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/moduleparam.h> 17 #include <linux/blkdev.h> 18 #include <linux/backing-dev.h> 19 #include <linux/hdreg.h> 20 #include <linux/completion.h> 21 #include <linux/kobject.h> 22 #include <linux/refcount.h> 23 #include <linux/log2.h> 24 25 #include "dm-stats.h" 26 27 /* 28 * Suspend feature flags 29 */ 30 #define DM_SUSPEND_LOCKFS_FLAG (1 << 0) 31 #define DM_SUSPEND_NOFLUSH_FLAG (1 << 1) 32 33 /* 34 * Status feature flags 35 */ 36 #define DM_STATUS_NOFLUSH_FLAG (1 << 0) 37 38 /* 39 * List of devices that a metadevice uses and should open/close. 40 */ 41 struct dm_dev_internal { 42 struct list_head list; 43 refcount_t count; 44 struct dm_dev *dm_dev; 45 }; 46 47 struct dm_table; 48 struct dm_md_mempools; 49 struct dm_target_io; 50 struct dm_io; 51 52 /* 53 *--------------------------------------------------------------- 54 * Internal table functions. 55 *--------------------------------------------------------------- 56 */ 57 void dm_table_event_callback(struct dm_table *t, 58 void (*fn)(void *), void *context); 59 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector); 60 bool dm_table_has_no_data_devices(struct dm_table *table); 61 int dm_calculate_queue_limits(struct dm_table *table, 62 struct queue_limits *limits); 63 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 64 struct queue_limits *limits); 65 struct list_head *dm_table_get_devices(struct dm_table *t); 66 void dm_table_presuspend_targets(struct dm_table *t); 67 void dm_table_presuspend_undo_targets(struct dm_table *t); 68 void dm_table_postsuspend_targets(struct dm_table *t); 69 int dm_table_resume_targets(struct dm_table *t); 70 enum dm_queue_mode dm_table_get_type(struct dm_table *t); 71 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t); 72 struct dm_target *dm_table_get_immutable_target(struct dm_table *t); 73 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t); 74 bool dm_table_bio_based(struct dm_table *t); 75 bool dm_table_request_based(struct dm_table *t); 76 77 void dm_lock_md_type(struct mapped_device *md); 78 void dm_unlock_md_type(struct mapped_device *md); 79 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type); 80 enum dm_queue_mode dm_get_md_type(struct mapped_device *md); 81 struct target_type *dm_get_immutable_target_type(struct mapped_device *md); 82 83 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t); 84 85 /* 86 * To check whether the target type is bio-based or not (request-based). 87 */ 88 #define dm_target_bio_based(t) ((t)->type->map != NULL) 89 90 /* 91 * To check whether the target type is request-based or not (bio-based). 92 */ 93 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL) 94 95 /* 96 * To check whether the target type is a hybrid (capable of being 97 * either request-based or bio-based). 98 */ 99 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t)) 100 101 /* 102 * Zoned targets related functions. 103 */ 104 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q, 105 struct queue_limits *lim); 106 int dm_revalidate_zones(struct dm_table *t, struct request_queue *q); 107 void dm_zone_endio(struct dm_io *io, struct bio *clone); 108 #ifdef CONFIG_BLK_DEV_ZONED 109 int dm_blk_report_zones(struct gendisk *disk, sector_t sector, 110 unsigned int nr_zones, report_zones_cb cb, void *data); 111 bool dm_is_zone_write(struct mapped_device *md, struct bio *bio); 112 int dm_zone_map_bio(struct dm_target_io *io); 113 int dm_zone_get_reset_bitmap(struct mapped_device *md, struct dm_table *t, 114 sector_t sector, unsigned int nr_zones, 115 unsigned long *need_reset); 116 #else 117 #define dm_blk_report_zones NULL 118 static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio) 119 { 120 return false; 121 } 122 static inline int dm_zone_map_bio(struct dm_target_io *tio) 123 { 124 return DM_MAPIO_KILL; 125 } 126 #endif 127 128 /* 129 *--------------------------------------------------------------- 130 * A registry of target types. 