1 files changed, 107 insertions, 0 deletions
diff --git a/src/librbd/operation/TrimRequest.h b/src/librbd/operation/TrimRequest.h
new file mode 100644
index 00000000..8526046c
--- /dev/null
+++ b/src/librbd/operation/TrimRequest.h
@@ -0,0 +1,107 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+#ifndef CEPH_LIBRBD_OPERATION_TRIM_REQUEST_H
+#define CEPH_LIBRBD_OPERATION_TRIM_REQUEST_H
+
+#include "librbd/AsyncRequest.h"
+
+namespace librbd
+{
+
+class ImageCtx;
+class ProgressContext;
+
+namespace operation {
+
+template <typename ImageCtxT = ImageCtx>
+class TrimRequest : public AsyncRequest<ImageCtxT>
+{
+public:
+  static TrimRequest *create(ImageCtxT &image_ctx, Context *on_finish,
+                             uint64_t original_size, uint64_t new_size,
+                             ProgressContext &prog_ctx) {
+    return new TrimRequest(image_ctx, on_finish, original_size, new_size,
+                           prog_ctx);
+  }
+
+  TrimRequest(ImageCtxT &image_ctx, Context *on_finish,
+	      uint64_t original_size, uint64_t new_size,
+	      ProgressContext &prog_ctx);
+
+  void send() override;
+
+protected:
+  /**
+   * Trim goes through the following state machine to remove whole objects,
+   * clean partially trimmed objects, and update the object map:
+   *
+   * @verbatim
+   *
+   *     <start>  . . . . . . . . . . . . . . . . .
+   *        |                                     .
+   *        v (skip if not needed)                .
+   * STATE_PRE_TRIM                               .
+   *        |                                     .
+   *        v (skip if not needed)                .
+   * STATE_COPYUP_OBJECTS                         .
+   *        |                                     .
+   *        v (skip if not needed)                .
+   * STATE_REMOVE_OBJECTS                         .
+   *        |                                     .
+   *        v (skip if not needed)                .
+   * STATE_POST_TRIM                              .
+   *        |                                     .
+   *        v (skip if not needed)                .
+   * STATE_CLEAN_BOUNDARY                         .
+   *        |                                     .
+   *        v                                     .
+   * STATE_FINISHED < . . . . . . . . . . . . . . .
+   *        |
+   *        v
+   *    <finish>
+   *
+   * The _COPYUP_OBJECTS state is skipped if there is no parent overlap
+   * within the new image size and the image does not have any snapshots.
+   * The _PRE_TRIM/_POST_TRIM states are skipped if the object map
+   * isn't enabled. The _REMOVE_OBJECTS state is skipped if no whole objects
+   * are removed.  The _CLEAN_BOUNDARY state is skipped if no boundary
+   * objects are cleaned.  The state machine will immediately transition
+   * to _FINISHED state if there are no bytes to trim.
+   */
+
+  enum State {
+    STATE_PRE_TRIM,
+    STATE_COPYUP_OBJECTS,
+    STATE_REMOVE_OBJECTS,
+    STATE_POST_TRIM,
+    STATE_CLEAN_BOUNDARY,
+    STATE_FINISHED
+  };
+
+  bool should_complete(int r) override;
+
+  State m_state = STATE_PRE_TRIM;
+
+private:
+  uint64_t m_delete_start;
+  uint64_t m_delete_start_min = 0;
+  uint64_t m_num_objects;
+  uint64_t m_delete_off;
+  uint64_t m_new_size;
+  ProgressContext &m_prog_ctx;
+
+  void send_pre_trim();
+  void send_copyup_objects();
+  void send_remove_objects();
+  void send_post_trim();
+
+  void send_clean_boundary();
+  void send_finish(int r);
+};
+
+} // namespace operation
+} // namespace librbd
+
+extern template class librbd::operation::TrimRequest<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_OPERATION_TRIM_REQUEST_H