Fix Coverity defects

[zfs] / module / zfs / zfs_ioctl.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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Portions Copyright 2011 Martin Matuska
 * Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved.
 * Portions Copyright 2012 Pawel Jakub Dawidek <pawel@dawidek.net>
 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
 * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2014, Joyent, Inc. All rights reserved.
 * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
 * Copyright (c) 2013 Steven Hartland. All rights reserved.
 * Copyright (c) 2016 Actifio, Inc. All rights reserved.
 */

/*
 * ZFS ioctls.
 *
 * This file handles the ioctls to /dev/zfs, used for configuring ZFS storage
 * pools and filesystems, e.g. with /sbin/zfs and /sbin/zpool.
 *
 * There are two ways that we handle ioctls: the legacy way where almost
 * all of the logic is in the ioctl callback, and the new way where most
 * of the marshalling is handled in the common entry point, zfsdev_ioctl().
 *
 * Non-legacy ioctls should be registered by calling
 * zfs_ioctl_register() from zfs_ioctl_init().  The ioctl is invoked
 * from userland by lzc_ioctl().
 *
 * The registration arguments are as follows:
 *
 * const char *name
 *   The name of the ioctl.  This is used for history logging.  If the
 *   ioctl returns successfully (the callback returns 0), and allow_log
 *   is true, then a history log entry will be recorded with the input &
 *   output nvlists.  The log entry can be printed with "zpool history -i".
 *
 * zfs_ioc_t ioc
 *   The ioctl request number, which userland will pass to ioctl(2).
 *   The ioctl numbers can change from release to release, because
 *   the caller (libzfs) must be matched to the kernel.
 *
 * zfs_secpolicy_func_t *secpolicy
 *   This function will be called before the zfs_ioc_func_t, to
 *   determine if this operation is permitted.  It should return EPERM
 *   on failure, and 0 on success.  Checks include determining if the
 *   dataset is visible in this zone, and if the user has either all
 *   zfs privileges in the zone (SYS_MOUNT), or has been granted permission
 *   to do this operation on this dataset with "zfs allow".
 *
 * zfs_ioc_namecheck_t namecheck
 *   This specifies what to expect in the zfs_cmd_t:zc_name -- a pool
 *   name, a dataset name, or nothing.  If the name is not well-formed,
 *   the ioctl will fail and the callback will not be called.
 *   Therefore, the callback can assume that the name is well-formed
 *   (e.g. is null-terminated, doesn't have more than one '@' character,
 *   doesn't have invalid characters).
 *
 * zfs_ioc_poolcheck_t pool_check
 *   This specifies requirements on the pool state.  If the pool does
 *   not meet them (is suspended or is readonly), the ioctl will fail
 *   and the callback will not be called.  If any checks are specified
 *   (i.e. it is not POOL_CHECK_NONE), namecheck must not be NO_NAME.
 *   Multiple checks can be or-ed together (e.g. POOL_CHECK_SUSPENDED |
 *   POOL_CHECK_READONLY).
 *
 * boolean_t smush_outnvlist
 *   If smush_outnvlist is true, then the output is presumed to be a
 *   list of errors, and it will be "smushed" down to fit into the
 *   caller's buffer, by removing some entries and replacing them with a
 *   single "N_MORE_ERRORS" entry indicating how many were removed.  See
 *   nvlist_smush() for details.  If smush_outnvlist is false, and the
 *   outnvlist does not fit into the userland-provided buffer, then the
 *   ioctl will fail with ENOMEM.
 *
 * zfs_ioc_func_t *func
 *   The callback function that will perform the operation.
 *
 *   The callback should return 0 on success, or an error number on
 *   failure.  If the function fails, the userland ioctl will return -1,
 *   and errno will be set to the callback's return value.  The callback
 *   will be called with the following arguments:
 *
 *   const char *name
 *     The name of the pool or dataset to operate on, from
 *     zfs_cmd_t:zc_name.  The 'namecheck' argument specifies the
 *     expected type (pool, dataset, or none).
 *
 *   nvlist_t *innvl
 *     The input nvlist, deserialized from zfs_cmd_t:zc_nvlist_src.  Or
 *     NULL if no input nvlist was provided.  Changes to this nvlist are
 *     ignored.  If the input nvlist could not be deserialized, the
 *     ioctl will fail and the callback will not be called.
 *
 *   nvlist_t *outnvl
 *     The output nvlist, initially empty.  The callback can fill it in,
 *     and it will be returned to userland by serializing it into
 *     zfs_cmd_t:zc_nvlist_dst.  If it is non-empty, and serialization
 *     fails (e.g. because the caller didn't supply a large enough
 *     buffer), then the overall ioctl will fail.  See the
 *     'smush_nvlist' argument above for additional behaviors.
 *
 *     There are two typical uses of the output nvlist:
 *       - To return state, e.g. property values.  In this case,
 *         smush_outnvlist should be false.  If the buffer was not large
 *         enough, the caller will reallocate a larger buffer and try
 *         the ioctl again.
 *
 *       - To return multiple errors from an ioctl which makes on-disk
 *         changes.  In this case, smush_outnvlist should be true.
 *         Ioctls which make on-disk modifications should generally not
 *         use the outnvl if they succeed, because the caller can not
 *         distinguish between the operation failing, and
 *         deserialization failing.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/uio.h>
#include <sys/buf.h>
#include <sys/modctl.h>
#include <sys/open.h>
#include <sys/file.h>
#include <sys/kmem.h>
#include <sys/conf.h>
#include <sys/cmn_err.h>
#include <sys/stat.h>
#include <sys/zfs_ioctl.h>
#include <sys/zfs_vfsops.h>
#include <sys/zfs_znode.h>
#include <sys/zap.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/vdev.h>
#include <sys/priv_impl.h>
#include <sys/dmu.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_prop.h>
#include <sys/dsl_deleg.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/sunldi.h>
#include <sys/policy.h>
#include <sys/zone.h>
#include <sys/nvpair.h>
#include <sys/pathname.h>
#include <sys/mount.h>
#include <sys/sdt.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_ctldir.h>
#include <sys/zfs_dir.h>
#include <sys/zfs_onexit.h>
#include <sys/zvol.h>
#include <sys/dsl_scan.h>
#include <sharefs/share.h>
#include <sys/fm/util.h>

#include <sys/dmu_send.h>
#include <sys/dsl_destroy.h>
#include <sys/dsl_bookmark.h>
#include <sys/dsl_userhold.h>
#include <sys/zfeature.h>

#include <linux/miscdevice.h>
#include <linux/slab.h>

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

/*
 * Limit maximum nvlist size.  We don't want users passing in insane values
 * for zc->zc_nvlist_src_size, since we will need to allocate that much memory.
 */
#define MAX_NVLIST_SRC_SIZE     KMALLOC_MAX_SIZE

kmutex_t zfsdev_state_lock;
zfsdev_state_t *zfsdev_state_list;

extern void zfs_init(void);
extern void zfs_fini(void);

uint_t zfs_fsyncer_key;
extern uint_t rrw_tsd_key;
static uint_t zfs_allow_log_key;

typedef int zfs_ioc_legacy_func_t(zfs_cmd_t *);
typedef int zfs_ioc_func_t(const char *, nvlist_t *, nvlist_t *);
typedef int zfs_secpolicy_func_t(zfs_cmd_t *, nvlist_t *, cred_t *);

typedef enum {
        NO_NAME,
        POOL_NAME,
        DATASET_NAME
} zfs_ioc_namecheck_t;

typedef enum {
        POOL_CHECK_NONE         = 1 << 0,
        POOL_CHECK_SUSPENDED    = 1 << 1,
        POOL_CHECK_READONLY     = 1 << 2,
} zfs_ioc_poolcheck_t;

typedef struct zfs_ioc_vec {
        zfs_ioc_legacy_func_t   *zvec_legacy_func;
        zfs_ioc_func_t          *zvec_func;
        zfs_secpolicy_func_t    *zvec_secpolicy;
        zfs_ioc_namecheck_t     zvec_namecheck;
        boolean_t               zvec_allow_log;
        zfs_ioc_poolcheck_t     zvec_pool_check;
        boolean_t               zvec_smush_outnvlist;
        const char              *zvec_name;
} zfs_ioc_vec_t;

/* This array is indexed by zfs_userquota_prop_t */
static const char *userquota_perms[] = {
        ZFS_DELEG_PERM_USERUSED,
        ZFS_DELEG_PERM_USERQUOTA,
        ZFS_DELEG_PERM_GROUPUSED,
        ZFS_DELEG_PERM_GROUPQUOTA,
};

static int zfs_ioc_userspace_upgrade(zfs_cmd_t *zc);
static int zfs_check_settable(const char *name, nvpair_t *property,
    cred_t *cr);
static int zfs_check_clearable(char *dataset, nvlist_t *props,
    nvlist_t **errors);
static int zfs_fill_zplprops_root(uint64_t, nvlist_t *, nvlist_t *,
    boolean_t *);
int zfs_set_prop_nvlist(const char *, zprop_source_t, nvlist_t *, nvlist_t *);
static int get_nvlist(uint64_t nvl, uint64_t size, int iflag, nvlist_t **nvp);

static void
history_str_free(char *buf)
{
        kmem_free(buf, HIS_MAX_RECORD_LEN);
}

static char *
history_str_get(zfs_cmd_t *zc)
{
        char *buf;

        if (zc->zc_history == 0)
                return (NULL);

        buf = kmem_alloc(HIS_MAX_RECORD_LEN, KM_SLEEP);
        if (copyinstr((void *)(uintptr_t)zc->zc_history,
            buf, HIS_MAX_RECORD_LEN, NULL) != 0) {
                history_str_free(buf);
                return (NULL);
        }

        buf[HIS_MAX_RECORD_LEN -1] = '\0';

        return (buf);
}

/*
 * Check to see if the named dataset is currently defined as bootable
 */
static boolean_t
zfs_is_bootfs(const char *name)
{
        objset_t *os;

        if (dmu_objset_hold(name, FTAG, &os) == 0) {
                boolean_t ret;
                ret = (dmu_objset_id(os) == spa_bootfs(dmu_objset_spa(os)));
                dmu_objset_rele(os, FTAG);
                return (ret);
        }
        return (B_FALSE);
}

/*
 * Return non-zero if the spa version is less than requested version.
 */
static int
zfs_earlier_version(const char *name, int version)
{
        spa_t *spa;

        if (spa_open(name, &spa, FTAG) == 0) {
                if (spa_version(spa) < version) {
                        spa_close(spa, FTAG);
                        return (1);
                }
                spa_close(spa, FTAG);
        }
        return (0);
}

/*
 * Return TRUE if the ZPL version is less than requested version.
 */
static boolean_t
zpl_earlier_version(const char *name, int version)
{
        objset_t *os;
        boolean_t rc = B_TRUE;

        if (dmu_objset_hold(name, FTAG, &os) == 0) {
                uint64_t zplversion;

                if (dmu_objset_type(os) != DMU_OST_ZFS) {
                        dmu_objset_rele(os, FTAG);
                        return (B_TRUE);
                }
                /* XXX reading from non-owned objset */
                if (zfs_get_zplprop(os, ZFS_PROP_VERSION, &zplversion) == 0)
                        rc = zplversion < version;
                dmu_objset_rele(os, FTAG);
        }
        return (rc);
}

static void
zfs_log_history(zfs_cmd_t *zc)
{
        spa_t *spa;
        char *buf;

        if ((buf = history_str_get(zc)) == NULL)
                return;

        if (spa_open(zc->zc_name, &spa, FTAG) == 0) {
                if (spa_version(spa) >= SPA_VERSION_ZPOOL_HISTORY)
                        (void) spa_history_log(spa, buf);
                spa_close(spa, FTAG);
        }
        history_str_free(buf);
}

/*
 * Policy for top-level read operations (list pools).  Requires no privileges,
 * and can be used in the local zone, as there is no associated dataset.
 */
/* ARGSUSED */
static int
zfs_secpolicy_none(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (0);
}

/*
 * Policy for dataset read operations (list children, get statistics).  Requires
 * no privileges, but must be visible in the local zone.
 */
/* ARGSUSED */
static int
zfs_secpolicy_read(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        if (INGLOBALZONE(curproc) ||
            zone_dataset_visible(zc->zc_name, NULL))
                return (0);

        return (SET_ERROR(ENOENT));
}

static int
zfs_dozonecheck_impl(const char *dataset, uint64_t zoned, cred_t *cr)
{
        int writable = 1;

        /*
         * The dataset must be visible by this zone -- check this first
         * so they don't see EPERM on something they shouldn't know about.
         */
        if (!INGLOBALZONE(curproc) &&
            !zone_dataset_visible(dataset, &writable))
                return (SET_ERROR(ENOENT));

        if (INGLOBALZONE(curproc)) {
                /*
                 * If the fs is zoned, only root can access it from the
                 * global zone.
                 */
                if (secpolicy_zfs(cr) && zoned)
                        return (SET_ERROR(EPERM));
        } else {
                /*
                 * If we are in a local zone, the 'zoned' property must be set.
                 */
                if (!zoned)
                        return (SET_ERROR(EPERM));

                /* must be writable by this zone */
                if (!writable)
                        return (SET_ERROR(EPERM));
        }
        return (0);
}

static int
zfs_dozonecheck(const char *dataset, cred_t *cr)
{
        uint64_t zoned;

        if (dsl_prop_get_integer(dataset, "zoned", &zoned, NULL))
                return (SET_ERROR(ENOENT));

        return (zfs_dozonecheck_impl(dataset, zoned, cr));
}

static int
zfs_dozonecheck_ds(const char *dataset, dsl_dataset_t *ds, cred_t *cr)
{
        uint64_t zoned;

        if (dsl_prop_get_int_ds(ds, "zoned", &zoned))
                return (SET_ERROR(ENOENT));

        return (zfs_dozonecheck_impl(dataset, zoned, cr));
}

static int
zfs_secpolicy_write_perms_ds(const char *name, dsl_dataset_t *ds,
    const char *perm, cred_t *cr)
{
        int error;

        error = zfs_dozonecheck_ds(name, ds, cr);
        if (error == 0) {
                error = secpolicy_zfs(cr);
                if (error != 0)
                        error = dsl_deleg_access_impl(ds, perm, cr);
        }
        return (error);
}

static int
zfs_secpolicy_write_perms(const char *name, const char *perm, cred_t *cr)
{
        int error;
        dsl_dataset_t *ds;
        dsl_pool_t *dp;

        error = dsl_pool_hold(name, FTAG, &dp);
        if (error != 0)
                return (error);

        error = dsl_dataset_hold(dp, name, FTAG, &ds);
        if (error != 0) {
                dsl_pool_rele(dp, FTAG);
                return (error);
        }

        error = zfs_secpolicy_write_perms_ds(name, ds, perm, cr);

        dsl_dataset_rele(ds, FTAG);
        dsl_pool_rele(dp, FTAG);
        return (error);
}

/*
 * Policy for setting the security label property.
 *
 * Returns 0 for success, non-zero for access and other errors.
 */
static int
zfs_set_slabel_policy(const char *name, char *strval, cred_t *cr)
{
#ifdef HAVE_MLSLABEL
        char            ds_hexsl[MAXNAMELEN];
        bslabel_t       ds_sl, new_sl;
        boolean_t       new_default = FALSE;
        uint64_t        zoned;
        int             needed_priv = -1;
        int             error;

        /* First get the existing dataset label. */
        error = dsl_prop_get(name, zfs_prop_to_name(ZFS_PROP_MLSLABEL),
            1, sizeof (ds_hexsl), &ds_hexsl, NULL);
        if (error != 0)
                return (SET_ERROR(EPERM));

        if (strcasecmp(strval, ZFS_MLSLABEL_DEFAULT) == 0)
                new_default = TRUE;

        /* The label must be translatable */
        if (!new_default && (hexstr_to_label(strval, &new_sl) != 0))
                return (SET_ERROR(EINVAL));

        /*
         * In a non-global zone, disallow attempts to set a label that
         * doesn't match that of the zone; otherwise no other checks
         * are needed.
         */
        if (!INGLOBALZONE(curproc)) {
                if (new_default || !blequal(&new_sl, CR_SL(CRED())))
                        return (SET_ERROR(EPERM));
                return (0);
        }

        /*
         * For global-zone datasets (i.e., those whose zoned property is
         * "off", verify that the specified new label is valid for the
         * global zone.
         */
        if (dsl_prop_get_integer(name,
            zfs_prop_to_name(ZFS_PROP_ZONED), &zoned, NULL))
                return (SET_ERROR(EPERM));
        if (!zoned) {
                if (zfs_check_global_label(name, strval) != 0)
                        return (SET_ERROR(EPERM));
        }

        /*
         * If the existing dataset label is nondefault, check if the
         * dataset is mounted (label cannot be changed while mounted).
         * Get the zfs_sb_t; if there isn't one, then the dataset isn't
         * mounted (or isn't a dataset, doesn't exist, ...).
         */
        if (strcasecmp(ds_hexsl, ZFS_MLSLABEL_DEFAULT) != 0) {
                objset_t *os;
                static char *setsl_tag = "setsl_tag";

                /*
                 * Try to own the dataset; abort if there is any error,
                 * (e.g., already mounted, in use, or other error).
                 */
                error = dmu_objset_own(name, DMU_OST_ZFS, B_TRUE,
                    setsl_tag, &os);
                if (error != 0)
                        return (SET_ERROR(EPERM));

                dmu_objset_disown(os, setsl_tag);

                if (new_default) {
                        needed_priv = PRIV_FILE_DOWNGRADE_SL;
                        goto out_check;
                }

                if (hexstr_to_label(strval, &new_sl) != 0)
                        return (SET_ERROR(EPERM));

                if (blstrictdom(&ds_sl, &new_sl))
                        needed_priv = PRIV_FILE_DOWNGRADE_SL;
                else if (blstrictdom(&new_sl, &ds_sl))
                        needed_priv = PRIV_FILE_UPGRADE_SL;
        } else {
                /* dataset currently has a default label */
                if (!new_default)
                        needed_priv = PRIV_FILE_UPGRADE_SL;
        }

out_check:
        if (needed_priv != -1)
                return (PRIV_POLICY(cr, needed_priv, B_FALSE, EPERM, NULL));
        return (0);
#else
        return (ENOTSUP);
#endif /* HAVE_MLSLABEL */
}

static int
zfs_secpolicy_setprop(const char *dsname, zfs_prop_t prop, nvpair_t *propval,
    cred_t *cr)
{
        char *strval;

        /*
         * Check permissions for special properties.
         */
        switch (prop) {
        default:
                break;
        case ZFS_PROP_ZONED:
                /*
                 * Disallow setting of 'zoned' from within a local zone.
                 */
                if (!INGLOBALZONE(curproc))
                        return (SET_ERROR(EPERM));
                break;

        case ZFS_PROP_QUOTA:
        case ZFS_PROP_FILESYSTEM_LIMIT:
        case ZFS_PROP_SNAPSHOT_LIMIT:
                if (!INGLOBALZONE(curproc)) {
                        uint64_t zoned;
                        char setpoint[ZFS_MAX_DATASET_NAME_LEN];
                        /*
                         * Unprivileged users are allowed to modify the
                         * limit on things *under* (ie. contained by)
                         * the thing they own.
                         */
                        if (dsl_prop_get_integer(dsname, "zoned", &zoned,
                            setpoint))
                                return (SET_ERROR(EPERM));
                        if (!zoned || strlen(dsname) <= strlen(setpoint))
                                return (SET_ERROR(EPERM));
                }
                break;

        case ZFS_PROP_MLSLABEL:
                if (!is_system_labeled())
                        return (SET_ERROR(EPERM));

                if (nvpair_value_string(propval, &strval) == 0) {
                        int err;

                        err = zfs_set_slabel_policy(dsname, strval, CRED());
                        if (err != 0)
                                return (err);
                }
                break;
        }

        return (zfs_secpolicy_write_perms(dsname, zfs_prop_to_name(prop), cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_set_fsacl(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        int error;

        error = zfs_dozonecheck(zc->zc_name, cr);
        if (error != 0)
                return (error);

        /*
         * permission to set permissions will be evaluated later in
         * dsl_deleg_can_allow()
         */
        return (0);
}

/* ARGSUSED */
static int
zfs_secpolicy_rollback(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (zfs_secpolicy_write_perms(zc->zc_name,
            ZFS_DELEG_PERM_ROLLBACK, cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_send(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        dsl_pool_t *dp;
        dsl_dataset_t *ds;
        char *cp;
        int error;

        /*
         * Generate the current snapshot name from the given objsetid, then
         * use that name for the secpolicy/zone checks.
         */
        cp = strchr(zc->zc_name, '@');
        if (cp == NULL)
                return (SET_ERROR(EINVAL));
        error = dsl_pool_hold(zc->zc_name, FTAG, &dp);
        if (error != 0)
                return (error);

        error = dsl_dataset_hold_obj(dp, zc->zc_sendobj, FTAG, &ds);
        if (error != 0) {
                dsl_pool_rele(dp, FTAG);
                return (error);
        }

        dsl_dataset_name(ds, zc->zc_name);

        error = zfs_secpolicy_write_perms_ds(zc->zc_name, ds,
            ZFS_DELEG_PERM_SEND, cr);
        dsl_dataset_rele(ds, FTAG);
        dsl_pool_rele(dp, FTAG);

        return (error);
}

/* ARGSUSED */
static int
zfs_secpolicy_send_new(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (zfs_secpolicy_write_perms(zc->zc_name,
            ZFS_DELEG_PERM_SEND, cr));
}

#ifdef HAVE_SMB_SHARE
/* ARGSUSED */
static int
zfs_secpolicy_deleg_share(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        vnode_t *vp;
        int error;

        if ((error = lookupname(zc->zc_value, UIO_SYSSPACE,
            NO_FOLLOW, NULL, &vp)) != 0)
                return (error);

        /* Now make sure mntpnt and dataset are ZFS */

        if (vp->v_vfsp->vfs_fstype != zfsfstype ||
            (strcmp((char *)refstr_value(vp->v_vfsp->vfs_resource),
            zc->zc_name) != 0)) {
                VN_RELE(vp);
                return (SET_ERROR(EPERM));
        }

        VN_RELE(vp);
        return (dsl_deleg_access(zc->zc_name,
            ZFS_DELEG_PERM_SHARE, cr));
}
#endif /* HAVE_SMB_SHARE */

int
zfs_secpolicy_share(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
#ifdef HAVE_SMB_SHARE
        if (!INGLOBALZONE(curproc))
                return (SET_ERROR(EPERM));

        if (secpolicy_nfs(cr) == 0) {
                return (0);
        } else {
                return (zfs_secpolicy_deleg_share(zc, innvl, cr));
        }
#else
        return (SET_ERROR(ENOTSUP));
#endif /* HAVE_SMB_SHARE */
}

int
zfs_secpolicy_smb_acl(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
#ifdef HAVE_SMB_SHARE
        if (!INGLOBALZONE(curproc))
                return (SET_ERROR(EPERM));

        if (secpolicy_smb(cr) == 0) {
                return (0);
        } else {
                return (zfs_secpolicy_deleg_share(zc, innvl, cr));
        }
#else
        return (SET_ERROR(ENOTSUP));
#endif /* HAVE_SMB_SHARE */
}

static int
zfs_get_parent(const char *datasetname, char *parent, int parentsize)
{
        char *cp;

        /*
         * Remove the @bla or /bla from the end of the name to get the parent.
         */
        (void) strncpy(parent, datasetname, parentsize);
        cp = strrchr(parent, '@');
        if (cp != NULL) {
                cp[0] = '\0';
        } else {
                cp = strrchr(parent, '/');
                if (cp == NULL)
                        return (SET_ERROR(ENOENT));
                cp[0] = '\0';
        }

        return (0);
}

int
zfs_secpolicy_destroy_perms(const char *name, cred_t *cr)
{
        int error;

        if ((error = zfs_secpolicy_write_perms(name,
            ZFS_DELEG_PERM_MOUNT, cr)) != 0)
                return (error);

        return (zfs_secpolicy_write_perms(name, ZFS_DELEG_PERM_DESTROY, cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_destroy(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (zfs_secpolicy_destroy_perms(zc->zc_name, cr));
}

