From: AMEET M. PARANJAPE <aparanja@redhat.com>
Date: Fri, 26 Jun 2009 09:37:26 -0400
Subject: [scsi] ibmvfc: improve LOGO/PRLO ELS handling
Message-id: 20090626133357.24116.79464.sendpatchset@squad5-lp1.lab.bos.redhat.com
O-Subject: [PATCH RHEL5.4 BZ508127 1/3] ibmvfc: Improve LOGO/PRLO ELS handling
Bugzilla: 508127
RH-Acked-by: David Howells <dhowells@redhat.com>

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

Description:
===========
There are several scenarios where the ibmvfc driver needs to try to log back
into a target on the fabric. Today when these events occur, we simply go
through re-discovery for all attached targets, assuming that either the query
of the name server or an ADISC will indicate we might need to log back into the
target, which doesn't work for all scenarios. Fix this by taking note of the
affected target(s) in these conditions and ensuring we try to PLOGI back into
the target.

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=6d29cc56bead73b6f386cf43333708579deb5eed

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 4268f57..97f2912 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -1512,6 +1512,27 @@ static void ibmvfc_log_error(struct ibmvfc_event *evt)
 }
 
 /**
+ * ibmvfc_relogin - Log back into the specified device
+ * @sdev:	scsi device struct
+ *
+ **/
+static void ibmvfc_relogin(struct scsi_device *sdev)
+{
+	struct ibmvfc_host *vhost = shost_priv(sdev->host);
+	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
+	struct ibmvfc_target *tgt;
+
+	list_for_each_entry(tgt, &vhost->targets, queue) {
+		if (rport == tgt->rport) {
+			ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
+			break;
+		}
+	}
+
+	ibmvfc_reinit_host(vhost);
+}
+
+/**
  * ibmvfc_scsi_done - Handle responses from commands
  * @evt:	ibmvfc event to be handled
  *
@@ -1543,7 +1564,7 @@ static void ibmvfc_scsi_done(struct ibmvfc_event *evt)
 			if ((rsp->flags & FCP_SNS_LEN_VALID) && rsp->fcp_sense_len && rsp_len <= 8)
 				memcpy(cmnd->sense_buffer, rsp->data.sense + rsp_len, sense_len);
 			if ((vfc_cmd->status & IBMVFC_VIOS_FAILURE) && (vfc_cmd->error == IBMVFC_PLOGI_REQUIRED))
-				ibmvfc_reinit_host(evt->vhost);
+				ibmvfc_relogin(cmnd->device);
 
 			if (!cmnd->result && (!scsi_get_resid(cmnd) || (rsp->flags & FCP_RESID_OVER)))
 				cmnd->result = (DID_ERROR << 16);
@@ -2212,6 +2233,7 @@ static void ibmvfc_handle_async(struct ibmvfc_async_crq *crq,
 				struct ibmvfc_host *vhost)
 {
 	const char *desc = ibmvfc_get_ae_desc(crq->event);
+	struct ibmvfc_target *tgt;
 
 	ibmvfc_log(vhost, 3, "%s event received. scsi_id: %lx, wwpn: %lx,"
 		   " node_name: %lx\n", desc, crq->scsi_id, crq->wwpn, crq->node_name);
@@ -2232,9 +2254,23 @@ static void ibmvfc_handle_async(struct ibmvfc_async_crq *crq,
 	case IBMVFC_AE_SCN_NPORT:
 	case IBMVFC_AE_SCN_GROUP:
 		vhost->events_to_log |= IBMVFC_AE_RSCN;
+		ibmvfc_reinit_host(vhost);
+		break;
 	case IBMVFC_AE_ELS_LOGO:
 	case IBMVFC_AE_ELS_PRLO:
 	case IBMVFC_AE_ELS_PLOGI:
+		list_for_each_entry(tgt, &vhost->targets, queue) {
+			if (!crq->scsi_id && !crq->wwpn && !crq->node_name)
+				break;
+			if (crq->scsi_id && tgt->scsi_id != crq->scsi_id)
+				continue;
+			if (crq->wwpn && tgt->ids.port_name != crq->wwpn)
+				continue;
+			if (crq->node_name && tgt->ids.node_name != crq->node_name)
+				continue;
+			ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
+		}
+
 		ibmvfc_reinit_host(vhost);
 		break;
 	case IBMVFC_AE_LINK_DOWN: