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Date: Fri, 12 Apr 2024 10:21:10 -0700
From: Dan Williams <dan.j.williams@intel.com>
To: Alistair Popple <apopple@nvidia.com>, <linux-mm@kvack.org>
CC: <david@fromorbit.com>, <dan.j.williams@intel.com>, <jhubbard@nvidia.com>,
	<rcampbell@nvidia.com>, <willy@infradead.org>, <jgg@nvidia.com>,
	<linux-fsdevel@vger.kernel.org>, <jack@suse.cz>, <djwong@kernel.org>,
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	<nvdimm@lists.linux.dev>, <linux-xfs@vger.kernel.org>,
	<linux-ext4@vger.kernel.org>, <jglisse@redhat.com>, Alistair Popple
	<apopple@nvidia.com>
Subject: RE: [RFC 04/10] fs/dax: Don't track page mapping/index
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Alistair Popple wrote:
> The page->mapping and page->index fields are normally used by the
> pagecache and rmap for looking up virtual mappings of pages. FS DAX
> implements it's own kind of page cache and rmap look ups so these
> fields are unnecessary. They are currently only used to detect
> error/warning conditions which should never occur.
> 
> A future change will change the way shared mappings are detected by
> doing normal page reference counting instead, so remove the
> unnecessary checks.

Ignore my comment on patch3, I fumble fingered the reply, it was meant
to for this patch. I.e. that "future change" should just be present
before removing old logic.