xref: /freebsd/sys/contrib/openzfs/module/zfs/dsl_prop.c (revision e92ffd9b626833ebdbf2742c8ffddc6cd94b963e)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
24  * Copyright (c) 2013 Martin Matuska. All rights reserved.
25  * Copyright 2019 Joyent, Inc.
26  */
27 
28 #include <sys/zfs_context.h>
29 #include <sys/dmu.h>
30 #include <sys/dmu_objset.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dsl_dataset.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_prop.h>
35 #include <sys/dsl_synctask.h>
36 #include <sys/spa.h>
37 #include <sys/zap.h>
38 #include <sys/fs/zfs.h>
39 
40 #include "zfs_prop.h"
41 
42 #define	ZPROP_INHERIT_SUFFIX "$inherit"
43 #define	ZPROP_RECVD_SUFFIX "$recvd"
44 
45 static int
46 dodefault(zfs_prop_t prop, int intsz, int numints, void *buf)
47 {
48 	/*
49 	 * The setonce properties are read-only, BUT they still
50 	 * have a default value that can be used as the initial
51 	 * value.
52 	 */
53 	if (prop == ZPROP_INVAL ||
54 	    (zfs_prop_readonly(prop) && !zfs_prop_setonce(prop)))
55 		return (SET_ERROR(ENOENT));
56 
57 	if (zfs_prop_get_type(prop) == PROP_TYPE_STRING) {
58 		if (intsz != 1)
59 			return (SET_ERROR(EOVERFLOW));
60 		(void) strncpy(buf, zfs_prop_default_string(prop),
61 		    numints);
62 	} else {
63 		if (intsz != 8 || numints < 1)
64 			return (SET_ERROR(EOVERFLOW));
65 
66 		*(uint64_t *)buf = zfs_prop_default_numeric(prop);
67 	}
68 
69 	return (0);
70 }
71 
72 int
73 dsl_prop_get_dd(dsl_dir_t *dd, const char *propname,
74     int intsz, int numints, void *buf, char *setpoint, boolean_t snapshot)
75 {
76 	int err;
77 	dsl_dir_t *target = dd;
78 	objset_t *mos = dd->dd_pool->dp_meta_objset;
79 	zfs_prop_t prop;
80 	boolean_t inheritable;
81 	boolean_t inheriting = B_FALSE;
82 	char *inheritstr;
83 	char *recvdstr;
84 
85 	ASSERT(dsl_pool_config_held(dd->dd_pool));
86 
87 	if (setpoint)
88 		setpoint[0] = '\0';
89 
90 	prop = zfs_name_to_prop(propname);
91 	inheritable = (prop == ZPROP_INVAL || zfs_prop_inheritable(prop));
92 	inheritstr = kmem_asprintf("%s%s", propname, ZPROP_INHERIT_SUFFIX);
93 	recvdstr = kmem_asprintf("%s%s", propname, ZPROP_RECVD_SUFFIX);
94 
95 	/*
96 	 * Note: dd may become NULL, therefore we shouldn't dereference it
97 	 * after this loop.
98 	 */
99 	for (; dd != NULL; dd = dd->dd_parent) {
100 		if (dd != target || snapshot) {
101 			if (!inheritable) {
102 				err = SET_ERROR(ENOENT);
103 				break;
104 			}
105 			inheriting = B_TRUE;
106 		}
107 
108 		/* Check for a local value. */
109 		err = zap_lookup(mos, dsl_dir_phys(dd)->dd_props_zapobj,
110 		    propname, intsz, numints, buf);
111 		if (err != ENOENT) {
112 			if (setpoint != NULL && err == 0)
113 				dsl_dir_name(dd, setpoint);
114 			break;
115 		}
116 
117 		/*
118 		 * Skip the check for a received value if there is an explicit
119 		 * inheritance entry.
120 		 */
121 		err = zap_contains(mos, dsl_dir_phys(dd)->dd_props_zapobj,
122 		    inheritstr);
123 		if (err != 0 && err != ENOENT)
124 			break;
125 
126 		if (err == ENOENT) {
127 			/* Check for a received value. */
128 			err = zap_lookup(mos, dsl_dir_phys(dd)->dd_props_zapobj,
129 			    recvdstr, intsz, numints, buf);
130 			if (err != ENOENT) {
131 				if (setpoint != NULL && err == 0) {
132 					if (inheriting) {
133 						dsl_dir_name(dd, setpoint);
134 					} else {
135 						(void) strlcpy(setpoint,
136 						    ZPROP_SOURCE_VAL_RECVD,
137 						    MAXNAMELEN);
138 					}
139 				}
140 				break;
141 			}
142 		}
143 
144 		/*
145 		 * If we found an explicit inheritance entry, err is zero even
146 		 * though we haven't yet found the value, so reinitializing err
147 		 * at the end of the loop (instead of at the beginning) ensures
148 		 * that err has a valid post-loop value.
149 		 */
150 		err = SET_ERROR(ENOENT);
151 	}
152 
153 	if (err == ENOENT)
154 		err = dodefault(prop, intsz, numints, buf);
155 
156 	kmem_strfree(inheritstr);
157 	kmem_strfree(recvdstr);
158 
159 	return (err);
160 }
161 
162 int
163 dsl_prop_get_ds(dsl_dataset_t *ds, const char *propname,
164     int intsz, int numints, void *buf, char *setpoint)
165 {
166 	zfs_prop_t prop = zfs_name_to_prop(propname);
167 	boolean_t inheritable;
168 	uint64_t zapobj;
169 
170 	ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
171 	inheritable = (prop == ZPROP_INVAL || zfs_prop_inheritable(prop));
172 	zapobj = dsl_dataset_phys(ds)->ds_props_obj;
173 
174 	if (zapobj != 0) {
175 		objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
176 		int err;
177 
178 		ASSERT(ds->ds_is_snapshot);
179 
180 		/* Check for a local value. */
181 		err = zap_lookup(mos, zapobj, propname, intsz, numints, buf);
182 		if (err != ENOENT) {
183 			if (setpoint != NULL && err == 0)
184 				dsl_dataset_name(ds, setpoint);
185 			return (err);
186 		}
187 
188 		/*
189 		 * Skip the check for a received value if there is an explicit
190 		 * inheritance entry.
