From 496fb7806d616185a46865a4f3a20ef19dc6c7e3 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 19 Apr 2012 16:29:23 -0700 Subject: [PATCH] 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: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 82283859727e..30a7a9c58b38 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -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, -- 2.30.2