From 05dc72aba364d374a27de567fac58c199ff5ee97 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Fri, 12 Feb 2021 15:22:14 -0800
Subject: [PATCH] tcp: factorize logic into tcp_epollin_ready()
Both tcp_data_ready() and tcp_stream_is_readable() share the same logic.
Add tcp_epollin_ready() helper to avoid duplication.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/net/tcp.h | 12 ++++++++++++
net/ipv4/tcp.c | 18 +++++-------------
net/ipv4/tcp_input.c | 11 ++---------
3 files changed, 19 insertions(+), 22 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 244208f6f6c2a..484eb2362645f 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1442,6 +1442,18 @@ static inline bool tcp_rmem_pressure(const struct sock *sk)
return atomic_read(&sk->sk_rmem_alloc) > threshold;
}
+static inline bool tcp_epollin_ready(const struct sock *sk, int target)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq);
+
+ if (avail <= 0)
+ return false;
+
+ return (avail >= target) || tcp_rmem_pressure(sk) ||
+ (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss);
+}
+
extern void tcp_openreq_init_rwin(struct request_sock *req,
const struct sock *sk_listener,
const struct dst_entry *dst);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 9896ca10bb340..7a6b58ae408d1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -481,19 +481,11 @@ static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
}
}
-static inline bool tcp_stream_is_readable(const struct tcp_sock *tp,
- int target, struct sock *sk)
+static bool tcp_stream_is_readable(struct sock *sk, int target)
{
- int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq);
-
- if (avail > 0) {
- if (avail >= target)
- return true;
- if (tcp_rmem_pressure(sk))
- return true;
- if (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss)
- return true;
- }
+ if (tcp_epollin_ready(sk, target))
+ return true;
+
if (sk->sk_prot->stream_memory_read)
return sk->sk_prot->stream_memory_read(sk);
return false;
@@ -568,7 +560,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
tp->urg_data)
target++;
- if (tcp_stream_is_readable(tp, target, sk))
+ if (tcp_stream_is_readable(sk, target))
mask |= EPOLLIN | EPOLLRDNORM;
if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a8f8f98159531..e32a7056cb764 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4924,15 +4924,8 @@ int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
void tcp_data_ready(struct sock *sk)
{
- const struct tcp_sock *tp = tcp_sk(sk);
- int avail = tp->rcv_nxt - tp->copied_seq;
-
- if (avail < sk->sk_rcvlowat && !tcp_rmem_pressure(sk) &&
- !sock_flag(sk, SOCK_DONE) &&
- tcp_receive_window(tp) > inet_csk(sk)->icsk_ack.rcv_mss)
- return;
-
- sk->sk_data_ready(sk);
+ if (tcp_epollin_ready(sk, sk->sk_rcvlowat))
+ sk->sk_data_ready(sk);
}
static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
--
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