1 files changed, 135 insertions, 0 deletions
diff --git a/src/librbd/io/CopyupRequest.h b/src/librbd/io/CopyupRequest.h
new file mode 100644
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+++ b/src/librbd/io/CopyupRequest.h
@@ -0,0 +1,135 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_IO_COPYUP_REQUEST_H
+#define CEPH_LIBRBD_IO_COPYUP_REQUEST_H
+
+#include "include/int_types.h"
+#include "include/rados/librados.hpp"
+#include "include/buffer.h"
+#include "common/Mutex.h"
+#include "common/zipkin_trace.h"
+#include "librbd/io/AsyncOperation.h"
+#include "librbd/io/Types.h"
+
+#include <string>
+#include <vector>
+
+namespace ZTracer { struct Trace; }
+
+namespace librbd {
+
+struct ImageCtx;
+
+namespace io {
+
+template <typename I> class AbstractObjectWriteRequest;
+
+template <typename ImageCtxT = librbd::ImageCtx>
+class CopyupRequest {
+public:
+  static CopyupRequest* create(ImageCtxT *ictx, const std::string &oid,
+                               uint64_t objectno, Extents &&image_extents,
+                               const ZTracer::Trace &parent_trace) {
+    return new CopyupRequest(ictx, oid, objectno, std::move(image_extents),
+                             parent_trace);
+  }
+
+  CopyupRequest(ImageCtxT *ictx, const std::string &oid, uint64_t objectno,
+                Extents &&image_extents, const ZTracer::Trace &parent_trace);
+  ~CopyupRequest();
+
+  void append_request(AbstractObjectWriteRequest<ImageCtxT> *req);
+
+  void send();
+
+private:
+  /**
+   * Copyup requests go through the following state machine to read from the
+   * parent image, update the object map, and copyup the object:
+   *
+   *
+   * @verbatim
+   *
+   *              <start>
+   *                 |
+   *      /---------/ \---------\
+   *      |                     |
+   *      v                     v
+   *  READ_FROM_PARENT      DEEP_COPY
+   *      |                     |
+   *      \---------\ /---------/
+   *                 |
+   *                 v (skip if not needed)
+   *         UPDATE_OBJECT_MAPS
+   *                 |
+   *                 v (skip if not needed)
+   *              COPYUP
+   *                 |
+   *                 v
+   *              <finish>
+   *
+   * @endverbatim
+   *
+   * The OBJECT_MAP state is skipped if the object map isn't enabled or if
+   * an object map update isn't required. The COPYUP state is skipped if
+   * no data was read from the parent *and* there are no additional ops.
+   */
+
+  typedef std::vector<AbstractObjectWriteRequest<ImageCtxT> *> WriteRequests;
+
+  ImageCtxT *m_image_ctx;
+  std::string m_oid;
+  uint64_t m_object_no;
+  Extents m_image_extents;
+  ZTracer::Trace m_trace;
+
+  bool m_flatten = false;
+  bool m_copyup_required = true;
+  bool m_copyup_is_zero = true;
+
+  ceph::bufferlist m_copyup_data;
+
+  AsyncOperation m_async_op;
+
+  std::vector<uint64_t> m_snap_ids;
+  bool m_first_snap_is_clean = false;
+
+  Mutex m_lock;
+  WriteRequests m_pending_requests;
+  unsigned m_pending_copyups = 0;
+
+  WriteRequests m_restart_requests;
+  bool m_append_request_permitted = true;
+
+  void read_from_parent();
+  void handle_read_from_parent(int r);
+
+  void deep_copy();
+  void handle_deep_copy(int r);
+
+  void update_object_maps();
+  void handle_update_object_maps(int r);
+
+  void copyup();
+  void handle_copyup(int r);
+
+  void finish(int r);
+  void complete_requests(bool override_restart_retval, int r);
+
+  void disable_append_requests();
+  void remove_from_list();
+
+  bool is_copyup_required();
+  bool is_update_object_map_required(int r);
+  bool is_deep_copy() const;
+
+  void compute_deep_copy_snap_ids();
+};
+
+} // namespace io
+} // namespace librbd
+
+extern template class librbd::io::CopyupRequest<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_IO_COPYUP_REQUEST_H