target_iqn is referenced before assignment after exceptions in hyperv/volumeop.py attch_volume()

[Jay Bryant]

If a exception is encountered in _login_storage_target or _get_mounted_disk_from_lun target_iqn will be referenced in the exception handler before it is defined resulting in the following traceback:

c39117134492490cba81828d080895b5 1a26ee4f153e438c806203607a0d728e] Exception during message handling
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp Traceback (most recent call last):
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\openstack\common\rpc\amqp.py", line 461, in _process_data
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp **args)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\openstack\common\rpc\dispatcher.py", line 172, in dispatch
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp result = getattr(proxyobj, method)(ctxt, **kwargs)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\exception.py", line 90, in wrapped
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp payload)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\exception.py", line 73, in wrapped
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp return f(self, context, *args, **kw)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 249, in decorated_function
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp pass
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 235, in decorated_function
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp return function(self, context, *args, **kwargs)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 277, in decorated_function
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp e, sys.exc_info())
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 264, in decorated_function
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp return function(self, context, *args, **kwargs)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 3676, in attach_volume
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp context, instance, mountpoint)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 3671, in attach_volume
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp mountpoint, instance)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 3717, in _attach_volume
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp connector)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\compute\manager.py", line 3707, in _attach_volume
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp encryption=encryption)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\virt\hyperv\driver.py", line 72, in attach_volume
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp instance['name'])
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp File "C:\Program Files (x86)\IBM\SmartCloud Entry\Hyper-V Agent\Python27\lib\site-packages\nova\virt\hyperv\volumeops.py", line 143, in attach_volume
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp self._volutils.logout_storage_target(target_iqn)
2013-10-01 16:06:19.993 5588 TRACE nova.openstack.common.rpc.amqp UnboundLocalError: local variable 'target_iqn' referenced before assignment

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/49259

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/49259
Committed: http://github.com/openstack/nova/commit/9baa186ebb578205c513c94fc621e254f4c13a08
Submitter: Jenkins
Branch: master

commit 9baa186ebb578205c513c94fc621e254f4c13a08
Author: Jay S. Bryant <email address hidden>
Date: Tue Oct 1 15:59:34 2013 -0500

    hyperv: Initialize target_iqn in attach_volume

    The target_iqn is referenced before it is declared in the
    case that an exception is encountered in _login_storage_target
    or _get_mounted_disk_from_lun. This causes the exception path
    to cause an additional, misleading, traceback to be printed
    after an exception is encountered.

    This commit initializes target_iqn at the beginning of
    attach_volume to avoid the traceback.

    Change-Id: I1cdfb9dfa054ee4f4f6918d7bc49081ccaebab9d
    Close-Bug: 1233837

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/havana
Review: https://review.openstack.org/53885

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/53885
Committed: http://github.com/openstack/nova/commit/3432e99268456ad77c9abb0ea0af1ef5a18d2929
Submitter: Jenkins
Branch: stable/havana

commit 3432e99268456ad77c9abb0ea0af1ef5a18d2929
Author: Jay S. Bryant <email address hidden>
Date: Tue Oct 1 15:59:34 2013 -0500

    hyperv: Initialize target_iqn in attach_volume

    The target_iqn is referenced before it is declared in the
    case that an exception is encountered in _login_storage_target
    or _get_mounted_disk_from_lun. This causes the exception path
    to cause an additional, misleading, traceback to be printed
    after an exception is encountered.

    This commit initializes target_iqn at the beginning of
    attach_volume to avoid the traceback.

    Closes-Bug: 1233837
    Change-Id: I1cdfb9dfa054ee4f4f6918d7bc49081ccaebab9d
    (cherry picked from commit 9baa186ebb578205c513c94fc621e254f4c13a08)