FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/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 https://opensource.org/licenses/CDDL-1.0.
     * 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) 2014, 2016 Joyent, Inc. All rights reserved.
     * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
     * Copyright (c) 2014, Joyent, Inc. All rights reserved.
     * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
     * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
     * Copyright (c) 2013 Steven Hartland. All rights reserved.
     * Copyright (c) 2014 Integros [integros.com]
     * Copyright 2016 Toomas Soome <tsoome@me.com>
     * Copyright (c) 2016 Actifio, Inc. All rights reserved.
     * Copyright (c) 2018, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
     * Copyright 2017 RackTop Systems.
     * Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
     * Copyright (c) 2019 Datto Inc.
     * Copyright (c) 2019, 2020 by Christian Schwarz. All rights reserved.
     * Copyright (c) 2019, 2021, Klara Inc.
     * Copyright (c) 2019, Allan Jude
     */
    
    /*
     * 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).
     *   We want newer versions of libzfs and libzfs_core to run against
     *   existing zfs kernel modules (i.e. a deferred reboot after an update).
     *   Therefore the ioctl numbers cannot change from release to release.
     *
     * 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).
     *
     * zfs_ioc_key_t *nvl_keys
     *  The list of expected/allowable innvl input keys. This list is used
     *  to validate the nvlist input to the ioctl.
    *
    * 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.
    *
    * IOCTL Interface Errors
    *
    * The following ioctl input errors can be returned:
    *   ZFS_ERR_IOC_CMD_UNAVAIL    the ioctl number is not supported by kernel
    *   ZFS_ERR_IOC_ARG_UNAVAIL    an input argument is not supported by kernel
    *   ZFS_ERR_IOC_ARG_REQUIRED   a required input argument is missing
    *   ZFS_ERR_IOC_ARG_BADTYPE    an input argument has an invalid type
    */
   
   #include <sys/types.h>
   #include <sys/param.h>
   #include <sys/errno.h>
   #include <sys/uio_impl.h>
   #include <sys/file.h>
   #include <sys/kmem.h>
   #include <sys/cmn_err.h>
   #include <sys/stat.h>
   #include <sys/zfs_ioctl.h>
   #include <sys/zfs_quota.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/vdev_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_redact.h>
   #include <sys/dmu_tx.h>
   #include <sys/sunddi.h>
   #include <sys/policy.h>
   #include <sys/zone.h>
   #include <sys/nvpair.h>
   #include <sys/pathname.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 <sys/fm/util.h>
   #include <sys/dsl_crypt.h>
   #include <sys/rrwlock.h>
   #include <sys/zfs_file.h>
   
   #include <sys/dmu_recv.h>
   #include <sys/dmu_send.h>
   #include <sys/dmu_recv.h>
   #include <sys/dsl_destroy.h>
   #include <sys/dsl_bookmark.h>
   #include <sys/dsl_userhold.h>
   #include <sys/zfeature.h>
   #include <sys/zcp.h>
   #include <sys/zio_checksum.h>
   #include <sys/vdev_removal.h>
   #include <sys/vdev_impl.h>
   #include <sys/vdev_initialize.h>
   #include <sys/vdev_trim.h>
   
   #include "zfs_namecheck.h"
   #include "zfs_prop.h"
   #include "zfs_deleg.h"
   #include "zfs_comutil.h"
   
   #include <sys/lua/lua.h>
   #include <sys/lua/lauxlib.h>
   #include <sys/zfs_ioctl_impl.h>
   
   kmutex_t zfsdev_state_lock;
   static zfsdev_state_t *zfsdev_state_list;
   
   /*
    * 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.
    * Defaults to 0=auto which is handled by platform code.
    */
   uint64_t zfs_max_nvlist_src_size = 0;
   
   /*
    * When logging the output nvlist of an ioctl in the on-disk history, limit
    * the logged size to this many bytes.  This must be less than DMU_MAX_ACCESS.
    * This applies primarily to zfs_ioc_channel_program().
    */
   static uint64_t zfs_history_output_max = 1024 * 1024;
   
   uint_t zfs_fsyncer_key;
   uint_t zfs_allow_log_key;
   
   /* DATA_TYPE_ANY is used when zkey_type can vary. */
   #define DATA_TYPE_ANY   DATA_TYPE_UNKNOWN
   
   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;
           const zfs_ioc_key_t     *zvec_nvl_keys;
           size_t                  zvec_nvl_key_count;
   } 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,
           ZFS_DELEG_PERM_USEROBJUSED,
           ZFS_DELEG_PERM_USEROBJQUOTA,
           ZFS_DELEG_PERM_GROUPOBJUSED,
           ZFS_DELEG_PERM_GROUPOBJQUOTA,
           ZFS_DELEG_PERM_PROJECTUSED,
           ZFS_DELEG_PERM_PROJECTQUOTA,
           ZFS_DELEG_PERM_PROJECTOBJUSED,
           ZFS_DELEG_PERM_PROJECTOBJQUOTA,
   };
   
   static int zfs_ioc_userspace_upgrade(zfs_cmd_t *zc);
   static int zfs_ioc_id_quota_upgrade(zfs_cmd_t *zc);
   static int zfs_check_settable(const char *name, nvpair_t *property,
       cred_t *cr);
   static int zfs_check_clearable(const 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);
   }
   
   /*
    * 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.
    */
   static int
   zfs_secpolicy_none(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) zc, (void) innvl, (void) cr;
           return (0);
   }
   
   /*
    * Policy for dataset read operations (list children, get statistics).  Requires
    * no privileges, but must be visible in the local zone.
    */
   static int
   zfs_secpolicy_read(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl, (void) 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, zfs_prop_to_name(ZFS_PROP_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, zfs_prop_to_name(ZFS_PROP_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;
   
           /*
            * First do a quick check for root in the global zone, which
            * is allowed to do all write_perms.  This ensures that zfs_ioc_*
            * will get to handle nonexistent datasets.
            */
           if (INGLOBALZONE(curproc) && secpolicy_zfs(cr) == 0)
                   return (0);
   
           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, const 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 zfsvfs_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 const 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, B_TRUE,
                       setsl_tag, &os);
                   if (error != 0)
                           return (SET_ERROR(EPERM));
   
                   dmu_objset_disown(os, B_TRUE, 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 (SET_ERROR(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,
                               zfs_prop_to_name(ZFS_PROP_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));
   }
   
   static int
   zfs_secpolicy_set_fsacl(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           /*
            * permission to set permissions will be evaluated later in
            * dsl_deleg_can_allow()
            */
           (void) innvl;
           return (zfs_dozonecheck(zc->zc_name, cr));
   }
   
   static int
   zfs_secpolicy_rollback(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl;
           return (zfs_secpolicy_write_perms(zc->zc_name,
               ZFS_DELEG_PERM_ROLLBACK, cr));
   }
   
   static int
   zfs_secpolicy_send(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl;
           dsl_pool_t *dp;
           dsl_dataset_t *ds;
           const 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);
   }
   
   static int
   zfs_secpolicy_send_new(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl;
           return (zfs_secpolicy_write_perms(zc->zc_name,
               ZFS_DELEG_PERM_SEND, cr));
   }
   
   static int
   zfs_secpolicy_share(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) zc, (void) innvl, (void) cr;
           return (SET_ERROR(ENOTSUP));
   }
   
   static int
   zfs_secpolicy_smb_acl(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) zc, (void) innvl, (void) cr;
           return (SET_ERROR(ENOTSUP));
   }
   
   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) strlcpy(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));
   }
   
   static int
   zfs_secpolicy_destroy(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl;
           return (zfs_secpolicy_destroy_perms(zc->zc_name, cr));
   }
   
   /*
    * Destroying snapshots with delegated permissions requires
    * descendant mount and destroy permissions.
    */
   static int
   zfs_secpolicy_destroy_snaps(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) zc;
           nvlist_t *snaps;
           nvpair_t *pair, *nextpair;
           int error = 0;
   
           snaps = fnvlist_lookup_nvlist(innvl, "snaps");
   
           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);
   }
   
   static int
   zfs_secpolicy_rename(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl;
           return (zfs_secpolicy_rename_perms(zc->zc_name, zc->zc_value, cr));
   }
   
   static int
   zfs_secpolicy_promote(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl;
           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);
   }
   
   static int
   zfs_secpolicy_recv(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) innvl;
           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));
   }
   
   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.
    */
   static int
   zfs_secpolicy_snapshot(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) zc;
           nvlist_t *snaps;
           int error = 0;
           nvpair_t *pair;
   
           snaps = fnvlist_lookup_nvlist(innvl, "snaps");
   
           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 bookmark in the nvlist.
    */
   static int
   zfs_secpolicy_bookmark(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) zc;
           int error = 0;
   
           for (nvpair_t *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);
   }
   
   static int
   zfs_secpolicy_destroy_bookmarks(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
   {
           (void) zc;
           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);
  }
  
  static int
  zfs_secpolicy_log_history(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) zc, (void) innvl, (void) 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.
   */
  int
  zfs_secpolicy_config(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) zc, (void) innvl;
  
          if (secpolicy_sys_config(cr, B_FALSE) != 0)
                  return (SET_ERROR(EPERM));
  
          return (0);
  }
  
  /*
   * Policy for object to name lookups.
   */
  static int
  zfs_secpolicy_diff(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) innvl;
          int error;
  
          if (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.
   */
  static int
  zfs_secpolicy_inject(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) zc, (void) innvl;
          return (secpolicy_zinject(cr));
  }
  
  static int
  zfs_secpolicy_inherit_prop(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) innvl;
          zfs_prop_t prop = zfs_name_to_prop(zc->zc_value);
  
          if (prop == ZPROP_USERPROP) {
                  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 ||
                      zc->zc_objset_type == ZFS_PROP_USEROBJUSED ||
                      zc->zc_objset_type == ZFS_PROP_USEROBJQUOTA) {
                          if (zc->zc_guid == crgetuid(cr))
                                  return (0);
                  } else if (zc->zc_objset_type == ZFS_PROP_GROUPUSED ||
                      zc->zc_objset_type == ZFS_PROP_GROUPQUOTA ||
                      zc->zc_objset_type == ZFS_PROP_GROUPOBJUSED ||
                      zc->zc_objset_type == ZFS_PROP_GROUPOBJQUOTA) {
                          if (groupmember(zc->zc_guid, cr))
                                  return (0);
                  }
                  /* else is for project quota/used */
          }
  
          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));
  }
  
  static int
  zfs_secpolicy_userspace_upgrade(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) innvl;
          return (zfs_secpolicy_setprop(zc->zc_name, ZFS_PROP_VERSION,
              NULL, cr));
  }
  
  static int
  zfs_secpolicy_hold(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) zc;
          nvpair_t *pair;
          nvlist_t *holds;
          int error;
  
          holds = fnvlist_lookup_nvlist(innvl, "holds");
  
          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);
  }
  
  static int
  zfs_secpolicy_release(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          (void) zc;
          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 (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 (innvl != NULL) {
                  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);
  }
  
  static int
  zfs_secpolicy_load_key(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          return (zfs_secpolicy_write_perms(zc->zc_name,
              ZFS_DELEG_PERM_LOAD_KEY, cr));
  }
  
  static int
  zfs_secpolicy_change_key(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
  {
          return (zfs_secpolicy_write_perms(zc->zc_name,
              ZFS_DELEG_PERM_CHANGE_KEY, cr));
  }
  
  /*
   * 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 (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);
  }
  
  int
  getzfsvfs_impl(objset_t *os, zfsvfs_t **zfvp)
  {
          int error = 0;
          if (dmu_objset_type(os) != DMU_OST_ZFS) {
                  return (SET_ERROR(EINVAL));
          }
  
          mutex_enter(&os->os_user_ptr_lock);
          *zfvp = dmu_objset_get_user(os);
          /* bump s_active only when non-zero to prevent umount race */
          error = zfs_vfs_ref(zfvp);
          mutex_exit(&os->os_user_ptr_lock);
          return (error);
  }
  
  int
  getzfsvfs(const char *dsname, zfsvfs_t **zfvp)
  {
          objset_t *os;
          int error;
  
          error = dmu_objset_hold(dsname, FTAG, &os);
          if (error != 0)
                  return (error);
  
          error = getzfsvfs_impl(os, zfvp);
          dmu_objset_rele(os, FTAG);
          return (error);
  }
  
  /*
   * Find a zfsvfs_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
  zfsvfs_hold(const char *name, const void *tag, zfsvfs_t **zfvp,
      boolean_t writer)
  {
          int error = 0;
  
          if (getzfsvfs(name, zfvp) != 0)
                  error = zfsvfs_create(name, B_FALSE, zfvp);
          if (error == 0) {
                  if (writer)
                          ZFS_TEARDOWN_ENTER_WRITE(*zfvp, tag);
                  else
                          ZFS_TEARDOWN_ENTER_READ(*zfvp, tag);
                  if ((*zfvp)->z_unmounted) {
                          /*
                           * XXX we could probably try again, since the unmounting
                           * thread should be just about to disassociate the
                           * objset from the zfsvfs.
                           */
                          ZFS_TEARDOWN_EXIT(*zfvp, tag);
                          return (SET_ERROR(EBUSY));
                  }
          }
          return (error);
  }
  
  static void
  zfsvfs_rele(zfsvfs_t *zfsvfs, const void *tag)
  {
          ZFS_TEARDOWN_EXIT(zfsvfs, tag);
  
          if (zfs_vfs_held(zfsvfs)) {
                  zfs_vfs_rele(zfsvfs);
          } else {
                  dmu_objset_disown(zfsvfs->z_os, B_TRUE, zfsvfs);
                  zfsvfs_free(zfsvfs);
          }
  }
  
  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;
          dsl_crypto_params_t *dcp = NULL;
          const char *spa_name = zc->zc_name;
          boolean_t unload_wkey = B_TRUE;
  
          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;
                  nvlist_t *hidden_args = NULL;
                  uint64_t version = SPA_VERSION;
                  char *tname;
  
                  (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)
                                  goto pool_props_bad;
                          (void) nvlist_remove_all(props, ZPOOL_ROOTFS_PROPS);
                  }
  
                  (void) nvlist_lookup_nvlist(props, ZPOOL_HIDDEN_ARGS,
                      &hidden_args);
                  error = dsl_crypto_params_create_nvlist(DCP_CMD_NONE,
                      rootprops, hidden_args, &dcp);
                  if (error != 0)
                          goto pool_props_bad;
                  (void) nvlist_remove_all(props, ZPOOL_HIDDEN_ARGS);
  
                  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;
  
                  if (nvlist_lookup_string(props,
                      zpool_prop_to_name(ZPOOL_PROP_TNAME), &tname) == 0)
                          spa_name = tname;
          }
  
          error = spa_create(zc->zc_name, config, props, zplprops, dcp);
  
          /*
           * Set the remaining root properties
           */
          if (!error && (error = zfs_set_prop_nvlist(spa_name,
              ZPROP_SRC_LOCAL, rootprops, NULL)) != 0) {
                  (void) spa_destroy(spa_name);
                  unload_wkey = B_FALSE; /* spa_destroy() unloads wrapping keys */
          }
  
  pool_props_bad:
          nvlist_free(rootprops);
          nvlist_free(zplprops);
          nvlist_free(config);
          nvlist_free(props);
          dsl_crypto_params_free(dcp, unload_wkey && !!error);
  
