ceph/src/os/bluestore/BlueFS.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_OS_BLUESTORE_BLUEFS_H
   4 #define CEPH_OS_BLUESTORE_BLUEFS_H
   5
   6 #include <atomic>
   7 #include <mutex>
   8 #include <limits>
   9
  10 #include "bluefs_types.h"
  11 #include "blk/BlockDevice.h"
  12
  13 #include "common/RefCountedObj.h"
  14 #include "common/ceph_context.h"
  15 #include "global/global_context.h"
  16 #include "include/common_fwd.h"
  17
  18 #include "boost/intrusive/list.hpp"
  19 #include "boost/dynamic_bitset.hpp"
  20
  21 class Allocator;
  22
  23 enum {
  24   l_bluefs_first = 732600,
  25   l_bluefs_db_total_bytes,
  26   l_bluefs_db_used_bytes,
  27   l_bluefs_wal_total_bytes,
  28   l_bluefs_wal_used_bytes,
  29   l_bluefs_slow_total_bytes,
  30   l_bluefs_slow_used_bytes,
  31   l_bluefs_num_files,
  32   l_bluefs_log_bytes,
  33   l_bluefs_log_compactions,
  34   l_bluefs_logged_bytes,
  35   l_bluefs_files_written_wal,
  36   l_bluefs_files_written_sst,
  37   l_bluefs_bytes_written_wal,
  38   l_bluefs_bytes_written_sst,
  39   l_bluefs_bytes_written_slow,
  40   l_bluefs_max_bytes_wal,
  41   l_bluefs_max_bytes_db,
  42   l_bluefs_max_bytes_slow,
  43   l_bluefs_main_alloc_unit,
  44   l_bluefs_db_alloc_unit,
  45   l_bluefs_wal_alloc_unit,
  46   l_bluefs_read_random_count,
  47   l_bluefs_read_random_bytes,
  48   l_bluefs_read_random_disk_count,
  49   l_bluefs_read_random_disk_bytes,
  50   l_bluefs_read_random_disk_bytes_wal,
  51   l_bluefs_read_random_disk_bytes_db,
  52   l_bluefs_read_random_disk_bytes_slow,
  53   l_bluefs_read_random_buffer_count,
  54   l_bluefs_read_random_buffer_bytes,
  55   l_bluefs_read_count,
  56   l_bluefs_read_bytes,
  57   l_bluefs_read_disk_count,
  58   l_bluefs_read_disk_bytes,
  59   l_bluefs_read_disk_bytes_wal,
  60   l_bluefs_read_disk_bytes_db,
  61   l_bluefs_read_disk_bytes_slow,
  62   l_bluefs_read_prefetch_count,
  63   l_bluefs_read_prefetch_bytes,
  64   l_bluefs_read_zeros_candidate,
  65   l_bluefs_read_zeros_errors,
  66
  67   l_bluefs_last,
  68 };
  69
  70 class BlueFSVolumeSelector {
  71 public:
  72   typedef std::vector<std::pair<std::string, uint64_t>> paths;
  73
  74   virtual ~BlueFSVolumeSelector() {
  75   }
  76   virtual void* get_hint_for_log() const = 0;
  77   virtual void* get_hint_by_dir(std::string_view dirname) const = 0;
  78
  79   virtual void add_usage(void* file_hint, const bluefs_fnode_t& fnode) = 0;
  80   virtual void sub_usage(void* file_hint, const bluefs_fnode_t& fnode) = 0;
  81   virtual void add_usage(void* file_hint, uint64_t fsize) = 0;
  82   virtual void sub_usage(void* file_hint, uint64_t fsize) = 0;
  83   virtual uint8_t select_prefer_bdev(void* hint) = 0;
  84   virtual void get_paths(const std::string& base, paths& res) const = 0;
  85   virtual void dump(std::ostream& sout) = 0;
  86
  87   /* used for sanity checking of vselector */
  88   virtual BlueFSVolumeSelector* clone_empty() const { return nullptr; }
  89   virtual bool compare(BlueFSVolumeSelector* other) { return true; };
  90 };
  91
  92 struct bluefs_shared_alloc_context_t {
  93   bool need_init = false;
  94   Allocator* a = nullptr;
  95
  96   std::atomic<uint64_t> bluefs_used = 0;
  97
  98   void set(Allocator* _a) {
  99     a = _a;
 100     need_init = true;
 101     bluefs_used = 0;
 102   }
 103   void reset() {
 104     a = nullptr;
 105   }
 106 };
 107
 108 class BlueFS {
 109 public:
 110   CephContext* cct;
 111   static constexpr unsigned MAX_BDEV = 5;
 112   static constexpr unsigned BDEV_WAL = 0;
 113   static constexpr unsigned BDEV_DB = 1;
 114   static constexpr unsigned BDEV_SLOW = 2;
 115   static constexpr unsigned BDEV_NEWWAL = 3;
 116   static constexpr unsigned BDEV_NEWDB = 4;
 117
 118   enum {
 119     WRITER_UNKNOWN,
 120     WRITER_WAL,
 121     WRITER_SST,
 122   };
 123
 124   struct File : public RefCountedObject {
 125     MEMPOOL_CLASS_HELPERS();
 126
 127     bluefs_fnode_t fnode;
 128     int refs;
 129     uint64_t dirty_seq;
 130     bool locked;
 131     bool deleted;
 132     bool is_dirty;
 133     boost::intrusive::list_member_hook<> dirty_item;
 134
 135     std::atomic_int num_readers, num_writers;
 136     std::atomic_int num_reading;
 137
 138     void* vselector_hint = nullptr;
 139     /* lock protects fnode and other the parts that can be modified during read & write operations.
