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>
24 * Type of table, mapped_device's mempool and request_queue
28 DM_TYPE_BIO_BASED = 1,
29 DM_TYPE_REQUEST_BASED = 2,
30 DM_TYPE_DAX_BIO_BASED = 3,
31 DM_TYPE_NVME_BIO_BASED = 4,
34 typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
41 * In the constructor the target parameter will already have the
42 * table, type, begin and len fields filled in.
44 typedef int (*dm_ctr_fn) (struct dm_target *target,
45 unsigned int argc, char **argv);
48 * The destructor doesn't need to free the dm_target, just
49 * anything hidden ti->private.
51 typedef void (*dm_dtr_fn) (struct dm_target *ti);
54 * The map function must return:
56 * = 0: The target will handle the io by resubmitting it later
57 * = 1: simple remap complete
58 * = 2: The target wants to push back the io
60 typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio);
61 typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti,
63 union map_info *map_context,
64 struct request **clone);
65 typedef void (*dm_release_clone_request_fn) (struct request *clone,
66 union map_info *map_context);
70 * < 0 : error (currently ignored)
71 * 0 : ended successfully
72 * 1 : for some reason the io has still not completed (eg,
73 * multipath target might want to requeue a failed io).
74 * 2 : The target wants to push back the io
76 typedef int (*dm_endio_fn) (struct dm_target *ti,
77 struct bio *bio, blk_status_t *error);
78 typedef int (*dm_request_endio_fn) (struct dm_target *ti,
79 struct request *clone, blk_status_t error,
80 union map_info *map_context);
82 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
83 typedef void (*dm_presuspend_undo_fn) (struct dm_target *ti);
84 typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
85 typedef int (*dm_preresume_fn) (struct dm_target *ti);
86 typedef void (*dm_resume_fn) (struct dm_target *ti);
88 typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
89 unsigned status_flags, char *result, unsigned maxlen);
91 typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv,
92 char *result, unsigned maxlen);
94 typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti, struct block_device **bdev);
96 typedef int (*dm_report_zones_fn) (struct dm_target *ti, sector_t sector,
97 struct blk_zone *zones,
98 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 #define PAGE_SECTORS (PAGE_SIZE / 512)
146 void dm_error(const char *message);
149 struct block_device *bdev;
150 struct dax_device *dax_dev;
155 dev_t dm_get_dev_t(const char *path);
158 * Constructors should call these functions to ensure destination devices
159 * are opened/closed correctly.
161 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
162 struct dm_dev **result);
163 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
166 * Information about a target type
172 struct module *module;
177 dm_clone_and_map_request_fn clone_and_map_rq;
178 dm_release_clone_request_fn release_clone_rq;
180 dm_request_endio_fn rq_end_io;
181 dm_presuspend_fn presuspend;
182 dm_presuspend_undo_fn presuspend_undo;
183 dm_postsuspend_fn postsuspend;
184 dm_preresume_fn preresume;
187 dm_message_fn message;
188 dm_prepare_ioctl_fn prepare_ioctl;
189 #ifdef CONFIG_BLK_DEV_ZONED
190 dm_report_zones_fn report_zones;
193 dm_iterate_devices_fn iterate_devices;
194 dm_io_hints_fn io_hints;
195 dm_dax_direct_access_fn direct_access;
196 dm_dax_copy_iter_fn dax_copy_from_iter;
197 dm_dax_copy_iter_fn dax_copy_to_iter;
199 /* For internal device-mapper use. */
200 struct list_head list;
208 * Any table that contains an instance of this target must have only one.
210 #define DM_TARGET_SINGLETON 0x00000001
211 #define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
214 * Indicates that a target does not support read-only devices.
216 #define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
217 #define dm_target_always_writeable(type) \
218 ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
221 * Any device that contains a table with an instance of this target may never
222 * have tables containing any different target type.
224 #define DM_TARGET_IMMUTABLE 0x00000004
225 #define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
228 * Indicates that a target may replace any target; even immutable targets.
229 * .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined.
231 #define DM_TARGET_WILDCARD 0x00000008
232 #define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD)
235 * A target implements own bio data integrity.
237 #define DM_TARGET_INTEGRITY 0x00000010
238 #define dm_target_has_integrity(type) ((type)->features & DM_TARGET_INTEGRITY)
241 * A target passes integrity data to the lower device.
243 #define DM_TARGET_PASSES_INTEGRITY 0x00000020
244 #define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY)
247 * Indicates that a target supports host-managed zoned block devices.
249 #define DM_TARGET_ZONED_HM 0x00000040
250 #define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)
253 struct dm_table *table;
254 struct target_type *type;
260 /* If non-zero, maximum size of I/O submitted to a target. */
264 * A number of zero-length barrier bios that will be submitted
265 * to the target for the purpose of flushing cache.
