/*
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* Copyright (C) 2001 Sistina Software (UK) Limited.
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* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the LGPL.
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*/
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#ifndef _LINUX_DEVICE_MAPPER_H
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#define _LINUX_DEVICE_MAPPER_H
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/dm-ioctl.h>
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#include <linux/math64.h>
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#include <linux/ratelimit.h>
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#include <linux/android_kabi.h>
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struct dm_dev;
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struct dm_target;
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struct dm_table;
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struct dm_report_zones_args;
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struct mapped_device;
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struct bio_vec;
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/*
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* Type of table, mapped_device's mempool and request_queue
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*/
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enum dm_queue_mode {
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DM_TYPE_NONE = 0,
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DM_TYPE_BIO_BASED = 1,
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DM_TYPE_REQUEST_BASED = 2,
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DM_TYPE_DAX_BIO_BASED = 3,
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};
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typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
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union map_info {
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void *ptr;
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};
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/*
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* In the constructor the target parameter will already have the
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* table, type, begin and len fields filled in.
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*/
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typedef int (*dm_ctr_fn) (struct dm_target *target,
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unsigned int argc, char **argv);
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/*
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* The destructor doesn't need to free the dm_target, just
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* anything hidden ti->private.
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*/
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typedef void (*dm_dtr_fn) (struct dm_target *ti);
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/*
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* The map function must return:
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* < 0: error
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* = 0: The target will handle the io by resubmitting it later
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* = 1: simple remap complete
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* = 2: The target wants to push back the io
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*/
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typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio);
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typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti,
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struct request *rq,
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union map_info *map_context,
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struct request **clone);
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typedef void (*dm_release_clone_request_fn) (struct request *clone,
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union map_info *map_context);
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/*
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* Returns:
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* < 0 : error (currently ignored)
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* 0 : ended successfully
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* 1 : for some reason the io has still not completed (eg,
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* multipath target might want to requeue a failed io).
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* 2 : The target wants to push back the io
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*/
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typedef int (*dm_endio_fn) (struct dm_target *ti,
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struct bio *bio, blk_status_t *error);
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typedef int (*dm_request_endio_fn) (struct dm_target *ti,
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struct request *clone, blk_status_t error,
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union map_info *map_context);
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typedef void (*dm_presuspend_fn) (struct dm_target *ti);
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typedef void (*dm_presuspend_undo_fn) (struct dm_target *ti);
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typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
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typedef int (*dm_preresume_fn) (struct dm_target *ti);
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typedef void (*dm_resume_fn) (struct dm_target *ti);
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typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
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unsigned status_flags, char *result, unsigned maxlen);
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typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv,
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char *result, unsigned maxlen);
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typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti, struct block_device **bdev);
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typedef int (*dm_report_zones_fn) (struct dm_target *ti,
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struct dm_report_zones_args *args,
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unsigned int nr_zones);
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/*
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* These iteration functions are typically used to check (and combine)
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* properties of underlying devices.
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* E.g. Does at least one underlying device support flush?
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* Does any underlying device not support WRITE_SAME?
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*
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* The callout function is called once for each contiguous section of
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* an underlying device. State can be maintained in *data.
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* Return non-zero to stop iterating through any further devices.
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*/
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typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
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struct dm_dev *dev,
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sector_t start, sector_t len,
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void *data);
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/*
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* This function must iterate through each section of device used by the
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* target until it encounters a non-zero return code, which it then returns.
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* Returns zero if no callout returned non-zero.
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*/
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typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
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iterate_devices_callout_fn fn,
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void *data);
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typedef void (*dm_io_hints_fn) (struct dm_target *ti,
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struct queue_limits *limits);
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/*
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* Returns:
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* 0: The target can handle the next I/O immediately.
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* 1: The target can't handle the next I/O immediately.
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*/
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typedef int (*dm_busy_fn) (struct dm_target *ti);
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/*
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* Returns:
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* < 0 : error
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* >= 0 : the number of bytes accessible at the address
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*/
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typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff,
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long nr_pages, void **kaddr, pfn_t *pfn);
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typedef size_t (*dm_dax_copy_iter_fn)(struct dm_target *ti, pgoff_t pgoff,
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void *addr, size_t bytes, struct iov_iter *i);
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typedef int (*dm_dax_zero_page_range_fn)(struct dm_target *ti, pgoff_t pgoff,
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size_t nr_pages);
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#define PAGE_SECTORS (PAGE_SIZE / 512)
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void dm_error(const char *message);
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struct dm_dev {
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struct block_device *bdev;
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struct dax_device *dax_dev;
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fmode_t mode;
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char name[16];
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};
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dev_t dm_get_dev_t(const char *path);
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/*
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* Constructors should call these functions to ensure destination devices
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* are opened/closed correctly.
