90267b2854
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)