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[mirror_ubuntu-zesty-kernel.git] / drivers / md / dm.h
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/blkdev.h>
17 #include <linux/backing-dev.h>
18 #include <linux/hdreg.h>
19 #include <linux/completion.h>
20 #include <linux/kobject.h>
21
22 #include "dm-stats.h"
23
24 /*
25 * Suspend feature flags
26 */
27 #define DM_SUSPEND_LOCKFS_FLAG (1 << 0)
28 #define DM_SUSPEND_NOFLUSH_FLAG (1 << 1)
29
30 /*
31 * Status feature flags
32 */
33 #define DM_STATUS_NOFLUSH_FLAG (1 << 0)
34
35 /*
36 * Type of table and mapped_device's mempool
37 */
38 #define DM_TYPE_NONE 0
39 #define DM_TYPE_BIO_BASED 1
40 #define DM_TYPE_REQUEST_BASED 2
41 #define DM_TYPE_MQ_REQUEST_BASED 3
42
43 /*
44 * List of devices that a metadevice uses and should open/close.
45 */
46 struct dm_dev_internal {
47 struct list_head list;
48 atomic_t count;
49 struct dm_dev *dm_dev;
50 };
51
52 struct dm_table;
53 struct dm_md_mempools;
54
55 /*-----------------------------------------------------------------
56 * Internal table functions.
57 *---------------------------------------------------------------*/
58 void dm_table_destroy(struct dm_table *t);
59 void dm_table_event_callback(struct dm_table *t,
60 void (*fn)(void *), void *context);
61 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
62 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
63 bool dm_table_has_no_data_devices(struct dm_table *table);
64 int dm_calculate_queue_limits(struct dm_table *table,
65 struct queue_limits *limits);
66 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
67 struct queue_limits *limits);
68 struct list_head *dm_table_get_devices(struct dm_table *t);
69 void dm_table_presuspend_targets(struct dm_table *t);
70 void dm_table_presuspend_undo_targets(struct dm_table *t);
71 void dm_table_postsuspend_targets(struct dm_table *t);
72 int dm_table_resume_targets(struct dm_table *t);
73 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
74 unsigned dm_table_get_type(struct dm_table *t);
75 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
76 bool dm_table_request_based(struct dm_table *t);
77 bool dm_table_mq_request_based(struct dm_table *t);
78 void dm_table_free_md_mempools(struct dm_table *t);
79 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
80
81 void dm_lock_md_type(struct mapped_device *md);
82 void dm_unlock_md_type(struct mapped_device *md);
83 void dm_set_md_type(struct mapped_device *md, unsigned type);
84 unsigned dm_get_md_type(struct mapped_device *md);
85 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
86
87 int dm_setup_md_queue(struct mapped_device *md);
88
89 /*
90 * To check the return value from dm_table_find_target().
91 */
92 #define dm_target_is_valid(t) ((t)->table)
93
94 /*
95 * To check whether the target type is bio-based or not (request-based).
96 */
97 #define dm_target_bio_based(t) ((t)->type->map != NULL)
98
99 /*
100 * To check whether the target type is request-based or not (bio-based).
101 */
102 #define dm_target_request_based(t) (((t)->type->map_rq != NULL) || \
103 ((t)->type->clone_and_map_rq != NULL))
104
105 /*
106 * To check whether the target type is a hybrid (capable of being
107 * either request-based or bio-based).
108 */
109 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
110
111 /*-----------------------------------------------------------------
112 * A registry of target types.
113 *---------------------------------------------------------------*/
114 int dm_target_init(void);
115 void dm_target_exit(void);
116 struct target_type *dm_get_target_type(const char *name);
117 void dm_put_target_type(struct target_type *tt);
118 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
119 void *param), void *param);
120
121 int dm_split_args(int *argc, char ***argvp, char *input);
122
123 /*
124 * Is this mapped_device being deleted?
125 */
126 int dm_deleting_md(struct mapped_device *md);
127
128 /*
129 * Is this mapped_device suspended?
130 */
131 int dm_suspended_md(struct mapped_device *md);
132
133 /*
134 * Internal suspend and resume methods.
135 */
136 int dm_suspended_internally_md(struct mapped_device *md);
137 void dm_internal_suspend_fast(struct mapped_device *md);
138 void dm_internal_resume_fast(struct mapped_device *md);
139 void dm_internal_suspend_noflush(struct mapped_device *md);
140 void dm_internal_resume(struct mapped_device *md);
141
142 /*
143 * Test if the device is scheduled for deferred remove.
144 */
145 int dm_test_deferred_remove_flag(struct mapped_device *md);
146
147 /*
148 * Try to remove devices marked for deferred removal.
149 */
150 void dm_deferred_remove(void);
151
152 /*
153 * The device-mapper can be driven through one of two interfaces;
154 * ioctl or filesystem, depending which patch you have applied.
155 */
156 int dm_interface_init(void);
157 void dm_interface_exit(void);
158
159 /*
160 * sysfs interface
161 */
162 struct dm_kobject_holder {
163 struct kobject kobj;
164 struct completion completion;
165 };
166
167 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
168 {
169 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
170 }
171
172 int dm_sysfs_init(struct mapped_device *md);
173 void dm_sysfs_exit(struct mapped_device *md);
174 struct kobject *dm_kobject(struct mapped_device *md);
175 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
176
177 /*
178 * The kobject helper
179 */
180 void dm_kobject_release(struct kobject *kobj);
181
182 /*
183 * Targets for linear and striped mappings
184 */
185 int dm_linear_init(void);
186 void dm_linear_exit(void);
187
188 int dm_stripe_init(void);
189 void dm_stripe_exit(void);
190
191 /*
192 * mapped_device operations
193 */
194 void dm_destroy(struct mapped_device *md);
195 void dm_destroy_immediate(struct mapped_device *md);
196 int dm_open_count(struct mapped_device *md);
197 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
198 int dm_cancel_deferred_remove(struct mapped_device *md);
199 int dm_request_based(struct mapped_device *md);
200 sector_t dm_get_size(struct mapped_device *md);
201 struct request_queue *dm_get_md_queue(struct mapped_device *md);
202 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
203 struct dm_dev **result);
204 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
205 struct dm_stats *dm_get_stats(struct mapped_device *md);
206
207 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
208 unsigned cookie);
209
210 void dm_internal_suspend(struct mapped_device *md);
211 void dm_internal_resume(struct mapped_device *md);
212
213 bool dm_use_blk_mq(struct mapped_device *md);
214
215 int dm_io_init(void);
216 void dm_io_exit(void);
217
218 int dm_kcopyd_init(void);
219 void dm_kcopyd_exit(void);
220
221 /*
222 * Mempool operations
223 */
224 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type,
225 unsigned integrity, unsigned per_bio_data_size);
226 void dm_free_md_mempools(struct dm_md_mempools *pools);
227
228 /*
229 * Helpers that are used by DM core
230 */
231 unsigned dm_get_reserved_bio_based_ios(void);
232 unsigned dm_get_reserved_rq_based_ios(void);
233
234 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
235 {
236 return !maxlen || strlen(result) + 1 >= maxlen;
237 }
238
239 ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf);
240 ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
241 const char *buf, size_t count);
242
243 #endif