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8#ifndef _LINUX_DEVICE_MAPPER_H
9#define _LINUX_DEVICE_MAPPER_H
10
11#include <linux/bio.h>
12#include <linux/blkdev.h>
13#include <linux/math64.h>
14#include <linux/ratelimit.h>
15
16struct dm_dev;
17struct dm_target;
18struct dm_table;
19struct mapped_device;
20struct bio_vec;
21
22typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
23
24union map_info {
25 void *ptr;
26};
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31
32typedef int (*dm_ctr_fn) (struct dm_target *target,
33 unsigned int argc, char **argv);
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39typedef void (*dm_dtr_fn) (struct dm_target *ti);
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48typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio);
49typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone,
50 union map_info *map_context);
51typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti,
52 struct request *rq,
53 union map_info *map_context,
54 struct request **clone);
55typedef void (*dm_release_clone_request_fn) (struct request *clone);
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65typedef int (*dm_endio_fn) (struct dm_target *ti,
66 struct bio *bio, int error);
67typedef int (*dm_request_endio_fn) (struct dm_target *ti,
68 struct request *clone, int error,
69 union map_info *map_context);
70
71typedef void (*dm_presuspend_fn) (struct dm_target *ti);
72typedef void (*dm_presuspend_undo_fn) (struct dm_target *ti);
73typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
74typedef int (*dm_preresume_fn) (struct dm_target *ti);
75typedef void (*dm_resume_fn) (struct dm_target *ti);
76
77typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
78 unsigned status_flags, char *result, unsigned maxlen);
79
80typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
81
82typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti,
83 struct block_device **bdev, fmode_t *mode);
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95typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
96 struct dm_dev *dev,
97 sector_t start, sector_t len,
98 void *data);
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105typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
106 iterate_devices_callout_fn fn,
107 void *data);
108
109typedef void (*dm_io_hints_fn) (struct dm_target *ti,
110 struct queue_limits *limits);
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117typedef int (*dm_busy_fn) (struct dm_target *ti);
118
119void dm_error(const char *message);
120
121struct dm_dev {
122 struct block_device *bdev;
123 fmode_t mode;
124 char name[16];
125};
126
127dev_t dm_get_dev_t(const char *path);
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132
133int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
134 struct dm_dev **result);
135void dm_put_device(struct dm_target *ti, struct dm_dev *d);
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140
141struct target_type {
142 uint64_t features;
143 const char *name;
144 struct module *module;
145 unsigned version[3];
146 dm_ctr_fn ctr;
147 dm_dtr_fn dtr;
148 dm_map_fn map;
149 dm_map_request_fn map_rq;
150 dm_clone_and_map_request_fn clone_and_map_rq;
151 dm_release_clone_request_fn release_clone_rq;
152 dm_endio_fn end_io;
153 dm_request_endio_fn rq_end_io;
154 dm_presuspend_fn presuspend;
155 dm_presuspend_undo_fn presuspend_undo;
156 dm_postsuspend_fn postsuspend;
157 dm_preresume_fn preresume;
158 dm_resume_fn resume;
159 dm_status_fn status;
160 dm_message_fn message;
161 dm_prepare_ioctl_fn prepare_ioctl;
162 dm_busy_fn busy;
163 dm_iterate_devices_fn iterate_devices;
164 dm_io_hints_fn io_hints;
165
166
167 struct list_head list;
168};
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176
177#define DM_TARGET_SINGLETON 0x00000001
178#define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
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182
183#define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
184#define dm_target_always_writeable(type) \
185 ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
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191#define DM_TARGET_IMMUTABLE 0x00000004
192#define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
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198#define DM_TARGET_WILDCARD 0x00000008
199#define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD)
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206
207typedef unsigned (*dm_num_write_bios_fn) (struct dm_target *ti, struct bio *bio);
208
209struct dm_target {
210 struct dm_table *table;
211 struct target_type *type;
212
213
214 sector_t begin;
215 sector_t len;
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218 uint32_t max_io_len;
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228 unsigned num_flush_bios;
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234 unsigned num_discard_bios;
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240 unsigned num_write_same_bios;
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246 unsigned per_io_data_size;
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253 dm_num_write_bios_fn num_write_bios;
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256 void *private;
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259 char *error;
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265 bool flush_supported:1;
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271 bool discards_supported:1;
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277 bool split_discard_bios:1;
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282 bool discard_zeroes_data_unsupported:1;
283};
284
285
286struct dm_target_callbacks {
287 struct list_head list;
288 int (*congested_fn) (struct dm_target_callbacks *, int);
289};
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298struct dm_target_io {
299 struct dm_io *io;
300 struct dm_target *ti;
301 unsigned target_bio_nr;
302 unsigned *len_ptr;
303 struct bio clone;
304};
305
306static inline void *dm_per_bio_data(struct bio *bio, size_t data_size)
307{
308 return (char *)bio - offsetof(struct dm_target_io, clone) - data_size;
309}
310
311static inline struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
312{
313 return (struct bio *)((char *)data + data_size + offsetof(struct dm_target_io, clone));
314}
315
316static inline unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
317{
318 return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
319}
320
321int dm_register_target(struct target_type *t);
322void dm_unregister_target(struct target_type *t);
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327struct dm_arg_set {
328 unsigned argc;
329 char **argv;
