OpenZFS 6931 - lib/libzfs: cleanup gcc warnings

[mirror_zfs.git] / lib / libzfs / libzfs_pool.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
 * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
 */

#include <ctype.h>
#include <errno.h>
#include <devid.h>
#include <fcntl.h>
#include <libintl.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <libgen.h>
#include <zone.h>
#include <sys/stat.h>
#include <sys/efi_partition.h>
#include <sys/vtoc.h>
#include <sys/zfs_ioctl.h>
#include <dlfcn.h>

#include "zfs_namecheck.h"
#include "zfs_prop.h"
#include "libzfs_impl.h"
#include "zfs_comutil.h"
#include "zfeature_common.h"

static int read_efi_label(nvlist_t *config, diskaddr_t *sb);

typedef struct prop_flags {
        int create:1;   /* Validate property on creation */
        int import:1;   /* Validate property on import */
} prop_flags_t;

/*
 * ====================================================================
 *   zpool property functions
 * ====================================================================
 */

static int
zpool_get_all_props(zpool_handle_t *zhp)
{
        zfs_cmd_t zc = {"\0"};
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));

        if (zcmd_alloc_dst_nvlist(hdl, &zc, 0) != 0)
                return (-1);

        while (ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_GET_PROPS, &zc) != 0) {
                if (errno == ENOMEM) {
                        if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
                                zcmd_free_nvlists(&zc);
                                return (-1);
                        }
                } else {
                        zcmd_free_nvlists(&zc);
                        return (-1);
                }
        }

        if (zcmd_read_dst_nvlist(hdl, &zc, &zhp->zpool_props) != 0) {
                zcmd_free_nvlists(&zc);
                return (-1);
        }

        zcmd_free_nvlists(&zc);

        return (0);
}

static int
zpool_props_refresh(zpool_handle_t *zhp)
{
        nvlist_t *old_props;

        old_props = zhp->zpool_props;

        if (zpool_get_all_props(zhp) != 0)
                return (-1);

        nvlist_free(old_props);
        return (0);
}

static char *
zpool_get_prop_string(zpool_handle_t *zhp, zpool_prop_t prop,
    zprop_source_t *src)
{
        nvlist_t *nv, *nvl;
        uint64_t ival;
        char *value;
        zprop_source_t source;

        nvl = zhp->zpool_props;
        if (nvlist_lookup_nvlist(nvl, zpool_prop_to_name(prop), &nv) == 0) {
                verify(nvlist_lookup_uint64(nv, ZPROP_SOURCE, &ival) == 0);
                source = ival;
                verify(nvlist_lookup_string(nv, ZPROP_VALUE, &value) == 0);
        } else {
                source = ZPROP_SRC_DEFAULT;
                if ((value = (char *)zpool_prop_default_string(prop)) == NULL)
                        value = "-";
        }

        if (src)
                *src = source;

        return (value);
}

uint64_t
zpool_get_prop_int(zpool_handle_t *zhp, zpool_prop_t prop, zprop_source_t *src)
{
        nvlist_t *nv, *nvl;
        uint64_t value;
        zprop_source_t source;

        if (zhp->zpool_props == NULL && zpool_get_all_props(zhp)) {
                /*
                 * zpool_get_all_props() has most likely failed because
                 * the pool is faulted, but if all we need is the top level
                 * vdev's guid then get it from the zhp config nvlist.
                 */
                if ((prop == ZPOOL_PROP_GUID) &&
                    (nvlist_lookup_nvlist(zhp->zpool_config,
                    ZPOOL_CONFIG_VDEV_TREE, &nv) == 0) &&
                    (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &value)
                    == 0)) {
                        return (value);
                }
                return (zpool_prop_default_numeric(prop));
        }

        nvl = zhp->zpool_props;
        if (nvlist_lookup_nvlist(nvl, zpool_prop_to_name(prop), &nv) == 0) {
                verify(nvlist_lookup_uint64(nv, ZPROP_SOURCE, &value) == 0);
                source = value;
                verify(nvlist_lookup_uint64(nv, ZPROP_VALUE, &value) == 0);
        } else {
                source = ZPROP_SRC_DEFAULT;
                value = zpool_prop_default_numeric(prop);
        }

        if (src)
                *src = source;

        return (value);
}

/*
 * Map VDEV STATE to printed strings.
 */
char *
zpool_state_to_name(vdev_state_t state, vdev_aux_t aux)
{
        switch (state) {
        case VDEV_STATE_CLOSED:
        case VDEV_STATE_OFFLINE:
                return (gettext("OFFLINE"));
        case VDEV_STATE_REMOVED:
                return (gettext("REMOVED"));
        case VDEV_STATE_CANT_OPEN:
                if (aux == VDEV_AUX_CORRUPT_DATA || aux == VDEV_AUX_BAD_LOG)
                        return (gettext("FAULTED"));
                else if (aux == VDEV_AUX_SPLIT_POOL)
                        return (gettext("SPLIT"));
                else
                        return (gettext("UNAVAIL"));
        case VDEV_STATE_FAULTED:
                return (gettext("FAULTED"));
        case VDEV_STATE_DEGRADED:
                return (gettext("DEGRADED"));
        case VDEV_STATE_HEALTHY:
                return (gettext("ONLINE"));

        default:
                break;
        }

        return (gettext("UNKNOWN"));
}

/*
 * Map POOL STATE to printed strings.
 */
const char *
zpool_pool_state_to_name(pool_state_t state)
{
        switch (state) {
        default:
                break;
        case POOL_STATE_ACTIVE:
                return (gettext("ACTIVE"));
        case POOL_STATE_EXPORTED:
                return (gettext("EXPORTED"));
        case POOL_STATE_DESTROYED:
                return (gettext("DESTROYED"));
        case POOL_STATE_SPARE:
                return (gettext("SPARE"));
        case POOL_STATE_L2CACHE:
                return (gettext("L2CACHE"));
        case POOL_STATE_UNINITIALIZED:
                return (gettext("UNINITIALIZED"));
        case POOL_STATE_UNAVAIL:
                return (gettext("UNAVAIL"));
        case POOL_STATE_POTENTIALLY_ACTIVE:
                return (gettext("POTENTIALLY_ACTIVE"));
        }

        return (gettext("UNKNOWN"));
}

/*
 * Get a zpool property value for 'prop' and return the value in
 * a pre-allocated buffer.
 */
int
zpool_get_prop(zpool_handle_t *zhp, zpool_prop_t prop, char *buf,
    size_t len, zprop_source_t *srctype, boolean_t literal)
{
        uint64_t intval;
        const char *strval;
        zprop_source_t src = ZPROP_SRC_NONE;
        nvlist_t *nvroot;
        vdev_stat_t *vs;
        uint_t vsc;

        if (zpool_get_state(zhp) == POOL_STATE_UNAVAIL) {
                switch (prop) {
                case ZPOOL_PROP_NAME:
                        (void) strlcpy(buf, zpool_get_name(zhp), len);
                        break;

                case ZPOOL_PROP_HEALTH:
                        (void) strlcpy(buf, "FAULTED", len);
                        break;

                case ZPOOL_PROP_GUID:
                        intval = zpool_get_prop_int(zhp, prop, &src);
                        (void) snprintf(buf, len, "%llu", (u_longlong_t)intval);
                        break;

                case ZPOOL_PROP_ALTROOT:
                case ZPOOL_PROP_CACHEFILE:
                case ZPOOL_PROP_COMMENT:
                        if (zhp->zpool_props != NULL ||
                            zpool_get_all_props(zhp) == 0) {
                                (void) strlcpy(buf,
                                    zpool_get_prop_string(zhp, prop, &src),
                                    len);
                                break;
                        }
                        /* FALLTHROUGH */
                default:
                        (void) strlcpy(buf, "-", len);
                        break;
                }

                if (srctype != NULL)
                        *srctype = src;
                return (0);
        }

        if (zhp->zpool_props == NULL && zpool_get_all_props(zhp) &&
            prop != ZPOOL_PROP_NAME)
                return (-1);

        switch (zpool_prop_get_type(prop)) {
        case PROP_TYPE_STRING:
                (void) strlcpy(buf, zpool_get_prop_string(zhp, prop, &src),
                    len);
                break;

        case PROP_TYPE_NUMBER:
                intval = zpool_get_prop_int(zhp, prop, &src);

                switch (prop) {
                case ZPOOL_PROP_SIZE:
                case ZPOOL_PROP_ALLOCATED:
                case ZPOOL_PROP_FREE:
                case ZPOOL_PROP_FREEING:
                case ZPOOL_PROP_LEAKED:
                case ZPOOL_PROP_ASHIFT:
                        if (literal)
                                (void) snprintf(buf, len, "%llu",
                                    (u_longlong_t)intval);
                        else
                                (void) zfs_nicenum(intval, buf, len);
                        break;

                case ZPOOL_PROP_EXPANDSZ:
                        if (intval == 0) {
                                (void) strlcpy(buf, "-", len);
                        } else if (literal) {
                                (void) snprintf(buf, len, "%llu",
                                    (u_longlong_t)intval);
                        } else {
                                (void) zfs_nicenum(intval, buf, len);
                        }
                        break;

                case ZPOOL_PROP_CAPACITY:
                        if (literal) {
                                (void) snprintf(buf, len, "%llu",
                                    (u_longlong_t)intval);
                        } else {
                                (void) snprintf(buf, len, "%llu%%",
                                    (u_longlong_t)intval);
                        }
                        break;

                case ZPOOL_PROP_FRAGMENTATION:
                        if (intval == UINT64_MAX) {
                                (void) strlcpy(buf, "-", len);
                        } else if (literal) {
                                (void) snprintf(buf, len, "%llu",
                                    (u_longlong_t)intval);
                        } else {
                                (void) snprintf(buf, len, "%llu%%",
                                    (u_longlong_t)intval);
                        }
                        break;

                case ZPOOL_PROP_DEDUPRATIO:
                        if (literal)
                                (void) snprintf(buf, len, "%llu.%02llu",
                                    (u_longlong_t)(intval / 100),
                                    (u_longlong_t)(intval % 100));
                        else
                                (void) snprintf(buf, len, "%llu.%02llux",
                                    (u_longlong_t)(intval / 100),
                                    (u_longlong_t)(intval % 100));
                        break;

                case ZPOOL_PROP_HEALTH:
                        verify(nvlist_lookup_nvlist(zpool_get_config(zhp, NULL),
                            ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
                        verify(nvlist_lookup_uint64_array(nvroot,
                            ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
                            == 0);

                        (void) strlcpy(buf, zpool_state_to_name(intval,
                            vs->vs_aux), len);
                        break;
                case ZPOOL_PROP_VERSION:
                        if (intval >= SPA_VERSION_FEATURES) {
                                (void) snprintf(buf, len, "-");
                                break;
                        }
                        /* FALLTHROUGH */
                default:
                        (void) snprintf(buf, len, "%llu", (u_longlong_t)intval);
                }
                break;

        case PROP_TYPE_INDEX:
                intval = zpool_get_prop_int(zhp, prop, &src);
                if (zpool_prop_index_to_string(prop, intval, &strval)
                    != 0)
                        return (-1);
                (void) strlcpy(buf, strval, len);
                break;

        default:
                abort();
        }

        if (srctype)
                *srctype = src;

        return (0);
}

/*
 * Check if the bootfs name has the same pool name as it is set to.
 * Assuming bootfs is a valid dataset name.
 */
static boolean_t
bootfs_name_valid(const char *pool, char *bootfs)
{
        int len = strlen(pool);

        if (!zfs_name_valid(bootfs, ZFS_TYPE_FILESYSTEM|ZFS_TYPE_SNAPSHOT))
                return (B_FALSE);

        if (strncmp(pool, bootfs, len) == 0 &&
            (bootfs[len] == '/' || bootfs[len] == '\0'))
                return (B_TRUE);

        return (B_FALSE);
}

boolean_t
zpool_is_bootable(zpool_handle_t *zhp)
{
        char bootfs[ZFS_MAX_DATASET_NAME_LEN];

        return (zpool_get_prop(zhp, ZPOOL_PROP_BOOTFS, bootfs,
            sizeof (bootfs), NULL, B_FALSE) == 0 && strncmp(bootfs, "-",
            sizeof (bootfs)) != 0);
}


/*
 * Given an nvlist of zpool properties to be set, validate that they are
 * correct, and parse any numeric properties (index, boolean, etc) if they are
 * specified as strings.
 */
static nvlist_t *
zpool_valid_proplist(libzfs_handle_t *hdl, const char *poolname,
    nvlist_t *props, uint64_t version, prop_flags_t flags, char *errbuf)
{
        nvpair_t *elem;
        nvlist_t *retprops;
        zpool_prop_t prop;
        char *strval;
        uint64_t intval;
        char *slash, *check;
        struct stat64 statbuf;
        zpool_handle_t *zhp;

        if (nvlist_alloc(&retprops, NV_UNIQUE_NAME, 0) != 0) {
                (void) no_memory(hdl);
                return (NULL);
        }

        elem = NULL;
        while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
                const char *propname = nvpair_name(elem);

                prop = zpool_name_to_prop(propname);
                if (prop == ZPROP_INVAL && zpool_prop_feature(propname)) {
                        int err;
                        char *fname = strchr(propname, '@') + 1;

                        err = zfeature_lookup_name(fname, NULL);
                        if (err != 0) {
                                ASSERT3U(err, ==, ENOENT);
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "invalid feature '%s'"), fname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        if (nvpair_type(elem) != DATA_TYPE_STRING) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "'%s' must be a string"), propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        (void) nvpair_value_string(elem, &strval);
                        if (strcmp(strval, ZFS_FEATURE_ENABLED) != 0 &&
                            strcmp(strval, ZFS_FEATURE_DISABLED) != 0) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' can only be set to "
                                    "'enabled' or 'disabled'"), propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        if (nvlist_add_uint64(retprops, propname, 0) != 0) {
                                (void) no_memory(hdl);
                                goto error;
                        }
                        continue;
                }

                /*
                 * Make sure this property is valid and applies to this type.
                 */
                if (prop == ZPROP_INVAL) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "invalid property '%s'"), propname);
                        (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                        goto error;
                }

                if (zpool_prop_readonly(prop)) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "'%s' "
                            "is readonly"), propname);
                        (void) zfs_error(hdl, EZFS_PROPREADONLY, errbuf);
                        goto error;
                }

                if (zprop_parse_value(hdl, elem, prop, ZFS_TYPE_POOL, retprops,
                    &strval, &intval, errbuf) != 0)
                        goto error;

                /*
                 * Perform additional checking for specific properties.
                 */
                switch (prop) {
                case ZPOOL_PROP_VERSION:
                        if (intval < version ||
                            !SPA_VERSION_IS_SUPPORTED(intval)) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' number %d is invalid."),
                                    propname, intval);
                                (void) zfs_error(hdl, EZFS_BADVERSION, errbuf);
                                goto error;
                        }
                        break;

                case ZPOOL_PROP_ASHIFT:
                        if (!flags.create) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' can only be set at "
                                    "creation time"), propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        if (intval != 0 && (intval < 9 || intval > 13)) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' number %d is invalid."),
                                    propname, intval);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }
                        break;

                case ZPOOL_PROP_BOOTFS:
                        if (flags.create || flags.import) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' cannot be set at creation "
                                    "or import time"), propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        if (version < SPA_VERSION_BOOTFS) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "pool must be upgraded to support "
                                    "'%s' property"), propname);
                                (void) zfs_error(hdl, EZFS_BADVERSION, errbuf);
                                goto error;
                        }

                        /*
                         * bootfs property value has to be a dataset name and
                         * the dataset has to be in the same pool as it sets to.
                         */
                        if (strval[0] != '\0' && !bootfs_name_valid(poolname,
                            strval)) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "'%s' "
                                    "is an invalid name"), strval);
                                (void) zfs_error(hdl, EZFS_INVALIDNAME, errbuf);
                                goto error;
                        }

                        if ((zhp = zpool_open_canfail(hdl, poolname)) == NULL) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "could not open pool '%s'"), poolname);
                                (void) zfs_error(hdl, EZFS_OPENFAILED, errbuf);
                                goto error;
                        }
                        zpool_close(zhp);
                        break;

                case ZPOOL_PROP_ALTROOT:
                        if (!flags.create && !flags.import) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' can only be set during pool "
                                    "creation or import"), propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        if (strval[0] != '/') {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "bad alternate root '%s'"), strval);
                                (void) zfs_error(hdl, EZFS_BADPATH, errbuf);
                                goto error;
                        }
                        break;

                case ZPOOL_PROP_CACHEFILE:
                        if (strval[0] == '\0')
                                break;

                        if (strcmp(strval, "none") == 0)
                                break;

                        if (strval[0] != '/') {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' must be empty, an "
                                    "absolute path, or 'none'"), propname);
                                (void) zfs_error(hdl, EZFS_BADPATH, errbuf);
                                goto error;
                        }

                        slash = strrchr(strval, '/');

