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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 49C63C33CA9 for ; Mon, 13 Jan 2020 20:55:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A8A92187F for ; Mon, 13 Jan 2020 20:55:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (3072-bit key) header.d=samba.org header.i=@samba.org header.b="ZyawoKgB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726494AbgAMUzL (ORCPT ); Mon, 13 Jan 2020 15:55:11 -0500 Received: from hr2.samba.org ([144.76.82.148]:49934 "EHLO hr2.samba.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbgAMUzL (ORCPT ); Mon, 13 Jan 2020 15:55:11 -0500 X-Greylist: delayed 1132 seconds by postgrey-1.27 at vger.kernel.org; Mon, 13 Jan 2020 15:55:10 EST DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=samba.org; s=42; h=Message-ID:Cc:To:From:Date; bh=JNKUuHInooF9ZI3fIFoHcMxkLm77ZEkAj3bulBvDOQE=; b=ZyawoKgBGqgc9wfBvamZTettCB FfagFfjTRczYIJAo1y5ZOcioVTbSKZ6FmwfoDxu7ui7sXRQ3WoWbAof3MUj5wTnlspl59KmOLvR5N 7UKgofrhgmqutPhUyxZREe8VwMZzLv5/9SDd761M7CeYogMbVUAk7v/SB495dLqJeZFp+t4CBPfc4 PjEkbSOlVRiOyhkd1ddKrXsPwmutgd+ze9JNhgIXRUCaekzPb948JhI8r791gAzbGN2qWacDjV6x9 Im9Z76Tp0s56gDihN9tm8B7WN7lDtwiu6/jxX7KJZlhMoOK1UimpkU2fAKdA782wZePiCSb8+h8mQ hg0uHzCA71vbsosGAZCG8rPkK2s/spH5GoM6KrfbHXd67D8AQ2FqNYCLpnOCfX+wUMQUgboFLV6xD PQTPbmLvBYy4EMY1MzjFmgnK8KyzT1wO5IgRkued5SftXQx1G9FAc0ZYnG4F1O1hPnfe48aKBUCbz pCdiL0QBmKkKPm5EyNQCiteT; Received: from [127.0.0.2] (localhost [127.0.0.1]) by hr2.samba.org with esmtpsa (TLS1.3:ECDHE_RSA_CHACHA20_POLY1305:256) (Exim) id 1ir6Rc-0002NT-P4; Mon, 13 Jan 2020 20:36:17 +0000 Date: Mon, 13 Jan 2020 12:36:13 -0800 From: Jeremy Allison To: Andreas Dilger Cc: Steve French , CIFS , Boris Protopopov , samba-technical , David Howells , linux-fsdevel Subject: Re: [PATCH] Add support for setting owner info, dos attributes, and create time Message-ID: <20200113203613.GA111855@jra4> Reply-To: Jeremy Allison References: <20191219165250.2875-1-bprotopopov@hotmail.com> <780DD595-1F92-4C34-A323-BB32748E5D07@dilger.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <780DD595-1F92-4C34-A323-BB32748E5D07@dilger.ca> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org On Mon, Jan 13, 2020 at 01:26:39PM -0700, Andreas Dilger via samba-technical wrote: > On Jan 9, 2020, at 12:10 PM, Steve French wrote: > > > > One loosely related question ... > > > > Your patch adds the ability to set creation time (birth time) which > > can be useful for backup/restore cases, but doesn't address the other > > hole in Linux (the inability to restore a files ctime). > > > > In Linux the ability to set timestamps seems quite limited (utimes > > only allows setting mtime and atime). > > The whole point of not being able to change ctime and btime as a regular > user is so that it is possible to determine when a file was actually > created on the filesystem and last modified. That is often useful for > debugging or forensics reasons. > > I think if this is something that SMB/CIFS wants to do, it should save > these attributes into an xattr of its own (e.g. user.dos or whatever), > rather than using the ctime and btime(crtime) fields in the filesystem. FYI, we (Samba) already do this for create time to store/fetch it on systems and filesystems that don't store a create time. It's easy to add extra info here.