRFS_I(inode)->root->objectid;
+ fid->gen = inode->i_generation;
+
+ if (connectable && !S_ISDIR(inode->i_mode)) {
+ struct inode *parent;
+ u64 parent_root_id;
+
+ spin_lock(&dentry->d_lock);
+
+ parent = dentry->d_parent->d_inode;
+ fid->parent_objectid = BTRFS_I(parent)->location.objectid;
+ fid->parent_gen = parent->i_generation;
+ parent_root_id = BTRFS_I(parent)->root->objectid;
+
+ spin_unlock(&dentry->d_lock);
+
+ if (parent_root_id != fid->root_objectid) {
+ fid->parent_root_objectid = parent_root_id;
+ len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
+ type = FILEID_BTRFS_WITH_PARENT_ROOT;
+ } else {
+ len = BTRFS_FID_SIZE_CONNECTABLE;
+ type = FILEID_BTRFS_WITH_PARENT;
+ }
+ }
+
+ *max_len = len;
+ return type;
+}
+
+static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
+ u64 root_objectid, u32 generation)
+{
+ struct btrfs_root *root;
+ struct inode *inode;
+ struct btrfs_key key;
+
+ key.objectid = root_objectid;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ key.offset = (u64)-1;
+
+ root = btrfs_read_fs_root_no_name(btrfs_sb(sb)->fs_info, &key);
+ if (IS_ERR(root))
+ return ERR_CAST(root);
+
+ key.objectid = objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.offset = 0;
+
+ inode = btrfs_iget(sb, &key, root, NULL);
+ if (IS_ERR(inode))
+ return (void *)inode;
+
+ if (generation != inode->i_generation) {
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+
+ return d_obtain_alias(inode);
+}
+
+static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
+ int fh_len, int fh_type)
+{
+ struct btrfs_fid *fid = (struct btrfs_fid *) fh;
+ u64 objectid, root_objectid;
+ u32 generation;
+
+ if (fh_type == FILEID_BTRFS_WITH_PARENT) {
+ if (fh_len != BTRFS_FID_SIZE_CONNECTABLE)
+ return NULL;
+ root_objectid = fid->root_objectid;
+ } else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
+ if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT)
+ return NULL;
+ root_objectid = fid->parent_root_objectid;
+ } else
+ return NULL;
+
+ objectid = fid->parent_objectid;
+ generation = fid->parent_gen;
+
+ return btrfs_get_dentry(sb, objectid, root_objectid, generation);
+}
+
+static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
+ int fh_len, int fh_type)
+{
+ struct btrfs_fid *fid = (struct btrfs_fid *) fh;
+ u64 objectid, root_objectid;
+ u32 generation;
+
+ if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
+ fh_len != BTRFS_FID_SIZE_CONNECTABLE) &&
+ (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
+ fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
+ (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
+ fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE))
+ return NULL;
+
+ objectid = fid->objectid;
+ root_objectid = fid->root_objectid;
+ generation = fid->gen;
+
+ return btrfs_get_dentry(sb, objectid, root_objectid, generation);
+}
+
+static struct dentry *btrfs_get_parent(struct dentry *child)
+{
+ struct inode *dir = child->d_inode;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int slot;
+ u64 objectid;
+ int ret;
+
+ path = btrfs_alloc_path();
+
+ key.objectid = dir->i_ino;
+ btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0) {
+ /* Error */
+ btrfs_free_path(path);
+ return ERR_PTR(ret);
+ }
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ if (ret) {
+ /* btrfs_search_slot() returns the slot where we'd want to
+ insert a backref for parent inode #0xFFFFFFFFFFFFFFFF.
+ The _real_ backref, telling us what the parent inode
+ _actually_ is, will be in the slot _before_ the one
+ that btrfs_search_slot() returns. */
+ if (!slot) {
+ /* Unless there is _no_ key in the tree before... */
+ btrfs_free_path(path);
+ return ERR_PTR(-EIO);
+ }
+ slot--;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ btrfs_free_path(path);
+
+ if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY)
+ return ERR_PTR(-EINVAL);
+
+ objectid = key.offset;
+
+ /* If we are already at the root of a subvol, return the real root */
+ if (objectid == dir->i_ino)
+ return dget(dir->i_sb->s_root);
+
+ /* Build a new key for the inode item */
+ key.objectid = objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.offset = 0;
+
+ return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
+}
+
+const struct export_operations btrfs_export_ops = {
+ .encode_fh = btrfs_encode_fh,
+ .fh_to_dentry = btrfs_fh_to_dentry,
+ .fh_to_parent = btrfs_fh_to_parent,
+ .get_parent = btrfs_get_parent,
+};
diff --git a/fs/btrfs/export.h b/fs/btrfs/export.h
new file mode 100644
index 0000000..074348a
--- /dev/null
+++ b/fs/btrfs/export.h
@@ -0,0 +1,19 @@
+#ifndef BTRFS_EXPORT_H
+#define BTRFS_EXPORT_H
+
+#include <linux/exportfs.h>
+
+extern const struct export_operations btrfs_export_ops;
+
+struct btrfs_fid {
+ u64 objectid;
+ u64 root_objectid;
+ u32 gen;
+
+ u64 parent_objectid;
+ u32 parent_gen;
+
+ u64 parent_root_objectid;
+} __attribute__ ((packed));
+
+#endif
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
new file mode 100644
index 0000000..ee73efe
--- /dev/null
+++ b/fs/btrfs/extent-tree.c
@@ -0,0 +1,5918 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#include <linux/sched.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include "hash.h"
+#include "crc32c.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "transaction.h"
+#include "volumes.h"
+#include "locking.h"
+#include "ref-cache.h"
+
+#define PENDING_EXTENT_INSERT 0
+#define PENDING_EXTENT_DELETE 1
+#define PENDING_BACKREF_UPDATE 2
+
+struct pending_extent_op {
+ int type;
+ u64 bytenr;
+ u64 num_bytes;
+ u64 parent;
+ u64 orig_parent;
+ u64 generation;
+ u64 orig_generation;
+ int level;
+ struct list_head list;
+ int del;
+};
+
+static int finish_current_insert(struct btrfs_trans_handle *trans, struct
+ btrfs_root *extent_root, int all);
+static int del_pending_extents(struct btrfs_trans_handle *trans, struct
+ btrfs_root *extent_root, int all);
+static struct btrfs_block_group_cache *
+__btrfs_find_block_group(struct btrfs_root *root,
+ struct btrfs_block_group_cache *hint,
+ u64 search_start, int data, int owner);
+static int pin_down_bytes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, int is_data);
+static int update_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, int alloc,
+ int mark_free);
+
+static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
+{
+ return (cache->flags & bits) == bits;
+}
+
+/*
+ * this adds the block group to the fs_info rb tree for the block group
+ * cache
+ */
+int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
+ struct btrfs_block_group_cache *block_group)
+{
+ struct rb_node **p;
+ struct rb_node *parent = NULL;
+ struct btrfs_block_group_cache *cache;
+
+ spin_lock(&info->block_group_cache_lock);
+ p = &info->block_group_cache_tree.rb_node;
+
+ while (*p) {
+ parent = *p;
+ cache = rb_entry(parent, struct btrfs_block_group_cache,
+ cache_node);
+ if (block_group->key.objectid < cache->key.objectid) {
+ p = &(*p)->rb_left;
+ } else if (block_group->key.objectid > cache->key.objectid) {
+ p = &(*p)->rb_right;
+ } else {
+ spin_unlock(&info->block_group_cache_lock);
+ return -EEXIST;
+ }
+ }
+
+ rb_link_node(&block_group->cache_node, parent, p);
+ rb_insert_color(&block_group->cache_node,
+ &info->block_group_cache_tree);
+ spin_unlock(&info->block_group_cache_lock);
+
+ return 0;
+}
+
+/*
+ * This will return the block group at or after bytenr if contains is 0, else
+ * it will return the block group that contains the bytenr
+ */
+static struct btrfs_block_group_cache *
+block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
+ int contains)
+{
+ struct btrfs_block_group_cache *cache, *ret = NULL;
+ struct rb_node *n;
+ u64 end, start;
+
+ spin_lock(&info->block_group_cache_lock);
+ n = info->block_group_cache_tree.rb_node;
+
+ while (n) {
+ cache = rb_entry(n, struct btrfs_block_group_cache,
+ cache_node);
+ end = cache->key.objectid + cache->key.offset - 1;
+ start = cache->key.objectid;
+
+ if (bytenr < start) {
+ if (!contains && (!ret || start < ret->key.objectid))
+ ret = cache;
+ n = n->rb_left;
+ } else if (bytenr > start) {
+ if (contains && bytenr <= end) {
+ ret = cache;
+ break;
+ }
+ n = n->rb_right;
+ } else {
+ ret = cache;
+ break;
+ }
+ }
+ spin_unlock(&info->block_group_cache_lock);
+
+ return ret;
+}
+
+/*
+ * this is only called by cache_block_group, since we could have freed extents
+ * we need to check the pinned_extents for any extents that can't be used yet
+ * since their free space will be released as soon as the transaction commits.
+ */
+static int add_new_free_space(struct btrfs_block_group_cache *block_group,
+ struct btrfs_fs_info *info, u64 start, u64 end)
+{
+ u64 extent_start, extent_end, size;
+ int ret;
+
+ mutex_lock(&info->pinned_mutex);
+ while (start < end) {
+ ret = find_first_extent_bit(&info->pinned_extents, start,
+ &extent_start, &extent_end,
+ EXTENT_DIRTY);
+ if (ret)
+ break;
+
+ if (extent_start == start) {
+ start = extent_end + 1;
+ } else if (extent_start > start && extent_start < end) {
+ size = extent_start - start;
+ ret = btrfs_add_free_space_lock(block_group, start,
+ size);
+ BUG_ON(ret);
+ start = extent_end + 1;
+ } else {
+ break;
+ }
+ }
+
+ if (start < end) {
+ size = end - start;
+ ret = btrfs_add_free_space_lock(block_group, start, size);
+ BUG_ON(ret);
+ }
+ mutex_unlock(&info->pinned_mutex);
+
+ return 0;
+}
+
+static int cache_block_group(struct btrfs_root *root,
+ struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_path *path;
+ int ret = 0;
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ int slot;
+ u64 last = 0;
+ u64 first_free;
+ int found = 0;
+
+ if (!block_group)
+ return 0;
+
+ root = root->fs_info->extent_root;
+
+ if (block_group->cached)
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = 2;
+ /*
+ * we get into deadlocks with paths held by callers of this function.
+ * since the alloc_mutex is protecting things right now, just
+ * skip the locking here
+ */
+ path->skip_locking = 1;
+ first_free = max_t(u64, block_group->key.objectid,
+ BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
+ key.objectid = block_group->key.objectid;
+ key.offset = 0;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+ ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
+ if (ret < 0)
+ goto err;
+ if (ret == 0) {
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid + key.offset > first_free)
+ first_free = key.objectid + key.offset;
+ }
+ while(1) {
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto err;
+ if (ret == 0)
+ continue;
+ else
+ break;
+ }
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid < block_group->key.objectid)
+ goto next;
+
+ if (key.objectid >= block_group->key.objectid +
+ block_group->key.offset)
+ break;
+
+ if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
+ if (!found) {
+ last = first_free;
+ found = 1;
+ }
+
+ add_new_free_space(block_group, root->fs_info, last,
+ key.objectid);
+
+ last = key.objectid + key.offset;
+ }
+next:
+ path->slots[0]++;
+ }
+
+ if (!found)
+ last = first_free;
+
+ add_new_free_space(block_group, root->fs_info, last,
+ block_group->key.objectid +
+ block_group->key.offset);
+
+ block_group->cached = 1;
+ ret = 0;
+err:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * return the block group that starts at or after bytenr
+ */
+struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
+ btrfs_fs_info *info,
+ u64 bytenr)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = block_group_cache_tree_search(info, bytenr, 0);
+
+ return cache;
+}
+
+/*
+ * return the block group that contains teh given bytenr
+ */
+struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
+ btrfs_fs_info *info,
+ u64 bytenr)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = block_group_cache_tree_search(info, bytenr, 1);
+
+ return cache;
+}
+
+static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
+ u64 flags)
+{
+ struct list_head *head = &info->space_info;
+ struct list_head *cur;
+ struct btrfs_space_info *found;
+ list_for_each(cur, head) {
+ found = list_entry(cur, struct btrfs_space_info, list);
+ if (found->flags == flags)
+ return found;
+ }
+ return NULL;
+}
+
+static u64 div_factor(u64 num, int factor)
+{
+ if (factor == 10)
+ return num;
+ num *= factor;
+ do_div(num, 10);
+ return num;
+}
+
+static struct btrfs_block_group_cache *
+__btrfs_find_block_group(struct btrfs_root *root,
+ struct btrfs_block_group_cache *hint,
+ u64 search_start, int data, int owner)
+{
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_block_group_cache *found_group = NULL;
+ struct btrfs_fs_info *info = root->fs_info;
+ u64 used;
+ u64 last = 0;
+ u64 free_check;
+ int full_search = 0;
+ int factor = 10;
+ int wrapped = 0;
+
+ if (data & BTRFS_BLOCK_GROUP_METADATA)
+ factor = 9;
+
+ if (search_start) {
+ struct btrfs_block_group_cache *shint;
+ shint = btrfs_lookup_first_block_group(info, search_start);
+ if (shint && block_group_bits(shint, data)) {
+ spin_lock(&shint->lock);
+ used = btrfs_block_group_used(&shint->item);
+ if (used + shint->pinned + shint->reserved <
+ div_factor(shint->key.offset, factor)) {
+ spin_unlock(&shint->lock);
+ return shint;
+ }
+ spin_unlock(&shint->lock);
+ }
+ }
+ if (hint && block_group_bits(hint, data)) {
+ spin_lock(&hint->lock);
+ used = btrfs_block_group_used(&hint->item);
+ if (used + hint->pinned + hint->reserved <
+ div_factor(hint->key.offset, factor)) {
+ spin_unlock(&hint->lock);
+ return hint;
+ }
+ spin_unlock(&hint->lock);
+ last = hint->key.objectid + hint->key.offset;
+ } else {
+ if (hint)
+ last = max(hint->key.objectid, search_start);
+ else
+ last = search_start;
+ }
+again:
+ while (1) {
+ cache = btrfs_lookup_first_block_group(root->fs_info, last);
+ if (!cache)
+ break;
+
+ spin_lock(&cache->lock);
+ last = cache->key.objectid + cache->key.offset;
+ used = btrfs_block_group_used(&cache->item);
+
+ if (block_group_bits(cache, data)) {
+ free_check = div_factor(cache->key.offset, factor);
+ if (used + cache->pinned + cache->reserved <
+ free_check) {
+ found_group = cache;
+ spin_unlock(&cache->lock);
+ goto found;
+ }
+ }
+ spin_unlock(&cache->lock);
+ cond_resched();
+ }
+ if (!wrapped) {
+ last = search_start;
+ wrapped = 1;
+ goto again;
+ }
+ if (!full_search && factor < 10) {
+ last = search_start;
+ full_search = 1;
+ factor = 10;
+ goto again;
+ }
+found:
+ return found_group;
+}
+
+struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
+ struct btrfs_block_group_cache
+ *hint, u64 search_start,
+ int data, int owner)
+{
+
+ struct btrfs_block_group_cache *ret;
+ ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
+ return ret;
+}
+
+/* simple helper to search for an existing extent at a given offset */
+int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_path *path;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ key.objectid = start;
+ key.offset = len;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
+ ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
+ 0, 0);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * Back reference rules. Back refs have three main goals:
+ *
+ * 1) differentiate between all holders of references to an extent so that
+ * when a reference is dropped we can make sure it was a valid reference
+ * before freeing the extent.
+ *
+ * 2) Provide enough information to quickly find the holders of an extent
+ * if we notice a given block is corrupted or bad.
+ *
+ * 3) Make it easy to migrate blocks for FS shrinking or storage pool
+ * maintenance. This is actually the same as #2, but with a slightly
+ * different use case.
+ *
+ * File extents can be referenced by:
+ *
+ * - multiple snapshots, subvolumes, or different generations in one subvol
+ * - different files inside a single subvolume
+ * - different offsets inside a file (bookend extents in file.c)
+ *
+ * The extent ref structure has fields for:
+ *
+ * - Objectid of the subvolume root
+ * - Generation number of the tree holding the reference
+ * - objectid of the file holding the reference
+ * - number of references holding by parent node (alway 1 for tree blocks)
+ *
+ * Btree leaf may hold multiple references to a file extent. In most cases,
+ * these references are from same file and the corresponding offsets inside
+ * the file are close together.
+ *
+ * When a file extent is allocated the fields are filled in:
+ * (root_key.objectid, trans->transid, inode objectid, 1)
+ *
+ * When a leaf is cow'd new references are added for every file extent found
+ * in the leaf. It looks similar to the create case, but trans->transid will
+ * be different when the block is cow'd.
+ *
+ * (root_key.objectid, trans->transid, inode objectid,
+ * number of references in the leaf)
+ *
+ * When a file extent is removed either during snapshot deletion or
+ * file truncation, we find the corresponding back reference and check
+ * the following fields:
+ *
+ * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
+ * inode objectid)
+ *
+ * Btree extents can be referenced by:
+ *
+ * - Different subvolumes
+ * - Different generations of the same subvolume
+ *
+ * When a tree block is created, back references are inserted:
+ *
+ * (root->root_key.objectid, trans->transid, level, 1)
+ *
+ * When a tree block is cow'd, new back references are added for all the
+ * blocks it points to. If the tree block isn't in reference counted root,
+ * the old back references are removed. These new back references are of
+ * the form (trans->transid will have increased since creation):
+ *
+ * (root->root_key.objectid, trans->transid, level, 1)
+ *
+ * When a backref is in deleting, the following fields are checked:
+ *
+ * if backref was for a tree root:
+ * (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
+ * else
+ * (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
+ *
+ * Back Reference Key composing:
+ *
+ * The key objectid corresponds to the first byte in the extent, the key
+ * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
+ * byte of parent extent. If a extent is tree root, the key offset is set
+ * to the key objectid.
+ */
+
+static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 parent,
+ u64 ref_root, u64 ref_generation,
+ u64 owner_objectid, int del)
+{
+ struct btrfs_key key;
+ struct btrfs_extent_ref *ref;
+ struct extent_buffer *leaf;
+ u64 ref_objectid;
+ int ret;
+
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_REF_KEY;
+ key.offset = parent;
+
+ ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
+ ref_objectid = btrfs_ref_objectid(leaf, ref);
+ if (btrfs_ref_root(leaf, ref) != ref_root ||
+ btrfs_ref_generation(leaf, ref) != ref_generation ||
+ (ref_objectid != owner_objectid &&
+ ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
+ ret = -EIO;
+ WARN_ON(1);
+ goto out;
+ }
+ ret = 0;
+out:
+ return ret;
+}
+
+/*
+ * updates all the backrefs that are pending on update_list for the
+ * extent_root
+ */
+static int noinline update_backrefs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct btrfs_path *path,
+ struct list_head *update_list)
+{
+ struct btrfs_key key;
+ struct btrfs_extent_ref *ref;
+ struct btrfs_fs_info *info = extent_root->fs_info;
+ struct pending_extent_op *op;
+ struct extent_buffer *leaf;
+ int ret = 0;
+ struct list_head *cur = update_list->next;
+ u64 ref_objectid;
+ u64 ref_root = extent_root->root_key.objectid;
+
+ op = list_entry(cur, struct pending_extent_op, list);
+
+search:
+ key.objectid = op->bytenr;
+ key.type = BTRFS_EXTENT_REF_KEY;
+ key.offset = op->orig_parent;
+
+ ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 1);
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+
+loop:
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
+
+ ref_objectid = btrfs_ref_objectid(leaf, ref);
+
+ if (btrfs_ref_root(leaf, ref) != ref_root ||
+ btrfs_ref_generation(leaf, ref) != op->orig_generation ||
+ (ref_objectid != op->level &&
+ ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
+ printk(KERN_ERR "couldn't find %Lu, parent %Lu, root %Lu, "
+ "owner %u\n", op->bytenr, op->orig_parent,
+ ref_root, op->level);
+ btrfs_print_leaf(extent_root, leaf);
+ BUG();
+ }
+
+ key.objectid = op->bytenr;
+ key.offset = op->parent;
+ key.type = BTRFS_EXTENT_REF_KEY;
+ ret = btrfs_set_item_key_safe(trans, extent_root, path, &key);
+ BUG_ON(ret);
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
+ btrfs_set_ref_generation(leaf, ref, op->generation);
+
+ cur = cur->next;
+
+ list_del_init(&op->list);
+ unlock_extent(&info->extent_ins, op->bytenr,
+ op->bytenr + op->num_bytes - 1, GFP_NOFS);
+ kfree(op);
+
+ if (cur == update_list) {
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(extent_root, path);
+ goto out;
+ }
+
+ op = list_entry(cur, struct pending_extent_op, list);
+
+ path->slots[0]++;
+ while (path->slots[0] < btrfs_header_nritems(leaf)) {
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid == op->bytenr &&
+ key.type == BTRFS_EXTENT_REF_KEY)
+ goto loop;
+ path->slots[0]++;
+ }
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(extent_root, path);
+ goto search;
+
+out:
+ return 0;
+}
+
+static int noinline insert_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct btrfs_path *path,
+ struct list_head *insert_list, int nr)
+{
+ struct btrfs_key *keys;
+ u32 *data_size;
+ struct pending_extent_op *op;
+ struct extent_buffer *leaf;
+ struct list_head *cur = insert_list->next;
+ struct btrfs_fs_info *info = extent_root->fs_info;
+ u64 ref_root = extent_root->root_key.objectid;
+ int i = 0, last = 0, ret;
+ int total = nr * 2;
+
+ if (!nr)
+ return 0;
+
+ keys = kzalloc(total * sizeof(struct btrfs_key), GFP_NOFS);
+ if (!keys)
+ return -ENOMEM;
+
+ data_size = kzalloc(total * sizeof(u32), GFP_NOFS);
+ if (!data_size) {
+ kfree(keys);
+ return -ENOMEM;
+ }
+
+ list_for_each_entry(op, insert_list, list) {
+ keys[i].objectid = op->bytenr;
+ keys[i].offset = op->num_bytes;
+ keys[i].type = BTRFS_EXTENT_ITEM_KEY;
+ data_size[i] = sizeof(struct btrfs_extent_item);
+ i++;
+
+ keys[i].objectid = op->bytenr;
+ keys[i].offset = op->parent;
+ keys[i].type = BTRFS_EXTENT_REF_KEY;
+ data_size[i] = sizeof(struct btrfs_extent_ref);
+ i++;
+ }
+
+ op = list_entry(cur, struct pending_extent_op, list);
+ i = 0;
+ while (i < total) {
+ int c;
+ ret = btrfs_insert_some_items(trans, extent_root, path,
+ keys+i, data_size+i, total-i);
+ BUG_ON(ret < 0);
+
+ if (last && ret > 1)
+ BUG();
+
+ leaf = path->nodes[0];
+ for (c = 0; c < ret; c++) {
+ int ref_first = keys[i].type == BTRFS_EXTENT_REF_KEY;
+
+ /*
+ * if the first item we inserted was a backref, then
+ * the EXTENT_ITEM will be the odd c's, else it will
+ * be the even c's
+ */
+ if ((ref_first && (c % 2)) ||
+ (!ref_first && !(c % 2))) {
+ struct btrfs_extent_item *itm;
+
+ itm = btrfs_item_ptr(leaf, path->slots[0] + c,
+ struct btrfs_extent_item);
+ btrfs_set_extent_refs(path->nodes[0], itm, 1);
+ op->del++;
+ } else {
+ struct btrfs_extent_ref *ref;
+
+ ref = btrfs_item_ptr(leaf, path->slots[0] + c,
+ struct btrfs_extent_ref);
+ btrfs_set_ref_root(leaf, ref, ref_root);
+ btrfs_set_ref_generation(leaf, ref,
+ op->generation);
+ btrfs_set_ref_objectid(leaf, ref, op->level);
+ btrfs_set_ref_num_refs(leaf, ref, 1);
+ op->del++;
+ }
+
+ /*
+ * using del to see when its ok to free up the
+ * pending_extent_op. In the case where we insert the
+ * last item on the list in order to help do batching
+ * we need to not free the extent op until we actually
+ * insert the extent_item
+ */
+ if (op->del == 2) {
+ unlock_extent(&info->extent_ins, op->bytenr,
+ op->bytenr + op->num_bytes - 1,
+ GFP_NOFS);
+ cur = cur->next;
+ list_del_init(&op->list);
+ kfree(op);
+ if (cur != insert_list)
+ op = list_entry(cur,
+ struct pending_extent_op,
+ list);
+ }
+ }
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(extent_root, path);
+
+ /*
+ * Ok backref's and items usually go right next to eachother,
+ * but if we could only insert 1 item that means that we
+ * inserted on the end of a leaf, and we have no idea what may
+ * be on the next leaf so we just play it safe. In order to
+ * try and help this case we insert the last thing on our
+ * insert list so hopefully it will end up being the last
+ * thing on the leaf and everything else will be before it,
+ * which will let us insert a whole bunch of items at the same
+ * time.
+ */
+ if (ret == 1 && !last && (i + ret < total)) {
+ /*
+ * last: where we will pick up the next time around
+ * i: our current key to insert, will be total - 1
+ * cur: the current op we are screwing with
+ * op: duh
+ */
+ last = i + ret;
+ i = total - 1;
+ cur = insert_list->prev;
+ op = list_entry(cur, struct pending_extent_op, list);
+ } else if (last) {
+ /*
+ * ok we successfully inserted the last item on the
+ * list, lets reset everything
+ *
+ * i: our current key to insert, so where we left off
+ * last time
+ * last: done with this
+ * cur: the op we are messing with
+ * op: duh
+ * total: since we inserted the last key, we need to
+ * decrement total so we dont overflow
+ */
+ i = last;
+ last = 0;
+ total--;
+ if (i < total) {
+ cur = insert_list->next;
+ op = list_entry(cur, struct pending_extent_op,
+ list);
+ }
+ } else {
+ i += ret;
+ }
+
+ cond_resched();
+ }
+ ret = 0;
+ kfree(keys);
+ kfree(data_size);
+ return ret;
+}
+
+static int noinline insert_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 parent,
+ u64 ref_root, u64 ref_generation,
+ u64 owner_objectid)
+{
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ struct btrfs_extent_ref *ref;
+ u32 num_refs;
+ int ret;
+
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_REF_KEY;
+ key.offset = parent;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
+ if (ret == 0) {
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref);
+ btrfs_set_ref_root(leaf, ref, ref_root);
+ btrfs_set_ref_generation(leaf, ref, ref_generation);
+ btrfs_set_ref_objectid(leaf, ref, owner_objectid);
+ btrfs_set_ref_num_refs(leaf, ref, 1);
+ } else if (ret == -EEXIST) {
+ u64 existing_owner;
+ BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref);
+ if (btrfs_ref_root(leaf, ref) != ref_root ||
+ btrfs_ref_generation(leaf, ref) != ref_generation) {
+ ret = -EIO;
+ WARN_ON(1);
+ goto out;
+ }
+
+ num_refs = btrfs_ref_num_refs(leaf, ref);
+ BUG_ON(num_refs == 0);
+ btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
+
+ existing_owner = btrfs_ref_objectid(leaf, ref);
+ if (existing_owner != owner_objectid &&
+ existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
+ btrfs_set_ref_objectid(leaf, ref,
+ BTRFS_MULTIPLE_OBJECTIDS);
+ }
+ ret = 0;
+ } else {
+ goto out;
+ }
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
+ btrfs_release_path(root, path);
+ return ret;
+}
+
+static int noinline remove_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_extent_ref *ref;
+ u32 num_refs;
+ int ret = 0;
+
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
+ num_refs = btrfs_ref_num_refs(leaf, ref);
+ BUG_ON(num_refs == 0);
+ num_refs -= 1;
+ if (num_refs == 0) {
+ ret = btrfs_del_item(trans, root, path);
+ } else {
+ btrfs_set_ref_num_refs(leaf, ref, num_refs);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ btrfs_release_path(root, path);
+ return ret;
+}
+
+static int noinline free_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct list_head *del_list)
+{
+ struct btrfs_fs_info *info = extent_root->fs_info;
+ struct btrfs_path *path;
+ struct btrfs_key key, found_key;
+ struct extent_buffer *leaf;
+ struct list_head *cur;
+ struct pending_extent_op *op;
+ struct btrfs_extent_item *ei;
+ int ret, num_to_del, extent_slot = 0, found_extent = 0;
+ u32 refs;
+ u64 bytes_freed = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->reada = 1;
+
+search:
+ /* search for the backref for the current ref we want to delete */
+ cur = del_list->next;
+ op = list_entry(cur, struct pending_extent_op, list);
+ ret = lookup_extent_backref(trans, extent_root, path, op->bytenr,
+ op->orig_parent,
+ extent_root->root_key.objectid,
+ op->orig_generation, op->level, 1);
+ if (ret) {
+ printk("Unable to find backref byte nr %Lu root %Lu gen %Lu "
+ "owner %u\n", op->bytenr,
+ extent_root->root_key.objectid, op->orig_generation,
+ op->level);
+ btrfs_print_leaf(extent_root, path->nodes[0]);
+ WARN_ON(1);
+ goto out;
+ }
+
+ extent_slot = path->slots[0];
+ num_to_del = 1;
+ found_extent = 0;
+
+ /*
+ * if we aren't the first item on the leaf we can move back one and see
+ * if our ref is right next to our extent item
+ */
+ if (likely(extent_slot)) {
+ extent_slot--;
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ extent_slot);
+ if (found_key.objectid == op->bytenr &&
+ found_key.type == BTRFS_EXTENT_ITEM_KEY &&
+ found_key.offset == op->num_bytes) {
+ num_to_del++;
+ found_extent = 1;
+ }
+ }
+
+ /*
+ * if we didn't find the extent we need to delete the backref and then
+ * search for the extent item key so we can update its ref count
+ */
+ if (!found_extent) {
+ key.objectid = op->bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = op->num_bytes;
+
+ ret = remove_extent_backref(trans, extent_root, path);
+ BUG_ON(ret);
+ btrfs_release_path(extent_root, path);
+ ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
+ BUG_ON(ret);
+ extent_slot = path->slots[0];
+ }
+
+ /* this is where we update the ref count for the extent */
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item);
+ refs = btrfs_extent_refs(leaf, ei);
+ BUG_ON(refs == 0);
+ refs--;
+ btrfs_set_extent_refs(leaf, ei, refs);
+
+ btrfs_mark_buffer_dirty(leaf);
+
+ /*
+ * This extent needs deleting. The reason cur_slot is extent_slot +
+ * num_to_del is because extent_slot points to the slot where the extent
+ * is, and if the backref was not right next to the extent we will be
+ * deleting at least 1 item, and will want to start searching at the
+ * slot directly next to extent_slot. However if we did find the
+ * backref next to the extent item them we will be deleting at least 2
+ * items and will want to start searching directly after the ref slot
+ */
+ if (!refs) {
+ struct list_head *pos, *n, *end;
+ int cur_slot = extent_slot+num_to_del;
+ u64 super_used;
+ u64 root_used;
+
+ path->slots[0] = extent_slot;
+ bytes_freed = op->num_bytes;
+
+ mutex_lock(&info->pinned_mutex);
+ ret = pin_down_bytes(trans, extent_root, op->bytenr,
+ op->num_bytes, op->level >=
+ BTRFS_FIRST_FREE_OBJECTID);
+ mutex_unlock(&info->pinned_mutex);
+ BUG_ON(ret < 0);
+ op->del = ret;
+
+ /*
+ * we need to see if we can delete multiple things at once, so
+ * start looping through the list of extents we are wanting to
+ * delete and see if their extent/backref's are right next to
+ * eachother and the extents only have 1 ref
+ */
+ for (pos = cur->next; pos != del_list; pos = pos->next) {
+ struct pending_extent_op *tmp;
+
+ tmp = list_entry(pos, struct pending_extent_op, list);
+
+ /* we only want to delete extent+ref at this stage */
+ if (cur_slot >= btrfs_header_nritems(leaf) - 1)
+ break;
+
+ btrfs_item_key_to_cpu(leaf, &found_key, cur_slot);
+ if (found_key.objectid != tmp->bytenr ||
+ found_key.type != BTRFS_EXTENT_ITEM_KEY ||
+ found_key.offset != tmp->num_bytes)
+ break;
+
+ /* check to make sure this extent only has one ref */
+ ei = btrfs_item_ptr(leaf, cur_slot,
+ struct btrfs_extent_item);
+ if (btrfs_extent_refs(leaf, ei) != 1)
+ break;
+
+ btrfs_item_key_to_cpu(leaf, &found_key, cur_slot+1);
+ if (found_key.objectid != tmp->bytenr ||
+ found_key.type != BTRFS_EXTENT_REF_KEY ||
+ found_key.offset != tmp->orig_parent)
+ break;
+
+ /*
+ * the ref is right next to the extent, we can set the
+ * ref count to 0 since we will delete them both now
+ */
+ btrfs_set_extent_refs(leaf, ei, 0);
+
+ /* pin down the bytes for this extent */
+ mutex_lock(&info->pinned_mutex);
+ ret = pin_down_bytes(trans, extent_root, tmp->bytenr,
+ tmp->num_bytes, tmp->level >=
+ BTRFS_FIRST_FREE_OBJECTID);
+ mutex_unlock(&info->pinned_mutex);
+ BUG_ON(ret < 0);
+
+ /*
+ * use the del field to tell if we need to go ahead and
+ * free up the extent when we delete the item or not.
+ */
+ tmp->del = ret;
+ bytes_freed += tmp->num_bytes;
+
+ num_to_del += 2;
+ cur_slot += 2;
+ }
+ end = pos;
+
+ /* update the free space counters */
+ spin_lock_irq(&info->delalloc_lock);
+ super_used = btrfs_super_bytes_used(&info->super_copy);
+ btrfs_set_super_bytes_used(&info->super_copy,
+ super_used - bytes_freed);
+ spin_unlock_irq(&info->delalloc_lock);
+
+ root_used = btrfs_root_used(&extent_root->root_item);
+ btrfs_set_root_used(&extent_root->root_item,
+ root_used - bytes_freed);
+
+ /* delete the items */
+ ret = btrfs_del_items(trans, extent_root, path,
+ path->slots[0], num_to_del);
+ BUG_ON(ret);
+
+ /*
+ * loop through the extents we deleted and do the cleanup work
+ * on them
+ */
+ for (pos = cur, n = pos->next; pos != end;
+ pos = n, n = pos->next) {
+ struct pending_extent_op *tmp;
+#ifdef BIO_RW_DISCARD
+ u64 map_length;
+ struct btrfs_multi_bio *multi = NULL;
+#endif
+ tmp = list_entry(pos, struct pending_extent_op, list);
+
+ /*
+ * remember tmp->del tells us wether or not we pinned
+ * down the extent
+ */
+ ret = update_block_group(trans, extent_root,
+ tmp->bytenr, tmp->num_bytes, 0,
+ tmp->del);
+ BUG_ON(ret);
+
+#ifdef BIO_RW_DISCARD
+ ret = btrfs_map_block(&info->mapping_tree, READ,
+ tmp->bytenr, &map_length, &multi,
+ 0);
+ if (!ret) {
+ struct btrfs_bio_stripe *stripe;
+ int i;
+
+ stripe = multi->stripe;
+
+ if (map_length > tmp->num_bytes)
+ map_length = tmp->num_bytes;
+
+ for (i = 0; i < multi->num_stripes;
+ i++, stripe++)
+ blkdev_issue_discard(stripe->dev->bdev,
+ stripe->physical >> 9,
+ map_length >> 9);
+ kfree(multi);
+ }
+#endif
+ list_del_init(&tmp->list);
+ unlock_extent(&info->extent_ins, tmp->bytenr,
+ tmp->bytenr + tmp->num_bytes - 1,
+ GFP_NOFS);
+ kfree(tmp);
+ }
+ } else if (refs && found_extent) {
+ /*
+ * the ref and extent were right next to eachother, but the
+ * extent still has a ref, so just free the backref and keep
+ * going
+ */
+ ret = remove_extent_backref(trans, extent_root, path);
+ BUG_ON(ret);
+
+ list_del_init(&op->list);
+ unlock_extent(&info->extent_ins, op->bytenr,
+ op->bytenr + op->num_bytes - 1, GFP_NOFS);
+ kfree(op);
+ } else {
+ /*
+ * the extent has multiple refs and the backref we were looking
+ * for was not right next to it, so just unlock and go next,
+ * we're good to go
+ */
+ list_del_init(&op->list);
+ unlock_extent(&info->extent_ins, op->bytenr,
+ op->bytenr + op->num_bytes - 1, GFP_NOFS);
+ kfree(op);
+ }
+
+ btrfs_release_path(extent_root, path);
+ if (!list_empty(del_list))
+ goto search;
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 orig_parent, u64 parent,
+ u64 orig_root, u64 ref_root,
+ u64 orig_generation, u64 ref_generation,
+ u64 owner_objectid)
+{
+ int ret;
+ struct btrfs_root *extent_root = root->fs_info->extent_root;
+ struct btrfs_path *path;
+
+ if (root == root->fs_info->extent_root) {
+ struct pending_extent_op *extent_op;
+ u64 num_bytes;
+
+ BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
+ num_bytes = btrfs_level_size(root, (int)owner_objectid);
+ mutex_lock(&root->fs_info->extent_ins_mutex);
+ if (test_range_bit(&root->fs_info->extent_ins, bytenr,
+ bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
+ u64 priv;
+ ret = get_state_private(&root->fs_info->extent_ins,
+ bytenr, &priv);
+ BUG_ON(ret);
+ extent_op = (struct pending_extent_op *)
+ (unsigned long)priv;
+ BUG_ON(extent_op->parent != orig_parent);
+ BUG_ON(extent_op->generation != orig_generation);
+
+ extent_op->parent = parent;
+ extent_op->generation = ref_generation;
+ } else {
+ extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
+ BUG_ON(!extent_op);
+
+ extent_op->type = PENDING_BACKREF_UPDATE;
+ extent_op->bytenr = bytenr;
+ extent_op->num_bytes = num_bytes;
+ extent_op->parent = parent;
+ extent_op->orig_parent = orig_parent;
+ extent_op->generation = ref_generation;
+ extent_op->orig_generation = orig_generation;
+ extent_op->level = (int)owner_objectid;
+ INIT_LIST_HEAD(&extent_op->list);
+ extent_op->del = 0;
+
+ set_extent_bits(&root->fs_info->extent_ins,
+ bytenr, bytenr + num_bytes - 1,
+ EXTENT_WRITEBACK, GFP_NOFS);
+ set_state_private(&root->fs_info->extent_ins,
+ bytenr, (unsigned long)extent_op);
+ }
+ mutex_unlock(&root->fs_info->extent_ins_mutex);
+ return 0;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ ret = lookup_extent_backref(trans, extent_root, path,
+ bytenr, orig_parent, orig_root,
+ orig_generation, owner_objectid, 1);
+ if (ret)
+ goto out;
+ ret = remove_extent_backref(trans, extent_root, path);
+ if (ret)
+ goto out;
+ ret = insert_extent_backref(trans, extent_root, path, bytenr,
+ parent, ref_root, ref_generation,
+ owner_objectid);
+ BUG_ON(ret);
+ finish_current_insert(trans, extent_root, 0);
+ del_pending_extents(trans, extent_root, 0);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 orig_parent, u64 parent,
+ u64 ref_root, u64 ref_generation,
+ u64 owner_objectid)
+{
+ int ret;
+ if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
+ owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
+ return 0;
+ ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
+ parent, ref_root, ref_root,
+ ref_generation, ref_generation,
+ owner_objectid);
+ return ret;
+}
+
+static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 orig_parent, u64 parent,
+ u64 orig_root, u64 ref_root,
+ u64 orig_generation, u64 ref_generation,
+ u64 owner_objectid)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct btrfs_key key;
+ struct extent_buffer *l;
+ struct btrfs_extent_item *item;
+ u32 refs;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = 1;
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
+ 0, 1);
+ if (ret < 0)
+ return ret;
+ BUG_ON(ret == 0 || path->slots[0] == 0);
+
+ path->slots[0]--;
+ l = path->nodes[0];
+
+ btrfs_item_key_to_cpu(l, &key, path->slots[0]);
+ if (key.objectid != bytenr) {
+ btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]);
+ printk("wanted %Lu found %Lu\n", bytenr, key.objectid);
+ BUG();
+ }
+ BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
+
+ item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
+ refs = btrfs_extent_refs(l, item);
+ btrfs_set_extent_refs(l, item, refs + 1);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
+ btrfs_release_path(root->fs_info->extent_root, path);
+
+ path->reada = 1;
+ ret = insert_extent_backref(trans, root->fs_info->extent_root,
+ path, bytenr, parent,
+ ref_root, ref_generation,
+ owner_objectid);
+ BUG_ON(ret);
+ finish_current_insert(trans, root->fs_info->extent_root, 0);
+ del_pending_extents(trans, root->fs_info->extent_root, 0);
+
+ btrfs_free_path(path);
+ return 0;
+}
+
+int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 ref_root, u64 ref_generation,
+ u64 owner_objectid)
+{
+ int ret;
+ if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
+ owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
+ return 0;
+ ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
+ 0, ref_root, 0, ref_generation,
+ owner_objectid);
+ return ret;
+}
+
+int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ finish_current_insert(trans, root->fs_info->extent_root, 1);
+ del_pending_extents(trans, root->fs_info->extent_root, 1);
+ return 0;
+}
+
+int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 num_bytes, u32 *refs)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct btrfs_key key;
+ struct extent_buffer *l;
+ struct btrfs_extent_item *item;
+
+ WARN_ON(num_bytes < root->sectorsize);
+ path = btrfs_alloc_path();
+ path->reada = 1;
+ key.objectid = bytenr;
+ key.offset = num_bytes;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
+ ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
+ 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret != 0) {
+ btrfs_print_leaf(root, path->nodes[0]);
+ printk("failed to find block number %Lu\n", bytenr);
+ BUG();
+ }
+ l = path->nodes[0];
+ item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
+ *refs = btrfs_extent_refs(l, item);
+out:
+ btrfs_free_path(path);
+ return 0;
+}
+
+int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr)
+{
+ struct btrfs_root *extent_root = root->fs_info->extent_root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_extent_ref *ref_item;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u64 ref_root;
+ u64 last_snapshot;
+ u32 nritems;
+ int ret;
+
+ key.objectid = bytenr;
+ key.offset = (u64)-1;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+
+ path = btrfs_alloc_path();
+ ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ BUG_ON(ret == 0);
+
+ ret = -ENOENT;
+ if (path->slots[0] == 0)
+ goto out;
+
+ path->slots[0]--;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid != bytenr ||
+ found_key.type != BTRFS_EXTENT_ITEM_KEY)
+ goto out;
+
+ last_snapshot = btrfs_root_last_snapshot(&root->root_item);
+ while (1) {
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(extent_root, path);
+ if (ret < 0)
+ goto out;
+ if (ret == 0)
+ continue;
+ break;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != bytenr)
+ break;
+
+ if (found_key.type != BTRFS_EXTENT_REF_KEY) {
+ path->slots[0]++;
+ continue;
+ }
+
+ ref_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref);
+ ref_root = btrfs_ref_root(leaf, ref_item);
+ if (ref_root != root->root_key.objectid &&
+ ref_root != BTRFS_TREE_LOG_OBJECTID) {
+ ret = 1;
+ goto out;
+ }
+ if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) {
+ ret = 1;
+ goto out;
+ }
+
+ path->slots[0]++;
+ }
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *buf, u32 nr_extents)
+{
+ struct btrfs_key key;
+ struct btrfs_file_extent_item *fi;
+ u64 root_gen;
+ u32 nritems;
+ int i;
+ int level;
+ int ret = 0;
+ int shared = 0;
+
+ if (!root->ref_cows)
+ return 0;
+
+ if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
+ shared = 0;
+ root_gen = root->root_key.offset;
+ } else {
+ shared = 1;
+ root_gen = trans->transid - 1;
+ }
+
+ level = btrfs_header_level(buf);
+ nritems = btrfs_header_nritems(buf);
+
+ if (level == 0) {
+ struct btrfs_leaf_ref *ref;
+ struct btrfs_extent_info *info;
+
+ ref = btrfs_alloc_leaf_ref(root, nr_extents);
+ if (!ref) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ref->root_gen = root_gen;
+ ref->bytenr = buf->start;
+ ref->owner = btrfs_header_owner(buf);
+ ref->generation = btrfs_header_generation(buf);
+ ref->nritems = nr_extents;
+ info = ref->extents;
+
+ for (i = 0; nr_extents > 0 && i < nritems; i++) {
+ u64 disk_bytenr;
+ btrfs_item_key_to_cpu(buf, &key, i);
+ if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ fi = btrfs_item_ptr(buf, i,
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(buf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
+ if (disk_bytenr == 0)
+ continue;
+
+ info->bytenr = disk_bytenr;
+ info->num_bytes =
+ btrfs_file_extent_disk_num_bytes(buf, fi);
+ info->objectid = key.objectid;
+ info->offset = key.offset;
+ info++;
+ }
+
+ ret = btrfs_add_leaf_ref(root, ref, shared);
+ if (ret == -EEXIST && shared) {
+ struct btrfs_leaf_ref *old;
+ old = btrfs_lookup_leaf_ref(root, ref->bytenr);
+ BUG_ON(!old);
+ btrfs_remove_leaf_ref(root, old);
+ btrfs_free_leaf_ref(root, old);
+ ret = btrfs_add_leaf_ref(root, ref, shared);
+ }
+ WARN_ON(ret);
+ btrfs_free_leaf_ref(root, ref);
+ }
+out:
+ return ret;
+}
+
+int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *orig_buf, struct extent_buffer *buf,
+ u32 *nr_extents)
+{
+ u64 bytenr;
+ u64 ref_root;
+ u64 orig_root;
+ u64 ref_generation;
+ u64 orig_generation;
+ u32 nritems;
+ u32 nr_file_extents = 0;
+ struct btrfs_key key;
+ struct btrfs_file_extent_item *fi;
+ int i;
+ int level;
+ int ret = 0;
+ int faili = 0;
+ int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
+ u64, u64, u64, u64, u64, u64, u64, u64);
+
+ ref_root = btrfs_header_owner(buf);
+ ref_generation = btrfs_header_generation(buf);
+ orig_root = btrfs_header_owner(orig_buf);
+ orig_generation = btrfs_header_generation(orig_buf);
+
+ nritems = btrfs_header_nritems(buf);
+ level = btrfs_header_level(buf);
+
+ if (root->ref_cows) {
+ process_func = __btrfs_inc_extent_ref;
+ } else {
+ if (level == 0 &&
+ root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ goto out;
+ if (level != 0 &&
+ root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
+ goto out;
+ process_func = __btrfs_update_extent_ref;
+ }
+
+ for (i = 0; i < nritems; i++) {
+ cond_resched();
+ if (level == 0) {
+ btrfs_item_key_to_cpu(buf, &key, i);
+ if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ fi = btrfs_item_ptr(buf, i,
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(buf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
+ if (bytenr == 0)
+ continue;
+
+ nr_file_extents++;
+
+ ret = process_func(trans, root, bytenr,
+ orig_buf->start, buf->start,
+ orig_root, ref_root,
+ orig_generation, ref_generation,
+ key.objectid);
+
+ if (ret) {
+ faili = i;
+ WARN_ON(1);
+ goto fail;
+ }
+ } else {
+ bytenr = btrfs_node_blockptr(buf, i);
+ ret = process_func(trans, root, bytenr,
+ orig_buf->start, buf->start,
+ orig_root, ref_root,
+ orig_generation, ref_generation,
+ level - 1);
+ if (ret) {
+ faili = i;
+ WARN_ON(1);
+ goto fail;
+ }
+ }
+ }
+out:
+ if (nr_extents) {
+ if (level == 0)
+ *nr_extents = nr_file_extents;
+ else
+ *nr_extents = nritems;
+ }
+ return 0;
+fail:
+ WARN_ON(1);
+ return ret;
+}
+
+int btrfs_update_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *orig_buf,
+ struct extent_buffer *buf, int start_slot, int nr)
+
+{
+ u64 bytenr;
+ u64 ref_root;
+ u64 orig_root;
+ u64 ref_generation;
+ u64 orig_generation;
+ struct btrfs_key key;
+ struct btrfs_file_extent_item *fi;
+ int i;
+ int ret;
+ int slot;
+ int level;
+
+ BUG_ON(start_slot < 0);
+ BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
+
+ ref_root = btrfs_header_owner(buf);
+ ref_generation = btrfs_header_generation(buf);
+ orig_root = btrfs_header_owner(orig_buf);
+ orig_generation = btrfs_header_generation(orig_buf);
+ level = btrfs_header_level(buf);
+
+ if (!root->ref_cows) {
+ if (level == 0 &&
+ root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ return 0;
+ if (level != 0 &&
+ root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
+ return 0;
+ }
+
+ for (i = 0, slot = start_slot; i < nr; i++, slot++) {
+ cond_resched();
+ if (level == 0) {
+ btrfs_item_key_to_cpu(buf, &key, slot);
+ if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ fi = btrfs_item_ptr(buf, slot,
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(buf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
+ if (bytenr == 0)
+ continue;
+ ret = __btrfs_update_extent_ref(trans, root, bytenr,
+ orig_buf->start, buf->start,
+ orig_root, ref_root,
+ orig_generation, ref_generation,
+ key.objectid);
+ if (ret)
+ goto fail;
+ } else {
+ bytenr = btrfs_node_blockptr(buf, slot);
+ ret = __btrfs_update_extent_ref(trans, root, bytenr,
+ orig_buf->start, buf->start,
+ orig_root, ref_root,
+ orig_generation, ref_generation,
+ level - 1);
+ if (ret)
+ goto fail;
+ }
+ }
+ return 0;
+fail:
+ WARN_ON(1);
+ return -1;
+}
+
+static int write_one_cache_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_block_group_cache *cache)
+{
+ int ret;
+ int pending_ret;
+ struct btrfs_root *extent_root = root->fs_info->extent_root;
+ unsigned long bi;
+ struct extent_buffer *leaf;
+
+ ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
+ if (ret < 0)
+ goto fail;
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(extent_root, path);
+fail:
+ finish_current_insert(trans, extent_root, 0);
+ pending_ret = del_pending_extents(trans, extent_root, 0);
+ if (ret)
+ return ret;
+ if (pending_ret)
+ return pending_ret;
+ return 0;
+
+}
+
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_block_group_cache *cache, *entry;
+ struct rb_node *n;
+ int err = 0;
+ int werr = 0;
+ struct btrfs_path *path;
+ u64 last = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ while(1) {
+ cache = NULL;
+ spin_lock(&root->fs_info->block_group_cache_lock);
+ for (n = rb_first(&root->fs_info->block_group_cache_tree);
+ n; n = rb_next(n)) {
+ entry = rb_entry(n, struct btrfs_block_group_cache,
+ cache_node);
+ if (entry->dirty) {
+ cache = entry;
+ break;
+ }
+ }
+ spin_unlock(&root->fs_info->block_group_cache_lock);
+
+ if (!cache)
+ break;
+
+ cache->dirty = 0;
+ last += cache->key.offset;
+
+ err = write_one_cache_group(trans, root,
+ path, cache);
+ /*
+ * if we fail to write the cache group, we want
+ * to keep it marked dirty in hopes that a later
+ * write will work
+ */
+ if (err) {
+ werr = err;
+ continue;
+ }
+ }
+ btrfs_free_path(path);
+ return werr;
+}
+
+static int update_space_info(struct btrfs_fs_info *info, u64 flags,
+ u64 total_bytes, u64 bytes_used,
+ struct btrfs_space_info **space_info)
+{
+ struct btrfs_space_info *found;
+
+ found = __find_space_info(info, flags);
+ if (found) {
+ spin_lock(&found->lock);
+ found->total_bytes += total_bytes;
+ found->bytes_used += bytes_used;
+ found->full = 0;
+ spin_unlock(&found->lock);
+ *space_info = found;
+ return 0;
+ }
+ found = kzalloc(sizeof(*found), GFP_NOFS);
+ if (!found)
+ return -ENOMEM;
+
+ list_add(&found->list, &info->space_info);
+ INIT_LIST_HEAD(&found->block_groups);
+ init_rwsem(&found->groups_sem);
+ spin_lock_init(&found->lock);
+ found->flags = flags;
+ found->total_bytes = total_bytes;
+ found->bytes_used = bytes_used;
+ found->bytes_pinned = 0;
+ found->bytes_reserved = 0;
+ found->bytes_readonly = 0;
+ found->full = 0;
+ found->force_alloc = 0;
+ *space_info = found;
+ return 0;
+}
+
+static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+ u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_DUP);
+ if (extra_flags) {
+ if (flags & BTRFS_BLOCK_GROUP_DATA)
+ fs_info->avail_data_alloc_bits |= extra_flags;
+ if (flags & BTRFS_BLOCK_GROUP_METADATA)
+ fs_info->avail_metadata_alloc_bits |= extra_flags;
+ if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+ fs_info->avail_system_alloc_bits |= extra_flags;
+ }
+}
+
+static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
+{
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+ if (!cache->ro) {
+ cache->space_info->bytes_readonly += cache->key.offset -
+ btrfs_block_group_used(&cache->item);
+ cache->ro = 1;
+ }
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+}
+
+u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
+{
+ u64 num_devices = root->fs_info->fs_devices->rw_devices;
+
+ if (num_devices == 1)
+ flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
+ if (num_devices < 4)
+ flags &= ~BTRFS_BLOCK_GROUP_RAID10;
+
+ if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
+ (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))) {
+ flags &= ~BTRFS_BLOCK_GROUP_DUP;
+ }
+
+ if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
+ (flags & BTRFS_BLOCK_GROUP_RAID10)) {
+ flags &= ~BTRFS_BLOCK_GROUP_RAID1;
+ }
+
+ if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
+ ((flags & BTRFS_BLOCK_GROUP_RAID1) |
+ (flags & BTRFS_BLOCK_GROUP_RAID10) |
+ (flags & BTRFS_BLOCK_GROUP_DUP)))
+ flags &= ~BTRFS_BLOCK_GROUP_RAID0;
+ return flags;
+}
+
+static int do_chunk_alloc(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root, u64 alloc_bytes,
+ u64 flags, int force)
+{
+ struct btrfs_space_info *space_info;
+ u64 thresh;
+ int ret = 0;
+
+ mutex_lock(&extent_root->fs_info->chunk_mutex);
+
+ flags = btrfs_reduce_alloc_profile(extent_root, flags);
+
+ space_info = __find_space_info(extent_root->fs_info, flags);
+ if (!space_info) {
+ ret = update_space_info(extent_root->fs_info, flags,
+ 0, 0, &space_info);
+ BUG_ON(ret);
+ }
+ BUG_ON(!space_info);
+
+ spin_lock(&space_info->lock);
+ if (space_info->force_alloc) {
+ force = 1;
+ space_info->force_alloc = 0;
+ }
+ if (space_info->full) {
+ spin_unlock(&space_info->lock);
+ goto out;
+ }
+
+ thresh = space_info->total_bytes - space_info->bytes_readonly;
+ thresh = div_factor(thresh, 6);
+ if (!force &&
+ (space_info->bytes_used + space_info->bytes_pinned +
+ space_info->bytes_reserved + alloc_bytes) < thresh) {
+ spin_unlock(&space_info->lock);
+ goto out;
+ }
+ spin_unlock(&space_info->lock);
+
+ ret = btrfs_alloc_chunk(trans, extent_root, flags);
+ if (ret) {
+printk("space info full %Lu\n", flags);
+ space_info->full = 1;
+ }
+out:
+ mutex_unlock(&extent_root->fs_info->chunk_mutex);
+ return ret;
+}
+
+static int update_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, int alloc,
+ int mark_free)
+{
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_fs_info *info = root->fs_info;
+ u64 total = num_bytes;
+ u64 old_val;
+ u64 byte_in_group;
+
+ while(total) {
+ cache = btrfs_lookup_block_group(info, bytenr);
+ if (!cache)
+ return -1;
+ byte_in_group = bytenr - cache->key.objectid;
+ WARN_ON(byte_in_group > cache->key.offset);
+
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+ cache->dirty = 1;
+ old_val = btrfs_block_group_used(&cache->item);
+ num_bytes = min(total, cache->key.offset - byte_in_group);
+ if (alloc) {
+ old_val += num_bytes;
+ cache->space_info->bytes_used += num_bytes;
+ if (cache->ro) {
+ cache->space_info->bytes_readonly -= num_bytes;
+ WARN_ON(1);
+ }
+ btrfs_set_block_group_used(&cache->item, old_val);
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+ } else {
+ old_val -= num_bytes;
+ cache->space_info->bytes_used -= num_bytes;
+ if (cache->ro)
+ cache->space_info->bytes_readonly += num_bytes;
+ btrfs_set_block_group_used(&cache->item, old_val);
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+ if (mark_free) {
+ int ret;
+ ret = btrfs_add_free_space(cache, bytenr,
+ num_bytes);
+ if (ret)
+ return -1;
+ }
+ }
+ total -= num_bytes;
+ bytenr += num_bytes;
+ }
+ return 0;
+}
+
+static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
+ if (!cache)
+ return 0;
+
+ return cache->key.objectid;
+}
+
+int btrfs_update_pinned_extents(struct btrfs_root *root,
+ u64 bytenr, u64 num, int pin)
+{
+ u64 len;
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex));
+ if (pin) {
+ set_extent_dirty(&fs_info->pinned_extents,
+ bytenr, bytenr + num - 1, GFP_NOFS);
+ } else {
+ clear_extent_dirty(&fs_info->pinned_extents,
+ bytenr, bytenr + num - 1, GFP_NOFS);
+ }
+ while (num > 0) {
+ cache = btrfs_lookup_block_group(fs_info, bytenr);
+ BUG_ON(!cache);
+ len = min(num, cache->key.offset -
+ (bytenr - cache->key.objectid));
+ if (pin) {
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+ cache->pinned += len;
+ cache->space_info->bytes_pinned += len;
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+ fs_info->total_pinned += len;
+ } else {
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+ cache->pinned -= len;
+ cache->space_info->bytes_pinned -= len;
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+ fs_info->total_pinned -= len;
+ if (cache->cached)
+ btrfs_add_free_space(cache, bytenr, len);
+ }
+ bytenr += len;
+ num -= len;
+ }
+ return 0;
+}
+
+static int update_reserved_extents(struct btrfs_root *root,
+ u64 bytenr, u64 num, int reserve)
+{
+ u64 len;
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ while (num > 0) {
+ cache = btrfs_lookup_block_group(fs_info, bytenr);
+ BUG_ON(!cache);
+ len = min(num, cache->key.offset -
+ (bytenr - cache->key.objectid));
+
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+ if (reserve) {
+ cache->reserved += len;
+ cache->space_info->bytes_reserved += len;
+ } else {
+ cache->reserved -= len;
+ cache->space_info->bytes_reserved -= len;
+ }
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+ bytenr += len;
+ num -= len;
+ }
+ return 0;
+}
+
+int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
+{
+ u64 last = 0;
+ u64 start;
+ u64 end;
+ struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
+ int ret;
+
+ mutex_lock(&root->fs_info->pinned_mutex);
+ while(1) {
+ ret = find_first_extent_bit(pinned_extents, last,
+ &start, &end, EXTENT_DIRTY);
+ if (ret)
+ break;
+ set_extent_dirty(copy, start, end, GFP_NOFS);
+ last = end + 1;
+ }
+ mutex_unlock(&root->fs_info->pinned_mutex);
+ return 0;
+}
+
+int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_io_tree *unpin)
+{
+ u64 start;
+ u64 end;
+ int ret;
+
+ mutex_lock(&root->fs_info->pinned_mutex);
+ while(1) {
+ ret = find_first_extent_bit(unpin, 0, &start, &end,
+ EXTENT_DIRTY);
+ if (ret)
+ break;
+ btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
+ clear_extent_dirty(unpin, start, end, GFP_NOFS);
+ if (need_resched()) {
+ mutex_unlock(&root->fs_info->pinned_mutex);
+ cond_resched();
+ mutex_lock(&root->fs_info->pinned_mutex);
+ }
+ }
+ mutex_unlock(&root->fs_info->pinned_mutex);
+ return 0;
+}
+
+static int finish_current_insert(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root, int all)
+{
+ u64 start;
+ u64 end;
+ u64 priv;
+ u64 search = 0;
+ u64 skipped = 0;
+ struct btrfs_fs_info *info = extent_root->fs_info;
+ struct btrfs_path *path;
+ struct pending_extent_op *extent_op, *tmp;
+ struct list_head insert_list, update_list;
+ int ret;
+ int num_inserts = 0, max_inserts;
+
+ path = btrfs_alloc_path();
+ INIT_LIST_HEAD(&insert_list);
+ INIT_LIST_HEAD(&update_list);
+
+ max_inserts = extent_root->leafsize /
+ (2 * sizeof(struct btrfs_key) + 2 * sizeof(struct btrfs_item) +
+ sizeof(struct btrfs_extent_ref) +
+ sizeof(struct btrfs_extent_item));
+again:
+ mutex_lock(&info->extent_ins_mutex);
+ while (1) {
+ ret = find_first_extent_bit(&info->extent_ins, search, &start,
+ &end, EXTENT_WRITEBACK);
+ if (ret) {
+ if (skipped && all && !num_inserts) {
+ skipped = 0;
+ search = 0;
+ continue;
+ }
+ mutex_unlock(&info->extent_ins_mutex);
+ break;
+ }
+
+ ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
+ if (!ret) {
+ skipped = 1;
+ search = end + 1;
+ if (need_resched()) {
+ mutex_unlock(&info->extent_ins_mutex);
+ cond_resched();
+ mutex_lock(&info->extent_ins_mutex);
+ }
+ continue;
+ }
+
+ ret = get_state_private(&info->extent_ins, start, &priv);
+ BUG_ON(ret);
+ extent_op = (struct pending_extent_op *)(unsigned long) priv;
+
+ if (extent_op->type == PENDING_EXTENT_INSERT) {
+ num_inserts++;
+ list_add_tail(&extent_op->list, &insert_list);
+ search = end + 1;
+ if (num_inserts == max_inserts) {
+ mutex_unlock(&info->extent_ins_mutex);
+ break;
+ }
+ } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
+ list_add_tail(&extent_op->list, &update_list);
+ search = end + 1;
+ } else {
+ BUG();
+ }
+ }
+
+ /*
+ * process the update list, clear the writeback bit for it, and if
+ * somebody marked this thing for deletion then just unlock it and be
+ * done, the free_extents will handle it
+ */
+ mutex_lock(&info->extent_ins_mutex);
+ list_for_each_entry_safe(extent_op, tmp, &update_list, list) {
+ clear_extent_bits(&info->extent_ins, extent_op->bytenr,
+ extent_op->bytenr + extent_op->num_bytes - 1,
+ EXTENT_WRITEBACK, GFP_NOFS);
+ if (extent_op->del) {
+ list_del_init(&extent_op->list);
+ unlock_extent(&info->extent_ins, extent_op->bytenr,
+ extent_op->bytenr + extent_op->num_bytes
+ - 1, GFP_NOFS);
+ kfree(extent_op);
+ }
+ }
+ mutex_unlock(&info->extent_ins_mutex);
+
+ /*
+ * still have things left on the update list, go ahead an update
+ * everything
+ */
+ if (!list_empty(&update_list)) {
+ ret = update_backrefs(trans, extent_root, path, &update_list);
+ BUG_ON(ret);
+ }
+
+ /*
+ * if no inserts need to be done, but we skipped some extents and we
+ * need to make sure everything is cleaned then reset everything and
+ * go back to the beginning
+ */
+ if (!num_inserts && all && skipped) {
+ search = 0;
+ skipped = 0;
+ INIT_LIST_HEAD(&update_list);
+ INIT_LIST_HEAD(&insert_list);
+ goto again;
+ } else if (!num_inserts) {
+ goto out;
+ }
+
+ /*
+ * process the insert extents list. Again if we are deleting this
+ * extent, then just unlock it, pin down the bytes if need be, and be
+ * done with it. Saves us from having to actually insert the extent
+ * into the tree and then subsequently come along and delete it
+ */
+ mutex_lock(&info->extent_ins_mutex);
+ list_for_each_entry_safe(extent_op, tmp, &insert_list, list) {
+ clear_extent_bits(&info->extent_ins, extent_op->bytenr,
+ extent_op->bytenr + extent_op->num_bytes - 1,
+ EXTENT_WRITEBACK, GFP_NOFS);
+ if (extent_op->del) {
+ list_del_init(&extent_op->list);
+ unlock_extent(&info->extent_ins, extent_op->bytenr,
+ extent_op->bytenr + extent_op->num_bytes
+ - 1, GFP_NOFS);
+
+ mutex_lock(&extent_root->fs_info->pinned_mutex);
+ ret = pin_down_bytes(trans, extent_root,
+ extent_op->bytenr,
+ extent_op->num_bytes, 0);
+ mutex_unlock(&extent_root->fs_info->pinned_mutex);
+
+ ret = update_block_group(trans, extent_root,
+ extent_op->bytenr,
+ extent_op->num_bytes,
+ 0, ret > 0);
+ BUG_ON(ret);
+ kfree(extent_op);
+ num_inserts--;
+ }
+ }
+ mutex_unlock(&info->extent_ins_mutex);
+
+ ret = insert_extents(trans, extent_root, path, &insert_list,
+ num_inserts);
+ BUG_ON(ret);
+
+ /*
+ * if we broke out of the loop in order to insert stuff because we hit
+ * the maximum number of inserts at a time we can handle, then loop
+ * back and pick up where we left off
+ */
+ if (num_inserts == max_inserts) {
+ INIT_LIST_HEAD(&insert_list);
+ INIT_LIST_HEAD(&update_list);
+ num_inserts = 0;
+ goto again;
+ }
+
+ /*
+ * again, if we need to make absolutely sure there are no more pending
+ * extent operations left and we know that we skipped some, go back to
+ * the beginning and do it all again
+ */
+ if (all && skipped) {
+ INIT_LIST_HEAD(&insert_list);
+ INIT_LIST_HEAD(&update_list);
+ search = 0;
+ skipped = 0;
+ num_inserts = 0;
+ goto again;
+ }
+out:
+ btrfs_free_path(path);
+ return 0;
+}
+
+static int pin_down_bytes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, int is_data)
+{
+ int err = 0;
+ struct extent_buffer *buf;
+
+ if (is_data)
+ goto pinit;
+
+ buf = btrfs_find_tree_block(root, bytenr, num_bytes);
+ if (!buf)
+ goto pinit;
+
+ /* we can reuse a block if it hasn't been written
+ * and it is from this transaction. We can't
+ * reuse anything from the tree log root because
+ * it has tiny sub-transactions.
+ */
+ if (btrfs_buffer_uptodate(buf, 0) &&
+ btrfs_try_tree_lock(buf)) {
+ u64 header_owner = btrfs_header_owner(buf);
+ u64 header_transid = btrfs_header_generation(buf);
+ if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
+ header_owner != BTRFS_TREE_RELOC_OBJECTID &&
+ header_transid == trans->transid &&
+ !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
+ clean_tree_block(NULL, root, buf);
+ btrfs_tree_unlock(buf);
+ free_extent_buffer(buf);
+ return 1;
+ }
+ btrfs_tree_unlock(buf);
+ }
+ free_extent_buffer(buf);
+pinit:
+ btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
+
+ BUG_ON(err < 0);
+ return 0;
+}
+
+/*
+ * remove an extent from the root, returns 0 on success
+ */
+static int __free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner_objectid, int pin, int mark_free)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_fs_info *info = root->fs_info;
+ struct btrfs_root *extent_root = info->extent_root;
+ struct extent_buffer *leaf;
+ int ret;
+ int extent_slot = 0;
+ int found_extent = 0;
+ int num_to_del = 1;
+ struct btrfs_extent_item *ei;
+ u32 refs;
+
+ key.objectid = bytenr;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
+ key.offset = num_bytes;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = 1;
+ ret = lookup_extent_backref(trans, extent_root, path,
+ bytenr, parent, root_objectid,
+ ref_generation, owner_objectid, 1);
+ if (ret == 0) {
+ struct btrfs_key found_key;
+ extent_slot = path->slots[0];
+ while(extent_slot > 0) {
+ extent_slot--;
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ extent_slot);
+ if (found_key.objectid != bytenr)
+ break;
+ if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
+ found_key.offset == num_bytes) {
+ found_extent = 1;
+ break;
+ }
+ if (path->slots[0] - extent_slot > 5)
+ break;
+ }
+ if (!found_extent) {
+ ret = remove_extent_backref(trans, extent_root, path);
+ BUG_ON(ret);
+ btrfs_release_path(extent_root, path);
+ ret = btrfs_search_slot(trans, extent_root,
+ &key, path, -1, 1);
+ if (ret) {
+ printk(KERN_ERR "umm, got %d back from search"
+ ", was looking for %Lu\n", ret,
+ bytenr);
+ btrfs_print_leaf(extent_root, path->nodes[0]);
+ }
+ BUG_ON(ret);
+ extent_slot = path->slots[0];
+ }
+ } else {
+ btrfs_print_leaf(extent_root, path->nodes[0]);
+ WARN_ON(1);
+ printk("Unable to find ref byte nr %Lu root %Lu "
+ "gen %Lu owner %Lu\n", bytenr,
+ root_objectid, ref_generation, owner_objectid);
+ }
+
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, extent_slot,
+ struct btrfs_extent_item);
+ refs = btrfs_extent_refs(leaf, ei);
+ BUG_ON(refs == 0);
+ refs -= 1;
+ btrfs_set_extent_refs(leaf, ei, refs);
+
+ btrfs_mark_buffer_dirty(leaf);
+
+ if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
+ struct btrfs_extent_ref *ref;
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref);
+ BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
+ /* if the back ref and the extent are next to each other
+ * they get deleted below in one shot
+ */
+ path->slots[0] = extent_slot;
+ num_to_del = 2;
+ } else if (found_extent) {
+ /* otherwise delete the extent back ref */
+ ret = remove_extent_backref(trans, extent_root, path);
+ BUG_ON(ret);
+ /* if refs are 0, we need to setup the path for deletion */
+ if (refs == 0) {
+ btrfs_release_path(extent_root, path);
+ ret = btrfs_search_slot(trans, extent_root, &key, path,
+ -1, 1);
+ BUG_ON(ret);
+ }
+ }
+
+ if (refs == 0) {
+ u64 super_used;
+ u64 root_used;
+#ifdef BIO_RW_DISCARD
+ u64 map_length = num_bytes;
+ struct btrfs_multi_bio *multi = NULL;
+#endif
+
+ if (pin) {
+ mutex_lock(&root->fs_info->pinned_mutex);
+ ret = pin_down_bytes(trans, root, bytenr, num_bytes,
+ owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
+ mutex_unlock(&root->fs_info->pinned_mutex);
+ if (ret > 0)
+ mark_free = 1;
+ BUG_ON(ret < 0);
+ }
+
+ /* block accounting for super block */
+ spin_lock_irq(&info->delalloc_lock);
+ super_used = btrfs_super_bytes_used(&info->super_copy);
+ btrfs_set_super_bytes_used(&info->super_copy,
+ super_used - num_bytes);
+ spin_unlock_irq(&info->delalloc_lock);
+
+ /* block accounting for root item */
+ root_used = btrfs_root_used(&root->root_item);
+ btrfs_set_root_used(&root->root_item,
+ root_used - num_bytes);
+ ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
+ num_to_del);
+ BUG_ON(ret);
+ btrfs_release_path(extent_root, path);
+ ret = update_block_group(trans, root, bytenr, num_bytes, 0,
+ mark_free);
+ BUG_ON(ret);
+
+#ifdef BIO_RW_DISCARD
+ /* Tell the block device(s) that the sectors can be discarded */
+ ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
+ bytenr, &map_length, &multi, 0);
+ if (!ret) {
+ struct btrfs_bio_stripe *stripe = multi->stripes;
+ int i;
+
+ if (map_length > num_bytes)
+ map_length = num_bytes;
+
+ for (i = 0; i < multi->num_stripes; i++, stripe++) {
+ blkdev_issue_discard(stripe->dev->bdev,
+ stripe->physical >> 9,
+ map_length >> 9);
+ }
+ kfree(multi);
+ }
+#endif
+ }
+ btrfs_free_path(path);
+ finish_current_insert(trans, extent_root, 0);
+ return ret;
+}
+
+/*
+ * find all the blocks marked as pending in the radix tree and remove
+ * them from the extent map
+ */
+static int del_pending_extents(struct btrfs_trans_handle *trans, struct
+ btrfs_root *extent_root, int all)
+{
+ int ret;
+ int err = 0;
+ u64 start;
+ u64 end;
+ u64 priv;
+ u64 search = 0;
+ int nr = 0, skipped = 0;
+ struct extent_io_tree *pending_del;
+ struct extent_io_tree *extent_ins;
+ struct pending_extent_op *extent_op;
+ struct btrfs_fs_info *info = extent_root->fs_info;
+ struct list_head delete_list;
+
+ INIT_LIST_HEAD(&delete_list);
+ extent_ins = &extent_root->fs_info->extent_ins;
+ pending_del = &extent_root->fs_info->pending_del;
+
+again:
+ mutex_lock(&info->extent_ins_mutex);
+ while(1) {
+ ret = find_first_extent_bit(pending_del, search, &start, &end,
+ EXTENT_WRITEBACK);
+ if (ret) {
+ if (all && skipped && !nr) {
+ search = 0;
+ continue;
+ }
+ mutex_unlock(&info->extent_ins_mutex);
+ break;
+ }
+
+ ret = try_lock_extent(extent_ins, start, end, GFP_NOFS);
+ if (!ret) {
+ search = end+1;
+ skipped = 1;
+
+ if (need_resched()) {
+ mutex_unlock(&info->extent_ins_mutex);
+ cond_resched();
+ mutex_lock(&info->extent_ins_mutex);
+ }
+
+ continue;
+ }
+ BUG_ON(ret < 0);
+
+ ret = get_state_private(pending_del, start, &priv);
+ BUG_ON(ret);
+ extent_op = (struct pending_extent_op *)(unsigned long)priv;
+
+ clear_extent_bits(pending_del, start, end, EXTENT_WRITEBACK,
+ GFP_NOFS);
+ if (!test_range_bit(extent_ins, start, end,
+ EXTENT_WRITEBACK, 0)) {
+ list_add_tail(&extent_op->list, &delete_list);
+ nr++;
+ } else {
+ kfree(extent_op);
+
+ ret = get_state_private(&info->extent_ins, start,
+ &priv);
+ BUG_ON(ret);
+ extent_op = (struct pending_extent_op *)
+ (unsigned long)priv;
+
+ clear_extent_bits(&info->extent_ins, start, end,
+ EXTENT_WRITEBACK, GFP_NOFS);
+
+ if (extent_op->type == PENDING_BACKREF_UPDATE) {
+ list_add_tail(&extent_op->list, &delete_list);
+ search = end + 1;
+ nr++;
+ continue;
+ }
+
+ mutex_lock(&extent_root->fs_info->pinned_mutex);
+ ret = pin_down_bytes(trans, extent_root, start,
+ end + 1 - start, 0);
+ mutex_unlock(&extent_root->fs_info->pinned_mutex);
+
+ ret = update_block_group(trans, extent_root, start,
+ end + 1 - start, 0, ret > 0);
+
+ unlock_extent(extent_ins, start, end, GFP_NOFS);
+ BUG_ON(ret);
+ kfree(extent_op);
+ }
+ if (ret)
+ err = ret;
+
+ search = end + 1;
+
+ if (need_resched()) {
+ mutex_unlock(&info->extent_ins_mutex);
+ cond_resched();
+ mutex_lock(&info->extent_ins_mutex);
+ }
+ }
+
+ if (nr) {
+ ret = free_extents(trans, extent_root, &delete_list);
+ BUG_ON(ret);
+ }
+
+ if (all && skipped) {
+ INIT_LIST_HEAD(&delete_list);
+ search = 0;
+ nr = 0;
+ goto again;
+ }
+
+ return err;
+}
+
+/*
+ * remove an extent from the root, returns 0 on success
+ */
+static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner_objectid, int pin)
+{
+ struct btrfs_root *extent_root = root->fs_info->extent_root;
+ int pending_ret;
+ int ret;
+
+ WARN_ON(num_bytes < root->sectorsize);
+ if (root == extent_root) {
+ struct pending_extent_op *extent_op = NULL;
+
+ mutex_lock(&root->fs_info->extent_ins_mutex);
+ if (test_range_bit(&root->fs_info->extent_ins, bytenr,
+ bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
+ u64 priv;
+ ret = get_state_private(&root->fs_info->extent_ins,
+ bytenr, &priv);
+ BUG_ON(ret);
+ extent_op = (struct pending_extent_op *)
+ (unsigned long)priv;
+
+ extent_op->del = 1;
+ if (extent_op->type == PENDING_EXTENT_INSERT) {
+ mutex_unlock(&root->fs_info->extent_ins_mutex);
+ return 0;
+ }
+ }
+
+ if (extent_op) {
+ ref_generation = extent_op->orig_generation;
+ parent = extent_op->orig_parent;
+ }
+
+ extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
+ BUG_ON(!extent_op);
+
+ extent_op->type = PENDING_EXTENT_DELETE;
+ extent_op->bytenr = bytenr;
+ extent_op->num_bytes = num_bytes;
+ extent_op->parent = parent;
+ extent_op->orig_parent = parent;
+ extent_op->generation = ref_generation;
+ extent_op->orig_generation = ref_generation;
+ extent_op->level = (int)owner_objectid;
+ INIT_LIST_HEAD(&extent_op->list);
+ extent_op->del = 0;
+
+ set_extent_bits(&root->fs_info->pending_del,
+ bytenr, bytenr + num_bytes - 1,
+ EXTENT_WRITEBACK, GFP_NOFS);
+ set_state_private(&root->fs_info->pending_del,
+ bytenr, (unsigned long)extent_op);
+ mutex_unlock(&root->fs_info->extent_ins_mutex);
+ return 0;
+ }
+ /* if metadata always pin */
+ if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
+ if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+ struct btrfs_block_group_cache *cache;
+
+ /* btrfs_free_reserved_extent */
+ cache = btrfs_lookup_block_group(root->fs_info, bytenr);
+ BUG_ON(!cache);
+ btrfs_add_free_space(cache, bytenr, num_bytes);
+ update_reserved_extents(root, bytenr, num_bytes, 0);
+ return 0;
+ }
+ pin = 1;
+ }
+
+ /* if data pin when any transaction has committed this */
+ if (ref_generation != trans->transid)
+ pin = 1;
+
+ ret = __free_extent(trans, root, bytenr, num_bytes, parent,
+ root_objectid, ref_generation,
+ owner_objectid, pin, pin == 0);
+
+ finish_current_insert(trans, root->fs_info->extent_root, 0);
+ pending_ret = del_pending_extents(trans, root->fs_info->extent_root, 0);
+ return ret ? ret : pending_ret;
+}
+
+int btrfs_free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner_objectid, int pin)
+{
+ int ret;
+
+ ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
+ root_objectid, ref_generation,
+ owner_objectid, pin);
+ return ret;
+}
+
+static u64 stripe_align(struct btrfs_root *root, u64 val)
+{
+ u64 mask = ((u64)root->stripesize - 1);
+ u64 ret = (val + mask) & ~mask;
+ return ret;
+}
+
+/*
+ * walks the btree of allocated extents and find a hole of a given size.
+ * The key ins is changed to record the hole:
+ * ins->objectid == block start
+ * ins->flags = BTRFS_EXTENT_ITEM_KEY
+ * ins->offset == number of blocks
+ * Any available blocks before search_start are skipped.
+ */
+static int noinline find_free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *orig_root,
+ u64 num_bytes, u64 empty_size,
+ u64 search_start, u64 search_end,
+ u64 hint_byte, struct btrfs_key *ins,
+ u64 exclude_start, u64 exclude_nr,
+ int data)
+{
+ int ret = 0;
+ struct btrfs_root * root = orig_root->fs_info->extent_root;
+ u64 total_needed = num_bytes;
+ u64 *last_ptr = NULL;
+ u64 last_wanted = 0;
+ struct btrfs_block_group_cache *block_group = NULL;
+ int chunk_alloc_done = 0;
+ int empty_cluster = 2 * 1024 * 1024;
+ int allowed_chunk_alloc = 0;
+ struct list_head *head = NULL, *cur = NULL;
+ int loop = 0;
+ int extra_loop = 0;
+ struct btrfs_space_info *space_info;
+
+ WARN_ON(num_bytes < root->sectorsize);
+ btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
+ ins->objectid = 0;
+ ins->offset = 0;
+
+ if (orig_root->ref_cows || empty_size)
+ allowed_chunk_alloc = 1;
+
+ if (data & BTRFS_BLOCK_GROUP_METADATA) {
+ last_ptr = &root->fs_info->last_alloc;
+ empty_cluster = 64 * 1024;
+ }
+
+ if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
+ last_ptr = &root->fs_info->last_data_alloc;
+
+ if (last_ptr) {
+ if (*last_ptr) {
+ hint_byte = *last_ptr;
+ last_wanted = *last_ptr;
+ } else
+ empty_size += empty_cluster;
+ } else {
+ empty_cluster = 0;
+ }
+ search_start = max(search_start, first_logical_byte(root, 0));
+ search_start = max(search_start, hint_byte);
+
+ if (last_wanted && search_start != last_wanted) {
+ last_wanted = 0;
+ empty_size += empty_cluster;
+ }
+
+ total_needed += empty_size;
+ block_group = btrfs_lookup_block_group(root->fs_info, search_start);
+ if (!block_group)
+ block_group = btrfs_lookup_first_block_group(root->fs_info,
+ search_start);
+ space_info = __find_space_info(root->fs_info, data);
+
+ down_read(&space_info->groups_sem);
+ while (1) {
+ struct btrfs_free_space *free_space;
+ /*
+ * the only way this happens if our hint points to a block
+ * group thats not of the proper type, while looping this
+ * should never happen
+ */
+ if (empty_size)
+ extra_loop = 1;
+
+ if (!block_group)
+ goto new_group_no_lock;
+
+ mutex_lock(&block_group->alloc_mutex);
+ if (unlikely(!block_group_bits(block_group, data)))
+ goto new_group;
+
+ ret = cache_block_group(root, block_group);
+ if (ret) {
+ mutex_unlock(&block_group->alloc_mutex);
+ break;
+ }
+
+ if (block_group->ro)
+ goto new_group;
+
+ free_space = btrfs_find_free_space(block_group, search_start,
+ total_needed);
+ if (free_space) {
+ u64 start = block_group->key.objectid;
+ u64 end = block_group->key.objectid +
+ block_group->key.offset;
+
+ search_start = stripe_align(root, free_space->offset);
+
+ /* move on to the next group */
+ if (search_start + num_bytes >= search_end)
+ goto new_group;
+
+ /* move on to the next group */
+ if (search_start + num_bytes > end)
+ goto new_group;
+
+ if (last_wanted && search_start != last_wanted) {
+ total_needed += empty_cluster;
+ empty_size += empty_cluster;
+ last_wanted = 0;
+ /*
+ * if search_start is still in this block group
+ * then we just re-search this block group
+ */
+ if (search_start >= start &&
+ search_start < end) {
+ mutex_unlock(&block_group->alloc_mutex);
+ continue;
+ }
+
+ /* else we go to the next block group */
+ goto new_group;
+ }
+
+ if (exclude_nr > 0 &&
+ (search_start + num_bytes > exclude_start &&
+ search_start < exclude_start + exclude_nr)) {
+ search_start = exclude_start + exclude_nr;
+ /*
+ * if search_start is still in this block group
+ * then we just re-search this block group
+ */
+ if (search_start >= start &&
+ search_start < end) {
+ mutex_unlock(&block_group->alloc_mutex);
+ last_wanted = 0;
+ continue;
+ }
+
+ /* else we go to the next block group */
+ goto new_group;
+ }
+
+ ins->objectid = search_start;
+ ins->offset = num_bytes;
+
+ btrfs_remove_free_space_lock(block_group, search_start,
+ num_bytes);
+ /* we are all good, lets return */
+ mutex_unlock(&block_group->alloc_mutex);
+ break;
+ }
+new_group:
+ mutex_unlock(&block_group->alloc_mutex);
+new_group_no_lock:
+ /* don't try to compare new allocations against the
+ * last allocation any more
+ */
+ last_wanted = 0;
+
+ /*
+ * Here's how this works.
+ * loop == 0: we were searching a block group via a hint
+ * and didn't find anything, so we start at
+ * the head of the block groups and keep searching
+ * loop == 1: we're searching through all of the block groups
+ * if we hit the head again we have searched
+ * all of the block groups for this space and we
+ * need to try and allocate, if we cant error out.
+ * loop == 2: we allocated more space and are looping through
+ * all of the block groups again.
+ */
+ if (loop == 0) {
+ head = &space_info->block_groups;
+ cur = head->next;
+ loop++;
+ } else if (loop == 1 && cur == head) {
+ int keep_going;
+
+ /* at this point we give up on the empty_size
+ * allocations and just try to allocate the min
+ * space.
+ *
+ * The extra_loop field was set if an empty_size
+ * allocation was attempted above, and if this
+ * is try we need to try the loop again without
+ * the additional empty_size.
+ */
+ total_needed -= empty_size;
+ empty_size = 0;
+ keep_going = extra_loop;
+ loop++;
+
+ if (allowed_chunk_alloc && !chunk_alloc_done) {
+ up_read(&space_info->groups_sem);
+ ret = do_chunk_alloc(trans, root, num_bytes +
+ 2 * 1024 * 1024, data, 1);
+ down_read(&space_info->groups_sem);
+ if (ret < 0)
+ goto loop_check;
+ head = &space_info->block_groups;
+ /*
+ * we've allocated a new chunk, keep
+ * trying
+ */
+ keep_going = 1;
+ chunk_alloc_done = 1;
+ } else if (!allowed_chunk_alloc) {
+ space_info->force_alloc = 1;
+ }
+loop_check:
+ if (keep_going) {
+ cur = head->next;
+ extra_loop = 0;
+ } else {
+ break;
+ }
+ } else if (cur == head) {
+ break;
+ }
+
+ block_group = list_entry(cur, struct btrfs_block_group_cache,
+ list);
+ search_start = block_group->key.objectid;
+ cur = cur->next;
+ }
+
+ /* we found what we needed */
+ if (ins->objectid) {
+ if (!(data & BTRFS_BLOCK_GROUP_DATA))
+ trans->block_group = block_group;
+
+ if (last_ptr)
+ *last_ptr = ins->objectid + ins->offset;
+ ret = 0;
+ } else if (!ret) {
+ printk(KERN_ERR "we were searching for %Lu bytes, num_bytes %Lu,"
+ " loop %d, allowed_alloc %d\n", total_needed, num_bytes,
+ loop, allowed_chunk_alloc);
+ ret = -ENOSPC;
+ }
+
+ up_read(&space_info->groups_sem);
+ return ret;
+}
+
+static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
+{
+ struct btrfs_block_group_cache *cache;
+ struct list_head *l;
+
+ printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
+ info->total_bytes - info->bytes_used - info->bytes_pinned -
+ info->bytes_reserved, (info->full) ? "" : "not ");
+
+ down_read(&info->groups_sem);
+ list_for_each(l, &info->block_groups) {
+ cache = list_entry(l, struct btrfs_block_group_cache, list);
+ spin_lock(&cache->lock);
+ printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
+ "%Lu pinned %Lu reserved\n",
+ cache->key.objectid, cache->key.offset,
+ btrfs_block_group_used(&cache->item),
+ cache->pinned, cache->reserved);
+ btrfs_dump_free_space(cache, bytes);
+ spin_unlock(&cache->lock);
+ }
+ up_read(&info->groups_sem);
+}
+
+static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 num_bytes, u64 min_alloc_size,
+ u64 empty_size, u64 hint_byte,
+ u64 search_end, struct btrfs_key *ins,
+ u64 data)
+{
+ int ret;
+ u64 search_start = 0;
+ u64 alloc_profile;
+ struct btrfs_fs_info *info = root->fs_info;
+
+ if (data) {
+ alloc_profile = info->avail_data_alloc_bits &
+ info->data_alloc_profile;
+ data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
+ } else if (root == root->fs_info->chunk_root) {
+ alloc_profile = info->avail_system_alloc_bits &
+ info->system_alloc_profile;
+ data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
+ } else {
+ alloc_profile = info->avail_metadata_alloc_bits &
+ info->metadata_alloc_profile;
+ data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
+ }
+again:
+ data = btrfs_reduce_alloc_profile(root, data);
+ /*
+ * the only place that sets empty_size is btrfs_realloc_node, which
+ * is not called recursively on allocations
+ */
+ if (empty_size || root->ref_cows) {
+ if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
+ ret = do_chunk_alloc(trans, root->fs_info->extent_root,
+ 2 * 1024 * 1024,
+ BTRFS_BLOCK_GROUP_METADATA |
+ (info->metadata_alloc_profile &
+ info->avail_metadata_alloc_bits), 0);
+ }
+ ret = do_chunk_alloc(trans, root->fs_info->extent_root,
+ num_bytes + 2 * 1024 * 1024, data, 0);
+ }
+
+ WARN_ON(num_bytes < root->sectorsize);
+ ret = find_free_extent(trans, root, num_bytes, empty_size,
+ search_start, search_end, hint_byte, ins,
+ trans->alloc_exclude_start,
+ trans->alloc_exclude_nr, data);
+
+ if (ret == -ENOSPC && num_bytes > min_alloc_size) {
+ num_bytes = num_bytes >> 1;
+ num_bytes = num_bytes & ~(root->sectorsize - 1);
+ num_bytes = max(num_bytes, min_alloc_size);
+ do_chunk_alloc(trans, root->fs_info->extent_root,
+ num_bytes, data, 1);
+ goto again;
+ }
+ if (ret) {
+ struct btrfs_space_info *sinfo;
+
+ sinfo = __find_space_info(root->fs_info, data);
+ printk("allocation failed flags %Lu, wanted %Lu\n",
+ data, num_bytes);
+ dump_space_info(sinfo, num_bytes);
+ BUG();
+ }
+
+ return ret;
+}
+
+int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = btrfs_lookup_block_group(root->fs_info, start);
+ if (!cache) {
+ printk(KERN_ERR "Unable to find block group for %Lu\n", start);
+ return -ENOSPC;
+ }
+ btrfs_add_free_space(cache, start, len);
+ update_reserved_extents(root, start, len, 0);
+ return 0;
+}
+
+int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 num_bytes, u64 min_alloc_size,
+ u64 empty_size, u64 hint_byte,
+ u64 search_end, struct btrfs_key *ins,
+ u64 data)
+{
+ int ret;
+ ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
+ empty_size, hint_byte, search_end, ins,
+ data);
+ update_reserved_extents(root, ins->objectid, ins->offset, 1);
+ return ret;
+}
+
+static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner, struct btrfs_key *ins)
+{
+ int ret;
+ int pending_ret;
+ u64 super_used;
+ u64 root_used;
+ u64 num_bytes = ins->offset;
+ u32 sizes[2];
+ struct btrfs_fs_info *info = root->fs_info;
+ struct btrfs_root *extent_root = info->extent_root;
+ struct btrfs_extent_item *extent_item;
+ struct btrfs_extent_ref *ref;
+ struct btrfs_path *path;
+ struct btrfs_key keys[2];
+
+ if (parent == 0)
+ parent = ins->objectid;
+
+ /* block accounting for super block */
+ spin_lock_irq(&info->delalloc_lock);
+ super_used = btrfs_super_bytes_used(&info->super_copy);
+ btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
+ spin_unlock_irq(&info->delalloc_lock);
+
+ /* block accounting for root item */
+ root_used = btrfs_root_used(&root->root_item);
+ btrfs_set_root_used(&root->root_item, root_used + num_bytes);
+
+ if (root == extent_root) {
+ struct pending_extent_op *extent_op;
+
+ extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
+ BUG_ON(!extent_op);
+
+ extent_op->type = PENDING_EXTENT_INSERT;
+ extent_op->bytenr = ins->objectid;
+ extent_op->num_bytes = ins->offset;
+ extent_op->parent = parent;
+ extent_op->orig_parent = 0;
+ extent_op->generation = ref_generation;
+ extent_op->orig_generation = 0;
+ extent_op->level = (int)owner;
+ INIT_LIST_HEAD(&extent_op->list);
+ extent_op->del = 0;
+
+ mutex_lock(&root->fs_info->extent_ins_mutex);
+ set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
+ ins->objectid + ins->offset - 1,
+ EXTENT_WRITEBACK, GFP_NOFS);
+ set_state_private(&root->fs_info->extent_ins,
+ ins->objectid, (unsigned long)extent_op);
+ mutex_unlock(&root->fs_info->extent_ins_mutex);
+ goto update_block;
+ }
+
+ memcpy(&keys[0], ins, sizeof(*ins));
+ keys[1].objectid = ins->objectid;
+ keys[1].type = BTRFS_EXTENT_REF_KEY;
+ keys[1].offset = parent;
+ sizes[0] = sizeof(*extent_item);
+ sizes[1] = sizeof(*ref);
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
+ sizes, 2);
+ BUG_ON(ret);
+
+ extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_extent_item);
+ btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
+ struct btrfs_extent_ref);
+
+ btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
+ btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
+ btrfs_set_ref_objectid(path->nodes[0], ref, owner);
+ btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
+ trans->alloc_exclude_start = 0;
+ trans->alloc_exclude_nr = 0;
+ btrfs_free_path(path);
+ finish_current_insert(trans, extent_root, 0);
+ pending_ret = del_pending_extents(trans, extent_root, 0);
+
+ if (ret)
+ goto out;
+ if (pending_ret) {
+ ret = pending_ret;
+ goto out;
+ }
+
+update_block:
+ ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
+ if (ret) {
+ printk("update block group failed for %Lu %Lu\n",
+ ins->objectid, ins->offset);
+ BUG();
+ }
+out:
+ return ret;
+}
+
+int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner, struct btrfs_key *ins)
+{
+ int ret;
+
+ if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
+ return 0;
+ ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
+ ref_generation, owner, ins);
+ update_reserved_extents(root, ins->objectid, ins->offset, 0);
+ return ret;
+}
+
+/*
+ * this is used by the tree logging recovery code. It records that
+ * an extent has been allocated and makes sure to clear the free
+ * space cache bits as well
+ */
+int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 parent,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner, struct btrfs_key *ins)
+{
+ int ret;
+ struct btrfs_block_group_cache *block_group;
+
+ block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
+ mutex_lock(&block_group->alloc_mutex);
+ cache_block_group(root, block_group);
+
+ ret = btrfs_remove_free_space_lock(block_group, ins->objectid,
+ ins->offset);
+ mutex_unlock(&block_group->alloc_mutex);
+ BUG_ON(ret);
+ ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
+ ref_generation, owner, ins);
+ return ret;
+}
+
+/*
+ * finds a free extent and does all the dirty work required for allocation
+ * returns the key for the extent through ins, and a tree buffer for
+ * the first block of the extent through buf.
+ *
+ * returns 0 if everything worked, non-zero otherwise.
+ */
+int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 num_bytes, u64 parent, u64 min_alloc_size,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner_objectid, u64 empty_size, u64 hint_byte,
+ u64 search_end, struct btrfs_key *ins, u64 data)
+{
+ int ret;
+
+ ret = __btrfs_reserve_extent(trans, root, num_bytes,
+ min_alloc_size, empty_size, hint_byte,
+ search_end, ins, data);
+ BUG_ON(ret);
+ if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
+ ret = __btrfs_alloc_reserved_extent(trans, root, parent,
+ root_objectid, ref_generation,
+ owner_objectid, ins);
+ BUG_ON(ret);
+
+ } else {
+ update_reserved_extents(root, ins->objectid, ins->offset, 1);
+ }
+ return ret;
+}
+
+struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u32 blocksize)
+{
+ struct extent_buffer *buf;
+
+ buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+ btrfs_set_header_generation(buf, trans->transid);
+ btrfs_tree_lock(buf);
+ clean_tree_block(trans, root, buf);
+ btrfs_set_buffer_uptodate(buf);
+ if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+ set_extent_dirty(&root->dirty_log_pages, buf->start,
+ buf->start + buf->len - 1, GFP_NOFS);
+ } else {
+ set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
+ buf->start + buf->len - 1, GFP_NOFS);
+ }
+ trans->blocks_used++;
+ return buf;
+}
+
+/*
+ * helper function to allocate a block for a given tree
+ * returns the tree buffer or NULL.
+ */
+struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u32 blocksize, u64 parent,
+ u64 root_objectid,
+ u64 ref_generation,
+ int level,
+ u64 hint,
+ u64 empty_size)
+{
+ struct btrfs_key ins;
+ int ret;
+ struct extent_buffer *buf;
+
+ ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
+ root_objectid, ref_generation, level,
+ empty_size, hint, (u64)-1, &ins, 0);
+ if (ret) {
+ BUG_ON(ret > 0);
+ return ERR_PTR(ret);
+ }
+
+ buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
+ return buf;
+}
+
+int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *leaf)
+{
+ u64 leaf_owner;
+ u64 leaf_generation;
+ struct btrfs_key key;
+ struct btrfs_file_extent_item *fi;
+ int i;
+ int nritems;
+ int ret;
+
+ BUG_ON(!btrfs_is_leaf(leaf));
+ nritems = btrfs_header_nritems(leaf);
+ leaf_owner = btrfs_header_owner(leaf);
+ leaf_generation = btrfs_header_generation(leaf);
+
+ for (i = 0; i < nritems; i++) {
+ u64 disk_bytenr;
+ cond_resched();
+
+ btrfs_item_key_to_cpu(leaf, &key, i);
+ if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ /*
+ * FIXME make sure to insert a trans record that
+ * repeats the snapshot del on crash
+ */
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ if (disk_bytenr == 0)
+ continue;
+
+ ret = __btrfs_free_extent(trans, root, disk_bytenr,
+ btrfs_file_extent_disk_num_bytes(leaf, fi),
+ leaf->start, leaf_owner, leaf_generation,
+ key.objectid, 0);
+ BUG_ON(ret);
+
+ atomic_inc(&root->fs_info->throttle_gen);
+ wake_up(&root->fs_info->transaction_throttle);
+ cond_resched();
+ }
+ return 0;
+}
+
+static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_leaf_ref *ref)
+{
+ int i;
+ int ret;
+ struct btrfs_extent_info *info = ref->extents;
+
+ for (i = 0; i < ref->nritems; i++) {
+ ret = __btrfs_free_extent(trans, root, info->bytenr,
+ info->num_bytes, ref->bytenr,
+ ref->owner, ref->generation,
+ info->objectid, 0);
+
+ atomic_inc(&root->fs_info->throttle_gen);
+ wake_up(&root->fs_info->transaction_throttle);
+ cond_resched();
+
+ BUG_ON(ret);
+ info++;
+ }
+
+ return 0;
+}
+
+int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
+ u32 *refs)
+{
+ int ret;
+
+ ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
+ BUG_ON(ret);
+
+#if 0 // some debugging code in case we see problems here
+ /* if the refs count is one, it won't get increased again. But
+ * if the ref count is > 1, someone may be decreasing it at
+ * the same time we are.
+ */
+ if (*refs != 1) {
+ struct extent_buffer *eb = NULL;
+ eb = btrfs_find_create_tree_block(root, start, len);
+ if (eb)
+ btrfs_tree_lock(eb);
+
+ mutex_lock(&root->fs_info->alloc_mutex);
+ ret = lookup_extent_ref(NULL, root, start, len, refs);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->alloc_mutex);
+
+ if (eb) {
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+ }
+ if (*refs == 1) {
+ printk("block %llu went down to one during drop_snap\n",
+ (unsigned long long)start);
+ }
+
+ }
+#endif
+
+ cond_resched();
+ return ret;
+}
+
+/*
+ * helper function for drop_snapshot, this walks down the tree dropping ref
+ * counts as it goes.
+ */
+static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level)
+{
+ u64 root_owner;
+ u64 root_gen;
+ u64 bytenr;
+ u64 ptr_gen;
+ struct extent_buffer *next;
+ struct extent_buffer *cur;
+ struct extent_buffer *parent;
+ struct btrfs_leaf_ref *ref;
+ u32 blocksize;
+ int ret;
+ u32 refs;
+
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+ ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
+ path->nodes[*level]->len, &refs);
+ BUG_ON(ret);
+ if (refs > 1)
+ goto out;
+
+ /*
+ * walk down to the last node level and free all the leaves
+ */
+ while(*level >= 0) {
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+ cur = path->nodes[*level];
+
+ if (btrfs_header_level(cur) != *level)
+ WARN_ON(1);
+
+ if (path->slots[*level] >=
+ btrfs_header_nritems(cur))
+ break;
+ if (*level == 0) {
+ ret = btrfs_drop_leaf_ref(trans, root, cur);
+ BUG_ON(ret);
+ break;
+ }
+ bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
+ ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
+ blocksize = btrfs_level_size(root, *level - 1);
+
+ ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
+ BUG_ON(ret);
+ if (refs != 1) {
+ parent = path->nodes[*level];
+ root_owner = btrfs_header_owner(parent);
+ root_gen = btrfs_header_generation(parent);
+ path->slots[*level]++;
+
+ ret = __btrfs_free_extent(trans, root, bytenr,
+ blocksize, parent->start,
+ root_owner, root_gen,
+ *level - 1, 1);
+ BUG_ON(ret);
+
+ atomic_inc(&root->fs_info->throttle_gen);
+ wake_up(&root->fs_info->transaction_throttle);
+ cond_resched();
+
+ continue;
+ }
+ /*
+ * at this point, we have a single ref, and since the
+ * only place referencing this extent is a dead root
+ * the reference count should never go higher.
+ * So, we don't need to check it again
+ */
+ if (*level == 1) {
+ ref = btrfs_lookup_leaf_ref(root, bytenr);
+ if (ref && ref->generation != ptr_gen) {
+ btrfs_free_leaf_ref(root, ref);
+ ref = NULL;
+ }
+ if (ref) {
+ ret = cache_drop_leaf_ref(trans, root, ref);
+ BUG_ON(ret);
+ btrfs_remove_leaf_ref(root, ref);
+ btrfs_free_leaf_ref(root, ref);
+ *level = 0;
+ break;
+ }
+ if (printk_ratelimit()) {
+ printk("leaf ref miss for bytenr %llu\n",
+ (unsigned long long)bytenr);
+ }
+ }
+ next = btrfs_find_tree_block(root, bytenr, blocksize);
+ if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
+ free_extent_buffer(next);
+
+ next = read_tree_block(root, bytenr, blocksize,
+ ptr_gen);
+ cond_resched();
+#if 0
+ /*
+ * this is a debugging check and can go away
+ * the ref should never go all the way down to 1
+ * at this point
+ */
+ ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
+ &refs);
+ BUG_ON(ret);
+ WARN_ON(refs != 1);
+#endif
+ }
+ WARN_ON(*level <= 0);
+ if (path->nodes[*level-1])
+ free_extent_buffer(path->nodes[*level-1]);
+ path->nodes[*level-1] = next;
+ *level = btrfs_header_level(next);
+ path->slots[*level] = 0;
+ cond_resched();
+ }
+out:
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+
+ if (path->nodes[*level] == root->node) {
+ parent = path->nodes[*level];
+ bytenr = path->nodes[*level]->start;
+ } else {
+ parent = path->nodes[*level + 1];
+ bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
+ }
+
+ blocksize = btrfs_level_size(root, *level);
+ root_owner = btrfs_header_owner(parent);
+ root_gen = btrfs_header_generation(parent);
+
+ ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
+ parent->start, root_owner, root_gen,
+ *level, 1);
+ free_extent_buffer(path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level += 1;
+ BUG_ON(ret);
+
+ cond_resched();
+ return 0;
+}
+
+/*
+ * helper function for drop_subtree, this function is similar to
+ * walk_down_tree. The main difference is that it checks reference
+ * counts while tree blocks are locked.
+ */
+static int noinline walk_down_subtree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level)
+{
+ struct extent_buffer *next;
+ struct extent_buffer *cur;
+ struct extent_buffer *parent;
+ u64 bytenr;
+ u64 ptr_gen;
+ u32 blocksize;
+ u32 refs;
+ int ret;
+
+ cur = path->nodes[*level];
+ ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len,
+ &refs);
+ BUG_ON(ret);
+ if (refs > 1)
+ goto out;
+
+ while (*level >= 0) {
+ cur = path->nodes[*level];
+ if (*level == 0) {
+ ret = btrfs_drop_leaf_ref(trans, root, cur);
+ BUG_ON(ret);
+ clean_tree_block(trans, root, cur);
+ break;
+ }
+ if (path->slots[*level] >= btrfs_header_nritems(cur)) {
+ clean_tree_block(trans, root, cur);
+ break;
+ }
+
+ bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
+ blocksize = btrfs_level_size(root, *level - 1);
+ ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
+
+ next = read_tree_block(root, bytenr, blocksize, ptr_gen);
+ btrfs_tree_lock(next);
+
+ ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
+ &refs);
+ BUG_ON(ret);
+ if (refs > 1) {
+ parent = path->nodes[*level];
+ ret = btrfs_free_extent(trans, root, bytenr,
+ blocksize, parent->start,
+ btrfs_header_owner(parent),
+ btrfs_header_generation(parent),
+ *level - 1, 1);
+ BUG_ON(ret);
+ path->slots[*level]++;
+ btrfs_tree_unlock(next);
+ free_extent_buffer(next);
+ continue;
+ }
+
+ *level = btrfs_header_level(next);
+ path->nodes[*level] = next;
+ path->slots[*level] = 0;
+ path->locks[*level] = 1;
+ cond_resched();
+ }
+out:
+ parent = path->nodes[*level + 1];
+ bytenr = path->nodes[*level]->start;
+ blocksize = path->nodes[*level]->len;
+
+ ret = btrfs_free_extent(trans, root, bytenr, blocksize,
+ parent->start, btrfs_header_owner(parent),
+ btrfs_header_generation(parent), *level, 1);
+ BUG_ON(ret);
+
+ if (path->locks[*level]) {
+ btrfs_tree_unlock(path->nodes[*level]);
+ path->locks[*level] = 0;
+ }
+ free_extent_buffer(path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level += 1;
+ cond_resched();
+ return 0;
+}
+
+/*
+ * helper for dropping snapshots. This walks back up the tree in the path
+ * to find the first node higher up where we haven't yet gone through
+ * all the slots
+ */
+static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ int *level, int max_level)
+{
+ u64 root_owner;
+ u64 root_gen;
+ struct btrfs_root_item *root_item = &root->root_item;
+ int i;
+ int slot;
+ int ret;
+
+ for (i = *level; i < max_level && path->nodes[i]; i++) {
+ slot = path->slots[i];
+ if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
+ struct extent_buffer *node;
+ struct btrfs_disk_key disk_key;
+ node = path->nodes[i];
+ path->slots[i]++;
+ *level = i;
+ WARN_ON(*level == 0);
+ btrfs_node_key(node, &disk_key, path->slots[i]);
+ memcpy(&root_item->drop_progress,
+ &disk_key, sizeof(disk_key));
+ root_item->drop_level = i;
+ return 0;
+ } else {
+ struct extent_buffer *parent;
+ if (path->nodes[*level] == root->node)
+ parent = path->nodes[*level];
+ else
+ parent = path->nodes[*level + 1];
+
+ root_owner = btrfs_header_owner(parent);
+ root_gen = btrfs_header_generation(parent);
+
+ clean_tree_block(trans, root, path->nodes[*level]);
+ ret = btrfs_free_extent(trans, root,
+ path->nodes[*level]->start,
+ path->nodes[*level]->len,
+ parent->start, root_owner,
+ root_gen, *level, 1);
+ BUG_ON(ret);
+ if (path->locks[*level]) {
+ btrfs_tree_unlock(path->nodes[*level]);
+ path->locks[*level] = 0;
+ }
+ free_extent_buffer(path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level = i + 1;
+ }
+ }
+ return 1;
+}
+
+/*
+ * drop the reference count on the tree rooted at 'snap'. This traverses
+ * the tree freeing any blocks that have a ref count of zero after being
+ * decremented.
+ */
+int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root)
+{
+ int ret = 0;
+ int wret;
+ int level;
+ struct btrfs_path *path;
+ int i;
+ int orig_level;
+ struct btrfs_root_item *root_item = &root->root_item;
+
+ WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ level = btrfs_header_level(root->node);
+ orig_level = level;
+ if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
+ path->nodes[level] = root->node;
+ extent_buffer_get(root->node);
+ path->slots[level] = 0;
+ } else {
+ struct btrfs_key key;
+ struct btrfs_disk_key found_key;
+ struct extent_buffer *node;
+
+ btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
+ level = root_item->drop_level;
+ path->lowest_level = level;
+ wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (wret < 0) {
+ ret = wret;
+ goto out;
+ }
+ node = path->nodes[level];
+ btrfs_node_key(node, &found_key, path->slots[level]);
+ WARN_ON(memcmp(&found_key, &root_item->drop_progress,
+ sizeof(found_key)));
+ /*
+ * unlock our path, this is safe because only this
+ * function is allowed to delete this snapshot
+ */
+ for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+ if (path->nodes[i] && path->locks[i]) {
+ path->locks[i] = 0;
+ btrfs_tree_unlock(path->nodes[i]);
+ }
+ }
+ }
+ while(1) {
+ wret = walk_down_tree(trans, root, path, &level);
+ if (wret > 0)
+ break;
+ if (wret < 0)
+ ret = wret;
+
+ wret = walk_up_tree(trans, root, path, &level,
+ BTRFS_MAX_LEVEL);
+ if (wret > 0)
+ break;
+ if (wret < 0)
+ ret = wret;
+ if (trans->transaction->in_commit) {
+ ret = -EAGAIN;
+ break;
+ }
+ atomic_inc(&root->fs_info->throttle_gen);
+ wake_up(&root->fs_info->transaction_throttle);
+ }
+ for (i = 0; i <= orig_level; i++) {
+ if (path->nodes[i]) {
+ free_extent_buffer(path->nodes[i]);
+ path->nodes[i] = NULL;
+ }
+ }
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *node,
+ struct extent_buffer *parent)
+{
+ struct btrfs_path *path;
+ int level;
+ int parent_level;
+ int ret = 0;
+ int wret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ BUG_ON(!btrfs_tree_locked(parent));
+ parent_level = btrfs_header_level(parent);
+ extent_buffer_get(parent);
+ path->nodes[parent_level] = parent;
+ path->slots[parent_level] = btrfs_header_nritems(parent);
+
+ BUG_ON(!btrfs_tree_locked(node));
+ level = btrfs_header_level(node);
+ extent_buffer_get(node);
+ path->nodes[level] = node;
+ path->slots[level] = 0;
+
+ while (1) {
+ wret = walk_down_subtree(trans, root, path, &level);
+ if (wret < 0)
+ ret = wret;
+ if (wret != 0)
+ break;
+
+ wret = walk_up_tree(trans, root, path, &level, parent_level);
+ if (wret < 0)
+ ret = wret;
+ if (wret != 0)
+ break;
+ }
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+static unsigned long calc_ra(unsigned long start, unsigned long last,
+ unsigned long nr)
+{
+ return min(last, start + nr - 1);
+}
+
+static int noinline relocate_inode_pages(struct inode *inode, u64 start,
+ u64 len)
+{
+ u64 page_start;
+ u64 page_end;
+ unsigned long first_index;
+ unsigned long last_index;
+ unsigned long i;
+ struct page *page;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct file_ra_state *ra;
+ struct btrfs_ordered_extent *ordered;
+ unsigned int total_read = 0;
+ unsigned int total_dirty = 0;
+ int ret = 0;
+
+ ra = kzalloc(sizeof(*ra), GFP_NOFS);
+
+ mutex_lock(&inode->i_mutex);
+ first_index = start >> PAGE_CACHE_SHIFT;
+ last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
+
+ /* make sure the dirty trick played by the caller work */
+ ret = invalidate_inode_pages2_range(inode->i_mapping,
+ first_index, last_index);
+ if (ret)
+ goto out_unlock;
+
+ file_ra_state_init(ra, inode->i_mapping);
+
+ for (i = first_index ; i <= last_index; i++) {
+ if (total_read % ra->ra_pages == 0) {
+ btrfs_force_ra(inode->i_mapping, ra, NULL, i,
+ calc_ra(i, last_index, ra->ra_pages));
+ }
+ total_read++;
+again:
+ if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
+ BUG_ON(1);
+ page = grab_cache_page(inode->i_mapping, i);
+ if (!page) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+ if (!PageUptodate(page)) {
+ btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ unlock_page(page);
+ page_cache_release(page);
+ ret = -EIO;
+ goto out_unlock;
+ }
+ }
+ wait_on_page_writeback(page);
+
+ page_start = (u64)page->index << PAGE_CACHE_SHIFT;
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+ lock_extent(io_tree, page_start, page_end, GFP_NOFS);
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+ set_page_extent_mapped(page);
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+ if (i == first_index)
+ set_extent_bits(io_tree, page_start, page_end,
+ EXTENT_BOUNDARY, GFP_NOFS);
+
+ set_page_dirty(page);
+ total_dirty++;
+
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+
+out_unlock:
+ kfree(ra);
+ mutex_unlock(&inode->i_mutex);
+ balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
+ return ret;
+}
+
+static int noinline relocate_data_extent(struct inode *reloc_inode,
+ struct btrfs_key *extent_key,
+ u64 offset)
+{
+ struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
+ struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
+ struct extent_map *em;
+ u64 start = extent_key->objectid - offset;
+ u64 end = start + extent_key->offset - 1;
+
+ em = alloc_extent_map(GFP_NOFS);
+ BUG_ON(!em || IS_ERR(em));
+
+ em->start = start;
+ em->len = extent_key->offset;
+ em->block_len = extent_key->offset;
+ em->block_start = extent_key->objectid;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+
+ /* setup extent map to cheat btrfs_readpage */
+ lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
+ while (1) {
+ int ret;
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(reloc_inode, start, end, 0);
+ }
+ unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
+
+ return relocate_inode_pages(reloc_inode, start, extent_key->offset);
+}
+
+struct btrfs_ref_path {
+ u64 extent_start;
+ u64 nodes[BTRFS_MAX_LEVEL];
+ u64 root_objectid;
+ u64 root_generation;
+ u64 owner_objectid;
+ u32 num_refs;
+ int lowest_level;
+ int current_level;
+ int shared_level;
+
+ struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
+ u64 new_nodes[BTRFS_MAX_LEVEL];
+};
+
+struct disk_extent {
+ u64 ram_bytes;
+ u64 disk_bytenr;
+ u64 disk_num_bytes;
+ u64 offset;
+ u64 num_bytes;
+ u8 compression;
+ u8 encryption;
+ u16 other_encoding;
+};
+
+static int is_cowonly_root(u64 root_objectid)
+{
+ if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
+ root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
+ root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
+ root_objectid == BTRFS_DEV_TREE_OBJECTID ||
+ root_objectid == BTRFS_TREE_LOG_OBJECTID)
+ return 1;
+ return 0;
+}
+
+static int noinline __next_ref_path(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct btrfs_ref_path *ref_path,
+ int first_time)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_path *path;
+ struct btrfs_extent_ref *ref;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u64 bytenr;
+ u32 nritems;
+ int level;
+ int ret = 1;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ if (first_time) {
+ ref_path->lowest_level = -1;
+ ref_path->current_level = -1;
+ ref_path->shared_level = -1;
+ goto walk_up;
+ }
+walk_down:
+ level = ref_path->current_level - 1;
+ while (level >= -1) {
+ u64 parent;
+ if (level < ref_path->lowest_level)
+ break;
+
+ if (level >= 0) {
+ bytenr = ref_path->nodes[level];
+ } else {
+ bytenr = ref_path->extent_start;
+ }
+ BUG_ON(bytenr == 0);
+
+ parent = ref_path->nodes[level + 1];
+ ref_path->nodes[level + 1] = 0;
+ ref_path->current_level = level;
+ BUG_ON(parent == 0);
+
+ key.objectid = bytenr;
+ key.offset = parent + 1;
+ key.type = BTRFS_EXTENT_REF_KEY;
+
+ ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ BUG_ON(ret == 0);
+
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(extent_root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
+ goto next;
+ leaf = path->nodes[0];
+ }
+
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid == bytenr &&
+ found_key.type == BTRFS_EXTENT_REF_KEY) {
+ if (level < ref_path->shared_level)
+ ref_path->shared_level = level;
+ goto found;
+ }
+next:
+ level--;
+ btrfs_release_path(extent_root, path);
+ cond_resched();
+ }
+ /* reached lowest level */
+ ret = 1;
+ goto out;
+walk_up:
+ level = ref_path->current_level;
+ while (level < BTRFS_MAX_LEVEL - 1) {
+ u64 ref_objectid;
+ if (level >= 0) {
+ bytenr = ref_path->nodes[level];
+ } else {
+ bytenr = ref_path->extent_start;
+ }
+ BUG_ON(bytenr == 0);
+
+ key.objectid = bytenr;
+ key.offset = 0;
+ key.type = BTRFS_EXTENT_REF_KEY;
+
+ ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(extent_root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ /* the extent was freed by someone */
+ if (ref_path->lowest_level == level)
+ goto out;
+ btrfs_release_path(extent_root, path);
+ goto walk_down;
+ }
+ leaf = path->nodes[0];
+ }
+
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != bytenr ||
+ found_key.type != BTRFS_EXTENT_REF_KEY) {
+ /* the extent was freed by someone */
+ if (ref_path->lowest_level == level) {
+ ret = 1;
+ goto out;
+ }
+ btrfs_release_path(extent_root, path);
+ goto walk_down;
+ }
+found:
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref);
+ ref_objectid = btrfs_ref_objectid(leaf, ref);
+ if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
+ if (first_time) {
+ level = (int)ref_objectid;
+ BUG_ON(level >= BTRFS_MAX_LEVEL);
+ ref_path->lowest_level = level;
+ ref_path->current_level = level;
+ ref_path->nodes[level] = bytenr;
+ } else {
+ WARN_ON(ref_objectid != level);
+ }
+ } else {
+ WARN_ON(level != -1);
+ }
+ first_time = 0;
+
+ if (ref_path->lowest_level == level) {
+ ref_path->owner_objectid = ref_objectid;
+ ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
+ }
+
+ /*
+ * the block is tree root or the block isn't in reference
+ * counted tree.
+ */
+ if (found_key.objectid == found_key.offset ||
+ is_cowonly_root(btrfs_ref_root(leaf, ref))) {
+ ref_path->root_objectid = btrfs_ref_root(leaf, ref);
+ ref_path->root_generation =
+ btrfs_ref_generation(leaf, ref);
+ if (level < 0) {
+ /* special reference from the tree log */
+ ref_path->nodes[0] = found_key.offset;
+ ref_path->current_level = 0;
+ }
+ ret = 0;
+ goto out;
+ }
+
+ level++;
+ BUG_ON(ref_path->nodes[level] != 0);
+ ref_path->nodes[level] = found_key.offset;
+ ref_path->current_level = level;
+
+ /*
+ * the reference was created in the running transaction,
+ * no need to continue walking up.
+ */
+ if (btrfs_ref_generation(leaf, ref) == trans->transid) {
+ ref_path->root_objectid = btrfs_ref_root(leaf, ref);
+ ref_path->root_generation =
+ btrfs_ref_generation(leaf, ref);
+ ret = 0;
+ goto out;
+ }
+
+ btrfs_release_path(extent_root, path);
+ cond_resched();
+ }
+ /* reached max tree level, but no tree root found. */
+ BUG();
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct btrfs_ref_path *ref_path,
+ u64 extent_start)
+{
+ memset(ref_path, 0, sizeof(*ref_path));
+ ref_path->extent_start = extent_start;
+
+ return __next_ref_path(trans, extent_root, ref_path, 1);
+}
+
+static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct btrfs_ref_path *ref_path)
+{
+ return __next_ref_path(trans, extent_root, ref_path, 0);
+}
+
+static int noinline get_new_locations(struct inode *reloc_inode,
+ struct btrfs_key *extent_key,
+ u64 offset, int no_fragment,
+ struct disk_extent **extents,
+ int *nr_extents)
+{
+ struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
+ struct btrfs_path *path;
+ struct btrfs_file_extent_item *fi;
+ struct extent_buffer *leaf;
+ struct disk_extent *exts = *extents;
+ struct btrfs_key found_key;
+ u64 cur_pos;
+ u64 last_byte;
+ u32 nritems;
+ int nr = 0;
+ int max = *nr_extents;
+ int ret;
+
+ WARN_ON(!no_fragment && *extents);
+ if (!exts) {
+ max = 1;
+ exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
+ if (!exts)
+ return -ENOMEM;
+ }
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ cur_pos = extent_key->objectid - offset;
+ last_byte = extent_key->objectid + extent_key->offset;
+ ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
+ cur_pos, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ while (1) {
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
+ break;
+ leaf = path->nodes[0];
+ }
+
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.offset != cur_pos ||
+ found_key.type != BTRFS_EXTENT_DATA_KEY ||
+ found_key.objectid != reloc_inode->i_ino)
+ break;
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, fi) !=
+ BTRFS_FILE_EXTENT_REG ||
+ btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
+ break;
+
+ if (nr == max) {
+ struct disk_extent *old = exts;
+ max *= 2;
+ exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
+ memcpy(exts, old, sizeof(*exts) * nr);
+ if (old != *extents)
+ kfree(old);
+ }
+
+ exts[nr].disk_bytenr =
+ btrfs_file_extent_disk_bytenr(leaf, fi);
+ exts[nr].disk_num_bytes =
+ btrfs_file_extent_disk_num_bytes(leaf, fi);
+ exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
+ exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
+ exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
+ exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
+ exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
+ exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
+ fi);
+ BUG_ON(exts[nr].offset > 0);
+ BUG_ON(exts[nr].compression || exts[nr].encryption);
+ BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
+
+ cur_pos += exts[nr].num_bytes;
+ nr++;
+
+ if (cur_pos + offset >= last_byte)
+ break;
+
+ if (no_fragment) {
+ ret = 1;
+ goto out;
+ }
+ path->slots[0]++;
+ }
+
+ WARN_ON(cur_pos + offset > last_byte);
+ if (cur_pos + offset < last_byte) {
+ ret = -ENOENT;
+ goto out;
+ }
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ if (ret) {
+ if (exts != *extents)
+ kfree(exts);
+ } else {
+ *extents = exts;
+ *nr_extents = nr;
+ }
+ return ret;
+}
+
+static int noinline replace_one_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *extent_key,
+ struct btrfs_key *leaf_key,
+ struct btrfs_ref_path *ref_path,
+ struct disk_extent *new_extents,
+ int nr_extents)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *fi;
+ struct inode *inode = NULL;
+ struct btrfs_key key;
+ u64 lock_start = 0;
+ u64 lock_end = 0;
+ u64 num_bytes;
+ u64 ext_offset;
+ u64 first_pos;
+ u32 nritems;
+ int nr_scaned = 0;
+ int extent_locked = 0;
+ int extent_type;
+ int ret;
+
+ memcpy(&key, leaf_key, sizeof(key));
+ first_pos = INT_LIMIT(loff_t) - extent_key->offset;
+ if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
+ if (key.objectid < ref_path->owner_objectid ||
+ (key.objectid == ref_path->owner_objectid &&
+ key.type < BTRFS_EXTENT_DATA_KEY)) {
+ key.objectid = ref_path->owner_objectid;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = 0;
+ }
+ }
+
+ while (1) {
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0)
+ goto out;
+
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+next:
+ if (extent_locked && ret > 0) {
+ /*
+ * the file extent item was modified by someone
+ * before the extent got locked.
+ */
+ unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
+ lock_end, GFP_NOFS);
+ extent_locked = 0;
+ }
+
+ if (path->slots[0] >= nritems) {
+ if (++nr_scaned > 2)
+ break;
+
+ BUG_ON(extent_locked);
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
+ break;
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
+ if ((key.objectid > ref_path->owner_objectid) ||
+ (key.objectid == ref_path->owner_objectid &&
+ key.type > BTRFS_EXTENT_DATA_KEY) ||
+ (key.offset >= first_pos + extent_key->offset))
+ break;
+ }
+
+ if (inode && key.objectid != inode->i_ino) {
+ BUG_ON(extent_locked);
+ btrfs_release_path(root, path);
+ mutex_unlock(&inode->i_mutex);
+ iput(inode);
+ inode = NULL;
+ continue;
+ }
+
+ if (key.type != BTRFS_EXTENT_DATA_KEY) {
+ path->slots[0]++;
+ ret = 1;
+ goto next;
+ }
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+ if ((extent_type != BTRFS_FILE_EXTENT_REG &&
+ extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
+ (btrfs_file_extent_disk_bytenr(leaf, fi) !=
+ extent_key->objectid)) {
+ path->slots[0]++;
+ ret = 1;
+ goto next;
+ }
+
+ num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
+ ext_offset = btrfs_file_extent_offset(leaf, fi);
+
+ if (first_pos > key.offset - ext_offset)
+ first_pos = key.offset - ext_offset;
+
+ if (!extent_locked) {
+ lock_start = key.offset;
+ lock_end = lock_start + num_bytes - 1;
+ } else {
+ if (lock_start > key.offset ||
+ lock_end + 1 < key.offset + num_bytes) {
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ lock_start, lock_end, GFP_NOFS);
+ extent_locked = 0;
+ }
+ }
+
+ if (!inode) {
+ btrfs_release_path(root, path);
+
+ inode = btrfs_iget_locked(root->fs_info->sb,
+ key.objectid, root);
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+ BTRFS_I(inode)->location.objectid =
+ key.objectid;
+ BTRFS_I(inode)->location.type =
+ BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->location.offset = 0;
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ }
+ /*
+ * some code call btrfs_commit_transaction while
+ * holding the i_mutex, so we can't use mutex_lock
+ * here.
+ */
+ if (is_bad_inode(inode) ||
+ !mutex_trylock(&inode->i_mutex)) {
+ iput(inode);
+ inode = NULL;
+ key.offset = (u64)-1;
+ goto skip;
+ }
+ }
+
+ if (!extent_locked) {
+ struct btrfs_ordered_extent *ordered;
+
+ btrfs_release_path(root, path);
+
+ lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
+ lock_end, GFP_NOFS);
+ ordered = btrfs_lookup_first_ordered_extent(inode,
+ lock_end);
+ if (ordered &&
+ ordered->file_offset <= lock_end &&
+ ordered->file_offset + ordered->len > lock_start) {
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ lock_start, lock_end, GFP_NOFS);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ key.offset += num_bytes;
+ goto skip;
+ }
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+
+ extent_locked = 1;
+ continue;
+ }
+
+ if (nr_extents == 1) {
+ /* update extent pointer in place */
+ btrfs_set_file_extent_disk_bytenr(leaf, fi,
+ new_extents[0].disk_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi,
+ new_extents[0].disk_num_bytes);
+ btrfs_mark_buffer_dirty(leaf);
+
+ btrfs_drop_extent_cache(inode, key.offset,
+ key.offset + num_bytes - 1, 0);
+
+ ret = btrfs_inc_extent_ref(trans, root,
+ new_extents[0].disk_bytenr,
+ new_extents[0].disk_num_bytes,
+ leaf->start,
+ root->root_key.objectid,
+ trans->transid,
+ key.objectid);
+ BUG_ON(ret);
+
+ ret = btrfs_free_extent(trans, root,
+ extent_key->objectid,
+ extent_key->offset,
+ leaf->start,
+ btrfs_header_owner(leaf),
+ btrfs_header_generation(leaf),
+ key.objectid, 0);
+ BUG_ON(ret);
+
+ btrfs_release_path(root, path);
+ key.offset += num_bytes;
+ } else {
+ BUG_ON(1);
+#if 0
+ u64 alloc_hint;
+ u64 extent_len;
+ int i;
+ /*
+ * drop old extent pointer at first, then insert the
+ * new pointers one bye one
+ */
+ btrfs_release_path(root, path);
+ ret = btrfs_drop_extents(trans, root, inode, key.offset,
+ key.offset + num_bytes,
+ key.offset, &alloc_hint);
+ BUG_ON(ret);
+
+ for (i = 0; i < nr_extents; i++) {
+ if (ext_offset >= new_extents[i].num_bytes) {
+ ext_offset -= new_extents[i].num_bytes;
+ continue;
+ }
+ extent_len = min(new_extents[i].num_bytes -
+ ext_offset, num_bytes);
+
+ ret = btrfs_insert_empty_item(trans, root,
+ path, &key,
+ sizeof(*fi));
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, fi,
+ trans->transid);
+ btrfs_set_file_extent_type(leaf, fi,
+ BTRFS_FILE_EXTENT_REG);
+ btrfs_set_file_extent_disk_bytenr(leaf, fi,
+ new_extents[i].disk_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi,
+ new_extents[i].disk_num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, fi,
+ new_extents[i].ram_bytes);
+
+ btrfs_set_file_extent_compression(leaf, fi,
+ new_extents[i].compression);
+ btrfs_set_file_extent_encryption(leaf, fi,
+ new_extents[i].encryption);
+ btrfs_set_file_extent_other_encoding(leaf, fi,
+ new_extents[i].other_encoding);
+
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_len);
+ ext_offset += new_extents[i].offset;
+ btrfs_set_file_extent_offset(leaf, fi,
+ ext_offset);
+ btrfs_mark_buffer_dirty(leaf);
+
+ btrfs_drop_extent_cache(inode, key.offset,
+ key.offset + extent_len - 1, 0);
+
+ ret = btrfs_inc_extent_ref(trans, root,
+ new_extents[i].disk_bytenr,
+ new_extents[i].disk_num_bytes,
+ leaf->start,
+ root->root_key.objectid,
+ trans->transid, key.objectid);
+ BUG_ON(ret);
+ btrfs_release_path(root, path);
+
+ inode_add_bytes(inode, extent_len);
+
+ ext_offset = 0;
+ num_bytes -= extent_len;
+ key.offset += extent_len;
+
+ if (num_bytes == 0)
+ break;
+ }
+ BUG_ON(i >= nr_extents);
+#endif
+ }
+
+ if (extent_locked) {
+ unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
+ lock_end, GFP_NOFS);
+ extent_locked = 0;
+ }
+skip:
+ if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
+ key.offset >= first_pos + extent_key->offset)
+ break;
+
+ cond_resched();
+ }
+ ret = 0;
+out:
+ btrfs_release_path(root, path);
+ if (inode) {
+ mutex_unlock(&inode->i_mutex);
+ if (extent_locked) {
+ unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
+ lock_end, GFP_NOFS);
+ }
+ iput(inode);
+ }
+ return ret;
+}
+
+int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *buf, u64 orig_start)
+{
+ int level;
+ int ret;
+
+ BUG_ON(btrfs_header_generation(buf) != trans->transid);
+ BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
+
+ level = btrfs_header_level(buf);
+ if (level == 0) {
+ struct btrfs_leaf_ref *ref;
+ struct btrfs_leaf_ref *orig_ref;
+
+ orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
+ if (!orig_ref)
+ return -ENOENT;
+
+ ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
+ if (!ref) {
+ btrfs_free_leaf_ref(root, orig_ref);
+ return -ENOMEM;
+ }
+
+ ref->nritems = orig_ref->nritems;
+ memcpy(ref->extents, orig_ref->extents,
+ sizeof(ref->extents[0]) * ref->nritems);
+
+ btrfs_free_leaf_ref(root, orig_ref);
+
+ ref->root_gen = trans->transid;
+ ref->bytenr = buf->start;
+ ref->owner = btrfs_header_owner(buf);
+ ref->generation = btrfs_header_generation(buf);
+ ret = btrfs_add_leaf_ref(root, ref, 0);
+ WARN_ON(ret);
+ btrfs_free_leaf_ref(root, ref);
+ }
+ return 0;
+}
+
+static int noinline invalidate_extent_cache(struct btrfs_root *root,
+ struct extent_buffer *leaf,
+ struct btrfs_block_group_cache *group,
+ struct btrfs_root *target_root)
+{
+ struct btrfs_key key;
+ struct inode *inode = NULL;
+ struct btrfs_file_extent_item *fi;
+ u64 num_bytes;
+ u64 skip_objectid = 0;
+ u32 nritems;
+ u32 i;
+
+ nritems = btrfs_header_nritems(leaf);
+ for (i = 0; i < nritems; i++) {
+ btrfs_item_key_to_cpu(leaf, &key, i);
+ if (key.objectid == skip_objectid ||
+ key.type != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
+ continue;
+ if (!inode || inode->i_ino != key.objectid) {
+ iput(inode);
+ inode = btrfs_ilookup(target_root->fs_info->sb,
+ key.objectid, target_root, 1);
+ }
+ if (!inode) {
+ skip_objectid = key.objectid;
+ continue;
+ }
+ num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
+
+ lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
+ key.offset + num_bytes - 1, GFP_NOFS);
+ btrfs_drop_extent_cache(inode, key.offset,
+ key.offset + num_bytes - 1, 1);
+ unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
+ key.offset + num_bytes - 1, GFP_NOFS);
+ cond_resched();
+ }
+ iput(inode);
+ return 0;
+}
+
+static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *leaf,
+ struct btrfs_block_group_cache *group,
+ struct inode *reloc_inode)
+{
+ struct btrfs_key key;
+ struct btrfs_key extent_key;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_leaf_ref *ref;
+ struct disk_extent *new_extent;
+ u64 bytenr;
+ u64 num_bytes;
+ u32 nritems;
+ u32 i;
+ int ext_index;
+ int nr_extent;
+ int ret;
+
+ new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
+ BUG_ON(!new_extent);
+
+ ref = btrfs_lookup_leaf_ref(root, leaf->start);
+ BUG_ON(!ref);
+
+ ext_index = -1;
+ nritems = btrfs_header_nritems(leaf);
+ for (i = 0; i < nritems; i++) {
+ btrfs_item_key_to_cpu(leaf, &key, i);
+ if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ if (bytenr == 0)
+ continue;
+
+ ext_index++;
+ if (bytenr >= group->key.objectid + group->key.offset ||
+ bytenr + num_bytes <= group->key.objectid)
+ continue;
+
+ extent_key.objectid = bytenr;
+ extent_key.offset = num_bytes;
+ extent_key.type = BTRFS_EXTENT_ITEM_KEY;
+ nr_extent = 1;
+ ret = get_new_locations(reloc_inode, &extent_key,
+ group->key.objectid, 1,
+ &new_extent, &nr_extent);
+ if (ret > 0)
+ continue;
+ BUG_ON(ret < 0);
+
+ BUG_ON(ref->extents[ext_index].bytenr != bytenr);
+ BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
+ ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
+ ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
+
+ btrfs_set_file_extent_disk_bytenr(leaf, fi,
+ new_extent->disk_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi,
+ new_extent->disk_num_bytes);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = btrfs_inc_extent_ref(trans, root,
+ new_extent->disk_bytenr,
+ new_extent->disk_num_bytes,
+ leaf->start,
+ root->root_key.objectid,
+ trans->transid, key.objectid);
+ BUG_ON(ret);
+ ret = btrfs_free_extent(trans, root,
+ bytenr, num_bytes, leaf->start,
+ btrfs_header_owner(leaf),
+ btrfs_header_generation(leaf),
+ key.objectid, 0);
+ BUG_ON(ret);
+ cond_resched();
+ }
+ kfree(new_extent);
+ BUG_ON(ext_index + 1 != ref->nritems);
+ btrfs_free_leaf_ref(root, ref);
+ return 0;
+}
+
+int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_root *reloc_root;
+ int ret;
+
+ if (root->reloc_root) {
+ reloc_root = root->reloc_root;
+ root->reloc_root = NULL;
+ list_add(&reloc_root->dead_list,
+ &root->fs_info->dead_reloc_roots);
+
+ btrfs_set_root_bytenr(&reloc_root->root_item,
+ reloc_root->node->start);
+ btrfs_set_root_level(&root->root_item,
+ btrfs_header_level(reloc_root->node));
+ memset(&reloc_root->root_item.drop_progress, 0,
+ sizeof(struct btrfs_disk_key));
+ reloc_root->root_item.drop_level = 0;
+
+ ret = btrfs_update_root(trans, root->fs_info->tree_root,
+ &reloc_root->root_key,
+ &reloc_root->root_item);
+ BUG_ON(ret);
+ }
+ return 0;
+}
+
+int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *reloc_root;
+ struct btrfs_root *prev_root = NULL;
+ struct list_head dead_roots;
+ int ret;
+ unsigned long nr;
+
+ INIT_LIST_HEAD(&dead_roots);
+ list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
+
+ while (!list_empty(&dead_roots)) {
+ reloc_root = list_entry(dead_roots.prev,
+ struct btrfs_root, dead_list);
+ list_del_init(&reloc_root->dead_list);
+
+ BUG_ON(reloc_root->commit_root != NULL);
+ while (1) {
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+
+ mutex_lock(&root->fs_info->drop_mutex);
+ ret = btrfs_drop_snapshot(trans, reloc_root);
+ if (ret != -EAGAIN)
+ break;
+ mutex_unlock(&root->fs_info->drop_mutex);
+
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ btrfs_btree_balance_dirty(root, nr);
+ }
+
+ free_extent_buffer(reloc_root->node);
+
+ ret = btrfs_del_root(trans, root->fs_info->tree_root,
+ &reloc_root->root_key);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->drop_mutex);
+
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ btrfs_btree_balance_dirty(root, nr);
+
+ kfree(prev_root);
+ prev_root = reloc_root;
+ }
+ if (prev_root) {
+ btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
+ kfree(prev_root);
+ }
+ return 0;
+}
+
+int btrfs_add_dead_reloc_root(struct btrfs_root *root)
+{
+ list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
+ return 0;
+}
+
+int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
+{
+ struct btrfs_root *reloc_root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key location;
+ int found;
+ int ret;
+
+ mutex_lock(&root->fs_info->tree_reloc_mutex);
+ ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
+ BUG_ON(ret);
+ found = !list_empty(&root->fs_info->dead_reloc_roots);
+ mutex_unlock(&root->fs_info->tree_reloc_mutex);
+
+ if (found) {
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+ ret = btrfs_commit_transaction(trans, root);
+ BUG_ON(ret);
+ }
+
+ location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
+ location.offset = (u64)-1;
+ location.type = BTRFS_ROOT_ITEM_KEY;
+
+ reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
+ BUG_ON(!reloc_root);
+ btrfs_orphan_cleanup(reloc_root);
+ return 0;
+}
+
+static int noinline init_reloc_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_root *reloc_root;
+ struct extent_buffer *eb;
+ struct btrfs_root_item *root_item;
+ struct btrfs_key root_key;
+ int ret;
+
+ BUG_ON(!root->ref_cows);
+ if (root->reloc_root)
+ return 0;
+
+ root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
+ BUG_ON(!root_item);
+
+ ret = btrfs_copy_root(trans, root, root->commit_root,
+ &eb, BTRFS_TREE_RELOC_OBJECTID);
+ BUG_ON(ret);
+
+ root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
+ root_key.offset = root->root_key.objectid;
+ root_key.type = BTRFS_ROOT_ITEM_KEY;
+
+ memcpy(root_item, &root->root_item, sizeof(root_item));
+ btrfs_set_root_refs(root_item, 0);
+ btrfs_set_root_bytenr(root_item, eb->start);
+ btrfs_set_root_level(root_item, btrfs_header_level(eb));
+ btrfs_set_root_generation(root_item, trans->transid);
+
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root,
+ &root_key, root_item);
+ BUG_ON(ret);
+ kfree(root_item);
+
+ reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
+ &root_key);
+ BUG_ON(!reloc_root);
+ reloc_root->last_trans = trans->transid;
+ reloc_root->commit_root = NULL;
+ reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
+
+ root->reloc_root = reloc_root;
+ return 0;
+}
+
+/*
+ * Core function of space balance.
+ *
+ * The idea is using reloc trees to relocate tree blocks in reference
+ * counted roots. There is one reloc tree for each subvol, and all
+ * reloc trees share same root key objectid. Reloc trees are snapshots
+ * of the latest committed roots of subvols (root->commit_root).
+ *
+ * To relocate a tree block referenced by a subvol, there are two steps.
+ * COW the block through subvol's reloc tree, then update block pointer
+ * in the subvol to point to the new block. Since all reloc trees share
+ * same root key objectid, doing special handing for tree blocks owned
+ * by them is easy. Once a tree block has been COWed in one reloc tree,
+ * we can use the resulting new block directly when the same block is
+ * required to COW again through other reloc trees. By this way, relocated
+ * tree blocks are shared between reloc trees, so they are also shared
+ * between subvols.
+ */
+static int noinline relocate_one_path(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *first_key,
+ struct btrfs_ref_path *ref_path,
+ struct btrfs_block_group_cache *group,
+ struct inode *reloc_inode)
+{
+ struct btrfs_root *reloc_root;
+ struct extent_buffer *eb = NULL;
+ struct btrfs_key *keys;
+ u64 *nodes;
+ int level;
+ int shared_level;
+ int lowest_level = 0;
+ int ret;
+
+ if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
+ lowest_level = ref_path->owner_objectid;
+
+ if (!root->ref_cows) {
+ path->lowest_level = lowest_level;
+ ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
+ BUG_ON(ret < 0);
+ path->lowest_level = 0;
+ btrfs_release_path(root, path);
+ return 0;
+ }
+
+ mutex_lock(&root->fs_info->tree_reloc_mutex);
+ ret = init_reloc_tree(trans, root);
+ BUG_ON(ret);
+ reloc_root = root->reloc_root;
+
+ shared_level = ref_path->shared_level;
+ ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
+
+ keys = ref_path->node_keys;
+ nodes = ref_path->new_nodes;
+ memset(&keys[shared_level + 1], 0,
+ sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
+ memset(&nodes[shared_level + 1], 0,
+ sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
+
+ if (nodes[lowest_level] == 0) {
+ path->lowest_level = lowest_level;
+ ret = btrfs_search_slot(trans, reloc_root, first_key, path,
+ 0, 1);
+ BUG_ON(ret);
+ for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
+ eb = path->nodes[level];
+ if (!eb || eb == reloc_root->node)
+ break;
+ nodes[level] = eb->start;
+ if (level == 0)
+ btrfs_item_key_to_cpu(eb, &keys[level], 0);
+ else
+ btrfs_node_key_to_cpu(eb, &keys[level], 0);
+ }
+ if (nodes[0] &&
+ ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
+ eb = path->nodes[0];
+ ret = replace_extents_in_leaf(trans, reloc_root, eb,
+ group, reloc_inode);
+ BUG_ON(ret);
+ }
+ btrfs_release_path(reloc_root, path);
+ } else {
+ ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
+ lowest_level);
+ BUG_ON(ret);
+ }
+
+ /*
+ * replace tree blocks in the fs tree with tree blocks in
+ * the reloc tree.
+ */
+ ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
+ BUG_ON(ret < 0);
+
+ if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
+ ret = btrfs_search_slot(trans, reloc_root, first_key, path,
+ 0, 0);
+ BUG_ON(ret);
+ extent_buffer_get(path->nodes[0]);
+ eb = path->nodes[0];
+ btrfs_release_path(reloc_root, path);
+ ret = invalidate_extent_cache(reloc_root, eb, group, root);
+ BUG_ON(ret);
+ free_extent_buffer(eb);
+ }
+
+ mutex_unlock(&root->fs_info->tree_reloc_mutex);
+ path->lowest_level = 0;
+ return 0;
+}
+
+static int noinline relocate_tree_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *first_key,
+ struct btrfs_ref_path *ref_path)
+{
+ int ret;
+
+ ret = relocate_one_path(trans, root, path, first_key,
+ ref_path, NULL, NULL);
+ BUG_ON(ret);
+
+ if (root == root->fs_info->extent_root)
+ btrfs_extent_post_op(trans, root);
+
+ return 0;
+}
+
+static int noinline del_extent_zero(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct btrfs_path *path,
+ struct btrfs_key *extent_key)
+{
+ int ret;
+
+ ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
+ if (ret)
+ goto out;
+ ret = btrfs_del_item(trans, extent_root, path);
+out:
+ btrfs_release_path(extent_root, path);
+ return ret;
+}
+
+static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info,
+ struct btrfs_ref_path *ref_path)
+{
+ struct btrfs_key root_key;
+
+ root_key.objectid = ref_path->root_objectid;
+ root_key.type = BTRFS_ROOT_ITEM_KEY;
+ if (is_cowonly_root(ref_path->root_objectid))
+ root_key.offset = 0;
+ else
+ root_key.offset = (u64)-1;
+
+ return btrfs_read_fs_root_no_name(fs_info, &root_key);
+}
+
+static int noinline relocate_one_extent(struct btrfs_root *extent_root,
+ struct btrfs_path *path,
+ struct btrfs_key *extent_key,
+ struct btrfs_block_group_cache *group,
+ struct inode *reloc_inode, int pass)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *found_root;
+ struct btrfs_ref_path *ref_path = NULL;
+ struct disk_extent *new_extents = NULL;
+ int nr_extents = 0;
+ int loops;
+ int ret;
+ int level;
+ struct btrfs_key first_key;
+ u64 prev_block = 0;
+
+
+ trans = btrfs_start_transaction(extent_root, 1);
+ BUG_ON(!trans);
+
+ if (extent_key->objectid == 0) {
+ ret = del_extent_zero(trans, extent_root, path, extent_key);
+ goto out;
+ }
+
+ ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
+ if (!ref_path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ for (loops = 0; ; loops++) {
+ if (loops == 0) {
+ ret = btrfs_first_ref_path(trans, extent_root, ref_path,
+ extent_key->objectid);
+ } else {
+ ret = btrfs_next_ref_path(trans, extent_root, ref_path);
+ }
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
+ break;
+
+ if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
+ ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
+ continue;
+
+ found_root = read_ref_root(extent_root->fs_info, ref_path);
+ BUG_ON(!found_root);
+ /*
+ * for reference counted tree, only process reference paths
+ * rooted at the latest committed root.
+ */
+ if (found_root->ref_cows &&
+ ref_path->root_generation != found_root->root_key.offset)
+ continue;
+
+ if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
+ if (pass == 0) {
+ /*
+ * copy data extents to new locations
+ */
+ u64 group_start = group->key.objectid;
+ ret = relocate_data_extent(reloc_inode,
+ extent_key,
+ group_start);
+ if (ret < 0)
+ goto out;
+ break;
+ }
+ level = 0;
+ } else {
+ level = ref_path->owner_objectid;
+ }
+
+ if (prev_block != ref_path->nodes[level]) {
+ struct extent_buffer *eb;
+ u64 block_start = ref_path->nodes[level];
+ u64 block_size = btrfs_level_size(found_root, level);
+
+ eb = read_tree_block(found_root, block_start,
+ block_size, 0);
+ btrfs_tree_lock(eb);
+ BUG_ON(level != btrfs_header_level(eb));
+
+ if (level == 0)
+ btrfs_item_key_to_cpu(eb, &first_key, 0);
+ else
+ btrfs_node_key_to_cpu(eb, &first_key, 0);
+
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+ prev_block = block_start;
+ }
+
+ if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
+ pass >= 2) {
+ /*
+ * use fallback method to process the remaining
+ * references.
+ */
+ if (!new_extents) {
+ u64 group_start = group->key.objectid;
+ new_extents = kmalloc(sizeof(*new_extents),
+ GFP_NOFS);
+ nr_extents = 1;
+ ret = get_new_locations(reloc_inode,
+ extent_key,
+ group_start, 1,
+ &new_extents,
+ &nr_extents);
+ if (ret)
+ goto out;
+ }
+ btrfs_record_root_in_trans(found_root);
+ ret = replace_one_extent(trans, found_root,
+ path, extent_key,
+ &first_key, ref_path,
+ new_extents, nr_extents);
+ if (ret < 0)
+ goto out;
+ continue;
+ }
+
+ btrfs_record_root_in_trans(found_root);
+ if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
+ ret = relocate_tree_block(trans, found_root, path,
+ &first_key, ref_path);
+ } else {
+ /*
+ * try to update data extent references while
+ * keeping metadata shared between snapshots.
+ */
+ ret = relocate_one_path(trans, found_root, path,
+ &first_key, ref_path,
+ group, reloc_inode);
+ }
+ if (ret < 0)
+ goto out;
+ }
+ ret = 0;
+out:
+ btrfs_end_transaction(trans, extent_root);
+ kfree(new_extents);
+ kfree(ref_path);
+ return ret;
+}
+
+static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
+{
+ u64 num_devices;
+ u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
+
+ num_devices = root->fs_info->fs_devices->rw_devices;
+ if (num_devices == 1) {
+ stripped |= BTRFS_BLOCK_GROUP_DUP;
+ stripped = flags & ~stripped;
+
+ /* turn raid0 into single device chunks */
+ if (flags & BTRFS_BLOCK_GROUP_RAID0)
+ return stripped;
+
+ /* turn mirroring into duplication */
+ if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))
+ return stripped | BTRFS_BLOCK_GROUP_DUP;
+ return flags;
+ } else {
+ /* they already had raid on here, just return */
+ if (flags & stripped)
+ return flags;
+
+ stripped |= BTRFS_BLOCK_GROUP_DUP;
+ stripped = flags & ~stripped;
+
+ /* switch duplicated blocks with raid1 */
+ if (flags & BTRFS_BLOCK_GROUP_DUP)
+ return stripped | BTRFS_BLOCK_GROUP_RAID1;
+
+ /* turn single device chunks into raid0 */
+ return stripped | BTRFS_BLOCK_GROUP_RAID0;
+ }
+ return flags;
+}
+
+int __alloc_chunk_for_shrink(struct btrfs_root *root,
+ struct btrfs_block_group_cache *shrink_block_group,
+ int force)
+{
+ struct btrfs_trans_handle *trans;
+ u64 new_alloc_flags;
+ u64 calc;
+
+ spin_lock(&shrink_block_group->lock);
+ if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
+ spin_unlock(&shrink_block_group->lock);
+
+ trans = btrfs_start_transaction(root, 1);
+ spin_lock(&shrink_block_group->lock);
+
+ new_alloc_flags = update_block_group_flags(root,
+ shrink_block_group->flags);
+ if (new_alloc_flags != shrink_block_group->flags) {
+ calc =
+ btrfs_block_group_used(&shrink_block_group->item);
+ } else {
+ calc = shrink_block_group->key.offset;
+ }
+ spin_unlock(&shrink_block_group->lock);
+
+ do_chunk_alloc(trans, root->fs_info->extent_root,
+ calc + 2 * 1024 * 1024, new_alloc_flags, force);
+
+ btrfs_end_transaction(trans, root);
+ } else
+ spin_unlock(&shrink_block_group->lock);
+ return 0;
+}
+
+static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 size)
+{
+ struct btrfs_path *path;
+ struct btrfs_inode_item *item;
+ struct extent_buffer *leaf;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_insert_empty_inode(trans, root, path, objectid);
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
+ memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
+ btrfs_set_inode_generation(leaf, item, 1);
+ btrfs_set_inode_size(leaf, item, size);
+ btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
+ btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM |
+ BTRFS_INODE_NOCOMPRESS);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(root, path);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache *group)
+{
+ struct inode *inode = NULL;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root;
+ struct btrfs_key root_key;
+ u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
+ int err = 0;
+
+ root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
+ root_key.type = BTRFS_ROOT_ITEM_KEY;
+ root_key.offset = (u64)-1;
+ root = btrfs_read_fs_root_no_name(fs_info, &root_key);
+ if (IS_ERR(root))
+ return ERR_CAST(root);
+
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+
+ err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
+ if (err)
+ goto out;
+
+ err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
+ BUG_ON(err);
+
+ err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
+ group->key.offset, 0, group->key.offset,
+ 0, 0, 0);
+ BUG_ON(err);
+
+ inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+ BTRFS_I(inode)->location.objectid = objectid;
+ BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->location.offset = 0;
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ BUG_ON(is_bad_inode(inode));
+ } else {
+ BUG_ON(1);
+ }
+
+ err = btrfs_orphan_add(trans, inode);
+out:
+ btrfs_end_transaction(trans, root);
+ if (err) {
+ if (inode)
+ iput(inode);
+ inode = ERR_PTR(err);
+ }
+ return inode;
+}
+
+int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_path *path;
+ struct btrfs_fs_info *info = root->fs_info;
+ struct extent_buffer *leaf;
+ struct inode *reloc_inode;
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_key key;
+ u64 skipped;
+ u64 cur_byte;
+ u64 total_found;
+ u32 nritems;
+ int ret;
+ int progress;
+ int pass = 0;
+
+ root = root->fs_info->extent_root;
+
+ block_group = btrfs_lookup_block_group(info, group_start);
+ BUG_ON(!block_group);
+
+ printk("btrfs relocating block group %llu flags %llu\n",
+ (unsigned long long)block_group->key.objectid,
+ (unsigned long long)block_group->flags);
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ reloc_inode = create_reloc_inode(info, block_group);
+ BUG_ON(IS_ERR(reloc_inode));
+
+ __alloc_chunk_for_shrink(root, block_group, 1);
+ set_block_group_readonly(block_group);
+
+ btrfs_start_delalloc_inodes(info->tree_root);
+ btrfs_wait_ordered_extents(info->tree_root, 0);
+again:
+ skipped = 0;
+ total_found = 0;
+ progress = 0;
+ key.objectid = block_group->key.objectid;
+ key.offset = 0;
+ key.type = 0;
+ cur_byte = key.objectid;
+
+ trans = btrfs_start_transaction(info->tree_root, 1);
+ btrfs_commit_transaction(trans, info->tree_root);
+
+ mutex_lock(&root->fs_info->cleaner_mutex);
+ btrfs_clean_old_snapshots(info->tree_root);
+ btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
+ mutex_unlock(&root->fs_info->cleaner_mutex);
+
+ while(1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+next:
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret == 1) {
+ ret = 0;
+ break;
+ }
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ if (key.objectid >= block_group->key.objectid +
+ block_group->key.offset)
+ break;
+
+ if (progress && need_resched()) {
+ btrfs_release_path(root, path);
+ cond_resched();
+ progress = 0;
+ continue;
+ }
+ progress = 1;
+
+ if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
+ key.objectid + key.offset <= cur_byte) {
+ path->slots[0]++;
+ goto next;
+ }
+
+ total_found++;
+ cur_byte = key.objectid + key.offset;
+ btrfs_release_path(root, path);
+
+ __alloc_chunk_for_shrink(root, block_group, 0);
+ ret = relocate_one_extent(root, path, &key, block_group,
+ reloc_inode, pass);
+ BUG_ON(ret < 0);
+ if (ret > 0)
+ skipped++;
+
+ key.objectid = cur_byte;
+ key.type = 0;
+ key.offset = 0;
+ }
+
+ btrfs_release_path(root, path);
+
+ if (pass == 0) {
+ btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
+ invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
+ WARN_ON(reloc_inode->i_mapping->nrpages);
+ }
+
+ if (total_found > 0) {
+ printk("btrfs found %llu extents in pass %d\n",
+ (unsigned long long)total_found, pass);
+ pass++;
+ if (total_found == skipped && pass > 2) {
+ iput(reloc_inode);
+ reloc_inode = create_reloc_inode(info, block_group);
+ pass = 0;
+ }
+ goto again;
+ }
+
+ /* delete reloc_inode */
+ iput(reloc_inode);
+
+ /* unpin extents in this range */
+ trans = btrfs_start_transaction(info->tree_root, 1);
+ btrfs_commit_transaction(trans, info->tree_root);
+
+ spin_lock(&block_group->lock);
+ WARN_ON(block_group->pinned > 0);
+ WARN_ON(block_group->reserved > 0);
+ WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
+ spin_unlock(&block_group->lock);
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *key)
+{
+ int ret = 0;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ int slot;
+
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ while(1) {
+ slot = path->slots[0];
+ leaf = path->nodes[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto out;
+ break;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ if (found_key.objectid >= key->objectid &&
+ found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
+ ret = 0;
+ goto out;
+ }
+ path->slots[0]++;
+ }
+ ret = -ENOENT;
+out:
+ return ret;
+}
+
+int btrfs_free_block_groups(struct btrfs_fs_info *info)
+{
+ struct btrfs_block_group_cache *block_group;
+ struct rb_node *n;
+
+ spin_lock(&info->block_group_cache_lock);
+ while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
+ block_group = rb_entry(n, struct btrfs_block_group_cache,
+ cache_node);
+ rb_erase(&block_group->cache_node,
+ &info->block_group_cache_tree);
+ spin_unlock(&info->block_group_cache_lock);
+
+ btrfs_remove_free_space_cache(block_group);
+ down_write(&block_group->space_info->groups_sem);
+ list_del(&block_group->list);
+ up_write(&block_group->space_info->groups_sem);
+ kfree(block_group);
+
+ spin_lock(&info->block_group_cache_lock);
+ }
+ spin_unlock(&info->block_group_cache_lock);
+ return 0;
+}
+
+int btrfs_read_block_groups(struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_fs_info *info = root->fs_info;
+ struct btrfs_space_info *space_info;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+
+ root = info->extent_root;
+ key.objectid = 0;
+ key.offset = 0;
+ btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ while(1) {
+ ret = find_first_block_group(root, path, &key);
+ if (ret > 0) {
+ ret = 0;
+ goto error;
+ }
+ if (ret != 0)
+ goto error;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ cache = kzalloc(sizeof(*cache), GFP_NOFS);
+ if (!cache) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ spin_lock_init(&cache->lock);
+ mutex_init(&cache->alloc_mutex);
+ INIT_LIST_HEAD(&cache->list);
+ read_extent_buffer(leaf, &cache->item,
+ btrfs_item_ptr_offset(leaf, path->slots[0]),
+ sizeof(cache->item));
+ memcpy(&cache->key, &found_key, sizeof(found_key));
+
+ key.objectid = found_key.objectid + found_key.offset;
+ btrfs_release_path(root, path);
+ cache->flags = btrfs_block_group_flags(&cache->item);
+
+ ret = update_space_info(info, cache->flags, found_key.offset,
+ btrfs_block_group_used(&cache->item),
+ &space_info);
+ BUG_ON(ret);
+ cache->space_info = space_info;
+ down_write(&space_info->groups_sem);
+ list_add_tail(&cache->list, &space_info->block_groups);
+ up_write(&space_info->groups_sem);
+
+ ret = btrfs_add_block_group_cache(root->fs_info, cache);
+ BUG_ON(ret);
+
+ set_avail_alloc_bits(root->fs_info, cache->flags);
+ if (btrfs_chunk_readonly(root, cache->key.objectid))
+ set_block_group_readonly(cache);
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_make_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytes_used,
+ u64 type, u64 chunk_objectid, u64 chunk_offset,
+ u64 size)
+{
+ int ret;
+ struct btrfs_root *extent_root;
+ struct btrfs_block_group_cache *cache;
+
+ extent_root = root->fs_info->extent_root;
+
+ root->fs_info->last_trans_new_blockgroup = trans->transid;
+
+ cache = kzalloc(sizeof(*cache), GFP_NOFS);
+ if (!cache)
+ return -ENOMEM;
+
+ cache->key.objectid = chunk_offset;
+ cache->key.offset = size;
+ spin_lock_init(&cache->lock);
+ mutex_init(&cache->alloc_mutex);
+ INIT_LIST_HEAD(&cache->list);
+ btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
+
+ btrfs_set_block_group_used(&cache->item, bytes_used);
+ btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
+ cache->flags = type;
+ btrfs_set_block_group_flags(&cache->item, type);
+
+ ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
+ &cache->space_info);
+ BUG_ON(ret);
+ down_write(&cache->space_info->groups_sem);
+ list_add_tail(&cache->list, &cache->space_info->block_groups);
+ up_write(&cache->space_info->groups_sem);
+
+ ret = btrfs_add_block_group_cache(root->fs_info, cache);
+ BUG_ON(ret);
+
+ ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
+ sizeof(cache->item));
+ BUG_ON(ret);
+
+ finish_current_insert(trans, extent_root, 0);
+ ret = del_pending_extents(trans, extent_root, 0);
+ BUG_ON(ret);
+ set_avail_alloc_bits(extent_root->fs_info, type);
+
+ return 0;
+}
+
+int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 group_start)
+{
+ struct btrfs_path *path;
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_key key;
+ int ret;
+
+ root = root->fs_info->extent_root;
+
+ block_group = btrfs_lookup_block_group(root->fs_info, group_start);
+ BUG_ON(!block_group);
+ BUG_ON(!block_group->ro);
+
+ memcpy(&key, &block_group->key, sizeof(key));
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ btrfs_remove_free_space_cache(block_group);
+ rb_erase(&block_group->cache_node,
+ &root->fs_info->block_group_cache_tree);
+ down_write(&block_group->space_info->groups_sem);
+ list_del(&block_group->list);
+ up_write(&block_group->space_info->groups_sem);
+
+ spin_lock(&block_group->space_info->lock);
+ block_group->space_info->total_bytes -= block_group->key.offset;
+ block_group->space_info->bytes_readonly -= block_group->key.offset;
+ spin_unlock(&block_group->space_info->lock);
+ block_group->space_info->full = 0;
+
+ /*
+ memset(shrink_block_group, 0, sizeof(*shrink_block_group));
+ kfree(shrink_block_group);
+ */
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0)
+ ret = -EIO;
+ if (ret < 0)
+ goto out;
+
+ ret = btrfs_del_item(trans, root, path);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
new file mode 100644
index 0000000..a0f3804
--- /dev/null
+++ b/fs/btrfs/extent_io.c
@@ -0,0 +1,3787 @@
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/bio.h>
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/pagemap.h>
+#include <linux/page-flags.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/blkdev.h>
+#include <linux/swap.h>
+#include <linux/version.h>
+#include <linux/writeback.h>
+#include <linux/pagevec.h>
+#include "extent_io.h"
+#include "extent_map.h"
+#include "compat.h"
+#include "ctree.h"
+#include "btrfs_inode.h"
+
+/* temporary define until extent_map moves out of btrfs */
+struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
+ unsigned long extra_flags,
+ void (*ctor)(void *, struct kmem_cache *,
+ unsigned long));
+
+static struct kmem_cache *extent_state_cache;
+static struct kmem_cache *extent_buffer_cache;
+
+static LIST_HEAD(buffers);
+static LIST_HEAD(states);
+
+#define LEAK_DEBUG 0
+#ifdef LEAK_DEBUG
+static spinlock_t leak_lock = SPIN_LOCK_UNLOCKED;
+#endif
+
+#define BUFFER_LRU_MAX 64
+
+struct tree_entry {
+ u64 start;
+ u64 end;
+ struct rb_node rb_node;
+};
+
+struct extent_page_data {
+ struct bio *bio;
+ struct extent_io_tree *tree;
+ get_extent_t *get_extent;
+
+ /* tells writepage not to lock the state bits for this range
+ * it still does the unlocking
+ */
+ int extent_locked;
+};
+
+int __init extent_io_init(void)
+{
+ extent_state_cache = btrfs_cache_create("extent_state",
+ sizeof(struct extent_state), 0,
+ NULL);
+ if (!extent_state_cache)
+ return -ENOMEM;
+
+ extent_buffer_cache = btrfs_cache_create("extent_buffers",
+ sizeof(struct extent_buffer), 0,
+ NULL);
+ if (!extent_buffer_cache)
+ goto free_state_cache;
+ return 0;
+
+free_state_cache:
+ kmem_cache_destroy(extent_state_cache);
+ return -ENOMEM;
+}
+
+void extent_io_exit(void)
+{
+ struct extent_state *state;
+ struct extent_buffer *eb;
+
+ while (!list_empty(&states)) {
+ state = list_entry(states.next, struct extent_state, leak_list);
+ printk("state leak: start %Lu end %Lu state %lu in tree %p refs %d\n", state->start, state->end, state->state, state->tree, atomic_read(&state->refs));
+ list_del(&state->leak_list);
+ kmem_cache_free(extent_state_cache, state);
+
+ }
+
+ while (!list_empty(&buffers)) {
+ eb = list_entry(buffers.next, struct extent_buffer, leak_list);
+ printk("buffer leak start %Lu len %lu refs %d\n", eb->start, eb->len, atomic_read(&eb->refs));
+ list_del(&eb->leak_list);
+ kmem_cache_free(extent_buffer_cache, eb);
+ }
+ if (extent_state_cache)
+ kmem_cache_destroy(extent_state_cache);
+ if (extent_buffer_cache)
+ kmem_cache_destroy(extent_buffer_cache);
+}
+
+void extent_io_tree_init(struct extent_io_tree *tree,
+ struct address_space *mapping, gfp_t mask)
+{
+ tree->state.rb_node = NULL;
+ tree->buffer.rb_node = NULL;
+ tree->ops = NULL;
+ tree->dirty_bytes = 0;
+ spin_lock_init(&tree->lock);
+ spin_lock_init(&tree->buffer_lock);
+ tree->mapping = mapping;
+}
+EXPORT_SYMBOL(extent_io_tree_init);
+
+struct extent_state *alloc_extent_state(gfp_t mask)
+{
+ struct extent_state *state;
+#ifdef LEAK_DEBUG
+ unsigned long flags;
+#endif
+
+ state = kmem_cache_alloc(extent_state_cache, mask);
+ if (!state)
+ return state;
+ state->state = 0;
+ state->private = 0;
+ state->tree = NULL;
+#ifdef LEAK_DEBUG
+ spin_lock_irqsave(&leak_lock, flags);
+ list_add(&state->leak_list, &states);
+ spin_unlock_irqrestore(&leak_lock, flags);
+#endif
+ atomic_set(&state->refs, 1);
+ init_waitqueue_head(&state->wq);
+ return state;
+}
+EXPORT_SYMBOL(alloc_extent_state);
+
+void free_extent_state(struct extent_state *state)
+{
+ if (!state)
+ return;
+ if (atomic_dec_and_test(&state->refs)) {
+#ifdef LEAK_DEBUG
+ unsigned long flags;
+#endif
+ WARN_ON(state->tree);
+#ifdef LEAK_DEBUG
+ spin_lock_irqsave(&leak_lock, flags);
+ list_del(&state->leak_list);
+ spin_unlock_irqrestore(&leak_lock, flags);
+#endif
+ kmem_cache_free(extent_state_cache, state);
+ }
+}
+EXPORT_SYMBOL(free_extent_state);
+
+static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
+ struct rb_node *node)
+{
+ struct rb_node ** p = &root->rb_node;
+ struct rb_node * parent = NULL;
+ struct tree_entry *entry;
+
+ while(*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct tree_entry, rb_node);
+
+ if (offset < entry->start)
+ p = &(*p)->rb_left;
+ else if (offset > entry->end)
+ p = &(*p)->rb_right;
+ else
+ return parent;
+ }
+
+ entry = rb_entry(node, struct tree_entry, rb_node);
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+ return NULL;
+}
+
+static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
+ struct rb_node **prev_ret,
+ struct rb_node **next_ret)
+{
+ struct rb_root *root = &tree->state;
+ struct rb_node * n = root->rb_node;
+ struct rb_node *prev = NULL;
+ struct rb_node *orig_prev = NULL;
+ struct tree_entry *entry;
+ struct tree_entry *prev_entry = NULL;
+
+ while(n) {
+ entry = rb_entry(n, struct tree_entry, rb_node);
+ prev = n;
+ prev_entry = entry;
+
+ if (offset < entry->start)
+ n = n->rb_left;
+ else if (offset > entry->end)
+ n = n->rb_right;
+ else {
+ return n;
+ }
+ }
+
+ if (prev_ret) {
+ orig_prev = prev;
+ while(prev && offset > prev_entry->end) {
+ prev = rb_next(prev);
+ prev_entry = rb_entry(prev, struct tree_entry, rb_node);
+ }
+ *prev_ret = prev;
+ prev = orig_prev;
+ }
+
+ if (next_ret) {
+ prev_entry = rb_entry(prev, struct tree_entry, rb_node);
+ while(prev && offset < prev_entry->start) {
+ prev = rb_prev(prev);
+ prev_entry = rb_entry(prev, struct tree_entry, rb_node);
+ }
+ *next_ret = prev;
+ }
+ return NULL;
+}
+
+static inline struct rb_node *tree_search(struct extent_io_tree *tree,
+ u64 offset)
+{
+ struct rb_node *prev = NULL;
+ struct rb_node *ret;
+
+ ret = __etree_search(tree, offset, &prev, NULL);
+ if (!ret) {
+ return prev;
+ }
+ return ret;
+}
+
+static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree,
+ u64 offset, struct rb_node *node)
+{
+ struct rb_root *root = &tree->buffer;
+ struct rb_node ** p = &root->rb_node;
+ struct rb_node * parent = NULL;
+ struct extent_buffer *eb;
+
+ while(*p) {
+ parent = *p;
+ eb = rb_entry(parent, struct extent_buffer, rb_node);
+
+ if (offset < eb->start)
+ p = &(*p)->rb_left;
+ else if (offset > eb->start)
+ p = &(*p)->rb_right;
+ else
+ return eb;
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+ return NULL;
+}
+
+static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
+ u64 offset)
+{
+ struct rb_root *root = &tree->buffer;
+ struct rb_node * n = root->rb_node;
+ struct extent_buffer *eb;
+
+ while(n) {
+ eb = rb_entry(n, struct extent_buffer, rb_node);
+ if (offset < eb->start)
+ n = n->rb_left;
+ else if (offset > eb->start)
+ n = n->rb_right;
+ else
+ return eb;
+ }
+ return NULL;
+}
+
+/*
+ * utility function to look for merge candidates inside a given range.
+ * Any extents with matching state are merged together into a single
+ * extent in the tree. Extents with EXTENT_IO in their state field
+ * are not merged because the end_io handlers need to be able to do
+ * operations on them without sleeping (or doing allocations/splits).
+ *
+ * This should be called with the tree lock held.
+ */
+static int merge_state(struct extent_io_tree *tree,
+ struct extent_state *state)
+{
+ struct extent_state *other;
+ struct rb_node *other_node;
+
+ if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
+ return 0;
+
+ other_node = rb_prev(&state->rb_node);
+ if (other_node) {
+ other = rb_entry(other_node, struct extent_state, rb_node);
+ if (other->end == state->start - 1 &&
+ other->state == state->state) {
+ state->start = other->start;
+ other->tree = NULL;
+ rb_erase(&other->rb_node, &tree->state);
+ free_extent_state(other);
+ }
+ }
+ other_node = rb_next(&state->rb_node);
+ if (other_node) {
+ other = rb_entry(other_node, struct extent_state, rb_node);
+ if (other->start == state->end + 1 &&
+ other->state == state->state) {
+ other->start = state->start;
+ state->tree = NULL;
+ rb_erase(&state->rb_node, &tree->state);
+ free_extent_state(state);
+ }
+ }
+ return 0;
+}
+
+static void set_state_cb(struct extent_io_tree *tree,
+ struct extent_state *state,
+ unsigned long bits)
+{
+ if (tree->ops && tree->ops->set_bit_hook) {
+ tree->ops->set_bit_hook(tree->mapping->host, state->start,
+ state->end, state->state, bits);
+ }
+}
+
+static void clear_state_cb(struct extent_io_tree *tree,
+ struct extent_state *state,
+ unsigned long bits)
+{
+ if (tree->ops && tree->ops->set_bit_hook) {
+ tree->ops->clear_bit_hook(tree->mapping->host, state->start,
+ state->end, state->state, bits);
+ }
+}
+
+/*
+ * insert an extent_state struct into the tree. 'bits' are set on the
+ * struct before it is inserted.
+ *
+ * This may return -EEXIST if the extent is already there, in which case the
+ * state struct is freed.
+ *
+ * The tree lock is not taken internally. This is a utility function and
+ * probably isn't what you want to call (see set/clear_extent_bit).
+ */
+static int insert_state(struct extent_io_tree *tree,
+ struct extent_state *state, u64 start, u64 end,
+ int bits)
+{
+ struct rb_node *node;
+
+ if (end < start) {
+ printk("end < start %Lu %Lu\n", end, start);
+ WARN_ON(1);
+ }
+ if (bits & EXTENT_DIRTY)
+ tree->dirty_bytes += end - start + 1;
+ set_state_cb(tree, state, bits);
+ state->state |= bits;
+ state->start = start;
+ state->end = end;
+ node = tree_insert(&tree->state, end, &state->rb_node);
+ if (node) {
+ struct extent_state *found;
+ found = rb_entry(node, struct extent_state, rb_node);
+ printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end);
+ free_extent_state(state);
+ return -EEXIST;
+ }
+ state->tree = tree;
+ merge_state(tree, state);
+ return 0;
+}
+
+/*
+ * split a given extent state struct in two, inserting the preallocated
+ * struct 'prealloc' as the newly created second half. 'split' indicates an
+ * offset inside 'orig' where it should be split.
+ *
+ * Before calling,
+ * the tree has 'orig' at [orig->start, orig->end]. After calling, there
+ * are two extent state structs in the tree:
+ * prealloc: [orig->start, split - 1]
+ * orig: [ split, orig->end ]
+ *
+ * The tree locks are not taken by this function. They need to be held
+ * by the caller.
+ */
+static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
+ struct extent_state *prealloc, u64 split)
+{
+ struct rb_node *node;
+ prealloc->start = orig->start;
+ prealloc->end = split - 1;
+ prealloc->state = orig->state;
+ orig->start = split;
+
+ node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
+ if (node) {
+ struct extent_state *found;
+ found = rb_entry(node, struct extent_state, rb_node);
+ printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end);
+ free_extent_state(prealloc);
+ return -EEXIST;
+ }
+ prealloc->tree = tree;
+ return 0;
+}
+
+/*
+ * utility function to clear some bits in an extent state struct.
+ * it will optionally wake up any one waiting on this state (wake == 1), or
+ * forcibly remove the state from the tree (delete == 1).
+ *
+ * If no bits are set on the state struct after clearing things, the
+ * struct is freed and removed from the tree
+ */
+static int clear_state_bit(struct extent_io_tree *tree,
+ struct extent_state *state, int bits, int wake,
+ int delete)
+{
+ int ret = state->state & bits;
+
+ if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
+ u64 range = state->end - state->start + 1;
+ WARN_ON(range > tree->dirty_bytes);
+ tree->dirty_bytes -= range;
+ }
+ clear_state_cb(tree, state, bits);
+ state->state &= ~bits;
+ if (wake)
+ wake_up(&state->wq);
+ if (delete || state->state == 0) {
+ if (state->tree) {
+ clear_state_cb(tree, state, state->state);
+ rb_erase(&state->rb_node, &tree->state);
+ state->tree = NULL;
+ free_extent_state(state);
+ } else {
+ WARN_ON(1);
+ }
+ } else {
+ merge_state(tree, state);
+ }
+ return ret;
+}
+
+/*
+ * clear some bits on a range in the tree. This may require splitting
+ * or inserting elements in the tree, so the gfp mask is used to
+ * indicate which allocations or sleeping are allowed.
+ *
+ * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
+ * the given range from the tree regardless of state (ie for truncate).
+ *
+ * the range [start, end] is inclusive.
+ *
+ * This takes the tree lock, and returns < 0 on error, > 0 if any of the
+ * bits were already set, or zero if none of the bits were already set.
+ */
+int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, int wake, int delete, gfp_t mask)
+{
+ struct extent_state *state;
+ struct extent_state *prealloc = NULL;
+ struct rb_node *node;
+ unsigned long flags;
+ int err;
+ int set = 0;
+
+again:
+ if (!prealloc && (mask & __GFP_WAIT)) {
+ prealloc = alloc_extent_state(mask);
+ if (!prealloc)
+ return -ENOMEM;
+ }
+
+ spin_lock_irqsave(&tree->lock, flags);
+ /*
+ * this search will find the extents that end after
+ * our range starts
+ */
+ node = tree_search(tree, start);
+ if (!node)
+ goto out;
+ state = rb_entry(node, struct extent_state, rb_node);
+ if (state->start > end)
+ goto out;
+ WARN_ON(state->end < start);
+
+ /*
+ * | ---- desired range ---- |
+ * | state | or
+ * | ------------- state -------------- |
+ *
+ * We need to split the extent we found, and may flip
+ * bits on second half.
+ *
+ * If the extent we found extends past our range, we
+ * just split and search again. It'll get split again
+ * the next time though.
+ *
+ * If the extent we found is inside our range, we clear
+ * the desired bit on it.
+ */
+
+ if (state->start < start) {
+ if (!prealloc)
+ prealloc = alloc_extent_state(GFP_ATOMIC);
+ err = split_state(tree, state, prealloc, start);
+ BUG_ON(err == -EEXIST);
+ prealloc = NULL;
+ if (err)
+ goto out;
+ if (state->end <= end) {
+ start = state->end + 1;
+ set |= clear_state_bit(tree, state, bits,
+ wake, delete);
+ } else {
+ start = state->start;
+ }
+ goto search_again;
+ }
+ /*
+ * | ---- desired range ---- |
+ * | state |
+ * We need to split the extent, and clear the bit
+ * on the first half
+ */
+ if (state->start <= end && state->end > end) {
+ if (!prealloc)
+ prealloc = alloc_extent_state(GFP_ATOMIC);
+ err = split_state(tree, state, prealloc, end + 1);
+ BUG_ON(err == -EEXIST);
+
+ if (wake)
+ wake_up(&state->wq);
+ set |= clear_state_bit(tree, prealloc, bits,
+ wake, delete);
+ prealloc = NULL;
+ goto out;
+ }
+
+ start = state->end + 1;
+ set |= clear_state_bit(tree, state, bits, wake, delete);
+ goto search_again;
+
+out:
+ spin_unlock_irqrestore(&tree->lock, flags);
+ if (prealloc)
+ free_extent_state(prealloc);
+
+ return set;
+
+search_again:
+ if (start > end)
+ goto out;
+ spin_unlock_irqrestore(&tree->lock, flags);
+ if (mask & __GFP_WAIT)
+ cond_resched();
+ goto again;
+}
+EXPORT_SYMBOL(clear_extent_bit);
+
+static int wait_on_state(struct extent_io_tree *tree,
+ struct extent_state *state)
+{
+ DEFINE_WAIT(wait);
+ prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
+ spin_unlock_irq(&tree->lock);
+ schedule();
+ spin_lock_irq(&tree->lock);
+ finish_wait(&state->wq, &wait);
+ return 0;
+}
+
+/*
+ * waits for one or more bits to clear on a range in the state tree.
+ * The range [start, end] is inclusive.
+ * The tree lock is taken by this function
+ */
+int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
+{
+ struct extent_state *state;
+ struct rb_node *node;
+
+ spin_lock_irq(&tree->lock);
+again:
+ while (1) {
+ /*
+ * this search will find all the extents that end after
+ * our range starts
+ */
+ node = tree_search(tree, start);
+ if (!node)
+ break;
+
+ state = rb_entry(node, struct extent_state, rb_node);
+
+ if (state->start > end)
+ goto out;
+
+ if (state->state & bits) {
+ start = state->start;
+ atomic_inc(&state->refs);
+ wait_on_state(tree, state);
+ free_extent_state(state);
+ goto again;
+ }
+ start = state->end + 1;
+
+ if (start > end)
+ break;
+
+ if (need_resched()) {
+ spin_unlock_irq(&tree->lock);
+ cond_resched();
+ spin_lock_irq(&tree->lock);
+ }
+ }
+out:
+ spin_unlock_irq(&tree->lock);
+ return 0;
+}
+EXPORT_SYMBOL(wait_extent_bit);
+
+static void set_state_bits(struct extent_io_tree *tree,
+ struct extent_state *state,
+ int bits)
+{
+ if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
+ u64 range = state->end - state->start + 1;
+ tree->dirty_bytes += range;
+ }
+ set_state_cb(tree, state, bits);
+ state->state |= bits;
+}
+
+/*
+ * set some bits on a range in the tree. This may require allocations
+ * or sleeping, so the gfp mask is used to indicate what is allowed.
+ *
+ * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
+ * range already has the desired bits set. The start of the existing
+ * range is returned in failed_start in this case.
+ *
+ * [start, end] is inclusive
+ * This takes the tree lock.
+ */
+int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
+ int exclusive, u64 *failed_start, gfp_t mask)
+{
+ struct extent_state *state;
+ struct extent_state *prealloc = NULL;
+ struct rb_node *node;
+ unsigned long flags;
+ int err = 0;
+ int set;
+ u64 last_start;
+ u64 last_end;
+again:
+ if (!prealloc && (mask & __GFP_WAIT)) {
+ prealloc = alloc_extent_state(mask);
+ if (!prealloc)
+ return -ENOMEM;
+ }
+
+ spin_lock_irqsave(&tree->lock, flags);
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(tree, start);
+ if (!node) {
+ err = insert_state(tree, prealloc, start, end, bits);
+ prealloc = NULL;
+ BUG_ON(err == -EEXIST);
+ goto out;
+ }
+
+ state = rb_entry(node, struct extent_state, rb_node);
+ last_start = state->start;
+ last_end = state->end;
+
+ /*
+ * | ---- desired range ---- |
+ * | state |
+ *
+ * Just lock what we found and keep going
+ */
+ if (state->start == start && state->end <= end) {
+ set = state->state & bits;
+ if (set && exclusive) {
+ *failed_start = state->start;
+ err = -EEXIST;
+ goto out;
+ }
+ set_state_bits(tree, state, bits);
+ start = state->end + 1;
+ merge_state(tree, state);
+ goto search_again;
+ }
+
+ /*
+ * | ---- desired range ---- |
+ * | state |
+ * or
+ * | ------------- state -------------- |
+ *
+ * We need to split the extent we found, and may flip bits on
+ * second half.
+ *
+ * If the extent we found extends past our
+ * range, we just split and search again. It'll get split
+ * again the next time though.
+ *
+ * If the extent we found is inside our range, we set the
+ * desired bit on it.
+ */
+ if (state->start < start) {
+ set = state->state & bits;
+ if (exclusive && set) {
+ *failed_start = start;
+ err = -EEXIST;
+ goto out;
+ }
+ err = split_state(tree, state, prealloc, start);
+ BUG_ON(err == -EEXIST);
+ prealloc = NULL;
+ if (err)
+ goto out;
+ if (state->end <= end) {
+ set_state_bits(tree, state, bits);
+ start = state->end + 1;
+ merge_state(tree, state);
+ } else {
+ start = state->start;
+ }
+ goto search_again;
+ }
+ /*
+ * | ---- desired range ---- |
+ * | state | or | state |
+ *
+ * There's a hole, we need to insert something in it and
+ * ignore the extent we found.
+ */
+ if (state->start > start) {
+ u64 this_end;
+ if (end < last_start)
+ this_end = end;
+ else
+ this_end = last_start -1;
+ err = insert_state(tree, prealloc, start, this_end,
+ bits);
+ prealloc = NULL;
+ BUG_ON(err == -EEXIST);
+ if (err)
+ goto out;
+ start = this_end + 1;
+ goto search_again;
+ }
+ /*
+ * | ---- desired range ---- |
+ * | state |
+ * We need to split the extent, and set the bit
+ * on the first half
+ */
+ if (state->start <= end && state->end > end) {
+ set = state->state & bits;
+ if (exclusive && set) {
+ *failed_start = start;
+ err = -EEXIST;
+ goto out;
+ }
+ err = split_state(tree, state, prealloc, end + 1);
+ BUG_ON(err == -EEXIST);
+
+ set_state_bits(tree, prealloc, bits);
+ merge_state(tree, prealloc);
+ prealloc = NULL;
+ goto out;
+ }
+
+ goto search_again;
+
+out:
+ spin_unlock_irqrestore(&tree->lock, flags);
+ if (prealloc)
+ free_extent_state(prealloc);
+
+ return err;
+
+search_again:
+ if (start > end)
+ goto out;
+ spin_unlock_irqrestore(&tree->lock, flags);
+ if (mask & __GFP_WAIT)
+ cond_resched();
+ goto again;
+}
+EXPORT_SYMBOL(set_extent_bit);
+
+/* wrappers around set/clear extent bit */
+int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
+ mask);
+}
+EXPORT_SYMBOL(set_extent_dirty);
+
+int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return set_extent_bit(tree, start, end, EXTENT_ORDERED, 0, NULL, mask);
+}
+EXPORT_SYMBOL(set_extent_ordered);
+
+int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, gfp_t mask)
+{
+ return set_extent_bit(tree, start, end, bits, 0, NULL,
+ mask);
+}
+EXPORT_SYMBOL(set_extent_bits);
+
+int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, gfp_t mask)
+{
+ return clear_extent_bit(tree, start, end, bits, 0, 0, mask);
+}
+EXPORT_SYMBOL(clear_extent_bits);
+
+int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return set_extent_bit(tree, start, end,
+ EXTENT_DELALLOC | EXTENT_DIRTY,
+ 0, NULL, mask);
+}
+EXPORT_SYMBOL(set_extent_delalloc);
+
+int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return clear_extent_bit(tree, start, end,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
+}
+EXPORT_SYMBOL(clear_extent_dirty);
+
+int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return clear_extent_bit(tree, start, end, EXTENT_ORDERED, 1, 0, mask);
+}
+EXPORT_SYMBOL(clear_extent_ordered);
+
+int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
+ mask);
+}
+EXPORT_SYMBOL(set_extent_new);
+
+int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
+}
+EXPORT_SYMBOL(clear_extent_new);
+
+int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
+ mask);
+}
+EXPORT_SYMBOL(set_extent_uptodate);
+
+int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
+}
+EXPORT_SYMBOL(clear_extent_uptodate);
+
+int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
+ 0, NULL, mask);
+}
+EXPORT_SYMBOL(set_extent_writeback);
+
+int clear_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
+}
+EXPORT_SYMBOL(clear_extent_writeback);
+
+int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
+{
+ return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
+}
+EXPORT_SYMBOL(wait_on_extent_writeback);
+
+/*
+ * either insert or lock state struct between start and end use mask to tell
+ * us if waiting is desired.
+ */
+int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
+{
+ int err;
+ u64 failed_start;
+ while (1) {
+ err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
+ &failed_start, mask);
+ if (err == -EEXIST && (mask & __GFP_WAIT)) {
+ wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
+ start = failed_start;
+ } else {
+ break;
+ }
+ WARN_ON(start > end);
+ }
+ return err;
+}
+EXPORT_SYMBOL(lock_extent);
+
+int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ int err;
+ u64 failed_start;
+
+ err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
+ &failed_start, mask);
+ if (err == -EEXIST) {
+ if (failed_start > start)
+ clear_extent_bit(tree, start, failed_start - 1,
+ EXTENT_LOCKED, 1, 0, mask);
+ return 0;
+ }
+ return 1;
+}
+EXPORT_SYMBOL(try_lock_extent);
+
+int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask)
+{
+ return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
+}
+EXPORT_SYMBOL(unlock_extent);
+
+/*
+ * helper function to set pages and extents in the tree dirty
+ */
+int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
+{
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+ struct page *page;
+
+ while (index <= end_index) {
+ page = find_get_page(tree->mapping, index);
+ BUG_ON(!page);
+ __set_page_dirty_nobuffers(page);
+ page_cache_release(page);
+ index++;
+ }
+ set_extent_dirty(tree, start, end, GFP_NOFS);
+ return 0;
+}
+EXPORT_SYMBOL(set_range_dirty);
+
+/*
+ * helper function to set both pages and extents in the tree writeback
+ */
+int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
+{
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+ struct page *page;
+
+ while (index <= end_index) {
+ page = find_get_page(tree->mapping, index);
+ BUG_ON(!page);
+ set_page_writeback(page);
+ page_cache_release(page);
+ index++;
+ }
+ set_extent_writeback(tree, start, end, GFP_NOFS);
+ return 0;
+}
+EXPORT_SYMBOL(set_range_writeback);
+
+/*
+ * find the first offset in the io tree with 'bits' set. zero is
+ * returned if we find something, and *start_ret and *end_ret are
+ * set to reflect the state struct that was found.
+ *
+ * If nothing was found, 1 is returned, < 0 on error
+ */
+int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
+ u64 *start_ret, u64 *end_ret, int bits)
+{
+ struct rb_node *node;
+ struct extent_state *state;
+ int ret = 1;
+
+ spin_lock_irq(&tree->lock);
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(tree, start);
+ if (!node) {
+ goto out;
+ }
+
+ while(1) {
+ state = rb_entry(node, struct extent_state, rb_node);
+ if (state->end >= start && (state->state & bits)) {
+ *start_ret = state->start;
+ *end_ret = state->end;
+ ret = 0;
+ break;
+ }
+ node = rb_next(node);
+ if (!node)
+ break;
+ }
+out:
+ spin_unlock_irq(&tree->lock);
+ return ret;
+}
+EXPORT_SYMBOL(find_first_extent_bit);
+
+/* find the first state struct with 'bits' set after 'start', and
+ * return it. tree->lock must be held. NULL will returned if
+ * nothing was found after 'start'
+ */
+struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
+ u64 start, int bits)
+{
+ struct rb_node *node;
+ struct extent_state *state;
+
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(tree, start);
+ if (!node) {
+ goto out;
+ }
+
+ while(1) {
+ state = rb_entry(node, struct extent_state, rb_node);
+ if (state->end >= start && (state->state & bits)) {
+ return state;
+ }
+ node = rb_next(node);
+ if (!node)
+ break;
+ }
+out:
+ return NULL;
+}
+EXPORT_SYMBOL(find_first_extent_bit_state);
+
+/*
+ * find a contiguous range of bytes in the file marked as delalloc, not
+ * more than 'max_bytes'. start and end are used to return the range,
+ *
+ * 1 is returned if we find something, 0 if nothing was in the tree
+ */
+static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
+ u64 *start, u64 *end, u64 max_bytes)
+{
+ struct rb_node *node;
+ struct extent_state *state;
+ u64 cur_start = *start;
+ u64 found = 0;
+ u64 total_bytes = 0;
+
+ spin_lock_irq(&tree->lock);
+
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(tree, cur_start);
+ if (!node) {
+ if (!found)
+ *end = (u64)-1;
+ goto out;
+ }
+
+ while(1) {
+ state = rb_entry(node, struct extent_state, rb_node);
+ if (found && (state->start != cur_start ||
+ (state->state & EXTENT_BOUNDARY))) {
+ goto out;
+ }
+ if (!(state->state & EXTENT_DELALLOC)) {
+ if (!found)
+ *end = state->end;
+ goto out;
+ }
+ if (!found)
+ *start = state->start;
+ found++;
+ *end = state->end;
+ cur_start = state->end + 1;
+ node = rb_next(node);
+ if (!node)
+ break;
+ total_bytes += state->end - state->start + 1;
+ if (total_bytes >= max_bytes)
+ break;
+ }
+out:
+ spin_unlock_irq(&tree->lock);
+ return found;
+}
+
+static noinline int __unlock_for_delalloc(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end)
+{
+ int ret;
+ struct page *pages[16];
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+ unsigned long nr_pages = end_index - index + 1;
+ int i;
+
+ if (index == locked_page->index && end_index == index)
+ return 0;
+
+ while(nr_pages > 0) {
+ ret = find_get_pages_contig(inode->i_mapping, index,
+ min_t(unsigned long, nr_pages,
+ ARRAY_SIZE(pages)), pages);
+ for (i = 0; i < ret; i++) {
+ if (pages[i] != locked_page)
+ unlock_page(pages[i]);
+ page_cache_release(pages[i]);
+ }
+ nr_pages -= ret;
+ index += ret;
+ cond_resched();
+ }
+ return 0;
+}
+
+static noinline int lock_delalloc_pages(struct inode *inode,
+ struct page *locked_page,
+ u64 delalloc_start,
+ u64 delalloc_end)
+{
+ unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
+ unsigned long start_index = index;
+ unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
+ unsigned long pages_locked = 0;
+ struct page *pages[16];
+ unsigned long nrpages;
+ int ret;
+ int i;
+
+ /* the caller is responsible for locking the start index */
+ if (index == locked_page->index && index == end_index)
+ return 0;
+
+ /* skip the page at the start index */
+ nrpages = end_index - index + 1;
+ while(nrpages > 0) {
+ ret = find_get_pages_contig(inode->i_mapping, index,
+ min_t(unsigned long,
+ nrpages, ARRAY_SIZE(pages)), pages);
+ if (ret == 0) {
+ ret = -EAGAIN;
+ goto done;
+ }
+ /* now we have an array of pages, lock them all */
+ for (i = 0; i < ret; i++) {
+ /*
+ * the caller is taking responsibility for
+ * locked_page
+ */
+ if (pages[i] != locked_page) {
+ lock_page(pages[i]);
+ if (!PageDirty(pages[i]) ||
+ pages[i]->mapping != inode->i_mapping) {
+ ret = -EAGAIN;
+ unlock_page(pages[i]);
+ page_cache_release(pages[i]);
+ goto done;
+ }
+ }
+ page_cache_release(pages[i]);
+ pages_locked++;
+ }
+ nrpages -= ret;
+ index += ret;
+ cond_resched();
+ }
+ ret = 0;
+done:
+ if (ret && pages_locked) {
+ __unlock_for_delalloc(inode, locked_page,
+ delalloc_start,
+ ((u64)(start_index + pages_locked - 1)) <<
+ PAGE_CACHE_SHIFT);
+ }
+ return ret;
+}
+
+/*
+ * find a contiguous range of bytes in the file marked as delalloc, not
+ * more than 'max_bytes'. start and end are used to return the range,
+ *
+ * 1 is returned if we find something, 0 if nothing was in the tree
+ */
+static noinline u64 find_lock_delalloc_range(struct inode *inode,
+ struct extent_io_tree *tree,
+ struct page *locked_page,
+ u64 *start, u64 *end,
+ u64 max_bytes)
+{
+ u64 delalloc_start;
+ u64 delalloc_end;
+ u64 found;
+ int ret;
+ int loops = 0;
+
+again:
+ /* step one, find a bunch of delalloc bytes starting at start */
+ delalloc_start = *start;
+ delalloc_end = 0;
+ found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
+ max_bytes);
+ if (!found || delalloc_end <= *start) {
+ *start = delalloc_start;
+ *end = delalloc_end;
+ return found;
+ }
+
+ /*
+ * start comes from the offset of locked_page. We have to lock
+ * pages in order, so we can't process delalloc bytes before
+ * locked_page
+ */
+ if (delalloc_start < *start) {
+ delalloc_start = *start;
+ }
+
+ /*
+ * make sure to limit the number of pages we try to lock down
+ * if we're looping.
+ */
+ if (delalloc_end + 1 - delalloc_start > max_bytes && loops) {
+ delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
+ }
+ /* step two, lock all the pages after the page that has start */
+ ret = lock_delalloc_pages(inode, locked_page,
+ delalloc_start, delalloc_end);
+ if (ret == -EAGAIN) {
+ /* some of the pages are gone, lets avoid looping by
+ * shortening the size of the delalloc range we're searching
+ */
+ if (!loops) {
+ unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
+ max_bytes = PAGE_CACHE_SIZE - offset;
+ loops = 1;
+ goto again;
+ } else {
+ found = 0;
+ goto out_failed;
+ }
+ }
+ BUG_ON(ret);
+
+ /* step three, lock the state bits for the whole range */
+ lock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);
+
+ /* then test to make sure it is all still delalloc */
+ ret = test_range_bit(tree, delalloc_start, delalloc_end,
+ EXTENT_DELALLOC, 1);
+ if (!ret) {
+ unlock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);
+ __unlock_for_delalloc(inode, locked_page,
+ delalloc_start, delalloc_end);
+ cond_resched();
+ goto again;
+ }
+ *start = delalloc_start;
+ *end = delalloc_end;
+out_failed:
+ return found;
+}
+
+int extent_clear_unlock_delalloc(struct inode *inode,
+ struct extent_io_tree *tree,
+ u64 start, u64 end, struct page *locked_page,
+ int unlock_pages,
+ int clear_unlock,
+ int clear_delalloc, int clear_dirty,
+ int set_writeback,
+ int end_writeback)
+{
+ int ret;
+ struct page *pages[16];
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+ unsigned long nr_pages = end_index - index + 1;
+ int i;
+ int clear_bits = 0;
+
+ if (clear_unlock)
+ clear_bits |= EXTENT_LOCKED;
+ if (clear_dirty)
+ clear_bits |= EXTENT_DIRTY;
+
+ if (clear_delalloc)
+ clear_bits |= EXTENT_DELALLOC;
+
+ clear_extent_bit(tree, start, end, clear_bits, 1, 0, GFP_NOFS);
+ if (!(unlock_pages || clear_dirty || set_writeback || end_writeback))
+ return 0;
+
+ while(nr_pages > 0) {
+ ret = find_get_pages_contig(inode->i_mapping, index,
+ min_t(unsigned long,
+ nr_pages, ARRAY_SIZE(pages)), pages);
+ for (i = 0; i < ret; i++) {
+ if (pages[i] == locked_page) {
+ page_cache_release(pages[i]);
+ continue;
+ }
+ if (clear_dirty)
+ clear_page_dirty_for_io(pages[i]);
+ if (set_writeback)
+ set_page_writeback(pages[i]);
+ if (end_writeback)
+ end_page_writeback(pages[i]);
+ if (unlock_pages)
+ unlock_page(pages[i]);
+ page_cache_release(pages[i]);
+ }
+ nr_pages -= ret;
+ index += ret;
+ cond_resched();
+ }
+ return 0;
+}
+EXPORT_SYMBOL(extent_clear_unlock_delalloc);
+
+/*
+ * count the number of bytes in the tree that have a given bit(s)
+ * set. This can be fairly slow, except for EXTENT_DIRTY which is
+ * cached. The total number found is returned.
+ */
+u64 count_range_bits(struct extent_io_tree *tree,
+ u64 *start, u64 search_end, u64 max_bytes,
+ unsigned long bits)
+{
+ struct rb_node *node;
+ struct extent_state *state;
+ u64 cur_start = *start;
+ u64 total_bytes = 0;
+ int found = 0;
+
+ if (search_end <= cur_start) {
+ printk("search_end %Lu start %Lu\n", search_end, cur_start);
+ WARN_ON(1);
+ return 0;
+ }
+
+ spin_lock_irq(&tree->lock);
+ if (cur_start == 0 && bits == EXTENT_DIRTY) {
+ total_bytes = tree->dirty_bytes;
+ goto out;
+ }
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(tree, cur_start);
+ if (!node) {
+ goto out;
+ }
+
+ while(1) {
+ state = rb_entry(node, struct extent_state, rb_node);
+ if (state->start > search_end)
+ break;
+ if (state->end >= cur_start && (state->state & bits)) {
+ total_bytes += min(search_end, state->end) + 1 -
+ max(cur_start, state->start);
+ if (total_bytes >= max_bytes)
+ break;
+ if (!found) {
+ *start = state->start;
+ found = 1;
+ }
+ }
+ node = rb_next(node);
+ if (!node)
+ break;
+ }
+out:
+ spin_unlock_irq(&tree->lock);
+ return total_bytes;
+}
+/*
+ * helper function to lock both pages and extents in the tree.
+ * pages must be locked first.
+ */
+int lock_range(struct extent_io_tree *tree, u64 start, u64 end)
+{
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+ struct page *page;
+ int err;
+
+ while (index <= end_index) {
+ page = grab_cache_page(tree->mapping, index);
+ if (!page) {
+ err = -ENOMEM;
+ goto failed;
+ }
+ if (IS_ERR(page)) {
+ err = PTR_ERR(page);
+ goto failed;
+ }
+ index++;
+ }
+ lock_extent(tree, start, end, GFP_NOFS);
+ return 0;
+
+failed:
+ /*
+ * we failed above in getting the page at 'index', so we undo here
+ * up to but not including the page at 'index'
+ */
+ end_index = index;
+ index = start >> PAGE_CACHE_SHIFT;
+ while (index < end_index) {
+ page = find_get_page(tree->mapping, index);
+ unlock_page(page);
+ page_cache_release(page);
+ index++;
+ }
+ return err;
+}
+EXPORT_SYMBOL(lock_range);
+
+/*
+ * helper function to unlock both pages and extents in the tree.
+ */
+int unlock_range(struct extent_io_tree *tree, u64 start, u64 end)
+{
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+ struct page *page;
+
+ while (index <= end_index) {
+ page = find_get_page(tree->mapping, index);
+ unlock_page(page);
+ page_cache_release(page);
+ index++;
+ }
+ unlock_extent(tree, start, end, GFP_NOFS);
+ return 0;
+}
+EXPORT_SYMBOL(unlock_range);
+
+/*
+ * set the private field for a given byte offset in the tree. If there isn't
+ * an extent_state there already, this does nothing.
+ */
+int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
+{
+ struct rb_node *node;
+ struct extent_state *state;
+ int ret = 0;
+
+ spin_lock_irq(&tree->lock);
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(tree, start);
+ if (!node) {
+ ret = -ENOENT;
+ goto out;
+ }
+ state = rb_entry(node, struct extent_state, rb_node);
+ if (state->start != start) {
+ ret = -ENOENT;
+ goto out;
+ }
+ state->private = private;
+out:
+ spin_unlock_irq(&tree->lock);
+ return ret;
+}
+
+int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
+{
+ struct rb_node *node;
+ struct extent_state *state;
+ int ret = 0;
+
+ spin_lock_irq(&tree->lock);
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(tree, start);
+ if (!node) {
+ ret = -ENOENT;
+ goto out;
+ }
+ state = rb_entry(node, struct extent_state, rb_node);
+ if (state->start != start) {
+ ret = -ENOENT;
+ goto out;
+ }
+ *private = state->private;
+out:
+ spin_unlock_irq(&tree->lock);
+ return ret;
+}
+
+/*
+ * searches a range in the state tree for a given mask.
+ * If 'filled' == 1, this returns 1 only if every extent in the tree
+ * has the bits set. Otherwise, 1 is returned if any bit in the
+ * range is found set.
