diff --git a/drivers/md/md.h b/drivers/md/md.h
index 7ab5ea1..10597bf 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -78,6 +78,9 @@
 
 	int desc_nr;			/* descriptor index in the superblock */
 	int raid_disk;			/* role of device in array */
+	int new_raid_disk;		/* role that the device will have in
+					 * the array after a level-change completes.
+					 */
 	int saved_raid_disk;		/* role that device used to have in the
 					 * array and could again if we did a partial
 					 * resync from the bitmap