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#ifndef _LINUX_DEVICE_MAPPER_H#define _LINUX_DEVICE_MAPPER_H
#include <linux/bio.h>#include <linux/blkdev.h>#include <linux/dm-ioctl.h>#include <linux/math64.h>#include <linux/ratelimit.h>
struct dm_dev;struct dm_target;struct dm_table;struct dm_report_zones_args;struct mapped_device;struct bio_vec;enum dax_access_mode;
/* * Type of table, mapped_device's mempool and request_queue */enum dm_queue_mode { DM_TYPE_NONE = 0, DM_TYPE_BIO_BASED = 1, DM_TYPE_REQUEST_BASED = 2, DM_TYPE_DAX_BIO_BASED = 3,};
typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE, STATUSTYPE_IMA } status_type_t;
union map_info { void *ptr;};
/* * In the constructor the target parameter will already have the * table, type, begin and len fields filled in. */typedef int (*dm_ctr_fn) (struct dm_target *target, unsigned int argc, char **argv);
/* * The destructor doesn't need to free the dm_target, just * anything hidden ti->private. */typedef void (*dm_dtr_fn) (struct dm_target *ti);
/* * The map function must return: * < 0: error * = 0: The target will handle the io by resubmitting it later * = 1: simple remap complete * = 2: The target wants to push back the io */typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio);typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti, struct request *rq, union map_info *map_context, struct request **clone);typedef void (*dm_release_clone_request_fn) (struct request *clone, union map_info *map_context);
/* * Returns: * < 0 : error (currently ignored) * 0 : ended successfully * 1 : for some reason the io has still not completed (eg, * multipath target might want to requeue a failed io). * 2 : The target wants to push back the io */typedef int (*dm_endio_fn) (struct dm_target *ti, struct bio *bio, blk_status_t *error);typedef int (*dm_request_endio_fn) (struct dm_target *ti, struct request *clone, blk_status_t error, union map_info *map_context);
typedef void (*dm_presuspend_fn) (struct dm_target *ti);typedef void (*dm_presuspend_undo_fn) (struct dm_target *ti);typedef void (*dm_postsuspend_fn) (struct dm_target *ti);typedef int (*dm_preresume_fn) (struct dm_target *ti);typedef void (*dm_resume_fn) (struct dm_target *ti);
typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, unsigned int status_flags, char *result, unsigned int maxlen);
typedef int (*dm_message_fn) (struct dm_target *ti, unsigned int argc, char **argv, char *result, unsigned int maxlen);
/* * Called with *forward == true. If it remains true, the ioctl should be * forwarded to bdev. If it is reset to false, the target already fully handled * the ioctl and the return value is the return value for the whole ioctl. */typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti, struct block_device **bdev, unsigned int cmd, unsigned long arg, bool *forward);
#ifdef CONFIG_BLK_DEV_ZONEDtypedef int (*dm_report_zones_fn) (struct dm_target *ti, struct dm_report_zones_args *args, unsigned int nr_zones);#else/* * Define dm_report_zones_fn so that targets can assign to NULL if * CONFIG_BLK_DEV_ZONED disabled. Otherwise each target needs to do * awkward #ifdefs in their target_type, etc. */typedef int (*dm_report_zones_fn) (struct dm_target *dummy);#endif
/* * These iteration functions are typically used to check (and combine) * properties of underlying devices. * E.g. Does at least one underlying device support flush? * Does any underlying device not support WRITE_SAME? * * The callout function is called once for each contiguous section of * an underlying device. State can be maintained in *data. * Return non-zero to stop iterating through any further devices. */typedef int (*iterate_devices_callout_fn) (struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data);
/* * This function must iterate through each section of device used by the * target until it encounters a non-zero return code, which it then returns. * Returns zero if no callout returned non-zero. */typedef int (*dm_iterate_devices_fn) (struct dm_target *ti, iterate_devices_callout_fn fn, void *data);
typedef void (*dm_io_hints_fn) (struct dm_target *ti, struct queue_limits *limits);
