Re: [PATCH] rxrpc: split up rxrpc_send_call_packet()

From: David Howells
Date: Fri Sep 30 2016 - 19:53:03 EST

Something like the attached.

David
---
commit 35510eefc29e2757c1ac46218cded2e505093fc2
Author: David Howells <dhowells@xxxxxxxxxx>
Date: Sat Oct 1 00:35:15 2016 +0100

rxrpc: Split rxrpc_send_call_packet()

Split rxrpc_send_data_packet() to separate ACK generation (which is more
complicated) from ABORT generation. This simplifies the code a bit and
avoids the following warning:

In file included from ../net/rxrpc/output.c:20:0:
net/rxrpc/output.c: In function 'rxrpc_send_call_packet':
net/rxrpc/ar-internal.h:1187:27: error: 'top' may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/rxrpc/output.c:103:24: note: 'top' was declared here
net/rxrpc/output.c:225:25: error: 'hard_ack' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index d38dffd78085..100748cb1f00 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -1068,7 +1068,8 @@ extern const s8 rxrpc_ack_priority[];
/*
* output.c
*/
-int rxrpc_send_call_packet(struct rxrpc_call *, u8);
+int rxrpc_send_ack_packet(struct rxrpc_call *);
+int rxrpc_send_abort_packet(struct rxrpc_call *);
int rxrpc_send_data_packet(struct rxrpc_call *, struct sk_buff *, bool);
void rxrpc_reject_packets(struct rxrpc_local *);

diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 3cac231d8405..53981b8f8eb3 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -565,7 +565,7 @@ out_discard:
write_unlock_bh(&call->state_lock);
write_unlock(&rx->call_lock);
if (abort) {
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+ rxrpc_send_abort_packet(call);
rxrpc_release_call(rx, call);
rxrpc_put_call(call, rxrpc_call_put);
}
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 4f00476630b9..e313099860d5 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -253,7 +253,7 @@ static void rxrpc_resend(struct rxrpc_call *call, ktime_t now)
goto out;
rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, false,
rxrpc_propose_ack_ping_for_lost_ack);
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+ rxrpc_send_ack_packet(call);
goto out;
}

@@ -328,7 +328,7 @@ void rxrpc_process_call(struct work_struct *work)

recheck_state:
if (test_and_clear_bit(RXRPC_CALL_EV_ABORT, &call->events)) {
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+ rxrpc_send_abort_packet(call);
goto recheck_state;
}

@@ -347,7 +347,7 @@ recheck_state:
if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events)) {
call->ack_at = call->expire_at;
if (call->ackr_reason) {
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+ rxrpc_send_ack_packet(call);
goto recheck_state;
}
}
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 364b42dc3dce..07094012ac15 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -498,7 +498,7 @@ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
struct rxrpc_call, sock_link);
rxrpc_get_call(call, rxrpc_call_got);
rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET);
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+ rxrpc_send_abort_packet(call);
rxrpc_release_call(rx, call);
rxrpc_put_call(call, rxrpc_call_put);
}
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 0d47db886f6e..2dae877c0876 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -19,24 +19,24 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"

-struct rxrpc_pkt_buffer {
+struct rxrpc_ack_buffer {
struct rxrpc_wire_header whdr;
- union {
- struct {
- struct rxrpc_ackpacket ack;
- u8 acks[255];
- u8 pad[3];
- };
- __be32 abort_code;
- };
+ struct rxrpc_ackpacket ack;
+ u8 acks[255];
+ u8 pad[3];
struct rxrpc_ackinfo ackinfo;
};

+struct rxrpc_abort_buffer {
+ struct rxrpc_wire_header whdr;
+ __be32 abort_code;
+};
+
/*
* Fill out an ACK packet.
*/
static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
- struct rxrpc_pkt_buffer *pkt,
+ struct rxrpc_ack_buffer *pkt,
rxrpc_seq_t *_hard_ack,
rxrpc_seq_t *_top)
{
@@ -91,22 +91,19 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
}

