Btrfs: transaction rework
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 1a0fb74..be7d74c 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -3,7 +3,7 @@
obj-m := btrfs.o
btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
- hash.o file-item.o inode-item.o inode-map.o disk-io.o
+ hash.o file-item.o inode-item.o inode-map.o disk-io.o transaction.o
#btrfs-y := ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
# root-tree.o dir-item.o hash.o file-item.o inode-item.o \
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7748eec..4c19a3f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -5,6 +5,7 @@
#include <linux/fs.h>
struct btrfs_trans_handle;
+struct btrfs_transaction;
#define BTRFS_MAGIC "_BtRfS_M"
@@ -224,10 +225,11 @@
u64 last_inode_alloc;
u64 last_inode_alloc_dirid;
u64 generation;
- struct btrfs_trans_handle *running_transaction;
+ struct btrfs_transaction *running_transaction;
struct btrfs_super_block *disk_super;
struct buffer_head *sb_buffer;
struct super_block *sb;
+ struct mutex trans_mutex;
};
/*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index df2061a..9cacca0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -50,89 +50,6 @@
return 0;
}
-int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct buffer_head *buf)
-{
- mark_buffer_dirty(buf);
- return 0;
-}
-
-static int __commit_transaction(struct btrfs_trans_handle *trans, struct
- btrfs_root *root)
-{
- filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
- return 0;
-}
-
-static int commit_tree_roots(struct btrfs_trans_handle *trans,
- struct btrfs_fs_info *fs_info)
-{
- int ret;
- u64 old_extent_block;
- struct btrfs_root *tree_root = fs_info->tree_root;
- struct btrfs_root *extent_root = fs_info->extent_root;
- struct btrfs_root *inode_root = fs_info->inode_root;
-
- btrfs_set_root_blocknr(&inode_root->root_item,
- inode_root->node->b_blocknr);
- ret = btrfs_update_root(trans, tree_root,
- &inode_root->root_key,
- &inode_root->root_item);
- BUG_ON(ret);
- while(1) {
- old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
- if (old_extent_block == extent_root->node->b_blocknr)
- break;
- btrfs_set_root_blocknr(&extent_root->root_item,
- extent_root->node->b_blocknr);
- ret = btrfs_update_root(trans, tree_root,
- &extent_root->root_key,
- &extent_root->root_item);
- BUG_ON(ret);
- }
- return 0;
-}
-
-int btrfs_commit_transaction(struct btrfs_trans_handle *trans, struct
- btrfs_root *root, struct btrfs_super_block *s)
-{
- int ret = 0;
- struct buffer_head *snap = root->commit_root;
- struct btrfs_key snap_key;
-
- if (root->commit_root == root->node)
- return 0;
-
- memcpy(&snap_key, &root->root_key, sizeof(snap_key));
- root->root_key.offset++;
-
- btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr);
- ret = btrfs_insert_root(trans, root->fs_info->tree_root,
- &root->root_key, &root->root_item);
- BUG_ON(ret);
-
- ret = commit_tree_roots(trans, root->fs_info);
- BUG_ON(ret);
-
- ret = __commit_transaction(trans, root);
- BUG_ON(ret);
-
- write_ctree_super(trans, root, s);
- btrfs_finish_extent_commit(trans, root->fs_info->extent_root);
- btrfs_finish_extent_commit(trans, root->fs_info->tree_root);
-
- root->commit_root = root->node;
- get_bh(root->node);
- ret = btrfs_drop_snapshot(trans, root, snap);
- BUG_ON(ret);
-
- ret = btrfs_del_root(trans, root->fs_info->tree_root, &snap_key);
- BUG_ON(ret);
- root->fs_info->generation = root->root_key.offset + 1;
-
- return ret;
-}
-
static int __setup_root(struct btrfs_super_block *super,
struct btrfs_root *root,
struct btrfs_fs_info *fs_info,
@@ -197,6 +114,7 @@
fs_info->disk_super = disk_super;
fs_info->sb_buffer = sb_buffer;
fs_info->sb = sb;
+ mutex_init(&fs_info->trans_mutex);
memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
@@ -225,7 +143,7 @@
}
