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_event_callback(struct dm_table *t,
  53                              void (*fn)(void *), void *context);
  54 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  55 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  56 bool dm_table_has_no_data_devices(struct dm_table *table);
  57 int dm_calculate_queue_limits(struct dm_table *table,
  58                               struct queue_limits *limits);
  59 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  60                                struct queue_limits *limits);
  61 struct list_head *dm_table_get_devices(struct dm_table *t);
  62 void dm_table_presuspend_targets(struct dm_table *t);
  63 void dm_table_presuspend_undo_targets(struct dm_table *t);
  64 void dm_table_postsuspend_targets(struct dm_table *t);
  65 int dm_table_resume_targets(struct dm_table *t);
  66 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  67 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
  68 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  69 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
  70 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
  71 bool dm_table_bio_based(struct dm_table *t);
  72 bool dm_table_request_based(struct dm_table *t);
  73 void dm_table_free_md_mempools(struct dm_table *t);
  74 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  75 bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,
  76                            int *blocksize);
  77 int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
  78                            sector_t start, sector_t len, void *data);
  79
  80 void dm_lock_md_type(struct mapped_device *md);
  81 void dm_unlock_md_type(struct mapped_device *md);
  82 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
  83 enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
  84 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  85
  86 int 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  *---------------------------------------------------------------*/
 107 int dm_target_init(void);
 108 void dm_target_exit(void);
 109 struct target_type *dm_get_target_type(const char *name);
 110 void dm_put_target_type(struct target_type *tt);
 111 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 112                                         void *param), void *param);
 113
 114 int dm_split_args(int *argc, char ***argvp, char *input);
 115
 116 /*
 117  * Is this mapped_device being deleted?
 118  */
 119 int dm_deleting_md(struct mapped_device *md);
 120
 121 /*
 122  * Is this mapped_device suspended?
 123  */
 124 int dm_suspended_md(struct mapped_device *md);
 125
 126 /*
 127  * Internal suspend and resume methods.
 128  */
 129 int dm_suspended_internally_md(struct mapped_device *md);
 130 void dm_internal_suspend_fast(struct mapped_device *md);
 131 void dm_internal_resume_fast(struct mapped_device *md);
 132 void dm_internal_suspend_noflush(struct mapped_device *md);
 133 void dm_internal_resume(struct mapped_device *md);
 134
 135 /*
 136  * Test if the device is scheduled for deferred remove.
 137  */
 138 int dm_test_deferred_remove_flag(struct mapped_device *md);
 139
 140 /*
 141  * Try to remove devices marked for deferred removal.
 142  */
 143 void 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  */
 149 int dm_interface_init(void);
 150 void dm_interface_exit(void);
 151
 152 /*
 153  * sysfs interface
 154  */
 155 int dm_sysfs_init(struct mapped_device *md);
 156 void dm_sysfs_exit(struct mapped_device *md);
 157 struct kobject *dm_kobject(struct mapped_device *md);
 158 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 159
 160 /*
 161  * The kobject helper
 162  */
 163 void dm_kobject_release(struct kobject *kobj);
 164
 165 /*
 166  * Targets for linear and striped mappings
 167  */
 168 int dm_linear_init(void);
 169 void dm_linear_exit(void);
 170
 171 int dm_stripe_init(void);
 172 void dm_stripe_exit(void);
 173
 174 /*
 175  * mapped_device operations
 176  */
 177 void dm_destroy(struct mapped_device *md);
 178 void dm_destroy_immediate(struct mapped_device *md);
 179 int dm_open_count(struct mapped_device *md);
 180 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
 181 int dm_cancel_deferred_remove(struct mapped_device *md);
 182 int dm_request_based(struct mapped_device *md);
 183 sector_t dm_get_size(struct mapped_device *md);
 184 struct request_queue *dm_get_md_queue(struct mapped_device *md);
 185 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
 186                         struct dm_dev **result);
 187 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
 188 struct dm_stats *dm_get_stats(struct mapped_device *md);
 189
 190 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 191                       unsigned cookie);
 192
 193 void dm_internal_suspend(struct mapped_device *md);
 194 void dm_internal_resume(struct mapped_device *md);
 195
 196 int dm_io_init(void);
 197 void dm_io_exit(void);
 198
 199 int dm_kcopyd_init(void);
 200 void dm_kcopyd_exit(void);
 201
 202 /*
 203  * Mempool operations
 204  */
 205 struct 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);
 208 void dm_free_md_mempools(struct dm_md_mempools *pools);
 209
 210 /*
 211  * Various helpers
 212  */
 213 unsigned dm_get_reserved_bio_based_ios(void);
 214
 215 #endif