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 bool dm_table_supports_discards(struct dm_table *t); 76 void dm_table_free_md_mempools(struct dm_table *t); 77 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); 78 79 int dm_queue_merge_is_compulsory(struct request_queue *q); 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) 103 104 /* 105 * To check whether the target type is a hybrid (capable of being 106 * either request-based or bio-based). 107 */ 108 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t)) 109 110 /*----------------------------------------------------------------- 111 * A registry of target types. 112 *---------------------------------------------------------------*/ 113 int dm_target_init(void); 114 void dm_target_exit(void); 115 struct target_type *dm_get_target_type(const char *name); 116 void dm_put_target_type(struct target_type *tt); 117 int dm_target_iterate(void (*iter_func)(struct target_type *tt, 118 void *param), void *param); 119 120 int dm_split_args(int *argc, char ***argvp, char *input); 121 122 /* 123 * Is this mapped_device being deleted? 124 */ 125 int dm_deleting_md(struct mapped_device *md); 126 127 /* 128 * Is this mapped_device suspended? 129 */ 130 int dm_suspended_md(struct mapped_device *md); 131 132 /* 133 * Test if the device is scheduled for deferred remove. 134 */ 135 int dm_test_deferred_remove_flag(struct mapped_device *md); 136 137 /* 138 * Try to remove devices marked for deferred removal. 139 */ 140 void dm_deferred_remove(void); 141 142 /* 143 * The device-mapper can be driven through one of two interfaces; 144 * ioctl or filesystem, depending which patch you have applied. 145 */ 146 int dm_interface_init(void); 147 void dm_interface_exit(void); 148 149 /* 150 * sysfs interface 151 */ 152 struct dm_kobject_holder { 153 struct kobject kobj; 154 struct completion completion; 155 }; 156 157 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) 158 { 159 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; 160 } 161 162 int dm_sysfs_init(struct mapped_device *md); 163 void dm_sysfs_exit(struct mapped_device *md); 164 struct kobject *dm_kobject(struct mapped_device *md); 165 struct mapped_device *dm_get_from_kobject(struct kobject *kobj); 166 167 /* 168 * The kobject helper 169 */ 170 void dm_kobject_release(struct kobject *kobj); 171 172 /* 173 * Targets for linear and striped mappings 174 */ 175 int dm_linear_init(void); 176 void dm_linear_exit(void); 177 178 int dm_stripe_init(void); 179 void dm_stripe_exit(void); 180 181 /* 182 * mapped_device operations 183 */ 184 void dm_destroy(struct mapped_device *md); 185 void dm_destroy_immediate(struct mapped_device *md); 186 int dm_open_count(struct mapped_device *md); 187 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); 188 int dm_cancel_deferred_remove(struct mapped_device *md); 189 int dm_request_based(struct mapped_device *md); 190 sector_t dm_get_size(struct mapped_device *md); 191 struct request_queue *dm_get_md_queue(struct mapped_device *md); 192 struct dm_stats *dm_get_stats(struct mapped_device *md); 193 194 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action, 195 unsigned cookie); 196 197 void dm_internal_suspend(struct mapped_device *md); 198 void dm_internal_resume(struct mapped_device *md); 199 200 int dm_io_init(void); 201 void dm_io_exit(void); 202 203 int dm_kcopyd_init(void); 204 void dm_kcopyd_exit(void); 205 206 /* 207 * Mempool operations 208 */ 209 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size); 210 void dm_free_md_mempools(struct dm_md_mempools *pools); 211 212 /* 213 * Helpers that are used by DM core 214 */ 215 unsigned dm_get_reserved_bio_based_ios(void); 216 unsigned dm_get_reserved_rq_based_ios(void); 217 218 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) 219 { 220 return !maxlen || strlen(result) + 1 >= maxlen; 221 } 222 223 #endif 224