Commit 496fb780 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

blkcg: fix blkcg->css ref leak in __blkg_lookup_create() 



__blkg_lookup_create() leaked blkcg->css ref if blkg allocation
failed.  Fix it.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent aaf7c680

block/blk-cgroup.c

+9 −10
Original line number Diff line number Diff line
@@ -174,6 +174,7 @@ static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, 
	__releases(q->queue_lock) __acquires(q->queue_lock)

{

	struct blkcg_gq *blkg;

	int ret;



	WARN_ON_ONCE(!rcu_read_lock_held());

	lockdep_assert_held(q->queue_lock);
@@ -186,24 +187,22 @@ static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, 
	if (!css_tryget(&blkcg->css))

		return ERR_PTR(-EINVAL);



	/*

	 * Allocate and initialize.

	 */

	/* allocate */

	ret = -ENOMEM;

	blkg = blkg_alloc(blkcg, q);



	/* did alloc fail? */

	if (unlikely(!blkg)) {

		blkg = ERR_PTR(-ENOMEM);

		goto out;

	}

	if (unlikely(!blkg))

		goto err_put;



	/* insert */

	spin_lock(&blkcg->lock);

	hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);

	list_add(&blkg->q_node, &q->blkg_list);

	spin_unlock(&blkcg->lock);

out:

	return blkg;



err_put:

	css_put(&blkcg->css);

	return ERR_PTR(ret);

}



struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,