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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 LT |
68 | |
69 | typedef void (*dm_presuspend_fn) (struct dm_target *ti); | |
70 | typedef void (*dm_postsuspend_fn) (struct dm_target *ti); | |
8757b776 | 71 | typedef int (*dm_preresume_fn) (struct dm_target *ti); |
1da177e4 LT |
72 | typedef void (*dm_resume_fn) (struct dm_target *ti); |
73 | ||
74 | typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, | |
75 | char *result, unsigned int maxlen); | |
76 | ||
77 | typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); | |
78 | ||
647b3d00 | 79 | typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd, |
aa129a22 MB |
80 | unsigned long arg); |
81 | ||
f6fccb12 MB |
82 | typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm, |
83 | struct bio_vec *biovec, int max_size); | |
84 | ||
af4874e0 MS |
85 | typedef int (*iterate_devices_callout_fn) (struct dm_target *ti, |
86 | struct dm_dev *dev, | |
5dea271b | 87 | sector_t start, sector_t len, |
af4874e0 MS |
88 | void *data); |
89 | ||
90 | typedef int (*dm_iterate_devices_fn) (struct dm_target *ti, | |
91 | iterate_devices_callout_fn fn, | |
92 | void *data); | |
93 | ||
40bea431 MS |
94 | typedef void (*dm_io_hints_fn) (struct dm_target *ti, |
95 | struct queue_limits *limits); | |
96 | ||
7d76345d KU |
97 | /* |
98 | * Returns: | |
99 | * 0: The target can handle the next I/O immediately. | |
100 | * 1: The target can't handle the next I/O immediately. | |
101 | */ | |
102 | typedef int (*dm_busy_fn) (struct dm_target *ti); | |
103 | ||
1da177e4 LT |
104 | void dm_error(const char *message); |
105 | ||
3cb40214 BR |
106 | /* |
107 | * Combine device limits. | |
108 | */ | |
754c5fc7 | 109 | int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev, |
5dea271b | 110 | sector_t start, sector_t len, void *data); |
3cb40214 | 111 | |
82b1519b MP |
112 | struct dm_dev { |
113 | struct block_device *bdev; | |
aeb5d727 | 114 | fmode_t mode; |
82b1519b MP |
115 | char name[16]; |
116 | }; | |
117 | ||
1da177e4 LT |
118 | /* |
119 | * Constructors should call these functions to ensure destination devices | |
120 | * are opened/closed correctly. | |
1da177e4 | 121 | */ |
8215d6ec NK |
122 | int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, |
123 | struct dm_dev **result); | |
1da177e4 LT |
124 | void dm_put_device(struct dm_target *ti, struct dm_dev *d); |
125 | ||
126 | /* | |
127 | * Information about a target type | |
128 | */ | |
ab4c1424 | 129 | |
1da177e4 | 130 | struct target_type { |
ab4c1424 | 131 | uint64_t features; |
1da177e4 LT |
132 | const char *name; |
133 | struct module *module; | |
17b2f66f | 134 | unsigned version[3]; |
1da177e4 LT |
135 | dm_ctr_fn ctr; |
136 | dm_dtr_fn dtr; | |
137 | dm_map_fn map; | |
7d76345d | 138 | dm_map_request_fn map_rq; |
1da177e4 | 139 | dm_endio_fn end_io; |
7d76345d | 140 | dm_request_endio_fn rq_end_io; |
1da177e4 LT |
141 | dm_presuspend_fn presuspend; |
142 | dm_postsuspend_fn postsuspend; | |
8757b776 | 143 | dm_preresume_fn preresume; |
1da177e4 LT |
144 | dm_resume_fn resume; |
145 | dm_status_fn status; | |
146 | dm_message_fn message; | |
aa129a22 | 147 | dm_ioctl_fn ioctl; |
f6fccb12 | 148 | dm_merge_fn merge; |
7d76345d | 149 | dm_busy_fn busy; |
af4874e0 | 150 | dm_iterate_devices_fn iterate_devices; |
40bea431 | 151 | dm_io_hints_fn io_hints; |
45194e4f CR |
152 | |
153 | /* For internal device-mapper use. */ | |
154 | struct list_head list; | |
1da177e4 LT |
155 | }; |
156 | ||
3791e2fc AK |
157 | /* |
158 | * Target features | |
159 | */ | |
160 | ||
161 | /* | |
162 | * Any table that contains an instance of this target must have only one. | |
163 | */ | |
164 | #define DM_TARGET_SINGLETON 0x00000001 | |
165 | #define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON) | |
166 | ||
cc6cbe14 AK |
167 | /* |
168 | * Indicates that a target does not support read-only devices. | |
169 | */ | |
170 | #define DM_TARGET_ALWAYS_WRITEABLE 0x00000002 | |
171 | #define dm_target_always_writeable(type) \ | |
172 | ((type)->features & DM_TARGET_ALWAYS_WRITEABLE) | |
173 | ||
36a0456f AK |
174 | /* |
175 | * Any device that contains a table with an instance of this target may never | |
