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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Internal header file _only_ for device mapper core
4 *
5 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
6 *
7 * This file is released under the LGPL.
8 */
9
10#ifndef DM_CORE_INTERNAL_H
11#define DM_CORE_INTERNAL_H
12
13#include <linux/kthread.h>
14#include <linux/ktime.h>
15#include <linux/blk-mq.h>
16#include <linux/blk-crypto-profile.h>
17#include <linux/jump_label.h>
18
19#include <trace/events/block.h>
20
21#include "dm.h"
22#include "dm-ima.h"
23
24#define DM_RESERVED_MAX_IOS 1024
25#define DM_MAX_TARGETS 1048576
26#define DM_MAX_TARGET_PARAMS 1024
27
28struct dm_io;
29
30struct dm_kobject_holder {
31 struct kobject kobj;
32 struct completion completion;
33};
34
35/*
36 * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
37 * DM targets must _not_ deference a mapped_device or dm_table to directly
38 * access their members!
39 */
40
41/*
42 * For mempools pre-allocation at the table loading time.
43 */
44struct dm_md_mempools {
45 struct bio_set bs;
46 struct bio_set io_bs;
47};
48
49struct mapped_device {
50 struct mutex suspend_lock;
51
52 struct mutex table_devices_lock;
53 struct list_head table_devices;
54
55 /*
56 * The current mapping (struct dm_table *).
57 * Use dm_get_live_table{_fast} or take suspend_lock for
58 * dereference.
59 */
60 void __rcu *map;
61
62 unsigned long flags;
63
64 /* Protect queue and type against concurrent access. */
65 struct mutex type_lock;
66 enum dm_queue_mode type;
67
68 int numa_node_id;
69 struct request_queue *queue;
70
71 atomic_t holders;
72 atomic_t open_count;
73
74 struct dm_target *immutable_target;
75 struct target_type *immutable_target_type;
76
77 char name[16];
78 struct gendisk *disk;
79 struct dax_device *dax_dev;
80
81 wait_queue_head_t wait;
82 unsigned long __percpu *pending_io;
83
84 /* forced geometry settings */
85 struct hd_geometry geometry;
86
87 /*
88 * Processing queue (flush)
89 */
90 struct workqueue_struct *wq;
91
92 /*
93 * A list of ios that arrived while we were suspended.
94 */
95 struct work_struct work;
96 spinlock_t deferred_lock;
97 struct bio_list deferred;
98
99 /*
100 * requeue work context is needed for cloning one new bio
101 * to represent the dm_io to be requeued, since each
102 * dm_io may point to the original bio from FS.
103 */
104 struct work_struct requeue_work;
105 struct dm_io *requeue_list;
106
107 void *interface_ptr;
108
109 /*
110 * Event handling.
111 */
112 wait_queue_head_t eventq;
113 atomic_t event_nr;
114 atomic_t uevent_seq;
115 struct list_head uevent_list;
116 spinlock_t uevent_lock; /* Protect access to uevent_list */
117
118 /* for blk-mq request-based DM support */
119 bool init_tio_pdu:1;
120 struct blk_mq_tag_set *tag_set;
121
122 struct dm_stats stats;
123
124 /* the number of internal suspends */
125 unsigned int internal_suspend_count;
126
127 int swap_bios;
128 struct semaphore swap_bios_semaphore;
129 struct mutex swap_bios_lock;
130
131 /*
132 * io objects are allocated from here.
133 */
134 struct dm_md_mempools *mempools;
135
136 /* kobject and completion */
137 struct dm_kobject_holder kobj_holder;
138
139 struct srcu_struct io_barrier;
140
141#ifdef CONFIG_BLK_DEV_ZONED
142 void *zone_revalidate_map;
143 struct task_struct *revalidate_map_task;
144#endif
145
146#ifdef CONFIG_IMA
147 struct dm_ima_measurements ima;
148#endif
149};
150
151/*
152 * Bits for the flags field of struct mapped_device.
