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Commit | Line | Data |
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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> |
71a16736 | 13 | #include <linux/ratelimit.h> |
416cd17b | 14 | |
af4874e0 | 15 | struct dm_dev; |
1da177e4 LT |
16 | struct dm_target; |
17 | struct dm_table; | |
17b2f66f | 18 | struct mapped_device; |
f6fccb12 | 19 | struct bio_vec; |
1da177e4 LT |
20 | |
21 | typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; | |
22 | ||
23 | union map_info { | |
24 | void *ptr; | |
25 | unsigned long long ll; | |
57cba5d3 | 26 | unsigned target_request_nr; |
1da177e4 LT |
27 | }; |
28 | ||
29 | /* | |
30 | * In the constructor the target parameter will already have the | |
31 | * table, type, begin and len fields filled in. | |
32 | */ | |
33 | typedef int (*dm_ctr_fn) (struct dm_target *target, | |
34 | unsigned int argc, char **argv); | |
35 | ||
36 | /* | |
37 | * The destructor doesn't need to free the dm_target, just | |
38 | * anything hidden ti->private. | |
39 | */ | |
40 | typedef void (*dm_dtr_fn) (struct dm_target *ti); | |
41 | ||
42 | /* | |
43 | * The map function must return: | |
44 | * < 0: error | |
45 | * = 0: The target will handle the io by resubmitting it later | |
45cbcd79 | 46 | * = 1: simple remap complete |
2e93ccc1 | 47 | * = 2: The target wants to push back the io |
1da177e4 LT |
48 | */ |
49 | typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, | |
50 | union map_info *map_context); | |
7d76345d KU |
51 | typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, |
52 | union map_info *map_context); | |
1da177e4 LT |
53 | |
54 | /* | |
55 | * Returns: | |
56 | * < 0 : error (currently ignored) | |
57 | * 0 : ended successfully | |
58 | * 1 : for some reason the io has still not completed (eg, | |
59 | * multipath target might want to requeue a failed io). | |
2e93ccc1 | 60 | * 2 : The target wants to push back the io |
1da177e4 LT |
61 | */ |
62 | typedef int (*dm_endio_fn) (struct dm_target *ti, | |
63 | struct bio *bio, int error, | |
64 | union map_info *map_context); | |
7d76345d KU |
65 | typedef int (*dm_request_endio_fn) (struct dm_target *ti, |
66 | struct request *clone, int error, | |
67 | union map_info *map_context); | |
1da177e4 | 68 | |
999d8168 | 69 | typedef void (*dm_flush_fn) (struct dm_target *ti); |
1da177e4 LT |
70 | typedef void (*dm_presuspend_fn) (struct dm_target *ti); |
71 | typedef void (*dm_postsuspend_fn) (struct dm_target *ti); | |
8757b776 | 72 | typedef int (*dm_preresume_fn) (struct dm_target *ti); |
1da177e4 LT |
73 | typedef void (*dm_resume_fn) (struct dm_target *ti); |
74 | ||
75 | typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, | |
76 | char *result, unsigned int maxlen); | |
77 | ||
78 | typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); | |
79 | ||
647b3d00 | 80 | typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd, |
aa129a22 MB |
81 | unsigned long arg); |
82 | ||
f6fccb12 MB |
83 | typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm, |
84 | struct bio_vec *biovec, int max_size); | |
85 | ||
af4874e0 MS |
86 | typedef int (*iterate_devices_callout_fn) (struct dm_target *ti, |
87 | struct dm_dev *dev, | |
5dea271b | 88 | sector_t start, sector_t len, |
af4874e0 MS |
89 | void *data); |
90 | ||
91 | typedef int (*dm_iterate_devices_fn) (struct dm_target *ti, | |
92 | iterate_devices_callout_fn fn, | |
93 | void *data); | |
94 | ||
40bea431 MS |
95 | typedef void (*dm_io_hints_fn) (struct dm_target *ti, |
96 | struct queue_limits *limits); | |
97 | ||
7d76345d KU |
98 | /* |
99 | * Returns: | |
