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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001 Sistina Software (UK) Limited. | |
3 | * Copyright (C) 2004 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This file is released under the LGPL. | |
6 | */ | |
7 | ||
8 | #ifndef _LINUX_DEVICE_MAPPER_H | |
9 | #define _LINUX_DEVICE_MAPPER_H | |
10 | ||
17b2f66f AK |
11 | #ifdef __KERNEL__ |
12 | ||
1da177e4 LT |
13 | struct dm_target; |
14 | struct dm_table; | |
15 | struct dm_dev; | |
17b2f66f | 16 | struct mapped_device; |
1da177e4 LT |
17 | |
18 | typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; | |
19 | ||
20 | union map_info { | |
21 | void *ptr; | |
22 | unsigned long long ll; | |
23 | }; | |
24 | ||
25 | /* | |
26 | * In the constructor the target parameter will already have the | |
27 | * table, type, begin and len fields filled in. | |
28 | */ | |
29 | typedef int (*dm_ctr_fn) (struct dm_target *target, | |
30 | unsigned int argc, char **argv); | |
31 | ||
32 | /* | |
33 | * The destructor doesn't need to free the dm_target, just | |
34 | * anything hidden ti->private. | |
35 | */ | |
36 | typedef void (*dm_dtr_fn) (struct dm_target *ti); | |
37 | ||
38 | /* | |
39 | * The map function must return: | |
40 | * < 0: error | |
41 | * = 0: The target will handle the io by resubmitting it later | |
42 | * > 0: simple remap complete | |
43 | */ | |
44 | typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, | |
45 | union map_info *map_context); | |
46 | ||
47 | /* | |
48 | * Returns: | |
49 | * < 0 : error (currently ignored) | |
50 | * 0 : ended successfully | |
51 | * 1 : for some reason the io has still not completed (eg, | |
52 | * multipath target might want to requeue a failed io). | |
53 | */ | |
54 | typedef int (*dm_endio_fn) (struct dm_target *ti, | |
55 | struct bio *bio, int error, | |
56 | union map_info *map_context); | |
57 | ||
999d8168 | 58 | typedef void (*dm_flush_fn) (struct dm_target *ti); |
1da177e4 LT |
59 | typedef void (*dm_presuspend_fn) (struct dm_target *ti); |
60 | typedef void (*dm_postsuspend_fn) (struct dm_target *ti); | |
8757b776 | 61 | typedef int (*dm_preresume_fn) (struct dm_target *ti); |
1da177e4 LT |
62 | typedef void (*dm_resume_fn) (struct dm_target *ti); |
63 | ||
64 | typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, | |
65 | char *result, unsigned int maxlen); | |
66 | ||
67 | typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); | |
68 | ||
aa129a22 MB |
69 | typedef int (*dm_ioctl_fn) (struct dm_target *ti, struct inode *inode, |
70 | struct file *filp, unsigned int cmd, | |
71 | unsigned long arg); | |
72 | ||
1da177e4 LT |
73 | void dm_error(const char *message); |
74 | ||
3cb40214 BR |
75 | /* |
76 | * Combine device limits. | |
77 | */ | |
78 | void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev); | |
79 | ||
1da177e4 LT |
80 | /* |
81 | * Constructors should call these functions to ensure destination devices | |
82 | * are opened/closed correctly. | |
83 | * FIXME: too many arguments. | |
84 | */ | |
85 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, | |
86 | sector_t len, int mode, struct dm_dev **result); | |
87 | void dm_put_device(struct dm_target *ti, struct dm_dev *d); | |
88 | ||
89 | /* | |
90 | * Information about a target type | |
91 | */ | |
92 | struct target_type { | |
93 | const char *name; | |
94 | struct module *module; | |
17b2f66f | 95 | unsigned version[3]; |
1da177e4 LT |
96 | dm_ctr_fn ctr; |
97 | dm_dtr_fn dtr; | |
98 | dm_map_fn map; | |
99 | dm_endio_fn end_io; | |
999d8168 | 100 | dm_flush_fn flush; |
1da177e4 LT |
101 | dm_presuspend_fn presuspend; |
102 | dm_postsuspend_fn postsuspend; | |
8757b776 | 103 | dm_preresume_fn preresume; |
1da177e4 LT |
104 | dm_resume_fn resume; |
105 | dm_status_fn status; | |
106 | dm_message_fn message; | |
aa129a22 | 107 | dm_ioctl_fn ioctl; |
1da177e4 LT |
108 | }; |
109 | ||
110 | struct io_restrictions { | |
3ee247eb | 111 | unsigned int max_sectors; |
1da177e4 LT |
112 | unsigned short max_phys_segments; |
113 | unsigned short max_hw_segments; | |
114 | unsigned short hardsect_size; | |
115 | unsigned int max_segment_size; | |
116 | unsigned long seg_boundary_mask; | |
969429b5 | 117 | unsigned char no_cluster; /* inverted so that 0 is default */ |
1da177e4 LT |
118 | }; |
119 | ||
120 | struct dm_target { | |
121 | struct dm_table *table; | |
122 | struct target_type *type; | |
123 | ||
124 | /* target limits */ | |
125 | sector_t begin; | |
126 | sector_t len; | |
