ceph/src/librbd/operation/TrimRequest.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 #ifndef CEPH_LIBRBD_OPERATION_TRIM_REQUEST_H
   4 #define CEPH_LIBRBD_OPERATION_TRIM_REQUEST_H
   5
   6 #include "librbd/AsyncRequest.h"
   7
   8 namespace librbd
   9 {
  10
  11 class ImageCtx;
  12 class ProgressContext;
  13
  14 namespace operation {
  15
  16 template <typename ImageCtxT = ImageCtx>
  17 class TrimRequest : public AsyncRequest<ImageCtxT>
  18 {
  19 public:
  20   static TrimRequest *create(ImageCtxT &image_ctx, Context *on_finish,
  21                              uint64_t original_size, uint64_t new_size,
  22                              ProgressContext &prog_ctx) {
  23     return new TrimRequest(image_ctx, on_finish, original_size, new_size,
  24                            prog_ctx);
  25   }
  26
  27   TrimRequest(ImageCtxT &image_ctx, Context *on_finish,
  28               uint64_t original_size, uint64_t new_size,
  29               ProgressContext &prog_ctx);
  30
  31   void send() override;
  32
  33 protected:
  34   /**
  35    * Trim goes through the following state machine to remove whole objects,
  36    * clean partially trimmed objects, and update the object map:
  37    *
  38    * @verbatim
  39    *
  40    *     <start>  . . . . . . . . . . . . . . . . .
  41    *        |                                     .
  42    *        v (skip if not needed)                .
  43    * STATE_PRE_TRIM                               .
  44    *        |                                     .
  45    *        v (skip if not needed)                .
  46    * STATE_COPYUP_OBJECTS                         .
  47    *        |                                     .
  48    *        v (skip if not needed)                .
  49    * STATE_REMOVE_OBJECTS                         .
  50    *        |                                     .
  51    *        v (skip if not needed)                .
  52    * STATE_POST_TRIM                              .
  53    *        |                                     .
  54    *        v (skip if not needed)                .
  55    * STATE_CLEAN_BOUNDARY                         .
  56    *        |                                     .
  57    *        v                                     .
  58    * STATE_FINISHED < . . . . . . . . . . . . . . .
  59    *        |
  60    *        v
  61    *    <finish>
  62    *
  63    * The _COPYUP_OBJECTS state is skipped if there is no parent overlap
  64    * within the new image size and the image does not have any snapshots.
  65    * The _PRE_TRIM/_POST_TRIM states are skipped if the object map
  66    * isn't enabled. The _REMOVE_OBJECTS state is skipped if no whole objects
  67    * are removed.  The _CLEAN_BOUNDARY state is skipped if no boundary
  68    * objects are cleaned.  The state machine will immediately transition
  69    * to _FINISHED state if there are no bytes to trim.
  70    */
  71
  72   enum State {
  73     STATE_PRE_TRIM,
  74     STATE_COPYUP_OBJECTS,
  75     STATE_REMOVE_OBJECTS,
  76     STATE_POST_TRIM,
  77     STATE_CLEAN_BOUNDARY,
  78     STATE_FINISHED
  79   };
  80
  81   bool should_complete(int r) override;
  82
  83   State m_state = STATE_PRE_TRIM;
  84
  85 private:
  86   uint64_t m_delete_start;
  87   uint64_t m_delete_start_min = 0;
  88   uint64_t m_num_objects;
  89   uint64_t m_delete_off;
  90   uint64_t m_new_size;
  91   ProgressContext &m_prog_ctx;
  92
  93   void send_pre_trim();
  94   void send_copyup_objects();
  95   void send_remove_objects();
  96   void send_post_trim();
  97
  98   void send_clean_boundary();
  99   void send_finish(int r);
 100 };
 101
 102 } // namespace operation
 103 } // namespace librbd
 104
 105 extern template class librbd::operation::TrimRequest<librbd::ImageCtx>;
 106
 107 #endif // CEPH_LIBRBD_OPERATION_TRIM_REQUEST_H