From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luben Tuikov Subject: Re: [PATCH] make the SCSI mid-layer obey the device online flag Date: Fri, 06 Jun 2003 19:27:45 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <3EE12371.90403@rogers.com> References: <1054742495.1674.18.camel@mulgrave> <20030604165146.GA1426@beaverton.ibm.com> <1054754103.2360.8.camel@mulgrave> <20030606073603.A13259@infradead.org> <3EE0B316.4060207@rogers.com> <1054913984.1778.31.camel@mulgrave> <3EE0B8D8.4020909@rogers.com> <20030606215152.B3240@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from fep04-mail.bloor.is.net.cable.rogers.com ([66.185.86.74]:58668 "EHLO fep04-mail.bloor.is.net.cable.rogers.com") by vger.kernel.org with ESMTP id S262358AbTFFXOM (ORCPT ); Fri, 6 Jun 2003 19:14:12 -0400 In-Reply-To: <20030606215152.B3240@infradead.org> List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: James Bottomley , Mike Anderson , SCSI Mailing List , Alan Stern Christoph Hellwig wrote: > On Fri, Jun 06, 2003 at 11:52:56AM -0400, Luben Tuikov wrote: > >>>Thus, we allow any special command because we assume it's part of error >>>handling (or post error clean up). >> >>So SCSI Core _has_ decided to know about ULP (block, tape, optical). >> >>Unless we (SCSI Core) generate those, it's a pickle to decide >>which are ``special'' enough commands. I think that we'll see >>more user space drivers controlling devices via sg sending >>commands to the device for exactly those kinds of problems... >>Else the burden on SCSI Core will/might be too great. > > > I think James means REQ_SPECIAL request. But some of them aren't > special enough so we might need another flag for those. But > having knowledge about the upper drivers in the core sounds like > a really bad idea. *If* eh is to be done in SCSI Core you just cannot avoid it -- this is *the whole point* which James had in mind to allow to send cmnds if !online. (see prev msgs on this thread) (More things I want to mention here on this, but 1. No time (I'm late for a meeting) and 2. I see no point -- you'll manage just fine.) -- Luben