[RFC] nvme-mpath: delete disk after last connection

[Christoph Hellwig]

On Sat, Sep 26, 2020 at 01:16:51PM +0200, Hannes Reinecke wrote:
> I'm okay with that in general, but then again we might run into situations 
> where an 'all paths down' scenario is actually expected (think of a 
> temporary network outage on nvme-tcp).
> So I guess we need to introduce an additional setting (queue_if_no_path?) 
> to be specified during the initial connection.

The original design was pretty much intentional as and all paths down
even usually is temporary.  So any change in behavior should be based
on an optional instead of a change in default.  And I think the right
way to do implement this would be a timer when to take the gendisk
down, with the default remaining infinitity.