xref: /openbmc/linux/drivers/md/dm-core.h (revision 438d1949)
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 
28 struct dm_io;
29 
30 struct 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  */
44 struct dm_md_mempools {
45 	struct bio_set bs;
46 	struct bio_set io_bs;
47 };
48 
49 struct 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 	unsigned int *zwp_offset;
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 
165 void disable_discard(struct mapped_device *md);
166 void disable_write_zeroes(struct mapped_device *md);
167 
dm_get_size(struct mapped_device * md)168 static inline sector_t dm_get_size(struct mapped_device *md)
169 {
170 	return get_capacity(md->disk);
171 }
172 
dm_get_stats(struct mapped_device * md)173 static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
174 {
175 	return &md->stats;
176 }
177 
178 DECLARE_STATIC_KEY_FALSE(stats_enabled);
179 DECLARE_STATIC_KEY_FALSE(swap_bios_enabled);
180 DECLARE_STATIC_KEY_FALSE(zoned_enabled);
181 
dm_emulate_zone_append(struct mapped_device * md)182 static 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 
191 struct 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 	unsigned integrity_added:1;
210 
211 	/*
212 	 * Indicates the rw permissions for the new logical device.  This
213 	 * should be a combination of BLK_OPEN_READ and BLK_OPEN_WRITE.
214 	 */
215 	blk_mode_t mode;
216 
217 	/* a list of devices used by this table */
218 	struct list_head devices;
219 	struct rw_semaphore devices_lock;
220 
221 	/* events get handed up using this callback */
222 	void (*event_fn)(void *data);
223 	void *event_context;
224 
225 	struct dm_md_mempools *mempools;
226 
227 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
228 	struct blk_crypto_profile *crypto_profile;
229 #endif
230 };
231 
dm_table_get_target(struct dm_table * t,unsigned int index)232 static inline struct dm_target *dm_table_get_target(struct dm_table *t,
233 						    unsigned int index)
234 {
235 	BUG_ON(index >= t->num_targets);
236 	return t->targets + index;
237 }
238 
239 /*
240  * One of these is allocated per clone bio.
241  */
242 #define DM_TIO_MAGIC 28714
243 struct dm_target_io {
244 	unsigned short magic;
245 	blk_short_t flags;
246 	unsigned int target_bio_nr;
247 	struct dm_io *io;
248 	struct dm_target *ti;
249 	unsigned int *len_ptr;
250 	sector_t old_sector;
251 	struct bio clone;
252 };
253 #define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
254 #define DM_IO_BIO_OFFSET \
255 	(offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
256 
257 /*
258  * dm_target_io flags
259  */
260 enum {
261 	DM_TIO_INSIDE_DM_IO,
262 	DM_TIO_IS_DUPLICATE_BIO
263 };
264 
dm_tio_flagged(struct dm_target_io * tio,unsigned int bit)265 static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)
266 {
267 	return (tio->flags & (1U << bit)) != 0;
268 }
269 
dm_tio_set_flag(struct dm_target_io * tio,unsigned int bit)270 static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)
271 {
272 	tio->flags |= (1U << bit);
273 }
274 
dm_tio_is_normal(struct dm_target_io * tio)275 static inline bool dm_tio_is_normal(struct dm_target_io *tio)
276 {
277 	return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&
278 		!dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
279 }
280 
281 /*
282  * One of these is allocated per original bio.
283  * It contains the first clone used for that original.
284  */
285 #define DM_IO_MAGIC 19577
286 struct dm_io {
287 	unsigned short magic;
288 	blk_short_t flags;
289 	spinlock_t lock;
290 	unsigned long start_time;
291 	void *data;
292 	struct dm_io *next;
293 	struct dm_stats_aux stats_aux;
294 	blk_status_t status;
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  */
310 enum {
311 	DM_IO_ACCOUNTED,
312 	DM_IO_WAS_SPLIT,
313 	DM_IO_BLK_STAT
314 };
315 
dm_io_flagged(struct dm_io * io,unsigned int bit)316 static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)
317 {
318 	return (io->flags & (1U << bit)) != 0;
319 }
320 
dm_io_set_flag(struct dm_io * io,unsigned int bit)321 static inline void dm_io_set_flag(struct dm_io *io, unsigned int bit)
322 {
323 	io->flags |= (1U << bit);
324 }
325 
326 void dm_io_rewind(struct dm_io *io, struct bio_set *bs);
327 
dm_get_completion_from_kobject(struct kobject * kobj)328 static 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 
333 unsigned int __dm_get_module_param(unsigned int *module_param, unsigned int def, unsigned int max);
334 
dm_message_test_buffer_overflow(char * result,unsigned int maxlen)335 static inline bool dm_message_test_buffer_overflow(char *result, unsigned int maxlen)
336 {
337 	return !maxlen || strlen(result) + 1 >= maxlen;
338 }
339 
340 extern atomic_t dm_global_event_nr;
341 extern wait_queue_head_t dm_global_eventq;
342 void dm_issue_global_event(void);
343 
344 #endif
345