rxrpc: Remove local->defrag_sem

We no longer need local->defrag_sem as all DATA packet transmission is now
done from one thread, so remove it.
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

@@ -284,7 +284,6 @@ struct rxrpc_local {
 	struct task_struct	*io_thread;
 	struct completion	io_thread_ready; /* Indication that the I/O thread started */
 	struct rxrpc_sock	*service;	/* Service(s) listening on this endpoint */
-	struct rw_semaphore	defrag_sem;	/* control re-enablement of IP DF bit */
 #ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
 	struct sk_buff_head	rx_delay_queue;	/* Delay injection queue */
 #endif

net/rxrpc/local_object.c

@@ -108,7 +108,6 @@ static struct rxrpc_local *rxrpc_alloc_local(struct net *net,
 		local->net = net;
 		local->rxnet = rxrpc_net(net);
 		INIT_HLIST_NODE(&local->link);
-		init_rwsem(&local->defrag_sem);
 		init_completion(&local->io_thread_ready);
 #ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
 		skb_queue_head_init(&local->rx_delay_queue);

net/rxrpc/output.c

@@ -409,8 +409,6 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
 	if (txb->len >= call->peer->maxdata)
 		goto send_fragmentable;
 
-	down_read(&conn->local->defrag_sem);
-
 	txb->last_sent = ktime_get_real();
 	if (txb->wire.flags & RXRPC_REQUEST_ACK)
 		rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
@@ -425,7 +423,6 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
 	ret = do_udp_sendmsg(conn->local->socket, &msg, len);
 	conn->peer->last_tx_at = ktime_get_seconds();
 
-	up_read(&conn->local->defrag_sem);
 	if (ret < 0) {
 		rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);
 		rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
@@ -486,8 +483,6 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
 	/* attempt to send this message with fragmentation enabled */
 	_debug("send fragment");
 
-	down_write(&conn->local->defrag_sem);
-
 	txb->last_sent = ktime_get_real();
 	if (txb->wire.flags & RXRPC_REQUEST_ACK)
 		rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
@@ -519,8 +514,6 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
 				      rxrpc_tx_point_call_data_frag);
 	}
 	rxrpc_tx_backoff(call, ret);
-
-	up_write(&conn->local->defrag_sem);
 	goto done;
 }