Patrick Welche <prlw1@cam.ac.uk>

[netbsd-mini2440.git] / external / cddl / osnet / dist / lib / libzfs / common / libzfs_dataset.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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <libdevinfo.h>
#include <libintl.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <stddef.h>
#include <zone.h>
#include <fcntl.h>
#include <sys/mntent.h>
#include <sys/mnttab.h>
#include <sys/mount.h>
#include <sys/avl.h>
#include <priv.h>
#include <pwd.h>
#include <grp.h>
#include <stddef.h>
#include <ucred.h>

#include <sys/spa.h>
#include <sys/zap.h>
#include <libzfs.h>

#include "zfs_namecheck.h"
#include "zfs_prop.h"
#include "libzfs_impl.h"
#include "zfs_deleg.h"

static int zvol_create_link_common(libzfs_handle_t *, const char *, int);

/*
 * Given a single type (not a mask of types), return the type in a human
 * readable form.
 */
const char *
zfs_type_to_name(zfs_type_t type)
{
        switch (type) {
        case ZFS_TYPE_FILESYSTEM:
                return (dgettext(TEXT_DOMAIN, "filesystem"));
        case ZFS_TYPE_SNAPSHOT:
                return (dgettext(TEXT_DOMAIN, "snapshot"));
        case ZFS_TYPE_VOLUME:
                return (dgettext(TEXT_DOMAIN, "volume"));
        }

        return (NULL);
}

/*
 * Given a path and mask of ZFS types, return a string describing this dataset.
 * This is used when we fail to open a dataset and we cannot get an exact type.
 * We guess what the type would have been based on the path and the mask of
 * acceptable types.
 */
static const char *
path_to_str(const char *path, int types)
{
        /*
         * When given a single type, always report the exact type.
         */
        if (types == ZFS_TYPE_SNAPSHOT)
                return (dgettext(TEXT_DOMAIN, "snapshot"));
        if (types == ZFS_TYPE_FILESYSTEM)
                return (dgettext(TEXT_DOMAIN, "filesystem"));
        if (types == ZFS_TYPE_VOLUME)
                return (dgettext(TEXT_DOMAIN, "volume"));

        /*
         * The user is requesting more than one type of dataset.  If this is the
         * case, consult the path itself.  If we're looking for a snapshot, and
         * a '@' is found, then report it as "snapshot".  Otherwise, remove the
         * snapshot attribute and try again.
         */
        if (types & ZFS_TYPE_SNAPSHOT) {
                if (strchr(path, '@') != NULL)
                        return (dgettext(TEXT_DOMAIN, "snapshot"));
                return (path_to_str(path, types & ~ZFS_TYPE_SNAPSHOT));
        }


        /*
         * The user has requested either filesystems or volumes.
         * We have no way of knowing a priori what type this would be, so always
         * report it as "filesystem" or "volume", our two primitive types.
         */
        if (types & ZFS_TYPE_FILESYSTEM)
                return (dgettext(TEXT_DOMAIN, "filesystem"));

        assert(types & ZFS_TYPE_VOLUME);
        return (dgettext(TEXT_DOMAIN, "volume"));
}

/*
 * Validate a ZFS path.  This is used even before trying to open the dataset, to
 * provide a more meaningful error message.  We place a more useful message in
 * 'buf' detailing exactly why the name was not valid.
 */
static int
zfs_validate_name(libzfs_handle_t *hdl, const char *path, int type,
    boolean_t modifying)
{
        namecheck_err_t why;
        char what;

        if (dataset_namecheck(path, &why, &what) != 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_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_INVALCHAR:
                                zfs_error_aux(hdl,
                                    dgettext(TEXT_DOMAIN, "invalid character "
                                    "'%c' in name"), what);
                                break;

                        case NAME_ERR_MULTIPLE_AT:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "multiple '@' delimiters in name"));
                                break;

                        case NAME_ERR_NOLETTER:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "pool doesn't 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,
                                    "reserved disk name"));
                                break;
                        }
                }

                return (0);
        }

        if (!(type & ZFS_TYPE_SNAPSHOT) && strchr(path, '@') != NULL) {
                if (hdl != NULL)
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "snapshot delimiter '@' in filesystem name"));
                return (0);
        }

        if (type == ZFS_TYPE_SNAPSHOT && strchr(path, '@') == NULL) {
                if (hdl != NULL)
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "missing '@' delimiter in snapshot name"));
                return (0);
        }

        if (modifying && strchr(path, '%') != NULL) {
                if (hdl != NULL)
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "invalid character %c in name"), '%');
                return (0);
        }

        return (-1);
}

int
zfs_name_valid(const char *name, zfs_type_t type)
{
        if (type == ZFS_TYPE_POOL)
                return (zpool_name_valid(NULL, B_FALSE, name));
        return (zfs_validate_name(NULL, name, type, B_FALSE));
}

/*
 * This function takes the raw DSL properties, and filters out the user-defined
 * properties into a separate nvlist.
 */
static nvlist_t *
process_user_props(zfs_handle_t *zhp, nvlist_t *props)
{
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        nvpair_t *elem;
        nvlist_t *propval;
        nvlist_t *nvl;

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

        elem = NULL;
        while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
                if (!zfs_prop_user(nvpair_name(elem)))
                        continue;

                verify(nvpair_value_nvlist(elem, &propval) == 0);
                if (nvlist_add_nvlist(nvl, nvpair_name(elem), propval) != 0) {
                        nvlist_free(nvl);
                        (void) no_memory(hdl);
                        return (NULL);
                }
        }

        return (nvl);
}

static zpool_handle_t *
zpool_add_handle(zfs_handle_t *zhp, const char *pool_name)
{
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        zpool_handle_t *zph;

        if ((zph = zpool_open_canfail(hdl, pool_name)) != NULL) {
                if (hdl->libzfs_pool_handles != NULL)
                        zph->zpool_next = hdl->libzfs_pool_handles;
                hdl->libzfs_pool_handles = zph;
        }
        return (zph);
}

static zpool_handle_t *
zpool_find_handle(zfs_handle_t *zhp, const char *pool_name, int len)
{
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        zpool_handle_t *zph = hdl->libzfs_pool_handles;

        while ((zph != NULL) &&
            (strncmp(pool_name, zpool_get_name(zph), len) != 0))
                zph = zph->zpool_next;
        return (zph);
}

/*
 * Returns a handle to the pool that contains the provided dataset.
 * If a handle to that pool already exists then that handle is returned.
 * Otherwise, a new handle is created and added to the list of handles.
 */
static zpool_handle_t *
zpool_handle(zfs_handle_t *zhp)
{
        char *pool_name;
        int len;
        zpool_handle_t *zph;

        len = strcspn(zhp->zfs_name, "/@") + 1;
        pool_name = zfs_alloc(zhp->zfs_hdl, len);
        (void) strlcpy(pool_name, zhp->zfs_name, len);

        zph = zpool_find_handle(zhp, pool_name, len);
        if (zph == NULL)
                zph = zpool_add_handle(zhp, pool_name);

        free(pool_name);
        return (zph);
}

void
zpool_free_handles(libzfs_handle_t *hdl)
{
        zpool_handle_t *next, *zph = hdl->libzfs_pool_handles;

        while (zph != NULL) {
                next = zph->zpool_next;
                zpool_close(zph);
                zph = next;
        }
        hdl->libzfs_pool_handles = NULL;
}

/*
 * Utility function to gather stats (objset and zpl) for the given object.
 */
static int
get_stats(zfs_handle_t *zhp)
{
        zfs_cmd_t zc = { 0 };
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        nvlist_t *allprops, *userprops;

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

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

        while (ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_OBJSET_STATS, &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);
                }
        }

        zhp->zfs_dmustats = zc.zc_objset_stats; /* structure assignment */

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

        zcmd_free_nvlists(&zc);

        if ((userprops = process_user_props(zhp, allprops)) == NULL) {
                nvlist_free(allprops);
                return (-1);
        }

        nvlist_free(zhp->zfs_props);
        nvlist_free(zhp->zfs_user_props);

        zhp->zfs_props = allprops;
        zhp->zfs_user_props = userprops;

        return (0);
}

/*
 * Refresh the properties currently stored in the handle.
 */
void
zfs_refresh_properties(zfs_handle_t *zhp)
{
        (void) get_stats(zhp);
}

/*
 * Makes a handle from the given dataset name.  Used by zfs_open() and
 * zfs_iter_* to create child handles on the fly.
 */
zfs_handle_t *
make_dataset_handle(libzfs_handle_t *hdl, const char *path)
{
        zfs_handle_t *zhp = calloc(sizeof (zfs_handle_t), 1);
        char *logstr;

        if (zhp == NULL)
                return (NULL);

        zhp->zfs_hdl = hdl;

        /*
         * Preserve history log string.
         * any changes performed here will be
         * logged as an internal event.
         */
        logstr = zhp->zfs_hdl->libzfs_log_str;
        zhp->zfs_hdl->libzfs_log_str = NULL;
top:
        (void) strlcpy(zhp->zfs_name, path, sizeof (zhp->zfs_name));

        if (get_stats(zhp) != 0) {
                zhp->zfs_hdl->libzfs_log_str = logstr;
                free(zhp);
                return (NULL);
        }

        if (zhp->zfs_dmustats.dds_inconsistent) {
                zfs_cmd_t zc = { 0 };

                /*
                 * If it is dds_inconsistent, then we've caught it in
                 * the middle of a 'zfs receive' or 'zfs destroy', and
                 * it is inconsistent from the ZPL's point of view, so
                 * can't be mounted.  However, it could also be that we
                 * have crashed in the middle of one of those
                 * operations, in which case we need to get rid of the
                 * inconsistent state.  We do that by either rolling
                 * back to the previous snapshot (which will fail if
                 * there is none), or destroying the filesystem.  Note
                 * that if we are still in the middle of an active
                 * 'receive' or 'destroy', then the rollback and destroy
                 * will fail with EBUSY and we will drive on as usual.
                 */

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

                if (zhp->zfs_dmustats.dds_type == DMU_OST_ZVOL) {
                        (void) zvol_remove_link(hdl, zhp->zfs_name);
                        zc.zc_objset_type = DMU_OST_ZVOL;
                } else {
                        zc.zc_objset_type = DMU_OST_ZFS;
                }

                /*
                 * If we can successfully destroy it, pretend that it
                 * never existed.
                 */
                if (ioctl(hdl->libzfs_fd, ZFS_IOC_DESTROY, &zc) == 0) {
                        zhp->zfs_hdl->libzfs_log_str = logstr;
                        free(zhp);
                        errno = ENOENT;
                        return (NULL);
                }
                /* If we can successfully roll it back, reget the stats */
                if (ioctl(hdl->libzfs_fd, ZFS_IOC_ROLLBACK, &zc) == 0)
                        goto top;
        }

        /*
         * We've managed to open the dataset and gather statistics.  Determine
         * the high-level type.
         */
        if (zhp->zfs_dmustats.dds_type == DMU_OST_ZVOL)
                zhp->zfs_head_type = ZFS_TYPE_VOLUME;
        else if (zhp->zfs_dmustats.dds_type == DMU_OST_ZFS)
                zhp->zfs_head_type = ZFS_TYPE_FILESYSTEM;
        else
                abort();

        if (zhp->zfs_dmustats.dds_is_snapshot)
                zhp->zfs_type = ZFS_TYPE_SNAPSHOT;
        else if (zhp->zfs_dmustats.dds_type == DMU_OST_ZVOL)
                zhp->zfs_type = ZFS_TYPE_VOLUME;
        else if (zhp->zfs_dmustats.dds_type == DMU_OST_ZFS)
                zhp->zfs_type = ZFS_TYPE_FILESYSTEM;
        else
                abort();        /* we should never see any other types */

        zhp->zfs_hdl->libzfs_log_str = logstr;
        zhp->zpool_hdl = zpool_handle(zhp);
        return (zhp);
}

/*
 * Opens the given snapshot, filesystem, or volume.   The 'types'
 * argument is a mask of acceptable types.  The function will print an
 * appropriate error message and return NULL if it can't be opened.
 */
zfs_handle_t *
zfs_open(libzfs_handle_t *hdl, const char *path, int types)
{
        zfs_handle_t *zhp;
        char errbuf[1024];

        (void) snprintf(errbuf, sizeof (errbuf),
            dgettext(TEXT_DOMAIN, "cannot open '%s'"), path);

        /*
         * Validate the name before we even try to open it.
         */
        if (!zfs_validate_name(hdl, path, ZFS_TYPE_DATASET, B_FALSE)) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "invalid dataset name"));
                (void) zfs_error(hdl, EZFS_INVALIDNAME, errbuf);
                return (NULL);
        }

        /*
         * Try to get stats for the dataset, which will tell us if it exists.
         */
        errno = 0;
        if ((zhp = make_dataset_handle(hdl, path)) == NULL) {
                (void) zfs_standard_error(hdl, errno, errbuf);
                return (NULL);
        }

        if (!(types & zhp->zfs_type)) {
                (void) zfs_error(hdl, EZFS_BADTYPE, errbuf);
                zfs_close(zhp);
                return (NULL);
        }

        return (zhp);
}

/*
 * Release a ZFS handle.  Nothing to do but free the associated memory.
 */
void
zfs_close(zfs_handle_t *zhp)
{
        if (zhp->zfs_mntopts)
                free(zhp->zfs_mntopts);
        nvlist_free(zhp->zfs_props);
        nvlist_free(zhp->zfs_user_props);
        free(zhp);
}

int
zfs_spa_version(zfs_handle_t *zhp, int *spa_version)
{
        zpool_handle_t *zpool_handle = zhp->zpool_hdl;

        if (zpool_handle == NULL)
                return (-1);

        *spa_version = zpool_get_prop_int(zpool_handle,
            ZPOOL_PROP_VERSION, NULL);
        return (0);
}

/*
 * The choice of reservation property depends on the SPA version.
 */
static int
zfs_which_resv_prop(zfs_handle_t *zhp, zfs_prop_t *resv_prop)
{
        int spa_version;

        if (zfs_spa_version(zhp, &spa_version) < 0)
                return (-1);

        if (spa_version >= SPA_VERSION_REFRESERVATION)
                *resv_prop = ZFS_PROP_REFRESERVATION;
        else
                *resv_prop = ZFS_PROP_RESERVATION;

        return (0);
}

/*
 * Given an nvlist of properties to set, validates that they are correct, and
 * parses any numeric properties (index, boolean, etc) if they are specified as
 * strings.
 */
nvlist_t *
zfs_valid_proplist(libzfs_handle_t *hdl, zfs_type_t type, nvlist_t *nvl,
    uint64_t zoned, zfs_handle_t *zhp, const char *errbuf)
{
        nvpair_t *elem;
        uint64_t intval;
        char *strval;
        zfs_prop_t prop;
        nvlist_t *ret;
        int chosen_normal = -1;
        int chosen_utf = -1;

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

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

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

                        /*
                         * If this is a user property, make sure it's a
                         * string, and that it's less than ZAP_MAXNAMELEN.
                         */
                        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;
                        }

                        if (strlen(nvpair_name(elem)) >= ZAP_MAXNAMELEN) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property name '%s' is too long"),
                                    propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        (void) nvpair_value_string(elem, &strval);
                        if (nvlist_add_string(ret, propname, strval) != 0) {
                                (void) no_memory(hdl);
                                goto error;
                        }
                        continue;
                }

                if (type == ZFS_TYPE_SNAPSHOT) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "this property can not be modified for snapshots"));
                        (void) zfs_error(hdl, EZFS_PROPTYPE, errbuf);
                        goto error;
                }

                if (!zfs_prop_valid_for_type(prop, type)) {
                        zfs_error_aux(hdl,
                            dgettext(TEXT_DOMAIN, "'%s' does not "
                            "apply to datasets of this type"), propname);
                        (void) zfs_error(hdl, EZFS_PROPTYPE, errbuf);
                        goto error;
                }

                if (zfs_prop_readonly(prop) &&
                    (!zfs_prop_setonce(prop) || zhp != NULL)) {
                        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, type, ret,
                    &strval, &intval, errbuf) != 0)
                        goto error;

