Deleting a volume in 'downloading' state should cancel the download and clean up

[Duncan Thomas]

Creating a volume from an image can take a long time, if a user changes their mind they should be able to delete the volume and have the download cancel and clean up.

[John Griffith (john-griffith)]

Seems like a good add, wishlist for sure.

[Sean McGinnis (sean-mcginnis)]

Automatically unassigning due to inactivity.

[Mannu (mannu-ray)]

there are two solution that may be taken for this,

1. when the volume is in downloading state, we will have to get reference of the downloding
process cancel it and do the clean up.
this process have ovbious drawback of getting the refrernce of the downloading process, the driver
must have a interface for canceling the the download, which may lead to changes in all the drive.

2. while delete if the vloume in downloading process. we may change the status to 'aborted'
and once when the download get completed, it will go ahead with the clean up process.

though it will take more time it will be simpler to implement with minimal changes,

I will be implementing approach 2.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/cinder/+/826607