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

[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.

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Cedric Le Goater <clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
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-qjLDD68F18O7TbgM5vRIOg@public.gmane.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;
 

--