                /*
                 * Perform some additional checks for specific properties.
                 */
                switch (prop) {
                case ZFS_PROP_VERSION:
                {
                        int version;

                        if (zhp == NULL)
                                break;
                        version = zfs_prop_get_int(zhp, ZFS_PROP_VERSION);
                        if (intval < version) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "Can not downgrade; already at version %u"),
                                    version);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }
                        break;
                }

                case ZFS_PROP_RECORDSIZE:
                case ZFS_PROP_VOLBLOCKSIZE:
                        /* must be power of two within SPA_{MIN,MAX}BLOCKSIZE */
                        if (intval < SPA_MINBLOCKSIZE ||
                            intval > SPA_MAXBLOCKSIZE || !ISP2(intval)) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "'%s' must be power of 2 from %u "
                                    "to %uk"), propname,
                                    (uint_t)SPA_MINBLOCKSIZE,
                                    (uint_t)SPA_MAXBLOCKSIZE >> 10);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }
                        break;

                case ZFS_PROP_SHAREISCSI:
                        if (strcmp(strval, "off") != 0 &&
                            strcmp(strval, "on") != 0 &&
                            strcmp(strval, "type=disk") != 0) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "'%s' must be 'on', 'off', or 'type=disk'"),
                                    propname);
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }

                        break;

                case ZFS_PROP_MOUNTPOINT:
                {
                        namecheck_err_t why;

                        if (strcmp(strval, ZFS_MOUNTPOINT_NONE) == 0 ||
                            strcmp(strval, ZFS_MOUNTPOINT_LEGACY) == 0)
                                break;

                        if (mountpoint_namecheck(strval, &why)) {
                                switch (why) {
                                case NAME_ERR_LEADING_SLASH:
                                        zfs_error_aux(hdl,
                                            dgettext(TEXT_DOMAIN,
                                            "'%s' must be an absolute path, "
                                            "'none', or 'legacy'"), propname);
                                        break;
                                case NAME_ERR_TOOLONG:
                                        zfs_error_aux(hdl,
                                            dgettext(TEXT_DOMAIN,
                                            "component of '%s' is too long"),
                                            propname);
                                        break;
                                }
                                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                                goto error;
                        }
                }

                        /*FALLTHRU*/

                case ZFS_PROP_SHARESMB:
                case ZFS_PROP_SHARENFS:
                        /*
                         * For the mountpoint and sharenfs or sharesmb
                         * properties, check if it can be set in a
                         * global/non-global zone based on
                         * the zoned property value:
                         *
                         *              global zone         non-global zone
                         * --------------------------------------------------
                         * zoned=on     mountpoint (no)     mountpoint (yes)
                         *              sharenfs (no)       sharenfs (no)
                         *              sharesmb (no)       sharesmb (no)
                         *
                         * zoned=off    mountpoint (yes)        N/A
                         *              sharenfs (yes)
                         *              sharesmb (yes)
                         */
                        if (zoned) {
                                if (getzoneid() == GLOBAL_ZONEID) {
                                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                            "'%s' cannot be set on "
                                            "dataset in a non-global zone"),
                                            propname);
                                        (void) zfs_error(hdl, EZFS_ZONED,
                                            errbuf);
                                        goto error;
                                } else if (prop == ZFS_PROP_SHARENFS ||
                                    prop == ZFS_PROP_SHARESMB) {
                                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                            "'%s' cannot be set in "
                                            "a non-global zone"), propname);
                                        (void) zfs_error(hdl, EZFS_ZONED,
                                            errbuf);
                                        goto error;
                                }
                        } else if (getzoneid() != GLOBAL_ZONEID) {
                                /*
                                 * If zoned property is 'off', this must be in
                                 * a globle zone. If not, something is wrong.
                                 */
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "'%s' cannot be set while dataset "
                                    "'zoned' property is set"), propname);
                                (void) zfs_error(hdl, EZFS_ZONED, errbuf);
                                goto error;
                        }

                        /*
                         * At this point, it is legitimate to set the
                         * property. Now we want to make sure that the
                         * property value is valid if it is sharenfs.
                         */
                        if ((prop == ZFS_PROP_SHARENFS ||
                            prop == ZFS_PROP_SHARESMB) &&
                            strcmp(strval, "on") != 0 &&
                            strcmp(strval, "off") != 0) {
                                zfs_share_proto_t proto;

                                if (prop == ZFS_PROP_SHARESMB)
                                        proto = PROTO_SMB;
                                else
                                        proto = PROTO_NFS;

                                /*
                                 * Must be an valid sharing protocol
                                 * option string so init the libshare
                                 * in order to enable the parser and
                                 * then parse the options. We use the
                                 * control API since we don't care about
                                 * the current configuration and don't
                                 * want the overhead of loading it
                                 * until we actually do something.
                                 */

                                if (zfs_init_libshare(hdl,
                                    SA_INIT_CONTROL_API) != SA_OK) {
                                        /*
                                         * An error occurred so we can't do
                                         * anything
                                         */
                                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                            "'%s' cannot be set: problem "
                                            "in share initialization"),
                                            propname);
                                        (void) zfs_error(hdl, EZFS_BADPROP,
                                            errbuf);
                                        goto error;
                                }

                                if (zfs_parse_options(strval, proto) != SA_OK) {
                                        /*
                                         * There was an error in parsing so
                                         * deal with it by issuing an error
                                         * message and leaving after
                                         * uninitializing the the libshare
                                         * interface.
                                         */
                                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                            "'%s' cannot be set to invalid "
                                            "options"), propname);
                                        (void) zfs_error(hdl, EZFS_BADPROP,
                                            errbuf);
                                        zfs_uninit_libshare(hdl);
                                        goto error;
                                }
                                zfs_uninit_libshare(hdl);
                        }

                        break;
                case ZFS_PROP_UTF8ONLY:
                        chosen_utf = (int)intval;
                        break;
                case ZFS_PROP_NORMALIZE:
                        chosen_normal = (int)intval;
                        break;
                }

                /*
                 * For changes to existing volumes, we have some additional
                 * checks to enforce.
                 */
                if (type == ZFS_TYPE_VOLUME && zhp != NULL) {
                        uint64_t volsize = zfs_prop_get_int(zhp,
                            ZFS_PROP_VOLSIZE);
                        uint64_t blocksize = zfs_prop_get_int(zhp,
                            ZFS_PROP_VOLBLOCKSIZE);
                        char buf[64];

                        switch (prop) {
                        case ZFS_PROP_RESERVATION:
                        case ZFS_PROP_REFRESERVATION:
                                if (intval > volsize) {
                                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                            "'%s' is greater than current "
                                            "volume size"), propname);
                                        (void) zfs_error(hdl, EZFS_BADPROP,
                                            errbuf);
                                        goto error;
                                }
                                break;

                        case ZFS_PROP_VOLSIZE:
                                if (intval % blocksize != 0) {
                                        zfs_nicenum(blocksize, buf,
                                            sizeof (buf));
                                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                            "'%s' must be a multiple of "
                                            "volume block size (%s)"),
                                            propname, buf);
                                        (void) zfs_error(hdl, EZFS_BADPROP,
                                            errbuf);
                                        goto error;
                                }

                                if (intval == 0) {
                                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                            "'%s' cannot be zero"),
                                            propname);
                                        (void) zfs_error(hdl, EZFS_BADPROP,
                                            errbuf);
                                        goto error;
                                }
                                break;
                        }
                }
        }

        /*
         * If normalization was chosen, but no UTF8 choice was made,
         * enforce rejection of non-UTF8 names.
         *
         * If normalization was chosen, but rejecting non-UTF8 names
         * was explicitly not chosen, it is an error.
         */
        if (chosen_normal > 0 && chosen_utf < 0) {
                if (nvlist_add_uint64(ret,
                    zfs_prop_to_name(ZFS_PROP_UTF8ONLY), 1) != 0) {
                        (void) no_memory(hdl);
                        goto error;
                }
        } else if (chosen_normal > 0 && chosen_utf == 0) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "'%s' must be set 'on' if normalization chosen"),
                    zfs_prop_to_name(ZFS_PROP_UTF8ONLY));
                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                goto error;
        }

        /*
         * If this is an existing volume, and someone is setting the volsize,
         * make sure that it matches the reservation, or add it if necessary.
         */
        if (zhp != NULL && type == ZFS_TYPE_VOLUME &&
            nvlist_lookup_uint64(ret, zfs_prop_to_name(ZFS_PROP_VOLSIZE),
            &intval) == 0) {
                uint64_t old_volsize = zfs_prop_get_int(zhp,
                    ZFS_PROP_VOLSIZE);
                uint64_t old_reservation;
                uint64_t new_reservation;
                zfs_prop_t resv_prop;

                if (zfs_which_resv_prop(zhp, &resv_prop) < 0)
                        goto error;
                old_reservation = zfs_prop_get_int(zhp, resv_prop);

                if (old_volsize == old_reservation &&
                    nvlist_lookup_uint64(ret, zfs_prop_to_name(resv_prop),
                    &new_reservation) != 0) {
                        if (nvlist_add_uint64(ret,
                            zfs_prop_to_name(resv_prop), intval) != 0) {
                                (void) no_memory(hdl);
                                goto error;
                        }
                }
        }
        return (ret);

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

static int
zfs_get_perm_who(const char *who, zfs_deleg_who_type_t *who_type,
    uint64_t *ret_who)
{
        struct passwd *pwd;
        struct group *grp;
        uid_t id;

        if (*who_type == ZFS_DELEG_EVERYONE || *who_type == ZFS_DELEG_CREATE ||
            *who_type == ZFS_DELEG_NAMED_SET) {
                *ret_who = -1;
                return (0);
        }
        if (who == NULL && !(*who_type == ZFS_DELEG_EVERYONE))
                return (EZFS_BADWHO);

        if (*who_type == ZFS_DELEG_WHO_UNKNOWN &&
            strcmp(who, "everyone") == 0) {
                *ret_who = -1;
                *who_type = ZFS_DELEG_EVERYONE;
                return (0);
        }

        pwd = getpwnam(who);
        grp = getgrnam(who);

        if ((*who_type == ZFS_DELEG_USER) && pwd) {
                *ret_who = pwd->pw_uid;
        } else if ((*who_type == ZFS_DELEG_GROUP) && grp) {
                *ret_who = grp->gr_gid;
        } else if (pwd) {
                *ret_who = pwd->pw_uid;
                *who_type = ZFS_DELEG_USER;
        } else if (grp) {
                *ret_who = grp->gr_gid;
                *who_type = ZFS_DELEG_GROUP;
        } else {
                char *end;

                id = strtol(who, &end, 10);
                if (errno != 0 || *end != '\0') {
                        return (EZFS_BADWHO);
                } else {
                        *ret_who = id;
                        if (*who_type == ZFS_DELEG_WHO_UNKNOWN)
                                *who_type = ZFS_DELEG_USER;
                }
        }

        return (0);
}

static void
zfs_perms_add_to_nvlist(nvlist_t *who_nvp, char *name, nvlist_t *perms_nvp)
{
        if (perms_nvp != NULL) {
                verify(nvlist_add_nvlist(who_nvp,
                    name, perms_nvp) == 0);
        } else {
                verify(nvlist_add_boolean(who_nvp, name) == 0);
        }
}

static void
helper(zfs_deleg_who_type_t who_type, uint64_t whoid, char *whostr,
    zfs_deleg_inherit_t inherit, nvlist_t *who_nvp, nvlist_t *perms_nvp,
    nvlist_t *sets_nvp)
{
        boolean_t do_perms, do_sets;
        char name[ZFS_MAX_DELEG_NAME];

        do_perms = (nvlist_next_nvpair(perms_nvp, NULL) != NULL);
        do_sets = (nvlist_next_nvpair(sets_nvp, NULL) != NULL);

        if (!do_perms && !do_sets)
                do_perms = do_sets = B_TRUE;

        if (do_perms) {
                zfs_deleg_whokey(name, who_type, inherit,
                    (who_type == ZFS_DELEG_NAMED_SET) ?
                    whostr : (void *)&whoid);
                zfs_perms_add_to_nvlist(who_nvp, name, perms_nvp);
        }
        if (do_sets) {
                zfs_deleg_whokey(name, toupper(who_type), inherit,
                    (who_type == ZFS_DELEG_NAMED_SET) ?
                    whostr : (void *)&whoid);
                zfs_perms_add_to_nvlist(who_nvp, name, sets_nvp);
        }
}

static void
zfs_perms_add_who_nvlist(nvlist_t *who_nvp, uint64_t whoid, void *whostr,
    nvlist_t *perms_nvp, nvlist_t *sets_nvp,
    zfs_deleg_who_type_t who_type, zfs_deleg_inherit_t inherit)
{
        if (who_type == ZFS_DELEG_NAMED_SET || who_type == ZFS_DELEG_CREATE) {
                helper(who_type, whoid, whostr, 0,
                    who_nvp, perms_nvp, sets_nvp);
        } else {
                if (inherit & ZFS_DELEG_PERM_LOCAL) {
                        helper(who_type, whoid, whostr, ZFS_DELEG_LOCAL,
                            who_nvp, perms_nvp, sets_nvp);
                }
                if (inherit & ZFS_DELEG_PERM_DESCENDENT) {
                        helper(who_type, whoid, whostr, ZFS_DELEG_DESCENDENT,
                            who_nvp, perms_nvp, sets_nvp);
                }
        }
}

/*
 * Construct nvlist to pass down to kernel for setting/removing permissions.
 *
 * The nvlist is constructed as a series of nvpairs with an optional embedded
 * nvlist of permissions to remove or set.  The topmost nvpairs are the actual
 * base attribute named stored in the dsl.
 * Arguments:
 *
 * whostr:   is a comma separated list of users, groups, or a single set name.
 *           whostr may be null for everyone or create perms.
 * who_type: is the type of entry in whostr.  Typically this will be
 *           ZFS_DELEG_WHO_UNKNOWN.
 * perms:    common separated list of permissions.  May be null if user
 *           is requested to remove permissions by who.
 * inherit:  Specifies the inheritance of the permissions.  Will be either
 *           ZFS_DELEG_PERM_LOCAL and/or  ZFS_DELEG_PERM_DESCENDENT.
 * nvp       The constructed nvlist to pass to zfs_perm_set().
 *           The output nvp will look something like this.
 *              ul$1234 -> {create ; destroy }
 *              Ul$1234 -> { @myset }
 *              s-$@myset - { snapshot; checksum; compression }
 */
int
zfs_build_perms(zfs_handle_t *zhp, char *whostr, char *perms,
    zfs_deleg_who_type_t who_type, zfs_deleg_inherit_t inherit, nvlist_t **nvp)
{
        nvlist_t *who_nvp;
        nvlist_t *perms_nvp = NULL;
        nvlist_t *sets_nvp = NULL;
        char errbuf[1024];
        char *who_tok, *perm;
        int error;

        *nvp = NULL;

        if (perms) {
                if ((error = nvlist_alloc(&perms_nvp,
                    NV_UNIQUE_NAME, 0)) != 0) {
                        return (1);
                }
                if ((error = nvlist_alloc(&sets_nvp,
                    NV_UNIQUE_NAME, 0)) != 0) {
                        nvlist_free(perms_nvp);
                        return (1);
                }
        }

        if ((error = nvlist_alloc(&who_nvp, NV_UNIQUE_NAME, 0)) != 0) {
                if (perms_nvp)
                        nvlist_free(perms_nvp);
                if (sets_nvp)
                        nvlist_free(sets_nvp);
                return (1);
        }

        if (who_type == ZFS_DELEG_NAMED_SET) {
                namecheck_err_t why;
                char what;

                if ((error = permset_namecheck(whostr, &why, &what)) != 0) {
                        nvlist_free(who_nvp);
                        if (perms_nvp)
                                nvlist_free(perms_nvp);
                        if (sets_nvp)
                                nvlist_free(sets_nvp);

