Reset instance to current vm_state if rolling back in resize_instance

You can resize a stopped instance and if the compute driver raises
InstanceFaultRollback from migrate_disk_and_power_off, the
_error_out_instance_on_exception decorator, used in the _resize_instance
method, will by default reset the instance vm_state to ACTIVE even though
the guest is stopped. The driver could raise InstanceFaultRollback if you
try resizing the root disk down on a non-volume-backed instance.

This builds on [1] and does the same thing as prep_resize [2] for
making sure the original vm_state is reset on InstanceFaultRollback.

[1] Ie4f9177f4d54cbc7dbcf58bd107fd5f24c60d8bb
[2] I17543ecb572934ecc7d0bbc7a4ad2f537fa499bc

Change-Id: Iff1f9f28a1e4ecf00368cbcac27b7687a5eb0dcf
Closes-Bug: #1551703
This commit is contained in:
Matt Riedemann 2019-10-29 12:10:08 -04:00
parent 9742a64403
commit 5a20996405
2 changed files with 28 additions and 1 deletions

View File

@ -5032,7 +5032,12 @@ class ComputeManager(manager.Manager):
def _resize_instance(self, context, instance, image,
migration, instance_type, clean_shutdown,
request_spec):
with self._error_out_instance_on_exception(context, instance), \
# Pass instance_state=instance.vm_state because we can resize
# a STOPPED server and we don't want to set it back to ACTIVE
# in case migrate_disk_and_power_off raises InstanceFaultRollback.
instance_state = instance.vm_state
with self._error_out_instance_on_exception(
context, instance, instance_state=instance_state), \
errors_out_migration_ctxt(migration):
network_info = self.network_api.get_instance_nw_info(context,
instance)

View File

@ -7829,6 +7829,28 @@ class ComputeManagerMigrationTestCase(test.NoDBTestCase,
# Assert that we set the migration to an error state
self.assertEqual("error", self.migration.status)
def test_resize_instance_fail_rollback_stays_stopped(self):
"""Tests that when the driver's migrate_disk_and_power_off method
raises InstanceFaultRollback that the instance vm_state is preserved
rather than reset to ACTIVE which would be wrong if resizing a STOPPED
server.
"""
with self._mock_resize_instance() as (
migrate_disk_and_power_off, notify):
migrate_disk_and_power_off.side_effect = \
exception.InstanceFaultRollback(
exception.ResizeError(reason='unable to resize disk down'))
self.instance.vm_state = vm_states.STOPPED
self.assertRaises(
exception.ResizeError, self.compute.resize_instance,
context=self.context, instance=self.instance, image=self.image,
migration=self.migration,
instance_type='type', clean_shutdown=True,
request_spec=objects.RequestSpec())
# Assert the instance vm_state was unchanged.
self.assertEqual(vm_states.STOPPED, self.instance.vm_state)
def test_resize_instance_notify_failure(self):
# Raise an exception sending the end notification, which is after we
# cast the migration to the destination host