191 		 */
192 		if (inheritable) {
193 			char *inheritstr = kmem_asprintf("%s%s", propname,
194 			    ZPROP_INHERIT_SUFFIX);
195 			err = zap_contains(mos, zapobj, inheritstr);
196 			kmem_strfree(inheritstr);
197 			if (err != 0 && err != ENOENT)
198 				return (err);
199 		}
200 
201 		if (err == ENOENT) {
202 			/* Check for a received value. */
203 			char *recvdstr = kmem_asprintf("%s%s", propname,
204 			    ZPROP_RECVD_SUFFIX);
205 			err = zap_lookup(mos, zapobj, recvdstr,
206 			    intsz, numints, buf);
207 			kmem_strfree(recvdstr);
208 			if (err != ENOENT) {
209 				if (setpoint != NULL && err == 0)
210 					(void) strlcpy(setpoint,
211 					    ZPROP_SOURCE_VAL_RECVD,
212 					    MAXNAMELEN);
213 				return (err);
214 			}
215 		}
216 	}
217 
218 	return (dsl_prop_get_dd(ds->ds_dir, propname,
219 	    intsz, numints, buf, setpoint, ds->ds_is_snapshot));
220 }
221 
222 static dsl_prop_record_t *
223 dsl_prop_record_find(dsl_dir_t *dd, const char *propname)
224 {
225 	dsl_prop_record_t *pr = NULL;
226 
227 	ASSERT(MUTEX_HELD(&dd->dd_lock));
228 
229 	for (pr = list_head(&dd->dd_props);
230 	    pr != NULL; pr = list_next(&dd->dd_props, pr)) {
231 		if (strcmp(pr->pr_propname, propname) == 0)
232 			break;
233 	}
234 
235 	return (pr);
236 }
237 
238 static dsl_prop_record_t *
239 dsl_prop_record_create(dsl_dir_t *dd, const char *propname)
240 {
241 	dsl_prop_record_t *pr;
242 
243 	ASSERT(MUTEX_HELD(&dd->dd_lock));
244 
245 	pr = kmem_alloc(sizeof (dsl_prop_record_t), KM_SLEEP);
246 	pr->pr_propname = spa_strdup(propname);
247 	list_create(&pr->pr_cbs, sizeof (dsl_prop_cb_record_t),
248 	    offsetof(dsl_prop_cb_record_t, cbr_pr_node));
249 	list_insert_head(&dd->dd_props, pr);
250 
251 	return (pr);
252 }
253 
254 void
255 dsl_prop_init(dsl_dir_t *dd)
256 {
257 	list_create(&dd->dd_props, sizeof (dsl_prop_record_t),
258 	    offsetof(dsl_prop_record_t, pr_node));
259 }
260 
261 void
262 dsl_prop_fini(dsl_dir_t *dd)
263 {
264 	dsl_prop_record_t *pr;
265 
266 	while ((pr = list_remove_head(&dd->dd_props)) != NULL) {
267 		list_destroy(&pr->pr_cbs);
268 		spa_strfree((char *)pr->pr_propname);
269 		kmem_free(pr, sizeof (dsl_prop_record_t));
270 	}
271 	list_destroy(&dd->dd_props);
272 }
273 
274 /*
275  * Register interest in the named property.  We'll call the callback
276  * once to notify it of the current property value, and again each time
277  * the property changes, until this callback is unregistered.
278  *
279  * Return 0 on success, errno if the prop is not an integer value.
280  */
281 int
282 dsl_prop_register(dsl_dataset_t *ds, const char *propname,
283     dsl_prop_changed_cb_t *callback, void *cbarg)
284 {
285 	dsl_dir_t *dd = ds->ds_dir;
286 	uint64_t value;
287 	dsl_prop_record_t *pr;
288 	dsl_prop_cb_record_t *cbr;
289 	int err;
290 	dsl_pool_t *dp __maybe_unused = dd->dd_pool;
291 
292 	ASSERT(dsl_pool_config_held(dp));
293 
294 	err = dsl_prop_get_int_ds(ds, propname, &value);
295 	if (err != 0)
296 		return (err);
297 
298 	cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);
299 	cbr->cbr_ds = ds;
300 	cbr->cbr_func = callback;
301 	cbr->cbr_arg = cbarg;
302 
303 	mutex_enter(&dd->dd_lock);
304 	pr = dsl_prop_record_find(dd, propname);
305 	if (pr == NULL)
306 		pr = dsl_prop_record_create(dd, propname);
307 	cbr->cbr_pr = pr;
308 	list_insert_head(&pr->pr_cbs, cbr);
309 	list_insert_head(&ds->ds_prop_cbs, cbr);
310 	mutex_exit(&dd->dd_lock);
311 
312 	cbr->cbr_func(cbr->cbr_arg, value);
313 	return (0);
314 }
315 
316 int
317 dsl_prop_get(const char *dsname, const char *propname,
318     int intsz, int numints, void *buf, char *setpoint)
319 {
320 	objset_t *os;
321 	int error;
322 
323 	error = dmu_objset_hold(dsname, FTAG, &os);
324 	if (error != 0)
325 		return (error);
326 
327 	error = dsl_prop_get_ds(dmu_objset_ds(os), propname,
328 	    intsz, numints, buf, setpoint);
329 
330 	dmu_objset_rele(os, FTAG);
331 	return (error);
332 }
333 
334 /*
335  * Get the current property value.  It may have changed by the time this
336  * function returns, so it is NOT safe to follow up with
337  * dsl_prop_register() and assume that the value has not changed in
338  * between.
339  *
340  * Return 0 on success, ENOENT if ddname is invalid.
341  */
342 int
343 dsl_prop_get_integer(const char *ddname, const char *propname,
344     uint64_t *valuep, char *setpoint)
345 {
346 	return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
347 }
348 
349 int
350 dsl_prop_get_int_ds(dsl_dataset_t *ds, const char *propname,
351     uint64_t *valuep)
352 {
353 	return (dsl_prop_get_ds(ds, propname, 8, 1, valuep, NULL));
354 }
355 
356 /*
357  * Predict the effective value of the given special property if it were set with
358  * the given value and source. This is not a general purpose function. It exists
359  * only to handle the special requirements of the quota and reservation
360  * properties. The fact that these properties are non-inheritable greatly
361  * simplifies the prediction logic.