                        switch (why) {
                        case NAME_ERR_NO_AT:
                                zfs_error_aux(zhp->zfs_hdl,
                                    dgettext(TEXT_DOMAIN,
                                    "set definition must begin with an '@' "
                                    "character"));
                        }
                        return (zfs_error(zhp->zfs_hdl,
                            EZFS_BADPERMSET, whostr));
                }
        }

        /*
         * Build up nvlist(s) of permissions.  Two nvlists are maintained.
         * The first nvlist perms_nvp will have normal permissions and the
         * other sets_nvp will have only permssion set names in it.
         */
        for (perm = strtok(perms, ","); perm; perm = strtok(NULL, ",")) {
                const char *perm_canonical = zfs_deleg_canonicalize_perm(perm);

                if (perm_canonical) {
                        verify(nvlist_add_boolean(perms_nvp,
                            perm_canonical) == 0);
                } else if (perm[0] == '@') {
                        verify(nvlist_add_boolean(sets_nvp, perm) == 0);
                } else {
                        nvlist_free(who_nvp);
                        nvlist_free(perms_nvp);
                        nvlist_free(sets_nvp);
                        return (zfs_error(zhp->zfs_hdl, EZFS_BADPERM, perm));
                }
        }

        if (whostr && who_type != ZFS_DELEG_CREATE) {
                who_tok = strtok(whostr, ",");
                if (who_tok == NULL) {
                        nvlist_free(who_nvp);
                        if (perms_nvp)
                                nvlist_free(perms_nvp);
                        if (sets_nvp)
                                nvlist_free(sets_nvp);
                        (void) snprintf(errbuf, sizeof (errbuf),
                            dgettext(TEXT_DOMAIN, "Who string is NULL"),
                            whostr);
                        return (zfs_error(zhp->zfs_hdl, EZFS_BADWHO, errbuf));
                }
        }

        /*
         * Now create the nvlist(s)
         */
        do {
                uint64_t who_id;

                error = zfs_get_perm_who(who_tok, &who_type,
                    &who_id);
                if (error) {
                        nvlist_free(who_nvp);
                        if (perms_nvp)
                                nvlist_free(perms_nvp);
                        if (sets_nvp)
                                nvlist_free(sets_nvp);
                        (void) snprintf(errbuf, sizeof (errbuf),
                            dgettext(TEXT_DOMAIN,
                            "Unable to determine uid/gid for "
                            "%s "), who_tok);
                        return (zfs_error(zhp->zfs_hdl, EZFS_BADWHO, errbuf));
                }

                /*
                 * add entries for both local and descendent when required
                 */
                zfs_perms_add_who_nvlist(who_nvp, who_id, who_tok,
                    perms_nvp, sets_nvp, who_type, inherit);

        } while (who_tok = strtok(NULL, ","));
        *nvp = who_nvp;
        return (0);
}

static int
zfs_perm_set_common(zfs_handle_t *zhp, nvlist_t *nvp, boolean_t unset)
{
        zfs_cmd_t zc = { 0 };
        int error;
        char errbuf[1024];

        (void) snprintf(errbuf, sizeof (errbuf),
            dgettext(TEXT_DOMAIN, "Cannot update 'allows' for '%s'"),
            zhp->zfs_name);

        if (zcmd_write_src_nvlist(zhp->zfs_hdl, &zc, nvp))
                return (-1);

        (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
        zc.zc_perm_action = unset;

        error = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_SET_FSACL, &zc);
        if (error && errno == ENOTSUP) {
                (void) snprintf(errbuf, sizeof (errbuf),
                    gettext("Pool must be upgraded to use 'allow/unallow'"));
                zcmd_free_nvlists(&zc);
                return (zfs_error(zhp->zfs_hdl, EZFS_BADVERSION, errbuf));
        } else if (error) {
                return (zfs_standard_error(zhp->zfs_hdl, errno, errbuf));
        }
        zcmd_free_nvlists(&zc);

        return (error);
}

int
zfs_perm_set(zfs_handle_t *zhp, nvlist_t *nvp)
{
        return (zfs_perm_set_common(zhp, nvp, B_FALSE));
}

int
zfs_perm_remove(zfs_handle_t *zhp, nvlist_t *perms)
{
        return (zfs_perm_set_common(zhp, perms, B_TRUE));
}

static int
perm_compare(const void *arg1, const void *arg2)
{
        const zfs_perm_node_t *node1 = arg1;
        const zfs_perm_node_t *node2 = arg2;
        int ret;

        ret = strcmp(node1->z_pname, node2->z_pname);

        if (ret > 0)
                return (1);
        if (ret < 0)
                return (-1);
        else
                return (0);
}

static void
zfs_destroy_perm_tree(avl_tree_t *tree)
{
        zfs_perm_node_t *permnode;
        void *cookie = NULL;

        while ((permnode = avl_destroy_nodes(tree,  &cookie)) != NULL)
                free(permnode);
        avl_destroy(tree);
}

static void
zfs_destroy_tree(avl_tree_t *tree)
{
        zfs_allow_node_t *allownode;
        void *cookie = NULL;

        while ((allownode = avl_destroy_nodes(tree, &cookie)) != NULL) {
                zfs_destroy_perm_tree(&allownode->z_localdescend);
                zfs_destroy_perm_tree(&allownode->z_local);
                zfs_destroy_perm_tree(&allownode->z_descend);
                free(allownode);
        }
        avl_destroy(tree);
}

void
zfs_free_allows(zfs_allow_t *allow)
{
        zfs_allow_t *allownext;
        zfs_allow_t *freeallow;

        allownext = allow;
        while (allownext) {
                zfs_destroy_tree(&allownext->z_sets);
                zfs_destroy_tree(&allownext->z_crperms);
                zfs_destroy_tree(&allownext->z_user);
                zfs_destroy_tree(&allownext->z_group);
                zfs_destroy_tree(&allownext->z_everyone);
                freeallow = allownext;
                allownext = allownext->z_next;
                free(freeallow);
        }
}

static zfs_allow_t *
zfs_alloc_perm_tree(zfs_handle_t *zhp, zfs_allow_t *prev, char *setpoint)
{
        zfs_allow_t *ptree;

        if ((ptree = zfs_alloc(zhp->zfs_hdl,
            sizeof (zfs_allow_t))) == NULL) {
                return (NULL);
        }

        (void) strlcpy(ptree->z_setpoint, setpoint, sizeof (ptree->z_setpoint));
        avl_create(&ptree->z_sets,
            perm_compare, sizeof (zfs_allow_node_t),
            offsetof(zfs_allow_node_t, z_node));
        avl_create(&ptree->z_crperms,
            perm_compare, sizeof (zfs_allow_node_t),
            offsetof(zfs_allow_node_t, z_node));
        avl_create(&ptree->z_user,
            perm_compare, sizeof (zfs_allow_node_t),
            offsetof(zfs_allow_node_t, z_node));
        avl_create(&ptree->z_group,
            perm_compare, sizeof (zfs_allow_node_t),
            offsetof(zfs_allow_node_t, z_node));
        avl_create(&ptree->z_everyone,
            perm_compare, sizeof (zfs_allow_node_t),
            offsetof(zfs_allow_node_t, z_node));

        if (prev)
                prev->z_next = ptree;
        ptree->z_next = NULL;
        return (ptree);
}

/*
 * Add permissions to the appropriate AVL permission tree.
 * The appropriate tree may not be the requested tree.
 * For example if ld indicates a local permission, but
 * same permission also exists as a descendent permission
 * then the permission will be removed from the descendent
 * tree and add the the local+descendent tree.
 */
static int
zfs_coalesce_perm(zfs_handle_t *zhp, zfs_allow_node_t *allownode,
    char *perm, char ld)
{
        zfs_perm_node_t pnode, *permnode, *permnode2;
        zfs_perm_node_t *newnode;
        avl_index_t where, where2;
        avl_tree_t *tree, *altree;

        (void) strlcpy(pnode.z_pname, perm, sizeof (pnode.z_pname));

        if (ld == ZFS_DELEG_NA) {
                tree =  &allownode->z_localdescend;
                altree = &allownode->z_descend;
        } else if (ld == ZFS_DELEG_LOCAL) {
                tree = &allownode->z_local;
                altree = &allownode->z_descend;
        } else {
                tree = &allownode->z_descend;
                altree = &allownode->z_local;
        }
        permnode = avl_find(tree, &pnode, &where);
        permnode2 = avl_find(altree, &pnode, &where2);

        if (permnode2) {
                avl_remove(altree, permnode2);
                free(permnode2);
                if (permnode == NULL) {
                        tree =  &allownode->z_localdescend;
                }
        }

        /*
         * Now insert new permission in either requested location
         * local/descendent or into ld when perm will exist in both.
         */
        if (permnode == NULL) {
                if ((newnode = zfs_alloc(zhp->zfs_hdl,
                    sizeof (zfs_perm_node_t))) == NULL) {
                        return (-1);
                }
                *newnode = pnode;
                avl_add(tree, newnode);
        }
        return (0);
}

/*
 * Uggh, this is going to be a bit complicated.
 * we have an nvlist coming out of the kernel that
 * will indicate where the permission is set and then
 * it will contain allow of the various "who's", and what
 * their permissions are.  To further complicate this
 * we will then have to coalesce the local,descendent
 * and local+descendent permissions where appropriate.
 * The kernel only knows about a permission as being local
 * or descendent, but not both.
 *
 * In order to make this easier for zfs_main to deal with
 * a series of AVL trees will be used to maintain
 * all of this, primarily for sorting purposes as well
 * as the ability to quickly locate a specific entry.
 *
 * What we end up with are tree's for sets, create perms,
 * user, groups and everyone.  With each of those trees
 * we have subtrees for local, descendent and local+descendent
 * permissions.
 */
int
zfs_perm_get(zfs_handle_t *zhp, zfs_allow_t **zfs_perms)
{
        zfs_cmd_t zc = { 0 };
        int error;
        nvlist_t *nvlist;
        nvlist_t *permnv, *sourcenv;
        nvpair_t *who_pair, *source_pair;
        nvpair_t *perm_pair;
        char errbuf[1024];
        zfs_allow_t *zallowp, *newallowp;
        char  ld;
        char *nvpname;
        uid_t   uid;
        gid_t   gid;
        avl_tree_t *tree;
        avl_index_t where;

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

        if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
                return (-1);

        while (ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_GET_FSACL, &zc) != 0) {
                if (errno == ENOMEM) {
                        if (zcmd_expand_dst_nvlist(zhp->zfs_hdl, &zc) != 0) {
                                zcmd_free_nvlists(&zc);
                                return (-1);
                        }
                } else if (errno == ENOTSUP) {
                        zcmd_free_nvlists(&zc);
                        (void) snprintf(errbuf, sizeof (errbuf),
                            gettext("Pool must be upgraded to use 'allow'"));
                        return (zfs_error(zhp->zfs_hdl,
                            EZFS_BADVERSION, errbuf));
                } else {
                        zcmd_free_nvlists(&zc);
                        return (-1);
                }
        }

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

        zcmd_free_nvlists(&zc);

        source_pair = nvlist_next_nvpair(nvlist, NULL);

        if (source_pair == NULL) {
                *zfs_perms = NULL;
                return (0);
        }

        *zfs_perms = zfs_alloc_perm_tree(zhp, NULL, nvpair_name(source_pair));
        if (*zfs_perms == NULL) {
                return (0);
        }

        zallowp = *zfs_perms;

        for (;;) {
                struct passwd *pwd;
                struct group *grp;
                zfs_allow_node_t *allownode;
                zfs_allow_node_t  findallownode;
                zfs_allow_node_t *newallownode;

                (void) strlcpy(zallowp->z_setpoint,
                    nvpair_name(source_pair),
                    sizeof (zallowp->z_setpoint));

                if ((error = nvpair_value_nvlist(source_pair, &sourcenv)) != 0)
                        goto abort;

                /*
                 * Make sure nvlist is composed correctly
                 */
                if (zfs_deleg_verify_nvlist(sourcenv)) {
                        goto abort;
                }

                who_pair = nvlist_next_nvpair(sourcenv, NULL);
                if (who_pair == NULL) {
                        goto abort;
                }

                do {
                        error = nvpair_value_nvlist(who_pair, &permnv);
                        if (error) {
                                goto abort;
                        }

                        /*
                         * First build up the key to use
                         * for looking up in the various
                         * who trees.
                         */
                        ld = nvpair_name(who_pair)[1];
                        nvpname = nvpair_name(who_pair);
                        switch (nvpair_name(who_pair)[0]) {
                        case ZFS_DELEG_USER:
                        case ZFS_DELEG_USER_SETS:
                                tree = &zallowp->z_user;
                                uid = atol(&nvpname[3]);
                                pwd = getpwuid(uid);
                                (void) snprintf(findallownode.z_key,
                                    sizeof (findallownode.z_key), "user %s",
                                    (pwd) ? pwd->pw_name :
                                    &nvpair_name(who_pair)[3]);
                                break;
                        case ZFS_DELEG_GROUP:
                        case ZFS_DELEG_GROUP_SETS:
                                tree = &zallowp->z_group;
                                gid = atol(&nvpname[3]);
                                grp = getgrgid(gid);
                                (void) snprintf(findallownode.z_key,
                                    sizeof (findallownode.z_key), "group %s",
                                    (grp) ? grp->gr_name :
                                    &nvpair_name(who_pair)[3]);
                                break;
                        case ZFS_DELEG_CREATE:
                        case ZFS_DELEG_CREATE_SETS:
                                tree = &zallowp->z_crperms;
                                (void) strlcpy(findallownode.z_key, "",
                                    sizeof (findallownode.z_key));
                                break;
                        case ZFS_DELEG_EVERYONE:
                        case ZFS_DELEG_EVERYONE_SETS:
                                (void) snprintf(findallownode.z_key,
                                    sizeof (findallownode.z_key), "everyone");
                                tree = &zallowp->z_everyone;
                                break;
                        case ZFS_DELEG_NAMED_SET:
                        case ZFS_DELEG_NAMED_SET_SETS:
                                (void) snprintf(findallownode.z_key,
                                    sizeof (findallownode.z_key), "%s",
                                    &nvpair_name(who_pair)[3]);
                                tree = &zallowp->z_sets;
                                break;
                        }

                        /*
                         * Place who in tree
                         */
                        allownode = avl_find(tree, &findallownode, &where);
                        if (allownode == NULL) {
                                if ((newallownode = zfs_alloc(zhp->zfs_hdl,
                                    sizeof (zfs_allow_node_t))) == NULL) {
                                        goto abort;
                                }
                                avl_create(&newallownode->z_localdescend,
                                    perm_compare,
                                    sizeof (zfs_perm_node_t),
                                    offsetof(zfs_perm_node_t, z_node));
                                avl_create(&newallownode->z_local,
                                    perm_compare,
                                    sizeof (zfs_perm_node_t),
                                    offsetof(zfs_perm_node_t, z_node));
                                avl_create(&newallownode->z_descend,
                                    perm_compare,
                                    sizeof (zfs_perm_node_t),
                                    offsetof(zfs_perm_node_t, z_node));
                                (void) strlcpy(newallownode->z_key,
                                    findallownode.z_key,
                                    sizeof (findallownode.z_key));
                                avl_insert(tree, newallownode, where);
                                allownode = newallownode;
                        }

                        /*
                         * Now iterate over the permissions and
                         * place them in the appropriate local,
                         * descendent or local+descendent tree.
                         *
                         * The permissions are added to the tree
                         * via zfs_coalesce_perm().
                         */
                        perm_pair = nvlist_next_nvpair(permnv, NULL);
                        if (perm_pair == NULL)
                                goto abort;
                        do {
                                if (zfs_coalesce_perm(zhp, allownode,
                                    nvpair_name(perm_pair), ld) != 0)
                                        goto abort;
                        } while (perm_pair = nvlist_next_nvpair(permnv,
                            perm_pair));
                } while (who_pair = nvlist_next_nvpair(sourcenv, who_pair));

                source_pair = nvlist_next_nvpair(nvlist, source_pair);
                if (source_pair == NULL)
                        break;

