/* $NetBSD: dm_ioctl.c,v 1.21 2010/02/25 20:48:58 jakllsch Exp $      */

/*
 * Copyright (c) 2010-2011 Alex Hornung <alex@alexhornung.com>
 * Copyright (c) 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Adam Hamsik.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Locking is used to synchronise between ioctl calls and between dm_table's
 * users.
 *
 * ioctl locking:
 * Simple reference counting, to count users of device will be used routines
 * dm_dev_busy/dm_dev_unbusy are used for that.
 * dm_dev_lookup/dm_dev_rem call dm_dev_busy before return(caller is therefore
 * holder of reference_counter last).
 *
 * ioctl routines which change/remove dm_dev parameters must wait on
 * dm_dev::dev_cv and when last user will call dm_dev_unbusy they will wake
 * up them.
 *
 * table_head locking:
 * To access table entries dm_table_* routines must be used.
 *
 * dm_table_get_entry will increment table users reference
 * counter. It will return active or inactive table depends
 * on uint8_t argument.
 *
 * dm_table_release must be called for every table_entry from
 * dm_table_get_entry. Between these to calls tables can'tbe switched
 * or destroyed.
 *
 * dm_table_head_init initialize talbe_entries TAILQS and io_cv.
 *
 * dm_table_head_destroy destroy cv.
 *
 * There are two types of users for dm_table_head first type will
 * only read list and try to do anything with it e.g. dmstrategy,
 * dm_table_size etc. There is another user for table_head which wants
 * to change table lists e.g. dm_dev_resume_ioctl, dm_dev_remove_ioctl,
 * dm_table_clear_ioctl.
 *
 * NOTE: It is not allowed to call dm_table_destroy, dm_table_switch_tables
 *       with hold table reference counter. Table reference counter is hold
 *       after calling dm_table_get_entry routine. After calling this
 *       function user must call dm_table_release before any writer table
 *       operation.
 *
 * Example: dm_table_get_entry
 *          dm_table_destroy/dm_table_switch_tables
 * This exaple will lead to deadlock situation because after dm_table_get_entry
 * table reference counter is != 0 and dm_table_destroy have to wait on cv until
 * reference counter is 0.
 *
 */

#include <sys/param.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <cpu/atomic.h>
#include <dev/disk/dm/dm.h>
#include <dev/disk/dm/netbsd-dm.h>

static int
dm_table_deps(dm_table_entry_t *, prop_array_t);
static int
dm_table_init(dm_target_t *, dm_table_entry_t *, char *);
static int
dm_table_status(dm_table_entry_t *, prop_dictionary_t, uint32_t);

static __inline
void dm_add_flag(prop_dictionary_t dp, uint32_t *fp, const uint32_t val)
{
        KKASSERT(dp != NULL);
        prop_dictionary_get_uint32(dp, DM_IOCTL_FLAGS, fp);
        (*fp) |= val;
        prop_dictionary_set_uint32(dp, DM_IOCTL_FLAGS, *fp);
        KKASSERT((*fp) & val);
}

static __inline
void dm_remove_flag(prop_dictionary_t dp, uint32_t *fp, const uint32_t val)
{
        KKASSERT(dp != NULL);
        prop_dictionary_get_uint32(dp, DM_IOCTL_FLAGS, fp);
        (*fp) &= ~val;
        prop_dictionary_set_uint32(dp, DM_IOCTL_FLAGS, *fp);
        KKASSERT(!((*fp) & val));
}

/*
 * Print flags sent to the kernel from libdevmapper.
 */
static int
dm_dbg_print_flags(uint32_t flags)
{
        if (dm_debug_level == 0)
                return 1;

        kprintf("%s --- flags=%08X\n", __func__, flags);