 140        Does not protect values that are fixed
 141        Does not need to be taken when doing one-time operations:
 142        _replay, device_migrate_to_existing, device_migrate_to_new */
 143     ceph::mutex lock = ceph::make_mutex("BlueFS::File::lock");
 144
 145   private:
 146     FRIEND_MAKE_REF(File);
 147     File()
 148       :
 149         refs(0),
 150         dirty_seq(0),
 151         locked(false),
 152         deleted(false),
 153         is_dirty(false),
 154         num_readers(0),
 155         num_writers(0),
 156         num_reading(0),
 157         vselector_hint(nullptr)
 158       {}
 159     ~File() override {
 160       ceph_assert(num_readers.load() == 0);
 161       ceph_assert(num_writers.load() == 0);
 162       ceph_assert(num_reading.load() == 0);
 163       ceph_assert(!locked);
 164     }
 165   };
 166   using FileRef = ceph::ref_t<File>;
 167
 168   typedef boost::intrusive::list<
 169       File,
 170       boost::intrusive::member_hook<
 171         File,
 172         boost::intrusive::list_member_hook<>,
 173         &File::dirty_item> > dirty_file_list_t;
 174
 175   struct Dir : public RefCountedObject {
 176     MEMPOOL_CLASS_HELPERS();
 177
 178     mempool::bluefs::map<std::string, FileRef, std::less<>> file_map;
 179
 180   private:
 181     FRIEND_MAKE_REF(Dir);
 182     Dir() = default;
 183   };
 184   using DirRef = ceph::ref_t<Dir>;
 185
 186   struct FileWriter {
 187     MEMPOOL_CLASS_HELPERS();
 188
 189     FileRef file;
 190     uint64_t pos = 0;       ///< start offset for buffer
 191   private:
 192     ceph::buffer::list buffer;      ///< new data to write (at end of file)
 193     ceph::buffer::list tail_block;  ///< existing partial block at end of file, if any
 194   public:
 195     unsigned get_buffer_length() const {
 196       return buffer.length();
 197     }
 198     ceph::bufferlist flush_buffer(
 199       CephContext* cct,
 200       const bool partial,
 201       const unsigned length,
 202       const bluefs_super_t& super);
 203     ceph::buffer::list::page_aligned_appender buffer_appender;  //< for const char* only
 204   public:
 205     int writer_type = 0;    ///< WRITER_*
 206     int write_hint = WRITE_LIFE_NOT_SET;
 207
 208     ceph::mutex lock = ceph::make_mutex("BlueFS::FileWriter::lock");
 209     std::array<IOContext*,MAX_BDEV> iocv; ///< for each bdev
 210     std::array<bool, MAX_BDEV> dirty_devs;
 211
 212     FileWriter(FileRef f)
 213       : file(std::move(f)),
 214        buffer_appender(buffer.get_page_aligned_appender(
 215                          g_conf()->bluefs_alloc_size / CEPH_PAGE_SIZE)) {
 216       ++file->num_writers;
 217       iocv.fill(nullptr);
 218       dirty_devs.fill(false);
 219       if (file->fnode.ino == 1) {
 220         write_hint = WRITE_LIFE_MEDIUM;
 221       }
 222     }
 223     // NOTE: caller must call BlueFS::close_writer()
 224     ~FileWriter() {
 225       --file->num_writers;
 226     }
 227
 228     // note: BlueRocksEnv uses this append exclusively, so it's safe
 229     // to use buffer_appender exclusively here (e.g., its notion of
 230     // offset will remain accurate).
