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blk-mq: fix nr_requests wrong value when modify it from sysfs

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if blk-mq use "none" io scheduler, nr_request get a wrong value when
input a number > tag_set->queue_depth. blk_mq_tag_update_depth will get
the smaller one min(nr, set->queue_depth), and then q->nr_request get a
wrong value.

Reproduce:

echo none > /sys/block/nvme0n1/queue/scheduler
echo 1000000 > /sys/block/nvme0n1/queue/nr_requests
cat /sys/block/nvme0n1/queue/nr_requests
1000000

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
weiping zhang 2017-09-22 23:36:28 +08:00 committed by Jens Axboe
parent a116895fc7
commit c2e82a2348
1 changed files with 1 additions and 2 deletions
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3
block/blk-mq.c
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@ -2743,8 +2743,7 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
* queue depth. This is similar to what the old code would do.
*/
if (!hctx->sched_tags) {
ret = blk_mq_tag_update_depth(hctx, &hctx->tags,
min(nr, set->queue_depth),
ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr,
false);
} else {
ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,