From b86d865cb1cae1e61527ea0b8977078bbf694328 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 10 Aug 2018 13:28:07 -0700 Subject: [PATCH] blkcg: Make blkg_root_lookup() work for queues in bypass mode For legacy queues the only call of blkg_root_lookup() happens after bypass mode has been enabled. Since blkg_lookup() returns NULL for queues in bypass mode, modify the blkg_root_lookup() such that it no longer depends on bypass mode. Rename the function into blk_queue_root_blkg() as suggested by Tejun. Suggested-by: Tejun Heo Fixes: 6bad9b210a22 ("blkcg: Introduce blkg_root_lookup()") Signed-off-by: Bart Van Assche Cc: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 2 +- include/linux/blk-cgroup.h | 15 +++++---------- 2 files changed, 6 insertions(+), 11 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 380bc284ced1..bb109bb0a055 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -813,7 +813,7 @@ static void __blk_release_queue(struct work_struct *work) blk_exit_queue(q); } - WARN(blkg_root_lookup(q), + WARN(blk_queue_root_blkg(q), "request queue %p is being released but it has not yet been removed from the blkcg controller\n", q); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 1361cfc9b878..34aec30e06c7 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -342,20 +342,14 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, } /** - * blkg_lookup - look up blkg for the specified request queue + * blk_queue_root_blkg - return blkg for the (blkcg_root, @q) pair * @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) +static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q) { - struct blkcg_gq *blkg; - - rcu_read_lock(); - blkg = blkg_lookup(&blkcg_root, q); - rcu_read_unlock(); - - return blkg; + return q->root_blkg; } /** @@ -881,7 +875,8 @@ static inline bool blk_cgroup_congested(void) { return false; } static inline void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) { } 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 struct blkcg_gq *blk_queue_root_blkg(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) { } -- GitLab