Merge branch 'skb_ext-fixes'

Paolo Abeni says:

====================
net: skb extension follow-ups

This series includes some follow-up for the recently added skb extension.
The first patch addresses an unlikely race while adding skb extensions,
and the following two are just minor code clean-up.

v1 -> v2:
- be sure to flag the newly added extension as active in skb_ext_add()
====================

Signed-off-by: David S. Miller <[e-mail]>

include/linux/skbuff.h

···
 		__skb_ext_put(skb->extensions);
 }
 
-static inline void skb_ext_get(struct sk_buff *skb)
-{
-	if (skb->active_extensions) {
-		struct skb_ext *ext = skb->extensions;
-
-		if (ext)
-			refcount_inc(&ext->refcnt);
-	}
-}
-
 static inline void __skb_ext_copy(struct sk_buff *dst,
 				  const struct sk_buff *src)
 {
···
 }
 #else
 static inline void skb_ext_put(struct sk_buff *skb) {}
-static inline void skb_ext_get(struct sk_buff *skb) {}
 static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}

net/core/skbuff.c

···
 		if (!new)
 			return NULL;
 
-		if (__skb_ext_exist(old, id)) {
-			if (old != new)
-				skb->extensions = new;
+		if (__skb_ext_exist(new, id))
 			goto set_active;
-		}
 
-		newoff = old->chunks;
+		newoff = new->chunks;
 	} else {
 		newoff = SKB_EXT_CHUNKSIZEOF(*new);
 
···
 	newlen = newoff + skb_ext_type_len[id];
 	new->chunks = newlen;
 	new->offset[id] = newoff;
-	skb->extensions = new;
 set_active:
+	skb->extensions = new;
 	skb->active_extensions |= 1 << id;
 	return skb_ext_get_ptr(new, id);
 }