CIFS: Fix directory rename error

CIFS servers process nlink counts differently for files and directories.
In cifs_rename() if we the request fails on the existing target, we
try to remove it through cifs_unlink() but this is not what we want
to do for directories. As the result the following sequence of commands

mkdir {1,2}; mv -T 1 2; rmdir {1,2}; mkdir {1,2}; echo foo > 2/bar

and XFS test generic/023 fail with -ENOENT error. That's why the second
mkdir reuses the existing inode (target inode of the mv -T command) with
S_DEAD flag.

Fix this by checking whether the target is directory or not and
calling cifs_rmdir() rather than cifs_unlink() for directories.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Pavel Shilovsky 2014-08-22 13:32:09 +04:00 committed by Steve French
parent 52a3624444
commit a07d322059

View File

@ -1720,6 +1720,9 @@ cifs_rename2(struct inode *source_dir, struct dentry *source_dentry,
unlink_target:
/* Try unlinking the target dentry if it's not negative */
if (target_dentry->d_inode && (rc == -EACCES || rc == -EEXIST)) {
if (d_is_dir(target_dentry))
tmprc = cifs_rmdir(target_dir, target_dentry);
else
tmprc = cifs_unlink(target_dir, target_dentry);
if (tmprc)
goto cifs_rename_exit;