362  *
363  * Returns 0 on success, a positive error code on failure, or -1 if called with
364  * a property not handled by this function.
365  */
366 int
367 dsl_prop_predict(dsl_dir_t *dd, const char *propname,
368     zprop_source_t source, uint64_t value, uint64_t *newvalp)
369 {
370 	zfs_prop_t prop = zfs_name_to_prop(propname);
371 	objset_t *mos;
372 	uint64_t zapobj;
373 	uint64_t version;
374 	char *recvdstr;
375 	int err = 0;
376 
377 	switch (prop) {
378 	case ZFS_PROP_QUOTA:
379 	case ZFS_PROP_RESERVATION:
380 	case ZFS_PROP_REFQUOTA:
381 	case ZFS_PROP_REFRESERVATION:
382 		break;
383 	default:
384 		return (-1);
385 	}
386 
387 	mos = dd->dd_pool->dp_meta_objset;
388 	zapobj = dsl_dir_phys(dd)->dd_props_zapobj;
389 	recvdstr = kmem_asprintf("%s%s", propname, ZPROP_RECVD_SUFFIX);
390 
391 	version = spa_version(dd->dd_pool->dp_spa);
392 	if (version < SPA_VERSION_RECVD_PROPS) {
393 		if (source & ZPROP_SRC_NONE)
394 			source = ZPROP_SRC_NONE;
395 		else if (source & ZPROP_SRC_RECEIVED)
396 			source = ZPROP_SRC_LOCAL;
397 	}
398 
399 	switch ((int)source) {
400 	case ZPROP_SRC_NONE:
401 		/* Revert to the received value, if any. */
402 		err = zap_lookup(mos, zapobj, recvdstr, 8, 1, newvalp);
403 		if (err == ENOENT)
404 			*newvalp = 0;
405 		break;
406 	case ZPROP_SRC_LOCAL:
407 		*newvalp = value;
408 		break;
409 	case ZPROP_SRC_RECEIVED:
410 		/*
411 		 * If there's no local setting, then the new received value will
412 		 * be the effective value.
413 		 */
414 		err = zap_lookup(mos, zapobj, propname, 8, 1, newvalp);
415 		if (err == ENOENT)
416 			*newvalp = value;
417 		break;
418 	case (ZPROP_SRC_NONE | ZPROP_SRC_RECEIVED):
419 		/*
420 		 * We're clearing the received value, so the local setting (if
421 		 * it exists) remains the effective value.
422 		 */
423 		err = zap_lookup(mos, zapobj, propname, 8, 1, newvalp);
424 		if (err == ENOENT)
425 			*newvalp = 0;
426 		break;
427 	default:
428 		panic("unexpected property source: %d", source);
429 	}
430 
431 	kmem_strfree(recvdstr);
432 
433 	if (err == ENOENT)
434 		return (0);
435 
436 	return (err);
437 }
438 
439 /*
440  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
441  * invalid, or ENOMSG if no matching callback registered.
442  *
443  * NOTE: This function is no longer used internally but has been preserved
444  * to prevent breaking external consumers (Lustre, etc).
445  */
446 int
447 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,
448     dsl_prop_changed_cb_t *callback, void *cbarg)
449 {
450 	dsl_dir_t *dd = ds->ds_dir;
451 	dsl_prop_cb_record_t *cbr;
452 
453 	mutex_enter(&dd->dd_lock);
454 	for (cbr = list_head(&ds->ds_prop_cbs);
455 	    cbr; cbr = list_next(&ds->ds_prop_cbs, cbr)) {
456 		if (cbr->cbr_ds == ds &&
457 		    cbr->cbr_func == callback &&
458 		    cbr->cbr_arg == cbarg &&
459 		    strcmp(cbr->cbr_pr->pr_propname, propname) == 0)
460 			break;
461 	}
462 
463 	if (cbr == NULL) {
464 		mutex_exit(&dd->dd_lock);
465 		return (SET_ERROR(ENOMSG));
466 	}
467 
468 	list_remove(&ds->ds_prop_cbs, cbr);
469 	list_remove(&cbr->cbr_pr->pr_cbs, cbr);
470 	mutex_exit(&dd->dd_lock);
471 	kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
472 
473 	return (0);
474 }
475 
476 /*
477  * Unregister all callbacks that are registered with the
478  * given callback argument.
479  */
480 void
481 dsl_prop_unregister_all(dsl_dataset_t *ds, void *cbarg)
482 {
483 	dsl_prop_cb_record_t *cbr, *next_cbr;
484 
485 	dsl_dir_t *dd = ds->ds_dir;
486 
487 	mutex_enter(&dd->dd_lock);
488 	next_cbr = list_head(&ds->ds_prop_cbs);
489 	while (next_cbr != NULL) {
490 		cbr = next_cbr;
491 		next_cbr = list_next(&ds->ds_prop_cbs, cbr);
492 		if (cbr->cbr_arg == cbarg) {
493 			list_remove(&ds->ds_prop_cbs, cbr);
494 			list_remove(&cbr->cbr_pr->pr_cbs, cbr);
495 			kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
496 		}
497 	}
498 	mutex_exit(&dd->dd_lock);
499 }
500 
501 boolean_t
502 dsl_prop_hascb(dsl_dataset_t *ds)
503 {
504 	return (!list_is_empty(&ds->ds_prop_cbs));
505 }
506 
507 static int
508 dsl_prop_notify_all_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
509 {
510 	(void) arg;
511 	dsl_dir_t *dd = ds->ds_dir;
512 	dsl_prop_record_t *pr;
513 	dsl_prop_cb_record_t *cbr;
514 
515 	mutex_enter(&dd->dd_lock);
516 	for (pr = list_head(&dd->dd_props);
517 	    pr; pr = list_next(&dd->dd_props, pr)) {
518 		for (cbr = list_head(&pr->pr_cbs); cbr;
519 		    cbr = list_next(&pr->pr_cbs, cbr)) {
520 			uint64_t value;
521 
522 			/*
523 			 * Callback entries do not have holds on their
524 			 * datasets so that datasets with registered
525 			 * callbacks are still eligible for eviction.
526 			 * Unlike operations to update properties on a
527 			 * single dataset, we are performing a recursive
528 			 * descent of related head datasets.  The caller
529 			 * of this function only has a dataset hold on
530 			 * the passed in head dataset, not the snapshots
531 			 * associated with this dataset.  Without a hold,
532 			 * the dataset pointer within callback records
533 			 * for snapshots can be invalidated by eviction
534 			 * at any time.
