xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

rxrpc: Fix loss of PING RESPONSE ACK production due to PING ACKs

Browse Source 
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>
This commit is contained in:
David Howells
2016-10-06 08:11:49 +01:00
parent 26cb02aa6d
commit a5af7e1fc6
8 changed files with 82 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
net/rxrpc/output.c
View File

@@ -38,7 +38,8 @@ struct rxrpc_abort_buffer {
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 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
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 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
/*
* 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 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call)
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 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call)
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 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call)
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 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call)
* 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),