From 69840466086d2248898020a08dda52732686c4e6 Mon Sep 17 00:00:00 2001 From: Jianchao Wang Date: Sat, 27 Oct 2018 19:52:14 +0800 Subject: block: fix the DISCARD request merge There are two cases when handle DISCARD merge. If max_discard_segments == 1, the bios/requests need to be contiguous to merge. If max_discard_segments > 1, it takes every bio as a range and different range needn't to be contiguous. But now, attempt_merge screws this up. It always consider contiguity for DISCARD for the case max_discard_segments > 1 and cannot merge contiguous DISCARD for the case max_discard_segments == 1, because rq_attempt_discard_merge always returns false in this case. This patch fixes both of the two cases above. Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jianchao Wang Signed-off-by: Jens Axboe --- block/blk-merge.c | 46 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 36 insertions(+), 10 deletions(-) (limited to 'block') diff --git a/block/blk-merge.c b/block/blk-merge.c index 42a46744c11b..6b5ad275ed56 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -714,6 +714,31 @@ static void blk_account_io_merge(struct request *req) part_stat_unlock(); } } +/* + * Two cases of handling DISCARD merge: + * If max_discard_segments > 1, the driver takes every bio + * as a range and send them to controller together. The ranges + * needn't to be contiguous. + * Otherwise, the bios/requests will be handled as same as + * others which should be contiguous. + */ +static inline bool blk_discard_mergable(struct request *req) +{ + if (req_op(req) == REQ_OP_DISCARD && + queue_max_discard_segments(req->q) > 1) + return true; + return false; +} + +enum elv_merge blk_try_req_merge(struct request *req, struct request *next) +{ + if (blk_discard_mergable(req)) + return ELEVATOR_DISCARD_MERGE; + else if (blk_rq_pos(req) + blk_rq_sectors(req) == blk_rq_pos(next)) + return ELEVATOR_BACK_MERGE; + + return ELEVATOR_NO_MERGE; +} /* * For non-mq, this has to be called with the request spinlock acquired. @@ -731,12 +756,6 @@ static struct request *attempt_merge(struct request_queue *q, if (req_op(req) != req_op(next)) return NULL; - /* - * not contiguous - */ - if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next)) - return NULL; - if (rq_data_dir(req) != rq_data_dir(next) || req->rq_disk != next->rq_disk || req_no_special_merge(next)) @@ -760,11 +779,19 @@ static struct request *attempt_merge(struct request_queue *q, * counts here. Handle DISCARDs separately, as they * have separate settings. */ - if (req_op(req) == REQ_OP_DISCARD) { + + switch (blk_try_req_merge(req, next)) { + case ELEVATOR_DISCARD_MERGE: if (!req_attempt_discard_merge(q, req, next)) return NULL; - } else if (!ll_merge_requests_fn(q, req, next)) + break; + case ELEVATOR_BACK_MERGE: + if (!ll_merge_requests_fn(q, req, next)) + return NULL; + break; + default: return NULL; + } /* * If failfast settings disagree or any of the two is already @@ -888,8 +915,7 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) enum elv_merge blk_try_merge(struct request *rq, struct bio *bio) { - if (req_op(rq) == REQ_OP_DISCARD && - queue_max_discard_segments(rq->q) > 1) + if (blk_discard_mergable(rq)) return ELEVATOR_DISCARD_MERGE; else if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector) return ELEVATOR_BACK_MERGE; -- cgit v1.2.3 From c57cdf7a9e51d97a43e29b8f4a04157875104000 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 24 Oct 2018 21:18:09 +0800 Subject: block: call rq_qos_exit() after queue is frozen rq_qos_exit() removes the current q->rq_qos, this action has to be done after queue is frozen, otherwise the IO queue path may never be waken up, then IO hang is caused. So fixes this issue by moving rq_qos_exit() after queue is frozen. Cc: Josef Bacik Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-core.c | 3 +++ block/blk-sysfs.c | 2 -- 2 files changed, 3 insertions(+), 