From owner-freebsd-scsi@FreeBSD.ORG Wed May 26 18:44:59 2010 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D4B17106566C for ; Wed, 26 May 2010 18:44:59 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 5FC0E8FC19 for ; Wed, 26 May 2010 18:44:59 +0000 (UTC) Received: by fxm17 with SMTP id 17so2147178fxm.13 for ; Wed, 26 May 2010 11:44:58 -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:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=yAsS6LwF92Dg0Eb2EDWq9rk2rEulfuR7Vzv+TyF/3eA=; b=blpIYzfz4jKUiOORYmKbVj5xKSWkdFQVf3j6bWVcRYV9p779pV28+AcfpurtUhfWaa kVfXtZcWm323vBs1rQaWcQeGjiqSy9w8NChVBMp5Xr10VzN3v0LG2fBcIM6Qe1huIVq2 385C8LgIzwiPNhX0n9YOvyoSD1JWnr2jpvlY4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=uckYJUg3FT+Lm4+9LLDuqMsINsU2zwOGlRzMJhNqz7xrdsMuggzBLkrbHLDWQ5C168 ioZ3tsWG1WQqIMXHx9M8QlU8eP0Rx50SmUSN/EUekVM0XagsVAiVr9ucCR6IKxfupmGW BRJMbMclUaJzJlDGHy7pZyTRJkR1KFi1UJOqg= Received: by 10.223.144.84 with SMTP id y20mr8122005fau.78.1274899498047; Wed, 26 May 2010 11:44:58 -0700 (PDT) Received: from mavbook.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id r12sm1639057fah.20.2010.05.26.11.44.56 (version=SSLv3 cipher=RC4-MD5); Wed, 26 May 2010 11:44:57 -0700 (PDT) Sender: Alexander Motin Message-ID: <4BFD6C17.3020709@FreeBSD.org> Date: Wed, 26 May 2010 21:44:39 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.24 (X11/20100402) MIME-Version: 1.0 To: Matthew Jacob References: <4BFB3985.1030301@FreeBSD.org> <4BFC1C57.4080703@FreeBSD.org> <4BFD6698.9040100@feral.com> In-Reply-To: <4BFD6698.9040100@feral.com> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-scsi@FreeBSD.org Subject: Re: patches for CAM SCSI probing, etc. X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 May 2010 18:44:59 -0000 Matthew Jacob wrote: > Okay, I see your point. > > I would assert that for SCSI there should only be one probe active at > any time for any given nexus *or* I should adopt your approach and > restart the state machine if additional commands show up. > > It's also true that scans ought to be limited from user space. There's > nothing to stop one from running 1000 camcontrol rescans from user > space, and that effectively hangs the system as it's spending all of its > time running stuff for them, so I might put a bit of serialization in here. > > Thoughts? I think `camcontrol reset ...` may ban channel much easier, respecting 5 seconds of SCSI_DELAY after reset. And as soon as both of them require superuser privileges - IMHO it is a kind of foot shooting. -- Alexander Motin