Re: Do I have to umount JFFS2?

[Peter Menzebach <pm-mtd@mw-itcon.de>]

Steven Scholz wrote:
> Jarkko Lavinen wrote:
>> On Thu, Dec 15, 2005 at 11:12:31AM +0100, ext Steven Scholz wrote:
>>
>>> Now I wonder if it is needed to umount this partition explicitly before
>>> rebooting? Or mount it read only first by having
>>
>> JFFS2 is synhronous except for the write buffer (used with Nand chips).  
>> Doing sync is enough and flushes the write buffer.
> 
> Is "sync()" done by the kernel before reboot? Or do I have to call "sync"?
> 
Hi Steven,
afaik,
and this this is inline with my experience, you have call sync before 
reboot.
Since I write only complete files to jffs2, I reduced the timer, which 
flushes the write buffer automatically from 3 seconds to 500 ms.
In that case, I normally get no errors even in case of a hard reset.

Otherwise I get some "found empty flash at" and some CRC errors. The 
filesystem as whole should remain in a stable state in any case (that's 
the main reason apart from wear levelling for jffs2, I think)


Best regards
Peter


-- 
Peter Menzebach
Menzebach und Wolff IT-Consulting GbR
Phone +49 751 355 387 1