iSCSI: Target reset text

["Mallikarjun C." <cbm@rose.hp.com>]

Julian,

- While reviewing a related T10 proposal, I realized that SAM-2 (clause 5.8.6)
  does not allow access controls for any protocol-specific hard reset events
  (and Target Cold Reset TMF is one such).  The current rev13 text seems
  to imply that both reset flavors are subject to access controls.  In any case,
  it would help to make the point.

- It is somewhat unclear at the moment if Target cold reset should/should not
  return a response.  But judging by the "equivalent to SAM-2's Target Reset"
  wording, and because SAM-2 requires a function response to be returned,
  one would have to interpret that a response is required for Cold Reset.
  I had received internal feedback about interoperability issues on this interpretation.

- I also noticed that the words "TARGET RESET" and "Target Reset" are
  apparently used interchangeably in section 9.5.1, while the former is an iSCSI-generic
  name for both flavors and the latter is the SAM-2 TMF.

- We had earlier talked about the Target Cold Reset function being equivalent to
   to a power on event (as is stated by Appendix F.2), but I think we should specify
   it in this section to make it clear to the implementers.

I suggest the following text in 9.5.1 to address the above issues.

8<-----------------------

The implementation of the TARGET WARM RESET function and the TARGET COLD RESET function is OPTIONAL and when
implemented, should act as described below. The TARGET WARM RESET function MAY also be subject to SCSI access
controls on the requesting initiator.  When authorization fails at the target, the appropriate response as
described in Section 9.6 "Task Management Function Response" must be returned by the target.  The TARGET COLD
RESET function is not subject to SCSI access controls, but its execution privileges may be managed by iSCSI
mechanisms such as login authentication.

When executing the TARGET WARM RESET and TARGET COLD RESET functions, the target cancels all pending
operations. Both functions are equivalent to the Target Reset function specified by [SAM2]. They can affect
many other initiators logged in with the servicing SCSI target port.

The target MUST treat the TARGET COLD RESET function additionally as a power on event, thus terminating all of
its TCP connections to all initiators (all sessions are terminated).  For this reason, the Service Response
(defined by [SAM2]) for this SCSI task management function may not be reliably delivered to the issuing
initiator port.

8<-----------------------

Thanks!
--
Mallikarjun

Mallikarjun Chadalapaka
Networked Storage Architecture
Network Storage Solutions
Hewlett-Packard MS 5668
Roseville CA 95747
cbm@rose.hp.com