1 files changed, 122 insertions, 0 deletions
diff --git a/src/librbd/operation/SnapshotRollbackRequest.h b/src/librbd/operation/SnapshotRollbackRequest.h
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+++ b/src/librbd/operation/SnapshotRollbackRequest.h
@@ -0,0 +1,122 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_OPERATION_SNAPSHOT_ROLLBACK_REQUEST_H
+#define CEPH_LIBRBD_OPERATION_SNAPSHOT_ROLLBACK_REQUEST_H
+
+#include "librbd/operation/Request.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/internal.h"
+#include "librbd/journal/Types.h"
+#include <string>
+
+class Context;
+
+namespace librbd {
+
+class ProgressContext;
+
+namespace operation {
+
+template <typename ImageCtxT = ImageCtx>
+class SnapshotRollbackRequest : public Request<ImageCtxT> {
+public:
+  /**
+   * Snap Rollback goes through the following state machine:
+   *
+   * @verbatim
+   *
+   * <start> ---------\
+   *                  |
+   *                  v
+   *            STATE_BLOCK_WRITES
+   *                  |
+   *                  v
+   *            STATE_RESIZE_IMAGE (skip if resize not
+   *                  |             required)
+   *                  v
+   *            STATE_GET_SNAP_OBJECT_MAP (skip if object)
+   *                  |                    map disabled)
+   *                  v
+   *            STATE_ROLLBACK_OBJECT_MAP (skip if object
+   *                  |                    map disabled)
+   *                  v
+   *            STATE_ROLLBACK_OBJECTS
+   *                  |
+   *                  v
+   *            STATE_REFRESH_OBJECT_MAP  (skip if object
+   *                  |                    map disabled)
+   *                  v
+   *            STATE_INVALIDATE_CACHE (skip if cache
+   *                  |                 disabled)
+   *                  v
+   *              <finish>
+   *
+   * @endverbatim
+   *
+   * The _RESIZE_IMAGE state is skipped if the image doesn't need to be resized.
+   * The _ROLLBACK_OBJECT_MAP state is skipped if the object map isn't enabled.
+   * The _INVALIDATE_CACHE state is skipped if the cache isn't enabled.
+   */
+
+  SnapshotRollbackRequest(ImageCtxT &image_ctx, Context *on_finish,
+			  const cls::rbd::SnapshotNamespace &snap_namespace,
+                          const std::string &snap_name,
+			  uint64_t snap_id,
+                          uint64_t snap_size, ProgressContext &prog_ctx);
+  ~SnapshotRollbackRequest() override;
+
+protected:
+  void send_op() override;
+  bool should_complete(int r) override {
+    return true;
+  }
+
+  journal::Event create_event(uint64_t op_tid) const override {
+    return journal::SnapRollbackEvent(op_tid, m_snap_namespace, m_snap_name);
+  }
+
+private:
+  cls::rbd::SnapshotNamespace m_snap_namespace;
+  std::string m_snap_name;
+  uint64_t m_snap_id;
+  uint64_t m_snap_size;
+  uint64_t m_head_num_objects;
+  ProgressContext &m_prog_ctx;
+
+  NoOpProgressContext m_no_op_prog_ctx;
+
+  bool m_blocking_writes = false;
+  decltype(ImageCtxT::object_map) m_object_map;
+  decltype(ImageCtxT::object_map) m_snap_object_map;
+
+  void send_block_writes();
+  Context *handle_block_writes(int *result);
+
+  void send_resize_image();
+  Context *handle_resize_image(int *result);
+
+  void send_get_snap_object_map();
+  Context *handle_get_snap_object_map(int *result);
+
+  void send_rollback_object_map();
+  Context *handle_rollback_object_map(int *result);
+
+  void send_rollback_objects();
+  Context *handle_rollback_objects(int *result);
+
+  Context *send_refresh_object_map();
+  Context *handle_refresh_object_map(int *result);
+
+  Context *send_invalidate_cache();
+  Context *handle_invalidate_cache(int *result);
+
+  void apply();
+};
+
+} // namespace operation
+} // namespace librbd
+
+extern template class librbd::operation::SnapshotRollbackRequest<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_OPERATION_SNAPSHOT_ROLLBACK_REQUEST_H