include/linux/dm-ioctl.h

   1 /*
   2  * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
   3  * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved.
   4  *
   5  * This file is released under the LGPL.
   6  */
   7
   8 #ifndef _LINUX_DM_IOCTL_V4_H
   9 #define _LINUX_DM_IOCTL_V4_H
  10
  11 #include <linux/types.h>
  12
  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
  17
  18 /*
  19  * A traditional ioctl interface for the device mapper.
  20  *
  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.
  25  *
  26  * DM_VERSION:
  27  * Just get the version information for the ioctl interface.
  28  *
  29  * DM_REMOVE_ALL:
  30  * Remove all dm devices, destroy all tables.  Only really used
  31  * for debug.
  32  *
  33  * DM_LIST_DEVICES:
  34  * Get a list of all the dm device names.
  35  *
  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.
  41  *
  42  * DM_DEV_REMOVE:
  43  * Remove a device, destroy any tables.
  44  *
  45  * DM_DEV_RENAME:
  46  * Rename a device.
  47  *
  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.
  59  *
  60  * DM_DEV_STATUS:
  61  * Retrieves the status for the table in the 'active' slot.
  62  *
  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.
  67  *
  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.
  71  *
  72  * DM_TABLE_CLEAR:
  73  * Destroy any table in the 'inactive' slot (ie. abort).
  74  *
  75  * DM_TABLE_DEPS:
  76  * Return a set of device dependencies for the 'active' table.
  77  *
  78  * DM_TABLE_STATUS:
  79  * Return the targets status for the 'active' table.
  80  *
  81  * DM_TARGET_MSG:
  82  * Pass a message string to the target at a specific offset of a device.
  83  *
  84  * DM_DEV_SET_GEOMETRY:
  85  * Set the geometry of a device by passing in a string in this format:
  86  *
  87  * "cylinders heads sectors_per_track start_sector"
  88  *
  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.
  93  */
  94
  95 /*
  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.
 100  */
 101 struct dm_ioctl {
 102         /*
 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.
 107          *
 108          * All clients of the ioctl interface should fill in the
 109          * version number of the interface that they were
 110          * compiled with.
 111          *
 112          * All recognised ioctl commands (ie. those that don't
 113          * return -ENOTTY) fill out this field, even if the
 114          * command failed.
 115          */
 116         uint32_t version[3];    /* in/out */
 117         uint32_t data_size;     /* total size of data passed in
 118                                  * including this struct */
 119
 120         uint32_t data_start;    /* offset to start of data
 121                                  * relative to start of this struct */
 122
 123         uint32_t target_count;  /* in/out */
 124         int32_t open_count;     /* out */
 125         uint32_t flags;         /* in/out */
 126         uint32_t event_nr;              /* in/out */
 127         uint32_t padding;
 128
 129         uint64_t dev;           /* in/out */
 130
 131         char name[DM_NAME_LEN]; /* device name */
 132         char uuid[DM_UUID_LEN]; /* unique identifier for
 133                                  * the block device */
 134 };
 135
 136 /*
 137  * Used to specify tables.  These structures appear after the
 138  * dm_ioctl.
 139  */
 140 struct dm_target_spec {
 141         uint64_t sector_start;
 142         uint64_t length;
 143         int32_t status;         /* used when reading from kernel only */
 144
 145         /*
 146          * Location of the next dm_target_spec.
 147          * - When specifying targets on a DM_TABLE_LOAD command, this value is
 148          *   the number of bytes from the start of the "current" dm_target_spec
 149          *   to the start of the "next" dm_target_spec.
 150          * - When retrieving targets on a DM_TABLE_STATUS command, this value
 151          *   is the number of bytes from the start of the first dm_target_spec
 152          *   (that follows the dm_ioctl struct) to the start of the "next"
 153          *   dm_target_spec.
 154          */
 155         uint32_t next;
 156
 157         char target_type[DM_MAX_TYPE_NAME];
 158
 159         /*
 160          * Parameter string starts immediately after this object.
 161          * Be careful to add padding after string to ensure correct
 162          * alignment of subsequent dm_target_spec.
 163          */
 164 };
 165
 166 /*
 167  * Used to retrieve the target dependencies.
 168  */
 169 struct dm_target_deps {
 170         uint32_t count; /* Array size */
 171         uint32_t padding;       /* unused */
 172         uint64_t dev[0];        /* out */
 173 };
 174
 175 /*
 176  * Used to get a list of all dm devices.
