/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
 * Copyright (c) 2013 Martin Matuska. All rights reserved.
 * Copyright 2019 Joyent, Inc.
 */

#include <sys/zfs_context.h>
#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_tx.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_prop.h>
#include <sys/dsl_synctask.h>
#include <sys/spa.h>
#include <sys/zap.h>
#include <sys/fs/zfs.h>

#include "zfs_prop.h"

#define ZPROP_INHERIT_SUFFIX "$inherit"
#define ZPROP_RECVD_SUFFIX "$recvd"

static int
dodefault(zfs_prop_t prop, int intsz, int numints, void *buf)
{
        /*
         * The setonce properties are read-only, BUT they still
         * have a default value that can be used as the initial
         * value.
         */
        if (prop == ZPROP_INVAL ||
            (zfs_prop_readonly(prop) && !zfs_prop_setonce(prop)))
                return (SET_ERROR(ENOENT));

        if (zfs_prop_get_type(prop) == PROP_TYPE_STRING) {
                if (intsz != 1)
                        return (SET_ERROR(EOVERFLOW));
                (void) strncpy(buf, zfs_prop_default_string(prop),
                    numints);
        } else {
                if (intsz != 8 || numints < 1)
                        return (SET_ERROR(EOVERFLOW));

                *(uint64_t *)buf = zfs_prop_default_numeric(prop);
        }

        return (0);
}

int
dsl_prop_get_dd(dsl_dir_t *dd, const char *propname,
    int intsz, int numints, void *buf, char *setpoint, boolean_t snapshot)
{
        int err = ENOENT;
        dsl_dir_t *target = dd;
        objset_t *mos = dd->dd_pool->dp_meta_objset;
        zfs_prop_t prop;
        boolean_t inheritable;
        boolean_t inheriting = B_FALSE;
        char *inheritstr;
        char *recvdstr;

        ASSERT(dsl_pool_config_held(dd->dd_pool));

        if (setpoint)
                setpoint[0] = '\0';

        prop = zfs_name_to_prop(propname);
        inheritable = (prop == ZPROP_INVAL || zfs_prop_inheritable(prop));
        inheritstr = kmem_asprintf("%s%s", propname, ZPROP_INHERIT_SUFFIX);
        recvdstr = kmem_asprintf("%s%s", propname, ZPROP_RECVD_SUFFIX);

        /*
         * Note: dd may become NULL, therefore we shouldn't dereference it
         * after this loop.
         */
        for (; dd != NULL; dd = dd->dd_parent) {
                if (dd != target || snapshot) {
                        if (!inheritable)
                                break;
                        inheriting = B_TRUE;
                }

                /* Check for a local value. */
                err = zap_lookup(mos, dsl_dir_phys(dd)->dd_props_zapobj,
                    propname, intsz, numints, buf);
                if (err != ENOENT) {
                        if (setpoint != NULL && err == 0)
                                dsl_dir_name(dd, setpoint);
                        break;
                }

                /*
                 * Skip the check for a received value if there is an explicit
                 * inheritance entry.
                 */
                err = zap_contains(mos, dsl_dir_phys(dd)->dd_props_zapobj,
                    inheritstr);
                if (err != 0 && err != ENOENT)
                        break;

                if (err == ENOENT) {
                        /* Check for a received value. */
                        err = zap_lookup(mos, dsl_dir_phys(dd)->dd_props_zapobj,
                            recvdstr, intsz, numints, buf);
                        if (err != ENOENT) {
                                if (setpoint != NULL && err == 0) {
                                        if (inheriting) {
                                                dsl_dir_name(dd, setpoint);
                                        } else {
                                                (void) strcpy(setpoint,
                                                    ZPROP_SOURCE_VAL_RECVD);
                                        }
                                }
                                break;
                        }
                }

                /*
                 * If we found an explicit inheritance entry, err is zero even
                 * though we haven't yet found the value, so reinitializing err
                 * at the end of the loop (instead of at the beginning) ensures
                 * that err has a valid post-loop value.
                 */
                err = SET_ERROR(ENOENT);
        }

        if (err == ENOENT)
                err = dodefault(prop, intsz, numints, buf);

        strfree(inheritstr);
        strfree(recvdstr);

        return (err);
}

int
dsl_prop_get_ds(dsl_dataset_t *ds, const char *propname,
    int intsz, int numints, void *buf, char *setpoint)
{
        zfs_prop_t prop = zfs_name_to_prop(propname);
        boolean_t inheritable;
        uint64_t zapobj;

        ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
        inheritable = (prop == ZPROP_INVAL || zfs_prop_inheritable(prop));
        zapobj = dsl_dataset_phys(ds)->ds_props_obj;

        if (zapobj != 0) {
                objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
                int err;

                ASSERT(ds->ds_is_snapshot);

                /* Check for a local value. */
                err = zap_lookup(mos, zapobj, propname, intsz, numints, buf);
                if (err != ENOENT) {
                        if (setpoint != NULL && err == 0)
                                dsl_dataset_name(ds, setpoint);
                        return (err);
                }

                /*
                 * Skip the check for a received value if there is an explicit
                 * inheritance entry.
                 */
                if (inheritable) {
                        char *inheritstr = kmem_asprintf("%s%s", propname,
                            ZPROP_INHERIT_SUFFIX);
                        err = zap_contains(mos, zapobj, inheritstr);
                        strfree(inheritstr);
                        if (err != 0 && err != ENOENT)
                                return (err);
                }

                if (err == ENOENT) {
                        /* Check for a received value. */
                        char *recvdstr = kmem_asprintf("%s%s", propname,
                            ZPROP_RECVD_SUFFIX);
                        err = zap_lookup(mos, zapobj, recvdstr,
                            intsz, numints, buf);
                        strfree(recvdstr);
                        if (err != ENOENT) {
                                if (setpoint != NULL && err == 0)
                                        (void) strcpy(setpoint,
                                            ZPROP_SOURCE_VAL_RECVD);
                                return (err);
                        }
                }
        }

        return (dsl_prop_get_dd(ds->ds_dir, propname,
            intsz, numints, buf, setpoint, ds->ds_is_snapshot));
}

static dsl_prop_record_t *
dsl_prop_record_find(dsl_dir_t *dd, const char *propname)
{
        dsl_prop_record_t *pr = NULL;

        ASSERT(MUTEX_HELD(&dd->dd_lock));

        for (pr = list_head(&dd->dd_props);
            pr != NULL; pr = list_next(&dd->dd_props, pr)) {
                if (strcmp(pr->pr_propname, propname) == 0)
                        break;
        }

        return (pr);
}

static dsl_prop_record_t *
dsl_prop_record_create(dsl_dir_t *dd, const char *propname)
{
        dsl_prop_record_t *pr;

        ASSERT(MUTEX_HELD(&dd->dd_lock));

        pr = kmem_alloc(sizeof (dsl_prop_record_t), KM_SLEEP);
        pr->pr_propname = spa_strdup(propname);
        list_create(&pr->pr_cbs, sizeof (dsl_prop_cb_record_t),
            offsetof(dsl_prop_cb_record_t, cbr_pr_node));
        list_insert_head(&dd->dd_props, pr);

        return (pr);
}

void
dsl_prop_init(dsl_dir_t *dd)
{
        list_create(&dd->dd_props, sizeof (dsl_prop_record_t),
            offsetof(dsl_prop_record_t, pr_node));
}

void
dsl_prop_fini(dsl_dir_t *dd)
{
        dsl_prop_record_t *pr;

        while ((pr = list_remove_head(&dd->dd_props)) != NULL) {
                list_destroy(&pr->pr_cbs);
                strfree((char *)pr->pr_propname);
                kmem_free(pr, sizeof (dsl_prop_record_t));
        }
        list_destroy(&dd->dd_props);
}

/*
 * Register interest in the named property.  We'll call the callback
 * once to notify it of the current property value, and again each time
 * the property changes, until this callback is unregistered.
 *
 * Return 0 on success, errno if the prop is not an integer value.
 */
int
dsl_prop_register(dsl_dataset_t *ds, const char *propname,
    dsl_prop_changed_cb_t *callback, void *cbarg)
{
        dsl_dir_t *dd = ds->ds_dir;
        dsl_pool_t *dp = dd->dd_pool;
        uint64_t value;
        dsl_prop_record_t *pr;
        dsl_prop_cb_record_t *cbr;
        int err;

        ASSERT(dsl_pool_config_held(dp));

        err = dsl_prop_get_int_ds(ds, propname, &value);
        if (err != 0)
                return (err);

        cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);
        cbr->cbr_ds = ds;
        cbr->cbr_func = callback;
        cbr->cbr_arg = cbarg;

        mutex_enter(&dd->dd_lock);
        pr = dsl_prop_record_find(dd, propname);
        if (pr == NULL)
                pr = dsl_prop_record_create(dd, propname);
        cbr->cbr_pr = pr;
        list_insert_head(&pr->pr_cbs, cbr);
        list_insert_head(&ds->ds_prop_cbs, cbr);
        mutex_exit(&dd->dd_lock);

        cbr->cbr_func(cbr->cbr_arg, value);
        return (0);
}

int
dsl_prop_get(const char *dsname, const char *propname,
    int intsz, int numints, void *buf, char *setpoint)
{
        objset_t *os;
        int error;

        error = dmu_objset_hold(dsname, FTAG, &os);
        if (error != 0)
                return (error);

        error = dsl_prop_get_ds(dmu_objset_ds(os), propname,
            intsz, numints, buf, setpoint);

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

/*
 * Get the current property value.  It may have changed by the time this
 * function returns, so it is NOT safe to follow up with
 * dsl_prop_register() and assume that the value has not changed in
 * between.
 *
 * Return 0 on success, ENOENT if ddname is invalid.
 */
int
dsl_prop_get_integer(const char *ddname, const char *propname,
    uint64_t *valuep, char *setpoint)
{
        return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
}

int
dsl_prop_get_int_ds(dsl_dataset_t *ds, const char *propname,
    uint64_t *valuep)
{
        return (dsl_prop_get_ds(ds, propname, 8, 1, valuep, NULL));
}

