fs: dlm: introduce proto values

Currently the dlm protocol values are that TCP is 0 and everything else
is SCTP. This makes it difficult to introduce possible other transport
layers. The only one user space tool dlm_controld, which I am aware of,
handles the protocol value 1 for SCTP. We change it now to handle SCTP
as 1, this will break user space API but it will fix it so we can add
possible other transport layers.

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

Author: Alexander Aring

fs/dlm/config.c

@@ -952,7 +952,7 @@ int dlm_our_addr(struct sockaddr_storage *addr, int num)
 #define DEFAULT_SCAN_SECS          5
 #define DEFAULT_LOG_DEBUG          0
 #define DEFAULT_LOG_INFO           1
-#define DEFAULT_PROTOCOL           0
+#define DEFAULT_PROTOCOL           DLM_PROTO_TCP
 #define DEFAULT_MARK               0
 #define DEFAULT_TIMEWARN_CS      500 /* 5 sec = 500 centiseconds */
 #define DEFAULT_WAITWARN_US	   0

fs/dlm/config.h

@@ -23,6 +23,9 @@ struct dlm_config_node {
 
 #define DLM_MAX_ADDR_COUNT 3
 
+#define DLM_PROTO_TCP	0
+#define DLM_PROTO_SCTP	1
+
 struct dlm_config_info {
 	int ci_tcp_port;
 	int ci_buffer_size;

fs/dlm/lowcomms.c

@@ -208,12 +208,18 @@ static int dlm_con_init(struct connection *con, int nodeid)
 	INIT_WORK(&con->rwork, process_recv_sockets);
 	init_waitqueue_head(&con->shutdown_wait);
 
-	if (dlm_config.ci_protocol == 0) {
+	switch (dlm_config.ci_protocol) {
+	case DLM_PROTO_TCP:
 		con->connect_action = tcp_connect_to_sock;
 		con->shutdown_action = dlm_tcp_shutdown;
 		con->eof_condition = tcp_eof_condition;
-	} else {
+		break;
+	case DLM_PROTO_SCTP:
 		con->connect_action = sctp_connect_to_sock;
+		break;
+	default:
+		kfree(con->rx_buf);
+		return -EINVAL;
 	}
 
 	return 0;
@@ -1968,10 +1974,19 @@ int dlm_lowcomms_start(void)
 	dlm_allow_conn = 1;
 
 	/* Start listening */
-	if (dlm_config.ci_protocol == 0)
+	switch (dlm_config.ci_protocol) {
+	case DLM_PROTO_TCP:
 		error = tcp_listen_for_all();
-	else
+		break;
+	case DLM_PROTO_SCTP:
 		error = sctp_listen_for_all(&listen_con);
+		break;
+	default:
+		log_print("Invalid protocol identifier %d set",
+			  dlm_config.ci_protocol);
+		error = -EINVAL;
+		break;
+	}
 	if (error)
 		goto fail_unlisten;