5 files changed, 305 insertions, 85 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 76739e928d0d..da0789fa1b88 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -174,7 +174,7 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, stru
         clnt->cl_procinfo = version->procs;
         clnt->cl_maxproc  = version->nrprocs;
         clnt->cl_protname = program->name;
-        clnt->cl_prog     = program->number;
+        clnt->cl_prog     = args->prognumber ? : program->number;
         clnt->cl_vers     = version->number;
         clnt->cl_stats    = program->stats;
         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 24db2b4d12d3..34abc91058d8 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -20,6 +20,7 @@
 #include <linux/in6.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#include <net/ipv6.h>
 
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/sched.h>
@@ -176,13 +177,12 @@ static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 }
 
 static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
-                              u32 version, struct rpc_message *msg,
-                              int *result)
+                              u32 version, struct rpc_message *msg)
 {
         struct rpc_clnt *rpcb_clnt;
-        int error = 0;
+        int result, error = 0;
 
-        *result = 0;
+        msg->rpc_resp = &result;
 
         rpcb_clnt = rpcb_create_local(addr, addrlen, version);
         if (!IS_ERR(rpcb_clnt)) {
@@ -191,12 +191,15 @@ static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
         } else
                 error = PTR_ERR(rpcb_clnt);
 
-        if (error < 0)
+        if (error < 0) {
                 printk(KERN_WARNING "RPC: failed to contact local rpcbind "
                                 "server (errno %d).\n", -error);
-        dprintk("RPC:       registration status %d/%d\n", error, *result);
+                return error;
+        }
 
-        return error;
+        if (!result)
+                return -EACCES;
+        return 0;
 }
 
 /**
@@ -205,7 +208,11 @@ static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
  * @vers: RPC version number to bind
  * @prot: transport protocol to register
  * @port: port value to register
- * @okay: OUT: result code
+ *
+ * Returns zero if the registration request was dispatched successfully
+ * and the rpcbind daemon returned success.  Otherwise, returns an errno
+ * value that reflects the nature of the error (request could not be
+ * dispatched, timed out, or rpcbind returned an error).
  *
  * RPC services invoke this function to advertise their contact
  * information via the system's rpcbind daemon.  RPC services
@@ -217,15 +224,6 @@ static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
  * all registered transports for [program, version] from the local
  * rpcbind database.
  *
- * Returns zero if the registration request was dispatched
- * successfully and a reply was received.  The rpcbind daemon's
- * boolean result code is stored in *okay.
- *
- * Returns an errno value and sets *result to zero if there was
- * some problem that prevented the rpcbind request from being
- * dispatched, or if the rpcbind daemon did not respond within
- * the timeout.
- *
  * This function uses rpcbind protocol version 2 to contact the
  * local rpcbind daemon.
  *
@@ -236,7 +234,7 @@ static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
  * addresses).
  */
-int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
+int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 {
         struct rpcbind_args map = {
                 .r_prog         = prog,
@@ -246,7 +244,6 @@ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
         };
         struct rpc_message msg = {
                 .rpc_argp       = &map,
-                .rpc_resp       = okay,
         };
 
         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
@@ -259,7 +256,7 @@ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
 
         return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
                                         sizeof(rpcb_inaddr_loopback),
-                                        RPCBVERS_2, &msg, okay);
+                                        RPCBVERS_2, &msg);
 }
 
 /*
@@ -290,7 +287,7 @@ static int rpcb_register_netid4(struct sockaddr_in *address_to_register,
 
         return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
                                         sizeof(rpcb_inaddr_loopback),
-                                        RPCBVERS_4, msg, msg->rpc_resp);
+                                        RPCBVERS_4, msg);
 }
 
 /*
@@ -304,10 +301,13 @@ static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
         char buf[64];
 
         /* Construct AF_INET6 universal address */
-        snprintf(buf, sizeof(buf),
-                        NIP6_FMT".%u.%u",
-                        NIP6(address_to_register->sin6_addr),
-                        port >> 8, port & 0xff);
+        if (ipv6_addr_any(&address_to_register->sin6_addr))
+                snprintf(buf, sizeof(buf), "::.%u.%u",
+                                port >> 8, port & 0xff);
+        else
+                snprintf(buf, sizeof(buf), NIP6_FMT".%u.%u",
+                                NIP6(address_to_register->sin6_addr),
+                                port >> 8, port & 0xff);
         map->r_addr = buf;
 
