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...) \
  22         printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
  23 #define DMERR_LIMIT(f, arg...) \
  24         do { \
  25                 if (printk_ratelimit()) \
  26                         printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
  27                                f "\n", ## arg); \
  28         } while (0)
  29
  30 #define DMWARN(f, arg...) \
  31         printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
  32 #define DMWARN_LIMIT(f, arg...) \
  33         do { \
  34                 if (printk_ratelimit()) \
  35                         printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
  36                                f "\n", ## arg); \
  37         } while (0)
  38
  39 #define DMINFO(f, arg...) \
  40         printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
  41 #define DMINFO_LIMIT(f, arg...) \
  42         do { \
  43                 if (printk_ratelimit()) \
  44                         printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
  45                                "\n", ## arg); \
  46         } while (0)
  47
  48 #ifdef CONFIG_DM_DEBUG
  49 #  define DMDEBUG(f, arg...) \
  50         printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
  51 #  define DMDEBUG_LIMIT(f, arg...) \
  52         do { \
  53                 if (printk_ratelimit()) \
  54                         printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
  55                                "\n", ## arg); \
  56         } while (0)
  57 #else
  58 #  define DMDEBUG(f, arg...) do {} while (0)
  59 #  define DMDEBUG_LIMIT(f, arg...) do {} while (0)
  60 #endif
  61
  62 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
  63                           0 : scnprintf(result + sz, maxlen - sz, x))
  64
  65 #define SECTOR_SHIFT 9
  66
  67 /*
  68  * Definitions of return values from target end_io function.
  69  */
  70 #define DM_ENDIO_INCOMPLETE     1
  71 #define DM_ENDIO_REQUEUE        2
  72
  73 /*
  74  * Definitions of return values from target map function.
  75  */
  76 #define DM_MAPIO_SUBMITTED      0
  77 #define DM_MAPIO_REMAPPED       1
  78 #define DM_MAPIO_REQUEUE        DM_ENDIO_REQUEUE
  79
  80 /*
  81  * Suspend feature flags
  82  */
  83 #define DM_SUSPEND_LOCKFS_FLAG          (1 << 0)
  84 #define DM_SUSPEND_NOFLUSH_FLAG         (1 << 1)
  85
  86 /*
  87  * List of devices that a metadevice uses and should open/close.
  88  */
  89 struct dm_dev {
  90         struct list_head list;
  91
  92         atomic_t count;
  93         int mode;
  94         struct block_device *bdev;
  95         char name[16];
  96 };
  97
  98 struct dm_table;
  99
 100 /*-----------------------------------------------------------------
 101  * Internal table functions.
 102  *---------------------------------------------------------------*/
 103 void dm_table_event_callback(struct dm_table *t,
 104                              void (*fn)(void *), void *context);
 105 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
 106 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
 107 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
 108 struct list_head *dm_table_get_devices(struct dm_table *t);
 109 void dm_table_presuspend_targets(struct dm_table *t);
 110 void dm_table_postsuspend_targets(struct dm_table *t);
 111 int dm_table_resume_targets(struct dm_table *t);
 112 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
 113 void dm_table_unplug_all(struct dm_table *t);
 114
 115 /*-----------------------------------------------------------------
 116  * A registry of target types.
 117  *---------------------------------------------------------------*/
 118 int dm_target_init(void);
 119 void dm_target_exit(void);
 120 struct target_type *dm_get_target_type(const char *name);
 121 void dm_put_target_type(struct target_type *t);
 122 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 123                                         void *param), void *param);
 124
 125 /*-----------------------------------------------------------------
 126  * Useful inlines.
 127  *---------------------------------------------------------------*/
 128 static inline int array_too_big(unsigned long fixed, unsigned long obj,
 129                                 unsigned long num)
 130 {
 131         return (num > (ULONG_MAX - fixed) / obj);
 132 }
 133
 134 /*
 135  * Ceiling(n / sz)
 136  */
 137 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
 138
 139 #define dm_sector_div_up(n, sz) ( \
 140 { \
 141         sector_t _r = ((n) + (sz) - 1); \
 142         sector_div(_r, (sz)); \
 143         _r; \
 144 } \
 145 )
 146
 147 /*
 148  * ceiling(n / size) * size
 149  */
 150 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
 151
 152 static inline sector_t to_sector(unsigned long n)
 153 {
 154         return (n >> 9);
 155 }
 156
 157 static inline unsigned long to_bytes(sector_t n)
 158 {
 159         return (n << 9);
 160 }
 161
 162 int dm_split_args(int *argc, char ***argvp, char *input);
 163
 164 /*
 165  * The device-mapper can be driven through one of two interfaces;
 166  * ioctl or filesystem, depending which patch you have applied.
 167  */
 168 int dm_interface_init(void);
 169 void dm_interface_exit(void);
 170
 171 /*
 172  * Targets for linear and striped mappings
 173  */
 174 int dm_linear_init(void);
 175 void dm_linear_exit(void);
 176
 177 int dm_stripe_init(void);
 178 void dm_stripe_exit(void);
 179
 180 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 181 union map_info *dm_get_mapinfo(struct bio *bio);
 182 int dm_open_count(struct mapped_device *md);
 183 int dm_lock_for_deletion(struct mapped_device *md);
 184
 185 #endif