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Date: Wed, 14 Jan 2026 07:47:35 +0100
From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Andrey Albershteyn <aalbersh@redhat.com>, fsverity@lists.linux.dev,
	linux-xfs@vger.kernel.org, ebiggers@kernel.org,
	linux-fsdevel@vger.kernel.org, aalbersh@kernel.org,
	david@fromorbit.com, hch@lst.de
Subject: Re: [PATCH v2 13/22] xfs: introduce XFS_FSVERITY_REGION_START
 constant
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On Tue, Jan 13, 2026 at 10:06:55AM -0800, Darrick J. Wong wrote:
> > hmm right, check in begin_enable() will be probably enough
> 
> I think that would probably be more of a mount-time prohibition?
> 
> Which would be worse -- any fsverity filesystem refuses to mount on
> 32-bit; or it mounts but none of the fsverity files are readable?
> 
> Alternately I guess for 32-bit you could cheat in ->iomap_begin
> by loading the fsverity artifacts into the pagecache at 1<<39 instead of
> 1<<53, provided the file is smaller than 1<<39 bytes.  Writing the
> fsverity metadata would perform the reverse translation.
> 
> (Or again we just don't allow mounting of fsverity on 32-bit kernels.)

What are the other file systems doing here?  Unless we have a good
reason to differ we should just follow the precedence.