diff --git a/drivers/md/md.h b/drivers/md/md.h
index e41559d..8770308 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -392,6 +392,7 @@
 	 *   clearing MD_CHANGE_*
 	 *   in_sync - and related safemode and MD_CHANGE changes
 	 *   pers (also protected by reconfig_mutex and pending IO).
+	 *   clearing ->bitmap
 	 */
 	spinlock_t			lock;
 	wait_queue_head_t		sb_wait;	/* for waiting on superblock updates */