535 			 *
536 			 * Use dsl_dataset_try_add_ref() to verify
537 			 * that the dataset for a snapshot has not
538 			 * begun eviction processing and to prevent
539 			 * eviction from occurring for the duration of
540 			 * the callback.  If the hold attempt fails,
541 			 * this object is already being evicted and the
542 			 * callback can be safely ignored.
543 			 */
544 			if (ds != cbr->cbr_ds &&
545 			    !dsl_dataset_try_add_ref(dp, cbr->cbr_ds, FTAG))
546 				continue;
547 
548 			if (dsl_prop_get_ds(cbr->cbr_ds,
549 			    cbr->cbr_pr->pr_propname, sizeof (value), 1,
550 			    &value, NULL) == 0)
551 				cbr->cbr_func(cbr->cbr_arg, value);
552 
553 			if (ds != cbr->cbr_ds)
554 				dsl_dataset_rele(cbr->cbr_ds, FTAG);
555 		}
556 	}
557 	mutex_exit(&dd->dd_lock);
558 
559 	return (0);
560 }
561 
562 /*
563  * Update all property values for ddobj & its descendants.  This is used
564  * when renaming the dir.
565  */
566 void
567 dsl_prop_notify_all(dsl_dir_t *dd)
568 {
569 	dsl_pool_t *dp = dd->dd_pool;
570 	ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
571 	(void) dmu_objset_find_dp(dp, dd->dd_object, dsl_prop_notify_all_cb,
572 	    NULL, DS_FIND_CHILDREN);
573 }
574 
575 static void
576 dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
577     const char *propname, uint64_t value, int first)
578 {
579 	dsl_dir_t *dd;
580 	dsl_prop_record_t *pr;
581 	dsl_prop_cb_record_t *cbr;
582 	objset_t *mos = dp->dp_meta_objset;
583 	zap_cursor_t zc;
584 	zap_attribute_t *za;
585 	int err;
586 
587 	ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
588 	err = dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd);
589 	if (err)
590 		return;
591 
592 	if (!first) {
593 		/*
594 		 * If the prop is set here, then this change is not
595 		 * being inherited here or below; stop the recursion.
596 		 */
597 		err = zap_contains(mos, dsl_dir_phys(dd)->dd_props_zapobj,
598 		    propname);
599 		if (err == 0) {
600 			dsl_dir_rele(dd, FTAG);
601 			return;
602 		}
603 		ASSERT3U(err, ==, ENOENT);
604 	}
605 
606 	mutex_enter(&dd->dd_lock);
607 	pr = dsl_prop_record_find(dd, propname);
608 	if (pr != NULL) {
609 		for (cbr = list_head(&pr->pr_cbs); cbr;
610 		    cbr = list_next(&pr->pr_cbs, cbr)) {
611 			uint64_t propobj;
612 
613 			/*
614 			 * cbr->cbr_ds may be invalidated due to eviction,
615 			 * requiring the use of dsl_dataset_try_add_ref().
616 			 * See comment block in dsl_prop_notify_all_cb()
617 			 * for details.
618 			 */
619 			if (!dsl_dataset_try_add_ref(dp, cbr->cbr_ds, FTAG))
620 				continue;
621 
622 			propobj = dsl_dataset_phys(cbr->cbr_ds)->ds_props_obj;
623 
624 			/*
625 			 * If the property is not set on this ds, then it is
626 			 * inherited here; call the callback.
627 			 */
628 			if (propobj == 0 ||
629 			    zap_contains(mos, propobj, propname) != 0)
630 				cbr->cbr_func(cbr->cbr_arg, value);
631 
632 			dsl_dataset_rele(cbr->cbr_ds, FTAG);
633 		}
634 	}
635 	mutex_exit(&dd->dd_lock);
636 
637 	za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
638 	for (zap_cursor_init(&zc, mos,
639 	    dsl_dir_phys(dd)->dd_child_dir_zapobj);
640 	    zap_cursor_retrieve(&zc, za) == 0;
641 	    zap_cursor_advance(&zc)) {
642 		dsl_prop_changed_notify(dp, za->za_first_integer,
643 		    propname, value, FALSE);
644 	}
645 	kmem_free(za, sizeof (zap_attribute_t));
646 	zap_cursor_fini(&zc);
647 	dsl_dir_rele(dd, FTAG);
648 }
649 
650 void
651 dsl_prop_set_sync_impl(dsl_dataset_t *ds, const char *propname,
652     zprop_source_t source, int intsz, int numints, const void *value,
653     dmu_tx_t *tx)
654 {
655 	objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
656 	uint64_t zapobj, intval, dummy, count;
657 	int isint;
658 	char valbuf[32];
659 	const char *valstr = NULL;
660 	char *inheritstr;
661 	char *recvdstr;
662 	char *tbuf = NULL;
663 	int err;
664 	uint64_t version = spa_version(ds->ds_dir->dd_pool->dp_spa);
665 
666 	isint = (dodefault(zfs_name_to_prop(propname), 8, 1, &intval) == 0);
667 
668 	if (ds->ds_is_snapshot) {
669 		ASSERT(version >= SPA_VERSION_SNAP_PROPS);
670 		if (dsl_dataset_phys(ds)->ds_props_obj == 0 &&
671 		    (source & ZPROP_SRC_NONE) == 0) {
672 			dmu_buf_will_dirty(ds->ds_dbuf, tx);
673 			dsl_dataset_phys(ds)->ds_props_obj =
674 			    zap_create(mos,
675 			    DMU_OT_DSL_PROPS, DMU_OT_NONE, 0, tx);
676 		}
677 		zapobj = dsl_dataset_phys(ds)->ds_props_obj;
678 	} else {
679 		zapobj = dsl_dir_phys(ds->ds_dir)->dd_props_zapobj;
680 	}
681 
682 	/* If we are removing objects from a non-existent ZAP just return */
683 	if (zapobj == 0)
684 		return;
685 
686 	if (version < SPA_VERSION_RECVD_PROPS) {
687 		if (source & ZPROP_SRC_NONE)
688 			source = ZPROP_SRC_NONE;
689 		else if (source & ZPROP_SRC_RECEIVED)
690 			source = ZPROP_SRC_LOCAL;
691 	}
692 
693 	inheritstr = kmem_asprintf("%s%s", propname, ZPROP_INHERIT_SUFFIX);
694 	recvdstr = kmem_asprintf("%s%s", propname, ZPROP_RECVD_SUFFIX);
695 
696 	switch ((int)source) {
697 	case ZPROP_SRC_NONE:
698 		/*
699 		 * revert to received value, if any (inherit -S)
700 		 * - remove propname
701 		 * - remove propname$inherit
702 		 */
703 		err = zap_remove(mos, zapobj, propname, tx);
704 		ASSERT(err == 0 || err == ENOENT);
705 		err = zap_remove(mos, zapobj, inheritstr, tx);
706 		ASSERT(err == 0 || err == ENOENT);