        if (flags & DM_READONLY_FLAG)
                kprintf("  DM_READONLY_FLAG\n");
        if (flags & DM_SUSPEND_FLAG)
                kprintf("  DM_SUSPEND_FLAG\n");
        if (flags & DM_EXISTS_FLAG)
                kprintf("  DM_EXISTS_FLAG\n");
        if (flags & DM_PERSISTENT_DEV_FLAG)
                kprintf("  DM_PERSISTENT_DEV_FLAG\n");
        if (flags & DM_STATUS_TABLE_FLAG)
                kprintf("  DM_STATUS_TABLE_FLAG\n");
        if (flags & DM_ACTIVE_PRESENT_FLAG)
                kprintf("  DM_ACTIVE_PRESENT_FLAG\n");
        if (flags & DM_INACTIVE_PRESENT_FLAG)
                kprintf("  DM_INACTIVE_PRESENT_FLAG\n");
        if (flags & DM_BUFFER_FULL_FLAG)
                kprintf("  DM_BUFFER_FULL_FLAG\n");
        if (flags & DM_SKIP_BDGET_FLAG)
                kprintf("  DM_SKIP_BDGET_FLAG\n");
        if (flags & DM_SKIP_LOCKFS_FLAG)
                kprintf("  DM_SKIP_LOCKFS_FLAG\n");
        if (flags & DM_NOFLUSH_FLAG)
                kprintf("  DM_NOFLUSH_FLAG\n");
        if (flags & DM_QUERY_INACTIVE_TABLE_FLAG)
                kprintf("  DM_QUERY_INACTIVE_TABLE_FLAG\n");
        if (flags & DM_UUID_FLAG)
                kprintf("  DM_UUID_FLAG\n");
        if (flags & DM_SECURE_DATA_FLAG)
                kprintf("  DM_SECURE_DATA_FLAG\n");

        return 0;
}

/*
 * Get list of all available targets from global
 * target list and sent them back to libdevmapper.
 */
int
dm_list_versions_ioctl(prop_dictionary_t dm_dict)
{
        prop_array_t target_list;
        uint32_t flags;

        flags = 0;

        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);

        dm_dbg_print_flags(flags);
        target_list = dm_target_prop_list();

        prop_dictionary_set(dm_dict, DM_IOCTL_CMD_DATA, target_list);
        prop_object_release(target_list);

        return 0;
}

/*
 * Create in-kernel entry for device. Device attributes such as name, uuid are
 * taken from proplib dictionary.
 */
int
dm_dev_create_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        const char *name, *uuid;
        int r;
        uint32_t flags;

        r = 0;
        flags = 0;
        name = NULL;
        uuid = NULL;

        /* Get needed values from dictionary. */
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);

        dm_dbg_print_flags(flags);

        /* Lookup name and uuid if device already exist quit. */
        if ((dmv = dm_dev_lookup(name, uuid, -1)) != NULL) {
                dm_add_flag(dm_dict, &flags, DM_EXISTS_FLAG);   /* Device already exists */
                dm_dev_unbusy(dmv);
                return EEXIST;
        }

        r = dm_dev_create(&dmv, name, uuid, flags);
        if (r == 0) {
                prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);
                dm_add_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                dm_remove_flag(dm_dict, &flags, DM_INACTIVE_PRESENT_FLAG);
        }

        return r;
}

/*
 * Get list of created device-mapper devices from global list and
 * send it to kernel.
 *
 * Output dictionary:
 *
 * <key>cmd_data</key>
 *  <array>
 *   <dict>
 *    <key>name<key>
 *    <string>...</string>
 *
 *    <key>dev</key>
 *    <integer>...</integer>
 *   </dict>
 *  </array>
 */
int
dm_dev_list_ioctl(prop_dictionary_t dm_dict)
{
        prop_array_t dev_list;

        uint32_t flags;

        flags = 0;

        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);

        dm_dbg_print_flags(flags);

        dev_list = dm_dev_prop_list();

        prop_dictionary_set(dm_dict, DM_IOCTL_CMD_DATA, dev_list);
        prop_object_release(dev_list);

        return 0;
}

/*
 * Rename selected devices old name is in struct dm_ioctl.
 * new name is taken from dictionary.
 *
 * <key>cmd_data</key>
 *  <array>
 *   <string>...</string>
 *  </array>
 */
int
dm_dev_rename_ioctl(prop_dictionary_t dm_dict)
{
#if 0
        prop_array_t cmd_array;
        dm_dev_t *dmv;

        const char *name, *uuid, *n_name;
        uint32_t flags, minor;

        name = NULL;
        uuid = NULL;
        minor = 0;

