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 file *bdev_file;
169 struct dax_device *dax_dev;
170 blk_mode_t mode;
171 char name[16];
172 };
173
174 /*
175 * Constructors should call these functions to ensure destination devices
176 * are opened/closed correctly.
177 */
178 int dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode,
179 struct dm_dev **result);
180 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
181
182 /*
183 * Helper function for getting devices
184 */
185 int dm_devt_from_path(const char *path, dev_t *dev_p);
186
187 /*
188 * Information about a target type
189 */
190
191 struct target_type {
192 uint64_t features;
193 const char *name;
194 struct module *module;
195 unsigned int version[3];
196 dm_ctr_fn ctr;
197 dm_dtr_fn dtr;
198 dm_map_fn map;
199 dm_clone_and_map_request_fn clone_and_map_rq;
200 dm_release_clone_request_fn release_clone_rq;
201 dm_endio_fn end_io;
202 dm_request_endio_fn rq_end_io;
203 dm_presuspend_fn presuspend;
204 dm_presuspend_undo_fn presuspend_undo;
205 dm_postsuspend_fn postsuspend;
206 dm_preresume_fn preresume;
207 dm_resume_fn resume;
208 dm_status_fn status;
209 dm_message_fn message;
210 dm_prepare_ioctl_fn prepare_ioctl;
211 dm_report_zones_fn report_zones;
212 dm_busy_fn busy;
213 dm_iterate_devices_fn iterate_devices;
214 dm_io_hints_fn io_hints;
215 dm_dax_direct_access_fn direct_access;
216 dm_dax_zero_page_range_fn dax_zero_page_range;
217 dm_dax_recovery_write_fn dax_recovery_write;
218
219 /* For internal device-mapper use. */
220 struct list_head list;
221 };
222
223 /*
224 * Target features
225 */
226
227 /*
228 * Any table that contains an instance of this target must have only one.
229 */
230 #define DM_TARGET_SINGLETON 0x00000001
231 #define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
232
233 /*
234 * Indicates that a target does not support read-only devices.
235 */
236 #define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
237 #define dm_target_always_writeable(type) \
238 ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
239
240 /*
241 * Any device that contains a table with an instance of this target may never
242 * have tables containing any different target type.
243 */
244 #define DM_TARGET_IMMUTABLE 0x00000004
245 #define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
246
247 /*
248 * Indicates that a target may replace any target; even immutable targets.
249 * .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined.
250 */
251 #define DM_TARGET_WILDCARD 0x00000008
252 #define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD)
253
254 /*
255 * A target implements own bio data integrity.
256 */
257 #define DM_TARGET_INTEGRITY 0x00000010
258 #define dm_target_has_integrity(type) ((type)->features & DM_TARGET_INTEGRITY)
259
260 /*
261 * A target passes integrity data to the lower device.
262 */
263 #define DM_TARGET_PASSES_INTEGRITY 0x00000020
264 #define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY)
265
266 /*
267 * Indicates support for zoned block devices:
268 * - DM_TARGET_ZONED_HM: the target also supports host-managed zoned
269 * block devices but does not support combining different zoned models.
270 * - DM_TARGET_MIXED_ZONED_MODEL: the target supports combining multiple
271 * devices with different zoned models.
272 */
273 #ifdef CONFIG_BLK_DEV_ZONED
274 #define DM_TARGET_ZONED_HM 0x00000040
275 #define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)
276 #else
277 #define DM_TARGET_ZONED_HM 0x00000000
278 #define dm_target_supports_zoned_hm(type) (false)
279 #endif
280
281 /*
282 * A target handles REQ_NOWAIT
283 */
284 #define DM_TARGET_NOWAIT 0x00000080
285 #define dm_target_supports_nowait(type) ((type)->features & DM_TARGET_NOWAIT)
286
287 /*
288 * A target supports passing through inline crypto support.
289 */
290 #define DM_TARGET_PASSES_CRYPTO 0x00000100
291 #define dm_target_passes_crypto(type) ((type)->features & DM_TARGET_PASSES_CRYPTO)
292
293 #ifdef CONFIG_BLK_DEV_ZONED
294 #define DM_TARGET_MIXED_ZONED_MODEL 0x00000200
295 #define dm_target_supports_mixed_zoned_model(type) \
296 ((type)->features & DM_TARGET_MIXED_ZONED_MODEL)
297 #else
298 #define DM_TARGET_MIXED_ZONED_MODEL 0x00000000
299 #define dm_target_supports_mixed_zoned_model(type) (false)
300 #endif
301
302 #define DM_TARGET_ATOMIC_WRITES 0x00000400
303 #define dm_target_supports_atomic_writes(type) ((type)->features & DM_TARGET_ATOMIC_WRITES)
304
305 struct dm_target {
306 struct dm_table *table;
307 struct target_type *type;
308
309 /* target limits */
310 sector_t begin;
311 sector_t len;
312
313 /* If non-zero, maximum size of I/O submitted to a target. */
314 uint32_t max_io_len;
315
316 /*
317 * A number of zero-length barrier bios that will be submitted
318 * to the target for the purpose of flushing cache.
