Commit 781dd830 authored by Jens Axboe's avatar Jens Axboe
Browse files

block: move RQF_ELV setting into allocators 



It's not safe to do this before blk_queue_enter(), as the scheduler state
could have changed in between. Hence move the RQF_ELV setting into the
allocators, where we know the queue is already entered.

Suggested-by: default avatarMing Lei <ming.lei@redhat.com>
Reported-by: default avatarYi Zhang <yi.zhang@redhat.com>
Reported-by: default avatarSteffen Maier <maier@linux.ibm.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a1c2f7e7

block/blk-mq.c

+8 −6
Original line number Diff line number Diff line
@@ -419,7 +419,6 @@ __blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data, 
static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data)

{

	struct request_queue *q = data->q;

	struct elevator_queue *e = q->elevator;

	u64 alloc_time_ns = 0;

	struct request *rq;

	unsigned int tag;
@@ -431,7 +430,11 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) 
	if (data->cmd_flags & REQ_NOWAIT)

		data->flags |= BLK_MQ_REQ_NOWAIT;



	if (e) {

	if (q->elevator) {

		struct elevator_queue *e = q->elevator;



		data->rq_flags |= RQF_ELV;



		/*

		 * Flush/passthrough requests are special and go directly to the

		 * dispatch list. Don't include reserved tags in the
@@ -447,7 +450,7 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) 
retry:

	data->ctx = blk_mq_get_ctx(q);

	data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx);

	if (!e)

	if (!(data->rq_flags & RQF_ELV))

		blk_mq_tag_busy(data->hctx);



	/*
@@ -490,7 +493,6 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, 
		.q		= q,

		.flags		= flags,

		.cmd_flags	= op,

		.rq_flags	= q->elevator ? RQF_ELV : 0,

		.nr_tags	= 1,

	};

	struct request *rq;
@@ -520,7 +522,6 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, 
		.q		= q,

		.flags		= flags,

		.cmd_flags	= op,

		.rq_flags	= q->elevator ? RQF_ELV : 0,

		.nr_tags	= 1,

	};

	u64 alloc_time_ns = 0;
@@ -561,6 +562,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, 


	if (!q->elevator)

		blk_mq_tag_busy(data.hctx);

	else

		data.rq_flags |= RQF_ELV;



	ret = -EWOULDBLOCK;

	tag = blk_mq_get_tag(&data);
@@ -2515,7 +2518,6 @@ void blk_mq_submit_bio(struct bio *bio) 
			.q		= q,

			.nr_tags	= 1,

			.cmd_flags	= bio->bi_opf,

			.rq_flags	= q->elevator ? RQF_ELV : 0,

		};



		if (plug) {