This is a note to let you know that I've just added the patch titled

vsock: use new wait API for vsock_stream_sendmsg()

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: vsock-use-new-wait-api-for-vsock_stream_sendmsg.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 499fde662f1957e3cb8d192a94a099ebe19c714b Mon Sep 17 00:00:00 2001

From: WANG Cong xiyou.wangcong@gmail.com Date: Fri, 19 May 2017 11:21:59 -0700 Subject: vsock: use new wait API for vsock_stream_sendmsg()

From: WANG Cong xiyou.wangcong@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 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

--- 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 @@ -1512,8 +1512,7 @@ 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); @@ -1556,11 +1555,10 @@ 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) && @@ -1569,33 +1567,30 @@ 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

Patches currently in stable-queue which might be from xiyou.wangcong@gmail.com are

queue-4.4/vsock-use-new-wait-api-for-vsock_stream_sendmsg.patch queue-4.4/ipv6-only-call-ip6_route_dev_notify-once-for-netdev_unregister.patch