From 17dd1367389cfe7f150790c83247b68e0c19d106 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Fri, 28 Jun 2019 14:36:58 +0200 Subject: [PATCH] vsock/virtio: stop workers during the .remove() 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 Suggested-by: Michael S. Tsirkin Signed-off-by: Stefano Garzarella Signed-off-by: David S. Miller --- net/vmw_vsock/virtio_transport.c | 51 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 50 insertions(+), 1 deletion(-) diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 7ad510e..1b44ec6 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -38,6 +38,7 @@ 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; @@ -53,6 +54,7 @@ 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; @@ -60,6 +62,7 @@ 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; @@ -94,6 +97,10 @@ static void virtio_transport_loopback_work(struct work_struct *work) spin_unlock_bh(&vsock->loopback_list_lock); mutex_lock(&vsock->rx_lock); + + if (!vsock->rx_run) + goto out; + while (!list_empty(&pkts)) { struct virtio_vsock_pkt *pkt; @@ -102,6 +109,7 @@ static void virtio_transport_loopback_work(struct work_struct *work) virtio_transport_recv_pkt(pkt); } +out: mutex_unlock(&vsock->rx_lock); } @@ -130,6 +138,9 @@ 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 (;;) { @@ -188,6 +199,7 @@ virtio_transport_send_pkt_work(struct work_struct *work) if (added) virtqueue_kick(vq); +out: mutex_unlock(&vsock->tx_lock); if (restart_rx) @@ -323,6 +335,10 @@ 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; @@ -333,6 +349,8 @@ 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) @@ -361,6 +379,9 @@ 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 (;;) { @@ -470,6 +491,9 @@ 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; @@ -484,7 +508,7 @@ 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); } @@ -619,12 +643,18 @@ static int virtio_vsock_probe(struct virtio_device *vdev) INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work); INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_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; @@ -659,6 +689,24 @@ 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); @@ -689,6 +737,7 @@ static void virtio_vsock_remove(struct virtio_device *vdev) } spin_unlock_bh(&vsock->loopback_list_lock); + /* Delete virtqueues and flush outstanding callbacks if any */ vdev->config->del_vqs(vdev); mutex_unlock(&the_virtio_vsock_mutex); -- 2.7.4