Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936202AbcCQQfU (ORCPT ); Thu, 17 Mar 2016 12:35:20 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:38090 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754409AbcCQQfR (ORCPT ); Thu, 17 Mar 2016 12:35:17 -0400 Date: Thu, 17 Mar 2016 17:36:30 +0100 From: Miklos Szeredi To: Konstantin Khlebnikov Cc: linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, Alexander Viro , linux-kernel@vger.kernel.org Subject: Re: [PATCH] vfs: update atime using file->f_inode Message-ID: <20160317163630.GR8655@tucsk> References: <145424638614.10446.16013603987277558993.stgit@zurg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <145424638614.10446.16013603987277558993.stgit@zurg> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1442 Lines: 53 On Sun, Jan 31, 2016 at 04:19:46PM +0300, Konstantin Khlebnikov wrote: > This fixes some cases of missing atime update for overlayfs. Problem is it will update atime on lower layer, even if it's explicitly marked read-only. Which I think is a pretty bad breakage of assumptions. The following patch updates atime (untested) but only in the upper layer. Obviously it makes no sense to copy-up due to an atime update. Thanks, Miklos --- fs/overlayfs/inode.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -370,6 +370,27 @@ struct inode *ovl_d_select_inode(struct return d_backing_inode(realpath.dentry); } +static int ovl_update_time(struct inode *inode, struct timespec *ts, int flags) +{ + struct dentry *alias; + struct path upperpath; + + if (!(flags & S_ATIME)) + return 0; + + alias = d_find_any_alias(inode); + if (!alias) + return 0; + + ovl_path_upper(alias, &upperpath); + if (!upperpath.dentry) + return 0; + + touch_atime(&upperpath); + + return 0; +} + static const struct inode_operations ovl_file_inode_operations = { .setattr = ovl_setattr, .permission = ovl_permission, @@ -378,6 +399,7 @@ static const struct inode_operations ovl .getxattr = ovl_getxattr, .listxattr = ovl_listxattr, .removexattr = ovl_removexattr, + .update_time = ovl_update_time, }; static const struct inode_operations ovl_symlink_inode_operations = {