xref: /illumos-gate/usr/src/uts/common/fs/zfs/dmu_objset.c (revision a92282e44f968185a6bba094d1e5fece2da819cf)
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 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
25  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
26  * Copyright 2019 Joyent, Inc.
27  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
28  * Copyright (c) 2015, STRATO AG, Inc. All rights reserved.
29  * Copyright (c) 2014 Integros [integros.com]
30  * Copyright 2017 Nexenta Systems, Inc.
31  * Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
32  */
33 
34 /* Portions Copyright 2010 Robert Milkowski */
35 
36 #include <sys/zfeature.h>
37 #include <sys/cred.h>
38 #include <sys/zfs_context.h>
39 #include <sys/dmu_objset.h>
40 #include <sys/dsl_dir.h>
41 #include <sys/dsl_dataset.h>
42 #include <sys/dsl_prop.h>
43 #include <sys/dsl_pool.h>
44 #include <sys/dsl_synctask.h>
45 #include <sys/dsl_deleg.h>
46 #include <sys/dnode.h>
47 #include <sys/dbuf.h>
48 #include <sys/zvol.h>
49 #include <sys/dmu_tx.h>
50 #include <sys/zap.h>
51 #include <sys/zil.h>
52 #include <sys/dmu_impl.h>
53 #include <sys/zfs_ioctl.h>
54 #include <sys/sa.h>
55 #include <sys/zfs_onexit.h>
56 #include <sys/dsl_destroy.h>
57 #include <sys/vdev.h>
58 #include <sys/zfeature.h>
59 #include <sys/spa_impl.h>
60 #include <sys/dmu_recv.h>
61 #include <sys/zfs_project.h>
62 #include "zfs_namecheck.h"
63 
64 /*
65  * Needed to close a window in dnode_move() that allows the objset to be freed
66  * before it can be safely accessed.
67  */
68 krwlock_t os_lock;
69 
70 /*
71  * Tunable to overwrite the maximum number of threads for the parallization
72  * of dmu_objset_find_dp, needed to speed up the import of pools with many
73  * datasets.
74  * Default is 4 times the number of leaf vdevs.
75  */
76 int dmu_find_threads = 0;
77 
78 /*
79  * Backfill lower metadnode objects after this many have been freed.
80  * Backfilling negatively impacts object creation rates, so only do it
81  * if there are enough holes to fill.
82  */
83 int dmu_rescan_dnode_threshold = 131072;
84 
85 static char *upgrade_tag = "upgrade_tag";
86 
87 static void dmu_objset_find_dp_cb(void *arg);
88 
89 static void dmu_objset_upgrade(objset_t *os, dmu_objset_upgrade_cb_t cb);
90 static void dmu_objset_upgrade_stop(objset_t *os);
91 
92 void
93 dmu_objset_init(void)
94 {
95 	rw_init(&os_lock, NULL, RW_DEFAULT, NULL);
96 }
97 
98 void
99 dmu_objset_fini(void)
100 {
101 	rw_destroy(&os_lock);
102 }
103 
104 spa_t *
105 dmu_objset_spa(objset_t *os)
106 {
107 	return (os->os_spa);
108 }
109 
110 zilog_t *
111 dmu_objset_zil(objset_t *os)
112 {
113 	return (os->os_zil);
114 }
115 
116 dsl_pool_t *
117 dmu_objset_pool(objset_t *os)
118 {
119 	dsl_dataset_t *ds;
120 
121 	if ((ds = os->os_dsl_dataset) != NULL && ds->ds_dir)
122 		return (ds->ds_dir->dd_pool);
123 	else
124 		return (spa_get_dsl(os->os_spa));
125 }
126 
127 dsl_dataset_t *
128 dmu_objset_ds(objset_t *os)
129 {
130 	return (os->os_dsl_dataset);
131 }
132 
133 dmu_objset_type_t
134 dmu_objset_type(objset_t *os)
135 {
136 	return (os->os_phys->os_type);
137 }
138 
139 void
140 dmu_objset_name(objset_t *os, char *buf)
141 {
142 	dsl_dataset_name(os->os_dsl_dataset, buf);
143 }
144 
145 uint64_t
146 dmu_objset_id(objset_t *os)
147 {
148 	dsl_dataset_t *ds = os->os_dsl_dataset;
149 
150 	return (ds ? ds->ds_object : 0);
151 }
152 
153 uint64_t
154 dmu_objset_dnodesize(objset_t *os)
155 {
156 	return (os->os_dnodesize);
157 }
158 
159 zfs_sync_type_t
160 dmu_objset_syncprop(objset_t *os)
161 {
162 	return (os->os_sync);
163 }
164 
165 zfs_logbias_op_t
166 dmu_objset_logbias(objset_t *os)
167 {
168 	return (os->os_logbias);
169 }
170 
171 static void
172 checksum_changed_cb(void *arg, uint64_t newval)
173 {
174 	objset_t *os = arg;
175 
176 	/*
177 	 * Inheritance should have been done by now.
178 	 */
179 	ASSERT(newval != ZIO_CHECKSUM_INHERIT);
180 
181 	os->os_checksum = zio_checksum_select(newval, ZIO_CHECKSUM_ON_VALUE);
182 }
183 
184 static void
185 compression_changed_cb(void *arg, uint64_t newval)
186 {
187 	objset_t *os = arg;
188 
189 	/*
190 	 * Inheritance and range checking should have been done by now.
191 	 */
192 	ASSERT(newval != ZIO_COMPRESS_INHERIT);
193 
194 	os->os_compress = zio_compress_select(os->os_spa, newval,
195 	    ZIO_COMPRESS_ON);
196 }
197 
198 static void
199 copies_changed_cb(void *arg, uint64_t newval)
200 {
201 	objset_t *os = arg;
202 
203 	/*
204 	 * Inheritance and range checking should have been done by now.
205 	 */
206 	ASSERT(newval > 0);
207 	ASSERT(newval <= spa_max_replication(os->os_spa));
208 
209 	os->os_copies = newval;
210 }
211 
212 static void
213 dedup_changed_cb(void *arg, uint64_t newval)
214 {
215 	objset_t *os = arg;
216 	spa_t *spa = os->os_spa;
217 	enum zio_checksum checksum;
218 
219 	/*
220 	 * Inheritance should have been done by now.
221 	 */
222 	ASSERT(newval != ZIO_CHECKSUM_INHERIT);
223 
224 	checksum = zio_checksum_dedup_select(spa, newval, ZIO_CHECKSUM_OFF);
225 
226 	os->os_dedup_checksum = checksum & ZIO_CHECKSUM_MASK;
227 	os->os_dedup_verify = !!(checksum & ZIO_CHECKSUM_VERIFY);
228 }
229 
230 static void
231 primary_cache_changed_cb(void *arg, uint64_t newval)
232 {
233 	objset_t *os = arg;
234 
235 	/*
236 	 * Inheritance and range checking should have been done by now.
237 	 */
238 	ASSERT(newval == ZFS_CACHE_ALL || newval == ZFS_CACHE_NONE ||
239 	    newval == ZFS_CACHE_METADATA);
240 
241 	os->os_primary_cache = newval;
242 }
243 
244 static void
245 secondary_cache_changed_cb(void *arg, uint64_t newval)
246 {
247 	objset_t *os = arg;
248 
249 	/*
250 	 * Inheritance and range checking should have been done by now.
251 	 */
252 	ASSERT(newval == ZFS_CACHE_ALL || newval == ZFS_CACHE_NONE ||
253 	    newval == ZFS_CACHE_METADATA);
254 
255 	os->os_secondary_cache = newval;
256 }
257 
258 static void
259 sync_changed_cb(void *arg, uint64_t newval)
260 {
261 	objset_t *os = arg;
262 
263 	/*
264 	 * Inheritance and range checking should have been done by now.
265 	 */
266 	ASSERT(newval == ZFS_SYNC_STANDARD || newval == ZFS_SYNC_ALWAYS ||
267 	    newval == ZFS_SYNC_DISABLED);
268 
269 	os->os_sync = newval;
270 	if (os->os_zil)
271 		zil_set_sync(os->os_zil, newval);
272 }
273 
274 static void
275 redundant_metadata_changed_cb(void *arg, uint64_t newval)
276 {
277 	objset_t *os = arg;
278 
279 	/*
280 	 * Inheritance and range checking should have been done by now.
281 	 */
282 	ASSERT(newval == ZFS_REDUNDANT_METADATA_ALL ||
283 	    newval == ZFS_REDUNDANT_METADATA_MOST);
284 
285 	os->os_redundant_metadata = newval;
286 }
287 
288 static void
289 dnodesize_changed_cb(void *arg, uint64_t newval)
290 {
291 	objset_t *os = arg;
292 
293 	switch (newval) {
294 	case ZFS_DNSIZE_LEGACY:
295 		os->os_dnodesize = DNODE_MIN_SIZE;
296 		break;
297 	case ZFS_DNSIZE_AUTO:
298 		/*
299 		 * Choose a dnode size that will work well for most
300 		 * workloads if the user specified "auto". Future code
301 		 * improvements could dynamically select a dnode size
302 		 * based on observed workload patterns.
303 		 */
304 		os->os_dnodesize = DNODE_MIN_SIZE * 2;
305 		break;
306 	case ZFS_DNSIZE_1K:
307 	case ZFS_DNSIZE_2K:
308 	case ZFS_DNSIZE_4K:
309 	case ZFS_DNSIZE_8K:
310 	case ZFS_DNSIZE_16K:
311 		os->os_dnodesize = newval;
312 		break;
313 	}
314 }
315 
316 static void
317 smallblk_changed_cb(void *arg, uint64_t newval)
318 {
319 	objset_t *os = arg;
320 
321 	/*
322 	 * Inheritance and range checking should have been done by now.
