1 files changed, 70 insertions, 53 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index fbde8b824e23..667c44aa5a63 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -608,36 +608,57 @@ unlock:
 }
 
 /*
- * Process a requested ACK.
+ * See if there's a cached RTT probe to complete.
  */
-static void rxrpc_input_requested_ack(struct rxrpc_call *call,
-				      ktime_t resp_time,
-				      rxrpc_serial_t orig_serial,
-				      rxrpc_serial_t ack_serial)
+static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
+				     ktime_t resp_time,
+				     rxrpc_serial_t acked_serial,
+				     rxrpc_serial_t ack_serial,
+				     enum rxrpc_rtt_rx_trace type)
 {
-	struct rxrpc_skb_priv *sp;
-	struct sk_buff *skb;
+	rxrpc_serial_t orig_serial;
+	unsigned long avail;
 	ktime_t sent_at;
-	int ix;
+	bool matched = false;
+	int i;
 
-	for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
-		skb = call->rxtx_buffer[ix];
-		if (!skb)
-			continue;
+	avail = READ_ONCE(call->rtt_avail);
+	smp_rmb(); /* Read avail bits before accessing data. */
 
-		sent_at = skb->tstamp;
-		smp_rmb(); /* Read timestamp before serial. */
-		sp = rxrpc_skb(skb);
-		if (sp->hdr.serial != orig_serial)
+	for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) {
+		if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
 			continue;
-		goto found;
-	}
 
-	return;
+		sent_at = call->rtt_sent_at[i];
+		orig_serial = call->rtt_serial[i];
+
+		if (orig_serial == acked_serial) {
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_mb(); /* Read data before setting avail bit */
+			set_bit(i, &call->rtt_avail);
+			if (type != rxrpc_rtt_rx_cancel)
+				rxrpc_peer_add_rtt(call, type, i, acked_serial, ack_serial,
+						   sent_at, resp_time);
+			else
+				trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_cancel, i,
+						   orig_serial, acked_serial, 0, 0);
+			matched = true;
+		}
+
+		/* If a later serial is being acked, then mark this slot as
+		 * being available.
+		 */
+		if (after(acked_serial, orig_serial)) {
+			trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i,
+					   orig_serial, acked_serial, 0, 0);
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_wmb();
+			set_bit(i, &call->rtt_avail);
+		}
+	}
 
-found:
-	rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
-			   orig_serial, ack_serial, sent_at, resp_time);
+	if (!matched)
+		trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0);
 }
 
 /*
@@ -682,27 +703,11 @@ static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
  */
 static void rxrpc_input_ping_response(struct rxrpc_call *call,
 				      ktime_t resp_time,
-				      rxrpc_serial_t orig_serial,
+				      rxrpc_serial_t acked_serial,
 				      rxrpc_serial_t ack_serial)
 {
-	rxrpc_serial_t ping_serial;
-	ktime_t ping_time;
-
-	ping_time = call->ping_time;
-	smp_rmb();
-	ping_serial = READ_ONCE(call->ping_serial);
-
-	if (orig_serial == call->acks_lost_ping)
+	if (acked_serial == call->acks_lost_ping)
 		rxrpc_input_check_for_lost_ack(call);
-
-	if (before(orig_serial, ping_serial) ||
-	    !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags))
-		return;
-	if (after(orig_serial, ping_serial))
-		return;
-
-	rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
-			   orig_serial, ack_serial, ping_time, resp_time);
 }
 
 /*
@@ -843,7 +848,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 		struct rxrpc_ackinfo info;
 		u8 acks[RXRPC_MAXACKS];
 	} buf;
-	rxrpc_serial_t acked_serial;
+	rxrpc_serial_t ack_serial, acked_serial;
 	rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
 	int nr_acks, offset, ioffset;
 
@@ -856,6 +861,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	}
 	offset += sizeof(buf.ack);
 
+	ack_serial = sp->hdr.serial;
 	acked_serial = ntohl(buf.ack.serial);
 	first_soft_ack = ntohl(buf.ack.firstPacket);
 	prev_pkt = ntohl(buf.ack.previousPacket);
@@ -864,31 +870,42 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
 			      buf.ack.reason : RXRPC_ACK__INVALID);
 
-	trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
+	trace_rxrpc_rx_ack(call, ack_serial, acked_serial,
 			   first_soft_ack, prev_pkt,
 			   summary.ack_reason, nr_acks);
 
-	if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
+	switch (buf.ack.reason) {
+	case RXRPC_ACK_PING_RESPONSE:
 		rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
-					  sp->hdr.serial);
-	if (buf.ack.reason == RXRPC_ACK_REQUESTED)
-		rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
-					  sp->hdr.serial);
+					  ack_serial);
+		rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+					 rxrpc_rtt_rx_ping_response);
+		break;
+	case RXRPC_ACK_REQUESTED:
+		rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+					 rxrpc_rtt_rx_requested_ack);
+		break;
+	default:
+		if (acked_serial != 0)
+			rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+						 rxrpc_rtt_rx_cancel);
+		break;
+	}
 
 	if (buf.ack.reason == RXRPC_ACK_PING) {
-		_proto("Rx ACK %%%u PING Request", sp->hdr.serial);
+		_proto("Rx ACK %%%u PING Request", ack_serial);
 		rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
-				  sp->hdr.serial, true, true,
+				  ack_serial, true, true,
 				  rxrpc_propose_ack_respond_to_ping);
 	} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
 		rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
-				  sp->hdr.serial, true, true,
+				  ack_serial, true, true,
 				  rxrpc_propose_ack_respond_to_ack);
 	}
 
 	/* Discard any out-of-order or duplicate ACKs (outside lock). */
 	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
-		trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial,
+		trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
 					   first_soft_ack, call->ackr_first_seq,
 					   prev_pkt, call->ackr_prev_seq);
 		return;
@@ -904,7 +921,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 
 	/* Discard any out-of-order or duplicate ACKs (inside lock). */
 	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
-		trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial,
+		trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
 					   first_soft_ack, call->ackr_first_seq,
 					   prev_pkt, call->ackr_prev_seq);
 		goto out;
@@ -964,7 +981,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	    RXRPC_TX_ANNO_LAST &&
 	    summary.nr_acks == call->tx_top - hard_ack &&
 	    rxrpc_is_client_call(call))
-		rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, ack_serial,
 				  false, true,
 				  rxrpc_propose_ack_ping_for_lost_reply);