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