/* * Returns: * 0: The target can handle the next I/O immediately. * 1: The target can't handle the next I/O immediately. */typedef int (*dm_busy_fn) (struct dm_target *ti);
/* * Returns: * < 0 : error * >= 0 : the number of bytes accessible at the address */typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff, long nr_pages, enum dax_access_mode node, void **kaddr, unsigned long *pfn);typedef int (*dm_dax_zero_page_range_fn)(struct dm_target *ti, pgoff_t pgoff, size_t nr_pages);
/* * Returns: * != 0 : number of bytes transferred * 0 : recovery write failed */typedef size_t (*dm_dax_recovery_write_fn)(struct dm_target *ti, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i);
void dm_error(const char *message);
struct dm_dev { struct block_device *bdev; struct file *bdev_file; struct dax_device *dax_dev; blk_mode_t mode; char name[16];};
/* * Constructors should call these functions to ensure destination devices * are opened/closed correctly. */int dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode, struct dm_dev **result);void dm_put_device(struct dm_target *ti, struct dm_dev *d);
/* * Helper function for getting devices */int dm_devt_from_path(const char *path, dev_t *dev_p);
/* * Information about a target type */
struct target_type { uint64_t features; const char *name; struct module *module; unsigned int version[3]; dm_ctr_fn ctr; dm_dtr_fn dtr; dm_map_fn map; dm_clone_and_map_request_fn clone_and_map_rq; dm_release_clone_request_fn release_clone_rq; dm_endio_fn end_io; dm_request_endio_fn rq_end_io; dm_presuspend_fn presuspend; dm_presuspend_undo_fn presuspend_undo; dm_postsuspend_fn postsuspend; dm_preresume_fn preresume; dm_resume_fn resume; dm_status_fn status; dm_message_fn message; dm_prepare_ioctl_fn prepare_ioctl; dm_report_zones_fn report_zones; dm_busy_fn busy; dm_iterate_devices_fn iterate_devices; dm_io_hints_fn io_hints; dm_dax_direct_access_fn direct_access; dm_dax_zero_page_range_fn dax_zero_page_range; dm_dax_recovery_write_fn dax_recovery_write;
/* For internal device-mapper use. */ struct list_head list;};
/* * Target features */
/* * Any table that contains an instance of this target must have only one. */#define DM_TARGET_SINGLETON 0x00000001#define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
/* * Indicates that a target does not support read-only devices. */#define DM_TARGET_ALWAYS_WRITEABLE 0x00000002#define dm_target_always_writeable(type) \ ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
/* * Any device that contains a table with an instance of this target may never * have tables containing any different target type. */#define DM_TARGET_IMMUTABLE 0x00000004#define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
/* * Indicates that a target may replace any target; even immutable targets. * .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined. */#define DM_TARGET_WILDCARD 0x00000008#define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD)
/* * A target implements own bio data integrity. */#define DM_TARGET_INTEGRITY 0x00000010#define dm_target_has_integrity(type) ((type)->features & DM_TARGET_INTEGRITY)
/* * A target passes integrity data to the lower device. */#define DM_TARGET_PASSES_INTEGRITY 0x00000020#define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY)
/* * Indicates support for zoned block devices: * - DM_TARGET_ZONED_HM: the target also supports host-managed zoned * block devices but does not support combining different zoned models. * - DM_TARGET_MIXED_ZONED_MODEL: the target supports combining multiple * devices with different zoned models. */#ifdef CONFIG_BLK_DEV_ZONED#define DM_TARGET_ZONED_HM 0x00000040#define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)#else#define DM_TARGET_ZONED_HM 0x00000000#define dm_target_supports_zoned_hm(type) (false)#endif
/* * A target handles REQ_NOWAIT */#define DM_TARGET_NOWAIT 0x00000080#define dm_target_supports_nowait(type) ((type)->features & DM_TARGET_NOWAIT)
/* * A target supports passing through inline crypto support. */#define DM_TARGET_PASSES_CRYPTO 0x00000100#define dm_target_passes_crypto(type) ((type)->features & DM_TARGET_PASSES_CRYPTO)
