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  * Definitions of return values from target end_io function.
  37  */
  38 #define DM_ENDIO_INCOMPLETE     1
  39 #define DM_ENDIO_REQUEUE        2
  40
  41 /*
  42  * Definitions of return values from target map function.
  43  */
  44 #define DM_MAPIO_SUBMITTED      0
  45 #define DM_MAPIO_REMAPPED       1
  46 #define DM_MAPIO_REQUEUE        DM_ENDIO_REQUEUE
  47
  48 /*
  49  * Suspend feature flags
  50  */
  51 #define DM_SUSPEND_LOCKFS_FLAG          (1 << 0)
  52 #define DM_SUSPEND_NOFLUSH_FLAG         (1 << 1)
  53
  54 /*
  55  * List of devices that a metadevice uses and should open/close.
  56  */
  57 struct dm_dev {
  58         struct list_head list;
  59
  60         atomic_t count;
  61         int mode;
  62         struct block_device *bdev;
  63         char name[16];
  64 };
  65
  66 struct dm_table;
  67
  68 /*-----------------------------------------------------------------
  69  * Internal table functions.
  70  *---------------------------------------------------------------*/
  71 void dm_table_event_callback(struct dm_table *t,
  72                              void (*fn)(void *), void *context);
  73 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  74 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  75 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
  76 struct list_head *dm_table_get_devices(struct dm_table *t);
  77 void dm_table_presuspend_targets(struct dm_table *t);
  78 void dm_table_postsuspend_targets(struct dm_table *t);
  79 int dm_table_resume_targets(struct dm_table *t);
  80 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  81 void dm_table_unplug_all(struct dm_table *t);
  82 int dm_table_flush_all(struct dm_table *t);
  83
  84 /*-----------------------------------------------------------------
  85  * A registry of target types.
  86  *---------------------------------------------------------------*/
  87 int dm_target_init(void);
  88 void dm_target_exit(void);
  89 struct target_type *dm_get_target_type(const char *name);
  90 void dm_put_target_type(struct target_type *t);
  91 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
  92                                         void *param), void *param);
  93
  94 /*-----------------------------------------------------------------
  95  * Useful inlines.
  96  *---------------------------------------------------------------*/
  97 static inline int array_too_big(unsigned long fixed, unsigned long obj,
  98                                 unsigned long num)
  99 {
 100         return (num > (ULONG_MAX - fixed) / obj);
 101 }
 102
 103 /*
 104  * Ceiling(n / sz)
 105  */
 106 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
 107
 108 #define dm_sector_div_up(n, sz) ( \
 109 { \
 110         sector_t _r = ((n) + (sz) - 1); \
 111         sector_div(_r, (sz)); \
 112         _r; \
 113 } \
 114 )
 115
 116 /*
 117  * ceiling(n / size) * size
 118  */
 119 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
 120
 121 static inline sector_t to_sector(unsigned long n)
 122 {
 123         return (n >> 9);
 124 }
 125
 126 static inline unsigned long to_bytes(sector_t n)
 127 {
 128         return (n << 9);
 129 }
 130
 131 int dm_split_args(int *argc, char ***argvp, char *input);
 132
 133 /*
 134  * The device-mapper can be driven through one of two interfaces;
 135  * ioctl or filesystem, depending which patch you have applied.
 136  */
 137 int dm_interface_init(void);
 138 void dm_interface_exit(void);
 139
 140 /*
 141  * Targets for linear and striped mappings
 142  */
 143 int dm_linear_init(void);
 144 void dm_linear_exit(void);
 145
 146 int dm_stripe_init(void);
 147 void dm_stripe_exit(void);
 148
 149 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 150 union map_info *dm_get_mapinfo(struct bio *bio);
 151 int dm_open_count(struct mapped_device *md);
 152 int dm_lock_for_deletion(struct mapped_device *md);
 153
 154 #endif