 231     void append(const char *buf, size_t len) {
 232       uint64_t l0 = get_buffer_length();
 233       ceph_assert(l0 + len <= std::numeric_limits<unsigned>::max());
 234       buffer_appender.append(buf, len);
 235     }
 236
 237     void append(const std::byte *buf, size_t len) {
 238       // allow callers to use byte type instead of char* as we simply pass byte array
 239       append((const char*)buf, len);
 240     }
 241
 242     // note: used internally only, for ino 1 or 0.
 243     void append(ceph::buffer::list& bl) {
 244       uint64_t l0 = get_buffer_length();
 245       ceph_assert(l0 + bl.length() <= std::numeric_limits<unsigned>::max());
 246       buffer.claim_append(bl);
 247     }
 248
 249     void append_zero(size_t len) {
 250       uint64_t l0 = get_buffer_length();
 251       ceph_assert(l0 + len <= std::numeric_limits<unsigned>::max());
 252       buffer_appender.append_zero(len);
 253     }
 254
 255     uint64_t get_effective_write_pos() {
 256       return pos + buffer.length();
 257     }
 258   };
 259
 260   struct FileReaderBuffer {
 261     MEMPOOL_CLASS_HELPERS();
 262
 263     uint64_t bl_off = 0;    ///< prefetch buffer logical offset
 264     ceph::buffer::list bl;          ///< prefetch buffer
 265     uint64_t pos = 0;       ///< current logical offset
 266     uint64_t max_prefetch;  ///< max allowed prefetch
 267
 268     explicit FileReaderBuffer(uint64_t mpf)
 269       : max_prefetch(mpf) {}
 270
 271     uint64_t get_buf_end() const {
 272       return bl_off + bl.length();
 273     }
 274     uint64_t get_buf_remaining(uint64_t p) const {
 275       if (p >= bl_off && p < bl_off + bl.length())
 276         return bl_off + bl.length() - p;
 277       return 0;
 278     }
 279
 280     void skip(size_t n) {
 281       pos += n;
 282     }
 283
 284     // For the sake of simplicity, we invalidate completed rather than
 285     // for the provided extent
 286     void invalidate_cache(uint64_t offset, uint64_t length) {
 287       if (offset >= bl_off && offset < get_buf_end()) {
 288         bl.clear();
 289         bl_off = 0;
 290       }
 291     }
 292   };
 293
 294   struct FileReader {
 295     MEMPOOL_CLASS_HELPERS();
 296
 297     FileRef file;
 298     FileReaderBuffer buf;
 299     bool random;
 300     bool ignore_eof;        ///< used when reading our log file
 301
 302     ceph::shared_mutex lock {
 303      ceph::make_shared_mutex(std::string(), false, false, false)
 304     };
 305
 306
 307     FileReader(FileRef f, uint64_t mpf, bool rand, bool ie)
 308       : file(f),
 309         buf(mpf),
 310         random(rand),
 311         ignore_eof(ie) {
 312       ++file->num_readers;
 313     }
 314     ~FileReader() {
 315       --file->num_readers;
 316     }
 317   };
 318
 319   struct FileLock {
 320     MEMPOOL_CLASS_HELPERS();
 321
 322     FileRef file;
 323     explicit FileLock(FileRef f) : file(std::move(f)) {}
 324   };
 325
 326 private:
 327   PerfCounters *logger = nullptr;
 328
 329   uint64_t max_bytes[MAX_BDEV] = {0};
 330   uint64_t max_bytes_pcounters[MAX_BDEV] = {
 331     l_bluefs_max_bytes_wal,
 332     l_bluefs_max_bytes_db,
 333     l_bluefs_max_bytes_slow,
 334   };
 335
 336   // cache
 337   struct {
 338     ceph::mutex lock = ceph::make_mutex("BlueFS::nodes.lock");
 339     mempool::bluefs::map<std::string, DirRef, std::less<>> dir_map; ///< dirname -> Dir
 340     mempool::bluefs::unordered_map<uint64_t, FileRef> file_map;     ///< ino -> File
 341   } nodes;
 342
 343   bluefs_super_t super;        ///< latest superblock (as last written)
 344   uint64_t ino_last = 0;       ///< last assigned ino (this one is in use)
 345
 346   struct {
 347     ceph::mutex lock = ceph::make_mutex("BlueFS::log.lock");
 348     uint64_t seq_live = 1;   //seq that log is currently writing to; mirrors dirty.seq_live
 349     FileWriter *writer = 0;
 350     bluefs_transaction_t t;
 351   } log;
 352
 353   struct {
 354     ceph::mutex lock = ceph::make_mutex("BlueFS::dirty.lock");
 355     uint64_t seq_stable = 0; //seq that is now stable on disk
 356     uint64_t seq_live = 1;   //seq that is ongoing and dirty files will be written to
 357     // map of dirty files, files of same dirty_seq are grouped into list.
