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  * Suspend feature flags
  37  */
  38 #define DM_SUSPEND_LOCKFS_FLAG          (1 << 0)
  39
  40 /*
  41  * List of devices that a metadevice uses and should open/close.
  42  */
  43 struct dm_dev {
  44         struct list_head list;
  45
  46         atomic_t count;
  47         int mode;
  48         struct block_device *bdev;
  49         char name[16];
  50 };
  51
  52 struct dm_table;
  53
  54 /*-----------------------------------------------------------------
  55  * Internal table functions.
  56  *---------------------------------------------------------------*/
  57 void dm_table_event_callback(struct dm_table *t,
  58                              void (*fn)(void *), void *context);
  59 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  60 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  61 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
  62 struct list_head *dm_table_get_devices(struct dm_table *t);
  63 void dm_table_presuspend_targets(struct dm_table *t);
  64 void dm_table_postsuspend_targets(struct dm_table *t);
  65 int dm_table_resume_targets(struct dm_table *t);
  66 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  67 void dm_table_unplug_all(struct dm_table *t);
  68 int dm_table_flush_all(struct dm_table *t);
  69
  70 /*-----------------------------------------------------------------
  71  * A registry of target types.
  72  *---------------------------------------------------------------*/
  73 int dm_target_init(void);
  74 void dm_target_exit(void);
  75 struct target_type *dm_get_target_type(const char *name);
  76 void dm_put_target_type(struct target_type *t);
  77 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
  78                                         void *param), void *param);
  79
  80 /*-----------------------------------------------------------------
  81  * Useful inlines.
  82  *---------------------------------------------------------------*/
  83 static inline int array_too_big(unsigned long fixed, unsigned long obj,
  84                                 unsigned long num)
  85 {
  86         return (num > (ULONG_MAX - fixed) / obj);
  87 }
  88
  89 /*
  90  * Ceiling(n / sz)
  91  */
  92 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
  93
  94 #define dm_sector_div_up(n, sz) ( \
  95 { \
  96         sector_t _r = ((n) + (sz) - 1); \
  97         sector_div(_r, (sz)); \
  98         _r; \
  99 } \
 100 )
 101
 102 /*
 103  * ceiling(n / size) * size
 104  */
 105 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
 106
 107 static inline sector_t to_sector(unsigned long n)
 108 {
 109         return (n >> 9);
 110 }
 111
 112 static inline unsigned long to_bytes(sector_t n)
 113 {
 114         return (n << 9);
 115 }
 116
 117 int dm_split_args(int *argc, char ***argvp, char *input);
 118
 119 /*
 120  * The device-mapper can be driven through one of two interfaces;
 121  * ioctl or filesystem, depending which patch you have applied.
 122  */
 123 int dm_interface_init(void);
 124 void dm_interface_exit(void);
 125
 126 /*
 127  * Targets for linear and striped mappings
 128  */
 129 int dm_linear_init(void);
 130 void dm_linear_exit(void);
 131
 132 int dm_stripe_init(void);
 133 void dm_stripe_exit(void);
 134
 135 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 136 union map_info *dm_get_mapinfo(struct bio *bio);
 137 int dm_open_count(struct mapped_device *md);
 138 int dm_lock_for_deletion(struct mapped_device *md);
 139
 140 #endif