#ifdef CONFIG_BLK_DEV_ZONED#define DM_TARGET_MIXED_ZONED_MODEL 0x00000200#define dm_target_supports_mixed_zoned_model(type) \ ((type)->features & DM_TARGET_MIXED_ZONED_MODEL)#else#define DM_TARGET_MIXED_ZONED_MODEL 0x00000000#define dm_target_supports_mixed_zoned_model(type) (false)#endif
#define DM_TARGET_ATOMIC_WRITES 0x00000400#define dm_target_supports_atomic_writes(type) ((type)->features & DM_TARGET_ATOMIC_WRITES)
struct dm_target { struct dm_table *table; struct target_type *type;
/* target limits */ sector_t begin; sector_t len;
/* If non-zero, maximum size of I/O submitted to a target. */ uint32_t max_io_len;
/* * A number of zero-length barrier bios that will be submitted * to the target for the purpose of flushing cache. * * The bio number can be accessed with dm_bio_get_target_bio_nr. * It is a responsibility of the target driver to remap these bios * to the real underlying devices. */ unsigned int num_flush_bios;
/* * The number of discard bios that will be submitted to the target. * The bio number can be accessed with dm_bio_get_target_bio_nr. */ unsigned int num_discard_bios;
/* * The number of secure erase bios that will be submitted to the target. * The bio number can be accessed with dm_bio_get_target_bio_nr. */ unsigned int num_secure_erase_bios;
/* * The number of WRITE ZEROES bios that will be submitted to the target. * The bio number can be accessed with dm_bio_get_target_bio_nr. */ unsigned int num_write_zeroes_bios;
/* * The minimum number of extra bytes allocated in each io for the * target to use. */ unsigned int per_io_data_size;
/* target specific data */ void *private;
/* Used to provide an error string from the ctr */ char *error;
/* * Set if this target needs to receive flushes regardless of * whether or not its underlying devices have support. */ bool flush_supported:1;
/* * Set if this target needs to receive discards regardless of * whether or not its underlying devices have support. */ bool discards_supported:1;
/* * Automatically set by dm-core if this target supports * REQ_OP_ZONE_RESET_ALL. Otherwise, this operation will be emulated * using REQ_OP_ZONE_RESET. Target drivers must not set this manually. */ bool zone_reset_all_supported:1;
/* * Set if this target requires that discards be split on * 'max_discard_sectors' boundaries. */ bool max_discard_granularity:1;
/* * Set if we need to limit the number of in-flight bios when swapping. */ bool limit_swap_bios:1;
/* * Set if this target implements a zoned device and needs emulation of * zone append operations using regular writes. */ bool emulate_zone_append:1;
/* * Set if the target will submit IO using dm_submit_bio_remap() * after returning DM_MAPIO_SUBMITTED from its map function. */ bool accounts_remapped_io:1;
/* * Set if the target will submit the DM bio without first calling * bio_set_dev(). NOTE: ideally a target should _not_ need this. */ bool needs_bio_set_dev:1;
/* * Set if the target supports flush optimization. If all the targets in * a table have flush_bypasses_map set, the dm core will not send * flushes to the targets via a ->map method. It will iterate over * dm_table->devices and send flushes to the devices directly. This * optimization reduces the number of flushes being sent when multiple * targets in a table use the same underlying device. * * This optimization may be enabled on targets that just pass the * flushes to the underlying devices without performing any other * actions on the flush request. Currently, dm-linear and dm-stripe * support it. */ bool flush_bypasses_map:1;
/* * Set if the target calls bio_integrity_alloc on bios received * in the map method. */ bool mempool_needs_integrity:1;};
void *dm_per_bio_data(struct bio *bio, size_t data_size);struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);unsigned int dm_bio_get_target_bio_nr(const struct bio *bio);
u64 dm_start_time_ns_from_clone(struct bio *bio);
int dm_register_target(struct target_type *t);void dm_unregister_target(struct target_type *t);
/* * Target argument parsing. */struct dm_arg_set { unsigned int argc; char **argv;};
/* * The minimum and maximum value of a numeric argument, together with * the error message to use if the number is found to be outside that range. */struct dm_arg { unsigned int min; unsigned int max; char *error;};
