include/linux/dm-ioctl.h

   1 /*
   2  * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
   3  * Copyright (C) 2004 - 2009 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         __u32 version[3];       /* in/out */
 117         __u32 data_size;        /* total size of data passed in
 118                                  * including this struct */
 119
 120         __u32 data_start;       /* offset to start of data
 121                                  * relative to start of this struct */
 122
 123         __u32 target_count;     /* in/out */
 124         __s32 open_count;       /* out */
 125         __u32 flags;            /* in/out */
 126
 127         /*
 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.
 135          */
 136         __u32 event_nr;         /* in/out */
 137         __u32 padding;
 138
 139         __u64 dev;              /* in/out */
 140
 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 */
 145 };
 146
 147 /*
 148  * Used to specify tables.  These structures appear after the
 149  * dm_ioctl.
 150  */
 151 struct dm_target_spec {
 152         __u64 sector_start;
 153         __u64 length;
 154         __s32 status;           /* used when reading from kernel only */
 155
 156         /*
 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.
 165          */
 166         __u32 next;
 167
 168         char target_type[DM_MAX_TYPE_NAME];
 169
 170         /*
 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.
 174          */
 175 };
 176
 177 /*
 178  * Used to retrieve the target dependencies.
 179  */
 180 struct dm_target_deps {
 181         __u32 count;    /* Array size */
 182         __u32 padding;  /* unused */
 183         __u64 dev[0];   /* out */
 184 };
 185
 186 /*
 187  * Used to get a list of all dm devices.
 188  */
 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];
 194 };
 195
 196 /*
 197  * Used to retrieve the target versions
 198  */
 199 struct dm_target_versions {
 200         __u32 next;
 201         __u32 version[3];
 202
 203         char name[0];
 204 };
 205
 206 /*
 207  * Used to pass message to a target
 208  */
 209 struct dm_target_msg {
 210         __u64 sector;   /* Device sector */
 211
 212         char message[0];
 213 };
 214
 215 /*
 216  * If you change this make sure you make the corresponding change
 217  * to dm-ioctl.c:lookup_ioctl()
 218  */
 219 enum {
 220         /* Top level cmds */
 221         DM_VERSION_CMD = 0,
 222         DM_REMOVE_ALL_CMD,
 223         DM_LIST_DEVICES_CMD,
 224
 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,
 232
 233         /* Table level cmds */
 234         DM_TABLE_LOAD_CMD,
 235         DM_TABLE_CLEAR_CMD,
 236         DM_TABLE_DEPS_CMD,
 237         DM_TABLE_STATUS_CMD,
 238
 239         /* Added later */
 240         DM_LIST_VERSIONS_CMD,
 241         DM_TARGET_MSG_CMD,
 242         DM_DEV_SET_GEOMETRY_CMD
 243 };
 244
 245 #define DM_IOCTL 0xfd
 246
 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)
 250
 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)
 257
 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)
 262
 263 #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
 264
 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)
 267
 268 #define DM_VERSION_MAJOR        4
 269 #define DM_VERSION_MINOR        17
 270 #define DM_VERSION_PATCHLEVEL   0
 271 #define DM_VERSION_EXTRA        "-ioctl (2010-03-05)"
 272
 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 */
 277
 278 /*
 279  * Flag passed into ioctl STATUS command to get table information
 280  * rather than current status.
 281  */
 282 #define DM_STATUS_TABLE_FLAG    (1 << 4) /* In */
 283
 284 /*
 285  * Flags that indicate whether a table is present in either of
 286  * the two table slots that a device has.
 287  */
 288 #define DM_ACTIVE_PRESENT_FLAG   (1 << 5) /* Out */
 289 #define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
 290
 291 /*
 292  * Indicates that the buffer passed in wasn't big enough for the
 293  * results.
 294  */
 295 #define DM_BUFFER_FULL_FLAG     (1 << 8) /* Out */
 296
 297 /*
 298  * This flag is now ignored.
 299  */
 300 #define DM_SKIP_BDGET_FLAG      (1 << 9) /* In */
 301
 302 /*
 303  * Set this to avoid attempting to freeze any filesystem when suspending.
 304  */
 305 #define DM_SKIP_LOCKFS_FLAG     (1 << 10) /* In */
 306
 307 /*
 308  * Set this to suspend without flushing queued ios.
 309  */
 310 #define DM_NOFLUSH_FLAG         (1 << 11) /* In */
 311
 312 /*
 313  * If set, any table information returned will relate to the inactive
 314  * table instead of the live one.  Always check DM_INACTIVE_PRESENT_FLAG
 315  * is set before using the data returned.
 316  */
 317 #define DM_QUERY_INACTIVE_TABLE_FLAG    (1 << 12) /* In */
 318
 319 /*
 320  * If set, a uevent was generated for which the caller may need to wait.
 321  */
 322 #define DM_UEVENT_GENERATED_FLAG        (1 << 13) /* Out */
 323
 324 #endif                          /* _LINUX_DM_IOCTL_H */