ext4: correctly report "not supported" for {usr,grp}jquota when !CONFIG_QUOTA

The macro MOPT_Q is used to indicates the mount option is related to
quota stuff and is defined to be MOPT_NOSUPPORT when CONFIG_QUOTA is
disabled.  Normally the quota options are handled explicitly, so it
didn't matter that the MOPT_STRING flag was missing, even though the
usrjquota and grpjquota mount options take a string argument.  It's
important that's present in the !CONFIG_QUOTA case, since without
MOPT_STRING, the mount option matcher will match usrjquota= followed
by an integer, and will otherwise skip the table entry, and so "mount
option not supported" error message is never reported.

[ Fixed up the commit description to better explain why the fix
  works. --TYT ]

Fixes: 26092bf52478 ("ext4: use a table-driven handler for mount options")
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Link: https://lore.kernel.org/r/1603986396-28917-1-git-send-email-kaixuxia@tencent.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ef4734b40e2a2808e637ba7f6f738fce4904ce2b..5dbbd48923c179a7f788da1cb0a56e417fdf56a2 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2027,8 +2027,8 @@ static const struct mount_opts {
        {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
                       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
                                                        MOPT_CLEAR | MOPT_Q},
-       {Opt_usrjquota, 0, MOPT_Q},
-       {Opt_grpjquota, 0, MOPT_Q},
+       {Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
+       {Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
        {Opt_offusrjquota, 0, MOPT_Q},
        {Opt_offgrpjquota, 0, MOPT_Q},
        {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},