1 files changed, 77 insertions, 31 deletions

diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index a827547aa102..982a8dc49e03 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -35,6 +35,9 @@
 /* The MTU is 16KB per the host side's design */
 #define HVS_MTU_SIZE		(1024 * 16)
 
+/* How long to wait for graceful shutdown of a connection */
+#define HVS_CLOSE_TIMEOUT (8 * HZ)
+
 struct vmpipe_proto_header {
 	u32 pkt_type;
 	u32 data_size;
@@ -305,19 +308,32 @@ static void hvs_channel_cb(void *ctx)
 		sk->sk_write_space(sk);
 }
 
-static void hvs_close_connection(struct vmbus_channel *chan)
+static void hvs_do_close_lock_held(struct vsock_sock *vsk,
+				   bool cancel_timeout)
 {
-	struct sock *sk = get_per_channel_state(chan);
-	struct vsock_sock *vsk = vsock_sk(sk);
-
-	lock_sock(sk);
+	struct sock *sk = sk_vsock(vsk);
 
-	sk->sk_state = TCP_CLOSE;
 	sock_set_flag(sk, SOCK_DONE);
-	vsk->peer_shutdown |= SEND_SHUTDOWN | RCV_SHUTDOWN;
-
+	vsk->peer_shutdown = SHUTDOWN_MASK;
+	if (vsock_stream_has_data(vsk) <= 0)
+		sk->sk_state = TCP_CLOSING;
 	sk->sk_state_change(sk);
+	if (vsk->close_work_scheduled &&
+	    (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
+		vsk->close_work_scheduled = false;
+		vsock_remove_sock(vsk);
 
+		/* Release the reference taken while scheduling the timeout */
+		sock_put(sk);
+	}
+}
+
+static void hvs_close_connection(struct vmbus_channel *chan)
+{
+	struct sock *sk = get_per_channel_state(chan);
+
+	lock_sock(sk);
+	hvs_do_close_lock_held(vsock_sk(sk), true);
 	release_sock(sk);
 }
 
@@ -452,50 +468,80 @@ static int hvs_connect(struct vsock_sock *vsk)
 	return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id);
 }
 
+static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode)
+{
+	struct vmpipe_proto_header hdr;
+
+	if (hvs->fin_sent || !hvs->chan)
+		return;
+
+	/* It can't fail: see hvs_channel_writable_bytes(). */
+	(void)hvs_send_data(hvs->chan, (struct hvs_send_buf *)&hdr, 0);
+	hvs->fin_sent = true;
+}
+
 static int hvs_shutdown(struct vsock_sock *vsk, int mode)
 {
 	struct sock *sk = sk_vsock(vsk);
-	struct vmpipe_proto_header hdr;
-	struct hvs_send_buf *send_buf;
-	struct hvsock *hvs;
 
 	if (!(mode & SEND_SHUTDOWN))
 		return 0;
 
 	lock_sock(sk);
+	hvs_shutdown_lock_held(vsk->trans, mode);
+	release_sock(sk);
+	return 0;
+}
 
-	hvs = vsk->trans;
-	if (hvs->fin_sent)
-		goto out;
-
-	send_buf = (struct hvs_send_buf *)&hdr;
+static void hvs_close_timeout(struct work_struct *work)
+{
+	struct vsock_sock *vsk =
+		container_of(work, struct vsock_sock, close_work.work);
+	struct sock *sk = sk_vsock(vsk);
 
-	/* It can't fail: see hvs_channel_writable_bytes(). */
-	(void)hvs_send_data(hvs->chan, send_buf, 0);
+	sock_hold(sk);
+	lock_sock(sk);
+	if (!sock_flag(sk, SOCK_DONE))
+		hvs_do_close_lock_held(vsk, false);
 
-	hvs->fin_sent = true;
-out:
+	vsk->close_work_scheduled = false;
 	release_sock(sk);
-	return 0;
+	sock_put(sk);
 }
 
-static void hvs_release(struct vsock_sock *vsk)
+/* Returns true, if it is safe to remove socket; false otherwise */
+static bool hvs_close_lock_held(struct vsock_sock *vsk)
 {
 	struct sock *sk = sk_vsock(vsk);
-	struct hvsock *hvs = vsk->trans;
-	struct vmbus_channel *chan;
 
-	lock_sock(sk);
+	if (!(sk->sk_state == TCP_ESTABLISHED ||
+	      sk->sk_state == TCP_CLOSING))
+		return true;
 
-	sk->sk_state = TCP_CLOSING;
-	vsock_remove_sock(vsk);
+	if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
+		hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK);
 
-	release_sock(sk);
+	if (sock_flag(sk, SOCK_DONE))
+		return true;
 
-	chan = hvs->chan;
-	if (chan)
-		hvs_shutdown(vsk, RCV_SHUTDOWN | SEND_SHUTDOWN);
+	/* This reference will be dropped by the delayed close routine */
+	sock_hold(sk);
+	INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout);
+	vsk->close_work_scheduled = true;
+	schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT);
+	return false;
+}
 
+static void hvs_release(struct vsock_sock *vsk)
+{
+	struct sock *sk = sk_vsock(vsk);
+	bool remove_sock;
+
+	lock_sock(sk);
+	remove_sock = hvs_close_lock_held(vsk);
+	release_sock(sk);
+	if (remove_sock)
+		vsock_remove_sock(vsk);
 }
 
 static void hvs_destruct(struct vsock_sock *vsk)