vsock: cancel connect packets when failing to connect

Hi David,

These patchsets were sent before and reviewed by Stefan and Jorgen [https://www.spinics.net/lists/kvm/msg142367.html].
If there is any blocker, please do tell and I'll see to it. Thanks!

Currently, if a connect call fails on a signal or timeout (e.g., guest is still in the process of starting up), we'll just return to caller and leave the connect packet queued and they are sent even though the connection is considered a failure, which can confuse applications with unwanted false connect attempt.

The patchset enables vsock (both host and guest) to cancel queued packets when a connect attempt is considered to fail.

v4 changelog:
- drop two unnecessary void * cast
- update new callback comment
v3 changelog:
- define cancel_pkt callback in struct vsock_transport rather than struct virtio_transport
- rename virtio_vsock_pkt->vsk to virtio_vsock_pkt->cancel_token
v2 changelog:
- fix queued_replies counting and resume tx/rx when necessary

Cheers,
Tao

Peng Tao (4):
vsock: track pkt owner vsock
vhost-vsock: add pkt cancel capability
vsock: add pkt cancel capability
vsock: cancel packets when failing to connect

 drivers/vhost/vsock.c                   | 41 ++++++++++++++++++++++++++++++++
 include/linux/virtio_vsock.h            |  2 ++
 include/net/af_vsock.h                  |  3 +++
 net/vmw_vsock/af_vsock.c                | 14 +++++++++++
 net/vmw_vsock/virtio_transport.c        | 42 +++++++++++++++++++++++++++++++++
 net/vmw_vsock/virtio_transport_common.c |  7 ++++++
 6 files changed, 109 insertions(+)

2.7.4