1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2001 Sistina Software (UK) Limited.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the LGPL.
7 */
8
9 #ifndef _LINUX_DEVICE_MAPPER_H
10 #define _LINUX_DEVICE_MAPPER_H
11
12 #include <linux/bio.h>
13 #include <linux/blkdev.h>
14 #include <linux/dm-ioctl.h>
15 #include <linux/math64.h>
16 #include <linux/ratelimit.h>
17
18 struct dm_dev;
19 struct dm_target;
20 struct dm_table;
21 struct dm_report_zones_args;
22 struct mapped_device;
23 struct bio_vec;
24 enum dax_access_mode;
25
26 /*
27 * Type of table, mapped_device's mempool and request_queue
28 */
29 enum dm_queue_mode {
30 DM_TYPE_NONE = 0,
31 DM_TYPE_BIO_BASED = 1,
32 DM_TYPE_REQUEST_BASED = 2,
33 DM_TYPE_DAX_BIO_BASED = 3,
34 };
35
36 typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE, STATUSTYPE_IMA } status_type_t;
37
38 union map_info {
39 void *ptr;
40 };
41
42 /*
43 * In the constructor the target parameter will already have the
44 * table, type, begin and len fields filled in.
45 */
46 typedef int (*dm_ctr_fn) (struct dm_target *target,
47 unsigned int argc, char **argv);
48
49 /*
50 * The destructor doesn't need to free the dm_target, just
51 * anything hidden ti->private.
52 */
53 typedef void (*dm_dtr_fn) (struct dm_target *ti);
54
55 /*
56 * The map function must return:
57 * < 0: error
58 * = 0: The target will handle the io by resubmitting it later
59 * = 1: simple remap complete
60 * = 2: The target wants to push back the io
61 */
62 typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio);
63 typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti,
64 struct request *rq,
65 union map_info *map_context,
66 struct request **clone);
67 typedef void (*dm_release_clone_request_fn) (struct request *clone,
68 union map_info *map_context);
69
70 /*
71 * Returns:
72 * < 0 : error (currently ignored)
73 * 0 : ended successfully
74 * 1 : for some reason the io has still not completed (eg,
75 * multipath target might want to requeue a failed io).
76 * 2 : The target wants to push back the io
77 */
78 typedef int (*dm_endio_fn) (struct dm_target *ti,
79 struct bio *bio, blk_status_t *error);
80 typedef int (*dm_request_endio_fn) (struct dm_target *ti,
81 struct request *clone, blk_status_t error,
82 union map_info *map_context);
83
84 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
85 typedef void (*dm_presuspend_undo_fn) (struct dm_target *ti);
86 typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
87 typedef int (*dm_preresume_fn) (struct dm_target *ti);
88 typedef void (*dm_resume_fn) (struct dm_target *ti);
89
90 typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
91 unsigned int status_flags, char *result, unsigned int maxlen);
92
93 typedef int (*dm_message_fn) (struct dm_target *ti, unsigned int argc, char **argv,
94 char *result, unsigned int maxlen);
95
96 typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti, struct block_device **bdev);
97
98 #ifdef CONFIG_BLK_DEV_ZONED
99 typedef int (*dm_report_zones_fn) (struct dm_target *ti,
100 struct dm_report_zones_args *args,
101 unsigned int nr_zones);
102 #else
103 /*
104 * Define dm_report_zones_fn so that targets can assign to NULL if
105 * CONFIG_BLK_DEV_ZONED disabled. Otherwise each target needs to do
106 * awkward #ifdefs in their target_type, etc.
107 */
108 typedef int (*dm_report_zones_fn) (struct dm_target *dummy);
109 #endif
110
111 /*
112 * These iteration functions are typically used to check (and combine)
113 * properties of underlying devices.
114 * E.g. Does at least one underlying device support flush?
115 * Does any underlying device not support WRITE_SAME?
116 *
117 * The callout function is called once for each contiguous section of
118 * an underlying device. State can be maintained in *data.
119 * Return non-zero to stop iterating through any further devices.
120 */
121 typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
122 struct dm_dev *dev,
123 sector_t start, sector_t len,
124 void *data);
125
126 /*
127 * This function must iterate through each section of device used by the
128 * target until it encounters a non-zero return code, which it then returns.
129 * Returns zero if no callout returned non-zero.
130 */
131 typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
132 iterate_devices_callout_fn fn,
133 void *data);
134
135 typedef void (*dm_io_hints_fn) (struct dm_target *ti,
136 struct queue_limits *limits);
137
138 /*
139 * Returns:
140 * 0: The target can handle the next I/O immediately.
