From 844e3cded9c8665e95b1e43b707a6c3adcbc901f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?=
 <emulatorman@parabola.nu>
Date: Sun, 28 Feb 2016 05:29:16 -0300
Subject: Linux-libre 4.4.3-gnu

---
 net/sunrpc/xprtsock.c | 49 +++++++++++++++++++++----------------------------
 1 file changed, 21 insertions(+), 28 deletions(-)

(limited to 'net/sunrpc/xprtsock.c')

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 2ffaf6a79..027c9ef8a 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -398,7 +398,6 @@ static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen,
 	if (unlikely(!sock))
 		return -ENOTSOCK;
 
-	clear_bit(SOCKWQ_ASYNC_NOSPACE, &sock->flags);
 	if (base != 0) {
 		addr = NULL;
 		addrlen = 0;
@@ -442,7 +441,6 @@ static void xs_nospace_callback(struct rpc_task *task)
 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 
 	transport->inet->sk_write_pending--;
-	clear_bit(SOCKWQ_ASYNC_NOSPACE, &transport->sock->flags);
 }
 
 /**
@@ -467,20 +465,11 @@ static int xs_nospace(struct rpc_task *task)
 
 	/* Don't race with disconnect */
 	if (xprt_connected(xprt)) {
-		if (test_bit(SOCKWQ_ASYNC_NOSPACE, &transport->sock->flags)) {
-			/*
-			 * Notify TCP that we're limited by the application
-			 * window size
-			 */
-			set_bit(SOCK_NOSPACE, &transport->sock->flags);
-			sk->sk_write_pending++;
-			/* ...and wait for more buffer space */
-			xprt_wait_for_buffer_space(task, xs_nospace_callback);
-		}
-	} else {
-		clear_bit(SOCKWQ_ASYNC_NOSPACE, &transport->sock->flags);
+		/* wait for more buffer space */
+		sk->sk_write_pending++;
+		xprt_wait_for_buffer_space(task, xs_nospace_callback);
+	} else
 		ret = -ENOTCONN;
-	}
 
 	spin_unlock_bh(&xprt->transport_lock);
 
@@ -616,9 +605,6 @@ process_status:
 	case -EAGAIN:
 		status = xs_nospace(task);
 		break;
-	default:
-		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
-			-status);
 	case -ENETUNREACH:
 	case -ENOBUFS:
 	case -EPIPE:
@@ -626,7 +612,10 @@ process_status:
 	case -EPERM:
 		/* When the server has died, an ICMP port unreachable message
 		 * prompts ECONNREFUSED. */
-		clear_bit(SOCKWQ_ASYNC_NOSPACE, &transport->sock->flags);
+		break;
+	default:
+		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
+			-status);
 	}
 
 	return status;
@@ -706,16 +695,16 @@ static int xs_tcp_send_request(struct rpc_task *task)
 	case -EAGAIN:
 		status = xs_nospace(task);
 		break;
-	default:
-		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
-			-status);
 	case -ECONNRESET:
 	case -ECONNREFUSED:
 	case -ENOTCONN:
 	case -EADDRINUSE:
 	case -ENOBUFS:
 	case -EPIPE:
-		clear_bit(SOCKWQ_ASYNC_NOSPACE, &transport->sock->flags);
+		break;
+	default:
+		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
+			-status);
 	}
 
 	return status;
@@ -1609,19 +1598,23 @@ static void xs_tcp_state_change(struct sock *sk)
 
 static void xs_write_space(struct sock *sk)
 {
-	struct socket *sock;
+	struct socket_wq *wq;
 	struct rpc_xprt *xprt;
 
-	if (unlikely(!(sock = sk->sk_socket)))
+	if (!sk->sk_socket)
 		return;
-	clear_bit(SOCK_NOSPACE, &sock->flags);
+	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 
 	if (unlikely(!(xprt = xprt_from_sock(sk))))
 		return;
-	if (test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sock->flags) == 0)
-		return;
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
+		goto out;
 
 	xprt_write_space(xprt);
+out:
+	rcu_read_unlock();
 }
 
 /**
-- 
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