From mboxrd@z Thu Jan 1 00:00:00 1970 From: Detlev Zundel Date: Fri, 19 Nov 2010 12:03:30 +0100 Subject: [U-Boot] request for ubifs recovery support In-Reply-To: <4CE41B2F.1010709@free.fr> (Albert ARIBAUD's message of "Wed, 17 Nov 2010 19:13:03 +0100") References: <20100917164438.GA4226@localhost> <1290009710.8950.37.camel@dubciaranr0.verifone.com> <4CE40211.3050000@free.fr> <1290016909.8950.53.camel@dubciaranr0.verifone.com> <4CE41B2F.1010709@free.fr> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Albert, > Le 17/11/2010 19:01, Quotient Remainder a ?crit : >> Ar C?ad, 2010-11-17 ag 17:25 +0100, scr?obh Albert ARIBAUD: >> >>> Do you mean that, in Linux, you do a power cycle without (syncing and) >>> unmounting a file system that will be critical to properly booting later >>> on? If so, what is the rationale behind this too-quick power cycle? >> >> Yes, I'm testing power-fail tolerance! The RFS is mounted in sync mode >> so unless I'm missing something the sync should have occurred before the >> command prompt reappears, right? >> >>> >>> Seems to me you should start by the preventive measure of avoiding the >>> corruption in the first place (do a cp; sync; umount...) rather than >>> relying on a curative measure of recovery attempts. >> >> Ideally, yes and "sync" before power-down works but that's not what >> these tests are checking. With the RFS not in sync mode, it works; >> "sync" command with sync mount currently untested. > > > Ok, now I understand why you do this cp-then-powercycle routine. > > Granted, cp on a sync mount should have finished when you get back to > the prompt, so that's one Linux, not U-boot, issue to dig into; but > anyway, if you're testing for powerfail conditions, I guess you also > test power-cycling in the middle of the cp, so you may end up with a > corrupted ubifs anyway. Exactly. > I guess if you or Eric know how to enable ubifs recovery in u-boot, the > simplest course of action is to just go ahead and try it -- but I still > think the cp+powercycle issue is caused purely in Linux and should be > fixed there. If we use UBIFS in U-Boot then we need to be prepared for whatever state the UBIFS is in on powerup. Tolerance to power failures is one of the topmost featues of this fs (number 4 according to its webpage :) so U-Boot not having this property feels like a let down. Actually I wonder why nobody complained earlier about that... Cheers Detlev -- Man against god... God against Man... Man against nature... Nature against man... God against nature... Nature against god... a very, very funny religion. -- Zen Master D.T. Suzuki commenting on Christianity -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de