[PATCH v3 11/29] SUNRPC: Add tracking of RPC level errors

[Trond Myklebust <trondmy@gmail.com>]

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>
---
 include/linux/sunrpc/sched.h |  2 ++
 net/sunrpc/clnt.c            | 40 ++++++++++++++++++++++++------------
 net/sunrpc/xprtsock.c        |  1 +
 3 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index c41f5f498b3b..f01990c6423d 100644
--- a/include/linux/sunrpc/sched.h
+++ b/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
 	 */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 3ab743c0e888..a9e5e81c67be 100644
--- a/net/sunrpc/clnt.c
+++ b/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
  *
@@ -1579,7 +1593,7 @@ 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;
 	}
 
@@ -1608,7 +1622,7 @@ call_reserveresult(struct rpc_task *task)
 				__func__, status);
 		break;
 	}
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 }
 
 /*
@@ -1684,7 +1698,7 @@ 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);
 }
 
 /*
@@ -1741,7 +1755,7 @@ call_allocate(struct rpc_task *task)
 		return;
 	}
 	if (status != -ENOMEM) {
-		rpc_exit(task, status);
+		rpc_call_rpcerror(task, status);
 		return;
 	}
 
@@ -1810,7 +1824,7 @@ 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 {
@@ -1950,7 +1964,7 @@ 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:
@@ -1986,7 +2000,7 @@ 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))
@@ -2047,7 +2061,7 @@ call_connect_status(struct rpc_task *task)
 		call_transmit(task);
 		return;
 	}
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 	return;
 out_retry:
 	/* Check for timeouts before looping back to call_bind */
@@ -2138,7 +2152,7 @@ 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 */
@@ -2301,7 +2315,7 @@ call_status(struct rpc_task *task)
 	rpc_check_timeout(task);
 	return;
 out_exit:
-	rpc_exit(task, status);
+	rpc_call_rpcerror(task, status);
 }
 
 static bool
@@ -2325,7 +2339,7 @@ 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;
 	}
 
@@ -2336,9 +2350,9 @@ 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;
 	}
 
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index b4b4b8db143c..c69951ed2ebc 100644
--- a/net/sunrpc/xprtsock.c
+++ b/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;
 	}
-- 
2.20.1