141 * 1: The target can't handle the next I/O immediately.
142 */
143 typedef int (*dm_busy_fn) (struct dm_target *ti);
144
145 /*
146 * Returns:
147 * < 0 : error
148 * >= 0 : the number of bytes accessible at the address
149 */
150 typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff,
151 long nr_pages, enum dax_access_mode node, void **kaddr,
152 pfn_t *pfn);
153 typedef int (*dm_dax_zero_page_range_fn)(struct dm_target *ti, pgoff_t pgoff,
154 size_t nr_pages);
155
156 /*
157 * Returns:
158 * != 0 : number of bytes transferred
159 * 0 : recovery write failed
160 */
161 typedef size_t (*dm_dax_recovery_write_fn)(struct dm_target *ti, pgoff_t pgoff,
162 void *addr, size_t bytes, struct iov_iter *i);
163
164 void dm_error(const char *message);
165
166 struct dm_dev {
167 struct block_device *bdev;
168 struct dax_device *dax_dev;
169 blk_mode_t mode;
170 char name[16];
171 };
172
173 /*
174 * Constructors should call these functions to ensure destination devices
175 * are opened/closed correctly.
176 */
177 int dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode,
178 struct dm_dev **result);
179 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
180
181 /*
182 * Information about a target type
183 */
184
185 struct target_type {
186 uint64_t features;
187 const char *name;
188 struct module *module;
189 unsigned int version[3];
190 dm_ctr_fn ctr;
191 dm_dtr_fn dtr;
192 dm_map_fn map;
193 dm_clone_and_map_request_fn clone_and_map_rq;
194 dm_release_clone_request_fn release_clone_rq;
195 dm_endio_fn end_io;
196 dm_request_endio_fn rq_end_io;
197 dm_presuspend_fn presuspend;
198 dm_presuspend_undo_fn presuspend_undo;
199 dm_postsuspend_fn postsuspend;
200 dm_preresume_fn preresume;
201 dm_resume_fn resume;
202 dm_status_fn status;
203 dm_message_fn message;
204 dm_prepare_ioctl_fn prepare_ioctl;
205 dm_report_zones_fn report_zones;
206 dm_busy_fn busy;
207 dm_iterate_devices_fn iterate_devices;
208 dm_io_hints_fn io_hints;
209 dm_dax_direct_access_fn direct_access;
210 dm_dax_zero_page_range_fn dax_zero_page_range;
211 dm_dax_recovery_write_fn dax_recovery_write;
212
213 /* For internal device-mapper use. */
214 struct list_head list;
215 };
216
217 /*
218 * Target features
219 */
220
221 /*
222 * Any table that contains an instance of this target must have only one.
223 */
224 #define DM_TARGET_SINGLETON 0x00000001
225 #define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
226
227 /*
228 * Indicates that a target does not support read-only devices.
229 */
230 #define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
231 #define dm_target_always_writeable(type) \
232 ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
233
234 /*
235 * Any device that contains a table with an instance of this target may never
236 * have tables containing any different target type.
237 */
238 #define DM_TARGET_IMMUTABLE 0x00000004
239 #define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
240
241 /*
242 * Indicates that a target may replace any target; even immutable targets.
243 * .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined.
244 */
245 #define DM_TARGET_WILDCARD 0x00000008
246 #define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD)
247
248 /*
249 * A target implements own bio data integrity.
250 */
251 #define DM_TARGET_INTEGRITY 0x00000010
252 #define dm_target_has_integrity(type) ((type)->features & DM_TARGET_INTEGRITY)
253
254 /*
255 * A target passes integrity data to the lower device.
256 */
257 #define DM_TARGET_PASSES_INTEGRITY 0x00000020
258 #define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY)
259
260 /*
261 * Indicates support for zoned block devices:
262 * - DM_TARGET_ZONED_HM: the target also supports host-managed zoned
263 * block devices but does not support combining different zoned models.
264 * - DM_TARGET_MIXED_ZONED_MODEL: the target supports combining multiple
265 * devices with different zoned models.
266 */
267 #ifdef CONFIG_BLK_DEV_ZONED
268 #define DM_TARGET_ZONED_HM 0x00000040
269 #define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)
270 #else
271 #define DM_TARGET_ZONED_HM 0x00000000
272 #define dm_target_supports_zoned_hm(type) (false)
273 #endif
274
275 /*
276 * A target handles REQ_NOWAIT
277 */
278 #define DM_TARGET_NOWAIT 0x00000080
279 #define dm_target_supports_nowait(type) ((type)->features & DM_TARGET_NOWAIT)
280
281 /*
282 * A target supports passing through inline crypto support.
