new udev and systemd autoactivation

udev rule calls pvscan directly which indicates if the
VG can be activated.  If so, the lvm-vgchange service
is run, which runs vgchange -aay.

lib/commands/toolcontext.c

@@ -320,6 +320,33 @@ static int _parse_debug_classes(struct cmd_context *cmd)
 	return debug_classes;
 }
 
+static uint32_t _parse_log_journal(struct cmd_context *cmd, int cfg, const char *cfgname)
+{
+	const struct dm_config_node *cn;
+	const struct dm_config_value *cv;
+	uint32_t fields = 0;
+	uint32_t val;
+
+	if (!(cn = find_config_tree_array(cmd, cfg, NULL))) {
+		log_debug("Unable to find configuration for log/%s.", cfgname);
+		return 0;
+	}
+
+	for (cv = cn->v; cv; cv = cv->next) {
+		if (cv->type != DM_CFG_STRING) {
+			log_verbose("log/%s contains a value which is not a string.  Ignoring.", cfgname);
+			continue;
+		}
+
+		if ((val = log_journal_str_to_val(cv->v.str)))
+			fields |= val;
+		else
+			log_verbose("Unrecognised value for log/%s: %s", cfgname, cv->v.str);
+	}
+
+	return fields;
+}
+
 static void _init_logging(struct cmd_context *cmd)
 {
 	int append = 1;
@@ -388,6 +415,9 @@ static void _init_logging(struct cmd_context *cmd)
 	init_debug_file_fields(_parse_debug_fields(cmd, log_debug_file_fields_CFG, "debug_file_fields"));
 	init_debug_output_fields(_parse_debug_fields(cmd, log_debug_output_fields_CFG, "debug_output_fields"));
 
+	cmd->default_settings.journal = _parse_log_journal(cmd, log_journal_CFG, "journal");
+	init_log_journal(cmd->default_settings.journal);
+
 	t = time(NULL);
 	ctime_r(&t, &timebuf[0]);
 	timebuf[24] = '\0';

lib/commands/toolcontext.h

@@ -29,6 +29,7 @@ struct config_info {
 	int debug_classes;
 	int verbose;
 	int silent;
+	int suppress;
 	int test;
 	int syslog;
 	int activation;
@@ -40,6 +41,7 @@ struct config_info {
 	int udev_sync;
 	int udev_fallback;
 	int issue_discards;
+	uint32_t journal;
 	const char *msg_prefix;
 	const char *fmt_name;
 	const char *dmeventd_executable;

lib/config/config_settings.h

@@ -876,6 +876,12 @@ cfg(log_syslog_CFG, "syslog", log_CFG_SECTION, 0, CFG_TYPE_BOOL, DEFAULT_SYSLOG,
 cfg(log_file_CFG, "file", log_CFG_SECTION, CFG_DEFAULT_UNDEFINED, CFG_TYPE_STRING, NULL, vsn(1, 0, 0), NULL, 0, NULL,
 	"Write error and debug log messages to a file specified here.\n")
 
+cfg_array(log_journal_CFG, "journal", log_CFG_SECTION, CFG_ALLOW_EMPTY | CFG_DEFAULT_COMMENTED, CFG_TYPE_STRING, NULL, vsn(2, 3, 12), NULL, 0, NULL,
+	  "Record lvm information in the systemd journal.\n"
+	  "command: record commands that are run.\n"
+	  "output: record default output from commands.\n"
+	  "debug: record debug messages from commands.\n")
+
 cfg(log_overwrite_CFG, "overwrite", log_CFG_SECTION, 0, CFG_TYPE_BOOL, DEFAULT_OVERWRITE, vsn(1, 0, 0), NULL, 0, NULL,
 	"Overwrite the log file each time the program is run.\n")
 

lib/log/log.c

@@ -25,6 +25,7 @@
 #include <syslog.h>
 #include <ctype.h>
 #include <time.h>
+#include <systemd/sd-journal.h>
 
 static FILE *_log_file;
 static char _log_file_path[PATH_MAX];
@@ -40,6 +41,7 @@ static char _msg_prefix[30] = "  ";
 static int _abort_on_internal_errors_config = 0;
 static uint32_t _debug_file_fields;
 static uint32_t _debug_output_fields;
+static uint32_t _log_journal = 0;
 
 static lvm2_log_fn_t _lvm2_log_fn = NULL;
 
@@ -455,6 +457,11 @@ void init_debug_output_fields(uint32_t debug_fields)
 	_debug_output_fields = debug_fields;
 }
 
+void init_log_journal(uint32_t fields)
+{
+	_log_journal = fields;
+}
+
 static void _set_time_prefix(char *prefix, int buflen)
 {
 
@@ -609,6 +616,33 @@ static void _vprint_log(int level, const char *file, int line, int dm_errno_or_c
 	}
 
       log_it:
+
+	if (_log_journal) {
+		int to_journal = 0;
+
+		/* By default the visible command output is _LOG_WARN or less. */
+
+		if (_log_journal & LOG_JOURNAL_DEBUG)
+			to_journal = 1;
+		if ((_log_journal & LOG_JOURNAL_OUTPUT) && (log_level(level) <= _LOG_WARN))
+			to_journal = 1;
+
+		if (to_journal) {
+			int prio;
+			switch (log_level(level)) {
+			case _LOG_ERR:    prio = LOG_ERR; break;
+			case _LOG_WARN:   prio = LOG_WARNING; break;
+			case _LOG_INFO:   prio = LOG_INFO; break;
+			case _LOG_NOTICE: prio = LOG_NOTICE; break;
+			case _LOG_DEBUG:  prio = LOG_DEBUG; break;
+			default:          prio = LOG_INFO;
+			}
+			va_copy(ap, orig_ap);
+			sd_journal_printv(prio, trformat, ap);
+			va_end(ap);
+		}
+	}
+
 	if (!logged_via_report && ((verbose_level() >= level) && !_log_suppress)) {
 		if (verbose_level() > _LOG_DEBUG) {
 			memset(buf, 0, sizeof(buf));
@@ -792,3 +826,60 @@ void log_set_report_object_name_and_id(const char *name, const char *id)
 	_log_report.object_name = name;
 	_log_report.object_id = id;
 }
+
+/*
+ * TODO: log/journal=["daemon_command"]
+ *       daemon_command: record commands that are run by an lvm daemon.
+ *       (i.e. not commands run directly by a user.)
+ *       For this we need to be able to clearly identify when a command is
+ *       being run by dmeventd/lvmpolld/lvmdbusd.
+ *
+ * TODO: log/journal_commmand_names=["lvcreate","lvconvert"]
+ * This would restrict log/journal=["command"] to the listed command names.
+ * Also allow "!command" to exclude a command, e.g. ["!pvs"]
+ *
+ * TODO: log/journal_daemon_command_names=["lvcreate","lvconvert"]
+ * This would restrict log/journal=["dameon_command"] to the listed command names.
+ *
+ * TODO: log/journal_daemon_names=["dmeventd"]
+ * This would restrict log/journal=["daemon_command"] to commands run by
+ * the named daemon.
+ *
+ * TODO: log/command_to_file=<path> would write this info to the file.
+ *
+ * TODO: log/debug_to_file=<path> would write full debugging to the file.
+ *       (the same effect as log/file=<path> log/level=7)
+ */
+
+void log_command(const char *cmd_line, const char *cmd_name, const char *cmd_id)
+{
+	if (_log_journal & LOG_JOURNAL_COMMAND) {
+
+		/*
+		 * TODO: DAEMON=dmeventd|lvmpolld|lvmdbusd,
+		 * Could we include caller info such as libblkid, udev rule, etc?
+		 * Does systemd already record the caller for us?
+		 */
+
+		/* The command line, pid, and other things are automatically included. */
+
+		sd_journal_send("MESSAGE=lvm command %s", cmd_name,
+				"MESSAGE_ID=3ca432788c374e4ba684b834188eca36",
+				"LVM_CMD_NAME=%s", cmd_name,
+				"LVM_CMD_ID=%s", cmd_id,
+				"PRIORITY=%i", LOG_INFO,
+				NULL);
+	}
+}
+
+uint32_t log_journal_str_to_val(const char *str)
+{
+	if (!strcasecmp(str, "command"))
+		return LOG_JOURNAL_COMMAND;
+	if (!strcasecmp(str, "output"))
+		return LOG_JOURNAL_OUTPUT;
+	if (!strcasecmp(str, "debug"))
+		return LOG_JOURNAL_DEBUG;
+	return 0;
+}
+

