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Date:   Tue, 10 Nov 2020 09:14:30 -0500
From:   "Theodore Y. Ts'o" <tytso@mit.edu>
To:     Michal Suchanek <msuchanek@suse.de>
Cc:     linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Ira Weiny <ira.weiny@intel.com>, Jan Kara <jack@suse.cz>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] Tristate moount option comatibility fixup
Message-ID: <20201110141430.GA2951190@mit.edu>
References: <cover.1604948373.git.msuchanek@suse.de>
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On Mon, Nov 09, 2020 at 08:10:07PM +0100, Michal Suchanek wrote:
> Hello,
> 
> after the tristate dax option change some applications fail to detect
> pmem devices because the dax option no longer shows in mtab when device
> is mounted with -o dax.

Which applications?  Name them.

We *really* don't want to encourage applications to make decisions
only based on the mount options.  For example, it could be that the
application's files will have the S_DAX flag set.

It would be a real shame if we are actively encourage applications to
use a broken configuration mechanism which was only used as a hack
while DAX was in experimental status.

						- Ted