         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
@@ -321,7 +321,7 @@ static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
 
         return rpcb_register_call((struct sockaddr *)&rpcb_in6addr_loopback,
                                         sizeof(rpcb_in6addr_loopback),
-                                        RPCBVERS_4, msg, msg->rpc_resp);
+                                        RPCBVERS_4, msg);
 }
 
 /**
@@ -330,7 +330,11 @@ static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
  * @version: RPC version number of service to (un)register
  * @address: address family, IP address, and port to (un)register
  * @netid: netid of transport protocol to (un)register
- * @result: result code from rpcbind RPC call
+ *
+ * Returns zero if the registration request was dispatched successfully
+ * and the rpcbind daemon returned success.  Otherwise, returns an errno
+ * value that reflects the nature of the error (request could not be
+ * dispatched, timed out, or rpcbind returned an error).
  *
  * RPC services invoke this function to advertise their contact
  * information via the system's rpcbind daemon.  RPC services
@@ -342,15 +346,6 @@ static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
  * to zero.  Callers pass a netid of "" to unregister all
  * transport netids associated with [program, version, address].
  *
- * Returns zero if the registration request was dispatched
- * successfully and a reply was received.  The rpcbind daemon's
- * result code is stored in *result.
- *
- * Returns an errno value and sets *result to zero if there was
- * some problem that prevented the rpcbind request from being
- * dispatched, or if the rpcbind daemon did not respond within
- * the timeout.
- *
  * This function uses rpcbind protocol version 4 to contact the
  * local rpcbind daemon.  The local rpcbind daemon must support
  * version 4 of the rpcbind protocol in order for these functions
@@ -372,8 +367,7 @@ static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
  * advertises the service on all IPv4 and IPv6 addresses.
  */
 int rpcb_v4_register(const u32 program, const u32 version,
-                     const struct sockaddr *address, const char *netid,
-                     int *result)
+                     const struct sockaddr *address, const char *netid)
 {
         struct rpcbind_args map = {
                 .r_prog         = program,
@@ -383,11 +377,8 @@ int rpcb_v4_register(const u32 program, const u32 version,
         };
         struct rpc_message msg = {
                 .rpc_argp       = &map,
-                .rpc_resp       = result,
         };
 
-        *result = 0;
-
         switch (address->sa_family) {
         case AF_INET:
                 return rpcb_register_netid4((struct sockaddr_in *)address,
@@ -633,7 +624,7 @@ static void rpcb_getport_done(struct rpc_task *child, void *data)
 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
                                struct rpcbind_args *rpcb)
 {
-        dprintk("RPC:       rpcb_encode_mapping(%u, %u, %d, %u)\n",
+        dprintk("RPC:       encoding rpcb request (%u, %u, %d, %u)\n",
                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
         *p++ = htonl(rpcb->r_prog);
         *p++ = htonl(rpcb->r_vers);
@@ -648,7 +639,7 @@ static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
                                unsigned short *portp)
 {
         *portp = (unsigned short) ntohl(*p++);
-        dprintk("RPC:       rpcb_decode_getport result %u\n",
+        dprintk("RPC:       rpcb getport result: %u\n",
                         *portp);
         return 0;
 }
@@ -657,7 +648,7 @@ static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
                            unsigned int *boolp)
 {
         *boolp = (unsigned int) ntohl(*p++);
-        dprintk("RPC:       rpcb_decode_set: call %s\n",
+        dprintk("RPC:       rpcb set/unset call %s\n",
                         (*boolp ? "succeeded" : "failed"));
         return 0;
 }
@@ -665,7 +656,7 @@ static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
                                struct rpcbind_args *rpcb)
 {
-        dprintk("RPC:       rpcb_encode_getaddr(%u, %u, %s)\n",
+        dprintk("RPC:       encoding rpcb request (%u, %u, %s)\n",
                         rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
         *p++ = htonl(rpcb->r_prog);
         *p++ = htonl(rpcb->r_vers);
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 5a32cb7c4bb4..54c98d876847 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -28,6 +28,8 @@
 
 #define RPCDBG_FACILITY RPCDBG_SVCDSP
 
+static void svc_unregister(const struct svc_serv *serv);
+
 #define svc_serv_is_pooled(serv)    ((serv)->sv_function)
 
