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      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_CONTROL_NODE "control"
     15 #define DM_MAX_TYPE_NAME 16
     16 #define DM_NAME_LEN 128
     17 #define DM_UUID_LEN 129
     18 
     19 /*
     20  * A traditional ioctl interface for the device mapper.
     21  *
     22  * Each device can have two tables associated with it, an
     23  * 'active' table which is the one currently used by io passing
     24  * through the device, and an 'inactive' one which is a table
     25  * that is being prepared as a replacement for the 'active' one.
     26  *
     27  * DM_VERSION:
     28  * Just get the version information for the ioctl interface.
     29  *
     30  * DM_REMOVE_ALL:
     31  * Remove all dm devices, destroy all tables.  Only really used
     32  * for debug.
     33  *
     34  * DM_LIST_DEVICES:
     35  * Get a list of all the dm device names.
     36  *
     37  * DM_DEV_CREATE:
     38  * Create a new device, neither the 'active' or 'inactive' table
     39  * slots will be filled.  The device will be in suspended state
     40  * after creation, however any io to the device will get errored
     41  * since it will be out-of-bounds.
     42  *
     43  * DM_DEV_REMOVE:
     44  * Remove a device, destroy any tables.
     45  *
     46  * DM_DEV_RENAME:
     47  * Rename a device or set its uuid if none was previously supplied.
     48  *
     49  * DM_SUSPEND:
     50  * This performs both suspend and resume, depending which flag is
     51  * passed in.
     52  * Suspend: This command will not return until all pending io to
     53  * the device has completed.  Further io will be deferred until
     54  * the device is resumed.
     55  * Resume: It is no longer an error to issue this command on an
     56  * unsuspended device.  If a table is present in the 'inactive'
     57  * slot, it will be moved to the active slot, then the old table
     58  * from the active slot will be _destroyed_.  Finally the device
     59  * is resumed.
     60  *
     61  * DM_DEV_STATUS:
     62  * Retrieves the status for the table in the 'active' slot.
     63  *
     64  * DM_DEV_WAIT:
     65  * Wait for a significant event to occur to the device.  This
     66  * could either be caused by an event triggered by one of the
     67  * targets of the table in the 'active' slot, or a table change.
     68  *
     69  * DM_TABLE_LOAD:
     70  * Load a table into the 'inactive' slot for the device.  The
     71  * device does _not_ need to be suspended prior to this command.
     72  *
     73  * DM_TABLE_CLEAR:
     74  * Destroy any table in the 'inactive' slot (ie. abort).
     75  *
     76  * DM_TABLE_DEPS:
     77  * Return a set of device dependencies for the 'active' table.
     78  *
     79  * DM_TABLE_STATUS:
     80  * Return the targets status for the 'active' table.
     81  *
     82  * DM_TARGET_MSG:
     83  * Pass a message string to the target at a specific offset of a device.
     84  *
     85  * DM_DEV_SET_GEOMETRY:
     86  * Set the geometry of a device by passing in a string in this format:
     87  *
     88  * "cylinders heads sectors_per_track start_sector"
     89  *
     90  * Beware that CHS geometry is nearly obsolete and only provided
     91  * for compatibility with dm devices that can be booted by a PC
     92  * BIOS.  See struct hd_geometry for range limits.  Also note that
     93  * the geometry is erased if the device size changes.
     94  */
     95 
     96 /*
     97  * All ioctl arguments consist of a single chunk of memory, with
     98  * this structure at the start.  If a uuid is specified any
     99  * lookup (eg. for a DM_INFO) will be done on that, *not* the
    100  * name.
    101  */
    102 struct dm_ioctl {
    103 	/*
    104 	 * The version number is made up of three parts:
    105 	 * major - no backward or forward compatibility,
    106 	 * minor - only backwards compatible,
    107 	 * patch - both backwards and forwards compatible.
    108 	 *
    109 	 * All clients of the ioctl interface should fill in the
    110 	 * version number of the interface that they were
    111 	 * compiled with.
    112 	 *
    113 	 * All recognised ioctl commands (ie. those that don't
    114 	 * return -ENOTTY) fill out this field, even if the
    115 	 * command failed.
