wd: make watchdog device configurable

Add configuration option resources.watchdog_device allowing runtime
selection of watchdog device.  Useful for newer servers having more
than one watchdog available (IPMI and iTCO).

Special value "off" disables watchdog in configuration rather than
just using build options.  Useful when watchdog device is needed
elsewhere (SBD cluster stonith service).

Signed-off-by: Valentin Vidic <Valentin.Vidic@CARNet.hr>
Reviewed-by: Jan Friesse <jfriesse@redhat.com>

exec/wd.c

@@ -89,6 +89,7 @@ static uint64_t tickle_timeout = (WD_DEFAULT_TIMEOUT_MS / 2);
 static int dog = -1;
 static corosync_timer_handle_t wd_timer;
 static int watchdog_ok = 1;
+static char *watchdog_device = "/dev/watchdog";
 
 struct corosync_service_engine wd_service_engine = {
 	.name			= "corosync watchdog service",
@@ -629,20 +630,33 @@ static void watchdog_timeout_apply (uint32_t new)
 static int setup_watchdog(void)
 {
 	struct watchdog_info ident;
+	char *str;
 
 	ENTER();
-	if (access ("/dev/watchdog", W_OK) != 0) {
-		log_printf (LOGSYS_LEVEL_WARNING, "No Watchdog, try modprobe <a watchdog>");
+
+	if (icmap_get_string("resources.watchdog_device", &str) == CS_OK) {
+		if (strcmp (str, "off") == 0) {
+			log_printf (LOGSYS_LEVEL_WARNING, "Watchdog disabled by configuration");
+			free(str);
+			dog = -1;
+			return -1;
+		} else {
+			watchdog_device = str;
+		}
+	}
+
+	if (access (watchdog_device, W_OK) != 0) {
+		log_printf (LOGSYS_LEVEL_WARNING, "No Watchdog %s, try modprobe <a watchdog>", watchdog_device);
 		dog = -1;
 		return -1;
 	}
 
 	/* here goes, lets hope they have "Magic Close"
 	 */
-	dog = open("/dev/watchdog", O_WRONLY);
+	dog = open(watchdog_device, O_WRONLY);
 
 	if (dog == -1) {
-		log_printf (LOGSYS_LEVEL_WARNING, "Watchdog exists but couldn't be opened.");
+		log_printf (LOGSYS_LEVEL_WARNING, "Watchdog %s exists but couldn't be opened.", watchdog_device);
 		dog = -1;
 		return -1;
 	}
@@ -652,7 +666,7 @@ static int setup_watchdog(void)
 	 */
 
 	ioctl(dog, WDIOC_GETSUPPORT, &ident);
-	log_printf (LOGSYS_LEVEL_INFO, "Watchdog is now been tickled by corosync.");
+	log_printf (LOGSYS_LEVEL_INFO, "Watchdog %s is now been tickled by corosync.", watchdog_device);
 	log_printf (LOGSYS_LEVEL_DEBUG, "%s", ident.identity);
 
 	watchdog_timeout_apply (watchdog_timeout);