include/uapi/linux/dm-ioctl.h

   1 /* SPDX-License-Identifier: LGPL-2.0+ WITH Linux-syscall-note */
   2 /*
   3  * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
   4  * Copyright (C) 2004 - 2009 Red Hat, Inc. All rights reserved.
   5  *
   6  * This file is released under the LGPL.
   7  */
   8
   9 #ifndef _LINUX_DM_IOCTL_V4_H
  10 #define _LINUX_DM_IOCTL_V4_H
  11
  12 #include <linux/types.h>
  13
  14 #define DM_DIR "mapper"         /* Slashes not supported */
  15 #define DM_CONTROL_NODE "control"
  16 #define DM_MAX_TYPE_NAME 16
  17 #define DM_NAME_LEN 128
  18 #define DM_UUID_LEN 129
  19
  20 /*
  21  * A traditional ioctl interface for the device mapper.
  22  *
  23  * Each device can have two tables associated with it, an
  24  * 'active' table which is the one currently used by io passing
  25  * through the device, and an 'inactive' one which is a table
  26  * that is being prepared as a replacement for the 'active' one.
  27  *
  28  * DM_VERSION:
  29  * Just get the version information for the ioctl interface.
  30  *
  31  * DM_REMOVE_ALL:
  32  * Remove all dm devices, destroy all tables.  Only really used
  33  * for debug.
  34  *
  35  * DM_LIST_DEVICES:
  36  * Get a list of all the dm device names.
  37  *
  38  * DM_DEV_CREATE:
  39  * Create a new device, neither the 'active' or 'inactive' table
  40  * slots will be filled.  The device will be in suspended state
  41  * after creation, however any io to the device will get errored
  42  * since it will be out-of-bounds.
  43  *
  44  * DM_DEV_REMOVE:
  45  * Remove a device, destroy any tables.
  46  *
  47  * DM_DEV_RENAME:
  48  * Rename a device or set its uuid if none was previously supplied.
  49  *
  50  * DM_SUSPEND:
  51  * This performs both suspend and resume, depending which flag is
  52  * passed in.
  53  * Suspend: This command will not return until all pending io to
  54  * the device has completed.  Further io will be deferred until
  55  * the device is resumed.
  56  * Resume: It is no longer an error to issue this command on an
  57  * unsuspended device.  If a table is present in the 'inactive'
  58  * slot, it will be moved to the active slot, then the old table
  59  * from the active slot will be _destroyed_.  Finally the device
  60  * is resumed.
  61  *
  62  * DM_DEV_STATUS:
  63  * Retrieves the status for the table in the 'active' slot.
  64  *
  65  * DM_DEV_WAIT:
  66  * Wait for a significant event to occur to the device.  This
  67  * could either be caused by an event triggered by one of the
  68  * targets of the table in the 'active' slot, or a table change.
  69  *
  70  * DM_TABLE_LOAD:
  71  * Load a table into the 'inactive' slot for the device.  The
  72  * device does _not_ need to be suspended prior to this command.
  73  *
  74  * DM_TABLE_CLEAR:
  75  * Destroy any table in the 'inactive' slot (ie. abort).
  76  *
  77  * DM_TABLE_DEPS:
  78  * Return a set of device dependencies for the 'active' table.
  79  *
  80  * DM_TABLE_STATUS:
  81  * Return the targets status for the 'active' table.
  82  *
  83  * DM_TARGET_MSG:
  84  * Pass a message string to the target at a specific offset of a device.
  85  *
  86  * DM_DEV_SET_GEOMETRY:
  87  * Set the geometry of a device by passing in a string in this format:
  88  *
  89  * "cylinders heads sectors_per_track start_sector"
  90  *
  91  * Beware that CHS geometry is nearly obsolete and only provided
  92  * for compatibility with dm devices that can be booted by a PC
  93  * BIOS.  See struct hd_geometry for range limits.  Also note that
  94  * the geometry is erased if the device size changes.
  95  */
  96
  97 /*
  98  * All ioctl arguments consist of a single chunk of memory, with
  99  * this structure at the start.  If a uuid is specified any
 100  * lookup (eg. for a DM_INFO) will be done on that, *not* the
 101  * name.
 102  */
 103 struct dm_ioctl {
 104         /*
 105          * The version number is made up of three parts:
 106          * major - no backward or forward compatibility,
 107          * minor - only backwards compatible,
 108          * patch - both backwards and forwards compatible.