267 * The bio number can be accessed with dm_bio_get_target_bio_nr.
268 * It is a responsibility of the target driver to remap these bios
269 * to the real underlying devices.
271 unsigned num_flush_bios;
274 * The number of discard bios that will be submitted to the target.
275 * The bio number can be accessed with dm_bio_get_target_bio_nr.
277 unsigned num_discard_bios;
280 * The number of secure erase bios that will be submitted to the target.
281 * The bio number can be accessed with dm_bio_get_target_bio_nr.
283 unsigned num_secure_erase_bios;
286 * The number of WRITE SAME bios that will be submitted to the target.
287 * The bio number can be accessed with dm_bio_get_target_bio_nr.
289 unsigned num_write_same_bios;
292 * The number of WRITE ZEROES bios that will be submitted to the target.
293 * The bio number can be accessed with dm_bio_get_target_bio_nr.
295 unsigned num_write_zeroes_bios;
298 * The minimum number of extra bytes allocated in each io for the
301 unsigned per_io_data_size;
303 /* target specific data */
306 /* Used to provide an error string from the ctr */
310 * Set if this target needs to receive flushes regardless of
311 * whether or not its underlying devices have support.
313 bool flush_supported:1;
316 * Set if this target needs to receive discards regardless of
317 * whether or not its underlying devices have support.
319 bool discards_supported:1;
322 /* Each target can link one of these into the table */
323 struct dm_target_callbacks {
324 struct list_head list;
325 int (*congested_fn) (struct dm_target_callbacks *, int);
328 void *dm_per_bio_data(struct bio *bio, size_t data_size);
329 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
330 unsigned dm_bio_get_target_bio_nr(const struct bio *bio);
332 int dm_register_target(struct target_type *t);
333 void dm_unregister_target(struct target_type *t);
336 * Target argument parsing.
344 * The minimum and maximum value of a numeric argument, together with
345 * the error message to use if the number is found to be outside that range.
354 * Validate the next argument, either returning it as *value or, if invalid,
355 * returning -EINVAL and setting *error.
357 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
358 unsigned *value, char **error);
361 * Process the next argument as the start of a group containing between
362 * arg->min and arg->max further arguments. Either return the size as
363 * *num_args or, if invalid, return -EINVAL and set *error.
365 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
366 unsigned *num_args, char **error);
369 * Return the current argument and shift to the next.
371 const char *dm_shift_arg(struct dm_arg_set *as);
374 * Move through num_args arguments.
376 void dm_consume_args(struct dm_arg_set *as, unsigned num_args);
378 /*-----------------------------------------------------------------
379 * Functions for creating and manipulating mapped devices.
380 * Drop the reference with dm_put when you finish with the object.
381 *---------------------------------------------------------------*/
384 * DM_ANY_MINOR chooses the next available minor number.
386 #define DM_ANY_MINOR (-1)
387 int dm_create(int minor, struct mapped_device **md);
390 * Reference counting for md.
392 struct mapped_device *dm_get_md(dev_t dev);
393 void dm_get(struct mapped_device *md);
394 int dm_hold(struct mapped_device *md);
395 void dm_put(struct mapped_device *md);
398 * An arbitrary pointer may be stored alongside a mapped device.
400 void dm_set_mdptr(struct mapped_device *md, void *ptr);
401 void *dm_get_mdptr(struct mapped_device *md);
404 * A device can still be used while suspended, but I/O is deferred.
406 int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
407 int dm_resume(struct mapped_device *md);
412 uint32_t dm_get_event_nr(struct mapped_device *md);
413 int dm_wait_event(struct mapped_device *md, int event_nr);
414 uint32_t dm_next_uevent_seq(struct mapped_device *md);
415 void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
420 const char *dm_device_name(struct mapped_device *md);
421 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
422 struct gendisk *dm_disk(struct mapped_device *md);
423 int dm_suspended(struct dm_target *ti);
424 int dm_noflush_suspending(struct dm_target *ti);
425 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors);
426 void dm_remap_zone_report(struct dm_target *ti, sector_t start,
427 struct blk_zone *zones, unsigned int *nr_zones);
428 union map_info *dm_get_rq_mapinfo(struct request *rq);
431 * Device mapper functions to parse and create devices specified by the
432 * parameter "dm-mod.create="
434 int __init dm_early_create(struct dm_ioctl *dmi,
435 struct dm_target_spec **spec_array,
436 char **target_params_array);
438 struct queue_limits *dm_get_queue_limits(struct mapped_device *md);
441 * Geometry functions.
443 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
444 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
446 /*-----------------------------------------------------------------
447 * Functions for manipulating device-mapper tables.
