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Joe Thornber3241b1d2011-10-31 20:19:11 +00001/*
2 * Copyright (C) 2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7#ifndef DM_SPACE_MAP_METADATA_H
8#define DM_SPACE_MAP_METADATA_H
9
10#include "dm-transaction-manager.h"
11
Mike Snitzer7d489352014-02-12 23:58:15 -050012#define DM_SM_METADATA_BLOCK_SIZE (4096 >> SECTOR_SHIFT)
13
14/*
15 * The metadata device is currently limited in size.
16 *
17 * We have one block of index, which can hold 255 index entries. Each
18 * index entry contains allocation info about ~16k metadata blocks.
19 */
20#define DM_SM_METADATA_MAX_BLOCKS (255 * ((1 << 14) - 64))
21#define DM_SM_METADATA_MAX_SECTORS (DM_SM_METADATA_MAX_BLOCKS * DM_SM_METADATA_BLOCK_SIZE)
22
Joe Thornber3241b1d2011-10-31 20:19:11 +000023/*
24 * Unfortunately we have to use two-phase construction due to the cycle
25 * between the tm and sm.
26 */
27struct dm_space_map *dm_sm_metadata_init(void);
28
29/*
30 * Create a fresh space map.
31 */
32int dm_sm_metadata_create(struct dm_space_map *sm,
33 struct dm_transaction_manager *tm,
34 dm_block_t nr_blocks,
35 dm_block_t superblock);
36
37/*
38 * Open from a previously-recorded root.
39 */
40int dm_sm_metadata_open(struct dm_space_map *sm,
41 struct dm_transaction_manager *tm,
42 void *root_le, size_t len);
43
44#endif /* DM_SPACE_MAP_METADATA_H */