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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 B0AAFC433E2 for ; Fri, 28 Aug 2020 09:11:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4453520776 for ; Fri, 28 Aug 2020 09:11:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=crudebyte.com header.i=@crudebyte.com header.b="TFGghUCw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728555AbgH1JLd (ORCPT ); Fri, 28 Aug 2020 05:11:33 -0400 Received: from lizzy.crudebyte.com ([91.194.90.13]:52113 "EHLO lizzy.crudebyte.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728760AbgH1JL3 (ORCPT ); Fri, 28 Aug 2020 05:11:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=lizzy; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Content-ID:Content-Description; bh=TDjLhUMi2f57nIRf5nnT9ajtcLeHRqoCM4ISNW9naMs=; b=TFGghUCwnn9J3fRNyyGbFtuXQt +yCRqhHZjz67Kzda68uYpMXnNrlJrh03uHFri0le6SMRisECT/pmMEkXhVqSAOLCv9w6+C+otcWN2 4N/3i0XtP6dCEEbToaHmJncub1YYgU2s4+4UXERijbsPcxGDApPZyurs2rqMzVfTgSqEdSut5JHXm mng98ToRK7OniYY+XMS1ChoiY5VnGONOeBvWV3Me1+aXNtAxnmqM8lm24hmjyCKtHH1UkdNzdwZZN lG8HhcvtlpK46P5RQ3EgG592uzhwapKKC2ux5xngg/+cqNfuyFxLkLJ6BAN/ptN4/kt/i9LbwilyM gLwubpig==; From: Christian Schoenebeck To: "Dr. David Alan Gilbert" , Miklos Szeredi Cc: Al Viro , "Theodore Y. Ts'o" , Frank van der Linden , Dave Chinner , Greg Kurz , linux-fsdevel@vger.kernel.org, Stefan Hajnoczi , Miklos Szeredi , Vivek Goyal , Giuseppe Scrivano , Daniel J Walsh , Chirantan Ekbote Subject: Re: file forks vs. xattr (was: xattr names for unprivileged stacking?) Date: Fri, 28 Aug 2020 11:11:15 +0200 Message-ID: <11755866.l6z0jNX47O@silver> In-Reply-To: <20200827162935.GC2837@work-vm> References: <20200824222924.GF199705@mit.edu> <20200827144452.GA1236603@ZenIV.linux.org.uk> <20200827162935.GC2837@work-vm> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Donnerstag, 27. August 2020 16:44:52 CEST Al Viro wrote: > > No matter which delimiter you'd choose, something will break. It is just > > about how much will it break und how likely it'll be in practice, not if. > ... which means NAK. We don't break userland without very good reasons and > support for anyone's pet feature is not one of those. It's as simple as > that. > > > If you are concerned about not breaking anything: keep forks disabled. > > s/disabled/out of tree/ > > One general note: the arguments along the lines of "don't enable that, > then" are either ignorant or actively dishonest; it really doesn't work > that way, as we'd learnt quite a few times by now. There's no such > thing as "optional feature" - *any* feature, no matter how useless, > might end up a dependency (no matter how needless) of something that > would force distros to enable it. We'd been down that road too many > times to keep pretending that it doesn't happen. Well, it could be an option per mounted fs, but I know -> NAK. On Donnerstag, 27. August 2020 18:29:35 CEST Dr. David Alan Gilbert wrote: > * Al Viro (viro@zeniv.linux.org.uk) wrote: > > On Thu, Aug 27, 2020 at 04:23:24PM +0200, Christian Schoenebeck wrote: > > > Be invited for making better suggestions. But one thing please: don't > > > start > > > getting offending. > > > > > > No matter which delimiter you'd choose, something will break. It is just > > > about how much will it break und how likely it'll be in practice, not > > > if.> > > ... which means NAK. We don't break userland without very good reasons > > and > > support for anyone's pet feature is not one of those. It's as simple as > > that. > > I'm curious how much people expect to use these forks from existing > programs - do people expect to be able to do something and edit a fork > using their favorite editor or cat/grep/etc them? Built-in path resolution would be nice, but it won't be a show stopper for such common utils if not. For instance on Solaris there is: runat ... which works something like fchdir(); execv(); you loose some flexibility, but in practice still OK. > I say that because if they do, then having a special syscall to open > the fork wont fly; and while I agree that any form of suffix is a lost > cause, I wonder what else is possible (although if it wasn't for the > internal difficulties, I do have a soft spot for things that look like > both files and directories showing the forks; but I realise I'm weird > there). It seems to be both a file & dir feature on all systems that have that concept. So people would expect it for dirs on Linux as well. Best regards, Christian Schoenebeck