LXR linux/drivers/md/dm.h

   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;
  48
  49/*-----------------------------------------------------------------
  50 * Internal table functions.
  51 *---------------------------------------------------------------*/
  52void dm_table_event_callback(struct dm_table *t,
  53                             void (*fn)(void *), void *context);
  54struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  55struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  56bool dm_table_has_no_data_devices(struct dm_table *table);
  57int dm_calculate_queue_limits(struct dm_table *table,
  58                              struct queue_limits *limits);
  59void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  60                               struct queue_limits *limits);
  61struct list_head *dm_table_get_devices(struct dm_table *t);
  62void dm_table_presuspend_targets(struct dm_table *t);
  63void dm_table_presuspend_undo_targets(struct dm_table *t);
  64void dm_table_postsuspend_targets(struct dm_table *t);
  65int dm_table_resume_targets(struct dm_table *t);
  66int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  67enum dm_queue_mode dm_table_get_type(struct dm_table *t);
  68struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  69struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
  70struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
  71bool dm_table_bio_based(struct dm_table *t);
  72bool dm_table_request_based(struct dm_table *t);
  73void dm_table_free_md_mempools(struct dm_table *t);
  74struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  75bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,
  76                           int *blocksize);
  77int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
  78                           sector_t start, sector_t len, void *data);
  79
  80void dm_lock_md_type(struct mapped_device *md);
  81void dm_unlock_md_type(struct mapped_device *md);
  82void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
  83enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
  84struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  85
  86int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
  87
  88/*
  89 * To check whether the target type is bio-based or not (request-based).
  90 */
  91#define dm_target_bio_based(t) ((t)->type->map != NULL)
  92
  93/*
  94 * To check whether the target type is request-based or not (bio-based).
  95 */
  96#define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
  97
  98/*
  99 * To check whether the target type is a hybrid (capable of being
 100 * either request-based or bio-based).
 101 */
 102#define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
 103
 104/*-----------------------------------------------------------------
 105 * A registry of target types.
 106 *---------------------------------------------------------------*/
 107int dm_target_init(void);
 108void dm_target_exit(void);
 109struct target_type *dm_get_target_type(const char *name);
 110void dm_put_target_type(struct target_type *tt);
 111int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 112                                        void *param), void *param);
 113
 114int dm_split_args(int *argc, char ***argvp, char *input);
 115
 116/*
 117 * Is this mapped_device being deleted?
 118 */
 119int dm_deleting_md(struct mapped_device *md);
 120
 121/*
 122 * Is this mapped_device suspended?
 123 */
 124int dm_suspended_md(struct mapped_device *md);
 125
 126/*
 127 * Internal suspend and resume methods.
 128 */
 129int dm_suspended_internally_md(struct mapped_device *md);
 130void dm_internal_suspend_fast(struct mapped_device *md);
 131void dm_internal_resume_fast(struct mapped_device *md);
 132void dm_internal_suspend_noflush(struct mapped_device *md);
 133void dm_internal_resume(struct mapped_device *md);
 134
 135/*
 136 * Test if the device is scheduled for deferred remove.
 137 */
 138int dm_test_deferred_remove_flag(struct mapped_device *md);
 139
 140/*
 141 * Try to remove devices marked for deferred removal.
 142 */
 143void dm_deferred_remove(void);
 144
 145/*
 146 * The device-mapper can be driven through one of two interfaces;
 147 * ioctl or filesystem, depending which patch you have applied.
 148 */
 149int dm_interface_init(void);
 150void dm_interface_exit(void);
 151
 152/*
 153 * sysfs interface
 154 */
 155int dm_sysfs_init(struct mapped_device *md);
 156void dm_sysfs_exit(struct mapped_device *md);
 157struct kobject *dm_kobject(struct mapped_device *md);
 158struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 159
 160/*
 161 * The kobject helper
 162 */
 163void dm_kobject_release(struct kobject *kobj);
 164
 165/*
 166 * Targets for linear and striped mappings
 167 */
 168int dm_linear_init(void);
 169void dm_linear_exit(void);
 170
 171int dm_stripe_init(void);
 172void dm_stripe_exit(void);
 173
 174/*
 175 * mapped_device operations
 176 */
 177void dm_destroy(struct mapped_device *md);
 178void dm_destroy_immediate(struct mapped_device *md);
 179int dm_open_count(struct mapped_device *md);
 180int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
 181int dm_cancel_deferred_remove(struct mapped_device *md);
 182int dm_request_based(struct mapped_device *md);
 183sector_t dm_get_size(struct mapped_device *md);
 184struct request_queue *dm_get_md_queue(struct mapped_device *md);
 185int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
 186                        struct dm_dev **result);
 187void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
 188struct dm_stats *dm_get_stats(struct mapped_device *md);
 189
 190int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 191                      unsigned cookie);
 192
 193void dm_internal_suspend(struct mapped_device *md);
 194void dm_internal_resume(struct mapped_device *md);
 195
 196int dm_io_init(void);
 197void dm_io_exit(void);
 198
 199int dm_kcopyd_init(void);
 200void dm_kcopyd_exit(void);
 201
 202/*
 203 * Mempool operations
 204 */
 205struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
 206                                            unsigned integrity, unsigned per_bio_data_size,
 207                                            unsigned min_pool_size);
 208void dm_free_md_mempools(struct dm_md_mempools *pools);
 209
 210/*
 211 * Various helpers
 212 */
 213unsigned dm_get_reserved_bio_based_ios(void);
 214
 215#endif
 216