2 * Copyright (C) 2001 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This file is released under the LGPL.
8 #ifndef _LINUX_DEVICE_MAPPER_H
9 #define _LINUX_DEVICE_MAPPER_H
11 #include <linux/bio.h>
12 #include <linux/blkdev.h>
13 #include <linux/dm-ioctl.h>
14 #include <linux/math64.h>
15 #include <linux/ratelimit.h>
20 struct dm_report_zones_args;
25 * Type of table, mapped_device's mempool and request_queue
29 DM_TYPE_BIO_BASED = 1,
30 DM_TYPE_REQUEST_BASED = 2,
31 DM_TYPE_DAX_BIO_BASED = 3,
32 DM_TYPE_NVME_BIO_BASED = 4,
35 typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
42 * In the constructor the target parameter will already have the
43 * table, type, begin and len fields filled in.
45 typedef int (*dm_ctr_fn) (struct dm_target *target,
46 unsigned int argc, char **argv);
49 * The destructor doesn't need to free the dm_target, just
50 * anything hidden ti->private.
52 typedef void (*dm_dtr_fn) (struct dm_target *ti);
55 * The map function must return:
57 * = 0: The target will handle the io by resubmitting it later
58 * = 1: simple remap complete
59 * = 2: The target wants to push back the io
61 typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio);
62 typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti,
64 union map_info *map_context,
65 struct request **clone);
66 typedef void (*dm_release_clone_request_fn) (struct request *clone,
67 union map_info *map_context);
71 * < 0 : error (currently ignored)
72 * 0 : ended successfully
73 * 1 : for some reason the io has still not completed (eg,
74 * multipath target might want to requeue a failed io).
75 * 2 : The target wants to push back the io
77 typedef int (*dm_endio_fn) (struct dm_target *ti,
78 struct bio *bio, blk_status_t *error);
79 typedef int (*dm_request_endio_fn) (struct dm_target *ti,
80 struct request *clone, blk_status_t error,
81 union map_info *map_context);
83 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
84 typedef void (*dm_presuspend_undo_fn) (struct dm_target *ti);
85 typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
86 typedef int (*dm_preresume_fn) (struct dm_target *ti);
87 typedef void (*dm_resume_fn) (struct dm_target *ti);
89 typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
90 unsigned status_flags, char *result, unsigned maxlen);
92 typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv,
93 char *result, unsigned maxlen);
95 typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti, struct block_device **bdev);
97 typedef int (*dm_report_zones_fn) (struct dm_target *ti,
98 struct dm_report_zones_args *args,
99 unsigned int nr_zones);
102 * These iteration functions are typically used to check (and combine)
103 * properties of underlying devices.
104 * E.g. Does at least one underlying device support flush?
105 * Does any underlying device not support WRITE_SAME?
107 * The callout function is called once for each contiguous section of
108 * an underlying device. State can be maintained in *data.
109 * Return non-zero to stop iterating through any further devices.
111 typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
113 sector_t start, sector_t len,
117 * This function must iterate through each section of device used by the
118 * target until it encounters a non-zero return code, which it then returns.
119 * Returns zero if no callout returned non-zero.
121 typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
122 iterate_devices_callout_fn fn,
125 typedef void (*dm_io_hints_fn) (struct dm_target *ti,
126 struct queue_limits *limits);
130 * 0: The target can handle the next I/O immediately.
131 * 1: The target can't handle the next I/O immediately.
133 typedef int (*dm_busy_fn) (struct dm_target *ti);
138 * >= 0 : the number of bytes accessible at the address
140 typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff,
141 long nr_pages, void **kaddr, pfn_t *pfn);
142 typedef size_t (*dm_dax_copy_iter_fn)(struct dm_target *ti, pgoff_t pgoff,
143 void *addr, size_t bytes, struct iov_iter *i);
144 typedef int (*dm_dax_zero_page_range_fn)(struct dm_target *ti, pgoff_t pgoff,
146 #define PAGE_SECTORS (PAGE_SIZE / 512)
148 void dm_error(const char *message);
151 struct block_device *bdev;
152 struct dax_device *dax_dev;
157 dev_t dm_get_dev_t(const char *path);
160 * Constructors should call these functions to ensure destination devices
161 * are opened/closed correctly.
