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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 1488CECE587 for ; Tue, 1 Oct 2019 16:54:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D086F21855 for ; Tue, 1 Oct 2019 16:54:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948842; bh=ygCTvRpC/E8gPrphJSMIGoYq+fQYGL1AUKhHOHVrbMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VZgNMUGcztOdQ0TezcfVyiu9hQxJX9g4LawMdIEvgjRIpByjDnEUiHH5Xyv8KZKKG gVUNfivJRJ2kkQZNe3DiBzM5OlUBCaSY7024reY0y9RAZDQ1GYBRg4Ke+Tm/PwvEhs 1VfFPF0AuHtvW4yC4o3iu8ZrHIjk490bWzb4unTw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728014AbfJAQyC (ORCPT ); Tue, 1 Oct 2019 12:54:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:55348 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732552AbfJAQnS (ORCPT ); Tue, 1 Oct 2019 12:43:18 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 30EFA21906; Tue, 1 Oct 2019 16:43:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948197; bh=ygCTvRpC/E8gPrphJSMIGoYq+fQYGL1AUKhHOHVrbMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QAkwi4C/IodnsqpB77yPzgi+rcaMXkyn4Sv+fe6eWA7S/Rana0YGuyq9p+XcRd0yt LZbHHABTlK0d4VA2gq7qY+kq6lnySQMULHgMGZSE/ktRI9LmLXzJLKCNVNACKzNA/j tZzxryRu1qSZLQW7wdlNvhur/WGLcygyKbLe40MU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Chengguang Xu , Dominique Martinet , Sasha Levin , v9fs-developer@lists.sourceforge.net Subject: [PATCH AUTOSEL 4.19 05/43] 9p: avoid attaching writeback_fid on mmap with type PRIVATE Date: Tue, 1 Oct 2019 12:42:33 -0400 Message-Id: <20191001164311.15993-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164311.15993-1-sashal@kernel.org> References: <20191001164311.15993-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 05454a7e22dc2..550d0b169d7c2 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -528,6 +528,7 @@ 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 @@ -629,6 +630,8 @@ 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