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*/
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int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
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struct dm_dev **result);
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void dm_put_device(struct dm_target *ti, struct dm_dev *d);
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/*
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* Information about a target type
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*/
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struct target_type {
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uint64_t features;
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const char *name;
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struct module *module;
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unsigned version[3];
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dm_ctr_fn ctr;
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dm_dtr_fn dtr;
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dm_map_fn map;
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dm_clone_and_map_request_fn clone_and_map_rq;
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dm_release_clone_request_fn release_clone_rq;
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dm_endio_fn end_io;
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dm_request_endio_fn rq_end_io;
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dm_presuspend_fn presuspend;
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dm_presuspend_undo_fn presuspend_undo;
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dm_postsuspend_fn postsuspend;
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dm_preresume_fn preresume;
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dm_resume_fn resume;
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dm_status_fn status;
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dm_message_fn message;
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dm_prepare_ioctl_fn prepare_ioctl;
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#ifdef CONFIG_BLK_DEV_ZONED
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dm_report_zones_fn report_zones;
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#endif
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dm_busy_fn busy;
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dm_iterate_devices_fn iterate_devices;
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dm_io_hints_fn io_hints;
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dm_dax_direct_access_fn direct_access;
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dm_dax_copy_iter_fn dax_copy_from_iter;
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dm_dax_copy_iter_fn dax_copy_to_iter;
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dm_dax_zero_page_range_fn dax_zero_page_range;
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ANDROID_KABI_RESERVE(1);
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ANDROID_KABI_RESERVE(2);
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/* For internal device-mapper use. */
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struct list_head list;
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};
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/*
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* Target features
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*/
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/*
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* Any table that contains an instance of this target must have only one.
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*/
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#define DM_TARGET_SINGLETON 0x00000001
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#define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
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/*
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* Indicates that a target does not support read-only devices.
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*/
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#define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
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#define dm_target_always_writeable(type) \
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((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
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/*
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* Any device that contains a table with an instance of this target may never
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* have tables containing any different target type.
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*/
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#define DM_TARGET_IMMUTABLE 0x00000004
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#define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
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/*
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* Indicates that a target may replace any target; even immutable targets.
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* .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined.
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*/
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#define DM_TARGET_WILDCARD 0x00000008
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#define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD)
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/*
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* A target implements own bio data integrity.
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*/
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#define DM_TARGET_INTEGRITY 0x00000010
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#define dm_target_has_integrity(type) ((type)->features & DM_TARGET_INTEGRITY)
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/*
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* A target passes integrity data to the lower device.
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*/
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#define DM_TARGET_PASSES_INTEGRITY 0x00000020
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#define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY)
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/*
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* Indicates support for zoned block devices:
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* - DM_TARGET_ZONED_HM: the target also supports host-managed zoned
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* block devices but does not support combining different zoned models.
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* - DM_TARGET_MIXED_ZONED_MODEL: the target supports combining multiple
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* devices with different zoned models.
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*/
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#define DM_TARGET_ZONED_HM 0x00000040
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#define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM)
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/*
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* A target handles REQ_NOWAIT
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*/
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#define DM_TARGET_NOWAIT 0x00000080
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#define dm_target_supports_nowait(type) ((type)->features & DM_TARGET_NOWAIT)
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/*
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* A target supports passing through inline crypto support.
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*/
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#define DM_TARGET_PASSES_CRYPTO 0x00000100
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#define dm_target_passes_crypto(type) ((type)->features & DM_TARGET_PASSES_CRYPTO)
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#ifdef CONFIG_BLK_DEV_ZONED
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#define DM_TARGET_MIXED_ZONED_MODEL 0x00000200
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#define dm_target_supports_mixed_zoned_model(type) \
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((type)->features & DM_TARGET_MIXED_ZONED_MODEL)
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#else
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#define DM_TARGET_MIXED_ZONED_MODEL 0x00000000
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#define dm_target_supports_mixed_zoned_model(type) (false)
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#endif
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struct dm_target {
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struct dm_table *table;
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struct target_type *type;
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/* target limits */
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sector_t begin;
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sector_t len;
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/* If non-zero, maximum size of I/O submitted to a target. */
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uint32_t max_io_len;
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/*
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* A number of zero-length barrier bios that will be submitted
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* to the target for the purpose of flushing cache.
