[PATCH 2/2] nvme: use blk-mq polling for uring commands

[Sagi Grimberg]

>>> +	if (blk_rq_is_poll(req))
>>> +		WRITE_ONCE(ioucmd->cookie, req);
>>
>> Why aren't we always setting the cookie to point at the req?
> 
> As in unconditionally set the cookie even for non-polled requests? We need to
> see that the cookie is NULL to prevent polling interrupt queues when an
> io_uring polled command is dispatched to a device without polled hctx's.

Why don't we export that to an explicit flag? It would make it cleaner
I think.