SUNRPC: Replace svc_addr_u by sockaddr_storage

For IPv6 local address, lockd can not callback to client for
missing scope id when binding address at inet6_bind:

 324       if (addr_type & IPV6_ADDR_LINKLOCAL) {
 325               if (addr_len >= sizeof(struct sockaddr_in6) &&
 326                   addr->sin6_scope_id) {
 327                       /* Override any existing binding, if another one
 328                        * is supplied by user.
 329                        */
 330                       sk->sk_bound_dev_if = addr->sin6_scope_id;
 331               }
 332
 333               /* Binding to link-local address requires an interface */
 334               if (!sk->sk_bound_dev_if) {
 335                       err = -EINVAL;
 336                       goto out_unlock;
 337               }

Replacing svc_addr_u by sockaddr_storage, let rqstp->rq_daddr contains more info
besides address.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index a78a51e..d8d5d93 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -212,11 +212,6 @@
 	iov->iov_len += sizeof(__be32);
 }
 
-union svc_addr_u {
-    struct in_addr	addr;
-    struct in6_addr	addr6;
-};
-
 /*
  * The context of a single thread, including the request currently being
  * processed.
@@ -225,8 +220,12 @@
 	struct list_head	rq_list;	/* idle list */
 	struct list_head	rq_all;		/* all threads list */
 	struct svc_xprt *	rq_xprt;	/* transport ptr */
+
 	struct sockaddr_storage	rq_addr;	/* peer address */
 	size_t			rq_addrlen;
+	struct sockaddr_storage	rq_daddr;	/* dest addr of request
+						 *  - reply from here */
+	size_t			rq_daddrlen;
 
 	struct svc_serv *	rq_server;	/* RPC service definition */
 	struct svc_pool *	rq_pool;	/* thread pool */
@@ -255,9 +254,6 @@
 	unsigned short
 				rq_secure  : 1;	/* secure port */
 
-	union svc_addr_u	rq_daddr;	/* dest addr of request
-						 *  - reply from here */
-
 	void *			rq_argp;	/* decoded arguments */
 	void *			rq_resp;	/* xdr'd results */
 	void *			rq_auth_data;	/* flavor-specific data */
@@ -300,6 +296,21 @@
 	return (struct sockaddr *) &rqst->rq_addr;
 }
 
+static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst)
+{
+	return (struct sockaddr_in *) &rqst->rq_daddr;
+}
+
+static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst)
+{
+	return (struct sockaddr_in6 *) &rqst->rq_daddr;
+}
+
+static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst)
+{
+	return (struct sockaddr *) &rqst->rq_daddr;
+}
+
 /*
  * Check buffer bounds after decoding arguments
  */
@@ -340,7 +351,8 @@
 	struct svc_xprt		*xprt;
 	struct sockaddr_storage	addr;	/* where reply must go */
 	size_t			addrlen;
-	union svc_addr_u	daddr;	/* where reply must come from */
+	struct sockaddr_storage	daddr;	/* where reply must come from */
+	size_t			daddrlen;
 	struct cache_deferred_req handle;
 	size_t			xprt_hlen;
 	int			argslen;