net: sched: consolidate handle_ing and ing_filter

Given quite some code has been removed from ing_filter(), we can just
consolidate that function into handle_ing() and get rid of a few
instructions at the same time.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 30 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 862875ec8f2f..8a757464bfa2 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3521,37 +3521,19 @@ EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
 #endif
 
 #ifdef CONFIG_NET_CLS_ACT
-/* TODO: Maybe we should just force sch_ingress to be compiled in
- * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
- * a compare and 2 stores extra right now if we dont have it on
- * but have CONFIG_NET_CLS_ACT
- * NOTE: This doesn't stop any functionality; if you dont have
- * the ingress scheduler, you just can't add policies on ingress.
- *
- */
-static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
-{
-        int result = TC_ACT_OK;
-        struct Qdisc *q;
-
-        skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
-
-        q = rcu_dereference(rxq->qdisc);
-        if (q != &noop_qdisc) {
-                if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
-                        result = qdisc_enqueue_root(skb, q);
-        }
-
-        return result;
-}
-
 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
                                          struct packet_type **pt_prev,
                                          int *ret, struct net_device *orig_dev)
 {
         struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
+        struct Qdisc *q;
 
-        if (!rxq || rcu_access_pointer(rxq->qdisc) == &noop_qdisc)
+        /* If there's at least one ingress present somewhere (so
+         * we get here via enabled static key), remaining devices
+         * that are not configured with an ingress qdisc will bail
+         * out w/o the rcu_dereference().
+         */
+        if (!rxq || (q = rcu_dereference(rxq->qdisc)) == &noop_qdisc)
                 return skb;
 
         if (*pt_prev) {
@@ -3559,11 +3541,15 @@ static inline struct sk_buff *handle_ing(struct sk_buff *skb,
                 *pt_prev = NULL;
         }
 
-        switch (ing_filter(skb, rxq)) {
-        case TC_ACT_SHOT:
-        case TC_ACT_STOLEN:
-                kfree_skb(skb);
-                return NULL;
+        skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
+
+        if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
+                switch (qdisc_enqueue_root(skb, q)) {
+                case TC_ACT_SHOT:
+                case TC_ACT_STOLEN:
+                        kfree_skb(skb);
+                        return NULL;
+                }
         }
 
         return skb;