283 */
284 #define DM_TARGET_PASSES_CRYPTO 0x00000100
285 #define dm_target_passes_crypto(type) ((type)->features & DM_TARGET_PASSES_CRYPTO)
286
287 #ifdef CONFIG_BLK_DEV_ZONED
288 #define DM_TARGET_MIXED_ZONED_MODEL 0x00000200
289 #define dm_target_supports_mixed_zoned_model(type) \
290 ((type)->features & DM_TARGET_MIXED_ZONED_MODEL)
291 #else
292 #define DM_TARGET_MIXED_ZONED_MODEL 0x00000000
293 #define dm_target_supports_mixed_zoned_model(type) (false)
294 #endif
295
296 struct dm_target {
297 struct dm_table *table;
298 struct target_type *type;
299
300 /* target limits */
301 sector_t begin;
302 sector_t len;
303
304 /* If non-zero, maximum size of I/O submitted to a target. */
305 uint32_t max_io_len;
306
307 /*
308 * A number of zero-length barrier bios that will be submitted
309 * to the target for the purpose of flushing cache.
310 *
311 * The bio number can be accessed with dm_bio_get_target_bio_nr.
312 * It is a responsibility of the target driver to remap these bios
313 * to the real underlying devices.
314 */
315 unsigned int num_flush_bios;
316
317 /*
318 * The number of discard bios that will be submitted to the target.
319 * The bio number can be accessed with dm_bio_get_target_bio_nr.
320 */
321 unsigned int num_discard_bios;
322
323 /*
324 * The number of secure erase bios that will be submitted to the target.
325 * The bio number can be accessed with dm_bio_get_target_bio_nr.
326 */
327 unsigned int num_secure_erase_bios;
328
329 /*
330 * The number of WRITE ZEROES bios that will be submitted to the target.
331 * The bio number can be accessed with dm_bio_get_target_bio_nr.
332 */
333 unsigned int num_write_zeroes_bios;
334
335 /*
336 * The minimum number of extra bytes allocated in each io for the
337 * target to use.
338 */
339 unsigned int per_io_data_size;
340
341 /* target specific data */
342 void *private;
343
344 /* Used to provide an error string from the ctr */
345 char *error;
346
347 /*
348 * Set if this target needs to receive flushes regardless of
349 * whether or not its underlying devices have support.
350 */
351 bool flush_supported:1;
352
353 /*
354 * Set if this target needs to receive discards regardless of
355 * whether or not its underlying devices have support.
356 */
357 bool discards_supported:1;
358
359 /*
360 * Set if this target requires that discards be split on
361 * 'max_discard_sectors' boundaries.
362 */
363 bool max_discard_granularity:1;
364
365 /*
366 * Set if this target requires that secure_erases be split on
367 * 'max_secure_erase_sectors' boundaries.
368 */
369 bool max_secure_erase_granularity:1;
370
371 /*
372 * Set if this target requires that write_zeroes be split on
373 * 'max_write_zeroes_sectors' boundaries.
374 */
375 bool max_write_zeroes_granularity:1;
376
377 /*
378 * Set if we need to limit the number of in-flight bios when swapping.
379 */
380 bool limit_swap_bios:1;
381
382 /*
383 * Set if this target implements a zoned device and needs emulation of
384 * zone append operations using regular writes.
385 */
386 bool emulate_zone_append:1;
387
388 /*
389 * Set if the target will submit IO using dm_submit_bio_remap()
390 * after returning DM_MAPIO_SUBMITTED from its map function.
391 */
392 bool accounts_remapped_io:1;
393
394 /*
395 * Set if the target will submit the DM bio without first calling
396 * bio_set_dev(). NOTE: ideally a target should _not_ need this.
397 */
398 bool needs_bio_set_dev:1;
399 };
400
401 void *dm_per_bio_data(struct bio *bio, size_t data_size);
402 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
403 unsigned int dm_bio_get_target_bio_nr(const struct bio *bio);
404
405 u64 dm_start_time_ns_from_clone(struct bio *bio);
406
407 int dm_register_target(struct target_type *t);
408 void dm_unregister_target(struct target_type *t);
409
410 /*
411 * Target argument parsing.
412 */
413 struct dm_arg_set {
414 unsigned int argc;
415 char **argv;
416 };
417
418 /*
419 * The minimum and maximum value of a numeric argument, together with
420 * the error message to use if the number is found to be outside that range.
421 */
422 struct dm_arg {
423 unsigned int min;
424 unsigned int max;
425 char *error;
426 };
427
428 /*
429 * Validate the next argument, either returning it as *value or, if invalid,
430 * returning -EINVAL and setting *error.
