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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001 Sistina Software (UK) Limited. | |
0da336e5 | 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
1da177e4 LT |
4 | * |
5 | * This file is released under the LGPL. | |
6 | */ | |
7 | ||
8 | #ifndef _LINUX_DEVICE_MAPPER_H | |
9 | #define _LINUX_DEVICE_MAPPER_H | |
10 | ||
416cd17b | 11 | #include <linux/bio.h> |
f6fccb12 | 12 | #include <linux/blkdev.h> |
416cd17b | 13 | |
1da177e4 LT |
14 | struct dm_target; |
15 | struct dm_table; | |
17b2f66f | 16 | struct mapped_device; |
f6fccb12 | 17 | struct bio_vec; |
1da177e4 LT |
18 | |
19 | typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; | |
20 | ||
21 | union map_info { | |
22 | void *ptr; | |
23 | unsigned long long ll; | |
24 | }; | |
25 | ||
26 | /* | |
27 | * In the constructor the target parameter will already have the | |
28 | * table, type, begin and len fields filled in. | |
29 | */ | |
30 | typedef int (*dm_ctr_fn) (struct dm_target *target, | |
31 | unsigned int argc, char **argv); | |
32 | ||
33 | /* | |
34 | * The destructor doesn't need to free the dm_target, just | |
35 | * anything hidden ti->private. | |
36 | */ | |
37 | typedef void (*dm_dtr_fn) (struct dm_target *ti); | |
38 | ||
39 | /* | |
40 | * The map function must return: | |
41 | * < 0: error | |
42 | * = 0: The target will handle the io by resubmitting it later | |
45cbcd79 | 43 | * = 1: simple remap complete |
2e93ccc1 | 44 | * = 2: The target wants to push back the io |
1da177e4 LT |
45 | */ |
46 | typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, | |
47 | union map_info *map_context); | |
7d76345d KU |
48 | typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, |
49 | union map_info *map_context); | |
1da177e4 LT |
50 | |
51 | /* | |
52 | * Returns: | |
53 | * < 0 : error (currently ignored) | |
54 | * 0 : ended successfully | |
55 | * 1 : for some reason the io has still not completed (eg, | |
56 | * multipath target might want to requeue a failed io). | |
2e93ccc1 | 57 | * 2 : The target wants to push back the io |
1da177e4 LT |
58 | */ |
59 | typedef int (*dm_endio_fn) (struct dm_target *ti, | |
60 | struct bio *bio, int error, | |
61 | union map_info *map_context); | |
7d76345d KU |
62 | typedef int (*dm_request_endio_fn) (struct dm_target *ti, |
63 | struct request *clone, int error, | |
64 | union map_info *map_context); | |
1da177e4 | 65 | |
999d8168 | 66 | typedef void (*dm_flush_fn) (struct dm_target *ti); |
1da177e4 LT |
67 | typedef void (*dm_presuspend_fn) (struct dm_target *ti); |
68 | typedef void (*dm_postsuspend_fn) (struct dm_target *ti); | |
8757b776 | 69 | typedef int (*dm_preresume_fn) (struct dm_target *ti); |
1da177e4 LT |
70 | typedef void (*dm_resume_fn) (struct dm_target *ti); |
71 | ||
72 | typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, | |
73 | char *result, unsigned int maxlen); | |
74 | ||
75 | typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); | |
76 | ||
647b3d00 | 77 | typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd, |
aa129a22 MB |
78 | unsigned long arg); |
79 | ||
f6fccb12 MB |
80 | typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm, |
81 | struct bio_vec *biovec, int max_size); | |
82 | ||
7d76345d KU |
83 | /* |
84 | * Returns: | |
85 | * 0: The target can handle the next I/O immediately. | |
86 | * 1: The target can't handle the next I/O immediately. | |
87 | */ | |
88 | typedef int (*dm_busy_fn) (struct dm_target *ti); | |
