linux/drivers/md/dm.h
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   1/*
   2 * Internal header file for device mapper
   3 *
   4 * Copyright (C) 2001, 2002 Sistina Software
   5 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
   6 *
   7 * This file is released under the LGPL.
   8 */
   9
  10#ifndef DM_INTERNAL_H
  11#define DM_INTERNAL_H
  12
  13#include <linux/fs.h>
  14#include <linux/device-mapper.h>
  15#include <linux/list.h>
  16#include <linux/moduleparam.h>
  17#include <linux/blkdev.h>
  18#include <linux/backing-dev.h>
  19#include <linux/hdreg.h>
  20#include <linux/completion.h>
  21#include <linux/kobject.h>
  22#include <linux/refcount.h>
  23
  24#include "dm-stats.h"
  25
  26/*
  27 * Suspend feature flags
  28 */
  29#define DM_SUSPEND_LOCKFS_FLAG          (1 << 0)
  30#define DM_SUSPEND_NOFLUSH_FLAG         (1 << 1)
  31
  32/*
  33 * Status feature flags
  34 */
  35#define DM_STATUS_NOFLUSH_FLAG          (1 << 0)
  36
  37/*
  38 * List of devices that a metadevice uses and should open/close.
  39 */
  40struct dm_dev_internal {
  41        struct list_head list;
  42        refcount_t count;
  43        struct dm_dev *dm_dev;
  44};
  45
  46struct dm_table;
  47struct dm_md_mempools;
  48struct dm_target_io;
  49struct dm_io;
  50
  51/*-----------------------------------------------------------------
  52 * Internal table functions.
  53 *---------------------------------------------------------------*/
  54void dm_table_event_callback(struct dm_table *t,
  55                             void (*fn)(void *), void *context);
  56struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  57struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  58bool dm_table_has_no_data_devices(struct dm_table *table);
  59int dm_calculate_queue_limits(struct dm_table *table,
  60                              struct queue_limits *limits);
  61int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  62                              struct queue_limits *limits);
  63struct list_head *dm_table_get_devices(struct dm_table *t);
  64void dm_table_presuspend_targets(struct dm_table *t);
  65void dm_table_presuspend_undo_targets(struct dm_table *t);
  66void dm_table_postsuspend_targets(struct dm_table *t);
  67int dm_table_resume_targets(struct dm_table *t);
  68enum dm_queue_mode dm_table_get_type(struct dm_table *t);
  69struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  70struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
  71struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
  72bool dm_table_bio_based(struct dm_table *t);
  73bool dm_table_request_based(struct dm_table *t);
  74void dm_table_free_md_mempools(struct dm_table *t);
  75struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  76
  77void dm_lock_md_type(struct mapped_device *md);
  78void dm_unlock_md_type(struct mapped_device *md);
  79void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
  80enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
  81struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  82
  83int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
  84
  85/*
  86 * To check whether the target type is bio-based or not (request-based).
  87 */
  88#define dm_target_bio_based(t) ((t)->type->map != NULL)
  89
  90/*
  91 * To check whether the target type is request-based or not (bio-based).
  92 */
  93#define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
  94
  95/*
  96 * To check whether the target type is a hybrid (capable of being
  97 * either request-based or bio-based).
  98 */
  99#define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
 100
 101/*
 102 * Zoned targets related functions.
 103 */
 104int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q);
 105void dm_zone_endio(struct dm_io *io, struct bio *clone);
 106#ifdef CONFIG_BLK_DEV_ZONED
 107void dm_cleanup_zoned_dev(struct mapped_device *md);
 108int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
 109                        unsigned int nr_zones, report_zones_cb cb, void *data);
 110bool dm_is_zone_write(struct mapped_device *md, struct bio *bio);
 111int dm_zone_map_bio(struct dm_target_io *io);
 112#else
 113static inline void dm_cleanup_zoned_dev(struct mapped_device *md) {}
 114#define dm_blk_report_zones     NULL
 115static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
 116{
 117        return false;
 118}
 119static inline int dm_zone_map_bio(struct dm_target_io *tio)
 120{
 121        return DM_MAPIO_KILL;
 122}
 123#endif
 124
 125/*-----------------------------------------------------------------
 126 * A registry of target types.
 127 *---------------------------------------------------------------*/
 128int dm_target_init(void);
 129void dm_target_exit(void);
 130struct target_type *dm_get_target_type(const char *name);
 131void dm_put_target_type(struct target_type *tt);
 132int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 133                                        void *param), void *param);
 134
 135int dm_split_args(int *argc, char ***argvp, char *input);
 136
 137/*
 138 * Is this mapped_device being deleted?
 139 */
 140int dm_deleting_md(struct mapped_device *md);
 141
 142/*
 143 * Is this mapped_device suspended?
 144 */
 145int dm_suspended_md(struct mapped_device *md);
 146
 147/*
 148 * Internal suspend and resume methods.
 149 */
 150int dm_suspended_internally_md(struct mapped_device *md);
 151void dm_internal_suspend_fast(struct mapped_device *md);
 152void dm_internal_resume_fast(struct mapped_device *md);
 153void dm_internal_suspend_noflush(struct mapped_device *md);
 154void dm_internal_resume(struct mapped_device *md);
 155
 156/*
 157 * Test if the device is scheduled for deferred remove.
 158 */
 159int dm_test_deferred_remove_flag(struct mapped_device *md);
 160
 161/*
 162 * Try to remove devices marked for deferred removal.
 163 */
 164void dm_deferred_remove(void);
 165
 166/*
 167 * The device-mapper can be driven through one of two interfaces;
 168 * ioctl or filesystem, depending which patch you have applied.
 169 */
 170int dm_interface_init(void);
 171void dm_interface_exit(void);
 172
 173/*
 174 * sysfs interface
 175 */
 176int dm_sysfs_init(struct mapped_device *md);
 177void dm_sysfs_exit(struct mapped_device *md);
 178struct kobject *dm_kobject(struct mapped_device *md);
 179struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 180
 181/*
 182 * The kobject helper
 183 */
 184void dm_kobject_release(struct kobject *kobj);
 185
 186/*
 187 * Targets for linear and striped mappings
 188 */
 189int dm_linear_init(void);
 190void dm_linear_exit(void);
 191
 192int dm_stripe_init(void);
 193void dm_stripe_exit(void);
 194
 195/*
 196 * mapped_device operations
 197 */
 198void dm_destroy(struct mapped_device *md);
 199void dm_destroy_immediate(struct mapped_device *md);
 200int dm_open_count(struct mapped_device *md);
 201int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
 202int dm_cancel_deferred_remove(struct mapped_device *md);
 203int dm_request_based(struct mapped_device *md);
 204int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
 205                        struct dm_dev **result);
 206void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
 207
 208int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 209                      unsigned cookie);
 210
 211void dm_internal_suspend(struct mapped_device *md);
 212void dm_internal_resume(struct mapped_device *md);
 213
 214int dm_io_init(void);
 215void dm_io_exit(void);
 216
 217int dm_kcopyd_init(void);
 218void dm_kcopyd_exit(void);
 219
 220/*
 221 * Mempool operations
 222 */
 223struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
 224                                            unsigned integrity, unsigned per_bio_data_size,
 225                                            unsigned min_pool_size);
 226void dm_free_md_mempools(struct dm_md_mempools *pools);
 227
 228/*
 229 * Various helpers
 230 */
 231unsigned dm_get_reserved_bio_based_ios(void);
 232
 233#endif
 234