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  */
  40 struct dm_dev_internal {
  41         struct list_head list;
  42         refcount_t count;
  43         struct dm_dev *dm_dev;
  44 };
  45
  46 struct dm_table;
  47 struct dm_md_mempools;
  48
  49 /*-----------------------------------------------------------------
  50  * Internal table functions.
  51  *---------------------------------------------------------------*/
  52 void dm_table_destroy(struct dm_table *t);
  53 void dm_table_event_callback(struct dm_table *t,
  54                              void (*fn)(void *), void *context);
  55 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  56 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  57 bool dm_table_has_no_data_devices(struct dm_table *table);
  58 int dm_calculate_queue_limits(struct dm_table *table,
  59                               struct queue_limits *limits);
  60 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  61                                struct queue_limits *limits);
  62 struct list_head *dm_table_get_devices(struct dm_table *t);
  63 void dm_table_presuspend_targets(struct dm_table *t);
  64 void dm_table_presuspend_undo_targets(struct dm_table *t);
  65 void dm_table_postsuspend_targets(struct dm_table *t);
  66 int dm_table_resume_targets(struct dm_table *t);
  67 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  68 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
  69 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  70 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
  71 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
  72 bool dm_table_bio_based(struct dm_table *t);
  73 bool dm_table_request_based(struct dm_table *t);
  74 bool dm_table_all_blk_mq_devices(struct dm_table *t);
  75 void dm_table_free_md_mempools(struct dm_table *t);
  76 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  77
  78 void dm_lock_md_type(struct mapped_device *md);
  79 void dm_unlock_md_type(struct mapped_device *md);
  80 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
  81 enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
  82 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  83
  84 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
  85
  86 /*
  87  * To check the return value from dm_table_find_target().
  88  */
  89 #define dm_target_is_valid(t) ((t)->table)
  90
  91 /*
  92  * To check whether the target type is bio-based or not (request-based).
  93  */
  94 #define dm_target_bio_based(t) ((t)->type->map != NULL)
  95
  96 /*
  97  * To check whether the target type is request-based or not (bio-based).
  98  */
  99 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
 100
 101 /*
 102  * To check whether the target type is a hybrid (capable of being
 103  * either request-based or bio-based).
 104  */
 105 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
 106
 107 /*-----------------------------------------------------------------
 108  * A registry of target types.
 109  *---------------------------------------------------------------*/
 110 int dm_target_init(void);
 111 void dm_target_exit(void);
 112 struct target_type *dm_get_target_type(const char *name);
 113 void dm_put_target_type(struct target_type *tt);
 114 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 115                                         void *param), void *param);
 116
 117 int dm_split_args(int *argc, char ***argvp, char *input);
 118
 119 /*
 120  * Is this mapped_device being deleted?
 121  */
 122 int dm_deleting_md(struct mapped_device *md);
 123
 124 /*
 125  * Is this mapped_device suspended?
 126  */
 127 int dm_suspended_md(struct mapped_device *md);
 128
 129 /*
 130  * Internal suspend and resume methods.
 131  */
 132 int dm_suspended_internally_md(struct mapped_device *md);
 133 void dm_internal_suspend_fast(struct mapped_device *md);
 134 void dm_internal_resume_fast(struct mapped_device *md);
 135 void dm_internal_suspend_noflush(struct mapped_device *md);
 136 void dm_internal_resume(struct mapped_device *md);
 137
 138 /*
 139  * Test if the device is scheduled for deferred remove.
 140  */
 141 int dm_test_deferred_remove_flag(struct mapped_device *md);
 142
 143 /*
 144  * Try to remove devices marked for deferred removal.
 145  */
 146 void dm_deferred_remove(void);
 147
 148 /*
 149  * The device-mapper can be driven through one of two interfaces;
 150  * ioctl or filesystem, depending which patch you have applied.
 151  */
 152 int dm_interface_init(void);
 153 void dm_interface_exit(void);
 154
 155 /*
 156  * sysfs interface
 157  */
 158 int dm_sysfs_init(struct mapped_device *md);
 159 void dm_sysfs_exit(struct mapped_device *md);
 160 struct kobject *dm_kobject(struct mapped_device *md);
 161 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 162
 163 /*
 164  * The kobject helper
 165  */
 166 void dm_kobject_release(struct kobject *kobj);
 167
 168 /*
 169  * Targets for linear and striped mappings
 170  */
 171 int dm_linear_init(void);
 172 void dm_linear_exit(void);
 173
 174 int dm_stripe_init(void);
 175 void dm_stripe_exit(void);
 176
 177 /*
 178  * mapped_device operations
 179  */
 180 void dm_destroy(struct mapped_device *md);
 181 void dm_destroy_immediate(struct mapped_device *md);
 182 int dm_open_count(struct mapped_device *md);
 183 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
 184 int dm_cancel_deferred_remove(struct mapped_device *md);
 185 int dm_request_based(struct mapped_device *md);
 186 sector_t dm_get_size(struct mapped_device *md);
 187 struct request_queue *dm_get_md_queue(struct mapped_device *md);
 188 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
 189                         struct dm_dev **result);
 190 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
 191 struct dm_stats *dm_get_stats(struct mapped_device *md);
 192
 193 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 194                       unsigned cookie);
 195
 196 void dm_internal_suspend(struct mapped_device *md);
 197 void dm_internal_resume(struct mapped_device *md);
 198
 199 int dm_io_init(void);
 200 void dm_io_exit(void);
 201
 202 int dm_kcopyd_init(void);
 203 void dm_kcopyd_exit(void);
 204
 205 /*
 206  * Mempool operations
 207  */
 208 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
 209                                             unsigned integrity, unsigned per_bio_data_size);
 210 void dm_free_md_mempools(struct dm_md_mempools *pools);
 211
 212 /*
 213  * Various helpers
 214  */
 215 unsigned dm_get_reserved_bio_based_ios(void);
 216
 217 #endif