On 5/17/23 00:33, Bart Van Assche wrote:
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: Christoph Hellwig <hch@xxxxxx> Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> Cc: Ming Lei <ming.lei@xxxxxxxxxx> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> --- block/mq-deadline.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/block/mq-deadline.c b/block/mq-deadline.c index 059727fa4b98..67989f8d29a5 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -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)))
Similar concern here; we'll have to traverse the entire tree here. But if that's of no concern... Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
