From patchwork Tue Oct 16 03:10:23 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: 10642735 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 1426E3B73 for ; Tue, 16 Oct 2018 03:10:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0427E28F41 for ; Tue, 16 Oct 2018 03:10:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ECB0B2989B; Tue, 16 Oct 2018 03:10:32 +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 ACFC729883 for ; Tue, 16 Oct 2018 03:10:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727189AbeJPK6l (ORCPT ); Tue, 16 Oct 2018 06:58:41 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:48610 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727007AbeJPK6k (ORCPT ); Tue, 16 Oct 2018 06:58:40 -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 w9G38V3G053356; Tue, 16 Oct 2018 03:10:26 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=9TmCiNqyohhxt1dJj5u/Q03E/B3TZZ5o2UAiPujWx+4=; b=UWnzf5OetYhC/N6GwSnj1SwvwpGgZ0AFuFI2wZpc6uC4WTdAGlH7iw5f6ZRhkPEODcqv 3ERpdeuEP+L7K4svdepRObSCSAY/7fGo8TBTHmXfT4LH0maD8DtSDjdifuccoelVV3o8 jnoWlx+PAJnPwmYyXkDTfQkoWuEZczQxUsGiA0VErwK8tfqx5WcEtr2RRSV0hXx74h2m 9C3yAL9G/fO8UxJwVLqwzawzA3z1k15XoLr1RL4w8m7YXk3VWCbe8rarzCQV56obsRoc W1crIkRzCw8lWOxJYdJu2Z+60xPpdc19vh1015s+ZuYO9FTdiK+43tbrZ7h9vN4YXMTi Qg== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by aserp2120.oracle.com with ESMTP id 2n38npwuv7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 16 Oct 2018 03:10:26 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w9G3APWh028429 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 16 Oct 2018 03:10:25 GMT Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w9G3APO0002366; Tue, 16 Oct 2018 03:10:25 GMT Received: from localhost (/10.159.227.150) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 15 Oct 2018 20:10:25 -0700 Subject: [PATCH 04/26] 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, ocfs2-devel@oss.oracle.com Date: Mon, 15 Oct 2018 20:10:23 -0700 Message-ID: <153965942391.1256.1491987046439132016.stgit@magnolia> In-Reply-To: <153965939489.1256.7400115244528045860.stgit@magnolia> References: <153965939489.1256.7400115244528045860.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9047 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=544 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810160026 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 has zero bytes, 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. */