net: sched: cleanup qdisc_run and __qdisc_run semantics

Currently __qdisc_run calls qdisc_run_end() but does not call
qdisc_run_begin(). This makes it hard to track pairs of
qdisc_run_{begin,end} across function calls.

To simplify reading these code paths this patch moves begin/end calls
into qdisc_run().
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/pkt_sched.h

@@ -113,8 +113,10 @@ void __qdisc_run(struct Qdisc *q);
 
 static inline void qdisc_run(struct Qdisc *q)
 {
-	if (qdisc_run_begin(q))
+	if (qdisc_run_begin(q)) {
 		__qdisc_run(q);
+		qdisc_run_end(q);
+	}
 }
 
 static inline __be16 tc_skb_protocol(const struct sk_buff *skb)

net/core/dev.c

@@ -3192,9 +3192,9 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 				contended = false;
 			}
 			__qdisc_run(q);
-		} else
-			qdisc_run_end(q);
+		}
 
+		qdisc_run_end(q);
 		rc = NET_XMIT_SUCCESS;
 	} else {
 		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
@@ -3204,6 +3204,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 				contended = false;
 			}
 			__qdisc_run(q);
+			qdisc_run_end(q);
 		}
 	}
 	spin_unlock(root_lock);

net/sched/sch_generic.c

@@ -266,8 +266,6 @@ void __qdisc_run(struct Qdisc *q)
 			break;
 		}
 	}
-
-	qdisc_run_end(q);
 }
 
 unsigned long dev_trans_start(struct net_device *dev)