/*
 * Destroying snapshots with delegated permissions requires
 * descendant mount and destroy permissions.
 */
/* ARGSUSED */
static int
zfs_secpolicy_destroy_snaps(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        nvlist_t *snaps;
        nvpair_t *pair, *nextpair;
        int error = 0;

        if (nvlist_lookup_nvlist(innvl, "snaps", &snaps) != 0)
                return (SET_ERROR(EINVAL));
        for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
            pair = nextpair) {
                nextpair = nvlist_next_nvpair(snaps, pair);
                error = zfs_secpolicy_destroy_perms(nvpair_name(pair), cr);
                if (error == ENOENT) {
                        /*
                         * Ignore any snapshots that don't exist (we consider
                         * them "already destroyed").  Remove the name from the
                         * nvl here in case the snapshot is created between
                         * now and when we try to destroy it (in which case
                         * we don't want to destroy it since we haven't
                         * checked for permission).
                         */
                        fnvlist_remove_nvpair(snaps, pair);
                        error = 0;
                }
                if (error != 0)
                        break;
        }

        return (error);
}

int
zfs_secpolicy_rename_perms(const char *from, const char *to, cred_t *cr)
{
        char    parentname[ZFS_MAX_DATASET_NAME_LEN];
        int     error;

        if ((error = zfs_secpolicy_write_perms(from,
            ZFS_DELEG_PERM_RENAME, cr)) != 0)
                return (error);

        if ((error = zfs_secpolicy_write_perms(from,
            ZFS_DELEG_PERM_MOUNT, cr)) != 0)
                return (error);

        if ((error = zfs_get_parent(to, parentname,
            sizeof (parentname))) != 0)
                return (error);

        if ((error = zfs_secpolicy_write_perms(parentname,
            ZFS_DELEG_PERM_CREATE, cr)) != 0)
                return (error);

        if ((error = zfs_secpolicy_write_perms(parentname,
            ZFS_DELEG_PERM_MOUNT, cr)) != 0)
                return (error);

        return (error);
}

/* ARGSUSED */
static int
zfs_secpolicy_rename(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (zfs_secpolicy_rename_perms(zc->zc_name, zc->zc_value, cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_promote(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        dsl_pool_t *dp;
        dsl_dataset_t *clone;
        int error;

        error = zfs_secpolicy_write_perms(zc->zc_name,
            ZFS_DELEG_PERM_PROMOTE, cr);
        if (error != 0)
                return (error);

        error = dsl_pool_hold(zc->zc_name, FTAG, &dp);
        if (error != 0)
                return (error);

        error = dsl_dataset_hold(dp, zc->zc_name, FTAG, &clone);

        if (error == 0) {
                char parentname[ZFS_MAX_DATASET_NAME_LEN];
                dsl_dataset_t *origin = NULL;
                dsl_dir_t *dd;
                dd = clone->ds_dir;

                error = dsl_dataset_hold_obj(dd->dd_pool,
                    dsl_dir_phys(dd)->dd_origin_obj, FTAG, &origin);
                if (error != 0) {
                        dsl_dataset_rele(clone, FTAG);
                        dsl_pool_rele(dp, FTAG);
                        return (error);
                }

                error = zfs_secpolicy_write_perms_ds(zc->zc_name, clone,
                    ZFS_DELEG_PERM_MOUNT, cr);

                dsl_dataset_name(origin, parentname);
                if (error == 0) {
                        error = zfs_secpolicy_write_perms_ds(parentname, origin,
                            ZFS_DELEG_PERM_PROMOTE, cr);
                }
                dsl_dataset_rele(clone, FTAG);
                dsl_dataset_rele(origin, FTAG);
        }
        dsl_pool_rele(dp, FTAG);
        return (error);
}

/* ARGSUSED */
static int
zfs_secpolicy_recv(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        int error;

        if ((error = zfs_secpolicy_write_perms(zc->zc_name,
            ZFS_DELEG_PERM_RECEIVE, cr)) != 0)
                return (error);

        if ((error = zfs_secpolicy_write_perms(zc->zc_name,
            ZFS_DELEG_PERM_MOUNT, cr)) != 0)
                return (error);

        return (zfs_secpolicy_write_perms(zc->zc_name,
            ZFS_DELEG_PERM_CREATE, cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_recv_new(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (zfs_secpolicy_recv(zc, innvl, cr));
}

int
zfs_secpolicy_snapshot_perms(const char *name, cred_t *cr)
{
        return (zfs_secpolicy_write_perms(name,
            ZFS_DELEG_PERM_SNAPSHOT, cr));
}

/*
 * Check for permission to create each snapshot in the nvlist.
 */
/* ARGSUSED */
static int
zfs_secpolicy_snapshot(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        nvlist_t *snaps;
        int error = 0;
        nvpair_t *pair;

        if (nvlist_lookup_nvlist(innvl, "snaps", &snaps) != 0)
                return (SET_ERROR(EINVAL));
        for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
            pair = nvlist_next_nvpair(snaps, pair)) {
                char *name = nvpair_name(pair);
                char *atp = strchr(name, '@');

                if (atp == NULL) {
                        error = SET_ERROR(EINVAL);
                        break;
                }
                *atp = '\0';
                error = zfs_secpolicy_snapshot_perms(name, cr);
                *atp = '@';
                if (error != 0)
                        break;
        }
        return (error);
}

/*
 * Check for permission to create each snapshot in the nvlist.
 */
/* ARGSUSED */
static int
zfs_secpolicy_bookmark(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        int error = 0;
        nvpair_t *pair;

        for (pair = nvlist_next_nvpair(innvl, NULL);
            pair != NULL; pair = nvlist_next_nvpair(innvl, pair)) {
                char *name = nvpair_name(pair);
                char *hashp = strchr(name, '#');

                if (hashp == NULL) {
                        error = SET_ERROR(EINVAL);
                        break;
                }
                *hashp = '\0';
                error = zfs_secpolicy_write_perms(name,
                    ZFS_DELEG_PERM_BOOKMARK, cr);
                *hashp = '#';
                if (error != 0)
                        break;
        }
        return (error);
}

/* ARGSUSED */
static int
zfs_secpolicy_destroy_bookmarks(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        nvpair_t *pair, *nextpair;
        int error = 0;

        for (pair = nvlist_next_nvpair(innvl, NULL); pair != NULL;
            pair = nextpair) {
                char *name = nvpair_name(pair);
                char *hashp = strchr(name, '#');
                nextpair = nvlist_next_nvpair(innvl, pair);

                if (hashp == NULL) {
                        error = SET_ERROR(EINVAL);
                        break;
                }

                *hashp = '\0';
                error = zfs_secpolicy_write_perms(name,
                    ZFS_DELEG_PERM_DESTROY, cr);
                *hashp = '#';
                if (error == ENOENT) {
                        /*
                         * Ignore any filesystems that don't exist (we consider
                         * their bookmarks "already destroyed").  Remove
                         * the name from the nvl here in case the filesystem
                         * is created between now and when we try to destroy
                         * the bookmark (in which case we don't want to
                         * destroy it since we haven't checked for permission).
                         */
                        fnvlist_remove_nvpair(innvl, pair);
                        error = 0;
                }
                if (error != 0)
                        break;
        }

        return (error);
}

/* ARGSUSED */
static int
zfs_secpolicy_log_history(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        /*
         * Even root must have a proper TSD so that we know what pool
         * to log to.
         */
        if (tsd_get(zfs_allow_log_key) == NULL)
                return (SET_ERROR(EPERM));
        return (0);
}

static int
zfs_secpolicy_create_clone(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        char    parentname[ZFS_MAX_DATASET_NAME_LEN];
        int     error;
        char    *origin;

        if ((error = zfs_get_parent(zc->zc_name, parentname,
            sizeof (parentname))) != 0)
                return (error);

        if (nvlist_lookup_string(innvl, "origin", &origin) == 0 &&
            (error = zfs_secpolicy_write_perms(origin,
            ZFS_DELEG_PERM_CLONE, cr)) != 0)
                return (error);

        if ((error = zfs_secpolicy_write_perms(parentname,
            ZFS_DELEG_PERM_CREATE, cr)) != 0)
                return (error);

        return (zfs_secpolicy_write_perms(parentname,
            ZFS_DELEG_PERM_MOUNT, cr));
}

/*
 * Policy for pool operations - create/destroy pools, add vdevs, etc.  Requires
 * SYS_CONFIG privilege, which is not available in a local zone.
 */
/* ARGSUSED */
static int
zfs_secpolicy_config(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        if (secpolicy_sys_config(cr, B_FALSE) != 0)
                return (SET_ERROR(EPERM));

        return (0);
}

/*
 * Policy for object to name lookups.
 */
/* ARGSUSED */
static int
zfs_secpolicy_diff(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        int error;

        if ((error = secpolicy_sys_config(cr, B_FALSE)) == 0)
                return (0);

        error = zfs_secpolicy_write_perms(zc->zc_name, ZFS_DELEG_PERM_DIFF, cr);
        return (error);
}

/*
 * Policy for fault injection.  Requires all privileges.
 */
/* ARGSUSED */
static int
zfs_secpolicy_inject(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (secpolicy_zinject(cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_inherit_prop(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        zfs_prop_t prop = zfs_name_to_prop(zc->zc_value);

        if (prop == ZPROP_INVAL) {
                if (!zfs_prop_user(zc->zc_value))
                        return (SET_ERROR(EINVAL));
                return (zfs_secpolicy_write_perms(zc->zc_name,
                    ZFS_DELEG_PERM_USERPROP, cr));
        } else {
                return (zfs_secpolicy_setprop(zc->zc_name, prop,
                    NULL, cr));
        }
}

static int
zfs_secpolicy_userspace_one(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        int err = zfs_secpolicy_read(zc, innvl, cr);
        if (err)
                return (err);

        if (zc->zc_objset_type >= ZFS_NUM_USERQUOTA_PROPS)
                return (SET_ERROR(EINVAL));

        if (zc->zc_value[0] == 0) {
                /*
                 * They are asking about a posix uid/gid.  If it's
                 * themself, allow it.
                 */
                if (zc->zc_objset_type == ZFS_PROP_USERUSED ||
                    zc->zc_objset_type == ZFS_PROP_USERQUOTA) {
                        if (zc->zc_guid == crgetuid(cr))
                                return (0);
                } else {
                        if (groupmember(zc->zc_guid, cr))
                                return (0);
                }
        }

        return (zfs_secpolicy_write_perms(zc->zc_name,
            userquota_perms[zc->zc_objset_type], cr));
}

static int
zfs_secpolicy_userspace_many(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        int err = zfs_secpolicy_read(zc, innvl, cr);
        if (err)
                return (err);

        if (zc->zc_objset_type >= ZFS_NUM_USERQUOTA_PROPS)
                return (SET_ERROR(EINVAL));

        return (zfs_secpolicy_write_perms(zc->zc_name,
            userquota_perms[zc->zc_objset_type], cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_userspace_upgrade(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        return (zfs_secpolicy_setprop(zc->zc_name, ZFS_PROP_VERSION,
            NULL, cr));
}

/* ARGSUSED */
static int
zfs_secpolicy_hold(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        nvpair_t *pair;
        nvlist_t *holds;
        int error;

        error = nvlist_lookup_nvlist(innvl, "holds", &holds);
        if (error != 0)
                return (SET_ERROR(EINVAL));

        for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
            pair = nvlist_next_nvpair(holds, pair)) {
                char fsname[ZFS_MAX_DATASET_NAME_LEN];
                error = dmu_fsname(nvpair_name(pair), fsname);
                if (error != 0)
                        return (error);
                error = zfs_secpolicy_write_perms(fsname,
                    ZFS_DELEG_PERM_HOLD, cr);
                if (error != 0)
                        return (error);
        }
        return (0);
}

/* ARGSUSED */
static int
zfs_secpolicy_release(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        nvpair_t *pair;
        int error;

        for (pair = nvlist_next_nvpair(innvl, NULL); pair != NULL;
            pair = nvlist_next_nvpair(innvl, pair)) {
                char fsname[ZFS_MAX_DATASET_NAME_LEN];
                error = dmu_fsname(nvpair_name(pair), fsname);
                if (error != 0)
                        return (error);
                error = zfs_secpolicy_write_perms(fsname,
                    ZFS_DELEG_PERM_RELEASE, cr);
                if (error != 0)
                        return (error);
        }
        return (0);
}

/*
 * Policy for allowing temporary snapshots to be taken or released
 */
static int
zfs_secpolicy_tmp_snapshot(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
{
        /*
         * A temporary snapshot is the same as a snapshot,
         * hold, destroy and release all rolled into one.
         * Delegated diff alone is sufficient that we allow this.
         */
        int error;

        if ((error = zfs_secpolicy_write_perms(zc->zc_name,
            ZFS_DELEG_PERM_DIFF, cr)) == 0)
                return (0);

        error = zfs_secpolicy_snapshot_perms(zc->zc_name, cr);
        if (error == 0)
                error = zfs_secpolicy_hold(zc, innvl, cr);
        if (error == 0)
                error = zfs_secpolicy_release(zc, innvl, cr);
        if (error == 0)
                error = zfs_secpolicy_destroy(zc, innvl, cr);
        return (error);
}

/*
 * Returns the nvlist as specified by the user in the zfs_cmd_t.
 */
static int
get_nvlist(uint64_t nvl, uint64_t size, int iflag, nvlist_t **nvp)
{
        char *packed;
        int error;
        nvlist_t *list = NULL;

        /*
         * Read in and unpack the user-supplied nvlist.
         */
        if (size == 0)
                return (SET_ERROR(EINVAL));

        packed = vmem_alloc(size, KM_SLEEP);

        if ((error = ddi_copyin((void *)(uintptr_t)nvl, packed, size,
            iflag)) != 0) {
                vmem_free(packed, size);
                return (SET_ERROR(EFAULT));
        }

        if ((error = nvlist_unpack(packed, size, &list, 0)) != 0) {
                vmem_free(packed, size);
                return (error);
        }

        vmem_free(packed, size);

        *nvp = list;
        return (0);
}

/*
 * Reduce the size of this nvlist until it can be serialized in 'max' bytes.
 * Entries will be removed from the end of the nvlist, and one int32 entry
 * named "N_MORE_ERRORS" will be added indicating how many entries were
 * removed.
 */
static int
nvlist_smush(nvlist_t *errors, size_t max)
{
        size_t size;

        size = fnvlist_size(errors);

        if (size > max) {
                nvpair_t *more_errors;
                int n = 0;

                if (max < 1024)
                        return (SET_ERROR(ENOMEM));

                fnvlist_add_int32(errors, ZPROP_N_MORE_ERRORS, 0);
                more_errors = nvlist_prev_nvpair(errors, NULL);

                do {
                        nvpair_t *pair = nvlist_prev_nvpair(errors,
                            more_errors);
                        fnvlist_remove_nvpair(errors, pair);
                        n++;
                        size = fnvlist_size(errors);
                } while (size > max);

                fnvlist_remove_nvpair(errors, more_errors);
                fnvlist_add_int32(errors, ZPROP_N_MORE_ERRORS, n);
                ASSERT3U(fnvlist_size(errors), <=, max);
        }

        return (0);
}

static int
put_nvlist(zfs_cmd_t *zc, nvlist_t *nvl)
{
        char *packed = NULL;
        int error = 0;
        size_t size;

        size = fnvlist_size(nvl);

        if (size > zc->zc_nvlist_dst_size) {
                error = SET_ERROR(ENOMEM);
        } else {
                packed = fnvlist_pack(nvl, &size);
                if (ddi_copyout(packed, (void *)(uintptr_t)zc->zc_nvlist_dst,
                    size, zc->zc_iflags) != 0)
                        error = SET_ERROR(EFAULT);
                fnvlist_pack_free(packed, size);
        }

        zc->zc_nvlist_dst_size = size;
        zc->zc_nvlist_dst_filled = B_TRUE;
        return (error);
}

static int
get_zfs_sb(const char *dsname, zfs_sb_t **zsbp)
{
        objset_t *os;
        int error;

        error = dmu_objset_hold(dsname, FTAG, &os);
        if (error != 0)
                return (error);
        if (dmu_objset_type(os) != DMU_OST_ZFS) {
                dmu_objset_rele(os, FTAG);
                return (SET_ERROR(EINVAL));
        }

        mutex_enter(&os->os_user_ptr_lock);
        *zsbp = dmu_objset_get_user(os);
        /* bump s_active only when non-zero to prevent umount race */
        if (*zsbp == NULL || (*zsbp)->z_sb == NULL ||
            !atomic_inc_not_zero(&((*zsbp)->z_sb->s_active))) {
                error = SET_ERROR(ESRCH);
        }
        mutex_exit(&os->os_user_ptr_lock);
        dmu_objset_rele(os, FTAG);
        return (error);
}

/*
 * Find a zfs_sb_t for a mounted filesystem, or create our own, in which
 * case its z_sb will be NULL, and it will be opened as the owner.
 * If 'writer' is set, the z_teardown_lock will be held for RW_WRITER,
 * which prevents all inode ops from running.
 */
static int
zfs_sb_hold(const char *name, void *tag, zfs_sb_t **zsbp, boolean_t writer)
{
        int error = 0;

        if (get_zfs_sb(name, zsbp) != 0)
                error = zfs_sb_create(name, NULL, zsbp);
        if (error == 0) {
                rrm_enter(&(*zsbp)->z_teardown_lock, (writer) ? RW_WRITER :
                    RW_READER, tag);
                if ((*zsbp)->z_unmounted) {
                        /*
                         * XXX we could probably try again, since the unmounting
                         * thread should be just about to disassociate the
                         * objset from the zsb.
                         */
                        rrm_exit(&(*zsbp)->z_teardown_lock, tag);
                        return (SET_ERROR(EBUSY));
                }
        }
        return (error);
}

static void
zfs_sb_rele(zfs_sb_t *zsb, void *tag)
{
        rrm_exit(&zsb->z_teardown_lock, tag);

        if (zsb->z_sb) {
                deactivate_super(zsb->z_sb);
        } else {
                dmu_objset_disown(zsb->z_os, zsb);
                zfs_sb_free(zsb);
        }
}

static int
zfs_ioc_pool_create(zfs_cmd_t *zc)
{
        int error;
        nvlist_t *config, *props = NULL;
        nvlist_t *rootprops = NULL;
        nvlist_t *zplprops = NULL;

        if ((error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
            zc->zc_iflags, &config)))
                return (error);

        if (zc->zc_nvlist_src_size != 0 && (error =
            get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
            zc->zc_iflags, &props))) {
                nvlist_free(config);
                return (error);
        }

        if (props) {
                nvlist_t *nvl = NULL;
                uint64_t version = SPA_VERSION;

                (void) nvlist_lookup_uint64(props,
                    zpool_prop_to_name(ZPOOL_PROP_VERSION), &version);
                if (!SPA_VERSION_IS_SUPPORTED(version)) {
                        error = SET_ERROR(EINVAL);
                        goto pool_props_bad;
                }
                (void) nvlist_lookup_nvlist(props, ZPOOL_ROOTFS_PROPS, &nvl);
                if (nvl) {
                        error = nvlist_dup(nvl, &rootprops, KM_SLEEP);
                        if (error != 0) {
                                nvlist_free(config);
                                nvlist_free(props);
                                return (error);
                        }
                        (void) nvlist_remove_all(props, ZPOOL_ROOTFS_PROPS);
                }
                VERIFY(nvlist_alloc(&zplprops, NV_UNIQUE_NAME, KM_SLEEP) == 0);
                error = zfs_fill_zplprops_root(version, rootprops,
                    zplprops, NULL);
                if (error != 0)
                        goto pool_props_bad;
        }

        error = spa_create(zc->zc_name, config, props, zplprops);

        /*
         * Set the remaining root properties
         */
        if (!error && (error = zfs_set_prop_nvlist(zc->zc_name,
            ZPROP_SRC_LOCAL, rootprops, NULL)) != 0)
                (void) spa_destroy(zc->zc_name);

pool_props_bad:
        nvlist_free(rootprops);
        nvlist_free(zplprops);
        nvlist_free(config);
        nvlist_free(props);

        return (error);
}

static int
zfs_ioc_pool_destroy(zfs_cmd_t *zc)
{
        int error;
        zfs_log_history(zc);
        error = spa_destroy(zc->zc_name);

        return (error);
}

static int
zfs_ioc_pool_import(zfs_cmd_t *zc)
{
        nvlist_t *config, *props = NULL;
        uint64_t guid;
        int error;

        if ((error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
            zc->zc_iflags, &config)) != 0)
                return (error);

        if (zc->zc_nvlist_src_size != 0 && (error =
            get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
            zc->zc_iflags, &props))) {
                nvlist_free(config);
                return (error);
        }

        if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &guid) != 0 ||
            guid != zc->zc_guid)
                error = SET_ERROR(EINVAL);
        else
                error = spa_import(zc->zc_name, config, props, zc->zc_cookie);

        if (zc->zc_nvlist_dst != 0) {
                int err;

                if ((err = put_nvlist(zc, config)) != 0)
                        error = err;
        }

        nvlist_free(config);
        nvlist_free(props);

        return (error);
}

static int
zfs_ioc_pool_export(zfs_cmd_t *zc)
{
        int error;
        boolean_t force = (boolean_t)zc->zc_cookie;
        boolean_t hardforce = (boolean_t)zc->zc_guid;

        zfs_log_history(zc);
        error = spa_export(zc->zc_name, NULL, force, hardforce);

        return (error);
}

static int
zfs_ioc_pool_configs(zfs_cmd_t *zc)
{
        nvlist_t *configs;
        int error;

        if ((configs = spa_all_configs(&zc->zc_cookie)) == NULL)
                return (SET_ERROR(EEXIST));

        error = put_nvlist(zc, configs);

        nvlist_free(configs);

        return (error);
}

/*
 * inputs:
 * zc_name              name of the pool
 *
 * outputs:
 * zc_cookie            real errno
 * zc_nvlist_dst        config nvlist
 * zc_nvlist_dst_size   size of config nvlist
 */
static int
zfs_ioc_pool_stats(zfs_cmd_t *zc)
{
        nvlist_t *config;
        int error;
        int ret = 0;

        error = spa_get_stats(zc->zc_name, &config, zc->zc_value,
            sizeof (zc->zc_value));

        if (config != NULL) {
                ret = put_nvlist(zc, config);
                nvlist_free(config);

                /*
                 * The config may be present even if 'error' is non-zero.
                 * In this case we return success, and preserve the real errno
                 * in 'zc_cookie'.
                 */
                zc->zc_cookie = error;
        } else {
                ret = error;
        }

        return (ret);
}

/*
 * Try to import the given pool, returning pool stats as appropriate so that
 * user land knows which devices are available and overall pool health.
 */
static int
zfs_ioc_pool_tryimport(zfs_cmd_t *zc)
{
        nvlist_t *tryconfig, *config;
        int error;

        if ((error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
            zc->zc_iflags, &tryconfig)) != 0)
                return (error);

        config = spa_tryimport(tryconfig);

        nvlist_free(tryconfig);

        if (config == NULL)
                return (SET_ERROR(EINVAL));

        error = put_nvlist(zc, config);
        nvlist_free(config);

        return (error);
}

/*
 * inputs:
 * zc_name              name of the pool
 * zc_cookie            scan func (pool_scan_func_t)
 */
static int
zfs_ioc_pool_scan(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);

        if (zc->zc_cookie == POOL_SCAN_NONE)
                error = spa_scan_stop(spa);
        else
                error = spa_scan(spa, zc->zc_cookie);

        spa_close(spa, FTAG);

        return (error);
}

static int
zfs_ioc_pool_freeze(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;

        error = spa_open(zc->zc_name, &spa, FTAG);
        if (error == 0) {
                spa_freeze(spa);
                spa_close(spa, FTAG);
        }
        return (error);
}

static int
zfs_ioc_pool_upgrade(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);

        if (zc->zc_cookie < spa_version(spa) ||
            !SPA_VERSION_IS_SUPPORTED(zc->zc_cookie)) {
                spa_close(spa, FTAG);
                return (SET_ERROR(EINVAL));
        }

        spa_upgrade(spa, zc->zc_cookie);
        spa_close(spa, FTAG);

        return (error);
}

static int
zfs_ioc_pool_get_history(zfs_cmd_t *zc)
{
        spa_t *spa;
        char *hist_buf;
        uint64_t size;
        int error;

        if ((size = zc->zc_history_len) == 0)
                return (SET_ERROR(EINVAL));

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);

        if (spa_version(spa) < SPA_VERSION_ZPOOL_HISTORY) {
                spa_close(spa, FTAG);
                return (SET_ERROR(ENOTSUP));
        }

        hist_buf = vmem_alloc(size, KM_SLEEP);
        if ((error = spa_history_get(spa, &zc->zc_history_offset,
            &zc->zc_history_len, hist_buf)) == 0) {
                error = ddi_copyout(hist_buf,
                    (void *)(uintptr_t)zc->zc_history,
                    zc->zc_history_len, zc->zc_iflags);
        }

        spa_close(spa, FTAG);
        vmem_free(hist_buf, size);
        return (error);
}

static int
zfs_ioc_pool_reguid(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;

        error = spa_open(zc->zc_name, &spa, FTAG);
        if (error == 0) {
                error = spa_change_guid(spa);
                spa_close(spa, FTAG);
        }
        return (error);
}

static int
zfs_ioc_dsobj_to_dsname(zfs_cmd_t *zc)
{
        return (dsl_dsobj_to_dsname(zc->zc_name, zc->zc_obj, zc->zc_value));
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_obj               object to find
 *
 * outputs:
 * zc_value             name of object
 */
static int
zfs_ioc_obj_to_path(zfs_cmd_t *zc)
{
        objset_t *os;
        int error;

