diff options
| author | Bart Van Assche <bart.vanassche@wdc.com> | 2018-08-09 07:53:36 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-08-09 09:12:57 -0600 |
| commit | 6bad9b210a228d2fe0e0efe26d9b115348529cee (patch) | |
| tree | 6371fc42fc0b3d145ae8d32ae3d9331c916bfe57 | |
| parent | b1f4267cc5448d20ae0c515a74141e74365e78a3 (diff) | |
blkcg: Introduce blkg_root_lookup()
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 <bart.vanassche@wdc.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alexandru Moise <00moses.alexander00@gmail.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | include/linux/blk-cgroup.h | 18 |
1 files changed, 18 insertions, 0 deletions
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 @@ -342,6 +342,23 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, } /** + * 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 @@ -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) { } |