lib/log/log.h

@@ -63,6 +63,10 @@
 #define LOG_DEBUG_FIELD_FILELINE	0x0004
 #define LOG_DEBUG_FIELD_MESSAGE		0x0008
 
+#define LOG_JOURNAL_COMMAND             0x0001
+#define LOG_JOURNAL_OUTPUT              0x0002
+#define LOG_JOURNAL_DEBUG               0x0004
+
 
 /*
  * Classes available for debug log messages.

lib/log/lvm-logging.h

@@ -62,6 +62,12 @@ void reset_log_duplicated(void);
 void init_syslog(int facility);
 void fin_syslog(void);
 
+void init_log_journal(uint32_t fields);
+uint32_t log_journal_str_to_val(const char *str);
+
+void log_command(const char *cmd_line, const char *cmd_name, const char *cmd_id);
+
+
 int error_message_produced(void);
 void reset_lvm_errno(int store_errmsg);
 int stored_errno(void);

lib/metadata/metadata.c

@@ -5264,3 +5264,36 @@ struct volume_group *vg_read_for_update(struct cmd_context *cmd, const char *vg_
 
 	return vg;
 }
+
+int get_visible_lvs_using_pv(struct cmd_context *cmd, struct volume_group *vg, struct device *dev,
+			     struct dm_list *lvs_list)
+{
+	struct pv_list *pvl;
+	struct lv_list *lvl, *lvl2;
+	struct physical_volume *pv = NULL;
+
+	dm_list_iterate_items(pvl, &vg->pvs) {
+		if (pvl->pv->dev == dev) {
+			pv = pvl->pv;
+			break;
+		}
+	}
+
+	if (!pv)
+		return_0;
+
+	dm_list_iterate_items(lvl, &vg->lvs) {
+		if (!lv_is_visible(lvl->lv))
+			continue;
+		if (!lv_is_on_pv(lvl->lv, pv))
+			continue;
+
+		if (!(lvl2 = dm_pool_zalloc(cmd->mem, sizeof(*lvl2))))
+			return_0;
+		lvl2->lv = lvl->lv;
+		dm_list_add(lvs_list, &lvl2->list);
+	}
+
+	return 1;
+}
+

lib/metadata/metadata.h

@@ -539,4 +539,8 @@ char *tags_format_and_copy(struct dm_pool *mem, const struct dm_list *tagsl);
 
 void set_pv_devices(struct format_instance *fid, struct volume_group *vg);
 
+int get_visible_lvs_using_pv(struct cmd_context *cmd, struct volume_group *vg, struct device *dev,
+                            struct dm_list *lvs_list);
+
+
 #endif

scripts/lvm-vgchange.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=LVM event activation of VG %i
+Documentation=man:vgchange(8)
+DefaultDependencies=no
+StartLimitIntervalSec=0
+Before=shutdown.target
+Conflicts=shutdown.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=no
+ExecStart=@SBINDIR@/lvm vgchange -aay %i

tools/args.h

@@ -307,12 +307,33 @@ arg(ignoreunsupported_ARG, '\0', "ignoreunsupported", 0, 0, 0,
 arg(importdevices_ARG, '\0', "importdevices", 0, 0, 0,
     "Add devices to the devices file.\n")
 
+arg(journal_ARG, '\0', "journal", string_VAL, 0, 0,
+    "Record information in the systemd journal.\n"
+    "This information is in addition to information\n"
+    "enabled by the lvm.conf log/journal setting.\n"
+    "command: record information about the command.\n"
+    "output: record the default command output.\n"
+    "debug: record full command debugging.\n")
+
 arg(labelsector_ARG, '\0', "labelsector", number_VAL, 0, 0,
     "By default the PV is labelled with an LVM2 identifier in its second\n"
     "sector (sector 1). This lets you use a different sector near the\n"
     "start of the disk (between 0 and 3 inclusive - see LABEL_SCAN_SECTORS\n"
     "in the source). Use with care.\n")
 
+arg(listlvs_ARG, '\0', "listlvs", 0, 0, 0,
+    "Print a list of LVs that use the device.\n")
+
+arg(listvg_ARG, '\0', "listvg", 0, 0, 0,
+    "Print the VG that uses the device.\n")
+
+arg(checkcomplete_ARG, '\0', "checkcomplete", 0, 0, 0,
+    "Check if all the devices used by a VG or LV are present,\n"
+    "and print \"complete\" or \"incomplete\" for each listed\n"
+    "VG or LV.  This option is used as a part of event-based\n"
+    "autoactivation, so pvscan will do nothing if this option\n"
+    "is set and event_activation=0 in the config settings.\n")
+
 arg(lockopt_ARG, '\0', "lockopt", string_VAL, 0, 0,
     "Used to pass options for special cases to lvmlockd.\n"
     "See \\fBlvmlockd\\fP(8) for more information.\n")
@@ -795,6 +816,9 @@ arg(type_ARG, '\0', "type", segtype_VAL, 0, 0,
     "(e.g. --stripes, --mirrors, --snapshot, --virtualsize, --thin, --cache, --vdo).\n"
     "Use inferred types with care because it can lead to unexpected results.\n")
 
+arg(udevoutput_ARG, '\0', "udevoutput", 0, 0, 0,
+    "Command output is modified to be imported from a udev rule.\n")
+
 arg(unbuffered_ARG, '\0', "unbuffered", 0, 0, 0,
     "Produce output immediately without sorting or aligning the columns properly.\n")
 
@@ -871,6 +895,10 @@ arg(vgmetadatacopies_ARG, '\0', "vgmetadatacopies", vgmetadatacopies_VAL, 0, 0,
     "\\fBall\\fP causes LVM to first clear the metadataignore flags on\n"
     "all PVs, and then to become unmanaged.\n")
 
+arg(vgonline_ARG, '\0', "vgonline", 0, 0, 0,
+    "The first command to see a complete VG will report it uniquely.\n"
+    "Other commands to see the complete VG will report it differently.\n")
+
 arg(withsummary_ARG, '\0', "withsummary", 0, 0, 0,
     "Display a one line comment for each configuration node.\n")
 

tools/command-lines.in

@@ -188,7 +188,7 @@
 #
 OO_ALL: --commandprofile String, --config String, --debug,
 --driverloaded Bool, --help, --nolocking, --lockopt String, --longhelp, --profile String, --quiet,
---verbose, --version, --yes, --test, --devicesfile String, --devices PV
+--verbose, --version, --yes, --test, --devicesfile String, --devices PV, --journal String
 
