ceph/src/librbd/Journal.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_JOURNAL_H
   5 #define CEPH_LIBRBD_JOURNAL_H
   6
   7 #include "include/int_types.h"
   8 #include "include/Context.h"
   9 #include "include/interval_set.h"
  10 #include "include/rados/librados_fwd.hpp"
  11 #include "common/AsyncOpTracker.h"
  12 #include "common/Cond.h"
  13 #include "common/RefCountedObj.h"
  14 #include "journal/Future.h"
  15 #include "journal/JournalMetadataListener.h"
  16 #include "journal/ReplayEntry.h"
  17 #include "journal/ReplayHandler.h"
  18 #include "librbd/Utils.h"
  19 #include "librbd/asio/ContextWQ.h"
  20 #include "librbd/journal/Types.h"
  21 #include "librbd/journal/TypeTraits.h"
  22
  23 #include <algorithm>
  24 #include <list>
  25 #include <string>
  26 #include <atomic>
  27 #include <unordered_map>
  28
  29 class ContextWQ;
  30 class SafeTimer;
  31 namespace journal { class Journaler; }
  32
  33 namespace librbd {
  34
  35 class ImageCtx;
  36
  37 namespace journal { template <typename> class Replay; }
  38
  39 template <typename ImageCtxT = ImageCtx>
  40 class Journal : public RefCountedObject {
  41 public:
  42   /**
  43    * @verbatim
  44    *
  45    * <start>
  46    *    |
  47    *    v
  48    * UNINITIALIZED ---> INITIALIZING ---> REPLAYING ------> FLUSHING ---> READY
  49    *    |                 *  .  ^             *  .              *           |
  50    *    |                 *  .  |             *  .              *           |
  51    *    |                 *  .  |    (error)  *  . . . . . . .  *           |
  52    *    |                 *  .  |             *              .  *           |
  53    *    |                 *  .  |             v              .  *           |
  54    *    |                 *  .  |         FLUSHING_RESTART   .  *           |
  55    *    |                 *  .  |             |              .  *           |
  56    *    |                 *  .  |             |              .  *           |
  57    *    |                 *  .  |             v              .  *           v
  58    *    |                 *  .  |         RESTARTING  < * * * * *       STOPPING
  59    *    |                 *  .  |             |              .              |
  60    *    |                 *  .  |             |              .              |
  61    *    |       * * * * * *  .  \-------------/              .              |
  62    *    |       * (error)    .                               .              |
  63    *    |       *            .   . . . . . . . . . . . . . . .              |
  64    *    |       *            .   .                                          |
  65    *    |       v            v   v                                          |
  66    *    |     CLOSED <----- CLOSING <---------------------------------------/
  67    *    |       |
  68    *    |       v
  69    *    \---> <finish>
  70    *
  71    * @endverbatim
  72    */
  73   enum State {
  74     STATE_UNINITIALIZED,
  75     STATE_INITIALIZING,
  76     STATE_REPLAYING,
  77     STATE_FLUSHING_RESTART,
  78     STATE_RESTARTING_REPLAY,
  79     STATE_FLUSHING_REPLAY,
  80     STATE_READY,
  81     STATE_STOPPING,
  82     STATE_CLOSING,
  83     STATE_CLOSED
  84   };
  85
  86   static const std::string IMAGE_CLIENT_ID;
  87   static const std::string LOCAL_MIRROR_UUID;
  88   static const std::string ORPHAN_MIRROR_UUID;
  89
  90   Journal(ImageCtxT &image_ctx);
  91   ~Journal();
  92
  93   static void get_work_queue(CephContext *cct, ContextWQ **work_queue);
  94
  95   static bool is_journal_supported(ImageCtxT &image_ctx);
  96   static int create(librados::IoCtx &io_ctx, const std::string &image_id,
  97                     uint8_t order, uint8_t splay_width,
  98                     const std::string &object_pool);
  99   static int remove(librados::IoCtx &io_ctx, const std::string &image_id);
 100   static int reset(librados::IoCtx &io_ctx, const std::string &image_id);
 101
 102   static void is_tag_owner(ImageCtxT *image_ctx, bool *is_tag_owner,
 103                            Context *on_finish);
 104   static void is_tag_owner(librados::IoCtx& io_ctx, std::string& image_id,
 105                            bool *is_tag_owner, asio::ContextWQ *op_work_queue,
 106                            Context *on_finish);
 107   static void get_tag_owner(librados::IoCtx& io_ctx, std::string& image_id,
 108                             std::string *mirror_uuid,
 109                             asio::ContextWQ *op_work_queue, Context *on_finish);
 110   static int request_resync(ImageCtxT *image_ctx);