176 | * have tables containing any different target type. | |
177 | */ | |
178 | #define DM_TARGET_IMMUTABLE 0x00000004 | |
179 | #define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE) | |
180 | ||
1da177e4 LT |
181 | struct dm_target { |
182 | struct dm_table *table; | |
183 | struct target_type *type; | |
184 | ||
185 | /* target limits */ | |
186 | sector_t begin; | |
187 | sector_t len; | |
188 | ||
542f9038 MS |
189 | /* If non-zero, maximum size of I/O submitted to a target. */ |
190 | uint32_t max_io_len; | |
1da177e4 | 191 | |
f9ab94ce MP |
192 | /* |
193 | * A number of zero-length barrier requests that will be submitted | |
194 | * to the target for the purpose of flushing cache. | |
195 | * | |
57cba5d3 | 196 | * The request number will be placed in union map_info->target_request_nr. |
f9ab94ce MP |
197 | * It is a responsibility of the target driver to remap these requests |
198 | * to the real underlying devices. | |
199 | */ | |
200 | unsigned num_flush_requests; | |
201 | ||
5ae89a87 MS |
202 | /* |
203 | * The number of discard requests that will be submitted to the | |
204 | * target. map_info->request_nr is used just like num_flush_requests. | |
205 | */ | |
206 | unsigned num_discard_requests; | |
207 | ||
1da177e4 LT |
208 | /* target specific data */ |
209 | void *private; | |
210 | ||
211 | /* Used to provide an error string from the ctr */ | |
212 | char *error; | |
4c259327 MS |
213 | |
214 | /* | |
215 | * Set if this target needs to receive discards regardless of | |
216 | * whether or not its underlying devices have support. | |
217 | */ | |
218 | unsigned discards_supported:1; | |
983c7db3 MB |
219 | |
220 | /* | |
221 | * Set if this target does not return zeroes on discarded blocks. | |
222 | */ | |
223 | unsigned discard_zeroes_data_unsupported:1; | |
1da177e4 LT |
224 | }; |
225 | ||
9d357b07 N |
226 | /* Each target can link one of these into the table */ |
227 | struct dm_target_callbacks { | |
228 | struct list_head list; | |
229 | int (*congested_fn) (struct dm_target_callbacks *, int); | |
230 | }; | |
231 | ||
1da177e4 | 232 | int dm_register_target(struct target_type *t); |
10d3bd09 | 233 | void dm_unregister_target(struct target_type *t); |
17b2f66f | 234 | |
498f0103 MS |
235 | /* |
236 | * Target argument parsing. | |
237 | */ | |
238 | struct dm_arg_set { | |
239 | unsigned argc; | |
240 | char **argv; | |
241 | }; | |
242 | ||
243 | /* | |
244 | * The minimum and maximum value of a numeric argument, together with | |
245 | * the error message to use if the number is found to be outside that range. | |
246 | */ | |
247 | struct dm_arg { | |
248 | unsigned min; | |
249 | unsigned max; | |
250 | char *error; | |
251 | }; | |
252 | ||
253 | /* | |
254 | * Validate the next argument, either returning it as *value or, if invalid, | |
255 | * returning -EINVAL and setting *error. | |
256 | */ | |
257 | int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set, | |
258 | unsigned *value, char **error); | |
259 | ||
260 | /* | |
261 | * Process the next argument as the start of a group containing between | |
262 | * arg->min and arg->max further arguments. Either return the size as | |
263 | * *num_args or, if invalid, return -EINVAL and set *error. | |
264 | */ | |
265 | int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set, | |
266 | unsigned *num_args, char **error); | |
267 | ||
268 | /* | |
269 | * Return the current argument and shift to the next. | |
270 | */ | |
271 | const char *dm_shift_arg(struct dm_arg_set *as); | |
272 | ||
273 | /* | |
274 | * Move through num_args arguments. | |
275 | */ | |
276 | void dm_consume_args(struct dm_arg_set *as, unsigned num_args); | |
277 | ||
17b2f66f AK |
278 | /*----------------------------------------------------------------- |
279 | * Functions for creating and manipulating mapped devices. | |
280 | * Drop the reference with dm_put when you finish with the object. | |
281 | *---------------------------------------------------------------*/ | |
282 | ||
283 | /* | |
284 | * DM_ANY_MINOR chooses the next available minor number. | |
285 | */ | |
286 | #define DM_ANY_MINOR (-1) | |
287 | int dm_create(int minor, struct mapped_device **md); | |
288 | ||
289 | /* | |
290 | * Reference counting for md. | |
291 | */ | |