163 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
164 struct dm_dev **result);
165 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
168 * Information about a target type
174 struct module *module;
179 dm_clone_and_map_request_fn clone_and_map_rq;
180 dm_release_clone_request_fn release_clone_rq;
182 dm_request_endio_fn rq_end_io;
183 dm_presuspend_fn presuspend;
184 dm_presuspend_undo_fn presuspend_undo;
185 dm_postsuspend_fn postsuspend;
186 dm_preresume_fn preresume;
189 dm_message_fn message;
190 dm_prepare_ioctl_fn prepare_ioctl;
191 #ifdef CONFIG_BLK_DEV_ZONED
192 dm_report_zones_fn report_zones;
195 dm_iterate_devices_fn iterate_devices;
196 dm_io_hints_fn io_hints;
197 dm_dax_direct_access_fn direct_access;
198 dm_dax_copy_iter_fn dax_copy_from_iter;
199 dm_dax_copy_iter_fn dax_copy_to_iter;
200 dm_dax_zero_page_range_fn dax_zero_page_range;
202 /* For internal device-mapper use. */
203 struct list_head list;
211 * Any table that contains an instance of this target must have only one.
213 #define DM_TARGET_SINGLETON 0x00000001
214 #define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
217 * Indicates that a target does not support read-only devices.
219 #define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
220 #define dm_target_always_writeable(type) \
221 ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
224 * Any device that contains a table with an instance of this target may never
225 * have tables containing any different target type.
227 #define DM_TARGET_IMMUTABLE 0x00000004
228 #define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
231 * Indicates that a target may replace any target; even immutable targets.
232 * .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined.
234 #define DM_TARGET_WILDCARD 0x00000008
235 #define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD)
238 * A target implements own bio data integrity.
240 #define DM_TARGET_INTEGRITY 0x00000010
241 #define dm_target_has_integrity(type) ((type)->features & DM_TARGET_INTEGRITY)
244 * A target passes integrity data to the lower device.
246 #define DM_TARGET_PASSES_INTEGRITY 0x00000020
247 #define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY)
250 * Indicates that a target supports host-managed zoned block devices.
252 #define DM_TARGET_ZONED_HM 0x00000040
253 #define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)
256 struct dm_table *table;
257 struct target_type *type;
263 /* If non-zero, maximum size of I/O submitted to a target. */
267 * A number of zero-length barrier bios that will be submitted
268 * to the target for the purpose of flushing cache.
270 * The bio number can be accessed with dm_bio_get_target_bio_nr.
271 * It is a responsibility of the target driver to remap these bios
272 * to the real underlying devices.
274 unsigned num_flush_bios;
277 * The number of discard bios that will be submitted to the target.
278 * The bio number can be accessed with dm_bio_get_target_bio_nr.
280 unsigned num_discard_bios;
283 * The number of secure erase bios that will be submitted to the target.
284 * The bio number can be accessed with dm_bio_get_target_bio_nr.
286 unsigned num_secure_erase_bios;
289 * The number of WRITE SAME bios that will be submitted to the target.
290 * The bio number can be accessed with dm_bio_get_target_bio_nr.
292 unsigned num_write_same_bios;
295 * The number of WRITE ZEROES bios that will be submitted to the target.
296 * The bio number can be accessed with dm_bio_get_target_bio_nr.
298 unsigned num_write_zeroes_bios;
301 * The minimum number of extra bytes allocated in each io for the
304 unsigned per_io_data_size;
306 /* target specific data */
309 /* Used to provide an error string from the ctr */
313 * Set if this target needs to receive flushes regardless of
314 * whether or not its underlying devices have support.
