1/* $NetBSD: dm-ioctl.h,v 1.1.1.2 2009/12/02 00:26:09 haad Exp $ */
2
3/*
4 * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
5 * Copyright (C) 2004 - 2009 Red Hat, Inc. All rights reserved.
6 *
7 * This file is released under the LGPL.
8 */
9
10#ifndef _LINUX_DM_IOCTL_V4_H
11#define _LINUX_DM_IOCTL_V4_H
12
13#ifdef linux
14# include <linux/types.h>
15#endif
16
17#define DM_DIR "mapper" /* Slashes not supported */
18#define DM_MAX_TYPE_NAME 16
19#define DM_NAME_LEN 128
20#define DM_UUID_LEN 129
21
22/*
23 * A traditional ioctl interface for the device mapper.
24 *
25 * Each device can have two tables associated with it, an
26 * 'active' table which is the one currently used by io passing
27 * through the device, and an 'inactive' one which is a table
28 * that is being prepared as a replacement for the 'active' one.
29 *
30 * DM_VERSION:
31 * Just get the version information for the ioctl interface.
32 *
33 * DM_REMOVE_ALL:
34 * Remove all dm devices, destroy all tables. Only really used
35 * for debug.
36 *
37 * DM_LIST_DEVICES:
38 * Get a list of all the dm device names.
39 *
40 * DM_DEV_CREATE:
41 * Create a new device, neither the 'active' or 'inactive' table
42 * slots will be filled. The device will be in suspended state
43 * after creation, however any io to the device will get errored
44 * since it will be out-of-bounds.
45 *
46 * DM_DEV_REMOVE:
47 * Remove a device, destroy any tables.
48 *
49 * DM_DEV_RENAME:
50 * Rename a device.
51 *
52 * DM_SUSPEND:
53 * This performs both suspend and resume, depending which flag is
54 * passed in.
55 * Suspend: This command will not return until all pending io to
56 * the device has completed. Further io will be deferred until
57 * the device is resumed.
58 * Resume: It is no longer an error to issue this command on an
59 * unsuspended device. If a table is present in the 'inactive'
60 * slot, it will be moved to the active slot, then the old table
61 * from the active slot will be _destroyed_. Finally the device
62 * is resumed.
63 *
64 * DM_DEV_STATUS:
65 * Retrieves the status for the table in the 'active' slot.
66 *
67 * DM_DEV_WAIT:
68 * Wait for a significant event to occur to the device. This
69 * could either be caused by an event triggered by one of the
70 * targets of the table in the 'active' slot, or a table change.
71 *
72 * DM_TABLE_LOAD:
73 * Load a table into the 'inactive' slot for the device. The
74 * device does _not_ need to be suspended prior to this command.
75 *
76 * DM_TABLE_CLEAR:
77 * Destroy any table in the 'inactive' slot (ie. abort).
78 *
79 * DM_TABLE_DEPS:
80 * Return a set of device dependencies for the 'active' table.
81 *
82 * DM_TABLE_STATUS:
83 * Return the targets status for the 'active' table.
84 *
85 * DM_TARGET_MSG:
86 * Pass a message string to the target at a specific offset of a device.
87 *
88 * DM_DEV_SET_GEOMETRY:
89 * Set the geometry of a device by passing in a string in this format:
90 *
91 * "cylinders heads sectors_per_track start_sector"
92 *
93 * Beware that CHS geometry is nearly obsolete and only provided
94 * for compatibility with dm devices that can be booted by a PC
95 * BIOS. See struct hd_geometry for range limits. Also note that
96 * the geometry is erased if the device size changes.
97 */
98
99/*
100 * All ioctl arguments consist of a single chunk of memory, with
101 * this structure at the start. If a uuid is specified any
102 * lookup (eg. for a DM_INFO) will be done on that, *not* the
103 * name.
104 */
105struct dm_ioctl {
106 /*
107 * The version number is made up of three parts:
108 * major - no backward or forward compatibility,
109 * minor - only backwards compatible,
110 * patch - both backwards and forwards compatible.
111 *
112 * All clients of the ioctl interface should fill in the
113 * version number of the interface that they were
114 * compiled with.
115 *
116 * All recognised ioctl commands (ie. those that don't
117 * return -ENOTTY) fill out this field, even if the
118 * command failed.
119 */
120 uint32_t version[3]; /* in/out */
121 uint32_t data_size; /* total size of data passed in
122 * including this struct */
123
124 uint32_t data_start; /* offset to start of data
125 * relative to start of this struct */
126
127 uint32_t target_count; /* in/out */
128 int32_t open_count; /* out */
129 uint32_t flags; /* in/out */
130
131 /*
132 * event_nr holds either the event number (input and output) or the
133 * udev cookie value (input only).
134 * The DM_DEV_WAIT ioctl takes an event number as input.
135 * The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls
136 * use the field as a cookie to return in the DM_COOKIE
137 * variable with the uevents they issue.
138 * For output, the ioctls return the event number, not the cookie.