+ */
+int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, int filled)
+{
+ struct extent_state *state = NULL;
+ struct rb_node *node;
+ int bitset = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tree->lock, flags);
+ node = tree_search(tree, start);
+ while (node && start <= end) {
+ state = rb_entry(node, struct extent_state, rb_node);
+
+ if (filled && state->start > start) {
+ bitset = 0;
+ break;
+ }
+
+ if (state->start > end)
+ break;
+
+ if (state->state & bits) {
+ bitset = 1;
+ if (!filled)
+ break;
+ } else if (filled) {
+ bitset = 0;
+ break;
+ }
+ start = state->end + 1;
+ if (start > end)
+ break;
+ node = rb_next(node);
+ if (!node) {
+ if (filled)
+ bitset = 0;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&tree->lock, flags);
+ return bitset;
+}
+EXPORT_SYMBOL(test_range_bit);
+
+/*
+ * helper function to set a given page up to date if all the
+ * extents in the tree for that page are up to date
+ */
+static int check_page_uptodate(struct extent_io_tree *tree,
+ struct page *page)
+{
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 end = start + PAGE_CACHE_SIZE - 1;
+ if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
+ SetPageUptodate(page);
+ return 0;
+}
+
+/*
+ * helper function to unlock a page if all the extents in the tree
+ * for that page are unlocked
+ */
+static int check_page_locked(struct extent_io_tree *tree,
+ struct page *page)
+{
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 end = start + PAGE_CACHE_SIZE - 1;
+ if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
+ unlock_page(page);
+ return 0;
+}
+
+/*
+ * helper function to end page writeback if all the extents
+ * in the tree for that page are done with writeback
+ */
+static int check_page_writeback(struct extent_io_tree *tree,
+ struct page *page)
+{
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 end = start + PAGE_CACHE_SIZE - 1;
+ if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
+ end_page_writeback(page);
+ return 0;
+}
+
+/* lots and lots of room for performance fixes in the end_bio funcs */
+
+/*
+ * after a writepage IO is done, we need to:
+ * clear the uptodate bits on error
+ * clear the writeback bits in the extent tree for this IO
+ * end_page_writeback if the page has no more pending IO
+ *
+ * Scheduling is not allowed, so the extent state tree is expected
+ * to have one and only one object corresponding to this IO.
+ */
+static void end_bio_extent_writepage(struct bio *bio, int err)
+{
+ int uptodate = err == 0;
+ struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+ struct extent_io_tree *tree;
+ u64 start;
+ u64 end;
+ int whole_page;
+ int ret;
+
+ do {
+ struct page *page = bvec->bv_page;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+
+ start = ((u64)page->index << PAGE_CACHE_SHIFT) +
+ bvec->bv_offset;
+ end = start + bvec->bv_len - 1;
+
+ if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
+ whole_page = 1;
+ else
+ whole_page = 0;
+
+ if (--bvec >= bio->bi_io_vec)
+ prefetchw(&bvec->bv_page->flags);
+ if (tree->ops && tree->ops->writepage_end_io_hook) {
+ ret = tree->ops->writepage_end_io_hook(page, start,
+ end, NULL, uptodate);
+ if (ret)
+ uptodate = 0;
+ }
+
+ if (!uptodate && tree->ops &&
+ tree->ops->writepage_io_failed_hook) {
+ ret = tree->ops->writepage_io_failed_hook(bio, page,
+ start, end, NULL);
+ if (ret == 0) {
+ uptodate = (err == 0);
+ continue;
+ }
+ }
+
+ if (!uptodate) {
+ clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
+ ClearPageUptodate(page);
+ SetPageError(page);
+ }
+
+ clear_extent_writeback(tree, start, end, GFP_ATOMIC);
+
+ if (whole_page)
+ end_page_writeback(page);
+ else
+ check_page_writeback(tree, page);
+ } while (bvec >= bio->bi_io_vec);
+
+ bio_put(bio);
+}
+
+/*
+ * after a readpage IO is done, we need to:
+ * clear the uptodate bits on error
+ * set the uptodate bits if things worked
+ * set the page up to date if all extents in the tree are uptodate
+ * clear the lock bit in the extent tree
+ * unlock the page if there are no other extents locked for it
+ *
+ * Scheduling is not allowed, so the extent state tree is expected
+ * to have one and only one object corresponding to this IO.
+ */
+static void end_bio_extent_readpage(struct bio *bio, int err)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+ struct extent_io_tree *tree;
+ u64 start;
+ u64 end;
+ int whole_page;
+ int ret;
+
+ do {
+ struct page *page = bvec->bv_page;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+
+ start = ((u64)page->index << PAGE_CACHE_SHIFT) +
+ bvec->bv_offset;
+ end = start + bvec->bv_len - 1;
+
+ if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
+ whole_page = 1;
+ else
+ whole_page = 0;
+
+ if (--bvec >= bio->bi_io_vec)
+ prefetchw(&bvec->bv_page->flags);
+
+ if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
+ ret = tree->ops->readpage_end_io_hook(page, start, end,
+ NULL);
+ if (ret)
+ uptodate = 0;
+ }
+ if (!uptodate && tree->ops &&
+ tree->ops->readpage_io_failed_hook) {
+ ret = tree->ops->readpage_io_failed_hook(bio, page,
+ start, end, NULL);
+ if (ret == 0) {
+ uptodate =
+ test_bit(BIO_UPTODATE, &bio->bi_flags);
+ continue;
+ }
+ }
+
+ if (uptodate) {
+ set_extent_uptodate(tree, start, end,
+ GFP_ATOMIC);
+ }
+ unlock_extent(tree, start, end, GFP_ATOMIC);
+
+ if (whole_page) {
+ if (uptodate) {
+ SetPageUptodate(page);
+ } else {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ }
+ unlock_page(page);
+ } else {
+ if (uptodate) {
+ check_page_uptodate(tree, page);
+ } else {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ }
+ check_page_locked(tree, page);
+ }
+ } while (bvec >= bio->bi_io_vec);
+
+ bio_put(bio);
+}
+
+/*
+ * IO done from prepare_write is pretty simple, we just unlock
+ * the structs in the extent tree when done, and set the uptodate bits
+ * as appropriate.
+ */
+static void end_bio_extent_preparewrite(struct bio *bio, int err)
+{
+ const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+ struct extent_io_tree *tree;
+ u64 start;
+ u64 end;
+
+ do {
+ struct page *page = bvec->bv_page;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+
+ start = ((u64)page->index << PAGE_CACHE_SHIFT) +
+ bvec->bv_offset;
+ end = start + bvec->bv_len - 1;
+
+ if (--bvec >= bio->bi_io_vec)
+ prefetchw(&bvec->bv_page->flags);
+
+ if (uptodate) {
+ set_extent_uptodate(tree, start, end, GFP_ATOMIC);
+ } else {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ }
+
+ unlock_extent(tree, start, end, GFP_ATOMIC);
+
+ } while (bvec >= bio->bi_io_vec);
+
+ bio_put(bio);
+}
+
+static struct bio *
+extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
+ gfp_t gfp_flags)
+{
+ struct bio *bio;
+
+ bio = bio_alloc(gfp_flags, nr_vecs);
+
+ if (bio == NULL && (current->flags & PF_MEMALLOC)) {
+ while (!bio && (nr_vecs /= 2))
+ bio = bio_alloc(gfp_flags, nr_vecs);
+ }
+
+ if (bio) {
+ bio->bi_size = 0;
+ bio->bi_bdev = bdev;
+ bio->bi_sector = first_sector;
+ }
+ return bio;
+}
+
+static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
+ unsigned long bio_flags)
+{
+ int ret = 0;
+ struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+ struct page *page = bvec->bv_page;
+ struct extent_io_tree *tree = bio->bi_private;
+ u64 start;
+ u64 end;
+
+ start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
+ end = start + bvec->bv_len - 1;
+
+ bio->bi_private = NULL;
+
+ bio_get(bio);
+
+ if (tree->ops && tree->ops->submit_bio_hook)
+ tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
+ mirror_num, bio_flags);
+ else
+ submit_bio(rw, bio);
+ if (bio_flagged(bio, BIO_EOPNOTSUPP))
+ ret = -EOPNOTSUPP;
+ bio_put(bio);
+ return ret;
+}
+
+static int submit_extent_page(int rw, struct extent_io_tree *tree,
+ struct page *page, sector_t sector,
+ size_t size, unsigned long offset,
+ struct block_device *bdev,
+ struct bio **bio_ret,
+ unsigned long max_pages,
+ bio_end_io_t end_io_func,
+ int mirror_num,
+ unsigned long prev_bio_flags,
+ unsigned long bio_flags)
+{
+ int ret = 0;
+ struct bio *bio;
+ int nr;
+ int contig = 0;
+ int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
+ int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
+ size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
+
+ if (bio_ret && *bio_ret) {
+ bio = *bio_ret;
+ if (old_compressed)
+ contig = bio->bi_sector == sector;
+ else
+ contig = bio->bi_sector + (bio->bi_size >> 9) ==
+ sector;
+
+ if (prev_bio_flags != bio_flags || !contig ||
+ (tree->ops && tree->ops->merge_bio_hook &&
+ tree->ops->merge_bio_hook(page, offset, page_size, bio,
+ bio_flags)) ||
+ bio_add_page(bio, page, page_size, offset) < page_size) {
+ ret = submit_one_bio(rw, bio, mirror_num,
+ prev_bio_flags);
+ bio = NULL;
+ } else {
+ return 0;
+ }
+ }
+ if (this_compressed)
+ nr = BIO_MAX_PAGES;
+ else
+ nr = bio_get_nr_vecs(bdev);
+
+ bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
+ if (!bio) {
+ printk("failed to allocate bio nr %d\n", nr);
+ }
+
+ bio_add_page(bio, page, page_size, offset);
+ bio->bi_end_io = end_io_func;
+ bio->bi_private = tree;
+
+ if (bio_ret) {
+ *bio_ret = bio;
+ } else {
+ ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
+ }
+
+ return ret;
+}
+
+void set_page_extent_mapped(struct page *page)
+{
+ if (!PagePrivate(page)) {
+ SetPagePrivate(page);
+ page_cache_get(page);
+ set_page_private(page, EXTENT_PAGE_PRIVATE);
+ }
+}
+EXPORT_SYMBOL(set_page_extent_mapped);
+
+void set_page_extent_head(struct page *page, unsigned long len)
+{
+ set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
+}
+
+/*
+ * basic readpage implementation. Locked extent state structs are inserted
+ * into the tree that are removed when the IO is done (by the end_io
+ * handlers)
+ */
+static int __extent_read_full_page(struct extent_io_tree *tree,
+ struct page *page,
+ get_extent_t *get_extent,
+ struct bio **bio, int mirror_num,
+ unsigned long *bio_flags)
+{
+ struct inode *inode = page->mapping->host;
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 page_end = start + PAGE_CACHE_SIZE - 1;
+ u64 end;
+ u64 cur = start;
+ u64 extent_offset;
+ u64 last_byte = i_size_read(inode);
+ u64 block_start;
+ u64 cur_end;
+ sector_t sector;
+ struct extent_map *em;
+ struct block_device *bdev;
+ int ret;
+ int nr = 0;
+ size_t page_offset = 0;
+ size_t iosize;
+ size_t disk_io_size;
+ size_t blocksize = inode->i_sb->s_blocksize;
+ unsigned long this_bio_flag = 0;
+
+ set_page_extent_mapped(page);
+
+ end = page_end;
+ lock_extent(tree, start, end, GFP_NOFS);
+
+ if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
+ char *userpage;
+ size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
+
+ if (zero_offset) {
+ iosize = PAGE_CACHE_SIZE - zero_offset;
+ userpage = kmap_atomic(page, KM_USER0);
+ memset(userpage + zero_offset, 0, iosize);
+ flush_dcache_page(page);
+ kunmap_atomic(userpage, KM_USER0);
+ }
+ }
+ while (cur <= end) {
+ if (cur >= last_byte) {
+ char *userpage;
+ iosize = PAGE_CACHE_SIZE - page_offset;
+ userpage = kmap_atomic(page, KM_USER0);
+ memset(userpage + page_offset, 0, iosize);
+ flush_dcache_page(page);
+ kunmap_atomic(userpage, KM_USER0);
+ set_extent_uptodate(tree, cur, cur + iosize - 1,
+ GFP_NOFS);
+ unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+ break;
+ }
+ em = get_extent(inode, page, page_offset, cur,
+ end - cur + 1, 0);
+ if (IS_ERR(em) || !em) {
+ SetPageError(page);
+ unlock_extent(tree, cur, end, GFP_NOFS);
+ break;
+ }
+ extent_offset = cur - em->start;
+ if (extent_map_end(em) <= cur) {
+printk("bad mapping em [%Lu %Lu] cur %Lu\n", em->start, extent_map_end(em), cur);
+ }
+ BUG_ON(extent_map_end(em) <= cur);
+ if (end < cur) {
+printk("2bad mapping end %Lu cur %Lu\n", end, cur);
+ }
+ BUG_ON(end < cur);
+
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+ this_bio_flag = EXTENT_BIO_COMPRESSED;
+
+ iosize = min(extent_map_end(em) - cur, end - cur + 1);
+ cur_end = min(extent_map_end(em) - 1, end);
+ iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
+ if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
+ disk_io_size = em->block_len;
+ sector = em->block_start >> 9;
+ } else {
+ sector = (em->block_start + extent_offset) >> 9;
+ disk_io_size = iosize;
+ }
+ bdev = em->bdev;
+ block_start = em->block_start;
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ block_start = EXTENT_MAP_HOLE;
+ free_extent_map(em);
+ em = NULL;
+
+ /* we've found a hole, just zero and go on */
+ if (block_start == EXTENT_MAP_HOLE) {
+ char *userpage;
+ userpage = kmap_atomic(page, KM_USER0);
+ memset(userpage + page_offset, 0, iosize);
+ flush_dcache_page(page);
+ kunmap_atomic(userpage, KM_USER0);
+
+ set_extent_uptodate(tree, cur, cur + iosize - 1,
+ GFP_NOFS);
+ unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+ cur = cur + iosize;
+ page_offset += iosize;
+ continue;
+ }
+ /* the get_extent function already copied into the page */
+ if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
+ check_page_uptodate(tree, page);
+ unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+ cur = cur + iosize;
+ page_offset += iosize;
+ continue;
+ }
+ /* we have an inline extent but it didn't get marked up
+ * to date. Error out
+ */
+ if (block_start == EXTENT_MAP_INLINE) {
+ SetPageError(page);
+ unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+ cur = cur + iosize;
+ page_offset += iosize;
+ continue;
+ }
+
+ ret = 0;
+ if (tree->ops && tree->ops->readpage_io_hook) {
+ ret = tree->ops->readpage_io_hook(page, cur,
+ cur + iosize - 1);
+ }
+ if (!ret) {
+ unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
+ pnr -= page->index;
+ ret = submit_extent_page(READ, tree, page,
+ sector, disk_io_size, page_offset,
+ bdev, bio, pnr,
+ end_bio_extent_readpage, mirror_num,
+ *bio_flags,
+ this_bio_flag);
+ nr++;
+ *bio_flags = this_bio_flag;
+ }
+ if (ret)
+ SetPageError(page);
+ cur = cur + iosize;
+ page_offset += iosize;
+ }
+ if (!nr) {
+ if (!PageError(page))
+ SetPageUptodate(page);
+ unlock_page(page);
+ }
+ return 0;
+}
+
+int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
+ get_extent_t *get_extent)
+{
+ struct bio *bio = NULL;
+ unsigned long bio_flags = 0;
+ int ret;
+
+ ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
+ &bio_flags);
+ if (bio)
+ submit_one_bio(READ, bio, 0, bio_flags);
+ return ret;
+}
+EXPORT_SYMBOL(extent_read_full_page);
+
+/*
+ * the writepage semantics are similar to regular writepage. extent
+ * records are inserted to lock ranges in the tree, and as dirty areas
+ * are found, they are marked writeback. Then the lock bits are removed
+ * and the end_io handler clears the writeback ranges
+ */
+static int __extent_writepage(struct page *page, struct writeback_control *wbc,
+ void *data)
+{
+ struct inode *inode = page->mapping->host;
+ struct extent_page_data *epd = data;
+ struct extent_io_tree *tree = epd->tree;
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 delalloc_start;
+ u64 page_end = start + PAGE_CACHE_SIZE - 1;
+ u64 end;
+ u64 cur = start;
+ u64 extent_offset;
+ u64 last_byte = i_size_read(inode);
+ u64 block_start;
+ u64 iosize;
+ u64 unlock_start;
+ sector_t sector;
+ struct extent_map *em;
+ struct block_device *bdev;
+ int ret;
+ int nr = 0;
+ size_t pg_offset = 0;
+ size_t blocksize;
+ loff_t i_size = i_size_read(inode);
+ unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
+ u64 nr_delalloc;
+ u64 delalloc_end;
+ int page_started;
+ int compressed;
+ unsigned long nr_written = 0;
+
+ WARN_ON(!PageLocked(page));
+ pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
+ if (page->index > end_index ||
+ (page->index == end_index && !pg_offset)) {
+ page->mapping->a_ops->invalidatepage(page, 0);
+ unlock_page(page);
+ return 0;
+ }
+
+ if (page->index == end_index) {
+ char *userpage;
+
+ userpage = kmap_atomic(page, KM_USER0);
+ memset(userpage + pg_offset, 0,
+ PAGE_CACHE_SIZE - pg_offset);
+ kunmap_atomic(userpage, KM_USER0);
+ flush_dcache_page(page);
+ }
+ pg_offset = 0;
+
+ set_page_extent_mapped(page);
+
+ delalloc_start = start;
+ delalloc_end = 0;
+ page_started = 0;
+ if (!epd->extent_locked) {
+ while(delalloc_end < page_end) {
+ nr_delalloc = find_lock_delalloc_range(inode, tree,
+ page,
+ &delalloc_start,
+ &delalloc_end,
+ 128 * 1024 * 1024);
+ if (nr_delalloc == 0) {
+ delalloc_start = delalloc_end + 1;
+ continue;
+ }
+ tree->ops->fill_delalloc(inode, page, delalloc_start,
+ delalloc_end, &page_started,
+ &nr_written);
+ delalloc_start = delalloc_end + 1;
+ }
+
+ /* did the fill delalloc function already unlock and start
+ * the IO?
+ */
+ if (page_started) {
+ ret = 0;
+ goto update_nr_written;
+ }
+ }
+ lock_extent(tree, start, page_end, GFP_NOFS);
+
+ unlock_start = start;
+
+ if (tree->ops && tree->ops->writepage_start_hook) {
+ ret = tree->ops->writepage_start_hook(page, start,
+ page_end);
+ if (ret == -EAGAIN) {
+ unlock_extent(tree, start, page_end, GFP_NOFS);
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ ret = 0;
+ goto update_nr_written;
+ }
+ }
+
+ nr_written++;
+
+ end = page_end;
+ if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
+ printk("found delalloc bits after lock_extent\n");
+ }
+
+ if (last_byte <= start) {
+ clear_extent_dirty(tree, start, page_end, GFP_NOFS);
+ unlock_extent(tree, start, page_end, GFP_NOFS);
+ if (tree->ops && tree->ops->writepage_end_io_hook)
+ tree->ops->writepage_end_io_hook(page, start,
+ page_end, NULL, 1);
+ unlock_start = page_end + 1;
+ goto done;
+ }
+
+ set_extent_uptodate(tree, start, page_end, GFP_NOFS);
+ blocksize = inode->i_sb->s_blocksize;
+
+ while (cur <= end) {
+ if (cur >= last_byte) {
+ clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
+ unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
+ if (tree->ops && tree->ops->writepage_end_io_hook)
+ tree->ops->writepage_end_io_hook(page, cur,
+ page_end, NULL, 1);
+ unlock_start = page_end + 1;
+ break;
+ }
+ em = epd->get_extent(inode, page, pg_offset, cur,
+ end - cur + 1, 1);
+ if (IS_ERR(em) || !em) {
+ SetPageError(page);
+ break;
+ }
+
+ extent_offset = cur - em->start;
+ BUG_ON(extent_map_end(em) <= cur);
+ BUG_ON(end < cur);
+ iosize = min(extent_map_end(em) - cur, end - cur + 1);
+ iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
+ sector = (em->block_start + extent_offset) >> 9;
+ bdev = em->bdev;
+ block_start = em->block_start;
+ compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ free_extent_map(em);
+ em = NULL;
+
+ /*
+ * compressed and inline extents are written through other
+ * paths in the FS
+ */
+ if (compressed || block_start == EXTENT_MAP_HOLE ||
+ block_start == EXTENT_MAP_INLINE) {
+ clear_extent_dirty(tree, cur,
+ cur + iosize - 1, GFP_NOFS);
+
+ unlock_extent(tree, unlock_start, cur + iosize -1,
+ GFP_NOFS);
+
+ /*
+ * end_io notification does not happen here for
+ * compressed extents
+ */
+ if (!compressed && tree->ops &&
+ tree->ops->writepage_end_io_hook)
+ tree->ops->writepage_end_io_hook(page, cur,
+ cur + iosize - 1,
+ NULL, 1);
+ else if (compressed) {
+ /* we don't want to end_page_writeback on
+ * a compressed extent. this happens
+ * elsewhere
+ */
+ nr++;
+ }
+
+ cur += iosize;
+ pg_offset += iosize;
+ unlock_start = cur;
+ continue;
+ }
+ /* leave this out until we have a page_mkwrite call */
+ if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
+ EXTENT_DIRTY, 0)) {
+ cur = cur + iosize;
+ pg_offset += iosize;
+ continue;
+ }
+
+ clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
+ if (tree->ops && tree->ops->writepage_io_hook) {
+ ret = tree->ops->writepage_io_hook(page, cur,
+ cur + iosize - 1);
+ } else {
+ ret = 0;
+ }
+ if (ret) {
+ SetPageError(page);
+ } else {
+ unsigned long max_nr = end_index + 1;
+
+ set_range_writeback(tree, cur, cur + iosize - 1);
+ if (!PageWriteback(page)) {
+ printk("warning page %lu not writeback, "
+ "cur %llu end %llu\n", page->index,
+ (unsigned long long)cur,
+ (unsigned long long)end);
+ }
+
+ ret = submit_extent_page(WRITE, tree, page, sector,
+ iosize, pg_offset, bdev,
+ &epd->bio, max_nr,
+ end_bio_extent_writepage,
+ 0, 0, 0);
+ if (ret)
+ SetPageError(page);
+ }
+ cur = cur + iosize;
+ pg_offset += iosize;
+ nr++;
+ }
+done:
+ if (nr == 0) {
+ /* make sure the mapping tag for page dirty gets cleared */
+ set_page_writeback(page);
+ end_page_writeback(page);
+ }
+ if (unlock_start <= page_end)
+ unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
+ unlock_page(page);
+
+update_nr_written:
+ wbc->nr_to_write -= nr_written;
+ if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
+ wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
+ page->mapping->writeback_index = page->index + nr_written;
+ return 0;
+}
+
+/**
+ * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
+ * @mapping: address space structure to write
+ * @wbc: subtract the number of written pages from *@wbc->nr_to_write
+ * @writepage: function called for each page
+ * @data: data passed to writepage function
+ *
+ * If a page is already under I/O, write_cache_pages() skips it, even
+ * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
+ * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
+ * and msync() need to guarantee that all the data which was dirty at the time
+ * the call was made get new I/O started against them. If wbc->sync_mode is
+ * WB_SYNC_ALL then we were called for data integrity and we must wait for
+ * existing IO to complete.
+ */
+int extent_write_cache_pages(struct extent_io_tree *tree,
+ struct address_space *mapping,
+ struct writeback_control *wbc,
+ writepage_t writepage, void *data,
+ void (*flush_fn)(void *))
+{
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+ int ret = 0;
+ int done = 0;
+ struct pagevec pvec;
+ int nr_pages;
+ pgoff_t index;
+ pgoff_t end; /* Inclusive */
+ int scanned = 0;
+ int range_whole = 0;
+
+ if (wbc->nonblocking && bdi_write_congested(bdi)) {
+ wbc->encountered_congestion = 1;
+ return 0;
+ }
+
+ pagevec_init(&pvec, 0);
+ if (wbc->range_cyclic) {
+ index = mapping->writeback_index; /* Start from prev offset */
+ end = -1;
+ } else {
+ index = wbc->range_start >> PAGE_CACHE_SHIFT;
+ end = wbc->range_end >> PAGE_CACHE_SHIFT;
+ if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
+ range_whole = 1;
+ scanned = 1;
+ }
+retry:
+ while (!done && (index <= end) &&
+ (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+ PAGECACHE_TAG_DIRTY,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
+ unsigned i;
+
+ scanned = 1;
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pvec.pages[i];
+
+ /*
+ * At this point we hold neither mapping->tree_lock nor
+ * lock on the page itself: the page may be truncated or
+ * invalidated (changing page->mapping to NULL), or even
+ * swizzled back from swapper_space to tmpfs file
+ * mapping
+ */
+ if (tree->ops && tree->ops->write_cache_pages_lock_hook)
+ tree->ops->write_cache_pages_lock_hook(page);
+ else
+ lock_page(page);
+
+ if (unlikely(page->mapping != mapping)) {
+ unlock_page(page);
+ continue;
+ }
+
+ if (!wbc->range_cyclic && page->index > end) {
+ done = 1;
+ unlock_page(page);
+ continue;
+ }
+
+ if (wbc->sync_mode != WB_SYNC_NONE) {
+ flush_fn(data);
+ wait_on_page_writeback(page);
+ }
+
+ if (PageWriteback(page) ||
+ !clear_page_dirty_for_io(page)) {
+ unlock_page(page);
+ continue;
+ }
+
+ ret = (*writepage)(page, wbc, data);
+
+ if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
+ unlock_page(page);
+ ret = 0;
+ }
+ if (ret || wbc->nr_to_write <= 0)
+ done = 1;
+ if (wbc->nonblocking && bdi_write_congested(bdi)) {
+ wbc->encountered_congestion = 1;
+ done = 1;
+ }
+ }
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+ if (!scanned && !done) {
+ /*
+ * We hit the last page and there is more work to be done: wrap
+ * back to the start of the file
+ */
+ scanned = 1;
+ index = 0;
+ goto retry;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(extent_write_cache_pages);
+
+static noinline void flush_write_bio(void *data)
+{
+ struct extent_page_data *epd = data;
+ if (epd->bio) {
+ submit_one_bio(WRITE, epd->bio, 0, 0);
+ epd->bio = NULL;
+ }
+}
+
+int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
+ get_extent_t *get_extent,
+ struct writeback_control *wbc)
+{
+ int ret;
+ struct address_space *mapping = page->mapping;
+ struct extent_page_data epd = {
+ .bio = NULL,
+ .tree = tree,
+ .get_extent = get_extent,
+ .extent_locked = 0,
+ };
+ struct writeback_control wbc_writepages = {
+ .bdi = wbc->bdi,
+ .sync_mode = WB_SYNC_NONE,
+ .older_than_this = NULL,
+ .nr_to_write = 64,
+ .range_start = page_offset(page) + PAGE_CACHE_SIZE,
+ .range_end = (loff_t)-1,
+ };
+
+
+ ret = __extent_writepage(page, wbc, &epd);
+
+ extent_write_cache_pages(tree, mapping, &wbc_writepages,
+ __extent_writepage, &epd, flush_write_bio);
+ if (epd.bio) {
+ submit_one_bio(WRITE, epd.bio, 0, 0);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(extent_write_full_page);
+
+int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
+ u64 start, u64 end, get_extent_t *get_extent,
+ int mode)
+{
+ int ret = 0;
+ struct address_space *mapping = inode->i_mapping;
+ struct page *page;
+ unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+
+ struct extent_page_data epd = {
+ .bio = NULL,
+ .tree = tree,
+ .get_extent = get_extent,
+ .extent_locked = 1,
+ };
+ struct writeback_control wbc_writepages = {
+ .bdi = inode->i_mapping->backing_dev_info,
+ .sync_mode = mode,
+ .older_than_this = NULL,
+ .nr_to_write = nr_pages * 2,
+ .range_start = start,
+ .range_end = end + 1,
+ };
+
+ while(start <= end) {
+ page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
+ if (clear_page_dirty_for_io(page))
+ ret = __extent_writepage(page, &wbc_writepages, &epd);
+ else {
+ if (tree->ops && tree->ops->writepage_end_io_hook)
+ tree->ops->writepage_end_io_hook(page, start,
+ start + PAGE_CACHE_SIZE - 1,
+ NULL, 1);
+ unlock_page(page);
+ }
+ page_cache_release(page);
+ start += PAGE_CACHE_SIZE;
+ }
+
+ if (epd.bio)
+ submit_one_bio(WRITE, epd.bio, 0, 0);
+ return ret;
+}
+EXPORT_SYMBOL(extent_write_locked_range);
+
+
+int extent_writepages(struct extent_io_tree *tree,
+ struct address_space *mapping,
+ get_extent_t *get_extent,
+ struct writeback_control *wbc)
+{
+ int ret = 0;
+ struct extent_page_data epd = {
+ .bio = NULL,
+ .tree = tree,
+ .get_extent = get_extent,
+ .extent_locked = 0,
+ };
+
+ ret = extent_write_cache_pages(tree, mapping, wbc,
+ __extent_writepage, &epd,
+ flush_write_bio);
+ if (epd.bio) {
+ submit_one_bio(WRITE, epd.bio, 0, 0);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(extent_writepages);
+
+int extent_readpages(struct extent_io_tree *tree,
+ struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages,
+ get_extent_t get_extent)
+{
+ struct bio *bio = NULL;
+ unsigned page_idx;
+ struct pagevec pvec;
+ unsigned long bio_flags = 0;
+
+ pagevec_init(&pvec, 0);
+ for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+ struct page *page = list_entry(pages->prev, struct page, lru);
+
+ prefetchw(&page->flags);
+ list_del(&page->lru);
+ /*
+ * what we want to do here is call add_to_page_cache_lru,
+ * but that isn't exported, so we reproduce it here
+ */
+ if (!add_to_page_cache(page, mapping,
+ page->index, GFP_KERNEL)) {
+
+ /* open coding of lru_cache_add, also not exported */
+ page_cache_get(page);
+ if (!pagevec_add(&pvec, page))
+ __pagevec_lru_add(&pvec);
+ __extent_read_full_page(tree, page, get_extent,
+ &bio, 0, &bio_flags);
+ }
+ page_cache_release(page);
+ }
+ if (pagevec_count(&pvec))
+ __pagevec_lru_add(&pvec);
+ BUG_ON(!list_empty(pages));
+ if (bio)
+ submit_one_bio(READ, bio, 0, bio_flags);
+ return 0;
+}
+EXPORT_SYMBOL(extent_readpages);
+
+/*
+ * basic invalidatepage code, this waits on any locked or writeback
+ * ranges corresponding to the page, and then deletes any extent state
+ * records from the tree
+ */
+int extent_invalidatepage(struct extent_io_tree *tree,
+ struct page *page, unsigned long offset)
+{
+ u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
+ u64 end = start + PAGE_CACHE_SIZE - 1;
+ size_t blocksize = page->mapping->host->i_sb->s_blocksize;
+
+ start += (offset + blocksize -1) & ~(blocksize - 1);
+ if (start > end)
+ return 0;
+
+ lock_extent(tree, start, end, GFP_NOFS);
+ wait_on_extent_writeback(tree, start, end);
+ clear_extent_bit(tree, start, end,
+ EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
+ 1, 1, GFP_NOFS);
+ return 0;
+}
+EXPORT_SYMBOL(extent_invalidatepage);
+
+/*
+ * simple commit_write call, set_range_dirty is used to mark both
+ * the pages and the extent records as dirty
+ */
+int extent_commit_write(struct extent_io_tree *tree,
+ struct inode *inode, struct page *page,
+ unsigned from, unsigned to)
+{
+ loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+ set_page_extent_mapped(page);
+ set_page_dirty(page);
+
+ if (pos > inode->i_size) {
+ i_size_write(inode, pos);
+ mark_inode_dirty(inode);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(extent_commit_write);
+
+int extent_prepare_write(struct extent_io_tree *tree,
+ struct inode *inode, struct page *page,
+ unsigned from, unsigned to, get_extent_t *get_extent)
+{
+ u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
+ u64 block_start;
+ u64 orig_block_start;
+ u64 block_end;
+ u64 cur_end;
+ struct extent_map *em;
+ unsigned blocksize = 1 << inode->i_blkbits;
+ size_t page_offset = 0;
+ size_t block_off_start;
+ size_t block_off_end;
+ int err = 0;
+ int iocount = 0;
+ int ret = 0;
+ int isnew;
+
+ set_page_extent_mapped(page);
+
+ block_start = (page_start + from) & ~((u64)blocksize - 1);
+ block_end = (page_start + to - 1) | (blocksize - 1);
+ orig_block_start = block_start;
+
+ lock_extent(tree, page_start, page_end, GFP_NOFS);
+ while(block_start <= block_end) {
+ em = get_extent(inode, page, page_offset, block_start,
+ block_end - block_start + 1, 1);
+ if (IS_ERR(em) || !em) {
+ goto err;
+ }
+ cur_end = min(block_end, extent_map_end(em) - 1);
+ block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
+ block_off_end = block_off_start + blocksize;
+ isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
+
+ if (!PageUptodate(page) && isnew &&
+ (block_off_end > to || block_off_start < from)) {
+ void *kaddr;
+
+ kaddr = kmap_atomic(page, KM_USER0);
+ if (block_off_end > to)
+ memset(kaddr + to, 0, block_off_end - to);
+ if (block_off_start < from)
+ memset(kaddr + block_off_start, 0,
+ from - block_off_start);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+ if ((em->block_start != EXTENT_MAP_HOLE &&
+ em->block_start != EXTENT_MAP_INLINE) &&
+ !isnew && !PageUptodate(page) &&
+ (block_off_end > to || block_off_start < from) &&
+ !test_range_bit(tree, block_start, cur_end,
+ EXTENT_UPTODATE, 1)) {
+ u64 sector;
+ u64 extent_offset = block_start - em->start;
+ size_t iosize;
+ sector = (em->block_start + extent_offset) >> 9;
+ iosize = (cur_end - block_start + blocksize) &
+ ~((u64)blocksize - 1);
+ /*
+ * we've already got the extent locked, but we
+ * need to split the state such that our end_bio
+ * handler can clear the lock.
+ */
+ set_extent_bit(tree, block_start,
+ block_start + iosize - 1,
+ EXTENT_LOCKED, 0, NULL, GFP_NOFS);
+ ret = submit_extent_page(READ, tree, page,
+ sector, iosize, page_offset, em->bdev,
+ NULL, 1,
+ end_bio_extent_preparewrite, 0,
+ 0, 0);
+ iocount++;
+ block_start = block_start + iosize;
+ } else {
+ set_extent_uptodate(tree, block_start, cur_end,
+ GFP_NOFS);
+ unlock_extent(tree, block_start, cur_end, GFP_NOFS);
+ block_start = cur_end + 1;
+ }
+ page_offset = block_start & (PAGE_CACHE_SIZE - 1);
+ free_extent_map(em);
+ }
+ if (iocount) {
+ wait_extent_bit(tree, orig_block_start,
+ block_end, EXTENT_LOCKED);
+ }
+ check_page_uptodate(tree, page);
+err:
+ /* FIXME, zero out newly allocated blocks on error */
+ return err;
+}
+EXPORT_SYMBOL(extent_prepare_write);
+
+/*
+ * a helper for releasepage, this tests for areas of the page that
+ * are locked or under IO and drops the related state bits if it is safe
+ * to drop the page.
+ */
+int try_release_extent_state(struct extent_map_tree *map,
+ struct extent_io_tree *tree, struct page *page,
+ gfp_t mask)
+{
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 end = start + PAGE_CACHE_SIZE - 1;
+ int ret = 1;
+
+ if (test_range_bit(tree, start, end,
+ EXTENT_IOBITS | EXTENT_ORDERED, 0))
+ ret = 0;
+ else {
+ if ((mask & GFP_NOFS) == GFP_NOFS)
+ mask = GFP_NOFS;
+ clear_extent_bit(tree, start, end, EXTENT_UPTODATE,
+ 1, 1, mask);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(try_release_extent_state);
+
+/*
+ * a helper for releasepage. As long as there are no locked extents
+ * in the range corresponding to the page, both state records and extent
+ * map records are removed
+ */
+int try_release_extent_mapping(struct extent_map_tree *map,
+ struct extent_io_tree *tree, struct page *page,
+ gfp_t mask)
+{
+ struct extent_map *em;
+ u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 end = start + PAGE_CACHE_SIZE - 1;
+
+ if ((mask & __GFP_WAIT) &&
+ page->mapping->host->i_size > 16 * 1024 * 1024) {
+ u64 len;
+ while (start <= end) {
+ len = end - start + 1;
+ spin_lock(&map->lock);
+ em = lookup_extent_mapping(map, start, len);
+ if (!em || IS_ERR(em)) {
+ spin_unlock(&map->lock);
+ break;
+ }
+ if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
+ em->start != start) {
+ spin_unlock(&map->lock);
+ free_extent_map(em);
+ break;
+ }
+ if (!test_range_bit(tree, em->start,
+ extent_map_end(em) - 1,
+ EXTENT_LOCKED | EXTENT_WRITEBACK |
+ EXTENT_ORDERED,
+ 0)) {
+ remove_extent_mapping(map, em);
+ /* once for the rb tree */
+ free_extent_map(em);
+ }
+ start = extent_map_end(em);
+ spin_unlock(&map->lock);
+
+ /* once for us */
+ free_extent_map(em);
+ }
+ }
+ return try_release_extent_state(map, tree, page, mask);
+}
+EXPORT_SYMBOL(try_release_extent_mapping);
+
+sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
+ get_extent_t *get_extent)
+{
+ struct inode *inode = mapping->host;
+ u64 start = iblock << inode->i_blkbits;
+ sector_t sector = 0;
+ size_t blksize = (1 << inode->i_blkbits);
+ struct extent_map *em;
+
+ lock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
+ GFP_NOFS);
+ em = get_extent(inode, NULL, 0, start, blksize, 0);
+ unlock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
+ GFP_NOFS);
+ if (!em || IS_ERR(em))
+ return 0;
+
+ if (em->block_start > EXTENT_MAP_LAST_BYTE)
+ goto out;
+
+ sector = (em->block_start + start - em->start) >> inode->i_blkbits;
+out:
+ free_extent_map(em);
+ return sector;
+}
+
+static inline struct page *extent_buffer_page(struct extent_buffer *eb,
+ unsigned long i)
+{
+ struct page *p;
+ struct address_space *mapping;
+
+ if (i == 0)
+ return eb->first_page;
+ i += eb->start >> PAGE_CACHE_SHIFT;
+ mapping = eb->first_page->mapping;
+ if (!mapping)
+ return NULL;
+
+ /*
+ * extent_buffer_page is only called after pinning the page
+ * by increasing the reference count. So we know the page must
+ * be in the radix tree.
+ */
+ rcu_read_lock();
+ p = radix_tree_lookup(&mapping->page_tree, i);
+ rcu_read_unlock();
+
+ return p;
+}
+
+static inline unsigned long num_extent_pages(u64 start, u64 len)
+{
+ return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
+ (start >> PAGE_CACHE_SHIFT);
+}
+
+static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
+ u64 start,
+ unsigned long len,
+ gfp_t mask)
+{
+ struct extent_buffer *eb = NULL;
+#ifdef LEAK_DEBUG
+ unsigned long flags;
+#endif
+
+ eb = kmem_cache_zalloc(extent_buffer_cache, mask);
+ eb->start = start;
+ eb->len = len;
+ mutex_init(&eb->mutex);
+#ifdef LEAK_DEBUG
+ spin_lock_irqsave(&leak_lock, flags);
+ list_add(&eb->leak_list, &buffers);
+ spin_unlock_irqrestore(&leak_lock, flags);
+#endif
+ atomic_set(&eb->refs, 1);
+
+ return eb;
+}
+
+static void __free_extent_buffer(struct extent_buffer *eb)
+{
+#ifdef LEAK_DEBUG
+ unsigned long flags;
+ spin_lock_irqsave(&leak_lock, flags);
+ list_del(&eb->leak_list);
+ spin_unlock_irqrestore(&leak_lock, flags);
+#endif
+ kmem_cache_free(extent_buffer_cache, eb);
+}
+
+struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
+ u64 start, unsigned long len,
+ struct page *page0,
+ gfp_t mask)
+{
+ unsigned long num_pages = num_extent_pages(start, len);
+ unsigned long i;
+ unsigned long index = start >> PAGE_CACHE_SHIFT;
+ struct extent_buffer *eb;
+ struct extent_buffer *exists = NULL;
+ struct page *p;
+ struct address_space *mapping = tree->mapping;
+ int uptodate = 1;
+
+ spin_lock(&tree->buffer_lock);
+ eb = buffer_search(tree, start);
+ if (eb) {
+ atomic_inc(&eb->refs);
+ spin_unlock(&tree->buffer_lock);
+ mark_page_accessed(eb->first_page);
+ return eb;
+ }
+ spin_unlock(&tree->buffer_lock);
+
+ eb = __alloc_extent_buffer(tree, start, len, mask);
+ if (!eb)
+ return NULL;
+
+ if (page0) {
+ eb->first_page = page0;
+ i = 1;
+ index++;
+ page_cache_get(page0);
+ mark_page_accessed(page0);
+ set_page_extent_mapped(page0);
+ set_page_extent_head(page0, len);
+ uptodate = PageUptodate(page0);
+ } else {
+ i = 0;
+ }
+ for (; i < num_pages; i++, index++) {
+ p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
+ if (!p) {
+ WARN_ON(1);
+ goto free_eb;
+ }
+ set_page_extent_mapped(p);
+ mark_page_accessed(p);
+ if (i == 0) {
+ eb->first_page = p;
+ set_page_extent_head(p, len);
+ } else {
+ set_page_private(p, EXTENT_PAGE_PRIVATE);
+ }
+ if (!PageUptodate(p))
+ uptodate = 0;
+ unlock_page(p);
+ }
+ if (uptodate)
+ eb->flags |= EXTENT_UPTODATE;
+ eb->flags |= EXTENT_BUFFER_FILLED;
+
+ spin_lock(&tree->buffer_lock);
+ exists = buffer_tree_insert(tree, start, &eb->rb_node);
+ if (exists) {
+ /* add one reference for the caller */
+ atomic_inc(&exists->refs);
+ spin_unlock(&tree->buffer_lock);
+ goto free_eb;
+ }
+ spin_unlock(&tree->buffer_lock);
+
+ /* add one reference for the tree */
+ atomic_inc(&eb->refs);
+ return eb;
+
+free_eb:
+ if (!atomic_dec_and_test(&eb->refs))
+ return exists;
+ for (index = 1; index < i; index++)
+ page_cache_release(extent_buffer_page(eb, index));
+ page_cache_release(extent_buffer_page(eb, 0));
+ __free_extent_buffer(eb);
+ return exists;
+}
+EXPORT_SYMBOL(alloc_extent_buffer);
+
+struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
+ u64 start, unsigned long len,
+ gfp_t mask)
+{
+ struct extent_buffer *eb;
+
+ spin_lock(&tree->buffer_lock);
+ eb = buffer_search(tree, start);
+ if (eb)
+ atomic_inc(&eb->refs);
+ spin_unlock(&tree->buffer_lock);
+
+ if (eb)
+ mark_page_accessed(eb->first_page);
+
+ return eb;
+}
+EXPORT_SYMBOL(find_extent_buffer);
+
+void free_extent_buffer(struct extent_buffer *eb)
+{
+ if (!eb)
+ return;
+
+ if (!atomic_dec_and_test(&eb->refs))
+ return;
+
+ WARN_ON(1);
+}
+EXPORT_SYMBOL(free_extent_buffer);
+
+int clear_extent_buffer_dirty(struct extent_io_tree *tree,
+ struct extent_buffer *eb)
+{
+ int set;
+ unsigned long i;
+ unsigned long num_pages;
+ struct page *page;
+
+ u64 start = eb->start;
+ u64 end = start + eb->len - 1;
+
+ set = clear_extent_dirty(tree, start, end, GFP_NOFS);
+ num_pages = num_extent_pages(eb->start, eb->len);
+
+ for (i = 0; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ if (!set && !PageDirty(page))
+ continue;
+
+ lock_page(page);
+ if (i == 0)
+ set_page_extent_head(page, eb->len);
+ else
+ set_page_private(page, EXTENT_PAGE_PRIVATE);
+
+ /*
+ * if we're on the last page or the first page and the
+ * block isn't aligned on a page boundary, do extra checks
+ * to make sure we don't clean page that is partially dirty
+ */
+ if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
+ ((i == num_pages - 1) &&
+ ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
+ start = (u64)page->index << PAGE_CACHE_SHIFT;
+ end = start + PAGE_CACHE_SIZE - 1;
+ if (test_range_bit(tree, start, end,
+ EXTENT_DIRTY, 0)) {
+ unlock_page(page);
+ continue;
+ }
+ }
+ clear_page_dirty_for_io(page);
+ spin_lock_irq(&page->mapping->tree_lock);
+ if (!PageDirty(page)) {
+ radix_tree_tag_clear(&page->mapping->page_tree,
+ page_index(page),
+ PAGECACHE_TAG_DIRTY);
+ }
+ spin_unlock_irq(&page->mapping->tree_lock);
+ unlock_page(page);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(clear_extent_buffer_dirty);
+
+int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
+ struct extent_buffer *eb)
+{
+ return wait_on_extent_writeback(tree, eb->start,
+ eb->start + eb->len - 1);
+}
+EXPORT_SYMBOL(wait_on_extent_buffer_writeback);
+
+int set_extent_buffer_dirty(struct extent_io_tree *tree,
+ struct extent_buffer *eb)
+{
+ unsigned long i;
+ unsigned long num_pages;
+
+ num_pages = num_extent_pages(eb->start, eb->len);
+ for (i = 0; i < num_pages; i++) {
+ struct page *page = extent_buffer_page(eb, i);
+ /* writepage may need to do something special for the
+ * first page, we have to make sure page->private is
+ * properly set. releasepage may drop page->private
+ * on us if the page isn't already dirty.
+ */
+ lock_page(page);
+ if (i == 0) {
+ set_page_extent_head(page, eb->len);
+ } else if (PagePrivate(page) &&
+ page->private != EXTENT_PAGE_PRIVATE) {
+ set_page_extent_mapped(page);
+ }
+ __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
+ set_extent_dirty(tree, page_offset(page),
+ page_offset(page) + PAGE_CACHE_SIZE -1,
+ GFP_NOFS);
+ unlock_page(page);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(set_extent_buffer_dirty);
+
+int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb)
+{
+ unsigned long i;
+ struct page *page;
+ unsigned long num_pages;
+
+ num_pages = num_extent_pages(eb->start, eb->len);
+ eb->flags &= ~EXTENT_UPTODATE;
+
+ clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
+ GFP_NOFS);
+ for (i = 0; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ if (page)
+ ClearPageUptodate(page);
+ }
+ return 0;
+}
+
+int set_extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb)
+{
+ unsigned long i;
+ struct page *page;
+ unsigned long num_pages;
+
+ num_pages = num_extent_pages(eb->start, eb->len);
+
+ set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
+ GFP_NOFS);
+ for (i = 0; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
+ ((i == num_pages - 1) &&
+ ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
+ check_page_uptodate(tree, page);
+ continue;
+ }
+ SetPageUptodate(page);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(set_extent_buffer_uptodate);
+
+int extent_range_uptodate(struct extent_io_tree *tree,
+ u64 start, u64 end)
+{
+ struct page *page;
+ int ret;
+ int pg_uptodate = 1;
+ int uptodate;
+ unsigned long index;
+
+ ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1);
+ if (ret)
+ return 1;
+ while(start <= end) {
+ index = start >> PAGE_CACHE_SHIFT;
+ page = find_get_page(tree->mapping, index);
+ uptodate = PageUptodate(page);
+ page_cache_release(page);
+ if (!uptodate) {
+ pg_uptodate = 0;
+ break;
+ }
+ start += PAGE_CACHE_SIZE;
+ }
+ return pg_uptodate;
+}
+
+int extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb)
+{
+ int ret = 0;
+ unsigned long num_pages;
+ unsigned long i;
+ struct page *page;
+ int pg_uptodate = 1;
+
+ if (eb->flags & EXTENT_UPTODATE)
+ return 1;
+
+ ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
+ EXTENT_UPTODATE, 1);
+ if (ret)
+ return ret;
+
+ num_pages = num_extent_pages(eb->start, eb->len);
+ for (i = 0; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ if (!PageUptodate(page)) {
+ pg_uptodate = 0;
+ break;
+ }
+ }
+ return pg_uptodate;
+}
+EXPORT_SYMBOL(extent_buffer_uptodate);
+
+int read_extent_buffer_pages(struct extent_io_tree *tree,
+ struct extent_buffer *eb,
+ u64 start, int wait,
+ get_extent_t *get_extent, int mirror_num)
+{
+ unsigned long i;
+ unsigned long start_i;
+ struct page *page;
+ int err;
+ int ret = 0;
+ int locked_pages = 0;
+ int all_uptodate = 1;
+ int inc_all_pages = 0;
+ unsigned long num_pages;
+ struct bio *bio = NULL;
+ unsigned long bio_flags = 0;
+
+ if (eb->flags & EXTENT_UPTODATE)
+ return 0;
+
+ if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
+ EXTENT_UPTODATE, 1)) {
+ return 0;
+ }
+
+ if (start) {
+ WARN_ON(start < eb->start);
+ start_i = (start >> PAGE_CACHE_SHIFT) -
+ (eb->start >> PAGE_CACHE_SHIFT);
+ } else {
+ start_i = 0;
+ }
+
+ num_pages = num_extent_pages(eb->start, eb->len);
+ for (i = start_i; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ if (!wait) {
+ if (!trylock_page(page))
+ goto unlock_exit;
+ } else {
+ lock_page(page);
+ }
+ locked_pages++;
+ if (!PageUptodate(page)) {
+ all_uptodate = 0;
+ }
+ }
+ if (all_uptodate) {
+ if (start_i == 0)
+ eb->flags |= EXTENT_UPTODATE;
+ if (ret) {
+ printk("all up to date but ret is %d\n", ret);
+ }
+ goto unlock_exit;
+ }
+
+ for (i = start_i; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ if (inc_all_pages)
+ page_cache_get(page);
+ if (!PageUptodate(page)) {
+ if (start_i == 0)
+ inc_all_pages = 1;
+ ClearPageError(page);
+ err = __extent_read_full_page(tree, page,
+ get_extent, &bio,
+ mirror_num, &bio_flags);
+ if (err) {
+ ret = err;
+ printk("err %d from __extent_read_full_page\n", ret);
+ }
+ } else {
+ unlock_page(page);
+ }
+ }
+
+ if (bio)
+ submit_one_bio(READ, bio, mirror_num, bio_flags);
+
+ if (ret || !wait) {
+ if (ret)
+ printk("ret %d wait %d returning\n", ret, wait);
+ return ret;
+ }
+ for (i = start_i; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ wait_on_page_locked(page);
+ if (!PageUptodate(page)) {
+ printk("page not uptodate after wait_on_page_locked\n");
+ ret = -EIO;
+ }
+ }
+ if (!ret)
+ eb->flags |= EXTENT_UPTODATE;
+ return ret;
+
+unlock_exit:
+ i = start_i;
+ while(locked_pages > 0) {
+ page = extent_buffer_page(eb, i);
+ i++;
+ unlock_page(page);
+ locked_pages--;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(read_extent_buffer_pages);
+
+void read_extent_buffer(struct extent_buffer *eb, void *dstv,
+ unsigned long start,
+ unsigned long len)
+{
+ size_t cur;
+ size_t offset;
+ struct page *page;
+ char *kaddr;
+ char *dst = (char *)dstv;
+ size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
+
+ WARN_ON(start > eb->len);
+ WARN_ON(start + len > eb->start + eb->len);
+
+ offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+
+ while(len > 0) {
+ page = extent_buffer_page(eb, i);
+
+ cur = min(len, (PAGE_CACHE_SIZE - offset));
+ kaddr = kmap_atomic(page, KM_USER1);
+ memcpy(dst, kaddr + offset, cur);
+ kunmap_atomic(kaddr, KM_USER1);
+
+ dst += cur;
+ len -= cur;
+ offset = 0;
+ i++;
+ }
+}
+EXPORT_SYMBOL(read_extent_buffer);
+
+int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
+ unsigned long min_len, char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km)
+{
+ size_t offset = start & (PAGE_CACHE_SIZE - 1);
+ char *kaddr;
+ struct page *p;
+ size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
+ unsigned long end_i = (start_offset + start + min_len - 1) >>
+ PAGE_CACHE_SHIFT;
+
+ if (i != end_i)
+ return -EINVAL;
+
+ if (i == 0) {
+ offset = start_offset;
+ *map_start = 0;
+ } else {
+ offset = 0;
+ *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
+ }
+ if (start + min_len > eb->len) {
+printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
+ WARN_ON(1);
+ }
+
+ p = extent_buffer_page(eb, i);
+ kaddr = kmap_atomic(p, km);
+ *token = kaddr;
+ *map = kaddr + offset;
+ *map_len = PAGE_CACHE_SIZE - offset;
+ return 0;
+}
+EXPORT_SYMBOL(map_private_extent_buffer);
+
+int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
+ unsigned long min_len,
+ char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km)
+{
+ int err;
+ int save = 0;
+ if (eb->map_token) {
+ unmap_extent_buffer(eb, eb->map_token, km);
+ eb->map_token = NULL;
+ save = 1;
+ }
+ err = map_private_extent_buffer(eb, start, min_len, token, map,
+ map_start, map_len, km);
+ if (!err && save) {
+ eb->map_token = *token;
+ eb->kaddr = *map;
+ eb->map_start = *map_start;
+ eb->map_len = *map_len;
+ }
+ return err;
+}
+EXPORT_SYMBOL(map_extent_buffer);
+
+void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
+{
+ kunmap_atomic(token, km);
+}
+EXPORT_SYMBOL(unmap_extent_buffer);
+
+int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
+ unsigned long start,
+ unsigned long len)
+{
+ size_t cur;
+ size_t offset;
+ struct page *page;
+ char *kaddr;
+ char *ptr = (char *)ptrv;
+ size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
+ int ret = 0;
+
+ WARN_ON(start > eb->len);
+ WARN_ON(start + len > eb->start + eb->len);
+
+ offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+
+ while(len > 0) {
+ page = extent_buffer_page(eb, i);
+
+ cur = min(len, (PAGE_CACHE_SIZE - offset));
+
+ kaddr = kmap_atomic(page, KM_USER0);
+ ret = memcmp(ptr, kaddr + offset, cur);
+ kunmap_atomic(kaddr, KM_USER0);
+ if (ret)
+ break;
+
+ ptr += cur;
+ len -= cur;
+ offset = 0;
+ i++;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(memcmp_extent_buffer);
+
+void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
+ unsigned long start, unsigned long len)
+{
+ size_t cur;
+ size_t offset;
+ struct page *page;
+ char *kaddr;
+ char *src = (char *)srcv;
+ size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
+
+ WARN_ON(start > eb->len);
+ WARN_ON(start + len > eb->start + eb->len);
+
+ offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+
+ while(len > 0) {
+ page = extent_buffer_page(eb, i);
+ WARN_ON(!PageUptodate(page));
+
+ cur = min(len, PAGE_CACHE_SIZE - offset);
+ kaddr = kmap_atomic(page, KM_USER1);
+ memcpy(kaddr + offset, src, cur);
+ kunmap_atomic(kaddr, KM_USER1);
+
+ src += cur;
+ len -= cur;
+ offset = 0;
+ i++;
+ }
+}
+EXPORT_SYMBOL(write_extent_buffer);
+
+void memset_extent_buffer(struct extent_buffer *eb, char c,
+ unsigned long start, unsigned long len)
+{
+ size_t cur;
+ size_t offset;
+ struct page *page;
+ char *kaddr;
+ size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
+
+ WARN_ON(start > eb->len);
+ WARN_ON(start + len > eb->start + eb->len);
+
+ offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+
+ while(len > 0) {
+ page = extent_buffer_page(eb, i);
+ WARN_ON(!PageUptodate(page));
+
+ cur = min(len, PAGE_CACHE_SIZE - offset);
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + offset, c, cur);
+ kunmap_atomic(kaddr, KM_USER0);
+
+ len -= cur;
+ offset = 0;
+ i++;
+ }
+}
+EXPORT_SYMBOL(memset_extent_buffer);
+
+void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len)
+{
+ u64 dst_len = dst->len;
+ size_t cur;
+ size_t offset;
+ struct page *page;
+ char *kaddr;
+ size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
+
+ WARN_ON(src->len != dst_len);
+
+ offset = (start_offset + dst_offset) &
+ ((unsigned long)PAGE_CACHE_SIZE - 1);
+
+ while(len > 0) {
+ page = extent_buffer_page(dst, i);
+ WARN_ON(!PageUptodate(page));
+
+ cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
+
+ kaddr = kmap_atomic(page, KM_USER0);
+ read_extent_buffer(src, kaddr + offset, src_offset, cur);
+ kunmap_atomic(kaddr, KM_USER0);
+
+ src_offset += cur;
+ len -= cur;
+ offset = 0;
+ i++;
+ }
+}
+EXPORT_SYMBOL(copy_extent_buffer);
+
+static void move_pages(struct page *dst_page, struct page *src_page,
+ unsigned long dst_off, unsigned long src_off,
+ unsigned long len)
+{
+ char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
+ if (dst_page == src_page) {
+ memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
+ } else {
+ char *src_kaddr = kmap_atomic(src_page, KM_USER1);
+ char *p = dst_kaddr + dst_off + len;
+ char *s = src_kaddr + src_off + len;
+
+ while (len--)
+ *--p = *--s;
+
+ kunmap_atomic(src_kaddr, KM_USER1);
+ }
+ kunmap_atomic(dst_kaddr, KM_USER0);
+}
+
+static void copy_pages(struct page *dst_page, struct page *src_page,
+ unsigned long dst_off, unsigned long src_off,
+ unsigned long len)
+{
+ char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
+ char *src_kaddr;
+
+ if (dst_page != src_page)
+ src_kaddr = kmap_atomic(src_page, KM_USER1);
+ else
+ src_kaddr = dst_kaddr;
+
+ memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
+ kunmap_atomic(dst_kaddr, KM_USER0);
+ if (dst_page != src_page)
+ kunmap_atomic(src_kaddr, KM_USER1);
+}
+
+void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len)
+{
+ size_t cur;
+ size_t dst_off_in_page;
+ size_t src_off_in_page;
+ size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long dst_i;
+ unsigned long src_i;
+
+ if (src_offset + len > dst->len) {
+ printk("memmove bogus src_offset %lu move len %lu len %lu\n",
+ src_offset, len, dst->len);
+ BUG_ON(1);
+ }
+ if (dst_offset + len > dst->len) {
+ printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
+ dst_offset, len, dst->len);
+ BUG_ON(1);
+ }
+
+ while(len > 0) {
+ dst_off_in_page = (start_offset + dst_offset) &
+ ((unsigned long)PAGE_CACHE_SIZE - 1);
+ src_off_in_page = (start_offset + src_offset) &
+ ((unsigned long)PAGE_CACHE_SIZE - 1);
+
+ dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
+ src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
+
+ cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
+ src_off_in_page));
+ cur = min_t(unsigned long, cur,
+ (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
+
+ copy_pages(extent_buffer_page(dst, dst_i),
+ extent_buffer_page(dst, src_i),
+ dst_off_in_page, src_off_in_page, cur);
+
+ src_offset += cur;
+ dst_offset += cur;
+ len -= cur;
+ }
+}
+EXPORT_SYMBOL(memcpy_extent_buffer);
+
+void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len)
+{
+ size_t cur;
+ size_t dst_off_in_page;
+ size_t src_off_in_page;
+ unsigned long dst_end = dst_offset + len - 1;
+ unsigned long src_end = src_offset + len - 1;
+ size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
+ unsigned long dst_i;
+ unsigned long src_i;
+
+ if (src_offset + len > dst->len) {
+ printk("memmove bogus src_offset %lu move len %lu len %lu\n",
+ src_offset, len, dst->len);
+ BUG_ON(1);
+ }
+ if (dst_offset + len > dst->len) {
+ printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
+ dst_offset, len, dst->len);
+ BUG_ON(1);
+ }
+ if (dst_offset < src_offset) {
+ memcpy_extent_buffer(dst, dst_offset, src_offset, len);
+ return;
+ }
+ while(len > 0) {
+ dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
+ src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
+
+ dst_off_in_page = (start_offset + dst_end) &
+ ((unsigned long)PAGE_CACHE_SIZE - 1);
+ src_off_in_page = (start_offset + src_end) &
+ ((unsigned long)PAGE_CACHE_SIZE - 1);
+
+ cur = min_t(unsigned long, len, src_off_in_page + 1);
+ cur = min(cur, dst_off_in_page + 1);
+ move_pages(extent_buffer_page(dst, dst_i),
+ extent_buffer_page(dst, src_i),
+ dst_off_in_page - cur + 1,
+ src_off_in_page - cur + 1, cur);
+
+ dst_end -= cur;
+ src_end -= cur;
+ len -= cur;
+ }
+}
+EXPORT_SYMBOL(memmove_extent_buffer);
+
+int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
+{
+ u64 start = page_offset(page);
+ struct extent_buffer *eb;
+ int ret = 1;
+ unsigned long i;
+ unsigned long num_pages;
+
+ spin_lock(&tree->buffer_lock);
+ eb = buffer_search(tree, start);
+ if (!eb)
+ goto out;
+
+ if (atomic_read(&eb->refs) > 1) {
+ ret = 0;
+ goto out;
+ }
+ /* at this point we can safely release the extent buffer */
+ num_pages = num_extent_pages(eb->start, eb->len);
+ for (i = 0; i < num_pages; i++)
+ page_cache_release(extent_buffer_page(eb, i));
+ rb_erase(&eb->rb_node, &tree->buffer);
+ __free_extent_buffer(eb);
+out:
+ spin_unlock(&tree->buffer_lock);
+ return ret;
+}
+EXPORT_SYMBOL(try_release_extent_buffer);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
new file mode 100644
index 0000000..2d5f670
--- /dev/null
+++ b/fs/btrfs/extent_io.h
@@ -0,0 +1,268 @@
+#ifndef __EXTENTIO__
+#define __EXTENTIO__
+
+#include <linux/rbtree.h>
+
+/* bits for the extent state */
+#define EXTENT_DIRTY 1
+#define EXTENT_WRITEBACK (1 << 1)
+#define EXTENT_UPTODATE (1 << 2)
+#define EXTENT_LOCKED (1 << 3)
+#define EXTENT_NEW (1 << 4)
+#define EXTENT_DELALLOC (1 << 5)
+#define EXTENT_DEFRAG (1 << 6)
+#define EXTENT_DEFRAG_DONE (1 << 7)
+#define EXTENT_BUFFER_FILLED (1 << 8)
+#define EXTENT_ORDERED (1 << 9)
+#define EXTENT_ORDERED_METADATA (1 << 10)
+#define EXTENT_BOUNDARY (1 << 11)
+#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
+
+/* flags for bio submission */
+#define EXTENT_BIO_COMPRESSED 1
+
+/*
+ * page->private values. Every page that is controlled by the extent
+ * map has page->private set to one.
+ */
+#define EXTENT_PAGE_PRIVATE 1
+#define EXTENT_PAGE_PRIVATE_FIRST_PAGE 3
+
+struct extent_state;
+
+typedef int (extent_submit_bio_hook_t)(struct inode *inode, int rw,
+ struct bio *bio, int mirror_num,
+ unsigned long bio_flags);
+struct extent_io_ops {
+ int (*fill_delalloc)(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written);
+ int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
+ int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
+ extent_submit_bio_hook_t *submit_bio_hook;
+ int (*merge_bio_hook)(struct page *page, unsigned long offset,
+ size_t size, struct bio *bio,
+ unsigned long bio_flags);
+ int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
+ int (*readpage_io_failed_hook)(struct bio *bio, struct page *page,
+ u64 start, u64 end,
+ struct extent_state *state);
+ int (*writepage_io_failed_hook)(struct bio *bio, struct page *page,
+ u64 start, u64 end,
+ struct extent_state *state);
+ int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end,
+ struct extent_state *state);
+ int (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
+ struct extent_state *state, int uptodate);
+ int (*set_bit_hook)(struct inode *inode, u64 start, u64 end,
+ unsigned long old, unsigned long bits);
+ int (*clear_bit_hook)(struct inode *inode, u64 start, u64 end,
+ unsigned long old, unsigned long bits);
+ int (*write_cache_pages_lock_hook)(struct page *page);
+};
+
+struct extent_io_tree {
+ struct rb_root state;
+ struct rb_root buffer;
+ struct address_space *mapping;
+ u64 dirty_bytes;
+ spinlock_t lock;
+ spinlock_t buffer_lock;
+ struct extent_io_ops *ops;
+};
+
+struct extent_state {
+ u64 start;
+ u64 end; /* inclusive */
+ struct rb_node rb_node;
+ struct extent_io_tree *tree;
+ wait_queue_head_t wq;
+ atomic_t refs;
+ unsigned long state;
+
+ /* for use by the FS */
+ u64 private;
+
+ struct list_head leak_list;
+};
+
+struct extent_buffer {
+ u64 start;
+ unsigned long len;
+ char *map_token;
+ char *kaddr;
+ unsigned long map_start;
+ unsigned long map_len;
+ struct page *first_page;
+ atomic_t refs;
+ int flags;
+ struct list_head leak_list;
+ struct rb_node rb_node;
+ struct mutex mutex;
+};
+
+struct extent_map_tree;
+
+static inline struct extent_state *extent_state_next(struct extent_state *state)
+{
+ struct rb_node *node;
+ node = rb_next(&state->rb_node);
+ if (!node)
+ return NULL;
+ return rb_entry(node, struct extent_state, rb_node);
+}
+
+typedef struct extent_map *(get_extent_t)(struct inode *inode,
+ struct page *page,
+ size_t page_offset,
+ u64 start, u64 len,
+ int create);
+
+void extent_io_tree_init(struct extent_io_tree *tree,
+ struct address_space *mapping, gfp_t mask);
+int try_release_extent_mapping(struct extent_map_tree *map,
+ struct extent_io_tree *tree, struct page *page,
+ gfp_t mask);
+int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page);
+int try_release_extent_state(struct extent_map_tree *map,
+ struct extent_io_tree *tree, struct page *page,
+ gfp_t mask);
+int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask);
+int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask);
+int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
+ get_extent_t *get_extent);
+int __init extent_io_init(void);
+void extent_io_exit(void);
+
+u64 count_range_bits(struct extent_io_tree *tree,
+ u64 *start, u64 search_end,
+ u64 max_bytes, unsigned long bits);
+
+int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, int filled);
+int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, gfp_t mask);
+int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, int wake, int delete, gfp_t mask);
+int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, gfp_t mask);
+int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int clear_extent_ordered_metadata(struct extent_io_tree *tree, u64 start,
+ u64 end, gfp_t mask);
+int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
+ u64 *start_ret, u64 *end_ret, int bits);
+struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
+ u64 start, int bits);
+int extent_invalidatepage(struct extent_io_tree *tree,
+ struct page *page, unsigned long offset);
+int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
+ get_extent_t *get_extent,
+ struct writeback_control *wbc);
+int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
+ u64 start, u64 end, get_extent_t *get_extent,
+ int mode);
+int extent_writepages(struct extent_io_tree *tree,
+ struct address_space *mapping,
+ get_extent_t *get_extent,
+ struct writeback_control *wbc);
+int extent_readpages(struct extent_io_tree *tree,
+ struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages,
+ get_extent_t get_extent);
+int extent_prepare_write(struct extent_io_tree *tree,
+ struct inode *inode, struct page *page,
+ unsigned from, unsigned to, get_extent_t *get_extent);
+int extent_commit_write(struct extent_io_tree *tree,
+ struct inode *inode, struct page *page,
+ unsigned from, unsigned to);
+sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
+ get_extent_t *get_extent);
+int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end);
+int set_state_private(struct extent_io_tree *tree, u64 start, u64 private);
+int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private);
+void set_page_extent_mapped(struct page *page);
+
+struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
+ u64 start, unsigned long len,
+ struct page *page0,
+ gfp_t mask);
+struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
+ u64 start, unsigned long len,
+ gfp_t mask);
+void free_extent_buffer(struct extent_buffer *eb);
+int read_extent_buffer_pages(struct extent_io_tree *tree,
+ struct extent_buffer *eb, u64 start, int wait,
+ get_extent_t *get_extent, int mirror_num);
+
+static inline void extent_buffer_get(struct extent_buffer *eb)
+{
+ atomic_inc(&eb->refs);
+}
+
+int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
+ unsigned long start,
+ unsigned long len);
+void read_extent_buffer(struct extent_buffer *eb, void *dst,
+ unsigned long start,
+ unsigned long len);
+void write_extent_buffer(struct extent_buffer *eb, const void *src,
+ unsigned long start, unsigned long len);
+void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len);
+void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len);
+void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len);
+void memset_extent_buffer(struct extent_buffer *eb, char c,
+ unsigned long start, unsigned long len);
+int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end);
+int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits);
+int clear_extent_buffer_dirty(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int set_extent_buffer_dirty(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int set_extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int map_extent_buffer(struct extent_buffer *eb, unsigned long offset,
+ unsigned long min_len, char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km);
+int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,
+ unsigned long min_len, char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km);
+void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km);
+int release_extent_buffer_tail_pages(struct extent_buffer *eb);
+int extent_range_uptodate(struct extent_io_tree *tree,
+ u64 start, u64 end);
+int extent_clear_unlock_delalloc(struct inode *inode,
+ struct extent_io_tree *tree,
+ u64 start, u64 end, struct page *locked_page,
+ int unlock_page,
+ int clear_unlock,
+ int clear_delalloc, int clear_dirty,
+ int set_writeback,
+ int end_writeback);
+#endif
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
new file mode 100644
index 0000000..fd3ebfb
--- /dev/null
+++ b/fs/btrfs/extent_map.c
@@ -0,0 +1,351 @@
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/version.h>
+#include <linux/hardirq.h>
+#include "extent_map.h"
+
+/* temporary define until extent_map moves out of btrfs */
+struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
+ unsigned long extra_flags,
+ void (*ctor)(void *, struct kmem_cache *,
+ unsigned long));
+
+static struct kmem_cache *extent_map_cache;
+
+int __init extent_map_init(void)
+{
+ extent_map_cache = btrfs_cache_create("extent_map",
+ sizeof(struct extent_map), 0,
+ NULL);
+ if (!extent_map_cache)
+ return -ENOMEM;
+ return 0;
+}
+
+void extent_map_exit(void)
+{
+ if (extent_map_cache)
+ kmem_cache_destroy(extent_map_cache);
+}
+
+/**
+ * extent_map_tree_init - initialize extent map tree
+ * @tree: tree to initialize
+ * @mask: flags for memory allocations during tree operations
+ *
+ * Initialize the extent tree @tree. Should be called for each new inode
+ * or other user of the extent_map interface.
+ */
+void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask)
+{
+ tree->map.rb_node = NULL;
+ spin_lock_init(&tree->lock);
+}
+EXPORT_SYMBOL(extent_map_tree_init);
+
+/**
+ * alloc_extent_map - allocate new extent map structure
+ * @mask: memory allocation flags
+ *
+ * Allocate a new extent_map structure. The new structure is
+ * returned with a reference count of one and needs to be
+ * freed using free_extent_map()
+ */
+struct extent_map *alloc_extent_map(gfp_t mask)
+{
+ struct extent_map *em;
+ em = kmem_cache_alloc(extent_map_cache, mask);
+ if (!em || IS_ERR(em))
+ return em;
+ em->in_tree = 0;
+ em->flags = 0;
+ atomic_set(&em->refs, 1);
+ return em;
+}
+EXPORT_SYMBOL(alloc_extent_map);
+
+/**
+ * free_extent_map - drop reference count of an extent_map
+ * @em: extent map beeing releasead
+ *
+ * Drops the reference out on @em by one and free the structure
+ * if the reference count hits zero.
+ */
+void free_extent_map(struct extent_map *em)
+{
+ if (!em)
+ return;
+ WARN_ON(atomic_read(&em->refs) == 0);
+ if (atomic_dec_and_test(&em->refs)) {
+ WARN_ON(em->in_tree);
+ kmem_cache_free(extent_map_cache, em);
+ }
+}
+EXPORT_SYMBOL(free_extent_map);
+
+static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
+ struct rb_node *node)
+{
+ struct rb_node ** p = &root->rb_node;
+ struct rb_node * parent = NULL;
+ struct extent_map *entry;
+
+ while(*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct extent_map, rb_node);
+
+ WARN_ON(!entry->in_tree);
+
+ if (offset < entry->start)
+ p = &(*p)->rb_left;
+ else if (offset >= extent_map_end(entry))
+ p = &(*p)->rb_right;
+ else
+ return parent;
+ }
+
+ entry = rb_entry(node, struct extent_map, rb_node);
+ entry->in_tree = 1;
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+ return NULL;
+}
+
+/*
+ * search through the tree for an extent_map with a given offset. If
+ * it can't be found, try to find some neighboring extents
+ */
+static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
+ struct rb_node **prev_ret,
+ struct rb_node **next_ret)
+{
+ struct rb_node * n = root->rb_node;
+ struct rb_node *prev = NULL;
+ struct rb_node *orig_prev = NULL;
+ struct extent_map *entry;
+ struct extent_map *prev_entry = NULL;
+
+ while(n) {
+ entry = rb_entry(n, struct extent_map, rb_node);
+ prev = n;
+ prev_entry = entry;
+
+ WARN_ON(!entry->in_tree);
+
+ if (offset < entry->start)
+ n = n->rb_left;
+ else if (offset >= extent_map_end(entry))
+ n = n->rb_right;
+ else
+ return n;
+ }
+
+ if (prev_ret) {
+ orig_prev = prev;
+ while(prev && offset >= extent_map_end(prev_entry)) {
+ prev = rb_next(prev);
+ prev_entry = rb_entry(prev, struct extent_map, rb_node);
+ }
+ *prev_ret = prev;
+ prev = orig_prev;
+ }
+
+ if (next_ret) {
+ prev_entry = rb_entry(prev, struct extent_map, rb_node);
+ while(prev && offset < prev_entry->start) {
+ prev = rb_prev(prev);
+ prev_entry = rb_entry(prev, struct extent_map, rb_node);
+ }
+ *next_ret = prev;
+ }
+ return NULL;
+}
+
+/*
+ * look for an offset in the tree, and if it can't be found, return
+ * the first offset we can find smaller than 'offset'.
+ */
+static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
+{
+ struct rb_node *prev;
+ struct rb_node *ret;
+ ret = __tree_search(root, offset, &prev, NULL);
+ if (!ret)
+ return prev;
+ return ret;
+}
+
+/* check to see if two extent_map structs are adjacent and safe to merge */
+static int mergable_maps(struct extent_map *prev, struct extent_map *next)
+{
+ if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
+ return 0;
+
+ /*
+ * don't merge compressed extents, we need to know their
+ * actual size
+ */
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &prev->flags))
+ return 0;
+
+ if (extent_map_end(prev) == next->start &&
+ prev->flags == next->flags &&
+ prev->bdev == next->bdev &&
+ ((next->block_start == EXTENT_MAP_HOLE &&
+ prev->block_start == EXTENT_MAP_HOLE) ||
+ (next->block_start == EXTENT_MAP_INLINE &&
+ prev->block_start == EXTENT_MAP_INLINE) ||
+ (next->block_start == EXTENT_MAP_DELALLOC &&
+ prev->block_start == EXTENT_MAP_DELALLOC) ||
+ (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
+ next->block_start == extent_map_block_end(prev)))) {
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * add_extent_mapping - add new extent map to the extent tree
+ * @tree: tree to insert new map in
+ * @em: map to insert
+ *
+ * Insert @em into @tree or perform a simple forward/backward merge with
+ * existing mappings. The extent_map struct passed in will be inserted
+ * into the tree directly, with an additional reference taken, or a
+ * reference dropped if the merge attempt was sucessfull.
+ */
+int add_extent_mapping(struct extent_map_tree *tree,
+ struct extent_map *em)
+{
+ int ret = 0;
+ struct extent_map *merge = NULL;
+ struct rb_node *rb;
+ struct extent_map *exist;
+
+ exist = lookup_extent_mapping(tree, em->start, em->len);
+ if (exist) {
+ free_extent_map(exist);
+ ret = -EEXIST;
+ goto out;
+ }
+ assert_spin_locked(&tree->lock);
+ rb = tree_insert(&tree->map, em->start, &em->rb_node);
+ if (rb) {
+ ret = -EEXIST;
+ free_extent_map(merge);
+ goto out;
+ }
+ atomic_inc(&em->refs);
+ if (em->start != 0) {
+ rb = rb_prev(&em->rb_node);
+ if (rb)
+ merge = rb_entry(rb, struct extent_map, rb_node);
+ if (rb && mergable_maps(merge, em)) {
+ em->start = merge->start;
+ em->len += merge->len;
+ em->block_len += merge->block_len;
+ em->block_start = merge->block_start;
+ merge->in_tree = 0;
+ rb_erase(&merge->rb_node, &tree->map);
+ free_extent_map(merge);
+ }
+ }
+ rb = rb_next(&em->rb_node);
+ if (rb)
+ merge = rb_entry(rb, struct extent_map, rb_node);
+ if (rb && mergable_maps(em, merge)) {
+ em->len += merge->len;
+ em->block_len += merge->len;
+ rb_erase(&merge->rb_node, &tree->map);
+ merge->in_tree = 0;
+ free_extent_map(merge);
+ }
+out:
+ return ret;
+}
+EXPORT_SYMBOL(add_extent_mapping);
+
+/* simple helper to do math around the end of an extent, handling wrap */
+static u64 range_end(u64 start, u64 len)
+{
+ if (start + len < start)
+ return (u64)-1;
+ return start + len;
+}
+
+/**
+ * lookup_extent_mapping - lookup extent_map
+ * @tree: tree to lookup in
+ * @start: byte offset to start the search
+ * @len: length of the lookup range
+ *
+ * Find and return the first extent_map struct in @tree that intersects the
+ * [start, len] range. There may be additional objects in the tree that
+ * intersect, so check the object returned carefully to make sure that no
+ * additional lookups are needed.
+ */
+struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
+ u64 start, u64 len)
+{
+ struct extent_map *em;
+ struct rb_node *rb_node;
+ struct rb_node *prev = NULL;
+ struct rb_node *next = NULL;
+ u64 end = range_end(start, len);
+
+ assert_spin_locked(&tree->lock);
+ rb_node = __tree_search(&tree->map, start, &prev, &next);
+ if (!rb_node && prev) {
+ em = rb_entry(prev, struct extent_map, rb_node);
+ if (end > em->start && start < extent_map_end(em))
+ goto found;
+ }
+ if (!rb_node && next) {
+ em = rb_entry(next, struct extent_map, rb_node);
+ if (end > em->start && start < extent_map_end(em))
+ goto found;
+ }
+ if (!rb_node) {
+ em = NULL;
+ goto out;
+ }
+ if (IS_ERR(rb_node)) {
+ em = ERR_PTR(PTR_ERR(rb_node));
+ goto out;
+ }
+ em = rb_entry(rb_node, struct extent_map, rb_node);
+ if (end > em->start && start < extent_map_end(em))
+ goto found;
+
+ em = NULL;
+ goto out;
+
+found:
+ atomic_inc(&em->refs);
+out:
+ return em;
+}
+EXPORT_SYMBOL(lookup_extent_mapping);
+
+/**
+ * remove_extent_mapping - removes an extent_map from the extent tree
+ * @tree: extent tree to remove from
+ * @em: extent map beeing removed
+ *
+ * Removes @em from @tree. No reference counts are dropped, and no checks
+ * are done to see if the range is in use
+ */
+int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
+{
+ int ret = 0;
+
+ WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
+ assert_spin_locked(&tree->lock);
+ rb_erase(&em->rb_node, &tree->map);
+ em->in_tree = 0;
+ return ret;
+}
+EXPORT_SYMBOL(remove_extent_mapping);
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
new file mode 100644
index 0000000..fb6eeef
--- /dev/null
+++ b/fs/btrfs/extent_map.h
@@ -0,0 +1,62 @@
+#ifndef __EXTENTMAP__
+#define __EXTENTMAP__
+
+#include <linux/rbtree.h>
+
+#define EXTENT_MAP_LAST_BYTE (u64)-4
+#define EXTENT_MAP_HOLE (u64)-3
+#define EXTENT_MAP_INLINE (u64)-2
+#define EXTENT_MAP_DELALLOC (u64)-1
+
+/* bits for the flags field */
+#define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
+#define EXTENT_FLAG_COMPRESSED 1
+#define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
+#define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
+
+struct extent_map {
+ struct rb_node rb_node;
+
+ /* all of these are in bytes */
+ u64 start;
+ u64 len;
+ u64 orig_start;
+ u64 block_start;
+ u64 block_len;
+ unsigned long flags;
+ struct block_device *bdev;
+ atomic_t refs;
+ int in_tree;
+};
+
+struct extent_map_tree {
+ struct rb_root map;
+ spinlock_t lock;
+};
+
+static inline u64 extent_map_end(struct extent_map *em)
+{
+ if (em->start + em->len < em->start)
+ return (u64)-1;
+ return em->start + em->len;
+}
+
+static inline u64 extent_map_block_end(struct extent_map *em)
+{
+ if (em->block_start + em->block_len < em->block_start)
+ return (u64)-1;
+ return em->block_start + em->block_len;
+}
+
+void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
+struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
+ u64 start, u64 len);
+int add_extent_mapping(struct extent_map_tree *tree,
+ struct extent_map *em);
+int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
+
+struct extent_map *alloc_extent_map(gfp_t mask);
+void free_extent_map(struct extent_map *em);
+int __init extent_map_init(void);
+void extent_map_exit(void);
+#endif
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
new file mode 100644
index 0000000..f763788
--- /dev/null
+++ b/fs/btrfs/file-item.c
@@ -0,0 +1,586 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+
+#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+ sizeof(struct btrfs_item) * 2) / \
+ BTRFS_CRC32_SIZE) - 1))
+int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 pos,
+ u64 disk_offset, u64 disk_num_bytes,
+ u64 num_bytes, u64 offset, u64 ram_bytes,
+ u8 compression, u8 encryption, u16 other_encoding)
+{
+ int ret = 0;
+ struct btrfs_file_extent_item *item;
+ struct btrfs_key file_key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ file_key.objectid = objectid;
+ file_key.offset = pos;
+ btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
+
+ ret = btrfs_insert_empty_item(trans, root, path, &file_key,
+ sizeof(*item));
+ if (ret < 0)
+ goto out;
+ BUG_ON(ret);
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
+ btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
+ btrfs_set_file_extent_offset(leaf, item, offset);
+ btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
+ btrfs_set_file_extent_generation(leaf, item, trans->transid);
+ btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
+ btrfs_set_file_extent_compression(leaf, item, compression);
+ btrfs_set_file_extent_encryption(leaf, item, encryption);
+ btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
+
+ btrfs_mark_buffer_dirty(leaf);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid, u64 offset,
+ int cow)
+{
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ struct btrfs_csum_item *item;
+ struct extent_buffer *leaf;
+ u64 csum_offset = 0;
+ int csums_in_item;
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
+ if (ret < 0)
+ goto fail;
+ leaf = path->nodes[0];
+ if (ret > 0) {
+ ret = 1;
+ if (path->slots[0] == 0)
+ goto fail;
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid) {
+ goto fail;
+ }
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
+ csums_in_item /= BTRFS_CRC32_SIZE;
+
+ if (csum_offset >= csums_in_item) {
+ ret = -EFBIG;
+ goto fail;
+ }
+ }
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * BTRFS_CRC32_SIZE);
+ return item;
+fail:
+ if (ret > 0)
+ ret = -ENOENT;
+ return ERR_PTR(ret);
+}
+
+
+int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid,
+ u64 offset, int mod)
+{
+ int ret;
+ struct btrfs_key file_key;
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
+ ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
+ return ret;
+}
+
+int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
+ struct bio *bio)
+{
+ u32 sum;
+ struct bio_vec *bvec = bio->bi_io_vec;
+ int bio_index = 0;
+ u64 offset;
+ u64 item_start_offset = 0;
+ u64 item_last_offset = 0;
+ u32 diff;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_csum_item *item = NULL;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+
+ path = btrfs_alloc_path();
+ if (bio->bi_size > PAGE_CACHE_SIZE * 8)
+ path->reada = 2;
+
+ WARN_ON(bio->bi_vcnt <= 0);
+
+ while(bio_index < bio->bi_vcnt) {
+ offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+ ret = btrfs_find_ordered_sum(inode, offset, &sum);
+ if (ret == 0)
+ goto found;
+
+ if (!item || offset < item_start_offset ||
+ offset >= item_last_offset) {
+ struct btrfs_key found_key;
+ u32 item_size;
+
+ if (item)
+ btrfs_release_path(root, path);
+ item = btrfs_lookup_csum(NULL, root, path,
+ inode->i_ino, offset, 0);
+ if (IS_ERR(item)) {
+ ret = PTR_ERR(item);
+ if (ret == -ENOENT || ret == -EFBIG)
+ ret = 0;
+ sum = 0;
+ printk("no csum found for inode %lu start "
+ "%llu\n", inode->i_ino,
+ (unsigned long long)offset);
+ item = NULL;
+ btrfs_release_path(root, path);
+ goto found;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+
+ item_start_offset = found_key.offset;
+ item_size = btrfs_item_size_nr(path->nodes[0],
+ path->slots[0]);
+ item_last_offset = item_start_offset +
+ (item_size / BTRFS_CRC32_SIZE) *
+ root->sectorsize;
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_csum_item);
+ }
+ /*
+ * this byte range must be able to fit inside
+ * a single leaf so it will also fit inside a u32
+ */
+ diff = offset - item_start_offset;
+ diff = diff / root->sectorsize;
+ diff = diff * BTRFS_CRC32_SIZE;
+
+ read_extent_buffer(path->nodes[0], &sum,
+ ((unsigned long)item) + diff,
+ BTRFS_CRC32_SIZE);
+found:
+ set_state_private(io_tree, offset, sum);
+ bio_index++;
+ bvec++;
+ }
+ btrfs_free_path(path);
+ return 0;
+}
+
+int btrfs_csum_file_bytes(struct btrfs_root *root, struct inode *inode,
+ u64 start, unsigned long len)
+{
+ struct btrfs_ordered_sum *sums;
+ struct btrfs_sector_sum *sector_sum;
+ struct btrfs_ordered_extent *ordered;
+ char *data;
+ struct page *page;
+ unsigned long total_bytes = 0;
+ unsigned long this_sum_bytes = 0;
+
+ sums = kzalloc(btrfs_ordered_sum_size(root, len), GFP_NOFS);
+ if (!sums)
+ return -ENOMEM;
+
+ sector_sum = sums->sums;
+ sums->file_offset = start;
+ sums->len = len;
+ INIT_LIST_HEAD(&sums->list);
+ ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
+ BUG_ON(!ordered);
+
+ while(len > 0) {
+ if (start >= ordered->file_offset + ordered->len ||
+ start < ordered->file_offset) {
+ sums->len = this_sum_bytes;
+ this_sum_bytes = 0;
+ btrfs_add_ordered_sum(inode, ordered, sums);
+ btrfs_put_ordered_extent(ordered);
+
+ sums = kzalloc(btrfs_ordered_sum_size(root, len),
+ GFP_NOFS);
+ BUG_ON(!sums);
+ sector_sum = sums->sums;
+ sums->len = len;
+ sums->file_offset = start;
+ ordered = btrfs_lookup_ordered_extent(inode,
+ sums->file_offset);
+ BUG_ON(!ordered);
+ }
+
+ page = find_get_page(inode->i_mapping,
+ start >> PAGE_CACHE_SHIFT);
+
+ data = kmap_atomic(page, KM_USER0);
+ sector_sum->sum = ~(u32)0;
+ sector_sum->sum = btrfs_csum_data(root, data, sector_sum->sum,
+ PAGE_CACHE_SIZE);
+ kunmap_atomic(data, KM_USER0);
+ btrfs_csum_final(sector_sum->sum,
+ (char *)§or_sum->sum);
+ sector_sum->offset = page_offset(page);
+ page_cache_release(page);
+
+ sector_sum++;
+ total_bytes += PAGE_CACHE_SIZE;
+ this_sum_bytes += PAGE_CACHE_SIZE;
+ start += PAGE_CACHE_SIZE;
+
+ WARN_ON(len < PAGE_CACHE_SIZE);
+ len -= PAGE_CACHE_SIZE;
+ }
+ btrfs_add_ordered_sum(inode, ordered, sums);
+ btrfs_put_ordered_extent(ordered);
+ return 0;
+}
+
+int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
+ struct bio *bio)
+{
+ struct btrfs_ordered_sum *sums;
+ struct btrfs_sector_sum *sector_sum;
+ struct btrfs_ordered_extent *ordered;
+ char *data;
+ struct bio_vec *bvec = bio->bi_io_vec;
+ int bio_index = 0;
+ unsigned long total_bytes = 0;
+ unsigned long this_sum_bytes = 0;
+ u64 offset;
+
+ WARN_ON(bio->bi_vcnt <= 0);
+ sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
+ if (!sums)
+ return -ENOMEM;
+
+ sector_sum = sums->sums;
+ sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+ sums->len = bio->bi_size;
+ INIT_LIST_HEAD(&sums->list);
+ ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
+ BUG_ON(!ordered);
+
+ while(bio_index < bio->bi_vcnt) {
+ offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+ if (offset >= ordered->file_offset + ordered->len ||
+ offset < ordered->file_offset) {
+ unsigned long bytes_left;
+ sums->len = this_sum_bytes;
+ this_sum_bytes = 0;
+ btrfs_add_ordered_sum(inode, ordered, sums);
+ btrfs_put_ordered_extent(ordered);
+
+ bytes_left = bio->bi_size - total_bytes;
+
+ sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
+ GFP_NOFS);
+ BUG_ON(!sums);
+ sector_sum = sums->sums;
+ sums->len = bytes_left;
+ sums->file_offset = offset;
+ ordered = btrfs_lookup_ordered_extent(inode,
+ sums->file_offset);
+ BUG_ON(!ordered);
+ }
+
+ data = kmap_atomic(bvec->bv_page, KM_USER0);
+ sector_sum->sum = ~(u32)0;
+ sector_sum->sum = btrfs_csum_data(root,
+ data + bvec->bv_offset,
+ sector_sum->sum,
+ bvec->bv_len);
+ kunmap_atomic(data, KM_USER0);
+ btrfs_csum_final(sector_sum->sum,
+ (char *)§or_sum->sum);
+ sector_sum->offset = page_offset(bvec->bv_page) +
+ bvec->bv_offset;
+
+ sector_sum++;
+ bio_index++;
+ total_bytes += bvec->bv_len;
+ this_sum_bytes += bvec->bv_len;
+ bvec++;
+ }
+ this_sum_bytes = 0;
+ btrfs_add_ordered_sum(inode, ordered, sums);
+ btrfs_put_ordered_extent(ordered);
+ return 0;
+}
+
+int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ struct btrfs_ordered_sum *sums)
+{
+ u64 objectid = inode->i_ino;
+ u64 offset;
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ u64 next_offset;
+ u64 total_bytes = 0;
+ int found_next;
+ struct btrfs_path *path;
+ struct btrfs_csum_item *item;
+ struct btrfs_csum_item *item_end;
+ struct extent_buffer *leaf = NULL;
+ u64 csum_offset;
+ struct btrfs_sector_sum *sector_sum;
+ u32 nritems;
+ u32 ins_size;
+ char *eb_map;
+ char *eb_token;
+ unsigned long map_len;
+ unsigned long map_start;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ sector_sum = sums->sums;
+again:
+ next_offset = (u64)-1;
+ found_next = 0;
+ offset = sector_sum->offset;
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+
+ mutex_lock(&BTRFS_I(inode)->csum_mutex);
+ item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
+ if (!IS_ERR(item)) {
+ leaf = path->nodes[0];
+ ret = 0;
+ goto found;
+ }
+ ret = PTR_ERR(item);
+ if (ret == -EFBIG) {
+ u32 item_size;
+ /* we found one, but it isn't big enough yet */
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
+ /* already at max size, make a new one */
+ goto insert;
+ }
+ } else {
+ int slot = path->slots[0] + 1;
+ /* we didn't find a csum item, insert one */
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (path->slots[0] >= nritems - 1) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 1)
+ found_next = 1;
+ if (ret != 0)
+ goto insert;
+ slot = 0;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
+ if (found_key.objectid != objectid ||
+ found_key.type != BTRFS_CSUM_ITEM_KEY) {
+ found_next = 1;
+ goto insert;
+ }
+ next_offset = found_key.offset;
+ found_next = 1;
+ goto insert;
+ }
+
+ /*
+ * at this point, we know the tree has an item, but it isn't big
+ * enough yet to put our csum in. Grow it
+ */
+ btrfs_release_path(root, path);
+ ret = btrfs_search_slot(trans, root, &file_key, path,
+ BTRFS_CRC32_SIZE, 1);
+ if (ret < 0)
+ goto fail_unlock;
+ if (ret == 0) {
+ BUG();
+ }
+ if (path->slots[0] == 0) {
+ goto insert;
+ }
+ path->slots[0]--;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid ||
+ csum_offset >= MAX_CSUM_ITEMS(root)) {
+ goto insert;
+ }
+ if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
+ BTRFS_CRC32_SIZE) {
+ u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
+ diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
+ if (diff != BTRFS_CRC32_SIZE)
+ goto insert;
+ ret = btrfs_extend_item(trans, root, path, diff);
+ BUG_ON(ret);
+ goto csum;
+ }
+
+insert:
+ btrfs_release_path(root, path);
+ csum_offset = 0;
+ if (found_next) {
+ u64 tmp = min((u64)i_size_read(inode), next_offset);
+ tmp -= offset & ~((u64)root->sectorsize -1);
+ tmp >>= root->fs_info->sb->s_blocksize_bits;
+ tmp = max((u64)1, tmp);
+ tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
+ ins_size = BTRFS_CRC32_SIZE * tmp;
+ } else {
+ ins_size = BTRFS_CRC32_SIZE;
+ }
+ ret = btrfs_insert_empty_item(trans, root, path, &file_key,
+ ins_size);
+ if (ret < 0)
+ goto fail_unlock;
+ if (ret != 0) {
+ WARN_ON(1);
+ goto fail_unlock;
+ }
+csum:
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ ret = 0;
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * BTRFS_CRC32_SIZE);
+found:
+ item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
+ btrfs_item_size_nr(leaf, path->slots[0]));
+ eb_token = NULL;
+ mutex_unlock(&BTRFS_I(inode)->csum_mutex);
+ cond_resched();
+next_sector:
+
+ if (!eb_token ||
+ (unsigned long)item + BTRFS_CRC32_SIZE >= map_start + map_len) {
+ int err;
+
+ if (eb_token)
+ unmap_extent_buffer(leaf, eb_token, KM_USER1);
+ eb_token = NULL;
+ err = map_private_extent_buffer(leaf, (unsigned long)item,
+ BTRFS_CRC32_SIZE,
+ &eb_token, &eb_map,
+ &map_start, &map_len, KM_USER1);
+ if (err)
+ eb_token = NULL;
+ }
+ if (eb_token) {
+ memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
+ §or_sum->sum, BTRFS_CRC32_SIZE);
+ } else {
+ write_extent_buffer(leaf, §or_sum->sum,
+ (unsigned long)item, BTRFS_CRC32_SIZE);
+ }
+
+ total_bytes += root->sectorsize;
+ sector_sum++;
+ if (total_bytes < sums->len) {
+ item = (struct btrfs_csum_item *)((char *)item +
+ BTRFS_CRC32_SIZE);
+ if (item < item_end && offset + PAGE_CACHE_SIZE ==
+ sector_sum->offset) {
+ offset = sector_sum->offset;
+ goto next_sector;
+ }
+ }
+ if (eb_token) {
+ unmap_extent_buffer(leaf, eb_token, KM_USER1);
+ eb_token = NULL;
+ }
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ cond_resched();
+ if (total_bytes < sums->len) {
+ btrfs_release_path(root, path);
+ goto again;
+ }
+out:
+ btrfs_free_path(path);
+ return ret;
+
+fail_unlock:
+ mutex_unlock(&BTRFS_I(inode)->csum_mutex);
+ goto out;
+}
+
+int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ u64 isize)
+{
+ struct btrfs_key key;
+ struct extent_buffer *leaf = path->nodes[0];
+ int slot = path->slots[0];
+ int ret;
+ u32 new_item_size;
+ u64 new_item_span;
+ u64 blocks;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (isize <= key.offset)
+ return 0;
+ new_item_span = isize - key.offset;
+ blocks = (new_item_span + root->sectorsize - 1) >>
+ root->fs_info->sb->s_blocksize_bits;
+ new_item_size = blocks * BTRFS_CRC32_SIZE;
+ if (new_item_size >= btrfs_item_size_nr(leaf, slot))
+ return 0;
+ ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
+ BUG_ON(ret);
+ return ret;
+}
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
new file mode 100644
index 0000000..1e8c024
--- /dev/null
+++ b/fs/btrfs/file.c
@@ -0,0 +1,1299 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/version.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+#include "tree-log.h"
+#include "locking.h"
+#include "compat.h"
+
+
+/* simple helper to fault in pages and copy. This should go away
+ * and be replaced with calls into generic code.
+ */
+static int noinline btrfs_copy_from_user(loff_t pos, int num_pages,
+ int write_bytes,
+ struct page **prepared_pages,
+ const char __user * buf)
+{
+ long page_fault = 0;
+ int i;
+ int offset = pos & (PAGE_CACHE_SIZE - 1);
+
+ for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
+ size_t count = min_t(size_t,
+ PAGE_CACHE_SIZE - offset, write_bytes);
+ struct page *page = prepared_pages[i];
+ fault_in_pages_readable(buf, count);
+
+ /* Copy data from userspace to the current page */
+ kmap(page);
+ page_fault = __copy_from_user(page_address(page) + offset,
+ buf, count);
+ /* Flush processor's dcache for this page */
+ flush_dcache_page(page);
+ kunmap(page);
+ buf += count;
+ write_bytes -= count;
+
+ if (page_fault)
+ break;
+ }
+ return page_fault ? -EFAULT : 0;
+}
+
+/*
+ * unlocks pages after btrfs_file_write is done with them
+ */
+static void noinline btrfs_drop_pages(struct page **pages, size_t num_pages)
+{
+ size_t i;
+ for (i = 0; i < num_pages; i++) {
+ if (!pages[i])
+ break;
+ /* page checked is some magic around finding pages that
+ * have been modified without going through btrfs_set_page_dirty
+ * clear it here
+ */
+ ClearPageChecked(pages[i]);
+ unlock_page(pages[i]);
+ mark_page_accessed(pages[i]);
+ page_cache_release(pages[i]);
+ }
+}
+
+/*
+ * after copy_from_user, pages need to be dirtied and we need to make
+ * sure holes are created between the current EOF and the start of
+ * any next extents (if required).
+ *
+ * this also makes the decision about creating an inline extent vs
+ * doing real data extents, marking pages dirty and delalloc as required.
+ */
+static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct file *file,
+ struct page **pages,
+ size_t num_pages,
+ loff_t pos,
+ size_t write_bytes)
+{
+ int err = 0;
+ int i;
+ struct inode *inode = fdentry(file)->d_inode;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ u64 hint_byte;
+ u64 num_bytes;
+ u64 start_pos;
+ u64 end_of_last_block;
+ u64 end_pos = pos + write_bytes;
+ loff_t isize = i_size_read(inode);
+
+ start_pos = pos & ~((u64)root->sectorsize - 1);
+ num_bytes = (write_bytes + pos - start_pos +
+ root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
+
+ end_of_last_block = start_pos + num_bytes - 1;
+
+ lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
+ trans = btrfs_join_transaction(root, 1);
+ if (!trans) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+ btrfs_set_trans_block_group(trans, inode);
+ hint_byte = 0;
+
+ if ((end_of_last_block & 4095) == 0) {
+ printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block);
+ }
+ set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS);
+
+ /* check for reserved extents on each page, we don't want
+ * to reset the delalloc bit on things that already have
+ * extents reserved.
+ */
+ btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block);
+ for (i = 0; i < num_pages; i++) {
+ struct page *p = pages[i];
+ SetPageUptodate(p);
+ ClearPageChecked(p);
+ set_page_dirty(p);
+ }
+ if (end_pos > isize) {
+ i_size_write(inode, end_pos);
+ btrfs_update_inode(trans, root, inode);
+ }
+ err = btrfs_end_transaction(trans, root);
+out_unlock:
+ unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
+ return err;
+}
+
+/*
+ * this drops all the extents in the cache that intersect the range
+ * [start, end]. Existing extents are split as required.
