doc: Add usage comment to librbd::RBD::AioCompletion

Signed-off-by: Adam Crume <adamcrume@gmail.com>

diff --git a/src/include/rbd/librbd.hpp b/src/include/rbd/librbd.hpp
index 7107f584825326cbb9e9849e3b7066e9f0fc8271..f85e090e76526cc97a934f04037a91e11a28ad90 100644 (file)
--- a/src/include/rbd/librbd.hpp
+++ b/src/include/rbd/librbd.hpp
@@ -60,6 +60,9 @@ public:
   RBD();
   ~RBD();
 
+  // This must be dynamically allocated with new, and
+  // must be released with release().
+  // Do not use delete.
   struct AioCompletion {
     void *pc;
     AioCompletion(void *cb_arg, callback_t complete_cb);