[PATCH v5 1/3] blkcg: Introduce blkg_root_lookup()
From: Bart Van Assche <hidden>
Date: 2018-08-09 14:53:36
Also in:
stable
Subsystem:
block layer, control group - block io controller (blkio), the rest · Maintainers:
Jens Axboe, Tejun Heo, Josef Bacik, Linus Torvalds
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 <redacted> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <redacted> Cc: Omar Sandoval <redacted> Cc: Johannes Thumshirn <redacted> Cc: Alexandru Moise <redacted> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: <redacted> --- include/linux/blk-cgroup.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index f7b910768306..1361cfc9b878 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h@@ -341,6 +341,23 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, return __blkg_lookup(blkcg, q, false); } +/** + * 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
@@ -864,6 +881,7 @@ 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 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) { }
--
2.18.0