[PATCH v1 2/3] nvme: Use blk-mq helper for IO termination

[Keith Busch]

On Thu, Feb 04, 2016 at 02:28:24PM +0000, Wenbo Wang wrote:
> Is the following execution valid?
> 
> 1. request A is linked in q->request_list

q->request_list? Do you mean q->requeue_list?

> 2. device reset
> 3. all requests (including request A) are cancelled by nvme_dev_disable()->nvme_clear_queue()

If the request is on some list owned by the request_queue, it was not
started by the driver, and nvme_clear_queue doesn't do anything to it.

> 4. device restarted
> 5. flush q->request_list, and request A is again running in queue_rq.         <-- since request A has been cancelled, it shall not be running again

Request A was not cancelled if it was never started. It will be submitted
when the driver restarts the queues h/w contexts.

Cancelling a command with the controller does not mean ending the request
in the block layer.