summaryrefslogtreecommitdiff
path: root/drivers/md/dm-core.h
blob: edc1553c4eeaee29fc239923fdefca73bf62a97b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
 * Internal header file _only_ for device mapper core
 *
 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the LGPL.
 */

#ifndef DM_CORE_INTERNAL_H
#define DM_CORE_INTERNAL_H

#include <linux/kthread.h>
#include <linux/ktime.h>
#include <linux/genhd.h>
#include <linux/blk-mq.h>
#include <linux/keyslot-manager.h>

#include <trace/events/block.h>

#include "dm.h"

#define DM_RESERVED_MAX_IOS		1024

struct dm_kobject_holder {
	struct kobject kobj;
	struct completion completion;
};

/*
 * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
 * DM targets must _not_ deference a mapped_device or dm_table to directly
 * access their members!
 */

struct mapped_device {
	struct mutex suspend_lock;

	struct mutex table_devices_lock;
	struct list_head table_devices;

	/*
	 * The current mapping (struct dm_table *).
	 * Use dm_get_live_table{_fast} or take suspend_lock for
	 * dereference.
	 */
	void __rcu *map;

	unsigned long flags;

	/* Protect queue and type against concurrent access. */
	struct mutex type_lock;
	enum dm_queue_mode type;

	int numa_node_id;
	struct request_queue *queue;

	atomic_t holders;
	atomic_t open_count;

	struct dm_target *immutable_target;
	struct target_type *immutable_target_type;

	char name[16];
	struct gendisk *disk;
	struct dax_device *dax_dev;

	/*
	 * A list of ios that arrived while we were suspended.
	 */
	struct work_struct work;
	wait_queue_head_t wait;
	spinlock_t deferred_lock;
	struct bio_list deferred;

	void *interface_ptr;

	/*
	 * Event handling.
	 */
	wait_queue_head_t eventq;
	atomic_t event_nr;
	atomic_t uevent_seq;
	struct list_head uevent_list;
	spinlock_t uevent_lock; /* Protect access to uevent_list */

	/* the number of internal suspends */
	unsigned internal_suspend_count;

	/*
	 * io objects are allocated from here.
	 */
	struct bio_set io_bs;
	struct bio_set bs;

	/*
	 * Processing queue (flush)
	 */
	struct workqueue_struct *wq;

	/* forced geometry settings */
	struct hd_geometry geometry;

	/* kobject and completion */
	struct dm_kobject_holder kobj_holder;

	int swap_bios;
	struct semaphore swap_bios_semaphore;
	struct mutex swap_bios_lock;

	struct dm_stats stats;

	/* for blk-mq request-based DM support */
	struct blk_mq_tag_set *tag_set;
	bool init_tio_pdu:1;

	struct srcu_struct io_barrier;

#ifdef CONFIG_BLK_DEV_ZONED
	unsigned int nr_zones;
	unsigned int *zwp_offset;
#endif
};

/*
 * Bits for the flags field of struct mapped_device.
 */
#define DMF_BLOCK_IO_FOR_SUSPEND 0
#define DMF_SUSPENDED 1
#define DMF_FROZEN 2
#define DMF_FREEING 3
#define DMF_DELETING 4
#define DMF_NOFLUSH_SUSPENDING 5
#define DMF_DEFERRED_REMOVE 6
#define DMF_SUSPENDED_INTERNALLY 7
#define DMF_POST_SUSPENDING 8
#define DMF_EMULATE_ZONE_APPEND 9

void disable_discard(struct mapped_device *md);
void disable_write_same(struct mapped_device *md);
void disable_write_zeroes(struct mapped_device *md);

static inline sector_t dm_get_size(struct mapped_device *md)
{
	return get_capacity(md->disk);
}

static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
{
	return &md->stats;
}

static inline bool dm_emulate_zone_append(struct mapped_device *md)
{
	if (blk_queue_is_zoned(md->queue))
		return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
	return false;
}

#define DM_TABLE_MAX_DEPTH 16

struct dm_table {
	struct mapped_device *md;
	enum dm_queue_mode type;

	/* btree table */
	unsigned int depth;
	unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
	sector_t *index[DM_TABLE_MAX_DEPTH];

	unsigned int num_targets;
	unsigned int num_allocated;
	sector_t *highs;
	struct dm_target *targets;

	struct target_type *immutable_target_type;

	bool integrity_supported:1;
	bool singleton:1;
	unsigned integrity_added:1;

	/*
	 * Indicates the rw permissions for the new logical
	 * device.  This should be a combination of FMODE_READ
	 * and FMODE_WRITE.
	 */
	fmode_t mode;

	/* a list of devices used by this table */
	struct list_head devices;

	/* events get handed up using this callback */
	void (*event_fn)(void *);
	void *event_context;

	struct dm_md_mempools *mempools;

#ifdef CONFIG_BLK_INLINE_ENCRYPTION
	struct blk_keyslot_manager *ksm;
#endif
};

/*
 * One of these is allocated per clone bio.
 */
#define DM_TIO_MAGIC 7282014
struct dm_target_io {
	unsigned int magic;
	struct dm_io *io;
	struct dm_target *ti;
	unsigned int target_bio_nr;
	unsigned int *len_ptr;
	bool inside_dm_io;
	struct bio clone;
};

/*
 * One of these is allocated per original bio.
 * It contains the first clone used for that original.
 */
#define DM_IO_MAGIC 5191977
struct dm_io {
	unsigned int magic;
	struct mapped_device *md;
	blk_status_t status;
	atomic_t io_count;
	struct bio *orig_bio;
	unsigned long start_time;
	spinlock_t endio_lock;
	struct dm_stats_aux stats_aux;
	/* last member of dm_target_io is 'struct bio' */
	struct dm_target_io tio;
};

static inline void dm_io_inc_pending(struct dm_io *io)
{
	atomic_inc(&io->io_count);
}

void dm_io_dec_pending(struct dm_io *io, blk_status_t error);

static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
{
	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
}

unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);

static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
{
	return !maxlen || strlen(result) + 1 >= maxlen;
}

extern atomic_t dm_global_event_nr;
extern wait_queue_head_t dm_global_eventq;
void dm_issue_global_event(void);

#endif