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Date:   Fri, 14 Jun 2019 08:35:49 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Ira Weiny <ira.weiny@intel.com>
Cc:     Christoph Hellwig <hch@lst.de>,
        Dan Williams <dan.j.williams@intel.com>,
        =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
        Jason Gunthorpe <jgg@mellanox.com>,
        Ben Skeggs <bskeggs@redhat.com>, linux-nvdimm@lists.01.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linux-mm@kvack.org,
        nouveau@lists.freedesktop.org
Subject: Re: [PATCH 13/22] device-dax: use the dev_pagemap internal refcount
Message-ID: <20190614063549.GK7246@lst.de>
References: <20190613094326.24093-1-hch@lst.de> <20190613094326.24093-14-hch@lst.de> <20190614002217.GB783@iweiny-DESK2.sc.intel.com>
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On Thu, Jun 13, 2019 at 05:22:17PM -0700, Ira Weiny wrote:
> > -	dev_dax->pgmap.ref = &dev_dax->ref;
> 
> I don't think this exactly correct.  pgmap.ref is a pointer to the dev_dax ref
> structure.  Taking it away will cause devm_memremap_pages() to fail AFAICS.
> 
> I think you need to change struct dev_pagemap as well:

Take a look at the previous patch, which adds an internal_ref field
to dev_pagemap that ->ref is set up to point to if not otherwise
initialized.