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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 | |
45cbcd79 | 42 | * = 1: simple remap complete |
2e93ccc1 | 43 | * = 2: The target wants to push back the io |
1da177e4 LT |
44 | */ |
45 | typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, | |
46 | union map_info *map_context); | |
47 | ||
48 | /* | |
49 | * Returns: | |
50 | * < 0 : error (currently ignored) | |
51 | * 0 : ended successfully | |
52 | * 1 : for some reason the io has still not completed (eg, | |
53 | * multipath target might want to requeue a failed io). | |
2e93ccc1 | 54 | * 2 : The target wants to push back the io |
1da177e4 LT |
55 | */ |
56 | typedef int (*dm_endio_fn) (struct dm_target *ti, | |
57 | struct bio *bio, int error, | |
58 | union map_info *map_context); | |
59 | ||
999d8168 | 60 | typedef void (*dm_flush_fn) (struct dm_target *ti); |
1da177e4 LT |
61 | typedef void (*dm_presuspend_fn) (struct dm_target *ti); |
62 | typedef void (*dm_postsuspend_fn) (struct dm_target *ti); | |
8757b776 | 63 | typedef int (*dm_preresume_fn) (struct dm_target *ti); |
1da177e4 LT |
64 | typedef void (*dm_resume_fn) (struct dm_target *ti); |
65 | ||
66 | typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, | |
67 | char *result, unsigned int maxlen); | |
68 | ||
69 | typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); | |
70 | ||
aa129a22 MB |
71 | typedef int (*dm_ioctl_fn) (struct dm_target *ti, struct inode *inode, |
72 | struct file *filp, unsigned int cmd, | |
73 | unsigned long arg); | |
74 | ||
1da177e4 LT |
75 | void dm_error(const char *message); |
76 | ||
3cb40214 BR |
77 | /* |
78 | * Combine device limits. | |
79 | */ | |
80 | void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev); | |
81 | ||
1da177e4 LT |
82 | /* |
83 | * Constructors should call these functions to ensure destination devices | |
84 | * are opened/closed correctly. | |
85 | * FIXME: too many arguments. | |
86 | */ | |
87 | int dm_get_device(struct dm_target *ti, const char *path, sector_t start, | |
88 | sector_t len, int mode, struct dm_dev **result); | |
89 | void dm_put_device(struct dm_target *ti, struct dm_dev *d); | |
90 | ||
91 | /* | |
92 | * Information about a target type | |
93 | */ | |
94 | struct target_type { | |
95 | const char *name; | |
96 | struct module *module; | |
17b2f66f | 97 | unsigned version[3]; |
1da177e4 LT |
98 | dm_ctr_fn ctr; |
99 | dm_dtr_fn dtr; | |
100 | dm_map_fn map; | |
101 | dm_endio_fn end_io; | |
999d8168 | 102 | dm_flush_fn flush; |
1da177e4 LT |
103 | dm_presuspend_fn presuspend; |
104 | dm_postsuspend_fn postsuspend; | |
8757b776 | 105 | dm_preresume_fn preresume; |
1da177e4 LT |
106 | dm_resume_fn resume; |
107 | dm_status_fn status; | |
108 | dm_message_fn message; | |
aa129a22 | 109 | dm_ioctl_fn ioctl; |
1da177e4 LT |
110 | }; |
111 | ||
112 | struct io_restrictions { | |
3ee247eb | 113 | unsigned int max_sectors; |
1da177e4 LT |
114 | unsigned short max_phys_segments; |
115 | unsigned short max_hw_segments; | |
116 | unsigned short hardsect_size; | |
117 | unsigned int max_segment_size; | |
118 | unsigned long seg_boundary_mask; | |
969429b5 | 119 | unsigned char no_cluster; /* inverted so that 0 is default */ |
1da177e4 LT |
120 | }; |
121 | ||
122 | struct dm_target { | |
123 | struct dm_table *table; | |
124 | struct target_type *type; | |
125 | ||
126 | /* target limits */ | |
127 | sector_t begin; | |
128 | sector_t len; | |
129 | ||
130 | /* FIXME: turn this into a mask, and merge with io_restrictions */ | |
131 | /* Always a power of 2 */ | |
132 | sector_t split_io; | |
133 | ||
134 | /* | |
135 | * These are automatically filled in by | |
136 | * dm_table_get_device. | |
137 | */ | |
138 | struct io_restrictions limits; | |
139 | ||
140 | /* target specific data */ | |
141 | void *private; | |
142 | ||
143 | /* Used to provide an error string from the ctr */ | |
144 | char *error; | |
145 | }; | |
146 | ||
147 | int dm_register_target(struct target_type *t); | |
