lxc container rootfs is attached to more than one device when rebooted or resized

[QiangGuan]

Operation details are as following:
ubuntu@lxc-gq:~$ nova list
+--------------------------------------+------+---------+------------+-------------+------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+---------+------------+-------------+------------------+
| b91adccc-408a-4bac-8835-9843afb904b9 | lxc1 | ACTIVE | None | Running | private=10.0.0.2 |
+--------------------------------------+------+---------+------------+-------------+------------------+
ubuntu@lxc-gq:~$ sudo losetup -a
/dev/loop1: [fd01]:134374 (/opt/stack/data/nova/instances/b91adccc-408a-4bac-8835-9843afb904b9/disk)
ubuntu@lxc-gq:~$ nova reboot lxc1 --hard
ubuntu@lxc-gq:~$ nova list
+--------------------------------------+------+-------------+----------------+-------------+------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+-------------+----------------+-------------+------------------+
| b91adccc-408a-4bac-8835-9843afb904b9 | lxc1 | HARD_REBOOT | rebooting_hard | Running | private=10.0.0.2 |
+--------------------------------------+------+-------------+----------------+-------------+------------------+
ubuntu@lxc-gq:~$ nova list
+--------------------------------------+------+---------+------------+-------------+------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+---------+------------+-------------+------------------+
| b91adccc-408a-4bac-8835-9843afb904b9 | lxc1 | ACTIVE | None | Running | private=10.0.0.2 |
+--------------------------------------+------+---------+------------+-------------+------------------+
ubuntu@lxc-gq:~$ sudo losetup -a
/dev/loop0: [fd01]:134374 (/opt/stack/data/nova/instances/b91adccc-408a-4bac-8835-9843afb904b9/disk)
/dev/loop1: [fd01]:134374 (/opt/stack/data/nova/instances/b91adccc-408a-4bac-8835-9843afb904b9/disk)

ubuntu@lxc-gq:~$ nova resize lxc1 m1.lxc
ubuntu@lxc-gq:~$ nova list
+--------------------------------------+------+---------------+------------+-------------+------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+---------------+------------+-------------+------------------+
| b91adccc-408a-4bac-8835-9843afb904b9 | lxc1 | VERIFY_RESIZE | None | Running | private=10.0.0.2 |
+--------------------------------------+------+---------------+------------+-------------+------------------+

ubuntu@lxc-gq:~$ sudo losetup -a
/dev/loop0: [fd01]:136419 (/opt/stack/data/nova/instances/b91adccc-408a-4bac-8835-9843afb904b9_resize/disk)
/dev/loop1: [fd01]:134374 (/opt/stack/data/nova/instances/b91adccc-408a-4bac-8835-9843afb904b9/disk)

ubuntu@lxc-gq:~$ nova resize-confirm lxc1
ubuntu@lxc-gq:~$ nova list
+--------------------------------------+------+---------+------------+-------------+------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+---------+------------+-------------+------------------+
| b91adccc-408a-4bac-8835-9843afb904b9 | lxc1 | ACTIVE | None | Running | private=10.0.0.2 |
+--------------------------------------+------+---------+------------+-------------+------------------+
ubuntu@lxc-gq:~$ vir list
Id Name State
----------------------------------------------------
9312 instance-00000052 running

ubuntu@lxc-gq:~$ sudo losetup -a
/dev/loop0: [fd01]:136419 (/opt/stack/data/nova/instances/b91adccc-408a-4bac-8835-9843afb904b9_resize/disk (deleted))
/dev/loop1: [fd01]:134374 (/opt/stack/data/nova/instances/b91adccc-408a-4bac-8835-9843afb904b9/disk)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/53069

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/53069
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=0fcbb7b286888d642d329db1299eb9f3708d1f50
Submitter: Jenkins
Branch: master

commit 0fcbb7b286888d642d329db1299eb9f3708d1f50
Author: Guan Qiang <email address hidden>
Date: Tue Oct 22 16:32:25 2013 +0800

    Fix lxc rootfs attached two devices in some action

    During resizing/rebooting a lxc container, create_domain action
    will be called and lxc rootfs will be attached to device again.
    So before this action, We need to teardown the container to
    make sure lxc_root_device is detached when container is destroyed.

    Closes-bug: #1243083
    Related-bug: #1208387

    Change-Id: Idd1862c7f212dc253b6273b07b020c86a94e658e