                        if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
                            strcmp(slash, "/..") == 0) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "'%s' is not a valid file"), strval);
                                (void) zfs_error(hdl, EZFS_BADPATH, errbuf);
                                goto error;
                        }

                        *slash = '\0';

                        if (strval[0] != '\0' &&
                            (stat64(strval, &statbuf) != 0 ||
                            !S_ISDIR(statbuf.st_mode))) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "'%s' is not a valid directory"),
                                    strval);
                                (void) zfs_error(hdl, EZFS_BADPATH, errbuf);
                                goto error;
                        }

                        *slash = '/';
                        break;

                case ZPOOL_PROP_COMMENT:
                        for (check = strval; *check != '\0'; check++) {
                                if (!isprint(*check)) {
                                        zfs_error_aux(hdl,
                                            dgettext(TEXT_DOMAIN,
                                            "comment may only have printable "
                                            "characters"));
                                        (void) zfs_error(hdl, EZFS_BADPROP,
                                            errbuf);
                                        goto error;
                                }
                        }
                        if (strlen(strval) > ZPROP_MAX_COMMENT) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "comment must not exceed %d characters"),
                                    ZPROP_MAX_COMMENT);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }
                        break;
                case ZPOOL_PROP_READONLY:
                        if (!flags.import) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' can only be set at "
                                    "import time"), propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }
                        break;
                case ZPOOL_PROP_TNAME:
                        if (!flags.create) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property '%s' can only be set at "
                                    "creation time"), propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                default:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "property '%s'(%d) not defined"), propname, prop);
                        break;
                }
        }

        return (retprops);
error:
        nvlist_free(retprops);
        return (NULL);
}

/*
 * Set zpool property : propname=propval.
 */
int
zpool_set_prop(zpool_handle_t *zhp, const char *propname, const char *propval)
{
        zfs_cmd_t zc = {"\0"};
        int ret = -1;
        char errbuf[1024];
        nvlist_t *nvl = NULL;
        nvlist_t *realprops;
        uint64_t version;
        prop_flags_t flags = { 0 };

        (void) snprintf(errbuf, sizeof (errbuf),
            dgettext(TEXT_DOMAIN, "cannot set property for '%s'"),
            zhp->zpool_name);

        if (nvlist_alloc(&nvl, NV_UNIQUE_NAME, 0) != 0)
                return (no_memory(zhp->zpool_hdl));

        if (nvlist_add_string(nvl, propname, propval) != 0) {
                nvlist_free(nvl);
                return (no_memory(zhp->zpool_hdl));
        }

        version = zpool_get_prop_int(zhp, ZPOOL_PROP_VERSION, NULL);
        if ((realprops = zpool_valid_proplist(zhp->zpool_hdl,
            zhp->zpool_name, nvl, version, flags, errbuf)) == NULL) {
                nvlist_free(nvl);
                return (-1);
        }

        nvlist_free(nvl);
        nvl = realprops;

        /*
         * Execute the corresponding ioctl() to set this property.
         */
        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));

        if (zcmd_write_src_nvlist(zhp->zpool_hdl, &zc, nvl) != 0) {
                nvlist_free(nvl);
                return (-1);
        }

        ret = zfs_ioctl(zhp->zpool_hdl, ZFS_IOC_POOL_SET_PROPS, &zc);

        zcmd_free_nvlists(&zc);
        nvlist_free(nvl);

        if (ret)
                (void) zpool_standard_error(zhp->zpool_hdl, errno, errbuf);
        else
                (void) zpool_props_refresh(zhp);

        return (ret);
}

int
zpool_expand_proplist(zpool_handle_t *zhp, zprop_list_t **plp)
{
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        zprop_list_t *entry;
        char buf[ZFS_MAXPROPLEN];
        nvlist_t *features = NULL;
        nvpair_t *nvp;
        zprop_list_t **last;
        boolean_t firstexpand = (NULL == *plp);
        int i;

        if (zprop_expand_list(hdl, plp, ZFS_TYPE_POOL) != 0)
                return (-1);

        last = plp;
        while (*last != NULL)
                last = &(*last)->pl_next;

        if ((*plp)->pl_all)
                features = zpool_get_features(zhp);

        if ((*plp)->pl_all && firstexpand) {
                for (i = 0; i < SPA_FEATURES; i++) {
                        zprop_list_t *entry = zfs_alloc(hdl,
                            sizeof (zprop_list_t));
                        entry->pl_prop = ZPROP_INVAL;
                        entry->pl_user_prop = zfs_asprintf(hdl, "feature@%s",
                            spa_feature_table[i].fi_uname);
                        entry->pl_width = strlen(entry->pl_user_prop);
                        entry->pl_all = B_TRUE;

                        *last = entry;
                        last = &entry->pl_next;
                }
        }

        /* add any unsupported features */
        for (nvp = nvlist_next_nvpair(features, NULL);
            nvp != NULL; nvp = nvlist_next_nvpair(features, nvp)) {
                char *propname;
                boolean_t found;
                zprop_list_t *entry;

                if (zfeature_is_supported(nvpair_name(nvp)))
                        continue;

                propname = zfs_asprintf(hdl, "unsupported@%s",
                    nvpair_name(nvp));

                /*
                 * Before adding the property to the list make sure that no
                 * other pool already added the same property.
                 */
                found = B_FALSE;
                entry = *plp;
                while (entry != NULL) {
                        if (entry->pl_user_prop != NULL &&
                            strcmp(propname, entry->pl_user_prop) == 0) {
                                found = B_TRUE;
                                break;
                        }
                        entry = entry->pl_next;
                }
                if (found) {
                        free(propname);
                        continue;
                }

                entry = zfs_alloc(hdl, sizeof (zprop_list_t));
                entry->pl_prop = ZPROP_INVAL;
                entry->pl_user_prop = propname;
                entry->pl_width = strlen(entry->pl_user_prop);
                entry->pl_all = B_TRUE;

                *last = entry;
                last = &entry->pl_next;
        }

        for (entry = *plp; entry != NULL; entry = entry->pl_next) {

                if (entry->pl_fixed)
                        continue;

                if (entry->pl_prop != ZPROP_INVAL &&
                    zpool_get_prop(zhp, entry->pl_prop, buf, sizeof (buf),
                    NULL, B_FALSE) == 0) {
                        if (strlen(buf) > entry->pl_width)
                                entry->pl_width = strlen(buf);
                }
        }

        return (0);
}

/*
 * Get the state for the given feature on the given ZFS pool.
 */
int
zpool_prop_get_feature(zpool_handle_t *zhp, const char *propname, char *buf,
    size_t len)
{
        uint64_t refcount;
        boolean_t found = B_FALSE;
        nvlist_t *features = zpool_get_features(zhp);
        boolean_t supported;
        const char *feature = strchr(propname, '@') + 1;

        supported = zpool_prop_feature(propname);
        ASSERT(supported || zpool_prop_unsupported(propname));

        /*
         * Convert from feature name to feature guid. This conversion is
         * unnecessary for unsupported@... properties because they already
         * use guids.
         */
        if (supported) {
                int ret;
                spa_feature_t fid;

                ret = zfeature_lookup_name(feature, &fid);
                if (ret != 0) {
                        (void) strlcpy(buf, "-", len);
                        return (ENOTSUP);
                }
                feature = spa_feature_table[fid].fi_guid;
        }

        if (nvlist_lookup_uint64(features, feature, &refcount) == 0)
                found = B_TRUE;

        if (supported) {
                if (!found) {
                        (void) strlcpy(buf, ZFS_FEATURE_DISABLED, len);
                } else  {
                        if (refcount == 0)
                                (void) strlcpy(buf, ZFS_FEATURE_ENABLED, len);
                        else
                                (void) strlcpy(buf, ZFS_FEATURE_ACTIVE, len);
                }
        } else {
                if (found) {
                        if (refcount == 0) {
                                (void) strcpy(buf, ZFS_UNSUPPORTED_INACTIVE);
                        } else {
                                (void) strcpy(buf, ZFS_UNSUPPORTED_READONLY);
                        }
                } else {
                        (void) strlcpy(buf, "-", len);
                        return (ENOTSUP);
                }
        }

        return (0);
}

/*
 * Don't start the slice at the default block of 34; many storage
 * devices will use a stripe width of 128k, other vendors prefer a 1m
 * alignment.  It is best to play it safe and ensure a 1m alignment
 * given 512B blocks.  When the block size is larger by a power of 2
 * we will still be 1m aligned.  Some devices are sensitive to the
 * partition ending alignment as well.
 */
#define NEW_START_BLOCK         2048
#define PARTITION_END_ALIGNMENT 2048

/*
 * Validate the given pool name, optionally putting an extended error message in
 * 'buf'.
 */
boolean_t
zpool_name_valid(libzfs_handle_t *hdl, boolean_t isopen, const char *pool)
{
        namecheck_err_t why;
        char what;
        int ret;

        ret = pool_namecheck(pool, &why, &what);

        /*
         * The rules for reserved pool names were extended at a later point.
         * But we need to support users with existing pools that may now be
         * invalid.  So we only check for this expanded set of names during a
         * create (or import), and only in userland.
         */
        if (ret == 0 && !isopen &&
            (strncmp(pool, "mirror", 6) == 0 ||
            strncmp(pool, "raidz", 5) == 0 ||
            strncmp(pool, "spare", 5) == 0 ||
            strcmp(pool, "log") == 0)) {
                if (hdl != NULL)
                        zfs_error_aux(hdl,
                            dgettext(TEXT_DOMAIN, "name is reserved"));
                return (B_FALSE);
        }


        if (ret != 0) {
                if (hdl != NULL) {
                        switch (why) {
                        case NAME_ERR_TOOLONG:
                                zfs_error_aux(hdl,
                                    dgettext(TEXT_DOMAIN, "name is too long"));
                                break;

                        case NAME_ERR_INVALCHAR:
                                zfs_error_aux(hdl,
                                    dgettext(TEXT_DOMAIN, "invalid character "
                                    "'%c' in pool name"), what);
                                break;

                        case NAME_ERR_NOLETTER:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "name must begin with a letter"));
                                break;

                        case NAME_ERR_RESERVED:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "name is reserved"));
                                break;

                        case NAME_ERR_DISKLIKE:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "pool name is reserved"));
                                break;

                        case NAME_ERR_LEADING_SLASH:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "leading slash in name"));
                                break;

                        case NAME_ERR_EMPTY_COMPONENT:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "empty component in name"));
                                break;

                        case NAME_ERR_TRAILING_SLASH:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "trailing slash in name"));
                                break;

                        case NAME_ERR_MULTIPLE_DELIMITERS:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "multiple '@' and/or '#' delimiters in "
                                    "name"));
                                break;
                        case NAME_ERR_NO_AT:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "permission set is missing '@'"));

                        default:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "(%d) not defined"), why);
                                break;
                        }
                }
                return (B_FALSE);
        }

        return (B_TRUE);
}

/*
 * Open a handle to the given pool, even if the pool is currently in the FAULTED
 * state.
 */
zpool_handle_t *
zpool_open_canfail(libzfs_handle_t *hdl, const char *pool)
{
        zpool_handle_t *zhp;
        boolean_t missing;

        /*
         * Make sure the pool name is valid.
         */
        if (!zpool_name_valid(hdl, B_TRUE, pool)) {
                (void) zfs_error_fmt(hdl, EZFS_INVALIDNAME,
                    dgettext(TEXT_DOMAIN, "cannot open '%s'"),
                    pool);
                return (NULL);
        }

        if ((zhp = zfs_alloc(hdl, sizeof (zpool_handle_t))) == NULL)
                return (NULL);

        zhp->zpool_hdl = hdl;
        (void) strlcpy(zhp->zpool_name, pool, sizeof (zhp->zpool_name));

        if (zpool_refresh_stats(zhp, &missing) != 0) {
                zpool_close(zhp);
                return (NULL);
        }

        if (missing) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "no such pool"));
                (void) zfs_error_fmt(hdl, EZFS_NOENT,
                    dgettext(TEXT_DOMAIN, "cannot open '%s'"), pool);
                zpool_close(zhp);
                return (NULL);
        }

        return (zhp);
}

/*
 * Like the above, but silent on error.  Used when iterating over pools (because
 * the configuration cache may be out of date).
 */
int
zpool_open_silent(libzfs_handle_t *hdl, const char *pool, zpool_handle_t **ret)
{
        zpool_handle_t *zhp;
        boolean_t missing;

        if ((zhp = zfs_alloc(hdl, sizeof (zpool_handle_t))) == NULL)
                return (-1);

        zhp->zpool_hdl = hdl;
        (void) strlcpy(zhp->zpool_name, pool, sizeof (zhp->zpool_name));

        if (zpool_refresh_stats(zhp, &missing) != 0) {
                zpool_close(zhp);
                return (-1);
        }

        if (missing) {
                zpool_close(zhp);
                *ret = NULL;
                return (0);
        }

        *ret = zhp;
        return (0);
}

/*
 * Similar to zpool_open_canfail(), but refuses to open pools in the faulted
 * state.
 */
zpool_handle_t *
zpool_open(libzfs_handle_t *hdl, const char *pool)
{
        zpool_handle_t *zhp;

        if ((zhp = zpool_open_canfail(hdl, pool)) == NULL)
                return (NULL);

        if (zhp->zpool_state == POOL_STATE_UNAVAIL) {
                (void) zfs_error_fmt(hdl, EZFS_POOLUNAVAIL,
                    dgettext(TEXT_DOMAIN, "cannot open '%s'"), zhp->zpool_name);
                zpool_close(zhp);
                return (NULL);
        }

        return (zhp);
}

/*
 * Close the handle.  Simply frees the memory associated with the handle.
 */
void
zpool_close(zpool_handle_t *zhp)
{
        nvlist_free(zhp->zpool_config);
        nvlist_free(zhp->zpool_old_config);
        nvlist_free(zhp->zpool_props);
        free(zhp);
}

/*
 * Return the name of the pool.
 */
const char *
zpool_get_name(zpool_handle_t *zhp)
{
        return (zhp->zpool_name);
}


/*
 * Return the state of the pool (ACTIVE or UNAVAILABLE)
 */
int
zpool_get_state(zpool_handle_t *zhp)
{
        return (zhp->zpool_state);
}

/*
 * Create the named pool, using the provided vdev list.  It is assumed
 * that the consumer has already validated the contents of the nvlist, so we
 * don't have to worry about error semantics.
 */
int
zpool_create(libzfs_handle_t *hdl, const char *pool, nvlist_t *nvroot,
    nvlist_t *props, nvlist_t *fsprops)
{
        zfs_cmd_t zc = {"\0"};
        nvlist_t *zc_fsprops = NULL;
        nvlist_t *zc_props = NULL;
        char msg[1024];
        int ret = -1;

        (void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
            "cannot create '%s'"), pool);

        if (!zpool_name_valid(hdl, B_FALSE, pool))
                return (zfs_error(hdl, EZFS_INVALIDNAME, msg));

        if (zcmd_write_conf_nvlist(hdl, &zc, nvroot) != 0)
                return (-1);

        if (props) {
                prop_flags_t flags = { .create = B_TRUE, .import = B_FALSE };

                if ((zc_props = zpool_valid_proplist(hdl, pool, props,
                    SPA_VERSION_1, flags, msg)) == NULL) {
                        goto create_failed;
                }
        }

        if (fsprops) {
                uint64_t zoned;
                char *zonestr;

                zoned = ((nvlist_lookup_string(fsprops,
                    zfs_prop_to_name(ZFS_PROP_ZONED), &zonestr) == 0) &&
                    strcmp(zonestr, "on") == 0);

                if ((zc_fsprops = zfs_valid_proplist(hdl, ZFS_TYPE_FILESYSTEM,
                    fsprops, zoned, NULL, NULL, msg)) == NULL) {
                        goto create_failed;
                }
                if (!zc_props &&
                    (nvlist_alloc(&zc_props, NV_UNIQUE_NAME, 0) != 0)) {
                        goto create_failed;
                }
                if (nvlist_add_nvlist(zc_props,
                    ZPOOL_ROOTFS_PROPS, zc_fsprops) != 0) {
                        goto create_failed;
                }
        }

        if (zc_props && zcmd_write_src_nvlist(hdl, &zc, zc_props) != 0)
                goto create_failed;