 111   static void promote(ImageCtxT *image_ctx, Context *on_finish);
 112   static void demote(ImageCtxT *image_ctx, Context *on_finish);
 113
 114   bool is_journal_ready() const;
 115   bool is_journal_replaying() const;
 116   bool is_journal_appending() const;
 117
 118   void wait_for_journal_ready(Context *on_ready);
 119
 120   void open(Context *on_finish);
 121   void close(Context *on_finish);
 122
 123   bool is_tag_owner() const;
 124   uint64_t get_tag_tid() const;
 125   journal::TagData get_tag_data() const;
 126
 127   void allocate_local_tag(Context *on_finish);
 128   void allocate_tag(const std::string &mirror_uuid,
 129                     const journal::TagPredecessor &predecessor,
 130                     Context *on_finish);
 131
 132   void flush_commit_position(Context *on_finish);
 133
 134   void user_flushed();
 135
 136   uint64_t append_write_event(uint64_t offset, size_t length,
 137                               const bufferlist &bl,
 138                               bool flush_entry);
 139   uint64_t append_io_event(journal::EventEntry &&event_entry,
 140                            uint64_t offset, size_t length,
 141                            bool flush_entry, int filter_ret_val);
 142   void commit_io_event(uint64_t tid, int r);
 143   void commit_io_event_extent(uint64_t tid, uint64_t offset, uint64_t length,
 144                               int r);
 145
 146   void append_op_event(uint64_t op_tid, journal::EventEntry &&event_entry,
 147                        Context *on_safe);
 148   void commit_op_event(uint64_t tid, int r, Context *on_safe);
 149   void replay_op_ready(uint64_t op_tid, Context *on_resume);
 150
 151   void flush_event(uint64_t tid, Context *on_safe);
 152   void wait_event(uint64_t tid, Context *on_safe);
 153
 154   uint64_t allocate_op_tid() {
 155     uint64_t op_tid = ++m_op_tid;
 156     ceph_assert(op_tid != 0);
 157     return op_tid;
 158   }
 159
 160   void start_external_replay(journal::Replay<ImageCtxT> **journal_replay,
 161                              Context *on_start);
 162   void stop_external_replay();
 163
 164   void add_listener(journal::Listener *listener);
 165   void remove_listener(journal::Listener *listener);
 166
 167   int is_resync_requested(bool *do_resync);
 168
 169   inline ContextWQ *get_work_queue() {
 170     return m_work_queue;
 171   }
 172
 173 private:
 174   ImageCtxT &m_image_ctx;
 175
 176   // mock unit testing support
 177   typedef journal::TypeTraits<ImageCtxT> TypeTraits;
 178   typedef typename TypeTraits::Journaler Journaler;
 179   typedef typename TypeTraits::Future Future;
 180   typedef typename TypeTraits::ReplayEntry ReplayEntry;
 181
 182   typedef std::list<bufferlist> Bufferlists;
 183   typedef std::list<Context *> Contexts;
 184   typedef std::list<Future> Futures;
 185   typedef interval_set<uint64_t> ExtentInterval;
 186
 187   struct Event {
 188     Futures futures;
 189     Contexts on_safe_contexts;
 190     ExtentInterval pending_extents;
 191     int filter_ret_val = 0;
 192     bool committed_io = false;
 193     bool safe = false;
 194     int ret_val = 0;
 195
 196     Event() {
 197     }
 198     Event(const Futures &_futures, uint64_t offset, size_t length,
 199           int filter_ret_val)
 200       : futures(_futures), filter_ret_val(filter_ret_val) {
 201       if (length > 0) {
 202         pending_extents.insert(offset, length);
 203       }
 204     }
 205   };
 206
 207   typedef std::unordered_map<uint64_t, Event> Events;
 208   typedef std::unordered_map<uint64_t, Future> TidToFutures;
 209
 210   struct C_IOEventSafe : public Context {
 211     Journal *journal;
 212     uint64_t tid;
 213
 214     C_IOEventSafe(Journal *_journal, uint64_t _tid)
 215       : journal(_journal), tid(_tid) {
 216     }
 217
 218     void finish(int r) override {
 219       journal->handle_io_event_safe(r, tid);
 220     }
 221   };
 222
 223   struct C_OpEventSafe : public Context {
 224     Journal *journal;
 225     uint64_t tid;
 226     Future op_start_future;
 227     Future op_finish_future;
 228     Context *on_safe;
 229
 230     C_OpEventSafe(Journal *journal, uint64_t tid, const Future &op_start_future,
 231                   const Future &op_finish_future, Context *on_safe)
 232       : journal(journal), tid(tid), op_start_future(op_start_future),
 233         op_finish_future(op_finish_future), on_safe(on_safe) {
 234     }
 235
 236     void finish(int r) override {
 237       journal->handle_op_event_safe(r, tid, op_start_future, op_finish_future,