 /*
@@ -357,7 +359,7 @@ svc_pool_for_cpu(struct svc_serv *serv, int cpu)
  */
 static struct svc_serv *
 __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
-           void (*shutdown)(struct svc_serv *serv))
+           sa_family_t family, void (*shutdown)(struct svc_serv *serv))
 {
         struct svc_serv *serv;
         unsigned int vers;
@@ -366,6 +368,7 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 
         if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
                 return NULL;
+        serv->sv_family    = family;
         serv->sv_name      = prog->pg_name;
         serv->sv_program   = prog;
         serv->sv_nrthreads = 1;
@@ -416,30 +419,29 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
                 spin_lock_init(&pool->sp_lock);
         }
 
-
         /* Remove any stale portmap registrations */
-        svc_register(serv, 0, 0);
+        svc_unregister(serv);
 
         return serv;
 }
 
 struct svc_serv *
 svc_create(struct svc_program *prog, unsigned int bufsize,
-                void (*shutdown)(struct svc_serv *serv))
+                sa_family_t family, void (*shutdown)(struct svc_serv *serv))
 {
-        return __svc_create(prog, bufsize, /*npools*/1, shutdown);
+        return __svc_create(prog, bufsize, /*npools*/1, family, shutdown);
 }
 EXPORT_SYMBOL(svc_create);
 
 struct svc_serv *
 svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
-                void (*shutdown)(struct svc_serv *serv),
+                  sa_family_t family, void (*shutdown)(struct svc_serv *serv),
                   svc_thread_fn func, struct module *mod)
 {
         struct svc_serv *serv;
         unsigned int npools = svc_pool_map_get();
 
-        serv = __svc_create(prog, bufsize, npools, shutdown);
+        serv = __svc_create(prog, bufsize, npools, family, shutdown);
 
         if (serv != NULL) {
                 serv->sv_function = func;
@@ -486,8 +488,7 @@ svc_destroy(struct svc_serv *serv)
         if (svc_serv_is_pooled(serv))
                 svc_pool_map_put();
 
-        /* Unregister service with the portmapper */
-        svc_register(serv, 0, 0);
+        svc_unregister(serv);
         kfree(serv->sv_pools);
         kfree(serv);
 }
@@ -718,55 +719,245 @@ svc_exit_thread(struct svc_rqst *rqstp)
 }
 EXPORT_SYMBOL(svc_exit_thread);
 
