Btrfs: early fsync support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/TODO b/fs/btrfs/TODO
index 8d7e5a3..5ff2cef 100644
--- a/fs/btrfs/TODO
+++ b/fs/btrfs/TODO
@@ -7,6 +7,7 @@
* Get rid of struct ctree_path, limiting tree levels held at one time
* Add generation number to key pointer in nodes
* Add parent pointer back to extent map.
+* Implement real list of pending transactions
* Release
* Do real tree locking
* Add extent mirroring (backup copies of blocks)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d628a3b..047a847 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -256,6 +256,7 @@
struct inode *btree_inode;
struct mutex trans_mutex;
struct mutex fs_mutex;
+ struct list_head trans_list;
struct crypto_hash *hash_tfm;
spinlock_t hash_lock;
struct kobject kobj;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 11e17a2..b666c35 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -528,6 +528,7 @@
init_bit_radix(&fs_info->pending_del_radix);
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
INIT_RADIX_TREE(&fs_info->dev_radix, GFP_NOFS);
+ INIT_LIST_HEAD(&fs_info->trans_list);
sb_set_blocksize(sb, 4096);
fs_info->running_transaction = NULL;
fs_info->tree_root = tree_root;
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 72be983..a42943b 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -100,7 +100,6 @@
BUG_ON(refs == 0);
if (refs == 1) {
ret = btrfs_del_item(trans, root, path);
-printk("deleting root %Lu %Lu %u\n", key->objectid, key->offset, key->flags);
} else {
btrfs_set_root_refs(ri, refs - 1);
printk("ref now %u root %Lu %Lu %u\n", refs -1, key->objectid, key->offset, key->flags);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index dff2db0..f99c764 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -11,6 +11,7 @@
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
+#include <linux/statfs.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
@@ -932,6 +933,26 @@
return err;
}
+static 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;
+ struct btrfs_trans_handle *trans;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ if (!trans) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = btrfs_commit_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+out:
+ return ret > 0 ? EIO : ret;
+}
+
static int btrfs_sync_fs(struct super_block *sb, int wait)
{
struct btrfs_trans_handle *trans;
@@ -2353,6 +2374,19 @@
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->disk_super;
+
+ buf->f_namelen = BTRFS_NAME_LEN;
+ buf->f_blocks = btrfs_super_total_blocks(disk_super);
+ buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super);
+ buf->f_bavail = buf->f_bfree;
+ buf->f_bsize = dentry->d_sb->s_blocksize;
+ buf->f_type = BTRFS_SUPER_MAGIC;
+ return 0;
+}
static struct file_system_type btrfs_fs_type = {
.owner = THIS_MODULE,
.name = "btrfs",
@@ -2362,7 +2396,6 @@
};
static struct super_operations btrfs_super_ops = {
- .statfs = simple_statfs,
.delete_inode = btrfs_delete_inode,
.put_super = btrfs_put_super,
.read_inode = btrfs_read_locked_inode,
@@ -2371,6 +2404,7 @@
.write_inode = btrfs_write_inode,
.alloc_inode = btrfs_alloc_inode,
.destroy_inode = btrfs_destroy_inode,
+ .statfs = btrfs_statfs,
};
static struct inode_operations btrfs_dir_inode_operations = {
@@ -2413,6 +2447,7 @@
.mmap = generic_file_mmap,
.open = generic_file_open,
.ioctl = btrfs_ioctl,
+ .fsync = btrfs_sync_file,
};
static int __init init_btrfs_fs(void)
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8740752..078cb9c 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -19,6 +19,7 @@
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);
}
@@ -43,6 +44,7 @@
cur_trans->in_commit = 0;
cur_trans->use_count = 1;
cur_trans->commit_done = 0;
+ list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
}
cur_trans->num_writers++;
return 0;
@@ -236,6 +238,7 @@
{
int ret = 0;
struct btrfs_transaction *cur_trans;
+ struct btrfs_transaction *prev_trans = NULL;
struct list_head dirty_fs_roots;
DEFINE_WAIT(wait);
@@ -272,13 +275,29 @@
BUG_ON(ret);
cur_trans = root->fs_info->running_transaction;
root->fs_info->running_transaction = NULL;
- btrfs_set_super_generation(root->fs_info->disk_super,
- root->fs_info->generation + 1);
+ 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 = NULL;
+ else
+ prev_trans->use_count++;
+ }
mutex_unlock(&root->fs_info->trans_mutex);
+ mutex_unlock(&root->fs_info->fs_mutex);
ret = btrfs_write_and_wait_transaction(trans, root);
+ if (prev_trans) {
+ mutex_lock(&root->fs_info->trans_mutex);
+ wait_for_commit(root, prev_trans);
+ put_transaction(prev_trans);
+ mutex_unlock(&root->fs_info->trans_mutex);
+ }
+ btrfs_set_super_generation(root->fs_info->disk_super,
+ cur_trans->transid);
BUG_ON(ret);
-
write_ctree_super(trans, root);
+
+ mutex_lock(&root->fs_info->fs_mutex);
btrfs_finish_extent_commit(trans, root);
mutex_lock(&root->fs_info->trans_mutex);
cur_trans->commit_done = 1;
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 4f1496a..3cc2990 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -8,6 +8,7 @@
int use_count;
int commit_done;
int magic;
+ struct list_head list;
wait_queue_head_t writer_wait;
wait_queue_head_t commit_wait;
};