89 | ||
1da177e4 LT |
90 | void dm_error(const char *message); |
91 | ||
3cb40214 BR |
92 | /* |
93 | * Combine device limits. | |
94 | */ | |
95 | void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev); | |
96 | ||
82b1519b MP |
97 | struct dm_dev { |
98 | struct block_device *bdev; | |
aeb5d727 | 99 | fmode_t mode; |
82b1519b MP |
100 | char name[16]; |
101 | }; | |
102 | ||
1da177e4 LT |
103 | /* |
104 | * Constructors should call these functions to ensure destination devices | |
105 | * are opened/closed correctly. | |
106 | * FIXME: too many arguments. | |
107 | */ | |
108 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, | |
aeb5d727 | 109 | sector_t len, fmode_t mode, struct dm_dev **result); |
1da177e4 LT |
110 | void dm_put_device(struct dm_target *ti, struct dm_dev *d); |
111 | ||
112 | /* | |
113 | * Information about a target type | |
114 | */ | |
115 | struct target_type { | |
116 | const char *name; | |
117 | struct module *module; | |
17b2f66f | 118 | unsigned version[3]; |
1da177e4 LT |
119 | dm_ctr_fn ctr; |
120 | dm_dtr_fn dtr; | |
121 | dm_map_fn map; | |
7d76345d | 122 | dm_map_request_fn map_rq; |
1da177e4 | 123 | dm_endio_fn end_io; |
7d76345d | 124 | dm_request_endio_fn rq_end_io; |
999d8168 | 125 | dm_flush_fn flush; |
1da177e4 LT |
126 | dm_presuspend_fn presuspend; |
127 | dm_postsuspend_fn postsuspend; | |
8757b776 | 128 | dm_preresume_fn preresume; |
1da177e4 LT |
129 | dm_resume_fn resume; |
130 | dm_status_fn status; | |
131 | dm_message_fn message; | |
aa129a22 | 132 | dm_ioctl_fn ioctl; |
f6fccb12 | 133 | dm_merge_fn merge; |
7d76345d | 134 | dm_busy_fn busy; |
1da177e4 LT |
135 | }; |
136 | ||
137 | struct io_restrictions { | |
4f41b09f VA |
138 | unsigned long bounce_pfn; |
139 | unsigned long seg_boundary_mask; | |
140 | unsigned max_hw_sectors; | |
141 | unsigned max_sectors; | |
142 | unsigned max_segment_size; | |
143 | unsigned short hardsect_size; | |
144 | unsigned short max_hw_segments; | |
145 | unsigned short max_phys_segments; | |
146 | unsigned char no_cluster; /* inverted so that 0 is default */ | |
1da177e4 LT |
147 | }; |
148 | ||
149 | struct dm_target { | |
150 | struct dm_table *table; | |
151 | struct target_type *type; | |
152 | ||
153 | /* target limits */ | |
154 | sector_t begin; | |
155 | sector_t len; | |
156 | ||
157 | /* FIXME: turn this into a mask, and merge with io_restrictions */ | |
158 | /* Always a power of 2 */ | |
159 | sector_t split_io; | |
160 | ||
161 | /* | |
162 | * These are automatically filled in by | |
163 | * dm_table_get_device. | |
164 | */ | |
165 | struct io_restrictions limits; | |
166 | ||
167 | /* target specific data */ | |
168 | void *private; | |
169 | ||
170 | /* Used to provide an error string from the ctr */ | |
171 | char *error; | |
172 | }; | |
173 | ||
174 | int dm_register_target(struct target_type *t); | |
10d3bd09 | 175 | void dm_unregister_target(struct target_type *t); |
17b2f66f AK |
176 | |
177 | /*----------------------------------------------------------------- | |
178 | * Functions for creating and manipulating mapped devices. | |
179 | * Drop the reference with dm_put when you finish with the object. | |
180 | *---------------------------------------------------------------*/ | |
181 | ||
182 | /* | |
183 | * DM_ANY_MINOR chooses the next available minor number. | |
184 | */ | |
185 | #define DM_ANY_MINOR (-1) | |
186 | int dm_create(int minor, struct mapped_device **md); | |
187 | ||
188 | /* | |
189 | * Reference counting for md. | |