/* * Validate the next argument, either returning it as *value or, if invalid, * returning -EINVAL and setting *error. */int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set, unsigned int *value, char **error);
/* * Process the next argument as the start of a group containing between * arg->min and arg->max further arguments. Either return the size as * *num_args or, if invalid, return -EINVAL and set *error. */int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set, unsigned int *num_args, char **error);
/* * Return the current argument and shift to the next. */const char *dm_shift_arg(struct dm_arg_set *as);
/* * Move through num_args arguments. */void dm_consume_args(struct dm_arg_set *as, unsigned int num_args);
/* *---------------------------------------------------------------- * Functions for creating and manipulating mapped devices. * Drop the reference with dm_put when you finish with the object. *---------------------------------------------------------------- */
/* * DM_ANY_MINOR chooses the next available minor number. */#define DM_ANY_MINOR (-1)int dm_create(int minor, struct mapped_device **md);
/* * Reference counting for md. */struct mapped_device *dm_get_md(dev_t dev);void dm_get(struct mapped_device *md);int dm_hold(struct mapped_device *md);void dm_put(struct mapped_device *md);
/* * An arbitrary pointer may be stored alongside a mapped device. */void dm_set_mdptr(struct mapped_device *md, void *ptr);void *dm_get_mdptr(struct mapped_device *md);
/* * A device can still be used while suspended, but I/O is deferred. */int dm_suspend(struct mapped_device *md, unsigned int suspend_flags);int dm_resume(struct mapped_device *md);
/* * Event functions. */uint32_t dm_get_event_nr(struct mapped_device *md);int dm_wait_event(struct mapped_device *md, int event_nr);uint32_t dm_next_uevent_seq(struct mapped_device *md);void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
/* * Info functions. */const char *dm_device_name(struct mapped_device *md);int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);struct gendisk *dm_disk(struct mapped_device *md);int dm_suspended(struct dm_target *ti);int dm_post_suspending(struct dm_target *ti);int dm_noflush_suspending(struct dm_target *ti);void dm_accept_partial_bio(struct bio *bio, unsigned int n_sectors);void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone);
#ifdef CONFIG_BLK_DEV_ZONEDstruct dm_report_zones_args { struct dm_target *tgt; struct gendisk *disk; sector_t next_sector;
unsigned int zone_idx;
/* for block layer ->report_zones */ struct blk_report_zones_args *rep_args;
/* for internal users */ report_zones_cb cb; void *data;
/* must be filled by ->report_zones before calling dm_report_zones_cb */ sector_t start;};int dm_report_zones(struct block_device *bdev, sector_t start, sector_t sector, struct dm_report_zones_args *args, unsigned int nr_zones);#endif /* CONFIG_BLK_DEV_ZONED */
/* * Device mapper functions to parse and create devices specified by the * parameter "dm-mod.create=" */int __init dm_early_create(struct dm_ioctl *dmi, struct dm_target_spec **spec_array, char **target_params_array);
/* * Geometry functions. */int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
/* *--------------------------------------------------------------- * Functions for manipulating device-mapper tables. *--------------------------------------------------------------- */
/* * First create an empty table. */int dm_table_create(struct dm_table **result, blk_mode_t mode, unsigned int num_targets, struct mapped_device *md);
/* * Then call this once for each target. */int dm_table_add_target(struct dm_table *t, const char *type, sector_t start, sector_t len, char *params);
/* * Target can use this to set the table's type. * Can only ever be called from a target's ctr. * Useful for "hybrid" target (supports both bio-based * and request-based). */void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type);
/* * Finally call this to make the table ready for use. */int dm_table_complete(struct dm_table *t);
