1 /* SPDX-License-Identifier: LGPL-2.0+ WITH Linux-syscall-note */
2 /*
3 * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
4 * Copyright (C) 2004 - 2009 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the LGPL.
7 */
8
9 #ifndef _LINUX_DM_IOCTL_V4_H
10 #define _LINUX_DM_IOCTL_V4_H
11
12 #include <linux/types.h>
13
14 #define DM_DIR "mapper" /* Slashes not supported */
15 #define DM_CONTROL_NODE "control"
16 #define DM_MAX_TYPE_NAME 16
17 #define DM_NAME_LEN 128
18 #define DM_UUID_LEN 129
19
20 /*
21 * A traditional ioctl interface for the device mapper.
22 *
23 * Each device can have two tables associated with it, an
24 * 'active' table which is the one currently used by io passing
25 * through the device, and an 'inactive' one which is a table
26 * that is being prepared as a replacement for the 'active' one.
27 *
28 * DM_VERSION:
29 * Just get the version information for the ioctl interface.
30 *
31 * DM_REMOVE_ALL:
32 * Remove all dm devices, destroy all tables. Only really used
33 * for debug.
34 *
35 * DM_LIST_DEVICES:
36 * Get a list of all the dm device names.
37 *
38 * DM_DEV_CREATE:
39 * Create a new device, neither the 'active' or 'inactive' table
40 * slots will be filled. The device will be in suspended state
41 * after creation, however any io to the device will get errored
42 * since it will be out-of-bounds.
43 *
44 * DM_DEV_REMOVE:
45 * Remove a device, destroy any tables.
46 *
47 * DM_DEV_RENAME:
48 * Rename a device or set its uuid if none was previously supplied.
49 *
50 * DM_SUSPEND:
51 * This performs both suspend and resume, depending which flag is
52 * passed in.
53 * Suspend: This command will not return until all pending io to
54 * the device has completed. Further io will be deferred until
55 * the device is resumed.
56 * Resume: It is no longer an error to issue this command on an
57 * unsuspended device. If a table is present in the 'inactive'
58 * slot, it will be moved to the active slot, then the old table
59 * from the active slot will be _destroyed_. Finally the device
60 * is resumed.
61 *
62 * DM_DEV_STATUS:
63 * Retrieves the status for the table in the 'active' slot.
64 *
65 * DM_DEV_WAIT:
66 * Wait for a significant event to occur to the device. This
67 * could either be caused by an event triggered by one of the
68 * targets of the table in the 'active' slot, or a table change.
69 *
70 * DM_TABLE_LOAD:
71 * Load a table into the 'inactive' slot for the device. The
72 * device does _not_ need to be suspended prior to this command.
73 *
74 * DM_TABLE_CLEAR:
75 * Destroy any table in the 'inactive' slot (ie. abort).
76 *
77 * DM_TABLE_DEPS:
78 * Return a set of device dependencies for the 'active' table.
79 *
80 * DM_TABLE_STATUS:
81 * Return the targets status for the 'active' table.
82 *
83 * DM_TARGET_MSG:
84 * Pass a message string to the target at a specific offset of a device.
85 *
86 * DM_DEV_SET_GEOMETRY:
87 * Set the geometry of a device by passing in a string in this format:
88 *
89 * "cylinders heads sectors_per_track start_sector"
90 *
91 * Beware that CHS geometry is nearly obsolete and only provided
92 * for compatibility with dm devices that can be booted by a PC
93 * BIOS. See struct hd_geometry for range limits. Also note that
94 * the geometry is erased if the device size changes.
95 */
96
97 /*
98 * All ioctl arguments consist of a single chunk of memory, with
99 * this structure at the start. If a uuid is specified any
100 * lookup (eg. for a DM_INFO) will be done on that, *not* the
101 * name.
102 */
103 struct dm_ioctl {
104 /*
105 * The version number is made up of three parts:
106 * major - no backward or forward compatibility,
107 * minor - only backwards compatible,
108 * patch - both backwards and forwards compatible.
109 *
110 * All clients of the ioctl interface should fill in the
111 * version number of the interface that they were
112 * compiled with.
113 *
114 * All recognised ioctl commands (ie. those that don't
115 * return -ENOTTY) fill out this field, even if the
116 * command failed.
