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Date:   Mon, 15 Jun 2020 06:26:32 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     dsterba@suse.cz, Linus Torvalds <torvalds@linux-foundation.org>,
        David Sterba <dsterba@suse.com>,
        linux-btrfs <linux-btrfs@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [GIT PULL] Btrfs updates for 5.8, part 2
Message-ID: <20200615132632.GA27848@infradead.org>
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On Mon, Jun 15, 2020 at 02:57:01PM +0200, David Sterba wrote:
> On Sun, Jun 14, 2020 at 09:50:17AM -0700, Linus Torvalds wrote:
> > On Sun, Jun 14, 2020 at 4:56 AM David Sterba <dsterba@suse.com> wrote:
> > >
> > > Reverts are not great, but under current circumstances I don't see
> > > better options.
> > 
> > Pulled. Are people discussing how to make iomap work for everybody?
> > It's a bit sad if we can't have the major filesystems move away from
> > the old buffer head interfaces to a common more modern one..
> 
> Yes, it's fixable and we definitely want to move to iomap. The direct to
> buffered fallback would fix one of the problems, but this would also
> mean that xfs would start doing that. Such change should be treated more
> like a feature development than a bugfix, imposed by another filesystem,
> and xfs people rightfully complained.

We can trivially key that off a flag at least for 5.8.  I suspect the
fallback actually is the right thing for XFS in the long run for that
particular case.