diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 8038c2b83f8537ebb491dcef76ff44c814a7cc2c..4a8151ecd8a665e8ce3bf84f26e1b035349fe2bf 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1445,7 +1445,8 @@ 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])