+ */
+int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
+ int skip_pinned)
+{
+ struct extent_map *em;
+ struct extent_map *split = NULL;
+ struct extent_map *split2 = NULL;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ u64 len = end - start + 1;
+ int ret;
+ int testend = 1;
+ unsigned long flags;
+ int compressed = 0;
+
+ WARN_ON(end < start);
+ if (end == (u64)-1) {
+ len = (u64)-1;
+ testend = 0;
+ }
+ while(1) {
+ if (!split)
+ split = alloc_extent_map(GFP_NOFS);
+ if (!split2)
+ split2 = alloc_extent_map(GFP_NOFS);
+
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (!em) {
+ spin_unlock(&em_tree->lock);
+ break;
+ }
+ flags = em->flags;
+ if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
+ spin_unlock(&em_tree->lock);
+ if (em->start <= start &&
+ (!testend || em->start + em->len >= start + len)) {
+ free_extent_map(em);
+ break;
+ }
+ if (start < em->start) {
+ len = em->start - start;
+ } else {
+ len = start + len - (em->start + em->len);
+ start = em->start + em->len;
+ }
+ free_extent_map(em);
+ continue;
+ }
+ compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ clear_bit(EXTENT_FLAG_PINNED, &em->flags);
+ remove_extent_mapping(em_tree, em);
+
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ em->start < start) {
+ split->start = em->start;
+ split->len = start - em->start;
+ split->orig_start = em->orig_start;
+ split->block_start = em->block_start;
+
+ if (compressed)
+ split->block_len = em->block_len;
+ else
+ split->block_len = split->len;
+
+ split->bdev = em->bdev;
+ split->flags = flags;
+ ret = add_extent_mapping(em_tree, split);
+ BUG_ON(ret);
+ free_extent_map(split);
+ split = split2;
+ split2 = NULL;
+ }
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ testend && em->start + em->len > start + len) {
+ u64 diff = start + len - em->start;
+
+ split->start = start + len;
+ split->len = em->start + em->len - (start + len);
+ split->bdev = em->bdev;
+ split->flags = flags;
+
+ if (compressed) {
+ split->block_len = em->block_len;
+ split->block_start = em->block_start;
+ split->orig_start = em->orig_start;
+ } else {
+ split->block_len = split->len;
+ split->block_start = em->block_start + diff;
+ split->orig_start = split->start;
+ }
+
+ ret = add_extent_mapping(em_tree, split);
+ BUG_ON(ret);
+ free_extent_map(split);
+ split = NULL;
+ }
+ spin_unlock(&em_tree->lock);
+
+ /* once for us */
+ free_extent_map(em);
+ /* once for the tree*/
+ free_extent_map(em);
+ }
+ if (split)
+ free_extent_map(split);
+ if (split2)
+ free_extent_map(split2);
+ return 0;
+}
+
+int btrfs_check_file(struct btrfs_root *root, struct inode *inode)
+{
+ return 0;
+#if 0
+ struct btrfs_path *path;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *extent;
+ u64 last_offset = 0;
+ int nritems;
+ int slot;
+ int found_type;
+ int ret;
+ int err = 0;
+ u64 extent_end = 0;
+
+ path = btrfs_alloc_path();
+ ret = btrfs_lookup_file_extent(NULL, root, path, inode->i_ino,
+ last_offset, 0);
+ while(1) {
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ goto out;
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ }
+ slot = path->slots[0];
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.objectid != inode->i_ino)
+ break;
+ if (found_key.type != BTRFS_EXTENT_DATA_KEY)
+ goto out;
+
+ if (found_key.offset < last_offset) {
+ WARN_ON(1);
+ btrfs_print_leaf(root, leaf);
+ printk("inode %lu found offset %Lu expected %Lu\n",
+ inode->i_ino, found_key.offset, last_offset);
+ err = 1;
+ goto out;
+ }
+ extent = btrfs_item_ptr(leaf, slot,
+ struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(leaf, extent);
+ if (found_type == BTRFS_FILE_EXTENT_REG) {
+ extent_end = found_key.offset +
+ btrfs_file_extent_num_bytes(leaf, extent);
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ struct btrfs_item *item;
+ item = btrfs_item_nr(leaf, slot);
+ extent_end = found_key.offset +
+ btrfs_file_extent_inline_len(leaf, extent);
+ extent_end = (extent_end + root->sectorsize - 1) &
+ ~((u64)root->sectorsize -1 );
+ }
+ last_offset = extent_end;
+ path->slots[0]++;
+ }
+ if (0 && last_offset < inode->i_size) {
+ WARN_ON(1);
+ btrfs_print_leaf(root, leaf);
+ printk("inode %lu found offset %Lu size %Lu\n", inode->i_ino,
+ last_offset, inode->i_size);
+ err = 1;
+
+ }
+out:
+ btrfs_free_path(path);
+ return err;
+#endif
+}
+
+/*
+ * this is very complex, but the basic idea is to drop all extents
+ * in the range start - end. hint_block is filled in with a block number
+ * that would be a good hint to the block allocator for this file.
+ *
+ * If an extent intersects the range but is not entirely inside the range
+ * it is either truncated or split. Anything entirely inside the range
+ * is deleted from the tree.
+ *
+ * inline_limit is used to tell this code which offsets in the file to keep
+ * if they contain inline extents.
+ */
+int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ u64 start, u64 end, u64 inline_limit, u64 *hint_byte)
+{
+ u64 extent_end = 0;
+ u64 locked_end = end;
+ u64 search_start = start;
+ u64 leaf_start;
+ u64 ram_bytes = 0;
+ u64 orig_parent = 0;
+ u64 disk_bytenr = 0;
+ u8 compression;
+ u8 encryption;
+ u16 other_encoding = 0;
+ u64 root_gen;
+ u64 root_owner;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *extent;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_file_extent_item old;
+ int keep;
+ int slot;
+ int bookend;
+ int found_type = 0;
+ int found_extent;
+ int found_inline;
+ int recow;
+ int ret;
+
+ inline_limit = 0;
+ btrfs_drop_extent_cache(inode, start, end - 1, 0);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ while(1) {
+ recow = 0;
+ btrfs_release_path(root, path);
+ ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
+ search_start, -1);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ if (path->slots[0] == 0) {
+ ret = 0;
+ goto out;
+ }
+ path->slots[0]--;
+ }
+next_slot:
+ keep = 0;
+ bookend = 0;
+ found_extent = 0;
+ found_inline = 0;
+ leaf_start = 0;
+ root_gen = 0;
+ root_owner = 0;
+ compression = 0;
+ encryption = 0;
+ extent = NULL;
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ ret = 0;
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY &&
+ key.offset >= end) {
+ goto out;
+ }
+ if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
+ key.objectid != inode->i_ino) {
+ goto out;
+ }
+ if (recow) {
+ search_start = max(key.offset, start);
+ continue;
+ }
+ if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
+ extent = btrfs_item_ptr(leaf, slot,
+ struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(leaf, extent);
+ compression = btrfs_file_extent_compression(leaf,
+ extent);
+ encryption = btrfs_file_extent_encryption(leaf,
+ extent);
+ other_encoding = btrfs_file_extent_other_encoding(leaf,
+ extent);
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ extent_end =
+ btrfs_file_extent_disk_bytenr(leaf,
+ extent);
+ if (extent_end)
+ *hint_byte = extent_end;
+
+ extent_end = key.offset +
+ btrfs_file_extent_num_bytes(leaf, extent);
+ ram_bytes = btrfs_file_extent_ram_bytes(leaf,
+ extent);
+ found_extent = 1;
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ found_inline = 1;
+ extent_end = key.offset +
+ btrfs_file_extent_inline_len(leaf, extent);
+ }
+ } else {
+ extent_end = search_start;
+ }
+
+ /* we found nothing we can drop */
+ if ((!found_extent && !found_inline) ||
+ search_start >= extent_end) {
+ int nextret;
+ u32 nritems;
+ nritems = btrfs_header_nritems(leaf);
+ if (slot >= nritems - 1) {
+ nextret = btrfs_next_leaf(root, path);
+ if (nextret)
+ goto out;
+ recow = 1;
+ } else {
+ path->slots[0]++;
+ }
+ goto next_slot;
+ }
+
+ if (end <= extent_end && start >= key.offset && found_inline)
+ *hint_byte = EXTENT_MAP_INLINE;
+
+ if (found_extent) {
+ read_extent_buffer(leaf, &old, (unsigned long)extent,
+ sizeof(old));
+ root_gen = btrfs_header_generation(leaf);
+ root_owner = btrfs_header_owner(leaf);
+ leaf_start = leaf->start;
+ }
+
+ if (end < extent_end && end >= key.offset) {
+ bookend = 1;
+ if (found_inline && start <= key.offset)
+ keep = 1;
+ }
+
+ if (bookend && found_extent) {
+ if (locked_end < extent_end) {
+ ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
+ locked_end, extent_end - 1,
+ GFP_NOFS);
+ if (!ret) {
+ btrfs_release_path(root, path);
+ lock_extent(&BTRFS_I(inode)->io_tree,
+ locked_end, extent_end - 1,
+ GFP_NOFS);
+ locked_end = extent_end;
+ continue;
+ }
+ locked_end = extent_end;
+ }
+ orig_parent = path->nodes[0]->start;
+ disk_bytenr = le64_to_cpu(old.disk_bytenr);
+ if (disk_bytenr != 0) {
+ ret = btrfs_inc_extent_ref(trans, root,
+ disk_bytenr,
+ le64_to_cpu(old.disk_num_bytes),
+ orig_parent, root->root_key.objectid,
+ trans->transid, inode->i_ino);
+ BUG_ON(ret);
+ }
+ }
+
+ if (found_inline) {
+ u64 mask = root->sectorsize - 1;
+ search_start = (extent_end + mask) & ~mask;
+ } else
+ search_start = extent_end;
+
+ /* truncate existing extent */
+ if (start > key.offset) {
+ u64 new_num;
+ u64 old_num;
+ keep = 1;
+ WARN_ON(start & (root->sectorsize - 1));
+ if (found_extent) {
+ new_num = start - key.offset;
+ old_num = btrfs_file_extent_num_bytes(leaf,
+ extent);
+ *hint_byte =
+ btrfs_file_extent_disk_bytenr(leaf,
+ extent);
+ if (btrfs_file_extent_disk_bytenr(leaf,
+ extent)) {
+ inode_sub_bytes(inode, old_num -
+ new_num);
+ }
+ if (!compression && !encryption) {
+ btrfs_set_file_extent_ram_bytes(leaf,
+ extent, new_num);
+ }
+ btrfs_set_file_extent_num_bytes(leaf,
+ extent, new_num);
+ btrfs_mark_buffer_dirty(leaf);
+ } else if (key.offset < inline_limit &&
+ (end > extent_end) &&
+ (inline_limit < extent_end)) {
+ u32 new_size;
+ new_size = btrfs_file_extent_calc_inline_size(
+ inline_limit - key.offset);
+ inode_sub_bytes(inode, extent_end -
+ inline_limit);
+ btrfs_set_file_extent_ram_bytes(leaf, extent,
+ new_size);
+ if (!compression && !encryption) {
+ btrfs_truncate_item(trans, root, path,
+ new_size, 1);
+ }
+ }
+ }
+ /* delete the entire extent */
+ if (!keep) {
+ if (found_inline)
+ inode_sub_bytes(inode, extent_end -
+ key.offset);
+ ret = btrfs_del_item(trans, root, path);
+ /* TODO update progress marker and return */
+ BUG_ON(ret);
+ extent = NULL;
+ btrfs_release_path(root, path);
+ /* the extent will be freed later */
+ }
+ if (bookend && found_inline && start <= key.offset) {
+ u32 new_size;
+ new_size = btrfs_file_extent_calc_inline_size(
+ extent_end - end);
+ inode_sub_bytes(inode, end - key.offset);
+ btrfs_set_file_extent_ram_bytes(leaf, extent,
+ new_size);
+ if (!compression && !encryption)
+ ret = btrfs_truncate_item(trans, root, path,
+ new_size, 0);
+ BUG_ON(ret);
+ }
+ /* create bookend, splitting the extent in two */
+ if (bookend && found_extent) {
+ struct btrfs_key ins;
+ ins.objectid = inode->i_ino;
+ ins.offset = end;
+ btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
+
+ btrfs_release_path(root, path);
+ ret = btrfs_insert_empty_item(trans, root, path, &ins,
+ sizeof(*extent));
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ write_extent_buffer(leaf, &old,
+ (unsigned long)extent, sizeof(old));
+
+ btrfs_set_file_extent_compression(leaf, extent,
+ compression);
+ btrfs_set_file_extent_encryption(leaf, extent,
+ encryption);
+ btrfs_set_file_extent_other_encoding(leaf, extent,
+ other_encoding);
+ btrfs_set_file_extent_offset(leaf, extent,
+ le64_to_cpu(old.offset) + end - key.offset);
+ WARN_ON(le64_to_cpu(old.num_bytes) <
+ (extent_end - end));
+ btrfs_set_file_extent_num_bytes(leaf, extent,
+ extent_end - end);
+
+ /*
+ * set the ram bytes to the size of the full extent
+ * before splitting. This is a worst case flag,
+ * but its the best we can do because we don't know
+ * how splitting affects compression
+ */
+ btrfs_set_file_extent_ram_bytes(leaf, extent,
+ ram_bytes);
+ btrfs_set_file_extent_type(leaf, extent, found_type);
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
+ if (disk_bytenr != 0) {
+ ret = btrfs_update_extent_ref(trans, root,
+ disk_bytenr, orig_parent,
+ leaf->start,
+ root->root_key.objectid,
+ trans->transid, ins.objectid);
+
+ BUG_ON(ret);
+ }
+ btrfs_release_path(root, path);
+ if (disk_bytenr != 0) {
+ inode_add_bytes(inode, extent_end - end);
+ }
+ }
+
+ if (found_extent && !keep) {
+ u64 disk_bytenr = le64_to_cpu(old.disk_bytenr);
+
+ if (disk_bytenr != 0) {
+ inode_sub_bytes(inode,
+ le64_to_cpu(old.num_bytes));
+ ret = btrfs_free_extent(trans, root,
+ disk_bytenr,
+ le64_to_cpu(old.disk_num_bytes),
+ leaf_start, root_owner,
+ root_gen, key.objectid, 0);
+ BUG_ON(ret);
+ *hint_byte = disk_bytenr;
+ }
+ }
+
+ if (search_start >= end) {
+ ret = 0;
+ goto out;
+ }
+ }
+out:
+ btrfs_free_path(path);
+ if (locked_end > end) {
+ unlock_extent(&BTRFS_I(inode)->io_tree, end, locked_end - 1,
+ GFP_NOFS);
+ }
+ btrfs_check_file(root, inode);
+ return ret;
+}
+
+static int extent_mergeable(struct extent_buffer *leaf, int slot,
+ u64 objectid, u64 bytenr, u64 *start, u64 *end)
+{
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ u64 extent_end;
+
+ if (slot < 0 || slot >= btrfs_header_nritems(leaf))
+ return 0;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
+ return 0;
+
+ fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
+ btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
+ btrfs_file_extent_compression(leaf, fi) ||
+ btrfs_file_extent_encryption(leaf, fi) ||
+ btrfs_file_extent_other_encoding(leaf, fi))
+ return 0;
+
+ extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+ if ((*start && *start != key.offset) || (*end && *end != extent_end))
+ return 0;
+
+ *start = key.offset;
+ *end = extent_end;
+ return 1;
+}
+
+/*
+ * Mark extent in the range start - end as written.
+ *
+ * This changes extent type from 'pre-allocated' to 'regular'. If only
+ * part of extent is marked as written, the extent will be split into
+ * two or three.
+ */
+int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode, u64 start, u64 end)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_path *path;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ u64 bytenr;
+ u64 num_bytes;
+ u64 extent_end;
+ u64 extent_offset;
+ u64 other_start;
+ u64 other_end;
+ u64 split = start;
+ u64 locked_end = end;
+ u64 orig_parent;
+ int extent_type;
+ int split_end = 1;
+ int ret;
+
+ btrfs_drop_extent_cache(inode, start, end - 1, 0);
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+again:
+ key.objectid = inode->i_ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ if (split == start)
+ key.offset = split;
+ else
+ key.offset = split - 1;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0 && path->slots[0] > 0)
+ path->slots[0]--;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ BUG_ON(key.objectid != inode->i_ino ||
+ key.type != BTRFS_EXTENT_DATA_KEY);
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+ BUG_ON(extent_type != BTRFS_FILE_EXTENT_PREALLOC);
+ extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+ BUG_ON(key.offset > start || extent_end < end);
+
+ bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ extent_offset = btrfs_file_extent_offset(leaf, fi);
+
+ if (key.offset == start)
+ split = end;
+
+ if (key.offset == start && extent_end == end) {
+ int del_nr = 0;
+ int del_slot = 0;
+ u64 leaf_owner = btrfs_header_owner(leaf);
+ u64 leaf_gen = btrfs_header_generation(leaf);
+ other_start = end;
+ other_end = 0;
+ if (extent_mergeable(leaf, path->slots[0] + 1, inode->i_ino,
+ bytenr, &other_start, &other_end)) {
+ extent_end = other_end;
+ del_slot = path->slots[0] + 1;
+ del_nr++;
+ ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
+ leaf->start, leaf_owner,
+ leaf_gen, inode->i_ino, 0);
+ BUG_ON(ret);
+ }
+ other_start = 0;
+ other_end = start;
+ if (extent_mergeable(leaf, path->slots[0] - 1, inode->i_ino,
+ bytenr, &other_start, &other_end)) {
+ key.offset = other_start;
+ del_slot = path->slots[0];
+ del_nr++;
+ ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
+ leaf->start, leaf_owner,
+ leaf_gen, inode->i_ino, 0);
+ BUG_ON(ret);
+ }
+ split_end = 0;
+ if (del_nr == 0) {
+ btrfs_set_file_extent_type(leaf, fi,
+ BTRFS_FILE_EXTENT_REG);
+ goto done;
+ }
+
+ fi = btrfs_item_ptr(leaf, del_slot - 1,
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_end - key.offset);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
+ BUG_ON(ret);
+ goto done;
+ } else if (split == start) {
+ if (locked_end < extent_end) {
+ ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
+ locked_end, extent_end - 1, GFP_NOFS);
+ if (!ret) {
+ btrfs_release_path(root, path);
+ lock_extent(&BTRFS_I(inode)->io_tree,
+ locked_end, extent_end - 1, GFP_NOFS);
+ locked_end = extent_end;
+ goto again;
+ }
+ locked_end = extent_end;
+ }
+ btrfs_set_file_extent_num_bytes(leaf, fi, split - key.offset);
+ extent_offset += split - key.offset;
+ } else {
+ BUG_ON(key.offset != start);
+ btrfs_set_file_extent_offset(leaf, fi, extent_offset +
+ split - key.offset);
+ btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - split);
+ key.offset = split;
+ btrfs_set_item_key_safe(trans, root, path, &key);
+ extent_end = split;
+ }
+
+ if (extent_end == end) {
+ split_end = 0;
+ extent_type = BTRFS_FILE_EXTENT_REG;
+ }
+ if (extent_end == end && split == start) {
+ other_start = end;
+ other_end = 0;
+ if (extent_mergeable(leaf, path->slots[0] + 1, inode->i_ino,
+ bytenr, &other_start, &other_end)) {
+ path->slots[0]++;
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ key.offset = split;
+ btrfs_set_item_key_safe(trans, root, path, &key);
+ btrfs_set_file_extent_offset(leaf, fi, extent_offset);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ other_end - split);
+ goto done;
+ }
+ }
+ if (extent_end == end && split == end) {
+ other_start = 0;
+ other_end = start;
+ if (extent_mergeable(leaf, path->slots[0] - 1 , inode->i_ino,
+ bytenr, &other_start, &other_end)) {
+ path->slots[0]--;
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_num_bytes(leaf, fi, extent_end -
+ other_start);
+ goto done;
+ }
+ }
+
+ btrfs_mark_buffer_dirty(leaf);
+
+ orig_parent = leaf->start;
+ ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
+ orig_parent, root->root_key.objectid,
+ trans->transid, inode->i_ino);
+ BUG_ON(ret);
+ btrfs_release_path(root, path);
+
+ key.offset = start;
+ ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*fi));
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+ btrfs_set_file_extent_type(leaf, fi, extent_type);
+ btrfs_set_file_extent_disk_bytenr(leaf, fi, bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
+ btrfs_set_file_extent_offset(leaf, fi, extent_offset);
+ btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - key.offset);
+ btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
+ btrfs_set_file_extent_compression(leaf, fi, 0);
+ btrfs_set_file_extent_encryption(leaf, fi, 0);
+ btrfs_set_file_extent_other_encoding(leaf, fi, 0);
+
+ if (orig_parent != leaf->start) {
+ ret = btrfs_update_extent_ref(trans, root, bytenr,
+ orig_parent, leaf->start,
+ root->root_key.objectid,
+ trans->transid, inode->i_ino);
+ BUG_ON(ret);
+ }
+done:
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(root, path);
+ if (split_end && split == start) {
+ split = end;
+ goto again;
+ }
+ if (locked_end > end) {
+ unlock_extent(&BTRFS_I(inode)->io_tree, end, locked_end - 1,
+ GFP_NOFS);
+ }
+ btrfs_free_path(path);
+ return 0;
+}
+
+/*
+ * this gets pages into the page cache and locks them down, it also properly
+ * waits for data=ordered extents to finish before allowing the pages to be
+ * modified.
+ */
+static int noinline prepare_pages(struct btrfs_root *root, struct file *file,
+ struct page **pages, size_t num_pages,
+ loff_t pos, unsigned long first_index,
+ unsigned long last_index, size_t write_bytes)
+{
+ int i;
+ unsigned long index = pos >> PAGE_CACHE_SHIFT;
+ struct inode *inode = fdentry(file)->d_inode;
+ int err = 0;
+ u64 start_pos;
+ u64 last_pos;
+
+ start_pos = pos & ~((u64)root->sectorsize - 1);
+ last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
+
+ if (start_pos > inode->i_size) {
+ err = btrfs_cont_expand(inode, start_pos);
+ if (err)
+ return err;
+ }
+
+ memset(pages, 0, num_pages * sizeof(struct page *));
+again:
+ for (i = 0; i < num_pages; i++) {
+ pages[i] = grab_cache_page(inode->i_mapping, index + i);
+ if (!pages[i]) {
+ err = -ENOMEM;
+ BUG_ON(1);
+ }
+ wait_on_page_writeback(pages[i]);
+ }
+ if (start_pos < inode->i_size) {
+ struct btrfs_ordered_extent *ordered;
+ lock_extent(&BTRFS_I(inode)->io_tree,
+ start_pos, last_pos - 1, GFP_NOFS);
+ ordered = btrfs_lookup_first_ordered_extent(inode, last_pos -1);
+ if (ordered &&
+ ordered->file_offset + ordered->len > start_pos &&
+ ordered->file_offset < last_pos) {
+ btrfs_put_ordered_extent(ordered);
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ start_pos, last_pos - 1, GFP_NOFS);
+ for (i = 0; i < num_pages; i++) {
+ unlock_page(pages[i]);
+ page_cache_release(pages[i]);
+ }
+ btrfs_wait_ordered_range(inode, start_pos,
+ last_pos - start_pos);
+ goto again;
+ }
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+
+ clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos,
+ last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC,
+ GFP_NOFS);
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ start_pos, last_pos - 1, GFP_NOFS);
+ }
+ for (i = 0; i < num_pages; i++) {
+ clear_page_dirty_for_io(pages[i]);
+ set_page_extent_mapped(pages[i]);
+ WARN_ON(!PageLocked(pages[i]));
+ }
+ return 0;
+}
+
+static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ loff_t pos;
+ loff_t start_pos;
+ ssize_t num_written = 0;
+ ssize_t err = 0;
+ int ret = 0;
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct page **pages = NULL;
+ int nrptrs;
+ struct page *pinned[2];
+ unsigned long first_index;
+ unsigned long last_index;
+ int will_write;
+
+ will_write = ((file->f_flags & O_SYNC) || IS_SYNC(inode) ||
+ (file->f_flags & O_DIRECT));
+
+ nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
+ PAGE_CACHE_SIZE / (sizeof(struct page *)));
+ pinned[0] = NULL;
+ pinned[1] = NULL;
+
+ pos = *ppos;
+ start_pos = pos;
+
+ vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+ current->backing_dev_info = inode->i_mapping->backing_dev_info;
+ err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
+ if (err)
+ goto out_nolock;
+ if (count == 0)
+ goto out_nolock;
+
+ err = file_remove_suid(file);
+ if (err)
+ goto out_nolock;
+ file_update_time(file);
+
+ pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
+
+ mutex_lock(&inode->i_mutex);
+ first_index = pos >> PAGE_CACHE_SHIFT;
+ last_index = (pos + count) >> PAGE_CACHE_SHIFT;
+
+ /*
+ * if this is a nodatasum mount, force summing off for the inode
+ * all the time. That way a later mount with summing on won't
+ * get confused
+ */
+ if (btrfs_test_opt(root, NODATASUM))
+ btrfs_set_flag(inode, NODATASUM);
+
+ /*
+ * there are lots of better ways to do this, but this code
+ * makes sure the first and last page in the file range are
+ * up to date and ready for cow
+ */
+ if ((pos & (PAGE_CACHE_SIZE - 1))) {
+ pinned[0] = grab_cache_page(inode->i_mapping, first_index);
+ if (!PageUptodate(pinned[0])) {
+ ret = btrfs_readpage(NULL, pinned[0]);
+ BUG_ON(ret);
+ wait_on_page_locked(pinned[0]);
+ } else {
+ unlock_page(pinned[0]);
+ }
+ }
+ if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
+ pinned[1] = grab_cache_page(inode->i_mapping, last_index);
+ if (!PageUptodate(pinned[1])) {
+ ret = btrfs_readpage(NULL, pinned[1]);
+ BUG_ON(ret);
+ wait_on_page_locked(pinned[1]);
+ } else {
+ unlock_page(pinned[1]);
+ }
+ }
+
+ while(count > 0) {
+ size_t offset = pos & (PAGE_CACHE_SIZE - 1);
+ size_t write_bytes = min(count, nrptrs *
+ (size_t)PAGE_CACHE_SIZE -
+ offset);
+ size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
+ PAGE_CACHE_SHIFT;
+
+ WARN_ON(num_pages > nrptrs);
+ memset(pages, 0, sizeof(pages));
+
+ ret = btrfs_check_free_space(root, write_bytes, 0);
+ if (ret)
+ goto out;
+
+ ret = prepare_pages(root, file, pages, num_pages,
+ pos, first_index, last_index,
+ write_bytes);
+ if (ret)
+ goto out;
+
+ ret = btrfs_copy_from_user(pos, num_pages,
+ write_bytes, pages, buf);
+ if (ret) {
+ btrfs_drop_pages(pages, num_pages);
+ goto out;
+ }
+
+ ret = dirty_and_release_pages(NULL, root, file, pages,
+ num_pages, pos, write_bytes);
+ btrfs_drop_pages(pages, num_pages);
+ if (ret)
+ goto out;
+
+ if (will_write) {
+ btrfs_fdatawrite_range(inode->i_mapping, pos,
+ pos + write_bytes - 1,
+ WB_SYNC_NONE);
+ } else {
+ balance_dirty_pages_ratelimited_nr(inode->i_mapping,
+ num_pages);
+ if (num_pages <
+ (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
+ btrfs_btree_balance_dirty(root, 1);
+ btrfs_throttle(root);
+ }
+
+ buf += write_bytes;
+ count -= write_bytes;
+ pos += write_bytes;
+ num_written += write_bytes;
+
+ cond_resched();
+ }
+out:
+ mutex_unlock(&inode->i_mutex);
+
+out_nolock:
+ kfree(pages);
+ if (pinned[0])
+ page_cache_release(pinned[0]);
+ if (pinned[1])
+ page_cache_release(pinned[1]);
+ *ppos = pos;
+
+ if (num_written > 0 && will_write) {
+ struct btrfs_trans_handle *trans;
+
+ err = btrfs_wait_ordered_range(inode, start_pos, num_written);
+ if (err)
+ num_written = err;
+
+ if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) {
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_log_dentry_safe(trans, root,
+ file->f_dentry);
+ if (ret == 0) {
+ btrfs_sync_log(trans, root);
+ btrfs_end_transaction(trans, root);
+ } else {
+ btrfs_commit_transaction(trans, root);
+ }
+ }
+ if (file->f_flags & O_DIRECT) {
+ invalidate_mapping_pages(inode->i_mapping,
+ start_pos >> PAGE_CACHE_SHIFT,
+ (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
+ }
+ }
+ current->backing_dev_info = NULL;
+ return num_written ? num_written : err;
+}
+
+int btrfs_release_file(struct inode * inode, struct file * filp)
+{
+ if (filp->private_data)
+ btrfs_ioctl_trans_end(filp);
+ return 0;
+}
+
+/*
+ * fsync call for both files and directories. This logs the inode into
+ * the tree log instead of forcing full commits whenever possible.
+ *
+ * It needs to call filemap_fdatawait so that all ordered extent updates are
+ * in the metadata btree are up to date for copying to the log.
+ *
+ * It drops the inode mutex before doing the tree log commit. This is an
+ * important optimization for directories because holding the mutex prevents
+ * new operations on the dir while we write to disk.
+ */
+int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
+{
+ struct inode *inode = dentry->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+ struct btrfs_trans_handle *trans;
+
+ /*
+ * check the transaction that last modified this inode
+ * and see if its already been committed
+ */
+ if (!BTRFS_I(inode)->last_trans)
+ goto out;
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (BTRFS_I(inode)->last_trans <=
+ root->fs_info->last_trans_committed) {
+ BTRFS_I(inode)->last_trans = 0;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ goto out;
+ }
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ root->fs_info->tree_log_batch++;
+ filemap_fdatawait(inode->i_mapping);
+ root->fs_info->tree_log_batch++;
+
+ /*
+ * ok we haven't committed the transaction yet, lets do a commit
+ */
+ if (file->private_data)
+ btrfs_ioctl_trans_end(file);
+
+ trans = btrfs_start_transaction(root, 1);
+ if (!trans) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = btrfs_log_dentry_safe(trans, root, file->f_dentry);
+ if (ret < 0) {
+ goto out;
+ }
+
+ /* we've logged all the items and now have a consistent
+ * version of the file in the log. It is possible that
+ * someone will come in and modify the file, but that's
+ * fine because the log is consistent on disk, and we
+ * have references to all of the file's extents
+ *
+ * It is possible that someone will come in and log the
+ * file again, but that will end up using the synchronization
+ * inside btrfs_sync_log to keep things safe.
+ */
+ mutex_unlock(&file->f_dentry->d_inode->i_mutex);
+
+ if (ret > 0) {
+ ret = btrfs_commit_transaction(trans, root);
+ } else {
+ btrfs_sync_log(trans, root);
+ ret = btrfs_end_transaction(trans, root);
+ }
+ mutex_lock(&file->f_dentry->d_inode->i_mutex);
+out:
+ return ret > 0 ? EIO : ret;
+}
+
+static struct vm_operations_struct btrfs_file_vm_ops = {
+ .fault = filemap_fault,
+ .page_mkwrite = btrfs_page_mkwrite,
+};
+
+static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ vma->vm_ops = &btrfs_file_vm_ops;
+ file_accessed(filp);
+ return 0;
+}
+
+struct file_operations btrfs_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = do_sync_read,
+ .aio_read = generic_file_aio_read,
+ .splice_read = generic_file_splice_read,
+ .write = btrfs_file_write,
+ .mmap = btrfs_file_mmap,
+ .open = generic_file_open,
+ .release = btrfs_release_file,
+ .fsync = btrfs_sync_file,
+ .unlocked_ioctl = btrfs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = btrfs_ioctl,
+#endif
+};
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
new file mode 100644
index 0000000..f4926c0
--- /dev/null
+++ b/fs/btrfs/free-space-cache.c
@@ -0,0 +1,489 @@
+/*
+ * Copyright (C) 2008 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include "ctree.h"
+
+static int tree_insert_offset(struct rb_root *root, u64 offset,
+ struct rb_node *node)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct btrfs_free_space *info;
+
+ while (*p) {
+ parent = *p;
+ info = rb_entry(parent, struct btrfs_free_space, offset_index);
+
+ if (offset < info->offset)
+ p = &(*p)->rb_left;
+ else if (offset > info->offset)
+ p = &(*p)->rb_right;
+ else
+ return -EEXIST;
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+
+ return 0;
+}
+
+static int tree_insert_bytes(struct rb_root *root, u64 bytes,
+ struct rb_node *node)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct btrfs_free_space *info;
+
+ while (*p) {
+ parent = *p;
+ info = rb_entry(parent, struct btrfs_free_space, bytes_index);
+
+ if (bytes < info->bytes)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+
+ return 0;
+}
+
+/*
+ * searches the tree for the given offset. If contains is set we will return
+ * the free space that contains the given offset. If contains is not set we
+ * will return the free space that starts at or after the given offset and is
+ * at least bytes long.
+ */
+static struct btrfs_free_space *tree_search_offset(struct rb_root *root,
+ u64 offset, u64 bytes,
+ int contains)
+{
+ struct rb_node *n = root->rb_node;
+ struct btrfs_free_space *entry, *ret = NULL;
+
+ while (n) {
+ entry = rb_entry(n, struct btrfs_free_space, offset_index);
+
+ if (offset < entry->offset) {
+ if (!contains &&
+ (!ret || entry->offset < ret->offset) &&
+ (bytes <= entry->bytes))
+ ret = entry;
+ n = n->rb_left;
+ } else if (offset > entry->offset) {
+ if ((entry->offset + entry->bytes - 1) >= offset &&
+ bytes <= entry->bytes) {
+ ret = entry;
+ break;
+ }
+ n = n->rb_right;
+ } else {
+ if (bytes > entry->bytes) {
+ n = n->rb_right;
+ continue;
+ }
+ ret = entry;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * return a chunk at least bytes size, as close to offset that we can get.
+ */
+static struct btrfs_free_space *tree_search_bytes(struct rb_root *root,
+ u64 offset, u64 bytes)
+{
+ struct rb_node *n = root->rb_node;
+ struct btrfs_free_space *entry, *ret = NULL;
+
+ while (n) {
+ entry = rb_entry(n, struct btrfs_free_space, bytes_index);
+
+ if (bytes < entry->bytes) {
+ /*
+ * We prefer to get a hole size as close to the size we
+ * are asking for so we don't take small slivers out of
+ * huge holes, but we also want to get as close to the
+ * offset as possible so we don't have a whole lot of
+ * fragmentation.
+ */
+ if (offset <= entry->offset) {
+ if (!ret)
+ ret = entry;
+ else if (entry->bytes < ret->bytes)
+ ret = entry;
+ else if (entry->offset < ret->offset)
+ ret = entry;
+ }
+ n = n->rb_left;
+ } else if (bytes > entry->bytes) {
+ n = n->rb_right;
+ } else {
+ /*
+ * Ok we may have multiple chunks of the wanted size,
+ * so we don't want to take the first one we find, we
+ * want to take the one closest to our given offset, so
+ * keep searching just in case theres a better match.
+ */
+ n = n->rb_right;
+ if (offset > entry->offset)
+ continue;
+ else if (!ret || entry->offset < ret->offset)
+ ret = entry;
+ }
+ }
+
+ return ret;
+}
+
+static void unlink_free_space(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_space *info)
+{
+ rb_erase(&info->offset_index, &block_group->free_space_offset);
+ rb_erase(&info->bytes_index, &block_group->free_space_bytes);
+}
+
+static int link_free_space(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_space *info)
+{
+ int ret = 0;
+
+
+ ret = tree_insert_offset(&block_group->free_space_offset, info->offset,
+ &info->offset_index);
+ if (ret)
+ return ret;
+
+ ret = tree_insert_bytes(&block_group->free_space_bytes, info->bytes,
+ &info->bytes_index);
+ if (ret)
+ return ret;
+
+ return ret;
+}
+
+static int __btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ struct btrfs_free_space *right_info;
+ struct btrfs_free_space *left_info;
+ struct btrfs_free_space *info = NULL;
+ struct btrfs_free_space *alloc_info;
+ int ret = 0;
+
+ alloc_info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
+ if (!alloc_info)
+ return -ENOMEM;
+
+ /*
+ * first we want to see if there is free space adjacent to the range we
+ * are adding, if there is remove that struct and add a new one to
+ * cover the entire range
+ */
+ right_info = tree_search_offset(&block_group->free_space_offset,
+ offset+bytes, 0, 1);
+ left_info = tree_search_offset(&block_group->free_space_offset,
+ offset-1, 0, 1);
+
+ if (right_info && right_info->offset == offset+bytes) {
+ unlink_free_space(block_group, right_info);
+ info = right_info;
+ info->offset = offset;
+ info->bytes += bytes;
+ } else if (right_info && right_info->offset != offset+bytes) {
+ printk(KERN_ERR "adding space in the middle of an existing "
+ "free space area. existing: offset=%Lu, bytes=%Lu. "
+ "new: offset=%Lu, bytes=%Lu\n", right_info->offset,
+ right_info->bytes, offset, bytes);
+ BUG();
+ }
+
+ if (left_info) {
+ unlink_free_space(block_group, left_info);
+
+ if (unlikely((left_info->offset + left_info->bytes) !=
+ offset)) {
+ printk(KERN_ERR "free space to the left of new free "
+ "space isn't quite right. existing: offset=%Lu,"
+ " bytes=%Lu. new: offset=%Lu, bytes=%Lu\n",
+ left_info->offset, left_info->bytes, offset,
+ bytes);
+ BUG();
+ }
+
+ if (info) {
+ info->offset = left_info->offset;
+ info->bytes += left_info->bytes;
+ kfree(left_info);
+ } else {
+ info = left_info;
+ info->bytes += bytes;
+ }
+ }
+
+ if (info) {
+ ret = link_free_space(block_group, info);
+ if (!ret)
+ info = NULL;
+ goto out;
+ }
+
+ info = alloc_info;
+ alloc_info = NULL;
+ info->offset = offset;
+ info->bytes = bytes;
+
+ ret = link_free_space(block_group, info);
+ if (ret)
+ kfree(info);
+out:
+ if (ret) {
+ printk(KERN_ERR "btrfs: unable to add free space :%d\n", ret);
+ if (ret == -EEXIST)
+ BUG();
+ }
+
+ if (alloc_info)
+ kfree(alloc_info);
+
+ return ret;
+}
+
+static int
+__btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ struct btrfs_free_space *info;
+ int ret = 0;
+
+ info = tree_search_offset(&block_group->free_space_offset, offset, 0,
+ 1);
+
+ if (info && info->offset == offset) {
+ if (info->bytes < bytes) {
+ printk(KERN_ERR "Found free space at %Lu, size %Lu,"
+ "trying to use %Lu\n",
+ info->offset, info->bytes, bytes);
+ WARN_ON(1);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ unlink_free_space(block_group, info);
+
+ if (info->bytes == bytes) {
+ kfree(info);
+ goto out;
+ }
+
+ info->offset += bytes;
+ info->bytes -= bytes;
+
+ ret = link_free_space(block_group, info);
+ BUG_ON(ret);
+ } else if (info && info->offset < offset &&
+ info->offset + info->bytes >= offset + bytes) {
+ u64 old_start = info->offset;
+ /*
+ * we're freeing space in the middle of the info,
+ * this can happen during tree log replay
+ *
+ * first unlink the old info and then
+ * insert it again after the hole we're creating
+ */
+ unlink_free_space(block_group, info);
+ if (offset + bytes < info->offset + info->bytes) {
+ u64 old_end = info->offset + info->bytes;
+
+ info->offset = offset + bytes;
+ info->bytes = old_end - info->offset;
+ ret = link_free_space(block_group, info);
+ BUG_ON(ret);
+ } else {
+ /* the hole we're creating ends at the end
+ * of the info struct, just free the info
+ */
+ kfree(info);
+ }
+
+ /* step two, insert a new info struct to cover anything
+ * before the hole
+ */
+ ret = __btrfs_add_free_space(block_group, old_start,
+ offset - old_start);
+ BUG_ON(ret);
+ } else {
+ WARN_ON(1);
+ }
+out:
+ return ret;
+}
+
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ int ret;
+ struct btrfs_free_space *sp;
+
+ mutex_lock(&block_group->alloc_mutex);
+ ret = __btrfs_add_free_space(block_group, offset, bytes);
+ sp = tree_search_offset(&block_group->free_space_offset, offset, 0, 1);
+ BUG_ON(!sp);
+ mutex_unlock(&block_group->alloc_mutex);
+
+ return ret;
+}
+
+int btrfs_add_free_space_lock(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ int ret;
+ struct btrfs_free_space *sp;
+
+ ret = __btrfs_add_free_space(block_group, offset, bytes);
+ sp = tree_search_offset(&block_group->free_space_offset, offset, 0, 1);
+ BUG_ON(!sp);
+
+ return ret;
+}
+
+int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ int ret = 0;
+
+ mutex_lock(&block_group->alloc_mutex);
+ ret = __btrfs_remove_free_space(block_group, offset, bytes);
+ mutex_unlock(&block_group->alloc_mutex);
+
+ return ret;
+}
+
+int btrfs_remove_free_space_lock(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ int ret;
+
+ ret = __btrfs_remove_free_space(block_group, offset, bytes);
+
+ return ret;
+}
+
+void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
+ u64 bytes)
+{
+ struct btrfs_free_space *info;
+ struct rb_node *n;
+ int count = 0;
+
+ for (n = rb_first(&block_group->free_space_offset); n; n = rb_next(n)) {
+ info = rb_entry(n, struct btrfs_free_space, offset_index);
+ if (info->bytes >= bytes)
+ count++;
+ //printk(KERN_INFO "offset=%Lu, bytes=%Lu\n", info->offset,
+ // info->bytes);
+ }
+ printk(KERN_INFO "%d blocks of free space at or bigger than bytes is"
+ "\n", count);
+}
+
+u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_free_space *info;
+ struct rb_node *n;
+ u64 ret = 0;
+
+ for (n = rb_first(&block_group->free_space_offset); n;
+ n = rb_next(n)) {
+ info = rb_entry(n, struct btrfs_free_space, offset_index);
+ ret += info->bytes;
+ }
+
+ return ret;
+}
+
+void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_free_space *info;
+ struct rb_node *node;
+
+ mutex_lock(&block_group->alloc_mutex);
+ while ((node = rb_last(&block_group->free_space_bytes)) != NULL) {
+ info = rb_entry(node, struct btrfs_free_space, bytes_index);
+ unlink_free_space(block_group, info);
+ kfree(info);
+ if (need_resched()) {
+ mutex_unlock(&block_group->alloc_mutex);
+ cond_resched();
+ mutex_lock(&block_group->alloc_mutex);
+ }
+ }
+ mutex_unlock(&block_group->alloc_mutex);
+}
+
+struct btrfs_free_space *btrfs_find_free_space_offset(struct
+ btrfs_block_group_cache
+ *block_group, u64 offset,
+ u64 bytes)
+{
+ struct btrfs_free_space *ret;
+
+ mutex_lock(&block_group->alloc_mutex);
+ ret = tree_search_offset(&block_group->free_space_offset, offset,
+ bytes, 0);
+ mutex_unlock(&block_group->alloc_mutex);
+
+ return ret;
+}
+
+struct btrfs_free_space *btrfs_find_free_space_bytes(struct
+ btrfs_block_group_cache
+ *block_group, u64 offset,
+ u64 bytes)
+{
+ struct btrfs_free_space *ret;
+
+ mutex_lock(&block_group->alloc_mutex);
+
+ ret = tree_search_bytes(&block_group->free_space_bytes, offset, bytes);
+ mutex_unlock(&block_group->alloc_mutex);
+
+ return ret;
+}
+
+struct btrfs_free_space *btrfs_find_free_space(struct btrfs_block_group_cache
+ *block_group, u64 offset,
+ u64 bytes)
+{
+ struct btrfs_free_space *ret = NULL;
+
+ ret = tree_search_offset(&block_group->free_space_offset, offset,
+ bytes, 0);
+ if (!ret)
+ ret = tree_search_bytes(&block_group->free_space_bytes,
+ offset, bytes);
+
+ return ret;
+}
diff --git a/fs/btrfs/hash.h b/fs/btrfs/hash.h
new file mode 100644
index 0000000..2a020b2
--- /dev/null
+++ b/fs/btrfs/hash.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __HASH__
+#define __HASH__
+
+#include "crc32c.h"
+static inline u64 btrfs_name_hash(const char *name, int len)
+{
+ return btrfs_crc32c((u32)~1, name, len);
+}
+#endif
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
new file mode 100644
index 0000000..d93451c
--- /dev/null
+++ b/fs/btrfs/inode-item.c
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+int find_name_in_backref(struct btrfs_path *path, const char * name,
+ int name_len, struct btrfs_inode_ref **ref_ret)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_inode_ref *ref;
+ unsigned long ptr;
+ unsigned long name_ptr;
+ u32 item_size;
+ u32 cur_offset = 0;
+ int len;
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ while (cur_offset < item_size) {
+ ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
+ len = btrfs_inode_ref_name_len(leaf, ref);
+ name_ptr = (unsigned long)(ref + 1);
+ cur_offset += len + sizeof(*ref);
+ if (len != name_len)
+ continue;
+ if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
+ *ref_ret = ref;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, u64 *index)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_inode_ref *ref;
+ struct extent_buffer *leaf;
+ unsigned long ptr;
+ unsigned long item_start;
+ u32 item_size;
+ u32 sub_item_len;
+ int ret;
+ int del_len = name_len + sizeof(*ref);
+
+ key.objectid = inode_objectid;
+ key.offset = ref_objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ } else if (ret < 0) {
+ goto out;
+ }
+ if (!find_name_in_backref(path, name, name_len, &ref)) {
+ ret = -ENOENT;
+ goto out;
+ }
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+
+ if (index)
+ *index = btrfs_inode_ref_index(leaf, ref);
+
+ if (del_len == item_size) {
+ ret = btrfs_del_item(trans, root, path);
+ goto out;
+ }
+ ptr = (unsigned long)ref;
+ sub_item_len = name_len + sizeof(*ref);
+ item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
+ item_size - (ptr + sub_item_len - item_start));
+ ret = btrfs_truncate_item(trans, root, path,
+ item_size - sub_item_len, 1);
+ BUG_ON(ret);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, u64 index)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_inode_ref *ref;
+ unsigned long ptr;
+ int ret;
+ int ins_len = name_len + sizeof(*ref);
+
+ key.objectid = inode_objectid;
+ key.offset = ref_objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ ins_len);
+ if (ret == -EEXIST) {
+ u32 old_size;
+
+ if (find_name_in_backref(path, name, name_len, &ref))
+ goto out;
+
+ old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+ ret = btrfs_extend_item(trans, root, path, ins_len);
+ BUG_ON(ret);
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_ref);
+ ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ btrfs_set_inode_ref_index(path->nodes[0], ref, index);
+ ptr = (unsigned long)(ref + 1);
+ ret = 0;
+ } else if (ret < 0) {
+ goto out;
+ } else {
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_ref);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ btrfs_set_inode_ref_index(path->nodes[0], ref, index);
+ ptr = (unsigned long)(ref + 1);
+ }
+ write_extent_buffer(path->nodes[0], name, ptr, name_len);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid)
+{
+ struct btrfs_key key;
+ int ret;
+ key.objectid = objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.offset = 0;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(struct btrfs_inode_item));
+ if (ret == 0 && objectid > root->highest_inode)
+ root->highest_inode = objectid;
+ return ret;
+}
+
+int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path,
+ struct btrfs_key *location, int mod)
+{
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+ int ret;
+ int slot;
+ struct extent_buffer *leaf;
+ struct btrfs_key found_key;
+
+ ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
+ if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
+ location->offset == (u64)-1 && path->slots[0] != 0) {
+ slot = path->slots[0] - 1;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.objectid == location->objectid &&
+ btrfs_key_type(&found_key) == btrfs_key_type(location)) {
+ path->slots[0]--;
+ return 0;
+ }
+ }
+ return ret;
+}
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
new file mode 100644
index 0000000..80038c5
--- /dev/null
+++ b/fs/btrfs/inode-map.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct extent_buffer *l;
+ struct btrfs_key search_key;
+ struct btrfs_key found_key;
+ int slot;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
+ search_key.type = -1;
+ search_key.offset = (u64)-1;
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+ BUG_ON(ret == 0);
+ if (path->slots[0] > 0) {
+ slot = path->slots[0] - 1;
+ l = path->nodes[0];
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+ *objectid = found_key.objectid;
+ } else {
+ *objectid = BTRFS_FIRST_FREE_OBJECTID;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * walks the btree of allocated inodes and find a hole.
+ */
+int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 dirid, u64 *objectid)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ int ret;
+ int slot = 0;
+ u64 last_ino = 0;
+ int start_found;
+ struct extent_buffer *l;
+ struct btrfs_key search_key;
+ u64 search_start = dirid;
+
+ mutex_lock(&root->objectid_mutex);
+ if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID &&
+ root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) {
+ *objectid = ++root->last_inode_alloc;
+ mutex_unlock(&root->objectid_mutex);
+ return 0;
+ }
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
+ search_key.objectid = search_start;
+ search_key.type = 0;
+ search_key.offset = 0;
+
+ btrfs_init_path(path);
+ start_found = 0;
+ ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+
+ while (1) {
+ l = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto error;
+ if (!start_found) {
+ *objectid = search_start;
+ start_found = 1;
+ goto found;
+ }
+ *objectid = last_ino > search_start ?
+ last_ino : search_start;
+ goto found;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+ if (key.objectid >= search_start) {
+ if (start_found) {
+ if (last_ino < search_start)
+ last_ino = search_start;
+ if (key.objectid > last_ino) {
+ *objectid = last_ino;
+ goto found;
+ }
+ } else if (key.objectid > search_start) {
+ *objectid = search_start;
+ goto found;
+ }
+ }
+ if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
+ break;
+
+ start_found = 1;
+ last_ino = key.objectid + 1;
+ path->slots[0]++;
+ }
+ // FIXME -ENOSPC
+ BUG_ON(1);
+found:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ BUG_ON(*objectid < search_start);
+ mutex_unlock(&root->objectid_mutex);
+ return 0;
+error:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ mutex_unlock(&root->objectid_mutex);
+ return ret;
+}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
new file mode 100644
index 0000000..806caac
--- /dev/null
+++ b/fs/btrfs/inode.c
@@ -0,0 +1,5022 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/bit_spinlock.h>
+#include <linux/version.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/falloc.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "ordered-data.h"
+#include "xattr.h"
+#include "compat.h"
+#include "tree-log.h"
+#include "ref-cache.h"
+#include "compression.h"
+
+struct btrfs_iget_args {
+ u64 ino;
+ struct btrfs_root *root;
+};
+
+static struct inode_operations btrfs_dir_inode_operations;
+static struct inode_operations btrfs_symlink_inode_operations;
+static struct inode_operations btrfs_dir_ro_inode_operations;
+static struct inode_operations btrfs_special_inode_operations;
+static struct inode_operations btrfs_file_inode_operations;
+static struct address_space_operations btrfs_aops;
+static struct address_space_operations btrfs_symlink_aops;
+static struct file_operations btrfs_dir_file_operations;
+static struct extent_io_ops btrfs_extent_io_ops;
+
+static struct kmem_cache *btrfs_inode_cachep;
+struct kmem_cache *btrfs_trans_handle_cachep;
+struct kmem_cache *btrfs_transaction_cachep;
+struct kmem_cache *btrfs_bit_radix_cachep;
+struct kmem_cache *btrfs_path_cachep;
+
+#define S_SHIFT 12
+static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
+ [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
+ [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
+ [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
+ [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
+ [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
+ [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
+ [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
+};
+
+static void btrfs_truncate(struct inode *inode);
+static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
+static noinline int cow_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written, int unlock);
+
+/*
+ * a very lame attempt at stopping writes when the FS is 85% full. There
+ * are countless ways this is incorrect, but it is better than nothing.
+ */
+int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
+ int for_del)
+{
+ u64 total;
+ u64 used;
+ u64 thresh;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
+ total = btrfs_super_total_bytes(&root->fs_info->super_copy);
+ used = btrfs_super_bytes_used(&root->fs_info->super_copy);
+ if (for_del)
+ thresh = total * 90;
+ else
+ thresh = total * 85;
+
+ do_div(thresh, 100);
+
+ if (used + root->fs_info->delalloc_bytes + num_required > thresh)
+ ret = -ENOSPC;
+ spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
+ return ret;
+}
+
+/*
+ * this does all the hard work for inserting an inline extent into
+ * the btree. The caller should have done a btrfs_drop_extents so that
+ * no overlapping inline items exist in the btree
+ */
+static int noinline insert_inline_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ u64 start, size_t size, size_t compressed_size,
+ struct page **compressed_pages)
+{
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct page *page = NULL;
+ char *kaddr;
+ unsigned long ptr;
+ struct btrfs_file_extent_item *ei;
+ int err = 0;
+ int ret;
+ size_t cur_size = size;
+ size_t datasize;
+ unsigned long offset;
+ int use_compress = 0;
+
+ if (compressed_size && compressed_pages) {
+ use_compress = 1;
+ cur_size = compressed_size;
+ }
+
+ path = btrfs_alloc_path(); if (!path)
+ return -ENOMEM;
+
+ btrfs_set_trans_block_group(trans, inode);
+
+ key.objectid = inode->i_ino;
+ key.offset = start;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+ inode_add_bytes(inode, size);
+ datasize = btrfs_file_extent_calc_inline_size(cur_size);
+
+ inode_add_bytes(inode, size);
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ datasize);
+ BUG_ON(ret);
+ if (ret) {
+ err = ret;
+ printk("got bad ret %d\n", ret);
+ goto fail;
+ }
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, ei, trans->transid);
+ btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
+ btrfs_set_file_extent_encryption(leaf, ei, 0);
+ btrfs_set_file_extent_other_encoding(leaf, ei, 0);
+ btrfs_set_file_extent_ram_bytes(leaf, ei, size);
+ ptr = btrfs_file_extent_inline_start(ei);
+
+ if (use_compress) {
+ struct page *cpage;
+ int i = 0;
+ while(compressed_size > 0) {
+ cpage = compressed_pages[i];
+ cur_size = min_t(unsigned long, compressed_size,
+ PAGE_CACHE_SIZE);
+
+ kaddr = kmap(cpage);
+ write_extent_buffer(leaf, kaddr, ptr, cur_size);
+ kunmap(cpage);
+
+ i++;
+ ptr += cur_size;
+ compressed_size -= cur_size;
+ }
+ btrfs_set_file_extent_compression(leaf, ei,
+ BTRFS_COMPRESS_ZLIB);
+ } else {
+ page = find_get_page(inode->i_mapping,
+ start >> PAGE_CACHE_SHIFT);
+ btrfs_set_file_extent_compression(leaf, ei, 0);
+ kaddr = kmap_atomic(page, KM_USER0);
+ offset = start & (PAGE_CACHE_SIZE - 1);
+ write_extent_buffer(leaf, kaddr + offset, ptr, size);
+ kunmap_atomic(kaddr, KM_USER0);
+ page_cache_release(page);
+ }
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_free_path(path);
+
+ BTRFS_I(inode)->disk_i_size = inode->i_size;
+ btrfs_update_inode(trans, root, inode);
+ return 0;
+fail:
+ btrfs_free_path(path);
+ return err;
+}
+
+
+/*
+ * conditionally insert an inline extent into the file. This
+ * does the checks required to make sure the data is small enough
+ * to fit as an inline extent.
+ */
+static int cow_file_range_inline(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode, u64 start, u64 end,
+ size_t compressed_size,
+ struct page **compressed_pages)
+{
+ u64 isize = i_size_read(inode);
+ u64 actual_end = min(end + 1, isize);
+ u64 inline_len = actual_end - start;
+ u64 aligned_end = (end + root->sectorsize - 1) &
+ ~((u64)root->sectorsize - 1);
+ u64 hint_byte;
+ u64 data_len = inline_len;
+ int ret;
+
+ if (compressed_size)
+ data_len = compressed_size;
+
+ if (start > 0 ||
+ actual_end >= PAGE_CACHE_SIZE ||
+ data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
+ (!compressed_size &&
+ (actual_end & (root->sectorsize - 1)) == 0) ||
+ end + 1 < isize ||
+ data_len > root->fs_info->max_inline) {
+ return 1;
+ }
+
+ ret = btrfs_drop_extents(trans, root, inode, start,
+ aligned_end, start, &hint_byte);
+ BUG_ON(ret);
+
+ if (isize > actual_end)
+ inline_len = min_t(u64, isize, actual_end);
+ ret = insert_inline_extent(trans, root, inode, start,
+ inline_len, compressed_size,
+ compressed_pages);
+ BUG_ON(ret);
+ btrfs_drop_extent_cache(inode, start, aligned_end, 0);
+ return 0;
+}
+
+struct async_extent {
+ u64 start;
+ u64 ram_size;
+ u64 compressed_size;
+ struct page **pages;
+ unsigned long nr_pages;
+ struct list_head list;
+};
+
+struct async_cow {
+ struct inode *inode;
+ struct btrfs_root *root;
+ struct page *locked_page;
+ u64 start;
+ u64 end;
+ struct list_head extents;
+ struct btrfs_work work;
+};
+
+static noinline int add_async_extent(struct async_cow *cow,
+ u64 start, u64 ram_size,
+ u64 compressed_size,
+ struct page **pages,
+ unsigned long nr_pages)
+{
+ struct async_extent *async_extent;
+
+ async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
+ async_extent->start = start;
+ async_extent->ram_size = ram_size;
+ async_extent->compressed_size = compressed_size;
+ async_extent->pages = pages;
+ async_extent->nr_pages = nr_pages;
+ list_add_tail(&async_extent->list, &cow->extents);
+ return 0;
+}
+
+/*
+ * we create compressed extents in two phases. The first
+ * phase compresses a range of pages that have already been
+ * locked (both pages and state bits are locked).
+ *
+ * This is done inside an ordered work queue, and the compression
+ * is spread across many cpus. The actual IO submission is step
+ * two, and the ordered work queue takes care of making sure that
+ * happens in the same order things were put onto the queue by
+ * writepages and friends.
+ *
+ * If this code finds it can't get good compression, it puts an
+ * entry onto the work queue to write the uncompressed bytes. This
+ * makes sure that both compressed inodes and uncompressed inodes
+ * are written in the same order that pdflush sent them down.
+ */
+static noinline int compress_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end,
+ struct async_cow *async_cow,
+ int *num_added)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ u64 num_bytes;
+ u64 orig_start;
+ u64 disk_num_bytes;
+ u64 blocksize = root->sectorsize;
+ u64 actual_end;
+ int ret = 0;
+ struct page **pages = NULL;
+ unsigned long nr_pages;
+ unsigned long nr_pages_ret = 0;
+ unsigned long total_compressed = 0;
+ unsigned long total_in = 0;
+ unsigned long max_compressed = 128 * 1024;
+ unsigned long max_uncompressed = 128 * 1024;
+ int i;
+ int will_compress;
+
+ orig_start = start;
+
+again:
+ will_compress = 0;
+ nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
+ nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
+
+ actual_end = min_t(u64, i_size_read(inode), end + 1);
+ total_compressed = actual_end - start;
+
+ /* we want to make sure that amount of ram required to uncompress
+ * an extent is reasonable, so we limit the total size in ram
+ * of a compressed extent to 128k. This is a crucial number
+ * because it also controls how easily we can spread reads across
+ * cpus for decompression.
+ *
+ * We also want to make sure the amount of IO required to do
+ * a random read is reasonably small, so we limit the size of
+ * a compressed extent to 128k.
+ */
+ total_compressed = min(total_compressed, max_uncompressed);
+ num_bytes = (end - start + blocksize) & ~(blocksize - 1);
+ num_bytes = max(blocksize, num_bytes);
+ disk_num_bytes = num_bytes;
+ total_in = 0;
+ ret = 0;
+
+ /*
+ * we do compression for mount -o compress and when the
+ * inode has not been flagged as nocompress. This flag can
+ * change at any time if we discover bad compression ratios.
+ */
+ if (!btrfs_test_flag(inode, NOCOMPRESS) &&
+ btrfs_test_opt(root, COMPRESS)) {
+ WARN_ON(pages);
+ pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
+
+ ret = btrfs_zlib_compress_pages(inode->i_mapping, start,
+ total_compressed, pages,
+ nr_pages, &nr_pages_ret,
+ &total_in,
+ &total_compressed,
+ max_compressed);
+
+ if (!ret) {
+ unsigned long offset = total_compressed &
+ (PAGE_CACHE_SIZE - 1);
+ struct page *page = pages[nr_pages_ret - 1];
+ char *kaddr;
+
+ /* zero the tail end of the last page, we might be
+ * sending it down to disk
+ */
+ if (offset) {
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + offset, 0,
+ PAGE_CACHE_SIZE - offset);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+ will_compress = 1;
+ }
+ }
+ if (start == 0) {
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+ btrfs_set_trans_block_group(trans, inode);
+
+ /* lets try to make an inline extent */
+ if (ret || total_in < (actual_end - start)) {
+ /* we didn't compress the entire range, try
+ * to make an uncompressed inline extent.
+ */
+ ret = cow_file_range_inline(trans, root, inode,
+ start, end, 0, NULL);
+ } else {
+ /* try making a compressed inline extent */
+ ret = cow_file_range_inline(trans, root, inode,
+ start, end,
+ total_compressed, pages);
+ }
+ btrfs_end_transaction(trans, root);
+ if (ret == 0) {
+ /*
+ * inline extent creation worked, we don't need
+ * to create any more async work items. Unlock
+ * and free up our temp pages.
+ */
+ extent_clear_unlock_delalloc(inode,
+ &BTRFS_I(inode)->io_tree,
+ start, end, NULL, 1, 0,
+ 0, 1, 1, 1);
+ ret = 0;
+ goto free_pages_out;
+ }
+ }
+
+ if (will_compress) {
+ /*
+ * we aren't doing an inline extent round the compressed size
+ * up to a block size boundary so the allocator does sane
+ * things
+ */
+ total_compressed = (total_compressed + blocksize - 1) &
+ ~(blocksize - 1);
+
+ /*
+ * one last check to make sure the compression is really a
+ * win, compare the page count read with the blocks on disk
+ */
+ total_in = (total_in + PAGE_CACHE_SIZE - 1) &
+ ~(PAGE_CACHE_SIZE - 1);
+ if (total_compressed >= total_in) {
+ will_compress = 0;
+ } else {
+ disk_num_bytes = total_compressed;
+ num_bytes = total_in;
+ }
+ }
+ if (!will_compress && pages) {
+ /*
+ * the compression code ran but failed to make things smaller,
+ * free any pages it allocated and our page pointer array
+ */
+ for (i = 0; i < nr_pages_ret; i++) {
+ WARN_ON(pages[i]->mapping);
+ page_cache_release(pages[i]);
+ }
+ kfree(pages);
+ pages = NULL;
+ total_compressed = 0;
+ nr_pages_ret = 0;
+
+ /* flag the file so we don't compress in the future */
+ btrfs_set_flag(inode, NOCOMPRESS);
+ }
+ if (will_compress) {
+ *num_added += 1;
+
+ /* the async work queues will take care of doing actual
+ * allocation on disk for these compressed pages,
+ * and will submit them to the elevator.
+ */
+ add_async_extent(async_cow, start, num_bytes,
+ total_compressed, pages, nr_pages_ret);
+
+ if (start + num_bytes < end) {
+ start += num_bytes;
+ pages = NULL;
+ cond_resched();
+ goto again;
+ }
+ } else {
+ /*
+ * No compression, but we still need to write the pages in
+ * the file we've been given so far. redirty the locked
+ * page if it corresponds to our extent and set things up
+ * for the async work queue to run cow_file_range to do
+ * the normal delalloc dance
+ */
+ if (page_offset(locked_page) >= start &&
+ page_offset(locked_page) <= end) {
+ __set_page_dirty_nobuffers(locked_page);
+ /* unlocked later on in the async handlers */
+ }
+ add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0);
+ *num_added += 1;
+ }
+
+out:
+ return 0;
+
+free_pages_out:
+ for (i = 0; i < nr_pages_ret; i++) {
+ WARN_ON(pages[i]->mapping);
+ page_cache_release(pages[i]);
+ }
+ if (pages)
+ kfree(pages);
+
+ goto out;
+}
+
+/*
+ * phase two of compressed writeback. This is the ordered portion
+ * of the code, which only gets called in the order the work was
+ * queued. We walk all the async extents created by compress_file_range
+ * and send them down to the disk.
+ */
+static noinline int submit_compressed_extents(struct inode *inode,
+ struct async_cow *async_cow)
+{
+ struct async_extent *async_extent;
+ u64 alloc_hint = 0;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key ins;
+ struct extent_map *em;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_io_tree *io_tree;
+ int ret;
+
+ if (list_empty(&async_cow->extents))
+ return 0;
+
+ trans = btrfs_join_transaction(root, 1);
+
+ while(!list_empty(&async_cow->extents)) {
+ async_extent = list_entry(async_cow->extents.next,
+ struct async_extent, list);
+ list_del(&async_extent->list);
+
+ io_tree = &BTRFS_I(inode)->io_tree;
+
+ /* did the compression code fall back to uncompressed IO? */
+ if (!async_extent->pages) {
+ int page_started = 0;
+ unsigned long nr_written = 0;
+
+ lock_extent(io_tree, async_extent->start,
+ async_extent->start + async_extent->ram_size - 1,
+ GFP_NOFS);
+
+ /* allocate blocks */
+ cow_file_range(inode, async_cow->locked_page,
+ async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ &page_started, &nr_written, 0);
+
+ /*
+ * if page_started, cow_file_range inserted an
+ * inline extent and took care of all the unlocking
+ * and IO for us. Otherwise, we need to submit
+ * all those pages down to the drive.
+ */
+ if (!page_started)
+ extent_write_locked_range(io_tree,
+ inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ btrfs_get_extent,
+ WB_SYNC_ALL);
+ kfree(async_extent);
+ cond_resched();
+ continue;
+ }
+
+ lock_extent(io_tree, async_extent->start,
+ async_extent->start + async_extent->ram_size - 1,
+ GFP_NOFS);
+ /*
+ * here we're doing allocation and writeback of the
+ * compressed pages
+ */
+ btrfs_drop_extent_cache(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, 0);
+
+ ret = btrfs_reserve_extent(trans, root,
+ async_extent->compressed_size,
+ async_extent->compressed_size,
+ 0, alloc_hint,
+ (u64)-1, &ins, 1);
+ BUG_ON(ret);
+ em = alloc_extent_map(GFP_NOFS);
+ em->start = async_extent->start;
+ em->len = async_extent->ram_size;
+ em->orig_start = em->start;
+
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+
+ while(1) {
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, 0);
+ }
+
+ ret = btrfs_add_ordered_extent(inode, async_extent->start,
+ ins.objectid,
+ async_extent->ram_size,
+ ins.offset,
+ BTRFS_ORDERED_COMPRESSED);
+ BUG_ON(ret);
+
+ btrfs_end_transaction(trans, root);
+
+ /*
+ * clear dirty, set writeback and unlock the pages.
+ */
+ extent_clear_unlock_delalloc(inode,
+ &BTRFS_I(inode)->io_tree,
+ async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ NULL, 1, 1, 0, 1, 1, 0);
+
+ ret = btrfs_submit_compressed_write(inode,
+ async_extent->start,
+ async_extent->ram_size,
+ ins.objectid,
+ ins.offset, async_extent->pages,
+ async_extent->nr_pages);
+
+ BUG_ON(ret);
+ trans = btrfs_join_transaction(root, 1);
+ alloc_hint = ins.objectid + ins.offset;
+ kfree(async_extent);
+ cond_resched();
+ }
+
+ btrfs_end_transaction(trans, root);
+ return 0;
+}
+
+/*
+ * when extent_io.c finds a delayed allocation range in the file,
+ * the call backs end up in this code. The basic idea is to
+ * allocate extents on disk for the range, and create ordered data structs
+ * in ram to track those extents.
+ *
+ * locked_page is the page that writepage had locked already. We use
+ * it to make sure we don't do extra locks or unlocks.
+ *
+ * *page_started is set to one if we unlock locked_page and do everything
+ * required to start IO on it. It may be clean and already done with
+ * IO when we return.
+ */
+static noinline int cow_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written,
+ int unlock)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ u64 alloc_hint = 0;
+ u64 num_bytes;
+ unsigned long ram_size;
+ u64 disk_num_bytes;
+ u64 cur_alloc_size;
+ u64 blocksize = root->sectorsize;
+ u64 actual_end;
+ struct btrfs_key ins;
+ struct extent_map *em;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ int ret = 0;
+
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+ btrfs_set_trans_block_group(trans, inode);
+
+ actual_end = min_t(u64, i_size_read(inode), end + 1);
+
+ num_bytes = (end - start + blocksize) & ~(blocksize - 1);
+ num_bytes = max(blocksize, num_bytes);
+ disk_num_bytes = num_bytes;
+ ret = 0;
+
+ if (start == 0) {
+ /* lets try to make an inline extent */
+ ret = cow_file_range_inline(trans, root, inode,
+ start, end, 0, NULL);
+ if (ret == 0) {
+ extent_clear_unlock_delalloc(inode,
+ &BTRFS_I(inode)->io_tree,
+ start, end, NULL, 1, 1,
+ 1, 1, 1, 1);
+ *nr_written = *nr_written +
+ (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
+ *page_started = 1;
+ ret = 0;
+ goto out;
+ }
+ }
+
+ BUG_ON(disk_num_bytes >
+ btrfs_super_total_bytes(&root->fs_info->super_copy));
+
+ btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
+
+ while(disk_num_bytes > 0) {
+ cur_alloc_size = min(disk_num_bytes, root->fs_info->max_extent);
+ ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
+ root->sectorsize, 0, alloc_hint,
+ (u64)-1, &ins, 1);
+ if (ret) {
+ BUG();
+ }
+ em = alloc_extent_map(GFP_NOFS);
+ em->start = start;
+ em->orig_start = em->start;
+
+ ram_size = ins.offset;
+ em->len = ins.offset;
+
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+
+ while(1) {
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, start,
+ start + ram_size - 1, 0);
+ }
+
+ cur_alloc_size = ins.offset;
+ ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
+ ram_size, cur_alloc_size, 0);
+ BUG_ON(ret);
+
+ if (disk_num_bytes < cur_alloc_size) {
+ printk("num_bytes %Lu cur_alloc %Lu\n", disk_num_bytes,
+ cur_alloc_size);
+ break;
+ }
+ /* we're not doing compressed IO, don't unlock the first
+ * page (which the caller expects to stay locked), don't
+ * clear any dirty bits and don't set any writeback bits
+ */
+ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
+ start, start + ram_size - 1,
+ locked_page, unlock, 1,
+ 1, 0, 0, 0);
+ disk_num_bytes -= cur_alloc_size;
+ num_bytes -= cur_alloc_size;
+ alloc_hint = ins.objectid + ins.offset;
+ start += cur_alloc_size;
+ }
+out:
+ ret = 0;
+ btrfs_end_transaction(trans, root);
+
+ return ret;
+}
+
+/*
+ * work queue call back to started compression on a file and pages
+ */
+static noinline void async_cow_start(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ int num_added = 0;
+ async_cow = container_of(work, struct async_cow, work);
+
+ compress_file_range(async_cow->inode, async_cow->locked_page,
+ async_cow->start, async_cow->end, async_cow,
+ &num_added);
+ if (num_added == 0)
+ async_cow->inode = NULL;
+}
+
+/*
+ * work queue call back to submit previously compressed pages
+ */
+static noinline void async_cow_submit(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ struct btrfs_root *root;
+ unsigned long nr_pages;
+
+ async_cow = container_of(work, struct async_cow, work);
+
+ root = async_cow->root;
+ nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+
+ atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
+
+ if (atomic_read(&root->fs_info->async_delalloc_pages) <
+ 5 * 1042 * 1024 &&
+ waitqueue_active(&root->fs_info->async_submit_wait))
+ wake_up(&root->fs_info->async_submit_wait);
+
+ if (async_cow->inode) {
+ submit_compressed_extents(async_cow->inode, async_cow);
+ }
+}
+
+static noinline void async_cow_free(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ async_cow = container_of(work, struct async_cow, work);
+ kfree(async_cow);
+}
+
+static int cow_file_range_async(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written)
+{
+ struct async_cow *async_cow;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ unsigned long nr_pages;
+ u64 cur_end;
+ int limit = 10 * 1024 * 1042;
+
+ if (!btrfs_test_opt(root, COMPRESS)) {
+ return cow_file_range(inode, locked_page, start, end,
+ page_started, nr_written, 1);
+ }
+
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED |
+ EXTENT_DELALLOC, 1, 0, GFP_NOFS);
+ while(start < end) {
+ async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
+ async_cow->inode = inode;
+ async_cow->root = root;
+ async_cow->locked_page = locked_page;
+ async_cow->start = start;
+
+ if (btrfs_test_flag(inode, NOCOMPRESS))
+ cur_end = end;
+ else
+ cur_end = min(end, start + 512 * 1024 - 1);
+
+ async_cow->end = cur_end;
+ INIT_LIST_HEAD(&async_cow->extents);
+
+ async_cow->work.func = async_cow_start;
+ async_cow->work.ordered_func = async_cow_submit;
+ async_cow->work.ordered_free = async_cow_free;
+ async_cow->work.flags = 0;
+
+ nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+ atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
+
+ btrfs_queue_worker(&root->fs_info->delalloc_workers,
+ &async_cow->work);
+
+ if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->async_delalloc_pages) <
+ limit));
+ }
+
+ while(atomic_read(&root->fs_info->async_submit_draining) &&
+ atomic_read(&root->fs_info->async_delalloc_pages)) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->async_delalloc_pages) ==
+ 0));
+ }
+
+ *nr_written += nr_pages;
+ start = cur_end + 1;
+ }
+ *page_started = 1;
+ return 0;
+}
+
+/*
+ * when nowcow writeback call back. This checks for snapshots or COW copies
+ * of the extents that exist in the file, and COWs the file as required.
+ *
+ * If no cow copies or snapshots exist, we write directly to the existing
+ * blocks on disk
+ */
+static int run_delalloc_nocow(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started, int force,
+ unsigned long *nr_written)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct extent_buffer *leaf;
+ struct btrfs_path *path;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key found_key;
+ u64 cow_start;
+ u64 cur_offset;
+ u64 extent_end;
+ u64 disk_bytenr;
+ u64 num_bytes;
+ int extent_type;
+ int ret;
+ int type;
+ int nocow;
+ int check_prev = 1;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+
+ cow_start = (u64)-1;
+ cur_offset = start;
+ while (1) {
+ ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
+ cur_offset, 0);
+ BUG_ON(ret < 0);
+ if (ret > 0 && path->slots[0] > 0 && check_prev) {
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key,
+ path->slots[0] - 1);
+ if (found_key.objectid == inode->i_ino &&
+ found_key.type == BTRFS_EXTENT_DATA_KEY)
+ path->slots[0]--;
+ }
+ check_prev = 0;
+next_slot:
+ leaf = path->nodes[0];
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ BUG_ON(1);
+ if (ret > 0)
+ break;
+ leaf = path->nodes[0];
+ }
+
+ nocow = 0;
+ disk_bytenr = 0;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid > inode->i_ino ||
+ found_key.type > BTRFS_EXTENT_DATA_KEY ||
+ found_key.offset > end)
+ break;
+
+ if (found_key.offset > cur_offset) {
+ extent_end = found_key.offset;
+ goto out_check;
+ }
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+
+ if (extent_type == BTRFS_FILE_EXTENT_REG ||
+ extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ struct btrfs_block_group_cache *block_group;
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ extent_end = found_key.offset +
+ btrfs_file_extent_num_bytes(leaf, fi);
+ if (extent_end <= start) {
+ path->slots[0]++;
+ goto next_slot;
+ }
+ if (btrfs_file_extent_compression(leaf, fi) ||
+ btrfs_file_extent_encryption(leaf, fi) ||
+ btrfs_file_extent_other_encoding(leaf, fi))
+ goto out_check;
+ if (disk_bytenr == 0)
+ goto out_check;
+ if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
+ goto out_check;
+ if (btrfs_cross_ref_exist(trans, root, disk_bytenr))
+ goto out_check;
+ block_group = btrfs_lookup_block_group(root->fs_info,
+ disk_bytenr);
+ if (!block_group || block_group->ro)
+ goto out_check;
+ disk_bytenr += btrfs_file_extent_offset(leaf, fi);
+ nocow = 1;
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ extent_end = found_key.offset +
+ btrfs_file_extent_inline_len(leaf, fi);
+ extent_end = ALIGN(extent_end, root->sectorsize);
+ } else {
+ BUG_ON(1);
+ }
+out_check:
+ if (extent_end <= start) {
+ path->slots[0]++;
+ goto next_slot;
+ }
+ if (!nocow) {
+ if (cow_start == (u64)-1)
+ cow_start = cur_offset;
+ cur_offset = extent_end;
+ if (cur_offset > end)
+ break;
+ path->slots[0]++;
+ goto next_slot;
+ }
+
+ btrfs_release_path(root, path);
+ if (cow_start != (u64)-1) {
+ ret = cow_file_range(inode, locked_page, cow_start,
+ found_key.offset - 1, page_started,
+ nr_written, 1);
+ BUG_ON(ret);
+ cow_start = (u64)-1;
+ }
+
+ disk_bytenr += cur_offset - found_key.offset;
+ num_bytes = min(end + 1, extent_end) - cur_offset;
+ if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ struct extent_map *em;
+ struct extent_map_tree *em_tree;
+ em_tree = &BTRFS_I(inode)->extent_tree;
+ em = alloc_extent_map(GFP_NOFS);
+ em->start = cur_offset;
+ em->orig_start = em->start;
+ em->len = num_bytes;
+ em->block_len = num_bytes;
+ em->block_start = disk_bytenr;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ while (1) {
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, em->start,
+ em->start + em->len - 1, 0);
+ }
+ type = BTRFS_ORDERED_PREALLOC;
+ } else {
+ type = BTRFS_ORDERED_NOCOW;
+ }
+
+ ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
+ num_bytes, num_bytes, type);
+ BUG_ON(ret);
+
+ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
+ cur_offset, cur_offset + num_bytes - 1,
+ locked_page, 1, 1, 1, 0, 0, 0);
+ cur_offset = extent_end;
+ if (cur_offset > end)
+ break;
+ }
+ btrfs_release_path(root, path);
+
+ if (cur_offset <= end && cow_start == (u64)-1)
+ cow_start = cur_offset;
+ if (cow_start != (u64)-1) {
+ ret = cow_file_range(inode, locked_page, cow_start, end,
+ page_started, nr_written, 1);
+ BUG_ON(ret);
+ }
+
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ btrfs_free_path(path);
+ return 0;
+}
+
+/*
+ * extent_io.c call back to do delayed allocation processing
+ */
+static int run_delalloc_range(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ if (btrfs_test_opt(root, NODATACOW) ||
+ btrfs_test_flag(inode, NODATACOW))
+ ret = run_delalloc_nocow(inode, locked_page, start, end,
+ page_started, 0, nr_written);
+ else if (btrfs_test_flag(inode, PREALLOC))
+ ret = run_delalloc_nocow(inode, locked_page, start, end,
+ page_started, 1, nr_written);
+ else
+ ret = cow_file_range_async(inode, locked_page, start, end,
+ page_started, nr_written);
+
+ return ret;
+}
+
+/*
+ * extent_io.c set_bit_hook, used to track delayed allocation
+ * bytes in this file, and to maintain the list of inodes that
+ * have pending delalloc work to be done.
+ */
+int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
+ unsigned long old, unsigned long bits)
+{
+ unsigned long flags;
+ if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
+ BTRFS_I(inode)->delalloc_bytes += end - start + 1;
+ root->fs_info->delalloc_bytes += end - start + 1;
+ if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
+ list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
+ &root->fs_info->delalloc_inodes);
+ }
+ spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
+ }
+ return 0;
+}
+
+/*
+ * extent_io.c clear_bit_hook, see set_bit_hook for why
+ */
+int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
+ unsigned long old, unsigned long bits)
+{
+ if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ unsigned long flags;
+
+ spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
+ if (end - start + 1 > root->fs_info->delalloc_bytes) {
+ printk("warning: delalloc account %Lu %Lu\n",
+ end - start + 1, root->fs_info->delalloc_bytes);
+ root->fs_info->delalloc_bytes = 0;
+ BTRFS_I(inode)->delalloc_bytes = 0;
+ } else {
+ root->fs_info->delalloc_bytes -= end - start + 1;
+ BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
+ }
+ if (BTRFS_I(inode)->delalloc_bytes == 0 &&
+ !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
+ list_del_init(&BTRFS_I(inode)->delalloc_inodes);
+ }
+ spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
+ }
+ return 0;
+}
+
+/*
+ * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
+ * we don't create bios that span stripes or chunks
+ */
+int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
+ size_t size, struct bio *bio,
+ unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+ struct btrfs_mapping_tree *map_tree;
+ u64 logical = (u64)bio->bi_sector << 9;
+ u64 length = 0;
+ u64 map_length;
+ int ret;
+
+ if (bio_flags & EXTENT_BIO_COMPRESSED)
+ return 0;
+
+ length = bio->bi_size;
+ map_tree = &root->fs_info->mapping_tree;
+ map_length = length;
+ ret = btrfs_map_block(map_tree, READ, logical,
+ &map_length, NULL, 0);
+
+ if (map_length < length + size) {
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * in order to insert checksums into the metadata in large chunks,
+ * we wait until bio submission time. All the pages in the bio are
+ * checksummed and sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the cums attached on the ordered extent record
+ * are inserted into the btree
+ */
+int __btrfs_submit_bio_start(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ ret = btrfs_csum_one_bio(root, inode, bio);
+ BUG_ON(ret);
+ return 0;
+}
+
+/*
+ * in order to insert checksums into the metadata in large chunks,
+ * we wait until bio submission time. All the pages in the bio are
+ * checksummed and sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the cums attached on the ordered extent record
+ * are inserted into the btree
+ */
+int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ return btrfs_map_bio(root, rw, bio, mirror_num, 1);
+}
+
+/*
+ * extent_io.c submission hook. This does the right thing for csum calculation on write,
+ * or reading the csums from the tree before a read
+ */
+int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+ int skip_sum;
+
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
+ BUG_ON(ret);
+
+ skip_sum = btrfs_test_opt(root, NODATASUM) ||
+ btrfs_test_flag(inode, NODATASUM);
+
+ if (!(rw & (1 << BIO_RW))) {
+
+ if (bio_flags & EXTENT_BIO_COMPRESSED)
+ return btrfs_submit_compressed_read(inode, bio,
+ mirror_num, bio_flags);
+ else if (!skip_sum)
+ btrfs_lookup_bio_sums(root, inode, bio);
+ goto mapit;
+ } else if (!skip_sum) {
+ /* we're doing a write, do the async checksumming */
+ return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
+ inode, rw, bio, mirror_num,
+ bio_flags, __btrfs_submit_bio_start,
+ __btrfs_submit_bio_done);
+ }
+
+mapit:
+ return btrfs_map_bio(root, rw, bio, mirror_num, 0);
+}
+
+/*
+ * given a list of ordered sums record them in the inode. This happens
+ * at IO completion time based on sums calculated at bio submission time.
+ */
+static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 file_offset,
+ struct list_head *list)
+{
+ struct list_head *cur;
+ struct btrfs_ordered_sum *sum;
+
+ btrfs_set_trans_block_group(trans, inode);
+ list_for_each(cur, list) {
+ sum = list_entry(cur, struct btrfs_ordered_sum, list);
+ btrfs_csum_file_blocks(trans, BTRFS_I(inode)->root,
+ inode, sum);
+ }
+ return 0;
+}
+
+int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end)
+{
+ if ((end & (PAGE_CACHE_SIZE - 1)) == 0) {
+ WARN_ON(1);
+ }
+ return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
+ GFP_NOFS);
+}
+
+/* see btrfs_writepage_start_hook for details on why this is required */
+struct btrfs_writepage_fixup {
+ struct page *page;
+ struct btrfs_work work;
+};
+
+void btrfs_writepage_fixup_worker(struct btrfs_work *work)
+{
+ struct btrfs_writepage_fixup *fixup;
+ struct btrfs_ordered_extent *ordered;
+ struct page *page;
+ struct inode *inode;
+ u64 page_start;
+ u64 page_end;
+
+ fixup = container_of(work, struct btrfs_writepage_fixup, work);
+ page = fixup->page;
+again:
+ lock_page(page);
+ if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
+ ClearPageChecked(page);
+ goto out_page;
+ }
+
+ inode = page->mapping->host;
+ page_start = page_offset(page);
+ page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
+
+ lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
+
+ /* already ordered? We're done */
+ if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+ EXTENT_ORDERED, 0)) {
+ goto out;
+ }
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(&BTRFS_I(inode)->io_tree, page_start,
+ page_end, GFP_NOFS);
+ unlock_page(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ goto again;
+ }
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+ ClearPageChecked(page);
+out:
+ unlock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
+out_page:
+ unlock_page(page);
+ page_cache_release(page);
+}
+
+/*
+ * There are a few paths in the higher layers of the kernel that directly
+ * set the page dirty bit without asking the filesystem if it is a
+ * good idea. This causes problems because we want to make sure COW
+ * properly happens and the data=ordered rules are followed.
+ *
+ * In our case any range that doesn't have the ORDERED bit set
+ * hasn't been properly setup for IO. We kick off an async process
+ * to fix it up. The async helper will wait for ordered extents, set
+ * the delalloc bit and make it safe to write the page.
+ */
+int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
+{
+ struct inode *inode = page->mapping->host;
+ struct btrfs_writepage_fixup *fixup;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
+ EXTENT_ORDERED, 0);
+ if (ret)
+ return 0;
+
+ if (PageChecked(page))
+ return -EAGAIN;
+
+ fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
+ if (!fixup)
+ return -EAGAIN;
+
+ SetPageChecked(page);
+ page_cache_get(page);
+ fixup->work.func = btrfs_writepage_fixup_worker;
+ fixup->page = page;
+ btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
+ return -EAGAIN;
+}
+
+static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 file_pos,
+ u64 disk_bytenr, u64 disk_num_bytes,
+ u64 num_bytes, u64 ram_bytes,
+ u8 compression, u8 encryption,
+ u16 other_encoding, int extent_type)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key ins;
+ u64 hint;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ ret = btrfs_drop_extents(trans, root, inode, file_pos,
+ file_pos + num_bytes, file_pos, &hint);
+ BUG_ON(ret);
+
+ ins.objectid = inode->i_ino;
+ ins.offset = file_pos;
+ ins.type = BTRFS_EXTENT_DATA_KEY;
+ ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
+ BUG_ON(ret);
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+ btrfs_set_file_extent_type(leaf, fi, extent_type);
+ btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
+ btrfs_set_file_extent_offset(leaf, fi, 0);
+ btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
+ btrfs_set_file_extent_compression(leaf, fi, compression);
+ btrfs_set_file_extent_encryption(leaf, fi, encryption);
+ btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
+ btrfs_mark_buffer_dirty(leaf);
+
+ inode_add_bytes(inode, num_bytes);
+ btrfs_drop_extent_cache(inode, file_pos, file_pos + num_bytes - 1, 0);
+
+ ins.objectid = disk_bytenr;
+ ins.offset = disk_num_bytes;
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+ ret = btrfs_alloc_reserved_extent(trans, root, leaf->start,
+ root->root_key.objectid,
+ trans->transid, inode->i_ino, &ins);
+ BUG_ON(ret);
+
+ btrfs_free_path(path);
+ return 0;
+}
+
+/* as ordered data IO finishes, this gets called so we can finish
+ * an ordered extent if the range of bytes in the file it covers are
+ * fully written.
+ */
+static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_ordered_extent *ordered_extent;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ int compressed = 0;
+ int ret;
+
+ ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1);
+ if (!ret)
+ return 0;
+
+ trans = btrfs_join_transaction(root, 1);
+
+ ordered_extent = btrfs_lookup_ordered_extent(inode, start);
+ BUG_ON(!ordered_extent);
+ if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags))
+ goto nocow;
+
+ lock_extent(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset + ordered_extent->len - 1,
+ GFP_NOFS);
+
+ if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
+ compressed = 1;
+ if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
+ BUG_ON(compressed);
+ ret = btrfs_mark_extent_written(trans, root, inode,
+ ordered_extent->file_offset,
+ ordered_extent->file_offset +
+ ordered_extent->len);
+ BUG_ON(ret);
+ } else {
+ ret = insert_reserved_file_extent(trans, inode,
+ ordered_extent->file_offset,
+ ordered_extent->start,
+ ordered_extent->disk_len,
+ ordered_extent->len,
+ ordered_extent->len,
+ compressed, 0, 0,
+ BTRFS_FILE_EXTENT_REG);
+ BUG_ON(ret);
+ }
+ unlock_extent(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset + ordered_extent->len - 1,
+ GFP_NOFS);
+nocow:
+ add_pending_csums(trans, inode, ordered_extent->file_offset,
+ &ordered_extent->list);
+
+ mutex_lock(&BTRFS_I(inode)->extent_mutex);
+ btrfs_ordered_update_i_size(inode, ordered_extent);
+ btrfs_update_inode(trans, root, inode);
+ btrfs_remove_ordered_extent(inode, ordered_extent);
+ mutex_unlock(&BTRFS_I(inode)->extent_mutex);
+
+ /* once for us */
+ btrfs_put_ordered_extent(ordered_extent);
+ /* once for the tree */
+ btrfs_put_ordered_extent(ordered_extent);
+
+ btrfs_end_transaction(trans, root);
+ return 0;
+}
+
+int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
+ struct extent_state *state, int uptodate)
+{
+ return btrfs_finish_ordered_io(page->mapping->host, start, end);
+}
+
+/*
+ * When IO fails, either with EIO or csum verification fails, we
+ * try other mirrors that might have a good copy of the data. This
+ * io_failure_record is used to record state as we go through all the
+ * mirrors. If another mirror has good data, the page is set up to date
+ * and things continue. If a good mirror can't be found, the original
+ * bio end_io callback is called to indicate things have failed.
+ */
+struct io_failure_record {
+ struct page *page;
+ u64 start;
+ u64 len;
+ u64 logical;
+ int last_mirror;
+};
+
+int btrfs_io_failed_hook(struct bio *failed_bio,
+ struct page *page, u64 start, u64 end,
+ struct extent_state *state)
+{
+ struct io_failure_record *failrec = NULL;
+ u64 private;
+ struct extent_map *em;
+ struct inode *inode = page->mapping->host;
+ struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct bio *bio;
+ int num_copies;
+ int ret;
+ int rw;
+ u64 logical;
+ unsigned long bio_flags = 0;
+
+ ret = get_state_private(failure_tree, start, &private);
+ if (ret) {
+ failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
+ if (!failrec)
+ return -ENOMEM;
+ failrec->start = start;
+ failrec->len = end - start + 1;
+ failrec->last_mirror = 0;
+
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, failrec->len);
+ if (em->start > start || em->start + em->len < start) {
+ free_extent_map(em);
+ em = NULL;
+ }
+ spin_unlock(&em_tree->lock);
+
+ if (!em || IS_ERR(em)) {
+ kfree(failrec);
+ return -EIO;
+ }
+ logical = start - em->start;
+ logical = em->block_start + logical;
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+ bio_flags = EXTENT_BIO_COMPRESSED;
+ failrec->logical = logical;
+ free_extent_map(em);
+ set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
+ EXTENT_DIRTY, GFP_NOFS);
+ set_state_private(failure_tree, start,
+ (u64)(unsigned long)failrec);
+ } else {
+ failrec = (struct io_failure_record *)(unsigned long)private;
+ }
+ num_copies = btrfs_num_copies(
+ &BTRFS_I(inode)->root->fs_info->mapping_tree,
+ failrec->logical, failrec->len);
+ failrec->last_mirror++;
+ if (!state) {
+ spin_lock_irq(&BTRFS_I(inode)->io_tree.lock);
+ state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
+ failrec->start,
+ EXTENT_LOCKED);
+ if (state && state->start != failrec->start)
+ state = NULL;
+ spin_unlock_irq(&BTRFS_I(inode)->io_tree.lock);
+ }
+ if (!state || failrec->last_mirror > num_copies) {
+ set_state_private(failure_tree, failrec->start, 0);
+ clear_extent_bits(failure_tree, failrec->start,
+ failrec->start + failrec->len - 1,
+ EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
+ kfree(failrec);
+ return -EIO;
+ }
+ bio = bio_alloc(GFP_NOFS, 1);
+ bio->bi_private = state;
+ bio->bi_end_io = failed_bio->bi_end_io;
+ bio->bi_sector = failrec->logical >> 9;
+ bio->bi_bdev = failed_bio->bi_bdev;
+ bio->bi_size = 0;
+ bio_add_page(bio, page, failrec->len, start - page_offset(page));
+ if (failed_bio->bi_rw & (1 << BIO_RW))
+ rw = WRITE;
+ else
+ rw = READ;
+
+ BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
+ failrec->last_mirror,
+ bio_flags);
+ return 0;
+}
+
+/*
+ * each time an IO finishes, we do a fast check in the IO failure tree
+ * to see if we need to process or clean up an io_failure_record
+ */
+int btrfs_clean_io_failures(struct inode *inode, u64 start)
+{
+ u64 private;
+ u64 private_failure;
+ struct io_failure_record *failure;
+ int ret;
+
+ private = 0;
+ if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
+ (u64)-1, 1, EXTENT_DIRTY)) {
+ ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
+ start, &private_failure);
+ if (ret == 0) {
+ failure = (struct io_failure_record *)(unsigned long)
+ private_failure;
+ set_state_private(&BTRFS_I(inode)->io_failure_tree,
+ failure->start, 0);
+ clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
+ failure->start,
+ failure->start + failure->len - 1,
+ EXTENT_DIRTY | EXTENT_LOCKED,
+ GFP_NOFS);
+ kfree(failure);
+ }
+ }
+ return 0;
+}
+
+/*
+ * when reads are done, we need to check csums to verify the data is correct
+ * if there's a match, we allow the bio to finish. If not, we go through
+ * the io_failure_record routines to find good copies
+ */
+int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
+ struct extent_state *state)
+{
+ size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
+ struct inode *inode = page->mapping->host;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ char *kaddr;
+ u64 private = ~(u32)0;
+ int ret;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u32 csum = ~(u32)0;
+ unsigned long flags;
+
+ if (btrfs_test_opt(root, NODATASUM) ||
+ btrfs_test_flag(inode, NODATASUM))
+ return 0;
+ if (state && state->start == start) {
+ private = state->private;
+ ret = 0;
+ } else {
+ ret = get_state_private(io_tree, start, &private);
+ }
+ local_irq_save(flags);
+ kaddr = kmap_atomic(page, KM_IRQ0);
+ if (ret) {
+ goto zeroit;
+ }
+ csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
+ btrfs_csum_final(csum, (char *)&csum);
+ if (csum != private) {
+ goto zeroit;
+ }
+ kunmap_atomic(kaddr, KM_IRQ0);
+ local_irq_restore(flags);
+
+ /* if the io failure tree for this inode is non-empty,
+ * check to see if we've recovered from a failed IO
+ */
+ btrfs_clean_io_failures(inode, start);
+ return 0;
+
+zeroit:
+ printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
+ page->mapping->host->i_ino, (unsigned long long)start, csum,
+ private);
+ memset(kaddr + offset, 1, end - start + 1);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_IRQ0);
+ local_irq_restore(flags);
+ if (private == 0)
+ return 0;
+ return -EIO;
+}
+
+/*
+ * This creates an orphan entry for the given inode in case something goes
+ * wrong in the middle of an unlink/truncate.
+ */
+int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ spin_lock(&root->list_lock);
+
+ /* already on the orphan list, we're good */
+ if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
+ spin_unlock(&root->list_lock);
+ return 0;
+ }
+
+ list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
+
+ spin_unlock(&root->list_lock);
+
+ /*
+ * insert an orphan item to track this unlinked/truncated file
+ */
+ ret = btrfs_insert_orphan_item(trans, root, inode->i_ino);
+
+ return ret;
+}
+
+/*
+ * We have done the truncate/delete so we can go ahead and remove the orphan
+ * item for this particular inode.
+ */
+int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ spin_lock(&root->list_lock);
+
+ if (list_empty(&BTRFS_I(inode)->i_orphan)) {
+ spin_unlock(&root->list_lock);
+ return 0;
+ }
+
+ list_del_init(&BTRFS_I(inode)->i_orphan);
+ if (!trans) {
+ spin_unlock(&root->list_lock);
+ return 0;
+ }
+
+ spin_unlock(&root->list_lock);
+
+ ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
+
+ return ret;
+}
+
+/*
+ * this cleans up any orphans that may be left on the list from the last use
+ * of this root.
+ */
+void btrfs_orphan_cleanup(struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ struct btrfs_key key, found_key;
+ struct btrfs_trans_handle *trans;
+ struct inode *inode;
+ int ret = 0, nr_unlink = 0, nr_truncate = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return;
+ path->reada = -1;
+
+ key.objectid = BTRFS_ORPHAN_OBJECTID;
+ btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
+ key.offset = (u64)-1;
+
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0) {
+ printk(KERN_ERR "Error searching slot for orphan: %d"
+ "\n", ret);
+ break;
+ }
+
+ /*
+ * if ret == 0 means we found what we were searching for, which
+ * is weird, but possible, so only screw with path if we didnt
+ * find the key and see if we have stuff that matches
+ */
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+
+ /* pull out the item */
+ leaf = path->nodes[0];
+ item = btrfs_item_nr(leaf, path->slots[0]);
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ /* make sure the item matches what we want */
+ if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
+ break;
+ if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
+ break;
+
+ /* release the path since we're done with it */
+ btrfs_release_path(root, path);
+
+ /*
+ * this is where we are basically btrfs_lookup, without the
+ * crossing root thing. we store the inode number in the
+ * offset of the orphan item.
+ */
+ inode = btrfs_iget_locked(root->fs_info->sb,
+ found_key.offset, root);
+ if (!inode)
+ break;
+
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+
+ /* have to set the location manually */
+ BTRFS_I(inode)->location.objectid = inode->i_ino;
+ BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->location.offset = 0;
+
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ }
+
+ /*
+ * add this inode to the orphan list so btrfs_orphan_del does
+ * the proper thing when we hit it
+ */
+ spin_lock(&root->list_lock);
+ list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
+ spin_unlock(&root->list_lock);
+
+ /*
+ * if this is a bad inode, means we actually succeeded in
+ * removing the inode, but not the orphan record, which means
+ * we need to manually delete the orphan since iput will just
+ * do a destroy_inode
+ */
+ if (is_bad_inode(inode)) {
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_orphan_del(trans, inode);
+ btrfs_end_transaction(trans, root);
+ iput(inode);
+ continue;
+ }
+
+ /* if we have links, this was a truncate, lets do that */
+ if (inode->i_nlink) {
+ nr_truncate++;
+ btrfs_truncate(inode);
+ } else {
+ nr_unlink++;
+ }
+
+ /* this will do delete_inode and everything for us */
+ iput(inode);
+ }
+
+ if (nr_unlink)
+ printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
+ if (nr_truncate)
+ printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
+
+ btrfs_free_path(path);
+}
+
+/*
+ * read an inode from the btree into the in-memory inode
+ */
+void btrfs_read_locked_inode(struct inode *inode)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_timespec *tspec;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key location;
+ u64 alloc_group_block;
+ u32 rdev;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
+
+ ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
+ if (ret)
+ goto make_bad;
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+
+ inode->i_mode = btrfs_inode_mode(leaf, inode_item);
+ inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
+ inode->i_uid = btrfs_inode_uid(leaf, inode_item);
+ inode->i_gid = btrfs_inode_gid(leaf, inode_item);
+ btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
+
+ tspec = btrfs_inode_atime(inode_item);
+ inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
+ inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
+
+ tspec = btrfs_inode_mtime(inode_item);
+ inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
+ inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
+
+ tspec = btrfs_inode_ctime(inode_item);
+ inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
+ inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
+
+ inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
+ BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
+ inode->i_generation = BTRFS_I(inode)->generation;
+ inode->i_rdev = 0;
+ rdev = btrfs_inode_rdev(leaf, inode_item);
+
+ BTRFS_I(inode)->index_cnt = (u64)-1;
+
+ alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
+ BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
+ alloc_group_block);
+ BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
+ if (!BTRFS_I(inode)->block_group) {
+ BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
+ NULL, 0,
+ BTRFS_BLOCK_GROUP_METADATA, 0);
+ }
+ btrfs_free_path(path);
+ inode_item = NULL;
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ break;
+ case S_IFDIR:
+ inode->i_fop = &btrfs_dir_file_operations;
+ if (root == root->fs_info->tree_root)
+ inode->i_op = &btrfs_dir_ro_inode_operations;
+ else
+ inode->i_op = &btrfs_dir_inode_operations;
+ break;
+ case S_IFLNK:
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ break;
+ default:
+ init_special_inode(inode, inode->i_mode, rdev);
+ break;
+ }
+ return;
+
+make_bad:
+ btrfs_free_path(path);
+ make_bad_inode(inode);
+}
+
+/*
+ * given a leaf and an inode, copy the inode fields into the leaf
+ */
+static void fill_inode_item(struct btrfs_trans_handle *trans,
+ struct extent_buffer *leaf,
+ struct btrfs_inode_item *item,
+ struct inode *inode)
+{
+ btrfs_set_inode_uid(leaf, item, inode->i_uid);
+ btrfs_set_inode_gid(leaf, item, inode->i_gid);
+ btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
+ btrfs_set_inode_mode(leaf, item, inode->i_mode);
+ btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
+
+ btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
+ inode->i_atime.tv_sec);
+ btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
+ inode->i_atime.tv_nsec);
+
+ btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
+ inode->i_mtime.tv_sec);
+ btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
+ inode->i_mtime.tv_nsec);
+
+ btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
+ inode->i_ctime.tv_sec);
+ btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
+ inode->i_ctime.tv_nsec);
+
+ btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
+ btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
+ btrfs_set_inode_transid(leaf, item, trans->transid);
+ btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
+ btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
+ btrfs_set_inode_block_group(leaf, item,
+ BTRFS_I(inode)->block_group->key.objectid);
+}
+
+/*
+ * copy everything in the in-memory inode into the btree.
