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

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

[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.

-- 
It is easy to love a country that is famous for chocolate and beer

  -- Barack Obama, speaking in Brussels, Belgium, 2014-03-26