net: Add skb_queue_walk_from() and skb_queue_walk_from_safe().

These will be used by TCP write queue handling and elsewhere.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index d2f1778..a19ea43 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1571,6 +1571,15 @@ static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
                     skb != (struct sk_buff *)(queue);                          \
                     skb = tmp, tmp = skb->next)
 
+#define skb_queue_walk_from(queue, skb)                                                \
+               for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
+                    skb = skb->next)
+
+#define skb_queue_walk_from_safe(queue, skb, tmp)                              \
+               for (tmp = skb->next;                                           \
+                    skb != (struct sk_buff *)(queue);                          \
+                    skb = tmp, tmp = skb->next)
+
 #define skb_queue_reverse_walk(queue, skb) \
                for (skb = (queue)->prev;                                       \
                     prefetch(skb->prev), (skb != (struct sk_buff *)(queue));   \