1 /* 2 * Internal header file for device mapper 3 * 4 * Copyright (C) 2001, 2002 Sistina Software 5 * Copyright (C) 2004 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 18 #define DM_NAME "device-mapper" 19 #define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x) 20 #define DMERR(f, x...) printk(KERN_ERR DM_NAME ": " f "\n" , ## x) 21 #define DMINFO(f, x...) printk(KERN_INFO DM_NAME ": " f "\n" , ## x) 22 23 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ 24 0 : scnprintf(result + sz, maxlen - sz, x)) 25 26 /* 27 * FIXME: I think this should be with the definition of sector_t 28 * in types.h. 29 */ 30 #ifdef CONFIG_LBD 31 #define SECTOR_FORMAT "%llu" 32 #else 33 #define SECTOR_FORMAT "%lu" 34 #endif 35 36 #define SECTOR_SHIFT 9 37 38 /* 39 * List of devices that a metadevice uses and should open/close. 40 */ 41 struct dm_dev { 42 struct list_head list; 43 44 atomic_t count; 45 int mode; 46 struct block_device *bdev; 47 char name[16]; 48 }; 49 50 struct dm_table; 51 struct mapped_device; 52 53 /*----------------------------------------------------------------- 54 * Functions for manipulating a struct mapped_device. 55 * Drop the reference with dm_put when you finish with the object. 56 *---------------------------------------------------------------*/ 57 int dm_create(struct mapped_device **md); 58 int dm_create_with_minor(unsigned int minor, struct mapped_device **md); 59 void dm_set_mdptr(struct mapped_device *md, void *ptr); 60 void *dm_get_mdptr(dev_t dev); 61 struct mapped_device *dm_get_md(dev_t dev); 62 63 /* 64 * Reference counting for md. 65 */ 66 void dm_get(struct mapped_device *md); 67 void dm_put(struct mapped_device *md); 68 69 /* 70 * A device can still be used while suspended, but I/O is deferred. 71 */ 72 int dm_suspend(struct mapped_device *md, int with_lockfs); 73 int dm_resume(struct mapped_device *md); 74 75 /* 76 * The device must be suspended before calling this method. 77 */ 78 int dm_swap_table(struct mapped_device *md, struct dm_table *t); 79 80 /* 81 * Drop a reference on the table when you've finished with the 82 * result. 83 */ 84 struct dm_table *dm_get_table(struct mapped_device *md); 85 86 /* 87 * Event functions. 88 */ 89 uint32_t dm_get_event_nr(struct mapped_device *md); 90 int dm_wait_event(struct mapped_device *md, int event_nr); 91 92 /* 93 * Info functions. 94 */ 95 struct gendisk *dm_disk(struct mapped_device *md); 96 int dm_suspended(struct mapped_device *md); 97 98 /*----------------------------------------------------------------- 99 * Functions for manipulating a table. Tables are also reference 100 * counted. 101 *---------------------------------------------------------------*/ 102 int dm_table_create(struct dm_table **result, int mode, unsigned num_targets); 103 104 void dm_table_get(struct dm_table *t); 105 void dm_table_put(struct dm_table *t); 106 107 int dm_table_add_target(struct dm_table *t, const char *type, 108 sector_t start, sector_t len, char *params); 109 int dm_table_complete(struct dm_table *t); 110 void dm_table_event_callback(struct dm_table *t, 111 void (*fn)(void *), void *context); 112 void dm_table_event(struct dm_table *t); 113 sector_t dm_table_get_size(struct dm_table *t); 114 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index); 115 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector); 116 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q); 117 unsigned int dm_table_get_num_targets(struct dm_table *t); 118 struct list_head *dm_table_get_devices(struct dm_table *t); 119 int dm_table_get_mode(struct dm_table *t); 120 void dm_table_presuspend_targets(struct dm_table *t); 121 void dm_table_postsuspend_targets(struct dm_table *t); 122 void dm_table_resume_targets(struct dm_table *t); 123 int dm_table_any_congested(struct dm_table *t, int bdi_bits); 124 void dm_table_unplug_all(struct dm_table *t); 125 int dm_table_flush_all(struct dm_table *t); 126 127 /*----------------------------------------------------------------- 128 * A registry of target types. 129 *---------------------------------------------------------------*/ 130 int dm_target_init(void); 131 void dm_target_exit(void); 132 struct target_type *dm_get_target_type(const char *name); 133 void dm_put_target_type(struct target_type *t); 134 int dm_target_iterate(void (*iter_func)(struct target_type *tt, 135 void *param), void *param); 136 137 138 /*----------------------------------------------------------------- 139 * Useful inlines. 140 *---------------------------------------------------------------*/ 141 static inline int array_too_big(unsigned long fixed, unsigned long obj, 142 unsigned long num) 143 { 144 return (num > (ULONG_MAX - fixed) / obj); 145 } 146 147 /* 148 * Ceiling(n / sz) 149 */ 150 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz)) 151 152 #define dm_sector_div_up(n, sz) ( \ 153 { \ 154 sector_t _r = ((n) + (sz) - 1); \ 155 sector_div(_r, (sz)); \ 156 _r; \ 157 } \ 158 ) 159 160 /* 161 * ceiling(n / size) * size 162 */ 163 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz)) 164 165 static inline sector_t to_sector(unsigned long n) 166 { 167 return (n >> 9); 168 } 169 170 static inline unsigned long to_bytes(sector_t n) 171 { 172 return (n << 9); 173 } 174 175 int dm_split_args(int *argc, char ***argvp, char *input); 176 177 /* 178 * The device-mapper can be driven through one of two interfaces; 179 * ioctl or filesystem, depending which patch you have applied. 180 */ 181 int dm_interface_init(void); 182 void dm_interface_exit(void); 183 184 /* 185 * Targets for linear and striped mappings 186 */ 187 int dm_linear_init(void); 188 void dm_linear_exit(void); 189 190 int dm_stripe_init(void); 191 void dm_stripe_exit(void); 192 193 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); 194 union map_info *dm_get_mapinfo(struct bio *bio); 195 196 #endif 197