add fixed event activation services

System startup runs two new fixed activation services:
lvm-activate-vgs-main and lvm-activate-vgs-last

These activate VGs that are present and complete at the
time of system startup.

The last service enables event activation by creating
the file /run/lvm/event-activation-on.  After that,
new devices that appear will be processed by event based
activation.

lvm.conf event_activation_options can be used to
configure service-based activation only, or event-based
activation only, or the default hybrid approach.

19 files changed, 411 insertions, 87 deletions

diff --git a/configure.ac b/configure.ac
index 31196d96c..ac9f17a31 100644
--- a/configure.ac
+++ b/configure.ac
@@ -773,39 +773,6 @@ AC_DEFINE_UNQUOTED(DEFAULT_RUN_DIR, ["$DEFAULT_RUN_DIR"],
 		   [Default LVM run directory.])
 
 ################################################################################
-dnl -- Build cluster mirror log daemon
-AC_MSG_CHECKING(whether to build cluster mirror log daemon)
-AC_ARG_ENABLE(cmirrord,
-	      AS_HELP_STRING([--enable-cmirrord],
-			     [enable the cluster mirror log daemon]),
-	      CMIRRORD=$enableval, CMIRRORD=no)
-AC_MSG_RESULT($CMIRRORD)
-
-BUILD_CMIRRORD=$CMIRRORD
-
-################################################################################
-dnl -- cmirrord pidfile
-if test "$BUILD_CMIRRORD" = yes; then
-	AC_ARG_WITH(cmirrord-pidfile,
-		    AS_HELP_STRING([--with-cmirrord-pidfile=PATH],
-				   [cmirrord pidfile [PID_DIR/cmirrord.pid]]),
-		    CMIRRORD_PIDFILE=$withval,
-		    CMIRRORD_PIDFILE="$DEFAULT_PID_DIR/cmirrord.pid")
-	AC_DEFINE_UNQUOTED(CMIRRORD_PIDFILE, ["$CMIRRORD_PIDFILE"],
-			   [Path to cmirrord pidfile.])
-fi
-
-################################################################################
-dnl -- Look for corosync libraries if required.
-if [[ "$BUILD_CMIRRORD" = yes ]]; then
-	pkg_config_init
-
-	if test "$HAVE_CPG" != yes; then
-		PKG_CHECK_MODULES(CPG, libcpg)
-	fi
-fi
-
-################################################################################
 dnl -- Enable debugging
 AC_MSG_CHECKING(whether to enable debugging)
 AC_ARG_ENABLE(debug, AS_HELP_STRING([--enable-debug], [enable debugging]),
@@ -1642,10 +1609,6 @@ fi
 AC_MSG_CHECKING(whether to enable editline)
 AC_MSG_RESULT($EDITLINE)
 
-if test "$BUILD_CMIRRORD" = yes; then
-	AC_CHECK_FUNCS(atexit,,hard_bailout)
-fi
-
 if test "$BUILD_LVMLOCKD" = yes; then
 	AS_IF([test "$HAVE_REALTIME" != yes], [AC_MSG_ERROR([Realtime clock support is mandatory for lvmlockd.])])
 	AC_CHECK_FUNCS(strtoull,,hard_bailout)
@@ -1808,7 +1771,6 @@ AC_DEFINE_UNQUOTED(LVM_CONFIGURE_LINE, "$CONFIGURE_LINE", [configure command lin
 ################################################################################
 AC_SUBST(AWK)
 AC_SUBST(BLKID_PC)
-AC_SUBST(BUILD_CMIRRORD)
 AC_SUBST(BUILD_DMEVENTD)
 AC_SUBST(BUILD_LVMDBUSD)
 AC_SUBST(BUILD_LVMPOLLD)
@@ -1946,7 +1908,6 @@ AC_SUBST(WRITE_INSTALL)
 AC_SUBST(DMEVENTD_PIDFILE)
 AC_SUBST(LVMPOLLD_PIDFILE)
 AC_SUBST(LVMLOCKD_PIDFILE)
-AC_SUBST(CMIRRORD_PIDFILE)
 AC_SUBST(interface)
 AC_SUBST(kerneldir)
 AC_SUBST(missingkernel)
@@ -1968,7 +1929,6 @@ Makefile
 make.tmpl
 libdm/make.tmpl
 daemons/Makefile
-daemons/cmirrord/Makefile
 daemons/dmeventd/Makefile
 daemons/dmeventd/libdevmapper-event.pc
 daemons/dmeventd/plugins/Makefile
@@ -2002,14 +1962,14 @@ libdm/libdevmapper.pc
 man/Makefile
 po/Makefile
 scripts/lvm2-pvscan.service
+scripts/lvm-activate-vgs-main.service
+scripts/lvm-activate-vgs-last.service
 scripts/blkdeactivate.sh
 scripts/blk_availability_init_red_hat
 scripts/blk_availability_systemd_red_hat.service
-scripts/cmirrord_init_red_hat
 scripts/com.redhat.lvmdbus1.service
 scripts/dm_event_systemd_red_hat.service
 scripts/dm_event_systemd_red_hat.socket
-scripts/lvm2_cmirrord_systemd_red_hat.service
 scripts/lvm2_lvmdbusd_systemd_red_hat.service
 scripts/lvm2_lvmpolld_init_red_hat
 scripts/lvm2_lvmpolld_systemd_red_hat.service
diff --git a/lib/config/config_settings.h b/lib/config/config_settings.h
index d280e7adb..d2a40f234 100644
--- a/lib/config/config_settings.h
+++ b/lib/config/config_settings.h
@@ -1130,6 +1130,18 @@ cfg(global_event_activation_CFG, "event_activation", global_CFG_SECTION, CFG_DEF
 	"See the --setautoactivation option or the auto_activation_volume_list\n"
 	"setting to configure autoactivation for specific VGs or LVs.\n")
 