 #
 # options for pvs, lvs, vgs, fullreport
@@ -1603,11 +1603,37 @@ DESC: Display PV information.
 
 pvscan --cache_long
 OO: --ignorelockingfailure, --reportformat ReportFmt,
---activate ay, --major Number, --minor Number, --noudevsync
+--major Number, --minor Number, --noudevsync
 OP: PV|String ...
 IO: --background
 ID: pvscan_cache
-DESC: Autoactivate a VG when all PVs are online.
+DESC: Record that a PV is online or offline.
+
+pvscan --cache_long --activate ay
+OO: --ignorelockingfailure, --reportformat ReportFmt,
+--major Number, --minor Number, --noudevsync
+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
+ID: pvscan_cache
+DESC: Record that a PV is online and list the VG using the PV.
+
+pvscan --cache_long --listlvs PV
+OO: --ignorelockingfailure, --checkcomplete, --vgonline
+ID: pvscan_cache
+DESC: Record that a PV is online and list LVs using the PV.
+
+pvscan --listlvs PV
+ID: pvscan_cache
+DESC: List LVs using the PV.
+
+pvscan --listvg PV
+ID: pvscan_cache
+DESC: List the VG using the PV.
 
 ---
 

tools/lvmcmdline.c

@@ -2007,6 +2007,8 @@ out:
 	log_debug("Recognised command %s (id %d / enum %d).",
 		  commands[best_i].command_id, best_i, commands[best_i].command_enum);
 
+	log_command(cmd->cmd_line, commands[best_i].name, commands[best_i].command_id);
+
 	return &commands[best_i];
 }
 
@@ -2381,6 +2383,9 @@ static void _reset_current_settings_to_default(struct cmd_context *cmd)
 
 static void _get_current_output_settings_from_args(struct cmd_context *cmd)
 {
+	if (arg_is_set(cmd, udevoutput_ARG))
+		cmd->current_settings.suppress = 1;
+
 	if (arg_is_set(cmd, debug_ARG))
 		cmd->current_settings.debug = _LOG_FATAL + (arg_count(cmd, debug_ARG) - 1);
 
@@ -2392,14 +2397,25 @@ static void _get_current_output_settings_from_args(struct cmd_context *cmd)
 		cmd->current_settings.verbose = 0;
 		cmd->current_settings.silent = (arg_count(cmd, quiet_ARG) > 1) ? 1 : 0;
 	}
+
+	/*
+	 * default_settings.journal is already set from config and has already been
+	 * applied using init_log_journal().
+	 * current_settings have been set to default_settings.
+	 * now --journal value adds to current_settings.
+	 */
+	if (arg_is_set(cmd, journal_ARG))
+		cmd->current_settings.journal |= log_journal_str_to_val(arg_str_value(cmd, journal_ARG, ""));
 }
 
 static void _apply_current_output_settings(struct cmd_context *cmd)
 {
+	log_suppress(cmd->current_settings.suppress);
 	init_debug(cmd->current_settings.debug);
 	init_debug_classes_logged(cmd->default_settings.debug_classes);
 	init_verbose(cmd->current_settings.verbose + VERBOSE_BASE_LEVEL);
 	init_silent(cmd->current_settings.silent);
+	init_log_journal(cmd->current_settings.journal);
 }
 
 static int _read_devices_list(struct cmd_context *cmd)

tools/pvscan.c

@@ -179,6 +179,27 @@ out:
 	return ret;
 }
 
+/*
+ * 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)
+ */
+#define log_print_pvscan(cmd, fmt, args...) \
+do \
+	if (arg_is_set(cmd, udevoutput_ARG)) \
+		log_print(fmt, ##args); \
+	else \
+		log_print("pvscan[%d] " fmt, getpid(), ##args); \
+while (0)
+
+#define log_error_pvscan(cmd, fmt, args...) \
+do \
+	if (arg_is_set(cmd, udevoutput_ARG)) \
+		log_error(fmt, ##args); \
+	else \
+		log_error("pvscan[%d] " fmt, getpid(), ##args); \
+while (0)
+
 static char *_vgname_in_pvid_file_buf(char *buf)
 {
 	char *p, *n;
@@ -259,7 +280,7 @@ static void _lookup_file_remove(char *vgname)
  * that the vg will be activated again when it becomes complete.
  */
 
-static void _online_vg_file_remove(const char *vgname)
+void online_vg_file_remove(const char *vgname)
 {
 	char path[PATH_MAX];
 
@@ -314,7 +335,7 @@ static void _online_pvid_file_remove_devno(int major, int minor)
 				log_sys_debug("unlink", path);
 
 			if (file_vgname[0]) {
-				_online_vg_file_remove(file_vgname);
+				online_vg_file_remove(file_vgname);
 				_lookup_file_remove(file_vgname);
 			}
 		}
@@ -345,7 +366,7 @@ static void _online_files_remove(const char *dirpath)
 		log_sys_debug("closedir", dirpath);
 }
 
-static int _online_pvid_file_create(struct device *dev, const char *vgname)
+static int _online_pvid_file_create(struct cmd_context *cmd, struct device *dev, const char *vgname)
 {
 	char path[PATH_MAX];
 	char buf[MAX_PVID_FILE_SIZE] = { 0 };
@@ -362,18 +383,18 @@ static int _online_pvid_file_create(struct device *dev, const char *vgname)
 	minor = (int)MINOR(dev->dev);
 
 	if (dm_snprintf(path, sizeof(path), "%s/%s", _pvs_online_dir, dev->pvid) < 0) {
-		log_error("Path %s/%s is too long.", _pvs_online_dir, dev->pvid);
+		log_error_pvscan(cmd, "Path %s/%s is too long.", _pvs_online_dir, dev->pvid);
 		return 0;
 	}
 
 	if ((len1 = dm_snprintf(buf, sizeof(buf), "%d:%d\n", major, minor)) < 0) {
-		log_error("Cannot create online file path for %s %d:%d.", dev_name(dev), major, minor);
+		log_error_pvscan(cmd, "Cannot create online file path for %s %d:%d.", dev_name(dev), major, minor);
 		return 0;
 	}
 
 	if (vgname) {
 		if ((len2 = dm_snprintf(buf + len1, sizeof(buf) - len1, "vg:%s\n", vgname)) < 0) {
-			log_warn("Incomplete online file for %s %d:%d vg %s.", dev_name(dev), major, minor, vgname);
+			log_print_pvscan(cmd, "Incomplete online file for %s %d:%d vg %s.", dev_name(dev), major, minor, vgname);
 			/* can still continue without vgname */
 			len2 = 0;
 		}
@@ -387,7 +408,7 @@ static int _online_pvid_file_create(struct device *dev, const char *vgname)
 	if (fd < 0) {
 		if (errno == EEXIST)
 			goto check_duplicate;
-		log_error("Failed to create online file for %s path %s error %d", dev_name(dev), path, errno);
+		log_error_pvscan(cmd, "Failed to create online file for %s path %s error %d", dev_name(dev), path, errno);
 		return 0;
 	}
 
