[PATCH 6.12.y 2/5] mptcp: remove unneeded READ_ONCE() annotation

["Matthieu Baerts (NGI0)" <matttbe@kernel.org>]

From: Paolo Abeni <pabeni@redhat.com>

commit caa4a79f74f32084ce28aee8653bc04df745970d upstream.

The subflow->fully_established flag is always written under the subflow
socket lock. Reading such value under the same lock does not require any
ONCE annotation.

Fixes: 581c8cbfa934 ("mptcp: annotate data-races around subflow->fully_established")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260908-net-mptcp-misc-fixes-7-3-rc1-v2-10-df1de70348b6@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 2b0f561f21b2 ("mptcp: avoid unneeded actions on subflow reset")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/options.c  | 4 ++--
 net/mptcp/protocol.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 123c3691833f..d238dd374ce9 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -532,7 +532,7 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb,
 		return false;
 
 	/* MPC/MPJ needed only on 3rd ack packet, DATA_FIN and TCP shutdown take precedence */
-	if (READ_ONCE(subflow->fully_established) || snd_data_fin_enable ||
+	if (subflow->fully_established || snd_data_fin_enable ||
 	    subflow->snd_isn != TCP_SKB_CB(skb)->seq ||
 	    sk->sk_state != TCP_ESTABLISHED)
 		return false;
@@ -999,7 +999,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
 	/* here we can process OoO, in-window pkts, only in-sequence 4th ack
 	 * will make the subflow fully established
 	 */
-	if (likely(READ_ONCE(subflow->fully_established))) {
+	if (likely(subflow->fully_established)) {
 		/* on passive sockets, check for 3rd ack retransmission
 		 * note that msk is always set by subflow_syn_recv_sock()
 		 * for mp_join subflows
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index a4054ed24605..2f34e92d9cce 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3685,7 +3685,7 @@ static void schedule_3rdack_retransmission(struct sock *ssk)
 	struct tcp_sock *tp = tcp_sk(ssk);
 	unsigned long timeout;
 
-	if (READ_ONCE(mptcp_subflow_ctx(ssk)->fully_established))
+	if (mptcp_subflow_ctx(ssk)->fully_established)
 		return;
 
 	/* reschedule with a timeout above RTT, as we must look only for drop */
-- 
2.55.0