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 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_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 int dm_table_any_busy_target(struct dm_table *t);
  68 unsigned dm_table_get_type(struct dm_table *t);
  69 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  70 bool dm_table_request_based(struct dm_table *t);
  71 bool dm_table_supports_discards(struct dm_table *t);
  72 int dm_table_alloc_md_mempools(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
  76 int dm_queue_merge_is_compulsory(struct request_queue *q);
  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, unsigned type);
  81 unsigned 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);
  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 request-based or not (bio-based).
  93  */
  94 #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
  95
  96 /*-----------------------------------------------------------------
  97  * A registry of target types.
  98  *---------------------------------------------------------------*/
  99 int dm_target_init(void);
 100 void dm_target_exit(void);
 101 struct target_type *dm_get_target_type(const char *name);
 102 void dm_put_target_type(struct target_type *tt);
 103 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 104                                         void *param), void *param);
 105
 106 int dm_split_args(int *argc, char ***argvp, char *input);
 107
 108 /*
 109  * Is this mapped_device being deleted?
 110  */
 111 int dm_deleting_md(struct mapped_device *md);
 112
 113 /*
 114  * Is this mapped_device suspended?
 115  */
 116 int dm_suspended_md(struct mapped_device *md);
 117
 118 /*
 119  * The device-mapper can be driven through one of two interfaces;
 120  * ioctl or filesystem, depending which patch you have applied.
 121  */
 122 int dm_interface_init(void);
 123 void dm_interface_exit(void);
 124
 125 /*
 126  * sysfs interface
 127  */
 128 int dm_sysfs_init(struct mapped_device *md);
 129 void dm_sysfs_exit(struct mapped_device *md);
 130 struct kobject *dm_kobject(struct mapped_device *md);
 131 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 132
 133 /*
 134  * Targets for linear and striped mappings
 135  */
 136 int dm_linear_init(void);
 137 void dm_linear_exit(void);
 138
 139 int dm_stripe_init(void);
 140 void dm_stripe_exit(void);
 141
 142 /*
 143  * mapped_device operations
 144  */
 145 void dm_destroy(struct mapped_device *md);
 146 void dm_destroy_immediate(struct mapped_device *md);
 147 int dm_open_count(struct mapped_device *md);
 148 int dm_lock_for_deletion(struct mapped_device *md);
 149
 150 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 151                       unsigned cookie);
 152
 153 int dm_io_init(void);
 154 void dm_io_exit(void);
 155
 156 int dm_kcopyd_init(void);
 157 void dm_kcopyd_exit(void);
 158
 159 /*
 160  * Mempool operations
 161  */
 162 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
 163 void dm_free_md_mempools(struct dm_md_mempools *pools);
 164
 165 #endif