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  * Type of table and mapped_device's mempool
  27  */
  28 #define DM_TYPE_NONE            0
  29 #define DM_TYPE_BIO_BASED       1
  30 #define DM_TYPE_REQUEST_BASED   2
  31
  32 /*
  33  * List of devices that a metadevice uses and should open/close.
  34  */
  35 struct dm_dev_internal {
  36         struct list_head list;
  37         atomic_t count;
  38         struct dm_dev dm_dev;
  39 };
  40
  41 struct dm_table;
  42 struct dm_md_mempools;
  43
  44 /*-----------------------------------------------------------------
  45  * Internal table functions.
  46  *---------------------------------------------------------------*/
  47 void dm_table_destroy(struct dm_table *t);
  48 void dm_table_event_callback(struct dm_table *t,
  49                              void (*fn)(void *), void *context);
  50 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  51 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  52 int dm_calculate_queue_limits(struct dm_table *table,
  53                               struct queue_limits *limits);
  54 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  55                                struct queue_limits *limits);
  56 struct list_head *dm_table_get_devices(struct dm_table *t);
  57 void dm_table_presuspend_targets(struct dm_table *t);
  58 void dm_table_postsuspend_targets(struct dm_table *t);
  59 int dm_table_resume_targets(struct dm_table *t);
  60 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  61 int dm_table_any_busy_target(struct dm_table *t);
  62 unsigned dm_table_get_type(struct dm_table *t);
  63 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  64 bool dm_table_request_based(struct dm_table *t);
  65 bool dm_table_supports_discards(struct dm_table *t);
  66 int dm_table_alloc_md_mempools(struct dm_table *t);
  67 void dm_table_free_md_mempools(struct dm_table *t);
  68 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  69
  70 int dm_queue_merge_is_compulsory(struct request_queue *q);
  71
  72 void dm_lock_md_type(struct mapped_device *md);
  73 void dm_unlock_md_type(struct mapped_device *md);
  74 void dm_set_md_type(struct mapped_device *md, unsigned type);
  75 unsigned dm_get_md_type(struct mapped_device *md);
  76 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  77
  78 int dm_setup_md_queue(struct mapped_device *md);
  79
  80 /*
  81  * To check the return value from dm_table_find_target().
  82  */
  83 #define dm_target_is_valid(t) ((t)->table)
  84
  85 /*
  86  * To check whether the target type is request-based or not (bio-based).
  87  */
  88 #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
  89
  90 /*-----------------------------------------------------------------
  91  * A registry of target types.
  92  *---------------------------------------------------------------*/
  93 int dm_target_init(void);
  94 void dm_target_exit(void);
  95 struct target_type *dm_get_target_type(const char *name);
  96 void dm_put_target_type(struct target_type *tt);
  97 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
  98                                         void *param), void *param);
  99
 100 int dm_split_args(int *argc, char ***argvp, char *input);
 101
 102 /*
 103  * Is this mapped_device being deleted?
 104  */
 105 int dm_deleting_md(struct mapped_device *md);
 106
 107 /*
 108  * Is this mapped_device suspended?
 109  */
 110 int dm_suspended_md(struct mapped_device *md);
 111
 112 /*
 113  * The device-mapper can be driven through one of two interfaces;
 114  * ioctl or filesystem, depending which patch you have applied.
 115  */
 116 int dm_interface_init(void);
 117 void dm_interface_exit(void);
 118
 119 /*
 120  * sysfs interface
 121  */
 122 int dm_sysfs_init(struct mapped_device *md);
 123 void dm_sysfs_exit(struct mapped_device *md);
 124 struct kobject *dm_kobject(struct mapped_device *md);
 125 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 126
 127 /*
 128  * Targets for linear and striped mappings
 129  */
 130 int dm_linear_init(void);
 131 void dm_linear_exit(void);
 132
 133 int dm_stripe_init(void);
 134 void dm_stripe_exit(void);
 135
 136 /*
 137  * mapped_device operations
 138  */
 139 void dm_destroy(struct mapped_device *md);
 140 void dm_destroy_immediate(struct mapped_device *md);
 141 int dm_open_count(struct mapped_device *md);
 142 int dm_lock_for_deletion(struct mapped_device *md);
 143
 144 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 145                       unsigned cookie);
 146
 147 int dm_io_init(void);
 148 void dm_io_exit(void);
 149
 150 int dm_kcopyd_init(void);
 151 void dm_kcopyd_exit(void);
 152
 153 /*
 154  * Mempool operations
 155  */
 156 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
 157 void dm_free_md_mempools(struct dm_md_mempools *pools);
 158
 159 #endif