From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bart Van Assche , Tejun Heo , Christoph Hellwig , Ming Lei , Omar Sandoval , Johannes Thumshirn , Alexandru Moise <00moses.alexander00@gmail.com>, Joseph Qi , Jens Axboe Subject: [PATCH 4.18 016/145] blkcg: Introduce blkg_root_lookup() Date: Fri, 7 Sep 2018 23:08:02 +0200 Message-Id: <20180907210904.883199291@linuxfoundation.org> In-Reply-To: <20180907210903.617721278@linuxfoundation.org> References: <20180907210903.617721278@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 6bad9b210a228d2fe0e0efe26d9b115348529cee upstream. This new function will be used in a later patch to verify whether a queue has been dissociated from the cgroup controller before being released. Signed-off-by: Bart Van Assche Cc: Tejun Heo Cc: Christoph Hellwig Cc: Ming Lei Cc: Omar Sandoval Cc: Johannes Thumshirn Cc: Alexandru Moise <00moses.alexander00@gmail.com> Cc: Joseph Qi Cc: Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- include/linux/blk-cgroup.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -296,6 +296,23 @@ static inline struct blkcg_gq *blkg_look } /** + * blkg_lookup - look up blkg for the specified request queue + * @q: request_queue of interest + * + * Lookup blkg for @q at the root level. See also blkg_lookup(). + */ +static inline struct blkcg_gq *blkg_root_lookup(struct request_queue *q) +{ + struct blkcg_gq *blkg; + + rcu_read_lock(); + blkg = blkg_lookup(&blkcg_root, q); + rcu_read_unlock(); + + return blkg; +} + +/** * blkg_to_pdata - get policy private data * @blkg: blkg of interest * @pol: policy of interest @@ -737,6 +754,7 @@ struct blkcg_policy { #ifdef CONFIG_BLOCK static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } +static inline struct blkcg_gq *blkg_root_lookup(struct request_queue *q) { return NULL; } static inline int blkcg_init_queue(struct request_queue *q) { return 0; } static inline void blkcg_drain_queue(struct request_queue *q) { } static inline void blkcg_exit_queue(struct request_queue *q) { }