Commit ea435e1b authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: add a poll_fn callback to struct request_queue 



That we we can also poll non blk-mq queues.  Mostly needed for
the NVMe multipath code, but could also be useful elsewhere.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8ddcd653

block/blk-core.c

+11 −0
Original line number Diff line number Diff line
@@ -2321,6 +2321,17 @@ blk_qc_t submit_bio(struct bio *bio) 
}

EXPORT_SYMBOL(submit_bio);



bool blk_poll(struct request_queue *q, blk_qc_t cookie)

{

	if (!q->poll_fn || !blk_qc_t_valid(cookie))

		return false;



	if (current->plug)

		blk_flush_plug_list(current->plug, false);

	return q->poll_fn(q, cookie);

}

EXPORT_SYMBOL_GPL(blk_poll);



/**

 * blk_cloned_rq_check_limits - Helper function to check a cloned request

 *                              for new the queue limits

block/blk-mq.c

+5 −9
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include "blk-wbt.h"

#include "blk-mq-sched.h"



static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie);

static void blk_mq_poll_stats_start(struct request_queue *q);

static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
@@ -2499,6 +2500,8 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, 
	spin_lock_init(&q->requeue_lock);



	blk_queue_make_request(q, blk_mq_make_request);

	if (q->mq_ops->poll)

		q->poll_fn = blk_mq_poll;



	/*

	 * Do this after blk_queue_make_request() overrides it...
@@ -2961,20 +2964,14 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) 
	return false;

}



bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)

static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)

{

	struct blk_mq_hw_ctx *hctx;

	struct blk_plug *plug;

	struct request *rq;



	if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) ||

	    !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))

	if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))

		return false;



	plug = current->plug;

	if (plug)

		blk_flush_plug_list(plug, false);



	hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];

	if (!blk_qc_t_is_internal(cookie))

		rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
@@ -2992,7 +2989,6 @@ bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) 


	return __blk_mq_poll(hctx, rq);

}

EXPORT_SYMBOL_GPL(blk_mq_poll);



static int __init blk_mq_init(void)

{

drivers/nvme/target/io-cmd.c

+1 −1
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ static void nvmet_execute_rw(struct nvmet_req *req) 


	cookie = submit_bio(bio);



	blk_mq_poll(bdev_get_queue(req->ns->bdev), cookie);

	blk_poll(bdev_get_queue(req->ns->bdev), cookie);

}



static void nvmet_execute_flush(struct nvmet_req *req)

fs/block_dev.c

+2 −2
Original line number Diff line number Diff line
@@ -237,7 +237,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, 
		if (!READ_ONCE(bio.bi_private))

			break;

		if (!(iocb->ki_flags & IOCB_HIPRI) ||

		    !blk_mq_poll(bdev_get_queue(bdev), qc))

		    !blk_poll(bdev_get_queue(bdev), qc))

			io_schedule();

	}

	__set_current_state(TASK_RUNNING);
@@ -402,7 +402,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) 
			break;



		if (!(iocb->ki_flags & IOCB_HIPRI) ||

		    !blk_mq_poll(bdev_get_queue(bdev), qc))

		    !blk_poll(bdev_get_queue(bdev), qc))

			io_schedule();

	}

	__set_current_state(TASK_RUNNING);

fs/direct-io.c

+1 −1
Original line number Diff line number Diff line
@@ -486,7 +486,7 @@ static struct bio *dio_await_one(struct dio *dio) 
		dio->waiter = current;

		spin_unlock_irqrestore(&dio->bio_lock, flags);

		if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||

		    !blk_mq_poll(dio->bio_disk->queue, dio->bio_cookie))

		    !blk_poll(dio->bio_disk->queue, dio->bio_cookie))

			io_schedule();

		/* wake up sets us TASK_RUNNING */

		spin_lock_irqsave(&dio->bio_lock, flags);

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