431 */
432 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
433 unsigned int *value, char **error);
434
435 /*
436 * Process the next argument as the start of a group containing between
437 * arg->min and arg->max further arguments. Either return the size as
438 * *num_args or, if invalid, return -EINVAL and set *error.
439 */
440 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
441 unsigned int *num_args, char **error);
442
443 /*
444 * Return the current argument and shift to the next.
445 */
446 const char *dm_shift_arg(struct dm_arg_set *as);
447
448 /*
449 * Move through num_args arguments.
450 */
451 void dm_consume_args(struct dm_arg_set *as, unsigned int num_args);
452
453 /*
454 *----------------------------------------------------------------
455 * Functions for creating and manipulating mapped devices.
456 * Drop the reference with dm_put when you finish with the object.
457 *----------------------------------------------------------------
458 */
459
460 /*
461 * DM_ANY_MINOR chooses the next available minor number.
462 */
463 #define DM_ANY_MINOR (-1)
464 int dm_create(int minor, struct mapped_device **md);
465
466 /*
467 * Reference counting for md.
468 */
469 struct mapped_device *dm_get_md(dev_t dev);
470 void dm_get(struct mapped_device *md);
471 int dm_hold(struct mapped_device *md);
472 void dm_put(struct mapped_device *md);
473
474 /*
475 * An arbitrary pointer may be stored alongside a mapped device.
476 */
477 void dm_set_mdptr(struct mapped_device *md, void *ptr);
478 void *dm_get_mdptr(struct mapped_device *md);
479
480 /*
481 * A device can still be used while suspended, but I/O is deferred.
482 */
483 int dm_suspend(struct mapped_device *md, unsigned int suspend_flags);
484 int dm_resume(struct mapped_device *md);
485
486 /*
487 * Event functions.
488 */
489 uint32_t dm_get_event_nr(struct mapped_device *md);
490 int dm_wait_event(struct mapped_device *md, int event_nr);
491 uint32_t dm_next_uevent_seq(struct mapped_device *md);
492 void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
493
494 /*
495 * Info functions.
496 */
497 const char *dm_device_name(struct mapped_device *md);
498 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
499 struct gendisk *dm_disk(struct mapped_device *md);
500 int dm_suspended(struct dm_target *ti);
501 int dm_post_suspending(struct dm_target *ti);
502 int dm_noflush_suspending(struct dm_target *ti);
503 void dm_accept_partial_bio(struct bio *bio, unsigned int n_sectors);
504 void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone);
505 union map_info *dm_get_rq_mapinfo(struct request *rq);
506
507 #ifdef CONFIG_BLK_DEV_ZONED
508 struct dm_report_zones_args {
509 struct dm_target *tgt;
510 sector_t next_sector;
511
512 void *orig_data;
513 report_zones_cb orig_cb;
514 unsigned int zone_idx;
515
516 /* must be filled by ->report_zones before calling dm_report_zones_cb */
517 sector_t start;
518 };
519 int dm_report_zones(struct block_device *bdev, sector_t start, sector_t sector,
520 struct dm_report_zones_args *args, unsigned int nr_zones);
521 #endif /* CONFIG_BLK_DEV_ZONED */
522
523 /*
524 * Device mapper functions to parse and create devices specified by the
525 * parameter "dm-mod.create="
526 */
527 int __init dm_early_create(struct dm_ioctl *dmi,
528 struct dm_target_spec **spec_array,
529 char **target_params_array);
530
531 /*
532 * Geometry functions.
533 */
534 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
535 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
536
537 /*
538 *---------------------------------------------------------------
539 * Functions for manipulating device-mapper tables.
540 *---------------------------------------------------------------
541 */
542
543 /*
544 * First create an empty table.
545 */
546 int dm_table_create(struct dm_table **result, blk_mode_t mode,
547 unsigned int num_targets, struct mapped_device *md);
548
549 /*
550 * Then call this once for each target.
551 */
552 int dm_table_add_target(struct dm_table *t, const char *type,
553 sector_t start, sector_t len, char *params);
554
555 /*
556 * Target can use this to set the table's type.
557 * Can only ever be called from a target's ctr.
558 * Useful for "hybrid" target (supports both bio-based
559 * and request-based).
560 */
561 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type);
562
563 /*
564 * Finally call this to make the table ready for use.
565 */
566 int dm_table_complete(struct dm_table *t);
567
568 /*
569 * Destroy the table when finished.
570 */
571 void dm_table_destroy(struct dm_table *t);
572
573 /*
574 * Target may require that it is never sent I/O larger than len.
575 */
576 int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
577
578 /*
579 * Table reference counting.
