SUNRPC: use sockaddr + size when creating remote transport endpoints

Prepare for more generic transport endpoint handling needed by transports
that might use different forms of addressing, such as IPv6.

Introduce a single function call to replace the two-call
xprt_create_proto/rpc_create_client API.  Define a new rpc_create_args
structure that allows callers to pass in remote endpoint addresses of
varying length.

Test-plan:
Compile kernel with CONFIG_NFS enabled.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index a26d695..7817ba8 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -97,6 +97,28 @@
 struct rpc_clnt *rpc_new_client(struct rpc_xprt *xprt, char *servname,
 				struct rpc_program *info,
 				u32 version, rpc_authflavor_t authflavor);
+
+struct rpc_create_args {
+	int			protocol;
+	struct sockaddr		*address;
+	size_t			addrsize;
+	struct rpc_timeout	*timeout;
+	char			*servername;
+	struct rpc_program	*program;
+	u32			version;
+	rpc_authflavor_t	authflavor;
+	unsigned long		flags;
+};
+
+/* Values for "flags" field */
+#define RPC_CLNT_CREATE_HARDRTRY	(1UL << 0)
+#define RPC_CLNT_CREATE_INTR		(1UL << 1)
+#define RPC_CLNT_CREATE_AUTOBIND	(1UL << 2)
+#define RPC_CLNT_CREATE_ONESHOT		(1UL << 3)
+#define RPC_CLNT_CREATE_NONPRIVPORT	(1UL << 4)
+#define RPC_CLNT_CREATE_NOPING		(1UL << 5)
+
+struct rpc_clnt *rpc_create(struct rpc_create_args *args);
 struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,
 				struct rpc_program *, int);
 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *);