[PATCH] nvme-rdma: fix crash for no IO queues

[Keith Busch]

On Wed, Mar 03, 2021 at 08:41:58AM +0100, Hannes Reinecke wrote:
> On 3/3/21 4:39 AM, Chao Leng wrote:
> > 
> > 
> > On 2021/3/3 11:14, Keith Busch wrote:
> >> On Wed, Mar 03, 2021 at 10:27:01AM +0800, Chao Leng wrote:
> >>> On 2021/3/3 2:24, Keith Busch wrote:
> >>>> We can continue to administrate a controller that didn't create IO
> >>>> queues, but the controller must provide a response to all commands. If
> >>>> it doesn't, the controller will either be reset or abandoned. This
> >>>> should be the same behavior for any transport, though; there's nothing
> >>>> special about PCIe for that.
> >>> Though I don't see any useful scenarios for nvme over fabric now,
> >>> Reserved for future possibilities may be a better choice.
> >>
> >> The admin queue may be the only way for a user to retrieve useful
> >> information on the malfunctioning controller. The telemetry log isn't
> >> unique to PCIe.
> > User can also directly visit target to get these information for
> > nvme over fabrics.
> 
> Not necessarily. There is no requirement that the storage admin is
> identical to the host admin; in fact, in larger installations both roles
> are strictly separated.

There's also no requirement that nvme targets providing anything but
in-band management capabilities, so there is no justification for
relying on a vendor specific method.