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=-10.1 required=3.0 tests=BAYES_00,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 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 E1E60C433E6 for ; Mon, 31 Aug 2020 16:10:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAF71208DB for ; Mon, 31 Aug 2020 16:10:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="K6Q8Vc4N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727883AbgHaQK2 (ORCPT ); Mon, 31 Aug 2020 12:10:28 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:38496 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726249AbgHaQK1 (ORCPT ); Mon, 31 Aug 2020 12:10:27 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 07VG95Lg127460; Mon, 31 Aug 2020 16:10:22 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=hsJu86EX4gAQYrs8KNtNZDAaLhT/ez8s4LZGNo8Ixgk=; b=K6Q8Vc4N27yetx4dknOxKrFpPIOzicaNxSUUS8lTIz8PPL01lmLYSa3yfJ8lqsJxiFyl fg0TDTjomO/SebcJxyLqCX/2iEx0CgzdN7dXyv2anbiKtbnAFa2bcrL/xzQmGyyjkTcm VeRlFJbRSkK5EqM3a1zXaJh16zytfg0QVZqu04dbY6PdA52yMMp0Q/YIkaNIRqilcHX5 xvjgQs6XLLoc2Hhyq+qCYWkE1biBpMSQGPFz3ze7wllfYixE8YP8pmrWMCJNa1H665pR a1tIchOFuoeQtk8eKCQhi+oUnIcj30MqNrhats5kjcP/hehaIVUMKLLQY5ysN4XltAfz /A== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 337eeqq61y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 31 Aug 2020 16:10:21 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 07VG0bNb157807; Mon, 31 Aug 2020 16:08:21 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3020.oracle.com with ESMTP id 3380x0mbvk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 31 Aug 2020 16:08:21 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 07VG8Jhj030326; Mon, 31 Aug 2020 16:08:19 GMT Received: from localhost (/10.159.252.155) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 31 Aug 2020 09:08:19 -0700 Date: Mon, 31 Aug 2020 09:08:23 -0700 From: "Darrick J. Wong" To: Chandan Babu R Cc: linux-xfs@vger.kernel.org, david@fromorbit.com, hch@infradead.org Subject: Re: [PATCH V3 01/10] xfs: Add helper for checking per-inode extent count overflow Message-ID: <20200831160823.GG6096@magnolia> References: <20200820054349.5525-1-chandanrlinux@gmail.com> <20200820054349.5525-2-chandanrlinux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200820054349.5525-2-chandanrlinux@gmail.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9730 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 spamscore=0 phishscore=0 mlxlogscore=999 adultscore=0 suspectscore=1 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008310095 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9730 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 clxscore=1015 priorityscore=1501 lowpriorityscore=0 malwarescore=0 adultscore=0 spamscore=0 mlxscore=0 phishscore=0 impostorscore=0 mlxlogscore=999 bulkscore=0 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008310096 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Thu, Aug 20, 2020 at 11:13:40AM +0530, Chandan Babu R wrote: > XFS does not check for possible overflow of per-inode extent counter > fields when adding extents to either data or attr fork. > > For e.g. > 1. Insert 5 million xattrs (each having a value size of 255 bytes) and > then delete 50% of them in an alternating manner. > > 2. On a 4k block sized XFS filesystem instance, the above causes 98511 > extents to be created in the attr fork of the inode. > > xfsaild/loop0 2008 [003] 1475.127209: probe:xfs_inode_to_disk: (ffffffffa43fb6b0) if_nextents=98511 i_ino=131 > > 3. The incore inode fork extent counter is a signed 32-bit > quantity. However the on-disk extent counter is an unsigned 16-bit > quantity and hence cannot hold 98511 extents. > > 4. The following incorrect value is stored in the attr extent counter, > # xfs_db -f -c 'inode 131' -c 'print core.naextents' /dev/loop0 > core.naextents = -32561 > > This commit adds a new helper function (i.e. > xfs_iext_count_may_overflow()) to check for overflow of the per-inode > data and xattr extent counters. Future patches will use this function to > make sure that an FS operation won't cause the extent counter to > overflow. > > Suggested-by: Darrick J. Wong > Signed-off-by: Chandan Babu R Seems reasonable so far... Reviewed-by: Darrick J. Wong --D > --- > fs/xfs/libxfs/xfs_inode_fork.c | 23 +++++++++++++++++++++++ > fs/xfs/libxfs/xfs_inode_fork.h | 2 ++ > 2 files changed, 25 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c > index 0cf853d42d62..3a084aea8f85 100644 > --- a/fs/xfs/libxfs/xfs_inode_fork.c > +++ b/fs/xfs/libxfs/xfs_inode_fork.c > @@ -23,6 +23,7 @@ > #include "xfs_da_btree.h" > #include "xfs_dir2_priv.h" > #include "xfs_attr_leaf.h" > +#include "xfs_types.h" > > kmem_zone_t *xfs_ifork_zone; > > @@ -728,3 +729,25 @@ xfs_ifork_verify_local_attr( > > return 0; > } > + > +int > +xfs_iext_count_may_overflow( > + struct xfs_inode *ip, > + int whichfork, > + int nr_to_add) > +{ > + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); > + uint64_t max_exts; > + uint64_t nr_exts; > + > + if (whichfork == XFS_COW_FORK) > + return 0; > + > + max_exts = (whichfork == XFS_ATTR_FORK) ? MAXAEXTNUM : MAXEXTNUM; > + > + nr_exts = ifp->if_nextents + nr_to_add; > + if (nr_exts < ifp->if_nextents || nr_exts > max_exts) > + return -EFBIG; > + > + return 0; > +} > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h > index a4953e95c4f3..0beb8e2a00be 100644 > --- a/fs/xfs/libxfs/xfs_inode_fork.h > +++ b/fs/xfs/libxfs/xfs_inode_fork.h > @@ -172,5 +172,7 @@ extern void xfs_ifork_init_cow(struct xfs_inode *ip); > > int xfs_ifork_verify_local_data(struct xfs_inode *ip); > int xfs_ifork_verify_local_attr(struct xfs_inode *ip); > +int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork, > + int nr_to_add); > > #endif /* __XFS_INODE_FORK_H__ */ > -- > 2.28.0 >