707 		break;
708 	case ZPROP_SRC_LOCAL:
709 		/*
710 		 * remove propname$inherit
711 		 * set propname -> value
712 		 */
713 		err = zap_remove(mos, zapobj, inheritstr, tx);
714 		ASSERT(err == 0 || err == ENOENT);
715 		VERIFY0(zap_update(mos, zapobj, propname,
716 		    intsz, numints, value, tx));
717 		break;
718 	case ZPROP_SRC_INHERITED:
719 		/*
720 		 * explicitly inherit
721 		 * - remove propname
722 		 * - set propname$inherit
723 		 */
724 		err = zap_remove(mos, zapobj, propname, tx);
725 		ASSERT(err == 0 || err == ENOENT);
726 		if (version >= SPA_VERSION_RECVD_PROPS &&
727 		    dsl_prop_get_int_ds(ds, ZPROP_HAS_RECVD, &dummy) == 0) {
728 			dummy = 0;
729 			VERIFY0(zap_update(mos, zapobj, inheritstr,
730 			    8, 1, &dummy, tx));
731 		}
732 		break;
733 	case ZPROP_SRC_RECEIVED:
734 		/*
735 		 * set propname$recvd -> value
736 		 */
737 		err = zap_update(mos, zapobj, recvdstr,
738 		    intsz, numints, value, tx);
739 		ASSERT(err == 0);
740 		break;
741 	case (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED):
742 		/*
743 		 * clear local and received settings
744 		 * - remove propname
745 		 * - remove propname$inherit
746 		 * - remove propname$recvd
747 		 */
748 		err = zap_remove(mos, zapobj, propname, tx);
749 		ASSERT(err == 0 || err == ENOENT);
750 		err = zap_remove(mos, zapobj, inheritstr, tx);
751 		ASSERT(err == 0 || err == ENOENT);
752 		fallthrough;
753 	case (ZPROP_SRC_NONE | ZPROP_SRC_RECEIVED):
754 		/*
755 		 * remove propname$recvd
756 		 */
757 		err = zap_remove(mos, zapobj, recvdstr, tx);
758 		ASSERT(err == 0 || err == ENOENT);
759 		break;
760 	default:
761 		cmn_err(CE_PANIC, "unexpected property source: %d", source);
762 	}
763 
764 	kmem_strfree(inheritstr);
765 	kmem_strfree(recvdstr);
766 
767 	/*
768 	 * If we are left with an empty snap zap we can destroy it.
769 	 * This will prevent unnecessary calls to zap_lookup() in
770 	 * the "zfs list" and "zfs get" code paths.
771 	 */
772 	if (ds->ds_is_snapshot &&
773 	    zap_count(mos, zapobj, &count) == 0 && count == 0) {
774 		dmu_buf_will_dirty(ds->ds_dbuf, tx);
775 		dsl_dataset_phys(ds)->ds_props_obj = 0;
776 		zap_destroy(mos, zapobj, tx);
777 	}
778 
779 	if (isint) {
780 		VERIFY0(dsl_prop_get_int_ds(ds, propname, &intval));
781 
782 		if (ds->ds_is_snapshot) {
783 			dsl_prop_cb_record_t *cbr;
784 			/*
785 			 * It's a snapshot; nothing can inherit this
786 			 * property, so just look for callbacks on this
787 			 * ds here.
788 			 */
789 			mutex_enter(&ds->ds_dir->dd_lock);
790 			for (cbr = list_head(&ds->ds_prop_cbs); cbr;
791 			    cbr = list_next(&ds->ds_prop_cbs, cbr)) {
792 				if (strcmp(cbr->cbr_pr->pr_propname,
793 				    propname) == 0)
794 					cbr->cbr_func(cbr->cbr_arg, intval);
795 			}
796 			mutex_exit(&ds->ds_dir->dd_lock);
797 		} else {
798 			dsl_prop_changed_notify(ds->ds_dir->dd_pool,
799 			    ds->ds_dir->dd_object, propname, intval, TRUE);
800 		}
801 
802 		(void) snprintf(valbuf, sizeof (valbuf),
803 		    "%lld", (longlong_t)intval);
804 		valstr = valbuf;
805 	} else {
806 		if (source == ZPROP_SRC_LOCAL) {
807 			valstr = value;
808 		} else {
809 			tbuf = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
810 			if (dsl_prop_get_ds(ds, propname, 1,
811 			    ZAP_MAXVALUELEN, tbuf, NULL) == 0)
812 				valstr = tbuf;
813 		}
814 	}
815 
816 	spa_history_log_internal_ds(ds, (source == ZPROP_SRC_NONE ||
817 	    source == ZPROP_SRC_INHERITED) ? "inherit" : "set", tx,
818 	    "%s=%s", propname, (valstr == NULL ? "" : valstr));
819 
820 	if (tbuf != NULL)
821 		kmem_free(tbuf, ZAP_MAXVALUELEN);
822 }
823 
824 int
825 dsl_prop_set_int(const char *dsname, const char *propname,
826     zprop_source_t source, uint64_t value)
827 {
828 	nvlist_t *nvl = fnvlist_alloc();
829 	int error;
830 
831 	fnvlist_add_uint64(nvl, propname, value);
832 	error = dsl_props_set(dsname, source, nvl);
833 	fnvlist_free(nvl);
834 	return (error);
835 }
836 
837 int
838 dsl_prop_set_string(const char *dsname, const char *propname,
839     zprop_source_t source, const char *value)
840 {
841 	nvlist_t *nvl = fnvlist_alloc();
842 	int error;
843 
844 	fnvlist_add_string(nvl, propname, value);
845 	error = dsl_props_set(dsname, source, nvl);
846 	fnvlist_free(nvl);
847 	return (error);
848 }
849 
850 int
851 dsl_prop_inherit(const char *dsname, const char *propname,
852     zprop_source_t source)
853 {
854 	nvlist_t *nvl = fnvlist_alloc();
855 	int error;
856 
857 	fnvlist_add_boolean(nvl, propname);
858 	error = dsl_props_set(dsname, source, nvl);
859 	fnvlist_free(nvl);
860 	return (error);
861 }
862 
863 int
864 dsl_props_set_check(void *arg, dmu_tx_t *tx)
865 {
866 	dsl_props_set_arg_t *dpsa = arg;
867 	dsl_pool_t *dp = dmu_tx_pool(tx);
868 	dsl_dataset_t *ds;
869 	uint64_t version;
870 	nvpair_t *elem = NULL;
871 	int err;
872 
873 	err = dsl_dataset_hold(dp, dpsa->dpsa_dsname, FTAG, &ds);
874 	if (err != 0)
875 		return (err);
876 
877 	version = spa_version(ds->ds_dir->dd_pool->dp_spa);
878 	while ((elem = nvlist_next_nvpair(dpsa->dpsa_props, elem)) != NULL) {
879 		if (strlen(nvpair_name(elem)) >= ZAP_MAXNAMELEN) {
880 			dsl_dataset_rele(ds, FTAG);
881 			return (SET_ERROR(ENAMETOOLONG));
882 		}
883 		if (nvpair_type(elem) == DATA_TYPE_STRING) {
884 			char *valstr = fnvpair_value_string(elem);
