Commit b2c45ced authored by Chaitanya Kulkarni's avatar Chaitanya Kulkarni Committed by Jens Axboe
Browse files

block: move bio queue-transition flag fixups into blk_steal_bios() 



blk_steal_bios() transfers bios from a request to a bio_list when the
request is requeued to a different queue. The NVMe multipath failover
path (nvme_failover_req) currently open-codes clearing of REQ_POLLED,
bi_cookie, and REQ_NOWAIT on each bio before calling blk_steal_bios().

Move these fixups into blk_steal_bios() itself so that any caller
automatically gets correct flag state when bios cross queue boundaries.
Simplify nvme_failover_req() accordingly.

Signed-off-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260226031243.87200-2-kch@nvidia.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 89d10b78

block/blk-mq.c

+17 −0
Original line number Diff line number Diff line
@@ -3424,6 +3424,23 @@ EXPORT_SYMBOL_GPL(blk_rq_prep_clone); 
 */

void blk_steal_bios(struct bio_list *list, struct request *rq)

{

	struct bio *bio;



	for (bio = rq->bio; bio; bio = bio->bi_next) {

		if (bio->bi_opf & REQ_POLLED) {

			bio->bi_opf &= ~REQ_POLLED;

			bio->bi_cookie = BLK_QC_T_NONE;

		}

		/*

		 * The alternate request queue that we may end up submitting

		 * the bio to may be frozen temporarily, in this case REQ_NOWAIT

		 * will fail the I/O immediately with EAGAIN to the issuer.

		 * We are not in the issuer context which cannot block. Clear

		 * the flag to avoid spurious EAGAIN I/O failures.

		 */

		bio->bi_opf &= ~REQ_NOWAIT;

	}



	if (rq->bio) {

		if (list->tail)

			list->tail->bi_next = rq->bio;

drivers/nvme/host/multipath.c

+1 −14
Original line number Diff line number Diff line
@@ -154,21 +154,8 @@ void nvme_failover_req(struct request *req) 
	}



	spin_lock_irqsave(&ns->head->requeue_lock, flags);

	for (bio = req->bio; bio; bio = bio->bi_next) {

	for (bio = req->bio; bio; bio = bio->bi_next)

		bio_set_dev(bio, ns->head->disk->part0);

		if (bio->bi_opf & REQ_POLLED) {

			bio->bi_opf &= ~REQ_POLLED;

			bio->bi_cookie = BLK_QC_T_NONE;

		}

		/*

		 * The alternate request queue that we may end up submitting

		 * the bio to may be frozen temporarily, in this case REQ_NOWAIT

		 * will fail the I/O immediately with EAGAIN to the issuer.

		 * We are not in the issuer context which cannot block. Clear

		 * the flag to avoid spurious EAGAIN I/O failures.

		 */

		bio->bi_opf &= ~REQ_NOWAIT;

	}

	blk_steal_bios(&ns->head->requeue_list, req);

	spin_unlock_irqrestore(&ns->head->requeue_lock, flags);