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 struct dm_target {
303 struct dm_table *table;
304 struct target_type *type;
305
306 /* target limits */
307 sector_t begin;
308 sector_t len;
309
310 /* If non-zero, maximum size of I/O submitted to a target. */
311 uint32_t max_io_len;
312
313 /*
314 * A number of zero-length barrier bios that will be submitted
315 * to the target for the purpose of flushing cache.
316 *
317 * The bio number can be accessed with dm_bio_get_target_bio_nr.
318 * It is a responsibility of the target driver to remap these bios
319 * to the real underlying devices.
320 */
321 unsigned int num_flush_bios;
322
323 /*
324 * The number of discard 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_discard_bios;
328
329 /*
330 * The number of secure erase 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_secure_erase_bios;
334
335 /*
336 * The number of WRITE ZEROES bios that will be submitted to the target.
337 * The bio number can be accessed with dm_bio_get_target_bio_nr.
338 */
339 unsigned int num_write_zeroes_bios;
340
341 /*
342 * The minimum number of extra bytes allocated in each io for the
343 * target to use.
344 */
345 unsigned int per_io_data_size;
346
347 /* target specific data */
348 void *private;
349
350 /* Used to provide an error string from the ctr */
351 char *error;
352
353 /*
354 * Set if this target needs to receive flushes regardless of
355 * whether or not its underlying devices have support.
356 */
357 bool flush_supported:1;
358
359 /*
360 * Set if this target needs to receive discards regardless of
361 * whether or not its underlying devices have support.
362 */
363 bool discards_supported:1;
364
365 /*
366 * Automatically set by dm-core if this target supports
367 * REQ_OP_ZONE_RESET_ALL. Otherwise, this operation will be emulated
368 * using REQ_OP_ZONE_RESET. Target drivers must not set this manually.
369 */
370 bool zone_reset_all_supported:1;
371
372 /*
373 * Set if this target requires that discards be split on
374 * 'max_discard_sectors' boundaries.
375 */
376 bool max_discard_granularity:1;
377
378 /*
379 * Set if we need to limit the number of in-flight bios when swapping.
380 */
381 bool limit_swap_bios:1;
382
383 /*
384 * Set if this target implements a zoned device and needs emulation of
385 * zone append operations using regular writes.
386 */
387 bool emulate_zone_append:1;
388
389 /*
390 * Set if the target will submit IO using dm_submit_bio_remap()
391 * after returning DM_MAPIO_SUBMITTED from its map function.
392 */
393 bool accounts_remapped_io:1;
394
395 /*
396 * Set if the target will submit the DM bio without first calling
397 * bio_set_dev(). NOTE: ideally a target should _not_ need this.
398 */
399 bool needs_bio_set_dev:1;
400
401 /*
402 * Set if the target supports flush optimization. If all the targets in
403 * a table have flush_bypasses_map set, the dm core will not send
404 * flushes to the targets via a ->map method. It will iterate over
405 * dm_table->devices and send flushes to the devices directly. This
406 * optimization reduces the number of flushes being sent when multiple
407 * targets in a table use the same underlying device.
408 *
409 * This optimization may be enabled on targets that just pass the
410 * flushes to the underlying devices without performing any other
411 * actions on the flush request. Currently, dm-linear and dm-stripe
412 * support it.
413 */
414 bool flush_bypasses_map:1;
415
416 /*
417 * Set if the target calls bio_integrity_alloc on bios received
418 * in the map method.
419 */
420 bool mempool_needs_integrity:1;
421 };
422
423 void *dm_per_bio_data(struct bio *bio, size_t data_size);
424 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
425 unsigned int dm_bio_get_target_bio_nr(const struct bio *bio);
426
427 u64 dm_start_time_ns_from_clone(struct bio *bio);
428
429 int dm_register_target(struct target_type *t);
430 void dm_unregister_target(struct target_type *t);
431
432 /*
433 * Target argument parsing.
434 */
435 struct dm_arg_set {
436 unsigned int argc;
437 char **argv;
438 };
439
440 /*
441 * The minimum and maximum value of a numeric argument, together with
442 * the error message to use if the number is found to be outside that range.
443 */
444 struct dm_arg {
445 unsigned int min;
446 unsigned int max;
447 char *error;
448 };
449
450 /*
451 * Validate the next argument, either returning it as *value or, if invalid,
452 * returning -EINVAL and setting *error.
453 */
454 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
455 unsigned int *value, char **error);
456
457 /*
458 * Process the next argument as the start of a group containing between
459 * arg->min and arg->max further arguments. Either return the size as
460 * *num_args or, if invalid, return -EINVAL and set *error.
