1 /*
2 * Copyright (C) 2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7 #ifndef _LINUX_DM_SPACE_MAP_H
8 #define _LINUX_DM_SPACE_MAP_H
9
10 #include "dm-block-manager.h"
11
12 /*
13 * struct dm_space_map keeps a record of how many times each block in a device
14 * is referenced. It needs to be fixed on disk as part of the transaction.
15 */
16 struct dm_space_map {
17 void (*destroy)(struct dm_space_map *sm);
18
19 /*
20 * You must commit before allocating the newly added space.
21 */
22 int (*extend)(struct dm_space_map *sm, dm_block_t extra_blocks);
23
24 /*
25 * Extensions do not appear in this count until after commit has
26 * been called.
27 */
28 int (*get_nr_blocks)(struct dm_space_map *sm, dm_block_t *count);
29
30 /*
31 * Space maps must never allocate a block from the previous
32 * transaction, in case we need to rollback. This complicates the
33 * semantics of get_nr_free(), it should return the number of blocks
34 * that are available for allocation _now_. For instance you may
35 * have blocks with a zero reference count that will not be
36 * available for allocation until after the next commit.
37 */
38 int (*get_nr_free)(struct dm_space_map *sm, dm_block_t *count);
39
40 int (*get_count)(struct dm_space_map *sm, dm_block_t b, uint32_t *result);
41 int (*count_is_more_than_one)(struct dm_space_map *sm, dm_block_t b,
42 int *result);
43 int (*set_count)(struct dm_space_map *sm, dm_block_t b, uint32_t count);
44
45 int (*commit)(struct dm_space_map *sm);
46
47 int (*inc_block)(struct dm_space_map *sm, dm_block_t b);
48 int (*dec_block)(struct dm_space_map *sm, dm_block_t b);
49
50 /*
51 * new_block will increment the returned block.
52 */
53 int (*new_block)(struct dm_space_map *sm, dm_block_t *b);
54
55 /*
56 * The root contains all the information needed to fix the space map.
57 * Generally this info is small, so squirrel it away in a disk block
58 * along with other info.
59 */
60 int (*root_size)(struct dm_space_map *sm, size_t *result);
61 int (*copy_root)(struct dm_space_map *sm, void *copy_to_here_le, size_t len);
62 };
63
64 /*----------------------------------------------------------------*/
65
dm_sm_destroy(struct dm_space_map * sm)66 static inline void dm_sm_destroy(struct dm_space_map *sm)
67 {
68 sm->destroy(sm);
69 }
70
dm_sm_extend(struct dm_space_map * sm,dm_block_t extra_blocks)71 static inline int dm_sm_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
72 {
73 return sm->extend(sm, extra_blocks);
74 }
75
dm_sm_get_nr_blocks(struct dm_space_map * sm,dm_block_t * count)76 static inline int dm_sm_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
77 {
78 return sm->get_nr_blocks(sm, count);
79 }
80
dm_sm_get_nr_free(struct dm_space_map * sm,dm_block_t * count)81 static inline int dm_sm_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
82 {
83 return sm->get_nr_free(sm, count);
84 }
85
dm_sm_get_count(struct dm_space_map * sm,dm_block_t b,uint32_t * result)86 static inline int dm_sm_get_count(struct dm_space_map *sm, dm_block_t b,
87 uint32_t *result)
88 {
89 return sm->get_count(sm, b, result);
90 }
91
dm_sm_count_is_more_than_one(struct dm_space_map * sm,dm_block_t b,int * result)92 static inline int dm_sm_count_is_more_than_one(struct dm_space_map *sm,
93 dm_block_t b, int *result)
94 {
95 return sm->count_is_more_than_one(sm, b, result);
96 }
97
dm_sm_set_count(struct dm_space_map * sm,dm_block_t b,uint32_t count)98 static inline int dm_sm_set_count(struct dm_space_map *sm, dm_block_t b,
99 uint32_t count)
100 {
101 return sm->set_count(sm, b, count);
102 }
103
dm_sm_commit(struct dm_space_map * sm)104 static inline int dm_sm_commit(struct dm_space_map *sm)
105 {
106 return sm->commit(sm);
107 }
108
dm_sm_inc_block(struct dm_space_map * sm,dm_block_t b)109 static inline int dm_sm_inc_block(struct dm_space_map *sm, dm_block_t b)
110 {
111 return sm->inc_block(sm, b);
112 }
113
dm_sm_dec_block(struct dm_space_map * sm,dm_block_t b)114 static inline int dm_sm_dec_block(struct dm_space_map *sm, dm_block_t b)
115 {
116 return sm->dec_block(sm, b);
117 }
118
dm_sm_new_block(struct dm_space_map * sm,dm_block_t * b)119 static inline int dm_sm_new_block(struct dm_space_map *sm, dm_block_t *b)
120 {
121 return sm->new_block(sm, b);
122 }
123
dm_sm_root_size(struct dm_space_map * sm,size_t * result)124 static inline int dm_sm_root_size(struct dm_space_map *sm, size_t *result)
125 {
126 return sm->root_size(sm, result);
127 }
128
dm_sm_copy_root(struct dm_space_map * sm,void * copy_to_here_le,size_t len)129 static inline int dm_sm_copy_root(struct dm_space_map *sm, void *copy_to_here_le, size_t len)
130 {
131 return sm->copy_root(sm, copy_to_here_le, len);
132 }
133
134 #endif /* _LINUX_DM_SPACE_MAP_H */
135