1 files changed, 13 insertions, 10 deletions

diff --git a/block/elevator.c b/block/elevator.c
index fa828b5bfd4b..6a06b5d040e5 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -895,8 +895,7 @@ int elv_register(struct elevator_type *e)
 	spin_lock(&elv_list_lock);
 	if (elevator_find(e->elevator_name, e->uses_mq)) {
 		spin_unlock(&elv_list_lock);
-		if (e->icq_cache)
-			kmem_cache_destroy(e->icq_cache);
+		kmem_cache_destroy(e->icq_cache);
 		return -EBUSY;
 	}
 	list_add_tail(&e->list, &elv_list);
@@ -933,16 +932,13 @@ void elv_unregister(struct elevator_type *e)
 }
 EXPORT_SYMBOL_GPL(elv_unregister);
 
-static int elevator_switch_mq(struct request_queue *q,
+int elevator_switch_mq(struct request_queue *q,
 			      struct elevator_type *new_e)
 {
 	int ret;
 
 	lockdep_assert_held(&q->sysfs_lock);
 
-	blk_mq_freeze_queue(q);
-	blk_mq_quiesce_queue(q);
-
 	if (q->elevator) {
 		if (q->elevator->registered)
 			elv_unregister_queue(q);
@@ -968,8 +964,6 @@ static int elevator_switch_mq(struct request_queue *q,
 		blk_add_trace_msg(q, "elv switch: none");
 
 out:
-	blk_mq_unquiesce_queue(q);
-	blk_mq_unfreeze_queue(q);
 	return ret;
 }
 
@@ -1021,8 +1015,17 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
 
 	lockdep_assert_held(&q->sysfs_lock);
 
-	if (q->mq_ops)
-		return elevator_switch_mq(q, new_e);
+	if (q->mq_ops) {
+		blk_mq_freeze_queue(q);
+		blk_mq_quiesce_queue(q);
+
+		err = elevator_switch_mq(q, new_e);
+
+		blk_mq_unquiesce_queue(q);
+		blk_mq_unfreeze_queue(q);
+
+		return err;
+	}
 
 	/*
 	 * Turn on BYPASS and drain all requests w/ elevator private data.