[PATCH 4.9 015/104] vhost-vsock: add pkt cancel capability

From: Greg Kroah-Hartman
Date: Fri Dec 22 2017 - 03:53:38 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Peng Tao <bergwolf@xxxxxxxxx>


[ Upstream commit 16320f363ae128d9b9c70e60f00f2a572f57c23d ]

To allow canceling all packets of a connection.

Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Reviewed-by: Jorgen Hansen <jhansen@xxxxxxxxxx>
Signed-off-by: Peng Tao <bergwolf@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vhost/vsock.c | 41 +++++++++++++++++++++++++++++++++++++++++
include/net/af_vsock.h | 3 +++
2 files changed, 44 insertions(+)

--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -218,6 +218,46 @@ vhost_transport_send_pkt(struct virtio_v
return len;
}

+static int
+vhost_transport_cancel_pkt(struct vsock_sock *vsk)
+{
+ struct vhost_vsock *vsock;
+ struct virtio_vsock_pkt *pkt, *n;
+ int cnt = 0;
+ LIST_HEAD(freeme);
+
+ /* Find the vhost_vsock according to guest context id */
+ vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
+ if (!vsock)
+ return -ENODEV;
+
+ spin_lock_bh(&vsock->send_pkt_list_lock);
+ list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
+ if (pkt->vsk != vsk)
+ continue;
+ list_move(&pkt->list, &freeme);
+ }
+ spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+ list_for_each_entry_safe(pkt, n, &freeme, list) {
+ if (pkt->reply)
+ cnt++;
+ list_del(&pkt->list);
+ virtio_transport_free_pkt(pkt);
+ }
+
+ if (cnt) {
+ struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
+ int new_cnt;
+
+ new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
+ if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num)
+ vhost_poll_queue(&tx_vq->poll);
+ }
+
+ return 0;
+}
+
static struct virtio_vsock_pkt *
vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
unsigned int out, unsigned int in)
@@ -669,6 +709,7 @@ static struct virtio_transport vhost_tra
.release = virtio_transport_release,
.connect = virtio_transport_connect,
.shutdown = virtio_transport_shutdown,
+ .cancel_pkt = vhost_transport_cancel_pkt,

.dgram_enqueue = virtio_transport_dgram_enqueue,
.dgram_dequeue = virtio_transport_dgram_dequeue,
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -100,6 +100,9 @@ struct vsock_transport {
void (*destruct)(struct vsock_sock *);
void (*release)(struct vsock_sock *);

+ /* Cancel all pending packets sent on vsock. */
+ int (*cancel_pkt)(struct vsock_sock *vsk);
+
/* Connections. */
int (*connect)(struct vsock_sock *);