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From:   Jeff Moyer <jmoyer@redhat.com>
To:     Ira Weiny <ira.weiny@intel.com>
Cc:     linux-kernel@vger.kernel.org,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Chinner <david@fromorbit.com>,
        Christoph Hellwig <hch@lst.de>,
        "Theodore Y. Ts'o" <tytso@mit.edu>, Jan Kara <jack@suse.cz>,
        linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
        linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v3 00/12] Enable per-file/directory DAX operations V3
References: <20200208193445.27421-1-ira.weiny@intel.com>
        <x49imke1nj0.fsf@segfault.boston.devel.redhat.com>
        <20200211201718.GF12866@iweiny-DESK2.sc.intel.com>
Date:   Wed, 12 Feb 2020 14:49:48 -0500
In-Reply-To: <20200211201718.GF12866@iweiny-DESK2.sc.intel.com> (Ira Weiny's
        message of "Tue, 11 Feb 2020 12:17:18 -0800")
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Ira Weiny <ira.weiny@intel.com> writes:

> On Mon, Feb 10, 2020 at 10:15:47AM -0500, Jeff Moyer wrote:
>> Hi, Ira,
>> 
>> Could you please include documentation patches as part of this series?
>
> I do have an update to the vfs.rst doc in
>
> 	fs: Add locking for a dynamic DAX state
>
> I'm happy to do more but was there something specific you would like to see?
> Or documentation in xfs perhaps?

Sorry, I was referring to your statx man page addition.  It would be
nice if we could find a home for the information in your cover letter,
too.  Right now, I'm not sure how application developers are supposed to
figure out how to use the per-inode settings.

If I read your cover letter correctly, the mount option overrides any
on-disk setting.  Is that right?  Given that we document the dax mount
option as "the way to get dax," it may be a good idea to allow for a
user to selectively disable dax, even when -o dax is specified.  Is that
possible?

-Jeff