+cfg_array(global_event_activation_options_CFG, "event_activation_options", global_CFG_SECTION, CFG_ALLOW_EMPTY | CFG_DEFAULT_COMMENTED, CFG_TYPE_STRING, DEFAULT_EVENT_ACTIVATION_OPTIONS, vsn(2, 3, 14), NULL, 0, NULL,
+	"Set event activation options.\n"
+	"service_to_event: begin with fixed activation services,\n"
+	"then switch to event based activation.\n"
+	"event_only: only use event based activation.\n"
+	"service_only: only use fixed activation services.\n"
+	"(This is equivalent to event_activation=0.)\n"
+	"Autoactivation commands should set --eventactivation service|event\n"
+	"to indicate if they are performing service or event activation.\n"
+	"An autoactivation command may then be skipped according to the\n"
+	"value of this setting.\n")
+
 cfg(global_use_lvmetad_CFG, "use_lvmetad", global_CFG_SECTION, CFG_DEFAULT_COMMENTED, CFG_TYPE_BOOL, 0, vsn(2, 2, 93), 0, vsn(2, 3, 0), NULL,
 	NULL)
 
diff --git a/lib/config/defaults.h b/lib/config/defaults.h
index a7a2a06df..e748ebb67 100644
--- a/lib/config/defaults.h
+++ b/lib/config/defaults.h
@@ -329,4 +329,7 @@
 
 #define DEFAULT_WWIDS_FILE "/etc/multipath/wwids"
 
+#define DEFAULT_EVENT_ACTIVATION_OPTION1 "service_to_event"
+#define DEFAULT_EVENT_ACTIVATION_OPTIONS "#S" DEFAULT_EVENT_ACTIVATION_OPTION1
+
 #endif				/* _LVM_DEFAULTS_H */
diff --git a/lib/label/label.c b/lib/label/label.c
index b5804c738..6815eb3ad 100644
--- a/lib/label/label.c
+++ b/lib/label/label.c
@@ -1129,6 +1129,9 @@ int label_scan(struct cmd_context *cmd)
 			}
 		}
 	}
+
+	log_debug_devs("Filtering devices to scan done (nodata)");
+
 	cmd->filter_nodata_only = 0;
 
 	dm_list_iterate_items(devl, &all_devs)
diff --git a/scripts/Makefile.in b/scripts/Makefile.in
index 0d7f45680..bc567555e 100644
--- a/scripts/Makefile.in
+++ b/scripts/Makefile.in
@@ -15,9 +15,6 @@ srcdir = @srcdir@
 top_srcdir = @top_srcdir@
 top_builddir = @top_builddir@
 
-SOURCES = lvm2_activation_generator_systemd_red_hat.c
-TARGETS = lvm2_activation_generator_systemd_red_hat
-
 include $(top_builddir)/make.tmpl
 
 ifeq ("@BUILD_DMEVENTD@", "yes")
@@ -66,7 +63,7 @@ install_initscripts:
 	@echo "    [INSTALL] initscripts"
 	$(Q) $(INSTALL_DIR) $(initdir)
 ifeq ("@BUILD_DMEVENTD@", "yes")
-	$(Q) $(INSTALL_SCRIPT) lvm2_monitoring_init_red_hat $(initdir)/lvm2-monitor
+	$(Q) $(INSTALL_SCRIPT) lvm2_monitoring_init_red_hat $(initdir)/lvm-monitor
 endif
 ifeq ("@BUILD_LVMPOLLD@", "yes")
 	$(Q) $(INSTALL_SCRIPT) lvm2_lvmpolld_init_red_hat $(initdir)/lvm2-lvmpolld
@@ -78,24 +75,15 @@ ifeq ("@BLKDEACTIVATE@", "yes")
 	$(Q) $(INSTALL_SCRIPT) blk_availability_init_red_hat $(initdir)/blk-availability
 endif
 