+#ifdef CONFIG_SUNRPC_REGISTER_V4
+
 /*
- * Register an RPC service with the local portmapper.
- * To unregister a service, call this routine with
- * proto and port == 0.
+ * Register an "inet" protocol family netid with the local
+ * rpcbind daemon via an rpcbind v4 SET request.
+ *
+ * No netconfig infrastructure is available in the kernel, so
+ * we map IP_ protocol numbers to netids by hand.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
  */
-int
-svc_register(struct svc_serv *serv, int proto, unsigned short port)
+static int __svc_rpcb_register4(const u32 program, const u32 version,
+                                const unsigned short protocol,
+                                const unsigned short port)
+{
+        struct sockaddr_in sin = {
+                .sin_family             = AF_INET,
+                .sin_addr.s_addr        = htonl(INADDR_ANY),
+                .sin_port               = htons(port),
+        };
+        char *netid;
+
+        switch (protocol) {
+        case IPPROTO_UDP:
+                netid = RPCBIND_NETID_UDP;
+                break;
+        case IPPROTO_TCP:
+                netid = RPCBIND_NETID_TCP;
+                break;
+        default:
+                return -EPROTONOSUPPORT;
+        }
+
+        return rpcb_v4_register(program, version,
+                                (struct sockaddr *)&sin, netid);
+}
+
+/*
+ * Register an "inet6" protocol family netid with the local
+ * rpcbind daemon via an rpcbind v4 SET request.
+ *
+ * No netconfig infrastructure is available in the kernel, so
+ * we map IP_ protocol numbers to netids by hand.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_rpcb_register6(const u32 program, const u32 version,
+                                const unsigned short protocol,
+                                const unsigned short port)
+{
+        struct sockaddr_in6 sin6 = {
+                .sin6_family            = AF_INET6,
+                .sin6_addr              = IN6ADDR_ANY_INIT,
+                .sin6_port              = htons(port),
+        };
+        char *netid;
+
+        switch (protocol) {
+        case IPPROTO_UDP:
+                netid = RPCBIND_NETID_UDP6;
+                break;
+        case IPPROTO_TCP:
+                netid = RPCBIND_NETID_TCP6;
+                break;
+        default:
+                return -EPROTONOSUPPORT;
+        }
+
+        return rpcb_v4_register(program, version,
+                                (struct sockaddr *)&sin6, netid);
+}
+
+/*
+ * Register a kernel RPC service via rpcbind version 4.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_register(const u32 program, const u32 version,
+                          const sa_family_t family,
+                          const unsigned short protocol,
+                          const unsigned short port)
+{
+        int error;
+
+        switch (family) {
+        case AF_INET:
+                return __svc_rpcb_register4(program, version,
+                                                protocol, port);
+        case AF_INET6:
+                error = __svc_rpcb_register6(program, version,
+                                                protocol, port);
+                if (error < 0)
+                        return error;
+
+                /*
+                 * Work around bug in some versions of Linux rpcbind
+                 * which don't allow registration of both inet and
+                 * inet6 netids.
+                 *
+                 * Error return ignored for now.
+                 */
+                __svc_rpcb_register4(program, version,
+                                                protocol, port);
+                return 0;
+        }
+
+        return -EAFNOSUPPORT;
+}
+
+#else   /* CONFIG_SUNRPC_REGISTER_V4 */
+
+/*
+ * Register a kernel RPC service via rpcbind version 2.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_register(const u32 program, const u32 version,
+                          sa_family_t family,
+                          const unsigned short protocol,
+                          const unsigned short port)
+{
+        if (family != AF_INET)
+                return -EAFNOSUPPORT;
+
+        return rpcb_register(program, version, protocol, port);
+}
+
+#endif /* CONFIG_SUNRPC_REGISTER_V4 */
+
+/**
+ * svc_register - register an RPC service with the local portmapper
+ * @serv: svc_serv struct for the service to register
+ * @proto: transport protocol number to advertise
+ * @port: port to advertise
+ *
+ * Service is registered for any address in serv's address family
+ */
+int svc_register(const struct svc_serv *serv, const unsigned short proto,
+                 const unsigned short port)
 {
         struct svc_program      *progp;
-        unsigned long           flags;
         unsigned int            i;
-        int                     error = 0, dummy;
+        int                     error = 0;
 
-        if (!port)
-                clear_thread_flag(TIF_SIGPENDING);
+        BUG_ON(proto == 0 && port == 0);
 
         for (progp = serv->sv_program; progp; progp = progp->pg_next) {
                 for (i = 0; i < progp->pg_nvers; i++) {
                         if (progp->pg_vers[i] == NULL)
                                 continue;
 
-                        dprintk("svc: svc_register(%s, %s, %d, %d)%s\n",
+                        dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n",
                                         progp->pg_name,
+                                        i,
                                         proto == IPPROTO_UDP?  "udp" : "tcp",
                                         port,
-                                        i,
+                                        serv->sv_family,
                                         progp->pg_vers[i]->vs_hidden?
                                                 " (but not telling portmap)" : "");
 
                         if (progp->pg_vers[i]->vs_hidden)
                                 continue;
 
-                        error = rpcb_register(progp->pg_prog, i, proto, port, &dummy);
+                        error = __svc_register(progp->pg_prog, i,
+                                                serv->sv_family, proto, port);
                         if (error < 0)
                                 break;
-                        if (port && !dummy) {
-                                error = -EACCES;
-                                break;
-                        }
                 }
         }
 
