From: Ted Ts'o Subject: Re: [dm-devel] EXT4-fs error (device dm-42): ext4_mb_generate_buddy:741: group 1904, 32254 clusters in bitmap, 32258 in gd Date: Thu, 7 Jun 2012 18:54:46 -0400 Message-ID: <20120607225446.GK19839@thunk.org> References: <471046920.20120604234941@eikelenboom.it> <20120605000356.GM29466@outflux.net> <1018371644.20120605224154@eikelenboom.it> <20120605210806.GB7182@thunk.org> <1883708187.20120606090126@eikelenboom.it> <1482118647.20120606164012@eikelenboom.it> <20120607042756.GA30776@thunk.org> <20120607222729.GI6938@tux1.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: djwong@us.ibm.com, Sander Eikelenboom , Linus Torvalds , dm-devel@redhat.com, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: Kees Cook Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:48408 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756834Ab2FGWyy (ORCPT ); Thu, 7 Jun 2012 18:54:54 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Jun 07, 2012 at 03:40:40PM -0700, Kees Cook wrote: > > FWIW, I was building the filesystem that triggered this as ext4: > > mkfs.ext4 -T default -m 0 -O ^huge_file,^flex_bg -E > discard,lazy_itable_init /dev/mapper/... Ouy of curiosity, was there a reason you chose those particular file system parameters? It's a surprising set, because if you're starting with a fresh file system, enabling flex_bg produces a more optimal file system layout. The reason why I wrote the commit description way I did was because it seemed to be the most likely way that someone would trip across this bug. We didn't notice this for as long as we did since most of the users of ext4 (especially those who use community distributions) have been using freshly mkfs'ed ext4 file systems. - Ted