storage: Add new function to execute operations

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

lib/constants.py

@@ -210,6 +210,9 @@ MODIFIABLE_STORAGE_FIELDS = {
   ST_LVM_PV: frozenset([SF_ALLOCATABLE]),
   }
 
+VALID_STORAGE_OPERATIONS = {
+  }
+
 # Local disk status
 # Note: Code depends on LDS_OKAY < LDS_UNKNOWN < LDS_FAULTY
 (LDS_OKAY,

lib/storage.py

@@ -64,6 +64,17 @@ class _Base:
       raise errors.ProgrammerError("Unable to modify the following"
                                    "fields: %r" % (changes.keys(), ))
 
+  def Execute(self, name, op):
+    """Executes an operation on an entity within the storage unit.
+
+    @type name: string
+    @param name: Entity name
+    @type op: string
+    @param op: Operation name
+
+    """
+    raise NotImplementedError()
+
 
 class FileStorage(_Base):
   """File storage unit.