rxrpc: Add stats procfile and DATA packet stats

Add a procfile, /proc/net/rxrpc/stats, to display some statistics about
what rxrpc has been doing.  Writing a blank line to the stats file will
clear the increment-only counters.  Allocated resource counters don't get
cleared.

Add some counters to count various things about DATA packets, including the
number created, transmitted and retransmitted and the number received, the
number of ACK-requests markings and the number of jumbo packets received.

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

7 files changed, 78 insertions, 0 deletions

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 6c93a2fa96283f..ed406a5f939b1c 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -93,6 +93,14 @@ struct rxrpc_net {
 	struct list_head	peer_keepalive_new;
 	struct timer_list	peer_keepalive_timer;
 	struct work_struct	peer_keepalive_work;
+
+	atomic_t		stat_tx_data;
+	atomic_t		stat_tx_data_retrans;
+	atomic_t		stat_tx_data_send;
+	atomic_t		stat_tx_data_send_frag;
+	atomic_t		stat_rx_data;
+	atomic_t		stat_rx_data_reqack;
+	atomic_t		stat_rx_data_jumbo;
 };
 
 /*
@@ -1093,6 +1101,15 @@ void rxrpc_free_skb(struct sk_buff *, enum rxrpc_skb_trace);
 void rxrpc_purge_queue(struct sk_buff_head *);
 
 /*
+ * stats.c
+ */
+int rxrpc_stats_show(struct seq_file *seq, void *v);
+int rxrpc_stats_clear(struct file *file, char *buf, size_t size);
+
+#define rxrpc_inc_stat(rxnet, s) atomic_inc(&(rxnet)->s)
+#define rxrpc_dec_stat(rxnet, s) atomic_dec(&(rxnet)->s)
+
+/*
  * sysctl.c
  */
 #ifdef CONFIG_SYSCTL
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 2a93e7b5fbd051..c5b3ae1fe80b6d 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -261,6 +261,7 @@ static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j)
 		rxrpc_get_skb(skb, rxrpc_skb_got);
 		spin_unlock_bh(&call->lock);
 
+		rxrpc_inc_stat(call->rxnet, stat_tx_data_retrans);
 		if (rxrpc_send_data_packet(call, skb, true) < 0) {
 			rxrpc_free_skb(skb, rxrpc_skb_freed);
 			return;
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 4ba678f0c384d1..e7586d5ea2c39e 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -443,6 +443,12 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 		}
 	}
 
+	rxrpc_inc_stat(call->rxnet, stat_rx_data);
+	if (sp->hdr.flags & RXRPC_REQUEST_ACK)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
+	if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
+
 	spin_lock(&call->input_lock);
 
 	/* Received data implicitly ACKs all of the request packets we sent
diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c
index bb4c25d6df64c6..84242c0e467c12 100644
--- a/net/rxrpc/net_ns.c
+++ b/net/rxrpc/net_ns.c
@@ -101,6 +101,8 @@ static __net_init int rxrpc_init_net(struct net *net)
 	proc_create_net("locals", 0444, rxnet->proc_net,
 			&rxrpc_local_seq_ops,
 			sizeof(struct seq_net_private));
+	proc_create_net_single_write("stats", S_IFREG | 0644, rxnet->proc_net,
+				     rxrpc_stats_show, rxrpc_stats_clear, NULL);
 	return 0;
 
 err_proc:
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 2922c10bd50006..8fddad2f63fc1b 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -462,6 +462,7 @@ dont_set_request_ack:
 	 *   - in which case, we'll have processed the ICMP error
 	 *     message and update the peer record
 	 */
+	rxrpc_inc_stat(call->rxnet, stat_tx_data_send);
 	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 	conn->params.peer->last_tx_at = ktime_get_seconds();
 
@@ -537,6 +538,7 @@ send_fragmentable:
 	case AF_INET:
 		ip_sock_set_mtu_discover(conn->params.local->socket->sk,
 				IP_PMTUDISC_DONT);
+		rxrpc_inc_stat(call->rxnet, stat_tx_data_send_frag);
 		ret = kernel_sendmsg(conn->params.local->socket, &msg,
 				     iov, 2, len);
 		conn->params.peer->last_tx_at = ktime_get_seconds();
diff --git a/net/rxrpc/proc.c b/net/rxrpc/proc.c
index 245418943e01cc..1027444119326a 100644
--- a/net/rxrpc/proc.c
+++ b/net/rxrpc/proc.c
@@ -397,3 +397,51 @@ const struct seq_operations rxrpc_local_seq_ops = {
 	.stop   = rxrpc_local_seq_stop,
 	.show   = rxrpc_local_seq_show,
 };
+
+/*
+ * Display stats in /proc/net/rxrpc/stats
+ */
+int rxrpc_stats_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_single_net(seq));
+
+	seq_printf(seq,
+		   "Data     : send=%u sendf=%u\n",
+		   atomic_read(&rxnet->stat_tx_data_send),
+		   atomic_read(&rxnet->stat_tx_data_send_frag));
+	seq_printf(seq,
+		   "Data-Tx  : nr=%u retrans=%u\n",
+		   atomic_read(&rxnet->stat_tx_data),
+		   atomic_read(&rxnet->stat_tx_data_retrans));
+	seq_printf(seq,
+		   "Data-Rx  : nr=%u reqack=%u jumbo=%u\n",
+		   atomic_read(&rxnet->stat_rx_data),
+		   atomic_read(&rxnet->stat_rx_data_reqack),
+		   atomic_read(&rxnet->stat_rx_data_jumbo));
+	seq_printf(seq,
+		   "Buffers  : txb=%u rxb=%u\n",
+		   atomic_read(&rxrpc_n_tx_skbs),
+		   atomic_read(&rxrpc_n_rx_skbs));
+	return 0;
+}
+
+/*
+ * Clear stats if /proc/net/rxrpc/stats is written to.
+ */
+int rxrpc_stats_clear(struct file *file, char *buf, size_t size)
+{
+	struct seq_file *m = file->private_data;
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_single_net(m));
+
+	if (size > 1 || (size == 1 && buf[0] != '\n'))
+		return -EINVAL;
+
+	atomic_set(&rxnet->stat_tx_data, 0);
+	atomic_set(&rxnet->stat_tx_data_retrans, 0);
+	atomic_set(&rxnet->stat_tx_data_send, 0);
+	atomic_set(&rxnet->stat_tx_data_send_frag, 0);
+	atomic_set(&rxnet->stat_rx_data, 0);
+	atomic_set(&rxnet->stat_rx_data_reqack, 0);
+	atomic_set(&rxnet->stat_rx_data_jumbo, 0);
+	return size;
+}
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 3c3a626459debb..ad6f2cd089164e 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -200,6 +200,8 @@ static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 
 	_net("queue skb %p [%d]", skb, seq);
 
+	rxrpc_inc_stat(call->rxnet, stat_tx_data);
+
 	ASSERTCMP(seq, ==, call->tx_top + 1);
 
 	if (last)