/*
- * Send an ACK or ABORT call packet.
+ * Send an ACK call packet.
*/
-int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
+int rxrpc_send_ack_packet(struct rxrpc_call *call)
{
struct rxrpc_connection *conn = NULL;
- struct rxrpc_pkt_buffer *pkt;
+ struct rxrpc_ack_buffer *pkt;
struct msghdr msg;
struct kvec iov[2];
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top;
size_t len, n;
bool ping = false;
- int ioc, ret;
- u32 abort_code;
-
- _enter("%u,%s", call->debug_id, rxrpc_pkts[type]);
+ int ret;

spin_lock_bh(&call->lock);
if (call->conn)
@@ -131,65 +128,37 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
pkt->whdr.cid = htonl(call->cid);
pkt->whdr.callNumber = htonl(call->call_id);
pkt->whdr.seq = 0;
- pkt->whdr.type = type;
- pkt->whdr.flags = conn->out_clientflag;
+ pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
+ pkt->whdr.flags = RXRPC_SLOW_START_OK | conn->out_clientflag;
pkt->whdr.userStatus = 0;
pkt->whdr.securityIndex = call->security_ix;
pkt->whdr._rsvd = 0;
pkt->whdr.serviceId = htons(call->service_id);

- iov[0].iov_base = pkt;
- iov[0].iov_len = sizeof(pkt->whdr);
- len = sizeof(pkt->whdr);
-
- switch (type) {
- case RXRPC_PACKET_TYPE_ACK:
- spin_lock_bh(&call->lock);
- if (!call->ackr_reason) {
- spin_unlock_bh(&call->lock);
- ret = 0;
- goto out;
- }
- ping = (call->ackr_reason == RXRPC_ACK_PING);
- n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
- call->ackr_reason = 0;
-
+ spin_lock_bh(&call->lock);
+ if (!call->ackr_reason) {
spin_unlock_bh(&call->lock);
-
-
- pkt->whdr.flags |= RXRPC_SLOW_START_OK;
-
- iov[0].iov_len += sizeof(pkt->ack) + n;
- iov[1].iov_base = &pkt->ackinfo;
- iov[1].iov_len = sizeof(pkt->ackinfo);
- len += sizeof(pkt->ack) + n + sizeof(pkt->ackinfo);
- ioc = 2;
- break;
-
- case RXRPC_PACKET_TYPE_ABORT:
- abort_code = call->abort_code;
- pkt->abort_code = htonl(abort_code);
- iov[0].iov_len += sizeof(pkt->abort_code);
- len += sizeof(pkt->abort_code);
- ioc = 1;
- break;
-
- default:
- BUG();
- ret = -ENOANO;
+ ret = 0;
goto out;
}
+ ping = (call->ackr_reason == RXRPC_ACK_PING);
+ n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
+ call->ackr_reason = 0;
+
+ spin_unlock_bh(&call->lock);
+
+ iov[0].iov_base = pkt;
+ iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
+ iov[1].iov_base = &pkt->ackinfo;
+ iov[1].iov_len = sizeof(pkt->ackinfo);
+ len = iov[0].iov_len + iov[1].iov_len;

serial = atomic_inc_return(&conn->serial);
pkt->whdr.serial = htonl(serial);
- switch (type) {
- case RXRPC_PACKET_TYPE_ACK:
- trace_rxrpc_tx_ack(call, serial,
- ntohl(pkt->ack.firstPacket),
- ntohl(pkt->ack.serial),
- pkt->ack.reason, pkt->ack.nAcks);
- break;
- }
+ trace_rxrpc_tx_ack(call, serial,
+ ntohl(pkt->ack.firstPacket),
+ ntohl(pkt->ack.serial),
+ pkt->ack.reason, pkt->ack.nAcks);

if (ping) {
call->ackr_ping = serial;
@@ -205,13 +174,12 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
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, ioc, len);
+
+ ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
if (ping)
call->ackr_ping_time = ktime_get_real();

- if (type == RXRPC_PACKET_TYPE_ACK &&
- call->state < RXRPC_CALL_COMPLETE) {
+ if (call->state < RXRPC_CALL_COMPLETE) {
if (ret < 0) {
clear_bit(RXRPC_CALL_PINGING, &call->flags);
rxrpc_propose_ACK(call, pkt->ack.reason,
@@ -236,6 +204,56 @@ out:
}

