[PATCH v15 7/9] nvmet-passthru: Add passthru code to process commands

[Logan Gunthorpe]

On 2020-07-20 4:35 p.m., Sagi Grimberg wrote:
> 
>> Thanks for the review Christoph. I think I should be able to make all
>> the requested changes in the next week or two.
>>
>> On 2020-07-20 1:35 p.m., Sagi Grimberg wrote:
>>>
>>>> I'm still not so happy about having to look up the namespace and still
>>>> wonder if we should generalize the connect_q to a passthrough_q.  But
>>>> I guess we can do that later and then reduce some of the exports here..
>>>
>>> That is a neat idea! should be easy to do (and we can then lose the host
>>> xarray stuff). I don't mind having it on a later patch, but it should be
>>> easy enough to do even before...
>>>
>>
>> I sort of follow this. I can try to work something up but it will
>> probably take me a few iterations to get it to where you want it. So,
>> roughly, we'd create a passthrough_q in core with the controller's IO
>> tagset and then cleanup the fabrics hosts to use that instead of each
>> independently creating their connect_q?
>>
>> Though, I don't understand how this relates to the host xarray stuff
>> that Sagi mentioned...
> 
> passthru commands are in essence REQ_OP_DRV_IN/REQ_OP_DRV_OUT, which
> means that the driver shouldn't need the ns at all. So if you have a
> dedicated request queue (mapped to the I/O tagset), you don't need the
> ns->queue and we can lose the ns lookup altogether.

Thanks, that helps clarify things a bit, but which xarray were you
talking about?

Logan