        (void) strlcpy(zc.zc_name, pool, sizeof (zc.zc_name));

        if ((ret = zfs_ioctl(hdl, ZFS_IOC_POOL_CREATE, &zc)) != 0) {

                zcmd_free_nvlists(&zc);
                nvlist_free(zc_props);
                nvlist_free(zc_fsprops);

                switch (errno) {
                case EBUSY:
                        /*
                         * This can happen if the user has specified the same
                         * device multiple times.  We can't reliably detect this
                         * until we try to add it and see we already have a
                         * label.  This can also happen under if the device is
                         * part of an active md or lvm device.
                         */
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "one or more vdevs refer to the same device, or "
                            "one of\nthe devices is part of an active md or "
                            "lvm device"));
                        return (zfs_error(hdl, EZFS_BADDEV, msg));

                case ERANGE:
                        /*
                         * This happens if the record size is smaller or larger
                         * than the allowed size range, or not a power of 2.
                         *
                         * NOTE: although zfs_valid_proplist is called earlier,
                         * this case may have slipped through since the
                         * pool does not exist yet and it is therefore
                         * impossible to read properties e.g. max blocksize
                         * from the pool.
                         */
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "record size invalid"));
                        return (zfs_error(hdl, EZFS_BADPROP, msg));

                case EOVERFLOW:
                        /*
                         * This occurs when one of the devices is below
                         * SPA_MINDEVSIZE.  Unfortunately, we can't detect which
                         * device was the problem device since there's no
                         * reliable way to determine device size from userland.
                         */
                        {
                                char buf[64];

                                zfs_nicenum(SPA_MINDEVSIZE, buf, sizeof (buf));

                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "one or more devices is less than the "
                                    "minimum size (%s)"), buf);
                        }
                        return (zfs_error(hdl, EZFS_BADDEV, msg));

                case ENOSPC:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "one or more devices is out of space"));
                        return (zfs_error(hdl, EZFS_BADDEV, msg));

                case ENOTBLK:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "cache device must be a disk or disk slice"));
                        return (zfs_error(hdl, EZFS_BADDEV, msg));

                default:
                        return (zpool_standard_error(hdl, errno, msg));
                }
        }

create_failed:
        zcmd_free_nvlists(&zc);
        nvlist_free(zc_props);
        nvlist_free(zc_fsprops);
        return (ret);
}

/*
 * Destroy the given pool.  It is up to the caller to ensure that there are no
 * datasets left in the pool.
 */
int
zpool_destroy(zpool_handle_t *zhp, const char *log_str)
{
        zfs_cmd_t zc = {"\0"};
        zfs_handle_t *zfp = NULL;
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        char msg[1024];

        if (zhp->zpool_state == POOL_STATE_ACTIVE &&
            (zfp = zfs_open(hdl, zhp->zpool_name, ZFS_TYPE_FILESYSTEM)) == NULL)
                return (-1);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        zc.zc_history = (uint64_t)(uintptr_t)log_str;

        if (zfs_ioctl(hdl, ZFS_IOC_POOL_DESTROY, &zc) != 0) {
                (void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
                    "cannot destroy '%s'"), zhp->zpool_name);

                if (errno == EROFS) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "one or more devices is read only"));
                        (void) zfs_error(hdl, EZFS_BADDEV, msg);
                } else {
                        (void) zpool_standard_error(hdl, errno, msg);
                }

                if (zfp)
                        zfs_close(zfp);
                return (-1);
        }

        if (zfp) {
                remove_mountpoint(zfp);
                zfs_close(zfp);
        }

        return (0);
}

/*
 * Add the given vdevs to the pool.  The caller must have already performed the
 * necessary verification to ensure that the vdev specification is well-formed.
 */
int
zpool_add(zpool_handle_t *zhp, nvlist_t *nvroot)
{
        zfs_cmd_t zc = {"\0"};
        int ret;
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        char msg[1024];
        nvlist_t **spares, **l2cache;
        uint_t nspares, nl2cache;

        (void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
            "cannot add to '%s'"), zhp->zpool_name);

        if (zpool_get_prop_int(zhp, ZPOOL_PROP_VERSION, NULL) <
            SPA_VERSION_SPARES &&
            nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
            &spares, &nspares) == 0) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "pool must be "
                    "upgraded to add hot spares"));
                return (zfs_error(hdl, EZFS_BADVERSION, msg));
        }

        if (zpool_get_prop_int(zhp, ZPOOL_PROP_VERSION, NULL) <
            SPA_VERSION_L2CACHE &&
            nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
            &l2cache, &nl2cache) == 0) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "pool must be "
                    "upgraded to add cache devices"));
                return (zfs_error(hdl, EZFS_BADVERSION, msg));
        }

        if (zcmd_write_conf_nvlist(hdl, &zc, nvroot) != 0)
                return (-1);
        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));

        if (zfs_ioctl(hdl, ZFS_IOC_VDEV_ADD, &zc) != 0) {
                switch (errno) {
                case EBUSY:
                        /*
                         * This can happen if the user has specified the same
                         * device multiple times.  We can't reliably detect this
                         * until we try to add it and see we already have a
                         * label.
                         */
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "one or more vdevs refer to the same device"));
                        (void) zfs_error(hdl, EZFS_BADDEV, msg);
                        break;

                case EOVERFLOW:
                        /*
                         * This occurrs when one of the devices is below
                         * SPA_MINDEVSIZE.  Unfortunately, we can't detect which
                         * device was the problem device since there's no
                         * reliable way to determine device size from userland.
                         */
                        {
                                char buf[64];

                                zfs_nicenum(SPA_MINDEVSIZE, buf, sizeof (buf));

                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "device is less than the minimum "
                                    "size (%s)"), buf);
                        }
                        (void) zfs_error(hdl, EZFS_BADDEV, msg);
                        break;

                case ENOTSUP:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "pool must be upgraded to add these vdevs"));
                        (void) zfs_error(hdl, EZFS_BADVERSION, msg);
                        break;

                case ENOTBLK:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "cache device must be a disk or disk slice"));
                        (void) zfs_error(hdl, EZFS_BADDEV, msg);
                        break;

                default:
                        (void) zpool_standard_error(hdl, errno, msg);
                }

                ret = -1;
        } else {
                ret = 0;
        }

        zcmd_free_nvlists(&zc);

        return (ret);
}

/*
 * Exports the pool from the system.  The caller must ensure that there are no
 * mounted datasets in the pool.
 */
static int
zpool_export_common(zpool_handle_t *zhp, boolean_t force, boolean_t hardforce,
    const char *log_str)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];

        (void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
            "cannot export '%s'"), zhp->zpool_name);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        zc.zc_cookie = force;
        zc.zc_guid = hardforce;
        zc.zc_history = (uint64_t)(uintptr_t)log_str;

        if (zfs_ioctl(zhp->zpool_hdl, ZFS_IOC_POOL_EXPORT, &zc) != 0) {
                switch (errno) {
                case EXDEV:
                        zfs_error_aux(zhp->zpool_hdl, dgettext(TEXT_DOMAIN,
                            "use '-f' to override the following errors:\n"
                            "'%s' has an active shared spare which could be"
                            " used by other pools once '%s' is exported."),
                            zhp->zpool_name, zhp->zpool_name);
                        return (zfs_error(zhp->zpool_hdl, EZFS_ACTIVE_SPARE,
                            msg));
                default:
                        return (zpool_standard_error_fmt(zhp->zpool_hdl, errno,
                            msg));
                }
        }

        return (0);
}

int
zpool_export(zpool_handle_t *zhp, boolean_t force, const char *log_str)
{
        return (zpool_export_common(zhp, force, B_FALSE, log_str));
}

int
zpool_export_force(zpool_handle_t *zhp, const char *log_str)
{
        return (zpool_export_common(zhp, B_TRUE, B_TRUE, log_str));
}

static void
zpool_rewind_exclaim(libzfs_handle_t *hdl, const char *name, boolean_t dryrun,
    nvlist_t *config)
{
        nvlist_t *nv = NULL;
        uint64_t rewindto;
        int64_t loss = -1;
        struct tm t;
        char timestr[128];

        if (!hdl->libzfs_printerr || config == NULL)
                return;

        if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_LOAD_INFO, &nv) != 0 ||
            nvlist_lookup_nvlist(nv, ZPOOL_CONFIG_REWIND_INFO, &nv) != 0) {
                return;
        }

        if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_LOAD_TIME, &rewindto) != 0)
                return;
        (void) nvlist_lookup_int64(nv, ZPOOL_CONFIG_REWIND_TIME, &loss);

        if (localtime_r((time_t *)&rewindto, &t) != NULL &&
            strftime(timestr, 128, "%c", &t) != 0) {
                if (dryrun) {
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "Would be able to return %s "
                            "to its state as of %s.\n"),
                            name, timestr);
                } else {
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "Pool %s returned to its state as of %s.\n"),
                            name, timestr);
                }
                if (loss > 120) {
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "%s approximately %lld "),
                            dryrun ? "Would discard" : "Discarded",
                            ((longlong_t)loss + 30) / 60);
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "minutes of transactions.\n"));
                } else if (loss > 0) {
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "%s approximately %lld "),
                            dryrun ? "Would discard" : "Discarded",
                            (longlong_t)loss);
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "seconds of transactions.\n"));
                }
        }
}

void
zpool_explain_recover(libzfs_handle_t *hdl, const char *name, int reason,
    nvlist_t *config)
{
        nvlist_t *nv = NULL;
        int64_t loss = -1;
        uint64_t edata = UINT64_MAX;
        uint64_t rewindto;
        struct tm t;
        char timestr[128];

        if (!hdl->libzfs_printerr)
                return;

        if (reason >= 0)
                (void) printf(dgettext(TEXT_DOMAIN, "action: "));
        else
                (void) printf(dgettext(TEXT_DOMAIN, "\t"));

        /* All attempted rewinds failed if ZPOOL_CONFIG_LOAD_TIME missing */
        if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_LOAD_INFO, &nv) != 0 ||
            nvlist_lookup_nvlist(nv, ZPOOL_CONFIG_REWIND_INFO, &nv) != 0 ||
            nvlist_lookup_uint64(nv, ZPOOL_CONFIG_LOAD_TIME, &rewindto) != 0)
                goto no_info;

        (void) nvlist_lookup_int64(nv, ZPOOL_CONFIG_REWIND_TIME, &loss);
        (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_LOAD_DATA_ERRORS,
            &edata);

        (void) printf(dgettext(TEXT_DOMAIN,
            "Recovery is possible, but will result in some data loss.\n"));

        if (localtime_r((time_t *)&rewindto, &t) != NULL &&
            strftime(timestr, 128, "%c", &t) != 0) {
                (void) printf(dgettext(TEXT_DOMAIN,
                    "\tReturning the pool to its state as of %s\n"
                    "\tshould correct the problem.  "),
                    timestr);
        } else {
                (void) printf(dgettext(TEXT_DOMAIN,
                    "\tReverting the pool to an earlier state "
                    "should correct the problem.\n\t"));
        }

        if (loss > 120) {
                (void) printf(dgettext(TEXT_DOMAIN,
                    "Approximately %lld minutes of data\n"
                    "\tmust be discarded, irreversibly.  "),
                    ((longlong_t)loss + 30) / 60);
        } else if (loss > 0) {
                (void) printf(dgettext(TEXT_DOMAIN,
                    "Approximately %lld seconds of data\n"
                    "\tmust be discarded, irreversibly.  "),
                    (longlong_t)loss);
        }
        if (edata != 0 && edata != UINT64_MAX) {
                if (edata == 1) {
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "After rewind, at least\n"
                            "\tone persistent user-data error will remain.  "));
                } else {
                        (void) printf(dgettext(TEXT_DOMAIN,
                            "After rewind, several\n"
                            "\tpersistent user-data errors will remain.  "));
                }
        }
        (void) printf(dgettext(TEXT_DOMAIN,
            "Recovery can be attempted\n\tby executing 'zpool %s -F %s'.  "),
            reason >= 0 ? "clear" : "import", name);

        (void) printf(dgettext(TEXT_DOMAIN,
            "A scrub of the pool\n"
            "\tis strongly recommended after recovery.\n"));
        return;

no_info:
        (void) printf(dgettext(TEXT_DOMAIN,
            "Destroy and re-create the pool from\n\ta backup source.\n"));
}

/*
 * zpool_import() is a contracted interface. Should be kept the same
 * if possible.
 *
 * Applications should use zpool_import_props() to import a pool with
 * new properties value to be set.
 */
int
zpool_import(libzfs_handle_t *hdl, nvlist_t *config, const char *newname,
    char *altroot)
{
        nvlist_t *props = NULL;
        int ret;

        if (altroot != NULL) {
                if (nvlist_alloc(&props, NV_UNIQUE_NAME, 0) != 0) {
                        return (zfs_error_fmt(hdl, EZFS_NOMEM,
                            dgettext(TEXT_DOMAIN, "cannot import '%s'"),
                            newname));
                }

                if (nvlist_add_string(props,
                    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), altroot) != 0 ||
                    nvlist_add_string(props,
                    zpool_prop_to_name(ZPOOL_PROP_CACHEFILE), "none") != 0) {
                        nvlist_free(props);
                        return (zfs_error_fmt(hdl, EZFS_NOMEM,
                            dgettext(TEXT_DOMAIN, "cannot import '%s'"),
                            newname));
                }
        }

        ret = zpool_import_props(hdl, config, newname, props,
            ZFS_IMPORT_NORMAL);
        nvlist_free(props);
        return (ret);
}

static void
print_vdev_tree(libzfs_handle_t *hdl, const char *name, nvlist_t *nv,
    int indent)
{
        nvlist_t **child;
        uint_t c, children;
        char *vname;
        uint64_t is_log = 0;

        (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_IS_LOG,
            &is_log);

        if (name != NULL)
                (void) printf("\t%*s%s%s\n", indent, "", name,
                    is_log ? " [log]" : "");

        if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
            &child, &children) != 0)
                return;

        for (c = 0; c < children; c++) {
                vname = zpool_vdev_name(hdl, NULL, child[c], VDEV_NAME_TYPE_ID);
                print_vdev_tree(hdl, vname, child[c], indent + 2);
                free(vname);
        }
}

void
zpool_print_unsup_feat(nvlist_t *config)
{
        nvlist_t *nvinfo, *unsup_feat;
        nvpair_t *nvp;

        verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_LOAD_INFO, &nvinfo) ==
            0);
        verify(nvlist_lookup_nvlist(nvinfo, ZPOOL_CONFIG_UNSUP_FEAT,
            &unsup_feat) == 0);

        for (nvp = nvlist_next_nvpair(unsup_feat, NULL); nvp != NULL;
            nvp = nvlist_next_nvpair(unsup_feat, nvp)) {
                char *desc;

                verify(nvpair_type(nvp) == DATA_TYPE_STRING);
                verify(nvpair_value_string(nvp, &desc) == 0);

                if (strlen(desc) > 0)
                        (void) printf("\t%s (%s)\n", nvpair_name(nvp), desc);
                else
                        (void) printf("\t%s\n", nvpair_name(nvp));
        }
}

/*
 * Import the given pool using the known configuration and a list of
 * properties to be set. The configuration should have come from
 * zpool_find_import(). The 'newname' parameters control whether the pool
 * is imported with a different name.
 */
int
zpool_import_props(libzfs_handle_t *hdl, nvlist_t *config, const char *newname,
    nvlist_t *props, int flags)
{
        zfs_cmd_t zc = {"\0"};
        zpool_rewind_policy_t policy;
        nvlist_t *nv = NULL;
        nvlist_t *nvinfo = NULL;
        nvlist_t *missing = NULL;
        char *thename;
        char *origname;
        int ret;
        int error = 0;
        char errbuf[1024];

        verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
            &origname) == 0);

        (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
            "cannot import pool '%s'"), origname);

        if (newname != NULL) {
                if (!zpool_name_valid(hdl, B_FALSE, newname))
                        return (zfs_error_fmt(hdl, EZFS_INVALIDNAME,
                            dgettext(TEXT_DOMAIN, "cannot import '%s'"),
                            newname));
                thename = (char *)newname;
        } else {
                thename = origname;
        }

        if (props != NULL) {
                uint64_t version;
                prop_flags_t flags = { .create = B_FALSE, .import = B_TRUE };

                verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
                    &version) == 0);

                if ((props = zpool_valid_proplist(hdl, origname,
                    props, version, flags, errbuf)) == NULL)
                        return (-1);
                if (zcmd_write_src_nvlist(hdl, &zc, props) != 0) {
                        nvlist_free(props);
                        return (-1);
                }
                nvlist_free(props);
        }

        (void) strlcpy(zc.zc_name, thename, sizeof (zc.zc_name));

        verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
            &zc.zc_guid) == 0);

        if (zcmd_write_conf_nvlist(hdl, &zc, config) != 0) {
                zcmd_free_nvlists(&zc);
                return (-1);
        }
        if (zcmd_alloc_dst_nvlist(hdl, &zc, zc.zc_nvlist_conf_size * 2) != 0) {
                zcmd_free_nvlists(&zc);
                return (-1);
        }

        zc.zc_cookie = flags;
        while ((ret = zfs_ioctl(hdl, ZFS_IOC_POOL_IMPORT, &zc)) != 0 &&
            errno == ENOMEM) {
                if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
                        zcmd_free_nvlists(&zc);
                        return (-1);
                }
        }
        if (ret != 0)
                error = errno;

        (void) zcmd_read_dst_nvlist(hdl, &zc, &nv);

        zcmd_free_nvlists(&zc);

        zpool_get_rewind_policy(config, &policy);

        if (error) {
                char desc[1024];

