Messages in this thread Patch in this message | | | From | jony-one <> | Subject | [PATCH] net/mlx4: tcp_drop replace of tcp_drop_new | Date | Sat, 21 Aug 2021 08:53:27 -0700 |
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We never know why we are deleting a tcp packet when we delete it, and the tcp_drop_new() function can effectively solve this problem. The tcp_drop_new() will learn from the specified status code why the packet was deleted, and the caller from whom the packet was deleted. The kernel should be a little more open to data that is about to be destroyed and useless, and users should be able to keep track of it.
Signed-off-by: jony-one <yan2228598786@gmail.com> --- include/trace/events/tcp.h | 51 ++++++++++++++++++++++++++++++++++++++ net/ipv4/tcp_input.c | 29 ++++++++++++++-------- 2 files changed, 69 insertions(+), 11 deletions(-)
diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h index 521059d8d..5a0478440 100644 --- a/include/trace/events/tcp.h +++ b/include/trace/events/tcp.h @@ -371,6 +371,57 @@ DEFINE_EVENT(tcp_event_skb, tcp_bad_csum, TP_ARGS(skb) ); +/* + * tcp event whit argument sk, skb, reason + */ +TRACE_EVENT(tcp_drop_new, + + TP_PROTO(struct sock *sk, struct sk_buff *skb, const char *reason), + + TP_ARGS(sk, skb, reason), + + TP_STRUCT__entry( + __field(const void *, skbaddr) + __field(const void *, skaddr) + __string(reason, reason) + __field(int, state) + __field(__u16, sport) + __field(__u16, dport) + __array(__u8, saddr, 4) + __array(__u8, daddr, 4) + __array(__u8, saddr_v6, 16) + __array(__u8, daddr_v6, 16) + ), + + TP_fast_assign( + struct inet_sock *inet = inet_sk(sk); + __be32 *p32; + + __assign_str(reason, reason); + + __entry->skbaddr = skb; + __entry->skaddr = sk; + __entry->state = sk->sk_state; + + __entry->sport = ntohs(inet->inet_sport); + __entry->dport = ntohs(inet->inet_dport); + + p32 = (__be32 *) __entry->saddr; + *p32 = inet->inet_saddr; + + p32 = (__be32 *) __entry->daddr; + *p32 = inet->inet_daddr; + + TP_STORE_ADDRS(__entry, inet->inet_saddr, inet->inet_daddr, + sk->sk_v6_rcv_saddr, sk->sk_v6_daddr); + ), + + TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c state=%s reason=%s", + __entry->sport, __entry->dport, __entry->saddr, __entry->daddr, + __entry->saddr_v6, __entry->daddr_v6, + show_tcp_state_name(__entry->state), __get_str(reason)) +); + #endif /* _TRACE_TCP_H */ /* This part must be outside protection */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 149ceb5c9..988989e25 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4649,6 +4649,13 @@ static void tcp_drop(struct sock *sk, struct sk_buff *skb) __kfree_skb(skb); } +static void tcp_drop_new(struct sock *sk, struct sk_buff *skb, const char *reason) +{ + trace_tcp_drop_new(sk, skb, reason); + sk_drops_add(sk, skb); + __kfree_skb(skb); +} + /* This one checks to see if we can put data from the * out_of_order queue into the receive_queue. */ @@ -4676,7 +4683,7 @@ static void tcp_ofo_queue(struct sock *sk) rb_erase(&skb->rbnode, &tp->out_of_order_queue); if (unlikely(!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))) { - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); continue; } @@ -4732,7 +4739,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) { NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFODROP); sk->sk_data_ready(sk); - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); return; } @@ -4795,7 +4802,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) /* All the bits are present. Drop. */ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE); - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); skb = NULL; tcp_dsack_set(sk, seq, end_seq); goto add_sack; @@ -4814,7 +4821,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) TCP_SKB_CB(skb1)->end_seq); NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE); - tcp_drop(sk, skb1); + tcp_drop_new(sk, skb1, __func__); goto merge_right; } } else if (tcp_ooo_try_coalesce(sk, skb1, @@ -4842,7 +4849,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq, TCP_SKB_CB(skb1)->end_seq); NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE); - tcp_drop(sk, skb1); + tcp_drop_new(sk, skb1, __func__); } /* If there is no skb after us, we are the last_skb ! */ if (!skb1) @@ -5019,7 +5026,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS); inet_csk_schedule_ack(sk); drop: - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); return; } @@ -5276,7 +5283,7 @@ static bool tcp_prune_ofo_queue(struct sock *sk) prev = rb_prev(node); rb_erase(node, &tp->out_of_order_queue); goal -= rb_to_skb(node)->truesize; - tcp_drop(sk, rb_to_skb(node)); + tcp_drop_new(sk, rb_to_skb(node), __func__); if (!prev || goal <= 0) { sk_mem_reclaim(sk); if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && @@ -5701,7 +5708,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb, return true; discard: - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); return false; } @@ -5905,7 +5912,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb) TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); discard: - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); } EXPORT_SYMBOL(tcp_rcv_established); @@ -6196,7 +6203,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, TCP_DELACK_MAX, TCP_RTO_MAX); discard: - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); return 0; } else { tcp_send_ack(sk); @@ -6568,7 +6575,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) if (!queued) { discard: - tcp_drop(sk, skb); + tcp_drop_new(sk, skb, __func__); } return 0; } -- 2.25.1
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