Introduce two new functions to be used on locking.

- try_lock: used for trying to get an EXCLUSIVE lock for a specified timeout by default of 5
- unlock_force: which just releases any locks held on a specified lock

Use this new functions on rc.openvpn to avoid spurious stale locks around.

2 files changed, 40 insertions, 1 deletions

diff --git a/etc/inc/util.inc b/etc/inc/util.inc
index e75b5cb..c276c21 100644
--- a/etc/inc/util.inc
+++ b/etc/inc/util.inc
@@ -132,6 +132,32 @@ function lock($lock, $op = LOCK_SH) {
 	}
 }
 
+function try_lock($lock, $timeout = 5) {
+	global $g, $cfglckkeyconsumers;
+	if (!$lock)
+		die(gettext("WARNING: You must give a name as parameter to try_lock() function."));
+	if (!file_exists("{$g['tmp_path']}/{$lock}.lock")) {
+		@touch("{$g['tmp_path']}/{$lock}.lock");
+		@chmod("{$g['tmp_path']}/{$lock}.lock", 0666);
+	}
+	$cfglckkeyconsumers++;
+	if ($fp = fopen("{$g['tmp_path']}/{$lock}.lock", "w")) {
+		$trycounter = 0;
+		while(!flock($fp, LOCK_EX | LOCK_NB)) {
+			if ($trycounter >= $timeout) {
+				fclose($fp);
+				return NULL;
+			}
+			sleep(1);
+			$trycounter++;
+		}
+
+		return $fp;
+	}
+
+	return NULL;
+}
+
 /* unlock configuration file */
 function unlock($cfglckkey = 0) {
 	global $g, $cfglckkeyconsumers;
@@ -140,6 +166,13 @@ function unlock($cfglckkey = 0) {
 	return;
 }
 
+/* unlock forcefully configuration file */
+function unlock_force($lock) {
+	global $g;
+
+	@unlink("{$g['tmp_path']}/{$lock}.lock");
+}
+
 function send_event($cmd) {
 	global $g;
 
diff --git a/etc/rc.openvpn b/etc/rc.openvpn
index 4cabffe..f60ad56 100755
--- a/etc/rc.openvpn
+++ b/etc/rc.openvpn
@@ -80,7 +80,13 @@ if(is_array($config['openvpn']['openvpn-server']) || is_array($config['openvpn']
 } else
 	return;
 
-$openvpnlck = lock('openvpn', LOCK_EX);
+$openvpnlck = try_lock('openvpn', 10);
+if (!$openvpnlck) {
+	log_error(gettext("Could not obtain openvpn lock for executing rc.openvpn for more than 10 seconds continuing..."));
+	unlock_force('openvpn');
+	$openvpnlck = lock('openvpn', LOCK_EX);
+}
+
 $arg_array = explode(",",$argument);
 foreach ($arg_array as $arg_element) {
 	$gwgroups = array();