                /*
                 * Dry-run failed, but we print out what success
                 * looks like if we found a best txg
                 */
                if (policy.zrp_request & ZPOOL_TRY_REWIND) {
                        zpool_rewind_exclaim(hdl, newname ? origname : thename,
                            B_TRUE, nv);
                        nvlist_free(nv);
                        return (-1);
                }

                if (newname == NULL)
                        (void) snprintf(desc, sizeof (desc),
                            dgettext(TEXT_DOMAIN, "cannot import '%s'"),
                            thename);
                else
                        (void) snprintf(desc, sizeof (desc),
                            dgettext(TEXT_DOMAIN, "cannot import '%s' as '%s'"),
                            origname, thename);

                switch (error) {
                case ENOTSUP:
                        if (nv != NULL && nvlist_lookup_nvlist(nv,
                            ZPOOL_CONFIG_LOAD_INFO, &nvinfo) == 0 &&
                            nvlist_exists(nvinfo, ZPOOL_CONFIG_UNSUP_FEAT)) {
                                (void) printf(dgettext(TEXT_DOMAIN, "This "
                                    "pool uses the following feature(s) not "
                                    "supported by this system:\n"));
                                zpool_print_unsup_feat(nv);
                                if (nvlist_exists(nvinfo,
                                    ZPOOL_CONFIG_CAN_RDONLY)) {
                                        (void) printf(dgettext(TEXT_DOMAIN,
                                            "All unsupported features are only "
                                            "required for writing to the pool."
                                            "\nThe pool can be imported using "
                                            "'-o readonly=on'.\n"));
                                }
                        }
                        /*
                         * Unsupported version.
                         */
                        (void) zfs_error(hdl, EZFS_BADVERSION, desc);
                        break;

                case EINVAL:
                        (void) zfs_error(hdl, EZFS_INVALCONFIG, desc);
                        break;

                case EROFS:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "one or more devices is read only"));
                        (void) zfs_error(hdl, EZFS_BADDEV, desc);
                        break;

                case ENXIO:
                        if (nv && nvlist_lookup_nvlist(nv,
                            ZPOOL_CONFIG_LOAD_INFO, &nvinfo) == 0 &&
                            nvlist_lookup_nvlist(nvinfo,
                            ZPOOL_CONFIG_MISSING_DEVICES, &missing) == 0) {
                                (void) printf(dgettext(TEXT_DOMAIN,
                                    "The devices below are missing, use "
                                    "'-m' to import the pool anyway:\n"));
                                print_vdev_tree(hdl, NULL, missing, 2);
                                (void) printf("\n");
                        }
                        (void) zpool_standard_error(hdl, error, desc);
                        break;

                case EEXIST:
                        (void) zpool_standard_error(hdl, error, desc);
                        break;

                case EBUSY:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "one or more devices are already in use\n"));
                        (void) zfs_error(hdl, EZFS_BADDEV, desc);
                        break;
                case ENAMETOOLONG:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "new name of at least one dataset is longer than "
                            "the maximum allowable length"));
                        (void) zfs_error(hdl, EZFS_NAMETOOLONG, desc);
                        break;
                default:
                        (void) zpool_standard_error(hdl, error, desc);
                        zpool_explain_recover(hdl,
                            newname ? origname : thename, -error, nv);
                        break;
                }

                nvlist_free(nv);
                ret = -1;
        } else {
                zpool_handle_t *zhp;

                /*
                 * This should never fail, but play it safe anyway.
                 */
                if (zpool_open_silent(hdl, thename, &zhp) != 0)
                        ret = -1;
                else if (zhp != NULL)
                        zpool_close(zhp);
                if (policy.zrp_request &
                    (ZPOOL_DO_REWIND | ZPOOL_TRY_REWIND)) {
                        zpool_rewind_exclaim(hdl, newname ? origname : thename,
                            ((policy.zrp_request & ZPOOL_TRY_REWIND) != 0), nv);
                }
                nvlist_free(nv);
                return (0);
        }

        return (ret);
}

/*
 * Scan the pool.
 */
int
zpool_scan(zpool_handle_t *zhp, pool_scan_func_t func)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        zc.zc_cookie = func;

        if (zfs_ioctl(hdl, ZFS_IOC_POOL_SCAN, &zc) == 0 ||
            (errno == ENOENT && func != POOL_SCAN_NONE))
                return (0);

        if (func == POOL_SCAN_SCRUB) {
                (void) snprintf(msg, sizeof (msg),
                    dgettext(TEXT_DOMAIN, "cannot scrub %s"), zc.zc_name);
        } else if (func == POOL_SCAN_NONE) {
                (void) snprintf(msg, sizeof (msg),
                    dgettext(TEXT_DOMAIN, "cannot cancel scrubbing %s"),
                    zc.zc_name);
        } else {
                assert(!"unexpected result");
        }

        if (errno == EBUSY) {
                nvlist_t *nvroot;
                pool_scan_stat_t *ps = NULL;
                uint_t psc;

                verify(nvlist_lookup_nvlist(zhp->zpool_config,
                    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
                (void) nvlist_lookup_uint64_array(nvroot,
                    ZPOOL_CONFIG_SCAN_STATS, (uint64_t **)&ps, &psc);
                if (ps && ps->pss_func == POOL_SCAN_SCRUB)
                        return (zfs_error(hdl, EZFS_SCRUBBING, msg));
                else
                        return (zfs_error(hdl, EZFS_RESILVERING, msg));
        } else if (errno == ENOENT) {
                return (zfs_error(hdl, EZFS_NO_SCRUB, msg));
        } else {
                return (zpool_standard_error(hdl, errno, msg));
        }
}

/*
 * Find a vdev that matches the search criteria specified. We use the
 * the nvpair name to determine how we should look for the device.
 * 'avail_spare' is set to TRUE if the provided guid refers to an AVAIL
 * spare; but FALSE if its an INUSE spare.
 */
static nvlist_t *
vdev_to_nvlist_iter(nvlist_t *nv, nvlist_t *search, boolean_t *avail_spare,
    boolean_t *l2cache, boolean_t *log)
{
        uint_t c, children;
        nvlist_t **child;
        nvlist_t *ret;
        uint64_t is_log;
        char *srchkey;
        nvpair_t *pair = nvlist_next_nvpair(search, NULL);

        /* Nothing to look for */
        if (search == NULL || pair == NULL)
                return (NULL);

        /* Obtain the key we will use to search */
        srchkey = nvpair_name(pair);

        switch (nvpair_type(pair)) {
        case DATA_TYPE_UINT64:
                if (strcmp(srchkey, ZPOOL_CONFIG_GUID) == 0) {
                        uint64_t srchval, theguid;

                        verify(nvpair_value_uint64(pair, &srchval) == 0);
                        verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID,
                            &theguid) == 0);
                        if (theguid == srchval)
                                return (nv);
                }
                break;

        case DATA_TYPE_STRING: {
                char *srchval, *val;

                verify(nvpair_value_string(pair, &srchval) == 0);
                if (nvlist_lookup_string(nv, srchkey, &val) != 0)
                        break;

                /*
                 * Search for the requested value. Special cases:
                 *
                 * - ZPOOL_CONFIG_PATH for whole disk entries.  These end in
                 *   "-part1", or "p1".  The suffix is hidden from the user,
                 *   but included in the string, so this matches around it.
                 * - ZPOOL_CONFIG_PATH for short names zfs_strcmp_shortname()
                 *   is used to check all possible expanded paths.
                 * - looking for a top-level vdev name (i.e. ZPOOL_CONFIG_TYPE).
                 *
                 * Otherwise, all other searches are simple string compares.
                 */
                if (strcmp(srchkey, ZPOOL_CONFIG_PATH) == 0) {
                        uint64_t wholedisk = 0;

                        (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK,
                            &wholedisk);
                        if (zfs_strcmp_pathname(srchval, val, wholedisk) == 0)
                                return (nv);

                } else if (strcmp(srchkey, ZPOOL_CONFIG_TYPE) == 0 && val) {
                        char *type, *idx, *end, *p;
                        uint64_t id, vdev_id;

                        /*
                         * Determine our vdev type, keeping in mind
                         * that the srchval is composed of a type and
                         * vdev id pair (i.e. mirror-4).
                         */
                        if ((type = strdup(srchval)) == NULL)
                                return (NULL);

                        if ((p = strrchr(type, '-')) == NULL) {
                                free(type);
                                break;
                        }
                        idx = p + 1;
                        *p = '\0';

                        /*
                         * If the types don't match then keep looking.
                         */
                        if (strncmp(val, type, strlen(val)) != 0) {
                                free(type);
                                break;
                        }

                        verify(strncmp(type, VDEV_TYPE_RAIDZ,
                            strlen(VDEV_TYPE_RAIDZ)) == 0 ||
                            strncmp(type, VDEV_TYPE_MIRROR,
                            strlen(VDEV_TYPE_MIRROR)) == 0);
                        verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ID,
                            &id) == 0);

                        errno = 0;
                        vdev_id = strtoull(idx, &end, 10);

                        free(type);
                        if (errno != 0)
                                return (NULL);

                        /*
                         * Now verify that we have the correct vdev id.
                         */
                        if (vdev_id == id)
                                return (nv);
                }

                /*
                 * Common case
                 */
                if (strcmp(srchval, val) == 0)
                        return (nv);
                break;
        }

        default:
                break;
        }

        if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
            &child, &children) != 0)
                return (NULL);

        for (c = 0; c < children; c++) {
                if ((ret = vdev_to_nvlist_iter(child[c], search,
                    avail_spare, l2cache, NULL)) != NULL) {
                        /*
                         * The 'is_log' value is only set for the toplevel
                         * vdev, not the leaf vdevs.  So we always lookup the
                         * log device from the root of the vdev tree (where
                         * 'log' is non-NULL).
                         */
                        if (log != NULL &&
                            nvlist_lookup_uint64(child[c],
                            ZPOOL_CONFIG_IS_LOG, &is_log) == 0 &&
                            is_log) {
                                *log = B_TRUE;
                        }
                        return (ret);
                }
        }

        if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_SPARES,
            &child, &children) == 0) {
                for (c = 0; c < children; c++) {
                        if ((ret = vdev_to_nvlist_iter(child[c], search,
                            avail_spare, l2cache, NULL)) != NULL) {
                                *avail_spare = B_TRUE;
                                return (ret);
                        }
                }
        }

        if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_L2CACHE,
            &child, &children) == 0) {
                for (c = 0; c < children; c++) {
                        if ((ret = vdev_to_nvlist_iter(child[c], search,
                            avail_spare, l2cache, NULL)) != NULL) {
                                *l2cache = B_TRUE;
                                return (ret);
                        }
                }
        }

        return (NULL);
}

/*
 * Given a physical path (minus the "/devices" prefix), find the
 * associated vdev.
 */
nvlist_t *
zpool_find_vdev_by_physpath(zpool_handle_t *zhp, const char *ppath,
    boolean_t *avail_spare, boolean_t *l2cache, boolean_t *log)
{
        nvlist_t *search, *nvroot, *ret;

        verify(nvlist_alloc(&search, NV_UNIQUE_NAME, KM_SLEEP) == 0);
        verify(nvlist_add_string(search, ZPOOL_CONFIG_PHYS_PATH, ppath) == 0);

        verify(nvlist_lookup_nvlist(zhp->zpool_config, ZPOOL_CONFIG_VDEV_TREE,
            &nvroot) == 0);

        *avail_spare = B_FALSE;
        *l2cache = B_FALSE;
        if (log != NULL)
                *log = B_FALSE;
        ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log);
        nvlist_free(search);

        return (ret);
}

/*
 * Determine if we have an "interior" top-level vdev (i.e mirror/raidz).
 */
boolean_t
zpool_vdev_is_interior(const char *name)
{
        if (strncmp(name, VDEV_TYPE_RAIDZ, strlen(VDEV_TYPE_RAIDZ)) == 0 ||
            strncmp(name, VDEV_TYPE_MIRROR, strlen(VDEV_TYPE_MIRROR)) == 0)
                return (B_TRUE);
        return (B_FALSE);
}

nvlist_t *
zpool_find_vdev(zpool_handle_t *zhp, const char *path, boolean_t *avail_spare,
    boolean_t *l2cache, boolean_t *log)
{
        char *end;
        nvlist_t *nvroot, *search, *ret;
        uint64_t guid;

        verify(nvlist_alloc(&search, NV_UNIQUE_NAME, KM_SLEEP) == 0);

        guid = strtoull(path, &end, 0);
        if (guid != 0 && *end == '\0') {
                verify(nvlist_add_uint64(search, ZPOOL_CONFIG_GUID, guid) == 0);
        } else if (zpool_vdev_is_interior(path)) {
                verify(nvlist_add_string(search, ZPOOL_CONFIG_TYPE, path) == 0);
        } else {
                verify(nvlist_add_string(search, ZPOOL_CONFIG_PATH, path) == 0);
        }

        verify(nvlist_lookup_nvlist(zhp->zpool_config, ZPOOL_CONFIG_VDEV_TREE,
            &nvroot) == 0);

        *avail_spare = B_FALSE;
        *l2cache = B_FALSE;
        if (log != NULL)
                *log = B_FALSE;
        ret = vdev_to_nvlist_iter(nvroot, search, avail_spare, l2cache, log);
        nvlist_free(search);

        return (ret);
}

static int
vdev_online(nvlist_t *nv)
{
        uint64_t ival;

        if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_OFFLINE, &ival) == 0 ||
            nvlist_lookup_uint64(nv, ZPOOL_CONFIG_FAULTED, &ival) == 0 ||
            nvlist_lookup_uint64(nv, ZPOOL_CONFIG_REMOVED, &ival) == 0)
                return (0);

        return (1);
}

/*
 * Helper function for zpool_get_physpaths().
 */
static int
vdev_get_one_physpath(nvlist_t *config, char *physpath, size_t physpath_size,
    size_t *bytes_written)
{
        size_t bytes_left, pos, rsz;
        char *tmppath;
        const char *format;

        if (nvlist_lookup_string(config, ZPOOL_CONFIG_PHYS_PATH,
            &tmppath) != 0)
                return (EZFS_NODEVICE);

        pos = *bytes_written;
        bytes_left = physpath_size - pos;
        format = (pos == 0) ? "%s" : " %s";

        rsz = snprintf(physpath + pos, bytes_left, format, tmppath);
        *bytes_written += rsz;

        if (rsz >= bytes_left) {
                /* if physpath was not copied properly, clear it */
                if (bytes_left != 0) {
                        physpath[pos] = 0;
                }
                return (EZFS_NOSPC);
        }
        return (0);
}

static int
vdev_get_physpaths(nvlist_t *nv, char *physpath, size_t phypath_size,
    size_t *rsz, boolean_t is_spare)
{
        char *type;
        int ret;

        if (nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) != 0)
                return (EZFS_INVALCONFIG);

        if (strcmp(type, VDEV_TYPE_DISK) == 0) {
                /*
                 * An active spare device has ZPOOL_CONFIG_IS_SPARE set.
                 * For a spare vdev, we only want to boot from the active
                 * spare device.
                 */
                if (is_spare) {
                        uint64_t spare = 0;
                        (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_IS_SPARE,
                            &spare);
                        if (!spare)
                                return (EZFS_INVALCONFIG);
                }

                if (vdev_online(nv)) {
                        if ((ret = vdev_get_one_physpath(nv, physpath,
                            phypath_size, rsz)) != 0)
                                return (ret);
                }
        } else if (strcmp(type, VDEV_TYPE_MIRROR) == 0 ||
            strcmp(type, VDEV_TYPE_RAIDZ) == 0 ||
            strcmp(type, VDEV_TYPE_REPLACING) == 0 ||
            (is_spare = (strcmp(type, VDEV_TYPE_SPARE) == 0))) {
                nvlist_t **child;
                uint_t count;
                int i, ret;

                if (nvlist_lookup_nvlist_array(nv,
                    ZPOOL_CONFIG_CHILDREN, &child, &count) != 0)
                        return (EZFS_INVALCONFIG);

                for (i = 0; i < count; i++) {
                        ret = vdev_get_physpaths(child[i], physpath,
                            phypath_size, rsz, is_spare);
                        if (ret == EZFS_NOSPC)
                                return (ret);
                }
        }

        return (EZFS_POOL_INVALARG);
}

/*
 * Get phys_path for a root pool config.
 * Return 0 on success; non-zero on failure.
 */
static int
zpool_get_config_physpath(nvlist_t *config, char *physpath, size_t phypath_size)
{
        size_t rsz;
        nvlist_t *vdev_root;
        nvlist_t **child;
        uint_t count;
        char *type;

        rsz = 0;

        if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
            &vdev_root) != 0)
                return (EZFS_INVALCONFIG);

        if (nvlist_lookup_string(vdev_root, ZPOOL_CONFIG_TYPE, &type) != 0 ||
            nvlist_lookup_nvlist_array(vdev_root, ZPOOL_CONFIG_CHILDREN,
            &child, &count) != 0)
                return (EZFS_INVALCONFIG);