        /* XXX reading from objset not owned */
        if ((error = dmu_objset_hold(zc->zc_name, FTAG, &os)) != 0)
                return (error);
        if (dmu_objset_type(os) != DMU_OST_ZFS) {
                dmu_objset_rele(os, FTAG);
                return (SET_ERROR(EINVAL));
        }
        error = zfs_obj_to_path(os, zc->zc_obj, zc->zc_value,
            sizeof (zc->zc_value));
        dmu_objset_rele(os, FTAG);

        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_obj               object to find
 *
 * outputs:
 * zc_stat              stats on object
 * zc_value             path to object
 */
static int
zfs_ioc_obj_to_stats(zfs_cmd_t *zc)
{
        objset_t *os;
        int error;

        /* XXX reading from objset not owned */
        if ((error = dmu_objset_hold(zc->zc_name, FTAG, &os)) != 0)
                return (error);
        if (dmu_objset_type(os) != DMU_OST_ZFS) {
                dmu_objset_rele(os, FTAG);
                return (SET_ERROR(EINVAL));
        }
        error = zfs_obj_to_stats(os, zc->zc_obj, &zc->zc_stat, zc->zc_value,
            sizeof (zc->zc_value));
        dmu_objset_rele(os, FTAG);

        return (error);
}

static int
zfs_ioc_vdev_add(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;
        nvlist_t *config;

        error = spa_open(zc->zc_name, &spa, FTAG);
        if (error != 0)
                return (error);

        error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
            zc->zc_iflags, &config);
        if (error == 0) {
                error = spa_vdev_add(spa, config);
                nvlist_free(config);
        }
        spa_close(spa, FTAG);
        return (error);
}

/*
 * inputs:
 * zc_name              name of the pool
 * zc_nvlist_conf       nvlist of devices to remove
 * zc_cookie            to stop the remove?
 */
static int
zfs_ioc_vdev_remove(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;

        error = spa_open(zc->zc_name, &spa, FTAG);
        if (error != 0)
                return (error);
        error = spa_vdev_remove(spa, zc->zc_guid, B_FALSE);
        spa_close(spa, FTAG);
        return (error);
}

static int
zfs_ioc_vdev_set_state(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;
        vdev_state_t newstate = VDEV_STATE_UNKNOWN;

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);
        switch (zc->zc_cookie) {
        case VDEV_STATE_ONLINE:
                error = vdev_online(spa, zc->zc_guid, zc->zc_obj, &newstate);
                break;

        case VDEV_STATE_OFFLINE:
                error = vdev_offline(spa, zc->zc_guid, zc->zc_obj);
                break;

        case VDEV_STATE_FAULTED:
                if (zc->zc_obj != VDEV_AUX_ERR_EXCEEDED &&
                    zc->zc_obj != VDEV_AUX_EXTERNAL)
                        zc->zc_obj = VDEV_AUX_ERR_EXCEEDED;

                error = vdev_fault(spa, zc->zc_guid, zc->zc_obj);
                break;

        case VDEV_STATE_DEGRADED:
                if (zc->zc_obj != VDEV_AUX_ERR_EXCEEDED &&
                    zc->zc_obj != VDEV_AUX_EXTERNAL)
                        zc->zc_obj = VDEV_AUX_ERR_EXCEEDED;

                error = vdev_degrade(spa, zc->zc_guid, zc->zc_obj);
                break;

        default:
                error = SET_ERROR(EINVAL);
        }
        zc->zc_cookie = newstate;
        spa_close(spa, FTAG);
        return (error);
}

static int
zfs_ioc_vdev_attach(zfs_cmd_t *zc)
{
        spa_t *spa;
        int replacing = zc->zc_cookie;
        nvlist_t *config;
        int error;

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);

        if ((error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
            zc->zc_iflags, &config)) == 0) {
                error = spa_vdev_attach(spa, zc->zc_guid, config, replacing);
                nvlist_free(config);
        }

        spa_close(spa, FTAG);
        return (error);
}

static int
zfs_ioc_vdev_detach(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);

        error = spa_vdev_detach(spa, zc->zc_guid, 0, B_FALSE);

        spa_close(spa, FTAG);
        return (error);
}

static int
zfs_ioc_vdev_split(zfs_cmd_t *zc)
{
        spa_t *spa;
        nvlist_t *config, *props = NULL;
        int error;
        boolean_t exp = !!(zc->zc_cookie & ZPOOL_EXPORT_AFTER_SPLIT);

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);

        if ((error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
            zc->zc_iflags, &config))) {
                spa_close(spa, FTAG);
                return (error);
        }

        if (zc->zc_nvlist_src_size != 0 && (error =
            get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
            zc->zc_iflags, &props))) {
                spa_close(spa, FTAG);
                nvlist_free(config);
                return (error);
        }

        error = spa_vdev_split_mirror(spa, zc->zc_string, config, props, exp);

        spa_close(spa, FTAG);

        nvlist_free(config);
        nvlist_free(props);

        return (error);
}

static int
zfs_ioc_vdev_setpath(zfs_cmd_t *zc)
{
        spa_t *spa;
        char *path = zc->zc_value;
        uint64_t guid = zc->zc_guid;
        int error;

        error = spa_open(zc->zc_name, &spa, FTAG);
        if (error != 0)
                return (error);

        error = spa_vdev_setpath(spa, guid, path);
        spa_close(spa, FTAG);
        return (error);
}

static int
zfs_ioc_vdev_setfru(zfs_cmd_t *zc)
{
        spa_t *spa;
        char *fru = zc->zc_value;
        uint64_t guid = zc->zc_guid;
        int error;

        error = spa_open(zc->zc_name, &spa, FTAG);
        if (error != 0)
                return (error);

        error = spa_vdev_setfru(spa, guid, fru);
        spa_close(spa, FTAG);
        return (error);
}

static int
zfs_ioc_objset_stats_impl(zfs_cmd_t *zc, objset_t *os)
{
        int error = 0;
        nvlist_t *nv;

        dmu_objset_fast_stat(os, &zc->zc_objset_stats);

        if (zc->zc_nvlist_dst != 0 &&
            (error = dsl_prop_get_all(os, &nv)) == 0) {
                dmu_objset_stats(os, nv);
                /*
                 * NB: zvol_get_stats() will read the objset contents,
                 * which we aren't supposed to do with a
                 * DS_MODE_USER hold, because it could be
                 * inconsistent.  So this is a bit of a workaround...
                 * XXX reading with out owning
                 */
                if (!zc->zc_objset_stats.dds_inconsistent &&
                    dmu_objset_type(os) == DMU_OST_ZVOL) {
                        error = zvol_get_stats(os, nv);
                        if (error == EIO)
                                return (error);
                        VERIFY0(error);
                }
                if (error == 0)
                        error = put_nvlist(zc, nv);
                nvlist_free(nv);
        }

        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_nvlist_dst_size   size of buffer for property nvlist
 *
 * outputs:
 * zc_objset_stats      stats
 * zc_nvlist_dst        property nvlist
 * zc_nvlist_dst_size   size of property nvlist
 */
static int
zfs_ioc_objset_stats(zfs_cmd_t *zc)
{
        objset_t *os;
        int error;

        error = dmu_objset_hold(zc->zc_name, FTAG, &os);
        if (error == 0) {
                error = zfs_ioc_objset_stats_impl(zc, os);
                dmu_objset_rele(os, FTAG);
        }

        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_nvlist_dst_size   size of buffer for property nvlist
 *
 * outputs:
 * zc_nvlist_dst        received property nvlist
 * zc_nvlist_dst_size   size of received property nvlist
 *
 * Gets received properties (distinct from local properties on or after
 * SPA_VERSION_RECVD_PROPS) for callers who want to differentiate received from
 * local property values.
 */
static int
zfs_ioc_objset_recvd_props(zfs_cmd_t *zc)
{
        int error = 0;
        nvlist_t *nv;

        /*
         * Without this check, we would return local property values if the
         * caller has not already received properties on or after
         * SPA_VERSION_RECVD_PROPS.
         */
        if (!dsl_prop_get_hasrecvd(zc->zc_name))
                return (SET_ERROR(ENOTSUP));

        if (zc->zc_nvlist_dst != 0 &&
            (error = dsl_prop_get_received(zc->zc_name, &nv)) == 0) {
                error = put_nvlist(zc, nv);
                nvlist_free(nv);
        }

        return (error);
}

static int
nvl_add_zplprop(objset_t *os, nvlist_t *props, zfs_prop_t prop)
{
        uint64_t value;
        int error;

        /*
         * zfs_get_zplprop() will either find a value or give us
         * the default value (if there is one).
         */
        if ((error = zfs_get_zplprop(os, prop, &value)) != 0)
                return (error);
        VERIFY(nvlist_add_uint64(props, zfs_prop_to_name(prop), value) == 0);
        return (0);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_nvlist_dst_size   size of buffer for zpl property nvlist
 *
 * outputs:
 * zc_nvlist_dst        zpl property nvlist
 * zc_nvlist_dst_size   size of zpl property nvlist
 */
static int
zfs_ioc_objset_zplprops(zfs_cmd_t *zc)
{
        objset_t *os;
        int err;

        /* XXX reading without owning */
        if ((err = dmu_objset_hold(zc->zc_name, FTAG, &os)))
                return (err);

        dmu_objset_fast_stat(os, &zc->zc_objset_stats);

        /*
         * NB: nvl_add_zplprop() will read the objset contents,
         * which we aren't supposed to do with a DS_MODE_USER
         * hold, because it could be inconsistent.
         */
        if (zc->zc_nvlist_dst != 0 &&
            !zc->zc_objset_stats.dds_inconsistent &&
            dmu_objset_type(os) == DMU_OST_ZFS) {
                nvlist_t *nv;

                VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
                if ((err = nvl_add_zplprop(os, nv, ZFS_PROP_VERSION)) == 0 &&
                    (err = nvl_add_zplprop(os, nv, ZFS_PROP_NORMALIZE)) == 0 &&
                    (err = nvl_add_zplprop(os, nv, ZFS_PROP_UTF8ONLY)) == 0 &&
                    (err = nvl_add_zplprop(os, nv, ZFS_PROP_CASE)) == 0)
                        err = put_nvlist(zc, nv);
                nvlist_free(nv);
        } else {
                err = SET_ERROR(ENOENT);
        }
        dmu_objset_rele(os, FTAG);
        return (err);
}

boolean_t
dataset_name_hidden(const char *name)
{
        /*
         * Skip over datasets that are not visible in this zone,
         * internal datasets (which have a $ in their name), and
         * temporary datasets (which have a % in their name).
         */
        if (strchr(name, '$') != NULL)
                return (B_TRUE);
        if (strchr(name, '%') != NULL)
                return (B_TRUE);
        if (!INGLOBALZONE(curproc) && !zone_dataset_visible(name, NULL))
                return (B_TRUE);
        return (B_FALSE);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_cookie            zap cursor
 * zc_nvlist_dst_size   size of buffer for property nvlist
 *
 * outputs:
 * zc_name              name of next filesystem
 * zc_cookie            zap cursor
 * zc_objset_stats      stats
 * zc_nvlist_dst        property nvlist
 * zc_nvlist_dst_size   size of property nvlist
 */
static int
zfs_ioc_dataset_list_next(zfs_cmd_t *zc)
{
        objset_t *os;
        int error;
        char *p;
        size_t orig_len = strlen(zc->zc_name);

top:
        if ((error = dmu_objset_hold(zc->zc_name, FTAG, &os))) {
                if (error == ENOENT)
                        error = SET_ERROR(ESRCH);
                return (error);
        }

        p = strrchr(zc->zc_name, '/');
        if (p == NULL || p[1] != '\0')
                (void) strlcat(zc->zc_name, "/", sizeof (zc->zc_name));
        p = zc->zc_name + strlen(zc->zc_name);

        do {
                error = dmu_dir_list_next(os,
                    sizeof (zc->zc_name) - (p - zc->zc_name), p,
                    NULL, &zc->zc_cookie);
                if (error == ENOENT)
                        error = SET_ERROR(ESRCH);
        } while (error == 0 && dataset_name_hidden(zc->zc_name));
        dmu_objset_rele(os, FTAG);

        /*
         * If it's an internal dataset (ie. with a '$' in its name),
         * don't try to get stats for it, otherwise we'll return ENOENT.
         */
        if (error == 0 && strchr(zc->zc_name, '$') == NULL) {
                error = zfs_ioc_objset_stats(zc); /* fill in the stats */
                if (error == ENOENT) {
                        /* We lost a race with destroy, get the next one. */
                        zc->zc_name[orig_len] = '\0';
                        goto top;
                }
        }
        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_cookie            zap cursor
 * zc_nvlist_dst_size   size of buffer for property nvlist
 *
 * outputs:
 * zc_name              name of next snapshot
 * zc_objset_stats      stats
 * zc_nvlist_dst        property nvlist
 * zc_nvlist_dst_size   size of property nvlist
 */
static int
zfs_ioc_snapshot_list_next(zfs_cmd_t *zc)
{
        objset_t *os;
        int error;

        error = dmu_objset_hold(zc->zc_name, FTAG, &os);
        if (error != 0) {
                return (error == ENOENT ? ESRCH : error);
        }

        /*
         * A dataset name of maximum length cannot have any snapshots,
         * so exit immediately.
         */
        if (strlcat(zc->zc_name, "@", sizeof (zc->zc_name)) >=
            ZFS_MAX_DATASET_NAME_LEN) {
                dmu_objset_rele(os, FTAG);
                return (SET_ERROR(ESRCH));
        }

        error = dmu_snapshot_list_next(os,
            sizeof (zc->zc_name) - strlen(zc->zc_name),
            zc->zc_name + strlen(zc->zc_name), &zc->zc_obj, &zc->zc_cookie,
            NULL);

        if (error == 0 && !zc->zc_simple) {
                dsl_dataset_t *ds;
                dsl_pool_t *dp = os->os_dsl_dataset->ds_dir->dd_pool;

                error = dsl_dataset_hold_obj(dp, zc->zc_obj, FTAG, &ds);
                if (error == 0) {
                        objset_t *ossnap;

                        error = dmu_objset_from_ds(ds, &ossnap);
                        if (error == 0)
                                error = zfs_ioc_objset_stats_impl(zc, ossnap);
                        dsl_dataset_rele(ds, FTAG);
                }
        } else if (error == ENOENT) {
                error = SET_ERROR(ESRCH);
        }

        dmu_objset_rele(os, FTAG);
        /* if we failed, undo the @ that we tacked on to zc_name */
        if (error != 0)
                *strchr(zc->zc_name, '@') = '\0';
        return (error);
}

static int
zfs_prop_set_userquota(const char *dsname, nvpair_t *pair)
{
        const char *propname = nvpair_name(pair);
        uint64_t *valary;
        unsigned int vallen;
        const char *domain;
        char *dash;
        zfs_userquota_prop_t type;
        uint64_t rid;
        uint64_t quota;
        zfs_sb_t *zsb;
        int err;

        if (nvpair_type(pair) == DATA_TYPE_NVLIST) {
                nvlist_t *attrs;
                VERIFY(nvpair_value_nvlist(pair, &attrs) == 0);
                if (nvlist_lookup_nvpair(attrs, ZPROP_VALUE,
                    &pair) != 0)
                        return (SET_ERROR(EINVAL));
        }

        /*
         * A correctly constructed propname is encoded as
         * userquota@<rid>-<domain>.
         */
        if ((dash = strchr(propname, '-')) == NULL ||
            nvpair_value_uint64_array(pair, &valary, &vallen) != 0 ||
            vallen != 3)
                return (SET_ERROR(EINVAL));

        domain = dash + 1;
        type = valary[0];
        rid = valary[1];
        quota = valary[2];

        err = zfs_sb_hold(dsname, FTAG, &zsb, B_FALSE);
        if (err == 0) {
                err = zfs_set_userquota(zsb, type, domain, rid, quota);
                zfs_sb_rele(zsb, FTAG);
        }

        return (err);
}

/*
 * If the named property is one that has a special function to set its value,
 * return 0 on success and a positive error code on failure; otherwise if it is
 * not one of the special properties handled by this function, return -1.
 *
 * XXX: It would be better for callers of the property interface if we handled
 * these special cases in dsl_prop.c (in the dsl layer).
 */
static int
zfs_prop_set_special(const char *dsname, zprop_source_t source,
    nvpair_t *pair)
{
        const char *propname = nvpair_name(pair);
        zfs_prop_t prop = zfs_name_to_prop(propname);
        uint64_t intval;
        int err = -1;

        if (prop == ZPROP_INVAL) {
                if (zfs_prop_userquota(propname))
                        return (zfs_prop_set_userquota(dsname, pair));
                return (-1);
        }

        if (nvpair_type(pair) == DATA_TYPE_NVLIST) {
                nvlist_t *attrs;
                VERIFY(nvpair_value_nvlist(pair, &attrs) == 0);
                VERIFY(nvlist_lookup_nvpair(attrs, ZPROP_VALUE,
                    &pair) == 0);
        }

        if (zfs_prop_get_type(prop) == PROP_TYPE_STRING)
                return (-1);

        VERIFY(0 == nvpair_value_uint64(pair, &intval));

        switch (prop) {
        case ZFS_PROP_QUOTA:
                err = dsl_dir_set_quota(dsname, source, intval);
                break;
        case ZFS_PROP_REFQUOTA:
                err = dsl_dataset_set_refquota(dsname, source, intval);
                break;
        case ZFS_PROP_FILESYSTEM_LIMIT:
        case ZFS_PROP_SNAPSHOT_LIMIT:
                if (intval == UINT64_MAX) {
                        /* clearing the limit, just do it */
                        err = 0;
                } else {
                        err = dsl_dir_activate_fs_ss_limit(dsname);
                }
                /*
                 * Set err to -1 to force the zfs_set_prop_nvlist code down the
                 * default path to set the value in the nvlist.
                 */
                if (err == 0)
                        err = -1;
                break;
        case ZFS_PROP_RESERVATION:
                err = dsl_dir_set_reservation(dsname, source, intval);
                break;
        case ZFS_PROP_REFRESERVATION:
                err = dsl_dataset_set_refreservation(dsname, source, intval);
                break;
        case ZFS_PROP_VOLSIZE:
                err = zvol_set_volsize(dsname, intval);
                break;
        case ZFS_PROP_SNAPDEV:
                err = zvol_set_snapdev(dsname, source, intval);
                break;
        case ZFS_PROP_VERSION:
        {
                zfs_sb_t *zsb;

                if ((err = zfs_sb_hold(dsname, FTAG, &zsb, B_TRUE)) != 0)
                        break;

                err = zfs_set_version(zsb, intval);
                zfs_sb_rele(zsb, FTAG);

                if (err == 0 && intval >= ZPL_VERSION_USERSPACE) {
                        zfs_cmd_t *zc;

                        zc = kmem_zalloc(sizeof (zfs_cmd_t), KM_SLEEP);
                        (void) strcpy(zc->zc_name, dsname);
                        (void) zfs_ioc_userspace_upgrade(zc);
                        kmem_free(zc, sizeof (zfs_cmd_t));
                }
                break;
        }
        default:
                err = -1;
        }

        return (err);
}

/*
 * This function is best effort. If it fails to set any of the given properties,
 * it continues to set as many as it can and returns the last error
 * encountered. If the caller provides a non-NULL errlist, it will be filled in
 * with the list of names of all the properties that failed along with the
 * corresponding error numbers.
 *
 * If every property is set successfully, zero is returned and errlist is not
 * modified.
 */
int
zfs_set_prop_nvlist(const char *dsname, zprop_source_t source, nvlist_t *nvl,
    nvlist_t *errlist)
{
        nvpair_t *pair;
        nvpair_t *propval;
        int rv = 0;
        uint64_t intval;
        char *strval;

        nvlist_t *genericnvl = fnvlist_alloc();
        nvlist_t *retrynvl = fnvlist_alloc();
retry:
        pair = NULL;
        while ((pair = nvlist_next_nvpair(nvl, pair)) != NULL) {
                const char *propname = nvpair_name(pair);
                zfs_prop_t prop = zfs_name_to_prop(propname);
                int err = 0;

                /* decode the property value */
                propval = pair;
                if (nvpair_type(pair) == DATA_TYPE_NVLIST) {
                        nvlist_t *attrs;
                        attrs = fnvpair_value_nvlist(pair);
                        if (nvlist_lookup_nvpair(attrs, ZPROP_VALUE,
                            &propval) != 0)
                                err = SET_ERROR(EINVAL);
                }

                /* Validate value type */
                if (err == 0 && prop == ZPROP_INVAL) {
                        if (zfs_prop_user(propname)) {
                                if (nvpair_type(propval) != DATA_TYPE_STRING)
                                        err = SET_ERROR(EINVAL);
                        } else if (zfs_prop_userquota(propname)) {
                                if (nvpair_type(propval) !=
                                    DATA_TYPE_UINT64_ARRAY)
                                        err = SET_ERROR(EINVAL);
                        } else {
                                err = SET_ERROR(EINVAL);
                        }
                } else if (err == 0) {
                        if (nvpair_type(propval) == DATA_TYPE_STRING) {
                                if (zfs_prop_get_type(prop) != PROP_TYPE_STRING)
                                        err = SET_ERROR(EINVAL);
                        } else if (nvpair_type(propval) == DATA_TYPE_UINT64) {
                                const char *unused;

                                intval = fnvpair_value_uint64(propval);

                                switch (zfs_prop_get_type(prop)) {
                                case PROP_TYPE_NUMBER:
                                        break;
                                case PROP_TYPE_STRING:
                                        err = SET_ERROR(EINVAL);
                                        break;
                                case PROP_TYPE_INDEX:
                                        if (zfs_prop_index_to_string(prop,
                                            intval, &unused) != 0)
                                                err = SET_ERROR(EINVAL);
                                        break;
                                default:
                                        cmn_err(CE_PANIC,
                                            "unknown property type");
                                }
                        } else {
                                err = SET_ERROR(EINVAL);
                        }
                }

                /* Validate permissions */
                if (err == 0)
                        err = zfs_check_settable(dsname, pair, CRED());

                if (err == 0) {
                        err = zfs_prop_set_special(dsname, source, pair);
                        if (err == -1) {
                                /*
                                 * For better performance we build up a list of
                                 * properties to set in a single transaction.
                                 */
                                err = nvlist_add_nvpair(genericnvl, pair);
                        } else if (err != 0 && nvl != retrynvl) {
                                /*
                                 * This may be a spurious error caused by
                                 * receiving quota and reservation out of order.
                                 * Try again in a second pass.
                                 */
                                err = nvlist_add_nvpair(retrynvl, pair);
                        }
                }

                if (err != 0) {
                        if (errlist != NULL)
                                fnvlist_add_int32(errlist, propname, err);
                        rv = err;
                }
        }

        if (nvl != retrynvl && !nvlist_empty(retrynvl)) {
                nvl = retrynvl;
                goto retry;
        }

        if (!nvlist_empty(genericnvl) &&
            dsl_props_set(dsname, source, genericnvl) != 0) {
                /*
                 * If this fails, we still want to set as many properties as we
                 * can, so try setting them individually.
                 */
                pair = NULL;
                while ((pair = nvlist_next_nvpair(genericnvl, pair)) != NULL) {
                        const char *propname = nvpair_name(pair);
                        int err = 0;

                        propval = pair;
                        if (nvpair_type(pair) == DATA_TYPE_NVLIST) {
                                nvlist_t *attrs;
                                attrs = fnvpair_value_nvlist(pair);
                                propval = fnvlist_lookup_nvpair(attrs,
                                    ZPROP_VALUE);
                        }

                        if (nvpair_type(propval) == DATA_TYPE_STRING) {
                                strval = fnvpair_value_string(propval);
                                err = dsl_prop_set_string(dsname, propname,
                                    source, strval);
                        } else {
                                intval = fnvpair_value_uint64(propval);
                                err = dsl_prop_set_int(dsname, propname, source,
                                    intval);
                        }

                        if (err != 0) {
                                if (errlist != NULL) {
                                        fnvlist_add_int32(errlist, propname,
                                            err);
                                }
                                rv = err;
                        }
                }
        }
        nvlist_free(genericnvl);
        nvlist_free(retrynvl);

        return (rv);
}

/*
 * Check that all the properties are valid user properties.
 */
static int
zfs_check_userprops(const char *fsname, nvlist_t *nvl)
{
        nvpair_t *pair = NULL;
        int error = 0;

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

                if (!zfs_prop_user(propname) ||
                    nvpair_type(pair) != DATA_TYPE_STRING)
                        return (SET_ERROR(EINVAL));

                if ((error = zfs_secpolicy_write_perms(fsname,
                    ZFS_DELEG_PERM_USERPROP, CRED())))
                        return (error);

                if (strlen(propname) >= ZAP_MAXNAMELEN)
                        return (SET_ERROR(ENAMETOOLONG));

                if (strlen(fnvpair_value_string(pair)) >= ZAP_MAXVALUELEN)
                        return (SET_ERROR(E2BIG));
        }
        return (0);
}

static void
props_skip(nvlist_t *props, nvlist_t *skipped, nvlist_t **newprops)
{
        nvpair_t *pair;