/*
 * Predict the effective value of the given special property if it were set with
 * the given value and source. This is not a general purpose function. It exists
 * only to handle the special requirements of the quota and reservation
 * properties. The fact that these properties are non-inheritable greatly
 * simplifies the prediction logic.
 *
 * Returns 0 on success, a positive error code on failure, or -1 if called with
 * a property not handled by this function.
 */
int
dsl_prop_predict(dsl_dir_t *dd, const char *propname,
    zprop_source_t source, uint64_t value, uint64_t *newvalp)
{
        zfs_prop_t prop = zfs_name_to_prop(propname);
        objset_t *mos;
        uint64_t zapobj;
        uint64_t version;
        char *recvdstr;
        int err = 0;

        switch (prop) {
        case ZFS_PROP_QUOTA:
        case ZFS_PROP_RESERVATION:
        case ZFS_PROP_REFQUOTA:
        case ZFS_PROP_REFRESERVATION:
                break;
        default:
                return (-1);
        }

        mos = dd->dd_pool->dp_meta_objset;
        zapobj = dsl_dir_phys(dd)->dd_props_zapobj;
        recvdstr = kmem_asprintf("%s%s", propname, ZPROP_RECVD_SUFFIX);

        version = spa_version(dd->dd_pool->dp_spa);
        if (version < SPA_VERSION_RECVD_PROPS) {
                if (source & ZPROP_SRC_NONE)
                        source = ZPROP_SRC_NONE;
                else if (source & ZPROP_SRC_RECEIVED)
                        source = ZPROP_SRC_LOCAL;
        }

        switch (source) {
        case ZPROP_SRC_NONE:
                /* Revert to the received value, if any. */
                err = zap_lookup(mos, zapobj, recvdstr, 8, 1, newvalp);
                if (err == ENOENT)
                        *newvalp = 0;
                break;
        case ZPROP_SRC_LOCAL:
                *newvalp = value;
                break;
        case ZPROP_SRC_RECEIVED:
                /*
                 * If there's no local setting, then the new received value will
                 * be the effective value.
                 */
                err = zap_lookup(mos, zapobj, propname, 8, 1, newvalp);
                if (err == ENOENT)
                        *newvalp = value;
                break;
        case (ZPROP_SRC_NONE | ZPROP_SRC_RECEIVED):
                /*
                 * We're clearing the received value, so the local setting (if
                 * it exists) remains the effective value.
                 */
                err = zap_lookup(mos, zapobj, propname, 8, 1, newvalp);
                if (err == ENOENT)
                        *newvalp = 0;
                break;
        default:
                panic("unexpected property source: %d", source);
        }

        strfree(recvdstr);

        if (err == ENOENT)
                return (0);

        return (err);
}

/*
 * Unregister all callbacks that are registered with the
 * given callback argument.
 */
void
dsl_prop_unregister_all(dsl_dataset_t *ds, void *cbarg)
{
        dsl_prop_cb_record_t *cbr, *next_cbr;

        dsl_dir_t *dd = ds->ds_dir;

        mutex_enter(&dd->dd_lock);
        next_cbr = list_head(&ds->ds_prop_cbs);
        while (next_cbr != NULL) {
                cbr = next_cbr;
                next_cbr = list_next(&ds->ds_prop_cbs, cbr);
                if (cbr->cbr_arg == cbarg) {
                        list_remove(&ds->ds_prop_cbs, cbr);
                        list_remove(&cbr->cbr_pr->pr_cbs, cbr);
                        kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
                }
        }
        mutex_exit(&dd->dd_lock);
}

boolean_t
dsl_prop_hascb(dsl_dataset_t *ds)
{
        return (!list_is_empty(&ds->ds_prop_cbs));
}

/* ARGSUSED */
static int
dsl_prop_notify_all_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
{
        dsl_dir_t *dd = ds->ds_dir;
        dsl_prop_record_t *pr;
        dsl_prop_cb_record_t *cbr;

        mutex_enter(&dd->dd_lock);
        for (pr = list_head(&dd->dd_props);
            pr; pr = list_next(&dd->dd_props, pr)) {
                for (cbr = list_head(&pr->pr_cbs); cbr;
                    cbr = list_next(&pr->pr_cbs, cbr)) {
                        uint64_t value;

                        /*
                         * Callback entries do not have holds on their
                         * datasets so that datasets with registered
                         * callbacks are still eligible for eviction.
                         * Unlike operations to update properties on a
                         * single dataset, we are performing a recursive
                         * descent of related head datasets.  The caller
                         * of this function only has a dataset hold on
                         * the passed in head dataset, not the snapshots
                         * associated with this dataset.  Without a hold,
                         * the dataset pointer within callback records
                         * for snapshots can be invalidated by eviction
                         * at any time.
                         *
                         * Use dsl_dataset_try_add_ref() to verify
                         * that the dataset for a snapshot has not
                         * begun eviction processing and to prevent
                         * eviction from occurring for the duration of
                         * the callback.  If the hold attempt fails,
                         * this object is already being evicted and the
                         * callback can be safely ignored.
                         */
                        if (ds != cbr->cbr_ds &&
                            !dsl_dataset_try_add_ref(dp, cbr->cbr_ds, FTAG))
                                continue;

