From dac649753bcb49bcbeafd70b5128349cfc6f6856 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@redhat.com>
Date: Fri, 18 Jan 2019 09:24:34 -0600
Subject: [PATCH] mgr/ActivePyModules: fix RestoreThread calls for
 get('devices')

Fixes 61aa7e2e0230bff49e757c32932d1db4bcad5f67

Fixes: http://tracker.ceph.com/issues/37736
Signed-off-by: Sage Weil <sage@redhat.com>
---
 src/mgr/ActivePyModules.cc | 13 +++++++------
 src/mgr/DaemonState.h      | 11 +++++++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/mgr/ActivePyModules.cc b/src/mgr/ActivePyModules.cc
index 4069b100b67..0e72ad75c8f 100644
--- a/src/mgr/ActivePyModules.cc
+++ b/src/mgr/ActivePyModules.cc
@@ -299,13 +299,14 @@ PyObject *ActivePyModules::get_python(const std::string &what)
     );
     return f.get();
   } else if (what == "devices") {
-    PyEval_RestoreThread(tstate);
     f.open_array_section("devices");
-    daemon_state.with_devices([&f] (const DeviceState& dev) {
-      f.dump_object("device", dev);
-    });
-
-    PyEval_RestoreThread(tstate);
+    daemon_state.with_devices2(
+      [&tstate]() {
+	PyEval_RestoreThread(tstate);
+      },
+      [&f] (const DeviceState& dev) {
+	f.dump_object("device", dev);
+      });
     f.close_section();
     return f.get();
   } else if (what.size() > 7 &&
diff --git a/src/mgr/DaemonState.h b/src/mgr/DaemonState.h
index 692c265027c..680d4a0cc2c 100644
--- a/src/mgr/DaemonState.h
+++ b/src/mgr/DaemonState.h
@@ -334,6 +334,17 @@ public:
     }
   }
 
+  template<typename CallbackInitial, typename Callback, typename...Args>
+  void with_devices2(CallbackInitial&& cbi,  // with lock taken
+		     Callback&& cb,          // for each device
+		     Args&&... args) const {
+    RWLock::RLocker l(lock);
+    cbi();
+    for (auto& i : devices) {
+      std::forward<Callback>(cb)(*i.second, std::forward<Args>(args)...);
+    }
+  }
+
   void list_devids_by_server(const std::string& server,
 			     std::set<std::string> *ls) {
     auto m = get_by_server(server);
-- 
2.39.5