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 17 #include <trace/events/block.h> 18 19 #include "dm.h" 20 21 #define DM_RESERVED_MAX_IOS 1024 22 23 struct dm_kobject_holder { 24 struct kobject kobj; 25 struct completion completion; 26 }; 27 28 /* 29 * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c. 30 * DM targets must _not_ deference a mapped_device or dm_table to directly 31 * access their members! 32 */ 33 34 struct mapped_device { 35 struct mutex suspend_lock; 36 37 struct mutex table_devices_lock; 38 struct list_head table_devices; 39 40 /* 41 * The current mapping (struct dm_table *). 42 * Use dm_get_live_table{_fast} or take suspend_lock for 43 * dereference. 44 */ 45 void __rcu *map; 46 47 unsigned long flags; 48 49 /* Protect queue and type against concurrent access. */ 50 struct mutex type_lock; 51 enum dm_queue_mode type; 52 53 int numa_node_id; 54 struct request_queue *queue; 55 56 atomic_t holders; 57 atomic_t open_count; 58 59 struct dm_target *immutable_target; 60 struct target_type *immutable_target_type; 61 62 char name[16]; 63 struct gendisk *disk; 64 struct dax_device *dax_dev; 65 66 /* 67 * A list of ios that arrived while we were suspended. 68 */ 69 struct work_struct work; 70 wait_queue_head_t wait; 71 spinlock_t deferred_lock; 72 struct bio_list deferred; 73 74 void *interface_ptr; 75 76 /* 77 * Event handling. 78 */ 79 wait_queue_head_t eventq; 80 atomic_t event_nr; 81 atomic_t uevent_seq; 82 struct list_head uevent_list; 83 spinlock_t uevent_lock; /* Protect access to uevent_list */ 84 85 /* the number of internal suspends */ 86 unsigned internal_suspend_count; 87 88 /* 89 * io objects are allocated from here. 90 */ 91 struct bio_set io_bs; 92 struct bio_set bs; 93 94 /* 95 * Processing queue (flush) 96 */ 97 struct workqueue_struct *wq; 98 99 /* 100 * freeze/thaw support require holding onto a super block 101 */ 102 struct super_block *frozen_sb; 103 104 /* forced geometry settings */ 105 struct hd_geometry geometry; 106 107 /* kobject and completion */ 108 struct dm_kobject_holder kobj_holder; 109 110 struct block_device *bdev; 111 112 struct dm_stats stats; 113 114 /* for blk-mq request-based DM support */ 115 struct blk_mq_tag_set *tag_set; 116 bool init_tio_pdu:1; 117 118 struct srcu_struct io_barrier; 119 }; 120 121 void disable_discard(struct mapped_device *md); 122 void disable_write_same(struct mapped_device *md); 123 void disable_write_zeroes(struct mapped_device *md); 124 125 static inline sector_t dm_get_size(struct mapped_device *md) 126 { 127 return get_capacity(md->disk); 128 } 129 130 static inline struct dm_stats *dm_get_stats(struct mapped_device *md) 131 { 132 return &md->stats; 133 } 134 135 #define DM_TABLE_MAX_DEPTH 16 136 137 struct dm_table { 138 struct mapped_device *md; 139 enum dm_queue_mode type; 140 141 /* btree table */ 142 unsigned int depth; 143 unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */ 144 sector_t *index[DM_TABLE_MAX_DEPTH]; 145 146 unsigned int num_targets; 147 unsigned int num_allocated; 148 sector_t *highs; 149 struct dm_target *targets; 150 151 struct target_type *immutable_target_type; 152 153 bool integrity_supported:1; 154 bool singleton:1; 155 unsigned integrity_added:1; 156 157 /* 158 * Indicates the rw permissions for the new logical 159 * device. This should be a combination of FMODE_READ 160 * and FMODE_WRITE. 161 */ 162 fmode_t mode; 163 164 /* a list of devices used by this table */ 165 struct list_head devices; 166 167 /* events get handed up using this callback */ 168 void (*event_fn)(void *); 169 void *event_context; 170 171 struct dm_md_mempools *mempools; 172 }; 173 174 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) 175 { 176 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; 177 } 178 179 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max); 180 181 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) 182 { 183 return !maxlen || strlen(result) + 1 >= maxlen; 184 } 185 186 extern atomic_t dm_global_event_nr; 187 extern wait_queue_head_t dm_global_eventq; 188 void dm_issue_global_event(void); 189 190 #endif 191