block: mq-deadline: Handle requeued requests correctly

Start dispatching from the start of a zone instead of from the starting
position of the most recently dispatched request.

If a zoned write is requeued with an LBA that is lower than already
inserted zoned writes, make sure that it is submitted first.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230517174230.897144-11-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Bart Van Assche 2023-05-17 10:42:28 -07:00 committed by Jens Axboe
parent 83c46ed675
commit 0effb390c4

View File

@ -156,13 +156,28 @@ deadline_latter_request(struct request *rq)
return NULL; return NULL;
} }
/* Return the first request for which blk_rq_pos() >= pos. */ /*
* Return the first request for which blk_rq_pos() >= @pos. For zoned devices,
* return the first request after the start of the zone containing @pos.
*/
static inline struct request *deadline_from_pos(struct dd_per_prio *per_prio, static inline struct request *deadline_from_pos(struct dd_per_prio *per_prio,
enum dd_data_dir data_dir, sector_t pos) enum dd_data_dir data_dir, sector_t pos)
{ {
struct rb_node *node = per_prio->sort_list[data_dir].rb_node; struct rb_node *node = per_prio->sort_list[data_dir].rb_node;
struct request *rq, *res = NULL; struct request *rq, *res = NULL;
if (!node)
return NULL;
rq = rb_entry_rq(node);
/*
* A zoned write may have been requeued with a starting position that
* is below that of the most recently dispatched request. Hence, for
* zoned writes, start searching from the start of a zone.
*/
if (blk_rq_is_seq_zoned_write(rq))
pos -= round_down(pos, rq->q->limits.chunk_sectors);
while (node) { while (node) {
rq = rb_entry_rq(node); rq = rb_entry_rq(node);
if (blk_rq_pos(rq) >= pos) { if (blk_rq_pos(rq) >= pos) {
@ -806,6 +821,8 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
list_add(&rq->queuelist, &per_prio->dispatch); list_add(&rq->queuelist, &per_prio->dispatch);
rq->fifo_time = jiffies; rq->fifo_time = jiffies;
} else { } else {
struct list_head *insert_before;
deadline_add_rq_rb(per_prio, rq); deadline_add_rq_rb(per_prio, rq);
if (rq_mergeable(rq)) { if (rq_mergeable(rq)) {
@ -818,7 +835,20 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
* set expire time and add to fifo list * set expire time and add to fifo list
*/ */
rq->fifo_time = jiffies + dd->fifo_expire[data_dir]; rq->fifo_time = jiffies + dd->fifo_expire[data_dir];
list_add_tail(&rq->queuelist, &per_prio->fifo_list[data_dir]); insert_before = &per_prio->fifo_list[data_dir];
#ifdef CONFIG_BLK_DEV_ZONED
/*
* Insert zoned writes such that requests are sorted by
* position per zone.
*/
if (blk_rq_is_seq_zoned_write(rq)) {
struct request *rq2 = deadline_latter_request(rq);
if (rq2 && blk_rq_zone_no(rq2) == blk_rq_zone_no(rq))
insert_before = &rq2->queuelist;
}
#endif
list_add_tail(&rq->queuelist, insert_before);
} }
} }