interfaces: T3871: keep bridge and bond members discoverable

An interface was passed over as soon as it had a master, which covers a VF
datapath but also every bridge, bond and VRF member. Those are still their
own card in their own slot, so the naming pass reported them as hardware
which had not appeared, on any run made while they were in use.

Skip only when the master is a device itself. That is what tells the
accelerated path, which belongs to the interface it is enslaved to, apart
from a member, which does not.

1 files changed, 20 insertions, 8 deletions

diff --git a/src/tests/test_ifname_store.py b/src/tests/test_ifname_store.py
index 2b31f93ca..664ecf2ce 100644
--- a/src/tests/test_ifname_store.py
+++ b/src/tests/test_ifname_store.py
@@ -684,10 +684,10 @@ class TestPermanentMac(unittest.TestCase):
 
 class TestDiscoverDevices(unittest.TestCase):
     """Only real, independently-addressable hardware is a naming candidate.
-    Virtual interfaces have no bus device; enslaved interfaces, SR-IOV VFs
-    and hypervisor VF datapaths are acceleration children that share another
-    interface's MAC, so naming them would invent a second interface for one
-    physical port.
+    Virtual interfaces have no bus device; SR-IOV VFs and hypervisor VF
+    datapaths are acceleration children sharing another interface's MAC, so
+    naming them would invent a second interface for one physical port. Being
+    a member of a bridge, bond or VRF says nothing about the hardware.
     """
 
     def setUp(self):
@@ -701,7 +701,8 @@ class TestDiscoverDevices(unittest.TestCase):
             patch.start()
             self.addCleanup(patch.stop)
 
-        def make(name, mac=None, has_device=True, enslaved=False, is_vf=False):
+        def make(name, mac=None, has_device=True, enslaved=False, is_vf=False,
+                 master_is_device=False):
             path = os.path.join(self.tmp, name)
             os.mkdir(path)
             if has_device:
@@ -713,6 +714,8 @@ class TestDiscoverDevices(unittest.TestCase):
             if enslaved:
                 master = os.path.join(self.tmp, f'{name}_master')
                 os.mkdir(master)
+                if master_is_device:
+                    os.mkdir(os.path.join(master, 'device'))
                 os.symlink(master, os.path.join(path, 'master'))
             if mac:
                 with open(os.path.join(path, 'address'), 'w') as f:
@@ -723,6 +726,8 @@ class TestDiscoverDevices(unittest.TestCase):
         make('br0', mac='aa:aa:aa:aa:aa:99', has_device=False)
         make('lo', has_device=False)
         make('eth8', mac='aa:aa:aa:aa:aa:08', enslaved=True)
+        make('eth7', mac='aa:aa:aa:aa:aa:07', enslaved=True,
+             master_is_device=True)
         make('eth9', mac='aa:aa:aa:aa:aa:09', is_vf=True)
         make('vf_eth0', mac='aa:aa:aa:aa:aa:00')
 
@@ -730,14 +735,21 @@ class TestDiscoverDevices(unittest.TestCase):
         return {d['name'] for d in discover_devices(self.tmp)}
 
     def test_only_physical_independent_interfaces(self):
-        self.assertEqual(self._names(), {'eth0', 'eth1'})
+        self.assertEqual(self._names(), {'eth0', 'eth1', 'eth8'})
 
     def test_virtual_interfaces_excluded(self):
         self.assertNotIn('br0', self._names())
         self.assertNotIn('lo', self._names())
 
-    def test_enslaved_interface_excluded(self):
-        self.assertNotIn('eth8', self._names())
+    def test_bridge_or_bond_member_still_discovered(self):
+        # a member is still its own card, in its own slot. Dropping it here
+        # would report the hardware as missing for as long as it is in use.
+        self.assertIn('eth8', self._names())
+
+    def test_vf_datapath_enslaved_to_its_parent_excluded(self):
+        # the accelerated path is enslaved to the interface it belongs to,
+        # which - unlike a bridge or a bond - is a device itself
+        self.assertNotIn('eth7', self._names())
 
     def test_sriov_virtual_function_excluded(self):
         # the general marker, independent of hypervisor - the previous