cleanedup and improved select-code

zfs_autobackup/ZfsDataset.py

@@ -90,6 +90,35 @@ class ZfsDataset:
         """true if this dataset is a snapshot"""
         return self.name.find("@") != -1
 
+    def is_selected(self, value, source, inherited, ignore_received):
+        """determine if dataset should be selected for backup (called from ZfsNode)"""
+
+        # sanity checks
+        if source not in ["local", "received", "-"]:
+            # probably a program error in zfs-autobackup or new feature in zfs
+            raise (Exception(
+                "{} autobackup-property has illegal source: '{}' (possible BUG)".format(self.name, source)))
+        if value not in ["false", "true", "child", "-"]:
+            # user error
+            raise (Exception(
+                "{} autobackup-property has illegal value: '{}'".format(self.name, value)))
+
+        # now determine if its actually selected
+        if value == "false":
+            self.verbose("Ignored (disabled)")
+            return False
+        elif value == "true" or (value == "child" and inherited):
+            if source == "local":
+                self.verbose("Selected")
+                return True
+            elif source == "received":
+                if ignore_received:
+                    self.verbose("Ignored (local backup)")
+                    return False
+                else:
+                    self.verbose("Selected")
+                    return True
+
     @CachedProperty
     def parent(self):
         """get zfs-parent of this dataset. for snapshots this means it will get the filesystem/volume that it belongs

zfs_autobackup/ZfsNode.py

@@ -194,7 +194,7 @@ class ZfsNode(ExecuteNode):
             self.run(cmd, readonly=False)
 
     @CachedProperty
-    def selected_datasets(self):
+    def selected_datasets(self, ignore_received=True):
         """determine filesystems that should be backupped by looking at the special autobackup-property, systemwide
 
            returns: list of ZfsDataset
@@ -204,35 +204,32 @@ class ZfsNode(ExecuteNode):
 
         # get all source filesystems that have the backup property
         lines = self.run(tab_split=True, readonly=True, cmd=[
-            "zfs", "get", "-t", "volume,filesystem", "-o", "name,value,source", "-s", "local,inherited", "-H",
+            "zfs", "get", "-t", "volume,filesystem", "-o", "name,value,source", "-H",
             "autobackup:" + self.backup_name
         ])
 
-        # determine filesystems that should be actually backupped
+        # The returnlist of selected ZfsDataset's:
         selected_filesystems = []
-        direct_filesystems = []
+
+        # list of sources, used to resolve inherited sources
+        sources = {}
+
         for line in lines:
-            (name, value, source) = line
+            (name, value, raw_source) = line
             dataset = ZfsDataset(self, name)
 
-            if value == "false":
+            # "resolve" inherited sources
-                dataset.verbose("Ignored (disabled)")
+            sources[name] = raw_source
-
+            if raw_source.find("inherited from ") == 0:
+                inherited = True
+                inherited_from = re.sub("^inherited from ", "", raw_source)
+                source = sources[inherited_from]
             else:
-                if source == "local" and (value == "true" or value == "child"):
+                inherited = False
-                    direct_filesystems.append(name)
+                source = raw_source
 
-                if source == "local" and value == "true":
+            # determine it
-                    dataset.verbose("Selected (direct selection)")
+            if dataset.is_selected(value=value, source=source, inherited=inherited, ignore_received=ignore_received):
-                    selected_filesystems.append(dataset)
+                selected_filesystems.append(dataset)
-                elif source.find("inherited from ") == 0 and (value == "true" or value == "child"):
-                    inherited_from = re.sub("^inherited from ", "", source)
-                    if inherited_from in direct_filesystems:
-                        selected_filesystems.append(dataset)
-                        dataset.verbose("Selected (inherited selection)")
-                    else:
-                        dataset.debug("Ignored (already a backup)")
-                else:
-                    dataset.verbose("Ignored (only childs)")
 
-        return selected_filesystems
+        return selected_filesystems