1 files changed, 13 insertions, 0 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 3e65719f1ef6..f91377c14951 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1114,6 +1114,7 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
         struct svc_sock *svsk;
         struct sock     *inet;
         int             pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
+        int             val;
 
         dprintk("svc: svc_setup_socket %p\n", sock);
         if (!(svsk = kzalloc(sizeof(*svsk), GFP_KERNEL))) {
@@ -1146,6 +1147,18 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
         else
                 svc_tcp_init(svsk, serv);
 
+        /*
+         * We start one listener per sv_serv.  We want AF_INET
+         * requests to be automatically shunted to our AF_INET6
+         * listener using a mapped IPv4 address.  Make sure
+         * no-one starts an equivalent IPv4 listener, which
+         * would steal our incoming connections.
+         */
+        val = 0;
+        if (serv->sv_family == AF_INET6)
+                kernel_setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
+                                        (char *)&val, sizeof(val));
+
         dprintk("svc: svc_setup_socket created %p (inet %p)\n",
                                 svsk, svsk->sk_sk);