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-rw-r--r--drivers/net/xen-netback/interface.c26
-rw-r--r--drivers/net/xen-netback/netback.c2
-rw-r--r--drivers/net/xen-netback/xenbus.c20
3 files changed, 28 insertions, 20 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 829b26cd4549..8397f6c92451 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -165,13 +165,17 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct xenvif *vif = netdev_priv(dev);
struct xenvif_queue *queue = NULL;
- unsigned int num_queues = vif->num_queues;
+ unsigned int num_queues;
u16 index;
struct xenvif_rx_cb *cb;
BUG_ON(skb->dev != dev);
- /* Drop the packet if queues are not set up */
+ /* Drop the packet if queues are not set up.
+ * This handler should be called inside an RCU read section
+ * so we don't need to enter it here explicitly.
+ */
+ num_queues = READ_ONCE(vif->num_queues);
if (num_queues < 1)
goto drop;
@@ -222,18 +226,18 @@ static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
{
struct xenvif *vif = netdev_priv(dev);
struct xenvif_queue *queue = NULL;
+ unsigned int num_queues;
u64 rx_bytes = 0;
u64 rx_packets = 0;
u64 tx_bytes = 0;
u64 tx_packets = 0;
unsigned int index;
- spin_lock(&vif->lock);
- if (vif->queues == NULL)
- goto out;
+ rcu_read_lock();
+ num_queues = READ_ONCE(vif->num_queues);
/* Aggregate tx and rx stats from each queue */
- for (index = 0; index < vif->num_queues; ++index) {
+ for (index = 0; index < num_queues; ++index) {
queue = &vif->queues[index];
rx_bytes += queue->stats.rx_bytes;
rx_packets += queue->stats.rx_packets;
@@ -241,8 +245,7 @@ static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
tx_packets += queue->stats.tx_packets;
}
-out:
- spin_unlock(&vif->lock);
+ rcu_read_unlock();
vif->dev->stats.rx_bytes = rx_bytes;
vif->dev->stats.rx_packets = rx_packets;
@@ -378,10 +381,13 @@ static void xenvif_get_ethtool_stats(struct net_device *dev,
struct ethtool_stats *stats, u64 * data)
{
struct xenvif *vif = netdev_priv(dev);
- unsigned int num_queues = vif->num_queues;
+ unsigned int num_queues;
int i;
unsigned int queue_index;
+ rcu_read_lock();
+ num_queues = READ_ONCE(vif->num_queues);
+
for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
unsigned long accum = 0;
for (queue_index = 0; queue_index < num_queues; ++queue_index) {
@@ -390,6 +396,8 @@ static void xenvif_get_ethtool_stats(struct net_device *dev,
}
data[i] = accum;
}
+
+ rcu_read_unlock();
}
static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index f9bcf4a665bc..602d408fa25e 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -214,7 +214,7 @@ static void xenvif_fatal_tx_err(struct xenvif *vif)
netdev_err(vif->dev, "fatal error; disabling device\n");
vif->disabled = true;
/* Disable the vif from queue 0's kthread */
- if (vif->queues)
+ if (vif->num_queues)
xenvif_kick_thread(&vif->queues[0]);
}
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index d2d7cd9145b1..a56d3eab35dd 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -495,26 +495,26 @@ static void backend_disconnect(struct backend_info *be)
struct xenvif *vif = be->vif;
if (vif) {
+ unsigned int num_queues = vif->num_queues;
unsigned int queue_index;
- struct xenvif_queue *queues;
xen_unregister_watchers(vif);
#ifdef CONFIG_DEBUG_FS
xenvif_debugfs_delif(vif);
#endif /* CONFIG_DEBUG_FS */
xenvif_disconnect_data(vif);
- for (queue_index = 0;
- queue_index < vif->num_queues;
- ++queue_index)
- xenvif_deinit_queue(&vif->queues[queue_index]);
- spin_lock(&vif->lock);
- queues = vif->queues;
+ /* At this point some of the handlers may still be active
+ * so we need to have additional synchronization here.
+ */
vif->num_queues = 0;
- vif->queues = NULL;
- spin_unlock(&vif->lock);
+ synchronize_net();
- vfree(queues);
+ for (queue_index = 0; queue_index < num_queues; ++queue_index)
+ xenvif_deinit_queue(&vif->queues[queue_index]);
+
+ vfree(vif->queues);
+ vif->queues = NULL;
xenvif_disconnect_ctrl(vif);
}