          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 = NULL;
          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)
   * zc_flags             scrub pause/resume flag (pool_scrub_cmd_t)
   */
  static int
  zfs_ioc_pool_scan(zfs_cmd_t *zc)
  {
          spa_t *spa;
          int error;
  
          if (zc->zc_flags >= POOL_SCRUB_FLAGS_END)
                  return (SET_ERROR(EINVAL));
  
          if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                  return (error);
  
          if (zc->zc_flags == POOL_SCRUB_PAUSE)
                  error = spa_scrub_pause_resume(spa, POOL_SCRUB_PAUSE);
          else 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_flags(zc->zc_name, B_TRUE,
              FTAG, &os)) != 0)
                  return (error);
          if (dmu_objset_type(os) != DMU_OST_ZFS) {
                  dmu_objset_rele_flags(os, B_TRUE, FTAG);
                  return (SET_ERROR(EINVAL));
          }
          error = zfs_obj_to_path(os, zc->zc_obj, zc->zc_value,
              sizeof (zc->zc_value));
          dmu_objset_rele_flags(os, B_TRUE, 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_flags(zc->zc_name, B_TRUE,
              FTAG, &os)) != 0)
                  return (error);
          if (dmu_objset_type(os) != DMU_OST_ZFS) {
                  dmu_objset_rele_flags(os, B_TRUE, 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_flags(os, B_TRUE, 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_guid              guid of vdev to remove
   * zc_cookie            cancel removal
   */
  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);
          if (zc->zc_cookie != 0) {
                  error = spa_vdev_remove_cancel(spa);
          } else {
                  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_EXTERNAL_PERSIST)
                          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;
  
          case VDEV_STATE_REMOVED:
                  error = vdev_remove_wanted(spa, zc->zc_guid);
                  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;
          nvlist_t *config;
          int replacing = zc->zc_cookie;
          int rebuild = zc->zc_simple;
          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,
                      rebuild);
                  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;
          const 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;
          const 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_simple && 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 without owning
                   */
                  if (!zc->zc_objset_stats.dds_inconsistent &&
                      dmu_objset_type(os) == DMU_OST_ZVOL) {
                          error = zvol_get_stats(os, nv);
                          if (error == EIO) {
                                  nvlist_free(nv);
                                  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);
  }
  
  /*
   * 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 && zfs_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_src        iteration range nvlist
   * zc_nvlist_src_size   size of iteration range 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)
  {
          int error;
          objset_t *os, *ossnap;
          dsl_dataset_t *ds;
          uint64_t min_txg = 0, max_txg = 0;
  
          if (zc->zc_nvlist_src_size != 0) {
                  nvlist_t *props = NULL;
                  error = get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
                      zc->zc_iflags, &props);
                  if (error != 0)
                          return (error);
                  (void) nvlist_lookup_uint64(props, SNAP_ITER_MIN_TXG,
                      &min_txg);
                  (void) nvlist_lookup_uint64(props, SNAP_ITER_MAX_TXG,
                      &max_txg);
                  nvlist_free(props);
          }
  
          error = dmu_objset_hold(zc->zc_name, FTAG, &os);
          if (error != 0) {
                  return (error == ENOENT ? SET_ERROR(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));
          }
  
          while (error == 0) {
                  if (issig(JUSTLOOKING) && issig(FORREAL)) {
                          error = SET_ERROR(EINTR);
                          break;
                  }
  
                  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 == ENOENT) {
                          error = SET_ERROR(ESRCH);
                          break;
                  } else if (error != 0) {
                          break;
                  }
  
                  error = dsl_dataset_hold_obj(dmu_objset_pool(os), zc->zc_obj,
                      FTAG, &ds);
                  if (error != 0)
                          break;
  
                  if ((min_txg != 0 && dsl_get_creationtxg(ds) < min_txg) ||
                      (max_txg != 0 && dsl_get_creationtxg(ds) > max_txg)) {
                          dsl_dataset_rele(ds, FTAG);
                          /* undo snapshot name append */
                          *(strchr(zc->zc_name, '@') + 1) = '\0';
                          /* skip snapshot */
                          continue;
                  }
  
                  if (zc->zc_simple) {
                          dsl_dataset_fast_stat(ds, &zc->zc_objset_stats);
                          dsl_dataset_rele(ds, FTAG);
                          break;
                  }
  
                  if ((error = dmu_objset_from_ds(ds, &ossnap)) != 0) {
                          dsl_dataset_rele(ds, FTAG);
                          break;
                  }
                  if ((error = zfs_ioc_objset_stats_impl(zc, ossnap)) != 0) {
                          dsl_dataset_rele(ds, FTAG);
                          break;
                  }
                  dsl_dataset_rele(ds, FTAG);
                  break;
          }
  
          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 *dash, *domain;
          zfs_userquota_prop_t type;
          uint64_t rid;
          uint64_t quota;
          zfsvfs_t *zfsvfs;
          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 = zfsvfs_hold(dsname, FTAG, &zfsvfs, B_FALSE);
          if (err == 0) {
                  err = zfs_set_userquota(zfsvfs, type, domain, rid, quota);
                  zfsvfs_rele(zfsvfs, 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 = 0;
          const char *strval = NULL;
          int err = -1;
  
          if (prop == ZPROP_USERPROP) {
                  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);
          }
  
          /* all special properties are numeric except for keylocation */
          if (zfs_prop_get_type(prop) == PROP_TYPE_STRING) {
                  strval = fnvpair_value_string(pair);
          } else {
                  intval = fnvpair_value_uint64(pair);
          }
  
          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_KEYLOCATION:
                  err = dsl_crypto_can_set_keylocation(dsname, strval);
  
                  /*
                   * 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_COMPRESSION:
                  err = dsl_dataset_set_compression(dsname, source, intval);
                  /*
                   * 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_VOLSIZE:
                  err = zvol_set_volsize(dsname, intval);
                  break;
          case ZFS_PROP_SNAPDEV:
                  err = zvol_set_snapdev(dsname, source, intval);
                  break;
          case ZFS_PROP_VOLMODE:
                  err = zvol_set_volmode(dsname, source, intval);
                  break;
          case ZFS_PROP_VERSION:
          {
                  zfsvfs_t *zfsvfs;
  
                  if ((err = zfsvfs_hold(dsname, FTAG, &zfsvfs, B_TRUE)) != 0)
                          break;
  
                  err = zfs_set_version(zfsvfs, intval);
                  zfsvfs_rele(zfsvfs, FTAG);
  
                  if (err == 0 && intval >= ZPL_VERSION_USERSPACE) {
                          zfs_cmd_t *zc;
  
                          zc = kmem_zalloc(sizeof (zfs_cmd_t), KM_SLEEP);
                          (void) strlcpy(zc->zc_name, dsname,
                              sizeof (zc->zc_name));
                          (void) zfs_ioc_userspace_upgrade(zc);
                          (void) zfs_ioc_id_quota_upgrade(zc);
                          kmem_free(zc, sizeof (zfs_cmd_t));
                  }
                  break;
          }
          default:
                  err = -1;
          }
  
          return (err);
  }
  
  static boolean_t
  zfs_is_namespace_prop(zfs_prop_t prop)
  {
          switch (prop) {
  
          case ZFS_PROP_ATIME:
          case ZFS_PROP_RELATIME:
          case ZFS_PROP_DEVICES:
          case ZFS_PROP_EXEC:
          case ZFS_PROP_SETUID:
          case ZFS_PROP_READONLY:
          case ZFS_PROP_XATTR:
          case ZFS_PROP_NBMAND:
                  return (B_TRUE);
  
          default:
                  return (B_FALSE);
          }
  }
  
  /*
   * 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;
          int err;
          uint64_t intval;
          const char *strval;
          boolean_t should_update_mount_cache = B_FALSE;
  
          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);
                  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 && source == ZPROP_SRC_INHERITED) {
                          /* inherited properties are expected to be booleans */
                          if (nvpair_type(propval) != DATA_TYPE_BOOLEAN)
                                  err = SET_ERROR(EINVAL);
                  } else if (err == 0 && prop == ZPROP_USERPROP) {
                          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(ZFS_ERR_BADPROP);
                                          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) {
                          if (source == ZPROP_SRC_INHERITED)
                                  err = -1; /* does not need special handling */
                          else
                                  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 (zfs_is_namespace_prop(prop))
                          should_update_mount_cache = B_TRUE;
          }
  
          if (nvl != retrynvl && !nvlist_empty(retrynvl)) {
                  nvl = retrynvl;
                  goto retry;
          }
  
          if (nvlist_empty(genericnvl))
                  goto out;
  
          /*
           * Try to set them all in one batch.
           */
          err = dsl_props_set(dsname, source, genericnvl);
          if (err == 0)
                  goto out;
  
          /*
           * If batching 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);
  
                  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 if (nvpair_type(propval) == DATA_TYPE_BOOLEAN) {
                          err = dsl_prop_inherit(dsname, propname, source);
                  } 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;
                  }
          }
  
  out:
          if (should_update_mount_cache)
                  zfs_ioctl_update_mount_cache(dsname);
  
          nvlist_free(genericnvl);
          nvlist_free(retrynvl);
  
          return (rv);
  }
  
  /*
   * Check that all the properties are valid user properties.
   */
  static int
  zfs_check_userprops(nvlist_t *nvl)
  {
          nvpair_t *pair = NULL;
  
          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 (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 */
          nvlist_t *dummy;
          nvpair_t *pair;
          zprop_type_t type;
          int err;
  
          if (!received) {
                  /*
                   * 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_USERPROP && !zfs_prop_inheritable(prop))
                          return (SET_ERROR(EINVAL));
          }
  
          if (prop == ZPROP_USERPROP) {
                  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);
          }
  
          /*
           * zfs_prop_set_special() expects properties in the form of an
           * nvpair with type info.
           */
          dummy = fnvlist_alloc();
  
          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:
                  err = SET_ERROR(EINVAL);
                  goto errout;
          }
  
          pair = nvlist_next_nvpair(dummy, NULL);
          if (pair == NULL) {
                  err = SET_ERROR(EINVAL);
          } else {
                  err = zfs_prop_set_special(zc->zc_name, source, pair);
                  if (err == -1) /* property is not "special", needs handling */
                          err = dsl_prop_inherit(zc->zc_name, zc->zc_value,
                              source);
          }
  
  errout:
          nvlist_free(dummy);
          return (err);
  }
  
  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_write_cachefile(spa, B_FALSE, B_TRUE, B_FALSE);
                  }
                  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);
  }
  
  /*
   * innvl: {
   *     "vdevprops_set_vdev" -> guid
   *     "vdevprops_set_props" -> { prop -> value }
   * }
   *
   * outnvl: propname -> error code (int32)
   */
  static const zfs_ioc_key_t zfs_keys_vdev_set_props[] = {
          {ZPOOL_VDEV_PROPS_SET_VDEV,     DATA_TYPE_UINT64,       0},
          {ZPOOL_VDEV_PROPS_SET_PROPS,    DATA_TYPE_NVLIST,       0}
  };
  
  static int
  zfs_ioc_vdev_set_props(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          spa_t *spa;
          int error;
          vdev_t *vd;
          uint64_t vdev_guid;
  
          /* Early validation */
          if (nvlist_lookup_uint64(innvl, ZPOOL_VDEV_PROPS_SET_VDEV,
              &vdev_guid) != 0)
                  return (SET_ERROR(EINVAL));
  
          if (outnvl == NULL)
                  return (SET_ERROR(EINVAL));
  
          if ((error = spa_open(poolname, &spa, FTAG)) != 0)
                  return (error);
  
          ASSERT(spa_writeable(spa));
  
          if ((vd = spa_lookup_by_guid(spa, vdev_guid, B_TRUE)) == NULL) {
                  spa_close(spa, FTAG);
                  return (SET_ERROR(ENOENT));
          }
  
          error = vdev_prop_set(vd, innvl, outnvl);
  
          spa_close(spa, FTAG);
  
          return (error);
  }
  
  /*
   * innvl: {
   *     "vdevprops_get_vdev" -> guid
   *     (optional) "vdevprops_get_props" -> { propname -> propid }
   * }
   *
   * outnvl: propname -> value
   */
  static const zfs_ioc_key_t zfs_keys_vdev_get_props[] = {
          {ZPOOL_VDEV_PROPS_GET_VDEV,     DATA_TYPE_UINT64,       0},
          {ZPOOL_VDEV_PROPS_GET_PROPS,    DATA_TYPE_NVLIST,       ZK_OPTIONAL}
  };
  
  static int
  zfs_ioc_vdev_get_props(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          spa_t *spa;
          int error;
          vdev_t *vd;
          uint64_t vdev_guid;
  
          /* Early validation */
          if (nvlist_lookup_uint64(innvl, ZPOOL_VDEV_PROPS_GET_VDEV,
              &vdev_guid) != 0)
                  return (SET_ERROR(EINVAL));
  
          if (outnvl == NULL)
                  return (SET_ERROR(EINVAL));
  
          if ((error = spa_open(poolname, &spa, FTAG)) != 0)
                  return (error);
  
          if ((vd = spa_lookup_by_guid(spa, vdev_guid, B_TRUE)) == NULL) {
                  spa_close(spa, FTAG);
                  return (SET_ERROR(ENOENT));
          }
  
          error = vdev_prop_get(vd, innvl, outnvl);
  
          spa_close(spa, FTAG);
  
          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 (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);
  }
  
  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);
  
          /* parent dataset must be a filesystem */
          if (os != NULL && os->os_phys->os_type != DMU_OST_ZFS)
                  return (SET_ERROR(ZFS_ERR_WRONG_PARENT));
  
          /*
           * 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];
          spa_t *spa;
          uint64_t spa_vers;
          int error;
  
          zfs_get_parent(dataset, parentname, sizeof (parentname));
  
          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 }
   *     (optional) "hidden_args" -> { "wkeydata" -> value }
   *         raw uint8_t array of encryption wrapping key data (32 bytes)
   * }
   *
   * outnvl: propname -> error code (int32)
   */
  
  static const zfs_ioc_key_t zfs_keys_create[] = {
          {"type",        DATA_TYPE_INT32,        0},
          {"props",       DATA_TYPE_NVLIST,       ZK_OPTIONAL},
          {"hidden_args", DATA_TYPE_NVLIST,       ZK_OPTIONAL},
  };
  
  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;
          nvlist_t *hidden_args = NULL;
          void (*cbfunc)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx);
          dmu_objset_type_t type;
          boolean_t is_insensitive = B_FALSE;
          dsl_crypto_params_t *dcp = NULL;
  
          type = (dmu_objset_type_t)fnvlist_lookup_int32(innvl, "type");
          (void) nvlist_lookup_nvlist(innvl, "props", &nvprops);
          (void) nvlist_lookup_nvlist(innvl, ZPOOL_HIDDEN_ARGS, &hidden_args);
  
          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 = dsl_crypto_params_create_nvlist(DCP_CMD_NONE, nvprops,
              hidden_args, &dcp);
          if (error != 0) {
                  nvlist_free(zct.zct_zplprops);
                  return (error);
          }
  
          error = dmu_objset_create(fsname, type,
              is_insensitive ? DS_FLAG_CI_DATASET : 0, dcp, cbfunc, &zct);
  
          nvlist_free(zct.zct_zplprops);
          dsl_crypto_params_free(dcp, !!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) {
                          spa_t *spa;
                          int error2;
  
                          /*
                           * Volumes will return EBUSY and cannot be destroyed
                           * until all asynchronous minor handling (e.g. from
                           * setting the volmode property) 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 }
   *     (optional) "hidden_args" -> { "wkeydata" -> value }
   *         raw uint8_t array of encryption wrapping key data (32 bytes)
   * }
   *
   * outputs:
   * outnvl: propname -> error code (int32)
   */
  static const zfs_ioc_key_t zfs_keys_clone[] = {
          {"origin",      DATA_TYPE_STRING,       0},
          {"props",       DATA_TYPE_NVLIST,       ZK_OPTIONAL},
          {"hidden_args", DATA_TYPE_NVLIST,       ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_clone(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          int error = 0;
          nvlist_t *nvprops = NULL;
          const char *origin_name;
  
          origin_name = fnvlist_lookup_string(innvl, "origin");
          (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);
  
          /*
           * 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);
  }
  
  static const zfs_ioc_key_t zfs_keys_remap[] = {
          /* no nvl keys */
  };
  
  static int
  zfs_ioc_remap(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          /* This IOCTL is no longer supported. */
          (void) fsname, (void) innvl, (void) outnvl;
          return (0);
  }
  
  /*
   * innvl: {
   *     "snaps" -> { snapshot1, snapshot2 }
   *     (optional) "props" -> { prop -> value (string) }
   * }
   *
   * outnvl: snapshot -> error code (int32)
   */
  static const zfs_ioc_key_t zfs_keys_snapshot[] = {
          {"snaps",       DATA_TYPE_NVLIST,       0},
          {"props",       DATA_TYPE_NVLIST,       ZK_OPTIONAL},
  };
  
  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;
  
