From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Christie Subject: Re: [linux-iscsi-devel] Re: [PATCH RFC] replace ioctl for sysfs take 2 Date: Tue, 07 Sep 2004 14:37:27 -0700 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <413E2A17.80107@us.ibm.com> References: <20040907210520.0251476C56@isis.visi.com> <413E2440.8080509@cs.wisc.edu> <1094592818.1716.159.camel@mulgrave> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from e32.co.us.ibm.com ([32.97.110.130]:44000 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S268261AbUIGVnQ (ORCPT ); Tue, 7 Sep 2004 17:43:16 -0400 In-Reply-To: <1094592818.1716.159.camel@mulgrave> List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Mike Christie , "Scott M. Ferris" , Matthew Wilcox , Christoph Hellwig , iscsi -devel , David Wysochanski , "Surekha.PC" , SCSI Mailing List James Bottomley wrote: > On Tue, 2004-09-07 at 17:12, Mike Christie wrote: > >>>This is exactly why I ask these questions. The iSCSI driver >>>developers just implemented this, because they thought this is what >>>you and Christoph were asking for. Apparently it's not what you >>>wanted. >> >>Thank you for clarifying this. So we should go back to a single linux host, >>right? The iscsi session is an I_T nexus, so the only way to store the >>session state in the host is to allocate a session per host. > > > No; for iscsi, the host and target for I_T is the right thing to do. > > The reason why doesn't lie in terminology or a specification, it lies in > the code. > > When the cisco-iscsi driver was first presented, it had a single host > for everything and a huge connection management resource array hanging > off that. This was clearly wrong beacuse there was a huge overhead > managing the array. The correct approach was to make the host > correspond to a single element of that array and use the mid-layer host > management functions instead of home grown resource management > functions. Doing it this way makes both the management and presentation > of the information more logical and the code cleaner. Ok. If the new magic iscsi transport specific target code handles target data like the scsi_host does for hostdata then would it be better to put our session struct in the target data? I think this also simplifies refcounting. Most session stuff makes sense hanging off the target so this might be easier, right? > James > > >