From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6BA2C433E0 for ; Sun, 7 Mar 2021 22:37:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B37765151 for ; Sun, 7 Mar 2021 22:37:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230475AbhCGWhI (ORCPT ); Sun, 7 Mar 2021 17:37:08 -0500 Received: from mail110.syd.optusnet.com.au ([211.29.132.97]:34124 "EHLO mail110.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229740AbhCGWhI (ORCPT ); Sun, 7 Mar 2021 17:37:08 -0500 Received: from dread.disaster.area (pa49-179-130-210.pa.nsw.optusnet.com.au [49.179.130.210]) by mail110.syd.optusnet.com.au (Postfix) with ESMTPS id 97646108AB0; Mon, 8 Mar 2021 09:37:04 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1lJ21H-0020rR-QI; Mon, 08 Mar 2021 09:37:03 +1100 Date: Mon, 8 Mar 2021 09:37:03 +1100 From: Dave Chinner To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, hch@lst.de, dchinner@redhat.com, christian.brauner@ubuntu.com Subject: Re: [PATCH v2.1 2/4] xfs: avoid buffer deadlocks when walking fs inodes Message-ID: <20210307223703.GX4662@dread.disaster.area> References: <161514874040.698643.2749449122589431232.stgit@magnolia> <161514875165.698643.17020544838073213424.stgit@magnolia> <20210307203638.GJ3419940@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210307203638.GJ3419940@magnolia> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=Tu+Yewfh c=1 sm=1 tr=0 cx=a_idp_d a=JD06eNgDs9tuHP7JIKoLzw==:117 a=JD06eNgDs9tuHP7JIKoLzw==:17 a=kj9zAlcOel0A:10 a=dESyimp9J3IA:10 a=VwQbUJbxAAAA:8 a=20KFwNOVAAAA:8 a=7-415B0cAAAA:8 a=h2mM3Y-dPZZPkediAsoA:9 a=CjuIK1q_8ugA:10 a=AjGcO6oz07-iQ99wixmX:22 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sun, Mar 07, 2021 at 12:36:38PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong > > When we're servicing an INUMBERS or BULKSTAT request or running > quotacheck, grab an empty transaction so that we can use its inherent > recursive buffer locking abilities to detect inode btree cycles without > hitting ABBA buffer deadlocks. > > Found by fuzzing an inode btree pointer to introduce a cycle into the > tree (xfs/365). > > Signed-off-by: Darrick J. Wong > --- > v2.1: actually pass tp in the bulkstat_single case > --- > fs/xfs/xfs_itable.c | 42 +++++++++++++++++++++++++++++++++++++----- > fs/xfs/xfs_iwalk.c | 32 +++++++++++++++++++++++++++----- > 2 files changed, 64 insertions(+), 10 deletions(-) Looks ok, but I can't help but wonder if this case should flag corruption if lock recursion does actually occur... Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com