From: Mykola Golub <mgolub@suse.com>
Date: Mon, 17 Feb 2020 12:11:59 +0000 (+0000)
Subject: rbd-mirror: don't expect image map is always initialized
X-Git-Tag: v15.1.1~343^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=d916b0948bf8a5a06afb9a63188f6efa2121510d;p=ceph.git

rbd-mirror: don't expect image map is always initialized

in a namespace replayer when handling "instances added/removed"
event. It is possible an event comes when a pool replayer has
already created and initialized a new namespace replayer but has
not acquired leader for it (image_map is not initialized yet).

Also, make sure `m_image_map` is set only after its
initialization is complete.

Fixes: https://tracker.ceph.com/issues/44161
Signed-off-by: Mykola Golub <mgolub@suse.com>
---

diff --git a/src/tools/rbd_mirror/NamespaceReplayer.cc b/src/tools/rbd_mirror/NamespaceReplayer.cc
index 582b875835ee..637e252a9b6f 100644
--- a/src/tools/rbd_mirror/NamespaceReplayer.cc
+++ b/src/tools/rbd_mirror/NamespaceReplayer.cc
@@ -245,7 +245,10 @@ void NamespaceReplayer<I>::handle_instances_added(
 
   std::lock_guard locker{m_lock};
 
-  ceph_assert(m_image_map);
+  if (!m_image_map) {
+    return;
+  }
+
   m_image_map->update_instances_added(instance_ids);
 }
 
@@ -256,7 +259,10 @@ void NamespaceReplayer<I>::handle_instances_removed(
 
   std::lock_guard locker{m_lock};
 
-  ceph_assert(m_image_map);
+  if (!m_image_map) {
+    return;
+  }
+
   m_image_map->update_instances_removed(instance_ids);
 }
 
@@ -567,32 +573,35 @@ template <typename I>
 void NamespaceReplayer<I>::init_image_map(Context *on_finish) {
   dout(10) << dendl;
 
-  std::lock_guard locker{m_lock};
-  ceph_assert(!m_image_map);
-  m_image_map.reset(ImageMap<I>::create(m_local_io_ctx, m_threads,
-                                        m_instance_watcher->get_instance_id(),
-                                        m_image_map_listener));
+  auto image_map = ImageMap<I>::create(m_local_io_ctx, m_threads,
+                                       m_instance_watcher->get_instance_id(),
+                                       m_image_map_listener);
 
   auto ctx = new LambdaContext(
-      [this, on_finish](int r) {
-        handle_init_image_map(r, on_finish);
+      [this, image_map, on_finish](int r) {
+        handle_init_image_map(r, image_map, on_finish);
       });
-  m_image_map->init(create_async_context_callback(
+  image_map->init(create_async_context_callback(
     m_threads->work_queue, ctx));
 }
 
 template <typename I>
-void NamespaceReplayer<I>::handle_init_image_map(int r, Context *on_finish) {
+void NamespaceReplayer<I>::handle_init_image_map(int r, ImageMap<I> *image_map,
+                                                 Context *on_finish) {
   dout(10) << "r=" << r << dendl;
   if (r < 0) {
     derr << "failed to init image map: " << cpp_strerror(r) << dendl;
-    on_finish = new LambdaContext([on_finish, r](int) {
+    on_finish = new LambdaContext([image_map, on_finish, r](int) {
+        delete image_map;
         on_finish->complete(r);
       });
-    shut_down_image_map(on_finish);
+    image_map->shut_down(on_finish);
     return;
   }
 
+  ceph_assert(!m_image_map);
+  m_image_map.reset(image_map);
+
   init_local_pool_watcher(on_finish);
 }
 
diff --git a/src/tools/rbd_mirror/NamespaceReplayer.h b/src/tools/rbd_mirror/NamespaceReplayer.h
index 4fbf4c53bec4..5396106e175b 100644
--- a/src/tools/rbd_mirror/NamespaceReplayer.h
+++ b/src/tools/rbd_mirror/NamespaceReplayer.h
@@ -233,7 +233,8 @@ private:
   void handle_shut_down_local_status_updater(int r);
 
   void init_image_map(Context *on_finish);
-  void handle_init_image_map(int r, Context *on_finish);
+  void handle_init_image_map(int r, ImageMap<ImageCtxT> *image_map,
+                             Context *on_finish);
 
   void init_local_pool_watcher(Context *on_finish);
   void handle_init_local_pool_watcher(int r, Context *on_finish);