319 *
320 * The bio number can be accessed with dm_bio_get_target_bio_nr.
321 * It is a responsibility of the target driver to remap these bios
322 * to the real underlying devices.
323 */
324 unsigned int num_flush_bios;
325
326 /*
327 * The number of discard bios that will be submitted to the target.
328 * The bio number can be accessed with dm_bio_get_target_bio_nr.
329 */
330 unsigned int num_discard_bios;
331
332 /*
333 * The number of secure erase bios that will be submitted to the target.
334 * The bio number can be accessed with dm_bio_get_target_bio_nr.
335 */
336 unsigned int num_secure_erase_bios;
337
338 /*
339 * The number of WRITE ZEROES bios that will be submitted to the target.
340 * The bio number can be accessed with dm_bio_get_target_bio_nr.
341 */
342 unsigned int num_write_zeroes_bios;
343
344 /*
345 * The minimum number of extra bytes allocated in each io for the
346 * target to use.
347 */
348 unsigned int per_io_data_size;
349
350 /* target specific data */
351 void *private;
352
353 /* Used to provide an error string from the ctr */
354 char *error;
355
356 /*
357 * Set if this target needs to receive flushes regardless of
358 * whether or not its underlying devices have support.
359 */
360 bool flush_supported:1;
361
362 /*
363 * Set if this target needs to receive discards regardless of
364 * whether or not its underlying devices have support.
365 */
366 bool discards_supported:1;
367
368 /*
369 * Automatically set by dm-core if this target supports
370 * REQ_OP_ZONE_RESET_ALL. Otherwise, this operation will be emulated
371 * using REQ_OP_ZONE_RESET. Target drivers must not set this manually.
372 */
373 bool zone_reset_all_supported:1;
374
375 /*
376 * Set if this target requires that discards be split on
377 * 'max_discard_sectors' boundaries.
378 */
379 bool max_discard_granularity:1;
380
381 /*
382 * Set if we need to limit the number of in-flight bios when swapping.
383 */
384 bool limit_swap_bios:1;
385
386 /*
387 * Set if this target implements a zoned device and needs emulation of
388 * zone append operations using regular writes.
389 */
390 bool emulate_zone_append:1;
391
392 /*
393 * Set if the target will submit IO using dm_submit_bio_remap()
394 * after returning DM_MAPIO_SUBMITTED from its map function.
395 */
396 bool accounts_remapped_io:1;
397
398 /*
399 * Set if the target will submit the DM bio without first calling
400 * bio_set_dev(). NOTE: ideally a target should _not_ need this.
401 */
402 bool needs_bio_set_dev:1;
403
404 /*
405 * Set if the target supports flush optimization. If all the targets in
406 * a table have flush_bypasses_map set, the dm core will not send
407 * flushes to the targets via a ->map method. It will iterate over
408 * dm_table->devices and send flushes to the devices directly. This
409 * optimization reduces the number of flushes being sent when multiple
410 * targets in a table use the same underlying device.
411 *
412 * This optimization may be enabled on targets that just pass the
413 * flushes to the underlying devices without performing any other
414 * actions on the flush request. Currently, dm-linear and dm-stripe
415 * support it.
416 */
417 bool flush_bypasses_map:1;
418
419 /*
420 * Set if the target calls bio_integrity_alloc on bios received
421 * in the map method.
422 */
423 bool mempool_needs_integrity:1;
424 };
425
426 void *dm_per_bio_data(struct bio *bio, size_t data_size);
427 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
428 unsigned int dm_bio_get_target_bio_nr(const struct bio *bio);
429
430 u64 dm_start_time_ns_from_clone(struct bio *bio);
431
432 int dm_register_target(struct target_type *t);
433 void dm_unregister_target(struct target_type *t);
434
435 /*
436 * Target argument parsing.
437 */
438 struct dm_arg_set {
439 unsigned int argc;
440 char **argv;
441 };
442
443 /*
444 * The minimum and maximum value of a numeric argument, together with
445 * the error message to use if the number is found to be outside that range.
446 */
447 struct dm_arg {
448 unsigned int min;
449 unsigned int max;
450 char *error;
451 };
452
453 /*
454 * Validate the next argument, either returning it as *value or, if invalid,
455 * returning -EINVAL and setting *error.
