rxrpc: Fix the call timer handling

The call timer's concept of a call timeout (of which there are three) that
is inactive is that it is the timeout has the same expiration time as the
call expiration timeout (the expiration timer is never inactive).  However,
I'm not resetting the timeouts when they expire, leading to repeated
processing of expired timeouts when other timeout events occur.

Fix this by:

 (1) Move the timer expiry detection into rxrpc_set_timer() inside the
     locked section.  This means that if a timeout is set that will expire
     immediately, we deal with it immediately.

 (2) If a timeout is at or before now then it has expired.  When an expiry
     is detected, an event is raised, the timeout is automatically
     inactivated and the event processor is queued.

 (3) If a timeout is at or after the expiry timeout then it is inactive.
     Inactive timeouts do not contribute to the timer setting.

 (4) The call timer callback can now just call rxrpc_set_timer() to handle
     things.

 (5) The call processor work function now checks the event flags rather
     than checking the timeouts directly.

Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 9ff3bb3ffb4157656b1e18b3f6fadf5552f94fc9..4f00476630b93587cc83a1894fbe09337c0e2712 100644 (file)
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -29,6 +29,7 @@ void rxrpc_set_timer(struct rxrpc_call *call, enum rxrpc_timer_trace why,
 {
        unsigned long t_j, now_j = jiffies;
        ktime_t t;
+       bool queue = false;
 
        read_lock_bh(&call->state_lock);
 
@@ -37,13 +38,21 @@ void rxrpc_set_timer(struct rxrpc_call *call, enum rxrpc_timer_trace why,
                if (!ktime_after(t, now))
                        goto out;
 
-               if (ktime_after(call->resend_at, now) &&
-                   ktime_before(call->resend_at, t))
+               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) &&
-                   ktime_before(call->ack_at, t))
+               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;
+               }
 
                t_j = nsecs_to_jiffies(ktime_to_ns(ktime_sub(t, now)));
                t_j += jiffies;
@@ -59,6 +68,9 @@ void rxrpc_set_timer(struct rxrpc_call *call, enum rxrpc_timer_trace why,
                        mod_timer(&call->timer, t_j);
                        trace_rxrpc_timer(call, why, now, now_j);
                }
+
+               if (queue)
+                       rxrpc_queue_call(call);
        }
 
 out:
@@ -332,8 +344,7 @@ recheck_state:
                goto recheck_state;
        }
 
-       if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events) ||
-           ktime_before(call->ack_at, now)) {
+       if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events)) {
                call->ack_at = call->expire_at;
                if (call->ackr_reason) {
                        rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
@@ -341,8 +352,7 @@ recheck_state:
                }
        }
 
-       if (test_and_clear_bit(RXRPC_CALL_EV_RESEND, &call->events) ||
-           ktime_before(call->resend_at, now)) {
+       if (test_and_clear_bit(RXRPC_CALL_EV_RESEND, &call->events)) {
                rxrpc_resend(call, now);
                goto recheck_state;
        }

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 456ab752d473ff590399e0f1428621d6ae03e2a6..364b42dc3dce5360f79e8a26b2d5829361ba20aa 100644 (file)
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -71,11 +71,8 @@ static void rxrpc_call_timer_expired(unsigned long _call)
 
        _enter("%d", call->debug_id);
 
-       if (call->state < RXRPC_CALL_COMPLETE) {
-               trace_rxrpc_timer(call, rxrpc_timer_expired,
-                                 ktime_get_real(), jiffies);
-               rxrpc_queue_call(call);
-       }
+       if (call->state < RXRPC_CALL_COMPLETE)
+               rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real());
 }
 
 /*