          (void) nvlist_lookup_nvlist(innvl, "props", &props);
          if (!nvlist_empty(props) &&
              zfs_earlier_version(poolname, SPA_VERSION_SNAP_PROPS))
                  return (SET_ERROR(ENOTSUP));
          if ((error = zfs_check_userprops(props)) != 0)
                  return (error);
  
          snaps = fnvlist_lookup_nvlist(innvl, "snaps");
          poollen = strlen(poolname);
          for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
              pair = nvlist_next_nvpair(snaps, pair)) {
                  const char *name = nvpair_name(pair);
                  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));
  
                  /*
                   * Check for permission to set the properties on the fs.
                   */
                  if (!nvlist_empty(props)) {
                          *cp = '\0';
                          error = zfs_secpolicy_write_perms(name,
                              ZFS_DELEG_PERM_USERPROP, CRED());
                          *cp = '@';
                          if (error != 0)
                                  return (error);
                  }
  
                  /* This must be the only snap of this fs. */
                  for (nvpair_t *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
   */
  static const zfs_ioc_key_t zfs_keys_log_history[] = {
          {"message",     DATA_TYPE_STRING,       0},
  };
  
  static int
  zfs_ioc_log_history(const char *unused, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) unused, (void) outnvl;
          const char *message;
          char *poolname;
          spa_t *spa;
          int error;
  
          /*
           * 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);
          kmem_strfree(poolname);
          if (error != 0)
                  return (error);
  
          message = fnvlist_lookup_string(innvl, "message");
  
          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);
  }
  
  /*
   * This ioctl is used to set the bootenv configuration on the current
   * pool. This configuration is stored in the second padding area of the label,
   * and it is used by the bootloader(s) to store the bootloader and/or system
   * specific data.
   * The data is stored as nvlist data stream, and is protected by
   * an embedded checksum.
   * The version can have two possible values:
   * VB_RAW: nvlist should have key GRUB_ENVMAP, value DATA_TYPE_STRING.
   * VB_NVLIST: nvlist with arbitrary <key, value> pairs.
   */
  static const zfs_ioc_key_t zfs_keys_set_bootenv[] = {
          {"version",     DATA_TYPE_UINT64,       0},
          {"<keys>",      DATA_TYPE_ANY, ZK_OPTIONAL | ZK_WILDCARDLIST},
  };
  
  static int
  zfs_ioc_set_bootenv(const char *name, nvlist_t *innvl, nvlist_t *outnvl)
  {
          int error;
          spa_t *spa;
  
          if ((error = spa_open(name, &spa, FTAG)) != 0)
                  return (error);
          spa_vdev_state_enter(spa, SCL_ALL);
          error = vdev_label_write_bootenv(spa->spa_root_vdev, innvl);
          (void) spa_vdev_state_exit(spa, NULL, 0);
          spa_close(spa, FTAG);
          return (error);
  }
  
  static const zfs_ioc_key_t zfs_keys_get_bootenv[] = {
          /* no nvl keys */
  };
  
  static int
  zfs_ioc_get_bootenv(const char *name, nvlist_t *innvl, nvlist_t *outnvl)
  {
          spa_t *spa;
          int error;
  
          if ((error = spa_open(name, &spa, FTAG)) != 0)
                  return (error);
          spa_vdev_state_enter(spa, SCL_ALL);
          error = vdev_label_read_bootenv(spa->spa_root_vdev, outnvl);
          (void) spa_vdev_state_exit(spa, NULL, 0);
          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.
   */
  void
  zfs_unmount_snap(const char *snapname)
  {
          if (strchr(snapname, '@') == NULL)
                  return;
  
          (void) zfsctl_snapshot_unmount(snapname, MNT_FORCE);
  }
  
  static int
  zfs_unmount_snap_cb(const char *snapname, void *arg)
  {
          (void) arg;
          zfs_unmount_snap(snapname);
          return (0);
  }
  
  /*
   * 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);
                  zfs_unmount_snap(originname);
          } else {
                  dmu_objset_rele(os, FTAG);
          }
  }
  
  /*
   * innvl: {
   *     "snaps" -> { snapshot1, snapshot2 }
   *     (optional boolean) "defer"
   * }
   *
   * outnvl: snapshot -> error code (int32)
   */
  static const zfs_ioc_key_t zfs_keys_destroy_snaps[] = {
          {"snaps",       DATA_TYPE_NVLIST,       0},
          {"defer",       DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_destroy_snaps(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          int poollen;
          nvlist_t *snaps;
          nvpair_t *pair;
          boolean_t defer;
          spa_t *spa;
  
          snaps = fnvlist_lookup_nvlist(innvl, "snaps");
          defer = nvlist_exists(innvl, "defer");
  
          poollen = strlen(poolname);
          for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
              pair = nvlist_next_nvpair(snaps, pair)) {
                  const char *name = nvpair_name(pair);
  
                  /*
                   * The snap must be in the specified pool to prevent the
                   * invalid removal of zvol minors below.
                   */
                  if (strncmp(name, poolname, poollen) != 0 ||
                      (name[poollen] != '/' && name[poollen] != '@'))
                          return (SET_ERROR(EXDEV));
  
                  zfs_unmount_snap(nvpair_name(pair));
                  if (spa_open(name, &spa, FTAG) == 0) {
                          zvol_remove_minors(spa, name, B_TRUE);
                          spa_close(spa, FTAG);
                  }
          }
  
          return (dsl_destroy_snapshots_nvl(snaps, defer, outnvl));
  }
  
  /*
   * Create bookmarks. The bookmark names are of the form <fs>#<bmark>.
   * All bookmarks and snapshots must be in the same pool.
   * dsl_bookmark_create_nvl_validate describes the nvlist schema in more detail.
   *
   * innvl: {
   *     new_bookmark1 -> existing_snapshot,
   *     new_bookmark2 -> existing_bookmark,
   * }
   *
   * outnvl: bookmark -> error code (int32)
   *
   */
  static const zfs_ioc_key_t zfs_keys_bookmark[] = {
          {"<bookmark>...",       DATA_TYPE_STRING,       ZK_WILDCARDLIST},
  };
  
  static int
  zfs_ioc_bookmark(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) poolname;
          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 const zfs_ioc_key_t zfs_keys_get_bookmarks[] = {
          {"<property>...", DATA_TYPE_BOOLEAN, ZK_WILDCARDLIST | ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_get_bookmarks(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          return (dsl_get_bookmarks(fsname, innvl, outnvl));
  }
  
  /*
   * innvl is not used.
   *
   * outnvl: {
   *     property 1, property 2, ...
   * }
   *
   */
  static const zfs_ioc_key_t zfs_keys_get_bookmark_props[] = {
          /* no nvl keys */
  };
  
  static int
  zfs_ioc_get_bookmark_props(const char *bookmark, nvlist_t *innvl,
      nvlist_t *outnvl)
  {
          (void) innvl;
          char fsname[ZFS_MAX_DATASET_NAME_LEN];
          char *bmname;
  
          bmname = strchr(bookmark, '#');
          if (bmname == NULL)
                  return (SET_ERROR(EINVAL));
          bmname++;
  
          (void) strlcpy(fsname, bookmark, sizeof (fsname));
          *(strchr(fsname, '#')) = '\0';
  
          return (dsl_get_bookmark_props(fsname, bmname, outnvl));
  }
  
  /*
   * innvl: {
   *     bookmark name 1, bookmark name 2
   * }
   *
   * outnvl: bookmark -> error code (int32)
   *
   */
  static const zfs_ioc_key_t zfs_keys_destroy_bookmarks[] = {
          {"<bookmark>...",       DATA_TYPE_BOOLEAN,      ZK_WILDCARDLIST},
  };
  
  static int
  zfs_ioc_destroy_bookmarks(const char *poolname, nvlist_t *innvl,
      nvlist_t *outnvl)
  {
          int error, poollen;
  
          poollen = strlen(poolname);
          for (nvpair_t *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);
  }
  
  static const zfs_ioc_key_t zfs_keys_channel_program[] = {
          {"program",     DATA_TYPE_STRING,               0},
          {"arg",         DATA_TYPE_ANY,                  0},
          {"sync",        DATA_TYPE_BOOLEAN_VALUE,        ZK_OPTIONAL},
          {"instrlimit",  DATA_TYPE_UINT64,               ZK_OPTIONAL},
          {"memlimit",    DATA_TYPE_UINT64,               ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_channel_program(const char *poolname, nvlist_t *innvl,
      nvlist_t *outnvl)
  {
          char *program;
          uint64_t instrlimit, memlimit;
          boolean_t sync_flag;
          nvpair_t *nvarg = NULL;
  
          program = fnvlist_lookup_string(innvl, ZCP_ARG_PROGRAM);
          if (0 != nvlist_lookup_boolean_value(innvl, ZCP_ARG_SYNC, &sync_flag)) {
                  sync_flag = B_TRUE;
          }
          if (0 != nvlist_lookup_uint64(innvl, ZCP_ARG_INSTRLIMIT, &instrlimit)) {
                  instrlimit = ZCP_DEFAULT_INSTRLIMIT;
          }
          if (0 != nvlist_lookup_uint64(innvl, ZCP_ARG_MEMLIMIT, &memlimit)) {
                  memlimit = ZCP_DEFAULT_MEMLIMIT;
          }
          nvarg = fnvlist_lookup_nvpair(innvl, ZCP_ARG_ARGLIST);
  
          if (instrlimit == 0 || instrlimit > zfs_lua_max_instrlimit)
                  return (SET_ERROR(EINVAL));
          if (memlimit == 0 || memlimit > zfs_lua_max_memlimit)
                  return (SET_ERROR(EINVAL));
  
          return (zcp_eval(poolname, program, sync_flag, instrlimit, memlimit,
              nvarg, outnvl));
  }
  
  /*
   * innvl: unused
   * outnvl: empty
   */
  static const zfs_ioc_key_t zfs_keys_pool_checkpoint[] = {
          /* no nvl keys */
  };
  
  static int
  zfs_ioc_pool_checkpoint(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) innvl, (void) outnvl;
          return (spa_checkpoint(poolname));
  }
  
  /*
   * innvl: unused
   * outnvl: empty
   */
  static const zfs_ioc_key_t zfs_keys_pool_discard_checkpoint[] = {
          /* no nvl keys */
  };
  
  static int
  zfs_ioc_pool_discard_checkpoint(const char *poolname, nvlist_t *innvl,
      nvlist_t *outnvl)
  {
          (void) innvl, (void) outnvl;
          return (spa_checkpoint_discard(poolname));
  }
  
  /*
   * inputs:
   * zc_name              name of dataset to destroy
   * zc_defer_destroy     mark for deferred destroy
   *
   * outputs:             none
   */
  static int
  zfs_ioc_destroy(zfs_cmd_t *zc)
  {
          objset_t *os;
          dmu_objset_type_t ost;
          int err;
  
          err = dmu_objset_hold(zc->zc_name, FTAG, &os);
          if (err != 0)
                  return (err);
          ost = dmu_objset_type(os);
          dmu_objset_rele(os, FTAG);
  
          if (ost == DMU_OST_ZFS)
                  zfs_unmount_snap(zc->zc_name);
  
          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];
  
                          if (snprintf(namebuf, sizeof (namebuf), "%s/%s",
                              zc->zc_name, recv_clone_name) >=
                              sizeof (namebuf))
                                  return (SET_ERROR(EINVAL));
  
                          /*
                           * 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 = SET_ERROR(EEXIST);
                  }
          }
  
          return (err);
  }
  
  /*
   * innvl: {
   *     "initialize_command" -> POOL_INITIALIZE_{CANCEL|START|SUSPEND} (uint64)
   *     "initialize_vdevs": { -> guids to initialize (nvlist)
   *         "vdev_path_1": vdev_guid_1, (uint64),
   *         "vdev_path_2": vdev_guid_2, (uint64),
   *         ...
   *     },
   * }
   *
   * outnvl: {
   *     "initialize_vdevs": { -> initialization errors (nvlist)
   *         "vdev_path_1": errno, see function body for possible errnos (uint64)
   *         "vdev_path_2": errno, ... (uint64)
   *         ...
   *     }
   * }
   *
   * EINVAL is returned for an unknown commands or if any of the provided vdev
   * guids have be specified with a type other than uint64.
   */
  static const zfs_ioc_key_t zfs_keys_pool_initialize[] = {
          {ZPOOL_INITIALIZE_COMMAND,      DATA_TYPE_UINT64,       0},
          {ZPOOL_INITIALIZE_VDEVS,        DATA_TYPE_NVLIST,       0}
  };
  
  static int
  zfs_ioc_pool_initialize(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          uint64_t cmd_type;
          if (nvlist_lookup_uint64(innvl, ZPOOL_INITIALIZE_COMMAND,
              &cmd_type) != 0) {
                  return (SET_ERROR(EINVAL));
          }
  
          if (!(cmd_type == POOL_INITIALIZE_CANCEL ||
              cmd_type == POOL_INITIALIZE_START ||
              cmd_type == POOL_INITIALIZE_SUSPEND)) {
                  return (SET_ERROR(EINVAL));
          }
  
          nvlist_t *vdev_guids;
          if (nvlist_lookup_nvlist(innvl, ZPOOL_INITIALIZE_VDEVS,
              &vdev_guids) != 0) {
                  return (SET_ERROR(EINVAL));
          }
  
          for (nvpair_t *pair = nvlist_next_nvpair(vdev_guids, NULL);
              pair != NULL; pair = nvlist_next_nvpair(vdev_guids, pair)) {
                  uint64_t vdev_guid;
                  if (nvpair_value_uint64(pair, &vdev_guid) != 0) {
                          return (SET_ERROR(EINVAL));
                  }
          }
  
          spa_t *spa;
          int error = spa_open(poolname, &spa, FTAG);
          if (error != 0)
                  return (error);
  
          nvlist_t *vdev_errlist = fnvlist_alloc();
          int total_errors = spa_vdev_initialize(spa, vdev_guids, cmd_type,
              vdev_errlist);
  
          if (fnvlist_size(vdev_errlist) > 0) {
                  fnvlist_add_nvlist(outnvl, ZPOOL_INITIALIZE_VDEVS,
                      vdev_errlist);
          }
          fnvlist_free(vdev_errlist);
  
          spa_close(spa, FTAG);
          return (total_errors > 0 ? SET_ERROR(EINVAL) : 0);
  }
  
  /*
   * innvl: {
   *     "trim_command" -> POOL_TRIM_{CANCEL|START|SUSPEND} (uint64)
   *     "trim_vdevs": { -> guids to TRIM (nvlist)
   *         "vdev_path_1": vdev_guid_1, (uint64),
   *         "vdev_path_2": vdev_guid_2, (uint64),
   *         ...
   *     },
   *     "trim_rate" -> Target TRIM rate in bytes/sec.
   *     "trim_secure" -> Set to request a secure TRIM.
   * }
   *
   * outnvl: {
   *     "trim_vdevs": { -> TRIM errors (nvlist)
   *         "vdev_path_1": errno, see function body for possible errnos (uint64)
   *         "vdev_path_2": errno, ... (uint64)
   *         ...
   *     }
   * }
   *
   * EINVAL is returned for an unknown commands or if any of the provided vdev
   * guids have be specified with a type other than uint64.
   */
  static const zfs_ioc_key_t zfs_keys_pool_trim[] = {
          {ZPOOL_TRIM_COMMAND,    DATA_TYPE_UINT64,               0},
          {ZPOOL_TRIM_VDEVS,      DATA_TYPE_NVLIST,               0},
          {ZPOOL_TRIM_RATE,       DATA_TYPE_UINT64,               ZK_OPTIONAL},
          {ZPOOL_TRIM_SECURE,     DATA_TYPE_BOOLEAN_VALUE,        ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_pool_trim(const char *poolname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          uint64_t cmd_type;
          if (nvlist_lookup_uint64(innvl, ZPOOL_TRIM_COMMAND, &cmd_type) != 0)
                  return (SET_ERROR(EINVAL));
  
          if (!(cmd_type == POOL_TRIM_CANCEL ||
              cmd_type == POOL_TRIM_START ||
              cmd_type == POOL_TRIM_SUSPEND)) {
                  return (SET_ERROR(EINVAL));
          }
  
          nvlist_t *vdev_guids;
          if (nvlist_lookup_nvlist(innvl, ZPOOL_TRIM_VDEVS, &vdev_guids) != 0)
                  return (SET_ERROR(EINVAL));
  
          for (nvpair_t *pair = nvlist_next_nvpair(vdev_guids, NULL);
              pair != NULL; pair = nvlist_next_nvpair(vdev_guids, pair)) {
                  uint64_t vdev_guid;
                  if (nvpair_value_uint64(pair, &vdev_guid) != 0) {
                          return (SET_ERROR(EINVAL));
                  }
          }
  
