net: Add and use skb_mark_not_on_list().

An SKB is not on a list if skb->next is NULL.

Codify this convention into a helper function and use it
where we are dequeueing an SKB and need to mark it as such.

Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 10 insertions, 10 deletions

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index c07c30b916d5..dc539295ae65 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -812,7 +812,7 @@ static struct sk_buff *dequeue_head(struct cake_flow *flow)
 
 	if (skb) {
 		flow->head = skb->next;
-		skb->next = NULL;
+		skb_mark_not_on_list(skb);
 	}
 
 	return skb;
@@ -1252,7 +1252,7 @@ found:
 	else
 		flow->head = elig_ack->next;
 
-	elig_ack->next = NULL;
+	skb_mark_not_on_list(elig_ack);
 
 	return elig_ack;
 }
@@ -1675,7 +1675,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 
 		while (segs) {
 			nskb = segs->next;
-			segs->next = NULL;
+			skb_mark_not_on_list(segs);
 			qdisc_skb_cb(segs)->pkt_len = segs->len;
 			cobalt_set_enqueue_time(segs, now);
 			get_cobalt_cb(segs)->adjusted_len = cake_overhead(q,
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 4808713c73b9..b27ba36a269c 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -319,7 +319,7 @@ static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow)
 
 	if (skb) {
 		flow->head = skb->next;
-		skb->next = NULL;
+		skb_mark_not_on_list(skb);
 		flow->qlen--;
 		qdisc_qstats_backlog_dec(sch, skb);
 		sch->q.qlen--;
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 6c0a9d5dbf94..cd04d40c30b6 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -124,7 +124,7 @@ static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow)
 	struct sk_buff *skb = flow->head;
 
 	flow->head = skb->next;
-	skb->next = NULL;
+	skb_mark_not_on_list(skb);
 	return skb;
 }
 
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 69078c82963e..a64132a5db36 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -184,7 +184,7 @@ static void try_bulk_dequeue_skb(struct Qdisc *q,
 		skb = nskb;
 		(*packets)++; /* GSO counts as one pkt */
 	}
-	skb->next = NULL;
+	skb_mark_not_on_list(skb);
 }
 
 /* This variant of try_bulk_dequeue_skb() makes sure
@@ -210,7 +210,7 @@ static void try_bulk_dequeue_skb_slow(struct Qdisc *q,
 		skb = nskb;
 	} while (++cnt < 8);
 	(*packets) += cnt;
-	skb->next = NULL;
+	skb_mark_not_on_list(skb);
 }
 
 /* Note that dequeue_skb can possibly return a SKB list (via skb->next).
diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index c3a8388dcdf6..9d6a47697406 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -330,7 +330,7 @@ static struct sk_buff *dequeue_head(struct wdrr_bucket *bucket)
 	struct sk_buff *skb = bucket->head;
 
 	bucket->head = skb->next;
-	skb->next = NULL;
+	skb_mark_not_on_list(skb);
 	return skb;
 }
 
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index b9541ce4d672..506e1960ed7f 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -568,7 +568,7 @@ finish_segs:
 	if (segs) {
 		while (segs) {
 			skb2 = segs->next;
-			segs->next = NULL;
+			skb_mark_not_on_list(segs);
 			qdisc_skb_cb(segs)->pkt_len = segs->len;
 			last_len = segs->len;
 			rc = qdisc_enqueue(segs, sch, to_free);
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index 6f74a426f159..a4530e85bd02 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -162,7 +162,7 @@ static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch,
 	nb = 0;
 	while (segs) {
 		nskb = segs->next;
-		segs->next = NULL;
+		skb_mark_not_on_list(segs);
 		qdisc_skb_cb(segs)->pkt_len = segs->len;
 		len += segs->len;
 		ret = qdisc_enqueue(segs, q->qdisc, to_free);