Commit a036e698 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe
Browse files

block: mq-deadline: Fix handling of at-head zoned writes 



Before dispatching a zoned write from the FIFO list, check whether there
are any zoned writes in the RB-tree with a lower LBA for the same zone.
This patch ensures that zoned writes happen in order even if at_head is
set for some writes for a zone and not for others.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230517174230.897144-12-bvanassche@acm.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0effb390

block/mq-deadline.c

+7 −2
Original line number Diff line number Diff line
@@ -346,7 +346,7 @@ static struct request * 
deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio,

		      enum dd_data_dir data_dir)

{

	struct request *rq;

	struct request *rq, *rb_rq, *next;

	unsigned long flags;



	if (list_empty(&per_prio->fifo_list[data_dir]))
@@ -364,7 +364,12 @@ deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio, 
	 * zones and these zones are unlocked.

	 */

	spin_lock_irqsave(&dd->zone_lock, flags);

	list_for_each_entry(rq, &per_prio->fifo_list[DD_WRITE], queuelist) {

	list_for_each_entry_safe(rq, next, &per_prio->fifo_list[DD_WRITE],

				 queuelist) {

		/* Check whether a prior request exists for the same zone. */

		rb_rq = deadline_from_pos(per_prio, data_dir, blk_rq_pos(rq));

		if (rb_rq && blk_rq_pos(rb_rq) < blk_rq_pos(rq))

			rq = rb_rq;

		if (blk_req_can_dispatch_to_zone(rq) &&

		    (blk_queue_nonrot(rq->q) ||

		     !deadline_is_seq_write(dd, rq)))