[RFC][PATCH 2/4] sunrpc: Use utsnamespaces

Serge E. Hallyn serue at us.ibm.com
Tue Jan 6 13:53:24 PST 2009


Quoting J. Bruce Fields (bfields at fieldses.org):
> On Tue, Jan 06, 2009 at 02:02:29PM -0600, Serge E. Hallyn wrote:
> > Quoting Matt Helsley (matthltc at us.ibm.com):
> > > We can often specify the UTS namespace to use when starting an RPC client.
> > > However sometimes no UTS namespace is available (specifically during system
> > > shutdown as the last NFS mount in a container is unmounted) so fall
> > > back to the initial UTS namespace.
> > 
> > So what happens if we take this patch and do nothing else?
> > 
> > The only potential problem situation will be rpc requests
> > made on behalf of a container in which the last task has
> > exited, right?  So let's say a container did an nfs mount
> > and then exits, causing an nfs umount request.
> > 
> > That umount request will now be sent with the wrong nodename.
> > Does that actually cause problems, will the server use the
> > nodename to try and determine the client sending the request?
> 
> This is just the machine name in the auth_unix credential?  The linux
> server ignores that completely (for the purpose of auth_unix
> authenication, it identifies clients only by source ip address).  I
> suspect other servers also ignore it, but I don't know.

Thanks, that's what i was hoping...

Matt, have you audited the other rpc-based services?  Do any
of them care?

-serge


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