4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: WANG Cong <xiyou.wangc...@gmail.com>

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 <mkube...@suse.cz>
Cc: Stefan Hajnoczi <stefa...@redhat.com>
Cc: Jorgen Hansen <jhan...@vmware.com>
Cc: "Michael S. Tsirkin" <m...@redhat.com>
Cc: Claudio Imbrenda <imbre...@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Cc: "Jorgen S. Hansen" <jhan...@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 net/vmw_vsock/af_vsock.c |   21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1524,8 +1524,7 @@ static int vsock_stream_sendmsg(struct s
        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 s
        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 s
                        /* 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


Reply via email to