xfs: don't leak uuid table on rmmod

Don't leak the UUID table when the module is unloaded.
(Found with kmemleak.)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_mount.c

@@ -47,6 +47,16 @@ static DEFINE_MUTEX(xfs_uuid_table_mutex);
 static int xfs_uuid_table_size;
 static uuid_t *xfs_uuid_table;
 
+void
+xfs_uuid_table_free(void)
+{
+	if (xfs_uuid_table_size == 0)
+		return;
+	kmem_free(xfs_uuid_table);
+	xfs_uuid_table = NULL;
+	xfs_uuid_table_size = 0;
+}
+
 /*
  * See if the UUID is unique among mounted XFS filesystems.
  * Mount fails if UUID is nil or a FS with the same UUID is already mounted.

fs/xfs/xfs_mount.h

@@ -312,6 +312,7 @@ typedef struct xfs_perag {
 	int		pagb_count;	/* pagb slots in use */
 } xfs_perag_t;
 
+extern void	xfs_uuid_table_free(void);
 extern int	xfs_log_sbcount(xfs_mount_t *);
 extern __uint64_t xfs_default_resblks(xfs_mount_t *mp);
 extern int	xfs_mountfs(xfs_mount_t *mp);

fs/xfs/xfs_super.c

@@ -1896,6 +1896,7 @@ exit_xfs_fs(void)
 	xfs_mru_cache_uninit();
 	xfs_destroy_workqueues();
 	xfs_destroy_zones();
+	xfs_uuid_table_free();
 }
 
 module_init(init_xfs_fs);