From 9c3f94e1681bb0ebd93390f014082042d8bc067a Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Tue, 27 Oct 2020 15:59:14 +0100
Subject: [PATCH] mptcp: add missing memory scheduling in the rx path
When moving the skbs from the subflow into the msk receive
queue, we must schedule there the required amount of memory.
Try to borrow the required memory from the subflow, if needed,
so that we leverage the existing TCP heuristic.
Fixes: 6771bfd9ee24 ("mptcp: update mptcp ack sequence from work queue")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/f6143a6193a083574f11b00dbf7b5ad151bc4ff4.1603810630.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
net/mptcp/protocol.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 185dacb3978196..e7419fd15d84c9 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -274,6 +274,15 @@ static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
skb_ext_reset(skb);
skb_orphan(skb);
+ /* try to fetch required memory from subflow */
+ if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
+ if (ssk->sk_forward_alloc < skb->truesize)
+ goto drop;
+ __sk_mem_reclaim(ssk, skb->truesize);
+ if (!sk_rmem_schedule(sk, skb, skb->truesize))
+ goto drop;
+ }
+
/* the skb map_seq accounts for the skb offset:
* mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq
* value
@@ -301,6 +310,7 @@ static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
* will retransmit as needed, if needed.
*/
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
+drop:
mptcp_drop(sk, skb);
return false;
}
--
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