Generic disks

The 2.4 gendisk object has been greatly enhanced
Now the core of the block subsystem
Does partition handling

"CIDR" addressing
Gendisks allocate a block of device numbers
These ranges can nest
/dev/sda takes minors 0-63
/dev/sda1 takes minor 1

In the future
Everything is just /dev/diskN
Device numbers become irrelevant