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dm: rename dm_suspended to dm_suspended_md
[net-next-2.6.git] / include / linux / device-mapper.h
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1da177e4
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1/*
2 * Copyright (C) 2001 Sistina Software (UK) Limited.
0da336e5 3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
1da177e4
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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 14struct dm_dev;
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15struct dm_target;
16struct dm_table;
17b2f66f 17struct mapped_device;
f6fccb12 18struct bio_vec;
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19
20typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
21
22union map_info {
23 void *ptr;
24 unsigned long long ll;
f9ab94ce 25 unsigned flush_request;
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26};
27
28/*
29 * In the constructor the target parameter will already have the
30 * table, type, begin and len fields filled in.
31 */
32typedef 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 */
39typedef 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
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47 */
48typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
49 union map_info *map_context);
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50typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone,
51 union map_info *map_context);
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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
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60 */
61typedef int (*dm_endio_fn) (struct dm_target *ti,
62 struct bio *bio, int error,
63 union map_info *map_context);
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64typedef int (*dm_request_endio_fn) (struct dm_target *ti,
65 struct request *clone, int error,
66 union map_info *map_context);
1da177e4 67
999d8168 68typedef void (*dm_flush_fn) (struct dm_target *ti);
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69typedef void (*dm_presuspend_fn) (struct dm_target *ti);
70typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
8757b776 71typedef int (*dm_preresume_fn) (struct dm_target *ti);
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72typedef void (*dm_resume_fn) (struct dm_target *ti);
73
74typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
75 char *result, unsigned int maxlen);
76
77typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
78
647b3d00 79typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd,
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80 unsigned long arg);
81
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82typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
83 struct bio_vec *biovec, int max_size);
84
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85typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
86 struct dm_dev *dev,
5dea271b 87 sector_t start, sector_t len,
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88 void *data);
89
90typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
91 iterate_devices_callout_fn fn,
92 void *data);
93
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94typedef void (*dm_io_hints_fn) (struct dm_target *ti,
95 struct queue_limits *limits);
96
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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 */
102typedef int (*dm_busy_fn) (struct dm_target *ti);
103
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104void dm_error(const char *message);
105
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106/*
107 * Combine device limits.
108 */
754c5fc7 109int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
5dea271b 110 sector_t start, sector_t len, void *data);
3cb40214 111
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112struct dm_dev {
113 struct block_device *bdev;
aeb5d727 114 fmode_t mode;
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115 char name[16];
116};
117
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118/*
119 * Constructors should call these functions to ensure destination devices
120 * are opened/closed correctly.
121 * FIXME: too many arguments.
122 */
123int 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);
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125void dm_put_device(struct dm_target *ti, struct dm_dev *d);
126
127/*
128 * Information about a target type
129 */
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130
131/*
132 * Target features
133 */
ab4c1424 134
1da177e4 135struct target_type {
ab4c1424 136 uint64_t features;
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137 const char *name;
138 struct module *module;
17b2f66f 139 unsigned version[3];
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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;
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147 dm_presuspend_fn presuspend;
148 dm_postsuspend_fn postsuspend;
8757b776 149 dm_preresume_fn preresume;
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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;
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158
159 /* For internal device-mapper use. */
160 struct list_head list;
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161};
162
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163struct 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
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171 /* Always a power of 2 */
172 sector_t split_io;
173
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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
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184 /* target specific data */
185 void *private;
186
187 /* Used to provide an error string from the ctr */
188 char *error;
189};
190
191int dm_register_target(struct target_type *t);
10d3bd09 192void dm_unregister_target(struct target_type *t);
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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)
203int dm_create(int minor, struct mapped_device **md);
204
205/*
206 * Reference counting for md.
207 */
208struct mapped_device *dm_get_md(dev_t dev);
209void dm_get(struct mapped_device *md);
210void dm_put(struct mapped_device *md);
211
212/*
213 * An arbitrary pointer may be stored alongside a mapped device.
214 */
215void dm_set_mdptr(struct mapped_device *md, void *ptr);
216void *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 221int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
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222int dm_resume(struct mapped_device *md);
223
224/*
225 * Event functions.
226 */
227uint32_t dm_get_event_nr(struct mapped_device *md);
228int dm_wait_event(struct mapped_device *md, int event_nr);
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229uint32_t dm_next_uevent_seq(struct mapped_device *md);
230void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
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231
232/*
233 * Info functions.
234 */
72d94861 235const char *dm_device_name(struct mapped_device *md);
96a1f7db 236int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
17b2f66f 237struct gendisk *dm_disk(struct mapped_device *md);
2e93ccc1 238int dm_noflush_suspending(struct dm_target *ti);
89343da0 239union map_info *dm_get_mapinfo(struct bio *bio);
cec47e3d 240union map_info *dm_get_rq_mapinfo(struct request *rq);
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241
242/*
243 * Geometry functions.