 358     std::map<uint64_t, dirty_file_list_t> files;
 359     std::vector<interval_set<uint64_t>> pending_release; ///< extents to release
 360     // TODO: it should be examined what makes pending_release immune to
 361     // eras in a way similar to dirty_files. Hints:
 362     // 1) we have actually only 2 eras: log_seq and log_seq+1
 363     // 2) we usually not remove extents from files. And when we do, we force log-syncing.
 364   } dirty;
 365
 366   ceph::condition_variable log_cond;                             ///< used for state control between log flush / log compaction
 367   std::atomic<bool> log_is_compacting{false};                    ///< signals that bluefs log is already ongoing compaction
 368   std::atomic<bool> log_forbidden_to_expand{false};              ///< used to signal that async compaction is in state
 369                                                                  ///  that prohibits expansion of bluefs log
 370   /*
 371    * There are up to 3 block devices:
 372    *
 373    *  BDEV_DB   db/      - the primary db device
 374    *  BDEV_WAL  db.wal/  - a small, fast device, specifically for the WAL
 375    *  BDEV_SLOW db.slow/ - a big, slow device, to spill over to as BDEV_DB fills
 376    */
 377   std::vector<BlockDevice*> bdev;                  ///< block devices we can use
 378   std::vector<IOContext*> ioc;                     ///< IOContexts for bdevs
 379   std::vector<uint64_t> block_reserved;            ///< starting reserve extent per device
 380   std::vector<Allocator*> alloc;                   ///< allocators for bdevs
 381   std::vector<uint64_t> alloc_size;                ///< alloc size for each device
 382
 383   //std::vector<interval_set<uint64_t>> block_unused_too_granular;
 384
 385   BlockDevice::aio_callback_t discard_cb[3]; //discard callbacks for each dev
 386
 387   std::unique_ptr<BlueFSVolumeSelector> vselector;
 388
 389   bluefs_shared_alloc_context_t* shared_alloc = nullptr;
 390   unsigned shared_alloc_id = unsigned(-1);
 391   inline bool is_shared_alloc(unsigned id) const {
 392     return id == shared_alloc_id;
 393   }
 394
 395   class SocketHook;
 396   SocketHook* asok_hook = nullptr;
 397   // used to trigger zeros into read (debug / verify)
 398   std::atomic<uint64_t> inject_read_zeros{0};
 399
 400   void _init_logger();
 401   void _shutdown_logger();
 402   void _update_logger_stats();
 403
 404   void _init_alloc();
 405   void _stop_alloc();
 406
 407   void _pad_bl(ceph::buffer::list& bl);  ///< pad ceph::buffer::list to block size w/ zeros
 408
 409   uint64_t _get_used(unsigned id) const;
 410   uint64_t _get_total(unsigned id) const;
 411
 412
 413   FileRef _get_file(uint64_t ino);
 414   void _drop_link_D(FileRef f);
 415
 416   unsigned _get_slow_device_id() {
 417     return bdev[BDEV_SLOW] ? BDEV_SLOW : BDEV_DB;
 418   }
 419   const char* get_device_name(unsigned id);
 420   int _allocate(uint8_t bdev, uint64_t len,
 421                 bluefs_fnode_t* node);
 422   int _allocate_without_fallback(uint8_t id, uint64_t len,
 423                                  PExtentVector* extents);
 424
 425   /* signal replay log to include h->file in nearest log flush */
 426   int _signal_dirty_to_log_D(FileWriter *h);
 427   int _flush_range_F(FileWriter *h, uint64_t offset, uint64_t length);
 428   int _flush_data(FileWriter *h, uint64_t offset, uint64_t length, bool buffered);
 429   int _flush_F(FileWriter *h, bool force, bool *flushed = nullptr);