          /* Optional, defaults to maximum rate when not provided */
          uint64_t rate;
          if (nvlist_lookup_uint64(innvl, ZPOOL_TRIM_RATE, &rate) != 0)
                  rate = 0;
  
          /* Optional, defaults to standard TRIM when not provided */
          boolean_t secure;
          if (nvlist_lookup_boolean_value(innvl, ZPOOL_TRIM_SECURE,
              &secure) != 0) {
                  secure = B_FALSE;
          }
  
          spa_t *spa;
          int error = spa_open(poolname, &spa, FTAG);
          if (error != 0)
                  return (error);
  
          nvlist_t *vdev_errlist = fnvlist_alloc();
          int total_errors = spa_vdev_trim(spa, vdev_guids, cmd_type,
              rate, !!zfs_trim_metaslab_skip, secure, vdev_errlist);
  
          if (fnvlist_size(vdev_errlist) > 0)
                  fnvlist_add_nvlist(outnvl, ZPOOL_TRIM_VDEVS, vdev_errlist);
  
          fnvlist_free(vdev_errlist);
  
          spa_close(spa, FTAG);
          return (total_errors > 0 ? SET_ERROR(EINVAL) : 0);
  }
  
  /*
   * This ioctl waits for activity of a particular type to complete. If there is
   * no activity of that type in progress, it returns immediately, and the
   * returned value "waited" is false. If there is activity in progress, and no
   * tag is passed in, the ioctl blocks until all activity of that type is
   * complete, and then returns with "waited" set to true.
   *
   * If a tag is provided, it identifies a particular instance of an activity to
   * wait for. Currently, this is only valid for use with 'initialize', because
   * that is the only activity for which there can be multiple instances running
   * concurrently. In the case of 'initialize', the tag corresponds to the guid of
   * the vdev on which to wait.
   *
   * If a thread waiting in the ioctl receives a signal, the call will return
   * immediately, and the return value will be EINTR.
   *
   * innvl: {
   *     "wait_activity" -> int32_t
   *     (optional) "wait_tag" -> uint64_t
   * }
   *
   * outnvl: "waited" -> boolean_t
   */
  static const zfs_ioc_key_t zfs_keys_pool_wait[] = {
          {ZPOOL_WAIT_ACTIVITY,   DATA_TYPE_INT32,                0},
          {ZPOOL_WAIT_TAG,        DATA_TYPE_UINT64,               ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_wait(const char *name, nvlist_t *innvl, nvlist_t *outnvl)
  {
          int32_t activity;
          uint64_t tag;
          boolean_t waited;
          int error;
  
          if (nvlist_lookup_int32(innvl, ZPOOL_WAIT_ACTIVITY, &activity) != 0)
                  return (EINVAL);
  
          if (nvlist_lookup_uint64(innvl, ZPOOL_WAIT_TAG, &tag) == 0)
                  error = spa_wait_tag(name, activity, tag, &waited);
          else
                  error = spa_wait(name, activity, &waited);
  
          if (error == 0)
                  fnvlist_add_boolean_value(outnvl, ZPOOL_WAIT_WAITED, waited);
  
          return (error);
  }
  
  /*
   * This ioctl waits for activity of a particular type to complete. If there is
   * no activity of that type in progress, it returns immediately, and the
   * returned value "waited" is false. If there is activity in progress, and no
   * tag is passed in, the ioctl blocks until all activity of that type is
   * complete, and then returns with "waited" set to true.
   *
   * If a thread waiting in the ioctl receives a signal, the call will return
   * immediately, and the return value will be EINTR.
   *
   * innvl: {
   *     "wait_activity" -> int32_t
   * }
   *
   * outnvl: "waited" -> boolean_t
   */
  static const zfs_ioc_key_t zfs_keys_fs_wait[] = {
          {ZFS_WAIT_ACTIVITY,     DATA_TYPE_INT32,                0},
  };
  
  static int
  zfs_ioc_wait_fs(const char *name, nvlist_t *innvl, nvlist_t *outnvl)
  {
          int32_t activity;
          boolean_t waited = B_FALSE;
          int error;
          dsl_pool_t *dp;
          dsl_dir_t *dd;
          dsl_dataset_t *ds;
  
          if (nvlist_lookup_int32(innvl, ZFS_WAIT_ACTIVITY, &activity) != 0)
                  return (SET_ERROR(EINVAL));
  
          if (activity >= ZFS_WAIT_NUM_ACTIVITIES || activity < 0)
                  return (SET_ERROR(EINVAL));
  
          if ((error = dsl_pool_hold(name, FTAG, &dp)) != 0)
                  return (error);
  
          if ((error = dsl_dataset_hold(dp, name, FTAG, &ds)) != 0) {
                  dsl_pool_rele(dp, FTAG);
                  return (error);
          }
  
          dd = ds->ds_dir;
          mutex_enter(&dd->dd_activity_lock);
          dd->dd_activity_waiters++;
  
          /*
           * We get a long-hold here so that the dsl_dataset_t and dsl_dir_t
           * aren't evicted while we're waiting. Normally this is prevented by
           * holding the pool, but we can't do that while we're waiting since
           * that would prevent TXGs from syncing out. Some of the functionality
           * of long-holds (e.g. preventing deletion) is unnecessary for this
           * case, since we would cancel the waiters before proceeding with a
           * deletion. An alternative mechanism for keeping the dataset around
           * could be developed but this is simpler.
           */
          dsl_dataset_long_hold(ds, FTAG);
          dsl_pool_rele(dp, FTAG);
  
          error = dsl_dir_wait(dd, ds, activity, &waited);
  
          dsl_dataset_long_rele(ds, FTAG);
          dd->dd_activity_waiters--;
          if (dd->dd_activity_waiters == 0)
                  cv_signal(&dd->dd_activity_cv);
          mutex_exit(&dd->dd_activity_lock);
  
          dsl_dataset_rele(ds, FTAG);
  
          if (error == 0)
                  fnvlist_add_boolean_value(outnvl, ZFS_WAIT_WAITED, waited);
  
          return (error);
  }
  
  /*
   * fsname is name of dataset to rollback (to most recent snapshot)
   *
   * innvl may contain name of expected target snapshot
   *
   * outnvl: "target" -> name of most recent snapshot
   * }
   */
  static const zfs_ioc_key_t zfs_keys_rollback[] = {
          {"target",      DATA_TYPE_STRING,       ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_rollback(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          zfsvfs_t *zfsvfs;
          zvol_state_handle_t *zv;
          char *target = NULL;
          int error;
  
          (void) nvlist_lookup_string(innvl, "target", &target);
          if (target != NULL) {
                  const char *cp = strchr(target, '@');
  
                  /*
                   * 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));
          }
  
          if (getzfsvfs(fsname, &zfsvfs) == 0) {
                  dsl_dataset_t *ds;
  
                  ds = dmu_objset_ds(zfsvfs->z_os);
                  error = zfs_suspend_fs(zfsvfs);
                  if (error == 0) {
                          int resume_err;
  
                          error = dsl_dataset_rollback(fsname, target, zfsvfs,
                              outnvl);
                          resume_err = zfs_resume_fs(zfsvfs, ds);
                          error = error ? error : resume_err;
                  }
                  zfs_vfs_rele(zfsvfs);
          } else if ((zv = zvol_suspend(fsname)) != NULL) {
                  error = dsl_dataset_rollback(fsname, target, zvol_tag(zv),
                      outnvl);
                  zvol_resume(zv);
          } else {
                  error = dsl_dataset_rollback(fsname, target, NULL, outnvl);
          }
          return (error);
  }
  
  static int
  recursive_unmount(const char *fsname, void *arg)
  {
          const char *snapname = arg;
          char *fullname;
  
          fullname = kmem_asprintf("%s@%s", fsname, snapname);
          zfs_unmount_snap(fullname);
          kmem_strfree(fullname);
  
          return (0);
  }
  
  /*
   *
   * snapname is the snapshot to redact.
   * innvl: {
   *     "bookname" -> (string)
   *         shortname of the redaction bookmark to generate
   *     "snapnv" -> (nvlist, values ignored)
   *         snapshots to redact snapname with respect to
   * }
   *
   * outnvl is unused
   */
  
  static const zfs_ioc_key_t zfs_keys_redact[] = {
          {"bookname",            DATA_TYPE_STRING,       0},
          {"snapnv",              DATA_TYPE_NVLIST,       0},
  };
  
  static int
  zfs_ioc_redact(const char *snapname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) outnvl;
          nvlist_t *redactnvl = NULL;
          char *redactbook = NULL;
  
          if (nvlist_lookup_nvlist(innvl, "snapnv", &redactnvl) != 0)
                  return (SET_ERROR(EINVAL));
          if (fnvlist_num_pairs(redactnvl) == 0)
                  return (SET_ERROR(ENXIO));
          if (nvlist_lookup_string(innvl, "bookname", &redactbook) != 0)
                  return (SET_ERROR(EINVAL));
  
          return (dmu_redact_snap(snapname, redactnvl, redactbook));
  }
  
  /*
   * 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)
  {
          objset_t *os;
          dmu_objset_type_t ost;
          boolean_t recursive = zc->zc_cookie & 1;
          boolean_t nounmount = !!(zc->zc_cookie & 2);
          char *at;
          int err;
  
          /* "zfs rename" from and to ...%recv datasets should both fail */
          zc->zc_name[sizeof (zc->zc_name) - 1] = '\0';
          zc->zc_value[sizeof (zc->zc_value) - 1] = '\0';
          if (dataset_namecheck(zc->zc_name, NULL, NULL) != 0 ||
              dataset_namecheck(zc->zc_value, NULL, NULL) != 0 ||
              strchr(zc->zc_name, '%') || strchr(zc->zc_value, '%'))
                  return (SET_ERROR(EINVAL));
  
          err = dmu_objset_hold(zc->zc_name, FTAG, &os);
          if (err != 0)
                  return (err);
          ost = dmu_objset_type(os);
          dmu_objset_rele(os, FTAG);
  
          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 (ost == DMU_OST_ZFS && !nounmount) {
                          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, compval;
          int err;
  
          if (prop == ZPROP_USERPROP) {
                  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];
                          const char *uiq_prefix =
                              zfs_userquota_prop_prefixes[ZFS_PROP_USEROBJQUOTA];
                          const char *giq_prefix =
                              zfs_userquota_prop_prefixes[ZFS_PROP_GROUPOBJQUOTA];
                          const char *pq_prefix =
                              zfs_userquota_prop_prefixes[ZFS_PROP_PROJECTQUOTA];
                          const char *piq_prefix = zfs_userquota_prop_prefixes[\
                              ZFS_PROP_PROJECTOBJQUOTA];
  
                          if (strncmp(propname, uq_prefix,
                              strlen(uq_prefix)) == 0) {
                                  perm = ZFS_DELEG_PERM_USERQUOTA;
                          } else if (strncmp(propname, uiq_prefix,
                              strlen(uiq_prefix)) == 0) {
                                  perm = ZFS_DELEG_PERM_USEROBJQUOTA;
                          } else if (strncmp(propname, gq_prefix,
                              strlen(gq_prefix)) == 0) {
                                  perm = ZFS_DELEG_PERM_GROUPQUOTA;
                          } else if (strncmp(propname, giq_prefix,
                              strlen(giq_prefix)) == 0) {
                                  perm = ZFS_DELEG_PERM_GROUPOBJQUOTA;
                          } else if (strncmp(propname, pq_prefix,
                              strlen(pq_prefix)) == 0) {
                                  perm = ZFS_DELEG_PERM_PROJECTQUOTA;
                          } else if (strncmp(propname, piq_prefix,
                              strlen(piq_prefix)) == 0) {
                                  perm = ZFS_DELEG_PERM_PROJECTOBJQUOTA;
                          } else {
                                  /* {USER|GROUP|PROJECT}USED 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) {
                          compval = ZIO_COMPRESS_ALGO(intval);
                          if (compval >= ZIO_COMPRESS_GZIP_1 &&
                              compval <= ZIO_COMPRESS_GZIP_9 &&
                              zfs_earlier_version(dsname,
                              SPA_VERSION_GZIP_COMPRESSION)) {
                                  return (SET_ERROR(ENOTSUP));
                          }
  
                          if (compval == ZIO_COMPRESS_ZLE &&
                              zfs_earlier_version(dsname,
                              SPA_VERSION_ZLE_COMPRESSION))
                                  return (SET_ERROR(ENOTSUP));
  
                          if (compval == 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 (compval == ZIO_COMPRESS_ZSTD) {
                                  spa_t *spa;
  
                                  if ((err = spa_open(dsname, &spa, FTAG)) != 0)
                                          return (err);
  
                                  if (!spa_feature_is_enabled(spa,
                                      SPA_FEATURE_ZSTD_COMPRESS)) {
                                          spa_close(spa, FTAG);
                                          return (SET_ERROR(ENOTSUP));
                                  }
                                  spa_close(spa, FTAG);
                          }
                  }
                  break;
  
          case ZFS_PROP_COPIES:
                  if (zfs_earlier_version(dsname, SPA_VERSION_DITTO_BLOCKS))
                          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;
  
                          /*
                           * 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 ((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_SPECIAL_SMALL_BLOCKS:
                  /*
                   * This property could require the allocation classes
                   * feature to be active for setting, however we allow
                   * it so that tests of settable properties succeed.
                   * The CLI will issue a warning in this case.
                   */
                  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;
          case ZFS_PROP_CHECKSUM:
          case ZFS_PROP_DEDUP:
          {
                  spa_feature_t feature;
                  spa_t *spa;
                  int err;
  
                  /* dedup feature version checks */
                  if (prop == ZFS_PROP_DEDUP &&
                      zfs_earlier_version(dsname, SPA_VERSION_DEDUP))
                          return (SET_ERROR(ENOTSUP));
  
                  if (nvpair_type(pair) == DATA_TYPE_UINT64 &&
                      nvpair_value_uint64(pair, &intval) == 0) {
                          /* check prop value is enabled in features */
                          feature = zio_checksum_to_feature(
                              intval & ZIO_CHECKSUM_MASK);
                          if (feature == SPA_FEATURE_NONE)
                                  break;
  
                          if ((err = spa_open(dsname, &spa, FTAG)) != 0)
                                  return (err);
  
                          if (!spa_feature_is_enabled(spa, feature)) {
                                  spa_close(spa, FTAG);
                                  return (SET_ERROR(ENOTSUP));
                          }
                          spa_close(spa, FTAG);
                  }
                  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(const 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) strlcpy(zc->zc_name, dataset, sizeof (zc->zc_name));
          pair = nvlist_next_nvpair(props, NULL);
          while (pair != NULL) {
                  next_pair = nvlist_next_nvpair(props, pair);
  
                  (void) strlcpy(zc->zc_value, nvpair_name(pair),
                      sizeof (zc->zc_value));
                  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,
                  ZFS_PROP_KEYLOCATION,
                  /*
                   * Setting ZFS_PROP_SHARESMB requires the objset type to be
                   * known, which is not possible prior to receipt of raw sends.
                   */
                  ZFS_PROP_SHARESMB,
                  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);
  }
  
  static void
  zfs_allow_log_destroy(void *arg)
  {
          char *poolname = arg;
  
          if (poolname != NULL)
                  kmem_strfree(poolname);
  }
  
  #ifdef  ZFS_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 *recvprops,
      nvlist_t *localprops, nvlist_t *hidden_args, boolean_t force,
      boolean_t heal, boolean_t resumable, int input_fd,
      dmu_replay_record_t *begin_record, uint64_t *read_bytes,
      uint64_t *errflags, nvlist_t **errors)
  {
          dmu_recv_cookie_t drc;
          int error = 0;
          int props_error = 0;
          offset_t off, noff;
          nvlist_t *local_delayprops = NULL;
          nvlist_t *recv_delayprops = NULL;
          nvlist_t *inherited_delayprops = NULL;
          nvlist_t *origprops = NULL; /* existing properties */
          nvlist_t *origrecvd = NULL; /* existing received properties */
          boolean_t first_recvd_props = B_FALSE;
          boolean_t tofs_was_redacted;
          zfs_file_t *input_fp;
  