+ */
+int noinline btrfs_update_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_lookup_inode(trans, root, path,
+ &BTRFS_I(inode)->location, 1);
+ if (ret) {
+ if (ret > 0)
+ ret = -ENOENT;
+ goto failed;
+ }
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+
+ fill_inode_item(trans, leaf, inode_item, inode);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_set_inode_last_trans(trans, inode);
+ ret = 0;
+failed:
+ btrfs_free_path(path);
+ return ret;
+}
+
+
+/*
+ * unlink helper that gets used here in inode.c and in the tree logging
+ * recovery code. It remove a link in a directory with a given name, and
+ * also drops the back refs in the inode to the directory
+ */
+int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir, struct inode *inode,
+ const char *name, int name_len)
+{
+ struct btrfs_path *path;
+ int ret = 0;
+ struct extent_buffer *leaf;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ u64 index;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
+ name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto err;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto err;
+ }
+ leaf = path->nodes[0];
+ btrfs_dir_item_key_to_cpu(leaf, di, &key);
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ if (ret)
+ goto err;
+ btrfs_release_path(root, path);
+
+ ret = btrfs_del_inode_ref(trans, root, name, name_len,
+ inode->i_ino,
+ dir->i_ino, &index);
+ if (ret) {
+ printk("failed to delete reference to %.*s, "
+ "inode %lu parent %lu\n", name_len, name,
+ inode->i_ino, dir->i_ino);
+ goto err;
+ }
+
+ di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
+ index, name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto err;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto err;
+ }
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ btrfs_release_path(root, path);
+
+ ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
+ inode, dir->i_ino);
+ BUG_ON(ret != 0 && ret != -ENOENT);
+ if (ret != -ENOENT)
+ BTRFS_I(dir)->log_dirty_trans = trans->transid;
+
+ ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
+ dir, index);
+ BUG_ON(ret);
+err:
+ btrfs_free_path(path);
+ if (ret)
+ goto out;
+
+ btrfs_i_size_write(dir, dir->i_size - name_len * 2);
+ inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+ btrfs_update_inode(trans, root, dir);
+ btrfs_drop_nlink(inode);
+ ret = btrfs_update_inode(trans, root, inode);
+ dir->i_sb->s_dirt = 1;
+out:
+ return ret;
+}
+
+static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct btrfs_root *root;
+ struct btrfs_trans_handle *trans;
+ struct inode *inode = dentry->d_inode;
+ int ret;
+ unsigned long nr = 0;
+
+ root = BTRFS_I(dir)->root;
+
+ ret = btrfs_check_free_space(root, 1, 1);
+ if (ret)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, dir);
+ ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
+ dentry->d_name.name, dentry->d_name.len);
+
+ if (inode->i_nlink == 0)
+ ret = btrfs_orphan_add(trans, inode);
+
+ nr = trans->blocks_used;
+
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ btrfs_btree_balance_dirty(root, nr);
+ return ret;
+}
+
+static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ int err = 0;
+ int ret;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr = 0;
+
+ /*
+ * the FIRST_FREE_OBJECTID check makes sure we don't try to rmdir
+ * the root of a subvolume or snapshot
+ */
+ if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
+ inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
+ return -ENOTEMPTY;
+ }
+
+ ret = btrfs_check_free_space(root, 1, 1);
+ if (ret)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_orphan_add(trans, inode);
+ if (err)
+ goto fail_trans;
+
+ /* now the directory is empty */
+ err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
+ dentry->d_name.name, dentry->d_name.len);
+ if (!err) {
+ btrfs_i_size_write(inode, 0);
+ }
+
+fail_trans:
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction_throttle(trans, root);
+fail:
+ btrfs_btree_balance_dirty(root, nr);
+
+ if (ret && !err)
+ err = ret;
+ return err;
+}
+
+/*
+ * when truncating bytes in a file, it is possible to avoid reading
+ * the leaves that contain only checksum items. This can be the
+ * majority of the IO required to delete a large file, but it must
+ * be done carefully.
+ *
+ * The keys in the level just above the leaves are checked to make sure
+ * the lowest key in a given leaf is a csum key, and starts at an offset
+ * after the new size.
+ *
+ * Then the key for the next leaf is checked to make sure it also has
+ * a checksum item for the same file. If it does, we know our target leaf
+ * contains only checksum items, and it can be safely freed without reading
+ * it.
+ *
+ * This is just an optimization targeted at large files. It may do
+ * nothing. It will return 0 unless things went badly.
+ */
+static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct inode *inode, u64 new_size)
+{
+ struct btrfs_key key;
+ int ret;
+ int nritems;
+ struct btrfs_key found_key;
+ struct btrfs_key other_key;
+ struct btrfs_leaf_ref *ref;
+ u64 leaf_gen;
+ u64 leaf_start;
+
+ path->lowest_level = 1;
+ key.objectid = inode->i_ino;
+ key.type = BTRFS_CSUM_ITEM_KEY;
+ key.offset = new_size;
+again:
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+
+ if (path->nodes[1] == NULL) {
+ ret = 0;
+ goto out;
+ }
+ ret = 0;
+ btrfs_node_key_to_cpu(path->nodes[1], &found_key, path->slots[1]);
+ nritems = btrfs_header_nritems(path->nodes[1]);
+
+ if (!nritems)
+ goto out;
+
+ if (path->slots[1] >= nritems)
+ goto next_node;
+
+ /* did we find a key greater than anything we want to delete? */
+ if (found_key.objectid > inode->i_ino ||
+ (found_key.objectid == inode->i_ino && found_key.type > key.type))
+ goto out;
+
+ /* we check the next key in the node to make sure the leave contains
+ * only checksum items. This comparison doesn't work if our
+ * leaf is the last one in the node
+ */
+ if (path->slots[1] + 1 >= nritems) {
+next_node:
+ /* search forward from the last key in the node, this
+ * will bring us into the next node in the tree
+ */
+ btrfs_node_key_to_cpu(path->nodes[1], &found_key, nritems - 1);
+
+ /* unlikely, but we inc below, so check to be safe */
+ if (found_key.offset == (u64)-1)
+ goto out;
+
+ /* search_forward needs a path with locks held, do the
+ * search again for the original key. It is possible
+ * this will race with a balance and return a path that
+ * we could modify, but this drop is just an optimization
+ * and is allowed to miss some leaves.
+ */
+ btrfs_release_path(root, path);
+ found_key.offset++;
+
+ /* setup a max key for search_forward */
+ other_key.offset = (u64)-1;
+ other_key.type = key.type;
+ other_key.objectid = key.objectid;
+
+ path->keep_locks = 1;
+ ret = btrfs_search_forward(root, &found_key, &other_key,
+ path, 0, 0);
+ path->keep_locks = 0;
+ if (ret || found_key.objectid != key.objectid ||
+ found_key.type != key.type) {
+ ret = 0;
+ goto out;
+ }
+
+ key.offset = found_key.offset;
+ btrfs_release_path(root, path);
+ cond_resched();
+ goto again;
+ }
+
+ /* we know there's one more slot after us in the tree,
+ * read that key so we can verify it is also a checksum item
+ */
+ btrfs_node_key_to_cpu(path->nodes[1], &other_key, path->slots[1] + 1);
+
+ if (found_key.objectid < inode->i_ino)
+ goto next_key;
+
+ if (found_key.type != key.type || found_key.offset < new_size)
+ goto next_key;
+
+ /*
+ * if the key for the next leaf isn't a csum key from this objectid,
+ * we can't be sure there aren't good items inside this leaf.
+ * Bail out
+ */
+ if (other_key.objectid != inode->i_ino || other_key.type != key.type)
+ goto out;
+
+ leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
+ leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
+ /*
+ * it is safe to delete this leaf, it contains only
+ * csum items from this inode at an offset >= new_size
+ */
+ ret = btrfs_del_leaf(trans, root, path, leaf_start);
+ BUG_ON(ret);
+
+ if (root->ref_cows && leaf_gen < trans->transid) {
+ ref = btrfs_alloc_leaf_ref(root, 0);
+ if (ref) {
+ ref->root_gen = root->root_key.offset;
+ ref->bytenr = leaf_start;
+ ref->owner = 0;
+ ref->generation = leaf_gen;
+ ref->nritems = 0;
+
+ ret = btrfs_add_leaf_ref(root, ref, 0);
+ WARN_ON(ret);
+ btrfs_free_leaf_ref(root, ref);
+ } else {
+ WARN_ON(1);
+ }
+ }
+next_key:
+ btrfs_release_path(root, path);
+
+ if (other_key.objectid == inode->i_ino &&
+ other_key.type == key.type && other_key.offset > key.offset) {
+ key.offset = other_key.offset;
+ cond_resched();
+ goto again;
+ }
+ ret = 0;
+out:
+ /* fixup any changes we've made to the path */
+ path->lowest_level = 0;
+ path->keep_locks = 0;
+ btrfs_release_path(root, path);
+ return ret;
+}
+
+/*
+ * this can truncate away extent items, csum items and directory items.
+ * It starts at a high offset and removes keys until it can't find
+ * any higher than new_size
+ *
+ * csum items that cross the new i_size are truncated to the new size
+ * as well.
+ *
+ * min_type is the minimum key type to truncate down to. If set to 0, this
+ * will kill all the items on this inode, including the INODE_ITEM_KEY.
+ */
+noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode,
+ u64 new_size, u32 min_type)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u32 found_type;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *fi;
+ u64 extent_start = 0;
+ u64 extent_num_bytes = 0;
+ u64 item_end = 0;
+ u64 root_gen = 0;
+ u64 root_owner = 0;
+ int found_extent;
+ int del_item;
+ int pending_del_nr = 0;
+ int pending_del_slot = 0;
+ int extent_type = -1;
+ int encoding;
+ u64 mask = root->sectorsize - 1;
+
+ if (root->ref_cows)
+ btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
+ path = btrfs_alloc_path();
+ path->reada = -1;
+ BUG_ON(!path);
+
+ /* FIXME, add redo link to tree so we don't leak on crash */
+ key.objectid = inode->i_ino;
+ key.offset = (u64)-1;
+ key.type = (u8)-1;
+
+ btrfs_init_path(path);
+
+ ret = drop_csum_leaves(trans, root, path, inode, new_size);
+ BUG_ON(ret);
+
+search_again:
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0) {
+ goto error;
+ }
+ if (ret > 0) {
+ /* there are no items in the tree for us to truncate, we're
+ * done
+ */
+ if (path->slots[0] == 0) {
+ ret = 0;
+ goto error;
+ }
+ path->slots[0]--;
+ }
+
+ while(1) {
+ fi = NULL;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ found_type = btrfs_key_type(&found_key);
+ encoding = 0;
+
+ if (found_key.objectid != inode->i_ino)
+ break;
+
+ if (found_type < min_type)
+ break;
+
+ item_end = found_key.offset;
+ if (found_type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+ encoding = btrfs_file_extent_compression(leaf, fi);
+ encoding |= btrfs_file_extent_encryption(leaf, fi);
+ encoding |= btrfs_file_extent_other_encoding(leaf, fi);
+
+ if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+ item_end +=
+ btrfs_file_extent_num_bytes(leaf, fi);
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ item_end += btrfs_file_extent_inline_len(leaf,
+ fi);
+ }
+ item_end--;
+ }
+ if (found_type == BTRFS_CSUM_ITEM_KEY) {
+ ret = btrfs_csum_truncate(trans, root, path,
+ new_size);
+ BUG_ON(ret);
+ }
+ if (item_end < new_size) {
+ if (found_type == BTRFS_DIR_ITEM_KEY) {
+ found_type = BTRFS_INODE_ITEM_KEY;
+ } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
+ found_type = BTRFS_CSUM_ITEM_KEY;
+ } else if (found_type == BTRFS_EXTENT_DATA_KEY) {
+ found_type = BTRFS_XATTR_ITEM_KEY;
+ } else if (found_type == BTRFS_XATTR_ITEM_KEY) {
+ found_type = BTRFS_INODE_REF_KEY;
+ } else if (found_type) {
+ found_type--;
+ } else {
+ break;
+ }
+ btrfs_set_key_type(&key, found_type);
+ goto next;
+ }
+ if (found_key.offset >= new_size)
+ del_item = 1;
+ else
+ del_item = 0;
+ found_extent = 0;
+
+ /* FIXME, shrink the extent if the ref count is only 1 */
+ if (found_type != BTRFS_EXTENT_DATA_KEY)
+ goto delete;
+
+ if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+ u64 num_dec;
+ extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
+ if (!del_item && !encoding) {
+ u64 orig_num_bytes =
+ btrfs_file_extent_num_bytes(leaf, fi);
+ extent_num_bytes = new_size -
+ found_key.offset + root->sectorsize - 1;
+ extent_num_bytes = extent_num_bytes &
+ ~((u64)root->sectorsize - 1);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_num_bytes);
+ num_dec = (orig_num_bytes -
+ extent_num_bytes);
+ if (root->ref_cows && extent_start != 0)
+ inode_sub_bytes(inode, num_dec);
+ btrfs_mark_buffer_dirty(leaf);
+ } else {
+ extent_num_bytes =
+ btrfs_file_extent_disk_num_bytes(leaf,
+ fi);
+ /* FIXME blocksize != 4096 */
+ num_dec = btrfs_file_extent_num_bytes(leaf, fi);
+ if (extent_start != 0) {
+ found_extent = 1;
+ if (root->ref_cows)
+ inode_sub_bytes(inode, num_dec);
+ }
+ root_gen = btrfs_header_generation(leaf);
+ root_owner = btrfs_header_owner(leaf);
+ }
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ /*
+ * we can't truncate inline items that have had
+ * special encodings
+ */
+ if (!del_item &&
+ btrfs_file_extent_compression(leaf, fi) == 0 &&
+ btrfs_file_extent_encryption(leaf, fi) == 0 &&
+ btrfs_file_extent_other_encoding(leaf, fi) == 0) {
+ u32 size = new_size - found_key.offset;
+
+ if (root->ref_cows) {
+ inode_sub_bytes(inode, item_end + 1 -
+ new_size);
+ }
+ size =
+ btrfs_file_extent_calc_inline_size(size);
+ ret = btrfs_truncate_item(trans, root, path,
+ size, 1);
+ BUG_ON(ret);
+ } else if (root->ref_cows) {
+ inode_sub_bytes(inode, item_end + 1 -
+ found_key.offset);
+ }
+ }
+delete:
+ if (del_item) {
+ if (!pending_del_nr) {
+ /* no pending yet, add ourselves */
+ pending_del_slot = path->slots[0];
+ pending_del_nr = 1;
+ } else if (pending_del_nr &&
+ path->slots[0] + 1 == pending_del_slot) {
+ /* hop on the pending chunk */
+ pending_del_nr++;
+ pending_del_slot = path->slots[0];
+ } else {
+ printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
+ }
+ } else {
+ break;
+ }
+ if (found_extent) {
+ ret = btrfs_free_extent(trans, root, extent_start,
+ extent_num_bytes,
+ leaf->start, root_owner,
+ root_gen, inode->i_ino, 0);
+ BUG_ON(ret);
+ }
+next:
+ if (path->slots[0] == 0) {
+ if (pending_del_nr)
+ goto del_pending;
+ btrfs_release_path(root, path);
+ goto search_again;
+ }
+
+ path->slots[0]--;
+ if (pending_del_nr &&
+ path->slots[0] + 1 != pending_del_slot) {
+ struct btrfs_key debug;
+del_pending:
+ btrfs_item_key_to_cpu(path->nodes[0], &debug,
+ pending_del_slot);
+ ret = btrfs_del_items(trans, root, path,
+ pending_del_slot,
+ pending_del_nr);
+ BUG_ON(ret);
+ pending_del_nr = 0;
+ btrfs_release_path(root, path);
+ goto search_again;
+ }
+ }
+ ret = 0;
+error:
+ if (pending_del_nr) {
+ ret = btrfs_del_items(trans, root, path, pending_del_slot,
+ pending_del_nr);
+ }
+ btrfs_free_path(path);
+ inode->i_sb->s_dirt = 1;
+ return ret;
+}
+
+/*
+ * taken from block_truncate_page, but does cow as it zeros out
+ * any bytes left in the last page in the file.
+ */
+static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
+{
+ struct inode *inode = mapping->host;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_ordered_extent *ordered;
+ char *kaddr;
+ u32 blocksize = root->sectorsize;
+ pgoff_t index = from >> PAGE_CACHE_SHIFT;
+ unsigned offset = from & (PAGE_CACHE_SIZE-1);
+ struct page *page;
+ int ret = 0;
+ u64 page_start;
+ u64 page_end;
+
+ if ((offset & (blocksize - 1)) == 0)
+ goto out;
+
+ ret = -ENOMEM;
+again:
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ goto out;
+
+ page_start = page_offset(page);
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ if (!PageUptodate(page)) {
+ ret = btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (page->mapping != mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto again;
+ }
+ if (!PageUptodate(page)) {
+ ret = -EIO;
+ goto out_unlock;
+ }
+ }
+ wait_on_page_writeback(page);
+
+ lock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ set_page_extent_mapped(page);
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+ ret = 0;
+ if (offset != PAGE_CACHE_SIZE) {
+ kaddr = kmap(page);
+ memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+ flush_dcache_page(page);
+ kunmap(page);
+ }
+ ClearPageChecked(page);
+ set_page_dirty(page);
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+
+out_unlock:
+ unlock_page(page);
+ page_cache_release(page);
+out:
+ return ret;
+}
+
+int btrfs_cont_expand(struct inode *inode, loff_t size)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct extent_map *em;
+ u64 mask = root->sectorsize - 1;
+ u64 hole_start = (inode->i_size + mask) & ~mask;
+ u64 block_end = (size + mask) & ~mask;
+ u64 last_byte;
+ u64 cur_offset;
+ u64 hole_size;
+ int err;
+
+ if (size <= hole_start)
+ return 0;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ return err;
+
+ btrfs_truncate_page(inode->i_mapping, inode->i_size);
+
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+ btrfs_wait_ordered_range(inode, hole_start,
+ block_end - hole_start);
+ lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
+ ordered = btrfs_lookup_ordered_extent(inode, hole_start);
+ if (!ordered)
+ break;
+ unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
+ btrfs_put_ordered_extent(ordered);
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ cur_offset = hole_start;
+ while (1) {
+ em = btrfs_get_extent(inode, NULL, 0, cur_offset,
+ block_end - cur_offset, 0);
+ BUG_ON(IS_ERR(em) || !em);
+ last_byte = min(extent_map_end(em), block_end);
+ last_byte = (last_byte + mask) & ~mask;
+ if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ u64 hint_byte = 0;
+ hole_size = last_byte - cur_offset;
+ err = btrfs_drop_extents(trans, root, inode,
+ cur_offset,
+ cur_offset + hole_size,
+ cur_offset, &hint_byte);
+ if (err)
+ break;
+ err = btrfs_insert_file_extent(trans, root,
+ inode->i_ino, cur_offset, 0,
+ 0, hole_size, 0, hole_size,
+ 0, 0, 0);
+ btrfs_drop_extent_cache(inode, hole_start,
+ last_byte - 1, 0);
+ }
+ free_extent_map(em);
+ cur_offset = last_byte;
+ if (err || cur_offset >= block_end)
+ break;
+ }
+
+ btrfs_end_transaction(trans, root);
+ unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
+ return err;
+}
+
+static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ int err;
+
+ err = inode_change_ok(inode, attr);
+ if (err)
+ return err;
+
+ if (S_ISREG(inode->i_mode) &&
+ attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
+ err = btrfs_cont_expand(inode, attr->ia_size);
+ if (err)
+ return err;
+ }
+
+ err = inode_setattr(inode, attr);
+
+ if (!err && ((attr->ia_valid & ATTR_MODE)))
+ err = btrfs_acl_chmod(inode);
+ return err;
+}
+
+void btrfs_delete_inode(struct inode *inode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ unsigned long nr;
+ int ret;
+
+ truncate_inode_pages(&inode->i_data, 0);
+ if (is_bad_inode(inode)) {
+ btrfs_orphan_del(NULL, inode);
+ goto no_delete;
+ }
+ btrfs_wait_ordered_range(inode, 0, (u64)-1);
+
+ btrfs_i_size_write(inode, 0);
+ trans = btrfs_start_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, inode);
+ ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, 0);
+ if (ret) {
+ btrfs_orphan_del(NULL, inode);
+ goto no_delete_lock;
+ }
+
+ btrfs_orphan_del(trans, inode);
+
+ nr = trans->blocks_used;
+ clear_inode(inode);
+
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root, nr);
+ return;
+
+no_delete_lock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root, nr);
+no_delete:
+ clear_inode(inode);
+}
+
+/*
+ * this returns the key found in the dir entry in the location pointer.
+ * If no dir entries were found, location->objectid is 0.
+ */
+static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
+ struct btrfs_key *location)
+{
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int ret = 0;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
+ namelen, 0);
+ if (IS_ERR(di))
+ ret = PTR_ERR(di);
+ if (!di || IS_ERR(di)) {
+ goto out_err;
+ }
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
+out:
+ btrfs_free_path(path);
+ return ret;
+out_err:
+ location->objectid = 0;
+ goto out;
+}
+
+/*
+ * when we hit a tree root in a directory, the btrfs part of the inode
+ * needs to be changed to reflect the root directory of the tree root. This
+ * is kind of like crossing a mount point.
+ */
+static int fixup_tree_root_location(struct btrfs_root *root,
+ struct btrfs_key *location,
+ struct btrfs_root **sub_root,
+ struct dentry *dentry)
+{
+ struct btrfs_root_item *ri;
+
+ if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
+ return 0;
+ if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
+ return 0;
+
+ *sub_root = btrfs_read_fs_root(root->fs_info, location,
+ dentry->d_name.name,
+ dentry->d_name.len);
+ if (IS_ERR(*sub_root))
+ return PTR_ERR(*sub_root);
+
+ ri = &(*sub_root)->root_item;
+ location->objectid = btrfs_root_dirid(ri);
+ btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+ location->offset = 0;
+
+ return 0;
+}
+
+static noinline void init_btrfs_i(struct inode *inode)
+{
+ struct btrfs_inode *bi = BTRFS_I(inode);
+
+ bi->i_acl = NULL;
+ bi->i_default_acl = NULL;
+
+ bi->generation = 0;
+ bi->last_trans = 0;
+ bi->logged_trans = 0;
+ bi->delalloc_bytes = 0;
+ bi->disk_i_size = 0;
+ bi->flags = 0;
+ bi->index_cnt = (u64)-1;
+ bi->log_dirty_trans = 0;
+ extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
+ extent_io_tree_init(&BTRFS_I(inode)->io_tree,
+ inode->i_mapping, GFP_NOFS);
+ extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
+ inode->i_mapping, GFP_NOFS);
+ INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes);
+ btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
+ mutex_init(&BTRFS_I(inode)->csum_mutex);
+ mutex_init(&BTRFS_I(inode)->extent_mutex);
+ mutex_init(&BTRFS_I(inode)->log_mutex);
+}
+
+static int btrfs_init_locked_inode(struct inode *inode, void *p)
+{
+ struct btrfs_iget_args *args = p;
+ inode->i_ino = args->ino;
+ init_btrfs_i(inode);
+ BTRFS_I(inode)->root = args->root;
+ return 0;
+}
+
+static int btrfs_find_actor(struct inode *inode, void *opaque)
+{
+ struct btrfs_iget_args *args = opaque;
+ return (args->ino == inode->i_ino &&
+ args->root == BTRFS_I(inode)->root);
+}
+
+struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
+ struct btrfs_root *root, int wait)
+{
+ struct inode *inode;
+ struct btrfs_iget_args args;
+ args.ino = objectid;
+ args.root = root;
+
+ if (wait) {
+ inode = ilookup5(s, objectid, btrfs_find_actor,
+ (void *)&args);
+ } else {
+ inode = ilookup5_nowait(s, objectid, btrfs_find_actor,
+ (void *)&args);
+ }
+ return inode;
+}
+
+struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
+ struct btrfs_root *root)
+{
+ struct inode *inode;
+ struct btrfs_iget_args args;
+ args.ino = objectid;
+ args.root = root;
+
+ inode = iget5_locked(s, objectid, btrfs_find_actor,
+ btrfs_init_locked_inode,
+ (void *)&args);
+ return inode;
+}
+
+/* Get an inode object given its location and corresponding root.
+ * Returns in *is_new if the inode was read from disk
+ */
+struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
+ struct btrfs_root *root, int *is_new)
+{
+ struct inode *inode;
+
+ inode = btrfs_iget_locked(s, location->objectid, root);
+ if (!inode)
+ return ERR_PTR(-EACCES);
+
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+ memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ if (is_new)
+ *is_new = 1;
+ } else {
+ if (is_new)
+ *is_new = 0;
+ }
+
+ return inode;
+}
+
+struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
+{
+ struct inode * inode;
+ struct btrfs_inode *bi = BTRFS_I(dir);
+ struct btrfs_root *root = bi->root;
+ struct btrfs_root *sub_root = root;
+ struct btrfs_key location;
+ int ret, new;
+
+ if (dentry->d_name.len > BTRFS_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ ret = btrfs_inode_by_name(dir, dentry, &location);
+
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ inode = NULL;
+ if (location.objectid) {
+ ret = fixup_tree_root_location(root, &location, &sub_root,
+ dentry);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return ERR_PTR(-ENOENT);
+ inode = btrfs_iget(dir->i_sb, &location, sub_root, &new);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ }
+ return inode;
+}
+
+static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct inode *inode;
+
+ if (dentry->d_name.len > BTRFS_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ inode = btrfs_lookup_dentry(dir, dentry);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+
+ return d_splice_alias(inode, dentry);
+}
+
+static unsigned char btrfs_filetype_table[] = {
+ DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static int btrfs_real_readdir(struct file *filp, void *dirent,
+ filldir_t filldir)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_item *item;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+ int ret;
+ u32 nritems;
+ struct extent_buffer *leaf;
+ int slot;
+ int advance;
+ unsigned char d_type;
+ int over = 0;
+ u32 di_cur;
+ u32 di_total;
+ u32 di_len;
+ int key_type = BTRFS_DIR_INDEX_KEY;
+ char tmp_name[32];
+ char *name_ptr;
+ int name_len;
+
+ /* FIXME, use a real flag for deciding about the key type */
+ if (root->fs_info->tree_root == root)
+ key_type = BTRFS_DIR_ITEM_KEY;
+
+ /* special case for "." */
+ if (filp->f_pos == 0) {
+ over = filldir(dirent, ".", 1,
+ 1, inode->i_ino,
+ DT_DIR);
+ if (over)
+ return 0;
+ filp->f_pos = 1;
+ }
+ /* special case for .., just use the back ref */
+ if (filp->f_pos == 1) {
+ u64 pino = parent_ino(filp->f_path.dentry);
+ over = filldir(dirent, "..", 2,
+ 2, pino, DT_DIR);
+ if (over)
+ return 0;
+ filp->f_pos = 2;
+ }
+ path = btrfs_alloc_path();
+ path->reada = 2;
+
+ btrfs_set_key_type(&key, key_type);
+ key.offset = filp->f_pos;
+ key.objectid = inode->i_ino;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+ advance = 0;
+
+ while (1) {
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+ if (advance || slot >= nritems) {
+ if (slot >= nritems - 1) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ break;
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+ } else {
+ slot++;
+ path->slots[0]++;
+ }
+ }
+
+ advance = 1;
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ if (found_key.objectid != key.objectid)
+ break;
+ if (btrfs_key_type(&found_key) != key_type)
+ break;
+ if (found_key.offset < filp->f_pos)
+ continue;
+
+ filp->f_pos = found_key.offset;
+
+ di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+ di_cur = 0;
+ di_total = btrfs_item_size(leaf, item);
+
+ while (di_cur < di_total) {
+ struct btrfs_key location;
+
+ name_len = btrfs_dir_name_len(leaf, di);
+ if (name_len <= sizeof(tmp_name)) {
+ name_ptr = tmp_name;
+ } else {
+ name_ptr = kmalloc(name_len, GFP_NOFS);
+ if (!name_ptr) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ }
+ read_extent_buffer(leaf, name_ptr,
+ (unsigned long)(di + 1), name_len);
+
+ d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
+ btrfs_dir_item_key_to_cpu(leaf, di, &location);
+
+ /* is this a reference to our own snapshot? If so
+ * skip it
+ */
+ if (location.type == BTRFS_ROOT_ITEM_KEY &&
+ location.objectid == root->root_key.objectid) {
+ over = 0;
+ goto skip;
+ }
+ over = filldir(dirent, name_ptr, name_len,
+ found_key.offset, location.objectid,
+ d_type);
+
+skip:
+ if (name_ptr != tmp_name)
+ kfree(name_ptr);
+
+ if (over)
+ goto nopos;
+ di_len = btrfs_dir_name_len(leaf, di) +
+ btrfs_dir_data_len(leaf, di) + sizeof(*di);
+ di_cur += di_len;
+ di = (struct btrfs_dir_item *)((char *)di + di_len);
+ }
+ }
+
+ /* Reached end of directory/root. Bump pos past the last item. */
+ if (key_type == BTRFS_DIR_INDEX_KEY)
+ filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
+ else
+ filp->f_pos++;
+nopos:
+ ret = 0;
+err:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_write_inode(struct inode *inode, int wait)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+
+ if (root->fs_info->btree_inode == inode)
+ return 0;
+
+ if (wait) {
+ trans = btrfs_join_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ ret = btrfs_commit_transaction(trans, root);
+ }
+ return ret;
+}
+
+/*
+ * This is somewhat expensive, updating the tree every time the
+ * inode changes. But, it is most likely to find the inode in cache.
+ * FIXME, needs more benchmarking...there are no reasons other than performance
+ * to keep or drop this code.
+ */
+void btrfs_dirty_inode(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+
+ trans = btrfs_join_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ btrfs_update_inode(trans, root, inode);
+ btrfs_end_transaction(trans, root);
+}
+
+/*
+ * find the highest existing sequence number in a directory
+ * and then set the in-memory index_cnt variable to reflect
+ * free sequence numbers
+ */
+static int btrfs_set_inode_index_count(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key key, found_key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int ret;
+
+ key.objectid = inode->i_ino;
+ btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
+ key.offset = (u64)-1;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ /* FIXME: we should be able to handle this */
+ if (ret == 0)
+ goto out;
+ ret = 0;
+
+ /*
+ * MAGIC NUMBER EXPLANATION:
+ * since we search a directory based on f_pos we have to start at 2
+ * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
+ * else has to start at 2
+ */
+ if (path->slots[0] == 0) {
+ BTRFS_I(inode)->index_cnt = 2;
+ goto out;
+ }
+
+ path->slots[0]--;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid != inode->i_ino ||
+ btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
+ BTRFS_I(inode)->index_cnt = 2;
+ goto out;
+ }
+
+ BTRFS_I(inode)->index_cnt = found_key.offset + 1;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * helper to find a free sequence number in a given directory. This current
+ * code is very simple, later versions will do smarter things in the btree
+ */
+int btrfs_set_inode_index(struct inode *dir, u64 *index)
+{
+ int ret = 0;
+
+ if (BTRFS_I(dir)->index_cnt == (u64)-1) {
+ ret = btrfs_set_inode_index_count(dir);
+ if (ret) {
+ return ret;
+ }
+ }
+
+ *index = BTRFS_I(dir)->index_cnt;
+ BTRFS_I(dir)->index_cnt++;
+
+ return ret;
+}
+
+static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir,
+ const char *name, int name_len,
+ u64 ref_objectid,
+ u64 objectid,
+ struct btrfs_block_group_cache *group,
+ int mode, u64 *index)
+{
+ struct inode *inode;
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_block_group_cache *new_inode_group;
+ struct btrfs_key *location;
+ struct btrfs_path *path;
+ struct btrfs_inode_ref *ref;
+ struct btrfs_key key[2];
+ u32 sizes[2];
+ unsigned long ptr;
+ int ret;
+ int owner;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ inode = new_inode(root->fs_info->sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ if (dir) {
+ ret = btrfs_set_inode_index(dir, index);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+ /*
+ * index_cnt is ignored for everything but a dir,
+ * btrfs_get_inode_index_count has an explanation for the magic
+ * number
+ */
+ init_btrfs_i(inode);
+ BTRFS_I(inode)->index_cnt = 2;
+ BTRFS_I(inode)->root = root;
+ BTRFS_I(inode)->generation = trans->transid;
+
+ if (mode & S_IFDIR)
+ owner = 0;
+ else
+ owner = 1;
+ new_inode_group = btrfs_find_block_group(root, group, 0,
+ BTRFS_BLOCK_GROUP_METADATA, owner);
+ if (!new_inode_group) {
+ printk("find_block group failed\n");
+ new_inode_group = group;
+ }
+ BTRFS_I(inode)->block_group = new_inode_group;
+
+ key[0].objectid = objectid;
+ btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
+ key[0].offset = 0;
+
+ key[1].objectid = objectid;
+ btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
+ key[1].offset = ref_objectid;
+
+ sizes[0] = sizeof(struct btrfs_inode_item);
+ sizes[1] = name_len + sizeof(*ref);
+
+ ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
+ if (ret != 0)
+ goto fail;
+
+ if (objectid > root->highest_inode)
+ root->highest_inode = objectid;
+
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_mode = mode;
+ inode->i_ino = objectid;
+ inode_set_bytes(inode, 0);
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+ inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ fill_inode_item(trans, path->nodes[0], inode_item, inode);
+
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
+ struct btrfs_inode_ref);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
+ ptr = (unsigned long)(ref + 1);
+ write_extent_buffer(path->nodes[0], name, ptr, name_len);
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_free_path(path);
+
+ location = &BTRFS_I(inode)->location;
+ location->objectid = objectid;
+ location->offset = 0;
+ btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+
+ insert_inode_hash(inode);
+ return inode;
+fail:
+ if (dir)
+ BTRFS_I(dir)->index_cnt--;
+ btrfs_free_path(path);
+ return ERR_PTR(ret);
+}
+
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+ return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
+}
+
+/*
+ * utility function to add 'inode' into 'parent_inode' with
+ * a give name and a given sequence number.
+ * if 'add_backref' is true, also insert a backref from the
+ * inode to the parent directory.
+ */
+int btrfs_add_link(struct btrfs_trans_handle *trans,
+ struct inode *parent_inode, struct inode *inode,
+ const char *name, int name_len, int add_backref, u64 index)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_root *root = BTRFS_I(parent_inode)->root;
+
+ key.objectid = inode->i_ino;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.offset = 0;
+
+ ret = btrfs_insert_dir_item(trans, root, name, name_len,
+ parent_inode->i_ino,
+ &key, btrfs_inode_type(inode),
+ index);
+ if (ret == 0) {
+ if (add_backref) {
+ ret = btrfs_insert_inode_ref(trans, root,
+ name, name_len,
+ inode->i_ino,
+ parent_inode->i_ino,
+ index);
+ }
+ btrfs_i_size_write(parent_inode, parent_inode->i_size +
+ name_len * 2);
+ parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_update_inode(trans, root, parent_inode);
+ }
+ return ret;
+}
+
+static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
+ struct dentry *dentry, struct inode *inode,
+ int backref, u64 index)
+{
+ int err = btrfs_add_link(trans, dentry->d_parent->d_inode,
+ inode, dentry->d_name.name,
+ dentry->d_name.len, backref, index);
+ if (!err) {
+ d_instantiate(dentry, inode);
+ return 0;
+ }
+ if (err > 0)
+ err = -EEXIST;
+ return err;
+}
+
+static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
+ int mode, dev_t rdev)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+ unsigned long nr = 0;
+ u64 index = 0;
+
+ if (!new_valid_dev(rdev))
+ return -EINVAL;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino, objectid,
+ BTRFS_I(dir)->block_group, mode, &index);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode, 0, index);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_op = &btrfs_special_inode_operations;
+ init_special_inode(inode, inode->i_mode, rdev);
+ btrfs_update_inode(trans, root, inode);
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+out_unlock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int btrfs_create(struct inode *dir, struct dentry *dentry,
+ int mode, struct nameidata *nd)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ unsigned long nr = 0;
+ u64 objectid;
+ u64 index = 0;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto fail;
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino,
+ objectid, BTRFS_I(dir)->block_group, mode,
+ &index);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode, 0, index);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+out_unlock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = old_dentry->d_inode;
+ u64 index;
+ unsigned long nr = 0;
+ int err;
+ int drop_inode = 0;
+
+ if (inode->i_nlink == 0)
+ return -ENOENT;
+
+ btrfs_inc_nlink(inode);
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto fail;
+ err = btrfs_set_inode_index(dir, &index);
+ if (err)
+ goto fail;
+
+ trans = btrfs_start_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, dir);
+ atomic_inc(&inode->i_count);
+
+ err = btrfs_add_nondir(trans, dentry, inode, 1, index);
+
+ if (err)
+ drop_inode = 1;
+
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, dir);
+ err = btrfs_update_inode(trans, root, inode);
+
+ if (err)
+ drop_inode = 1;
+
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ struct inode *inode = NULL;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int err = 0;
+ int drop_on_err = 0;
+ u64 objectid = 0;
+ u64 index = 0;
+ unsigned long nr = 1;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto out_unlock;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ if (IS_ERR(trans)) {
+ err = PTR_ERR(trans);
+ goto out_unlock;
+ }
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino, objectid,
+ BTRFS_I(dir)->block_group, S_IFDIR | mode,
+ &index);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_fail;
+ }
+
+ drop_on_err = 1;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err)
+ goto out_fail;
+
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+ btrfs_set_trans_block_group(trans, inode);
+
+ btrfs_i_size_write(inode, 0);
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ goto out_fail;
+
+ err = btrfs_add_link(trans, dentry->d_parent->d_inode,
+ inode, dentry->d_name.name,
+ dentry->d_name.len, 0, index);
+ if (err)
+ goto out_fail;
+
+ d_instantiate(dentry, inode);
+ drop_on_err = 0;
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+
+out_fail:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+
+out_unlock:
+ if (drop_on_err)
+ iput(inode);
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+/* helper for btfs_get_extent. Given an existing extent in the tree,
+ * and an extent that you want to insert, deal with overlap and insert
+ * the new extent into the tree.
+ */
+static int merge_extent_mapping(struct extent_map_tree *em_tree,
+ struct extent_map *existing,
+ struct extent_map *em,
+ u64 map_start, u64 map_len)
+{
+ u64 start_diff;
+
+ BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
+ start_diff = map_start - em->start;
+ em->start = map_start;
+ em->len = map_len;
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+ em->block_start += start_diff;
+ em->block_len -= start_diff;
+ }
+ return add_extent_mapping(em_tree, em);
+}
+
+static noinline int uncompress_inline(struct btrfs_path *path,
+ struct inode *inode, struct page *page,
+ size_t pg_offset, u64 extent_offset,
+ struct btrfs_file_extent_item *item)
+{
+ int ret;
+ struct extent_buffer *leaf = path->nodes[0];
+ char *tmp;
+ size_t max_size;
+ unsigned long inline_size;
+ unsigned long ptr;
+
+ WARN_ON(pg_offset != 0);
+ max_size = btrfs_file_extent_ram_bytes(leaf, item);
+ inline_size = btrfs_file_extent_inline_item_len(leaf,
+ btrfs_item_nr(leaf, path->slots[0]));
+ tmp = kmalloc(inline_size, GFP_NOFS);
+ ptr = btrfs_file_extent_inline_start(item);
+
+ read_extent_buffer(leaf, tmp, ptr, inline_size);
+
+ max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
+ ret = btrfs_zlib_decompress(tmp, page, extent_offset,
+ inline_size, max_size);
+ if (ret) {
+ char *kaddr = kmap_atomic(page, KM_USER0);
+ unsigned long copy_size = min_t(u64,
+ PAGE_CACHE_SIZE - pg_offset,
+ max_size - extent_offset);
+ memset(kaddr + pg_offset, 0, copy_size);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+ kfree(tmp);
+ return 0;
+}
+
+/*
+ * a bit scary, this does extent mapping from logical file offset to the disk.
+ * the ugly parts come from merging extents from the disk with the
+ * in-ram representation. This gets more complex because of the data=ordered code,
+ * where the in-ram extents might be locked pending data=ordered completion.
+ *
+ * This also copies inline extents directly into the page.
+ */
+struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
+ size_t pg_offset, u64 start, u64 len,
+ int create)
+{
+ int ret;
+ int err = 0;
+ u64 bytenr;
+ u64 extent_start = 0;
+ u64 extent_end = 0;
+ u64 objectid = inode->i_ino;
+ u32 found_type;
+ struct btrfs_path *path = NULL;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *item;
+ struct extent_buffer *leaf;
+ struct btrfs_key found_key;
+ struct extent_map *em = NULL;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_trans_handle *trans = NULL;
+ int compressed;
+
+again:
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (em)
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ spin_unlock(&em_tree->lock);
+
+ if (em) {
+ if (em->start > start || em->start + em->len <= start)
+ free_extent_map(em);
+ else if (em->block_start == EXTENT_MAP_INLINE && page)
+ free_extent_map(em);
+ else
+ goto out;
+ }
+ em = alloc_extent_map(GFP_NOFS);
+ if (!em) {
+ err = -ENOMEM;
+ goto out;
+ }
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ em->start = EXTENT_MAP_HOLE;
+ em->orig_start = EXTENT_MAP_HOLE;
+ em->len = (u64)-1;
+ em->block_len = (u64)-1;
+
+ if (!path) {
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ }
+
+ ret = btrfs_lookup_file_extent(trans, root, path,
+ objectid, start, trans != NULL);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+
+ if (ret != 0) {
+ if (path->slots[0] == 0)
+ goto not_found;
+ path->slots[0]--;
+ }
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ /* are we inside the extent that was found? */
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ found_type = btrfs_key_type(&found_key);
+ if (found_key.objectid != objectid ||
+ found_type != BTRFS_EXTENT_DATA_KEY) {
+ goto not_found;
+ }
+
+ found_type = btrfs_file_extent_type(leaf, item);
+ extent_start = found_key.offset;
+ compressed = btrfs_file_extent_compression(leaf, item);
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ extent_end = extent_start +
+ btrfs_file_extent_num_bytes(leaf, item);
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ size_t size;
+ size = btrfs_file_extent_inline_len(leaf, item);
+ extent_end = (extent_start + size + root->sectorsize - 1) &
+ ~((u64)root->sectorsize - 1);
+ }
+
+ if (start >= extent_end) {
+ path->slots[0]++;
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ if (ret > 0)
+ goto not_found;
+ leaf = path->nodes[0];
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != objectid ||
+ found_key.type != BTRFS_EXTENT_DATA_KEY)
+ goto not_found;
+ if (start + len <= found_key.offset)
+ goto not_found;
+ em->start = start;
+ em->len = found_key.offset - start;
+ goto not_found_em;
+ }
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ em->start = extent_start;
+ em->len = extent_end - extent_start;
+ em->orig_start = extent_start -
+ btrfs_file_extent_offset(leaf, item);
+ bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
+ if (bytenr == 0) {
+ em->block_start = EXTENT_MAP_HOLE;
+ goto insert;
+ }
+ if (compressed) {
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ em->block_start = bytenr;
+ em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
+ item);
+ } else {
+ bytenr += btrfs_file_extent_offset(leaf, item);
+ em->block_start = bytenr;
+ em->block_len = em->len;
+ if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
+ set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
+ }
+ goto insert;
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ unsigned long ptr;
+ char *map;
+ size_t size;
+ size_t extent_offset;
+ size_t copy_size;
+
+ em->block_start = EXTENT_MAP_INLINE;
+ if (!page || create) {
+ em->start = extent_start;
+ em->len = extent_end - extent_start;
+ goto out;
+ }
+
+ size = btrfs_file_extent_inline_len(leaf, item);
+ extent_offset = page_offset(page) + pg_offset - extent_start;
+ copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
+ size - extent_offset);
+ em->start = extent_start + extent_offset;
+ em->len = (copy_size + root->sectorsize - 1) &
+ ~((u64)root->sectorsize - 1);
+ em->orig_start = EXTENT_MAP_INLINE;
+ if (compressed)
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ ptr = btrfs_file_extent_inline_start(item) + extent_offset;
+ if (create == 0 && !PageUptodate(page)) {
+ if (btrfs_file_extent_compression(leaf, item) ==
+ BTRFS_COMPRESS_ZLIB) {
+ ret = uncompress_inline(path, inode, page,
+ pg_offset,
+ extent_offset, item);
+ BUG_ON(ret);
+ } else {
+ map = kmap(page);
+ read_extent_buffer(leaf, map + pg_offset, ptr,
+ copy_size);
+ kunmap(page);
+ }
+ flush_dcache_page(page);
+ } else if (create && PageUptodate(page)) {
+ if (!trans) {
+ kunmap(page);
+ free_extent_map(em);
+ em = NULL;
+ btrfs_release_path(root, path);
+ trans = btrfs_join_transaction(root, 1);
+ goto again;
+ }
+ map = kmap(page);
+ write_extent_buffer(leaf, map + pg_offset, ptr,
+ copy_size);
+ kunmap(page);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ set_extent_uptodate(io_tree, em->start,
+ extent_map_end(em) - 1, GFP_NOFS);
+ goto insert;
+ } else {
+ printk("unkknown found_type %d\n", found_type);
+ WARN_ON(1);
+ }
+not_found:
+ em->start = start;
+ em->len = len;
+not_found_em:
+ em->block_start = EXTENT_MAP_HOLE;
+ set_bit(EXTENT_FLAG_VACANCY, &em->flags);
+insert:
+ btrfs_release_path(root, path);
+ if (em->start > start || extent_map_end(em) <= start) {
+ printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
+ err = -EIO;
+ goto out;
+ }
+
+ err = 0;
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ /* it is possible that someone inserted the extent into the tree
+ * while we had the lock dropped. It is also possible that
+ * an overlapping map exists in the tree
+ */
+ if (ret == -EEXIST) {
+ struct extent_map *existing;
+
+ ret = 0;
+
+ existing = lookup_extent_mapping(em_tree, start, len);
+ if (existing && (existing->start > start ||
+ existing->start + existing->len <= start)) {
+ free_extent_map(existing);
+ existing = NULL;
+ }
+ if (!existing) {
+ existing = lookup_extent_mapping(em_tree, em->start,
+ em->len);
+ if (existing) {
+ err = merge_extent_mapping(em_tree, existing,
+ em, start,
+ root->sectorsize);
+ free_extent_map(existing);
+ if (err) {
+ free_extent_map(em);
+ em = NULL;
+ }
+ } else {
+ err = -EIO;
+ printk("failing to insert %Lu %Lu\n",
+ start, len);
+ free_extent_map(em);
+ em = NULL;
+ }
+ } else {
+ free_extent_map(em);
+ em = existing;
+ err = 0;
+ }
+ }
+ spin_unlock(&em_tree->lock);
+out:
+ if (path)
+ btrfs_free_path(path);
+ if (trans) {
+ ret = btrfs_end_transaction(trans, root);
+ if (!err) {
+ err = ret;
+ }
+ }
+ if (err) {
+ free_extent_map(em);
+ WARN_ON(1);
+ return ERR_PTR(err);
+ }
+ return em;
+}
+
+static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
+ const struct iovec *iov, loff_t offset,
+ unsigned long nr_segs)
+{
+ return -EINVAL;
+}
+
+static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
+{
+ return extent_bmap(mapping, iblock, btrfs_get_extent);
+}
+
+int btrfs_readpage(struct file *file, struct page *page)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ return extent_read_full_page(tree, page, btrfs_get_extent);
+}
+
+static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+
+
+ if (current->flags & PF_MEMALLOC) {
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 0;
+ }
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
+}
+
+int btrfs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
+}
+
+static int
+btrfs_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ return extent_readpages(tree, mapping, pages, nr_pages,
+ btrfs_get_extent);
+}
+static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ struct extent_io_tree *tree;
+ struct extent_map_tree *map;
+ int ret;
+
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ map = &BTRFS_I(page->mapping->host)->extent_tree;
+ ret = try_release_extent_mapping(map, tree, page, gfp_flags);
+ if (ret == 1) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+ return ret;
+}
+
+static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ if (PageWriteback(page) || PageDirty(page))
+ return 0;
+ return __btrfs_releasepage(page, gfp_flags);
+}
+
+static void btrfs_invalidatepage(struct page *page, unsigned long offset)
+{
+ struct extent_io_tree *tree;
+ struct btrfs_ordered_extent *ordered;
+ u64 page_start = page_offset(page);
+ u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ wait_on_page_writeback(page);
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ if (offset) {
+ btrfs_releasepage(page, GFP_NOFS);
+ return;
+ }
+
+ lock_extent(tree, page_start, page_end, GFP_NOFS);
+ ordered = btrfs_lookup_ordered_extent(page->mapping->host,
+ page_offset(page));
+ if (ordered) {
+ /*
+ * IO on this page will never be started, so we need
+ * to account for any ordered extents now
+ */
+ clear_extent_bit(tree, page_start, page_end,
+ EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_LOCKED, 1, 0, GFP_NOFS);
+ btrfs_finish_ordered_io(page->mapping->host,
+ page_start, page_end);
+ btrfs_put_ordered_extent(ordered);
+ lock_extent(tree, page_start, page_end, GFP_NOFS);
+ }
+ clear_extent_bit(tree, page_start, page_end,
+ EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_ORDERED,
+ 1, 1, GFP_NOFS);
+ __btrfs_releasepage(page, GFP_NOFS);
+
+ ClearPageChecked(page);
+ if (PagePrivate(page)) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+}
+
+/*
+ * btrfs_page_mkwrite() is not allowed to change the file size as it gets
+ * called from a page fault handler when a page is first dirtied. Hence we must
+ * be careful to check for EOF conditions here. We set the page up correctly
+ * for a written page which means we get ENOSPC checking when writing into
+ * holes and correct delalloc and unwritten extent mapping on filesystems that
+ * support these features.
+ *
+ * We are not allowed to take the i_mutex here so we have to play games to
+ * protect against truncate races as the page could now be beyond EOF. Because
+ * vmtruncate() writes the inode size before removing pages, once we have the
+ * page lock we can determine safely if the page is beyond EOF. If it is not
+ * beyond EOF, then the page is guaranteed safe against truncation until we
+ * unlock the page.
+ */
+int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+ struct inode *inode = fdentry(vma->vm_file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_ordered_extent *ordered;
+ char *kaddr;
+ unsigned long zero_start;
+ loff_t size;
+ int ret;
+ u64 page_start;
+ u64 page_end;
+
+ ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
+ if (ret)
+ goto out;
+
+ ret = -EINVAL;
+again:
+ lock_page(page);
+ size = i_size_read(inode);
+ page_start = page_offset(page);
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ if ((page->mapping != inode->i_mapping) ||
+ (page_start >= size)) {
+ /* page got truncated out from underneath us */
+ goto out_unlock;
+ }
+ wait_on_page_writeback(page);
+
+ lock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ set_page_extent_mapped(page);
+
+ /*
+ * we can't set the delalloc bits if there are pending ordered
+ * extents. Drop our locks and wait for them to finish
+ */
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+ ret = 0;
+
+ /* page is wholly or partially inside EOF */
+ if (page_start + PAGE_CACHE_SIZE > size)
+ zero_start = size & ~PAGE_CACHE_MASK;
+ else
+ zero_start = PAGE_CACHE_SIZE;
+
+ if (zero_start != PAGE_CACHE_SIZE) {
+ kaddr = kmap(page);
+ memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
+ flush_dcache_page(page);
+ kunmap(page);
+ }
+ ClearPageChecked(page);
+ set_page_dirty(page);
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+
+out_unlock:
+ unlock_page(page);
+out:
+ return ret;
+}
+
+static void btrfs_truncate(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr;
+ u64 mask = root->sectorsize - 1;
+
+ if (!S_ISREG(inode->i_mode))
+ return;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return;
+
+ btrfs_truncate_page(inode->i_mapping, inode->i_size);
+ btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ btrfs_i_size_write(inode, inode->i_size);
+
+ ret = btrfs_orphan_add(trans, inode);
+ if (ret)
+ goto out;
+ /* FIXME, add redo link to tree so we don't leak on crash */
+ ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size,
+ BTRFS_EXTENT_DATA_KEY);
+ btrfs_update_inode(trans, root, inode);
+
+ ret = btrfs_orphan_del(trans, inode);
+ BUG_ON(ret);
+
+out:
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction_throttle(trans, root);
+ BUG_ON(ret);
+ btrfs_btree_balance_dirty(root, nr);
+}
+
+/*
+ * Invalidate a single dcache entry at the root of the filesystem.
+ * Needed after creation of snapshot or subvolume.
+ */
+void btrfs_invalidate_dcache_root(struct inode *dir, char *name,
+ int namelen)
+{
+ struct dentry *alias, *entry;
+ struct qstr qstr;
+
+ alias = d_find_alias(dir);
+ if (alias) {
+ qstr.name = name;
+ qstr.len = namelen;
+ /* change me if btrfs ever gets a d_hash operation */
+ qstr.hash = full_name_hash(qstr.name, qstr.len);
+ entry = d_lookup(alias, &qstr);
+ dput(alias);
+ if (entry) {
+ d_invalidate(entry);
+ dput(entry);
+ }
+ }
+}
+
+/*
+ * create a new subvolume directory/inode (helper for the ioctl).
+ */
+int btrfs_create_subvol_root(struct btrfs_root *new_root, struct dentry *dentry,
+ struct btrfs_trans_handle *trans, u64 new_dirid,
+ struct btrfs_block_group_cache *block_group)
+{
+ struct inode *inode;
+ int error;
+ u64 index = 0;
+
+ inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
+ new_dirid, block_group, S_IFDIR | 0700, &index);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+
+ inode->i_nlink = 1;
+ btrfs_i_size_write(inode, 0);
+
+ error = btrfs_update_inode(trans, new_root, inode);
+ if (error)
+ return error;
+
+ d_instantiate(dentry, inode);
+ return 0;
+}
+
+/* helper function for file defrag and space balancing. This
+ * forces readahead on a given range of bytes in an inode
+ */
+unsigned long btrfs_force_ra(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *file,
+ pgoff_t offset, pgoff_t last_index)
+{
+ pgoff_t req_size = last_index - offset + 1;
+
+ page_cache_sync_readahead(mapping, ra, file, offset, req_size);
+ return offset + req_size;
+}
+
+struct inode *btrfs_alloc_inode(struct super_block *sb)
+{
+ struct btrfs_inode *ei;
+
+ ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
+ if (!ei)
+ return NULL;
+ ei->last_trans = 0;
+ ei->logged_trans = 0;
+ btrfs_ordered_inode_tree_init(&ei->ordered_tree);
+ ei->i_acl = BTRFS_ACL_NOT_CACHED;
+ ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
+ INIT_LIST_HEAD(&ei->i_orphan);
+ return &ei->vfs_inode;
+}
+
+void btrfs_destroy_inode(struct inode *inode)
+{
+ struct btrfs_ordered_extent *ordered;
+ WARN_ON(!list_empty(&inode->i_dentry));
+ WARN_ON(inode->i_data.nrpages);
+
+ if (BTRFS_I(inode)->i_acl &&
+ BTRFS_I(inode)->i_acl != BTRFS_ACL_NOT_CACHED)
+ posix_acl_release(BTRFS_I(inode)->i_acl);
+ if (BTRFS_I(inode)->i_default_acl &&
+ BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
+ posix_acl_release(BTRFS_I(inode)->i_default_acl);
+
+ spin_lock(&BTRFS_I(inode)->root->list_lock);
+ if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
+ printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
+ " list\n", inode->i_ino);
+ dump_stack();
+ }
+ spin_unlock(&BTRFS_I(inode)->root->list_lock);
+
+ while(1) {
+ ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
+ if (!ordered)
+ break;
+ else {
+ printk("found ordered extent %Lu %Lu\n",
+ ordered->file_offset, ordered->len);
+ btrfs_remove_ordered_extent(inode, ordered);
+ btrfs_put_ordered_extent(ordered);
+ btrfs_put_ordered_extent(ordered);
+ }
+ }
+ btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
+ kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+
+static void init_once(void *foo)
+{
+ struct btrfs_inode *ei = (struct btrfs_inode *) foo;
+
+ inode_init_once(&ei->vfs_inode);
+}
+
+void btrfs_destroy_cachep(void)
+{
+ if (btrfs_inode_cachep)
+ kmem_cache_destroy(btrfs_inode_cachep);
+ if (btrfs_trans_handle_cachep)
+ kmem_cache_destroy(btrfs_trans_handle_cachep);
+ if (btrfs_transaction_cachep)
+ kmem_cache_destroy(btrfs_transaction_cachep);
+ if (btrfs_bit_radix_cachep)
+ kmem_cache_destroy(btrfs_bit_radix_cachep);
+ if (btrfs_path_cachep)
+ kmem_cache_destroy(btrfs_path_cachep);
+}
+
+struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
+ unsigned long extra_flags,
+ void (*ctor)(void *))
+{
+ return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
+ SLAB_MEM_SPREAD | extra_flags), ctor);
+}
+
+int btrfs_init_cachep(void)
+{
+ btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
+ sizeof(struct btrfs_inode),
+ 0, init_once);
+ if (!btrfs_inode_cachep)
+ goto fail;
+ btrfs_trans_handle_cachep =
+ btrfs_cache_create("btrfs_trans_handle_cache",
+ sizeof(struct btrfs_trans_handle),
+ 0, NULL);
+ if (!btrfs_trans_handle_cachep)
+ goto fail;
+ btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
+ sizeof(struct btrfs_transaction),
+ 0, NULL);
+ if (!btrfs_transaction_cachep)
+ goto fail;
+ btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
+ sizeof(struct btrfs_path),
+ 0, NULL);
+ if (!btrfs_path_cachep)
+ goto fail;
+ btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
+ SLAB_DESTROY_BY_RCU, NULL);
+ if (!btrfs_bit_radix_cachep)
+ goto fail;
+ return 0;
+fail:
+ btrfs_destroy_cachep();
+ return -ENOMEM;
+}
+
+static int btrfs_getattr(struct vfsmount *mnt,
+ struct dentry *dentry, struct kstat *stat)
+{
+ struct inode *inode = dentry->d_inode;
+ generic_fillattr(inode, stat);
+ stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
+ stat->blksize = PAGE_CACHE_SIZE;
+ stat->blocks = (inode_get_bytes(inode) +
+ BTRFS_I(inode)->delalloc_bytes) >> 9;
+ return 0;
+}
+
+static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
+ struct inode * new_dir,struct dentry *new_dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(old_dir)->root;
+ struct inode *new_inode = new_dentry->d_inode;
+ struct inode *old_inode = old_dentry->d_inode;
+ struct timespec ctime = CURRENT_TIME;
+ u64 index = 0;
+ int ret;
+
+ /* we're not allowed to rename between subvolumes */
+ if (BTRFS_I(old_inode)->root->root_key.objectid !=
+ BTRFS_I(new_dir)->root->root_key.objectid)
+ return -EXDEV;
+
+ if (S_ISDIR(old_inode->i_mode) && new_inode &&
+ new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
+ return -ENOTEMPTY;
+ }
+
+ /* to rename a snapshot or subvolume, we need to juggle the
+ * backrefs. This isn't coded yet
+ */
+ if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
+ return -EXDEV;
+
+ ret = btrfs_check_free_space(root, 1, 0);
+ if (ret)
+ goto out_unlock;
+
+ trans = btrfs_start_transaction(root, 1);
+
+ btrfs_set_trans_block_group(trans, new_dir);
+
+ btrfs_inc_nlink(old_dentry->d_inode);
+ old_dir->i_ctime = old_dir->i_mtime = ctime;
+ new_dir->i_ctime = new_dir->i_mtime = ctime;
+ old_inode->i_ctime = ctime;
+
+ ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode,
+ old_dentry->d_name.name,
+ old_dentry->d_name.len);
+ if (ret)
+ goto out_fail;
+
+ if (new_inode) {
+ new_inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_unlink_inode(trans, root, new_dir,
+ new_dentry->d_inode,
+ new_dentry->d_name.name,
+ new_dentry->d_name.len);
+ if (ret)
+ goto out_fail;
+ if (new_inode->i_nlink == 0) {
+ ret = btrfs_orphan_add(trans, new_dentry->d_inode);
+ if (ret)
+ goto out_fail;
+ }
+
+ }
+ ret = btrfs_set_inode_index(new_dir, &index);
+ if (ret)
+ goto out_fail;
+
+ ret = btrfs_add_link(trans, new_dentry->d_parent->d_inode,
+ old_inode, new_dentry->d_name.name,
+ new_dentry->d_name.len, 1, index);
+ if (ret)
+ goto out_fail;
+
+out_fail:
+ btrfs_end_transaction_throttle(trans, root);
+out_unlock:
+ return ret;
+}
+
+/*
+ * some fairly slow code that needs optimization. This walks the list
+ * of all the inodes with pending delalloc and forces them to disk.
+ */
+int btrfs_start_delalloc_inodes(struct btrfs_root *root)
+{
+ struct list_head *head = &root->fs_info->delalloc_inodes;
+ struct btrfs_inode *binode;
+ struct inode *inode;
+ unsigned long flags;
+
+ if (root->fs_info->sb->s_flags & MS_RDONLY)
+ return -EROFS;
+
+ spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
+ while(!list_empty(head)) {
+ binode = list_entry(head->next, struct btrfs_inode,
+ delalloc_inodes);
+ inode = igrab(&binode->vfs_inode);
+ if (!inode)
+ list_del_init(&binode->delalloc_inodes);
+ spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
+ if (inode) {
+ filemap_flush(inode->i_mapping);
+ iput(inode);
+ }
+ cond_resched();
+ spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
+ }
+ spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
+
+ /* the filemap_flush will queue IO into the worker threads, but
+ * we have to make sure the IO is actually started and that
+ * ordered extents get created before we return
+ */
+ atomic_inc(&root->fs_info->async_submit_draining);
+ while(atomic_read(&root->fs_info->nr_async_submits) ||
+ atomic_read(&root->fs_info->async_delalloc_pages)) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
+ atomic_read(&root->fs_info->async_delalloc_pages) == 0));
+ }
+ atomic_dec(&root->fs_info->async_submit_draining);
+ return 0;
+}
+
+static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+ u64 index = 0 ;
+ int name_len;
+ int datasize;
+ unsigned long ptr;
+ struct btrfs_file_extent_item *ei;
+ struct extent_buffer *leaf;
+ unsigned long nr = 0;
+
+ name_len = strlen(symname) + 1;
+ if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
+ return -ENAMETOOLONG;
+
+ err = btrfs_check_free_space(root, 1, 0);
+ if (err)
+ goto out_fail;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino, objectid,
+ BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO,
+ &index);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ err = btrfs_init_acl(inode, dir);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode, 0, index);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+ if (drop_inode)
+ goto out_unlock;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ key.objectid = inode->i_ino;
+ key.offset = 0;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+ datasize = btrfs_file_extent_calc_inline_size(name_len);
+ err = btrfs_insert_empty_item(trans, root, path, &key,
+ datasize);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock;
+ }
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, ei, trans->transid);
+ btrfs_set_file_extent_type(leaf, ei,
+ BTRFS_FILE_EXTENT_INLINE);
+ btrfs_set_file_extent_encryption(leaf, ei, 0);
+ btrfs_set_file_extent_compression(leaf, ei, 0);
+ btrfs_set_file_extent_other_encoding(leaf, ei, 0);
+ btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
+
+ ptr = btrfs_file_extent_inline_start(ei);
+ write_extent_buffer(leaf, symname, ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_free_path(path);
+
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ inode_set_bytes(inode, name_len);
+ btrfs_i_size_write(inode, name_len - 1);
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ drop_inode = 1;
+
+out_unlock:
+ nr = trans->blocks_used;
+ btrfs_end_transaction_throttle(trans, root);
+out_fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root, nr);
+ return err;
+}
+
+static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
+ u64 alloc_hint, int mode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key ins;
+ u64 alloc_size;
+ u64 cur_offset = start;
+ u64 num_bytes = end - start;
+ int ret = 0;
+
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+ btrfs_set_trans_block_group(trans, inode);
+
+ while (num_bytes > 0) {
+ alloc_size = min(num_bytes, root->fs_info->max_extent);
+ ret = btrfs_reserve_extent(trans, root, alloc_size,
+ root->sectorsize, 0, alloc_hint,
+ (u64)-1, &ins, 1);
+ if (ret) {
+ WARN_ON(1);
+ goto out;
+ }
+ ret = insert_reserved_file_extent(trans, inode,
+ cur_offset, ins.objectid,
+ ins.offset, ins.offset,
+ ins.offset, 0, 0, 0,
+ BTRFS_FILE_EXTENT_PREALLOC);
+ BUG_ON(ret);
+ num_bytes -= ins.offset;
+ cur_offset += ins.offset;
+ alloc_hint = ins.objectid + ins.offset;
+ }
+out:
+ if (cur_offset > start) {
+ inode->i_ctime = CURRENT_TIME;
+ btrfs_set_flag(inode, PREALLOC);
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ cur_offset > i_size_read(inode))
+ btrfs_i_size_write(inode, cur_offset);
+ ret = btrfs_update_inode(trans, root, inode);
+ BUG_ON(ret);
+ }
+
+ btrfs_end_transaction(trans, root);
+ return ret;
+}
+
+static long btrfs_fallocate(struct inode *inode, int mode,
+ loff_t offset, loff_t len)
+{
+ u64 cur_offset;
+ u64 last_byte;
+ u64 alloc_start;
+ u64 alloc_end;
+ u64 alloc_hint = 0;
+ u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
+ struct extent_map *em;
+ int ret;
+
+ alloc_start = offset & ~mask;
+ alloc_end = (offset + len + mask) & ~mask;
+
+ mutex_lock(&inode->i_mutex);
+ if (alloc_start > inode->i_size) {
+ ret = btrfs_cont_expand(inode, alloc_start);
+ if (ret)
+ goto out;
+ }
+
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+ lock_extent(&BTRFS_I(inode)->io_tree, alloc_start,
+ alloc_end - 1, GFP_NOFS);
+ ordered = btrfs_lookup_first_ordered_extent(inode,
+ alloc_end - 1);
+ if (ordered &&
+ ordered->file_offset + ordered->len > alloc_start &&
+ ordered->file_offset < alloc_end) {
+ btrfs_put_ordered_extent(ordered);
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ alloc_start, alloc_end - 1, GFP_NOFS);
+ btrfs_wait_ordered_range(inode, alloc_start,
+ alloc_end - alloc_start);
+ } else {
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ }
+
+ cur_offset = alloc_start;
+ while (1) {
+ em = btrfs_get_extent(inode, NULL, 0, cur_offset,
+ alloc_end - cur_offset, 0);
+ BUG_ON(IS_ERR(em) || !em);
+ last_byte = min(extent_map_end(em), alloc_end);
+ last_byte = (last_byte + mask) & ~mask;
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ ret = prealloc_file_range(inode, cur_offset,
+ last_byte, alloc_hint, mode);
+ if (ret < 0) {
+ free_extent_map(em);
+ break;
+ }
+ }
+ if (em->block_start <= EXTENT_MAP_LAST_BYTE)
+ alloc_hint = em->block_start;
+ free_extent_map(em);
+
+ cur_offset = last_byte;
+ if (cur_offset >= alloc_end) {
+ ret = 0;
+ break;
+ }
+ }
+ unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, alloc_end - 1,
+ GFP_NOFS);
+out:
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+}
+
+static int btrfs_set_page_dirty(struct page *page)
+{
+ return __set_page_dirty_nobuffers(page);
+}
+
+static int btrfs_permission(struct inode *inode, int mask)
+{
+ if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
+ return -EACCES;
+ return generic_permission(inode, mask, btrfs_check_acl);
+}
+
+static struct inode_operations btrfs_dir_inode_operations = {
+ .getattr = btrfs_getattr,
+ .lookup = btrfs_lookup,
+ .create = btrfs_create,
+ .unlink = btrfs_unlink,
+ .link = btrfs_link,
+ .mkdir = btrfs_mkdir,
+ .rmdir = btrfs_rmdir,
+ .rename = btrfs_rename,
+ .symlink = btrfs_symlink,
+ .setattr = btrfs_setattr,
+ .mknod = btrfs_mknod,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .permission = btrfs_permission,
+};
+static struct inode_operations btrfs_dir_ro_inode_operations = {
+ .lookup = btrfs_lookup,
+ .permission = btrfs_permission,
+};
+static struct file_operations btrfs_dir_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .readdir = btrfs_real_readdir,
+ .unlocked_ioctl = btrfs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = btrfs_ioctl,
+#endif
+ .release = btrfs_release_file,
+ .fsync = btrfs_sync_file,
+};
+
+static struct extent_io_ops btrfs_extent_io_ops = {
+ .fill_delalloc = run_delalloc_range,
+ .submit_bio_hook = btrfs_submit_bio_hook,
+ .merge_bio_hook = btrfs_merge_bio_hook,
+ .readpage_end_io_hook = btrfs_readpage_end_io_hook,
+ .writepage_end_io_hook = btrfs_writepage_end_io_hook,
+ .writepage_start_hook = btrfs_writepage_start_hook,
+ .readpage_io_failed_hook = btrfs_io_failed_hook,
+ .set_bit_hook = btrfs_set_bit_hook,
+ .clear_bit_hook = btrfs_clear_bit_hook,
+};
+
+static struct address_space_operations btrfs_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+ .writepages = btrfs_writepages,
+ .readpages = btrfs_readpages,
+ .sync_page = block_sync_page,
+ .bmap = btrfs_bmap,
+ .direct_IO = btrfs_direct_IO,
+ .invalidatepage = btrfs_invalidatepage,
+ .releasepage = btrfs_releasepage,
+ .set_page_dirty = btrfs_set_page_dirty,
+};
+
+static struct address_space_operations btrfs_symlink_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+ .invalidatepage = btrfs_invalidatepage,
+ .releasepage = btrfs_releasepage,
+};
+
+static struct inode_operations btrfs_file_inode_operations = {
+ .truncate = btrfs_truncate,
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .permission = btrfs_permission,
+ .fallocate = btrfs_fallocate,
+};
+static struct inode_operations btrfs_special_inode_operations = {
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+ .permission = btrfs_permission,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+};
+static struct inode_operations btrfs_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
+ .permission = btrfs_permission,
+};
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
new file mode 100644
index 0000000..8828109
--- /dev/null
+++ b/fs/btrfs/ioctl.c
@@ -0,0 +1,1150 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mount.h>
+#include <linux/mpage.h>
+#include <linux/namei.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/bit_spinlock.h>
+#include <linux/security.h>
+#include <linux/version.h>
+#include <linux/xattr.h>
+#include <linux/vmalloc.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "locking.h"
+
+
+
+static noinline int create_subvol(struct btrfs_root *root,
+ struct dentry *dentry,
+ char *name, int namelen)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_root_item root_item;
+ struct btrfs_inode_item *inode_item;
+ struct extent_buffer *leaf;
+ struct btrfs_root *new_root = root;
+ struct inode *dir;
+ int ret;
+ int err;
+ u64 objectid;
+ u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
+ u64 index = 0;
+ unsigned long nr = 1;
+
+ ret = btrfs_check_free_space(root, 1, 0);
+ if (ret)
+ goto fail_commit;
+
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+
+ ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
+ 0, &objectid);
+ if (ret)
+ goto fail;
+
+ leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
+ objectid, trans->transid, 0, 0, 0);
+ if (IS_ERR(leaf)) {
+ ret = PTR_ERR(leaf);
+ goto fail;
+ }
+
+ btrfs_set_header_nritems(leaf, 0);
+ btrfs_set_header_level(leaf, 0);
+ btrfs_set_header_bytenr(leaf, leaf->start);
+ btrfs_set_header_generation(leaf, trans->transid);
+ btrfs_set_header_owner(leaf, objectid);
+
+ write_extent_buffer(leaf, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(leaf),
+ BTRFS_FSID_SIZE);
+ btrfs_mark_buffer_dirty(leaf);
+
+ inode_item = &root_item.inode;
+ memset(inode_item, 0, sizeof(*inode_item));
+ inode_item->generation = cpu_to_le64(1);
+ inode_item->size = cpu_to_le64(3);
+ inode_item->nlink = cpu_to_le32(1);
+ inode_item->nbytes = cpu_to_le64(root->leafsize);
+ inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
+
+ btrfs_set_root_bytenr(&root_item, leaf->start);
+ btrfs_set_root_generation(&root_item, trans->transid);
+ btrfs_set_root_level(&root_item, 0);
+ btrfs_set_root_refs(&root_item, 1);
+ btrfs_set_root_used(&root_item, 0);
+ btrfs_set_root_last_snapshot(&root_item, 0);
+
+ memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
+ root_item.drop_level = 0;
+
+ btrfs_tree_unlock(leaf);
+ free_extent_buffer(leaf);
+ leaf = NULL;
+
+ btrfs_set_root_dirid(&root_item, new_dirid);
+
+ key.objectid = objectid;
+ key.offset = 1;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+ &root_item);
+ if (ret)
+ goto fail;
+
+ /*
+ * insert the directory item
+ */
+ key.offset = (u64)-1;
+ dir = dentry->d_parent->d_inode;
+ ret = btrfs_set_inode_index(dir, &index);
+ BUG_ON(ret);
+
+ ret = btrfs_insert_dir_item(trans, root,
+ name, namelen, dir->i_ino, &key,
+ BTRFS_FT_DIR, index);
+ if (ret)
+ goto fail;
+
+ /* add the backref first */
+ ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
+ objectid, BTRFS_ROOT_BACKREF_KEY,
+ root->root_key.objectid,
+ dir->i_ino, index, name, namelen);
+
+ BUG_ON(ret);
+
+ /* now add the forward ref */
+ ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
+ root->root_key.objectid, BTRFS_ROOT_REF_KEY,
+ objectid,
+ dir->i_ino, index, name, namelen);
+
+ BUG_ON(ret);
+
+ ret = btrfs_commit_transaction(trans, root);
+ if (ret)
+ goto fail_commit;
+
+ new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
+ BUG_ON(!new_root);
+
+ trans = btrfs_start_transaction(new_root, 1);
+ BUG_ON(!trans);
+
+ ret = btrfs_create_subvol_root(new_root, dentry, trans, new_dirid,
+ BTRFS_I(dir)->block_group);
+ if (ret)
+ goto fail;
+
+fail:
+ nr = trans->blocks_used;
+ err = btrfs_commit_transaction(trans, new_root);
+ if (err && !ret)
+ ret = err;
+fail_commit:
+ btrfs_btree_balance_dirty(root, nr);
+ return ret;
+}
+
+static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
+ char *name, int namelen)
+{
+ struct btrfs_pending_snapshot *pending_snapshot;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+ int err;
+ unsigned long nr = 0;
+
+ if (!root->ref_cows)
+ return -EINVAL;
+
+ ret = btrfs_check_free_space(root, 1, 0);
+ if (ret)
+ goto fail_unlock;
+
+ pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
+ if (!pending_snapshot) {
+ ret = -ENOMEM;
+ goto fail_unlock;
+ }
+ pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
+ if (!pending_snapshot->name) {
+ ret = -ENOMEM;
+ kfree(pending_snapshot);
+ goto fail_unlock;
+ }
+ memcpy(pending_snapshot->name, name, namelen);
+ pending_snapshot->name[namelen] = '\0';
+ pending_snapshot->dentry = dentry;
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+ pending_snapshot->root = root;
+ list_add(&pending_snapshot->list,
+ &trans->transaction->pending_snapshots);
+ err = btrfs_commit_transaction(trans, root);
+
+fail_unlock:
+ btrfs_btree_balance_dirty(root, nr);
+ return ret;
+}
+
+/* copy of may_create in fs/namei.c() */
+static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
+{
+ if (child->d_inode)
+ return -EEXIST;
+ if (IS_DEADDIR(dir))
+ return -ENOENT;
+ return inode_permission(dir, MAY_WRITE | MAY_EXEC);
+}
+
+/*
+ * Create a new subvolume below @parent. This is largely modeled after
+ * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
+ * inside this filesystem so it's quite a bit simpler.
+ */
+static noinline int btrfs_mksubvol(struct path *parent, char *name,
+ int mode, int namelen,
+ struct btrfs_root *snap_src)
+{
+ struct dentry *dentry;
+ int error;
+
+ mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+
+ dentry = lookup_one_len(name, parent->dentry, namelen);
+ error = PTR_ERR(dentry);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+
+ error = -EEXIST;
+ if (dentry->d_inode)
+ goto out_dput;
+
+ if (!IS_POSIXACL(parent->dentry->d_inode))
+ mode &= ~current->fs->umask;
+
+ error = mnt_want_write(parent->mnt);
+ if (error)
+ goto out_dput;
+
+ error = btrfs_may_create(parent->dentry->d_inode, dentry);
+ if (error)
+ goto out_drop_write;
+
+ /*
+ * Actually perform the low-level subvolume creation after all
+ * this VFS fuzz.
+ *
+ * Eventually we want to pass in an inode under which we create this
+ * subvolume, but for now all are under the filesystem root.
+ *
+ * Also we should pass on the mode eventually to allow creating new
+ * subvolume with specific mode bits.
+ */
+ if (snap_src) {
+ struct dentry *dir = dentry->d_parent;
+ struct dentry *test = dir->d_parent;
+ struct btrfs_path *path = btrfs_alloc_path();
+ int ret;
+ u64 test_oid;
+ u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid;
+
+ test_oid = snap_src->root_key.objectid;
+
+ ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
+ path, parent_oid, test_oid);
+ if (ret == 0)
+ goto create;
+ btrfs_release_path(snap_src->fs_info->tree_root, path);
+
+ /* we need to make sure we aren't creating a directory loop
+ * by taking a snapshot of something that has our current
+ * subvol in its directory tree. So, this loops through
+ * the dentries and checks the forward refs for each subvolume
+ * to see if is references the subvolume where we are
+ * placing this new snapshot.
+ */
+ while(1) {
+ if (!test ||
+ dir == snap_src->fs_info->sb->s_root ||
+ test == snap_src->fs_info->sb->s_root ||
+ test->d_inode->i_sb != snap_src->fs_info->sb) {
+ break;
+ }
+ if (S_ISLNK(test->d_inode->i_mode)) {
+ printk("Symlink in snapshot path, failed\n");
+ error = -EMLINK;
+ btrfs_free_path(path);
+ goto out_drop_write;
+ }
+ test_oid =
+ BTRFS_I(test->d_inode)->root->root_key.objectid;
+ ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
+ path, test_oid, parent_oid);
+ if (ret == 0) {
+ printk("Snapshot creation failed, looping\n");
+ error = -EMLINK;
+ btrfs_free_path(path);
+ goto out_drop_write;
+ }
+ btrfs_release_path(snap_src->fs_info->tree_root, path);
+ test = test->d_parent;
+ }
+create:
+ btrfs_free_path(path);
+ error = create_snapshot(snap_src, dentry, name, namelen);
+ } else {
+ error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root,
+ dentry, name, namelen);
+ }
+ if (error)
+ goto out_drop_write;
+
+ fsnotify_mkdir(parent->dentry->d_inode, dentry);
+out_drop_write:
+ mnt_drop_write(parent->mnt);
+out_dput:
+ dput(dentry);
+out_unlock:
+ mutex_unlock(&parent->dentry->d_inode->i_mutex);
+ return error;
+}
+
+
+int btrfs_defrag_file(struct file *file)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_ordered_extent *ordered;
+ struct page *page;
+ unsigned long last_index;
+ unsigned long ra_pages = root->fs_info->bdi.ra_pages;
+ unsigned long total_read = 0;
+ u64 page_start;
+ u64 page_end;
+ unsigned long i;
+ int ret;
+
+ ret = btrfs_check_free_space(root, inode->i_size, 0);
+ if (ret)
+ return -ENOSPC;
+
+ mutex_lock(&inode->i_mutex);
+ last_index = inode->i_size >> PAGE_CACHE_SHIFT;
+ for (i = 0; i <= last_index; i++) {
+ if (total_read % ra_pages == 0) {
+ btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
+ min(last_index, i + ra_pages - 1));
+ }
+ total_read++;
+again:
+ page = grab_cache_page(inode->i_mapping, i);
+ if (!page)
+ goto out_unlock;
+ if (!PageUptodate(page)) {
+ btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto out_unlock;
+ }
+ }
+
+ wait_on_page_writeback(page);
+
+ page_start = (u64)page->index << PAGE_CACHE_SHIFT;
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+ lock_extent(io_tree, page_start, page_end, GFP_NOFS);
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+ set_page_extent_mapped(page);
+
+ /*
+ * this makes sure page_mkwrite is called on the
+ * page if it is dirtied again later
+ */
+ clear_page_dirty_for_io(page);
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+
+ unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+ balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
+ }
+
+out_unlock:
+ mutex_unlock(&inode->i_mutex);
+ return 0;
+}
+
+/*
+ * Called inside transaction, so use GFP_NOFS
+ */
+
+static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
+{
+ u64 new_size;
+ u64 old_size;
+ u64 devid = 1;
+ struct btrfs_ioctl_vol_args *vol_args;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_device *device = NULL;
+ char *sizestr;
+ char *devstr = NULL;
+ int ret = 0;
+ int namelen;
+ int mod = 0;
+
+ if (root->fs_info->sb->s_flags & MS_RDONLY)
+ return -EROFS;
+
+ vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+
+ if (!vol_args)
+ return -ENOMEM;
+
+ if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
+ namelen = strlen(vol_args->name);
+
+ mutex_lock(&root->fs_info->volume_mutex);
+ sizestr = vol_args->name;
+ devstr = strchr(sizestr, ':');
+ if (devstr) {
+ char *end;
+ sizestr = devstr + 1;
+ *devstr = '\0';
+ devstr = vol_args->name;
+ devid = simple_strtoull(devstr, &end, 10);
+ printk(KERN_INFO "resizing devid %llu\n", devid);
+ }
+ device = btrfs_find_device(root, devid, NULL, NULL);
+ if (!device) {
+ printk(KERN_INFO "resizer unable to find device %llu\n", devid);
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (!strcmp(sizestr, "max"))
+ new_size = device->bdev->bd_inode->i_size;
+ else {
+ if (sizestr[0] == '-') {
+ mod = -1;
+ sizestr++;
+ } else if (sizestr[0] == '+') {
+ mod = 1;
+ sizestr++;
+ }
+ new_size = btrfs_parse_size(sizestr);
+ if (new_size == 0) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ }
+
+ old_size = device->total_bytes;
+
+ if (mod < 0) {
+ if (new_size > old_size) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ new_size = old_size - new_size;
+ } else if (mod > 0) {
+ new_size = old_size + new_size;
+ }
+
+ if (new_size < 256 * 1024 * 1024) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (new_size > device->bdev->bd_inode->i_size) {
+ ret = -EFBIG;
+ goto out_unlock;
+ }
+
+ do_div(new_size, root->sectorsize);
+ new_size *= root->sectorsize;
+
+ printk(KERN_INFO "new size for %s is %llu\n",
+ device->name, (unsigned long long)new_size);
+
+ if (new_size > old_size) {
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_grow_device(trans, device, new_size);
+ btrfs_commit_transaction(trans, root);
+ } else {
+ ret = btrfs_shrink_device(device, new_size);
+ }
+
+out_unlock:
+ mutex_unlock(&root->fs_info->volume_mutex);
+out:
+ kfree(vol_args);
+ return ret;
+}
+
+static noinline int btrfs_ioctl_snap_create(struct file *file,
+ void __user *arg, int subvol)
+{
+ struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
+ struct btrfs_ioctl_vol_args *vol_args;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ struct file *src_file;
+ u64 root_dirid;
+ int namelen;
+ int ret = 0;
+
+ if (root->fs_info->sb->s_flags & MS_RDONLY)
+ return -EROFS;
+
+ vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+
+ if (!vol_args)
+ return -ENOMEM;
+
+ if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
+ namelen = strlen(vol_args->name);
+ if (strchr(vol_args->name, '/')) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
+ di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
+ path, root_dirid,
+ vol_args->name, namelen, 0);
+ btrfs_free_path(path);
+
+ if (di && !IS_ERR(di)) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ }
+
+ if (subvol) {
+ ret = btrfs_mksubvol(&file->f_path, vol_args->name,
+ file->f_path.dentry->d_inode->i_mode,
+ namelen, NULL);
+ } else {
+ struct inode *src_inode;
+ src_file = fget(vol_args->fd);
+ if (!src_file) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ src_inode = src_file->f_path.dentry->d_inode;
+ if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
+ printk("btrfs: Snapshot src from another FS\n");
+ ret = -EINVAL;
+ fput(src_file);
+ goto out;
+ }
+ ret = btrfs_mksubvol(&file->f_path, vol_args->name,
+ file->f_path.dentry->d_inode->i_mode,
+ namelen, BTRFS_I(src_inode)->root);
+ fput(src_file);
+ }
+
+out:
+ kfree(vol_args);
+ return ret;
+}
+
+static int btrfs_ioctl_defrag(struct file *file)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ ret = mnt_want_write(file->f_path.mnt);
+ if (ret)
+ return ret;
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFDIR:
+ btrfs_defrag_root(root, 0);
+ btrfs_defrag_root(root->fs_info->extent_root, 0);
+ break;
+ case S_IFREG:
+ btrfs_defrag_file(file);
+ break;
+ }
+
+ return 0;
+}
+
+long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
+{
+ struct btrfs_ioctl_vol_args *vol_args;
+ int ret;
+
+ vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+
+ if (!vol_args)
+ return -ENOMEM;
+
+ if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
+ ret = -EFAULT;
+ goto out;
+ }
+ vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
+ ret = btrfs_init_new_device(root, vol_args->name);
+
+out:
+ kfree(vol_args);
+ return ret;
+}
+
+long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
+{
+ struct btrfs_ioctl_vol_args *vol_args;
+ int ret;
+
+ if (root->fs_info->sb->s_flags & MS_RDONLY)
+ return -EROFS;
+
+ vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+
+ if (!vol_args)
+ return -ENOMEM;
+
+ if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
+ ret = -EFAULT;
+ goto out;
+ }
+ vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
+ ret = btrfs_rm_device(root, vol_args->name);
+
+out:
+ kfree(vol_args);
+ return ret;
+}
+
+long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, u64 off,
+ u64 olen, u64 destoff)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct file *src_file;
+ struct inode *src;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ char *buf;
+ struct btrfs_key key;
+ u32 nritems;
+ int slot;
+ int ret;
+ u64 len = olen;
+ u64 bs = root->fs_info->sb->s_blocksize;
+ u64 hint_byte;
+
+ /*
+ * TODO:
+ * - split compressed inline extents. annoying: we need to
+ * decompress into destination's address_space (the file offset
+ * may change, so source mapping won't do), then recompress (or
+ * otherwise reinsert) a subrange.
+ * - allow ranges within the same file to be cloned (provided
+ * they don't overlap)?
+ */
+
+ ret = mnt_want_write(file->f_path.mnt);
+ if (ret)
+ return ret;
+
+ src_file = fget(srcfd);
+ if (!src_file)
+ return -EBADF;
+ src = src_file->f_dentry->d_inode;
+
+ ret = -EINVAL;
+ if (src == inode)
+ goto out_fput;
+
+ ret = -EISDIR;
+ if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
+ goto out_fput;
+
+ ret = -EXDEV;
+ if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
+ goto out_fput;
+
+ ret = -ENOMEM;
+ buf = vmalloc(btrfs_level_size(root, 0));
+ if (!buf)
+ goto out_fput;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ vfree(buf);
+ goto out_fput;
+ }
+ path->reada = 2;
+
+ if (inode < src) {
+ mutex_lock(&inode->i_mutex);
+ mutex_lock(&src->i_mutex);
+ } else {
+ mutex_lock(&src->i_mutex);
+ mutex_lock(&inode->i_mutex);
+ }
+
+ /* determine range to clone */
+ ret = -EINVAL;
+ if (off >= src->i_size || off + len > src->i_size)
+ goto out_unlock;
+ if (len == 0)
+ olen = len = src->i_size - off;
+ /* if we extend to eof, continue to block boundary */
+ if (off + len == src->i_size)
+ len = ((src->i_size + bs-1) & ~(bs-1))
+ - off;
+
+ /* verify the end result is block aligned */
+ if ((off & (bs-1)) ||
+ ((off + len) & (bs-1)))
+ goto out_unlock;
+
+ printk("final src extent is %llu~%llu\n", off, len);
+ printk("final dst extent is %llu~%llu\n", destoff, len);
+
+ /* do any pending delalloc/csum calc on src, one way or
+ another, and lock file content */
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+ lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
+ ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
+ if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
+ break;
+ unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+ btrfs_wait_ordered_range(src, off, off+len);
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+
+ /* punch hole in destination first */
+ btrfs_drop_extents(trans, root, inode, off, off+len, 0, &hint_byte);
+
+ /* clone data */
+ key.objectid = src->i_ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = 0;
+
+ while (1) {
+ /*
+ * note the key will change type as we walk through the
+ * tree.
+ */
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
+ break;
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ }
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY ||
+ key.objectid != src->i_ino)
+ break;
+
+ if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
+ struct btrfs_file_extent_item *extent;
+ int type;
+ u32 size;
+ struct btrfs_key new_key;
+ u64 disko = 0, diskl = 0;
+ u64 datao = 0, datal = 0;
+ u8 comp;
+
+ size = btrfs_item_size_nr(leaf, slot);
+ read_extent_buffer(leaf, buf,
+ btrfs_item_ptr_offset(leaf, slot),
+ size);
+
+ extent = btrfs_item_ptr(leaf, slot,
+ struct btrfs_file_extent_item);
+ comp = btrfs_file_extent_compression(leaf, extent);
+ type = btrfs_file_extent_type(leaf, extent);
+ if (type == BTRFS_FILE_EXTENT_REG) {
+ disko = btrfs_file_extent_disk_bytenr(leaf, extent);
+ diskl = btrfs_file_extent_disk_num_bytes(leaf, extent);
+ datao = btrfs_file_extent_offset(leaf, extent);
+ datal = btrfs_file_extent_num_bytes(leaf, extent);
+ } else if (type == BTRFS_FILE_EXTENT_INLINE) {
+ /* take upper bound, may be compressed */
+ datal = btrfs_file_extent_ram_bytes(leaf,
+ extent);
+ }
+ btrfs_release_path(root, path);
+
+ if (key.offset + datal < off ||
+ key.offset >= off+len)
+ goto next;
+
+ memcpy(&new_key, &key, sizeof(new_key));
+ new_key.objectid = inode->i_ino;
+ new_key.offset = key.offset + destoff - off;
+
+ if (type == BTRFS_FILE_EXTENT_REG) {
+ ret = btrfs_insert_empty_item(trans, root, path,
+ &new_key, size);
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ write_extent_buffer(leaf, buf,
+ btrfs_item_ptr_offset(leaf, slot),
+ size);
+
+ extent = btrfs_item_ptr(leaf, slot,
+ struct btrfs_file_extent_item);
+ printk(" orig disk %llu~%llu data %llu~%llu\n",
+ disko, diskl, datao, datal);
+
+ if (off > key.offset) {
+ datao += off - key.offset;
+ datal -= off - key.offset;
+ }
+ if (key.offset + datao + datal + key.offset >
+ off + len)
+ datal = off + len - key.offset - datao;
+ /* disko == 0 means it's a hole */
+ if (!disko)
+ datao = 0;
+ printk(" final disk %llu~%llu data %llu~%llu\n",
+ disko, diskl, datao, datal);
+
+ btrfs_set_file_extent_offset(leaf, extent,
+ datao);
+ btrfs_set_file_extent_num_bytes(leaf, extent,
+ datal);
+ if (disko) {
+ inode_add_bytes(inode, datal);
+ ret = btrfs_inc_extent_ref(trans, root,
+ disko, diskl, leaf->start,
+ root->root_key.objectid,
+ trans->transid,
+ inode->i_ino);
+ BUG_ON(ret);
+ }
+ } else if (type == BTRFS_FILE_EXTENT_INLINE) {
+ u64 skip = 0;
+ u64 trim = 0;
+ if (off > key.offset) {
+ skip = off - key.offset;
+ new_key.offset += skip;
+ }
+ if (key.offset + datal > off+len)
+ trim = key.offset + datal - (off+len);
+ printk("len %lld skip %lld trim %lld\n",
+ datal, skip, trim);
+ if (comp && (skip || trim)) {
+ printk("btrfs clone_range can't split compressed inline extents yet\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ size -= skip + trim;
+ datal -= skip + trim;
+ ret = btrfs_insert_empty_item(trans, root, path,
+ &new_key, size);
+ if (ret)
+ goto out;
+
+ if (skip) {
+ u32 start = btrfs_file_extent_calc_inline_size(0);
+ memmove(buf+start, buf+start+skip,
+ datal);
+ }
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ write_extent_buffer(leaf, buf,
+ btrfs_item_ptr_offset(leaf, slot),
+ size);
+ inode_add_bytes(inode, datal);
+ }
+
+ btrfs_mark_buffer_dirty(leaf);
+ }
+
+ if (btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY) {
+ u32 size;
+ struct btrfs_key new_key;
+ u64 coverslen;
+ int coff, clen;
+
+ size = btrfs_item_size_nr(leaf, slot);
+ coverslen = (size / BTRFS_CRC32_SIZE) <<
+ root->fs_info->sb->s_blocksize_bits;
+ printk("csums for %llu~%llu\n",
+ key.offset, coverslen);
+ if (key.offset + coverslen < off ||
+ key.offset >= off+len)
+ goto next;
+
+ read_extent_buffer(leaf, buf,
+ btrfs_item_ptr_offset(leaf, slot),
+ size);
+ btrfs_release_path(root, path);
+
+ coff = 0;
+ if (off > key.offset)
+ coff = ((off - key.offset) >>
+ root->fs_info->sb->s_blocksize_bits) *
+ BTRFS_CRC32_SIZE;
+ clen = size - coff;
+ if (key.offset + coverslen > off+len)
+ clen -= ((key.offset+coverslen-off-len) >>
+ root->fs_info->sb->s_blocksize_bits) *
+ BTRFS_CRC32_SIZE;
+ printk(" will dup %d~%d of %d\n",
+ coff, clen, size);
+
+ memcpy(&new_key, &key, sizeof(new_key));
+ new_key.objectid = inode->i_ino;
+ new_key.offset = key.offset + destoff - off;
+
+ ret = btrfs_insert_empty_item(trans, root, path,
+ &new_key, clen);
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ write_extent_buffer(leaf, buf + coff,
+ btrfs_item_ptr_offset(leaf, slot),
+ clen);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+
+ next:
+ btrfs_release_path(root, path);
+ key.offset++;
+ }
+ ret = 0;
+out:
+ btrfs_release_path(root, path);
+ if (ret == 0) {
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ if (destoff + olen > inode->i_size)
+ btrfs_i_size_write(inode, destoff + olen);
+ BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
+ ret = btrfs_update_inode(trans, root, inode);
+ }
+ btrfs_end_transaction(trans, root);
+ unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
+ if (ret)
+ vmtruncate(inode, 0);
+out_unlock:
+ mutex_unlock(&src->i_mutex);
+ mutex_unlock(&inode->i_mutex);
+ vfree(buf);
+ btrfs_free_path(path);
+out_fput:
+ fput(src_file);
+ return ret;
+}
+
+long btrfs_ioctl_clone_range(struct file *file, unsigned long argptr)
+{
+ struct btrfs_ioctl_clone_range_args args;
+
+ if (copy_from_user(&args, (void *)argptr, sizeof(args)))
+ return -EFAULT;
+ return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
+ args.src_length, args.dest_offset);
+}
+
+/*
+ * there are many ways the trans_start and trans_end ioctls can lead
+ * to deadlocks. They should only be used by applications that
+ * basically own the machine, and have a very in depth understanding
+ * of all the possible deadlocks and enospc problems.
+ */
+long btrfs_ioctl_trans_start(struct file *file)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (file->private_data) {
+ ret = -EINPROGRESS;
+ goto out;
+ }
+
+ ret = mnt_want_write(file->f_path.mnt);
+ if (ret)
+ goto out;
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ root->fs_info->open_ioctl_trans++;
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ trans = btrfs_start_ioctl_transaction(root, 0);
+ if (trans)
+ file->private_data = trans;
+ else
+ ret = -ENOMEM;
+ /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
+out:
+ return ret;
+}
+
+/*
+ * there are many ways the trans_start and trans_end ioctls can lead
+ * to deadlocks. They should only be used by applications that
+ * basically own the machine, and have a very in depth understanding
+ * of all the possible deadlocks and enospc problems.
+ */
+long btrfs_ioctl_trans_end(struct file *file)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+
+ trans = file->private_data;
+ if (!trans) {
+ ret = -EINVAL;
+ goto out;
+ }
+ btrfs_end_transaction(trans, root);
+ file->private_data = NULL;
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ root->fs_info->open_ioctl_trans--;
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+out:
+ return ret;
+}
+
+long btrfs_ioctl(struct file *file, unsigned int
+ cmd, unsigned long arg)
+{
+ struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
+
+ switch (cmd) {
+ case BTRFS_IOC_SNAP_CREATE:
+ return btrfs_ioctl_snap_create(file, (void __user *)arg, 0);
+ case BTRFS_IOC_SUBVOL_CREATE:
+ return btrfs_ioctl_snap_create(file, (void __user *)arg, 1);
+ case BTRFS_IOC_DEFRAG:
+ return btrfs_ioctl_defrag(file);
+ case BTRFS_IOC_RESIZE:
+ return btrfs_ioctl_resize(root, (void __user *)arg);
+ case BTRFS_IOC_ADD_DEV:
+ return btrfs_ioctl_add_dev(root, (void __user *)arg);
+ case BTRFS_IOC_RM_DEV:
+ return btrfs_ioctl_rm_dev(root, (void __user *)arg);
+ case BTRFS_IOC_BALANCE:
+ return btrfs_balance(root->fs_info->dev_root);
+ case BTRFS_IOC_CLONE:
+ return btrfs_ioctl_clone(file, arg, 0, 0, 0);
+ case BTRFS_IOC_CLONE_RANGE:
+ return btrfs_ioctl_clone_range(file, arg);
+ case BTRFS_IOC_TRANS_START:
+ return btrfs_ioctl_trans_start(file);
+ case BTRFS_IOC_TRANS_END:
+ return btrfs_ioctl_trans_end(file);
+ case BTRFS_IOC_SYNC:
+ btrfs_start_delalloc_inodes(root);
+ btrfs_sync_fs(file->f_dentry->d_sb, 1);
+ return 0;
+ }
+
+ return -ENOTTY;
+}
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
new file mode 100644
index 0000000..78049ea
--- /dev/null
+++ b/fs/btrfs/ioctl.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __IOCTL_
+#define __IOCTL_
+#include <linux/ioctl.h>
+
+#define BTRFS_IOCTL_MAGIC 0x94
+#define BTRFS_VOL_NAME_MAX 255
+#define BTRFS_PATH_NAME_MAX 3072
+
+struct btrfs_ioctl_vol_args {
+ __s64 fd;
+ char name[BTRFS_PATH_NAME_MAX + 1];
+};
+
+#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
+ struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
+ struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_RESIZE _IOW(BTRFS_IOCTL_MAGIC, 3, \
+ struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_SCAN_DEV _IOW(BTRFS_IOCTL_MAGIC, 4, \
+ struct btrfs_ioctl_vol_args)
+/* trans start and trans end are dangerous, and only for
+ * use by applications that know how to avoid the
+ * resulting deadlocks
+ */
+#define BTRFS_IOC_TRANS_START _IO(BTRFS_IOCTL_MAGIC, 6)
+#define BTRFS_IOC_TRANS_END _IO(BTRFS_IOCTL_MAGIC, 7)
+#define BTRFS_IOC_SYNC _IO(BTRFS_IOCTL_MAGIC, 8)
+
+#define BTRFS_IOC_CLONE _IOW(BTRFS_IOCTL_MAGIC, 9, int)
+#define BTRFS_IOC_ADD_DEV _IOW(BTRFS_IOCTL_MAGIC, 10, \
+ struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_RM_DEV _IOW(BTRFS_IOCTL_MAGIC, 11, \
+ struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_BALANCE _IOW(BTRFS_IOCTL_MAGIC, 12, \
+ struct btrfs_ioctl_vol_args)
+struct btrfs_ioctl_clone_range_args {
+ __s64 src_fd;
+ __u64 src_offset, src_length;
+ __u64 dest_offset;
+};
+
+#define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
+ struct btrfs_ioctl_clone_range_args)
+
+#define BTRFS_IOC_SUBVOL_CREATE _IOW(BTRFS_IOCTL_MAGIC, 14, \
+ struct btrfs_ioctl_vol_args)
+
+#endif
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
new file mode 100644
index 0000000..e30aa6e
--- /dev/null
+++ b/fs/btrfs/locking.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include <linux/pagemap.h>
+#include <linux/spinlock.h>
+#include <linux/page-flags.h>
+#include <asm/bug.h>
+#include "ctree.h"
+#include "extent_io.h"
+#include "locking.h"
+
+/*
+ * locks the per buffer mutex in an extent buffer. This uses adaptive locks
+ * and the spin is not tuned very extensively. The spinning does make a big
+ * difference in almost every workload, but spinning for the right amount of
+ * time needs some help.