-CFLAGS_lvm2_activation_generator_systemd_red_hat.o += $(EXTRA_EXEC_CFLAGS)
-
-lvm2_activation_generator_systemd_red_hat: $(OBJECTS) $(LVMINTERNAL_LIBS)
-	@echo "    [CC] $@"
-	$(Q) $(CC) -o $@ $(OBJECTS) $(CFLAGS) $(LDFLAGS) $(EXTRA_EXEC_LDFLAGS) $(ELDFLAGS) $(LVMINTERNAL_LIBS) $(LIBS)
-
-install_systemd_generators:
-	@echo "    [INSTALL] systemd_generators"
-	$(Q) $(INSTALL_DIR) $(systemd_generator_dir)
-	$(Q) $(INSTALL_PROGRAM) lvm2_activation_generator_systemd_red_hat $(systemd_generator_dir)/lvm2-activation-generator
-
 install_systemd_units:	install_dbus_service
 	@echo "    [INSTALL] systemd_units"
 	$(Q) $(INSTALL_DIR) $(systemd_unit_dir)
+	$(Q) $(INSTALL_DATA) lvm-activate-vgs-main.service $(systemd_unit_dir)/lvm-activate-vgs-main.service
+	$(Q) $(INSTALL_DATA) lvm-activate-vgs-last.service $(systemd_unit_dir)/lvm-activate-vgs-last.service
 ifeq ("@BUILD_DMEVENTD@", "yes")
 	$(Q) $(INSTALL_DATA) dm_event_systemd_red_hat.socket $(systemd_unit_dir)/dm-event.socket
 	$(Q) $(INSTALL_DATA) dm_event_systemd_red_hat.service $(systemd_unit_dir)/dm-event.service
-	$(Q) $(INSTALL_DATA) lvm2_monitoring_systemd_red_hat.service $(systemd_unit_dir)/lvm2-monitor.service
+	$(Q) $(INSTALL_DATA) lvm2_monitoring_systemd_red_hat.service $(systemd_unit_dir)/lvm-monitor.service
 endif
 ifeq ("@BLKDEACTIVATE@", "yes")
 	$(Q) $(INSTALL_DATA) blk_availability_systemd_red_hat.service $(systemd_unit_dir)/blk-availability.service
@@ -155,7 +143,9 @@ DISTCLEAN_TARGETS += \
 	lvm2_monitoring_init_red_hat \
 	lvm2_monitoring_systemd_red_hat.service \
 	lvm2_pvscan_systemd_red_hat@.service \
-	lvm2_tmpfiles_red_hat.conf
+	lvm2_tmpfiles_red_hat.conf \
+	lvm-activate-vgs-main.service \
+	lvm-activate-vgs-last.service
 
 # Remove ancient files
 DISTCLEAN_TARGETS += \
diff --git a/scripts/blk_availability_systemd_red_hat.service.in b/scripts/blk_availability_systemd_red_hat.service.in
index 82d3b82d0..e42b3ab5f 100644
--- a/scripts/blk_availability_systemd_red_hat.service.in
+++ b/scripts/blk_availability_systemd_red_hat.service.in
@@ -1,7 +1,7 @@
 [Unit]
 Description=Availability of block devices
 Before=shutdown.target
-After=lvm2-activation.service iscsi-shutdown.service iscsi.service iscsid.service fcoe.service rbdmap.service
+After=lvm-activate-vgs-main.service lvm-activate-vgs-last.service iscsi-shutdown.service iscsi.service iscsid.service fcoe.service rbdmap.service
 DefaultDependencies=no
 Conflicts=shutdown.target
 
diff --git a/scripts/lvm-activate-vgs-last.service.in b/scripts/lvm-activate-vgs-last.service.in
new file mode 100644
index 000000000..76eea5a8c
--- /dev/null
+++ b/scripts/lvm-activate-vgs-last.service.in
@@ -0,0 +1,22 @@
+[Unit]
+Description=Activate LVM Volume Groups (last)
+Documentation=man:vgchange(8)
+Wants=systemd-udev-settle.service
+After=lvm-activate-vgs-main.service systemd-udev-settle.service multipathd.service cryptsetup.target
+Before=local-fs-pre.target shutdown.target
+DefaultDependencies=no
+Conflicts=shutdown.target
+
+# "--eventactivation service" tells vgchange it is being called
+# from an activation service, so it will do nothing if
+# lvm.conf event_activation_options = "event_only".
+# "--eventactivation on" tells vgchange to enable event-based
+# pvscan activations by creating /run/lvm/event-activation-on.
+
+[Service]
+Type=oneshot
+ExecStart=@SBINDIR@/lvm vgchange -aay --nohints --vgonline --eventactivation service,on
+RemainAfterExit=yes
+
+[Install]
+WantedBy=sysinit.target
diff --git a/scripts/lvm-activate-vgs-main.service.in b/scripts/lvm-activate-vgs-main.service.in
new file mode 100644
index 000000000..94aad8426
--- /dev/null
+++ b/scripts/lvm-activate-vgs-main.service.in
@@ -0,0 +1,19 @@
+[Unit]
+Description=Activate LVM Volume Groups
+Documentation=man:vgchange(8)
+After=dm-event.socket dm-event.service
+Before=local-fs-pre.target shutdown.target
+DefaultDependencies=no
+Conflicts=shutdown.target
+
+# "--eventactivation service" tells vgchange it is being called 
+# from an activation service, so it will do nothing if
+# lvm.conf event_activation_options = "event_only".
+
+[Service]
+Type=oneshot
+ExecStart=@SBINDIR@/lvm vgchange -aay --nohints --vgonline --eventactivation service
+RemainAfterExit=yes
+
+[Install]
+WantedBy=sysinit.target
diff --git a/scripts/lvm2_monitoring_systemd_red_hat.service.in b/scripts/lvm2_monitoring_systemd_red_hat.service.in
index 4bf744a7f..e912c6a85 100644
--- a/scripts/lvm2_monitoring_systemd_red_hat.service.in
+++ b/scripts/lvm2_monitoring_systemd_red_hat.service.in
@@ -1,8 +1,8 @@
 [Unit]
-Description=Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling
+Description=Monitor LVM Logical Volumes
 Documentation=man:dmeventd(8) man:lvcreate(8) man:lvchange(8) man:vgchange(8)
 Requires=dm-event.socket
-After=dm-event.socket dm-event.service lvm2-activation.service
+After=dm-event.socket dm-event.service lvm-activate-vgs-last.service
 Before=local-fs-pre.target shutdown.target
 DefaultDependencies=no
 Conflicts=shutdown.target
diff --git a/spec/packages.inc b/spec/packages.inc
index 74d795520..3d6ef2de9 100644
--- a/spec/packages.inc
+++ b/spec/packages.inc
@@ -23,10 +23,10 @@ if [ $1 = 0 ]; then
 fi
 
