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Commit 499fde66 authored by WANG Cong's avatar WANG Cong Committed by David S. Miller
Browse files

vsock: use new wait API for vsock_stream_sendmsg() 



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
d9dc8b0f ("net: fix sleeping for sk_wait_event()").

Reported-by: default avatarMichal 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: default avatarCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 72ccc471

net/vmw_vsock/af_vsock.c

+8 −13
Original line number Diff line number Diff line
@@ -1540,8 +1540,7 @@ 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);
@@ -1584,11 +1583,10 @@ 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) &&
@@ -1597,33 +1595,30 @@ 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