rxrpc: Move error processing into the local endpoint I/O thread

Move the processing of error packets into the local endpoint I/O thread,
leaving the handover from UDP to merely transfer them into the local
endpoint queue.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

net/rxrpc/ar-internal.h

@@ -37,6 +37,7 @@ struct rxrpc_txbuf;
  */
 enum rxrpc_skb_mark {
 	RXRPC_SKB_MARK_PACKET,		/* Received packet */
+	RXRPC_SKB_MARK_ERROR,		/* Error notification */
 	RXRPC_SKB_MARK_REJECT_BUSY,	/* Reject with BUSY */
 	RXRPC_SKB_MARK_REJECT_ABORT,	/* Reject with ABORT (code in skb->priority) */
 };
@@ -959,6 +960,7 @@ void rxrpc_input_implicit_end_call(struct rxrpc_sock *, struct rxrpc_connection
  * io_thread.c
  */
 int rxrpc_encap_rcv(struct sock *, struct sk_buff *);
+void rxrpc_error_report(struct sock *);
 int rxrpc_io_thread(void *data);
 static inline void rxrpc_wake_up_io_thread(struct rxrpc_local *local)
 {
@@ -1063,7 +1065,7 @@ void rxrpc_send_keepalive(struct rxrpc_peer *);
 /*
  * peer_event.c
  */
-void rxrpc_error_report(struct sock *);
+void rxrpc_input_error(struct rxrpc_local *, struct sk_buff *);
 void rxrpc_peer_keepalive_worker(struct work_struct *);
 
 /*

net/rxrpc/io_thread.c

@@ -37,6 +37,31 @@ int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb)
 	return 0;
 }
 
+/*
+ * Handle an error received on the local endpoint.
+ */
+void rxrpc_error_report(struct sock *sk)
+{
+	struct rxrpc_local *local;
+	struct sk_buff *skb;
+
+	rcu_read_lock();
+	local = rcu_dereference_sk_user_data(sk);
+	if (unlikely(!local)) {
+		rcu_read_unlock();
+		return;
+	}
+
+	while ((skb = skb_dequeue(&sk->sk_error_queue))) {
+		skb->mark = RXRPC_SKB_MARK_ERROR;
+		rxrpc_new_skb(skb, rxrpc_skb_new_error_report);
+		skb_queue_tail(&local->rx_queue, skb);
+	}
+
+	rxrpc_wake_up_io_thread(local);
+	rcu_read_unlock();
+}
+
 /*
  * post connection-level events to the connection
  * - this includes challenges, responses, some aborts and call terminal packet
@@ -405,6 +430,10 @@ int rxrpc_io_thread(void *data)
 				rxrpc_input_packet(local, skb);
 				rcu_read_unlock();
 				break;
+			case RXRPC_SKB_MARK_ERROR:
+				rxrpc_input_error(local, skb);
+				rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
+				break;
 			default:
 				WARN_ON_ONCE(1);
 				rxrpc_free_skb(skb, rxrpc_skb_put_unknown);

net/rxrpc/peer_event.c

@@ -131,51 +131,26 @@ static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu)
 /*
  * Handle an error received on the local endpoint.
  */
-void rxrpc_error_report(struct sock *sk)
+void rxrpc_input_error(struct rxrpc_local *local, struct sk_buff *skb)
 {
-	struct sock_exterr_skb *serr;
+	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
 	struct sockaddr_rxrpc srx;
-	struct rxrpc_local *local;
 	struct rxrpc_peer *peer = NULL;
-	struct sk_buff *skb;
 
-	rcu_read_lock();
-	local = rcu_dereference_sk_user_data(sk);
-	if (unlikely(!local)) {
-		rcu_read_unlock();
-		return;
-	}
-	_enter("%p{%d}", sk, local->debug_id);
+	_enter("L=%x", local->debug_id);
 
-	/* Clear the outstanding error value on the socket so that it doesn't
-	 * cause kernel_sendmsg() to return it later.
-	 */
-	sock_error(sk);
-
-	skb = sock_dequeue_err_skb(sk);
-	if (!skb) {
-		rcu_read_unlock();
-		_leave("UDP socket errqueue empty");
-		return;
-	}
-	rxrpc_new_skb(skb, rxrpc_skb_new_error_report);
-	serr = SKB_EXT_ERR(skb);
 	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
 		_leave("UDP empty message");
-		rcu_read_unlock();
-		rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
 		return;
 	}
 
+	rcu_read_lock();
 	peer = rxrpc_lookup_peer_local_rcu(local, skb, &srx);
 	if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input_error))
 		peer = NULL;
-	if (!peer) {
-		rcu_read_unlock();
-		rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
-		_leave(" [no peer]");
+	rcu_read_unlock();
+	if (!peer)
 		return;
-	}
 
 	trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
 
@@ -188,11 +163,7 @@ void rxrpc_error_report(struct sock *sk)
 
 	rxrpc_store_error(peer, serr);
 out:
-	rcu_read_unlock();
-	rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
 	rxrpc_put_peer(peer, rxrpc_peer_put_input_error);
-
-	_leave("");
 }
 
 /*