text: #ifndef BLOCK_H
  #define BLOCK_H
  
  #include "qemu-aio.h"
  #include "qemu-common.h"
  #include "qemu-option.h"
  #include "qemu-coroutine.h"
  #include "qobject.h"
  
  /* block.c */
  typedef struct BlockDriver BlockDriver;
  
  typedef struct BlockDriverInfo {
      /* in bytes, 0 if irrelevant */
      int cluster_size;
      /* offset at which the VM state can be saved (0 if not possible) */
      int64_t vm_state_offset;
  } BlockDriverInfo;
  
  typedef struct QEMUSnapshotInfo {
      char id_str[128]; /* unique snapshot id */
      /* the following fields are informative. They are not needed for
         the consistency of the snapshot */
      char name[256]; /* user choosen name */
      uint32_t vm_state_size; /* VM state info size */
      uint32_t date_sec; /* UTC date of the snapshot */
      uint32_t date_nsec;
      uint64_t vm_clock_nsec; /* VM clock relative to boot */
  } QEMUSnapshotInfo;
  
  /* Callbacks for block device models */
  typedef struct BlockDevOps {
      /*
       * Runs when virtual media changed (monitor commands eject, change)
       * Argument load is true on load and false on eject.
       * Beware: doesn't run when a host device's physical media
       * changes.  Sure would be useful if it did.
       * Device models with removable media must implement this callback.
       */
      void (*change_media_cb)(void *opaque, bool load);
      /*
       * Runs when an eject request is issued from the monitor, the tray
       * is closed, and the medium is locked.
       * Device models that do not implement is_medium_locked will not need
       * this callback.  Device models that can lock the medium or tray might
       * want to implement the callback and unlock the tray when "force" is
       * true, even if they do not support eject requests.
       */
      void (*eject_request_cb)(void *opaque, bool force);
      /*
       * Is the virtual tray open?
       * Device models implement this only when the device has a tray.
       */
      bool (*is_tray_open)(void *opaque);
      /*
       * Is the virtual medium locked into the device?
       * Device models implement this only when device has such a lock.
       */
      bool (*is_medium_locked)(void *opaque);
      /*
       * Runs when the size changed (e.g. monitor command block_resize)
       */
      void (*resize_cb)(void *opaque);
  } BlockDevOps;
  
  #define BDRV_O_RDWR        0x0002
  #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
  #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
  #define BDRV_O_CACHE_WB    0x0040 /* use write-back caching */
  #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
  #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
  #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
  
  #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
  
  #define BDRV_SECTOR_BITS   9
  #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
  #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
  
  typedef enum {
      BLOCK_ERR_REPORT, BLOCK_ERR_IGNORE, BLOCK_ERR_STOP_ENOSPC,
      BLOCK_ERR_STOP_ANY
  } BlockErrorAction;
  
  typedef enum {
      BDRV_ACTION_REPORT, BDRV_ACTION_IGNORE, BDRV_ACTION_STOP
  } BlockMonEventAction;
  
  void bdrv_iostatus_enable(BlockDriverState *bs);
  void bdrv_iostatus_reset(BlockDriverState *bs);
  void bdrv_iostatus_disable(BlockDriverState *bs);
  bool bdrv_iostatus_is_enabled(const BlockDriverState *bs);
  void bdrv_iostatus_set_err(BlockDriverState *bs, int error);
  void bdrv_mon_event(const BlockDriverState *bdrv,
                      BlockMonEventAction action, int is_read);
  void bdrv_info_print(Monitor *mon, const QObject *data);
  void bdrv_info(Monitor *mon, QObject **ret_data);
  void bdrv_stats_print(Monitor *mon, const QObject *data);
  void bdrv_info_stats(Monitor *mon, QObject **ret_data);
  
