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 	 * 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  */
215 struct dm_target_versions {
216         __u32 next;
217         __u32 version[3];
218 
219         char name[0];
220 };
221 
222 /*
223  * Used to pass message to a target
224  */
225 struct dm_target_msg {
226 	__u64 sector;	/* Device sector */
227 
228 	char message[0];
229 };
230 
231 /*
232  * If you change this make sure you make the corresponding change
233  * to dm-ioctl.c:lookup_ioctl()
234  */
235 enum {
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