Comment 11 for bug 1842088

Reviewed: https://review.opendev.org/c/openstack/cinder/+/809669
Committed: https://opendev.org/openstack/cinder/commit/e9ef536958d9920b70cbbf27bc7faf548ad42d36
Submitter: "Zuul (22348)"
Branch: stable/ussuri

commit e9ef536958d9920b70cbbf27bc7faf548ad42d36
Author: Sofia Enriquez <email address hidden>
Date: Wed Aug 28 17:38:50 2019 -0300

    Allow removing NFS snapshots in error status

    The NFS driver doesn't allow to delete snapshots in error state when
    snapshot support is disable.

    I'm facing some scenarios where snapshots are enabled then a snapshot
    is created and after that then snapshots are disabled. This results
    in error state snapshots that can't be deleted. Another scenario is
    - with nfs snapshot support disable from the beginning- the API layer
    allows the snapshot to be created but the NFS driver sets the status
    to "error" leaving the snapshot in the DB with error state.
    Because of that, I have snapshots in error state that I'm not able
    to delete.

    The purpose of this fix allow deleting snapshots in error state.
    It makes sense to block creating snapshots when snapshot support is
    False. However, when deleting snapshot we don't want to block
    attempts to delete a broken snapshot DB entry, which is necessary to
    clean up a failed snapshot create.

    Closes-Bug: #1842088
    Change-Id: Ieb19d5e3f58ae2343b6b145772fec33cb7517ab5
    (cherry picked from commit 5714bdb8447a38440585116f784a322143711959)
    (cherry picked from commit 5a4f3ac53a554ecaa18cbd0a49c0606dff4e1137)
    (cherry picked from commit fb0efc42149fab524a9d3a95f01b7b71e954f314)