[PATCH net v2 15/15] mptcp: avoid pruning for OoW data

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

From: Paolo Abeni <pabeni@redhat.com>

Pruning is expansive and destructive, do it only when we expect
to accept the skb triggering the cleanup.

Fixes: e468d371180d ("mptcp: implemented OoO queue pruning")
Cc: stable@vger.kernel.org
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>
---
 net/mptcp/protocol.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 4309fca6b119..0098e2830931 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -313,12 +313,6 @@ static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb)
 	u64 seq, end_seq, max_seq;
 	struct sk_buff *skb1;
 
-	if (!mptcp_try_rmem_schedule(sk, skb)) {
-		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
-		mptcp_drop(sk, skb);
-		return;
-	}
-
 	seq = MPTCP_SKB_CB(skb)->map_seq;
 	end_seq = MPTCP_SKB_CB(skb)->end_seq;
 	max_seq = atomic64_read(&msk->rcv_wnd_sent);
@@ -335,6 +329,12 @@ static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb)
 		return;
 	}
 
+	if (!mptcp_try_rmem_schedule(sk, skb)) {
+		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
+		mptcp_drop(sk, skb);
+		return;
+	}
+
 	p = &msk->out_of_order_queue.rb_node;
 	MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUE);
 	if (RB_EMPTY_ROOT(&msk->out_of_order_queue)) {

-- 
2.55.0