From patchwork Fri Oct 5 00:44:34 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: 10627129 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 733881926 for ; Fri, 5 Oct 2018 00:44:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 65EAE28F4F for ; Fri, 5 Oct 2018 00:44:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4FDE228F9D; Fri, 5 Oct 2018 00:44:45 +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 027DD28F7A for ; Fri, 5 Oct 2018 00:44:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726795AbeJEHkt (ORCPT ); Fri, 5 Oct 2018 03:40:49 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:51296 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726073AbeJEHkt (ORCPT ); Fri, 5 Oct 2018 03:40:49 -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 w950iJKF046870; Fri, 5 Oct 2018 00:44:37 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=dkT+nJtZjz4UJ5PfuoWEJOhZpIYJXNMhY9tesisim7H78azhqEnNq0+WVQ5H6fuMU/mx y2Jc5V2FprUBMSDN8vhyYr+Y9NnGNxbst+C8MbN5/ZsN7RJhc0Dcy+4lEUijvWIb7aLe FLYTrxBdSpCvB+ty7V8Lt53+KsIUsXga0btImBi/cl5cSYAb1Z51TF86rcrVBOBsEuXl 9dvrUw8DuOkB3CMoiKtFIDyvTaMy2m1ZL4/wMu/P8QvzS7N/jDqBT4I0HKMUdSJW45Wd opi3eG2AxASvULvktQjDfUKtpoZCEvQRDznulVtzFiEPCTjbj1BSZ3TukzZK8MxZIYgW Qg== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by aserp2120.oracle.com with ESMTP id 2mt1bqfkte-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 05 Oct 2018 00:44:37 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w950iaD3003150 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 5 Oct 2018 00:44:36 GMT Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w950iZHc014162; Fri, 5 Oct 2018 00:44:35 GMT Received: from localhost (/10.159.229.198) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 04 Oct 2018 17:44:35 -0700 Subject: [PATCH 00/15] fs: fixes for serious clone/dedupe problems From: "Darrick J. Wong" To: david@fromorbit.com, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, ocfs2-devel@oss.oracle.com, sandeen@redhat.com Date: Thu, 04 Oct 2018 17:44:34 -0700 Message-ID: <153870027422.29072.7433543674436957232.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9036 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=778 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810050006 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@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