ext4: find old entry again if failed to rename whiteout

If we failed to add new entry on rename whiteout, we cannot reset the
old->de entry directly, because the old->de could have moved from under
us during make indexed dir. So find the old entry again before reset is
needed, otherwise it may corrupt the filesystem as below.

  /dev/sda: Entry '00000001' in ??? (12) has deleted/unused inode 15. CLEARED.
  /dev/sda: Unattached inode 75
  /dev/sda: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.

Fixes: 6b4b8e6b4a ("ext4: fix bug for rename with RENAME_WHITEOUT")
Cc: stable@vger.kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
zhangyi (F) 2021-03-03 21:17:02 +08:00 committed by Theodore Ts'o
parent f053cf7aa6
commit b7ff91fd03

View File

@ -3613,6 +3613,31 @@ static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
return retval;
}
static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
unsigned ino, unsigned file_type)
{
struct ext4_renament old = *ent;
int retval = 0;
/*
* old->de could have moved from under us during make indexed dir,
* so the old->de may no longer valid and need to find it again
* before reset old inode info.
*/
old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
if (IS_ERR(old.bh))
retval = PTR_ERR(old.bh);
if (!old.bh)
retval = -ENOENT;
if (retval) {
ext4_std_error(old.dir->i_sb, retval);
return;
}
ext4_setent(handle, &old, ino, file_type);
brelse(old.bh);
}
static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
const struct qstr *d_name)
{
@ -3937,8 +3962,8 @@ static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
end_rename:
if (whiteout) {
if (retval) {
ext4_setent(handle, &old,
old.inode->i_ino, old_file_type);
ext4_resetent(handle, &old,
old.inode->i_ino, old_file_type);
drop_nlink(whiteout);
}
unlock_new_inode(whiteout);