@@ -2333,7 +2333,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *old_inode, *new_inode;
struct buffer_head *old_bh, *new_bh, *dir_bh;
struct ext4_dir_entry_2 *old_de, *new_de;
- int retval, force_da_alloc = 0;
+ int retval;
dquot_initialize(old_dir);
dquot_initialize(new_dir);
@@ -2344,14 +2344,6 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
* in separate transaction */
if (new_dentry->d_inode)
dquot_initialize(new_dentry->d_inode);
- handle = ext4_journal_start(old_dir, 2 *
- EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
- EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
- if (IS_ERR(handle))
- return PTR_ERR(handle);
-
- if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
- ext4_handle_sync(handle);
old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
/*
@@ -2363,7 +2355,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
old_inode = old_dentry->d_inode;
retval = -ENOENT;
if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
- goto end_rename;
+ goto out_release;
new_inode = new_dentry->d_inode;
new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
@@ -2373,6 +2365,19 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
new_bh = NULL;
}
}
+
+ if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC) && new_inode)
+ ext4_alloc_da_blocks(old_inode);
+
+ handle = ext4_journal_start(old_dir, 2 *
+ EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+ ext4_handle_sync(handle);
+
if (S_ISDIR(old_inode->i_mode)) {
if (new_inode) {
retval = -ENOTEMPTY;
@@ -2476,18 +2481,15 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
ext4_mark_inode_dirty(handle, new_inode);
if (!new_inode->i_nlink)
ext4_orphan_add(handle, new_inode);
- if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
- force_da_alloc = 1;
}
retval = 0;
end_rename:
+ ext4_journal_stop(handle);
+out_release:
brelse(dir_bh);
brelse(old_bh);
brelse(new_bh);
- ext4_journal_stop(handle);
- if (retval == 0 && force_da_alloc)
- ext4_alloc_da_blocks(old_inode);
return retval;
}
Ext4 already performs block allocation on rename, but it does it after rename was complete, so race window is much tighter but still exist. In order to guarantee atomic behavior let's force block allocation before actual rename. This rearrangement should not affect IO performance. - Code cleanup: It is possible to move some checks out of transaction which theoretically may result in better performance. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> --- fs/ext4/namei.c | 32 +++++++++++++++++--------------- 1 files changed, 17 insertions(+), 15 deletions(-)