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