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From: Sergei Sharonov <sergei.sharonov@halliburton.com>
Date: Mon, 4 Apr 2005 21:08:35 +0000 (UTC)
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Subject: Re: JFFS2 and frequent/small write operations
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Hi,
> On Mon, 2005-04-04 at 17:15 +0000, Sergei Sharonov wrote:
> > I was told that O_SYNC flag for open does not work with JFFS2 (!?).
> 
> You misunderstood. On NOR flash, O_SYNC does nothing because JFFS2 is
> entirely synchronous anyway. On NAND flash, I believe that O_SYNC does
> what it is supposed to -- any write will have reached the medium before
> the write() system call returns.

Thanks, that is good to know. It was suggested by others
http://article.gmane.org/gmane.linux.drivers.mtd/12175/match=+sync
that it may not work on JFFS2. Estelle?
 
> This has nothing to do with atomicity of writes with respect to power
> failure.

Sorry for the confusion. I did not mean that O_SYNC has anything to do 
with atomicity, only that it is usually one of the ways to assure that
all the data is flushed to media. I guess I heard that O_SYNC does
not work with JFFS2, did not want to accept it and was provoking people 
to confirm or disprove it ;-)

Sergei Sharonov