VSOCK: defer sock removal to transports

The virtio transport will implement graceful shutdown and the related
SO_LINGER socket option.  This requires orphaning the sock but keeping
it in the table of connections after .release().

This patch adds the vsock_remove_sock() function and leaves it up to the
transport when to remove the sock.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index e34d96f..17dbbe6 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -344,6 +344,16 @@
 	return ret;
 }
 
+void vsock_remove_sock(struct vsock_sock *vsk)
+{
+	if (vsock_in_bound_table(vsk))
+		vsock_remove_bound(vsk);
+
+	if (vsock_in_connected_table(vsk))
+		vsock_remove_connected(vsk);
+}
+EXPORT_SYMBOL_GPL(vsock_remove_sock);
+
 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
 {
 	int i;
@@ -660,12 +670,6 @@
 		vsk = vsock_sk(sk);
 		pending = NULL;	/* Compiler warning. */
 
-		if (vsock_in_bound_table(vsk))
-			vsock_remove_bound(vsk);
-
-		if (vsock_in_connected_table(vsk))
-			vsock_remove_connected(vsk);
-
 		transport->release(vsk);
 
 		lock_sock(sk);