Comment # 5 on bug 1172273 from Fabian Vogt

(In reply to Thorsten Kukuk from comment #4)
> As Ignaz wrote: we can assume that a system is using transactional-updates,
> if the root filesystem is read-only.
> 
> So, if the root filesystem is read-only and snapper rollback is called,

This also matches the case when booting into a read-only snapshot on plain TW,
so it would need some additional criteria.

> map
> the given snapshot number or the current snapshot number to a btrfs ID and
> make it the new default:
> btrfs subvolume set-default $BTRFS_ID /.snapshots
> 
> afterwards, remove any cleaning algorithm from that snapshot:
> snapper ${SNAPPER_NO_DBUS} modify -c '' ${ROLLBACK_SNAPSHOT}