885 			if (strlen(valstr) >= (version <
886 			    SPA_VERSION_STMF_PROP ?
887 			    ZAP_OLDMAXVALUELEN : ZAP_MAXVALUELEN)) {
888 				dsl_dataset_rele(ds, FTAG);
889 				return (SET_ERROR(E2BIG));
890 			}
891 		}
892 	}
893 
894 	if (ds->ds_is_snapshot && version < SPA_VERSION_SNAP_PROPS) {
895 		dsl_dataset_rele(ds, FTAG);
896 		return (SET_ERROR(ENOTSUP));
897 	}
898 	dsl_dataset_rele(ds, FTAG);
899 	return (0);
900 }
901 
902 void
903 dsl_props_set_sync_impl(dsl_dataset_t *ds, zprop_source_t source,
904     nvlist_t *props, dmu_tx_t *tx)
905 {
906 	nvpair_t *elem = NULL;
907 
908 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
909 		nvpair_t *pair = elem;
910 		const char *name = nvpair_name(pair);
911 
912 		if (nvpair_type(pair) == DATA_TYPE_NVLIST) {
913 			/*
914 			 * This usually happens when we reuse the nvlist_t data
915 			 * returned by the counterpart dsl_prop_get_all_impl().
916 			 * For instance we do this to restore the original
917 			 * received properties when an error occurs in the
918 			 * zfs_ioc_recv() codepath.
919 			 */
920 			nvlist_t *attrs = fnvpair_value_nvlist(pair);
921 			pair = fnvlist_lookup_nvpair(attrs, ZPROP_VALUE);
922 		}
923 
924 		if (nvpair_type(pair) == DATA_TYPE_STRING) {
925 			const char *value = fnvpair_value_string(pair);
926 			dsl_prop_set_sync_impl(ds, name,
927 			    source, 1, strlen(value) + 1, value, tx);
928 		} else if (nvpair_type(pair) == DATA_TYPE_UINT64) {
929 			uint64_t intval = fnvpair_value_uint64(pair);
930 			dsl_prop_set_sync_impl(ds, name,
931 			    source, sizeof (intval), 1, &intval, tx);
932 		} else if (nvpair_type(pair) == DATA_TYPE_BOOLEAN) {
933 			dsl_prop_set_sync_impl(ds, name,
934 			    source, 0, 0, NULL, tx);
935 		} else {
936 			panic("invalid nvpair type");
937 		}
938 	}
939 }
940 
941 void
942 dsl_props_set_sync(void *arg, dmu_tx_t *tx)
943 {
944 	dsl_props_set_arg_t *dpsa = arg;
945 	dsl_pool_t *dp = dmu_tx_pool(tx);
946 	dsl_dataset_t *ds;
947 
948 	VERIFY0(dsl_dataset_hold(dp, dpsa->dpsa_dsname, FTAG, &ds));
949 	dsl_props_set_sync_impl(ds, dpsa->dpsa_source, dpsa->dpsa_props, tx);
950 	dsl_dataset_rele(ds, FTAG);
951 }
952 
953 /*
954  * All-or-nothing; if any prop can't be set, nothing will be modified.
955  */
956 int
957 dsl_props_set(const char *dsname, zprop_source_t source, nvlist_t *props)
958 {
959 	dsl_props_set_arg_t dpsa;
960 	int nblks = 0;
961 
962 	dpsa.dpsa_dsname = dsname;
963 	dpsa.dpsa_source = source;
964 	dpsa.dpsa_props = props;
965 
966 	/*
967 	 * If the source includes NONE, then we will only be removing entries
968 	 * from the ZAP object.  In that case don't check for ENOSPC.
969 	 */
970 	if ((source & ZPROP_SRC_NONE) == 0)
971 		nblks = 2 * fnvlist_num_pairs(props);
972 
973 	return (dsl_sync_task(dsname, dsl_props_set_check, dsl_props_set_sync,
974 	    &dpsa, nblks, ZFS_SPACE_CHECK_RESERVED));
975 }
976 
977 typedef enum dsl_prop_getflags {
978 	DSL_PROP_GET_INHERITING = 0x1,	/* searching parent of target ds */
979 	DSL_PROP_GET_SNAPSHOT = 0x2,	/* snapshot dataset */
980 	DSL_PROP_GET_LOCAL = 0x4,	/* local properties */
981 	DSL_PROP_GET_RECEIVED = 0x8,	/* received properties */
982 } dsl_prop_getflags_t;
983 
984 static int
985 dsl_prop_get_all_impl(objset_t *mos, uint64_t propobj,
986     const char *setpoint, dsl_prop_getflags_t flags, nvlist_t *nv)
987 {
988 	zap_cursor_t zc;
989 	zap_attribute_t za;
990 	int err = 0;
991 
992 	for (zap_cursor_init(&zc, mos, propobj);
993 	    (err = zap_cursor_retrieve(&zc, &za)) == 0;
994 	    zap_cursor_advance(&zc)) {
995 		nvlist_t *propval;
996 		zfs_prop_t prop;
997 		char buf[ZAP_MAXNAMELEN];
998 		char *valstr;
999 		const char *suffix;
1000 		const char *propname;
1001 		const char *source;
1002 
1003 		suffix = strchr(za.za_name, '$');
1004 
1005 		if (suffix == NULL) {
1006 			/*
1007 			 * Skip local properties if we only want received
1008 			 * properties.
