ceph/src/librbd/mirror/snapshot/PromoteRequest.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_MIRROR_SNAPSHOT_PROMOTE_REQUEST_H
   5 #define CEPH_LIBRBD_MIRROR_SNAPSHOT_PROMOTE_REQUEST_H
   6
   7 #include "include/buffer.h"
   8 #include "include/rbd/librbd.hpp"
   9 #include "librbd/internal.h"
  10
  11 #include <string>
  12 #include <set>
  13
  14 class SafeTimer;
  15 struct Context;
  16
  17 namespace librbd {
  18
  19 struct ImageCtx;
  20
  21 namespace mirror {
  22 namespace snapshot {
  23
  24 template <typename ImageCtxT = librbd::ImageCtx>
  25 class PromoteRequest {
  26 public:
  27   static PromoteRequest *create(ImageCtxT *image_ctx,
  28                                 const std::string& global_image_id,
  29                                 Context *on_finish) {
  30     return new PromoteRequest(image_ctx, global_image_id, on_finish);
  31   }
  32
  33   PromoteRequest(ImageCtxT *image_ctx, const std::string& global_image_id,
  34                  Context *on_finish)
  35     : m_image_ctx(image_ctx), m_global_image_id(global_image_id),
  36       m_on_finish(on_finish) {
  37   }
  38
  39   void send();
  40
  41 private:
  42   /**
  43    * @verbatim
  44    *
  45    * <start>
  46    *    |
  47    *    |          (can promote)
  48    *    |\----------------------------------------\
  49    *    |                                         |
  50    *    |                                         |
  51    *    v (skip if not needed)                    |
  52    * CREATE_ORPHAN_SNAPSHOT                       |
  53    *    |                                         |
  54    *    |     /-- UNREGISTER_UPDATE_WATCHER <-\   |
  55    *    v     v                               |   |
  56    * LIST_WATCHERS ----> WAIT_UPDATE_NOTIFY --/   |
  57    *    |                                         |
  58    *    | (no watchers)                           |
  59    *    v                                         |
  60    * ACQUIRE_EXCLUSIVE_LOCK                       |
  61    *    |  (skip if not needed)                   |
  62    *    v                                         |
  63    * ROLLBACK                                     |
  64    *    |                                         |
  65    *    v                                         |
  66    * CREATE_PROMOTE_SNAPSHOT <--------------------/
  67    *    |
  68    *    v
  69    * DISABLE_NON_PRIMARY_FEATURE
  70    *    |
  71    *    v
  72    * RELEASE_EXCLUSIVE_LOCK (skip if not needed)
  73    *    |
  74    *    v
  75    * <finish>
  76    *
  77    * @endverbatim
  78    */
  79
  80   ImageCtxT *m_image_ctx;
  81   std::string m_global_image_id;
  82   Context *m_on_finish;
  83
  84   uint64_t m_rollback_snap_id = CEPH_NOSNAP;
  85   bool m_lock_acquired = false;
  86   NoOpProgressContext m_progress_ctx;
  87
  88   class UpdateWatchCtx : public librbd::UpdateWatchCtx {
  89   public:
  90     UpdateWatchCtx(PromoteRequest *promote_request)
  91       : promote_request(promote_request) {
  92     }
  93
  94     void handle_notify() {
  95       promote_request->handle_update_notify();
  96     }
  97
  98   private:
  99     PromoteRequest *promote_request;
 100
 101   } m_update_watch_ctx = {this};
 102
 103   std::list<obj_watch_t> m_watchers;
 104   uint64_t m_update_watcher_handle = 0;
 105   uint64_t m_scheduler_ticks = 0;
 106   SafeTimer *m_timer = nullptr;
 107   ceph::mutex *m_timer_lock = nullptr;
 108
 109   void refresh_image();
 110   void handle_refresh_image(int r);
 111
 112   void create_orphan_snapshot();
 113   void handle_create_orphan_snapshot(int r);
 114
 115   void list_watchers();
 116   void handle_list_watchers(int r);
 117
 118   void wait_update_notify();
 119   void handle_update_notify();
 120   void scheduler_unregister_update_watcher();
 121
 122   void unregister_update_watcher();
 123   void handle_unregister_update_watcher(int r);
 124
 125   void acquire_exclusive_lock();
 126   void handle_acquire_exclusive_lock(int r);
 127
 128   void rollback();
 129   void handle_rollback(int r);
 130
 131   void create_promote_snapshot();
 132   void handle_create_promote_snapshot(int r);
 133
 134   void disable_non_primary_feature();
 135   void handle_disable_non_primary_feature(int r);
 136
 137   void release_exclusive_lock();
 138   void handle_release_exclusive_lock(int r);
 139
 140   void finish(int r);
 141
 142 };
 143
 144 } // namespace snapshot
 145 } // namespace mirror
 146 } // namespace librbd
 147
 148 extern template class librbd::mirror::snapshot::PromoteRequest<librbd::ImageCtx>;
 149
 150 #endif // CEPH_LIBRBD_MIRROR_SNAPSHOT_PROMOTE_REQUEST_H