From patchwork Wed Oct 17 22:44:36 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: 10646193 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 A0AFF1508 for ; Wed, 17 Oct 2018 22:44:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 94F61288C7 for ; Wed, 17 Oct 2018 22:44:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 88C0F288FD; Wed, 17 Oct 2018 22:44:48 +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 4A5D6288CA for ; Wed, 17 Oct 2018 22:44:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727539AbeJRGmg (ORCPT ); Thu, 18 Oct 2018 02:42:36 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:54736 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726853AbeJRGmg (ORCPT ); Thu, 18 Oct 2018 02:42:36 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9HMi1fu189345; Wed, 17 Oct 2018 22:44:39 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : from : to : cc : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=6r7g0KcDO4x0ZJm4RBSdxfhsKMbYQWElnIgn2PkV3NQ=; b=FNGNbPNzL+PSO3MkE92LNJ6BtsRlRfm0F4OuajFlHs2UrqEJwp2HmmIoaIZWJJfsNp1I LzerlI9NsrQ2ZLEtWN2TDu5V3H1XIQkRj9vgTUQ/fQ+m/6MkyJyiS56ugsuWffnE3jvk NKzTHh05uhSDAwwLjvbLhSiBN6Ac4EfIEEvRGqEi4iQ6Q9Hw23krKFnpeCu6hGTAnFTt uq1G4AzgJj5E/TdA8YVxXCL3jPBZvl9DixrhHbd6TlS41penHakBxmDS8wMA4026fItr znrg4P5iRxvW/6zleC9GA+AkNmcNg1pr7/FBzVI0zhtzqLvO96PB8r6PuFD+Ew6Z6PXb Tg== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2n39brhnyy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Oct 2018 22:44:39 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w9HMiccJ008088 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Oct 2018 22:44:38 GMT Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w9HMib1w031348; Wed, 17 Oct 2018 22:44:37 GMT Received: from localhost (/10.159.132.177) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 17 Oct 2018 15:44:37 -0700 Subject: [PATCH 03/29] vfs: exit early from zero length remap operations 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, Christoph Hellwig , ocfs2-devel@oss.oracle.com Date: Wed, 17 Oct 2018 15:44:36 -0700 Message-ID: <153981627600.5568.16857314567554014035.stgit@magnolia> In-Reply-To: <153981625504.5568.2708520119290577378.stgit@magnolia> References: <153981625504.5568.2708520119290577378.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9049 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=710 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810170188 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 From: Darrick J. Wong If a remap caller asks us to remap to the source file's EOF and the source file length leaves us with a zero byte request, exit early. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/read_write.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/read_write.c b/fs/read_write.c index d6e8e242a15f..2456da3f8a41 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1748,6 +1748,8 @@ int vfs_clone_file_prep(struct file *file_in, loff_t pos_in, if (pos_in > isize) return -EINVAL; *len = isize - pos_in; + if (*len == 0) + return 0; } /* Check that we don't violate system file offset limits. */