xref: /openbmc/linux/drivers/md/dm.h (revision 25879d7b)
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  *---------------------------------------------------------------
53  * Internal table functions.
54  *---------------------------------------------------------------
55  */
56 void dm_table_event_callback(struct dm_table *t,
57 			     void (*fn)(void *), void *context);
58 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
59 bool dm_table_has_no_data_devices(struct dm_table *table);
60 int dm_calculate_queue_limits(struct dm_table *table,
61 			      struct queue_limits *limits);
62 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
63 			      struct queue_limits *limits);
64 struct list_head *dm_table_get_devices(struct dm_table *t);
65 void dm_table_presuspend_targets(struct dm_table *t);
66 void dm_table_presuspend_undo_targets(struct dm_table *t);
67 void dm_table_postsuspend_targets(struct dm_table *t);
68 int dm_table_resume_targets(struct dm_table *t);
69 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
70 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
71 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
72 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
73 bool dm_table_bio_based(struct dm_table *t);
74 bool dm_table_request_based(struct dm_table *t);
75 
76 void dm_lock_md_type(struct mapped_device *md);
77 void dm_unlock_md_type(struct mapped_device *md);
78 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
79 enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
80 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
81 
82 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
83 
84 /*
85  * To check whether the target type is bio-based or not (request-based).
86  */
87 #define dm_target_bio_based(t) ((t)->type->map != NULL)
88 
89 /*
90  * To check whether the target type is request-based or not (bio-based).
91  */
92 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
93 
94 /*
95  * To check whether the target type is a hybrid (capable of being
96  * either request-based or bio-based).
97  */
98 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
99 
100 /*
101  * Zoned targets related functions.
102  */
103 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q);
104 void dm_zone_endio(struct dm_io *io, struct bio *clone);
105 #ifdef CONFIG_BLK_DEV_ZONED
106 void dm_cleanup_zoned_dev(struct mapped_device *md);
107 int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
108 			unsigned int nr_zones, report_zones_cb cb, void *data);
109 bool dm_is_zone_write(struct mapped_device *md, struct bio *bio);
110 int dm_zone_map_bio(struct dm_target_io *io);
111 #else
112 static inline void dm_cleanup_zoned_dev(struct mapped_device *md) {}
113 #define dm_blk_report_zones	NULL
114 static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
115 {
116 	return false;
117 }
118 static inline int dm_zone_map_bio(struct dm_target_io *tio)
119 {
120 	return DM_MAPIO_KILL;
121 }
122 #endif
123 
124 /*
125  *---------------------------------------------------------------
126  * A registry of target types.
127  *---------------------------------------------------------------
128  */
129 int dm_target_init(void);
130 void dm_target_exit(void);
131 struct target_type *dm_get_target_type(const char *name);
132 void dm_put_target_type(struct target_type *tt);
133 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
134 					void *param), void *param);
135 
136 int dm_split_args(int *argc, char ***argvp, char *input);
137 
138 /*
139  * Is this mapped_device being deleted?
140  */
141 int dm_deleting_md(struct mapped_device *md);
142 
143 /*
144  * Is this mapped_device suspended?
145  */
146 int dm_suspended_md(struct mapped_device *md);
147 
148 /*
149  * Internal suspend and resume methods.
150  */
151 int dm_suspended_internally_md(struct mapped_device *md);
152 void dm_internal_suspend_fast(struct mapped_device *md);
153 void dm_internal_resume_fast(struct mapped_device *md);
154 void dm_internal_suspend_noflush(struct mapped_device *md);
155 void dm_internal_resume(struct mapped_device *md);
156 
157 /*
158  * Test if the device is scheduled for deferred remove.
159  */
160 int dm_test_deferred_remove_flag(struct mapped_device *md);
161 
162 /*
163  * Try to remove devices marked for deferred removal.
164  */
165 void dm_deferred_remove(void);
166 
167 /*
168  * The device-mapper can be driven through one of two interfaces;
169  * ioctl or filesystem, depending which patch you have applied.
170  */
171 int dm_interface_init(void);
172 void dm_interface_exit(void);
173 
174 /*
175  * sysfs interface
176  */
177 int dm_sysfs_init(struct mapped_device *md);
178 void dm_sysfs_exit(struct mapped_device *md);
179 struct kobject *dm_kobject(struct mapped_device *md);
180 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
181 
182 /*
183  * The kobject helper
184  */
185 void dm_kobject_release(struct kobject *kobj);
186 
187 /*
188  * Targets for linear and striped mappings
189  */
190 int dm_linear_init(void);
191 void dm_linear_exit(void);
192 
193 int dm_stripe_init(void);
194 void dm_stripe_exit(void);
195 
196 /*
197  * mapped_device operations
198  */
199 void dm_destroy(struct mapped_device *md);
200 void dm_destroy_immediate(struct mapped_device *md);
201 int dm_open_count(struct mapped_device *md);
202 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
203 int dm_cancel_deferred_remove(struct mapped_device *md);
204 int dm_request_based(struct mapped_device *md);
205 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
206 			struct dm_dev **result);
207 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
208 
209 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
210 		      unsigned int cookie, bool need_resize_uevent);
211 
212 void dm_internal_suspend(struct mapped_device *md);
213 void dm_internal_resume(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 void dm_free_md_mempools(struct dm_md_mempools *pools);
225 
226 /*
227  * Various helpers
228  */
229 unsigned int dm_get_reserved_bio_based_ios(void);
230 
231 #endif
232