1 /*
2 * Internal header file for device mapper
3 *
4 * Copyright (C) 2001, 2002 Sistina Software
5 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
6 *
7 * This file is released under the LGPL.
8 */
9
10 #ifndef DM_INTERNAL_H
11 #define DM_INTERNAL_H
12
13 #include <linux/fs.h>
14 #include <linux/device-mapper.h>
15 #include <linux/list.h>
16 #include <linux/moduleparam.h>
17 #include <linux/blkdev.h>
18 #include <linux/backing-dev.h>
19 #include <linux/hdreg.h>
20 #include <linux/completion.h>
21 #include <linux/kobject.h>
22 #include <linux/refcount.h>
23 #include <linux/log2.h>
24
25 #include "dm-stats.h"
26
27 /*
28 * Suspend feature flags
29 */
30 #define DM_SUSPEND_LOCKFS_FLAG (1 << 0)
31 #define DM_SUSPEND_NOFLUSH_FLAG (1 << 1)
32
33 /*
34 * Status feature flags
35 */
36 #define DM_STATUS_NOFLUSH_FLAG (1 << 0)
37
38 /*
39 * List of devices that a metadevice uses and should open/close.
40 */
41 struct dm_dev_internal {
42 struct list_head list;
43 refcount_t count;
44 struct dm_dev *dm_dev;
45 };
46
47 struct dm_table;
48 struct dm_md_mempools;
49 struct dm_target_io;
50 struct dm_io;
51
52 /*
53 *---------------------------------------------------------------
54 * Internal table functions.
55 *---------------------------------------------------------------
56 */
57 void dm_table_event_callback(struct dm_table *t,
58 void (*fn)(void *), void *context);
59 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
60 bool dm_table_has_no_data_devices(struct dm_table *table);
61 int dm_calculate_queue_limits(struct dm_table *table,
62 struct queue_limits *limits);
63 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
64 struct queue_limits *limits);
65 struct list_head *dm_table_get_devices(struct dm_table *t);
66 void dm_table_presuspend_targets(struct dm_table *t);
67 void dm_table_presuspend_undo_targets(struct dm_table *t);
68 void dm_table_postsuspend_targets(struct dm_table *t);
69 int dm_table_resume_targets(struct dm_table *t);
70 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
71 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
72 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
73 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
74 bool dm_table_bio_based(struct dm_table *t);
75 bool dm_table_request_based(struct dm_table *t);
76
77 void dm_lock_md_type(struct mapped_device *md);
78 void dm_unlock_md_type(struct mapped_device *md);
79 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
80 enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
81 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
82
83 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
84
85 /*
86 * To check whether the target type is bio-based or not (request-based).
87 */
88 #define dm_target_bio_based(t) ((t)->type->map != NULL)
89
90 /*
91 * To check whether the target type is request-based or not (bio-based).
92 */
93 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
94
95 /*
96 * To check whether the target type is a hybrid (capable of being
97 * either request-based or bio-based).
98 */
99 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
100
101 /*
102 * Zoned targets related functions.
103 */
104 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q);
105 void dm_zone_endio(struct dm_io *io, struct bio *clone);
106 #ifdef CONFIG_BLK_DEV_ZONED
107 void dm_cleanup_zoned_dev(struct mapped_device *md);
108 int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
109 unsigned int nr_zones, report_zones_cb cb, void *data);
110 bool dm_is_zone_write(struct mapped_device *md, struct bio *bio);
111 int dm_zone_map_bio(struct dm_target_io *io);
112 #else
dm_cleanup_zoned_dev(struct mapped_device * md)113 static inline void dm_cleanup_zoned_dev(struct mapped_device *md) {}
114 #define dm_blk_report_zones NULL
dm_is_zone_write(struct mapped_device * md,struct bio * bio)115 static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
116 {
117 return false;
118 }
dm_zone_map_bio(struct dm_target_io * tio)119 static inline int dm_zone_map_bio(struct dm_target_io *tio)
120 {
121 return DM_MAPIO_KILL;
122 }
123 #endif
124
125 /*
126 *---------------------------------------------------------------
127 * A registry of target types.