        /* Get needed values from dictionary. */
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        dm_dbg_print_flags(flags);

        cmd_array = prop_dictionary_get(dm_dict, DM_IOCTL_CMD_DATA);

        prop_array_get_cstring_nocopy(cmd_array, 0, &n_name);

        if (strlen(n_name) + 1 > DM_NAME_LEN)
                return EINVAL;

        if ((dmv = dm_dev_lookup_evict(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        /* change device name */
        /*
         * XXX How to deal with this change, name only used in
         * dm_dev_routines, should I add dm_dev_change_name which will run
         * under the dm_dev_list mutex ?
         */
        strlcpy(dmv->name, n_name, DM_NAME_LEN);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_OPEN, dmv->table_head.io_cnt);
        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);
        prop_dictionary_set_cstring(dm_dict, DM_IOCTL_UUID, dmv->uuid);

        dm_dev_insert(dmv);
#endif

        /*
         * XXX: the rename is not yet implemented. The main complication
         *      here is devfs. We'd probably need a new function, rename_dev()
         *      that would trigger a node rename in devfs.
         */
        kprintf("dm_dev_rename_ioctl called, but not implemented!\n");
        return ENOSYS;
}

/*
 * Remove device
 */
int
dm_dev_remove_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        const char *name, *uuid;
        uint32_t flags, minor, is_open;

        flags = 0;
        name = NULL;
        uuid = NULL;

        /* Get needed values from dictionary. */
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        dm_dbg_print_flags(flags);

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }

        is_open = dmv->is_open;

        dm_dev_unbusy(dmv);

        if (is_open)
                return EBUSY;

        return dm_dev_remove(dmv);
}

/*
 * Try to remove all devices
 */
int
dm_dev_remove_all_ioctl(prop_dictionary_t dm_dict)
{
        uint32_t flags = 0;

        /* Get needed values from dictionary. */
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);

        dm_dbg_print_flags(flags);

        /* Gently remove all devices, if possible */
        return dm_dev_remove_all(1);
}

/*
 * Return actual state of device to libdevmapper.
 */
int
dm_dev_status_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        const char *name, *uuid;
        uint32_t flags, j, minor;

        name = NULL;
        uuid = NULL;
        flags = 0;
        j = 0;

        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        dm_dbg_print_flags(dmv->flags);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_OPEN, dmv->table_head.io_cnt);
        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);
        prop_dictionary_set_cstring(dm_dict, DM_IOCTL_UUID, dmv->uuid);

        if (dmv->flags & DM_SUSPEND_FLAG)
                dm_add_flag(dm_dict, &flags, DM_SUSPEND_FLAG);

        /*
         * Add status flags for tables I have to check both active and
         * inactive tables.
         */
        if ((j = dm_table_get_target_count(&dmv->table_head, DM_TABLE_ACTIVE)))
                dm_add_flag(dm_dict, &flags, DM_ACTIVE_PRESENT_FLAG);
        else
                dm_remove_flag(dm_dict, &flags, DM_ACTIVE_PRESENT_FLAG);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_TARGET_COUNT, j);

        if (dm_table_get_target_count(&dmv->table_head, DM_TABLE_INACTIVE))
                dm_add_flag(dm_dict, &flags, DM_INACTIVE_PRESENT_FLAG);
        else
                dm_remove_flag(dm_dict, &flags, DM_INACTIVE_PRESENT_FLAG);

        dm_dev_unbusy(dmv);

        return 0;
}

/*
 * Set only flag to suggest that device is suspended. This call is
 * not supported in NetBSD.
 */
int
dm_dev_suspend_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        const char *name, *uuid;
        uint32_t flags, minor;

        name = NULL;
        uuid = NULL;
        flags = 0;

        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        atomic_set_int(&dmv->flags, DM_SUSPEND_FLAG);

        dm_dbg_print_flags(dmv->flags);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_OPEN, dmv->table_head.io_cnt);
        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_FLAGS, dmv->flags);
        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);

        dm_dev_unbusy(dmv);

        /* Add flags to dictionary flag after dmv -> dict copy */
        dm_add_flag(dm_dict, &flags, DM_EXISTS_FLAG);

        return 0;
}

/*
 * Simulate Linux behaviour better and switch tables here and not in
 * dm_table_load_ioctl.
 */
int
dm_dev_resume_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        const char *name, *uuid;
        uint32_t flags, minor;

        name = NULL;
        uuid = NULL;
        flags = 0;

        /*
         * char *xml; xml = prop_dictionary_externalize(dm_dict);
         * kprintf("%s\n",xml);
         */

