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

[Christoph Hellwig]

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.