        VERIFY(nvlist_alloc(newprops, NV_UNIQUE_NAME, KM_SLEEP) == 0);

        pair = NULL;
        while ((pair = nvlist_next_nvpair(props, pair)) != NULL) {
                if (nvlist_exists(skipped, nvpair_name(pair)))
                        continue;

                VERIFY(nvlist_add_nvpair(*newprops, pair) == 0);
        }
}

static int
clear_received_props(const char *dsname, nvlist_t *props,
    nvlist_t *skipped)
{
        int err = 0;
        nvlist_t *cleared_props = NULL;
        props_skip(props, skipped, &cleared_props);
        if (!nvlist_empty(cleared_props)) {
                /*
                 * Acts on local properties until the dataset has received
                 * properties at least once on or after SPA_VERSION_RECVD_PROPS.
                 */
                zprop_source_t flags = (ZPROP_SRC_NONE |
                    (dsl_prop_get_hasrecvd(dsname) ? ZPROP_SRC_RECEIVED : 0));
                err = zfs_set_prop_nvlist(dsname, flags, cleared_props, NULL);
        }
        nvlist_free(cleared_props);
        return (err);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_value             name of property to set
 * zc_nvlist_src{_size} nvlist of properties to apply
 * zc_cookie            received properties flag
 *
 * outputs:
 * zc_nvlist_dst{_size} error for each unapplied received property
 */
static int
zfs_ioc_set_prop(zfs_cmd_t *zc)
{
        nvlist_t *nvl;
        boolean_t received = zc->zc_cookie;
        zprop_source_t source = (received ? ZPROP_SRC_RECEIVED :
            ZPROP_SRC_LOCAL);
        nvlist_t *errors;
        int error;

        if ((error = get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
            zc->zc_iflags, &nvl)) != 0)
                return (error);

        if (received) {
                nvlist_t *origprops;

                if (dsl_prop_get_received(zc->zc_name, &origprops) == 0) {
                        (void) clear_received_props(zc->zc_name,
                            origprops, nvl);
                        nvlist_free(origprops);
                }

                error = dsl_prop_set_hasrecvd(zc->zc_name);
        }

        errors = fnvlist_alloc();
        if (error == 0)
                error = zfs_set_prop_nvlist(zc->zc_name, source, nvl, errors);

        if (zc->zc_nvlist_dst != 0 && errors != NULL) {
                (void) put_nvlist(zc, errors);
        }

        nvlist_free(errors);
        nvlist_free(nvl);
        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_value             name of property to inherit
 * zc_cookie            revert to received value if TRUE
 *
 * outputs:             none
 */
static int
zfs_ioc_inherit_prop(zfs_cmd_t *zc)
{
        const char *propname = zc->zc_value;
        zfs_prop_t prop = zfs_name_to_prop(propname);
        boolean_t received = zc->zc_cookie;
        zprop_source_t source = (received
            ? ZPROP_SRC_NONE            /* revert to received value, if any */
            : ZPROP_SRC_INHERITED);     /* explicitly inherit */

        if (received) {
                nvlist_t *dummy;
                nvpair_t *pair;
                zprop_type_t type;
                int err;

                /*
                 * zfs_prop_set_special() expects properties in the form of an
                 * nvpair with type info.
                 */
                if (prop == ZPROP_INVAL) {
                        if (!zfs_prop_user(propname))
                                return (SET_ERROR(EINVAL));

                        type = PROP_TYPE_STRING;
                } else if (prop == ZFS_PROP_VOLSIZE ||
                    prop == ZFS_PROP_VERSION) {
                        return (SET_ERROR(EINVAL));
                } else {
                        type = zfs_prop_get_type(prop);
                }

                VERIFY(nvlist_alloc(&dummy, NV_UNIQUE_NAME, KM_SLEEP) == 0);

                switch (type) {
                case PROP_TYPE_STRING:
                        VERIFY(0 == nvlist_add_string(dummy, propname, ""));
                        break;
                case PROP_TYPE_NUMBER:
                case PROP_TYPE_INDEX:
                        VERIFY(0 == nvlist_add_uint64(dummy, propname, 0));
                        break;
                default:
                        nvlist_free(dummy);
                        return (SET_ERROR(EINVAL));
                }

                pair = nvlist_next_nvpair(dummy, NULL);
                err = zfs_prop_set_special(zc->zc_name, source, pair);
                nvlist_free(dummy);
                if (err != -1)
                        return (err); /* special property already handled */
        } else {
                /*
                 * Only check this in the non-received case. We want to allow
                 * 'inherit -S' to revert non-inheritable properties like quota
                 * and reservation to the received or default values even though
                 * they are not considered inheritable.
                 */
                if (prop != ZPROP_INVAL && !zfs_prop_inheritable(prop))
                        return (SET_ERROR(EINVAL));
        }

        /* property name has been validated by zfs_secpolicy_inherit_prop() */
        return (dsl_prop_inherit(zc->zc_name, zc->zc_value, source));
}

static int
zfs_ioc_pool_set_props(zfs_cmd_t *zc)
{
        nvlist_t *props;
        spa_t *spa;
        int error;
        nvpair_t *pair;

        if ((error = get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
            zc->zc_iflags, &props)))
                return (error);

        /*
         * If the only property is the configfile, then just do a spa_lookup()
         * to handle the faulted case.
         */
        pair = nvlist_next_nvpair(props, NULL);
        if (pair != NULL && strcmp(nvpair_name(pair),
            zpool_prop_to_name(ZPOOL_PROP_CACHEFILE)) == 0 &&
            nvlist_next_nvpair(props, pair) == NULL) {
                mutex_enter(&spa_namespace_lock);
                if ((spa = spa_lookup(zc->zc_name)) != NULL) {
                        spa_configfile_set(spa, props, B_FALSE);
                        spa_config_sync(spa, B_FALSE, B_TRUE);
                }
                mutex_exit(&spa_namespace_lock);
                if (spa != NULL) {
                        nvlist_free(props);
                        return (0);
                }
        }

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0) {
                nvlist_free(props);
                return (error);
        }

        error = spa_prop_set(spa, props);

        nvlist_free(props);
        spa_close(spa, FTAG);

        return (error);
}

static int
zfs_ioc_pool_get_props(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;
        nvlist_t *nvp = NULL;

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0) {
                /*
                 * If the pool is faulted, there may be properties we can still
                 * get (such as altroot and cachefile), so attempt to get them
                 * anyway.
                 */
                mutex_enter(&spa_namespace_lock);
                if ((spa = spa_lookup(zc->zc_name)) != NULL)
                        error = spa_prop_get(spa, &nvp);
                mutex_exit(&spa_namespace_lock);
        } else {
                error = spa_prop_get(spa, &nvp);
                spa_close(spa, FTAG);
        }

        if (error == 0 && zc->zc_nvlist_dst != 0)
                error = put_nvlist(zc, nvp);
        else
                error = SET_ERROR(EFAULT);

        nvlist_free(nvp);
        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_nvlist_src{_size} nvlist of delegated permissions
 * zc_perm_action       allow/unallow flag
 *
 * outputs:             none
 */
static int
zfs_ioc_set_fsacl(zfs_cmd_t *zc)
{
        int error;
        nvlist_t *fsaclnv = NULL;

        if ((error = get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
            zc->zc_iflags, &fsaclnv)) != 0)
                return (error);

        /*
         * Verify nvlist is constructed correctly
         */
        if ((error = zfs_deleg_verify_nvlist(fsaclnv)) != 0) {
                nvlist_free(fsaclnv);
                return (SET_ERROR(EINVAL));
        }

        /*
         * If we don't have PRIV_SYS_MOUNT, then validate
         * that user is allowed to hand out each permission in
         * the nvlist(s)
         */

        error = secpolicy_zfs(CRED());
        if (error != 0) {
                if (zc->zc_perm_action == B_FALSE) {
                        error = dsl_deleg_can_allow(zc->zc_name,
                            fsaclnv, CRED());
                } else {
                        error = dsl_deleg_can_unallow(zc->zc_name,
                            fsaclnv, CRED());
                }
        }

        if (error == 0)
                error = dsl_deleg_set(zc->zc_name, fsaclnv, zc->zc_perm_action);

        nvlist_free(fsaclnv);
        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 *
 * outputs:
 * zc_nvlist_src{_size} nvlist of delegated permissions
 */
static int
zfs_ioc_get_fsacl(zfs_cmd_t *zc)
{
        nvlist_t *nvp;
        int error;

        if ((error = dsl_deleg_get(zc->zc_name, &nvp)) == 0) {
                error = put_nvlist(zc, nvp);
                nvlist_free(nvp);
        }

        return (error);
}

/* ARGSUSED */
static void
zfs_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
{
        zfs_creat_t *zct = arg;

        zfs_create_fs(os, cr, zct->zct_zplprops, tx);
}

#define ZFS_PROP_UNDEFINED      ((uint64_t)-1)

/*
 * inputs:
 * os                   parent objset pointer (NULL if root fs)
 * fuids_ok             fuids allowed in this version of the spa?
 * sa_ok                SAs allowed in this version of the spa?
 * createprops          list of properties requested by creator
 *
 * outputs:
 * zplprops     values for the zplprops we attach to the master node object
 * is_ci        true if requested file system will be purely case-insensitive
 *
 * Determine the settings for utf8only, normalization and
 * casesensitivity.  Specific values may have been requested by the
 * creator and/or we can inherit values from the parent dataset.  If
 * the file system is of too early a vintage, a creator can not
 * request settings for these properties, even if the requested
 * setting is the default value.  We don't actually want to create dsl
 * properties for these, so remove them from the source nvlist after
 * processing.
 */
static int
zfs_fill_zplprops_impl(objset_t *os, uint64_t zplver,
    boolean_t fuids_ok, boolean_t sa_ok, nvlist_t *createprops,
    nvlist_t *zplprops, boolean_t *is_ci)
{
        uint64_t sense = ZFS_PROP_UNDEFINED;
        uint64_t norm = ZFS_PROP_UNDEFINED;
        uint64_t u8 = ZFS_PROP_UNDEFINED;
        int error;

        ASSERT(zplprops != NULL);

        /*
         * Pull out creator prop choices, if any.
         */
        if (createprops) {
                (void) nvlist_lookup_uint64(createprops,
                    zfs_prop_to_name(ZFS_PROP_VERSION), &zplver);
                (void) nvlist_lookup_uint64(createprops,
                    zfs_prop_to_name(ZFS_PROP_NORMALIZE), &norm);
                (void) nvlist_remove_all(createprops,
                    zfs_prop_to_name(ZFS_PROP_NORMALIZE));
                (void) nvlist_lookup_uint64(createprops,
                    zfs_prop_to_name(ZFS_PROP_UTF8ONLY), &u8);
                (void) nvlist_remove_all(createprops,
                    zfs_prop_to_name(ZFS_PROP_UTF8ONLY));
                (void) nvlist_lookup_uint64(createprops,
                    zfs_prop_to_name(ZFS_PROP_CASE), &sense);
                (void) nvlist_remove_all(createprops,
                    zfs_prop_to_name(ZFS_PROP_CASE));
        }

        /*
         * If the zpl version requested is whacky or the file system
         * or pool is version is too "young" to support normalization
         * and the creator tried to set a value for one of the props,
         * error out.
         */
        if ((zplver < ZPL_VERSION_INITIAL || zplver > ZPL_VERSION) ||
            (zplver >= ZPL_VERSION_FUID && !fuids_ok) ||
            (zplver >= ZPL_VERSION_SA && !sa_ok) ||
            (zplver < ZPL_VERSION_NORMALIZATION &&
            (norm != ZFS_PROP_UNDEFINED || u8 != ZFS_PROP_UNDEFINED ||
            sense != ZFS_PROP_UNDEFINED)))
                return (SET_ERROR(ENOTSUP));

        /*
         * Put the version in the zplprops
         */
        VERIFY(nvlist_add_uint64(zplprops,
            zfs_prop_to_name(ZFS_PROP_VERSION), zplver) == 0);

        if (norm == ZFS_PROP_UNDEFINED &&
            (error = zfs_get_zplprop(os, ZFS_PROP_NORMALIZE, &norm)) != 0)
                return (error);
        VERIFY(nvlist_add_uint64(zplprops,
            zfs_prop_to_name(ZFS_PROP_NORMALIZE), norm) == 0);

        /*
         * If we're normalizing, names must always be valid UTF-8 strings.
         */
        if (norm)
                u8 = 1;
        if (u8 == ZFS_PROP_UNDEFINED &&
            (error = zfs_get_zplprop(os, ZFS_PROP_UTF8ONLY, &u8)) != 0)
                return (error);
        VERIFY(nvlist_add_uint64(zplprops,
            zfs_prop_to_name(ZFS_PROP_UTF8ONLY), u8) == 0);

        if (sense == ZFS_PROP_UNDEFINED &&
            (error = zfs_get_zplprop(os, ZFS_PROP_CASE, &sense)) != 0)
                return (error);
        VERIFY(nvlist_add_uint64(zplprops,
            zfs_prop_to_name(ZFS_PROP_CASE), sense) == 0);

        if (is_ci)
                *is_ci = (sense == ZFS_CASE_INSENSITIVE);

        return (0);
}

static int
zfs_fill_zplprops(const char *dataset, nvlist_t *createprops,
    nvlist_t *zplprops, boolean_t *is_ci)
{
        boolean_t fuids_ok, sa_ok;
        uint64_t zplver = ZPL_VERSION;
        objset_t *os = NULL;
        char parentname[ZFS_MAX_DATASET_NAME_LEN];
        char *cp;
        spa_t *spa;
        uint64_t spa_vers;
        int error;

        (void) strlcpy(parentname, dataset, sizeof (parentname));
        cp = strrchr(parentname, '/');
        ASSERT(cp != NULL);
        cp[0] = '\0';

        if ((error = spa_open(dataset, &spa, FTAG)) != 0)
                return (error);

        spa_vers = spa_version(spa);
        spa_close(spa, FTAG);

        zplver = zfs_zpl_version_map(spa_vers);
        fuids_ok = (zplver >= ZPL_VERSION_FUID);
        sa_ok = (zplver >= ZPL_VERSION_SA);

        /*
         * Open parent object set so we can inherit zplprop values.
         */
        if ((error = dmu_objset_hold(parentname, FTAG, &os)) != 0)
                return (error);

        error = zfs_fill_zplprops_impl(os, zplver, fuids_ok, sa_ok, createprops,
            zplprops, is_ci);
        dmu_objset_rele(os, FTAG);
        return (error);
}

static int
zfs_fill_zplprops_root(uint64_t spa_vers, nvlist_t *createprops,
    nvlist_t *zplprops, boolean_t *is_ci)
{
        boolean_t fuids_ok;
        boolean_t sa_ok;
        uint64_t zplver = ZPL_VERSION;
        int error;

        zplver = zfs_zpl_version_map(spa_vers);
        fuids_ok = (zplver >= ZPL_VERSION_FUID);
        sa_ok = (zplver >= ZPL_VERSION_SA);

        error = zfs_fill_zplprops_impl(NULL, zplver, fuids_ok, sa_ok,
            createprops, zplprops, is_ci);
        return (error);
}

/*
 * innvl: {
 *     "type" -> dmu_objset_type_t (int32)
 *     (optional) "props" -> { prop -> value }
 * }
 *
 * outnvl: propname -> error code (int32)
 */
static int
zfs_ioc_create(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
{
        int error = 0;
        zfs_creat_t zct = { 0 };
        nvlist_t *nvprops = NULL;
        void (*cbfunc)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx);
        int32_t type32;
        dmu_objset_type_t type;
        boolean_t is_insensitive = B_FALSE;

        if (nvlist_lookup_int32(innvl, "type", &type32) != 0)
                return (SET_ERROR(EINVAL));
        type = type32;
        (void) nvlist_lookup_nvlist(innvl, "props", &nvprops);

        switch (type) {
        case DMU_OST_ZFS:
                cbfunc = zfs_create_cb;
                break;

        case DMU_OST_ZVOL:
                cbfunc = zvol_create_cb;
                break;

        default:
                cbfunc = NULL;
                break;
        }
        if (strchr(fsname, '@') ||
            strchr(fsname, '%'))
                return (SET_ERROR(EINVAL));

        zct.zct_props = nvprops;

        if (cbfunc == NULL)
                return (SET_ERROR(EINVAL));

        if (type == DMU_OST_ZVOL) {
                uint64_t volsize, volblocksize;

                if (nvprops == NULL)
                        return (SET_ERROR(EINVAL));
                if (nvlist_lookup_uint64(nvprops,
                    zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) != 0)
                        return (SET_ERROR(EINVAL));

                if ((error = nvlist_lookup_uint64(nvprops,
                    zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE),
                    &volblocksize)) != 0 && error != ENOENT)
                        return (SET_ERROR(EINVAL));

                if (error != 0)
                        volblocksize = zfs_prop_default_numeric(
                            ZFS_PROP_VOLBLOCKSIZE);

                if ((error = zvol_check_volblocksize(fsname,
                    volblocksize)) != 0 ||
                    (error = zvol_check_volsize(volsize,
                    volblocksize)) != 0)
                        return (error);
        } else if (type == DMU_OST_ZFS) {
                int error;

                /*
                 * We have to have normalization and
                 * case-folding flags correct when we do the
                 * file system creation, so go figure them out
                 * now.
                 */
                VERIFY(nvlist_alloc(&zct.zct_zplprops,
                    NV_UNIQUE_NAME, KM_SLEEP) == 0);
                error = zfs_fill_zplprops(fsname, nvprops,
                    zct.zct_zplprops, &is_insensitive);
                if (error != 0) {
                        nvlist_free(zct.zct_zplprops);
                        return (error);
                }
        }

        error = dmu_objset_create(fsname, type,
            is_insensitive ? DS_FLAG_CI_DATASET : 0, cbfunc, &zct);
        nvlist_free(zct.zct_zplprops);

        /*
         * It would be nice to do this atomically.
         */
        if (error == 0) {
                error = zfs_set_prop_nvlist(fsname, ZPROP_SRC_LOCAL,
                    nvprops, outnvl);
                if (error != 0) {
                        spa_t *spa;
                        int error2;

                        /*
                         * Volumes will return EBUSY and cannot be destroyed
                         * until all asynchronous minor handling has completed.
                         * Wait for the spa_zvol_taskq to drain then retry.
                         */
                        error2 = dsl_destroy_head(fsname);
                        while ((error2 == EBUSY) && (type == DMU_OST_ZVOL)) {
                                error2 = spa_open(fsname, &spa, FTAG);
                                if (error2 == 0) {
                                        taskq_wait(spa->spa_zvol_taskq);
                                        spa_close(spa, FTAG);
                                }
                                error2 = dsl_destroy_head(fsname);
                        }
                }
        }
        return (error);
}

/*
 * innvl: {
 *     "origin" -> name of origin snapshot
 *     (optional) "props" -> { prop -> value }
 * }
 *
 * outputs:
 * outnvl: propname -> error code (int32)
 */
static int
zfs_ioc_clone(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
{
        int error = 0;
        nvlist_t *nvprops = NULL;
        char *origin_name;

        if (nvlist_lookup_string(innvl, "origin", &origin_name) != 0)
                return (SET_ERROR(EINVAL));
        (void) nvlist_lookup_nvlist(innvl, "props", &nvprops);

        if (strchr(fsname, '@') ||
            strchr(fsname, '%'))
                return (SET_ERROR(EINVAL));

        if (dataset_namecheck(origin_name, NULL, NULL) != 0)
                return (SET_ERROR(EINVAL));
        error = dmu_objset_clone(fsname, origin_name);
        if (error != 0)
                return (error);

        /*
         * It would be nice to do this atomically.
         */
        if (error == 0) {
                error = zfs_set_prop_nvlist(fsname, ZPROP_SRC_LOCAL,
                    nvprops, outnvl);
                if (error != 0)
                        (void) dsl_destroy_head(fsname);
        }
        return (error);
}

/*
 * innvl: {
 *     "snaps" -> { snapshot1, snapshot2 }
 *     (optional) "props" -> { prop -> value (string) }
 * }
 *
 * outnvl: snapshot -> error code (int32)
 */
static int
zfs_ioc_snapshot(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
{
        nvlist_t *snaps;
        nvlist_t *props = NULL;
        int error, poollen;
        nvpair_t *pair, *pair2;

        (void) nvlist_lookup_nvlist(innvl, "props", &props);
        if ((error = zfs_check_userprops(poolname, props)) != 0)
                return (error);

        if (!nvlist_empty(props) &&
            zfs_earlier_version(poolname, SPA_VERSION_SNAP_PROPS))
                return (SET_ERROR(ENOTSUP));

        if (nvlist_lookup_nvlist(innvl, "snaps", &snaps) != 0)
                return (SET_ERROR(EINVAL));
        poollen = strlen(poolname);
        for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
            pair = nvlist_next_nvpair(snaps, pair)) {
                const char *name = nvpair_name(pair);
                const char *cp = strchr(name, '@');

                /*
                 * The snap name must contain an @, and the part after it must
                 * contain only valid characters.
                 */
                if (cp == NULL ||
                    zfs_component_namecheck(cp + 1, NULL, NULL) != 0)
                        return (SET_ERROR(EINVAL));

                /*
                 * The snap must be in the specified pool.
                 */
                if (strncmp(name, poolname, poollen) != 0 ||
                    (name[poollen] != '/' && name[poollen] != '@'))
                        return (SET_ERROR(EXDEV));

                /* This must be the only snap of this fs. */
                for (pair2 = nvlist_next_nvpair(snaps, pair);
                    pair2 != NULL; pair2 = nvlist_next_nvpair(snaps, pair2)) {
                        if (strncmp(name, nvpair_name(pair2), cp - name + 1)
                            == 0) {
                                return (SET_ERROR(EXDEV));
                        }
                }
        }

        error = dsl_dataset_snapshot(snaps, props, outnvl);

        return (error);
}

/*
 * innvl: "message" -> string
 */
/* ARGSUSED */
static int
zfs_ioc_log_history(const char *unused, nvlist_t *innvl, nvlist_t *outnvl)
{
        char *message;
        spa_t *spa;
        int error;
        char *poolname;

        /*
         * The poolname in the ioctl is not set, we get it from the TSD,
         * which was set at the end of the last successful ioctl that allows
         * logging.  The secpolicy func already checked that it is set.
         * Only one log ioctl is allowed after each successful ioctl, so
         * we clear the TSD here.
         */
        poolname = tsd_get(zfs_allow_log_key);
        if (poolname == NULL)
                return (SET_ERROR(EINVAL));
        (void) tsd_set(zfs_allow_log_key, NULL);
        error = spa_open(poolname, &spa, FTAG);
        strfree(poolname);
        if (error != 0)
                return (error);

        if (nvlist_lookup_string(innvl, "message", &message) != 0)  {
                spa_close(spa, FTAG);
                return (SET_ERROR(EINVAL));
        }

        if (spa_version(spa) < SPA_VERSION_ZPOOL_HISTORY) {
                spa_close(spa, FTAG);
                return (SET_ERROR(ENOTSUP));
        }

        error = spa_history_log(spa, message);
        spa_close(spa, FTAG);
        return (error);
}

/*
 * The dp_config_rwlock must not be held when calling this, because the
 * unmount may need to write out data.
 *
 * This function is best-effort.  Callers must deal gracefully if it
 * remains mounted (or is remounted after this call).
 *
 * Returns 0 if the argument is not a snapshot, or it is not currently a
 * filesystem, or we were able to unmount it.  Returns error code otherwise.
 */
int
zfs_unmount_snap(const char *snapname)
{
        int err;

        if (strchr(snapname, '@') == NULL)
                return (0);

        err = zfsctl_snapshot_unmount((char *)snapname, MNT_FORCE);
        if (err != 0 && err != ENOENT)
                return (SET_ERROR(err));

        return (0);
}

/* ARGSUSED */
static int
zfs_unmount_snap_cb(const char *snapname, void *arg)
{
        return (zfs_unmount_snap(snapname));
}

/*
 * When a clone is destroyed, its origin may also need to be destroyed,
 * in which case it must be unmounted.  This routine will do that unmount
 * if necessary.
 */
void
zfs_destroy_unmount_origin(const char *fsname)
{
        int error;
        objset_t *os;
        dsl_dataset_t *ds;

        error = dmu_objset_hold(fsname, FTAG, &os);
        if (error != 0)
                return;
        ds = dmu_objset_ds(os);
        if (dsl_dir_is_clone(ds->ds_dir) && DS_IS_DEFER_DESTROY(ds->ds_prev)) {
                char originname[ZFS_MAX_DATASET_NAME_LEN];
                dsl_dataset_name(ds->ds_prev, originname);
                dmu_objset_rele(os, FTAG);
                (void) zfs_unmount_snap(originname);
        } else {
                dmu_objset_rele(os, FTAG);
        }
}

