Merge "Fix connecting unnecessary iSCSI sessions issue" into stable/juno

2 files changed, 62 insertions, 3 deletions

diff --git a/nova/tests/virt/libvirt/test_volume.py b/nova/tests/virt/libvirt/test_volume.py
index 0158cd5243..e1ec2c4772 100644
--- a/nova/tests/virt/libvirt/test_volume.py
+++ b/nova/tests/virt/libvirt/test_volume.py
@@ -636,6 +636,46 @@ Setting up iSCSI targets: unused
         expected_multipath_cmd = ('multipath', '-f', 'foo')
         self.assertIn(expected_multipath_cmd, self.executes)
 
+    def test_libvirt_kvm_volume_with_multipath_connecting(self):
+        libvirt_driver = volume.LibvirtISCSIVolumeDriver(self.fake_conn)
+        ip_iqns = [[self.location, self.iqn],
+                   ['10.0.2.16:3260', self.iqn],
+                   [self.location,
+                    'iqn.2010-10.org.openstack:volume-00000002']]
+
+        with contextlib.nested(
+            mock.patch.object(os.path, 'exists', return_value=True),
+            mock.patch.object(libvirt_driver, '_run_iscsiadm_bare'),
+            mock.patch.object(libvirt_driver,
+                              '_get_target_portals_from_iscsiadm_output',
+                              return_value=ip_iqns),
+            mock.patch.object(libvirt_driver, '_connect_to_iscsi_portal'),
+            mock.patch.object(libvirt_driver, '_rescan_iscsi'),
+            mock.patch.object(libvirt_driver, '_get_host_device',
+                              return_value='fake-device'),
+            mock.patch.object(libvirt_driver, '_rescan_multipath'),
+            mock.patch.object(libvirt_driver, '_get_multipath_device_name',
+                              return_value='/dev/mapper/fake-mpath-devname')
+        ) as (mock_exists, mock_run_iscsiadm_bare, mock_get_portals,
+              mock_connect_iscsi, mock_rescan_iscsi, mock_host_device,
+              mock_rescan_multipath, mock_device_name):
+            vol = {'id': 1, 'name': self.name}
+            connection_info = self.iscsi_connection(vol, self.location,
+                                                    self.iqn)
+            libvirt_driver.use_multipath = True
+            libvirt_driver.connect_volume(connection_info, self.disk_info)
+
+            # Verify that the supplied iqn is used when it shares the same
+            # iqn between multiple portals.
+            connection_info = self.iscsi_connection(vol, self.location,
+                                                    self.iqn)
+            props1 = connection_info['data'].copy()
+            props2 = connection_info['data'].copy()
+            props2['target_portal'] = '10.0.2.16:3260'
+            expected_calls = [mock.call(props1), mock.call(props2),
+                              mock.call(props1)]
+            self.assertEqual(expected_calls, mock_connect_iscsi.call_args_list)
+
     def test_libvirt_kvm_volume_with_multipath_still_in_use(self):
         name = 'volume-00000001'
         location = '10.0.2.15:3260'
diff --git a/nova/virt/libvirt/volume.py b/nova/virt/libvirt/volume.py
index 6ba543d0b3..d1d2c6ef52 100644
--- a/nova/virt/libvirt/volume.py
+++ b/nova/virt/libvirt/volume.py
@@ -285,10 +285,29 @@ class LibvirtISCSIVolumeDriver(LibvirtBaseVolumeDriver):
                                           check_exit_code=[0, 255])[0] \
                 or ""
 
-            for ip, iqn in self._get_target_portals_from_iscsiadm_output(out):
+            # There are two types of iSCSI multipath devices.  One which shares
+            # the same iqn between multiple portals, and the other which use
+            # different iqns on different portals.  Try to identify the type by
+            # checking the iscsiadm output if the iqn is used by multiple
+            # portals.  If it is, it's the former, so use the supplied iqn.
+            # Otherwise, it's the latter, so try the ip,iqn combinations to
+            # find the targets which constitutes the multipath device.
+            ips_iqns = self._get_target_portals_from_iscsiadm_output(out)
+            same_portal = False
+            all_portals = set()
+            match_portals = set()
+            for ip, iqn in ips_iqns:
+                all_portals.add(ip)
+                if iqn == iscsi_properties['target_iqn']:
+                    match_portals.add(ip)
+            if len(all_portals) == len(match_portals):
+                same_portal = True
+
+            for ip, iqn in ips_iqns:
                 props = iscsi_properties.copy()
-                props['target_portal'] = ip
-                props['target_iqn'] = iqn
+                props['target_portal'] = ip.split(",")[0]
+                if not same_portal:
+                    props['target_iqn'] = iqn
                 self._connect_to_iscsi_portal(props)
 
             self._rescan_iscsi()