Re: [PATCH] f2fs: allow empty strings for journaled quota options

[Chao Yu <chao@kernel.org>]

On 10/11/26 00:57, Hengyu Liang wrote:
> 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>

Thanks,