        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        /* Remove device from global device list */
        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        atomic_clear_int(&dmv->flags, (DM_SUSPEND_FLAG | DM_INACTIVE_PRESENT_FLAG));
        atomic_set_int(&dmv->flags, DM_ACTIVE_PRESENT_FLAG);

        dm_table_switch_tables(&dmv->table_head);

        dm_add_flag(dm_dict, &flags, DM_EXISTS_FLAG);

        dmsetdiskinfo(dmv->diskp, &dmv->table_head);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_OPEN, dmv->table_head.io_cnt);
        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_FLAGS, flags);
        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);

        dm_dev_unbusy(dmv);

        /* Destroy inactive table after resume. */
        dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);

        return 0;
}

/*
 * Table management routines
 * lvm2tools doens't send name/uuid to kernel with table
 * for lookup I have to use minor number.
 */

/*
 * Remove inactive table from device. Routines which work's with inactive tables
 * doesn't need to synchronise with dmstrategy. They can synchronise themselves with mutex?.
 */
int
dm_table_clear_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        const char *name, *uuid;
        uint32_t flags, minor;

        dmv = NULL;
        name = NULL;
        uuid = NULL;
        flags = 0;
        minor = 0;

        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        dmdebug("Clearing inactive table from device: %s--%s\n",
            name, uuid);

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        /* Select unused table */
        dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);

        atomic_clear_int(&dmv->flags, DM_INACTIVE_PRESENT_FLAG);

        dm_dev_unbusy(dmv);

        return 0;
}

/*
 * Get list of physical devices for active table.
 * Get dev_t from pdev vnode and insert it into cmd_array.
 *
 * XXX. This function is called from lvm2tools to get information
 *      about physical devices, too e.g. during vgcreate.
 */
int
dm_table_deps_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        dm_table_t *tbl;
        dm_table_entry_t *table_en;

        prop_array_t cmd_array;
        const char *name, *uuid;
        uint32_t flags, minor;

        int table_type;

        name = NULL;
        uuid = NULL;
        dmv = NULL;
        flags = 0;

        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        /* create array for dev_t's */
        cmd_array = prop_array_create();

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);
        prop_dictionary_set_cstring(dm_dict, DM_IOCTL_NAME, dmv->name);
        prop_dictionary_set_cstring(dm_dict, DM_IOCTL_UUID, dmv->uuid);

        dmdebug("Getting table deps for device: %s\n", dmv->name);

        /*
         * if DM_QUERY_INACTIVE_TABLE_FLAG is passed we need to query
         * INACTIVE TABLE
         */
        if (flags & DM_QUERY_INACTIVE_TABLE_FLAG)
                table_type = DM_TABLE_INACTIVE;
        else
                table_type = DM_TABLE_ACTIVE;

        tbl = dm_table_get_entry(&dmv->table_head, table_type);

        TAILQ_FOREACH(table_en, tbl, next)
                dm_table_deps(table_en, cmd_array);

        dm_table_release(&dmv->table_head, table_type);
        dm_dev_unbusy(dmv);

        prop_dictionary_set(dm_dict, DM_IOCTL_CMD_DATA, cmd_array);
        prop_object_release(cmd_array);

        return 0;
}

static int
dm_table_deps(dm_table_entry_t *table_en, prop_array_t array)
{
        dm_mapping_t *map;
        int i, size;
        uint64_t ret, tmp;

        size = prop_array_count(array);

        TAILQ_FOREACH(map, &table_en->pdev_maps, next) {
                ret = map->data.pdev->udev;
                for (i = 0; i < size; i++) {
                        if (prop_array_get_uint64(array, i, &tmp) == true)
                                if (ret == tmp)
                                        break; /* exists */
                }
                /*
                 * Ignore if the device has already been added by
                 * other tables.
                 */
                if (i == size)
                        prop_array_add_uint64(array, ret);
        }

        return 0;
}

/*
 * Load new table/tables to device.
 * Call apropriate target init routine open all physical pdev's and
 * link them to device. For other targets mirror, strip, snapshot etc.
 *
 * Load table to inactive slot table are switched in dm_device_resume_ioctl.
 * This simulates Linux behaviour better there should not be any difference.
 */
int
dm_table_load_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        dm_table_entry_t *table_en;
        dm_table_t *tbl;
        dm_target_t *target;

        prop_object_iterator_t iter;
        prop_array_t cmd_array;
        prop_dictionary_t target_dict;

        const char *name, *uuid, *type;

        uint32_t flags, ret, minor;

        char *str;

        ret = 0;
        flags = 0;
        name = NULL;
        uuid = NULL;
        dmv = NULL;
        str = NULL;