461 */
462 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
463 unsigned int *num_args, char **error);
464
465 /*
466 * Return the current argument and shift to the next.
467 */
468 const char *dm_shift_arg(struct dm_arg_set *as);
469
470 /*
471 * Move through num_args arguments.
472 */
473 void dm_consume_args(struct dm_arg_set *as, unsigned int num_args);
474
475 /*
476 *----------------------------------------------------------------
477 * Functions for creating and manipulating mapped devices.
478 * Drop the reference with dm_put when you finish with the object.
479 *----------------------------------------------------------------
480 */
481
482 /*
483 * DM_ANY_MINOR chooses the next available minor number.
484 */
485 #define DM_ANY_MINOR (-1)
486 int dm_create(int minor, struct mapped_device **md);
487
488 /*
489 * Reference counting for md.
490 */
491 struct mapped_device *dm_get_md(dev_t dev);
492 void dm_get(struct mapped_device *md);
493 int dm_hold(struct mapped_device *md);
494 void dm_put(struct mapped_device *md);
495
496 /*
497 * An arbitrary pointer may be stored alongside a mapped device.
498 */
499 void dm_set_mdptr(struct mapped_device *md, void *ptr);
500 void *dm_get_mdptr(struct mapped_device *md);
501
502 /*
503 * A device can still be used while suspended, but I/O is deferred.
504 */
505 int dm_suspend(struct mapped_device *md, unsigned int suspend_flags);
506 int dm_resume(struct mapped_device *md);
507
508 /*
509 * Event functions.
510 */
511 uint32_t dm_get_event_nr(struct mapped_device *md);
512 int dm_wait_event(struct mapped_device *md, int event_nr);
513 uint32_t dm_next_uevent_seq(struct mapped_device *md);
514 void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
515
516 /*
517 * Info functions.
518 */
519 const char *dm_device_name(struct mapped_device *md);
520 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
521 struct gendisk *dm_disk(struct mapped_device *md);
522 int dm_suspended(struct dm_target *ti);
523 int dm_post_suspending(struct dm_target *ti);
524 int dm_noflush_suspending(struct dm_target *ti);
525 void dm_accept_partial_bio(struct bio *bio, unsigned int n_sectors);
526 void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone);
527 union map_info *dm_get_rq_mapinfo(struct request *rq);
528
529 #ifdef CONFIG_BLK_DEV_ZONED
530 struct dm_report_zones_args {
531 struct dm_target *tgt;
532 sector_t next_sector;
533
534 void *orig_data;
535 report_zones_cb orig_cb;
536 unsigned int zone_idx;
537
538 /* must be filled by ->report_zones before calling dm_report_zones_cb */
539 sector_t start;
540 };
541 int dm_report_zones(struct block_device *bdev, sector_t start, sector_t sector,
542 struct dm_report_zones_args *args, unsigned int nr_zones);
543 #endif /* CONFIG_BLK_DEV_ZONED */
544
545 /*
546 * Device mapper functions to parse and create devices specified by the
547 * parameter "dm-mod.create="
548 */
549 int __init dm_early_create(struct dm_ioctl *dmi,
550 struct dm_target_spec **spec_array,
551 char **target_params_array);
552
553 /*
554 * Geometry functions.
555 */
556 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
557 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
558
559 /*
560 *---------------------------------------------------------------
561 * Functions for manipulating device-mapper tables.
562 *---------------------------------------------------------------
563 */
564
565 /*
566 * First create an empty table.
567 */
568 int dm_table_create(struct dm_table **result, blk_mode_t mode,
569 unsigned int num_targets, struct mapped_device *md);
570
571 /*
572 * Then call this once for each target.
573 */
574 int dm_table_add_target(struct dm_table *t, const char *type,
575 sector_t start, sector_t len, char *params);
576
577 /*
578 * Target can use this to set the table's type.
579 * Can only ever be called from a target's ctr.
580 * Useful for "hybrid" target (supports both bio-based
581 * and request-based).
582 */
583 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type);
584
585 /*
586 * Finally call this to make the table ready for use.
587 */
588 int dm_table_complete(struct dm_table *t);
589
590 /*
591 * Destroy the table when finished.
592 */
593 void dm_table_destroy(struct dm_table *t);
594
595 /*
596 * Target may require that it is never sent I/O larger than len.
597 */
598 int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
599
600 /*
601 * Table reference counting.
