From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 06/14] block: move the bio cgroup associatation helpers to blk-cgroup.c Date: Sat, 27 Jun 2020 09:31:51 +0200 Message-ID: <20200627073159.2447325-7-hch@lst.de> References: <20200627073159.2447325-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200627073159.2447325-1-hch@lst.de> Sender: linux-block-owner@vger.kernel.org To: Jens Axboe , Tejun Heo Cc: Dennis Zhou , Li Zefan , Johannes Weiner , dm-devel@redhat.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org List-Id: dm-devel.ids Keep the cgroup code together. Signed-off-by: Christoph Hellwig --- block/bio.c | 75 --------------------------- block/blk-cgroup.c | 103 ++++++++++++++++++++++++++++++++++++- include/linux/blk-cgroup.h | 30 ----------- 3 files changed, 101 insertions(+), 107 deletions(-) diff --git a/block/bio.c b/block/bio.c index 901d22715dd4f3..fc1299f9d86a24 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1627,81 +1627,6 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) } EXPORT_SYMBOL(bioset_init_from_src); -#ifdef CONFIG_BLK_CGROUP -/** - * bio_associate_blkg_from_css - associate a bio with a specified css - * @bio: target bio - * @css: target css - * - * Associate @bio with the blkg found by combining the css's blkg and the - * request_queue of the @bio. An association failure is handled by walking up - * the blkg tree. Therefore, the blkg associated can be anything between @blkg - * and q->root_blkg. This situation only happens when a cgroup is dying and - * then the remaining bios will spill to the closest alive blkg. - * - * A reference will be taken on the blkg and will be released when @bio is - * freed. - */ -void bio_associate_blkg_from_css(struct bio *bio, - struct cgroup_subsys_state *css) -{ - struct request_queue *q = bio->bi_disk->queue; - struct blkcg_gq *blkg = q->root_blkg; - - if (bio->bi_blkg) - blkg_put(bio->bi_blkg); - - rcu_read_lock(); - if (css && css->parent) - blkg = blkg_lookup_create(css_to_blkcg(css), q); - bio->bi_blkg = blkg_tryget_closest(blkg); - rcu_read_unlock(); -} -EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css); - -/** - * 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 cgroup_subsys_state *css; - - rcu_read_lock(); - - if (bio->bi_blkg) - css = &bio_blkcg(bio)->css; - else - css = blkcg_css(); - - bio_associate_blkg_from_css(bio, css); - - rcu_read_unlock(); -} -EXPORT_SYMBOL_GPL(bio_associate_blkg); - -/** - * bio_clone_blkg_association - clone blkg association from src to dst bio - * @dst: destination bio - * @src: source bio - */ -void bio_clone_blkg_association(struct bio *dst, struct bio *src) -{ - if (src->bi_blkg) { - if (dst->bi_blkg) - blkg_put(dst->bi_blkg); - blkg_get(src->bi_blkg); - dst->bi_blkg = src->bi_blkg; - } -} -EXPORT_SYMBOL_GPL(bio_clone_blkg_association); -#endif /* CONFIG_BLK_CGROUP */ - static void __init biovec_init_slabs(void) { int i; diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 0ecc897b225c96..bb0607bfd771cd 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -328,7 +328,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, * Returns the blkg or the closest blkg if blkg_create() fails as it walks * down from root. */ -struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, +static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, struct request_queue *q) { struct blkcg_gq *blkg; @@ -377,7 +377,7 @@ struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, * This looks up or creates the blkg representing the unique pair * of the blkcg and the request_queue. */ -struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, +static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, struct request_queue *q) { struct blkcg_gq *blkg = blkg_lookup(blkcg, q); @@ -1727,6 +1727,105 @@ void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta) atomic64_add(delta, &blkg->delay_nsec); } +/** + * blkg_tryget_closest - try and get a blkg ref on the closet blkg + * @blkg: blkg to get + * + * This needs to be called rcu protected. As the failure mode here is to walk + * up the blkg tree, this ensure that the blkg->parent pointers are always + * valid. This returns the blkg that it ended up taking a reference on or %NULL + * if no reference was taken. + */ +static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg) +{ + struct blkcg_gq *ret_blkg = NULL; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + while (blkg) { + if (blkg_tryget(blkg)) { + ret_blkg = blkg; + break; + } + blkg = blkg->parent; + } + + return ret_blkg; +} + +/** + * bio_associate_blkg_from_css - associate a bio with a specified css + * @bio: target bio + * @css: target css + * + * Associate @bio with the blkg found by combining the css's blkg and the + * request_queue of the @bio. An association failure is handled by walking up + * the blkg tree. Therefore, the blkg associated can be anything between @blkg + * and q->root_blkg. This situation only happens when a cgroup is dying and + * then the remaining bios will spill to the closest alive blkg. + * + * A reference will be taken on the blkg and will be released when @bio is + * freed. + */ +void bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) +{ + struct request_queue *q = bio->bi_disk->queue; + struct blkcg_gq *blkg = q->root_blkg; + + if (bio->bi_blkg) + blkg_put(bio->bi_blkg); + + rcu_read_lock(); + if (css && css->parent) + blkg = blkg_lookup_create(css_to_blkcg(css), q); + bio->bi_blkg = blkg_tryget_closest(blkg); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css); + +/** + * 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 cgroup_subsys_state *css; + + rcu_read_lock(); + + if (bio->bi_blkg) + css = &bio_blkcg(bio)->css; + else + css = blkcg_css(); + + bio_associate_blkg_from_css(bio, css); + + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(bio_associate_blkg); + +/** + * bio_clone_blkg_association - clone blkg association from src to dst bio + * @dst: destination bio + * @src: source bio + */ +void bio_clone_blkg_association(struct bio *dst, struct bio *src) +{ + if (src->bi_blkg) { + if (dst->bi_blkg) + blkg_put(dst->bi_blkg); + blkg_get(src->bi_blkg); + dst->bi_blkg = src->bi_blkg; + } +} +EXPORT_SYMBOL_GPL(bio_clone_blkg_association); + static int __init blkcg_init(void) { blkcg_punt_bio_wq = alloc_workqueue("blkcg_punt_bio", diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index a57ebe2f00abd8..60df97202314c7 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -183,10 +183,6 @@ extern bool blkcg_debug_stats; struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg, struct request_queue *q, bool update_hint); -struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, - struct request_queue *q); -struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, - struct request_queue *q); int blkcg_init_queue(struct request_queue *q); void blkcg_exit_queue(struct request_queue *q); @@ -480,32 +476,6 @@ static inline bool blkg_tryget(struct blkcg_gq *blkg) return blkg && percpu_ref_tryget(&blkg->refcnt); } -/** - * blkg_tryget_closest - try and get a blkg ref on the closet blkg - * @blkg: blkg to get - * - * This needs to be called rcu protected. As the failure mode here is to walk - * up the blkg tree, this ensure that the blkg->parent pointers are always - * valid. This returns the blkg that it ended up taking a reference on or %NULL - * if no reference was taken. - */ -static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg) -{ - struct blkcg_gq *ret_blkg = NULL; - - WARN_ON_ONCE(!rcu_read_lock_held()); - - while (blkg) { - if (blkg_tryget(blkg)) { - ret_blkg = blkg; - break; - } - blkg = blkg->parent; - } - - return ret_blkg; -} - /** * blkg_put - put a blkg reference * @blkg: blkg to put -- 2.26.2