Re: [PATCH 05/25] vfs: avoid problematic remapping requests into partial EOF block

Filipe Manana
2018-11-02T18:18:45Z

On Fri, Nov 2, 2018 at 5:42 PM Darrick J. Wong <darrick.wong@oracle.com> wrote:
>
> On Fri, Nov 02, 2018 at 12:04:39PM +0000, Filipe Manana wrote:
> > On Mon, Oct 15, 2018 at 1:31 AM Dave Chinner <david@fromorbit.com> wrote:
> > >
> > > On Fri, Oct 12, 2018 at 09:22:18PM +0100, Filipe Manana wrote:
> > > > On Thu, Oct 11, 2018 at 5:13 AM Darrick J. Wong <darrick.wong@oracle.com> wrote:
> > > > >
> > > > > From: Darrick J. Wong <darrick.wong@oracle.com>
> > > > >
> > > > > A deduplication data corruption is exposed by fstests generic/505 on
> > > > > XFS.
> > > >
> > > > (and btrfs)
> > > >
> > > > Btw, the generic test I wrote was indeed numbered 505, however it was
> > > > never committed and there's now a generic/505 which has nothing to do
> > > > with deduplication.
> > > > So you should update the changelog to avoid confusion.
> > >
> > > What test is it now? And if it hasn't been committed, are you going
> > > to update it and repost as it clearly had value....
> >
> > Sorry, I lost track of this.
> >
> > So what was the conclusion of the thread where discussion about this
> > problem started?
> > It wasn't clear to me if a consensus was reached and got lost on that
> > long user space dedupe tools discussion between you and Zygo.
> >
> > The test assumed a fix of rounding down the range and deduping less
> > bytes then requested (which ended up included in 4.19 for btrfs).
> >
> > From this vfs patch it seems it was decided to return errno -EDADE instead.
> > Is this the final decision?
>
> No, I reworked the whole mess to match btrfs-4.19 behavior of deduping
> fewer bytes than requested.

What about cloning?
For cloning the issue is still not fixed in btrfs either.

So was that done in a later version of this patchset or somewhere else?

thanks

>
> --D
>
> > >
> > > Cheers,
> > >
> > > Dave.
> > > --
> > > Dave Chinner
> > > david@fromorbit.com
> >
> >
> >
> > --
> > Filipe David Manana,
> >
> > “Whether you think you can, or you think you can't — you're right.”

--
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”