f2fs: allow empty strings for journaled quota options

Commit 2a3db1e02ce0 ("f2fs: allow empty mount string for
Opt_usr|grp|projjquota") added support for passing usrjquota,
grpjquota and prjjquota as flags to disable journaled quotas.

However, it also replaced fsparam_string_empty() with fsparam_string(),
which rejects an empty string. As of now, mount(2) and
fsconfig(FSCONFIG_SET_STRING) reject usrjquota=, grpjquota= and
prjjquota= with EINVAL, although these forms are still documented in
Documentation/filesystems/f2fs.rst.

The issue can be reproduced on an F2FS device with:

    mount -t f2fs -o usrjquota= /dev/loop5 /mnt/f

Before this commit, the command succeeds. Afterwards, it fails with
EINVAL and logs "f2fs: Bad value for 'usrjquota'".
The same failure occurs when remounting to clear a quota file name.

This patch will restore fsparam_string_empty() for the three options
while retaining the flag entries, so both forms are accepted.

Fixes: 2a3db1e02ce0 ("f2fs: allow empty mount string for Opt_usr|grp|projjquota")
Cc: stable@vger.kernel.org # 7.1+
Signed-off-by: Hengyu Liang <hengyul@cs.unc.edu>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

0 files changed, 0 insertions, 0 deletions