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Date:   Wed, 21 Sep 2022 19:28:51 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Dave Chinner <david@fromorbit.com>
Cc:     Dan Williams <dan.j.williams@intel.com>, akpm@linux-foundation.org,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        "Darrick J. Wong" <djwong@kernel.org>,
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        linux-xfs@vger.kernel.org, linux-mm@kvack.org,
        linux-ext4@vger.kernel.org
Subject: Re: [PATCH v2 05/18] xfs: Add xfs_break_layouts() to the inode
 eviction path
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On Thu, Sep 22, 2022 at 08:14:16AM +1000, Dave Chinner wrote:

> Where are these DAX page pins that don't require the pin holder to
> also hold active references to the filesystem objects coming from?

O_DIRECT and things like it.

The concept has been that what you called revoke is just generic code
to wait until all short term users put back their pins, as short term
uses must do according to the !FOLL_LONGTERM contract.

Jason