reserve disk usage for image cache fails on a fresh hypervisor

[Balazs Gibizer]

If the image cache _base directory does not exists on the hypervisor yet and [workarounds]/reserve_disk_resource_for_image_cache = True is set in the nova compute config then nova-compute logs a stack trace [1] and resource state is not update in placement.

[1] http://paste.openstack.org/show/794993/

This issue was reported originally in https://bugs.launchpad.net/nova/+bug/1878024 by MarkMielke (mark-mielke).

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/736964

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/736964
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=a85753778f710f03616a682d294f8f638dea6baf
Submitter: Zuul
Branch: master

commit a85753778f710f03616a682d294f8f638dea6baf
Author: Balazs Gibizer <email address hidden>
Date: Fri Jun 19 11:18:04 2020 +0200

    Guard against missing image cache directory

    The original fix of bug 1878024 missed an edge case where on a fresh
    hypervisor the image cache directory hasn't been created yet. That
    directory is only created when the first image is downloaded.

    This patch makes sure that if the cache dir hasn't been created yet then
    0 disk is reserved for the cache usage instead of raising and logging an
    exception.

    Change-Id: Id1bbc955a9099de1abc11b9063fe177896646d03
    Related-Bug: #1878024
    Closes-Bug: #1884214

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ussuri
Review: https://review.opendev.org/737990

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/737990
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=a6a48e876c9c4f9a218de882270ef098d46bf767
Submitter: Zuul
Branch: stable/ussuri

commit a6a48e876c9c4f9a218de882270ef098d46bf767
Author: Balazs Gibizer <email address hidden>
Date: Fri Jun 19 11:18:04 2020 +0200

    Guard against missing image cache directory

    The original fix of bug 1878024 missed an edge case where on a fresh
    hypervisor the image cache directory hasn't been created yet. That
    directory is only created when the first image is downloaded.

    This patch makes sure that if the cache dir hasn't been created yet then
    0 disk is reserved for the cache usage instead of raising and logging an
    exception.

    Change-Id: Id1bbc955a9099de1abc11b9063fe177896646d03
    Related-Bug: #1878024
    Closes-Bug: #1884214
    (cherry picked from commit a85753778f710f03616a682d294f8f638dea6baf)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/train
Review: https://review.opendev.org/738455

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/738455
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=f26823c7805c96d155de6837a08ec34271117515
Submitter: Zuul
Branch: stable/train

commit f26823c7805c96d155de6837a08ec34271117515
Author: Balazs Gibizer <email address hidden>
Date: Fri Jun 19 11:18:04 2020 +0200

    Guard against missing image cache directory

    The original fix of bug 1878024 missed an edge case where on a fresh
    hypervisor the image cache directory hasn't been created yet. That
    directory is only created when the first image is downloaded.

    This patch makes sure that if the cache dir hasn't been created yet then
    0 disk is reserved for the cache usage instead of raising and logging an
    exception.

    Conflicts:
      nova/virt/libvirt/imagecache.py due to
      I3c49825ac0d70152b6c8ee4c8ca01546265f4b80 not in stable/train

    FileNotFoundError -> OSError changes in the test file is due to py2.7
    does not have FileNotFoundError.

    Change-Id: Id1bbc955a9099de1abc11b9063fe177896646d03
    Related-Bug: #1878024
    Closes-Bug: #1884214
    (cherry picked from commit a85753778f710f03616a682d294f8f638dea6baf)
    (cherry picked from commit a6a48e876c9c4f9a218de882270ef098d46bf767)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/stein
Review: https://review.opendev.org/740409

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/740409
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=ce1287aa7fdf56560fdc8a37c75cb5db3a10a07d
Submitter: Zuul
Branch: stable/stein

commit ce1287aa7fdf56560fdc8a37c75cb5db3a10a07d
Author: Balazs Gibizer <email address hidden>
Date: Fri Jun 19 11:18:04 2020 +0200

    Guard against missing image cache directory

    The original fix of bug 1878024 missed an edge case where on a fresh
    hypervisor the image cache directory hasn't been created yet. That
    directory is only created when the first image is downloaded.

    This patch makes sure that if the cache dir hasn't been created yet then
    0 disk is reserved for the cache usage instead of raising and logging an
    exception.

    Change-Id: Id1bbc955a9099de1abc11b9063fe177896646d03
    Related-Bug: #1878024
    Closes-Bug: #1884214
    (cherry picked from commit a85753778f710f03616a682d294f8f638dea6baf)
    (cherry picked from commit a6a48e876c9c4f9a218de882270ef098d46bf767)
    (cherry picked from commit f26823c7805c96d155de6837a08ec34271117515)