GFS2 uses i_mutex on its system quota inode to synchronize writes to
quota file. Since this is an internal inode to GFS2 (not part of directory
hiearchy or visible by user) we are safe to define locking rules for it. So
let's just get it its own locking class to make it clear.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>