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/blk-mq.h>
15 #include <linux/blk-crypto-profile.h>
16 #include <linux/jump_label.h>
17 
18 #include <trace/events/block.h>
19 
20 #include "dm.h"
21 #include "dm-ima.h"
22 
23 #define DM_RESERVED_MAX_IOS		1024
24 
25 struct dm_kobject_holder {
26 	struct kobject kobj;
27 	struct completion completion;
28 };
29 
30 /*
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!
34  */
35 
36 /*
37  * For mempools pre-allocation at the table loading time.
38  */
39 struct dm_md_mempools {
40 	struct bio_set bs;
41 	struct bio_set io_bs;
42 };
43 
44 struct mapped_device {
45 	struct mutex suspend_lock;
46 
47 	struct mutex table_devices_lock;
48 	struct list_head table_devices;
49 
50 	/*
51 	 * The current mapping (struct dm_table *).
52 	 * Use dm_get_live_table{_fast} or take suspend_lock for
53 	 * dereference.
54 	 */
55 	void __rcu *map;
56 
57 	unsigned long flags;
58 
59 	/* Protect queue and type against concurrent access. */
60 	struct mutex type_lock;
61 	enum dm_queue_mode type;
62 
63 	int numa_node_id;
64 	struct request_queue *queue;
65 
66 	atomic_t holders;
67 	atomic_t open_count;
68 
69 	struct dm_target *immutable_target;
70 	struct target_type *immutable_target_type;
71 
72 	char name[16];
73 	struct gendisk *disk;
74 	struct dax_device *dax_dev;
75 
76 	wait_queue_head_t wait;
77 	unsigned long __percpu *pending_io;
78 
79 	/* forced geometry settings */
80 	struct hd_geometry geometry;
81 
82 	/*
83 	 * Processing queue (flush)
84 	 */
85 	struct workqueue_struct *wq;
86 
87 	/*
88 	 * A list of ios that arrived while we were suspended.
89 	 */
90 	struct work_struct work;
91 	spinlock_t deferred_lock;
92 	struct bio_list deferred;
93 
94 	void *interface_ptr;
95 
96 	/*
97 	 * Event handling.
98 	 */
99 	wait_queue_head_t eventq;
100 	atomic_t event_nr;
101 	atomic_t uevent_seq;
102 	struct list_head uevent_list;
103 	spinlock_t uevent_lock; /* Protect access to uevent_list */
104 
105 	/* for blk-mq request-based DM support */
106 	bool init_tio_pdu:1;
107 	struct blk_mq_tag_set *tag_set;
108 
109 	struct dm_stats stats;
110 
111 	/* the number of internal suspends */
112 	unsigned internal_suspend_count;
113 
114 	int swap_bios;
115 	struct semaphore swap_bios_semaphore;
116 	struct mutex swap_bios_lock;
117 
118 	/*
119 	 * io objects are allocated from here.
120 	 */
121 	struct dm_md_mempools *mempools;
122 
123 	/* kobject and completion */
124 	struct dm_kobject_holder kobj_holder;
125 
126 	struct srcu_struct io_barrier;
127 
128 #ifdef CONFIG_BLK_DEV_ZONED
129 	unsigned int nr_zones;
130 	unsigned int *zwp_offset;
131 #endif
132 
133 #ifdef CONFIG_IMA
134 	struct dm_ima_measurements ima;
135 #endif
136 };
137 
138 /*
139  * Bits for the flags field of struct mapped_device.
140  */
141 #define DMF_BLOCK_IO_FOR_SUSPEND 0
142 #define DMF_SUSPENDED 1
143 #define DMF_FROZEN 2
144 #define DMF_FREEING 3
145 #define DMF_DELETING 4
146 #define DMF_NOFLUSH_SUSPENDING 5
147 #define DMF_DEFERRED_REMOVE 6
148 #define DMF_SUSPENDED_INTERNALLY 7
149 #define DMF_POST_SUSPENDING 8
150 #define DMF_EMULATE_ZONE_APPEND 9
151 
152 void disable_discard(struct mapped_device *md);
153 void disable_write_zeroes(struct mapped_device *md);
154 
dm_get_size(struct mapped_device * md)155 static inline sector_t dm_get_size(struct mapped_device *md)
156 {
157 	return get_capacity(md->disk);
158 }
159 
dm_get_stats(struct mapped_device * md)160 static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
161 {
162 	return &md->stats;
163 }
164 
165 DECLARE_STATIC_KEY_FALSE(stats_enabled);
166 DECLARE_STATIC_KEY_FALSE(swap_bios_enabled);
167 DECLARE_STATIC_KEY_FALSE(zoned_enabled);
168 
dm_emulate_zone_append(struct mapped_device * md)169 static inline bool dm_emulate_zone_append(struct mapped_device *md)
170 {
171 	if (blk_queue_is_zoned(md->queue))
172 		return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
173 	return false;
174 }
175 
176 #define DM_TABLE_MAX_DEPTH 16
177 
178 struct dm_table {
179 	struct mapped_device *md;
180 	enum dm_queue_mode type;
181 
182 	/* btree table */
183 	unsigned int depth;
184 	unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
185 	sector_t *index[DM_TABLE_MAX_DEPTH];
186 
187 	unsigned int num_targets;
188 	unsigned int num_allocated;
189 	sector_t *highs;
190 	struct dm_target *targets;
191 
192 	struct target_type *immutable_target_type;
193 
194 	bool integrity_supported:1;
195 	bool singleton:1;
196 	unsigned integrity_added:1;
197 
198 	/*
199 	 * Indicates the rw permissions for the new logical
200 	 * device.  This should be a combination of FMODE_READ
201 	 * and FMODE_WRITE.
