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>

1 files changed, 7 insertions, 6 deletions

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 73a65789271b..99141986efa0 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -647,13 +647,14 @@ out:
         return err;
 }
 
-static struct sk_buff **vlan_gro_receive(struct sk_buff **head,
-                                         struct sk_buff *skb)
+static struct sk_buff *vlan_gro_receive(struct list_head *head,
+                                        struct sk_buff *skb)
 {
-        struct sk_buff *p, **pp = NULL;
-        struct vlan_hdr *vhdr;
-        unsigned int hlen, off_vlan;
         const struct packet_offload *ptype;
+        unsigned int hlen, off_vlan;
+        struct sk_buff *pp = NULL;
+        struct vlan_hdr *vhdr;
+        struct sk_buff *p;
         __be16 type;
         int flush = 1;
 
@@ -675,7 +676,7 @@ static struct sk_buff **vlan_gro_receive(struct sk_buff **head,
 
         flush = 0;
 
-        for (p = *head; p; p = p->next) {
+        list_for_each_entry(p, head, list) {
                 struct vlan_hdr *vhdr2;
 
                 if (!NAPI_GRO_CB(p)->same_flow)