[PATCH] nvme-core: avoid identify with CNS 06h to discovery controller

[Martin George]

On Wed, 2023-03-15 at 06:47 -0700, Christoph Hellwig wrote:
> On Sat, Mar 11, 2023 at 10:56:03PM +0530, Martin George wrote:
> > nvme_init_non_mdts_limits() currenty invokes an identify command
> > with
> > CNS 06h to both discovery and i/o controllers. But as per the NVMe-
> > oF
> > specification, this is not supported on discovery controllers:
> > 
> > "The Discovery controller shall support the Identify command with a
> > CNS value of 01h (Identify Controller data structure); all other
> > CNS
> > values are reserved."
> > 
> > So ensure this identify command with CNS 06h is sent to i/o
> > controllers
> > alone and not to discovery controllers.
> 
> This looks correct, but can we go a step further and also skip it
> for administrative controllers, i.e
> 
> > -       if (nvme_ctrl_limited_cns(ctrl))
> > +       if (nvme_ctrl_limited_cns(ctrl) ||
> > nvme_discovery_ctrl(ctrl))
> 
>         if (ctrl->subsys->subtype != NVME_NQN_NVME ||
>             nvme_ctrl_limited_cns(ctrl))
> 
> ?

Sure. Will send a new patch for the same.

-Martin