From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [RFC]: 64 bit LUN/Tags, dummy device in host_queue, host_lock <-> LLDD reentrancy Date: Mon, 26 Aug 2002 14:00:52 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <200208261900.g7QJ0r501788@localhost.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: (from root@localhost) by pogo.mtv1.steeleye.com (8.9.3/8.9.3) id MAA11745 for ; Mon, 26 Aug 2002 12:01:00 -0700 In-Reply-To: Message from Mike Anderson of "Mon, 26 Aug 2002 10:27:46 PDT." <20020826172746.GA1301@beaverton.ibm.com> List-Id: linux-scsi@vger.kernel.org To: James Bottomley , Aron Zeh , Luben Tuikov , linux-scsi andmike@us.ibm.com said: > James I do not follow the usage of LUNs linked by pointers, can you > explain further? Yes: the mid-layer could function only with Scsi_Devices and Scsi_Hosts. LUNs are currently only used explicitly for scanning. However, I'd like to make the error handler handle the consequences of its action, thus it will need to know LUN relationships to handle a BDR correctly. However, the mid layer doesn't need an arbitrary number associated with LUN or PUN. Since the number, string or whatever is only really useful to the lld. So, simply put, we'd probably have an entry in the Scsi_Device for lun_list. This would be the usual doubly linked list so starting with any Scsi_Device we could always find the associated LUNs. James