+ *
+ * In general, we want to spin as long as the lock holder is doing btree searches,
+ * and we should give up if they are in more expensive code.
+ */
+int btrfs_tree_lock(struct extent_buffer *eb)
+{
+ int i;
+
+ if (mutex_trylock(&eb->mutex))
+ return 0;
+ for (i = 0; i < 512; i++) {
+ cpu_relax();
+ if (mutex_trylock(&eb->mutex))
+ return 0;
+ }
+ cpu_relax();
+ mutex_lock_nested(&eb->mutex, BTRFS_MAX_LEVEL - btrfs_header_level(eb));
+ return 0;
+}
+
+int btrfs_try_tree_lock(struct extent_buffer *eb)
+{
+ return mutex_trylock(&eb->mutex);
+}
+
+int btrfs_tree_unlock(struct extent_buffer *eb)
+{
+ mutex_unlock(&eb->mutex);
+ return 0;
+}
+
+int btrfs_tree_locked(struct extent_buffer *eb)
+{
+ return mutex_is_locked(&eb->mutex);
+}
+
+/*
+ * btrfs_search_slot uses this to decide if it should drop its locks
+ * before doing something expensive like allocating free blocks for cow.
+ */
+int btrfs_path_lock_waiting(struct btrfs_path *path, int level)
+{
+ int i;
+ struct extent_buffer *eb;
+ for (i = level; i <= level + 1 && i < BTRFS_MAX_LEVEL; i++) {
+ eb = path->nodes[i];
+ if (!eb)
+ break;
+ smp_mb();
+ if (!list_empty(&eb->mutex.wait_list))
+ return 1;
+ }
+ return 0;
+}
+
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
new file mode 100644
index 0000000..bc1faef
--- /dev/null
+++ b/fs/btrfs/locking.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_LOCKING_
+#define __BTRFS_LOCKING_
+
+int btrfs_tree_lock(struct extent_buffer *eb);
+int btrfs_tree_unlock(struct extent_buffer *eb);
+int btrfs_tree_locked(struct extent_buffer *eb);
+int btrfs_try_tree_lock(struct extent_buffer *eb);
+int btrfs_path_lock_waiting(struct btrfs_path *path, int level);
+#endif
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
new file mode 100644
index 0000000..027ad6b
--- /dev/null
+++ b/fs/btrfs/ordered-data.c
@@ -0,0 +1,733 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/writeback.h>
+#include <linux/pagevec.h>
+#include "ctree.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "extent_io.h"
+
+static u64 entry_end(struct btrfs_ordered_extent *entry)
+{
+ if (entry->file_offset + entry->len < entry->file_offset)
+ return (u64)-1;
+ return entry->file_offset + entry->len;
+}
+
+/* returns NULL if the insertion worked, or it returns the node it did find
+ * in the tree
+ */
+static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
+ struct rb_node *node)
+{
+ struct rb_node ** p = &root->rb_node;
+ struct rb_node * parent = NULL;
+ struct btrfs_ordered_extent *entry;
+
+ while(*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
+
+ if (file_offset < entry->file_offset)
+ p = &(*p)->rb_left;
+ else if (file_offset >= entry_end(entry))
+ p = &(*p)->rb_right;
+ else
+ return parent;
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+ return NULL;
+}
+
+/*
+ * look for a given offset in the tree, and if it can't be found return the
+ * first lesser offset
+ */
+static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
+ struct rb_node **prev_ret)
+{
+ struct rb_node * n = root->rb_node;
+ struct rb_node *prev = NULL;
+ struct rb_node *test;
+ struct btrfs_ordered_extent *entry;
+ struct btrfs_ordered_extent *prev_entry = NULL;
+
+ while(n) {
+ entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
+ prev = n;
+ prev_entry = entry;
+
+ if (file_offset < entry->file_offset)
+ n = n->rb_left;
+ else if (file_offset >= entry_end(entry))
+ n = n->rb_right;
+ else
+ return n;
+ }
+ if (!prev_ret)
+ return NULL;
+
+ while(prev && file_offset >= entry_end(prev_entry)) {
+ test = rb_next(prev);
+ if (!test)
+ break;
+ prev_entry = rb_entry(test, struct btrfs_ordered_extent,
+ rb_node);
+ if (file_offset < entry_end(prev_entry))
+ break;
+
+ prev = test;
+ }
+ if (prev)
+ prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
+ rb_node);
+ while(prev && file_offset < entry_end(prev_entry)) {
+ test = rb_prev(prev);
+ if (!test)
+ break;
+ prev_entry = rb_entry(test, struct btrfs_ordered_extent,
+ rb_node);
+ prev = test;
+ }
+ *prev_ret = prev;
+ return NULL;
+}
+
+/*
+ * helper to check if a given offset is inside a given entry
+ */
+static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
+{
+ if (file_offset < entry->file_offset ||
+ entry->file_offset + entry->len <= file_offset)
+ return 0;
+ return 1;
+}
+
+/*
+ * look find the first ordered struct that has this offset, otherwise
+ * the first one less than this offset
+ */
+static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
+ u64 file_offset)
+{
+ struct rb_root *root = &tree->tree;
+ struct rb_node *prev;
+ struct rb_node *ret;
+ struct btrfs_ordered_extent *entry;
+
+ if (tree->last) {
+ entry = rb_entry(tree->last, struct btrfs_ordered_extent,
+ rb_node);
+ if (offset_in_entry(entry, file_offset))
+ return tree->last;
+ }
+ ret = __tree_search(root, file_offset, &prev);
+ if (!ret)
+ ret = prev;
+ if (ret)
+ tree->last = ret;
+ return ret;
+}
+
+/* allocate and add a new ordered_extent into the per-inode tree.
+ * file_offset is the logical offset in the file
+ *
+ * start is the disk block number of an extent already reserved in the
+ * extent allocation tree
+ *
+ * len is the length of the extent
+ *
+ * This also sets the EXTENT_ORDERED bit on the range in the inode.
+ *
+ * The tree is given a single reference on the ordered extent that was
+ * inserted.
+ */
+int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len, int type)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ entry = kzalloc(sizeof(*entry), GFP_NOFS);
+ if (!entry)
+ return -ENOMEM;
+
+ mutex_lock(&tree->mutex);
+ entry->file_offset = file_offset;
+ entry->start = start;
+ entry->len = len;
+ entry->disk_len = disk_len;
+ entry->inode = inode;
+ if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
+ set_bit(type, &entry->flags);
+
+ /* one ref for the tree */
+ atomic_set(&entry->refs, 1);
+ init_waitqueue_head(&entry->wait);
+ INIT_LIST_HEAD(&entry->list);
+ INIT_LIST_HEAD(&entry->root_extent_list);
+
+ node = tree_insert(&tree->tree, file_offset,
+ &entry->rb_node);
+ if (node) {
+ printk("warning dup entry from add_ordered_extent\n");
+ BUG();
+ }
+ set_extent_ordered(&BTRFS_I(inode)->io_tree, file_offset,
+ entry_end(entry) - 1, GFP_NOFS);
+
+ spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
+ list_add_tail(&entry->root_extent_list,
+ &BTRFS_I(inode)->root->fs_info->ordered_extents);
+ spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
+
+ mutex_unlock(&tree->mutex);
+ BUG_ON(node);
+ return 0;
+}
+
+/*
+ * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
+ * when an ordered extent is finished. If the list covers more than one
+ * ordered extent, it is split across multiples.
+ */
+int btrfs_add_ordered_sum(struct inode *inode,
+ struct btrfs_ordered_extent *entry,
+ struct btrfs_ordered_sum *sum)
+{
+ struct btrfs_ordered_inode_tree *tree;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ mutex_lock(&tree->mutex);
+ list_add_tail(&sum->list, &entry->list);
+ mutex_unlock(&tree->mutex);
+ return 0;
+}
+
+/*
+ * this is used to account for finished IO across a given range
+ * of the file. The IO should not span ordered extents. If
+ * a given ordered_extent is completely done, 1 is returned, otherwise
+ * 0.
+ *
+ * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
+ * to make sure this function only returns 1 once for a given ordered extent.
+ */
+int btrfs_dec_test_ordered_pending(struct inode *inode,
+ u64 file_offset, u64 io_size)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ int ret;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ mutex_lock(&tree->mutex);
+ clear_extent_ordered(io_tree, file_offset, file_offset + io_size - 1,
+ GFP_NOFS);
+ node = tree_search(tree, file_offset);
+ if (!node) {
+ ret = 1;
+ goto out;
+ }
+
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (!offset_in_entry(entry, file_offset)) {
+ ret = 1;
+ goto out;
+ }
+
+ ret = test_range_bit(io_tree, entry->file_offset,
+ entry->file_offset + entry->len - 1,
+ EXTENT_ORDERED, 0);
+ if (ret == 0)
+ ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
+out:
+ mutex_unlock(&tree->mutex);
+ return ret == 0;
+}
+
+/*
+ * used to drop a reference on an ordered extent. This will free
+ * the extent if the last reference is dropped
+ */
+int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
+{
+ struct list_head *cur;
+ struct btrfs_ordered_sum *sum;
+
+ if (atomic_dec_and_test(&entry->refs)) {
+ while(!list_empty(&entry->list)) {
+ cur = entry->list.next;
+ sum = list_entry(cur, struct btrfs_ordered_sum, list);
+ list_del(&sum->list);
+ kfree(sum);
+ }
+ kfree(entry);
+ }
+ return 0;
+}
+
+/*
+ * remove an ordered extent from the tree. No references are dropped
+ * but, anyone waiting on this extent is woken up.
+ */
+int btrfs_remove_ordered_extent(struct inode *inode,
+ struct btrfs_ordered_extent *entry)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ mutex_lock(&tree->mutex);
+ node = &entry->rb_node;
+ rb_erase(node, &tree->tree);
+ tree->last = NULL;
+ set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
+
+ spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
+ list_del_init(&entry->root_extent_list);
+ spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
+
+ mutex_unlock(&tree->mutex);
+ wake_up(&entry->wait);
+ return 0;
+}
+
+/*
+ * wait for all the ordered extents in a root. This is done when balancing
+ * space between drives.
+ */
+int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only)
+{
+ struct list_head splice;
+ struct list_head *cur;
+ struct btrfs_ordered_extent *ordered;
+ struct inode *inode;
+
+ INIT_LIST_HEAD(&splice);
+
+ spin_lock(&root->fs_info->ordered_extent_lock);
+ list_splice_init(&root->fs_info->ordered_extents, &splice);
+ while (!list_empty(&splice)) {
+ cur = splice.next;
+ ordered = list_entry(cur, struct btrfs_ordered_extent,
+ root_extent_list);
+ if (nocow_only &&
+ !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
+ !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
+ list_move(&ordered->root_extent_list,
+ &root->fs_info->ordered_extents);
+ cond_resched_lock(&root->fs_info->ordered_extent_lock);
+ continue;
+ }
+
+ list_del_init(&ordered->root_extent_list);
+ atomic_inc(&ordered->refs);
+
+ /*
+ * the inode may be getting freed (in sys_unlink path).
+ */
+ inode = igrab(ordered->inode);
+
+ spin_unlock(&root->fs_info->ordered_extent_lock);
+
+ if (inode) {
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ iput(inode);
+ } else {
+ btrfs_put_ordered_extent(ordered);
+ }
+
+ spin_lock(&root->fs_info->ordered_extent_lock);
+ }
+ spin_unlock(&root->fs_info->ordered_extent_lock);
+ return 0;
+}
+
+/*
+ * Used to start IO or wait for a given ordered extent to finish.
+ *
+ * If wait is one, this effectively waits on page writeback for all the pages
+ * in the extent, and it waits on the io completion code to insert
+ * metadata into the btree corresponding to the extent
+ */
+void btrfs_start_ordered_extent(struct inode *inode,
+ struct btrfs_ordered_extent *entry,
+ int wait)
+{
+ u64 start = entry->file_offset;
+ u64 end = start + entry->len - 1;
+
+ /*
+ * pages in the range can be dirty, clean or writeback. We
+ * start IO on any dirty ones so the wait doesn't stall waiting
+ * for pdflush to find them
+ */
+ btrfs_fdatawrite_range(inode->i_mapping, start, end, WB_SYNC_ALL);
+ if (wait) {
+ wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
+ &entry->flags));
+ }
+}
+
+/*
+ * Used to wait on ordered extents across a large range of bytes.
+ */
+int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
+{
+ u64 end;
+ u64 orig_end;
+ u64 wait_end;
+ struct btrfs_ordered_extent *ordered;
+
+ if (start + len < start) {
+ orig_end = INT_LIMIT(loff_t);
+ } else {
+ orig_end = start + len - 1;
+ if (orig_end > INT_LIMIT(loff_t))
+ orig_end = INT_LIMIT(loff_t);
+ }
+ wait_end = orig_end;
+again:
+ /* start IO across the range first to instantiate any delalloc
+ * extents
+ */
+ btrfs_fdatawrite_range(inode->i_mapping, start, orig_end, WB_SYNC_NONE);
+
+ /* The compression code will leave pages locked but return from
+ * writepage without setting the page writeback. Starting again
+ * with WB_SYNC_ALL will end up waiting for the IO to actually start.
+ */
+ btrfs_fdatawrite_range(inode->i_mapping, start, orig_end, WB_SYNC_ALL);
+
+ btrfs_wait_on_page_writeback_range(inode->i_mapping,
+ start >> PAGE_CACHE_SHIFT,
+ orig_end >> PAGE_CACHE_SHIFT);
+
+ end = orig_end;
+ while(1) {
+ ordered = btrfs_lookup_first_ordered_extent(inode, end);
+ if (!ordered) {
+ break;
+ }
+ if (ordered->file_offset > orig_end) {
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ if (ordered->file_offset + ordered->len < start) {
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ end = ordered->file_offset;
+ btrfs_put_ordered_extent(ordered);
+ if (end == 0 || end == start)
+ break;
+ end--;
+ }
+ if (test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
+ EXTENT_ORDERED | EXTENT_DELALLOC, 0)) {
+ schedule_timeout(1);
+ goto again;
+ }
+ return 0;
+}
+
+/*
+ * find an ordered extent corresponding to file_offset. return NULL if
+ * nothing is found, otherwise take a reference on the extent and return it
+ */
+struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
+ u64 file_offset)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ mutex_lock(&tree->mutex);
+ node = tree_search(tree, file_offset);
+ if (!node)
+ goto out;
+
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (!offset_in_entry(entry, file_offset))
+ entry = NULL;
+ if (entry)
+ atomic_inc(&entry->refs);
+out:
+ mutex_unlock(&tree->mutex);
+ return entry;
+}
+
+/*
+ * lookup and return any extent before 'file_offset'. NULL is returned
+ * if none is found
+ */
+struct btrfs_ordered_extent *
+btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ mutex_lock(&tree->mutex);
+ node = tree_search(tree, file_offset);
+ if (!node)
+ goto out;
+
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ atomic_inc(&entry->refs);
+out:
+ mutex_unlock(&tree->mutex);
+ return entry;
+}
+
+/*
+ * After an extent is done, call this to conditionally update the on disk
+ * i_size. i_size is updated to cover any fully written part of the file.
+ */
+int btrfs_ordered_update_i_size(struct inode *inode,
+ struct btrfs_ordered_extent *ordered)
+{
+ struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ u64 disk_i_size;
+ u64 new_i_size;
+ u64 i_size_test;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *test;
+
+ mutex_lock(&tree->mutex);
+ disk_i_size = BTRFS_I(inode)->disk_i_size;
+
+ /*
+ * if the disk i_size is already at the inode->i_size, or
+ * this ordered extent is inside the disk i_size, we're done
+ */
+ if (disk_i_size >= inode->i_size ||
+ ordered->file_offset + ordered->len <= disk_i_size) {
+ goto out;
+ }
+
+ /*
+ * we can't update the disk_isize if there are delalloc bytes
+ * between disk_i_size and this ordered extent
+ */
+ if (test_range_bit(io_tree, disk_i_size,
+ ordered->file_offset + ordered->len - 1,
+ EXTENT_DELALLOC, 0)) {
+ goto out;
+ }
+ /*
+ * walk backward from this ordered extent to disk_i_size.
+ * if we find an ordered extent then we can't update disk i_size
+ * yet
+ */
+ node = &ordered->rb_node;
+ while(1) {
+ node = rb_prev(node);
+ if (!node)
+ break;
+ test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (test->file_offset + test->len <= disk_i_size)
+ break;
+ if (test->file_offset >= inode->i_size)
+ break;
+ if (test->file_offset >= disk_i_size)
+ goto out;
+ }
+ new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode));
+
+ /*
+ * at this point, we know we can safely update i_size to at least
+ * the offset from this ordered extent. But, we need to
+ * walk forward and see if ios from higher up in the file have
+ * finished.
+ */
+ node = rb_next(&ordered->rb_node);
+ i_size_test = 0;
+ if (node) {
+ /*
+ * do we have an area where IO might have finished
+ * between our ordered extent and the next one.
+ */
+ test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (test->file_offset > entry_end(ordered)) {
+ i_size_test = test->file_offset;
+ }
+ } else {
+ i_size_test = i_size_read(inode);
+ }
+
+ /*
+ * i_size_test is the end of a region after this ordered
+ * extent where there are no ordered extents. As long as there
+ * are no delalloc bytes in this area, it is safe to update
+ * disk_i_size to the end of the region.
+ */
+ if (i_size_test > entry_end(ordered) &&
+ !test_range_bit(io_tree, entry_end(ordered), i_size_test - 1,
+ EXTENT_DELALLOC, 0)) {
+ new_i_size = min_t(u64, i_size_test, i_size_read(inode));
+ }
+ BTRFS_I(inode)->disk_i_size = new_i_size;
+out:
+ mutex_unlock(&tree->mutex);
+ return 0;
+}
+
+/*
+ * search the ordered extents for one corresponding to 'offset' and
+ * try to find a checksum. This is used because we allow pages to
+ * be reclaimed before their checksum is actually put into the btree
+ */
+int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum)
+{
+ struct btrfs_ordered_sum *ordered_sum;
+ struct btrfs_sector_sum *sector_sums;
+ struct btrfs_ordered_extent *ordered;
+ struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
+ struct list_head *cur;
+ unsigned long num_sectors;
+ unsigned long i;
+ u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
+ int ret = 1;
+
+ ordered = btrfs_lookup_ordered_extent(inode, offset);
+ if (!ordered)
+ return 1;
+
+ mutex_lock(&tree->mutex);
+ list_for_each_prev(cur, &ordered->list) {
+ ordered_sum = list_entry(cur, struct btrfs_ordered_sum, list);
+ if (offset >= ordered_sum->file_offset) {
+ num_sectors = ordered_sum->len / sectorsize;
+ sector_sums = ordered_sum->sums;
+ for (i = 0; i < num_sectors; i++) {
+ if (sector_sums[i].offset == offset) {
+ *sum = sector_sums[i].sum;
+ ret = 0;
+ goto out;
+ }
+ }
+ }
+ }
+out:
+ mutex_unlock(&tree->mutex);
+ btrfs_put_ordered_extent(ordered);
+ return ret;
+}
+
+
+/**
+ * taken from mm/filemap.c because it isn't exported
+ *
+ * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
+ * @mapping: address space structure to write
+ * @start: offset in bytes where the range starts
+ * @end: offset in bytes where the range ends (inclusive)
+ * @sync_mode: enable synchronous operation
+ *
+ * Start writeback against all of a mapping's dirty pages that lie
+ * within the byte offsets <start, end> inclusive.
+ *
+ * If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
+ * opposed to a regular memory cleansing writeback. The difference between
+ * these two operations is that if a dirty page/buffer is encountered, it must
+ * be waited upon, and not just skipped over.
+ */
+int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end, int sync_mode)
+{
+ struct writeback_control wbc = {
+ .sync_mode = sync_mode,
+ .nr_to_write = mapping->nrpages * 2,
+ .range_start = start,
+ .range_end = end,
+ .for_writepages = 1,
+ };
+ return btrfs_writepages(mapping, &wbc);
+}
+
+/**
+ * taken from mm/filemap.c because it isn't exported
+ *
+ * wait_on_page_writeback_range - wait for writeback to complete
+ * @mapping: target address_space
+ * @start: beginning page index
+ * @end: ending page index
+ *
+ * Wait for writeback to complete against pages indexed by start->end
+ * inclusive
+ */
+int btrfs_wait_on_page_writeback_range(struct address_space *mapping,
+ pgoff_t start, pgoff_t end)
+{
+ struct pagevec pvec;
+ int nr_pages;
+ int ret = 0;
+ pgoff_t index;
+
+ if (end < start)
+ return 0;
+
+ pagevec_init(&pvec, 0);
+ index = start;
+ while ((index <= end) &&
+ (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+ PAGECACHE_TAG_WRITEBACK,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1)) != 0) {
+ unsigned i;
+
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pvec.pages[i];
+
+ /* until radix tree lookup accepts end_index */
+ if (page->index > end)
+ continue;
+
+ wait_on_page_writeback(page);
+ if (PageError(page))
+ ret = -EIO;
+ }
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+
+ /* Check for outstanding write errors */
+ if (test_and_clear_bit(AS_ENOSPC, &mapping->flags))
+ ret = -ENOSPC;
+ if (test_and_clear_bit(AS_EIO, &mapping->flags))
+ ret = -EIO;
+
+ return ret;
+}
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
new file mode 100644
index 0000000..260bf95
--- /dev/null
+++ b/fs/btrfs/ordered-data.h
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_ORDERED_DATA__
+#define __BTRFS_ORDERED_DATA__
+
+/* one of these per inode */
+struct btrfs_ordered_inode_tree {
+ struct mutex mutex;
+ struct rb_root tree;
+ struct rb_node *last;
+};
+
+/*
+ * these are used to collect checksums done just before bios submission.
+ * They are attached via a list into the ordered extent, and
+ * checksum items are inserted into the tree after all the blocks in
+ * the ordered extent are on disk
+ */
+struct btrfs_sector_sum {
+ u64 offset;
+ u32 sum;
+};
+
+struct btrfs_ordered_sum {
+ u64 file_offset;
+ /*
+ * this is the length in bytes covered by the sums array below.
+ * But, the sums array may not be contiguous in the file.
+ */
+ unsigned long len;
+ struct list_head list;
+ /* last field is a variable length array of btrfs_sector_sums */
+ struct btrfs_sector_sum sums[];
+};
+
+/*
+ * bits for the flags field:
+ *
+ * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
+ * It is used to make sure metadata is inserted into the tree only once
+ * per extent.
+ *
+ * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
+ * rbtree, just before waking any waiters. It is used to indicate the
+ * IO is done and any metadata is inserted into the tree.
+ */
+#define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
+
+#define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
+
+#define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
+
+#define BTRFS_ORDERED_COMPRESSED 3 /* writing a compressed extent */
+
+#define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */
+
+struct btrfs_ordered_extent {
+ /* logical offset in the file */
+ u64 file_offset;
+
+ /* disk byte number */
+ u64 start;
+
+ /* ram length of the extent in bytes */
+ u64 len;
+
+ /* extent length on disk */
+ u64 disk_len;
+
+ /* flags (described above) */
+ unsigned long flags;
+
+ /* reference count */
+ atomic_t refs;
+
+ /* the inode we belong to */
+ struct inode *inode;
+
+ /* list of checksums for insertion when the extent io is done */
+ struct list_head list;
+
+ /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
+ wait_queue_head_t wait;
+
+ /* our friendly rbtree entry */
+ struct rb_node rb_node;
+
+ /* a per root list of all the pending ordered extents */
+ struct list_head root_extent_list;
+};
+
+
+/*
+ * calculates the total size you need to allocate for an ordered sum
+ * structure spanning 'bytes' in the file
+ */
+static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
+ unsigned long bytes)
+{
+ unsigned long num_sectors = (bytes + root->sectorsize - 1) /
+ root->sectorsize;
+ num_sectors++;
+ return sizeof(struct btrfs_ordered_sum) +
+ num_sectors * sizeof(struct btrfs_sector_sum);
+}
+
+static inline void
+btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
+{
+ mutex_init(&t->mutex);
+ t->tree.rb_node = NULL;
+ t->last = NULL;
+}
+
+int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
+int btrfs_remove_ordered_extent(struct inode *inode,
+ struct btrfs_ordered_extent *entry);
+int btrfs_dec_test_ordered_pending(struct inode *inode,
+ u64 file_offset, u64 io_size);
+int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len, int tyep);
+int btrfs_add_ordered_sum(struct inode *inode,
+ struct btrfs_ordered_extent *entry,
+ struct btrfs_ordered_sum *sum);
+struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
+ u64 file_offset);
+void btrfs_start_ordered_extent(struct inode *inode,
+ struct btrfs_ordered_extent *entry, int wait);
+int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
+struct btrfs_ordered_extent *
+btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
+int btrfs_ordered_update_i_size(struct inode *inode,
+ struct btrfs_ordered_extent *ordered);
+int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum);
+int btrfs_wait_on_page_writeback_range(struct address_space *mapping,
+ pgoff_t start, pgoff_t end);
+int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end, int sync_mode);
+int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
+#endif
diff --git a/fs/btrfs/orphan.c b/fs/btrfs/orphan.c
new file mode 100644
index 0000000..3c0d52a
--- /dev/null
+++ b/fs/btrfs/orphan.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2008 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+
+int btrfs_insert_orphan_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 offset)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ int ret = 0;
+
+ key.objectid = BTRFS_ORPHAN_OBJECTID;
+ btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
+ key.offset = offset;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_del_orphan_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 offset)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ int ret = 0;
+
+ key.objectid = BTRFS_ORPHAN_OBJECTID;
+ btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
+ key.offset = offset;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret)
+ goto out;
+
+ ret = btrfs_del_item(trans, root, path);
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
new file mode 100644
index 0000000..64725c1
--- /dev/null
+++ b/fs/btrfs/print-tree.c
@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "print-tree.h"
+
+static void print_chunk(struct extent_buffer *eb, struct btrfs_chunk *chunk)
+{
+ int num_stripes = btrfs_chunk_num_stripes(eb, chunk);
+ int i;
+ printk("\t\tchunk length %llu owner %llu type %llu num_stripes %d\n",
+ (unsigned long long)btrfs_chunk_length(eb, chunk),
+ (unsigned long long)btrfs_chunk_owner(eb, chunk),
+ (unsigned long long)btrfs_chunk_type(eb, chunk),
+ num_stripes);
+ for (i = 0 ; i < num_stripes ; i++) {
+ printk("\t\t\tstripe %d devid %llu offset %llu\n", i,
+ (unsigned long long)btrfs_stripe_devid_nr(eb, chunk, i),
+ (unsigned long long)btrfs_stripe_offset_nr(eb, chunk, i));
+ }
+}
+static void print_dev_item(struct extent_buffer *eb,
+ struct btrfs_dev_item *dev_item)
+{
+ printk("\t\tdev item devid %llu "
+ "total_bytes %llu bytes used %Lu\n",
+ (unsigned long long)btrfs_device_id(eb, dev_item),
+ (unsigned long long)btrfs_device_total_bytes(eb, dev_item),
+ (unsigned long long)btrfs_device_bytes_used(eb, dev_item));
+}
+void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
+{
+ int i;
+ u32 nr = btrfs_header_nritems(l);
+ struct btrfs_item *item;
+ struct btrfs_extent_item *ei;
+ struct btrfs_root_item *ri;
+ struct btrfs_dir_item *di;
+ struct btrfs_inode_item *ii;
+ struct btrfs_block_group_item *bi;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_extent_ref *ref;
+ struct btrfs_dev_extent *dev_extent;
+ u32 type;
+
+ printk("leaf %llu total ptrs %d free space %d\n",
+ (unsigned long long)btrfs_header_bytenr(l), nr,
+ btrfs_leaf_free_space(root, l));
+ for (i = 0 ; i < nr ; i++) {
+ item = btrfs_item_nr(l, i);
+ btrfs_item_key_to_cpu(l, &key, i);
+ type = btrfs_key_type(&key);
+ printk("\titem %d key (%llu %x %llu) itemoff %d itemsize %d\n",
+ i,
+ (unsigned long long)key.objectid, type,
+ (unsigned long long)key.offset,
+ btrfs_item_offset(l, item), btrfs_item_size(l, item));
+ switch (type) {
+ case BTRFS_INODE_ITEM_KEY:
+ ii = btrfs_item_ptr(l, i, struct btrfs_inode_item);
+ printk("\t\tinode generation %llu size %llu mode %o\n",
+ (unsigned long long)btrfs_inode_generation(l, ii),
+ (unsigned long long)btrfs_inode_size(l, ii),
+ btrfs_inode_mode(l, ii));
+ break;
+ case BTRFS_DIR_ITEM_KEY:
+ di = btrfs_item_ptr(l, i, struct btrfs_dir_item);
+ btrfs_dir_item_key_to_cpu(l, di, &found_key);
+ printk("\t\tdir oid %llu type %u\n",
+ (unsigned long long)found_key.objectid,
+ btrfs_dir_type(l, di));
+ break;
+ case BTRFS_ROOT_ITEM_KEY:
+ ri = btrfs_item_ptr(l, i, struct btrfs_root_item);
+ printk("\t\troot data bytenr %llu refs %u\n",
+ (unsigned long long)btrfs_disk_root_bytenr(l, ri),
+ btrfs_disk_root_refs(l, ri));
+ break;
+ case BTRFS_EXTENT_ITEM_KEY:
+ ei = btrfs_item_ptr(l, i, struct btrfs_extent_item);
+ printk("\t\textent data refs %u\n",
+ btrfs_extent_refs(l, ei));
+ break;
+ case BTRFS_EXTENT_REF_KEY:
+ ref = btrfs_item_ptr(l, i, struct btrfs_extent_ref);
+ printk("\t\textent back ref root %llu gen %llu "
+ "owner %llu num_refs %lu\n",
+ (unsigned long long)btrfs_ref_root(l, ref),
+ (unsigned long long)btrfs_ref_generation(l, ref),
+ (unsigned long long)btrfs_ref_objectid(l, ref),
+ (unsigned long)btrfs_ref_num_refs(l, ref));
+ break;
+
+ case BTRFS_EXTENT_DATA_KEY:
+ fi = btrfs_item_ptr(l, i,
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(l, fi) ==
+ BTRFS_FILE_EXTENT_INLINE) {
+ printk("\t\tinline extent data size %u\n",
+ btrfs_file_extent_inline_len(l, fi));
+ break;
+ }
+ printk("\t\textent data disk bytenr %llu nr %llu\n",
+ (unsigned long long)btrfs_file_extent_disk_bytenr(l, fi),
+ (unsigned long long)btrfs_file_extent_disk_num_bytes(l, fi));
+ printk("\t\textent data offset %llu nr %llu ram %llu\n",
+ (unsigned long long)btrfs_file_extent_offset(l, fi),
+ (unsigned long long)btrfs_file_extent_num_bytes(l, fi),
+ (unsigned long long)btrfs_file_extent_ram_bytes(l, fi));
+ break;
+ case BTRFS_BLOCK_GROUP_ITEM_KEY:
+ bi = btrfs_item_ptr(l, i,
+ struct btrfs_block_group_item);
+ printk("\t\tblock group used %llu\n",
+ (unsigned long long)btrfs_disk_block_group_used(l, bi));
+ break;
+ case BTRFS_CHUNK_ITEM_KEY:
+ print_chunk(l, btrfs_item_ptr(l, i, struct btrfs_chunk));
+ break;
+ case BTRFS_DEV_ITEM_KEY:
+ print_dev_item(l, btrfs_item_ptr(l, i,
+ struct btrfs_dev_item));
+ break;
+ case BTRFS_DEV_EXTENT_KEY:
+ dev_extent = btrfs_item_ptr(l, i,
+ struct btrfs_dev_extent);
+ printk("\t\tdev extent chunk_tree %llu\n"
+ "\t\tchunk objectid %llu chunk offset %llu "
+ "length %llu\n",
+ (unsigned long long)
+ btrfs_dev_extent_chunk_tree(l, dev_extent),
+ (unsigned long long)
+ btrfs_dev_extent_chunk_objectid(l, dev_extent),
+ (unsigned long long)
+ btrfs_dev_extent_chunk_offset(l, dev_extent),
+ (unsigned long long)
+ btrfs_dev_extent_length(l, dev_extent));
+ };
+ }
+}
+
+void btrfs_print_tree(struct btrfs_root *root, struct extent_buffer *c)
+{
+ int i; u32 nr;
+ struct btrfs_key key;
+ int level;
+
+ if (!c)
+ return;
+ nr = btrfs_header_nritems(c);
+ level = btrfs_header_level(c);
+ if (level == 0) {
+ btrfs_print_leaf(root, c);
+ return;
+ }
+ printk("node %llu level %d total ptrs %d free spc %u\n",
+ (unsigned long long)btrfs_header_bytenr(c),
+ btrfs_header_level(c), nr,
+ (u32)BTRFS_NODEPTRS_PER_BLOCK(root) - nr);
+ for (i = 0; i < nr; i++) {
+ btrfs_node_key_to_cpu(c, &key, i);
+ printk("\tkey %d (%llu %u %llu) block %llu\n",
+ i,
+ (unsigned long long)key.objectid,
+ key.type,
+ (unsigned long long)key.offset,
+ (unsigned long long)btrfs_node_blockptr(c, i));
+ }
+ for (i = 0; i < nr; i++) {
+ struct extent_buffer *next = read_tree_block(root,
+ btrfs_node_blockptr(c, i),
+ btrfs_level_size(root, level - 1),
+ btrfs_node_ptr_generation(c, i));
+ if (btrfs_is_leaf(next) &&
+ btrfs_header_level(c) != 1)
+ BUG();
+ if (btrfs_header_level(next) !=
+ btrfs_header_level(c) - 1)
+ BUG();
+ btrfs_print_tree(root, next);
+ free_extent_buffer(next);
+ }
+}
diff --git a/fs/btrfs/print-tree.h b/fs/btrfs/print-tree.h
new file mode 100644
index 0000000..da75efe
--- /dev/null
+++ b/fs/btrfs/print-tree.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __PRINT_TREE_
+#define __PRINT_TREE_
+void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l);
+void btrfs_print_tree(struct btrfs_root *root, struct extent_buffer *t);
+#endif
diff --git a/fs/btrfs/ref-cache.c b/fs/btrfs/ref-cache.c
new file mode 100644
index 0000000..a50ebb6
--- /dev/null
+++ b/fs/btrfs/ref-cache.c
@@ -0,0 +1,230 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include "ctree.h"
+#include "ref-cache.h"
+#include "transaction.h"
+
+/*
+ * leaf refs are used to cache the information about which extents
+ * a given leaf has references on. This allows us to process that leaf
+ * in btrfs_drop_snapshot without needing to read it back from disk.
+ */
+
+/*
+ * kmalloc a leaf reference struct and update the counters for the
+ * total ref cache size
+ */
+struct btrfs_leaf_ref *btrfs_alloc_leaf_ref(struct btrfs_root *root,
+ int nr_extents)
+{
+ struct btrfs_leaf_ref *ref;
+ size_t size = btrfs_leaf_ref_size(nr_extents);
+
+ ref = kmalloc(size, GFP_NOFS);
+ if (ref) {
+ spin_lock(&root->fs_info->ref_cache_lock);
+ root->fs_info->total_ref_cache_size += size;
+ spin_unlock(&root->fs_info->ref_cache_lock);
+
+ memset(ref, 0, sizeof(*ref));
+ atomic_set(&ref->usage, 1);
+ INIT_LIST_HEAD(&ref->list);
+ }
+ return ref;
+}
+
+/*
+ * free a leaf reference struct and update the counters for the
+ * total ref cache size
+ */
+void btrfs_free_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref)
+{
+ if (!ref)
+ return;
+ WARN_ON(atomic_read(&ref->usage) == 0);
+ if (atomic_dec_and_test(&ref->usage)) {
+ size_t size = btrfs_leaf_ref_size(ref->nritems);
+
+ BUG_ON(ref->in_tree);
+ kfree(ref);
+
+ spin_lock(&root->fs_info->ref_cache_lock);
+ root->fs_info->total_ref_cache_size -= size;
+ spin_unlock(&root->fs_info->ref_cache_lock);
+ }
+}
+
+static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
+ struct rb_node *node)
+{
+ struct rb_node ** p = &root->rb_node;
+ struct rb_node * parent = NULL;
+ struct btrfs_leaf_ref *entry;
+
+ while(*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct btrfs_leaf_ref, rb_node);
+
+ if (bytenr < entry->bytenr)
+ p = &(*p)->rb_left;
+ else if (bytenr > entry->bytenr)
+ p = &(*p)->rb_right;
+ else
+ return parent;
+ }
+
+ entry = rb_entry(node, struct btrfs_leaf_ref, rb_node);
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+ return NULL;
+}
+
+static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
+{
+ struct rb_node * n = root->rb_node;
+ struct btrfs_leaf_ref *entry;
+
+ while(n) {
+ entry = rb_entry(n, struct btrfs_leaf_ref, rb_node);
+ WARN_ON(!entry->in_tree);
+
+ if (bytenr < entry->bytenr)
+ n = n->rb_left;
+ else if (bytenr > entry->bytenr)
+ n = n->rb_right;
+ else
+ return n;
+ }
+ return NULL;
+}
+
+int btrfs_remove_leaf_refs(struct btrfs_root *root, u64 max_root_gen,
+ int shared)
+{
+ struct btrfs_leaf_ref *ref = NULL;
+ struct btrfs_leaf_ref_tree *tree = root->ref_tree;
+
+ if (shared)
+ tree = &root->fs_info->shared_ref_tree;
+ if (!tree)
+ return 0;
+
+ spin_lock(&tree->lock);
+ while(!list_empty(&tree->list)) {
+ ref = list_entry(tree->list.next, struct btrfs_leaf_ref, list);
+ BUG_ON(ref->tree != tree);
+ if (ref->root_gen > max_root_gen)
+ break;
+ if (!xchg(&ref->in_tree, 0)) {
+ cond_resched_lock(&tree->lock);
+ continue;
+ }
+
+ rb_erase(&ref->rb_node, &tree->root);
+ list_del_init(&ref->list);
+
+ spin_unlock(&tree->lock);
+ btrfs_free_leaf_ref(root, ref);
+ cond_resched();
+ spin_lock(&tree->lock);
+ }
+ spin_unlock(&tree->lock);
+ return 0;
+}
+
+/*
+ * find the leaf ref for a given extent. This returns the ref struct with
+ * a usage reference incremented
+ */
+struct btrfs_leaf_ref *btrfs_lookup_leaf_ref(struct btrfs_root *root,
+ u64 bytenr)
+{
+ struct rb_node *rb;
+ struct btrfs_leaf_ref *ref = NULL;
+ struct btrfs_leaf_ref_tree *tree = root->ref_tree;
+again:
+ if (tree) {
+ spin_lock(&tree->lock);
+ rb = tree_search(&tree->root, bytenr);
+ if (rb)
+ ref = rb_entry(rb, struct btrfs_leaf_ref, rb_node);
+ if (ref)
+ atomic_inc(&ref->usage);
+ spin_unlock(&tree->lock);
+ if (ref)
+ return ref;
+ }
+ if (tree != &root->fs_info->shared_ref_tree) {
+ tree = &root->fs_info->shared_ref_tree;
+ goto again;
+ }
+ return NULL;
+}
+
+/*
+ * add a fully filled in leaf ref struct
+ * remove all the refs older than a given root generation
+ */
+int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref,
+ int shared)
+{
+ int ret = 0;
+ struct rb_node *rb;
+ struct btrfs_leaf_ref_tree *tree = root->ref_tree;
+
+ if (shared)
+ tree = &root->fs_info->shared_ref_tree;
+
+ spin_lock(&tree->lock);
+ rb = tree_insert(&tree->root, ref->bytenr, &ref->rb_node);
+ if (rb) {
+ ret = -EEXIST;
+ } else {
+ atomic_inc(&ref->usage);
+ ref->tree = tree;
+ ref->in_tree = 1;
+ list_add_tail(&ref->list, &tree->list);
+ }
+ spin_unlock(&tree->lock);
+ return ret;
+}
+
+/*
+ * remove a single leaf ref from the tree. This drops the ref held by the tree
+ * only
+ */
+int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref)
+{
+ struct btrfs_leaf_ref_tree *tree;
+
+ if (!xchg(&ref->in_tree, 0))
+ return 0;
+
+ tree = ref->tree;
+ spin_lock(&tree->lock);
+
+ rb_erase(&ref->rb_node, &tree->root);
+ list_del_init(&ref->list);
+
+ spin_unlock(&tree->lock);
+
+ btrfs_free_leaf_ref(root, ref);
+ return 0;
+}
diff --git a/fs/btrfs/ref-cache.h b/fs/btrfs/ref-cache.h
new file mode 100644
index 0000000..16f3183
--- /dev/null
+++ b/fs/btrfs/ref-cache.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#ifndef __REFCACHE__
+#define __REFCACHE__
+
+struct btrfs_extent_info {
+ /* bytenr and num_bytes find the extent in the extent allocation tree */
+ u64 bytenr;
+ u64 num_bytes;
+
+ /* objectid and offset find the back reference for the file */
+ u64 objectid;
+ u64 offset;
+};
+
+struct btrfs_leaf_ref {
+ struct rb_node rb_node;
+ struct btrfs_leaf_ref_tree *tree;
+ int in_tree;
+ atomic_t usage;
+
+ u64 root_gen;
+ u64 bytenr;
+ u64 owner;
+ u64 generation;
+ int nritems;
+
+ struct list_head list;
+ struct btrfs_extent_info extents[];
+};
+
+static inline size_t btrfs_leaf_ref_size(int nr_extents)
+{
+ return sizeof(struct btrfs_leaf_ref) +
+ sizeof(struct btrfs_extent_info) * nr_extents;
+}
+
+static inline void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree)
+{
+ tree->root.rb_node = NULL;
+ INIT_LIST_HEAD(&tree->list);
+ spin_lock_init(&tree->lock);
+}
+
+static inline int btrfs_leaf_ref_tree_empty(struct btrfs_leaf_ref_tree *tree)
+{
+ return RB_EMPTY_ROOT(&tree->root);
+}
+
+void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree);
+struct btrfs_leaf_ref *btrfs_alloc_leaf_ref(struct btrfs_root *root,
+ int nr_extents);
+void btrfs_free_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
+struct btrfs_leaf_ref *btrfs_lookup_leaf_ref(struct btrfs_root *root,
+ u64 bytenr);
+int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref,
+ int shared);
+int btrfs_remove_leaf_refs(struct btrfs_root *root, u64 max_root_gen,
+ int shared);
+int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
+
+#endif
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
new file mode 100644
index 0000000..dbe20d4
--- /dev/null
+++ b/fs/btrfs/root-tree.c
@@ -0,0 +1,367 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "print-tree.h"
+
+/*
+ * search forward for a root, starting with objectid 'search_start'
+ * if a root key is found, the objectid we find is filled into 'found_objectid'
+ * and 0 is returned. < 0 is returned on error, 1 if there is nothing
+ * left in the tree.
+ */
+int btrfs_search_root(struct btrfs_root *root, u64 search_start,
+ u64 *found_objectid)
+{
+ struct btrfs_path *path;
+ struct btrfs_key search_key;
+ int ret;
+
+ root = root->fs_info->tree_root;
+ search_key.objectid = search_start;
+ search_key.type = (u8)-1;
+ search_key.offset = (u64)-1;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+again:
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret == 0) {
+ ret = 1;
+ goto out;
+ }
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ goto out;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]);
+ if (search_key.type != BTRFS_ROOT_ITEM_KEY) {
+ search_key.offset++;
+ btrfs_release_path(root, path);
+ goto again;
+ }
+ ret = 0;
+ *found_objectid = search_key.objectid;
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * lookup the root with the highest offset for a given objectid. The key we do
+ * find is copied into 'key'. If we find something return 0, otherwise 1, < 0
+ * on error.
+ */
+int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
+ struct btrfs_root_item *item, struct btrfs_key *key)
+{
+ struct btrfs_path *path;
+ struct btrfs_key search_key;
+ struct btrfs_key found_key;
+ struct extent_buffer *l;
+ int ret;
+ int slot;
+
+ search_key.objectid = objectid;
+ search_key.type = BTRFS_ROOT_ITEM_KEY;
+ search_key.offset = (u64)-1;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ BUG_ON(ret == 0);
+ l = path->nodes[0];
+ BUG_ON(path->slots[0] == 0);
+ slot = path->slots[0] - 1;
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+ if (found_key.objectid != objectid) {
+ ret = 1;
+ goto out;
+ }
+ read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
+ sizeof(*item));
+ memcpy(key, &found_key, sizeof(found_key));
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * copy the data in 'item' into the btree
+ */
+int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *key, struct btrfs_root_item
+ *item)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *l;
+ int ret;
+ int slot;
+ unsigned long ptr;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_search_slot(trans, root, key, path, 0, 1);
+ if (ret < 0)
+ goto out;
+
+ if (ret != 0) {
+ btrfs_print_leaf(root, path->nodes[0]);
+ printk("unable to update root key %Lu %u %Lu\n",
+ key->objectid, key->type, key->offset);
+ BUG_ON(1);
+ }
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+ ptr = btrfs_item_ptr_offset(l, slot);
+ write_extent_buffer(l, item, ptr, sizeof(*item));
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_key *key, struct btrfs_root_item
+ *item)
+{
+ int ret;
+ ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
+ return ret;
+}
+
+/*
+ * at mount time we want to find all the old transaction snapshots that were in
+ * the process of being deleted if we crashed. This is any root item with an offset
+ * lower than the latest root. They need to be queued for deletion to finish
+ * what was happening when we crashed.
+ */
+int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
+ struct btrfs_root *latest)
+{
+ struct btrfs_root *dead_root;
+ struct btrfs_item *item;
+ struct btrfs_root_item *ri;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+ int ret;
+ u32 nritems;
+ struct extent_buffer *leaf;
+ int slot;
+
+ key.objectid = objectid;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ key.offset = 0;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+again:
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+ while(1) {
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+ if (slot >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ break;
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+ }
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
+ goto next;
+
+ if (key.objectid < objectid)
+ goto next;
+
+ if (key.objectid > objectid)
+ break;
+
+ ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
+ if (btrfs_disk_root_refs(leaf, ri) != 0)
+ goto next;
+
+ memcpy(&found_key, &key, sizeof(key));
+ key.offset++;
+ btrfs_release_path(root, path);
+ dead_root =
+ btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
+ &found_key);
+ if (IS_ERR(dead_root)) {
+ ret = PTR_ERR(dead_root);
+ goto err;
+ }
+
+ if (objectid == BTRFS_TREE_RELOC_OBJECTID)
+ ret = btrfs_add_dead_reloc_root(dead_root);
+ else
+ ret = btrfs_add_dead_root(dead_root, latest);
+ if (ret)
+ goto err;
+ goto again;
+next:
+ slot++;
+ path->slots[0]++;
+ }
+ ret = 0;
+err:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/* drop the root item for 'key' from 'root' */
+int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_key *key)
+{
+ struct btrfs_path *path;
+ int ret;
+ u32 refs;
+ struct btrfs_root_item *ri;
+ struct extent_buffer *leaf;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_search_slot(trans, root, key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+ if (ret) {
+btrfs_print_leaf(root, path->nodes[0]);
+printk("failed to del %Lu %u %Lu\n", key->objectid, key->type, key->offset);
+
+ }
+ BUG_ON(ret != 0);
+ leaf = path->nodes[0];
+ ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
+
+ refs = btrfs_disk_root_refs(leaf, ri);
+ BUG_ON(refs != 0);
+ ret = btrfs_del_item(trans, root, path);
+out:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *tree_root,
+ u64 root_id, u8 type, u64 ref_id)
+{
+ struct btrfs_key key;
+ int ret;
+ struct btrfs_path *path;
+
+ path = btrfs_alloc_path();
+
+ key.objectid = root_id;
+ key.type = type;
+ key.offset = ref_id;
+
+ ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
+ BUG_ON(ret);
+
+ ret = btrfs_del_item(trans, tree_root, path);
+ BUG_ON(ret);
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_find_root_ref(struct btrfs_root *tree_root,
+ struct btrfs_path *path,
+ u64 root_id, u64 ref_id)
+{
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = root_id;
+ key.type = BTRFS_ROOT_REF_KEY;
+ key.offset = ref_id;
+
+ ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
+ return ret;
+}
+
+
+/*
+ * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
+ * or BTRFS_ROOT_BACKREF_KEY.
+ *
+ * The dirid, sequence, name and name_len refer to the directory entry
+ * that is referencing the root.
+ *
+ * For a forward ref, the root_id is the id of the tree referencing
+ * the root and ref_id is the id of the subvol or snapshot.
+ *
+ * For a back ref the root_id is the id of the subvol or snapshot and
+ * ref_id is the id of the tree referencing it.
+ */
+int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *tree_root,
+ u64 root_id, u8 type, u64 ref_id,
+ u64 dirid, u64 sequence,
+ const char *name, int name_len)
+{
+ struct btrfs_key key;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_root_ref *ref;
+ struct extent_buffer *leaf;
+ unsigned long ptr;
+
+
+ path = btrfs_alloc_path();
+
+ key.objectid = root_id;
+ key.type = type;
+ key.offset = ref_id;
+
+ ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
+ sizeof(*ref) + name_len);
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
+ btrfs_set_root_ref_dirid(leaf, ref, dirid);
+ btrfs_set_root_ref_sequence(leaf, ref, sequence);
+ btrfs_set_root_ref_name_len(leaf, ref, name_len);
+ ptr = (unsigned long)(ref + 1);
+ write_extent_buffer(leaf, name, ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+
+ btrfs_free_path(path);
+ return ret;
+}
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
new file mode 100644
index 0000000..cdedbe1
--- /dev/null
+++ b/fs/btrfs/struct-funcs.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/highmem.h>
+
+/* this is some deeply nasty code. ctree.h has a different
+ * definition for this BTRFS_SETGET_FUNCS macro, behind a #ifndef
+ *
+ * The end result is that anyone who #includes ctree.h gets a
+ * declaration for the btrfs_set_foo functions and btrfs_foo functions
+ *
+ * This file declares the macros and then #includes ctree.h, which results
+ * in cpp creating the function here based on the template below.
+ *
+ * These setget functions do all the extent_buffer related mapping
+ * required to efficiently read and write specific fields in the extent
+ * buffers. Every pointer to metadata items in btrfs is really just
+ * an unsigned long offset into the extent buffer which has been
+ * cast to a specific type. This gives us all the gcc type checking.
+ *
+ * The extent buffer api is used to do all the kmapping and page
+ * spanning work required to get extent buffers in highmem and have
+ * a metadata blocksize different from the page size.
+ */
+
+#define BTRFS_SETGET_FUNCS(name, type, member, bits) \
+u##bits btrfs_##name(struct extent_buffer *eb, \
+ type *s) \
+{ \
+ unsigned long part_offset = (unsigned long)s; \
+ unsigned long offset = part_offset + offsetof(type, member); \
+ type *p; \
+ /* ugly, but we want the fast path here */ \
+ if (eb->map_token && offset >= eb->map_start && \
+ offset + sizeof(((type *)0)->member) <= eb->map_start + \
+ eb->map_len) { \
+ p = (type *)(eb->kaddr + part_offset - eb->map_start); \
+ return le##bits##_to_cpu(p->member); \
+ } \
+ { \
+ int err; \
+ char *map_token; \
+ char *kaddr; \
+ int unmap_on_exit = (eb->map_token == NULL); \
+ unsigned long map_start; \
+ unsigned long map_len; \
+ __le##bits res; \
+ err = map_extent_buffer(eb, offset, \
+ sizeof(((type *)0)->member), \
+ &map_token, &kaddr, \
+ &map_start, &map_len, KM_USER1); \
+ if (err) { \
+ read_eb_member(eb, s, type, member, &res); \
+ return le##bits##_to_cpu(res); \
+ } \
+ p = (type *)(kaddr + part_offset - map_start); \
+ res = le##bits##_to_cpu(p->member); \
+ if (unmap_on_exit) \
+ unmap_extent_buffer(eb, map_token, KM_USER1); \
+ return res; \
+ } \
+} \
+void btrfs_set_##name(struct extent_buffer *eb, \
+ type *s, u##bits val) \
+{ \
+ unsigned long part_offset = (unsigned long)s; \
+ unsigned long offset = part_offset + offsetof(type, member); \
+ type *p; \
+ /* ugly, but we want the fast path here */ \
+ if (eb->map_token && offset >= eb->map_start && \
+ offset + sizeof(((type *)0)->member) <= eb->map_start + \
+ eb->map_len) { \
+ p = (type *)(eb->kaddr + part_offset - eb->map_start); \
+ p->member = cpu_to_le##bits(val); \
+ return; \
+ } \
+ { \
+ int err; \
+ char *map_token; \
+ char *kaddr; \
+ int unmap_on_exit = (eb->map_token == NULL); \
+ unsigned long map_start; \
+ unsigned long map_len; \
+ err = map_extent_buffer(eb, offset, \
+ sizeof(((type *)0)->member), \
+ &map_token, &kaddr, \
+ &map_start, &map_len, KM_USER1); \
+ if (err) { \
+ val = cpu_to_le##bits(val); \
+ write_eb_member(eb, s, type, member, &val); \
+ return; \
+ } \
+ p = (type *)(kaddr + part_offset - map_start); \
+ p->member = cpu_to_le##bits(val); \
+ if (unmap_on_exit) \
+ unmap_extent_buffer(eb, map_token, KM_USER1); \
+ } \
+}
+
+#include "ctree.h"
+
+void btrfs_node_key(struct extent_buffer *eb,
+ struct btrfs_disk_key *disk_key, int nr)
+{
+ unsigned long ptr = btrfs_node_key_ptr_offset(nr);
+ if (eb->map_token && ptr >= eb->map_start &&
+ ptr + sizeof(*disk_key) <= eb->map_start + eb->map_len) {
+ memcpy(disk_key, eb->kaddr + ptr - eb->map_start,
+ sizeof(*disk_key));
+ return;
+ } else if (eb->map_token) {
+ unmap_extent_buffer(eb, eb->map_token, KM_USER1);
+ eb->map_token = NULL;
+ }
+ read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
+ struct btrfs_key_ptr, key, disk_key);
+}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
new file mode 100644
index 0000000..77c5eff
--- /dev/null
+++ b/fs/btrfs/super.c
@@ -0,0 +1,713 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mount.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/parser.h>
+#include <linux/ctype.h>
+#include <linux/namei.h>
+#include <linux/miscdevice.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+#include "xattr.h"
+#include "volumes.h"
+#include "version.h"
+#include "export.h"
+#include "compression.h"
+
+#define BTRFS_SUPER_MAGIC 0x9123683E
+
+static struct super_operations btrfs_super_ops;
+
+static void btrfs_put_super (struct super_block * sb)
+{
+ struct btrfs_root *root = btrfs_sb(sb);
+ struct btrfs_fs_info *fs = root->fs_info;
+ int ret;
+
+ ret = close_ctree(root);
+ if (ret) {
+ printk("close ctree returns %d\n", ret);
+ }
+ btrfs_sysfs_del_super(fs);
+ sb->s_fs_info = NULL;
+}
+
+enum {
+ Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
+ Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
+ Opt_ssd, Opt_thread_pool, Opt_noacl, Opt_compress, Opt_err,
+};
+
+static match_table_t tokens = {
+ {Opt_degraded, "degraded"},
+ {Opt_subvol, "subvol=%s"},
+ {Opt_device, "device=%s"},
+ {Opt_nodatasum, "nodatasum"},
+ {Opt_nodatacow, "nodatacow"},
+ {Opt_nobarrier, "nobarrier"},
+ {Opt_max_extent, "max_extent=%s"},
+ {Opt_max_inline, "max_inline=%s"},
+ {Opt_alloc_start, "alloc_start=%s"},
+ {Opt_thread_pool, "thread_pool=%d"},
+ {Opt_compress, "compress"},
+ {Opt_ssd, "ssd"},
+ {Opt_noacl, "noacl"},
+ {Opt_err, NULL},
+};
+
+u64 btrfs_parse_size(char *str)
+{
+ u64 res;
+ int mult = 1;
+ char *end;
+ char last;
+
+ res = simple_strtoul(str, &end, 10);
+
+ last = end[0];
+ if (isalpha(last)) {
+ last = tolower(last);
+ switch (last) {
+ case 'g':
+ mult *= 1024;
+ case 'm':
+ mult *= 1024;
+ case 'k':
+ mult *= 1024;
+ }
+ res = res * mult;
+ }
+ return res;
+}
+
+/*
+ * Regular mount options parser. Everything that is needed only when
+ * reading in a new superblock is parsed here.
+ */
+int btrfs_parse_options(struct btrfs_root *root, char *options)
+{
+ struct btrfs_fs_info *info = root->fs_info;
+ substring_t args[MAX_OPT_ARGS];
+ char *p, *num;
+ int intarg;
+
+ if (!options)
+ return 0;
+
+ /*
+ * strsep changes the string, duplicate it because parse_options
+ * gets called twice
+ */
+ options = kstrdup(options, GFP_NOFS);
+ if (!options)
+ return -ENOMEM;
+
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_degraded:
+ printk(KERN_INFO "btrfs: allowing degraded mounts\n");
+ btrfs_set_opt(info->mount_opt, DEGRADED);
+ break;
+ case Opt_subvol:
+ case Opt_device:
+ /*
+ * These are parsed by btrfs_parse_early_options
+ * and can be happily ignored here.
+ */
+ break;
+ case Opt_nodatasum:
+ printk(KERN_INFO "btrfs: setting nodatacsum\n");
+ btrfs_set_opt(info->mount_opt, NODATASUM);
+ break;
+ case Opt_nodatacow:
+ printk(KERN_INFO "btrfs: setting nodatacow\n");
+ btrfs_set_opt(info->mount_opt, NODATACOW);
+ btrfs_set_opt(info->mount_opt, NODATASUM);
+ break;
+ case Opt_compress:
+ printk(KERN_INFO "btrfs: use compression\n");
+ btrfs_set_opt(info->mount_opt, COMPRESS);
+ break;
+ case Opt_ssd:
+ printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
+ btrfs_set_opt(info->mount_opt, SSD);
+ break;
+ case Opt_nobarrier:
+ printk(KERN_INFO "btrfs: turning off barriers\n");
+ btrfs_set_opt(info->mount_opt, NOBARRIER);
+ break;
+ case Opt_thread_pool:
+ intarg = 0;
+ match_int(&args[0], &intarg);
+ if (intarg) {
+ info->thread_pool_size = intarg;
+ printk(KERN_INFO "btrfs: thread pool %d\n",
+ info->thread_pool_size);
+ }
+ break;
+ case Opt_max_extent:
+ num = match_strdup(&args[0]);
+ if (num) {
+ info->max_extent = btrfs_parse_size(num);
+ kfree(num);
+
+ info->max_extent = max_t(u64,
+ info->max_extent, root->sectorsize);
+ printk(KERN_INFO "btrfs: max_extent at %llu\n",
+ info->max_extent);
+ }
+ break;
+ case Opt_max_inline:
+ num = match_strdup(&args[0]);
+ if (num) {
+ info->max_inline = btrfs_parse_size(num);
+ kfree(num);
+
+ if (info->max_inline) {
+ info->max_inline = max_t(u64,
+ info->max_inline,
+ root->sectorsize);
+ }
+ printk(KERN_INFO "btrfs: max_inline at %llu\n",
+ info->max_inline);
+ }
+ break;
+ case Opt_alloc_start:
+ num = match_strdup(&args[0]);
+ if (num) {
+ info->alloc_start = btrfs_parse_size(num);
+ kfree(num);
+ printk(KERN_INFO
+ "btrfs: allocations start at %llu\n",
+ info->alloc_start);
+ }
+ break;
+ case Opt_noacl:
+ root->fs_info->sb->s_flags &= ~MS_POSIXACL;
+ break;
+ default:
+ break;
+ }
+ }
+ kfree(options);
+ return 0;
+}
+
+/*
+ * Parse mount options that are required early in the mount process.
+ *
+ * All other options will be parsed on much later in the mount process and
+ * only when we need to allocate a new super block.
+ */
+static int btrfs_parse_early_options(const char *options, int flags,
+ void *holder, char **subvol_name,
+ struct btrfs_fs_devices **fs_devices)
+{
+ substring_t args[MAX_OPT_ARGS];
+ char *opts, *p;
+ int error = 0;
+
+ if (!options)
+ goto out;
+
+ /*
+ * strsep changes the string, duplicate it because parse_options
+ * gets called twice
+ */
+ opts = kstrdup(options, GFP_KERNEL);
+ if (!opts)
+ return -ENOMEM;
+
+ while ((p = strsep(&opts, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_subvol:
+ *subvol_name = match_strdup(&args[0]);
+ break;
+ case Opt_device:
+ error = btrfs_scan_one_device(match_strdup(&args[0]),
+ flags, holder, fs_devices);
+ if (error)
+ goto out_free_opts;
+ break;
+ default:
+ break;
+ }
+ }
+
+ out_free_opts:
+ kfree(opts);
+ out:
+ /*
+ * If no subvolume name is specified we use the default one. Allocate
+ * a copy of the string "." here so that code later in the
+ * mount path doesn't care if it's the default volume or another one.
+ */
+ if (!*subvol_name) {
+ *subvol_name = kstrdup(".", GFP_KERNEL);
+ if (!*subvol_name)
+ return -ENOMEM;
+ }
+ return error;
+}
+
+static int btrfs_fill_super(struct super_block * sb,
+ struct btrfs_fs_devices *fs_devices,
+ void * data, int silent)
+{
+ struct inode * inode;
+ struct dentry * root_dentry;
+ struct btrfs_super_block *disk_super;
+ struct btrfs_root *tree_root;
+ struct btrfs_inode *bi;
+ int err;
+
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_magic = BTRFS_SUPER_MAGIC;
+ sb->s_op = &btrfs_super_ops;
+ sb->s_export_op = &btrfs_export_ops;
+ sb->s_xattr = btrfs_xattr_handlers;
+ sb->s_time_gran = 1;
+ sb->s_flags |= MS_POSIXACL;
+
+ tree_root = open_ctree(sb, fs_devices, (char *)data);
+
+ if (IS_ERR(tree_root)) {
+ printk("btrfs: open_ctree failed\n");
+ return PTR_ERR(tree_root);
+ }
+ sb->s_fs_info = tree_root;
+ disk_super = &tree_root->fs_info->super_copy;
+ inode = btrfs_iget_locked(sb, BTRFS_FIRST_FREE_OBJECTID,
+ tree_root->fs_info->fs_root);
+ bi = BTRFS_I(inode);
+ bi->location.objectid = inode->i_ino;
+ bi->location.offset = 0;
+ bi->root = tree_root->fs_info->fs_root;
+
+ btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
+
+ if (!inode) {
+ err = -ENOMEM;
+ goto fail_close;
+ }
+ if (inode->i_state & I_NEW) {
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ }
+
+ root_dentry = d_alloc_root(inode);
+ if (!root_dentry) {
+ iput(inode);
+ err = -ENOMEM;
+ goto fail_close;
+ }
+
+ /* this does the super kobj at the same time */
+ err = btrfs_sysfs_add_super(tree_root->fs_info);
+ if (err)
+ goto fail_close;
+
+ sb->s_root = root_dentry;
+
+ save_mount_options(sb, data);
+ return 0;
+
+fail_close:
+ close_ctree(tree_root);
+ return err;
+}
+
+int btrfs_sync_fs(struct super_block *sb, int wait)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root;
+ int ret;
+ root = btrfs_sb(sb);
+
+ if (sb->s_flags & MS_RDONLY)
+ return 0;
+
+ sb->s_dirt = 0;
+ if (!wait) {
+ filemap_flush(root->fs_info->btree_inode->i_mapping);
+ return 0;
+ }
+
+ btrfs_start_delalloc_inodes(root);
+ btrfs_wait_ordered_extents(root, 0);
+
+ btrfs_clean_old_snapshots(root);
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_commit_transaction(trans, root);
+ sb->s_dirt = 0;
+ return ret;
+}
+
+static void btrfs_write_super(struct super_block *sb)
+{
+ sb->s_dirt = 0;
+}
+
+static int btrfs_test_super(struct super_block *s, void *data)
+{
+ struct btrfs_fs_devices *test_fs_devices = data;
+ struct btrfs_root *root = btrfs_sb(s);
+
+ return root->fs_info->fs_devices == test_fs_devices;
+}
+
+/*
+ * Find a superblock for the given device / mount point.
+ *
+ * Note: This is based on get_sb_bdev from fs/super.c with a few additions
+ * for multiple device setup. Make sure to keep it in sync.
+ */
+static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
+ const char *dev_name, void *data, struct vfsmount *mnt)
+{
+ char *subvol_name = NULL;
+ struct block_device *bdev = NULL;
+ struct super_block *s;
+ struct dentry *root;
+ struct btrfs_fs_devices *fs_devices = NULL;
+ int error = 0;
+
+ error = btrfs_parse_early_options(data, flags, fs_type,
+ &subvol_name, &fs_devices);
+ if (error)
+ goto error;
+
+ error = btrfs_scan_one_device(dev_name, flags, fs_type, &fs_devices);
+ if (error)
+ goto error_free_subvol_name;
+
+ error = btrfs_open_devices(fs_devices, flags, fs_type);
+ if (error)
+ goto error_free_subvol_name;
+
+ if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
+ error = -EACCES;
+ goto error_close_devices;
+ }
+
+ bdev = fs_devices->latest_bdev;
+ s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
+ if (IS_ERR(s))
+ goto error_s;
+
+ if (s->s_root) {
+ if ((flags ^ s->s_flags) & MS_RDONLY) {
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ error = -EBUSY;
+ goto error_close_devices;
+ }
+
+ btrfs_close_devices(fs_devices);
+ } else {
+ char b[BDEVNAME_SIZE];
+
+ s->s_flags = flags;
+ strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
+ error = btrfs_fill_super(s, fs_devices, data,
+ flags & MS_SILENT ? 1 : 0);
+ if (error) {
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ goto error;
+ }
+
+ btrfs_sb(s)->fs_info->bdev_holder = fs_type;
+ s->s_flags |= MS_ACTIVE;
+ }
+
+ if (!strcmp(subvol_name, "."))
+ root = dget(s->s_root);
+ else {
+ mutex_lock(&s->s_root->d_inode->i_mutex);
+ root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name));
+ mutex_unlock(&s->s_root->d_inode->i_mutex);
+ if (IS_ERR(root)) {
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ error = PTR_ERR(root);
+ goto error;
+ }
+ if (!root->d_inode) {
+ dput(root);
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ error = -ENXIO;
+ goto error;
+ }
+ }
+
+ mnt->mnt_sb = s;
+ mnt->mnt_root = root;
+
+ kfree(subvol_name);
+ return 0;
+
+error_s:
+ error = PTR_ERR(s);
+error_close_devices:
+ btrfs_close_devices(fs_devices);
+error_free_subvol_name:
+ kfree(subvol_name);
+error:
+ return error;
+}
+
+static int btrfs_remount(struct super_block *sb, int *flags, char *data)
+{
+ struct btrfs_root *root = btrfs_sb(sb);
+ int ret;
+
+ if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
+ return 0;
+
+ if (*flags & MS_RDONLY) {
+ sb->s_flags |= MS_RDONLY;
+
+ ret = btrfs_commit_super(root);
+ WARN_ON(ret);
+ } else {
+ if (root->fs_info->fs_devices->rw_devices == 0)
+ return -EACCES;
+
+ if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
+ return -EINVAL;
+
+ ret = btrfs_cleanup_reloc_trees(root);
+ WARN_ON(ret);
+
+ ret = btrfs_cleanup_fs_roots(root->fs_info);
+ WARN_ON(ret);
+
+ sb->s_flags &= ~MS_RDONLY;
+ }
+
+ return 0;
+}
+
+static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct btrfs_root *root = btrfs_sb(dentry->d_sb);
+ struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
+ int bits = dentry->d_sb->s_blocksize_bits;
+ __be32 *fsid = (__be32 *)root->fs_info->fsid;
+
+ buf->f_namelen = BTRFS_NAME_LEN;
+ buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
+ buf->f_bfree = buf->f_blocks -
+ (btrfs_super_bytes_used(disk_super) >> bits);
+ buf->f_bavail = buf->f_bfree;
+ buf->f_bsize = dentry->d_sb->s_blocksize;
+ buf->f_type = BTRFS_SUPER_MAGIC;
+ /* We treat it as constant endianness (it doesn't matter _which_)
+ because we want the fsid to come out the same whether mounted
+ on a big-endian or little-endian host */
+ buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
+ buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
+ /* Mask in the root object ID too, to disambiguate subvols */
+ buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
+ buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
+
+ return 0;
+}
+
+static struct file_system_type btrfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "btrfs",
+ .get_sb = btrfs_get_sb,
+ .kill_sb = kill_anon_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+
+/*
+ * used by btrfsctl to scan devices when no FS is mounted
+ */
+static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct btrfs_ioctl_vol_args *vol;
+ struct btrfs_fs_devices *fs_devices;
+ int ret = 0;
+ int len;
+
+ vol = kmalloc(sizeof(*vol), GFP_KERNEL);
+ if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
+ ret = -EFAULT;
+ goto out;
+ }
+ len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
+ switch (cmd) {
+ case BTRFS_IOC_SCAN_DEV:
+ ret = btrfs_scan_one_device(vol->name, MS_RDONLY,
+ &btrfs_fs_type, &fs_devices);
+ break;
+ }
+out:
+ kfree(vol);
+ return ret;
+}
+
+static void btrfs_write_super_lockfs(struct super_block *sb)
+{
+ struct btrfs_root *root = btrfs_sb(sb);
+ mutex_lock(&root->fs_info->transaction_kthread_mutex);
+ mutex_lock(&root->fs_info->cleaner_mutex);
+}
+
+static void btrfs_unlockfs(struct super_block *sb)
+{
+ struct btrfs_root *root = btrfs_sb(sb);
+ mutex_unlock(&root->fs_info->cleaner_mutex);
+ mutex_unlock(&root->fs_info->transaction_kthread_mutex);
+}
+
+static struct super_operations btrfs_super_ops = {
+ .delete_inode = btrfs_delete_inode,
+ .put_super = btrfs_put_super,
+ .write_super = btrfs_write_super,
+ .sync_fs = btrfs_sync_fs,
+ .show_options = generic_show_options,
+ .write_inode = btrfs_write_inode,
+ .dirty_inode = btrfs_dirty_inode,
+ .alloc_inode = btrfs_alloc_inode,
+ .destroy_inode = btrfs_destroy_inode,
+ .statfs = btrfs_statfs,
+ .remount_fs = btrfs_remount,
+ .write_super_lockfs = btrfs_write_super_lockfs,
+ .unlockfs = btrfs_unlockfs,
+};
+
+static const struct file_operations btrfs_ctl_fops = {
+ .unlocked_ioctl = btrfs_control_ioctl,
+ .compat_ioctl = btrfs_control_ioctl,
+ .owner = THIS_MODULE,
+};
+
+static struct miscdevice btrfs_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "btrfs-control",
+ .fops = &btrfs_ctl_fops
+};
+
+static int btrfs_interface_init(void)
+{
+ return misc_register(&btrfs_misc);
+}
+
+void btrfs_interface_exit(void)
+{
+ if (misc_deregister(&btrfs_misc) < 0)
+ printk("misc_deregister failed for control device");
+}
+
+static int __init init_btrfs_fs(void)
+{
+ int err;
+
+ err = btrfs_init_sysfs();
+ if (err)
+ return err;
+
+ err = btrfs_init_cachep();
+ if (err)
+ goto free_sysfs;
+
+ err = extent_io_init();
+ if (err)
+ goto free_cachep;
+
+ err = extent_map_init();
+ if (err)
+ goto free_extent_io;
+
+ err = btrfs_interface_init();
+ if (err)
+ goto free_extent_map;
+
+ err = register_filesystem(&btrfs_fs_type);
+ if (err)
+ goto unregister_ioctl;
+
+ printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
+ return 0;
+
+unregister_ioctl:
+ btrfs_interface_exit();
+free_extent_map:
+ extent_map_exit();
+free_extent_io:
+ extent_io_exit();
+free_cachep:
+ btrfs_destroy_cachep();
+free_sysfs:
+ btrfs_exit_sysfs();
+ return err;
+}
+
+static void __exit exit_btrfs_fs(void)
+{
+ btrfs_destroy_cachep();
+ extent_map_exit();
+ extent_io_exit();
+ btrfs_interface_exit();
+ unregister_filesystem(&btrfs_fs_type);
+ btrfs_exit_sysfs();
+ btrfs_cleanup_fs_uuids();
+ btrfs_zlib_exit();
+}
+
+module_init(init_btrfs_fs)
+module_exit(exit_btrfs_fs)
+
+MODULE_LICENSE("GPL");
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
new file mode 100644
index 0000000..300076e
--- /dev/null
+++ b/fs/btrfs/sysfs.c
@@ -0,0 +1,268 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+static ssize_t root_blocks_used_show(struct btrfs_root *root, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_root_used(&root->root_item));
+}
+
+static ssize_t root_block_limit_show(struct btrfs_root *root, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_root_limit(&root->root_item));
+}
+
+static ssize_t super_blocks_used_show(struct btrfs_fs_info *fs, char *buf)
+{
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_super_bytes_used(&fs->super_copy));
+}
+
+static ssize_t super_total_blocks_show(struct btrfs_fs_info *fs, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_super_total_bytes(&fs->super_copy));
+}
+
+static ssize_t super_blocksize_show(struct btrfs_fs_info *fs, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_super_sectorsize(&fs->super_copy));
+}
+
+/* this is for root attrs (subvols/snapshots) */
+struct btrfs_root_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct btrfs_root *, char *);
+ ssize_t (*store)(struct btrfs_root *, const char *, size_t);
+};
+
+#define ROOT_ATTR(name, mode, show, store) \
+static struct btrfs_root_attr btrfs_root_attr_##name = __ATTR(name, mode, show, store)
+
+ROOT_ATTR(blocks_used, 0444, root_blocks_used_show, NULL);
+ROOT_ATTR(block_limit, 0644, root_block_limit_show, NULL);
+
+static struct attribute *btrfs_root_attrs[] = {
+ &btrfs_root_attr_blocks_used.attr,
+ &btrfs_root_attr_block_limit.attr,
+ NULL,
+};
+
+/* this is for super attrs (actual full fs) */
+struct btrfs_super_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct btrfs_fs_info *, char *);
+ ssize_t (*store)(struct btrfs_fs_info *, const char *, size_t);
+};
+
+#define SUPER_ATTR(name, mode, show, store) \
+static struct btrfs_super_attr btrfs_super_attr_##name = __ATTR(name, mode, show, store)
+
+SUPER_ATTR(blocks_used, 0444, super_blocks_used_show, NULL);
+SUPER_ATTR(total_blocks, 0444, super_total_blocks_show, NULL);
+SUPER_ATTR(blocksize, 0444, super_blocksize_show, NULL);
+
+static struct attribute *btrfs_super_attrs[] = {
+ &btrfs_super_attr_blocks_used.attr,
+ &btrfs_super_attr_total_blocks.attr,
+ &btrfs_super_attr_blocksize.attr,
+ NULL,
+};
+
+static ssize_t btrfs_super_attr_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
+ super_kobj);
+ struct btrfs_super_attr *a = container_of(attr,
+ struct btrfs_super_attr,
+ attr);
+
+ return a->show ? a->show(fs, buf) : 0;
+}
+
+static ssize_t btrfs_super_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
+ super_kobj);
+ struct btrfs_super_attr *a = container_of(attr,
+ struct btrfs_super_attr,
+ attr);
+
+ return a->store ? a->store(fs, buf, len) : 0;
+}
+
+static ssize_t btrfs_root_attr_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct btrfs_root *root = container_of(kobj, struct btrfs_root,
+ root_kobj);
+ struct btrfs_root_attr *a = container_of(attr,
+ struct btrfs_root_attr,
+ attr);
+
+ return a->show ? a->show(root, buf) : 0;
+}
+
+static ssize_t btrfs_root_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct btrfs_root *root = container_of(kobj, struct btrfs_root,
+ root_kobj);
+ struct btrfs_root_attr *a = container_of(attr,
+ struct btrfs_root_attr,
+ attr);
+ return a->store ? a->store(root, buf, len) : 0;
+}
+
+static void btrfs_super_release(struct kobject *kobj)
+{
+ struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
+ super_kobj);
+ complete(&fs->kobj_unregister);
+}
+
+static void btrfs_root_release(struct kobject *kobj)
+{
+ struct btrfs_root *root = container_of(kobj, struct btrfs_root,
+ root_kobj);
+ complete(&root->kobj_unregister);
+}
+
+static struct sysfs_ops btrfs_super_attr_ops = {
+ .show = btrfs_super_attr_show,
+ .store = btrfs_super_attr_store,
+};
+
+static struct sysfs_ops btrfs_root_attr_ops = {
+ .show = btrfs_root_attr_show,
+ .store = btrfs_root_attr_store,
+};
+
+static struct kobj_type btrfs_root_ktype = {
+ .default_attrs = btrfs_root_attrs,
+ .sysfs_ops = &btrfs_root_attr_ops,
+ .release = btrfs_root_release,
+};
+
+static struct kobj_type btrfs_super_ktype = {
+ .default_attrs = btrfs_super_attrs,
+ .sysfs_ops = &btrfs_super_attr_ops,
+ .release = btrfs_super_release,
+};
+
+/* /sys/fs/btrfs/ entry */
+static struct kset *btrfs_kset;
+
+int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
+{
+ int error;
+ char *name;
+ char c;
+ int len = strlen(fs->sb->s_id) + 1;
+ int i;
+
+ name = kmalloc(len, GFP_NOFS);
+ if (!name) {
+ error = -ENOMEM;
+ goto fail;
+ }
+
+ for (i = 0; i < len; i++) {
+ c = fs->sb->s_id[i];
+ if (c == '/' || c == '\\')
+ c = '!';
+ name[i] = c;
+ }
+ name[len] = '\0';
+
+ fs->super_kobj.kset = btrfs_kset;
+ error = kobject_init_and_add(&fs->super_kobj, &btrfs_super_ktype,
+ NULL, "%s", name);
+ if (error)
+ goto fail;
+
+ kfree(name);
+ return 0;
+
+fail:
+ kfree(name);
+ printk(KERN_ERR "btrfs: sysfs creation for super failed\n");
+ return error;
+}
+
+int btrfs_sysfs_add_root(struct btrfs_root *root)
+{
+ int error;
+
+ error = kobject_init_and_add(&root->root_kobj, &btrfs_root_ktype,
+ &root->fs_info->super_kobj,
+ "%s", root->name);
+ if (error)
+ goto fail;
+
+ return 0;
+
+fail:
+ printk(KERN_ERR "btrfs: sysfs creation for root failed\n");
+ return error;
+}
+
+void btrfs_sysfs_del_root(struct btrfs_root *root)
+{
+ kobject_put(&root->root_kobj);
+ wait_for_completion(&root->kobj_unregister);
+}
+
+void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
+{
+ kobject_put(&fs->super_kobj);
+ wait_for_completion(&fs->kobj_unregister);
+}
+
+int btrfs_init_sysfs(void)
+{
+ btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
+ if (!btrfs_kset)
+ return -ENOMEM;
+ return 0;
+}
+
+void btrfs_exit_sysfs(void)
+{
+ kset_unregister(btrfs_kset);
+}
+
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
new file mode 100644
index 0000000..c2c3b42
--- /dev/null
+++ b/fs/btrfs/transaction.c
@@ -0,0 +1,1102 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/writeback.h>
+#include <linux/pagemap.h>
+#include <linux/blkdev.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "locking.h"
+#include "ref-cache.h"
+#include "tree-log.h"
+
+static int total_trans = 0;
+extern struct kmem_cache *btrfs_trans_handle_cachep;
+extern struct kmem_cache *btrfs_transaction_cachep;
+
+#define BTRFS_ROOT_TRANS_TAG 0
+
+static noinline void put_transaction(struct btrfs_transaction *transaction)
+{
+ WARN_ON(transaction->use_count == 0);
+ transaction->use_count--;
+ if (transaction->use_count == 0) {
+ WARN_ON(total_trans == 0);
+ total_trans--;
+ list_del_init(&transaction->list);
+ memset(transaction, 0, sizeof(*transaction));
+ kmem_cache_free(btrfs_transaction_cachep, transaction);
+ }
+}
+
+/*
+ * either allocate a new transaction or hop into the existing one
+ */
+static noinline int join_transaction(struct btrfs_root *root)
+{
+ struct btrfs_transaction *cur_trans;
+ cur_trans = root->fs_info->running_transaction;
+ if (!cur_trans) {
+ cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
+ GFP_NOFS);
+ total_trans++;
+ BUG_ON(!cur_trans);
+ root->fs_info->generation++;
+ root->fs_info->last_alloc = 0;
+ root->fs_info->last_data_alloc = 0;
+ cur_trans->num_writers = 1;
+ cur_trans->num_joined = 0;
+ cur_trans->transid = root->fs_info->generation;
+ init_waitqueue_head(&cur_trans->writer_wait);
+ init_waitqueue_head(&cur_trans->commit_wait);
+ cur_trans->in_commit = 0;
+ cur_trans->blocked = 0;
+ cur_trans->use_count = 1;
+ cur_trans->commit_done = 0;
+ cur_trans->start_time = get_seconds();
+ INIT_LIST_HEAD(&cur_trans->pending_snapshots);
+ list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
+ extent_io_tree_init(&cur_trans->dirty_pages,
+ root->fs_info->btree_inode->i_mapping,
+ GFP_NOFS);
+ spin_lock(&root->fs_info->new_trans_lock);
+ root->fs_info->running_transaction = cur_trans;
+ spin_unlock(&root->fs_info->new_trans_lock);
+ } else {
+ cur_trans->num_writers++;
+ cur_trans->num_joined++;
+ }
+
+ return 0;
+}
+
+/*
+ * this does all the record keeping required to make sure that a
+ * reference counted root is properly recorded in a given transaction.
+ * This is required to make sure the old root from before we joined the transaction
+ * is deleted when the transaction commits
+ */
+noinline int btrfs_record_root_in_trans(struct btrfs_root *root)
+{
+ struct btrfs_dirty_root *dirty;
+ u64 running_trans_id = root->fs_info->running_transaction->transid;
+ if (root->ref_cows && root->last_trans < running_trans_id) {
+ WARN_ON(root == root->fs_info->extent_root);
+ if (root->root_item.refs != 0) {
+ radix_tree_tag_set(&root->fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid,
+ BTRFS_ROOT_TRANS_TAG);
+
+ dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
+ BUG_ON(!dirty);
+ dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
+ BUG_ON(!dirty->root);
+ dirty->latest_root = root;
+ INIT_LIST_HEAD(&dirty->list);
+
+ root->commit_root = btrfs_root_node(root);
+
+ memcpy(dirty->root, root, sizeof(*root));
+ spin_lock_init(&dirty->root->node_lock);
+ spin_lock_init(&dirty->root->list_lock);
+ mutex_init(&dirty->root->objectid_mutex);
+ mutex_init(&dirty->root->log_mutex);
+ INIT_LIST_HEAD(&dirty->root->dead_list);
+ dirty->root->node = root->commit_root;
+ dirty->root->commit_root = NULL;
+
+ spin_lock(&root->list_lock);
+ list_add(&dirty->root->dead_list, &root->dead_list);
+ spin_unlock(&root->list_lock);
+
+ root->dirty_root = dirty;
+ } else {
+ WARN_ON(1);
+ }
+ root->last_trans = running_trans_id;
+ }
+ return 0;
+}
+
+/* wait for commit against the current transaction to become unblocked
+ * when this is done, it is safe to start a new transaction, but the current
+ * transaction might not be fully on disk.
+ */
+static void wait_current_trans(struct btrfs_root *root)
+{
+ struct btrfs_transaction *cur_trans;
+
+ cur_trans = root->fs_info->running_transaction;
+ if (cur_trans && cur_trans->blocked) {
+ DEFINE_WAIT(wait);
+ cur_trans->use_count++;
+ while(1) {
+ prepare_to_wait(&root->fs_info->transaction_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (cur_trans->blocked) {
+ mutex_unlock(&root->fs_info->trans_mutex);
+ schedule();
+ mutex_lock(&root->fs_info->trans_mutex);
+ finish_wait(&root->fs_info->transaction_wait,
+ &wait);
+ } else {
+ finish_wait(&root->fs_info->transaction_wait,
+ &wait);
+ break;
+ }
+ }
+ put_transaction(cur_trans);
+ }
+}
+
+static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
+ int num_blocks, int wait)
+{
+ struct btrfs_trans_handle *h =
+ kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
+ int ret;
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (!root->fs_info->log_root_recovering &&
+ ((wait == 1 && !root->fs_info->open_ioctl_trans) || wait == 2))
+ wait_current_trans(root);
+ ret = join_transaction(root);
+ BUG_ON(ret);
+
+ btrfs_record_root_in_trans(root);
+ h->transid = root->fs_info->running_transaction->transid;
+ h->transaction = root->fs_info->running_transaction;
+ h->blocks_reserved = num_blocks;
+ h->blocks_used = 0;
+ h->block_group = NULL;
+ h->alloc_exclude_nr = 0;
+ h->alloc_exclude_start = 0;
+ root->fs_info->running_transaction->use_count++;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ return h;
+}
+
+struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
+ int num_blocks)
+{
+ return start_transaction(root, num_blocks, 1);
+}
+struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
+ int num_blocks)
+{
+ return start_transaction(root, num_blocks, 0);
+}
+
+struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
+ int num_blocks)
+{
+ return start_transaction(r, num_blocks, 2);
+}
+
+/* wait for a transaction commit to be fully complete */
+static noinline int wait_for_commit(struct btrfs_root *root,
+ struct btrfs_transaction *commit)
+{
+ DEFINE_WAIT(wait);
+ mutex_lock(&root->fs_info->trans_mutex);
+ while(!commit->commit_done) {
+ prepare_to_wait(&commit->commit_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (commit->commit_done)
+ break;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ schedule();
+ mutex_lock(&root->fs_info->trans_mutex);
+ }
+ mutex_unlock(&root->fs_info->trans_mutex);
+ finish_wait(&commit->commit_wait, &wait);
+ return 0;
+}
+
+/*
+ * rate limit against the drop_snapshot code. This helps to slow down new operations
+ * if the drop_snapshot code isn't able to keep up.
+ */
+static void throttle_on_drops(struct btrfs_root *root)
+{
+ struct btrfs_fs_info *info = root->fs_info;
+ int harder_count = 0;
+
+harder:
+ if (atomic_read(&info->throttles)) {
+ DEFINE_WAIT(wait);
+ int thr;
+ thr = atomic_read(&info->throttle_gen);
+
+ do {
+ prepare_to_wait(&info->transaction_throttle,
+ &wait, TASK_UNINTERRUPTIBLE);
+ if (!atomic_read(&info->throttles)) {
+ finish_wait(&info->transaction_throttle, &wait);
+ break;
+ }
+ schedule();
+ finish_wait(&info->transaction_throttle, &wait);
+ } while (thr == atomic_read(&info->throttle_gen));
+ harder_count++;
+
+ if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 &&
+ harder_count < 2)
+ goto harder;
+
+ if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 &&
+ harder_count < 10)
+ goto harder;
+
+ if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 &&
+ harder_count < 20)
+ goto harder;
+ }
+}
+
+void btrfs_throttle(struct btrfs_root *root)
+{
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (!root->fs_info->open_ioctl_trans)
+ wait_current_trans(root);
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ throttle_on_drops(root);
+}
+
+static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, int throttle)
+{
+ struct btrfs_transaction *cur_trans;
+ struct btrfs_fs_info *info = root->fs_info;
+
+ mutex_lock(&info->trans_mutex);
+ cur_trans = info->running_transaction;
+ WARN_ON(cur_trans != trans->transaction);
+ WARN_ON(cur_trans->num_writers < 1);
+ cur_trans->num_writers--;
+
+ if (waitqueue_active(&cur_trans->writer_wait))
+ wake_up(&cur_trans->writer_wait);
+ put_transaction(cur_trans);
+ mutex_unlock(&info->trans_mutex);
+ memset(trans, 0, sizeof(*trans));
+ kmem_cache_free(btrfs_trans_handle_cachep, trans);
+
+ if (throttle)
+ throttle_on_drops(root);
+
+ return 0;
+}
+
+int btrfs_end_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ return __btrfs_end_transaction(trans, root, 0);
+}
+
+int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ return __btrfs_end_transaction(trans, root, 1);
+}
+
+/*
+ * when btree blocks are allocated, they have some corresponding bits set for
+ * them in one of two extent_io trees. This is used to make sure all of
+ * those extents are on disk for transaction or log commit
+ */
+int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
+ struct extent_io_tree *dirty_pages)
+{
+ int ret;
+ int err = 0;
+ int werr = 0;
+ struct page *page;
+ struct inode *btree_inode = root->fs_info->btree_inode;
+ u64 start = 0;
+ u64 end;
+ unsigned long index;
+
+ while(1) {
+ ret = find_first_extent_bit(dirty_pages, start, &start, &end,
+ EXTENT_DIRTY);
+ if (ret)
+ break;
+ while(start <= end) {
+ cond_resched();
+
+ index = start >> PAGE_CACHE_SHIFT;
+ start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
+ page = find_get_page(btree_inode->i_mapping, index);
+ if (!page)
+ continue;
+
+ btree_lock_page_hook(page);
+ if (!page->mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ continue;
+ }
+
+ if (PageWriteback(page)) {
+ if (PageDirty(page))
+ wait_on_page_writeback(page);
+ else {
+ unlock_page(page);
+ page_cache_release(page);
+ continue;
+ }
+ }
+ err = write_one_page(page, 0);
+ if (err)
+ werr = err;
+ page_cache_release(page);
+ }
+ }
+ while(1) {
+ ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
+ EXTENT_DIRTY);
+ if (ret)
+ break;
+
+ clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
+ while(start <= end) {
+ index = start >> PAGE_CACHE_SHIFT;
+ start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
+ page = find_get_page(btree_inode->i_mapping, index);
+ if (!page)
+ continue;
+ if (PageDirty(page)) {
+ btree_lock_page_hook(page);
+ wait_on_page_writeback(page);
+ err = write_one_page(page, 0);
+ if (err)
+ werr = err;
+ }
+ wait_on_page_writeback(page);
+ page_cache_release(page);
+ cond_resched();
+ }
+ }
+ if (err)
+ werr = err;
+ return werr;
+}
+
+int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ if (!trans || !trans->transaction) {
+ struct inode *btree_inode;
+ btree_inode = root->fs_info->btree_inode;
+ return filemap_write_and_wait(btree_inode->i_mapping);
+ }
+ return btrfs_write_and_wait_marked_extents(root,
+ &trans->transaction->dirty_pages);
+}
+
+/*
+ * this is used to update the root pointer in the tree of tree roots.
+ *
+ * But, in the case of the extent allocation tree, updating the root
+ * pointer may allocate blocks which may change the root of the extent
+ * allocation tree.
+ *
+ * So, this loops and repeats and makes sure the cowonly root didn't
+ * change while the root pointer was being updated in the metadata.
+ */
+static int update_cowonly_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ int ret;
+ u64 old_root_bytenr;
+ struct btrfs_root *tree_root = root->fs_info->tree_root;
+
+ btrfs_extent_post_op(trans, root);
+ btrfs_write_dirty_block_groups(trans, root);
+ btrfs_extent_post_op(trans, root);
+
+ while(1) {
+ old_root_bytenr = btrfs_root_bytenr(&root->root_item);
+ if (old_root_bytenr == root->node->start)
+ break;
+ btrfs_set_root_bytenr(&root->root_item,
+ root->node->start);
+ btrfs_set_root_level(&root->root_item,
+ btrfs_header_level(root->node));
+ btrfs_set_root_generation(&root->root_item, trans->transid);
+
+ btrfs_extent_post_op(trans, root);
+
+ ret = btrfs_update_root(trans, tree_root,
+ &root->root_key,
+ &root->root_item);
+ BUG_ON(ret);
+ btrfs_write_dirty_block_groups(trans, root);
+ btrfs_extent_post_op(trans, root);
+ }
+ return 0;
+}
+
+/*
+ * update all the cowonly tree roots on disk
+ */
+int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct list_head *next;
+ struct extent_buffer *eb;
+
+ btrfs_extent_post_op(trans, fs_info->tree_root);
+
+ eb = btrfs_lock_root_node(fs_info->tree_root);
+ btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb, 0);
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+
+ btrfs_extent_post_op(trans, fs_info->tree_root);
+
+ while(!list_empty(&fs_info->dirty_cowonly_roots)) {
+ next = fs_info->dirty_cowonly_roots.next;
+ list_del_init(next);
+ root = list_entry(next, struct btrfs_root, dirty_list);
+
+ update_cowonly_root(trans, root);
+ }
+ return 0;
+}
+
+/*
+ * dead roots are old snapshots that need to be deleted. This allocates
+ * a dirty root struct and adds it into the list of dead roots that need to
+ * be deleted
+ */
+int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest)
+{
+ struct btrfs_dirty_root *dirty;
+
+ dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
+ if (!dirty)
+ return -ENOMEM;
+ dirty->root = root;
+ dirty->latest_root = latest;
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ list_add(&dirty->list, &latest->fs_info->dead_roots);
+ mutex_unlock(&root->fs_info->trans_mutex);
+ return 0;
+}
+
+/*
+ * at transaction commit time we need to schedule the old roots for
+ * deletion via btrfs_drop_snapshot. This runs through all the
+ * reference counted roots that were modified in the current
+ * transaction and puts them into the drop list
+ */
+static noinline int add_dirty_roots(struct btrfs_trans_handle *trans,
+ struct radix_tree_root *radix,
+ struct list_head *list)
+{
+ struct btrfs_dirty_root *dirty;
+ struct btrfs_root *gang[8];
+ struct btrfs_root *root;
+ int i;
+ int ret;
+ int err = 0;
+ u32 refs;
+
+ while(1) {
+ ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
+ ARRAY_SIZE(gang),
+ BTRFS_ROOT_TRANS_TAG);
+ if (ret == 0)
+ break;
+ for (i = 0; i < ret; i++) {
+ root = gang[i];
+ radix_tree_tag_clear(radix,
+ (unsigned long)root->root_key.objectid,
+ BTRFS_ROOT_TRANS_TAG);
+
+ BUG_ON(!root->ref_tree);
+ dirty = root->dirty_root;
+
+ btrfs_free_log(trans, root);
+ btrfs_free_reloc_root(trans, root);
+
+ if (root->commit_root == root->node) {
+ WARN_ON(root->node->start !=
+ btrfs_root_bytenr(&root->root_item));
+
+ free_extent_buffer(root->commit_root);
+ root->commit_root = NULL;
+ root->dirty_root = NULL;
+
+ spin_lock(&root->list_lock);
+ list_del_init(&dirty->root->dead_list);
+ spin_unlock(&root->list_lock);
+
+ kfree(dirty->root);
+ kfree(dirty);
+
+ /* make sure to update the root on disk
+ * so we get any updates to the block used
+ * counts
+ */
+ err = btrfs_update_root(trans,
+ root->fs_info->tree_root,
+ &root->root_key,
+ &root->root_item);
+ continue;
+ }
+
+ memset(&root->root_item.drop_progress, 0,
+ sizeof(struct btrfs_disk_key));
+ root->root_item.drop_level = 0;
+ root->commit_root = NULL;
+ root->dirty_root = NULL;
+ root->root_key.offset = root->fs_info->generation;
+ btrfs_set_root_bytenr(&root->root_item,
+ root->node->start);
+ btrfs_set_root_level(&root->root_item,
+ btrfs_header_level(root->node));
+ btrfs_set_root_generation(&root->root_item,
+ root->root_key.offset);
+
+ err = btrfs_insert_root(trans, root->fs_info->tree_root,
+ &root->root_key,
+ &root->root_item);
+ if (err)
+ break;
+
+ refs = btrfs_root_refs(&dirty->root->root_item);
+ btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
+ err = btrfs_update_root(trans, root->fs_info->tree_root,
+ &dirty->root->root_key,
+ &dirty->root->root_item);
+
+ BUG_ON(err);
+ if (refs == 1) {
+ list_add(&dirty->list, list);
+ } else {
+ WARN_ON(1);
+ free_extent_buffer(dirty->root->node);
+ kfree(dirty->root);
+ kfree(dirty);
+ }
+ }
+ }
+ return err;
+}
+
+/*
+ * defrag a given btree. If cacheonly == 1, this won't read from the disk,
+ * otherwise every leaf in the btree is read and defragged.
