[net-next PATCH 2/2] tcp: Record Rx hash and NAPI ID in tcp_child_process

[Alexander Duyck]

From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>

While working on some recent busy poll changes we found that child sockets
were being instantiated without NAPI ID being set.  In our first attempt to
fix it, it was suggested that we should just pull programming the NAPI ID
into the function itself since all callers will need to have it set.

In addition to NAPI ID I have decided to also pull in populating the Rx
hash since it likely has the same problem as NAPI ID but just doesn't have
the visibility.

Reported-by: Sridhar Samudrala <sridhar.samudrala@xxxxxxxxx>
Suggested-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
---
 net/ipv4/tcp_ipv4.c      |    2 --
 net/ipv4/tcp_minisocks.c |    5 +++++
 net/ipv6/tcp_ipv6.c      |    2 --
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7482b5d11861..20cbd2f07f28 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1409,8 +1409,6 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 		if (!nsk)
 			goto discard;
 		if (nsk != sk) {
-			sock_rps_save_rxhash(nsk, skb);
-			sk_mark_napi_id(nsk, skb);
 			if (tcp_child_process(sk, nsk, skb)) {
 				rsk = nsk;
 				goto reset;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 692f974e5abe..245b63856c04 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -26,6 +26,7 @@
 #include <net/tcp.h>
 #include <net/inet_common.h>
 #include <net/xfrm.h>
+#include <net/busy_poll.h>
 
 int sysctl_tcp_abort_on_overflow __read_mostly;
 
@@ -798,6 +799,10 @@ int tcp_child_process(struct sock *parent, struct sock *child,
 	int ret = 0;
 	int state = child->sk_state;
 
+	/* record Rx hash and NAPI ID of child */
+	sock_rps_save_rxhash(child, skb);
+	sk_mark_napi_id(child, skb);
+
 	tcp_segs_in(tcp_sk(child), skb);
 	if (!sock_owned_by_user(child)) {
 		ret = tcp_rcv_state_process(child, skb);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 0f08d718a002..ee13e380c0dd 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1293,8 +1293,6 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 			goto discard;
 
 		if (nsk != sk) {
-			sock_rps_save_rxhash(nsk, skb);
-			sk_mark_napi_id(nsk, skb);
 			if (tcp_child_process(sk, nsk, skb))
 				goto reset;
 			if (opt_skb)