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> |
416cd17b | 13 | |
af4874e0 | 14 | struct dm_dev; |
1da177e4 LT |
15 | struct dm_target; |
16 | struct dm_table; | |
17b2f66f | 17 | struct mapped_device; |
f6fccb12 | 18 | struct bio_vec; |
1da177e4 LT |
19 | |
20 | typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; | |
21 | ||
22 | union map_info { | |
23 | void *ptr; | |
24 | unsigned long long ll; | |
f9ab94ce | 25 | unsigned flush_request; |
1da177e4 LT |
26 | }; |
27 | ||
28 | /* | |
29 | * In the constructor the target parameter will already have the | |
30 | * table, type, begin and len fields filled in. | |
31 | */ | |
32 | typedef int (*dm_ctr_fn) (struct dm_target *target, | |
33 | unsigned int argc, char **argv); | |
34 | ||
35 | /* | |
36 | * The destructor doesn't need to free the dm_target, just | |
37 | * anything hidden ti->private. | |
38 | */ | |
39 | typedef void (*dm_dtr_fn) (struct dm_target *ti); | |
40 | ||
41 | /* | |
42 | * The map function must return: | |
43 | * < 0: error | |
44 | * = 0: The target will handle the io by resubmitting it later | |
45cbcd79 | 45 | * = 1: simple remap complete |
2e93ccc1 | 46 | * = 2: The target wants to push back the io |
1da177e4 LT |
47 | */ |
48 | typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, | |
49 | union map_info *map_context); | |
7d76345d KU |
50 | typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, |
51 | union map_info *map_context); | |
1da177e4 LT |
52 | |
53 | /* | |
54 | * Returns: | |
55 | * < 0 : error (currently ignored) | |
56 | * 0 : ended successfully | |
57 | * 1 : for some reason the io has still not completed (eg, | |
58 | * multipath target might want to requeue a failed io). | |
2e93ccc1 | 59 | * 2 : The target wants to push back the io |
1da177e4 LT |
60 | */ |
61 | typedef int (*dm_endio_fn) (struct dm_target *ti, | |
62 | struct bio *bio, int error, | |
63 | union map_info *map_context); | |
7d76345d KU |
64 | typedef int (*dm_request_endio_fn) (struct dm_target *ti, |
65 | struct request *clone, int error, | |
66 | union map_info *map_context); | |
1da177e4 | 67 | |
999d8168 | 68 | typedef void (*dm_flush_fn) (struct dm_target *ti); |
1da177e4 LT |
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. | |
121 | * FIXME: too many arguments. | |
122 | */ | |
123 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, | |
aeb5d727 | 124 | sector_t len, fmode_t mode, 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 | * | |
178 | * The request number will be placed in union map_info->flush_request. | |
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 | ||
1da177e4 LT |
184 | /* target specific data */ |
185 | void *private; | |
186 | ||
187 | /* Used to provide an error string from the ctr */ | |
188 | char *error; | |
189 | }; | |
190 | ||
191 | int dm_register_target(struct target_type *t); | |
10d3bd09 | 192 | void dm_unregister_target(struct target_type *t); |
17b2f66f AK |
193 | |
194 | /*----------------------------------------------------------------- | |
195 | * Functions for creating and manipulating mapped devices. | |
196 | * Drop the reference with dm_put when you finish with the object. | |
197 | *---------------------------------------------------------------*/ | |
198 | ||
199 | /* | |
200 | * DM_ANY_MINOR chooses the next available minor number. | |
201 | */ | |
202 | #define DM_ANY_MINOR (-1) | |
203 | int dm_create(int minor, struct mapped_device **md); | |
204 | ||
205 | /* | |
206 | * Reference counting for md. | |
207 | */ | |
208 | struct mapped_device *dm_get_md(dev_t dev); | |
209 | void dm_get(struct mapped_device *md); | |
210 | void dm_put(struct mapped_device *md); | |
211 | ||
212 | /* | |
