diff options
Diffstat (limited to 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 2800 |
1 files changed, 1595 insertions, 1205 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 6a789cda68a5..bd8b11c472a2 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -21,77 +21,38 @@ #include <linux/llist.h> #include <linux/cpu.h> #include <linux/cache.h> -#include <linux/sched/sysctl.h> #include <linux/sched/topology.h> #include <linux/sched/signal.h> +#include <linux/suspend.h> #include <linux/delay.h> #include <linux/crash_dump.h> #include <linux/prefetch.h> #include <linux/blk-crypto.h> #include <linux/part_stat.h> +#include <linux/sched/isolation.h> #include <trace/events/block.h> -#include <linux/blk-mq.h> #include <linux/t10-pi.h> #include "blk.h" #include "blk-mq.h" #include "blk-mq-debugfs.h" -#include "blk-mq-tag.h" #include "blk-pm.h" #include "blk-stat.h" #include "blk-mq-sched.h" #include "blk-rq-qos.h" -#include "blk-ioprio.h" static DEFINE_PER_CPU(struct llist_head, blk_cpu_done); +static DEFINE_PER_CPU(call_single_data_t, blk_cpu_csd); +static DEFINE_MUTEX(blk_mq_cpuhp_lock); -static void blk_mq_poll_stats_start(struct request_queue *q); -static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); - -static int blk_mq_poll_stats_bkt(const struct request *rq) -{ - int ddir, sectors, bucket; - - ddir = rq_data_dir(rq); - sectors = blk_rq_stats_sectors(rq); - - bucket = ddir + 2 * ilog2(sectors); - - if (bucket < 0) - return -1; - else if (bucket >= BLK_MQ_POLL_STATS_BKTS) - return ddir + BLK_MQ_POLL_STATS_BKTS - 2; - - return bucket; -} - -#define BLK_QC_T_SHIFT 16 -#define BLK_QC_T_INTERNAL (1U << 31) - -static inline struct blk_mq_hw_ctx *blk_qc_to_hctx(struct request_queue *q, - blk_qc_t qc) -{ - return xa_load(&q->hctx_table, - (qc & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT); -} - -static inline struct request *blk_qc_to_rq(struct blk_mq_hw_ctx *hctx, - blk_qc_t qc) -{ - unsigned int tag = qc & ((1U << BLK_QC_T_SHIFT) - 1); - - if (qc & BLK_QC_T_INTERNAL) - return blk_mq_tag_to_rq(hctx->sched_tags, tag); - return blk_mq_tag_to_rq(hctx->tags, tag); -} - -static inline blk_qc_t blk_rq_to_qc(struct request *rq) -{ - return (rq->mq_hctx->queue_num << BLK_QC_T_SHIFT) | - (rq->tag != -1 ? - rq->tag : (rq->internal_tag | BLK_QC_T_INTERNAL)); -} +static void blk_mq_insert_request(struct request *rq, blk_insert_t flags); +static void blk_mq_request_bypass_insert(struct request *rq, + blk_insert_t flags); +static void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, + struct list_head *list); +static int blk_hctx_poll(struct request_queue *q, struct blk_mq_hw_ctx *hctx, + struct io_comp_batch *iob, unsigned int flags); /* * Check if any of the ctx, dispatch list or elevator @@ -129,41 +90,83 @@ struct mq_inflight { unsigned int inflight[2]; }; -static bool blk_mq_check_inflight(struct request *rq, void *priv) +static bool blk_mq_check_in_driver(struct request *rq, void *priv) { struct mq_inflight *mi = priv; - if (rq->part && blk_do_io_stat(rq) && - (!mi->part->bd_partno || rq->part == mi->part) && + if (rq->rq_flags & RQF_IO_STAT && + (!bdev_is_partition(mi->part) || rq->part == mi->part) && blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) mi->inflight[rq_data_dir(rq)]++; return true; } -unsigned int blk_mq_in_flight(struct request_queue *q, - struct block_device *part) +void blk_mq_in_driver_rw(struct block_device *part, unsigned int inflight[2]) { struct mq_inflight mi = { .part = part }; - blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); + blk_mq_queue_tag_busy_iter(bdev_get_queue(part), blk_mq_check_in_driver, + &mi); + inflight[READ] = mi.inflight[READ]; + inflight[WRITE] = mi.inflight[WRITE]; +} + +#ifdef CONFIG_LOCKDEP +static bool blk_freeze_set_owner(struct request_queue *q, + struct task_struct *owner) +{ + if (!owner) + return false; + + if (!q->mq_freeze_depth) { + q->mq_freeze_owner = owner; + q->mq_freeze_owner_depth = 1; + q->mq_freeze_disk_dead = !q->disk || + test_bit(GD_DEAD, &q->disk->state) || + !blk_queue_registered(q); + q->mq_freeze_queue_dying = blk_queue_dying(q); + return true; + } - return mi.inflight[0] + mi.inflight[1]; + if (owner == q->mq_freeze_owner) + q->mq_freeze_owner_depth += 1; + return false; } -void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part, - unsigned int inflight[2]) +/* verify the last unfreeze in owner context */ +static bool blk_unfreeze_check_owner(struct request_queue *q) { - struct mq_inflight mi = { .part = part }; + if (q->mq_freeze_owner != current) + return false; + if (--q->mq_freeze_owner_depth == 0) { + q->mq_freeze_owner = NULL; + return true; + } + return false; +} - blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); - inflight[0] = mi.inflight[0]; - inflight[1] = mi.inflight[1]; +#else + +static bool blk_freeze_set_owner(struct request_queue *q, + struct task_struct *owner) +{ + return false; } -void blk_freeze_queue_start(struct request_queue *q) +static bool blk_unfreeze_check_owner(struct request_queue *q) +{ + return false; +} +#endif + +bool __blk_freeze_queue_start(struct request_queue *q, + struct task_struct *owner) { + bool freeze; + mutex_lock(&q->mq_freeze_lock); + freeze = blk_freeze_set_owner(q, owner); if (++q->mq_freeze_depth == 1) { percpu_ref_kill(&q->q_usage_counter); mutex_unlock(&q->mq_freeze_lock); @@ -172,6 +175,14 @@ void blk_freeze_queue_start(struct request_queue *q) } else { mutex_unlock(&q->mq_freeze_lock); } + + return freeze; +} + +void blk_freeze_queue_start(struct request_queue *q) +{ + if (__blk_freeze_queue_start(q, current)) + blk_freeze_acquire_lock(q); } EXPORT_SYMBOL_GPL(blk_freeze_queue_start); @@ -190,35 +201,17 @@ int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, } EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); -/* - * Guarantee no request is in use, so we can change any data structure of - * the queue afterward. - */ -void blk_freeze_queue(struct request_queue *q) +void blk_mq_freeze_queue_nomemsave(struct request_queue *q) { - /* - * In the !blk_mq case we are only calling this to kill the - * q_usage_counter, otherwise this increases the freeze depth - * and waits for it to return to zero. For this reason there is - * no blk_unfreeze_queue(), and blk_freeze_queue() is not - * exported to drivers as the only user for unfreeze is blk_mq. - */ blk_freeze_queue_start(q); blk_mq_freeze_queue_wait(q); } +EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_nomemsave); -void blk_mq_freeze_queue(struct request_queue *q) +bool __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) { - /* - * ...just an alias to keep freeze and unfreeze actions balanced - * in the blk_mq_* namespace - */ - blk_freeze_queue(q); -} -EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); + bool unfreeze; -void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) -{ mutex_lock(&q->mq_freeze_lock); if (force_atomic) q->q_usage_counter.data->force_atomic = true; @@ -228,14 +221,38 @@ void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) percpu_ref_resurrect(&q->q_usage_counter); wake_up_all(&q->mq_freeze_wq); } + unfreeze = blk_unfreeze_check_owner(q); mutex_unlock(&q->mq_freeze_lock); + + return unfreeze; } -void blk_mq_unfreeze_queue(struct request_queue *q) +void blk_mq_unfreeze_queue_nomemrestore(struct request_queue *q) +{ + if (__blk_mq_unfreeze_queue(q, false)) + blk_unfreeze_release_lock(q); +} +EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue_nomemrestore); + +/* + * non_owner variant of blk_freeze_queue_start + * + * Unlike blk_freeze_queue_start, the queue doesn't need to be unfrozen + * by the same task. This is fragile and should not be used if at all + * possible. + */ +void blk_freeze_queue_start_non_owner(struct request_queue *q) +{ + __blk_freeze_queue_start(q, NULL); +} +EXPORT_SYMBOL_GPL(blk_freeze_queue_start_non_owner); + +/* non_owner variant of blk_mq_unfreeze_queue */ +void blk_mq_unfreeze_queue_non_owner(struct request_queue *q) { __blk_mq_unfreeze_queue(q, false); } -EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); +EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue_non_owner); /* * FIXME: replace the scsi_internal_device_*block_nowait() calls in the @@ -254,15 +271,17 @@ EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait); /** * blk_mq_wait_quiesce_done() - wait until in-progress quiesce is done - * @q: request queue. + * @set: tag_set to wait on * * Note: it is driver's responsibility for making sure that quiesce has - * been started. + * been started on or more of the request_queues of the tag_set. This + * function only waits for the quiesce on those request_queues that had + * the quiesce flag set using blk_mq_quiesce_queue_nowait. */ -void blk_mq_wait_quiesce_done(struct request_queue *q) +void blk_mq_wait_quiesce_done(struct blk_mq_tag_set *set) { - if (blk_queue_has_srcu(q)) - synchronize_srcu(q->srcu); + if (set->flags & BLK_MQ_F_BLOCKING) + synchronize_srcu(set->srcu); else synchronize_rcu(); } @@ -280,7 +299,9 @@ EXPORT_SYMBOL_GPL(blk_mq_wait_quiesce_done); void blk_mq_quiesce_queue(struct request_queue *q) { blk_mq_quiesce_queue_nowait(q); - blk_mq_wait_quiesce_done(q); + /* nothing to wait for non-mq queues */ + if (queue_is_mq(q)) + blk_mq_wait_quiesce_done(q->tag_set); } EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); @@ -311,6 +332,34 @@ void blk_mq_unquiesce_queue(struct request_queue *q) } EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue); +void blk_mq_quiesce_tagset(struct blk_mq_tag_set *set) +{ + struct request_queue *q; + + mutex_lock(&set->tag_list_lock); + list_for_each_entry(q, &set->tag_list, tag_set_list) { + if (!blk_queue_skip_tagset_quiesce(q)) + blk_mq_quiesce_queue_nowait(q); + } + mutex_unlock(&set->tag_list_lock); + + blk_mq_wait_quiesce_done(set); +} +EXPORT_SYMBOL_GPL(blk_mq_quiesce_tagset); + +void blk_mq_unquiesce_tagset(struct blk_mq_tag_set *set) +{ + struct request_queue *q; + + mutex_lock(&set->tag_list_lock); + list_for_each_entry(q, &set->tag_list, tag_set_list) { + if (!blk_queue_skip_tagset_quiesce(q)) + blk_mq_unquiesce_queue(q); + } + mutex_unlock(&set->tag_list_lock); +} +EXPORT_SYMBOL_GPL(blk_mq_unquiesce_tagset); + void blk_mq_wake_waiters(struct request_queue *q) { struct blk_mq_hw_ctx *hctx; @@ -328,18 +377,38 @@ void blk_rq_init(struct request_queue *q, struct request *rq) INIT_LIST_HEAD(&rq->queuelist); rq->q = q; rq->__sector = (sector_t) -1; + rq->phys_gap_bit = 0; INIT_HLIST_NODE(&rq->hash); RB_CLEAR_NODE(&rq->rb_node); rq->tag = BLK_MQ_NO_TAG; rq->internal_tag = BLK_MQ_NO_TAG; - rq->start_time_ns = ktime_get_ns(); - rq->part = NULL; + rq->start_time_ns = blk_time_get_ns(); blk_crypto_rq_set_defaults(rq); } EXPORT_SYMBOL(blk_rq_init); +/* Set start and alloc time when the allocated request is actually used */ +static inline void blk_mq_rq_time_init(struct request *rq, u64 alloc_time_ns) +{ +#ifdef CONFIG_BLK_RQ_ALLOC_TIME + if (blk_queue_rq_alloc_time(rq->q)) + rq->alloc_time_ns = alloc_time_ns; + else + rq->alloc_time_ns = 0; +#endif +} + +static inline void blk_mq_bio_issue_init(struct request_queue *q, + struct bio *bio) +{ +#ifdef CONFIG_BLK_CGROUP + if (test_bit(QUEUE_FLAG_BIO_ISSUE_TIME, &q->queue_flags)) + bio->issue_time_ns = blk_time_get_ns(); +#endif +} + static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, - struct blk_mq_tags *tags, unsigned int tag, u64 alloc_time_ns) + struct blk_mq_tags *tags, unsigned int tag) { struct blk_mq_ctx *ctx = data->ctx; struct blk_mq_hw_ctx *hctx = data->hctx; @@ -353,33 +422,22 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, if (data->flags & BLK_MQ_REQ_PM) data->rq_flags |= RQF_PM; - if (blk_queue_io_stat(q)) - data->rq_flags |= RQF_IO_STAT; rq->rq_flags = data->rq_flags; - if (!(data->rq_flags & RQF_ELV)) { - rq->tag = tag; - rq->internal_tag = BLK_MQ_NO_TAG; - } else { + if (data->rq_flags & RQF_SCHED_TAGS) { rq->tag = BLK_MQ_NO_TAG; rq->internal_tag = tag; + } else { + rq->tag = tag; + rq->internal_tag = BLK_MQ_NO_TAG; } rq->timeout = 0; - if (blk_mq_need_time_stamp(rq)) - rq->start_time_ns = ktime_get_ns(); - else - rq->start_time_ns = 0; rq->part = NULL; -#ifdef CONFIG_BLK_RQ_ALLOC_TIME - rq->alloc_time_ns = alloc_time_ns; -#endif rq->io_start_time_ns = 0; rq->stats_sectors = 0; rq->nr_phys_segments = 0; -#if defined(CONFIG_BLK_DEV_INTEGRITY) rq->nr_integrity_segments = 0; -#endif rq->end_io = NULL; rq->end_io_data = NULL; @@ -389,25 +447,21 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, WRITE_ONCE(rq->deadline, 0); req_ref_set(rq, 1); - if (rq->rq_flags & RQF_ELV) { + if (rq->rq_flags & RQF_USE_SCHED) { struct elevator_queue *e = data->q->elevator; INIT_HLIST_NODE(&rq->hash); RB_CLEAR_NODE(&rq->rb_node); - if (!op_is_flush(data->cmd_flags) && - e->type->ops.prepare_request) { + if (e->type->ops.prepare_request) e->type->ops.prepare_request(rq); - rq->rq_flags |= RQF_ELVPRIV; - } } return rq; } static inline struct request * -__blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data, - u64 alloc_time_ns) +__blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data) { unsigned int tag, tag_offset; struct blk_mq_tags *tags; @@ -415,26 +469,33 @@ __blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data, unsigned long tag_mask; int i, nr = 0; - tag_mask = blk_mq_get_tags(data, data->nr_tags, &tag_offset); - if (unlikely(!tag_mask)) - return NULL; + do { + tag_mask = blk_mq_get_tags(data, data->nr_tags - nr, &tag_offset); + if (unlikely(!tag_mask)) { + if (nr == 0) + return NULL; + break; + } + tags = blk_mq_tags_from_data(data); + for (i = 0; tag_mask; i++) { + if (!(tag_mask & (1UL << i))) + continue; + tag = tag_offset + i; + prefetch(tags->static_rqs[tag]); + tag_mask &= ~(1UL << i); + rq = blk_mq_rq_ctx_init(data, tags, tag); + rq_list_add_head(data->cached_rqs, rq); + nr++; + } + } while (data->nr_tags > nr); - tags = blk_mq_tags_from_data(data); - for (i = 0; tag_mask; i++) { - if (!(tag_mask & (1UL << i))) - continue; - tag = tag_offset + i; - prefetch(tags->static_rqs[tag]); - tag_mask &= ~(1UL << i); - rq = blk_mq_rq_ctx_init(data, tags, tag, alloc_time_ns); - rq_list_add(data->cached_rq, rq); - nr++; - } + if (!(data->rq_flags & RQF_SCHED_TAGS)) + blk_mq_add_active_requests(data->hctx, nr); /* caller already holds a reference, add for remainder */ percpu_ref_get_many(&data->q->q_usage_counter, nr - 1); data->nr_tags -= nr; - return rq_list_pop(data->cached_rq); + return rq_list_pop(data->cached_rqs); } static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) @@ -446,33 +507,39 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) /* alloc_time includes depth and tag waits */ if (blk_queue_rq_alloc_time(q)) - alloc_time_ns = ktime_get_ns(); + alloc_time_ns = blk_time_get_ns(); if (data->cmd_flags & REQ_NOWAIT) data->flags |= BLK_MQ_REQ_NOWAIT; - if (q->elevator) { - struct elevator_queue *e = q->elevator; +retry: + data->ctx = blk_mq_get_ctx(q); + data->hctx = blk_mq_map_queue(data->cmd_flags, data->ctx); - data->rq_flags |= RQF_ELV; + if (q->elevator) { + /* + * All requests use scheduler tags when an I/O scheduler is + * enabled for the queue. + */ + data->rq_flags |= RQF_SCHED_TAGS; /* * Flush/passthrough requests are special and go directly to the - * dispatch list. Don't include reserved tags in the - * limiting, as it isn't useful. + * dispatch list. */ - if (!op_is_flush(data->cmd_flags) && - !blk_op_is_passthrough(data->cmd_flags) && - e->type->ops.limit_depth && - !(data->flags & BLK_MQ_REQ_RESERVED)) - e->type->ops.limit_depth(data->cmd_flags, data); - } + if ((data->cmd_flags & REQ_OP_MASK) != REQ_OP_FLUSH && + !blk_op_is_passthrough(data->cmd_flags)) { + struct elevator_mq_ops *ops = &q->elevator->type->ops; -retry: - data->ctx = blk_mq_get_ctx(q); - data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx); - if (!