diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 290792a..db30b6b 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -235,8 +235,13 @@
 	blkg->online = true;
 	spin_unlock(&blkcg->lock);
 
-	if (!ret)
+	if (!ret) {
+		if (blkcg == &blkcg_root) {
+			q->root_blkg = blkg;
+			q->root_rl.blkg = blkg;
+		}
 		return blkg;
+	}
 
 	/* @blkg failed fully initialized, use the usual release path */
 	blkg_put(blkg);
@@ -335,6 +340,15 @@
 		rcu_assign_pointer(blkcg->blkg_hint, NULL);
 
 	/*
+	 * If root blkg is destroyed.  Just clear the pointer since root_rl
+	 * does not take reference on root blkg.
+	 */
+	if (blkcg == &blkcg_root) {
+		blkg->q->root_blkg = NULL;
+		blkg->q->root_rl.blkg = NULL;
+	}
+
+	/*
 	 * Put the reference taken at the time of creation so that when all
 	 * queues are gone, group can be destroyed.
 	 */
@@ -360,13 +374,6 @@
 		blkg_destroy(blkg);
 		spin_unlock(&blkcg->lock);
 	}
-
-	/*
-	 * root blkg is destroyed.  Just clear the pointer since
-	 * root_rl does not take reference on root blkg.
-	 */
-	q->root_blkg = NULL;
-	q->root_rl.blkg = NULL;
 }
 
 /*
@@ -973,8 +980,6 @@
 		ret = PTR_ERR(blkg);
 		goto out_unlock;
 	}
-	q->root_blkg = blkg;
-	q->root_rl.blkg = blkg;
 
 	list_for_each_entry(blkg, &q->blkg_list, q_node)
 		cnt++;