Medium: nfsserver: fix monitor for systemd

use the number of nfsd threads for monitor instead of systemctl when using systemctl and running nfsd process.
The systemctl doesn't monitor the running kernel process like nfsd.
So if nfsd process is failure, nfsserver_monitor doesn't detect it.

heartbeat/nfsserver

@@ -293,10 +293,42 @@ v3locking_exec()
 	fi
 }
 
+nfsserver_systemd_monitor()
+{
+	local threads_num
+	local rc
+
+	nfs_exec is-active
+	rc=$?
+
+	# Now systemctl is-active can't detect the failure of kernel process like nfsd.
+	# So, if the return value of systemctl is-active is 0, check the threads number
+	# to make sure the process is running really.
+	# /proc/fs/nfsd/threads has the numbers of the nfsd threads.
+	if [ $rc -eq 0 ]; then
+		threads_num=`cat /proc/fs/nfsd/threads 2>/dev/null`
+		if [ $? -eq 0 ]; then
+			if [ $threads_num -gt 0 ]; then
+				return $OCF_SUCCESS
+			else
+				return 3
+			fi
+		else
+			return $OCF_ERR_GENERIC
+		fi
+	fi
+
+	return $rc
+}
+
 nfsserver_monitor ()
 {
+	set_exec_mode
 	fn=`mktemp`
-	nfs_exec status > $fn 2>&1 
+	case $EXEC_MODE in
+               1) nfs_exec status > $fn 2>&1;;
+            [23]) nfsserver_systemd_monitor > $fn 2>&1;;
+	esac
 	rc=$?
 	ocf_log debug "$(cat $fn)"
 	rm -f $fn