drivers/md/dm.h

   1 /*
   2  * Internal header file for device mapper
   3  *
   4  * Copyright (C) 2001, 2002 Sistina Software
   5  * Copyright (C) 2004 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
  18 #define DM_NAME "device-mapper"
  19 #define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x)
  20 #define DMERR(f, x...) printk(KERN_ERR DM_NAME ": " f "\n" , ## x)
  21 #define DMINFO(f, x...) printk(KERN_INFO DM_NAME ": " f "\n" , ## x)
  22
  23 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
  24                           0 : scnprintf(result + sz, maxlen - sz, x))
  25
  26 /*
  27  * FIXME: I think this should be with the definition of sector_t
  28  * in types.h.
  29  */
  30 #ifdef CONFIG_LBD
  31 #define SECTOR_FORMAT "%llu"
  32 #else
  33 #define SECTOR_FORMAT "%lu"
  34 #endif
  35
  36 #define SECTOR_SHIFT 9
  37
  38 /*
  39  * List of devices that a metadevice uses and should open/close.
  40  */
  41 struct dm_dev {
  42         struct list_head list;
  43
  44         atomic_t count;
  45         int mode;
  46         struct block_device *bdev;
  47         char name[16];
  48 };
  49
  50 struct dm_table;
  51 struct mapped_device;
  52
  53 /*-----------------------------------------------------------------
  54  * Functions for manipulating a struct mapped_device.
  55  * Drop the reference with dm_put when you finish with the object.
  56  *---------------------------------------------------------------*/
  57 int dm_create(struct mapped_device **md);
  58 int dm_create_with_minor(unsigned int minor, struct mapped_device **md);
  59 void dm_set_mdptr(struct mapped_device *md, void *ptr);
  60 void *dm_get_mdptr(dev_t dev);
  61 struct mapped_device *dm_get_md(dev_t dev);
  62
  63 /*
  64  * Reference counting for md.
  65  */
  66 void dm_get(struct mapped_device *md);
  67 void dm_put(struct mapped_device *md);
  68
  69 /*
  70  * A device can still be used while suspended, but I/O is deferred.
  71  */
  72 int dm_suspend(struct mapped_device *md, int with_lockfs);
  73 int dm_resume(struct mapped_device *md);
  74
  75 /*
  76  * The device must be suspended before calling this method.
  77  */
  78 int dm_swap_table(struct mapped_device *md, struct dm_table *t);
  79
  80 /*
  81  * Drop a reference on the table when you've finished with the
  82  * result.
  83  */
  84 struct dm_table *dm_get_table(struct mapped_device *md);
  85
  86 /*
  87  * Event functions.
  88  */
  89 uint32_t dm_get_event_nr(struct mapped_device *md);
  90 int dm_wait_event(struct mapped_device *md, int event_nr);
  91
  92 /*
  93  * Info functions.
  94  */
  95 struct gendisk *dm_disk(struct mapped_device *md);
  96 int dm_suspended(struct mapped_device *md);
  97
  98 /*-----------------------------------------------------------------
  99  * Functions for manipulating a table.  Tables are also reference
 100  * counted.
 101  *---------------------------------------------------------------*/
 102 int dm_table_create(struct dm_table **result, int mode, unsigned num_targets);
 103
 104 void dm_table_get(struct dm_table *t);
 105 void dm_table_put(struct dm_table *t);
 106
 107 int dm_table_add_target(struct dm_table *t, const char *type,
 108                         sector_t start, sector_t len, char *params);
 109 int dm_table_complete(struct dm_table *t);
 110 void dm_table_event_callback(struct dm_table *t,
 111                              void (*fn)(void *), void *context);
 112 void dm_table_event(struct dm_table *t);
 113 sector_t dm_table_get_size(struct dm_table *t);
 114 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
 115 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
 116 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
 117 unsigned int dm_table_get_num_targets(struct dm_table *t);
 118 struct list_head *dm_table_get_devices(struct dm_table *t);
 119 int dm_table_get_mode(struct dm_table *t);
 120 void dm_table_presuspend_targets(struct dm_table *t);
 121 void dm_table_postsuspend_targets(struct dm_table *t);
 122 void dm_table_resume_targets(struct dm_table *t);
 123 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
 124 void dm_table_unplug_all(struct dm_table *t);
 125 int dm_table_flush_all(struct dm_table *t);
 126
 127 /*-----------------------------------------------------------------
 128  * A registry of target types.
 129  *---------------------------------------------------------------*/
 130 int dm_target_init(void);
 131 void dm_target_exit(void);
 132 struct target_type *dm_get_target_type(const char *name);
 133 void dm_put_target_type(struct target_type *t);
 134 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 135                                         void *param), void *param);
 136
 137
 138 /*-----------------------------------------------------------------
 139  * Useful inlines.
 140  *---------------------------------------------------------------*/
 141 static inline int array_too_big(unsigned long fixed, unsigned long obj,
 142                                 unsigned long num)
 143 {
 144         return (num > (ULONG_MAX - fixed) / obj);
 145 }
 146
 147 /*
 148  * Ceiling(n / sz)
 149  */
 150 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
 151
 152 #define dm_sector_div_up(n, sz) ( \
 153 { \
 154         sector_t _r = ((n) + (sz) - 1); \
 155         sector_div(_r, (sz)); \
 156         _r; \
 157 } \
 158 )
 159
 160 /*
 161  * ceiling(n / size) * size
 162  */
 163 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
 164
 165 static inline sector_t to_sector(unsigned long n)
 166 {
 167         return (n >> 9);
 168 }
 169
 170 static inline unsigned long to_bytes(sector_t n)
 171 {
 172         return (n << 9);
 173 }
 174
 175 int dm_split_args(int *argc, char ***argvp, char *input);
 176
 177 /*
 178  * The device-mapper can be driven through one of two interfaces;
 179  * ioctl or filesystem, depending which patch you have applied.
 180  */
 181 int dm_interface_init(void);
 182 void dm_interface_exit(void);
 183
 184 /*
 185  * Targets for linear and striped mappings
 186  */
 187 int dm_linear_init(void);
 188 void dm_linear_exit(void);
 189
 190 int dm_stripe_init(void);
 191 void dm_stripe_exit(void);
 192
 193 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 194 union map_info *dm_get_mapinfo(struct bio *bio);
 195
 196 #endif