NFSv4.1 test and add 4.1 trunking transport

For each location returned in FS_LOCATION query, establish a
transport to the server, send EXCHANGE_ID and test for trunking,
if successful, add the transport to the exiting client.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4proc.c

@@ -3935,6 +3935,56 @@ int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
 	return err;
 }
 
+static void test_fs_location_for_trunking(struct nfs4_fs_location *location,
+					  struct nfs_client *clp,
+					  struct nfs_server *server)
+{
+	int i;
+
+	for (i = 0; i < location->nservers; i++) {
+		struct nfs4_string *srv_loc = &location->servers[i];
+		struct sockaddr addr;
+		size_t addrlen;
+		struct xprt_create xprt_args = {
+			.ident = 0,
+			.net = clp->cl_net,
+		};
+		struct nfs4_add_xprt_data xprtdata = {
+			.clp = clp,
+		};
+		struct rpc_add_xprt_test rpcdata = {
+			.add_xprt_test = clp->cl_mvops->session_trunk,
+			.data = &xprtdata,
+		};
+		char *servername = NULL;
+
+		if (!srv_loc->len)
+			continue;
+
+		addrlen = nfs_parse_server_name(srv_loc->data, srv_loc->len,
+						&addr, sizeof(addr),
+						clp->cl_net, server->port);
+		if (!addrlen)
+			return;
+		xprt_args.dstaddr = &addr;
+		xprt_args.addrlen = addrlen;
+		servername = kmalloc(srv_loc->len + 1, GFP_KERNEL);
+		if (!servername)
+			return;
+		memcpy(servername, srv_loc->data, srv_loc->len);
+		servername[srv_loc->len] = '\0';
+		xprt_args.servername = servername;
+
+		xprtdata.cred = nfs4_get_clid_cred(clp);
+		rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
+				  rpc_clnt_setup_test_and_add_xprt,
+				  &rpcdata);
+		if (xprtdata.cred)
+			put_cred(xprtdata.cred);
+		kfree(servername);
+	}
+}
+
 static int _nfs4_discover_trunking(struct nfs_server *server,
 				   struct nfs_fh *fhandle)
 {
@@ -3944,7 +3994,7 @@ static int _nfs4_discover_trunking(struct nfs_server *server,
 	struct nfs_client *clp = server->nfs_client;
 	const struct nfs4_state_maintenance_ops *ops =
 		clp->cl_mvops->state_renewal_ops;
-	int status = -ENOMEM;
+	int status = -ENOMEM, i;
 
 	cred = ops->get_state_renewal_cred(clp);
 	if (cred == NULL) {
@@ -3962,6 +4012,10 @@ static int _nfs4_discover_trunking(struct nfs_server *server,
 					 cred);
 	if (status)
 		goto out;
+
+	for (i = 0; i < locations->nlocations; i++)
+		test_fs_location_for_trunking(&locations->locations[i], clp,
+					      server);
 out:
 	if (page)
 		__free_page(page);