http://bugs.winehq.org/show_bug.cgi?id=58669
--- Comment #4 from Zeb Figura z.figura12@gmail.com --- Thanks. Yeah, you have enough permissions to open the partition devices (which is a bit dangerous and I wouldn't recommend it in general, but that's neither here nor there).
If we can, we try to read partition devices directly in order to determine the file system type. That maybe made sense twenty years ago, but I don't think it does anymore. We should just rely on udisks, or whatever.