From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750851AbWCBEE0 (ORCPT ); Wed, 1 Mar 2006 23:04:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750766AbWCBEE0 (ORCPT ); Wed, 1 Mar 2006 23:04:26 -0500 Received: from smtp.osdl.org ([65.172.181.4]:57306 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750851AbWCBEEZ (ORCPT ); Wed, 1 Mar 2006 23:04:25 -0500 Date: Wed, 1 Mar 2006 20:03:50 -0800 (PST) From: Linus Torvalds To: Michael Kerrisk cc: Janak Desai , akpm@osdl.org, ak@muc.de, hch@lst.de, paulus@samba.org, viro@ftp.linux.org.uk, linux-kernel@vger.kernel.org, michael.kerrisk@gmx.net Subject: Re: unhare() interface design questions and man page In-Reply-To: <19847.1141270261@www008.gmx.net> Message-ID: References: <43F8B05B.4090707@us.ibm.com> <19847.1141270261@www008.gmx.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2 Mar 2006, Michael Kerrisk wrote: > > >>>>> > > >>>>> That is, CLONE_FS, CLONE_FILES, and CLONE_VM *reverse* the > > >>>>> effects of the clone() flags of the same name, but CLONE_NEWNS > > >>>>> *has the same meaning* as the clone() flag of the same name. Well, if this is the only problem, who cares? CLONE_NEWNS itself is actually a reversal of clone flags: unlike the others, that tell to _share_ things that normally aren't shared across a fork(), CLONE_NEWNS does the opposite: it asks to unshare something that normally is shared. So the fact that it then acts not as a reversal when doing "unshare()" is actually consistent with the fact that it's a already a "unshare" event for clone() itself. > Do you have any further response on this point? > (There was none in your last message?) I personally don't think it's worth makign UNSHARE_NEWNS just because it's a flag that acts differently from the other CLONE_xxx flags. As to whether allow or not allow unknown unshare() flags, I don't think it's a huge deal either way. Right now we don't check the flags to "clone()" either, I think. Linus