244 */
245int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
246int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
247
248
249/*-----------------------------------------------------------------
250 * Functions for manipulating device-mapper tables.
251 *---------------------------------------------------------------*/
252
253/*
254 * First create an empty table.
255 */
aeb5d727 256int dm_table_create(struct dm_table **result, fmode_t mode,
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257 unsigned num_targets, struct mapped_device *md);
258
259/*
260 * Then call this once for each target.
261 */
262int dm_table_add_target(struct dm_table *t, const char *type,
263 sector_t start, sector_t len, char *params);
264
265/*
266 * Finally call this to make the table ready for use.
267 */
268int dm_table_complete(struct dm_table *t);
269
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270/*
271 * Unplug all devices in a table.
272 */
273void dm_table_unplug_all(struct dm_table *t);
274
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275/*
276 * Table reference counting.
277 */
7c666411 278struct dm_table *dm_get_live_table(struct mapped_device *md);
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279void dm_table_get(struct dm_table *t);
280void dm_table_put(struct dm_table *t);
281
282/*
283 * Queries
284 */
285sector_t dm_table_get_size(struct dm_table *t);
286unsigned int dm_table_get_num_targets(struct dm_table *t);
aeb5d727 287fmode_t dm_table_get_mode(struct dm_table *t);
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288struct mapped_device *dm_table_get_md(struct dm_table *t);
289
290/*
291 * Trigger an event.
292 */
293void dm_table_event(struct dm_table *t);
294
295/*
296 * The device must be suspended before calling this method.
042d2a9b 297 * Returns the previous table, which the caller must destroy.
17b2f66f 298 */
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299struct dm_table *dm_swap_table(struct mapped_device *md,
300 struct dm_table *t);
17b2f66f 301
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302/*
303 * A wrapper around vmalloc.
304 */
305void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
306
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307/*-----------------------------------------------------------------
308 * Macros.
309 *---------------------------------------------------------------*/
310#define DM_NAME "device-mapper"
311
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312#define DMCRIT(f, arg...) \
313 printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
314
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315#define DMERR(f, arg...) \
316 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
317#define DMERR_LIMIT(f, arg...) \
318 do { \
319 if (printk_ratelimit()) \
320 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
321 f "\n", ## arg); \
322 } while (0)
323
324#define DMWARN(f, arg...) \
325 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
326#define DMWARN_LIMIT(f, arg...) \
327 do { \
328 if (printk_ratelimit()) \
329 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
330 f "\n", ## arg); \
331 } while (0)
332
333#define DMINFO(f, arg...) \
334 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
335#define DMINFO_LIMIT(f, arg...) \
336 do { \
337 if (printk_ratelimit()) \
338 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
339 "\n", ## arg); \
340 } while (0)
341
342#ifdef CONFIG_DM_DEBUG
343# define DMDEBUG(f, arg...) \
344 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
345# define DMDEBUG_LIMIT(f, arg...) \
346 do { \
347 if (printk_ratelimit()) \
348 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
349 "\n", ## arg); \
350 } while (0)
351#else
352# define DMDEBUG(f, arg...) do {} while (0)
353# define DMDEBUG_LIMIT(f, arg...) do {} while (0)
354#endif
355
356#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
357 0 : scnprintf(result + sz, maxlen - sz, x))
358
359#define SECTOR_SHIFT 9
360
361/*
362 * Definitions of return values from target end_io function.
363 */
364#define DM_ENDIO_INCOMPLETE 1
365#define DM_ENDIO_REQUEUE 2
366
367/*
368 * Definitions of return values from target map function.
369 */
370#define DM_MAPIO_SUBMITTED 0
371#define DM_MAPIO_REMAPPED 1
372#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
373
374/*
375 * Ceiling(n / sz)
376 */
377#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
378
379#define dm_sector_div_up(n, sz) ( \
380{ \
381 sector_t _r = ((n) + (sz) - 1); \
382 sector_div(_r, (sz)); \
383 _r; \
384} \
385)
386
387/*
388 * ceiling(n / size) * size
389 */
390#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
391
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392#define dm_array_too_big(fixed, obj, num) \
393 ((num) > (UINT_MAX - (fixed)) / (obj))
394
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395static inline sector_t to_sector(unsigned long n)
396{
397 return (n >> SECTOR_SHIFT);
398}
399
400static inline unsigned long to_bytes(sector_t n)
401{
402 return (n << SECTOR_SHIFT);
403}
404
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405/*-----------------------------------------------------------------
406 * Helper for block layer and dm core operations
407 *---------------------------------------------------------------*/
408void dm_dispatch_request(struct request *rq);
409void dm_requeue_unmapped_request(struct request *rq);
410void dm_kill_unmapped_request(struct request *rq, int error);
411int dm_underlying_device_busy(struct request_queue *q);
412
17b2f66f 413#endif /* _LINUX_DEVICE_MAPPER_H */