-        if (!port) {
-                spin_lock_irqsave(&current->sighand->siglock, flags);
-                recalc_sigpending();
-                spin_unlock_irqrestore(&current->sighand->siglock, flags);
+        return error;
+}
+
+#ifdef CONFIG_SUNRPC_REGISTER_V4
+
+static void __svc_unregister(const u32 program, const u32 version,
+                             const char *progname)
+{
+        struct sockaddr_in6 sin6 = {
+                .sin6_family            = AF_INET6,
+                .sin6_addr              = IN6ADDR_ANY_INIT,
+                .sin6_port              = 0,
+        };
+        int error;
+
+        error = rpcb_v4_register(program, version,
+                                (struct sockaddr *)&sin6, "");
+        dprintk("svc: %s(%sv%u), error %d\n",
+                        __func__, progname, version, error);
+}
+
+#else   /* CONFIG_SUNRPC_REGISTER_V4 */
+
+static void __svc_unregister(const u32 program, const u32 version,
+                             const char *progname)
+{
+        int error;
+
+        error = rpcb_register(program, version, 0, 0);
+        dprintk("svc: %s(%sv%u), error %d\n",
+                        __func__, progname, version, error);
+}
+
+#endif  /* CONFIG_SUNRPC_REGISTER_V4 */
+
+/*
+ * All netids, bind addresses and ports registered for [program, version]
+ * are removed from the local rpcbind database (if the service is not
+ * hidden) to make way for a new instance of the service.
+ *
+ * The result of unregistration is reported via dprintk for those who want
+ * verification of the result, but is otherwise not important.
+ */
+static void svc_unregister(const struct svc_serv *serv)
+{
+        struct svc_program *progp;
+        unsigned long flags;
+        unsigned int i;
+
+        clear_thread_flag(TIF_SIGPENDING);
+
+        for (progp = serv->sv_program; progp; progp = progp->pg_next) {
+                for (i = 0; i < progp->pg_nvers; i++) {
+                        if (progp->pg_vers[i] == NULL)
+                                continue;
+                        if (progp->pg_vers[i]->vs_hidden)
+                                continue;
+
+                        __svc_unregister(progp->pg_prog, i, progp->pg_name);
+                }
         }
 
-        return error;
+        spin_lock_irqsave(&current->sighand->siglock, flags);
+        recalc_sigpending();
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 }
 
 /*
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index e46c825f4954..bf5b5cdafebf 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -159,15 +159,44 @@ void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
 }
 EXPORT_SYMBOL_GPL(svc_xprt_init);
 
-int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port,
-                    int flags)
+static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
+                                         struct svc_serv *serv,
+                                         unsigned short port, int flags)
 {
-        struct svc_xprt_class *xcl;
         struct sockaddr_in sin = {
                 .sin_family             = AF_INET,
                 .sin_addr.s_addr        = htonl(INADDR_ANY),
                 .sin_port               = htons(port),
         };
+        struct sockaddr_in6 sin6 = {
+                .sin6_family            = AF_INET6,
+                .sin6_addr              = IN6ADDR_ANY_INIT,
+                .sin6_port              = htons(port),
+        };
+        struct sockaddr *sap;
+        size_t len;
+
+        switch (serv->sv_family) {
+        case AF_INET:
+                sap = (struct sockaddr *)&sin;
+                len = sizeof(sin);
+                break;
+        case AF_INET6:
+                sap = (struct sockaddr *)&sin6;
+                len = sizeof(sin6);
+                break;
+        default:
+                return ERR_PTR(-EAFNOSUPPORT);
+        }
+
+        return xcl->xcl_ops->xpo_create(serv, sap, len, flags);
+}
+
+int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port,
+                    int flags)
+{
+        struct svc_xprt_class *xcl;
+
         dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
         spin_lock(&svc_xprt_class_lock);
         list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
@@ -180,9 +209,7 @@ int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port,
                         goto err;
 
                 spin_unlock(&svc_xprt_class_lock);
-                newxprt = xcl->xcl_ops->
-                        xpo_create(serv, (struct sockaddr *)&sin, sizeof(sin),
-                                   flags);
+                newxprt = __svc_xpo_create(xcl, serv, port, flags);
                 if (IS_ERR(newxprt)) {
                         module_put(xcl->xcl_owner);
                         return PTR_ERR(newxprt);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 3e65719f1ef6..95293f549e9c 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);
 
@@ -1154,8 +1167,7 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
 
 int svc_addsock(struct svc_serv *serv,
                 int fd,
-                char *name_return,
-                int *proto)
+                char *name_return)
 {
         int err = 0;
         struct socket *so = sockfd_lookup(fd, &err);
@@ -1190,7 +1202,6 @@ int svc_addsock(struct svc_serv *serv,
                 sockfd_put(so);
                 return err;
         }
-        if (proto) *proto = so->sk->sk_protocol;
         return one_sock_name(name_return, svsk);
 }
 EXPORT_SYMBOL_GPL(svc_addsock);