Merge tag 'rxrpc-fixes-20171124' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: Fixes and improvements

Here's a set of patches that fix and improve some stuff in the AF_RXRPC
protocol:

The patches are:

 (1) Unlock mutex returned by rxrpc_accept_call().

 (2) Don't set connection upgrade by default.

 (3) Differentiate the call->user_mutex used by the kernel from that used
     by userspace calling sendmsg() to avoid lockdep warnings.

 (4) Delay terminal ACK transmission to a work queue so that it can be
     replaced by the next call if there is one.

 (5) Split the call parameters from the connection parameters so that more
     call-specific parameters can be passed through.

 (6) Fix the call timeouts to work the same as for other RxRPC/AFS
     implementations.

 (7) Don't transmit DELAY ACKs immediately, but instead delay them slightly
     so that can be discarded or can represent more packets.

 (8) Use RTT to calculate certain protocol timeouts.

 (9) Add a timeout to detect lost ACK/DATA packets.

(10) Add a keepalive function so that we ping the peer if we haven't
     transmitted for a short while, thereby keeping intervening firewall
     routes open.

(11) Make service endpoints expire like they're supposed to so that the UDP
     port can be reused.

(12) Fix connection expiry timers to make cleanup happen in a more timely
     fashion.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 130 insertions, 99 deletions

diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 3574508baf9a..bda952ffe6a6 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -22,80 +22,6 @@
 #include "ar-internal.h"
 
 /*
- * Set the timer
- */
-void __rxrpc_set_timer(struct rxrpc_call *call, enum rxrpc_timer_trace why,
-		       ktime_t now)
-{
-	unsigned long t_j, now_j = jiffies;
-	ktime_t t;
-	bool queue = false;
-
-	if (call->state < RXRPC_CALL_COMPLETE) {
-		t = call->expire_at;
-		if (!ktime_after(t, now)) {
-			trace_rxrpc_timer(call, why, now, now_j);
-			queue = true;
-			goto out;
-		}
-
-		if (!ktime_after(call->resend_at, now)) {
-			call->resend_at = call->expire_at;
-			if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
-				queue = true;
-		} else if (ktime_before(call->resend_at, t)) {
-			t = call->resend_at;
-		}
-
-		if (!ktime_after(call->ack_at, now)) {
-			call->ack_at = call->expire_at;
-			if (!test_and_set_bit(RXRPC_CALL_EV_ACK, &call->events))
-				queue = true;
-		} else if (ktime_before(call->ack_at, t)) {
-			t = call->ack_at;
-		}
-
-		if (!ktime_after(call->ping_at, now)) {
-			call->ping_at = call->expire_at;
-			if (!test_and_set_bit(RXRPC_CALL_EV_PING, &call->events))
-				queue = true;
-		} else if (ktime_before(call->ping_at, t)) {
-			t = call->ping_at;
-		}
-
-		t_j = nsecs_to_jiffies(ktime_to_ns(ktime_sub(t, now)));
-		t_j += jiffies;
-
-		/* We have to make sure that the calculated jiffies value falls
-		 * at or after the nsec value, or we may loop ceaselessly
-		 * because the timer times out, but we haven't reached the nsec
-		 * timeout yet.
-		 */
-		t_j++;
-
-		if (call->timer.expires != t_j || !timer_pending(&call->timer)) {
-			mod_timer(&call->timer, t_j);
-			trace_rxrpc_timer(call, why, now, now_j);
-		}
-	}
-
-out:
-	if (queue)
-		rxrpc_queue_call(call);
-}
-
-/*
- * Set the timer
- */
-void rxrpc_set_timer(struct rxrpc_call *call, enum rxrpc_timer_trace why,
-		     ktime_t now)
-{
-	read_lock_bh(&call->state_lock);
-	__rxrpc_set_timer(call, why, now);
-	read_unlock_bh(&call->state_lock);
-}
-
-/*
  * Propose a PING ACK be sent.
  */
 static void rxrpc_propose_ping(struct rxrpc_call *call,
@@ -106,12 +32,13 @@ static void rxrpc_propose_ping(struct rxrpc_call *call,
 		    !test_and_set_bit(RXRPC_CALL_EV_PING, &call->events))
 			rxrpc_queue_call(call);
 	} else {
-		ktime_t now = ktime_get_real();
-		ktime_t ping_at = ktime_add_ms(now, rxrpc_idle_ack_delay);
+		unsigned long now = jiffies;
+		unsigned long ping_at = now + rxrpc_idle_ack_delay;
 