131 *--------------------------------------------------------------- 132 */ 133 int dm_target_init(void); 134 void dm_target_exit(void); 135 struct target_type *dm_get_target_type(const char *name); 136 void dm_put_target_type(struct target_type *tt); 137 int dm_target_iterate(void (*iter_func)(struct target_type *tt, 138 void *param), void *param); 139 140 int dm_split_args(int *argc, char ***argvp, char *input); 141 142 /* 143 * Is this mapped_device being deleted? 144 */ 145 int dm_deleting_md(struct mapped_device *md); 146 147 /* 148 * Is this mapped_device suspended? 149 */ 150 int dm_suspended_md(struct mapped_device *md); 151 152 /* 153 * Internal suspend and resume methods. 154 */ 155 int dm_suspended_internally_md(struct mapped_device *md); 156 void dm_internal_suspend_fast(struct mapped_device *md); 157 void dm_internal_resume_fast(struct mapped_device *md); 158 void dm_internal_suspend_noflush(struct mapped_device *md); 159 void dm_internal_resume(struct mapped_device *md); 160 161 /* 162 * Test if the device is scheduled for deferred remove. 163 */ 164 int dm_test_deferred_remove_flag(struct mapped_device *md); 165 166 /* 167 * Try to remove devices marked for deferred removal. 168 */ 169 void dm_deferred_remove(void); 170 171 /* 172 * The device-mapper can be driven through one of two interfaces; 173 * ioctl or filesystem, depending which patch you have applied. 174 */ 175 int dm_interface_init(void); 176 void dm_interface_exit(void); 177 178 /* 179 * sysfs interface 180 */ 181 int dm_sysfs_init(struct mapped_device *md); 182 void dm_sysfs_exit(struct mapped_device *md); 183 struct kobject *dm_kobject(struct mapped_device *md); 184 struct mapped_device *dm_get_from_kobject(struct kobject *kobj); 185 186 /* 187 * The kobject helper 188 */ 189 void dm_kobject_release(struct kobject *kobj); 190 191 /* 192 * Targets for linear and striped mappings 193 */ 194 int linear_map(struct dm_target *ti, struct bio *bio); 195 int dm_linear_init(void); 196 void dm_linear_exit(void); 197 198 int stripe_map(struct dm_target *ti, struct bio *bio); 199 int dm_stripe_init(void); 200 void dm_stripe_exit(void); 201 202 /* 203 * mapped_device operations 204 */ 205 void dm_destroy(struct mapped_device *md); 206 void dm_destroy_immediate(struct mapped_device *md); 207 int dm_open_count(struct mapped_device *md); 208 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); 209 int dm_cancel_deferred_remove(struct mapped_device *md); 210 int dm_request_based(struct mapped_device *md); 211 int dm_get_table_device(struct mapped_device *md, dev_t dev, blk_mode_t mode, 212 struct dm_dev **result); 213 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d); 214 215 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, 216 unsigned int cookie, bool need_resize_uevent); 217 218 int dm_io_init(void); 219 void dm_io_exit(void); 220 221 int dm_kcopyd_init(void); 222 void dm_kcopyd_exit(void); 223 224 /* 225 * Mempool operations 226 */ 227 void dm_free_md_mempools(struct dm_md_mempools *pools); 228 229 /* 230 * Various helpers 231 */ 232 unsigned int dm_get_reserved_bio_based_ios(void); 233 234 #define DM_HASH_LOCKS_MAX 64 235 236 static inline unsigned int dm_num_hash_locks(void) 237 { 238 unsigned int num_locks = roundup_pow_of_two(num_online_cpus()) << 1; 239 240 return min_t(unsigned int, num_locks, DM_HASH_LOCKS_MAX); 241 } 242 243 #define DM_HASH_LOCKS_MULT 4294967291ULL 244 #define DM_HASH_LOCKS_SHIFT 6 245 246 static inline unsigned int dm_hash_locks_index(sector_t block, 247 unsigned int num_locks) 248 { 249 sector_t h1 = (block * DM_HASH_LOCKS_MULT) >> DM_HASH_LOCKS_SHIFT; 250 sector_t h2 = h1 >> DM_HASH_LOCKS_SHIFT; 251 252 return (h1 ^ h2) & (num_locks - 1); 253 } 254 255 #endif 256