1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2011 Red Hat, Inc. 4 * 5 * This file is released under the GPL. 6 */ 7 8 #ifndef DM_SPACE_MAP_METADATA_H 9 #define DM_SPACE_MAP_METADATA_H 10 11 #include "dm-transaction-manager.h" 12 13 #define DM_SM_METADATA_BLOCK_SIZE (4096 >> SECTOR_SHIFT) 14 15 /* 16 * The metadata device is currently limited in size. 17 * 18 * We have one block of index, which can hold 255 index entries. Each 19 * index entry contains allocation info about ~16k metadata blocks. 20 */ 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) 23 24 /* 25 * Unfortunately we have to use two-phase construction due to the cycle 26 * between the tm and sm. 27 */ 28 struct dm_space_map *dm_sm_metadata_init(void); 29 30 /* 31 * Create a fresh space map. 32 */ 33 int dm_sm_metadata_create(struct dm_space_map *sm, 34 struct dm_transaction_manager *tm, 35 dm_block_t nr_blocks, 36 dm_block_t superblock); 37 38 /* 39 * Open from a previously-recorded root. 40 */ 41 int dm_sm_metadata_open(struct dm_space_map *sm, 42 struct dm_transaction_manager *tm, 43 void *root_le, size_t len); 44 45 #endif /* DM_SPACE_MAP_METADATA_H */ 46