/*
+ * Send an ABORT call packet.
+ */
+int rxrpc_send_abort_packet(struct rxrpc_call *call)
+{
+ struct rxrpc_connection *conn = NULL;
+ struct rxrpc_abort_buffer pkt;
+ struct msghdr msg;
+ struct kvec iov[1];
+ rxrpc_serial_t serial;
+ int ret;
+
+ spin_lock_bh(&call->lock);
+ if (call->conn)
+ conn = rxrpc_get_connection_maybe(call->conn);
+ spin_unlock_bh(&call->lock);
+ if (!conn)
+ return -ECONNRESET;
+
+ msg.msg_name = &call->peer->srx.transport;
+ msg.msg_namelen = call->peer->srx.transport_len;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = 0;
+
+ pkt.whdr.epoch = htonl(conn->proto.epoch);
+ pkt.whdr.cid = htonl(call->cid);
+ pkt.whdr.callNumber = htonl(call->call_id);
+ pkt.whdr.seq = 0;
+ pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
+ pkt.whdr.flags = conn->out_clientflag;
+ pkt.whdr.userStatus = 0;
+ pkt.whdr.securityIndex = call->security_ix;
+ pkt.whdr._rsvd = 0;
+ pkt.whdr.serviceId = htons(call->service_id);
+ pkt.abort_code = htonl(call->abort_code);
+
+ iov[0].iov_base = &pkt;
+ iov[0].iov_len = sizeof(pkt);
+
+ serial = atomic_inc_return(&conn->serial);
+ pkt.whdr.serial = htonl(serial);
+
+ ret = kernel_sendmsg(conn->params.local->socket,
+ &msg, iov, 1, sizeof(pkt));
+
+ rxrpc_put_connection(conn);
+ return ret;
+}
+
+/*
* send a packet through the transport endpoint
*/
int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index f05ea0a88076..11723bc1c783 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -143,7 +143,7 @@ static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) {
rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, serial, true, false,
rxrpc_propose_ack_terminal_ack);
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+ rxrpc_send_ack_packet(call);
}

write_lock_bh(&call->state_lock);
@@ -212,7 +212,7 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
true, false,
rxrpc_propose_ack_rotate_rx);
if (call->ackr_reason)
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+ rxrpc_send_ack_packet(call);
}
}

diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 627abed5f999..4374e7b9c7bf 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -381,7 +381,7 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
return 0;

protocol_error:
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+ rxrpc_send_abort_packet(call);
_leave(" = -EPROTO");
return -EPROTO;

@@ -471,7 +471,7 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
return 0;

protocol_error:
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+ rxrpc_send_abort_packet(call);
_leave(" = -EPROTO");
return -EPROTO;

@@ -523,7 +523,7 @@ static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,

if (cksum != expected_cksum) {
rxrpc_abort_call("VCK", call, seq, RXKADSEALEDINCON, EPROTO);
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+ rxrpc_send_abort_packet(call);
_leave(" = -EPROTO [csum failed]");
return -EPROTO;
}
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 3322543d460a..901b28ceeff4 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -197,7 +197,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
do {
/* Check to see if there's a ping ACK to reply to. */
if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+ rxrpc_send_ack_packet(call);

if (!skb) {
size_t size, chunk, max, space;
@@ -514,8 +514,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
} else if (cmd == RXRPC_CMD_SEND_ABORT) {
ret = 0;
if (rxrpc_abort_call("CMD", call, 0, abort_code, ECONNABORTED))
- ret = rxrpc_send_call_packet(call,
- RXRPC_PACKET_TYPE_ABORT);
+ ret = rxrpc_send_abort_packet(call);
} else if (cmd != RXRPC_CMD_SEND_DATA) {
ret = -EINVAL;
} else if (rxrpc_is_client_call(call) &&
@@ -597,7 +596,7 @@ void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
lock_sock(sock->sk);

if (rxrpc_abort_call(why, call, 0, abort_code, error))
- rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+ rxrpc_send_abort_packet(call);

release_sock(sock->sk);
_leave("");