                /*
                 * allocate another node from the link list of
                 * zfs_allow_t structures
                 */
                newallowp = zfs_alloc_perm_tree(zhp, zallowp,
                    nvpair_name(source_pair));
                if (newallowp == NULL) {
                        goto abort;
                }
                zallowp = newallowp;
        }
        nvlist_free(nvlist);
        return (0);
abort:
        zfs_free_allows(*zfs_perms);
        nvlist_free(nvlist);
        return (-1);
}

static char *
zfs_deleg_perm_note(zfs_deleg_note_t note)
{
        /*
         * Don't put newlines on end of lines
         */
        switch (note) {
        case ZFS_DELEG_NOTE_CREATE:
                return (dgettext(TEXT_DOMAIN,
                    "Must also have the 'mount' ability"));
        case ZFS_DELEG_NOTE_DESTROY:
                return (dgettext(TEXT_DOMAIN,
                    "Must also have the 'mount' ability"));
        case ZFS_DELEG_NOTE_SNAPSHOT:
                return (dgettext(TEXT_DOMAIN,
                    "Must also have the 'mount' ability"));
        case ZFS_DELEG_NOTE_ROLLBACK:
                return (dgettext(TEXT_DOMAIN,
                    "Must also have the 'mount' ability"));
        case ZFS_DELEG_NOTE_CLONE:
                return (dgettext(TEXT_DOMAIN, "Must also have the 'create' "
                    "ability and 'mount'\n"
                    "\t\t\t\tability in the origin file system"));
        case ZFS_DELEG_NOTE_PROMOTE:
                return (dgettext(TEXT_DOMAIN, "Must also have the 'mount'\n"
                    "\t\t\t\tand 'promote' ability in the origin file system"));
        case ZFS_DELEG_NOTE_RENAME:
                return (dgettext(TEXT_DOMAIN, "Must also have the 'mount' "
                    "and 'create' \n\t\t\t\tability in the new parent"));
        case ZFS_DELEG_NOTE_RECEIVE:
                return (dgettext(TEXT_DOMAIN, "Must also have the 'mount'"
                    " and 'create' ability"));
        case ZFS_DELEG_NOTE_USERPROP:
                return (dgettext(TEXT_DOMAIN,
                    "Allows changing any user property"));
        case ZFS_DELEG_NOTE_ALLOW:
                return (dgettext(TEXT_DOMAIN,
                    "Must also have the permission that is being\n"
                    "\t\t\t\tallowed"));
        case ZFS_DELEG_NOTE_MOUNT:
                return (dgettext(TEXT_DOMAIN,
                    "Allows mount/umount of ZFS datasets"));
        case ZFS_DELEG_NOTE_SHARE:
                return (dgettext(TEXT_DOMAIN,
                    "Allows sharing file systems over NFS or SMB\n"
                    "\t\t\t\tprotocols"));
        case ZFS_DELEG_NOTE_NONE:
        default:
                return (dgettext(TEXT_DOMAIN, ""));
        }
}

typedef enum {
        ZFS_DELEG_SUBCOMMAND,
        ZFS_DELEG_PROP,
        ZFS_DELEG_OTHER
} zfs_deleg_perm_type_t;

/*
 * is the permission a subcommand or other?
 */
zfs_deleg_perm_type_t
zfs_deleg_perm_type(const char *perm)
{
        if (strcmp(perm, "userprop") == 0)
                return (ZFS_DELEG_OTHER);
        else
                return (ZFS_DELEG_SUBCOMMAND);
}

static char *
zfs_deleg_perm_type_str(zfs_deleg_perm_type_t type)
{
        switch (type) {
        case ZFS_DELEG_SUBCOMMAND:
                return (dgettext(TEXT_DOMAIN, "subcommand"));
        case ZFS_DELEG_PROP:
                return (dgettext(TEXT_DOMAIN, "property"));
        case ZFS_DELEG_OTHER:
                return (dgettext(TEXT_DOMAIN, "other"));
        }
        return ("");
}

/*ARGSUSED*/
static int
zfs_deleg_prop_cb(int prop, void *cb)
{
        if (zfs_prop_delegatable(prop))
                (void) fprintf(stderr, "%-15s %-15s\n", zfs_prop_to_name(prop),
                    zfs_deleg_perm_type_str(ZFS_DELEG_PROP));

        return (ZPROP_CONT);
}

void
zfs_deleg_permissions(void)
{
        int i;

        (void) fprintf(stderr, "\n%-15s %-15s\t%s\n\n", "NAME",
            "TYPE", "NOTES");

        /*
         * First print out the subcommands
         */
        for (i = 0; zfs_deleg_perm_tab[i].z_perm != NULL; i++) {
                (void) fprintf(stderr, "%-15s %-15s\t%s\n",
                    zfs_deleg_perm_tab[i].z_perm,
                    zfs_deleg_perm_type_str(
                    zfs_deleg_perm_type(zfs_deleg_perm_tab[i].z_perm)),
                    zfs_deleg_perm_note(zfs_deleg_perm_tab[i].z_note));
        }

        (void) zprop_iter(zfs_deleg_prop_cb, NULL, B_FALSE, B_TRUE,
            ZFS_TYPE_DATASET|ZFS_TYPE_VOLUME);
}

/*
 * Given a property name and value, set the property for the given dataset.
 */
int
zfs_prop_set(zfs_handle_t *zhp, const char *propname, const char *propval)
{
        zfs_cmd_t zc = { 0 };
        int ret = -1;
        prop_changelist_t *cl = NULL;
        char errbuf[1024];
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        nvlist_t *nvl = NULL, *realprops;
        zfs_prop_t prop;
        boolean_t do_prefix;
        uint64_t idx;

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

        if (nvlist_alloc(&nvl, NV_UNIQUE_NAME, 0) != 0 ||
            nvlist_add_string(nvl, propname, propval) != 0) {
                (void) no_memory(hdl);
                goto error;
        }

        if ((realprops = zfs_valid_proplist(hdl, zhp->zfs_type, nvl,
            zfs_prop_get_int(zhp, ZFS_PROP_ZONED), zhp, errbuf)) == NULL)
                goto error;

        nvlist_free(nvl);
        nvl = realprops;

        prop = zfs_name_to_prop(propname);

        if ((cl = changelist_gather(zhp, prop, 0, 0)) == NULL)
                goto error;

        if (prop == ZFS_PROP_MOUNTPOINT && changelist_haszonedchild(cl)) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "child dataset with inherited mountpoint is used "
                    "in a non-global zone"));
                ret = zfs_error(hdl, EZFS_ZONED, errbuf);
                goto error;
        }

        /*
         * If the dataset's canmount property is being set to noauto,
         * then we want to prevent unmounting & remounting it.
         */
        do_prefix = !((prop == ZFS_PROP_CANMOUNT) &&
            (zprop_string_to_index(prop, propval, &idx,
            ZFS_TYPE_DATASET) == 0) && (idx == ZFS_CANMOUNT_NOAUTO));

        if (do_prefix && (ret = changelist_prefix(cl)) != 0)
                goto error;

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

        if (zcmd_write_src_nvlist(hdl, &zc, nvl) != 0)
                goto error;

        ret = zfs_ioctl(hdl, ZFS_IOC_SET_PROP, &zc);
        if (ret != 0) {
                switch (errno) {

                case ENOSPC:
                        /*
                         * For quotas and reservations, ENOSPC indicates
                         * something different; setting a quota or reservation
                         * doesn't use any disk space.
                         */
                        switch (prop) {
                        case ZFS_PROP_QUOTA:
                        case ZFS_PROP_REFQUOTA:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "size is less than current used or "
                                    "reserved space"));
                                (void) zfs_error(hdl, EZFS_PROPSPACE, errbuf);
                                break;

                        case ZFS_PROP_RESERVATION:
                        case ZFS_PROP_REFRESERVATION:
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "size is greater than available space"));
                                (void) zfs_error(hdl, EZFS_PROPSPACE, errbuf);
                                break;

                        default:
                                (void) zfs_standard_error(hdl, errno, errbuf);
                                break;
                        }
                        break;

                case EBUSY:
                        if (prop == ZFS_PROP_VOLBLOCKSIZE)
                                (void) zfs_error(hdl, EZFS_VOLHASDATA, errbuf);
                        else
                                (void) zfs_standard_error(hdl, EBUSY, errbuf);
                        break;

                case EROFS:
                        (void) zfs_error(hdl, EZFS_DSREADONLY, errbuf);
                        break;

                case ENOTSUP:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "pool and or dataset must be upgraded to set this "
                            "property or value"));
                        (void) zfs_error(hdl, EZFS_BADVERSION, errbuf);
                        break;

                case ERANGE:
                        if (prop == ZFS_PROP_COMPRESSION) {
                                (void) zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "property setting is not allowed on "
                                    "bootable datasets"));
                                (void) zfs_error(hdl, EZFS_NOTSUP, errbuf);
                        } else {
                                (void) zfs_standard_error(hdl, errno, errbuf);
                        }
                        break;

                case EOVERFLOW:
                        /*
                         * This platform can't address a volume this big.
                         */
#ifdef _ILP32
                        if (prop == ZFS_PROP_VOLSIZE) {
                                (void) zfs_error(hdl, EZFS_VOLTOOBIG, errbuf);
                                break;
                        }
#endif
                        /* FALLTHROUGH */
                default:
                        (void) zfs_standard_error(hdl, errno, errbuf);
                }
        } else {
                if (do_prefix)
                        ret = changelist_postfix(cl);

                /*
                 * Refresh the statistics so the new property value
                 * is reflected.
                 */
                if (ret == 0)
                        (void) get_stats(zhp);
        }

error:
        nvlist_free(nvl);
        zcmd_free_nvlists(&zc);
        if (cl)
                changelist_free(cl);
        return (ret);
}

/*
 * Given a property, inherit the value from the parent dataset.
 */
int
zfs_prop_inherit(zfs_handle_t *zhp, const char *propname)
{
        zfs_cmd_t zc = { 0 };
        int ret;
        prop_changelist_t *cl;
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        char errbuf[1024];
        zfs_prop_t prop;

        (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
            "cannot inherit %s for '%s'"), propname, zhp->zfs_name);

        if ((prop = zfs_name_to_prop(propname)) == ZPROP_INVAL) {
                /*
                 * For user properties, the amount of work we have to do is very
                 * small, so just do it here.
                 */
                if (!zfs_prop_user(propname)) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "invalid property"));
                        return (zfs_error(hdl, EZFS_BADPROP, errbuf));
                }

                (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
                (void) strlcpy(zc.zc_value, propname, sizeof (zc.zc_value));

                if (zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_INHERIT_PROP, &zc) != 0)
                        return (zfs_standard_error(hdl, errno, errbuf));

                return (0);
        }

        /*
         * Verify that this property is inheritable.
         */
        if (zfs_prop_readonly(prop))
                return (zfs_error(hdl, EZFS_PROPREADONLY, errbuf));

        if (!zfs_prop_inheritable(prop))
                return (zfs_error(hdl, EZFS_PROPNONINHERIT, errbuf));

        /*
         * Check to see if the value applies to this type
         */
        if (!zfs_prop_valid_for_type(prop, zhp->zfs_type))
                return (zfs_error(hdl, EZFS_PROPTYPE, errbuf));

        /*
         * Normalize the name, to get rid of shorthand abbrevations.
         */
        propname = zfs_prop_to_name(prop);
        (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
        (void) strlcpy(zc.zc_value, propname, sizeof (zc.zc_value));

        if (prop == ZFS_PROP_MOUNTPOINT && getzoneid() == GLOBAL_ZONEID &&
            zfs_prop_get_int(zhp, ZFS_PROP_ZONED)) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "dataset is used in a non-global zone"));
                return (zfs_error(hdl, EZFS_ZONED, errbuf));
        }

        /*
         * Determine datasets which will be affected by this change, if any.
         */
        if ((cl = changelist_gather(zhp, prop, 0, 0)) == NULL)
                return (-1);

        if (prop == ZFS_PROP_MOUNTPOINT && changelist_haszonedchild(cl)) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "child dataset with inherited mountpoint is used "
                    "in a non-global zone"));
                ret = zfs_error(hdl, EZFS_ZONED, errbuf);
                goto error;
        }

        if ((ret = changelist_prefix(cl)) != 0)
                goto error;

        if ((ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_INHERIT_PROP, &zc)) != 0) {
                return (zfs_standard_error(hdl, errno, errbuf));
        } else {

                if ((ret = changelist_postfix(cl)) != 0)
                        goto error;

                /*
                 * Refresh the statistics so the new property is reflected.
                 */
                (void) get_stats(zhp);
        }

error:
        changelist_free(cl);
        return (ret);
}

/*
 * True DSL properties are stored in an nvlist.  The following two functions
 * extract them appropriately.
 */
static uint64_t
getprop_uint64(zfs_handle_t *zhp, zfs_prop_t prop, char **source)
{
        nvlist_t *nv;
        uint64_t value;

        *source = NULL;
        if (nvlist_lookup_nvlist(zhp->zfs_props,
            zfs_prop_to_name(prop), &nv) == 0) {
                verify(nvlist_lookup_uint64(nv, ZPROP_VALUE, &value) == 0);
                (void) nvlist_lookup_string(nv, ZPROP_SOURCE, source);
        } else {
                value = zfs_prop_default_numeric(prop);
                *source = "";
        }

        return (value);
}

static char *
getprop_string(zfs_handle_t *zhp, zfs_prop_t prop, char **source)
{
        nvlist_t *nv;
        char *value;

        *source = NULL;
        if (nvlist_lookup_nvlist(zhp->zfs_props,
            zfs_prop_to_name(prop), &nv) == 0) {
                verify(nvlist_lookup_string(nv, ZPROP_VALUE, &value) == 0);
                (void) nvlist_lookup_string(nv, ZPROP_SOURCE, source);
        } else {
                if ((value = (char *)zfs_prop_default_string(prop)) == NULL)
                        value = "";
                *source = "";
        }

        return (value);
}

/*
 * Internal function for getting a numeric property.  Both zfs_prop_get() and
 * zfs_prop_get_int() are built using this interface.
 *
 * Certain properties can be overridden using 'mount -o'.  In this case, scan
 * the contents of the /etc/mnttab entry, searching for the appropriate options.
 * If they differ from the on-disk values, report the current values and mark
 * the source "temporary".
 */
static int
get_numeric_property(zfs_handle_t *zhp, zfs_prop_t prop, zprop_source_t *src,
    char **source, uint64_t *val)
{
        zfs_cmd_t zc = { 0 };
        nvlist_t *zplprops = NULL;
        struct mnttab mnt;
        char *mntopt_on = NULL;
        char *mntopt_off = NULL;

        *source = NULL;

        switch (prop) {
        case ZFS_PROP_ATIME:
                mntopt_on = MNTOPT_ATIME;
                mntopt_off = MNTOPT_NOATIME;
                break;

        case ZFS_PROP_DEVICES:
                mntopt_on = MNTOPT_DEVICES;
                mntopt_off = MNTOPT_NODEVICES;
                break;

        case ZFS_PROP_EXEC:
                mntopt_on = MNTOPT_EXEC;
                mntopt_off = MNTOPT_NOEXEC;
                break;

        case ZFS_PROP_READONLY:
                mntopt_on = MNTOPT_RO;
                mntopt_off = MNTOPT_RW;
                break;

        case ZFS_PROP_SETUID:
                mntopt_on = MNTOPT_SETUID;
                mntopt_off = MNTOPT_NOSETUID;
                break;

        case ZFS_PROP_XATTR:
                mntopt_on = MNTOPT_XATTR;
                mntopt_off = MNTOPT_NOXATTR;
                break;

        case ZFS_PROP_NBMAND:
                mntopt_on = MNTOPT_NBMAND;
                mntopt_off = MNTOPT_NONBMAND;
                break;
        }