@@ -435,12 +456,12 @@ check_duplicate:
 	/* Don't know how vgname might not match, but it's not good so fail. */
 
 	if ((file_major != major) || (file_minor != minor))
-		log_error("pvscan[%d] PV %s is duplicate for PVID %s on %d:%d and %d:%d.",
-			  getpid(), dev_name(dev), dev->pvid, major, minor, file_major, file_minor);
+		log_error_pvscan(cmd, "PV %s is duplicate for PVID %s on %d:%d and %d:%d.",
+			         dev_name(dev), dev->pvid, major, minor, file_major, file_minor);
 
 	if (file_vgname[0] && vgname && strcmp(file_vgname, vgname))
-		log_error("pvscan[%d] PV %s has unexpected VG %s vs %s.",
-			  getpid(), dev_name(dev), vgname, file_vgname);
+		log_error_pvscan(cmd, "PV %s has unexpected VG %s vs %s.",
+			         dev_name(dev), vgname, file_vgname);
 
 	return 0;
 }
@@ -475,7 +496,7 @@ static int _write_lookup_file(struct cmd_context *cmd, struct volume_group *vg)
 	int fd;
 
 	if (dm_snprintf(path, sizeof(path), "%s/%s", _pvs_lookup_dir, vg->name) < 0) {
-		log_error("Path %s/%s is too long.", _pvs_lookup_dir, vg->name);
+		log_error_pvscan(cmd, "Path %s/%s is too long.", _pvs_lookup_dir, vg->name);
 		return 0;
 	}
 
@@ -638,7 +659,7 @@ static int _count_pvid_files_from_lookup_file(struct cmd_context *cmd, struct de
 	return (vgname) ? 1 : 0;
 }
 
-static void _online_dir_setup(void)
+static void _online_dir_setup(struct cmd_context *cmd)
 {
 	struct stat st;
 	int rv;
@@ -652,7 +673,7 @@ static void _online_dir_setup(void)
 	dm_prepare_selinux_context(NULL, 0);
 
 	if ((rv < 0) && stat(DEFAULT_RUN_DIR, &st))
-		log_error("Failed to create %s %d", DEFAULT_RUN_DIR, errno);
+		log_error_pvscan(cmd, "Failed to create %s %d", DEFAULT_RUN_DIR, errno);
 
 do_pvs:
 	if (!stat(_pvs_online_dir, &st))
@@ -664,7 +685,7 @@ do_pvs:
 	dm_prepare_selinux_context(NULL, 0);
 
 	if ((rv < 0) && stat(_pvs_online_dir, &st))
-		log_error("Failed to create %s %d", _pvs_online_dir, errno);
+		log_error_pvscan(cmd, "Failed to create %s %d", _pvs_online_dir, errno);
 
 do_vgs:
 	if (!stat(_vgs_online_dir, &st))
@@ -676,7 +697,7 @@ do_vgs:
 	dm_prepare_selinux_context(NULL, 0);
 
 	if ((rv < 0) && stat(_vgs_online_dir, &st))
-		log_error("Failed to create %s %d", _vgs_online_dir, errno);
+		log_error_pvscan(cmd, "Failed to create %s %d", _vgs_online_dir, errno);
 
 do_lookup:
 	if (!stat(_pvs_lookup_dir, &st))
@@ -688,7 +709,7 @@ do_lookup:
 	dm_prepare_selinux_context(NULL, 0);
 
 	if ((rv < 0) && stat(_pvs_lookup_dir, &st))
-		log_error("Failed to create %s %d", _pvs_lookup_dir, errno);
+		log_error_pvscan(cmd, "Failed to create %s %d", _pvs_lookup_dir, errno);
 
 
 }
@@ -725,7 +746,7 @@ static int _pvscan_aa_single(struct cmd_context *cmd, const char *vg_name,
 	log_debug("pvscan autoactivating VG %s.", vg_name);
 
 	if (!vgchange_activate(cmd, vg, CHANGE_AAY)) {
-		log_error("%s: autoactivation failed.", vg->name);
+		log_error_pvscan(cmd, "%s: autoactivation failed.", vg->name);
 		pp->activate_errors++;
 	}
 
@@ -738,7 +759,7 @@ static int _online_vg_file_create(struct cmd_context *cmd, const char *vgname)
 	int fd;
 
 	if (dm_snprintf(path, sizeof(path), "%s/%s", _vgs_online_dir, vgname) < 0) {
-		log_error("Path %s/%s is too long.", _vgs_online_dir, vgname);
+		log_error_pvscan(cmd, "Path %s/%s is too long.", _vgs_online_dir, vgname);
 		return 0;
 	}
 
@@ -826,15 +847,15 @@ static int _get_devs_from_saved_vg(struct cmd_context *cmd, const char *vgname,
 		_online_pvid_file_read(path, &file_major, &file_minor, file_vgname);
 
 		if (file_vgname[0] && strcmp(vgname, file_vgname)) {
-			log_error("Wrong VG found for %d:%d PVID %s: %s vs %s",
-				  file_major, file_minor, pvid, vgname, file_vgname);
+			log_error_pvscan(cmd, "Wrong VG found for %d:%d PVID %s: %s vs %s",
+				         file_major, file_minor, pvid, vgname, file_vgname);
 			goto bad;
 		}
 
 		devno = MKDEV(file_major, file_minor);
 
 		if (!(dev = dev_cache_get_by_devt(cmd, devno, NULL, NULL))) {
-			log_error("No device found for %d:%d PVID %s", file_major, file_minor, pvid);
+			log_error_pvscan(cmd, "No device found for %d:%d PVID %s", file_major, file_minor, pvid);
 			goto bad;
 		}
 
@@ -844,7 +865,7 @@ static int _get_devs_from_saved_vg(struct cmd_context *cmd, const char *vgname,
 		if (strcmp(name1, name2)) {
 			if (!id_write_format((const struct id *)pvid, uuidstr, sizeof(uuidstr)))
 				uuidstr[0] = '\0';
-			log_print("PVID %s read from %s last written to %s.", uuidstr, name1, name2);
+			log_print_pvscan(cmd, "PVID %s read from %s last written to %s.", uuidstr, name1, name2);
 			goto bad;
 		}
 
@@ -921,7 +942,7 @@ static int _pvscan_aa_quick(struct cmd_context *cmd, struct pvscan_aa_params *pp
 	 * The dev_cache gives us struct devices from the devnums.
 	 */
 	if (!_get_devs_from_saved_vg(cmd, vgname, &devs)) {
-		log_print("pvscan[%d] VG %s not using quick activation.", getpid(), vgname);
+		log_print_pvscan(cmd, "VG %s not using quick activation.", vgname);
 		*no_quick = 1;
 		return ECMD_FAILED;
 	}
@@ -932,7 +953,7 @@ static int _pvscan_aa_quick(struct cmd_context *cmd, struct pvscan_aa_params *pp
 	 * label rescan are then disabled in vg_read.)
 	 */
 	if (!lock_vol(cmd, vgname, LCK_VG_WRITE, NULL)) {
-		log_error("pvscan activation for VG %s failed to lock VG.", vgname);
+		log_error_pvscan(cmd, "activation for VG %s failed to lock VG.", vgname);
 		return ECMD_FAILED;
 	}
 
