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Date: Fri, 13 Dec 2024 06:12:41 +0100
From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Carlos Maiolino <cem@kernel.org>,
	Hans Holmberg <hans.holmberg@wdc.com>, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 11/43] xfs: skip always_cow inodes in
 xfs_reflink_trim_around_shared
Message-ID: <20241213051241.GG5630@lst.de>
References: <20241211085636.1380516-1-hch@lst.de> <20241211085636.1380516-12-hch@lst.de> <20241212213857.GW6678@frogsfrogsfrogs>
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On Thu, Dec 12, 2024 at 01:38:57PM -0800, Darrick J. Wong wrote:
> On Wed, Dec 11, 2024 at 09:54:36AM +0100, Christoph Hellwig wrote:
> > xfs_reflink_trim_around_shared tries to find shared blocks in the
> > refcount btree.  Always_cow inodes don't have that tree, so don't
> > bother.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Is this a bug fix?

For the existing always_cow code it is a minor optimization.  For
the zoned code that can do COW without the rtreflink code it avoids
triggering a NULL pointer dereference.