[PATCH] nvme: don't reject probe due to duplicate IDs for single-ported PCIe devices

[Christoph Hellwig]

On Tue, Jan 20, 2026 at 05:54:25PM +0800, xiaoke at sangfor.com.cn wrote:
>
> I’d like to discuss whether we should revisit the duplicate-ID check
> for NVMe-oF transports, especially in HA dual-active setups.
>
> In such HA configurations, a single LUN is exposed via multiple subsystems
> (one per storage controller) to provide redundancy. Because it represents
> the same namespace, it usually reports the same UUID/NGUID/EUI64 on all 
> paths.

Not in any configuration confirming to the NVMe spec (discounting the
completely broken dispersed namespace feature).

So no, this is exactly what both the spec, and the code try to prevent.

> > +		if ((ns->ctrl->ops->flags & NVME_F_FABRICS) || /* !PCIe */
> > +		    ((ns->ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) &&
> > +		     info->is_shared)) {
>
> Concretely, with two subsystems exposing the same LUN in a dual-active
> HA configuration:

There are no logical units or logical unit numbers in NVMe.