        /*
         * char *xml; xml = prop_dictionary_externalize(dm_dict);
         * kprintf("%s\n",xml);
         */

        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        cmd_array = prop_dictionary_get(dm_dict, DM_IOCTL_CMD_DATA);
        iter = prop_array_iterator(cmd_array);
        dm_dbg_print_flags(flags);

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        dmdebug("Loading table to device: %s--%d\n", name,
            dmv->table_head.cur_active_table);

        /*
         * I have to check if this table slot is not used by another table list.
         * if it is used I should free them.
         */
        if (dmv->flags & DM_INACTIVE_PRESENT_FLAG)
                dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);

        dm_dbg_print_flags(dmv->flags);
        tbl = dm_table_get_entry(&dmv->table_head, DM_TABLE_INACTIVE);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);

        while ((target_dict = prop_object_iterator_next(iter)) != NULL) {
                prop_dictionary_get_cstring_nocopy(target_dict,
                    DM_TABLE_TYPE, &type);
                /*
                 * If we want to deny table with 2 or more different
                 * target we should do it here
                 */
                if (((target = dm_target_lookup(type)) == NULL) &&
                    ((target = dm_target_autoload(type)) == NULL)) {
                        dm_table_release(&dmv->table_head, DM_TABLE_INACTIVE);
                        dm_dev_unbusy(dmv);
                        return ENOENT;
                }
                if ((table_en = kmalloc(sizeof(dm_table_entry_t),
                            M_DM, M_WAITOK)) == NULL) {
                        dm_table_release(&dmv->table_head, DM_TABLE_INACTIVE);
                        dm_dev_unbusy(dmv);
                        dm_target_unbusy(target);
                        return ENOMEM;
                }
                prop_dictionary_get_uint64(target_dict, DM_TABLE_START,
                    &table_en->start);
                prop_dictionary_get_uint64(target_dict, DM_TABLE_LENGTH,
                    &table_en->length);

                dmdebug("table_en->start = %ju, table_en->length = %ju\n",
                        (uintmax_t)table_en->start,
                        (uintmax_t)table_en->length);

                table_en->target = target;
                table_en->dev = dmv;
                table_en->target_config = NULL;
                TAILQ_INIT(&table_en->pdev_maps);

                /*
                 * There is a parameter string after dm_target_spec
                 * structure which  points to /dev/wd0a 284 part of
                 * table. String str points to this text. This can be
                 * null and therefore it should be checked before we try to
                 * use it.
                 */
                prop_dictionary_get_cstring(target_dict,
                    DM_TABLE_PARAMS, &str);

                TAILQ_INSERT_TAIL(tbl, table_en, next);

                /*
                 * Params string is different for every target,
                 * therfore I have to pass it to target init
                 * routine and parse parameters there.
                 */
                dmdebug("String passed in is: \"%s\"\n", str);

                if ((ret = dm_table_init(target, table_en, str)) != 0) {
                        dm_table_release(&dmv->table_head, DM_TABLE_INACTIVE);
                        dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
                        kfree(str, M_TEMP);

                        dm_dev_unbusy(dmv);
                        return ret;
                }
                kfree(str, M_TEMP);
        }
        prop_object_iterator_release(iter);

        dm_add_flag(dm_dict, &flags, DM_INACTIVE_PRESENT_FLAG);
        atomic_set_int(&dmv->flags, DM_INACTIVE_PRESENT_FLAG);

        dm_table_release(&dmv->table_head, DM_TABLE_INACTIVE);

        dm_dev_unbusy(dmv);
#if 0
        dmsetdiskinfo(dmv->diskp, &dmv->table_head);
#endif
        return 0;
}

static int
dm_table_init(dm_target_t *target, dm_table_entry_t *table_en, char *params)
{
        int i, n, argc;
        int ret = 0;
        char **ap, **argv;

        if (params == NULL)
                return EINVAL;

