Re: iscsi: comments to iSCSI rev 6

[Santosh Rao <santoshr@cup.hp.com>]

Matt Wakeley wrote:

> > Section 2.12.3: indicate that the LUN is copied from the NOP-IN.  This is
> > much more clear than "the correct value for the task".
> >
> > +++ and open it up to strange thing like LU5 asking a nop-out to LU7 ? +++
> 
> How will that occur?  The target sent the NOP-IN ping request.  The target
> includes a LUN.  The only "correct value" that the initiator can return for
> the LUN in the NOP-OUT ping response is the value the target sent in the
> original request.

Julian,

Re-wording the LUN descriptions in NOP-IN & NOP-OUT to read that
initiators MUST echo the LUN field from a received NOP-IN into a NOP-OUT
is a more clear and un-ambiguous definition than the current text.

That said, I still continue to have reservations about the need for a
LUN field in a non-SCSI PDU. Fibre Channel does not use the LUN field in
its ELS' & BLS'. LUN is a SCSI construct and it must not be used in
non-scsi PDUs.

I'm yet to hear strong reasons why LUN is required in the NOP-IN or
NOP-OUT. The originator of the NOP operation must generate task tags
independent of LUNs for non-SCSI PDUs. Such PDUs have no scsi context.

As a side cosmetic comment, can we re-name "Target Transfer Tag" to
"Target Task Tag" to have symmetry with the use of Initiator Task Tag ? 

- Santosh
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