Commit 5a9d041b authored by Jens Axboe's avatar Jens Axboe
Browse files

block: move io_context creation into where it's needed 



The only user of the io_context for IO is BFQ, yet we put the checking
and logic of it into the normal IO path.

Put the creation into blk_mq_sched_assign_ioc(), and have BFQ use that
helper.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 48b5c1fb

block/bfq-iosched.c

+2 −0
Original line number Diff line number Diff line
@@ -6573,6 +6573,8 @@ static struct bfq_queue *bfq_get_bfqq_handle_split(struct bfq_data *bfqd, 
 */

static void bfq_prepare_request(struct request *rq)

{

	blk_mq_sched_assign_ioc(rq);



	/*

	 * Regardless of whether we have an icq attached, we have to

	 * clear the scheduler pointers, as they might point to

block/blk-core.c

+0 −9
Original line number Diff line number Diff line
@@ -750,15 +750,6 @@ noinline_for_stack bool submit_bio_checks(struct bio *bio) 
		break;

	}



	/*

	 * Various block parts want %current->io_context, so allocate it up

	 * front rather than dealing with lots of pain to allocate it only

	 * where needed. This may fail and the block layer knows how to live

	 * with it.

	 */

	if (unlikely(!current->io_context))

		create_task_io_context(current, GFP_ATOMIC, q->node);



	if (blk_throtl_bio(bio))

		return false;

block/blk-mq-sched.c

+5 −0
Original line number Diff line number Diff line
@@ -24,6 +24,10 @@ void blk_mq_sched_assign_ioc(struct request *rq) 
	struct io_context *ioc;

	struct io_cq *icq;



	/* create task io_context, if we don't have one already */

	if (unlikely(!current->io_context))

		create_task_io_context(current, GFP_ATOMIC, q->node);



	/*

	 * May not have an IO context if it's a passthrough request

	 */
@@ -43,6 +47,7 @@ void blk_mq_sched_assign_ioc(struct request *rq) 
	get_io_context(icq->ioc);

	rq->elv.icq = icq;

}

EXPORT_SYMBOL_GPL(blk_mq_sched_assign_ioc);



/*

 * Mark a hardware queue as needing a restart. For shared queues, maintain

block/blk-mq.c

+0 −3
Original line number Diff line number Diff line
@@ -406,9 +406,6 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, 


		if (!op_is_flush(data->cmd_flags) &&

		    e->type->ops.prepare_request) {

			if (e->type->icq_cache)

				blk_mq_sched_assign_ioc(rq);



			e->type->ops.prepare_request(rq);

			rq->rq_flags |= RQF_ELVPRIV;

		}