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 #define DM_NAME "device-mapper"
  20
  21 #define DMERR(f, arg...) printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
  22 #define DMWARN(f, arg...) printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
  23 #define DMINFO(f, arg...) printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
  24 #ifdef CONFIG_DM_DEBUG
  25 #  define DMDEBUG(f, arg...) printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
  26 #else
  27 #  define DMDEBUG(f, arg...) do {} while (0)
  28 #endif
  29
  30 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
  31                           0 : scnprintf(result + sz, maxlen - sz, x))
  32
  33 #define SECTOR_SHIFT 9
  34
  35 /*
  36  * List of devices that a metadevice uses and should open/close.
  37  */
  38 struct dm_dev {
  39         struct list_head list;
  40
  41         atomic_t count;
  42         int mode;
  43         struct block_device *bdev;
  44         char name[16];
  45 };
  46
  47 struct dm_table;
  48
  49 /*-----------------------------------------------------------------
  50  * Internal table functions.
  51  *---------------------------------------------------------------*/
  52 void dm_table_event_callback(struct dm_table *t,
  53                              void (*fn)(void *), void *context);
  54 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  55 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  56 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
  57 struct list_head *dm_table_get_devices(struct dm_table *t);
  58 void dm_table_presuspend_targets(struct dm_table *t);
  59 void dm_table_postsuspend_targets(struct dm_table *t);
  60 int dm_table_resume_targets(struct dm_table *t);
  61 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  62 void dm_table_unplug_all(struct dm_table *t);
  63 int dm_table_flush_all(struct dm_table *t);
  64
  65 /*-----------------------------------------------------------------
  66  * A registry of target types.
  67  *---------------------------------------------------------------*/
  68 int dm_target_init(void);
  69 void dm_target_exit(void);
  70 struct target_type *dm_get_target_type(const char *name);
  71 void dm_put_target_type(struct target_type *t);
  72 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
  73                                         void *param), void *param);
  74
  75 /*-----------------------------------------------------------------
  76  * Useful inlines.
  77  *---------------------------------------------------------------*/
  78 static inline int array_too_big(unsigned long fixed, unsigned long obj,
  79                                 unsigned long num)
  80 {
  81         return (num > (ULONG_MAX - fixed) / obj);
  82 }
  83
  84 /*
  85  * Ceiling(n / sz)
  86  */
  87 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
  88
  89 #define dm_sector_div_up(n, sz) ( \
  90 { \
  91         sector_t _r = ((n) + (sz) - 1); \
  92         sector_div(_r, (sz)); \
  93         _r; \
  94 } \
  95 )
  96
  97 /*
  98  * ceiling(n / size) * size
  99  */
 100 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
 101
 102 static inline sector_t to_sector(unsigned long n)
 103 {
 104         return (n >> 9);
 105 }
 106
 107 static inline unsigned long to_bytes(sector_t n)
 108 {
 109         return (n << 9);
 110 }
 111
 112 int dm_split_args(int *argc, char ***argvp, char *input);
 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  * Targets for linear and striped mappings
 123  */
 124 int dm_linear_init(void);
 125 void dm_linear_exit(void);
 126
 127 int dm_stripe_init(void);
 128 void dm_stripe_exit(void);
 129
 130 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 131 union map_info *dm_get_mapinfo(struct bio *bio);
 132 int dm_open_count(struct mapped_device *md);
 133 int dm_lock_for_deletion(struct mapped_device *md);
 134
 135 #endif