/*
 * innvl: {
 *     "snaps" -> { snapshot1, snapshot2 }
 *     (optional boolean) "defer"
 * }
 *
 * outnvl: snapshot -> error code (int32)
 */
/* ARGSUSED */
static int
zfs_ioc_destroy_snaps(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
{
        nvlist_t *snaps;
        nvpair_t *pair;
        boolean_t defer;

        if (nvlist_lookup_nvlist(innvl, "snaps", &snaps) != 0)
                return (SET_ERROR(EINVAL));
        defer = nvlist_exists(innvl, "defer");

        for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
            pair = nvlist_next_nvpair(snaps, pair)) {
                (void) zfs_unmount_snap(nvpair_name(pair));
        }

        return (dsl_destroy_snapshots_nvl(snaps, defer, outnvl));
}

/*
 * Create bookmarks.  Bookmark names are of the form <fs>#<bmark>.
 * All bookmarks must be in the same pool.
 *
 * innvl: {
 *     bookmark1 -> snapshot1, bookmark2 -> snapshot2
 * }
 *
 * outnvl: bookmark -> error code (int32)
 *
 */
/* ARGSUSED */
static int
zfs_ioc_bookmark(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
{
        nvpair_t *pair, *pair2;

        for (pair = nvlist_next_nvpair(innvl, NULL);
            pair != NULL; pair = nvlist_next_nvpair(innvl, pair)) {
                char *snap_name;

                /*
                 * Verify the snapshot argument.
                 */
                if (nvpair_value_string(pair, &snap_name) != 0)
                        return (SET_ERROR(EINVAL));


                /* Verify that the keys (bookmarks) are unique */
                for (pair2 = nvlist_next_nvpair(innvl, pair);
                    pair2 != NULL; pair2 = nvlist_next_nvpair(innvl, pair2)) {
                        if (strcmp(nvpair_name(pair), nvpair_name(pair2)) == 0)
                                return (SET_ERROR(EINVAL));
                }
        }

        return (dsl_bookmark_create(innvl, outnvl));
}

/*
 * innvl: {
 *     property 1, property 2, ...
 * }
 *
 * outnvl: {
 *     bookmark name 1 -> { property 1, property 2, ... },
 *     bookmark name 2 -> { property 1, property 2, ... }
 * }
 *
 */
static int
zfs_ioc_get_bookmarks(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
{
        return (dsl_get_bookmarks(fsname, innvl, outnvl));
}

/*
 * innvl: {
 *     bookmark name 1, bookmark name 2
 * }
 *
 * outnvl: bookmark -> error code (int32)
 *
 */
static int
zfs_ioc_destroy_bookmarks(const char *poolname, nvlist_t *innvl,
    nvlist_t *outnvl)
{
        int error, poollen;
        nvpair_t *pair;

        poollen = strlen(poolname);
        for (pair = nvlist_next_nvpair(innvl, NULL);
            pair != NULL; pair = nvlist_next_nvpair(innvl, pair)) {
                const char *name = nvpair_name(pair);
                const char *cp = strchr(name, '#');

                /*
                 * The bookmark name must contain an #, and the part after it
                 * must contain only valid characters.
                 */
                if (cp == NULL ||
                    zfs_component_namecheck(cp + 1, NULL, NULL) != 0)
                        return (SET_ERROR(EINVAL));

                /*
                 * The bookmark must be in the specified pool.
                 */
                if (strncmp(name, poolname, poollen) != 0 ||
                    (name[poollen] != '/' && name[poollen] != '#'))
                        return (SET_ERROR(EXDEV));
        }

        error = dsl_bookmark_destroy(innvl, outnvl);
        return (error);
}

/*
 * inputs:
 * zc_name              name of dataset to destroy
 * zc_objset_type       type of objset
 * zc_defer_destroy     mark for deferred destroy
 *
 * outputs:             none
 */
static int
zfs_ioc_destroy(zfs_cmd_t *zc)
{
        int err;

        if (zc->zc_objset_type == DMU_OST_ZFS) {
                err = zfs_unmount_snap(zc->zc_name);
                if (err != 0)
                        return (err);
        }

        if (strchr(zc->zc_name, '@')) {
                err = dsl_destroy_snapshot(zc->zc_name, zc->zc_defer_destroy);
        } else {
                err = dsl_destroy_head(zc->zc_name);
                if (err == EEXIST) {
                        /*
                         * It is possible that the given DS may have
                         * hidden child (%recv) datasets - "leftovers"
                         * resulting from the previously interrupted
                         * 'zfs receive'.
                         *
                         * 6 extra bytes for /%recv
                         */
                        char namebuf[ZFS_MAX_DATASET_NAME_LEN + 6];

                        (void) snprintf(namebuf, sizeof (namebuf),
                            "%s/%s", zc->zc_name, recv_clone_name);

                        /*
                         * Try to remove the hidden child (%recv) and after
                         * that try to remove the target dataset.
                         * If the hidden child (%recv) does not exist
                         * the original error (EEXIST) will be returned
                         */
                        err = dsl_destroy_head(namebuf);
                        if (err == 0)
                                err = dsl_destroy_head(zc->zc_name);
                        else if (err == ENOENT)
                                err = EEXIST;
                }
        }

        return (err);
}

/*
 * fsname is name of dataset to rollback (to most recent snapshot)
 *
 * innvl is not used.
 *
 * outnvl: "target" -> name of most recent snapshot
 * }
 */
/* ARGSUSED */
static int
zfs_ioc_rollback(const char *fsname, nvlist_t *args, nvlist_t *outnvl)
{
        zfs_sb_t *zsb;
        int error;

        if (get_zfs_sb(fsname, &zsb) == 0) {
                error = zfs_suspend_fs(zsb);
                if (error == 0) {
                        int resume_err;

                        error = dsl_dataset_rollback(fsname, zsb, outnvl);
                        resume_err = zfs_resume_fs(zsb, fsname);
                        error = error ? error : resume_err;
                }
                deactivate_super(zsb->z_sb);
        } else {
                error = dsl_dataset_rollback(fsname, NULL, outnvl);
        }
        return (error);
}

static int
recursive_unmount(const char *fsname, void *arg)
{
        const char *snapname = arg;
        char *fullname;
        int error;

        fullname = kmem_asprintf("%s@%s", fsname, snapname);
        error = zfs_unmount_snap(fullname);
        strfree(fullname);

        return (error);
}

/*
 * inputs:
 * zc_name      old name of dataset
 * zc_value     new name of dataset
 * zc_cookie    recursive flag (only valid for snapshots)
 *
 * outputs:     none
 */
static int
zfs_ioc_rename(zfs_cmd_t *zc)
{
        boolean_t recursive = zc->zc_cookie & 1;
        char *at;

        zc->zc_value[sizeof (zc->zc_value) - 1] = '\0';
        if (dataset_namecheck(zc->zc_value, NULL, NULL) != 0 ||
            strchr(zc->zc_value, '%'))
                return (SET_ERROR(EINVAL));

        at = strchr(zc->zc_name, '@');
        if (at != NULL) {
                /* snaps must be in same fs */
                int error;

                if (strncmp(zc->zc_name, zc->zc_value, at - zc->zc_name + 1))
                        return (SET_ERROR(EXDEV));
                *at = '\0';
                if (zc->zc_objset_type == DMU_OST_ZFS) {
                        error = dmu_objset_find(zc->zc_name,
                            recursive_unmount, at + 1,
                            recursive ? DS_FIND_CHILDREN : 0);
                        if (error != 0) {
                                *at = '@';
                                return (error);
                        }
                }
                error = dsl_dataset_rename_snapshot(zc->zc_name,
                    at + 1, strchr(zc->zc_value, '@') + 1, recursive);
                *at = '@';

                return (error);
        } else {
                return (dsl_dir_rename(zc->zc_name, zc->zc_value));
        }
}

static int
zfs_check_settable(const char *dsname, nvpair_t *pair, cred_t *cr)
{
        const char *propname = nvpair_name(pair);
        boolean_t issnap = (strchr(dsname, '@') != NULL);
        zfs_prop_t prop = zfs_name_to_prop(propname);
        uint64_t intval;
        int err;

        if (prop == ZPROP_INVAL) {
                if (zfs_prop_user(propname)) {
                        if ((err = zfs_secpolicy_write_perms(dsname,
                            ZFS_DELEG_PERM_USERPROP, cr)))
                                return (err);
                        return (0);
                }

                if (!issnap && zfs_prop_userquota(propname)) {
                        const char *perm = NULL;
                        const char *uq_prefix =
                            zfs_userquota_prop_prefixes[ZFS_PROP_USERQUOTA];
                        const char *gq_prefix =
                            zfs_userquota_prop_prefixes[ZFS_PROP_GROUPQUOTA];

                        if (strncmp(propname, uq_prefix,
                            strlen(uq_prefix)) == 0) {
                                perm = ZFS_DELEG_PERM_USERQUOTA;
                        } else if (strncmp(propname, gq_prefix,
                            strlen(gq_prefix)) == 0) {
                                perm = ZFS_DELEG_PERM_GROUPQUOTA;
                        } else {
                                /* USERUSED and GROUPUSED are read-only */
                                return (SET_ERROR(EINVAL));
                        }

                        if ((err = zfs_secpolicy_write_perms(dsname, perm, cr)))
                                return (err);
                        return (0);
                }

                return (SET_ERROR(EINVAL));
        }

        if (issnap)
                return (SET_ERROR(EINVAL));

        if (nvpair_type(pair) == DATA_TYPE_NVLIST) {
                /*
                 * dsl_prop_get_all_impl() returns properties in this
                 * format.
                 */
                nvlist_t *attrs;
                VERIFY(nvpair_value_nvlist(pair, &attrs) == 0);
                VERIFY(nvlist_lookup_nvpair(attrs, ZPROP_VALUE,
                    &pair) == 0);
        }

        /*
         * Check that this value is valid for this pool version
         */
        switch (prop) {
        case ZFS_PROP_COMPRESSION:
                /*
                 * If the user specified gzip compression, make sure
                 * the SPA supports it. We ignore any errors here since
                 * we'll catch them later.
                 */
                if (nvpair_value_uint64(pair, &intval) == 0) {
                        if (intval >= ZIO_COMPRESS_GZIP_1 &&
                            intval <= ZIO_COMPRESS_GZIP_9 &&
                            zfs_earlier_version(dsname,
                            SPA_VERSION_GZIP_COMPRESSION)) {
                                return (SET_ERROR(ENOTSUP));
                        }

                        if (intval == ZIO_COMPRESS_ZLE &&
                            zfs_earlier_version(dsname,
                            SPA_VERSION_ZLE_COMPRESSION))
                                return (SET_ERROR(ENOTSUP));

                        if (intval == ZIO_COMPRESS_LZ4) {
                                spa_t *spa;

                                if ((err = spa_open(dsname, &spa, FTAG)) != 0)
                                        return (err);

                                if (!spa_feature_is_enabled(spa,
                                    SPA_FEATURE_LZ4_COMPRESS)) {
                                        spa_close(spa, FTAG);
                                        return (SET_ERROR(ENOTSUP));
                                }
                                spa_close(spa, FTAG);
                        }

                        /*
                         * If this is a bootable dataset then
                         * verify that the compression algorithm
                         * is supported for booting. We must return
                         * something other than ENOTSUP since it
                         * implies a downrev pool version.
                         */
                        if (zfs_is_bootfs(dsname) &&
                            !BOOTFS_COMPRESS_VALID(intval)) {
                                return (SET_ERROR(ERANGE));
                        }
                }
                break;

        case ZFS_PROP_COPIES:
                if (zfs_earlier_version(dsname, SPA_VERSION_DITTO_BLOCKS))
                        return (SET_ERROR(ENOTSUP));
                break;

        case ZFS_PROP_DEDUP:
                if (zfs_earlier_version(dsname, SPA_VERSION_DEDUP))
                        return (SET_ERROR(ENOTSUP));
                break;

        case ZFS_PROP_VOLBLOCKSIZE:
        case ZFS_PROP_RECORDSIZE:
                /* Record sizes above 128k need the feature to be enabled */
                if (nvpair_value_uint64(pair, &intval) == 0 &&
                    intval > SPA_OLD_MAXBLOCKSIZE) {
                        spa_t *spa;

                        /*
                         * If this is a bootable dataset then
                         * we don't allow large (>128K) blocks,
                         * because GRUB doesn't support them.
                         */
                        if (zfs_is_bootfs(dsname) &&
                            intval > SPA_OLD_MAXBLOCKSIZE) {
                                return (SET_ERROR(ERANGE));
                        }

                        /*
                         * We don't allow setting the property above 1MB,
                         * unless the tunable has been changed.
                         */
                        if (intval > zfs_max_recordsize ||
                            intval > SPA_MAXBLOCKSIZE)
                                return (SET_ERROR(ERANGE));

                        if ((err = spa_open(dsname, &spa, FTAG)) != 0)
                                return (err);

                        if (!spa_feature_is_enabled(spa,
                            SPA_FEATURE_LARGE_BLOCKS)) {
                                spa_close(spa, FTAG);
                                return (SET_ERROR(ENOTSUP));
                        }
                        spa_close(spa, FTAG);
                }
                break;

        case ZFS_PROP_DNODESIZE:
                /* Dnode sizes above 512 need the feature to be enabled */
                if (nvpair_value_uint64(pair, &intval) == 0 &&
                    intval != ZFS_DNSIZE_LEGACY) {
                        spa_t *spa;

                        /*
                         * If this is a bootable dataset then
                         * we don't allow large (>512B) dnodes,
                         * because GRUB doesn't support them.
                         */
                        if (zfs_is_bootfs(dsname) &&
                                intval != ZFS_DNSIZE_LEGACY) {
                                return (SET_ERROR(EDOM));
                        }

                        if ((err = spa_open(dsname, &spa, FTAG)) != 0)
                                return (err);

                        if (!spa_feature_is_enabled(spa,
                            SPA_FEATURE_LARGE_DNODE)) {
                                spa_close(spa, FTAG);
                                return (SET_ERROR(ENOTSUP));
                        }
                        spa_close(spa, FTAG);
                }
                break;

        case ZFS_PROP_SHARESMB:
                if (zpl_earlier_version(dsname, ZPL_VERSION_FUID))
                        return (SET_ERROR(ENOTSUP));
                break;

        case ZFS_PROP_ACLINHERIT:
                if (nvpair_type(pair) == DATA_TYPE_UINT64 &&
                    nvpair_value_uint64(pair, &intval) == 0) {
                        if (intval == ZFS_ACL_PASSTHROUGH_X &&
                            zfs_earlier_version(dsname,
                            SPA_VERSION_PASSTHROUGH_X))
                                return (SET_ERROR(ENOTSUP));
                }
                break;
        default:
                break;
        }

        return (zfs_secpolicy_setprop(dsname, prop, pair, CRED()));
}

/*
 * Removes properties from the given props list that fail permission checks
 * needed to clear them and to restore them in case of a receive error. For each
 * property, make sure we have both set and inherit permissions.
 *
 * Returns the first error encountered if any permission checks fail. If the
 * caller provides a non-NULL errlist, it also gives the complete list of names
 * of all the properties that failed a permission check along with the
 * corresponding error numbers. The caller is responsible for freeing the
 * returned errlist.
 *
 * If every property checks out successfully, zero is returned and the list
 * pointed at by errlist is NULL.
 */
static int
zfs_check_clearable(char *dataset, nvlist_t *props, nvlist_t **errlist)
{
        zfs_cmd_t *zc;
        nvpair_t *pair, *next_pair;
        nvlist_t *errors;
        int err, rv = 0;

        if (props == NULL)
                return (0);

        VERIFY(nvlist_alloc(&errors, NV_UNIQUE_NAME, KM_SLEEP) == 0);

        zc = kmem_alloc(sizeof (zfs_cmd_t), KM_SLEEP);
        (void) strcpy(zc->zc_name, dataset);
        pair = nvlist_next_nvpair(props, NULL);
        while (pair != NULL) {
                next_pair = nvlist_next_nvpair(props, pair);

                (void) strcpy(zc->zc_value, nvpair_name(pair));
                if ((err = zfs_check_settable(dataset, pair, CRED())) != 0 ||
                    (err = zfs_secpolicy_inherit_prop(zc, NULL, CRED())) != 0) {
                        VERIFY(nvlist_remove_nvpair(props, pair) == 0);
                        VERIFY(nvlist_add_int32(errors,
                            zc->zc_value, err) == 0);
                }
                pair = next_pair;
        }
        kmem_free(zc, sizeof (zfs_cmd_t));

        if ((pair = nvlist_next_nvpair(errors, NULL)) == NULL) {
                nvlist_free(errors);
                errors = NULL;
        } else {
                VERIFY(nvpair_value_int32(pair, &rv) == 0);
        }

        if (errlist == NULL)
                nvlist_free(errors);
        else
                *errlist = errors;

        return (rv);
}

static boolean_t
propval_equals(nvpair_t *p1, nvpair_t *p2)
{
        if (nvpair_type(p1) == DATA_TYPE_NVLIST) {
                /* dsl_prop_get_all_impl() format */
                nvlist_t *attrs;
                VERIFY(nvpair_value_nvlist(p1, &attrs) == 0);
                VERIFY(nvlist_lookup_nvpair(attrs, ZPROP_VALUE,
                    &p1) == 0);
        }

        if (nvpair_type(p2) == DATA_TYPE_NVLIST) {
                nvlist_t *attrs;
                VERIFY(nvpair_value_nvlist(p2, &attrs) == 0);
                VERIFY(nvlist_lookup_nvpair(attrs, ZPROP_VALUE,
                    &p2) == 0);
        }

        if (nvpair_type(p1) != nvpair_type(p2))
                return (B_FALSE);

        if (nvpair_type(p1) == DATA_TYPE_STRING) {
                char *valstr1, *valstr2;

                VERIFY(nvpair_value_string(p1, (char **)&valstr1) == 0);
                VERIFY(nvpair_value_string(p2, (char **)&valstr2) == 0);
                return (strcmp(valstr1, valstr2) == 0);
        } else {
                uint64_t intval1, intval2;

                VERIFY(nvpair_value_uint64(p1, &intval1) == 0);
                VERIFY(nvpair_value_uint64(p2, &intval2) == 0);
                return (intval1 == intval2);
        }
}

/*
 * Remove properties from props if they are not going to change (as determined
 * by comparison with origprops). Remove them from origprops as well, since we
 * do not need to clear or restore properties that won't change.
 */
static void
props_reduce(nvlist_t *props, nvlist_t *origprops)
{
        nvpair_t *pair, *next_pair;

        if (origprops == NULL)
                return; /* all props need to be received */

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

                next_pair = nvlist_next_nvpair(props, pair);

                if ((nvlist_lookup_nvpair(origprops, propname,
                    &match) != 0) || !propval_equals(pair, match))
                        goto next; /* need to set received value */

                /* don't clear the existing received value */
                (void) nvlist_remove_nvpair(origprops, match);
                /* don't bother receiving the property */
                (void) nvlist_remove_nvpair(props, pair);
next:
                pair = next_pair;
        }
}

/*
 * Extract properties that cannot be set PRIOR to the receipt of a dataset.
 * For example, refquota cannot be set until after the receipt of a dataset,
 * because in replication streams, an older/earlier snapshot may exceed the
 * refquota.  We want to receive the older/earlier snapshot, but setting
 * refquota pre-receipt will set the dsl's ACTUAL quota, which will prevent
 * the older/earlier snapshot from being received (with EDQUOT).
 *
 * The ZFS test "zfs_receive_011_pos" demonstrates such a scenario.
 *
 * libzfs will need to be judicious handling errors encountered by props
 * extracted by this function.
 */
static nvlist_t *
extract_delay_props(nvlist_t *props)
{
        nvlist_t *delayprops;
        nvpair_t *nvp, *tmp;
        static const zfs_prop_t delayable[] = { ZFS_PROP_REFQUOTA, 0 };
        int i;

        VERIFY(nvlist_alloc(&delayprops, NV_UNIQUE_NAME, KM_SLEEP) == 0);

        for (nvp = nvlist_next_nvpair(props, NULL); nvp != NULL;
            nvp = nvlist_next_nvpair(props, nvp)) {
                /*
                 * strcmp() is safe because zfs_prop_to_name() always returns
                 * a bounded string.
                 */
                for (i = 0; delayable[i] != 0; i++) {
                        if (strcmp(zfs_prop_to_name(delayable[i]),
                            nvpair_name(nvp)) == 0) {
                                break;
                        }
                }
                if (delayable[i] != 0) {
                        tmp = nvlist_prev_nvpair(props, nvp);
                        VERIFY(nvlist_add_nvpair(delayprops, nvp) == 0);
                        VERIFY(nvlist_remove_nvpair(props, nvp) == 0);
                        nvp = tmp;
                }
        }

        if (nvlist_empty(delayprops)) {
                nvlist_free(delayprops);
                delayprops = NULL;
        }
        return (delayprops);
}

#ifdef  DEBUG
static boolean_t zfs_ioc_recv_inject_err;
#endif

/*
 * nvlist 'errors' is always allocated. It will contain descriptions of
 * encountered errors, if any. It's the callers responsibility to free.
 */
static int
zfs_ioc_recv_impl(char *tofs, char *tosnap, char *origin,
    nvlist_t *props, boolean_t force, boolean_t resumable, int input_fd,
    dmu_replay_record_t *begin_record, int cleanup_fd, uint64_t *read_bytes,
    uint64_t *errflags, uint64_t *action_handle, nvlist_t **errors)
{
        dmu_recv_cookie_t drc;
        int error = 0;
        int props_error = 0;
        offset_t off;
        nvlist_t *delayprops = NULL; /* sent properties applied post-receive */
        nvlist_t *origprops = NULL; /* existing properties */
        boolean_t first_recvd_props = B_FALSE;
        file_t *input_fp;

        *read_bytes = 0;
        *errflags = 0;
        *errors = fnvlist_alloc();

        input_fp = getf(input_fd);
        if (input_fp == NULL)
                return (SET_ERROR(EBADF));

        error = dmu_recv_begin(tofs, tosnap,
            begin_record, force, resumable, origin, &drc);
        if (error != 0)
                goto out;

        /*
         * Set properties before we receive the stream so that they are applied
         * to the new data. Note that we must call dmu_recv_stream() if
         * dmu_recv_begin() succeeds.
         */
        if (props != NULL && !drc.drc_newfs) {
                if (spa_version(dsl_dataset_get_spa(drc.drc_ds)) >=
                    SPA_VERSION_RECVD_PROPS &&
                    !dsl_prop_get_hasrecvd(tofs))
                        first_recvd_props = B_TRUE;

                /*
                 * If new received properties are supplied, they are to
                 * completely replace the existing received properties, so stash
                 * away the existing ones.
                 */
                if (dsl_prop_get_received(tofs, &origprops) == 0) {
                        nvlist_t *errlist = NULL;
                        /*
                         * Don't bother writing a property if its value won't
                         * change (and avoid the unnecessary security checks).
                         *
                         * The first receive after SPA_VERSION_RECVD_PROPS is a
                         * special case where we blow away all local properties
                         * regardless.
                         */
                        if (!first_recvd_props)
                                props_reduce(props, origprops);
                        if (zfs_check_clearable(tofs, origprops, &errlist) != 0)
                                (void) nvlist_merge(*errors, errlist, 0);
                        nvlist_free(errlist);

                        if (clear_received_props(tofs, origprops,
                            first_recvd_props ? NULL : props) != 0)
                                *errflags |= ZPROP_ERR_NOCLEAR;
                } else {
                        *errflags |= ZPROP_ERR_NOCLEAR;
                }
        }

        if (props != NULL) {
                props_error = dsl_prop_set_hasrecvd(tofs);

                if (props_error == 0) {
                        delayprops = extract_delay_props(props);
                        (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_RECEIVED,
                            props, *errors);
                }
        }

        off = input_fp->f_offset;
        error = dmu_recv_stream(&drc, input_fp->f_vnode, &off, cleanup_fd,
            action_handle);

        if (error == 0) {
                zfs_sb_t *zsb = NULL;

                if (get_zfs_sb(tofs, &zsb) == 0) {
                        /* online recv */
                        int end_err;

                        error = zfs_suspend_fs(zsb);
                        /*
                         * If the suspend fails, then the recv_end will
                         * likely also fail, and clean up after itself.
                         */
                        end_err = dmu_recv_end(&drc, zsb);
                        if (error == 0)
                                error = zfs_resume_fs(zsb, tofs);
                        error = error ? error : end_err;
                        deactivate_super(zsb->z_sb);
                } else {
                        error = dmu_recv_end(&drc, NULL);
                }

