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 16:10:19 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <200208262110.g7QLAJ312481@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 OAA08195 for ; Mon, 26 Aug 2002 14:10:24 -0700 In-Reply-To: Message from Mike Anderson of "Mon, 26 Aug 2002 13:57:20 PDT." <20020826205720.GE1301@beaverton.ibm.com> List-Id: linux-scsi@vger.kernel.org To: James Bottomley , linux-scsi andmike@us.ibm.com said: > Ok, so we are looking for a sibling check Exactly. > Example tree > devices/root/pci0/00:09.0/name "PCI device 1014:002e" > devices/root/pci0/00:09.0/0/name "scsi0" > devices/root/pci0/00:09.0/0/0/name "chan0" > devices/root/pci0/00:09.0/0/0/1/name "tgt1" > devices/root/pci0/00:09.0/0/0/1/1/name "lun1" > devices/root/pci0/00:09.0/0/0/1/0/name "lun0" > devices/root/pci0/00:09.0/0/0/0/name "tgt0" > devices/root/pci0/00:09.0/0/0/0/1/name "lun1" > devices/root/pci0/00:09.0/0/0/0/0/name "lun0" I'm not too happy with this tree. The unique string devices/root/pci0/00:09.0/name "PCI device 1014:002e" is enough to enumerate the scsi card (as long as it's not multi-function). If I follow my PUN/LUN position to its logical conclusion, we no longer need scsi host numbers, either. tgt1 is really a fiction: For a device that has luns there's usually no such thing as the target address (traditionally, it's LUN 0). However, fundamentally, the point is that moving all this entirely into driverfs means that scsi doesn't need to care what the tree looks like, it just has mappings into parts of it. James