From 95e48d862ada73188be6d91a33c49d1712815bd2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 29 Mar 2024 15:42:20 +0000 Subject: [PATCH] net: enqueue_to_backlog() change vs not running device If the device attached to the packet given to enqueue_to_backlog() is not running, we drop the packet. But we accidentally increase sd->dropped, giving false signals to admins: sd->dropped should be reserved to cpu backlog pressure, not to temporary glitches at device dismantles. While we are at it, perform the netif_running() test before we get the rps lock, and use REASON_DEV_READY drop reason instead of NOT_SPECIFIED. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index c136e80dea618..4ad7836365e68 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4801,12 +4801,13 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu, unsigned long flags; unsigned int qlen; - reason = SKB_DROP_REASON_NOT_SPECIFIED; + reason = SKB_DROP_REASON_DEV_READY; + if (!netif_running(skb->dev)) + goto bad_dev; + sd = &per_cpu(softnet_data, cpu); backlog_lock_irq_save(sd, &flags); - if (!netif_running(skb->dev)) - goto drop; qlen = skb_queue_len(&sd->input_pkt_queue); if (qlen <= READ_ONCE(net_hotdata.max_backlog) && !skb_flow_limit(skb, qlen)) { @@ -4827,10 +4828,10 @@ enqueue: } reason = SKB_DROP_REASON_CPU_BACKLOG; -drop: sd->dropped++; backlog_unlock_irq_restore(sd, &flags); +bad_dev: dev_core_stats_rx_dropped_inc(skb->dev); kfree_skb_reason(skb, reason); return NET_RX_DROP; -- 2.30.2