/*
   * Copyright (C) 2011 Red Hat, Inc.
   *
   * This file is released under the GPL.
   */
  
  #ifndef DM_SPACE_MAP_METADATA_H
  #define DM_SPACE_MAP_METADATA_H
  
  #include "dm-transaction-manager.h"
  
  #define DM_SM_METADATA_BLOCK_SIZE (4096 >> SECTOR_SHIFT)
  
  /*
   * The metadata device is currently limited in size.
   *
   * We have one block of index, which can hold 255 index entries.  Each
   * index entry contains allocation info about ~16k metadata blocks.
   */
  #define DM_SM_METADATA_MAX_BLOCKS (255 * ((1 << 14) - 64))
  #define DM_SM_METADATA_MAX_SECTORS (DM_SM_METADATA_MAX_BLOCKS * DM_SM_METADATA_BLOCK_SIZE)
  
  /*
   * Unfortunately we have to use two-phase construction due to the cycle
   * between the tm and sm.
   */
  struct dm_space_map *dm_sm_metadata_init(void);
  
  /*
   * Create a fresh space map.
   */
  int dm_sm_metadata_create(struct dm_space_map *sm,
  			  struct dm_transaction_manager *tm,
  			  dm_block_t nr_blocks,
  			  dm_block_t superblock);
  
  /*
   * Open from a previously-recorded root.
   */
  int dm_sm_metadata_open(struct dm_space_map *sm,
  			struct dm_transaction_manager *tm,
  			void *root_le, size_t len);
  
  #endif	/* DM_SPACE_MAP_METADATA_H */