xref: /openbmc/linux/drivers/md/dm.h (revision 63705da3)
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_get_target(struct dm_table *t, unsigned int index);
57 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
58 bool dm_table_has_no_data_devices(struct dm_table *table);
59 int dm_calculate_queue_limits(struct dm_table *table,
60 			      struct queue_limits *limits);
61 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
62 			      struct queue_limits *limits);
63 struct list_head *dm_table_get_devices(struct dm_table *t);
64 void dm_table_presuspend_targets(struct dm_table *t);
65 void dm_table_presuspend_undo_targets(struct dm_table *t);
66 void dm_table_postsuspend_targets(struct dm_table *t);
67 int dm_table_resume_targets(struct dm_table *t);
68 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
69 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
70 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
71 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
72 bool dm_table_bio_based(struct dm_table *t);
73 bool dm_table_request_based(struct dm_table *t);
74 void dm_table_free_md_mempools(struct dm_table *t);
75 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
76 bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,
77 			   int *blocksize);
78 int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
79 			   sector_t start, sector_t len, void *data);
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, enum dm_queue_mode type);
84 enum dm_queue_mode 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, struct dm_table *t);
88 
89 /*
90  * To check whether the target type is bio-based or not (request-based).
91  */
92 #define dm_target_bio_based(t) ((t)->type->map != NULL)
93 
94 /*
95  * To check whether the target type is request-based or not (bio-based).
96  */
97 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
98 
99 /*
100  * To check whether the target type is a hybrid (capable of being
101  * either request-based or bio-based).
102  */
103 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
104 
105 /*
106  * Zoned targets related functions.
107  */
108 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q);
109 void dm_zone_endio(struct dm_io *io, struct bio *clone);
110 #ifdef CONFIG_BLK_DEV_ZONED
111 void dm_cleanup_zoned_dev(struct mapped_device *md);
112 int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
113 			unsigned int nr_zones, report_zones_cb cb, void *data);
114 bool dm_is_zone_write(struct mapped_device *md, struct bio *bio);
115 int dm_zone_map_bio(struct dm_target_io *io);
116 #else
117 static inline void dm_cleanup_zoned_dev(struct mapped_device *md) {}
118 #define dm_blk_report_zones	NULL
119 static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
120 {
121 	return false;
122 }
123 static inline int dm_zone_map_bio(struct dm_target_io *tio)
124 {
125 	return DM_MAPIO_KILL;
126 }
127 #endif
128 
129 /*-----------------------------------------------------------------
130  * A registry of target types.
131  *---------------------------------------------------------------*/
132 int dm_target_init(void);
133 void dm_target_exit(void);
134 struct target_type *dm_get_target_type(const char *name);
135 void dm_put_target_type(struct target_type *tt);
136 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
137 					void *param), void *param);
138 
139 int dm_split_args(int *argc, char ***argvp, char *input);
140 
141 /*
142  * Is this mapped_device being deleted?
143  */
144 int dm_deleting_md(struct mapped_device *md);
145 
146 /*
147  * Is this mapped_device suspended?
148  */
149 int dm_suspended_md(struct mapped_device *md);
150 
151 /*
152  * Internal suspend and resume methods.
153  */
154 int dm_suspended_internally_md(struct mapped_device *md);
155 void dm_internal_suspend_fast(struct mapped_device *md);
156 void dm_internal_resume_fast(struct mapped_device *md);
157 void dm_internal_suspend_noflush(struct mapped_device *md);
158 void dm_internal_resume(struct mapped_device *md);
159 
160 /*
161  * Test if the device is scheduled for deferred remove.
162  */
163 int dm_test_deferred_remove_flag(struct mapped_device *md);
164 
165 /*
166  * Try to remove devices marked for deferred removal.
167  */
168 void dm_deferred_remove(void);
169 
170 /*
171  * The device-mapper can be driven through one of two interfaces;
172  * ioctl or filesystem, depending which patch you have applied.
173  */
174 int dm_interface_init(void);
175 void dm_interface_exit(void);
176 
177 /*
178  * sysfs interface
179  */
180 int dm_sysfs_init(struct mapped_device *md);
181 void dm_sysfs_exit(struct mapped_device *md);
182 struct kobject *dm_kobject(struct mapped_device *md);
183 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
184 
185 /*
186  * The kobject helper
187  */
188 void dm_kobject_release(struct kobject *kobj);
189 
190 /*
191  * Targets for linear and striped mappings
192  */
193 int dm_linear_init(void);
194 void dm_linear_exit(void);
195 
196 int dm_stripe_init(void);
197 void dm_stripe_exit(void);
198 
199 /*
200  * mapped_device operations
201  */
202 void dm_destroy(struct mapped_device *md);
203 void dm_destroy_immediate(struct mapped_device *md);
204 int dm_open_count(struct mapped_device *md);
205 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
206 int dm_cancel_deferred_remove(struct mapped_device *md);
207 int dm_request_based(struct mapped_device *md);
208 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
209 			struct dm_dev **result);
210 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
211 
212 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
213 		      unsigned cookie);
214 
215 void dm_internal_suspend(struct mapped_device *md);
216 void dm_internal_resume(struct mapped_device *md);
217 
218 int dm_io_init(void);
219 void dm_io_exit(void);
220 
221 int dm_kcopyd_init(void);
222 void dm_kcopyd_exit(void);
223 
224 /*
225  * Mempool operations
226  */
227 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
228 					    unsigned integrity, unsigned per_bio_data_size,
229 					    unsigned min_pool_size);
230 void dm_free_md_mempools(struct dm_md_mempools *pools);
231 
232 /*
233  * Various helpers
234  */
235 unsigned dm_get_reserved_bio_based_ios(void);
236 
237 #endif
238