librbd: don't flush image_watcher if it's nullptr

Signed-off-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
ceph · Sep 9, 2016 · 9a37724 · 9a37724
1 parent 5962a0d
commit 9a37724
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/src/librbd/ExclusiveLock.cc b/src/librbd/ExclusiveLock.cc
@@ -711,8 +711,11 @@ void ExclusiveLock<I>::handle_shutdown(int r) {
 
   m_image_ctx.aio_work_queue->clear_require_lock_on_read();
   m_image_ctx.aio_work_queue->unblock_writes();
-  m_image_ctx.image_watcher->flush(util::create_context_callback<
-    ExclusiveLock<I>, &ExclusiveLock<I>::complete_shutdown>(this));
+  if (m_image_ctx.image_watcher == nullptr)
+    complete_shutdown(r);
+  else
+    m_image_ctx.image_watcher->flush(util::create_context_callback<
+      ExclusiveLock<I>, &ExclusiveLock<I>::complete_shutdown>(this));
 }
 
 template <typename I>