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.
Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
block/mq-deadline.c | 34 ++++++++++++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index b482b707cb37..6c196182f86c 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -156,13 +156,28 @@ deadline_latter_request(struct request *rq)
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 highest zone start <= @pos.
+ */
static inline struct request *deadline_from_pos(struct dd_per_prio *per_prio,
enum dd_data_dir data_dir, sector_t pos)
{
struct rb_node *node = per_prio->sort_list[data_dir].rb_node;
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) {
rq = rb_entry_rq(node);
if (blk_rq_pos(rq) >= pos) {
@@ -812,6 +827,8 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
list_add(&rq->queuelist, &per_prio->dispatch);
rq->fifo_time = jiffies;
} else {
+ struct list_head *insert_before;
+
deadline_add_rq_rb(per_prio, rq);
if (rq_mergeable(rq)) {
@@ -824,7 +841,20 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
* set expire time and add to fifo list
*/
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);
}
}
