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Date: Thu, 12 Mar 2009 12:25:27 +0200
From: Adrian Hunter <adrian.hunter@nokia.com>
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To: Iram Shahzad <iram.shahzad@jp.fujitsu.com>
Subject: Re: UBIFS recovery truncates file to zero size
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Iram Shahzad wrote:
>>> For the write back enabled case, I was expecting the
>>> following behaviour:
>>>     power went down before the file is sync-ed, so
>>>     on the next booting the file will be in its old state,
>>>     that is it will contain the contents which it had before
>>>     this write.
>>>
>>> But instead of being in the old state, it becomes empty file.
>>> Is this really expected(correct) behaviour?
>> No.  How were you updating the file?
> 
> The file is updated by a Java application in the following way.
> 
> -----
> FileOutputStream str = new FileOutputStream(aFilename);
> // some write here
> str.flush();
> str.close();
> -----
> 
> I switch off the power after confirming that the str.close() has been
> executed.
> 
> P.S:
> If I add str.getFD().sync(); after the str.flush(), the file looks good in
> the next boot. However my question still remains for the case
> when I do not call str.getFD().sync:
> "why the file becomes empty rather than being in its old state?".
> 
> Thanks
> Iram
> 
> 
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
> 

What makes you think that:

FileOutputStream str = new FileOutputStream(aFilename);

does not truncate the file to zero length?