Merge branch 'vhost_net-ptr_ring-fixes'

Jason Wang says:

====================
Several fixes for vhost_net ptr_ring usage

This small series try to fix several bugs of ptr_ring usage in
vhost_net. Please review.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/tun.c

@@ -655,7 +655,7 @@ static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
 	return tun;
 }
 
-static void tun_ptr_free(void *ptr)
+void tun_ptr_free(void *ptr)
 {
 	if (!ptr)
 		return;
@@ -667,6 +667,7 @@ static void tun_ptr_free(void *ptr)
 		__skb_array_destroy_skb(ptr);
 	}
 }
+EXPORT_SYMBOL_GPL(tun_ptr_free);
 
 static void tun_queue_purge(struct tun_file *tfile)
 {

drivers/vhost/net.c

@@ -170,7 +170,7 @@ static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq)
 	if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) {
 		ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head,
 				   vhost_net_buf_get_size(rxq),
-				   __skb_array_destroy_skb);
+				   tun_ptr_free);
 		rxq->head = rxq->tail = 0;
 	}
 }
@@ -948,6 +948,7 @@ static int vhost_net_open(struct inode *inode, struct file *f)
 		n->vqs[i].done_idx = 0;
 		n->vqs[i].vhost_hlen = 0;
 		n->vqs[i].sock_hlen = 0;
+		n->vqs[i].rx_ring = NULL;
 		vhost_net_buf_init(&n->vqs[i].rxq);
 	}
 	vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
@@ -972,6 +973,7 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
 	vhost_net_disable_vq(n, vq);
 	vq->private_data = NULL;
 	vhost_net_buf_unproduce(nvq);
+	nvq->rx_ring = NULL;
 	mutex_unlock(&vq->mutex);
 	return sock;
 }
@@ -1161,14 +1163,14 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 		vhost_net_disable_vq(n, vq);
 		vq->private_data = sock;
 		vhost_net_buf_unproduce(nvq);
-		if (index == VHOST_NET_VQ_RX)
-			nvq->rx_ring = get_tap_ptr_ring(fd);
 		r = vhost_vq_init_access(vq);
 		if (r)
 			goto err_used;
 		r = vhost_net_enable_vq(n, vq);
 		if (r)
 			goto err_used;
+		if (index == VHOST_NET_VQ_RX)
+			nvq->rx_ring = get_tap_ptr_ring(fd);
 
 		oldubufs = nvq->ubufs;
 		nvq->ubufs = ubufs;

include/linux/if_tun.h

@@ -25,6 +25,7 @@ struct ptr_ring *tun_get_tx_ring(struct file *file);
 bool tun_is_xdp_buff(void *ptr);
 void *tun_xdp_to_ptr(void *ptr);
 void *tun_ptr_to_xdp(void *ptr);
+void tun_ptr_free(void *ptr);
 #else
 #include <linux/err.h>
 #include <linux/errno.h>
@@ -50,5 +51,8 @@ static inline void *tun_ptr_to_xdp(void *ptr)
 {
 	return NULL;
 }
+static inline void tun_ptr_free(void *ptr)
+{
+}
 #endif /* CONFIG_TUN */
 #endif /* __IF_TUN_H */