From 600911ff5f72baeac3fc6a9532ec8ba949cd818a Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 26 Feb 2020 10:14:49 +0100 Subject: [PATCH] mptcp: add rmem queue accounting If userspace never drains the receive buffers we must stop draining the subflow socket(s) at some point. This adds the needed rmem accouting for this. If the threshold is reached, we stop draining the subflows. Signed-off-by: Florian Westphal Reviewed-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index b4a8517d8eac..381d5647a95b 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -124,7 +124,7 @@ static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, struct sock *sk = (struct sock *)msk; __skb_unlink(skb, &ssk->sk_receive_queue); - skb_orphan(skb); + skb_set_owner_r(skb, sk); __skb_queue_tail(&sk->sk_receive_queue, skb); msk->ack_seq += copy_len; @@ -136,10 +136,16 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, unsigned int *bytes) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = (struct sock *)msk; unsigned int moved = 0; bool more_data_avail; struct tcp_sock *tp; bool done = false; + int rcvbuf; + + rcvbuf = max(ssk->sk_rcvbuf, sk->sk_rcvbuf); + if (rcvbuf > sk->sk_rcvbuf) + sk->sk_rcvbuf = rcvbuf; tp = tcp_sk(ssk); do { @@ -183,6 +189,11 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, WRITE_ONCE(tp->copied_seq, seq); more_data_avail = mptcp_subflow_data_available(ssk); + + if (atomic_read(&sk->sk_rmem_alloc) > READ_ONCE(sk->sk_rcvbuf)) { + done = true; + break; + } } while (more_data_avail); *bytes = moved; @@ -196,9 +207,14 @@ void mptcp_data_ready(struct sock *sk) set_bit(MPTCP_DATA_READY, &msk->flags); + /* don't schedule if mptcp sk is (still) over limit */ + if (atomic_read(&sk->sk_rmem_alloc) > READ_ONCE(sk->sk_rcvbuf)) + goto wake; + if (schedule_work(&msk->work)) sock_hold((struct sock *)msk); +wake: sk->sk_data_ready(sk); }