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, 2 insertions, 1 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c86885954994..7ccc601b55d9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -677,7 +677,8 @@ struct sk_buff {
 				int			ip_defrag_offset;
 			};
 		};
-		struct rb_node	rbnode; /* used in netem & tcp stack */
+		struct rb_node		rbnode; /* used in netem & tcp stack */
+		struct list_head	list;
 	};
 	struct sock		*sk;