2 deletions(-) (limited to 'block') diff --git a/block/blk-core.c b/block/blk-core.c index bc6ea87d10e0..26a5dac80ed9 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -785,6 +785,9 @@ void blk_cleanup_queue(struct request_queue *q) * prevent that q->request_fn() gets invoked after draining finished. */ blk_freeze_queue(q); + + rq_qos_exit(q); + spin_lock_irq(lock); queue_flag_set(QUEUE_FLAG_DEAD, q); spin_unlock_irq(lock); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 0641533597f1..844a454a7b3a 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -1007,8 +1007,6 @@ void blk_unregister_queue(struct gendisk *disk) kobject_del(&q->kobj); blk_trace_remove_sysfs(disk_to_dev(disk)); - rq_qos_exit(q); - mutex_lock(&q->sysfs_lock); if (q->request_fn || (q->mq_ops && q->elevator)) elv_unregister_queue(q); -- cgit v1.2.3 From b5f2954d30c77649bce9c27e7a0a94299d9cfdf8 Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Thu, 1 Nov 2018 17:24:10 -0400 Subject: blkcg: revert blkcg cleanups series This reverts a series committed earlier due to null pointer exception bug report in [1]. It seems there are edge case interactions that I did not consider and will need some time to understand what causes the adverse interactions. The original series can be found in [2] with a follow up series in [3]. [1] https://www.spinics.net/lists/cgroups/msg20719.html [2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/ [3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/ This reverts the following commits: d459d853c2ed, b2c3fa546705, 101246ec02b5, b3b9f24f5fcc, e2b0989954ae, f0fcb3ec89f3, c839e7a03f92, bdc2491708c4, 74b7c02a9bc1, 5bf9a1f3b4ef, a7b39b4e961c, 07b05bcc3213, 49f4c2dc2b50, 27e6fa996c53 Signed-off-by: Dennis Zhou Signed-off-by: Jens Axboe --- block/bfq-cgroup.c | 4 +- block/bfq-iosched.c | 2 +- block/bio.c | 174 ++++++++++++++------------------------------------ block/blk-cgroup.c | 123 +++++++++++------------------------ block/blk-core.c | 1 - block/blk-iolatency.c | 26 +++++++- block/blk-throttle.c | 13 +++- block/bounce.c | 4 +- block/cfq-iosched.c | 4 +- 9 files changed, 127 insertions(+), 224 deletions(-) (limited to 'block') diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index d9a7916ff0ab..9fe5952d117d 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -642,7 +642,7 @@ void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) uint64_t serial_nr; rcu_read_lock(); - serial_nr = __bio_blkcg(bio)->css.serial_nr; + serial_nr = bio_blkcg(bio)->css.serial_nr; /* * Check whether blkcg has changed. The condition may trigger @@ -651,7 +651,7 @@ void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr)) goto out; - bfqg = __bfq_bic_change_cgroup(bfqd, bic, __bio_blkcg(bio)); + bfqg = __bfq_bic_change_cgroup(bfqd, bic, bio_blkcg(bio)); /* * Update blkg_path for bfq_log_* functions. We cache this * path, and update it here, for the following diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 6075100f03a5..3a27d31fcda6 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4384,7 +4384,7 @@ static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd, rcu_read_lock(); - bfqg = bfq_find_set_group(bfqd, __bio_blkcg(bio)); + bfqg = bfq_find_set_group(bfqd, bio_blkcg(bio)); if (!bfqg) { bfqq = &bfqd->oom_bfqq; goto out; diff --git a/block/bio.c b/block/bio.c index bbfeb4ee2892..4a5a036268fb 100644 --- a/block/bio.c +++ b/block/bio.c @@ -609,9 +609,7 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src) bio->bi_iter = bio_src->bi_iter; bio->bi_io_vec = bio_src->bi_io_vec; - bio_clone_blkg_association(bio, bio_src); - - blkcg_bio_issue_init(bio); + bio_clone_blkcg_association(bio, bio_src); } EXPORT_SYMBOL(__bio_clone_fast); @@ -1956,151 +1954,69 @@ EXPORT_SYMBOL(bioset_init_from_src); #ifdef CONFIG_BLK_CGROUP -/** - * bio_associate_blkg - associate a bio with the a blkg - * @bio: target bio - * @blkg: the blkg