From patchwork Wed Oct 10 00:10:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 10633415 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 55B155CAF for ; Wed, 10 Oct 2018 00:10:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 48CED29C80 for ; Wed, 10 Oct 2018 00:10:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4737129C85; Wed, 10 Oct 2018 00:10:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E7E3C29C8B for ; Wed, 10 Oct 2018 00:10:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726600AbeJJHaN (ORCPT ); Wed, 10 Oct 2018 03:30:13 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:50650 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725811AbeJJHaM (ORCPT ); Wed, 10 Oct 2018 03:30:12 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9A08ir7119775; Wed, 10 Oct 2018 00:10:43 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : from : to : cc : date : message-id : mime-version : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=EwpExZkig2pk5zdSUywkHCsBn4AvIvIdP/tZHlnRRak=; b=EKQXPSiA1kBBDN5FnnNjNOfG82n/5TMHQLfm+rSHzEyjKalDy3HjJj13G1o92f4xeDuA B20y4W90AlizGaV11meHzNAQd1wyoC9x5b8kbQxNPOBZbMnVi7bjeecIGYU56k/SIwla VSyhB5FUdXIjgWk1DMVKdp1Pk8exFH12LbInokoLzVGGXithUIL51dO8Qu38QqmIuF8K o5fnkhYNIratRaKfKU24Jb1xthoRibXG2s/mi5f3geJSAYCxu23AigP7rU4Lno5jFMAj yFpbJEo4moHapkvHJ/3QfdICbrcFCGm/wCDyLi+G0DkmhHYGXaYaWhnM2DCcpyTZpV0K XQ== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2130.oracle.com with ESMTP id 2mxmftrvfb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 10 Oct 2018 00:10:43 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w9A0Af7L024746 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 10 Oct 2018 00:10:41 GMT Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w9A0AetQ002669; Wed, 10 Oct 2018 00:10:40 GMT Received: from localhost (/10.159.249.114) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 10 Oct 2018 00:10:40 +0000 Subject: [PATCH v2 00/25] fs: fixes for serious clone/dedupe problems From: "Darrick J. Wong" To: david@fromorbit.com, darrick.wong@oracle.com Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com Date: Tue, 09 Oct 2018 17:10:38 -0700 Message-ID: <153913023835.32295.13962696655740190941.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9041 signatures=668706 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=733 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810100000 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi all, Dave, Eric, and I have been chasing a stale data exposure bug in the XFS reflink implementation, and tracked it down to reflink forgetting to do some of the file-extending activities that must happen for regular writes. We then started auditing the clone, dedupe, and copyfile code and realized that from a file contents perspective, clonerange isn't any different from a regular file write. Unfortunately, we also noticed that *unlike* a regular write, clonerange skips a ton of overflow checks, such as validating the ranges against s_maxbytes, MAX_NON_LFS, and RLIMIT_FSIZE. We also observed that cloning into a file did not strip security privileges (suid, capabilities) like a regular write would. I also noticed that xfs and ocfs2 need to dump the page cache before remapping blocks, not after. In fixing the range checking problems I also realized that both dedupe and copyfile tell userspace how much of the requested operation was acted upon. Since the range validation can shorten a clone request (or we can ENOSPC midway through), we might as well plumb the short operation reporting back through the VFS indirection code to userspace. So, here's the whole giant pile of patches[1] that fix all the problems. The patch "generic: test reflink side effects" recently sent to fstests exercises the fixes in this series. Tests are in [2]. --D [1] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=djwong-devel [2] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfstests-dev.git/log/?h=djwong-devel