From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nicholas A. Bellinger" Subject: Re: [Scst-devel] Fwd: Re: linuxcon 2010... Date: Thu, 26 Aug 2010 14:23:26 -0700 Message-ID: <1282857806.32007.175.camel@haakon2.linux-iscsi.org> References: <594039.74663.qm@web111905.mail.gq1.yahoo.com> <1282144271.3035.31.camel@mulgrave.site> <1282148296.3035.49.camel@mulgrave.site> <4C6C1D70.7020502@vlnb.net> <41A1E2691BBB412BADCDE5F515CD8EDA@usish.com.cn> <8A96806D-6CD7-44AD-8A9D-143C098C95A4@uni-paderborn.de> <1282256949.30453.278.camel@haakon2.linux-iscsi.org> <4C701E08.2020005@vlnb.net> <1282423398.3015.39.camel@mulgrave.site> <4C73DA15.2010207@vlnb.net> <1282661876.2993.20.camel@mulgrave.site> <4C7421FB.2060007@vlnb.net> <1282685014.32007.51.camel@haakon2.linux-iscsi.org> <4C76CA57.3050405@vlnb.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from smtp106.sbc.mail.gq1.yahoo.com ([67.195.14.109]:29056 "HELO smtp106.sbc.mail.gq1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754341Ab0HZV1P (ORCPT ); Thu, 26 Aug 2010 17:27:15 -0400 In-Reply-To: <4C76CA57.3050405@vlnb.net> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Vladislav Bolkhovitin Cc: James Bottomley , Dirk Meister , linux-scsi@vger.kernel.org, Chetan Loke , Chetan Loke , scst-devel , linux-kernel@vger.kernel.org, Mike Christie , FUJITA Tomonori On Fri, 2010-08-27 at 00:11 +0400, Vladislav Bolkhovitin wrote: > Nicholas A. Bellinger, on 08/25/2010 01:23 AM wrote: > > As mentioned explictly earlier in this thread, my WIP code for the > > kernel level subsystem backstore using STGT kernel<-> user CDB > > passthrough logic in drivers/target/target_core_stgt.c is a item on > > my TODO list, but I will repeat, is NOT being tagged as a mainline > > .37 item. > > Hmm, I can't understand, if target_core_stgt.c is "NOT being tagged as a > mainline .37 item", then the STGT ABI compatibility for being a drop in > replacement for STGT isn't a requirement? Or am I missing something? > Sorry, but I have no idea what you are trying to conjour up here. To spell out (again) the TCM/LIO<->STGT compatibility stages that have been persued pubically over the last months: I) Create proper userspace tgt.git SG_IO and BSG passthrough into TCM_Loop v4 using high-level multi-fabric WWPN emulation so that TCM Core SPC-4 kernel emulation is exposed to STGT user fabrics, eg: userspace fabric module -> kernel backstore passthrough. (DONE for .37, and STGT passthrough + BSG backstore support merged into tgt.git by Tomo-san) II) Complete target_core_stgt.c TCM subsystem plugin for kernel -> user CDB -> LUN passthrough building upon existing drivers/scsi/scsi_tgt_*.c code. (WIP for .38, made available initially as a seperate standalone .ko module in lio-core-2.6.git) > > Tomo-san, mnc, and other storage folks have been briefed on the > > remaining issues that would be involved to get a prototype > > functioning with drivers/target/target_core_stgt.c, and rough idea of > > what it would take in existing mainline drivers/scsi/scsi_tgt_*.c > > code. With the current WIP code this will allow the userspace CDB -> > > LUN passthrough to function transparently with all TCM SPC-4 > > compliant logic as a standalone struct se_subsystem_api > > tcm_core_stgt.ko backstore. > > This is exactly what we are discussing. Then I suggest you start working on a patch for drivers/scsi/scsi_tgt_* in order to address what you believe are the preceived shortcomings of the original design. Until you can do that, and actually take an impartial look at the existing drivers/scsi/scsi_tgt_*.c, it would be a bit difficult to beleive you genuinely want to steer our current level of interaction away from continued hand-waving noise into a real rational technical discourse between yourself and the LIO/STGT development community. Best, --nab