        /*
         * Because looking up the mount options is potentially expensive
         * (iterating over all of /etc/mnttab), we defer its calculation until
         * we're looking up a property which requires its presence.
         */
        if (!zhp->zfs_mntcheck &&
            (mntopt_on != NULL || prop == ZFS_PROP_MOUNTED)) {
                struct mnttab entry, search = { 0 };
                FILE *mnttab = zhp->zfs_hdl->libzfs_mnttab;

                search.mnt_special = (char *)zhp->zfs_name;
                search.mnt_fstype = MNTTYPE_ZFS;
                rewind(mnttab);

                if (getmntany(mnttab, &entry, &search) == 0) {
                        zhp->zfs_mntopts = zfs_strdup(zhp->zfs_hdl,
                            entry.mnt_mntopts);
                        if (zhp->zfs_mntopts == NULL)
                                return (-1);
                }

                zhp->zfs_mntcheck = B_TRUE;
        }

        if (zhp->zfs_mntopts == NULL)
                mnt.mnt_mntopts = "";
        else
                mnt.mnt_mntopts = zhp->zfs_mntopts;

        switch (prop) {
        case ZFS_PROP_ATIME:
        case ZFS_PROP_DEVICES:
        case ZFS_PROP_EXEC:
        case ZFS_PROP_READONLY:
        case ZFS_PROP_SETUID:
        case ZFS_PROP_XATTR:
        case ZFS_PROP_NBMAND:
                *val = getprop_uint64(zhp, prop, source);

                if (hasmntopt(&mnt, mntopt_on) && !*val) {
                        *val = B_TRUE;
                        if (src)
                                *src = ZPROP_SRC_TEMPORARY;
                } else if (hasmntopt(&mnt, mntopt_off) && *val) {
                        *val = B_FALSE;
                        if (src)
                                *src = ZPROP_SRC_TEMPORARY;
                }
                break;

        case ZFS_PROP_CANMOUNT:
                *val = getprop_uint64(zhp, prop, source);
                if (*val != ZFS_CANMOUNT_ON)
                        *source = zhp->zfs_name;
                else
                        *source = "";   /* default */
                break;

        case ZFS_PROP_QUOTA:
        case ZFS_PROP_REFQUOTA:
        case ZFS_PROP_RESERVATION:
        case ZFS_PROP_REFRESERVATION:
                *val = getprop_uint64(zhp, prop, source);
                if (*val == 0)
                        *source = "";   /* default */
                else
                        *source = zhp->zfs_name;
                break;

        case ZFS_PROP_MOUNTED:
                *val = (zhp->zfs_mntopts != NULL);
                break;

        case ZFS_PROP_NUMCLONES:
                *val = zhp->zfs_dmustats.dds_num_clones;
                break;

        case ZFS_PROP_VERSION:
        case ZFS_PROP_NORMALIZE:
        case ZFS_PROP_UTF8ONLY:
        case ZFS_PROP_CASE:
                if (!zfs_prop_valid_for_type(prop, zhp->zfs_head_type) ||
                    zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
                        return (-1);
                (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
                if (zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_OBJSET_ZPLPROPS, &zc)) {
                        zcmd_free_nvlists(&zc);
                        zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
                            "unable to get %s property"),
                            zfs_prop_to_name(prop));
                        return (zfs_error(zhp->zfs_hdl, EZFS_BADVERSION,
                            dgettext(TEXT_DOMAIN, "internal error")));
                }
                if (zcmd_read_dst_nvlist(zhp->zfs_hdl, &zc, &zplprops) != 0 ||
                    nvlist_lookup_uint64(zplprops, zfs_prop_to_name(prop),
                    val) != 0) {
                        zcmd_free_nvlists(&zc);
                        zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
                            "unable to get %s property"),
                            zfs_prop_to_name(prop));
                        return (zfs_error(zhp->zfs_hdl, EZFS_NOMEM,
                            dgettext(TEXT_DOMAIN, "internal error")));
                }
                if (zplprops)
                        nvlist_free(zplprops);
                zcmd_free_nvlists(&zc);
                break;

        default:
                switch (zfs_prop_get_type(prop)) {
                case PROP_TYPE_NUMBER:
                case PROP_TYPE_INDEX:
                        *val = getprop_uint64(zhp, prop, source);
                        /*
                         * If we tried to use a defalut value for a
                         * readonly property, it means that it was not
                         * present; return an error.
                         */
                        if (zfs_prop_readonly(prop) &&
                            *source && (*source)[0] == '\0') {
                                return (-1);
                        }
                        break;

                case PROP_TYPE_STRING:
                default:
                        zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
                            "cannot get non-numeric property"));
                        return (zfs_error(zhp->zfs_hdl, EZFS_BADPROP,
                            dgettext(TEXT_DOMAIN, "internal error")));
                }
        }

        return (0);
}

/*
 * Calculate the source type, given the raw source string.
 */
static void
get_source(zfs_handle_t *zhp, zprop_source_t *srctype, char *source,
    char *statbuf, size_t statlen)
{
        if (statbuf == NULL || *srctype == ZPROP_SRC_TEMPORARY)
                return;

        if (source == NULL) {
                *srctype = ZPROP_SRC_NONE;
        } else if (source[0] == '\0') {
                *srctype = ZPROP_SRC_DEFAULT;
        } else {
                if (strcmp(source, zhp->zfs_name) == 0) {
                        *srctype = ZPROP_SRC_LOCAL;
                } else {
                        (void) strlcpy(statbuf, source, statlen);
                        *srctype = ZPROP_SRC_INHERITED;
                }
        }

}

/*
 * Retrieve a property from the given object.  If 'literal' is specified, then
 * numbers are left as exact values.  Otherwise, numbers are converted to a
 * human-readable form.
 *
 * Returns 0 on success, or -1 on error.
 */
int
zfs_prop_get(zfs_handle_t *zhp, zfs_prop_t prop, char *propbuf, size_t proplen,
    zprop_source_t *src, char *statbuf, size_t statlen, boolean_t literal)
{
        char *source = NULL;
        uint64_t val;
        char *str;
        const char *strval;

        /*
         * Check to see if this property applies to our object
         */
        if (!zfs_prop_valid_for_type(prop, zhp->zfs_type))
                return (-1);

        if (src)
                *src = ZPROP_SRC_NONE;

        switch (prop) {
        case ZFS_PROP_CREATION:
                /*
                 * 'creation' is a time_t stored in the statistics.  We convert
                 * this into a string unless 'literal' is specified.
                 */
                {
                        val = getprop_uint64(zhp, prop, &source);
                        time_t time = (time_t)val;
                        struct tm t;

                        if (literal ||
                            localtime_r(&time, &t) == NULL ||
                            strftime(propbuf, proplen, "%a %b %e %k:%M %Y",
                            &t) == 0)
                                (void) snprintf(propbuf, proplen, "%llu", val);
                }
                break;

        case ZFS_PROP_MOUNTPOINT:
                /*
                 * Getting the precise mountpoint can be tricky.
                 *
                 *  - for 'none' or 'legacy', return those values.
                 *  - for inherited mountpoints, we want to take everything
                 *    after our ancestor and append it to the inherited value.
                 *
                 * If the pool has an alternate root, we want to prepend that
                 * root to any values we return.
                 */

                str = getprop_string(zhp, prop, &source);

                if (str[0] == '/') {
                        char buf[MAXPATHLEN];
                        char *root = buf;
                        const char *relpath = zhp->zfs_name + strlen(source);

                        if (relpath[0] == '/')
                                relpath++;

                        if ((zpool_get_prop(zhp->zpool_hdl,
                            ZPOOL_PROP_ALTROOT, buf, MAXPATHLEN, NULL)) ||
                            (strcmp(root, "-") == 0))
                                root[0] = '\0';
                        /*
                         * Special case an alternate root of '/'. This will
                         * avoid having multiple leading slashes in the
                         * mountpoint path.
                         */
                        if (strcmp(root, "/") == 0)
                                root++;

                        /*
                         * If the mountpoint is '/' then skip over this
                         * if we are obtaining either an alternate root or
                         * an inherited mountpoint.
                         */
                        if (str[1] == '\0' && (root[0] != '\0' ||
                            relpath[0] != '\0'))
                                str++;

                        if (relpath[0] == '\0')
                                (void) snprintf(propbuf, proplen, "%s%s",
                                    root, str);
                        else
                                (void) snprintf(propbuf, proplen, "%s%s%s%s",
                                    root, str, relpath[0] == '@' ? "" : "/",
                                    relpath);
                } else {
                        /* 'legacy' or 'none' */
                        (void) strlcpy(propbuf, str, proplen);
                }

                break;

        case ZFS_PROP_ORIGIN:
                (void) strlcpy(propbuf, getprop_string(zhp, prop, &source),
                    proplen);
                /*
                 * If there is no parent at all, return failure to indicate that
                 * it doesn't apply to this dataset.
                 */
                if (propbuf[0] == '\0')
                        return (-1);
                break;

        case ZFS_PROP_QUOTA:
        case ZFS_PROP_REFQUOTA:
        case ZFS_PROP_RESERVATION:
        case ZFS_PROP_REFRESERVATION:

                if (get_numeric_property(zhp, prop, src, &source, &val) != 0)
                        return (-1);

                /*
                 * If quota or reservation is 0, we translate this into 'none'
                 * (unless literal is set), and indicate that it's the default
                 * value.  Otherwise, we print the number nicely and indicate
                 * that its set locally.
                 */
                if (val == 0) {
                        if (literal)
                                (void) strlcpy(propbuf, "0", proplen);
                        else
                                (void) strlcpy(propbuf, "none", proplen);
                } else {
                        if (literal)
                                (void) snprintf(propbuf, proplen, "%llu",
                                    (u_longlong_t)val);
                        else
                                zfs_nicenum(val, propbuf, proplen);
                }
                break;

        case ZFS_PROP_COMPRESSRATIO:
                if (get_numeric_property(zhp, prop, src, &source, &val) != 0)
                        return (-1);
                (void) snprintf(propbuf, proplen, "%lld.%02lldx", (longlong_t)
                    val / 100, (longlong_t)val % 100);
                break;

        case ZFS_PROP_TYPE:
                switch (zhp->zfs_type) {
                case ZFS_TYPE_FILESYSTEM:
                        str = "filesystem";
                        break;
                case ZFS_TYPE_VOLUME:
                        str = "volume";
                        break;
                case ZFS_TYPE_SNAPSHOT:
                        str = "snapshot";
                        break;
                default:
                        abort();
                }
                (void) snprintf(propbuf, proplen, "%s", str);
                break;

        case ZFS_PROP_MOUNTED:
                /*
                 * The 'mounted' property is a pseudo-property that described
                 * whether the filesystem is currently mounted.  Even though
                 * it's a boolean value, the typical values of "on" and "off"
                 * don't make sense, so we translate to "yes" and "no".
                 */
                if (get_numeric_property(zhp, ZFS_PROP_MOUNTED,
                    src, &source, &val) != 0)
                        return (-1);
                if (val)
                        (void) strlcpy(propbuf, "yes", proplen);
                else
                        (void) strlcpy(propbuf, "no", proplen);
                break;

        case ZFS_PROP_NAME:
                /*
                 * The 'name' property is a pseudo-property derived from the
                 * dataset name.  It is presented as a real property to simplify
                 * consumers.
                 */
                (void) strlcpy(propbuf, zhp->zfs_name, proplen);
                break;

        default:
                switch (zfs_prop_get_type(prop)) {
                case PROP_TYPE_NUMBER:
                        if (get_numeric_property(zhp, prop, src,
                            &source, &val) != 0)
                                return (-1);
                        if (literal)
                                (void) snprintf(propbuf, proplen, "%llu",
                                    (u_longlong_t)val);
                        else
                                zfs_nicenum(val, propbuf, proplen);
                        break;

                case PROP_TYPE_STRING:
                        (void) strlcpy(propbuf,
                            getprop_string(zhp, prop, &source), proplen);
                        break;

                case PROP_TYPE_INDEX:
                        if (get_numeric_property(zhp, prop, src,
                            &source, &val) != 0)
                                return (-1);
                        if (zfs_prop_index_to_string(prop, val, &strval) != 0)
                                return (-1);
                        (void) strlcpy(propbuf, strval, proplen);
                        break;

                default:
                        abort();
                }
        }

        get_source(zhp, src, source, statbuf, statlen);

        return (0);
}

/*
 * Utility function to get the given numeric property.  Does no validation that
 * the given property is the appropriate type; should only be used with
 * hard-coded property types.
 */
uint64_t
zfs_prop_get_int(zfs_handle_t *zhp, zfs_prop_t prop)
{
        char *source;
        uint64_t val;

        (void) get_numeric_property(zhp, prop, NULL, &source, &val);

        return (val);
}

int
zfs_prop_set_int(zfs_handle_t *zhp, zfs_prop_t prop, uint64_t val)
{
        char buf[64];

        zfs_nicenum(val, buf, sizeof (buf));
        return (zfs_prop_set(zhp, zfs_prop_to_name(prop), buf));
}

/*
 * Similar to zfs_prop_get(), but returns the value as an integer.
 */
int
zfs_prop_get_numeric(zfs_handle_t *zhp, zfs_prop_t prop, uint64_t *value,
    zprop_source_t *src, char *statbuf, size_t statlen)
{
        char *source;

        /*
         * Check to see if this property applies to our object
         */
        if (!zfs_prop_valid_for_type(prop, zhp->zfs_type)) {
                return (zfs_error_fmt(zhp->zfs_hdl, EZFS_PROPTYPE,
                    dgettext(TEXT_DOMAIN, "cannot get property '%s'"),
                    zfs_prop_to_name(prop)));
        }

        if (src)
                *src = ZPROP_SRC_NONE;

        if (get_numeric_property(zhp, prop, src, &source, value) != 0)
                return (-1);

        get_source(zhp, src, source, statbuf, statlen);

        return (0);
}

/*
 * Returns the name of the given zfs handle.
 */
const char *
zfs_get_name(const zfs_handle_t *zhp)
{
        return (zhp->zfs_name);
}

/*
 * Returns the type of the given zfs handle.
 */
zfs_type_t
zfs_get_type(const zfs_handle_t *zhp)
{
        return (zhp->zfs_type);
}

/*
 * Iterate over all child filesystems
 */
int
zfs_iter_filesystems(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
        zfs_cmd_t zc = { 0 };
        zfs_handle_t *nzhp;
        int ret;

        if (zhp->zfs_type != ZFS_TYPE_FILESYSTEM)
                return (0);

        for ((void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
            ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DATASET_LIST_NEXT, &zc) == 0;
            (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name))) {
                /*
                 * Ignore private dataset names.
                 */
                if (dataset_name_hidden(zc.zc_name))
                        continue;

                /*
                 * Silently ignore errors, as the only plausible explanation is
                 * that the pool has since been removed.
                 */
                if ((nzhp = make_dataset_handle(zhp->zfs_hdl,
                    zc.zc_name)) == NULL)
                        continue;

                if ((ret = func(nzhp, data)) != 0)
                        return (ret);
        }

        /*
         * An errno value of ESRCH indicates normal completion.  If ENOENT is
         * returned, then the underlying dataset has been removed since we
         * obtained the handle.
         */
        if (errno != ESRCH && errno != ENOENT)
                return (zfs_standard_error(zhp->zfs_hdl, errno,
                    dgettext(TEXT_DOMAIN, "cannot iterate filesystems")));

        return (0);
}

/*
 * Iterate over all snapshots
 */
int
zfs_iter_snapshots(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
        zfs_cmd_t zc = { 0 };
        zfs_handle_t *nzhp;
        int ret;

        if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT)
                return (0);

        for ((void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
            ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_SNAPSHOT_LIST_NEXT,
            &zc) == 0;
            (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name))) {

                if ((nzhp = make_dataset_handle(zhp->zfs_hdl,
                    zc.zc_name)) == NULL)
                        continue;

                if ((ret = func(nzhp, data)) != 0)
                        return (ret);
        }

