Commit 69fe0f29 authored by Ming Lei's avatar Ming Lei Committed by Mike Snitzer
Browse files

block: add ->poll_bio to block_device_operations 



Prepare for supporting IO polling for bio-based driver.

Add ->poll_bio callback so that bio-based driver can provide their own
logic for polling bio.

Also fix ->submit_bio_bio typo in comment block above
__submit_bio_noacct.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 168678d7

block/blk-core.c

+9 −5
Original line number Diff line number Diff line
@@ -708,7 +708,7 @@ static void __submit_bio(struct bio *bio) 
 *

 * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio.

 * bio_list_on_stack[1] contains bios that were submitted before the current

 *	->submit_bio_bio, but that haven't been processed yet.

 *	->submit_bio, but that haven't been processed yet.

 */

static void __submit_bio_noacct(struct bio *bio)

{
@@ -975,7 +975,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) 
{

	struct request_queue *q = bdev_get_queue(bio->bi_bdev);

	blk_qc_t cookie = READ_ONCE(bio->bi_cookie);

	int ret;

	int ret = 0;



	if (cookie == BLK_QC_T_NONE ||

	    !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
@@ -985,10 +985,14 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) 


	if (blk_queue_enter(q, BLK_MQ_REQ_NOWAIT))

		return 0;

	if (WARN_ON_ONCE(!queue_is_mq(q)))

		ret = 0;	/* not yet implemented, should not happen */

	else

	if (queue_is_mq(q)) {

		ret = blk_mq_poll(q, cookie, iob, flags);

	} else {

		struct gendisk *disk = q->disk;



		if (disk && disk->fops->poll_bio)

			ret = disk->fops->poll_bio(bio, iob, flags);

	}

	blk_queue_exit(q);

	return ret;

}

block/genhd.c

+4 −0
Original line number Diff line number Diff line
@@ -410,6 +410,10 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, 
	struct device *ddev = disk_to_dev(disk);

	int ret;



	/* Only makes sense for bio-based to set ->poll_bio */

	if (queue_is_mq(disk->queue) && disk->fops->poll_bio)

		return -EINVAL;



	/*

	 * The disk queue should now be all set with enough information about

	 * the device for the elevator code to pick an adequate default

include/linux/blkdev.h

+2 −0
Original line number Diff line number Diff line
@@ -1455,6 +1455,8 @@ enum blk_unique_id { 


struct block_device_operations {

	void (*submit_bio)(struct bio *bio);

	int (*poll_bio)(struct bio *bio, struct io_comp_batch *iob,

			unsigned int flags);

	int (*open) (struct block_device *, fmode_t);

	void (*release) (struct gendisk *, fmode_t);

	int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);