Revert "Use vif_type='tap' for LinuxBridge for consistency"

This reverts commit 1b987be2b5.

This probably triggered a race between nova and l2 agent when
hot-detaching VIFs.

Change-Id: I2fc20666d43942446878da358ccf4472e04ad94c
Related-Bug: #1696125

neutron/plugins/ml2/drivers/linuxbridge/agent/linuxbridge_neutron_agent.py

@@ -523,15 +523,25 @@ class LinuxBridgeManager(amb.CommonAgentManagerBase):
             # inherit from the bridge its plugged into, which will be 1500
             # at the time. See bug/1684326 for details.
             self._set_tap_mtu(tap_device_name, mtu)
-        # Check if device needs to be added to bridge
-        if not bridge_lib.BridgeDevice.get_interface_bridge(
-            tap_device_name):
+        # Avoid messing with plugging devices into a bridge that the agent
+        # does not own
+        if not device_owner.startswith(constants.DEVICE_OWNER_COMPUTE_PREFIX):
+            # Check if device needs to be added to bridge
+            if not bridge_lib.BridgeDevice.get_interface_bridge(
+                tap_device_name):
+                data = {'tap_device_name': tap_device_name,
+                        'bridge_name': bridge_name}
+                LOG.debug("Adding device %(tap_device_name)s to bridge "
+                          "%(bridge_name)s", data)
+                if bridge_lib.BridgeDevice(bridge_name).addif(tap_device_name):
+                    return False
+        else:
             data = {'tap_device_name': tap_device_name,
+                    'device_owner': device_owner,
                     'bridge_name': bridge_name}
-            LOG.debug("Adding device %(tap_device_name)s to bridge "
-                      "%(bridge_name)s", data)
-            if bridge_lib.BridgeDevice(bridge_name).addif(tap_device_name):
-                return False
+            LOG.debug("Skip adding device %(tap_device_name)s to "
+                      "%(bridge_name)s. It is owned by %(device_owner)s and "
+                      "thus added elsewhere.", data)
         return True
 
     def _set_tap_mtu(self, tap_device_name, mtu):
@@ -768,8 +778,8 @@ class LinuxBridgeManager(amb.CommonAgentManagerBase):
 
     def get_agent_configurations(self):
         configurations = {'bridge_mappings': self.bridge_mappings,
-                          'interface_mappings': self.interface_mappings,
-                          'wires_compute_ports': True}
+                          'interface_mappings': self.interface_mappings
+                          }
         if self.vxlan_mode != lconst.VXLAN_NONE:
             configurations['tunneling_ip'] = self.local_ip
             configurations['tunnel_types'] = [p_const.TYPE_VXLAN]

neutron/plugins/ml2/drivers/linuxbridge/mech_driver/mech_linuxbridge.py

@@ -36,7 +36,7 @@ class LinuxbridgeMechanismDriver(mech_agent.SimpleAgentMechanismDriverBase):
         sg_enabled = securitygroups_rpc.is_firewall_enabled()
         super(LinuxbridgeMechanismDriver, self).__init__(
             constants.AGENT_TYPE_LINUXBRIDGE,
-            portbindings.VIF_TYPE_TAP,
+            portbindings.VIF_TYPE_BRIDGE,
             {portbindings.CAP_PORT_FILTER: sg_enabled})
         lb_qos_driver.register()
 
@@ -50,13 +50,6 @@ class LinuxbridgeMechanismDriver(mech_agent.SimpleAgentMechanismDriverBase):
                         **agent['configurations'].get('bridge_mappings', {}))
         return mappings
 
-    def get_vif_type(self, context, agent, segment):
-        # TODO(kevinbenton): remove this function after we no longer support
-        # Ocata agents
-        if not agent['configurations'].get('wires_compute_ports'):
-            return portbindings.VIF_TYPE_BRIDGE
-        return self.vif_type
-
     def check_vlan_transparency(self, context):
         """Linuxbridge driver vlan transparency support."""
         return True

neutron/tests/unit/plugins/ml2/drivers/linuxbridge/agent/test_linuxbridge_neutron_agent.py

@@ -527,6 +527,15 @@ class TestLinuxBridgeManager(base.BaseTestCase):
                               p_const.TYPE_VLAN, "physnet1", None, "tap1",
                               "foo", None)
 
+    def test_add_tap_interface_owner_compute(self):
+        with mock.patch.object(ip_lib, "device_exists"):
+            with mock.patch.object(self.lbm, "ensure_local_bridge"):
+                self.assertTrue(self.lbm.add_tap_interface("123",
+                                                           p_const.TYPE_LOCAL,
+                                                           "physnet1", None,
+                                                           "tap1",
+                                                           "compute:1", None))
+
     def _test_add_tap_interface(self, dev_owner_prefix):
         with mock.patch.object(ip_lib, "device_exists") as de_fn:
             de_fn.return_value = False

neutron/tests/unit/plugins/ml2/drivers/linuxbridge/mech_driver/test_mech_linuxbridge.py

@@ -13,8 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import copy
-
 from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants
 
@@ -24,14 +22,13 @@ from neutron.tests.unit.plugins.ml2 import _test_mech_agent as base
 
 
 class LinuxbridgeMechanismBaseTestCase(base.AgentMechanismBaseTestCase):
-    VIF_TYPE = portbindings.VIF_TYPE_TAP
+    VIF_TYPE = portbindings.VIF_TYPE_BRIDGE
     CAP_PORT_FILTER = True
     AGENT_TYPE = constants.AGENT_TYPE_LINUXBRIDGE
 
     GOOD_MAPPINGS = {'fake_physical_network': 'fake_interface'}
     GOOD_TUNNEL_TYPES = ['gre', 'vxlan']
-    GOOD_CONFIGS = {'wires_compute_ports': True,
-                    'interface_mappings': GOOD_MAPPINGS,
+    GOOD_CONFIGS = {'interface_mappings': GOOD_MAPPINGS,
                     'tunnel_types': GOOD_TUNNEL_TYPES}
 
     BAD_MAPPINGS = {'wrong_physical_network': 'wrong_interface'}
@@ -81,11 +78,3 @@ class LinuxbridgeMechanismVlanTestCase(LinuxbridgeMechanismBaseTestCase,
 class LinuxbridgeMechanismGreTestCase(LinuxbridgeMechanismBaseTestCase,
                                       base.AgentMechanismGreTestCase):
     pass
-
-
-class LegacyLinuxbridgeMechanismTestCase(LinuxbridgeMechanismBaseTestCase,
-                                         base.AgentMechanismVlanTestCase):
-    """An old agent doesn't wire compute ports so it needs VIF_TYPE_BRIDGE."""
-    VIF_TYPE = portbindings.VIF_TYPE_BRIDGE
-    AGENTS = copy.deepcopy(LinuxbridgeMechanismBaseTestCase.AGENTS)
-    AGENTS[0]['configurations'].pop('wires_compute_ports')

releasenotes/notes/linuxbridge_cgroups-5943d85adace4de0.yaml

@@ -1,10 +0,0 @@
----
-prelude: >
-    The Linux Bridge driver now informs Nova to use the 'tap' interface type
-    to wire interfaces. This requires '/dev/net/tun' to be added to the
-    'cgroup_device_acl' in 'qemu.conf' before upgrading.
-upgrade:
-  - |
-    The Linux Bridge driver now informs Nova to use the 'tap' interface type
-    to wire interfaces. This requires '/dev/net/tun' to be added to the
-    'cgroup_device_acl' in 'qemu.conf' before upgrading.