323 	 */
324 	ASSERT(newval <= SPA_OLD_MAXBLOCKSIZE);
325 	ASSERT(ISP2(newval));
326 
327 	os->os_zpl_special_smallblock = newval;
328 }
329 
330 static void
331 logbias_changed_cb(void *arg, uint64_t newval)
332 {
333 	objset_t *os = arg;
334 
335 	ASSERT(newval == ZFS_LOGBIAS_LATENCY ||
336 	    newval == ZFS_LOGBIAS_THROUGHPUT);
337 	os->os_logbias = newval;
338 	if (os->os_zil)
339 		zil_set_logbias(os->os_zil, newval);
340 }
341 
342 static void
343 recordsize_changed_cb(void *arg, uint64_t newval)
344 {
345 	objset_t *os = arg;
346 
347 	os->os_recordsize = newval;
348 }
349 
350 void
351 dmu_objset_byteswap(void *buf, size_t size)
352 {
353 	objset_phys_t *osp = buf;
354 
355 	ASSERT(size == OBJSET_PHYS_SIZE_V1 || size == OBJSET_PHYS_SIZE_V2 ||
356 	    size == sizeof (objset_phys_t));
357 	dnode_byteswap(&osp->os_meta_dnode);
358 	byteswap_uint64_array(&osp->os_zil_header, sizeof (zil_header_t));
359 	osp->os_type = BSWAP_64(osp->os_type);
360 	osp->os_flags = BSWAP_64(osp->os_flags);
361 	if (size >= OBJSET_PHYS_SIZE_V2) {
362 		dnode_byteswap(&osp->os_userused_dnode);
363 		dnode_byteswap(&osp->os_groupused_dnode);
364 		if (size >= sizeof (objset_phys_t))
365 			dnode_byteswap(&osp->os_projectused_dnode);
366 	}
367 }
368 
369 /*
370  * The hash is a CRC-based hash of the objset_t pointer and the object number.
371  */
372 static uint64_t
373 dnode_hash(const objset_t *os, uint64_t obj)
374 {
375 	uintptr_t osv = (uintptr_t)os;
376 	uint64_t crc = -1ULL;
377 
378 	ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);
379 	/*
380 	 * The low 6 bits of the pointer don't have much entropy, because
381 	 * the objset_t is larger than 2^6 bytes long.
382 	 */
383 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (osv >> 6)) & 0xFF];
384 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 0)) & 0xFF];
385 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 8)) & 0xFF];
386 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 16)) & 0xFF];
387 
388 	crc ^= (osv>>14) ^ (obj>>24);
389 
390 	return (crc);
391 }
392 
393 unsigned int
394 dnode_multilist_index_func(multilist_t *ml, void *obj)
395 {
396 	dnode_t *dn = obj;
397 	return (dnode_hash(dn->dn_objset, dn->dn_object) %
398 	    multilist_get_num_sublists(ml));
399 }
400 
401 /*
402  * Instantiates the objset_t in-memory structure corresponding to the
403  * objset_phys_t that's pointed to by the specified blkptr_t.
404  */
405 int
406 dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
407     objset_t **osp)
408 {
409 	objset_t *os;
410 	int i, err;
411 
412 	ASSERT(ds == NULL || MUTEX_HELD(&ds->ds_opening_lock));
413 
414 #if 0
415 	/*
416 	 * The $ORIGIN dataset (if it exists) doesn't have an associated
417 	 * objset, so there's no reason to open it. The $ORIGIN dataset
418 	 * will not exist on pools older than SPA_VERSION_ORIGIN.
419 	 */
420 	if (ds != NULL && spa_get_dsl(spa) != NULL &&
421 	    spa_get_dsl(spa)->dp_origin_snap != NULL) {
422 		ASSERT3P(ds->ds_dir, !=,
423 		    spa_get_dsl(spa)->dp_origin_snap->ds_dir);
424 	}
425 #endif
426 
427 	os = kmem_zalloc(sizeof (objset_t), KM_SLEEP);
428 	os->os_dsl_dataset = ds;
429 	os->os_spa = spa;
430 	os->os_rootbp = bp;
431 	if (!BP_IS_HOLE(os->os_rootbp)) {
432 		arc_flags_t aflags = ARC_FLAG_WAIT;
433 		zbookmark_phys_t zb;
434 		int size;
435 		enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
436 		SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
437 		    ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
438 
439 		if (DMU_OS_IS_L2CACHEABLE(os))
440 			aflags |= ARC_FLAG_L2CACHE;
441 
442 		if (ds != NULL && ds->ds_dir->dd_crypto_obj != 0) {
443 			ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
444 			ASSERT(BP_IS_AUTHENTICATED(bp));
445 			zio_flags |= ZIO_FLAG_RAW;
446 		}
447 
448 		dprintf_bp(os->os_rootbp, "reading %s", "");
449 		err = arc_read(NULL, spa, os->os_rootbp,
450 		    arc_getbuf_func, &os->os_phys_buf,
451 		    ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
452 		if (err != 0) {
453 			kmem_free(os, sizeof (objset_t));
454 			/* convert checksum errors into IO errors */
455 			if (err == ECKSUM)
456 				err = SET_ERROR(EIO);
457 			return (err);
458 		}
459 
460 		if (spa_version(spa) < SPA_VERSION_USERSPACE)
461 			size = OBJSET_PHYS_SIZE_V1;
462 		else if (!spa_feature_is_enabled(spa,
463 		    SPA_FEATURE_PROJECT_QUOTA))
464 			size = OBJSET_PHYS_SIZE_V2;
465 		else
466 			size = sizeof (objset_phys_t);
467 
468 		/* Increase the blocksize if we are permitted. */
469 		if (arc_buf_size(os->os_phys_buf) < size) {
470 			arc_buf_t *buf = arc_alloc_buf(spa, &os->os_phys_buf,
471 			    ARC_BUFC_METADATA, size);
472 			bzero(buf->b_data, size);
473 			bcopy(os->os_phys_buf->b_data, buf->b_data,
474 			    arc_buf_size(os->os_phys_buf));
475 			arc_buf_destroy(os->os_phys_buf, &os->os_phys_buf);
476 			os->os_phys_buf = buf;
477 		}
478 
479 		os->os_phys = os->os_phys_buf->b_data;
480 		os->os_flags = os->os_phys->os_flags;
481 	} else {
482 		int size = spa_version(spa) >= SPA_VERSION_USERSPACE ?
483 		    sizeof (objset_phys_t) : OBJSET_PHYS_SIZE_V1;
484 		os->os_phys_buf = arc_alloc_buf(spa, &os->os_phys_buf,
485 		    ARC_BUFC_METADATA, size);
486 		os->os_phys = os->os_phys_buf->b_data;
487 		bzero(os->os_phys, size);
488 	}
489 
490 	/*
491 	 * Note: the changed_cb will be called once before the register
492 	 * func returns, thus changing the checksum/compression from the
493 	 * default (fletcher2/off).  Snapshots don't need to know about
494 	 * checksum/compression/copies.
495 	 */
496 	if (ds != NULL) {
497 		boolean_t needlock = B_FALSE;
498 
499 		os->os_encrypted = (ds->ds_dir->dd_crypto_obj != 0);
500 
501 		/*
502 		 * Note: it's valid to open the objset if the dataset is
503 		 * long-held, in which case the pool_config lock will not
504 		 * be held.
505 		 */
506 		if (!dsl_pool_config_held(dmu_objset_pool(os))) {
507 			needlock = B_TRUE;
508 			dsl_pool_config_enter(dmu_objset_pool(os), FTAG);
509 		}
510 
511 		err = dsl_prop_register(ds,
512 		    zfs_prop_to_name(ZFS_PROP_PRIMARYCACHE),
513 		    primary_cache_changed_cb, os);
514 		if (err == 0) {
515 			err = dsl_prop_register(ds,
516 			    zfs_prop_to_name(ZFS_PROP_SECONDARYCACHE),
517 			    secondary_cache_changed_cb, os);
518 		}
519 		if (!ds->ds_is_snapshot) {
520 			if (err == 0) {
521 				err = dsl_prop_register(ds,
522 				    zfs_prop_to_name(ZFS_PROP_CHECKSUM),
523 				    checksum_changed_cb, os);
524 			}
525 			if (err == 0) {
526 				err = dsl_prop_register(ds,
527 				    zfs_prop_to_name(ZFS_PROP_COMPRESSION),
528 				    compression_changed_cb, os);
529 			}
530 			if (err == 0) {
531 				err = dsl_prop_register(ds,
532 				    zfs_prop_to_name(ZFS_PROP_COPIES),
533 				    copies_changed_cb, os);
534 			}
535 			if (err == 0) {
536 				err = dsl_prop_register(ds,
537 				    zfs_prop_to_name(ZFS_PROP_DEDUP),
538 				    dedup_changed_cb, os);
539 			}
540 			if (err == 0) {
541 				err = dsl_prop_register(ds,
542 				    zfs_prop_to_name(ZFS_PROP_LOGBIAS),
543 				    logbias_changed_cb, os);
544 			}
545 			if (err == 0) {
546 				err = dsl_prop_register(ds,
547 				    zfs_prop_to_name(ZFS_PROP_SYNC),
548 				    sync_changed_cb, os);
549 			}
550 			if (err == 0) {
551 				err = dsl_prop_register(ds,
552 				    zfs_prop_to_name(
553 				    ZFS_PROP_REDUNDANT_METADATA),
554 				    redundant_metadata_changed_cb, os);
555 			}
556 			if (err == 0) {
557 				err = dsl_prop_register(ds,
558 				    zfs_prop_to_name(ZFS_PROP_RECORDSIZE),
559 				    recordsize_changed_cb, os);
560 			}
561 			if (err == 0) {
562 				err = dsl_prop_register(ds,
563 				    zfs_prop_to_name(ZFS_PROP_DNODESIZE),
564 				    dnodesize_changed_cb, os);
565 			}
566 			if (err == 0) {
567 				err = dsl_prop_register(ds,
568 				    zfs_prop_to_name(
569 				    ZFS_PROP_SPECIAL_SMALL_BLOCKS),
570 				    smallblk_changed_cb, os);
571 			}
572 		}
573 		if (needlock)
574 			dsl_pool_config_exit(dmu_objset_pool(os), FTAG);
575 		if (err != 0) {
576 			arc_buf_destroy(os->os_phys_buf, &os->os_phys_buf);
577 			kmem_free(os, sizeof (objset_t));
578 			return (err);
579 		}
580 	} else {
581 		/* It's the meta-objset. */
582 		os->os_checksum = ZIO_CHECKSUM_FLETCHER_4;
583 		os->os_compress = ZIO_COMPRESS_ON;
584 		os->os_encrypted = B_FALSE;
585 		os->os_copies = spa_max_replication(spa);
586 		os->os_dedup_checksum = ZIO_CHECKSUM_OFF;
587 		os->os_dedup_verify = B_FALSE;
588 		os->os_logbias = ZFS_LOGBIAS_LATENCY;
589 		os->os_sync = ZFS_SYNC_STANDARD;
590 		os->os_primary_cache = ZFS_CACHE_ALL;
591 		os->os_secondary_cache = ZFS_CACHE_ALL;
592 		os->os_dnodesize = DNODE_MIN_SIZE;
593 	}
594 	/*
595 	 * These properties will be filled in by the logic in zfs_get_zplprop()
596 	 * when they are queried for the first time.
