dlm: do synchronized socket connect call

To avoid -EINPROGRESS cases on connect that just ends in a retry we just
call connect in a synchronized way to wait until its done. Since commit
dbb751f ("fs: dlm: parallelize lowcomms socket handling") we have a
non ordered workqueue running for serving the DLM sockets that allows us
to call send/recv for each DLM socket connection in parallel. Before
each worker needed to wait until the previous worker was done and
probably the reason why connect() was called in an asynchronous way to
not block other workers. This is however not necessary anymore as other
socket handling workers don't need to wait.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

Author: Alexander Aring

fs/dlm/lowcomms.c

@@ -161,8 +161,6 @@ struct dlm_proto_ops {
 	const char *name;
 	int proto;
 
-	int (*connect)(struct connection *con, struct socket *sock,
-		       struct sockaddr *addr, int addr_len);
 	void (*sockopts)(struct socket *sock);
 	int (*bind)(struct socket *sock);
 	int (*listen_validate)(void);
@@ -1599,8 +1597,7 @@ static int dlm_connect(struct connection *con)
 
 	log_print_ratelimited("connecting to %d", con->nodeid);
 	make_sockaddr(&addr, dlm_config.ci_tcp_port, &addr_len);
-	result = dlm_proto_ops->connect(con, sock, (struct sockaddr *)&addr,
-					addr_len);
+	result = kernel_connect(sock, (struct sockaddr *)&addr, addr_len, 0);
 	switch (result) {
 	case -EINPROGRESS:
 		/* not an error */
@@ -1634,13 +1631,6 @@ static void process_send_sockets(struct work_struct *work)
 			switch (ret) {
 			case 0:
 				break;
-			case -EINPROGRESS:
-				/* avoid spamming resched on connection
-				 * we might can switch to a state_change
-				 * event based mechanism if established
-				 */
-				msleep(100);
-				break;
 			default:
 				/* CF_SEND_PENDING not cleared */
 				up_write(&con->sock_lock);
@@ -1831,12 +1821,6 @@ static int dlm_tcp_bind(struct socket *sock)
 	return 0;
 }
 
-static int dlm_tcp_connect(struct connection *con, struct socket *sock,
-			   struct sockaddr *addr, int addr_len)
-{
-	return kernel_connect(sock, addr, addr_len, O_NONBLOCK);
-}
-
 static int dlm_tcp_listen_validate(void)
 {
 	/* We don't support multi-homed hosts */
@@ -1873,7 +1857,6 @@ static int dlm_tcp_listen_bind(struct socket *sock)
 static const struct dlm_proto_ops dlm_tcp_ops = {
 	.name = "TCP",
 	.proto = IPPROTO_TCP,
-	.connect = dlm_tcp_connect,
 	.sockopts = dlm_tcp_sockopts,
 	.bind = dlm_tcp_bind,
 	.listen_validate = dlm_tcp_listen_validate,
@@ -1886,22 +1869,6 @@ static int dlm_sctp_bind(struct socket *sock)
 	return sctp_bind_addrs(sock, 0);
 }
 
-static int dlm_sctp_connect(struct connection *con, struct socket *sock,
-			    struct sockaddr *addr, int addr_len)
-{
-	int ret;
-
-	/*
-	 * Make kernel_connect() function return in specified time,
-	 * since O_NONBLOCK argument in connect() function does not work here,
-	 * then, we should restore the default value of this attribute.
-	 */
-	sock_set_sndtimeo(sock->sk, 5);
-	ret = kernel_connect(sock, addr, addr_len, 0);
-	sock_set_sndtimeo(sock->sk, 0);
-	return ret;
-}
-
 static int dlm_sctp_listen_validate(void)
 {
 	if (!IS_ENABLED(CONFIG_IP_SCTP)) {
@@ -1929,7 +1896,6 @@ static const struct dlm_proto_ops dlm_sctp_ops = {
 	.name = "SCTP",
 	.proto = IPPROTO_SCTP,
 	.try_new_addr = true,
-	.connect = dlm_sctp_connect,
 	.sockopts = dlm_sctp_sockopts,
 	.bind = dlm_sctp_bind,
 	.listen_validate = dlm_sctp_listen_validate,