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Date:   Thu, 15 Oct 2020 10:47:00 +0100
From:   Christoph Hellwig <hch@infradead.org>
To:     Brian Foster <bfoster@redhat.com>
Cc:     linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 1/2] iomap: use page dirty state to seek data over
 unwritten extents
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I don't think we can solve this properly.  Due to the racyness we can
always err one side.  The beauty of treating all the uptodate pages
as present data is that we err on the safe side, as applications
expect holes to never have data, while "data" could always be zeroed.