int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_super_block *s)
+ *root)
{
return 0;
#if 0
@@ -242,34 +160,19 @@
#endif
}
-static int drop_cache(struct btrfs_root *root)
-{
- return 0;
-#if 0
- while(!list_empty(&root->fs_info->cache)) {
- struct buffer_head *b = list_entry(root->fs_info->cache.next,
- struct buffer_head,
- cache);
- list_del_init(&b->cache);
- btrfs_block_release(root, b);
- }
- return 0;
-#endif
-}
-
int close_ctree(struct btrfs_root *root)
{
int ret;
struct btrfs_trans_handle *trans;
- trans = root->fs_info->running_transaction;
- btrfs_commit_transaction(trans, root, root->fs_info->disk_super);
- ret = commit_tree_roots(trans, root->fs_info);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_commit_transaction(trans, root);
+ /* 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 = __commit_transaction(trans, root);
- BUG_ON(ret);
- write_ctree_super(trans, root, root->fs_info->disk_super);
- drop_cache(root);
+ write_ctree_super(NULL, root);
if (root->node)
btrfs_block_release(root, root->node);
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 7f4bb72..099f7ee 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -28,14 +28,14 @@
struct buffer_head *buf);
int clean_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct buffer_head *buf);
-int btrfs_commit_transaction(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_super_block *s);
+int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
struct btrfs_root *open_ctree(struct super_block *sb,
struct buffer_head *sb_buffer,
struct btrfs_super_block *disk_super);
int close_ctree(struct btrfs_root *root);
void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf);
-int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct btrfs_super_block *s);
+int write_ctree_super(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
int mkfs(int fd, u64 num_blocks, u32 blocksize);
#endif
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index ccc056a..6204308 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -141,7 +141,6 @@
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
int ret;
-printk("read locked inode %lu\n", inode->i_ino);
btrfs_init_path(&path);
ret = btrfs_lookup_inode(NULL, root, &path, inode->i_ino, 0);
if (ret) {
@@ -152,7 +151,6 @@
path.slots[0],
struct btrfs_inode_item);
-printk("found locked inode %lu\n", inode->i_ino);
inode->i_mode = btrfs_inode_mode(inode_item);
inode->i_nlink = btrfs_inode_nlink(inode_item);
inode->i_uid = btrfs_inode_uid(inode_item);
@@ -166,7 +164,6 @@
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
inode->i_blocks = btrfs_inode_nblocks(inode_item);
inode->i_generation = btrfs_inode_generation(inode_item);
-printk("about to release\n");
btrfs_release_path(root, &path);
switch (inode->i_mode & S_IFMT) {
#if 0
@@ -176,19 +173,15 @@
break;
#endif
case S_IFREG:
-printk("inode %lu now a file\n", inode->i_ino);
break;
case S_IFDIR:
-printk("inode %lu now a directory\n", inode->i_ino);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
break;
case S_IFLNK:
-printk("inode %lu now a link\n", inode->i_ino);
// inode->i_op = &page_symlink_inode_operations;
break;
}
-printk("returning!\n");
return;
}
@@ -232,7 +225,6 @@
return ERR_PTR(ret);
inode = NULL;
if (ino) {
-printk("lookup on %.*s returns %lu\n", dentry->d_name.len, dentry->d_name.name, ino);
inode = iget(dir->i_sb, ino);
if (!inode)
return ERR_PTR(-EACCES);
@@ -257,7 +249,6 @@
int over;
key.objectid = inode->i_ino;
-printk("readdir on dir %Lu pos %Lu\n", key.objectid, filp->f_pos);
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
key.offset = filp->f_pos;
@@ -266,15 +257,12 @@
if (ret < 0) {
goto err;
}
-printk("first ret %d\n", ret);
advance = filp->f_pos > 0 && ret != 0;
while(1) {
leaf = btrfs_buffer_leaf(path.nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path.slots[0];
