implement the capability to desactivate CBT on all vdi snapshot childs Implement recursive CBT deactivation for VDI snapshot chains

Add recursive CBT deactivation for VDI and all child snapshots
Delete CBT log files when present
Update parent/child references in CBT metadata

Fixes: Incomplete CBT deactivation on snapshot chains

Author: Lankou66

drivers/VDI.py

@@ -576,6 +576,20 @@ def in_sync_with_xenapi_record(self, x):
             return False
         return True
 
+    def list_vdi_snapshots(self, vdi_uuid):
+        """List UUIDs of all direct snapshots of a VDI"""
+        try:
+            vdi_ref = self.session.xenapi.VDI.get_by_uuid(vdi_uuid)
+            record = self.session.xenapi.VDI.get_record(vdi_ref)
+            return [
+                self.session.xenapi.VDI.get_uuid(ref)
+                for ref in record.get("snapshots", [])
+                if self.session.xenapi.VDI.get_uuid(ref)
+            ]
+        except Exception as error:
+            util.SMlog("Error listing snapshots for VDI %s : %s" % (vdi_ref, error))
+            return []
+
     def configure_blocktracking(self, sr_uuid, vdi_uuid, enable):
         """Function for configuring blocktracking"""
         import blktap2
@@ -616,29 +630,50 @@ def configure_blocktracking(self, sr_uuid, vdi_uuid, enable):
                     self._delete_cbt_log()
                     raise xs_errors.XenError('CBTActivateFailed',
                                              opterr=str(error))
+
             else:
-                from lock import Lock
-                lock = Lock("cbtlog", str(vdi_uuid))
-                lock.acquire()
-                try:
-                    # Find parent of leaf metadata file, if any,
-                    # and nullify its successor
-                    logpath = self._get_cbt_logpath(self.uuid)
-                    parent = self._cbt_op(self.uuid,
-                                          cbtutil.get_cbt_parent, logpath)
-                    self._delete_cbt_log()
-                    parent_path = self._get_cbt_logpath(parent)
-                    if self._cbt_log_exists(parent_path):
-                        self._cbt_op(parent, cbtutil.set_cbt_child,
-                                     parent_path, uuid.UUID(int=0))
-                except Exception as error:
-                    raise xs_errors.XenError('CBTDeactivateFailed', str(error))
-                finally:
-                    lock.release()
-                    lock.cleanup("cbtlog", str(vdi_uuid))
+                self._disable_cbt(vdi_uuid)
+
         finally:
             blktap2.VDI.tap_unpause(self.session, sr_uuid, vdi_uuid)
 
+    def _disable_cbt(self, vdi_uuid, visited=None):
+        # Prevent infite loop
+        if visited is None:
+            visited = set()
+        if vdi_uuid in visited:
+            return
+        visited.add(vdi_uuid)
+
+        from lock import Lock
+        lock = Lock("cbtlog", str(vdi_uuid))
+        lock.acquire()
+        try:
+            self.uuid = vdi_uuid
+            vdi_ref = self.session.xenapi.VDI.get_by_uuid(self.uuid)
+            vdi_record = self.session.xenapi.VDI.get_record(vdi_ref)
+            logpath = self._get_cbt_logpath(self.uuid)
+            if self._cbt_log_exists(logpath):
+                parent = self._cbt_op(self.uuid, cbtutil.get_cbt_parent, logpath)
+                self._delete_cbt_log()
+                # Find parent of leaf metadata file, if any,
+                # and nullify its successor
+                parent_path = self._get_cbt_logpath(parent)
+                if self._cbt_log_exists(parent_path):
+                    self._cbt_op(parent, cbtutil.set_cbt_child, parent_path, uuid.UUID(int=0))
+                self.session.xenapi.VDI.set_cbt_enabled(vdi_ref, False)
+            for snapshot_ref in self.list_vdi_snapshots(self.uuid):
+                snap_ref = self.session.xenapi.VDI.get_by_uuid(snapshot_ref)
+                snapshot_uuid = self.session.xenapi.VDI.get_uuid(snap_ref)
+                self._disable_cbt(snapshot_uuid, visited)
+
+        except Exception as error:
+            util.SMlog(f"Error disabling CBT for VDI {self.uuid}: {error}")
+            raise xs_errors.XenError('CBTDeactivateFailed', str(error))
+        finally:
+            lock.release()
+            lock.cleanup("cbtlog", str(vdi_uuid))
+
     def data_destroy(self, sr_uuid, vdi_uuid):
         """Delete the data associated with a CBT enabled snapshot