Commit 568f2700 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

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: default avatarMing Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 7bf13729

block/blk-flush.c

+4 −10
Original line number Diff line number Diff line
@@ -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);

block/blk-mq-tag.h

+0 −12
Original line number Diff line number Diff line
@@ -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)

{

block/blk-mq.c

+15 −16
Original line number Diff line number Diff line
@@ -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)

	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;

	return __blk_mq_get_driver_tag(rq);

}



static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,

block/blk.h

+0 −5
Original line number Diff line number Diff line
@@ -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;

};

CRA Git | Maintained and supported by SUSTech CRA and CCSE