 109          *
 110          * All clients of the ioctl interface should fill in the
 111          * version number of the interface that they were
 112          * compiled with.
 113          *
 114          * All recognised ioctl commands (ie. those that don't
 115          * return -ENOTTY) fill out this field, even if the
 116          * command failed.
 117          */
 118         __u32 version[3];       /* in/out */
 119         __u32 data_size;        /* total size of data passed in
 120                                  * including this struct */
 121
 122         __u32 data_start;       /* offset to start of data
 123                                  * relative to start of this struct */
 124
 125         __u32 target_count;     /* in/out */
 126         __s32 open_count;       /* out */
 127         __u32 flags;            /* in/out */
 128
 129         /*
 130          * event_nr holds either the event number (input and output) or the
 131          * udev cookie value (input only).
 132          * The DM_DEV_WAIT ioctl takes an event number as input.
 133          * The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls
 134          * use the field as a cookie to return in the DM_COOKIE
 135          * variable with the uevents they issue.
 136          * For output, the ioctls return the event number, not the cookie.
 137          */
 138         __u32 event_nr;         /* in/out */
 139         __u32 padding;
 140
 141         __u64 dev;              /* in/out */
 142
 143         char name[DM_NAME_LEN]; /* device name */
 144         char uuid[DM_UUID_LEN]; /* unique identifier for
 145                                  * the block device */
 146         char data[7];           /* padding or data */
 147 };
 148
 149 /*
 150  * Used to specify tables.  These structures appear after the
 151  * dm_ioctl.
 152  */
 153 struct dm_target_spec {
 154         __u64 sector_start;
 155         __u64 length;
 156         __s32 status;           /* used when reading from kernel only */
 157
 158         /*
 159          * Location of the next dm_target_spec.
 160          * - When specifying targets on a DM_TABLE_LOAD command, this value is
 161          *   the number of bytes from the start of the "current" dm_target_spec
 162          *   to the start of the "next" dm_target_spec.
 163          * - When retrieving targets on a DM_TABLE_STATUS command, this value
 164          *   is the number of bytes from the start of the first dm_target_spec
 165          *   (that follows the dm_ioctl struct) to the start of the "next"
 166          *   dm_target_spec.
 167          */
 168         __u32 next;
 169
 170         char target_type[DM_MAX_TYPE_NAME];
 171
 172         /*
 173          * Parameter string starts immediately after this object.
 174          * Be careful to add padding after string to ensure correct
 175          * alignment of subsequent dm_target_spec.
 176          */
 177 };
 178
 179 /*
 180  * Used to retrieve the target dependencies.
 181  */
 182 struct dm_target_deps {
 183         __u32 count;    /* Array size */
 184         __u32 padding;  /* unused */
 185         __u64 dev[0];   /* out */
 186 };
 187
 188 /*
 189  * Used to get a list of all dm devices.
 190  */
 191 struct dm_name_list {
 192         __u64 dev;
 193         __u32 next;             /* offset to the next record from
 194                                    the _start_ of this */
 195         char name[0];
 196 };
 197
 198 /*
 199  * Used to retrieve the target versions
 200  */
 201 struct dm_target_versions {
 202         __u32 next;
 203         __u32 version[3];
 204
 205         char name[0];
 206 };
 207
 208 /*
 209  * Used to pass message to a target
 210  */
 211 struct dm_target_msg {
 212         __u64 sector;   /* Device sector */
 213
 214         char message[0];
 215 };
 216
 217 /*
 218  * If you change this make sure you make the corresponding change
 219  * to dm-ioctl.c:lookup_ioctl()
 220  */
 221 enum {
 222         /* Top level cmds */
 223         DM_VERSION_CMD = 0,
 224         DM_REMOVE_ALL_CMD,
 225         DM_LIST_DEVICES_CMD,
 226
 227         /* device level cmds */
 228         DM_DEV_CREATE_CMD,
 229         DM_DEV_REMOVE_CMD,
 230         DM_DEV_RENAME_CMD,
 231         DM_DEV_SUSPEND_CMD,
 232         DM_DEV_STATUS_CMD,