139 */
140 uint32_t event_nr; /* in/out */
141 uint32_t padding;
142
143 uint64_t dev; /* in/out */
144
145 char name[DM_NAME_LEN]; /* device name */
146 char uuid[DM_UUID_LEN]; /* unique identifier for
147 * the block device */
148 char data[7]; /* padding or data */
149};
150
151/*
152 * Used to specify tables. These structures appear after the
153 * dm_ioctl.
154 */
155struct dm_target_spec {
156 uint64_t sector_start;
157 uint64_t length;
158 int32_t status; /* used when reading from kernel only */
159
160 /*
161 * Location of the next dm_target_spec.
162 * - When specifying targets on a DM_TABLE_LOAD command, this value is
163 * the number of bytes from the start of the "current" dm_target_spec
164 * to the start of the "next" dm_target_spec.
165 * - When retrieving targets on a DM_TABLE_STATUS command, this value
166 * is the number of bytes from the start of the first dm_target_spec
167 * (that follows the dm_ioctl struct) to the start of the "next"
168 * dm_target_spec.
169 */
170 uint32_t next;
171
172 char target_type[DM_MAX_TYPE_NAME];
173
174 /*
175 * Parameter string starts immediately after this object.
176 * Be careful to add padding after string to ensure correct
177 * alignment of subsequent dm_target_spec.
178 */
179};
180
181/*
182 * Used to retrieve the target dependencies.
183 */
184struct dm_target_deps {
185 uint32_t count; /* Array size */
186 uint32_t padding; /* unused */
187 uint64_t dev[0]; /* out */
188};
189
190/*
191 * Used to get a list of all dm devices.
192 */
193struct dm_name_list {
194 uint64_t dev;
195 uint32_t next; /* offset to the next record from
196 the _start_ of this */
197 char name[0];
198};
199
200/*
201 * Used to retrieve the target versions
202 */
203struct dm_target_versions {
204 uint32_t next;
205 uint32_t version[3];
206
207 char name[0];
208};
209
210/*
211 * Used to pass message to a target
212 */
213struct dm_target_msg {
214 uint64_t sector; /* Device sector */
215
216 char message[0];
217};
218
219/*
220 * If you change this make sure you make the corresponding change
221 * to dm-ioctl.c:lookup_ioctl()
222 */
223enum {
224 /* Top level cmds */
225 DM_VERSION_CMD = 0,
226 DM_REMOVE_ALL_CMD,
227 DM_LIST_DEVICES_CMD,
228
229 /* device level cmds */
230 DM_DEV_CREATE_CMD,
231 DM_DEV_REMOVE_CMD,
232 DM_DEV_RENAME_CMD,
233 DM_DEV_SUSPEND_CMD,
234 DM_DEV_STATUS_CMD,
235 DM_DEV_WAIT_CMD,
236
237 /* Table level cmds */
238 DM_TABLE_LOAD_CMD,
239 DM_TABLE_CLEAR_CMD,
240 DM_TABLE_DEPS_CMD,
241 DM_TABLE_STATUS_CMD,
242
243 /* Added later */
244 DM_LIST_VERSIONS_CMD,
245 DM_TARGET_MSG_CMD,
246 DM_DEV_SET_GEOMETRY_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
262#define DM_TABLE_LOAD _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
263#define DM_TABLE_CLEAR _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
264#define DM_TABLE_DEPS _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
265#define DM_TABLE_STATUS _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
266
267#define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
268
269#define DM_TARGET_MSG _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
270#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
271
272#define DM_VERSION_MAJOR 4
273#define DM_VERSION_MINOR 16
274#define DM_VERSION_PATCHLEVEL 0
275#define DM_VERSION_EXTRA "-ioctl (2009-11-05)"
276
277/* Status bits */
278#define DM_READONLY_FLAG (1 << 0) /* In/Out */
279#define DM_SUSPEND_FLAG (1 << 1) /* In/Out */
280#define DM_PERSISTENT_DEV_FLAG (1 << 3) /* In */
281
282/*
283 * Flag passed into ioctl STATUS command to get table information
284 * rather than current status.
285 */
286#define DM_STATUS_TABLE_FLAG (1 << 4) /* In */
287
288/*
289 * Flags that indicate whether a table is present in either of
290 * the two table slots that a device has.
291 */
292#define DM_ACTIVE_PRESENT_FLAG (1 << 5) /* Out */
293#define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
294
295/*
296 * Indicates that the buffer passed in wasn't big enough for the
297 * results.
298 */
299#define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */
300
301/*
302 * This flag is now ignored.
303 */
304#define DM_SKIP_BDGET_FLAG (1 << 9) /* In */
305
306/*
307 * Set this to avoid attempting to freeze any filesystem when suspending.
308 */
309#define DM_SKIP_LOCKFS_FLAG (1 << 10) /* In */
310
311/*
312 * Set this to suspend without flushing queued ios.
313 */
314#define DM_NOFLUSH_FLAG (1 << 11) /* In */
315
316/*
317 * If set, any table information returned will relate to the inactive
318 * table instead of the live one. Always check DM_INACTIVE_PRESENT_FLAG
319 * is set before using the data returned.
320 */
321#define DM_QUERY_INACTIVE_TABLE_FLAG (1 << 12) /* In */
322
323#endif /* _LINUX_DM_IOCTL_H */
324