602 */
603 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);
604 void dm_put_live_table(struct mapped_device *md, int srcu_idx);
605 void dm_sync_table(struct mapped_device *md);
606
607 /*
608 * Queries
609 */
610 sector_t dm_table_get_size(struct dm_table *t);
611 blk_mode_t dm_table_get_mode(struct dm_table *t);
612 struct mapped_device *dm_table_get_md(struct dm_table *t);
613 const char *dm_table_device_name(struct dm_table *t);
614
615 /*
616 * Trigger an event.
617 */
618 void dm_table_event(struct dm_table *t);
619
620 /*
621 * Run the queue for request-based targets.
622 */
623 void dm_table_run_md_queue_async(struct dm_table *t);
624
625 /*
626 * The device must be suspended before calling this method.
627 * Returns the previous table, which the caller must destroy.
628 */
629 struct dm_table *dm_swap_table(struct mapped_device *md,
630 struct dm_table *t);
631
632 /*
633 * Table blk_crypto_profile functions
634 */
635 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile);
636
637 /*
638 *---------------------------------------------------------------
639 * Macros.
640 *---------------------------------------------------------------
641 */
642 #define DM_NAME "device-mapper"
643
644 #define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"
645
646 #define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)
647
648 #define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)
649 #define DMERR_LIMIT(fmt, ...) pr_err_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
650 #define DMWARN(fmt, ...) pr_warn(DM_FMT(fmt), ##__VA_ARGS__)
651 #define DMWARN_LIMIT(fmt, ...) pr_warn_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
652 #define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)
653 #define DMINFO_LIMIT(fmt, ...) pr_info_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
654
655 #define DMDEBUG(fmt, ...) pr_debug(DM_FMT(fmt), ##__VA_ARGS__)
656 #define DMDEBUG_LIMIT(fmt, ...) pr_debug_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
657
658 #define DMEMIT(x...) (sz += ((sz >= maxlen) ? 0 : scnprintf(result + sz, maxlen - sz, x)))
659
660 #define DMEMIT_TARGET_NAME_VERSION(y) \
661 DMEMIT("target_name=%s,target_version=%u.%u.%u", \
662 (y)->name, (y)->version[0], (y)->version[1], (y)->version[2])
663
664 /**
665 * module_dm() - Helper macro for DM targets that don't do anything
666 * special in their module_init and module_exit.
667 * Each module may only use this macro once, and calling it replaces
668 * module_init() and module_exit().
669 *
670 * @name: DM target's name
671 */
672 #define module_dm(name) \
673 static int __init dm_##name##_init(void) \
674 { \
675 return dm_register_target(&(name##_target)); \
676 } \
677 module_init(dm_##name##_init) \
678 static void __exit dm_##name##_exit(void) \
679 { \
680 dm_unregister_target(&(name##_target)); \
681 } \
682 module_exit(dm_##name##_exit)
683
684 /*
685 * Definitions of return values from target end_io function.
686 */
687 #define DM_ENDIO_DONE 0
688 #define DM_ENDIO_INCOMPLETE 1
689 #define DM_ENDIO_REQUEUE 2
690 #define DM_ENDIO_DELAY_REQUEUE 3
691
692 /*
693 * Definitions of return values from target map function.
694 */
695 #define DM_MAPIO_SUBMITTED 0
696 #define DM_MAPIO_REMAPPED 1
697 #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
698 #define DM_MAPIO_DELAY_REQUEUE DM_ENDIO_DELAY_REQUEUE
699 #define DM_MAPIO_KILL 4
700
701 #define dm_sector_div64(x, y)( \
702 { \
703 u64 _res; \
704 (x) = div64_u64_rem(x, y, &_res); \
705 _res; \
706 } \
707 )
708
709 /*
710 * Ceiling(n / sz)
711 */
712 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
713
714 #define dm_sector_div_up(n, sz) ( \
715 { \
716 sector_t _r = ((n) + (sz) - 1); \
717 sector_div(_r, (sz)); \
718 _r; \
719 } \
720 )
721
722 /*
723 * ceiling(n / size) * size
724 */
725 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
726
727 /*
728 * Sector offset taken relative to the start of the target instead of
729 * relative to the start of the device.
730 */
731 #define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
732
to_sector(unsigned long long n)733 static inline sector_t to_sector(unsigned long long n)
734 {
735 return (n >> SECTOR_SHIFT);
736 }
737
to_bytes(sector_t n)738 static inline unsigned long to_bytes(sector_t n)
739 {
740 return (n << SECTOR_SHIFT);
741 }
742
743 #endif /* _LINUX_DEVICE_MAPPER_H */
744