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         char data[7];           /* padding or data */
 135 };
 136
 137 /*
 138  * Used to specify tables.  These structures appear after the
 139  * dm_ioctl.
 140  */
 141 struct dm_target_spec {
 142         uint64_t sector_start;
 143         uint64_t length;
 144         int32_t status;         /* used when reading from kernel only */
 145
 146         /*
 147          * Location of the next dm_target_spec.
 148          * - When specifying targets on a DM_TABLE_LOAD command, this value is
 149          *   the number of bytes from the start of the "current" dm_target_spec
 150          *   to the start of the "next" dm_target_spec.
 151          * - When retrieving targets on a DM_TABLE_STATUS command, this value
 152          *   is the number of bytes from the start of the first dm_target_spec
 153          *   (that follows the dm_ioctl struct) to the start of the "next"
 154          *   dm_target_spec.
 155          */
 156         uint32_t next;
 157
 158         char target_type[DM_MAX_TYPE_NAME];
 159
 160         /*
 161          * Parameter string starts immediately after this object.
 162          * Be careful to add padding after string to ensure correct
 163          * alignment of subsequent dm_target_spec.
 164          */
 165 };
 166
 167 /*
 168  * Used to retrieve the target dependencies.
 169  */
 170 struct dm_target_deps {
 171         uint32_t count; /* Array size */
 172         uint32_t padding;       /* unused */
 173         uint64_t dev[0];        /* out */
 174 };
 175
 176 /*
 177  * Used to get a list of all dm devices.
 178  */
 179 struct dm_name_list {
 180         uint64_t dev;
 181         uint32_t next;          /* offset to the next record from
 182                                    the _start_ of this */
 183         char name[0];
 184 };
 185
 186 /*
 187  * Used to retrieve the target versions
 188  */
 189 struct dm_target_versions {
 190         uint32_t next;
 191         uint32_t version[3];
 192
 193         char name[0];
 194 };
 195
 196 /*
 197  * Used to pass message to a target
 198  */
 199 struct dm_target_msg {
 200         uint64_t sector;        /* Device sector */
 201
 202         char message[0];
 203 };
 204
 205 /*
 206  * If you change this make sure you make the corresponding change
 207  * to dm-ioctl.c:lookup_ioctl()
 208  */
 209 enum {
 210         /* Top level cmds */
 211         DM_VERSION_CMD = 0,
 212         DM_REMOVE_ALL_CMD,
 213         DM_LIST_DEVICES_CMD,
 214
 215         /* device level cmds */
 216         DM_DEV_CREATE_CMD,
 217         DM_DEV_REMOVE_CMD,
 218         DM_DEV_RENAME_CMD,
 219         DM_DEV_SUSPEND_CMD,
 220         DM_DEV_STATUS_CMD,
 221         DM_DEV_WAIT_CMD,
 222
 223         /* Table level cmds */
 224         DM_TABLE_LOAD_CMD,
 225         DM_TABLE_CLEAR_CMD,
 226         DM_TABLE_DEPS_CMD,
 227         DM_TABLE_STATUS_CMD,
 228
 229         /* Added later */
 230         DM_LIST_VERSIONS_CMD,
 231         DM_TARGET_MSG_CMD,
 232         DM_DEV_SET_GEOMETRY_CMD
 233 };
 234
 235 #define DM_IOCTL 0xfd
 236
 237 #define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
 238 #define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
 239 #define DM_LIST_DEVICES  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
 240
 241 #define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
 242 #define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
 243 #define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
 244 #define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
 245 #define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
 246 #define DM_DEV_WAIT      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
 247
 248 #define DM_TABLE_LOAD    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
 249 #define DM_TABLE_CLEAR   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
 250 #define DM_TABLE_DEPS    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
 251 #define DM_TABLE_STATUS  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
 252
 253 #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
 254
 255 #define DM_TARGET_MSG    _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
 256 #define DM_DEV_SET_GEOMETRY     _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 257
 258 #define DM_VERSION_MAJOR        4
 259 #define DM_VERSION_MINOR        13
 260 #define DM_VERSION_PATCHLEVEL   0
 261 #define DM_VERSION_EXTRA        "-ioctl (2007-10-18)"
 262
 263 /* Status bits */
 264 #define DM_READONLY_FLAG        (1 << 0) /* In/Out */
 265 #define DM_SUSPEND_FLAG         (1 << 1) /* In/Out */
 266 #define DM_PERSISTENT_DEV_FLAG  (1 << 3) /* In */
 267
 268 /*
 269  * Flag passed into ioctl STATUS command to get table information
 270  * rather than current status.
 271  */
 272 #define DM_STATUS_TABLE_FLAG    (1 << 4) /* In */
 273
 274 /*
 275  * Flags that indicate whether a table is present in either of
 276  * the two table slots that a device has.
 277  */
 278 #define DM_ACTIVE_PRESENT_FLAG   (1 << 5) /* Out */
 279 #define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
 280
 281 /*
 282  * Indicates that the buffer passed in wasn't big enough for the
 283  * results.
 284  */
 285 #define DM_BUFFER_FULL_FLAG     (1 << 8) /* Out */
 286
 287 /*
 288  * This flag is now ignored.
 289  */
 290 #define DM_SKIP_BDGET_FLAG      (1 << 9) /* In */
 291
 292 /*
 293  * Set this to avoid attempting to freeze any filesystem when suspending.
 294  */
 295 #define DM_SKIP_LOCKFS_FLAG     (1 << 10) /* In */
 296
 297 /*
 298  * Set this to suspend without flushing queued ios.
 299  */
 300 #define DM_NOFLUSH_FLAG         (1 << 11) /* In */
 301
 302 #endif                          /* _LINUX_DM_IOCTL_H */