(data->rq_flags & RQF_ELV)) + WARN_ON_ONCE(data->flags & BLK_MQ_REQ_RESERVED); + + data->rq_flags |= RQF_USE_SCHED; + if (ops->limit_depth) + ops->limit_depth(data->cmd_flags, data); + } + } else { blk_mq_tag_busy(data->hctx); + } if (data->flags & BLK_MQ_REQ_RESERVED) data->rq_flags |= RQF_RESV; @@ -481,9 +548,11 @@ retry: * Try batched alloc if we want more than 1 tag. */ if (data->nr_tags > 1) { - rq = __blk_mq_alloc_requests_batch(data, alloc_time_ns); - if (rq) + rq = __blk_mq_alloc_requests_batch(data); + if (rq) { + blk_mq_rq_time_init(rq, alloc_time_ns); return rq; + } data->nr_tags = 1; } @@ -506,8 +575,11 @@ retry: goto retry; } - return blk_mq_rq_ctx_init(data, blk_mq_tags_from_data(data), tag, - alloc_time_ns); + if (!(data->rq_flags & RQF_SCHED_TAGS)) + blk_mq_inc_active_requests(data->hctx); + rq = blk_mq_rq_ctx_init(data, blk_mq_tags_from_data(data), tag); + blk_mq_rq_time_init(rq, alloc_time_ns); + return rq; } static struct request *blk_mq_rq_cache_fill(struct request_queue *q, @@ -518,9 +590,13 @@ static struct request *blk_mq_rq_cache_fill(struct request_queue *q, struct blk_mq_alloc_data data = { .q = q, .flags = flags, + .shallow_depth = 0, .cmd_flags = opf, + .rq_flags = 0, .nr_tags = plug->nr_ios, - .cached_rq = &plug->cached_rq, + .cached_rqs = &plug->cached_rqs, + .ctx = NULL, + .hctx = NULL }; struct request *rq; @@ -544,25 +620,27 @@ static struct request *blk_mq_alloc_cached_request(struct request_queue *q, if (!plug) return NULL; - if (rq_list_empty(plug->cached_rq)) { + + if (rq_list_empty(&plug->cached_rqs)) { if (plug->nr_ios == 1) return NULL; rq = blk_mq_rq_cache_fill(q, plug, opf, flags); - if (rq) - goto got_it; - return NULL; - } - rq = rq_list_peek(&plug->cached_rq); - if (!rq || rq->q != q) - return NULL; + if (!rq) + return NULL; + } else { + rq = rq_list_peek(&plug->cached_rqs); + if (!rq || rq->q != q) + return NULL; - if (blk_mq_get_hctx_type(opf) != rq->mq_hctx->type) - return NULL; - if (op_is_flush(rq->cmd_flags) != op_is_flush(opf)) - return NULL; + if (blk_mq_get_hctx_type(opf) != rq->mq_hctx->type) + return NULL; + if (op_is_flush(rq->cmd_flags) != op_is_flush(opf)) + return NULL; + + rq_list_pop(&plug->cached_rqs); + blk_mq_rq_time_init(rq, blk_time_get_ns()); + } - plug->cached_rq = rq_list_next(rq); -got_it: rq->cmd_flags = opf; INIT_LIST_HEAD(&rq->queuelist); return rq; @@ -578,8 +656,13 @@ struct request *blk_mq_alloc_request(struct request_queue *q, blk_opf_t opf, struct blk_mq_alloc_data data = { .q = q, .flags = flags, + .shallow_depth = 0, .cmd_flags = opf, + .rq_flags = 0, .nr_tags = 1, + .cached_rqs = NULL, + .ctx = NULL, + .hctx = NULL }; int ret; @@ -592,6 +675,7 @@ struct request *blk_mq_alloc_request(struct request_queue *q, blk_opf_t opf, goto out_queue_exit; } rq->__data_len = 0; + rq->phys_gap_bit = 0; rq->__sector = (sector_t) -1; rq->bio = rq->biotail = NULL; return rq; @@ -607,8 +691,13 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, struct blk_mq_alloc_data data = { .q = q, .flags = flags, + .shallow_depth = 0, .cmd_flags = opf, + .rq_flags = 0, .nr_tags = 1, + .cached_rqs = NULL, + .ctx = NULL, + .hctx = NULL }; u64 alloc_time_ns = 0; struct request *rq; @@ -618,7 +707,7 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, /* alloc_time includes depth and tag waits */ if (blk_queue_rq_alloc_time(q)) - alloc_time_ns = ktime_get_ns(); + alloc_time_ns = blk_time_get_ns(); /* * If the tag allocator sleeps we could get an allocation for a @@ -626,7 +715,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, * allocator for this for the rare use case of a command tied to * a specific queue. */ - if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED)))) + if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)) || + WARN_ON_ONCE(!(flags & BLK_MQ_REQ_RESERVED))) return ERR_PTR(-EINVAL); if (hctx_idx >= q->nr_hw_queues) @@ -641,7 +731,7 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, * If not tell the caller that it should skip this queue. */ ret = -EXDEV; - data.hctx = xa_load(&q->hctx_table, hctx_idx); + data.hctx = q->queue_hw_ctx[hctx_idx]; if (!blk_mq_hw_queue_mapped(data.hctx)) goto out_queue_exit; cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask); @@ -649,10 +739,10 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, goto out_queue_exit; data.ctx = __blk_mq_get_ctx(q, cpu); - if (!q->elevator) - blk_mq_tag_busy(data.hctx); + if (q->elevator) + data.rq_flags |= RQF_SCHED_TAGS; else - data.rq_flags |= RQF_ELV; + blk_mq_tag_busy(data.hctx); if (flags & BLK_MQ_REQ_RESERVED) data.rq_flags |= RQF_RESV; @@ -661,9 +751,12 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, tag = blk_mq_get_tag(&data); if (tag == BLK_MQ_NO_TAG) goto out_queue_exit; - rq = blk_mq_rq_ctx_init(&data, blk_mq_tags_from_data(&data), tag, - alloc_time_ns); + if (!(data.rq_flags & RQF_SCHED_TAGS)) + blk_mq_inc_active_requests(data.hctx); + rq = blk_mq_rq_ctx_init(&data, blk_mq_tags_from_data(&data), tag); + blk_mq_rq_time_init(rq, alloc_time_ns); rq->__data_len = 0; + rq->phys_gap_bit = 0; rq->__sector = (sector_t) -1; rq->bio = rq->biotail = NULL; return rq; @@ -674,6 +767,23 @@ out_queue_exit: } EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); +static void blk_mq_finish_request(struct request *rq) +{ + struct request_queue *q = rq->q; + + blk_zone_finish_request(rq); + + if (rq->rq_flags & RQF_USE_SCHED) { + q->elevator->type->ops.finish_request(rq); + /* + * For postflush request that may need to be + * completed twice, we should clear this flag + * to avoid double finish_request() on the rq. + */ + rq->rq_flags &= ~RQF_USE_SCHED; + } +} + static void __blk_mq_free_request(struct request *rq) { struct request_queue *q = rq->q; @@ -684,8 +794,11 @@ static void __blk_mq_free_request(struct request *rq) blk_crypto_free_request(rq); blk_pm_mark_last_busy(rq); rq->mq_hctx = NULL; - if (rq->tag != BLK_MQ_NO_TAG) + + if (rq->tag != BLK_MQ_NO_TAG) { + blk_mq_dec_active_requests(hctx); blk_mq_put_tag(hctx->tags, ctx, rq->tag); + } if (sched_tag != BLK_MQ_NO_TAG) blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag); blk_mq_sched_restart(hctx); @@ -695,14 +808,8 @@ static void __blk_mq_free_request(struct request *rq) void blk_mq_free_request(struct request *rq) { struct request_queue *q = rq->q; - struct blk_mq_hw_ctx *hctx = rq->mq_hctx; - - if ((rq->rq_flags & RQF_ELVPRIV) && - q->elevator->type->ops.finish_request) - q->elevator->type->ops.finish_request(rq); - if (rq->rq_flags & RQF_MQ_INFLIGHT) - __blk_mq_dec_active_requests(hctx); + blk_mq_finish_request(rq); if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) laptop_io_completion(q->disk->bdi); @@ -719,7 +826,7 @@ void blk_mq_free_plug_rqs(struct blk_plug *plug) { struct request *rq; - while ((rq = rq_list_pop(&plug->cached_rq)) != NULL) + while ((rq = rq_list_pop(&plug->cached_rqs)) != NULL) blk_mq_free_request(rq); } @@ -737,34 +844,9 @@ void blk_dump_rq_flags(struct request *rq, char *msg) } EXPORT_SYMBOL(blk_dump_rq_flags); -static void req_bio_endio(struct request *rq, struct bio *bio, - unsigned int nbytes, blk_status_t error) -{ - if (unlikely(error)) { - bio->bi_status = error; - } else if (req_op(rq) == REQ_OP_ZONE_APPEND) { - /* - * Partial zone append completions cannot be supported as the - * BIO fragments may end up not being written sequentially. - */ - if (bio->bi_iter.bi_size != nbytes) - bio->bi_status = BLK_STS_IOERR; - else - bio->bi_iter.bi_sector = rq->__sector; - } - - bio_advance(bio, nbytes); - - if (unlikely(rq->rq_flags & RQF_QUIET)) - bio_set_flag(bio, BIO_QUIET); - /* don't actually finish bio if it's part of flush sequence */ - if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ)) - bio_endio(bio); -} - static void blk_account_io_completion(struct request *req, unsigned int bytes) { - if (req->part && blk_do_io_stat(req)) { + if (req->rq_flags & RQF_IO_STAT) { const int sgrp = op_stat_group(req_op(req)); part_stat_lock(); @@ -784,7 +866,7 @@ static void blk_print_req_error(struct request *req, blk_status_t status) blk_op_str(req_op(req)), (__force u32)(req->cmd_flags & ~REQ_OP_MASK), req->nr_phys_segments, - IOPRIO_PRIO_CLASS(req->ioprio)); + IOPRIO_PRIO_CLASS(req_get_ioprio(req))); } /* @@ -802,10 +884,14 @@ static void blk_complete_request(struct request *req) if (!bio) return; -#ifdef CONFIG_BLK_DEV_INTEGRITY if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ) - req->q->integrity.profile->complete_fn(req, total_bytes); -#endif + blk_integrity_complete(req, total_bytes); + + /* + * Upper layers may call blk_crypto_evict_key() anytime after the last + * bio_endio(). Therefore, the keyslot must be released before that. + */ + blk_crypto_rq_put_keyslot(req); blk_account_io_completion(req, total_bytes); @@ -815,8 +901,8 @@ static void blk_complete_request(struct request *req) /* Completion has already been traced */ bio_clear_flag(bio, BIO_TRACE_COMPLETION); - if (req_op(req) == REQ_OP_ZONE_APPEND) - bio->bi_iter.bi_sector = req->__sector; + if (blk_req_bio_is_zone_append(req, bio)) + blk_zone_append_update_request_bio(req, bio); if (!is_flush) bio_endio(bio); @@ -859,6 +945,8 @@ static void blk_complete_request(struct request *req) bool blk_update_request(struct request *req, blk_status_t error, unsigned int nr_bytes) { + bool is_flush = req->rq_flags & RQF_FLUSH_SEQ; + bool quiet = req->rq_flags & RQF_QUIET; int total_bytes; trace_block_rq_complete(req, error, nr_bytes); @@ -866,15 +954,19 @@ bool blk_update_request(struct request *req, blk_status_t error, if (!req->bio) return false; -#ifdef CONFIG_BLK_DEV_INTEGRITY if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ && error == BLK_STS_OK) - req->q->integrity.profile->complete_fn(req, nr_bytes); -#endif + blk_integrity_complete(req, nr_bytes); + + /* + * Upper layers may call blk_crypto_evict_key() anytime after the last + * bio_endio(). Therefore, the keyslot must be released before that. + */ + if (blk_crypto_rq_has_keyslot(req) && nr_bytes >= blk_rq_bytes(req)) + __blk_crypto_rq_put_keyslot(req); - if (unlikely(error && !blk_rq_is_passthrough(req) && - !(req->rq_flags & RQF_QUIET)) && - !test_bit(GD_DEAD, &req->q->disk->state)) { + if (unlikely(error && !blk_rq_is_passthrough(req) && !quiet) && + !test_bit(GD_DEAD, &req->q->disk->state)) { blk_print_req_error(req, error); trace_block_rq_error(req, error, nr_bytes); } @@ -886,12 +978,34 @@ bool blk_update_request(struct request *req, blk_status_t error, struct bio *bio = req->bio; unsigned bio_bytes = min(bio->bi_iter.bi_size, nr_bytes); - if (bio_bytes == bio->bi_iter.bi_size) + if (unlikely(error)) + bio->bi_status = error; + + if (bio_bytes == bio->bi_iter.bi_size) { req->bio = bio->bi_next; + } else if (bio_is_zone_append(bio) && error == BLK_STS_OK) { + /* + * Partial zone append completions cannot be supported + * as the BIO fragments may end up not being written + * sequentially. + */ + bio->bi_status = BLK_STS_IOERR; + } /* Completion has already been traced */ bio_clear_flag(bio, BIO_TRACE_COMPLETION); - req_bio_endio(req, bio, bio_bytes, error); + if (unlikely(quiet)) + bio_set_flag(bio, BIO_QUIET); + + bio_advance(bio, bio_bytes); + + /* Don't actually finish bio if it's part of flush sequence */ + if (!bio->bi_iter.bi_size) { + if (blk_req_bio_is_zone_append(req, bio)) + blk_zone_append_update_request_bio(req, bio); + if (!is_flush) + bio_endio(bio); + } total_bytes += bio_bytes; nr_bytes -= bio_bytes; @@ -943,59 +1057,91 @@ bool blk_update_request(struct request *req, blk_status_t error, } EXPORT_SYMBOL_GPL(blk_update_request); -static void __blk_account_io_done(struct request *req, u64 now) -{ - const int sgrp = op_stat_group(req_op(req)); - - part_stat_lock(); - update_io_ticks(req->part, jiffies, true); - part_stat_inc(req->part, ios[sgrp]); - part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns); - part_stat_unlock(); -} - static inline void blk_account_io_done(struct request *req, u64 now) { + trace_block_io_done(req); + /* * Account IO completion. flush_rq isn't accounted as a * normal IO on queueing nor completion. Accounting the * containing request is enough. */ - if (blk_do_io_stat(req) && req->part && - !(req->rq_flags & RQF_FLUSH_SEQ)) - __blk_account_io_done(req, now); + if ((req->rq_flags & (RQF_IO_STAT|RQF_FLUSH_SEQ)) == RQF_IO_STAT) { + const int sgrp = op_stat_group(req_op(req)); + + part_stat_lock(); + update_io_ticks(req->part, jiffies, true); + part_stat_inc(req->part, ios[sgrp]); + part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns); + part_stat_local_dec(req->part, + in_flight[op_is_write(req_op(req))]); + part_stat_unlock(); + } +} + +static inline bool blk_rq_passthrough_stats(struct request *req) +{ + struct bio *bio = req->bio; + + if (!blk_queue_passthrough_stat(req->q)) + return false; + + /* Requests without a bio do not transfer data. */ + if (!bio) + return false; + + /* + * Stats are accumulated in the bdev, so must have one attached to a + * bio to track stats. Most drivers do not set the bdev for passthrough + * requests, but nvme is one that will set it. + */ + if (!bio->bi_bdev) + return false; + + /* + * We don't know what a passthrough command does, but we know the + * payload size and data direction. Ensuring the size is aligned to the + * block size filters out most commands with payloads that don't + * represent sector access. + */ + if (blk_rq_bytes(req) & (bdev_logical_block_size(bio->bi_bdev) - 1)) + return false; + return true; } -static void __blk_account_io_start(struct request *rq) +static inline void blk_account_io_start(struct request *req) { + trace_block_io_start(req); + + if (!blk_queue_io_stat(req->q)) + return; + if (blk_rq_is_passthrough(req) && !blk_rq_passthrough_stats(req)) + return; + + req->rq_flags |= RQF_IO_STAT; + req->start_time_ns = blk_time_get_ns(); + /* * All non-passthrough requests are created from a bio with one * exception: when a flush command that is part of a flush sequence * generated by the state machine in blk-flush.c is cloned onto the * lower device by dm-multipath we can get here without a bio. */ - if (rq->bio) - rq->part = rq->bio->bi_bdev; + if (req->bio) + req->part = req->bio->bi_bdev; else - rq->part = rq->q->disk->part0; + req->part = req->q->disk->part0; part_stat_lock(); - update_io_ticks(rq->part, jiffies, false); + update_io_ticks(req->part, jiffies, false); + part_stat_local_inc(req->part, in_flight[op_is_write(req_op(req))]); part_stat_unlock(); } -static inline void blk_account_io_start(struct request *req) -{ - if (blk_do_io_stat(req)) - __blk_account_io_start(req); -} - static inline void __blk_mq_end_request_acct(struct request *rq, u64 now) { - if (rq->rq_flags & RQF_STATS) { - blk_mq_poll_stats_start(rq->q); + if (rq->rq_flags & RQF_STATS) blk_stat_add(rq, now); - } blk_mq_sched_completed_request(rq, now); blk_account_io_done(rq, now); @@ -1004,7 +1150,9 @@ static inline void __blk_mq_end_request_acct(struct request *rq, u64 now) inline void __blk_mq_end_request(struct request *rq, blk_status_t error) { if (blk_mq_need_time_stamp(rq)) - __blk_mq_end_request_acct(rq, ktime_get_ns()); + __blk_mq_end_request_acct(rq, blk_time_get_ns()); + + blk_mq_finish_request(rq); if (rq->end_io) { rq_qos_done(rq->q, rq); @@ -1031,12 +1179,7 @@ static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx, { struct request_queue *q = hctx->queue; - /* - * All requests should have been marked as RQF_MQ_INFLIGHT, so - * update hctx->nr_active in batch - */ - if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) - __blk_mq_sub_active_requests(hctx, nr_tags); + blk_mq_sub_active_requests(hctx, nr_tags); blk_mq_put_tags(hctx->tags, tag_array, nr_tags); percpu_ref_put_many(&q->q_usage_counter, nr_tags); @@ -1050,7 +1193,7 @@ void blk_mq_end_request_batch(struct io_comp_batch *iob) u64 now = 0; if (iob->need_ts) - now = ktime_get_ns(); + now = blk_time_get_ns(); while ((rq = rq_list_pop(&iob->req_list)) != NULL) { prefetch(rq->bio); @@ -1060,6 +1203,8 @@ void blk_mq_end_request_batch(struct io_comp_batch *iob) if (iob->need_ts) __blk_mq_end_request_acct(rq, now); + blk_mq_finish_request(rq); + rq_qos_done(rq->q, rq); /* @@ -1099,7 +1244,7 @@ static void blk_complete_reqs(struct llist_head *list) rq->q->mq_ops->complete(rq); } -static __latent_entropy void blk_done_softirq(struct softirq_action *h) +static __latent_entropy void blk_done_softirq(void) { blk_complete_reqs(this_cpu_ptr(&blk_cpu_done)); } @@ -1131,10 +1276,11 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq) if (force_irqthreads()) return false; - /* same CPU or cache domain? Complete locally */ + /* same CPU or cache domain and capacity? Complete locally */ if (cpu == rq->mq_ctx->cpu || (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) && - cpus_share_cache(cpu, rq->mq_ctx->cpu))) + cpus_share_cache(cpu, rq->mq_ctx->cpu) && + cpus_equal_capacity(cpu, rq->mq_ctx->cpu))) return false; /* don't try to IPI to an offline CPU */ @@ -1143,15 +1289,11 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq) static void blk_mq_complete_send_ipi(struct request *rq) { - struct llist_head *list; unsigned int cpu; cpu = rq->mq_ctx->cpu; - list = &per_cpu(blk_cpu_done, cpu); - if (llist_add(&rq->ipi_list, list)) { - INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq); - smp_call_function_single_async(cpu, &rq->csd); - } + if (llist_add(&rq->ipi_list, &per_cpu(blk_cpu_done, cpu))) + smp_call_function_single_async(cpu, &per_cpu(blk_cpu_csd, cpu)); } static void blk_mq_raise_softirq(struct request *rq) @@ -1174,8 +1316,9 @@ bool blk_mq_complete_request_remote(struct request *rq) * or a polled request, always complete locally, * it's pointless to redirect the completion. */ - if (rq->mq_hctx->nr_ctx == 1 || - rq->cmd_flags & REQ_POLLED) + if ((rq->mq_hctx->nr_ctx == 1 && + rq->mq_ctx->cpu == raw_smp_processor_id()) || + rq->cmd_flags & REQ_POLLED) return false; if (blk_mq_complete_need_ipi(rq)) { @@ -1219,8 +1362,9 @@ void blk_mq_start_request(struct request *rq) trace_block_rq_issue(rq); - if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { - rq->io_start_time_ns = ktime_get_ns(); + if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags) && + !blk_rq_is_passthrough(rq)) { + rq->io_start_time_ns = blk_time_get_ns(); rq->stats_sectors = blk_rq_sectors(rq); rq->rq_flags |= RQF_STATS; rq_qos_issue(q, rq); @@ -1230,13 +1374,13 @@ void blk_mq_start_request(struct request *rq) blk_add_timer(rq); WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT); + rq->mq_hctx->tags->rqs[rq->tag] = rq; -#ifdef CONFIG_BLK_DEV_INTEGRITY if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE) - q->integrity.profile->prepare_fn(rq); -#endif + blk_integrity_prepare(rq); + if (rq->bio && rq->bio->bi_opf & REQ_POLLED) - WRITE_ONCE(rq->bio->bi_cookie, blk_rq_to_qc(rq)); + WRITE_ONCE(rq->bio->bi_cookie, rq->mq_hctx->queue_num); } EXPORT_SYMBOL(blk_mq_start_request); @@ -1268,10 +1412,13 @@ static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) if (!plug->multiple_queues && last && last->q != rq->q) plug->multiple_queues = true; - if (!plug->has_elevator && (rq->rq_flags & RQF_ELV)) + /* + * Any request allocated from sched tags can't be issued to + * ->queue_rqs() directly + */ + if (!plug->has_elevator && (rq->rq_flags & RQF_SCHED_TAGS)) plug->has_elevator = true; - rq->rq_next = NULL; - rq_list_add(&plug->mq_list, rq); + rq_list_add_tail(&plug->mq_list, rq); plug->rq_count++; } @@ -1289,20 +1436,20 @@ static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) */ void blk_execute_rq_nowait(struct request *rq, bool at_head) { + struct blk_mq_hw_ctx *hctx = rq->mq_hctx; + WARN_ON(irqs_disabled()); WARN_ON(!blk_rq_is_passthrough(rq)); blk_account_io_start(rq); - /* - * As plugging can be enabled for passthrough requests on a zoned - * device, directly accessing the plug instead of using blk_mq_plug() - * should not have any consequences. - */ - if (current->plug) + if (current->plug && !at_head) { blk_add_rq_to_plug(current->plug, rq); - else - blk_mq_sched_insert_request(rq, at_head, true, false); + return; + } + + blk_mq_insert_request(rq, at_head ? BLK_MQ_INSERT_AT_HEAD : 0); + blk_mq_run_hw_queue(hctx, hctx->flags & BLK_MQ_F_BLOCKING); } EXPORT_SYMBOL_GPL(blk_execute_rq_nowait); @@ -1326,8 +1473,6 @@ bool blk_rq_is_poll(struct request *rq) return false; if (rq->mq_hctx->type != HCTX_TYPE_POLL) return false; - if (WARN_ON_ONCE(!rq->bio)) - return false; return true; } EXPORT_SYMBOL_GPL(blk_rq_is_poll); @@ -1335,7 +1480,7 @@ EXPORT_SYMBOL_GPL(blk_rq_is_poll); static void blk_rq_poll_completion(struct request *rq, struct completion *wait) { do { - bio_poll(rq->bio, NULL, 0); + blk_hctx_poll(rq->q, rq->mq_hctx, NULL, 0); cond_resched(); } while (!completion_done(wait)); } @@ -1352,6 +1497,7 @@ static void blk_rq_poll_completion(struct request *rq, struct completion *wait) */ blk_status_t blk_execute_rq(struct request *rq, bool at_head) { + struct blk_mq_hw_ctx *hctx = rq->mq_hctx; struct blk_rq_wait wait = { .done = COMPLETION_INITIALIZER_ONSTACK(wait.done), }; @@ -1363,24 +1509,13 @@ blk_status_t blk_execute_rq(struct request *rq, bool at_head) rq->end_io = blk_end_sync_rq; blk_account_io_start(rq); - blk_mq_sched_insert_request(rq, at_head, true, false); + blk_mq_insert_request(rq, at_head ? BLK_MQ_INSERT_AT_HEAD : 0); + blk_mq_run_hw_queue(hctx, false); - if (blk_rq_is_poll(rq)) { + if (blk_rq_is_poll(rq)) blk_rq_poll_completion(rq, &wait.done); - } else { - /* - * Prevent hang_check timer from firing at us during very long - * I/O - */ - unsigned long hang_check = sysctl_hung_task_timeout_secs; - - if (hang_check) - while (!wait_for_completion_io_timeout(&wait.done, - hang_check * (HZ/2))) - ; - else - wait_for_completion_io(&wait.done); - } + else + blk_wait_io(&wait.done); return wait.ret; } @@ -1403,12 +1538,20 @@ static void __blk_mq_requeue_request(struct request *rq) void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) { + struct request_queue *q = rq->q; + unsigned long flags; + __blk_mq_requeue_request(rq); /* this request will be re-inserted to io scheduler queue */ blk_mq_sched_requeue_request(rq); - blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); + spin_lock_irqsave(&q->requeue_lock, flags); + list_add_tail(&rq->queuelist, &q->requeue_list); + spin_unlock_irqrestore(&q->requeue_lock, flags); + + if (kick_requeue_list) + blk_mq_kick_requeue_list(q); } EXPORT_SYMBOL(blk_mq_requeue_request); @@ -1417,63 +1560,38 @@ static void blk_mq_requeue_work(struct work_struct *work) struct request_queue *q = container_of(work, struct request_queue, requeue_work.work); LIST_HEAD(rq_list); - struct request *rq, *next; + LIST_HEAD(flush_list); + struct request *rq; spin_lock_irq(&q->requeue_lock); list_splice_init(&q->requeue_list, &rq_list); + list_splice_init(&q->flush_list, &flush_list); spin_unlock_irq(&q->requeue_lock); - list_for_each_entry_safe(rq, next, &rq_list, queuelist) { - if (!(rq->rq_flags & (RQF_SOFTBARRIER | RQF_DONTPREP))) - continue; - - rq->rq_flags &= ~RQF_SOFTBARRIER; + while (!list_empty(&rq_list)) { + rq = list_entry(rq_list.next, struct request, queuelist); list_del_init(&rq->queuelist); /* - * If RQF_DONTPREP, rq has contained some driver specific - * data, so insert it to hctx dispatch list to avoid any - * merge. + * If RQF_DONTPREP is set, the request has been started by the + * driver already and might have driver-specific data allocated + * already. Insert it into the hctx dispatch list to avoid + * block layer merges for the request. */ if (rq->rq_flags & RQF_DONTPREP) - blk_mq_request_bypass_insert(rq, false, false); + blk_mq_request_bypass_insert(rq, 0); else - blk_mq_sched_insert_request(rq, true, false, false); + blk_mq_insert_request(rq, BLK_MQ_INSERT_AT_HEAD); } - while (!list_empty(&rq_list)) { - rq = list_entry(rq_list.next, struct request, queuelist); + while (!list_empty(&flush_list)) { + rq = list_entry(flush_list.next, struct request, queuelist); list_del_init(&rq->queuelist); - blk_mq_sched_insert_request(rq, false, false, false); + blk_mq_insert_request(rq, 0); } blk_mq_run_hw_queues(q, false); } -void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, - bool kick_requeue_list) -{ - struct request_queue *q = rq->q; - unsigned long flags; - - /* - * We abuse this flag that is otherwise used by the I/O scheduler to - * request head insertion from the workqueue. - */ - BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); - - spin_lock_irqsave(&q->requeue_lock, flags); - if (at_head) { - rq->rq_flags |= RQF_SOFTBARRIER; - list_add(&rq->queuelist, &q->requeue_list); - } else { - list_add_tail(&rq->queuelist, &q->requeue_list); - } - spin_unlock_irqrestore(&q->requeue_lock, flags); - - if (kick_requeue_list) - blk_mq_kick_requeue_list(q); -} - void blk_mq_kick_requeue_list(struct request_queue *q) { kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, 0); @@ -1488,14 +1606,26 @@ void blk_mq_delay_kick_requeue_list(struct request_queue *q, } EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); +static bool blk_is_flush_data_rq(struct request *rq) +{ + return (rq->rq_flags & RQF_FLUSH_SEQ) && !is_flush_rq(rq); +} + static bool blk_mq_rq_inflight(struct request *rq, void *priv) { /* * If we find a request that isn't idle we know the queue is busy * as it's checked in the iter. * Return false to stop the iteration. + * + * In case of queue quiesce, if one flush data request is completed, + * don't count it as inflight given the flush sequence is suspended, + * and the original flush data request is invisible to driver, just + * like other pending requests because of quiesce */ - if (blk_mq_request_started(rq)) { + if (blk_mq_request_started(rq) && !(blk_queue_quiesced(rq->q) && + blk_is_flush_data_rq(rq) && + blk_mq_request_completed(rq))) { bool *busy = priv; *busy = true; @@ -1529,7 +1659,13 @@ static void blk_mq_rq_timed_out(struct request *req) blk_add_timer(req); } -static bool blk_mq_req_expired(struct request *rq, unsigned long *next) +struct blk_expired_data { + bool has_timedout_rq; + unsigned long next; + unsigned long timeout_start; +}; + +static bool blk_mq_req_expired(struct request *rq, struct blk_expired_data *expired) { unsigned long deadline; @@ -1539,13 +1675,13 @@ static bool blk_mq_req_expired(struct request *rq, unsigned long *next) return false; deadline = READ_ONCE(rq->deadline); - if (time_after_eq(jiffies, deadline)) + if (time_after_eq(expired->timeout_start, deadline)) return true; - if (*next == 0) - *next = deadline; - else if (time_after(*next, deadline)) - *next = deadline; + if (expired->next == 0) + expired->next = deadline; + else if (time_after(expired->next, deadline)) + expired->next = deadline; return false; } @@ -1561,7 +1697,7 @@ void blk_mq_put_rq_ref(struct request *rq) static bool blk_mq_check_expired(struct request *rq, void *priv) { - unsigned long *next = priv; + struct blk_expired_data *expired = priv; /* * blk_mq_queue_tag_busy_iter() has locked the request, so it cannot @@ -1570,7 +1706,18 @@ static bool blk_mq_check_expired(struct request *rq, void *priv) * it was completed and reallocated as a new request after returning * from blk_mq_check_expired(). */ - if (blk_mq_req_expired(rq, next)) + if (blk_mq_req_expired(rq, expired)) { + expired->has_timedout_rq = true; + return false; + } + return true; +} + +static bool blk_mq_handle_expired(struct request *rq, void *priv) +{ + struct blk_expired_data *expired = priv; + + if (blk_mq_req_expired(rq, expired)) blk_mq_rq_timed_out(rq); return true; } @@ -1579,7 +1726,9 @@ static void blk_mq_timeout_work(struct work_struct *work) { struct request_queue *q = container_of(work, struct request_queue, timeout_work); - unsigned long next = 0; + struct blk_expired_data expired = { + .timeout_start = jiffies, + }; struct blk_mq_hw_ctx *hctx; unsigned long i; @@ -1599,10 +1748,23 @@ static void blk_mq_timeout_work(struct work_struct *work) if (!percpu_ref_tryget(&q->q_usage_counter)) return; - blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next); + /* check if there is any timed-out request */ + blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &expired); + if (expired.has_timedout_rq) { + /* + * Before walking tags, we must ensure any submit started + * before the current time has finished. Since the submit + * uses srcu or rcu, wait for a synchronization point to + * ensure all running submits have finished + */ + blk_mq_wait_quiesce_done(q->tag_set); + + expired.next = 0; + blk_mq_queue_tag_busy_iter(q, blk_mq_handle_expired, &expired); + } - if (next != 0) { - mod_timer(&q->timeout, next); + if (expired.next != 0) { + mod_timer(&q->timeout, expired.next); } else { /* * Request timeouts are handled as a forward rolling timer. If @@ -1651,7 +1813,6 @@ void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); } -EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); struct dispatch_rq_data { struct blk_mq_hw_ctx *hctx; @@ -1693,7 +1854,7 @@ struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, return data.rq; } -static bool __blk_mq_alloc_driver_tag(struct request *rq) +bool __blk_mq_alloc_driver_tag(struct request *rq) { struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags; unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags; @@ -1714,20 +1875,7 @@ static bool __blk_mq_alloc_driver_tag(struct request *rq) return false; rq->tag = tag + tag_offset; - return true; -} - -bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq) -{ - if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq)) - return false; - - if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && - !(rq->rq_flags & RQF_MQ_INFLIGHT)) { - rq->rq_flags |= RQF_MQ_INFLIGHT; - __blk_mq_inc_active_requests(hctx); - } - hctx->tags->rqs[rq->tag] = rq; + blk_mq_inc_active_requests(rq->mq_hctx); return true; } @@ -1761,12 +1909,13 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, struct request *rq) { - struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags; + struct sbitmap_queue *sbq; struct wait_queue_head *wq; wait_queue_entry_t *wait; bool ret; - if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { + if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && + !(blk_mq_is_shared_tags(hctx->flags))) { blk_mq_sched_mark_restart_hctx(hctx); /* @@ -1784,6 +1933,10 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, if (!list_empty_careful(&wait->entry)) return false; + if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) + sbq = &hctx->tags->breserved_tags; + else + sbq = &hctx->tags->bitmap_tags; wq = &bt_wait_ptr(sbq, hctx)->wait; spin_lock_irq(&wq->lock); @@ -1799,6 +1952,22 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, __add_wait_queue(wq, wait); /* + * Add one explicit barrier since blk_mq_get_driver_tag() may + * not imply barrier in case of failure. + * + * Order adding us to wait queue and allocating driver tag. + * + * The pair is the one implied in sbitmap_queue_wake_up() which + * orders clearing sbitmap tag bits and waitqueue_active() in + * __sbitmap_queue_wake_up(), since waitqueue_active() is lockless + * + * Otherwise, re-order of adding wait queue and getting driver tag + * may cause __sbitmap_queue_wake_up() to wake up nothing because + * the waitqueue_active() may not observe us in wait queue. + */ + smp_mb(); + + /* * It's possible that a tag was freed in the window between the * allocation failure and adding the hardware queue to the wait * queue. @@ -1853,33 +2022,10 @@ static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy) static void blk_mq_handle_dev_resource(struct request *rq, struct list_head *list) { - struct request *next = - list_first_entry_or_null(list, struct request, queuelist); - - /* - * If an I/O scheduler has been configured and we got a driver tag for - * the next request already, free it. - */ - if (next) - blk_mq_put_driver_tag(next); - list_add(&rq->queuelist, list); __blk_mq_requeue_request(rq); } -static void blk_mq_handle_zone_resource(struct request *rq, - struct list_head *zone_list) -{ - /* - * If we end up here it is because we cannot dispatch a request to a - * specific zone due to LLD level zone-write locking or other zone - * related resource not being available. In this case, set the request - * aside in zone_list for retrying it later. - */ - list_add(&rq->queuelist, zone_list); - __blk_mq_requeue_request(rq); -} - enum prep_dispatch { PREP_DISPATCH_OK, PREP_DISPATCH_NO_TAG, @@ -1938,17 +2084,33 @@ static void blk_mq_release_budgets(struct request_queue *q, } /* + * blk_mq_commit_rqs will notify driver using bd->last that there is no + * more requests. (See comment in struct blk_mq_ops for commit_rqs for + * details) + * Attention, we should explicitly call this in unusual cases: + * 1) did not queue everything initially scheduled to queue + * 2) the last attempt to queue a request failed + */ +static void blk_mq_commit_rqs(struct blk_mq_hw_ctx *hctx, int queued, + bool from_schedule) +{ + if (hctx->queue->mq_ops->commit_rqs && queued) { + trace_block_unplug(hctx->queue, queued, !from_schedule); + hctx->queue->mq_ops->commit_rqs(hctx); + } +} + +/* * Returns true if we did some work AND can potentially do more. */ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, - unsigned int nr_budgets) + bool get_budget) { enum prep_dispatch prep; struct request_queue *q = hctx->queue; - struct request *rq, *nxt; - int errors, queued; + struct request *rq; + int queued; blk_status_t ret = BLK_STS_OK; - LIST_HEAD(zone_list); bool needs_resource = false; if (list_empty(list)) @@ -1957,38 +2119,22 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, /* * Now process all the entries, sending them to the driver. */ - errors = queued = 0; + queued = 0; do { struct blk_mq_queue_data bd; rq = list_first_entry(list, struct request, queuelist); WARN_ON_ONCE(hctx != rq->mq_hctx); - prep = blk_mq_prep_dispatch_rq(rq, !nr_budgets); + prep = blk_mq_prep_dispatch_rq(rq, get_budget); if (prep != PREP_DISPATCH_OK) break; list_del_init(&rq->queuelist); bd.rq = rq; + bd.last = list_empty(list); - /* - * Flag last if we have no more requests, or if we have more - * but can't assign a driver tag to it. - */ - if (list_empty(list)) - bd.last = true; - else { - nxt = list_first_entry(list, struct request, queuelist); - bd.last = !blk_mq_get_driver_tag(nxt); - } - - /* - * once the request is queued to lld, no need to cover the - * budget any more - */ - if (nr_budgets) - nr_budgets--; ret = q->mq_ops->queue_rq(hctx, &bd); switch (ret) { case BLK_STS_OK: @@ -2000,30 +2146,17 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, case BLK_STS_DEV_RESOURCE: blk_mq_handle_dev_resource(rq, list); goto out; - case BLK_STS_ZONE_RESOURCE: - /* - * Move the request to zone_list and keep going through - * the dispatch list to find more requests the drive can - * accept. - */ - blk_mq_handle_zone_resource(rq, &zone_list); - needs_resource = true; - break; default: - errors++; blk_mq_end_request(rq, ret); } } while (!list_empty(list)); out: - if (!list_empty(&zone_list)) - list_splice_tail_init(&zone_list, list); - /* If we didn't flush the entire list, we could have told the driver * there was more coming, but that turned out to be a lie. */ - if ((!list_empty(list) || errors || needs_resource || - ret == BLK_STS_DEV_RESOURCE) && q->mq_ops->commit_rqs && queued) - q->mq_ops->commit_rqs(hctx); + if (!list_empty(list) || ret != BLK_STS_OK) + blk_mq_commit_rqs(hctx, queued, false); + /* * Any items that need requeuing? Stuff them into hctx->dispatch, * that is where we will continue on next queue run. @@ -2032,9 +2165,14 @@ out: bool needs_restart; /* For non-shared tags, the RESTART check will suffice */ bool no_tag = prep == PREP_DISPATCH_NO_TAG && - (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED); + ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) || + blk_mq_is_shared_tags(hctx->flags)); - if (nr_budgets) + /* + * If the caller allocated budgets, free the budgets of the + * requests that have not yet been passed to the block driver. + */ + if (!get_budget) blk_mq_release_budgets(q, list); spin_lock(&hctx->lock); @@ -2087,28 +2225,10 @@ out: blk_mq_update_dispatch_busy(hctx, true); return false; - } else - blk_mq_update_dispatch_busy(hctx, false); - - return (queued + errors) != 0; -} - -/** - * __blk_mq_run_hw_queue - Run a hardware queue. - * @hctx: Pointer to the hardware queue to run. - * - * Send pending requests to the hardware. - */ -static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) -{ - /* - * We can't run the queue inline with ints disabled. Ensure that - * we catch bad users of this early. - */ - WARN_ON_ONCE(in_interrupt()); + } - blk_mq_run_dispatch_ops(hctx->queue, - blk_mq_sched_dispatch_requests(hctx)); + blk_mq_update_dispatch_busy(hctx, false); + return true; } static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) @@ -2121,6 +2241,15 @@ static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) } /* + * ->next_cpu is always calculated from hctx->cpumask, so simply use + * it for speeding up the check + */ +static bool blk_mq_hctx_empty_cpumask(struct blk_mq_hw_ctx *hctx) +{ + return hctx->next_cpu >= nr_cpu_ids; +} + +/* * It'd be great if the workqueue API had a way to pass * in a mask and had some smarts for more clever placement. * For now we just round-robin here, switching for every @@ -2131,7 +2260,8 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) bool tried = false; int next_cpu = hctx->next_cpu; - if (hctx->queue->nr_hw_queues == 1) + /* Switch to unbound if no allowable CPUs in this hctx */ + if (hctx->queue->nr_hw_queues == 1 || blk_mq_hctx_empty_cpumask(hctx)) return WORK_CPU_UNBOUND; if (--hctx->next_cpu_batch <= 0) { @@ -2167,43 +2297,38 @@ select_cpu: } /** - * __blk_mq_delay_run_hw_queue - Run (or schedule to run) a hardware queue. + * blk_mq_delay_run_hw_queue - Run a hardware queue asynchronously. * @hctx: Pointer to the hardware queue to run. - * @async: If we want to run the queue asynchronously. * @msecs: Milliseconds of delay to wait before running the queue. * - * If !@async, try to run the queue now. Else, run the queue asynchronously and - * with a delay of @msecs. + * Run a hardware queue asynchronously with a delay of @msecs. */ -static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, - unsigned long msecs) +void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) { if (unlikely(blk_mq_hctx_stopped(hctx))) return; - - if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { - if (cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)) { - __blk_mq_run_hw_queue(hctx); - return; - } - } - kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work, msecs_to_jiffies(msecs)); } +EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); -/** - * blk_mq_delay_run_hw_queue - Run a hardware queue asynchronously. - * @hctx: Pointer to the hardware queue to run. - * @msecs: Milliseconds of delay to wait before running the queue. - * - * Run a hardware queue asynchronously with a delay of @msecs. - */ -void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) +static inline bool blk_mq_hw_queue_need_run(struct blk_mq_hw_ctx *hctx) { - __blk_mq_delay_run_hw_queue(hctx, true, msecs); + bool need_run; + + /* + * When queue is quiesced, we may be switching io scheduler, or + * updating nr_hw_queues, or other things, and we can't run queue + * any more, even blk_mq_hctx_has_pending() can't be called safely. + * + * And queue will be rerun in blk_mq_unquiesce_queue() if it is + * quiesced. + */ + __blk_mq_run_dispatch_ops(hctx->queue, false, + need_run = !blk_queue_quiesced(hctx->queue) && + blk_mq_hctx_has_pending(hctx)); + return need_run; } -EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); /** * blk_mq_run_hw_queue - Start to run a hardware queue. @@ -2219,19 +2344,37 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) bool need_run; /* - * When queue is quiesced, we may be switching io scheduler, or - * updating nr_hw_queues, or other things, and we can't run queue - * any more, even __blk_mq_hctx_has_pending() can't be called safely. - * - * And queue will be rerun in blk_mq_unquiesce_queue() if it is - * quiesced. + * We can't run the queue inline with interrupts disabled. */ - __blk_mq_run_dispatch_ops(hctx->queue, false, - need_run = !blk_queue_quiesced(hctx->queue) && - blk_mq_hctx_has_pending(hctx)); + WARN_ON_ONCE(!async && in_interrupt()); + + might_sleep_if(!async && hctx->flags & BLK_MQ_F_BLOCKING); + + need_run = blk_mq_hw_queue_need_run(hctx); + if (!need_run) { + unsigned long flags; + + /* + * Synchronize with blk_mq_unquiesce_queue(), because we check + * if hw queue is quiesced locklessly above, we need the use + * ->queue_lock to make sure we see the up-to-date status to + * not miss rerunning the hw queue. + */ + spin_lock_irqsave(&hctx->queue->queue_lock, flags); + need_run = blk_mq_hw_queue_need_run(hctx); + spin_unlock_irqrestore(&hctx->queue->queue_lock, flags); + + if (!need_run) + return; + } + + if (async || !cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)) { + blk_mq_delay_run_hw_queue(hctx, 0); + return; + } - if (need_run) - __blk_mq_delay_run_hw_queue(hctx, async, 0); + blk_mq_run_dispatch_ops(hctx->queue, + blk_mq_sched_dispatch_requests(hctx)); } EXPORT_SYMBOL(blk_mq_run_hw_queue); @@ -2360,7 +2503,7 @@ void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) { clear_bit(BLK_MQ_S_STOPPED, &hctx->state); - blk_mq_run_hw_queue(hctx, false); + blk_mq_run_hw_queue(hctx, hctx->flags & BLK_MQ_F_BLOCKING); } EXPORT_SYMBOL(blk_mq_start_hw_queue); @@ -2380,6 +2523,12 @@ void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) return; clear_bit(BLK_MQ_S_STOPPED, &hctx->state); + /* + * Pairs with the smp_mb() in blk_mq_hctx_stopped() to order the + * clearing of BLK_MQ_S_STOPPED above and the checking of dispatch + * list in the subsequent routine. + */ + smp_mb__after_atomic(); blk_mq_run_hw_queue(hctx, async); } EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); @@ -2390,108 +2539,137 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) unsigned long i; queue_for_each_hw_ctx(q, hctx, i) - blk_mq_start_stopped_hw_queue(hctx, async); + blk_mq_start_stopped_hw_queue(hctx, async || + (hctx->flags & BLK_MQ_F_BLOCKING)); } EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); static void blk_mq_run_work_fn(struct work_struct *work) { - struct blk_mq_hw_ctx *hctx; - - hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); - - /* - * If we are stopped, don't run the queue. - */ - if (blk_mq_hctx_stopped(hctx)) - return; - - __blk_mq_run_hw_queue(hctx); -} - -static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, - struct request *rq, - bool at_head) -{ - struct blk_mq_ctx *ctx = rq->mq_ctx; - enum hctx_type type = hctx->type; - - lockdep_assert_held(&ctx->lock); + struct blk_mq_hw_ctx *hctx = + container_of(work, struct blk_mq_hw_ctx, run_work.work); - trace_block_rq_insert(rq); - - if (at_head) - list_add(&rq->queuelist, &ctx->rq_lists[type]); - else - list_add_tail(&rq->queuelist, &ctx->rq_lists[type]); -} - -void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, - bool at_head) -{ - struct blk_mq_ctx *ctx = rq->mq_ctx; - - lockdep_assert_held(&ctx->lock); - - __blk_mq_insert_req_list(hctx, rq, at_head); - blk_mq_hctx_mark_pending(hctx, ctx); + blk_mq_run_dispatch_ops(hctx->queue, + blk_mq_sched_dispatch_requests(hctx)); } /** * blk_mq_request_bypass_insert - Insert a request at dispatch list. * @rq: Pointer to request to be inserted. - * @at_head: true if the request should be inserted at the head of the list. - * @run_queue: If we should run the hardware queue after inserting the request. + * @flags: BLK_MQ_INSERT_* * * Should only be used carefully, when the caller knows we want to * bypass a potential IO scheduler on the target device. */ -void blk_mq_request_bypass_insert(struct request *rq, bool at_head, - bool run_queue) +static void blk_mq_request_bypass_insert(struct request *rq, blk_insert_t flags) { struct blk_mq_hw_ctx *hctx = rq->mq_hctx; spin_lock(&hctx->lock); - if (at_head) + if (flags & BLK_MQ_INSERT_AT_HEAD) list_add(&rq->queuelist, &hctx->dispatch); else list_add_tail(&rq->queuelist, &hctx->dispatch); spin_unlock(&hctx->lock); - - if (run_queue) - blk_mq_run_hw_queue(hctx, false); } -void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, - struct list_head *list) - +static void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, + struct blk_mq_ctx *ctx, struct list_head *list, + bool run_queue_async) { struct request *rq; enum hctx_type type = hctx->type; /* + * Try to issue requests directly if the hw queue isn't busy to save an + * extra enqueue & dequeue to the sw queue. + */ + if (!hctx->dispatch_busy && !run_queue_async) { + blk_mq_run_dispatch_ops(hctx->queue, + blk_mq_try_issue_list_directly(hctx, list)); + if (list_empty(list)) + goto out; + } + + /* * preemption doesn't flush plug list, so it's possible ctx->cpu is * offline now */ list_for_each_entry(rq, list, queuelist) { BUG_ON(rq->mq_ctx != ctx); trace_block_rq_insert(rq); + if (rq->cmd_flags & REQ_NOWAIT) + run_queue_async = true; } spin_lock(&ctx->lock); list_splice_tail_init(list, &ctx->rq_lists[type]); blk_mq_hctx_mark_pending(hctx, ctx); spin_unlock(&ctx->lock); +out: + blk_mq_run_hw_queue(hctx, run_queue_async); } -static void blk_mq_commit_rqs(struct blk_mq_hw_ctx *hctx, int *queued, - bool from_schedule) +static void blk_mq_insert_request(struct request *rq, blk_insert_t flags) { - if (hctx->queue->mq_ops->commit_rqs) { - trace_block_unplug(hctx->queue, *queued, !from_schedule); - hctx->queue->mq_ops->commit_rqs(hctx); + struct request_queue *q = rq->q; + struct blk_mq_ctx *ctx = rq->mq_ctx; + struct blk_mq_hw_ctx *hctx = rq->mq_hctx; + + if (blk_rq_is_passthrough(rq)) { + /* + * Passthrough request have to be added to hctx->dispatch + * directly. The device may be in a situation where it can't + * handle FS request, and always returns BLK_STS_RESOURCE for + * them, which gets them added to hctx->dispatch. + * + * If a passthrough request is required to unblock the queues, + * and it is added to the scheduler queue, there is no chance to + * dispatch it given we prioritize requests in hctx->dispatch. + */ + blk_mq_request_bypass_insert(rq, flags); + } else if (req_op(rq) == REQ_OP_FLUSH) { + /* + * Firstly normal IO request is inserted to scheduler queue or + * sw queue, meantime we add flush request to dispatch queue( + * hctx->dispatch) directly and there is at most one in-flight + * flush request for each hw queue, so it doesn't matter to add + * flush request to tail or front of the dispatch queue. + * + * Secondly in case of NCQ, flush request belongs to non-NCQ + * command, and queueing it will fail when there is any + * in-flight normal IO request(NCQ command). When adding flush + * rq to the front of hctx->dispatch, it is easier to introduce + * extra time to flush rq's latency because of S_SCHED_RESTART + * compared with adding to the tail of dispatch queue, then + * chance of flush merge is increased, and less flush requests + * will be issued to controller. It is observed that ~10% time + * is saved in blktests block/004 on disk attached to AHCI/NCQ + * drive when adding