148 | int dm_unregister_target(struct target_type *t); | |
149 | ||
17b2f66f AK |
150 | |
151 | /*----------------------------------------------------------------- | |
152 | * Functions for creating and manipulating mapped devices. | |
153 | * Drop the reference with dm_put when you finish with the object. | |
154 | *---------------------------------------------------------------*/ | |
155 | ||
156 | /* | |
157 | * DM_ANY_MINOR chooses the next available minor number. | |
158 | */ | |
159 | #define DM_ANY_MINOR (-1) | |
160 | int dm_create(int minor, struct mapped_device **md); | |
161 | ||
162 | /* | |
163 | * Reference counting for md. | |
164 | */ | |
165 | struct mapped_device *dm_get_md(dev_t dev); | |
166 | void dm_get(struct mapped_device *md); | |
167 | void dm_put(struct mapped_device *md); | |
168 | ||
169 | /* | |
170 | * An arbitrary pointer may be stored alongside a mapped device. | |
171 | */ | |
172 | void dm_set_mdptr(struct mapped_device *md, void *ptr); | |
173 | void *dm_get_mdptr(struct mapped_device *md); | |
174 | ||
175 | /* | |
176 | * A device can still be used while suspended, but I/O is deferred. | |
177 | */ | |
a3d77d35 | 178 | int dm_suspend(struct mapped_device *md, unsigned suspend_flags); |
17b2f66f AK |
179 | int dm_resume(struct mapped_device *md); |
180 | ||
181 | /* | |
182 | * Event functions. | |
183 | */ | |
184 | uint32_t dm_get_event_nr(struct mapped_device *md); | |
185 | int dm_wait_event(struct mapped_device *md, int event_nr); | |
186 | ||
187 | /* | |
188 | * Info functions. | |
189 | */ | |
72d94861 | 190 | const char *dm_device_name(struct mapped_device *md); |
17b2f66f AK |
191 | struct gendisk *dm_disk(struct mapped_device *md); |
192 | int dm_suspended(struct mapped_device *md); | |
2e93ccc1 | 193 | int dm_noflush_suspending(struct dm_target *ti); |
17b2f66f AK |
194 | |
195 | /* | |
196 | * Geometry functions. | |
197 | */ | |
198 | int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
199 | int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo); | |
200 | ||
201 | ||
202 | /*----------------------------------------------------------------- | |
203 | * Functions for manipulating device-mapper tables. | |
204 | *---------------------------------------------------------------*/ | |
205 | ||
206 | /* | |
207 | * First create an empty table. | |
208 | */ | |
209 | int dm_table_create(struct dm_table **result, int mode, | |
210 | unsigned num_targets, struct mapped_device *md); | |
211 | ||
212 | /* | |
213 | * Then call this once for each target. | |
214 | */ | |
215 | int dm_table_add_target(struct dm_table *t, const char *type, | |
216 | sector_t start, sector_t len, char *params); | |
217 | ||
218 | /* | |
219 | * Finally call this to make the table ready for use. | |
220 | */ | |
221 | int dm_table_complete(struct dm_table *t); | |
222 | ||
223 | /* | |
224 | * Table reference counting. | |
225 | */ | |
226 | struct dm_table *dm_get_table(struct mapped_device *md); | |
227 | void dm_table_get(struct dm_table *t); | |
228 | void dm_table_put(struct dm_table *t); | |
229 | ||
230 | /* | |
231 | * Queries | |
232 | */ | |
233 | sector_t dm_table_get_size(struct dm_table *t); | |
234 | unsigned int dm_table_get_num_targets(struct dm_table *t); | |
235 | int dm_table_get_mode(struct dm_table *t); | |
236 | struct mapped_device *dm_table_get_md(struct dm_table *t); | |
237 | ||
238 | /* | |
239 | * Trigger an event. | |
240 | */ | |
241 | void dm_table_event(struct dm_table *t); | |
242 | ||
243 | /* | |
244 | * The device must be suspended before calling this method. | |
245 | */ | |
246 | int dm_swap_table(struct mapped_device *md, struct dm_table *t); | |
247 | ||
c2ade42d DT |
248 | /* |
249 | * Prepare a table for a device that will error all I/O. | |
250 | * To make it active, call dm_suspend(), dm_swap_table() then dm_resume(). | |
251 | */ | |
252 | int dm_create_error_table(struct dm_table **result, struct mapped_device *md); | |
253 | ||
17b2f66f AK |
254 | #endif /* __KERNEL__ */ |
255 | #endif /* _LINUX_DEVICE_MAPPER_H */ |