rxrpc: Tidy up abort generation infrastructure

Tidy up the abort generation infrastructure in the following ways:

 (1) Create an enum and string mapping table to list the reasons an abort
     might be generated in tracing.

 (2) Replace the 3-char string with the values from (1) in the places that
     use that to log the abort source.  This gets rid of a memcpy() in the
     tracepoint.

 (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint
     and use values from (1) to indicate the trace reason.

 (4) Always make a call to an abort function at the point of the abort
     rather than stashing the values into variables and using goto to get
     to a place where it reported.  The C optimiser will collapse the calls
     together as appropriate.  The abort functions return a value that can
     be returned directly if appropriate.

Note that this extends into afs also at the points where that generates an
abort.  To aid with this, the afs sources need to #define
RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header
because they don't have access to the rxrpc internal structures that some
of the tracepoints make use of.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

1 files changed, 30 insertions, 35 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index bb4beb445325..bd69ff2d9082 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -9,10 +9,10 @@
 
 #include "ar-internal.h"
 
-static void rxrpc_proto_abort(const char *why,
-			      struct rxrpc_call *call, rxrpc_seq_t seq)
+static void rxrpc_proto_abort(struct rxrpc_call *call, rxrpc_seq_t seq,
+			      enum rxrpc_abort_reason why)
 {
-	rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG);
+	rxrpc_abort_call(call, seq, RX_PROTOCOL_ERROR, -EBADMSG, why);
 }
 
 /*
@@ -249,8 +249,8 @@ static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
  * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
  * or a final ACK packet.
  */
-static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
-			       const char *abort_why)
+static void rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
+			       enum rxrpc_abort_reason abort_why)
 {
 	unsigned int state;
 
@@ -283,13 +283,12 @@ static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
 	else
 		trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
 	_leave(" = ok");
-	return true;
+	return;
 
 bad_state:
 	write_unlock(&call->state_lock);
 	kdebug("end_tx %s", rxrpc_call_states[call->state]);
-	rxrpc_proto_abort(abort_why, call, call->tx_top);
-	return false;
+	rxrpc_proto_abort(call, call->tx_top, abort_why);
 }
 
 /*
@@ -311,11 +310,13 @@ static bool rxrpc_receiving_reply(struct rxrpc_call *call)
 
 	if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
 		if (!rxrpc_rotate_tx_window(call, top, &summary)) {
-			rxrpc_proto_abort("TXL", call, top);
+			rxrpc_proto_abort(call, top, rxrpc_eproto_early_reply);
 			return false;
 		}
 	}
-	return rxrpc_end_tx_phase(call, true, "ETD");
+
+	rxrpc_end_tx_phase(call, true, rxrpc_eproto_unexpected_reply);
+	return true;
 }
 
 static void rxrpc_input_update_ack_window(struct rxrpc_call *call,
@@ -365,17 +366,14 @@ static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb,
 
 	if (last) {
 		if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
-		    seq + 1 != wtop) {
-			rxrpc_proto_abort("LSN", call, seq);
-			return;
-		}
+		    seq + 1 != wtop)
+			return rxrpc_proto_abort(call, seq, rxrpc_eproto_different_last);
 	} else {
 		if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
 		    after_eq(seq, wtop)) {
 			pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n",
 				call->debug_id, seq, window, wtop, wlimit);
-			rxrpc_proto_abort("LSA", call, seq);
-			return;
+			return rxrpc_proto_abort(call, seq, rxrpc_eproto_data_after_last);
 		}
 	}
 
@@ -583,7 +581,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 		goto out_notify;
 
 	if (!rxrpc_input_split_jumbo(call, skb)) {
-		rxrpc_proto_abort("VLD", call, sp->hdr.seq);
+		rxrpc_proto_abort(call, sp->hdr.seq, rxrpc_badmsg_bad_jumbo);
 		goto out_notify;
 	}
 	skb = NULL;
@@ -764,7 +762,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 
 	offset = sizeof(struct rxrpc_wire_header);
 	if (skb_copy_bits(skb, offset, &ack, sizeof(ack)) < 0)
-		return rxrpc_proto_abort("XAK", call, 0);
+		return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack);
 	offset += sizeof(ack);
 
 	ack_serial = sp->hdr.serial;
@@ -844,7 +842,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	ioffset = offset + nr_acks + 3;
 	if (skb->len >= ioffset + sizeof(info) &&
 	    skb_copy_bits(skb, ioffset, &info, sizeof(info)) < 0)
-		return rxrpc_proto_abort("XAI", call, 0);
+		return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack_info);
 
 	if (nr_acks > 0)
 		skb_condense(skb);
@@ -867,7 +865,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 		rxrpc_input_ackinfo(call, skb, &info);
 
 	if (first_soft_ack == 0)
-		return rxrpc_proto_abort("AK0", call, 0);
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_zero);
 
 	/* Ignore ACKs unless we are or have just been transmitting. */
 	switch (READ_ONCE(call->state)) {
@@ -882,20 +880,20 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 
 	if (before(hard_ack, call->acks_hard_ack) ||
 	    after(hard_ack, call->tx_top))
-		return rxrpc_proto_abort("AKW", call, 0);
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_outside_window);
 	if (nr_acks > call->tx_top - hard_ack)
-		return rxrpc_proto_abort("AKN", call, 0);
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_sack_overflow);
 
 	if (after(hard_ack, call->acks_hard_ack)) {
 		if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
-			rxrpc_end_tx_phase(call, false, "ETA");
+			rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ack);
 			return;
 		}
 	}
 
 	if (nr_acks > 0) {
 		if (offset > (int)skb->len - nr_acks)
-			return rxrpc_proto_abort("XSA", call, 0);
+			return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_short_sack);
 		rxrpc_input_soft_acks(call, skb->data + offset, first_soft_ack,
 				      nr_acks, &summary);
 	}
@@ -917,7 +915,7 @@ static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
 	struct rxrpc_ack_summary summary = { 0 };
 
 	if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
-		rxrpc_end_tx_phase(call, false, "ETL");
+		rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ackall);
 }
 
 /*
@@ -962,27 +960,23 @@ void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb)
 
 	switch (sp->hdr.type) {
 	case RXRPC_PACKET_TYPE_DATA:
-		rxrpc_input_data(call, skb);
-		break;
+		return rxrpc_input_data(call, skb);
 
 	case RXRPC_PACKET_TYPE_ACK:
-		rxrpc_input_ack(call, skb);
-		break;
+		return rxrpc_input_ack(call, skb);
 
 	case RXRPC_PACKET_TYPE_BUSY:
 		/* Just ignore BUSY packets from the server; the retry and
 		 * lifespan timers will take care of business.  BUSY packets
 		 * from the client don't make sense.
 		 */
-		break;
+		return;
 
 	case RXRPC_PACKET_TYPE_ABORT:
-		rxrpc_input_abort(call, skb);
-		break;
+		return rxrpc_input_abort(call, skb);
 
 	case RXRPC_PACKET_TYPE_ACKALL:
-		rxrpc_input_ackall(call, skb);
-		break;
+		return rxrpc_input_ackall(call, skb);
 
 	default:
 		break;
@@ -1004,7 +998,8 @@ void rxrpc_implicit_end_call(struct rxrpc_call *call, struct sk_buff *skb)
 	case RXRPC_CALL_COMPLETE:
 		break;
 	default:
-		rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN);
+		rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ESHUTDOWN,
+				 rxrpc_eproto_improper_term);
 		trace_rxrpc_improper_term(call);
 		break;
 	}