292 | struct mapped_device *dm_get_md(dev_t dev); | |
293 | void dm_get(struct mapped_device *md); | |
294 | void dm_put(struct mapped_device *md); | |
295 | ||
296 | /* | |
297 | * An arbitrary pointer may be stored alongside a mapped device. | |
298 | */ | |
299 | void dm_set_mdptr(struct mapped_device *md, void *ptr); | |
300 | void *dm_get_mdptr(struct mapped_device *md); | |
301 | ||
302 | /* | |
303 | * A device can still be used while suspended, but I/O is deferred. | |
304 | */ | |
a3d77d35 | 305 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags); |
17b2f66f AK |
306 | int dm_resume(struct mapped_device *md); |
307 | ||
308 | /* | |
309 | * Event functions. | |
310 | */ | |
311 | uint32_t dm_get_event_nr(struct mapped_device *md); | |
312 | int dm_wait_event(struct mapped_device *md, int event_nr); | |
7a8c3d3b MA |
313 | uint32_t dm_next_uevent_seq(struct mapped_device *md); |
314 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist); | |
17b2f66f AK |
315 | |
316 | /* | |
317 | * Info functions. | |
318 | */ | |
72d94861 | 319 | const char *dm_device_name(struct mapped_device *md); |
96a1f7db | 320 | int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid); |
17b2f66f | 321 | struct gendisk *dm_disk(struct mapped_device *md); |
64dbce58 | 322 | int dm_suspended(struct dm_target *ti); |
2e93ccc1 | 323 | int dm_noflush_suspending(struct dm_target *ti); |
89343da0 | 324 | union map_info *dm_get_mapinfo(struct bio *bio); |
cec47e3d | 325 | union map_info *dm_get_rq_mapinfo(struct request *rq); |
17b2f66f AK |
326 | |
327 | /* | |
328 | * Geometry functions. | |
329 | */ | |
330 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
331 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
332 | ||
333 | ||
334 | /*----------------------------------------------------------------- | |
335 | * Functions for manipulating device-mapper tables. | |
336 | *---------------------------------------------------------------*/ | |
337 | ||
338 | /* | |
339 | * First create an empty table. | |
340 | */ | |
aeb5d727 | 341 | int dm_table_create(struct dm_table **result, fmode_t mode, |
17b2f66f AK |
342 | unsigned num_targets, struct mapped_device *md); |
343 | ||
344 | /* | |
345 | * Then call this once for each target. | |
346 | */ | |
347 | int dm_table_add_target(struct dm_table *t, const char *type, | |
348 | sector_t start, sector_t len, char *params); | |
349 | ||
9d357b07 N |
350 | /* |
351 | * Target_ctr should call this if it needs to add any callbacks. | |
352 | */ | |
353 | void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb); | |
354 | ||
17b2f66f AK |
355 | /* |
356 | * Finally call this to make the table ready for use. | |
357 | */ | |
358 | int dm_table_complete(struct dm_table *t); | |
359 | ||
542f9038 MS |
360 | /* |
361 | * Target may require that it is never sent I/O larger than len. | |
362 | */ | |
363 | int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len); | |
364 | ||
17b2f66f AK |
365 | /* |
366 | * Table reference counting. | |
367 | */ | |
7c666411 | 368 | struct dm_table *dm_get_live_table(struct mapped_device *md); |
17b2f66f AK |
369 | void dm_table_get(struct dm_table *t); |
370 | void dm_table_put(struct dm_table *t); | |
371 | ||
372 | /* | |
373 | * Queries | |
374 | */ | |
375 | sector_t dm_table_get_size(struct dm_table *t); | |
376 | unsigned int dm_table_get_num_targets(struct dm_table *t); | |
aeb5d727 | 377 | fmode_t dm_table_get_mode(struct dm_table *t); |
17b2f66f AK |
378 | struct mapped_device *dm_table_get_md(struct dm_table *t); |
379 | ||
380 | /* | |
381 | * Trigger an event. | |
382 | */ | |
383 | void dm_table_event(struct dm_table *t); | |
384 | ||
385 | /* | |
386 | * The device must be suspended before calling this method. | |
042d2a9b | 387 | * Returns the previous table, which the caller must destroy. |
17b2f66f | 388 | */ |
042d2a9b AK |
389 | struct dm_table *dm_swap_table(struct mapped_device *md, |
390 | struct dm_table *t); | |
17b2f66f | 391 | |
54160904 MP |
392 | /* |
393 | * A wrapper around vmalloc. | |
394 | */ | |
395 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); | |
396 | ||
0da336e5 AK |
397 | /*----------------------------------------------------------------- |
398 | * Macros. | |
