SUNRPC: Create a helper to tell whether a transport is bound

Hide the contents and format of xprt->addr by eliminating direct uses
of the xprt->addr.sin_port field.  This change is required to support
alternate RPC host address formats (eg IPv6).

Test-plan:
Destructive testing (unplugging the network temporarily).  Repeated runs of
Connectathon locking suite with UDP and TCP.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/xprt.h

@@ -269,6 +269,7 @@ int			xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to);
 #define XPRT_CONNECTED		(1)
 #define XPRT_CONNECTING		(2)
 #define XPRT_CLOSE_WAIT		(3)
+#define XPRT_BOUND		(4)
 
 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 {
@@ -312,6 +313,21 @@ static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 	return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 }
 
+static inline void xprt_set_bound(struct rpc_xprt *xprt)
+{
+	test_and_set_bit(XPRT_BOUND, &xprt->state);
+}
+
+static inline int xprt_bound(struct rpc_xprt *xprt)
+{
+	return test_bit(XPRT_BOUND, &xprt->state);
+}
+
+static inline void xprt_clear_bound(struct rpc_xprt *xprt)
+{
+	clear_bit(XPRT_BOUND, &xprt->state);
+}
+
 #endif /* __KERNEL__*/
 
 #endif /* _LINUX_SUNRPC_XPRT_H */

net/sunrpc/clnt.c

@@ -148,15 +148,14 @@ rpc_new_client(struct rpc_xprt *xprt, char *servname,
 	clnt->cl_maxproc  = version->nrprocs;
 	clnt->cl_protname = program->name;
 	clnt->cl_pmap	  = &clnt->cl_pmap_default;
-	clnt->cl_port     = xprt->addr.sin_port;
 	clnt->cl_prog     = program->number;
 	clnt->cl_vers     = version->number;
 	clnt->cl_prot     = xprt->prot;
 	clnt->cl_stats    = program->stats;
 	clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 	rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
 
-	if (!clnt->cl_port)
+	if (!xprt_bound(clnt->cl_xprt))
 		clnt->cl_autobind = 1;
 
 	clnt->cl_rtt = &clnt->cl_rtt_default;
@@ -570,7 +569,7 @@ EXPORT_SYMBOL(rpc_max_payload);
 void rpc_force_rebind(struct rpc_clnt *clnt)
 {
 	if (clnt->cl_autobind)
-		clnt->cl_port = 0;
+		xprt_clear_bound(clnt->cl_xprt);
 }
 EXPORT_SYMBOL(rpc_force_rebind);
 
@@ -782,14 +781,15 @@ static void
 call_bind(struct rpc_task *task)
 {
 	struct rpc_clnt	*clnt = task->tk_client;
+	struct rpc_xprt *xprt = task->tk_xprt;
 
 	dprintk("RPC: %4d call_bind (status %d)\n",
 				task->tk_pid, task->tk_status);
 
 	task->tk_action = call_connect;
-	if (!clnt->cl_port) {
+	if (!xprt_bound(xprt)) {
 		task->tk_action = call_bind_status;
-		task->tk_timeout = task->tk_xprt->bind_timeout;
+		task->tk_timeout = xprt->bind_timeout;
 		rpc_getport(task, clnt);
 	}
 }

net/sunrpc/pmap_clnt.c

@@ -142,15 +142,17 @@ pmap_getport_done(struct rpc_task *task)
 	dprintk("RPC: %4d pmap_getport_done(status %d, port %d)\n",
 			task->tk_pid, task->tk_status, clnt->cl_port);
 
-	xprt->ops->set_port(xprt, 0);
 	if (task->tk_status < 0) {
 		/* Make the calling task exit with an error */
+		xprt->ops->set_port(xprt, 0);
 		task->tk_action = rpc_exit_task;
 	} else if (clnt->cl_port == 0) {
 		/* Program not registered */
+		xprt->ops->set_port(xprt, 0);
 		rpc_exit(task, -EACCES);
 	} else {
 		xprt->ops->set_port(xprt, clnt->cl_port);
+		xprt_set_bound(xprt);
 		clnt->cl_port = htons(clnt->cl_port);
 	}
 	spin_lock(&pmap_lock);
@@ -218,6 +220,7 @@ pmap_create(char *hostname, struct sockaddr_in *srvaddr, int proto, int privileg
 	if (IS_ERR(xprt))
 		return (struct rpc_clnt *)xprt;
 	xprt->ops->set_port(xprt, RPC_PMAP_PORT);
+	xprt_set_bound(xprt);
 	if (!privileged)
 		xprt->resvport = 0;
 

net/sunrpc/xprt.c

@@ -534,7 +534,7 @@ void xprt_connect(struct rpc_task *task)
 	dprintk("RPC: %4d xprt_connect xprt %p %s connected\n", task->tk_pid,
 			xprt, (xprt_connected(xprt) ? "is" : "is not"));
 
-	if (!xprt->addr.sin_port) {
+	if (!xprt_bound(xprt)) {
 		task->tk_status = -EIO;
 		return;
 	}

net/sunrpc/xprtsock.c

@@ -1016,7 +1016,7 @@ static void xs_udp_connect_worker(void *args)
 	struct socket *sock = xprt->sock;
 	int err, status = -EIO;
 
-	if (xprt->shutdown || xprt->addr.sin_port == 0)
+	if (xprt->shutdown || !xprt_bound(xprt))
 		goto out;
 
 	dprintk("RPC:      xs_udp_connect_worker for xprt %p\n", xprt);
@@ -1099,7 +1099,7 @@ static void xs_tcp_connect_worker(void *args)
 	struct socket *sock = xprt->sock;
 	int err, status = -EIO;
 
-	if (xprt->shutdown || xprt->addr.sin_port == 0)
+	if (xprt->shutdown || !xprt_bound(xprt))
 		goto out;
 
 	dprintk("RPC:      xs_tcp_connect_worker for xprt %p\n", xprt);
@@ -1307,8 +1307,11 @@ int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
 	if (xprt->slot == NULL)
 		return -ENOMEM;
 
-	xprt->prot = IPPROTO_UDP;
+	if (ntohs(xprt->addr.sin_port) != 0)
+		xprt_set_bound(xprt);
 	xprt->port = xs_get_random_port();
+
+	xprt->prot = IPPROTO_UDP;
 	xprt->tsh_size = 0;
 	xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
 	/* XXX: header size can vary due to auth type, IPv6, etc. */
@@ -1348,8 +1351,11 @@ int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
 	if (xprt->slot == NULL)
 		return -ENOMEM;
 
-	xprt->prot = IPPROTO_TCP;
+	if (ntohs(xprt->addr.sin_port) != 0)
+		xprt_set_bound(xprt);
 	xprt->port = xs_get_random_port();
+
+	xprt->prot = IPPROTO_TCP;
 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
 	xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;