datapath: Check for skb_cow_head(), not skb_cow().

skb_cow() has been present since 2.6.12 or earlier, but skb_cow_head() was
added only in 2.6.23, so we were checking for the wrong identifier here.

diff --git a/acinclude.m4 b/acinclude.m4
index cabe7d3..015bf66 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -157,8 +157,8 @@ AC_DEFUN([OVS_CHECK_LINUX26_COMPAT], [
   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], 
                   [skb_copy_from_linear_data_offset],
                   [OVS_DEFINE([HAVE_SKB_COPY_FROM_LINEAR_DATA_OFFSET])])
-  OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_cow],
-                  [OVS_DEFINE([HAVE_SKB_COW])])
+  OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_cow_head],
+                  [OVS_DEFINE([HAVE_SKB_COW_HEAD])])
   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_transport_header],
                   [OVS_DEFINE([HAVE_SKBUFF_HEADER_HELPERS])])
   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_warn_if_lro],

diff --git a/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h b/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h
index 5ed0e48..15acea9 100644 (file)
--- a/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h
+++ b/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h
@@ -53,7 +53,7 @@ static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
 #define NET_SKB_PAD    16
 #endif
 
-#ifndef HAVE_SKB_COW
+#ifndef HAVE_SKB_COW_HEAD
 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
                             int cloned)
 {
@@ -74,7 +74,7 @@ static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
 {
        return __skb_cow(skb, headroom, skb_header_cloned(skb));
 }
-#endif  /* !HAVE_SKB_COW */
+#endif /* !HAVE_SKB_COW_HEAD */
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
 static inline int skb_clone_writable(struct sk_buff *skb, int len)