1009 			 */
1010 			if (flags & DSL_PROP_GET_RECEIVED)
1011 				continue;
1012 
1013 			propname = za.za_name;
1014 			source = setpoint;
1015 		} else if (strcmp(suffix, ZPROP_INHERIT_SUFFIX) == 0) {
1016 			/* Skip explicitly inherited entries. */
1017 			continue;
1018 		} else if (strcmp(suffix, ZPROP_RECVD_SUFFIX) == 0) {
1019 			if (flags & DSL_PROP_GET_LOCAL)
1020 				continue;
1021 
1022 			(void) strncpy(buf, za.za_name, (suffix - za.za_name));
1023 			buf[suffix - za.za_name] = '\0';
1024 			propname = buf;
1025 
1026 			if (!(flags & DSL_PROP_GET_RECEIVED)) {
1027 				/* Skip if locally overridden. */
1028 				err = zap_contains(mos, propobj, propname);
1029 				if (err == 0)
1030 					continue;
1031 				if (err != ENOENT)
1032 					break;
1033 
1034 				/* Skip if explicitly inherited. */
1035 				valstr = kmem_asprintf("%s%s", propname,
1036 				    ZPROP_INHERIT_SUFFIX);
1037 				err = zap_contains(mos, propobj, valstr);
1038 				kmem_strfree(valstr);
1039 				if (err == 0)
1040 					continue;
1041 				if (err != ENOENT)
1042 					break;
1043 			}
1044 
1045 			source = ((flags & DSL_PROP_GET_INHERITING) ?
1046 			    setpoint : ZPROP_SOURCE_VAL_RECVD);
1047 		} else {
1048 			/*
1049 			 * For backward compatibility, skip suffixes we don't
1050 			 * recognize.
1051 			 */
1052 			continue;
1053 		}
1054 
1055 		prop = zfs_name_to_prop(propname);
1056 
1057 		/* Skip non-inheritable properties. */
1058 		if ((flags & DSL_PROP_GET_INHERITING) && prop != ZPROP_INVAL &&
1059 		    !zfs_prop_inheritable(prop))
1060 			continue;
1061 
1062 		/* Skip properties not valid for this type. */
1063 		if ((flags & DSL_PROP_GET_SNAPSHOT) && prop != ZPROP_INVAL &&
1064 		    !zfs_prop_valid_for_type(prop, ZFS_TYPE_SNAPSHOT, B_FALSE))
1065 			continue;
1066 
1067 		/* Skip properties already defined. */
1068 		if (nvlist_exists(nv, propname))
1069 			continue;
1070 
1071 		VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1072 		if (za.za_integer_length == 1) {
1073 			/*
1074 			 * String property
1075 			 */
1076 			char *tmp = kmem_alloc(za.za_num_integers,
1077 			    KM_SLEEP);
1078 			err = zap_lookup(mos, propobj,
1079 			    za.za_name, 1, za.za_num_integers, tmp);
1080 			if (err != 0) {
1081 				kmem_free(tmp, za.za_num_integers);
1082 				break;
1083 			}
1084 			VERIFY(nvlist_add_string(propval, ZPROP_VALUE,
1085 			    tmp) == 0);
1086 			kmem_free(tmp, za.za_num_integers);
1087 		} else {
1088 			/*
1089 			 * Integer property
1090 			 */
1091 			ASSERT(za.za_integer_length == 8);
1092 			(void) nvlist_add_uint64(propval, ZPROP_VALUE,
1093 			    za.za_first_integer);
1094 		}
1095 
1096 		VERIFY(nvlist_add_string(propval, ZPROP_SOURCE, source) == 0);
1097 		VERIFY(nvlist_add_nvlist(nv, propname, propval) == 0);
1098 		nvlist_free(propval);
1099 	}
1100 	zap_cursor_fini(&zc);
1101 	if (err == ENOENT)
1102 		err = 0;
1103 	return (err);
1104 }
1105 
1106 /*
1107  * Iterate over all properties for this dataset and return them in an nvlist.
