1 /* 2 * Internal header file _only_ for device mapper core 3 * 4 * Copyright (C) 2016 Red Hat, Inc. All rights reserved. 5 * 6 * This file is released under the LGPL. 7 */ 8 9 #ifndef DM_CORE_INTERNAL_H 10 #define DM_CORE_INTERNAL_H 11 12 #include <linux/kthread.h> 13 #include <linux/ktime.h> 14 #include <linux/genhd.h> 15 #include <linux/blk-mq.h> 16 #include <linux/keyslot-manager.h> 17 18 #include <trace/events/block.h> 19 20 #include "dm.h" 21 22 #define DM_RESERVED_MAX_IOS 1024 23 24 struct dm_kobject_holder { 25 struct kobject kobj; 26 struct completion completion; 27 }; 28 29 /* 30 * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c. 31 * DM targets must _not_ deference a mapped_device or dm_table to directly 32 * access their members! 33 */ 34 35 struct mapped_device { 36 struct mutex suspend_lock; 37 38 struct mutex table_devices_lock; 39 struct list_head table_devices; 40 41 /* 42 * The current mapping (struct dm_table *). 43 * Use dm_get_live_table{_fast} or take suspend_lock for 44 * dereference. 45 */ 46 void __rcu *map; 47 48 unsigned long flags; 49 50 /* Protect queue and type against concurrent access. */ 51 struct mutex type_lock; 52 enum dm_queue_mode type; 53 54 int numa_node_id; 55 struct request_queue *queue; 56 57 atomic_t holders; 58 atomic_t open_count; 59 60 struct dm_target *immutable_target; 61 struct target_type *immutable_target_type; 62 63 char name[16]; 64 struct gendisk *disk; 65 struct dax_device *dax_dev; 66 67 /* 68 * A list of ios that arrived while we were suspended. 69 */ 70 struct work_struct work; 71 wait_queue_head_t wait; 72 spinlock_t deferred_lock; 73 struct bio_list deferred; 74 75 void *interface_ptr; 76 77 /* 78 * Event handling. 79 */ 80 wait_queue_head_t eventq; 81 atomic_t event_nr; 82 atomic_t uevent_seq; 83 struct list_head uevent_list; 84 spinlock_t uevent_lock; /* Protect access to uevent_list */ 85 86 /* the number of internal suspends */ 87 unsigned internal_suspend_count; 88 89 /* 90 * io objects are allocated from here. 91 */ 92 struct bio_set io_bs; 93 struct bio_set bs; 94 95 /* 96 * Processing queue (flush) 97 */ 98 struct workqueue_struct *wq; 99 100 /* forced geometry settings */ 101 struct hd_geometry geometry; 102 103 /* kobject and completion */ 104 struct dm_kobject_holder kobj_holder; 105 106 int swap_bios; 107 struct semaphore swap_bios_semaphore; 108 struct mutex swap_bios_lock; 109 110 struct dm_stats stats; 111 112 /* for blk-mq request-based DM support */ 113 struct blk_mq_tag_set *tag_set; 114 bool init_tio_pdu:1; 115 116 struct srcu_struct io_barrier; 117 118 #ifdef CONFIG_BLK_DEV_ZONED 119 unsigned int nr_zones; 120 unsigned int *zwp_offset; 121 #endif 122 }; 123 124 /* 125 * Bits for the flags field of struct mapped_device. 126 */ 127 #define DMF_BLOCK_IO_FOR_SUSPEND 0 128 #define DMF_SUSPENDED 1 129 #define DMF_FROZEN 2 130 #define DMF_FREEING 3 131 #define DMF_DELETING 4 132 #define DMF_NOFLUSH_SUSPENDING 5 133 #define DMF_DEFERRED_REMOVE 6 134 #define DMF_SUSPENDED_INTERNALLY 7 135 #define DMF_POST_SUSPENDING 8 136 #define DMF_EMULATE_ZONE_APPEND 9 137 138 void disable_discard(struct mapped_device *md); 139 void disable_write_same(struct mapped_device *md); 140 void disable_write_zeroes(struct mapped_device *md); 141 142 static inline sector_t dm_get_size(struct mapped_device *md) 143 { 144 return get_capacity(md->disk); 145 } 146 147 static inline struct dm_stats *dm_get_stats(struct mapped_device *md) 148 { 149 return &md->stats; 150 } 151 152 static inline bool dm_emulate_zone_append(struct mapped_device *md) 153 { 154 if (blk_queue_is_zoned(md->queue)) 155 return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags); 156 return false; 157 } 158 159 #define DM_TABLE_MAX_DEPTH 16 160 161 struct dm_table { 162 struct mapped_device *md; 163 enum dm_queue_mode type; 164 165 /* btree table */ 166 unsigned int depth; 167 unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */ 168 sector_t *index[DM_TABLE_MAX_DEPTH]; 169 170 unsigned int num_targets; 171 unsigned int num_allocated; 172 sector_t *highs; 173 struct dm_target *targets; 174 175 struct target_type *immutable_target_type; 176 177 bool integrity_supported:1; 178 bool singleton:1; 179 unsigned integrity_added:1; 180 181 /* 182 * Indicates the rw permissions for the new logical 183 * device. This should be a combination of FMODE_READ 184 * and FMODE_WRITE. 185 */ 186 fmode_t mode; 187 188 /* a list of devices used by this table */ 189 struct list_head devices; 190 191 /* events get handed up using this callback */ 192 void (*event_fn)(void *); 193 void *event_context; 194 195 struct dm_md_mempools *mempools; 196 197 #ifdef CONFIG_BLK_INLINE_ENCRYPTION 198 struct blk_keyslot_manager *ksm; 199 #endif 200 }; 201 202 /* 203 * One of these is allocated per clone bio. 204 */ 205 #define DM_TIO_MAGIC 7282014 206 struct dm_target_io { 207 unsigned int magic; 208 struct dm_io *io; 209 struct dm_target *ti; 210 unsigned int target_bio_nr; 211 unsigned int *len_ptr; 212 bool inside_dm_io; 213 struct bio clone; 214 }; 215 216 /* 217 * One of these is allocated per original bio. 218 * It contains the first clone used for that original. 219 */ 220 #define DM_IO_MAGIC 5191977 221 struct dm_io { 222 unsigned int magic; 223 struct mapped_device *md; 224 blk_status_t status; 225 atomic_t io_count; 226 struct bio *orig_bio; 227 unsigned long start_time; 228 spinlock_t endio_lock; 229 struct dm_stats_aux stats_aux; 230 /* last member of dm_target_io is 'struct bio' */ 231 struct dm_target_io tio; 232 }; 233 234 static inline void dm_io_inc_pending(struct dm_io *io) 235 { 236 atomic_inc(&io->io_count); 237 } 238 239 void dm_io_dec_pending(struct dm_io *io, blk_status_t error); 240 241 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) 242 { 243 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; 244 } 245 246 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max); 247 248 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) 249 { 250 return !maxlen || strlen(result) + 1 >= maxlen; 251 } 252 253 extern atomic_t dm_global_event_nr; 254 extern wait_queue_head_t dm_global_eventq; 255 void dm_issue_global_event(void); 256 257 #endif 258