316 bool flush_supported:1;
319 * Set if this target needs to receive discards regardless of
320 * whether or not its underlying devices have support.
322 bool discards_supported:1;
325 /* Each target can link one of these into the table */
326 struct dm_target_callbacks {
327 struct list_head list;
328 int (*congested_fn) (struct dm_target_callbacks *, int);
331 void *dm_per_bio_data(struct bio *bio, size_t data_size);
332 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
333 unsigned dm_bio_get_target_bio_nr(const struct bio *bio);
335 u64 dm_start_time_ns_from_clone(struct bio *bio);
337 int dm_register_target(struct target_type *t);
338 void dm_unregister_target(struct target_type *t);
341 * Target argument parsing.
349 * The minimum and maximum value of a numeric argument, together with
350 * the error message to use if the number is found to be outside that range.
359 * Validate the next argument, either returning it as *value or, if invalid,
360 * returning -EINVAL and setting *error.
362 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
363 unsigned *value, char **error);
366 * Process the next argument as the start of a group containing between
367 * arg->min and arg->max further arguments. Either return the size as
368 * *num_args or, if invalid, return -EINVAL and set *error.
370 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
371 unsigned *num_args, char **error);
374 * Return the current argument and shift to the next.
376 const char *dm_shift_arg(struct dm_arg_set *as);
379 * Move through num_args arguments.
381 void dm_consume_args(struct dm_arg_set *as, unsigned num_args);
383 /*-----------------------------------------------------------------
384 * Functions for creating and manipulating mapped devices.
385 * Drop the reference with dm_put when you finish with the object.
386 *---------------------------------------------------------------*/
389 * DM_ANY_MINOR chooses the next available minor number.
391 #define DM_ANY_MINOR (-1)
392 int dm_create(int minor, struct mapped_device **md);
395 * Reference counting for md.
397 struct mapped_device *dm_get_md(dev_t dev);
398 void dm_get(struct mapped_device *md);
399 int dm_hold(struct mapped_device *md);
400 void dm_put(struct mapped_device *md);
403 * An arbitrary pointer may be stored alongside a mapped device.
405 void dm_set_mdptr(struct mapped_device *md, void *ptr);
406 void *dm_get_mdptr(struct mapped_device *md);
409 * A device can still be used while suspended, but I/O is deferred.
411 int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
412 int dm_resume(struct mapped_device *md);
417 uint32_t dm_get_event_nr(struct mapped_device *md);
418 int dm_wait_event(struct mapped_device *md, int event_nr);
419 uint32_t dm_next_uevent_seq(struct mapped_device *md);
420 void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
425 const char *dm_device_name(struct mapped_device *md);
426 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
427 struct gendisk *dm_disk(struct mapped_device *md);
428 int dm_suspended(struct dm_target *ti);
429 int dm_noflush_suspending(struct dm_target *ti);
430 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors);
431 union map_info *dm_get_rq_mapinfo(struct request *rq);
433 #ifdef CONFIG_BLK_DEV_ZONED
434 struct dm_report_zones_args {
435 struct dm_target *tgt;
436 sector_t next_sector;
439 report_zones_cb orig_cb;
440 unsigned int zone_idx;
442 /* must be filled by ->report_zones before calling dm_report_zones_cb */
445 int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data);
446 #endif /* CONFIG_BLK_DEV_ZONED */
449 * Device mapper functions to parse and create devices specified by the
450 * parameter "dm-mod.create="
452 int __init dm_early_create(struct dm_ioctl *dmi,
453 struct dm_target_spec **spec_array,
454 char **target_params_array);
456 struct queue_limits *dm_get_queue_limits(struct mapped_device *md);
459 * Geometry functions.
461 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
462 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
464 /*-----------------------------------------------------------------
465 * Functions for manipulating device-mapper tables.
