From patchwork Wed Oct 5 14:38:54 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adam Borowski X-Patchwork-Id: 9363005 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5C4566077E for ; Wed, 5 Oct 2016 14:39:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4E8B52865F for ; Wed, 5 Oct 2016 14:39:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4331228777; Wed, 5 Oct 2016 14:39:28 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham 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 898152865F for ; Wed, 5 Oct 2016 14:39:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753290AbcJEOjW (ORCPT ); Wed, 5 Oct 2016 10:39:22 -0400 Received: from tartarus.angband.pl ([89.206.35.136]:57236 "EHLO tartarus.angband.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752015AbcJEOjV (ORCPT ); Wed, 5 Oct 2016 10:39:21 -0400 X-Greylist: delayed 398 seconds by postgrey-1.27 at vger.kernel.org; Wed, 05 Oct 2016 10:39:21 EDT Received: from umbar.angband.pl ([2001:6a0:118::6]) by tartarus.angband.pl with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1brnLi-0002qX-I4; Wed, 05 Oct 2016 16:39:14 +0200 Received: from kilobyte by umbar.angband.pl with local (Exim 4.87) (envelope-from ) id 1brnLi-0004T8-4C; Wed, 05 Oct 2016 16:39:10 +0200 From: Adam Borowski To: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Adam Borowski Date: Wed, 5 Oct 2016 16:38:54 +0200 Message-Id: <20161005143854.17133-1-kilobyte@angband.pl> X-Mailer: git-send-email 2.9.3 X-SA-Exim-Connect-IP: 2001:6a0:118::6 X-SA-Exim-Mail-From: kilobyte@angband.pl Subject: [PATCH resend] vfs: allow FILE_EXTENT_SAME (dedupe_file_range) on a file opened ro X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on tartarus.angband.pl) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Instead of checking the mode of the file descriptor, let's check whether it could have been opened rw. This allows fixing intermittent exec failures when deduping a live system: anyone trying to exec a file currently being deduped gets ETXTBSY. Issuing this ioctl on a ro file was already allowed for root/cap. Tested on btrfs and not-yet-merged xfs, as only them implement this ioctl. Signed-off-by: Adam Borowski Reviewed-by: Mark Fasheh --- fs/read_write.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/read_write.c b/fs/read_write.c index 66215a7..8ea5297 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1741,7 +1741,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same) if (info->reserved) { info->status = -EINVAL; - } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) { + } else if (!(is_admin || !inode_permission(dst, MAY_WRITE))) { info->status = -EINVAL; } else if (file->f_path.mnt != dst_file->f_path.mnt) { info->status = -EXDEV;