tun: fix bonding active backup with arp monitoring

stable inclusion
form stable-v5.10.82
commit 528971af64fc88767e91ae12c0ae036af928feaa
bugzilla: 185877 https://gitee.com/openeuler/kernel/issues/I4QU6V

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=528971af64fc88767e91ae12c0ae036af928feaa

--------------------------------

commit a31d27fb upstream.

As stated in the bonding doc, trans_start must be set manually for drivers
using NETIF_F_LLTX:
 Drivers that use NETIF_F_LLTX flag must also update
 netdev_queue->trans_start. If they do not, then the ARP monitor will
 immediately fail any slaves using that driver, and those slaves will stay
 down.

Link: https://www.kernel.org/doc/html/v5.15/networking/bonding.html#arp-monitor-operationSigned-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/tun.c

@@ -1021,6 +1021,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct tun_struct *tun = netdev_priv(dev);
 	int txq = skb->queue_mapping;
+	struct netdev_queue *queue;
 	struct tun_file *tfile;
 	int len = skb->len;
 
@@ -1065,6 +1066,10 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (ptr_ring_produce(&tfile->tx_ring, skb))
 		goto drop;
 
+	/* NETIF_F_LLTX requires to do our own update of trans_start */
+	queue = netdev_get_tx_queue(dev, txq);
+	queue->trans_start = jiffies;
+
 	/* Notify and wake up reader process */
 	if (tfile->flags & TUN_FASYNC)
 		kill_fasync(&tfile->fasync, SIGIO, POLL_IN);