100 | * 0: The target can handle the next I/O immediately. | |
101 | * 1: The target can't handle the next I/O immediately. | |
102 | */ | |
103 | typedef int (*dm_busy_fn) (struct dm_target *ti); | |
104 | ||
1da177e4 LT |
105 | void dm_error(const char *message); |
106 | ||
3cb40214 BR |
107 | /* |
108 | * Combine device limits. | |
109 | */ | |
754c5fc7 | 110 | int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev, |
5dea271b | 111 | sector_t start, sector_t len, void *data); |
3cb40214 | 112 | |
82b1519b MP |
113 | struct dm_dev { |
114 | struct block_device *bdev; | |
aeb5d727 | 115 | fmode_t mode; |
82b1519b MP |
116 | char name[16]; |
117 | }; | |
118 | ||
1da177e4 LT |
119 | /* |
120 | * Constructors should call these functions to ensure destination devices | |
121 | * are opened/closed correctly. | |
1da177e4 | 122 | */ |
8215d6ec NK |
123 | int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, |
124 | struct dm_dev **result); | |
1da177e4 LT |
125 | void dm_put_device(struct dm_target *ti, struct dm_dev *d); |
126 | ||
127 | /* | |
128 | * Information about a target type | |
129 | */ | |
ab4c1424 AK |
130 | |
131 | /* | |
132 | * Target features | |
133 | */ | |
ab4c1424 | 134 | |
1da177e4 | 135 | struct target_type { |
ab4c1424 | 136 | uint64_t features; |
1da177e4 LT |
137 | const char *name; |
138 | struct module *module; | |
17b2f66f | 139 | unsigned version[3]; |
1da177e4 LT |
140 | dm_ctr_fn ctr; |
141 | dm_dtr_fn dtr; | |
142 | dm_map_fn map; | |
7d76345d | 143 | dm_map_request_fn map_rq; |
1da177e4 | 144 | dm_endio_fn end_io; |
7d76345d | 145 | dm_request_endio_fn rq_end_io; |
999d8168 | 146 | dm_flush_fn flush; |
1da177e4 LT |
147 | dm_presuspend_fn presuspend; |
148 | dm_postsuspend_fn postsuspend; | |
8757b776 | 149 | dm_preresume_fn preresume; |
1da177e4 LT |
150 | dm_resume_fn resume; |
151 | dm_status_fn status; | |
152 | dm_message_fn message; | |
aa129a22 | 153 | dm_ioctl_fn ioctl; |
f6fccb12 | 154 | dm_merge_fn merge; |
7d76345d | 155 | dm_busy_fn busy; |
af4874e0 | 156 | dm_iterate_devices_fn iterate_devices; |
40bea431 | 157 | dm_io_hints_fn io_hints; |
45194e4f CR |
158 | |
159 | /* For internal device-mapper use. */ | |
160 | struct list_head list; | |
1da177e4 LT |
161 | }; |
162 | ||
1da177e4 LT |
163 | struct dm_target { |
164 | struct dm_table *table; | |
165 | struct target_type *type; | |
166 | ||
167 | /* target limits */ | |
168 | sector_t begin; | |
169 | sector_t len; | |
170 | ||
1da177e4 LT |
171 | /* Always a power of 2 */ |
172 | sector_t split_io; | |
173 | ||
f9ab94ce MP |
174 | /* |
175 | * A number of zero-length barrier requests that will be submitted | |
176 | * to the target for the purpose of flushing cache. | |
177 | * | |
57cba5d3 | 178 | * The request number will be placed in union map_info->target_request_nr. |
f9ab94ce MP |
179 | * It is a responsibility of the target driver to remap these requests |
180 | * to the real underlying devices. | |
181 | */ | |
182 | unsigned num_flush_requests; | |
183 | ||
5ae89a87 MS |
184 | /* |
185 | * The number of discard requests that will be submitted to the | |
186 | * target. map_info->request_nr is used just like num_flush_requests. | |
187 | */ | |
188 | unsigned num_discard_requests; | |
189 | ||
1da177e4 LT |
190 | /* target specific data */ |
191 | void *private; | |
192 | ||
193 | /* Used to provide an error string from the ctr */ | |
194 | char *error; | |
4c259327 MS |
195 | |
196 | /* | |
197 | * Set if this target needs to receive discards regardless of | |
198 | * whether or not its underlying devices have support. | |
199 | */ | |
200 | unsigned discards_supported:1; | |
983c7db3 MB |