597 	 */
598 	os->os_version = OBJSET_PROP_UNINITIALIZED;
599 	os->os_normalization = OBJSET_PROP_UNINITIALIZED;
600 	os->os_utf8only = OBJSET_PROP_UNINITIALIZED;
601 	os->os_casesensitivity = OBJSET_PROP_UNINITIALIZED;
602 
603 	if (ds == NULL || !ds->ds_is_snapshot)
604 		os->os_zil_header = os->os_phys->os_zil_header;
605 	os->os_zil = zil_alloc(os, &os->os_zil_header);
606 
607 	for (i = 0; i < TXG_SIZE; i++) {
608 		os->os_dirty_dnodes[i] = multilist_create(sizeof (dnode_t),
609 		    offsetof(dnode_t, dn_dirty_link[i]),
610 		    dnode_multilist_index_func);
611 	}
612 	list_create(&os->os_dnodes, sizeof (dnode_t),
613 	    offsetof(dnode_t, dn_link));
614 	list_create(&os->os_downgraded_dbufs, sizeof (dmu_buf_impl_t),
615 	    offsetof(dmu_buf_impl_t, db_link));
616 
617 	mutex_init(&os->os_lock, NULL, MUTEX_DEFAULT, NULL);
618 	mutex_init(&os->os_userused_lock, NULL, MUTEX_DEFAULT, NULL);
619 	mutex_init(&os->os_obj_lock, NULL, MUTEX_DEFAULT, NULL);
620 	mutex_init(&os->os_user_ptr_lock, NULL, MUTEX_DEFAULT, NULL);
621 	os->os_obj_next_percpu_len = boot_ncpus;
622 	os->os_obj_next_percpu = kmem_zalloc(os->os_obj_next_percpu_len *
623 	    sizeof (os->os_obj_next_percpu[0]), KM_SLEEP);
624 
625 	dnode_special_open(os, &os->os_phys->os_meta_dnode,
626 	    DMU_META_DNODE_OBJECT, &os->os_meta_dnode);
627 	if (OBJSET_BUF_HAS_USERUSED(os->os_phys_buf)) {
628 		dnode_special_open(os, &os->os_phys->os_userused_dnode,
629 		    DMU_USERUSED_OBJECT, &os->os_userused_dnode);
630 		dnode_special_open(os, &os->os_phys->os_groupused_dnode,
631 		    DMU_GROUPUSED_OBJECT, &os->os_groupused_dnode);
632 		if (OBJSET_BUF_HAS_PROJECTUSED(os->os_phys_buf))
633 			dnode_special_open(os,
634 			    &os->os_phys->os_projectused_dnode,
635 			    DMU_PROJECTUSED_OBJECT, &os->os_projectused_dnode);
636 	}
637 
638 	mutex_init(&os->os_upgrade_lock, NULL, MUTEX_DEFAULT, NULL);
639 
640 	*osp = os;
641 	return (0);
642 }
643 
644 int
645 dmu_objset_from_ds(dsl_dataset_t *ds, objset_t **osp)
646 {
647 	int err = 0;
648 
649 	/*
650 	 * We shouldn't be doing anything with dsl_dataset_t's unless the
651 	 * pool_config lock is held, or the dataset is long-held.
652 	 */
653 	ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool) ||
654 	    dsl_dataset_long_held(ds));
655 
656 	mutex_enter(&ds->ds_opening_lock);
657 	if (ds->ds_objset == NULL) {
658 		objset_t *os;
659 		rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
660 		err = dmu_objset_open_impl(dsl_dataset_get_spa(ds),
661 		    ds, dsl_dataset_get_blkptr(ds), &os);
662 		rrw_exit(&ds->ds_bp_rwlock, FTAG);
663 
664 		if (err == 0) {
665 			mutex_enter(&ds->ds_lock);
666 			ASSERT(ds->ds_objset == NULL);
667 			ds->ds_objset = os;
668 			mutex_exit(&ds->ds_lock);
669 		}
670 	}
671 	*osp = ds->ds_objset;
672 	mutex_exit(&ds->ds_opening_lock);
673 	return (err);
674 }
675 
676 /*
677  * Holds the pool while the objset is held.  Therefore only one objset
678  * can be held at a time.
679  */
680 int
681 dmu_objset_hold_flags(const char *name, boolean_t decrypt, void *tag,
682     objset_t **osp)
683 {
684 	dsl_pool_t *dp;
685 	dsl_dataset_t *ds;
686 	int err;
687 	ds_hold_flags_t flags = (decrypt) ? DS_HOLD_FLAG_DECRYPT : 0;
688 
689 	err = dsl_pool_hold(name, tag, &dp);
690 	if (err != 0)
691 		return (err);
692 	err = dsl_dataset_hold_flags(dp, name, flags, tag, &ds);
693 	if (err != 0) {
694 		dsl_pool_rele(dp, tag);
695 		return (err);
696 	}
697 
698 	err = dmu_objset_from_ds(ds, osp);
699 	if (err != 0) {
700 		dsl_dataset_rele(ds, tag);
701 		dsl_pool_rele(dp, tag);
702 	}
703 
704 	return (err);
705 }
706 
707 int
708 dmu_objset_hold(const char *name, void *tag, objset_t **osp)
709 {
710 	return (dmu_objset_hold_flags(name, B_FALSE, tag, osp));
711 }
712 
713 /* ARGSUSED */
714 static int
715 dmu_objset_own_impl(dsl_dataset_t *ds, dmu_objset_type_t type,
716     boolean_t readonly, boolean_t decrypt, void *tag, objset_t **osp)
717 {
718 	int err;
719 
720 	err = dmu_objset_from_ds(ds, osp);
721 	if (err != 0) {
722 		return (err);
723 	} else if (type != DMU_OST_ANY && type != (*osp)->os_phys->os_type) {
724 		return (SET_ERROR(EINVAL));
725 	} else if (!readonly && dsl_dataset_is_snapshot(ds)) {
726 		return (SET_ERROR(EROFS));
727 	} else if (!readonly && decrypt &&
728 	    dsl_dir_incompatible_encryption_version(ds->ds_dir)) {
729 		return (SET_ERROR(EROFS));
730 	}
731 
732 	/* if we are decrypting, we can now check MACs in os->os_phys_buf */
733 	if (decrypt && arc_is_unauthenticated((*osp)->os_phys_buf)) {
734 		zbookmark_phys_t zb;
735 
736 		SET_BOOKMARK(&zb, ds->ds_object, ZB_ROOT_OBJECT,
737 		    ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
738 		err = arc_untransform((*osp)->os_phys_buf, (*osp)->os_spa,
739 		    &zb, B_FALSE);
740 		if (err != 0)
741 			return (err);
742 
743 		ASSERT0(arc_is_unauthenticated((*osp)->os_phys_buf));
744 	}
745 
746 	return (0);
747 }
748 
749 /*
750  * dsl_pool must not be held when this is called.
751  * Upon successful return, there will be a longhold on the dataset,
752  * and the dsl_pool will not be held.
753  */
754 int
755 dmu_objset_own(const char *name, dmu_objset_type_t type,
756     boolean_t readonly, boolean_t decrypt, void *tag, objset_t **osp)
757 {
758 	dsl_pool_t *dp;
759 	dsl_dataset_t *ds;
760 	int err;
761 	ds_hold_flags_t flags = (decrypt) ? DS_HOLD_FLAG_DECRYPT : 0;
762 
763 	err = dsl_pool_hold(name, FTAG, &dp);
764 	if (err != 0)
765 		return (err);
766 	err = dsl_dataset_own(dp, name, flags, tag, &ds);
767 	if (err != 0) {
768 		dsl_pool_rele(dp, FTAG);
769 		return (err);
770 	}
771 	err = dmu_objset_own_impl(ds, type, readonly, decrypt, tag, osp);
772 	if (err != 0) {
773 		dsl_dataset_disown(ds, flags, tag);
774 		dsl_pool_rele(dp, FTAG);
775 		return (err);
776 	}
777 
778 	/*
779 	 * User accounting requires the dataset to be decrypted and rw.
780 	 * We also don't begin user accounting during claiming to help
781 	 * speed up pool import times and to keep this txg reserved
782 	 * completely for recovery work.
