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10#ifndef _LINUX_DM_EXCEPTION_STORE
11#define _LINUX_DM_EXCEPTION_STORE
12
13#include <linux/blkdev.h>
14#include <linux/device-mapper.h>
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19
20typedef sector_t chunk_t;
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28
29struct dm_exception {
30 struct list_head hash_list;
31
32 chunk_t old_chunk;
33 chunk_t new_chunk;
34};
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39
40struct dm_exception_store;
41struct dm_exception_store_type {
42 const char *name;
43 struct module *module;
44
45 int (*ctr) (struct dm_exception_store *store, char *options);
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50 void (*dtr) (struct dm_exception_store *store);
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57 int (*read_metadata) (struct dm_exception_store *store,
58 int (*callback)(void *callback_context,
59 chunk_t old, chunk_t new),
60 void *callback_context);
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64
65 int (*prepare_exception) (struct dm_exception_store *store,
66 struct dm_exception *e);
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70
71 void (*commit_exception) (struct dm_exception_store *store,
72 struct dm_exception *e, int valid,
73 void (*callback) (void *, int success),
74 void *callback_context);
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84 int (*prepare_merge) (struct dm_exception_store *store,
85 chunk_t *last_old_chunk, chunk_t *last_new_chunk);
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91 int (*commit_merge) (struct dm_exception_store *store, int nr_merged);
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96 void (*drop_snapshot) (struct dm_exception_store *store);
97
98 unsigned (*status) (struct dm_exception_store *store,
99 status_type_t status, char *result,
100 unsigned maxlen);
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103
104
105 void (*usage) (struct dm_exception_store *store,
106 sector_t *total_sectors, sector_t *sectors_allocated,
107 sector_t *metadata_sectors);
108
109
110 struct list_head list;
111};
112
113struct dm_snapshot;
114
115struct dm_exception_store {
116 struct dm_exception_store_type *type;
117 struct dm_snapshot *snap;
118
119
120 unsigned chunk_size;
121 unsigned chunk_mask;
122 unsigned chunk_shift;
123
124 void *context;
125
126 bool userspace_supports_overflow;
127};
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131
132struct dm_dev *dm_snap_origin(struct dm_snapshot *snap);
133struct dm_dev *dm_snap_cow(struct dm_snapshot *snap);
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137
138# if defined(CONFIG_LBDAF) || (BITS_PER_LONG == 64)
139# define DM_CHUNK_CONSECUTIVE_BITS 8
140# define DM_CHUNK_NUMBER_BITS 56
141
142static inline chunk_t dm_chunk_number(chunk_t chunk)
143{
144 return chunk & (chunk_t)((1ULL << DM_CHUNK_NUMBER_BITS) - 1ULL);
145}
146
147static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e)
148{
149 return e->new_chunk >> DM_CHUNK_NUMBER_BITS;
150}
151
152static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e)
153{
154 e->new_chunk += (1ULL << DM_CHUNK_NUMBER_BITS);
155
156 BUG_ON(!dm_consecutive_chunk_count(e));
157}
158
159static inline void dm_consecutive_chunk_count_dec(struct dm_exception *e)
160{
161 BUG_ON(!dm_consecutive_chunk_count(e));
162
163 e->new_chunk -= (1ULL << DM_CHUNK_NUMBER_BITS);
164}
165
166# else
167# define DM_CHUNK_CONSECUTIVE_BITS 0
168
169static inline chunk_t dm_chunk_number(chunk_t chunk)
170{
171 return chunk;
172}
173
174static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e)
175{
176 return 0;
177}
178
179static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e)
180{
181}
182
183static inline void dm_consecutive_chunk_count_dec(struct dm_exception *e)
184{
185}
186
187# endif
188
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191
192static inline sector_t get_dev_size(struct block_device *bdev)
193{
194 return i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
195}
196
197static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
198 sector_t sector)
199{
200 return sector >> store->chunk_shift;
201}
202
203int dm_exception_store_type_register(struct dm_exception_store_type *type);
204int dm_exception_store_type_unregister(struct dm_exception_store_type *type);
205
206int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
207 unsigned chunk_size,
208 char **error);
209
210int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
211 struct dm_snapshot *snap,
212 unsigned *args_used,
213 struct dm_exception_store **store);
214void dm_exception_store_destroy(struct dm_exception_store *store);
215
216int dm_exception_store_init(void);
217void dm_exception_store_exit(void);
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221
222int dm_persistent_snapshot_init(void);
223void dm_persistent_snapshot_exit(void);
224
225int dm_transient_snapshot_init(void);
226void dm_transient_snapshot_exit(void);
227
228#endif
229