Home | History | Annotate | Download | only in linux
      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 	__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	15
    270 #define DM_VERSION_PATCHLEVEL	0
    271 #define DM_VERSION_EXTRA	"-ioctl (2009-04-01)"
    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 #endif				/* _LINUX_DM_IOCTL_H */
    313