From: Eric Sandeen Subject: Re: ext4_mb_generate_buddy and double-free errors Date: Thu, 12 Mar 2009 21:03:53 -0500 Message-ID: <49B9BF09.6010306@redhat.com> References: <1236904175.731.12.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 To: Frank Mayhar Return-path: Received: from mx2.redhat.com ([66.187.237.31]:54912 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751150AbZCMCEE (ORCPT ); Thu, 12 Mar 2009 22:04:04 -0400 In-Reply-To: <1236904175.731.12.camel@bobble.smo.corp.google.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 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? I saw some of those reports a while back; haven't since, though don't know offhand what might have been the root cause or fix... -Eric