Hi Keith
Thanks for your kindly response and directive.
On 01/19/2018 12:59 PM, Keith Busch wrote:
> On Thu, Jan 18, 2018 at 06:10:02PM +0800, Jianchao Wang wrote:
>> + * - When the ctrl.state is NVME_CTRL_RESETTING, the expired
>> + * request should come from the previous work and we handle
>> + * it as nvme_cancel_request.
>> + * - When the ctrl.state is NVME_CTRL_RECONNECTING, the expired
>> + * request should come from the initializing procedure such as
>> + * setup io queues, because all the previous outstanding
>> + * requests should have been cancelled.
>> */
>> - if (dev->ctrl.state == NVME_CTRL_RESETTING) {
>> - dev_warn(dev->ctrl.device,
>> - "I/O %d QID %d timeout, disable controller\n",
>> - req->tag, nvmeq->qid);
>> - nvme_dev_disable(dev, false);
>> + switch (dev->ctrl.state) {
>> + case NVME_CTRL_RESETTING:
>> + nvme_req(req)->status = NVME_SC_ABORT_REQ;
>> + return BLK_EH_HANDLED;
>> + case NVME_CTRL_RECONNECTING:
>> + WARN_ON_ONCE(nvmeq->qid);
>> nvme_req(req)->flags |= NVME_REQ_CANCELLED;
>> return BLK_EH_HANDLED;
>> + default:
>> + break;
>> }
>
> The driver may be giving up on the command here, but that doesn't mean
> the controller has. We can't just end the request like this because that
> will release the memory the controller still owns. We must wait until
> after nvme_dev_disable clears bus master because we can't say for sure
> the controller isn't going to write to that address right after we end
> the request.
>
Yes, but the controller is going to be reseted or shutdown at the moment,
even if the controller accesses a bad address and goes wrong, everything will
be ok after reset or shutdown. :)
Thanks
Jianchao
