net: add rb_to_skb helper for future commits

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

2 files changed, 249 insertions, 0 deletions

diff --git a/queue/net-add-rb_to_skb-and-other-rb-tree-helpers.patch b/queue/net-add-rb_to_skb-and-other-rb-tree-helpers.patch
new file mode 100644
index 0000000..7d9b75a
--- /dev/null
+++ b/queue/net-add-rb_to_skb-and-other-rb-tree-helpers.patch
@@ -0,0 +1,248 @@
+From 18a4c0eab2623cc95be98a1e6af1ad18e7695977 Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Thu, 5 Oct 2017 22:21:21 -0700
+Subject: [PATCH] net: add rb_to_skb() and other rb tree helpers
+
+commit 18a4c0eab2623cc95be98a1e6af1ad18e7695977 upstream.
+
+Geeralize private netem_rb_to_skb()
+
+TCP rtx queue will soon be converted to rb-tree,
+so we will need skb_rbtree_walk() helpers.
+
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+
+diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
+index 01a985937867..03634ec2f918 100644
+--- a/include/linux/skbuff.h
++++ b/include/linux/skbuff.h
+@@ -3158,6 +3158,12 @@ static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
+ 	return __skb_grow(skb, len);
+ }
+ 
++#define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
++#define skb_rb_first(root) rb_to_skb(rb_first(root))
++#define skb_rb_last(root)  rb_to_skb(rb_last(root))
++#define skb_rb_next(skb)   rb_to_skb(rb_next(&(skb)->rbnode))
++#define skb_rb_prev(skb)   rb_to_skb(rb_prev(&(skb)->rbnode))
++
+ #define skb_queue_walk(queue, skb) \
+ 		for (skb = (queue)->next;					\
+ 		     skb != (struct sk_buff *)(queue);				\
+@@ -3172,6 +3178,18 @@ static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
+ 		for (; skb != (struct sk_buff *)(queue);			\
+ 		     skb = skb->next)
+ 
++#define skb_rbtree_walk(skb, root)						\
++		for (skb = skb_rb_first(root); skb != NULL;			\
++		     skb = skb_rb_next(skb))
++
++#define skb_rbtree_walk_from(skb)						\
++		for (; skb != NULL;						\
++		     skb = skb_rb_next(skb))
++
++#define skb_rbtree_walk_from_safe(skb, tmp)					\
++		for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL);	\
++		     skb = tmp)
++
+ #define skb_queue_walk_from_safe(queue, skb, tmp)				\
+ 		for (tmp = skb->next;						\
+ 		     skb != (struct sk_buff *)(queue);				\
+diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
+index 29fff14d5a53..7ee4aadcdd71 100644
+--- a/net/ipv4/tcp_fastopen.c
++++ b/net/ipv4/tcp_fastopen.c
+@@ -465,17 +465,15 @@ bool tcp_fastopen_active_should_disable(struct sock *sk)
+ void tcp_fastopen_active_disable_ofo_check(struct sock *sk)
+ {
+ 	struct tcp_sock *tp = tcp_sk(sk);
+-	struct rb_node *p;
+-	struct sk_buff *skb;
+ 	struct dst_entry *dst;
++	struct sk_buff *skb;
+ 
+ 	if (!tp->syn_fastopen)
+ 		return;
+ 
+ 	if (!tp->data_segs_in) {
+-		p = rb_first(&tp->out_of_order_queue);
+-		if (p && !rb_next(p)) {
+-			skb = rb_entry(p, struct sk_buff, rbnode);
++		skb = skb_rb_first(&tp->out_of_order_queue);
++		if (skb && !skb_rb_next(skb)) {
+ 			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
+ 				tcp_fastopen_active_disable(sk);
+ 				return;
+diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
+index fb0d7ed84b94..90afe4143596 100644