783 	 */
784 	if ((dmu_objset_userobjspace_upgradable(*osp) ||
785 	    dmu_objset_projectquota_upgradable(*osp)) &&
786 	    !readonly && !dp->dp_spa->spa_claiming &&
787 	    (ds->ds_dir->dd_crypto_obj == 0 || decrypt))
788 		dmu_objset_id_quota_upgrade(*osp);
789 
790 	dsl_pool_rele(dp, FTAG);
791 	return (0);
792 }
793 
794 int
795 dmu_objset_own_obj(dsl_pool_t *dp, uint64_t obj, dmu_objset_type_t type,
796     boolean_t readonly, boolean_t decrypt, void *tag, objset_t **osp)
797 {
798 	dsl_dataset_t *ds;
799 	int err;
800 	ds_hold_flags_t flags = (decrypt) ? DS_HOLD_FLAG_DECRYPT : 0;
801 
802 	err = dsl_dataset_own_obj(dp, obj, flags, tag, &ds);
803 	if (err != 0)
804 		return (err);
805 
806 	err = dmu_objset_own_impl(ds, type, readonly, decrypt, tag, osp);
807 	if (err != 0) {
808 		dsl_dataset_disown(ds, flags, tag);
809 		return (err);
810 	}
811 
812 	return (0);
813 }
814 
815 void
816 dmu_objset_rele_flags(objset_t *os, boolean_t decrypt, void *tag)
817 {
818 	ds_hold_flags_t flags = (decrypt) ? DS_HOLD_FLAG_DECRYPT : 0;
819 
820 	dsl_pool_t *dp = dmu_objset_pool(os);
821 	dsl_dataset_rele_flags(os->os_dsl_dataset, flags, tag);
822 	dsl_pool_rele(dp, tag);
823 }
824 
825 void
826 dmu_objset_rele(objset_t *os, void *tag)
827 {
828 	dmu_objset_rele_flags(os, B_FALSE, tag);
829 }
830 
831 /*
832  * When we are called, os MUST refer to an objset associated with a dataset
833  * that is owned by 'tag'; that is, is held and long held by 'tag' and ds_owner
834  * == tag.  We will then release and reacquire ownership of the dataset while
835  * holding the pool config_rwlock to avoid intervening namespace or ownership
836  * changes may occur.
837  *
838  * This exists solely to accommodate zfs_ioc_userspace_upgrade()'s desire to
839  * release the hold on its dataset and acquire a new one on the dataset of the
840  * same name so that it can be partially torn down and reconstructed.
841  */
842 void
843 dmu_objset_refresh_ownership(dsl_dataset_t *ds, dsl_dataset_t **newds,
844     boolean_t decrypt, void *tag)
845 {
846 	dsl_pool_t *dp;
847 	char name[ZFS_MAX_DATASET_NAME_LEN];
848 
849 	VERIFY3P(ds, !=, NULL);
850 	VERIFY3P(ds->ds_owner, ==, tag);
851 	VERIFY(dsl_dataset_long_held(ds));
852 
853 	dsl_dataset_name(ds, name);
854 	dp = ds->ds_dir->dd_pool;
855 	dsl_pool_config_enter(dp, FTAG);
856 
857 	dsl_dataset_disown(ds, decrypt, tag);
858 	VERIFY0(dsl_dataset_own(dp, name,
859 	    (decrypt) ? DS_HOLD_FLAG_DECRYPT : 0, tag, newds));
860 	dsl_pool_config_exit(dp, FTAG);
861 }
862 
863 void
864 dmu_objset_disown(objset_t *os, boolean_t decrypt, void *tag)
865 {
866 	/*
867 	 * Stop upgrading thread
868 	 */
869 	dmu_objset_upgrade_stop(os);
870 	dsl_dataset_disown(os->os_dsl_dataset,
871 	    (decrypt) ? DS_HOLD_FLAG_DECRYPT : 0, tag);
872 }
873 
874 void
875 dmu_objset_evict_dbufs(objset_t *os)
876 {
877 	dnode_t dn_marker;
878 	dnode_t *dn;
879 
880 	mutex_enter(&os->os_lock);
881 	dn = list_head(&os->os_dnodes);
882 	while (dn != NULL) {
883 		/*
884 		 * Skip dnodes without holds.  We have to do this dance
885 		 * because dnode_add_ref() only works if there is already a
886 		 * hold.  If the dnode has no holds, then it has no dbufs.
887 		 */
888 		if (dnode_add_ref(dn, FTAG)) {
889 			list_insert_after(&os->os_dnodes, dn, &dn_marker);
890 			mutex_exit(&os->os_lock);
891 
892 			dnode_evict_dbufs(dn);
893 			dnode_rele(dn, FTAG);
894 
895 			mutex_enter(&os->os_lock);
896 			dn = list_next(&os->os_dnodes, &dn_marker);
897 			list_remove(&os->os_dnodes, &dn_marker);
898 		} else {
899 			dn = list_next(&os->os_dnodes, dn);
900 		}
901 	}
902 	mutex_exit(&os->os_lock);
903 
904 	if (DMU_USERUSED_DNODE(os) != NULL) {
905 		if (DMU_PROJECTUSED_DNODE(os) != NULL)
906 			dnode_evict_dbufs(DMU_PROJECTUSED_DNODE(os));
907 		dnode_evict_dbufs(DMU_GROUPUSED_DNODE(os));
908 		dnode_evict_dbufs(DMU_USERUSED_DNODE(os));
909 	}
910 	dnode_evict_dbufs(DMU_META_DNODE(os));
911 }
912 
913 /*
914  * Objset eviction processing is split into into two pieces.
915  * The first marks the objset as evicting, evicts any dbufs that
916  * have a refcount of zero, and then queues up the objset for the
917  * second phase of eviction.  Once os->os_dnodes has been cleared by
918  * dnode_buf_pageout()->dnode_destroy(), the second phase is executed.
919  * The second phase closes the special dnodes, dequeues the objset from
920  * the list of those undergoing eviction, and finally frees the objset.
921  *
922  * NOTE: Due to asynchronous eviction processing (invocation of
923  *       dnode_buf_pageout()), it is possible for the meta dnode for the
924  *       objset to have no holds even though os->os_dnodes is not empty.
925  */
926 void
927 dmu_objset_evict(objset_t *os)
928 {
929 	dsl_dataset_t *ds = os->os_dsl_dataset;
930 
931 	for (int t = 0; t < TXG_SIZE; t++)
932 		ASSERT(!dmu_objset_is_dirty(os, t));
933 
934 	if (ds)
935 		dsl_prop_unregister_all(ds, os);
936 
937 	if (os->os_sa)
938 		sa_tear_down(os);
939 
940 	dmu_objset_evict_dbufs(os);
941 
942 	mutex_enter(&os->os_lock);
943 	spa_evicting_os_register(os->os_spa, os);
944 	if (list_is_empty(&os->os_dnodes)) {
945 		mutex_exit(&os->os_lock);
946 		dmu_objset_evict_done(os);
947 	} else {
948 		mutex_exit(&os->os_lock);
949 	}
950 
951 
952 }
953 
954 void
955 dmu_objset_evict_done(objset_t *os)
956 {
957 	ASSERT3P(list_head(&os->os_dnodes), ==, NULL);
958 
959 	dnode_special_close(&os->os_meta_dnode);
960 	if (DMU_USERUSED_DNODE(os)) {
961 		if (DMU_PROJECTUSED_DNODE(os))
962 			dnode_special_close(&os->os_projectused_dnode);
963 		dnode_special_close(&os->os_userused_dnode);
964 		dnode_special_close(&os->os_groupused_dnode);
965 	}
966 	zil_free(os->os_zil);
967 
968 	arc_buf_destroy(os->os_phys_buf, &os->os_phys_buf);
969 
970 	/*
971 	 * This is a barrier to prevent the objset from going away in
972 	 * dnode_move() until we can safely ensure that the objset is still in
973 	 * use. We consider the objset valid before the barrier and invalid
974 	 * after the barrier.
975 	 */
976 	rw_enter(&os_lock, RW_READER);
977 	rw_exit(&os_lock);
978 
979 	kmem_free(os->os_obj_next_percpu,
980 	    os->os_obj_next_percpu_len * sizeof (os->os_obj_next_percpu[0]));
981 
982 	mutex_destroy(&os->os_lock);
983 	mutex_destroy(&os->os_userused_lock);
984 	mutex_destroy(&os->os_obj_lock);
985 	mutex_destroy(&os->os_user_ptr_lock);
986 	mutex_destroy(&os->os_upgrade_lock);
987 	for (int i = 0; i < TXG_SIZE; i++) {
988 		multilist_destroy(os->os_dirty_dnodes[i]);
989 	}
990 	spa_evicting_os_deregister(os->os_spa, os);
991 	kmem_free(os, sizeof (objset_t));
992 }
993 
994 timestruc_t
995 dmu_objset_snap_cmtime(objset_t *os)
996 {
997 	return (dsl_dir_snap_cmtime(os->os_dsl_dataset->ds_dir));
998 }
999 
1000 /* ARGSUSED */
1001 objset_t *
1002 dmu_objset_create_impl_dnstats(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
1003     dmu_objset_type_t type, int levels, int blksz, int ibs, dmu_tx_t *tx)
1004 {
1005 	objset_t *os;
1006 	dnode_t *mdn;
1007 
1008 	ASSERT(dmu_tx_is_syncing(tx));
1009 
1010 	if (blksz == 0)
1011 		blksz = 1 << DNODE_BLOCK_SHIFT;
1012 	if (ibs == 0)
1013 		ibs = DN_MAX_INDBLKSHIFT;
1014 
1015 	if (ds != NULL)
1016 		VERIFY0(dmu_objset_from_ds(ds, &os));
1017 	else
1018 		VERIFY0(dmu_objset_open_impl(spa, NULL, bp, &os));
1019 
1020 	mdn = DMU_META_DNODE(os);
1021 
1022 	dnode_allocate(mdn, DMU_OT_DNODE, DNODE_BLOCK_SIZE, DN_MAX_INDBLKSHIFT,
1023 	    DMU_OT_NONE, 0, DNODE_MIN_SLOTS, tx);
1024 
1025 	/*
1026 	 * We don't want to have to increase the meta-dnode's nlevels
1027 	 * later, because then we could do it in quescing context while
1028 	 * we are also accessing it in open context.
1029 	 *
1030 	 * This precaution is not necessary for the MOS (ds == NULL),
1031 	 * because the MOS is only updated in syncing context.
