From mboxrd@z Thu Jan  1 00:00:00 1970
From: Phillip Susi <psusi@cfl.rr.com>
Subject: Re: [RFD] BIO_RW_BARRIER - what it means for devices, filesystems,
 and dm/md.
Date: Thu, 31 May 2007 14:31:21 -0400
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Cc: Jens Axboe <jens.axboe@oracle.com>, david@lang.hm,
	Neil Brown <neilb@suse.de>, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, dm-devel@redhat.com,
	linux-raid@vger.kernel.org, Stefan Bader <Stefan.Bader@de.ibm.com>,
	Andreas Dilger <adilger@clusterfs.com>,
	Tejun Heo <htejun@gmail.com>
To: David Chinner <dgc@sgi.com>
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David Chinner wrote:
> That sounds like a good idea - we can leave the existing
> WRITE_BARRIER behaviour unchanged and introduce a new WRITE_ORDERED
> behaviour that only guarantees ordering. The filesystem can then
> choose which to use where appropriate....

So what if you want a synchronous write, but DON'T care about the order? 
   They need to be two completely different flags which you can choose 
to combine, or use individually.