Re: [PATCH 2/2] blk-mq: sync the update nr_hw_queues with part_in_flight

[Ming Lei]

On Wed, Aug 15, 2018 at 3:25 PM, Jianchao Wang
<jianchao.w.wang@xxxxxxxxxx> wrote:
> For blk-mq, part_in_flight/rw will invoke blk_mq_in_flight/rw to
> account the inflight requests. It will access the queue_hw_ctx and
> nr_hw_queues w/o any protection. When updating nr_hw_queues and
> blk_mq_in_flight/rw occur concurrently, panic comes up.

When updating nr_hw_queues, all queues are frozen, and there shouldn't
be any inflight requests, so there shouldn't be such issue.


Thanks,
Ming Lei