[SCSI] libsas: Start I_T recovery if ABORT TASK fails

The EH should fall into I_T recovery (and potentially stronger
remedies) if ABORT TASK fails.

Signed-off-by: Alexis Bruemmer <alexisb@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/libsas/sas_scsi_host.c

@@ -281,6 +281,7 @@ enum task_disposition {
 	TASK_IS_ABORTED,
 	TASK_IS_AT_LU,
 	TASK_IS_NOT_AT_LU,
+	TASK_ABORT_FAILED,
 };
 
 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
@@ -331,15 +332,21 @@ static enum task_disposition sas_scsi_find_task(struct sas_task *task)
 			SAS_DPRINTK("%s: querying task 0x%p\n",
 				    __FUNCTION__, task);
 			res = si->dft->lldd_query_task(task);
-			if (res == TMF_RESP_FUNC_SUCC) {
+			switch (res) {
+			case TMF_RESP_FUNC_SUCC:
 				SAS_DPRINTK("%s: task 0x%p at LU\n",
 					    __FUNCTION__, task);
 				return TASK_IS_AT_LU;
-			} else if (res == TMF_RESP_FUNC_COMPLETE) {
+			case TMF_RESP_FUNC_COMPLETE:
 				SAS_DPRINTK("%s: task 0x%p not at LU\n",
 					    __FUNCTION__, task);
 				return TASK_IS_NOT_AT_LU;
-			}
+			case TMF_RESP_FUNC_FAILED:
+                                SAS_DPRINTK("%s: task 0x%p failed to abort\n",
+                                                __FUNCTION__, task);
+                                return TASK_ABORT_FAILED;
+                        }
+
 		}
 	}
 	return res;
@@ -475,6 +482,7 @@ Again:
 			}
 			/* fallthrough */
 		case TASK_IS_NOT_AT_LU:
+		case TASK_ABORT_FAILED:
 			SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
 				    task);
 			tmf_resp = sas_recover_I_T(task->dev);