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 #include <linux/log2.h>
  24
  25 #include "dm-stats.h"
  26
  27 /*
  28  * Suspend feature flags
  29  */
  30 #define DM_SUSPEND_LOCKFS_FLAG          (1 << 0)
  31 #define DM_SUSPEND_NOFLUSH_FLAG         (1 << 1)
  32
  33 /*
  34  * Status feature flags
  35  */
  36 #define DM_STATUS_NOFLUSH_FLAG          (1 << 0)
  37
  38 /*
  39  * List of devices that a metadevice uses and should open/close.
  40  */
  41 struct dm_dev_internal {
  42         struct list_head list;
  43         refcount_t count;
  44         struct dm_dev *dm_dev;
  45 };
  46
  47 struct dm_table;
  48 struct dm_md_mempools;
  49 struct dm_target_io;
  50 struct dm_io;
  51
  52 /*
  53  *---------------------------------------------------------------
  54  * Internal table functions.
  55  *---------------------------------------------------------------
  56  */
  57 void dm_table_event_callback(struct dm_table *t,
  58                              void (*fn)(void *), void *context);
  59 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  60 bool dm_table_has_no_data_devices(struct dm_table *table);
  61 int dm_calculate_queue_limits(struct dm_table *table,
  62                               struct queue_limits *limits);
  63 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  64                               struct queue_limits *limits);
  65 struct list_head *dm_table_get_devices(struct dm_table *t);
  66 void dm_table_presuspend_targets(struct dm_table *t);
  67 void dm_table_presuspend_undo_targets(struct dm_table *t);
  68 void dm_table_postsuspend_targets(struct dm_table *t);
  69 int dm_table_resume_targets(struct dm_table *t);
  70 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
  71 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  72 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
  73 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
  74 bool dm_table_request_based(struct dm_table *t);
  75
  76 void dm_lock_md_type(struct mapped_device *md);
  77 void dm_unlock_md_type(struct mapped_device *md);
  78 enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
  79 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  80
  81 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
  82
  83 /*
  84  * To check whether the target type is bio-based or not (request-based).
  85  */
  86 #define dm_target_bio_based(t) ((t)->type->map != NULL)
  87
  88 /*
  89  * To check whether the target type is request-based or not (bio-based).
  90  */
  91 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
  92
  93 /*
  94  * To check whether the target type is a hybrid (capable of being
  95  * either request-based or bio-based).
  96  */
  97 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
  98
  99 /*
 100  * Zoned targets related functions.
 101  */
 102 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
 103                 struct queue_limits *lim);
 104 int dm_revalidate_zones(struct dm_table *t, struct request_queue *q);
 105 void dm_zone_endio(struct dm_io *io, struct bio *clone);
 106 #ifdef CONFIG_BLK_DEV_ZONED
 107 int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
 108                         unsigned int nr_zones, report_zones_cb cb, void *data);
 109 bool dm_is_zone_write(struct mapped_device *md, struct bio *bio);
 110 int dm_zone_get_reset_bitmap(struct mapped_device *md, struct dm_table *t,
 111                              sector_t sector, unsigned int nr_zones,
 112                              unsigned long *need_reset);
 113 #else
 114 #define dm_blk_report_zones     NULL
 115 static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
 116 {
 117         return false;
 118 }
 119 #endif
 120
 121 /*
 122  *---------------------------------------------------------------
 123  * A registry of target types.
 124  *---------------------------------------------------------------
 125  */
 126 int dm_target_init(void);
 127 void dm_target_exit(void);
 128 struct target_type *dm_get_target_type(const char *name);
 129 void dm_put_target_type(struct target_type *tt);
 130 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 131                                         void *param), void *param);
 132
 133 int dm_split_args(int *argc, char ***argvp, char *input);
 134
 135 /*
 136  * Is this mapped_device being deleted?
 137  */
 138 int dm_deleting_md(struct mapped_device *md);
 139
 140 /*
 141  * Is this mapped_device suspended?