        n = target->max_argc;
        if (n) {
                dmdebug("Max argc %d for %s target\n", n, target->name);
        } else {
                n = 20;  /* large enough slots for most targets */
        }

        argv = kmalloc(sizeof(*argv) * n, M_DM, M_WAITOK | M_ZERO);

        for (ap = argv;
             ap < &argv[n] && (*ap = strsep(&params, " \t")) != NULL;) {
                if (**ap != '\0')
                        ap++;
        }
        argc = ap - argv;

        if (dm_debug_level) {
                for (i = 0; i < argc; i++)
                        kprintf("DM: argv[%d] = \"%s\"\n", i, argv[i]);
        }

        if (target->init)
                ret = target->init(table_en, argc, argv);

        kfree(argv, M_DM);

        return ret;
}

/*
 * Get description of all tables loaded to device from kernel
 * and send it to libdevmapper.
 *
 * Output dictionary for every table:
 *
 * <key>cmd_data</key>
 * <array>
 *   <dict>
 *    <key>type<key>
 *    <string>...</string>
 *
 *    <key>start</key>
 *    <integer>...</integer>
 *
 *    <key>length</key>
 *    <integer>...</integer>
 *
 *    <key>params</key>
 *    <string>...</string>
 *   </dict>
 * </array>
 */
int
dm_table_status_ioctl(prop_dictionary_t dm_dict)
{
        dm_dev_t *dmv;
        dm_table_t *tbl;
        dm_table_entry_t *table_en;

        prop_array_t cmd_array;
        prop_dictionary_t target_dict;

        uint32_t minor;

        const char *name, *uuid;
        uint32_t flags;
        int table_type;

        dmv = NULL;
        uuid = NULL;
        name = NULL;
        flags = 0;

        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);

        cmd_array = prop_array_create();

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }
        /*
         * if DM_QUERY_INACTIVE_TABLE_FLAG is passed we need to query
         * INACTIVE TABLE
         */
        if (flags & DM_QUERY_INACTIVE_TABLE_FLAG)
                table_type = DM_TABLE_INACTIVE;
        else
                table_type = DM_TABLE_ACTIVE;

        if (dm_table_get_target_count(&dmv->table_head, DM_TABLE_ACTIVE))
                dm_add_flag(dm_dict, &flags, DM_ACTIVE_PRESENT_FLAG);
        else {
                dm_remove_flag(dm_dict, &flags, DM_ACTIVE_PRESENT_FLAG);

                if (dm_table_get_target_count(&dmv->table_head, DM_TABLE_INACTIVE))
                        dm_add_flag(dm_dict, &flags, DM_INACTIVE_PRESENT_FLAG);
                else
                        dm_remove_flag(dm_dict, &flags, DM_INACTIVE_PRESENT_FLAG);
        }

        if (dmv->flags & DM_SUSPEND_FLAG)
                dm_add_flag(dm_dict, &flags, DM_SUSPEND_FLAG);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_MINOR, dmv->minor);

        dmdebug("Status of device tables: %s--%d\n",
            name, dmv->table_head.cur_active_table);

        tbl = dm_table_get_entry(&dmv->table_head, table_type);

        TAILQ_FOREACH(table_en, tbl, next) {
                target_dict = prop_dictionary_create();
                dmdebug("%016" PRIu64 ", length %016" PRIu64
                    ", target %s\n", table_en->start, table_en->length,
                    table_en->target->name);

                prop_dictionary_set_uint64(target_dict, DM_TABLE_START,
                    table_en->start);
                prop_dictionary_set_uint64(target_dict, DM_TABLE_LENGTH,
                    table_en->length);

                prop_dictionary_set_cstring(target_dict, DM_TABLE_TYPE,
                    table_en->target->name);