flush rq to the front of hctx->dispatch. + * + * Simply queue flush rq to the front of hctx->dispatch so that + * intensive flush workloads can benefit in case of NCQ HW. + */ + blk_mq_request_bypass_insert(rq, BLK_MQ_INSERT_AT_HEAD); + } else if (q->elevator) { + LIST_HEAD(list); + + WARN_ON_ONCE(rq->tag != BLK_MQ_NO_TAG); + + list_add(&rq->queuelist, &list); + q->elevator->type->ops.insert_requests(hctx, &list, flags); + } else { + trace_block_rq_insert(rq); + + spin_lock(&ctx->lock); + if (flags & BLK_MQ_INSERT_AT_HEAD) + list_add(&rq->queuelist, &ctx->rq_lists[hctx->type]); + else + list_add_tail(&rq->queuelist, + &ctx->rq_lists[hctx->type]); + blk_mq_hctx_mark_pending(hctx, ctx); + spin_unlock(&ctx->lock); } - *queued = 0; } static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, @@ -2502,8 +2680,15 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, if (bio->bi_opf & REQ_RAHEAD) rq->cmd_flags |= REQ_FAILFAST_MASK; + rq->bio = rq->biotail = bio; rq->__sector = bio->bi_iter.bi_sector; - blk_rq_bio_prep(rq, bio, nr_segs); + rq->__data_len = bio->bi_iter.bi_size; + rq->phys_gap_bit = bio->bi_bvec_gap_bit; + + rq->nr_phys_segments = nr_segs; + if (bio_integrity(bio)) + rq->nr_integrity_segments = blk_rq_count_integrity_sg(rq->q, + bio); /* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */ err = blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO); @@ -2545,49 +2730,19 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, return ret; } -static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, - struct request *rq, - bool bypass_insert, bool last) +static bool blk_mq_get_budget_and_tag(struct request *rq) { - struct request_queue *q = rq->q; - bool run_queue = true; int budget_token; - /* - * RCU or SRCU read lock is needed before checking quiesced flag. - * - * When queue is stopped or quiesced, ignore 'bypass_insert' from - * blk_mq_request_issue_directly(), and return BLK_STS_OK to caller, - * and avoid driver to try to dispatch again. - */ - if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) { - run_queue = false; - bypass_insert = false; - goto insert; - } - - if ((rq->rq_flags & RQF_ELV) && !bypass_insert) - goto insert; - - budget_token = blk_mq_get_dispatch_budget(q); + budget_token = blk_mq_get_dispatch_budget(rq->q); if (budget_token < 0) - goto insert; - + return false; blk_mq_set_rq_budget_token(rq, budget_token); - if (!blk_mq_get_driver_tag(rq)) { - blk_mq_put_dispatch_budget(q, budget_token); - goto insert; + blk_mq_put_dispatch_budget(rq->q, budget_token); + return false; } - - return __blk_mq_issue_directly(hctx, rq, last); -insert: - if (bypass_insert) - return BLK_STS_RESOURCE; - - blk_mq_sched_insert_request(rq, false, run_queue, false); - - return BLK_STS_OK; + return true; } /** @@ -2603,34 +2758,65 @@ insert: static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, struct request *rq) { - blk_status_t ret = - __blk_mq_try_issue_directly(hctx, rq, false, true); + blk_status_t ret; + + if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(rq->q)) { + blk_mq_insert_request(rq, 0); + blk_mq_run_hw_queue(hctx, false); + return; + } + + if ((rq->rq_flags & RQF_USE_SCHED) || !blk_mq_get_budget_and_tag(rq)) { + blk_mq_insert_request(rq, 0); + blk_mq_run_hw_queue(hctx, rq->cmd_flags & REQ_NOWAIT); + return; + } - if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) - blk_mq_request_bypass_insert(rq, false, true); - else if (ret != BLK_STS_OK) + ret = __blk_mq_issue_directly(hctx, rq, true); + switch (ret) { + case BLK_STS_OK: + break; + case BLK_STS_RESOURCE: + case BLK_STS_DEV_RESOURCE: + blk_mq_request_bypass_insert(rq, 0); + blk_mq_run_hw_queue(hctx, false); + break; + default: blk_mq_end_request(rq, ret); + break; + } } static blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) { - return __blk_mq_try_issue_directly(rq->mq_hctx, rq, true, last); + struct blk_mq_hw_ctx *hctx = rq->mq_hctx; + + if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(rq->q)) { + blk_mq_insert_request(rq, 0); + blk_mq_run_hw_queue(hctx, false); + return BLK_STS_OK; + } + + if (!blk_mq_get_budget_and_tag(rq)) + return BLK_STS_RESOURCE; + return __blk_mq_issue_directly(hctx, rq, last); } -static void blk_mq_plug_issue_direct(struct blk_plug *plug, bool from_schedule) +static void blk_mq_issue_direct(struct rq_list *rqs) { struct blk_mq_hw_ctx *hctx = NULL; struct request *rq; int queued = 0; - int errors = 0; + blk_status_t ret = BLK_STS_OK; - while ((rq = rq_list_pop(&plug->mq_list))) { - bool last = rq_list_empty(plug->mq_list); - blk_status_t ret; + while ((rq = rq_list_pop(rqs))) { + bool last = rq_list_empty(rqs); if (hctx != rq->mq_hctx) { - if (hctx) - blk_mq_commit_rqs(hctx, &queued, from_schedule); + if (hctx) { + blk_mq_commit_rqs(hctx, queued, false); + queued = 0; + } hctx = rq->mq_hctx; } @@ -2641,136 +2827,198 @@ static void blk_mq_plug_issue_direct(struct blk_plug *plug, bool from_schedule) break; case BLK_STS_RESOURCE: case BLK_STS_DEV_RESOURCE: - blk_mq_request_bypass_insert(rq, false, true); - blk_mq_commit_rqs(hctx, &queued, from_schedule); - return; + blk_mq_request_bypass_insert(rq, 0); + blk_mq_run_hw_queue(hctx, false); + goto out; default: blk_mq_end_request(rq, ret); - errors++; break; } } - /* - * If we didn't flush the entire list, we could have told the driver - * there was more coming, but that turned out to be a lie. - */ - if (errors) - blk_mq_commit_rqs(hctx, &queued, from_schedule); +out: + if (ret != BLK_STS_OK) + blk_mq_commit_rqs(hctx, queued, false); } -static void __blk_mq_flush_plug_list(struct request_queue *q, - struct blk_plug *plug) +static void __blk_mq_flush_list(struct request_queue *q, struct rq_list *rqs) { if (blk_queue_quiesced(q)) return; - q->mq_ops->queue_rqs(&plug->mq_list); + q->mq_ops->queue_rqs(rqs); +} + +static unsigned blk_mq_extract_queue_requests(struct rq_list *rqs, + struct rq_list *queue_rqs) +{ + struct request *rq = rq_list_pop(rqs); + struct request_queue *this_q = rq->q; + struct request **prev = &rqs->head; + struct rq_list matched_rqs = {}; + struct request *last = NULL; + unsigned depth = 1; + + rq_list_add_tail(&matched_rqs, rq); + while ((rq = *prev)) { + if (rq->q == this_q) { + /* move rq from rqs to matched_rqs */ + *prev = rq->rq_next; + rq_list_add_tail(&matched_rqs, rq); + depth++; + } else { + /* leave rq in rqs */ + prev = &rq->rq_next; + last = rq; + } + } + + rqs->tail = last; + *queue_rqs = matched_rqs; + return depth; } -static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) +static void blk_mq_dispatch_queue_requests(struct rq_list *rqs, unsigned depth) +{ + struct request_queue *q = rq_list_peek(rqs)->q; + + trace_block_unplug(q, depth, true); + + /* + * Peek first request and see if we have a ->queue_rqs() hook. + * If we do, we can dispatch the whole list in one go. + * We already know at this point that all requests belong to the + * same queue, caller must ensure that's the case. + */ + if (q->mq_ops->queue_rqs) { + blk_mq_run_dispatch_ops(q, __blk_mq_flush_list(q, rqs)); + if (rq_list_empty(rqs)) + return; + } + + blk_mq_run_dispatch_ops(q, blk_mq_issue_direct(rqs)); +} + +static void blk_mq_dispatch_list(struct rq_list *rqs, bool from_sched) { struct blk_mq_hw_ctx *this_hctx = NULL; struct blk_mq_ctx *this_ctx = NULL; - struct request *requeue_list = NULL; + struct rq_list requeue_list = {}; unsigned int depth = 0; + bool is_passthrough = false; LIST_HEAD(list); do { - struct request *rq = rq_list_pop(&plug->mq_list); + struct request *rq = rq_list_pop(rqs); if (!this_hctx) { this_hctx = rq->mq_hctx; this_ctx = rq->mq_ctx; - } else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) { - rq_list_add(&requeue_list, rq); + is_passthrough = blk_rq_is_passthrough(rq); + } else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx || + is_passthrough != blk_rq_is_passthrough(rq)) { + rq_list_add_tail(&requeue_list, rq); continue; } list_add_tail(&rq->queuelist, &list); depth++; - } while (!rq_list_empty(plug->mq_list)); + } while (!rq_list_empty(rqs)); - plug->mq_list = requeue_list; + *rqs = requeue_list; trace_block_unplug(this_hctx->queue, depth, !from_sched); - blk_mq_sched_insert_requests(this_hctx, this_ctx, &list, from_sched); + + percpu_ref_get(&this_hctx->queue->q_usage_counter); + /* passthrough requests should never be issued to the I/O scheduler */ + if (is_passthrough) { + spin_lock(&this_hctx->lock); + list_splice_tail_init(&list, &this_hctx->dispatch); + spin_unlock(&this_hctx->lock); + blk_mq_run_hw_queue(this_hctx, from_sched); + } else if (this_hctx->queue->elevator) { + this_hctx->queue->elevator->type->ops.insert_requests(this_hctx, + &list, 0); + blk_mq_run_hw_queue(this_hctx, from_sched); + } else { + blk_mq_insert_requests(this_hctx, this_ctx, &list, from_sched); + } + percpu_ref_put(&this_hctx->queue->q_usage_counter); +} + +static void blk_mq_dispatch_multiple_queue_requests(struct rq_list *rqs) +{ + do { + struct rq_list queue_rqs; + unsigned depth; + + depth = blk_mq_extract_queue_requests(rqs, &queue_rqs); + blk_mq_dispatch_queue_requests(&queue_rqs, depth); + while (!rq_list_empty(&queue_rqs)) + blk_mq_dispatch_list(&queue_rqs, false); + } while (!rq_list_empty(rqs)); } void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) { - struct request *rq; + unsigned int depth; - if (rq_list_empty(plug->mq_list)) + /* + * We may have been called recursively midway through handling + * plug->mq_list via a schedule() in the driver's queue_rq() callback. + * To avoid mq_list changing under our feet, clear rq_count early and + * bail out specifically if rq_count is 0 rather than checking + * whether the mq_list is empty. + */ + if (plug->rq_count == 0) return; + depth = plug->rq_count; plug->rq_count = 0; - if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) { - struct request_queue *q; - - rq = rq_list_peek(&plug->mq_list); - q = rq->q; - - /* - * Peek first request and see if we have a ->queue_rqs() hook. - * If we do, we can dispatch the whole plug list in one go. We - * already know at this point that all requests belong to the - * same queue, caller must ensure that's the case. - * - * Since we pass off the full list to the driver at this point, - * we do not increment the active request count for the queue. - * Bypass shared tags for now because of that. - */ - if (q->mq_ops->queue_rqs && - !(rq->mq_hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { - blk_mq_run_dispatch_ops(q, - __blk_mq_flush_plug_list(q, plug)); - if (rq_list_empty(plug->mq_list)) - return; + if (!plug->has_elevator && !from_schedule) { + if (plug->multiple_queues) { + blk_mq_dispatch_multiple_queue_requests(&plug->mq_list); + return; } - blk_mq_run_dispatch_ops(q, - blk_mq_plug_issue_direct(plug, false)); - if (rq_list_empty(plug->mq_list)) + blk_mq_dispatch_queue_requests(&plug->mq_list, depth); + if (rq_list_empty(&plug->mq_list)) return; } do { - blk_mq_dispatch_plug_list(plug, from_schedule); - } while (!rq_list_empty(plug->mq_list)); + blk_mq_dispatch_list(&plug->mq_list, from_schedule); + } while (!rq_list_empty(&plug->mq_list)); } -void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, +static void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, struct list_head *list) { int queued = 0; - int errors = 0; + blk_status_t ret = BLK_STS_OK; while (!list_empty(list)) { - blk_status_t ret; struct request *rq = list_first_entry(list, struct request, queuelist); list_del_init(&rq->queuelist); ret = blk_mq_request_issue_directly(rq, list_empty(list)); - if (ret != BLK_STS_OK) { - errors++; - if (ret == BLK_STS_RESOURCE || - ret == BLK_STS_DEV_RESOURCE) { - blk_mq_request_bypass_insert(rq, false, - list_empty(list)); - break; - } - blk_mq_end_request(rq, ret); - } else + switch (ret) { + case BLK_STS_OK: queued++; + break; + case BLK_STS_RESOURCE: + case BLK_STS_DEV_RESOURCE: + blk_mq_request_bypass_insert(rq, 0); + if (list_empty(list)) + blk_mq_run_hw_queue(hctx, false); + goto out; + default: + blk_mq_end_request(rq, ret); + break; + } } - /* - * If we didn't flush the entire list, we could have told - * the driver there was more coming, but that turned out to - * be a lie. - */ - if ((!list_empty(list) || errors) && - hctx->queue->mq_ops->commit_rqs && queued) - hctx->queue->mq_ops->commit_rqs(hctx); +out: + if (ret != BLK_STS_OK) + blk_mq_commit_rqs(hctx, queued, false); } static bool blk_mq_attempt_bio_merge(struct request_queue *q, @@ -2787,81 +3035,84 @@ static bool blk_mq_attempt_bio_merge(struct request_queue *q, static struct request *blk_mq_get_new_requests(struct request_queue *q, struct blk_plug *plug, - struct bio *bio, - unsigned int nsegs) + struct bio *bio) { struct blk_mq_alloc_data data = { .q = q, - .nr_tags = 1, + .flags = 0, + .shallow_depth = 0, .cmd_flags = bio->bi_opf, + .rq_flags = 0, + .nr_tags = 1, + .cached_rqs = NULL, + .ctx = NULL, + .hctx = NULL }; struct request *rq; - if (unlikely(bio_queue_enter(bio))) - return NULL; - - if (blk_mq_attempt_bio_merge(q, bio, nsegs)) - goto queue_exit; - rq_qos_throttle(q, bio); if (plug) { data.nr_tags = plug->nr_ios; plug->nr_ios = 1; - data.cached_rq = &plug->cached_rq; + data.cached_rqs = &plug->cached_rqs; } rq = __blk_mq_alloc_requests(&data); - if (rq) - return rq; - rq_qos_cleanup(q, bio); - if (bio->bi_opf & REQ_NOWAIT) - bio_wouldblock_error(bio); -queue_exit: - blk_queue_exit(q); - return NULL; + if (unlikely(!rq)) + rq_qos_cleanup(q, bio); + return rq; } -static inline struct request *blk_mq_get_cached_request(struct request_queue *q, - struct blk_plug *plug, struct bio **bio, unsigned int nsegs) +/* + * Check if there is a suitable cached request and return it. + */ +static struct request *blk_mq_peek_cached_request(struct blk_plug *plug, + struct request_queue *q, blk_opf_t opf) { + enum hctx_type type = blk_mq_get_hctx_type(opf); struct request *rq; if (!plug) return NULL; - rq = rq_list_peek(&plug->cached_rq); + rq = rq_list_peek(&plug->cached_rqs); if (!rq || rq->q != q) return NULL; - - if (blk_mq_attempt_bio_merge(q, *bio, nsegs)) { - *bio = NULL; - return NULL; - } - - if (blk_mq_get_hctx_type((*bio)->bi_opf) != rq->mq_hctx->type) + if (type != rq->mq_hctx->type && + (type != HCTX_TYPE_READ || rq->mq_hctx->type != HCTX_TYPE_DEFAULT)) return NULL; - if (op_is_flush(rq->cmd_flags) != op_is_flush((*bio)->bi_opf)) + if (op_is_flush(rq->cmd_flags) != op_is_flush(opf)) return NULL; + return rq; +} + +static void blk_mq_use_cached_rq(struct request *rq, struct blk_plug *plug, + struct bio *bio) +{ + if (rq_list_pop(&plug->cached_rqs) != rq) + WARN_ON_ONCE(1); /* * If any qos ->throttle() end up blocking, we will have flushed the * plug and hence killed the cached_rq list as well. Pop this entry * before we throttle. */ - plug->cached_rq = rq_list_next(rq); - rq_qos_throttle(q, *bio); + rq_qos_throttle(rq->q, bio); - rq->cmd_flags = (*bio)->bi_opf; + blk_mq_rq_time_init(rq, blk_time_get_ns()); + rq->cmd_flags = bio->bi_opf; INIT_LIST_HEAD(&rq->queuelist); - return rq; } -static void bio_set_ioprio(struct bio *bio) +static bool bio_unaligned(const struct bio *bio, struct request_queue *q) { - /* Nobody set ioprio so far? Initialize it based on task's nice value */ - if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE) - bio->bi_ioprio = get_current_ioprio(); - blkcg_set_ioprio(bio); + unsigned int bs_mask = queue_logical_block_size(q) - 1; + + /* .bi_sector of any zero sized bio need to be initialized */ + if ((bio->bi_iter.bi_size & bs_mask) || + ((bio->bi_iter.bi_sector << SECTOR_SHIFT) & bs_mask)) + return true; + return false; } /** @@ -2880,37 +3131,91 @@ static void bio_set_ioprio(struct bio *bio) void blk_mq_submit_bio(struct bio *bio) { struct request_queue *q = bdev_get_queue(bio->bi_bdev); - struct blk_plug *plug = blk_mq_plug(bio); + struct blk_plug *plug = current->plug; const int is_sync = op_is_sync(bio->bi_opf); + struct blk_mq_hw_ctx *hctx; + unsigned int nr_segs; struct request *rq; - unsigned int nr_segs = 1; blk_status_t ret; - bio = blk_queue_bounce(bio, q); - if (bio_may_exceed_limits(bio, &q->limits)) - bio = __bio_split_to_limits(bio, &q->limits, &nr_segs); - - if (!bio_integrity_prep(bio)) - return; + /* + * If the plug has a cached request for this queue, try to use it. + */ + rq = blk_mq_peek_cached_request(plug, q, bio->bi_opf); - bio_set_ioprio(bio); + /* + * A BIO that was released from a zone write plug has already been + * through the preparation in this function, already holds a reference + * on the queue usage counter, and is the only write BIO in-flight for + * the target zone. Go straight to preparing a request for it. + */ + if (bio_zone_write_plugging(bio)) { + nr_segs = bio->__bi_nr_segments; + if (rq) + blk_queue_exit(q); + goto new_request; + } - rq = blk_mq_get_cached_request(q, plug, &bio, nr_segs); + /* + * The cached request already holds a q_usage_counter reference and we + * don't have to acquire a new one if we use it. + */ if (!rq) { - if (!bio) - return; - rq = blk_mq_get_new_requests(q, plug, bio, nr_segs); - if (unlikely(!rq)) + if (unlikely(bio_queue_enter(bio))) return; } + /* + * Device reconfiguration may change logical block size or reduce the + * number of poll queues, so the checks for alignment and poll support + * have to be done with queue usage counter held. + */ + if (unlikely(bio_unaligned(bio, q))) { + bio_io_error(bio); + goto queue_exit; + } + + if ((bio->bi_opf & REQ_POLLED) && !blk_mq_can_poll(q)) { + bio->bi_status = BLK_STS_NOTSUPP; + bio_endio(bio); + goto queue_exit; + } + + bio = __bio_split_to_limits(bio, &q->limits, &nr_segs); + if (!bio) + goto queue_exit; + + if (!bio_integrity_prep(bio)) + goto queue_exit; + + blk_mq_bio_issue_init(q, bio); + if (blk_mq_attempt_bio_merge(q, bio, nr_segs)) + goto queue_exit; + + if (bio_needs_zone_write_plugging(bio)) { + if (blk_zone_plug_bio(bio, nr_segs)) + goto queue_exit; + } + +new_request: + if (rq) { + blk_mq_use_cached_rq(rq, plug, bio); + } else { + rq = blk_mq_get_new_requests(q, plug, bio); + if (unlikely(!rq)) { + if (bio->bi_opf & REQ_NOWAIT) + bio_wouldblock_error(bio); + goto queue_exit; + } + } + trace_block_getrq(bio); rq_qos_track(q, rq, bio); blk_mq_bio_to_request(rq, bio, nr_segs); - ret = blk_crypto_init_request(rq); + ret = blk_crypto_rq_get_keyslot(rq); if (ret != BLK_STS_OK) { bio->bi_status = ret; bio_endio(bio); @@ -2918,20 +3223,34 @@ void blk_mq_submit_bio(struct bio *bio) return; } - if (op_is_flush(bio->bi_opf)) { - blk_insert_flush(rq); + if (bio_zone_write_plugging(bio)) + blk_zone_write_plug_init_request(rq); + + if (op_is_flush(bio->bi_opf) && blk_insert_flush(rq)) return; - } - if (plug) + if (plug) { blk_add_rq_to_plug(plug, rq); - else if ((rq->rq_flags & RQF_ELV) || - (rq->mq_hctx->dispatch_busy && - (q->nr_hw_queues == 1 || !is_sync))) - blk_mq_sched_insert_request(rq, false, true, true); - else - blk_mq_run_dispatch_ops(rq->q, - blk_mq_try_issue_directly(rq->mq_hctx, rq)); + return; + } + + hctx = rq->mq_hctx; + if ((rq->rq_flags & RQF_USE_SCHED) || + (hctx->dispatch_busy && (q->nr_hw_queues == 1 || !is_sync))) { + blk_mq_insert_request(rq, 0); + blk_mq_run_hw_queue(hctx, true); + } else { + blk_mq_run_dispatch_ops(q, blk_mq_try_issue_directly(hctx, rq)); + } + return; + +queue_exit: + /* + * Don't drop the queue reference if we were trying to use a cached + * request and thus didn't acquire one. + */ + if (!rq) + blk_queue_exit(q); } #ifdef CONFIG_BLK_MQ_STACKING @@ -2942,7 +3261,8 @@ void blk_mq_submit_bio(struct bio *bio) blk_status_t blk_insert_cloned_request(struct request *rq) { struct request_queue *q = rq->q; - unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq)); + unsigned int max_sectors = blk_queue_get_max_sectors(rq); + unsigned int max_segments = blk_rq_get_max_segments(rq); blk_status_t ret; if (blk_rq_sectors(rq) > max_sectors) { @@ -2969,17 +3289,18 @@ blk_status_t blk_insert_cloned_request(struct request *rq) * original queue. */ rq->nr_phys_segments = blk_recalc_rq_segments(rq); - if (rq->nr_phys_segments > queue_max_segments(q)) { - printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n", - __func__, rq->nr_phys_segments, queue_max_segments(q)); + if (rq->nr_phys_segments > max_segments) { + printk(KERN_ERR "%s: over max segments limit. (%u > %u)\n", + __func__, rq->nr_phys_segments, max_segments); return BLK_STS_IOERR; } if (q->disk && should_fail_request(q->disk->part0, blk_rq_bytes(rq))) return BLK_STS_IOERR; - if (blk_crypto_insert_cloned_request(rq)) - return BLK_STS_IOERR; + ret = blk_crypto_rq_get_keyslot(rq); + if (ret != BLK_STS_OK) + return ret; blk_account_io_start(rq); @@ -2991,7 +3312,7 @@ blk_status_t blk_insert_cloned_request(struct request *rq) blk_mq_run_dispatch_ops(q, ret = blk_mq_request_issue_directly(rq, true)); if (ret) - blk_account_io_done(rq, ktime_get_ns()); + blk_account_io_done(rq, blk_time_get_ns()); return ret; } EXPORT_SYMBOL_GPL(blk_insert_cloned_request); @@ -3037,19 +3358,21 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, int (*bio_ctr)(struct bio *, struct bio *, void *), void *data) { - struct bio *bio, *bio_src; + struct bio *bio_src; if (!bs) bs = &fs_bio_set; __rq_for_each_bio(bio_src, rq_src) { - bio = bio_alloc_clone(rq->q->disk->part0, bio_src, gfp_mask, - bs); + struct bio *bio = bio_alloc_clone(rq->q->disk->part0, bio_src, + gfp_mask, bs); if (!bio) goto free_and_out; - if (bio_ctr && bio_ctr(bio, bio_src, data)) + if (bio_ctr && bio_ctr(bio, bio_src, data)) { + bio_put(bio); goto free_and_out; + } if (rq->bio) { rq->biotail->bi_next = bio; @@ -3057,7 +3380,6 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, } else { rq->bio = rq->biotail = bio; } - bio = NULL; } /* Copy attributes of the original request to the clone request. */ @@ -3068,7 +3390,8 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, rq->special_vec = rq_src->special_vec; } rq->nr_phys_segments = rq_src->nr_phys_segments; - rq->ioprio = rq_src->ioprio; + rq->nr_integrity_segments = rq_src->nr_integrity_segments; + rq->phys_gap_bit = rq_src->phys_gap_bit; if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0) goto free_and_out; @@ -3076,8 +3399,6 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, return 0; free_and_out: - if (bio) - bio_put(bio); blk_rq_unprep_clone(rq); return -ENOMEM; @@ -3116,7 +3437,6 @@ static void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags, struct blk_mq_tags *tags) { struct page *page; - unsigned long flags; /* * There is no need to clear mapping if driver tags is not initialized @@ -3140,22 +3460,12 @@ static void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags, } } } - - /* - * Wait until all pending iteration is done. - * - * Request reference is cleared and it is guaranteed to be observed - * after the ->lock is released. - */ - spin_lock_irqsave(&drv_tags->lock, flags); - spin_unlock_irqrestore(&drv_tags->lock, flags); } void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, unsigned int hctx_idx) { struct blk_mq_tags *drv_tags; - struct page *page; if (list_empty(&tags->page_list)) return; @@ -3179,27 +3489,20 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, } blk_mq_clear_rq_mapping(drv_tags, tags); - - while (!list_empty(&tags->page_list)) { - page = list_first_entry(&tags->page_list, struct page, lru); - list_del_init(&page->lru); - /* - * Remove kmemleak object previously allocated in - * blk_mq_alloc_rqs(). - */ - kmemleak_free(page_address(page)); - __free_pages(page, page->private); - } + /* + * Free request pages in SRCU callback, which is called from + * blk_mq_free_tags(). + */ } -void blk_mq_free_rq_map(struct blk_mq_tags *tags) +void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags) { kfree(tags->rqs); tags->rqs = NULL; kfree(tags->static_rqs); tags->static_rqs = NULL; - blk_mq_free_tags(tags); + blk_mq_free_tags(set, tags); } static enum hctx_type hctx_idx_to_type(struct blk_mq_tag_set *set, @@ -3240,29 +3543,29 @@ static struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, if (node == NUMA_NO_NODE) node = set->numa_node; - tags = blk_mq_init_tags(nr_tags, reserved_tags, node, - BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); + tags = blk_mq_init_tags(nr_tags, reserved_tags, set->flags, node); if (!tags) return NULL; tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, node); - if (!tags->rqs) { - blk_mq_free_tags(tags); - return NULL; - } + if (!tags->rqs) + goto err_free_tags; tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, node); - if (!tags->static_rqs) { - kfree(tags->rqs); - blk_mq_free_tags(tags); - return NULL; - } + if (!tags->static_rqs) + goto err_free_rqs; return tags; + +err_free_rqs: + kfree(tags->rqs); +err_free_tags: + blk_mq_free_tags(set, tags); + return NULL; } static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, @@ -3291,8 +3594,6 @@ static int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, if (node == NUMA_NO_NODE) node = set->numa_node; - INIT_LIST_HEAD(&tags->page_list); - /* * rq_size is the size of the request plus driver payload, rounded * to the cacheline size @@ -3379,28 +3680,48 @@ static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx) struct rq_iter_data data = { .hctx = hctx, }; + int srcu_idx; + srcu_idx = srcu_read_lock(&hctx->queue->tag_set->tags_srcu); blk_mq_all_tag_iter(tags, blk_mq_has_request, &data); + srcu_read_unlock(&hctx->queue->tag_set->tags_srcu, srcu_idx); + return data.has_rq; } -static inline bool blk_mq_last_cpu_in_hctx(unsigned int cpu, - struct blk_mq_hw_ctx *hctx) +static bool blk_mq_hctx_has_online_cpu(struct blk_mq_hw_ctx *hctx, + unsigned int this_cpu) { - if (cpumask_first_and(hctx->cpumask, cpu_online_mask) != cpu) - return false; - if (cpumask_next_and(cpu, hctx->cpumask, cpu_online_mask) < nr_cpu_ids) - return false; - return true; + enum hctx_type type = hctx->type; + int cpu; + + /* + * hctx->cpumask has to rule out isolated CPUs, but userspace still + * might submit IOs on these isolated CPUs, so use the queue map to + * check if all CPUs mapped to this hctx are offline + */ + for_each_online_cpu(cpu) { + struct blk_mq_hw_ctx *h = blk_mq_map_queue_type(hctx->queue, + type, cpu); + + if (h != hctx) + continue; + + /* this hctx has at least one online CPU */ + if (this_cpu != cpu) + return true; + } + + return false; } static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node) { struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_online); + int ret = 0; - if (!cpumask_test_cpu(cpu, hctx->cpumask) || - !blk_mq_last_cpu_in_hctx(cpu, hctx)) + if (blk_mq_hctx_has_online_cpu(hctx, cpu)) return 0; /* @@ -3419,12 +3740,40 @@ static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node) * frozen and there are no requests. */ if (percpu_ref_tryget(&hctx->queue->q_usage_counter)) { - while (blk_mq_hctx_has_requests(hctx)) + while (blk_mq_hctx_has_requests(hctx)) { + /* + * The wakeup capable IRQ handler of block device is + * not called during suspend. Skip the loop by checking + * pm_wakeup_pending to prevent the deadlock and improve + * suspend latency. + */ + if (pm_wakeup_pending()) { + clear_bit(BLK_MQ_S_INACTIVE, &hctx->state); + ret = -EBUSY; + break; + } msleep(5); + } percpu_ref_put(&hctx->queue->q_usage_counter); } - return 0; + return ret; +} + +/* + * Check if one CPU is mapped to the specified hctx + * + * Isolated CPUs have been ruled out from hctx->cpumask, which is supposed + * to be used for scheduling kworker only. For other usage, please call this + * helper for checking if one CPU belongs to the specified hctx + */ +static bool blk_mq_cpu_mapped_to_hctx(unsigned int cpu, + const struct blk_mq_hw_ctx *hctx) +{ + struct blk_mq_hw_ctx *mapped_hctx = blk_mq_map_queue_type(hctx->queue, + hctx->type, cpu); + + return mapped_hctx == hctx; } static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node) @@ -3432,7 +3781,7 @@ static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node) struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_online); - if (cpumask_test_cpu(cpu, hctx->cpumask)) + if (blk_mq_cpu_mapped_to_hctx(cpu, hctx)) clear_bit(BLK_MQ_S_INACTIVE, &hctx->state); return 0; } @@ -3450,7 +3799,7 @@ static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) enum hctx_type type; hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); - if (!cpumask_test_cpu(cpu, hctx->cpumask)) + if (!blk_mq_cpu_mapped_to_hctx(cpu, hctx)) return 0; ctx = __blk_mq_get_ctx(hctx->queue, cpu); @@ -3474,13 +3823,91 @@ static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) return 0; } -static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) +static void __blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) { - if (!(hctx->flags & BLK_MQ_F_STACKING)) + lockdep_assert_held(&blk_mq_cpuhp_lock); + + if (!(hctx->flags & BLK_MQ_F_STACKING) && + !hlist_unhashed(&hctx->cpuhp_online)) { cpuhp_state_remove_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE, &hctx->cpuhp_online); - cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, - &hctx->cpuhp_dead); + INIT_HLIST_NODE(&hctx->cpuhp_online); + } + + if (!hlist_unhashed(&hctx->cpuhp_dead)) { + cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, + &hctx->cpuhp_dead); + INIT_HLIST_NODE(&hctx->cpuhp_dead); + } +} + +static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) +{ + mutex_lock(&blk_mq_cpuhp_lock); + __blk_mq_remove_cpuhp(hctx); + mutex_unlock(&blk_mq_cpuhp_lock); +} + +static void __blk_mq_add_cpuhp(struct blk_mq_hw_ctx *hctx) +{ + lockdep_assert_held(&blk_mq_cpuhp_lock); + + if (!(hctx->flags & BLK_MQ_F_STACKING) && + hlist_unhashed(&hctx->cpuhp_online)) + cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE, + &hctx->cpuhp_online); + + if (hlist_unhashed(&hctx->cpuhp_dead)) + cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, + &hctx->cpuhp_dead); +} + +static void __blk_mq_remove_cpuhp_list(struct list_head *head) +{ + struct blk_mq_hw_ctx *hctx; + + lockdep_assert_held(&blk_mq_cpuhp_lock); + + list_for_each_entry(hctx, head, hctx_list) + __blk_mq_remove_cpuhp(hctx); +} + +/* + * Unregister cpuhp callbacks from exited hw queues + * + * Safe to call if this `request_queue` is live + */ +static void blk_mq_remove_hw_queues_cpuhp(struct request_queue *q) +{ + LIST_HEAD(hctx_list); + + spin_lock(&q->unused_hctx_lock); + list_splice_init(&q->unused_hctx_list, &hctx_list); + spin_unlock(&q->unused_hctx_lock); + + mutex_lock(&blk_mq_cpuhp_lock); + __blk_mq_remove_cpuhp_list(&hctx_list); + mutex_unlock(&blk_mq_cpuhp_lock); + + spin_lock(&q->unused_hctx_lock); + list_splice(&hctx_list, &q->unused_hctx_list); + spin_unlock(&q->unused_hctx_lock); +} + +/* + * Register cpuhp callbacks from all hw queues + * + * Safe to call if this `request_queue` is live + */ +static void blk_mq_add_hw_queues_cpuhp(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + unsigned long i; + + mutex_lock(&blk_mq_cpuhp_lock); + queue_for_each_hw_ctx(q, hctx, i) + __blk_mq_add_cpuhp(hctx); + mutex_unlock(&blk_mq_cpuhp_lock); } /* @@ -3491,7 +3918,6 @@ static void blk_mq_clear_flush_rq_mapping(struct blk_mq_tags *tags, unsigned int queue_depth, struct request *flush_rq) { int i; - unsigned long flags; /* The hw queue may not be mapped yet */ if (!tags) @@ -3501,15 +3927,14 @@ static void blk_mq_clear_flush_rq_mapping(struct blk_mq_tags *tags, for (i = 0; i < queue_depth; i++) cmpxchg(&tags->rqs[i], flush_rq, NULL); +} - /* - * Wait until all pending iteration is done. - * - * Request reference is cleared and it is guaranteed to be observed - * after the ->lock is released. - */ - spin_lock_irqsave(&tags->lock, flags); - spin_unlock_irqrestore(&tags->lock, flags); +static void blk_free_flush_queue_callback(struct rcu_head *head) +{ + struct blk_flush_queue *fq = + container_of(head, struct blk_flush_queue, rcu_head); + + blk_free_flush_queue(fq); } /* hctx->ctxs will be freed in queue's release handler */ @@ -3531,9 +3956,9 @@ static void blk_mq_exit_hctx(struct request_queue *q, if (set->ops->exit_hctx) set->ops->exit_hctx(hctx, hctx_idx); - blk_mq_remove_cpuhp(hctx); - - xa_erase(&q->hctx_table, hctx_idx); + call_srcu(&set->tags_srcu, &hctx->fq->rcu_head, + blk_free_flush_queue_callback); + hctx->fq = NULL; spin_lock(&q->unused_hctx_lock); list_add(&hctx->hctx_list, &q->unused_hctx_list); @@ -3549,6 +3974,7 @@ static void blk_mq_exit_hw_queues(struct request_queue *q, queue_for_each_hw_ctx(q, hctx, i) { if (i == nr_queue) break; + blk_mq_remove_cpuhp(hctx); blk_mq_exit_hctx(q, set, hctx, i); } } @@ -3557,36 +3983,33 @@ static int blk_mq_init_hctx(struct request_queue *q, struct blk_mq_tag_set *set, struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) { - hctx->queue_num = hctx_idx; + gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY; - if (!