 142  */
 143 int dm_suspended_md(struct mapped_device *md);
 144
 145 /*
 146  * Internal suspend and resume methods.
 147  */
 148 int dm_suspended_internally_md(struct mapped_device *md);
 149 void dm_internal_suspend_fast(struct mapped_device *md);
 150 void dm_internal_resume_fast(struct mapped_device *md);
 151 void dm_internal_suspend_noflush(struct mapped_device *md);
 152 void dm_internal_resume(struct mapped_device *md);
 153
 154 /*
 155  * Test if the device is scheduled for deferred remove.
 156  */
 157 int dm_test_deferred_remove_flag(struct mapped_device *md);
 158
 159 /*
 160  * Try to remove devices marked for deferred removal.
 161  */
 162 void dm_deferred_remove(void);
 163
 164 /*
 165  * The device-mapper can be driven through one of two interfaces;
 166  * ioctl or filesystem, depending which patch you have applied.
 167  */
 168 int dm_interface_init(void);
 169 void dm_interface_exit(void);
 170
 171 /*
 172  * sysfs interface
 173  */
 174 int dm_sysfs_init(struct mapped_device *md);
 175 void dm_sysfs_exit(struct mapped_device *md);
 176 struct kobject *dm_kobject(struct mapped_device *md);
 177 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 178
 179 /*
 180  * The kobject helper
 181  */
 182 void dm_kobject_release(struct kobject *kobj);
 183
 184 /*
 185  * Targets for linear and striped mappings
 186  */
 187 int linear_map(struct dm_target *ti, struct bio *bio);
 188 int dm_linear_init(void);
 189 void dm_linear_exit(void);
 190
 191 int stripe_map(struct dm_target *ti, struct bio *bio);
 192 int dm_stripe_init(void);
 193 void dm_stripe_exit(void);
 194
 195 /*
 196  * mapped_device operations
 197  */
 198 void dm_destroy(struct mapped_device *md);
 199 void dm_destroy_immediate(struct mapped_device *md);
 200 int dm_open_count(struct mapped_device *md);
 201 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
 202 int dm_cancel_deferred_remove(struct mapped_device *md);
 203 int dm_request_based(struct mapped_device *md);
 204 int dm_get_table_device(struct mapped_device *md, dev_t dev, blk_mode_t mode,
 205                         struct dm_dev **result);
 206 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
 207
 208 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 209                       unsigned int cookie, bool need_resize_uevent);
 210
 211 int dm_io_init(void);
 212 void dm_io_exit(void);
 213
 214 int dm_kcopyd_init(void);
 215 void dm_kcopyd_exit(void);
 216
 217 /*
 218  * Mempool operations
 219  */
 220 void dm_free_md_mempools(struct dm_md_mempools *pools);
 221
 222 /*
 223  * Various helpers
 224  */
 225 unsigned int dm_get_reserved_bio_based_ios(void);
 226
 227 #define DM_HASH_LOCKS_MAX 64
 228
 229 static inline unsigned int dm_num_hash_locks(void)
 230 {
 231         unsigned int num_locks = roundup_pow_of_two(num_online_cpus()) << 1;
 232
 233         return min_t(unsigned int, num_locks, DM_HASH_LOCKS_MAX);
 234 }
 235
 236 #define DM_HASH_LOCKS_MULT  4294967291ULL
 237 #define DM_HASH_LOCKS_SHIFT 6
 238
 239 static inline unsigned int dm_hash_locks_index(sector_t block,
 240                                                unsigned int num_locks)
 241 {
 242         sector_t h1 = (block * DM_HASH_LOCKS_MULT) >> DM_HASH_LOCKS_SHIFT;
 243         sector_t h2 = h1 >> DM_HASH_LOCKS_SHIFT;
 244
 245         return (h1 ^ h2) & (num_locks - 1);
 246 }
 247
 248 #endif