From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 1/1] FS: Add generic data flush to fsync
Date: Mon, 14 Apr 2014 00:22:42 -0700
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References: <20140411065242.42916952dd5d8e4e53848b3b@skynet.be>
 <20140411074522.GA15518@infradead.org>
 <20140411230530.984a9d57b3dec487af936d29@skynet.be>
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Cc: Christoph Hellwig <hch@infradead.org>,
	Viro <viro@zeniv.linux.org.uk>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	jack <jack@suse.cz>, akpm <akpm@linux-foundation.org>
To: Fabian Frederick <fabf@skynet.be>
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On Fri, Apr 11, 2014 at 11:05:30PM +0200, Fabian Frederick wrote:
> Ok, that would mean 'older' filesystems -without barrier flag-
> to call generic_file_fsync would result in a flush but ext4 without journal 
> also calls it ; maybe with nobarrier and I'm not sure it's the only case.
> How can I deal with this problem ?

I don't really think not implementing the barrier option is a problem.
For ext4 if you want consistency either opencode generic_file_fsync
there and add the check, or add a __generic_file_fsync that doesn't
do the flush.