ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice

6c79bf0f2440fd250c8fce8d9b82fcf03d4e8350 subtracts PPPOE_SES_HLEN from mtu at
the front of ip_fragment(). So the later subtraction should be removed. The
MTU of 802.1q is also 1500, so MTU should not be changed.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Bart De Schuymer <bdschuym@pandora.bo>
----
 net/ipv4/ip_output.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
Signed-off-by: Bart De Schuymer <bdschuym@pandora.bo>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 4 deletions

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 6652bd9da67..04b69896df5 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -446,7 +446,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
         int ptr;
         struct net_device *dev;
         struct sk_buff *skb2;
-        unsigned int mtu, hlen, left, len, ll_rs, pad;
+        unsigned int mtu, hlen, left, len, ll_rs;
         int offset;
         __be16 not_last_frag;
         struct rtable *rt = skb_rtable(skb);
@@ -585,9 +585,7 @@ slow_path:
         /* for bridged IP traffic encapsulated inside f.e. a vlan header,
          * we need to make room for the encapsulating header
          */
-        pad = nf_bridge_pad(skb);
-        ll_rs = LL_RESERVED_SPACE_EXTRA(rt->dst.dev, pad);
-        mtu -= pad;
+        ll_rs = LL_RESERVED_SPACE_EXTRA(rt->dst.dev, nf_bridge_pad(skb));
 
         /*
          *      Fragment the datagram.