[PATCH 14/33] tcp: add tcp_sock_set_quickack

Christoph Hellwig
2020-05-20T19:59:56Z

Add a helper to directly set the TCP_QUICKACK sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/block/drbd/drbd_int.h | 7 ------
drivers/block/drbd/drbd_receiver.c | 5 ++--
include/linux/tcp.h | 1 +
net/ipv4/tcp.c | 39 ++++++++++++++++++++----------
4 files changed, 29 insertions(+), 23 deletions(-)

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index e24bba87c8e02..14345a87c7cc5 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1570,13 +1570,6 @@ extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled);
extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed);
extern int drbd_connected(struct drbd_peer_device *);

-static inline void drbd_tcp_quickack(struct socket *sock)
-{
- int val = 2;
- (void) kernel_setsockopt(sock, SOL_TCP, TCP_QUICKACK,
- (char*)&val, sizeof(val));
-}
-
/* sets the number of 512 byte sectors of our virtual device */
void drbd_set_my_capacity(struct drbd_device *device, sector_t size);

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 20a5e94494acd..3a3f2b6a821f3 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1223,7 +1223,7 @@ static int drbd_recv_header_maybe_unplug(struct drbd_connection *connection, str
* quickly as possible, and let remote TCP know what we have
* received so far. */
if (err == -EAGAIN) {
- drbd_tcp_quickack(connection->data.socket);
+ tcp_sock_set_quickack(connection->data.socket->sk, 2);
drbd_unplug_all_devices(connection);
}
if (err > 0) {
@@ -4959,8 +4959,7 @@ static int receive_UnplugRemote(struct drbd_connection *connection, struct packe
{
/* Make sure we've acked all the TCP data associated
* with the data requests being unplugged */
- drbd_tcp_quickack(connection->data.socket);
-
+ tcp_sock_set_quickack(connection->data.socket->sk, 2);
return 0;
}

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 9e42c7fe50a8b..2eaf8320b9db0 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -499,5 +499,6 @@ int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount,

void tcp_sock_set_cork(struct sock *sk, bool on);
void tcp_sock_set_nodelay(struct sock *sk);
+void tcp_sock_set_quickack(struct sock *sk, int val);

#endif /* _LINUX_TCP_H */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index a65f293a19fac..27b5e7a4e2ef9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2856,6 +2856,31 @@ void tcp_sock_set_nodelay(struct sock *sk)
}
EXPORT_SYMBOL(tcp_sock_set_nodelay);

+static void __tcp_sock_set_quickack(struct sock *sk, int val)
+{
+ if (!val) {
+ inet_csk_enter_pingpong_mode(sk);
+ return;
+ }
+
+ inet_csk_exit_pingpong_mode(sk);
+ if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
+ inet_csk_ack_scheduled(sk)) {
+ inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_PUSHED;
+ tcp_cleanup_rbuf(sk, 1);
+ if (!(val & 1))
+ inet_csk_enter_pingpong_mode(sk);
+ }
+}
+
+void tcp_sock_set_quickack(struct sock *sk, int val)
+{
+ lock_sock(sk);
+ __tcp_sock_set_quickack(sk, val);
+ release_sock(sk);
+}
+EXPORT_SYMBOL(tcp_sock_set_quickack);
+
/*
* Socket option code for TCP.
*/
@@ -3096,19 +3121,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
break;

case TCP_QUICKACK:
- if (!val) {
- inet_csk_enter_pingpong_mode(sk);
- } else {
- inet_csk_exit_pingpong_mode(sk);
- if ((1 << sk->sk_state) &
- (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
- inet_csk_ack_scheduled(sk)) {
- icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
- tcp_cleanup_rbuf(sk, 1);
- if (!(val & 1))
- inet_csk_enter_pingpong_mode(sk);
- }
- }
+ __tcp_sock_set_quickack(sk, val);
break;

#ifdef CONFIG_TCP_MD5SIG
--
2.26.2