--- linux-2.6.31-rc5/drivers/scsi/device_handler/scsi_dh_rdac.c.orig	2009-08-05 16:30:51.000000000 -0500
+++ linux-2.6.31-rc5/drivers/scsi/device_handler/scsi_dh_rdac.c	2009-08-17 09:15:03.000000000 -0500
@@ -135,6 +135,8 @@ struct rdac_controller {
 		struct rdac_pg_legacy legacy;
 		struct rdac_pg_expanded expanded;
 	} mode_select;
+	u8			index;
+	u8			array_name[31];
 };
 struct c8_inquiry {
 	u8	peripheral_info;
@@ -198,6 +200,31 @@ static const char *lun_state[] =
 static LIST_HEAD(ctlr_list);
 static DEFINE_SPINLOCK(list_lock);
 
+/* 
+ * module parameter to enable rdac debug logging.
+ * 2 bits for each type of logging, only two types defined for now 
+ * Can be enhanced if required at later point
+ */
+static int rdac_logging = 1;
+module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
+		"Default is 1 - failover logging enabled, "
+		"set it to 0xF to enable all the logs");
+
+#define RDAC_LOG_FAILOVER	0
+#define RDAC_LOG_SENSE		2
+
+#define RDAC_LOG_BITS		2
+
+#define RDAC_LOG_LEVEL(SHIFT)  \
+        ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
+
+#define RDAC_DEBUG(SHIFT, sdev, f, arg...) \
+do { \
+	if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
+		sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
+} while (0);
+
 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
 {
 	struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
@@ -324,6 +351,13 @@ static struct rdac_controller *get_contr
 	/* initialize fields of controller */
 	memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN);
 	memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN);
+
+	/* update the controller index */
+	if (slot_id[1] == 0x31)
+		ctlr->index = 0;
+	else
+		ctlr->index = 1;
+
 	kref_init(&ctlr->kref);
 	ctlr->use_ms10 = -1;
 	list_add(&ctlr->node, &ctlr_list);
@@ -381,6 +415,26 @@ static int get_lun(struct scsi_device *s
 	return err;
 }
 
+static int get_array_name(struct scsi_device *sdev, struct rdac_dh_data *h)
+{
+	int err, i;
+	struct c8_inquiry *inqp;
+
+	err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
+	if (err == SCSI_DH_OK) {
+		inqp = &h->inq.c8;
+		if (inqp->page_code != 0xc8)
+			return SCSI_DH_NOSYS;
+
+		for(i=0; i<30; ++i) {
+			h->ctlr->array_name[i] = inqp->array_user_label[(2*i)+1];
+		}
+		h->ctlr->array_name[30] = '\0';
+	}
+			
+	return err;
+}
+
 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 {
 	int err;
@@ -450,13 +504,12 @@ static int mode_select_handle_sense(stru
 {
 	struct scsi_sense_hdr sense_hdr;
 	int err = SCSI_DH_IO, ret;
+	struct rdac_dh_data *h = get_rdac_data(sdev);
 
 	ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 	if (!ret)
 		goto done;
 
-	err = SCSI_DH_OK;
-
 	switch (sense_hdr.sense_key) {
 	case NO_SENSE:
 	case ABORTED_COMMAND:
@@ -478,12 +531,15 @@ static int mode_select_handle_sense(stru
 			err = SCSI_DH_RETRY;
 		break;
 	default:
-		sdev_printk(KERN_INFO, sdev,
-			    "MODE_SELECT failed with sense %02x/%02x/%02x.\n",
-			    sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
+		break;
 	}
 
 done:
+	RDAC_DEBUG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
+		"MODE_SELECT returned with sense %02x/%02x/%02x",
+		(char *) h->ctlr->array_name, h->ctlr->index,
+		sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
+		
 	return err;
 }
 
@@ -499,7 +555,9 @@ retry:
 	if (!rq)
 		goto done;
 
-	sdev_printk(KERN_INFO, sdev, "%s MODE_SELECT command.\n",
+	RDAC_DEBUG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
+		"%s MODE_SELECT command",
+		(char *) h->ctlr->array_name, h->ctlr->index,
 		(retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 
 	err = blk_execute_rq(q, NULL, rq, 1);
@@ -509,8 +567,12 @@ retry:
 		if (err == SCSI_DH_RETRY && retry_cnt--)
 			goto retry;
 	}
-	if (err == SCSI_DH_OK)
+	if (err == SCSI_DH_OK) {
 		h->state = RDAC_STATE_ACTIVE;
+		RDAC_DEBUG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
+				"MODE_SELECT completed",
+				(char *) h->ctlr->array_name, h->ctlr->index);
+	}
 
 done:
 	return err;
@@ -525,12 +587,6 @@ static int rdac_activate(struct scsi_dev
 	if (err != SCSI_DH_OK)
 		goto done;
 
-	if (!h->ctlr) {
-		err = initialize_controller(sdev, h);
-		if (err != SCSI_DH_OK)
-			goto done;
-	}
-
 	if (h->ctlr->use_ms10 == -1) {
 		err = set_mode_select(sdev, h);
 		if (err != SCSI_DH_OK)
@@ -559,6 +615,12 @@ static int rdac_check_sense(struct scsi_
 				struct scsi_sense_hdr *sense_hdr)
 {
 	struct rdac_dh_data *h = get_rdac_data(sdev);
+		
+	RDAC_DEBUG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
+			"command returned with sense %02x/%02x/%02x",
+			(char *) h->ctlr->array_name, h->ctlr->index,
+			sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
+
 	switch (sense_hdr->sense_key) {
 	case NOT_READY:
 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
@@ -678,6 +740,16 @@ static int rdac_bus_attach(struct scsi_d
 	if (err != SCSI_DH_OK)
 		goto failed;
 
+	if (!h->ctlr) {
+		err = initialize_controller(sdev, h);
+		if (err != SCSI_DH_OK)
+			goto failed;
+		
+		err = get_array_name(sdev, h);
+		if (err != SCSI_DH_OK)
+			goto failed;
+	}
+
 	if (!try_module_get(THIS_MODULE))
 		goto failed;
 
