From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nicholas A. Bellinger" Subject: Re: SCSI persistent reservation terms Date: Wed, 07 Apr 2010 11:47:57 -0700 Message-ID: <1270666077.3332.10.camel@haakon2.linux-iscsi.org> References: <3BEB5F9B6605A140847DEEEDF7439C5D040A06C8@CORPUSMX50A.corp.emc.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from smtp104.sbc.mail.gq1.yahoo.com ([67.195.15.63]:40472 "HELO smtp104.sbc.mail.gq1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752109Ab0DGSsE (ORCPT ); Wed, 7 Apr 2010 14:48:04 -0400 In-Reply-To: <3BEB5F9B6605A140847DEEEDF7439C5D040A06C8@CORPUSMX50A.corp.emc.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: lemons_terry@emc.com Cc: linux-scsi@vger.kernel.org On Wed, 2010-04-07 at 10:55 -0400, lemons_terry@emc.com wrote: > Hi > > I'm trying to understand one aspect of the SCSI persistent reservation functionality. > SPC-4 mentions the terms 'All Registrants' and 'Registrants Only', and applies these > to both 'Write Exclusive' and 'Exclusive Access'. Nowhere can I find a definition > of what these terms mean. If you would, please point me in the right direction. > Greetings Terry, 'All Registrants' means that the persistent reservation holder is any registstered I_T Nexus (eg: multiple reservation holders) 'Registrants Only' means that the persistent reservation holder is the single registered I_T Nexus that has obtained the reservation via RESERVE, PREEMPT, PREEMPT_AND_ABORT, or via another I_T Nexus with REGISTER_AND_MOVE. (eg: single reservation holder) You can find how this logic works for multi-fabric target mode by grepping '_ALLREG' and '_REGONLY' in TCM code at: http://git.kernel.org/?p=linux/kernel/git/nab/lio-core-2.6.git;a=blob;f=drivers/target/target_core_pr.c Best, --nab