213 | * An arbitrary pointer may be stored alongside a mapped device. | |
214 | */ | |
215 | void dm_set_mdptr(struct mapped_device *md, void *ptr); | |
216 | void *dm_get_mdptr(struct mapped_device *md); | |
217 | ||
218 | /* | |
219 | * A device can still be used while suspended, but I/O is deferred. | |
220 | */ | |
a3d77d35 | 221 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags); |
17b2f66f AK |
222 | int dm_resume(struct mapped_device *md); |
223 | ||
224 | /* | |
225 | * Event functions. | |
226 | */ | |
227 | uint32_t dm_get_event_nr(struct mapped_device *md); | |
228 | int dm_wait_event(struct mapped_device *md, int event_nr); | |
7a8c3d3b MA |
229 | uint32_t dm_next_uevent_seq(struct mapped_device *md); |
230 | void dm_uevent_add(struct mapped_device *md, struct list_head *elist); | |
17b2f66f AK |
231 | |
232 | /* | |
233 | * Info functions. | |
234 | */ | |
72d94861 | 235 | const char *dm_device_name(struct mapped_device *md); |
96a1f7db | 236 | int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid); |
17b2f66f AK |
237 | struct gendisk *dm_disk(struct mapped_device *md); |
238 | int dm_suspended(struct mapped_device *md); | |
2e93ccc1 | 239 | int dm_noflush_suspending(struct dm_target *ti); |
89343da0 | 240 | union map_info *dm_get_mapinfo(struct bio *bio); |
cec47e3d | 241 | union map_info *dm_get_rq_mapinfo(struct request *rq); |
17b2f66f AK |
242 | |
243 | /* | |
244 | * Geometry functions. | |
245 | */ | |
246 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
247 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
248 | ||
249 | ||
250 | /*----------------------------------------------------------------- | |
251 | * Functions for manipulating device-mapper tables. | |
252 | *---------------------------------------------------------------*/ | |
253 | ||
254 | /* | |
255 | * First create an empty table. | |
256 | */ | |
aeb5d727 | 257 | int dm_table_create(struct dm_table **result, fmode_t mode, |
17b2f66f AK |
258 | unsigned num_targets, struct mapped_device *md); |
259 | ||
260 | /* | |
261 | * Then call this once for each target. | |
262 | */ | |
263 | int dm_table_add_target(struct dm_table *t, const char *type, | |
264 | sector_t start, sector_t len, char *params); | |
265 | ||
266 | /* | |
267 | * Finally call this to make the table ready for use. | |
268 | */ | |
269 | int dm_table_complete(struct dm_table *t); | |
270 | ||
ea0ec640 MP |
271 | /* |
272 | * Unplug all devices in a table. | |
273 | */ | |
274 | void dm_table_unplug_all(struct dm_table *t); | |
275 | ||
17b2f66f AK |
276 | /* |
277 | * Table reference counting. | |
278 | */ | |
279 | struct dm_table *dm_get_table(struct mapped_device *md); | |
280 | void dm_table_get(struct dm_table *t); | |
281 | void dm_table_put(struct dm_table *t); | |
282 | ||
283 | /* | |
284 | * Queries | |
285 | */ | |
286 | sector_t dm_table_get_size(struct dm_table *t); | |
287 | unsigned int dm_table_get_num_targets(struct dm_table *t); | |
aeb5d727 | 288 | fmode_t dm_table_get_mode(struct dm_table *t); |
17b2f66f AK |
289 | struct mapped_device *dm_table_get_md(struct dm_table *t); |
290 | ||
291 | /* | |
292 | * Trigger an event. | |
293 | */ | |
294 | void dm_table_event(struct dm_table *t); | |
295 | ||
296 | /* | |
297 | * The device must be suspended before calling this method. | |
298 | */ | |
299 | int dm_swap_table(struct mapped_device *md, struct dm_table *t); | |
300 | ||
54160904 MP |
301 | /* |
302 | * A wrapper around vmalloc. | |
303 | */ | |
304 | void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); | |
305 | ||
0da336e5 AK |
306 | /*----------------------------------------------------------------- |
307 | * Macros. | |