1032 	 * This is most fortunate: the MOS is the only objset that
1033 	 * needs to be synced multiple times as spa_sync() iterates
1034 	 * to convergence, so minimizing its dn_nlevels matters.
1035 	 */
1036 	if (ds != NULL) {
1037 		if (levels == 0) {
1038 			levels = 1;
1039 
1040 			/*
1041 			 * Determine the number of levels necessary for the
1042 			 * meta-dnode to contain DN_MAX_OBJECT dnodes.  Note
1043 			 * that in order to ensure that we do not overflow
1044 			 * 64 bits, there has to be a nlevels that gives us a
1045 			 * number of blocks > DN_MAX_OBJECT but < 2^64.
1046 			 * Therefore, (mdn->dn_indblkshift - SPA_BLKPTRSHIFT)
1047 			 * (10) must be less than (64 - log2(DN_MAX_OBJECT))
1048 			 * (16).
1049 			 */
1050 			while ((uint64_t)mdn->dn_nblkptr <<
1051 			    (mdn->dn_datablkshift - DNODE_SHIFT + (levels - 1) *
1052 			    (mdn->dn_indblkshift - SPA_BLKPTRSHIFT)) <
1053 			    DN_MAX_OBJECT)
1054 				levels++;
1055 		}
1056 
1057 		mdn->dn_next_nlevels[tx->tx_txg & TXG_MASK] =
1058 		    mdn->dn_nlevels = levels;
1059 	}
1060 
1061 	ASSERT(type != DMU_OST_NONE);
1062 	ASSERT(type != DMU_OST_ANY);
1063 	ASSERT(type < DMU_OST_NUMTYPES);
1064 	os->os_phys->os_type = type;
1065 
1066 	/*
1067 	 * Enable user accounting if it is enabled and this is not an
1068 	 * encrypted receive.
1069 	 */
1070 	if (dmu_objset_userused_enabled(os) &&
1071 	    (!os->os_encrypted || !dmu_objset_is_receiving(os))) {
1072 		os->os_phys->os_flags |= OBJSET_FLAG_USERACCOUNTING_COMPLETE;
1073 		if (dmu_objset_userobjused_enabled(os)) {
1074 			ds->ds_feature_activation_needed[
1075 			    SPA_FEATURE_USEROBJ_ACCOUNTING] = B_TRUE;
1076 			os->os_phys->os_flags |=
1077 			    OBJSET_FLAG_USEROBJACCOUNTING_COMPLETE;
1078 		}
1079 		if (dmu_objset_projectquota_enabled(os)) {
1080 			ds->ds_feature_activation_needed[
1081 			    SPA_FEATURE_PROJECT_QUOTA] = B_TRUE;
1082 			os->os_phys->os_flags |=
1083 			    OBJSET_FLAG_PROJECTQUOTA_COMPLETE;
1084 		}
1085 		os->os_flags = os->os_phys->os_flags;
1086 	}
1087 
1088 	dsl_dataset_dirty(ds, tx);
1089 
1090 	return (os);
1091 }
1092 
1093 /* called from dsl for meta-objset */
1094 objset_t *
1095 dmu_objset_create_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
1096     dmu_objset_type_t type, dmu_tx_t *tx)
1097 {
1098 	return (dmu_objset_create_impl_dnstats(spa, ds, bp, type, 0, 0, 0, tx));
1099 }
1100 
1101 typedef struct dmu_objset_create_arg {
1102 	const char *doca_name;
1103 	cred_t *doca_cred;
1104 	void (*doca_userfunc)(objset_t *os, void *arg,
1105 	    cred_t *cr, dmu_tx_t *tx);
1106 	void *doca_userarg;
1107 	dmu_objset_type_t doca_type;
1108 	uint64_t doca_flags;
1109 	dsl_crypto_params_t *doca_dcp;
1110 } dmu_objset_create_arg_t;
1111 
1112 /*ARGSUSED*/
1113 static int
1114 dmu_objset_create_check(void *arg, dmu_tx_t *tx)
1115 {
1116 	dmu_objset_create_arg_t *doca = arg;
1117 	dsl_pool_t *dp = dmu_tx_pool(tx);
1118 	dsl_dir_t *pdd;
1119 	const char *tail;
1120 	int error;
1121 
1122 	if (strchr(doca->doca_name, '@') != NULL)
1123 		return (SET_ERROR(EINVAL));
1124 
1125 	if (strlen(doca->doca_name) >= ZFS_MAX_DATASET_NAME_LEN)
1126 		return (SET_ERROR(ENAMETOOLONG));
1127 
1128 	if (dataset_nestcheck(doca->doca_name) != 0)
1129 		return (SET_ERROR(ENAMETOOLONG));
1130 
1131 	error = dsl_dir_hold(dp, doca->doca_name, FTAG, &pdd, &tail);
1132 	if (error != 0)
1133 		return (error);
1134 	if (tail == NULL) {
1135 		dsl_dir_rele(pdd, FTAG);
1136 		return (SET_ERROR(EEXIST));
1137 	}
1138 
1139 	error = dmu_objset_create_crypt_check(pdd, doca->doca_dcp, NULL);
1140 	if (error != 0) {
1141 		dsl_dir_rele(pdd, FTAG);
1142 		return (error);
1143 	}
1144 
1145 	error = dsl_fs_ss_limit_check(pdd, 1, ZFS_PROP_FILESYSTEM_LIMIT, NULL,
1146 	    doca->doca_cred);
1147 
1148 	dsl_dir_rele(pdd, FTAG);
1149 
1150 	return (error);
1151 }
1152 
1153 static void
1154 dmu_objset_create_sync(void *arg, dmu_tx_t *tx)
1155 {
1156 	dmu_objset_create_arg_t *doca = arg;
1157 	dsl_pool_t *dp = dmu_tx_pool(tx);
1158 	spa_t *spa = dp->dp_spa;
1159 	dsl_dir_t *pdd;
1160 	const char *tail;
1161 	dsl_dataset_t *ds;
1162 	uint64_t obj;
1163 	blkptr_t *bp;
1164 	objset_t *os;
1165 	zio_t *rzio;
1166 
1167 	VERIFY0(dsl_dir_hold(dp, doca->doca_name, FTAG, &pdd, &tail));
1168 
1169 	obj = dsl_dataset_create_sync(pdd, tail, NULL, doca->doca_flags,
1170 	    doca->doca_cred, doca->doca_dcp, tx);
1171 
1172 	VERIFY0(dsl_dataset_hold_obj_flags(pdd->dd_pool, obj,
1173 	    DS_HOLD_FLAG_DECRYPT, FTAG, &ds));
1174 	rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
1175 	bp = dsl_dataset_get_blkptr(ds);
1176 	os = dmu_objset_create_impl(spa, ds, bp, doca->doca_type, tx);
1177 	rrw_exit(&ds->ds_bp_rwlock, FTAG);
1178 
1179 	if (doca->doca_userfunc != NULL) {
1180 		doca->doca_userfunc(os, doca->doca_userarg,
1181 		    doca->doca_cred, tx);
1182 	}
1183 
1184 	/*
1185 	 * The doca_userfunc() may write out some data that needs to be
1186 	 * encrypted if the dataset is encrypted (specifically the root
1187 	 * directory).  This data must be written out before the encryption
1188 	 * key mapping is removed by dsl_dataset_rele_flags().  Force the
1189 	 * I/O to occur immediately by invoking the relevant sections of
1190 	 * dsl_pool_sync().
1191 	 */
1192 	if (os->os_encrypted) {
1193 		dsl_dataset_t *tmpds = NULL;
1194 		boolean_t need_sync_done = B_FALSE;
1195 
1196 		mutex_enter(&ds->ds_lock);
1197 		ds->ds_owner = FTAG;
1198 		mutex_exit(&ds->ds_lock);
1199 
1200 		rzio = zio_root(spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1201 		tmpds = txg_list_remove_this(&dp->dp_dirty_datasets, ds,
1202 		    tx->tx_txg);
1203 		if (tmpds != NULL) {
1204 			dsl_dataset_sync(ds, rzio, tx);
1205 			need_sync_done = B_TRUE;
1206 		}
1207 		VERIFY0(zio_wait(rzio));
1208 		dmu_objset_do_userquota_updates(os, tx);
1209 		taskq_wait(dp->dp_sync_taskq);
1210 		if (txg_list_member(&dp->dp_dirty_datasets, ds, tx->tx_txg)) {
1211 			ASSERT3P(ds->ds_key_mapping, !=, NULL);
1212 			key_mapping_rele(spa, ds->ds_key_mapping, ds);
1213 		}
1214 
1215 		rzio = zio_root(spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1216 		tmpds = txg_list_remove_this(&dp->dp_dirty_datasets, ds,
1217 		    tx->tx_txg);
1218 		if (tmpds != NULL) {
1219 			dmu_buf_rele(ds->ds_dbuf, ds);
1220 			dsl_dataset_sync(ds, rzio, tx);
1221 		}
1222 		VERIFY0(zio_wait(rzio));
1223 
1224 		if (need_sync_done) {
1225 			ASSERT3P(ds->ds_key_mapping, !=, NULL);
1226 			key_mapping_rele(spa, ds->ds_key_mapping, ds);
1227 			dsl_dataset_sync_done(ds, tx);
1228 		}
1229 
1230 		mutex_enter(&ds->ds_lock);
1231 		ds->ds_owner = NULL;
1232 		mutex_exit(&ds->ds_lock);
1233 	}
1234 
1235 	spa_history_log_internal_ds(ds, "create", tx, "");
1236 	dsl_dataset_rele_flags(ds, DS_HOLD_FLAG_DECRYPT, FTAG);
1237 	dsl_dir_rele(pdd, FTAG);
1238 }
1239 
1240 int
1241 dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
1242     dsl_crypto_params_t *dcp, dmu_objset_create_sync_func_t func, void *arg)
1243 {
1244 	dmu_objset_create_arg_t doca;
1245 	dsl_crypto_params_t tmp_dcp = { 0 };
1246 
1247 	doca.doca_name = name;
1248 	doca.doca_cred = CRED();
1249 	doca.doca_flags = flags;
1250 	doca.doca_userfunc = func;
1251 	doca.doca_userarg = arg;
1252 	doca.doca_type = type;
1253 
1254 	/*
1255 	 * Some callers (mostly for testing) do not provide a dcp on their
1256 	 * own but various code inside the sync task will require it to be
1257 	 * allocated. Rather than adding NULL checks throughout this code
1258 	 * or adding dummy dcp's to all of the callers we simply create a
1259 	 * dummy one here and use that. This zero dcp will have the same
1260 	 * effect as asking for inheritence of all encryption params.