+--- a/net/ipv4/tcp_input.c
++++ b/net/ipv4/tcp_input.c
+@@ -4335,7 +4335,7 @@ static void tcp_ofo_queue(struct sock *sk)
+ 
+ 	p = rb_first(&tp->out_of_order_queue);
+ 	while (p) {
+-		skb = rb_entry(p, struct sk_buff, rbnode);
++		skb = rb_to_skb(p);
+ 		if (after(TCP_SKB_CB(skb)->seq, tp->rcv_nxt))
+ 			break;
+ 
+@@ -4399,7 +4399,7 @@ static int tcp_try_rmem_schedule(struct sock *sk, struct sk_buff *skb,
+ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
+ {
+ 	struct tcp_sock *tp = tcp_sk(sk);
+-	struct rb_node **p, *q, *parent;
++	struct rb_node **p, *parent;
+ 	struct sk_buff *skb1;
+ 	u32 seq, end_seq;
+ 	bool fragstolen;
+@@ -4458,7 +4458,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
+ 	parent = NULL;
+ 	while (*p) {
+ 		parent = *p;
+-		skb1 = rb_entry(parent, struct sk_buff, rbnode);
++		skb1 = rb_to_skb(parent);
+ 		if (before(seq, TCP_SKB_CB(skb1)->seq)) {
+ 			p = &parent->rb_left;
+ 			continue;
+@@ -4503,9 +4503,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
+ 
+ merge_right:
+ 	/* Remove other segments covered by skb. */
+-	while ((q = rb_next(&skb->rbnode)) != NULL) {
+-		skb1 = rb_entry(q, struct sk_buff, rbnode);
+-
++	while ((skb1 = skb_rb_next(skb)) != NULL) {
+ 		if (!after(end_seq, TCP_SKB_CB(skb1)->seq))
+ 			break;
+ 		if (before(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
+@@ -4520,7 +4518,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
+ 		tcp_drop(sk, skb1);
+ 	}
+ 	/* If there is no skb after us, we are the last_skb ! */
+-	if (!q)
++	if (!skb1)
+ 		tp->ooo_last_skb = skb;
+ 
+ add_sack:
+@@ -4706,7 +4704,7 @@ static struct sk_buff *tcp_skb_next(struct sk_buff *skb, struct sk_buff_head *li
+ 	if (list)
+ 		return !skb_queue_is_last(list, skb) ? skb->next : NULL;
+ 
+-	return rb_entry_safe(rb_next(&skb->rbnode), struct sk_buff, rbnode);
++	return skb_rb_next(skb);
+ }
+ 
+ static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb,
+@@ -4735,7 +4733,7 @@ static void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb)
+ 
+ 	while (*p) {
+ 		parent = *p;
+-		skb1 = rb_entry(parent, struct sk_buff, rbnode);
++		skb1 = rb_to_skb(parent);
+ 		if (before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb1)->seq))
+ 			p = &parent->rb_left;
+ 		else
+@@ -4854,26 +4852,19 @@ static void tcp_collapse_ofo_queue(struct sock *sk)
+ {
+ 	struct tcp_sock *tp = tcp_sk(sk);
+ 	struct sk_buff *skb, *head;
+-	struct rb_node *p;
+ 	u32 start, end;
+ 
+-	p = rb_first(&tp->out_of_order_queue);
+-	skb = rb_entry_safe(p, struct sk_buff, rbnode);
++	skb = skb_rb_first(&tp->out_of_order_queue);
+ new_range:
+ 	if (!skb) {
+-		p = rb_last(&tp->out_of_order_queue);
+-		/* Note: This is possible p is NULL here. We do not
+-		 * use rb_entry_safe(), as ooo_last_skb is valid only
+-		 * if rbtree is not empty.
+-		 */
+-		tp->ooo_last_skb = rb_entry(p, struct sk_buff, rbnode);
++		tp->ooo_last_skb = skb_rb_last(&tp->out_of_order_queue);
+ 		return;
+ 	}
+ 	start = TCP_SKB_CB(skb)->seq;
+ 	end = TCP_SKB_CB(skb)->end_seq;
+ 
+ 	for (head = skb;;) {
+-		skb = tcp_skb_next(skb, NULL);
++		skb = skb_rb_next(skb);
+ 
+ 		/* Range is terminated when we see a gap or when
+ 		 * we are at the queue end.
