1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Copyright (C) 2011 Red Hat, Inc.
5 * This file is released under the GPL.
8 #ifndef DM_SPACE_MAP_METADATA_H
9 #define DM_SPACE_MAP_METADATA_H
11 #include "dm-transaction-manager.h"
13 #define DM_SM_METADATA_BLOCK_SIZE (4096 >> SECTOR_SHIFT)
16 * The metadata device is currently limited in size.
18 * We have one block of index, which can hold 255 index entries. Each
19 * index entry contains allocation info about ~16k metadata blocks.
21 #define DM_SM_METADATA_MAX_BLOCKS (255 * ((1 << 14) - 64))
22 #define DM_SM_METADATA_MAX_SECTORS (DM_SM_METADATA_MAX_BLOCKS * DM_SM_METADATA_BLOCK_SIZE)
25 * Unfortunately we have to use two-phase construction due to the cycle
26 * between the tm and sm.
28 struct dm_space_map *dm_sm_metadata_init(void);
31 * Create a fresh space map.
33 int dm_sm_metadata_create(struct dm_space_map *sm,
34 struct dm_transaction_manager *tm,
36 dm_block_t superblock);
39 * Open from a previously-recorded root.
41 int dm_sm_metadata_open(struct dm_space_map *sm,
42 struct dm_transaction_manager *tm,
43 void *root_le, size_t len);
45 #endif /* DM_SPACE_MAP_METADATA_H */