[PATCH AUTOSEL 4.18 11/27] rxrpc: Carry call state out of locked section in rxrpc_rotate_tx_window()

From: Sasha Levin
Date: Mon Oct 22 2018 - 06:25:47 EST


From: David Howells <dhowells@xxxxxxxxxx>

[ 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