From: AMEET M. PARANJAPE <aparanja@redhat.com>
Date: Fri, 26 Jun 2009 09:37:31 -0400
Subject: [scsi] ibmvfc: fix endless PRLI loop in discovery
Message-id: 20090626133402.24116.39685.sendpatchset@squad5-lp1.lab.bos.redhat.com
O-Subject: [PATCH RHEL5.4 BZ508127 2/3] ibmvfc: Fix endless PRLI loop in discovery
Bugzilla: 508127
RH-Acked-by: David Howells <dhowells@redhat.com>

RHBZ#:
======
https://bugzilla.redhat.com/show_bug.cgi?id=508127

Description:
===========
Fixes a problem seen where sending a PRLI to a target resulted in it sending a
LOGO. This caused the ibmvfc driver to go back through discovery again, which
caused another PRLI attempt, which caused another LOGO. Fix this behavior by
ignoring LOGO if we haven't even logged into the target yet.

RHEL Version Found:
================
RHEL 5.4

kABI Status:
============
No symbols were harmed.

Brew:
=====
Built on all platforms.
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1862866

Upstream Status:
================
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=017b2ae33c0fc7d70320cc7f1cce0efb6ce8d929

Test Status:
============
Without this patch an environment setup of a Power 6 blade using QLogic FC
adapter with NPIV attached to a DS4800 will cause the blade to periodically
hang making the system unusable.

With the set of patches applied the system behaves normally.

===============================================================
Ameet Paranjape 978-392-3903 ext 23903
IBM on-site partner

Proposed Patch:
===============

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 97f2912..c67c6f1 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -2268,10 +2268,13 @@ static void ibmvfc_handle_async(struct ibmvfc_async_crq *crq,
 				continue;
 			if (crq->node_name && tgt->ids.node_name != crq->node_name)
 				continue;
-			ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
+			if (tgt->need_login && crq->event == IBMVFC_AE_ELS_LOGO)
+				tgt->logo_rcvd = 1;
+			if (!tgt->need_login || crq->event == IBMVFC_AE_ELS_PLOGI) {
+				ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
+				ibmvfc_reinit_host(vhost);
+			}
 		}
-
-		ibmvfc_reinit_host(vhost);
 		break;
 	case IBMVFC_AE_LINK_DOWN:
 	case IBMVFC_AE_ADAPTER_FAILED:
@@ -2961,7 +2964,11 @@ static void ibmvfc_tgt_prli_done(struct ibmvfc_event *evt)
 		tgt_err(tgt, "Process Login failed: %s (%x:%x) rc=0x%02X\n",
 			ibmvfc_get_cmd_error(rsp->status, rsp->error),
 			rsp->status, rsp->error, status);
-		if (ibmvfc_retry_cmd(rsp->status, rsp->error))
+		if ((rsp->status & IBMVFC_VIOS_FAILURE) && rsp->error == IBMVFC_PLOGI_REQUIRED)
+			ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_plogi);
+		else if (tgt->logo_rcvd)
+			ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_plogi);
+		else if (ibmvfc_retry_cmd(rsp->status, rsp->error))
 			ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_prli);
 		else
 			ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
@@ -3083,6 +3090,7 @@ static void ibmvfc_tgt_send_plogi(struct ibmvfc_target *tgt)
 		return;
 
 	kref_get(&tgt->kref);
+	tgt->logo_rcvd = 0;
 	evt = ibmvfc_get_event(vhost);
 	vhost->discovery_threads++;
 	ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_INIT_WAIT);
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
index cad382f..5af93ec 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.h
+++ b/drivers/scsi/ibmvscsi/ibmvfc.h
@@ -585,6 +585,7 @@ struct ibmvfc_target {
 	enum ibmvfc_target_action action;
 	int need_login;
 	int init_retries;
+	int logo_rcvd;
 	struct ibmvfc_service_parms service_parms;
 	struct ibmvfc_service_parms service_parms_change;
 	struct fc_rport_identifiers ids;