Merge branch 'refactor-duplicate-codes-in-the-qdisc-class-walk-function'

Zhengchao Shao says:

====================
refactor duplicate codes in the qdisc class walk function

The walk implementation of most qdisc class modules is basically the
same. That is, the values of count and skip are checked first. If count
is greater than or equal to skip, the registered fn function is
executed. Otherwise, increase the value of count. So the code can be
refactored.

The walk function is invoked during dump. Therefore, test cases related
 to the tdc filter need to be added.
====================

Link: https://lore.kernel.org/r/20220921024040.385296-1-shaozhengchao@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/pkt_sched.h

@@ -222,4 +222,17 @@ static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)
 	return cb;
 }
 
+static inline bool tc_qdisc_stats_dump(struct Qdisc *sch,
+				       unsigned long cl,
+				       struct qdisc_walker *arg)
+{
+	if (arg->count >= arg->skip && arg->fn(sch, cl, arg) < 0) {
+		arg->stop = 1;
+		return false;
+	}
+
+	arg->count++;
+	return true;
+}
+
 #endif

net/sched/sch_atm.c

@@ -354,12 +354,8 @@ static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 	if (walker->stop)
 		return;
 	list_for_each_entry(flow, &p->flows, list) {
-		if (walker->count >= walker->skip &&
-		    walker->fn(sch, (unsigned long)flow, walker) < 0) {
-			walker->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, (unsigned long)flow, walker))
 			break;
-		}
-		walker->count++;
 	}
 }
 

net/sched/sch_cake.c

@@ -3061,16 +3061,13 @@ static void cake_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		struct cake_tin_data *b = &q->tins[q->tin_order[i]];
 
 		for (j = 0; j < CAKE_QUEUES; j++) {
-			if (list_empty(&b->flows[j].flowchain) ||
-			    arg->count < arg->skip) {
+			if (list_empty(&b->flows[j].flowchain)) {
 				arg->count++;
 				continue;
 			}
-			if (arg->fn(sch, i * CAKE_QUEUES + j + 1, arg) < 0) {
-				arg->stop = 1;
+			if (!tc_qdisc_stats_dump(sch, i * CAKE_QUEUES + j + 1,
+						 arg))
 				break;
-			}
-			arg->count++;
 		}
 	}
 }

net/sched/sch_cbq.c

@@ -1676,15 +1676,8 @@ static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 	for (h = 0; h < q->clhash.hashsize; h++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
-			if (arg->count < arg->skip) {
-				arg->count++;
-				continue;
-			}
-			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
-				arg->stop = 1;
+			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
 				return;
-			}
-			arg->count++;
 		}
 	}
 }

net/sched/sch_cbs.c

@@ -520,13 +520,7 @@ static unsigned long cbs_find(struct Qdisc *sch, u32 classid)
 static void cbs_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
-		if (walker->count >= walker->skip) {
-			if (walker->fn(sch, 1, walker) < 0) {
-				walker->stop = 1;
-				return;
-			}
-		}
-		walker->count++;
+		tc_qdisc_stats_dump(sch, 1, walker);
 	}
 }
 

net/sched/sch_drr.c

@@ -284,15 +284,8 @@ static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
-			if (arg->count < arg->skip) {
-				arg->count++;
-				continue;
-			}
-			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
-				arg->stop = 1;
+			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
 				return;
-			}
-			arg->count++;
 		}
 	}
 }

net/sched/sch_dsmark.c

@@ -176,16 +176,12 @@ static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 		return;
 
 	for (i = 0; i < p->indices; i++) {
-		if (p->mv[i].mask == 0xff && !p->mv[i].value)
-			goto ignore;
-		if (walker->count >= walker->skip) {
-			if (walker->fn(sch, i + 1, walker) < 0) {
-				walker->stop = 1;
-				break;
-			}
+		if (p->mv[i].mask == 0xff && !p->mv[i].value) {
+			walker->count++;
+			continue;
 		}
-ignore:
-		walker->count++;
+		if (!tc_qdisc_stats_dump(sch, i + 1, walker))
+			break;
 	}
 }
 

net/sched/sch_ets.c

@@ -341,15 +341,8 @@ static void ets_qdisc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		return;
 
 	for (i = 0; i < q->nbands; i++) {
-		if (arg->count < arg->skip) {
-			arg->count++;
-			continue;
-		}
-		if (arg->fn(sch, i + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, i + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_fq_codel.c

@@ -673,16 +673,12 @@ static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		return;
 
 	for (i = 0; i < q->flows_cnt; i++) {
-		if (list_empty(&q->flows[i].flowchain) ||
-		    arg->count < arg->skip) {
+		if (list_empty(&q->flows[i].flowchain)) {
 			arg->count++;
 			continue;
 		}
-		if (arg->fn(sch, i + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, i + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_hfsc.c