          *read_bytes = 0;
          *errflags = 0;
          *errors = fnvlist_alloc();
          off = 0;
  
          if ((input_fp = zfs_file_get(input_fd)) == NULL)
                  return (SET_ERROR(EBADF));
  
          noff = off = zfs_file_off(input_fp);
          error = dmu_recv_begin(tofs, tosnap, begin_record, force, heal,
              resumable, localprops, hidden_args, origin, &drc, input_fp,
              &off);
          if (error != 0)
                  goto out;
          tofs_was_redacted = dsl_get_redacted(drc.drc_ds);
  
          /*
           * 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 (recvprops != 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, &origrecvd) == 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(recvprops, origrecvd);
                          if (zfs_check_clearable(tofs, origrecvd, &errlist) != 0)
                                  (void) nvlist_merge(*errors, errlist, 0);
                          nvlist_free(errlist);
  
                          if (clear_received_props(tofs, origrecvd,
                              first_recvd_props ? NULL : recvprops) != 0)
                                  *errflags |= ZPROP_ERR_NOCLEAR;
                  } else {
                          *errflags |= ZPROP_ERR_NOCLEAR;
                  }
          }
  
          /*
           * Stash away existing properties so we can restore them on error unless
           * we're doing the first receive after SPA_VERSION_RECVD_PROPS, in which
           * case "origrecvd" will take care of that.
           */
          if (localprops != NULL && !drc.drc_newfs && !first_recvd_props) {
                  objset_t *os;
                  if (dmu_objset_hold(tofs, FTAG, &os) == 0) {
                          if (dsl_prop_get_all(os, &origprops) != 0) {
                                  *errflags |= ZPROP_ERR_NOCLEAR;
                          }
                          dmu_objset_rele(os, FTAG);
                  } else {
                          *errflags |= ZPROP_ERR_NOCLEAR;
                  }
          }
  
          if (recvprops != NULL) {
                  props_error = dsl_prop_set_hasrecvd(tofs);
  
                  if (props_error == 0) {
                          recv_delayprops = extract_delay_props(recvprops);
                          (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_RECEIVED,
                              recvprops, *errors);
                  }
          }
  
          if (localprops != NULL) {
                  nvlist_t *oprops = fnvlist_alloc();
                  nvlist_t *xprops = fnvlist_alloc();
                  nvpair_t *nvp = NULL;
  
                  while ((nvp = nvlist_next_nvpair(localprops, nvp)) != NULL) {
                          if (nvpair_type(nvp) == DATA_TYPE_BOOLEAN) {
                                  /* -x property */
                                  const char *name = nvpair_name(nvp);
                                  zfs_prop_t prop = zfs_name_to_prop(name);
                                  if (prop != ZPROP_USERPROP) {
                                          if (!zfs_prop_inheritable(prop))
                                                  continue;
                                  } else if (!zfs_prop_user(name))
                                          continue;
                                  fnvlist_add_boolean(xprops, name);
                          } else {
                                  /* -o property=value */
                                  fnvlist_add_nvpair(oprops, nvp);
                          }
                  }
  
                  local_delayprops = extract_delay_props(oprops);
                  (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_LOCAL,
                      oprops, *errors);
                  inherited_delayprops = extract_delay_props(xprops);
                  (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_INHERITED,
                      xprops, *errors);
  
                  nvlist_free(oprops);
                  nvlist_free(xprops);
          }
  
          error = dmu_recv_stream(&drc, &off);
  
          if (error == 0) {
                  zfsvfs_t *zfsvfs = NULL;
                  zvol_state_handle_t *zv = NULL;
  
                  if (getzfsvfs(tofs, &zfsvfs) == 0) {
                          /* online recv */
                          dsl_dataset_t *ds;
                          int end_err;
                          boolean_t stream_is_redacted = DMU_GET_FEATUREFLAGS(
                              begin_record->drr_u.drr_begin.
                              drr_versioninfo) & DMU_BACKUP_FEATURE_REDACTED;
  
                          ds = dmu_objset_ds(zfsvfs->z_os);
                          error = zfs_suspend_fs(zfsvfs);
                          /*
                           * If the suspend fails, then the recv_end will
                           * likely also fail, and clean up after itself.
                           */
                          end_err = dmu_recv_end(&drc, zfsvfs);
                          /*
                           * If the dataset was not redacted, but we received a
                           * redacted stream onto it, we need to unmount the
                           * dataset.  Otherwise, resume the filesystem.
                           */
                          if (error == 0 && !drc.drc_newfs &&
                              stream_is_redacted && !tofs_was_redacted) {
                                  error = zfs_end_fs(zfsvfs, ds);
                          } else if (error == 0) {
                                  error = zfs_resume_fs(zfsvfs, ds);
                          }
                          error = error ? error : end_err;
                          zfs_vfs_rele(zfsvfs);
                  } else if ((zv = zvol_suspend(tofs)) != NULL) {
                          error = dmu_recv_end(&drc, zvol_tag(zv));
                          zvol_resume(zv);
                  } else {
                          error = dmu_recv_end(&drc, NULL);
                  }
  
                  /* Set delayed properties now, after we're done receiving. */
                  if (recv_delayprops != NULL && error == 0) {
                          (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_RECEIVED,
                              recv_delayprops, *errors);
                  }
                  if (local_delayprops != NULL && error == 0) {
                          (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_LOCAL,
                              local_delayprops, *errors);
                  }
                  if (inherited_delayprops != NULL && error == 0) {
                          (void) zfs_set_prop_nvlist(tofs, ZPROP_SRC_INHERITED,
                              inherited_delayprops, *errors);
                  }
          }
  
          /*
           * 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.
           */
          if (recv_delayprops != NULL) {
                  ASSERT(nvlist_merge(recvprops, recv_delayprops, 0) == 0);
                  nvlist_free(recv_delayprops);
          }
          if (local_delayprops != NULL) {
                  ASSERT(nvlist_merge(localprops, local_delayprops, 0) == 0);
                  nvlist_free(local_delayprops);
          }
          if (inherited_delayprops != NULL) {
                  ASSERT(nvlist_merge(localprops, inherited_delayprops, 0) == 0);
                  nvlist_free(inherited_delayprops);
          }
          *read_bytes = off - noff;
  
  #ifdef  ZFS_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 && recvprops != NULL && !drc.drc_newfs) {
                  if (clear_received_props(tofs, recvprops, 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 (origrecvd == 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
                   * explicitly if we're restoring local properties cleared in the
                   * first new-style receive.
                   */
                  if (origrecvd != NULL &&
                      zfs_set_prop_nvlist(tofs, (first_recvd_props ?
                      ZPROP_SRC_LOCAL : ZPROP_SRC_RECEIVED),
                      origrecvd, NULL) != 0) {
                          /*
                           * We stashed the original properties but failed to
                           * restore them.
                           */
                          *errflags |= ZPROP_ERR_NORESTORE;
                  }
          }
          if (error != 0 && localprops != NULL && !drc.drc_newfs &&
              !first_recvd_props) {
                  nvlist_t *setprops;
                  nvlist_t *inheritprops;
                  nvpair_t *nvp;
  
                  if (origprops == NULL) {
                          /* We failed to stash the original properties. */
                          *errflags |= ZPROP_ERR_NORESTORE;
                          goto out;
                  }
  
                  /* Restore original props */
                  setprops = fnvlist_alloc();
                  inheritprops = fnvlist_alloc();
                  nvp = NULL;
                  while ((nvp = nvlist_next_nvpair(localprops, nvp)) != NULL) {
                          const char *name = nvpair_name(nvp);
                          const char *source;
                          nvlist_t *attrs;
  
                          if (!nvlist_exists(origprops, name)) {
                                  /*
                                   * Property was not present or was explicitly
                                   * inherited before the receive, restore this.
                                   */
                                  fnvlist_add_boolean(inheritprops, name);
                                  continue;
                          }
                          attrs = fnvlist_lookup_nvlist(origprops, name);
                          source = fnvlist_lookup_string(attrs, ZPROP_SOURCE);
  
                          /* Skip received properties */
                          if (strcmp(source, ZPROP_SOURCE_VAL_RECVD) == 0)
                                  continue;
  
                          if (strcmp(source, tofs) == 0) {
                                  /* Property was locally set */
                                  fnvlist_add_nvlist(setprops, name, attrs);
                          } else {
                                  /* Property was implicitly inherited */
                                  fnvlist_add_boolean(inheritprops, name);
                          }
                  }
  
                  if (zfs_set_prop_nvlist(tofs, ZPROP_SRC_LOCAL, setprops,
                      NULL) != 0)
                          *errflags |= ZPROP_ERR_NORESTORE;
                  if (zfs_set_prop_nvlist(tofs, ZPROP_SRC_INHERITED, inheritprops,
                      NULL) != 0)
                          *errflags |= ZPROP_ERR_NORESTORE;
  
                  nvlist_free(setprops);
                  nvlist_free(inheritprops);
          }
  out:
          zfs_file_put(input_fp);
          nvlist_free(origrecvd);
          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_nvlist_conf{_size}        nvlist of properties to exclude
   *                      (DATA_TYPE_BOOLEAN) and override (everything else)
   * 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
   *
   * outputs:
   * zc_cookie            number of bytes read
   * zc_obj               zprop_errflags_t
   * 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 *recvdprops = NULL;
          nvlist_t *localprops = 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, &recvdprops)) != 0)
                  return (error);
  
          if (zc->zc_nvlist_conf != 0 &&
              (error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
              zc->zc_iflags, &localprops)) != 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, recvdprops, localprops,
              NULL, zc->zc_guid, B_FALSE, B_FALSE, zc->zc_cookie, &begin_record,
              &zc->zc_cookie, &zc->zc_obj, &errors);
          nvlist_free(recvdprops);
          nvlist_free(localprops);
  
          /*
           * 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" -> received properties to set (nvlist)
   *     (optional) "localprops" -> override and exclude properties (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) "heal" -> use send stream to heal data corruption
   *     (optional) "resumable" -> resumable flag (value ignored)
   *     (optional) "cleanup_fd" -> unused
   *     (optional) "action_handle" -> unused
   *     (optional) "hidden_args" -> { "wkeydata" -> value }
   * }
   *
   * outnvl: {
   *     "read_bytes" -> number of bytes read
   *     "error_flags" -> zprop_errflags_t
   *     "errors" -> error for each unapplied received property (nvlist)
   * }
   */
  static const zfs_ioc_key_t zfs_keys_recv_new[] = {
          {"snapname",            DATA_TYPE_STRING,       0},
          {"props",               DATA_TYPE_NVLIST,       ZK_OPTIONAL},
          {"localprops",          DATA_TYPE_NVLIST,       ZK_OPTIONAL},
          {"origin",              DATA_TYPE_STRING,       ZK_OPTIONAL},
          {"begin_record",        DATA_TYPE_BYTE_ARRAY,   0},
          {"input_fd",            DATA_TYPE_INT32,        0},
          {"force",               DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"heal",                DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"resumable",           DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"cleanup_fd",          DATA_TYPE_INT32,        ZK_OPTIONAL},
          {"action_handle",       DATA_TYPE_UINT64,       ZK_OPTIONAL},
          {"hidden_args",         DATA_TYPE_NVLIST,       ZK_OPTIONAL},
  };
  
  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 *recvprops = NULL;
          nvlist_t *localprops = NULL;
          nvlist_t *hidden_args = NULL;
          char *snapname;
          char *origin = NULL;
          char *tosnap;
          char tofs[ZFS_MAX_DATASET_NAME_LEN];
          boolean_t force;
          boolean_t heal;
          boolean_t resumable;
          uint64_t read_bytes = 0;
          uint64_t errflags = 0;
          int input_fd = -1;
          int error;
  
          snapname = fnvlist_lookup_string(innvl, "snapname");
  
          if (dataset_namecheck(snapname, NULL, NULL) != 0 ||
              strchr(snapname, '@') == NULL ||
              strchr(snapname, '%'))
                  return (SET_ERROR(EINVAL));
  
          (void) strlcpy(tofs, snapname, sizeof (tofs));
          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));
  
          input_fd = fnvlist_lookup_int32(innvl, "input_fd");
  
          force = nvlist_exists(innvl, "force");
          heal = nvlist_exists(innvl, "heal");
          resumable = nvlist_exists(innvl, "resumable");
  
          /* we still use "props" here for backwards compatibility */
          error = nvlist_lookup_nvlist(innvl, "props", &recvprops);
          if (error && error != ENOENT)
                  return (error);
  
          error = nvlist_lookup_nvlist(innvl, "localprops", &localprops);
          if (error && error != ENOENT)
                  return (error);
  
          error = nvlist_lookup_nvlist(innvl, ZPOOL_HIDDEN_ARGS, &hidden_args);
          if (error && error != ENOENT)
                  return (error);
  
          error = zfs_ioc_recv_impl(tofs, tosnap, origin, recvprops, localprops,
              hidden_args, force, heal, resumable, input_fd, begin_record,
              &read_bytes, &errflags, &errors);
  
          fnvlist_add_uint64(outnvl, "read_bytes", read_bytes);
          fnvlist_add_uint64(outnvl, "error_flags", errflags);
          fnvlist_add_nvlist(outnvl, "errors", errors);
  
          nvlist_free(errors);
          nvlist_free(recvprops);
          nvlist_free(localprops);
  
          return (error);
  }
  
  typedef struct dump_bytes_io {
          zfs_file_t      *dbi_fp;
          caddr_t         dbi_buf;
          int             dbi_len;
          int             dbi_err;
  } dump_bytes_io_t;
  
  static void
  dump_bytes_cb(void *arg)
  {
          dump_bytes_io_t *dbi = (dump_bytes_io_t *)arg;
          zfs_file_t *fp;
          caddr_t buf;
  
          fp = dbi->dbi_fp;
          buf = dbi->dbi_buf;
  
          dbi->dbi_err = zfs_file_write(fp, buf, dbi->dbi_len, NULL);
  }
  
  static int
  dump_bytes(objset_t *os, void *buf, int len, void *arg)
  {
          dump_bytes_io_t dbi;
  
          dbi.dbi_fp = arg;
          dbi.dbi_buf = buf;
          dbi.dbi_len = len;
  
  #if defined(HAVE_LARGE_STACKS)
          dump_bytes_cb(&dbi);
  #else
          /*
           * The vn_rdwr() call is performed in a taskq to ensure that there is
           * always enough stack space to write safely to the target filesystem.
           * The ZIO_TYPE_FREE threads are used because there can be a lot of
           * them and they are used in vdev_file.c for a similar purpose.
           */
          spa_taskq_dispatch_sync(dmu_objset_spa(os), ZIO_TYPE_FREE,
              ZIO_TASKQ_ISSUE, dump_bytes_cb, &dbi, TQ_SLEEP);
  #endif /* HAVE_LARGE_STACKS */
  
          return (dbi.dbi_err);
  }
  
  /*
   * 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
   *
   * NOTE: This is no longer the preferred interface, any new functionality
   *        should be added to zfs_ioc_send_new() instead.
   */
  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);
          boolean_t rawok = (zc->zc_flags & 0x8);
          boolean_t savedok = (zc->zc_flags & 0x10);
  
