From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from magic.merlins.org ([209.81.13.136]:39180 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751063Ab2J2EaD (ORCPT ); Mon, 29 Oct 2012 00:30:03 -0400 Received: from merlin by mail1.merlins.org with local (Exim 4.77 #2) id 1TSgzC-0003Dj-8h for ; Sun, 28 Oct 2012 21:30:02 -0700 Date: Sun, 28 Oct 2012 21:30:02 -0700 From: Marc MERLIN To: linux-btrfs@vger.kernel.org Subject: Re: Need help mounting laptop corrupted root btrfs. Kernel BUG at fs/btrfs/volumes.c:3707 Message-ID: <20121029043002.GA8019@merlins.org> References: <20121025195805.GA24111@merlins.org> <20121025201223.GB24111@merlins.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20121025201223.GB24111@merlins.org> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Oct 25, 2012 at 01:12:23PM -0700, Marc MERLIN wrote: > On Thu, Oct 25, 2012 at 02:03:49PM -0600, cwillu wrote: > > > 3) Want me to try btrfsck although it may make it impossible for me to > > > reproduce the bug and test a fix, as well as potentially break the filesystem > > > more (last time I tried btrfsck, it outputted thousands of lines and never converged > > > to a state it was happy with) > > > > This looks like something btrfs-zero-log would work around (although > > -o recovery should do mostly the same things). That would destroy the > > evidence though, and may just make things (slightly) worse, so I'd > > wait to see if anyone suggests something better before trying it. If > > you're ultimately ending up restoring from backup though, it may save > > you that effort at least. > > Thanks for pointing out btrfs-zero-log, I hadn't re-read the wiki page since > this got added. > But I'll hold off at least until tomorrow morning (GMT-7). I'm a bit surprised that no one seems to be replying on btrfs crashes, that's a bit worrisome. I'm willing to risk my data somewhat, but if finding a problem doesn't help fixing the code, I'm not sure if I'm helping anymore :-/ Since I ran out of time, I tried: gandalfthegreat:~# btrfs-zero-log usage: btrfs-zero-log dev Btrfs Btrfs v0.19 gandalfthegreat:~# btrfs-zero-log /dev/mapper/bootdsk Check tree block failed, want=7533391872, have=17347973115472321934 Check tree block failed, want=7533391872, have=17347973115472321934 Check tree block failed, want=7533391872, have=8450612919225897562 Check tree block failed, want=7533391872, have=17347973115472321934 Check tree block failed, want=7533391872, have=17347973115472321934 read block failed check_tree_block gandalfthegreat:~# So from here, unless someone chimes in tomorrow, I'm going to have to wipe my filesystem and start over. I suppose that means btrfs can likely still cause unknown and unfixable corruption. Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/