From: Alex Zhuravlev Subject: Re: [PATCH -V2 3/5] ext4: Fix the race between read_block_bitmap and mark_diskspace_used Date: Mon, 24 Nov 2008 21:03:21 +0300 Message-ID: <492AEC69.40202@sun.com> References: <1227285875-18011-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1227285875-18011-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1227285875-18011-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20081123140038.GC26473@mit.edu> <492A5453.9030801@sun.com> <20081124113323.GC8462@skywalker> <492AD821.9030506@sun.com> <20081124164300.GD8462@skywalker> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Content-Transfer-Encoding: 7BIT Cc: Theodore Tso , cmm@us.ibm.com, sandeen@redhat.com, linux-ext4@vger.kernel.org To: "Aneesh Kumar K.V" Return-path: Received: from gmp-eb-inf-2.sun.com ([192.18.6.24]:36147 "EHLO gmp-eb-inf-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752693AbYKXSDm (ORCPT ); Mon, 24 Nov 2008 13:03:42 -0500 Received: from fe-emea-09.sun.com (gmp-eb-lb-2-fe2.eu.sun.com [192.18.6.11]) by gmp-eb-inf-2.sun.com (8.13.7+Sun/8.12.9) with ESMTP id mAOI3YuP007466 for ; Mon, 24 Nov 2008 18:03:34 GMT Received: from conversion-daemon.fe-emea-09.sun.com by fe-emea-09.sun.com (Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007)) id <0KAU00301NC8NC00@fe-emea-09.sun.com> (original mail from Alex.Zhuravlev@Sun.COM) for linux-ext4@vger.kernel.org; Mon, 24 Nov 2008 18:03:34 +0000 (GMT) In-reply-to: <20081124164300.GD8462@skywalker> Sender: linux-ext4-owner@vger.kernel.org List-ID: Aneesh Kumar K.V wrote: > On Mon, Nov 24, 2008 at 07:36:49PM +0300, Alex Zhuravlev wrote: >> Aneesh Kumar K.V wrote: >>> Ok the changes was not done for this purpose. I need to make sure we >>> update bitmap and clear group_desc uninit flag after taking sb_bgl_lock >>> That means when we claim blocks we can't use mb_set_bits with >>> sb_bgl_lock because we would already be holding it. How about the below >>> change >> may I have a look at the original patch? > > http://patchwork.ozlabs.org/patch/10065/ I don't understand how a group can be "uninit" if we do some manipulations inside. both allocation and preallocation initialize group first, see in ext4_mb_init_cache() thanks, Alex