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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	44
276 #define DM_VERSION_PATCHLEVEL	0
277 #define DM_VERSION_EXTRA	"-ioctl (2021-02-01)"
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 */
366