+@@ -4916,14 +4907,14 @@ static bool tcp_prune_ofo_queue(struct sock *sk)
+ 	do {
+ 		prev = rb_prev(node);
+ 		rb_erase(node, &tp->out_of_order_queue);
+-		tcp_drop(sk, rb_entry(node, struct sk_buff, rbnode));
++		tcp_drop(sk, rb_to_skb(node));
+ 		sk_mem_reclaim(sk);
+ 		if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
+ 		    !tcp_under_memory_pressure(sk))
+ 			break;
+ 		node = prev;
+ 	} while (node);
+-	tp->ooo_last_skb = rb_entry(prev, struct sk_buff, rbnode);
++	tp->ooo_last_skb = rb_to_skb(prev);
+ 
+ 	/* Reset SACK state.  A conforming SACK implementation will
+ 	 * do the same at a timeout based retransmit.  When a connection
+diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
+index 5a4f10080290..db0228a65e8c 100644
+--- a/net/sched/sch_netem.c
++++ b/net/sched/sch_netem.c
+@@ -148,12 +148,6 @@ struct netem_skb_cb {
+ 	psched_time_t	time_to_send;
+ };
+ 
+-
+-static struct sk_buff *netem_rb_to_skb(struct rb_node *rb)
+-{
+-	return rb_entry(rb, struct sk_buff, rbnode);
+-}
+-
+ static inline struct netem_skb_cb *netem_skb_cb(struct sk_buff *skb)
+ {
+ 	/* we assume we can use skb next/prev/tstamp as storage for rb_node */
+@@ -364,7 +358,7 @@ static void tfifo_reset(struct Qdisc *sch)
+ 	struct rb_node *p = rb_first(&q->t_root);
+ 
+ 	while (p) {
+-		struct sk_buff *skb = netem_rb_to_skb(p);
++		struct sk_buff *skb = rb_to_skb(p);
+ 
+ 		p = rb_next(p);
+ 		rb_erase(&skb->rbnode, &q->t_root);
+@@ -382,7 +376,7 @@ static void tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
+ 		struct sk_buff *skb;
+ 
+ 		parent = *p;
+-		skb = netem_rb_to_skb(parent);
++		skb = rb_to_skb(parent);
+ 		if (tnext >= netem_skb_cb(skb)->time_to_send)
+ 			p = &parent->rb_right;
+ 		else
+@@ -538,7 +532,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+ 				struct sk_buff *t_skb;
+ 				struct netem_skb_cb *t_last;
+ 
+-				t_skb = netem_rb_to_skb(rb_last(&q->t_root));
++				t_skb = skb_rb_last(&q->t_root);
+ 				t_last = netem_skb_cb(t_skb);
+ 				if (!last ||
+ 				    t_last->time_to_send > last->time_to_send) {
+@@ -617,7 +611,7 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch)
+ 	if (p) {
+ 		psched_time_t time_to_send;
+ 
+-		skb = netem_rb_to_skb(p);
++		skb = rb_to_skb(p);
+ 
+ 		/* if more time remaining? */
+ 		time_to_send = netem_skb_cb(skb)->time_to_send;
+-- 
+2.15.0
+
diff --git a/queue/series b/queue/series
index c0ba19c..a0578e6 100644
--- a/queue/series
+++ b/queue/series
@@ -71,6 +71,7 @@ drm-sun4i-Fix-error-path-handling.patch
 libnvdimm-dax-fix-1GB-aligned-namespaces-vs-physical.patch
 libnvdimm-btt-Fix-an-incompatibility-in-the-log-layo.patch
 libnvdimm-pfn-fix-start_pad-handling-for-aligned-nam.patch
+net-add-rb_to_skb-and-other-rb-tree-helpers.patch
 tcp-free-batches-of-packets-in-tcp_prune_ofo_queue.patch
 tcp-avoid-collapses-in-tcp_prune_queue-if-possible.patch
 tcp-detect-malicious-patterns-in-tcp_collapse_ofo_qu.patch