lkml.org 
[lkml]   [2008]   [Sep]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC][PATCH] sunrpc: fix oops in rpc_create() when the mount namespace is unshared
Chuck Lever <chuck.lever@oracle.com> writes:

> If the upper layers are responsible for providing the utsname, you will need to
> fix up lockd and the NFS server's callback client too, at least.

Actually looking at the code. It looks like a proper fix may be even simpler.
Why do we have both clnt->cl_server and clnt->cl_nodename? Or is cl_server
the other side of the connection?

>>> What are we trying to achieve by reading utsname?
>>
>> It looks like it gets copied into the sunrpc messages so I assume it is
>> a part of the sunrpc spec?
>
> It appears to be used only for RPC's AUTH_SYS credentials. The nodename is used
> to identify the caller's host. See RFC 1831, Appendix A:
>
> http://rfclibrary.hosting.com/rfc/rfc1831/rfc1831-16.asp

Thanks that helps a lot.

> I'm not terribly familiar with uts namespaces, though. Can someone explain why
> we need to distinguish between these for AUTH_SYS if the caller is on a remote
> system?

Semantically processes in different uts namespaces are on different machines.

> I don't like the idea of an oops in here. Instead, (for now) it should warn and
> fail to create the client, IMO.

Which is interesting when the problem happens during NFS unmount. Although
frankly it could fail anyway.

It seems strange that we are creating a client during unmount anyway.

Eric


\
 
 \ /
  Last update: 2008-09-09 20:27    [W:0.609 / U:2.496 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site