    116 	 */
    117 	__u32 version[3];	/* in/out */
    118 	__u32 data_size;	/* total size of data passed in
    119 				 * including this struct */
    120 
    121 	__u32 data_start;	/* offset to start of data
    122 				 * relative to start of this struct */
    123 
    124 	__u32 target_count;	/* in/out */
    125 	__s32 open_count;	/* out */
    126 	__u32 flags;		/* in/out */
    127 
    128 	/*
    129 	 * event_nr holds either the event number (input and output) or the
    130 	 * udev cookie value (input only).
    131 	 * The DM_DEV_WAIT ioctl takes an event number as input.
    132 	 * The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls
    133 	 * use the field as a cookie to return in the DM_COOKIE
    134 	 * variable with the uevents they issue.
    135 	 * For output, the ioctls return the event number, not the cookie.
    136 	 */
    137 	__u32 event_nr;      	/* in/out */
    138 	__u32 padding;
    139 
    140 	__u64 dev;		/* in/out */
    141 
    142 	char name[DM_NAME_LEN];	/* device name */
    143 	char uuid[DM_UUID_LEN];	/* unique identifier for
    144 				 * the block device */
    145 	char data[7];		/* padding or data */
    146 };
    147 
    148 /*
    149  * Used to specify tables.  These structures appear after the
    150  * dm_ioctl.
    151  */
    152 struct dm_target_spec {
    153 	__u64 sector_start;
    154 	__u64 length;
    155 	__s32 status;		/* used when reading from kernel only */
    156 
    157 	/*
    158 	 * Location of the next dm_target_spec.
    159 	 * - When specifying targets on a DM_TABLE_LOAD command, this value is
    160 	 *   the number of bytes from the start of the "current" dm_target_spec
    161 	 *   to the start of the "next" dm_target_spec.
    162 	 * - When retrieving targets on a DM_TABLE_STATUS command, this value
    163 	 *   is the number of bytes from the start of the first dm_target_spec
    164 	 *   (that follows the dm_ioctl struct) to the start of the "next"
    165 	 *   dm_target_spec.
    166 	 */
    167 	__u32 next;
    168 
    169 	char target_type[DM_MAX_TYPE_NAME];
    170 
    171 	/*
    172 	 * Parameter string starts immediately after this object.
    173 	 * Be careful to add padding after string to ensure correct
    174 	 * alignment of subsequent dm_target_spec.
    175 	 */
    176 };
    177 
    178 /*
    179  * Used to retrieve the target dependencies.
    180  */
    181 struct dm_target_deps {
    182 	__u32 count;	/* Array size */
    183 	__u32 padding;	/* unused */
    184 	__u64 dev[0];	/* out */
    185 };
    186 
    187 /*
    188  * Used to get a list of all dm devices.
    189  */
    190 struct dm_name_list {
    191 	__u64 dev;
    192 	__u32 next;		/* offset to the next record from
    193 				   the _start_ of this */
    194 	char name[0];
    195 };
    196 
    197 /*
    198  * Used to retrieve the target versions
    199  */
    200 struct dm_target_versions {
    201         __u32 next;
    202         __u32 version[3];
    203 
    204         char name[0];
    205 };
    206 
    207 /*
    208  * Used to pass message to a target
    209  */
    210 struct dm_target_msg {
    211 	__u64 sector;	/* Device sector */
    212 
    213 	char message[0];
    214 };
    215 
    216 /*
    217  * If you change this make sure you make the corresponding change
    218  * to dm-ioctl.c:lookup_ioctl()
    219  */
    220 enum {
    221 	/* Top level cmds */
    222 	DM_VERSION_CMD = 0,
    223 	DM_REMOVE_ALL_CMD,
    224 	DM_LIST_DEVICES_CMD,
    225 
    226 	/* device level cmds */
    227 	DM_DEV_CREATE_CMD,
    228 	DM_DEV_REMOVE_CMD,
    229 	DM_DEV_RENAME_CMD,
    230 	DM_DEV_SUSPEND_CMD,
    231 	DM_DEV_STATUS_CMD,
    232 	DM_DEV_WAIT_CMD,
    233 
    234 	/* Table level cmds */
    235 	DM_TABLE_LOAD_CMD,
    236 	DM_TABLE_CLEAR_CMD,
    237 	DM_TABLE_DEPS_CMD,
    238 	DM_TABLE_STATUS_CMD,
    239 