        /*
         * An errno value of ESRCH indicates normal completion.  If ENOENT is
         * returned, then the underlying dataset has been removed since we
         * obtained the handle.  Silently ignore this case, and return success.
         */
        if (errno != ESRCH && errno != ENOENT)
                return (zfs_standard_error(zhp->zfs_hdl, errno,
                    dgettext(TEXT_DOMAIN, "cannot iterate filesystems")));

        return (0);
}

/*
 * Iterate over all children, snapshots and filesystems
 */
int
zfs_iter_children(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
        int ret;

        if ((ret = zfs_iter_filesystems(zhp, func, data)) != 0)
                return (ret);

        return (zfs_iter_snapshots(zhp, func, data));
}

/*
 * Given a complete name, return just the portion that refers to the parent.
 * Can return NULL if this is a pool.
 */
static int
parent_name(const char *path, char *buf, size_t buflen)
{
        char *loc;

        if ((loc = strrchr(path, '/')) == NULL)
                return (-1);

        (void) strncpy(buf, path, MIN(buflen, loc - path));
        buf[loc - path] = '\0';

        return (0);
}

/*
 * If accept_ancestor is false, then check to make sure that the given path has
 * a parent, and that it exists.  If accept_ancestor is true, then find the
 * closest existing ancestor for the given path.  In prefixlen return the
 * length of already existing prefix of the given path.  We also fetch the
 * 'zoned' property, which is used to validate property settings when creating
 * new datasets.
 */
static int
check_parents(libzfs_handle_t *hdl, const char *path, uint64_t *zoned,
    boolean_t accept_ancestor, int *prefixlen)
{
        zfs_cmd_t zc = { 0 };
        char parent[ZFS_MAXNAMELEN];
        char *slash;
        zfs_handle_t *zhp;
        char errbuf[1024];

        (void) snprintf(errbuf, sizeof (errbuf), "cannot create '%s'",
            path);

        /* get parent, and check to see if this is just a pool */
        if (parent_name(path, parent, sizeof (parent)) != 0) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "missing dataset name"));
                return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
        }

        /* check to see if the pool exists */
        if ((slash = strchr(parent, '/')) == NULL)
                slash = parent + strlen(parent);
        (void) strncpy(zc.zc_name, parent, slash - parent);
        zc.zc_name[slash - parent] = '\0';
        if (ioctl(hdl->libzfs_fd, ZFS_IOC_OBJSET_STATS, &zc) != 0 &&
            errno == ENOENT) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "no such pool '%s'"), zc.zc_name);
                return (zfs_error(hdl, EZFS_NOENT, errbuf));
        }

        /* check to see if the parent dataset exists */
        while ((zhp = make_dataset_handle(hdl, parent)) == NULL) {
                if (errno == ENOENT && accept_ancestor) {
                        /*
                         * Go deeper to find an ancestor, give up on top level.
                         */
                        if (parent_name(parent, parent, sizeof (parent)) != 0) {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "no such pool '%s'"), zc.zc_name);
                                return (zfs_error(hdl, EZFS_NOENT, errbuf));
                        }
                } else if (errno == ENOENT) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "parent does not exist"));
                        return (zfs_error(hdl, EZFS_NOENT, errbuf));
                } else
                        return (zfs_standard_error(hdl, errno, errbuf));
        }

        *zoned = zfs_prop_get_int(zhp, ZFS_PROP_ZONED);
        /* we are in a non-global zone, but parent is in the global zone */
        if (getzoneid() != GLOBAL_ZONEID && !(*zoned)) {
                (void) zfs_standard_error(hdl, EPERM, errbuf);
                zfs_close(zhp);
                return (-1);
        }

        /* make sure parent is a filesystem */
        if (zfs_get_type(zhp) != ZFS_TYPE_FILESYSTEM) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "parent is not a filesystem"));
                (void) zfs_error(hdl, EZFS_BADTYPE, errbuf);
                zfs_close(zhp);
                return (-1);
        }

        zfs_close(zhp);
        if (prefixlen != NULL)
                *prefixlen = strlen(parent);
        return (0);
}

/*
 * Finds whether the dataset of the given type(s) exists.
 */
boolean_t
zfs_dataset_exists(libzfs_handle_t *hdl, const char *path, zfs_type_t types)
{
        zfs_handle_t *zhp;

        if (!zfs_validate_name(hdl, path, types, B_FALSE))
                return (B_FALSE);

        /*
         * Try to get stats for the dataset, which will tell us if it exists.
         */
        if ((zhp = make_dataset_handle(hdl, path)) != NULL) {
                int ds_type = zhp->zfs_type;

                zfs_close(zhp);
                if (types & ds_type)
                        return (B_TRUE);
        }
        return (B_FALSE);
}

/*
 * Given a path to 'target', create all the ancestors between
 * the prefixlen portion of the path, and the target itself.
 * Fail if the initial prefixlen-ancestor does not already exist.
 */
int
create_parents(libzfs_handle_t *hdl, char *target, int prefixlen)
{
        zfs_handle_t *h;
        char *cp;
        const char *opname;

        /* make sure prefix exists */
        cp = target + prefixlen;
        if (*cp != '/') {
                assert(strchr(cp, '/') == NULL);
                h = zfs_open(hdl, target, ZFS_TYPE_FILESYSTEM);
        } else {
                *cp = '\0';
                h = zfs_open(hdl, target, ZFS_TYPE_FILESYSTEM);
                *cp = '/';
        }
        if (h == NULL)
                return (-1);
        zfs_close(h);

        /*
         * Attempt to create, mount, and share any ancestor filesystems,
         * up to the prefixlen-long one.
         */
        for (cp = target + prefixlen + 1;
            cp = strchr(cp, '/'); *cp = '/', cp++) {
                char *logstr;

                *cp = '\0';

                h = make_dataset_handle(hdl, target);
                if (h) {
                        /* it already exists, nothing to do here */
                        zfs_close(h);
                        continue;
                }

                logstr = hdl->libzfs_log_str;
                hdl->libzfs_log_str = NULL;
                if (zfs_create(hdl, target, ZFS_TYPE_FILESYSTEM,
                    NULL) != 0) {
                        hdl->libzfs_log_str = logstr;
                        opname = dgettext(TEXT_DOMAIN, "create");
                        goto ancestorerr;
                }

                hdl->libzfs_log_str = logstr;
                h = zfs_open(hdl, target, ZFS_TYPE_FILESYSTEM);
                if (h == NULL) {
                        opname = dgettext(TEXT_DOMAIN, "open");
                        goto ancestorerr;
                }

                if (zfs_mount(h, NULL, 0) != 0) {
                        opname = dgettext(TEXT_DOMAIN, "mount");
                        goto ancestorerr;
                }

                if (zfs_share(h) != 0) {
                        opname = dgettext(TEXT_DOMAIN, "share");
                        goto ancestorerr;
                }

                zfs_close(h);
        }

        return (0);

ancestorerr:
        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
            "failed to %s ancestor '%s'"), opname, target);
        return (-1);
}

/*
 * Creates non-existing ancestors of the given path.
 */
int
zfs_create_ancestors(libzfs_handle_t *hdl, const char *path)
{
        int prefix;
        uint64_t zoned;
        char *path_copy;
        int rc;

        if (check_parents(hdl, path, &zoned, B_TRUE, &prefix) != 0)
                return (-1);

        if ((path_copy = strdup(path)) != NULL) {
                rc = create_parents(hdl, path_copy, prefix);
                free(path_copy);
        }
        if (path_copy == NULL || rc != 0)
                return (-1);

        return (0);
}

/*
 * Create a new filesystem or volume.
 */
int
zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
    nvlist_t *props)
{
        zfs_cmd_t zc = { 0 };
        int ret;
        uint64_t size = 0;
        uint64_t blocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
        char errbuf[1024];
        uint64_t zoned;

        (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
            "cannot create '%s'"), path);

        /* validate the path, taking care to note the extended error message */
        if (!zfs_validate_name(hdl, path, type, B_TRUE))
                return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));

        /* validate parents exist */
        if (check_parents(hdl, path, &zoned, B_FALSE, NULL) != 0)
                return (-1);

        /*
         * The failure modes when creating a dataset of a different type over
         * one that already exists is a little strange.  In particular, if you
         * try to create a dataset on top of an existing dataset, the ioctl()
         * will return ENOENT, not EEXIST.  To prevent this from happening, we
         * first try to see if the dataset exists.
         */
        (void) strlcpy(zc.zc_name, path, sizeof (zc.zc_name));
        if (zfs_dataset_exists(hdl, zc.zc_name, ZFS_TYPE_DATASET)) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "dataset already exists"));
                return (zfs_error(hdl, EZFS_EXISTS, errbuf));
        }

        if (type == ZFS_TYPE_VOLUME)
                zc.zc_objset_type = DMU_OST_ZVOL;
        else
                zc.zc_objset_type = DMU_OST_ZFS;

        if (props && (props = zfs_valid_proplist(hdl, type, props,
            zoned, NULL, errbuf)) == 0)
                return (-1);

        if (type == ZFS_TYPE_VOLUME) {
                /*
                 * If we are creating a volume, the size and block size must
                 * satisfy a few restraints.  First, the blocksize must be a
                 * valid block size between SPA_{MIN,MAX}BLOCKSIZE.  Second, the
                 * volsize must be a multiple of the block size, and cannot be
                 * zero.
                 */
                if (props == NULL || nvlist_lookup_uint64(props,
                    zfs_prop_to_name(ZFS_PROP_VOLSIZE), &size) != 0) {
                        nvlist_free(props);
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "missing volume size"));
                        return (zfs_error(hdl, EZFS_BADPROP, errbuf));
                }

                if ((ret = nvlist_lookup_uint64(props,
                    zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE),
                    &blocksize)) != 0) {
                        if (ret == ENOENT) {
                                blocksize = zfs_prop_default_numeric(
                                    ZFS_PROP_VOLBLOCKSIZE);
                        } else {
                                nvlist_free(props);
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "missing volume block size"));
                                return (zfs_error(hdl, EZFS_BADPROP, errbuf));
                        }
                }

                if (size == 0) {
                        nvlist_free(props);
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "volume size cannot be zero"));
                        return (zfs_error(hdl, EZFS_BADPROP, errbuf));
                }

                if (size % blocksize != 0) {
                        nvlist_free(props);
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "volume size must be a multiple of volume block "
                            "size"));
                        return (zfs_error(hdl, EZFS_BADPROP, errbuf));
                }
        }

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

        /* create the dataset */
        ret = zfs_ioctl(hdl, ZFS_IOC_CREATE, &zc);

        if (ret == 0 && type == ZFS_TYPE_VOLUME) {
                ret = zvol_create_link(hdl, path);
                if (ret) {
                        (void) zfs_standard_error(hdl, errno,
                            dgettext(TEXT_DOMAIN,
                            "Volume successfully created, but device links "
                            "were not created"));
                        zcmd_free_nvlists(&zc);
                        return (-1);
                }
        }

        zcmd_free_nvlists(&zc);

        /* check for failure */
        if (ret != 0) {
                char parent[ZFS_MAXNAMELEN];
                (void) parent_name(path, parent, sizeof (parent));

                switch (errno) {
                case ENOENT:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "no such parent '%s'"), parent);
                        return (zfs_error(hdl, EZFS_NOENT, errbuf));

                case EINVAL:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "parent '%s' is not a filesystem"), parent);
                        return (zfs_error(hdl, EZFS_BADTYPE, errbuf));

                case EDOM:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "volume block size must be power of 2 from "
                            "%u to %uk"),
                            (uint_t)SPA_MINBLOCKSIZE,
                            (uint_t)SPA_MAXBLOCKSIZE >> 10);

                        return (zfs_error(hdl, EZFS_BADPROP, errbuf));

                case ENOTSUP:
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "pool must be upgraded to set this "
                            "property or value"));
                        return (zfs_error(hdl, EZFS_BADVERSION, errbuf));
#ifdef _ILP32
                case EOVERFLOW:
                        /*
                         * This platform can't address a volume this big.
                         */
                        if (type == ZFS_TYPE_VOLUME)
                                return (zfs_error(hdl, EZFS_VOLTOOBIG,
                                    errbuf));
#endif
                        /* FALLTHROUGH */
                default:
                        return (zfs_standard_error(hdl, errno, errbuf));
                }
        }

        return (0);
}

/*
 * Destroys the given dataset.  The caller must make sure that the filesystem
 * isn't mounted, and that there are no active dependents.
 */
int
zfs_destroy(zfs_handle_t *zhp)
{
        zfs_cmd_t zc = { 0 };

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

        if (ZFS_IS_VOLUME(zhp)) {
                /*
                 * If user doesn't have permissions to unshare volume, then
                 * abort the request.  This would only happen for a
                 * non-privileged user.
                 */
                if (zfs_unshare_iscsi(zhp) != 0) {
                        return (-1);
                }

                if (zvol_remove_link(zhp->zfs_hdl, zhp->zfs_name) != 0)
                        return (-1);

                zc.zc_objset_type = DMU_OST_ZVOL;
        } else {
                zc.zc_objset_type = DMU_OST_ZFS;
        }

        if (zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_DESTROY, &zc) != 0) {
                return (zfs_standard_error_fmt(zhp->zfs_hdl, errno,
                    dgettext(TEXT_DOMAIN, "cannot destroy '%s'"),
                    zhp->zfs_name));
        }

        remove_mountpoint(zhp);

        return (0);
}

struct destroydata {
        char *snapname;
        boolean_t gotone;
        boolean_t closezhp;
};

static int
zfs_remove_link_cb(zfs_handle_t *zhp, void *arg)
{
        struct destroydata *dd = arg;
        zfs_handle_t *szhp;
        char name[ZFS_MAXNAMELEN];
        boolean_t closezhp = dd->closezhp;
        int rv;

        (void) strlcpy(name, zhp->zfs_name, sizeof (name));
        (void) strlcat(name, "@", sizeof (name));
        (void) strlcat(name, dd->snapname, sizeof (name));

        szhp = make_dataset_handle(zhp->zfs_hdl, name);
        if (szhp) {
                dd->gotone = B_TRUE;
                zfs_close(szhp);
        }

        if (zhp->zfs_type == ZFS_TYPE_VOLUME) {
                (void) zvol_remove_link(zhp->zfs_hdl, name);
                /*
                 * NB: this is simply a best-effort.  We don't want to
                 * return an error, because then we wouldn't visit all
                 * the volumes.
                 */
        }

        dd->closezhp = B_TRUE;
        rv = zfs_iter_filesystems(zhp, zfs_remove_link_cb, arg);
        if (closezhp)
                zfs_close(zhp);
        return (rv);
}

/*
 * Destroys all snapshots with the given name in zhp & descendants.
 */
int
zfs_destroy_snaps(zfs_handle_t *zhp, char *snapname)
{
        zfs_cmd_t zc = { 0 };
        int ret;
        struct destroydata dd = { 0 };

        dd.snapname = snapname;
        (void) zfs_remove_link_cb(zhp, &dd);

        if (!dd.gotone) {
                return (zfs_standard_error_fmt(zhp->zfs_hdl, ENOENT,
                    dgettext(TEXT_DOMAIN, "cannot destroy '%s@%s'"),
                    zhp->zfs_name, snapname));
        }

        (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
        (void) strlcpy(zc.zc_value, snapname, sizeof (zc.zc_value));

        ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_DESTROY_SNAPS, &zc);
        if (ret != 0) {
                char errbuf[1024];

                (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
                    "cannot destroy '%s@%s'"), zc.zc_name, snapname);

                switch (errno) {
                case EEXIST:
                        zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
                            "snapshot is cloned"));
                        return (zfs_error(zhp->zfs_hdl, EZFS_EXISTS, errbuf));

                default:
                        return (zfs_standard_error(zhp->zfs_hdl, errno,
                            errbuf));
                }
        }

        return (0);
}

/*
 * Clones the given dataset.  The target must be of the same type as the source.
 */
int
zfs_clone(zfs_handle_t *zhp, const char *target, nvlist_t *props)
{
        zfs_cmd_t zc = { 0 };
        char parent[ZFS_MAXNAMELEN];
        int ret;
        char errbuf[1024];
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        zfs_type_t type;
        uint64_t zoned;

        assert(zhp->zfs_type == ZFS_TYPE_SNAPSHOT);

        (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
            "cannot create '%s'"), target);

        /* validate the target name */
        if (!zfs_validate_name(hdl, target, ZFS_TYPE_FILESYSTEM, B_TRUE))
                return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));