 430   uint64_t _flush_special(FileWriter *h);
 431   int _fsync(FileWriter *h);
 432
 433 #ifdef HAVE_LIBAIO
 434   void _claim_completed_aios(FileWriter *h, std::list<aio_t> *ls);
 435   void _wait_for_aio(FileWriter *h);  // safe to call without a lock
 436 #endif
 437
 438   int64_t _maybe_extend_log();
 439   void _extend_log();
 440   uint64_t _log_advance_seq();
 441   void _consume_dirty(uint64_t seq);
 442   void _clear_dirty_set_stable_D(uint64_t seq_stable);
 443   void _release_pending_allocations(std::vector<interval_set<uint64_t>>& to_release);
 444
 445   void _flush_and_sync_log_core(int64_t available_runway);
 446   int _flush_and_sync_log_jump_D(uint64_t jump_to,
 447                                int64_t available_runway);
 448   int _flush_and_sync_log_LD(uint64_t want_seq = 0);
 449
 450   uint64_t _estimate_log_size_N();
 451   bool _should_start_compact_log_L_N();
 452
 453   enum {
 454     REMOVE_DB = 1,
 455     REMOVE_WAL = 2,
 456     RENAME_SLOW2DB = 4,
 457     RENAME_DB2SLOW = 8,
 458   };
 459   void _compact_log_dump_metadata_NF(bluefs_transaction_t *t,
 460                                  int flags);
 461   void _compact_log_async_dump_metadata_NF(bluefs_transaction_t *t,
 462                                            uint64_t capture_before_seq);
 463
 464   void _compact_log_sync_LNF_LD();
 465   void _compact_log_async_LD_LNF_D();
 466
 467   void _rewrite_log_and_layout_sync_LNF_LD(bool allocate_with_fallback,
 468                                     int super_dev,
 469                                     int log_dev,
 470                                     int new_log_dev,
 471                                     int flags,
 472                                     std::optional<bluefs_layout_t> layout);
 473
 474   //void _aio_finish(void *priv);
 475
 476   void _flush_bdev(FileWriter *h);
 477   void _flush_bdev();  // this is safe to call without a lock
 478   void _flush_bdev(std::array<bool, MAX_BDEV>& dirty_bdevs);  // this is safe to call without a lock
 479
 480   int _preallocate(FileRef f, uint64_t off, uint64_t len);
 481   int _truncate(FileWriter *h, uint64_t off);
 482
 483   int64_t _read(
 484     FileReader *h,   ///< [in] read from here
 485     uint64_t offset, ///< [in] offset
 486     size_t len,      ///< [in] this many bytes
 487     ceph::buffer::list *outbl,   ///< [out] optional: reference the result here
 488     char *out);      ///< [out] optional: or copy it here
 489   int64_t _read_random(
 490     FileReader *h,   ///< [in] read from here
 491     uint64_t offset, ///< [in] offset
 492     uint64_t len,    ///< [in] this many bytes
 493     char *out);      ///< [out] optional: or copy it here
 494
 495   int _open_super();
 496   int _write_super(int dev);
 497   int _check_allocations(const bluefs_fnode_t& fnode,
 498     boost::dynamic_bitset<uint64_t>* used_blocks,
 499     bool is_alloc, //true when allocating, false when deallocating
 500     const char* op_name);
 501   int _verify_alloc_granularity(
 502     __u8 id, uint64_t offset, uint64_t length,
 503     const char *op);
 504   int _replay(bool noop, bool to_stdout = false); ///< replay journal
 505
 506   FileWriter *_create_writer(FileRef f);
 507   void _drain_writer(FileWriter *h);
 508   void _close_writer(FileWriter *h);
 509
 510   // always put the super in the second 4k block.  FIXME should this be
 511   // block size independent?