153 */
154#define DMF_BLOCK_IO_FOR_SUSPEND 0
155#define DMF_SUSPENDED 1
156#define DMF_FROZEN 2
157#define DMF_FREEING 3
158#define DMF_DELETING 4
159#define DMF_NOFLUSH_SUSPENDING 5
160#define DMF_DEFERRED_REMOVE 6
161#define DMF_SUSPENDED_INTERNALLY 7
162#define DMF_POST_SUSPENDING 8
163#define DMF_EMULATE_ZONE_APPEND 9
164#define DMF_QUEUE_STOPPED 10
165
166static inline sector_t dm_get_size(struct mapped_device *md)
167{
168 return get_capacity(disk: md->disk);
169}
170
171static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
172{
173 return &md->stats;
174}
175
176DECLARE_STATIC_KEY_FALSE(stats_enabled);
177DECLARE_STATIC_KEY_FALSE(swap_bios_enabled);
178DECLARE_STATIC_KEY_FALSE(zoned_enabled);
179
180static inline bool dm_emulate_zone_append(struct mapped_device *md)
181{
182 if (blk_queue_is_zoned(q: md->queue))
183 return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
184 return false;
185}
186
187#define DM_TABLE_MAX_DEPTH 16
188
189struct dm_table {
190 struct mapped_device *md;
191 enum dm_queue_mode type;
192
193 /* btree table */
194 unsigned int depth;
195 unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
196 sector_t *index[DM_TABLE_MAX_DEPTH];
197
198 unsigned int num_targets;
199 unsigned int num_allocated;
200 sector_t *highs;
201 struct dm_target *targets;
202
203 struct target_type *immutable_target_type;
204
205 bool integrity_supported:1;
206 bool singleton:1;
207 /* set if all the targets in the table have "flush_bypasses_map" set */
208 bool flush_bypasses_map:1;
209
210 /*
211 * Indicates the rw permissions for the new logical device. This
212 * should be a combination of BLK_OPEN_READ and BLK_OPEN_WRITE.
213 */
214 blk_mode_t mode;
215
216 /* a list of devices used by this table */
217 struct list_head devices;
218 struct rw_semaphore devices_lock;
219
220 /* events get handed up using this callback */
221 void (*event_fn)(void *data);
222 void *event_context;
223
224 struct dm_md_mempools *mempools;
225
226#ifdef CONFIG_BLK_INLINE_ENCRYPTION
227 struct blk_crypto_profile *crypto_profile;
228#endif
229};
230
231static inline struct dm_target *dm_table_get_target(struct dm_table *t,
232 unsigned int index)
233{
234 BUG_ON(index >= t->num_targets);
235 return t->targets + index;
236}
237
238/*
239 * One of these is allocated per clone bio.
240 */
241#define DM_TIO_MAGIC 28714
242struct dm_target_io {
243 unsigned short magic;
244 blk_short_t flags;
245 unsigned int target_bio_nr;
246 struct dm_io *io;
247 struct dm_target *ti;
248 unsigned int *len_ptr;
249 sector_t old_sector;
250 struct bio clone;
251};
252#define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
253#define DM_IO_BIO_OFFSET \
254 (offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
255
256/*
257 * dm_target_io flags
258 */
259enum {
260 DM_TIO_INSIDE_DM_IO,
261 DM_TIO_IS_DUPLICATE_BIO
262};
263
264static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)
265{
266 return (tio->flags & (1U << bit)) != 0;
267}
268
269static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)
270{
271 tio->flags |= (1U << bit);
272}
273
274static inline bool dm_tio_is_normal(struct dm_target_io *tio)
275{
276 return (dm_tio_flagged(tio, bit: DM_TIO_INSIDE_DM_IO) &&
277 !dm_tio_flagged(tio, bit: DM_TIO_IS_DUPLICATE_BIO));
278}
279
280/*
281 * One of these is allocated per original bio.
282 * It contains the first clone used for that original.
283 */
284#define DM_IO_MAGIC 19577
285struct dm_io {
286 unsigned short magic;
287 blk_short_t flags;
288 spinlock_t lock;
289 unsigned long start_time;
290 void *data;
291 struct dm_io *next;
292 struct dm_stats_aux stats_aux;
293 blk_status_t status;
294 bool requeue_flush_with_data;
295 atomic_t io_count;
296 struct mapped_device *md;
297
298 /* The three fields represent mapped part of original bio */
299 struct bio *orig_bio;
300 unsigned int sector_offset; /* offset to end of orig_bio */
301 unsigned int sectors;
302
303 /* last member of dm_target_io is 'struct bio' */
304 struct dm_target_io tio;
305};
306
307/*
308 * dm_io flags
309 */
310enum {
311 DM_IO_ACCOUNTED,
312 DM_IO_WAS_SPLIT,
313 DM_IO_BLK_STAT
314};
315
316static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)
317{
318 return (io->flags & (1U << bit)) != 0;
319}
320
321static inline void dm_io_set_flag(struct dm_io *io, unsigned int bit)
322{
323 io->flags |= (1U << bit);
324}
325
326void dm_io_rewind(struct dm_io *io, struct bio_set *bs);
327
328static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
329{
330 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
331}
332
333unsigned int __dm_get_module_param(unsigned int *module_param, unsigned int def, unsigned int max);
334
335static inline bool dm_message_test_buffer_overflow(char *result, unsigned int maxlen)
336{
337 return !maxlen || strlen(result) + 1 >= maxlen;
338}
339
340extern atomic_t dm_global_event_nr;
341extern wait_queue_head_t dm_global_eventq;
342void dm_issue_global_event(void);
343
344#endif
345

source code of linux/drivers/md/dm-core.h