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 */ 41struct dm_dev_internal { 42 struct list_head list; 43 refcount_t count; 44 struct dm_dev *dm_dev; 45}; 46 47struct dm_table; 48struct dm_md_mempools; 49struct dm_target_io; 50struct dm_io; 51 52/* 53 *--------------------------------------------------------------- 54 * Internal table functions. 55 *--------------------------------------------------------------- 56 */ 57void dm_table_event_callback(struct dm_table *t, 58 void (*fn)(void *), void *context); 59struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector); 60bool dm_table_has_no_data_devices(struct dm_table *table); 61int dm_calculate_queue_limits(struct dm_table *table, 62 struct queue_limits *limits); 63int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 64 struct queue_limits *limits); 65struct list_head *dm_table_get_devices(struct dm_table *t); 66void dm_table_presuspend_targets(struct dm_table *t); 67void dm_table_presuspend_undo_targets(struct dm_table *t); 68void dm_table_postsuspend_targets(struct dm_table *t); 69int dm_table_resume_targets(struct dm_table *t); 70enum dm_queue_mode dm_table_get_type(struct dm_table *t); 71struct target_type *dm_table_get_immutable_target_type(struct dm_table *t); 72struct dm_target *dm_table_get_immutable_target(struct dm_table *t); 73struct dm_target *dm_table_get_wildcard_target(struct dm_table *t); 74bool dm_table_bio_based(struct dm_table *t); 75bool dm_table_request_based(struct dm_table *t); 76 77void dm_lock_md_type(struct mapped_device *md); 78void dm_unlock_md_type(struct mapped_device *md); 79void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type); 80enum dm_queue_mode dm_get_md_type(struct mapped_device *md); 81struct target_type *dm_get_immutable_target_type(struct mapped_device *md); 82 83int 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 */ 104int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q); 105void dm_zone_endio(struct dm_io *io, struct bio *clone); 106#ifdef CONFIG_BLK_DEV_ZONED 107void dm_cleanup_zoned_dev(struct mapped_device *md); 108int dm_blk_report_zones(struct gendisk *disk, sector_t sector, 109 unsigned int nr_zones, report_zones_cb cb, void *data); 110bool dm_is_zone_write(struct mapped_device *md, struct bio *bio); 111int dm_zone_map_bio(struct dm_target_io *io); 112#else 113static inline void dm_cleanup_zoned_dev(struct mapped_device *md) {} 114#define dm_blk_report_zones NULL 115static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio) 116{ 117 return false; 118} 119static 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 */ 130int dm_target_init(void); 131void dm_target_exit(void); 132struct target_type *dm_get_target_type(const char *name); 133void dm_put_target_type(struct target_type *tt); 134int dm_target_iterate(void (*iter_func)(struct target_type *tt, 135 void *param), void *param); 136 137int dm_split_args(int *argc, char ***argvp, char *input); 138 139/* 140 * Is this mapped_device being deleted? 141 */ 142int dm_deleting_md(struct mapped_device *md); 143 144/* 145 * Is this mapped_device suspended? 146 */ 147int dm_suspended_md(struct mapped_device *md); 148 149/* 150 * Internal suspend and resume methods. 151 */ 152int dm_suspended_internally_md(struct mapped_device *md); 153void dm_internal_suspend_fast(struct mapped_device *md); 154void dm_internal_resume_fast(struct mapped_device *md); 155void dm_internal_suspend_noflush(struct mapped_device *md); 156void dm_internal_resume(struct mapped_device *md); 157 158/* 159 * Test if the device is scheduled for deferred remove. 160 */ 161int dm_test_deferred_remove_flag(struct mapped_device *md); 162 163/* 164 * Try to remove devices marked for deferred removal. 165 */ 166void 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 */ 172int dm_interface_init(void); 173void dm_interface_exit(void); 174 175/* 176 * sysfs interface 177 */ 178int dm_sysfs_init(struct mapped_device *md); 179void dm_sysfs_exit(struct mapped_device *md); 180struct kobject *dm_kobject(struct mapped_device *md); 181struct mapped_device *dm_get_from_kobject(struct kobject *kobj); 182 183/* 184 * The kobject helper 185 */ 186void dm_kobject_release(struct kobject *kobj); 187 188/* 189 * Targets for linear and striped mappings 190 */ 191int linear_map(struct dm_target *ti, struct bio *bio); 192int dm_linear_init(void); 193void dm_linear_exit(void); 194 195int stripe_map(struct dm_target *ti, struct bio *bio); 196int dm_stripe_init(void); 197void dm_stripe_exit(void); 198 199/* 200 * mapped_device operations 201 */ 202void dm_destroy(struct mapped_device *md); 203void dm_destroy_immediate(struct mapped_device *md); 204int dm_open_count(struct mapped_device *md); 205int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); 206int dm_cancel_deferred_remove(struct mapped_device *md); 207int dm_request_based(struct mapped_device *md); 208int dm_get_table_device(struct mapped_device *md, dev_t dev, blk_mode_t mode, 209 struct dm_dev **result); 210void dm_put_table_device(struct mapped_device *md, struct dm_dev *d); 211 212int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, 213 unsigned int cookie, bool need_resize_uevent); 214 215int dm_io_init(void); 216void dm_io_exit(void); 217 218int dm_kcopyd_init(void); 219void dm_kcopyd_exit(void); 220 221/* 222 * Mempool operations 223 */ 224void dm_free_md_mempools(struct dm_md_mempools *pools); 225 226/* 227 * Various helpers 228 */ 229unsigned int dm_get_reserved_bio_based_ios(void); 230 231#define DM_HASH_LOCKS_MAX 64 232 233static inline unsigned int dm_num_hash_locks(void) 234{ 235 unsigned int num_locks = roundup_pow_of_two(num_online_cpus()) << 1; 236 237 return min_t(unsigned int, num_locks, DM_HASH_LOCKS_MAX); 238} 239 240#define DM_HASH_LOCKS_MULT 4294967291ULL 241#define DM_HASH_LOCKS_SHIFT 6 242 243static inline unsigned int dm_hash_locks_index(sector_t block, 244 unsigned int num_locks) 245{ 246 sector_t h1 = (block * DM_HASH_LOCKS_MULT) >> DM_HASH_LOCKS_SHIFT; 247 sector_t h2 = h1 >> DM_HASH_LOCKS_SHIFT; 248 249 return (h1 ^ h2) & (num_locks - 1); 250} 251 252#endif 253