to associate - * - * This tries to associate @bio with the specified blkg. Association failure - * is handled by walking up the blkg tree. Therefore, the blkg associated can - * be anything between @blkg and the 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. - */ -int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) -{ - if (unlikely(bio->bi_blkg)) - return -EBUSY; - bio->bi_blkg = blkg_tryget_closest(blkg); - return 0; -} - -/** - * __bio_associate_blkg_from_css - internal blkg association function - * - * This in the core association function that all association paths rely on. - * A blkg reference is taken which is released upon freeing of the bio. - */ -static int __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; - int ret; - - rcu_read_lock(); - - if (!css || !css->parent) - blkg = q->root_blkg; - else - blkg = blkg_lookup_create(css_to_blkcg(css), q); - - ret = bio_associate_blkg(bio, blkg); - - rcu_read_unlock(); - return ret; -} - -/** - * 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. This falls back to the queue's root_blkg if - * the association fails with the css. - */ -int bio_associate_blkg_from_css(struct bio *bio, - struct cgroup_subsys_state *css) -{ - if (unlikely(bio->bi_blkg)) - return -EBUSY; - return __bio_associate_blkg_from_css(bio, css); -} -EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css); - #ifdef CONFIG_MEMCG /** - * bio_associate_blkg_from_page - associate a bio with the page's blkg + * bio_associate_blkcg_from_page - associate a bio with the page's blkcg * @bio: target bio * @page: the page to lookup the blkcg from * - * Associate @bio with the blkg from @page's owning memcg and the respective - * request_queue. If cgroup_e_css returns NULL, fall back to the queue's - * root_blkg. - * - * Note: this must be called after bio has an associated device. + * Associate @bio with the blkcg from @page's owning memcg. This works like + * every other associate function wrt references. */ -int bio_associate_blkg_from_page(struct bio *bio, struct page *page) +int bio_associate_blkcg_from_page(struct bio *bio, struct page *page) { - struct cgroup_subsys_state *css; - int ret; + struct cgroup_subsys_state *blkcg_css; - if (unlikely(bio->bi_blkg)) + if (unlikely(bio->bi_css)) return -EBUSY; if (!page->mem_cgroup) return 0; - - rcu_read_lock(); - - css = cgroup_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys); - - ret = __bio_associate_blkg_from_css(bio, css); - - rcu_read_unlock(); - return ret; + blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, + &io_cgrp_subsys); + bio->bi_css = blkcg_css; + return 0; } #endif /* CONFIG_MEMCG */ /** - * bio_associate_create_blkg - associate a bio with a blkg from q - * @q: request_queue where bio is going + * bio_associate_blkcg - associate a bio with the specified blkcg * @bio: target bio + * @blkcg_css: css of the blkcg to associate + * + * Associate @bio with the blkcg specified by @blkcg_css. Block layer will + * treat @bio as if it were issued by a task which belongs to the blkcg. * - * Associate @bio with the blkg found from the bio's css and the request_queue. - * If one is not found, bio_lookup_blkg creates the blkg. This falls back to - * the queue's root_blkg if association fails. + * This function takes an extra reference of @blkcg_css which will be put + * when @bio is released. The caller must own @bio and is responsible for + * synchronizing calls to this function. */ -int bio_associate_create_blkg(struct request_queue *q, struct bio *bio) +int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { - struct cgroup_subsys_state *css; - int ret = 0; - - /* someone has already associated this bio with a blkg */ - if (bio->bi_blkg) - return ret; - - rcu_read_lock(); - - css = blkcg_css(); - - ret = __bio_associate_blkg_from_css(bio, css); - - rcu_read_unlock(); - return ret; + if (unlikely(bio->bi_css)) + return -EBUSY; + css_get(blkcg_css); + bio->bi_css = blkcg_css; + return 0; } +EXPORT_SYMBOL_GPL(bio_associate_blkcg); /** - * bio_reassociate_blkg - reassociate a bio with a blkg from q - * @q: request_queue where bio is going + * bio_associate_blkg - associate a bio with the specified blkg * @bio: target bio + * @blkg: the blkg to associate * - * When submitting a bio, multiple recursive calls to make_request() may occur. - * This causes the initial associate done in blkcg_bio_issue_check() to be - * incorrect and reference the prior request_queue. This performs reassociation - * when this situation happens. + * Associate @bio with the blkg specified by @blkg. This is the queue specific + * blkcg information associated with the @bio, a reference will be taken on the + * @blkg and will be freed when the bio is freed. */ -int bio_reassociate_blkg(struct request_queue *q, struct bio *bio) +int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) { - if (bio->bi_blkg) { - blkg_put(bio->bi_blkg); - bio->bi_blkg = NULL; - } - - return bio_associate_create_blkg(q, bio); + if (unlikely(bio->bi_blkg)) + return -EBUSY; + if (!blkg_try_get(blkg)) + return -ENODEV; + bio->bi_blkg = blkg; + return 0; } /** @@ -2113,6 +2029,10 @@ void bio_disassociate_task(struct bio *bio) put_io_context(bio->bi_ioc); bio->bi_ioc = NULL; } + if (bio->bi_css) { + css_put(bio->bi_css); + bio->bi_css = NULL; + } if (bio->bi_blkg) { blkg_put(bio->bi_blkg); bio->bi_blkg = NULL; @@ -2120,16 +2040,16 @@ void bio_disassociate_task(struct bio *bio) } /** - * bio_clone_blkg_association - clone blkg association from src to dst bio + * bio_clone_blkcg_association - clone blkcg association from src to dst bio * @dst: destination bio * @src: source bio */ -void bio_clone_blkg_association(struct bio *dst, struct bio *src) +void bio_clone_blkcg_association(struct bio *dst, struct bio *src) { - if (src->bi_blkg) - bio_associate_blkg(dst, src->bi_blkg); + if (src->bi_css) + WARN_ON(bio_associate_blkcg(dst, src->bi_css)); } -EXPORT_SYMBOL_GPL(bio_clone_blkg_association); +EXPORT_SYMBOL_GPL(bio_clone_blkcg_association); #endif /* CONFIG_BLK_CGROUP */ static void __init biovec_init_slabs(void) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 992da5592c6e..c630e02836a8 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -84,37 +84,6 @@ static void blkg_free(struct blkcg_gq *blkg) kfree(blkg); } -static void __blkg_release(struct rcu_head *rcu) -{ - struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head); - - percpu_ref_exit(&blkg->refcnt); - - /* release the blkcg and parent blkg refs this blkg has been holding */ - css_put(&blkg->blkcg->css); - if (blkg->parent) - blkg_put(blkg->parent); - - wb_congested_put(blkg->wb_congested); - - blkg_free(blkg); -} - -/* - * A group is RCU protected, but having an rcu lock does not mean that one - * can access all the fields of blkg and assume these are valid. For - * example, don't try to follow throtl_data and request queue links. - * - * Having a reference to blkg under an rcu allows accesses to only values - * local to groups like group stats and group rate limits. - */ -static void blkg_release(struct percpu_ref *ref) -{ - struct blkcg_gq *blkg = container_of(ref, struct blkcg_gq, refcnt); - - call_rcu(&blkg->rcu_head, __blkg_release); -} - /** * blkg_alloc - allocate a blkg * @blkcg: block cgroup the new blkg is associated with @@ -141,6 +110,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q, blkg->q = q; INIT_LIST_HEAD(&blkg->q_node); blkg->blkcg = blkcg; + atomic_set(&blkg->refcnt, 1); /* root blkg uses @q->root_rl, init rl only for !root blkgs */ if (blkcg != &blkcg_root) { @@ -247,11 +217,6 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, blkg_get(blkg->parent); } - ret = percpu_ref_init(&blkg->refcnt, blkg_release, 0, - GFP_NOWAIT | __GFP_NOWARN); - if (ret) - goto err_cancel_ref; - /* invoke per-policy