diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 290792a13e3c..db30b6beee72 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -235,8 +235,13 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, 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); @@ -334,6 +339,15 @@ static void blkg_destroy(struct blkcg_gq *blkg) if (rcu_dereference_raw(blkcg->blkg_hint) == blkg) 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 @@ static void blkg_destroy_all(struct request_queue *q) 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 @@ int blkcg_activate_policy(struct request_queue *q, 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++;