                /* Set delayed properties now, after we're done receiving. */
                if (delayprops != NULL && error == 0) {
                        (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_RECEIVED,
                            delayprops, *errors);
                }
        }

        if (delayprops != NULL) {
                /*
                 * Merge delayed props back in with initial props, in case
                 * we're DEBUG and zfs_ioc_recv_inject_err is set (which means
                 * we have to make sure clear_received_props() includes
                 * the delayed properties).
                 *
                 * Since zfs_ioc_recv_inject_err is only in DEBUG kernels,
                 * using ASSERT() will be just like a VERIFY.
                 */
                ASSERT(nvlist_merge(props, delayprops, 0) == 0);
                nvlist_free(delayprops);
        }


        *read_bytes = off - input_fp->f_offset;
        if (VOP_SEEK(input_fp->f_vnode, input_fp->f_offset, &off, NULL) == 0)
            input_fp->f_offset = off;

#ifdef  DEBUG
        if (zfs_ioc_recv_inject_err) {
                zfs_ioc_recv_inject_err = B_FALSE;
                error = 1;
        }
#endif

        /*
         * On error, restore the original props.
         */
        if (error != 0 && props != NULL && !drc.drc_newfs) {
                if (clear_received_props(tofs, props, NULL) != 0) {
                        /*
                         * We failed to clear the received properties.
                         * Since we may have left a $recvd value on the
                         * system, we can't clear the $hasrecvd flag.
                         */
                        *errflags |= ZPROP_ERR_NORESTORE;
                } else if (first_recvd_props) {
                        dsl_prop_unset_hasrecvd(tofs);
                }

                if (origprops == NULL && !drc.drc_newfs) {
                        /* We failed to stash the original properties. */
                        *errflags |= ZPROP_ERR_NORESTORE;
                }

                /*
                 * dsl_props_set() will not convert RECEIVED to LOCAL on or
                 * after SPA_VERSION_RECVD_PROPS, so we need to specify LOCAL
                 * explictly if we're restoring local properties cleared in the
                 * first new-style receive.
                 */
                if (origprops != NULL &&
                    zfs_set_prop_nvlist(tofs, (first_recvd_props ?
                    ZPROP_SRC_LOCAL : ZPROP_SRC_RECEIVED),
                    origprops, NULL) != 0) {
                        /*
                         * We stashed the original properties but failed to
                         * restore them.
                         */
                        *errflags |= ZPROP_ERR_NORESTORE;
                }
        }
out:
        releasef(input_fd);
        nvlist_free(origprops);

        if (error == 0)
                error = props_error;

        return (error);
}

/*
 * inputs:
 * zc_name              name of containing filesystem (unused)
 * zc_nvlist_src{_size} nvlist of properties to apply
 * zc_value             name of snapshot to create
 * zc_string            name of clone origin (if DRR_FLAG_CLONE)
 * zc_cookie            file descriptor to recv from
 * zc_begin_record      the BEGIN record of the stream (not byteswapped)
 * zc_guid              force flag
 * zc_cleanup_fd        cleanup-on-exit file descriptor
 * zc_action_handle     handle for this guid/ds mapping (or zero on first call)
 *
 * outputs:
 * zc_cookie            number of bytes read
 * zc_obj               zprop_errflags_t
 * zc_action_handle     handle for this guid/ds mapping
 * zc_nvlist_dst{_size} error for each unapplied received property
 */
static int
zfs_ioc_recv(zfs_cmd_t *zc)
{
        dmu_replay_record_t begin_record;
        nvlist_t *errors = NULL;
        nvlist_t *props = NULL;
        char *origin = NULL;
        char *tosnap;
        char tofs[ZFS_MAX_DATASET_NAME_LEN];
        int error = 0;

        if (dataset_namecheck(zc->zc_value, NULL, NULL) != 0 ||
            strchr(zc->zc_value, '@') == NULL ||
            strchr(zc->zc_value, '%'))
                return (SET_ERROR(EINVAL));

        (void) strlcpy(tofs, zc->zc_value, sizeof (tofs));
        tosnap = strchr(tofs, '@');
        *tosnap++ = '\0';

        if (zc->zc_nvlist_src != 0 &&
            (error = get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
            zc->zc_iflags, &props)) != 0)
                return (error);

        if (zc->zc_string[0])
                origin = zc->zc_string;

        begin_record.drr_type = DRR_BEGIN;
        begin_record.drr_payloadlen = 0;
        begin_record.drr_u.drr_begin = zc->zc_begin_record;

        error = zfs_ioc_recv_impl(tofs, tosnap, origin, props, zc->zc_guid,
            B_FALSE, zc->zc_cookie, &begin_record, zc->zc_cleanup_fd,
            &zc->zc_cookie, &zc->zc_obj, &zc->zc_action_handle, &errors);
        nvlist_free(props);

        /*
         * Now that all props, initial and delayed, are set, report the prop
         * errors to the caller.
         */
        if (zc->zc_nvlist_dst_size != 0 && errors != NULL &&
            (nvlist_smush(errors, zc->zc_nvlist_dst_size) != 0 ||
            put_nvlist(zc, errors) != 0)) {
                /*
                 * Caller made zc->zc_nvlist_dst less than the minimum expected
                 * size or supplied an invalid address.
                 */
                error = SET_ERROR(EINVAL);
        }

        nvlist_free(errors);

        return (error);
}

/*
 * innvl: {
 *     "snapname" -> full name of the snapshot to create
 *     (optional) "props" -> properties to set (nvlist)
 *     (optional) "origin" -> name of clone origin (DRR_FLAG_CLONE)
 *     "begin_record" -> non-byteswapped dmu_replay_record_t
 *     "input_fd" -> file descriptor to read stream from (int32)
 *     (optional) "force" -> force flag (value ignored)
 *     (optional) "resumable" -> resumable flag (value ignored)
 *     (optional) "cleanup_fd" -> cleanup-on-exit file descriptor
 *     (optional) "action_handle" -> handle for this guid/ds mapping
 * }
 *
 * outnvl: {
 *     "read_bytes" -> number of bytes read
 *     "error_flags" -> zprop_errflags_t
 *     "action_handle" -> handle for this guid/ds mapping
 *     "errors" -> error for each unapplied received property (nvlist)
 * }
 */
static int
zfs_ioc_recv_new(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
{
        dmu_replay_record_t *begin_record;
        uint_t begin_record_size;
        nvlist_t *errors = NULL;
        nvlist_t *props = NULL;
        char *snapname = NULL;
        char *origin = NULL;
        char *tosnap;
        char tofs[ZFS_MAX_DATASET_NAME_LEN];
        boolean_t force;
        boolean_t resumable;
        uint64_t action_handle = 0;
        uint64_t read_bytes = 0;
        uint64_t errflags = 0;
        int input_fd = -1;
        int cleanup_fd = -1;
        int error;

        error = nvlist_lookup_string(innvl, "snapname", &snapname);
        if (error != 0)
                return (SET_ERROR(EINVAL));

        if (dataset_namecheck(snapname, NULL, NULL) != 0 ||
            strchr(snapname, '@') == NULL ||
            strchr(snapname, '%'))
                return (SET_ERROR(EINVAL));

        (void) strcpy(tofs, snapname);
        tosnap = strchr(tofs, '@');
        *tosnap++ = '\0';

        error = nvlist_lookup_string(innvl, "origin", &origin);
        if (error && error != ENOENT)
                return (error);

        error = nvlist_lookup_byte_array(innvl, "begin_record",
            (uchar_t **) &begin_record, &begin_record_size);
        if (error != 0 || begin_record_size != sizeof (*begin_record))
                return (SET_ERROR(EINVAL));

        error = nvlist_lookup_int32(innvl, "input_fd", &input_fd);
        if (error != 0)
                return (SET_ERROR(EINVAL));

        force = nvlist_exists(innvl, "force");
        resumable = nvlist_exists(innvl, "resumable");

        error = nvlist_lookup_int32(innvl, "cleanup_fd", &cleanup_fd);
        if (error && error != ENOENT)
                return (error);

        error = nvlist_lookup_uint64(innvl, "action_handle", &action_handle);
        if (error && error != ENOENT)
                return (error);

        error = nvlist_lookup_nvlist(innvl, "props", &props);
        if (error && error != ENOENT)
                return (error);

        error = zfs_ioc_recv_impl(tofs, tosnap, origin, props, force,
            resumable, input_fd, begin_record, cleanup_fd, &read_bytes,
            &errflags, &action_handle, &errors);

        fnvlist_add_uint64(outnvl, "read_bytes", read_bytes);
        fnvlist_add_uint64(outnvl, "error_flags", errflags);
        fnvlist_add_uint64(outnvl, "action_handle", action_handle);
        fnvlist_add_nvlist(outnvl, "errors", errors);

        nvlist_free(errors);
        nvlist_free(props);

        return (error);
}

/*
 * inputs:
 * zc_name      name of snapshot to send
 * zc_cookie    file descriptor to send stream to
 * zc_obj       fromorigin flag (mutually exclusive with zc_fromobj)
 * zc_sendobj   objsetid of snapshot to send
 * zc_fromobj   objsetid of incremental fromsnap (may be zero)
 * zc_guid      if set, estimate size of stream only.  zc_cookie is ignored.
 *              output size in zc_objset_type.
 * zc_flags     lzc_send_flags
 *
 * outputs:
 * zc_objset_type       estimated size, if zc_guid is set
 */
static int
zfs_ioc_send(zfs_cmd_t *zc)
{
        int error;
        offset_t off;
        boolean_t estimate = (zc->zc_guid != 0);
        boolean_t embedok = (zc->zc_flags & 0x1);
        boolean_t large_block_ok = (zc->zc_flags & 0x2);
        boolean_t compressok = (zc->zc_flags & 0x4);

        if (zc->zc_obj != 0) {
                dsl_pool_t *dp;
                dsl_dataset_t *tosnap;

                error = dsl_pool_hold(zc->zc_name, FTAG, &dp);
                if (error != 0)
                        return (error);

                error = dsl_dataset_hold_obj(dp, zc->zc_sendobj, FTAG, &tosnap);
                if (error != 0) {
                        dsl_pool_rele(dp, FTAG);
                        return (error);
                }

                if (dsl_dir_is_clone(tosnap->ds_dir))
                        zc->zc_fromobj =
                            dsl_dir_phys(tosnap->ds_dir)->dd_origin_obj;
                dsl_dataset_rele(tosnap, FTAG);
                dsl_pool_rele(dp, FTAG);
        }

        if (estimate) {
                dsl_pool_t *dp;
                dsl_dataset_t *tosnap;
                dsl_dataset_t *fromsnap = NULL;

                error = dsl_pool_hold(zc->zc_name, FTAG, &dp);
                if (error != 0)
                        return (error);

                error = dsl_dataset_hold_obj(dp, zc->zc_sendobj, FTAG, &tosnap);
                if (error != 0) {
                        dsl_pool_rele(dp, FTAG);
                        return (error);
                }

                if (zc->zc_fromobj != 0) {
                        error = dsl_dataset_hold_obj(dp, zc->zc_fromobj,
                            FTAG, &fromsnap);
                        if (error != 0) {
                                dsl_dataset_rele(tosnap, FTAG);
                                dsl_pool_rele(dp, FTAG);
                                return (error);
                        }
                }

                error = dmu_send_estimate(tosnap, fromsnap, compressok,
                    &zc->zc_objset_type);

                if (fromsnap != NULL)
                        dsl_dataset_rele(fromsnap, FTAG);
                dsl_dataset_rele(tosnap, FTAG);
                dsl_pool_rele(dp, FTAG);
        } else {
                file_t *fp = getf(zc->zc_cookie);
                if (fp == NULL)
                        return (SET_ERROR(EBADF));

                off = fp->f_offset;
                error = dmu_send_obj(zc->zc_name, zc->zc_sendobj,
                    zc->zc_fromobj, embedok, large_block_ok, compressok,
                    zc->zc_cookie, fp->f_vnode, &off);

                if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
                        fp->f_offset = off;
                releasef(zc->zc_cookie);
        }
        return (error);
}

/*
 * inputs:
 * zc_name      name of snapshot on which to report progress
 * zc_cookie    file descriptor of send stream
 *
 * outputs:
 * zc_cookie    number of bytes written in send stream thus far
 */
static int
zfs_ioc_send_progress(zfs_cmd_t *zc)
{
        dsl_pool_t *dp;
        dsl_dataset_t *ds;
        dmu_sendarg_t *dsp = NULL;
        int error;

        error = dsl_pool_hold(zc->zc_name, FTAG, &dp);
        if (error != 0)
                return (error);

        error = dsl_dataset_hold(dp, zc->zc_name, FTAG, &ds);
        if (error != 0) {
                dsl_pool_rele(dp, FTAG);
                return (error);
        }

        mutex_enter(&ds->ds_sendstream_lock);

        /*
         * Iterate over all the send streams currently active on this dataset.
         * If there's one which matches the specified file descriptor _and_ the
         * stream was started by the current process, return the progress of
         * that stream.
         */

        for (dsp = list_head(&ds->ds_sendstreams); dsp != NULL;
            dsp = list_next(&ds->ds_sendstreams, dsp)) {
                if (dsp->dsa_outfd == zc->zc_cookie &&
                    dsp->dsa_proc->group_leader == curproc->group_leader)
                        break;
        }

        if (dsp != NULL)
                zc->zc_cookie = *(dsp->dsa_off);
        else
                error = SET_ERROR(ENOENT);

        mutex_exit(&ds->ds_sendstream_lock);
        dsl_dataset_rele(ds, FTAG);
        dsl_pool_rele(dp, FTAG);
        return (error);
}

static int
zfs_ioc_inject_fault(zfs_cmd_t *zc)
{
        int id, error;

        error = zio_inject_fault(zc->zc_name, (int)zc->zc_guid, &id,
            &zc->zc_inject_record);

        if (error == 0)
                zc->zc_guid = (uint64_t)id;

        return (error);
}

static int
zfs_ioc_clear_fault(zfs_cmd_t *zc)
{
        return (zio_clear_fault((int)zc->zc_guid));
}

static int
zfs_ioc_inject_list_next(zfs_cmd_t *zc)
{
        int id = (int)zc->zc_guid;
        int error;

        error = zio_inject_list_next(&id, zc->zc_name, sizeof (zc->zc_name),
            &zc->zc_inject_record);

        zc->zc_guid = id;

        return (error);
}

static int
zfs_ioc_error_log(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;
        size_t count = (size_t)zc->zc_nvlist_dst_size;

        if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                return (error);

        error = spa_get_errlog(spa, (void *)(uintptr_t)zc->zc_nvlist_dst,
            &count);
        if (error == 0)
                zc->zc_nvlist_dst_size = count;
        else
                zc->zc_nvlist_dst_size = spa_get_errlog_size(spa);

        spa_close(spa, FTAG);

        return (error);
}

static int
zfs_ioc_clear(zfs_cmd_t *zc)
{
        spa_t *spa;
        vdev_t *vd;
        int error;

        /*
         * On zpool clear we also fix up missing slogs
         */
        mutex_enter(&spa_namespace_lock);
        spa = spa_lookup(zc->zc_name);
        if (spa == NULL) {
                mutex_exit(&spa_namespace_lock);
                return (SET_ERROR(EIO));
        }
        if (spa_get_log_state(spa) == SPA_LOG_MISSING) {
                /* we need to let spa_open/spa_load clear the chains */
                spa_set_log_state(spa, SPA_LOG_CLEAR);
        }
        spa->spa_last_open_failed = 0;
        mutex_exit(&spa_namespace_lock);

        if (zc->zc_cookie & ZPOOL_NO_REWIND) {
                error = spa_open(zc->zc_name, &spa, FTAG);
        } else {
                nvlist_t *policy;
                nvlist_t *config = NULL;

                if (zc->zc_nvlist_src == 0)
                        return (SET_ERROR(EINVAL));

                if ((error = get_nvlist(zc->zc_nvlist_src,
                    zc->zc_nvlist_src_size, zc->zc_iflags, &policy)) == 0) {
                        error = spa_open_rewind(zc->zc_name, &spa, FTAG,
                            policy, &config);
                        if (config != NULL) {
                                int err;

                                if ((err = put_nvlist(zc, config)) != 0)
                                        error = err;
                                nvlist_free(config);
                        }
                        nvlist_free(policy);
                }
        }

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

        spa_vdev_state_enter(spa, SCL_NONE);

        if (zc->zc_guid == 0) {
                vd = NULL;
        } else {
                vd = spa_lookup_by_guid(spa, zc->zc_guid, B_TRUE);
                if (vd == NULL) {
                        (void) spa_vdev_state_exit(spa, NULL, ENODEV);
                        spa_close(spa, FTAG);
                        return (SET_ERROR(ENODEV));
                }
        }

        vdev_clear(spa, vd);

        (void) spa_vdev_state_exit(spa, NULL, 0);

        /*
         * Resume any suspended I/Os.
         */
        if (zio_resume(spa) != 0)
                error = SET_ERROR(EIO);

        spa_close(spa, FTAG);

        return (error);
}

static int
zfs_ioc_pool_reopen(zfs_cmd_t *zc)
{
        spa_t *spa;
        int error;

        error = spa_open(zc->zc_name, &spa, FTAG);
        if (error != 0)
                return (error);

        spa_vdev_state_enter(spa, SCL_NONE);

        /*
         * If a resilver is already in progress then set the
         * spa_scrub_reopen flag to B_TRUE so that we don't restart
         * the scan as a side effect of the reopen. Otherwise, let
         * vdev_open() decided if a resilver is required.
         */
        spa->spa_scrub_reopen = dsl_scan_resilvering(spa->spa_dsl_pool);
        vdev_reopen(spa->spa_root_vdev);
        spa->spa_scrub_reopen = B_FALSE;

        (void) spa_vdev_state_exit(spa, NULL, 0);
        spa_close(spa, FTAG);
        return (0);
}
/*
 * inputs:
 * zc_name      name of filesystem
 * zc_value     name of origin snapshot
 *
 * outputs:
 * zc_string    name of conflicting snapshot, if there is one
 */
static int
zfs_ioc_promote(zfs_cmd_t *zc)
{
        char *cp;

        /*
         * We don't need to unmount *all* the origin fs's snapshots, but
         * it's easier.
         */
        cp = strchr(zc->zc_value, '@');
        if (cp)
                *cp = '\0';
        (void) dmu_objset_find(zc->zc_value,
            zfs_unmount_snap_cb, NULL, DS_FIND_SNAPSHOTS);
        return (dsl_dataset_promote(zc->zc_name, zc->zc_string));
}

/*
 * Retrieve a single {user|group}{used|quota}@... property.
 *
 * inputs:
 * zc_name      name of filesystem
 * zc_objset_type zfs_userquota_prop_t
 * zc_value     domain name (eg. "S-1-234-567-89")
 * zc_guid      RID/UID/GID
 *
 * outputs:
 * zc_cookie    property value
 */
static int
zfs_ioc_userspace_one(zfs_cmd_t *zc)
{
        zfs_sb_t *zsb;
        int error;

        if (zc->zc_objset_type >= ZFS_NUM_USERQUOTA_PROPS)
                return (SET_ERROR(EINVAL));

        error = zfs_sb_hold(zc->zc_name, FTAG, &zsb, B_FALSE);
        if (error != 0)
                return (error);

        error = zfs_userspace_one(zsb,
            zc->zc_objset_type, zc->zc_value, zc->zc_guid, &zc->zc_cookie);
        zfs_sb_rele(zsb, FTAG);

        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_cookie            zap cursor
 * zc_objset_type       zfs_userquota_prop_t
 * zc_nvlist_dst[_size] buffer to fill (not really an nvlist)
 *
 * outputs:
 * zc_nvlist_dst[_size] data buffer (array of zfs_useracct_t)
 * zc_cookie    zap cursor
 */
static int
zfs_ioc_userspace_many(zfs_cmd_t *zc)
{
        zfs_sb_t *zsb;
        int bufsize = zc->zc_nvlist_dst_size;
        int error;
        void *buf;

        if (bufsize <= 0)
                return (SET_ERROR(ENOMEM));

        error = zfs_sb_hold(zc->zc_name, FTAG, &zsb, B_FALSE);
        if (error != 0)
                return (error);

        buf = vmem_alloc(bufsize, KM_SLEEP);

        error = zfs_userspace_many(zsb, zc->zc_objset_type, &zc->zc_cookie,
            buf, &zc->zc_nvlist_dst_size);

        if (error == 0) {
                error = xcopyout(buf,
                    (void *)(uintptr_t)zc->zc_nvlist_dst,
                    zc->zc_nvlist_dst_size);
        }
        vmem_free(buf, bufsize);
        zfs_sb_rele(zsb, FTAG);

        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 *
 * outputs:
 * none
 */
static int
zfs_ioc_userspace_upgrade(zfs_cmd_t *zc)
{
        objset_t *os;
        int error = 0;
        zfs_sb_t *zsb;

        if (get_zfs_sb(zc->zc_name, &zsb) == 0) {
                if (!dmu_objset_userused_enabled(zsb->z_os)) {
                        /*
                         * If userused is not enabled, it may be because the
                         * objset needs to be closed & reopened (to grow the
                         * objset_phys_t).  Suspend/resume the fs will do that.
                         */
                        error = zfs_suspend_fs(zsb);
                        if (error == 0) {
                                dmu_objset_refresh_ownership(zsb->z_os,
                                    zsb);
                                error = zfs_resume_fs(zsb, zc->zc_name);
                        }
                }
                if (error == 0)
                        error = dmu_objset_userspace_upgrade(zsb->z_os);
                deactivate_super(zsb->z_sb);
        } else {
                /* XXX kind of reading contents without owning */
                error = dmu_objset_hold(zc->zc_name, FTAG, &os);
                if (error != 0)
                        return (error);

                error = dmu_objset_userspace_upgrade(os);
                dmu_objset_rele(os, FTAG);
        }

        return (error);
}

static int
zfs_ioc_share(zfs_cmd_t *zc)
{
        return (SET_ERROR(ENOSYS));
}

ace_t full_access[] = {
        {(uid_t)-1, ACE_ALL_PERMS, ACE_EVERYONE, 0}
};

/*
 * inputs:
 * zc_name              name of containing filesystem
 * zc_obj               object # beyond which we want next in-use object #
 *
 * outputs:
 * zc_obj               next in-use object #
 */
static int
zfs_ioc_next_obj(zfs_cmd_t *zc)
{
        objset_t *os = NULL;
        int error;

        error = dmu_objset_hold(zc->zc_name, FTAG, &os);
        if (error != 0)
                return (error);

        error = dmu_object_next(os, &zc->zc_obj, B_FALSE, 0);

        dmu_objset_rele(os, FTAG);
        return (error);
}

/*
 * inputs:
 * zc_name              name of filesystem
 * zc_value             prefix name for snapshot
 * zc_cleanup_fd        cleanup-on-exit file descriptor for calling process
 *
 * outputs:
 * zc_value             short name of new snapshot
 */
static int
zfs_ioc_tmp_snapshot(zfs_cmd_t *zc)
{
        char *snap_name;
        char *hold_name;
        int error;
        minor_t minor;

        error = zfs_onexit_fd_hold(zc->zc_cleanup_fd, &minor);
        if (error != 0)
                return (error);

        snap_name = kmem_asprintf("%s-%016llx", zc->zc_value,
            (u_longlong_t)ddi_get_lbolt64());
        hold_name = kmem_asprintf("%%%s", zc->zc_value);

        error = dsl_dataset_snapshot_tmp(zc->zc_name, snap_name, minor,
            hold_name);
        if (error == 0)
                (void) strcpy(zc->zc_value, snap_name);
        strfree(snap_name);
        strfree(hold_name);
        zfs_onexit_fd_rele(zc->zc_cleanup_fd);
        return (error);
}

/*
 * inputs:
 * zc_name              name of "to" snapshot
 * zc_value             name of "from" snapshot
 * zc_cookie            file descriptor to write diff data on
 *
 * outputs:
 * dmu_diff_record_t's to the file descriptor
 */
static int
zfs_ioc_diff(zfs_cmd_t *zc)
{
        file_t *fp;
        offset_t off;
        int error;

        fp = getf(zc->zc_cookie);
        if (fp == NULL)
                return (SET_ERROR(EBADF));

        off = fp->f_offset;

        error = dmu_diff(zc->zc_name, zc->zc_value, fp->f_vnode, &off);

        if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
                fp->f_offset = off;
        releasef(zc->zc_cookie);

        return (error);
}

/*
 * Remove all ACL files in shares dir
 */
#ifdef HAVE_SMB_SHARE
static int
zfs_smb_acl_purge(znode_t *dzp)
{
        zap_cursor_t    zc;
        zap_attribute_t zap;
        zfs_sb_t *zsb = ZTOZSB(dzp);
        int error;

        for (zap_cursor_init(&zc, zsb->z_os, dzp->z_id);
            (error = zap_cursor_retrieve(&zc, &zap)) == 0;
            zap_cursor_advance(&zc)) {
                if ((error = VOP_REMOVE(ZTOV(dzp), zap.za_name, kcred,
                    NULL, 0)) != 0)
                        break;
        }
        zap_cursor_fini(&zc);
        return (error);
}
#endif /* HAVE_SMB_SHARE */

static int
zfs_ioc_smb_acl(zfs_cmd_t *zc)
{
#ifdef HAVE_SMB_SHARE
        vnode_t *vp;
        znode_t *dzp;
        vnode_t *resourcevp = NULL;
        znode_t *sharedir;
        zfs_sb_t *zsb;
        nvlist_t *nvlist;
        char *src, *target;
        vattr_t vattr;
        vsecattr_t vsec;
        int error = 0;

        if ((error = lookupname(zc->zc_value, UIO_SYSSPACE,
            NO_FOLLOW, NULL, &vp)) != 0)
                return (error);