@@ -945,7 +966,7 @@ static int _pvscan_aa_quick(struct cmd_context *cmd, struct pvscan_aa_params *pp
 	label_scan_devs(cmd, NULL, &devs);
 
 	if (!(vgid = lvmcache_vgid_from_vgname(cmd, vgname))) {
-		log_error("pvscan activation for VG %s failed to find vgid.", vgname);
+		log_error_pvscan(cmd, "activation for VG %s failed to find vgid.", vgname);
 		return ECMD_FAILED;
 	}
 
@@ -965,7 +986,7 @@ static int _pvscan_aa_quick(struct cmd_context *cmd, struct pvscan_aa_params *pp
 		 * original device arg scan.  There will be very few and unusual
 		 * cases that would be caught here.
 		 */
-		log_error("pvscan activation for VG %s cannot read (%x).", vgname, error_flags);
+		log_error_pvscan(cmd, "activation for VG %s cannot read (%x).", vgname, error_flags);
 		return ECMD_FAILED;
 	}
 
@@ -987,7 +1008,7 @@ static int _pvscan_aa_quick(struct cmd_context *cmd, struct pvscan_aa_params *pp
 	dm_list_iterate_items(pvl, &vg->pvs) {
 		if (dev_in_device_list(pvl->pv->dev, &devs))
 			continue;
-		log_error("pvscan activation for VG %s found different devices.", vgname);
+		log_error_pvscan(cmd, "activation for VG %s found different devices.", vgname);
 		ret = ECMD_FAILED;
 		goto out;
 	}
@@ -995,7 +1016,7 @@ static int _pvscan_aa_quick(struct cmd_context *cmd, struct pvscan_aa_params *pp
 	log_debug("pvscan autoactivating VG %s.", vgname);
 
 	if (!vgchange_activate(cmd, vg, CHANGE_AAY)) {
-		log_error("%s: autoactivation failed.", vg->name);
+		log_error_pvscan(cmd, "%s: autoactivation failed.", vg->name);
 		pp->activate_errors++;
 	}
 
@@ -1014,7 +1035,7 @@ static int _pvscan_aa(struct cmd_context *cmd, struct pvscan_aa_params *pp,
 	int ret = ECMD_FAILED;
 
 	if (!(handle = init_processing_handle(cmd, NULL))) {
-		log_error("Failed to initialize processing handle.");
+		log_error_pvscan(cmd, "Failed to initialize processing handle.");
 		goto out;
 	}
 
@@ -1029,11 +1050,11 @@ static int _pvscan_aa(struct cmd_context *cmd, struct pvscan_aa_params *pp,
 	 */
 	dm_list_iterate_items_safe(sl, sl2, vgnames) {
 		if (!_online_vg_file_create(cmd, sl->str)) {
-			log_print("pvscan[%d] VG %s skip autoactivation.", getpid(), sl->str);
+			log_print_pvscan(cmd, "VG %s skip autoactivation.", sl->str);
 			str_list_del(vgnames, sl->str);
 			continue;
 		}
-		log_print("pvscan[%d] VG %s run autoactivation.", getpid(), sl->str);
+		log_print_pvscan(cmd, "VG %s run autoactivation.", sl->str);
 	}
 
 	if (dm_list_empty(vgnames)) {
@@ -1165,6 +1186,64 @@ static int _get_args_devs(struct cmd_context *cmd, struct dm_list *pvscan_args,
 	return 1;
 }
 
+static void _set_pv_devices_online(struct cmd_context *cmd, struct volume_group *vg)
+{
+	char path[PATH_MAX];
+	char file_vgname[NAME_LEN];
+	char pvid[ID_LEN+1] = { 0 };
+	struct pv_list *pvl;
+	struct device *dev;
+	int major, minor;
+	dev_t devno;
+
+	dm_list_iterate_items(pvl, &vg->pvs) {
+		memcpy(&pvid, &pvl->pv->id.uuid, ID_LEN);
+
+		if (pvl->pv->status & MISSING_PV) {
+			log_debug("set_pv_devices_online vg %s pv %s missing flag already set",
+				  vg->name, pvid);
+			continue;
+		}
+
+		if (!_online_pvid_file_exists(pvid)) {
+			log_debug("set_pv_devices_online vg %s pv %s no online file",
+				  vg->name, pvid);
+			pvl->pv->status |= MISSING_PV;
+			continue;
+		}
+
+		memset(path, 0, sizeof(path));
+		snprintf(path, sizeof(path), "%s/%s", _pvs_online_dir, pvid);
+
+		major = 0;
+		minor = 0;
+		file_vgname[0] = '\0';
+
+		_online_pvid_file_read(path, &major, &minor, file_vgname);
+
+		if (file_vgname[0] && strcmp(vg->name, file_vgname)) {
+			log_warn("WARNING: VG %s PV %s wrong vgname in online file %s",
+				  vg->name, pvid, file_vgname);
+			pvl->pv->status |= MISSING_PV;
+			continue;
+		}
+
+		devno = MKDEV(major, minor);
+
+		if (!(dev = dev_cache_get_by_devt(cmd, devno, NULL, NULL))) {
+			log_print_pvscan(cmd, "VG %s PV %s no device found for %d:%d",
+					 vg->name, pvid, major, minor);
+			pvl->pv->status |= MISSING_PV;
+			continue;
+		}
+
+		log_debug("set_pv_devices_online vg %s pv %s is online %s",
+			  vg->name, pvid, dev_name(dev));
+
+		pvl->pv->dev = dev;
+	}
+}
+
 static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvscan_devs,
 			int *pv_count, struct dm_list *complete_vgnames)
 {
@@ -1177,15 +1256,20 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 	struct metadata_area *mda1, *mda2;
 	struct volume_group *vg;
 	struct physical_volume *pv;
-	const char *vgname;
-	uint32_t ext_version, ext_flags;
+	const char *vgname = NULL;
 	uint64_t devsize;
+	uint32_t ext_version, ext_flags;
+	int do_cache = arg_is_set(cmd, cache_long_ARG);
 	int do_activate = arg_is_set(cmd, activate_ARG);
-	int do_full_check;
+	int do_list_lvs = arg_is_set(cmd, listlvs_ARG);
+	int do_list_vg = arg_is_set(cmd, listvg_ARG);
+	int do_check_complete = arg_is_set(cmd, checkcomplete_ARG);
+	int do_vgonline = arg_is_set(cmd, vgonline_ARG);
 	int pvs_online;
 	int pvs_offline;
 	int pvs_unknown;
 	int vg_complete;
+	int do_full_check;
 	int ret = 1;
 
 	dm_list_iterate_items_safe(devl, devl2, pvscan_devs) {
@@ -1199,20 +1283,20 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 		 * using udev and the native version didn't catch it.
 		 */
 		if (udev_dev_is_mpath_component(dev)) {
-			log_print("pvscan[%d] ignore multipath component %s.", getpid(), dev_name(dev));
+			log_print_pvscan(cmd, "ignore multipath component %s.", dev_name(dev));
 			continue;
 		}
 
 		if (!(info = lvmcache_info_from_pvid(dev->pvid, dev, 0))) {
 			if (!do_all)
-				log_print("pvscan[%d] ignore %s with no lvm info.", getpid(), dev_name(dev));
+				log_print_pvscan(cmd, "ignore %s with no lvm info.", dev_name(dev));
 			continue;
 		}
 