456 */
457 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
458 unsigned int *value, char **error);
459
460 /*
461 * Process the next argument as the start of a group containing between
462 * arg->min and arg->max further arguments. Either return the size as
463 * *num_args or, if invalid, return -EINVAL and set *error.
464 */
465 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
466 unsigned int *num_args, char **error);
467
468 /*
469 * Return the current argument and shift to the next.
470 */
471 const char *dm_shift_arg(struct dm_arg_set *as);
472
473 /*
474 * Move through num_args arguments.
475 */
476 void dm_consume_args(struct dm_arg_set *as, unsigned int num_args);
477
478 /*
479 *----------------------------------------------------------------
480 * Functions for creating and manipulating mapped devices.
481 * Drop the reference with dm_put when you finish with the object.
482 *----------------------------------------------------------------
483 */
484
485 /*
486 * DM_ANY_MINOR chooses the next available minor number.
487 */
488 #define DM_ANY_MINOR (-1)
489 int dm_create(int minor, struct mapped_device **md);
490
491 /*
492 * Reference counting for md.
493 */
494 struct mapped_device *dm_get_md(dev_t dev);
495 void dm_get(struct mapped_device *md);
496 int dm_hold(struct mapped_device *md);
497 void dm_put(struct mapped_device *md);
498
499 /*
500 * An arbitrary pointer may be stored alongside a mapped device.
501 */
502 void dm_set_mdptr(struct mapped_device *md, void *ptr);
503 void *dm_get_mdptr(struct mapped_device *md);
504
505 /*
506 * A device can still be used while suspended, but I/O is deferred.
507 */
508 int dm_suspend(struct mapped_device *md, unsigned int suspend_flags);
509 int dm_resume(struct mapped_device *md);
510
511 /*
512 * Event functions.
513 */
514 uint32_t dm_get_event_nr(struct mapped_device *md);
515 int dm_wait_event(struct mapped_device *md, int event_nr);
516 uint32_t dm_next_uevent_seq(struct mapped_device *md);
517 void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
518
519 /*
520 * Info functions.
521 */
522 const char *dm_device_name(struct mapped_device *md);
523 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
524 struct gendisk *dm_disk(struct mapped_device *md);
525 int dm_suspended(struct dm_target *ti);
526 int dm_post_suspending(struct dm_target *ti);
527 int dm_noflush_suspending(struct dm_target *ti);
528 void dm_accept_partial_bio(struct bio *bio, unsigned int n_sectors);
529 void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone);
530
531 #ifdef CONFIG_BLK_DEV_ZONED
532 struct dm_report_zones_args {
533 struct dm_target *tgt;
534 sector_t next_sector;
535
536 void *orig_data;
537 report_zones_cb orig_cb;
538 unsigned int zone_idx;
539
540 /* must be filled by ->report_zones before calling dm_report_zones_cb */
541 sector_t start;
542 };
543 int dm_report_zones(struct block_device *bdev, sector_t start, sector_t sector,
544 struct dm_report_zones_args *args, unsigned int nr_zones);
545 #endif /* CONFIG_BLK_DEV_ZONED */
546
547 /*
548 * Device mapper functions to parse and create devices specified by the
549 * parameter "dm-mod.create="
550 */
551 int __init dm_early_create(struct dm_ioctl *dmi,
552 struct dm_target_spec **spec_array,
553 char **target_params_array);
554
555 /*
556 * Geometry functions.
557 */
558 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
559 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
560
561 /*
562 *---------------------------------------------------------------
563 * Functions for manipulating device-mapper tables.
564 *---------------------------------------------------------------
565 */
566
567 /*
568 * First create an empty table.
569 */
570 int dm_table_create(struct dm_table **result, blk_mode_t mode,
571 unsigned int num_targets, struct mapped_device *md);
572
573 /*
574 * Then call this once for each target.
575 */
576 int dm_table_add_target(struct dm_table *t, const char *type,
577 sector_t start, sector_t len, char *params);
578
579 /*
580 * Target can use this to set the table's type.
581 * Can only ever be called from a target's ctr.
582 * Useful for "hybrid" target (supports both bio-based
583 * and request-based).
584 */
585 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type);
586
587 /*
588 * Finally call this to make the table ready for use.
589 */
590 int dm_table_complete(struct dm_table *t);
591
592 /*
593 * Destroy the table when finished.
594 */
595 void dm_table_destroy(struct dm_table *t);
596
597 /*
598 * Target may require that it is never sent I/O larger than len.
599 */
600 int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
601
602 /*
603 * Table reference counting.