1261 	 */
1262 	doca.doca_dcp = (dcp != NULL) ? dcp : &tmp_dcp;
1263 
1264 	return (dsl_sync_task(name,
1265 	    dmu_objset_create_check, dmu_objset_create_sync, &doca,
1266 	    6, ZFS_SPACE_CHECK_NORMAL));
1267 }
1268 
1269 typedef struct dmu_objset_clone_arg {
1270 	const char *doca_clone;
1271 	const char *doca_origin;
1272 	cred_t *doca_cred;
1273 } dmu_objset_clone_arg_t;
1274 
1275 /*ARGSUSED*/
1276 static int
1277 dmu_objset_clone_check(void *arg, dmu_tx_t *tx)
1278 {
1279 	dmu_objset_clone_arg_t *doca = arg;
1280 	dsl_dir_t *pdd;
1281 	const char *tail;
1282 	int error;
1283 	dsl_dataset_t *origin;
1284 	dsl_pool_t *dp = dmu_tx_pool(tx);
1285 
1286 	if (strchr(doca->doca_clone, '@') != NULL)
1287 		return (SET_ERROR(EINVAL));
1288 
1289 	if (strlen(doca->doca_clone) >= ZFS_MAX_DATASET_NAME_LEN)
1290 		return (SET_ERROR(ENAMETOOLONG));
1291 
1292 	error = dsl_dir_hold(dp, doca->doca_clone, FTAG, &pdd, &tail);
1293 	if (error != 0)
1294 		return (error);
1295 	if (tail == NULL) {
1296 		dsl_dir_rele(pdd, FTAG);
1297 		return (SET_ERROR(EEXIST));
1298 	}
1299 
1300 	error = dsl_fs_ss_limit_check(pdd, 1, ZFS_PROP_FILESYSTEM_LIMIT, NULL,
1301 	    doca->doca_cred);
1302 	if (error != 0) {
1303 		dsl_dir_rele(pdd, FTAG);
1304 		return (SET_ERROR(EDQUOT));
1305 	}
1306 
1307 	error = dsl_dataset_hold(dp, doca->doca_origin, FTAG, &origin);
1308 	if (error != 0) {
1309 		dsl_dir_rele(pdd, FTAG);
1310 		return (error);
1311 	}
1312 
1313 	/* You can only clone snapshots, not the head datasets. */
1314 	if (!origin->ds_is_snapshot) {
1315 		dsl_dataset_rele(origin, FTAG);
1316 		dsl_dir_rele(pdd, FTAG);
1317 		return (SET_ERROR(EINVAL));
1318 	}
1319 
1320 	dsl_dataset_rele(origin, FTAG);
1321 	dsl_dir_rele(pdd, FTAG);
1322 
1323 	return (0);
1324 }
1325 
1326 static void
1327 dmu_objset_clone_sync(void *arg, dmu_tx_t *tx)
1328 {
1329 	dmu_objset_clone_arg_t *doca = arg;
1330 	dsl_pool_t *dp = dmu_tx_pool(tx);
1331 	dsl_dir_t *pdd;
1332 	const char *tail;
1333 	dsl_dataset_t *origin, *ds;
1334 	uint64_t obj;
1335 	char namebuf[ZFS_MAX_DATASET_NAME_LEN];
1336 
1337 	VERIFY0(dsl_dir_hold(dp, doca->doca_clone, FTAG, &pdd, &tail));
1338 	VERIFY0(dsl_dataset_hold(dp, doca->doca_origin, FTAG, &origin));
1339 
1340 	obj = dsl_dataset_create_sync(pdd, tail, origin, 0,
1341 	    doca->doca_cred, NULL, tx);
1342 
1343 	VERIFY0(dsl_dataset_hold_obj(pdd->dd_pool, obj, FTAG, &ds));
1344 	dsl_dataset_name(origin, namebuf);
1345 	spa_history_log_internal_ds(ds, "clone", tx,
1346 	    "origin=%s (%llu)", namebuf, origin->ds_object);
1347 	dsl_dataset_rele(ds, FTAG);
1348 	dsl_dataset_rele(origin, FTAG);
1349 	dsl_dir_rele(pdd, FTAG);
1350 }
1351 
1352 int
1353 dmu_objset_clone(const char *clone, const char *origin)
1354 {
1355 	dmu_objset_clone_arg_t doca;
1356 
1357 	doca.doca_clone = clone;
1358 	doca.doca_origin = origin;
1359 	doca.doca_cred = CRED();
1360 
1361 	return (dsl_sync_task(clone,
1362 	    dmu_objset_clone_check, dmu_objset_clone_sync, &doca,
1363 	    6, ZFS_SPACE_CHECK_NORMAL));
1364 }
1365 
1366 static int
1367 dmu_objset_remap_indirects_impl(objset_t *os, uint64_t last_removed_txg)
1368 {
1369 	int error = 0;
1370 	uint64_t object = 0;
1371 	while ((error = dmu_object_next(os, &object, B_FALSE, 0)) == 0) {
1372 		error = dmu_object_remap_indirects(os, object,
1373 		    last_removed_txg);
1374 		/*
1375 		 * If the ZPL removed the object before we managed to dnode_hold
1376 		 * it, we would get an ENOENT. If the ZPL declares its intent
1377 		 * to remove the object (dnode_free) before we manage to
1378 		 * dnode_hold it, we would get an EEXIST. In either case, we
1379 		 * want to continue remapping the other objects in the objset;
1380 		 * in all other cases, we want to break early.
1381 		 */
1382 		if (error != 0 && error != ENOENT && error != EEXIST) {
1383 			break;
1384 		}
1385 	}
1386 	if (error == ESRCH) {
1387 		error = 0;
1388 	}
1389 	return (error);
1390 }
1391 
1392 int
1393 dmu_objset_remap_indirects(const char *fsname)
1394 {
1395 	int error = 0;
1396 	objset_t *os = NULL;
1397 	uint64_t last_removed_txg;
1398 	uint64_t remap_start_txg;
1399 	dsl_dir_t *dd;
1400 
1401 	error = dmu_objset_hold(fsname, FTAG, &os);
1402 	if (error != 0) {
1403 		return (error);
1404 	}
1405 	dd = dmu_objset_ds(os)->ds_dir;
1406 
1407 	if (!spa_feature_is_enabled(dmu_objset_spa(os),
1408 	    SPA_FEATURE_OBSOLETE_COUNTS)) {
1409 		dmu_objset_rele(os, FTAG);
1410 		return (SET_ERROR(ENOTSUP));
1411 	}
1412 
1413 	if (dsl_dataset_is_snapshot(dmu_objset_ds(os))) {
1414 		dmu_objset_rele(os, FTAG);
1415 		return (SET_ERROR(EINVAL));
1416 	}
1417 
1418 	/*
1419 	 * If there has not been a removal, we're done.
1420 	 */
1421 	last_removed_txg = spa_get_last_removal_txg(dmu_objset_spa(os));
1422 	if (last_removed_txg == -1ULL) {
1423 		dmu_objset_rele(os, FTAG);
1424 		return (0);
1425 	}
1426 
1427 	/*
1428 	 * If we have remapped since the last removal, we're done.
1429 	 */
1430 	if (dsl_dir_is_zapified(dd)) {
1431 		uint64_t last_remap_txg;
1432 		if (zap_lookup(spa_meta_objset(dmu_objset_spa(os)),
1433 		    dd->dd_object, DD_FIELD_LAST_REMAP_TXG,
1434 		    sizeof (last_remap_txg), 1, &last_remap_txg) == 0 &&
1435 		    last_remap_txg > last_removed_txg) {
1436 			dmu_objset_rele(os, FTAG);
1437 			return (0);
1438 		}
1439 	}
1440 
1441 	dsl_dataset_long_hold(dmu_objset_ds(os), FTAG);
1442 	dsl_pool_rele(dmu_objset_pool(os), FTAG);
1443 
1444 	remap_start_txg = spa_last_synced_txg(dmu_objset_spa(os));
1445 	error = dmu_objset_remap_indirects_impl(os, last_removed_txg);
1446 	if (error == 0) {
1447 		/*
1448 		 * We update the last_remap_txg to be the start txg so that
1449 		 * we can guarantee that every block older than last_remap_txg
1450 		 * that can be remapped has been remapped.