202 	 */
203 	fmode_t mode;
204 
205 	/* a list of devices used by this table */
206 	struct list_head devices;
207 
208 	/* events get handed up using this callback */
209 	void (*event_fn)(void *);
210 	void *event_context;
211 
212 	struct dm_md_mempools *mempools;
213 
214 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
215 	struct blk_crypto_profile *crypto_profile;
216 #endif
217 };
218 
219 /*
220  * One of these is allocated per clone bio.
221  */
222 #define DM_TIO_MAGIC 28714
223 struct dm_target_io {
224 	unsigned short magic;
225 	blk_short_t flags;
226 	unsigned int target_bio_nr;
227 	struct dm_io *io;
228 	struct dm_target *ti;
229 	unsigned int *len_ptr;
230 	sector_t old_sector;
231 	struct bio clone;
232 };
233 
234 /*
235  * dm_target_io flags
236  */
237 enum {
238 	DM_TIO_INSIDE_DM_IO,
239 	DM_TIO_IS_DUPLICATE_BIO
240 };
241 
dm_tio_flagged(struct dm_target_io * tio,unsigned int bit)242 static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)
243 {
244 	return (tio->flags & (1U << bit)) != 0;
245 }
246 
dm_tio_set_flag(struct dm_target_io * tio,unsigned int bit)247 static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)
248 {
249 	tio->flags |= (1U << bit);
250 }
251 
dm_tio_is_normal(struct dm_target_io * tio)252 static inline bool dm_tio_is_normal(struct dm_target_io *tio)
253 {
254 	return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&
255 		!dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
256 }
257 
258 /*
259  * One of these is allocated per original bio.
260  * It contains the first clone used for that original.
261  */
262 #define DM_IO_MAGIC 19577
263 struct dm_io {
264 	unsigned short magic;
265 	blk_short_t flags;
266 	spinlock_t lock;
267 	unsigned long start_time;
268 	void *data;
269 	struct dm_io *next;
270 	struct dm_stats_aux stats_aux;
271 	blk_status_t status;
272 	atomic_t io_count;
273 	struct mapped_device *md;
274 
275 	struct bio *split_bio;
276 	/* The three fields represent mapped part of original bio */
277 	struct bio *orig_bio;
278 	unsigned int sector_offset; /* offset to end of orig_bio */
279 	unsigned int sectors;
280 
281 	/* last member of dm_target_io is 'struct bio' */
282 	struct dm_target_io tio;
283 };
284 
285 /*
286  * dm_io flags
287  */
288 enum {
289 	DM_IO_ACCOUNTED,
290 	DM_IO_WAS_SPLIT
291 };
292 
dm_io_flagged(struct dm_io * io,unsigned int bit)293 static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)
294 {
295 	return (io->flags & (1U << bit)) != 0;
296 }
297 
dm_io_set_flag(struct dm_io * io,unsigned int bit)298 static inline void dm_io_set_flag(struct dm_io *io, unsigned int bit)
299 {
300 	io->flags |= (1U << bit);
301 }
302 
dm_get_completion_from_kobject(struct kobject * kobj)303 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
304 {
305 	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
306 }
307 
308 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
309 
dm_message_test_buffer_overflow(char * result,unsigned maxlen)310 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
311 {
312 	return !maxlen || strlen(result) + 1 >= maxlen;
313 }
314 
315 extern atomic_t dm_global_event_nr;
316 extern wait_queue_head_t dm_global_eventq;
317 void dm_issue_global_event(void);
318 
319 #endif
320