From 568f2700657794b8258e72983ba508793a658942 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Mon, 6 Jul 2020 22:41:11 +0800 Subject: [PATCH] blk-mq: centralise related handling into blk_mq_get_driver_tag Move .nr_active update and request assignment into blk_mq_get_driver_tag(), all are good to do during getting driver tag. Meantime blk-flush related code is simplified and flush request needn't to update the request table manually any more. Signed-off-by: Ming Lei Cc: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-flush.c | 14 ++++---------- block/blk-mq-tag.h | 12 ------------ block/blk-mq.c | 31 +++++++++++++++---------------- block/blk.h | 5 ----- 4 files changed, 19 insertions(+), 43 deletions(-) diff --git a/block/blk-flush.c b/block/blk-flush.c index 15ae0155ec07..71c7f520e040 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -219,7 +219,6 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error) struct request *rq, *n; unsigned long flags = 0; struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx); - struct blk_mq_hw_ctx *hctx; blk_account_io_flush(flush_rq); @@ -235,13 +234,11 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error) if (fq->rq_status != BLK_STS_OK) error = fq->rq_status; - hctx = flush_rq->mq_hctx; if (!q->elevator) { - blk_mq_tag_set_rq(hctx, flush_rq->tag, fq->orig_rq); - flush_rq->tag = -1; + flush_rq->tag = BLK_MQ_NO_TAG; } else { blk_mq_put_driver_tag(flush_rq); - flush_rq->internal_tag = -1; + flush_rq->internal_tag = BLK_MQ_NO_TAG; } running = &fq->flush_queue[fq->flush_running_idx]; @@ -316,13 +313,10 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq, flush_rq->mq_ctx = first_rq->mq_ctx; flush_rq->mq_hctx = first_rq->mq_hctx; - if (!q->elevator) { - fq->orig_rq = first_rq; + if (!q->elevator) flush_rq->tag = first_rq->tag; - blk_mq_tag_set_rq(flush_rq->mq_hctx, first_rq->tag, flush_rq); - } else { + else flush_rq->internal_tag = first_rq->internal_tag; - } flush_rq->cmd_flags = REQ_OP_FLUSH | REQ_PREFLUSH; flush_rq->cmd_flags |= (flags & REQ_DRV) | (flags & REQ_FAILFAST_MASK); diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 3945c7f5b944..b1acac518c4e 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -101,18 +101,6 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, return atomic_read(&hctx->nr_active) < depth; } -/* - * This helper should only be used for flush request to share tag - * with the request cloned from, and both the two requests can't be - * in flight at the same time. The caller has to make sure the tag - * can't be freed. - */ -static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx, - unsigned int tag, struct request *rq) -{ - hctx->tags->rqs[tag] = rq; -} - static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags, unsigned int tag) { diff --git a/block/blk-mq.c b/block/blk-mq.c index 89c83fa97ba0..b6dd080d3962 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -277,26 +277,20 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, { struct blk_mq_tags *tags = blk_mq_tags_from_data(data); struct request *rq = tags->static_rqs[tag]; - req_flags_t rq_flags = 0; if (data->q->elevator) { rq->tag = BLK_MQ_NO_TAG; rq->internal_tag = tag; } else { - if (data->hctx->flags & BLK_MQ_F_TAG_SHARED) { - rq_flags = RQF_MQ_INFLIGHT; - atomic_inc(&data->hctx->nr_active); - } rq->tag = tag; rq->internal_tag = BLK_MQ_NO_TAG; - data->hctx->tags->rqs[rq->tag] = rq; } /* csd/requeue_work/fifo_time is initialized before use */ rq->q = data->q; rq->mq_ctx = data->ctx; rq->mq_hctx = data->hctx; - rq->rq_flags = rq_flags; + rq->rq_flags = 0; rq->cmd_flags = data->cmd_flags; if (data->flags & BLK_MQ_REQ_PREEMPT) rq->rq_flags |= RQF_PREEMPT; @@ -1105,9 +1099,10 @@ static bool __blk_mq_get_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; - bool shared = blk_mq_tag_busy(rq->mq_hctx); int tag; + blk_mq_tag_busy(rq->mq_hctx); + if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { bt = &rq->mq_hctx->tags->breserved_tags; tag_offset = 0; @@ -1120,19 +1115,23 @@ static bool __blk_mq_get_driver_tag(struct request *rq) return false; rq->tag = tag + tag_offset; - if (shared) { - rq->rq_flags |= RQF_MQ_INFLIGHT; - atomic_inc(&rq->mq_hctx->nr_active); - } - rq->mq_hctx->tags->rqs[rq->tag] = rq; return true; } static bool blk_mq_get_driver_tag(struct request *rq) { - if (rq->tag != BLK_MQ_NO_TAG) - return true; - return __blk_mq_get_driver_tag(rq); + struct blk_mq_hw_ctx *hctx = rq->mq_hctx; + + if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_get_driver_tag(rq)) + return false; + + if ((hctx->flags & BLK_MQ_F_TAG_SHARED) && + !(rq->rq_flags & RQF_MQ_INFLIGHT)) { + rq->rq_flags |= RQF_MQ_INFLIGHT; + atomic_inc(&hctx->nr_active); + } + hctx->tags->rqs[rq->tag] = rq; + return true; } static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, diff --git a/block/blk.h b/block/blk.h index 94f7c084f68f..9dcf51c94096 100644 --- a/block/blk.h +++ b/block/blk.h @@ -25,11 +25,6 @@ struct blk_flush_queue { struct list_head flush_data_in_flight; struct request *flush_rq; - /* - * flush_rq shares tag with this rq, both can't be active - * at the same time - */ - struct request *orig_rq; struct lock_class_key key; spinlock_t mq_flush_lock; };