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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 autolearn=unavailable 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 664D7C1975A for ; Thu, 12 Mar 2020 14:48:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E1EE2071C for ; Thu, 12 Mar 2020 14:48:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="0GHuUdb8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727662AbgCLOsw (ORCPT ); Thu, 12 Mar 2020 10:48:52 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:54996 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727463AbgCLOsv (ORCPT ); Thu, 12 Mar 2020 10:48:51 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02CEihIS166479; Thu, 12 Mar 2020 14:48:45 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=nyFkPnKxBZJ81Tdhoh386KbdqzidqMjCiGxb4Zh1lzY=; b=0GHuUdb8F/Z9ZToGX65Y2uyvyPkXfPHdj1G5V+hz1HQryE+v46pS6SFKsp2qP0Cmy6s3 mYFu+UpQ+VDwAiCHL/YlcUmz7pafJH+6nGFNfBNITMy8J4UUQd2OjGNn+udY/DalMHQ1 f7QsEFbE6DkchNA1RfJsm/p4WM0A74eQBaemy0ltHiSVhVM7kbctHaJNALZoBVaVRZJi zzOuzwoBA3gezeGNpyX/wXA7150P5W7Db5Uw2WIqDFXqlQGGe2gaLvtGSNLgaM4LU57j ZuzYPSymk3eocwsur6EvJNXMcskYuMNUzug57IV+/KSXxzHDs9PcNLHniIvt9ht4D9EQ 6w== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2120.oracle.com with ESMTP id 2yp9v6d4dj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Mar 2020 14:48:45 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02CEgGhT089125; Thu, 12 Mar 2020 14:48:44 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 2yqkvmt69e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Mar 2020 14:48:44 +0000 Received: from abhmp0014.oracle.com (abhmp0014.oracle.com [141.146.116.20]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 02CEmhXY019044; Thu, 12 Mar 2020 14:48:43 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 12 Mar 2020 07:48:42 -0700 Date: Thu, 12 Mar 2020 07:48:41 -0700 From: "Darrick J. Wong" To: Tommi Rantala Cc: Christoph Hellwig , linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] xfs: fix regression in "cleanup xfs_dir2_block_getdents" Message-ID: <20200312144841.GL8045@magnolia> References: <20200312085728.22187-1-tommi.t.rantala@nokia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200312085728.22187-1-tommi.t.rantala@nokia.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9557 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=2 mlxlogscore=999 malwarescore=0 adultscore=0 bulkscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003120080 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9557 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 spamscore=0 mlxscore=0 priorityscore=1501 lowpriorityscore=0 bulkscore=0 mlxlogscore=999 phishscore=0 adultscore=0 clxscore=1011 impostorscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003120080 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2020 at 10:57:28AM +0200, Tommi Rantala wrote: > Commit 263dde869bd09 ("xfs: cleanup xfs_dir2_block_getdents") introduced > a getdents regression, when it converted the pointer arithmetics to > offset calculations: offset is updated in the loop already for the next > iteration, but the updated offset value is used incorrectly in two > places, where we should have used the not-yet-updated value. > > This caused for example "git clean -ffdx" failures to cleanup certain > directory structures when running in a container. > > Fix the regression by making sure we use proper offset in the loop body. > Thanks to Christoph Hellwig for suggestion how to best fix the code. > > Cc: Christoph Hellwig > Fixes: 263dde869bd09 ("xfs: cleanup xfs_dir2_block_getdents") > Signed-off-by: Tommi Rantala Looks ok, sorry I didn't catch this either... Reviewed-by: Darrick J. Wong How might we package this up as a fstest so we can actually do regression testing? --D > --- > fs/xfs/xfs_dir2_readdir.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/fs/xfs/xfs_dir2_readdir.c b/fs/xfs/xfs_dir2_readdir.c > index 0d3b640cf1cc..871ec22c9aee 100644 > --- a/fs/xfs/xfs_dir2_readdir.c > +++ b/fs/xfs/xfs_dir2_readdir.c > @@ -147,7 +147,7 @@ xfs_dir2_block_getdents( > xfs_off_t cook; > struct xfs_da_geometry *geo = args->geo; > int lock_mode; > - unsigned int offset; > + unsigned int offset, next_offset; > unsigned int end; > > /* > @@ -173,9 +173,10 @@ xfs_dir2_block_getdents( > * Loop over the data portion of the block. > * Each object is a real entry (dep) or an unused one (dup). > */ > - offset = geo->data_entry_offset; > end = xfs_dir3_data_end_offset(geo, bp->b_addr); > - while (offset < end) { > + for (offset = geo->data_entry_offset; > + offset < end; > + offset = next_offset) { > struct xfs_dir2_data_unused *dup = bp->b_addr + offset; > struct xfs_dir2_data_entry *dep = bp->b_addr + offset; > uint8_t filetype; > @@ -184,14 +185,15 @@ xfs_dir2_block_getdents( > * Unused, skip it. > */ > if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { > - offset += be16_to_cpu(dup->length); > + next_offset = offset + be16_to_cpu(dup->length); > continue; > } > > /* > * Bump pointer for the next iteration. > */ > - offset += xfs_dir2_data_entsize(dp->i_mount, dep->namelen); > + next_offset = offset + > + xfs_dir2_data_entsize(dp->i_mount, dep->namelen); > > /* > * The entry is before the desired starting point, skip it. > -- > 2.21.1 >