        /* validate parents exist */
        if (check_parents(hdl, target, &zoned, B_FALSE, NULL) != 0)
                return (-1);

        (void) parent_name(target, parent, sizeof (parent));

        /* do the clone */
        if (ZFS_IS_VOLUME(zhp)) {
                zc.zc_objset_type = DMU_OST_ZVOL;
                type = ZFS_TYPE_VOLUME;
        } else {
                zc.zc_objset_type = DMU_OST_ZFS;
                type = ZFS_TYPE_FILESYSTEM;
        }

        if (props) {
                if ((props = zfs_valid_proplist(hdl, type, props, zoned,
                    zhp, 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, target, sizeof (zc.zc_name));
        (void) strlcpy(zc.zc_value, zhp->zfs_name, sizeof (zc.zc_value));
        ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_CREATE, &zc);

        zcmd_free_nvlists(&zc);

        if (ret != 0) {
                switch (errno) {

                case ENOENT:
                        /*
                         * The parent doesn't exist.  We should have caught this
                         * above, but there may a race condition that has since
                         * destroyed the parent.
                         *
                         * At this point, we don't know whether it's the source
                         * that doesn't exist anymore, or whether the target
                         * dataset doesn't exist.
                         */
                        zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
                            "no such parent '%s'"), parent);
                        return (zfs_error(zhp->zfs_hdl, EZFS_NOENT, errbuf));

                case EXDEV:
                        zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
                            "source and target pools differ"));
                        return (zfs_error(zhp->zfs_hdl, EZFS_CROSSTARGET,
                            errbuf));

                default:
                        return (zfs_standard_error(zhp->zfs_hdl, errno,
                            errbuf));
                }
        } else if (ZFS_IS_VOLUME(zhp)) {
                ret = zvol_create_link(zhp->zfs_hdl, target);
        }

        return (ret);
}

typedef struct promote_data {
        char cb_mountpoint[MAXPATHLEN];
        const char *cb_target;
        const char *cb_errbuf;
        uint64_t cb_pivot_txg;
} promote_data_t;

static int
promote_snap_cb(zfs_handle_t *zhp, void *data)
{
        promote_data_t *pd = data;
        zfs_handle_t *szhp;
        char snapname[MAXPATHLEN];
        int rv = 0;

        /* We don't care about snapshots after the pivot point */
        if (zfs_prop_get_int(zhp, ZFS_PROP_CREATETXG) > pd->cb_pivot_txg) {
                zfs_close(zhp);
                return (0);
        }

        /* Remove the device link if it's a zvol. */
        if (ZFS_IS_VOLUME(zhp))
                (void) zvol_remove_link(zhp->zfs_hdl, zhp->zfs_name);

        /* Check for conflicting names */
        (void) strlcpy(snapname, pd->cb_target, sizeof (snapname));
        (void) strlcat(snapname, strchr(zhp->zfs_name, '@'), sizeof (snapname));
        szhp = make_dataset_handle(zhp->zfs_hdl, snapname);
        if (szhp != NULL) {
                zfs_close(szhp);
                zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
                    "snapshot name '%s' from origin \n"
                    "conflicts with '%s' from target"),
                    zhp->zfs_name, snapname);
                rv = zfs_error(zhp->zfs_hdl, EZFS_EXISTS, pd->cb_errbuf);
        }
        zfs_close(zhp);
        return (rv);
}

static int
promote_snap_done_cb(zfs_handle_t *zhp, void *data)
{
        promote_data_t *pd = data;

        /* We don't care about snapshots after the pivot point */
        if (zfs_prop_get_int(zhp, ZFS_PROP_CREATETXG) <= pd->cb_pivot_txg) {
                /* Create the device link if it's a zvol. */
                if (ZFS_IS_VOLUME(zhp))
                        (void) zvol_create_link(zhp->zfs_hdl, zhp->zfs_name);
        }

        zfs_close(zhp);
        return (0);
}

/*
 * Promotes the given clone fs to be the clone parent.
 */
int
zfs_promote(zfs_handle_t *zhp)
{
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        zfs_cmd_t zc = { 0 };
        char parent[MAXPATHLEN];
        char *cp;
        int ret;
        zfs_handle_t *pzhp;
        promote_data_t pd;
        char errbuf[1024];

        (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
            "cannot promote '%s'"), zhp->zfs_name);

        if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "snapshots can not be promoted"));
                return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
        }

        (void) strlcpy(parent, zhp->zfs_dmustats.dds_origin, sizeof (parent));
        if (parent[0] == '\0') {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "not a cloned filesystem"));
                return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
        }
        cp = strchr(parent, '@');
        *cp = '\0';

        /* Walk the snapshots we will be moving */
        pzhp = zfs_open(hdl, zhp->zfs_dmustats.dds_origin, ZFS_TYPE_SNAPSHOT);
        if (pzhp == NULL)
                return (-1);
        pd.cb_pivot_txg = zfs_prop_get_int(pzhp, ZFS_PROP_CREATETXG);
        zfs_close(pzhp);
        pd.cb_target = zhp->zfs_name;
        pd.cb_errbuf = errbuf;
        pzhp = zfs_open(hdl, parent, ZFS_TYPE_DATASET);
        if (pzhp == NULL)
                return (-1);
        (void) zfs_prop_get(pzhp, ZFS_PROP_MOUNTPOINT, pd.cb_mountpoint,
            sizeof (pd.cb_mountpoint), NULL, NULL, 0, FALSE);
        ret = zfs_iter_snapshots(pzhp, promote_snap_cb, &pd);
        if (ret != 0) {
                zfs_close(pzhp);
                return (-1);
        }

        /* issue the ioctl */
        (void) strlcpy(zc.zc_value, zhp->zfs_dmustats.dds_origin,
            sizeof (zc.zc_value));
        (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
        ret = zfs_ioctl(hdl, ZFS_IOC_PROMOTE, &zc);

        if (ret != 0) {
                int save_errno = errno;

                (void) zfs_iter_snapshots(pzhp, promote_snap_done_cb, &pd);
                zfs_close(pzhp);

                switch (save_errno) {
                case EEXIST:
                        /*
                         * There is a conflicting snapshot name.  We
                         * should have caught this above, but they could
                         * have renamed something in the mean time.
                         */
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "conflicting snapshot name from parent '%s'"),
                            parent);
                        return (zfs_error(hdl, EZFS_EXISTS, errbuf));

                default:
                        return (zfs_standard_error(hdl, save_errno, errbuf));
                }
        } else {
                (void) zfs_iter_snapshots(zhp, promote_snap_done_cb, &pd);
        }

        zfs_close(pzhp);
        return (ret);
}

struct createdata {
        const char *cd_snapname;
        int cd_ifexists;
};

static int
zfs_create_link_cb(zfs_handle_t *zhp, void *arg)
{
        struct createdata *cd = arg;
        int ret;

        if (zhp->zfs_type == ZFS_TYPE_VOLUME) {
                char name[MAXPATHLEN];

                (void) strlcpy(name, zhp->zfs_name, sizeof (name));
                (void) strlcat(name, "@", sizeof (name));
                (void) strlcat(name, cd->cd_snapname, sizeof (name));
                (void) zvol_create_link_common(zhp->zfs_hdl, name,
                    cd->cd_ifexists);
                /*
                 * NB: this is simply a best-effort.  We don't want to
                 * return an error, because then we wouldn't visit all
                 * the volumes.
                 */
        }

        ret = zfs_iter_filesystems(zhp, zfs_create_link_cb, cd);

        zfs_close(zhp);

        return (ret);
}

/*
 * Takes a snapshot of the given dataset.
 */
int
zfs_snapshot(libzfs_handle_t *hdl, const char *path, boolean_t recursive,
    nvlist_t *props)
{
        const char *delim;
        char parent[ZFS_MAXNAMELEN];
        zfs_handle_t *zhp;
        zfs_cmd_t zc = { 0 };
        int ret;
        char errbuf[1024];

        (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
            "cannot snapshot '%s'"), path);

        /* validate the target name */
        if (!zfs_validate_name(hdl, path, ZFS_TYPE_SNAPSHOT, B_TRUE))
                return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));

        if (props) {
                if ((props = zfs_valid_proplist(hdl, ZFS_TYPE_SNAPSHOT,
                    props, B_FALSE, NULL, errbuf)) == NULL)
                        return (-1);

                if (zcmd_write_src_nvlist(hdl, &zc, props) != 0) {
                        nvlist_free(props);
                        return (-1);
                }

                nvlist_free(props);
        }

        /* make sure the parent exists and is of the appropriate type */
        delim = strchr(path, '@');
        (void) strncpy(parent, path, delim - path);
        parent[delim - path] = '\0';

        if ((zhp = zfs_open(hdl, parent, ZFS_TYPE_FILESYSTEM |
            ZFS_TYPE_VOLUME)) == NULL) {
                zcmd_free_nvlists(&zc);
                return (-1);
        }

        (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
        (void) strlcpy(zc.zc_value, delim+1, sizeof (zc.zc_value));
        if (ZFS_IS_VOLUME(zhp))
                zc.zc_objset_type = DMU_OST_ZVOL;
        else
                zc.zc_objset_type = DMU_OST_ZFS;
        zc.zc_cookie = recursive;
        ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_SNAPSHOT, &zc);

        zcmd_free_nvlists(&zc);

        /*
         * if it was recursive, the one that actually failed will be in
         * zc.zc_name.
         */
        if (ret != 0)
                (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
                    "cannot create snapshot '%s@%s'"), zc.zc_name, zc.zc_value);

        if (ret == 0 && recursive) {
                struct createdata cd;

                cd.cd_snapname = delim + 1;
                cd.cd_ifexists = B_FALSE;
                (void) zfs_iter_filesystems(zhp, zfs_create_link_cb, &cd);
        }
        if (ret == 0 && zhp->zfs_type == ZFS_TYPE_VOLUME) {
                ret = zvol_create_link(zhp->zfs_hdl, path);
                if (ret != 0) {
                        (void) zfs_standard_error(hdl, errno,
                            dgettext(TEXT_DOMAIN,
                            "Volume successfully snapshotted, but device links "
                            "were not created"));
                        zfs_close(zhp);
                        return (-1);
                }
        }

        if (ret != 0)
                (void) zfs_standard_error(hdl, errno, errbuf);

        zfs_close(zhp);

        return (ret);
}

/*
 * Destroy any more recent snapshots.  We invoke this callback on any dependents
 * of the snapshot first.  If the 'cb_dependent' member is non-zero, then this
 * is a dependent and we should just destroy it without checking the transaction
 * group.
 */
typedef struct rollback_data {
        const char      *cb_target;             /* the snapshot */
        uint64_t        cb_create;              /* creation time reference */
        boolean_t       cb_error;
        boolean_t       cb_dependent;
        boolean_t       cb_force;
} rollback_data_t;

static int
rollback_destroy(zfs_handle_t *zhp, void *data)
{
        rollback_data_t *cbp = data;

        if (!cbp->cb_dependent) {
                if (strcmp(zhp->zfs_name, cbp->cb_target) != 0 &&
                    zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT &&
                    zfs_prop_get_int(zhp, ZFS_PROP_CREATETXG) >
                    cbp->cb_create) {
                        char *logstr;

                        cbp->cb_dependent = B_TRUE;
                        cbp->cb_error |= zfs_iter_dependents(zhp, B_FALSE,
                            rollback_destroy, cbp);
                        cbp->cb_dependent = B_FALSE;

                        logstr = zhp->zfs_hdl->libzfs_log_str;
                        zhp->zfs_hdl->libzfs_log_str = NULL;
                        cbp->cb_error |= zfs_destroy(zhp);
                        zhp->zfs_hdl->libzfs_log_str = logstr;
                }
        } else {
                /* We must destroy this clone; first unmount it */
                prop_changelist_t *clp;

                clp = changelist_gather(zhp, ZFS_PROP_NAME, 0,
                    cbp->cb_force ? MS_FORCE: 0);
                if (clp == NULL || changelist_prefix(clp) != 0) {
                        cbp->cb_error = B_TRUE;
                        zfs_close(zhp);
                        return (0);
                }
                if (zfs_destroy(zhp) != 0)
                        cbp->cb_error = B_TRUE;
                else
                        changelist_remove(clp, zhp->zfs_name);
                (void) changelist_postfix(clp);
                changelist_free(clp);
        }

        zfs_close(zhp);
        return (0);
}

/*
 * Given a dataset, rollback to a specific snapshot, discarding any
 * data changes since then and making it the active dataset.
 *
 * Any snapshots more recent than the target are destroyed, along with
 * their dependents.
 */
int
zfs_rollback(zfs_handle_t *zhp, zfs_handle_t *snap, boolean_t force)
{
        rollback_data_t cb = { 0 };
        int err;
        zfs_cmd_t zc = { 0 };
        boolean_t restore_resv = 0;
        uint64_t old_volsize, new_volsize;
        zfs_prop_t resv_prop;

        assert(zhp->zfs_type == ZFS_TYPE_FILESYSTEM ||
            zhp->zfs_type == ZFS_TYPE_VOLUME);

        /*
         * Destroy all recent snapshots and its dependends.
         */
        cb.cb_force = force;
        cb.cb_target = snap->zfs_name;
        cb.cb_create = zfs_prop_get_int(snap, ZFS_PROP_CREATETXG);
        (void) zfs_iter_children(zhp, rollback_destroy, &cb);

        if (cb.cb_error)
                return (-1);

        /*
         * Now that we have verified that the snapshot is the latest,
         * rollback to the given snapshot.
         */

        if (zhp->zfs_type == ZFS_TYPE_VOLUME) {
                if (zvol_remove_link(zhp->zfs_hdl, zhp->zfs_name) != 0)
                        return (-1);
                if (zfs_which_resv_prop(zhp, &resv_prop) < 0)
                        return (-1);
                old_volsize = zfs_prop_get_int(zhp, ZFS_PROP_VOLSIZE);
                restore_resv =
                    (old_volsize == zfs_prop_get_int(zhp, resv_prop));
        }

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

        if (ZFS_IS_VOLUME(zhp))
                zc.zc_objset_type = DMU_OST_ZVOL;
        else
                zc.zc_objset_type = DMU_OST_ZFS;

        /*
         * We rely on zfs_iter_children() to verify that there are no
         * newer snapshots for the given dataset.  Therefore, we can
         * simply pass the name on to the ioctl() call.  There is still
         * an unlikely race condition where the user has taken a
         * snapshot since we verified that this was the most recent.
         *
         */
        if ((err = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_ROLLBACK, &zc)) != 0) {
                (void) zfs_standard_error_fmt(zhp->zfs_hdl, errno,
                    dgettext(TEXT_DOMAIN, "cannot rollback '%s'"),
                    zhp->zfs_name);
                return (err);
        }

        /*
         * For volumes, if the pre-rollback volsize matched the pre-
         * rollback reservation and the volsize has changed then set
         * the reservation property to the post-rollback volsize.
         * Make a new handle since the rollback closed the dataset.
         */
        if ((zhp->zfs_type == ZFS_TYPE_VOLUME) &&
            (zhp = make_dataset_handle(zhp->zfs_hdl, zhp->zfs_name))) {
                if (err = zvol_create_link(zhp->zfs_hdl, zhp->zfs_name)) {
                        zfs_close(zhp);
                        return (err);
                }
                if (restore_resv) {
                        new_volsize = zfs_prop_get_int(zhp, ZFS_PROP_VOLSIZE);
                        if (old_volsize != new_volsize)
                                err = zfs_prop_set_int(zhp, resv_prop,
                                    new_volsize);
                }
                zfs_close(zhp);
        }
        return (err);
}

