[PATCH 4.18 084/150] rxrpc: Carry call state out of locked section in rxrpc_rotate_tx_window()

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit dfe995224693798e554ab4770f6d8a096afc60cd ]

Carry the call state out of the locked section in rxrpc_rotate_tx_window()
rather than sampling it afterwards.  This is only used to select tracepoint
data, but could have changed by the time we do the tracepoint.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/rxrpc/input.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 5e180a3c2d01..fe1cf206d12a 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -278,23 +278,26 @@ static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
 			       const char *abort_why)
 {
+	unsigned int state;
 
 	ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
 
 	write_lock(&call->state_lock);
 
-	switch (call->state) {
+	state = call->state;
+	switch (state) {
 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
 	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
 		if (reply_begun)
-			call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
+			call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
 		else
-			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+			call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 		break;
 
 	case RXRPC_CALL_SERVER_AWAIT_ACK:
 		__rxrpc_call_completed(call);
 		rxrpc_notify_socket(call);
+		state = call->state;
 		break;
 
 	default:
@@ -302,11 +305,10 @@ static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
 	}
 
 	write_unlock(&call->state_lock);
-	if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) {
+	if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
 		trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
-	} else {
+	else
 		trace_rxrpc_transmit(call, rxrpc_transmit_end);
-	}
 	_leave(" = ok");
 	return true;
 
-- 
2.17.1