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, 36 insertions, 57 deletions

diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index 98e49646ca1d..3c8f83dacb2b 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -72,76 +72,55 @@ struct rxrpc_connection *rxrpc_alloc_connection(struct rxrpc_net *rxnet,
  *
  * The caller must be holding the RCU read lock.
  */
-struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
-						   struct sockaddr_rxrpc *srx,
-						   struct sk_buff *skb,
-						   struct rxrpc_peer **_peer)
+struct rxrpc_connection *rxrpc_find_client_connection_rcu(struct rxrpc_local *local,
+							  struct sockaddr_rxrpc *srx,
+							  struct sk_buff *skb)
 {
 	struct rxrpc_connection *conn;
-	struct rxrpc_conn_proto k;
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	struct rxrpc_peer *peer;
 
 	_enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
 
-	k.epoch	= sp->hdr.epoch;
-	k.cid	= sp->hdr.cid & RXRPC_CIDMASK;
-
-	if (rxrpc_to_server(sp)) {
-		/* We need to look up service connections by the full protocol
-		 * parameter set.  We look up the peer first as an intermediate
-		 * step and then the connection from the peer's tree.
-		 */
-		peer = rxrpc_lookup_peer_rcu(local, srx);
-		if (!peer)
-			goto not_found;
-		*_peer = peer;
-		conn = rxrpc_find_service_conn_rcu(peer, skb);
-		if (!conn || refcount_read(&conn->ref) == 0)
-			goto not_found;
-		_leave(" = %p", conn);
-		return conn;
-	} else {
-		/* Look up client connections by connection ID alone as their
-		 * IDs are unique for this machine.
-		 */
-		conn = idr_find(&rxrpc_client_conn_ids, sp->hdr.cid >> RXRPC_CIDSHIFT);
-		if (!conn || refcount_read(&conn->ref) == 0) {
-			_debug("no conn");
-			goto not_found;
-		}
+	/* Look up client connections by connection ID alone as their IDs are
+	 * unique for this machine.
+	 */
+	conn = idr_find(&rxrpc_client_conn_ids, sp->hdr.cid >> RXRPC_CIDSHIFT);
+	if (!conn || refcount_read(&conn->ref) == 0) {
+		_debug("no conn");
+		goto not_found;
+	}
 
-		if (conn->proto.epoch != k.epoch ||
-		    conn->local != local)
+	if (conn->proto.epoch != sp->hdr.epoch ||
+	    conn->local != local)
+		goto not_found;
+
+	peer = conn->peer;
+	switch (srx->transport.family) {
+	case AF_INET:
+		if (peer->srx.transport.sin.sin_port !=
+		    srx->transport.sin.sin_port ||
+		    peer->srx.transport.sin.sin_addr.s_addr !=
+		    srx->transport.sin.sin_addr.s_addr)
 			goto not_found;
-
-		peer = conn->peer;
-		switch (srx->transport.family) {
-		case AF_INET:
-			if (peer->srx.transport.sin.sin_port !=
-			    srx->transport.sin.sin_port ||
-			    peer->srx.transport.sin.sin_addr.s_addr !=
-			    srx->transport.sin.sin_addr.s_addr)
-				goto not_found;
-			break;
+		break;
 #ifdef CONFIG_AF_RXRPC_IPV6
-		case AF_INET6:
-			if (peer->srx.transport.sin6.sin6_port !=
-			    srx->transport.sin6.sin6_port ||
-			    memcmp(&peer->srx.transport.sin6.sin6_addr,
-				   &srx->transport.sin6.sin6_addr,
-				   sizeof(struct in6_addr)) != 0)
-				goto not_found;
-			break;
+	case AF_INET6:
+		if (peer->srx.transport.sin6.sin6_port !=
+		    srx->transport.sin6.sin6_port ||
+		    memcmp(&peer->srx.transport.sin6.sin6_addr,
+			   &srx->transport.sin6.sin6_addr,
+			   sizeof(struct in6_addr)) != 0)
+			goto not_found;
+		break;
 #endif
-		default:
-			BUG();
-		}
-
-		_leave(" = %p", conn);
-		return conn;
+	default:
+		BUG();
 	}
 
+	_leave(" = %p", conn);
+	return conn;
+
 not_found:
 	_leave(" = NULL");
 	return NULL;