vsock: add API call for data ready

This adds 'vsock_data_ready()' which must be called by transport to kick
sleeping data readers. It checks for SO_RCVLOWAT value before waking
user, thus preventing spurious wake ups. Based on 'tcp_data_ready()' logic.

Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index d609a08..568a87c 100644 (file)
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -78,6 +78,7 @@ struct vsock_sock {
 s64 vsock_stream_has_data(struct vsock_sock *vsk);
 s64 vsock_stream_has_space(struct vsock_sock *vsk);
 struct sock *vsock_create_connected(struct sock *parent);
+void vsock_data_ready(struct sock *sk);
 
 /**** TRANSPORT ****/
 

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 15171ba..ee41870 100644 (file)
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -882,6 +882,16 @@ s64 vsock_stream_has_space(struct vsock_sock *vsk)
 }
 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 
+void vsock_data_ready(struct sock *sk)
+{
+       struct vsock_sock *vsk = vsock_sk(sk);
+
+       if (vsock_stream_has_data(vsk) >= sk->sk_rcvlowat ||
+           sock_flag(sk, SOCK_DONE))
+               sk->sk_data_ready(sk);
+}
+EXPORT_SYMBOL_GPL(vsock_data_ready);
+
 static int vsock_release(struct socket *sock)
 {
        __vsock_release(sock->sk, 0);