Merge tag 'md/3.13-fixes' of git://neil.brown.name/md

Pull md fixes from Neil Brown:
 "Three bug fixes for md in 3.13-rc

  All recent regressions, one in 3.12 so marked for -stable"

* tag 'md/3.13-fixes' of git://neil.brown.name/md:
  md/raid5: fix newly-broken locking in get_active_stripe.
  md: test mddev->flags more safely in md_check_recovery.
  md/raid5: fix new memory-reference bug in alloc_thread_groups.
diff --git a/drivers/md/md.c b/drivers/md/md.c
index b6b7a28..e60cebf 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7777,7 +7777,7 @@
 	if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
 		return;
 	if ( ! (
-		(mddev->flags & ~ (1<<MD_CHANGE_PENDING)) ||
+		(mddev->flags & MD_UPDATE_SB_FLAGS & ~ (1<<MD_CHANGE_PENDING)) ||
 		test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
 		test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
 		(mddev->external == 0 && mddev->safemode == 1) ||
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 47da0af..cc055da 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -678,26 +678,23 @@
 			} else
 				init_stripe(sh, sector, previous);
 		} else {
+			spin_lock(&conf->device_lock);
 			if (atomic_read(&sh->count)) {
 				BUG_ON(!list_empty(&sh->lru)
 				    && !test_bit(STRIPE_EXPANDING, &sh->state)
 				    && !test_bit(STRIPE_ON_UNPLUG_LIST, &sh->state)
-				    && !test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
+					);
 			} else {
-				spin_lock(&conf->device_lock);
 				if (!test_bit(STRIPE_HANDLE, &sh->state))
 					atomic_inc(&conf->active_stripes);
-				if (list_empty(&sh->lru) &&
-				    !test_bit(STRIPE_ON_RELEASE_LIST, &sh->state) &&
-				    !test_bit(STRIPE_EXPANDING, &sh->state))
-					BUG();
+				BUG_ON(list_empty(&sh->lru));
 				list_del_init(&sh->lru);
 				if (sh->group) {
 					sh->group->stripes_cnt--;
 					sh->group = NULL;
 				}
-				spin_unlock(&conf->device_lock);
 			}
+			spin_unlock(&conf->device_lock);
 		}
 	} while (sh == NULL);
 
@@ -5471,7 +5468,7 @@
 	for (i = 0; i < *group_cnt; i++) {
 		struct r5worker_group *group;
 
-		group = worker_groups[i];
+		group = &(*worker_groups)[i];
 		INIT_LIST_HEAD(&group->handle_list);
 		group->conf = conf;
 		group->workers = workers + i * cnt;