  void bdrv_init(void);
  void bdrv_init_with_whitelist(void);
  BlockDriver *bdrv_find_protocol(const char *filename);
  BlockDriver *bdrv_find_format(const char *format_name);
  BlockDriver *bdrv_find_whitelisted_format(const char *format_name);
  int bdrv_create(BlockDriver *drv, const char* filename,
      QEMUOptionParameter *options);
  int bdrv_create_file(const char* filename, QEMUOptionParameter *options);
  BlockDriverState *bdrv_new(const char *device_name);
  void bdrv_make_anon(BlockDriverState *bs);
  void bdrv_delete(BlockDriverState *bs);
  int bdrv_parse_cache_flags(const char *mode, int *flags);
  int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags);
  int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
                BlockDriver *drv);
  void bdrv_close(BlockDriverState *bs);
  int bdrv_attach_dev(BlockDriverState *bs, void *dev);
  void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev);
  void bdrv_detach_dev(BlockDriverState *bs, void *dev);
  void *bdrv_get_attached_dev(BlockDriverState *bs);
  void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
                        void *opaque);
  void bdrv_dev_eject_request(BlockDriverState *bs, bool force);
  bool bdrv_dev_has_removable_media(BlockDriverState *bs);
  bool bdrv_dev_is_tray_open(BlockDriverState *bs);
  bool bdrv_dev_is_medium_locked(BlockDriverState *bs);
  int bdrv_read(BlockDriverState *bs, int64_t sector_num,
                uint8_t *buf, int nb_sectors);
  int bdrv_write(BlockDriverState *bs, int64_t sector_num,
                 const uint8_t *buf, int nb_sectors);
  int bdrv_pread(BlockDriverState *bs, int64_t offset,
                 void *buf, int count);
  int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
                  const void *buf, int count);
  int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
      const void *buf, int count);
  int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
      int nb_sectors, QEMUIOVector *qiov);
  int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
      int nb_sectors, QEMUIOVector *qiov);
  int bdrv_truncate(BlockDriverState *bs, int64_t offset);
  int64_t bdrv_getlength(BlockDriverState *bs);
  int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
  void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
  void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs);
  int bdrv_commit(BlockDriverState *bs);
  void bdrv_commit_all(void);
  int bdrv_change_backing_file(BlockDriverState *bs,
      const char *backing_file, const char *backing_fmt);
  void bdrv_register(BlockDriver *bdrv);
  
  
  typedef struct BdrvCheckResult {
      int corruptions;
      int leaks;
      int check_errors;
  } BdrvCheckResult;
  
  int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res);
  
  /* async block I/O */
  typedef struct BlockDriverAIOCB BlockDriverAIOCB;
  typedef void BlockDriverCompletionFunc(void *opaque, int ret);
  typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector,
                                       int sector_num);
  BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
                                   QEMUIOVector *iov, int nb_sectors,
                                   BlockDriverCompletionFunc *cb, void *opaque);
  BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
                                    QEMUIOVector *iov, int nb_sectors,
                                    BlockDriverCompletionFunc *cb, void *opaque);
  BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
                                   BlockDriverCompletionFunc *cb, void *opaque);
  BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs,
                                     int64_t sector_num, int nb_sectors,
                                     BlockDriverCompletionFunc *cb, void *opaque);
  void bdrv_aio_cancel(BlockDriverAIOCB *acb);
  
  typedef struct BlockRequest {
      /* Fields to be filled by multiwrite caller */
      int64_t sector;
      int nb_sectors;
      QEMUIOVector *qiov;
      BlockDriverCompletionFunc *cb;
      void *opaque;
  
      /* Filled by multiwrite implementation */
      int error;
  } BlockRequest;
  
  int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs,
      int num_reqs);
  
  /* sg packet commands */
  int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
  BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
          unsigned long int req, void *buf,
          BlockDriverCompletionFunc *cb, void *opaque);
  
  /* Invalidate any cached metadata used by image formats */
  void bdrv_invalidate_cache(BlockDriverState *bs);
  void bdrv_invalidate_cache_all(void);
  
  /* Ensure contents are flushed to disk.  */
  int bdrv_flush(BlockDriverState *bs);
  int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
  void bdrv_flush_all(void);
  void bdrv_close_all(void);
  
  int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
  int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
  int bdrv_has_zero_init(BlockDriverState *bs);
  int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
                        int *pnum);
  
