diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index d5ec7f9b460df26b87360d2e64ec6a33e4149d7f..f89bd84a180f01609ecff5e27e91c2f2ce41a5d9 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1443,7 +1443,8 @@ int blkcg_activate_policy(struct request_queue *q,
 
 	spin_lock_irq(q->queue_lock);
 
-	list_for_each_entry(blkg, &q->blkg_list, q_node) {
+	/* blkg_list is pushed at the head, reverse walk to init parents first */
+	list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) {
 		struct blkg_policy_data *pd;
 
 		if (blkg->pd[pol->plid])