[PATCH 5.11 038/152] ext4: do not iput inode under running transaction in ext4_rename()

Greg Kroah-Hartman
2021-04-05T09:16:39Z

From: zhangyi (F) <yi.zhang@huawei.com>

[ Upstream commit 5dccdc5a1916d4266edd251f20bbbb113a5c495f ]

In ext4_rename(), when RENAME_WHITEOUT failed to add new entry into
directory, it ends up dropping new created whiteout inode under the
running transaction. After commit <9b88f9fb0d2> ("ext4: Do not iput inode
under running transaction"), we follow the assumptions that evict() does
not get called from a transaction context but in ext4_rename() it breaks
this suggestion. Although it's not a real problem, better to obey it, so
this patch add inode to orphan list and stop transaction before final
iput().

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext4/namei.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 078f26f4b56e..9cc9e6c1d582 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3785,14 +3785,14 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
*/
retval = -ENOENT;
if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
- goto end_rename;
+ goto release_bh;

new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
&new.de, &new.inlined);
if (IS_ERR(new.bh)) {
retval = PTR_ERR(new.bh);
new.bh = NULL;
- goto end_rename;
+ goto release_bh;
}
if (new.bh) {
if (!new.inode) {
@@ -3809,15 +3809,13 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
- handle = NULL;
- goto end_rename;
+ goto release_bh;
}
} else {
whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
if (IS_ERR(whiteout)) {
retval = PTR_ERR(whiteout);
- whiteout = NULL;
- goto end_rename;
+ goto release_bh;
}
}

@@ -3954,16 +3952,18 @@ end_rename:
ext4_resetent(handle, &old,
old.inode->i_ino, old_file_type);
drop_nlink(whiteout);
+ ext4_orphan_add(handle, whiteout);
}
unlock_new_inode(whiteout);
+ ext4_journal_stop(handle);
iput(whiteout);
-
+ } else {
+ ext4_journal_stop(handle);
}
+release_bh:
brelse(old.dir_bh);
brelse(old.bh);
brelse(new.bh);
- if (handle)
- ext4_journal_stop(handle);
return retval;
}

--
2.30.1