From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D848ECE596 for ; Thu, 10 Oct 2019 08:41:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1DF022248B for ; Thu, 10 Oct 2019 08:41:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570696904; bh=kjBBx1owjHoHOHK+PfnP7vwaB5MJ/Cp+vuwoeSfQum4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FET6y5uaUnj3e3cjft0z1ZKf2RV/IJKJn7aue6Tf/MgssIJ4izjM41hgGneuW4rvw fxOsmkYthMB0Qc/ZNneTdWfWGaIZ4pIMxW0VqdqtCw9laRr/3msEH+PDvIhepiMHzy NcKMTrY4SSMMr9e7aSYdFfB3C64izRfFLKigYtT8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388375AbfJJIlm (ORCPT ); Thu, 10 Oct 2019 04:41:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:46160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388383AbfJJIll (ORCPT ); Thu, 10 Oct 2019 04:41:41 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 888812054F; Thu, 10 Oct 2019 08:41:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570696901; bh=kjBBx1owjHoHOHK+PfnP7vwaB5MJ/Cp+vuwoeSfQum4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NYi+1K+i+QfW6NbtVQGi50s5uI5KdhlkmLeyXnvS+NWXyEapPFPmiezEWz7RNjBVB +Lrq0+uOVdrrLG7Lo9RwJB3vIgXcMRMn9aNFb1GtSeZp9jJSnV08u8HSYzx++ptKJ/ hTu1CHJVfccf0cynC/qNqn5ii0BAhcmYcA6IIYs8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chengguang Xu , Dominique Martinet , Sasha Levin Subject: [PATCH 5.3 095/148] 9p: avoid attaching writeback_fid on mmap with type PRIVATE Date: Thu, 10 Oct 2019 10:35:56 +0200 Message-Id: <20191010083617.043759883@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083609.660878383@linuxfoundation.org> References: <20191010083609.660878383@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chengguang Xu [ Upstream commit c87a37ebd40b889178664c2c09cc187334146292 ] Currently on mmap cache policy, we always attach writeback_fid whether mmap type is SHARED or PRIVATE. However, in the use case of kata-container which combines 9p(Guest OS) with overlayfs(Host OS), this behavior will trigger overlayfs' copy-up when excute command inside container. Link: http://lkml.kernel.org/r/20190820100325.10313-1-cgxu519@zoho.com.cn Signed-off-by: Chengguang Xu Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin --- fs/9p/vfs_file.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 4cc966a31cb37..fe7f0bd2048e4 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -513,6 +513,7 @@ v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma) v9inode = V9FS_I(inode); mutex_lock(&v9inode->v_mutex); if (!v9inode->writeback_fid && + (vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE)) { /* * clone a fid and add it to writeback_fid @@ -614,6 +615,8 @@ static void v9fs_mmap_vm_close(struct vm_area_struct *vma) (vma->vm_end - vma->vm_start - 1), }; + if (!(vma->vm_flags & VM_SHARED)) + return; p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma); -- 2.20.1