osdc/Objecter: drop lock to unregister asok hooks

unregister blocks until any running hook has
completed, and that running hook might
be one that takes the objecter lock, so you
can't hold it while unregistering.

Signed-off-by: John Spray <john.spray@redhat.com>

diff --git a/src/osdc/Objecter.cc b/src/osdc/Objecter.cc
index 9ace054ca0c05e854f0a28a64f639773c55cc183..8a6f1e659e0c1e2a89b8c2d5d3ff7cc905db27b5 100644 (file)
--- a/src/osdc/Objecter.cc
+++ b/src/osdc/Objecter.cc
@@ -466,13 +466,6 @@ void Objecter::shutdown()
     tick_event = 0;
   }
 
-  if (m_request_state_hook) {
-    AdminSocket* admin_socket = cct->get_admin_socket();
-    admin_socket->unregister_command("objecter_requests");
-    delete m_request_state_hook;
-    m_request_state_hook = NULL;
-  }
-
   if (logger) {
     cct->get_perfcounters_collection()->remove(logger);
     delete logger;
@@ -481,6 +474,16 @@ void Objecter::shutdown()
 
   // Let go of Objecter write lock so timer thread can shutdown
   wl.unlock();
+
+  // Outside of lock to avoid cycle WRT calls to RequestStateHook
+  // This is safe because we guarantee no concurrent calls to
+  // shutdown() with the ::initialized check at start.
+  if (m_request_state_hook) {
+    AdminSocket* admin_socket = cct->get_admin_socket();
+    admin_socket->unregister_command("objecter_requests");
+    delete m_request_state_hook;
+    m_request_state_hook = NULL;
+  }
 }
 
 void Objecter::_send_linger(LingerOp *info,