rxrpc: Add tracepoint for ACK proposal

Add a tracepoint to log proposed ACKs, including whether the proposal is
used to update a pending ACK or is discarded in favour of an easlier,
higher priority ACK.

Whilst we're at it, get rid of the rxrpc_acks() function and access the
name array directly.  We do, however, need to validate the ACK reason
number given to trace_rxrpc_rx_ack() to make sure we don't overrun the
array.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 19 insertions, 11 deletions

diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
index fa9942fabdf2..1ca14835d87f 100644
--- a/net/rxrpc/misc.c
+++ b/net/rxrpc/misc.c
@@ -91,17 +91,10 @@ const s8 rxrpc_ack_priority[] = {
 	[RXRPC_ACK_PING]		= 9,
 };
 
-const char *rxrpc_acks(u8 reason)
-{
-	static const char *const str[] = {
-		"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
-		"IDL", "-?-"
-	};
-
-	if (reason >= ARRAY_SIZE(str))
-		reason = ARRAY_SIZE(str) - 1;
-	return str[reason];
-}
+const char const rxrpc_ack_names[RXRPC_ACK__INVALID + 1][4] = {
+	"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
+	"IDL", "-?-"
+};
 
 const char rxrpc_skb_traces[rxrpc_skb__nr_trace][7] = {
 	[rxrpc_skb_rx_cleaned]		= "Rx CLN",
@@ -202,3 +195,18 @@ const char rxrpc_timer_traces[rxrpc_timer__nr_trace][8] = {
 	[rxrpc_timer_set_for_send]		= "SetTx ",
 	[rxrpc_timer_set_for_resend]		= "SetRTx",
 };
+
+const char rxrpc_propose_ack_traces[rxrpc_propose_ack__nr_trace][8] = {
+	[rxrpc_propose_ack_input_data]		= "DataIn ",
+	[rxrpc_propose_ack_ping_for_params]	= "Params ",
+	[rxrpc_propose_ack_respond_to_ack]	= "Rsp2Ack",
+	[rxrpc_propose_ack_respond_to_ping]	= "Rsp2Png",
+	[rxrpc_propose_ack_retry_tx]		= "RetryTx",
+	[rxrpc_propose_ack_terminal_ack]	= "ClTerm ",
+};
+
+const char *const rxrpc_propose_ack_outcomes[rxrpc_propose_ack__nr_outcomes] = {
+	[rxrpc_propose_ack_use]			= "",
+	[rxrpc_propose_ack_update]		= " Update",
+	[rxrpc_propose_ack_subsume]		= " Subsume",
+};