        /*
         * root pool can only have a single top-level vdev.
         */
        if (strcmp(type, VDEV_TYPE_ROOT) != 0 || count != 1)
                return (EZFS_POOL_INVALARG);

        (void) vdev_get_physpaths(child[0], physpath, phypath_size, &rsz,
            B_FALSE);

        /* No online devices */
        if (rsz == 0)
                return (EZFS_NODEVICE);

        return (0);
}

/*
 * Get phys_path for a root pool
 * Return 0 on success; non-zero on failure.
 */
int
zpool_get_physpath(zpool_handle_t *zhp, char *physpath, size_t phypath_size)
{
        return (zpool_get_config_physpath(zhp->zpool_config, physpath,
            phypath_size));
}

/*
 * If the device has being dynamically expanded then we need to relabel
 * the disk to use the new unallocated space.
 */
static int
zpool_relabel_disk(libzfs_handle_t *hdl, const char *path, const char *msg)
{
        int fd, error;

        if ((fd = open(path, O_RDWR|O_DIRECT)) < 0) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "cannot "
                    "relabel '%s': unable to open device: %d"), path, errno);
                return (zfs_error(hdl, EZFS_OPENFAILED, msg));
        }

        /*
         * It's possible that we might encounter an error if the device
         * does not have any unallocated space left. If so, we simply
         * ignore that error and continue on.
         *
         * Also, we don't call efi_rescan() - that would just return EBUSY.
         * The module will do it for us in vdev_disk_open().
         */
        error = efi_use_whole_disk(fd);
        (void) close(fd);
        if (error && error != VT_ENOSPC) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "cannot "
                    "relabel '%s': unable to read disk capacity"), path);
                return (zfs_error(hdl, EZFS_NOCAP, msg));
        }
        return (0);
}

/*
 * Bring the specified vdev online.   The 'flags' parameter is a set of the
 * ZFS_ONLINE_* flags.
 */
int
zpool_vdev_online(zpool_handle_t *zhp, const char *path, int flags,
    vdev_state_t *newstate)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        nvlist_t *tgt;
        boolean_t avail_spare, l2cache, islog;
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        int error;

        if (flags & ZFS_ONLINE_EXPAND) {
                (void) snprintf(msg, sizeof (msg),
                    dgettext(TEXT_DOMAIN, "cannot expand %s"), path);
        } else {
                (void) snprintf(msg, sizeof (msg),
                    dgettext(TEXT_DOMAIN, "cannot online %s"), path);
        }

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if ((tgt = zpool_find_vdev(zhp, path, &avail_spare, &l2cache,
            &islog)) == NULL)
                return (zfs_error(hdl, EZFS_NODEVICE, msg));

        verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID, &zc.zc_guid) == 0);

        if (avail_spare)
                return (zfs_error(hdl, EZFS_ISSPARE, msg));

        if (flags & ZFS_ONLINE_EXPAND ||
            zpool_get_prop_int(zhp, ZPOOL_PROP_AUTOEXPAND, NULL)) {
                uint64_t wholedisk = 0;

                (void) nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_WHOLE_DISK,
                    &wholedisk);

                /*
                 * XXX - L2ARC 1.0 devices can't support expansion.
                 */
                if (l2cache) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "cannot expand cache devices"));
                        return (zfs_error(hdl, EZFS_VDEVNOTSUP, msg));
                }

                if (wholedisk) {
                        const char *fullpath = path;
                        char buf[MAXPATHLEN];

                        if (path[0] != '/') {
                                error = zfs_resolve_shortname(path, buf,
                                    sizeof (buf));
                                if (error != 0)
                                        return (zfs_error(hdl, EZFS_NODEVICE,
                                            msg));

                                fullpath = buf;
                        }

                        error = zpool_relabel_disk(hdl, fullpath, msg);
                        if (error != 0)
                                return (error);
                }
        }

        zc.zc_cookie = VDEV_STATE_ONLINE;
        zc.zc_obj = flags;

        if (zfs_ioctl(hdl, ZFS_IOC_VDEV_SET_STATE, &zc) != 0) {
                if (errno == EINVAL) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "was split "
                            "from this pool into a new one.  Use '%s' "
                            "instead"), "zpool detach");
                        return (zfs_error(hdl, EZFS_POSTSPLIT_ONLINE, msg));
                }
                return (zpool_standard_error(hdl, errno, msg));
        }

        *newstate = zc.zc_cookie;
        return (0);
}

/*
 * Take the specified vdev offline
 */
int
zpool_vdev_offline(zpool_handle_t *zhp, const char *path, boolean_t istmp)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        nvlist_t *tgt;
        boolean_t avail_spare, l2cache;
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot offline %s"), path);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if ((tgt = zpool_find_vdev(zhp, path, &avail_spare, &l2cache,
            NULL)) == NULL)
                return (zfs_error(hdl, EZFS_NODEVICE, msg));

        verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID, &zc.zc_guid) == 0);

        if (avail_spare)
                return (zfs_error(hdl, EZFS_ISSPARE, msg));

        zc.zc_cookie = VDEV_STATE_OFFLINE;
        zc.zc_obj = istmp ? ZFS_OFFLINE_TEMPORARY : 0;

        if (zfs_ioctl(hdl, ZFS_IOC_VDEV_SET_STATE, &zc) == 0)
                return (0);

        switch (errno) {
        case EBUSY:

                /*
                 * There are no other replicas of this device.
                 */
                return (zfs_error(hdl, EZFS_NOREPLICAS, msg));

        case EEXIST:
                /*
                 * The log device has unplayed logs
                 */
                return (zfs_error(hdl, EZFS_UNPLAYED_LOGS, msg));

        default:
                return (zpool_standard_error(hdl, errno, msg));
        }
}

/*
 * Mark the given vdev faulted.
 */
int
zpool_vdev_fault(zpool_handle_t *zhp, uint64_t guid, vdev_aux_t aux)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot fault %llu"), (u_longlong_t)guid);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        zc.zc_guid = guid;
        zc.zc_cookie = VDEV_STATE_FAULTED;
        zc.zc_obj = aux;

        if (ioctl(hdl->libzfs_fd, ZFS_IOC_VDEV_SET_STATE, &zc) == 0)
                return (0);

        switch (errno) {
        case EBUSY:

                /*
                 * There are no other replicas of this device.
                 */
                return (zfs_error(hdl, EZFS_NOREPLICAS, msg));

        default:
                return (zpool_standard_error(hdl, errno, msg));
        }

}

/*
 * Mark the given vdev degraded.
 */
int
zpool_vdev_degrade(zpool_handle_t *zhp, uint64_t guid, vdev_aux_t aux)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot degrade %llu"), (u_longlong_t)guid);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        zc.zc_guid = guid;
        zc.zc_cookie = VDEV_STATE_DEGRADED;
        zc.zc_obj = aux;

        if (ioctl(hdl->libzfs_fd, ZFS_IOC_VDEV_SET_STATE, &zc) == 0)
                return (0);

        return (zpool_standard_error(hdl, errno, msg));
}

/*
 * Returns TRUE if the given nvlist is a vdev that was originally swapped in as
 * a hot spare.
 */
static boolean_t
is_replacing_spare(nvlist_t *search, nvlist_t *tgt, int which)
{
        nvlist_t **child;
        uint_t c, children;
        char *type;

        if (nvlist_lookup_nvlist_array(search, ZPOOL_CONFIG_CHILDREN, &child,
            &children) == 0) {
                verify(nvlist_lookup_string(search, ZPOOL_CONFIG_TYPE,
                    &type) == 0);

                if (strcmp(type, VDEV_TYPE_SPARE) == 0 &&
                    children == 2 && child[which] == tgt)
                        return (B_TRUE);

                for (c = 0; c < children; c++)
                        if (is_replacing_spare(child[c], tgt, which))
                                return (B_TRUE);
        }

        return (B_FALSE);
}

/*
 * Attach new_disk (fully described by nvroot) to old_disk.
 * If 'replacing' is specified, the new disk will replace the old one.
 */
int
zpool_vdev_attach(zpool_handle_t *zhp,
    const char *old_disk, const char *new_disk, nvlist_t *nvroot, int replacing)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        int ret;
        nvlist_t *tgt;
        boolean_t avail_spare, l2cache, islog;
        uint64_t val;
        char *newname;
        nvlist_t **child;
        uint_t children;
        nvlist_t *config_root;
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        boolean_t rootpool = zpool_is_bootable(zhp);

        if (replacing)
                (void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
                    "cannot replace %s with %s"), old_disk, new_disk);
        else
                (void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
                    "cannot attach %s to %s"), new_disk, old_disk);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if ((tgt = zpool_find_vdev(zhp, old_disk, &avail_spare, &l2cache,
            &islog)) == 0)
                return (zfs_error(hdl, EZFS_NODEVICE, msg));

        if (avail_spare)
                return (zfs_error(hdl, EZFS_ISSPARE, msg));

        if (l2cache)
                return (zfs_error(hdl, EZFS_ISL2CACHE, msg));

        verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID, &zc.zc_guid) == 0);
        zc.zc_cookie = replacing;

        if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
            &child, &children) != 0 || children != 1) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "new device must be a single disk"));
                return (zfs_error(hdl, EZFS_INVALCONFIG, msg));
        }

        verify(nvlist_lookup_nvlist(zpool_get_config(zhp, NULL),
            ZPOOL_CONFIG_VDEV_TREE, &config_root) == 0);

        if ((newname = zpool_vdev_name(NULL, NULL, child[0], 0)) == NULL)
                return (-1);

        /*
         * If the target is a hot spare that has been swapped in, we can only
         * replace it with another hot spare.
         */
        if (replacing &&
            nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_IS_SPARE, &val) == 0 &&
            (zpool_find_vdev(zhp, newname, &avail_spare, &l2cache,
            NULL) == NULL || !avail_spare) &&
            is_replacing_spare(config_root, tgt, 1)) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "can only be replaced by another hot spare"));
                free(newname);
                return (zfs_error(hdl, EZFS_BADTARGET, msg));
        }

        free(newname);

        if (zcmd_write_conf_nvlist(hdl, &zc, nvroot) != 0)
                return (-1);

        ret = zfs_ioctl(hdl, ZFS_IOC_VDEV_ATTACH, &zc);

        zcmd_free_nvlists(&zc);

        if (ret == 0) {
                if (rootpool) {
                        /*
                         * XXX need a better way to prevent user from
                         * booting up a half-baked vdev.
                         */
                        (void) fprintf(stderr, dgettext(TEXT_DOMAIN, "Make "
                            "sure to wait until resilver is done "
                            "before rebooting.\n"));
                }
                return (0);
        }

        switch (errno) {
        case ENOTSUP:
                /*
                 * Can't attach to or replace this type of vdev.
                 */
                if (replacing) {
                        uint64_t version = zpool_get_prop_int(zhp,
                            ZPOOL_PROP_VERSION, NULL);

                        if (islog)
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "cannot replace a log with a spare"));
                        else if (version >= SPA_VERSION_MULTI_REPLACE)
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "already in replacing/spare config; wait "
                                    "for completion or use 'zpool detach'"));
                        else
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "cannot replace a replacing device"));
                } else {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "can only attach to mirrors and top-level "
                            "disks"));
                }
                (void) zfs_error(hdl, EZFS_BADTARGET, msg);
                break;

        case EINVAL:
                /*
                 * The new device must be a single disk.
                 */
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "new device must be a single disk"));
                (void) zfs_error(hdl, EZFS_INVALCONFIG, msg);
                break;

        case EBUSY:
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "%s is busy"),
                    new_disk);
                (void) zfs_error(hdl, EZFS_BADDEV, msg);
                break;

        case EOVERFLOW:
                /*
                 * The new device is too small.
                 */
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "device is too small"));
                (void) zfs_error(hdl, EZFS_BADDEV, msg);
                break;

        case EDOM:
                /*
                 * The new device has a different optimal sector size.
                 */
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "new device has a different optimal sector size; use the "
                    "option '-o ashift=N' to override the optimal size"));
                (void) zfs_error(hdl, EZFS_BADDEV, msg);
                break;

        case ENAMETOOLONG:
                /*
                 * The resulting top-level vdev spec won't fit in the label.
                 */
                (void) zfs_error(hdl, EZFS_DEVOVERFLOW, msg);
                break;

        default:
                (void) zpool_standard_error(hdl, errno, msg);
        }

        return (-1);
}

/*
 * Detach the specified device.
 */
int
zpool_vdev_detach(zpool_handle_t *zhp, const char *path)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        nvlist_t *tgt;
        boolean_t avail_spare, l2cache;
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot detach %s"), path);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if ((tgt = zpool_find_vdev(zhp, path, &avail_spare, &l2cache,
            NULL)) == 0)
                return (zfs_error(hdl, EZFS_NODEVICE, msg));

        if (avail_spare)
                return (zfs_error(hdl, EZFS_ISSPARE, msg));

        if (l2cache)
                return (zfs_error(hdl, EZFS_ISL2CACHE, msg));

        verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID, &zc.zc_guid) == 0);

        if (zfs_ioctl(hdl, ZFS_IOC_VDEV_DETACH, &zc) == 0)
                return (0);

        switch (errno) {

        case ENOTSUP:
                /*
                 * Can't detach from this type of vdev.
                 */
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "only "
                    "applicable to mirror and replacing vdevs"));
                (void) zfs_error(hdl, EZFS_BADTARGET, msg);
                break;

        case EBUSY:
                /*
                 * There are no other replicas of this device.
                 */
                (void) zfs_error(hdl, EZFS_NOREPLICAS, msg);
                break;

        default:
                (void) zpool_standard_error(hdl, errno, msg);
        }

        return (-1);
}

/*
 * Find a mirror vdev in the source nvlist.
 *
 * The mchild array contains a list of disks in one of the top-level mirrors
 * of the source pool.  The schild array contains a list of disks that the
 * user specified on the command line.  We loop over the mchild array to
 * see if any entry in the schild array matches.
 *
 * If a disk in the mchild array is found in the schild array, we return
 * the index of that entry.  Otherwise we return -1.
 */
static int
find_vdev_entry(zpool_handle_t *zhp, nvlist_t **mchild, uint_t mchildren,
    nvlist_t **schild, uint_t schildren)
{
        uint_t mc;

        for (mc = 0; mc < mchildren; mc++) {
                uint_t sc;
                char *mpath = zpool_vdev_name(zhp->zpool_hdl, zhp,
                    mchild[mc], 0);

                for (sc = 0; sc < schildren; sc++) {
                        char *spath = zpool_vdev_name(zhp->zpool_hdl, zhp,
                            schild[sc], 0);
                        boolean_t result = (strcmp(mpath, spath) == 0);

                        free(spath);
                        if (result) {
                                free(mpath);
                                return (mc);
                        }
                }

                free(mpath);
        }

        return (-1);
}

/*
 * Split a mirror pool.  If newroot points to null, then a new nvlist
 * is generated and it is the responsibility of the caller to free it.
 */
int
zpool_vdev_split(zpool_handle_t *zhp, char *newname, nvlist_t **newroot,
    nvlist_t *props, splitflags_t flags)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        nvlist_t *tree, *config, **child, **newchild, *newconfig = NULL;
        nvlist_t **varray = NULL, *zc_props = NULL;
        uint_t c, children, newchildren, lastlog = 0, vcount, found = 0;
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        uint64_t vers;
        boolean_t freelist = B_FALSE, memory_err = B_TRUE;
        int retval = 0;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "Unable to split %s"), zhp->zpool_name);

        if (!zpool_name_valid(hdl, B_FALSE, newname))
                return (zfs_error(hdl, EZFS_INVALIDNAME, msg));

        if ((config = zpool_get_config(zhp, NULL)) == NULL) {
                (void) fprintf(stderr, gettext("Internal error: unable to "
                    "retrieve pool configuration\n"));
                return (-1);
        }

        verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &tree)
            == 0);
        verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION, &vers) == 0);

        if (props) {
                prop_flags_t flags = { .create = B_FALSE, .import = B_TRUE };
                if ((zc_props = zpool_valid_proplist(hdl, zhp->zpool_name,
                    props, vers, flags, msg)) == NULL)
                        return (-1);
        }

        if (nvlist_lookup_nvlist_array(tree, ZPOOL_CONFIG_CHILDREN, &child,
            &children) != 0) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "Source pool is missing vdev tree"));
                nvlist_free(zc_props);
                return (-1);
        }

        varray = zfs_alloc(hdl, children * sizeof (nvlist_t *));
        vcount = 0;

        if (*newroot == NULL ||
            nvlist_lookup_nvlist_array(*newroot, ZPOOL_CONFIG_CHILDREN,
            &newchild, &newchildren) != 0)
                newchildren = 0;

        for (c = 0; c < children; c++) {
                uint64_t is_log = B_FALSE, is_hole = B_FALSE;
                char *type;
                nvlist_t **mchild, *vdev;
                uint_t mchildren;
                int entry;

