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 */
103struct 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 */
153struct 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 */
182struct dm_target_deps {
183 __u32 count; /* Array size */
184 __u32 padding; /* unused */
185 __u64 dev[]; /* out */
186};
187
188/*
189 * Used to get a list of all dm devices.
190 */
191struct dm_name_list {
192 __u64 dev;
193 __u32 next; /* offset to the next record from
194 the _start_ of this */
195 char name[];
196
197 /*
198 * The following members can be accessed by taking a pointer that
199 * points immediately after the terminating zero character in "name"
200 * and aligning this pointer to next 8-byte boundary.
201 * Uuid is present if the flag DM_NAME_LIST_FLAG_HAS_UUID is set.
202 *
203 * __u32 event_nr;
204 * __u32 flags;
205 * char uuid[0];
206 */
207};
208
209#define DM_NAME_LIST_FLAG_HAS_UUID 1
210#define DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID 2
211
212/*
213 * Used to retrieve the target versions
214 */
215struct dm_target_versions {
216 __u32 next;
217 __u32 version[3];
218
219 char name[];
220};
221
222/*
223 * Used to pass message to a target
224 */
225struct dm_target_msg {
226 __u64 sector; /* Device sector */
227
228 char message[];
229};
230
231/*
232 * If you change this make sure you make the corresponding change
233 * to dm-ioctl.c:lookup_ioctl()
234 */
235enum {
236 /* Top level cmds */
237 DM_VERSION_CMD = 0,
238 DM_REMOVE_ALL_CMD,
239 DM_LIST_DEVICES_CMD,
240
241 /* device level cmds */
242 DM_DEV_CREATE_CMD,
243 DM_DEV_REMOVE_CMD,
244 DM_DEV_RENAME_CMD,
245 DM_DEV_SUSPEND_CMD,
246 DM_DEV_STATUS_CMD,
247 DM_DEV_WAIT_CMD,
248
249 /* Table level cmds */
250 DM_TABLE_LOAD_CMD,
251 DM_TABLE_CLEAR_CMD,
252 DM_TABLE_DEPS_CMD,
253 DM_TABLE_STATUS_CMD,
254
255 /* Added later */
256 DM_LIST_VERSIONS_CMD,
257 DM_TARGET_MSG_CMD,
258 DM_DEV_SET_GEOMETRY_CMD,
259 DM_DEV_ARM_POLL_CMD,
260 DM_GET_TARGET_VERSION_CMD,
261};
262
263#define DM_IOCTL 0xfd
264
265#define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
266#define DM_REMOVE_ALL _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
267#define DM_LIST_DEVICES _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
268
269#define DM_DEV_CREATE _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
270#define DM_DEV_REMOVE _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
271#define DM_DEV_RENAME _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
272#define DM_DEV_SUSPEND _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
273#define DM_DEV_STATUS _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
274#define DM_DEV_WAIT _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
275#define DM_DEV_ARM_POLL _IOWR(DM_IOCTL, DM_DEV_ARM_POLL_CMD, struct dm_ioctl)
276
277#define DM_TABLE_LOAD _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
278#define DM_TABLE_CLEAR _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
279#define DM_TABLE_DEPS _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
280#define DM_TABLE_STATUS _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
281
282#define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
283#define DM_GET_TARGET_VERSION _IOWR(DM_IOCTL, DM_GET_TARGET_VERSION_CMD, struct dm_ioctl)
284
285#define DM_TARGET_MSG _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
286#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
287
288#define DM_VERSION_MAJOR 4
289#define DM_VERSION_MINOR 47
290#define DM_VERSION_PATCHLEVEL 0
291#define DM_VERSION_EXTRA "-ioctl (2022-07-28)"
292
293/* Status bits */
294#define DM_READONLY_FLAG (1 << 0) /* In/Out */
295#define DM_SUSPEND_FLAG (1 << 1) /* In/Out */
296#define DM_PERSISTENT_DEV_FLAG (1 << 3) /* In */
297
298/*
299 * Flag passed into ioctl STATUS command to get table information
300 * rather than current status.
301 */
302#define DM_STATUS_TABLE_FLAG (1 << 4) /* In */
303
304/*
305 * Flags that indicate whether a table is present in either of
306 * the two table slots that a device has.
307 */
308#define DM_ACTIVE_PRESENT_FLAG (1 << 5) /* Out */
309#define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
310
311/*
312 * Indicates that the buffer passed in wasn't big enough for the
313 * results.
314 */
315#define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */
316
317/*
318 * This flag is now ignored.
319 */
320#define DM_SKIP_BDGET_FLAG (1 << 9) /* In */
321
322/*
323 * Set this to avoid attempting to freeze any filesystem when suspending.
324 */
325#define DM_SKIP_LOCKFS_FLAG (1 << 10) /* In */
326
327/*
328 * Set this to suspend without flushing queued ios.
329 * Also disables flushing uncommitted changes in the thin target before
330 * generating statistics for DM_TABLE_STATUS and DM_DEV_WAIT.
331 */
332#define DM_NOFLUSH_FLAG (1 << 11) /* In */
333
334/*
335 * If set, any table information returned will relate to the inactive
336 * table instead of the live one. Always check DM_INACTIVE_PRESENT_FLAG
337 * is set before using the data returned.
338 */
339#define DM_QUERY_INACTIVE_TABLE_FLAG (1 << 12) /* In */
340
341/*
342 * If set, a uevent was generated for which the caller may need to wait.
343 */
344#define DM_UEVENT_GENERATED_FLAG (1 << 13) /* Out */
345
346/*
347 * If set, rename changes the uuid not the name. Only permitted
348 * if no uuid was previously supplied: an existing uuid cannot be changed.
349 */
350#define DM_UUID_FLAG (1 << 14) /* In */
351
352/*
353 * If set, all buffers are wiped after use. Use when sending
354 * or requesting sensitive data such as an encryption key.
355 */
356#define DM_SECURE_DATA_FLAG (1 << 15) /* In */
357
358/*
359 * If set, a message generated output data.
360 */
361#define DM_DATA_OUT_FLAG (1 << 16) /* Out */
362
363/*
364 * If set with DM_DEV_REMOVE or DM_REMOVE_ALL this indicates that if
365 * the device cannot be removed immediately because it is still in use
366 * it should instead be scheduled for removal when it gets closed.
367 *
368 * On return from DM_DEV_REMOVE, DM_DEV_STATUS or other ioctls, this
369 * flag indicates that the device is scheduled to be removed when it
370 * gets closed.
371 */
372#define DM_DEFERRED_REMOVE (1 << 17) /* In/Out */
373
374/*
375 * If set, the device is suspended internally.
376 */
377#define DM_INTERNAL_SUSPEND_FLAG (1 << 18) /* Out */
378
379/*
380 * If set, returns in the in buffer passed by UM, the raw table information
381 * that would be measured by IMA subsystem on device state change.
382 */
383#define DM_IMA_MEASUREMENT_FLAG (1 << 19) /* In */
384
385#endif /* _LINUX_DM_IOCTL_H */
386

source code of linux/include/uapi/linux/dm-ioctl.h