when using multiple backend with block device driver, host option does't match db records

[Yaguang Tang]

cinder master configured to use multiple backend

add
enabled_backends = 'driver1, driver2'

[driver1]
volume_driver=cinder.volume.drivers.block_device.BlockDeviceDriver
available_devices = '/dev/loop4,/dev/loop5'
volume_backend_name = sata

[driver2]
volume_driver=cinder.volume.drivers.block_device.BlockDeviceDriver
available_devices = '/dev/loop6'
volume_backend_name = ssd

 to cinder.conf

when debuging , self.configuration.host is None if you haven't defined host under a volume backend, even you have specified host under a volume backend. it doesn't match the db records, volumes stores in db is the format of host@backend_name, so no volumes return from db query.

cinder/volume/drivers/block_device.py

    def _get_used_devices(self):
        lst = api.volume_get_all_by_host(context.get_admin_context(),
                                         self.configuration.host)

the value for host is expected to be hostname@driver1 or hostname@driver2
when replace self.configuration.host with self.host, it works as expected.

so I believe the bug affects master.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/101794

[Huang Zhiteng (zhiteng-huang)]

File "/opt/stack/cinder/cinder/volume/drivers/block_device.py", line 180, in _get_used_devices
    CONF.configuration.host)

This line looks suspicious. It is self.configuration.host in the driver from day 1. Can you verify it's possible to reproduce this bug on master branch?

[Yaguang Tang (heut2008)]

@Huang Zhiteng，

I can't reproduce it in master, but the bug exists in stable/icehouse, exception info updated.

[Huang Zhiteng (zhiteng-huang)]

@Yaguang,

This change (https://review.openstack.org/#/c/95022/) may fix the bug in master branch as a side effect. You can verify and propose it to stable branch if this is the case.

[Edward Hope-Morley (hopem)]

I've backported the fix from LP 1322366:

https://review.openstack.org/#/c/103549/

I think that *should* sufficient to fix the problem described here. I was not actually able to reproduce this issue on master (probably have my conf slightly different) but the above patch would definitely be useful in I nevertheless.

@yaguang make sure your oslo.config installed in devstack is actually the one from stable/icehouse as it is possible to hit dep issues when switching between devstack versions.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/101794
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=7e43a8891018d52bd69298f11b684841b00e2523
Submitter: Jenkins
Branch: master

commit 7e43a8891018d52bd69298f11b684841b00e2523
Author: Yaguang Tang <email address hidden>
Date: Mon Jun 23 11:59:44 2014 +0800

    Fix host option isn't set when using multiple backend

    When using multiple volume backend, and volume driver is
    cinder.volume.drivers.block_device.BlockDeviceDriver, host
    option isn't set so a call to get volumes of a host returns none,
    This patch changes to use self.host instead of self.configuration.host

    Change-Id: Ide34ed29adad14b778b1a7388e9dc313241fa243
    Closes-Bug: 1332909

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/icehouse
Review: https://review.openstack.org/104746

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/104746
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=d12c513af2da07c47ffda8b4c0415cae3808f791
Submitter: Jenkins
Branch: stable/icehouse

commit d12c513af2da07c47ffda8b4c0415cae3808f791
Author: Yaguang Tang <email address hidden>
Date: Mon Jun 23 11:59:44 2014 +0800

    Fix host option isn't set when using multiple backend

    When using multiple volume backend, and volume driver is
    cinder.volume.drivers.block_device.BlockDeviceDriver, host
    option isn't set so a call to get volumes of a host returns none,
    This patch changes to use self.host instead of self.configuration.host

    Change-Id: Ide34ed29adad14b778b1a7388e9dc313241fa243
    Closes-Bug: 1332909
    (cherry picked from commit 7e43a8891018d52bd69298f11b684841b00e2523)