Merge "tcp: avoid collapses in tcp_prune_queue() if possible" (db0ca87a) · Commits · e / devices / android_kernel_fairphone_FP3

include/linux/skbuff.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -2986,6 +2986,8 @@ 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_queue_walk(queue, skb) \
		for (skb = (queue)->next; \
		skb != (struct sk_buff *)(queue); \

+14 −4

Original line number	Diff line number	Diff line
		@@ -4956,6 +4956,7 @@ static void tcp_collapse_ofo_queue(struct sock *sk)
		* 2) not add too big latencies if thousands of packets sit there.
		* (But if application shrinks SO_RCVBUF, we could still end up
		* freeing whole queue here)
		* 3) Drop at least 12.5 % of sk_rcvbuf to avoid malicious attacks.
		*
		* Return true if queue has shrunk.
		*/
		@@ -4963,20 +4964,26 @@ static bool tcp_prune_ofo_queue(struct sock *sk)
		{
		struct tcp_sock *tp = tcp_sk(sk);
		struct rb_node node, prev;
		int goal;

		if (RB_EMPTY_ROOT(&tp->out_of_order_queue))
		return false;

		NET_INC_STATS(sock_net(sk), LINUX_MIB_OFOPRUNED);
		goal = sk->sk_rcvbuf >> 3;
		node = &tp->ooo_last_skb->rbnode;
		do {
		prev = rb_prev(node);
		rb_erase(node, &tp->out_of_order_queue);
		goal -= rb_to_skb(node)->truesize;
		tcp_drop(sk, rb_entry(node, struct sk_buff, rbnode));
		if (!prev \|\| goal <= 0) {
		sk_mem_reclaim(sk);
		if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
		!tcp_under_memory_pressure(sk))
		break;
		goal = sk->sk_rcvbuf >> 3;
		}
		node = prev;
		} while (node);
		tp->ooo_last_skb = rb_entry(prev, struct sk_buff, rbnode);
		@@ -5011,6 +5018,9 @@ static int tcp_prune_queue(struct sock *sk)
		else if (tcp_under_memory_pressure(sk))
		tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);

		if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
		return 0;

		tcp_collapse_ofo_queue(sk);
		if (!skb_queue_empty(&sk->sk_receive_queue))
		tcp_collapse(sk, &sk->sk_receive_queue, NULL,