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*
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* The bio number can be accessed with dm_bio_get_target_bio_nr.
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* It is a responsibility of the target driver to remap these bios
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* to the real underlying devices.
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*/
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unsigned num_flush_bios;
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/*
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* The number of discard bios that will be submitted to the target.
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* The bio number can be accessed with dm_bio_get_target_bio_nr.
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*/
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unsigned num_discard_bios;
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/*
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* The number of secure erase bios that will be submitted to the target.
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* The bio number can be accessed with dm_bio_get_target_bio_nr.
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*/
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unsigned num_secure_erase_bios;
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/*
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* The number of WRITE SAME bios that will be submitted to the target.
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* The bio number can be accessed with dm_bio_get_target_bio_nr.
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*/
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unsigned num_write_same_bios;
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/*
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* The number of WRITE ZEROES bios that will be submitted to the target.
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* The bio number can be accessed with dm_bio_get_target_bio_nr.
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*/
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unsigned num_write_zeroes_bios;
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/*
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* The minimum number of extra bytes allocated in each io for the
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* target to use.
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*/
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unsigned per_io_data_size;
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/* target specific data */
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void *private;
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/* Used to provide an error string from the ctr */
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char *error;
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/*
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* Set if this target needs to receive flushes regardless of
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* whether or not its underlying devices have support.
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*/
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bool flush_supported:1;
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/*
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* Set if this target needs to receive discards regardless of
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* whether or not its underlying devices have support.
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*/
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bool discards_supported:1;
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/*
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* Set if we need to limit the number of in-flight bios when swapping.
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*/
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bool limit_swap_bios:1;
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ANDROID_KABI_RESERVE(1);
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ANDROID_KABI_RESERVE(2);
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};
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void *dm_per_bio_data(struct bio *bio, size_t data_size);
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struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
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unsigned dm_bio_get_target_bio_nr(const struct bio *bio);
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u64 dm_start_time_ns_from_clone(struct bio *bio);
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int dm_register_target(struct target_type *t);
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void dm_unregister_target(struct target_type *t);
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/*
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* Target argument parsing.
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*/
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struct dm_arg_set {
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unsigned argc;
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char **argv;
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};
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/*
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* The minimum and maximum value of a numeric argument, together with
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* the error message to use if the number is found to be outside that range.
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*/
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struct dm_arg {
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unsigned min;
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unsigned max;
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char *error;
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};
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/*
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* Validate the next argument, either returning it as *value or, if invalid,
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* returning -EINVAL and setting *error.
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*/
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int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
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unsigned *value, char **error);
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/*
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* Process the next argument as the start of a group containing between
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* arg->min and arg->max further arguments. Either return the size as
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* *num_args or, if invalid, return -EINVAL and set *error.
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*/
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int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
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unsigned *num_args, char **error);
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/*
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* Return the current argument and shift to the next.
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*/
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const char *dm_shift_arg(struct dm_arg_set *as);
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/*
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* Move through num_args arguments.
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*/
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void dm_consume_args(struct dm_arg_set *as, unsigned num_args);
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/*-----------------------------------------------------------------
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* Functions for creating and manipulating mapped devices.
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* Drop the reference with dm_put when you finish with the object.
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*---------------------------------------------------------------*/
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/*
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* DM_ANY_MINOR chooses the next available minor number.
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*/
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#define DM_ANY_MINOR (-1)
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int dm_create(int minor, struct mapped_device **md);
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/*
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* Reference counting for md.
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*/
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struct mapped_device *dm_get_md(dev_t dev);
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void dm_get(struct mapped_device *md);
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int dm_hold(struct mapped_device *md);
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void dm_put(struct mapped_device *md);
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/*
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* An arbitrary pointer may be stored alongside a mapped device.
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*/
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void dm_set_mdptr(struct mapped_device *md, void *ptr);
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void *dm_get_mdptr(struct mapped_device *md);
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/*
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* A device can still be used while suspended, but I/O is deferred.
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*/
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int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
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int dm_resume(struct mapped_device *md);
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/*
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* Event functions.
