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Subject: Re: linux fsync behaviour
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From: Anton Altaparmakov <aia21@cam.ac.uk>
In-Reply-To: <20140725011748.GB26465@dastard>
Date: Fri, 25 Jul 2014 08:15:09 +0100
Cc: linux-kernel <linux-kernel@vger.kernel.org>
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References: <1406241691732-911707.post@n7.nabble.com> <20140725011748.GB26465@dastard>
To: yuanh <yuanhp_china@hotmail.com>
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Hi,

On 25 Jul 2014, at 02:17, Dave Chinner <david@fromorbit.com> wrote:
> On Thu, Jul 24, 2014 at 03:41:31PM -0700, yuanh wrote:
>> Hi all,
>> 
>>   Two file descriptors are pointing the same file. When fsync is called on
>> one fd, the data written by the other fd will also be flushed? We are using
>> linux XFS.
> 
> Yes.

But beware of the common mistake of using fwrite + fsync which does not actually do what you intend at all and you must instead use fwrite + fflush + fsync...  If you are using write(2) then just fsync is obviously fine.

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
University of Cambridge Information Services, Roger Needham Building
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