  #define BIOS_ATA_TRANSLATION_AUTO   0
  #define BIOS_ATA_TRANSLATION_NONE   1
  #define BIOS_ATA_TRANSLATION_LBA    2
  #define BIOS_ATA_TRANSLATION_LARGE  3
  #define BIOS_ATA_TRANSLATION_RECHS  4
  
  void bdrv_set_geometry_hint(BlockDriverState *bs,
                              int cyls, int heads, int secs);
  void bdrv_set_translation_hint(BlockDriverState *bs, int translation);
  void bdrv_get_geometry_hint(BlockDriverState *bs,
                              int *pcyls, int *pheads, int *psecs);
  typedef enum FDriveType {
      FDRIVE_DRV_144  = 0x00,   /* 1.44 MB 3"5 drive      */
      FDRIVE_DRV_288  = 0x01,   /* 2.88 MB 3"5 drive      */
      FDRIVE_DRV_120  = 0x02,   /* 1.2  MB 5"25 drive     */
      FDRIVE_DRV_NONE = 0x03,   /* No drive connected     */
  } FDriveType;
  
  void bdrv_get_floppy_geometry_hint(BlockDriverState *bs, int *nb_heads,
                                     int *max_track, int *last_sect,
                                     FDriveType drive_in, FDriveType *drive);
  int bdrv_get_translation_hint(BlockDriverState *bs);
  void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
                         BlockErrorAction on_write_error);
  BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read);
  int bdrv_is_read_only(BlockDriverState *bs);
  int bdrv_is_sg(BlockDriverState *bs);
  int bdrv_enable_write_cache(BlockDriverState *bs);
  int bdrv_is_inserted(BlockDriverState *bs);
  int bdrv_media_changed(BlockDriverState *bs);
  void bdrv_lock_medium(BlockDriverState *bs, bool locked);
  void bdrv_eject(BlockDriverState *bs, int eject_flag);
  void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size);
  BlockDriverState *bdrv_find(const char *name);
  BlockDriverState *bdrv_next(BlockDriverState *bs);
  void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs),
                    void *opaque);
  int bdrv_is_encrypted(BlockDriverState *bs);
  int bdrv_key_required(BlockDriverState *bs);
  int bdrv_set_key(BlockDriverState *bs, const char *key);
  int bdrv_query_missing_keys(void);
  void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
                           void *opaque);
  const char *bdrv_get_device_name(BlockDriverState *bs);
  int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
                            const uint8_t *buf, int nb_sectors);
  int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
  
  const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
  void bdrv_get_backing_filename(BlockDriverState *bs,
                                 char *filename, int filename_size);
  int bdrv_can_snapshot(BlockDriverState *bs);
  int bdrv_is_snapshot(BlockDriverState *bs);
  BlockDriverState *bdrv_snapshots(void);
  int bdrv_snapshot_create(BlockDriverState *bs,
                           QEMUSnapshotInfo *sn_info);
  int bdrv_snapshot_goto(BlockDriverState *bs,
                         const char *snapshot_id);
  int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
  int bdrv_snapshot_list(BlockDriverState *bs,
                         QEMUSnapshotInfo **psn_info);
  int bdrv_snapshot_load_tmp(BlockDriverState *bs,
                             const char *snapshot_name);
  char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn);
  
  char *get_human_readable_size(char *buf, int buf_size, int64_t size);
  int path_is_absolute(const char *path);
  void path_combine(char *dest, int dest_size,
                    const char *base_path,
                    const char *filename);
  
  int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
                        int64_t pos, int size);
  
  int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                        int64_t pos, int size);
  
  int bdrv_img_create(const char *filename, const char *fmt,
                      const char *base_filename, const char *base_fmt,
                      char *options, uint64_t img_size, int flags);
  
  void bdrv_set_buffer_alignment(BlockDriverState *bs, int align);
  void *qemu_blockalign(BlockDriverState *bs, size_t size);
  