 238                                     on_safe);
 239     }
 240   };
 241
 242   struct C_ReplayProcessSafe : public Context {
 243     Journal *journal;
 244     ReplayEntry replay_entry;
 245
 246     C_ReplayProcessSafe(Journal *journal, ReplayEntry &&replay_entry) :
 247       journal(journal), replay_entry(std::move(replay_entry)) {
 248     }
 249     void finish(int r) override {
 250       journal->handle_replay_process_safe(replay_entry, r);
 251     }
 252   };
 253
 254   struct ReplayHandler : public ::journal::ReplayHandler {
 255     Journal *journal;
 256     ReplayHandler(Journal *_journal) : journal(_journal) {
 257     }
 258
 259     void handle_entries_available() override {
 260       journal->handle_replay_ready();
 261     }
 262     void handle_complete(int r) override {
 263       journal->handle_replay_complete(r);
 264     }
 265   };
 266
 267   ContextWQ *m_work_queue = nullptr;
 268   SafeTimer *m_timer = nullptr;
 269   ceph::mutex *m_timer_lock = nullptr;
 270
 271   Journaler *m_journaler;
 272   mutable ceph::mutex m_lock = ceph::make_mutex("Journal<I>::m_lock");
 273   State m_state;
 274   uint64_t m_max_append_size = 0;
 275   uint64_t m_tag_class = 0;
 276   uint64_t m_tag_tid = 0;
 277   journal::ImageClientMeta m_client_meta;
 278   journal::TagData m_tag_data;
 279
 280   int m_error_result;
 281   Contexts m_wait_for_state_contexts;
 282
 283   ReplayHandler m_replay_handler;
 284   bool m_close_pending;
 285
 286   ceph::mutex m_event_lock = ceph::make_mutex("Journal<I>::m_event_lock");
 287   uint64_t m_event_tid;
 288   Events m_events;
 289
 290   std::atomic<bool> m_user_flushed = false;
 291
 292   std::atomic<uint64_t> m_op_tid = { 0 };
 293   TidToFutures m_op_futures;
 294
 295   bool m_processing_entry = false;
 296   bool m_blocking_writes;
 297
 298   journal::Replay<ImageCtxT> *m_journal_replay;
 299
 300   AsyncOpTracker m_async_journal_op_tracker;
 301
 302   struct MetadataListener : public ::journal::JournalMetadataListener {
 303     Journal<ImageCtxT> *journal;
 304
 305     MetadataListener(Journal<ImageCtxT> *journal) : journal(journal) { }
 306
 307     void handle_update(::journal::JournalMetadata *) override;
 308   } m_metadata_listener;
 309
 310   typedef std::set<journal::Listener *> Listeners;
 311   Listeners m_listeners;
 312   ceph::condition_variable m_listener_cond;
 313   bool m_listener_notify = false;
 314
 315   uint64_t m_refresh_sequence = 0;
 316
 317   bool is_journal_replaying(const ceph::mutex &) const;
 318   bool is_tag_owner(const ceph::mutex &) const;
 319
 320   uint64_t append_io_events(journal::EventType event_type,
 321                             const Bufferlists &bufferlists,
 322                             uint64_t offset, size_t length, bool flush_entry,
 323                             int filter_ret_val);
 324   Future wait_event(ceph::mutex &lock, uint64_t tid, Context *on_safe);
 325
 326   void create_journaler();
 327   void destroy_journaler(int r);
 328   void recreate_journaler(int r);
 329
 330   void complete_event(typename Events::iterator it, int r);
 331
 332   void start_append();
 333
 334   void handle_open(int r);
 335
 336   void handle_replay_ready();
 337   void handle_replay_complete(int r);
 338   void handle_replay_process_ready(int r);
 339   void handle_replay_process_safe(ReplayEntry replay_entry, int r);
 340
 341   void handle_start_external_replay(int r,
 342                                     journal::Replay<ImageCtxT> **journal_replay,
 343                                     Context *on_finish);
 344
 345   void handle_flushing_restart(int r);
 346   void handle_flushing_replay();
 347
 348   void handle_recording_stopped(int r);
 349
 350   void handle_journal_destroyed(int r);
 351
 352   void handle_io_event_safe(int r, uint64_t tid);
 353   void handle_op_event_safe(int r, uint64_t tid, const Future &op_start_future,
 354                             const Future &op_finish_future, Context *on_safe);
 355
 356   void stop_recording();
 357
 358   void transition_state(State state, int r);
 359
 360   bool is_steady_state() const;
 361   void wait_for_steady_state(Context *on_state);
 362
 363   int check_resync_requested(bool *do_resync);
 364
 365   void handle_metadata_updated();
 366   void handle_refresh_metadata(uint64_t refresh_sequence, uint64_t tag_tid,
 367                                journal::TagData tag_data, int r);
 368
 369 };
 370
 371 } // namespace librbd
 372
 373 extern template class librbd::Journal<librbd::ImageCtx>;
 374
 375 #endif // CEPH_LIBRBD_JOURNAL_H