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/*
 * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
 *
 * This file is released under the LGPL.
 */

#ifndef _LINUX_DM_IOCTL_V4_H
#define _LINUX_DM_IOCTL_V4_H

#include <linux/types.h>

#define DM_DIR "mapper"         /* Slashes not supported */
#define DM_MAX_TYPE_NAME 16
#define DM_NAME_LEN 128
#define DM_UUID_LEN 129

/*
 * A traditional ioctl interface for the device mapper.
 *
 * Each device can have two tables associated with it, an
 * 'active' table which is the one currently used by io passing
 * through the device, and an 'inactive' one which is a table
 * that is being prepared as a replacement for the 'active' one.
 *
 * DM_VERSION:
 * Just get the version information for the ioctl interface.
 *
 * DM_REMOVE_ALL:
 * Remove all dm devices, destroy all tables.  Only really used
 * for debug.
 *
 * DM_LIST_DEVICES:
 * Get a list of all the dm device names.
 *
 * DM_DEV_CREATE:
 * Create a new device, neither the 'active' or 'inactive' table
 * slots will be filled.  The device will be in suspended state
 * after creation, however any io to the device will get errored
 * since it will be out-of-bounds.
 *
 * DM_DEV_REMOVE:
 * Remove a device, destroy any tables.
 *
 * DM_DEV_RENAME:
 * Rename a device.
 *
 * DM_SUSPEND:
 * This performs both suspend and resume, depending which flag is
 * passed in.
 * Suspend: This command will not return until all pending io to
 * the device has completed.  Further io will be deferred until
 * the device is resumed.
 * Resume: It is no longer an error to issue this command on an
 * unsuspended device.  If a table is present in the 'inactive'
 * slot, it will be moved to the active slot, then the old table
 * from the active slot will be _destroyed_.  Finally the device
 * is resumed.
 *
 * DM_DEV_STATUS:
 * Retrieves the status for the table in the 'active' slot.
 *
 * DM_DEV_WAIT:
 * Wait for a significant event to occur to the device.  This
 * could either be caused by an event triggered by one of the
 * targets of the table in the 'active' slot, or a table change.
 *
 * DM_TABLE_LOAD:
 * Load a table into the 'inactive' slot for the device.  The
 * device does _not_ need to be suspended prior to this command.
 *
 * DM_TABLE_CLEAR:
 * Destroy any table in the 'inactive' slot (ie. abort).
 *
 * DM_TABLE_DEPS:
 * Return a set of device dependencies for the 'active' table.
 *
 * DM_TABLE_STATUS:
 * Return the targets status for the 'active' table.
 */

/*
 * All ioctl arguments consist of a single chunk of memory, with
 * this structure at the start.  If a uuid is specified any
 * lookup (eg. for a DM_INFO) will be done on that, *not* the
 * name.
 */
struct dm_ioctl {
        /*
         * The version number is made up of three parts:
         * major - no backward or forward compatibility,
         * minor - only backwards compatible,
         * patch - both backwards and forwards compatible.
         *
         * All clients of the ioctl interface should fill in the
         * version number of the interface that they were
         * compiled with.
         *
         * All recognised ioctl commands (ie. those that don't
         * return -ENOTTY) fill out this field, even if the
         * command failed.
         */
        uint32_t version[3];    /* in/out */
        uint32_t data_size;     /* total size of data passed in
                                 * including this struct */

        uint32_t data_start;    /* offset to start of data
                                 * relative to start of this struct */

        uint32_t target_count;  /* in/out */
        int32_t open_count;     /* out */
        uint32_t flags;         /* in/out */
        uint32_t event_nr;              /* in/out */
        uint32_t padding;

        uint64_t dev;           /* in/out */

        char name[DM_NAME_LEN]; /* device name */
        char uuid[DM_UUID_LEN]; /* unique identifier for
                                 * the block device */
};

/*
 * Used to specify tables.  These structures appear after the
 * dm_ioctl.
 */
struct dm_target_spec {
        uint64_t sector_start;
        uint64_t length;
        int32_t status;         /* used when reading from kernel only */

        /*
         * Offset in bytes (from the start of this struct) to
         * next target_spec.
         */
        uint32_t next;

        char target_type[DM_MAX_TYPE_NAME];

        /*
         * Parameter string starts immediately after this object.
         * Be careful to add padding after string to ensure correct
         * alignment of subsequent dm_target_spec.
         */
};

/*
 * Used to retrieve the target dependencies.
 */
struct dm_target_deps {
        uint32_t count; /* Array size */
        uint32_t padding;       /* unused */
        uint64_t dev[0];        /* out */
};

/*
 * Used to get a list of all dm devices.
 */
struct dm_name_list {
        uint64_t dev;
        uint32_t next;          /* offset to the next record from
                                   the _start_ of this */
        char name[0];
};

/*
 * If you change this make sure you make the corresponding change
 * to dm-ioctl.c:lookup_ioctl()
 */
enum {
        /* Top level cmds */
        DM_VERSION_CMD = 0,
        DM_REMOVE_ALL_CMD,
        DM_LIST_DEVICES_CMD,

        /* device level cmds */
        DM_DEV_CREATE_CMD,
        DM_DEV_REMOVE_CMD,
        DM_DEV_RENAME_CMD,
        DM_DEV_SUSPEND_CMD,
        DM_DEV_STATUS_CMD,
        DM_DEV_WAIT_CMD,

        /* Table level cmds */
        DM_TABLE_LOAD_CMD,
        DM_TABLE_CLEAR_CMD,
        DM_TABLE_DEPS_CMD,
        DM_TABLE_STATUS_CMD,
};

#define DM_IOCTL 0xfd

#define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
#define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
#define DM_LIST_DEVICES  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)

#define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
#define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
#define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
#define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
#define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
#define DM_DEV_WAIT      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)

#define DM_TABLE_LOAD    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
#define DM_TABLE_CLEAR   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
#define DM_TABLE_DEPS    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
#define DM_TABLE_STATUS  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)

#define DM_VERSION_MAJOR        4
#define DM_VERSION_MINOR        0
#define DM_VERSION_PATCHLEVEL   0
#define DM_VERSION_EXTRA        "-ioctl (2003-06-04)"

/* Status bits */
#define DM_READONLY_FLAG        (1 << 0) /* In/Out */
#define DM_SUSPEND_FLAG         (1 << 1) /* In/Out */
#define DM_PERSISTENT_DEV_FLAG  (1 << 3) /* In */

/*
 * Flag passed into ioctl STATUS command to get table information
 * rather than current status.
 */
#define DM_STATUS_TABLE_FLAG    (1 << 4) /* In */

/*
 * Flags that indicate whether a table is present in either of
 * the two table slots that a device has.
 */
#define DM_ACTIVE_PRESENT_FLAG   (1 << 5) /* Out */
#define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */

/*
 * Indicates that the buffer passed in wasn't big enough for the
 * results.
 */
#define DM_BUFFER_FULL_FLAG     (1 << 8) /* Out */

#endif                          /* _LINUX_DM_IOCTL_H */