Wie auf btrfs-cleaner warten?

# btrfs subvolume delete --help

usage: btrfs subvolume delete [options] <subvolume> [<subvolume>...]

    Delete subvolume(s)

    Delete subvolumes from the filesystem. The corresponding directory

    is removed instantly but the data blocks are removed later.

    The deletion does not involve full commit by default due to

    performance reasons (as a consequence, the subvolume may appear again

    after a crash). Use one of the --commit options to wait until the

    operation is safely stored on the media.

    -c|--commit-after      wait for transaction commit at the end of the operation

    -C|--commit-each       wait for transaction commit after deleting each subvolume

    -v|--verbose           verbose output of operations