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 int dm_table_set_type(struct dm_table *t);
  63 unsigned dm_table_get_type(struct dm_table *t);
  64 bool dm_table_request_based(struct dm_table *t);
  65 int dm_table_alloc_md_mempools(struct dm_table *t);
  66 void dm_table_free_md_mempools(struct dm_table *t);
  67 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  68
  69 /*
  70  * To check the return value from dm_table_find_target().
  71  */
  72 #define dm_target_is_valid(t) ((t)->table)
  73
  74 /*
  75  * To check whether the target type is request-based or not (bio-based).
  76  */
  77 #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
  78
  79 /*-----------------------------------------------------------------
  80  * A registry of target types.
  81  *---------------------------------------------------------------*/
  82 int dm_target_init(void);
  83 void dm_target_exit(void);
  84 struct target_type *dm_get_target_type(const char *name);
  85 void dm_put_target_type(struct target_type *tt);
  86 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
  87                                         void *param), void *param);
  88
  89 int dm_split_args(int *argc, char ***argvp, char *input);
  90
  91 /*
  92  * Is this mapped_device being deleted?
  93  */
  94 int dm_deleting_md(struct mapped_device *md);
  95
  96 /*
  97  * Is this mapped_device suspended?
  98  */
  99 int dm_suspended_md(struct mapped_device *md);
 100
 101 /*
 102  * The device-mapper can be driven through one of two interfaces;
 103  * ioctl or filesystem, depending which patch you have applied.
 104  */
 105 int dm_interface_init(void);
 106 void dm_interface_exit(void);
 107
 108 /*
 109  * sysfs interface
 110  */
 111 int dm_sysfs_init(struct mapped_device *md);
 112 void dm_sysfs_exit(struct mapped_device *md);
 113 struct kobject *dm_kobject(struct mapped_device *md);
 114 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 115
 116 /*
 117  * Targets for linear and striped mappings
 118  */
 119 int dm_linear_init(void);
 120 void dm_linear_exit(void);
 121
 122 int dm_stripe_init(void);
 123 void dm_stripe_exit(void);
 124
 125 int dm_open_count(struct mapped_device *md);
 126 int dm_lock_for_deletion(struct mapped_device *md);
 127
 128 void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 129                        unsigned cookie);
 130
 131 int dm_io_init(void);
 132 void dm_io_exit(void);
 133
 134 int dm_kcopyd_init(void);
 135 void dm_kcopyd_exit(void);
 136
 137 /*
 138  * Mempool operations
 139  */
 140 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type);
 141 void dm_free_md_mempools(struct dm_md_mempools *pools);
 142
 143 #endif