                /*
                 * Unlike cache & spares, slogs are stored in the
                 * ZPOOL_CONFIG_CHILDREN array.  We filter them out here.
                 */
                (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_LOG,
                    &is_log);
                (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
                    &is_hole);
                if (is_log || is_hole) {
                        /*
                         * Create a hole vdev and put it in the config.
                         */
                        if (nvlist_alloc(&vdev, NV_UNIQUE_NAME, 0) != 0)
                                goto out;
                        if (nvlist_add_string(vdev, ZPOOL_CONFIG_TYPE,
                            VDEV_TYPE_HOLE) != 0)
                                goto out;
                        if (nvlist_add_uint64(vdev, ZPOOL_CONFIG_IS_HOLE,
                            1) != 0)
                                goto out;
                        if (lastlog == 0)
                                lastlog = vcount;
                        varray[vcount++] = vdev;
                        continue;
                }
                lastlog = 0;
                verify(nvlist_lookup_string(child[c], ZPOOL_CONFIG_TYPE, &type)
                    == 0);
                if (strcmp(type, VDEV_TYPE_MIRROR) != 0) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "Source pool must be composed only of mirrors\n"));
                        retval = zfs_error(hdl, EZFS_INVALCONFIG, msg);
                        goto out;
                }

                verify(nvlist_lookup_nvlist_array(child[c],
                    ZPOOL_CONFIG_CHILDREN, &mchild, &mchildren) == 0);

                /* find or add an entry for this top-level vdev */
                if (newchildren > 0 &&
                    (entry = find_vdev_entry(zhp, mchild, mchildren,
                    newchild, newchildren)) >= 0) {
                        /* We found a disk that the user specified. */
                        vdev = mchild[entry];
                        ++found;
                } else {
                        /* User didn't specify a disk for this vdev. */
                        vdev = mchild[mchildren - 1];
                }

                if (nvlist_dup(vdev, &varray[vcount++], 0) != 0)
                        goto out;
        }

        /* did we find every disk the user specified? */
        if (found != newchildren) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "Device list must "
                    "include at most one disk from each mirror"));
                retval = zfs_error(hdl, EZFS_INVALCONFIG, msg);
                goto out;
        }

        /* Prepare the nvlist for populating. */
        if (*newroot == NULL) {
                if (nvlist_alloc(newroot, NV_UNIQUE_NAME, 0) != 0)
                        goto out;
                freelist = B_TRUE;
                if (nvlist_add_string(*newroot, ZPOOL_CONFIG_TYPE,
                    VDEV_TYPE_ROOT) != 0)
                        goto out;
        } else {
                verify(nvlist_remove_all(*newroot, ZPOOL_CONFIG_CHILDREN) == 0);
        }

        /* Add all the children we found */
        if (nvlist_add_nvlist_array(*newroot, ZPOOL_CONFIG_CHILDREN, varray,
            lastlog == 0 ? vcount : lastlog) != 0)
                goto out;

        /*
         * If we're just doing a dry run, exit now with success.
         */
        if (flags.dryrun) {
                memory_err = B_FALSE;
                freelist = B_FALSE;
                goto out;
        }

        /* now build up the config list & call the ioctl */
        if (nvlist_alloc(&newconfig, NV_UNIQUE_NAME, 0) != 0)
                goto out;

        if (nvlist_add_nvlist(newconfig,
            ZPOOL_CONFIG_VDEV_TREE, *newroot) != 0 ||
            nvlist_add_string(newconfig,
            ZPOOL_CONFIG_POOL_NAME, newname) != 0 ||
            nvlist_add_uint64(newconfig, ZPOOL_CONFIG_VERSION, vers) != 0)
                goto out;

        /*
         * The new pool is automatically part of the namespace unless we
         * explicitly export it.
         */
        if (!flags.import)
                zc.zc_cookie = ZPOOL_EXPORT_AFTER_SPLIT;
        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        (void) strlcpy(zc.zc_string, newname, sizeof (zc.zc_string));
        if (zcmd_write_conf_nvlist(hdl, &zc, newconfig) != 0)
                goto out;
        if (zc_props != NULL && zcmd_write_src_nvlist(hdl, &zc, zc_props) != 0)
                goto out;

        if (zfs_ioctl(hdl, ZFS_IOC_VDEV_SPLIT, &zc) != 0) {
                retval = zpool_standard_error(hdl, errno, msg);
                goto out;
        }

        freelist = B_FALSE;
        memory_err = B_FALSE;

out:
        if (varray != NULL) {
                int v;

                for (v = 0; v < vcount; v++)
                        nvlist_free(varray[v]);
                free(varray);
        }
        zcmd_free_nvlists(&zc);
        nvlist_free(zc_props);
        nvlist_free(newconfig);
        if (freelist) {
                nvlist_free(*newroot);
                *newroot = NULL;
        }

        if (retval != 0)
                return (retval);

        if (memory_err)
                return (no_memory(hdl));

        return (0);
}

/*
 * Remove the given device.  Currently, this is supported only for hot spares,
 * cache, and log devices.
 */
int
zpool_vdev_remove(zpool_handle_t *zhp, const char *path)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        nvlist_t *tgt;
        boolean_t avail_spare, l2cache, islog;
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        uint64_t version;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot remove %s"), path);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if ((tgt = zpool_find_vdev(zhp, path, &avail_spare, &l2cache,
            &islog)) == 0)
                return (zfs_error(hdl, EZFS_NODEVICE, msg));
        /*
         * XXX - this should just go away.
         */
        if (!avail_spare && !l2cache && !islog) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "only inactive hot spares, cache, "
                    "or log devices can be removed"));
                return (zfs_error(hdl, EZFS_NODEVICE, msg));
        }

        version = zpool_get_prop_int(zhp, ZPOOL_PROP_VERSION, NULL);
        if (islog && version < SPA_VERSION_HOLES) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "pool must be upgrade to support log removal"));
                return (zfs_error(hdl, EZFS_BADVERSION, msg));
        }

        verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID, &zc.zc_guid) == 0);

        if (zfs_ioctl(hdl, ZFS_IOC_VDEV_REMOVE, &zc) == 0)
                return (0);

        return (zpool_standard_error(hdl, errno, msg));
}

/*
 * Clear the errors for the pool, or the particular device if specified.
 */
int
zpool_clear(zpool_handle_t *zhp, const char *path, nvlist_t *rewindnvl)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        nvlist_t *tgt;
        zpool_rewind_policy_t policy;
        boolean_t avail_spare, l2cache;
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        nvlist_t *nvi = NULL;
        int error;

        if (path)
                (void) snprintf(msg, sizeof (msg),
                    dgettext(TEXT_DOMAIN, "cannot clear errors for %s"),
                    path);
        else
                (void) snprintf(msg, sizeof (msg),
                    dgettext(TEXT_DOMAIN, "cannot clear errors for %s"),
                    zhp->zpool_name);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if (path) {
                if ((tgt = zpool_find_vdev(zhp, path, &avail_spare,
                    &l2cache, NULL)) == 0)
                        return (zfs_error(hdl, EZFS_NODEVICE, msg));

                /*
                 * Don't allow error clearing for hot spares.  Do allow
                 * error clearing for l2cache devices.
                 */
                if (avail_spare)
                        return (zfs_error(hdl, EZFS_ISSPARE, msg));

                verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID,
                    &zc.zc_guid) == 0);
        }

        zpool_get_rewind_policy(rewindnvl, &policy);
        zc.zc_cookie = policy.zrp_request;

        if (zcmd_alloc_dst_nvlist(hdl, &zc, zhp->zpool_config_size * 2) != 0)
                return (-1);

        if (zcmd_write_src_nvlist(hdl, &zc, rewindnvl) != 0)
                return (-1);

        while ((error = zfs_ioctl(hdl, ZFS_IOC_CLEAR, &zc)) != 0 &&
            errno == ENOMEM) {
                if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
                        zcmd_free_nvlists(&zc);
                        return (-1);
                }
        }

        if (!error || ((policy.zrp_request & ZPOOL_TRY_REWIND) &&
            errno != EPERM && errno != EACCES)) {
                if (policy.zrp_request &
                    (ZPOOL_DO_REWIND | ZPOOL_TRY_REWIND)) {
                        (void) zcmd_read_dst_nvlist(hdl, &zc, &nvi);
                        zpool_rewind_exclaim(hdl, zc.zc_name,
                            ((policy.zrp_request & ZPOOL_TRY_REWIND) != 0),
                            nvi);
                        nvlist_free(nvi);
                }
                zcmd_free_nvlists(&zc);
                return (0);
        }

        zcmd_free_nvlists(&zc);
        return (zpool_standard_error(hdl, errno, msg));
}

/*
 * Similar to zpool_clear(), but takes a GUID (used by fmd).
 */
int
zpool_vdev_clear(zpool_handle_t *zhp, uint64_t guid)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot clear errors for %llx"),
            (u_longlong_t)guid);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        zc.zc_guid = guid;
        zc.zc_cookie = ZPOOL_NO_REWIND;

        if (ioctl(hdl->libzfs_fd, ZFS_IOC_CLEAR, &zc) == 0)
                return (0);

        return (zpool_standard_error(hdl, errno, msg));
}

/*
 * Change the GUID for a pool.
 */
int
zpool_reguid(zpool_handle_t *zhp)
{
        char msg[1024];
        libzfs_handle_t *hdl = zhp->zpool_hdl;
        zfs_cmd_t zc = {"\0"};

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot reguid '%s'"), zhp->zpool_name);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if (zfs_ioctl(hdl, ZFS_IOC_POOL_REGUID, &zc) == 0)
                return (0);

        return (zpool_standard_error(hdl, errno, msg));
}

/*
 * Reopen the pool.
 */
int
zpool_reopen(zpool_handle_t *zhp)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) snprintf(msg, sizeof (msg),
            dgettext(TEXT_DOMAIN, "cannot reopen '%s'"),
            zhp->zpool_name);

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        if (zfs_ioctl(hdl, ZFS_IOC_POOL_REOPEN, &zc) == 0)
                return (0);
        return (zpool_standard_error(hdl, errno, msg));
}

#if defined(__sun__) || defined(__sun)
/*
 * Convert from a devid string to a path.
 */
static char *
devid_to_path(char *devid_str)
{
        ddi_devid_t devid;
        char *minor;
        char *path;
        devid_nmlist_t *list = NULL;
        int ret;

        if (devid_str_decode(devid_str, &devid, &minor) != 0)
                return (NULL);

        ret = devid_deviceid_to_nmlist("/dev", devid, minor, &list);

        devid_str_free(minor);
        devid_free(devid);

        if (ret != 0)
                return (NULL);

        /*
         * In a case the strdup() fails, we will just return NULL below.
         */
        path = strdup(list[0].devname);

        devid_free_nmlist(list);

        return (path);
}

/*
 * Convert from a path to a devid string.
 */
static char *
path_to_devid(const char *path)
{
        int fd;
        ddi_devid_t devid;
        char *minor, *ret;

        if ((fd = open(path, O_RDONLY)) < 0)
                return (NULL);

        minor = NULL;
        ret = NULL;
        if (devid_get(fd, &devid) == 0) {
                if (devid_get_minor_name(fd, &minor) == 0)
                        ret = devid_str_encode(devid, minor);
                if (minor != NULL)
                        devid_str_free(minor);
                devid_free(devid);
        }
        (void) close(fd);

        return (ret);
}

/*
 * Issue the necessary ioctl() to update the stored path value for the vdev.  We
 * ignore any failure here, since a common case is for an unprivileged user to
 * type 'zpool status', and we'll display the correct information anyway.
 */
static void
set_path(zpool_handle_t *zhp, nvlist_t *nv, const char *path)
{
        zfs_cmd_t zc = {"\0"};

        (void) strncpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        (void) strncpy(zc.zc_value, path, sizeof (zc.zc_value));
        verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID,
            &zc.zc_guid) == 0);

        (void) ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_VDEV_SETPATH, &zc);
}
#endif /* sun */

/*
 * Remove partition suffix from a vdev path.  Partition suffixes may take three
 * forms: "-partX", "pX", or "X", where X is a string of digits.  The second
 * case only occurs when the suffix is preceded by a digit, i.e. "md0p0" The
 * third case only occurs when preceded by a string matching the regular
 * expression "^([hsv]|xv)d[a-z]+", i.e. a scsi, ide, virtio or xen disk.
 *
 * caller must free the returned string
 */
char *
zfs_strip_partition(char *path)
{
        char *tmp = strdup(path);
        char *part = NULL, *d = NULL;
        if (!tmp)
                return (NULL);

        if ((part = strstr(tmp, "-part")) && part != tmp) {
                d = part + 5;
        } else if ((part = strrchr(tmp, 'p')) &&
            part > tmp + 1 && isdigit(*(part-1))) {
                d = part + 1;
        } else if ((tmp[0] == 'h' || tmp[0] == 's' || tmp[0] == 'v') &&
            tmp[1] == 'd') {
                for (d = &tmp[2]; isalpha(*d); part = ++d) { }
        } else if (strncmp("xvd", tmp, 3) == 0) {
                for (d = &tmp[3]; isalpha(*d); part = ++d) { }
        }
        if (part && d && *d != '\0') {
                for (; isdigit(*d); d++) { }
                if (*d == '\0')
                        *part = '\0';
        }

        return (tmp);
}

/*
 * Same as zfs_strip_partition, but allows "/dev/" to be in the pathname
 *
 * path:        /dev/sda1
 * returns:     /dev/sda
 *
 * Returned string must be freed.
 */
char *
zfs_strip_partition_path(char *path)
{
        char *newpath = strdup(path);
        char *sd_offset;
        char *new_sd;

        if (!newpath)
                return (NULL);

        /* Point to "sda1" part of "/dev/sda1" */
        sd_offset = strrchr(newpath, '/') + 1;

        /* Get our new name "sda" */
        new_sd = zfs_strip_partition(sd_offset);
        if (!new_sd) {
                free(newpath);
                return (NULL);
        }

        /* Paste the "sda" where "sda1" was */
        strlcpy(sd_offset, new_sd, strlen(sd_offset) + 1);

        /* Free temporary "sda" */
        free(new_sd);

        return (newpath);
}

#define PATH_BUF_LEN    64

/*
 * Given a vdev, return the name to display in iostat.  If the vdev has a path,
 * we use that, stripping off any leading "/dev/dsk/"; if not, we use the type.
 * We also check if this is a whole disk, in which case we strip off the
 * trailing 's0' slice name.
 *
 * This routine is also responsible for identifying when disks have been
 * reconfigured in a new location.  The kernel will have opened the device by
 * devid, but the path will still refer to the old location.  To catch this, we
 * first do a path -> devid translation (which is fast for the common case).  If
 * the devid matches, we're done.  If not, we do a reverse devid -> path
 * translation and issue the appropriate ioctl() to update the path of the vdev.
 * If 'zhp' is NULL, then this is an exported pool, and we don't need to do any
 * of these checks.
 */
char *
zpool_vdev_name(libzfs_handle_t *hdl, zpool_handle_t *zhp, nvlist_t *nv,
    int name_flags)
{
        char *path, *type, *env;
        uint64_t value;
        char buf[PATH_BUF_LEN];
        char tmpbuf[PATH_BUF_LEN];

        env = getenv("ZPOOL_VDEV_NAME_PATH");
        if (env && (strtoul(env, NULL, 0) > 0 ||
            !strncasecmp(env, "YES", 3) || !strncasecmp(env, "ON", 2)))
                name_flags |= VDEV_NAME_PATH;

        env = getenv("ZPOOL_VDEV_NAME_GUID");
        if (env && (strtoul(env, NULL, 0) > 0 ||
            !strncasecmp(env, "YES", 3) || !strncasecmp(env, "ON", 2)))
                name_flags |= VDEV_NAME_GUID;

        env = getenv("ZPOOL_VDEV_NAME_FOLLOW_LINKS");
        if (env && (strtoul(env, NULL, 0) > 0 ||
            !strncasecmp(env, "YES", 3) || !strncasecmp(env, "ON", 2)))
                name_flags |= VDEV_NAME_FOLLOW_LINKS;

        if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT, &value) == 0 ||
            name_flags & VDEV_NAME_GUID) {
                (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &value);
                (void) snprintf(buf, sizeof (buf), "%llu", (u_longlong_t)value);
                path = buf;
        } else if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) == 0) {
#if defined(__sun__) || defined(__sun)
                /*
                 * Live VDEV path updates to a kernel VDEV during a
                 * zpool_vdev_name lookup are not supported on Linux.
                 */
                char *devid;
                vdev_stat_t *vs;
                uint_t vsc;

