From patchwork Thu Dec 1 10:15:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miklos Szeredi X-Patchwork-Id: 9455733 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 51AAB60515 for ; Thu, 1 Dec 2016 10:15:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 41357284C6 for ; Thu, 1 Dec 2016 10:15:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 365CA284CE; Thu, 1 Dec 2016 10:15:54 +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 E2DE4284C6 for ; Thu, 1 Dec 2016 10:15:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756577AbcLAKPV (ORCPT ); Thu, 1 Dec 2016 05:15:21 -0500 Received: from mail-wj0-f170.google.com ([209.85.210.170]:33946 "EHLO mail-wj0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756460AbcLAKPR (ORCPT ); Thu, 1 Dec 2016 05:15:17 -0500 Received: by mail-wj0-f170.google.com with SMTP id mp19so200444659wjc.1 for ; Thu, 01 Dec 2016 02:15:16 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=D+HB+P3U2/sVqhiaT7yyYAWQ0mv8h4Ix2GnXSsnIY6A=; b=DiY6VNazXEyp/H6qzLsDx9ZVaGZIKGNTfIKccqDYR3crS31504mVJJ2GLrGb5gjjNV yFmykTtcX69cX+9vzNlYEaoHtIRCYrA7plsKyODWS1jbQCX6YOyTWc0W1vFMfv7CNNpY EsYUFoQVE767qnYwlr8gzVySqTirFm89nDkHt+7gXuQ6gCtskmajSlyl/sqOi+PwuyLx 0r69diA3glTNO9tZKoyZQoR3ND5NEasmNSRVSwyI/5xfFv4mr1qn1f2llYm/86IdGrwq vBfIKZD2pnXnVjZeZVIlLhdRWkDbkrY/xazthPOMMOaE2TdiGIBvMNamlE2vdK2pl704 geOA== X-Gm-Message-State: AKaTC02AuyAThWsqnqfYKtQAPtj1/IiOzwPFOE5s6uFr6t7c0+W3xrnorKqWO4skvJ3H6Ajk X-Received: by 10.194.87.230 with SMTP id bb6mr37356993wjb.163.1480587315582; Thu, 01 Dec 2016 02:15:15 -0800 (PST) Received: from veci.piliscsaba.szeredi.hu (pool-dsl-2c-0018.externet.hu. [217.173.44.24]) by smtp.gmail.com with ESMTPSA id ab10sm77218141wjc.45.2016.12.01.02.15.14 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Dec 2016 02:15:14 -0800 (PST) From: Miklos Szeredi To: Al Viro Cc: linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 7/8] ovl: intercept fsync Date: Thu, 1 Dec 2016 11:15:02 +0100 Message-Id: <1480587303-25088-8-git-send-email-mszeredi@redhat.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1480587303-25088-1-git-send-email-mszeredi@redhat.com> References: <1480587303-25088-1-git-send-email-mszeredi@redhat.com> 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 Fsync is really an inode operation (AFAICS) so a doing it on a O_RDONLY file descriptor should flush any data written through an O_WRONLY file descriptor for example. To make this work correctly in case the file is copied up after being opened for read intercept the fsync fop, similarly to read_iter and mmap. Signed-off-by: Miklos Szeredi --- fs/overlayfs/inode.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 210838f97777..d861aa7462c5 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -412,6 +412,24 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma) return file->f_op->mmap(file, vma); } +static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + int ret; + + if (likely(ovl_file_is_lower(file))) { + return OVL_CALL_REAL_FOP(file, + fsync(file, start, end, datasync)); + } + file = filp_clone_open(file); + if (IS_ERR(file)) + return PTR_ERR(file); + + ret = vfs_fsync_range(file, start, end, datasync); + fput(file); + + return ret; +} + static struct ovl_fops *ovl_fops_find(const struct file_operations *orig) { struct ovl_fops *ofop; @@ -455,9 +473,8 @@ static struct ovl_fops *ovl_fops_get(struct file *file) ofop->fops.read_iter = ovl_read_iter; if (orig->mmap) ofop->fops.mmap = ovl_mmap; - - /* These will need to be intercepted: */ - ofop->fops.fsync = orig->fsync; + if (orig->fsync) + ofop->fops.fsync = ovl_fsync; /* * These should be intercepted, but they are very unlikely to be