Add Read-Only Btrfs Snapshots Option (issue #332)

files/timeshift.json

@@ -3,6 +3,7 @@
   "parent_device_uuid" : "",
   "do_first_run" : "true",
   "btrfs_mode" : "false",
+  "btrfs_readonly" : "true",
   "include_btrfs_home" : "false",
   "stop_cron_emails" : "true",
   "schedule_monthly" : "false",

src/AppConsole.vala

@@ -160,6 +160,10 @@ public class AppConsole : GLib.Object {
 					App.app_mode = "ondemand";
 					break;
 
+				case "--readonly":
+					App.btrfs_readonly = bool.parse(args[++k]);
+					break;
+
 				case "--comment":
 				case "--comments":
 					App.cmd_comments = args[++k];
@@ -368,6 +372,7 @@ public class AppConsole : GLib.Object {
 		msg += "  --check                    " + _("Create snapshot if scheduled") + "\n";
 		msg += "  --create                   " + _("Create snapshot (even if not scheduled)") + "\n";
 		msg += "  --comments <string>        " + _("Set snapshot description") + "\n";
+		msg += "  --readonly <bool>          " + _("Create read-only snapshots (BTRFS only) (default: config)") + "\n";
 		msg += "  --tags {O,B,H,D,W,M}       " + _("Add tags to snapshot (default: O)") + "\n";;
 		msg += "\n";
 		msg += _("Restore") + ":\n";

src/Core/Main.vala

@@ -50,6 +50,7 @@ public class Main : GLib.Object{
 	public string backup_parent_uuid = "";
 
 	public bool btrfs_mode = true;
+	public bool btrfs_readonly = true;
 	public bool include_btrfs_home_for_backup = false;
 	public bool include_btrfs_home_for_restore = false;
 
@@ -1654,7 +1655,7 @@ public class Main : GLib.Object{
 				dst_path = dst_path.replace("/@home/@home", "/@home");
 			}
 
-			string cmd = "btrfs subvolume snapshot '%s' '%s' \n".printf(src_path, dst_path);
+			string cmd = "btrfs subvolume snapshot %s '%s' '%s' \n".printf(btrfs_readonly ? "-r" : "", src_path, dst_path);
 
 			if (LOG_COMMANDS) { log_debug(cmd); }
 
@@ -1683,7 +1684,7 @@ public class Main : GLib.Object{
 		// write control file
 		var snapshot = Snapshot.write_control_file(
 			snapshot_path, dt_created, sys_uuid, current_distro.full_name(),
-			initial_tags, cmd_comments, 0, true, false, repo);
+			initial_tags, btrfs_readonly ? "ReadOnly" : cmd_comments, 0, true, false, repo);
 
 		// write subvolume info
 		foreach(var subvol in sys_subvolumes.values){
@@ -3207,6 +3208,7 @@ public class Main : GLib.Object{
 
 		config.set_string_member("do_first_run", false.to_string());
 		config.set_string_member("btrfs_mode", btrfs_mode.to_string());
+		config.set_string_member("btrfs_readonly", btrfs_readonly.to_string());
 		config.set_string_member("include_btrfs_home_for_backup", include_btrfs_home_for_backup.to_string());
 		config.set_string_member("include_btrfs_home_for_restore", include_btrfs_home_for_restore.to_string());
 		config.set_string_member("stop_cron_emails", stop_cron_emails.to_string());
@@ -3304,6 +3306,8 @@ public class Main : GLib.Object{
 		bool do_first_run = json_get_bool(config, "do_first_run", false); // false as default
 
 		btrfs_mode = json_get_bool(config, "btrfs_mode", false); // false as default
+
+		btrfs_readonly = json_get_bool(config, "btrfs_readonly", true); // true as default
 
 		if (do_first_run){
 			set_first_run_flag();

src/Gtk/SnapshotBackendBox.vala

@@ -36,6 +36,7 @@ class SnapshotBackendBox : Gtk.Box{
 
 	private Gtk.RadioButton opt_rsync;
 	private Gtk.RadioButton opt_btrfs;
+	private Gtk.CheckButton opt_btrfs_readonly;
 	private Gtk.Label lbl_description;
 	private Gtk.Window parent_window;
 
@@ -103,15 +104,34 @@ class SnapshotBackendBox : Gtk.Box{
         }
 
 		opt_btrfs.toggled.connect(()=>{
+			add_opt_btrfs_ro(hbox);
 			if (opt_btrfs.active){
 				App.btrfs_mode = true;
 				init_backend();
 				type_changed();
 				update_description();
 			}
+			this.show_all();
 		});
 	}
 
+	private void add_opt_btrfs_ro(Gtk.Box hbox){
+		if (opt_btrfs.active){
+				var opt = new Gtk.CheckButton.with_label(_("Create Read-only snapshots by default"));
+				hbox.add(opt);
+				opt_btrfs_readonly = opt;
+
+				opt_btrfs_readonly.toggled.connect(()=>{
+					App.btrfs_readonly = opt_btrfs_readonly.active;
+				});
+		} else {
+			if (opt_btrfs_readonly != null){
+				hbox.remove(opt_btrfs_readonly);
+				opt_btrfs_readonly = null;
+			}
+		}
+	}
+
 	private bool check_for_btrfs_tools() {
         try {
             const string args[] = {"lsblk", "-o", "FSTYPE", null};
@@ -212,6 +232,7 @@ class SnapshotBackendBox : Gtk.Box{
 	public void refresh(){
 
 		opt_btrfs.active = App.btrfs_mode;
+		opt_btrfs_readonly.active = App.btrfs_readonly;
 		type_changed();
 		update_description();
 	}