Re: [Nbd] [RFC 4/4] nbd: Add support for nbd as root device

[Wouter Verhelst <w@...112...>]

On Fri, Feb 06, 2015 at 08:16:59AM +0100, Markus Pargmann wrote:
> On Thu, Feb 05, 2015 at 09:23:10AM +0100, Wouter Verhelst wrote:
> > [Cc list trimmed]
> > 
> > On Sat, Jan 31, 2015 at 01:38:21PM +0100, Markus Pargmann wrote:
> > > On Fri, Jan 30, 2015 at 06:30:14PM +0100, Wouter Verhelst wrote:
> > > > - When a connection is started by nbd-client, the kernel creates a "pid"
> > > >   file in sysfs, which contains the PID of the client and which the
> > > >   client (when called with -c, or in other cases) uses to verify whether
> > > >   a device is connected. At first glance, your patch does not do this,
> > > >   which could cause confusion.
> > > 
> > > I am actually not quite happy to expose the pid of the task that is
> > > doing the receive handling through sysfs. As it is already in the code,
> > > we can't simply remove it. But I think this should be managed by
> > > userspace if it is necessary at some point. It seems like the pid is
> > > only used for the connection status?
> > 
> > In the nbd-client code, that's true.
> > 
> > However, in case of multiple connected devices and a hung connection, knowing
> > which PID corresponds to which device is a useful debugging aid.
> 
> I see. Hopefully this is not necessary as soon as the timeout issue is
> fixed.

Possibly. On the other hand, having a debugging aid (when things are
broken) is never a bad thing, no?

I don't konw about you, but I'm not ready to guarantee that I'll never
make any mistake ;-)

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