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

Filipe Manana
2018-11-02T12:04:39Z

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?

>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@fromorbit.com

--
Filipe David Manana,

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