From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luben Tuikov Subject: Re: [PATCH] minimal SAS transport class Date: Fri, 26 Aug 2005 15:44:14 -0400 Message-ID: <430F710E.7020206@adaptec.com> References: <9BB4DECD4CFE6D43AA8EA8D768ED51C21D7A4B@xbl3.ma.emulex.com> <430B5CDB.9070204@s5r6.in-berlin.de> <430BB91F.7000406@vger.kernel.org> <20050824091230.GB26447@infradead.org> <430F398A.30200@adaptec.com> <430F6C56.1090801@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from magic.adaptec.com ([216.52.22.17]:21736 "EHLO magic.adaptec.com") by vger.kernel.org with ESMTP id S1030237AbVHZToS (ORCPT ); Fri, 26 Aug 2005 15:44:18 -0400 In-Reply-To: <430F6C56.1090801@pobox.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jeff Garzik Cc: Christoph Hellwig , linux-scsi@vger.kernel.org, Stefan Richter On 08/26/05 15:24, Jeff Garzik wrote: > Luben Tuikov wrote: > >>Even simpler: the transport layer, calls SCSI Core, saying: "Hey here is >>a pointer to struct scsi_domain_device. If you want, you an send REPORT >>LUNS and other things to it." > > > For the SG_IO ioctl, /dev/sg and request_queue usage, SCSI core must map > an address (currently HCIL) into a scsi_domain_device pointer. These The request queue is associated with the LU, not the scsi_domain_device. When SCSI Core discovers the LU, it sets up the request queue for it, etc. Again this is the role of SCSI Core, not messing up with transport specific stuff. > upper layer kernel elements rely on this "SCSI address", and rely on the > fact that SCSI core can route from a block device straight to a SCSI > LLD, using nothing more than this "SCSI address." I don't get this. > That is the heart of the routing/addressing that the SCSI core must perform. Disagree: now: scsi_device <--> request_queue, then: struct LU <--> request_queue. The LU points to the domain_device (as its parent). The domain_device has a void *lldd_dev in it. > Right now the addressing is hardcoded to HCIL. But that can be > changed... One proposal was to use (host,string) identifiers. Who? Who is proposing this? I never saw an email to SCSI Core about this proposal? Is there any more information about this proposal and what is the justification of it? Any specs and docs? Luben