storage device probing

[Kay Sievers]

HAL probes a main block device for a filesystem. Normally that fails and
the partitions get recognized after that and everything is fine.

The crazy ext filesystem has a amazing signature length of 16 bit (yes,
two bytes!) to signify a ext filesystem. If by accident that happens to be
on the disk, the main block device is offered by HAL for mounting. At the
same time the partitons get probed and announced and everything messes up.

We should at least invalidate _any_ result for a main block device if we
get a partition event for the same device. Or we let HAL probe for a
partitiontable first, but that is also slippery.

I don't see a nice solution, only invalidating a main volume result with
the first partition event, or wait a while if partiton events travel in
before we announce a possible main device filesystem.
Any ideas?

Thanks,
Kay