openstack
/
nova
Code Issues Proposed changes

libvirt: persist volume attachments into config 

When you attach a volume to a running instance, only the running
xml is updated in libvirt. This is due to the usage of the
VIRT_DOMAIN_AFFECT_CURRENT flag passed to attach device. What we
really want is to affect both the config and the running xml. There
is no combination of flags that works in all states, so we explicitly
set the right combination of flags depending on the running state
of the vm.

Includes a test to test_virt_drivers to ensure the flags are passed
correctly.

Fixes bug 1071069

Change-Id: I1992748b08daf99cf03dfeb0937ad42457fff1a3
(cherry picked from commit 814e7f8c82)
This commit is contained in:
Vishvananda Ishaya 2012-10-24 16:14:36 -07:00
parent 15815057db
commit ebabd029ac
3 changed files with 32 additions and 3 deletions
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7
nova/tests/fakelibvirt.py
View File

@ -73,6 +73,8 @@ VIR_DOMAIN_XML_SECURE = 1
VIR_DOMAIN_UNDEFINE_MANAGED_SAVE = 1
VIR_DOMAIN_AFFECT_CURRENT = 0
VIR_DOMAIN_AFFECT_LIVE = 1
VIR_DOMAIN_AFFECT_CONFIG = 2
VIR_CPU_COMPARE_ERROR = -1
VIR_CPU_COMPARE_INCOMPATIBLE = 0
@ -337,7 +339,10 @@ class Domain(object):
self._def['devices']['disks'] += [disk_info]
return True
def attachDeviceFlags(self, xml, _flags):
def attachDeviceFlags(self, xml, flags):
if (flags & VIR_DOMAIN_AFFECT_LIVE and
self._state != VIR_DOMAIN_RUNNING):
raise libvirtError("AFFECT_LIVE only allowed for running domains!")
self.attachDevice(xml)
def detachDevice(self, xml):

12
nova/tests/test_virt_drivers.py
View File

@ -389,6 +389,18 @@ class _VirtDriverTestCase(_FakeDriverBackendTestCase):
instance_ref['name'],
'/mnt/nova/something')
@catch_notimplementederror
def test_attach_detach_different_power_states(self):
instance_ref, network_info = self._get_running_instance()
self.connection.power_off(instance_ref)
self.connection.attach_volume({'driver_volume_type': 'fake'},
instance_ref['name'],
'/mnt/nova/something')
self.connection.power_on(instance_ref)
self.connection.detach_volume({'driver_volume_type': 'fake'},
instance_ref['name'],
'/mnt/nova/something')
@catch_notimplementederror
def test_get_info(self):
instance_ref, network_info = self._get_running_instance()

16
nova/virt/libvirt/driver.py
View File

@ -648,7 +648,13 @@ class LibvirtDriver(driver.ComputeDriver):
self._conn.defineXML(domxml)
else:
try:
flags = (libvirt.VIR_DOMAIN_AFFECT_CURRENT)
# NOTE(vish): We can always affect config because our
# domains are persistent, but we should only
# affect live if the domain is running.
flags = libvirt.VIR_DOMAIN_AFFECT_CONFIG
state = LIBVIRT_POWER_STATE[virt_dom.info()[0]]
if state == power_state.RUNNING:
flags |= libvirt.VIR_DOMAIN_AFFECT_LIVE
virt_dom.attachDeviceFlags(conf.to_xml(), flags)
except Exception, ex:
if isinstance(ex, libvirt.libvirtError):
@ -709,7 +715,13 @@ class LibvirtDriver(driver.ComputeDriver):
domxml = virt_dom.XMLDesc(libvirt.VIR_DOMAIN_XML_SECURE)
self._conn.defineXML(domxml)
else:
flags = (libvirt.VIR_DOMAIN_AFFECT_CURRENT)
# NOTE(vish): We can always affect config because our
# domains are persistent, but we should only
# affect live if the domain is running.
flags = libvirt.VIR_DOMAIN_AFFECT_CONFIG
state = LIBVIRT_POWER_STATE[virt_dom.info()[0]]
if state == power_state.RUNNING:
flags |= libvirt.VIR_DOMAIN_AFFECT_LIVE
virt_dom.detachDeviceFlags(xml, flags)
finally:
self.volume_driver_method('disconnect_volume',