Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765314AbXJFUZI (ORCPT ); Sat, 6 Oct 2007 16:25:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763972AbXJFUY5 (ORCPT ); Sat, 6 Oct 2007 16:24:57 -0400 Received: from sovereign.computergmbh.de ([85.214.69.204]:36485 "EHLO sovereign.computergmbh.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761393AbXJFUY4 (ORCPT ); Sat, 6 Oct 2007 16:24:56 -0400 Date: Sat, 6 Oct 2007 22:24:55 +0200 (CEST) From: Jan Engelhardt To: Hugh Dickins cc: Guennadi Liakhovetski , linux-kernel@vger.kernel.org Subject: Re: tmpfs disabled in .config but in /proc/filesystems In-Reply-To: Message-ID: References: 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 Content-Length: 1494 Lines: 35 On Oct 5 2007 21:49, Hugh Dickins wrote: >> > > $ zcat /proc/config.gz | grep TMPFS >> > > # CONFIG_TMPFS is not set >> > > $ grep tmpfs /proc/filesystems >> > > nodev tmpfs >> > >> > tmpfs (mm/shmem.c) is used by the kernel to support shared memory >> > of various kinds even when CONFIG_TMPFS is not set. But only when >> > CONFIG_TMPFS=y can users mount a tmpfs as a fully capable filesystem. >> > Confusing, yes: sorry for putting the fear of craziness upon you. >> >> Oops, sorry, now I remember reading about this... As a matter of fact, the >> presence in /proc/filesystem - was it a deliberate decision, or >> technically preferrable or a mistake? > >d) None of the above! > >I've never really thought about it, but I think it's simply a natural >side-effect of the register_filesystem and vfs_kern_mount it has to >do in order to get the services it needs from the VFS. Well you could add a new flag to the file_system_type struct ("FS_INVISIBLE") that is set when this or that condition (like TMPFS=n) is in effect. It would be just cosmetic though. You can't mount a lot of other filesystems like the hidden bdev, pipefs or sockfs (it would really be nice to explore them with ls!), yet they are not invisible either right now. - 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/