From: David Howells Date: Wed, 4 Dec 2024 07:47:06 +0000 (+0000) Subject: rxrpc: Fix request for an ACK when cwnd is minimum X-Git-Tag: v6.14-rc1~162^2~261^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4ee4c2f82b81c088d1514b04c28c84c15e98ba1a;p=thirdparty%2Fkernel%2Flinux.git rxrpc: Fix request for an ACK when cwnd is minimum rxrpc_prepare_data_subpacket() sets the REQUEST-ACK flag on the outgoing DATA packet under a number of circumstances, including, theoretically, when the cwnd is at minimum (or less). However, the minimum in this function is hard-coded as 2, but the actual minimum is RXRPC_MIN_CWND (which is currently 4) and so this never occurs. Without this, we will miss the request of some ACKs, potentially leading to a transmission stall until a timeout occurs on one side or the other that leads to an ACK being generated. Fix the function to use RXRPC_MIN_CWND rather than a hard-coded number. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Jakub Kicinski --- diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index ecaf3becee40d..f934551a9b1c6 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -469,7 +469,7 @@ static size_t rxrpc_prepare_data_subpacket(struct rxrpc_call *call, why = rxrpc_reqack_ack_lost; else if (txb->flags & RXRPC_TXBUF_RESENT) why = rxrpc_reqack_retrans; - else if (call->cong_ca_state == RXRPC_CA_SLOW_START && call->cong_cwnd <= 2) + else if (call->cong_ca_state == RXRPC_CA_SLOW_START && call->cong_cwnd <= RXRPC_MIN_CWND) why = rxrpc_reqack_slow_start; else if (call->tx_winsize <= 2) why = rxrpc_reqack_small_txwin;