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
  85 /*
  86  * All ioctl arguments consist of a single chunk of memory, with
  87  * this structure at the start.  If a uuid is specified any
  88  * lookup (eg. for a DM_INFO) will be done on that, *not* the
  89  * name.
  90  */
  91 struct dm_ioctl {
  92         /*
  93          * The version number is made up of three parts:
  94          * major - no backward or forward compatibility,
  95          * minor - only backwards compatible,
  96          * patch - both backwards and forwards compatible.
  97          *
  98          * All clients of the ioctl interface should fill in the
  99          * version number of the interface that they were
 100          * compiled with.
 101          *
 102          * All recognised ioctl commands (ie. those that don't
 103          * return -ENOTTY) fill out this field, even if the
 104          * command failed.
 105          */
 106         uint32_t version[3];    /* in/out */
 107         uint32_t data_size;     /* total size of data passed in
 108                                  * including this struct */
 109
 110         uint32_t data_start;    /* offset to start of data
 111                                  * relative to start of this struct */
 112
 113         uint32_t target_count;  /* in/out */
 114         int32_t open_count;     /* out */
 115         uint32_t flags;         /* in/out */
 116         uint32_t event_nr;              /* in/out */
 117         uint32_t padding;
 118
 119         uint64_t dev;           /* in/out */
 120
 121         char name[DM_NAME_LEN]; /* device name */
 122         char uuid[DM_UUID_LEN]; /* unique identifier for
 123                                  * the block device */
 124 };
 125
 126 /*
 127  * Used to specify tables.  These structures appear after the
 128  * dm_ioctl.
 129  */
 130 struct dm_target_spec {
 131         uint64_t sector_start;
 132         uint64_t length;
 133         int32_t status;         /* used when reading from kernel only */
 134
 135         /*
 136          * Location of the next dm_target_spec.
 137          * - When specifying targets on a DM_TABLE_LOAD command, this value is
 138          *   the number of bytes from the start of the "current" dm_target_spec
 139          *   to the start of the "next" dm_target_spec.
 140          * - When retrieving targets on a DM_TABLE_STATUS command, this value
 141          *   is the number of bytes from the start of the first dm_target_spec
 142          *   (that follows the dm_ioctl struct) to the start of the "next"
 143          *   dm_target_spec.
 144          */
 145         uint32_t next;
 146
 147         char target_type[DM_MAX_TYPE_NAME];
 148
 149         /*
 150          * Parameter string starts immediately after this object.
 151          * Be careful to add padding after string to ensure correct
 152          * alignment of subsequent dm_target_spec.
 153          */
 154 };
 155
 156 /*
 157  * Used to retrieve the target dependencies.
 158  */
 159 struct dm_target_deps {
 160         uint32_t count; /* Array size */
 161         uint32_t padding;       /* unused */
 162         uint64_t dev[0];        /* out */
 163 };
 164
 165 /*
 166  * Used to get a list of all dm devices.
 167  */
 168 struct dm_name_list {
 169         uint64_t dev;
 170         uint32_t next;          /* offset to the next record from
 171                                    the _start_ of this */
 172         char name[0];
 173 };
 174
 175 /*
 176  * Used to retrieve the target versions
 177  */
 178 struct dm_target_versions {
 179         uint32_t next;
 180         uint32_t version[3];
 181
 182         char name[0];
 183 };
 184
 185 /*
 186  * Used to pass message to a target
 187  */
 188 struct dm_target_msg {
 189         uint64_t sector;        /* Device sector */
 190
 191         char message[0];
 192 };
 193
 194 /*
 195  * If you change this make sure you make the corresponding change
 196  * to dm-ioctl.c:lookup_ioctl()
 197  */
 198 enum {
 199         /* Top level cmds */
 200         DM_VERSION_CMD = 0,
 201         DM_REMOVE_ALL_CMD,
 202         DM_LIST_DEVICES_CMD,
 203
 204         /* device level cmds */
 205         DM_DEV_CREATE_CMD,
 206         DM_DEV_REMOVE_CMD,
 207         DM_DEV_RENAME_CMD,
 208         DM_DEV_SUSPEND_CMD,
 209         DM_DEV_STATUS_CMD,
 210         DM_DEV_WAIT_CMD,
 211
 212         /* Table level cmds */
 213         DM_TABLE_LOAD_CMD,
 214         DM_TABLE_CLEAR_CMD,
 215         DM_TABLE_DEPS_CMD,
 216         DM_TABLE_STATUS_CMD,
 217
 218         /* Added later */
 219         DM_LIST_VERSIONS_CMD,
 220         DM_TARGET_MSG_CMD,
 221 };
 222
 223 /*
 224  * The dm_ioctl struct passed into the ioctl is just the header
 225  * on a larger chunk of memory.  On x86-64 and other
 226  * architectures the dm-ioctl struct will be padded to an 8 byte
 227  * boundary so the size will be different, which would change the
 228  * ioctl code - yes I really messed up.  This hack forces these
 229  * architectures to have the correct ioctl code.
 230  */
 231 #ifdef CONFIG_COMPAT
 232 typedef char ioctl_struct[308];
 233 #define DM_VERSION_32       _IOWR(DM_IOCTL, DM_VERSION_CMD, ioctl_struct)
 234 #define DM_REMOVE_ALL_32    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, ioctl_struct)
 235 #define DM_LIST_DEVICES_32  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, ioctl_struct)
 236
 237 #define DM_DEV_CREATE_32    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, ioctl_struct)
 238 #define DM_DEV_REMOVE_32    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, ioctl_struct)
 239 #define DM_DEV_RENAME_32    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, ioctl_struct)
 240 #define DM_DEV_SUSPEND_32   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, ioctl_struct)
 241 #define DM_DEV_STATUS_32    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, ioctl_struct)
 242 #define DM_DEV_WAIT_32      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, ioctl_struct)
 243
 244 #define DM_TABLE_LOAD_32    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, ioctl_struct)
 245 #define DM_TABLE_CLEAR_32   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, ioctl_struct)
 246 #define DM_TABLE_DEPS_32    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, ioctl_struct)
 247 #define DM_TABLE_STATUS_32  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, ioctl_struct)
 248 #define DM_LIST_VERSIONS_32 _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, ioctl_struct)
 249 #define DM_TARGET_MSG_32    _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, ioctl_struct)
 250 #endif
 251
 252 #define DM_IOCTL 0xfd
 253
 254 #define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
 255 #define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
 256 #define DM_LIST_DEVICES  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
 257
 258 #define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
 259 #define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
 260 #define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
 261 #define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
 262 #define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
 263 #define DM_DEV_WAIT      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
 264
 265 #define DM_TABLE_LOAD    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
 266 #define DM_TABLE_CLEAR   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
 267 #define DM_TABLE_DEPS    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
 268 #define DM_TABLE_STATUS  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
 269
 270 #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
 271
 272 #define DM_TARGET_MSG    _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
 273
 274 #define DM_VERSION_MAJOR        4
 275 #define DM_VERSION_MINOR        4
 276 #define DM_VERSION_PATCHLEVEL   0
 277 #define DM_VERSION_EXTRA        "-ioctl (2005-01-12)"
 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  * Set this to improve performance when you aren't going to use open_count
 305  */
 306 #define DM_SKIP_BDGET_FLAG      (1 << 9) /* In */
 307
 308 #endif                          /* _LINUX_DM_IOCTL_H */