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/blk-crypto-profile.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 struct mapped_device {
37 struct mutex suspend_lock;
38
39 struct mutex table_devices_lock;
40 struct list_head table_devices;
41
42 /*
43 * The current mapping (struct dm_table *).
44 * Use dm_get_live_table{_fast} or take suspend_lock for
45 * dereference.
46 */
47 void __rcu *map;
48
49 unsigned long flags;
50
51 /* Protect queue and type against concurrent access. */
52 struct mutex type_lock;
53 enum dm_queue_mode type;
54
55 int numa_node_id;
56 struct request_queue *queue;
57
58 atomic_t holders;
59 atomic_t open_count;
60
61 struct dm_target *immutable_target;
62 struct target_type *immutable_target_type;
63
64 char name[16];
65 struct gendisk *disk;
66 struct dax_device *dax_dev;
67
68 /*
69 * A list of ios that arrived while we were suspended.
70 */
71 struct work_struct work;
72 wait_queue_head_t wait;
73 spinlock_t deferred_lock;
74 struct bio_list deferred;
75
76 void *interface_ptr;
77
78 /*
79 * Event handling.
80 */
81 wait_queue_head_t eventq;
82 atomic_t event_nr;
83 atomic_t uevent_seq;
84 struct list_head uevent_list;
85 spinlock_t uevent_lock; /* Protect access to uevent_list */
86
87 /* the number of internal suspends */
88 unsigned internal_suspend_count;
89
90 /*
91 * io objects are allocated from here.
92 */
93 struct bio_set io_bs;
94 struct bio_set bs;
95
96 /*
97 * Processing queue (flush)
98 */
99 struct workqueue_struct *wq;
100
101 /* forced geometry settings */
102 struct hd_geometry geometry;
103
104 /* kobject and completion */
105 struct dm_kobject_holder kobj_holder;
106
107 int swap_bios;
108 struct semaphore swap_bios_semaphore;
109 struct mutex swap_bios_lock;
110
111 struct dm_stats stats;
112
113 /* for blk-mq request-based DM support */
114 struct blk_mq_tag_set *tag_set;
115 bool init_tio_pdu:1;
116
117 struct srcu_struct io_barrier;
118
119 #ifdef CONFIG_BLK_DEV_ZONED
120 unsigned int nr_zones;
121 unsigned int *zwp_offset;
122 #endif
123
124 #ifdef CONFIG_IMA
125 struct dm_ima_measurements ima;
126 #endif
127 };
128
129 /*
130 * Bits for the flags field of struct mapped_device.
131 */
132 #define DMF_BLOCK_IO_FOR_SUSPEND 0
133 #define DMF_SUSPENDED 1
134 #define DMF_FROZEN 2
135 #define DMF_FREEING 3
136 #define DMF_DELETING 4
137 #define DMF_NOFLUSH_SUSPENDING 5
138 #define DMF_DEFERRED_REMOVE 6
139 #define DMF_SUSPENDED_INTERNALLY 7
140 #define DMF_POST_SUSPENDING 8
141 #define DMF_EMULATE_ZONE_APPEND 9
142
143 void disable_discard(struct mapped_device *md);
144 void disable_write_same(struct mapped_device *md);
145 void disable_write_zeroes(struct mapped_device *md);
146
dm_get_size(struct mapped_device * md)147 static inline sector_t dm_get_size(struct mapped_device *md)
148 {
149 return get_capacity(md->disk);
150 }
151
dm_get_stats(struct mapped_device * md)152 static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
153 {
154 return &md->stats;
155 }
156
dm_emulate_zone_append(struct mapped_device * md)157 static inline bool dm_emulate_zone_append(struct mapped_device *md)
158 {
159 if (blk_queue_is_zoned(md->queue))
160 return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
161 return false;
162 }
163
164 #define DM_TABLE_MAX_DEPTH 16
165
166 struct dm_table {
167 struct mapped_device *md;
168 enum dm_queue_mode type;
169
170 /* btree table */
171 unsigned int depth;
172 unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
173 sector_t *index[DM_TABLE_MAX_DEPTH];
174
175 unsigned int num_targets;
176 unsigned int num_allocated;
177 sector_t *highs;
178 struct dm_target *targets;
179
180 struct target_type *immutable_target_type;
181
182 bool integrity_supported:1;
183 bool singleton:1;
184 unsigned integrity_added:1;
185
186 /*
187 * Indicates the rw permissions for the new logical
188 * device. This should be a combination of FMODE_READ
189 * and FMODE_WRITE.
190 */
191 fmode_t mode;
192
193 /* a list of devices used by this table */
194 struct list_head devices;
195
196 /* events get handed up using this callback */
197 void (*event_fn)(void *);
198 void *event_context;
199
200 struct dm_md_mempools *mempools;
201
202 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
203 struct blk_crypto_profile *crypto_profile;
204 #endif
205 };
206
207 /*
208 * One of these is allocated per clone bio.
209 */
210 #define DM_TIO_MAGIC 7282014
211 struct dm_target_io {
212 unsigned int magic;
213 struct dm_io *io;
214 struct dm_target *ti;
215 unsigned int target_bio_nr;
216 unsigned int *len_ptr;
217 bool inside_dm_io;
218 struct bio clone;
219 };
220
221 /*
222 * One of these is allocated per original bio.
223 * It contains the first clone used for that original.
224 */
225 #define DM_IO_MAGIC 5191977
226 struct dm_io {
227 unsigned int magic;
228 struct mapped_device *md;
229 blk_status_t status;
230 atomic_t io_count;
231 struct bio *orig_bio;
232 unsigned long start_time;
233 spinlock_t endio_lock;
234 struct dm_stats_aux stats_aux;
235 /* last member of dm_target_io is 'struct bio' */
236 struct dm_target_io tio;
237 };
238
dm_io_inc_pending(struct dm_io * io)239 static inline void dm_io_inc_pending(struct dm_io *io)
240 {
241 atomic_inc(&io->io_count);
242 }
243
244 void dm_io_dec_pending(struct dm_io *io, blk_status_t error);
245
dm_get_completion_from_kobject(struct kobject * kobj)246 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
247 {
248 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
249 }
250
251 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
252
dm_message_test_buffer_overflow(char * result,unsigned maxlen)253 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
254 {
255 return !maxlen || strlen(result) + 1 >= maxlen;
256 }
257
258 extern atomic_t dm_global_event_nr;
259 extern wait_queue_head_t dm_global_eventq;
260 void dm_issue_global_event(void);
261
262 #endif
263