From: WANG Cong <xiyou.wangcong@gmail.com>
Date: Fri, 19 May 2017 18:21:59 +0000 (-0700)
Subject: vsock: use new wait API for vsock_stream_sendmsg()
X-Git-Tag: archive/raspbian/4.9.80-2+rpi1~7^2~1203
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=6be6e48daabc18858a0a5a9d18fbd399714fc9e4;p=linux-4.9.git

vsock: use new wait API for vsock_stream_sendmsg()

commit 499fde662f1957e3cb8d192a94a099ebe19c714b upstream.

As reported by Michal, vsock_stream_sendmsg() could still
sleep at vsock_stream_has_space() after prepare_to_wait():

  vsock_stream_has_space
    vmci_transport_stream_has_space
      vmci_qpair_produce_free_space
        qp_lock
          qp_acquire_queue_mutex
            mutex_lock

Just switch to the new wait API like we did for commit
d9dc8b0f8b4e ("net: fix sleeping for sk_wait_event()").

Reported-by: Michal Kubecek <mkubecek@suse.cz>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: "Jorgen S. Hansen" <jhansen@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 8a398b3fb532..2f633eec6b7a 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1524,8 +1524,7 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 	long timeout;
 	int err;
 	struct vsock_transport_send_notify_data send_data;
-
-	DEFINE_WAIT(wait);
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 
 	sk = sock->sk;
 	vsk = vsock_sk(sk);
@@ -1568,11 +1567,10 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 	if (err < 0)
 		goto out;
 
-
 	while (total_written < len) {
 		ssize_t written;
 
-		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+		add_wait_queue(sk_sleep(sk), &wait);
 		while (vsock_stream_has_space(vsk) == 0 &&
 		       sk->sk_err == 0 &&
 		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
@@ -1581,33 +1579,30 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 			/* Don't wait for non-blocking sockets. */
 			if (timeout == 0) {
 				err = -EAGAIN;
-				finish_wait(sk_sleep(sk), &wait);
+				remove_wait_queue(sk_sleep(sk), &wait);
 				goto out_err;
 			}
 
 			err = transport->notify_send_pre_block(vsk, &send_data);
 			if (err < 0) {
-				finish_wait(sk_sleep(sk), &wait);
+				remove_wait_queue(sk_sleep(sk), &wait);
 				goto out_err;
 			}
 
 			release_sock(sk);
-			timeout = schedule_timeout(timeout);
+			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
 			lock_sock(sk);
 			if (signal_pending(current)) {
 				err = sock_intr_errno(timeout);
-				finish_wait(sk_sleep(sk), &wait);
+				remove_wait_queue(sk_sleep(sk), &wait);
 				goto out_err;
 			} else if (timeout == 0) {
 				err = -EAGAIN;
-				finish_wait(sk_sleep(sk), &wait);
+				remove_wait_queue(sk_sleep(sk), &wait);
 				goto out_err;
 			}
-
-			prepare_to_wait(sk_sleep(sk), &wait,
-					TASK_INTERRUPTIBLE);
 		}
-		finish_wait(sk_sleep(sk), &wait);
+		remove_wait_queue(sk_sleep(sk), &wait);
 
 		/* These checks occur both as part of and after the loop
 		 * conditional since we need to check before and after