-printk("leaf %Lu nritems %lu slot %d\n", path.nodes[0]->b_blocknr, nritems, slot);
if (advance) {
-printk("advancing!\n");
if (slot == nritems -1) {
ret = btrfs_next_leaf(root, &path);
if (ret)
@@ -282,7 +270,6 @@
leaf = btrfs_buffer_leaf(path.nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path.slots[0];
-printk("2leaf %Lu nritems %lu slot %d\n", path.nodes[0]->b_blocknr, nritems, slot);
} else {
slot++;
path.slots[0]++;
@@ -290,15 +277,11 @@
}
advance = 1;
item = leaf->items + slot;
-printk("item key %Lu %u %Lu\n", btrfs_disk_key_objectid(&item->key),
- btrfs_disk_key_flags(&item->key), btrfs_disk_key_offset(&item->key));
if (btrfs_disk_key_objectid(&item->key) != key.objectid)
break;
if (btrfs_disk_key_type(&item->key) != BTRFS_DIR_ITEM_KEY)
continue;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
-printk("filldir name %.*s, objectid %Lu\n", btrfs_dir_name_len(di),
- (const char *)(di + 1), btrfs_dir_objectid(di));
over = filldir(dirent, (const char *)(di + 1),
btrfs_dir_name_len(di),
btrfs_disk_key_offset(&item->key),
@@ -307,7 +290,6 @@
break;
filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
}
-printk("filldir all done\n");
ret = 0;
err:
btrfs_release_path(root, &path);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
new file mode 100644
index 0000000..8dc1c17
--- /dev/null
+++ b/fs/btrfs/transaction.c
@@ -0,0 +1,199 @@
+#include <linux/module.h>
+#include <linux/fs.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+
+static void put_transaction(struct btrfs_transaction *transaction)
+{
+ transaction->use_count--;
+ if (transaction->use_count == 0)
+ kfree(transaction);
+}
+
+static int join_transaction(struct btrfs_root *root)
+{
+ struct btrfs_transaction *cur_trans;
+ cur_trans = root->fs_info->running_transaction;
+ if (!cur_trans) {
+ cur_trans = kmalloc(sizeof(*cur_trans), GFP_NOFS);
+ BUG_ON(!cur_trans);
+ root->fs_info->running_transaction = cur_trans;
+ cur_trans->num_writers = 0;
+ cur_trans->transid = root->root_key.offset + 1;
+ init_waitqueue_head(&cur_trans->writer_wait);
+ init_waitqueue_head(&cur_trans->commit_wait);
+ cur_trans->in_commit = 0;
+ cur_trans->use_count = 0;
+ cur_trans->commit_done = 0;
+ }
+ cur_trans->num_writers++;
+ return 0;
+}
+
+struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
+ int num_blocks)
+{
+ struct btrfs_trans_handle *h = kmalloc(sizeof(*h), GFP_NOFS);
+ int ret;
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ ret = join_transaction(root);
+ BUG_ON(ret);
+ h->transid = root->fs_info->running_transaction->transid;
+ h->transaction = root->fs_info->running_transaction;
+ h->blocks_reserved = num_blocks;
+ h->blocks_used = 0;
+ root->fs_info->running_transaction->use_count++;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ return h;
+}
+
+int btrfs_end_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_transaction *cur_trans;
+ mutex_lock(&root->fs_info->trans_mutex);
+ cur_trans = root->fs_info->running_transaction;
+ WARN_ON(cur_trans->num_writers <= 1);
+ if (waitqueue_active(&cur_trans->writer_wait))
+ wake_up(&cur_trans->writer_wait);
+ cur_trans->num_writers--;
+ put_transaction(cur_trans);
+ mutex_unlock(&root->fs_info->trans_mutex);
+ kfree(trans);
+ return 0;
+}
+
+
+int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
+ return 0;
+}
+
+int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ int ret;
+ u64 old_extent_block;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ struct btrfs_root *extent_root = fs_info->extent_root;
+ struct btrfs_root *inode_root = fs_info->inode_root;
+
+ btrfs_set_root_blocknr(&inode_root->root_item,
+ inode_root->node->b_blocknr);
+ ret = btrfs_update_root(trans, tree_root,
+ &inode_root->root_key,
+ &inode_root->root_item);
+ BUG_ON(ret);
+ while(1) {
+ old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
