/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#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/zio_checksum.h> /* for the default checksum value */

#include <sys/zap.h>

#include <sys/fs/zfs.h>

#include "zfs_prop.h"

static int

dodefault(const char *propname, int intsz, int numint, void *buf)

{

	zfs_prop_t prop;

	/*

	 * The setonce properties are read-only, BUT they still

	 * have a default value that can be used as the initial

	 * value.

	 */

	if ((prop = zfs_name_to_prop(propname)) == ZPROP_INVAL ||

	    (zfs_prop_readonly(prop) && !zfs_prop_setonce(prop)))

		return (ENOENT);

	if (zfs_prop_get_type(prop) == PROP_TYPE_STRING) {

		if (intsz != 1)

			return (EOVERFLOW);

		(void) strncpy(buf, zfs_prop_default_string(prop),

		    numint);

	} else {

		if (intsz != 8 || numint < 1)

			return (EOVERFLOW);

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

	}

	return (0);

}

static int

dsl_prop_get_impl(dsl_dir_t *dd, const char *propname,

    int intsz, int numint, void *buf, char *setpoint)

{

	int err = ENOENT;

	zfs_prop_t prop;

	if (setpoint)

		setpoint[0] = '\0';

	prop = zfs_name_to_prop(propname);

	/*

	 * Note: dd may be NULL, therefore we shouldn't dereference it

	 * ouside this loop.

	 */

	for (; dd != NULL; dd = dd->dd_parent) {

		objset_t *mos = dd->dd_pool->dp_meta_objset;

		ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));

		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj,

		    propname, intsz, numint, buf);

		if (err != ENOENT) {

			if (setpoint)

				dsl_dir_name(dd, setpoint);

			break;

		}

		/*

		 * Break out of this loop for non-inheritable properties.

		 */

		if (prop != ZPROP_INVAL && !zfs_prop_inheritable(prop))

			break;

	}

	if (err == ENOENT)

		err = dodefault(propname, intsz, numint, buf);

	return (err);

}

/*

 * 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;

	uint64_t value;

	dsl_prop_cb_record_t *cbr;

	int err;

	int need_rwlock;

	need_rwlock = !RW_WRITE_HELD(&dd->dd_pool->dp_config_rwlock);

	if (need_rwlock)

		rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);

	err = dsl_prop_get_impl(dd, propname, 8, 1, &value, NULL);

	if (err != 0) {

		if (need_rwlock)

			rw_exit(&dd->dd_pool->dp_config_rwlock);

		return (err);

	}

	cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);

	cbr->cbr_ds = ds;

	cbr->cbr_propname = kmem_alloc(strlen(propname)+1, KM_SLEEP);

	(void) strcpy((char *)cbr->cbr_propname, propname);

	cbr->cbr_func = callback;

	cbr->cbr_arg = cbarg;

	mutex_enter(&dd->dd_lock);

	list_insert_head(&dd->dd_prop_cbs, cbr);

	mutex_exit(&dd->dd_lock);

	cbr->cbr_func(cbr->cbr_arg, value);

	VERIFY(0 == dsl_dir_open_obj(dd->dd_pool, dd->dd_object,

	    NULL, cbr, &dd));

	if (need_rwlock)

		rw_exit(&dd->dd_pool->dp_config_rwlock);

	/* Leave dataset open until this callback is unregistered */

	return (0);

}

int

dsl_prop_get_ds(dsl_dir_t *dd, const char *propname,

    int intsz, int numints, void *buf, char *setpoint)

{

	int err;

	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);

	err = dsl_prop_get_impl(dd, propname, intsz, numints, buf, setpoint);

	rw_exit(&dd->dd_pool->dp_config_rwlock);

	return (err);

}

/*

 * Get property when config lock is already held.

