SUNRPC: Add tracking of RPC level errors

Add variables to track RPC level errors so that we can distinguish
between issue that arose in the RPC transport layer as opposed to
those arising from the reply message.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

include/linux/sunrpc/sched.h

@@ -61,6 +61,8 @@ struct rpc_task {
 		struct rpc_wait		tk_wait;	/* RPC wait */
 	} u;
 
+	int			tk_rpc_status;	/* Result of last RPC operation */
+
 	/*
 	 * RPC call state
 	 */

net/sunrpc/clnt.c

@@ -1468,6 +1468,7 @@ static int
 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
 {
 	task->tk_status = 0;
+	task->tk_rpc_status = 0;
 	task->tk_action = action;
 	return 1;
 }
@@ -1510,6 +1511,19 @@ const char
 		return "no proc";
 }
 
+static void
+__rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
+{
+	task->tk_rpc_status = rpc_status;
+	rpc_exit(task, tk_status);
+}
+
+static void
+rpc_call_rpcerror(struct rpc_task *task, int status)
+{
+	__rpc_call_rpcerror(task, status, status);
+}
+
 /*
  * 0.  Initial state
  *
@@ -1574,7 +1588,7 @@ call_reserveresult(struct rpc_task *task)
 
 		printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 				__func__, status);
-		rpc_exit(task, -EIO);
+		rpc_call_rpcerror(task, -EIO);
 		return;
 	}
 
@@ -1602,7 +1616,7 @@ call_reserveresult(struct rpc_task *task)
 				__func__, status);
 		break;
 	}
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 }
 
 /*
@@ -1670,7 +1684,7 @@ call_refreshresult(struct rpc_task *task)
 	}
 	dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
 				task->tk_pid, __func__, status);
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 }
 
 /*
@@ -1721,7 +1735,7 @@ call_allocate(struct rpc_task *task)
 	if (status == 0)
 		return;
 	if (status != -ENOMEM) {
-		rpc_exit(task, status);
+		rpc_call_rpcerror(task, status);
 		return;
 	}
 
@@ -1790,7 +1804,7 @@ call_encode(struct rpc_task *task)
 			task->tk_action = call_refresh;
 			break;
 		default:
-			rpc_exit(task, task->tk_status);
+			rpc_call_rpcerror(task, task->tk_status);
 		}
 		return;
 	} else {
@@ -1931,7 +1945,7 @@ call_bind_status(struct rpc_task *task)
 				task->tk_pid, -task->tk_status);
 	}
 
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 	return;
 
 retry_timeout:
@@ -1966,7 +1980,7 @@ call_connect(struct rpc_task *task)
 	if (task->tk_status < 0)
 		return;
 	if (task->tk_flags & RPC_TASK_NOCONNECT) {
-		rpc_exit(task, -ENOTCONN);
+		rpc_call_rpcerror(task, -ENOTCONN);
 		return;
 	}
 	if (!xprt_prepare_transmit(task))
@@ -2026,7 +2040,7 @@ call_connect_status(struct rpc_task *task)
 		task->tk_action = call_transmit;
 		return;
 	}
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 	return;
 out_retry:
 	/* Check for timeouts before looping back to call_bind */
@@ -2111,7 +2125,7 @@ call_transmit_status(struct rpc_task *task)
 			if (!task->tk_msg.rpc_proc->p_proc)
 				trace_xprt_ping(task->tk_xprt,
 						task->tk_status);
-			rpc_exit(task, task->tk_status);
+			rpc_call_rpcerror(task, task->tk_status);
 			return;
 		}
 		/* fall through */
@@ -2275,7 +2289,7 @@ call_status(struct rpc_task *task)
 	rpc_check_timeout(task);
 	return;
 out_exit:
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 }
 
 static bool
@@ -2299,7 +2313,7 @@ rpc_check_timeout(struct rpc_task *task)
 	task->tk_timeouts++;
 
 	if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
-		rpc_exit(task, -ETIMEDOUT);
+		rpc_call_rpcerror(task, -ETIMEDOUT);
 		return;
 	}
 
@@ -2310,9 +2324,9 @@ rpc_check_timeout(struct rpc_task *task)
 				task->tk_xprt->servername);
 		}
 		if (task->tk_flags & RPC_TASK_TIMEOUT)
-			rpc_exit(task, -ETIMEDOUT);
+			rpc_call_rpcerror(task, -ETIMEDOUT);
 		else
-			rpc_exit(task, -EIO);
+			__rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
 		return;
 	}
 

net/sunrpc/xprtsock.c

@@ -2017,6 +2017,7 @@ static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 		 * we'll need to figure out how to pass a namespace to
 		 * connect.
 		 */
+		task->tk_rpc_status = -ENOTCONN;
 		rpc_exit(task, -ENOTCONN);
 		return;
 	}