ipv4: Use frag list abstraction interfaces.

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

net/ipv4/ip_fragment.c

@@ -507,7 +507,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 	/* If the first fragment is fragmented itself, we split
 	 * it to two chunks: the first with data and paged part
 	 * and the second, holding only fragments. */
-	if (skb_shinfo(head)->frag_list) {
+	if (skb_has_frags(head)) {
 		struct sk_buff *clone;
 		int i, plen = 0;
 
@@ -516,7 +516,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 		clone->next = head->next;
 		head->next = clone;
 		skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
-		skb_shinfo(head)->frag_list = NULL;
+		skb_frag_list_init(head);
 		for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 			plen += skb_shinfo(head)->frags[i].size;
 		clone->len = clone->data_len = head->data_len - plen;

net/ipv4/ip_output.c

@@ -474,7 +474,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 	 * LATER: this step can be merged to real generation of fragments,
 	 * we can switch to copy when see the first bad fragment.
 	 */
-	if (skb_shinfo(skb)->frag_list) {
+	if (skb_has_frags(skb)) {
 		struct sk_buff *frag;
 		int first_len = skb_pagelen(skb);
 		int truesizes = 0;
@@ -485,7 +485,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 		    skb_cloned(skb))
 			goto slow_path;
 
-		for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
+		skb_walk_frags(skb, frag) {
 			/* Correct geometry. */
 			if (frag->len > mtu ||
 			    ((frag->len & 7) && frag->next) ||
@@ -510,7 +510,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 		err = 0;
 		offset = 0;
 		frag = skb_shinfo(skb)->frag_list;
-		skb_shinfo(skb)->frag_list = NULL;
+		skb_frag_list_init(skb);
 		skb->data_len = first_len - skb_headlen(skb);
 		skb->truesize -= truesizes;
 		skb->len = first_len;