 		ext_version = lvmcache_ext_version(info);
 		ext_flags = lvmcache_ext_flags(info);
 		if ((ext_version >= 2) && !(ext_flags & PV_EXT_USED)) {
-			log_print("pvscan[%d] PV %s not used.", getpid(), dev_name(dev));
+			log_print_pvscan(cmd, "PV %s not used.", dev_name(dev));
 			(*pv_count)++;
 			continue;
 		}
@@ -1231,7 +1315,7 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 			vg = mda2->ops->vg_read(cmd, fid, "", mda2, NULL, NULL);
 
 		if (!vg) {
-			log_print("pvscan[%d] PV %s has no VG metadata.", getpid(), dev_name(dev));
+			log_print_pvscan(cmd, "PV %s has no VG metadata.", dev_name(dev));
 			fmt->ops->destroy_instance(fid);
 			goto online;
 		}
@@ -1239,7 +1323,7 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 		set_pv_devices(fid, vg);
 
 		if (!(pv = find_pv(vg, dev))) {
-			log_print("pvscan[%d] PV %s not found in VG %s.", getpid(), dev_name(dev), vg->name);
+			log_print_pvscan(cmd, "PV %s not found in VG %s.", dev_name(dev), vg->name);
 			release_vg(vg);
 			continue;
 		}
@@ -1257,13 +1341,13 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 				do_full_check = 1;
 		}
 		if (do_full_check && dev_is_md_component(dev, NULL, 1)) {
-			log_print("pvscan[%d] ignore md component %s.", getpid(), dev_name(dev));
+			log_print_pvscan(cmd, "ignore md component %s.", dev_name(dev));
 			release_vg(vg);
 			continue;
 		}
 
 		if (vg_is_shared(vg)) {
-			log_print("pvscan[%d] PV %s ignore shared VG.", getpid(), dev_name(dev));
+			log_print_pvscan(cmd, "PV %s ignore shared VG.", dev_name(dev));
 			release_vg(vg);
 			continue;
 		}
@@ -1273,7 +1357,13 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 		    vg_is_foreign(vg)) {
 			log_verbose("Ignore PV %s with VG system id %s with our system id %s",
 				    dev_name(dev), vg->system_id, cmd->system_id);
-			log_print("pvscan[%d] PV %s ignore foreign VG.", getpid(), dev_name(dev));
+			log_print_pvscan(cmd, "PV %s ignore foreign VG.", dev_name(dev));
+			release_vg(vg);
+			continue;
+		}
+
+		if (vg_is_exported(vg)) {
+			log_print_pvscan(cmd, "PV %s ignore exported VG.", dev_name(dev));
 			release_vg(vg);
 			continue;
 		}
@@ -1292,19 +1382,20 @@ 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 (!_online_pvid_file_create(dev, vg ? vg->name : NULL)) {
-			log_error("pvscan[%d] PV %s failed to create online file.", getpid(), dev_name(dev));
+		if (do_cache && !_online_pvid_file_create(cmd, dev, vg ? vg->name : NULL)) {
+			log_error_pvscan(cmd, "PV %s failed to create online file.", dev_name(dev));
 			release_vg(vg);
 			ret = 0;
 			continue;
 		}
 
 		/*
-		 * When not activating we don't need to know about vg completeness.
+		 * A plain pvscan --cache <dev> just creates the online file.
 		 */
-		if (!do_activate) {
-			log_print("pvscan[%d] PV %s online.", getpid(), dev_name(dev));
+		if (!do_activate && !do_list_lvs && !do_list_vg) {
+			log_print_pvscan(cmd, "PV %s online.", dev_name(dev));
 			release_vg(vg);
 			continue;
 		}
@@ -1312,58 +1403,159 @@ static int _online_devs(struct cmd_context *cmd, int do_all, struct dm_list *pvs
 		/*
 		 * Check if all the PVs for this VG are online.  If the arrival
 		 * of this dev completes the VG, then save the vgname in
-		 * complete_vgnames so it will be activated.
+		 * complete_vgnames (activation phase will want to know which
+		 * VGs to activate.)
 		 */
-		pvs_online = 0;
-		pvs_offline = 0;
-		pvs_unknown = 0;
-		vg_complete = 0;
+		if (do_activate || do_check_complete) {
+			pvs_online = 0;
+			pvs_offline = 0;
+			pvs_unknown = 0;
+			vg_complete = 0;
 
-		if (vg) {
-			/*
-			 * Use the VG metadata from this PV for a list of all
-			 * PVIDs.  Write a lookup file of PVIDs in case another
-			 * pvscan needs it.  After writing lookup file, recheck
-			 * pvid files to resolve a possible race with another
-			 * pvscan reading the lookup file that missed it.
-			 */
-			log_debug("checking all pvid files from vg %s", vg->name);
-			_count_pvid_files(vg, &pvs_online, &pvs_offline);
-
-			if (pvs_offline && _write_lookup_file(cmd, vg)) {
-				log_debug("rechecking all pvid files from vg %s", vg->name);
+			if (vg) {
+				/*
+				 * Use the VG metadata from this PV for a list of all
+				 * PVIDs.  Write a lookup file of PVIDs in case another
+				 * pvscan needs it.  After writing lookup file, recheck
+				 * pvid files to resolve a possible race with another
+				 * pvscan reading the lookup file that missed it.
+				 */
+				log_debug("checking all pvid files from vg %s", vg->name);
 				_count_pvid_files(vg, &pvs_online, &pvs_offline);
-				if (!pvs_offline)
-					log_print("pvscan[%d] VG %s complete after recheck.", getpid(), vg->name);
+	
+				if (pvs_offline && _write_lookup_file(cmd, vg)) {
+					log_debug("rechecking all pvid files from vg %s", vg->name);
+					_count_pvid_files(vg, &pvs_online, &pvs_offline);
+					if (!pvs_offline)
+						log_print_pvscan(cmd, "VG %s complete after recheck.", vg->name);
+				}
+	
+				vgname = vg->name;
+			} else {
+				/*
+				 * No VG metadata on this PV, so try to use a lookup
+				 * file written by a prior pvscan for a list of all
+				 * PVIDs.  A lookup file may not exist for this PV if
+				 * it's the first to appear from the VG.
+				 */
+				log_debug("checking all pvid files from lookup file");
+				if (!_count_pvid_files_from_lookup_file(cmd, dev, &pvs_online, &pvs_offline, &vgname))
+					pvs_unknown = 1;
+			}
+	
+			if (pvs_unknown) {
+				log_print_pvscan(cmd, "PV %s online, VG unknown.", dev_name(dev));
+				vg_complete = 0;
+	
+			} else if (pvs_offline) {
+				log_print_pvscan(cmd, "PV %s online, VG %s incomplete (need %d).",
+						 dev_name(dev), vgname, pvs_offline);
+				vg_complete = 0;
+	
+			} else {
+				log_print_pvscan(cmd, "PV %s online, VG %s is complete.", dev_name(dev), vgname);
+				if (!str_list_add(cmd->mem, complete_vgnames, dm_pool_strdup(cmd->mem, vgname)))
+					stack;
+				vg_complete = 1;
+			}
+		}
+
+		if (!vgname && vg)
+			vgname = vg->name;
+
+		if (do_list_vg || do_list_lvs) {
+			if (!vgname) {
+				log_print("VG unknown");
+			} else if (!do_check_complete) {
+				log_print("VG %s", vgname);
+			} else if (vg_complete) {
+				if (do_vgonline && !_online_vg_file_create(cmd, vgname)) {
+					log_print("VG %s finished", vgname);
+				} else {
+					/*
+					 * A udev rule imports KEY=val from a program's stdout.
+					 * Other output causes udev to ignore everything.
+					 * Run pvscan from udev rule using --udevoutput to
+					 * enable this printf, and suppress all log output
+					 */
+					if (arg_is_set(cmd, udevoutput_ARG))
+						printf("LVM_VG_NAME_COMPLETE='%s'\n", vgname);
+					else
+						log_print("VG %s complete", vgname);
+				}
+			} else {
+				if (arg_is_set(cmd, udevoutput_ARG))
+					printf("LVM_VG_NAME_INCOMPLETE='%s'\n", vgname);
+				else
+					log_print("VG %s incomplete", vgname);
 			}
 