                        if (dsl_prop_get_ds(cbr->cbr_ds,
                            cbr->cbr_pr->pr_propname, sizeof (value), 1,
                            &value, NULL) == 0)
                                cbr->cbr_func(cbr->cbr_arg, value);

                        if (ds != cbr->cbr_ds)
                                dsl_dataset_rele(cbr->cbr_ds, FTAG);
                }
        }
        mutex_exit(&dd->dd_lock);

        return (0);
}

/*
 * Update all property values for ddobj & its descendants.  This is used
 * when renaming the dir.
 */
void
dsl_prop_notify_all(dsl_dir_t *dd)
{
        dsl_pool_t *dp = dd->dd_pool;
        ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
        (void) dmu_objset_find_dp(dp, dd->dd_object, dsl_prop_notify_all_cb,
            NULL, DS_FIND_CHILDREN);
}

static void
dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
    const char *propname, uint64_t value, int first)
{
        dsl_dir_t *dd;
        dsl_prop_record_t *pr;
        dsl_prop_cb_record_t *cbr;
        objset_t *mos = dp->dp_meta_objset;
        zap_cursor_t zc;
        zap_attribute_t *za;
        int err;

        ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
        err = dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd);
        if (err)
                return;

        if (!first) {
                /*
                 * If the prop is set here, then this change is not
                 * being inherited here or below; stop the recursion.
                 */
                err = zap_contains(mos, dsl_dir_phys(dd)->dd_props_zapobj,
                    propname);
                if (err == 0) {
                        dsl_dir_rele(dd, FTAG);
                        return;
                }
                ASSERT3U(err, ==, ENOENT);
        }

        mutex_enter(&dd->dd_lock);
        pr = dsl_prop_record_find(dd, propname);
        if (pr != NULL) {
                for (cbr = list_head(&pr->pr_cbs); cbr;
                    cbr = list_next(&pr->pr_cbs, cbr)) {
                        uint64_t propobj;

                        /*
                         * cbr->cbr_ds may be invalidated due to eviction,
                         * requiring the use of dsl_dataset_try_add_ref().
                         * See comment block in dsl_prop_notify_all_cb()
                         * for details.
                         */
                        if (!dsl_dataset_try_add_ref(dp, cbr->cbr_ds, FTAG))
                                continue;

                        propobj = dsl_dataset_phys(cbr->cbr_ds)->ds_props_obj;

                        /*
                         * If the property is not set on this ds, then it is
                         * inherited here; call the callback.
                         */
                        if (propobj == 0 ||
                            zap_contains(mos, propobj, propname) != 0)
                                cbr->cbr_func(cbr->cbr_arg, value);

                        dsl_dataset_rele(cbr->cbr_ds, FTAG);
                }
        }
        mutex_exit(&dd->dd_lock);

        za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
        for (zap_cursor_init(&zc, mos,
            dsl_dir_phys(dd)->dd_child_dir_zapobj);
            zap_cursor_retrieve(&zc, za) == 0;
            zap_cursor_advance(&zc)) {
                dsl_prop_changed_notify(dp, za->za_first_integer,
                    propname, value, FALSE);
        }
        kmem_free(za, sizeof (zap_attribute_t));
        zap_cursor_fini(&zc);
        dsl_dir_rele(dd, FTAG);
}

void
dsl_prop_set_sync_impl(dsl_dataset_t *ds, const char *propname,
    zprop_source_t source, int intsz, int numints, const void *value,
    dmu_tx_t *tx)
{
        objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
        uint64_t zapobj, intval, dummy;
        int isint;
        char valbuf[32];
        const char *valstr = NULL;
        char *inheritstr;
        char *recvdstr;
        char *tbuf = NULL;
        int err;
        uint64_t version = spa_version(ds->ds_dir->dd_pool->dp_spa);

        isint = (dodefault(zfs_name_to_prop(propname), 8, 1, &intval) == 0);

        if (ds->ds_is_snapshot) {
                ASSERT(version >= SPA_VERSION_SNAP_PROPS);
                if (dsl_dataset_phys(ds)->ds_props_obj == 0) {
                        dmu_buf_will_dirty(ds->ds_dbuf, tx);
                        dsl_dataset_phys(ds)->ds_props_obj =
                            zap_create(mos,
                            DMU_OT_DSL_PROPS, DMU_OT_NONE, 0, tx);
                }
                zapobj = dsl_dataset_phys(ds)->ds_props_obj;
        } else {
                zapobj = dsl_dir_phys(ds->ds_dir)->dd_props_zapobj;
        }

