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
  25 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
  26                           0 : scnprintf(result + sz, maxlen - sz, x))
  27
  28 #define SECTOR_SHIFT 9
  29
  30 /*
  31  * List of devices that a metadevice uses and should open/close.
  32  */
  33 struct dm_dev {
  34         struct list_head list;
  35
  36         atomic_t count;
  37         int mode;
  38         struct block_device *bdev;
  39         char name[16];
  40 };
  41
  42 struct dm_table;
  43
  44 /*-----------------------------------------------------------------
  45  * Internal table functions.
  46  *---------------------------------------------------------------*/
  47 void dm_table_event_callback(struct dm_table *t,
  48                              void (*fn)(void *), void *context);
  49 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  50 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  51 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
  52 struct list_head *dm_table_get_devices(struct dm_table *t);
  53 void dm_table_presuspend_targets(struct dm_table *t);
  54 void dm_table_postsuspend_targets(struct dm_table *t);
  55 void dm_table_resume_targets(struct dm_table *t);
  56 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  57 void dm_table_unplug_all(struct dm_table *t);
  58 int dm_table_flush_all(struct dm_table *t);
  59
  60 /*-----------------------------------------------------------------
  61  * A registry of target types.
  62  *---------------------------------------------------------------*/
  63 int dm_target_init(void);
  64 void dm_target_exit(void);
  65 struct target_type *dm_get_target_type(const char *name);
  66 void dm_put_target_type(struct target_type *t);
  67 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
  68                                         void *param), void *param);
  69
  70 /*-----------------------------------------------------------------
  71  * Useful inlines.
  72  *---------------------------------------------------------------*/
  73 static inline int array_too_big(unsigned long fixed, unsigned long obj,
  74                                 unsigned long num)
  75 {
  76         return (num > (ULONG_MAX - fixed) / obj);
  77 }
  78
  79 /*
  80  * Ceiling(n / sz)
  81  */
  82 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
  83
  84 #define dm_sector_div_up(n, sz) ( \
  85 { \
  86         sector_t _r = ((n) + (sz) - 1); \
  87         sector_div(_r, (sz)); \
  88         _r; \
  89 } \
  90 )
  91
  92 /*
  93  * ceiling(n / size) * size
  94  */
  95 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
  96
  97 static inline sector_t to_sector(unsigned long n)
  98 {
  99         return (n >> 9);
 100 }
 101
 102 static inline unsigned long to_bytes(sector_t n)
 103 {
 104         return (n << 9);
 105 }
 106
 107 int dm_split_args(int *argc, char ***argvp, char *input);
 108
 109 /*
 110  * The device-mapper can be driven through one of two interfaces;
 111  * ioctl or filesystem, depending which patch you have applied.
 112  */
 113 int dm_interface_init(void);
 114 void dm_interface_exit(void);
 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 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 126 union map_info *dm_get_mapinfo(struct bio *bio);
 127 int dm_open_count(struct mapped_device *md);
 128 int dm_lock_for_deletion(struct mapped_device *md);
 129
 130 #endif