MFstable/10 r290599:

MFC r266930,r289225:

r266930 (by jmg):

convert to using the _daddr_t types like newfs was...

Put the superblock in the correct possition for UFS2... There is a bug
in FFS that if we don't put it here (for UFS2), it will forcefully
relocate the superblock, and I believe cause data loss..

I have a fix for that, but w/ how many releases are broken, we won't be
able to switch to the better _FLOPPY (block 0) for this for a while..

r289225 (by sbruno):

makefs(8) leaves sblock.fs_providersize uninitialized (zero) that can be easily
checked with dumpfs(8). This may lead to other problems, f.e. geom_label kernel
module sanity checks do not like zero fs_old_size value and skips such UFS1
file system while tasting (fs_old_size derives from sblock.fs_providersize).

PR: 203704
Submitted by: eugen@grosbein.net
Reviewed by: marcel