Merge branch 'docs-next' of git://git.lwn.net/linux-2.6
[linux-2.6/next.git] / include / linux / dm-ioctl.h
blob2ab84c83c31a9d7d11b8c18ee744cb85ca520fd8
1 /*
2 * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved.
5 * This file is released under the LGPL.
6 */
8 #ifndef _LINUX_DM_IOCTL_V4_H
9 #define _LINUX_DM_IOCTL_V4_H
11 #include <linux/types.h>
13 #define DM_DIR "mapper" /* Slashes not supported */
14 #define DM_MAX_TYPE_NAME 16
15 #define DM_NAME_LEN 128
16 #define DM_UUID_LEN 129
19 * A traditional ioctl interface for the device mapper.
21 * Each device can have two tables associated with it, an
22 * 'active' table which is the one currently used by io passing
23 * through the device, and an 'inactive' one which is a table
24 * that is being prepared as a replacement for the 'active' one.
26 * DM_VERSION:
27 * Just get the version information for the ioctl interface.
29 * DM_REMOVE_ALL:
30 * Remove all dm devices, destroy all tables. Only really used
31 * for debug.
33 * DM_LIST_DEVICES:
34 * Get a list of all the dm device names.
36 * DM_DEV_CREATE:
37 * Create a new device, neither the 'active' or 'inactive' table
38 * slots will be filled. The device will be in suspended state
39 * after creation, however any io to the device will get errored
40 * since it will be out-of-bounds.
42 * DM_DEV_REMOVE:
43 * Remove a device, destroy any tables.
45 * DM_DEV_RENAME:
46 * Rename a device.
48 * DM_SUSPEND:
49 * This performs both suspend and resume, depending which flag is
50 * passed in.
51 * Suspend: This command will not return until all pending io to
52 * the device has completed. Further io will be deferred until
53 * the device is resumed.
54 * Resume: It is no longer an error to issue this command on an
55 * unsuspended device. If a table is present in the 'inactive'
56 * slot, it will be moved to the active slot, then the old table
57 * from the active slot will be _destroyed_. Finally the device
58 * is resumed.
60 * DM_DEV_STATUS:
61 * Retrieves the status for the table in the 'active' slot.
63 * DM_DEV_WAIT:
64 * Wait for a significant event to occur to the device. This
65 * could either be caused by an event triggered by one of the
66 * targets of the table in the 'active' slot, or a table change.
68 * DM_TABLE_LOAD:
69 * Load a table into the 'inactive' slot for the device. The
70 * device does _not_ need to be suspended prior to this command.
72 * DM_TABLE_CLEAR:
73 * Destroy any table in the 'inactive' slot (ie. abort).
75 * DM_TABLE_DEPS:
76 * Return a set of device dependencies for the 'active' table.
78 * DM_TABLE_STATUS:
79 * Return the targets status for the 'active' table.
81 * DM_TARGET_MSG:
82 * Pass a message string to the target at a specific offset of a device.
84 * DM_DEV_SET_GEOMETRY:
85 * Set the geometry of a device by passing in a string in this format:
87 * "cylinders heads sectors_per_track start_sector"
89 * Beware that CHS geometry is nearly obsolete and only provided
90 * for compatibility with dm devices that can be booted by a PC
91 * BIOS. See struct hd_geometry for range limits. Also note that
92 * the geometry is erased if the device size changes.
96 * All ioctl arguments consist of a single chunk of memory, with
97 * this structure at the start. If a uuid is specified any
98 * lookup (eg. for a DM_INFO) will be done on that, *not* the
99 * name.
101 struct dm_ioctl {
103 * The version number is made up of three parts:
104 * major - no backward or forward compatibility,
105 * minor - only backwards compatible,
106 * patch - both backwards and forwards compatible.
108 * All clients of the ioctl interface should fill in the
109 * version number of the interface that they were
110 * compiled with.
112 * All recognised ioctl commands (ie. those that don't
113 * return -ENOTTY) fill out this field, even if the
114 * command failed.
116 __u32 version[3]; /* in/out */
117 __u32 data_size; /* total size of data passed in
118 * including this struct */
120 __u32 data_start; /* offset to start of data
121 * relative to start of this struct */
123 __u32 target_count; /* in/out */
124 __s32 open_count; /* out */
125 __u32 flags; /* in/out */
128 * event_nr holds either the event number (input and output) or the
129 * udev cookie value (input only).
130 * The DM_DEV_WAIT ioctl takes an event number as input.
131 * The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls
132 * use the field as a cookie to return in the DM_COOKIE
133 * variable with the uevents they issue.
134 * For output, the ioctls return the event number, not the cookie.
136 __u32 event_nr; /* in/out */
137 __u32 padding;
139 __u64 dev; /* in/out */
141 char name[DM_NAME_LEN]; /* device name */
142 char uuid[DM_UUID_LEN]; /* unique identifier for
143 * the block device */
144 char data[7]; /* padding or data */
148 * Used to specify tables. These structures appear after the
149 * dm_ioctl.