1451 		 */
1452 		error = dsl_dir_update_last_remap_txg(dd, remap_start_txg);
1453 	}
1454 
1455 	dsl_dataset_long_rele(dmu_objset_ds(os), FTAG);
1456 	dsl_dataset_rele(dmu_objset_ds(os), FTAG);
1457 
1458 	return (error);
1459 }
1460 
1461 int
1462 dmu_objset_snapshot_one(const char *fsname, const char *snapname)
1463 {
1464 	int err;
1465 	char *longsnap = kmem_asprintf("%s@%s", fsname, snapname);
1466 	nvlist_t *snaps = fnvlist_alloc();
1467 
1468 	fnvlist_add_boolean(snaps, longsnap);
1469 	strfree(longsnap);
1470 	err = dsl_dataset_snapshot(snaps, NULL, NULL);
1471 	fnvlist_free(snaps);
1472 	return (err);
1473 }
1474 
1475 static void
1476 dmu_objset_upgrade_task_cb(void *data)
1477 {
1478 	objset_t *os = data;
1479 
1480 	mutex_enter(&os->os_upgrade_lock);
1481 	os->os_upgrade_status = EINTR;
1482 	if (!os->os_upgrade_exit) {
1483 		int status;
1484 
1485 		mutex_exit(&os->os_upgrade_lock);
1486 
1487 		status = os->os_upgrade_cb(os);
1488 
1489 		mutex_enter(&os->os_upgrade_lock);
1490 
1491 		os->os_upgrade_status = status;
1492 	}
1493 	os->os_upgrade_exit = B_TRUE;
1494 	os->os_upgrade_id = 0;
1495 	mutex_exit(&os->os_upgrade_lock);
1496 	dsl_dataset_long_rele(dmu_objset_ds(os), upgrade_tag);
1497 }
1498 
1499 static void
1500 dmu_objset_upgrade(objset_t *os, dmu_objset_upgrade_cb_t cb)
1501 {
1502 	if (os->os_upgrade_id != 0)
1503 		return;
1504 
1505 	ASSERT(dsl_pool_config_held(dmu_objset_pool(os)));
1506 	dsl_dataset_long_hold(dmu_objset_ds(os), upgrade_tag);
1507 
1508 	mutex_enter(&os->os_upgrade_lock);
1509 	if (os->os_upgrade_id == 0 && os->os_upgrade_status == 0) {
1510 		os->os_upgrade_exit = B_FALSE;
1511 		os->os_upgrade_cb = cb;
1512 		os->os_upgrade_id = taskq_dispatch(
1513 		    os->os_spa->spa_upgrade_taskq,
1514 		    dmu_objset_upgrade_task_cb, os, TQ_SLEEP);
1515 		if (os->os_upgrade_id == TASKQID_INVALID) {
1516 			dsl_dataset_long_rele(dmu_objset_ds(os), upgrade_tag);
1517 			os->os_upgrade_status = ENOMEM;
1518 		}
1519 	} else {
1520 		dsl_dataset_long_rele(dmu_objset_ds(os), upgrade_tag);
1521 	}
1522 	mutex_exit(&os->os_upgrade_lock);
1523 }
1524 
1525 static void
1526 dmu_objset_upgrade_stop(objset_t *os)
1527 {
1528 	mutex_enter(&os->os_upgrade_lock);
1529 	os->os_upgrade_exit = B_TRUE;
1530 	if (os->os_upgrade_id != 0) {
1531 		taskqid_t tid = os->os_upgrade_id;
1532 
1533 		mutex_exit(&os->os_upgrade_lock);
1534 
1535 		taskq_wait_id(os->os_spa->spa_upgrade_taskq, tid);
1536 		txg_wait_synced(os->os_spa->spa_dsl_pool, 0);
1537 	} else {
1538 		mutex_exit(&os->os_upgrade_lock);
1539 	}
1540 }
1541 
1542 static void
1543 dmu_objset_sync_dnodes(multilist_sublist_t *list, dmu_tx_t *tx)
1544 {
1545 	dnode_t *dn;
1546 
1547 	while ((dn = multilist_sublist_head(list)) != NULL) {
1548 		ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
1549 		ASSERT(dn->dn_dbuf->db_data_pending);
1550 		/*
1551 		 * Initialize dn_zio outside dnode_sync() because the
1552 		 * meta-dnode needs to set it outside dnode_sync().
1553 		 */
1554 		dn->dn_zio = dn->dn_dbuf->db_data_pending->dr_zio;
1555 		ASSERT(dn->dn_zio);
1556 
1557 		ASSERT3U(dn->dn_nlevels, <=, DN_MAX_LEVELS);
1558 		multilist_sublist_remove(list, dn);
1559 
1560 		/*
1561 		 * If we are not doing useraccounting (os_synced_dnodes == NULL)
1562 		 * we are done with this dnode for this txg. Unset dn_dirty_txg
1563 		 * if later txgs aren't dirtying it so that future holders do
1564 		 * not get a stale value. Otherwise, we will do this in
1565 		 * userquota_updates_task() when processing has completely
1566 		 * finished for this txg.
1567 		 */
1568 		multilist_t *newlist = dn->dn_objset->os_synced_dnodes;
1569 		if (newlist != NULL) {
1570 			(void) dnode_add_ref(dn, newlist);
1571 			multilist_insert(newlist, dn);
1572 		} else {
1573 			mutex_enter(&dn->dn_mtx);
1574 			if (dn->dn_dirty_txg == tx->tx_txg)
1575 				dn->dn_dirty_txg = 0;
1576 			mutex_exit(&dn->dn_mtx);
1577 		}
1578 
1579 		dnode_sync(dn, tx);
1580 	}
1581 }
1582 
1583 /* ARGSUSED */
1584 static void
1585 dmu_objset_write_ready(zio_t *zio, arc_buf_t *abuf, void *arg)
1586 {
1587 	blkptr_t *bp = zio->io_bp;
1588 	objset_t *os = arg;
1589 	dnode_phys_t *dnp = &os->os_phys->os_meta_dnode;
1590 	uint64_t fill = 0;
1591 
1592 	ASSERT(!BP_IS_EMBEDDED(bp));
1593 	ASSERT3U(BP_GET_TYPE(bp), ==, DMU_OT_OBJSET);
1594 
1595 	/*
1596 	 * Update rootbp fill count: it should be the number of objects
1597 	 * allocated in the object set (not counting the "special"
1598 	 * objects that are stored in the objset_phys_t -- the meta
1599 	 * dnode and user/group/project accounting objects).
1600 	 */
1601 	for (int i = 0; i < dnp->dn_nblkptr; i++)
1602 		fill += BP_GET_FILL(&dnp->dn_blkptr[i]);
1603 
1604 	BP_SET_FILL(bp, fill);
1605 
1606 	if (os->os_dsl_dataset != NULL)
1607 		rrw_enter(&os->os_dsl_dataset->ds_bp_rwlock, RW_WRITER, FTAG);
1608 	*os->os_rootbp = *bp;
1609 	if (os->os_dsl_dataset != NULL)
1610 		rrw_exit(&os->os_dsl_dataset->ds_bp_rwlock, FTAG);
1611 }
1612 
1613 /* ARGSUSED */
1614 static void
1615 dmu_objset_write_done(zio_t *zio, arc_buf_t *abuf, void *arg)
1616 {
1617 	blkptr_t *bp = zio->io_bp;
1618 	blkptr_t *bp_orig = &zio->io_bp_orig;
1619 	objset_t *os = arg;
1620 
1621 	if (zio->io_flags & ZIO_FLAG_IO_REWRITE) {
1622 		ASSERT(BP_EQUAL(bp, bp_orig));
1623 	} else {
1624 		dsl_dataset_t *ds = os->os_dsl_dataset;
1625 		dmu_tx_t *tx = os->os_synctx;
1626 
1627 		(void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE);
1628 		dsl_dataset_block_born(ds, bp, tx);
1629 	}
1630 	kmem_free(bp, sizeof (*bp));
1631 }
1632 
1633 typedef struct sync_dnodes_arg {
1634 	multilist_t *sda_list;
1635 	int sda_sublist_idx;
1636 	multilist_t *sda_newlist;
1637 	dmu_tx_t *sda_tx;
1638 } sync_dnodes_arg_t;
1639 
1640 static void
1641 sync_dnodes_task(void *arg)
1642 {
1643 	sync_dnodes_arg_t *sda = arg;
1644 
1645 	multilist_sublist_t *ms =
1646 	    multilist_sublist_lock(sda->sda_list, sda->sda_sublist_idx);
1647 
1648 	dmu_objset_sync_dnodes(ms, sda->sda_tx);
1649 
1650 	multilist_sublist_unlock(ms);
1651 
1652 	kmem_free(sda, sizeof (*sda));
1653 }
1654 
1655 
1656 /* called from dsl */
1657 void
1658 dmu_objset_sync(objset_t *os, zio_t *pio, dmu_tx_t *tx)
1659 {
1660 	int txgoff;
1661 	zbookmark_phys_t zb;
1662 	zio_prop_t zp;
1663 	zio_t *zio;
1664 	list_t *list;
1665 	dbuf_dirty_record_t *dr;
1666 	blkptr_t *blkptr_copy = kmem_alloc(sizeof (*os->os_rootbp), KM_SLEEP);
1667 	*blkptr_copy = *os->os_rootbp;
1668 
1669 	dprintf_ds(os->os_dsl_dataset, "txg=%llu\n", tx->tx_txg);
1670 
1671 	ASSERT(dmu_tx_is_syncing(tx));
1672 	/* XXX the write_done callback should really give us the tx... */
1673 	os->os_synctx = tx;
1674 
1675 	if (os->os_dsl_dataset == NULL) {
1676 		/*
1677 		 * This is the MOS.  If we have upgraded,
1678 		 * spa_max_replication() could change, so reset
1679 		 * os_copies here.
1680 		 */
1681 		os->os_copies = spa_max_replication(os->os_spa);
1682 	}
1683 
1684 	/*
1685 	 * Create the root block IO
1686 	 */
1687 	SET_BOOKMARK(&zb, os->os_dsl_dataset ?
1688 	    os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
1689 	    ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
1690 	arc_release(os->os_phys_buf, &os->os_phys_buf);
1691 
1692 	dmu_write_policy(os, NULL, 0, 0, &zp);
1693 
1694 	/*
1695 	 * If we are either claiming the ZIL or doing a raw receive, write
1696 	 * out the os_phys_buf raw. Neither of these actions will effect the
1697 	 * MAC at this point.