-		if (ktime_before(ping_at, call->ping_at)) {
-			call->ping_at = ping_at;
-			rxrpc_set_timer(call, rxrpc_timer_set_for_ping, now);
+		if (time_before(ping_at, call->ping_at)) {
+			WRITE_ONCE(call->ping_at, ping_at);
+			rxrpc_reduce_call_timer(call, ping_at, now,
+						rxrpc_timer_set_for_ping);
 		}
 	}
 }
@@ -125,8 +52,7 @@ static void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
 				enum rxrpc_propose_ack_trace why)
 {
 	enum rxrpc_propose_ack_outcome outcome = rxrpc_propose_ack_use;
-	unsigned int expiry = rxrpc_soft_ack_delay;
-	ktime_t now, ack_at;
+	unsigned long expiry = rxrpc_soft_ack_delay;
 	s8 prior = rxrpc_ack_priority[ack_reason];
 
 	/* Pings are handled specially because we don't want to accidentally
@@ -190,11 +116,18 @@ static void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
 		    background)
 			rxrpc_queue_call(call);
 	} else {
-		now = ktime_get_real();
-		ack_at = ktime_add_ms(now, expiry);
-		if (ktime_before(ack_at, call->ack_at)) {
-			call->ack_at = ack_at;
-			rxrpc_set_timer(call, rxrpc_timer_set_for_ack, now);
+		unsigned long now = jiffies, ack_at;
+
+		if (call->peer->rtt_usage > 0)
+			ack_at = nsecs_to_jiffies(call->peer->rtt);
+		else
+			ack_at = expiry;
+
+		ack_at = jiffies + expiry;
+		if (time_before(ack_at, call->ack_at)) {
+			WRITE_ONCE(call->ack_at, ack_at);
+			rxrpc_reduce_call_timer(call, ack_at, now,
+						rxrpc_timer_set_for_ack);
 		}
 	}
 
@@ -227,18 +160,28 @@ static void rxrpc_congestion_timeout(struct rxrpc_call *call)
 /*
  * Perform retransmission of NAK'd and unack'd packets.
  */
-static void rxrpc_resend(struct rxrpc_call *call, ktime_t now)
+static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j)
 {
 	struct rxrpc_skb_priv *sp;
 	struct sk_buff *skb;
+	unsigned long resend_at;
 	rxrpc_seq_t cursor, seq, top;
-	ktime_t max_age, oldest, ack_ts;
+	ktime_t now, max_age, oldest, ack_ts, timeout, min_timeo;
 	int ix;
 	u8 annotation, anno_type, retrans = 0, unacked = 0;
 
 	_enter("{%d,%d}", call->tx_hard_ack, call->tx_top);
 
-	max_age = ktime_sub_ms(now, rxrpc_resend_timeout);
+	if (call->peer->rtt_usage > 1)
+		timeout = ns_to_ktime(call->peer->rtt * 3 / 2);
+	else
+		timeout = ms_to_ktime(rxrpc_resend_timeout);
+	min_timeo = ns_to_ktime((1000000000 / HZ) * 4);
+	if (ktime_before(timeout, min_timeo))
+		timeout = min_timeo;
+
+	now = ktime_get_real();
+	max_age = ktime_sub(now, timeout);
 
 	spin_lock_bh(&call->lock);
 
@@ -282,7 +225,9 @@ static void rxrpc_resend(struct rxrpc_call *call, ktime_t now)
 				       ktime_to_ns(ktime_sub(skb->tstamp, max_age)));
 	}
 
-	call->resend_at = ktime_add_ms(oldest, rxrpc_resend_timeout);
+	resend_at = nsecs_to_jiffies(ktime_to_ns(ktime_sub(oldest, now)));
+	resend_at += jiffies + rxrpc_resend_timeout;
+	WRITE_ONCE(call->resend_at, resend_at);
 
 	if (unacked)
 		rxrpc_congestion_timeout(call);
@@ -292,14 +237,15 @@ static void rxrpc_resend(struct rxrpc_call *call, ktime_t now)
 	 * retransmitting data.
 	 */
 	if (!retrans) {
-		rxrpc_set_timer(call, rxrpc_timer_set_for_resend, now);
+		rxrpc_reduce_call_timer(call, resend_at, now,
+					rxrpc_timer_set_for_resend);
 		spin_unlock_bh(&call->lock);
 		ack_ts = ktime_sub(now, call->acks_latest_ts);
 		if (ktime_to_ns(ack_ts) < call->peer->rtt)
 			goto out;
 		rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, false,
 				  rxrpc_propose_ack_ping_for_lost_ack);
-		rxrpc_send_ack_packet(call, true);
+		rxrpc_send_ack_packet(call, true, NULL);
 		goto out;
 	}
 
