src/ceph/src/librbd/operation/ResizeRequest.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_RESIZE_REQUEST_H
   4 #define CEPH_LIBRBD_OPERATION_RESIZE_REQUEST_H
   5
   6 #include "librbd/operation/Request.h"
   7 #include "include/xlist.h"
   8
   9 namespace librbd
  10 {
  11
  12 class ImageCtx;
  13 class ProgressContext;
  14
  15 namespace operation {
  16
  17 template <typename ImageCtxT = ImageCtx>
  18 class ResizeRequest : public Request<ImageCtxT> {
  19 public:
  20   static ResizeRequest *create(ImageCtxT &image_ctx, Context *on_finish,
  21                                uint64_t new_size, bool allow_shrink,
  22                                ProgressContext &prog_ctx, uint64_t journal_op_tid,
  23                                bool disable_journal) {
  24     return new ResizeRequest(image_ctx, on_finish, new_size, allow_shrink, prog_ctx,
  25                              journal_op_tid, disable_journal);
  26   }
  27
  28   ResizeRequest(ImageCtxT &image_ctx, Context *on_finish, uint64_t new_size,
  29                 bool allow_shrink, ProgressContext &prog_ctx, uint64_t journal_op_tid,
  30                 bool disable_journal);
  31   ~ResizeRequest() override;
  32
  33   inline bool shrinking() const {
  34     return (m_shrink_size_visible && m_new_size < m_original_size);
  35   }
  36
  37   inline uint64_t get_image_size() const {
  38     return m_new_size;
  39   }
  40
  41   void send() override;
  42
  43 protected:
  44   void send_op() override;
  45   bool should_complete(int r) override {
  46     return true;
  47   }
  48   bool can_affect_io() const override {
  49     return true;
  50   }
  51   journal::Event create_event(uint64_t op_tid) const override {
  52     return journal::ResizeEvent(op_tid, m_new_size);
  53   }
  54
  55 private:
  56   /**
  57    * Resize goes through the following state machine to resize the image
  58    * and update the object map:
  59    *
  60    * @verbatim
  61    *
  62    * <start>
  63    *    |
  64    *    v
  65    * STATE_PRE_BLOCK_WRITES
  66    *    |
  67    *    v
  68    * STATE_APPEND_OP_EVENT (skip if journaling
  69    *    |                   disabled)
  70    *    | (unblock writes)
  71    *    |
  72    *    |
  73    *    | (grow)
  74    *    |\--------> STATE_GROW_OBJECT_MAP (skip if object map
  75    *    |                 |                disabled)
  76    *    |                 v
  77    *    |           STATE_POST_BLOCK_WRITES
  78    *    |                 |
  79    *    |                 v
  80    *    |           STATE_UPDATE_HEADER ----------------------------\
  81    *    |                                                           |
  82    *    | (shrink)                                                  |
  83    *    |\--------> STATE_FLUSH_CACHE                               |
  84    *    |                 |                                         |
  85    *    |                 v                                         |
  86    *    |           STATE_INVALIDATE_CACHE                          |
  87    *    |                 |                                         |
  88    *    |                 v                                         |
  89    *    |           STATE_TRIM_IMAGE                                |
  90    *    |                 |                                         |
  91    *    |                 v                                         |
  92    *    |           STATE_POST_BLOCK_WRITES                         |
  93    *    |                 |                                         |
  94    *    |                 v                                         |
  95    *    |           STATE_UPDATE_HEADER                             |
  96    *    |                 |                                         |
  97    *    |                 v                                         |
  98    *    |           STATE_SHRINK_OBJECT_MAP (skip if object map     |
  99    *    |                 |                  disabled)              |
 100    *    |                 | (unblock writes)                        |
 101    *    | (no change)     v                                         |
 102    *    \------------> <finish> <-----------------------------------/
 103    *
 104    * @endverbatim
 105    *
 106    * The _OBJECT_MAP states are skipped if the object map isn't enabled.
 107    * The state machine will immediately transition to _FINISHED if there
 108    * are no objects to trim.
 109    */
 110
 111   uint64_t m_original_size;
 112   uint64_t m_new_size;
 113   bool m_allow_shrink = true;
 114   ProgressContext &m_prog_ctx;
 115   uint64_t m_new_parent_overlap;
 116   bool m_shrink_size_visible = false;
 117   bool m_disable_journal = false;
 118
 119   typename xlist<ResizeRequest<ImageCtxT>*>::item m_xlist_item;
 120
 121   void send_pre_block_writes();
 122   Context *handle_pre_block_writes(int *result);
 123
 124   Context *send_append_op_event();
 125   Context *handle_append_op_event(int *result);
 126
 127   void send_flush_cache();
 128   Context *handle_flush_cache(int *result);
 129
 130   void send_invalidate_cache();
 131   Context *handle_invalidate_cache(int *result);
 132
 133   void send_trim_image();
 134   Context *handle_trim_image(int *result);
 135
 136   Context *send_grow_object_map();
 137   Context *handle_grow_object_map(int *result);
 138
 139   Context *send_shrink_object_map();
 140   Context *handle_shrink_object_map(int *result);
 141
 142   void send_post_block_writes();
 143   Context *handle_post_block_writes(int *result);
 144
 145   void send_update_header();
 146   Context *handle_update_header(int *result);
 147
 148   void compute_parent_overlap();
 149   void update_size_and_overlap();
 150
 151 };
 152
 153 } // namespace operation
 154 } // namespace librbd
 155
 156 extern template class librbd::operation::ResizeRequest<librbd::ImageCtx>;
 157
 158 #endif // CEPH_LIBRBD_OPERATION_RESIZE_REQUEST_H