fsck_ufs: cannot alloc 3166749884 bytes for inoinfo

[Don Lewis]

On 26 Feb, Kris Kennaway wrote:
> A recent panic left my FS with some serious corruption, which fsck is
> unable to repair:
> 
> # fsck_ufs -b 376512 -fy /var
> Alternate super block location: 376512
> ** /dev/twed0s1e
> ** Last Mounted on
> ** Phase 1 - Check Blocks and Sizes
> fsck_ufs: cannot alloc 3166749884 bytes for inoinfo
> 
> (same holds for any superblock I've tried).

It looks like the problem is that cg_initediblk is corrupted in one of
the cylinder groups.  It should never be larger than fs_ipg, and pass5()
silently enforces this limit.  We could do the same in pass1(), except
that if it ever got set to too small a value, such as 0, fsck would
think a bunch of files were missing.