# HG changeset patch
# User Alain Leufroy
# Date 1614932978 -3600
#      Fri Mar 05 09:29:38 2021 +0100
# Node ID e2a0270f2d92e506ffe0bd42be7f7f25756fa1b9
# Parent  200ba211497961bb9b5f6de8dd87753fcf8dd024
edit: prevent broken mount point

Do not allow users to edit layers having active descendants.

diff --git a/overlayctl b/overlayctl
--- a/overlayctl
+++ b/overlayctl
@@ -610,7 +610,13 @@
     of the edited overlay.
     """
     layer = build_layer(name)
-    # XXX check descendants not active
+    to_stop = [layer for layer in _iter_descendants(layer) if layer.automountunit.is_active()]
+    if to_stop:
+        # XXX automatic stop/start
+        logger.error(
+            'You should prefere to stop the following overlays: \n\n%s\n',
+            ', '.join(x.name for x in to_stop))
+        return
     if not appended and not prepended and not removed:
         with NamedTemporaryFile() as fobj:
             fobj.write(b'# -*- encoding: utf-8 -*-\n')
diff --git a/test_overlayctl.py b/test_overlayctl.py
--- a/test_overlayctl.py
+++ b/test_overlayctl.py
@@ -471,6 +471,17 @@
             self.get_mount_dir('base1'),
         ])
 
+    def test_cannot_edit_layer_with_active_descendant(self):
+        # Because OverlayFS does not like it, we protect users from
+        # having broken mount point.
+        self.get_mount_dir('base').mkdir()
+        overlayctl.creater('lower', ['base'])
+        overlayctl.creater('layer', ['lower'])
+        self.systemctl.reset_mock()
+        self.systemctl.status.return_value = {'Active': 'active'}
+        overlayctl.editer('lower', removed=['base'])
+        self.check_mount_unit('lower', [self.get_mount_dir('base')])
+
 
 class TestMove(BaseTest):
     """Tests for the `move` command."""