From e24f333cd5d3667a15c36ac502304bfb5a0e21df Mon Sep 17 00:00:00 2001
From: Daniel Genin <Daniel.Genin@jhuapl.edu>
Date: Mon, 28 Jul 2014 17:12:40 -0400
Subject: [PATCH] Raises NotImplementedError for LVM migration.

Currently migration of an LVM backed instance results in a new
instance being launched on the destination node, but the instance
disk is neither copied to the destination nor deleted on the
origin node. The problem is addressed by raising a NotImplementedError.

Closes-Bug: #1270305
Closes-Bug: #1245595
Closes-Bug: #1241866
Change-Id: I8010230b1aa5ddc322d0c93dd916b7700c25ab81
DocImpact
---
 nova/compute/manager.py                |  5 ++++
 nova/tests/virt/libvirt/test_driver.py | 40 ++++++++++++++++++++++++++
 nova/virt/libvirt/driver.py            |  6 ++++
 3 files changed, 51 insertions(+)

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 98f928111b45..c074bd35c7c0 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -3463,6 +3463,11 @@ class ComputeManager(manager.Manager):
                                   instance_type, quotas,
                                   request_spec, filter_properties,
                                   node)
+            # NOTE(dgenin): This is thrown in LibvirtDriver when the
+            #               instance to be migrated is backed by LVM.
+            #               Remove when LVM migration is implemented.
+            except exception.MigrationPreCheckError:
+                raise
             except Exception:
                 # try to re-schedule the resize elsewhere:
                 exc_info = sys.exc_info()
diff --git a/nova/tests/virt/libvirt/test_driver.py b/nova/tests/virt/libvirt/test_driver.py
index bb2c5266d195..27544adc2889 100644
--- a/nova/tests/virt/libvirt/test_driver.py
+++ b/nova/tests/virt/libvirt/test_driver.py
@@ -9380,6 +9380,46 @@ class LibvirtDriverTestCase(test.TestCase):
         self.assertFalse(self.copy_or_move_swap_called)
         self.assertEqual(disk_info_text, out)
 
+    def test_migrate_disk_and_power_off_lvm(self):
+        """Test for nova.virt.libvirt.libvirt_driver.LibvirtConnection
+        .migrate_disk_and_power_off.
+        """
+
+        self.flags(images_type='lvm', group='libvirt')
+        disk_info = [{'type': 'raw', 'path': '/dev/vg/disk',
+                      'disk_size': '83886080'},
+                     {'type': 'raw', 'path': '/dev/disk.local',
+                      'disk_size': '83886080'}]
+        disk_info_text = jsonutils.dumps(disk_info)
+
+        def fake_get_instance_disk_info(instance, xml=None,
+                                        block_device_info=None):
+            return disk_info_text
+
+        def fake_destroy(instance):
+            pass
+
+        def fake_get_host_ip_addr():
+            return '10.0.0.1'
+
+        def fake_execute(*args, **kwargs):
+            pass
+
+        self.stubs.Set(self.libvirtconnection, 'get_instance_disk_info',
+                       fake_get_instance_disk_info)
+        self.stubs.Set(self.libvirtconnection, '_destroy', fake_destroy)
+        self.stubs.Set(self.libvirtconnection, 'get_host_ip_addr',
+                       fake_get_host_ip_addr)
+        self.stubs.Set(utils, 'execute', fake_execute)
+
+        ins_ref = self._create_instance()
+        flavor = {'root_gb': 10, 'ephemeral_gb': 20}
+
+        # Migration is not implemented for LVM backed instances
+        self.assertRaises(exception.MigrationPreCheckError,
+              self.libvirtconnection.migrate_disk_and_power_off,
+              None, ins_ref, '10.0.0.1', flavor, None)
+
     def test_migrate_disk_and_power_off_resize_error(self):
         instance = self._create_instance()
         flavor = {'root_gb': 5}
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 6c39391ac291..5154213a5f9e 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -5096,6 +5096,12 @@ class LibvirtDriver(driver.ComputeDriver):
                 block_device_info=block_device_info)
         disk_info = jsonutils.loads(disk_info_text)
 
+        # NOTE(dgenin): Migration is not implemented for LVM backed instances.
+        if (CONF.libvirt.images_type == 'lvm' and
+                not self._is_booted_from_volume(instance, disk_info_text)):
+            reason = "Migration is not supported for LVM backed instances"
+            raise exception.MigrationPreCheckError(reason)
+
         # copy disks to destination
         # rename instance dir to +_resize at first for using
         # shared storage for instance dir (eg. NFS).