 %triggerun -- %{name} < 2.02.86-2
-%{_bindir}/systemd-sysv-convert --save lvm2-monitor >/dev/null 2>&1 || :
-/bin/systemctl --no-reload enable lvm2-monitor.service > /dev/null 2>&1 || :
-/sbin/chkconfig --del lvm2-monitor > /dev/null 2>&1 || :
-/bin/systemctl try-restart lvm2-monitor.service > /dev/null 2>&1 || :
+%{_bindir}/systemd-sysv-convert --save lvm-monitor >/dev/null 2>&1 || :
+/bin/systemctl --no-reload enable lvm-monitor.service > /dev/null 2>&1 || :
+/sbin/chkconfig --del lvm-monitor > /dev/null 2>&1 || :
+/bin/systemctl try-restart lvm-monitor.service > /dev/null 2>&1 || :
 # files in the main package
 
 %files
@@ -100,9 +100,6 @@ fi
 %{_mandir}/man8/lvm-config.8.gz
 %{_mandir}/man8/lvm-dumpconfig.8.gz
 %{_mandir}/man8/lvm.8.gz
-%if %{enable_systemd}
- %{_mandir}/man8/lvm2-activation-generator.8.gz
-%endif
 %{_mandir}/man8/lvmconfig.8.gz
 %{_mandir}/man8/lvmdevices.8.gz
 %{_mandir}/man8/lvmdiskscan.8.gz
@@ -187,16 +184,17 @@ fi
 %dir %{_default_run_dir}
 %if %{enable_systemd}
  %{_tmpfilesdir}/%{name}.conf
+ %{_unitdir}/lvm-activate-vgs-main.service
+ %{_unitdir}/lvm-activate-vgs-last.service
+ %{_unitdir}/lvm-monitor.service
  %{_unitdir}/blk-availability.service
- %{_unitdir}/lvm2-monitor.service
- %attr(555, -, -) %{_prefix}/lib/systemd/system-generators/lvm2-activation-generator
  %if %{have_service lvmpolld}
   %{_unitdir}/lvm2-lvmpolld.service
   %{_unitdir}/lvm2-lvmpolld.socket
  %endif
 %else
  %{_sysconfdir}/rc.d/init.d/blk-availability
- %{_sysconfdir}/rc.d/init.d/lvm2-monitor
+ %{_sysconfdir}/rc.d/init.d/lvm-monitor
  %if %{have_service lvmpolld}
   %{_sysconfdir}/rc.d/init.d/lvm2-lvmpolld
  %endif
diff --git a/tools/args.h b/tools/args.h
index 774ce33f4..f7a4fc6f7 100644
--- a/tools/args.h
+++ b/tools/args.h
@@ -278,6 +278,11 @@ arg(errorwhenfull_ARG, '\0', "errorwhenfull", bool_VAL, 0, 0,
     "(Also see dm-thin-pool kernel module option no_space_timeout.)\n"
     "See \\fBlvmthin\\fP(7) for more information.\n")
 
+arg(eventactivation_ARG, '\0', "eventactivation", string_VAL, 0, 0,
+    "Specify if the command is running autoactivation from an event\n"
+    "or a fixed service. The lvm.conf event_activation_options setting\n"
+    "determines if event or service based activation commands are used.\n")
+
 arg(force_long_ARG, '\0', "force", 0, ARG_COUNTABLE, 0,
     "Force metadata restore even with thin pool LVs.\n"
     "Use with extreme caution. Most changes to thin metadata\n"
diff --git a/tools/command-lines.in b/tools/command-lines.in
index 23ea33e6d..6e00f22b4 100644
--- a/tools/command-lines.in
+++ b/tools/command-lines.in
@@ -1642,14 +1642,15 @@ DESC: Record that a PV is online or offline.
 
 pvscan --cache_long --activate ay
 OO: --ignorelockingfailure, --reportformat ReportFmt,
---major Number, --minor Number, --noudevsync
+--major Number, --minor Number, --noudevsync, --eventactivation String
 OP: PV|String ...
 IO: --background
 ID: pvscan_cache
 DESC: Record that a PV is online and autoactivate the VG if complete.
 
 pvscan --cache_long --listvg PV
-OO: --ignorelockingfailure, --checkcomplete, --vgonline, --udevoutput
+OO: --ignorelockingfailure, --checkcomplete, --vgonline, --udevoutput,
+--eventactivation String
 ID: pvscan_cache
 DESC: Record that a PV is online and list the VG using the PV.
 