init */ for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkcg_policy *pol = blkcg_policy[i]; @@ -284,8 +249,6 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, blkg_put(blkg); return ERR_PTR(ret); -err_cancel_ref: - percpu_ref_exit(&blkg->refcnt); err_put_congested: wb_congested_put(wb_congested); err_put_css: @@ -296,7 +259,7 @@ err_free_blkg: } /** - * __blkg_lookup_create - lookup blkg, try to create one if not there + * blkg_lookup_create - lookup blkg, try to create one if not there * @blkcg: blkcg of interest * @q: request_queue of interest * @@ -305,11 +268,12 @@ err_free_blkg: * that all non-root blkg's have access to the parent blkg. This function * should be called under RCU read lock and @q->queue_lock. * - * Returns the blkg or the closest blkg if blkg_create fails as it walks - * down from root. + * Returns pointer to the looked up or created blkg on success, ERR_PTR() + * value on error. If @q is dead, returns ERR_PTR(-EINVAL). If @q is not + * dead and bypassing, returns ERR_PTR(-EBUSY). */ -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) { struct blkcg_gq *blkg; @@ -321,7 +285,7 @@ struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, * we shouldn't allow anything to go through for a bypassing queue. */ if (unlikely(blk_queue_bypass(q))) - return q->root_blkg; + return ERR_PTR(blk_queue_dying(q) ? -ENODEV : -EBUSY); blkg = __blkg_lookup(blkcg, q, true); if (blkg) @@ -329,58 +293,23 @@ struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, /* * Create blkgs walking down from blkcg_root to @blkcg, so that all - * non-root blkgs have access to their parents. Returns the closest - * blkg to the intended blkg should blkg_create() fail. + * non-root blkgs have access to their parents. */ while (true) { struct blkcg *pos = blkcg; struct blkcg *parent = blkcg_parent(blkcg); - struct blkcg_gq *ret_blkg = q->root_blkg; - - while (parent) { - blkg = __blkg_lookup(parent, q, false); - if (blkg) { - /* remember closest blkg */ - ret_blkg = blkg; - break; - } + + while (parent && !__blkg_lookup(parent, q, false)) { pos = parent; parent = blkcg_parent(parent); } blkg = blkg_create(pos, q, NULL); - if (IS_ERR(blkg)) - return ret_blkg; - if (pos == blkcg) + if (pos == blkcg || IS_ERR(blkg)) return blkg; } } -/** - * blkg_lookup_create - find or create a blkg - * @blkcg: target block cgroup - * @q: target request_queue - * - * 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, - struct request_queue *q) -{ - struct blkcg_gq *blkg = blkg_lookup(blkcg, q); - unsigned long flags; - - if (unlikely(!blkg)) { - spin_lock_irqsave(q->queue_lock, flags); - - blkg = __blkg_lookup_create(blkcg, q); - - spin_unlock_irqrestore(q->queue_lock, flags); - } - - return blkg; -} - static void blkg_destroy(struct blkcg_gq *blkg) { struct blkcg *blkcg = blkg->blkcg; @@ -424,7 +353,7 @@ static void blkg_destroy(struct blkcg_gq *blkg) * Put the reference taken at the time of creation so that when all * queues are gone, group can be destroyed. */ - percpu_ref_kill(&blkg->refcnt); + blkg_put(blkg); } /** @@ -451,6 +380,29 @@ static void blkg_destroy_all(struct request_queue *q) q->root_rl.blkg = NULL; } +/* + * A group is RCU protected, but having an rcu lock does not mean that one + * can access all the fields of blkg and assume these are valid. For + * example, don't try to follow throtl_data and request queue links. + * + * Having a reference to blkg under an rcu allows accesses to only values + * local to groups like group stats and group rate limits. + */ +void __blkg_release_rcu(struct rcu_head *rcu_head) +{ + struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head); + + /* release the blkcg and parent blkg refs this blkg has been holding */ + css_put(&blkg->blkcg->css); + if (blkg->parent) + blkg_put(blkg->parent); + + wb_congested_put(blkg->wb_congested); + + blkg_free(blkg); +} +EXPORT_SYMBOL_GPL(__blkg_release_rcu); + /* * The