Module Name:	src
Committed By:	fvdl
Date:		Fri Feb 21 15:15:50 UTC 2003

Modified Files:
	src/sbin/fsck_ffs: setup.c

Log Message:
Only check relevant fields when comparing the superblock to an alternate
superblock. Avoids false positives should fsck_ffs be run on a filesystem
that was created after the UFS2 code has been merged.

This commit is mostly a forward compatibility patch that can be pulled
up in to the 1.6 branch.

From Kirk Mckusick in FreeBSD (setup.c rev. 1.30). Original commit message:
========
When checking the alternate superblock, we used to copy any fields
that might have changed, then did a byte-by-byte comparison with
the alternate. If any unused fields got used, they had to be added
to the exception list. Such changes caused too many false alarms.
So, I have changed the comparison algorithm to compare a selected
set of fields that are not expected to change. This new algorithm
causes far fewer false hits and still does a good job of detecting
problems when they have really occurred. In particular, this change
should ease the transition to kernels supporting UFS2 which make
some significant changes to the superblock.

Sponsored by:	DARPA, NAI Labs
========


To generate a diff of this commit:
cvs rdiff -r1.56 -r1.57 src/sbin/fsck_ffs/setup.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.