cvs commit: src/sys/ufs/ffs ffs_extern.h ffs_softdep.c ffs_vfsops.c

[Alfred Perlstein]

* Scott Long <scottl at freebsd.org> [050403 06:41] wrote:
> On Sun, 3 Apr 2005, Jeff Roberson wrote:
> >jeff        2005-04-03 10:29:55 UTC
> >
> > FreeBSD src repository
> >
> > Modified files:
> >   sys/ufs/ffs          ffs_extern.h ffs_softdep.c ffs_vfsops.c
> > Log:
> >  - Move the contents of softdep_disk_prewrite into ffs_geom_strategy to 
> >  fix
> >    two bugs.
> >  - ffs_disk_prewrite was pulling the vp from the buf and checking for
> >    COPYONWRITE, when really it wanted the vp from the bufobj that we're
> >    writing to, which is the devvp.  This lead to us skipping the copy on
> >    write to all file data, which significantly broke snapshots for the
> >    last few months.
> >  - When the SOFTUPDATES option was not included in the kernel config we
> >    would also skip the copy on write check, which would effectively 
> >    disable
> >    snapshots.
> 
> I thought that snapshots required softupdates?

Not really, it's just the combination of the two that allows for
bgfsck.  Actually I'm trying to think of the situation where softdep
is actually required because sync metadata updates should do the
same thing as softdeps in theory (just slower).

-- 
- Alfred Perlstein
- Research Engineering Development Inc.
- email: bright at mu.org cell: 408-480-4684