466 *---------------------------------------------------------------*/
469 * First create an empty table.
471 int dm_table_create(struct dm_table **result, fmode_t mode,
472 unsigned num_targets, struct mapped_device *md);
475 * Then call this once for each target.
477 int dm_table_add_target(struct dm_table *t, const char *type,
478 sector_t start, sector_t len, char *params);
481 * Target_ctr should call this if it needs to add any callbacks.
483 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb);
486 * Target can use this to set the table's type.
487 * Can only ever be called from a target's ctr.
488 * Useful for "hybrid" target (supports both bio-based
489 * and request-based).
491 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type);
494 * Finally call this to make the table ready for use.
496 int dm_table_complete(struct dm_table *t);
499 * Destroy the table when finished.
501 void dm_table_destroy(struct dm_table *t);
504 * Target may require that it is never sent I/O larger than len.
506 int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
509 * Table reference counting.
511 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);
512 void dm_put_live_table(struct mapped_device *md, int srcu_idx);
513 void dm_sync_table(struct mapped_device *md);
518 sector_t dm_table_get_size(struct dm_table *t);
519 unsigned int dm_table_get_num_targets(struct dm_table *t);
520 fmode_t dm_table_get_mode(struct dm_table *t);
521 struct mapped_device *dm_table_get_md(struct dm_table *t);
522 const char *dm_table_device_name(struct dm_table *t);
527 void dm_table_event(struct dm_table *t);
530 * Run the queue for request-based targets.
532 void dm_table_run_md_queue_async(struct dm_table *t);
535 * The device must be suspended before calling this method.
536 * Returns the previous table, which the caller must destroy.
538 struct dm_table *dm_swap_table(struct mapped_device *md,
542 * A wrapper around vmalloc.
544 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
546 /*-----------------------------------------------------------------
548 *---------------------------------------------------------------*/
549 #define DM_NAME "device-mapper"
551 #define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"
553 #define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)
555 #define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)
556 #define DMERR_LIMIT(fmt, ...) pr_err_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
557 #define DMWARN(fmt, ...) pr_warn(DM_FMT(fmt), ##__VA_ARGS__)
558 #define DMWARN_LIMIT(fmt, ...) pr_warn_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
559 #define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)
560 #define DMINFO_LIMIT(fmt, ...) pr_info_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
562 #define DMDEBUG(fmt, ...) pr_debug(DM_FMT(fmt), ##__VA_ARGS__)
563 #define DMDEBUG_LIMIT(fmt, ...) pr_debug_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
565 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
566 0 : scnprintf(result + sz, maxlen - sz, x))
569 * Definitions of return values from target end_io function.
571 #define DM_ENDIO_DONE 0
572 #define DM_ENDIO_INCOMPLETE 1
573 #define DM_ENDIO_REQUEUE 2
574 #define DM_ENDIO_DELAY_REQUEUE 3
577 * Definitions of return values from target map function.
579 #define DM_MAPIO_SUBMITTED 0
580 #define DM_MAPIO_REMAPPED 1
581 #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
582 #define DM_MAPIO_DELAY_REQUEUE DM_ENDIO_DELAY_REQUEUE
583 #define DM_MAPIO_KILL 4
585 #define dm_sector_div64(x, y)( \
588 (x) = div64_u64_rem(x, y, &_res); \
596 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
598 #define dm_sector_div_up(n, sz) ( \
600 sector_t _r = ((n) + (sz) - 1); \
601 sector_div(_r, (sz)); \
607 * ceiling(n / size) * size
609 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
612 * Sector offset taken relative to the start of the target instead of
613 * relative to the start of the device.
615 #define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
617 static inline sector_t to_sector(unsigned long long n)
619 return (n >> SECTOR_SHIFT);
622 static inline unsigned long to_bytes(sector_t n)
624 return (n << SECTOR_SHIFT);
627 #endif /* _LINUX_DEVICE_MAPPER_H */