When newfs'ing a partition with UFS2 that had previously been newfs'ed

with UFS1, the UFS1 superblocks were not deleted. This allowed any
RELENG_4 (or other non-UFS2-aware) fsck to think it knew how to "fix"
the file system, resulting in severe data scrambling.

This patch is a more advanced version than the one originally submitted.
Lukas improved it based on feedback from Kirk, and testing by me. It
blanks all UFS1 superblocks (if any) during a UFS2 newfs, thereby causing
fsck's that are not UFS2 aware to generate the "SEARCH FOR ALTERNATE
SUPER-BLOCK FAILED" message, and exit without damaging the fs.

PR:		bin/51619
Submitted by:	Lukas Ertl <l.ertl@univie.ac.at>
Reviewed by:	kirk
Approved by:	re (scottl)

0 files changed, 0 insertions, 0 deletions