201 | |
202 | /* | |
203 | * Set if this target does not return zeroes on discarded blocks. | |
204 | */ | |
205 | unsigned discard_zeroes_data_unsupported:1; | |
1da177e4 LT |
206 | }; |
207 | ||
9d357b07 N |
208 | /* Each target can link one of these into the table */ |
209 | struct dm_target_callbacks { | |
210 | struct list_head list; | |
211 | int (*congested_fn) (struct dm_target_callbacks *, int); | |
212 | }; | |
213 | ||
1da177e4 | 214 | int dm_register_target(struct target_type *t); |
10d3bd09 | 215 | void dm_unregister_target(struct target_type *t); |
17b2f66f | 216 | |
498f0103 MS |
217 | /* |
218 | * Target argument parsing. | |
219 | */ | |
220 | struct dm_arg_set { | |
221 | unsigned argc; | |
222 | char **argv; | |
223 | }; | |
224 | ||
225 | /* | |
226 | * The minimum and maximum value of a numeric argument, together with | |
227 | * the error message to use if the number is found to be outside that range. | |
228 | */ | |
229 | struct dm_arg { | |
230 | unsigned min; | |
231 | unsigned max; | |
232 | char *error; | |
233 | }; | |
234 | ||
235 | /* | |
236 | * Validate the next argument, either returning it as *value or, if invalid, | |
237 | * returning -EINVAL and setting *error. | |
238 | */ | |
239 | int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set, | |
240 | unsigned *value, char **error); | |
241 | ||
242 | /* | |
243 | * Process the next argument as the start of a group containing between | |
244 | * arg->min and arg->max further arguments. Either return the size as | |
245 | * *num_args or, if invalid, return -EINVAL and set *error. | |
246 | */ | |
247 | int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set, | |
248 | unsigned *num_args, char **error); | |
249 | ||
250 | /* | |
251 | * Return the current argument and shift to the next. | |
252 | */ | |
253 | const char *dm_shift_arg(struct dm_arg_set *as); | |
254 | ||
255 | /* | |
256 | * Move through num_args arguments. | |
257 | */ | |
258 | void dm_consume_args(struct dm_arg_set *as, unsigned num_args); | |
259 | ||
17b2f66f AK |
260 | /*----------------------------------------------------------------- |
261 | * Functions for creating and manipulating mapped devices. | |
262 | * Drop the reference with dm_put when you finish with the object. | |
263 | *---------------------------------------------------------------*/ | |
264 | ||
265 | /* | |
266 | * DM_ANY_MINOR chooses the next available minor number. | |
267 | */ | |
268 | #define DM_ANY_MINOR (-1) | |
269 | int dm_create(int minor, struct mapped_device **md); | |
270 | ||
271 | /* | |
272 | * Reference counting for md. | |
273 | */ | |
274 | struct mapped_device *dm_get_md(dev_t dev); | |
275 | void dm_get(struct mapped_device *md); | |
276 | void dm_put(struct mapped_device *md); | |
277 | ||
278 | /* | |
279 | * An arbitrary pointer may be stored alongside a mapped device. | |
280 | */ | |
281 | void dm_set_mdptr(struct mapped_device *md, void *ptr); | |
282 | void *dm_get_mdptr(struct mapped_device *md); | |
283 | ||
284 | /* | |
285 | * A device can still be used while suspended, but I/O is deferred. | |
286 | */ | |
a3d77d35 | 287 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags); |
17b2f66f AK |
288 | int dm_resume(struct mapped_device *md); |
289 | ||
290 | /* | |
291 | * Event functions. | |
292 | */ | |
293 | uint32_t dm_get_event_nr(struct mapped_device *md); | |
294 | int dm_wait_event(struct mapped_device *md, int event_nr); | |
7a8c3d3b MA |
295 | uint32_t dm_next_uevent_seq(struct mapped_device *md); |
296 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist); | |
17b2f66f AK |
297 | |
298 | /* | |
299 | * Info functions. | |
