Merge "Add ability for ceph driver to report discard"

cinder/tests/unit/volume/drivers/test_rbd.py

@@ -1169,7 +1169,8 @@ class RBDTestCase(test.TestCase):
                     'auth_username': self.cfg.rbd_user,
                     'secret_type': 'ceph',
                     'secret_uuid': None,
-                    'volume_id': self.volume_a.id
+                    'volume_id': self.volume_a.id,
+                    'discard': True,
                 }
             }
             actual = self.driver.initialize_connection(self.volume_a, None)

cinder/volume/drivers/rbd.py

@@ -1035,6 +1035,7 @@ class RBDDriver(driver.CloneableImageVD,
                 'secret_type': 'ceph',
                 'secret_uuid': self.configuration.rbd_secret_uuid,
                 'volume_id': volume.id,
+                "discard": True,
             }
         }
         LOG.debug('connection data: %s', data)