From owner-freebsd-current@FreeBSD.ORG Thu Sep 30 17:46:29 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 955C51065673 for ; Thu, 30 Sep 2010 17:46:29 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-bw0-f54.google.com (mail-bw0-f54.google.com [209.85.214.54]) by mx1.freebsd.org (Postfix) with ESMTP id 1DC0C8FC1F for ; Thu, 30 Sep 2010 17:46:28 +0000 (UTC) Received: by bwz15 with SMTP id 15so2087127bwz.13 for ; Thu, 30 Sep 2010 10:46:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=Aib25OLq0z3MPdtY43gSpKb4IRHg6/dHsJ41V+674IE=; b=F9YJ3B60I5BPYCtKs3pTcKjKkqUOlLGChUAEw9eLqHOO6f98/3eEwuTpUhSSolPPAB WaJpgGjiQ1vu3fY9scmE36u4BnfLzCsKVBpXksM8Or8n+5fUi+DEIyr/RP12y/6a94Ss oFQKPzeM60MvnJ5cux8VPvnAF3dP+nROF7m/A= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:subject :references:in-reply-to:content-type:content-transfer-encoding; b=lSCgG2C5UFpdbJKp2hP08ZMA8/pBMdH6cGvP//B8w+WFcWyxopsgXnWTHGiEJGcy2m uqCXdAGi4kkiYwzY3PybZYd4nL7UkKGnUp4vlQo+EREH2WFA+tJWpmrJvQC23Ph026nd motRTuuFwigtG6vt1RGoXUGiEB1HdOOfy1dkM= Received: by 10.204.82.136 with SMTP id b8mr3055109bkl.38.1285868787932; Thu, 30 Sep 2010 10:46:27 -0700 (PDT) Received: from mavbook2.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id 24sm118677bkr.19.2010.09.30.10.46.26 (version=SSLv3 cipher=RC4-MD5); Thu, 30 Sep 2010 10:46:27 -0700 (PDT) Sender: Alexander Motin Message-ID: <4CA4CCE3.9060408@FreeBSD.org> Date: Thu, 30 Sep 2010 20:46:11 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20091212) MIME-Version: 1.0 To: Andriy Gapon , FreeBSD-Current References: <4CA3BD7C.9080306@feral.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Subject: Re: letting glabel recognise a media change X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Sep 2010 17:46:29 -0000 Andriy Gapon wrote: > on 30/09/2010 01:28 Matthew Jacob said the following: >> If something like that was in place, I assure you that things would start to use >> it very quickly. > > I am not sure about this. > Because, e.g. I don't see an easy way to know that media is changed in scsi_cd > driver. That is, without polling. I don't consider polling to be an easy way for > a number of reasons. SATA specification defines concept of Asynchronous Notification. It is already used by port multipliers to report about PHY events. It is also supposed to be used by CD drives to report media change. I haven't seen such devices yet, but hope they may appear sometimes. And even without AN support it would be nice to implement proper handling for SCSI "UA - media changed" errors within CAM. It still won't be perfect without using polling, but probably still something. -- Alexander Motin