+ if (old_extent_block == extent_root->node->b_blocknr)
+ break;
+ btrfs_set_root_blocknr(&extent_root->root_item,
+ extent_root->node->b_blocknr);
+ ret = btrfs_update_root(trans, tree_root,
+ &extent_root->root_key,
+ &extent_root->root_item);
+ BUG_ON(ret);
+ }
+ return 0;
+}
+
+static int wait_for_commit(struct btrfs_root *root,
+ struct btrfs_transaction *commit)
+{
+ DEFINE_WAIT(wait);
+ commit->use_count++;
+ 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);
+ }
+ finish_wait(&commit->commit_wait, &wait);
+ return 0;
+}
+
+int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ int ret = 0;
+ struct buffer_head *snap = root->commit_root;
+ struct btrfs_key snap_key;
+ struct btrfs_transaction *cur_trans;
+ DEFINE_WAIT(wait);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (trans->transaction->in_commit) {
+ cur_trans = trans->transaction;
+ trans->transaction->use_count++;
+ btrfs_end_transaction(trans, root);
+ ret = wait_for_commit(root, cur_trans);
+ BUG_ON(ret);
+ put_transaction(cur_trans);
+ mutex_unlock(&root->fs_info->trans_mutex);
+ return 0;
+ }
+ while (trans->transaction->num_writers > 1) {
+ prepare_to_wait(&trans->transaction->writer_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (trans->transaction->num_writers <= 1)
+ break;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ schedule();
+ mutex_lock(&root->fs_info->trans_mutex);
+ }
+ finish_wait(&trans->transaction->writer_wait, &wait);
+
+ cur_trans = root->fs_info->running_transaction;
+ root->fs_info->running_transaction = NULL;
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ memcpy(&snap_key, &root->root_key, sizeof(snap_key));
+ root->root_key.offset++;
+
+ if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) {
+ btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr);
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root,
+ &root->root_key, &root->root_item);
+ BUG_ON(ret);
+ }
+
+ ret = btrfs_commit_tree_roots(trans, root);
+ BUG_ON(ret);
+
+ ret = btrfs_write_and_wait_transaction(trans, root);
+ BUG_ON(ret);
+
+ write_ctree_super(trans, root);
+ btrfs_finish_extent_commit(trans, root->fs_info->extent_root);
+ btrfs_finish_extent_commit(trans, root->fs_info->tree_root);
+ put_transaction(cur_trans);
+ kfree(trans);
+
+ if (root->node != root->commit_root) {
+ trans = btrfs_start_transaction(root, 1);
+ root->commit_root = root->node;
+ get_bh(root->node);
+ ret = btrfs_drop_snapshot(trans, root, snap);
+ BUG_ON(ret);
+
+ ret = btrfs_del_root(trans, root->fs_info->tree_root,
+ &snap_key);
+ BUG_ON(ret);
+ root->fs_info->generation = root->root_key.offset + 1;
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ }
+
+ return ret;
+}
+
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 9ab27b7..7e6c08a 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -1,27 +1,30 @@
#ifndef __TRANSACTION__
#define __TRANSACTION__
+struct btrfs_transaction {
+ u64 transid;
+ unsigned long num_writers;
+ int in_commit;
+ int use_count;
+ int commit_done;
+ wait_queue_head_t writer_wait;
+ wait_queue_head_t commit_wait;
+};
+
struct btrfs_trans_handle {
u64 transid;
unsigned long blocks_reserved;
unsigned long blocks_used;
+ struct btrfs_transaction *transaction;
};
-static inline struct btrfs_trans_handle *
-btrfs_start_transaction(struct btrfs_root *root, int num_blocks)
-{
- struct btrfs_trans_handle *h = kmalloc(sizeof(*h), GFP_NOFS);
- h->transid = root->root_key.offset;
- h->blocks_reserved = num_blocks;
- h->blocks_used = 0;
- return h;
-}
-static inline void btrfs_free_transaction(struct btrfs_root *root,
- struct btrfs_trans_handle *handle)
-{
- memset(handle, 0, sizeof(*handle));
- kfree(handle);
-}
-
+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);
+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);
#endif