300 | */ | |
72d94861 | 301 | const char *dm_device_name(struct mapped_device *md); |
96a1f7db | 302 | int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid); |
17b2f66f | 303 | struct gendisk *dm_disk(struct mapped_device *md); |
64dbce58 | 304 | int dm_suspended(struct dm_target *ti); |
2e93ccc1 | 305 | int dm_noflush_suspending(struct dm_target *ti); |
89343da0 | 306 | union map_info *dm_get_mapinfo(struct bio *bio); |
cec47e3d | 307 | union map_info *dm_get_rq_mapinfo(struct request *rq); |
17b2f66f AK |
308 | |
309 | /* | |
310 | * Geometry functions. | |
311 | */ | |
312 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
313 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
314 | ||
315 | ||
316 | /*----------------------------------------------------------------- | |
317 | * Functions for manipulating device-mapper tables. | |
318 | *---------------------------------------------------------------*/ | |
319 | ||
320 | /* | |
321 | * First create an empty table. | |
322 | */ | |
aeb5d727 | 323 | int dm_table_create(struct dm_table **result, fmode_t mode, |
17b2f66f AK |
324 | unsigned num_targets, struct mapped_device *md); |
325 | ||
326 | /* | |
327 | * Then call this once for each target. | |
328 | */ | |
329 | int dm_table_add_target(struct dm_table *t, const char *type, | |
330 | sector_t start, sector_t len, char *params); | |
331 | ||
9d357b07 N |
332 | /* |
333 | * Target_ctr should call this if it needs to add any callbacks. | |
334 | */ | |
335 | void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb); | |
336 | ||
17b2f66f AK |
337 | /* |
338 | * Finally call this to make the table ready for use. | |
339 | */ | |
340 | int dm_table_complete(struct dm_table *t); | |
341 | ||
342 | /* | |
343 | * Table reference counting. | |
344 | */ | |
7c666411 | 345 | struct dm_table *dm_get_live_table(struct mapped_device *md); |
17b2f66f AK |
346 | void dm_table_get(struct dm_table *t); |
347 | void dm_table_put(struct dm_table *t); | |
348 | ||
349 | /* | |
350 | * Queries | |
351 | */ | |
352 | sector_t dm_table_get_size(struct dm_table *t); | |
353 | unsigned int dm_table_get_num_targets(struct dm_table *t); | |
aeb5d727 | 354 | fmode_t dm_table_get_mode(struct dm_table *t); |
17b2f66f AK |
355 | struct mapped_device *dm_table_get_md(struct dm_table *t); |
356 | ||
357 | /* | |
358 | * Trigger an event. | |
359 | */ | |
360 | void dm_table_event(struct dm_table *t); | |
361 | ||
362 | /* | |
363 | * The device must be suspended before calling this method. | |
042d2a9b | 364 | * Returns the previous table, which the caller must destroy. |
17b2f66f | 365 | */ |
042d2a9b AK |
366 | struct dm_table *dm_swap_table(struct mapped_device *md, |
367 | struct dm_table *t); | |
17b2f66f | 368 | |
54160904 MP |
369 | /* |
370 | * A wrapper around vmalloc. | |
371 | */ | |
372 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); | |
373 | ||
0da336e5 AK |
374 | /*----------------------------------------------------------------- |
375 | * Macros. | |
376 | *---------------------------------------------------------------*/ | |
377 | #define DM_NAME "device-mapper" | |
378 | ||
71a16736 NK |
379 | #ifdef CONFIG_PRINTK |
380 | extern struct ratelimit_state dm_ratelimit_state; | |
381 | ||
382 | #define dm_ratelimit() __ratelimit(&dm_ratelimit_state) | |
383 | #else | |
384 | #define dm_ratelimit() 0 | |
385 | #endif | |
386 | ||
10d3bd09 MP |
387 | #define DMCRIT(f, arg...) \ |
388 | printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
389 | ||
0da336e5 AK |
390 | #define DMERR(f, arg...) \ |
391 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
