rxrpc: Make the I/O thread take over the call and local processor work

Move the functions from the call->processor and local->processor work items
into the domain of the I/O thread.

The call event processor, now called from the I/O thread, then takes over
the job of cranking the call state machine, processing incoming packets and
transmitting DATA, ACK and ABORT packets.  In a future patch,
rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it
for later transmission.

The call event processor becomes purely received-skb driven.  It only
transmits things in response to events.  We use "pokes" to queue a dummy
skb to make it do things like start/resume transmitting data.  Timer expiry
also results in pokes.

The connection event processor, becomes similar, though crypto events, such
as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item
to avoid doing crypto in the I/O thread.

The local event processor is removed and VERSION response packets are
generated directly from the packet parser.  Similarly, ABORTs generated in
response to protocol errors will be transmitted immediately rather than
being pushed onto a queue for later transmission.

Changes:
========
ver #2)
 - Fix a couple of introduced lock context imbalances.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

1 files changed, 60 insertions, 0 deletions

diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
index 23a74e35052d..643a56322224 100644
--- a/net/rxrpc/conn_event.c
+++ b/net/rxrpc/conn_event.c
@@ -479,3 +479,63 @@ void rxrpc_process_connection(struct work_struct *work)
 		rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
 	}
 }
+
+/*
+ * post connection-level events to the connection
+ * - this includes challenges, responses, some aborts and call terminal packet
+ *   retransmission.
+ */
+static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
+				      struct sk_buff *skb)
+{
+	_enter("%p,%p", conn, skb);
+
+	rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
+	skb_queue_tail(&conn->rx_queue, skb);
+	rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
+}
+
+/*
+ * Input a connection-level packet.
+ */
+int rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
+		_leave(" = -ECONNABORTED [%u]", conn->state);
+		return -ECONNABORTED;
+	}
+
+	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_DATA:
+	case RXRPC_PACKET_TYPE_ACK:
+		rxrpc_conn_retransmit_call(conn, skb,
+					   sp->hdr.cid & RXRPC_CHANNELMASK);
+		return 0;
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		/* Just ignore BUSY packets for now. */
+		return 0;
+
+	case RXRPC_PACKET_TYPE_ABORT:
+		conn->error = -ECONNABORTED;
+		conn->abort_code = skb->priority;
+		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
+		set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
+		return -ECONNABORTED;
+
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		rxrpc_post_packet_to_conn(conn, skb);
+		return 0;
+
+	default:
+		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+				      tracepoint_string("bad_conn_pkt"));
+		return -EPROTO;
+	}
+}