          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_fast(tosnap, fromsnap, NULL,
                      compressok || rawok, savedok, &zc->zc_objset_type);
  
                  if (fromsnap != NULL)
                          dsl_dataset_rele(fromsnap, FTAG);
                  dsl_dataset_rele(tosnap, FTAG);
                  dsl_pool_rele(dp, FTAG);
          } else {
                  zfs_file_t *fp;
                  dmu_send_outparams_t out = {0};
  
                  if ((fp = zfs_file_get(zc->zc_cookie)) == NULL)
                          return (SET_ERROR(EBADF));
  
                  off = zfs_file_off(fp);
                  out.dso_outfunc = dump_bytes;
                  out.dso_arg = fp;
                  out.dso_dryrun = B_FALSE;
                  error = dmu_send_obj(zc->zc_name, zc->zc_sendobj,
                      zc->zc_fromobj, embedok, large_block_ok, compressok,
                      rawok, savedok, zc->zc_cookie, &off, &out);
  
                  zfs_file_put(fp);
          }
          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
   * zc_objset_type       logical size of data traversed by send thus far
   */
  static int
  zfs_ioc_send_progress(zfs_cmd_t *zc)
  {
          dsl_pool_t *dp;
          dsl_dataset_t *ds;
          dmu_sendstatus_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->dss_outfd == zc->zc_cookie &&
                      zfs_proc_is_caller(dsp->dss_proc))
                          break;
          }
  
          if (dsp != NULL) {
                  zc->zc_cookie = atomic_cas_64((volatile uint64_t *)dsp->dss_off,
                      0, 0);
                  /* This is the closest thing we have to atomic_read_64. */
                  zc->zc_objset_type = atomic_cas_64(&dsp->dss_blocks, 0, 0);
          } 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;
  
          if ((error = spa_open(zc->zc_name, &spa, FTAG)) != 0)
                  return (error);
  
          error = spa_get_errlog(spa, (void *)(uintptr_t)zc->zc_nvlist_dst,
              &zc->zc_nvlist_dst_size);
  
          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);
  
          /*
           * If multihost is enabled, resuming I/O is unsafe as another
           * host may have imported the pool.
           */
          if (spa_multihost(spa) && spa_suspended(spa))
                  return (SET_ERROR(EINVAL));
  
          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) {
                          error = SET_ERROR(ENODEV);
                          (void) spa_vdev_state_exit(spa, NULL, error);
                          spa_close(spa, FTAG);
                          return (error);
                  }
          }
  
          vdev_clear(spa, vd);
  
          (void) spa_vdev_state_exit(spa, spa_suspended(spa) ?
              NULL : spa->spa_root_vdev, 0);
  
          /*
           * Resume any suspended I/Os.
           */
          if (zio_resume(spa) != 0)
                  error = SET_ERROR(EIO);
  
          spa_close(spa, FTAG);
  
          return (error);
  }
  
  /*
   * Reopen all the vdevs associated with the pool.
   *
   * innvl: {
   *  "scrub_restart" -> when true and scrub is running, allow to restart
   *              scrub as the side effect of the reopen (boolean).
   * }
   *
   * outnvl is unused
   */
  static const zfs_ioc_key_t zfs_keys_pool_reopen[] = {
          {"scrub_restart",       DATA_TYPE_BOOLEAN_VALUE,        ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_pool_reopen(const char *pool, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) outnvl;
          spa_t *spa;
          int error;
          boolean_t rc, scrub_restart = B_TRUE;
  
          if (innvl) {
                  error = nvlist_lookup_boolean_value(innvl,
                      "scrub_restart", &rc);
                  if (error == 0)
                          scrub_restart = rc;
          }
  
          error = spa_open(pool, &spa, FTAG);
          if (error != 0)
                  return (error);
  
          spa_vdev_state_enter(spa, SCL_NONE);
  
          /*
           * If the scrub_restart flag is B_FALSE and a scrub is already
           * in progress then set spa_scrub_reopen flag to B_TRUE so that
           * we don't restart the scrub as a side effect of the reopen.
           * Otherwise, let vdev_open() decided if a resilver is required.
           */
  
          spa->spa_scrub_reopen = (!scrub_restart &&
              dsl_scan_scrubbing(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
   *
   * outputs:
   * zc_string    name of conflicting snapshot, if there is one
   */
  static int
  zfs_ioc_promote(zfs_cmd_t *zc)
  {
          dsl_pool_t *dp;
          dsl_dataset_t *ds, *ods;
          char origin[ZFS_MAX_DATASET_NAME_LEN];
          char *cp;
          int error;
  
          zc->zc_name[sizeof (zc->zc_name) - 1] = '\0';
          if (dataset_namecheck(zc->zc_name, NULL, NULL) != 0 ||
              strchr(zc->zc_name, '%'))
                  return (SET_ERROR(EINVAL));
  
          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);
          }
  
          if (!dsl_dir_is_clone(ds->ds_dir)) {
                  dsl_dataset_rele(ds, FTAG);
                  dsl_pool_rele(dp, FTAG);
                  return (SET_ERROR(EINVAL));
          }
  
          error = dsl_dataset_hold_obj(dp,
              dsl_dir_phys(ds->ds_dir)->dd_origin_obj, FTAG, &ods);
          if (error != 0) {
                  dsl_dataset_rele(ds, FTAG);
                  dsl_pool_rele(dp, FTAG);
                  return (error);
          }
  
          dsl_dataset_name(ods, origin);
          dsl_dataset_rele(ods, FTAG);
          dsl_dataset_rele(ds, FTAG);
          dsl_pool_rele(dp, FTAG);
  
          /*
           * We don't need to unmount *all* the origin fs's snapshots, but
           * it's easier.
           */
          cp = strchr(origin, '@');
          if (cp)
                  *cp = '\0';
          (void) dmu_objset_find(origin,
              zfs_unmount_snap_cb, NULL, DS_FIND_SNAPSHOTS);
          return (dsl_dataset_promote(zc->zc_name, zc->zc_string));
  }
  
  /*
   * Retrieve a single {user|group|project}{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)
  {
          zfsvfs_t *zfsvfs;
          int error;
  
          if (zc->zc_objset_type >= ZFS_NUM_USERQUOTA_PROPS)
                  return (SET_ERROR(EINVAL));
  
          error = zfsvfs_hold(zc->zc_name, FTAG, &zfsvfs, B_FALSE);
          if (error != 0)
                  return (error);
  
          error = zfs_userspace_one(zfsvfs,
              zc->zc_objset_type, zc->zc_value, zc->zc_guid, &zc->zc_cookie);
          zfsvfs_rele(zfsvfs, 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)
  {
          zfsvfs_t *zfsvfs;
          int bufsize = zc->zc_nvlist_dst_size;
  
          if (bufsize <= 0)
                  return (SET_ERROR(ENOMEM));
  
          int error = zfsvfs_hold(zc->zc_name, FTAG, &zfsvfs, B_FALSE);
          if (error != 0)
                  return (error);
  
          void *buf = vmem_alloc(bufsize, KM_SLEEP);
  
          error = zfs_userspace_many(zfsvfs, 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);
          zfsvfs_rele(zfsvfs, FTAG);
  
          return (error);
  }
  
  /*
   * inputs:
   * zc_name              name of filesystem
   *
   * outputs:
   * none
   */
  static int
  zfs_ioc_userspace_upgrade(zfs_cmd_t *zc)
  {
          int error = 0;
          zfsvfs_t *zfsvfs;
  
          if (getzfsvfs(zc->zc_name, &zfsvfs) == 0) {
                  if (!dmu_objset_userused_enabled(zfsvfs->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.
                           */
                          dsl_dataset_t *ds, *newds;
  
                          ds = dmu_objset_ds(zfsvfs->z_os);
                          error = zfs_suspend_fs(zfsvfs);
                          if (error == 0) {
                                  dmu_objset_refresh_ownership(ds, &newds,
                                      B_TRUE, zfsvfs);
                                  error = zfs_resume_fs(zfsvfs, newds);
                          }
                  }
                  if (error == 0) {
                          mutex_enter(&zfsvfs->z_os->os_upgrade_lock);
                          if (zfsvfs->z_os->os_upgrade_id == 0) {
                                  /* clear potential error code and retry */
                                  zfsvfs->z_os->os_upgrade_status = 0;
                                  mutex_exit(&zfsvfs->z_os->os_upgrade_lock);
  
                                  dsl_pool_config_enter(
                                      dmu_objset_pool(zfsvfs->z_os), FTAG);
                                  dmu_objset_userspace_upgrade(zfsvfs->z_os);
                                  dsl_pool_config_exit(
                                      dmu_objset_pool(zfsvfs->z_os), FTAG);
                          } else {
                                  mutex_exit(&zfsvfs->z_os->os_upgrade_lock);
                          }
  
                          taskq_wait_id(zfsvfs->z_os->os_spa->spa_upgrade_taskq,
                              zfsvfs->z_os->os_upgrade_id);
                          error = zfsvfs->z_os->os_upgrade_status;
                  }
                  zfs_vfs_rele(zfsvfs);
          } else {
                  objset_t *os;
  
                  /* XXX kind of reading contents without owning */
                  error = dmu_objset_hold_flags(zc->zc_name, B_TRUE, FTAG, &os);
                  if (error != 0)
                          return (error);
  
                  mutex_enter(&os->os_upgrade_lock);
                  if (os->os_upgrade_id == 0) {
                          /* clear potential error code and retry */
                          os->os_upgrade_status = 0;
                          mutex_exit(&os->os_upgrade_lock);
  
                          dmu_objset_userspace_upgrade(os);
                  } else {
                          mutex_exit(&os->os_upgrade_lock);
                  }
  
                  dsl_pool_rele(dmu_objset_pool(os), FTAG);
  
                  taskq_wait_id(os->os_spa->spa_upgrade_taskq, os->os_upgrade_id);
                  error = os->os_upgrade_status;
  
                  dsl_dataset_rele_flags(dmu_objset_ds(os), DS_HOLD_FLAG_DECRYPT,
                      FTAG);
          }
          return (error);
  }
  
  /*
   * inputs:
   * zc_name              name of filesystem
   *
   * outputs:
   * none
   */
  static int
  zfs_ioc_id_quota_upgrade(zfs_cmd_t *zc)
  {
          objset_t *os;
          int error;
  
          error = dmu_objset_hold_flags(zc->zc_name, B_TRUE, FTAG, &os);
          if (error != 0)
                  return (error);
  
          if (dmu_objset_userobjspace_upgradable(os) ||
              dmu_objset_projectquota_upgradable(os)) {
                  mutex_enter(&os->os_upgrade_lock);
                  if (os->os_upgrade_id == 0) {
                          /* clear potential error code and retry */
                          os->os_upgrade_status = 0;
                          mutex_exit(&os->os_upgrade_lock);
  
                          dmu_objset_id_quota_upgrade(os);
                  } else {
                          mutex_exit(&os->os_upgrade_lock);
                  }
  
                  dsl_pool_rele(dmu_objset_pool(os), FTAG);
  
                  taskq_wait_id(os->os_spa->spa_upgrade_taskq, os->os_upgrade_id);
                  error = os->os_upgrade_status;
          } else {
                  dsl_pool_rele(dmu_objset_pool(os), FTAG);
          }
  
          dsl_dataset_rele_flags(dmu_objset_ds(os), DS_HOLD_FLAG_DECRYPT, FTAG);
  
          return (error);
  }
  
  static int
  zfs_ioc_share(zfs_cmd_t *zc)
  {
          return (SET_ERROR(ENOSYS));
  }
  
  /*
   * 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;
          minor_t minor;
  
          zfs_file_t *fp = zfs_onexit_fd_hold(zc->zc_cleanup_fd, &minor);
          if (fp == NULL)
                  return (SET_ERROR(EBADF));
  
          snap_name = kmem_asprintf("%s-%016llx", zc->zc_value,
              (u_longlong_t)ddi_get_lbolt64());
          hold_name = kmem_asprintf("%%%s", zc->zc_value);
  
          int error = dsl_dataset_snapshot_tmp(zc->zc_name, snap_name, minor,
              hold_name);
          if (error == 0)
                  (void) strlcpy(zc->zc_value, snap_name,
                      sizeof (zc->zc_value));
          kmem_strfree(snap_name);
          kmem_strfree(hold_name);
          zfs_onexit_fd_rele(fp);
          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)
  {
          zfs_file_t *fp;
          offset_t off;
          int error;
  
          if ((fp = zfs_file_get(zc->zc_cookie)) == NULL)
                  return (SET_ERROR(EBADF));
  
          off = zfs_file_off(fp);
          error = dmu_diff(zc->zc_name, zc->zc_value, fp, &off);
  
          zfs_file_put(fp);
  
          return (error);
  }
  
  static int
  zfs_ioc_smb_acl(zfs_cmd_t *zc)
  {
          return (SET_ERROR(ENOTSUP));
  }
  
  /*
   * innvl: {
   *     "holds" -> { snapname -> holdname (string), ... }
   *     (optional) "cleanup_fd" -> fd (int32)
   * }
   *
   * outnvl: {
   *     snapname -> error value (int32)
   *     ...
   * }
   */
  static const zfs_ioc_key_t zfs_keys_hold[] = {
          {"holds",               DATA_TYPE_NVLIST,       0},
          {"cleanup_fd",          DATA_TYPE_INT32,        ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_hold(const char *pool, nvlist_t *args, nvlist_t *errlist)
  {
          (void) pool;
          nvpair_t *pair;
          nvlist_t *holds;
          int cleanup_fd = -1;
          int error;
          minor_t minor = 0;
          zfs_file_t *fp = NULL;
  
          holds = fnvlist_lookup_nvlist(args, "holds");
  
          /* 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) {
                  fp = zfs_onexit_fd_hold(cleanup_fd, &minor);
                  if (fp == NULL)
                          return (SET_ERROR(EBADF));
          }
  
          error = dsl_dataset_user_hold(holds, minor, errlist);
          if (fp != NULL) {
                  ASSERT3U(minor, !=, 0);
                  zfs_onexit_fd_rele(fp);
          }
          return (SET_ERROR(error));
  }
  
  /*
   * innvl is not used.
   *
   * outnvl: {
   *    holdname -> time added (uint64 seconds since epoch)
   *    ...
   * }
   */
  static const zfs_ioc_key_t zfs_keys_get_holds[] = {
          /* no nvl keys */
  };
  
  static int
  zfs_ioc_get_holds(const char *snapname, nvlist_t *args, nvlist_t *outnvl)
  {
          (void) args;
          return (dsl_dataset_get_holds(snapname, outnvl));
  }
  
  /*
   * innvl: {
   *     snapname -> { holdname, ... }
   *     ...
   * }
   *
   * outnvl: {
   *     snapname -> error value (int32)
   *     ...
   * }
   */
  static const zfs_ioc_key_t zfs_keys_release[] = {
          {"<snapname>...",       DATA_TYPE_NVLIST,       ZK_WILDCARDLIST},
  };
  
  static int
  zfs_ioc_release(const char *pool, nvlist_t *holds, nvlist_t *errlist)
  {
          (void) pool;
          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;
  
          zfs_file_t *fp = zfs_zevent_fd_hold(zc->zc_cleanup_fd, &minor, &ze);
          if (fp == NULL)
                  return (SET_ERROR(EBADF));
  
          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(fp);
  
          return (error);
  }
  
  /*
   * outputs:
   * zc_cookie            cleared events count
   */
  static int
  zfs_ioc_events_clear(zfs_cmd_t *zc)
  {
          uint_t 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;
  
          zfs_file_t *fp = zfs_zevent_fd_hold(zc->zc_cleanup_fd, &minor, &ze);
          if (fp == NULL)
                  return (SET_ERROR(EBADF));
  
          error = zfs_zevent_seek(ze, zc->zc_guid);
          zfs_zevent_fd_rele(fp);
  
          return (error);
  }
  
  /*
   * inputs:
   * zc_name              name of later filesystem or snapshot
   * zc_value             full name of old snapshot or bookmark
   *
   * 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;
  
          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);
          }
          if (strchr(zc->zc_value, '#') != NULL) {
                  zfs_bookmark_phys_t bmp;
                  error = dsl_bookmark_lookup(dp, zc->zc_value,
                      new, &bmp);
                  if (error == 0) {
                          error = dsl_dataset_space_written_bookmark(&bmp, new,
                              &zc->zc_cookie,
                              &zc->zc_objset_type, &zc->zc_perm_action);
                  }
          } else {
                  dsl_dataset_t *old;
                  error = dsl_dataset_hold(dp, zc->zc_value, FTAG, &old);
  
                  if (error == 0) {
                          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 const zfs_ioc_key_t zfs_keys_space_snaps[] = {
          {"firstsnap",   DATA_TYPE_STRING,       0},
  };
  
  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;
  
          firstsnap = fnvlist_lookup_string(innvl, "firstsnap");
  
