From d6c52dda2c08eb74a92c722fa2655f5447161db7 Mon Sep 17 00:00:00 2001
From: WANG Cong <xiyou.wangcong@gmail.com>
Date: Fri, 19 May 2017 11:21:59 -0700
Subject: [PATCH] UPSTREAM: 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>

(cherry picked from commit 6be6e48daabc18858a0a5a9d18fbd399714fc9e4)
Bug: 121166534
Test: Ran cuttlefish with android-4.4 + vsock adb tunnel
Signed-off-by: Cody Schuffelen <schuffelen@google.com>
Change-Id: Ie0ac0685071c2034c9565e2554ff5e41f6cfd619
---
 net/vmw_vsock/af_vsock.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 7e3c04eb01ee..7566395e526d 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1585,7 +1585,7 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 	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) &&
@@ -1594,13 +1594,13 @@ 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;
 			}
 
@@ -1609,15 +1609,15 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 			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;
 			}
 		}
-		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