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/blkdev.h> 17 #include <linux/backing-dev.h> 18 #include <linux/hdreg.h> 19 #include <linux/completion.h> 20 #include <linux/kobject.h> 21 22 #include "dm-stats.h" 23 24 /* 25 * Suspend feature flags 26 */ 27 #define DM_SUSPEND_LOCKFS_FLAG (1 << 0) 28 #define DM_SUSPEND_NOFLUSH_FLAG (1 << 1) 29 30 /* 31 * Status feature flags 32 */ 33 #define DM_STATUS_NOFLUSH_FLAG (1 << 0) 34 35 /* 36 * Type of table and mapped_device's mempool 37 */ 38 #define DM_TYPE_NONE 0 39 #define DM_TYPE_BIO_BASED 1 40 #define DM_TYPE_REQUEST_BASED 2 41 #define DM_TYPE_MQ_REQUEST_BASED 3 42 43 /* 44 * List of devices that a metadevice uses and should open/close. 45 */ 46 struct dm_dev_internal { 47 struct list_head list; 48 atomic_t count; 49 struct dm_dev *dm_dev; 50 }; 51 52 struct dm_table; 53 struct dm_md_mempools; 54 55 /*----------------------------------------------------------------- 56 * Internal table functions. 57 *---------------------------------------------------------------*/ 58 void dm_table_destroy(struct dm_table *t); 59 void dm_table_event_callback(struct dm_table *t, 60 void (*fn)(void *), void *context); 61 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index); 62 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector); 63 bool dm_table_has_no_data_devices(struct dm_table *table); 64 int dm_calculate_queue_limits(struct dm_table *table, 65 struct queue_limits *limits); 66 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 67 struct queue_limits *limits); 68 struct list_head *dm_table_get_devices(struct dm_table *t); 69 void dm_table_presuspend_targets(struct dm_table *t); 70 void dm_table_presuspend_undo_targets(struct dm_table *t); 71 void dm_table_postsuspend_targets(struct dm_table *t); 72 int dm_table_resume_targets(struct dm_table *t); 73 int dm_table_any_congested(struct dm_table *t, int bdi_bits); 74 unsigned dm_table_get_type(struct dm_table *t); 75 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t); 76 bool dm_table_request_based(struct dm_table *t); 77 bool dm_table_mq_request_based(struct dm_table *t); 78 void dm_table_free_md_mempools(struct dm_table *t); 79 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); 80 81 void dm_lock_md_type(struct mapped_device *md); 82 void dm_unlock_md_type(struct mapped_device *md); 83 void dm_set_md_type(struct mapped_device *md, unsigned type); 84 unsigned dm_get_md_type(struct mapped_device *md); 85 struct target_type *dm_get_immutable_target_type(struct mapped_device *md); 86 87 int dm_setup_md_queue(struct mapped_device *md); 88 89 /* 90 * To check the return value from dm_table_find_target(). 91 */ 92 #define dm_target_is_valid(t) ((t)->table) 93 94 /* 95 * To check whether the target type is bio-based or not (request-based). 96 */ 97 #define dm_target_bio_based(t) ((t)->type->map != NULL) 98 99 /* 100 * To check whether the target type is request-based or not (bio-based). 101 */ 102 #define dm_target_request_based(t) (((t)->type->map_rq != NULL) || \ 103 ((t)->type->clone_and_map_rq != NULL)) 104 105 /* 106 * To check whether the target type is a hybrid (capable of being 107 * either request-based or bio-based). 108 */ 109 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t)) 110 111 /*----------------------------------------------------------------- 112 * A registry of target types. 113 *---------------------------------------------------------------*/ 114 int dm_target_init(void); 115 void dm_target_exit(void); 116 struct target_type *dm_get_target_type(const char *name); 117 void dm_put_target_type(struct target_type *tt); 118 int dm_target_iterate(void (*iter_func)(struct target_type *tt, 119 void *param), void *param); 120 121 int dm_split_args(int *argc, char ***argvp, char *input); 122 123 /* 124 * Is this mapped_device being deleted? 125 */ 126 int dm_deleting_md(struct mapped_device *md); 127 128 /* 129 * Is this mapped_device suspended? 130 */ 131 int dm_suspended_md(struct mapped_device *md); 132 133 /* 134 * Internal suspend and resume methods. 135 */ 136 int dm_suspended_internally_md(struct mapped_device *md); 137 void dm_internal_suspend_fast(struct mapped_device *md); 138 void dm_internal_resume_fast(struct mapped_device *md); 139 void dm_internal_suspend_noflush(struct mapped_device *md); 140 void dm_internal_resume(struct mapped_device *md); 141 142 /* 143 * Test if the device is scheduled for deferred remove. 144 */ 145 int dm_test_deferred_remove_flag(struct mapped_device *md); 146 147 /* 148 * Try to remove devices marked for deferred removal. 149 */ 150 void dm_deferred_remove(void); 151 152 /* 153 * The device-mapper can be driven through one of two interfaces; 154 * ioctl or filesystem, depending which patch you have applied. 155 */ 156 int dm_interface_init(void); 157 void dm_interface_exit(void); 158 159 /* 160 * sysfs interface 161 */ 162 struct dm_kobject_holder { 163 struct kobject kobj; 164 struct completion completion; 165 }; 166 167 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) 168 { 169 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; 170 } 171 172 int dm_sysfs_init(struct mapped_device *md); 173 void dm_sysfs_exit(struct mapped_device *md); 174 struct kobject *dm_kobject(struct mapped_device *md); 175 struct mapped_device *dm_get_from_kobject(struct kobject *kobj); 176 177 /* 178 * The kobject helper 179 */ 180 void dm_kobject_release(struct kobject *kobj); 181 182 /* 183 * Targets for linear and striped mappings 184 */ 185 int dm_linear_init(void); 186 void dm_linear_exit(void); 187 188 int dm_stripe_init(void); 189 void dm_stripe_exit(void); 190 191 /* 192 * mapped_device operations 193 */ 194 void dm_destroy(struct mapped_device *md); 195 void dm_destroy_immediate(struct mapped_device *md); 196 int dm_open_count(struct mapped_device *md); 197 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); 198 int dm_cancel_deferred_remove(struct mapped_device *md); 199 int dm_request_based(struct mapped_device *md); 200 sector_t dm_get_size(struct mapped_device *md); 201 struct request_queue *dm_get_md_queue(struct mapped_device *md); 202 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, 203 struct dm_dev **result); 204 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d); 205 struct dm_stats *dm_get_stats(struct mapped_device *md); 206 207 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, 208 unsigned cookie); 209 210 void dm_internal_suspend(struct mapped_device *md); 211 void dm_internal_resume(struct mapped_device *md); 212 213 bool dm_use_blk_mq(struct mapped_device *md); 214 215 int dm_io_init(void); 216 void dm_io_exit(void); 217 218 int dm_kcopyd_init(void); 219 void dm_kcopyd_exit(void); 220 221 /* 222 * Mempool operations 223 */ 224 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type, 225 unsigned integrity, unsigned per_bio_data_size); 226 void dm_free_md_mempools(struct dm_md_mempools *pools); 227 228 /* 229 * Helpers that are used by DM core 230 */ 231 unsigned dm_get_reserved_bio_based_ios(void); 232 unsigned dm_get_reserved_rq_based_ios(void); 233 234 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) 235 { 236 return !maxlen || strlen(result) + 1 >= maxlen; 237 } 238 239 ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf); 240 ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md, 241 const char *buf, size_t count); 242 243 #endif 244