    240 	/* Added later */
    241 	DM_LIST_VERSIONS_CMD,
    242 	DM_TARGET_MSG_CMD,
    243 	DM_DEV_SET_GEOMETRY_CMD
    244 };
    245 
    246 #define DM_IOCTL 0xfd
    247 
    248 #define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
    249 #define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
    250 #define DM_LIST_DEVICES  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
    251 
    252 #define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
    253 #define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
    254 #define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
    255 #define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
    256 #define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
    257 #define DM_DEV_WAIT      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
    258 
    259 #define DM_TABLE_LOAD    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
    260 #define DM_TABLE_CLEAR   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
    261 #define DM_TABLE_DEPS    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
    262 #define DM_TABLE_STATUS  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
    263 
    264 #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl)
    265 
    266 #define DM_TARGET_MSG	 _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
    267 #define DM_DEV_SET_GEOMETRY	_IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
    268 
    269 #define DM_VERSION_MAJOR	4
    270 #define DM_VERSION_MINOR	22
    271 #define DM_VERSION_PATCHLEVEL	0
    272 #define DM_VERSION_EXTRA	"-ioctl (2011-10-19)"
    273 
    274 /* Status bits */
    275 #define DM_READONLY_FLAG	(1 << 0) /* In/Out */
    276 #define DM_SUSPEND_FLAG		(1 << 1) /* In/Out */
    277 #define DM_PERSISTENT_DEV_FLAG	(1 << 3) /* In */
    278 
    279 /*
    280  * Flag passed into ioctl STATUS command to get table information
    281  * rather than current status.
    282  */
    283 #define DM_STATUS_TABLE_FLAG	(1 << 4) /* In */
    284 
    285 /*
    286  * Flags that indicate whether a table is present in either of
    287  * the two table slots that a device has.
    288  */
    289 #define DM_ACTIVE_PRESENT_FLAG   (1 << 5) /* Out */
    290 #define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
    291 
    292 /*
    293  * Indicates that the buffer passed in wasn't big enough for the
    294  * results.
    295  */
    296 #define DM_BUFFER_FULL_FLAG	(1 << 8) /* Out */
    297 
    298 /*
    299  * This flag is now ignored.
    300  */
    301 #define DM_SKIP_BDGET_FLAG	(1 << 9) /* In */
    302 
    303 /*
    304  * Set this to avoid attempting to freeze any filesystem when suspending.
    305  */
    306 #define DM_SKIP_LOCKFS_FLAG	(1 << 10) /* In */
    307 
    308 /*
    309  * Set this to suspend without flushing queued ios.
    310  */
    311 #define DM_NOFLUSH_FLAG		(1 << 11) /* In */
    312 
    313 /*
    314  * If set, any table information returned will relate to the inactive
    315  * table instead of the live one.  Always check DM_INACTIVE_PRESENT_FLAG
    316  * is set before using the data returned.
    317  */
    318 #define DM_QUERY_INACTIVE_TABLE_FLAG	(1 << 12) /* In */
    319 
    320 /*
    321  * If set, a uevent was generated for which the caller may need to wait.
    322  */
    323 #define DM_UEVENT_GENERATED_FLAG	(1 << 13) /* Out */
    324 
    325 /*
    326  * If set, rename changes the uuid not the name.  Only permitted
    327  * if no uuid was previously supplied: an existing uuid cannot be changed.
    328  */
    329 #define DM_UUID_FLAG			(1 << 14) /* In */
    330 
    331 /*
    332  * If set, all buffers are wiped after use. Use when sending
    333  * or requesting sensitive data such as an encryption key.
    334  */
    335 #define DM_SECURE_DATA_FLAG		(1 << 15) /* In */
    336 
    337 #endif				/* _LINUX_DM_IOCTL_H */
    338