[NET]: Kill skb->list

Remove the "list" member of struct sk_buff, as it is entirely
redundant.  All SKB list removal callers know which list the
SKB is on, so storing this in sk_buff does nothing other than
taking up some space.

Two tricky bits were SCTP, which I took care of, and two ATM
drivers which Francois Romieu <romieu@fr.zoreil.com> fixed
up.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>

3 files changed, 20 insertions, 17 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 69b1fcf70077..d2696af46c70 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -975,7 +975,7 @@ do_fault:
         if (!skb->len) {
                 if (sk->sk_send_head == skb)
                         sk->sk_send_head = NULL;
-                __skb_unlink(skb, skb->list);
+                __skb_unlink(skb, &sk->sk_write_queue);
                 sk_stream_free_skb(sk, skb);
         }
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 53a8a5399f1e..ffa24025cd02 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2085,7 +2085,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p, s32 *seq_usrtt
                         seq_rtt = now - scb->when;
                 tcp_dec_pcount_approx(&tp->fackets_out, skb);
                 tcp_packets_out_dec(tp, skb);
-                __skb_unlink(skb, skb->list);
+                __skb_unlink(skb, &sk->sk_write_queue);
                 sk_stream_free_skb(sk, skb);
         }
 
@@ -2853,7 +2853,7 @@ static void tcp_ofo_queue(struct sock *sk)
 
                 if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
                         SOCK_DEBUG(sk, "ofo packet was already received \n");
-                        __skb_unlink(skb, skb->list);
+                        __skb_unlink(skb, &tp->out_of_order_queue);
                         __kfree_skb(skb);
                         continue;
                 }
@@ -2861,7 +2861,7 @@ static void tcp_ofo_queue(struct sock *sk)
                            tp->rcv_nxt, TCP_SKB_CB(skb)->seq,
                            TCP_SKB_CB(skb)->end_seq);
 
-                __skb_unlink(skb, skb->list);
+                __skb_unlink(skb, &tp->out_of_order_queue);
                 __skb_queue_tail(&sk->sk_receive_queue, skb);
                 tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
                 if(skb->h.th->fin)
@@ -3027,7 +3027,7 @@ drop:
                 u32 end_seq = TCP_SKB_CB(skb)->end_seq;
 
                 if (seq == TCP_SKB_CB(skb1)->end_seq) {
-                        __skb_append(skb1, skb);
+                        __skb_append(skb1, skb, &tp->out_of_order_queue);
 
                         if (!tp->rx_opt.num_sacks ||
                             tp->selective_acks[0].end_seq != seq)
@@ -3071,7 +3071,7 @@ drop:
                                tcp_dsack_extend(tp, TCP_SKB_CB(skb1)->seq, end_seq);
                                break;
                        }
-                       __skb_unlink(skb1, skb1->list);
+                       __skb_unlink(skb1, &tp->out_of_order_queue);
                        tcp_dsack_extend(tp, TCP_SKB_CB(skb1)->seq, TCP_SKB_CB(skb1)->end_seq);
                        __kfree_skb(skb1);
                 }
@@ -3088,8 +3088,9 @@ add_sack:
  * simplifies code)
  */
 static void
-tcp_collapse(struct sock *sk, struct sk_buff *head,
-             struct sk_buff *tail, u32 start, u32 end)
+tcp_collapse(struct sock *sk, struct sk_buff_head *list,
+             struct sk_buff *head, struct sk_buff *tail,
+             u32 start, u32 end)
 {
         struct sk_buff *skb;
 
@@ -3099,7 +3100,7 @@ tcp_collapse(struct sock *sk, struct sk_buff *head,
                 /* No new bits? It is possible on ofo queue. */
                 if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
                         struct sk_buff *next = skb->next;
-                        __skb_unlink(skb, skb->list);
+                        __skb_unlink(skb, list);
                         __kfree_skb(skb);
                         NET_INC_STATS_BH(LINUX_MIB_TCPRCVCOLLAPSED);
                         skb = next;
@@ -3145,7 +3146,7 @@ tcp_collapse(struct sock *sk, struct sk_buff *head,
                 nskb->mac.raw = nskb->head + (skb->mac.raw-skb->head);
                 memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
                 TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
-                __skb_insert(nskb, skb->prev, skb, skb->list);
+                __skb_insert(nskb, skb->prev, skb, list);
                 sk_stream_set_owner_r(nskb, sk);
 
                 /* Copy data, releasing collapsed skbs. */
@@ -3164,7 +3165,7 @@ tcp_collapse(struct sock *sk, struct sk_buff *head,
                         }
                         if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
                                 struct sk_buff *next = skb->next;
-                                __skb_unlink(skb, skb->list);
+                                __skb_unlink(skb, list);
                                 __kfree_skb(skb);
                                 NET_INC_STATS_BH(LINUX_MIB_TCPRCVCOLLAPSED);
                                 skb = next;
@@ -3200,7 +3201,8 @@ static void tcp_collapse_ofo_queue(struct sock *sk)
                 if (skb == (struct sk_buff *)&tp->out_of_order_queue ||
                     after(TCP_SKB_CB(skb)->seq, end) ||
                     before(TCP_SKB_CB(skb)->end_seq, start)) {
-                        tcp_collapse(sk, head, skb, start, end);
+                        tcp_collapse(sk, &tp->out_of_order_queue,
+                                     head, skb, start, end);
                         head = skb;
                         if (skb == (struct sk_buff *)&tp->out_of_order_queue)
                                 break;
@@ -3237,7 +3239,8 @@ static int tcp_prune_queue(struct sock *sk)
                 tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
 
         tcp_collapse_ofo_queue(sk);
-        tcp_collapse(sk, sk->sk_receive_queue.next,
+        tcp_collapse(sk, &sk->sk_receive_queue,
+                     sk->sk_receive_queue.next,
                      (struct sk_buff*)&sk->sk_receive_queue,
                      tp->copied_seq, tp->rcv_nxt);
         sk_stream_mem_reclaim(sk);
@@ -3462,7 +3465,7 @@ static void tcp_check_urg(struct sock * sk, struct tcphdr * th)
                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
                 tp->copied_seq++;
                 if (skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)) {
-                        __skb_unlink(skb, skb->list);
+                        __skb_unlink(skb, &sk->sk_receive_queue);
                         __kfree_skb(skb);
                 }
         }
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index dd30dd137b74..a4d1eb9a0926 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -505,7 +505,7 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned
 
         /* Link BUFF into the send queue. */
         skb_header_release(buff);
-        __skb_append(skb, buff);
+        __skb_append(skb, buff, &sk->sk_write_queue);
 
         return 0;
 }
@@ -893,7 +893,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 
         /* Link BUFF into the send queue. */
         skb_header_release(buff);
-        __skb_append(skb, buff);
+        __skb_append(skb, buff, &sk->sk_write_queue);
 
         return 0;
 }
@@ -1238,7 +1238,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
                        tcp_skb_pcount(next_skb) != 1);
 
                 /* Ok.  We will be able to collapse the packet. */
-                __skb_unlink(next_skb, next_skb->list);
+                __skb_unlink(next_skb, &sk->sk_write_queue);
 
                 memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);