vgchange: add --activate ay option (autoactivate)

Normally, the 'vgchange -ay' activates all volume groups (that pass
the activation/volume_list filter if set).

This call can appear in two scenarios:
 - system boot (so activation within a script in general)
 - manual call on command line (so activaton on user's direct request)

For the former one, we would like to select which VGs should be actually
activated. One can define the list of VGs directly to do that. But that
would require the same list to be provided in all the scripts.

The 'vgchange -aay' will check for the activation/auto_activation_volume_list
in adition and it will activate only those VGs/LVs that pass this
filter (assuming all to be activated if the list is not defined - the
same logic we already have for activation/volume_list).

Init/boot scripts should use this form of activation primarily
(which, anyway, becomes only a fallback now with autoactivation done
on PV appearance in tandem with lvmetad in place).

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.97 - 
 ===============================
+  Add --activate ay to vgchange.
   Add support for volume autoactivation using lvmetad.
   Add --activate synonym for --available arg and prefer --activate.
   Never issue discards when LV extents are being reconfigured, not deleted.

tools/commands.h

@@ -742,7 +742,7 @@ xx(vgchange,
    "\t[-u|--uuid] " "\n"
    "\t[-v|--verbose] " "\n"
    "\t[--version]" "\n"
-   "\t{-a|--activate [e|l]{y|n}  |" "\n"
+   "\t{-a|--activate [a|e|l]{y|n}  |" "\n"
    "\t -c|--clustered {y|n} |" "\n"
    "\t -x|--resizeable {y|n} |" "\n"
    "\t -l|--logicalvolume MaxLogicalVolumes |" "\n"

tools/vgchange.c

@@ -131,6 +131,12 @@ static int _activate_lvs_in_vg(struct cmd_context *cmd, struct volume_group *vg,
 			continue;
 		}
 
+		if (activate == CHANGE_AAY) {
+			if (!lv_passes_auto_activation_filter(cmd, lv))
+				continue;
+			activate = CHANGE_ALY;
+		}
+
 		expected_count++;
 
 		if (activate == CHANGE_AN) {