117 */
118 __u32 version[3]; /* in/out */
119 __u32 data_size; /* total size of data passed in
120 * including this struct */
121
122 __u32 data_start; /* offset to start of data
123 * relative to start of this struct */
124
125 __u32 target_count; /* in/out */
126 __s32 open_count; /* out */
127 __u32 flags; /* in/out */
128
129 /*
130 * event_nr holds either the event number (input and output) or the
131 * udev cookie value (input only).
132 * The DM_DEV_WAIT ioctl takes an event number as input.
133 * The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls
134 * use the field as a cookie to return in the DM_COOKIE
135 * variable with the uevents they issue.
136 * For output, the ioctls return the event number, not the cookie.
137 */
138 __u32 event_nr; /* in/out */
139 __u32 padding;
140
141 __u64 dev; /* in/out */
142
143 char name[DM_NAME_LEN]; /* device name */
144 char uuid[DM_UUID_LEN]; /* unique identifier for
145 * the block device */
146 char data[7]; /* padding or data */
147 };
148
149 /*
150 * Used to specify tables. These structures appear after the
151 * dm_ioctl.
152 */
153 struct dm_target_spec {
154 __u64 sector_start;
155 __u64 length;
156 __s32 status; /* used when reading from kernel only */
157
158 /*
159 * Location of the next dm_target_spec.
160 * - When specifying targets on a DM_TABLE_LOAD command, this value is
161 * the number of bytes from the start of the "current" dm_target_spec
162 * to the start of the "next" dm_target_spec.
163 * - When retrieving targets on a DM_TABLE_STATUS command, this value
164 * is the number of bytes from the start of the first dm_target_spec
165 * (that follows the dm_ioctl struct) to the start of the "next"
166 * dm_target_spec.
167 */
168 __u32 next;
169
170 char target_type[DM_MAX_TYPE_NAME];
171
172 /*
173 * Parameter string starts immediately after this object.
174 * Be careful to add padding after string to ensure correct
175 * alignment of subsequent dm_target_spec.
176 */
177 };
178
179 /*
180 * Used to retrieve the target dependencies.
181 */
182 struct dm_target_deps {
183 __u32 count; /* Array size */
184 __u32 padding; /* unused */
185 __u64 dev[0]; /* out */
186 };
187
188 /*
189 * Used to get a list of all dm devices.
190 */
191 struct dm_name_list {
192 __u64 dev;
193 __u32 next; /* offset to the next record from
194 the _start_ of this */
195 char name[0];
196 };
197
198 /*
199 * Used to retrieve the target versions
200 */
201 struct dm_target_versions {
202 __u32 next;
203 __u32 version[3];
204
205 char name[0];
206 };
207
208 /*
209 * Used to pass message to a target
210 */
211 struct dm_target_msg {
212 __u64 sector; /* Device sector */
213
214 char message[0];
215 };
216
217 /*
218 * If you change this make sure you make the corresponding change
219 * to dm-ioctl.c:lookup_ioctl()
220 */
221 enum {
222 /* Top level cmds */
223 DM_VERSION_CMD = 0,
224 DM_REMOVE_ALL_CMD,
225 DM_LIST_DEVICES_CMD,
226
227 /* device level cmds */
228 DM_DEV_CREATE_CMD,
229 DM_DEV_REMOVE_CMD,
230 DM_DEV_RENAME_CMD,
231 DM_DEV_SUSPEND_CMD,
232 DM_DEV_STATUS_CMD,
233 DM_DEV_WAIT_CMD,
234
235 /* Table level cmds */
236 DM_TABLE_LOAD_CMD,
237 DM_TABLE_CLEAR_CMD,
238 DM_TABLE_DEPS_CMD,
239 DM_TABLE_STATUS_CMD,
240
241 /* Added later */
242 DM_LIST_VERSIONS_CMD,
243 DM_TARGET_MSG_CMD,
244 DM_DEV_SET_GEOMETRY_CMD,
245 DM_DEV_ARM_POLL_CMD,
246 DM_GET_TARGET_VERSION_CMD,
247 };
248
249 #define DM_IOCTL 0xfd
250
251 #define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
252 #define DM_REMOVE_ALL _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
253 #define DM_LIST_DEVICES _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
254
255 #define DM_DEV_CREATE _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
256 #define DM_DEV_REMOVE _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
257 #define DM_DEV_RENAME _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
