From: Rob Evers <revers@redhat.com>
Date: Tue, 5 Oct 2010 14:24:33 -0400
Subject: [scsi] lpfc: fix RoundRobin FCF failover issue
Message-id: <1286288695-20754-2-git-send-email-revers@redhat.com>
Patchwork-id: 28595
O-Subject: [RHEL5.6 PATCH 01/23] Fixed RoundRobin FCF failover due to
	mis-interpretation of kernel find_next_bit (CR: 103435)
Bugzilla: 619917
RH-Acked-by: Tomas Henzl <thenzl@redhat.com>

Fixed RoundRobin FCF failover due to mis-interpretation of kernel find_next_bit (CR: 103435)

https://bugzilla.redhat.com/show_bug.cgi?id=619917

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 956b988..c9a6a35 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -824,6 +824,11 @@ lpfc_cmpl_els_flogi(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 				phba->fcf.fcf_flag &= ~FCF_DISCOVERY;
 				spin_unlock_irq(&phba->hbalock);
 			} else {
+				lpfc_printf_log(phba, KERN_INFO,
+						LOG_FIP | LOG_ELS,
+						"2794 FLOGI FCF round robin "
+						"failover to FCF index x%x\n",
+						fcf_index);
 				rc = lpfc_sli4_fcf_rr_read_fcf_rec(phba,
 								   fcf_index);
 				if (rc) {
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 8902e32..8468bc4 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -12471,19 +12471,30 @@ lpfc_sli4_fcf_rr_next_index_get(struct lpfc_hba *phba)
 {
 	uint16_t next_fcf_index;
 
-	/* Search from the currently registered FCF index */
+	/* Search start from next bit of currently registered FCF index */
+	next_fcf_index = (phba->fcf.current_rec.fcf_indx + 1) %
+					LPFC_SLI4_FCF_TBL_INDX_MAX;
 	next_fcf_index = find_next_bit(phba->fcf.fcf_rr_bmask,
 				       LPFC_SLI4_FCF_TBL_INDX_MAX,
-				       phba->fcf.current_rec.fcf_indx);
+				       next_fcf_index);
+
 	/* Wrap around condition on phba->fcf.fcf_rr_bmask */
 	if (next_fcf_index >= LPFC_SLI4_FCF_TBL_INDX_MAX)
 		next_fcf_index = find_next_bit(phba->fcf.fcf_rr_bmask,
 					       LPFC_SLI4_FCF_TBL_INDX_MAX, 0);
+
 	/* Round robin failover stop condition */
 	if ((next_fcf_index == phba->fcf.fcf_rr_init_indx) ||
-		(next_fcf_index >= LPFC_SLI4_FCF_TBL_INDX_MAX))
+		(next_fcf_index >= LPFC_SLI4_FCF_TBL_INDX_MAX)) {
+		lpfc_printf_log(phba, KERN_WARNING, LOG_FIP,
+				"2844 Round robin failover FCF index search "
+				"hit stop condition:x%x\n", next_fcf_index);
 		return LPFC_FCOE_FCF_NEXT_NONE;
+	}
 
+	lpfc_printf_log(phba, KERN_INFO, LOG_FIP,
+			"2845 Get next round robin failover "
+			"FCF index x%x\n", next_fcf_index);
 	return next_fcf_index;
 }
 
@@ -12513,11 +12524,15 @@ lpfc_sli4_fcf_rr_index_set(struct lpfc_hba *phba, uint16_t fcf_index)
 	/* Set the eligible FCF record index bmask */
 	set_bit(fcf_index, phba->fcf.fcf_rr_bmask);
 
+	lpfc_printf_log(phba, KERN_INFO, LOG_FIP,
+			"2790 Set FCF index x%x to round robin failover "
+			"bmask\n", fcf_index);
+
 	return 0;
 }
 
 /**
- * lpfc_sli4_fcf_rr_index_set - Clear bmask from eligible fcf record index
+ * lpfc_sli4_fcf_rr_index_clear - Clear bmask from eligible fcf record index
  * @phba: pointer to lpfc hba data structure.
  *
  * This routine clears the FCF record index from the eligible bmask for
@@ -12538,6 +12553,10 @@ lpfc_sli4_fcf_rr_index_clear(struct lpfc_hba *phba, uint16_t fcf_index)
 	}
 	/* Clear the eligible FCF record index bmask */
 	clear_bit(fcf_index, phba->fcf.fcf_rr_bmask);
+
+	lpfc_printf_log(phba, KERN_INFO, LOG_FIP,
+			"2791 Clear FCF index x%x from round robin failover "
+			"bmask\n", fcf_index);
 }
 
 /**