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#include <linux/keyslot-manager.h>
 17
 18#include <trace/events/block.h>
 19
 20#include "dm.h"
 21
 22#define DM_RESERVED_MAX_IOS		1024
 23
 24struct dm_kobject_holder {
 25	struct kobject kobj;
 26	struct completion completion;
 27};
 28
 29/*
 30 * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
 31 * DM targets must _not_ deference a mapped_device or dm_table to directly
 32 * access their members!
 33 */
 34
 35struct mapped_device {
 36	struct mutex suspend_lock;
 37
 38	struct mutex table_devices_lock;
 39	struct list_head table_devices;
 40
 41	/*
 42	 * The current mapping (struct dm_table *).
 43	 * Use dm_get_live_table{_fast} or take suspend_lock for
 44	 * dereference.
 45	 */
 46	void __rcu *map;
 47
 48	unsigned long flags;
 49
 50	/* Protect queue and type against concurrent access. */
 51	struct mutex type_lock;
 52	enum dm_queue_mode type;
 53
 54	int numa_node_id;
 55	struct request_queue *queue;
 56
 57	atomic_t holders;
 58	atomic_t open_count;
 59
 60	struct dm_target *immutable_target;
 61	struct target_type *immutable_target_type;
 62
 63	char name[16];
 64	struct gendisk *disk;
 65	struct dax_device *dax_dev;
 66
 67	/*
 68	 * A list of ios that arrived while we were suspended.
 69	 */
 70	struct work_struct work;
 71	wait_queue_head_t wait;
 72	spinlock_t deferred_lock;
 73	struct bio_list deferred;
 74
 75	void *interface_ptr;
 76
 77	/*
 78	 * Event handling.
 79	 */
 80	wait_queue_head_t eventq;
 81	atomic_t event_nr;
 82	atomic_t uevent_seq;
 83	struct list_head uevent_list;
 84	spinlock_t uevent_lock; /* Protect access to uevent_list */
 85
 86	/* the number of internal suspends */
 87	unsigned internal_suspend_count;
 88
 89	/*
 90	 * io objects are allocated from here.
 91	 */
 92	struct bio_set io_bs;
 93	struct bio_set bs;
 94
 95	/*
 96	 * Processing queue (flush)
 97	 */
 98	struct workqueue_struct *wq;
 99
100	/* forced geometry settings */
101	struct hd_geometry geometry;
102
103	/* kobject and completion */
104	struct dm_kobject_holder kobj_holder;
105
106	int swap_bios;
107	struct semaphore swap_bios_semaphore;
108	struct mutex swap_bios_lock;
109
110	struct dm_stats stats;
111
112	/* for blk-mq request-based DM support */
113	struct blk_mq_tag_set *tag_set;
114	bool init_tio_pdu:1;
115
116	struct srcu_struct io_barrier;
117
118#ifdef CONFIG_BLK_DEV_ZONED
119	unsigned int nr_zones;
120	unsigned int *zwp_offset;
121#endif
122};
123
124/*
125 * Bits for the flags field of struct mapped_device.
126 */
127#define DMF_BLOCK_IO_FOR_SUSPEND 0
128#define DMF_SUSPENDED 1
129#define DMF_FROZEN 2
130#define DMF_FREEING 3
131#define DMF_DELETING 4
132#define DMF_NOFLUSH_SUSPENDING 5
133#define DMF_DEFERRED_REMOVE 6
134#define DMF_SUSPENDED_INTERNALLY 7
135#define DMF_POST_SUSPENDING 8
136#define DMF_EMULATE_ZONE_APPEND 9
137
138void disable_discard(struct mapped_device *md);
139void disable_write_same(struct mapped_device *md);
140void disable_write_zeroes(struct mapped_device *md);
141
142static inline sector_t dm_get_size(struct mapped_device *md)
143{
144	return get_capacity(md->disk);
145}
146
147static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
148{
149	return &md->stats;
150}
151
152static inline bool dm_emulate_zone_append(struct mapped_device *md)
153{
154	if (blk_queue_is_zoned(md->queue))
155		return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
156	return false;
157}
158
159#define DM_TABLE_MAX_DEPTH 16
160
161struct dm_table {
162	struct mapped_device *md;
163	enum dm_queue_mode type;
164
165	/* btree table */
166	unsigned int depth;
167	unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
168	sector_t *index[DM_TABLE_MAX_DEPTH];
169
170	unsigned int num_targets;
171	unsigned int num_allocated;
172	sector_t *highs;
173	struct dm_target *targets;
174
175	struct target_type *immutable_target_type;
176
177	bool integrity_supported:1;
178	bool singleton:1;
179	unsigned integrity_added:1;
180
181	/*
182	 * Indicates the rw permissions for the new logical
183	 * device.  This should be a combination of FMODE_READ
184	 * and FMODE_WRITE.
185	 */
186	fmode_t mode;
187
188	/* a list of devices used by this table */
189	struct list_head devices;
190
191	/* events get handed up using this callback */
192	void (*event_fn)(void *);
193	void *event_context;
194
195	struct dm_md_mempools *mempools;
196
197#ifdef CONFIG_BLK_INLINE_ENCRYPTION
198	struct blk_keyslot_manager *ksm;
199#endif
200};
201
202/*
203 * One of these is allocated per clone bio.
204 */
205#define DM_TIO_MAGIC 7282014
206struct dm_target_io {
207	unsigned int magic;
208	struct dm_io *io;
209	struct dm_target *ti;
210	unsigned int target_bio_nr;
211	unsigned int *len_ptr;
212	bool inside_dm_io;
213	struct bio clone;
214};
215
216/*
217 * One of these is allocated per original bio.
218 * It contains the first clone used for that original.
219 */
220#define DM_IO_MAGIC 5191977
221struct dm_io {
222	unsigned int magic;
223	struct mapped_device *md;
224	blk_status_t status;
225	atomic_t io_count;
226	struct bio *orig_bio;
227	unsigned long start_time;
228	spinlock_t endio_lock;
229	struct dm_stats_aux stats_aux;
230	/* last member of dm_target_io is 'struct bio' */
231	struct dm_target_io tio;
232};
233
234static inline void dm_io_inc_pending(struct dm_io *io)
235{
236	atomic_inc(&io->io_count);
237}
238
239void dm_io_dec_pending(struct dm_io *io, blk_status_t error);
240
241static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
242{
243	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
244}
245
246unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
247
248static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
249{
250	return !maxlen || strlen(result) + 1 >= maxlen;
251}
252
253extern atomic_t dm_global_event_nr;
254extern wait_queue_head_t dm_global_eventq;
255void dm_issue_global_event(void);
256
257#endif