From: Stefano Garzarella sgarzare@redhat.com
[ Upstream commit 17dd1367389cfe7f150790c83247b68e0c19d106 ]
Before to call vdev->config->reset(vdev) we need to be sure that no one is accessing the device, for this reason, we add new variables in the struct virtio_vsock to stop the workers during the .remove().
This patch also add few comments before vdev->config->reset(vdev) and vdev->config->del_vqs(vdev).
Suggested-by: Stefan Hajnoczi stefanha@redhat.com Suggested-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/vmw_vsock/virtio_transport.c | 46 +++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 32ad7cfa5fa74..67aba63b5c96d 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -39,6 +39,7 @@ struct virtio_vsock { * must be accessed with tx_lock held. */ struct mutex tx_lock; + bool tx_run;
struct work_struct send_pkt_work; spinlock_t send_pkt_list_lock; @@ -50,6 +51,7 @@ struct virtio_vsock { * must be accessed with rx_lock held. */ struct mutex rx_lock; + bool rx_run; int rx_buf_nr; int rx_buf_max_nr;
@@ -57,6 +59,7 @@ struct virtio_vsock { * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held. */ struct mutex event_lock; + bool event_run; struct virtio_vsock_event event_list[8];
u32 guest_cid; @@ -91,6 +94,9 @@ virtio_transport_send_pkt_work(struct work_struct *work)
mutex_lock(&vsock->tx_lock);
+ if (!vsock->tx_run) + goto out; + vq = vsock->vqs[VSOCK_VQ_TX];
for (;;) { @@ -147,6 +153,7 @@ virtio_transport_send_pkt_work(struct work_struct *work) if (added) virtqueue_kick(vq);
+out: mutex_unlock(&vsock->tx_lock);
if (restart_rx) @@ -230,6 +237,10 @@ static void virtio_transport_tx_work(struct work_struct *work)
vq = vsock->vqs[VSOCK_VQ_TX]; mutex_lock(&vsock->tx_lock); + + if (!vsock->tx_run) + goto out; + do { struct virtio_vsock_pkt *pkt; unsigned int len; @@ -240,6 +251,8 @@ static void virtio_transport_tx_work(struct work_struct *work) added = true; } } while (!virtqueue_enable_cb(vq)); + +out: mutex_unlock(&vsock->tx_lock);
if (added) @@ -268,6 +281,9 @@ static void virtio_transport_rx_work(struct work_struct *work)
mutex_lock(&vsock->rx_lock);
+ if (!vsock->rx_run) + goto out; + do { virtqueue_disable_cb(vq); for (;;) { @@ -376,6 +392,9 @@ static void virtio_transport_event_work(struct work_struct *work)
mutex_lock(&vsock->event_lock);
+ if (!vsock->event_run) + goto out; + do { struct virtio_vsock_event *event; unsigned int len; @@ -390,7 +409,7 @@ static void virtio_transport_event_work(struct work_struct *work) } while (!virtqueue_enable_cb(vq));
virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); - +out: mutex_unlock(&vsock->event_lock); }
@@ -521,12 +540,18 @@ static int virtio_vsock_probe(struct virtio_device *vdev) INIT_WORK(&vsock->event_work, virtio_transport_event_work); INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
+ mutex_lock(&vsock->tx_lock); + vsock->tx_run = true; + mutex_unlock(&vsock->tx_lock); + mutex_lock(&vsock->rx_lock); virtio_vsock_rx_fill(vsock); + vsock->rx_run = true; mutex_unlock(&vsock->rx_lock);
mutex_lock(&vsock->event_lock); virtio_vsock_event_fill(vsock); + vsock->event_run = true; mutex_unlock(&vsock->event_lock);
vdev->priv = vsock; @@ -560,6 +585,24 @@ static void virtio_vsock_remove(struct virtio_device *vdev) /* Reset all connected sockets when the device disappear */ vsock_for_each_connected_socket(virtio_vsock_reset_sock);
+ /* Stop all work handlers to make sure no one is accessing the device, + * so we can safely call vdev->config->reset(). + */ + mutex_lock(&vsock->rx_lock); + vsock->rx_run = false; + mutex_unlock(&vsock->rx_lock); + + mutex_lock(&vsock->tx_lock); + vsock->tx_run = false; + mutex_unlock(&vsock->tx_lock); + + mutex_lock(&vsock->event_lock); + vsock->event_run = false; + mutex_unlock(&vsock->event_lock); + + /* Flush all device writes and interrupts, device will not use any + * more buffers. + */ vdev->config->reset(vdev);
mutex_lock(&vsock->rx_lock); @@ -581,6 +624,7 @@ static void virtio_vsock_remove(struct virtio_device *vdev) } spin_unlock_bh(&vsock->send_pkt_list_lock);
+ /* Delete virtqueues and flush outstanding callbacks if any */ vdev->config->del_vqs(vdev);
mutex_unlock(&the_virtio_vsock_mutex);