330};
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336struct dm_arg {
337 unsigned min;
338 unsigned max;
339 char *error;
340};
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346int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
347 unsigned *value, char **error);
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354int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
355 unsigned *num_args, char **error);
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360const char *dm_shift_arg(struct dm_arg_set *as);
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365void dm_consume_args(struct dm_arg_set *as, unsigned num_args);
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375#define DM_ANY_MINOR (-1)
376int dm_create(int minor, struct mapped_device **md);
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381struct mapped_device *dm_get_md(dev_t dev);
382void dm_get(struct mapped_device *md);
383int dm_hold(struct mapped_device *md);
384void dm_put(struct mapped_device *md);
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389void dm_set_mdptr(struct mapped_device *md, void *ptr);
390void *dm_get_mdptr(struct mapped_device *md);
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395int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
396int dm_resume(struct mapped_device *md);
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401uint32_t dm_get_event_nr(struct mapped_device *md);
402int dm_wait_event(struct mapped_device *md, int event_nr);
403uint32_t dm_next_uevent_seq(struct mapped_device *md);
404void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
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409const char *dm_device_name(struct mapped_device *md);
410int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
411struct gendisk *dm_disk(struct mapped_device *md);
412int dm_suspended(struct dm_target *ti);
413int dm_noflush_suspending(struct dm_target *ti);
414void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors);
415union map_info *dm_get_rq_mapinfo(struct request *rq);
416
417struct queue_limits *dm_get_queue_limits(struct mapped_device *md);
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422int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
423int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
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432int dm_table_create(struct dm_table **result, fmode_t mode,
433 unsigned num_targets, struct mapped_device *md);
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438int dm_table_add_target(struct dm_table *t, const char *type,
439 sector_t start, sector_t len, char *params);
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444void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb);
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449int dm_table_complete(struct dm_table *t);
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454int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
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459struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);
460void dm_put_live_table(struct mapped_device *md, int srcu_idx);
461void dm_sync_table(struct mapped_device *md);
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466sector_t dm_table_get_size(struct dm_table *t);
467unsigned int dm_table_get_num_targets(struct dm_table *t);
468fmode_t dm_table_get_mode(struct dm_table *t);
469struct mapped_device *dm_table_get_md(struct dm_table *t);
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474void dm_table_event(struct dm_table *t);
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479void dm_table_run_md_queue_async(struct dm_table *t);
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485struct dm_table *dm_swap_table(struct mapped_device *md,
486 struct dm_table *t);
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490
491void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
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495
496#define DM_NAME "device-mapper"
497
498#ifdef CONFIG_PRINTK
499extern struct ratelimit_state dm_ratelimit_state;
500
501#define dm_ratelimit() __ratelimit(&dm_ratelimit_state)
502#else
503#define dm_ratelimit() 0
504#endif
505
506#define DMCRIT(f, arg...) \
507 printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
508
509#define DMERR(f, arg...) \
510 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
511#define DMERR_LIMIT(f, arg...) \
512 do { \
513 if (dm_ratelimit()) \
514 printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
515 f "\n", ## arg); \
516 } while (0)
517
518#define DMWARN(f, arg...) \
519 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
520#define DMWARN_LIMIT(f, arg...) \
521 do { \
522 if (dm_ratelimit()) \
523 printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
524 f "\n", ## arg); \
525 } while (0)
526
527#define DMINFO(f, arg...) \
528 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
529#define DMINFO_LIMIT(f, arg...) \
530 do { \
531 if (dm_ratelimit()) \
532 printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
533 "\n", ## arg); \
534 } while (0)
535
536#ifdef CONFIG_DM_DEBUG
537# define DMDEBUG(f, arg...) \
538 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
539# define DMDEBUG_LIMIT(f, arg...) \
540 do { \
541 if (dm_ratelimit()) \
542 printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
543 "\n", ## arg); \
544 } while (0)
545#else
546# define DMDEBUG(f, arg...) do {} while (0)
547# define DMDEBUG_LIMIT(f, arg...) do {} while (0)
548#endif
549
550#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
551 0 : scnprintf(result + sz, maxlen - sz, x))
552
553#define SECTOR_SHIFT 9
554
555
556
557
558#define DM_ENDIO_INCOMPLETE 1
559#define DM_ENDIO_REQUEUE 2
560
561
562
563
564#define DM_MAPIO_SUBMITTED 0
565#define DM_MAPIO_REMAPPED 1
566#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
567
568#define dm_sector_div64(x, y)( \
569{ \
570 u64 _res; \
571 (x) = div64_u64_rem(x, y, &_res); \
572 _res; \
573} \
574)
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576
577
578
579#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
580
581#define dm_sector_div_up(n, sz) ( \
582{ \
583 sector_t _r = ((n) + (sz) - 1); \
584 sector_div(_r, (sz)); \
585 _r; \
586} \
587)
588
589
590
591
592#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
593
594#define dm_array_too_big(fixed, obj, num) \
595 ((num) > (UINT_MAX - (fixed)) / (obj))
596
597
598
599
600
601#define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
602
603static inline sector_t to_sector(unsigned long n)
604{
605 return (n >> SECTOR_SHIFT);
606}
607
608static inline unsigned long to_bytes(sector_t n)
609{
610 return (n << SECTOR_SHIFT);
611}
612
613#endif
614