 512   unsigned get_super_offset() {
 513     return 4096;
 514   }
 515   unsigned get_super_length() {
 516     return 4096;
 517   }
 518   void _maybe_check_vselector_LNF() {
 519     if (cct->_conf->bluefs_check_volume_selector_often) {
 520       _check_vselector_LNF();
 521     }
 522   }
 523 public:
 524   BlueFS(CephContext* cct);
 525   ~BlueFS();
 526
 527   // the super is always stored on bdev 0
 528   int mkfs(uuid_d osd_uuid, const bluefs_layout_t& layout);
 529   int mount();
 530   int maybe_verify_layout(const bluefs_layout_t& layout) const;
 531   void umount(bool avoid_compact = false);
 532   int prepare_new_device(int id, const bluefs_layout_t& layout);
 533
 534   int log_dump();
 535
 536   void collect_metadata(std::map<std::string,std::string> *pm, unsigned skip_bdev_id);
 537   void get_devices(std::set<std::string> *ls);
 538   uint64_t get_alloc_size(int id) {
 539     return alloc_size[id];
 540   }
 541   int fsck();
 542
 543   int device_migrate_to_new(
 544     CephContext *cct,
 545     const std::set<int>& devs_source,
 546     int dev_target,
 547     const bluefs_layout_t& layout);
 548   int device_migrate_to_existing(
 549     CephContext *cct,
 550     const std::set<int>& devs_source,
 551     int dev_target,
 552     const bluefs_layout_t& layout);
 553
 554   uint64_t get_used();
 555   uint64_t get_total(unsigned id);
 556   uint64_t get_free(unsigned id);
 557   uint64_t get_used(unsigned id);
 558   void dump_perf_counters(ceph::Formatter *f);
 559
 560   void dump_block_extents(std::ostream& out);
 561
 562   /// get current extents that we own for given block device
 563   int get_block_extents(unsigned id, interval_set<uint64_t> *extents);
 564
 565   int open_for_write(
 566     std::string_view dir,
 567     std::string_view file,
 568     FileWriter **h,
 569     bool overwrite);
 570
 571   int open_for_read(
 572     std::string_view dir,
 573     std::string_view file,
 574     FileReader **h,
 575     bool random = false);
 576
 577   // data added after last fsync() is lost
 578   void close_writer(FileWriter *h);
 579
 580   int rename(std::string_view old_dir, std::string_view old_file,
 581              std::string_view new_dir, std::string_view new_file);
 582
 583   int readdir(std::string_view dirname, std::vector<std::string> *ls);
 584
 585   int unlink(std::string_view dirname, std::string_view filename);
 586   int mkdir(std::string_view dirname);
 587   int rmdir(std::string_view dirname);
 588   bool wal_is_rotational();
 589   bool db_is_rotational();
 590
 591   bool dir_exists(std::string_view dirname);
 592   int stat(std::string_view dirname, std::string_view filename,
 593            uint64_t *size, utime_t *mtime);
 594
 595   int lock_file(std::string_view dirname, std::string_view filename, FileLock **p);
 596   int unlock_file(FileLock *l);
 597
 598   void compact_log();
 599
 600   /// sync any uncommitted state to disk
 601   void sync_metadata(bool avoid_compact);
 602
 603   void set_volume_selector(BlueFSVolumeSelector* s) {
 604     vselector.reset(s);
 605   }
 606   void dump_volume_selector(std::ostream& sout) {
 607     vselector->dump(sout);
 608   }
 609   void get_vselector_paths(const std::string& base,
 610                            BlueFSVolumeSelector::paths& res) const {
 611     return vselector->get_paths(base, res);
 612   }
 613
 614   int add_block_device(unsigned bdev, const std::string& path, bool trim,
 615                        uint64_t reserved,
 616                        bluefs_shared_alloc_context_t* _shared_alloc = nullptr);
 617   bool bdev_support_label(unsigned id);
 618   uint64_t get_block_device_size(unsigned bdev) const;
 619
 620   // handler for discard event
 621   void handle_discard(unsigned dev, interval_set<uint64_t>& to_release);
 622
 623   void flush(FileWriter *h, bool force = false);
 624
 625   void append_try_flush(FileWriter *h, const char* buf, size_t len);
 626   void flush_range(FileWriter *h, uint64_t offset, uint64_t length);
 627   int fsync(FileWriter *h);
 628   int64_t read(FileReader *h, uint64_t offset, size_t len,
 629            ceph::buffer::list *outbl, char *out) {
 630     // no need to hold the global lock here; we only touch h and
 631     // h->file, and read vs write or delete is already protected (via
 632     // atomics and asserts).