 */

int dsl_prop_get_ds_locked(dsl_dir_t *dd, const char *propname,

    int intsz, int numints, void *buf, char *setpoint)

{

	ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));

	return (dsl_prop_get_impl(dd, propname, intsz, numints, buf, setpoint));

}

int

dsl_prop_get(const char *ddname, const char *propname,

    int intsz, int numints, void *buf, char *setpoint)

{

	dsl_dir_t *dd;

	const char *tail;

	int err;

	err = dsl_dir_open(ddname, FTAG, &dd, &tail);

	if (err)

		return (err);

	if (tail && tail[0] != '@') {

		dsl_dir_close(dd, FTAG);

		return (ENOENT);

	}

	err = dsl_prop_get_ds(dd, propname, intsz, numints, buf, setpoint);

	dsl_dir_close(dd, FTAG);

	return (err);

}

/*

 * 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));

}

/*

 * Unregister this callback.  Return 0 on success, ENOENT if ddname is

 * invalid, ENOMSG if no matching callback registered.

 */

int

dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,

    dsl_prop_changed_cb_t *callback, void *cbarg)

{

	dsl_dir_t *dd = ds->ds_dir;

	dsl_prop_cb_record_t *cbr;

	mutex_enter(&dd->dd_lock);

	for (cbr = list_head(&dd->dd_prop_cbs);

	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {

		if (cbr->cbr_ds == ds &&

		    cbr->cbr_func == callback &&

		    cbr->cbr_arg == cbarg &&

		    strcmp(cbr->cbr_propname, propname) == 0)

			break;

	}

	if (cbr == NULL) {

		mutex_exit(&dd->dd_lock);

		return (ENOMSG);

	}

	list_remove(&dd->dd_prop_cbs, cbr);

	mutex_exit(&dd->dd_lock);

	kmem_free((void*)cbr->cbr_propname, strlen(cbr->cbr_propname)+1);

	kmem_free(cbr, sizeof (dsl_prop_cb_record_t));

	/* Clean up from dsl_prop_register */

	dsl_dir_close(dd, cbr);

	return (0);

}

/*

 * Return the number of callbacks that are registered for this dataset.

 */

int

dsl_prop_numcb(dsl_dataset_t *ds)

{

	dsl_dir_t *dd = ds->ds_dir;

	dsl_prop_cb_record_t *cbr;

	int num = 0;

	mutex_enter(&dd->dd_lock);

	for (cbr = list_head(&dd->dd_prop_cbs);

	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {

		if (cbr->cbr_ds == ds)

			num++;

	}

	mutex_exit(&dd->dd_lock);

	return (num);

}

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_cb_record_t *cbr;

	objset_t *mos = dp->dp_meta_objset;

	zap_cursor_t zc;

	zap_attribute_t *za;

	int err;

	ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));

	err = dsl_dir_open_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_lookup(mos, dd->dd_phys->dd_props_zapobj, propname,

		    8, 1, &value);

		if (err == 0) {

			dsl_dir_close(dd, FTAG);

			return;

		}

		ASSERT3U(err, ==, ENOENT);

	}

	mutex_enter(&dd->dd_lock);

	for (cbr = list_head(&dd->dd_prop_cbs);

	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {

		if (strcmp(cbr->cbr_propname, propname) == 0) {

			cbr->cbr_func(cbr->cbr_arg, value);

		}

	}

	mutex_exit(&dd->dd_lock);

	za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);

	for (zap_cursor_init(&zc, mos,

	    dd->dd_phys->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_close(dd, FTAG);

}

struct prop_set_arg {

	const char *name;

	int intsz;

	int numints;

	const void *buf;

};

static void

dsl_prop_set_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)

{

	dsl_dir_t *dd = arg1;

	struct prop_set_arg *psa = arg2;

	objset_t *mos = dd->dd_pool->dp_meta_objset;

	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;

	uint64_t intval;

	int isint;

	char valbuf[32];

	char *valstr;

	isint = (dodefault(psa->name, 8, 1, &intval) == 0);

	if (psa->numints == 0) {

		int err = zap_remove(mos, zapobj, psa->name, tx);

		ASSERT(err == 0 || err == ENOENT);

		if (isint) {

			VERIFY(0 == dsl_prop_get_impl(dd->dd_parent,

			    psa->name, 8, 1, &intval, NULL));

		}

	} else {

		VERIFY(0 == zap_update(mos, zapobj, psa->name,

		    psa->intsz, psa->numints, psa->buf, tx));

		if (isint)

			intval = *(uint64_t *)psa->buf;

