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dm log: fix create_log_context to use logical_block_size of log device
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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,
87 sector_t physical_start,
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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94/*
95 * Returns:
96 * 0: The target can handle the next I/O immediately.
97 * 1: The target can't handle the next I/O immediately.
98 */
99typedef int (*dm_busy_fn) (struct dm_target *ti);
100
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101void dm_error(const char *message);
102
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103/*
104 * Combine device limits.
105 */
106void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev);
107
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108struct dm_dev {
109 struct block_device *bdev;
aeb5d727 110 fmode_t mode;
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111 char name[16];
112};
113
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114/*
115 * Constructors should call these functions to ensure destination devices
116 * are opened/closed correctly.
117 * FIXME: too many arguments.
118 */
119int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
aeb5d727 120 sector_t len, fmode_t mode, struct dm_dev **result);
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121void dm_put_device(struct dm_target *ti, struct dm_dev *d);
122
123/*
124 * Information about a target type
125 */
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126
127/*
128 * Target features
129 */
ab4c1424 130
1da177e4 131struct target_type {
ab4c1424 132 uint64_t features;
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133 const char *name;
134 struct module *module;
17b2f66f 135 unsigned version[3];
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136 dm_ctr_fn ctr;
137 dm_dtr_fn dtr;
138 dm_map_fn map;
7d76345d 139 dm_map_request_fn map_rq;
1da177e4 140 dm_endio_fn end_io;
7d76345d 141 dm_request_endio_fn rq_end_io;
999d8168 142 dm_flush_fn flush;
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143 dm_presuspend_fn presuspend;
144 dm_postsuspend_fn postsuspend;
8757b776 145 dm_preresume_fn preresume;
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146 dm_resume_fn resume;
147 dm_status_fn status;
148 dm_message_fn message;
aa129a22 149 dm_ioctl_fn ioctl;
f6fccb12 150 dm_merge_fn merge;
7d76345d 151 dm_busy_fn busy;
af4874e0 152 dm_iterate_devices_fn iterate_devices;
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153
154 /* For internal device-mapper use. */
155 struct list_head list;
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156};
157
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158struct dm_target {
159 struct dm_table *table;
160 struct target_type *type;
161
162 /* target limits */
163 sector_t begin;
164 sector_t len;
165
5ab97588 166 /* FIXME: turn this into a mask, and merge with queue_limits */
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167 /* Always a power of 2 */
168 sector_t split_io;
169
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MP
170 /*
171 * A number of zero-length barrier requests that will be submitted
172 * to the target for the purpose of flushing cache.
173 *
174 * The request number will be placed in union map_info->flush_request.
175 * It is a responsibility of the target driver to remap these requests
176 * to the real underlying devices.
177 */
178 unsigned num_flush_requests;
179
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180 /*
181 * These are automatically filled in by
182 * dm_table_get_device.
183 */
5ab97588 184 struct queue_limits limits;
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185
186 /* target specific data */
187 void *private;
188
189 /* Used to provide an error string from the ctr */
190 char *error;
191};
192
193int dm_register_target(struct target_type *t);
10d3bd09 194void dm_unregister_target(struct target_type *t);
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195
196/*-----------------------------------------------------------------
197 * Functions for creating and manipulating mapped devices.
198 * Drop the reference with dm_put when you finish with the object.
199 *---------------------------------------------------------------*/
200
201/*
202 * DM_ANY_MINOR chooses the next available minor number.
203 */
204#define DM_ANY_MINOR (-1)
205int dm_create(int minor, struct mapped_device **md);
206
207/*
208 * Reference counting for md.
209 */
210struct mapped_device *dm_get_md(dev_t dev);
211void dm_get(struct mapped_device *md);
212void dm_put(struct mapped_device *md);
213
214/*
215 * An arbitrary pointer may be stored alongside a mapped device.
216 */
217void dm_set_mdptr(struct mapped_device *md, void *ptr);
218void *dm_get_mdptr(struct mapped_device *md);
219
220/*
221 * A device can still be used while suspended, but I/O is deferred.
222 */
a3d77d35 223int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
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224int dm_resume(struct mapped_device *md);
225
226/*
227 * Event functions.
228 */
229uint32_t dm_get_event_nr(struct mapped_device *md);
230int dm_wait_event(struct mapped_device *md, int event_nr);
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231uint32_t dm_next_uevent_seq(struct mapped_device *md);
232void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
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233
234/*
235 * Info functions.
236 */
72d94861 237const char *dm_device_name(struct mapped_device *md);
96a1f7db 238int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
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239struct gendisk *dm_disk(struct mapped_device *md);
240int dm_suspended(struct mapped_device *md);
2e93ccc1 241int dm_noflush_suspending(struct dm_target *ti);
89343da0 242union map_info *dm_get_mapinfo(struct bio *bio);
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243
244/*
245 * Geometry functions.
246 */
247int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
248int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
249
250
251/*-----------------------------------------------------------------
252 * Functions for manipulating device-mapper tables.
253 *---------------------------------------------------------------*/
254
255/*
256 * First create an empty table.
257 */
aeb5d727 258int dm_table_create(struct dm_table **result, fmode_t mode,
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259 unsigned num_targets, struct mapped_device *md);
260
261/*
262 * Then call this once for each target.
263 */
264int dm_table_add_target(struct dm_table *t, const char *type,
265 sector_t start, sector_t len, char *params);
266
267/*
268 * Finally call this to make the table ready for use.
269 */
270int dm_table_complete(struct dm_table *t);
271
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272/*
273 * Unplug all devices in a table.
274 */
275void dm_table_unplug_all(struct dm_table *t);
276
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277/*
278 * Table reference counting.
279 */
280struct dm_table *dm_get_table(struct mapped_device *md);
281void dm_table_get(struct dm_table *t);
282void dm_table_put(struct dm_table *t);
283
284/*
285 * Queries
286 */
287sector_t dm_table_get_size(struct dm_table *t);
288unsigned int dm_table_get_num_targets(struct dm_table *t);
aeb5d727 289fmode_t dm_table_get_mode(struct dm_table *t);
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290struct mapped_device *dm_table_get_md(struct dm_table *t);
291
292/*
293 * Trigger an event.
294 */
295void dm_table_event(struct dm_table *t);
296
297/*
298 * The device must be suspended before calling this method.
299 */
300int dm_swap_table(struct mapped_device *md, struct dm_table *t);
301
54160904
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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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MP
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
17b2f66f 405#endif /* _LINUX_DEVICE_MAPPER_H */