/*
 * Iterate over all dependents for a given dataset.  This includes both
 * hierarchical dependents (children) and data dependents (snapshots and
 * clones).  The bulk of the processing occurs in get_dependents() in
 * libzfs_graph.c.
 */
int
zfs_iter_dependents(zfs_handle_t *zhp, boolean_t allowrecursion,
    zfs_iter_f func, void *data)
{
        char **dependents;
        size_t count;
        int i;
        zfs_handle_t *child;
        int ret = 0;

        if (get_dependents(zhp->zfs_hdl, allowrecursion, zhp->zfs_name,
            &dependents, &count) != 0)
                return (-1);

        for (i = 0; i < count; i++) {
                if ((child = make_dataset_handle(zhp->zfs_hdl,
                    dependents[i])) == NULL)
                        continue;

                if ((ret = func(child, data)) != 0)
                        break;
        }

        for (i = 0; i < count; i++)
                free(dependents[i]);
        free(dependents);

        return (ret);
}

/*
 * Renames the given dataset.
 */
int
zfs_rename(zfs_handle_t *zhp, const char *target, boolean_t recursive)
{
        int ret;
        zfs_cmd_t zc = { 0 };
        char *delim;
        prop_changelist_t *cl = NULL;
        zfs_handle_t *zhrp = NULL;
        char *parentname = NULL;
        char parent[ZFS_MAXNAMELEN];
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        char errbuf[1024];

        /* if we have the same exact name, just return success */
        if (strcmp(zhp->zfs_name, target) == 0)
                return (0);

        (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
            "cannot rename to '%s'"), target);

        /*
         * Make sure the target name is valid
         */
        if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) {
                if ((strchr(target, '@') == NULL) ||
                    *target == '@') {
                        /*
                         * Snapshot target name is abbreviated,
                         * reconstruct full dataset name
                         */
                        (void) strlcpy(parent, zhp->zfs_name,
                            sizeof (parent));
                        delim = strchr(parent, '@');
                        if (strchr(target, '@') == NULL)
                                *(++delim) = '\0';
                        else
                                *delim = '\0';
                        (void) strlcat(parent, target, sizeof (parent));
                        target = parent;
                } else {
                        /*
                         * Make sure we're renaming within the same dataset.
                         */
                        delim = strchr(target, '@');
                        if (strncmp(zhp->zfs_name, target, delim - target)
                            != 0 || zhp->zfs_name[delim - target] != '@') {
                                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                                    "snapshots must be part of same "
                                    "dataset"));
                                return (zfs_error(hdl, EZFS_CROSSTARGET,
                                    errbuf));
                        }
                }
                if (!zfs_validate_name(hdl, target, zhp->zfs_type, B_TRUE))
                        return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
        } else {
                if (recursive) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "recursive rename must be a snapshot"));
                        return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
                }

                if (!zfs_validate_name(hdl, target, zhp->zfs_type, B_TRUE))
                        return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
                uint64_t unused;

                /* validate parents */
                if (check_parents(hdl, target, &unused, B_FALSE, NULL) != 0)
                        return (-1);

                (void) parent_name(target, parent, sizeof (parent));

                /* make sure we're in the same pool */
                verify((delim = strchr(target, '/')) != NULL);
                if (strncmp(zhp->zfs_name, target, delim - target) != 0 ||
                    zhp->zfs_name[delim - target] != '/') {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "datasets must be within same pool"));
                        return (zfs_error(hdl, EZFS_CROSSTARGET, errbuf));
                }

                /* new name cannot be a child of the current dataset name */
                if (strncmp(parent, zhp->zfs_name,
                    strlen(zhp->zfs_name)) == 0) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "New dataset name cannot be a descendent of "
                            "current dataset name"));
                        return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
                }
        }

        (void) snprintf(errbuf, sizeof (errbuf),
            dgettext(TEXT_DOMAIN, "cannot rename '%s'"), zhp->zfs_name);

        if (getzoneid() == GLOBAL_ZONEID &&
            zfs_prop_get_int(zhp, ZFS_PROP_ZONED)) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "dataset is used in a non-global zone"));
                return (zfs_error(hdl, EZFS_ZONED, errbuf));
        }

        if (recursive) {
                struct destroydata dd;

                parentname = zfs_strdup(zhp->zfs_hdl, zhp->zfs_name);
                if (parentname == NULL) {
                        ret = -1;
                        goto error;
                }
                delim = strchr(parentname, '@');
                *delim = '\0';
                zhrp = zfs_open(zhp->zfs_hdl, parentname, ZFS_TYPE_DATASET);
                if (zhrp == NULL) {
                        ret = -1;
                        goto error;
                }

                dd.snapname = delim + 1;
                dd.gotone = B_FALSE;
                dd.closezhp = B_TRUE;

                /* We remove any zvol links prior to renaming them */
                ret = zfs_iter_filesystems(zhrp, zfs_remove_link_cb, &dd);
                if (ret) {
                        goto error;
                }
        } else {
                if ((cl = changelist_gather(zhp, ZFS_PROP_NAME, 0, 0)) == NULL)
                        return (-1);

                if (changelist_haszonedchild(cl)) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "child dataset with inherited mountpoint is used "
                            "in a non-global zone"));
                        (void) zfs_error(hdl, EZFS_ZONED, errbuf);
                        goto error;
                }

                if ((ret = changelist_prefix(cl)) != 0)
                        goto error;
        }

        if (ZFS_IS_VOLUME(zhp))
                zc.zc_objset_type = DMU_OST_ZVOL;
        else
                zc.zc_objset_type = DMU_OST_ZFS;

        (void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
        (void) strlcpy(zc.zc_value, target, sizeof (zc.zc_value));

        zc.zc_cookie = recursive;

        if ((ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_RENAME, &zc)) != 0) {
                /*
                 * if it was recursive, the one that actually failed will
                 * be in zc.zc_name
                 */
                (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
                    "cannot rename '%s'"), zc.zc_name);

                if (recursive && errno == EEXIST) {
                        zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                            "a child dataset already has a snapshot "
                            "with the new name"));
                        (void) zfs_error(hdl, EZFS_EXISTS, errbuf);
                } else {
                        (void) zfs_standard_error(zhp->zfs_hdl, errno, errbuf);
                }

                /*
                 * On failure, we still want to remount any filesystems that
                 * were previously mounted, so we don't alter the system state.
                 */
                if (recursive) {
                        struct createdata cd;

                        /* only create links for datasets that had existed */
                        cd.cd_snapname = delim + 1;
                        cd.cd_ifexists = B_TRUE;
                        (void) zfs_iter_filesystems(zhrp, zfs_create_link_cb,
                            &cd);
                } else {
                        (void) changelist_postfix(cl);
                }
        } else {
                if (recursive) {
                        struct createdata cd;

                        /* only create links for datasets that had existed */
                        cd.cd_snapname = strchr(target, '@') + 1;
                        cd.cd_ifexists = B_TRUE;
                        ret = zfs_iter_filesystems(zhrp, zfs_create_link_cb,
                            &cd);
                } else {
                        changelist_rename(cl, zfs_get_name(zhp), target);
                        ret = changelist_postfix(cl);
                }
        }

error:
        if (parentname) {
                free(parentname);
        }
        if (zhrp) {
                zfs_close(zhrp);
        }
        if (cl) {
                changelist_free(cl);
        }
        return (ret);
}

/*
 * Given a zvol dataset, issue the ioctl to create the appropriate minor node,
 * poke devfsadm to create the /dev link, and then wait for the link to appear.
 */
int
zvol_create_link(libzfs_handle_t *hdl, const char *dataset)
{
        return (zvol_create_link_common(hdl, dataset, B_FALSE));
}

static int
zvol_create_link_common(libzfs_handle_t *hdl, const char *dataset, int ifexists)
{
        zfs_cmd_t zc = { 0 };
        di_devlink_handle_t dhdl;
        priv_set_t *priv_effective;
        int privileged;

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

        /*
         * Issue the appropriate ioctl.
         */
        if (ioctl(hdl->libzfs_fd, ZFS_IOC_CREATE_MINOR, &zc) != 0) {
                switch (errno) {
                case EEXIST:
                        /*
                         * Silently ignore the case where the link already
                         * exists.  This allows 'zfs volinit' to be run multiple
                         * times without errors.
                         */
                        return (0);

                case ENOENT:
                        /*
                         * Dataset does not exist in the kernel.  If we
                         * don't care (see zfs_rename), then ignore the
                         * error quietly.
                         */
                        if (ifexists) {
                                return (0);
                        }

                        /* FALLTHROUGH */

                default:
                        return (zfs_standard_error_fmt(hdl, errno,
                            dgettext(TEXT_DOMAIN, "cannot create device links "
                            "for '%s'"), dataset));
                }
        }

        /*
         * If privileged call devfsadm and wait for the links to
         * magically appear.
         * Otherwise, print out an informational message.
         */

        priv_effective = priv_allocset();
        (void) getppriv(PRIV_EFFECTIVE, priv_effective);
        privileged = (priv_isfullset(priv_effective) == B_TRUE);
        priv_freeset(priv_effective);

        if (privileged) {
                if ((dhdl = di_devlink_init(ZFS_DRIVER,
                    DI_MAKE_LINK)) == NULL) {
                        zfs_error_aux(hdl, strerror(errno));
                        (void) zfs_error_fmt(hdl, errno,
                            dgettext(TEXT_DOMAIN, "cannot create device links "
                            "for '%s'"), dataset);
                        (void) ioctl(hdl->libzfs_fd, ZFS_IOC_REMOVE_MINOR, &zc);
                        return (-1);
                } else {
                        (void) di_devlink_fini(&dhdl);
                }
        } else {
                char pathname[MAXPATHLEN];
                struct stat64 statbuf;
                int i;

#define MAX_WAIT        10

                /*
                 * This is the poor mans way of waiting for the link
                 * to show up.  If after 10 seconds we still don't
                 * have it, then print out a message.
                 */
                (void) snprintf(pathname, sizeof (pathname), "/dev/zvol/dsk/%s",
                    dataset);

                for (i = 0; i != MAX_WAIT; i++) {
                        if (stat64(pathname, &statbuf) == 0)
                                break;
                        (void) sleep(1);
                }
                if (i == MAX_WAIT)
                        (void) printf(gettext("%s may not be immediately "
                            "available\n"), pathname);
        }

        return (0);
}

/*
 * Remove a minor node for the given zvol and the associated /dev links.
 */
int
zvol_remove_link(libzfs_handle_t *hdl, const char *dataset)
{
        zfs_cmd_t zc = { 0 };

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

        if (ioctl(hdl->libzfs_fd, ZFS_IOC_REMOVE_MINOR, &zc) != 0) {
                switch (errno) {
                case ENXIO:
                        /*
                         * Silently ignore the case where the link no longer
                         * exists, so that 'zfs volfini' can be run multiple
                         * times without errors.
                         */
                        return (0);

                default:
                        return (zfs_standard_error_fmt(hdl, errno,
                            dgettext(TEXT_DOMAIN, "cannot remove device "
                            "links for '%s'"), dataset));
                }
        }

        return (0);
}

nvlist_t *
zfs_get_user_props(zfs_handle_t *zhp)
{
        return (zhp->zfs_user_props);
}

/*
 * This function is used by 'zfs list' to determine the exact set of columns to
 * display, and their maximum widths.  This does two main things:
 *
 *      - If this is a list of all properties, then expand the list to include
 *        all native properties, and set a flag so that for each dataset we look
 *        for new unique user properties and add them to the list.
 *
 *      - For non fixed-width properties, keep track of the maximum width seen
 *        so that we can size the column appropriately.
 */
int
zfs_expand_proplist(zfs_handle_t *zhp, zprop_list_t **plp)
{
        libzfs_handle_t *hdl = zhp->zfs_hdl;
        zprop_list_t *entry;
        zprop_list_t **last, **start;
        nvlist_t *userprops, *propval;
        nvpair_t *elem;
        char *strval;
        char buf[ZFS_MAXPROPLEN];

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

        userprops = zfs_get_user_props(zhp);

        entry = *plp;
        if (entry->pl_all && nvlist_next_nvpair(userprops, NULL) != NULL) {
                /*
                 * Go through and add any user properties as necessary.  We
                 * start by incrementing our list pointer to the first
                 * non-native property.
                 */
                start = plp;
                while (*start != NULL) {
                        if ((*start)->pl_prop == ZPROP_INVAL)
                                break;
                        start = &(*start)->pl_next;
                }

                elem = NULL;
                while ((elem = nvlist_next_nvpair(userprops, elem)) != NULL) {
                        /*
                         * See if we've already found this property in our list.
                         */
                        for (last = start; *last != NULL;
                            last = &(*last)->pl_next) {
                                if (strcmp((*last)->pl_user_prop,
                                    nvpair_name(elem)) == 0)
                                        break;
                        }

                        if (*last == NULL) {
                                if ((entry = zfs_alloc(hdl,
                                    sizeof (zprop_list_t))) == NULL ||
                                    ((entry->pl_user_prop = zfs_strdup(hdl,
                                    nvpair_name(elem)))) == NULL) {
                                        free(entry);
                                        return (-1);
                                }

                                entry->pl_prop = ZPROP_INVAL;
                                entry->pl_width = strlen(nvpair_name(elem));
                                entry->pl_all = B_TRUE;
                                *last = entry;
                        }
                }
        }

        /*
         * Now go through and check the width of any non-fixed columns
         */
        for (entry = *plp; entry != NULL; entry = entry->pl_next) {
                if (entry->pl_fixed)
                        continue;

                if (entry->pl_prop != ZPROP_INVAL) {
                        if (zfs_prop_get(zhp, entry->pl_prop,
                            buf, sizeof (buf), NULL, NULL, 0, B_FALSE) == 0) {
                                if (strlen(buf) > entry->pl_width)
                                        entry->pl_width = strlen(buf);
                        }
                } else if (nvlist_lookup_nvlist(userprops,
                    entry->pl_user_prop, &propval)  == 0) {
                        verify(nvlist_lookup_string(propval,
                            ZPROP_VALUE, &strval) == 0);
                        if (strlen(strval) > entry->pl_width)
                                entry->pl_width = strlen(strval);
                }
        }

        return (0);
}

int
zfs_iscsi_perm_check(libzfs_handle_t *hdl, char *dataset, ucred_t *cred)
{
        zfs_cmd_t zc = { 0 };
        nvlist_t *nvp;
        gid_t gid;
        uid_t uid;
        const gid_t *groups;
        int group_cnt;
        int error;

        if (nvlist_alloc(&nvp, NV_UNIQUE_NAME, 0) != 0)
                return (no_memory(hdl));

        uid = ucred_geteuid(cred);
        gid = ucred_getegid(cred);
        group_cnt = ucred_getgroups(cred, &groups);

        if (uid == (uid_t)-1 || gid == (uid_t)-1 || group_cnt == (uid_t)-1)
                return (1);

        if (nvlist_add_uint32(nvp, ZFS_DELEG_PERM_UID, uid) != 0) {
                nvlist_free(nvp);
                return (1);
        }

        if (nvlist_add_uint32(nvp, ZFS_DELEG_PERM_GID, gid) != 0) {
                nvlist_free(nvp);
                return (1);
        }

        if (nvlist_add_uint32_array(nvp,
            ZFS_DELEG_PERM_GROUPS, (uint32_t *)groups, group_cnt) != 0) {
                nvlist_free(nvp);
                return (1);
        }
        (void) strlcpy(zc.zc_name, dataset, sizeof (zc.zc_name));

        if (zcmd_write_src_nvlist(hdl, &zc, nvp))
                return (-1);

        error = ioctl(hdl->libzfs_fd, ZFS_IOC_ISCSI_PERM_CHECK, &zc);
        nvlist_free(nvp);
        return (error);
}

int
zfs_deleg_share_nfs(libzfs_handle_t *hdl, char *dataset, char *path,
    void *export, void *sharetab, int sharemax, zfs_share_op_t operation)
{
        zfs_cmd_t zc = { 0 };
        int error;

        (void) strlcpy(zc.zc_name, dataset, sizeof (zc.zc_name));
        (void) strlcpy(zc.zc_value, path, sizeof (zc.zc_value));
        zc.zc_share.z_sharedata = (uint64_t)(uintptr_t)sharetab;
        zc.zc_share.z_exportdata = (uint64_t)(uintptr_t)export;
        zc.zc_share.z_sharetype = operation;
        zc.zc_share.z_sharemax = sharemax;

        error = ioctl(hdl->libzfs_fd, ZFS_IOC_SHARE, &zc);
        return (error);
}