        if (version < SPA_VERSION_RECVD_PROPS) {
                if (source & ZPROP_SRC_NONE)
                        source = ZPROP_SRC_NONE;
                else if (source & ZPROP_SRC_RECEIVED)
                        source = ZPROP_SRC_LOCAL;
        }

        inheritstr = kmem_asprintf("%s%s", propname, ZPROP_INHERIT_SUFFIX);
        recvdstr = kmem_asprintf("%s%s", propname, ZPROP_RECVD_SUFFIX);

        switch (source) {
        case ZPROP_SRC_NONE:
                /*
                 * revert to received value, if any (inherit -S)
                 * - remove propname
                 * - remove propname$inherit
                 */
                err = zap_remove(mos, zapobj, propname, tx);
                ASSERT(err == 0 || err == ENOENT);
                err = zap_remove(mos, zapobj, inheritstr, tx);
                ASSERT(err == 0 || err == ENOENT);
                break;
        case ZPROP_SRC_LOCAL:
                /*
                 * remove propname$inherit
                 * set propname -> value
                 */
                err = zap_remove(mos, zapobj, inheritstr, tx);
                ASSERT(err == 0 || err == ENOENT);
                VERIFY0(zap_update(mos, zapobj, propname,
                    intsz, numints, value, tx));
                break;
        case ZPROP_SRC_INHERITED:
                /*
                 * explicitly inherit
                 * - remove propname
                 * - set propname$inherit
                 */
                err = zap_remove(mos, zapobj, propname, tx);
                ASSERT(err == 0 || err == ENOENT);
                if (version >= SPA_VERSION_RECVD_PROPS &&
                    dsl_prop_get_int_ds(ds, ZPROP_HAS_RECVD, &dummy) == 0) {
                        dummy = 0;
                        VERIFY0(zap_update(mos, zapobj, inheritstr,
                            8, 1, &dummy, tx));
                }
                break;
        case ZPROP_SRC_RECEIVED:
                /*
                 * set propname$recvd -> value
                 */
                err = zap_update(mos, zapobj, recvdstr,
                    intsz, numints, value, tx);
                ASSERT(err == 0);
                break;
        case (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED):
                /*
                 * clear local and received settings
                 * - remove propname
                 * - remove propname$inherit
                 * - remove propname$recvd
                 */
                err = zap_remove(mos, zapobj, propname, tx);
                ASSERT(err == 0 || err == ENOENT);
                err = zap_remove(mos, zapobj, inheritstr, tx);
                ASSERT(err == 0 || err == ENOENT);
                /* FALLTHRU */
        case (ZPROP_SRC_NONE | ZPROP_SRC_RECEIVED):
                /*
                 * remove propname$recvd
                 */
                err = zap_remove(mos, zapobj, recvdstr, tx);
                ASSERT(err == 0 || err == ENOENT);
                break;
        default:
                cmn_err(CE_PANIC, "unexpected property source: %d", source);
        }

        strfree(inheritstr);
        strfree(recvdstr);

        if (isint) {
                VERIFY0(dsl_prop_get_int_ds(ds, propname, &intval));

                if (ds->ds_is_snapshot) {
                        dsl_prop_cb_record_t *cbr;
                        /*
                         * It's a snapshot; nothing can inherit this
                         * property, so just look for callbacks on this
                         * ds here.
                         */
                        mutex_enter(&ds->ds_dir->dd_lock);
                        for (cbr = list_head(&ds->ds_prop_cbs); cbr;
                            cbr = list_next(&ds->ds_prop_cbs, cbr)) {
                                if (strcmp(cbr->cbr_pr->pr_propname,
                                    propname) == 0)
                                        cbr->cbr_func(cbr->cbr_arg, intval);
                        }
                        mutex_exit(&ds->ds_dir->dd_lock);
                } else {
                        dsl_prop_changed_notify(ds->ds_dir->dd_pool,
                            ds->ds_dir->dd_object, propname, intval, TRUE);
                }

                (void) snprintf(valbuf, sizeof (valbuf),
                    "%lld", (longlong_t)intval);
                valstr = valbuf;
        } else {
                if (source == ZPROP_SRC_LOCAL) {
                        valstr = value;
                } else {
                        tbuf = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
                        if (dsl_prop_get_ds(ds, propname, 1,
                            ZAP_MAXVALUELEN, tbuf, NULL) == 0)
                                valstr = tbuf;
                }
        }

        spa_history_log_internal_ds(ds, (source == ZPROP_SRC_NONE ||
            source == ZPROP_SRC_INHERITED) ? "inherit" : "set", tx,
            "%s=%s", propname, (valstr == NULL ? "" : valstr));

        if (tbuf != NULL)
                kmem_free(tbuf, ZAP_MAXVALUELEN);
}

int
dsl_prop_set_int(const char *dsname, const char *propname,
    zprop_source_t source, uint64_t value)
{
        nvlist_t *nvl = fnvlist_alloc();
        int error;

