From: Vlad Yasevich <vyasevic@redhat.com>
Date: Tue, 26 Nov 2013 17:37:12 +0000 (-0500)
Subject: macvtap: Do not double-count received packets
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=006da7b07bc4d3a7ffabad17cf639eec6849c9dc;p=deliverable%2Flinux.git

macvtap: Do not double-count received packets

Currently macvlan will count received packets after calling each
vlans receive handler.   Macvtap attempts to count the packet
yet again when the user reads the packet from the tap socket.
This code doesn't do this consistently either.  Remove the
counting from macvtap and let only macvlan count received
packets.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 0605da8e25f5..9093004f9b63 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -767,7 +767,6 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
 				const struct sk_buff *skb,
 				const struct iovec *iv, int len)
 {
-	struct macvlan_dev *vlan;
 	int ret;
 	int vnet_hdr_len = 0;
 	int vlan_offset = 0;
@@ -821,15 +820,6 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
 	copied += len;
 
 done:
-	rcu_read_lock();
-	vlan = rcu_dereference(q->vlan);
-	if (vlan) {
-		preempt_disable();
-		macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0);
-		preempt_enable();
-	}
-	rcu_read_unlock();
-
 	return ret ? ret : copied;
 }