Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752039AbaBMTcf (ORCPT ); Thu, 13 Feb 2014 14:32:35 -0500 Received: from mail-vb0-f41.google.com ([209.85.212.41]:46452 "EHLO mail-vb0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751512AbaBMTcc (ORCPT ); Thu, 13 Feb 2014 14:32:32 -0500 MIME-Version: 1.0 In-Reply-To: <16729.1392318161@warthog.procyon.org.uk> References: <1391791751-2533-1-git-send-email-miklos@szeredi.hu> <19258.1392306854@warthog.procyon.org.uk> <20140213162534.GB4026@tucsk.piliscsaba.szeredi.hu> <20106.1392309770@warthog.procyon.org.uk> <16729.1392318161@warthog.procyon.org.uk> Date: Thu, 13 Feb 2014 11:32:31 -0800 X-Google-Sender-Auth: Tsp22TYAJXLLZPBdiGGZQPMPA84 Message-ID: Subject: Re: [PATCH 00/13] cross rename v4 From: Linus Torvalds To: David Howells Cc: Miklos Szeredi , Al Viro , Linux-Fsdevel , Kernel Mailing List , Bruce Fields , Christoph Hellwig , Andrew Morton , Zach Brown , Jan Kara , Andy Lutomirski , "mszeredi@suse.cz" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 13, 2014 at 11:02 AM, David Howells wrote: > > Whilst that does seem reasonable, what about all the other software that > iterates over a directory? Some of that is surely not going to know about > DT_WHT. So? Remeber: whiteout entries do not exist "normally". No normal apps should care or see them, since the whole and only point of them is when they are part of a union mount (in which case they are not visible). So the "how do you see whiteouts" is really only about the raw filesystem mount when *not* in the normal place. IOW, it's not like these guys are going to show up in users home directories etc. It's more like a special device node than a file - we need to care about some basic system management interfaces, not about "random apps". So "coreutils" is the primary user, although I guess a few IT people would prefer for things like Nautilus etc random file managers to be able to show them nicely too. But if they show up as an icon with a question mark on them or whatever, that's really not a big deal either. Sure, maybe they'll look odd in some graphical file chooser *if* somebody makes them show up, but I think creation of a whiteout - if we allow it at all outside of the union mount itself - should be a root-only thing (the same way mknod is) so quite frankly, it falls under "filesystem corruption makes my directory listings look odd - cry me a river". (I do think we should allow creation - but for root only - for management and testing purposes, but I really think it's a secondary issue, and I do think we should literally use "mknod()" - either with a new S_IFWHT or even just making use of existing S_IFCHR just so you could use the user-space "mknod" to create it with some magic major/minor combination. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/