From: Frank Mayhar Subject: Re: ext4_mb_generate_buddy and double-free errors Date: Thu, 12 Mar 2009 20:22:13 -0700 Message-ID: <1236914533.731.15.camel@bobble.smo.corp.google.com> References: <1236904175.731.12.camel@bobble.smo.corp.google.com> <49B9BF09.6010306@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: ext4 development , Curt Wohlgemuth , mrubin To: Eric Sandeen Return-path: Received: from smtp-out.google.com ([216.239.33.17]:40435 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752924AbZCMDWg (ORCPT ); Thu, 12 Mar 2009 23:22:36 -0400 In-Reply-To: <49B9BF09.6010306@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, 2009-03-12 at 21:03 -0500, Eric Sandeen wrote: > Frank Mayhar wrote: > > We're seeing errors like: > > EXT4-fs error (device sda3): ext4_mb_generate_buddy: EXT4-fs: group 3049: 21020 blocks in bitmap, 21529 in gd > > > > Usually after this the system is cleaned and in the process we see many > > "mb_free_blocks: double-free of inode x's block y(bit z in group d)". > > (In fact, we see exactly as many of these as the difference between the > > group and computed count of free blocks.) > > > > It looks like the bitmap itself is getting messed up somehow, at least > > enough to make the free count disagree with the map itself. Has anyone > > else seen something like this? Any pointers as to where to look for > > potential culprits? > > Which kernel, for starters? It's our development kernel, 2.6.26 plus as many of the ext4/jbd2 patches as we can comfortably pull in. -- Frank Mayhar Google, Inc.