399 | *---------------------------------------------------------------*/ | |
400 | #define DM_NAME "device-mapper" | |
401 | ||
71a16736 NK |
402 | #ifdef CONFIG_PRINTK |
403 | extern struct ratelimit_state dm_ratelimit_state; | |
404 | ||
405 | #define dm_ratelimit() __ratelimit(&dm_ratelimit_state) | |
406 | #else | |
407 | #define dm_ratelimit() 0 | |
408 | #endif | |
409 | ||
10d3bd09 MP |
410 | #define DMCRIT(f, arg...) \ |
411 | printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
412 | ||
0da336e5 AK |
413 | #define DMERR(f, arg...) \ |
414 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
415 | #define DMERR_LIMIT(f, arg...) \ | |
416 | do { \ | |
71a16736 | 417 | if (dm_ratelimit()) \ |
0da336e5 AK |
418 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \ |
419 | f "\n", ## arg); \ | |
420 | } while (0) | |
421 | ||
422 | #define DMWARN(f, arg...) \ | |
423 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
424 | #define DMWARN_LIMIT(f, arg...) \ | |
425 | do { \ | |
71a16736 | 426 | if (dm_ratelimit()) \ |
0da336e5 AK |
427 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \ |
428 | f "\n", ## arg); \ | |
429 | } while (0) | |
430 | ||
431 | #define DMINFO(f, arg...) \ | |
432 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
433 | #define DMINFO_LIMIT(f, arg...) \ | |
434 | do { \ | |
71a16736 | 435 | if (dm_ratelimit()) \ |
0da336e5 AK |
436 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \ |
437 | "\n", ## arg); \ | |
438 | } while (0) | |
439 | ||
440 | #ifdef CONFIG_DM_DEBUG | |
441 | # define DMDEBUG(f, arg...) \ | |
442 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg) | |
443 | # define DMDEBUG_LIMIT(f, arg...) \ | |
444 | do { \ | |
71a16736 | 445 | if (dm_ratelimit()) \ |
0da336e5 AK |
446 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \ |
447 | "\n", ## arg); \ | |
448 | } while (0) | |
449 | #else | |
450 | # define DMDEBUG(f, arg...) do {} while (0) | |
451 | # define DMDEBUG_LIMIT(f, arg...) do {} while (0) | |
452 | #endif | |
453 | ||
454 | #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ | |
455 | 0 : scnprintf(result + sz, maxlen - sz, x)) | |
456 | ||
457 | #define SECTOR_SHIFT 9 | |
458 | ||
459 | /* | |
460 | * Definitions of return values from target end_io function. | |
461 | */ | |
462 | #define DM_ENDIO_INCOMPLETE 1 | |
463 | #define DM_ENDIO_REQUEUE 2 | |
464 | ||
465 | /* | |
466 | * Definitions of return values from target map function. | |
467 | */ | |
468 | #define DM_MAPIO_SUBMITTED 0 | |
469 | #define DM_MAPIO_REMAPPED 1 | |
470 | #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE | |
471 | ||
472 | /* | |
473 | * Ceiling(n / sz) | |
474 | */ | |
475 | #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz)) | |
476 | ||
477 | #define dm_sector_div_up(n, sz) ( \ | |
478 | { \ | |
479 | sector_t _r = ((n) + (sz) - 1); \ | |
480 | sector_div(_r, (sz)); \ | |
481 | _r; \ | |
482 | } \ | |
483 | ) | |
484 | ||
485 | /* | |
486 | * ceiling(n / size) * size | |
487 | */ | |
488 | #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz)) | |
489 | ||
d63a5ce3 MP |
490 | #define dm_array_too_big(fixed, obj, num) \ |
491 | ((num) > (UINT_MAX - (fixed)) / (obj)) | |
492 | ||
56a67df7 MS |
493 | /* |
494 | * Sector offset taken relative to the start of the target instead of | |
495 | * relative to the start of the device. | |
496 | */ | |
497 | #define dm_target_offset(ti, sector) ((sector) - (ti)->begin) | |
498 | ||
0da336e5 AK |
499 | static inline sector_t to_sector(unsigned long n) |
500 | { | |
501 | return (n >> SECTOR_SHIFT); | |
502 | } | |
503 | ||
504 | static inline unsigned long to_bytes(sector_t n) | |
505 | { | |
506 | return (n << SECTOR_SHIFT); | |
507 | } | |
508 | ||
cec47e3d KU |
509 | /*----------------------------------------------------------------- |
510 | * Helper for block layer and dm core operations | |
511 | *---------------------------------------------------------------*/ | |
512 | void dm_dispatch_request(struct request *rq); | |
513 | void dm_requeue_unmapped_request(struct request *rq); | |
514 | void dm_kill_unmapped_request(struct request *rq, int error); | |
515 | int dm_underlying_device_busy(struct request_queue *q); | |
516 | ||
17b2f66f | 517 | #endif /* _LINUX_DEVICE_MAPPER_H */ |