 233         DM_DEV_WAIT_CMD,
 234
 235         /* Table level cmds */
 236         DM_TABLE_LOAD_CMD,
 237         DM_TABLE_CLEAR_CMD,
 238         DM_TABLE_DEPS_CMD,
 239         DM_TABLE_STATUS_CMD,
 240
 241         /* Added later */
 242         DM_LIST_VERSIONS_CMD,
 243         DM_TARGET_MSG_CMD,
 244         DM_DEV_SET_GEOMETRY_CMD,
 245         DM_DEV_ARM_POLL_CMD,
 246         DM_GET_TARGET_VERSION_CMD,
 247 };
 248
 249 #define DM_IOCTL 0xfd
 250
 251 #define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
 252 #define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
 253 #define DM_LIST_DEVICES  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
 254
 255 #define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
 256 #define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
 257 #define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
 258 #define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
 259 #define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
 260 #define DM_DEV_WAIT      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
 261 #define DM_DEV_ARM_POLL  _IOWR(DM_IOCTL, DM_DEV_ARM_POLL_CMD, struct dm_ioctl)
 262
 263 #define DM_TABLE_LOAD    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
 264 #define DM_TABLE_CLEAR   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
 265 #define DM_TABLE_DEPS    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
 266 #define DM_TABLE_STATUS  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
 267
 268 #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
 269 #define DM_GET_TARGET_VERSION _IOWR(DM_IOCTL, DM_GET_TARGET_VERSION_CMD, struct dm_ioctl)
 270
 271 #define DM_TARGET_MSG    _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
 272 #define DM_DEV_SET_GEOMETRY     _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 273
 274 #define DM_VERSION_MAJOR        4
 275 #define DM_VERSION_MINOR        43
 276 #define DM_VERSION_PATCHLEVEL   0
 277 #define DM_VERSION_EXTRA        "-ioctl (2020-10-01)"
 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  * This flag is now ignored.
 305  */
 306 #define DM_SKIP_BDGET_FLAG      (1 << 9) /* In */
 307
 308 /*
 309  * Set this to avoid attempting to freeze any filesystem when suspending.
 310  */
 311 #define DM_SKIP_LOCKFS_FLAG     (1 << 10) /* In */
 312
 313 /*
 314  * Set this to suspend without flushing queued ios.
 315  * Also disables flushing uncommitted changes in the thin target before
 316  * generating statistics for DM_TABLE_STATUS and DM_DEV_WAIT.
 317  */
 318 #define DM_NOFLUSH_FLAG         (1 << 11) /* In */
 319
 320 /*
 321  * If set, any table information returned will relate to the inactive
 322  * table instead of the live one.  Always check DM_INACTIVE_PRESENT_FLAG
 323  * is set before using the data returned.
 324  */
 325 #define DM_QUERY_INACTIVE_TABLE_FLAG    (1 << 12) /* In */
 326
 327 /*
 328  * If set, a uevent was generated for which the caller may need to wait.
 329  */
 330 #define DM_UEVENT_GENERATED_FLAG        (1 << 13) /* Out */
 331
 332 /*
 333  * If set, rename changes the uuid not the name.  Only permitted
 334  * if no uuid was previously supplied: an existing uuid cannot be changed.
 335  */
 336 #define DM_UUID_FLAG                    (1 << 14) /* In */
 337
 338 /*
 339  * If set, all buffers are wiped after use. Use when sending
 340  * or requesting sensitive data such as an encryption key.
 341  */
 342 #define DM_SECURE_DATA_FLAG             (1 << 15) /* In */
 343
 344 /*
 345  * If set, a message generated output data.
 346  */
 347 #define DM_DATA_OUT_FLAG                (1 << 16) /* Out */
 348
 349 /*
 350  * If set with DM_DEV_REMOVE or DM_REMOVE_ALL this indicates that if
 351  * the device cannot be removed immediately because it is still in use
 352  * it should instead be scheduled for removal when it gets closed.
 353  *
 354  * On return from DM_DEV_REMOVE, DM_DEV_STATUS or other ioctls, this
 355  * flag indicates that the device is scheduled to be removed when it
 356  * gets closed.
 357  */
 358 #define DM_DEFERRED_REMOVE              (1 << 17) /* In/Out */
 359
 360 /*
 361  * If set, the device is suspended internally.
 362  */
 363 #define DM_INTERNAL_SUSPEND_FLAG        (1 << 18) /* Out */
 364
 365 #endif                          /* _LINUX_DM_IOCTL_H */