LVM+tgt:iscsi target deleted after VM live migrate

[weiweigu]

We are using Openstack Icehouse version.The backend is LVM+tgt.

1）There is a instance that have a block volume attached. In the cinder volume node, 'tgt-admin --show' can get the target info:
# tgt-admin -s
Target 1: iqn.2010-10.org.openstack:volume-03371fb7-c3d2-4e07-8d9e-8d6e75757e75
    System information:
        Driver: iscsi
        State: ready
    I_T nexus information:
        I_T nexus: 10
            Initiator: iqn.opencos.rh:f59f5aaff535 alias: 2C5-10_DELL02
            Connection: 0
                IP Address: 10.43.203.5
    ......

2）After live migrating the instance ,'tgt-admin --show' return null.
# tgt-admin -s
#
The bug seems the source node request terminate_connection to cinder volume,and cinder volume excute'remove_iscsi_target', and delete the iscsi target force.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/314559

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/338721

[OpenStack Infra (hudson-openstack)]

Change abandoned by Weiwei Gu (<email address hidden>) on branch: master
Review: https://review.openstack.org/314559
Reason: I commit a new patch.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Sean McGinnis (<email address hidden>) on branch: master
Review: https://review.openstack.org/338721
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.

[Sean McGinnis (sean-mcginnis)]

Unassigning due to no activity for > 6 months.