mon: check is_shutdown() in timer callbacks

introduce a helper class: C_MonContext, and initialize all timer events
using it, to ensure that they do check is_shutdown() before doing their
work.

Fixes: http://tracker.ceph.com/issues/19825
Signed-off-by: Kefu Chai <kchai@redhat.com>

1 files changed, 25 insertions, 60 deletions

diff --git a/src/mon/Paxos.cc b/src/mon/Paxos.cc
index 2e905ac8fb7..8ba73118e0f 100644
--- a/src/mon/Paxos.cc
+++ b/src/mon/Paxos.cc
@@ -37,61 +37,6 @@ static ostream& _prefix(std::ostream *_dout, Monitor *mon, const string& name,
 		<< ") ";
 }
 
-class Paxos::C_CollectTimeout : public Context {
-  Paxos *paxos;
-public:
-  explicit C_CollectTimeout(Paxos *p) : paxos(p) {}
-  void finish(int r) override {
-    if (r == -ECANCELED)
-      return;
-    paxos->collect_timeout();
-  }
-};
-
-class Paxos::C_AcceptTimeout : public Context {
-  Paxos *paxos;
-public:
-  explicit C_AcceptTimeout(Paxos *p) : paxos(p) {}
-  void finish(int r) override {
-    if (r == -ECANCELED)
-      return;
-    paxos->accept_timeout();
-  }
-};
-
-class Paxos::C_LeaseAckTimeout : public Context {
-  Paxos *paxos;
-public:
-  explicit C_LeaseAckTimeout(Paxos *p) : paxos(p) {}
-  void finish(int r) override {
-    if (r == -ECANCELED)
-      return;
-    paxos->lease_ack_timeout();
-  }
-};
-
-class Paxos::C_LeaseTimeout : public Context {
-  Paxos *paxos;
-public:
-  explicit C_LeaseTimeout(Paxos *p) : paxos(p) {}
-  void finish(int r) override {
-    if (r == -ECANCELED)
-      return;
-    paxos->lease_timeout();
-  }
-};
-
-class Paxos::C_LeaseRenew : public Context {
-  Paxos *paxos;
-public:
-  explicit C_LeaseRenew(Paxos *p) : paxos(p) {}
-  void finish(int r) override {
-    if (r == -ECANCELED)
-      return;
-    paxos->lease_renew_timeout();
-  }
-};
-
 class Paxos::C_Trimmed : public Context {
   Paxos *paxos;
 public:
@@ -249,7 +194,11 @@ void Paxos::collect(version_t oldpn)
   }
 
   // set timeout event
-  collect_timeout_event = new C_CollectTimeout(this);
+  collect_timeout_event = new C_MonContext(mon, [this](int r) {
+	if (r == -ECANCELED)
+	  return;
+	collect_timeout();
+    });
   mon->timer.add_event_after(g_conf->mon_accept_timeout_factor *
 			     g_conf->mon_lease,
 			     collect_timeout_event);
@@ -737,7 +686,11 @@ void Paxos::begin(bufferlist& v)
   }
 
   // set timeout event
-  accept_timeout_event = new C_AcceptTimeout(this);
+  accept_timeout_event = new C_MonContext(mon, [this](int r) {
+      if (r == -ECANCELED)
+	return;
+      accept_timeout();
+    });
   mon->timer.add_event_after(g_conf->mon_accept_timeout_factor *
 			     g_conf->mon_lease,
 			     accept_timeout_event);
@@ -1023,14 +976,22 @@ void Paxos::extend_lease()
   // set timeout event.
   //  if old timeout is still in place, leave it.
   if (!lease_ack_timeout_event) {
-    lease_ack_timeout_event = new C_LeaseAckTimeout(this);
+    lease_ack_timeout_event = new C_MonContext(mon, [this](int r) {
+	if (r == -ECANCELED)
+	  return;
+	lease_ack_timeout();
+      });
     mon->timer.add_event_after(g_conf->mon_lease_ack_timeout_factor *
 			       g_conf->mon_lease,
 			       lease_ack_timeout_event);
   }
 
   // set renew event
-  lease_renew_event = new C_LeaseRenew(this);
+  lease_renew_event = new C_MonContext(mon, [this](int r) {
+      if (r == -ECANCELED)
+	return;
+      lease_renew_timeout();
+    });
   utime_t at = lease_expire;
   at -= g_conf->mon_lease;
   at += g_conf->mon_lease_renew_interval_factor * g_conf->mon_lease;
@@ -1213,7 +1174,11 @@ void Paxos::reset_lease_timeout()
   dout(20) << "reset_lease_timeout - setting timeout event" << dendl;
   if (lease_timeout_event)
     mon->timer.cancel_event(lease_timeout_event);
-  lease_timeout_event = new C_LeaseTimeout(this);
+  lease_timeout_event = new C_MonContext(mon, [this](int r) {
+      if (r == -ECANCELED)
+	return;
+      lease_timeout();
+    });
   mon->timer.add_event_after(g_conf->mon_lease_ack_timeout_factor *
 			     g_conf->mon_lease,
 			     lease_timeout_event);