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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 _LINUX_DM_SPACE_MAP_H9#define _LINUX_DM_SPACE_MAP_H10 11#include "dm-block-manager.h"12 13typedef void (*dm_sm_threshold_fn)(void *context);14 15/*16 * struct dm_space_map keeps a record of how many times each block in a device17 * is referenced. It needs to be fixed on disk as part of the transaction.18 */19struct dm_space_map {20 void (*destroy)(struct dm_space_map *sm);21 22 /*23 * You must commit before allocating the newly added space.24 */25 int (*extend)(struct dm_space_map *sm, dm_block_t extra_blocks);26 27 /*28 * Extensions do not appear in this count until after commit has29 * been called.30 */31 int (*get_nr_blocks)(struct dm_space_map *sm, dm_block_t *count);32 33 /*34 * Space maps must never allocate a block from the previous35 * transaction, in case we need to rollback. This complicates the36 * semantics of get_nr_free(), it should return the number of blocks37 * that are available for allocation _now_. For instance you may38 * have blocks with a zero reference count that will not be39 * available for allocation until after the next commit.40 */41 int (*get_nr_free)(struct dm_space_map *sm, dm_block_t *count);42 43 int (*get_count)(struct dm_space_map *sm, dm_block_t b, uint32_t *result);44 int (*count_is_more_than_one)(struct dm_space_map *sm, dm_block_t b,45 int *result);46 int (*set_count)(struct dm_space_map *sm, dm_block_t b, uint32_t count);47 48 int (*commit)(struct dm_space_map *sm);49 50 int (*inc_blocks)(struct dm_space_map *sm, dm_block_t b, dm_block_t e);51 int (*dec_blocks)(struct dm_space_map *sm, dm_block_t b, dm_block_t e);52 53 /*54 * new_block will increment the returned block.55 */56 int (*new_block)(struct dm_space_map *sm, dm_block_t *b);57 58 /*59 * The root contains all the information needed to fix the space map.60 * Generally this info is small, so squirrel it away in a disk block61 * along with other info.62 */63 int (*root_size)(struct dm_space_map *sm, size_t *result);64 int (*copy_root)(struct dm_space_map *sm, void *copy_to_here_le, size_t len);65 66 /*67 * You can register one threshold callback which is edge-triggered68 * when the free space in the space map drops below the threshold.69 */70 int (*register_threshold_callback)(struct dm_space_map *sm,71 dm_block_t threshold,72 dm_sm_threshold_fn fn,73 void *context);74};75 76/*----------------------------------------------------------------*/77 78static inline void dm_sm_destroy(struct dm_space_map *sm)79{80 if (sm)81 sm->destroy(sm);82}83 84static inline int dm_sm_extend(struct dm_space_map *sm, dm_block_t extra_blocks)85{86 return sm->extend(sm, extra_blocks);87}88 89static inline int dm_sm_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)90{91 return sm->get_nr_blocks(sm, count);92}93 94static inline int dm_sm_get_nr_free(struct dm_space_map *sm, dm_block_t *count)95{96 return sm->get_nr_free(sm, count);97}98 99static inline int dm_sm_get_count(struct dm_space_map *sm, dm_block_t b,100 uint32_t *result)101{102 return sm->get_count(sm, b, result);103}104 105static inline int dm_sm_count_is_more_than_one(struct dm_space_map *sm,106 dm_block_t b, int *result)107{108 return sm->count_is_more_than_one(sm, b, result);109}110 111static inline int dm_sm_set_count(struct dm_space_map *sm, dm_block_t b,112 uint32_t count)113{114 return sm->set_count(sm, b, count);115}116 117static inline int dm_sm_commit(struct dm_space_map *sm)118{119 return sm->commit(sm);120}121 122static inline int dm_sm_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)123{124 return sm->inc_blocks(sm, b, e);125}126 127static inline int dm_sm_inc_block(struct dm_space_map *sm, dm_block_t b)128{129 return dm_sm_inc_blocks(sm, b, b + 1);130}131 132static inline int dm_sm_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)133{134 return sm->dec_blocks(sm, b, e);135}136 137static inline int dm_sm_dec_block(struct dm_space_map *sm, dm_block_t b)138{139 return dm_sm_dec_blocks(sm, b, b + 1);140}141 142static inline int dm_sm_new_block(struct dm_space_map *sm, dm_block_t *b)143{144 return sm->new_block(sm, b);145}146 147static inline int dm_sm_root_size(struct dm_space_map *sm, size_t *result)148{149 return sm->root_size(sm, result);150}151 152static inline int dm_sm_copy_root(struct dm_space_map *sm, void *copy_to_here_le, size_t len)153{154 return sm->copy_root(sm, copy_to_here_le, len);155}156 157static inline int dm_sm_register_threshold_callback(struct dm_space_map *sm,158 dm_block_t threshold,159 dm_sm_threshold_fn fn,160 void *context)161{162 if (sm->register_threshold_callback)163 return sm->register_threshold_callback(sm, threshold, fn, context);164 165 return -EINVAL;166}167 168 169#endif /* _LINUX_DM_SPACE_MAP_H */170