190 | */ | |
191 | struct mapped_device *dm_get_md(dev_t dev); | |
192 | void dm_get(struct mapped_device *md); | |
193 | void dm_put(struct mapped_device *md); | |
194 | ||
195 | /* | |
196 | * An arbitrary pointer may be stored alongside a mapped device. | |
197 | */ | |
198 | void dm_set_mdptr(struct mapped_device *md, void *ptr); | |
199 | void *dm_get_mdptr(struct mapped_device *md); | |
200 | ||
201 | /* | |
202 | * A device can still be used while suspended, but I/O is deferred. | |
203 | */ | |
a3d77d35 | 204 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags); |
17b2f66f AK |
205 | int dm_resume(struct mapped_device *md); |
206 | ||
207 | /* | |
208 | * Event functions. | |
209 | */ | |
210 | uint32_t dm_get_event_nr(struct mapped_device *md); | |
211 | int dm_wait_event(struct mapped_device *md, int event_nr); | |
7a8c3d3b MA |
212 | uint32_t dm_next_uevent_seq(struct mapped_device *md); |
213 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist); | |
17b2f66f AK |
214 | |
215 | /* | |
216 | * Info functions. | |
217 | */ | |
72d94861 | 218 | const char *dm_device_name(struct mapped_device *md); |
96a1f7db | 219 | int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid); |
17b2f66f AK |
220 | struct gendisk *dm_disk(struct mapped_device *md); |
221 | int dm_suspended(struct mapped_device *md); | |
2e93ccc1 | 222 | int dm_noflush_suspending(struct dm_target *ti); |
89343da0 | 223 | union map_info *dm_get_mapinfo(struct bio *bio); |
17b2f66f AK |
224 | |
225 | /* | |
226 | * Geometry functions. | |
227 | */ | |
228 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
229 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
230 | ||
231 | ||
232 | /*----------------------------------------------------------------- | |
233 | * Functions for manipulating device-mapper tables. | |
234 | *---------------------------------------------------------------*/ | |
235 | ||
236 | /* | |
237 | * First create an empty table. | |
238 | */ | |
aeb5d727 | 239 | int dm_table_create(struct dm_table **result, fmode_t mode, |
17b2f66f AK |
240 | unsigned num_targets, struct mapped_device *md); |
241 | ||
242 | /* | |
243 | * Then call this once for each target. | |
244 | */ | |
245 | int dm_table_add_target(struct dm_table *t, const char *type, | |
246 | sector_t start, sector_t len, char *params); | |
247 | ||
248 | /* | |
249 | * Finally call this to make the table ready for use. | |
250 | */ | |
251 | int dm_table_complete(struct dm_table *t); | |
252 | ||
ea0ec640 MP |
253 | /* |
254 | * Unplug all devices in a table. | |
255 | */ | |
256 | void dm_table_unplug_all(struct dm_table *t); | |
257 | ||
17b2f66f AK |
258 | /* |
259 | * Table reference counting. | |
260 | */ | |
261 | struct dm_table *dm_get_table(struct mapped_device *md); | |
262 | void dm_table_get(struct dm_table *t); | |
263 | void dm_table_put(struct dm_table *t); | |
264 | ||
265 | /* | |
266 | * Queries | |
267 | */ | |
268 | sector_t dm_table_get_size(struct dm_table *t); | |
269 | unsigned int dm_table_get_num_targets(struct dm_table *t); | |
aeb5d727 | 270 | fmode_t dm_table_get_mode(struct dm_table *t); |
17b2f66f AK |
271 | struct mapped_device *dm_table_get_md(struct dm_table *t); |
272 | ||
273 | /* | |
274 | * Trigger an event. | |
275 | */ | |
276 | void dm_table_event(struct dm_table *t); | |
277 | ||
278 | /* | |
279 | * The device must be suspended before calling this method. | |
280 | */ | |
281 | int dm_swap_table(struct mapped_device *md, struct dm_table *t); | |
