Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751878AbaBMTUo (ORCPT ); Thu, 13 Feb 2014 14:20:44 -0500 Received: from mail-ve0-f175.google.com ([209.85.128.175]:53156 "EHLO mail-ve0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751824AbaBMTUn (ORCPT ); Thu, 13 Feb 2014 14:20:43 -0500 MIME-Version: 1.0 In-Reply-To: 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> Date: Thu, 13 Feb 2014 11:20:42 -0800 X-Google-Sender-Auth: tqN_RPXUXozk4C5BQd8exN5O-nM Message-ID: Subject: Re: [PATCH 00/13] cross rename v4 From: Linus Torvalds To: Miklos Szeredi Cc: David Howells , 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 10:56 AM, Miklos Szeredi wrote: > > Fair enough, that allows the thing to be listed, at least. > > What about creation? A new syscall? > > Removal? unlink(2)? > > Should stat(2) succeed with a new filetype? I think it had better work exactly like a special node (eg character device etc). I don't know about creation (yes, we might even fake it with mknod(), or just say that the only way to create them is as part of the union-fs), but removal and renaming should absolutely *not* be a new system call. That would be a disaster for any system admin, having to use special tools to edit the filesystem. Obviously when it is part of a union mount, whiteouts work differently - they must *not* show up in getdents, and you can't rename/remove a whiteout anywhere else. But that is obviously part of the union-fs, nor the low-level filesystem itself. 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/