Module Name:	src
Committed By:	ross
Date:		Mon Oct  5 04:56:36 UTC 1998

Modified Files:
	src/sys/lib/libsa: ustarfs.c
Log Message:
Reserve an 8K label area on every disk, not just the first. Rewrite the block
addressing and disk changing code. Separate disk addressing into three layers.
(virtual: ustar format space spanning volumes, logical: format space relative
to current volume, and physical: standard meaning). Compute a checksum of the
disk 0 8k label area, and define a label for disk 2, 3.... Detect incorrect
disk changing order and attempt to recognize our disk 0 from its checksum.