-			vgname = vg->name;
-		} else {
 			/*
-			 * No VG metadata on this PV, so try to use a lookup
-			 * file written by a prior pvscan for a list of all
-			 * PVIDs.  A lookup file may not exist for this PV if
-			 * it's the first to appear from the VG.
+			 * When the VG is complete|finished, we could print
+			 * a list of devices in the VG, by reading the pvid files
+			 * that were counted, which provides major:minor of each
+			 * device and using that to get the struct dev and dev_name.
+			 * The user could pass this list of devices to --devices
+			 * to optimize a subsequent command (activation) on the VG.
+			 * Just call set_pv_devices_online (if not done othewise)
+			 * since that finds the devs.
 			 */
-			log_debug("checking all pvid files from lookup file");
-			if (!_count_pvid_files_from_lookup_file(cmd, dev, &pvs_online, &pvs_offline, &vgname))
-				pvs_unknown = 1;
 		}
 
-		if (pvs_unknown) {
-			log_print("pvscan[%d] PV %s online, VG unknown.",
-				  getpid(), dev_name(dev));
-		} else if (pvs_offline) {
-			log_print("pvscan[%d] PV %s online, VG %s incomplete (need %d).",
-				  getpid(), dev_name(dev), vgname, pvs_offline);
-		} else {
-			log_print("pvscan[%d] PV %s online, VG %s is complete.", getpid(), dev_name(dev), vgname);
-			if (!str_list_add(cmd->mem, complete_vgnames, dm_pool_strdup(cmd->mem, vgname)))
-				stack;
-			vg_complete = 1;
+		if (do_list_lvs && !vg) {
+			/* require all PVs used for booting have metadata */
+			log_print_pvscan(cmd, "Cannot list LVs from device without metadata.");
 		}
 
-		if (!saved_vg && vg && vg_complete && !do_all && (dm_list_size(pvscan_devs) == 1))
+		if (do_list_lvs && vg) {
+			struct dm_list lvs_list;
+			struct lv_list *lvl;
+
+			dm_list_init(&lvs_list);
+
+			/*
+			 * For each vg->pvs entry, get the dev based on the online file
+			 * for the pvid and set pv->dev or pv->status MISSING_PV.
+			 */
+			_set_pv_devices_online(cmd, vg);
+
+			/*
+			 * lvs_list are LVs that use dev.
+			 */
+			if (!get_visible_lvs_using_pv(cmd, vg, dev, &lvs_list))
+				log_print_pvscan(cmd, "Failed to find LVs using %s.", dev_name(dev));
+
+			if (!do_check_complete) {
+				dm_list_iterate_items(lvl, &lvs_list)
+					log_print("LV %s", display_lvname(lvl->lv));
+			} else if (vg_complete) {
+				/*
+				 * A shortcut; the vg complete implies all lvs are complete.
+				 */
+				dm_list_iterate_items(lvl, &lvs_list)
+					log_print("LV %s complete", display_lvname(lvl->lv));
+			} else {
+				/*
+				 * For each LV in VG, check if all devs are present.
+				 * Sets the PARTIAL flag on LVs that are not complete.
+				 */
+				if (!vg_mark_partial_lvs(vg, 1))
+					log_print_pvscan(cmd, "Failed to check partial lvs.");
+
+				dm_list_iterate_items(lvl, &lvs_list) {
+					if (!lv_is_partial(lvl->lv))
+						log_print("LV %s complete", display_lvname(lvl->lv));
+					else
+						log_print("LV %s incomplete", display_lvname(lvl->lv));
+				}
+			}
+		}
+
+		/*
+		 * When "pvscan --cache -aay <dev>" completes the vg, save the
+		 * struct vg to use for quick activation function.
+		 */
+		if (do_activate && !saved_vg && vg && vg_complete && !do_all && (dm_list_size(pvscan_devs) == 1))
 			saved_vg = vg;
 		else
 			release_vg(vg);
@@ -1452,7 +1644,7 @@ static int _pvscan_cache_args(struct cmd_context *cmd, int argc, char **argv,
 	cmd->pvscan_cache_single = 1;
 
 	if (!setup_devices(cmd)) {
-		log_error("Failed to set up devices.");
+		log_error_pvscan(cmd, "Failed to set up devices.");
 		return 0;
 	}
 
@@ -1518,8 +1710,8 @@ static int _pvscan_cache_args(struct cmd_context *cmd, int argc, char **argv,
 
 	dm_list_iterate_items_safe(devl, devl2, &pvscan_devs) {
 		if (!cmd->filter->passes_filter(cmd, cmd->filter, devl->dev, NULL)) {
-			log_print("pvscan[%d] %s excluded by filters: %s.", getpid(),
-				  dev_name(devl->dev), dev_filtered_reason(devl->dev));
+			log_print_pvscan(cmd, "%s excluded by filters: %s.",
+					 dev_name(devl->dev), dev_filtered_reason(devl->dev));
 			dm_list_del(&devl->list);
 		}
 	}
@@ -1547,7 +1739,7 @@ static int _pvscan_cache_args(struct cmd_context *cmd, int argc, char **argv,
 	dm_list_iterate_items_safe(devl, devl2, &pvscan_devs) {
 		if (!label_read_pvid(devl->dev)) {
 			/* Not an lvm device */
-			log_print("pvscan[%d] %s not an lvm device.", getpid(), dev_name(devl->dev));
+			log_print_pvscan(cmd, "%s not an lvm device.", dev_name(devl->dev));
 			dm_list_del(&devl->list);
 			continue;
 		}
@@ -1558,8 +1750,8 @@ static int _pvscan_cache_args(struct cmd_context *cmd, int argc, char **argv,
 		 */
 		if (relax_deviceid_filter) {
 			if (!get_du_for_pvid(cmd, devl->dev->pvid)) {
-				log_print("pvscan[%d] %s excluded by devices file (checking PVID).",
-					  getpid(), dev_name(devl->dev));
+				log_print_pvscan(cmd, "%s excluded by devices file (checking PVID).",
+					         dev_name(devl->dev));
 				dm_list_del(&devl->list);
 				continue;
 			}
@@ -1567,8 +1759,8 @@ static int _pvscan_cache_args(struct cmd_context *cmd, int argc, char **argv,
 
 		/* Applies all filters, including those that need data from dev. */
 		if (!cmd->filter->passes_filter(cmd, cmd->filter, devl->dev, NULL)) {
-			log_print("pvscan[%d] %s excluded by filters: %s.", getpid(),
-				  dev_name(devl->dev), dev_filtered_reason(devl->dev));
+			log_print_pvscan(cmd, "%s excluded by filters: %s.",
+					 dev_name(devl->dev), dev_filtered_reason(devl->dev));
 			dm_list_del(&devl->list);
 		}
 	}
@@ -1624,6 +1816,29 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
 		return ECMD_PROCESSED;
 	}
 