@@ -1747,7 +1748,8 @@ DESC: Start or stop processing LV conversions.
 
 vgchange --activate Active
 OO: --activationmode ActivationMode, --ignoreactivationskip, --partial, --sysinit,
---readonly, --ignorelockingfailure, --monitor Bool, --poll Bool, --vgonline, OO_VGCHANGE
+--readonly, --ignorelockingfailure, --monitor Bool, --poll Bool,
+--vgonline, --eventactivation String, OO_VGCHANGE
 OP: VG|Tag|Select ...
 IO: --ignoreskippedcluster
 ID: vgchange_activate
diff --git a/tools/pvscan.c b/tools/pvscan.c
index ada1f07fe..625aedb9f 100644
--- a/tools/pvscan.c
+++ b/tools/pvscan.c
@@ -46,6 +46,8 @@ static const char *_pvs_online_dir = DEFAULT_RUN_DIR "/pvs_online";
 static const char *_vgs_online_dir = DEFAULT_RUN_DIR "/vgs_online";
 static const char *_pvs_lookup_dir = DEFAULT_RUN_DIR "/pvs_lookup";
 
+static const char *_event_activation_file = DEFAULT_RUN_DIR "/event-activation-on";
+
 static int _pvscan_display_pv(struct cmd_context *cmd,
 				  struct physical_volume *pv,
 				  struct pvscan_params *params)
@@ -180,6 +182,84 @@ out:
 }
 
 /*
+ * Event based activation
+ * lvm.conf event_activation_options = "event_only"
+ * . all events are used for activation
+ * . no fixed services are used for activation
+ * . lvm.conf event_activation=1 required
+ *
+ * vgchange -aay --eventactivation service
+ * . does nothing
+ * vgchange -aay --eventactivation event
+ * . does activation
+ * pvscan --eventactivation event
+ * . does activation
+ *
+ * ---
+ *
+ * Non-event based activation
+ * lvm.conf event_activation_options = "service_only"
+ * . fixed services are used for activation
+ * . no events are used for activation
+ * . lvm.conf event_activation=0 is equivalent to
+ *   event_activation=1 event_activation_options="service_only"
+ *
+ * vgchange -aay --eventactivation service
+ * . does activation
+ * vgchange -aay --eventactivation event
+ * . does nothing
+ * pvscan --eventactivation event
+ * . does nothing
+ *
+ * ---
+ *
+ * Mix of event and non-event based activation
+ * lvm.conf event_activation_options = "service_to_event"
+ * . both services and events are used for activation
+ * . fixed services are used for activation initially,
+ *   and last service enables event based activation
+ *   by creating the event-activation-on file
+ *
+ * vgchange -aay --eventactivation service
+ * . does activation only if event-activation-on does not exist
+ * vgchange -aay --eventactivation event
+ * . does activation only if event-activation-on exists
+ * vgchange -aay --eventactivation service,on
+ * . does activation only if event-activation-on does not exist
+ * . creates event-activation-on to enable event-based activation
+ * vgchange --eventactivation on|off
+ * . create or remove event-activation-on to enable|disable
+ *   event-based activation
+ * pvscan --eventactivation event
+ * . does activation only if event-activation-on exists
+ *
+ */
+
+int event_activation_enable(struct cmd_context *cmd)
+{
+	FILE *fp;
+
+	if (!(fp = fopen(_event_activation_file, "w")))
+		return_0;
+	if (fclose(fp))
+                stack;
+	return 1;
+}
+
+int event_activation_is_on(struct cmd_context *cmd)
+{
+	struct stat buf;
+
+	if (!stat(_event_activation_file, &buf))
+		return 1;
+
+	if (errno != ENOENT)
+		log_debug("event_activation_is_on errno %d", errno);
+
+	return 0;
+}
+
+/*
  * Avoid a duplicate pvscan[%d] prefix when logging to the journal.
  * FIXME: this should probably replace if (udevoutput) with
  * if (log_journal & LOG_JOURNAL_OUTPUT)
@@ -367,7 +447,7 @@ static void _online_files_remove(const char *dirpath)
 		log_sys_debug("closedir", dirpath);
 }
 
-static int _online_pvid_file_create(struct cmd_context *cmd, struct device *dev, const char *vgname)
+int online_pvid_file_create(struct cmd_context *cmd, struct device *dev, const char *vgname, int ignore_existing, int *exists)
 {
 	char path[PATH_MAX];
 	char buf[MAX_PVID_FILE_SIZE] = { 0 };
@@ -407,8 +487,13 @@ static int _online_pvid_file_create(struct cmd_context *cmd, struct device *dev,
 
 	fd = open(path, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
 	if (fd < 0) {
-		if (errno == EEXIST)
+		if (errno == EEXIST) {
+			if (exists)
+				*exists = 1;
+			if (ignore_existing)
+				return 1;
 			goto check_duplicate;
+		}
 		log_error_pvscan(cmd, "Failed to create online file for %s path %s error %d", dev_name(dev), path, errno);
 		return 0;
 	}
@@ -427,7 +512,6 @@ static int _online_pvid_file_create(struct cmd_context *cmd, struct device *dev,
 	}
 
