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/blkdev.h>
  17 #include <linux/hdreg.h>
  18
  19 /*
  20  * Suspend feature flags
  21  */
  22 #define DM_SUSPEND_LOCKFS_FLAG          (1 << 0)
  23 #define DM_SUSPEND_NOFLUSH_FLAG         (1 << 1)
  24
  25 /*
  26  * Status feature flags
  27  */
  28 #define DM_STATUS_NOFLUSH_FLAG          (1 << 0)
  29
  30 /*
  31  * Type of table and mapped_device's mempool
  32  */
  33 #define DM_TYPE_NONE            0
  34 #define DM_TYPE_BIO_BASED       1
  35 #define DM_TYPE_REQUEST_BASED   2
  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         atomic_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 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_postsuspend_targets(struct dm_table *t);
  64 int dm_table_resume_targets(struct dm_table *t);
  65 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  66 int dm_table_any_busy_target(struct dm_table *t);
  67 unsigned dm_table_get_type(struct dm_table *t);
  68 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  69 bool dm_table_request_based(struct dm_table *t);
  70 bool dm_table_supports_discards(struct dm_table *t);
  71 int dm_table_alloc_md_mempools(struct dm_table *t);
  72 void dm_table_free_md_mempools(struct dm_table *t);
  73 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  74
  75 int dm_queue_merge_is_compulsory(struct request_queue *q);
  76
  77 void dm_lock_md_type(struct mapped_device *md);
  78 void dm_unlock_md_type(struct mapped_device *md);
  79 void dm_set_md_type(struct mapped_device *md, unsigned type);
  80 unsigned dm_get_md_type(struct mapped_device *md);
  81 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  82
  83 int dm_setup_md_queue(struct mapped_device *md);
  84
  85 /*
  86  * To check the return value from dm_table_find_target().
  87  */
  88 #define dm_target_is_valid(t) ((t)->table)
  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->map_rq != NULL)
  94
  95 /*-----------------------------------------------------------------
  96  * A registry of target types.
  97  *---------------------------------------------------------------*/
  98 int dm_target_init(void);
  99 void dm_target_exit(void);
 100 struct target_type *dm_get_target_type(const char *name);
 101 void dm_put_target_type(struct target_type *tt);
 102 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 103                                         void *param), void *param);
 104
 105 int dm_split_args(int *argc, char ***argvp, char *input);
 106
 107 /*
 108  * Is this mapped_device being deleted?
 109  */
 110 int dm_deleting_md(struct mapped_device *md);
 111
 112 /*
 113  * Is this mapped_device suspended?
 114  */
 115 int dm_suspended_md(struct mapped_device *md);
 116
 117 /*
 118  * The device-mapper can be driven through one of two interfaces;
 119  * ioctl or filesystem, depending which patch you have applied.
 120  */
 121 int dm_interface_init(void);
 122 void dm_interface_exit(void);
 123
 124 /*
 125  * sysfs interface
 126  */
 127 int dm_sysfs_init(struct mapped_device *md);
 128 void dm_sysfs_exit(struct mapped_device *md);
 129 struct kobject *dm_kobject(struct mapped_device *md);
 130 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 131
 132 /*
 133  * Targets for linear and striped mappings
 134  */
 135 int dm_linear_init(void);
 136 void dm_linear_exit(void);
 137
 138 int dm_stripe_init(void);
 139 void dm_stripe_exit(void);
 140
 141 /*
 142  * mapped_device operations
 143  */
 144 void dm_destroy(struct mapped_device *md);
 145 void dm_destroy_immediate(struct mapped_device *md);
 146 int dm_open_count(struct mapped_device *md);
 147 int dm_lock_for_deletion(struct mapped_device *md);
 148
 149 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 150                       unsigned cookie);
 151
 152 int dm_io_init(void);
 153 void dm_io_exit(void);
 154
 155 int dm_kcopyd_init(void);
 156 void dm_kcopyd_exit(void);
 157
 158 /*
 159  * Mempool operations
 160  */
 161 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
 162 void dm_free_md_mempools(struct dm_md_mempools *pools);
 163
 164 #endif