308 | *---------------------------------------------------------------*/ | |
309 | #define DM_NAME "device-mapper" | |
310 | ||
10d3bd09 MP |
311 | #define DMCRIT(f, arg...) \ |
312 | printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
313 | ||
0da336e5 AK |
314 | #define DMERR(f, arg...) \ |
315 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
316 | #define DMERR_LIMIT(f, arg...) \ | |
317 | do { \ | |
318 | if (printk_ratelimit()) \ | |
319 | printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \ | |
320 | f "\n", ## arg); \ | |
321 | } while (0) | |
322 | ||
323 | #define DMWARN(f, arg...) \ | |
324 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
325 | #define DMWARN_LIMIT(f, arg...) \ | |
326 | do { \ | |
327 | if (printk_ratelimit()) \ | |
328 | printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \ | |
329 | f "\n", ## arg); \ | |
330 | } while (0) | |
331 | ||
332 | #define DMINFO(f, arg...) \ | |
333 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg) | |
334 | #define DMINFO_LIMIT(f, arg...) \ | |
335 | do { \ | |
336 | if (printk_ratelimit()) \ | |
337 | printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \ | |
338 | "\n", ## arg); \ | |
339 | } while (0) | |
340 | ||
341 | #ifdef CONFIG_DM_DEBUG | |
342 | # define DMDEBUG(f, arg...) \ | |
343 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg) | |
344 | # define DMDEBUG_LIMIT(f, arg...) \ | |
345 | do { \ | |
346 | if (printk_ratelimit()) \ | |
347 | printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \ | |
348 | "\n", ## arg); \ | |
349 | } while (0) | |
350 | #else | |
351 | # define DMDEBUG(f, arg...) do {} while (0) | |
352 | # define DMDEBUG_LIMIT(f, arg...) do {} while (0) | |
353 | #endif | |
354 | ||
355 | #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ | |
356 | 0 : scnprintf(result + sz, maxlen - sz, x)) | |
357 | ||
358 | #define SECTOR_SHIFT 9 | |
359 | ||
360 | /* | |
361 | * Definitions of return values from target end_io function. | |
362 | */ | |
363 | #define DM_ENDIO_INCOMPLETE 1 | |
364 | #define DM_ENDIO_REQUEUE 2 | |
365 | ||
366 | /* | |
367 | * Definitions of return values from target map function. | |
368 | */ | |
369 | #define DM_MAPIO_SUBMITTED 0 | |
370 | #define DM_MAPIO_REMAPPED 1 | |
371 | #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE | |
372 | ||
373 | /* | |
374 | * Ceiling(n / sz) | |
375 | */ | |
376 | #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz)) | |
377 | ||
378 | #define dm_sector_div_up(n, sz) ( \ | |
379 | { \ | |
380 | sector_t _r = ((n) + (sz) - 1); \ | |
381 | sector_div(_r, (sz)); \ | |
382 | _r; \ | |
383 | } \ | |
384 | ) | |
385 | ||
386 | /* | |
387 | * ceiling(n / size) * size | |
388 | */ | |
389 | #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz)) | |
390 | ||
d63a5ce3 MP |
391 | #define dm_array_too_big(fixed, obj, num) \ |
392 | ((num) > (UINT_MAX - (fixed)) / (obj)) | |
393 | ||
0da336e5 AK |
394 | static inline sector_t to_sector(unsigned long n) |
395 | { | |
396 | return (n >> SECTOR_SHIFT); | |
397 | } | |
398 | ||
399 | static inline unsigned long to_bytes(sector_t n) | |
400 | { | |
401 | return (n << SECTOR_SHIFT); | |
402 | } | |
403 | ||
cec47e3d KU |
404 | /*----------------------------------------------------------------- |
405 | * Helper for block layer and dm core operations | |
406 | *---------------------------------------------------------------*/ | |
407 | void dm_dispatch_request(struct request *rq); | |
408 | void dm_requeue_unmapped_request(struct request *rq); | |
409 | void dm_kill_unmapped_request(struct request *rq, int error); | |
410 | int dm_underlying_device_busy(struct request_queue *q); | |
411 | ||
17b2f66f | 412 | #endif /* _LINUX_DEVICE_MAPPER_H */ |