Re: [PATCH v2 4/4] vsock: cancel packets when failing to connect

On Thu, Dec 8, 2016 at 5:24 PM, Stefan Hajnoczi [off-list ref] wrote:

On Wed, Dec 07, 2016 at 11:14:12PM +0800, Peng Tao wrote:

quoted

Otherwise we'll leave the packets queued until releasing vsock device.
E.g., if guest is slow to start up, resulting ETIMEDOUT on connect, guest
will get the connect requests from failed host sockets.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Peng Tao <redacted>
---
 include/linux/virtio_vsock.h            | 7 +++++++
 net/vmw_vsock/af_vsock.c                | 7 +++++++
 net/vmw_vsock/virtio_transport_common.c | 7 -------
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index b92e88d..ff6850a 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h

@@ -156,4 +156,11 @@ void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vs
 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted);
 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit);

+static inline const struct virtio_transport *virtio_transport_get_ops(void)
+{
+     const struct vsock_transport *t = vsock_core_get_transport();
+
+     return container_of(t, struct virtio_transport, transport);
+}
+
 #endif /* _LINUX_VIRTIO_VSOCK_H */

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 8a398b3..ebb50d6 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c

@@ -104,6 +104,7 @@
 #include <linux/unistd.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
+#include <linux/virtio_vsock.h>
 #include <net/sock.h>
 #include <net/af_vsock.h>

@@ -1105,6 +1106,7 @@ static void vsock_connect_timeout(struct work_struct *work)
 {
      struct sock *sk;
      struct vsock_sock *vsk;
+     int cancel = 0;

      vsk = container_of(work, struct vsock_sock, dwork.work);
      sk = sk_vsock(vsk);

@@ -1115,8 +1117,11 @@ static void vsock_connect_timeout(struct work_struct *work)
              sk->sk_state = SS_UNCONNECTED;
              sk->sk_err = ETIMEDOUT;
              sk->sk_error_report(sk);
+             cancel = 1;
      }
      release_sock(sk);
+     if (cancel)
+             virtio_transport_get_ops()->cancel_pkt(vsk);

This doesn't work with the VMCI transport.  Remember af_vsock.c is
common code shared by all transports.

You need to add a struct vsock_transport->cancel_pkt() callback instead
os a struct virtio_transport->cancel_pkt() callback.  And you need to
handle the case where cancel_pkt == NULL if you don't implement it for
VMCI.

I see. Thanks for reviewing! I'll fix it and resend later.

Cheers,
Tao