 633     return _read(h, offset, len, outbl, out);
 634   }
 635   int64_t read_random(FileReader *h, uint64_t offset, size_t len,
 636                   char *out) {
 637     // no need to hold the global lock here; we only touch h and
 638     // h->file, and read vs write or delete is already protected (via
 639     // atomics and asserts).
 640     return _read_random(h, offset, len, out);
 641   }
 642   void invalidate_cache(FileRef f, uint64_t offset, uint64_t len);
 643   int preallocate(FileRef f, uint64_t offset, uint64_t len);
 644   int truncate(FileWriter *h, uint64_t offset);
 645
 646   size_t probe_alloc_avail(int dev, uint64_t alloc_size);
 647
 648   /// test purpose methods
 649   const PerfCounters* get_perf_counters() const {
 650     return logger;
 651   }
 652   uint64_t debug_get_dirty_seq(FileWriter *h);
 653   bool debug_get_is_dev_dirty(FileWriter *h, uint8_t dev);
 654
 655 private:
 656   // Wrappers for BlockDevice::read(...) and BlockDevice::read_random(...)
 657   // They are used for checking if read values are all 0, and reread if so.
 658   int _read_and_check(uint8_t ndev, uint64_t off, uint64_t len,
 659            ceph::buffer::list *pbl, IOContext *ioc, bool buffered);
 660   int _read_random_and_check(uint8_t ndev, uint64_t off, uint64_t len, char *buf, bool buffered);
 661
 662   int _bdev_read(uint8_t ndev, uint64_t off, uint64_t len,
 663     ceph::buffer::list* pbl, IOContext* ioc, bool buffered);
 664   int _bdev_read_random(uint8_t ndev, uint64_t off, uint64_t len, char* buf, bool buffered);
 665
 666   /// test and compact log, if necessary
 667   void _maybe_compact_log_LNF_NF_LD_D();
 668   int _do_replay_recovery_read(FileReader *log,
 669                                size_t log_pos,
 670                                size_t read_offset,
 671                                size_t read_len,
 672                                bufferlist* bl);
 673   void _check_vselector_LNF();
 674 };
 675
 676 class OriginalVolumeSelector : public BlueFSVolumeSelector {
 677   uint64_t wal_total;
 678   uint64_t db_total;
 679   uint64_t slow_total;
 680
 681 public:
 682   OriginalVolumeSelector(
 683     uint64_t _wal_total,
 684     uint64_t _db_total,
 685     uint64_t _slow_total)
 686     : wal_total(_wal_total), db_total(_db_total), slow_total(_slow_total) {}
 687
 688   void* get_hint_for_log() const override;
 689   void* get_hint_by_dir(std::string_view dirname) const override;
 690
 691   void add_usage(void* hint, const bluefs_fnode_t& fnode) override {
 692     // do nothing
 693     return;
 694   }
 695   void sub_usage(void* hint, const bluefs_fnode_t& fnode) override {
 696     // do nothing
 697     return;
 698   }
 699   void add_usage(void* hint, uint64_t fsize) override {
 700     // do nothing
 701     return;
 702   }
 703   void sub_usage(void* hint, uint64_t fsize) override {
 704     // do nothing
 705     return;
 706   }
 707
 708   uint8_t select_prefer_bdev(void* hint) override;
 709   void get_paths(const std::string& base, paths& res) const override;
 710   void dump(std::ostream& sout) override;
 711 };
 712
 713 class FitToFastVolumeSelector : public OriginalVolumeSelector {
 714 public:
 715   FitToFastVolumeSelector(
 716     uint64_t _wal_total,
 717     uint64_t _db_total,
 718     uint64_t _slow_total)
 719     : OriginalVolumeSelector(_wal_total, _db_total, _slow_total) {}
 720
 721   void get_paths(const std::string& base, paths& res) const override;
 722 };
 723 /**
 724  * Directional graph of locks.
 725  * Vertices - Locks. Edges (directed) - locking progression.
 726  * Edge A->B exist if last taken lock was A and next taken lock is B.
 727  *
 728  * Row represents last lock taken.
 729  * Column represents next lock taken.
 730  *
 731  *     >        | W | L | N | D | F
 732  * -------------|---|---|---|---|---
 733  * FileWriter W |   | > | > | > | >
 734  * log        L |       | > | > | >
 735  * nodes      N |           | > | >
 736  * dirty      D |           |   | >
 737  * File       F |
 738  *
 739  * Claim: Deadlock is possible IFF graph contains cycles.
 740  */
 741 #endif