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Date:   Fri, 20 Aug 2021 06:11:58 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Dan Williams <dan.j.williams@intel.com>
Cc:     Christoph Hellwig <hch@lst.de>,
        "Darrick J. Wong" <djwong@kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        Andreas Gruenbacher <agruenba@redhat.com>,
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        Linux NVDIMM <nvdimm@lists.linux.dev>, cluster-devel@redhat.com
Subject: Re: [PATCH 11/30] iomap: add the new iomap_iter model
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On Thu, Aug 19, 2021 at 02:25:52PM -0700, Dan Williams wrote:
> Given most of the iomap_iter users don't care about srcmap, i.e. are
> not COW cases, they are leaving srcmap zero initialized. Should the
> IOMAP types be incremented by one so that there is no IOMAP_HOLE
> confusion? In other words, fold something like this?

A hole really means nothing to read from the source.  The existing code
also relies on that.