From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 0/9] target: Add support for COMPARE_AND_WRITE (VAAI)
	emulation
Date: Tue, 20 Aug 2013 23:29:12 +0200
Message-ID: <20130820212912.GA9483@lst.de>
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To: "Nicholas A. Bellinger" <nab@daterainc.com>
Cc: target-devel <target-devel@vger.kernel.org>, lkml <linux-kernel@vger.kernel.org>, linux-scsi <linux-scsi@vger.kernel.org>, Christoph Hellwig <hch@lst.de>, Hannes Reinecke <hare@suse.de>, Martin Petersen <martin.petersen@oracle.com>, Chris Mason <chris.mason@fusionio.com>, James Bottomley <JBottomley@Parallels.com>, Nicholas Bellinger <nab@linux-iscsi.org>
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On Tue, Aug 20, 2013 at 08:07:51PM +0000, Nicholas A. Bellinger wrote:
> 
> It's also currently lacking the necessary sychronization between I/O
> submission of COMPARE_AND_WRITE verify instance and write instance
> user data, which is still being worked on in order to avoid additional
> overhead in the main I/O fast path.

I don't think merging such a non-conforming implementation makes any sense.

Also for a complex command like this with all it's race potential I would
really like to see some test cases to go along with it.