@@ -364,7 +310,8 @@ void rxrpc_process_call(struct work_struct *work)
 {
 	struct rxrpc_call *call =
 		container_of(work, struct rxrpc_call, processor);
-	ktime_t now;
+	rxrpc_serial_t *send_ack;
+	unsigned long now, next, t;
 
 	rxrpc_see_call(call);
 
@@ -384,22 +331,89 @@ recheck_state:
 		goto out_put;
 	}
 
-	now = ktime_get_real();
-	if (ktime_before(call->expire_at, now)) {
+	/* Work out if any timeouts tripped */
+	now = jiffies;
+	t = READ_ONCE(call->expect_rx_by);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_normal, now);
+		set_bit(RXRPC_CALL_EV_EXPIRED, &call->events);
+	}
+
+	t = READ_ONCE(call->expect_req_by);
+	if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST &&
+	    time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_idle, now);
+		set_bit(RXRPC_CALL_EV_EXPIRED, &call->events);
+	}
+
+	t = READ_ONCE(call->expect_term_by);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_hard, now);
+		set_bit(RXRPC_CALL_EV_EXPIRED, &call->events);
+	}
+
+	t = READ_ONCE(call->ack_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_ack, now);
+		cmpxchg(&call->ack_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_ACK, &call->events);
+	}
+
+	t = READ_ONCE(call->ack_lost_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_lost_ack, now);
+		cmpxchg(&call->ack_lost_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_ACK_LOST, &call->events);
+	}
+
+	t = READ_ONCE(call->keepalive_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_keepalive, now);
+		cmpxchg(&call->keepalive_at, t, now + MAX_JIFFY_OFFSET);
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, true,
+				  rxrpc_propose_ack_ping_for_keepalive);
+		set_bit(RXRPC_CALL_EV_PING, &call->events);
+	}
+
+	t = READ_ONCE(call->ping_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_ping, now);
+		cmpxchg(&call->ping_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_PING, &call->events);
+	}
+
+	t = READ_ONCE(call->resend_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_resend, now);
+		cmpxchg(&call->resend_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_RESEND, &call->events);
+	}
+
+	/* Process events */
+	if (test_and_clear_bit(RXRPC_CALL_EV_EXPIRED, &call->events)) {
 		rxrpc_abort_call("EXP", call, 0, RX_USER_ABORT, -ETIME);
 		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 		goto recheck_state;
 	}
 
-	if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events)) {
+	send_ack = NULL;
+	if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events)) {
+		call->acks_lost_top = call->tx_top;
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, false,
+				  rxrpc_propose_ack_ping_for_lost_ack);
+		send_ack = &call->acks_lost_ping;
+	}
+
+	if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events) ||
+	    send_ack) {
 		if (call->ackr_reason) {
-			rxrpc_send_ack_packet(call, false);
+			rxrpc_send_ack_packet(call, false, send_ack);
 			goto recheck_state;
 		}
 	}
 
 	if (test_and_clear_bit(RXRPC_CALL_EV_PING, &call->events)) {
-		rxrpc_send_ack_packet(call, true);
+		rxrpc_send_ack_packet(call, true, NULL);
 		goto recheck_state;
 	}
 
@@ -408,7 +422,24 @@ recheck_state:
 		goto recheck_state;
 	}
 
-	rxrpc_set_timer(call, rxrpc_timer_set_for_resend, now);
+	/* Make sure the timer is restarted */
+	next = call->expect_rx_by;
+
+#define set(T) { t = READ_ONCE(T); if (time_before(t, next)) next = t; }
+	
+	set(call->expect_req_by);
+	set(call->expect_term_by);
+	set(call->ack_at);
+	set(call->ack_lost_at);
+	set(call->resend_at);
+	set(call->keepalive_at);
+	set(call->ping_at);
+
+	now = jiffies;
+	if (time_after_eq(now, next))
+		goto recheck_state;
+
+	rxrpc_reduce_call_timer(call, next, now, rxrpc_timer_restart);
 
 	/* other events may have been raised since we started checking */
 	if (call->events && call->state < RXRPC_CALL_COMPLETE) {