2 * Internal header file _only_ for device mapper core
4 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
6 * This file is released under the LGPL.
9 #ifndef DM_CORE_INTERNAL_H
10 #define DM_CORE_INTERNAL_H
12 #include <linux/kthread.h>
13 #include <linux/ktime.h>
14 #include <linux/genhd.h>
15 #include <linux/blk-mq.h>
17 #include <trace/events/block.h>
21 #define DM_RESERVED_MAX_IOS 1024
22 #define DM_MAX_TARGETS 1048576
23 #define DM_MAX_TARGET_PARAMS 1024
25 struct dm_kobject_holder {
27 struct completion completion;
31 * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
32 * DM targets must _not_ deference a mapped_device or dm_table to directly
33 * access their members!
36 struct mapped_device {
37 struct mutex suspend_lock;
39 struct mutex table_devices_lock;
40 struct list_head table_devices;
43 * The current mapping (struct dm_table *).
44 * Use dm_get_live_table{_fast} or take suspend_lock for
51 /* Protect queue and type against concurrent access. */
52 struct mutex type_lock;
53 enum dm_queue_mode type;
56 struct request_queue *queue;
61 struct dm_target *immutable_target;
62 struct target_type *immutable_target_type;
66 struct dax_device *dax_dev;
69 * A list of ios that arrived while we were suspended.
71 struct work_struct work;
72 wait_queue_head_t wait;
73 spinlock_t deferred_lock;
74 struct bio_list deferred;
81 wait_queue_head_t eventq;
84 struct list_head uevent_list;
85 spinlock_t uevent_lock; /* Protect access to uevent_list */
87 /* the number of internal suspends */
88 unsigned internal_suspend_count;
91 * io objects are allocated from here.
97 * Processing queue (flush)
99 struct workqueue_struct *wq;
102 * freeze/thaw support require holding onto a super block
104 struct super_block *frozen_sb;
106 /* forced geometry settings */
107 struct hd_geometry geometry;
109 /* kobject and completion */
110 struct dm_kobject_holder kobj_holder;
112 struct block_device *bdev;
115 struct semaphore swap_bios_semaphore;
116 struct mutex swap_bios_lock;
118 struct dm_stats stats;
120 /* for blk-mq request-based DM support */
121 struct blk_mq_tag_set *tag_set;
124 struct srcu_struct io_barrier;
127 void disable_discard(struct mapped_device *md);
128 void disable_write_same(struct mapped_device *md);
129 void disable_write_zeroes(struct mapped_device *md);
131 static inline sector_t dm_get_size(struct mapped_device *md)
133 return get_capacity(md->disk);
136 static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
141 #define DM_TABLE_MAX_DEPTH 16
144 struct mapped_device *md;
145 enum dm_queue_mode type;
149 unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
150 sector_t *index[DM_TABLE_MAX_DEPTH];
152 unsigned int num_targets;
153 unsigned int num_allocated;
155 struct dm_target *targets;
157 struct target_type *immutable_target_type;
159 bool integrity_supported:1;
161 unsigned integrity_added:1;
164 * Indicates the rw permissions for the new logical
165 * device. This should be a combination of FMODE_READ
170 /* a list of devices used by this table */
171 struct list_head devices;
173 /* events get handed up using this callback */
174 void (*event_fn)(void *);
177 struct dm_md_mempools *mempools;
180 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
182 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
185 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
187 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
189 return !maxlen || strlen(result) + 1 >= maxlen;
192 extern atomic_t dm_global_event_nr;
193 extern wait_queue_head_t dm_global_eventq;
194 void dm_issue_global_event(void);