Re: UFS file system problem in either stable or current

On Tuesday 28 October 2003 08:42 am, Dan Strick wrote:
> On Wed, 22 Oct 2003 06:23:20 -0500, Peter Schultz wrote:
> > Dan Strick wrote:
> > > There seems to be an inconsistency between release 4.9-RC and 5.1
> > > ufs support.  If I fsck the same ufs (type 1 of course) file system
> > > on both releases, each claims that the other has left incorrect
> > > summary data in the superblock.  Presumably only one can be
> > > correct. I just don't know which to blame.
> > > ...
> >
> > There is no problem AFAIK, you just have to fsck with the matching
> > executable.  A lot has changed with FreeBSD 5, spend some time with
> > the -current archive and you will learn more.  I'm sure you noticed
> > how your findings are consistently inconsistent.
>
> Thanks for the pointer.  I eventually found at least part of the
> discussion in the -current archive.  I interpret the discussion as
> follows:
>
> The 5.x UFS1 file system turns out to be slightly incompatible with
> earlier UFS file systems.  The problem is only that it keeps the
> summary data in a different location in the superblock, but that is
> sufficient to make the file systems incompatible.  There seems to be
> no interest in making them compatible.

I need them to be compatible if possible.  I'm working on a few related 
problems, so I'm becoming more familiar with the code.  I'm willing to 
help if you have an approach in mind.  Do you know why the change was 
made?

> Suggestion: if FreeBSD 5 used a different clean flag and FreeBSD 4/5
> always cleared the other's clean flag whenever they rewrote a
> superblock, the file systems would automatically be refscked whenever
> you switched between operating systems but not after a normal reboot.

If somebody does so, please don't use the fs_state field; I have a local 
patch that uses that for a different (incompatible) purpose that I'd like 
to commit soon.

-- 

        Where am I, and what am I doing in this handbasket?

Wes Peters                                               wes_at_softweyr.com