Merge pull request ceph#27513 from ddiss/librados_silence_unused_vars

librbd: silence -Wunused-variable warnings

Reviewed-by: Jason Dillaman <[email protected]>

src/librbd/librbd.cc

@@ -719,11 +719,13 @@ namespace librbd {
                io_ctx.get_id());
 
     int r = librbd::api::Image<>::list_images(io_ctx, images);
+#ifdef WITH_LTTNG
     if (r >= 0) {
       for (auto& it : *images) {
         tracepoint(librbd, list_entry, it.name.c_str());
       }
     }
+#endif
     tracepoint(librbd, list_exit, r, r);
     return r;
   }
@@ -1796,13 +1798,14 @@ namespace librbd {
                ictx->snap_name.c_str(), ictx->read_only);
 
     int r = librbd::api::Image<>::list_children(ictx, images);
+#ifdef WITH_LTTNG
     if (r >= 0) {
       for (auto& it : *images) {
         tracepoint(librbd, list_children_entry, it.pool_name.c_str(),
                    it.image_name.c_str());
       }
     }
-
+#endif
     tracepoint(librbd, list_children_exit, r);
     return r;
   }
@@ -2589,11 +2592,13 @@ namespace librbd {
     ImageCtx *ictx = (ImageCtx *)ctx;
     tracepoint(librbd, list_watchers_enter, ictx, ictx->name.c_str(), ictx->snap_name.c_str(), ictx->read_only);
     int r = librbd::list_watchers(ictx, watchers);
+#ifdef WITH_LTTNG
     if (r >= 0) {
       for (auto &watcher : watchers) {
 	tracepoint(librbd, list_watchers_entry, watcher.addr.c_str(), watcher.id, watcher.cookie);
       }
     }
+#endif
     tracepoint(librbd, list_watchers_exit, r, watchers.size());
     return r;
   }