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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: iSCSI: v15 R2T and DATA-OUTJulian, OK, that's the answer to my question then. The wording that's there right now doesn't say what the initiator should do if the LUN in an R2T doesn't match the LUN it sent in the command PDU. So the resolution is that the initiator should treat a LUN inconsistency between R2T and command as a protocol error. I suggest we add a note to that effect where we talk about LUN in the R2T PDU description, that would be 9.8.5 in the v15 working draft. - Rod -----Original Message----- From: Julian Satran [mailto:Julian_Satran@il.ibm.com] Sent: Thursday, July 25, 2002 6:53 PM To: Rod Harrison Cc: ips@ece.cmu.edu Subject: RE: iSCSI: v15 R2T and DATA-OUT Rod, Probably a very long day. LUN is present in the command. Command is associated with ITT. R2T can be checked for a consistent ITT and LUN. End-story. Julo "Rod Harrison" <rod.harrison@windriver.com> 07/25/2002 06:49 AM To: <ips@ece.cmu.edu> cc: Julian Satran/Haifa/IBM@IBMIL Subject: RE: iSCSI: v15 R2T and DATA-OUT OK, it's been a long day. Let me try this one more time. I was write (almost) first time but I meant DATA-OUT instead of DATA-IN. Here's what I meant to say ... There is a potential inconsistency in the description of the use of the LUN field in DATA-OUT and R2T in the working v15 draft. 9.7.3 Target Transfer Tag, for DATA-OUT last paragraph says ... "If the Target Transfer Tag is provided, then the LUN field MUST hold a valid value and be consistent with whatever was specified with the command;" 9.8.5 Target Transfer Tag, for R2T says ... "The Target Transfer Tag and LUN are copied in the outgoing data PDUs and are used by the target only." Potentially a target could return a different LUN field in the R2T, for perhaps some funky LUN mapping or other internal reason expecting it to be copied to the DATA-OUT as per the R2T text. I think we need to indicate what is expected of the initiator if the LUN field in the R2T does not match the LUN in the command PDU. - Rod -----Original Message----- From: Rod Harrison [mailto:rod.harrison@windriver.com] Sent: Wednesday, July 24, 2002 8:57 PM To: Julian Satran Cc: ips@ece.cmu.edu Subject: RE: iSCSI: v15 R2T and DATA-OUT Oops, I see the confusion. I said DATA-IN in my message when I meant DATA-OUT. However, re-reading the section of v15 in question I now see that the third paragraph is referring to the DATA-IN LUN, not the DATA-OUT LUN. That wasn't clear to me when first scanned it because of the paragraph break. Perhaps a note of clarification needs to be added? - Rod -----Original Message----- From: Rod Harrison [mailto:rod.harrison@windriver.com] Sent: Wednesday, July 24, 2002 8:51 PM To: Julian Satran Cc: ips@ece.cmu.edu Subject: RE: iSCSI: v15 R2T and DATA-OUT Julian, I think you've misread my message. I was questioning how the initiator should handle the LUN between an R2T and the DATA-OUT(s) that satisfy it. DATA-OUT says copy the LUN from the command PDU, R2T says copy the LUN from the R2T to the DATA-OUT. Which is correct if the R2T contains a different LUN than that in the command PDU? - Rod -----Original Message----- From: Julian Satran [mailto:Julian_Satran@il.ibm.com] Sent: Wednesday, July 24, 2002 5:00 PM To: Rod Harrison Cc: ips@ece.cmu.edu; owner-ips@ece.cmu.edu Subject: Re: iSCSI: v15 R2T and DATA-OUT There is no TTT for data-In. Julo "Rod Harrison" <rod.harrison@win To: <ips@ece.cmu.edu> driver.com> cc: Sent by: Subject: iSCSI: v15 R2T and DATA-OUT owner-ips@ece.cmu .edu 07/24/2002 10:24 PM Folks, There is a potential inconsistency in the description of the use of the LUN field in DATA-OUT and R2T in the working v15 draft. 9.7.3 Target Transfer Tag, for DATA-IN last paragraph says ... "If the Target Transfer Tag is provided, then the LUN field MUST hold a valid value and be consistent with whatever was specified with the command;" 9.8.5 Target Transfer Tag, for R2T says ... "The Target Transfer Tag and LUN are copied in the outgoing data PDUs and are used by the target only." Potentially a target could return a different LUN field in the R2T, for perhaps some funky LUN mapping or other internal reason expecting it to be copied to the DATA-OUT as per the R2T text. I suspect we just want to say this is not allowed and the LUN field MUST be the same as the command PDU. Either way I think we need to indicate what is expected of the initiator if the LUN field in the R2T does not match the LUN in the command PDU. Apologies for not spotting this before the end of last call. - Rod
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