From: Paolo Abeni <pabeni@redhat.com>

MPTCP will soon need the same functionality for passive sockets,
factor them out in a common helper. No functional change intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/protocol.h |  2 ++
 net/mptcp/subflow.c  | 20 ++++++++++++--------
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index a23780ff670f..6d9de13c1f9c 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -707,6 +707,8 @@ mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
 	return ret;
 }
 
+void __mptcp_inherit_cgrp_data(struct sock *sk, struct sock *ssk);
+
 int mptcp_is_enabled(const struct net *net);
 unsigned int mptcp_get_add_addr_timeout(const struct net *net);
 int mptcp_is_checksum_enabled(const struct net *net);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index ddd0fc6fcf45..d98d151392d2 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1712,21 +1712,25 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_pm_local *local,
 	return err;
 }
 
-static void mptcp_attach_cgroup(struct sock *parent, struct sock *child)
+void __mptcp_inherit_cgrp_data(struct sock *sk, struct sock *ssk)
 {
 #ifdef CONFIG_SOCK_CGROUP_DATA
-	struct sock_cgroup_data *parent_skcd = &parent->sk_cgrp_data,
-				*child_skcd = &child->sk_cgrp_data;
+	struct sock_cgroup_data *sk_cd = &sk->sk_cgrp_data,
+				*ssk_cd = &ssk->sk_cgrp_data;
 
 	/* only the additional subflows created by kworkers have to be modified */
-	if (cgroup_id(sock_cgroup_ptr(parent_skcd)) !=
-	    cgroup_id(sock_cgroup_ptr(child_skcd))) {
-		cgroup_sk_free(child_skcd);
-		*child_skcd = *parent_skcd;
-		cgroup_sk_clone(child_skcd);
+	if (cgroup_id(sock_cgroup_ptr(sk_cd)) !=
+	    cgroup_id(sock_cgroup_ptr(ssk_cd))) {
+		cgroup_sk_free(ssk_cd);
+		*ssk_cd = *sk_cd;
+		cgroup_sk_clone(sk_cd);
 	}
 #endif /* CONFIG_SOCK_CGROUP_DATA */
+}
 
+static void mptcp_attach_cgroup(struct sock *parent, struct sock *child)
+{
+	__mptcp_inherit_cgrp_data(parent, child);
 	if (mem_cgroup_sockets_enabled)
 		mem_cgroup_sk_inherit(parent, child);
 }

-- 
2.51.0