128 *---------------------------------------------------------------
129 */
130 int dm_target_init(void);
131 void dm_target_exit(void);
132 struct target_type *dm_get_target_type(const char *name);
133 void dm_put_target_type(struct target_type *tt);
134 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
135 void *param), void *param);
136
137 int dm_split_args(int *argc, char ***argvp, char *input);
138
139 /*
140 * Is this mapped_device being deleted?
141 */
142 int dm_deleting_md(struct mapped_device *md);
143
144 /*
145 * Is this mapped_device suspended?
146 */
147 int dm_suspended_md(struct mapped_device *md);
148
149 /*
150 * Internal suspend and resume methods.
151 */
152 int dm_suspended_internally_md(struct mapped_device *md);
153 void dm_internal_suspend_fast(struct mapped_device *md);
154 void dm_internal_resume_fast(struct mapped_device *md);
155 void dm_internal_suspend_noflush(struct mapped_device *md);
156 void dm_internal_resume(struct mapped_device *md);
157
158 /*
159 * Test if the device is scheduled for deferred remove.
160 */
161 int dm_test_deferred_remove_flag(struct mapped_device *md);
162
163 /*
164 * Try to remove devices marked for deferred removal.
165 */
166 void dm_deferred_remove(void);
167
168 /*
169 * The device-mapper can be driven through one of two interfaces;
170 * ioctl or filesystem, depending which patch you have applied.
171 */
172 int dm_interface_init(void);
173 void dm_interface_exit(void);
174
175 /*
176 * sysfs interface
177 */
178 int dm_sysfs_init(struct mapped_device *md);
179 void dm_sysfs_exit(struct mapped_device *md);
180 struct kobject *dm_kobject(struct mapped_device *md);
181 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
182
183 /*
184 * The kobject helper
185 */
186 void dm_kobject_release(struct kobject *kobj);
187
188 /*
189 * Targets for linear and striped mappings
190 */
191 int dm_linear_init(void);
192 void dm_linear_exit(void);
193
194 int dm_stripe_init(void);
195 void dm_stripe_exit(void);
196
197 /*
198 * mapped_device operations
199 */
200 void dm_destroy(struct mapped_device *md);
201 void dm_destroy_immediate(struct mapped_device *md);
202 int dm_open_count(struct mapped_device *md);
203 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
204 int dm_cancel_deferred_remove(struct mapped_device *md);
205 int dm_request_based(struct mapped_device *md);
206 int dm_get_table_device(struct mapped_device *md, dev_t dev, blk_mode_t mode,
207 struct dm_dev **result);
208 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
209
210 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
211 unsigned int cookie, bool need_resize_uevent);
212
213 int dm_io_init(void);
214 void dm_io_exit(void);
215
216 int dm_kcopyd_init(void);
217 void dm_kcopyd_exit(void);
218
219 /*
220 * Mempool operations
221 */
222 void dm_free_md_mempools(struct dm_md_mempools *pools);
223
224 /*
225 * Various helpers
226 */
227 unsigned int dm_get_reserved_bio_based_ios(void);
228
229 #define DM_HASH_LOCKS_MAX 64
230
dm_num_hash_locks(void)231 static inline unsigned int dm_num_hash_locks(void)
232 {
233 unsigned int num_locks = roundup_pow_of_two(num_online_cpus()) << 1;
234
235 return min_t(unsigned int, num_locks, DM_HASH_LOCKS_MAX);
236 }
237
238 #define DM_HASH_LOCKS_MULT 4294967291ULL
239 #define DM_HASH_LOCKS_SHIFT 6
240
dm_hash_locks_index(sector_t block,unsigned int num_locks)241 static inline unsigned int dm_hash_locks_index(sector_t block,
242 unsigned int num_locks)
243 {
244 sector_t h1 = (block * DM_HASH_LOCKS_MULT) >> DM_HASH_LOCKS_SHIFT;
245 sector_t h2 = h1 >> DM_HASH_LOCKS_SHIFT;
246
247 return (h1 ^ h2) & (num_locks - 1);
248 }
249
250 #endif
251