392 | #define DMERR_LIMIT(f, arg...) \ | |
393 | do { \ | |
71a16736 | 394 | if (dm_ratelimit()) \ |
0da336e5 AK |
395 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \ |
396 | f "\n", ## arg); \ | |
397 | } while (0) | |
398 | ||
399 | #define DMWARN(f, arg...) \ | |
400 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
401 | #define DMWARN_LIMIT(f, arg...) \ | |
402 | do { \ | |
71a16736 | 403 | if (dm_ratelimit()) \ |
0da336e5 AK |
404 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \ |
405 | f "\n", ## arg); \ | |
406 | } while (0) | |
407 | ||
408 | #define DMINFO(f, arg...) \ | |
409 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
410 | #define DMINFO_LIMIT(f, arg...) \ | |
411 | do { \ | |
71a16736 | 412 | if (dm_ratelimit()) \ |
0da336e5 AK |
413 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \ |
414 | "\n", ## arg); \ | |
415 | } while (0) | |
416 | ||
417 | #ifdef CONFIG_DM_DEBUG | |
418 | # define DMDEBUG(f, arg...) \ | |
419 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg) | |
420 | # define DMDEBUG_LIMIT(f, arg...) \ | |
421 | do { \ | |
71a16736 | 422 | if (dm_ratelimit()) \ |
0da336e5 AK |
423 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \ |
424 | "\n", ## arg); \ | |
425 | } while (0) | |
426 | #else | |
427 | # define DMDEBUG(f, arg...) do {} while (0) | |
428 | # define DMDEBUG_LIMIT(f, arg...) do {} while (0) | |
429 | #endif | |
430 | ||
431 | #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ | |
432 | 0 : scnprintf(result + sz, maxlen - sz, x)) | |
433 | ||
434 | #define SECTOR_SHIFT 9 | |
435 | ||
436 | /* | |
437 | * Definitions of return values from target end_io function. | |
438 | */ | |
439 | #define DM_ENDIO_INCOMPLETE 1 | |
440 | #define DM_ENDIO_REQUEUE 2 | |
441 | ||
442 | /* | |
443 | * Definitions of return values from target map function. | |
444 | */ | |
445 | #define DM_MAPIO_SUBMITTED 0 | |
446 | #define DM_MAPIO_REMAPPED 1 | |
447 | #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE | |
448 | ||
449 | /* | |
450 | * Ceiling(n / sz) | |
451 | */ | |
452 | #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz)) | |
453 | ||
454 | #define dm_sector_div_up(n, sz) ( \ | |
455 | { \ | |
456 | sector_t _r = ((n) + (sz) - 1); \ | |
457 | sector_div(_r, (sz)); \ | |
458 | _r; \ | |
459 | } \ | |
460 | ) | |
461 | ||
462 | /* | |
463 | * ceiling(n / size) * size | |
464 | */ | |
465 | #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz)) | |
466 | ||
d63a5ce3 MP |
467 | #define dm_array_too_big(fixed, obj, num) \ |
468 | ((num) > (UINT_MAX - (fixed)) / (obj)) | |
469 | ||
56a67df7 MS |
470 | /* |
471 | * Sector offset taken relative to the start of the target instead of | |
472 | * relative to the start of the device. | |
473 | */ | |
474 | #define dm_target_offset(ti, sector) ((sector) - (ti)->begin) | |
475 | ||
0da336e5 AK |
476 | static inline sector_t to_sector(unsigned long n) |
477 | { | |
478 | return (n >> SECTOR_SHIFT); | |
479 | } | |
480 | ||
481 | static inline unsigned long to_bytes(sector_t n) | |
482 | { | |
483 | return (n << SECTOR_SHIFT); | |
484 | } | |
485 | ||
cec47e3d KU |
486 | /*----------------------------------------------------------------- |
487 | * Helper for block layer and dm core operations | |
488 | *---------------------------------------------------------------*/ | |
489 | void dm_dispatch_request(struct request *rq); | |
490 | void dm_requeue_unmapped_request(struct request *rq); | |
491 | void dm_kill_unmapped_request(struct request *rq, int error); | |
492 | int dm_underlying_device_busy(struct request_queue *q); | |
493 | ||
17b2f66f | 494 | #endif /* _LINUX_DEVICE_MAPPER_H */ |