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Date: Tue, 1 Oct 2024 10:41:02 +0200
From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>, axboe@kernel.dk,
	brauner@kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz,
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	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	hare@suse.de, martin.petersen@oracle.com,
	catherine.hoang@oracle.com, mcgrof@kernel.org,
	ritesh.list@gmail.com, ojaswin@linux.ibm.com
Subject: Re: [PATCH v6 4/7] xfs: Support FS_XFLAG_ATOMICWRITES
Message-ID: <20241001084102.GB20648@lst.de>
References: <20240930125438.2501050-1-john.g.garry@oracle.com> <20240930125438.2501050-5-john.g.garry@oracle.com> <20240930160349.GN21853@frogsfrogsfrogs>
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User-Agent: Mutt/1.5.17 (2007-11-01)

On Mon, Sep 30, 2024 at 09:03:49AM -0700, Darrick J. Wong wrote:
> If we're only allowing atomic writes that are 1 fsblock or less, then
> copy on write will work correctly because CoWs are always done with
> fsblock granularity.  The ioend remap is also committed atomically.
> 
> IOWs, it's forcealign that isn't compatible with reflink and you can
> drop this incompatibility.

That was my thought as well when reading through this patch.