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 void dm_zone_endio(struct dm_io *io, struct bio *clone); 106 #ifdef CONFIG_BLK_DEV_ZONED 107 void dm_cleanup_zoned_dev(struct mapped_device *md); 108 int dm_blk_report_zones(struct gendisk *disk, sector_t sector, 109 unsigned int nr_zones, report_zones_cb cb, void *data); 110 bool dm_is_zone_write(struct mapped_device *md, struct bio *bio); 111 int dm_zone_map_bio(struct dm_target_io *io); 112 #else 113 static inline void dm_cleanup_zoned_dev(struct mapped_device *md) {} 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 static inline int dm_zone_map_bio(struct dm_target_io *tio) 120 { 121 return DM_MAPIO_KILL; 122 } 123 #endif 124 125 /* 126 *--------------------------------------------------------------- 127 * A registry of target types. 128 *--------------------------------------------------------------- 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 *tt); 134 int dm_target_iterate(void (*iter_func)(struct target_type *tt, 135 void *param), void *param); 136 137 int dm_split_args(int *argc, char ***argvp, char *input); 138 139 /* 140 * Is this mapped_device being deleted? 141 */ 142 int dm_deleting_md(struct mapped_device *md); 143 144 /* 145 * Is this mapped_device suspended? 146 */ 147 int dm_suspended_md(struct mapped_device *md); 148 149 /* 150 * Internal suspend and resume methods. 151 */ 152 int dm_suspended_internally_md(struct mapped_device *md); 153 void dm_internal_suspend_fast(struct mapped_device *md); 154 void dm_internal_resume_fast(struct mapped_device *md); 155 void dm_internal_suspend_noflush(struct mapped_device *md); 156 void dm_internal_resume(struct mapped_device *md); 157 158 /* 159 * Test if the device is scheduled for deferred remove. 160 */ 161 int dm_test_deferred_remove_flag(struct mapped_device *md); 162 163 /* 164 * Try to remove devices marked for deferred removal. 165 */ 166 void dm_deferred_remove(void); 167 168 /* 169 * The device-mapper can be driven through one of two interfaces; 170 * ioctl or filesystem, depending which patch you have applied. 171 */ 172 int dm_interface_init(void); 173 void dm_interface_exit(void); 174 175 /* 176 * sysfs interface 177 */ 178 int dm_sysfs_init(struct mapped_device *md); 179 void dm_sysfs_exit(struct mapped_device *md); 180 struct kobject *dm_kobject(struct mapped_device *md); 181 struct mapped_device *dm_get_from_kobject(struct kobject *kobj); 182 183 /* 184 * The kobject helper 185 */ 186 void dm_kobject_release(struct kobject *kobj); 187 188 /* 189 * Targets for linear and striped mappings 190 */ 191 int dm_linear_init(void); 192 void dm_linear_exit(void); 193 194 int dm_stripe_init(void); 195 void dm_stripe_exit(void); 196 197 /* 198 * mapped_device operations 199 */ 200 void dm_destroy(struct mapped_device *md); 201 void dm_destroy_immediate(struct mapped_device *md); 202 int dm_open_count(struct mapped_device *md); 203 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); 204 int dm_cancel_deferred_remove(struct mapped_device *md); 205 int dm_request_based(struct mapped_device *md); 206 int dm_get_table_device(struct mapped_device *md, dev_t dev, blk_mode_t mode, 207 struct dm_dev **result); 208 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d); 209 210 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, 211 unsigned int cookie, bool need_resize_uevent); 212 213 int dm_io_init(void); 214 void dm_io_exit(void); 215 216 int dm_kcopyd_init(void); 217 void dm_kcopyd_exit(void); 218 219 /* 220 * Mempool operations 221 */ 222 void dm_free_md_mempools(struct dm_md_mempools *pools); 223 224 /* 225 * Various helpers 226 */ 227 unsigned int dm_get_reserved_bio_based_ios(void); 228 229 #define DM_HASH_LOCKS_MAX 64 230 231 static inline unsigned int dm_num_hash_locks(void) 232 { 233 unsigned int num_locks = roundup_pow_of_two(num_online_cpus()) << 1; 234 235 return min_t(unsigned int, num_locks, DM_HASH_LOCKS_MAX); 236 } 237 238 #define DM_HASH_LOCKS_MULT 4294967291ULL 239 #define DM_HASH_LOCKS_SHIFT 6 240 241 static inline unsigned int dm_hash_locks_index(sector_t block, 242 unsigned int num_locks) 243 { 244 sector_t h1 = (block * DM_HASH_LOCKS_MULT) >> DM_HASH_LOCKS_SHIFT; 245 sector_t h2 = h1 >> DM_HASH_LOCKS_SHIFT; 246 247 return (h1 ^ h2) & (num_locks - 1); 248 } 249 250 #endif 251