1 files changed, 34 insertions, 45 deletions

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index bd0ee312dac9..142f64745fba 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -718,8 +718,6 @@ svc_exit_thread(struct svc_rqst *rqstp)
 }
 EXPORT_SYMBOL_GPL(svc_exit_thread);
 
-#ifdef CONFIG_SUNRPC_REGISTER_V4
-
 /*
  * Register an "inet" protocol family netid with the local
  * rpcbind daemon via an rpcbind v4 SET request.
@@ -734,12 +732,13 @@ static int __svc_rpcb_register4(const u32 program, const u32 version,
                                 const unsigned short protocol,
                                 const unsigned short port)
 {
-        struct sockaddr_in sin = {
+        const struct sockaddr_in sin = {
                 .sin_family             = AF_INET,
                 .sin_addr.s_addr        = htonl(INADDR_ANY),
                 .sin_port               = htons(port),
         };
-        char *netid;
+        const char *netid;
+        int error;
 
         switch (protocol) {
         case IPPROTO_UDP:
@@ -752,10 +751,20 @@ static int __svc_rpcb_register4(const u32 program, const u32 version,
                 return -ENOPROTOOPT;
         }
 
-        return rpcb_v4_register(program, version,
-                                (struct sockaddr *)&sin, netid);
+        error = rpcb_v4_register(program, version,
+                                        (const struct sockaddr *)&sin, netid);
+
+        /*
+         * User space didn't support rpcbind v4, so retry this
+         * registration request with the legacy rpcbind v2 protocol.
+         */
+        if (error == -EPROTONOSUPPORT)
+                error = rpcb_register(program, version, protocol, port);
+
+        return error;
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 /*
  * Register an "inet6" protocol family netid with the local
  * rpcbind daemon via an rpcbind v4 SET request.
@@ -770,12 +779,13 @@ static int __svc_rpcb_register6(const u32 program, const u32 version,
                                 const unsigned short protocol,
                                 const unsigned short port)
 {
-        struct sockaddr_in6 sin6 = {
+        const struct sockaddr_in6 sin6 = {
                 .sin6_family            = AF_INET6,
                 .sin6_addr              = IN6ADDR_ANY_INIT,
                 .sin6_port              = htons(port),
         };
-        char *netid;
+        const char *netid;
+        int error;
 
         switch (protocol) {
         case IPPROTO_UDP:
@@ -788,9 +798,19 @@ static int __svc_rpcb_register6(const u32 program, const u32 version,
                 return -ENOPROTOOPT;
         }
 
-        return rpcb_v4_register(program, version,
-                                (struct sockaddr *)&sin6, netid);
+        error = rpcb_v4_register(program, version,
+                                        (const struct sockaddr *)&sin6, netid);
+
+        /*
+         * User space didn't support rpcbind version 4, so we won't
+         * use a PF_INET6 listener.
+         */
+        if (error == -EPROTONOSUPPORT)
+                error = -EAFNOSUPPORT;
+
+        return error;
 }
+#endif  /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
 
 /*
  * Register a kernel RPC service via rpcbind version 4.
@@ -809,48 +829,17 @@ static int __svc_register(const u32 program, const u32 version,
         case PF_INET:
                 return __svc_rpcb_register4(program, version,
                                                 protocol, port);
+                break;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
         case PF_INET6:
-                error = __svc_rpcb_register6(program, version,
+                return__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;
+#endif  /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
         }
 
         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,
-                          const int family,
-                          const unsigned short protocol,
-                          const unsigned short port)
-{
-        if (family != PF_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