	}

	if (isint) {

		dsl_prop_changed_notify(dd->dd_pool,

		    dd->dd_object, psa->name, intval, TRUE);

	}

	if (isint) {

		(void) snprintf(valbuf, sizeof (valbuf),

		    "%lld", (longlong_t)intval);

		valstr = valbuf;

	} else {

		valstr = (char *)psa->buf;

	}

	spa_history_internal_log((psa->numints == 0) ? LOG_DS_INHERIT :

	    LOG_DS_PROPSET, dd->dd_pool->dp_spa, tx, cr,

	    "%s=%s dataset = %llu", psa->name, valstr,

	    dd->dd_phys->dd_head_dataset_obj);

}

void

dsl_prop_set_uint64_sync(dsl_dir_t *dd, const char *name, uint64_t val,

    cred_t *cr, dmu_tx_t *tx)

{

	objset_t *mos = dd->dd_pool->dp_meta_objset;

	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;

	ASSERT(dmu_tx_is_syncing(tx));

	VERIFY(0 == zap_update(mos, zapobj, name, sizeof (val), 1, &val, tx));

	dsl_prop_changed_notify(dd->dd_pool, dd->dd_object, name, val, TRUE);

	spa_history_internal_log(LOG_DS_PROPSET, dd->dd_pool->dp_spa, tx, cr,

	    "%s=%llu dataset = %llu", name, (u_longlong_t)val,

	    dd->dd_phys->dd_head_dataset_obj);

}

int

dsl_prop_set_dd(dsl_dir_t *dd, const char *propname,

    int intsz, int numints, const void *buf)

{

	struct prop_set_arg psa;

	psa.name = propname;

	psa.intsz = intsz;

	psa.numints = numints;

	psa.buf = buf;

	return (dsl_sync_task_do(dd->dd_pool,

	    NULL, dsl_prop_set_sync, dd, &psa, 2));

}

int

dsl_prop_set(const char *ddname, const char *propname,

    int intsz, int numints, const void *buf)

{

	dsl_dir_t *dd;

	int err;

	/*

	 * We must do these checks before we get to the syncfunc, since

	 * it can't fail.

	 */

	if (strlen(propname) >= ZAP_MAXNAMELEN)

		return (ENAMETOOLONG);

	if (intsz * numints >= ZAP_MAXVALUELEN)

		return (E2BIG);

	err = dsl_dir_open(ddname, FTAG, &dd, NULL);

	if (err)

		return (err);

	err = dsl_prop_set_dd(dd, propname, intsz, numints, buf);

	dsl_dir_close(dd, FTAG);

	return (err);

}

/*

 * Iterate over all properties for this dataset and return them in an nvlist.

 */

int

{

	dsl_dataset_t *ds = os->os->os_dsl_dataset;

	dsl_dir_t *dd = ds->ds_dir;

	boolean_t snapshot;

	int err = 0;

	dsl_pool_t *dp;

	objset_t *mos;

	snapshot = dsl_dataset_is_snapshot(ds);

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

	dp = dd->dd_pool;

	mos = dp->dp_meta_objset;

	rw_enter(&dp->dp_config_rwlock, RW_READER);

	for (; dd != NULL; dd = dd->dd_parent) {

		char setpoint[MAXNAMELEN];

		zap_cursor_t zc;

		zap_attribute_t za;

		dsl_dir_name(dd, setpoint);

		for (zap_cursor_init(&zc, mos, dd->dd_phys->dd_props_zapobj);

		    (err = zap_cursor_retrieve(&zc, &za)) == 0;

		    zap_cursor_advance(&zc)) {

			nvlist_t *propval;

			zfs_prop_t prop;

			/*

			 * Skip non-inheritable properties.

			 */

			if ((prop = zfs_name_to_prop(za.za_name)) !=

			    ZPROP_INVAL && !zfs_prop_inheritable(prop) &&

			    dd != ds->ds_dir)

				continue;

			if (snapshot &&

			    !zfs_prop_valid_for_type(prop, ZFS_TYPE_SNAPSHOT))

				continue;

			if (nvlist_lookup_nvlist(*nvp, za.za_name,

			    &propval) == 0)

				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,

				    dd->dd_phys->dd_props_zapobj,

				    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);