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Date: Wed, 13 Dec 2017 00:43:31 -0800
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH] xfs: include the XFS magic number in magic.h
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To: Dave Chinner <david@fromorbit.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>, Christoph Hellwig <hch@infradead.org>, linux-xfs <linux-xfs@vger.kernel.org>

On Wed, Dec 13, 2017 at 01:59:28PM +1100, Dave Chinner wrote:
> IOWs, if you need to identify a filesystem *type*, using internal
> magic numbers is not the way to do it. selinux, for example, checks
> sb->s_type->name quite a lot....

And that is bad enough to start with.  It should check for specific
features, and not the file system driver name.