+ */
+int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
+{
+ struct btrfs_fs_info *info = root->fs_info;
+ int ret;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr;
+
+ smp_mb();
+ if (root->defrag_running)
+ return 0;
+ trans = btrfs_start_transaction(root, 1);
+ while (1) {
+ root->defrag_running = 1;
+ ret = btrfs_defrag_leaves(trans, root, cacheonly);
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(info->tree_root, nr);
+ cond_resched();
+
+ trans = btrfs_start_transaction(root, 1);
+ if (root->fs_info->closing || ret != -EAGAIN)
+ break;
+ }
+ root->defrag_running = 0;
+ smp_mb();
+ btrfs_end_transaction(trans, root);
+ return 0;
+}
+
+/*
+ * Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
+ * all of them
+ */
+static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
+ struct list_head *list)
+{
+ struct btrfs_dirty_root *dirty;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr;
+ u64 num_bytes;
+ u64 bytes_used;
+ u64 max_useless;
+ int ret = 0;
+ int err;
+
+ while(!list_empty(list)) {
+ struct btrfs_root *root;
+
+ dirty = list_entry(list->prev, struct btrfs_dirty_root, list);
+ list_del_init(&dirty->list);
+
+ num_bytes = btrfs_root_used(&dirty->root->root_item);
+ root = dirty->latest_root;
+ atomic_inc(&root->fs_info->throttles);
+
+ while(1) {
+ trans = btrfs_start_transaction(tree_root, 1);
+ mutex_lock(&root->fs_info->drop_mutex);
+ ret = btrfs_drop_snapshot(trans, dirty->root);
+ if (ret != -EAGAIN) {
+ break;
+ }
+ mutex_unlock(&root->fs_info->drop_mutex);
+
+ err = btrfs_update_root(trans,
+ tree_root,
+ &dirty->root->root_key,
+ &dirty->root->root_item);
+ if (err)
+ ret = err;
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction(trans, tree_root);
+ BUG_ON(ret);
+
+ btrfs_btree_balance_dirty(tree_root, nr);
+ cond_resched();
+ }
+ BUG_ON(ret);
+ atomic_dec(&root->fs_info->throttles);
+ wake_up(&root->fs_info->transaction_throttle);
+
+ num_bytes -= btrfs_root_used(&dirty->root->root_item);
+ bytes_used = btrfs_root_used(&root->root_item);
+ if (num_bytes) {
+ btrfs_record_root_in_trans(root);
+ btrfs_set_root_used(&root->root_item,
+ bytes_used - num_bytes);
+ }
+
+ ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
+ if (ret) {
+ BUG();
+ break;
+ }
+ mutex_unlock(&root->fs_info->drop_mutex);
+
+ spin_lock(&root->list_lock);
+ list_del_init(&dirty->root->dead_list);
+ if (!list_empty(&root->dead_list)) {
+ struct btrfs_root *oldest;
+ oldest = list_entry(root->dead_list.prev,
+ struct btrfs_root, dead_list);
+ max_useless = oldest->root_key.offset - 1;
+ } else {
+ max_useless = root->root_key.offset - 1;
+ }
+ spin_unlock(&root->list_lock);
+
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction(trans, tree_root);
+ BUG_ON(ret);
+
+ ret = btrfs_remove_leaf_refs(root, max_useless, 0);
+ BUG_ON(ret);
+
+ free_extent_buffer(dirty->root->node);
+ kfree(dirty->root);
+ kfree(dirty);
+
+ btrfs_btree_balance_dirty(tree_root, nr);
+ cond_resched();
+ }
+ return ret;
+}
+
+/*
+ * new snapshots need to be created at a very specific time in the
+ * transaction commit. This does the actual creation
+ */
+static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info,
+ struct btrfs_pending_snapshot *pending)
+{
+ struct btrfs_key key;
+ struct btrfs_root_item *new_root_item;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ struct btrfs_root *root = pending->root;
+ struct extent_buffer *tmp;
+ struct extent_buffer *old;
+ int ret;
+ u64 objectid;
+
+ new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
+ if (!new_root_item) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
+ if (ret)
+ goto fail;
+
+ btrfs_record_root_in_trans(root);
+ btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
+ memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
+
+ key.objectid = objectid;
+ key.offset = trans->transid;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+
+ old = btrfs_lock_root_node(root);
+ btrfs_cow_block(trans, root, old, NULL, 0, &old, 0);
+
+ btrfs_copy_root(trans, root, old, &tmp, objectid);
+ btrfs_tree_unlock(old);
+ free_extent_buffer(old);
+
+ btrfs_set_root_bytenr(new_root_item, tmp->start);
+ btrfs_set_root_level(new_root_item, btrfs_header_level(tmp));
+ btrfs_set_root_generation(new_root_item, trans->transid);
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+ new_root_item);
+ btrfs_tree_unlock(tmp);
+ free_extent_buffer(tmp);
+ if (ret)
+ goto fail;
+
+ key.offset = (u64)-1;
+ memcpy(&pending->root_key, &key, sizeof(key));
+fail:
+ kfree(new_root_item);
+ return ret;
+}
+
+static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
+ struct btrfs_pending_snapshot *pending)
+{
+ int ret;
+ int namelen;
+ u64 index = 0;
+ struct btrfs_trans_handle *trans;
+ struct inode *parent_inode;
+ struct inode *inode;
+ struct btrfs_root *parent_root;
+
+ parent_inode = pending->dentry->d_parent->d_inode;
+ parent_root = BTRFS_I(parent_inode)->root;
+ trans = btrfs_start_transaction(parent_root, 1);
+
+ /*
+ * insert the directory item
+ */
+ namelen = strlen(pending->name);
+ ret = btrfs_set_inode_index(parent_inode, &index);
+ ret = btrfs_insert_dir_item(trans, parent_root,
+ pending->name, namelen,
+ parent_inode->i_ino,
+ &pending->root_key, BTRFS_FT_DIR, index);
+
+ if (ret)
+ goto fail;
+
+ /* add the backref first */
+ ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
+ pending->root_key.objectid,
+ BTRFS_ROOT_BACKREF_KEY,
+ parent_root->root_key.objectid,
+ parent_inode->i_ino, index, pending->name,
+ namelen);
+
+ BUG_ON(ret);
+
+ /* now add the forward ref */
+ ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
+ parent_root->root_key.objectid,
+ BTRFS_ROOT_REF_KEY,
+ pending->root_key.objectid,
+ parent_inode->i_ino, index, pending->name,
+ namelen);
+
+ inode = btrfs_lookup_dentry(parent_inode, pending->dentry);
+ d_instantiate(pending->dentry, inode);
+fail:
+ btrfs_end_transaction(trans, fs_info->fs_root);
+ return ret;
+}
+
+/*
+ * create all the snapshots we've scheduled for creation
+ */
+static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_pending_snapshot *pending;
+ struct list_head *head = &trans->transaction->pending_snapshots;
+ struct list_head *cur;
+ int ret;
+
+ list_for_each(cur, head) {
+ pending = list_entry(cur, struct btrfs_pending_snapshot, list);
+ ret = create_pending_snapshot(trans, fs_info, pending);
+ BUG_ON(ret);
+ }
+ return 0;
+}
+
+static noinline int finish_pending_snapshots(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_pending_snapshot *pending;
+ struct list_head *head = &trans->transaction->pending_snapshots;
+ int ret;
+
+ while(!list_empty(head)) {
+ pending = list_entry(head->next,
+ struct btrfs_pending_snapshot, list);
+ ret = finish_pending_snapshot(fs_info, pending);
+ BUG_ON(ret);
+ list_del(&pending->list);
+ kfree(pending->name);
+ kfree(pending);
+ }
+ return 0;
+}
+
+int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ unsigned long joined = 0;
+ unsigned long timeout = 1;
+ struct btrfs_transaction *cur_trans;
+ struct btrfs_transaction *prev_trans = NULL;
+ struct btrfs_root *chunk_root = root->fs_info->chunk_root;
+ struct list_head dirty_fs_roots;
+ struct extent_io_tree *pinned_copy;
+ DEFINE_WAIT(wait);
+ int ret;
+
+ INIT_LIST_HEAD(&dirty_fs_roots);
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (trans->transaction->in_commit) {
+ cur_trans = trans->transaction;
+ trans->transaction->use_count++;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ btrfs_end_transaction(trans, root);
+
+ ret = wait_for_commit(root, cur_trans);
+ BUG_ON(ret);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ put_transaction(cur_trans);
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ return 0;
+ }
+
+ pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
+ if (!pinned_copy)
+ return -ENOMEM;
+
+ extent_io_tree_init(pinned_copy,
+ root->fs_info->btree_inode->i_mapping, GFP_NOFS);
+
+ trans->transaction->in_commit = 1;
+ trans->transaction->blocked = 1;
+ cur_trans = trans->transaction;
+ if (cur_trans->list.prev != &root->fs_info->trans_list) {
+ prev_trans = list_entry(cur_trans->list.prev,
+ struct btrfs_transaction, list);
+ if (!prev_trans->commit_done) {
+ prev_trans->use_count++;
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ wait_for_commit(root, prev_trans);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ put_transaction(prev_trans);
+ }
+ }
+
+ do {
+ int snap_pending = 0;
+ joined = cur_trans->num_joined;
+ if (!list_empty(&trans->transaction->pending_snapshots))
+ snap_pending = 1;
+
+ WARN_ON(cur_trans != trans->transaction);
+ prepare_to_wait(&cur_trans->writer_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+
+ if (cur_trans->num_writers > 1)
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ else
+ timeout = 1;
+
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ if (snap_pending) {
+ ret = btrfs_wait_ordered_extents(root, 1);
+ BUG_ON(ret);
+ }
+
+ schedule_timeout(timeout);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ finish_wait(&cur_trans->writer_wait, &wait);
+ } while (cur_trans->num_writers > 1 ||
+ (cur_trans->num_joined != joined));
+
+ ret = create_pending_snapshots(trans, root->fs_info);
+ BUG_ON(ret);
+
+ WARN_ON(cur_trans != trans->transaction);
+
+ /* btrfs_commit_tree_roots is responsible for getting the
+ * various roots consistent with each other. Every pointer
+ * in the tree of tree roots has to point to the most up to date
+ * root for every subvolume and other tree. So, we have to keep
+ * the tree logging code from jumping in and changing any
+ * of the trees.
+ *
+ * At this point in the commit, there can't be any tree-log
+ * writers, but a little lower down we drop the trans mutex
+ * and let new people in. By holding the tree_log_mutex
+ * from now until after the super is written, we avoid races
+ * with the tree-log code.
+ */
+ mutex_lock(&root->fs_info->tree_log_mutex);
+ /*
+ * keep tree reloc code from adding new reloc trees
+ */
+ mutex_lock(&root->fs_info->tree_reloc_mutex);
+
+
+ ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
+ &dirty_fs_roots);
+ BUG_ON(ret);
+
+ /* add_dirty_roots gets rid of all the tree log roots, it is now
+ * safe to free the root of tree log roots
+ */
+ btrfs_free_log_root_tree(trans, root->fs_info);
+
+ ret = btrfs_commit_tree_roots(trans, root);
+ BUG_ON(ret);
+
+ cur_trans = root->fs_info->running_transaction;
+ spin_lock(&root->fs_info->new_trans_lock);
+ root->fs_info->running_transaction = NULL;
+ spin_unlock(&root->fs_info->new_trans_lock);
+ btrfs_set_super_generation(&root->fs_info->super_copy,
+ cur_trans->transid);
+ btrfs_set_super_root(&root->fs_info->super_copy,
+ root->fs_info->tree_root->node->start);
+ btrfs_set_super_root_level(&root->fs_info->super_copy,
+ btrfs_header_level(root->fs_info->tree_root->node));
+
+ btrfs_set_super_chunk_root(&root->fs_info->super_copy,
+ chunk_root->node->start);
+ btrfs_set_super_chunk_root_level(&root->fs_info->super_copy,
+ btrfs_header_level(chunk_root->node));
+ btrfs_set_super_chunk_root_generation(&root->fs_info->super_copy,
+ btrfs_header_generation(chunk_root->node));
+
+ if (!root->fs_info->log_root_recovering) {
+ btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
+ btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0);
+ }
+
+ memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
+ sizeof(root->fs_info->super_copy));
+
+ btrfs_copy_pinned(root, pinned_copy);
+
+ trans->transaction->blocked = 0;
+ wake_up(&root->fs_info->transaction_throttle);
+ wake_up(&root->fs_info->transaction_wait);
+
+ mutex_unlock(&root->fs_info->trans_mutex);
+ ret = btrfs_write_and_wait_transaction(trans, root);
+ BUG_ON(ret);
+ write_ctree_super(trans, root);
+
+ /*
+ * the super is written, we can safely allow the tree-loggers
+ * to go about their business
+ */
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+
+ btrfs_finish_extent_commit(trans, root, pinned_copy);
+ kfree(pinned_copy);
+
+ btrfs_drop_dead_reloc_roots(root);
+ mutex_unlock(&root->fs_info->tree_reloc_mutex);
+
+ /* do the directory inserts of any pending snapshot creations */
+ finish_pending_snapshots(trans, root->fs_info);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+
+ cur_trans->commit_done = 1;
+ root->fs_info->last_trans_committed = cur_trans->transid;
+ wake_up(&cur_trans->commit_wait);
+
+ put_transaction(cur_trans);
+ put_transaction(cur_trans);
+
+ list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
+ if (root->fs_info->closing)
+ list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
+
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ kmem_cache_free(btrfs_trans_handle_cachep, trans);
+
+ if (root->fs_info->closing) {
+ drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
+ }
+ return ret;
+}
+
+/*
+ * interface function to delete all the snapshots we have scheduled for deletion
+ */
+int btrfs_clean_old_snapshots(struct btrfs_root *root)
+{
+ struct list_head dirty_roots;
+ INIT_LIST_HEAD(&dirty_roots);
+again:
+ mutex_lock(&root->fs_info->trans_mutex);
+ list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ if (!list_empty(&dirty_roots)) {
+ drop_dirty_roots(root, &dirty_roots);
+ goto again;
+ }
+ return 0;
+}
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
new file mode 100644
index 0000000..202c8be
--- /dev/null
+++ b/fs/btrfs/transaction.h
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_TRANSACTION__
+#define __BTRFS_TRANSACTION__
+#include "btrfs_inode.h"
+
+struct btrfs_transaction {
+ u64 transid;
+ unsigned long num_writers;
+ unsigned long num_joined;
+ int in_commit;
+ int use_count;
+ int commit_done;
+ int blocked;
+ struct list_head list;
+ struct extent_io_tree dirty_pages;
+ unsigned long start_time;
+ wait_queue_head_t writer_wait;
+ wait_queue_head_t commit_wait;
+ struct list_head pending_snapshots;
+};
+
+struct btrfs_trans_handle {
+ u64 transid;
+ unsigned long blocks_reserved;
+ unsigned long blocks_used;
+ struct btrfs_transaction *transaction;
+ struct btrfs_block_group_cache *block_group;
+ u64 alloc_exclude_start;
+ u64 alloc_exclude_nr;
+};
+
+struct btrfs_pending_snapshot {
+ struct dentry *dentry;
+ struct btrfs_root *root;
+ char *name;
+ struct btrfs_key root_key;
+ struct list_head list;
+};
+
+struct btrfs_dirty_root {
+ struct list_head list;
+ struct btrfs_root *root;
+ struct btrfs_root *latest_root;
+};
+
+static inline void btrfs_set_trans_block_group(struct btrfs_trans_handle *trans,
+ struct inode *inode)
+{
+ trans->block_group = BTRFS_I(inode)->block_group;
+}
+
+static inline void btrfs_update_inode_block_group(struct
+ btrfs_trans_handle *trans,
+ struct inode *inode)
+{
+ BTRFS_I(inode)->block_group = trans->block_group;
+}
+
+static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
+ struct inode *inode)
+{
+ BTRFS_I(inode)->last_trans = trans->transaction->transid;
+}
+
+int btrfs_end_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
+ int num_blocks);
+struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
+ int num_blocks);
+struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
+ int num_blocks);
+int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+
+int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest);
+int btrfs_defrag_root(struct btrfs_root *root, int cacheonly);
+int btrfs_clean_old_snapshots(struct btrfs_root *root);
+int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+void btrfs_throttle(struct btrfs_root *root);
+int btrfs_record_root_in_trans(struct btrfs_root *root);
+int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
+ struct extent_io_tree *dirty_pages);
+#endif
diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
new file mode 100644
index 0000000..a6a3956
--- /dev/null
+++ b/fs/btrfs/tree-defrag.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "transaction.h"
+#include "locking.h"
+
+/* defrag all the leaves in a given btree. If cache_only == 1, don't read things
+ * from disk, otherwise read all the leaves and try to get key order to
+ * better reflect disk order
+ */
+int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, int cache_only)
+{
+ struct btrfs_path *path = NULL;
+ struct btrfs_key key;
+ int ret = 0;
+ int wret;
+ int level;
+ int orig_level;
+ int is_extent = 0;
+ int next_key_ret = 0;
+ u64 last_ret = 0;
+ u64 min_trans = 0;
+
+ if (cache_only)
+ goto out;
+
+ if (root->fs_info->extent_root == root) {
+ /*
+ * there's recursion here right now in the tree locking,
+ * we can't defrag the extent root without deadlock
+ */
+ goto out;
+ }
+
+ if (root->ref_cows == 0 && !is_extent)
+ goto out;
+
+ if (btrfs_test_opt(root, SSD))
+ goto out;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ level = btrfs_header_level(root->node);
+ orig_level = level;
+
+ if (level == 0) {
+ goto out;
+ }
+ if (root->defrag_progress.objectid == 0) {
+ struct extent_buffer *root_node;
+ u32 nritems;
+
+ root_node = btrfs_lock_root_node(root);
+ nritems = btrfs_header_nritems(root_node);
+ root->defrag_max.objectid = 0;
+ /* from above we know this is not a leaf */
+ btrfs_node_key_to_cpu(root_node, &root->defrag_max,
+ nritems - 1);
+ btrfs_tree_unlock(root_node);
+ free_extent_buffer(root_node);
+ memset(&key, 0, sizeof(key));
+ } else {
+ memcpy(&key, &root->defrag_progress, sizeof(key));
+ }
+
+ path->keep_locks = 1;
+ if (cache_only)
+ min_trans = root->defrag_trans_start;
+
+ ret = btrfs_search_forward(root, &key, NULL, path,
+ cache_only, min_trans);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ btrfs_release_path(root, path);
+ wret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+
+ if (wret < 0) {
+ ret = wret;
+ goto out;
+ }
+ if (!path->nodes[1]) {
+ ret = 0;
+ goto out;
+ }
+ path->slots[1] = btrfs_header_nritems(path->nodes[1]);
+ next_key_ret = btrfs_find_next_key(root, path, &key, 1, cache_only,
+ min_trans);
+ ret = btrfs_realloc_node(trans, root,
+ path->nodes[1], 0,
+ cache_only, &last_ret,
+ &root->defrag_progress);
+ WARN_ON(ret && ret != -EAGAIN);
+ if (next_key_ret == 0) {
+ memcpy(&root->defrag_progress, &key, sizeof(key));
+ ret = -EAGAIN;
+ }
+
+ btrfs_release_path(root, path);
+ if (is_extent)
+ btrfs_extent_post_op(trans, root);
+out:
+ if (path)
+ btrfs_free_path(path);
+ if (ret == -EAGAIN) {
+ if (root->defrag_max.objectid > root->defrag_progress.objectid)
+ goto done;
+ if (root->defrag_max.type > root->defrag_progress.type)
+ goto done;
+ if (root->defrag_max.offset > root->defrag_progress.offset)
+ goto done;
+ ret = 0;
+ }
+done:
+ if (ret != -EAGAIN) {
+ memset(&root->defrag_progress, 0,
+ sizeof(root->defrag_progress));
+ root->defrag_trans_start = trans->transid;
+ }
+ return ret;
+}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
new file mode 100644
index 0000000..be4fc30
--- /dev/null
+++ b/fs/btrfs/tree-log.c
@@ -0,0 +1,2896 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include "ctree.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "locking.h"
+#include "print-tree.h"
+#include "compat.h"
+
+/* magic values for the inode_only field in btrfs_log_inode:
+ *
+ * LOG_INODE_ALL means to log everything
+ * LOG_INODE_EXISTS means to log just enough to recreate the inode
+ * during log replay
+ */
+#define LOG_INODE_ALL 0
+#define LOG_INODE_EXISTS 1
+
+/*
+ * stages for the tree walking. The first
+ * stage (0) is to only pin down the blocks we find
+ * the second stage (1) is to make sure that all the inodes
+ * we find in the log are created in the subvolume.
+ *
+ * The last stage is to deal with directories and links and extents
+ * and all the other fun semantics
+ */
+#define LOG_WALK_PIN_ONLY 0
+#define LOG_WALK_REPLAY_INODES 1
+#define LOG_WALK_REPLAY_ALL 2
+
+static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ int inode_only);
+
+/*
+ * tree logging is a special write ahead log used to make sure that
+ * fsyncs and O_SYNCs can happen without doing full tree commits.
+ *
+ * Full tree commits are expensive because they require commonly
+ * modified blocks to be recowed, creating many dirty pages in the
+ * extent tree an 4x-6x higher write load than ext3.
+ *
+ * Instead of doing a tree commit on every fsync, we use the
+ * key ranges and transaction ids to find items for a given file or directory
+ * that have changed in this transaction. Those items are copied into
+ * a special tree (one per subvolume root), that tree is written to disk
+ * and then the fsync is considered complete.
+ *
+ * After a crash, items are copied out of the log-tree back into the
+ * subvolume tree. Any file data extents found are recorded in the extent
+ * allocation tree, and the log-tree freed.
+ *
+ * The log tree is read three times, once to pin down all the extents it is
+ * using in ram and once, once to create all the inodes logged in the tree
+ * and once to do all the other items.
+ */
+
+/*
+ * btrfs_add_log_tree adds a new per-subvolume log tree into the
+ * tree of log tree roots. This must be called with a tree log transaction
+ * running (see start_log_trans).
+ */
+int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_key key;
+ struct btrfs_root_item root_item;
+ struct btrfs_inode_item *inode_item;
+ struct extent_buffer *leaf;
+ struct btrfs_root *new_root = root;
+ int ret;
+ u64 objectid = root->root_key.objectid;
+
+ leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
+ BTRFS_TREE_LOG_OBJECTID,
+ trans->transid, 0, 0, 0);
+ if (IS_ERR(leaf)) {
+ ret = PTR_ERR(leaf);
+ return ret;
+ }
+
+ btrfs_set_header_nritems(leaf, 0);
+ btrfs_set_header_level(leaf, 0);
+ btrfs_set_header_bytenr(leaf, leaf->start);
+ btrfs_set_header_generation(leaf, trans->transid);
+ btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
+
+ write_extent_buffer(leaf, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(leaf),
+ BTRFS_FSID_SIZE);
+ btrfs_mark_buffer_dirty(leaf);
+
+ inode_item = &root_item.inode;
+ memset(inode_item, 0, sizeof(*inode_item));
+ inode_item->generation = cpu_to_le64(1);
+ inode_item->size = cpu_to_le64(3);
+ inode_item->nlink = cpu_to_le32(1);
+ inode_item->nbytes = cpu_to_le64(root->leafsize);
+ inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
+
+ btrfs_set_root_bytenr(&root_item, leaf->start);
+ btrfs_set_root_generation(&root_item, trans->transid);
+ btrfs_set_root_level(&root_item, 0);
+ btrfs_set_root_refs(&root_item, 0);
+ btrfs_set_root_used(&root_item, 0);
+
+ memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
+ root_item.drop_level = 0;
+
+ btrfs_tree_unlock(leaf);
+ free_extent_buffer(leaf);
+ leaf = NULL;
+
+ btrfs_set_root_dirid(&root_item, 0);
+
+ key.objectid = BTRFS_TREE_LOG_OBJECTID;
+ key.offset = objectid;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key,
+ &root_item);
+ if (ret)
+ goto fail;
+
+ new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree,
+ &key);
+ BUG_ON(!new_root);
+
+ WARN_ON(root->log_root);
+ root->log_root = new_root;
+
+ /*
+ * log trees do not get reference counted because they go away
+ * before a real commit is actually done. They do store pointers
+ * to file data extents, and those reference counts still get
+ * updated (along with back refs to the log tree).
+ */
+ new_root->ref_cows = 0;
+ new_root->last_trans = trans->transid;
+fail:
+ return ret;
+}
+
+/*
+ * start a sub transaction and setup the log tree
+ * this increments the log tree writer count to make the people
+ * syncing the tree wait for us to finish
+ */
+static int start_log_trans(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ int ret;
+ mutex_lock(&root->fs_info->tree_log_mutex);
+ if (!root->fs_info->log_root_tree) {
+ ret = btrfs_init_log_root_tree(trans, root->fs_info);
+ BUG_ON(ret);
+ }
+ if (!root->log_root) {
+ ret = btrfs_add_log_tree(trans, root);
+ BUG_ON(ret);
+ }
+ atomic_inc(&root->fs_info->tree_log_writers);
+ root->fs_info->tree_log_batch++;
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+ return 0;
+}
+
+/*
+ * returns 0 if there was a log transaction running and we were able
+ * to join, or returns -ENOENT if there were not transactions
+ * in progress
+ */
+static int join_running_log_trans(struct btrfs_root *root)
+{
+ int ret = -ENOENT;
+
+ smp_mb();
+ if (!root->log_root)
+ return -ENOENT;
+
+ mutex_lock(&root->fs_info->tree_log_mutex);
+ if (root->log_root) {
+ ret = 0;
+ atomic_inc(&root->fs_info->tree_log_writers);
+ root->fs_info->tree_log_batch++;
+ }
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+ return ret;
+}
+
+/*
+ * indicate we're done making changes to the log tree
+ * and wake up anyone waiting to do a sync
+ */
+static int end_log_trans(struct btrfs_root *root)
+{
+ atomic_dec(&root->fs_info->tree_log_writers);
+ smp_mb();
+ if (waitqueue_active(&root->fs_info->tree_log_wait))
+ wake_up(&root->fs_info->tree_log_wait);
+ return 0;
+}
+
+
+/*
+ * the walk control struct is used to pass state down the chain when
+ * processing the log tree. The stage field tells us which part
+ * of the log tree processing we are currently doing. The others
+ * are state fields used for that specific part
+ */
+struct walk_control {
+ /* should we free the extent on disk when done? This is used
+ * at transaction commit time while freeing a log tree
+ */
+ int free;
+
+ /* should we write out the extent buffer? This is used
+ * while flushing the log tree to disk during a sync
+ */
+ int write;
+
+ /* should we wait for the extent buffer io to finish? Also used
+ * while flushing the log tree to disk for a sync
+ */
+ int wait;
+
+ /* pin only walk, we record which extents on disk belong to the
+ * log trees
+ */
+ int pin;
+
+ /* what stage of the replay code we're currently in */
+ int stage;
+
+ /* the root we are currently replaying */
+ struct btrfs_root *replay_dest;
+
+ /* the trans handle for the current replay */
+ struct btrfs_trans_handle *trans;
+
+ /* the function that gets used to process blocks we find in the
+ * tree. Note the extent_buffer might not be up to date when it is
+ * passed in, and it must be checked or read if you need the data
+ * inside it
+ */
+ int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen);
+};
+
+/*
+ * process_func used to pin down extents, write them or wait on them
+ */
+static int process_one_buffer(struct btrfs_root *log,
+ struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen)
+{
+ if (wc->pin) {
+ mutex_lock(&log->fs_info->pinned_mutex);
+ btrfs_update_pinned_extents(log->fs_info->extent_root,
+ eb->start, eb->len, 1);
+ mutex_unlock(&log->fs_info->pinned_mutex);
+ }
+
+ if (btrfs_buffer_uptodate(eb, gen)) {
+ if (wc->write)
+ btrfs_write_tree_block(eb);
+ if (wc->wait)
+ btrfs_wait_tree_block_writeback(eb);
+ }
+ return 0;
+}
+
+/*
+ * Item overwrite used by replay and tree logging. eb, slot and key all refer
+ * to the src data we are copying out.
+ *
+ * root is the tree we are copying into, and path is a scratch
+ * path for use in this function (it should be released on entry and
+ * will be released on exit).
+ *
+ * If the key is already in the destination tree the existing item is
+ * overwritten. If the existing item isn't big enough, it is extended.
+ * If it is too large, it is truncated.
+ *
+ * If the key isn't in the destination yet, a new item is inserted.
+ */
+static noinline int overwrite_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int ret;
+ u32 item_size;
+ u64 saved_i_size = 0;
+ int save_old_i_size = 0;
+ unsigned long src_ptr;
+ unsigned long dst_ptr;
+ int overwrite_root = 0;
+
+ if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ overwrite_root = 1;
+
+ item_size = btrfs_item_size_nr(eb, slot);
+ src_ptr = btrfs_item_ptr_offset(eb, slot);
+
+ /* look for the key in the destination tree */
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret == 0) {
+ char *src_copy;
+ char *dst_copy;
+ u32 dst_size = btrfs_item_size_nr(path->nodes[0],
+ path->slots[0]);
+ if (dst_size != item_size)
+ goto insert;
+
+ if (item_size == 0) {
+ btrfs_release_path(root, path);
+ return 0;
+ }
+ dst_copy = kmalloc(item_size, GFP_NOFS);
+ src_copy = kmalloc(item_size, GFP_NOFS);
+
+ read_extent_buffer(eb, src_copy, src_ptr, item_size);
+
+ dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+ read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
+ item_size);
+ ret = memcmp(dst_copy, src_copy, item_size);
+
+ kfree(dst_copy);
+ kfree(src_copy);
+ /*
+ * they have the same contents, just return, this saves
+ * us from cowing blocks in the destination tree and doing
+ * extra writes that may not have been done by a previous
+ * sync
+ */
+ if (ret == 0) {
+ btrfs_release_path(root, path);
+ return 0;
+ }
+
+ }
+insert:
+ btrfs_release_path(root, path);
+ /* try to insert the key into the destination tree */
+ ret = btrfs_insert_empty_item(trans, root, path,
+ key, item_size);
+
+ /* make sure any existing item is the correct size */
+ if (ret == -EEXIST) {
+ u32 found_size;
+ found_size = btrfs_item_size_nr(path->nodes[0],
+ path->slots[0]);
+ if (found_size > item_size) {
+ btrfs_truncate_item(trans, root, path, item_size, 1);
+ } else if (found_size < item_size) {
+ ret = btrfs_del_item(trans, root,
+ path);
+ BUG_ON(ret);
+
+ btrfs_release_path(root, path);
+ ret = btrfs_insert_empty_item(trans,
+ root, path, key, item_size);
+ BUG_ON(ret);
+ }
+ } else if (ret) {
+ BUG();
+ }
+ dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
+ path->slots[0]);
+
+ /* don't overwrite an existing inode if the generation number
+ * was logged as zero. This is done when the tree logging code
+ * is just logging an inode to make sure it exists after recovery.
+ *
+ * Also, don't overwrite i_size on directories during replay.
+ * log replay inserts and removes directory items based on the
+ * state of the tree found in the subvolume, and i_size is modified
+ * as it goes
+ */
+ if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
+ struct btrfs_inode_item *src_item;
+ struct btrfs_inode_item *dst_item;
+
+ src_item = (struct btrfs_inode_item *)src_ptr;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+
+ if (btrfs_inode_generation(eb, src_item) == 0)
+ goto no_copy;
+
+ if (overwrite_root &&
+ S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
+ S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
+ save_old_i_size = 1;
+ saved_i_size = btrfs_inode_size(path->nodes[0],
+ dst_item);
+ }
+ }
+
+ copy_extent_buffer(path->nodes[0], eb, dst_ptr,
+ src_ptr, item_size);
+
+ if (save_old_i_size) {
+ struct btrfs_inode_item *dst_item;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+ btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
+ }
+
+ /* make sure the generation is filled in */
+ if (key->type == BTRFS_INODE_ITEM_KEY) {
+ struct btrfs_inode_item *dst_item;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+ if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
+ btrfs_set_inode_generation(path->nodes[0], dst_item,
+ trans->transid);
+ }
+ }
+
+ if (overwrite_root &&
+ key->type == BTRFS_EXTENT_DATA_KEY) {
+ int extent_type;
+ struct btrfs_file_extent_item *fi;
+
+ fi = (struct btrfs_file_extent_item *)dst_ptr;
+ extent_type = btrfs_file_extent_type(path->nodes[0], fi);
+ if (extent_type == BTRFS_FILE_EXTENT_REG ||
+ extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ struct btrfs_key ins;
+ ins.objectid = btrfs_file_extent_disk_bytenr(
+ path->nodes[0], fi);
+ ins.offset = btrfs_file_extent_disk_num_bytes(
+ path->nodes[0], fi);
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+
+ /*
+ * is this extent already allocated in the extent
+ * allocation tree? If so, just add a reference
+ */
+ ret = btrfs_lookup_extent(root, ins.objectid,
+ ins.offset);
+ if (ret == 0) {
+ ret = btrfs_inc_extent_ref(trans, root,
+ ins.objectid, ins.offset,
+ path->nodes[0]->start,
+ root->root_key.objectid,
+ trans->transid, key->objectid);
+ } else {
+ /*
+ * insert the extent pointer in the extent
+ * allocation tree
+ */
+ ret = btrfs_alloc_logged_extent(trans, root,
+ path->nodes[0]->start,
+ root->root_key.objectid,
+ trans->transid, key->objectid,
+ &ins);
+ BUG_ON(ret);
+ }
+ }
+ }
+no_copy:
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(root, path);
+ return 0;
+}
+
+/*
+ * simple helper to read an inode off the disk from a given root
+ * This can only be called for subvolume roots and not for the log
+ */
+static noinline struct inode *read_one_inode(struct btrfs_root *root,
+ u64 objectid)
+{
+ struct inode *inode;
+ inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
+ if (inode->i_state & I_NEW) {
+ BTRFS_I(inode)->root = root;
+ BTRFS_I(inode)->location.objectid = objectid;
+ BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->location.offset = 0;
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+
+ }
+ if (is_bad_inode(inode)) {
+ iput(inode);
+ inode = NULL;
+ }
+ return inode;
+}
+
+/* replays a single extent in 'eb' at 'slot' with 'key' into the
+ * subvolume 'root'. path is released on entry and should be released
+ * on exit.
+ *
+ * extents in the log tree have not been allocated out of the extent
+ * tree yet. So, this completes the allocation, taking a reference
+ * as required if the extent already exists or creating a new extent
+ * if it isn't in the extent allocation tree yet.
+ *
+ * The extent is inserted into the file, dropping any existing extents
+ * from the file that overlap the new one.
+ */
+static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int found_type;
+ u64 mask = root->sectorsize - 1;
+ u64 extent_end;
+ u64 alloc_hint;
+ u64 start = key->offset;
+ struct btrfs_file_extent_item *item;
+ struct inode *inode = NULL;
+ unsigned long size;
+ int ret = 0;
+
+ item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(eb, item);
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC)
+ extent_end = start + btrfs_file_extent_num_bytes(eb, item);
+ else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ size = btrfs_file_extent_inline_len(eb, item);
+ extent_end = (start + size + mask) & ~mask;
+ } else {
+ ret = 0;
+ goto out;
+ }
+
+ inode = read_one_inode(root, key->objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ /*
+ * first check to see if we already have this extent in the
+ * file. This must be done before the btrfs_drop_extents run
+ * so we don't try to drop this extent.
+ */
+ ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
+ start, 0);
+
+ if (ret == 0 &&
+ (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
+ struct btrfs_file_extent_item cmp1;
+ struct btrfs_file_extent_item cmp2;
+ struct btrfs_file_extent_item *existing;
+ struct extent_buffer *leaf;
+
+ leaf = path->nodes[0];
+ existing = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+
+ read_extent_buffer(eb, &cmp1, (unsigned long)item,
+ sizeof(cmp1));
+ read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
+ sizeof(cmp2));
+
+ /*
+ * we already have a pointer to this exact extent,
+ * we don't have to do anything
+ */
+ if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
+ btrfs_release_path(root, path);
+ goto out;
+ }
+ }
+ btrfs_release_path(root, path);
+
+ /* drop any overlapping extents */
+ ret = btrfs_drop_extents(trans, root, inode,
+ start, extent_end, start, &alloc_hint);
+ BUG_ON(ret);
+
+ /* insert the extent */
+ ret = overwrite_item(trans, root, path, eb, slot, key);
+ BUG_ON(ret);
+
+ /* btrfs_drop_extents changes i_bytes & i_blocks, update it here */
+ inode_add_bytes(inode, extent_end - start);
+ btrfs_update_inode(trans, root, inode);
+out:
+ if (inode)
+ iput(inode);
+ return ret;
+}
+
+/*
+ * when cleaning up conflicts between the directory names in the
+ * subvolume, directory names in the log and directory names in the
+ * inode back references, we may have to unlink inodes from directories.
+ *
+ * This is a helper function to do the unlink of a specific directory
+ * item
+ */
+static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct inode *dir,
+ struct btrfs_dir_item *di)
+{
+ struct inode *inode;
+ char *name;
+ int name_len;
+ struct extent_buffer *leaf;
+ struct btrfs_key location;
+ int ret;
+
+ leaf = path->nodes[0];
+
+ btrfs_dir_item_key_to_cpu(leaf, di, &location);
+ name_len = btrfs_dir_name_len(leaf, di);
+ name = kmalloc(name_len, GFP_NOFS);
+ read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
+ btrfs_release_path(root, path);
+
+ inode = read_one_inode(root, location.objectid);
+ BUG_ON(!inode);
+
+ btrfs_inc_nlink(inode);
+ ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
+ kfree(name);
+
+ iput(inode);
+ return ret;
+}
+
+/*
+ * helper function to see if a given name and sequence number found
+ * in an inode back reference are already in a directory and correctly
+ * point to this inode
+ */
+static noinline int inode_in_dir(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 dirid, u64 objectid, u64 index,
+ const char *name, int name_len)
+{
+ struct btrfs_dir_item *di;
+ struct btrfs_key location;
+ int match = 0;
+
+ di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
+ index, name, name_len, 0);
+ if (di && !IS_ERR(di)) {
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+ if (location.objectid != objectid)
+ goto out;
+ } else
+ goto out;
+ btrfs_release_path(root, path);
+
+ di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
+ if (di && !IS_ERR(di)) {
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+ if (location.objectid != objectid)
+ goto out;
+ } else
+ goto out;
+ match = 1;
+out:
+ btrfs_release_path(root, path);
+ return match;
+}
+
+/*
+ * helper function to check a log tree for a named back reference in
+ * an inode. This is used to decide if a back reference that is
+ * found in the subvolume conflicts with what we find in the log.
+ *
+ * inode backreferences may have multiple refs in a single item,
+ * during replay we process one reference at a time, and we don't
+ * want to delete valid links to a file from the subvolume if that
+ * link is also in the log.
+ */
+static noinline int backref_in_log(struct btrfs_root *log,
+ struct btrfs_key *key,
+ char *name, int namelen)
+{
+ struct btrfs_path *path;
+ struct btrfs_inode_ref *ref;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ unsigned long name_ptr;
+ int found_name_len;
+ int item_size;
+ int ret;
+ int match = 0;
+
+ path = btrfs_alloc_path();
+ ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
+ if (ret != 0)
+ goto out;
+
+ item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+ ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+ ptr_end = ptr + item_size;
+ while (ptr < ptr_end) {
+ ref = (struct btrfs_inode_ref *)ptr;
+ found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
+ if (found_name_len == namelen) {
+ name_ptr = (unsigned long)(ref + 1);
+ ret = memcmp_extent_buffer(path->nodes[0], name,
+ name_ptr, namelen);
+ if (ret == 0) {
+ match = 1;
+ goto out;
+ }
+ }
+ ptr = (unsigned long)(ref + 1) + found_name_len;
+ }
+out:
+ btrfs_free_path(path);
+ return match;
+}
+
+
+/*
+ * replay one inode back reference item found in the log tree.
+ * eb, slot and key refer to the buffer and key found in the log tree.
+ * root is the destination we are replaying into, and path is for temp
+ * use by this function. (it should be released on return).
+ */
+static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ struct inode *dir;
+ int ret;
+ struct btrfs_key location;
+ struct btrfs_inode_ref *ref;
+ struct btrfs_dir_item *di;
+ struct inode *inode;
+ char *name;
+ int namelen;
+ unsigned long ref_ptr;
+ unsigned long ref_end;
+
+ location.objectid = key->objectid;
+ location.type = BTRFS_INODE_ITEM_KEY;
+ location.offset = 0;
+
+ /*
+ * it is possible that we didn't log all the parent directories
+ * for a given inode. If we don't find the dir, just don't
+ * copy the back ref in. The link count fixup code will take
+ * care of the rest
+ */
+ dir = read_one_inode(root, key->offset);
+ if (!dir)
+ return -ENOENT;
+
+ inode = read_one_inode(root, key->objectid);
+ BUG_ON(!dir);
+
+ ref_ptr = btrfs_item_ptr_offset(eb, slot);
+ ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
+
+again:
+ ref = (struct btrfs_inode_ref *)ref_ptr;
+
+ namelen = btrfs_inode_ref_name_len(eb, ref);
+ name = kmalloc(namelen, GFP_NOFS);
+ BUG_ON(!name);
+
+ read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
+
+ /* if we already have a perfect match, we're done */
+ if (inode_in_dir(root, path, dir->i_ino, inode->i_ino,
+ btrfs_inode_ref_index(eb, ref),
+ name, namelen)) {
+ goto out;
+ }
+
+ /*
+ * look for a conflicting back reference in the metadata.
+ * if we find one we have to unlink that name of the file
+ * before we add our new link. Later on, we overwrite any
+ * existing back reference, and we don't want to create
+ * dangling pointers in the directory.
+ */
+conflict_again:
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret == 0) {
+ char *victim_name;
+ int victim_name_len;
+ struct btrfs_inode_ref *victim_ref;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ struct extent_buffer *leaf = path->nodes[0];
+
+ /* are we trying to overwrite a back ref for the root directory
+ * if so, just jump out, we're done
+ */
+ if (key->objectid == key->offset)
+ goto out_nowrite;
+
+ /* check all the names in this back reference to see
+ * if they are in the log. if so, we allow them to stay
+ * otherwise they must be unlinked as a conflict
+ */
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
+ while(ptr < ptr_end) {
+ victim_ref = (struct btrfs_inode_ref *)ptr;
+ victim_name_len = btrfs_inode_ref_name_len(leaf,
+ victim_ref);
+ victim_name = kmalloc(victim_name_len, GFP_NOFS);
+ BUG_ON(!victim_name);
+
+ read_extent_buffer(leaf, victim_name,
+ (unsigned long)(victim_ref + 1),
+ victim_name_len);
+
+ if (!backref_in_log(log, key, victim_name,
+ victim_name_len)) {
+ btrfs_inc_nlink(inode);
+ btrfs_release_path(root, path);
+ ret = btrfs_unlink_inode(trans, root, dir,
+ inode, victim_name,
+ victim_name_len);
+ kfree(victim_name);
+ btrfs_release_path(root, path);
+ goto conflict_again;
+ }
+ kfree(victim_name);
+ ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
+ }
+ BUG_ON(ret);
+ }
+ btrfs_release_path(root, path);
+
+ /* look for a conflicting sequence number */
+ di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
+ btrfs_inode_ref_index(eb, ref),
+ name, namelen, 0);
+ if (di && !IS_ERR(di)) {
+ ret = drop_one_dir_item(trans, root, path, dir, di);
+ BUG_ON(ret);
+ }
+ btrfs_release_path(root, path);
+
+
+ /* look for a conflicting name */
+ di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
+ name, namelen, 0);
+ if (di && !IS_ERR(di)) {
+ ret = drop_one_dir_item(trans, root, path, dir, di);
+ BUG_ON(ret);
+ }
+ btrfs_release_path(root, path);
+
+ /* insert our name */
+ ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
+ btrfs_inode_ref_index(eb, ref));
+ BUG_ON(ret);
+
+ btrfs_update_inode(trans, root, inode);
+
+out:
+ ref_ptr = (unsigned long)(ref + 1) + namelen;
+ kfree(name);
+ if (ref_ptr < ref_end)
+ goto again;
+
+ /* finally write the back reference in the inode */
+ ret = overwrite_item(trans, root, path, eb, slot, key);
+ BUG_ON(ret);
+
+out_nowrite:
+ btrfs_release_path(root, path);
+ iput(dir);
+ iput(inode);
+ return 0;
+}
+
+/*
+ * replay one csum item from the log tree into the subvolume 'root'
+ * eb, slot and key all refer to the log tree
+ * path is for temp use by this function and should be released on return
+ *
+ * This copies the checksums out of the log tree and inserts them into
+ * the subvolume. Any existing checksums for this range in the file
+ * are overwritten, and new items are added where required.
+ *
+ * We keep this simple by reusing the btrfs_ordered_sum code from
+ * the data=ordered mode. This basically means making a copy
+ * of all the checksums in ram, which we have to do anyway for kmap
+ * rules.
+ *
+ * The copy is then sent down to btrfs_csum_file_blocks, which
+ * does all the hard work of finding existing items in the file
+ * or adding new ones.
+ */
+static noinline int replay_one_csum(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int ret;
+ u32 item_size = btrfs_item_size_nr(eb, slot);
+ u64 cur_offset;
+ unsigned long file_bytes;
+ struct btrfs_ordered_sum *sums;
+ struct btrfs_sector_sum *sector_sum;
+ struct inode *inode;
+ unsigned long ptr;
+
+ file_bytes = (item_size / BTRFS_CRC32_SIZE) * root->sectorsize;
+ inode = read_one_inode(root, key->objectid);
+ if (!inode) {
+ return -EIO;
+ }
+
+ sums = kzalloc(btrfs_ordered_sum_size(root, file_bytes), GFP_NOFS);
+ if (!sums) {
+ iput(inode);
+ return -ENOMEM;
+ }
+
+ INIT_LIST_HEAD(&sums->list);
+ sums->len = file_bytes;
+ sums->file_offset = key->offset;
+
+ /*
+ * copy all the sums into the ordered sum struct
+ */
+ sector_sum = sums->sums;
+ cur_offset = key->offset;
+ ptr = btrfs_item_ptr_offset(eb, slot);
+ while(item_size > 0) {
+ sector_sum->offset = cur_offset;
+ read_extent_buffer(eb, §or_sum->sum, ptr, BTRFS_CRC32_SIZE);
+ sector_sum++;
+ item_size -= BTRFS_CRC32_SIZE;
+ ptr += BTRFS_CRC32_SIZE;
+ cur_offset += root->sectorsize;
+ }
+
+ /* let btrfs_csum_file_blocks add them into the file */
+ ret = btrfs_csum_file_blocks(trans, root, inode, sums);
+ BUG_ON(ret);
+ kfree(sums);
+ iput(inode);
+
+ return 0;
+}
+/*
+ * There are a few corners where the link count of the file can't
+ * be properly maintained during replay. So, instead of adding
+ * lots of complexity to the log code, we just scan the backrefs
+ * for any file that has been through replay.
+ *
+ * The scan will update the link count on the inode to reflect the
+ * number of back refs found. If it goes down to zero, the iput
+ * will free the inode.
+ */
+static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct btrfs_key key;
+ u64 nlink = 0;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ int name_len;
+
+ key.objectid = inode->i_ino;
+ key.type = BTRFS_INODE_REF_KEY;
+ key.offset = (u64)-1;
+
+ path = btrfs_alloc_path();
+
+ while(1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ path->slots[0]);
+ if (key.objectid != inode->i_ino ||
+ key.type != BTRFS_INODE_REF_KEY)
+ break;
+ ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+ ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
+ path->slots[0]);
+ while(ptr < ptr_end) {
+ struct btrfs_inode_ref *ref;
+
+ ref = (struct btrfs_inode_ref *)ptr;
+ name_len = btrfs_inode_ref_name_len(path->nodes[0],
+ ref);
+ ptr = (unsigned long)(ref + 1) + name_len;
+ nlink++;
+ }
+
+ if (key.offset == 0)
+ break;
+ key.offset--;
+ btrfs_release_path(root, path);
+ }
+ btrfs_free_path(path);
+ if (nlink != inode->i_nlink) {
+ inode->i_nlink = nlink;
+ btrfs_update_inode(trans, root, inode);
+ }
+ BTRFS_I(inode)->index_cnt = (u64)-1;
+
+ return 0;
+}
+
+static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ int ret;
+ struct btrfs_key key;
+ struct inode *inode;
+
+ key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
+ key.type = BTRFS_ORPHAN_ITEM_KEY;
+ key.offset = (u64)-1;
+ while(1) {
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ break;
+
+ if (ret == 1) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
+ key.type != BTRFS_ORPHAN_ITEM_KEY)
+ break;
+
+ ret = btrfs_del_item(trans, root, path);
+ BUG_ON(ret);
+
+ btrfs_release_path(root, path);
+ inode = read_one_inode(root, key.offset);
+ BUG_ON(!inode);
+
+ ret = fixup_inode_link_count(trans, root, inode);
+ BUG_ON(ret);
+
+ iput(inode);
+
+ if (key.offset == 0)
+ break;
+ key.offset--;
+ }
+ btrfs_release_path(root, path);
+ return 0;
+}
+
+
+/*
+ * record a given inode in the fixup dir so we can check its link
+ * count when replay is done. The link count is incremented here
+ * so the inode won't go away until we check it
+ */
+static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid)
+{
+ struct btrfs_key key;
+ int ret = 0;
+ struct inode *inode;
+
+ inode = read_one_inode(root, objectid);
+ BUG_ON(!inode);
+
+ key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
+ btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
+ key.offset = objectid;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
+
+ btrfs_release_path(root, path);
+ if (ret == 0) {
+ btrfs_inc_nlink(inode);
+ btrfs_update_inode(trans, root, inode);
+ } else if (ret == -EEXIST) {
+ ret = 0;
+ } else {
+ BUG();
+ }
+ iput(inode);
+
+ return ret;
+}
+
+/*
+ * when replaying the log for a directory, we only insert names
+ * for inodes that actually exist. This means an fsync on a directory
+ * does not implicitly fsync all the new files in it
+ */
+static noinline int insert_one_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 dirid, u64 index,
+ char *name, int name_len, u8 type,
+ struct btrfs_key *location)
+{
+ struct inode *inode;
+ struct inode *dir;
+ int ret;
+
+ inode = read_one_inode(root, location->objectid);
+ if (!inode)
+ return -ENOENT;
+
+ dir = read_one_inode(root, dirid);
+ if (!dir) {
+ iput(inode);
+ return -EIO;
+ }
+ ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
+
+ /* FIXME, put inode into FIXUP list */
+
+ iput(inode);
+ iput(dir);
+ return ret;
+}
+
+/*
+ * take a single entry in a log directory item and replay it into
+ * the subvolume.
+ *
+ * if a conflicting item exists in the subdirectory already,
+ * the inode it points to is unlinked and put into the link count
+ * fix up tree.
+ *
+ * If a name from the log points to a file or directory that does
+ * not exist in the FS, it is skipped. fsyncs on directories
+ * do not force down inodes inside that directory, just changes to the
+ * names or unlinks in a directory.
+ */
+static noinline int replay_one_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb,
+ struct btrfs_dir_item *di,
+ struct btrfs_key *key)
+{
+ char *name;
+ int name_len;
+ struct btrfs_dir_item *dst_di;
+ struct btrfs_key found_key;
+ struct btrfs_key log_key;
+ struct inode *dir;
+ u8 log_type;
+ int exists;
+ int ret;
+
+ dir = read_one_inode(root, key->objectid);
+ BUG_ON(!dir);
+
+ name_len = btrfs_dir_name_len(eb, di);
+ name = kmalloc(name_len, GFP_NOFS);
+ log_type = btrfs_dir_type(eb, di);
+ read_extent_buffer(eb, name, (unsigned long)(di + 1),
+ name_len);
+
+ btrfs_dir_item_key_to_cpu(eb, di, &log_key);
+ exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
+ if (exists == 0)
+ exists = 1;
+ else
+ exists = 0;
+ btrfs_release_path(root, path);
+
+ if (key->type == BTRFS_DIR_ITEM_KEY) {
+ dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
+ name, name_len, 1);
+ }
+ else if (key->type == BTRFS_DIR_INDEX_KEY) {
+ dst_di = btrfs_lookup_dir_index_item(trans, root, path,
+ key->objectid,
+ key->offset, name,
+ name_len, 1);
+ } else {
+ BUG();
+ }
+ if (!dst_di || IS_ERR(dst_di)) {
+ /* we need a sequence number to insert, so we only
+ * do inserts for the BTRFS_DIR_INDEX_KEY types
+ */
+ if (key->type != BTRFS_DIR_INDEX_KEY)
+ goto out;
+ goto insert;
+ }
+
+ btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
+ /* the existing item matches the logged item */
+ if (found_key.objectid == log_key.objectid &&
+ found_key.type == log_key.type &&
+ found_key.offset == log_key.offset &&
+ btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
+ goto out;
+ }
+
+ /*
+ * don't drop the conflicting directory entry if the inode
+ * for the new entry doesn't exist
+ */
+ if (!exists)
+ goto out;
+
+ ret = drop_one_dir_item(trans, root, path, dir, dst_di);
+ BUG_ON(ret);
+
+ if (key->type == BTRFS_DIR_INDEX_KEY)
+ goto insert;
+out:
+ btrfs_release_path(root, path);
+ kfree(name);
+ iput(dir);
+ return 0;
+
+insert:
+ btrfs_release_path(root, path);
+ ret = insert_one_name(trans, root, path, key->objectid, key->offset,
+ name, name_len, log_type, &log_key);
+
+ if (ret && ret != -ENOENT)
+ BUG();
+ goto out;
+}
+
+/*
+ * find all the names in a directory item and reconcile them into
+ * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
+ * one name in a directory item, but the same code gets used for
+ * both directory index types
+ */
+static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int ret;
+ u32 item_size = btrfs_item_size_nr(eb, slot);
+ struct btrfs_dir_item *di;
+ int name_len;
+ unsigned long ptr;
+ unsigned long ptr_end;
+
+ ptr = btrfs_item_ptr_offset(eb, slot);
+ ptr_end = ptr + item_size;
+ while(ptr < ptr_end) {
+ di = (struct btrfs_dir_item *)ptr;
+ name_len = btrfs_dir_name_len(eb, di);
+ ret = replay_one_name(trans, root, path, eb, di, key);
+ BUG_ON(ret);
+ ptr = (unsigned long)(di + 1);
+ ptr += name_len;
+ }
+ return 0;
+}
+
+/*
+ * directory replay has two parts. There are the standard directory
+ * items in the log copied from the subvolume, and range items
+ * created in the log while the subvolume was logged.
+ *
+ * The range items tell us which parts of the key space the log
+ * is authoritative for. During replay, if a key in the subvolume
+ * directory is in a logged range item, but not actually in the log
+ * that means it was deleted from the directory before the fsync
+ * and should be removed.
+ */
+static noinline int find_dir_range(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 dirid, int key_type,
+ u64 *start_ret, u64 *end_ret)
+{
+ struct btrfs_key key;
+ u64 found_end;
+ struct btrfs_dir_log_item *item;
+ int ret;
+ int nritems;
+
+ if (*start_ret == (u64)-1)
+ return 1;
+
+ key.objectid = dirid;
+ key.type = key_type;
+ key.offset = *start_ret;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ goto out;
+ path->slots[0]--;
+ }
+ if (ret != 0)
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+
+ if (key.type != key_type || key.objectid != dirid) {
+ ret = 1;
+ goto next;
+ }
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ found_end = btrfs_dir_log_end(path->nodes[0], item);
+
+ if (*start_ret >= key.offset && *start_ret <= found_end) {
+ ret = 0;
+ *start_ret = key.offset;
+ *end_ret = found_end;
+ goto out;
+ }
+ ret = 1;
+next:
+ /* check the next slot in the tree to see if it is a valid item */
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ goto out;
+ } else {
+ path->slots[0]++;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+
+ if (key.type != key_type || key.objectid != dirid) {
+ ret = 1;
+ goto out;
+ }
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ found_end = btrfs_dir_log_end(path->nodes[0], item);
+ *start_ret = key.offset;
+ *end_ret = found_end;
+ ret = 0;
+out:
+ btrfs_release_path(root, path);
+ return ret;
+}
+
+/*
+ * this looks for a given directory item in the log. If the directory
+ * item is not in the log, the item is removed and the inode it points
+ * to is unlinked
+ */
+static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ struct btrfs_path *log_path,
+ struct inode *dir,
+ struct btrfs_key *dir_key)
+{
+ int ret;
+ struct extent_buffer *eb;
+ int slot;
+ u32 item_size;
+ struct btrfs_dir_item *di;
+ struct btrfs_dir_item *log_di;
+ int name_len;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ char *name;
+ struct inode *inode;
+ struct btrfs_key location;
+
+again:
+ eb = path->nodes[0];
+ slot = path->slots[0];
+ item_size = btrfs_item_size_nr(eb, slot);
+ ptr = btrfs_item_ptr_offset(eb, slot);
+ ptr_end = ptr + item_size;
+ while(ptr < ptr_end) {
+ di = (struct btrfs_dir_item *)ptr;
+ name_len = btrfs_dir_name_len(eb, di);
+ name = kmalloc(name_len, GFP_NOFS);
+ if (!name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ read_extent_buffer(eb, name, (unsigned long)(di + 1),
+ name_len);
+ log_di = NULL;
+ if (dir_key->type == BTRFS_DIR_ITEM_KEY) {
+ log_di = btrfs_lookup_dir_item(trans, log, log_path,
+ dir_key->objectid,
+ name, name_len, 0);
+ } else if (dir_key->type == BTRFS_DIR_INDEX_KEY) {
+ log_di = btrfs_lookup_dir_index_item(trans, log,
+ log_path,
+ dir_key->objectid,
+ dir_key->offset,
+ name, name_len, 0);
+ }
+ if (!log_di || IS_ERR(log_di)) {
+ btrfs_dir_item_key_to_cpu(eb, di, &location);
+ btrfs_release_path(root, path);
+ btrfs_release_path(log, log_path);
+ inode = read_one_inode(root, location.objectid);
+ BUG_ON(!inode);
+
+ ret = link_to_fixup_dir(trans, root,
+ path, location.objectid);
+ BUG_ON(ret);
+ btrfs_inc_nlink(inode);
+ ret = btrfs_unlink_inode(trans, root, dir, inode,
+ name, name_len);
+ BUG_ON(ret);
+ kfree(name);
+ iput(inode);
+
+ /* there might still be more names under this key
+ * check and repeat if required
+ */
+ ret = btrfs_search_slot(NULL, root, dir_key, path,
+ 0, 0);
+ if (ret == 0)
+ goto again;
+ ret = 0;
+ goto out;
+ }
+ btrfs_release_path(log, log_path);
+ kfree(name);
+
+ ptr = (unsigned long)(di + 1);
+ ptr += name_len;
+ }
+ ret = 0;
+out:
+ btrfs_release_path(root, path);
+ btrfs_release_path(log, log_path);
+ return ret;
+}
+
+/*
+ * deletion replay happens before we copy any new directory items
+ * out of the log or out of backreferences from inodes. It
+ * scans the log to find ranges of keys that log is authoritative for,
+ * and then scans the directory to find items in those ranges that are
+ * not present in the log.
+ *
+ * Anything we don't find in the log is unlinked and removed from the
+ * directory.
+ */
+static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dirid)
+{
+ u64 range_start;
+ u64 range_end;
+ int key_type = BTRFS_DIR_LOG_ITEM_KEY;
+ int ret = 0;
+ struct btrfs_key dir_key;
+ struct btrfs_key found_key;
+ struct btrfs_path *log_path;
+ struct inode *dir;
+
+ dir_key.objectid = dirid;
+ dir_key.type = BTRFS_DIR_ITEM_KEY;
+ log_path = btrfs_alloc_path();
+ if (!log_path)
+ return -ENOMEM;
+
+ dir = read_one_inode(root, dirid);
+ /* it isn't an error if the inode isn't there, that can happen
+ * because we replay the deletes before we copy in the inode item
+ * from the log
+ */
+ if (!dir) {
+ btrfs_free_path(log_path);
+ return 0;
+ }
+again:
+ range_start = 0;
+ range_end = 0;
+ while(1) {
+ ret = find_dir_range(log, path, dirid, key_type,
+ &range_start, &range_end);
+ if (ret != 0)
+ break;
+
+ dir_key.offset = range_start;
+ while(1) {
+ int nritems;
+ ret = btrfs_search_slot(NULL, root, &dir_key, path,
+ 0, 0);
+ if (ret < 0)
+ goto out;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ break;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ if (found_key.objectid != dirid ||
+ found_key.type != dir_key.type)
+ goto next_type;
+
+ if (found_key.offset > range_end)
+ break;
+
+ ret = check_item_in_log(trans, root, log, path,
+ log_path, dir, &found_key);
+ BUG_ON(ret);
+ if (found_key.offset == (u64)-1)
+ break;
+ dir_key.offset = found_key.offset + 1;
+ }
+ btrfs_release_path(root, path);
+ if (range_end == (u64)-1)
+ break;
+ range_start = range_end + 1;
+ }
+
+next_type:
+ ret = 0;
+ if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
+ key_type = BTRFS_DIR_LOG_INDEX_KEY;
+ dir_key.type = BTRFS_DIR_INDEX_KEY;
+ btrfs_release_path(root, path);
+ goto again;
+ }
+out:
+ btrfs_release_path(root, path);
+ btrfs_free_path(log_path);
+ iput(dir);
+ return ret;
+}
+
+/*
+ * the process_func used to replay items from the log tree. This
+ * gets called in two different stages. The first stage just looks
+ * for inodes and makes sure they are all copied into the subvolume.
+ *
+ * The second stage copies all the other item types from the log into
+ * the subvolume. The two stage approach is slower, but gets rid of
+ * lots of complexity around inodes referencing other inodes that exist
+ * only in the log (references come from either directory items or inode
+ * back refs).
+ */
+static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen)
+{
+ int nritems;
+ struct btrfs_path *path;
+ struct btrfs_root *root = wc->replay_dest;
+ struct btrfs_key key;
+ u32 item_size;
+ int level;
+ int i;
+ int ret;
+
+ btrfs_read_buffer(eb, gen);
+
+ level = btrfs_header_level(eb);
+
+ if (level != 0)
+ return 0;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ nritems = btrfs_header_nritems(eb);
+ for (i = 0; i < nritems; i++) {
+ btrfs_item_key_to_cpu(eb, &key, i);
+ item_size = btrfs_item_size_nr(eb, i);
+
+ /* inode keys are done during the first stage */
+ if (key.type == BTRFS_INODE_ITEM_KEY &&
+ wc->stage == LOG_WALK_REPLAY_INODES) {
+ struct inode *inode;
+ struct btrfs_inode_item *inode_item;
+ u32 mode;
+
+ inode_item = btrfs_item_ptr(eb, i,
+ struct btrfs_inode_item);
+ mode = btrfs_inode_mode(eb, inode_item);
+ if (S_ISDIR(mode)) {
+ ret = replay_dir_deletes(wc->trans,
+ root, log, path, key.objectid);
+ BUG_ON(ret);
+ }
+ ret = overwrite_item(wc->trans, root, path,
+ eb, i, &key);
+ BUG_ON(ret);
+
+ /* for regular files, truncate away
+ * extents past the new EOF
+ */
+ if (S_ISREG(mode)) {
+ inode = read_one_inode(root,
+ key.objectid);
+ BUG_ON(!inode);
+
+ ret = btrfs_truncate_inode_items(wc->trans,
+ root, inode, inode->i_size,
+ BTRFS_EXTENT_DATA_KEY);
+ BUG_ON(ret);
+ iput(inode);
+ }
+ ret = link_to_fixup_dir(wc->trans, root,
+ path, key.objectid);
+ BUG_ON(ret);
+ }
+ if (wc->stage < LOG_WALK_REPLAY_ALL)
+ continue;
+
+ /* these keys are simply copied */
+ if (key.type == BTRFS_XATTR_ITEM_KEY) {
+ ret = overwrite_item(wc->trans, root, path,
+ eb, i, &key);
+ BUG_ON(ret);
+ } else if (key.type == BTRFS_INODE_REF_KEY) {
+ ret = add_inode_ref(wc->trans, root, log, path,
+ eb, i, &key);
+ BUG_ON(ret && ret != -ENOENT);
+ } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
+ ret = replay_one_extent(wc->trans, root, path,
+ eb, i, &key);
+ BUG_ON(ret);
+ } else if (key.type == BTRFS_CSUM_ITEM_KEY) {
+ ret = replay_one_csum(wc->trans, root, path,
+ eb, i, &key);
+ BUG_ON(ret);
+ } else if (key.type == BTRFS_DIR_ITEM_KEY ||
+ key.type == BTRFS_DIR_INDEX_KEY) {
+ ret = replay_one_dir_item(wc->trans, root, path,
+ eb, i, &key);
+ BUG_ON(ret);
+ }
+ }
+ btrfs_free_path(path);
+ return 0;
+}
+
+static int noinline walk_down_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level,
+ struct walk_control *wc)
+{
+ u64 root_owner;
+ u64 root_gen;
+ u64 bytenr;
+ u64 ptr_gen;
+ struct extent_buffer *next;
+ struct extent_buffer *cur;
+ struct extent_buffer *parent;
+ u32 blocksize;
+ int ret = 0;
+
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+
+ while(*level > 0) {
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+ cur = path->nodes[*level];
+
+ if (btrfs_header_level(cur) != *level)
+ WARN_ON(1);
+
+ if (path->slots[*level] >=
+ btrfs_header_nritems(cur))
+ break;
+
+ bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
+ ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
+ blocksize = btrfs_level_size(root, *level - 1);
+
+ parent = path->nodes[*level];
+ root_owner = btrfs_header_owner(parent);
+ root_gen = btrfs_header_generation(parent);
+
+ next = btrfs_find_create_tree_block(root, bytenr, blocksize);
+
+ wc->process_func(root, next, wc, ptr_gen);
+
+ if (*level == 1) {
+ path->slots[*level]++;
+ if (wc->free) {
+ btrfs_read_buffer(next, ptr_gen);
+
+ btrfs_tree_lock(next);
+ clean_tree_block(trans, root, next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+
+ ret = btrfs_drop_leaf_ref(trans, root, next);
+ BUG_ON(ret);
+
+ WARN_ON(root_owner !=
+ BTRFS_TREE_LOG_OBJECTID);
+ ret = btrfs_free_reserved_extent(root,
+ bytenr, blocksize);
+ BUG_ON(ret);
+ }
+ free_extent_buffer(next);
+ continue;
+ }
+ btrfs_read_buffer(next, ptr_gen);
+
+ WARN_ON(*level <= 0);
+ if (path->nodes[*level-1])
+ free_extent_buffer(path->nodes[*level-1]);
+ path->nodes[*level-1] = next;
+ *level = btrfs_header_level(next);
+ path->slots[*level] = 0;
+ cond_resched();
+ }
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+
+ if (path->nodes[*level] == root->node) {
+ parent = path->nodes[*level];
+ } else {
+ parent = path->nodes[*level + 1];
+ }
+ bytenr = path->nodes[*level]->start;
+
+ blocksize = btrfs_level_size(root, *level);
+ root_owner = btrfs_header_owner(parent);
+ root_gen = btrfs_header_generation(parent);
+
+ wc->process_func(root, path->nodes[*level], wc,
+ btrfs_header_generation(path->nodes[*level]));
+
+ if (wc->free) {
+ next = path->nodes[*level];
+ btrfs_tree_lock(next);
+ clean_tree_block(trans, root, next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+
+ if (*level == 0) {
+ ret = btrfs_drop_leaf_ref(trans, root, next);
+ BUG_ON(ret);
+ }
+ WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
+ ret = btrfs_free_reserved_extent(root, bytenr, blocksize);
+ BUG_ON(ret);
+ }
+ free_extent_buffer(path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level += 1;
+
+ cond_resched();
+ return 0;
+}
+
+static int noinline walk_up_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level,
+ struct walk_control *wc)
+{
+ u64 root_owner;
+ u64 root_gen;
+ int i;
+ int slot;
+ int ret;
+
+ for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
+ slot = path->slots[i];
+ if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
+ struct extent_buffer *node;
+ node = path->nodes[i];
+ path->slots[i]++;
+ *level = i;
+ WARN_ON(*level == 0);
+ return 0;
+ } else {
+ struct extent_buffer *parent;
+ if (path->nodes[*level] == root->node)
+ parent = path->nodes[*level];
+ else
+ parent = path->nodes[*level + 1];
+
+ root_owner = btrfs_header_owner(parent);
+ root_gen = btrfs_header_generation(parent);
+ wc->process_func(root, path->nodes[*level], wc,
+ btrfs_header_generation(path->nodes[*level]));
+ if (wc->free) {
+ struct extent_buffer *next;
+
+ next = path->nodes[*level];
+
+ btrfs_tree_lock(next);
+ clean_tree_block(trans, root, next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+
+ if (*level == 0) {
+ ret = btrfs_drop_leaf_ref(trans, root,
+ next);
+ BUG_ON(ret);
+ }
+
+ WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
+ ret = btrfs_free_reserved_extent(root,
+ path->nodes[*level]->start,
+ path->nodes[*level]->len);
+ BUG_ON(ret);
+ }
+ free_extent_buffer(path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level = i + 1;
+ }
+ }
+ return 1;
+}
+
+/*
+ * drop the reference count on the tree rooted at 'snap'. This traverses
+ * the tree freeing any blocks that have a ref count of zero after being
+ * decremented.
+ */
+static int walk_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log, struct walk_control *wc)
+{
+ int ret = 0;
+ int wret;
+ int level;
+ struct btrfs_path *path;
+ int i;
+ int orig_level;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ level = btrfs_header_level(log->node);
+ orig_level = level;
+ path->nodes[level] = log->node;
+ extent_buffer_get(log->node);
+ path->slots[level] = 0;
+
+ while(1) {
+ wret = walk_down_log_tree(trans, log, path, &level, wc);
+ if (wret > 0)
+ break;
+ if (wret < 0)
+ ret = wret;
+
+ wret = walk_up_log_tree(trans, log, path, &level, wc);
+ if (wret > 0)
+ break;
+ if (wret < 0)
+ ret = wret;
+ }
+
+ /* was the root node processed? if not, catch it here */
+ if (path->nodes[orig_level]) {
+ wc->process_func(log, path->nodes[orig_level], wc,
+ btrfs_header_generation(path->nodes[orig_level]));
+ if (wc->free) {
+ struct extent_buffer *next;
+
+ next = path->nodes[orig_level];
+
+ btrfs_tree_lock(next);
+ clean_tree_block(trans, log, next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+
+ if (orig_level == 0) {
+ ret = btrfs_drop_leaf_ref(trans, log,
+ next);
+ BUG_ON(ret);
+ }
+ WARN_ON(log->root_key.objectid !=
+ BTRFS_TREE_LOG_OBJECTID);
+ ret = btrfs_free_reserved_extent(log, next->start,
+ next->len);
+ BUG_ON(ret);
+ }
+ }
+
+ for (i = 0; i <= orig_level; i++) {
+ if (path->nodes[i]) {
+ free_extent_buffer(path->nodes[i]);
+ path->nodes[i] = NULL;
+ }
+ }
+ btrfs_free_path(path);
+ if (wc->free)
+ free_extent_buffer(log->node);
+ return ret;
+}
+
+int wait_log_commit(struct btrfs_root *log)
+{
+ DEFINE_WAIT(wait);
+ u64 transid = log->fs_info->tree_log_transid;
+
+ do {
+ prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ mutex_unlock(&log->fs_info->tree_log_mutex);
+ if (atomic_read(&log->fs_info->tree_log_commit))
+ schedule();
+ finish_wait(&log->fs_info->tree_log_wait, &wait);
+ mutex_lock(&log->fs_info->tree_log_mutex);
+ } while(transid == log->fs_info->tree_log_transid &&
+ atomic_read(&log->fs_info->tree_log_commit));
+ return 0;
+}
+
+/*
+ * btrfs_sync_log does sends a given tree log down to the disk and
+ * updates the super blocks to record it. When this call is done,
+ * you know that any inodes previously logged are safely on disk
+ */
+int btrfs_sync_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ int ret;
+ unsigned long batch;
+ struct btrfs_root *log = root->log_root;
+
+ mutex_lock(&log->fs_info->tree_log_mutex);
+ if (atomic_read(&log->fs_info->tree_log_commit)) {
+ wait_log_commit(log);
+ goto out;
+ }
+ atomic_set(&log->fs_info->tree_log_commit, 1);
+
+ while(1) {
+ batch = log->fs_info->tree_log_batch;
+ mutex_unlock(&log->fs_info->tree_log_mutex);
+ schedule_timeout_uninterruptible(1);
+ mutex_lock(&log->fs_info->tree_log_mutex);
+
+ while(atomic_read(&log->fs_info->tree_log_writers)) {
+ DEFINE_WAIT(wait);
+ prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ mutex_unlock(&log->fs_info->tree_log_mutex);
+ if (atomic_read(&log->fs_info->tree_log_writers))
+ schedule();
+ mutex_lock(&log->fs_info->tree_log_mutex);
+ finish_wait(&log->fs_info->tree_log_wait, &wait);
+ }
+ if (batch == log->fs_info->tree_log_batch)
+ break;
+ }
+
+ ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages);
+ BUG_ON(ret);
+ ret = btrfs_write_and_wait_marked_extents(root->fs_info->log_root_tree,
+ &root->fs_info->log_root_tree->dirty_log_pages);
+ BUG_ON(ret);
+
+ btrfs_set_super_log_root(&root->fs_info->super_for_commit,
+ log->fs_info->log_root_tree->node->start);
+ btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
+ btrfs_header_level(log->fs_info->log_root_tree->node));
+
+ write_ctree_super(trans, log->fs_info->tree_root);
+ log->fs_info->tree_log_transid++;
+ log->fs_info->tree_log_batch = 0;
+ atomic_set(&log->fs_info->tree_log_commit, 0);
+ smp_mb();
+ if (waitqueue_active(&log->fs_info->tree_log_wait))
+ wake_up(&log->fs_info->tree_log_wait);
+out:
+ mutex_unlock(&log->fs_info->tree_log_mutex);
+ return 0;
+
+}
+
+/* * free all the extents used by the tree log. This should be called
+ * at commit time of the full transaction
+ */
+int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
+{
+ int ret;
+ struct btrfs_root *log;
+ struct key;
+ u64 start;
+ u64 end;
+ struct walk_control wc = {
+ .free = 1,
+ .process_func = process_one_buffer
+ };
+
+ if (!root->log_root)
+ return 0;
+
+ log = root->log_root;
+ ret = walk_log_tree(trans, log, &wc);
+ BUG_ON(ret);
+
+ while(1) {
+ ret = find_first_extent_bit(&log->dirty_log_pages,
+ 0, &start, &end, EXTENT_DIRTY);
+ if (ret)
+ break;
+
+ clear_extent_dirty(&log->dirty_log_pages,
+ start, end, GFP_NOFS);
+ }
+
+ log = root->log_root;
+ ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
+ &log->root_key);
+ BUG_ON(ret);
+ root->log_root = NULL;
+ kfree(root->log_root);
+ return 0;
+}
+
+/*
+ * helper function to update the item for a given subvolumes log root
+ * in the tree of log roots
+ */
+static int update_log_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log)
+{
+ u64 bytenr = btrfs_root_bytenr(&log->root_item);
+ int ret;
+
+ if (log->node->start == bytenr)
+ return 0;
+
+ btrfs_set_root_bytenr(&log->root_item, log->node->start);
+ btrfs_set_root_generation(&log->root_item, trans->transid);
+ btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node));
+ ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
+ &log->root_key, &log->root_item);
+ BUG_ON(ret);
+ return ret;
+}
+
+/*
+ * If both a file and directory are logged, and unlinks or renames are
+ * mixed in, we have a few interesting corners:
+ *
+ * create file X in dir Y
+ * link file X to X.link in dir Y
+ * fsync file X
+ * unlink file X but leave X.link
+ * fsync dir Y
+ *
+ * After a crash we would expect only X.link to exist. But file X
+ * didn't get fsync'd again so the log has back refs for X and X.link.
+ *
+ * We solve this by removing directory entries and inode backrefs from the
+ * log when a file that was logged in the current transaction is
+ * unlinked. Any later fsync will include the updated log entries, and
+ * we'll be able to reconstruct the proper directory items from backrefs.
+ *
+ * This optimizations allows us to avoid relogging the entire inode
+ * or the entire directory.
+ */
+int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ struct inode *dir, u64 index)
+{
+ struct btrfs_root *log;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ int ret;
+ int bytes_del = 0;
+
+ if (BTRFS_I(dir)->logged_trans < trans->transid)
+ return 0;
+
+ ret = join_running_log_trans(root);
+ if (ret)
+ return 0;
+
+ mutex_lock(&BTRFS_I(dir)->log_mutex);
+
+ log = root->log_root;
+ path = btrfs_alloc_path();
+ di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
+ name, name_len, -1);
+ if (di && !IS_ERR(di)) {
+ ret = btrfs_delete_one_dir_name(trans, log, path, di);
+ bytes_del += name_len;
+ BUG_ON(ret);
+ }
+ btrfs_release_path(log, path);
+ di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino,
+ index, name, name_len, -1);
+ if (di && !IS_ERR(di)) {
+ ret = btrfs_delete_one_dir_name(trans, log, path, di);
+ bytes_del += name_len;
+ BUG_ON(ret);
+ }
+
+ /* update the directory size in the log to reflect the names
+ * we have removed
+ */
+ if (bytes_del) {
+ struct btrfs_key key;
+
+ key.objectid = dir->i_ino;
+ key.offset = 0;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ btrfs_release_path(log, path);
+
+ ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
+ if (ret == 0) {
+ struct btrfs_inode_item *item;
+ u64 i_size;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ i_size = btrfs_inode_size(path->nodes[0], item);
+ if (i_size > bytes_del)
+ i_size -= bytes_del;
+ else
+ i_size = 0;
+ btrfs_set_inode_size(path->nodes[0], item, i_size);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ } else
+ ret = 0;
+ btrfs_release_path(log, path);
+ }
+
+ btrfs_free_path(path);
+ mutex_unlock(&BTRFS_I(dir)->log_mutex);
+ end_log_trans(root);
+
+ return 0;
+}
+
+/* see comments for btrfs_del_dir_entries_in_log */
+int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ struct inode *inode, u64 dirid)
+{
+ struct btrfs_root *log;
+ u64 index;
+ int ret;
+
+ if (BTRFS_I(inode)->logged_trans < trans->transid)
+ return 0;
+
+ ret = join_running_log_trans(root);
+ if (ret)
+ return 0;
+ log = root->log_root;
+ mutex_lock(&BTRFS_I(inode)->log_mutex);
+
+ ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
+ dirid, &index);
+ mutex_unlock(&BTRFS_I(inode)->log_mutex);
+ end_log_trans(root);
+
+ return ret;
+}
+
+/*
+ * creates a range item in the log for 'dirid'. first_offset and
+ * last_offset tell us which parts of the key space the log should
+ * be considered authoritative for.
+ */
+static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ int key_type, u64 dirid,
+ u64 first_offset, u64 last_offset)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_dir_log_item *item;
+
+ key.objectid = dirid;
+ key.offset = first_offset;
+ if (key_type == BTRFS_DIR_ITEM_KEY)
+ key.type = BTRFS_DIR_LOG_ITEM_KEY;
+ else
+ key.type = BTRFS_DIR_LOG_INDEX_KEY;
+ ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
+ BUG_ON(ret);
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(log, path);
+ return 0;
+}
+
+/*
+ * log all the items included in the current transaction for a given
+ * directory. This also creates the range items in the log tree required
+ * to replay anything deleted before the fsync
+ */
+static noinline int log_dir_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path, int key_type,
+ u64 min_offset, u64 *last_offset_ret)
+{
+ struct btrfs_key min_key;
+ struct btrfs_key max_key;
+ struct btrfs_root *log = root->log_root;
+ struct extent_buffer *src;
+ int ret;
+ int i;
+ int nritems;
+ u64 first_offset = min_offset;
+ u64 last_offset = (u64)-1;
+
+ log = root->log_root;
+ max_key.objectid = inode->i_ino;
+ max_key.offset = (u64)-1;
+ max_key.type = key_type;
+
+ min_key.objectid = inode->i_ino;
+ min_key.type = key_type;
+ min_key.offset = min_offset;
+
+ path->keep_locks = 1;
+
+ ret = btrfs_search_forward(root, &min_key, &max_key,
+ path, 0, trans->transid);
+
+ /*
+ * we didn't find anything from this transaction, see if there
+ * is anything at all
+ */
+ if (ret != 0 || min_key.objectid != inode->i_ino ||
+ min_key.type != key_type) {
+ min_key.objectid = inode->i_ino;
+ min_key.type = key_type;
+ min_key.offset = (u64)-1;
+ btrfs_release_path(root, path);
+ ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
+ if (ret < 0) {
+ btrfs_release_path(root, path);
+ return ret;
+ }
+ ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
+
+ /* if ret == 0 there are items for this type,
+ * create a range to tell us the last key of this type.
+ * otherwise, there are no items in this directory after
+ * *min_offset, and we create a range to indicate that.
+ */
+ if (ret == 0) {
+ struct btrfs_key tmp;
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp,
+ path->slots[0]);
+ if (key_type == tmp.type) {
+ first_offset = max(min_offset, tmp.offset) + 1;
+ }
+ }
+ goto done;
+ }
+
+ /* go backward to find any previous key */
+ ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
+ if (ret == 0) {
+ struct btrfs_key tmp;
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
+ if (key_type == tmp.type) {
+ first_offset = tmp.offset;
+ ret = overwrite_item(trans, log, dst_path,
+ path->nodes[0], path->slots[0],
+ &tmp);
+ }
+ }
+ btrfs_release_path(root, path);
+
+ /* find the first key from this transaction again */
+ ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
+ if (ret != 0) {
+ WARN_ON(1);
+ goto done;
+ }
+
+ /*
+ * we have a block from this transaction, log every item in it
+ * from our directory
+ */
+ while(1) {
+ struct btrfs_key tmp;
+ src = path->nodes[0];
+ nritems = btrfs_header_nritems(src);
+ for (i = path->slots[0]; i < nritems; i++) {
+ btrfs_item_key_to_cpu(src, &min_key, i);
+
+ if (min_key.objectid != inode->i_ino ||
+ min_key.type != key_type)
+ goto done;
+ ret = overwrite_item(trans, log, dst_path, src, i,
+ &min_key);
+ BUG_ON(ret);
+ }
+ path->slots[0] = nritems;
+
+ /*
+ * look ahead to the next item and see if it is also
+ * from this directory and from this transaction
+ */
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 1) {
+ last_offset = (u64)-1;
+ goto done;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
+ if (tmp.objectid != inode->i_ino || tmp.type != key_type) {
+ last_offset = (u64)-1;
+ goto done;
+ }
+ if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
+ ret = overwrite_item(trans, log, dst_path,
+ path->nodes[0], path->slots[0],
+ &tmp);
+
+ BUG_ON(ret);
+ last_offset = tmp.offset;
+ goto done;
+ }
+ }
+done:
+ *last_offset_ret = last_offset;
+ btrfs_release_path(root, path);
+ btrfs_release_path(log, dst_path);
+
+ /* insert the log range keys to indicate where the log is valid */
+ ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino,
+ first_offset, last_offset);
+ BUG_ON(ret);
+ return 0;
+}
+
+/*
+ * logging directories is very similar to logging inodes, We find all the items
+ * from the current transaction and write them to the log.
+ *
+ * The recovery code scans the directory in the subvolume, and if it finds a
+ * key in the range logged that is not present in the log tree, then it means
+ * that dir entry was unlinked during the transaction.
+ *
+ * In order for that scan to work, we must include one key smaller than
+ * the smallest logged by this transaction and one key larger than the largest
+ * key logged by this transaction.
+ */
+static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path)
+{
+ u64 min_key;
+ u64 max_key;
+ int ret;
+ int key_type = BTRFS_DIR_ITEM_KEY;
+
+again:
+ min_key = 0;
+ max_key = 0;
+ while(1) {
+ ret = log_dir_items(trans, root, inode, path,
+ dst_path, key_type, min_key,
+ &max_key);
+ BUG_ON(ret);
+ if (max_key == (u64)-1)
+ break;
+ min_key = max_key + 1;
+ }
+
+ if (key_type == BTRFS_DIR_ITEM_KEY) {
+ key_type = BTRFS_DIR_INDEX_KEY;
+ goto again;
+ }
+ return 0;
+}
+
+/*
+ * a helper function to drop items from the log before we relog an
+ * inode. max_key_type indicates the highest item type to remove.
+ * This cannot be run for file data extents because it does not
+ * free the extents they point to.
+ */
+static int drop_objectid_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 objectid, int max_key_type)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+
+ key.objectid = objectid;
+ key.type = max_key_type;
+ key.offset = (u64)-1;
+
+ while(1) {
+ ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
+
+ if (ret != 1)
+ break;
+
+ if (path->slots[0] == 0)
+ break;
+
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+
+ if (found_key.objectid != objectid)
+ break;
+
+ ret = btrfs_del_item(trans, log, path);
+ BUG_ON(ret);
+ btrfs_release_path(log, path);
+ }
+ btrfs_release_path(log, path);
+ return 0;
+}
+
+static noinline int copy_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *dst_path,
+ struct extent_buffer *src,
+ int start_slot, int nr, int inode_only)
+{
+ unsigned long src_offset;
+ unsigned long dst_offset;
+ struct btrfs_file_extent_item *extent;
+ struct btrfs_inode_item *inode_item;
+ int ret;
+ struct btrfs_key *ins_keys;
+ u32 *ins_sizes;
+ char *ins_data;
+ int i;
+
+ ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
+ nr * sizeof(u32), GFP_NOFS);
+ ins_sizes = (u32 *)ins_data;
+ ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
+
+ for (i = 0; i < nr; i++) {
+ ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
+ btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
+ }
+ ret = btrfs_insert_empty_items(trans, log, dst_path,
+ ins_keys, ins_sizes, nr);
+ BUG_ON(ret);
+
+ for (i = 0; i < nr; i++) {
+ dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
+ dst_path->slots[0]);
+
+ src_offset = btrfs_item_ptr_offset(src, start_slot + i);
+
+ copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
+ src_offset, ins_sizes[i]);
+
+ if (inode_only == LOG_INODE_EXISTS &&
+ ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
+ inode_item = btrfs_item_ptr(dst_path->nodes[0],
+ dst_path->slots[0],
+ struct btrfs_inode_item);
+ btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
+
+ /* set the generation to zero so the recover code
+ * can tell the difference between an logging
+ * just to say 'this inode exists' and a logging
+ * to say 'update this inode with these values'
+ */
+ btrfs_set_inode_generation(dst_path->nodes[0],
+ inode_item, 0);
+ }
+ /* take a reference on file data extents so that truncates
+ * or deletes of this inode don't have to relog the inode
+ * again
+ */
+ if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY) {
+ int found_type;
+ extent = btrfs_item_ptr(src, start_slot + i,
+ struct btrfs_file_extent_item);
+
+ found_type = btrfs_file_extent_type(src, extent);
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ u64 ds = btrfs_file_extent_disk_bytenr(src,
+ extent);
+ u64 dl = btrfs_file_extent_disk_num_bytes(src,
+ extent);
+ /* ds == 0 is a hole */
+ if (ds != 0) {
+ ret = btrfs_inc_extent_ref(trans, log,
+ ds, dl,
+ dst_path->nodes[0]->start,
+ BTRFS_TREE_LOG_OBJECTID,
+ trans->transid,
+ ins_keys[i].objectid);
+ BUG_ON(ret);
+ }
+ }
+ }
+ dst_path->slots[0]++;
+ }
+
+ btrfs_mark_buffer_dirty(dst_path->nodes[0]);
+ btrfs_release_path(log, dst_path);
+ kfree(ins_data);
+ return 0;
+}
+
+/* log a single inode in the tree log.
+ * At least one parent directory for this inode must exist in the tree
+ * or be logged already.
+ *
+ * Any items from this inode changed by the current transaction are copied
+ * to the log tree. An extra reference is taken on any extents in this
+ * file, allowing us to avoid a whole pile of corner cases around logging
+ * blocks that have been removed from the tree.
+ *
+ * See LOG_INODE_ALL and related defines for a description of what inode_only
+ * does.
+ *
+ * This handles both files and directories.
+ */
+static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ int inode_only)
+{
+ struct btrfs_path *path;
+ struct btrfs_path *dst_path;
+ struct btrfs_key min_key;
+ struct btrfs_key max_key;
+ struct btrfs_root *log = root->log_root;
+ struct extent_buffer *src = NULL;
+ u32 size;
+ int ret;
+ int nritems;
+ int ins_start_slot = 0;
+ int ins_nr;
+
+ log = root->log_root;
+
+ path = btrfs_alloc_path();
+ dst_path = btrfs_alloc_path();
+
+ min_key.objectid = inode->i_ino;
+ min_key.type = BTRFS_INODE_ITEM_KEY;
+ min_key.offset = 0;
+
+ max_key.objectid = inode->i_ino;
+ if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
+ max_key.type = BTRFS_XATTR_ITEM_KEY;
+ else
+ max_key.type = (u8)-1;
+ max_key.offset = (u64)-1;
+
+ /*
+ * if this inode has already been logged and we're in inode_only
+ * mode, we don't want to delete the things that have already
+ * been written to the log.
+ *
+ * But, if the inode has been through an inode_only log,
+ * the logged_trans field is not set. This allows us to catch
+ * any new names for this inode in the backrefs by logging it
+ * again
+ */
+ if (inode_only == LOG_INODE_EXISTS &&
+ BTRFS_I(inode)->logged_trans == trans->transid) {
+ btrfs_free_path(path);
+ btrfs_free_path(dst_path);
+ goto out;
+ }
+ mutex_lock(&BTRFS_I(inode)->log_mutex);
+
+ /*
+ * a brute force approach to making sure we get the most uptodate
+ * copies of everything.
+ */
+ if (S_ISDIR(inode->i_mode)) {
+ int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
+
+ if (inode_only == LOG_INODE_EXISTS)
+ max_key_type = BTRFS_XATTR_ITEM_KEY;
+ ret = drop_objectid_items(trans, log, path,
+ inode->i_ino, max_key_type);
+ } else {
+ ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
+ }
+ BUG_ON(ret);
+ path->keep_locks = 1;
+
+ while(1) {
+ ins_nr = 0;
+ ret = btrfs_search_forward(root, &min_key, &max_key,
+ path, 0, trans->transid);
+ if (ret != 0)
+ break;
+again:
+ /* note, ins_nr might be > 0 here, cleanup outside the loop */
+ if (min_key.objectid != inode->i_ino)
+ break;
+ if (min_key.type > max_key.type)
+ break;
+
+ src = path->nodes[0];
+ size = btrfs_item_size_nr(src, path->slots[0]);
+ if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
+ ins_nr++;
+ goto next_slot;
+ } else if (!ins_nr) {
+ ins_start_slot = path->slots[0];
+ ins_nr = 1;
+ goto next_slot;
+ }
+
+ ret = copy_items(trans, log, dst_path, src, ins_start_slot,
+ ins_nr, inode_only);
+ BUG_ON(ret);
+ ins_nr = 1;
+ ins_start_slot = path->slots[0];
+next_slot:
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ path->slots[0]++;
+ if (path->slots[0] < nritems) {
+ btrfs_item_key_to_cpu(path->nodes[0], &min_key,
+ path->slots[0]);
+ goto again;
+ }
+ if (ins_nr) {
+ ret = copy_items(trans, log, dst_path, src,
+ ins_start_slot,
+ ins_nr, inode_only);
+ BUG_ON(ret);
+ ins_nr = 0;
+ }
+ btrfs_release_path(root, path);
+
+ if (min_key.offset < (u64)-1)
+ min_key.offset++;
+ else if (min_key.type < (u8)-1)
+ min_key.type++;
+ else if (min_key.objectid < (u64)-1)
+ min_key.objectid++;
+ else
+ break;
+ }
+ if (ins_nr) {
+ ret = copy_items(trans, log, dst_path, src,
+ ins_start_slot,
+ ins_nr, inode_only);
+ BUG_ON(ret);
+ ins_nr = 0;
+ }
+ WARN_ON(ins_nr);
+ if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
+ btrfs_release_path(root, path);
+ btrfs_release_path(log, dst_path);
+ BTRFS_I(inode)->log_dirty_trans = 0;
+ ret = log_directory_changes(trans, root, inode, path, dst_path);
+ BUG_ON(ret);
+ }
+ BTRFS_I(inode)->logged_trans = trans->transid;
+ mutex_unlock(&BTRFS_I(inode)->log_mutex);
+
+ btrfs_free_path(path);
+ btrfs_free_path(dst_path);
+
+ mutex_lock(&root->fs_info->tree_log_mutex);
+ ret = update_log_root(trans, log);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+out:
+ return 0;
+}
+
+int btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ int inode_only)
+{
+ int ret;
+
+ start_log_trans(trans, root);
+ ret = __btrfs_log_inode(trans, root, inode, inode_only);
+ end_log_trans(root);
+ return ret;
+}
+
+/*
+ * helper function around btrfs_log_inode to make sure newly created
+ * parent directories also end up in the log. A minimal inode and backref
+ * only logging is done of any parent directories that are older than
+ * the last committed transaction
+ */
+int btrfs_log_dentry(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct dentry *dentry)
+{
+ int inode_only = LOG_INODE_ALL;
+ struct super_block *sb;
+ int ret;
+
+ start_log_trans(trans, root);
+ sb = dentry->d_inode->i_sb;
+ while(1) {
+ ret = __btrfs_log_inode(trans, root, dentry->d_inode,
+ inode_only);
+ BUG_ON(ret);
+ inode_only = LOG_INODE_EXISTS;
+
+ dentry = dentry->d_parent;
+ if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb)
+ break;
+
+ if (BTRFS_I(dentry->d_inode)->generation <=
+ root->fs_info->last_trans_committed)
+ break;
+ }
+ end_log_trans(root);
+ return 0;
+}
+
+/*
+ * it is not safe to log dentry if the chunk root has added new
+ * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
+ * If this returns 1, you must commit the transaction to safely get your
+ * data on disk.
+ */
+int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct dentry *dentry)
+{
+ u64 gen;
+ gen = root->fs_info->last_trans_new_blockgroup;
+ if (gen > root->fs_info->last_trans_committed)
+ return 1;
+ else
+ return btrfs_log_dentry(trans, root, dentry);
+}
+
+/*
+ * should be called during mount to recover any replay any log trees
+ * from the FS
+ */
+int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_key tmp_key;
+ struct btrfs_root *log;
+ struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
+ u64 highest_inode;
+ struct walk_control wc = {
+ .process_func = process_one_buffer,
+ .stage = 0,
+ };
+
+ fs_info->log_root_recovering = 1;
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ trans = btrfs_start_transaction(fs_info->tree_root, 1);
+
+ wc.trans = trans;
+ wc.pin = 1;
+
+ walk_log_tree(trans, log_root_tree, &wc);
+
+again:
+ key.objectid = BTRFS_TREE_LOG_OBJECTID;
+ key.offset = (u64)-1;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+
+ while(1) {
+ ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ btrfs_release_path(log_root_tree, path);
+ if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ break;
+
+ log = btrfs_read_fs_root_no_radix(log_root_tree,
+ &found_key);
+ BUG_ON(!log);
+
+
+ tmp_key.objectid = found_key.offset;
+ tmp_key.type = BTRFS_ROOT_ITEM_KEY;
+ tmp_key.offset = (u64)-1;
+
+ wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
+
+ BUG_ON(!wc.replay_dest);
+
+ btrfs_record_root_in_trans(wc.replay_dest);
+ ret = walk_log_tree(trans, log, &wc);
+ BUG_ON(ret);
+
+ if (wc.stage == LOG_WALK_REPLAY_ALL) {
+ ret = fixup_inode_link_counts(trans, wc.replay_dest,
+ path);
+ BUG_ON(ret);
+ }
+ ret = btrfs_find_highest_inode(wc.replay_dest, &highest_inode);
+ if (ret == 0) {
+ wc.replay_dest->highest_inode = highest_inode;
+ wc.replay_dest->last_inode_alloc = highest_inode;
+ }
+
+ key.offset = found_key.offset - 1;
+ free_extent_buffer(log->node);
+ kfree(log);
+
+ if (found_key.offset == 0)
+ break;
+ }
+ btrfs_release_path(log_root_tree, path);
+
+ /* step one is to pin it all, step two is to replay just inodes */
+ if (wc.pin) {
+ wc.pin = 0;
+ wc.process_func = replay_one_buffer;
+ wc.stage = LOG_WALK_REPLAY_INODES;
+ goto again;
+ }
+ /* step three is to replay everything */
+ if (wc.stage < LOG_WALK_REPLAY_ALL) {
+ wc.stage++;
+ goto again;
+ }
+
+ btrfs_free_path(path);
+
+ free_extent_buffer(log_root_tree->node);
+ log_root_tree->log_root = NULL;
+ fs_info->log_root_recovering = 0;
+
+ /* step 4: commit the transaction, which also unpins the blocks */
+ btrfs_commit_transaction(trans, fs_info->tree_root);
+
+ kfree(log_root_tree);
+ return 0;
+}
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
new file mode 100644
index 0000000..b9409b3
--- /dev/null
+++ b/fs/btrfs/tree-log.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __TREE_LOG_
+#define __TREE_LOG_
+
+int btrfs_sync_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root);
+int btrfs_log_dentry(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct dentry *dentry);
+int btrfs_recover_log_trees(struct btrfs_root *tree_root);
+int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct dentry *dentry);
+int btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ int inode_only);
+int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ struct inode *dir, u64 index);
+int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ struct inode *inode, u64 dirid);
+#endif
diff --git a/fs/btrfs/version.h b/fs/btrfs/version.h
new file mode 100644
index 0000000..9bf3946
--- /dev/null
+++ b/fs/btrfs/version.h
@@ -0,0 +1,4 @@
+#ifndef __BTRFS_VERSION_H
+#define __BTRFS_VERSION_H
+#define BTRFS_BUILD_VERSION "Btrfs"
+#endif
diff --git a/fs/btrfs/version.sh b/fs/btrfs/version.sh
new file mode 100644
index 0000000..0f57f24
--- /dev/null
+++ b/fs/btrfs/version.sh
@@ -0,0 +1,43 @@
+#!/bin/bash
+#
+# determine-version -- report a useful version for releases
+#
+# Copyright 2008, Aron Griffis <agriffis@n01se.net>
+# Copyright 2008, Oracle
+# Released under the GNU GPLv2
+
+v="v0.16"
+
+which hg > /dev/null
+if [ -d .hg ] && [ $? == 0 ]; then
+ last=$(hg tags | grep -m1 -o '^v[0-9.]\+')
+
+ # now check if the repo has commits since then...
+ if [[ $(hg id -t) == $last || \
+ $(hg di -r "$last:." | awk '/^diff/{print $NF}' | sort -u) == .hgtags ]]
+ then
+ # check if it's dirty
+ if [[ $(hg id | cut -d' ' -f1) == *+ ]]; then
+ v=$last+
+ else
+ v=$last
+ fi
+ else
+ # includes dirty flag
+ v=$last+$(hg id -i)
+ fi
+fi
+
+echo "#ifndef __BUILD_VERSION" > .build-version.h
+echo "#define __BUILD_VERSION" >> .build-version.h
+echo "#define BTRFS_BUILD_VERSION \"Btrfs $v\"" >> .build-version.h
+echo "#endif" >> .build-version.h
+
+diff -q version.h .build-version.h >& /dev/null
+
+if [ $? == 0 ]; then
+ rm .build-version.h
+ exit 0
+fi
+
+mv .build-version.h version.h
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
new file mode 100644
index 0000000..ecf0633
--- /dev/null
+++ b/fs/btrfs/volumes.c
@@ -0,0 +1,3117 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#include <linux/sched.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/blkdev.h>
+#include <linux/random.h>
+#include <asm/div64.h>
+#include "ctree.h"
+#include "extent_map.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "async-thread.h"
+
+struct map_lookup {
+ u64 type;
+ int io_align;
+ int io_width;
+ int stripe_len;
+ int sector_size;
+ int num_stripes;
+ int sub_stripes;
+ struct btrfs_bio_stripe stripes[];
+};
+
+static int init_first_rw_device(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_device *device);
+static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
+
+
+#define map_lookup_size(n) (sizeof(struct map_lookup) + \
+ (sizeof(struct btrfs_bio_stripe) * (n)))
+
+static DEFINE_MUTEX(uuid_mutex);
+static LIST_HEAD(fs_uuids);
+
+void btrfs_lock_volumes(void)
+{
+ mutex_lock(&uuid_mutex);
+}
+
+void btrfs_unlock_volumes(void)
+{
+ mutex_unlock(&uuid_mutex);
+}
+
+static void lock_chunks(struct btrfs_root *root)
+{
+ mutex_lock(&root->fs_info->chunk_mutex);
+}
+
+static void unlock_chunks(struct btrfs_root *root)
+{
+ mutex_unlock(&root->fs_info->chunk_mutex);
+}
+
+int btrfs_cleanup_fs_uuids(void)
+{
+ struct btrfs_fs_devices *fs_devices;
+ struct btrfs_device *dev;
+
+ while (!list_empty(&fs_uuids)) {
+ fs_devices = list_entry(fs_uuids.next,
+ struct btrfs_fs_devices, list);
+ list_del(&fs_devices->list);
+ while(!list_empty(&fs_devices->devices)) {
+ dev = list_entry(fs_devices->devices.next,
+ struct btrfs_device, dev_list);
+ if (dev->bdev) {
+ close_bdev_excl(dev->bdev);
+ fs_devices->open_devices--;
+ }
+ fs_devices->num_devices--;
+ if (dev->writeable)
+ fs_devices->rw_devices--;
+ list_del(&dev->dev_list);
+ list_del(&dev->dev_alloc_list);
+ kfree(dev->name);
+ kfree(dev);
+ }
+ WARN_ON(fs_devices->num_devices);
+ WARN_ON(fs_devices->open_devices);
+ WARN_ON(fs_devices->rw_devices);
+ kfree(fs_devices);
+ }
+ return 0;
+}
+
+static noinline struct btrfs_device *__find_device(struct list_head *head,
+ u64 devid, u8 *uuid)
+{
+ struct btrfs_device *dev;
+ struct list_head *cur;
+
+ list_for_each(cur, head) {
+ dev = list_entry(cur, struct btrfs_device, dev_list);
+ if (dev->devid == devid &&
+ (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
+ return dev;
+ }
+ }
+ return NULL;
+}
+
+static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
+{
+ struct list_head *cur;
+ struct btrfs_fs_devices *fs_devices;
+
+ list_for_each(cur, &fs_uuids) {
+ fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
+ if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
+ return fs_devices;
+ }
+ return NULL;
+}
+
+/*
+ * we try to collect pending bios for a device so we don't get a large
+ * number of procs sending bios down to the same device. This greatly
+ * improves the schedulers ability to collect and merge the bios.
+ *
+ * But, it also turns into a long list of bios to process and that is sure
+ * to eventually make the worker thread block. The solution here is to
+ * make some progress and then put this work struct back at the end of
+ * the list if the block device is congested. This way, multiple devices
+ * can make progress from a single worker thread.
+ */
+static int noinline run_scheduled_bios(struct btrfs_device *device)
+{
+ struct bio *pending;
+ struct backing_dev_info *bdi;
+ struct btrfs_fs_info *fs_info;
+ struct bio *tail;
+ struct bio *cur;
+ int again = 0;
+ unsigned long num_run = 0;
+ unsigned long limit;
+
+ bdi = device->bdev->bd_inode->i_mapping->backing_dev_info;
+ fs_info = device->dev_root->fs_info;
+ limit = btrfs_async_submit_limit(fs_info);
+ limit = limit * 2 / 3;
+
+loop:
+ spin_lock(&device->io_lock);
+
+ /* take all the bios off the list at once and process them
+ * later on (without the lock held). But, remember the
+ * tail and other pointers so the bios can be properly reinserted
+ * into the list if we hit congestion
+ */
+ pending = device->pending_bios;
+ tail = device->pending_bio_tail;
+ WARN_ON(pending && !tail);
+ device->pending_bios = NULL;
+ device->pending_bio_tail = NULL;
+
+ /*
+ * if pending was null this time around, no bios need processing
+ * at all and we can stop. Otherwise it'll loop back up again
+ * and do an additional check so no bios are missed.
+ *
+ * device->running_pending is used to synchronize with the
+ * schedule_bio code.
