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Date:   Tue, 29 Mar 2022 22:41:58 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc:     Dan Williams <dan.j.williams@intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-xfs <linux-xfs@vger.kernel.org>,
        Linux NVDIMM <nvdimm@lists.linux.dev>,
        Linux MM <linux-mm@kvack.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        "Darrick J. Wong" <djwong@kernel.org>, david <david@fromorbit.com>,
        Christoph Hellwig <hch@infradead.org>,
        Jane Chu <jane.chu@oracle.com>
Subject: Re: [PATCH v11 1/8] dax: Introduce holder for dax_device
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On Wed, Mar 16, 2022 at 09:46:07PM +0800, Shiyang Ruan wrote:
> > Forgive me if this has been discussed before, but since dax_operations
> > are in terms of pgoff and nr pages and memory_failure() is in terms of
> > pfns what was the rationale for making the function signature byte
> > based?
> 
> Maybe I didn't describe it clearly...  The @offset and @len here are
> byte-based.  And so is ->memory_failure().

Yes, but is there a good reason for that when the rest of the DAX code
tends to work in page chunks?