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/hdreg.h> 18 #include <linux/completion.h> 19 #include <linux/kobject.h> 20 21 #include "dm-stats.h" 22 23 /* 24 * Suspend feature flags 25 */ 26 #define DM_SUSPEND_LOCKFS_FLAG (1 << 0) 27 #define DM_SUSPEND_NOFLUSH_FLAG (1 << 1) 28 29 /* 30 * Status feature flags 31 */ 32 #define DM_STATUS_NOFLUSH_FLAG (1 << 0) 33 34 /* 35 * Type of table and mapped_device's mempool 36 */ 37 #define DM_TYPE_NONE 0 38 #define DM_TYPE_BIO_BASED 1 39 #define DM_TYPE_REQUEST_BASED 2 40 #define DM_TYPE_MQ_REQUEST_BASED 3 41 42 /* 43 * List of devices that a metadevice uses and should open/close. 44 */ 45 struct dm_dev_internal { 46 struct list_head list; 47 atomic_t count; 48 struct dm_dev *dm_dev; 49 }; 50 51 struct dm_table; 52 struct dm_md_mempools; 53 54 /*----------------------------------------------------------------- 55 * Internal table functions. 56 *---------------------------------------------------------------*/ 57 void dm_table_destroy(struct dm_table *t); 58 void dm_table_event_callback(struct dm_table *t, 59 void (*fn)(void *), void *context); 60 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index); 61 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector); 62 bool dm_table_has_no_data_devices(struct dm_table *table); 63 int dm_calculate_queue_limits(struct dm_table *table, 64 struct queue_limits *limits); 65 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 66 struct queue_limits *limits); 67 struct list_head *dm_table_get_devices(struct dm_table *t); 68 void dm_table_presuspend_targets(struct dm_table *t); 69 void dm_table_presuspend_undo_targets(struct dm_table *t); 70 void dm_table_postsuspend_targets(struct dm_table *t); 71 int dm_table_resume_targets(struct dm_table *t); 72 int dm_table_any_congested(struct dm_table *t, int bdi_bits); 73 unsigned dm_table_get_type(struct dm_table *t); 74 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t); 75 bool dm_table_request_based(struct dm_table *t); 76 bool dm_table_mq_request_based(struct dm_table *t); 77 void dm_table_free_md_mempools(struct dm_table *t); 78 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); 79 80 int dm_queue_merge_is_compulsory(struct request_queue *q); 81 82 void dm_lock_md_type(struct mapped_device *md); 83 void dm_unlock_md_type(struct mapped_device *md); 84 void dm_set_md_type(struct mapped_device *md, unsigned type); 85 unsigned dm_get_md_type(struct mapped_device *md); 86 struct target_type *dm_get_immutable_target_type(struct mapped_device *md); 87 88 int dm_setup_md_queue(struct mapped_device *md); 89 90 /* 91 * To check the return value from dm_table_find_target(). 92 */ 93 #define dm_target_is_valid(t) ((t)->table) 94 95 /* 96 * To check whether the target type is bio-based or not (request-based). 97 */ 98 #define dm_target_bio_based(t) ((t)->type->map != NULL) 99 100 /* 101 * To check whether the target type is request-based or not (bio-based). 102 */ 103 #define dm_target_request_based(t) (((t)->type->map_rq != NULL) || \ 104 ((t)->type->clone_and_map_rq != NULL)) 105 106 /* 107 * To check whether the target type is a hybrid (capable of being 108 * either request-based or bio-based). 109 */ 110 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t)) 111 112 /*----------------------------------------------------------------- 113 * A registry of target types. 114 *---------------------------------------------------------------*/ 115 int dm_target_init(void); 116 void dm_target_exit(void); 117 struct target_type *dm_get_target_type(const char *name); 118 void dm_put_target_type(struct target_type *tt); 119 int dm_target_iterate(void (*iter_func)(struct target_type *tt, 120 void *param), void *param); 121 122 int dm_split_args(int *argc, char ***argvp, char *input); 123 124 /* 125 * Is this mapped_device being deleted? 126 */ 127 int dm_deleting_md(struct mapped_device *md); 128 129 /* 130 * Is this mapped_device suspended? 131 */ 132 int dm_suspended_md(struct mapped_device *md); 133 134 /* 135 * Internal suspend and resume methods. 136 */ 137 int dm_suspended_internally_md(struct mapped_device *md); 138 void dm_internal_suspend_fast(struct mapped_device *md); 139 void dm_internal_resume_fast(struct mapped_device *md); 140 void dm_internal_suspend_noflush(struct mapped_device *md); 141 void dm_internal_resume(struct mapped_device *md); 142 143 /* 144 * Test if the device is scheduled for deferred remove. 145 */ 146 int dm_test_deferred_remove_flag(struct mapped_device *md); 147 148 /* 149 * Try to remove devices marked for deferred removal. 150 */ 151 void dm_deferred_remove(void); 152 153 /* 154 * The device-mapper can be driven through one of two interfaces; 155 * ioctl or filesystem, depending which patch you have applied. 156 */ 157 int dm_interface_init(void); 158 void dm_interface_exit(void); 159 160 /* 161 * sysfs interface 162 */ 163 struct dm_kobject_holder { 164 struct kobject kobj; 165 struct completion completion; 166 }; 167 168 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) 169 { 170 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; 171 } 172 173 int dm_sysfs_init(struct mapped_device *md); 174 void dm_sysfs_exit(struct mapped_device *md); 175 struct kobject *dm_kobject(struct mapped_device *md); 176 struct mapped_device *dm_get_from_kobject(struct kobject *kobj); 177 178 /* 179 * The kobject helper 180 */ 181 void dm_kobject_release(struct kobject *kobj); 182 183 /* 184 * Targets for linear and striped mappings 185 */ 186 int dm_linear_init(void); 187 void dm_linear_exit(void); 188 189 int dm_stripe_init(void); 190 void dm_stripe_exit(void); 191 192 /* 193 * mapped_device operations 194 */ 195 void dm_destroy(struct mapped_device *md); 196 void dm_destroy_immediate(struct mapped_device *md); 197 int dm_open_count(struct mapped_device *md); 198 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); 199 int dm_cancel_deferred_remove(struct mapped_device *md); 200 int dm_request_based(struct mapped_device *md); 201 sector_t dm_get_size(struct mapped_device *md); 202 struct request_queue *dm_get_md_queue(struct mapped_device *md); 203 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, 204 struct dm_dev **result); 205 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d); 206 struct dm_stats *dm_get_stats(struct mapped_device *md); 207 208 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, 209 unsigned cookie); 210 211 void dm_internal_suspend(struct mapped_device *md); 212 void dm_internal_resume(struct mapped_device *md); 213 214 bool dm_use_blk_mq(struct mapped_device *md); 215 216 int dm_io_init(void); 217 void dm_io_exit(void); 218 219 int dm_kcopyd_init(void); 220 void dm_kcopyd_exit(void); 221 222 /* 223 * Mempool operations 224 */ 225 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type, 226 unsigned integrity, unsigned per_bio_data_size); 227 void dm_free_md_mempools(struct dm_md_mempools *pools); 228 229 /* 230 * Helpers that are used by DM core 231 */ 232 unsigned dm_get_reserved_bio_based_ios(void); 233 unsigned dm_get_reserved_rq_based_ios(void); 234 235 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) 236 { 237 return !maxlen || strlen(result) + 1 >= maxlen; 238 } 239 240 ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf); 241 ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md, 242 const char *buf, size_t count); 243 244 #endif 245