From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Shishkin Subject: Re: [BUG] Big fiability issue? Date: Wed, 6 Apr 2016 18:32:04 +0200 Message-ID: <57053A04.5020501@gmail.com> References: <5703DD31.50604@gmail.com> <20160406092540.abbb5f64954b9ca3d18c6b95@korinar.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=hjKYR7do/IfhIa+w+lZaryfQyMS2Znx4ZRzeQwqhjj8=; b=I2Vex+ntiP2LGR7lWjandiYmcoyw1hT4HQorox2oI8BLtQkub+JF9+u7312Gp5Dkcs MgSt330y1wHggi9BE5PVp1cKgKbVm2MnloNTBcMuVc2qkD9Jmk7uxRLU5mGJQxAS6x/G DNQ9x31pMq9msXKtEeYfUL4AK/+EWXyyVfBAQCEW/JiaOLSY/zUBjZy9B7oyvL7uqD9P WasdzxcbTZ79kGpl2lG2RvHKPnDknGNfGQKOrNOEZl7XiWYKF4EONWMFvYUHeD7I/z9X 2ByHeYEuBMWkQwGvxGKAruljGIwpggCvocz1RB+xvzfBd12G5Itys7LoZtGedp5GZ2Rm POUA== In-Reply-To: <20160406092540.abbb5f64954b9ca3d18c6b95@korinar.com> Sender: reiserfs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Mathieu Belanger Cc: =?UTF-8?Q?Mathieu_B=c3=a9langer?= , Reiserfs development mailing list On 04/06/2016 04:25 PM, Mathieu Belanger wrote: > Well, I did boot systemrescuecd to fsck my /dev/sda2 and mount it ro to > do the backup and I was able to get all the data back but with a bonus : > I can mount the fscked /dev/sda2 in rw on systemrescuecd, the corruption > don't come back. SystemrescueCD is based on Gentoo I think. But the one > I got got a 3.18 kernel. Please, mount it with "no_write_barrier" option on all kernels older than 4.5.1 (not yet released). Horrible name, of course: this should sound like "no_block_write_barrier", or something like this, but it is too late to fix... Thanks, Edward. > I did manually compile the latest tools to be > sure and a got an error because 3.18 support format40 4.0.0, not 4.0.1 > but that error did not affect me. > > I will do more test with that "corrupt" partition before restorating > the backup. > > On Tue, 5 Apr 2016 17:43:45 +0200 > Edward Shishkin wrote: > >> Hello Mathieu, >> >> I found that by default reiser4 still relies on a block layer feature, >> which is not longer supported. This is so-called "barriers". And yes, >> on the power outage bad things are bound to happen. However, it >> is up to bad luck. >> >> The attached patch removes the rest of block barriers support in >> reiser4. So, now we honestly wait for IO completion of wandered >> blocks (overwrite set) before submitting a journal header (journal >> footer). >> >> Not sure if it will address your problem though. Also, data corruption >> after rw-mounting of checked (rebuild-fs) partition is still a concern. >> >> Thanks, >> Edward. >