                /*
                 * If the device is dead (faulted, offline, etc) then don't
                 * bother opening it.  Otherwise we may be forcing the user to
                 * open a misbehaving device, which can have undesirable
                 * effects.
                 */
                if ((nvlist_lookup_uint64_array(nv, ZPOOL_CONFIG_VDEV_STATS,
                    (uint64_t **)&vs, &vsc) != 0 ||
                    vs->vs_state >= VDEV_STATE_DEGRADED) &&
                    zhp != NULL &&
                    nvlist_lookup_string(nv, ZPOOL_CONFIG_DEVID, &devid) == 0) {
                        /*
                         * Determine if the current path is correct.
                         */
                        char *newdevid = path_to_devid(path);

                        if (newdevid == NULL ||
                            strcmp(devid, newdevid) != 0) {
                                char *newpath;

                                if ((newpath = devid_to_path(devid)) != NULL) {
                                        /*
                                         * Update the path appropriately.
                                         */
                                        set_path(zhp, nv, newpath);
                                        if (nvlist_add_string(nv,
                                            ZPOOL_CONFIG_PATH, newpath) == 0)
                                                verify(nvlist_lookup_string(nv,
                                                    ZPOOL_CONFIG_PATH,
                                                    &path) == 0);
                                        free(newpath);
                                }
                        }

                        if (newdevid)
                                devid_str_free(newdevid);
                }
#endif /* sun */

                if (name_flags & VDEV_NAME_FOLLOW_LINKS) {
                        char *rp = realpath(path, NULL);
                        if (rp) {
                                strlcpy(buf, rp, sizeof (buf));
                                path = buf;
                                free(rp);
                        }
                }

                /*
                 * For a block device only use the name.
                 */
                verify(nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) == 0);
                if ((strcmp(type, VDEV_TYPE_DISK) == 0) &&
                    !(name_flags & VDEV_NAME_PATH)) {
                        path = strrchr(path, '/');
                        path++;
                }

                /*
                 * Remove the partition from the path it this is a whole disk.
                 */
                if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK, &value)
                    == 0 && value && !(name_flags & VDEV_NAME_PATH)) {
                        return (zfs_strip_partition(path));
                }
        } else {
                verify(nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &path) == 0);

                /*
                 * If it's a raidz device, we need to stick in the parity level.
                 */
                if (strcmp(path, VDEV_TYPE_RAIDZ) == 0) {
                        verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY,
                            &value) == 0);
                        (void) snprintf(buf, sizeof (buf), "%s%llu", path,
                            (u_longlong_t)value);
                        path = buf;
                }

                /*
                 * We identify each top-level vdev by using a <type-id>
                 * naming convention.
                 */
                if (name_flags & VDEV_NAME_TYPE_ID) {
                        uint64_t id;
                        verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ID,
                            &id) == 0);
                        (void) snprintf(tmpbuf, sizeof (tmpbuf), "%s-%llu",
                            path, (u_longlong_t)id);
                        path = tmpbuf;
                }
        }

        return (zfs_strdup(hdl, path));
}

static int
zbookmark_mem_compare(const void *a, const void *b)
{
        return (memcmp(a, b, sizeof (zbookmark_phys_t)));
}

/*
 * Retrieve the persistent error log, uniquify the members, and return to the
 * caller.
 */
int
zpool_get_errlog(zpool_handle_t *zhp, nvlist_t **nverrlistp)
{
        zfs_cmd_t zc = {"\0"};
        uint64_t count;
        zbookmark_phys_t *zb = NULL;
        int i;

        /*
         * Retrieve the raw error list from the kernel.  If the number of errors
         * has increased, allocate more space and continue until we get the
         * entire list.
         */
        verify(nvlist_lookup_uint64(zhp->zpool_config, ZPOOL_CONFIG_ERRCOUNT,
            &count) == 0);
        if (count == 0)
                return (0);
        if ((zc.zc_nvlist_dst = (uintptr_t)zfs_alloc(zhp->zpool_hdl,
            count * sizeof (zbookmark_phys_t))) == (uintptr_t)NULL)
                return (-1);
        zc.zc_nvlist_dst_size = count;
        (void) strcpy(zc.zc_name, zhp->zpool_name);
        for (;;) {
                if (ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_ERROR_LOG,
                    &zc) != 0) {
                        free((void *)(uintptr_t)zc.zc_nvlist_dst);
                        if (errno == ENOMEM) {
                                void *dst;

                                count = zc.zc_nvlist_dst_size;
                                dst = zfs_alloc(zhp->zpool_hdl, count *
                                    sizeof (zbookmark_phys_t));
                                if (dst == NULL)
                                        return (-1);
                                zc.zc_nvlist_dst = (uintptr_t)dst;
                        } else {
                                return (-1);
                        }
                } else {
                        break;
                }
        }

        /*
         * Sort the resulting bookmarks.  This is a little confusing due to the
         * implementation of ZFS_IOC_ERROR_LOG.  The bookmarks are copied last
         * to first, and 'zc_nvlist_dst_size' indicates the number of boomarks
         * _not_ copied as part of the process.  So we point the start of our
         * array appropriate and decrement the total number of elements.
         */
        zb = ((zbookmark_phys_t *)(uintptr_t)zc.zc_nvlist_dst) +
            zc.zc_nvlist_dst_size;
        count -= zc.zc_nvlist_dst_size;

        qsort(zb, count, sizeof (zbookmark_phys_t), zbookmark_mem_compare);

        verify(nvlist_alloc(nverrlistp, 0, KM_SLEEP) == 0);

        /*
         * Fill in the nverrlistp with nvlist's of dataset and object numbers.
         */
        for (i = 0; i < count; i++) {
                nvlist_t *nv;

                /* ignoring zb_blkid and zb_level for now */
                if (i > 0 && zb[i-1].zb_objset == zb[i].zb_objset &&
                    zb[i-1].zb_object == zb[i].zb_object)
                        continue;

                if (nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) != 0)
                        goto nomem;
                if (nvlist_add_uint64(nv, ZPOOL_ERR_DATASET,
                    zb[i].zb_objset) != 0) {
                        nvlist_free(nv);
                        goto nomem;
                }
                if (nvlist_add_uint64(nv, ZPOOL_ERR_OBJECT,
                    zb[i].zb_object) != 0) {
                        nvlist_free(nv);
                        goto nomem;
                }
                if (nvlist_add_nvlist(*nverrlistp, "ejk", nv) != 0) {
                        nvlist_free(nv);
                        goto nomem;
                }
                nvlist_free(nv);
        }

        free((void *)(uintptr_t)zc.zc_nvlist_dst);
        return (0);

nomem:
        free((void *)(uintptr_t)zc.zc_nvlist_dst);
        return (no_memory(zhp->zpool_hdl));
}

/*
 * Upgrade a ZFS pool to the latest on-disk version.
 */
int
zpool_upgrade(zpool_handle_t *zhp, uint64_t new_version)
{
        zfs_cmd_t zc = {"\0"};
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) strcpy(zc.zc_name, zhp->zpool_name);
        zc.zc_cookie = new_version;

        if (zfs_ioctl(hdl, ZFS_IOC_POOL_UPGRADE, &zc) != 0)
                return (zpool_standard_error_fmt(hdl, errno,
                    dgettext(TEXT_DOMAIN, "cannot upgrade '%s'"),
                    zhp->zpool_name));
        return (0);
}

void
zfs_save_arguments(int argc, char **argv, char *string, int len)
{
        int i;

        (void) strlcpy(string, basename(argv[0]), len);
        for (i = 1; i < argc; i++) {
                (void) strlcat(string, " ", len);
                (void) strlcat(string, argv[i], len);
        }
}

int
zpool_log_history(libzfs_handle_t *hdl, const char *message)
{
        zfs_cmd_t zc = {"\0"};
        nvlist_t *args;
        int err;

        args = fnvlist_alloc();
        fnvlist_add_string(args, "message", message);
        err = zcmd_write_src_nvlist(hdl, &zc, args);
        if (err == 0)
                err = ioctl(hdl->libzfs_fd, ZFS_IOC_LOG_HISTORY, &zc);
        nvlist_free(args);
        zcmd_free_nvlists(&zc);
        return (err);
}

/*
 * Perform ioctl to get some command history of a pool.
 *
 * 'buf' is the buffer to fill up to 'len' bytes.  'off' is the
 * logical offset of the history buffer to start reading from.
 *
 * Upon return, 'off' is the next logical offset to read from and
 * 'len' is the actual amount of bytes read into 'buf'.
 */
static int
get_history(zpool_handle_t *zhp, char *buf, uint64_t *off, uint64_t *len)
{
        zfs_cmd_t zc = {"\0"};
        libzfs_handle_t *hdl = zhp->zpool_hdl;

        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));

        zc.zc_history = (uint64_t)(uintptr_t)buf;
        zc.zc_history_len = *len;
        zc.zc_history_offset = *off;

        if (ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_GET_HISTORY, &zc) != 0) {
                switch (errno) {
                case EPERM:
                        return (zfs_error_fmt(hdl, EZFS_PERM,
                            dgettext(TEXT_DOMAIN,
                            "cannot show history for pool '%s'"),
                            zhp->zpool_name));
                case ENOENT:
                        return (zfs_error_fmt(hdl, EZFS_NOHISTORY,
                            dgettext(TEXT_DOMAIN, "cannot get history for pool "
                            "'%s'"), zhp->zpool_name));
                case ENOTSUP:
                        return (zfs_error_fmt(hdl, EZFS_BADVERSION,
                            dgettext(TEXT_DOMAIN, "cannot get history for pool "
                            "'%s', pool must be upgraded"), zhp->zpool_name));
                default:
                        return (zpool_standard_error_fmt(hdl, errno,
                            dgettext(TEXT_DOMAIN,
                            "cannot get history for '%s'"), zhp->zpool_name));
                }
        }

        *len = zc.zc_history_len;
        *off = zc.zc_history_offset;

        return (0);
}

/*
 * Process the buffer of nvlists, unpacking and storing each nvlist record
 * into 'records'.  'leftover' is set to the number of bytes that weren't
 * processed as there wasn't a complete record.
 */
int
zpool_history_unpack(char *buf, uint64_t bytes_read, uint64_t *leftover,
    nvlist_t ***records, uint_t *numrecords)
{
        uint64_t reclen;
        nvlist_t *nv;
        int i;
        void *tmp;

        while (bytes_read > sizeof (reclen)) {

                /* get length of packed record (stored as little endian) */
                for (i = 0, reclen = 0; i < sizeof (reclen); i++)
                        reclen += (uint64_t)(((uchar_t *)buf)[i]) << (8*i);

                if (bytes_read < sizeof (reclen) + reclen)
                        break;

                /* unpack record */
                if (nvlist_unpack(buf + sizeof (reclen), reclen, &nv, 0) != 0)
                        return (ENOMEM);
                bytes_read -= sizeof (reclen) + reclen;
                buf += sizeof (reclen) + reclen;

                /* add record to nvlist array */
                (*numrecords)++;
                if (ISP2(*numrecords + 1)) {
                        tmp = realloc(*records,
                            *numrecords * 2 * sizeof (nvlist_t *));
                        if (tmp == NULL) {
                                nvlist_free(nv);
                                (*numrecords)--;
                                return (ENOMEM);
                        }
                        *records = tmp;
                }
                (*records)[*numrecords - 1] = nv;
        }

        *leftover = bytes_read;
        return (0);
}

/*
 * Retrieve the command history of a pool.
 */
int
zpool_get_history(zpool_handle_t *zhp, nvlist_t **nvhisp)
{
        char *buf;
        int buflen = 128 * 1024;
        uint64_t off = 0;
        nvlist_t **records = NULL;
        uint_t numrecords = 0;
        int err, i;

        buf = malloc(buflen);
        if (buf == NULL)
                return (ENOMEM);
        do {
                uint64_t bytes_read = buflen;
                uint64_t leftover;

                if ((err = get_history(zhp, buf, &off, &bytes_read)) != 0)
                        break;

                /* if nothing else was read in, we're at EOF, just return */
                if (!bytes_read)
                        break;

                if ((err = zpool_history_unpack(buf, bytes_read,
                    &leftover, &records, &numrecords)) != 0)
                        break;
                off -= leftover;
                if (leftover == bytes_read) {
                        /*
                         * no progress made, because buffer is not big enough
                         * to hold this record; resize and retry.
                         */
                        buflen *= 2;
                        free(buf);
                        buf = malloc(buflen);
                        if (buf == NULL)
                                return (ENOMEM);
                }

                /* CONSTCOND */
        } while (1);

        free(buf);

        if (!err) {
                verify(nvlist_alloc(nvhisp, NV_UNIQUE_NAME, 0) == 0);
                verify(nvlist_add_nvlist_array(*nvhisp, ZPOOL_HIST_RECORD,
                    records, numrecords) == 0);
        }
        for (i = 0; i < numrecords; i++)
                nvlist_free(records[i]);
        free(records);

        return (err);
}

/*
 * Retrieve the next event given the passed 'zevent_fd' file descriptor.
 * If there is a new event available 'nvp' will contain a newly allocated
 * nvlist and 'dropped' will be set to the number of missed events since
 * the last call to this function.  When 'nvp' is set to NULL it indicates
 * no new events are available.  In either case the function returns 0 and
 * it is up to the caller to free 'nvp'.  In the case of a fatal error the
 * function will return a non-zero value.  When the function is called in
 * blocking mode (the default, unless the ZEVENT_NONBLOCK flag is passed),
 * it will not return until a new event is available.
 */
int
zpool_events_next(libzfs_handle_t *hdl, nvlist_t **nvp,
    int *dropped, unsigned flags, int zevent_fd)
{
        zfs_cmd_t zc = {"\0"};
        int error = 0;

        *nvp = NULL;
        *dropped = 0;
        zc.zc_cleanup_fd = zevent_fd;

        if (flags & ZEVENT_NONBLOCK)
                zc.zc_guid = ZEVENT_NONBLOCK;

        if (zcmd_alloc_dst_nvlist(hdl, &zc, ZEVENT_SIZE) != 0)
                return (-1);

retry:
        if (zfs_ioctl(hdl, ZFS_IOC_EVENTS_NEXT, &zc) != 0) {
                switch (errno) {
                case ESHUTDOWN:
                        error = zfs_error_fmt(hdl, EZFS_POOLUNAVAIL,
                            dgettext(TEXT_DOMAIN, "zfs shutdown"));
                        goto out;
                case ENOENT:
                        /* Blocking error case should not occur */
                        if (!(flags & ZEVENT_NONBLOCK))
                                error = zpool_standard_error_fmt(hdl, errno,
                                    dgettext(TEXT_DOMAIN, "cannot get event"));

                        goto out;
                case ENOMEM:
                        if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
                                error = zfs_error_fmt(hdl, EZFS_NOMEM,
                                    dgettext(TEXT_DOMAIN, "cannot get event"));
                                goto out;
                        } else {
                                goto retry;
                        }
                default:
                        error = zpool_standard_error_fmt(hdl, errno,
                            dgettext(TEXT_DOMAIN, "cannot get event"));
                        goto out;
                }
        }

        error = zcmd_read_dst_nvlist(hdl, &zc, nvp);
        if (error != 0)
                goto out;

        *dropped = (int)zc.zc_cookie;
out:
        zcmd_free_nvlists(&zc);

        return (error);
}

/*
 * Clear all events.
 */
int
zpool_events_clear(libzfs_handle_t *hdl, int *count)
{
        zfs_cmd_t zc = {"\0"};
        char msg[1024];

        (void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
            "cannot clear events"));

        if (zfs_ioctl(hdl, ZFS_IOC_EVENTS_CLEAR, &zc) != 0)
                return (zpool_standard_error_fmt(hdl, errno, msg));

        if (count != NULL)
                *count = (int)zc.zc_cookie; /* # of events cleared */

        return (0);
}

/*
 * Seek to a specific EID, ZEVENT_SEEK_START, or ZEVENT_SEEK_END for
 * the passed zevent_fd file handle.  On success zero is returned,
 * otherwise -1 is returned and hdl->libzfs_error is set to the errno.
 */
int
zpool_events_seek(libzfs_handle_t *hdl, uint64_t eid, int zevent_fd)
{
        zfs_cmd_t zc = {"\0"};
        int error = 0;

        zc.zc_guid = eid;
        zc.zc_cleanup_fd = zevent_fd;

        if (zfs_ioctl(hdl, ZFS_IOC_EVENTS_SEEK, &zc) != 0) {
                switch (errno) {
                case ENOENT:
                        error = zfs_error_fmt(hdl, EZFS_NOENT,
                            dgettext(TEXT_DOMAIN, "cannot get event"));
                        break;

                case ENOMEM:
                        error = zfs_error_fmt(hdl, EZFS_NOMEM,
                            dgettext(TEXT_DOMAIN, "cannot get event"));
                        break;

                default:
                        error = zpool_standard_error_fmt(hdl, errno,
                            dgettext(TEXT_DOMAIN, "cannot get event"));
                        break;
                }
        }

        return (error);
}

void
zpool_obj_to_path(zpool_handle_t *zhp, uint64_t dsobj, uint64_t obj,
    char *pathname, size_t len)
{
        zfs_cmd_t zc = {"\0"};
        boolean_t mounted = B_FALSE;
        char *mntpnt = NULL;
        char dsname[ZFS_MAX_DATASET_NAME_LEN];

        if (dsobj == 0) {
                /* special case for the MOS */
                (void) snprintf(pathname, len, "<metadata>:<0x%llx>",
                    (longlong_t)obj);
                return;
        }