+	/*
+	 * lvm udev rules call:
+	 *   pvscan --cache --listvg|--listlvs --checkcomplete PV
+	 * when PVs appear, even if event_activation=0 in lvm.conf.
+	 *
+	 * The udev rules will do autoactivation if they see complete
+	 * VGs/LVs reported from the pvscan.
+	 *
+	 * When event_activation=0 we do not want to do autoactivation
+	 * from udev events, so we need the pvscan to not report any
+	 * complete VGs/LVs when event_activation=0 so that the udev
+	 * rules do not attempt to autoactivate.
+	 */
+
+	if (arg_is_set(cmd, checkcomplete_ARG) &&
+	    !find_config_tree_bool(cmd, global_event_activation_CFG, NULL)) {
+		if (arg_is_set(cmd, udevoutput_ARG))
+			printf("LVM_EVENT_ACTIVATION=0\n");
+		else
+			log_print_pvscan(cmd, "Ignoring pvscan with --checkcomplete because event_activation is disabled.");
+		return ECMD_PROCESSED;
+	}
+
 	if (arg_is_set(cmd, major_ARG) + arg_is_set(cmd, minor_ARG))
 		devno_args = 1;
 
@@ -1634,7 +1849,7 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
 
 	do_all = !argc && !devno_args;
 
-	_online_dir_setup();
+	_online_dir_setup(cmd);
 
 	if (do_all) {
 		if (!_pvscan_cache_all(cmd, argc, argv, &complete_vgnames))

tools/toollib.c

@@ -810,6 +810,24 @@ int lv_change_activate(struct cmd_context *cmd, struct logical_volume *lv,
 		lv_clear_integrity_recalculate_metadata(lv);
 	}
 
+	/*
+	 * When LVs are deactivated, then autoactivation of the VG is
+	 * "re-armed" by removing the vg online file.  So, after deactivation
+	 * of LVs, if PVs are disconnected and reconnected again, event
+	 * activation will trigger autoactivation again.  This secondary
+	 * autoactivation is somewhat different from, and not as important as
+	 * the initial autoactivation during system startup.  The secondary
+	 * autoactivation will happen to a VG on a running system and may be
+	 * mixing with user commands, so the end result is unpredictable.
+	 *
+	 * It's possible that we might want a config setting for usersto  
+	 * disable secondary autoactivations.  Once a system is up, the
+	 * user may want to take charge of activation changes to the VG
+	 * and not have the system autoactivation interfere.
+	 */
+	if (!is_change_activating(activate) && find_config_tree_bool(cmd, global_event_activation_CFG, NULL))
+		online_vg_file_remove(lv->vg->name);
+
 	set_lv_notify(lv->vg->cmd);
 
 	return r;

tools/tools.h

@@ -291,4 +291,6 @@ int lvconvert_cachevol_attach_single(struct cmd_context *cmd,
                                      struct logical_volume *lv,
                                      struct processing_handle *handle);
 
+void online_vg_file_remove(const char *vgname);
+
 #endif

udev/69-dm-lvm.rules

@@ -0,0 +1,77 @@
+# Copyright (C) 2012,2021 Red Hat, Inc. All rights reserved.
+#
+# This file is part of LVM2.
+
+# Udev rules for LVM.
+#
+# This rule requires blkid to be called on block devices before so only devices
+# used as LVM PVs are processed (ID_FS_TYPE="LVM2_member").
+
+SUBSYSTEM!="block", GOTO="lvm_end"
+
+ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}=="1", GOTO="lvm_end"
+
+# Only process devices already marked as a PV - this requires blkid to be called before.
+ENV{ID_FS_TYPE}!="LVM2_member", GOTO="lvm_end"
+ENV{DM_MULTIPATH_DEVICE_PATH}=="1", GOTO="lvm_end"
+ACTION=="remove", GOTO="lvm_end"
+
+# Create /dev/disk/by-id/lvm-pv-uuid-<PV_UUID> symlink for each PV
+ENV{ID_FS_UUID_ENC}=="?*", SYMLINK+="disk/by-id/lvm-pv-uuid-$env{ID_FS_UUID_ENC}"
+
+# If the PV is a special device listed below, scan only if the device is
+# properly activated. These devices are not usable after an ADD event,
+# but they require an extra setup and they are ready after a CHANGE event.
+# Also support coldplugging with ADD event but only if the device is already
+# properly activated.
+# This logic should be eventually moved to rules where those particular
+# devices are processed primarily (MD and loop).
+
+# DM device:
+KERNEL!="dm-[0-9]*", GOTO="next"
+ENV{DM_UDEV_PRIMARY_SOURCE_FLAG}=="1", ENV{DM_ACTIVATION}=="1", GOTO="lvm_scan"
+GOTO="lvm_end"
+
+# MD device:
+LABEL="next"
+KERNEL!="md[0-9]*", GOTO="next"
+IMPORT{db}="LVM_MD_PV_ACTIVATED"
+ACTION=="add", ENV{LVM_MD_PV_ACTIVATED}=="1", GOTO="lvm_scan"
+ACTION=="change", ENV{LVM_MD_PV_ACTIVATED}!="1", TEST=="md/array_state", ENV{LVM_MD_PV_ACTIVATED}="1", GOTO="lvm_scan"
+ACTION=="add", KERNEL=="md[0-9]*p[0-9]*", GOTO="lvm_scan"
+ENV{LVM_MD_PV_ACTIVATED}!="1", ENV{SYSTEMD_READY}="0"
+GOTO="lvm_end"
+
+# Loop device:
+LABEL="next"
+KERNEL!="loop[0-9]*", GOTO="next"
+ACTION=="add", ENV{LVM_LOOP_PV_ACTIVATED}=="1", GOTO="lvm_scan"
+ACTION=="change", ENV{LVM_LOOP_PV_ACTIVATED}!="1", TEST=="loop/backing_file", ENV{LVM_LOOP_PV_ACTIVATED}="1", GOTO="lvm_scan"
+ENV{LVM_LOOP_PV_ACTIVATED}!="1", ENV{SYSTEMD_READY}="0"
+GOTO="lvm_end"
+
+LABEL="next"
+ACTION!="add", GOTO="lvm_end"
+
+LABEL="lvm_scan"
+
+ENV{SYSTEMD_READY}="1"
+
+# pvscan will check if this device completes a VG,
+# i.e. all PVs in the VG are now present with the
+# arrival of this PV.  If so, it prints to stdout:
+# LVM_VG_NAME_COMPLETE='foo'
+#
+# When the VG is complete it can be activated, so
+# the lvm-vgchange service is started which runs
+# vgchange -aay <vgname>.
+#
+# pvscan only reads the single device specified,
+# and uses temp files under /run/lvm to check if
+# other PVs in the VG are present.
+
+IMPORT{program}="/usr/sbin/lvm pvscan --cache --listvg --checkcomplete --vgonline --udevoutput --journal=output $env{DEVNAME}"
+ENV{LVM_VG_NAME_COMPLETE}=="?*", RUN+="/usr/bin/systemctl start lvm-vgchange@$env{LVM_VG_NAME_COMPLETE}.service"
+GOTO="lvm_end"
+
+LABEL="lvm_end"