src/ceph/src/librbd/operation/SnapshotUnprotectRequest.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_UNPROTECT_REQUEST_H
   5 #define CEPH_LIBRBD_OPERATION_SNAPSHOT_UNPROTECT_REQUEST_H
   6
   7 #include "librbd/operation/Request.h"
   8 #include <string>
   9
  10 class Context;
  11
  12 namespace librbd {
  13
  14 class ImageCtx;
  15
  16 namespace operation {
  17
  18 template <typename ImageCtxT = ImageCtx>
  19 class SnapshotUnprotectRequest : public Request<ImageCtxT> {
  20 public:
  21   /**
  22    * Snap Unprotect goes through the following state machine:
  23    *
  24    * @verbatim
  25    *
  26    * <start>
  27    *    |
  28    *    v
  29    * STATE_UNPROTECT_SNAP_START
  30    *    |
  31    *    v
  32    * STATE_SCAN_POOL_CHILDREN * * * * > STATE_UNPROTECT_SNAP_ROLLBACK
  33    *    |                                  |
  34    *    v                                  |
  35    * STATE_UNPROTECT_SNAP_FINISH           |
  36    *    |                                  |
  37    *    v                                  |
  38    * <finish> <----------------------------/
  39    *
  40    * @endverbatim
  41    *
  42    * If the unprotect operation needs to abort, the error path is followed
  43    * to rollback the unprotect in-progress status on the image.
  44    */
  45   enum State {
  46     STATE_UNPROTECT_SNAP_START,
  47     STATE_SCAN_POOL_CHILDREN,
  48     STATE_UNPROTECT_SNAP_FINISH,
  49     STATE_UNPROTECT_SNAP_ROLLBACK
  50   };
  51
  52   SnapshotUnprotectRequest(ImageCtxT &image_ctx, Context *on_finish,
  53                            const cls::rbd::SnapshotNamespace &snap_namespace,
  54                            const std::string &snap_name);
  55
  56 protected:
  57   void send_op() override;
  58   bool should_complete(int r) override;
  59
  60   int filter_return_code(int r) const override {
  61     if (m_ret_val < 0) {
  62       return m_ret_val;
  63     }
  64     return 0;
  65   }
  66
  67   journal::Event create_event(uint64_t op_tid) const override {
  68     return journal::SnapUnprotectEvent(op_tid, m_snap_namespace, m_snap_name);
  69   }
  70
  71 private:
  72   cls::rbd::SnapshotNamespace m_snap_namespace;
  73   std::string m_snap_name;
  74   State m_state;
  75
  76   int m_ret_val;
  77   uint64_t m_snap_id;
  78
  79   bool should_complete_error();
  80
  81   void send_unprotect_snap_start();
  82   void send_scan_pool_children();
  83   void send_unprotect_snap_finish();
  84   void send_unprotect_snap_rollback();
  85
  86   int verify_and_send_unprotect_snap_start();
  87 };
  88
  89 } // namespace operation
  90 } // namespace librbd
  91
  92 extern template class librbd::operation::SnapshotUnprotectRequest<librbd::ImageCtx>;
  93
  94 #endif // CEPH_LIBRBD_OPERATION_SNAPSHOT_UNPROTECT_REQUEST_H