[PATCH 4/4] nvme: check that EUI/GUID/UUID are globally unique

[Keith Busch]

On Mon, Jun 06, 2022 at 08:35:39PM +0000, Alan Adamson wrote:
> 
> 
> > On Apr 20, 2022, at 12:36 AM, Christoph Hellwig <hch at lst.de> wrote:
> > 
> > On Mon, Apr 18, 2022 at 11:30:33PM +0000, Alan Adamson wrote:
> >> I ran into an issue with blktests and my qemu setup when passthru is enabled.  The passthru tests
> >> do not complete.  This was because the UUID for the passthru device is coming from the a device
> >> from the same system since the fabric was setup as a loop and nvme_global_check_duplicate_ids() fails.
> >> 
> >> This is probably not a valid real life configuration, but since blktests try to test fabrics on a single
> >> system, we have this issue.
> >> 
> >> I’ve hacked together a fix to manipulate Namespace Identifier’s to get the test to work.  Is there a
> >> why for blktests to hardcode the IDs for the passthru devices?
> > 
> > Hmm.  I suspect the best thing would be to optionally just clear the
> > IDS entirely.  Optionally as in maybe a fabrics connect argument,
> > with it defaulting to true only for loop as that is per definition
> > local.
> 
> Here are the changes to support a clear-ids nvme connect argument.  Want to float these changes prior
> to sending a formal patch out.

Shouldn't the nvme-passthrough target just change the cntlid so it looks like
two controllers in the same subsystem? That would just need to stop overriding
the subsysnqn, which is what currently happens.