282 | ||
54160904 MP |
283 | /* |
284 | * A wrapper around vmalloc. | |
285 | */ | |
286 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); | |
287 | ||
0da336e5 AK |
288 | /*----------------------------------------------------------------- |
289 | * Macros. | |
290 | *---------------------------------------------------------------*/ | |
291 | #define DM_NAME "device-mapper" | |
292 | ||
10d3bd09 MP |
293 | #define DMCRIT(f, arg...) \ |
294 | printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
295 | ||
0da336e5 AK |
296 | #define DMERR(f, arg...) \ |
297 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
298 | #define DMERR_LIMIT(f, arg...) \ | |
299 | do { \ | |
300 | if (printk_ratelimit()) \ | |
301 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \ | |
302 | f "\n", ## arg); \ | |
303 | } while (0) | |
304 | ||
305 | #define DMWARN(f, arg...) \ | |
306 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
307 | #define DMWARN_LIMIT(f, arg...) \ | |
308 | do { \ | |
309 | if (printk_ratelimit()) \ | |
310 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \ | |
311 | f "\n", ## arg); \ | |
312 | } while (0) | |
313 | ||
314 | #define DMINFO(f, arg...) \ | |
315 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
316 | #define DMINFO_LIMIT(f, arg...) \ | |
317 | do { \ | |
318 | if (printk_ratelimit()) \ | |
319 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \ | |
320 | "\n", ## arg); \ | |
321 | } while (0) | |
322 | ||
323 | #ifdef CONFIG_DM_DEBUG | |
324 | # define DMDEBUG(f, arg...) \ | |
325 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg) | |
326 | # define DMDEBUG_LIMIT(f, arg...) \ | |
327 | do { \ | |
328 | if (printk_ratelimit()) \ | |
329 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \ | |
330 | "\n", ## arg); \ | |
331 | } while (0) | |
332 | #else | |
333 | # define DMDEBUG(f, arg...) do {} while (0) | |
334 | # define DMDEBUG_LIMIT(f, arg...) do {} while (0) | |
335 | #endif | |
336 | ||
337 | #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ | |
338 | 0 : scnprintf(result + sz, maxlen - sz, x)) | |
339 | ||
340 | #define SECTOR_SHIFT 9 | |
341 | ||
342 | /* | |
343 | * Definitions of return values from target end_io function. | |
344 | */ | |
345 | #define DM_ENDIO_INCOMPLETE 1 | |
346 | #define DM_ENDIO_REQUEUE 2 | |
347 | ||
348 | /* | |
349 | * Definitions of return values from target map function. | |
350 | */ | |
351 | #define DM_MAPIO_SUBMITTED 0 | |
352 | #define DM_MAPIO_REMAPPED 1 | |
353 | #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE | |
354 | ||
355 | /* | |
356 | * Ceiling(n / sz) | |
357 | */ | |
358 | #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz)) | |
359 | ||
360 | #define dm_sector_div_up(n, sz) ( \ | |
361 | { \ | |
362 | sector_t _r = ((n) + (sz) - 1); \ | |
363 | sector_div(_r, (sz)); \ | |
364 | _r; \ | |
365 | } \ | |
366 | ) | |
367 | ||
368 | /* | |
369 | * ceiling(n / size) * size | |
370 | */ | |
371 | #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz)) | |
372 | ||
d63a5ce3 MP |
373 | #define dm_array_too_big(fixed, obj, num) \ |
374 | ((num) > (UINT_MAX - (fixed)) / (obj)) | |
375 | ||
0da336e5 AK |
376 | static inline sector_t to_sector(unsigned long n) |
377 | { | |
378 | return (n >> SECTOR_SHIFT); | |
379 | } | |
380 | ||
381 | static inline unsigned long to_bytes(sector_t n) | |
382 | { | |
383 | return (n << SECTOR_SHIFT); | |
384 | } | |
385 | ||
17b2f66f | 386 | #endif /* _LINUX_DEVICE_MAPPER_H */ |