  #define BDRV_SECTORS_PER_DIRTY_CHUNK 2048
  
  void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable);
  int bdrv_get_dirty(BlockDriverState *bs, int64_t sector);
  void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
                        int nr_sectors);
  int64_t bdrv_get_dirty_count(BlockDriverState *bs);
  
  void bdrv_set_in_use(BlockDriverState *bs, int in_use);
  int bdrv_in_use(BlockDriverState *bs);
  
  enum BlockAcctType {
      BDRV_ACCT_READ,
      BDRV_ACCT_WRITE,
      BDRV_ACCT_FLUSH,
      BDRV_MAX_IOTYPE,
  };
  
  typedef struct BlockAcctCookie {
      int64_t bytes;
      int64_t start_time_ns;
      enum BlockAcctType type;
  } BlockAcctCookie;
  
  void bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie,
          int64_t bytes, enum BlockAcctType type);
  void bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie);
  
  typedef enum {
      BLKDBG_L1_UPDATE,
  
      BLKDBG_L1_GROW_ALLOC_TABLE,
      BLKDBG_L1_GROW_WRITE_TABLE,
      BLKDBG_L1_GROW_ACTIVATE_TABLE,
  
      BLKDBG_L2_LOAD,
      BLKDBG_L2_UPDATE,
      BLKDBG_L2_UPDATE_COMPRESSED,
      BLKDBG_L2_ALLOC_COW_READ,
      BLKDBG_L2_ALLOC_WRITE,
  
      BLKDBG_READ,
      BLKDBG_READ_AIO,
      BLKDBG_READ_BACKING,
      BLKDBG_READ_BACKING_AIO,
      BLKDBG_READ_COMPRESSED,
  
      BLKDBG_WRITE_AIO,
      BLKDBG_WRITE_COMPRESSED,
  
      BLKDBG_VMSTATE_LOAD,
      BLKDBG_VMSTATE_SAVE,
  
      BLKDBG_COW_READ,
      BLKDBG_COW_WRITE,
  
      BLKDBG_REFTABLE_LOAD,
      BLKDBG_REFTABLE_GROW,
  
      BLKDBG_REFBLOCK_LOAD,
      BLKDBG_REFBLOCK_UPDATE,
      BLKDBG_REFBLOCK_UPDATE_PART,
      BLKDBG_REFBLOCK_ALLOC,
      BLKDBG_REFBLOCK_ALLOC_HOOKUP,
      BLKDBG_REFBLOCK_ALLOC_WRITE,
      BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS,
      BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE,
      BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE,
  
      BLKDBG_CLUSTER_ALLOC,
      BLKDBG_CLUSTER_ALLOC_BYTES,
      BLKDBG_CLUSTER_FREE,
  
      BLKDBG_EVENT_MAX,
  } BlkDebugEvent;
  
  #define BLKDBG_EVENT(bs, evt) bdrv_debug_event(bs, evt)
  void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event);
  
  
  /* Convenience for block device models */
  
  typedef struct BlockConf {
      BlockDriverState *bs;
      uint16_t physical_block_size;
      uint16_t logical_block_size;
      uint16_t min_io_size;
      uint32_t opt_io_size;
      int32_t bootindex;
      uint32_t discard_granularity;
  } BlockConf;
  
  static inline unsigned int get_physical_block_exp(BlockConf *conf)
  {
      unsigned int exp = 0, size;
  
      for (size = conf->physical_block_size;
          size > conf->logical_block_size;
          size >>= 1) {
          exp++;
      }
  
      return exp;
  }
  
  #define DEFINE_BLOCK_PROPERTIES(_state, _conf)                          \
      DEFINE_PROP_DRIVE("drive", _state, _conf.bs),                       \
      DEFINE_PROP_UINT16("logical_block_size", _state,                    \
                         _conf.logical_block_size, 512),                  \
      DEFINE_PROP_UINT16("physical_block_size", _state,                   \
                         _conf.physical_block_size, 512),                 \
      DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 0),  \
      DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 0),    \
      DEFINE_PROP_INT32("bootindex", _state, _conf.bootindex, -1),        \
      DEFINE_PROP_UINT32("discard_granularity", _state, \
                         _conf.discard_granularity, 0)
  
  #endif
  
  