 	/* We don't care about syncing, these files are not even persistent. */
-
 	if (close(fd))
 		log_sys_debug("close", path);
 
@@ -1412,7 +1496,7 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 		 * Create file named for pvid to record this PV is online.
 		 * The command creates/checks online files only when --cache is used.
 		 */
-		if (do_cache && !_online_pvid_file_create(cmd, dev, vg ? vg->name : NULL)) {
+		if (do_cache && !online_pvid_file_create(cmd, dev, vg ? vg->name : NULL, 0, NULL)) {
 			log_error_pvscan(cmd, "PV %s failed to create online file.", dev_name(dev));
 			release_vg(vg);
 			ret = 0;
@@ -1857,6 +1941,7 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
 {
 	struct pvscan_aa_params pp = { 0 };
 	struct dm_list complete_vgnames;
+	const char *ea;
 	int do_activate = arg_is_set(cmd, activate_ARG);
 	int event_activation;
 	int devno_args = 0;
@@ -1930,6 +2015,36 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
 			log_verbose("Ignoring pvscan --cache because event_activation is disabled.");
 			return ECMD_PROCESSED;
 		}
+
+
+		if ((ea = arg_str_value(cmd, eventactivation_ARG, NULL))) {
+			int service_only = 0, event_only = 0, service_to_event = 0;
+			int ea_service = 0, ea_event = 0, ea_on = 0;
+
+			if (!get_event_activation_config_settings(cmd, &service_only, &event_only, &service_to_event))
+				return ECMD_FAILED;
+			if (!get_event_activation_command_options(cmd, ea, &ea_service, &ea_event, &ea_on))
+				return ECMD_FAILED;
+
+			if (ea_event) {
+				if (!event_activation) {
+					log_print("Skip pvscan for event and event_activation=0.");
+					return ECMD_PROCESSED;
+				}
+				if (service_only) {
+					log_print("Skip pvscan for event and event_activation_options service_only.");
+					return ECMD_PROCESSED;
+				}
+				if (service_to_event && !event_activation_is_on(cmd)) {
+					log_print("Skip pvscan for event and no event-activation-on.");
+					return ECMD_PROCESSED;
+				}
+			} else {
+				log_error("Option --eventactivation %s is not used by pvscan.", ea);
+				return ECMD_FAILED;
+			}
+		}
+
 		if (!_pvscan_cache_args(cmd, argc, argv, &complete_vgnames))
 			return ECMD_FAILED;
 	}
diff --git a/tools/toollib.c b/tools/toollib.c
index 3682dfa0a..b87aef83e 100644
--- a/tools/toollib.c
+++ b/tools/toollib.c
@@ -5829,3 +5829,61 @@ bad:
 out:
 	return 0;
 }
+
+int get_event_activation_config_settings(struct cmd_context *cmd,
+				  int *service_only, int *event_only, int *service_to_event)
+{
+	const struct dm_config_node *cn;
+	const struct dm_config_value *cv;
+	int eo = 0, so = 0, se = 0;
+
+	if (!(cn = find_config_tree_array(cmd, global_event_activation_options_CFG, NULL)))
+                return 1;
+
+	for (cv = cn->v; cv; cv = cv->next) {
+		if (cv->type != DM_CFG_STRING)
+			continue;
+		if (!strcmp(cv->v.str, "service_only"))
+			so = 1;
+		else if (!strcmp(cv->v.str, "event_only"))
+			eo = 1;
+		else if (!strcmp(cv->v.str, "service_to_event"))
+			se = 1;
+		else if (strlen(cv->v.str) > 0)
+			log_warn("WARNING: ignoring unrecognized event_activation_options value %s.", cv->v.str);
+	}
+
+	if (se && (so || eo)) {
+		log_warn("WARNING: ignoring incompatible event_activation_options, using service_to_event.");
+		*service_to_event = 1;
+	} else if (so && eo) {
+		log_warn("WARNING: ignoring incompatible event_activation_options, using event_only.");
+		*event_only = 1;
+	} else if (se) {
+		*service_to_event = 1;
+	} else if (so) {
+		*service_only = 1;
+	} else if (eo) {
+		*event_only = 1;
+	} else {
+		*service_to_event = 1;
+	}
+	return 1;
+}
+
+int get_event_activation_command_options(struct cmd_context *cmd, const char *ea, int *ea_service, int *ea_event, int *ea_on)
+{
+	if (strstr(ea, "service"))
+		*ea_service = 1;
+	if (strstr(ea, "event"))
+		*ea_event = 1;
+	if (strstr(ea, "on"))
+		*ea_on = 1;
+
+	if (*ea_service && *ea_event) {
+		log_error("Invalid --eventactivation options, service and event are incompatible.");
+		return 0;
+	}
+	return 1;
+}
+
diff --git a/tools/toollib.h b/tools/toollib.h
index f3a60fbc4..3f203d309 100644
--- a/tools/toollib.h
+++ b/tools/toollib.h
@@ -237,4 +237,9 @@ int lvremove_single(struct cmd_context *cmd, struct logical_volume *lv,
 
 int get_lvt_enum(struct logical_volume *lv);
 