        fnvlist_add_uint64(nvl, propname, value);
        error = dsl_props_set(dsname, source, nvl);
        fnvlist_free(nvl);
        return (error);
}

int
dsl_prop_set_string(const char *dsname, const char *propname,
    zprop_source_t source, const char *value)
{
        nvlist_t *nvl = fnvlist_alloc();
        int error;

        fnvlist_add_string(nvl, propname, value);
        error = dsl_props_set(dsname, source, nvl);
        fnvlist_free(nvl);
        return (error);
}

int
dsl_prop_inherit(const char *dsname, const char *propname,
    zprop_source_t source)
{
        nvlist_t *nvl = fnvlist_alloc();
        int error;

        fnvlist_add_boolean(nvl, propname);
        error = dsl_props_set(dsname, source, nvl);
        fnvlist_free(nvl);
        return (error);
}

int
dsl_props_set_check(void *arg, dmu_tx_t *tx)
{
        dsl_props_set_arg_t *dpsa = arg;
        dsl_pool_t *dp = dmu_tx_pool(tx);
        dsl_dataset_t *ds;
        uint64_t version;
        nvpair_t *elem = NULL;
        int err;

        err = dsl_dataset_hold(dp, dpsa->dpsa_dsname, FTAG, &ds);
        if (err != 0)
                return (err);

        version = spa_version(ds->ds_dir->dd_pool->dp_spa);
        while ((elem = nvlist_next_nvpair(dpsa->dpsa_props, elem)) != NULL) {
                if (strlen(nvpair_name(elem)) >= ZAP_MAXNAMELEN) {
                        dsl_dataset_rele(ds, FTAG);
                        return (SET_ERROR(ENAMETOOLONG));
                }
                if (nvpair_type(elem) == DATA_TYPE_STRING) {
                        char *valstr = fnvpair_value_string(elem);
                        if (strlen(valstr) >= (version <
                            SPA_VERSION_STMF_PROP ?
                            ZAP_OLDMAXVALUELEN : ZAP_MAXVALUELEN)) {
                                dsl_dataset_rele(ds, FTAG);
                                return (E2BIG);
                        }
                }
        }

        if (ds->ds_is_snapshot && version < SPA_VERSION_SNAP_PROPS) {
                dsl_dataset_rele(ds, FTAG);
                return (SET_ERROR(ENOTSUP));
        }
        dsl_dataset_rele(ds, FTAG);
        return (0);
}

void
dsl_props_set_sync_impl(dsl_dataset_t *ds, zprop_source_t source,
    nvlist_t *props, dmu_tx_t *tx)
{
        nvpair_t *elem = NULL;

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

                if (nvpair_type(pair) == DATA_TYPE_NVLIST) {
                        /*
                         * This usually happens when we reuse the nvlist_t data
                         * returned by the counterpart dsl_prop_get_all_impl().
                         * For instance we do this to restore the original
                         * received properties when an error occurs in the
                         * zfs_ioc_recv() codepath.
                         */
                        nvlist_t *attrs = fnvpair_value_nvlist(pair);
                        pair = fnvlist_lookup_nvpair(attrs, ZPROP_VALUE);
                }

                if (nvpair_type(pair) == DATA_TYPE_STRING) {
                        const char *value = fnvpair_value_string(pair);
                        dsl_prop_set_sync_impl(ds, name,
                            source, 1, strlen(value) + 1, value, tx);
                } else if (nvpair_type(pair) == DATA_TYPE_UINT64) {
                        uint64_t intval = fnvpair_value_uint64(pair);
                        dsl_prop_set_sync_impl(ds, name,
                            source, sizeof (intval), 1, &intval, tx);
                } else if (nvpair_type(pair) == DATA_TYPE_BOOLEAN) {
                        dsl_prop_set_sync_impl(ds, name,
                            source, 0, 0, NULL, tx);
                } else {
                        panic("invalid nvpair type");
                }
        }
}

void
dsl_props_set_sync(void *arg, dmu_tx_t *tx)
{
        dsl_props_set_arg_t *dpsa = arg;
        dsl_pool_t *dp = dmu_tx_pool(tx);
        dsl_dataset_t *ds;

        VERIFY0(dsl_dataset_hold(dp, dpsa->dpsa_dsname, FTAG, &ds));
        dsl_props_set_sync_impl(ds, dpsa->dpsa_source, dpsa->dpsa_props, tx);
        dsl_dataset_rele(ds, FTAG);
}

/*
 * All-or-nothing; if any prop can't be set, nothing will be modified.
 */
int
dsl_props_set(const char *dsname, zprop_source_t source, nvlist_t *props)
{
        dsl_props_set_arg_t dpsa;
        int nblks = 0;

        dpsa.dpsa_dsname = dsname;
        dpsa.dpsa_source = source;
        dpsa.dpsa_props = props;

