[PATCH net-next] tcp: introduce skb_rbtree_walk_safe() and use it in tcp_clean_rtx_queue()
From: Yafang Shao
Date: Wed Nov 28 2018 - 07:16:56 EST
When walk RB tree, we'd better use skb_rbtree_walk* helpers, that can make
the code more clear.
As skb_rbtree_walk() can't be used in tcp_clean_rtx_queue(), so the new
helper skb_rbtree_walk_safe() is introduced.
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
include/linux/skbuff.h | 5 +++++
net/ipv4/tcp_input.c | 5 ++---
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 73902ac..37ff792 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3256,6 +3256,11 @@ static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
for (skb = skb_rb_first(root); skb != NULL; \
skb = skb_rb_next(skb))
+#define skb_rbtree_walk_safe(skb, root, tmp) \
+ for (skb = skb_rb_first(root); \
+ tmp = skb ? skb_rb_next(skb) : NULL, skb != NULL; \
+ skb = tmp)
+
#define skb_rbtree_walk_from(skb) \
for (; skb != NULL; \
skb = skb_rb_next(skb))
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index f323978..ab6add2 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3043,7 +3043,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack,
struct tcp_sock *tp = tcp_sk(sk);
u32 prior_sacked = tp->sacked_out;
u32 reord = tp->snd_nxt; /* lowest acked un-retx un-sacked seq */
- struct sk_buff *skb, *next;
+ struct sk_buff *skb, *tmp;
bool fully_acked = true;
long sack_rtt_us = -1L;
long seq_rtt_us = -1L;
@@ -3055,7 +3055,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack,
first_ackt = 0;
- for (skb = skb_rb_first(&sk->tcp_rtx_queue); skb; skb = next) {
+ skb_rbtree_walk_safe(skb, &sk->tcp_rtx_queue, tmp) {
struct tcp_skb_cb *scb = TCP_SKB_CB(skb);
const u32 start_seq = scb->seq;
u8 sacked = scb->sacked;
@@ -3126,7 +3126,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack,
if (!fully_acked)
break;
- next = skb_rb_next(skb);
if (unlikely(skb == tp->retransmit_skb_hint))
tp->retransmit_skb_hint = NULL;
if (unlikely(skb == tp->lost_skb_hint))
--
1.8.3.1