(hctx->flags & BLK_MQ_F_STACKING)) - cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE, - &hctx->cpuhp_online); - cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); + hctx->fq = blk_alloc_flush_queue(hctx->numa_node, set->cmd_size, gfp); + if (!hctx->fq) + goto fail; + + hctx->queue_num = hctx_idx; hctx->tags = set->tags[hctx_idx]; if (set->ops->init_hctx && set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) - goto unregister_cpu_notifier; + goto fail_free_fq; if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx, hctx->numa_node)) goto exit_hctx; - if (xa_insert(&q->hctx_table, hctx_idx, hctx, GFP_KERNEL)) - goto exit_flush_rq; - return 0; - exit_flush_rq: - if (set->ops->exit_request) - set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx); exit_hctx: if (set->ops->exit_hctx) set->ops->exit_hctx(hctx, hctx_idx); - unregister_cpu_notifier: - blk_mq_remove_cpuhp(hctx); + fail_free_fq: + blk_free_flush_queue(hctx->fq); + hctx->fq = NULL; + fail: return -1; } @@ -3612,6 +4035,8 @@ blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); spin_lock_init(&hctx->lock); INIT_LIST_HEAD(&hctx->dispatch); + INIT_HLIST_NODE(&hctx->cpuhp_dead); + INIT_HLIST_NODE(&hctx->cpuhp_online); hctx->queue = q; hctx->flags = set->flags & ~BLK_MQ_F_TAG_QUEUE_SHARED; @@ -3635,16 +4060,10 @@ blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); INIT_LIST_HEAD(&hctx->dispatch_wait.entry); - hctx->fq = blk_alloc_flush_queue(hctx->numa_node, set->cmd_size, gfp); - if (!hctx->fq) - goto free_bitmap; - blk_mq_hctx_kobj_init(hctx); return hctx; - free_bitmap: - sbitmap_free(&hctx->ctx_map); free_ctxs: kfree(hctx->ctxs); free_cpumask: @@ -3698,7 +4117,7 @@ struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set, ret = blk_mq_alloc_rqs(set, tags, hctx_idx, depth); if (ret) { - blk_mq_free_rq_map(tags); + blk_mq_free_rq_map(set, tags); return NULL; } @@ -3726,7 +4145,7 @@ void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set, { if (tags) { blk_mq_free_rqs(set, tags, hctx_idx); - blk_mq_free_rq_map(tags); + blk_mq_free_rq_map(set, tags); } } @@ -3808,6 +4227,8 @@ static void blk_mq_map_swqueue(struct request_queue *q) } queue_for_each_hw_ctx(q, hctx, i) { + int cpu; + /* * If no software queues are mapped to this hardware queue, * disable it and free the request entries. @@ -3835,6 +4256,15 @@ static void blk_mq_map_swqueue(struct request_queue *q) sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); /* + * Rule out isolated CPUs from hctx->cpumask to avoid + * running block kworker on isolated CPUs + */ + for_each_cpu(cpu, hctx->cpumask) { + if (cpu_is_isolated(cpu)) + cpumask_clear_cpu(cpu, hctx->cpumask); + } + + /* * Initialize batch roundrobin counts */ hctx->next_cpu = blk_mq_first_mapped_cpu(hctx); @@ -3865,13 +4295,14 @@ static void blk_mq_update_tag_set_shared(struct blk_mq_tag_set *set, bool shared) { struct request_queue *q; + unsigned int memflags; lockdep_assert_held(&set->tag_list_lock); list_for_each_entry(q, &set->tag_list, tag_set_list) { - blk_mq_freeze_queue(q); + memflags = blk_mq_freeze_queue(q); queue_set_hctx_shared(q, shared); - blk_mq_unfreeze_queue(q); + blk_mq_unfreeze_queue(q, memflags); } } @@ -3960,7 +4391,7 @@ void blk_mq_release(struct request_queue *q) kobject_put(&hctx->kobj); } - xa_destroy(&q->hctx_table); + kfree(q->queue_hw_ctx); /* * release .mq_kobj and sw queue's kobject now because @@ -3969,15 +4400,22 @@ void blk_mq_release(struct request_queue *q) blk_mq_sysfs_deinit(q); } -static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set, - void *queuedata) +struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set, + struct queue_limits *lim, void *queuedata) { + struct queue_limits default_lim = { }; struct request_queue *q; int ret; - q = blk_alloc_queue(set->numa_node, set->flags & BLK_MQ_F_BLOCKING); - if (!q) - return ERR_PTR(-ENOMEM); + if (!lim) + lim = &default_lim; + lim->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT; + if (set->nr_maps > HCTX_TYPE_POLL) + lim->features |= BLK_FEAT_POLL; + + q = blk_alloc_queue(lim, set->numa_node); + if (IS_ERR(q)) + return q; q->queuedata = queuedata; ret = blk_mq_init_allocated_queue(set, q); if (ret) { @@ -3986,19 +4424,15 @@ static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set, } return q; } - -struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) -{ - return blk_mq_init_queue_data(set, NULL); -} -EXPORT_SYMBOL(blk_mq_init_queue); +EXPORT_SYMBOL(blk_mq_alloc_queue); /** * blk_mq_destroy_queue - shutdown a request queue * @q: request queue to shutdown * - * This shuts down a request queue allocated by blk_mq_init_queue() and drops - * the initial reference. All future requests will failed with -ENODEV. + * This shuts down a request queue allocated by blk_mq_alloc_queue(). All future + * requests will be failed with -ENODEV. The caller is responsible for dropping + * the reference from blk_mq_alloc_queue() by calling blk_put_queue(). * * Context: can sleep */ @@ -4011,30 +4445,29 @@ void blk_mq_destroy_queue(struct request_queue *q) blk_queue_flag_set(QUEUE_FLAG_DYING, q); blk_queue_start_drain(q); - blk_freeze_queue(q); + blk_mq_freeze_queue_wait(q); blk_sync_queue(q); blk_mq_cancel_work_sync(q); blk_mq_exit_queue(q); - - /* @q is and will stay empty, shutdown and put */ - blk_put_queue(q); } EXPORT_SYMBOL(blk_mq_destroy_queue); -struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata, +struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, + struct queue_limits *lim, void *queuedata, struct lock_class_key *lkclass) { struct request_queue *q; struct gendisk *disk; - q = blk_mq_init_queue_data(set, queuedata); + q = blk_mq_alloc_queue(set, lim, queuedata); if (IS_ERR(q)) return ERR_CAST(q); disk = __alloc_disk_node(q, set->numa_node, lkclass); if (!disk) { blk_mq_destroy_queue(q); + blk_put_queue(q); return ERR_PTR(-ENOMEM); } set_bit(GD_OWNS_QUEUE, &disk->state); @@ -4045,12 +4478,26 @@ EXPORT_SYMBOL(__blk_mq_alloc_disk); struct gendisk *blk_mq_alloc_disk_for_queue(struct request_queue *q, struct lock_class_key *lkclass) { + struct gendisk *disk; + if (!blk_get_queue(q)) return NULL; - return __alloc_disk_node(q, NUMA_NO_NODE, lkclass); + disk = __alloc_disk_node(q, NUMA_NO_NODE, lkclass); + if (!disk) + blk_put_queue(q); + return disk; } EXPORT_SYMBOL(blk_mq_alloc_disk_for_queue); +/* + * Only hctx removed from cpuhp list can be reused + */ +static bool blk_mq_hctx_is_reusable(struct blk_mq_hw_ctx *hctx) +{ + return hlist_unhashed(&hctx->cpuhp_online) && + hlist_unhashed(&hctx->cpuhp_dead); +} + static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( struct blk_mq_tag_set *set, struct request_queue *q, int hctx_idx, int node) @@ -4060,7 +4507,7 @@ static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( /* reuse dead hctx first */ spin_lock(&q->unused_hctx_lock); list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) { - if (tmp->numa_node == node) { + if (tmp->numa_node == node && blk_mq_hctx_is_reusable(tmp)) { hctx = tmp; break; } @@ -4085,31 +4532,52 @@ static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( return NULL; } -static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, - struct request_queue *q) +static void __blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, + struct request_queue *q) { - struct blk_mq_hw_ctx *hctx; - unsigned long i, j; + int i, j, end; + struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; + + if (q->nr_hw_queues < set->nr_hw_queues) { + struct blk_mq_hw_ctx **new_hctxs; + + new_hctxs = kcalloc_node(set->nr_hw_queues, + sizeof(*new_hctxs), GFP_KERNEL, + set->numa_node); + if (!new_hctxs) + return; + if (hctxs) + memcpy(new_hctxs, hctxs, q->nr_hw_queues * + sizeof(*hctxs)); + rcu_assign_pointer(q->queue_hw_ctx, new_hctxs); + /* + * Make sure reading the old queue_hw_ctx from other + * context concurrently won't trigger uaf. + */ + synchronize_rcu_expedited(); + kfree(hctxs); + hctxs = new_hctxs; + } - /* protect against switching io scheduler */ - mutex_lock(&q->sysfs_lock); for (i = 0; i < set->nr_hw_queues; i++) { int old_node; int node = blk_mq_get_hctx_node(set, i); - struct blk_mq_hw_ctx *old_hctx = xa_load(&q->hctx_table, i); + struct blk_mq_hw_ctx *old_hctx = hctxs[i]; if (old_hctx) { old_node = old_hctx->numa_node; blk_mq_exit_hctx(q, set, old_hctx, i); } - if (!blk_mq_alloc_and_init_hctx(set, q, i, node)) { + hctxs[i] = blk_mq_alloc_and_init_hctx(set, q, i, node); + if (!hctxs[i]) { if (!old_hctx) break; pr_warn("Allocate new hctx on node %d fails, fallback to previous one on node %d\n", node, old_node); - hctx = blk_mq_alloc_and_init_hctx(set, q, i, old_node); - WARN_ON_ONCE(!hctx); + hctxs[i] = blk_mq_alloc_and_init_hctx(set, q, i, + old_node); + WARN_ON_ONCE(!hctxs[i]); } } /* @@ -4118,44 +4586,49 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, */ if (i != set->nr_hw_queues) { j = q->nr_hw_queues; + end = i; } else { j = i; + end = q->nr_hw_queues; q->nr_hw_queues = set->nr_hw_queues; } - xa_for_each_start(&q->hctx_table, j, hctx, j) - blk_mq_exit_hctx(q, set, hctx, j); - mutex_unlock(&q->sysfs_lock); + for (; j < end; j++) { + struct blk_mq_hw_ctx *hctx = hctxs[j]; + + if (hctx) { + blk_mq_exit_hctx(q, set, hctx, j); + hctxs[j] = NULL; + } + } } -static void blk_mq_update_poll_flag(struct request_queue *q) +static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, + struct request_queue *q) { - struct blk_mq_tag_set *set = q->tag_set; + __blk_mq_realloc_hw_ctxs(set, q); - if (set->nr_maps > HCTX_TYPE_POLL && - set->map[HCTX_TYPE_POLL].nr_queues) - blk_queue_flag_set(QUEUE_FLAG_POLL, q); - else - blk_queue_flag_clear(QUEUE_FLAG_POLL, q); + /* unregister cpuhp callbacks for exited hctxs */ + blk_mq_remove_hw_queues_cpuhp(q); + + /* register cpuhp for new initialized hctxs */ + blk_mq_add_hw_queues_cpuhp(q); } int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, struct request_queue *q) { - WARN_ON_ONCE(blk_queue_has_srcu(q) != - !!(set->flags & BLK_MQ_F_BLOCKING)); - /* mark the queue as mq asap */ q->mq_ops = set->ops; - q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn, - blk_mq_poll_stats_bkt, - BLK_MQ_POLL_STATS_BKTS, q); - if (!q->poll_cb) - goto err_exit; + /* + * ->tag_set has to be setup before initialize hctx, which cpuphp + * handler needs it for checking queue mapping + */ + q->tag_set = set; if (blk_mq_alloc_ctxs(q)) - goto err_poll; + goto err_exit; /* init q->mq_kobj and sw queues' kobjects */ blk_mq_sysfs_init(q); @@ -4163,8 +4636,6 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, INIT_LIST_HEAD(&q->unused_hctx_list); spin_lock_init(&q->unused_hctx_lock); - xa_init(&q->hctx_table); - blk_mq_realloc_hw_ctxs(set, q); if (!q->nr_hw_queues) goto err_hctxs; @@ -4172,32 +4643,22 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, INIT_WORK(&q->timeout_work, blk_mq_timeout_work); blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); - q->tag_set = set; - q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; - blk_mq_update_poll_flag(q); INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); + INIT_LIST_HEAD(&q->flush_list); INIT_LIST_HEAD(&q->requeue_list); spin_lock_init(&q->requeue_lock); q->nr_requests = set->queue_depth; - /* - * Default to classic polling - */ - q->poll_nsec = BLK_MQ_POLL_CLASSIC; - blk_mq_init_cpu_queues(q, set->nr_hw_queues); - blk_mq_add_queue_tag_set(set, q); blk_mq_map_swqueue(q); + blk_mq_add_queue_tag_set(set, q); return 0; err_hctxs: blk_mq_release(q); -err_poll: - blk_stat_free_callback(q->poll_cb); - q->poll_cb = NULL; err_exit: q->mq_ops = NULL; return -ENOMEM; @@ -4292,7 +4753,7 @@ static void blk_mq_update_queue_map(struct blk_mq_tag_set *set) if (set->nr_maps == 1) set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues; - if (set->ops->map_queues && !is_kdump_kernel()) { + if (set->ops->map_queues) { int i; /* @@ -4320,12 +4781,13 @@ static void blk_mq_update_queue_map(struct blk_mq_tag_set *set) } static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set, - int cur_nr_hw_queues, int new_nr_hw_queues) + int new_nr_hw_queues) { struct blk_mq_tags **new_tags; + int i; - if (cur_nr_hw_queues >= new_nr_hw_queues) - return 0; + if (set->nr_hw_queues >= new_nr_hw_queues) + goto done; new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *), GFP_KERNEL, set->numa_node); @@ -4333,19 +4795,23 @@ static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set, return -ENOMEM; if (set->tags) - memcpy(new_tags, set->tags, cur_nr_hw_queues * + memcpy(new_tags, set->tags, set->nr_hw_queues * sizeof(*set->tags)); kfree(set->tags); set->tags = new_tags; - set->nr_hw_queues = new_nr_hw_queues; - return 0; -} + for (i = set->nr_hw_queues; i < new_nr_hw_queues; i++) { + if (!