From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mo6-p00-ob.rzone.de ([2a01:238:20a:202:5300::1]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vlc5e-000671-8l for linux-mtd@lists.infradead.org; Wed, 27 Nov 2013 10:11:26 +0000 Received: from [192.168.0.195] (pD9E0E8BF.dip0.t-ipconnect.de [217.224.232.191]) by smtp.strato.de (RZmta 32.16 DYNA|AUTH) with (TLSv1.0:DHE-RSA-AES256-SHA encrypted) ESMTPSA id c02a2fpARAB4Bum for ; Wed, 27 Nov 2013 11:11:04 +0100 (CET) Message-ID: <5295C538.6040207@elreha.de> Date: Wed, 27 Nov 2013 11:11:04 +0100 From: "Albrecht, Harald" MIME-Version: 1.0 To: linux-mtd@lists.infradead.org Subject: JFFS2 Garbage collection issue Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi all, we are currently facing a problem with the Garbage-collection on a JFFS2 file system. We have an embedded linux system based on an ARM9 AT91RM9200 processor with an Intel / Micron JS28F256 NOR-flash of 32MB in size. The Flash holds the U-Boot loader and its environment and in the main part (30MB) of the chip a JFFS2-based root-file-system. Our Linux kernel version is 2.6.24.3 Some minutes after startup of the system, the garbage collector (gc.c) does a scan of the file system, gathering information for the garbage collection procedures that may be initiated based upon that data. On some file systems, especially such with long runtime and therefore many file operations, this scan consumes a lot of time. On some systems it stays in that scan for more that 10 minutes. The problem with this behaviour is the fact, that during the scan the file system is locked, and therefore all file operations are suspended. This leads to a crash of the system, when the application program hangs for a long time, waiting for a file operation to return from a system call, and the watchdog is not triggered. In a test system without watchdog, after the scan, the system runs normally. The flash chip itself shows no errors, so it seems to be a problem of the file system. Any idea or suggestion to solve the problem would be very welcome! Harald Albrecht