From cf76d3de6e54afb361b2cb6d70893518cb7aa57c Mon Sep 17 00:00:00 2001
From: James Smart <james.smart@avagotech.com>
Date: Fri, 22 May 2015 10:42:39 -0400
Subject: [PATCH] lpfc: Fix scsi prep dma buf error.

[ Upstream commit 5116fbf136ea21b8678a85eee5c03508736ada9f ]

Didn't check for less-than-or-equal zero. Means we may later call
scsi_dma_unmap() even though we don't have valid mappings.

Signed-off-by: Dick Kennedy <dick.kennedy@avagotech.com>
Signed-off-by: James Smart <james.smart@avagotech.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
 drivers/scsi/lpfc/lpfc_scsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index b99399fe25488..15acc808658fa 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -3380,7 +3380,7 @@ lpfc_scsi_prep_dma_buf_s4(struct lpfc_hba *phba, struct lpfc_scsi_buf *lpfc_cmd)
 		 */
 
 		nseg = scsi_dma_map(scsi_cmnd);
-		if (unlikely(!nseg))
+		if (unlikely(nseg <= 0))
 			return 1;
 		sgl += 1;
 		/* clear the last flag in the fcp_rsp map entry */