Commit 58152ecb authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: add tcp_ooo_try_coalesce() helper

In case skb in out_or_order_queue is the result of
multiple skbs coalescing, we would like to get a proper gso_segs
counter tracking, so that future tcp_drop() can report an accurate

I chose to not implement this tracking for skbs in receive queue,
since they are not dropped, unless socket is disconnected.
Signed-off-by: default avatarEric Dumazet <>
Acked-by: default avatarSoheil Hassas Yeganeh <>
Acked-by: default avatarYuchung Cheng <>
Signed-off-by: default avatarDavid S. Miller <>
parent 8541b21e
......@@ -4358,6 +4358,23 @@ static bool tcp_try_coalesce(struct sock *sk,
return true;
static bool tcp_ooo_try_coalesce(struct sock *sk,
struct sk_buff *to,
struct sk_buff *from,
bool *fragstolen)
bool res = tcp_try_coalesce(sk, to, from, fragstolen);
/* In case tcp_drop() is called later, update to->gso_segs */
if (res) {
u32 gso_segs = max_t(u16, 1, skb_shinfo(to)->gso_segs) +
max_t(u16, 1, skb_shinfo(from)->gso_segs);
skb_shinfo(to)->gso_segs = min_t(u32, gso_segs, 0xFFFF);
return res;
static void tcp_drop(struct sock *sk, struct sk_buff *skb)
sk_drops_add(sk, skb);
......@@ -4481,8 +4498,8 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
/* In the typical case, we are adding an skb to the end of the list.
* Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup.
if (tcp_try_coalesce(sk, tp->ooo_last_skb,
skb, &fragstolen)) {
if (tcp_ooo_try_coalesce(sk, tp->ooo_last_skb,
skb, &fragstolen)) {
tcp_grow_window(sk, skb);
kfree_skb_partial(skb, fragstolen);
......@@ -4532,8 +4549,8 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
tcp_drop(sk, skb1);
goto merge_right;
} else if (tcp_try_coalesce(sk, skb1,
skb, &fragstolen)) {
} else if (tcp_ooo_try_coalesce(sk, skb1,
skb, &fragstolen)) {
goto coalesce_done;
p = &parent->rb_right;
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