From patchwork Thu Oct 11 04:12:16 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: 10635699 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 2A763933 for ; Thu, 11 Oct 2018 04:12:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 13ABC2A612 for ; Thu, 11 Oct 2018 04:12:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 077D52A63B; Thu, 11 Oct 2018 04:12:31 +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 B3C122A612 for ; Thu, 11 Oct 2018 04:12:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726873AbeJKLht (ORCPT ); Thu, 11 Oct 2018 07:37:49 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:59460 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726047AbeJKLhs (ORCPT ); Thu, 11 Oct 2018 07:37:48 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9B497Xc052721; Thu, 11 Oct 2018 04:12:21 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=iq6/QjsgR4VqKWM0XL5jv+SMSL3vQSq7f9TjIGwxkRU=; b=QMdO5ZoFNPXJ1oWRCgXgNq1EpWdux7KL9DLmVY30L7VzD9nGUW5UBG8mkFgThob4esGW Im0PWPhr2Vw0hWaAwDXgZV97wpiBkCVkfcUMFphlZfWNfjbLO5kqup07bgYTN+oJKkf0 ueGZ/WuSlsFOrK3uTJZIemzZu4x5CgsjZtYw2apvIdXN8QMQ7nMtr9AUH+NdCcZBsh1W 4n8OfqI/KE+NfU5pzYjfpJTemX2EDU7rHsqWbEBg0eO+8GsxQuGBvPMaxMUEWO99nTHd RieppcNTlzXnm9tIo2TaYWZ1jNWuCjcwDjRtEu8B6jDxIdsjOgq94Jq6u0//07CLlVsk MA== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by aserp2120.oracle.com with ESMTP id 2mxn0q9dr3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Oct 2018 04:12:21 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w9B4CJF0010021 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Oct 2018 04:12:20 GMT Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w9B4CIpb029404; Thu, 11 Oct 2018 04:12:18 GMT Received: from localhost (/10.159.132.249) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 11 Oct 2018 04:12:18 +0000 Subject: [PATCH v3 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: Wed, 10 Oct 2018 21:12:16 -0700 Message-ID: <153923113649.5546.9840926895953408273.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9042 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=788 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810110039 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. This branch is against 4.19-rc7 with Dave Chinner's XFS for-next branch. 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