Re: True fsync() in Linux (on IDE)

From: Hans Reiser
Date: Fri Mar 19 2004 - 03:07:38 EST


Chris Mason wrote:

On Thu, 2004-03-18 at 16:09, Peter Zaitsev wrote:


On Thu, 2004-03-18 at 13:02, Chris Mason wrote:



In the former case cache is surely not flushed.



Hmmm, is it reiser? For both 2.4 reiserfs and ext3, the flush happens
when you commit. ext3 always commits on fsync and reiser only commits
when you've changed metadata.


Oh. Yes. This is Reiser, I did not think it is FS issue.
I'll know to stay away from ReiserFS now.



For reiserfs data=ordered should be enough to trigger the needed
commits. If not, data=journal. Note that neither fs does barriers for
O_SYNC, so we're just not perfect in 2.4.

-chris


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You are not listening to Peter. As I understand it from what Peter says and your words, your implementation is wrong, and makes fsync meaningless. If so, then you need to fix it. fsync should not be meaningless even for metadata only journaling. This is a serious bug that needs immediate correction, if Peter and I understand it correctly from your words.

--
Hans

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