From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: Proposal for "proper" durable fsync() and fdatasync()
Date: Mon, 25 Feb 2008 23:43:19 -0800
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Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Chris Wedgwood <cw@f00f.org>
To: Jamie Lokier <jamie@shareable.org>
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On Tue, 26 Feb 2008 07:26:50 +0000 Jamie Lokier <jamie@shareable.org> wrote:

> (It would be nicer if sync_file_range()
> took a vector of ranges for better elevator scheduling, but let's
> ignore that :-)

Two passes:

Pass 1: shove each of the segments into the queue with
        SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE

Pass 2: wait for them all to complete and return accumulated result
        with SYNC_FILE_RANGE_WAIT_AFTER