From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933330Ab2HPUAj (ORCPT ); Thu, 16 Aug 2012 16:00:39 -0400 Received: from li9-11.members.linode.com ([67.18.176.11]:45107 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932536Ab2HPUAd convert rfc822-to-8bit (ORCPT ); Thu, 16 Aug 2012 16:00:33 -0400 Date: Thu, 16 Aug 2012 16:00:32 -0400 From: "Theodore Ts'o" To: =?utf-8?B?THVrw6HFoQ==?= Czerner Cc: Paolo Bonzini , "Linux Kernel Mailinlinux-ext4@vger.kernel.orgg List" , linux-ext4@vger.kernel.org Subject: Re: ext4fs error "ext4_mb_generate_buddy:741:group 16, 8160 clusters in bitmap, 4064 in gd" (with repro) Message-ID: <20120816200032.GE31346@thunk.org> Mail-Followup-To: Theodore Ts'o , =?utf-8?B?THVrw6HFoQ==?= Czerner , Paolo Bonzini , "Linux Kernel Mailinlinux-ext4@vger.kernel.orgg List" , linux-ext4@vger.kernel.org References: <50238A29.3060808@redhat.com> <20120809170640.GA6607@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Content-Transfer-Encoding: 8BIT X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 16, 2012 at 04:28:07PM +0200, Lukáš Czerner wrote: > > After a little bit of tracing with the systemtap and blktrace ext4 > does not seem to be doing anything wrong and yet we get part of the > block bitmap trimmed. This lead me to the scsi_debug driver itself > and indeed it seems that we have off-by-one bug there in the > unamp_region() which is causing the problem. Thanks for finding this --- I was getting scared that ext4 users were losing data in production. It's good to know it was just a bug in the scsi_debug driver. - Ted