netdev - [PATCH net-next 3/6] mptcp: don't clear MPTCP_DATA_READY in sk_wait

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Date:   Mon, 21 Jun 2021 15:54:35 -0700
From:   Mat Martineau <mathew.j.martineau@...ux.intel.com>
To:     netdev@...r.kernel.org
Cc:     Paolo Abeni <pabeni@...hat.com>, davem@...emloft.net,
        kuba@...nel.org, matthieu.baerts@...sares.net,
        mptcp@...ts.linux.dev,
        Mat Martineau <mathew.j.martineau@...ux.intel.com>
Subject: [PATCH net-next 3/6] mptcp: don't clear MPTCP_DATA_READY in sk_wait_event()

From: Paolo Abeni <pabeni@...hat.com>

If we don't flush entirely the receive queue, we need set
again such bit later. We can simply avoid clearing it.

Signed-off-by: Paolo Abeni <pabeni@...hat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@...ux.intel.com>
---
 net/mptcp/protocol.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index c47ce074737d..3e088e9d20fd 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1715,7 +1715,7 @@ static void mptcp_wait_data(struct sock *sk, long *timeo)
 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 
 	sk_wait_event(sk, timeo,
-		      test_and_clear_bit(MPTCP_DATA_READY, &msk->flags), &wait);
+		      test_bit(MPTCP_DATA_READY, &msk->flags), &wait);
 
 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 	remove_wait_queue(sk_sleep(sk), &wait);
@@ -2039,10 +2039,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 		 */
 		if (unlikely(__mptcp_move_skbs(msk)))
 			set_bit(MPTCP_DATA_READY, &msk->flags);
-	} else if (unlikely(!test_bit(MPTCP_DATA_READY, &msk->flags))) {
-		/* data to read but mptcp_wait_data() cleared DATA_READY */
-		set_bit(MPTCP_DATA_READY, &msk->flags);
 	}
+
 out_err:
 	if (cmsg_flags && copied >= 0) {
 		if (cmsg_flags & MPTCP_CMSG_TS)
-- 
2.32.0