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