add lvm-on-luks partition to crypttab (#398)

Before this change, this code didn't detect that an ext4 partition on
LVM-on-LUKS needed a crypttab entry.

Author: beerriot

src/Core/Main.vala

@@ -3012,11 +3012,19 @@ public class Main : GLib.Object{
 		// check and add entries for mapped devices which are encrypted
 
 		foreach(var mnt in mount_list){
-			if ((mnt.device != null) && (mnt.device.parent != null) && (mnt.device.is_on_encrypted_partition())){
-				
+			if ((mnt.device != null) && (mnt.device.parent != null)
+				&& ((mnt.device.is_on_encrypted_partition())
+					|| ((mnt.device.parent.parent != null) &&
+						(mnt.device.parent.is_on_encrypted_partition())))){
+
+				// We could be either directly on LUKS or on LVM-on-LUKS,
+				// so be sure to get the top-level LUKS UUID.
+				var crypt_parent = (mnt.device.is_on_encrypted_partition()) ?
+					mnt.device.parent.uuid : mnt.device.parent.parent.uuid;
+
 				// find existing
 				var entry = CryptTabEntry.find_entry_by_uuid(
-					crypttab_list, mnt.device.parent.uuid);
+					crypttab_list, crypt_parent);
 
 				// add if missing
 				if (entry == null){
@@ -3025,8 +3033,8 @@ public class Main : GLib.Object{
 				}
 
 				// set custom values
-				entry.device_uuid = mnt.device.parent.uuid;
-				entry.mapped_name = "luks-%s".printf(mnt.device.parent.uuid);
+				entry.device_uuid = crypt_parent;
+				entry.mapped_name = "luks-%s".printf(crypt_parent);
 				entry.keyfile = "none";
 				entry.options = "luks,nofail";
 			}