        /* get the dataset's name */
        (void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
        zc.zc_obj = dsobj;
        if (ioctl(zhp->zpool_hdl->libzfs_fd,
            ZFS_IOC_DSOBJ_TO_DSNAME, &zc) != 0) {
                /* just write out a path of two object numbers */
                (void) snprintf(pathname, len, "<0x%llx>:<0x%llx>",
                    (longlong_t)dsobj, (longlong_t)obj);
                return;
        }
        (void) strlcpy(dsname, zc.zc_value, sizeof (dsname));

        /* find out if the dataset is mounted */
        mounted = is_mounted(zhp->zpool_hdl, dsname, &mntpnt);

        /* get the corrupted object's path */
        (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name));
        zc.zc_obj = obj;
        if (ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_OBJ_TO_PATH,
            &zc) == 0) {
                if (mounted) {
                        (void) snprintf(pathname, len, "%s%s", mntpnt,
                            zc.zc_value);
                } else {
                        (void) snprintf(pathname, len, "%s:%s",
                            dsname, zc.zc_value);
                }
        } else {
                (void) snprintf(pathname, len, "%s:<0x%llx>", dsname,
                    (longlong_t)obj);
        }
        free(mntpnt);
}

/*
 * Read the EFI label from the config, if a label does not exist then
 * pass back the error to the caller. If the caller has passed a non-NULL
 * diskaddr argument then we set it to the starting address of the EFI
 * partition.
 */
static int
read_efi_label(nvlist_t *config, diskaddr_t *sb)
{
        char *path;
        int fd;
        char diskname[MAXPATHLEN];
        int err = -1;

        if (nvlist_lookup_string(config, ZPOOL_CONFIG_PATH, &path) != 0)
                return (err);

        (void) snprintf(diskname, sizeof (diskname), "%s%s", DISK_ROOT,
            strrchr(path, '/'));
        if ((fd = open(diskname, O_RDWR|O_DIRECT)) >= 0) {
                struct dk_gpt *vtoc;

                if ((err = efi_alloc_and_read(fd, &vtoc)) >= 0) {
                        if (sb != NULL)
                                *sb = vtoc->efi_parts[0].p_start;
                        efi_free(vtoc);
                }
                (void) close(fd);
        }
        return (err);
}

/*
 * determine where a partition starts on a disk in the current
 * configuration
 */
static diskaddr_t
find_start_block(nvlist_t *config)
{
        nvlist_t **child;
        uint_t c, children;
        diskaddr_t sb = MAXOFFSET_T;
        uint64_t wholedisk;

        if (nvlist_lookup_nvlist_array(config,
            ZPOOL_CONFIG_CHILDREN, &child, &children) != 0) {
                if (nvlist_lookup_uint64(config,
                    ZPOOL_CONFIG_WHOLE_DISK,
                    &wholedisk) != 0 || !wholedisk) {
                        return (MAXOFFSET_T);
                }
                if (read_efi_label(config, &sb) < 0)
                        sb = MAXOFFSET_T;
                return (sb);
        }

        for (c = 0; c < children; c++) {
                sb = find_start_block(child[c]);
                if (sb != MAXOFFSET_T) {
                        return (sb);
                }
        }
        return (MAXOFFSET_T);
}

static int
zpool_label_disk_check(char *path)
{
        struct dk_gpt *vtoc;
        int fd, err;

        if ((fd = open(path, O_RDWR|O_DIRECT)) < 0)
                return (errno);

        if ((err = efi_alloc_and_read(fd, &vtoc)) != 0) {
                (void) close(fd);
                return (err);
        }

        if (vtoc->efi_flags & EFI_GPT_PRIMARY_CORRUPT) {
                efi_free(vtoc);
                (void) close(fd);
                return (EIDRM);
        }

        efi_free(vtoc);
        (void) close(fd);
        return (0);
}

/*
 * Generate a unique partition name for the ZFS member.  Partitions must
 * have unique names to ensure udev will be able to create symlinks under
 * /dev/disk/by-partlabel/ for all pool members.  The partition names are
 * of the form <pool>-<unique-id>.
 */
static void
zpool_label_name(char *label_name, int label_size)
{
        uint64_t id = 0;
        int fd;

        fd = open("/dev/urandom", O_RDONLY);
        if (fd >= 0) {
                if (read(fd, &id, sizeof (id)) != sizeof (id))
                        id = 0;

                close(fd);
        }

        if (id == 0)
                id = (((uint64_t)rand()) << 32) | (uint64_t)rand();

        snprintf(label_name, label_size, "zfs-%016llx", (u_longlong_t)id);
}

/*
 * Label an individual disk.  The name provided is the short name,
 * stripped of any leading /dev path.
 */
int
zpool_label_disk(libzfs_handle_t *hdl, zpool_handle_t *zhp, char *name)
{
        char path[MAXPATHLEN];
        struct dk_gpt *vtoc;
        int rval, fd;
        size_t resv = EFI_MIN_RESV_SIZE;
        uint64_t slice_size;
        diskaddr_t start_block;
        char errbuf[1024];

        /* prepare an error message just in case */
        (void) snprintf(errbuf, sizeof (errbuf),
            dgettext(TEXT_DOMAIN, "cannot label '%s'"), name);

        if (zhp) {
                nvlist_t *nvroot;

                verify(nvlist_lookup_nvlist(zhp->zpool_config,
                    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);

                if (zhp->zpool_start_block == 0)
                        start_block = find_start_block(nvroot);
                else
                        start_block = zhp->zpool_start_block;
                zhp->zpool_start_block = start_block;
        } else {
                /* new pool */
                start_block = NEW_START_BLOCK;
        }

        (void) snprintf(path, sizeof (path), "%s/%s", DISK_ROOT, name);

        if ((fd = open(path, O_RDWR|O_DIRECT|O_EXCL)) < 0) {
                /*
                 * This shouldn't happen.  We've long since verified that this
                 * is a valid device.
                 */
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "cannot "
                    "label '%s': unable to open device: %d"), path, errno);
                return (zfs_error(hdl, EZFS_OPENFAILED, errbuf));
        }

        if (efi_alloc_and_init(fd, EFI_NUMPAR, &vtoc) != 0) {
                /*
                 * The only way this can fail is if we run out of memory, or we
                 * were unable to read the disk's capacity
                 */
                if (errno == ENOMEM)
                        (void) no_memory(hdl);

                (void) close(fd);
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "cannot "
                    "label '%s': unable to read disk capacity"), path);

                return (zfs_error(hdl, EZFS_NOCAP, errbuf));
        }

        slice_size = vtoc->efi_last_u_lba + 1;
        slice_size -= EFI_MIN_RESV_SIZE;
        if (start_block == MAXOFFSET_T)
                start_block = NEW_START_BLOCK;
        slice_size -= start_block;
        slice_size = P2ALIGN(slice_size, PARTITION_END_ALIGNMENT);

        vtoc->efi_parts[0].p_start = start_block;
        vtoc->efi_parts[0].p_size = slice_size;

        /*
         * Why we use V_USR: V_BACKUP confuses users, and is considered
         * disposable by some EFI utilities (since EFI doesn't have a backup
         * slice).  V_UNASSIGNED is supposed to be used only for zero size
         * partitions, and efi_write() will fail if we use it.  V_ROOT, V_BOOT,
         * etc. were all pretty specific.  V_USR is as close to reality as we
         * can get, in the absence of V_OTHER.
         */
        vtoc->efi_parts[0].p_tag = V_USR;
        zpool_label_name(vtoc->efi_parts[0].p_name, EFI_PART_NAME_LEN);

        vtoc->efi_parts[8].p_start = slice_size + start_block;
        vtoc->efi_parts[8].p_size = resv;
        vtoc->efi_parts[8].p_tag = V_RESERVED;

        if ((rval = efi_write(fd, vtoc)) != 0 || (rval = efi_rescan(fd)) != 0) {
                /*
                 * Some block drivers (like pcata) may not support EFI
                 * GPT labels.  Print out a helpful error message dir-
                 * ecting the user to manually label the disk and give
                 * a specific slice.
                 */
                (void) close(fd);
                efi_free(vtoc);

                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "try using "
                    "parted(8) and then provide a specific slice: %d"), rval);
                return (zfs_error(hdl, EZFS_LABELFAILED, errbuf));
        }

        (void) close(fd);
        efi_free(vtoc);

        (void) snprintf(path, sizeof (path), "%s/%s", DISK_ROOT, name);
        (void) zfs_append_partition(path, MAXPATHLEN);

        /* Wait to udev to signal use the device has settled. */
        rval = zpool_label_disk_wait(path, DISK_LABEL_WAIT);
        if (rval) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "failed to "
                    "detect device partitions on '%s': %d"), path, rval);
                return (zfs_error(hdl, EZFS_LABELFAILED, errbuf));
        }

        /* We can't be to paranoid.  Read the label back and verify it. */
        (void) snprintf(path, sizeof (path), "%s/%s", DISK_ROOT, name);
        rval = zpool_label_disk_check(path);
        if (rval) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "freshly written "
                    "EFI label on '%s' is damaged.  Ensure\nthis device "
                    "is not in in use, and is functioning properly: %d"),
                    path, rval);
                return (zfs_error(hdl, EZFS_LABELFAILED, errbuf));
        }

        return (0);
}

/*
 * Allocate and return the underlying device name for a device mapper device.
 * If a device mapper device maps to multiple devices, return the first device.
 *
 * For example, dm_name = "/dev/dm-0" could return "/dev/sda". Symlinks to a
 * DM device (like /dev/disk/by-vdev/A0) are also allowed.
 *
 * Returns device name, or NULL on error or no match.  If dm_name is not a DM
 * device then return NULL.
 *
 * NOTE: The returned name string must be *freed*.
 */
char *
dm_get_underlying_path(char *dm_name)
{
        DIR *dp = NULL;
        struct dirent *ep;
        char *realp;
        char *tmp = NULL;
        char *path = NULL;
        char *dev_str;
        int size;

        if (dm_name == NULL)
                return (NULL);

        /* dm name may be a symlink (like /dev/disk/by-vdev/A0) */
        realp = realpath(dm_name, NULL);
        if (realp == NULL)
                return (NULL);

        /*
         * If they preface 'dev' with a path (like "/dev") then strip it off.
         * We just want the 'dm-N' part.
         */
        tmp = strrchr(realp, '/');
        if (tmp != NULL)
                dev_str = tmp + 1;    /* +1 since we want the chr after '/' */
        else
                dev_str = tmp;

        size = asprintf(&tmp, "/sys/block/%s/slaves/", dev_str);
        if (size == -1 || !tmp)
                goto end;

        dp = opendir(tmp);
        if (dp == NULL)
                goto end;

        /* Return first sd* entry in /sys/block/dm-N/slaves/ */
        while ((ep = readdir(dp))) {
                if (ep->d_type != DT_DIR) {     /* skip "." and ".." dirs */
                        size = asprintf(&path, "/dev/%s", ep->d_name);
                        break;
                }
        }

end:
        if (dp != NULL)
                closedir(dp);
        free(tmp);
        free(realp);
        return (path);
}

/*
 * Return 1 if device is a device mapper or multipath device.
 * Return 0 if not.
 */
int
zfs_dev_is_dm(char *dev_name)
{

        char *tmp;
        tmp = dm_get_underlying_path(dev_name);
        if (tmp == NULL)
                return (0);

        free(tmp);
        return (1);
}

/*
 * Lookup the underlying device for a device name
 *
 * Often you'll have a symlink to a device, a partition device,
 * or a multipath device, and want to look up the underlying device.
 * This function returns the underlying device name.  If the device
 * name is already the underlying device, then just return the same
 * name.  If the device is a DM device with multiple underlying devices
 * then return the first one.
 *
 * For example:
 *
 * 1. /dev/disk/by-id/ata-QEMU_HARDDISK_QM00001 -> ../../sda
 * dev_name:    /dev/disk/by-id/ata-QEMU_HARDDISK_QM00001
 * returns:     /dev/sda
 *
 * 2. /dev/mapper/mpatha (made up of /dev/sda and /dev/sdb)
 * dev_name:    /dev/mapper/mpatha
 * returns:     /dev/sda (first device)
 *
 * 3. /dev/sda (already the underlying device)
 * dev_name:    /dev/sda
 * returns:     /dev/sda
 *
 * 4. /dev/dm-3 (mapped to /dev/sda)
 * dev_name:    /dev/dm-3
 * returns:     /dev/sda
 *
 * 5. /dev/disk/by-id/scsi-0QEMU_drive-scsi0-0-0-0-part9 -> ../../sdb9
 * dev_name:    /dev/disk/by-id/scsi-0QEMU_drive-scsi0-0-0-0-part9
 * returns:     /dev/sdb
 *
 * 6. /dev/disk/by-uuid/5df030cf-3cd9-46e4-8e99-3ccb462a4e9a -> ../dev/sda2
 * dev_name:    /dev/disk/by-uuid/5df030cf-3cd9-46e4-8e99-3ccb462a4e9a
 * returns:     /dev/sda
 *
 * Returns underlying device name, or NULL on error or no match.
 *
 * NOTE: The returned name string must be *freed*.
 */
char *
zfs_get_underlying_path(char *dev_name)
{
        char *name = NULL;
        char *tmp;

        if (dev_name == NULL)
                return (NULL);

        tmp = dm_get_underlying_path(dev_name);

        /* dev_name not a DM device, so just un-symlinkize it */
        if (tmp == NULL)
                tmp = realpath(dev_name, NULL);

        if (tmp != NULL) {
                name = zfs_strip_partition_path(tmp);
                free(tmp);
        }

        return (name);
}

/*
 * Given a dev name like "sda", return the full enclosure sysfs path to
 * the disk.  You can also pass in the name with "/dev" prepended
 * to it (like /dev/sda).
 *
 * For example, disk "sda" in enclosure slot 1:
 *     dev:            "sda"
 *     returns:        "/sys/class/enclosure/1:0:3:0/Slot 1"
 *
 * 'dev' must be a non-devicemapper device.
 *
 * Returned string must be freed.
 */
char *
zfs_get_enclosure_sysfs_path(char *dev_name)
{
        DIR *dp = NULL;
        struct dirent *ep;
        char buf[MAXPATHLEN];
        char *tmp1 = NULL;
        char *tmp2 = NULL;
        char *tmp3 = NULL;
        char *path = NULL;
        size_t size;
        int tmpsize;

        if (dev_name == NULL)
                return (NULL);

        /* If they preface 'dev' with a path (like "/dev") then strip it off */
        tmp1 = strrchr(dev_name, '/');
        if (tmp1 != NULL)
                dev_name = tmp1 + 1;    /* +1 since we want the chr after '/' */

        tmpsize = asprintf(&tmp1, "/sys/block/%s/device", dev_name);
        if (tmpsize == -1 || tmp1 == NULL) {
                tmp1 = NULL;
                goto end;
        }

        dp = opendir(tmp1);
        if (dp == NULL) {
                tmp1 = NULL;    /* To make free() at the end a NOP */
                goto end;
        }

        /*
         * Look though all sysfs entries in /sys/block/<dev>/device for
         * the enclosure symlink.
         */
        while ((ep = readdir(dp))) {
                /* Ignore everything that's not our enclosure_device link */
                if (strstr(ep->d_name, "enclosure_device") == NULL)
                        continue;

                if (asprintf(&tmp2, "%s/%s", tmp1, ep->d_name) == -1 ||
                    tmp2 == NULL)
                        break;

                size = readlink(tmp2, buf, sizeof (buf));

                /* Did readlink fail or crop the link name? */
                if (size == -1 || size >= sizeof (buf)) {
                        free(tmp2);
                        tmp2 = NULL;    /* To make free() at the end a NOP */
                        break;
                }

                /*
                 * We got a valid link.  readlink() doesn't terminate strings
                 * so we have to do it.
                 */
                buf[size] = '\0';

                /*
                 * Our link will look like:
                 *
                 * "../../../../port-11:1:2/..STUFF../enclosure/1:0:3:0/SLOT 1"
                 *
                 * We want to grab the "enclosure/1:0:3:0/SLOT 1" part
                 */
                tmp3 = strstr(buf, "enclosure");
                if (tmp3 == NULL)
                        break;

                if (asprintf(&path, "/sys/class/%s", tmp3) == -1) {
                        /* If asprintf() fails, 'path' is undefined */
                        path = NULL;
                        break;
                }

                if (path == NULL)
                        break;
        }

end:
        free(tmp2);
        free(tmp1);

        if (dp != NULL)
                closedir(dp);

        return (path);
}