Comment 2 for bug 2064502

Thanks for raising this issue, Kiran

Two cases here wrt resizing a share after a snapshot's taken and then attempting to revert to that snapshot:

1) Snapshot size is 10GB, share size is 5 GB - reverting-in-place will need 10 GB:
- So, we can:

- Attempt a quota modification and claim the additional 5GB; if this isn't possible, we'd raise a QuotaExceeded error
- If we're able to get the extra quota accounted, we must check if the backend expects an "extend" request to be made before the revert request?

I don't know the answer to this. We must probably make an extend_share call to be safe, and it can be consistently honored across backends that implement revert.

2) Snapshot size is 5 GB, share size is 10 GB - reverting-in-place shouldn't shrink the share here. Backends must extend after reverting in case the share size is affected by the revert.