                /* dm_table_get_cur_actv.table ?? */
                prop_dictionary_set_int32(target_dict, DM_TABLE_STAT,
                    dmv->table_head.cur_active_table);

                dm_table_status(table_en, target_dict, flags);

                prop_array_add(cmd_array, target_dict);
                prop_object_release(target_dict);
        }

        dm_table_release(&dmv->table_head, table_type);
        dm_dev_unbusy(dmv);

        prop_dictionary_set_uint32(dm_dict, DM_IOCTL_FLAGS, flags);
        prop_dictionary_set(dm_dict, DM_IOCTL_CMD_DATA, cmd_array);
        prop_object_release(cmd_array);

        return 0;
}

static int
dm_table_status(dm_table_entry_t *table_en,
        prop_dictionary_t target_dict, uint32_t flags)
{
        void *cfg;
        char *params;
        int is_table;

        cfg = table_en->target_config;
        params = NULL;

        is_table = (flags & DM_STATUS_TABLE_FLAG) ? 1 : 0;

        if (is_table && table_en->target->table) {
                params = table_en->target->table(cfg);
        } else if (!is_table && table_en->target->info) {
                params = table_en->target->info(cfg);
        } else {
                prop_dictionary_set_cstring(target_dict, DM_TABLE_PARAMS, "");
                return ENOTSUP;
        }

        if (params == NULL) {
                prop_dictionary_set_cstring(target_dict, DM_TABLE_PARAMS, "");
                return ENOMEM;
        }

        prop_dictionary_set_cstring(target_dict, DM_TABLE_PARAMS, params);
        kfree(params, M_DM);
        return 0;
}

int
dm_message_ioctl(prop_dictionary_t dm_dict)
{
        dm_table_t  *tbl;
        dm_table_entry_t *table_en;
        dm_dev_t *dmv;
        const char *name, *uuid;
        uint32_t flags, minor;
        uint64_t table_start, table_end, sector;
        char *msg;
        int ret, found = 0;

        flags = 0;
        name = NULL;
        uuid = NULL;

        /* Get needed values from dictionary. */
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_NAME, &name);
        prop_dictionary_get_cstring_nocopy(dm_dict, DM_IOCTL_UUID, &uuid);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_FLAGS, &flags);
        prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);
        prop_dictionary_get_uint64(dm_dict, DM_MESSAGE_SECTOR, &sector);

        dm_dbg_print_flags(flags);

        if ((dmv = dm_dev_lookup(name, uuid, minor)) == NULL) {
                dm_remove_flag(dm_dict, &flags, DM_EXISTS_FLAG);
                return ENOENT;
        }

        /* Get message string */
        prop_dictionary_get_cstring(dm_dict, DM_MESSAGE_STR, &msg);

        tbl = dm_table_get_entry(&dmv->table_head, DM_TABLE_ACTIVE);

        ret = EINVAL;

        if (sector == 0) {
                if (!TAILQ_EMPTY(tbl)) {
                        table_en = TAILQ_FIRST(tbl);
                        found = 1;
                }
        } else {
                TAILQ_FOREACH(table_en, tbl, next) {
                        table_start = table_en->start;
                        table_end = table_start + table_en->length;

                        if ((sector >= table_start) && (sector < table_end)) {
                                found = 1;
                                break;
                        }
                }
        }

        if (found) {
                if (table_en->target->message != NULL)
                        ret = table_en->target->message(table_en, msg);
        }

        dm_table_release(&dmv->table_head, DM_TABLE_ACTIVE);

        kfree(msg, M_TEMP);
        dm_dev_unbusy(dmv);

        return ret;
}

/*
 * For every call I have to set kernel driver version.
 * Because I can have commands supported only in other
 * newer/later version. This routine is called for every
 * ioctl command.
 */
int
dm_check_version(prop_dictionary_t dm_dict)
{
        size_t i;
        int dm_version[3];
        prop_array_t ver;

        ver = prop_dictionary_get(dm_dict, DM_IOCTL_VERSION);

        for (i = 0; i < 3; i++)
                prop_array_get_uint32(ver, i, &dm_version[i]);

        if (DM_VERSION_MAJOR != dm_version[0] || DM_VERSION_MINOR < dm_version[1]) {
                dmdebug("libdevmapper/kernel version mismatch "
                    "kernel: %d.%d.%d libdevmapper: %d.%d.%d\n",
                    DM_VERSION_MAJOR, DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL,
                    dm_version[0], dm_version[1], dm_version[2]);

                return EIO;
        }
        prop_array_set_uint32(ver, 0, DM_VERSION_MAJOR);
        prop_array_set_uint32(ver, 1, DM_VERSION_MINOR);
        prop_array_set_uint32(ver, 2, DM_VERSION_PATCHLEVEL);

        prop_dictionary_set(dm_dict, DM_IOCTL_VERSION, ver);

        return 0;
}