+ */
+ if (pending) {
+ again = 1;
+ device->running_pending = 1;
+ } else {
+ again = 0;
+ device->running_pending = 0;
+ }
+ spin_unlock(&device->io_lock);
+
+ while(pending) {
+ cur = pending;
+ pending = pending->bi_next;
+ cur->bi_next = NULL;
+ atomic_dec(&fs_info->nr_async_bios);
+
+ if (atomic_read(&fs_info->nr_async_bios) < limit &&
+ waitqueue_active(&fs_info->async_submit_wait))
+ wake_up(&fs_info->async_submit_wait);
+
+ BUG_ON(atomic_read(&cur->bi_cnt) == 0);
+ bio_get(cur);
+ submit_bio(cur->bi_rw, cur);
+ bio_put(cur);
+ num_run++;
+
+ /*
+ * we made progress, there is more work to do and the bdi
+ * is now congested. Back off and let other work structs
+ * run instead
+ */
+ if (pending && bdi_write_congested(bdi) &&
+ fs_info->fs_devices->open_devices > 1) {
+ struct bio *old_head;
+
+ spin_lock(&device->io_lock);
+
+ old_head = device->pending_bios;
+ device->pending_bios = pending;
+ if (device->pending_bio_tail)
+ tail->bi_next = old_head;
+ else
+ device->pending_bio_tail = tail;
+
+ spin_unlock(&device->io_lock);
+ btrfs_requeue_work(&device->work);
+ goto done;
+ }
+ }
+ if (again)
+ goto loop;
+done:
+ return 0;
+}
+
+void pending_bios_fn(struct btrfs_work *work)
+{
+ struct btrfs_device *device;
+
+ device = container_of(work, struct btrfs_device, work);
+ run_scheduled_bios(device);
+}
+
+static noinline int device_list_add(const char *path,
+ struct btrfs_super_block *disk_super,
+ u64 devid, struct btrfs_fs_devices **fs_devices_ret)
+{
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *fs_devices;
+ u64 found_transid = btrfs_super_generation(disk_super);
+
+ fs_devices = find_fsid(disk_super->fsid);
+ if (!fs_devices) {
+ fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
+ if (!fs_devices)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&fs_devices->devices);
+ INIT_LIST_HEAD(&fs_devices->alloc_list);
+ list_add(&fs_devices->list, &fs_uuids);
+ memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
+ fs_devices->latest_devid = devid;
+ fs_devices->latest_trans = found_transid;
+ device = NULL;
+ } else {
+ device = __find_device(&fs_devices->devices, devid,
+ disk_super->dev_item.uuid);
+ }
+ if (!device) {
+ if (fs_devices->opened)
+ return -EBUSY;
+
+ device = kzalloc(sizeof(*device), GFP_NOFS);
+ if (!device) {
+ /* we can safely leave the fs_devices entry around */
+ return -ENOMEM;
+ }
+ device->devid = devid;
+ device->work.func = pending_bios_fn;
+ memcpy(device->uuid, disk_super->dev_item.uuid,
+ BTRFS_UUID_SIZE);
+ device->barriers = 1;
+ spin_lock_init(&device->io_lock);
+ device->name = kstrdup(path, GFP_NOFS);
+ if (!device->name) {
+ kfree(device);
+ return -ENOMEM;
+ }
+ INIT_LIST_HEAD(&device->dev_alloc_list);
+ list_add(&device->dev_list, &fs_devices->devices);
+ device->fs_devices = fs_devices;
+ fs_devices->num_devices++;
+ }
+
+ if (found_transid > fs_devices->latest_trans) {
+ fs_devices->latest_devid = devid;
+ fs_devices->latest_trans = found_transid;
+ }
+ *fs_devices_ret = fs_devices;
+ return 0;
+}
+
+int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct list_head *tmp;
+ struct list_head *cur;
+ struct btrfs_device *device;
+ int seed_devices = 0;
+
+ mutex_lock(&uuid_mutex);
+again:
+ list_for_each_safe(cur, tmp, &fs_devices->devices) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ if (device->in_fs_metadata)
+ continue;
+
+ if (device->bdev) {
+ close_bdev_excl(device->bdev);
+ device->bdev = NULL;
+ fs_devices->open_devices--;
+ }
+ if (device->writeable) {
+ list_del_init(&device->dev_alloc_list);
+ device->writeable = 0;
+ fs_devices->rw_devices--;
+ }
+ if (!seed_devices) {
+ list_del_init(&device->dev_list);
+ fs_devices->num_devices--;
+ kfree(device->name);
+ kfree(device);
+ }
+ }
+
+ if (fs_devices->seed) {
+ fs_devices = fs_devices->seed;
+ seed_devices = 1;
+ goto again;
+ }
+
+ mutex_unlock(&uuid_mutex);
+ return 0;
+}
+
+static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct btrfs_fs_devices *seed_devices;
+ struct list_head *cur;
+ struct btrfs_device *device;
+again:
+ if (--fs_devices->opened > 0)
+ return 0;
+
+ list_for_each(cur, &fs_devices->devices) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ if (device->bdev) {
+ close_bdev_excl(device->bdev);
+ fs_devices->open_devices--;
+ }
+ if (device->writeable) {
+ list_del_init(&device->dev_alloc_list);
+ fs_devices->rw_devices--;
+ }
+
+ device->bdev = NULL;
+ device->writeable = 0;
+ device->in_fs_metadata = 0;
+ }
+ fs_devices->opened = 0;
+ fs_devices->seeding = 0;
+ fs_devices->sprouted = 0;
+
+ seed_devices = fs_devices->seed;
+ fs_devices->seed = NULL;
+ if (seed_devices) {
+ fs_devices = seed_devices;
+ goto again;
+ }
+ return 0;
+}
+
+int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
+{
+ int ret;
+
+ mutex_lock(&uuid_mutex);
+ ret = __btrfs_close_devices(fs_devices);
+ mutex_unlock(&uuid_mutex);
+ return ret;
+}
+
+int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, void *holder)
+{
+ struct block_device *bdev;
+ struct list_head *head = &fs_devices->devices;
+ struct list_head *cur;
+ struct btrfs_device *device;
+ struct block_device *latest_bdev = NULL;
+ struct buffer_head *bh;
+ struct btrfs_super_block *disk_super;
+ u64 latest_devid = 0;
+ u64 latest_transid = 0;
+ u64 devid;
+ int seeding = 1;
+ int ret = 0;
+
+ list_for_each(cur, head) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ if (device->bdev)
+ continue;
+ if (!device->name)
+ continue;
+
+ bdev = open_bdev_excl(device->name, MS_RDONLY, holder);
+ if (IS_ERR(bdev)) {
+ printk("open %s failed\n", device->name);
+ goto error;
+ }
+ set_blocksize(bdev, 4096);
+
+ bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
+ if (!bh)
+ goto error_close;
+
+ disk_super = (struct btrfs_super_block *)bh->b_data;
+ if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
+ sizeof(disk_super->magic)))
+ goto error_brelse;
+
+ devid = le64_to_cpu(disk_super->dev_item.devid);
+ if (devid != device->devid)
+ goto error_brelse;
+
+ if (memcmp(device->uuid, disk_super->dev_item.uuid,
+ BTRFS_UUID_SIZE))
+ goto error_brelse;
+
+ device->generation = btrfs_super_generation(disk_super);
+ if (!latest_transid || device->generation > latest_transid) {
+ latest_devid = devid;
+ latest_transid = device->generation;
+ latest_bdev = bdev;
+ }
+
+ if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
+ device->writeable = 0;
+ } else {
+ device->writeable = !bdev_read_only(bdev);
+ seeding = 0;
+ }
+
+ device->bdev = bdev;
+ device->in_fs_metadata = 0;
+ fs_devices->open_devices++;
+ if (device->writeable) {
+ fs_devices->rw_devices++;
+ list_add(&device->dev_alloc_list,
+ &fs_devices->alloc_list);
+ }
+ continue;
+
+error_brelse:
+ brelse(bh);
+error_close:
+ close_bdev_excl(bdev);
+error:
+ continue;
+ }
+ if (fs_devices->open_devices == 0) {
+ ret = -EIO;
+ goto out;
+ }
+ fs_devices->seeding = seeding;
+ fs_devices->opened = 1;
+ fs_devices->latest_bdev = latest_bdev;
+ fs_devices->latest_devid = latest_devid;
+ fs_devices->latest_trans = latest_transid;
+ fs_devices->total_rw_bytes = 0;
+out:
+ return ret;
+}
+
+int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
+ int flags, void *holder)
+{
+ int ret;
+
+ mutex_lock(&uuid_mutex);
+ if (fs_devices->opened) {
+ if (fs_devices->sprouted) {
+ ret = -EBUSY;
+ } else {
+ fs_devices->opened++;
+ ret = 0;
+ }
+ } else {
+ ret = __btrfs_open_devices(fs_devices, holder);
+ }
+ mutex_unlock(&uuid_mutex);
+ return ret;
+}
+
+int btrfs_scan_one_device(const char *path, int flags, void *holder,
+ struct btrfs_fs_devices **fs_devices_ret)
+{
+ struct btrfs_super_block *disk_super;
+ struct block_device *bdev;
+ struct buffer_head *bh;
+ int ret;
+ u64 devid;
+ u64 transid;
+
+ mutex_lock(&uuid_mutex);
+
+ bdev = open_bdev_excl(path, flags, holder);
+
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ goto error;
+ }
+
+ ret = set_blocksize(bdev, 4096);
+ if (ret)
+ goto error_close;
+ bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
+ if (!bh) {
+ ret = -EIO;
+ goto error_close;
+ }
+ disk_super = (struct btrfs_super_block *)bh->b_data;
+ if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
+ sizeof(disk_super->magic))) {
+ ret = -EINVAL;
+ goto error_brelse;
+ }
+ devid = le64_to_cpu(disk_super->dev_item.devid);
+ transid = btrfs_super_generation(disk_super);
+ if (disk_super->label[0])
+ printk("device label %s ", disk_super->label);
+ else {
+ /* FIXME, make a readl uuid parser */
+ printk("device fsid %llx-%llx ",
+ *(unsigned long long *)disk_super->fsid,
+ *(unsigned long long *)(disk_super->fsid + 8));
+ }
+ printk("devid %Lu transid %Lu %s\n", devid, transid, path);
+ ret = device_list_add(path, disk_super, devid, fs_devices_ret);
+
+error_brelse:
+ brelse(bh);
+error_close:
+ close_bdev_excl(bdev);
+error:
+ mutex_unlock(&uuid_mutex);
+ return ret;
+}
+
+/*
+ * this uses a pretty simple search, the expectation is that it is
+ * called very infrequently and that a given device has a small number
+ * of extents
+ */
+static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device,
+ u64 num_bytes, u64 *start)
+{
+ struct btrfs_key key;
+ struct btrfs_root *root = device->dev_root;
+ struct btrfs_dev_extent *dev_extent = NULL;
+ struct btrfs_path *path;
+ u64 hole_size = 0;
+ u64 last_byte = 0;
+ u64 search_start = 0;
+ u64 search_end = device->total_bytes;
+ int ret;
+ int slot = 0;
+ int start_found;
+ struct extent_buffer *l;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->reada = 2;
+ start_found = 0;
+
+ /* FIXME use last free of some kind */
+
+ /* we don't want to overwrite the superblock on the drive,
+ * so we make sure to start at an offset of at least 1MB
+ */
+ search_start = max((u64)1024 * 1024, search_start);
+
+ if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
+ search_start = max(root->fs_info->alloc_start, search_start);
+
+ key.objectid = device->devid;
+ key.offset = search_start;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+ ret = btrfs_previous_item(root, path, 0, key.type);
+ if (ret < 0)
+ goto error;
+ l = path->nodes[0];
+ btrfs_item_key_to_cpu(l, &key, path->slots[0]);
+ while (1) {
+ l = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto error;
+no_more_items:
+ if (!start_found) {
+ if (search_start >= search_end) {
+ ret = -ENOSPC;
+ goto error;
+ }
+ *start = search_start;
+ start_found = 1;
+ goto check_pending;
+ }
+ *start = last_byte > search_start ?
+ last_byte : search_start;
+ if (search_end <= *start) {
+ ret = -ENOSPC;
+ goto error;
+ }
+ goto check_pending;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.objectid < device->devid)
+ goto next;
+
+ if (key.objectid > device->devid)
+ goto no_more_items;
+
+ if (key.offset >= search_start && key.offset > last_byte &&
+ start_found) {
+ if (last_byte < search_start)
+ last_byte = search_start;
+ hole_size = key.offset - last_byte;
+ if (key.offset > last_byte &&
+ hole_size >= num_bytes) {
+ *start = last_byte;
+ goto check_pending;
+ }
+ }
+ if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
+ goto next;
+ }
+
+ start_found = 1;
+ dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+ last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
+next:
+ path->slots[0]++;
+ cond_resched();
+ }
+check_pending:
+ /* we have to make sure we didn't find an extent that has already
+ * been allocated by the map tree or the original allocation
+ */
+ BUG_ON(*start < search_start);
+
+ if (*start + num_bytes > search_end) {
+ ret = -ENOSPC;
+ goto error;
+ }
+ /* check for pending inserts here */
+ ret = 0;
+
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device,
+ u64 start)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_root *root = device->dev_root;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf = NULL;
+ struct btrfs_dev_extent *extent = NULL;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = device->devid;
+ key.offset = start;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0) {
+ ret = btrfs_previous_item(root, path, key.objectid,
+ BTRFS_DEV_EXTENT_KEY);
+ BUG_ON(ret);
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_extent);
+ BUG_ON(found_key.offset > start || found_key.offset +
+ btrfs_dev_extent_length(leaf, extent) < start);
+ ret = 0;
+ } else if (ret == 0) {
+ leaf = path->nodes[0];
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_extent);
+ }
+ BUG_ON(ret);
+
+ if (device->bytes_used > 0)
+ device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
+ ret = btrfs_del_item(trans, root, path);
+ BUG_ON(ret);
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device,
+ u64 chunk_tree, u64 chunk_objectid,
+ u64 chunk_offset, u64 start, u64 num_bytes)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_root *root = device->dev_root;
+ struct btrfs_dev_extent *extent;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+
+ WARN_ON(!device->in_fs_metadata);
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = device->devid;
+ key.offset = start;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(*extent));
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_extent);
+ btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
+ btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
+ btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
+
+ write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
+ (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
+ BTRFS_UUID_SIZE);
+
+ btrfs_set_dev_extent_length(leaf, extent, num_bytes);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_free_path(path);
+ return ret;
+}
+
+static noinline int find_next_chunk(struct btrfs_root *root,
+ u64 objectid, u64 *offset)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_chunk *chunk;
+ struct btrfs_key found_key;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ key.objectid = objectid;
+ key.offset = (u64)-1;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+
+ BUG_ON(ret == 0);
+
+ ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
+ if (ret) {
+ *offset = 0;
+ } else {
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ if (found_key.objectid != objectid)
+ *offset = 0;
+ else {
+ chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_chunk);
+ *offset = found_key.offset +
+ btrfs_chunk_length(path->nodes[0], chunk);
+ }
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+
+ root = root->fs_info->chunk_root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+
+ BUG_ON(ret == 0);
+
+ ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
+ BTRFS_DEV_ITEM_KEY);
+ if (ret) {
+ *objectid = 1;
+ } else {
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ *objectid = found_key.offset + 1;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * the device information is stored in the chunk root
+ * the btrfs_device struct should be fully filled in
+ */
+int btrfs_add_device(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_device *device)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_dev_item *dev_item;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ unsigned long ptr;
+
+ root = root->fs_info->chunk_root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = device->devid;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(*dev_item));
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
+
+ btrfs_set_device_id(leaf, dev_item, device->devid);
+ btrfs_set_device_generation(leaf, dev_item, 0);
+ btrfs_set_device_type(leaf, dev_item, device->type);
+ btrfs_set_device_io_align(leaf, dev_item, device->io_align);
+ btrfs_set_device_io_width(leaf, dev_item, device->io_width);
+ btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
+ btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
+ btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
+ btrfs_set_device_group(leaf, dev_item, 0);
+ btrfs_set_device_seek_speed(leaf, dev_item, 0);
+ btrfs_set_device_bandwidth(leaf, dev_item, 0);
+
+ ptr = (unsigned long)btrfs_device_uuid(dev_item);
+ write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
+ ptr = (unsigned long)btrfs_device_fsid(dev_item);
+ write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int btrfs_rm_dev_item(struct btrfs_root *root,
+ struct btrfs_device *device)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_trans_handle *trans;
+
+ root = root->fs_info->chunk_root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ trans = btrfs_start_transaction(root, 1);
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = device->devid;
+ lock_chunks(root);
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret)
+ goto out;
+out:
+ btrfs_free_path(path);
+ unlock_chunks(root);
+ btrfs_commit_transaction(trans, root);
+ return ret;
+}
+
+int btrfs_rm_device(struct btrfs_root *root, char *device_path)
+{
+ struct btrfs_device *device;
+ struct btrfs_device *next_device;
+ struct block_device *bdev;
+ struct buffer_head *bh = NULL;
+ struct btrfs_super_block *disk_super;
+ u64 all_avail;
+ u64 devid;
+ u64 num_devices;
+ u8 *dev_uuid;
+ int ret = 0;
+
+ mutex_lock(&uuid_mutex);
+ mutex_lock(&root->fs_info->volume_mutex);
+
+ all_avail = root->fs_info->avail_data_alloc_bits |
+ root->fs_info->avail_system_alloc_bits |
+ root->fs_info->avail_metadata_alloc_bits;
+
+ if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
+ root->fs_info->fs_devices->rw_devices <= 4) {
+ printk("btrfs: unable to go below four devices on raid10\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
+ root->fs_info->fs_devices->rw_devices <= 2) {
+ printk("btrfs: unable to go below two devices on raid1\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (strcmp(device_path, "missing") == 0) {
+ struct list_head *cur;
+ struct list_head *devices;
+ struct btrfs_device *tmp;
+
+ device = NULL;
+ devices = &root->fs_info->fs_devices->devices;
+ list_for_each(cur, devices) {
+ tmp = list_entry(cur, struct btrfs_device, dev_list);
+ if (tmp->in_fs_metadata && !tmp->bdev) {
+ device = tmp;
+ break;
+ }
+ }
+ bdev = NULL;
+ bh = NULL;
+ disk_super = NULL;
+ if (!device) {
+ printk("btrfs: no missing devices found to remove\n");
+ goto out;
+ }
+ } else {
+ bdev = open_bdev_excl(device_path, MS_RDONLY,
+ root->fs_info->bdev_holder);
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ goto out;
+ }
+
+ set_blocksize(bdev, 4096);
+ bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
+ if (!bh) {
+ ret = -EIO;
+ goto error_close;
+ }
+ disk_super = (struct btrfs_super_block *)bh->b_data;
+ if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
+ sizeof(disk_super->magic))) {
+ ret = -ENOENT;
+ goto error_brelse;
+ }
+ devid = le64_to_cpu(disk_super->dev_item.devid);
+ dev_uuid = disk_super->dev_item.uuid;
+ device = btrfs_find_device(root, devid, dev_uuid,
+ disk_super->fsid);
+ if (!device) {
+ ret = -ENOENT;
+ goto error_brelse;
+ }
+ }
+
+ if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
+ printk("btrfs: unable to remove the only writeable device\n");
+ ret = -EINVAL;
+ goto error_brelse;
+ }
+
+ if (device->writeable) {
+ list_del_init(&device->dev_alloc_list);
+ root->fs_info->fs_devices->rw_devices--;
+ }
+
+ ret = btrfs_shrink_device(device, 0);
+ if (ret)
+ goto error_brelse;
+
+ ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
+ if (ret)
+ goto error_brelse;
+
+ device->in_fs_metadata = 0;
+ if (device->fs_devices == root->fs_info->fs_devices) {
+ list_del_init(&device->dev_list);
+ root->fs_info->fs_devices->num_devices--;
+ if (device->bdev)
+ device->fs_devices->open_devices--;
+ }
+
+ next_device = list_entry(root->fs_info->fs_devices->devices.next,
+ struct btrfs_device, dev_list);
+ if (device->bdev == root->fs_info->sb->s_bdev)
+ root->fs_info->sb->s_bdev = next_device->bdev;
+ if (device->bdev == root->fs_info->fs_devices->latest_bdev)
+ root->fs_info->fs_devices->latest_bdev = next_device->bdev;
+
+ num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
+ btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
+
+ if (device->fs_devices != root->fs_info->fs_devices) {
+ BUG_ON(device->writeable);
+ brelse(bh);
+ if (bdev)
+ close_bdev_excl(bdev);
+
+ if (device->bdev) {
+ close_bdev_excl(device->bdev);
+ device->bdev = NULL;
+ device->fs_devices->open_devices--;
+ }
+ if (device->fs_devices->open_devices == 0) {
+ struct btrfs_fs_devices *fs_devices;
+ fs_devices = root->fs_info->fs_devices;
+ while (fs_devices) {
+ if (fs_devices->seed == device->fs_devices)
+ break;
+ fs_devices = fs_devices->seed;
+ }
+ fs_devices->seed = device->fs_devices->seed;
+ device->fs_devices->seed = NULL;
+ __btrfs_close_devices(device->fs_devices);
+ }
+ ret = 0;
+ goto out;
+ }
+
+ /*
+ * at this point, the device is zero sized. We want to
+ * remove it from the devices list and zero out the old super
+ */
+ if (device->writeable) {
+ /* make sure this device isn't detected as part of
+ * the FS anymore
+ */
+ memset(&disk_super->magic, 0, sizeof(disk_super->magic));
+ set_buffer_dirty(bh);
+ sync_dirty_buffer(bh);
+ }
+ brelse(bh);
+
+ if (device->bdev) {
+ /* one close for the device struct or super_block */
+ close_bdev_excl(device->bdev);
+ }
+ if (bdev) {
+ /* one close for us */
+ close_bdev_excl(bdev);
+ }
+ kfree(device->name);
+ kfree(device);
+ ret = 0;
+ goto out;
+
+error_brelse:
+ brelse(bh);
+error_close:
+ if (bdev)
+ close_bdev_excl(bdev);
+out:
+ mutex_unlock(&root->fs_info->volume_mutex);
+ mutex_unlock(&uuid_mutex);
+ return ret;
+}
+
+/*
+ * does all the dirty work required for changing file system's UUID.
+ */
+static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+ struct btrfs_fs_devices *old_devices;
+ struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
+ struct btrfs_device *device;
+ u64 super_flags;
+
+ BUG_ON(!mutex_is_locked(&uuid_mutex));
+ if (!fs_devices->seeding || fs_devices->opened != 1)
+ return -EINVAL;
+
+ old_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
+ if (!old_devices)
+ return -ENOMEM;
+
+ memcpy(old_devices, fs_devices, sizeof(*old_devices));
+ old_devices->opened = 1;
+ old_devices->sprouted = 1;
+ INIT_LIST_HEAD(&old_devices->devices);
+ INIT_LIST_HEAD(&old_devices->alloc_list);
+ list_splice_init(&fs_devices->devices, &old_devices->devices);
+ list_splice_init(&fs_devices->alloc_list, &old_devices->alloc_list);
+ list_for_each_entry(device, &old_devices->devices, dev_list) {
+ device->fs_devices = old_devices;
+ }
+ list_add(&old_devices->list, &fs_uuids);
+
+ fs_devices->seeding = 0;
+ fs_devices->num_devices = 0;
+ fs_devices->open_devices = 0;
+ fs_devices->seed = old_devices;
+
+ generate_random_uuid(fs_devices->fsid);
+ memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+ memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+ super_flags = btrfs_super_flags(disk_super) &
+ ~BTRFS_SUPER_FLAG_SEEDING;
+ btrfs_set_super_flags(disk_super, super_flags);
+
+ return 0;
+}
+
+/*
+ * strore the expected generation for seed devices in device items.
+ */
+static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_dev_item *dev_item;
+ struct btrfs_device *device;
+ struct btrfs_key key;
+ u8 fs_uuid[BTRFS_UUID_SIZE];
+ u8 dev_uuid[BTRFS_UUID_SIZE];
+ u64 devid;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ root = root->fs_info->chunk_root;
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.offset = 0;
+ key.type = BTRFS_DEV_ITEM_KEY;
+
+ while (1) {
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0)
+ goto error;
+
+ leaf = path->nodes[0];
+next_slot:
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret > 0)
+ break;
+ if (ret < 0)
+ goto error;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ btrfs_release_path(root, path);
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
+ key.type != BTRFS_DEV_ITEM_KEY)
+ break;
+
+ dev_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_item);
+ devid = btrfs_device_id(leaf, dev_item);
+ read_extent_buffer(leaf, dev_uuid,
+ (unsigned long)btrfs_device_uuid(dev_item),
+ BTRFS_UUID_SIZE);
+ read_extent_buffer(leaf, fs_uuid,
+ (unsigned long)btrfs_device_fsid(dev_item),
+ BTRFS_UUID_SIZE);
+ device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
+ BUG_ON(!device);
+
+ if (device->fs_devices->seeding) {
+ btrfs_set_device_generation(leaf, dev_item,
+ device->generation);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+
+ path->slots[0]++;
+ goto next_slot;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_device *device;
+ struct block_device *bdev;
+ struct list_head *cur;
+ struct list_head *devices;
+ struct super_block *sb = root->fs_info->sb;
+ u64 total_bytes;
+ int seeding_dev = 0;
+ int ret = 0;
+
+ if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
+ return -EINVAL;
+
+ bdev = open_bdev_excl(device_path, 0, root->fs_info->bdev_holder);
+ if (!bdev) {
+ return -EIO;
+ }
+
+ if (root->fs_info->fs_devices->seeding) {
+ seeding_dev = 1;
+ down_write(&sb->s_umount);
+ mutex_lock(&uuid_mutex);
+ }
+
+ filemap_write_and_wait(bdev->bd_inode->i_mapping);
+ mutex_lock(&root->fs_info->volume_mutex);
+
+ devices = &root->fs_info->fs_devices->devices;
+ list_for_each(cur, devices) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ if (device->bdev == bdev) {
+ ret = -EEXIST;
+ goto error;
+ }
+ }
+
+ device = kzalloc(sizeof(*device), GFP_NOFS);
+ if (!device) {
+ /* we can safely leave the fs_devices entry around */
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ device->name = kstrdup(device_path, GFP_NOFS);
+ if (!device->name) {
+ kfree(device);
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ ret = find_next_devid(root, &device->devid);
+ if (ret) {
+ kfree(device);
+ goto error;
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ lock_chunks(root);
+
+ device->barriers = 1;
+ device->writeable = 1;
+ device->work.func = pending_bios_fn;
+ generate_random_uuid(device->uuid);
+ spin_lock_init(&device->io_lock);
+ device->generation = trans->transid;
+ device->io_width = root->sectorsize;
+ device->io_align = root->sectorsize;
+ device->sector_size = root->sectorsize;
+ device->total_bytes = i_size_read(bdev->bd_inode);
+ device->dev_root = root->fs_info->dev_root;
+ device->bdev = bdev;
+ device->in_fs_metadata = 1;
+ set_blocksize(device->bdev, 4096);
+
+ if (seeding_dev) {
+ sb->s_flags &= ~MS_RDONLY;
+ ret = btrfs_prepare_sprout(trans, root);
+ BUG_ON(ret);
+ }
+
+ device->fs_devices = root->fs_info->fs_devices;
+ list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
+ list_add(&device->dev_alloc_list,
+ &root->fs_info->fs_devices->alloc_list);
+ root->fs_info->fs_devices->num_devices++;
+ root->fs_info->fs_devices->open_devices++;
+ root->fs_info->fs_devices->rw_devices++;
+ root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
+
+ total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
+ btrfs_set_super_total_bytes(&root->fs_info->super_copy,
+ total_bytes + device->total_bytes);
+
+ total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
+ btrfs_set_super_num_devices(&root->fs_info->super_copy,
+ total_bytes + 1);
+
+ if (seeding_dev) {
+ ret = init_first_rw_device(trans, root, device);
+ BUG_ON(ret);
+ ret = btrfs_finish_sprout(trans, root);
+ BUG_ON(ret);
+ } else {
+ ret = btrfs_add_device(trans, root, device);
+ }
+
+ unlock_chunks(root);
+ btrfs_commit_transaction(trans, root);
+
+ if (seeding_dev) {
+ mutex_unlock(&uuid_mutex);
+ up_write(&sb->s_umount);
+
+ ret = btrfs_relocate_sys_chunks(root);
+ BUG_ON(ret);
+ }
+out:
+ mutex_unlock(&root->fs_info->volume_mutex);
+ return ret;
+error:
+ close_bdev_excl(bdev);
+ if (seeding_dev) {
+ mutex_unlock(&uuid_mutex);
+ up_write(&sb->s_umount);
+ }
+ goto out;
+}
+
+int noinline btrfs_update_device(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_root *root;
+ struct btrfs_dev_item *dev_item;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+
+ root = device->dev_root->fs_info->chunk_root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = device->devid;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
+
+ btrfs_set_device_id(leaf, dev_item, device->devid);
+ btrfs_set_device_type(leaf, dev_item, device->type);
+ btrfs_set_device_io_align(leaf, dev_item, device->io_align);
+ btrfs_set_device_io_width(leaf, dev_item, device->io_width);
+ btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
+ btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
+ btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
+ btrfs_mark_buffer_dirty(leaf);
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device, u64 new_size)
+{
+ struct btrfs_super_block *super_copy =
+ &device->dev_root->fs_info->super_copy;
+ u64 old_total = btrfs_super_total_bytes(super_copy);
+ u64 diff = new_size - device->total_bytes;
+
+ if (!device->writeable)
+ return -EACCES;
+ if (new_size <= device->total_bytes)
+ return -EINVAL;
+
+ btrfs_set_super_total_bytes(super_copy, old_total + diff);
+ device->fs_devices->total_rw_bytes += diff;
+
+ device->total_bytes = new_size;
+ return btrfs_update_device(trans, device);
+}
+
+int btrfs_grow_device(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device, u64 new_size)
+{
+ int ret;
+ lock_chunks(device->dev_root);
+ ret = __btrfs_grow_device(trans, device, new_size);
+ unlock_chunks(device->dev_root);
+ return ret;
+}
+
+static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 chunk_tree, u64 chunk_objectid,
+ u64 chunk_offset)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+
+ root = root->fs_info->chunk_root;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = chunk_objectid;
+ key.offset = chunk_offset;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ BUG_ON(ret);
+
+ ret = btrfs_del_item(trans, root, path);
+ BUG_ON(ret);
+
+ btrfs_free_path(path);
+ return 0;
+}
+
+int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
+ chunk_offset)
+{
+ struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
+ struct btrfs_disk_key *disk_key;
+ struct btrfs_chunk *chunk;
+ u8 *ptr;
+ int ret = 0;
+ u32 num_stripes;
+ u32 array_size;
+ u32 len = 0;
+ u32 cur;
+ struct btrfs_key key;
+
+ array_size = btrfs_super_sys_array_size(super_copy);
+
+ ptr = super_copy->sys_chunk_array;
+ cur = 0;
+
+ while (cur < array_size) {
+ disk_key = (struct btrfs_disk_key *)ptr;
+ btrfs_disk_key_to_cpu(&key, disk_key);
+
+ len = sizeof(*disk_key);
+
+ if (key.type == BTRFS_CHUNK_ITEM_KEY) {
+ chunk = (struct btrfs_chunk *)(ptr + len);
+ num_stripes = btrfs_stack_chunk_num_stripes(chunk);
+ len += btrfs_chunk_item_size(num_stripes);
+ } else {
+ ret = -EIO;
+ break;
+ }
+ if (key.objectid == chunk_objectid &&
+ key.offset == chunk_offset) {
+ memmove(ptr, ptr + len, array_size - (cur + len));
+ array_size -= len;
+ btrfs_set_super_sys_array_size(super_copy, array_size);
+ } else {
+ ptr += len;
+ cur += len;
+ }
+ }
+ return ret;
+}
+
+int btrfs_relocate_chunk(struct btrfs_root *root,
+ u64 chunk_tree, u64 chunk_objectid,
+ u64 chunk_offset)
+{
+ struct extent_map_tree *em_tree;
+ struct btrfs_root *extent_root;
+ struct btrfs_trans_handle *trans;
+ struct extent_map *em;
+ struct map_lookup *map;
+ int ret;
+ int i;
+
+ printk("btrfs relocating chunk %llu\n",
+ (unsigned long long)chunk_offset);
+ root = root->fs_info->chunk_root;
+ extent_root = root->fs_info->extent_root;
+ em_tree = &root->fs_info->mapping_tree.map_tree;
+
+ /* step one, relocate all the extents inside this chunk */
+ ret = btrfs_relocate_block_group(extent_root, chunk_offset);
+ BUG_ON(ret);
+
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+
+ lock_chunks(root);
+
+ /*
+ * step two, delete the device extents and the
+ * chunk tree entries
+ */
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, chunk_offset, 1);
+ spin_unlock(&em_tree->lock);
+
+ BUG_ON(em->start > chunk_offset ||
+ em->start + em->len < chunk_offset);
+ map = (struct map_lookup *)em->bdev;
+
+ for (i = 0; i < map->num_stripes; i++) {
+ ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
+ map->stripes[i].physical);
+ BUG_ON(ret);
+
+ if (map->stripes[i].dev) {
+ ret = btrfs_update_device(trans, map->stripes[i].dev);
+ BUG_ON(ret);
+ }
+ }
+ ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
+ chunk_offset);
+
+ BUG_ON(ret);
+
+ if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
+ BUG_ON(ret);
+ }
+
+ ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
+ BUG_ON(ret);
+
+ spin_lock(&em_tree->lock);
+ remove_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+
+ kfree(map);
+ em->bdev = NULL;
+
+ /* once for the tree */
+ free_extent_map(em);
+ /* once for us */
+ free_extent_map(em);
+
+ unlock_chunks(root);
+ btrfs_end_transaction(trans, root);
+ return 0;
+}
+
+static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
+{
+ struct btrfs_root *chunk_root = root->fs_info->chunk_root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_chunk *chunk;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u64 chunk_tree = chunk_root->root_key.objectid;
+ u64 chunk_type;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+ BUG_ON(ret == 0);
+
+ ret = btrfs_previous_item(chunk_root, path, key.objectid,
+ key.type);
+ if (ret < 0)
+ goto error;
+ if (ret > 0)
+ break;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ chunk = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_chunk);
+ chunk_type = btrfs_chunk_type(leaf, chunk);
+ btrfs_release_path(chunk_root, path);
+
+ if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
+ found_key.objectid,
+ found_key.offset);
+ BUG_ON(ret);
+ }
+
+ if (found_key.offset == 0)
+ break;
+ key.offset = found_key.offset - 1;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static u64 div_factor(u64 num, int factor)
+{
+ if (factor == 10)
+ return num;
+ num *= factor;
+ do_div(num, 10);
+ return num;
+}
+
+int btrfs_balance(struct btrfs_root *dev_root)
+{
+ int ret;
+ struct list_head *cur;
+ struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
+ struct btrfs_device *device;
+ u64 old_size;
+ u64 size_to_free;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_chunk *chunk;
+ struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key found_key;
+
+ if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
+ return -EROFS;
+
+ mutex_lock(&dev_root->fs_info->volume_mutex);
+ dev_root = dev_root->fs_info->dev_root;
+
+ /* step one make some room on all the devices */
+ list_for_each(cur, devices) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ old_size = device->total_bytes;
+ size_to_free = div_factor(old_size, 1);
+ size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
+ if (!device->writeable ||
+ device->total_bytes - device->bytes_used > size_to_free)
+ continue;
+
+ ret = btrfs_shrink_device(device, old_size - size_to_free);
+ BUG_ON(ret);
+
+ trans = btrfs_start_transaction(dev_root, 1);
+ BUG_ON(!trans);
+
+ ret = btrfs_grow_device(trans, device, old_size);
+ BUG_ON(ret);
+
+ btrfs_end_transaction(trans, dev_root);
+ }
+
+ /* step two, relocate all the chunks */
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ while(1) {
+ ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+
+ /*
+ * this shouldn't happen, it means the last relocate
+ * failed
+ */
+ if (ret == 0)
+ break;
+
+ ret = btrfs_previous_item(chunk_root, path, 0,
+ BTRFS_CHUNK_ITEM_KEY);
+ if (ret)
+ break;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ if (found_key.objectid != key.objectid)
+ break;
+
+ chunk = btrfs_item_ptr(path->nodes[0],
+ path->slots[0],
+ struct btrfs_chunk);
+ key.offset = found_key.offset;
+ /* chunk zero is special */
+ if (key.offset == 0)
+ break;
+
+ btrfs_release_path(chunk_root, path);
+ ret = btrfs_relocate_chunk(chunk_root,
+ chunk_root->root_key.objectid,
+ found_key.objectid,
+ found_key.offset);
+ BUG_ON(ret);
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ mutex_unlock(&dev_root->fs_info->volume_mutex);
+ return ret;
+}
+
+/*
+ * shrinking a device means finding all of the device extents past
+ * the new size, and then following the back refs to the chunks.
+ * The chunk relocation code actually frees the device extent
+ */
+int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = device->dev_root;
+ struct btrfs_dev_extent *dev_extent = NULL;
+ struct btrfs_path *path;
+ u64 length;
+ u64 chunk_tree;
+ u64 chunk_objectid;
+ u64 chunk_offset;
+ int ret;
+ int slot;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
+ u64 old_total = btrfs_super_total_bytes(super_copy);
+ u64 diff = device->total_bytes - new_size;
+
+ if (new_size >= device->total_bytes)
+ return -EINVAL;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ trans = btrfs_start_transaction(root, 1);
+ if (!trans) {
+ ret = -ENOMEM;
+ goto done;
+ }
+
+ path->reada = 2;
+
+ lock_chunks(root);
+
+ device->total_bytes = new_size;
+ if (device->writeable)
+ device->fs_devices->total_rw_bytes -= diff;
+ ret = btrfs_update_device(trans, device);
+ if (ret) {
+ unlock_chunks(root);
+ btrfs_end_transaction(trans, root);
+ goto done;
+ }
+ WARN_ON(diff > old_total);
+ btrfs_set_super_total_bytes(super_copy, old_total - diff);
+ unlock_chunks(root);
+ btrfs_end_transaction(trans, root);
+
+ key.objectid = device->devid;
+ key.offset = (u64)-1;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto done;
+
+ ret = btrfs_previous_item(root, path, 0, key.type);
+ if (ret < 0)
+ goto done;
+ if (ret) {
+ ret = 0;
+ goto done;
+ }
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+ btrfs_item_key_to_cpu(l, &key, path->slots[0]);
+
+ if (key.objectid != device->devid)
+ goto done;
+
+ dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+ length = btrfs_dev_extent_length(l, dev_extent);
+
+ if (key.offset + length <= new_size)
+ goto done;
+
+ chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
+ chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
+ chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
+ btrfs_release_path(root, path);
+
+ ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
+ chunk_offset);
+ if (ret)
+ goto done;
+ }
+
+done:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_key *key,
+ struct btrfs_chunk *chunk, int item_size)
+{
+ struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
+ struct btrfs_disk_key disk_key;
+ u32 array_size;
+ u8 *ptr;
+
+ array_size = btrfs_super_sys_array_size(super_copy);
+ if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
+ return -EFBIG;
+
+ ptr = super_copy->sys_chunk_array + array_size;
+ btrfs_cpu_key_to_disk(&disk_key, key);
+ memcpy(ptr, &disk_key, sizeof(disk_key));
+ ptr += sizeof(disk_key);
+ memcpy(ptr, chunk, item_size);
+ item_size += sizeof(disk_key);
+ btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
+ return 0;
+}
+
+static u64 noinline chunk_bytes_by_type(u64 type, u64 calc_size,
+ int num_stripes, int sub_stripes)
+{
+ if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
+ return calc_size;
+ else if (type & BTRFS_BLOCK_GROUP_RAID10)
+ return calc_size * (num_stripes / sub_stripes);
+ else
+ return calc_size * num_stripes;
+}
+
+static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct map_lookup **map_ret,
+ u64 *num_bytes, u64 *stripe_size,
+ u64 start, u64 type)
+{
+ struct btrfs_fs_info *info = extent_root->fs_info;
+ struct btrfs_device *device = NULL;
+ struct btrfs_fs_devices *fs_devices = info->fs_devices;
+ struct list_head *cur;
+ struct map_lookup *map = NULL;
+ struct extent_map_tree *em_tree;
+ struct extent_map *em;
+ struct list_head private_devs;
+ int min_stripe_size = 1 * 1024 * 1024;
+ u64 calc_size = 1024 * 1024 * 1024;
+ u64 max_chunk_size = calc_size;
+ u64 min_free;
+ u64 avail;
+ u64 max_avail = 0;
+ u64 dev_offset;
+ int num_stripes = 1;
+ int min_stripes = 1;
+ int sub_stripes = 0;
+ int looped = 0;
+ int ret;
+ int index;
+ int stripe_len = 64 * 1024;
+
+ if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
+ (type & BTRFS_BLOCK_GROUP_DUP)) {
+ WARN_ON(1);
+ type &= ~BTRFS_BLOCK_GROUP_DUP;
+ }
+ if (list_empty(&fs_devices->alloc_list))
+ return -ENOSPC;
+
+ if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
+ num_stripes = fs_devices->rw_devices;
+ min_stripes = 2;
+ }
+ if (type & (BTRFS_BLOCK_GROUP_DUP)) {
+ num_stripes = 2;
+ min_stripes = 2;
+ }
+ if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
+ num_stripes = min_t(u64, 2, fs_devices->rw_devices);
+ if (num_stripes < 2)
+ return -ENOSPC;
+ min_stripes = 2;
+ }
+ if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
+ num_stripes = fs_devices->rw_devices;
+ if (num_stripes < 4)
+ return -ENOSPC;
+ num_stripes &= ~(u32)1;
+ sub_stripes = 2;
+ min_stripes = 4;
+ }
+
+ if (type & BTRFS_BLOCK_GROUP_DATA) {
+ max_chunk_size = 10 * calc_size;
+ min_stripe_size = 64 * 1024 * 1024;
+ } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
+ max_chunk_size = 4 * calc_size;
+ min_stripe_size = 32 * 1024 * 1024;
+ } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ calc_size = 8 * 1024 * 1024;
+ max_chunk_size = calc_size * 2;
+ min_stripe_size = 1 * 1024 * 1024;
+ }
+
+ /* we don't want a chunk larger than 10% of writeable space */
+ max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
+ max_chunk_size);
+
+again:
+ if (!map || map->num_stripes != num_stripes) {
+ kfree(map);
+ map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+ if (!map)
+ return -ENOMEM;
+ map->num_stripes = num_stripes;
+ }
+
+ if (calc_size * num_stripes > max_chunk_size) {
+ calc_size = max_chunk_size;
+ do_div(calc_size, num_stripes);
+ do_div(calc_size, stripe_len);
+ calc_size *= stripe_len;
+ }
+ /* we don't want tiny stripes */
+ calc_size = max_t(u64, min_stripe_size, calc_size);
+
+ do_div(calc_size, stripe_len);
+ calc_size *= stripe_len;
+
+ cur = fs_devices->alloc_list.next;
+ index = 0;
+
+ if (type & BTRFS_BLOCK_GROUP_DUP)
+ min_free = calc_size * 2;
+ else
+ min_free = calc_size;
+
+ /*
+ * we add 1MB because we never use the first 1MB of the device, unless
+ * we've looped, then we are likely allocating the maximum amount of
+ * space left already
+ */
+ if (!looped)
+ min_free += 1024 * 1024;
+
+ INIT_LIST_HEAD(&private_devs);
+ while(index < num_stripes) {
+ device = list_entry(cur, struct btrfs_device, dev_alloc_list);
+ BUG_ON(!device->writeable);
+ if (device->total_bytes > device->bytes_used)
+ avail = device->total_bytes - device->bytes_used;
+ else
+ avail = 0;
+ cur = cur->next;
+
+ if (device->in_fs_metadata && avail >= min_free) {
+ ret = find_free_dev_extent(trans, device,
+ min_free, &dev_offset);
+ if (ret == 0) {
+ list_move_tail(&device->dev_alloc_list,
+ &private_devs);
+ map->stripes[index].dev = device;
+ map->stripes[index].physical = dev_offset;
+ index++;
+ if (type & BTRFS_BLOCK_GROUP_DUP) {
+ map->stripes[index].dev = device;
+ map->stripes[index].physical =
+ dev_offset + calc_size;
+ index++;
+ }
+ }
+ } else if (device->in_fs_metadata && avail > max_avail)
+ max_avail = avail;
+ if (cur == &fs_devices->alloc_list)
+ break;
+ }
+ list_splice(&private_devs, &fs_devices->alloc_list);
+ if (index < num_stripes) {
+ if (index >= min_stripes) {
+ num_stripes = index;
+ if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
+ num_stripes /= sub_stripes;
+ num_stripes *= sub_stripes;
+ }
+ looped = 1;
+ goto again;
+ }
+ if (!looped && max_avail > 0) {
+ looped = 1;
+ calc_size = max_avail;
+ goto again;
+ }
+ kfree(map);
+ return -ENOSPC;
+ }
+ map->sector_size = extent_root->sectorsize;
+ map->stripe_len = stripe_len;
+ map->io_align = stripe_len;
+ map->io_width = stripe_len;
+ map->type = type;
+ map->num_stripes = num_stripes;
+ map->sub_stripes = sub_stripes;
+
+ *map_ret = map;
+ *stripe_size = calc_size;
+ *num_bytes = chunk_bytes_by_type(type, calc_size,
+ num_stripes, sub_stripes);
+
+ em = alloc_extent_map(GFP_NOFS);
+ if (!em) {
+ kfree(map);
+ return -ENOMEM;
+ }
+ em->bdev = (struct block_device *)map;
+ em->start = start;
+ em->len = *num_bytes;
+ em->block_start = 0;
+ em->block_len = em->len;
+
+ em_tree = &extent_root->fs_info->mapping_tree.map_tree;
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ BUG_ON(ret);
+ free_extent_map(em);
+
+ ret = btrfs_make_block_group(trans, extent_root, 0, type,
+ BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+ start, *num_bytes);
+ BUG_ON(ret);
+
+ index = 0;
+ while (index < map->num_stripes) {
+ device = map->stripes[index].dev;
+ dev_offset = map->stripes[index].physical;
+
+ ret = btrfs_alloc_dev_extent(trans, device,
+ info->chunk_root->root_key.objectid,
+ BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+ start, dev_offset, calc_size);
+ BUG_ON(ret);
+ index++;
+ }
+
+ return 0;
+}
+
+static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root,
+ struct map_lookup *map, u64 chunk_offset,
+ u64 chunk_size, u64 stripe_size)
+{
+ u64 dev_offset;
+ struct btrfs_key key;
+ struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
+ struct btrfs_device *device;
+ struct btrfs_chunk *chunk;
+ struct btrfs_stripe *stripe;
+ size_t item_size = btrfs_chunk_item_size(map->num_stripes);
+ int index = 0;
+ int ret;
+
+ chunk = kzalloc(item_size, GFP_NOFS);
+ if (!chunk)
+ return -ENOMEM;
+
+ index = 0;
+ while (index < map->num_stripes) {
+ device = map->stripes[index].dev;
+ device->bytes_used += stripe_size;
+ ret = btrfs_update_device(trans, device);
+ BUG_ON(ret);
+ index++;
+ }
+
+ index = 0;
+ stripe = &chunk->stripe;
+ while (index < map->num_stripes) {
+ device = map->stripes[index].dev;
+ dev_offset = map->stripes[index].physical;
+
+ btrfs_set_stack_stripe_devid(stripe, device->devid);
+ btrfs_set_stack_stripe_offset(stripe, dev_offset);
+ memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
+ stripe++;
+ index++;
+ }
+
+ btrfs_set_stack_chunk_length(chunk, chunk_size);
+ btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
+ btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
+ btrfs_set_stack_chunk_type(chunk, map->type);
+ btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
+ btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
+ btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
+ btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
+ btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+ key.offset = chunk_offset;
+
+ ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
+ BUG_ON(ret);
+
+ if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
+ item_size);
+ BUG_ON(ret);
+ }
+ kfree(chunk);
+ return 0;
+}
+
+/*
+ * Chunk allocation falls into two parts. The first part does works
+ * that make the new allocated chunk useable, but not do any operation
+ * that modifies the chunk tree. The second part does the works that
+ * require modifying the chunk tree. This division is important for the
+ * bootstrap process of adding storage to a seed btrfs.
+ */
+int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root, u64 type)
+{
+ u64 chunk_offset;
+ u64 chunk_size;
+ u64 stripe_size;
+ struct map_lookup *map;
+ struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
+ int ret;
+
+ ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+ &chunk_offset);
+ if (ret)
+ return ret;
+
+ ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
+ &stripe_size, chunk_offset, type);
+ if (ret)
+ return ret;
+
+ ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
+ chunk_size, stripe_size);
+ BUG_ON(ret);
+ return 0;
+}
+
+static int noinline init_first_rw_device(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_device *device)
+{
+ u64 chunk_offset;
+ u64 sys_chunk_offset;
+ u64 chunk_size;
+ u64 sys_chunk_size;
+ u64 stripe_size;
+ u64 sys_stripe_size;
+ u64 alloc_profile;
+ struct map_lookup *map;
+ struct map_lookup *sys_map;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_root *extent_root = fs_info->extent_root;
+ int ret;
+
+ ret = find_next_chunk(fs_info->chunk_root,
+ BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
+ BUG_ON(ret);
+
+ alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
+ (fs_info->metadata_alloc_profile &
+ fs_info->avail_metadata_alloc_bits);
+ alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
+
+ ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
+ &stripe_size, chunk_offset, alloc_profile);
+ BUG_ON(ret);
+
+ sys_chunk_offset = chunk_offset + chunk_size;
+
+ alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
+ (fs_info->system_alloc_profile &
+ fs_info->avail_system_alloc_bits);
+ alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
+
+ ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
+ &sys_chunk_size, &sys_stripe_size,
+ sys_chunk_offset, alloc_profile);
+ BUG_ON(ret);
+
+ ret = btrfs_add_device(trans, fs_info->chunk_root, device);
+ BUG_ON(ret);
+
+ /*
+ * Modifying chunk tree needs allocating new blocks from both
+ * system block group and metadata block group. So we only can
+ * do operations require modifying the chunk tree after both
+ * block groups were created.
+ */
+ ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
+ chunk_size, stripe_size);
+ BUG_ON(ret);
+
+ ret = __finish_chunk_alloc(trans, extent_root, sys_map,
+ sys_chunk_offset, sys_chunk_size,
+ sys_stripe_size);
+ BUG_ON(ret);
+ return 0;
+}
+
+int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
+ int readonly = 0;
+ int i;
+
+ spin_lock(&map_tree->map_tree.lock);
+ em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
+ spin_unlock(&map_tree->map_tree.lock);
+ if (!em)
+ return 1;
+
+ map = (struct map_lookup *)em->bdev;
+ for (i = 0; i < map->num_stripes; i++) {
+ if (!map->stripes[i].dev->writeable) {
+ readonly = 1;
+ break;
+ }
+ }
+ free_extent_map(em);
+ return readonly;
+}
+
+void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
+{
+ extent_map_tree_init(&tree->map_tree, GFP_NOFS);
+}
+
+void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
+{
+ struct extent_map *em;
+
+ while(1) {
+ spin_lock(&tree->map_tree.lock);
+ em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
+ if (em)
+ remove_extent_mapping(&tree->map_tree, em);
+ spin_unlock(&tree->map_tree.lock);
+ if (!em)
+ break;
+ kfree(em->bdev);
+ /* once for us */
+ free_extent_map(em);
+ /* once for the tree */
+ free_extent_map(em);
+ }
+}
+
+int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ struct extent_map_tree *em_tree = &map_tree->map_tree;
+ int ret;
+
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, logical, len);
+ spin_unlock(&em_tree->lock);
+ BUG_ON(!em);
+
+ BUG_ON(em->start > logical || em->start + em->len < logical);
+ map = (struct map_lookup *)em->bdev;
+ if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
+ ret = map->num_stripes;
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
+ ret = map->sub_stripes;
+ else
+ ret = 1;
+ free_extent_map(em);
+ return ret;
+}
+
+static int find_live_mirror(struct map_lookup *map, int first, int num,
+ int optimal)
+{
+ int i;
+ if (map->stripes[optimal].dev->bdev)
+ return optimal;
+ for (i = first; i < first + num; i++) {
+ if (map->stripes[i].dev->bdev)
+ return i;
+ }
+ /* we couldn't find one that doesn't fail. Just return something
+ * and the io error handling code will clean up eventually
+ */
+ return optimal;
+}
+
+static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
+ u64 logical, u64 *length,
+ struct btrfs_multi_bio **multi_ret,
+ int mirror_num, struct page *unplug_page)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ struct extent_map_tree *em_tree = &map_tree->map_tree;
+ u64 offset;
+ u64 stripe_offset;
+ u64 stripe_nr;
+ int stripes_allocated = 8;
+ int stripes_required = 1;
+ int stripe_index;
+ int i;
+ int num_stripes;
+ int max_errors = 0;
+ struct btrfs_multi_bio *multi = NULL;
+
+ if (multi_ret && !(rw & (1 << BIO_RW))) {
+ stripes_allocated = 1;
+ }
+again:
+ if (multi_ret) {
+ multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
+ GFP_NOFS);
+ if (!multi)
+ return -ENOMEM;
+
+ atomic_set(&multi->error, 0);
+ }
+
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, logical, *length);
+ spin_unlock(&em_tree->lock);
+
+ if (!em && unplug_page)
+ return 0;
+
+ if (!em) {
+ printk("unable to find logical %Lu len %Lu\n", logical, *length);
+ BUG();
+ }
+
+ BUG_ON(em->start > logical || em->start + em->len < logical);
+ map = (struct map_lookup *)em->bdev;
+ offset = logical - em->start;
+
+ if (mirror_num > map->num_stripes)
+ mirror_num = 0;
+
+ /* if our multi bio struct is too small, back off and try again */
+ if (rw & (1 << BIO_RW)) {
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_DUP)) {
+ stripes_required = map->num_stripes;
+ max_errors = 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+ stripes_required = map->sub_stripes;
+ max_errors = 1;
+ }
+ }
+ if (multi_ret && rw == WRITE &&
+ stripes_allocated < stripes_required) {
+ stripes_allocated = map->num_stripes;
+ free_extent_map(em);
+ kfree(multi);
+ goto again;
+ }
+ stripe_nr = offset;
+ /*
+ * stripe_nr counts the total number of stripes we have to stride
+ * to get to this block
+ */
+ do_div(stripe_nr, map->stripe_len);
+
+ stripe_offset = stripe_nr * map->stripe_len;
+ BUG_ON(offset < stripe_offset);
+
+ /* stripe_offset is the offset of this block in its stripe*/
+ stripe_offset = offset - stripe_offset;
+
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_DUP)) {
+ /* we limit the length of each bio to what fits in a stripe */
+ *length = min_t(u64, em->len - offset,
+ map->stripe_len - stripe_offset);
+ } else {
+ *length = em->len - offset;
+ }
+
+ if (!multi_ret && !unplug_page)
+ goto out;
+
+ num_stripes = 1;
+ stripe_index = 0;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
+ if (unplug_page || (rw & (1 << BIO_RW)))
+ num_stripes = map->num_stripes;
+ else if (mirror_num)
+ stripe_index = mirror_num - 1;
+ else {
+ stripe_index = find_live_mirror(map, 0,
+ map->num_stripes,
+ current->pid % map->num_stripes);
+ }
+
+ } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
+ if (rw & (1 << BIO_RW))
+ num_stripes = map->num_stripes;
+ else if (mirror_num)
+ stripe_index = mirror_num - 1;
+
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+ int factor = map->num_stripes / map->sub_stripes;
+
+ stripe_index = do_div(stripe_nr, factor);
+ stripe_index *= map->sub_stripes;
+
+ if (unplug_page || (rw & (1 << BIO_RW)))
+ num_stripes = map->sub_stripes;
+ else if (mirror_num)
+ stripe_index += mirror_num - 1;
+ else {
+ stripe_index = find_live_mirror(map, stripe_index,
+ map->sub_stripes, stripe_index +
+ current->pid % map->sub_stripes);
+ }
+ } else {
+ /*
+ * after this do_div call, stripe_nr is the number of stripes
+ * on this device we have to walk to find the data, and
+ * stripe_index is the number of our device in the stripe array
+ */
+ stripe_index = do_div(stripe_nr, map->num_stripes);
+ }
+ BUG_ON(stripe_index >= map->num_stripes);
+
+ for (i = 0; i < num_stripes; i++) {
+ if (unplug_page) {
+ struct btrfs_device *device;
+ struct backing_dev_info *bdi;
+
+ device = map->stripes[stripe_index].dev;
+ if (device->bdev) {
+ bdi = blk_get_backing_dev_info(device->bdev);
+ if (bdi->unplug_io_fn) {
+ bdi->unplug_io_fn(bdi, unplug_page);
+ }
+ }
+ } else {
+ multi->stripes[i].physical =
+ map->stripes[stripe_index].physical +
+ stripe_offset + stripe_nr * map->stripe_len;
+ multi->stripes[i].dev = map->stripes[stripe_index].dev;
+ }
+ stripe_index++;
+ }
+ if (multi_ret) {
+ *multi_ret = multi;
+ multi->num_stripes = num_stripes;
+ multi->max_errors = max_errors;
+ }
+out:
+ free_extent_map(em);
+ return 0;
+}
+
+int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
+ u64 logical, u64 *length,
+ struct btrfs_multi_bio **multi_ret, int mirror_num)
+{
+ return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
+ mirror_num, NULL);
+}
+
+int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
+ u64 logical, struct page *page)
+{
+ u64 length = PAGE_CACHE_SIZE;
+ return __btrfs_map_block(map_tree, READ, logical, &length,
+ NULL, 0, page);
+}
+
+
+static void end_bio_multi_stripe(struct bio *bio, int err)
+{
+ struct btrfs_multi_bio *multi = bio->bi_private;
+ int is_orig_bio = 0;
+
+ if (err)
+ atomic_inc(&multi->error);
+
+ if (bio == multi->orig_bio)
+ is_orig_bio = 1;
+
+ if (atomic_dec_and_test(&multi->stripes_pending)) {
+ if (!is_orig_bio) {
+ bio_put(bio);
+ bio = multi->orig_bio;
+ }
+ bio->bi_private = multi->private;
+ bio->bi_end_io = multi->end_io;
+ /* only send an error to the higher layers if it is
+ * beyond the tolerance of the multi-bio
+ */
+ if (atomic_read(&multi->error) > multi->max_errors) {
+ err = -EIO;
+ } else if (err) {
+ /*
+ * this bio is actually up to date, we didn't
+ * go over the max number of errors
+ */
+ set_bit(BIO_UPTODATE, &bio->bi_flags);
+ err = 0;
+ }
+ kfree(multi);
+
+ bio_endio(bio, err);
+ } else if (!is_orig_bio) {
+ bio_put(bio);
+ }
+}
+
+struct async_sched {
+ struct bio *bio;
+ int rw;
+ struct btrfs_fs_info *info;
+ struct btrfs_work work;
+};
+
+/*
+ * see run_scheduled_bios for a description of why bios are collected for
+ * async submit.
+ *
+ * This will add one bio to the pending list for a device and make sure
+ * the work struct is scheduled.
+ */
+static int noinline schedule_bio(struct btrfs_root *root,
+ struct btrfs_device *device,
+ int rw, struct bio *bio)
+{
+ int should_queue = 1;
+
+ /* don't bother with additional async steps for reads, right now */
+ if (!(rw & (1 << BIO_RW))) {
+ bio_get(bio);
+ submit_bio(rw, bio);
+ bio_put(bio);
+ return 0;
+ }
+
+ /*
+ * nr_async_bios allows us to reliably return congestion to the
+ * higher layers. Otherwise, the async bio makes it appear we have
+ * made progress against dirty pages when we've really just put it
+ * on a queue for later
+ */
+ atomic_inc(&root->fs_info->nr_async_bios);
+ WARN_ON(bio->bi_next);
+ bio->bi_next = NULL;
+ bio->bi_rw |= rw;
+
+ spin_lock(&device->io_lock);
+
+ if (device->pending_bio_tail)
+ device->pending_bio_tail->bi_next = bio;
+
+ device->pending_bio_tail = bio;
+ if (!device->pending_bios)
+ device->pending_bios = bio;
+ if (device->running_pending)
+ should_queue = 0;
+
+ spin_unlock(&device->io_lock);
+
+ if (should_queue)
+ btrfs_queue_worker(&root->fs_info->submit_workers,
+ &device->work);
+ return 0;
+}
+
+int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
+ int mirror_num, int async_submit)
+{
+ struct btrfs_mapping_tree *map_tree;
+ struct btrfs_device *dev;
+ struct bio *first_bio = bio;
+ u64 logical = (u64)bio->bi_sector << 9;
+ u64 length = 0;
+ u64 map_length;
+ struct btrfs_multi_bio *multi = NULL;
+ int ret;
+ int dev_nr = 0;
+ int total_devs = 1;
+
+ length = bio->bi_size;
+ map_tree = &root->fs_info->mapping_tree;
+ map_length = length;
+
+ ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
+ mirror_num);
+ BUG_ON(ret);
+
+ total_devs = multi->num_stripes;
+ if (map_length < length) {
+ printk("mapping failed logical %Lu bio len %Lu "
+ "len %Lu\n", logical, length, map_length);
+ BUG();
+ }
+ multi->end_io = first_bio->bi_end_io;
+ multi->private = first_bio->bi_private;
+ multi->orig_bio = first_bio;
+ atomic_set(&multi->stripes_pending, multi->num_stripes);
+
+ while(dev_nr < total_devs) {
+ if (total_devs > 1) {
+ if (dev_nr < total_devs - 1) {
+ bio = bio_clone(first_bio, GFP_NOFS);
+ BUG_ON(!bio);
+ } else {
+ bio = first_bio;
+ }
+ bio->bi_private = multi;
+ bio->bi_end_io = end_bio_multi_stripe;
+ }
+ bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
+ dev = multi->stripes[dev_nr].dev;
+ BUG_ON(rw == WRITE && !dev->writeable);
+ if (dev && dev->bdev) {
+ bio->bi_bdev = dev->bdev;
+ if (async_submit)
+ schedule_bio(root, dev, rw, bio);
+ else
+ submit_bio(rw, bio);
+ } else {
+ bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
+ bio->bi_sector = logical >> 9;
+ bio_endio(bio, -EIO);
+ }
+ dev_nr++;
+ }
+ if (total_devs == 1)
+ kfree(multi);
+ return 0;
+}
+
+struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
+ u8 *uuid, u8 *fsid)
+{
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *cur_devices;
+
+ cur_devices = root->fs_info->fs_devices;
+ while (cur_devices) {
+ if (!fsid ||
+ !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
+ device = __find_device(&cur_devices->devices,
+ devid, uuid);
+ if (device)
+ return device;
+ }
+ cur_devices = cur_devices->seed;
+ }
+ return NULL;
+}
+
+static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
+ u64 devid, u8 *dev_uuid)
+{
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+
+ device = kzalloc(sizeof(*device), GFP_NOFS);
+ if (!device)
+ return NULL;
+ list_add(&device->dev_list,
+ &fs_devices->devices);
+ device->barriers = 1;
+ device->dev_root = root->fs_info->dev_root;
+ device->devid = devid;
+ device->work.func = pending_bios_fn;
+ fs_devices->num_devices++;
+ spin_lock_init(&device->io_lock);
+ memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
+ return device;
+}
+
+static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
+ struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk)
+{
+ struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
+ struct map_lookup *map;
+ struct extent_map *em;
+ u64 logical;
+ u64 length;
+ u64 devid;
+ u8 uuid[BTRFS_UUID_SIZE];
+ int num_stripes;
+ int ret;
+ int i;
+
+ logical = key->offset;
+ length = btrfs_chunk_length(leaf, chunk);
+
+ spin_lock(&map_tree->map_tree.lock);
+ em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
+ spin_unlock(&map_tree->map_tree.lock);
+
+ /* already mapped? */
+ if (em && em->start <= logical && em->start + em->len > logical) {
+ free_extent_map(em);
+ return 0;
+ } else if (em) {
+ free_extent_map(em);
+ }
+
+ map = kzalloc(sizeof(*map), GFP_NOFS);
+ if (!map)
+ return -ENOMEM;
+
+ em = alloc_extent_map(GFP_NOFS);
+ if (!em)
+ return -ENOMEM;
+ num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+ map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+ if (!map) {
+ free_extent_map(em);
+ return -ENOMEM;
+ }
+
+ em->bdev = (struct block_device *)map;
+ em->start = logical;
+ em->len = length;
+ em->block_start = 0;
+ em->block_len = em->len;
+
+ map->num_stripes = num_stripes;
+ map->io_width = btrfs_chunk_io_width(leaf, chunk);
+ map->io_align = btrfs_chunk_io_align(leaf, chunk);
+ map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
+ map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
+ map->type = btrfs_chunk_type(leaf, chunk);
+ map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
+ for (i = 0; i < num_stripes; i++) {
+ map->stripes[i].physical =
+ btrfs_stripe_offset_nr(leaf, chunk, i);
+ devid = btrfs_stripe_devid_nr(leaf, chunk, i);
+ read_extent_buffer(leaf, uuid, (unsigned long)
+ btrfs_stripe_dev_uuid_nr(chunk, i),
+ BTRFS_UUID_SIZE);
+ map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
+ NULL);
+ if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
+ kfree(map);
+ free_extent_map(em);
+ return -EIO;
+ }
+ if (!map->stripes[i].dev) {
+ map->stripes[i].dev =
+ add_missing_dev(root, devid, uuid);
+ if (!map->stripes[i].dev) {
+ kfree(map);
+ free_extent_map(em);
+ return -EIO;
+ }
+ }
+ map->stripes[i].dev->in_fs_metadata = 1;
+ }
+
+ spin_lock(&map_tree->map_tree.lock);
+ ret = add_extent_mapping(&map_tree->map_tree, em);
+ spin_unlock(&map_tree->map_tree.lock);
+ BUG_ON(ret);
+ free_extent_map(em);
+
+ return 0;
+}
+
+static int fill_device_from_item(struct extent_buffer *leaf,
+ struct btrfs_dev_item *dev_item,
+ struct btrfs_device *device)
+{
+ unsigned long ptr;
+
+ device->devid = btrfs_device_id(leaf, dev_item);
+ device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
+ device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
+ device->type = btrfs_device_type(leaf, dev_item);
+ device->io_align = btrfs_device_io_align(leaf, dev_item);
+ device->io_width = btrfs_device_io_width(leaf, dev_item);
+ device->sector_size = btrfs_device_sector_size(leaf, dev_item);
+
+ ptr = (unsigned long)btrfs_device_uuid(dev_item);
+ read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
+
+ return 0;
+}
+
+static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
+{
+ struct btrfs_fs_devices *fs_devices;
+ int ret;
+
+ mutex_lock(&uuid_mutex);
+
+ fs_devices = root->fs_info->fs_devices->seed;
+ while (fs_devices) {
+ if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
+ ret = 0;
+ goto out;
+ }
+ fs_devices = fs_devices->seed;
+ }
+
+ fs_devices = find_fsid(fsid);
+ if (!fs_devices) {
+ ret = -ENOENT;
+ goto out;
+ }
+ if (fs_devices->opened) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ret = __btrfs_open_devices(fs_devices, root->fs_info->bdev_holder);
+ if (ret)
+ goto out;
+
+ if (!fs_devices->seeding) {
+ __btrfs_close_devices(fs_devices);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ fs_devices->seed = root->fs_info->fs_devices->seed;
+ root->fs_info->fs_devices->seed = fs_devices;
+ fs_devices->sprouted = 1;
+out:
+ mutex_unlock(&uuid_mutex);
+ return ret;
+}
+
+static int read_one_dev(struct btrfs_root *root,
+ struct extent_buffer *leaf,
+ struct btrfs_dev_item *dev_item)
+{
+ struct btrfs_device *device;
+ u64 devid;
+ int ret;
+ int seed_devices = 0;
+ u8 fs_uuid[BTRFS_UUID_SIZE];
+ u8 dev_uuid[BTRFS_UUID_SIZE];
+
+ devid = btrfs_device_id(leaf, dev_item);
+ read_extent_buffer(leaf, dev_uuid,
+ (unsigned long)btrfs_device_uuid(dev_item),
+ BTRFS_UUID_SIZE);
+ read_extent_buffer(leaf, fs_uuid,
+ (unsigned long)btrfs_device_fsid(dev_item),
+ BTRFS_UUID_SIZE);
+
+ if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
+ ret = open_seed_devices(root, fs_uuid);
+ if (ret)
+ return ret;
+ seed_devices = 1;
+ }
+
+ device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
+ if (!device || !device->bdev) {
+ if (!btrfs_test_opt(root, DEGRADED) || seed_devices)
+ return -EIO;
+
+ if (!device) {
+ printk("warning devid %Lu missing\n", devid);
+ device = add_missing_dev(root, devid, dev_uuid);
+ if (!device)
+ return -ENOMEM;
+ }
+ }
+
+ if (device->fs_devices != root->fs_info->fs_devices) {
+ BUG_ON(device->writeable);
+ if (device->generation !=
+ btrfs_device_generation(leaf, dev_item))
+ return -EINVAL;
+ }
+
+ fill_device_from_item(leaf, dev_item, device);
+ device->dev_root = root->fs_info->dev_root;
+ device->in_fs_metadata = 1;
+ if (device->writeable)
+ device->fs_devices->total_rw_bytes += device->total_bytes;
+ ret = 0;
+#if 0
+ ret = btrfs_open_device(device);
+ if (ret) {
+ kfree(device);
+ }
+#endif
+ return ret;
+}
+
+int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
+{
+ struct btrfs_dev_item *dev_item;
+
+ dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
+ dev_item);
+ return read_one_dev(root, buf, dev_item);
+}
+
+int btrfs_read_sys_array(struct btrfs_root *root)
+{
+ struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
+ struct extent_buffer *sb;
+ struct btrfs_disk_key *disk_key;
+ struct btrfs_chunk *chunk;
+ u8 *ptr;
+ unsigned long sb_ptr;
+ int ret = 0;
+ u32 num_stripes;
+ u32 array_size;
+ u32 len = 0;
+ u32 cur;
+ struct btrfs_key key;
+
+ sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
+ BTRFS_SUPER_INFO_SIZE);
+ if (!sb)
+ return -ENOMEM;
+ btrfs_set_buffer_uptodate(sb);
+ write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
+ array_size = btrfs_super_sys_array_size(super_copy);
+
+ ptr = super_copy->sys_chunk_array;
+ sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
+ cur = 0;
+
+ while (cur < array_size) {
+ disk_key = (struct btrfs_disk_key *)ptr;
+ btrfs_disk_key_to_cpu(&key, disk_key);
+
+ len = sizeof(*disk_key); ptr += len;
+ sb_ptr += len;
+ cur += len;
+
+ if (key.type == BTRFS_CHUNK_ITEM_KEY) {
+ chunk = (struct btrfs_chunk *)sb_ptr;
+ ret = read_one_chunk(root, &key, sb, chunk);
+ if (ret)
+ break;
+ num_stripes = btrfs_chunk_num_stripes(sb, chunk);
+ len = btrfs_chunk_item_size(num_stripes);
+ } else {
+ ret = -EIO;
+ break;
+ }
+ ptr += len;
+ sb_ptr += len;
+ cur += len;
+ }
+ free_extent_buffer(sb);
+ return ret;
+}
+
+int btrfs_read_chunk_tree(struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ int ret;
+ int slot;
+
+ root = root->fs_info->chunk_root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /* first we search for all of the device items, and then we
+ * read in all of the chunk items. This way we can create chunk
+ * mappings that reference all of the devices that are afound
+ */
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.offset = 0;
+ key.type = 0;
+again:
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ while(1) {
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto error;
+ break;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
+ if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
+ break;
+ if (found_key.type == BTRFS_DEV_ITEM_KEY) {
+ struct btrfs_dev_item *dev_item;
+ dev_item = btrfs_item_ptr(leaf, slot,
+ struct btrfs_dev_item);
+ ret = read_one_dev(root, leaf, dev_item);
+ if (ret)
+ goto error;
+ }
+ } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
+ struct btrfs_chunk *chunk;
+ chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+ ret = read_one_chunk(root, &found_key, leaf, chunk);
+ if (ret)
+ goto error;
+ }
+ path->slots[0]++;
+ }
+ if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
+ key.objectid = 0;
+ btrfs_release_path(root, path);
+ goto again;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
new file mode 100644
index 0000000..1f6f25a
--- /dev/null
+++ b/fs/btrfs/volumes.h
@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_VOLUMES_
+#define __BTRFS_VOLUMES_
+
+#include <linux/bio.h>
+#include "async-thread.h"
+
+struct buffer_head;
+struct btrfs_device {
+ struct list_head dev_list;
+ struct list_head dev_alloc_list;
+ struct btrfs_fs_devices *fs_devices;
+ struct btrfs_root *dev_root;
+ struct buffer_head *pending_io;
+ struct bio *pending_bios;
+ struct bio *pending_bio_tail;
+ int running_pending;
+ u64 generation;
+
+ int barriers;
+ int writeable;
+ int in_fs_metadata;
+
+ spinlock_t io_lock;
+
+ struct block_device *bdev;
+
+ char *name;
+
+ /* the internal btrfs device id */
+ u64 devid;
+
+ /* size of the device */
+ u64 total_bytes;
+
+ /* bytes used */
+ u64 bytes_used;
+
+ /* optimal io alignment for this device */
+ u32 io_align;
+
+ /* optimal io width for this device */
+ u32 io_width;
+
+ /* minimal io size for this device */
+ u32 sector_size;
+
+ /* type and info about this device */
+ u64 type;
+
+ /* physical drive uuid (or lvm uuid) */
+ u8 uuid[BTRFS_UUID_SIZE];
+
+ struct btrfs_work work;
+};
+
+struct btrfs_fs_devices {
+ u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+
+ /* the device with this id has the most recent coyp of the super */
+ u64 latest_devid;
+ u64 latest_trans;
+ u64 num_devices;
+ u64 open_devices;
+ u64 rw_devices;
+ u64 total_rw_bytes;
+ struct block_device *latest_bdev;
+ /* all of the devices in the FS */
+ struct list_head devices;
+
+ /* devices not currently being allocated */
+ struct list_head alloc_list;
+ struct list_head list;
+
+ struct btrfs_fs_devices *seed;
+ int seeding;
+ int sprouted;
+
+ int opened;
+};
+
+struct btrfs_bio_stripe {
+ struct btrfs_device *dev;
+ u64 physical;
+};
+
+struct btrfs_multi_bio {
+ atomic_t stripes_pending;
+ bio_end_io_t *end_io;
+ struct bio *orig_bio;
+ void *private;
+ atomic_t error;
+ int max_errors;
+ int num_stripes;
+ struct btrfs_bio_stripe stripes[];
+};
+
+#define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
+ (sizeof(struct btrfs_bio_stripe) * (n)))
+
+int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device,
+ u64 chunk_tree, u64 chunk_objectid,
+ u64 chunk_offset, u64 start, u64 num_bytes);
+int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
+ u64 logical, u64 *length,
+ struct btrfs_multi_bio **multi_ret, int mirror_num);
+int btrfs_read_sys_array(struct btrfs_root *root);
+int btrfs_read_chunk_tree(struct btrfs_root *root);
+int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root, u64 type);
+void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
+void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
+int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
+ int mirror_num, int async_submit);
+int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
+int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
+ int flags, void *holder);
+int btrfs_scan_one_device(const char *path, int flags, void *holder,
+ struct btrfs_fs_devices **fs_devices_ret);
+int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
+int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
+int btrfs_add_device(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_device *device);
+int btrfs_rm_device(struct btrfs_root *root, char *device_path);
+int btrfs_cleanup_fs_uuids(void);
+int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
+int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
+ u64 logical, struct page *page);
+int btrfs_grow_device(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device, u64 new_size);
+struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
+ u8 *uuid, u8 *fsid);
+int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
+int btrfs_init_new_device(struct btrfs_root *root, char *path);
+int btrfs_balance(struct btrfs_root *dev_root);
+void btrfs_unlock_volumes(void);
+void btrfs_lock_volumes(void);
+int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
+#endif
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
new file mode 100644
index 0000000..adb4b32
--- /dev/null
+++ b/fs/btrfs/xattr.c
@@ -0,0 +1,321 @@
+/*
+ * Copyright (C) 2007 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/rwsem.h>
+#include <linux/xattr.h>
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "transaction.h"
+#include "xattr.h"
+#include "disk-io.h"
+
+
+ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ struct btrfs_dir_item *di;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int ret = 0;
+ unsigned long data_ptr;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /* lookup the xattr by name */
+ di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
+ strlen(name), 0);
+ if (!di || IS_ERR(di)) {
+ ret = -ENODATA;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ /* if size is 0, that means we want the size of the attr */
+ if (!size) {
+ ret = btrfs_dir_data_len(leaf, di);
+ goto out;
+ }
+
+ /* now get the data out of our dir_item */
+ if (btrfs_dir_data_len(leaf, di) > size) {
+ ret = -ERANGE;
+ goto out;
+ }
+ data_ptr = (unsigned long)((char *)(di + 1) +
+ btrfs_dir_name_len(leaf, di));
+ read_extent_buffer(leaf, buffer, data_ptr,
+ btrfs_dir_data_len(leaf, di));
+ ret = btrfs_dir_data_len(leaf, di);
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int __btrfs_setxattr(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ struct btrfs_dir_item *di;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_path *path;
+ int ret = 0, mod = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ /* first lets see if we already have this xattr */
+ di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name,
+ strlen(name), -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ }
+
+ /* ok we already have this xattr, lets remove it */
+ if (di) {
+ /* if we want create only exit */
+ if (flags & XATTR_CREATE) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ if (ret)
+ goto out;
+ btrfs_release_path(root, path);
+
+ /* if we don't have a value then we are removing the xattr */
+ if (!value) {
+ mod = 1;
+ goto out;
+ }
+ } else {
+ btrfs_release_path(root, path);
+
+ if (flags & XATTR_REPLACE) {
+ /* we couldn't find the attr to replace */
+ ret = -ENODATA;
+ goto out;
+ }
+ }
+
+ /* ok we have to create a completely new xattr */
+ ret = btrfs_insert_xattr_item(trans, root, name, strlen(name),
+ value, size, inode->i_ino);
+ if (ret)
+ goto out;
+ mod = 1;
+
+out:
+ if (mod) {
+ inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_update_inode(trans, root, inode);
+ }
+
+ btrfs_end_transaction(trans, root);
+ btrfs_free_path(path);
+ return ret;
+}
+
+ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+ struct btrfs_key key, found_key;
+ struct inode *inode = dentry->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_path *path;
+ struct btrfs_item *item;
+ struct extent_buffer *leaf;
+ struct btrfs_dir_item *di;
+ int ret = 0, slot, advance;
+ size_t total_size = 0, size_left = size;
+ unsigned long name_ptr;
+ size_t name_len;
+ u32 nritems;
+
+ /*
+ * ok we want all objects associated with this id.
+ * NOTE: we set key.offset = 0; because we want to start with the
+ * first xattr that we find and walk forward
+ */
+ key.objectid = inode->i_ino;
+ btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+ key.offset = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->reada = 2;
+
+ /* search for our xattrs */
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+ ret = 0;
+ advance = 0;
+ while (1) {
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+
+ /* this is where we start walking through the path */
+ if (advance || slot >= nritems) {
+ /*
+ * if we've reached the last slot in this leaf we need
+ * to go to the next leaf and reset everything
+ */
+ if (slot >= nritems-1) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ break;
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ slot = path->slots[0];
+ } else {
+ /*
+ * just walking through the slots on this leaf
+ */
+ slot++;
+ path->slots[0]++;
+ }
+ }
+ advance = 1;
+
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ /* check to make sure this item is what we want */
+ if (found_key.objectid != key.objectid)
+ break;
+ if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
+ break;
+
+ di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+
+ name_len = btrfs_dir_name_len(leaf, di);
+ total_size += name_len + 1;
+
+ /* we are just looking for how big our buffer needs to be */
+ if (!size)
+ continue;
+
+ if (!buffer || (name_len + 1) > size_left) {
+ ret = -ERANGE;
+ break;
+ }
+
+ name_ptr = (unsigned long)(di + 1);
+ read_extent_buffer(leaf, buffer, name_ptr, name_len);
+ buffer[name_len] = '\0';
+
+ size_left -= name_len + 1;
+ buffer += name_len + 1;
+ }
+ ret = total_size;
+
+err:
+ btrfs_free_path(path);
+
+ return ret;
+}
+
+/*
+ * List of handlers for synthetic system.* attributes. All real ondisk
+ * attributes are handled directly.
+ */
+struct xattr_handler *btrfs_xattr_handlers[] = {
+#ifdef CONFIG_FS_POSIX_ACL
+ &btrfs_xattr_acl_access_handler,
+ &btrfs_xattr_acl_default_handler,
+#endif
+ NULL,
+};
+
+/*
+ * Check if the attribute is in a supported namespace.
+ *
+ * This applied after the check for the synthetic attributes in the system
+ * namespace.
+ */
+static bool btrfs_is_valid_xattr(const char *name)
+{
+ return !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) ||
+ !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) ||
+ !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
+ !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+}
+
+ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
+{
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_getxattr(dentry, name, buffer, size);
+
+ if (!btrfs_is_valid_xattr(name))
+ return -EOPNOTSUPP;
+ return __btrfs_getxattr(dentry->d_inode, name, buffer, size);
+}
+
+int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
+ size_t size, int flags)
+{
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_setxattr(dentry, name, value, size, flags);
+
+ if (!btrfs_is_valid_xattr(name))
+ return -EOPNOTSUPP;
+
+ if (size == 0)
+ value = ""; /* empty EA, do not remove */
+ return __btrfs_setxattr(dentry->d_inode, name, value, size, flags);
+}
+
+int btrfs_removexattr(struct dentry *dentry, const char *name)
+{
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_removexattr(dentry, name);
+
+ if (!btrfs_is_valid_xattr(name))
+ return -EOPNOTSUPP;
+ return __btrfs_setxattr(dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
+}
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
new file mode 100644
index 0000000..5b1d08f
--- /dev/null
+++ b/fs/btrfs/xattr.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2007 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __XATTR__
+#define __XATTR__
+
+#include <linux/xattr.h>
+
+extern struct xattr_handler btrfs_xattr_acl_access_handler;
+extern struct xattr_handler btrfs_xattr_acl_default_handler;
+extern struct xattr_handler *btrfs_xattr_handlers[];
+
+extern ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
+ void *buffer, size_t size);
+extern int __btrfs_setxattr(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags);
+
+extern ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
+ void *buffer, size_t size);
+extern int btrfs_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags);
+extern int btrfs_removexattr(struct dentry *dentry, const char *name);
+
+#endif /* __XATTR__ */
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
new file mode 100644
index 0000000..5b9f700
--- /dev/null
+++ b/fs/btrfs/zlib.c
@@ -0,0 +1,638 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on jffs2 zlib code:
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/zlib.h>
+#include <linux/zutil.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+
+/* Plan: call deflate() with avail_in == *sourcelen,
+ avail_out = *dstlen - 12 and flush == Z_FINISH.
+ If it doesn't manage to finish, call it again with
+ avail_in == 0 and avail_out set to the remaining 12
+ bytes for it to clean up.
+ Q: Is 12 bytes sufficient?
+*/
+#define STREAM_END_SPACE 12
+
+struct workspace {
+ z_stream inf_strm;
+ z_stream def_strm;
+ char *buf;
+ struct list_head list;
+};
+
+static LIST_HEAD(idle_workspace);
+static DEFINE_SPINLOCK(workspace_lock);
+static unsigned long num_workspace;
+static atomic_t alloc_workspace = ATOMIC_INIT(0);
+static DECLARE_WAIT_QUEUE_HEAD(workspace_wait);
+
+/*
+ * this finds an available zlib workspace or allocates a new one
+ * NULL or an ERR_PTR is returned if things go bad.
+ */
+static struct workspace *find_zlib_workspace(void)
+{
+ struct workspace *workspace;
+ int ret;
+ int cpus = num_online_cpus();
+
+again:
+ spin_lock(&workspace_lock);
+ if (!list_empty(&idle_workspace)) {
+ workspace = list_entry(idle_workspace.next, struct workspace,
+ list);
+ list_del(&workspace->list);
+ num_workspace--;
+ spin_unlock(&workspace_lock);
+ return workspace;
+
+ }
+ spin_unlock(&workspace_lock);
+ if (atomic_read(&alloc_workspace) > cpus) {
+ DEFINE_WAIT(wait);
+ prepare_to_wait(&workspace_wait, &wait, TASK_UNINTERRUPTIBLE);
+ if (atomic_read(&alloc_workspace) > cpus)
+ schedule();
+ finish_wait(&workspace_wait, &wait);
+ goto again;
+ }
+ atomic_inc(&alloc_workspace);
+ workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
+ if (!workspace) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ workspace->def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
+ if (!workspace->def_strm.workspace) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ workspace->inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
+ if (!workspace->inf_strm.workspace) {
+ ret = -ENOMEM;
+ goto fail_inflate;
+ }
+ workspace->buf = kmalloc(PAGE_CACHE_SIZE, GFP_NOFS);
+ if (!workspace->buf) {
+ ret = -ENOMEM;
+ goto fail_kmalloc;
+ }
+ return workspace;
+
+fail_kmalloc:
+ vfree(workspace->inf_strm.workspace);
+fail_inflate:
+ vfree(workspace->def_strm.workspace);
+fail:
+ kfree(workspace);
+ atomic_dec(&alloc_workspace);
+ wake_up(&workspace_wait);
+ return ERR_PTR(ret);
+}
+
+/*
+ * put a workspace struct back on the list or free it if we have enough
+ * idle ones sitting around
+ */
+static int free_workspace(struct workspace *workspace)
+{
+ spin_lock(&workspace_lock);
+ if (num_workspace < num_online_cpus()) {
+ list_add_tail(&workspace->list, &idle_workspace);
+ num_workspace++;
+ spin_unlock(&workspace_lock);
+ if (waitqueue_active(&workspace_wait))
+ wake_up(&workspace_wait);
+ return 0;
+ }
+ spin_unlock(&workspace_lock);
+ vfree(workspace->def_strm.workspace);
+ vfree(workspace->inf_strm.workspace);
+ kfree(workspace->buf);
+ kfree(workspace);
+
+ atomic_dec(&alloc_workspace);
+ if (waitqueue_active(&workspace_wait))
+ wake_up(&workspace_wait);
+ return 0;
+}
+
+/*
+ * cleanup function for module exit
+ */
+static void free_workspaces(void)
+{
+ struct workspace *workspace;
+ while(!list_empty(&idle_workspace)) {
+ workspace = list_entry(idle_workspace.next, struct workspace,
+ list);
+ list_del(&workspace->list);
+ vfree(workspace->def_strm.workspace);
+ vfree(workspace->inf_strm.workspace);
+ kfree(workspace->buf);
+ kfree(workspace);
+ atomic_dec(&alloc_workspace);
+ }
+}
+
+/*
+ * given an address space and start/len, compress the bytes.
+ *
+ * pages are allocated to hold the compressed result and stored
+ * in 'pages'
+ *
+ * out_pages is used to return the number of pages allocated. There
+ * may be pages allocated even if we return an error
+ *
+ * total_in is used to return the number of bytes actually read. It
+ * may be smaller then len if we had to exit early because we
+ * ran out of room in the pages array or because we cross the
+ * max_out threshold.
+ *
+ * total_out is used to return the total number of compressed bytes
+ *
+ * max_out tells us the max number of bytes that we're allowed to
+ * stuff into pages
+ */
+int btrfs_zlib_compress_pages(struct address_space *mapping,
+ u64 start, unsigned long len,
+ struct page **pages,
+ unsigned long nr_dest_pages,
+ unsigned long *out_pages,
+ unsigned long *total_in,
+ unsigned long *total_out,
+ unsigned long max_out)
+{
+ int ret;
+ struct workspace *workspace;
+ char *data_in;
+ char *cpage_out;
+ int nr_pages = 0;
+ struct page *in_page = NULL;
+ struct page *out_page = NULL;
+ int out_written = 0;
+ int in_read = 0;
+ unsigned long bytes_left;
+
+ *out_pages = 0;
+ *total_out = 0;
+ *total_in = 0;
+
+ workspace = find_zlib_workspace();
+ if (!workspace)
+ return -1;
+
+ if (Z_OK != zlib_deflateInit(&workspace->def_strm, 3)) {
+ printk(KERN_WARNING "deflateInit failed\n");
+ ret = -1;
+ goto out;
+ }
+
+ workspace->def_strm.total_in = 0;
+ workspace->def_strm.total_out = 0;
+
+ in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
+ data_in = kmap(in_page);
+
+ out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ cpage_out = kmap(out_page);
+ pages[0] = out_page;
+ nr_pages = 1;
+
+ workspace->def_strm.next_in = data_in;
+ workspace->def_strm.next_out = cpage_out;
+ workspace->def_strm.avail_out = PAGE_CACHE_SIZE;
+ workspace->def_strm.avail_in = min(len, PAGE_CACHE_SIZE);
+
+ out_written = 0;
+ in_read = 0;
+
+ while (workspace->def_strm.total_in < len) {
+ ret = zlib_deflate(&workspace->def_strm, Z_SYNC_FLUSH);
+ if (ret != Z_OK) {
+ printk(KERN_DEBUG "btrfs deflate in loop returned %d\n",
+ ret);
+ zlib_deflateEnd(&workspace->def_strm);
+ ret = -1;
+ goto out;
+ }
+
+ /* we're making it bigger, give up */
+ if (workspace->def_strm.total_in > 8192 &&
+ workspace->def_strm.total_in <
+ workspace->def_strm.total_out) {
+ ret = -1;
+ goto out;
+ }
+ /* we need another page for writing out. Test this
+ * before the total_in so we will pull in a new page for
+ * the stream end if required
+ */
+ if (workspace->def_strm.avail_out == 0) {
+ kunmap(out_page);
+ if (nr_pages == nr_dest_pages) {
+ out_page = NULL;
+ ret = -1;
+ goto out;
+ }
+ out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ cpage_out = kmap(out_page);
+ pages[nr_pages] = out_page;
+ nr_pages++;
+ workspace->def_strm.avail_out = PAGE_CACHE_SIZE;
+ workspace->def_strm.next_out = cpage_out;
+ }
+ /* we're all done */
+ if (workspace->def_strm.total_in >= len)
+ break;
+
+ /* we've read in a full page, get a new one */
+ if (workspace->def_strm.avail_in == 0) {
+ if (workspace->def_strm.total_out > max_out)
+ break;
+
+ bytes_left = len - workspace->def_strm.total_in;
+ kunmap(in_page);
+ page_cache_release(in_page);
+
+ start += PAGE_CACHE_SIZE;
+ in_page = find_get_page(mapping,
+ start >> PAGE_CACHE_SHIFT);
+ data_in = kmap(in_page);
+ workspace->def_strm.avail_in = min(bytes_left,
+ PAGE_CACHE_SIZE);
+ workspace->def_strm.next_in = data_in;
+ }
+ }
+ workspace->def_strm.avail_in = 0;
+ ret = zlib_deflate(&workspace->def_strm, Z_FINISH);
+ zlib_deflateEnd(&workspace->def_strm);
+
+ if (ret != Z_STREAM_END) {
+ ret = -1;
+ goto out;
+ }
+
+ if (workspace->def_strm.total_out >= workspace->def_strm.total_in) {
+ ret = -1;
+ goto out;
+ }
+
+ ret = 0;
+ *total_out = workspace->def_strm.total_out;
+ *total_in = workspace->def_strm.total_in;
+out:
+ *out_pages = nr_pages;
+ if (out_page)
+ kunmap(out_page);
+
+ if (in_page) {
+ kunmap(in_page);
+ page_cache_release(in_page);
+ }
+ free_workspace(workspace);
+ return ret;
+}
+
+/*
+ * pages_in is an array of pages with compressed data.
+ *
+ * disk_start is the starting logical offset of this array in the file
+ *
+ * bvec is a bio_vec of pages from the file that we want to decompress into
+ *
+ * vcnt is the count of pages in the biovec
+ *
+ * srclen is the number of bytes in pages_in
+ *
+ * The basic idea is that we have a bio that was created by readpages.
+ * The pages in the bio are for the uncompressed data, and they may not
+ * be contiguous. They all correspond to the range of bytes covered by
+ * the compressed extent.
+ */
+int btrfs_zlib_decompress_biovec(struct page **pages_in,
+ u64 disk_start,
+ struct bio_vec *bvec,
+ int vcnt,
+ size_t srclen)
+{
+ int ret = 0;
+ int wbits = MAX_WBITS;
+ struct workspace *workspace;
+ char *data_in;
+ size_t total_out = 0;
+ unsigned long page_bytes_left;
+ unsigned long page_in_index = 0;
+ unsigned long page_out_index = 0;
+ struct page *page_out;
+ unsigned long total_pages_in = (srclen + PAGE_CACHE_SIZE - 1) /
+ PAGE_CACHE_SIZE;
+ unsigned long buf_start;
+ unsigned long buf_offset;
+ unsigned long bytes;
+ unsigned long working_bytes;
+ unsigned long pg_offset;
+ unsigned long start_byte;
+ unsigned long current_buf_start;
+ char *kaddr;
+
+ workspace = find_zlib_workspace();
+ if (!workspace)
+ return -ENOMEM;
+
+ data_in = kmap(pages_in[page_in_index]);
+ workspace->inf_strm.next_in = data_in;
+ workspace->inf_strm.avail_in = min_t(size_t, srclen, PAGE_CACHE_SIZE);
+ workspace->inf_strm.total_in = 0;
+
+ workspace->inf_strm.total_out = 0;
+ workspace->inf_strm.next_out = workspace->buf;
+ workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
+ page_out = bvec[page_out_index].bv_page;
+ page_bytes_left = PAGE_CACHE_SIZE;
+ pg_offset = 0;
+
+ /* If it's deflate, and it's got no preset dictionary, then
+ we can tell zlib to skip the adler32 check. */
+ if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
+ ((data_in[0] & 0x0f) == Z_DEFLATED) &&
+ !(((data_in[0]<<8) + data_in[1]) % 31)) {
+
+ wbits = -((data_in[0] >> 4) + 8);
+ workspace->inf_strm.next_in += 2;
+ workspace->inf_strm.avail_in -= 2;
+ }
+
+ if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) {
+ printk(KERN_WARNING "inflateInit failed\n");
+ ret = -1;
+ goto out;
+ }
+ while(workspace->inf_strm.total_in < srclen) {
+ ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH);
+ if (ret != Z_OK && ret != Z_STREAM_END) {
+ break;
+ }
+
+ /*
+ * buf start is the byte offset we're of the start of
+ * our workspace buffer
+ */
+ buf_start = total_out;
+
+ /* total_out is the last byte of the workspace buffer */
+ total_out = workspace->inf_strm.total_out;
+
+ working_bytes = total_out - buf_start;
+
+ /*
+ * start byte is the first byte of the page we're currently
+ * copying into relative to the start of the compressed data.
+ */
+ start_byte = page_offset(page_out) - disk_start;
+
+ if (working_bytes == 0) {
+ /* we didn't make progress in this inflate
+ * call, we're done
+ */
+ if (ret != Z_STREAM_END) {
+ ret = -1;
+ }
+ break;
+ }
+
+ /* we haven't yet hit data corresponding to this page */
+ if (total_out <= start_byte) {
+ goto next;
+ }
+
+ /*
+ * the start of the data we care about is offset into
+ * the middle of our working buffer
+ */
+ if (total_out > start_byte && buf_start < start_byte) {
+ buf_offset = start_byte - buf_start;
+ working_bytes -= buf_offset;
+ } else {
+ buf_offset = 0;
+ }
+ current_buf_start = buf_start;
+
+ /* copy bytes from the working buffer into the pages */
+ while(working_bytes > 0) {
+ bytes = min(PAGE_CACHE_SIZE - pg_offset,
+ PAGE_CACHE_SIZE - buf_offset);
+ bytes = min(bytes, working_bytes);
+ kaddr = kmap_atomic(page_out, KM_USER0);
+ memcpy(kaddr + pg_offset, workspace->buf + buf_offset,
+ bytes);
+ kunmap_atomic(kaddr, KM_USER0);
+ flush_dcache_page(page_out);
+
+ pg_offset += bytes;
+ page_bytes_left -= bytes;
+ buf_offset += bytes;
+ working_bytes -= bytes;
+ current_buf_start += bytes;
+
+ /* check if we need to pick another page */
+ if (page_bytes_left == 0) {
+ page_out_index++;
+ if (page_out_index >= vcnt) {
+ ret = 0;
+ goto done;
+ }
+ page_out = bvec[page_out_index].bv_page;
+ pg_offset = 0;
+ page_bytes_left = PAGE_CACHE_SIZE;
+ start_byte = page_offset(page_out) - disk_start;
+
+ /*
+ * make sure our new page is covered by this
+ * working buffer
+ */
+ if (total_out <= start_byte) {
+ goto next;
+ }
+
+ /* the next page in the biovec might not
+ * be adjacent to the last page, but it
+ * might still be found inside this working
+ * buffer. bump our offset pointer
+ */
+ if (total_out > start_byte &&
+ current_buf_start < start_byte) {
+ buf_offset = start_byte - buf_start;
+ working_bytes = total_out - start_byte;
+ current_buf_start = buf_start +
+ buf_offset;
+ }
+ }
+ }
+next:
+ workspace->inf_strm.next_out = workspace->buf;
+ workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
+
+ if (workspace->inf_strm.avail_in == 0) {
+ unsigned long tmp;
+ kunmap(pages_in[page_in_index]);
+ page_in_index++;
+ if (page_in_index >= total_pages_in) {
+ data_in = NULL;
+ break;
+ }
+ data_in = kmap(pages_in[page_in_index]);
+ workspace->inf_strm.next_in = data_in;
+ tmp = srclen - workspace->inf_strm.total_in;
+ workspace->inf_strm.avail_in = min(tmp,
+ PAGE_CACHE_SIZE);
+ }
+ }
+ if (ret != Z_STREAM_END) {
+ ret = -1;
+ } else {
+ ret = 0;
+ }
+done:
+ zlib_inflateEnd(&workspace->inf_strm);
+ if (data_in)
+ kunmap(pages_in[page_in_index]);
+out:
+ free_workspace(workspace);
+ return ret;
+}
+
+/*
+ * a less complex decompression routine. Our compressed data fits in a
+ * single page, and we want to read a single page out of it.
+ * start_byte tells us the offset into the compressed data we're interested in
+ */
+int btrfs_zlib_decompress(unsigned char *data_in,
+ struct page *dest_page,
+ unsigned long start_byte,
+ size_t srclen, size_t destlen)
+{
+ int ret = 0;
+ int wbits = MAX_WBITS;
+ struct workspace *workspace;
+ unsigned long bytes_left = destlen;
+ unsigned long total_out = 0;
+ char *kaddr;
+
+ if (destlen > PAGE_CACHE_SIZE)
+ return -ENOMEM;
+
+ workspace = find_zlib_workspace();
+ if (!workspace)
+ return -ENOMEM;
+
+ workspace->inf_strm.next_in = data_in;
+ workspace->inf_strm.avail_in = srclen;
+ workspace->inf_strm.total_in = 0;
+
+ workspace->inf_strm.next_out = workspace->buf;
+ workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
+ workspace->inf_strm.total_out = 0;
+ /* If it's deflate, and it's got no preset dictionary, then
+ we can tell zlib to skip the adler32 check. */
+ if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
+ ((data_in[0] & 0x0f) == Z_DEFLATED) &&
+ !(((data_in[0]<<8) + data_in[1]) % 31)) {
+
+ wbits = -((data_in[0] >> 4) + 8);
+ workspace->inf_strm.next_in += 2;
+ workspace->inf_strm.avail_in -= 2;
+ }
+
+ if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) {
+ printk(KERN_WARNING "inflateInit failed\n");
+ ret = -1;
+ goto out;
+ }
+
+ while(bytes_left > 0) {
+ unsigned long buf_start;
+ unsigned long buf_offset;
+ unsigned long bytes;
+ unsigned long pg_offset = 0;
+
+ ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH);
+ if (ret != Z_OK && ret != Z_STREAM_END) {
+ break;
+ }
+
+ buf_start = total_out;
+ total_out = workspace->inf_strm.total_out;
+
+ if (total_out == buf_start) {
+ ret = -1;
+ break;
+ }
+
+ if (total_out <= start_byte) {
+ goto next;
+ }
+
+ if (total_out > start_byte && buf_start < start_byte) {
+ buf_offset = start_byte - buf_start;
+ } else {
+ buf_offset = 0;
+ }
+
+ bytes = min(PAGE_CACHE_SIZE - pg_offset,
+ PAGE_CACHE_SIZE - buf_offset);
+ bytes = min(bytes, bytes_left);
+
+ kaddr = kmap_atomic(dest_page, KM_USER0);
+ memcpy(kaddr + pg_offset, workspace->buf + buf_offset, bytes);
+ kunmap_atomic(kaddr, KM_USER0);
+
+ pg_offset += bytes;
+ bytes_left -= bytes;
+next:
+ workspace->inf_strm.next_out = workspace->buf;
+ workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
+ }
+ if (ret != Z_STREAM_END && bytes_left != 0) {
+ ret = -1;
+ } else {
+ ret = 0;
+ }
+ zlib_inflateEnd(&workspace->inf_strm);
+out:
+ free_workspace(workspace);
+ return ret;
+}
+
+void btrfs_zlib_exit(void)
+{
+ free_workspaces();
+}