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Message-Id: <20201005142109.015282314@linuxfoundation.org>
Date: Mon, 5 Oct 2020 17:26:24 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Stefan Hajnoczi <stefanha@...hat.com>,
"Michael S. Tsirkin" <mst@...hat.com>,
Stefano Garzarella <sgarzare@...hat.com>,
"David S. Miller" <davem@...emloft.net>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 07/38] vsock/virtio: stop workers during the .remove()
From: Stefano Garzarella <sgarzare@...hat.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@...hat.com>
Suggested-by: Michael S. Tsirkin <mst@...hat.com>
Signed-off-by: Stefano Garzarella <sgarzare@...hat.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
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 68186419c445f..4bc217ef56945 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;
@@ -54,6 +55,7 @@ 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;
@@ -61,6 +63,7 @@ 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;
@@ -95,6 +98,10 @@ 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;
@@ -103,6 +110,7 @@ static void virtio_transport_loopback_work(struct work_struct *work)
virtio_transport_recv_pkt(pkt);
}
+out:
mutex_unlock(&vsock->rx_lock);
}
@@ -131,6 +139,9 @@ 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 (;;) {
@@ -189,6 +200,7 @@ virtio_transport_send_pkt_work(struct work_struct *work)
if (added)
virtqueue_kick(vq);
+out:
mutex_unlock(&vsock->tx_lock);
if (restart_rx)
@@ -324,6 +336,10 @@ 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;
@@ -334,6 +350,8 @@ 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)
@@ -362,6 +380,9 @@ 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 (;;) {
@@ -471,6 +492,9 @@ 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;
@@ -485,7 +509,7 @@ 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);
}
@@ -621,12 +645,18 @@ 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;
@@ -661,6 +691,24 @@ 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);
@@ -691,6 +739,7 @@ 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);
--
2.25.1
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