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