        /* Now make sure mntpnt and dataset are ZFS */

        if (vp->v_vfsp->vfs_fstype != zfsfstype ||
            (strcmp((char *)refstr_value(vp->v_vfsp->vfs_resource),
            zc->zc_name) != 0)) {
                VN_RELE(vp);
                return (SET_ERROR(EINVAL));
        }

        dzp = VTOZ(vp);
        zsb = ZTOZSB(dzp);
        ZFS_ENTER(zsb);

        /*
         * Create share dir if its missing.
         */
        mutex_enter(&zsb->z_lock);
        if (zsb->z_shares_dir == 0) {
                dmu_tx_t *tx;

                tx = dmu_tx_create(zsb->z_os);
                dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, TRUE,
                    ZFS_SHARES_DIR);
                dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
                error = dmu_tx_assign(tx, TXG_WAIT);
                if (error != 0) {
                        dmu_tx_abort(tx);
                } else {
                        error = zfs_create_share_dir(zsb, tx);
                        dmu_tx_commit(tx);
                }
                if (error != 0) {
                        mutex_exit(&zsb->z_lock);
                        VN_RELE(vp);
                        ZFS_EXIT(zsb);
                        return (error);
                }
        }
        mutex_exit(&zsb->z_lock);

        ASSERT(zsb->z_shares_dir);
        if ((error = zfs_zget(zsb, zsb->z_shares_dir, &sharedir)) != 0) {
                VN_RELE(vp);
                ZFS_EXIT(zsb);
                return (error);
        }

        switch (zc->zc_cookie) {
        case ZFS_SMB_ACL_ADD:
                vattr.va_mask = AT_MODE|AT_UID|AT_GID|AT_TYPE;
                vattr.va_mode = S_IFREG|0777;
                vattr.va_uid = 0;
                vattr.va_gid = 0;

                vsec.vsa_mask = VSA_ACE;
                vsec.vsa_aclentp = &full_access;
                vsec.vsa_aclentsz = sizeof (full_access);
                vsec.vsa_aclcnt = 1;

                error = VOP_CREATE(ZTOV(sharedir), zc->zc_string,
                    &vattr, EXCL, 0, &resourcevp, kcred, 0, NULL, &vsec);
                if (resourcevp)
                        VN_RELE(resourcevp);
                break;

        case ZFS_SMB_ACL_REMOVE:
                error = VOP_REMOVE(ZTOV(sharedir), zc->zc_string, kcred,
                    NULL, 0);
                break;

        case ZFS_SMB_ACL_RENAME:
                if ((error = get_nvlist(zc->zc_nvlist_src,
                    zc->zc_nvlist_src_size, zc->zc_iflags, &nvlist)) != 0) {
                        VN_RELE(vp);
                        VN_RELE(ZTOV(sharedir));
                        ZFS_EXIT(zsb);
                        return (error);
                }
                if (nvlist_lookup_string(nvlist, ZFS_SMB_ACL_SRC, &src) ||
                    nvlist_lookup_string(nvlist, ZFS_SMB_ACL_TARGET,
                    &target)) {
                        VN_RELE(vp);
                        VN_RELE(ZTOV(sharedir));
                        ZFS_EXIT(zsb);
                        nvlist_free(nvlist);
                        return (error);
                }
                error = VOP_RENAME(ZTOV(sharedir), src, ZTOV(sharedir), target,
                    kcred, NULL, 0);
                nvlist_free(nvlist);
                break;

        case ZFS_SMB_ACL_PURGE:
                error = zfs_smb_acl_purge(sharedir);
                break;

        default:
                error = SET_ERROR(EINVAL);
                break;
        }

        VN_RELE(vp);
        VN_RELE(ZTOV(sharedir));

        ZFS_EXIT(zsb);

        return (error);
#else
        return (SET_ERROR(ENOTSUP));
#endif /* HAVE_SMB_SHARE */
}

/*
 * innvl: {
 *     "holds" -> { snapname -> holdname (string), ... }
 *     (optional) "cleanup_fd" -> fd (int32)
 * }
 *
 * outnvl: {
 *     snapname -> error value (int32)
 *     ...
 * }
 */
/* ARGSUSED */
static int
zfs_ioc_hold(const char *pool, nvlist_t *args, nvlist_t *errlist)
{
        nvpair_t *pair;
        nvlist_t *holds;
        int cleanup_fd = -1;
        int error;
        minor_t minor = 0;

        error = nvlist_lookup_nvlist(args, "holds", &holds);
        if (error != 0)
                return (SET_ERROR(EINVAL));

        /* make sure the user didn't pass us any invalid (empty) tags */
        for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
            pair = nvlist_next_nvpair(holds, pair)) {
                char *htag;

                error = nvpair_value_string(pair, &htag);
                if (error != 0)
                        return (SET_ERROR(error));

                if (strlen(htag) == 0)
                        return (SET_ERROR(EINVAL));
        }

        if (nvlist_lookup_int32(args, "cleanup_fd", &cleanup_fd) == 0) {
                error = zfs_onexit_fd_hold(cleanup_fd, &minor);
                if (error != 0)
                        return (error);
        }

        error = dsl_dataset_user_hold(holds, minor, errlist);
        if (minor != 0)
                zfs_onexit_fd_rele(cleanup_fd);
        return (error);
}

/*
 * innvl is not used.
 *
 * outnvl: {
 *    holdname -> time added (uint64 seconds since epoch)
 *    ...
 * }
 */
/* ARGSUSED */
static int
zfs_ioc_get_holds(const char *snapname, nvlist_t *args, nvlist_t *outnvl)
{
        return (dsl_dataset_get_holds(snapname, outnvl));
}

/*
 * innvl: {
 *     snapname -> { holdname, ... }
 *     ...
 * }
 *
 * outnvl: {
 *     snapname -> error value (int32)
 *     ...
 * }
 */
/* ARGSUSED */
static int
zfs_ioc_release(const char *pool, nvlist_t *holds, nvlist_t *errlist)
{
        return (dsl_dataset_user_release(holds, errlist));
}

/*
 * inputs:
 * zc_guid              flags (ZEVENT_NONBLOCK)
 * zc_cleanup_fd        zevent file descriptor
 *
 * outputs:
 * zc_nvlist_dst        next nvlist event
 * zc_cookie            dropped events since last get
 */
static int
zfs_ioc_events_next(zfs_cmd_t *zc)
{
        zfs_zevent_t *ze;
        nvlist_t *event = NULL;
        minor_t minor;
        uint64_t dropped = 0;
        int error;

        error = zfs_zevent_fd_hold(zc->zc_cleanup_fd, &minor, &ze);
        if (error != 0)
                return (error);

        do {
                error = zfs_zevent_next(ze, &event,
                        &zc->zc_nvlist_dst_size, &dropped);
                if (event != NULL) {
                        zc->zc_cookie = dropped;
                        error = put_nvlist(zc, event);
                        nvlist_free(event);
                }

                if (zc->zc_guid & ZEVENT_NONBLOCK)
                        break;

                if ((error == 0) || (error != ENOENT))
                        break;

                error = zfs_zevent_wait(ze);
                if (error != 0)
                        break;
        } while (1);

        zfs_zevent_fd_rele(zc->zc_cleanup_fd);

        return (error);
}

/*
 * outputs:
 * zc_cookie            cleared events count
 */
static int
zfs_ioc_events_clear(zfs_cmd_t *zc)
{
        int count;

        zfs_zevent_drain_all(&count);
        zc->zc_cookie = count;

        return (0);
}

/*
 * inputs:
 * zc_guid              eid | ZEVENT_SEEK_START | ZEVENT_SEEK_END
 * zc_cleanup           zevent file descriptor
 */
static int
zfs_ioc_events_seek(zfs_cmd_t *zc)
{
        zfs_zevent_t *ze;
        minor_t minor;
        int error;

        error = zfs_zevent_fd_hold(zc->zc_cleanup_fd, &minor, &ze);
        if (error != 0)
                return (error);

        error = zfs_zevent_seek(ze, zc->zc_guid);
        zfs_zevent_fd_rele(zc->zc_cleanup_fd);

        return (error);
}

/*
 * inputs:
 * zc_name              name of new filesystem or snapshot
 * zc_value             full name of old snapshot
 *
 * outputs:
 * zc_cookie            space in bytes
 * zc_objset_type       compressed space in bytes
 * zc_perm_action       uncompressed space in bytes
 */
static int
zfs_ioc_space_written(zfs_cmd_t *zc)
{
        int error;
        dsl_pool_t *dp;
        dsl_dataset_t *new, *old;

        error = dsl_pool_hold(zc->zc_name, FTAG, &dp);
        if (error != 0)
                return (error);
        error = dsl_dataset_hold(dp, zc->zc_name, FTAG, &new);
        if (error != 0) {
                dsl_pool_rele(dp, FTAG);
                return (error);
        }
        error = dsl_dataset_hold(dp, zc->zc_value, FTAG, &old);
        if (error != 0) {
                dsl_dataset_rele(new, FTAG);
                dsl_pool_rele(dp, FTAG);
                return (error);
        }

        error = dsl_dataset_space_written(old, new, &zc->zc_cookie,
            &zc->zc_objset_type, &zc->zc_perm_action);
        dsl_dataset_rele(old, FTAG);
        dsl_dataset_rele(new, FTAG);
        dsl_pool_rele(dp, FTAG);
        return (error);
}

/*
 * innvl: {
 *     "firstsnap" -> snapshot name
 * }
 *
 * outnvl: {
 *     "used" -> space in bytes
 *     "compressed" -> compressed space in bytes
 *     "uncompressed" -> uncompressed space in bytes
 * }
 */
static int
zfs_ioc_space_snaps(const char *lastsnap, nvlist_t *innvl, nvlist_t *outnvl)
{
        int error;
        dsl_pool_t *dp;
        dsl_dataset_t *new, *old;
        char *firstsnap;
        uint64_t used, comp, uncomp;

        if (nvlist_lookup_string(innvl, "firstsnap", &firstsnap) != 0)
                return (SET_ERROR(EINVAL));

        error = dsl_pool_hold(lastsnap, FTAG, &dp);
        if (error != 0)
                return (error);

        error = dsl_dataset_hold(dp, lastsnap, FTAG, &new);
        if (error == 0 && !new->ds_is_snapshot) {
                dsl_dataset_rele(new, FTAG);
                error = SET_ERROR(EINVAL);
        }
        if (error != 0) {
                dsl_pool_rele(dp, FTAG);
                return (error);
        }
        error = dsl_dataset_hold(dp, firstsnap, FTAG, &old);
        if (error == 0 && !old->ds_is_snapshot) {
                dsl_dataset_rele(old, FTAG);
                error = SET_ERROR(EINVAL);
        }
        if (error != 0) {
                dsl_dataset_rele(new, FTAG);
                dsl_pool_rele(dp, FTAG);
                return (error);
        }

        error = dsl_dataset_space_wouldfree(old, new, &used, &comp, &uncomp);
        dsl_dataset_rele(old, FTAG);
        dsl_dataset_rele(new, FTAG);
        dsl_pool_rele(dp, FTAG);
        fnvlist_add_uint64(outnvl, "used", used);
        fnvlist_add_uint64(outnvl, "compressed", comp);
        fnvlist_add_uint64(outnvl, "uncompressed", uncomp);
        return (error);
}

/*
 * innvl: {
 *     "fd" -> file descriptor to write stream to (int32)
 *     (optional) "fromsnap" -> full snap name to send an incremental from
 *     (optional) "largeblockok" -> (value ignored)
 *         indicates that blocks > 128KB are permitted
 *     (optional) "embedok" -> (value ignored)
 *         presence indicates DRR_WRITE_EMBEDDED records are permitted
 *     (optional) "compressok" -> (value ignored)
 *         presence indicates compressed DRR_WRITE records are permitted
 *     (optional) "resume_object" and "resume_offset" -> (uint64)
 *         if present, resume send stream from specified object and offset.
 * }
 *
 * outnvl is unused
 */
/* ARGSUSED */
static int
zfs_ioc_send_new(const char *snapname, nvlist_t *innvl, nvlist_t *outnvl)
{
        int error;
        offset_t off;
        char *fromname = NULL;
        int fd;
        file_t *fp;
        boolean_t largeblockok;
        boolean_t embedok;
        boolean_t compressok;
        uint64_t resumeobj = 0;
        uint64_t resumeoff = 0;

        error = nvlist_lookup_int32(innvl, "fd", &fd);
        if (error != 0)
                return (SET_ERROR(EINVAL));

        (void) nvlist_lookup_string(innvl, "fromsnap", &fromname);

        largeblockok = nvlist_exists(innvl, "largeblockok");
        embedok = nvlist_exists(innvl, "embedok");
        compressok = nvlist_exists(innvl, "compressok");

        (void) nvlist_lookup_uint64(innvl, "resume_object", &resumeobj);
        (void) nvlist_lookup_uint64(innvl, "resume_offset", &resumeoff);

        if ((fp = getf(fd)) == NULL)
                return (SET_ERROR(EBADF));

        off = fp->f_offset;
        error = dmu_send(snapname, fromname, embedok, largeblockok, compressok,
                fd, resumeobj, resumeoff, fp->f_vnode, &off);

        if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
                fp->f_offset = off;

        releasef(fd);
        return (error);
}

/*
 * Determine approximately how large a zfs send stream will be -- the number
 * of bytes that will be written to the fd supplied to zfs_ioc_send_new().
 *
 * innvl: {
 *     (optional) "from" -> full snap or bookmark name to send an incremental
 *                          from
 *     (optional) "largeblockok" -> (value ignored)
 *         indicates that blocks > 128KB are permitted
 *     (optional) "embedok" -> (value ignored)
 *         presence indicates DRR_WRITE_EMBEDDED records are permitted
 *     (optional) "compressok" -> (value ignored)
 *         presence indicates compressed DRR_WRITE records are permitted
 * }
 *
 * outnvl: {
 *     "space" -> bytes of space (uint64)
 * }
 */
static int
zfs_ioc_send_space(const char *snapname, nvlist_t *innvl, nvlist_t *outnvl)
{
        dsl_pool_t *dp;
        dsl_dataset_t *tosnap;
        int error;
        char *fromname;
        /* LINTED E_FUNC_SET_NOT_USED */
        boolean_t largeblockok;
        /* LINTED E_FUNC_SET_NOT_USED */
        boolean_t embedok;
        boolean_t compressok;
        uint64_t space;

        error = dsl_pool_hold(snapname, FTAG, &dp);
        if (error != 0)
                return (error);

        error = dsl_dataset_hold(dp, snapname, FTAG, &tosnap);
        if (error != 0) {
                dsl_pool_rele(dp, FTAG);
                return (error);
        }

        largeblockok = nvlist_exists(innvl, "largeblockok");
        embedok = nvlist_exists(innvl, "embedok");
        compressok = nvlist_exists(innvl, "compressok");

        error = nvlist_lookup_string(innvl, "from", &fromname);
        if (error == 0) {
                if (strchr(fromname, '@') != NULL) {
                        /*
                         * If from is a snapshot, hold it and use the more
                         * efficient dmu_send_estimate to estimate send space
                         * size using deadlists.
                         */
                        dsl_dataset_t *fromsnap;
                        error = dsl_dataset_hold(dp, fromname, FTAG, &fromsnap);
                        if (error != 0)
                                goto out;
                        error = dmu_send_estimate(tosnap, fromsnap, compressok,
                                &space);
                        dsl_dataset_rele(fromsnap, FTAG);
                } else if (strchr(fromname, '#') != NULL) {
                        /*
                         * If from is a bookmark, fetch the creation TXG of the
                         * snapshot it was created from and use that to find
                         * blocks that were born after it.
                         */
                        zfs_bookmark_phys_t frombm;

                        error = dsl_bookmark_lookup(dp, fromname, tosnap,
                            &frombm);
                        if (error != 0)
                                goto out;
                        error = dmu_send_estimate_from_txg(tosnap,
                            frombm.zbm_creation_txg, compressok, &space);
                } else {
                        /*
                         * from is not properly formatted as a snapshot or
                         * bookmark
                         */
                        error = SET_ERROR(EINVAL);
                        goto out;
                }
        } else {
                // If estimating the size of a full send, use dmu_send_estimate
                error = dmu_send_estimate(tosnap, NULL, compressok, &space);
        }

        fnvlist_add_uint64(outnvl, "space", space);

out:
        dsl_dataset_rele(tosnap, FTAG);
        dsl_pool_rele(dp, FTAG);
        return (error);
}

static zfs_ioc_vec_t zfs_ioc_vec[ZFS_IOC_LAST - ZFS_IOC_FIRST];

static void
zfs_ioctl_register_legacy(zfs_ioc_t ioc, zfs_ioc_legacy_func_t *func,
    zfs_secpolicy_func_t *secpolicy, zfs_ioc_namecheck_t namecheck,
    boolean_t log_history, zfs_ioc_poolcheck_t pool_check)
{
        zfs_ioc_vec_t *vec = &zfs_ioc_vec[ioc - ZFS_IOC_FIRST];

        ASSERT3U(ioc, >=, ZFS_IOC_FIRST);
        ASSERT3U(ioc, <, ZFS_IOC_LAST);
        ASSERT3P(vec->zvec_legacy_func, ==, NULL);
        ASSERT3P(vec->zvec_func, ==, NULL);

        vec->zvec_legacy_func = func;
        vec->zvec_secpolicy = secpolicy;
        vec->zvec_namecheck = namecheck;
        vec->zvec_allow_log = log_history;
        vec->zvec_pool_check = pool_check;
}

/*
 * See the block comment at the beginning of this file for details on
 * each argument to this function.
 */
static void
zfs_ioctl_register(const char *name, zfs_ioc_t ioc, zfs_ioc_func_t *func,
    zfs_secpolicy_func_t *secpolicy, zfs_ioc_namecheck_t namecheck,
    zfs_ioc_poolcheck_t pool_check, boolean_t smush_outnvlist,
    boolean_t allow_log)
{
        zfs_ioc_vec_t *vec = &zfs_ioc_vec[ioc - ZFS_IOC_FIRST];

        ASSERT3U(ioc, >=, ZFS_IOC_FIRST);
        ASSERT3U(ioc, <, ZFS_IOC_LAST);
        ASSERT3P(vec->zvec_legacy_func, ==, NULL);
        ASSERT3P(vec->zvec_func, ==, NULL);

        /* if we are logging, the name must be valid */
        ASSERT(!allow_log || namecheck != NO_NAME);

        vec->zvec_name = name;
        vec->zvec_func = func;
        vec->zvec_secpolicy = secpolicy;
        vec->zvec_namecheck = namecheck;
        vec->zvec_pool_check = pool_check;
        vec->zvec_smush_outnvlist = smush_outnvlist;
        vec->zvec_allow_log = allow_log;
}

static void
zfs_ioctl_register_pool(zfs_ioc_t ioc, zfs_ioc_legacy_func_t *func,
    zfs_secpolicy_func_t *secpolicy, boolean_t log_history,
    zfs_ioc_poolcheck_t pool_check)
{
        zfs_ioctl_register_legacy(ioc, func, secpolicy,
            POOL_NAME, log_history, pool_check);
}

static void
zfs_ioctl_register_dataset_nolog(zfs_ioc_t ioc, zfs_ioc_legacy_func_t *func,
    zfs_secpolicy_func_t *secpolicy, zfs_ioc_poolcheck_t pool_check)
{
        zfs_ioctl_register_legacy(ioc, func, secpolicy,
            DATASET_NAME, B_FALSE, pool_check);
}

static void
zfs_ioctl_register_pool_modify(zfs_ioc_t ioc, zfs_ioc_legacy_func_t *func)
{
        zfs_ioctl_register_legacy(ioc, func, zfs_secpolicy_config,
            POOL_NAME, B_TRUE, POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY);
}

static void
zfs_ioctl_register_pool_meta(zfs_ioc_t ioc, zfs_ioc_legacy_func_t *func,
    zfs_secpolicy_func_t *secpolicy)
{
        zfs_ioctl_register_legacy(ioc, func, secpolicy,
            NO_NAME, B_FALSE, POOL_CHECK_NONE);
}

static void
zfs_ioctl_register_dataset_read_secpolicy(zfs_ioc_t ioc,
    zfs_ioc_legacy_func_t *func, zfs_secpolicy_func_t *secpolicy)
{
        zfs_ioctl_register_legacy(ioc, func, secpolicy,
            DATASET_NAME, B_FALSE, POOL_CHECK_SUSPENDED);
}

static void
zfs_ioctl_register_dataset_read(zfs_ioc_t ioc, zfs_ioc_legacy_func_t *func)
{
        zfs_ioctl_register_dataset_read_secpolicy(ioc, func,
            zfs_secpolicy_read);
}

static void
zfs_ioctl_register_dataset_modify(zfs_ioc_t ioc, zfs_ioc_legacy_func_t *func,
        zfs_secpolicy_func_t *secpolicy)
{
        zfs_ioctl_register_legacy(ioc, func, secpolicy,
            DATASET_NAME, B_TRUE, POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY);
}

static void
zfs_ioctl_init(void)
{
        zfs_ioctl_register("snapshot", ZFS_IOC_SNAPSHOT,
            zfs_ioc_snapshot, zfs_secpolicy_snapshot, POOL_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        zfs_ioctl_register("log_history", ZFS_IOC_LOG_HISTORY,
            zfs_ioc_log_history, zfs_secpolicy_log_history, NO_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_FALSE);

        zfs_ioctl_register("space_snaps", ZFS_IOC_SPACE_SNAPS,
            zfs_ioc_space_snaps, zfs_secpolicy_read, DATASET_NAME,
            POOL_CHECK_SUSPENDED, B_FALSE, B_FALSE);

        zfs_ioctl_register("send", ZFS_IOC_SEND_NEW,
            zfs_ioc_send_new, zfs_secpolicy_send_new, DATASET_NAME,
            POOL_CHECK_SUSPENDED, B_FALSE, B_FALSE);

        zfs_ioctl_register("send_space", ZFS_IOC_SEND_SPACE,
            zfs_ioc_send_space, zfs_secpolicy_read, DATASET_NAME,
            POOL_CHECK_SUSPENDED, B_FALSE, B_FALSE);

        zfs_ioctl_register("create", ZFS_IOC_CREATE,
            zfs_ioc_create, zfs_secpolicy_create_clone, DATASET_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        zfs_ioctl_register("clone", ZFS_IOC_CLONE,
            zfs_ioc_clone, zfs_secpolicy_create_clone, DATASET_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        zfs_ioctl_register("destroy_snaps", ZFS_IOC_DESTROY_SNAPS,
            zfs_ioc_destroy_snaps, zfs_secpolicy_destroy_snaps, POOL_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        zfs_ioctl_register("hold", ZFS_IOC_HOLD,
            zfs_ioc_hold, zfs_secpolicy_hold, POOL_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);
        zfs_ioctl_register("release", ZFS_IOC_RELEASE,
            zfs_ioc_release, zfs_secpolicy_release, POOL_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        zfs_ioctl_register("get_holds", ZFS_IOC_GET_HOLDS,
            zfs_ioc_get_holds, zfs_secpolicy_read, DATASET_NAME,
            POOL_CHECK_SUSPENDED, B_FALSE, B_FALSE);

        zfs_ioctl_register("rollback", ZFS_IOC_ROLLBACK,
            zfs_ioc_rollback, zfs_secpolicy_rollback, DATASET_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_TRUE);

        zfs_ioctl_register("bookmark", ZFS_IOC_BOOKMARK,
            zfs_ioc_bookmark, zfs_secpolicy_bookmark, POOL_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        zfs_ioctl_register("get_bookmarks", ZFS_IOC_GET_BOOKMARKS,
            zfs_ioc_get_bookmarks, zfs_secpolicy_read, DATASET_NAME,
            POOL_CHECK_SUSPENDED, B_FALSE, B_FALSE);

        zfs_ioctl_register("destroy_bookmarks", ZFS_IOC_DESTROY_BOOKMARKS,
            zfs_ioc_destroy_bookmarks, zfs_secpolicy_destroy_bookmarks,
            POOL_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        zfs_ioctl_register("receive", ZFS_IOC_RECV_NEW,
            zfs_ioc_recv_new, zfs_secpolicy_recv_new, DATASET_NAME,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE);