+int get_event_activation_config_settings(struct cmd_context *cmd,
+		int *service_only, int *event_only, int *service_to_event);
+int get_event_activation_command_options(struct cmd_context *cmd,
+		const char *ea, int *ea_service, int *ea_event, int *ea_on);
+
 #endif
diff --git a/tools/tools.h b/tools/tools.h
index e2661f272..37b7d5a7e 100644
--- a/tools/tools.h
+++ b/tools/tools.h
@@ -295,8 +295,11 @@ int lvconvert_cachevol_attach_single(struct cmd_context *cmd,
                                      struct logical_volume *lv,
                                      struct processing_handle *handle);
 
+int online_pvid_file_create(struct cmd_context *cmd, struct device *dev, const char *vgname, int ignore_existing, int *exists);
 void online_vg_file_remove(const char *vgname);
 int online_vg_file_create(struct cmd_context *cmd, const char *vgname);
 void online_dir_setup(struct cmd_context *cmd);
+int event_activation_enable(struct cmd_context *cmd);
+int event_activation_is_on(struct cmd_context *cmd);
 
 #endif
diff --git a/tools/vgchange.c b/tools/vgchange.c
index 985907a02..518e13551 100644
--- a/tools/vgchange.c
+++ b/tools/vgchange.c
@@ -194,6 +194,41 @@ int vgchange_background_polling(struct cmd_context *cmd, struct volume_group *vg
 	return 1;
 }
 
+static int _online_pvid_file_create_all(struct cmd_context *cmd)
+{
+	struct lvmcache_info *info;
+	struct dev_iter *iter;
+	struct device *dev;
+	const char *vgname;
+	int exists;
+	int exist_count = 0;
+	int create_count = 0;
+
+	if (!(iter = dev_iter_create(NULL, 0)))
+		return 0;
+	while ((dev = dev_iter_get(cmd, iter))) {
+		if (dev->pvid[0] &&
+		    (info = lvmcache_info_from_pvid(dev->pvid, dev, 0))) {
+			vgname = lvmcache_vgname_from_info(info);
+			if (vgname && !is_orphan_vg(vgname)) {
+				/*
+				 * Ignore exsting pvid file because a pvscan may be creating
+				 * the same file as the same time we are, which is expected.
+				 */
+				exists = 0;
+				online_pvid_file_create(cmd, dev, vgname, 1, &exists);
+				if (exists)
+					exist_count++;
+				else
+					create_count++;
+			}
+		}
+	}
+	dev_iter_destroy(iter);
+	log_debug("PV online files created %d exist %d", create_count, exist_count);
+	return 1;
+}
+
 int vgchange_activate(struct cmd_context *cmd, struct volume_group *vg,
 		      activation_change_t activate)
 {
@@ -219,6 +254,11 @@ int vgchange_activate(struct cmd_context *cmd, struct volume_group *vg,
 		return 1;
 	}
 
+	if (arg_is_set(cmd, vgonline_ARG) && !online_vg_file_create(cmd, vg->name)) {
+		log_print("VG %s already online", vg->name);
+		return 1;
+	}
+
 	/*
 	 * Safe, since we never write out new metadata here. Required for
 	 * partial activation to work.
@@ -262,11 +302,6 @@ int vgchange_activate(struct cmd_context *cmd, struct volume_group *vg,
 		}
 	}
 
-	if (arg_is_set(cmd, vgonline_ARG) && !online_vg_file_create(cmd, vg->name)) {
-		log_print("VG %s finished", vg->name);
-		return 1;
-	}
-
 	if (!_activate_lvs_in_vg(cmd, vg, activate)) {
 		stack;
 		r = 0;
@@ -733,6 +768,7 @@ static int _vgchange_single(struct cmd_context *cmd, const char *vg_name,
 int vgchange(struct cmd_context *cmd, int argc, char **argv)
 {
 	struct processing_handle *handle;
+	const char *ea;
 	uint32_t flags = 0;
 	int ret;
 
@@ -845,6 +881,89 @@ int vgchange(struct cmd_context *cmd, int argc, char **argv)
 			cmd->lockd_vg_enforce_sh = 1;
 	}
 
