From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759035Ab3HMUPl (ORCPT ); Tue, 13 Aug 2013 16:15:41 -0400 Received: from moutng.kundenserver.de ([212.227.126.187]:59305 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759059Ab3HMUP1 (ORCPT ); Tue, 13 Aug 2013 16:15:27 -0400 From: Arnd Bergmann To: Bob Smith Subject: Re: [PATCH 001/001] CHAR DRIVERS: a simple device to give daemons a /sys-like interface Date: Tue, 13 Aug 2013 22:15:10 +0200 User-Agent: KMail/1.12.2 (Linux/3.8.0-22-generic; KDE/4.3.2; x86_64; ; ) Cc: "Greg Kroah-Hartman" , linux-kernel@vger.kernel.org References: <20130804231958.GA25418@kroah.com> <201308102343.11147.arnd@arndb.de> <5206B994.9050603@linuxtoys.org> In-Reply-To: <5206B994.9050603@linuxtoys.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201308132215.11178.arnd@arndb.de> X-Provags-ID: V02:K0:yqscGewoDACa7x55YftMXdTlAhEQUfU9EDZ0vZv10lQ Otl3hRKk8xHxm/vep4igALQmoKOIz/D/hMT9jZojcJne6hUMdw cG9XRPuFqE1yreDA+361+MDg3Lm8fqR6VUoZD2YRElBhBf9OtM ybmIYb1fP8bbojuRuYuhViYte61Cy0WIsdC00yhR8JL42ngMRZ QxP5SD5FZYlAoVRtjpUdWA10K+EQCA0BSL0jybsIc30qeg5yPO dtxRNtKbDPs90f21/OcqoUVKuekgrBma4KvMBFB9bkRRfsMtq2 AVyssO3QdPVU2aU/gmoUKv7jUpzF+niAuxX7xIbbEadlsOpBoF +9iTDN4fwGsuH4bcsJdA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 11 August 2013, Bob Smith wrote: > Arnd Bergmann wrote: > >> GOAL > >> The goal of this patch was to make it possible to configure > >> daemons using simple file IO. The litmus test for this is > >> that commands like these should be possible > >> cat < /var/daemons/wpa_supplicant/use_channel > >> echo 5 >/var/daemons/wpa_supplicant/use_channel > > > If you want to have that behavior, I think the best way to > > do it would be new file system that combines aspects of > > tmpfs and debugfs, letting users with write access to the > > mount point (or a directory under it) create subdirectories > > and files using regular unix permission handling. You would > > then always use the file_operations that you defined for your > > chardev but use that with inode_operations similar to tmpfs. > > THANKS! It would still be a kernel patch and still require > root to set up but so would FUSE and your approach might be > much lighter weight. Correct. Of course the only need for root access is to set up the fstab entry for the file system, which is not all that different from allowing fuse user mounts. Arnd