This reverts commit 9da773aa46.
There are several problems related to the --delete-qgroup option:
- Currently kernel doesn't allow to delete non-empty qgroups
- A qgroup can only be empty after fully dropped and a transaction is
committed
The tool doesn't take either factor into consideration
- Things like drop_subtree_threshold or other operations can mark qgroup
inconsistent and skip accounting
This can mean the target qgroup will never be empty until next rescan
On the other hand, even we do it the proper way, it would hugely delay
the command (wait until the subvolume to be cleaned).
Furthermore, even if the waiting is handled properly,
drop_subtree_threshold can still prevent us deleting the qgroup (qgroup
numbers are inconsistent, and accounting is skipped completely).
So the qgroup cleanup needs kernel to make it work properly.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
99447fb708