Patch "iscsi-target: Drop work-around for legacy GlobalSAN initiator" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

iscsi-target: Drop work-around for legacy GlobalSAN initiator

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
iscsi-target-drop-work-around-for-legacy-globalsan-initiator.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Nicholas Bellinger <[email protected]>
Date: Sun, 2 Apr 2017 13:36:44 -0700
Subject: iscsi-target: Drop work-around for legacy GlobalSAN initiator

From: Nicholas Bellinger <[email protected]>

commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46 upstream.

Once upon a time back in 2009, a work-around was added to support the GlobalSAN iSCSI initiator v3.3 for MacOSX, which during login did not propose nor respond to MaxBurstLength, FirstBurstLength, DefaultTime2Wait and DefaultTime2Retain keys.

The work-around in iscsi_check_proposer_for_optional_reply() allowed the missing keys to be proposed, but did not require waiting for a response before moving to full feature phase operation. This allowed GlobalSAN v3.3 to work out-of-the box, and for many years we didn't run into login interopt issues with any other initiators..

Until recently, when Martin tried a QLogic 57840S iSCSI Offload HBA on Windows 2016 which completed login, but subsequently failed with:

    Got unknown iSCSI OpCode: 0x43

The issue was QLogic MSFT side did not propose DefaultTime2Wait + DefaultTime2Retain, so LIO proposes them itself, and immediately transitions to full feature phase because of the GlobalSAN hack. However, the QLogic MSFT side still attempts to respond to DefaultTime2Retain + DefaultTime2Wait, even though LIO has set ISCSI_FLAG_LOGIN_NEXT_STAGE3 + ISCSI_FLAG_LOGIN_TRANSIT in last login response.

So while the QLogic MSFT side should have been proposing these two keys to start, it was doing the correct thing per RFC-3720 attempting to respond to proposed keys before transitioning to full feature phase.

All that said, recent versions of GlobalSAN iSCSI (v5.3.0.541) does correctly propose the four keys during login, making the original work-around moot.

So in order to allow QLogic MSFT to run unmodified as-is, go ahead and drop this long standing work-around.

---
 drivers/target/iscsi/iscsi_target_parameters.c |   16 ----------------
 1 file changed, 16 deletions(-)

@@ -781,22 +781,6 @@ static void iscsi_check_proposer_for_opt
 		if (!strcmp(param->name, MAXRECVDATASEGMENTLENGTH))
 			SET_PSTATE_REPLY_OPTIONAL(param);
 		/*
-		 * The GlobalSAN iSCSI Initiator for MacOSX does
-		 * not respond to MaxBurstLength, FirstBurstLength,
-		 * DefaultTime2Wait or DefaultTime2Retain parameter keys.
-		 * So, we set them to 'reply optional' here, and assume the
-		 * the defaults from iscsi_parameters.h if the initiator
-		 * is not RFC compliant and the keys are not negotiated.
-		 */
-		if (!strcmp(param->name, MAXBURSTLENGTH))
-			SET_PSTATE_REPLY_OPTIONAL(param);
-		if (!strcmp(param->name, FIRSTBURSTLENGTH))
-			SET_PSTATE_REPLY_OPTIONAL(param);
-		if (!strcmp(param->name, DEFAULTTIME2WAIT))
-			SET_PSTATE_REPLY_OPTIONAL(param);
-		if (!strcmp(param->name, DEFAULTTIME2RETAIN))
-			SET_PSTATE_REPLY_OPTIONAL(param);
-		/*
 		 * Required for gPXE iSCSI boot client
 		 */
 		if (!strcmp(param->name, MAXCONNECTIONS))

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/iscsi-target-drop-work-around-for-legacy-globalsan-initiator.patch queue-4.4/iscsi-target-fix-tmr-reference-leak-during-session-shutdown.patch