rxrpc: Fix loss of PING RESPONSE ACK production due to PING ACKs
Separate the output of PING ACKs from the output of other sorts of ACK so
that if we receive a PING ACK and schedule transmission of a PING RESPONSE
ACK, the response doesn't get cancelled by a PING ACK we happen to be
scheduling transmission of at the same time.
If a PING RESPONSE gets lost, the other side might just sit there waiting
for it and refuse to proceed otherwise.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 2dae877..a12cea0 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -38,7 +38,8 @@
static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
struct rxrpc_ack_buffer *pkt,
rxrpc_seq_t *_hard_ack,
- rxrpc_seq_t *_top)
+ rxrpc_seq_t *_top,
+ u8 reason)
{
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top, seq;
@@ -58,10 +59,10 @@
pkt->ack.firstPacket = htonl(hard_ack + 1);
pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
pkt->ack.serial = htonl(serial);
- pkt->ack.reason = call->ackr_reason;
+ pkt->ack.reason = reason;
pkt->ack.nAcks = top - hard_ack;
- if (pkt->ack.reason == RXRPC_ACK_PING)
+ if (reason == RXRPC_ACK_PING)
pkt->whdr.flags |= RXRPC_REQUEST_ACK;
if (after(top, hard_ack)) {
@@ -93,7 +94,7 @@
/*
* Send an ACK call packet.
*/
-int rxrpc_send_ack_packet(struct rxrpc_call *call)
+int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
{
struct rxrpc_connection *conn = NULL;
struct rxrpc_ack_buffer *pkt;
@@ -102,8 +103,8 @@
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top;
size_t len, n;
- bool ping = false;
int ret;
+ u8 reason;
spin_lock_bh(&call->lock);
if (call->conn)
@@ -136,14 +137,18 @@
pkt->whdr.serviceId = htons(call->service_id);
spin_lock_bh(&call->lock);
- if (!call->ackr_reason) {
- spin_unlock_bh(&call->lock);
- ret = 0;
- goto out;
+ if (ping) {
+ reason = RXRPC_ACK_PING;
+ } else {
+ reason = call->ackr_reason;
+ if (!call->ackr_reason) {
+ spin_unlock_bh(&call->lock);
+ ret = 0;
+ goto out;
+ }
+ call->ackr_reason = 0;
}
- ping = (call->ackr_reason == RXRPC_ACK_PING);
- n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
- call->ackr_reason = 0;
+ n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top, reason);
spin_unlock_bh(&call->lock);
@@ -161,7 +166,7 @@
pkt->ack.reason, pkt->ack.nAcks);
if (ping) {
- call->ackr_ping = serial;
+ call->ping_serial = serial;
smp_wmb();
/* We need to stick a time in before we send the packet in case
* the reply gets back before kernel_sendmsg() completes - but
@@ -170,18 +175,19 @@
* the packet transmission is more likely to happen towards the
* end of the kernel_sendmsg() call.
*/
- call->ackr_ping_time = ktime_get_real();
+ call->ping_time = ktime_get_real();
set_bit(RXRPC_CALL_PINGING, &call->flags);
trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
}
ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
if (ping)
- call->ackr_ping_time = ktime_get_real();
+ call->ping_time = ktime_get_real();
if (call->state < RXRPC_CALL_COMPLETE) {
if (ret < 0) {
- clear_bit(RXRPC_CALL_PINGING, &call->flags);
+ if (ping)
+ clear_bit(RXRPC_CALL_PINGING, &call->flags);
rxrpc_propose_ACK(call, pkt->ack.reason,
ntohs(pkt->ack.maxSkew),
ntohl(pkt->ack.serial),