SUNRPC: Don't auto-disconnect from the local rpcbind socket

There is no need for the kernel to time out the AF_LOCAL connection to
the rpcbind socket, and doing so is problematic because when it is
time to reconnect, our process may no longer be using the same mount
namespace.

Reported-by: Nix <nix@esperi.org.uk>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org # 3.9.x

1 files changed, 8 insertions, 0 deletions

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 3df764dc330c..b0f723227157 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -238,6 +238,14 @@ static int rpcb_create_local_unix(struct net *net)
                 .program        = &rpcb_program,
                 .version        = RPCBVERS_2,
                 .authflavor     = RPC_AUTH_NULL,
+                /*
+                 * We turn off the idle timeout to prevent the kernel
+                 * from automatically disconnecting the socket.
+                 * Otherwise, we'd have to cache the mount namespace
+                 * of the caller and somehow pass that to the socket
+                 * reconnect code.
+                 */
+                .flags          = RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
         };
         struct rpc_clnt *clnt, *clnt4;
         int result = 0;