Commit 021a2446 authored by Mike Snitzer's avatar Mike Snitzer Committed by Jens Axboe
Browse files

block: add QUEUE_FLAG_NOWAIT 



Add QUEUE_FLAG_NOWAIT to allow a block device to advertise support for
REQ_NOWAIT. Bio-based devices may set QUEUE_FLAG_NOWAIT where
applicable.

Update QUEUE_FLAG_MQ_DEFAULT to include QUEUE_FLAG_NOWAIT.  Also
update submit_bio_checks() to verify it is set for REQ_NOWAIT bios.

Reported-by: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Suggested-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 700cd59d

block/blk-core.c

+2 −2
Original line number Diff line number Diff line
@@ -814,9 +814,9 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio) 


	/*

	 * For a REQ_NOWAIT based request, return -EOPNOTSUPP

	 * if queue is not a request based queue.

	 * if queue does not support NOWAIT.

	 */

	if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_mq(q))

	if ((bio->bi_opf & REQ_NOWAIT) && !blk_queue_nowait(q))

		goto not_supported;



	if (should_fail_bio(bio))

include/linux/blkdev.h

+5 −2
Original line number Diff line number Diff line
@@ -620,9 +620,11 @@ struct request_queue { 
#define QUEUE_FLAG_ZONE_RESETALL 26	/* supports Zone Reset All */

#define QUEUE_FLAG_RQ_ALLOC_TIME 27	/* record rq->alloc_time_ns */

#define QUEUE_FLAG_HCTX_ACTIVE	28	/* at least one blk-mq hctx is active */

#define QUEUE_FLAG_NOWAIT       29	/* device supports NOWAIT */



#define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\

				 (1 << QUEUE_FLAG_SAME_COMP))

				 (1 << QUEUE_FLAG_SAME_COMP) |		\

				 (1 << QUEUE_FLAG_NOWAIT))



void blk_queue_flag_set(unsigned int flag, struct request_queue *q);

void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
@@ -664,6 +666,7 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q); 
#define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)

#define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)

#define blk_queue_registered(q)	test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)

#define blk_queue_nowait(q)	test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags)



extern void blk_set_pm_only(struct request_queue *q);

extern void blk_clear_pm_only(struct request_queue *q);

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