Merge tag 'nfs-for-4.20-6' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:

 - Fix TCP socket disconnection races by ensuring we always call
   xprt_disconnect_done() after releasing the socket.

 - Fix a race when clearing both XPRT_CONNECTING and XPRT_LOCKED

 - Remove xprt_connect_status() so it does not mask errors that should
   be handled by call_connect_status()

* tag 'nfs-for-4.20-6' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Remove xprt_connect_status()
  SUNRPC: Fix a race with XPRT_CONNECTING
  SUNRPC: Fix disconnection races

net/sunrpc/clnt.c

@@ -1952,6 +1952,7 @@ call_connect_status(struct rpc_task *task)
 		/* retry with existing socket, after a delay */
 		rpc_delay(task, 3*HZ);
 		/* fall through */
+	case -ENOTCONN:
 	case -EAGAIN:
 		/* Check for timeouts before looping back to call_bind */
 	case -ETIMEDOUT:

net/sunrpc/xprt.c

@@ -67,7 +67,6 @@
  */
 static void	 xprt_init(struct rpc_xprt *xprt, struct net *net);
 static __be32	xprt_alloc_xid(struct rpc_xprt *xprt);
-static void	xprt_connect_status(struct rpc_task *task);
 static void	 xprt_destroy(struct rpc_xprt *xprt);
 
 static DEFINE_SPINLOCK(xprt_list_lock);
@@ -680,7 +679,9 @@ void xprt_force_disconnect(struct rpc_xprt *xprt)
 	/* Try to schedule an autoclose RPC call */
 	if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
 		queue_work(xprtiod_workqueue, &xprt->task_cleanup);
-	xprt_wake_pending_tasks(xprt, -EAGAIN);
+	else if (xprt->snd_task)
+		rpc_wake_up_queued_task_set_status(&xprt->pending,
+				xprt->snd_task, -ENOTCONN);
 	spin_unlock_bh(&xprt->transport_lock);
 }
 EXPORT_SYMBOL_GPL(xprt_force_disconnect);
@@ -820,7 +821,7 @@ void xprt_connect(struct rpc_task *task)
 	if (!xprt_connected(xprt)) {
 		task->tk_timeout = task->tk_rqstp->rq_timeout;
 		task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie;
-		rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
+		rpc_sleep_on(&xprt->pending, task, NULL);
 
 		if (test_bit(XPRT_CLOSING, &xprt->state))
 			return;
@@ -839,34 +840,6 @@ void xprt_connect(struct rpc_task *task)
 	xprt_release_write(xprt, task);
 }
 
-static void xprt_connect_status(struct rpc_task *task)
-{
-	switch (task->tk_status) {
-	case 0:
-		dprintk("RPC: %5u xprt_connect_status: connection established\n",
-				task->tk_pid);
-		break;
-	case -ECONNREFUSED:
-	case -ECONNRESET:
-	case -ECONNABORTED:
-	case -ENETUNREACH:
-	case -EHOSTUNREACH:
-	case -EPIPE:
-	case -EAGAIN:
-		dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
-		break;
-	case -ETIMEDOUT:
-		dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
-				"out\n", task->tk_pid);
-		break;
-	default:
-		dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
-				"server %s\n", task->tk_pid, -task->tk_status,
-				task->tk_rqstp->rq_xprt->servername);
-		task->tk_status = -EIO;
-	}
-}
-
 enum xprt_xid_rb_cmp {
 	XID_RB_EQUAL,
 	XID_RB_LEFT,

net/sunrpc/xprtsock.c

@@ -1217,6 +1217,8 @@ static void xs_reset_transport(struct sock_xprt *transport)
 
 	trace_rpc_socket_close(xprt, sock);
 	sock_release(sock);
+
+	xprt_disconnect_done(xprt);
 }
 
 /**
@@ -1237,8 +1239,6 @@ static void xs_close(struct rpc_xprt *xprt)
 
 	xs_reset_transport(transport);
 	xprt->reestablish_timeout = 0;
-
-	xprt_disconnect_done(xprt);
 }
 
 static void xs_inject_disconnect(struct rpc_xprt *xprt)
@@ -1489,8 +1489,6 @@ static void xs_tcp_state_change(struct sock *sk)
 					&transport->sock_state))
 			xprt_clear_connecting(xprt);
 		clear_bit(XPRT_CLOSING, &xprt->state);
-		if (sk->sk_err)
-			xprt_wake_pending_tasks(xprt, -sk->sk_err);
 		/* Trigger the socket release */
 		xs_tcp_force_close(xprt);
 	}
@@ -2092,8 +2090,8 @@ static void xs_udp_setup_socket(struct work_struct *work)
 	trace_rpc_socket_connect(xprt, sock, 0);
 	status = 0;
 out:
-	xprt_unlock_connect(xprt, transport);
 	xprt_clear_connecting(xprt);
+	xprt_unlock_connect(xprt, transport);
 	xprt_wake_pending_tasks(xprt, status);
 }
 
@@ -2329,8 +2327,8 @@ static void xs_tcp_setup_socket(struct work_struct *work)
 	}
 	status = -EAGAIN;
 out:
-	xprt_unlock_connect(xprt, transport);
 	xprt_clear_connecting(xprt);
+	xprt_unlock_connect(xprt, transport);
 	xprt_wake_pending_tasks(xprt, status);
 }