__blk_mq_alloc_map_and_rqs(set, i)) { + while (--i >= set->nr_hw_queues) + __blk_mq_free_map_and_rqs(set, i); + return -ENOMEM; + } + cond_resched(); + } -static int blk_mq_alloc_tag_set_tags(struct blk_mq_tag_set *set, - int new_nr_hw_queues) -{ - return blk_mq_realloc_tag_set_tags(set, 0, new_nr_hw_queues); +done: + set->nr_hw_queues = new_nr_hw_queues; + return 0; } /* @@ -4386,14 +4852,12 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) /* * If a crashdump is active, then we are potentially in a very - * memory constrained environment. Limit us to 1 queue and - * 64 tags to prevent using too much memory. + * memory constrained environment. Limit us to 64 tags to prevent + * using too much memory. */ - if (is_kdump_kernel()) { - set->nr_hw_queues = 1; - set->nr_maps = 1; + if (is_kdump_kernel()) set->queue_depth = min(64U, set->queue_depth); - } + /* * There is no use for more h/w queues than cpus if we just have * a single map @@ -4401,17 +4865,34 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids) set->nr_hw_queues = nr_cpu_ids; - if (blk_mq_alloc_tag_set_tags(set, set->nr_hw_queues) < 0) - return -ENOMEM; + if (set->flags & BLK_MQ_F_BLOCKING) { + set->srcu = kmalloc(sizeof(*set->srcu), GFP_KERNEL); + if (!set->srcu) + return -ENOMEM; + ret = init_srcu_struct(set->srcu); + if (ret) + goto out_free_srcu; + } + ret = init_srcu_struct(&set->tags_srcu); + if (ret) + goto out_cleanup_srcu; + + init_rwsem(&set->update_nr_hwq_lock); ret = -ENOMEM; + set->tags = kcalloc_node(set->nr_hw_queues, + sizeof(struct blk_mq_tags *), GFP_KERNEL, + set->numa_node); + if (!set->tags) + goto out_cleanup_tags_srcu; + for (i = 0; i < set->nr_maps; i++) { set->map[i].mq_map = kcalloc_node(nr_cpu_ids, sizeof(set->map[i].mq_map[0]), GFP_KERNEL, set->numa_node); if (!set->map[i].mq_map) goto out_free_mq_map; - set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues; + set->map[i].nr_queues = set->nr_hw_queues; } blk_mq_update_queue_map(set); @@ -4432,6 +4913,14 @@ out_free_mq_map: } kfree(set->tags); set->tags = NULL; +out_cleanup_tags_srcu: + cleanup_srcu_struct(&set->tags_srcu); +out_cleanup_srcu: + if (set->flags & BLK_MQ_F_BLOCKING) + cleanup_srcu_struct(set->srcu); +out_free_srcu: + if (set->flags & BLK_MQ_F_BLOCKING) + kfree(set->srcu); return ret; } EXPORT_SYMBOL(blk_mq_alloc_tag_set); @@ -4471,146 +4960,142 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) kfree(set->tags); set->tags = NULL; + + srcu_barrier(&set->tags_srcu); + cleanup_srcu_struct(&set->tags_srcu); + if (set->flags & BLK_MQ_F_BLOCKING) { + cleanup_srcu_struct(set->srcu); + kfree(set->srcu); + } } EXPORT_SYMBOL(blk_mq_free_tag_set); -int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) +struct elevator_tags *blk_mq_update_nr_requests(struct request_queue *q, + struct elevator_tags *et, + unsigned int nr) { struct blk_mq_tag_set *set = q->tag_set; + struct elevator_tags *old_et = NULL; struct blk_mq_hw_ctx *hctx; - int ret; unsigned long i; - if (!set) - return -EINVAL; - - if (q->nr_requests == nr) - return 0; - - blk_mq_freeze_queue(q); blk_mq_quiesce_queue(q); - ret = 0; - queue_for_each_hw_ctx(q, hctx, i) { - if (!hctx->tags) - continue; + if (blk_mq_is_shared_tags(set->flags)) { /* - * If we're using an MQ scheduler, just update the scheduler - * queue depth. This is similar to what the old code would do. + * Shared tags, for sched tags, we allocate max initially hence + * tags can't grow, see blk_mq_alloc_sched_tags(). */ - if (hctx->sched_tags) { - ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, - nr, true); - } else { - ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr, - false); + if (q->elevator) + blk_mq_tag_update_sched_shared_tags(q, nr); + else + blk_mq_tag_resize_shared_tags(set, nr); + } else if (!q->elevator) { + /* + * Non-shared hardware tags, nr is already checked from + * queue_requests_store() and tags can't grow. + */ + queue_for_each_hw_ctx(q, hctx, i) { + if (!hctx->tags) + continue; + sbitmap_queue_resize(&hctx->tags->bitmap_tags, + nr - hctx->tags->nr_reserved_tags); } - if (ret) - break; - if (q->elevator && q->elevator->type->ops.depth_updated) - q->elevator->type->ops.depth_updated(hctx); - } - if (!ret) { - q->nr_requests = nr; - if (blk_mq_is_shared_tags(set->flags)) { - if (q->elevator) - blk_mq_tag_update_sched_shared_tags(q); - else - blk_mq_tag_resize_shared_tags(set, nr); + } else if (nr <= q->elevator->et->nr_requests) { + /* Non-shared sched tags, and tags don't grow. */ + queue_for_each_hw_ctx(q, hctx, i) { + if (!hctx->sched_tags) + continue; + sbitmap_queue_resize(&hctx->sched_tags->bitmap_tags, + nr - hctx->sched_tags->nr_reserved_tags); } + } else { + /* Non-shared sched tags, and tags grow */ + queue_for_each_hw_ctx(q, hctx, i) + hctx->sched_tags = et->tags[i]; + old_et = q->elevator->et; + q->elevator->et = et; } - blk_mq_unquiesce_queue(q); - blk_mq_unfreeze_queue(q); + q->nr_requests = nr; + if (q->elevator && q->elevator->type->ops.depth_updated) + q->elevator->type->ops.depth_updated(q); - return ret; + blk_mq_unquiesce_queue(q); + return old_et; } /* - * request_queue and elevator_type pair. - * It is just used by __blk_mq_update_nr_hw_queues to cache - * the elevator_type associated with a request_queue. - */ -struct blk_mq_qe_pair { - struct list_head node; - struct request_queue *q; - struct elevator_type *type; -}; - -/* - * Cache the elevator_type in qe pair list and switch the - * io scheduler to 'none' + * Switch back to the elevator type stored in the xarray. */ -static bool blk_mq_elv_switch_none(struct list_head *head, - struct request_queue *q) +static void blk_mq_elv_switch_back(struct request_queue *q, + struct xarray *elv_tbl) { - struct blk_mq_qe_pair *qe; - - if (!q->elevator) - return true; + struct elv_change_ctx *ctx = xa_load(elv_tbl, q->id); - qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); - if (!qe) - return false; - - /* q->elevator needs protection from ->sysfs_lock */ - mutex_lock(&q->sysfs_lock); - - INIT_LIST_HEAD(&qe->node); - qe->q = q; - qe->type = q->elevator->type; - list_add(&qe->node, head); + if (WARN_ON_ONCE(!ctx)) + return; - /* - * After elevator_switch, the previous elevator_queue will be - * released by elevator_release. The reference of the io scheduler - * module get by elevator_get will also be put. So we need to get - * a reference of the io scheduler module here to prevent it to be - * removed. - */ - __module_get(qe->type->elevator_owner); - elevator_switch(q, NULL); - mutex_unlock(&q->sysfs_lock); + /* The elv_update_nr_hw_queues unfreezes the queue. */ + elv_update_nr_hw_queues(q, ctx); - return true; + /* Drop the reference acquired in blk_mq_elv_switch_none. */ + if (ctx->type) + elevator_put(ctx->type); } -static struct blk_mq_qe_pair *blk_lookup_qe_pair(struct list_head *head, - struct request_queue *q) +/* + * Stores elevator name and type in ctx and set current elevator to none. + */ +static int blk_mq_elv_switch_none(struct request_queue *q, + struct xarray *elv_tbl) { - struct blk_mq_qe_pair *qe; + struct elv_change_ctx *ctx; - list_for_each_entry(qe, head, node) - if (qe->q == q) - return qe; + lockdep_assert_held_write(&q->tag_set->update_nr_hwq_lock); - return NULL; -} + /* + * Accessing q->elevator without holding q->elevator_lock is safe here + * because we're called from nr_hw_queue update which is protected by + * set->update_nr_hwq_lock in the writer context. So, scheduler update/ + * switch code (which acquires the same lock in the reader context) + * can't run concurrently. + */ + if (q->elevator) { + ctx = xa_load(elv_tbl, q->id); + if (WARN_ON_ONCE(!ctx)) + return -ENOENT; -static void blk_mq_elv_switch_back(struct list_head *head, - struct request_queue *q) -{ - struct blk_mq_qe_pair *qe; - struct elevator_type *t; + ctx->name = q->elevator->type->elevator_name; - qe = blk_lookup_qe_pair(head, q); - if (!qe) - return; - t = qe->type; - list_del(&qe->node); - kfree(qe); + /* + * Before we switch elevator to 'none', take a reference to + * the elevator module so that while nr_hw_queue update is + * running, no one can remove elevator module. We'd put the + * reference to elevator module later when we switch back + * elevator. + */ + __elevator_get(q->elevator->type); - mutex_lock(&q->sysfs_lock); - elevator_switch(q, t); - mutex_unlock(&q->sysfs_lock); + /* + * Store elevator type so that we can release the reference + * taken above later. + */ + ctx->type = q->elevator->type; + elevator_set_none(q); + } + return 0; } static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) { struct request_queue *q; - LIST_HEAD(head); - int prev_nr_hw_queues; + int prev_nr_hw_queues = set->nr_hw_queues; + unsigned int memflags; + int i; + struct xarray elv_tbl; + bool queues_frozen = false; lockdep_assert_held(&set->tag_list_lock); @@ -4621,33 +5106,40 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, if (set->nr_maps == 1 && nr_hw_queues == set->nr_hw_queues) return; - list_for_each_entry(q, &set->tag_list, tag_set_list) - blk_mq_freeze_queue(q); + memflags = memalloc_noio_save(); + + xa_init(&elv_tbl); + if (blk_mq_alloc_sched_ctx_batch(&elv_tbl, set) < 0) + goto out_free_ctx; + + if (blk_mq_alloc_sched_res_batch(&elv_tbl, set, nr_hw_queues) < 0) + goto out_free_ctx; + + list_for_each_entry(q, &set->tag_list, tag_set_list) { + blk_mq_debugfs_unregister_hctxs(q); + blk_mq_sysfs_unregister_hctxs(q); + } + /* * Switch IO scheduler to 'none', cleaning up the data associated * with the previous scheduler. We will switch back once we are done * updating the new sw to hw queue mappings. */ list_for_each_entry(q, &set->tag_list, tag_set_list) - if (!blk_mq_elv_switch_none(&head, q)) + if (blk_mq_elv_switch_none(q, &elv_tbl)) goto switch_back; - list_for_each_entry(q, &set->tag_list, tag_set_list) { - blk_mq_debugfs_unregister_hctxs(q); - blk_mq_sysfs_unregister_hctxs(q); - } - - prev_nr_hw_queues = set->nr_hw_queues; - if (blk_mq_realloc_tag_set_tags(set, set->nr_hw_queues, nr_hw_queues) < - 0) - goto reregister; + list_for_each_entry(q, &set->tag_list, tag_set_list) + blk_mq_freeze_queue_nomemsave(q); + queues_frozen = true; + if (blk_mq_realloc_tag_set_tags(set, nr_hw_queues) < 0) + goto switch_back; - set->nr_hw_queues = nr_hw_queues; fallback: blk_mq_update_queue_map(set); list_for_each_entry(q, &set->tag_list, tag_set_list) { - blk_mq_realloc_hw_ctxs(set, q); - blk_mq_update_poll_flag(q); + __blk_mq_realloc_hw_ctxs(set, q); + if (q->nr_hw_queues != set->nr_hw_queues) { int i = prev_nr_hw_queues; @@ -4657,168 +5149,50 @@ fallback: __blk_mq_free_map_and_rqs(set, i); set->nr_hw_queues = prev_nr_hw_queues; - blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); goto fallback; } blk_mq_map_swqueue(q); } +switch_back: + /* The blk_mq_elv_switch_back unfreezes queue for us. */ + list_for_each_entry(q, &set->tag_list, tag_set_list) { + /* switch_back expects queue to be frozen */ + if (!queues_frozen) + blk_mq_freeze_queue_nomemsave(q); + blk_mq_elv_switch_back(q, &elv_tbl); + } -reregister: list_for_each_entry(q, &set->tag_list, tag_set_list) { blk_mq_sysfs_register_hctxs(q); blk_mq_debugfs_register_hctxs(q); + + blk_mq_remove_hw_queues_cpuhp(q); + blk_mq_add_hw_queues_cpuhp(q); } -switch_back: - list_for_each_entry(q, &set->tag_list, tag_set_list) - blk_mq_elv_switch_back(&head, q); +out_free_ctx: + blk_mq_free_sched_ctx_batch(&elv_tbl); + xa_destroy(&elv_tbl); + memalloc_noio_restore(memflags); - list_for_each_entry(q, &set->tag_list, tag_set_list) - blk_mq_unfreeze_queue(q); + /* Free the excess tags when nr_hw_queues shrink. */ + for (i = set->nr_hw_queues; i < prev_nr_hw_queues; i++) + __blk_mq_free_map_and_rqs(set, i); } void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) { + down_write(&set->update_nr_hwq_lock); mutex_lock(&set->tag_list_lock); __blk_mq_update_nr_hw_queues(set, nr_hw_queues); mutex_unlock(&set->tag_list_lock); + up_write(&set->update_nr_hwq_lock); } EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); -/* Enable polling stats and return whether they were already enabled. */ -static bool blk_poll_stats_enable(struct request_queue *q) -{ - if (q->poll_stat) - return true; - - return blk_stats_alloc_enable(q); -} - -static void blk_mq_poll_stats_start(struct request_queue *q) -{ - /* - * We don't arm the callback if polling stats are not enabled or the - * callback is already active. - */ - if (!q->poll_stat || blk_stat_is_active(q->poll_cb)) - return; - - blk_stat_activate_msecs(q->poll_cb, 100); -} - -static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb) -{ - struct request_queue *q = cb->data; - int bucket; - - for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) { - if (cb->stat[bucket].nr_samples) - q->poll_stat[bucket] = cb->stat[bucket]; - } -} - -static unsigned long blk_mq_poll_nsecs(struct request_queue *q, - struct request *rq) -{ - unsigned long ret = 0; - int bucket; - - /* - * If stats collection isn't on, don't sleep but turn it on for - * future users - */ - if (!blk_poll_stats_enable(q)) - return 0; - - /* - * As an optimistic guess, use half of the mean service time - * for this type of request. We can (and should) make this smarter. - * For instance, if the completion latencies are tight, we can - * get closer than just half the mean. This is especially - * important on devices where the completion latencies are longer - * than ~10 usec. We do use the stats for the relevant IO size - * if available which does lead to better estimates. - */ - bucket = blk_mq_poll_stats_bkt(rq); - if (bucket < 0) - return ret; - - if (q->poll_stat[bucket].nr_samples) - ret = (q->poll_stat[bucket].mean + 1) / 2; - - return ret; -} - -static bool blk_mq_poll_hybrid(struct request_queue *q, blk_qc_t qc) -{ - struct blk_mq_hw_ctx *hctx = blk_qc_to_hctx(q, qc); - struct request *rq = blk_qc_to_rq(hctx, qc); - struct hrtimer_sleeper hs; - enum hrtimer_mode mode; - unsigned int nsecs; - ktime_t kt; - - /* - * If a request has completed on queue that uses an I/O scheduler, we - * won't get back a request from blk_qc_to_rq. - */ - if (!rq || (rq->rq_flags & RQF_MQ_POLL_SLEPT)) - return false; - - /* - * If we get here, hybrid polling is enabled. Hence poll_nsec can be: - * - * 0: use half of prev avg - * >0: use this specific value - */ - if (q->poll_nsec > 0) - nsecs = q->poll_nsec; - else - nsecs = blk_mq_poll_nsecs(q, rq); - - if (!nsecs) - return false; - - rq->rq_flags |= RQF_MQ_POLL_SLEPT; - - /* - * This will be replaced with the stats tracking code, using - * 'avg_completion_time / 2' as the pre-sleep target. - */ - kt = nsecs; - - mode = HRTIMER_MODE_REL; - hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode); - hrtimer_set_expires(&hs.timer, kt); - - do { - if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE) - break; - set_current_state(TASK_UNINTERRUPTIBLE); - hrtimer_sleeper_start_expires(&hs, mode); - if (hs.task) - io_schedule(); - hrtimer_cancel(&hs.timer); - mode = HRTIMER_MODE_ABS; - } while (hs.task && !signal_pending(current)); - - __set_current_state(TASK_RUNNING); - destroy_hrtimer_on_stack(&hs.timer); - - /* - * If we sleep, have the caller restart the poll loop to reset the - * state. Like for the other success return cases, the caller is - * responsible for checking if the IO completed. If the IO isn't - * complete, we'll get called again and will go straight to the busy - * poll loop. - */ - return true; -} - -static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie, - struct io_comp_batch *iob, unsigned int flags) +static int blk_hctx_poll(struct request_queue *q, struct blk_mq_hw_ctx *hctx, + struct io_comp_batch *iob, unsigned int flags) { - struct blk_mq_hw_ctx *hctx = blk_qc_to_hctx(q, cookie); long state = get_current_state(); int ret; @@ -4843,16 +5217,31 @@ static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie, return 0; } -int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob, - unsigned int flags) +int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, + struct io_comp_batch *iob, unsigned int flags) { - if (!(flags & BLK_POLL_NOSLEEP) && - q->poll_nsec != BLK_MQ_POLL_CLASSIC) { - if (blk_mq_poll_hybrid(q, cookie)) - return 1; - } - return blk_mq_poll_classic(q, cookie, iob, flags); + if (!blk_mq_can_poll(q)) + return 0; + return blk_hctx_poll(q, q->queue_hw_ctx[cookie], iob, flags); +} + +int blk_rq_poll(struct request *rq, struct io_comp_batch *iob, + unsigned int poll_flags) +{ + struct request_queue *q = rq->q; + int ret; + + if (!blk_rq_is_poll(rq)) + return 0; + if (!percpu_ref_tryget(&q->q_usage_counter)) + return 0; + + ret = blk_hctx_poll(q, rq->mq_hctx, iob, poll_flags); + blk_queue_exit(q); + + return ret; } +EXPORT_SYMBOL_GPL(blk_rq_poll); unsigned int blk_mq_rq_cpu(struct request *rq) { @@ -4862,15 +5251,13 @@ EXPORT_SYMBOL(blk_mq_rq_cpu); void blk_mq_cancel_work_sync(struct request_queue *q) { - if (queue_is_mq(q)) { - struct blk_mq_hw_ctx *hctx; - unsigned long i; + struct blk_mq_hw_ctx *hctx; + unsigned long i; - cancel_delayed_work_sync(&q->requeue_work); + cancel_delayed_work_sync(&q->requeue_work); - queue_for_each_hw_ctx(q, hctx, i) - cancel_delayed_work_sync(&hctx->run_work); - } + queue_for_each_hw_ctx(q, hctx, i) + cancel_delayed_work_sync(&hctx->run_work); } static int __init blk_mq_init(void) @@ -4879,6 +5266,9 @@ static int __init blk_mq_init(void) for_each_possible_cpu(i) init_llist_head(&per_cpu(blk_cpu_done, i)); + for_each_possible_cpu(i) + INIT_CSD(&per_cpu(blk_cpu_csd, i), + __blk_mq_complete_request_remote, NULL); open_softirq(BLOCK_SOFTIRQ, blk_done_softirq); cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD, |