ext4: force ro mount if ext4_setup_super() fails

commit 7e84b6216467b84cd332c8e567bf5aa113fd2f38 upstream.

If ext4_setup_super() fails i.e. due to a too-high revision,
the error is logged in dmesg but the fs is not mounted RO as
indicated.

Tested by:

# mkfs.ext4 -r 4 /dev/sdb6
# mount /dev/sdb6 /mnt/test
# dmesg | grep "too high"
[164919.759248] EXT4-fs (sdb6): revision level too high, forcing read-only mode
# grep sdb6 /proc/mounts
/dev/sdb6 /mnt/test2 ext4 rw,seclabel,relatime,data=ordered 0 0

Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index df121b20b0d..be6c0ccd822 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3618,7 +3618,8 @@ no_journal:
                 goto failed_mount4;
         }
 
-        ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
+        if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
+                sb->s_flags |= MS_RDONLY;
 
         /* determine the minimum size of new large inodes, if present */
         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {