From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail2.shareable.org ([80.68.89.115]) by bombadil.infradead.org with esmtps (Exim 4.68 #1 (Red Hat Linux)) id 1K8wdd-00053N-Ot for linux-mtd@lists.infradead.org; Wed, 18 Jun 2008 12:19:46 +0000 Date: Wed, 18 Jun 2008 13:19:36 +0100 From: Jamie Lokier To: Iwo Mergler Subject: Re: [BUG] JFFS2 power loss recovery issues on NAND Message-ID: <20080618121936.GD305@shareable.org> References: <48570D5A.1050906@call-direct.com.au> <48577212.9070004@parrot.com> <48584DE9.3000709@call-direct.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48584DE9.3000709@call-direct.com.au> Cc: linux-mtd@lists.infradead.org, joern@logfs.org, dwmw2@infradead.org, Alexey Korolev , Matthieu CASTET List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Iwo Mergler wrote: > Forgive my ignorance - does that mean that not everything in JFFS2 is > CRC protected? I think every _individual_ record is CRC protected in JFFS2 _But_ that doesn't always detect file corruption. If JFFS2 records don't match their CRC, they are treated as if not there. If there's corrupt data records, that causes holes in files. There's no I/O error reported to the application, just blocks of zero bytes. There's no mechanism in JFFS2 to detect that. It requires checksums at a higher level than individual records. -- Jamie