604 */
605 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);
606 void dm_put_live_table(struct mapped_device *md, int srcu_idx);
607 void dm_sync_table(struct mapped_device *md);
608
609 /*
610 * Queries
611 */
612 sector_t dm_table_get_size(struct dm_table *t);
613 blk_mode_t dm_table_get_mode(struct dm_table *t);
614 struct mapped_device *dm_table_get_md(struct dm_table *t);
615 const char *dm_table_device_name(struct dm_table *t);
616
617 /*
618 * Trigger an event.
619 */
620 void dm_table_event(struct dm_table *t);
621
622 /*
623 * Run the queue for request-based targets.
624 */
625 void dm_table_run_md_queue_async(struct dm_table *t);
626
627 /*
628 * The device must be suspended before calling this method.
629 * Returns the previous table, which the caller must destroy.
630 */
631 struct dm_table *dm_swap_table(struct mapped_device *md,
632 struct dm_table *t);
633
634 /*
635 * Table blk_crypto_profile functions
636 */
637 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile);
638
639 /*
640 *---------------------------------------------------------------
641 * Macros.
642 *---------------------------------------------------------------
643 */
644 #define DM_NAME "device-mapper"
645
646 #define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"
647
648 #define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)
649
650 #define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)
651 #define DMERR_LIMIT(fmt, ...) pr_err_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
652 #define DMWARN(fmt, ...) pr_warn(DM_FMT(fmt), ##__VA_ARGS__)
653 #define DMWARN_LIMIT(fmt, ...) pr_warn_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
654 #define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)
655 #define DMINFO_LIMIT(fmt, ...) pr_info_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
656
657 #define DMDEBUG(fmt, ...) pr_debug(DM_FMT(fmt), ##__VA_ARGS__)
658 #define DMDEBUG_LIMIT(fmt, ...) pr_debug_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
659
660 #define DMEMIT(x...) (sz += ((sz >= maxlen) ? 0 : scnprintf(result + sz, maxlen - sz, x)))
661
662 #define DMEMIT_TARGET_NAME_VERSION(y) \
663 DMEMIT("target_name=%s,target_version=%u.%u.%u", \
664 (y)->name, (y)->version[0], (y)->version[1], (y)->version[2])
665
666 /**
667 * module_dm() - Helper macro for DM targets that don't do anything
668 * special in their module_init and module_exit.
669 * Each module may only use this macro once, and calling it replaces
670 * module_init() and module_exit().
671 *
672 * @name: DM target's name
673 */
674 #define module_dm(name) \
675 static int __init dm_##name##_init(void) \
676 { \
677 return dm_register_target(&(name##_target)); \
678 } \
679 module_init(dm_##name##_init) \
680 static void __exit dm_##name##_exit(void) \
681 { \
682 dm_unregister_target(&(name##_target)); \
683 } \
684 module_exit(dm_##name##_exit)
685
686 /*
687 * Definitions of return values from target end_io function.
688 */
689 #define DM_ENDIO_DONE 0
690 #define DM_ENDIO_INCOMPLETE 1
691 #define DM_ENDIO_REQUEUE 2
692 #define DM_ENDIO_DELAY_REQUEUE 3
693
694 /*
695 * Definitions of return values from target map function.
696 */
697 #define DM_MAPIO_SUBMITTED 0
698 #define DM_MAPIO_REMAPPED 1
699 #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
700 #define DM_MAPIO_DELAY_REQUEUE DM_ENDIO_DELAY_REQUEUE
701 #define DM_MAPIO_KILL 4
702
703 #define dm_sector_div64(x, y)( \
704 { \
705 u64 _res; \
706 (x) = div64_u64_rem(x, y, &_res); \
707 _res; \
708 } \
709 )
710
711 /*
712 * Ceiling(n / sz)
713 */
714 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
715
716 #define dm_sector_div_up(n, sz) ( \
717 { \
718 sector_t _r = ((n) + (sz) - 1); \
719 sector_div(_r, (sz)); \
720 _r; \
721 } \
722 )
723
724 /*
725 * ceiling(n / size) * size
726 */
727 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
728
729 /*
730 * Sector offset taken relative to the start of the target instead of
731 * relative to the start of the device.
732 */
733 #define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
734
to_sector(unsigned long long n)735 static inline sector_t to_sector(unsigned long long n)
736 {
737 return (n >> SECTOR_SHIFT);
738 }
739
to_bytes(sector_t n)740 static inline unsigned long to_bytes(sector_t n)
741 {
742 return (n << SECTOR_SHIFT);
743 }
744
745 #endif /* _LINUX_DEVICE_MAPPER_H */
746