diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index eb0cfb10b859..047bb42c282b 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1566,6 +1566,8 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 
 	if (queue_is_mq(q))
 		memflags = blk_mq_freeze_queue(q);
+
+	mutex_lock(&q->blkcg_mutex);
 retry:
 	spin_lock_irq(&q->queue_lock);
 
@@ -1628,6 +1630,7 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 
 	spin_unlock_irq(&q->queue_lock);
 out:
+	mutex_unlock(&q->blkcg_mutex);
 	if (queue_is_mq(q))
 		blk_mq_unfreeze_queue(q, memflags);
 	if (pinned_blkg)