/* * Destroy the table when finished. */void dm_table_destroy(struct dm_table *t);
/* * Target may require that it is never sent I/O larger than len. */int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
/* * Table reference counting. */struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);void dm_put_live_table(struct mapped_device *md, int srcu_idx);void dm_sync_table(struct mapped_device *md);
/* * Queries */sector_t dm_table_get_size(struct dm_table *t);blk_mode_t dm_table_get_mode(struct dm_table *t);struct mapped_device *dm_table_get_md(struct dm_table *t);const char *dm_table_device_name(struct dm_table *t);
/* * Trigger an event. */void dm_table_event(struct dm_table *t);
/* * Run the queue for request-based targets. */void dm_table_run_md_queue_async(struct dm_table *t);
/* * The device must be suspended before calling this method. * Returns the previous table, which the caller must destroy. */struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *t);
/* * Table blk_crypto_profile functions */void dm_destroy_crypto_profile(struct blk_crypto_profile *profile);
/* *--------------------------------------------------------------- * Macros. *--------------------------------------------------------------- */#define DM_NAME "device-mapper"
#define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"
#define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)
#define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)#define DMERR_LIMIT(fmt, ...) pr_err_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)#define DMWARN(fmt, ...) pr_warn(DM_FMT(fmt), ##__VA_ARGS__)#define DMWARN_LIMIT(fmt, ...) pr_warn_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)#define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)#define DMINFO_LIMIT(fmt, ...) pr_info_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
#define DMDEBUG(fmt, ...) pr_debug(DM_FMT(fmt), ##__VA_ARGS__)#define DMDEBUG_LIMIT(fmt, ...) pr_debug_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
#define DMEMIT(x...) (sz += ((sz >= maxlen) ? 0 : scnprintf(result + sz, maxlen - sz, x)))
#define DMEMIT_TARGET_NAME_VERSION(y) \ DMEMIT("target_name=%s,target_version=%u.%u.%u", \ (y)->name, (y)->version[0], (y)->version[1], (y)->version[2])
/** * module_dm() - Helper macro for DM targets that don't do anything * special in their module_init and module_exit. * Each module may only use this macro once, and calling it replaces * module_init() and module_exit(). * * @name: DM target's name */#define module_dm(name) \static int __init dm_##name##_init(void) \{ \ return dm_register_target(&(name##_target)); \} \module_init(dm_##name##_init) \static void __exit dm_##name##_exit(void) \{ \ dm_unregister_target(&(name##_target)); \} \module_exit(dm_##name##_exit)
/* * Definitions of return values from target end_io function. */#define DM_ENDIO_DONE 0#define DM_ENDIO_INCOMPLETE 1#define DM_ENDIO_REQUEUE 2#define DM_ENDIO_DELAY_REQUEUE 3
/* * Definitions of return values from target map function. */#define DM_MAPIO_SUBMITTED 0#define DM_MAPIO_REMAPPED 1#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE#define DM_MAPIO_DELAY_REQUEUE DM_ENDIO_DELAY_REQUEUE#define DM_MAPIO_KILL 4
#define dm_sector_div64(x, y)( \{ \ u64 _res; \ (x) = div64_u64_rem(x, y, &_res); \ _res; \} \)
/* * Ceiling(n / sz) */#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
#define dm_sector_div_up(n, sz) ( \{ \ sector_t _r = ((n) + (sz) - 1); \ sector_div(_r, (sz)); \ _r; \} \)
/* * ceiling(n / size) * size */#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
/* * Sector offset taken relative to the start of the target instead of * relative to the start of the device. */#define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
static inline sector_t to_sector(unsigned long long n){ return (n >> SECTOR_SHIFT);}
static inline unsigned long to_bytes(sector_t n){ return (n << SECTOR_SHIFT);}
static inline void dm_stack_bs_limits(struct queue_limits *limits, unsigned int bs){ limits->logical_block_size = max(limits->logical_block_size, bs); limits->physical_block_size = max(limits->physical_block_size, bs); limits->io_min = max(limits->io_min, bs);}
#endif /* _LINUX_DEVICE_MAPPER_H */