+	if ((ea = arg_str_value(cmd, eventactivation_ARG, NULL))) {
+		int service_only = 0, event_only = 0, service_to_event = 0;
+		int ea_service = 0, ea_event = 0, ea_on = 0;
+		int on_file_exists;
+		int event_activation;
+
+		if (!get_event_activation_config_settings(cmd, &service_only, &event_only, &service_to_event))
+			return ECMD_FAILED;
+		if (!get_event_activation_command_options(cmd, ea, &ea_service, &ea_event, &ea_on))
+			return ECMD_FAILED;
+		event_activation = find_config_tree_bool(cmd, global_event_activation_CFG, NULL);
+
+		/*
+		 * The combination of lvm.conf event_activation/event_activation_options
+		 * and the --eventactivation service|event value determines if this
+		 * command should do anything or be skipped, along with the existence of
+		 * the /run/lvm/event-activation-on file in case of service_to_event.
+		 */
+		if (!event_activation) {
+			if (ea_event) {
+				log_print("Skip vgchange for event and event_activation=0.");
+				return ECMD_PROCESSED;
+			}
+		} else {
+			if (event_only && ea_service) {
+				log_print("Skip vgchange for service and event_activation_options event_only.");
+				return ECMD_PROCESSED;
+			}
+			if (service_only && ea_event) {
+				log_print("Skip vgchange for event and event_activation_options service_only.");
+				return ECMD_PROCESSED;
+			}
+
+			on_file_exists = event_activation_is_on(cmd);
+
+			if (service_to_event && ea_service && on_file_exists) {
+				log_print("Skip vgchange for service and event-activation-on.");
+				return ECMD_PROCESSED;
+			}
+			if (service_to_event && ea_event && !on_file_exists) {
+				log_print("Skip vgchange for event and no event-activation-on.");
+				return ECMD_PROCESSED;
+			}
+		}
+
+		/*
+		 * Switch from service activation to event activation when:
+		 * lvm.conf event_activation=1,
+		 * event_activation_options=service_to_event,
+		 * and --eventactivation service,on.
+		 *
+		 * When enabling event-based activation, first create the
+		 * /run/lvm/event-activation-on file to tell other commands
+		 * to begin responding to PV events and doing activation
+		 * for newly completed VGs.  It also needs to create online
+		 * files for existing PVs because some VGs may be incomplete
+		 * at this point, and future pvscan commands need to
+		 * find online files for PVs that have already appeared.
+		 * The label scan provides info to know which PVs are
+		 * present and should have pvid online files created.
+		 *
+		 * process_each_vg() usually begins with lock_global() and
+		 * lvmcache_label_scan(), and then processes each VG.
+		 * In this case, lock_global/lvmcache_label_scan are done
+		 * before calling process_each_vg. This allows a special
+		 * step to be inserted between the label scan and processing
+		 * vgs. That step creates the pvid online files, which
+		 * requires label scan info.  The lock_global and
+		 * lvmcache_label_scan will be skipped by process_each_vg
+		 * since they are already done here.
+		 */
+		if (event_activation && service_to_event && ea_service && ea_on) {
+			if (!event_activation_enable(cmd))
+				log_warn("WARNING: Failed to create event-activation-on.");
+
+			if (!lock_global(cmd, "sh"))
+				return ECMD_FAILED;
+			lvmcache_label_scan(cmd);
+			_online_pvid_file_create_all(cmd);
+			flags |= PROCESS_SKIP_SCAN;
+		}
+	}
+
 	if (update)
 		flags |= READ_FOR_UPDATE;
 	else if (arg_is_set(cmd, activate_ARG))
diff --git a/udev/69-dm-lvm-metad.rules.in b/udev/69-dm-lvm-metad.rules.in
index 78f506520..3e2424d06 100644
--- a/udev/69-dm-lvm-metad.rules.in
+++ b/udev/69-dm-lvm-metad.rules.in
@@ -121,6 +121,6 @@ LABEL="direct_pvscan"
 #  MD    |          |      X      |       X*       |                   |
 #  loop  |          |      X      |       X*       |                   |
 #  other |    X     |             |       X        |                   |   X
-RUN+="(LVM_EXEC)/lvm pvscan --background --cache --activate ay --major $major --minor $minor", ENV{LVM_SCANNED}="1"
+RUN+="(LVM_EXEC)/lvm pvscan --cache -aay --eventactivation event --major $major --minor $minor", ENV{LVM_SCANNED}="1"
 
 LABEL="lvm_end"
diff --git a/udev/69-dm-lvm.rules.in b/udev/69-dm-lvm.rules.in
index 39e5b9807..025b62e7b 100644
--- a/udev/69-dm-lvm.rules.in
+++ b/udev/69-dm-lvm.rules.in
@@ -78,9 +78,19 @@ ENV{SYSTEMD_READY}="1"
 #
 # TODO: adjust the output of vgchange -aay so that
 # it's better suited to appearing in the journal.
+#
+# "--eventactivation event" used with pvscan or vgchange
+# tells the command that it is being run from an event.
+# The command does nothing if lvm.conf event_activation=0.
+# The command does nothing if lvm.conf event_activation=1,
+# and lvm.conf event_activation_options="service_only".
+# The command goes ahead if event_activation_options="event_only",
+# or if event_activation_options="service_to_event" and the
+# event-activation-on file exists.
+#
 
-IMPORT{program}="(LVM_EXEC)/lvm pvscan --cache --listvg --checkcomplete --vgonline --udevoutput --journal=output $env{DEVNAME}"
-ENV{LVM_VG_NAME_COMPLETE}=="?*", RUN+="/usr/bin/systemd-run -r --no-block --property DefaultDependencies=no --unit lvm-activate-$env{LVM_VG_NAME_COMPLETE} lvm vgchange -aay --nohints $env{LVM_VG_NAME_COMPLETE}"
+IMPORT{program}="(LVM_EXEC)/lvm pvscan --cache --listvg --checkcomplete --vgonline --eventactivation event --udevoutput --journal=output $env{DEVNAME}"
+ENV{LVM_VG_NAME_COMPLETE}=="?*", RUN+="/usr/bin/systemd-run -r --no-block --property DefaultDependencies=no --unit lvm-activate-$env{LVM_VG_NAME_COMPLETE} lvm vgchange -aay --nohints --eventactivation event $env{LVM_VG_NAME_COMPLETE}"
 GOTO="lvm_end"
 
 LABEL="lvm_end"