From owner-freebsd-hackers@FreeBSD.ORG Wed Apr 23 19:25:30 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A6EC1106566B; Wed, 23 Apr 2008 19:25:30 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from hosted.kievnet.com (hosted.kievnet.com [193.138.144.10]) by mx1.freebsd.org (Postfix) with ESMTP id 4D7258FC1A; Wed, 23 Apr 2008 19:25:30 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from localhost ([127.0.0.1] helo=edge.pp.kiev.ua) by hosted.kievnet.com with esmtpa (Exim 4.62) (envelope-from ) id 1Jokau-000OjF-Ju; Wed, 23 Apr 2008 22:25:28 +0300 Message-ID: <480F8D23.9040005@icyb.net.ua> Date: Wed, 23 Apr 2008 22:25:23 +0300 From: Andriy Gapon User-Agent: Thunderbird 2.0.0.12 (X11/20080320) MIME-Version: 1.0 To: John Baldwin References: <480E4269.2090604@icyb.net.ua> <200804230955.10390.jhb@freebsd.org> In-Reply-To: <200804230955.10390.jhb@freebsd.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org Subject: Re: devctl (alike?) for devfs X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Apr 2008 19:25:30 -0000 on 23/04/2008 16:55 John Baldwin said the following: > On Tuesday 22 April 2008 03:54:17 pm Andriy Gapon wrote: >> Maybe this is a crazy idea or maybe we already have something like this. >> Is it possible to get notifications about changes in devfs - appearance >> and disappearance of devices (in devfs sense of the word)? >> devctl currently notifies about real (hardware) devices handled by >> device drivers and some notifications about hardware/driver events. >> But what if I want to automatically run some action if >> /dev/ufs/magic-label appears? >> Or if I want to monitor appearance and disappearance of ad* and da* >> devices (without having to monitor low level drivers like umass)? > > You would just need to add new hooks to devfs to feed events to devctl when > devices come and go. Other non-new-bus things like ifnet's already do this, > so there is precedent. > Thank you! This sounds like something rather simple, I'll try to create a patch. I think it would be a good idea to include "dev/" prefix in device name, so that devfs device is not confused with "driver device" (e.g. dev/umass0 vs umass0). -- Andriy Gapon