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