          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) "rawok" -> (value ignored)
   *         presence indicates raw encrypted records should be used.
   *     (optional) "savedok" -> (value ignored)
   *         presence indicates we should send a partially received snapshot
   *     (optional) "resume_object" and "resume_offset" -> (uint64)
   *         if present, resume send stream from specified object and offset.
   *     (optional) "redactbook" -> (string)
   *         if present, use this bookmark's redaction list to generate a redacted
   *         send stream
   * }
   *
   * outnvl is unused
   */
  static const zfs_ioc_key_t zfs_keys_send_new[] = {
          {"fd",                  DATA_TYPE_INT32,        0},
          {"fromsnap",            DATA_TYPE_STRING,       ZK_OPTIONAL},
          {"largeblockok",        DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"embedok",             DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"compressok",          DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"rawok",               DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"savedok",             DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"resume_object",       DATA_TYPE_UINT64,       ZK_OPTIONAL},
          {"resume_offset",       DATA_TYPE_UINT64,       ZK_OPTIONAL},
          {"redactbook",          DATA_TYPE_STRING,       ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_send_new(const char *snapname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) outnvl;
          int error;
          offset_t off;
          char *fromname = NULL;
          int fd;
          zfs_file_t *fp;
          boolean_t largeblockok;
          boolean_t embedok;
          boolean_t compressok;
          boolean_t rawok;
          boolean_t savedok;
          uint64_t resumeobj = 0;
          uint64_t resumeoff = 0;
          char *redactbook = NULL;
  
          fd = fnvlist_lookup_int32(innvl, "fd");
  
          (void) nvlist_lookup_string(innvl, "fromsnap", &fromname);
  
          largeblockok = nvlist_exists(innvl, "largeblockok");
          embedok = nvlist_exists(innvl, "embedok");
          compressok = nvlist_exists(innvl, "compressok");
          rawok = nvlist_exists(innvl, "rawok");
          savedok = nvlist_exists(innvl, "savedok");
  
          (void) nvlist_lookup_uint64(innvl, "resume_object", &resumeobj);
          (void) nvlist_lookup_uint64(innvl, "resume_offset", &resumeoff);
  
          (void) nvlist_lookup_string(innvl, "redactbook", &redactbook);
  
          if ((fp = zfs_file_get(fd)) == NULL)
                  return (SET_ERROR(EBADF));
  
          off = zfs_file_off(fp);
  
          dmu_send_outparams_t out = {0};
          out.dso_outfunc = dump_bytes;
          out.dso_arg = fp;
          out.dso_dryrun = B_FALSE;
          error = dmu_send(snapname, fromname, embedok, largeblockok,
              compressok, rawok, savedok, resumeobj, resumeoff,
              redactbook, fd, &off, &out);
  
          zfs_file_put(fp);
          return (error);
  }
  
  static int
  send_space_sum(objset_t *os, void *buf, int len, void *arg)
  {
          (void) os, (void) buf;
          uint64_t *size = arg;
  
          *size += len;
          return (0);
  }
  
  /*
   * 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
   *     (optional) "rawok" -> (value ignored)
   *         presence indicates raw encrypted records should be used.
   *     (optional) "resume_object" and "resume_offset" -> (uint64)
   *         if present, resume send stream from specified object and offset.
   *     (optional) "fd" -> file descriptor to use as a cookie for progress
   *         tracking (int32)
   * }
   *
   * outnvl: {
   *     "space" -> bytes of space (uint64)
   * }
   */
  static const zfs_ioc_key_t zfs_keys_send_space[] = {
          {"from",                DATA_TYPE_STRING,       ZK_OPTIONAL},
          {"fromsnap",            DATA_TYPE_STRING,       ZK_OPTIONAL},
          {"largeblockok",        DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"embedok",             DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"compressok",          DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"rawok",               DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
          {"fd",                  DATA_TYPE_INT32,        ZK_OPTIONAL},
          {"redactbook",          DATA_TYPE_STRING,       ZK_OPTIONAL},
          {"resume_object",       DATA_TYPE_UINT64,       ZK_OPTIONAL},
          {"resume_offset",       DATA_TYPE_UINT64,       ZK_OPTIONAL},
          {"bytes",               DATA_TYPE_UINT64,       ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_send_space(const char *snapname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          dsl_pool_t *dp;
          dsl_dataset_t *tosnap;
          dsl_dataset_t *fromsnap = NULL;
          int error;
          char *fromname = NULL;
          char *redactlist_book = NULL;
          boolean_t largeblockok;
          boolean_t embedok;
          boolean_t compressok;
          boolean_t rawok;
          boolean_t savedok;
          uint64_t space = 0;
          boolean_t full_estimate = B_FALSE;
          uint64_t resumeobj = 0;
          uint64_t resumeoff = 0;
          uint64_t resume_bytes = 0;
          int32_t fd = -1;
          zfs_bookmark_phys_t zbm = {0};
  
          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);
          }
          (void) nvlist_lookup_int32(innvl, "fd", &fd);
  
          largeblockok = nvlist_exists(innvl, "largeblockok");
          embedok = nvlist_exists(innvl, "embedok");
          compressok = nvlist_exists(innvl, "compressok");
          rawok = nvlist_exists(innvl, "rawok");
          savedok = nvlist_exists(innvl, "savedok");
          boolean_t from = (nvlist_lookup_string(innvl, "from", &fromname) == 0);
          boolean_t altbook = (nvlist_lookup_string(innvl, "redactbook",
              &redactlist_book) == 0);
  
          (void) nvlist_lookup_uint64(innvl, "resume_object", &resumeobj);
          (void) nvlist_lookup_uint64(innvl, "resume_offset", &resumeoff);
          (void) nvlist_lookup_uint64(innvl, "bytes", &resume_bytes);
  
          if (altbook) {
                  full_estimate = B_TRUE;
          } else if (from) {
                  if (strchr(fromname, '#')) {
                          error = dsl_bookmark_lookup(dp, fromname, tosnap, &zbm);
  
                          /*
                           * dsl_bookmark_lookup() will fail with EXDEV if
                           * the from-bookmark and tosnap are at the same txg.
                           * However, it's valid to do a send (and therefore,
                           * a send estimate) from and to the same time point,
                           * if the bookmark is redacted (the incremental send
                           * can change what's redacted on the target).  In
                           * this case, dsl_bookmark_lookup() fills in zbm
                           * but returns EXDEV.  Ignore this error.
                           */
                          if (error == EXDEV && zbm.zbm_redaction_obj != 0 &&
                              zbm.zbm_guid ==
                              dsl_dataset_phys(tosnap)->ds_guid)
                                  error = 0;
  
                          if (error != 0) {
                                  dsl_dataset_rele(tosnap, FTAG);
                                  dsl_pool_rele(dp, FTAG);
                                  return (error);
                          }
                          if (zbm.zbm_redaction_obj != 0 || !(zbm.zbm_flags &
                              ZBM_FLAG_HAS_FBN)) {
                                  full_estimate = B_TRUE;
                          }
                  } else if (strchr(fromname, '@')) {
                          error = dsl_dataset_hold(dp, fromname, FTAG, &fromsnap);
                          if (error != 0) {
                                  dsl_dataset_rele(tosnap, FTAG);
                                  dsl_pool_rele(dp, FTAG);
                                  return (error);
                          }
  
                          if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
                                  full_estimate = B_TRUE;
                                  dsl_dataset_rele(fromsnap, FTAG);
                          }
                  } else {
                          /*
                           * from is not properly formatted as a snapshot or
                           * bookmark
                           */
                          dsl_dataset_rele(tosnap, FTAG);
                          dsl_pool_rele(dp, FTAG);
                          return (SET_ERROR(EINVAL));
                  }
          }
  
          if (full_estimate) {
                  dmu_send_outparams_t out = {0};
                  offset_t off = 0;
                  out.dso_outfunc = send_space_sum;
                  out.dso_arg = &space;
                  out.dso_dryrun = B_TRUE;
                  /*
                   * We have to release these holds so dmu_send can take them.  It
                   * will do all the error checking we need.
                   */
                  dsl_dataset_rele(tosnap, FTAG);
                  dsl_pool_rele(dp, FTAG);
                  error = dmu_send(snapname, fromname, embedok, largeblockok,
                      compressok, rawok, savedok, resumeobj, resumeoff,
                      redactlist_book, fd, &off, &out);
          } else {
                  error = dmu_send_estimate_fast(tosnap, fromsnap,
                      (from && strchr(fromname, '#') != NULL ? &zbm : NULL),
                      compressok || rawok, savedok, &space);
                  space -= resume_bytes;
                  if (fromsnap != NULL)
                          dsl_dataset_rele(fromsnap, FTAG);
                  dsl_dataset_rele(tosnap, FTAG);
                  dsl_pool_rele(dp, FTAG);
          }
  
          fnvlist_add_uint64(outnvl, "space", space);
  
          return (error);
  }
  
  /*
   * Sync the currently open TXG to disk for the specified pool.
   * This is somewhat similar to 'zfs_sync()'.
   * For cases that do not result in error this ioctl will wait for
   * the currently open TXG to commit before returning back to the caller.
   *
   * innvl: {
   *  "force" -> when true, force uberblock update even if there is no dirty data.
   *             In addition this will cause the vdev configuration to be written
   *             out including updating the zpool cache file. (boolean_t)
   * }
   *
   * onvl is unused
   */
  static const zfs_ioc_key_t zfs_keys_pool_sync[] = {
          {"force",       DATA_TYPE_BOOLEAN_VALUE,        0},
  };
  
  static int
  zfs_ioc_pool_sync(const char *pool, nvlist_t *innvl, nvlist_t *onvl)
  {
          (void) onvl;
          int err;
          boolean_t rc, force = B_FALSE;
          spa_t *spa;
  
          if ((err = spa_open(pool, &spa, FTAG)) != 0)
                  return (err);
  
          if (innvl) {
                  err = nvlist_lookup_boolean_value(innvl, "force", &rc);
                  if (err == 0)
                          force = rc;
          }
  
          if (force) {
                  spa_config_enter(spa, SCL_CONFIG, FTAG, RW_WRITER);
                  vdev_config_dirty(spa->spa_root_vdev);
                  spa_config_exit(spa, SCL_CONFIG, FTAG);
          }
          txg_wait_synced(spa_get_dsl(spa), 0);
  
          spa_close(spa, FTAG);
  
          return (0);
  }
  
  /*
   * Load a user's wrapping key into the kernel.
   * innvl: {
   *     "hidden_args" -> { "wkeydata" -> value }
   *         raw uint8_t array of encryption wrapping key data (32 bytes)
   *     (optional) "noop" -> (value ignored)
   *         presence indicated key should only be verified, not loaded
   * }
   */
  static const zfs_ioc_key_t zfs_keys_load_key[] = {
          {"hidden_args", DATA_TYPE_NVLIST,       0},
          {"noop",        DATA_TYPE_BOOLEAN,      ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_load_key(const char *dsname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) outnvl;
          int ret;
          dsl_crypto_params_t *dcp = NULL;
          nvlist_t *hidden_args;
          boolean_t noop = nvlist_exists(innvl, "noop");
  
          if (strchr(dsname, '@') != NULL || strchr(dsname, '%') != NULL) {
                  ret = SET_ERROR(EINVAL);
                  goto error;
          }
  
          hidden_args = fnvlist_lookup_nvlist(innvl, ZPOOL_HIDDEN_ARGS);
  
          ret = dsl_crypto_params_create_nvlist(DCP_CMD_NONE, NULL,
              hidden_args, &dcp);
          if (ret != 0)
                  goto error;
  
          ret = spa_keystore_load_wkey(dsname, dcp, noop);
          if (ret != 0)
                  goto error;
  
          dsl_crypto_params_free(dcp, noop);
  
          return (0);
  
  error:
          dsl_crypto_params_free(dcp, B_TRUE);
          return (ret);
  }
  
  /*
   * Unload a user's wrapping key from the kernel.
   * Both innvl and outnvl are unused.
   */
  static const zfs_ioc_key_t zfs_keys_unload_key[] = {
          /* no nvl keys */
  };
  
  static int
  zfs_ioc_unload_key(const char *dsname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) innvl, (void) outnvl;
          int ret = 0;
  
          if (strchr(dsname, '@') != NULL || strchr(dsname, '%') != NULL) {
                  ret = (SET_ERROR(EINVAL));
                  goto out;
          }
  
          ret = spa_keystore_unload_wkey(dsname);
          if (ret != 0)
                  goto out;
  
  out:
          return (ret);
  }
  
  /*
   * Changes a user's wrapping key used to decrypt a dataset. The keyformat,
   * keylocation, pbkdf2salt, and pbkdf2iters properties can also be specified
   * here to change how the key is derived in userspace.
   *
   * innvl: {
   *    "hidden_args" (optional) -> { "wkeydata" -> value }
   *         raw uint8_t array of new encryption wrapping key data (32 bytes)
   *    "props" (optional) -> { prop -> value }
   * }
   *
   * outnvl is unused
   */
  static const zfs_ioc_key_t zfs_keys_change_key[] = {
          {"crypt_cmd",   DATA_TYPE_UINT64,       ZK_OPTIONAL},
          {"hidden_args", DATA_TYPE_NVLIST,       ZK_OPTIONAL},
          {"props",       DATA_TYPE_NVLIST,       ZK_OPTIONAL},
  };
  
  static int
  zfs_ioc_change_key(const char *dsname, nvlist_t *innvl, nvlist_t *outnvl)
  {
          (void) outnvl;
          int ret;
          uint64_t cmd = DCP_CMD_NONE;
          dsl_crypto_params_t *dcp = NULL;
          nvlist_t *args = NULL, *hidden_args = NULL;
  
          if (strchr(dsname, '@') != NULL || strchr(dsname, '%') != NULL) {
                  ret = (SET_ERROR(EINVAL));
                  goto error;
          }
  
          (void) nvlist_lookup_uint64(innvl, "crypt_cmd", &cmd);
          (void) nvlist_lookup_nvlist(innvl, "props", &args);
          (void) nvlist_lookup_nvlist(innvl, ZPOOL_HIDDEN_ARGS, &hidden_args);
  
          ret = dsl_crypto_params_create_nvlist(cmd, args, hidden_args, &dcp);
          if (ret != 0)
                  goto error;
  
          ret = spa_keystore_change_key(dsname, dcp);
          if (ret != 0)
                  goto error;
  
          dsl_crypto_params_free(dcp, B_FALSE);
  
          return (0);
  
  error:
          dsl_crypto_params_free(dcp, B_TRUE);
          return (ret);
  }
  
  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.
   */
  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, const zfs_ioc_key_t *nvl_keys, size_t num_keys)
  {
          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;
          vec->zvec_nvl_keys = nvl_keys;
          vec->zvec_nvl_key_count = num_keys;
  }
  
  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);
  }
  
  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_keys_snapshot, ARRAY_SIZE(zfs_keys_snapshot));
  
          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_keys_log_history, ARRAY_SIZE(zfs_keys_log_history));
  
          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_keys_space_snaps, ARRAY_SIZE(zfs_keys_space_snaps));
  
          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_keys_send_new, ARRAY_SIZE(zfs_keys_send_new));
  
          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_keys_send_space, ARRAY_SIZE(zfs_keys_send_space));
  
          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_keys_create, ARRAY_SIZE(zfs_keys_create));
  
          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_keys_clone, ARRAY_SIZE(zfs_keys_clone));
  
          zfs_ioctl_register("remap", ZFS_IOC_REMAP,
              zfs_ioc_remap, zfs_secpolicy_none, DATASET_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_TRUE,
              zfs_keys_remap, ARRAY_SIZE(zfs_keys_remap));
  
          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_keys_destroy_snaps, ARRAY_SIZE(zfs_keys_destroy_snaps));
  
          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_keys_hold, ARRAY_SIZE(zfs_keys_hold));
          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_keys_release, ARRAY_SIZE(zfs_keys_release));
  
          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_keys_get_holds, ARRAY_SIZE(zfs_keys_get_holds));
  
          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_keys_rollback, ARRAY_SIZE(zfs_keys_rollback));
  
          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_keys_bookmark, ARRAY_SIZE(zfs_keys_bookmark));
  
          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_keys_get_bookmarks, ARRAY_SIZE(zfs_keys_get_bookmarks));
  
          zfs_ioctl_register("get_bookmark_props", ZFS_IOC_GET_BOOKMARK_PROPS,
              zfs_ioc_get_bookmark_props, zfs_secpolicy_read, ENTITY_NAME,
              POOL_CHECK_SUSPENDED, B_FALSE, B_FALSE, zfs_keys_get_bookmark_props,
              ARRAY_SIZE(zfs_keys_get_bookmark_props));
  
