lvmlockd: improve systemd service file

use notify type so the daemon is ready
immediately after start.

daemons/lvmlockd/Makefile.in

@@ -15,6 +15,8 @@ srcdir = @srcdir@
 top_srcdir = @top_srcdir@
 top_builddir = @top_builddir@
 
+USE_SD_NOTIFY=yes
+
 SOURCES = lvmlockd-core.c
 
 ifeq ("@BUILD_LOCKDSANLOCK@", "yes")
@@ -40,6 +42,12 @@ INCLUDES += -I$(top_srcdir)/libdaemon/server
 LDFLAGS += -L$(top_builddir)/libdaemon/server $(EXTRA_EXEC_LDFLAGS) $(ELDFLAGS)
 LIBS += $(RT_LIBS) $(DAEMON_LIBS) $(PTHREAD_LIBS)
 
+
+ifeq ($(USE_SD_NOTIFY),yes)
+	CFLAGS += $(shell pkg-config --cflags libsystemd) -DUSE_SD_NOTIFY
+	LDFLAGS += $(shell pkg-config --libs libsystemd)
+endif
+
 lvmlockd: $(OBJECTS) $(top_builddir)/libdaemon/client/libdaemonclient.a \
 		    $(top_builddir)/libdaemon/server/libdaemonserver.a
 	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJECTS) $(LOCK_LIBS) -ldaemonserver $(INTERNAL_LIBS) $(LIBS)

daemons/lvmlockd/lvmlockd-core.c

@@ -35,6 +35,10 @@
 #include <sys/utsname.h>
 #include <sys/un.h>
 
+#ifdef USE_SD_NOTIFY
+#include <systemd/sd-daemon.h>
+#endif
+
 #define EXTERN
 #include "lvmlockd-internal.h"
 
@@ -5786,6 +5790,10 @@ static int main_loop(daemon_state *ds_arg)
 	setup_worker_thread();
 	setup_restart();
 
+#ifdef USE_SD_NOTIFY
+	sd_notify(0, "READY=1");
+#endif
+
 	/*
 	 * Attempt to rejoin lockspaces and adopt locks from a previous
 	 * instance of lvmlockd that left behind lockspaces/locks.

scripts/lvm2_lvmlockd_systemd_red_hat.service.in

@@ -1,13 +1,10 @@
 [Unit]
-Description=LVM2 lock daemon
+Description=LVM lock daemon
 Documentation=man:lvmlockd(8)
-After=lvm2-lvmetad.service
 
 [Service]
-Type=simple
-NonBlocking=true
-ExecStart=@SBINDIR@/lvmlockd -f
-Environment=SD_ACTIVATION=1
+Type=notify
+ExecStart=@SBINDIR@/lvmlockd --foreground
 PIDFile=@LVMLOCKD_PIDFILE@
 SendSIGKILL=no