From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from www.mw-itcon.de ([213.146.115.73]) by canuck.infradead.org with smtp (Exim 4.54 #1 (Red Hat Linux)) id 1EmsZi-0000xJ-RM for linux-mtd@lists.infradead.org; Thu, 15 Dec 2005 07:51:12 -0500 Message-ID: <43A166C6.5060803@mw-itcon.de> Date: Thu, 15 Dec 2005 13:51:18 +0100 From: Peter Menzebach MIME-Version: 1.0 To: Steven Scholz References: <43A1418F.3060701@imc-berlin.de> <20051215102607.GA20431@angel.research.nokia.com> <43A1609C.80705@imc-berlin.de> In-Reply-To: <43A1609C.80705@imc-berlin.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org Subject: Re: Do I have to umount JFFS2? List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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