diff options
Diffstat (limited to 'block/blk-cgroup.h')
| -rw-r--r-- | block/blk-cgroup.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 3e91803c4a55..47e1e38390c9 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -15,6 +15,7 @@ */ #include <linux/blk-cgroup.h> +#include <linux/blk-mq.h> /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) @@ -428,6 +429,21 @@ static inline void blkcg_clear_delay(struct blkcg_gq *blkg) atomic_dec(&blkg->blkcg->css.cgroup->congestion_count); } +/** + * blk_cgroup_mergeable - Determine whether to allow or disallow merges + * @rq: request to merge into + * @bio: bio to merge + * + * @bio and @rq should belong to the same cgroup and their issue_as_root should + * match. The latter is necessary as we don't want to throttle e.g. a metadata + * update because it happens to be next to a regular IO. + */ +static inline bool blk_cgroup_mergeable(struct request *rq, struct bio *bio) +{ + return rq->bio->bi_blkg == bio->bi_blkg && + bio_issue_as_root_blkg(rq->bio) == bio_issue_as_root_blkg(bio); +} + void blk_cgroup_bio_start(struct bio *bio); void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta); #else /* CONFIG_BLK_CGROUP */ @@ -467,6 +483,7 @@ static inline void blkg_put(struct blkcg_gq *blkg) { } static inline bool blkcg_punt_bio_submit(struct bio *bio) { return false; } static inline void blkcg_bio_issue_init(struct bio *bio) { } static inline void blk_cgroup_bio_start(struct bio *bio) { } +static inline bool blk_cgroup_mergeable(struct request *rq, struct bio *bio) { return true; } #define blk_queue_for_each_rl(rl, q) \ for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) |