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

Filipe Manana
2018-11-02T19:05:09Z

On Fri, Nov 2, 2018 at 6:18 PM Filipe Manana <fdmanana@gmail.com> wrote:
>
> 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?

Never mind, found it, it returns -EINVAL.

>
> 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.”

--
Filipe David Manana,

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