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Date:   Thu, 4 Nov 2021 10:34:17 -0700
From:   "Darrick J. Wong" <djwong@kernel.org>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Eric Sandeen <sandeen@sandeen.net>,
        Dan Williams <dan.j.williams@intel.com>,
        Mike Snitzer <snitzer@redhat.com>,
        Ira Weiny <ira.weiny@intel.com>, dm-devel@redhat.com,
        linux-xfs@vger.kernel.org, nvdimm@lists.linux.dev,
        linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org,
        virtualization@lists.linux-foundation.org
Subject: Re: futher decouple DAX from block devices
Message-ID: <20211104173417.GJ2237511@magnolia>
References: <20211018044054.1779424-1-hch@lst.de>
 <21ff4333-e567-2819-3ae0-6a2e83ec7ce6@sandeen.net>
 <20211104081740.GA23111@lst.de>
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On Thu, Nov 04, 2021 at 09:17:40AM +0100, Christoph Hellwig wrote:
> On Wed, Nov 03, 2021 at 12:59:31PM -0500, Eric Sandeen wrote:
> > Christoph, can I ask what the end game looks like, here? If dax is completely
> > decoupled from block devices, are there user-visible changes?
> 
> Yes.
> 
> > If I want to
> > run fs-dax on a pmem device - what do I point mkfs at, if not a block device?
> 
> The rough plan is to use the device dax character devices.  I'll hopefully
> have a draft version in the next days.

/me wonders, are block devices going away?  Will mkfs.xfs have to learn
how to talk to certain chardevs?  I guess jffs2 and others already do
that kind of thing... but I suppose I can wait for the real draft to
show up to ramble further. ;)

--D