1108  */
1109 static int
1110 dsl_prop_get_all_ds(dsl_dataset_t *ds, nvlist_t **nvp,
1111     dsl_prop_getflags_t flags)
1112 {
1113 	dsl_dir_t *dd = ds->ds_dir;
1114 	dsl_pool_t *dp = dd->dd_pool;
1115 	objset_t *mos = dp->dp_meta_objset;
1116 	int err = 0;
1117 	char setpoint[ZFS_MAX_DATASET_NAME_LEN];
1118 
1119 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1120 
1121 	if (ds->ds_is_snapshot)
1122 		flags |= DSL_PROP_GET_SNAPSHOT;
1123 
1124 	ASSERT(dsl_pool_config_held(dp));
1125 
1126 	if (dsl_dataset_phys(ds)->ds_props_obj != 0) {
1127 		ASSERT(flags & DSL_PROP_GET_SNAPSHOT);
1128 		dsl_dataset_name(ds, setpoint);
1129 		err = dsl_prop_get_all_impl(mos,
1130 		    dsl_dataset_phys(ds)->ds_props_obj, setpoint, flags, *nvp);
1131 		if (err)
1132 			goto out;
1133 	}
1134 
1135 	for (; dd != NULL; dd = dd->dd_parent) {
1136 		if (dd != ds->ds_dir || (flags & DSL_PROP_GET_SNAPSHOT)) {
1137 			if (flags & (DSL_PROP_GET_LOCAL |
1138 			    DSL_PROP_GET_RECEIVED))
1139 				break;
1140 			flags |= DSL_PROP_GET_INHERITING;
1141 		}
1142 		dsl_dir_name(dd, setpoint);
1143 		err = dsl_prop_get_all_impl(mos,
1144 		    dsl_dir_phys(dd)->dd_props_zapobj, setpoint, flags, *nvp);
1145 		if (err)
1146 			break;
1147 	}
1148 
1149 out:
1150 	if (err) {
1151 		nvlist_free(*nvp);
1152 		*nvp = NULL;
1153 	}
1154 	return (err);
1155 }
1156 
1157 boolean_t
1158 dsl_prop_get_hasrecvd(const char *dsname)
1159 {
1160 	uint64_t dummy;
1161 
1162 	return (0 ==
1163 	    dsl_prop_get_integer(dsname, ZPROP_HAS_RECVD, &dummy, NULL));
1164 }
1165 
1166 static int
1167 dsl_prop_set_hasrecvd_impl(const char *dsname, zprop_source_t source)
1168 {
1169 	uint64_t version;
1170 	spa_t *spa;
1171 	int error = 0;
1172 
1173 	VERIFY0(spa_open(dsname, &spa, FTAG));
1174 	version = spa_version(spa);
1175 	spa_close(spa, FTAG);
1176 
1177 	if (version >= SPA_VERSION_RECVD_PROPS)
1178 		error = dsl_prop_set_int(dsname, ZPROP_HAS_RECVD, source, 0);
1179 	return (error);
1180 }
1181 
1182 /*
1183  * Call after successfully receiving properties to ensure that only the first
1184  * receive on or after SPA_VERSION_RECVD_PROPS blows away local properties.
1185  */
1186 int
1187 dsl_prop_set_hasrecvd(const char *dsname)
1188 {
1189 	int error = 0;
1190 	if (!dsl_prop_get_hasrecvd(dsname))
1191 		error = dsl_prop_set_hasrecvd_impl(dsname, ZPROP_SRC_LOCAL);
1192 	return (error);
1193 }
1194 
1195 void
1196 dsl_prop_unset_hasrecvd(const char *dsname)
1197 {
1198 	VERIFY0(dsl_prop_set_hasrecvd_impl(dsname, ZPROP_SRC_NONE));
1199 }
1200 
1201 int
1202 dsl_prop_get_all(objset_t *os, nvlist_t **nvp)
1203 {
1204 	return (dsl_prop_get_all_ds(os->os_dsl_dataset, nvp, 0));
1205 }
1206 
1207 int
1208 dsl_prop_get_received(const char *dsname, nvlist_t **nvp)
1209 {
1210 	objset_t *os;
1211 	int error;
1212 
1213 	/*
1214 	 * Received properties are not distinguishable from local properties
1215 	 * until the dataset has received properties on or after
1216 	 * SPA_VERSION_RECVD_PROPS.
1217 	 */
1218 	dsl_prop_getflags_t flags = (dsl_prop_get_hasrecvd(dsname) ?
1219 	    DSL_PROP_GET_RECEIVED : DSL_PROP_GET_LOCAL);
1220 
1221 	error = dmu_objset_hold(dsname, FTAG, &os);
1222 	if (error != 0)
1223 		return (error);
1224 	error = dsl_prop_get_all_ds(os->os_dsl_dataset, nvp, flags);
1225 	dmu_objset_rele(os, FTAG);
1226 	return (error);
1227 }
1228 
1229 void
1230 dsl_prop_nvlist_add_uint64(nvlist_t *nv, zfs_prop_t prop, uint64_t value)
1231 {
1232 	nvlist_t *propval;
1233 	const char *propname = zfs_prop_to_name(prop);
1234 	uint64_t default_value;
1235 
1236 	if (nvlist_lookup_nvlist(nv, propname, &propval) == 0) {
1237 		VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, value) == 0);
1238 		return;
1239 	}
1240 
1241 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1242 	VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, value) == 0);
1243 	/* Indicate the default source if we can. */
1244 	if (dodefault(prop, 8, 1, &default_value) == 0 &&
1245 	    value == default_value) {
1246 		VERIFY(nvlist_add_string(propval, ZPROP_SOURCE, "") == 0);
1247 	}
1248 	VERIFY(nvlist_add_nvlist(nv, propname, propval) == 0);
1249 	nvlist_free(propval);
1250 }
1251 
1252 void
1253 dsl_prop_nvlist_add_string(nvlist_t *nv, zfs_prop_t prop, const char *value)
1254 {
1255 	nvlist_t *propval;
1256 	const char *propname = zfs_prop_to_name(prop);
1257 
1258 	if (nvlist_lookup_nvlist(nv, propname, &propval) == 0) {
1259 		VERIFY(nvlist_add_string(propval, ZPROP_VALUE, value) == 0);
1260 		return;
1261 	}
1262 
1263 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1264 	VERIFY(nvlist_add_string(propval, ZPROP_VALUE, value) == 0);
1265 	VERIFY(nvlist_add_nvlist(nv, propname, propval) == 0);
1266 	nvlist_free(propval);
1267 }
1268 
1269 #if defined(_KERNEL)
1270 EXPORT_SYMBOL(dsl_prop_register);
1271 EXPORT_SYMBOL(dsl_prop_unregister);
1272 EXPORT_SYMBOL(dsl_prop_unregister_all);
1273 EXPORT_SYMBOL(dsl_prop_get);
1274 EXPORT_SYMBOL(dsl_prop_get_integer);
1275 EXPORT_SYMBOL(dsl_prop_get_all);
1276 EXPORT_SYMBOL(dsl_prop_get_received);
1277 EXPORT_SYMBOL(dsl_prop_get_ds);
1278 EXPORT_SYMBOL(dsl_prop_get_int_ds);
1279 EXPORT_SYMBOL(dsl_prop_get_dd);
1280 EXPORT_SYMBOL(dsl_props_set);
1281 EXPORT_SYMBOL(dsl_prop_set_int);
1282 EXPORT_SYMBOL(dsl_prop_set_string);
1283 EXPORT_SYMBOL(dsl_prop_inherit);
1284 EXPORT_SYMBOL(dsl_prop_predict);
1285 EXPORT_SYMBOL(dsl_prop_nvlist_add_uint64);
1286 EXPORT_SYMBOL(dsl_prop_nvlist_add_string);
1287 #endif
1288