Commit 6abc4946 authored by Konstantin Khlebnikov's avatar Konstantin Khlebnikov Committed by Jens Axboe
Browse files

dm: add support for REQ_NOWAIT and enable it for linear target 



Add DM target feature flag DM_TARGET_NOWAIT which advertises that
target works with REQ_NOWAIT bios.

Add dm_table_supports_nowait() and update dm_table_set_restrictions()
to set/clear QUEUE_FLAG_NOWAIT accordingly.

Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 021a2446

drivers/md/dm-linear.c

+3 −2
Original line number Diff line number Diff line
@@ -228,10 +228,11 @@ static struct target_type linear_target = { 
	.name   = "linear",

	.version = {1, 4, 0},

#ifdef CONFIG_BLK_DEV_ZONED

	.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_ZONED_HM,

	.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |

		    DM_TARGET_ZONED_HM,

	.report_zones = linear_report_zones,

#else

	.features = DM_TARGET_PASSES_INTEGRITY,

	.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT,

#endif

	.module = THIS_MODULE,

	.ctr    = linear_ctr,

drivers/md/dm-table.c

+32 −0
Original line number Diff line number Diff line
@@ -1748,6 +1748,33 @@ static bool dm_table_supports_write_zeroes(struct dm_table *t) 
	return true;

}



static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,

				     sector_t start, sector_t len, void *data)

{

	struct request_queue *q = bdev_get_queue(dev->bdev);



	return q && !blk_queue_nowait(q);

}



static bool dm_table_supports_nowait(struct dm_table *t)

{

	struct dm_target *ti;

	unsigned i = 0;



	while (i < dm_table_get_num_targets(t)) {

		ti = dm_table_get_target(t, i++);



		if (!dm_target_supports_nowait(ti->type))

			return false;



		if (!ti->type->iterate_devices ||

		    ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))

			return false;

	}



	return true;

}



static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,

				      sector_t start, sector_t len, void *data)

{
@@ -1850,6 +1877,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 
	 */

	q->limits = *limits;



	if (dm_table_supports_nowait(t))

		blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);

	else

		blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);



	if (!dm_table_supports_discards(t)) {

		blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);

		/* Must also clear discard limits... */

drivers/md/dm.c

+3 −1
Original line number Diff line number Diff line
@@ -1802,7 +1802,9 @@ static blk_qc_t dm_submit_bio(struct bio *bio) 
	if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {

		dm_put_live_table(md, srcu_idx);



		if (!(bio->bi_opf & REQ_RAHEAD))

		if (bio->bi_opf & REQ_NOWAIT)

			bio_wouldblock_error(bio);

		else if (!(bio->bi_opf & REQ_RAHEAD))

			queue_io(md, bio);

		else

			bio_io_error(bio);

include/linux/device-mapper.h

+6 −0
Original line number Diff line number Diff line
@@ -252,6 +252,12 @@ struct target_type { 
#define DM_TARGET_ZONED_HM		0x00000040

#define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)



/*

 * A target handles REQ_NOWAIT

 */

#define DM_TARGET_NOWAIT		0x00000080

#define dm_target_supports_nowait(type) ((type)->features & DM_TARGET_NOWAIT)



struct dm_target {

	struct dm_table *table;

	struct target_type *type;

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