127 | ||
128 | /* FIXME: turn this into a mask, and merge with io_restrictions */ | |
129 | /* Always a power of 2 */ | |
130 | sector_t split_io; | |
131 | ||
132 | /* | |
133 | * These are automatically filled in by | |
134 | * dm_table_get_device. | |
135 | */ | |
136 | struct io_restrictions limits; | |
137 | ||
138 | /* target specific data */ | |
139 | void *private; | |
140 | ||
141 | /* Used to provide an error string from the ctr */ | |
142 | char *error; | |
143 | }; | |
144 | ||
145 | int dm_register_target(struct target_type *t); | |
146 | int dm_unregister_target(struct target_type *t); | |
147 | ||
17b2f66f AK |
148 | |
149 | /*----------------------------------------------------------------- | |
150 | * Functions for creating and manipulating mapped devices. | |
151 | * Drop the reference with dm_put when you finish with the object. | |
152 | *---------------------------------------------------------------*/ | |
153 | ||
154 | /* | |
155 | * DM_ANY_MINOR chooses the next available minor number. | |
156 | */ | |
157 | #define DM_ANY_MINOR (-1) | |
158 | int dm_create(int minor, struct mapped_device **md); | |
159 | ||
160 | /* | |
161 | * Reference counting for md. | |
162 | */ | |
163 | struct mapped_device *dm_get_md(dev_t dev); | |
164 | void dm_get(struct mapped_device *md); | |
165 | void dm_put(struct mapped_device *md); | |
166 | ||
167 | /* | |
168 | * An arbitrary pointer may be stored alongside a mapped device. | |
169 | */ | |
170 | void dm_set_mdptr(struct mapped_device *md, void *ptr); | |
171 | void *dm_get_mdptr(struct mapped_device *md); | |
172 | ||
173 | /* | |
174 | * A device can still be used while suspended, but I/O is deferred. | |
175 | */ | |
a3d77d35 | 176 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags); |
17b2f66f AK |
177 | int dm_resume(struct mapped_device *md); |
178 | ||
179 | /* | |
180 | * Event functions. | |
181 | */ | |
182 | uint32_t dm_get_event_nr(struct mapped_device *md); | |
183 | int dm_wait_event(struct mapped_device *md, int event_nr); | |
184 | ||
185 | /* | |
186 | * Info functions. | |
187 | */ | |
72d94861 | 188 | const char *dm_device_name(struct mapped_device *md); |
17b2f66f AK |
189 | struct gendisk *dm_disk(struct mapped_device *md); |
190 | int dm_suspended(struct mapped_device *md); | |
191 | ||
192 | /* | |
193 | * Geometry functions. | |
194 | */ | |
195 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
196 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
197 | ||
198 | ||
199 | /*----------------------------------------------------------------- | |
200 | * Functions for manipulating device-mapper tables. | |
201 | *---------------------------------------------------------------*/ | |
202 | ||
203 | /* | |
204 | * First create an empty table. | |
205 | */ | |
206 | int dm_table_create(struct dm_table **result, int mode, | |
207 | unsigned num_targets, struct mapped_device *md); | |
208 | ||
209 | /* | |
210 | * Then call this once for each target. | |
211 | */ | |
212 | int dm_table_add_target(struct dm_table *t, const char *type, | |
213 | sector_t start, sector_t len, char *params); | |
214 | ||
215 | /* | |
216 | * Finally call this to make the table ready for use. | |
217 | */ | |
218 | int dm_table_complete(struct dm_table *t); | |
219 | ||
220 | /* | |
221 | * Table reference counting. | |
222 | */ | |
223 | struct dm_table *dm_get_table(struct mapped_device *md); | |
224 | void dm_table_get(struct dm_table *t); | |
225 | void dm_table_put(struct dm_table *t); | |
226 | ||
227 | /* | |
228 | * Queries | |
229 | */ | |
230 | sector_t dm_table_get_size(struct dm_table *t); | |
231 | unsigned int dm_table_get_num_targets(struct dm_table *t); | |
232 | int dm_table_get_mode(struct dm_table *t); | |
233 | struct mapped_device *dm_table_get_md(struct dm_table *t); | |
234 | ||
235 | /* | |
236 | * Trigger an event. | |
237 | */ | |
238 | void dm_table_event(struct dm_table *t); | |
239 | ||
240 | /* | |
241 | * The device must be suspended before calling this method. | |
242 | */ | |
243 | int dm_swap_table(struct mapped_device *md, struct dm_table *t); | |
244 | ||
c2ade42d DT |
245 | /* |
246 | * Prepare a table for a device that will error all I/O. | |
247 | * To make it active, call dm_suspend(), dm_swap_table() then dm_resume(). | |
248 | */ | |
249 | int dm_create_error_table(struct dm_table **result, struct mapped_device *md); | |
250 | ||
17b2f66f AK |
251 | #endif /* __KERNEL__ */ |
252 | #endif /* _LINUX_DEVICE_MAPPER_H */ |