next function used by blk_queue_for_each_rl(). It's a bit tricky * because the root blkg uses @q->root_rl instead of its own rl. @@ -1796,7 +1748,8 @@ void blkcg_maybe_throttle_current(void) blkg = blkg_lookup(blkcg, q); if (!blkg) goto out; - if (!blkg_tryget(blkg)) + blkg = blkg_try_get(blkg); + if (!blkg) goto out; rcu_read_unlock(); diff --git a/block/blk-core.c b/block/blk-core.c index 26a5dac80ed9..ce12515f9b9b 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2435,7 +2435,6 @@ blk_qc_t generic_make_request(struct bio *bio) if (q) blk_queue_exit(q); q = bio->bi_disk->queue; - bio_reassociate_blkg(q, bio); flags = 0; if (bio->bi_opf & REQ_NOWAIT) flags = BLK_MQ_REQ_NOWAIT; diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 35c48d7b8f78..bb240a0c1309 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -480,12 +480,34 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio, spinlock_t *lock) { struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos); - struct blkcg_gq *blkg = bio->bi_blkg; + 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(); + blkcg = bio_blkcg(bio); + bio_associate_blkcg(bio, &blkcg->css); + blkg = blkg_lookup(blkcg, q); + if (unlikely(!blkg)) { + if (!lock) + spin_lock_irq(q->queue_lock); + blkg = blkg_lookup_create(blkcg, q); + if (IS_ERR(blkg)) + blkg = NULL; + if (!lock) + spin_unlock_irq(q->queue_lock); + } + if (!blkg) + goto out; + + bio_issue_init(&bio->bi_issue, bio_sectors(bio)); + bio_associate_blkg(bio, blkg); +out: + rcu_read_unlock(); while (blkg && blkg->parent) { struct iolatency_grp *iolat = blkg_to_lat(blkg); if (!iolat) { @@ -706,7 +728,7 @@ static void blkiolatency_timer_fn(struct timer_list *t) * We could be exiting, don't access the pd unless we have a * ref on the blkg. */ - if (!blkg_tryget(blkg)) + if (!blkg_try_get(blkg)) continue; iolat = blkg_to_lat(blkg); diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 4bda70e8db48..db1a3a2ae006 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2115,11 +2115,21 @@ 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) +{ +#ifdef CONFIG_BLK_DEV_THROTTLING_LOW + /* fallback to root_blkg if we fail to get a blkg ref */ + if (bio->bi_css && (bio_associate_blkg(bio, tg_to_blkg(tg)) == -ENODEV)) + bio_associate_blkg(bio, bio->bi_disk->queue->root_blkg); + bio_issue_init(&bio->bi_issue, bio_sectors(bio)); +#endif +} + bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, struct bio *bio) { struct throtl_qnode *qn = NULL; - struct throtl_grp *tg = blkg_to_tg(blkg); + struct throtl_grp *tg = blkg_to_tg(blkg ?: q->root_blkg); struct throtl_service_queue *sq; bool rw = bio_data_dir(bio); bool throttled = false; @@ -2138,6 +2148,7 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, if (unlikely(blk_queue_bypass(q))) goto out_unlock; + blk_throtl_assoc_bio(tg, bio); blk_throtl_update_idletime(tg); sq = &tg->service_queue; diff --git a/block/bounce.c b/block/bounce.c index ec0d99995f5f..418677dcec60 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -276,9 +276,7 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask, } } - bio_clone_blkg_association(bio, bio_src); - - blkcg_bio_issue_init(bio); + bio_clone_blkcg_association(bio, bio_src); return bio; } diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 6a3d87dd3c1a..ed41aa978c4a 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3759,7 +3759,7 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) uint64_t serial_nr; rcu_read_lock(); - serial_nr = __bio_blkcg(bio)->css.serial_nr; + serial_nr = bio_blkcg(bio)->css.serial_nr; rcu_read_unlock(); /* @@ -3824,7 +3824,7 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, struct cfq_group *cfqg; rcu_read_lock(); - cfqg = cfq_lookup_cfqg(cfqd, __bio_blkcg(bio)); + cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio)); if (!cfqg) { cfqq = &cfqd->oom_cfqq; goto out; -- cgit v1.2.3