Re: Fix(es) for ext2 fsync bug

[Dave Kleikamp <shaggy@linux.vnet.ibm.com>]

On Thu, 2007-02-15 at 10:59 -0500, sfaibish wrote:
> On Thu, 15 Feb 2007 10:09:22 -0500, Dave Kleikamp  
> <shaggy@linux.vnet.ibm.com> wrote:
> 
> > On Thu, 2007-02-15 at 09:20 -0500, Theodore Tso wrote:
> >
> >> Another very heavyweight approach would be to simply force a full sync
> >> of the filesystem whenever fysnc() is called.  Not pretty, and without
> >> the proper write ordering, the race is still potentially there.
> >
> > I don't think this race is an issue, in that it would require the crash
> > to happen before the fsync completed, so there would be no expectation
> > that the data is safe.  It's a moot point, since I don't think this is
> > an acceptable solution anyway.
> >
> >> I'd say that the best way to handle this is in fsck, but quite frankly
> >> it's relatively low priority "bug" to handle, since a much simpler
> >> workaround is to tell people to use ext3 instead.
> >
> > Right.  Who's still using ext2?
> It was my understanding from the persentation of Dawson that ext3 and jfs  
> have
> same problem.

Hmm.  If jfs has the problem, it is a bug.  jfs is designed to handle
this correctly.  I'm pretty sure I've fixed at least one bug that
eXplode has uncovered in the past.  I'm not sure what was mentioned in
the presentation though.  I'd like any information about current
problems in jfs.

> It is not an ext2 only problem. Also whatever solution we  
> adopt
> we need to be sure that we test it using the eXplode methodology.
> 
> /Sorin
-- 
David Kleikamp
IBM Linux Technology Center