From: Eric Sandeen Subject: Re: ext4_mb_generate_buddy and double-free errors Date: Thu, 12 Mar 2009 22:25:10 -0500 Message-ID: <49B9D216.8040401@redhat.com> References: <1236904175.731.12.camel@bobble.smo.corp.google.com> <49B9BF09.6010306@redhat.com> <1236914533.731.15.camel@bobble.smo.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: ext4 development , Curt Wohlgemuth , mrubin To: Frank Mayhar Return-path: Received: from mx2.redhat.com ([66.187.237.31]:58025 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755228AbZCMDZR (ORCPT ); Thu, 12 Mar 2009 23:25:17 -0400 In-Reply-To: <1236914533.731.15.camel@bobble.smo.corp.google.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Frank Mayhar wrote: > 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. which makes it a little tough; can you test on upstream too to see if it persists? At this point you are becoming your own distribution (but I suppose you are used to that) ;) -Eric