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 #include <linux/completion.h>
  19 #include <linux/kobject.h>
  20
  21 /*
  22  * Suspend feature flags
  23  */
  24 #define DM_SUSPEND_LOCKFS_FLAG          (1 << 0)
  25 #define DM_SUSPEND_NOFLUSH_FLAG         (1 << 1)
  26
  27 /*
  28  * Type of table and mapped_device's mempool
  29  */
  30 #define DM_TYPE_NONE            0
  31 #define DM_TYPE_BIO_BASED       1
  32 #define DM_TYPE_REQUEST_BASED   2
  33
  34 /*
  35  * List of devices that a metadevice uses and should open/close.
  36  */
  37 struct dm_dev_internal {
  38         struct list_head list;
  39         atomic_t count;
  40         struct dm_dev dm_dev;
  41 };
  42
  43 struct dm_table;
  44 struct dm_md_mempools;
  45
  46 /*-----------------------------------------------------------------
  47  * Internal table functions.
  48  *---------------------------------------------------------------*/
  49 void dm_table_destroy(struct dm_table *t);
  50 void dm_table_event_callback(struct dm_table *t,
  51                              void (*fn)(void *), void *context);
  52 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  53 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  54 int dm_calculate_queue_limits(struct dm_table *table,
  55                               struct queue_limits *limits);
  56 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  57                                struct queue_limits *limits);
  58 struct list_head *dm_table_get_devices(struct dm_table *t);
  59 void dm_table_presuspend_targets(struct dm_table *t);
  60 void dm_table_postsuspend_targets(struct dm_table *t);
  61 int dm_table_resume_targets(struct dm_table *t);
  62 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  63 int dm_table_any_busy_target(struct dm_table *t);
  64 unsigned dm_table_get_type(struct dm_table *t);
  65 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  66 bool dm_table_request_based(struct dm_table *t);
  67 bool dm_table_supports_discards(struct dm_table *t);
  68 int dm_table_alloc_md_mempools(struct dm_table *t);
  69 void dm_table_free_md_mempools(struct dm_table *t);
  70 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  71
  72 int dm_queue_merge_is_compulsory(struct request_queue *q);
  73
  74 void dm_lock_md_type(struct mapped_device *md);
  75 void dm_unlock_md_type(struct mapped_device *md);
  76 void dm_set_md_type(struct mapped_device *md, unsigned type);
  77 unsigned dm_get_md_type(struct mapped_device *md);
  78 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  79
  80 int dm_setup_md_queue(struct mapped_device *md);
  81
  82 /*
  83  * To check the return value from dm_table_find_target().
  84  */
  85 #define dm_target_is_valid(t) ((t)->table)
  86
  87 /*
  88  * To check whether the target type is request-based or not (bio-based).
  89  */
  90 #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
  91
  92 /*-----------------------------------------------------------------
  93  * A registry of target types.
  94  *---------------------------------------------------------------*/
  95 int dm_target_init(void);
  96 void dm_target_exit(void);
  97 struct target_type *dm_get_target_type(const char *name);
  98 void dm_put_target_type(struct target_type *tt);
  99 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 100                                         void *param), void *param);
 101
 102 int dm_split_args(int *argc, char ***argvp, char *input);
 103
 104 /*
 105  * Is this mapped_device being deleted?
 106  */
 107 int dm_deleting_md(struct mapped_device *md);
 108
 109 /*
 110  * Is this mapped_device suspended?
 111  */
 112 int dm_suspended_md(struct mapped_device *md);
 113
 114 /*
 115  * The device-mapper can be driven through one of two interfaces;
 116  * ioctl or filesystem, depending which patch you have applied.
 117  */
 118 int dm_interface_init(void);
 119 void dm_interface_exit(void);
 120
 121 /*
 122  * sysfs interface
 123  */
 124 struct dm_kobject_holder {
 125         struct kobject kobj;
 126         struct completion completion;
 127 };
 128
 129 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
 130 {
 131         return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
 132 }
 133
 134 int dm_sysfs_init(struct mapped_device *md);
 135 void dm_sysfs_exit(struct mapped_device *md);
 136 struct kobject *dm_kobject(struct mapped_device *md);
 137 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
 138
 139 /*
 140  * The kobject helper
 141  */
 142 void dm_kobject_release(struct kobject *kobj);
 143
 144 /*
 145  * Targets for linear and striped mappings
 146  */
 147 int dm_linear_init(void);
 148 void dm_linear_exit(void);
 149
 150 int dm_stripe_init(void);
 151 void dm_stripe_exit(void);
 152
 153 /*
 154  * mapped_device operations
 155  */
 156 void dm_destroy(struct mapped_device *md);
 157 void dm_destroy_immediate(struct mapped_device *md);
 158 int dm_open_count(struct mapped_device *md);
 159 int dm_lock_for_deletion(struct mapped_device *md);
 160
 161 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 162                       unsigned cookie);
 163
 164 int dm_io_init(void);
 165 void dm_io_exit(void);
 166
 167 int dm_kcopyd_init(void);
 168 void dm_kcopyd_exit(void);
 169
 170 /*
 171  * Mempool operations
 172  */
 173 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
 174 void dm_free_md_mempools(struct dm_md_mempools *pools);
 175
 176 #endif