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*/
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uint32_t dm_get_event_nr(struct mapped_device *md);
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int dm_wait_event(struct mapped_device *md, int event_nr);
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uint32_t dm_next_uevent_seq(struct mapped_device *md);
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void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
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/*
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* Info functions.
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*/
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const char *dm_device_name(struct mapped_device *md);
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int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
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struct gendisk *dm_disk(struct mapped_device *md);
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int dm_suspended(struct dm_target *ti);
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int dm_post_suspending(struct dm_target *ti);
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int dm_noflush_suspending(struct dm_target *ti);
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void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors);
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union map_info *dm_get_rq_mapinfo(struct request *rq);
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#ifdef CONFIG_BLK_DEV_ZONED
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struct dm_report_zones_args {
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struct dm_target *tgt;
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sector_t next_sector;
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void *orig_data;
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report_zones_cb orig_cb;
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unsigned int zone_idx;
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/* must be filled by ->report_zones before calling dm_report_zones_cb */
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sector_t start;
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};
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int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data);
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#endif /* CONFIG_BLK_DEV_ZONED */
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/*
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* Device mapper functions to parse and create devices specified by the
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* parameter "dm-mod.create="
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*/
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int __init dm_early_create(struct dm_ioctl *dmi,
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struct dm_target_spec **spec_array,
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char **target_params_array);
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struct queue_limits *dm_get_queue_limits(struct mapped_device *md);
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/*
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* Geometry functions.
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*/
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int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
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int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
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/*-----------------------------------------------------------------
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* Functions for manipulating device-mapper tables.
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*---------------------------------------------------------------*/
|
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/*
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* First create an empty table.
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*/
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int dm_table_create(struct dm_table **result, fmode_t mode,
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unsigned num_targets, struct mapped_device *md);
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/*
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* Then call this once for each target.
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*/
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int dm_table_add_target(struct dm_table *t, const char *type,
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sector_t start, sector_t len, char *params);
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/*
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* Target can use this to set the table's type.
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* Can only ever be called from a target's ctr.
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* Useful for "hybrid" target (supports both bio-based
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* and request-based).
|
*/
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void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type);
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/*
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* Finally call this to make the table ready for use.
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*/
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int dm_table_complete(struct dm_table *t);
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/*
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* Destroy the table when finished.
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*/
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void dm_table_destroy(struct dm_table *t);
|
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/*
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* Target may require that it is never sent I/O larger than len.
|
*/
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int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
|
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/*
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* Table reference counting.
|
*/
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struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx);
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void dm_put_live_table(struct mapped_device *md, int srcu_idx);
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void dm_sync_table(struct mapped_device *md);
|
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/*
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* Queries
|
*/
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sector_t dm_table_get_size(struct dm_table *t);
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unsigned int dm_table_get_num_targets(struct dm_table *t);
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fmode_t dm_table_get_mode(struct dm_table *t);
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struct mapped_device *dm_table_get_md(struct dm_table *t);
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const char *dm_table_device_name(struct dm_table *t);
|
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/*
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* Trigger an event.
|
*/
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void dm_table_event(struct dm_table *t);
|
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/*
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* Run the queue for request-based targets.
|
*/
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void dm_table_run_md_queue_async(struct dm_table *t);
|
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/*
|
* 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);
|
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/*
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* Table keyslot manager functions
|
*/
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void dm_destroy_keyslot_manager(struct blk_keyslot_manager *ksm);
|
|
/*
|
* A wrapper around vmalloc.
|
*/
|
void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
|
|
/*-----------------------------------------------------------------
|
* Macros.
|
*---------------------------------------------------------------*/
|
#define DM_NAME "device-mapper"
|
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#define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"
|
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#define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)
|
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#define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)
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#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))
|
|
/*
|
* 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)( \
|
{ \
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u64 _res; \
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(x) = div64_u64_rem(x, y, &_res); \
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_res; \
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} \
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)
|
|
/*
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* Ceiling(n / sz)
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*/
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#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
|
|
#define dm_sector_div_up(n, sz) ( \
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{ \
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sector_t _r = ((n) + (sz) - 1); \
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sector_div(_r, (sz)); \
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_r; \
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} \
|
)
|
|
/*
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* 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)
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{
|
return (n >> SECTOR_SHIFT);
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}
|
|
static inline unsigned long to_bytes(sector_t n)
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{
|
return (n << SECTOR_SHIFT);
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}
|
|
#endif /* _LINUX_DEVICE_MAPPER_H */
|
