From: Jesse Gross <jesse@nicira.com>
Date: Sat, 8 May 2010 01:50:23 +0000 (-0700)
Subject: gre: Include route headers in headroom calculation.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=54adbf40ff717f05e081967102083889143447a7;p=openvswitch

gre: Include route headers in headroom calculation.

When calculating the amount of headroom required include the route,
which avoids a copy later when doing transforms like IPsec.
---

diff --git a/datapath/vport-gre.c b/datapath/vport-gre.c
index b7afd8f7..654ead06 100644
--- a/datapath/vport-gre.c
+++ b/datapath/vport-gre.c
@@ -1087,7 +1087,9 @@ gre_send(struct vport *vport, struct sk_buff *skb)
 	 * the segments.  This is particularly beneficial on Xen where we get
 	 * lots of GSO pskbs.  Conversely, we delay copying if it is just to
 	 * get our own writable clone because GSO may do the copy for us. */
-	max_headroom = LL_RESERVED_SPACE(rt->u.dst.dev) + mutable->tunnel_hlen;
+	max_headroom = LL_RESERVED_SPACE(rt->u.dst.dev) + rt->u.dst.header_len
+			+ mutable->tunnel_hlen;
+
 	if (skb_headroom(skb) < max_headroom) {
 		skb = check_headroom(skb, max_headroom);
 		if (unlikely(IS_ERR(skb))) {