net: Convert GRO SKB handling to list_head.
Manage pending per-NAPI GRO packets via list_head.
Return an SKB pointer from the GRO receive handlers. When GRO receive
handlers return non-NULL, it means that this SKB needs to be completed
at this time and removed from the NAPI queue.
Several operations are greatly simplified by this transformation,
especially timing out the oldest SKB in the list when gro_count
exceeds MAX_GRO_SKBS, and napi_gro_flush() which walks the queue
in reverse order.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 8cc7c348..f5aee64 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -180,9 +180,9 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
return segs;
}
-struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
+struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb)
{
- struct sk_buff **pp = NULL;
+ struct sk_buff *pp = NULL;
struct sk_buff *p;
struct tcphdr *th;
struct tcphdr *th2;
@@ -220,7 +220,7 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
len = skb_gro_len(skb);
flags = tcp_flag_word(th);
- for (; (p = *head); head = &p->next) {
+ list_for_each_entry(p, head, list) {
if (!NAPI_GRO_CB(p)->same_flow)
continue;
@@ -233,7 +233,7 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
goto found;
}
-
+ p = NULL;
goto out_check_final;
found:
@@ -263,7 +263,7 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
flush |= (len - 1) >= mss;
flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
- if (flush || skb_gro_receive(head, skb)) {
+ if (flush || skb_gro_receive(p, skb)) {
mss = 1;
goto out_check_final;
}
@@ -277,7 +277,7 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
TCP_FLAG_FIN));
if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
- pp = head;
+ pp = p;
out:
NAPI_GRO_CB(skb)->flush |= (flush != 0);
@@ -302,7 +302,7 @@ int tcp_gro_complete(struct sk_buff *skb)
}
EXPORT_SYMBOL(tcp_gro_complete);
-static struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
+static struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)
{
/* Don't bother verifying checksum if we're going to flush anyway. */
if (!NAPI_GRO_CB(skb)->flush &&