        /*
         * If the source includes NONE, then we will only be removing entries
         * from the ZAP object.  In that case don't check for ENOSPC.
         */
        if ((source & ZPROP_SRC_NONE) == 0)
                nblks = 2 * fnvlist_num_pairs(props);

        return (dsl_sync_task(dsname, dsl_props_set_check, dsl_props_set_sync,
            &dpsa, nblks, ZFS_SPACE_CHECK_RESERVED));
}

typedef enum dsl_prop_getflags {
        DSL_PROP_GET_INHERITING = 0x1,  /* searching parent of target ds */
        DSL_PROP_GET_SNAPSHOT = 0x2,    /* snapshot dataset */
        DSL_PROP_GET_LOCAL = 0x4,       /* local properties */
        DSL_PROP_GET_RECEIVED = 0x8,    /* received properties */
} dsl_prop_getflags_t;

static int
dsl_prop_get_all_impl(objset_t *mos, uint64_t propobj,
    const char *setpoint, dsl_prop_getflags_t flags, nvlist_t *nv)
{
        zap_cursor_t zc;
        zap_attribute_t za;
        int err = 0;

        for (zap_cursor_init(&zc, mos, propobj);
            (err = zap_cursor_retrieve(&zc, &za)) == 0;
            zap_cursor_advance(&zc)) {
                nvlist_t *propval;
                zfs_prop_t prop;
                char buf[ZAP_MAXNAMELEN];
                char *valstr;
                const char *suffix;
                const char *propname;
                const char *source;

                suffix = strchr(za.za_name, '$');

                if (suffix == NULL) {
                        /*
                         * Skip local properties if we only want received
                         * properties.
                         */
                        if (flags & DSL_PROP_GET_RECEIVED)
                                continue;

                        propname = za.za_name;
                        source = setpoint;
                } else if (strcmp(suffix, ZPROP_INHERIT_SUFFIX) == 0) {
                        /* Skip explicitly inherited entries. */
                        continue;
                } else if (strcmp(suffix, ZPROP_RECVD_SUFFIX) == 0) {
                        if (flags & DSL_PROP_GET_LOCAL)
                                continue;

                        (void) strncpy(buf, za.za_name, (suffix - za.za_name));
                        buf[suffix - za.za_name] = '\0';
                        propname = buf;

                        if (!(flags & DSL_PROP_GET_RECEIVED)) {
                                /* Skip if locally overridden. */
                                err = zap_contains(mos, propobj, propname);
                                if (err == 0)
                                        continue;
                                if (err != ENOENT)
                                        break;

                                /* Skip if explicitly inherited. */
                                valstr = kmem_asprintf("%s%s", propname,
                                    ZPROP_INHERIT_SUFFIX);
                                err = zap_contains(mos, propobj, valstr);
                                strfree(valstr);
                                if (err == 0)
                                        continue;
                                if (err != ENOENT)
                                        break;
                        }

                        source = ((flags & DSL_PROP_GET_INHERITING) ?
                            setpoint : ZPROP_SOURCE_VAL_RECVD);
                } else {
                        /*
                         * For backward compatibility, skip suffixes we don't
                         * recognize.
                         */
                        continue;
                }

                prop = zfs_name_to_prop(propname);

                /* Skip non-inheritable properties. */
                if ((flags & DSL_PROP_GET_INHERITING) && prop != ZPROP_INVAL &&
                    !zfs_prop_inheritable(prop))
                        continue;

                /* Skip properties not valid for this type. */
                if ((flags & DSL_PROP_GET_SNAPSHOT) && prop != ZPROP_INVAL &&
                    !zfs_prop_valid_for_type(prop, ZFS_TYPE_SNAPSHOT, B_FALSE))
                        continue;

                /* Skip properties already defined. */
                if (nvlist_exists(nv, propname))
                        continue;

                VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
                if (za.za_integer_length == 1) {
                        /*
                         * String property
                         */
                        char *tmp = kmem_alloc(za.za_num_integers,
                            KM_SLEEP);
                        err = zap_lookup(mos, propobj,
                            za.za_name, 1, za.za_num_integers, tmp);
                        if (err != 0) {
                                kmem_free(tmp, za.za_num_integers);
                                break;
                        }
                        VERIFY(nvlist_add_string(propval, ZPROP_VALUE,
                            tmp) == 0);
                        kmem_free(tmp, za.za_num_integers);
                } else {
                        /*
                         * Integer property
                         */
                        ASSERT(za.za_integer_length == 8);
                        (void) nvlist_add_uint64(propval, ZPROP_VALUE,
                            za.za_first_integer);
                }

                VERIFY(nvlist_add_string(propval, ZPROP_SOURCE, source) == 0);
                VERIFY(nvlist_add_nvlist(nv, propname, propval) == 0);
                nvlist_free(propval);
        }
        zap_cursor_fini(&zc);
        if (err == ENOENT)
                err = 0;
        return (err);
}

/*
 * Iterate over all properties for this dataset and return them in an nvlist.
 */
static int
dsl_prop_get_all_ds(dsl_dataset_t *ds, nvlist_t **nvp,
    dsl_prop_getflags_t flags)
{
        dsl_dir_t *dd = ds->ds_dir;
        dsl_pool_t *dp = dd->dd_pool;
        objset_t *mos = dp->dp_meta_objset;
        int err = 0;
        char setpoint[ZFS_MAX_DATASET_NAME_LEN];

