xref: /openbmc/linux/drivers/md/dm.h (revision be2b81b5)
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 
24 #include "dm-stats.h"
25 
26 /*
27  * Suspend feature flags
28  */
29 #define DM_SUSPEND_LOCKFS_FLAG		(1 << 0)
30 #define DM_SUSPEND_NOFLUSH_FLAG		(1 << 1)
31 
32 /*
33  * Status feature flags
34  */
35 #define DM_STATUS_NOFLUSH_FLAG		(1 << 0)
36 
37 /*
38  * List of devices that a metadevice uses and should open/close.
39  */
40 struct dm_dev_internal {
41 	struct list_head list;
42 	refcount_t count;
43 	struct dm_dev *dm_dev;
44 };
45 
46 struct dm_table;
47 struct dm_md_mempools;
48 struct dm_target_io;
49 struct dm_io;
50 
51 /*-----------------------------------------------------------------
52  * Internal table functions.
53  *---------------------------------------------------------------*/
54 void dm_table_event_callback(struct dm_table *t,
55 			     void (*fn)(void *), void *context);
56 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
57 bool dm_table_has_no_data_devices(struct dm_table *table);
58 int dm_calculate_queue_limits(struct dm_table *table,
59 			      struct queue_limits *limits);
60 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
61 			      struct queue_limits *limits);
62 struct list_head *dm_table_get_devices(struct dm_table *t);
63 void dm_table_presuspend_targets(struct dm_table *t);
64 void dm_table_presuspend_undo_targets(struct dm_table *t);
65 void dm_table_postsuspend_targets(struct dm_table *t);
66 int dm_table_resume_targets(struct dm_table *t);
67 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
68 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
69 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
70 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
71 bool dm_table_bio_based(struct dm_table *t);
72 bool dm_table_request_based(struct dm_table *t);
73 
74 void dm_lock_md_type(struct mapped_device *md);
75 void dm_unlock_md_type(struct mapped_device *md);
76 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
77 enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
78 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
79 
80 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
81 
82 /*
83  * To check whether the target type is bio-based or not (request-based).
84  */
85 #define dm_target_bio_based(t) ((t)->type->map != NULL)
86 
87 /*
88  * To check whether the target type is request-based or not (bio-based).
89  */
90 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
91 
92 /*
93  * To check whether the target type is a hybrid (capable of being
94  * either request-based or bio-based).
95  */
96 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
97 
98 /*
99  * Zoned targets related functions.
100  */
101 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q);
102 void dm_zone_endio(struct dm_io *io, struct bio *clone);
103 #ifdef CONFIG_BLK_DEV_ZONED
104 void dm_cleanup_zoned_dev(struct mapped_device *md);
105 int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
106 			unsigned int nr_zones, report_zones_cb cb, void *data);
107 bool dm_is_zone_write(struct mapped_device *md, struct bio *bio);
108 int dm_zone_map_bio(struct dm_target_io *io);
109 #else
110 static inline void dm_cleanup_zoned_dev(struct mapped_device *md) {}
111 #define dm_blk_report_zones	NULL
112 static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
113 {
114 	return false;
115 }
116 static inline int dm_zone_map_bio(struct dm_target_io *tio)
117 {
118 	return DM_MAPIO_KILL;
119 }
120 #endif
121 
122 /*-----------------------------------------------------------------
123  * A registry of target types.
124  *---------------------------------------------------------------*/
125 int dm_target_init(void);
126 void dm_target_exit(void);
127 struct target_type *dm_get_target_type(const char *name);
128 void dm_put_target_type(struct target_type *tt);
129 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
130 					void *param), void *param);
131 
132 int dm_split_args(int *argc, char ***argvp, char *input);
133 
134 /*
135  * Is this mapped_device being deleted?
136  */
137 int dm_deleting_md(struct mapped_device *md);
138 
139 /*
140  * Is this mapped_device suspended?
141  */
142 int dm_suspended_md(struct mapped_device *md);
143 
144 /*
145  * Internal suspend and resume methods.
146  */
147 int dm_suspended_internally_md(struct mapped_device *md);
148 void dm_internal_suspend_fast(struct mapped_device *md);
149 void dm_internal_resume_fast(struct mapped_device *md);
150 void dm_internal_suspend_noflush(struct mapped_device *md);
151 void dm_internal_resume(struct mapped_device *md);
152 
153 /*
154  * Test if the device is scheduled for deferred remove.
155  */
156 int dm_test_deferred_remove_flag(struct mapped_device *md);
157 
158 /*
159  * Try to remove devices marked for deferred removal.
160  */
161 void dm_deferred_remove(void);
162 
163 /*
164  * The device-mapper can be driven through one of two interfaces;
165  * ioctl or filesystem, depending which patch you have applied.
166  */
167 int dm_interface_init(void);
168 void dm_interface_exit(void);
169 
170 /*
171  * sysfs interface
172  */
173 int dm_sysfs_init(struct mapped_device *md);
174 void dm_sysfs_exit(struct mapped_device *md);
175 struct kobject *dm_kobject(struct mapped_device *md);
176 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
177 
178 /*
179  * The kobject helper
180  */
181 void dm_kobject_release(struct kobject *kobj);
182 
183 /*
184  * Targets for linear and striped mappings
185  */
186 int dm_linear_init(void);
187 void dm_linear_exit(void);
188 
189 int dm_stripe_init(void);
190 void dm_stripe_exit(void);
191 
192 /*
193  * mapped_device operations
194  */
195 void dm_destroy(struct mapped_device *md);
196 void dm_destroy_immediate(struct mapped_device *md);
197 int dm_open_count(struct mapped_device *md);
198 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
199 int dm_cancel_deferred_remove(struct mapped_device *md);
200 int dm_request_based(struct mapped_device *md);
201 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
202 			struct dm_dev **result);
203 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
204 
205 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
206 		      unsigned cookie);
207 
208 void dm_internal_suspend(struct mapped_device *md);
209 void dm_internal_resume(struct mapped_device *md);
210 
211 int dm_io_init(void);
212 void dm_io_exit(void);
213 
214 int dm_kcopyd_init(void);
215 void dm_kcopyd_exit(void);
216 
217 /*
218  * Mempool operations
219  */
220 void dm_free_md_mempools(struct dm_md_mempools *pools);
221 
222 /*
223  * Various helpers
224  */
225 unsigned dm_get_reserved_bio_based_ios(void);
226 
227 #endif
228