580 */
581 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);
582 void dm_put_live_table(struct mapped_device *md, int srcu_idx);
583 void dm_sync_table(struct mapped_device *md);
584
585 /*
586 * Queries
587 */
588 sector_t dm_table_get_size(struct dm_table *t);
589 blk_mode_t dm_table_get_mode(struct dm_table *t);
590 struct mapped_device *dm_table_get_md(struct dm_table *t);
591 const char *dm_table_device_name(struct dm_table *t);
592
593 /*
594 * Trigger an event.
595 */
596 void dm_table_event(struct dm_table *t);
597
598 /*
599 * Run the queue for request-based targets.
600 */
601 void dm_table_run_md_queue_async(struct dm_table *t);
602
603 /*
604 * The device must be suspended before calling this method.
605 * Returns the previous table, which the caller must destroy.
606 */
607 struct dm_table *dm_swap_table(struct mapped_device *md,
608 struct dm_table *t);
609
610 /*
611 * Table blk_crypto_profile functions
612 */
613 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile);
614
615 /*
616 *---------------------------------------------------------------
617 * Macros.
618 *---------------------------------------------------------------
619 */
620 #define DM_NAME "device-mapper"
621
622 #define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"
623
624 #define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)
625
626 #define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)
627 #define DMERR_LIMIT(fmt, ...) pr_err_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
628 #define DMWARN(fmt, ...) pr_warn(DM_FMT(fmt), ##__VA_ARGS__)
629 #define DMWARN_LIMIT(fmt, ...) pr_warn_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
630 #define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)
631 #define DMINFO_LIMIT(fmt, ...) pr_info_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
632
633 #define DMDEBUG(fmt, ...) pr_debug(DM_FMT(fmt), ##__VA_ARGS__)
634 #define DMDEBUG_LIMIT(fmt, ...) pr_debug_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
635
636 #define DMEMIT(x...) (sz += ((sz >= maxlen) ? 0 : scnprintf(result + sz, maxlen - sz, x)))
637
638 #define DMEMIT_TARGET_NAME_VERSION(y) \
639 DMEMIT("target_name=%s,target_version=%u.%u.%u", \
640 (y)->name, (y)->version[0], (y)->version[1], (y)->version[2])
641
642 /**
643 * module_dm() - Helper macro for DM targets that don't do anything
644 * special in their module_init and module_exit.
645 * Each module may only use this macro once, and calling it replaces
646 * module_init() and module_exit().
647 *
648 * @name: DM target's name
649 */
650 #define module_dm(name) \
651 static int __init dm_##name##_init(void) \
652 { \
653 return dm_register_target(&(name##_target)); \
654 } \
655 module_init(dm_##name##_init) \
656 static void __exit dm_##name##_exit(void) \
657 { \
658 dm_unregister_target(&(name##_target)); \
659 } \
660 module_exit(dm_##name##_exit)
661
662 /*
663 * Definitions of return values from target end_io function.
664 */
665 #define DM_ENDIO_DONE 0
666 #define DM_ENDIO_INCOMPLETE 1
667 #define DM_ENDIO_REQUEUE 2
668 #define DM_ENDIO_DELAY_REQUEUE 3
669
670 /*
671 * Definitions of return values from target map function.
672 */
673 #define DM_MAPIO_SUBMITTED 0
674 #define DM_MAPIO_REMAPPED 1
675 #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
676 #define DM_MAPIO_DELAY_REQUEUE DM_ENDIO_DELAY_REQUEUE
677 #define DM_MAPIO_KILL 4
678
679 #define dm_sector_div64(x, y)( \
680 { \
681 u64 _res; \
682 (x) = div64_u64_rem(x, y, &_res); \
683 _res; \
684 } \
685 )
686
687 /*
688 * Ceiling(n / sz)
689 */
690 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
691
692 #define dm_sector_div_up(n, sz) ( \
693 { \
694 sector_t _r = ((n) + (sz) - 1); \
695 sector_div(_r, (sz)); \
696 _r; \
697 } \
698 )
699
700 /*
701 * ceiling(n / size) * size
702 */
703 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
704
705 /*
706 * Sector offset taken relative to the start of the target instead of
707 * relative to the start of the device.
708 */
709 #define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
710
to_sector(unsigned long long n)711 static inline sector_t to_sector(unsigned long long n)
712 {
713 return (n >> SECTOR_SHIFT);
714 }
715
to_bytes(sector_t n)716 static inline unsigned long to_bytes(sector_t n)
717 {
718 return (n << SECTOR_SHIFT);
719 }
720
721 #endif /* _LINUX_DEVICE_MAPPER_H */
722