From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga14.intel.com ([143.182.124.37]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1S9wQz-0003W7-6I for linux-mtd@lists.infradead.org; Tue, 20 Mar 2012 10:36:57 +0000 Message-ID: <1332239983.11468.14.camel@sauron.fi.intel.com> Subject: Re: UBI/UBIFS issue: corrupt empty space => switched to read-only mode From: Artem Bityutskiy To: Matteo Mattei Date: Tue, 20 Mar 2012 12:39:43 +0200 In-Reply-To: References: Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-rqLIray1nJXNJOe13vBK" Mime-Version: 1.0 Cc: linux-mtd@lists.infradead.org Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-rqLIray1nJXNJOe13vBK Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2012-03-16 at 17:14 +0100, Matteo Mattei wrote: > Hi guys, >=20 > I am working hard on UBIFS to make it works on 2.6.32 and OMAP3530. >=20 > I already posted some requests to TI forum but I have no answers up to no= w: > http://e2e.ti.com/support/embedded/linux/f/354/t/171839.aspx#627875 Well, this error was reported several times. AFAIR, there are 2 possible causes for this. 1. Your driver does not protect the empty space. Normally the driver corrects bit-flips using ECC, but some systems do not do this for empty space, i.e., for the flash regions which have been erased but have never been written. UBIFS expects to see all 0xFFs there, and if it doesn't, it reports about corrupt empty space. You can fix this by fixing the driver, at least this is what people seem to do. If this is impossible to fix, you can teach UBIFS to tolerate bit-flips in the empty space. 2. More difficult issue which no one still dares to start fixing is the unstable bits issue. I do not have time to work on this, so I offer everyone assistance, but no on so far started working on this, AFAIK. Here is the description of the issue: http://www.linux-mtd.infradead.org/doc/ubifs.html#L_unstable_bits HTH. --=20 Best Regards, Artem Bityutskiy --=-rqLIray1nJXNJOe13vBK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAABAgAGBQJPaF5vAAoJECmIfjd9wqK0w1cP/imNugwqrXleF/psXINbaiHW 8GUvBX/P688x1ny1YWe2MQ1AYy40OjyekD750FehFHlyVtFqB6qlkVsfNPgA89QM MRSPp2UZwI6JZ+j+hcVbjkUNkaARQsS5DeLCpCHIxhpBWHlWao9VlTonStrmpijx pcddrShB3PnsU7GEpLsFSiYkrNq7yA4LvVhofswCL7pD4OZnYc1l76XGjqEJwRoD T0WNkFBgjUaNvqvpnxkYKa1i4pdl20WUh+qNxC9zRBmTD+4ICA5WJPZWHMeglII8 52SOMgAl5NqKwQzTvf7BsAk+U4DhEpbTVGxst4BSXa4H8dtEgYN0Rp8CPNU7g/bq 5oKeL5/bOO4hh2PdQPEQUS6N6mpOQfQhVez6dvHU4CQImFeFqaYR39D/ZJOTUvWZ mhrtspqd1oyIhpIwnz3xih0rFxiDfn4j587xz32dqUi0Tfa41SEsF4SlHS3a6WJO nIsn+Lms2YVMoAfw7FOk0OPBBL1m7NF4/kHLhe1xBAPDJvCZjFuIzbywIekZmUpX mg/9cMHQe6HwBkHW9URAwrHaqIlMNCDSh/E8XwyQnd3M1usAZgIEeMHU4hrJp9fZ Joa+AqH3U0iUcayZyPO+WzF4iPUY5l0f4pIlbSdHal8KSCdsb8lRFwo5VXnhiIf0 HY3ppVOmrG3tAMnaphLJ =KbQc -----END PGP SIGNATURE----- --=-rqLIray1nJXNJOe13vBK--