          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_keys_destroy_bookmarks,
              ARRAY_SIZE(zfs_keys_destroy_bookmarks));
  
          zfs_ioctl_register("receive", ZFS_IOC_RECV_NEW,
              zfs_ioc_recv_new, zfs_secpolicy_recv, DATASET_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE,
              zfs_keys_recv_new, ARRAY_SIZE(zfs_keys_recv_new));
          zfs_ioctl_register("load-key", ZFS_IOC_LOAD_KEY,
              zfs_ioc_load_key, zfs_secpolicy_load_key,
              DATASET_NAME, POOL_CHECK_SUSPENDED, B_TRUE, B_TRUE,
              zfs_keys_load_key, ARRAY_SIZE(zfs_keys_load_key));
          zfs_ioctl_register("unload-key", ZFS_IOC_UNLOAD_KEY,
              zfs_ioc_unload_key, zfs_secpolicy_load_key,
              DATASET_NAME, POOL_CHECK_SUSPENDED, B_TRUE, B_TRUE,
              zfs_keys_unload_key, ARRAY_SIZE(zfs_keys_unload_key));
          zfs_ioctl_register("change-key", ZFS_IOC_CHANGE_KEY,
              zfs_ioc_change_key, zfs_secpolicy_change_key,
              DATASET_NAME, POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY,
              B_TRUE, B_TRUE, zfs_keys_change_key,
              ARRAY_SIZE(zfs_keys_change_key));
  
          zfs_ioctl_register("sync", ZFS_IOC_POOL_SYNC,
              zfs_ioc_pool_sync, zfs_secpolicy_none, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_FALSE,
              zfs_keys_pool_sync, ARRAY_SIZE(zfs_keys_pool_sync));
          zfs_ioctl_register("reopen", ZFS_IOC_POOL_REOPEN, zfs_ioc_pool_reopen,
              zfs_secpolicy_config, POOL_NAME, POOL_CHECK_SUSPENDED, B_TRUE,
              B_TRUE, zfs_keys_pool_reopen, ARRAY_SIZE(zfs_keys_pool_reopen));
  
          zfs_ioctl_register("channel_program", ZFS_IOC_CHANNEL_PROGRAM,
              zfs_ioc_channel_program, zfs_secpolicy_config,
              POOL_NAME, POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE,
              B_TRUE, zfs_keys_channel_program,
              ARRAY_SIZE(zfs_keys_channel_program));
  
          zfs_ioctl_register("redact", ZFS_IOC_REDACT,
              zfs_ioc_redact, zfs_secpolicy_config, DATASET_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE,
              zfs_keys_redact, ARRAY_SIZE(zfs_keys_redact));
  
          zfs_ioctl_register("zpool_checkpoint", ZFS_IOC_POOL_CHECKPOINT,
              zfs_ioc_pool_checkpoint, zfs_secpolicy_config, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE,
              zfs_keys_pool_checkpoint, ARRAY_SIZE(zfs_keys_pool_checkpoint));
  
          zfs_ioctl_register("zpool_discard_checkpoint",
              ZFS_IOC_POOL_DISCARD_CHECKPOINT, zfs_ioc_pool_discard_checkpoint,
              zfs_secpolicy_config, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE,
              zfs_keys_pool_discard_checkpoint,
              ARRAY_SIZE(zfs_keys_pool_discard_checkpoint));
  
          zfs_ioctl_register("initialize", ZFS_IOC_POOL_INITIALIZE,
              zfs_ioc_pool_initialize, zfs_secpolicy_config, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE,
              zfs_keys_pool_initialize, ARRAY_SIZE(zfs_keys_pool_initialize));
  
          zfs_ioctl_register("trim", ZFS_IOC_POOL_TRIM,
              zfs_ioc_pool_trim, zfs_secpolicy_config, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_TRUE, B_TRUE,
              zfs_keys_pool_trim, ARRAY_SIZE(zfs_keys_pool_trim));
  
          zfs_ioctl_register("wait", ZFS_IOC_WAIT,
              zfs_ioc_wait, zfs_secpolicy_none, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_FALSE,
              zfs_keys_pool_wait, ARRAY_SIZE(zfs_keys_pool_wait));
  
          zfs_ioctl_register("wait_fs", ZFS_IOC_WAIT_FS,
              zfs_ioc_wait_fs, zfs_secpolicy_none, DATASET_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_FALSE,
              zfs_keys_fs_wait, ARRAY_SIZE(zfs_keys_fs_wait));
  
          zfs_ioctl_register("set_bootenv", ZFS_IOC_SET_BOOTENV,
              zfs_ioc_set_bootenv, zfs_secpolicy_config, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_TRUE,
              zfs_keys_set_bootenv, ARRAY_SIZE(zfs_keys_set_bootenv));
  
          zfs_ioctl_register("get_bootenv", ZFS_IOC_GET_BOOTENV,
              zfs_ioc_get_bootenv, zfs_secpolicy_none, POOL_NAME,
              POOL_CHECK_SUSPENDED, B_FALSE, B_TRUE,
              zfs_keys_get_bootenv, ARRAY_SIZE(zfs_keys_get_bootenv));
  
          zfs_ioctl_register("zpool_vdev_get_props", ZFS_IOC_VDEV_GET_PROPS,
              zfs_ioc_vdev_get_props, zfs_secpolicy_read, POOL_NAME,
              POOL_CHECK_NONE, B_FALSE, B_FALSE, zfs_keys_vdev_get_props,
              ARRAY_SIZE(zfs_keys_vdev_get_props));
  
          zfs_ioctl_register("zpool_vdev_set_props", ZFS_IOC_VDEV_SET_PROPS,
              zfs_ioc_vdev_set_props, zfs_secpolicy_config, POOL_NAME,
              POOL_CHECK_SUSPENDED | POOL_CHECK_READONLY, B_FALSE, B_FALSE,
              zfs_keys_vdev_set_props, ARRAY_SIZE(zfs_keys_vdev_set_props));
  
          /* 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_READONLY);
  
          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);
  
          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);
  
          zfs_ioctl_init_os();
  }
  
  /*
   * Verify that for non-legacy ioctls the input nvlist
   * pairs match against the expected input.
   *
   * Possible errors are:
   * ZFS_ERR_IOC_ARG_UNAVAIL      An unrecognized nvpair was encountered
   * ZFS_ERR_IOC_ARG_REQUIRED     A required nvpair is missing
   * ZFS_ERR_IOC_ARG_BADTYPE      Invalid type for nvpair
   */
  static int
  zfs_check_input_nvpairs(nvlist_t *innvl, const zfs_ioc_vec_t *vec)
  {
          const zfs_ioc_key_t *nvl_keys = vec->zvec_nvl_keys;
          boolean_t required_keys_found = B_FALSE;
  
          /*
           * examine each input pair
           */
          for (nvpair_t *pair = nvlist_next_nvpair(innvl, NULL);
              pair != NULL; pair = nvlist_next_nvpair(innvl, pair)) {
                  char *name = nvpair_name(pair);
                  data_type_t type = nvpair_type(pair);
                  boolean_t identified = B_FALSE;
  
                  /*
                   * check pair against the documented names and type
                   */
                  for (int k = 0; k < vec->zvec_nvl_key_count; k++) {
                          /* if not a wild card name, check for an exact match */
                          if ((nvl_keys[k].zkey_flags & ZK_WILDCARDLIST) == 0 &&
                              strcmp(nvl_keys[k].zkey_name, name) != 0)
                                  continue;
  
                          identified = B_TRUE;
  
                          if (nvl_keys[k].zkey_type != DATA_TYPE_ANY &&
                              nvl_keys[k].zkey_type != type) {
                                  return (SET_ERROR(ZFS_ERR_IOC_ARG_BADTYPE));
                          }
  
                          if (nvl_keys[k].zkey_flags & ZK_OPTIONAL)
                                  continue;
  
                          required_keys_found = B_TRUE;
                          break;
                  }
  
                  /* allow an 'optional' key, everything else is invalid */
                  if (!identified &&
                      (strcmp(name, "optional") != 0 ||
                      type != DATA_TYPE_NVLIST)) {
                          return (SET_ERROR(ZFS_ERR_IOC_ARG_UNAVAIL));
                  }
          }
  
          /* verify that all required keys were found */
          for (int k = 0; k < vec->zvec_nvl_key_count; k++) {
                  if (nvl_keys[k].zkey_flags & ZK_OPTIONAL)
                          continue;
  
                  if (nvl_keys[k].zkey_flags & ZK_WILDCARDLIST) {
                          /* at least one non-optional key is expected here */
                          if (!required_keys_found)
                                  return (SET_ERROR(ZFS_ERR_IOC_ARG_REQUIRED));
                          continue;
                  }
  
                  if (!nvlist_exists(innvl, nvl_keys[k].zkey_name))
                          return (SET_ERROR(ZFS_ERR_IOC_ARG_REQUIRED));
          }
  
          return (0);
  }
  
  static 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 ||
              type == ENTITY_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);
  }
  
  int
  zfsdev_getminor(zfs_file_t *fp, minor_t *minorp)
  {
          zfsdev_state_t *zs, *fpd;
  
          ASSERT(!MUTEX_HELD(&zfsdev_state_lock));
  
          fpd = zfs_file_private(fp);
          if (fpd == NULL)
                  return (SET_ERROR(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 (SET_ERROR(EBADF));
  }
  
  void *
  zfsdev_get_state(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) {
                          membar_consumer();
                          switch (which) {
                          case ZST_ONEXIT:
                                  return (zs->zs_onexit);
                          case ZST_ZEVENT:
                                  return (zs->zs_zevent);
                          case ZST_ALL:
                                  return (zs);
                          }
                  }
          }
  
          return (NULL);
  }
  
  /*
   * 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.
   */
  static 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(m, ZST_ALL) == NULL) {
                          last_minor = m;
                          return (m);
                  }
          }
  
          return (0);
  }
  
  int
  zfsdev_state_init(void *priv)
  {
          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;
          }
  
          zfsdev_private_set_state(priv, 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(), 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;
                  membar_producer();
                  zsprev->zs_next = zs;
          } else {
                  membar_producer();
                  zs->zs_minor = minor;
          }
  
          return (0);
  }
  
  void
  zfsdev_state_destroy(void *priv)
  {
          zfsdev_state_t *zs = zfsdev_private_get_state(priv);
  
          ASSERT(zs != NULL);
          ASSERT3S(zs->zs_minor, >, 0);
  
          /*
           * The last reference to this zfsdev file descriptor is being dropped.
           * We don't have to worry about lookup grabbing this state object, and
           * zfsdev_state_init() will not try to reuse this object until it is
           * invalidated by setting zs_minor to -1.  Invalidation must be done
           * last, with a memory barrier to ensure ordering.  This lets us avoid
           * taking the global zfsdev state lock around destruction.
           */
          zfs_onexit_destroy(zs->zs_onexit);
          zfs_zevent_destroy(zs->zs_zevent);
          zs->zs_onexit = NULL;
          zs->zs_zevent = NULL;
          membar_producer();
          zs->zs_minor = -1;
  }
  
  long
  zfsdev_ioctl_common(uint_t vecnum, zfs_cmd_t *zc, int flag)
  {
          int error, cmd;
          const zfs_ioc_vec_t *vec;
          char *saved_poolname = NULL;
          uint64_t max_nvlist_src_size;
          size_t saved_poolname_len = 0;
          nvlist_t *innvl = NULL;
          fstrans_cookie_t cookie;
          hrtime_t start_time = gethrtime();
  
          cmd = vecnum;
          error = 0;
          if (vecnum >= sizeof (zfs_ioc_vec) / sizeof (zfs_ioc_vec[0]))
                  return (SET_ERROR(ZFS_ERR_IOC_CMD_UNAVAIL));
  
          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(ZFS_ERR_IOC_CMD_UNAVAIL));
  
          zc->zc_iflags = flag & FKIOCTL;
          max_nvlist_src_size = zfs_max_nvlist_src_size_os();
          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 ENTITY_NAME:
                  if (entity_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;
          }
          /*
           * Ensure that all input pairs are valid before we pass them down
           * to the lower layers.
           *
           * The vectored functions can use fnvlist_lookup_{type} for any
           * required pairs since zfs_check_input_nvpairs() confirmed that
           * they exist and are of the correct type.
           */
          if (error == 0 && vec->zvec_func != NULL) {
                  error = zfs_check_input_nvpairs(innvl, vec);
                  if (error != 0)
                          goto out;
          }
  
          if (error == 0) {
                  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 */
          /*
           * Can't use kmem_strdup() as we might truncate the string and
           * kmem_strfree() would then free with incorrect size.
           */
          saved_poolname_len = strlen(zc->zc_name) + 1;
          saved_poolname = kmem_alloc(saved_poolname_len, KM_SLEEP);
  
          strlcpy(saved_poolname, zc->zc_name, saved_poolname_len);
          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);
  
                  /*
                   * Some commands can partially execute, modify state, and still
                   * return an error.  In these cases, attempt to record what
                   * was modified.
                   */
                  if ((error == 0 ||
                      (cmd == ZFS_IOC_CHANNEL_PROGRAM && error != EINVAL)) &&
                      vec->zvec_allow_log &&
                      spa_open(zc->zc_name, &spa, FTAG) == 0) {
                          if (!nvlist_empty(outnvl)) {
                                  size_t out_size = fnvlist_size(outnvl);
                                  if (out_size > zfs_history_output_max) {
                                          fnvlist_add_int64(lognv,
                                              ZPOOL_HIST_OUTPUT_SIZE, out_size);
                                  } else {
                                          fnvlist_add_nvlist(lognv,
                                              ZPOOL_HIST_OUTPUT_NVL, outnvl);
                                  }
                          }
                          if (error != 0) {
                                  fnvlist_add_int64(lognv, ZPOOL_HIST_ERRNO,
                                      error);
                          }
                          fnvlist_add_int64(lognv, ZPOOL_HIST_ELAPSED_NS,
                              gethrtime() - start_time);
                          (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);
          if (error == 0 && vec->zvec_allow_log) {
                  char *s = tsd_get(zfs_allow_log_key);
                  if (s != NULL)
                          kmem_strfree(s);
                  (void) tsd_set(zfs_allow_log_key, kmem_strdup(saved_poolname));
          }
          if (saved_poolname != NULL)
                  kmem_free(saved_poolname, saved_poolname_len);
  
          return (error);
  }
  
  int
  zfs_kmod_init(void)
  {
          int error;
  
          if ((error = zvol_init()) != 0)
                  return (error);
  
          spa_init(SPA_MODE_READ | SPA_MODE_WRITE);
          zfs_init();
  
          zfs_ioctl_init();
  
          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;
  
          if ((error = zfsdev_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);
  
          return (0);
  out:
          zfs_fini();
          spa_fini();
          zvol_fini();
  
          return (error);
  }
  
  void
  zfs_kmod_fini(void)
  {
          zfsdev_state_t *zs, *zsnext = NULL;
  
          zfsdev_detach();
  
          mutex_destroy(&zfsdev_state_lock);
  
          for (zs = zfsdev_state_list; zs != NULL; zs = zsnext) {
                  zsnext = zs->zs_next;
                  if (zs->zs_onexit)
                          zfs_onexit_destroy(zs->zs_onexit);
                  if (zs->zs_zevent)
                          zfs_zevent_destroy(zs->zs_zevent);
                  kmem_free(zs, sizeof (zfsdev_state_t));
          }
  
          zfs_ereport_taskq_fini();       /* run before zfs_fini() on Linux */
          zfs_fini();
          spa_fini();
          zvol_fini();
  
          tsd_destroy(&zfs_fsyncer_key);
          tsd_destroy(&rrw_tsd_key);
          tsd_destroy(&zfs_allow_log_key);
  }
  
  ZFS_MODULE_PARAM(zfs, zfs_, max_nvlist_src_size, U64, ZMOD_RW,
          "Maximum size in bytes allowed for src nvlist passed with ZFS ioctls");
  
  ZFS_MODULE_PARAM(zfs, zfs_, history_output_max, U64, ZMOD_RW,
          "Maximum size in bytes of ZFS ioctl output that will be logged");