[PATCH 3/3] nvmet: include all configured ports in the discovery log page

[Sagi Grimberg]

>> My issue is that its causing the unique disc-susbsys behavior diverge
>> from the standard one...
> 
> Ah. Okay.
> That is true.
> 
> But having the default setup reflected in configfs is hard, as then you 
> would need to create links from the default discovery subsystem to each 
> port (on port creation!).
> The current configfs design simply doesn't allow you to do that, so 
> attempting something like that would break compability.
> 
> Which is the big plus for this patchset; it doesn't change the user 
> interface, and nvmetcli can be used as-is.
> 
> So sure, I can have a look to expose the default discovery subsystem, 
> too. But that would require a module or configfs parameter, _and_ will 
> require changes to nvmetcli.

Before this patch, you added support for unique disc-subsys NQNs, which
behaved similarly to the standard disc-subsys. In this patch, you
made unique disc-subsys return a different discovery log-page. That is
my issue.

There are 3 approaches we can take instead:
1. ignore this patch, and make the unique disc-subsys to be attached
to multiple ports, but return only subsystems in the same port where
the host is accessing it.

2. make the standard disc-subsys return subsystems on all ports like
what you proposed for unique disc-subsys in this patch.

3. introduce an explicit setting for unique disc-subsys to return cross
port log page. i.e. make the divergence explicit.