448 *---------------------------------------------------------------*/
451 * First create an empty table.
453 int dm_table_create(struct dm_table **result, fmode_t mode,
454 unsigned num_targets, struct mapped_device *md);
457 * Then call this once for each target.
459 int dm_table_add_target(struct dm_table *t, const char *type,
460 sector_t start, sector_t len, char *params);
463 * Target_ctr should call this if it needs to add any callbacks.
465 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb);
468 * Target can use this to set the table's type.
469 * Can only ever be called from a target's ctr.
470 * Useful for "hybrid" target (supports both bio-based
471 * and request-based).
473 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type);
476 * Finally call this to make the table ready for use.
478 int dm_table_complete(struct dm_table *t);
481 * Destroy the table when finished.
483 void dm_table_destroy(struct dm_table *t);
486 * Target may require that it is never sent I/O larger than len.
488 int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
491 * Table reference counting.
493 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);
494 void dm_put_live_table(struct mapped_device *md, int srcu_idx);
495 void dm_sync_table(struct mapped_device *md);
500 sector_t dm_table_get_size(struct dm_table *t);
501 unsigned int dm_table_get_num_targets(struct dm_table *t);
502 fmode_t dm_table_get_mode(struct dm_table *t);
503 struct mapped_device *dm_table_get_md(struct dm_table *t);
504 const char *dm_table_device_name(struct dm_table *t);
509 void dm_table_event(struct dm_table *t);
512 * Run the queue for request-based targets.
514 void dm_table_run_md_queue_async(struct dm_table *t);
517 * The device must be suspended before calling this method.
518 * Returns the previous table, which the caller must destroy.
520 struct dm_table *dm_swap_table(struct mapped_device *md,
524 * A wrapper around vmalloc.
526 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
528 /*-----------------------------------------------------------------
530 *---------------------------------------------------------------*/
531 #define DM_NAME "device-mapper"
533 #define DM_RATELIMIT(pr_func, fmt, ...) \
535 static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, \
536 DEFAULT_RATELIMIT_BURST); \
538 if (__ratelimit(&rs)) \
539 pr_func(DM_FMT(fmt), ##__VA_ARGS__); \
542 #define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"
544 #define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)
546 #define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)
547 #define DMERR_LIMIT(fmt, ...) DM_RATELIMIT(pr_err, fmt, ##__VA_ARGS__)
548 #define DMWARN(fmt, ...) pr_warn(DM_FMT(fmt), ##__VA_ARGS__)
549 #define DMWARN_LIMIT(fmt, ...) DM_RATELIMIT(pr_warn, fmt, ##__VA_ARGS__)
550 #define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)
551 #define DMINFO_LIMIT(fmt, ...) DM_RATELIMIT(pr_info, fmt, ##__VA_ARGS__)
553 #ifdef CONFIG_DM_DEBUG
554 #define DMDEBUG(fmt, ...) printk(KERN_DEBUG DM_FMT(fmt), ##__VA_ARGS__)
555 #define DMDEBUG_LIMIT(fmt, ...) DM_RATELIMIT(pr_debug, fmt, ##__VA_ARGS__)
557 #define DMDEBUG(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
558 #define DMDEBUG_LIMIT(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
561 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
562 0 : scnprintf(result + sz, maxlen - sz, x))
565 * Definitions of return values from target end_io function.
567 #define DM_ENDIO_DONE 0
568 #define DM_ENDIO_INCOMPLETE 1
569 #define DM_ENDIO_REQUEUE 2
570 #define DM_ENDIO_DELAY_REQUEUE 3
573 * Definitions of return values from target map function.
575 #define DM_MAPIO_SUBMITTED 0
576 #define DM_MAPIO_REMAPPED 1
577 #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
578 #define DM_MAPIO_DELAY_REQUEUE DM_ENDIO_DELAY_REQUEUE
579 #define DM_MAPIO_KILL 4
581 #define dm_sector_div64(x, y)( \
584 (x) = div64_u64_rem(x, y, &_res); \
592 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
594 #define dm_sector_div_up(n, sz) ( \
596 sector_t _r = ((n) + (sz) - 1); \
597 sector_div(_r, (sz)); \
603 * ceiling(n / size) * size
605 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
607 #define dm_array_too_big(fixed, obj, num) \
608 ((num) > (UINT_MAX - (fixed)) / (obj))
611 * Sector offset taken relative to the start of the target instead of
612 * relative to the start of the device.
614 #define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
616 static inline sector_t to_sector(unsigned long long n)
618 return (n >> SECTOR_SHIFT);
621 static inline unsigned long to_bytes(sector_t n)
623 return (n << SECTOR_SHIFT);
626 #endif /* _LINUX_DEVICE_MAPPER_H */