[dm-devel] [PATCH 2/2] scsi : fixing the new host byte settings (DID_TARGET_FAILURE and DID_NEXUS_FAILURE)

[Moger, Babu]

Resubmitting as my previous post had format issues and did not go linux-scsi.

This patch fixes the host byte settings DID_TARGET_FAILURE and DID_NEXUS_FAILURE.
The function __scsi_error_from_host_byte,  tries to reset the host byte to DID_OK. But that
does not happen because of the OR operation. 

Here is the flow.
scsi_softirq_done-> scsi_decide_disposition -> __scsi_error_from_host_byte

Let's take an example with DID_NEXUS_FAILURE. In scsi_decide_disposition, result will be set as
DID_NEXUS_FAILURE (=0x11). Then in __scsi_error_from_host_byte, when we do OR with 
DID_OK.  Purpose is to reset it back to DID_OK. But that does not happen.  This patch fixes this issue. 

Signed-off-by: Babu Moger <babu.moger at netapp.com>
---
diff -uprN -X linux-3.3-rc1/Documentation/dontdiff linux-3.3-rc1//drivers/scsi/scsi_error.c linux-3.3-rc1-new//drivers/scsi/scsi_error.c
--- linux-3.3-rc1//drivers/scsi/scsi_error.c	2012-01-19 17:04:48.000000000 -0600
+++ linux-3.3-rc1-new//drivers/scsi/scsi_error.c	2012-01-23 11:55:26.000000000 -0600
@@ -1540,7 +1540,7 @@ int scsi_decide_disposition(struct scsi_
 			 * Need to modify host byte to signal a
 			 * permanent target failure
 			 */
-			scmd->result |= (DID_TARGET_FAILURE << 16);
+			set_host_byte(scmd, DID_TARGET_FAILURE);
 			rtn = SUCCESS;
 		}
 		/* if rtn == FAILED, we have no sense information;
@@ -1560,7 +1560,7 @@ int scsi_decide_disposition(struct scsi_
 	case RESERVATION_CONFLICT:
 		sdev_printk(KERN_INFO, scmd->device,
 			    "reservation conflict\n");
-		scmd->result |= (DID_NEXUS_FAILURE << 16);
+		set_host_byte(scmd, DID_NEXUS_FAILURE);
 		return SUCCESS; /* causes immediate i/o error */
 	default:
 		return FAILED;
diff -uprN -X linux-3.3-rc1/Documentation/dontdiff linux-3.3-rc1//drivers/scsi/scsi_lib.c linux-3.3-rc1-new//drivers/scsi/scsi_lib.c
--- linux-3.3-rc1//drivers/scsi/scsi_lib.c	2012-01-19 17:04:48.000000000 -0600
+++ linux-3.3-rc1-new//drivers/scsi/scsi_lib.c	2012-01-23 11:50:25.000000000 -0600
@@ -682,11 +682,11 @@ static int __scsi_error_from_host_byte(s
 		error = -ENOLINK;
 		break;
 	case DID_TARGET_FAILURE:
-		cmd->result |= (DID_OK << 16);
+		set_host_byte(cmd, DID_OK);
 		error = -EREMOTEIO;
 		break;
 	case DID_NEXUS_FAILURE:
-		cmd->result |= (DID_OK << 16);
+		set_host_byte(cmd, DID_OK);
 		error = -EBADE;
 		break;
 	default: