common: by default, do not assert on leaks in the shared_cache code

Update the standard qa suite cluster configs so that we continue
asserting in our nightlies, but users don't hit this.

Signed-off-by: Greg Farnum <gfarnum@redhat.com>

qa/clusters/extra-client.yaml

@@ -11,4 +11,6 @@ overrides:
   ceph:
     conf:
       osd:
-        osd shutdown pgref assert: true
+        osd shutdown pgref assert: true
+      global:
+        debug_asserts_on_shutdown: true

qa/clusters/fixed-1.yaml

@@ -10,5 +10,7 @@ overrides:
     conf:
       osd:
         osd shutdown pgref assert: true
+      global:
+        debug_asserts_on_shutdown: true
 roles:
 - [mon.a, mgr.x, osd.0, osd.1, osd.2, client.0]

qa/clusters/fixed-2.yaml

@@ -10,3 +10,5 @@ overrides:
     conf:
       osd:
         osd shutdown pgref assert: true
+      global:
+        debug_asserts_on_shutdown: true

qa/clusters/fixed-3-cephfs.yaml

@@ -13,4 +13,6 @@ overrides:
   ceph:
     conf:
       osd:
-        osd shutdown pgref assert: true
+        osd shutdown pgref assert: true
+      global:
+        debug_asserts_on_shutdown: true

qa/clusters/fixed-3.yaml

@@ -11,3 +11,5 @@ overrides:
     conf:
       osd:
         osd shutdown pgref assert: true
+      global:
+        debug_asserts_on_shutdown: true

qa/clusters/fixed-4.yaml

@@ -7,4 +7,6 @@ overrides:
   ceph:
     conf:
       osd:
-        osd shutdown pgref assert: true
+        osd shutdown pgref assert: true
+      global:
+        debug_asserts_on_shutdown: true

src/common/options.cc

@@ -4222,6 +4222,10 @@ std::vector<Option> get_global_options() {
     Option("debug_deliberately_leak_memory", Option::TYPE_BOOL, Option::LEVEL_DEV)
     .set_default(false)
     .set_description(""),
+
+    Option("debug_asserts_on_shutdown", Option::TYPE_BOOL,Option::LEVEL_DEV)
+    .set_default(false)
+    .set_description("Enable certain asserts to check for refcounting bugs on shutdown; see http://tracker.ceph.com/issues/21738"),
   });
 }
 

src/common/shared_cache.hpp

@@ -105,7 +105,9 @@ class SharedLRU {
       lderr(cct) << "leaked refs:\n";
       dump_weak_refs(*_dout);
       *_dout << dendl;
-      assert(weak_refs.empty());
+      if (cct->_conf->get_val<bool>("debug_asserts_on_shutdown")) {
+	assert(weak_refs.empty());
+      }
     }
   }