xen/netfront: Use u64_stats_t with u64_stats_sync properly

On 64bit arches, struct u64_stats_sync is empty and provides no help
against load/store tearing. Convert to u64_stats_t to ensure atomic
operations.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Link: https://patch.msgid.link/20260121082550.2389249-1-mmyangfl@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 7c2220366623eb547f2e7625a2f4fc3b0d46c0f9..0969d5c9f6b76d60b0b352bbcd850eafe0f1e619 100644 (file)
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -97,8 +97,8 @@ struct netfront_cb {
 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
 
 struct netfront_stats {
-       u64                     packets;
-       u64                     bytes;
+       u64_stats_t             packets;
+       u64_stats_t             bytes;
        struct u64_stats_sync   syncp;
 };
 
@@ -634,8 +634,8 @@ static int xennet_xdp_xmit_one(struct net_device *dev,
                notify_remote_via_irq(queue->tx_irq);
 
        u64_stats_update_begin(&tx_stats->syncp);
-       tx_stats->bytes += xdpf->len;
-       tx_stats->packets++;
+       u64_stats_add(&tx_stats->bytes, xdpf->len);
+       u64_stats_inc(&tx_stats->packets);
        u64_stats_update_end(&tx_stats->syncp);
 
        return 0;
@@ -843,8 +843,8 @@ static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev
                notify_remote_via_irq(queue->tx_irq);
 
        u64_stats_update_begin(&tx_stats->syncp);
-       tx_stats->bytes += skb->len;
-       tx_stats->packets++;
+       u64_stats_add(&tx_stats->bytes, skb->len);
+       u64_stats_inc(&tx_stats->packets);
        u64_stats_update_end(&tx_stats->syncp);
 
        if (!netfront_tx_slot_available(queue))
@@ -1249,8 +1249,8 @@ static int handle_incoming_queue(struct netfront_queue *queue,
                }
 
                u64_stats_update_begin(&rx_stats->syncp);
-               rx_stats->packets++;
-               rx_stats->bytes += skb->len;
+               u64_stats_inc(&rx_stats->packets);
+               u64_stats_add(&rx_stats->bytes, skb->len);
                u64_stats_update_end(&rx_stats->syncp);
 
                /* Pass it up. */
@@ -1400,14 +1400,14 @@ static void xennet_get_stats64(struct net_device *dev,
 
                do {
                        start = u64_stats_fetch_begin(&tx_stats->syncp);
-                       tx_packets = tx_stats->packets;
-                       tx_bytes = tx_stats->bytes;
+                       tx_packets = u64_stats_read(&tx_stats->packets);
+                       tx_bytes = u64_stats_read(&tx_stats->bytes);
                } while (u64_stats_fetch_retry(&tx_stats->syncp, start));
 
                do {
                        start = u64_stats_fetch_begin(&rx_stats->syncp);
-                       rx_packets = rx_stats->packets;
-                       rx_bytes = rx_stats->bytes;
+                       rx_packets = u64_stats_read(&rx_stats->packets);
+                       rx_bytes = u64_stats_read(&rx_stats->bytes);
                } while (u64_stats_fetch_retry(&rx_stats->syncp, start));
 
                tot->rx_packets += rx_packets;