        /* IOCTLS that use the legacy function signature */

        zfs_ioctl_register_legacy(ZFS_IOC_POOL_FREEZE, zfs_ioc_pool_freeze,
            zfs_secpolicy_config, NO_NAME, B_FALSE, POOL_CHECK_READONLY);

        zfs_ioctl_register_pool(ZFS_IOC_POOL_CREATE, zfs_ioc_pool_create,
            zfs_secpolicy_config, B_TRUE, POOL_CHECK_NONE);
        zfs_ioctl_register_pool_modify(ZFS_IOC_POOL_SCAN,
            zfs_ioc_pool_scan);
        zfs_ioctl_register_pool_modify(ZFS_IOC_POOL_UPGRADE,
            zfs_ioc_pool_upgrade);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_ADD,
            zfs_ioc_vdev_add);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_REMOVE,
            zfs_ioc_vdev_remove);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_SET_STATE,
            zfs_ioc_vdev_set_state);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_ATTACH,
            zfs_ioc_vdev_attach);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_DETACH,
            zfs_ioc_vdev_detach);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_SETPATH,
            zfs_ioc_vdev_setpath);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_SETFRU,
            zfs_ioc_vdev_setfru);
        zfs_ioctl_register_pool_modify(ZFS_IOC_POOL_SET_PROPS,
            zfs_ioc_pool_set_props);
        zfs_ioctl_register_pool_modify(ZFS_IOC_VDEV_SPLIT,
            zfs_ioc_vdev_split);
        zfs_ioctl_register_pool_modify(ZFS_IOC_POOL_REGUID,
            zfs_ioc_pool_reguid);

        zfs_ioctl_register_pool_meta(ZFS_IOC_POOL_CONFIGS,
            zfs_ioc_pool_configs, zfs_secpolicy_none);
        zfs_ioctl_register_pool_meta(ZFS_IOC_POOL_TRYIMPORT,
            zfs_ioc_pool_tryimport, zfs_secpolicy_config);
        zfs_ioctl_register_pool_meta(ZFS_IOC_INJECT_FAULT,
            zfs_ioc_inject_fault, zfs_secpolicy_inject);
        zfs_ioctl_register_pool_meta(ZFS_IOC_CLEAR_FAULT,
            zfs_ioc_clear_fault, zfs_secpolicy_inject);
        zfs_ioctl_register_pool_meta(ZFS_IOC_INJECT_LIST_NEXT,
            zfs_ioc_inject_list_next, zfs_secpolicy_inject);

        /*
         * pool destroy, and export don't log the history as part of
         * zfsdev_ioctl, but rather zfs_ioc_pool_export
         * does the logging of those commands.
         */
        zfs_ioctl_register_pool(ZFS_IOC_POOL_DESTROY, zfs_ioc_pool_destroy,
            zfs_secpolicy_config, B_FALSE, POOL_CHECK_SUSPENDED);
        zfs_ioctl_register_pool(ZFS_IOC_POOL_EXPORT, zfs_ioc_pool_export,
            zfs_secpolicy_config, B_FALSE, POOL_CHECK_SUSPENDED);

        zfs_ioctl_register_pool(ZFS_IOC_POOL_STATS, zfs_ioc_pool_stats,
            zfs_secpolicy_read, B_FALSE, POOL_CHECK_NONE);
        zfs_ioctl_register_pool(ZFS_IOC_POOL_GET_PROPS, zfs_ioc_pool_get_props,
            zfs_secpolicy_read, B_FALSE, POOL_CHECK_NONE);

        zfs_ioctl_register_pool(ZFS_IOC_ERROR_LOG, zfs_ioc_error_log,
            zfs_secpolicy_inject, B_FALSE, POOL_CHECK_SUSPENDED);
        zfs_ioctl_register_pool(ZFS_IOC_DSOBJ_TO_DSNAME,
            zfs_ioc_dsobj_to_dsname,
            zfs_secpolicy_diff, B_FALSE, POOL_CHECK_SUSPENDED);
        zfs_ioctl_register_pool(ZFS_IOC_POOL_GET_HISTORY,
            zfs_ioc_pool_get_history,
            zfs_secpolicy_config, B_FALSE, POOL_CHECK_SUSPENDED);

        zfs_ioctl_register_pool(ZFS_IOC_POOL_IMPORT, zfs_ioc_pool_import,
            zfs_secpolicy_config, B_TRUE, POOL_CHECK_NONE);

        zfs_ioctl_register_pool(ZFS_IOC_CLEAR, zfs_ioc_clear,
            zfs_secpolicy_config, B_TRUE, POOL_CHECK_NONE);
        zfs_ioctl_register_pool(ZFS_IOC_POOL_REOPEN, zfs_ioc_pool_reopen,
            zfs_secpolicy_config, B_TRUE, POOL_CHECK_SUSPENDED);

        zfs_ioctl_register_dataset_read(ZFS_IOC_SPACE_WRITTEN,
            zfs_ioc_space_written);
        zfs_ioctl_register_dataset_read(ZFS_IOC_OBJSET_RECVD_PROPS,
            zfs_ioc_objset_recvd_props);
        zfs_ioctl_register_dataset_read(ZFS_IOC_NEXT_OBJ,
            zfs_ioc_next_obj);
        zfs_ioctl_register_dataset_read(ZFS_IOC_GET_FSACL,
            zfs_ioc_get_fsacl);
        zfs_ioctl_register_dataset_read(ZFS_IOC_OBJSET_STATS,
            zfs_ioc_objset_stats);
        zfs_ioctl_register_dataset_read(ZFS_IOC_OBJSET_ZPLPROPS,
            zfs_ioc_objset_zplprops);
        zfs_ioctl_register_dataset_read(ZFS_IOC_DATASET_LIST_NEXT,
            zfs_ioc_dataset_list_next);
        zfs_ioctl_register_dataset_read(ZFS_IOC_SNAPSHOT_LIST_NEXT,
            zfs_ioc_snapshot_list_next);
        zfs_ioctl_register_dataset_read(ZFS_IOC_SEND_PROGRESS,
            zfs_ioc_send_progress);

        zfs_ioctl_register_dataset_read_secpolicy(ZFS_IOC_DIFF,
            zfs_ioc_diff, zfs_secpolicy_diff);
        zfs_ioctl_register_dataset_read_secpolicy(ZFS_IOC_OBJ_TO_STATS,
            zfs_ioc_obj_to_stats, zfs_secpolicy_diff);
        zfs_ioctl_register_dataset_read_secpolicy(ZFS_IOC_OBJ_TO_PATH,
            zfs_ioc_obj_to_path, zfs_secpolicy_diff);
        zfs_ioctl_register_dataset_read_secpolicy(ZFS_IOC_USERSPACE_ONE,
            zfs_ioc_userspace_one, zfs_secpolicy_userspace_one);
        zfs_ioctl_register_dataset_read_secpolicy(ZFS_IOC_USERSPACE_MANY,
            zfs_ioc_userspace_many, zfs_secpolicy_userspace_many);
        zfs_ioctl_register_dataset_read_secpolicy(ZFS_IOC_SEND,
            zfs_ioc_send, zfs_secpolicy_send);

        zfs_ioctl_register_dataset_modify(ZFS_IOC_SET_PROP, zfs_ioc_set_prop,
            zfs_secpolicy_none);
        zfs_ioctl_register_dataset_modify(ZFS_IOC_DESTROY, zfs_ioc_destroy,
            zfs_secpolicy_destroy);
        zfs_ioctl_register_dataset_modify(ZFS_IOC_RENAME, zfs_ioc_rename,
            zfs_secpolicy_rename);
        zfs_ioctl_register_dataset_modify(ZFS_IOC_RECV, zfs_ioc_recv,
            zfs_secpolicy_recv);
        zfs_ioctl_register_dataset_modify(ZFS_IOC_PROMOTE, zfs_ioc_promote,
            zfs_secpolicy_promote);
        zfs_ioctl_register_dataset_modify(ZFS_IOC_INHERIT_PROP,
            zfs_ioc_inherit_prop, zfs_secpolicy_inherit_prop);
        zfs_ioctl_register_dataset_modify(ZFS_IOC_SET_FSACL, zfs_ioc_set_fsacl,
            zfs_secpolicy_set_fsacl);

        zfs_ioctl_register_dataset_nolog(ZFS_IOC_SHARE, zfs_ioc_share,
            zfs_secpolicy_share, POOL_CHECK_NONE);
        zfs_ioctl_register_dataset_nolog(ZFS_IOC_SMB_ACL, zfs_ioc_smb_acl,
            zfs_secpolicy_smb_acl, POOL_CHECK_NONE);
        zfs_ioctl_register_dataset_nolog(ZFS_IOC_USERSPACE_UPGRADE,
            zfs_ioc_userspace_upgrade, zfs_secpolicy_userspace_upgrade,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY);
        zfs_ioctl_register_dataset_nolog(ZFS_IOC_TMP_SNAPSHOT,
            zfs_ioc_tmp_snapshot, zfs_secpolicy_tmp_snapshot,
            POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY);

        /*
         * ZoL functions
         */
        zfs_ioctl_register_legacy(ZFS_IOC_EVENTS_NEXT, zfs_ioc_events_next,
            zfs_secpolicy_config, NO_NAME, B_FALSE, POOL_CHECK_NONE);
        zfs_ioctl_register_legacy(ZFS_IOC_EVENTS_CLEAR, zfs_ioc_events_clear,
            zfs_secpolicy_config, NO_NAME, B_FALSE, POOL_CHECK_NONE);
        zfs_ioctl_register_legacy(ZFS_IOC_EVENTS_SEEK, zfs_ioc_events_seek,
            zfs_secpolicy_config, NO_NAME, B_FALSE, POOL_CHECK_NONE);
}

int
pool_status_check(const char *name, zfs_ioc_namecheck_t type,
    zfs_ioc_poolcheck_t check)
{
        spa_t *spa;
        int error;

        ASSERT(type == POOL_NAME || type == DATASET_NAME);

        if (check & POOL_CHECK_NONE)
                return (0);

        error = spa_open(name, &spa, FTAG);
        if (error == 0) {
                if ((check & POOL_CHECK_SUSPENDED) && spa_suspended(spa))
                        error = SET_ERROR(EAGAIN);
                else if ((check & POOL_CHECK_READONLY) && !spa_writeable(spa))
                        error = SET_ERROR(EROFS);
                spa_close(spa, FTAG);
        }
        return (error);
}

static void *
zfsdev_get_state_impl(minor_t minor, enum zfsdev_state_type which)
{
        zfsdev_state_t *zs;

        for (zs = zfsdev_state_list; zs != NULL; zs = zs->zs_next) {
                if (zs->zs_minor == minor) {
                        smp_rmb();
                        switch (which) {
                        case ZST_ONEXIT:
                                return (zs->zs_onexit);
                        case ZST_ZEVENT:
                                return (zs->zs_zevent);
                        case ZST_ALL:
                                return (zs);
                        }
                }
        }

        return (NULL);
}

void *
zfsdev_get_state(minor_t minor, enum zfsdev_state_type which)
{
        void *ptr;

        ptr = zfsdev_get_state_impl(minor, which);

        return (ptr);
}

int
zfsdev_getminor(struct file *filp, minor_t *minorp)
{
        zfsdev_state_t *zs, *fpd;

        ASSERT(filp != NULL);
        ASSERT(!MUTEX_HELD(&zfsdev_state_lock));

        fpd = filp->private_data;
        if (fpd == NULL)
                return (EBADF);

        mutex_enter(&zfsdev_state_lock);

        for (zs = zfsdev_state_list; zs != NULL; zs = zs->zs_next) {

                if (zs->zs_minor == -1)
                        continue;

                if (fpd == zs) {
                        *minorp = fpd->zs_minor;
                        mutex_exit(&zfsdev_state_lock);
                        return (0);
                }
        }

        mutex_exit(&zfsdev_state_lock);

        return (EBADF);
}

/*
 * Find a free minor number.  The zfsdev_state_list is expected to
 * be short since it is only a list of currently open file handles.
 */
minor_t
zfsdev_minor_alloc(void)
{
        static minor_t last_minor = 0;
        minor_t m;

        ASSERT(MUTEX_HELD(&zfsdev_state_lock));

        for (m = last_minor + 1; m != last_minor; m++) {
                if (m > ZFSDEV_MAX_MINOR)
                        m = 1;
                if (zfsdev_get_state_impl(m, ZST_ALL) == NULL) {
                        last_minor = m;
                        return (m);
                }
        }

        return (0);
}

static int
zfsdev_state_init(struct file *filp)
{
        zfsdev_state_t *zs, *zsprev = NULL;
        minor_t minor;
        boolean_t newzs = B_FALSE;

        ASSERT(MUTEX_HELD(&zfsdev_state_lock));

        minor = zfsdev_minor_alloc();
        if (minor == 0)
                return (SET_ERROR(ENXIO));

        for (zs = zfsdev_state_list; zs != NULL; zs = zs->zs_next) {
                if (zs->zs_minor == -1)
                        break;
                zsprev = zs;
        }

        if (!zs) {
                zs = kmem_zalloc(sizeof (zfsdev_state_t), KM_SLEEP);
                newzs = B_TRUE;
        }

        zs->zs_file = filp;
        filp->private_data = zs;

        zfs_onexit_init((zfs_onexit_t **)&zs->zs_onexit);
        zfs_zevent_init((zfs_zevent_t **)&zs->zs_zevent);


        /*
         * In order to provide for lock-free concurrent read access
         * to the minor list in zfsdev_get_state_impl(), new entries
         * must be completely written before linking them into the
         * list whereas existing entries are already linked; the last
         * operation must be updating zs_minor (from -1 to the new
         * value).
         */
        if (newzs) {
                zs->zs_minor = minor;
                smp_wmb();
                zsprev->zs_next = zs;
        } else {
                smp_wmb();
                zs->zs_minor = minor;
        }

        return (0);
}

static int
zfsdev_state_destroy(struct file *filp)
{
        zfsdev_state_t *zs;

        ASSERT(MUTEX_HELD(&zfsdev_state_lock));
        ASSERT(filp->private_data != NULL);

        zs = filp->private_data;
        zs->zs_minor = -1;
        zfs_onexit_destroy(zs->zs_onexit);
        zfs_zevent_destroy(zs->zs_zevent);

        return (0);
}

static int
zfsdev_open(struct inode *ino, struct file *filp)
{
        int error;

        mutex_enter(&zfsdev_state_lock);
        error = zfsdev_state_init(filp);
        mutex_exit(&zfsdev_state_lock);

        return (-error);
}

static int
zfsdev_release(struct inode *ino, struct file *filp)
{
        int error;

        mutex_enter(&zfsdev_state_lock);
        error = zfsdev_state_destroy(filp);
        mutex_exit(&zfsdev_state_lock);

        return (-error);
}

static long
zfsdev_ioctl(struct file *filp, unsigned cmd, unsigned long arg)
{
        zfs_cmd_t *zc;
        uint_t vecnum;
        int error, rc, flag = 0;
        const zfs_ioc_vec_t *vec;
        char *saved_poolname = NULL;
        nvlist_t *innvl = NULL;
        fstrans_cookie_t cookie;

        vecnum = cmd - ZFS_IOC_FIRST;
        if (vecnum >= sizeof (zfs_ioc_vec) / sizeof (zfs_ioc_vec[0]))
                return (-SET_ERROR(EINVAL));
        vec = &zfs_ioc_vec[vecnum];

        /*
         * The registered ioctl list may be sparse, verify that either
         * a normal or legacy handler are registered.
         */
        if (vec->zvec_func == NULL && vec->zvec_legacy_func == NULL)
                return (-SET_ERROR(EINVAL));

        zc = kmem_zalloc(sizeof (zfs_cmd_t), KM_SLEEP);

        error = ddi_copyin((void *)arg, zc, sizeof (zfs_cmd_t), flag);
        if (error != 0) {
                error = SET_ERROR(EFAULT);
                goto out;
        }

        zc->zc_iflags = flag & FKIOCTL;
        if (zc->zc_nvlist_src_size > MAX_NVLIST_SRC_SIZE) {
                /*
                 * Make sure the user doesn't pass in an insane value for
                 * zc_nvlist_src_size.  We have to check, since we will end
                 * up allocating that much memory inside of get_nvlist().  This
                 * prevents a nefarious user from allocating tons of kernel
                 * memory.
                 *
                 * Also, we return EINVAL instead of ENOMEM here.  The reason
                 * being that returning ENOMEM from an ioctl() has a special
                 * connotation; that the user's size value is too small and
                 * needs to be expanded to hold the nvlist.  See
                 * zcmd_expand_dst_nvlist() for details.
                 */
                error = SET_ERROR(EINVAL);      /* User's size too big */

        } else if (zc->zc_nvlist_src_size != 0) {
                error = get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
                    zc->zc_iflags, &innvl);
                if (error != 0)
                        goto out;
        }

        /*
         * Ensure that all pool/dataset names are valid before we pass down to
         * the lower layers.
         */
        zc->zc_name[sizeof (zc->zc_name) - 1] = '\0';
        switch (vec->zvec_namecheck) {
        case POOL_NAME:
                if (pool_namecheck(zc->zc_name, NULL, NULL) != 0)
                        error = SET_ERROR(EINVAL);
                else
                        error = pool_status_check(zc->zc_name,
                            vec->zvec_namecheck, vec->zvec_pool_check);
                break;

        case DATASET_NAME:
                if (dataset_namecheck(zc->zc_name, NULL, NULL) != 0)
                        error = SET_ERROR(EINVAL);
                else
                        error = pool_status_check(zc->zc_name,
                            vec->zvec_namecheck, vec->zvec_pool_check);
                break;

        case NO_NAME:
                break;
        }


        if (error == 0 && !(flag & FKIOCTL)) {
                cookie = spl_fstrans_mark();
                error = vec->zvec_secpolicy(zc, innvl, CRED());
                spl_fstrans_unmark(cookie);
        }

        if (error != 0)
                goto out;

        /* legacy ioctls can modify zc_name */
        saved_poolname = strdup(zc->zc_name);
        if (saved_poolname == NULL) {
                error = SET_ERROR(ENOMEM);
                goto out;
        } else {
                saved_poolname[strcspn(saved_poolname, "/@#")] = '\0';
        }

        if (vec->zvec_func != NULL) {
                nvlist_t *outnvl;
                int puterror = 0;
                spa_t *spa;
                nvlist_t *lognv = NULL;

                ASSERT(vec->zvec_legacy_func == NULL);

                /*
                 * Add the innvl to the lognv before calling the func,
                 * in case the func changes the innvl.
                 */
                if (vec->zvec_allow_log) {
                        lognv = fnvlist_alloc();
                        fnvlist_add_string(lognv, ZPOOL_HIST_IOCTL,
                            vec->zvec_name);
                        if (!nvlist_empty(innvl)) {
                                fnvlist_add_nvlist(lognv, ZPOOL_HIST_INPUT_NVL,
                                    innvl);
                        }
                }

                outnvl = fnvlist_alloc();
                cookie = spl_fstrans_mark();
                error = vec->zvec_func(zc->zc_name, innvl, outnvl);
                spl_fstrans_unmark(cookie);

                if (error == 0 && vec->zvec_allow_log &&
                    spa_open(zc->zc_name, &spa, FTAG) == 0) {
                        if (!nvlist_empty(outnvl)) {
                                fnvlist_add_nvlist(lognv, ZPOOL_HIST_OUTPUT_NVL,
                                    outnvl);
                        }
                        (void) spa_history_log_nvl(spa, lognv);
                        spa_close(spa, FTAG);
                }
                fnvlist_free(lognv);

                if (!nvlist_empty(outnvl) || zc->zc_nvlist_dst_size != 0) {
                        int smusherror = 0;
                        if (vec->zvec_smush_outnvlist) {
                                smusherror = nvlist_smush(outnvl,
                                    zc->zc_nvlist_dst_size);
                        }
                        if (smusherror == 0)
                                puterror = put_nvlist(zc, outnvl);
                }

                if (puterror != 0)
                        error = puterror;

                nvlist_free(outnvl);
        } else {
                cookie = spl_fstrans_mark();
                error = vec->zvec_legacy_func(zc);
                spl_fstrans_unmark(cookie);
        }

out:
        nvlist_free(innvl);
        rc = ddi_copyout(zc, (void *)arg, sizeof (zfs_cmd_t), flag);
        if (error == 0 && rc != 0)
                error = SET_ERROR(EFAULT);
        if (error == 0 && vec->zvec_allow_log) {
                char *s = tsd_get(zfs_allow_log_key);
                if (s != NULL)
                        strfree(s);
                (void) tsd_set(zfs_allow_log_key, saved_poolname);
        } else {
                if (saved_poolname != NULL)
                        strfree(saved_poolname);
        }

        kmem_free(zc, sizeof (zfs_cmd_t));
        return (-error);
}

#ifdef CONFIG_COMPAT
static long
zfsdev_compat_ioctl(struct file *filp, unsigned cmd, unsigned long arg)
{
        return (zfsdev_ioctl(filp, cmd, arg));
}
#else
#define zfsdev_compat_ioctl     NULL
#endif

static const struct file_operations zfsdev_fops = {
        .open           = zfsdev_open,
        .release        = zfsdev_release,
        .unlocked_ioctl = zfsdev_ioctl,
        .compat_ioctl   = zfsdev_compat_ioctl,
        .owner          = THIS_MODULE,
};

static struct miscdevice zfs_misc = {
        .minor          = MISC_DYNAMIC_MINOR,
        .name           = ZFS_DRIVER,
        .fops           = &zfsdev_fops,
};

static int
zfs_attach(void)
{
        int error;

        mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
        zfsdev_state_list = kmem_zalloc(sizeof (zfsdev_state_t), KM_SLEEP);
        zfsdev_state_list->zs_minor = -1;

        error = misc_register(&zfs_misc);
        if (error != 0) {
                printk(KERN_INFO "ZFS: misc_register() failed %d\n", error);
                return (error);
        }

        return (0);
}

static void
zfs_detach(void)
{
        zfsdev_state_t *zs, *zsprev = NULL;

        misc_deregister(&zfs_misc);
        mutex_destroy(&zfsdev_state_lock);

        for (zs = zfsdev_state_list; zs != NULL; zs = zs->zs_next) {
                if (zsprev)
                        kmem_free(zsprev, sizeof (zfsdev_state_t));
                zsprev = zs;
        }
        if (zsprev)
                kmem_free(zsprev, sizeof (zfsdev_state_t));
}

static void
zfs_allow_log_destroy(void *arg)
{
        char *poolname = arg;

        if (poolname != NULL)
                strfree(poolname);
}

#ifdef DEBUG
#define ZFS_DEBUG_STR   " (DEBUG mode)"
#else
#define ZFS_DEBUG_STR   ""
#endif

static int __init
_init(void)
{
        int error;

        error = -vn_set_pwd("/");
        if (error) {
                printk(KERN_NOTICE
                    "ZFS: Warning unable to set pwd to '/': %d\n", error);
                return (error);
        }

        if ((error = -zvol_init()) != 0)
                return (error);

        spa_init(FREAD | FWRITE);
        zfs_init();

        zfs_ioctl_init();

        if ((error = zfs_attach()) != 0)
                goto out;

        tsd_create(&zfs_fsyncer_key, NULL);
        tsd_create(&rrw_tsd_key, rrw_tsd_destroy);
        tsd_create(&zfs_allow_log_key, zfs_allow_log_destroy);

        printk(KERN_NOTICE "ZFS: Loaded module v%s-%s%s, "
            "ZFS pool version %s, ZFS filesystem version %s\n",
            ZFS_META_VERSION, ZFS_META_RELEASE, ZFS_DEBUG_STR,
            SPA_VERSION_STRING, ZPL_VERSION_STRING);
#ifndef CONFIG_FS_POSIX_ACL
        printk(KERN_NOTICE "ZFS: Posix ACLs disabled by kernel\n");
#endif /* CONFIG_FS_POSIX_ACL */

        return (0);

out:
        zfs_fini();
        spa_fini();
        (void) zvol_fini();
        printk(KERN_NOTICE "ZFS: Failed to Load ZFS Filesystem v%s-%s%s"
            ", rc = %d\n", ZFS_META_VERSION, ZFS_META_RELEASE,
            ZFS_DEBUG_STR, error);

        return (error);
}

static void __exit
_fini(void)
{
        zfs_detach();
        zfs_fini();
        spa_fini();
        zvol_fini();

        tsd_destroy(&zfs_fsyncer_key);
        tsd_destroy(&rrw_tsd_key);
        tsd_destroy(&zfs_allow_log_key);

        printk(KERN_NOTICE "ZFS: Unloaded module v%s-%s%s\n",
            ZFS_META_VERSION, ZFS_META_RELEASE, ZFS_DEBUG_STR);
}

#ifdef HAVE_SPL
module_init(_init);
module_exit(_fini);

MODULE_DESCRIPTION("ZFS");
MODULE_AUTHOR(ZFS_META_AUTHOR);
MODULE_LICENSE(ZFS_META_LICENSE);
MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);
#endif /* HAVE_SPL */