151 struct dm_target_spec {
152 __u64 sector_start;
153 __u64 length;
154 __s32 status; /* used when reading from kernel only */
157 * Location of the next dm_target_spec.
158 * - When specifying targets on a DM_TABLE_LOAD command, this value is
159 * the number of bytes from the start of the "current" dm_target_spec
160 * to the start of the "next" dm_target_spec.
161 * - When retrieving targets on a DM_TABLE_STATUS command, this value
162 * is the number of bytes from the start of the first dm_target_spec
163 * (that follows the dm_ioctl struct) to the start of the "next"
164 * dm_target_spec.
166 __u32 next;
168 char target_type[DM_MAX_TYPE_NAME];
171 * Parameter string starts immediately after this object.
172 * Be careful to add padding after string to ensure correct
173 * alignment of subsequent dm_target_spec.
178 * Used to retrieve the target dependencies.
180 struct dm_target_deps {
181 __u32 count; /* Array size */
182 __u32 padding; /* unused */
183 __u64 dev[0]; /* out */
187 * Used to get a list of all dm devices.
189 struct dm_name_list {
190 __u64 dev;
191 __u32 next; /* offset to the next record from
192 the _start_ of this */
193 char name[0];
197 * Used to retrieve the target versions
199 struct dm_target_versions {
200 __u32 next;
201 __u32 version[3];
203 char name[0];
207 * Used to pass message to a target
209 struct dm_target_msg {
210 __u64 sector; /* Device sector */
212 char message[0];
216 * If you change this make sure you make the corresponding change
217 * to dm-ioctl.c:lookup_ioctl()
219 enum {
220 /* Top level cmds */
221 DM_VERSION_CMD = 0,
222 DM_REMOVE_ALL_CMD,
223 DM_LIST_DEVICES_CMD,
225 /* device level cmds */
226 DM_DEV_CREATE_CMD,
227 DM_DEV_REMOVE_CMD,
228 DM_DEV_RENAME_CMD,
229 DM_DEV_SUSPEND_CMD,
230 DM_DEV_STATUS_CMD,
231 DM_DEV_WAIT_CMD,
233 /* Table level cmds */
234 DM_TABLE_LOAD_CMD,
235 DM_TABLE_CLEAR_CMD,
236 DM_TABLE_DEPS_CMD,
237 DM_TABLE_STATUS_CMD,
239 /* Added later */
240 DM_LIST_VERSIONS_CMD,
241 DM_TARGET_MSG_CMD,
242 DM_DEV_SET_GEOMETRY_CMD
245 #define DM_IOCTL 0xfd
247 #define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
248 #define DM_REMOVE_ALL _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
249 #define DM_LIST_DEVICES _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
251 #define DM_DEV_CREATE _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
252 #define DM_DEV_REMOVE _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
253 #define DM_DEV_RENAME _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
254 #define DM_DEV_SUSPEND _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
255 #define DM_DEV_STATUS _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
256 #define DM_DEV_WAIT _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
258 #define DM_TABLE_LOAD _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
259 #define DM_TABLE_CLEAR _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
260 #define DM_TABLE_DEPS _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
261 #define DM_TABLE_STATUS _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
263 #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
265 #define DM_TARGET_MSG _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
266 #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
268 #define DM_VERSION_MAJOR 4
269 #define DM_VERSION_MINOR 15
270 #define DM_VERSION_PATCHLEVEL 0
271 #define DM_VERSION_EXTRA "-ioctl (2009-04-01)"
273 /* Status bits */
274 #define DM_READONLY_FLAG (1 << 0) /* In/Out */
275 #define DM_SUSPEND_FLAG (1 << 1) /* In/Out */
276 #define DM_PERSISTENT_DEV_FLAG (1 << 3) /* In */
279 * Flag passed into ioctl STATUS command to get table information
280 * rather than current status.
282 #define DM_STATUS_TABLE_FLAG (1 << 4) /* In */
285 * Flags that indicate whether a table is present in either of
286 * the two table slots that a device has.
288 #define DM_ACTIVE_PRESENT_FLAG (1 << 5) /* Out */
289 #define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
292 * Indicates that the buffer passed in wasn't big enough for the
293 * results.
295 #define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */
298 * This flag is now ignored.
300 #define DM_SKIP_BDGET_FLAG (1 << 9) /* In */
303 * Set this to avoid attempting to freeze any filesystem when suspending.
305 #define DM_SKIP_LOCKFS_FLAG (1 << 10) /* In */
308 * Set this to suspend without flushing queued ios.
310 #define DM_NOFLUSH_FLAG (1 << 11) /* In */
312 #endif /* _LINUX_DM_IOCTL_H */