258 #define DM_DEV_SUSPEND _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
259 #define DM_DEV_STATUS _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
260 #define DM_DEV_WAIT _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
261 #define DM_DEV_ARM_POLL _IOWR(DM_IOCTL, DM_DEV_ARM_POLL_CMD, struct dm_ioctl)
262
263 #define DM_TABLE_LOAD _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
264 #define DM_TABLE_CLEAR _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
265 #define DM_TABLE_DEPS _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
266 #define DM_TABLE_STATUS _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
267
268 #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
269 #define DM_GET_TARGET_VERSION _IOWR(DM_IOCTL, DM_GET_TARGET_VERSION_CMD, struct dm_ioctl)
270
271 #define DM_TARGET_MSG _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
272 #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
273
274 #define DM_VERSION_MAJOR 4
275 #define DM_VERSION_MINOR 41
276 #define DM_VERSION_PATCHLEVEL 0
277 #define DM_VERSION_EXTRA "-ioctl (2019-09-16)"
278
279 /* Status bits */
280 #define DM_READONLY_FLAG (1 << 0) /* In/Out */
281 #define DM_SUSPEND_FLAG (1 << 1) /* In/Out */
282 #define DM_PERSISTENT_DEV_FLAG (1 << 3) /* In */
283
284 /*
285 * Flag passed into ioctl STATUS command to get table information
286 * rather than current status.
287 */
288 #define DM_STATUS_TABLE_FLAG (1 << 4) /* In */
289
290 /*
291 * Flags that indicate whether a table is present in either of
292 * the two table slots that a device has.
293 */
294 #define DM_ACTIVE_PRESENT_FLAG (1 << 5) /* Out */
295 #define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
296
297 /*
298 * Indicates that the buffer passed in wasn't big enough for the
299 * results.
300 */
301 #define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */
302
303 /*
304 * This flag is now ignored.
305 */
306 #define DM_SKIP_BDGET_FLAG (1 << 9) /* In */
307
308 /*
309 * Set this to avoid attempting to freeze any filesystem when suspending.
310 */
311 #define DM_SKIP_LOCKFS_FLAG (1 << 10) /* In */
312
313 /*
314 * Set this to suspend without flushing queued ios.
315 * Also disables flushing uncommitted changes in the thin target before
316 * generating statistics for DM_TABLE_STATUS and DM_DEV_WAIT.
317 */
318 #define DM_NOFLUSH_FLAG (1 << 11) /* In */
319
320 /*
321 * If set, any table information returned will relate to the inactive
322 * table instead of the live one. Always check DM_INACTIVE_PRESENT_FLAG
323 * is set before using the data returned.
324 */
325 #define DM_QUERY_INACTIVE_TABLE_FLAG (1 << 12) /* In */
326
327 /*
328 * If set, a uevent was generated for which the caller may need to wait.
329 */
330 #define DM_UEVENT_GENERATED_FLAG (1 << 13) /* Out */
331
332 /*
333 * If set, rename changes the uuid not the name. Only permitted
334 * if no uuid was previously supplied: an existing uuid cannot be changed.
335 */
336 #define DM_UUID_FLAG (1 << 14) /* In */
337
338 /*
339 * If set, all buffers are wiped after use. Use when sending
340 * or requesting sensitive data such as an encryption key.
341 */
342 #define DM_SECURE_DATA_FLAG (1 << 15) /* In */
343
344 /*
345 * If set, a message generated output data.
346 */
347 #define DM_DATA_OUT_FLAG (1 << 16) /* Out */
348
349 /*
350 * If set with DM_DEV_REMOVE or DM_REMOVE_ALL this indicates that if
351 * the device cannot be removed immediately because it is still in use
352 * it should instead be scheduled for removal when it gets closed.
353 *
354 * On return from DM_DEV_REMOVE, DM_DEV_STATUS or other ioctls, this
355 * flag indicates that the device is scheduled to be removed when it
356 * gets closed.
357 */
358 #define DM_DEFERRED_REMOVE (1 << 17) /* In/Out */
359
360 /*
361 * If set, the device is suspended internally.
362 */
363 #define DM_INTERNAL_SUSPEND_FLAG (1 << 18) /* Out */
364
365 #endif /* _LINUX_DM_IOCTL_H */