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: 10627191 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 5FDD015A6 for ; Fri, 5 Oct 2018 00:45:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5014628F4F for ; Fri, 5 Oct 2018 00:45:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4442928F7A; Fri, 5 Oct 2018 00:45:59 +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=-5.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from userp2130.oracle.com (userp2130.oracle.com [156.151.31.86]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D5F3828F4F for ; Fri, 5 Oct 2018 00:45:58 +0000 (UTC) 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 w950iVEN029876; Fri, 5 Oct 2018 00:45:30 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : date : message-id : mime-version : cc : subject : list-id : list-unsubscribe : list-archive : list-post : list-help : list-subscribe : content-type : content-transfer-encoding : sender; s=corp-2018-07-02; bh=7ELt+41qFNt+HaEzrVdAmlqhAZFGhKVpipxsr5JDdSE=; b=t0ylebhpWqUZrAPiCpv+PD43zsBmXEbVD5STi6viqkFVuloXsuSVu/psafMQYY7fPiK/ uxsO7QE3rlC4c40UU0rZ4LR8dSxGcLCcXi9FzXLS6npoiFKsPeMok6EeH+N4Gd/xKeJ9 KE2wPuvST+jPUwrlkz61KHKD+oKMCfOUpZgcltNnzzYDvONdWTFfhtQp+BMn25wmrhSn FMddATNhzBxTBCyePFbYouq63EYFj6pWyh1RAjz5Ur6b0plpEXerYUaaadspj6+hZMJc 25wcit9yPGGPUuhjImT9x6gPIjuFNVV7YZNMrT3+7jUMmZAiTCh6aatQRSHjVvJaG92b NA== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2130.oracle.com with ESMTP id 2mt0tu7ng1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 05 Oct 2018 00:45:30 +0000 Received: from oss.oracle.com (oss-old-reserved.oracle.com [137.254.22.2]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w950jMFL012604 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 5 Oct 2018 00:45:22 GMT Received: from localhost ([127.0.0.1] helo=lb-oss.oracle.com) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1g8EF8-0004hx-Bw; Thu, 04 Oct 2018 17:45:22 -0700 Received: from aserv0021.oracle.com ([141.146.126.233]) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1g8EEO-0004et-NB for ocfs2-devel@oss.oracle.com; Thu, 04 Oct 2018 17:44:36 -0700 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 From: "Darrick J. Wong" To: david@fromorbit.com, darrick.wong@oracle.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 Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com, linux-btrfs@vger.kernel.org, sandeen@redhat.com Subject: [Ocfs2-devel] [PATCH 00/15] fs: fixes for serious clone/dedupe problems X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810050006 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