src/ceph/src/librbd/operation/SnapshotRollbackRequest.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #ifndef CEPH_LIBRBD_OPERATION_SNAPSHOT_ROLLBACK_REQUEST_H
   5 #define CEPH_LIBRBD_OPERATION_SNAPSHOT_ROLLBACK_REQUEST_H
   6
   7 #include "librbd/operation/Request.h"
   8 #include "librbd/ImageCtx.h"
   9 #include "librbd/internal.h"
  10 #include "librbd/journal/Types.h"
  11 #include <string>
  12
  13 class Context;
  14
  15 namespace librbd {
  16
  17 class ProgressContext;
  18
  19 namespace operation {
  20
  21 template <typename ImageCtxT = ImageCtx>
  22 class SnapshotRollbackRequest : public Request<ImageCtxT> {
  23 public:
  24   /**
  25    * Snap Rollback goes through the following state machine:
  26    *
  27    * @verbatim
  28    *
  29    * <start> ---------\
  30    *                  |
  31    *                  v
  32    *            STATE_BLOCK_WRITES
  33    *                  |
  34    *                  v
  35    *            STATE_RESIZE_IMAGE (skip if resize not
  36    *                  |             required)
  37    *                  v
  38    *            STATE_ROLLBACK_OBJECT_MAP (skip if object
  39    *                  |                    map disabled)
  40    *                  v
  41    *            STATE_ROLLBACK_OBJECTS
  42    *                  |
  43    *                  v
  44    *            STATE_REFRESH_OBJECT_MAP  (skip if object
  45    *                  |                    map disabled)
  46    *                  v
  47    *            STATE_INVALIDATE_CACHE (skip if cache
  48    *                  |                 disabled)
  49    *                  v
  50    *              <finish>
  51    *
  52    * @endverbatim
  53    *
  54    * The _RESIZE_IMAGE state is skipped if the image doesn't need to be resized.
  55    * The _ROLLBACK_OBJECT_MAP state is skipped if the object map isn't enabled.
  56    * The _INVALIDATE_CACHE state is skipped if the cache isn't enabled.
  57    */
  58
  59   SnapshotRollbackRequest(ImageCtxT &image_ctx, Context *on_finish,
  60                           const cls::rbd::SnapshotNamespace &snap_namespace,
  61                           const std::string &snap_name,
  62                           uint64_t snap_id,
  63                           uint64_t snap_size, ProgressContext &prog_ctx);
  64   ~SnapshotRollbackRequest() override;
  65
  66 protected:
  67   void send_op() override;
  68   bool should_complete(int r) override {
  69     return true;
  70   }
  71
  72   journal::Event create_event(uint64_t op_tid) const override {
  73     return journal::SnapRollbackEvent(op_tid, m_snap_namespace, m_snap_name);
  74   }
  75
  76 private:
  77   cls::rbd::SnapshotNamespace m_snap_namespace;
  78   std::string m_snap_name;
  79   uint64_t m_snap_id;
  80   uint64_t m_snap_size;
  81   ProgressContext &m_prog_ctx;
  82
  83   NoOpProgressContext m_no_op_prog_ctx;
  84
  85   bool m_blocking_writes = false;
  86   decltype(ImageCtxT::object_map) m_object_map;
  87
  88   void send_block_writes();
  89   Context *handle_block_writes(int *result);
  90
  91   void send_resize_image();
  92   Context *handle_resize_image(int *result);
  93
  94   void send_rollback_object_map();
  95   Context *handle_rollback_object_map(int *result);
  96
  97   void send_rollback_objects();
  98   Context *handle_rollback_objects(int *result);
  99
 100   Context *send_refresh_object_map();
 101   Context *handle_refresh_object_map(int *result);
 102
 103   Context *send_invalidate_cache();
 104   Context *handle_invalidate_cache(int *result);
 105
 106   void apply();
 107 };
 108
 109 } // namespace operation
 110 } // namespace librbd
 111
 112 extern template class librbd::operation::SnapshotRollbackRequest<librbd::ImageCtx>;
 113
 114 #endif // CEPH_LIBRBD_OPERATION_SNAPSHOT_ROLLBACK_REQUEST_H