What if there is no Process Login?

Binford, Charles cbinford at lsil.com
Thu Dec 16 15:34:29 PST 1999


* From the T10 Reflector (t10 at t10.org), posted by:
* "Binford, Charles" <charles.binford at lsil.com>
*
You can't send P_RJT in class 3.  That is why PLDA came up with the "discard
and send a PRLO".  I disagree with the statement that this is not "PH
compliant". Section 15.12.1 of FS describes operation of PRLO and it says
"following PRLO execution, all active Sequences are terminated by invoking
Abort Sequence (ABTS) protocol."  So, in the scenario in question:

- Initiator sends FCP_CMND to target without a PRLI
- Target receives the command, detects no PRLI and sends PRLO
  (no rules in PH about when you may send PRLO - PLDA added this behavioral
rule to fill in this gap).
- Initiator receives the PRLO and (following PH rules) sends ABTS to cleanup
the FCP_CMND exchange.
  (note PH is not specific as to which port shall initiate the ABTS -
following normal FCP behavior I believe the initiator should - he sent the
CMD).

So, since PRLI behavior is an FC-4 specific thing, I believe this IS an
FCP-2 issue and it should be solved the same way PLDA did.

(if it ain't broke......)

Charles Binford
LSI Logic Storage Systems
(316) 636-8566


-----Original Message-----
From: Bob Snively [mailto:Bob.Snively at EBay.Sun.COM]
Sent: Thursday, December 16, 1999 1:03 PM
To: fc at network.com; t10 at t10.org
Subject: What if there is no Process Login?


* From the T10 Reflector (t10 at t10.org), posted by:
* Bob Snively <Bob.Snively at EBay.Sun.COM>
*

Well, if you are talking to a disk drive, it should be a simple block
of aluminum with a non-descript NL_Port attached.  Similarly for an
initiator, although the block of aluminum may weigh a bit more.

However, what that really means is not covered in FCP-2.  Here is my
FCP-2 centric answer to the question, which will go in T10/99-325r2
unless someone has a better idea:

	8.4  Behavior if no PRLI

	FCP-2 does not say what to do when PRLI has not been done to a
	device and an FCP command is sent out to it.

	FC-PLDA section 9.7 specifies that the responder should send
	back a logout and discard the command.  This is not an FC-PH
	compliant action, and needs to be fixed up.  

	There are actually two cases of interest. If the devices
	support implicit PRLI, then the FCP command is expected to be
	accepted and executed normally.  If the devices do not support
	implicit PRLI, the target device first needs to clean up the
	exchange by sending back a P_RJT indicating "Login required".
	An additional P_RJT code of "Process Login Required" may also
	be needed.  Whoever is most interested, the recipient or the
	originator, should then perform the appropriate login and
	continue operation.

	This is an FC-FS problem and not an FCP-2 problem. It seems
	pretty clearly implied by 14.3.3.3 of FC-FS.

	To be proposed for FC-FS, if approved by e-mail.


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