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

        if (ds->ds_is_snapshot)
                flags |= DSL_PROP_GET_SNAPSHOT;

        ASSERT(dsl_pool_config_held(dp));

        if (dsl_dataset_phys(ds)->ds_props_obj != 0) {
                ASSERT(flags & DSL_PROP_GET_SNAPSHOT);
                dsl_dataset_name(ds, setpoint);
                err = dsl_prop_get_all_impl(mos,
                    dsl_dataset_phys(ds)->ds_props_obj, setpoint, flags, *nvp);
                if (err)
                        goto out;
        }

        for (; dd != NULL; dd = dd->dd_parent) {
                if (dd != ds->ds_dir || (flags & DSL_PROP_GET_SNAPSHOT)) {
                        if (flags & (DSL_PROP_GET_LOCAL |
                            DSL_PROP_GET_RECEIVED))
                                break;
                        flags |= DSL_PROP_GET_INHERITING;
                }
                dsl_dir_name(dd, setpoint);
                err = dsl_prop_get_all_impl(mos,
                    dsl_dir_phys(dd)->dd_props_zapobj, setpoint, flags, *nvp);
                if (err)
                        break;
        }

out:
        return (err);
}

boolean_t
dsl_prop_get_hasrecvd(const char *dsname)
{
        uint64_t dummy;

        return (0 ==
            dsl_prop_get_integer(dsname, ZPROP_HAS_RECVD, &dummy, NULL));
}

static int
dsl_prop_set_hasrecvd_impl(const char *dsname, zprop_source_t source)
{
        uint64_t version;
        spa_t *spa;
        int error = 0;

        VERIFY0(spa_open(dsname, &spa, FTAG));
        version = spa_version(spa);
        spa_close(spa, FTAG);

        if (version >= SPA_VERSION_RECVD_PROPS)
                error = dsl_prop_set_int(dsname, ZPROP_HAS_RECVD, source, 0);
        return (error);
}

/*
 * Call after successfully receiving properties to ensure that only the first
 * receive on or after SPA_VERSION_RECVD_PROPS blows away local properties.
 */
int
dsl_prop_set_hasrecvd(const char *dsname)
{
        int error = 0;
        if (!dsl_prop_get_hasrecvd(dsname))
                error = dsl_prop_set_hasrecvd_impl(dsname, ZPROP_SRC_LOCAL);
        return (error);
}

void
dsl_prop_unset_hasrecvd(const char *dsname)
{
        VERIFY0(dsl_prop_set_hasrecvd_impl(dsname, ZPROP_SRC_NONE));
}

int
dsl_prop_get_all(objset_t *os, nvlist_t **nvp)
{
        return (dsl_prop_get_all_ds(os->os_dsl_dataset, nvp, 0));
}

int
dsl_prop_get_received(const char *dsname, nvlist_t **nvp)
{
        objset_t *os;
        int error;

        /*
         * Received properties are not distinguishable from local properties
         * until the dataset has received properties on or after
         * SPA_VERSION_RECVD_PROPS.
         */
        dsl_prop_getflags_t flags = (dsl_prop_get_hasrecvd(dsname) ?
            DSL_PROP_GET_RECEIVED : DSL_PROP_GET_LOCAL);

        error = dmu_objset_hold(dsname, FTAG, &os);
        if (error != 0)
                return (error);
        error = dsl_prop_get_all_ds(os->os_dsl_dataset, nvp, flags);
        dmu_objset_rele(os, FTAG);
        return (error);
}

void
dsl_prop_nvlist_add_uint64(nvlist_t *nv, zfs_prop_t prop, uint64_t value)
{
        nvlist_t *propval;
        const char *propname = zfs_prop_to_name(prop);
        uint64_t default_value;

        if (nvlist_lookup_nvlist(nv, propname, &propval) == 0) {
                VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, value) == 0);
                return;
        }

        VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
        VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, value) == 0);
        /* Indicate the default source if we can. */
        if (dodefault(prop, 8, 1, &default_value) == 0 &&
            value == default_value) {
                VERIFY(nvlist_add_string(propval, ZPROP_SOURCE, "") == 0);
        }
        VERIFY(nvlist_add_nvlist(nv, propname, propval) == 0);
        nvlist_free(propval);
}

void
dsl_prop_nvlist_add_string(nvlist_t *nv, zfs_prop_t prop, const char *value)
{
        nvlist_t *propval;
        const char *propname = zfs_prop_to_name(prop);

        if (nvlist_lookup_nvlist(nv, propname, &propval) == 0) {
                VERIFY(nvlist_add_string(propval, ZPROP_VALUE, value) == 0);
                return;
        }

        VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
        VERIFY(nvlist_add_string(propval, ZPROP_VALUE, value) == 0);
        VERIFY(nvlist_add_nvlist(nv, propname, propval) == 0);
        nvlist_free(propval);
}