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

[Sagi Grimberg]

> > > 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?

The patch from Chaitanya

See "[PATCH V4 2/2] nvme-core: use xarray for ctrl ns tracking"