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