Messages in this thread | | | From | Chuck Lever <> | Subject | Re: [RFC][PATCH 2/4] sunrpc: Use utsnamespaces | Date | Tue, 6 Jan 2009 17:29:05 -0500 |
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On Jan 6, 2009, at Jan 6, 2009, 3:02 PM, Serge E. Hallyn wrote: > Quoting Matt Helsley (matthltc@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?
I thought the point of this was to prevent incorrect container nodenames from leaking onto the network.
> 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? > > thanks, > -serge > >> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> >> Cc: Cedric Le Goater <clg@fr.ibm.com> >> Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org> >> Cc: linux-nfs@vger.kernel.org >> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> >> Cc: Chuck Lever <chuck.lever@oracle.com> >> Cc: Eric W. Biederman <ebiederm@xmission.com> >> Cc: Linux Containers <containers@lists.osdl.org> >> >> --- >> net/sunrpc/clnt.c | 7 +++++-- >> 1 file changed, 5 insertions(+), 2 deletions(-) >> >> Index: linux-2.6.28/net/sunrpc/clnt.c >> =================================================================== >> --- linux-2.6.28.orig/net/sunrpc/clnt.c >> +++ linux-2.6.28/net/sunrpc/clnt.c >> @@ -128,6 +128,7 @@ static struct rpc_clnt * rpc_new_client( >> struct rpc_version *version; >> struct rpc_clnt *clnt = NULL; >> struct rpc_auth *auth; >> + struct new_utsname *uts_ns = init_utsname(); >> int err; >> size_t len; >> >> @@ -213,10 +214,12 @@ static struct rpc_clnt * rpc_new_client( >> } >> >> /* save the nodename */ >> - clnt->cl_nodelen = strlen(init_utsname()->nodename); >> + if (current->nsproxy != NULL) >> + uts_ns = utsname(); >> + clnt->cl_nodelen = strlen(uts_ns->nodename); >> if (clnt->cl_nodelen > UNX_MAXNODENAME) >> clnt->cl_nodelen = UNX_MAXNODENAME; >> - memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt- >> >cl_nodelen); >> + memcpy(clnt->cl_nodename, uts_ns->nodename, clnt->cl_nodelen); >> rpc_register_client(clnt); >> return clnt; >> >> >> -- >> _______________________________________________ >> Containers mailing list >> Containers@lists.linux-foundation.org >> https://lists.linux-foundation.org/mailman/listinfo/containers
-- Chuck Lever chuck[dot]lever[at]oracle[dot]com
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