diff options
| -rw-r--r-- | block/bio.c | 62 | ||||
| -rw-r--r-- | block/blk-iolatency.c | 10 | ||||
| -rw-r--r-- | block/blk-throttle.c | 6 | ||||
| -rw-r--r-- | include/linux/bio.h | 5 |
4 files changed, 62 insertions, 21 deletions
diff --git a/block/bio.c b/block/bio.c index 5c9828524adc..452b8e79b998 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2009,7 +2009,21 @@ int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) EXPORT_SYMBOL_GPL(bio_associate_blkcg); /** - * bio_associate_blkg - associate a bio with the a blkg + * bio_disassociate_blkg - puts back the blkg reference if associated + * @bio: target bio + * + * Helper to disassociate the blkg from @bio if a blkg is associated. + */ +void bio_disassociate_blkg(struct bio *bio) +{ + if (bio->bi_blkg) { + blkg_put(bio->bi_blkg); + bio->bi_blkg = NULL; + } +} + +/** + * __bio_associate_blkg - associate a bio with the a blkg * @bio: target bio * @blkg: the blkg to associate * @@ -2022,12 +2036,42 @@ EXPORT_SYMBOL_GPL(bio_associate_blkcg); * A reference will be taken on the @blkg and will be released when @bio is * freed. */ -int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) +static void __bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) { - if (unlikely(bio->bi_blkg)) - return -EBUSY; + bio_disassociate_blkg(bio); + bio->bi_blkg = blkg_try_get_closest(blkg); - return 0; +} + +/** + * bio_associate_blkg - associate a bio with a blkg + * @bio: target bio + * + * Associate @bio with the blkg found from the bio's css and request_queue. + * If one is not found, bio_lookup_blkg() creates the blkg. If a blkg is + * already associated, the css is reused and association redone as the + * request_queue may have changed. + */ +void bio_associate_blkg(struct bio *bio) +{ + struct request_queue *q = bio->bi_disk->queue; + struct blkcg *blkcg; + struct blkcg_gq *blkg; + + rcu_read_lock(); + + bio_associate_blkcg(bio, NULL); + blkcg = bio_blkcg(bio); + + if (!blkcg->css.parent) { + __bio_associate_blkg(bio, q->root_blkg); + } else { + blkg = blkg_lookup_create(blkcg, q); + + __bio_associate_blkg(bio, blkg); + } + + rcu_read_unlock(); } /** @@ -2040,10 +2084,7 @@ void bio_disassociate_task(struct bio *bio) css_put(bio->bi_css); bio->bi_css = NULL; } - if (bio->bi_blkg) { - blkg_put(bio->bi_blkg); - bio->bi_blkg = NULL; - } + bio_disassociate_blkg(bio); } /** @@ -2055,6 +2096,9 @@ void bio_clone_blkcg_association(struct bio *dst, struct bio *src) { if (src->bi_css) WARN_ON(bio_associate_blkcg(dst, src->bi_css)); + + if (src->bi_blkg) + __bio_associate_blkg(dst, src->bi_blkg); } EXPORT_SYMBOL_GPL(bio_clone_blkcg_association); #endif /* CONFIG_BLK_CGROUP */ diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 46e86c34cf79..cdbd10564e66 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -472,21 +472,15 @@ static void check_scale_change(struct iolatency_grp *iolat) static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio) { struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos); - struct blkcg *blkcg; struct blkcg_gq *blkg; - struct request_queue *q = rqos->q; bool issue_as_root = bio_issue_as_root_blkg(bio); if (!blk_iolatency_enabled(blkiolat)) return; - rcu_read_lock(); - bio_associate_blkcg(bio, NULL); - blkcg = bio_blkcg(bio); - blkg = blkg_lookup_create(blkcg, q); + bio_associate_blkg(bio); + blkg = bio->bi_blkg; bio_issue_init(&bio->bi_issue, bio_sectors(bio)); - bio_associate_blkg(bio, blkg); - rcu_read_unlock(); while (blkg && blkg->parent) { struct iolatency_grp *iolat = blkg_to_lat(blkg); diff --git a/block/blk-throttle.c b/block/blk-throttle.c index d648d6720f46..228c3a007ebc 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2115,10 +2115,10 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td) } #endif -static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio) +static void blk_throtl_assoc_bio(struct bio *bio) { #ifdef CONFIG_BLK_DEV_THROTTLING_LOW - bio_associate_blkg(bio, tg_to_blkg(tg)); + bio_associate_blkg(bio); bio_issue_init(&bio->bi_issue, bio_sectors(bio)); #endif } @@ -2143,7 +2143,7 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, throtl_update_latency_buckets(td); - blk_throtl_assoc_bio(tg, bio); + blk_throtl_assoc_bio(bio); blk_throtl_update_idletime(tg); sq = &tg->service_queue; diff --git a/include/linux/bio.h b/include/linux/bio.h index 056fb627edb3..62715a5a4f32 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -511,12 +511,15 @@ static inline int bio_associate_blkcg_from_page(struct bio *bio, #ifdef CONFIG_BLK_CGROUP int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); -int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg); +void bio_disassociate_blkg(struct bio *bio); +void bio_associate_blkg(struct bio *bio); void bio_disassociate_task(struct bio *bio); void bio_clone_blkcg_association(struct bio *dst, struct bio *src); #else /* CONFIG_BLK_CGROUP */ static inline int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { return 0; } +static inline void bio_disassociate_blkg(struct bio *bio) { } +static inline void bio_associate_blkg(struct bio *bio) { } static inline void bio_disassociate_task(struct bio *bio) { } static inline void bio_clone_blkcg_association(struct bio *dst, struct bio *src) { } |