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Date: Mon, 21 Sep 2026 23:53:05 -0700
From: "Darrick J. Wong" <djwong@kernel.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: cem@kernel.org, stable@vger.kernel.org, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 08/14] xfs: fix maximum atomic cow length computation
Message-ID: <20260922065305.GT6283@frogsfrogsfrogs>
References: <178996120463.181988.9152653965555322220.stgit@frogsfrogsfrogs>
 <178996120721.181988.7950955477687457877.stgit@frogsfrogsfrogs>
 <arIQUbrLZNVv10Mo@infradead.org>
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In-Reply-To: <arIQUbrLZNVv10Mo@infradead.org>

On Mon, Sep 21, 2026 at 10:21:21PM -0700, Christoph Hellwig wrote:
> On Sun, Sep 20, 2026 at 11:17:04PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > LOLLM says rounddown_pow_of_two acts funny if you pass it 0, so we need
> > to catch this possibility because maybe the filesystem doesn't support
> > software atomic writes at all.
> 
> Can this happen?  Shouldn't the xfs_can_sw_atomic_write() above guard
> against this?

Hmm.  Yes it can.  I think I'll drop this one.

--D