activate: add autoactivation hooks

Define an 'activation_handler' that gets called automatically on
PV appearance/disappearance while processing the lvmetad_pv_found
and lvmetad_pv_gone functions that are supposed to update the
lvmetad state based on PV availability state. For now, the actual
support is for PV appearance only, leaving room for PV disappearance
support as well (which is a more complex problem to solve as this
needs to count with possible device stack).

Add a new activation change mode - CHANGE_AAY exposed as
'--activate ay/-aay' argument ('activate automatically').

Factor out the vgchange activation functionality for use in other
tools (like pvscan...).

1 files changed, 14 insertions, 17 deletions

diff --git a/tools/vgchange.c b/tools/vgchange.c
index fdad81f1..29562a58 100644
--- a/tools/vgchange.c
+++ b/tools/vgchange.c
@@ -81,8 +81,8 @@ static int _poll_lvs_in_vg(struct cmd_context *cmd,
 	return count;
 }
 
-static int _activate_lvs_in_vg(struct cmd_context *cmd,
-			       struct volume_group *vg, int activate)
+static int _activate_lvs_in_vg(struct cmd_context *cmd, struct volume_group *vg,
+			       activation_change_t activate)
 {
 	struct lv_list *lvl;
 	struct logical_volume *lv;
@@ -211,35 +211,32 @@ static int _vgchange_background_polling(struct cmd_context *cmd, struct volume_g
 	return 1;
 }
 
-static int _vgchange_activate(struct cmd_context *cmd, struct volume_group *vg)
+int vgchange_activate(struct cmd_context *cmd, struct volume_group *vg,
+		      activation_change_t activate)
 {
-	int lv_open, active, monitored = 0;
-	int activate_arg, r = 1;
-	int activate = 1;
+	int lv_open, active, monitored = 0, r = 1, do_activate = 1;
+
+	if ((activate == CHANGE_AN) || (activate == CHANGE_ALN))
+		do_activate = 0;
 
 	/*
 	 * Safe, since we never write out new metadata here. Required for
 	 * partial activation to work.
 	 */
-	cmd->handles_missing_pvs = 1;
-
-	activate_arg = arg_uint_value(cmd, activate_ARG, 0);
-
-	if ((activate_arg == CHANGE_AN) || (activate_arg == CHANGE_ALN))
-		activate = 0;
+        cmd->handles_missing_pvs = 1;
 
 	/* FIXME: Force argument to deactivate them? */
-	if (!activate && (lv_open = lvs_in_vg_opened(vg))) {
+	if (!do_activate && (lv_open = lvs_in_vg_opened(vg))) {
 		log_error("Can't deactivate volume group \"%s\" with %d open "
 			  "logical volume(s)", vg->name, lv_open);
 		return 0;
 	}
 
 	/* FIXME Move into library where clvmd can use it */
-	if (activate)
+	if (do_activate)
 		check_current_backup(vg);
 
-	if (activate && (active = lvs_in_vg_activated(vg))) {
+	if (do_activate && (active = lvs_in_vg_activated(vg))) {
 		log_verbose("%d logical volume(s) in volume group \"%s\" "
 			    "already active", active, vg->name);
 		if (dmeventd_monitor_mode() != DMEVENTD_MONITOR_IGNORE) {
@@ -252,7 +249,7 @@ static int _vgchange_activate(struct cmd_context *cmd, struct volume_group *vg)
 		}
 	}
 
-	if (!_activate_lvs_in_vg(cmd, vg, activate_arg))
+	if (!_activate_lvs_in_vg(cmd, vg, activate))
 		r = 0;
 
 	/* Print message only if there was not found a missing VG */
@@ -509,7 +506,7 @@ static int vgchange_single(struct cmd_context *cmd, const char *vg_name,
 	}
 
 	if (arg_count(cmd, activate_ARG)) {
-		if (!_vgchange_activate(cmd, vg))
+		if (!vgchange_activate(cmd, vg, arg_uint_value(cmd, activate_ARG, CHANGE_AY)))
 			return ECMD_FAILED;
 	}