@@ -1349,15 +1349,8 @@ hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[i],
 				     cl_common.hnode) {
-			if (arg->count < arg->skip) {
-				arg->count++;
-				continue;
-			}
-			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
-				arg->stop = 1;
+			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
 				return;
-			}
-			arg->count++;
 		}
 	}
 }

net/sched/sch_htb.c

@@ -2119,15 +2119,8 @@ static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
-			if (arg->count < arg->skip) {
-				arg->count++;
-				continue;
-			}
-			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
-				arg->stop = 1;
+			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
 				return;
-			}
-			arg->count++;
 		}
 	}
 }

net/sched/sch_mq.c

@@ -247,11 +247,8 @@ static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 	arg->count = arg->skip;
 	for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
-		if (arg->fn(sch, ntx + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, ntx + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_mqprio.c

@@ -558,11 +558,8 @@ static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 	/* Walk hierarchy with a virtual class per tc */
 	arg->count = arg->skip;
 	for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
-		if (arg->fn(sch, ntx + TC_H_MIN_PRIORITY, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, ntx + TC_H_MIN_PRIORITY, arg))
 			return;
-		}
-		arg->count++;
 	}
 
 	/* Pad the values and skip over unused traffic classes */

net/sched/sch_multiq.c

@@ -353,15 +353,8 @@ static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		return;
 
 	for (band = 0; band < q->bands; band++) {
-		if (arg->count < arg->skip) {
-			arg->count++;
-			continue;
-		}
-		if (arg->fn(sch, band + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, band + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_netem.c

@@ -1251,12 +1251,8 @@ static unsigned long netem_find(struct Qdisc *sch, u32 classid)
 static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
-		if (walker->count >= walker->skip)
-			if (walker->fn(sch, 1, walker) < 0) {
-				walker->stop = 1;
-				return;
-			}
-		walker->count++;
+		if (!tc_qdisc_stats_dump(sch, 1, walker))
+			return;
 	}
 }
 

net/sched/sch_prio.c

@@ -376,15 +376,8 @@ static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		return;
 
 	for (prio = 0; prio < q->bands; prio++) {
-		if (arg->count < arg->skip) {
-			arg->count++;
-			continue;
-		}
-		if (arg->fn(sch, prio + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, prio + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_qfq.c

@@ -659,15 +659,8 @@ static void qfq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
-			if (arg->count < arg->skip) {
-				arg->count++;
-				continue;
-			}
-			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
-				arg->stop = 1;
+			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
 				return;
-			}
-			arg->count++;
 		}
 	}
 }

net/sched/sch_red.c

@@ -516,12 +516,7 @@ static unsigned long red_find(struct Qdisc *sch, u32 classid)
 static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
-		if (walker->count >= walker->skip)
-			if (walker->fn(sch, 1, walker) < 0) {
-				walker->stop = 1;
-				return;
-			}
-		walker->count++;
+		tc_qdisc_stats_dump(sch, 1, walker);
 	}
 }
 

net/sched/sch_sfb.c

@@ -659,12 +659,7 @@ static int sfb_delete(struct Qdisc *sch, unsigned long cl,
 static void sfb_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
-		if (walker->count >= walker->skip)
-			if (walker->fn(sch, 1, walker) < 0) {
-				walker->stop = 1;
-				return;
-			}
-		walker->count++;
+		tc_qdisc_stats_dump(sch, 1, walker);
 	}
 }
 

net/sched/sch_sfq.c

@@ -888,16 +888,12 @@ static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		return;
 
 	for (i = 0; i < q->divisor; i++) {
-		if (q->ht[i] == SFQ_EMPTY_SLOT ||
-		    arg->count < arg->skip) {
+		if (q->ht[i] == SFQ_EMPTY_SLOT) {
 			arg->count++;
 			continue;
 		}
-		if (arg->fn(sch, i + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, i + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_skbprio.c

@@ -265,15 +265,8 @@ static void skbprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		return;
 
 	for (i = 0; i < SKBPRIO_MAX_PRIORITY; i++) {
-		if (arg->count < arg->skip) {
-			arg->count++;
-			continue;
-		}
-		if (arg->fn(sch, i + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, i + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_taprio.c

@@ -1953,11 +1953,8 @@ static void taprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 	arg->count = arg->skip;
 	for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
-		if (arg->fn(sch, ntx + 1, arg) < 0) {
-			arg->stop = 1;
+		if (!tc_qdisc_stats_dump(sch, ntx + 1, arg))
 			break;
-		}
-		arg->count++;
 	}
 }
 

net/sched/sch_tbf.c

@@ -580,12 +580,7 @@ static unsigned long tbf_find(struct Qdisc *sch, u32 classid)
 static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
-		if (walker->count >= walker->skip)
-			if (walker->fn(sch, 1, walker) < 0) {
-				walker->stop = 1;
-				return;
-			}
-		walker->count++;
+		tc_qdisc_stats_dump(sch, 1, walker);
 	}
 }