Dispatch may still be in-progress after queue is frozen, so we have to quiesce queue before switching IO scheduler and updating nr_requests.
This reverts commit 7a148c2fcff8330(block: don't call blk_mq_quiesce_queue() after queue is frozen) basically. Fixes: 7a148c2fcff83309(block: don't call blk_mq_quiesce_queue() after queue is frozen) Signed-off-by: Ming Lei <[email protected]> --- block/blk-mq.c | 2 ++ block/elevator.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index c501cbd0de93..88c3e4c89052 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2665,6 +2665,7 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) return -EINVAL; blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); ret = 0; queue_for_each_hw_ctx(q, hctx, i) { @@ -2688,6 +2689,7 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) if (!ret) q->nr_requests = nr; + blk_mq_unquiesce_queue(q); blk_mq_unfreeze_queue(q); return ret; diff --git a/block/elevator.c b/block/elevator.c index 7bda083d5968..138faeb08a7c 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -968,6 +968,7 @@ static int elevator_switch_mq(struct request_queue *q, int ret; blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); if (q->elevator) { if (q->elevator->registered) @@ -994,6 +995,7 @@ static int elevator_switch_mq(struct request_queue *q, blk_add_trace_msg(q, "elv switch: none"); out: + blk_mq_unquiesce_queue(q); blk_mq_unfreeze_queue(q); return ret; } -- 2.9.5