 177  */
 178 struct dm_name_list {
 179         uint64_t dev;
 180         uint32_t next;          /* offset to the next record from
 181                                    the _start_ of this */
 182         char name[0];
 183 };
 184
 185 /*
 186  * Used to retrieve the target versions
 187  */
 188 struct dm_target_versions {
 189         uint32_t next;
 190         uint32_t version[3];
 191
 192         char name[0];
 193 };
 194
 195 /*
 196  * Used to pass message to a target
 197  */
 198 struct dm_target_msg {
 199         uint64_t sector;        /* Device sector */
 200
 201         char message[0];
 202 };
 203
 204 /*
 205  * If you change this make sure you make the corresponding change
 206  * to dm-ioctl.c:lookup_ioctl()
 207  */
 208 enum {
 209         /* Top level cmds */
 210         DM_VERSION_CMD = 0,
 211         DM_REMOVE_ALL_CMD,
 212         DM_LIST_DEVICES_CMD,
 213
 214         /* device level cmds */
 215         DM_DEV_CREATE_CMD,
 216         DM_DEV_REMOVE_CMD,
 217         DM_DEV_RENAME_CMD,
 218         DM_DEV_SUSPEND_CMD,
 219         DM_DEV_STATUS_CMD,
 220         DM_DEV_WAIT_CMD,
 221
 222         /* Table level cmds */
 223         DM_TABLE_LOAD_CMD,
 224         DM_TABLE_CLEAR_CMD,
 225         DM_TABLE_DEPS_CMD,
 226         DM_TABLE_STATUS_CMD,
 227
 228         /* Added later */
 229         DM_LIST_VERSIONS_CMD,
 230         DM_TARGET_MSG_CMD,
 231         DM_DEV_SET_GEOMETRY_CMD
 232 };
 233
 234 /*
 235  * The dm_ioctl struct passed into the ioctl is just the header
 236  * on a larger chunk of memory.  On x86-64 and other
 237  * architectures the dm-ioctl struct will be padded to an 8 byte
 238  * boundary so the size will be different, which would change the
 239  * ioctl code - yes I really messed up.  This hack forces these
 240  * architectures to have the correct ioctl code.
 241  */
 242 #ifdef CONFIG_COMPAT
 243 typedef char ioctl_struct[308];
 244 #define DM_VERSION_32       _IOWR(DM_IOCTL, DM_VERSION_CMD, ioctl_struct)
 245 #define DM_REMOVE_ALL_32    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, ioctl_struct)
 246 #define DM_LIST_DEVICES_32  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, ioctl_struct)
 247
 248 #define DM_DEV_CREATE_32    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, ioctl_struct)
 249 #define DM_DEV_REMOVE_32    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, ioctl_struct)
 250 #define DM_DEV_RENAME_32    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, ioctl_struct)
 251 #define DM_DEV_SUSPEND_32   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, ioctl_struct)
 252 #define DM_DEV_STATUS_32    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, ioctl_struct)
 253 #define DM_DEV_WAIT_32      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, ioctl_struct)
 254
 255 #define DM_TABLE_LOAD_32    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, ioctl_struct)
 256 #define DM_TABLE_CLEAR_32   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, ioctl_struct)
 257 #define DM_TABLE_DEPS_32    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, ioctl_struct)
 258 #define DM_TABLE_STATUS_32  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, ioctl_struct)
 259 #define DM_LIST_VERSIONS_32 _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, ioctl_struct)
 260 #define DM_TARGET_MSG_32    _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, ioctl_struct)
 261 #define DM_DEV_SET_GEOMETRY_32  _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, ioctl_struct)
 262 #endif
 263
 264 #define DM_IOCTL 0xfd
 265
 266 #define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
 267 #define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
 268 #define DM_LIST_DEVICES  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
 269
 270 #define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
 271 #define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
 272 #define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
 273 #define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
 274 #define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
 275 #define DM_DEV_WAIT      _IOWR(DM_IOCTL, DM_DEV_WAIT_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
 284 #define DM_TARGET_MSG    _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
 285 #define DM_DEV_SET_GEOMETRY     _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 286
 287 #define DM_VERSION_MAJOR        4
 288 #define DM_VERSION_MINOR        6
 289 #define DM_VERSION_PATCHLEVEL   0
 290 #define DM_VERSION_EXTRA        "-ioctl (2006-02-17)"
 291
 292 /* Status bits */
 293 #define DM_READONLY_FLAG        (1 << 0) /* In/Out */
 294 #define DM_SUSPEND_FLAG         (1 << 1) /* In/Out */
 295 #define DM_PERSISTENT_DEV_FLAG  (1 << 3) /* In */
 296
 297 /*
 298  * Flag passed into ioctl STATUS command to get table information
 299  * rather than current status.
 300  */
 301 #define DM_STATUS_TABLE_FLAG    (1 << 4) /* In */
 302
 303 /*
 304  * Flags that indicate whether a table is present in either of
 305  * the two table slots that a device has.
 306  */
 307 #define DM_ACTIVE_PRESENT_FLAG   (1 << 5) /* Out */
 308 #define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
 309
 310 /*
 311  * Indicates that the buffer passed in wasn't big enough for the
 312  * results.
 313  */
 314 #define DM_BUFFER_FULL_FLAG     (1 << 8) /* Out */
 315
 316 /*
 317  * Set this to improve performance when you aren't going to use open_count.
 318  */
 319 #define DM_SKIP_BDGET_FLAG      (1 << 9) /* In */
 320
 321 /*
 322  * Set this to avoid attempting to freeze any filesystem when suspending.
 323  */
 324 #define DM_SKIP_LOCKFS_FLAG     (1 << 10) /* In */
 325
 326 #endif                          /* _LINUX_DM_IOCTL_H */