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	unsigned int nr_zones;
143	void *zone_revalidate_map;
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
165void disable_discard(struct mapped_device *md);
166void disable_write_zeroes(struct mapped_device *md);
167
168static inline sector_t dm_get_size(struct mapped_device *md)
169{
170	return get_capacity(md->disk);
171}
172
173static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
174{
175	return &md->stats;
176}
177
178DECLARE_STATIC_KEY_FALSE(stats_enabled);
179DECLARE_STATIC_KEY_FALSE(swap_bios_enabled);
180DECLARE_STATIC_KEY_FALSE(zoned_enabled);
181
182static inline bool dm_emulate_zone_append(struct mapped_device *md)
183{
184	if (blk_queue_is_zoned(md->queue))
185		return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
186	return false;
187}
188
189#define DM_TABLE_MAX_DEPTH 16
190
191struct dm_table {
192	struct mapped_device *md;
193	enum dm_queue_mode type;
194
195	/* btree table */
196	unsigned int depth;
197	unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
198	sector_t *index[DM_TABLE_MAX_DEPTH];
199
200	unsigned int num_targets;
201	unsigned int num_allocated;
202	sector_t *highs;
203	struct dm_target *targets;
204
205	struct target_type *immutable_target_type;
206
207	bool integrity_supported:1;
208	bool singleton:1;
209	/* set if all the targets in the table have "flush_bypasses_map" set */
210	bool flush_bypasses_map:1;
211
212	/*
213	 * Indicates the rw permissions for the new logical device.  This
214	 * should be a combination of BLK_OPEN_READ and BLK_OPEN_WRITE.
215	 */
216	blk_mode_t mode;
217
218	/* a list of devices used by this table */
219	struct list_head devices;
220	struct rw_semaphore devices_lock;
221
222	/* events get handed up using this callback */
223	void (*event_fn)(void *data);
224	void *event_context;
225
226	struct dm_md_mempools *mempools;
227
228#ifdef CONFIG_BLK_INLINE_ENCRYPTION
229	struct blk_crypto_profile *crypto_profile;
230#endif
231};
232
233static inline struct dm_target *dm_table_get_target(struct dm_table *t,
234						    unsigned int index)
235{
236	BUG_ON(index >= t->num_targets);
237	return t->targets + index;
238}
239
240/*
241 * One of these is allocated per clone bio.
242 */
243#define DM_TIO_MAGIC 28714
244struct dm_target_io {
245	unsigned short magic;
246	blk_short_t flags;
247	unsigned int target_bio_nr;
248	struct dm_io *io;
249	struct dm_target *ti;
250	unsigned int *len_ptr;
251	sector_t old_sector;
252	struct bio clone;
253};
254#define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
255#define DM_IO_BIO_OFFSET \
256	(offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
257
258/*
259 * dm_target_io flags
260 */
261enum {
262	DM_TIO_INSIDE_DM_IO,
263	DM_TIO_IS_DUPLICATE_BIO
264};
265
266static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)
267{
268	return (tio->flags & (1U << bit)) != 0;
269}
270
271static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)
272{
273	tio->flags |= (1U << bit);
274}
275
276static inline bool dm_tio_is_normal(struct dm_target_io *tio)
277{
278	return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&
279		!dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
280}
281
282/*
283 * One of these is allocated per original bio.
284 * It contains the first clone used for that original.
285 */
286#define DM_IO_MAGIC 19577
287struct dm_io {
288	unsigned short magic;
289	blk_short_t flags;
290	spinlock_t lock;
291	unsigned long start_time;
292	void *data;
293	struct dm_io *next;
294	struct dm_stats_aux stats_aux;
295	blk_status_t status;
296	atomic_t io_count;
297	struct mapped_device *md;
298
299	/* The three fields represent mapped part of original bio */
300	struct bio *orig_bio;
301	unsigned int sector_offset; /* offset to end of orig_bio */
302	unsigned int sectors;
303
304	/* last member of dm_target_io is 'struct bio' */
305	struct dm_target_io tio;
306};
307
308/*
309 * dm_io flags
310 */
311enum {
312	DM_IO_ACCOUNTED,
313	DM_IO_WAS_SPLIT,
314	DM_IO_BLK_STAT
315};
316
317static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)
318{
319	return (io->flags & (1U << bit)) != 0;
320}
321
322static inline void dm_io_set_flag(struct dm_io *io, unsigned int bit)
323{
324	io->flags |= (1U << bit);
325}
326
327void dm_io_rewind(struct dm_io *io, struct bio_set *bs);
328
329static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
330{
331	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
332}
333
334unsigned int __dm_get_module_param(unsigned int *module_param, unsigned int def, unsigned int max);
335
336static inline bool dm_message_test_buffer_overflow(char *result, unsigned int maxlen)
337{
338	return !maxlen || strlen(result) + 1 >= maxlen;
339}
340
341extern atomic_t dm_global_event_nr;
342extern wait_queue_head_t dm_global_eventq;
343void dm_issue_global_event(void);
344
345#endif