1698 	 */
1699 	if (os->os_raw_receive ||
1700 	    os->os_next_write_raw[tx->tx_txg & TXG_MASK]) {
1701 		ASSERT(os->os_encrypted);
1702 		arc_convert_to_raw(os->os_phys_buf,
1703 		    os->os_dsl_dataset->ds_object, ZFS_HOST_BYTEORDER,
1704 		    DMU_OT_OBJSET, NULL, NULL, NULL);
1705 	}
1706 
1707 	zio = arc_write(pio, os->os_spa, tx->tx_txg,
1708 	    blkptr_copy, os->os_phys_buf, DMU_OS_IS_L2CACHEABLE(os),
1709 	    &zp, dmu_objset_write_ready, NULL, NULL, dmu_objset_write_done,
1710 	    os, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
1711 
1712 	/*
1713 	 * Sync special dnodes - the parent IO for the sync is the root block
1714 	 */
1715 	DMU_META_DNODE(os)->dn_zio = zio;
1716 	dnode_sync(DMU_META_DNODE(os), tx);
1717 
1718 	os->os_phys->os_flags = os->os_flags;
1719 
1720 	if (DMU_USERUSED_DNODE(os) &&
1721 	    DMU_USERUSED_DNODE(os)->dn_type != DMU_OT_NONE) {
1722 		DMU_USERUSED_DNODE(os)->dn_zio = zio;
1723 		dnode_sync(DMU_USERUSED_DNODE(os), tx);
1724 		DMU_GROUPUSED_DNODE(os)->dn_zio = zio;
1725 		dnode_sync(DMU_GROUPUSED_DNODE(os), tx);
1726 	}
1727 
1728 	if (DMU_PROJECTUSED_DNODE(os) &&
1729 	    DMU_PROJECTUSED_DNODE(os)->dn_type != DMU_OT_NONE) {
1730 		DMU_PROJECTUSED_DNODE(os)->dn_zio = zio;
1731 		dnode_sync(DMU_PROJECTUSED_DNODE(os), tx);
1732 	}
1733 
1734 	txgoff = tx->tx_txg & TXG_MASK;
1735 
1736 	if (dmu_objset_userused_enabled(os) &&
1737 	    (!os->os_encrypted || !dmu_objset_is_receiving(os))) {
1738 		/*
1739 		 * We must create the list here because it uses the
1740 		 * dn_dirty_link[] of this txg.  But it may already
1741 		 * exist because we call dsl_dataset_sync() twice per txg.
1742 		 */
1743 		if (os->os_synced_dnodes == NULL) {
1744 			os->os_synced_dnodes =
1745 			    multilist_create(sizeof (dnode_t),
1746 			    offsetof(dnode_t, dn_dirty_link[txgoff]),
1747 			    dnode_multilist_index_func);
1748 		} else {
1749 			ASSERT3U(os->os_synced_dnodes->ml_offset, ==,
1750 			    offsetof(dnode_t, dn_dirty_link[txgoff]));
1751 		}
1752 	}
1753 
1754 	for (int i = 0;
1755 	    i < multilist_get_num_sublists(os->os_dirty_dnodes[txgoff]); i++) {
1756 		sync_dnodes_arg_t *sda = kmem_alloc(sizeof (*sda), KM_SLEEP);
1757 		sda->sda_list = os->os_dirty_dnodes[txgoff];
1758 		sda->sda_sublist_idx = i;
1759 		sda->sda_tx = tx;
1760 		(void) taskq_dispatch(dmu_objset_pool(os)->dp_sync_taskq,
1761 		    sync_dnodes_task, sda, 0);
1762 		/* callback frees sda */
1763 	}
1764 	taskq_wait(dmu_objset_pool(os)->dp_sync_taskq);
1765 
1766 	list = &DMU_META_DNODE(os)->dn_dirty_records[txgoff];
1767 	while ((dr = list_head(list)) != NULL) {
1768 		ASSERT0(dr->dr_dbuf->db_level);
1769 		list_remove(list, dr);
1770 		if (dr->dr_zio)
1771 			zio_nowait(dr->dr_zio);
1772 	}
1773 
1774 	/* Enable dnode backfill if enough objects have been freed. */
1775 	if (os->os_freed_dnodes >= dmu_rescan_dnode_threshold) {
1776 		os->os_rescan_dnodes = B_TRUE;
1777 		os->os_freed_dnodes = 0;
1778 	}
1779 
1780 	/*
1781 	 * Free intent log blocks up to this tx.
1782 	 */
1783 	zil_sync(os->os_zil, tx);
1784 	os->os_phys->os_zil_header = os->os_zil_header;
1785 	zio_nowait(zio);
1786 }
1787 
1788 boolean_t
1789 dmu_objset_is_dirty(objset_t *os, uint64_t txg)
1790 {
1791 	return (!multilist_is_empty(os->os_dirty_dnodes[txg & TXG_MASK]));
1792 }
1793 
1794 static objset_used_cb_t *used_cbs[DMU_OST_NUMTYPES];
1795 
1796 void
1797 dmu_objset_register_type(dmu_objset_type_t ost, objset_used_cb_t *cb)
1798 {
1799 	used_cbs[ost] = cb;
1800 }
1801 
1802 boolean_t
1803 dmu_objset_userused_enabled(objset_t *os)
1804 {
1805 	return (spa_version(os->os_spa) >= SPA_VERSION_USERSPACE &&
1806 	    used_cbs[os->os_phys->os_type] != NULL &&
1807 	    DMU_USERUSED_DNODE(os) != NULL);
1808 }
1809 
1810 boolean_t
1811 dmu_objset_userobjused_enabled(objset_t *os)
1812 {
1813 	return (dmu_objset_userused_enabled(os) &&
1814 	    spa_feature_is_enabled(os->os_spa, SPA_FEATURE_USEROBJ_ACCOUNTING));
1815 }
1816 
1817 boolean_t
1818 dmu_objset_projectquota_enabled(objset_t *os)
1819 {
1820 	return (used_cbs[os->os_phys->os_type] != NULL &&
1821 	    DMU_PROJECTUSED_DNODE(os) != NULL &&
1822 	    spa_feature_is_enabled(os->os_spa, SPA_FEATURE_PROJECT_QUOTA));
1823 }
1824 
1825 typedef struct userquota_node {
1826 	/* must be in the first field, see userquota_update_cache() */
1827 	char		uqn_id[20 + DMU_OBJACCT_PREFIX_LEN];
1828 	int64_t		uqn_delta;
1829 	avl_node_t	uqn_node;
1830 } userquota_node_t;
1831 
1832 typedef struct userquota_cache {
1833 	avl_tree_t uqc_user_deltas;
1834 	avl_tree_t uqc_group_deltas;
1835 	avl_tree_t uqc_project_deltas;
1836 } userquota_cache_t;
1837 
1838 static int
1839 userquota_compare(const void *l, const void *r)
1840 {
1841 	const userquota_node_t *luqn = l;
1842 	const userquota_node_t *ruqn = r;
1843 	int rv;
1844 
1845 	/*
1846 	 * NB: can only access uqn_id because userquota_update_cache() doesn't
1847 	 * pass in an entire userquota_node_t.
1848 	 */
1849 	rv = strcmp(luqn->uqn_id, ruqn->uqn_id);
1850 
1851 	return (TREE_ISIGN(rv));
1852 }
1853 
1854 static void
1855 do_userquota_cacheflush(objset_t *os, userquota_cache_t *cache, dmu_tx_t *tx)
1856 {
1857 	void *cookie;
1858 	userquota_node_t *uqn;
1859 
1860 	ASSERT(dmu_tx_is_syncing(tx));
1861 
1862 	cookie = NULL;
1863 	while ((uqn = avl_destroy_nodes(&cache->uqc_user_deltas,
1864 	    &cookie)) != NULL) {
1865 		/*
1866 		 * os_userused_lock protects against concurrent calls to
1867 		 * zap_increment_int().  It's needed because zap_increment_int()
1868 		 * is not thread-safe (i.e. not atomic).
1869 		 */
1870 		mutex_enter(&os->os_userused_lock);
1871 		VERIFY0(zap_increment(os, DMU_USERUSED_OBJECT,
1872 		    uqn->uqn_id, uqn->uqn_delta, tx));
1873 		mutex_exit(&os->os_userused_lock);
1874 		kmem_free(uqn, sizeof (*uqn));
1875 	}
1876 	avl_destroy(&cache->uqc_user_deltas);
1877 
1878 	cookie = NULL;
1879 	while ((uqn = avl_destroy_nodes(&cache->uqc_group_deltas,
1880 	    &cookie)) != NULL) {
1881 		mutex_enter(&os->os_userused_lock);
1882 		VERIFY0(zap_increment(os, DMU_GROUPUSED_OBJECT,
1883 		    uqn->uqn_id, uqn->uqn_delta, tx));
1884 		mutex_exit(&os->os_userused_lock);
1885 		kmem_free(uqn, sizeof (*uqn));
1886 	}
1887 	avl_destroy(&cache->uqc_group_deltas);
1888 
1889 	if (dmu_objset_projectquota_enabled(os)) {
1890 		cookie = NULL;
1891 		while ((uqn = avl_destroy_nodes(&cache->uqc_project_deltas,
1892 		    &cookie)) != NULL) {
1893 			mutex_enter(&os->os_userused_lock);
1894 			VERIFY0(zap_increment(os, DMU_PROJECTUSED_OBJECT,
1895 			    uqn->uqn_id, uqn->uqn_delta, tx));
1896 			mutex_exit(&os->os_userused_lock);
1897 			kmem_free(uqn, sizeof (*uqn));
1898 		}
1899 		avl_destroy(&cache->uqc_project_deltas);
1900 	}
1901 }
1902 
1903 static void
1904 userquota_update_cache(avl_tree_t *avl, const char *id, int64_t delta)
1905 {
1906 	userquota_node_t *uqn;
1907 	avl_index_t idx;
1908 
1909 	ASSERT(strlen(id) < sizeof (uqn->uqn_id));
1910 	/*
1911 	 * Use id directly for searching because uqn_id is the first field of
1912 	 * userquota_node_t and fields after uqn_id won't be accessed in
1913 	 * avl_find().
1914 	 */
1915 	uqn = avl_find(avl, (const void *)id, &idx);
1916 	if (uqn == NULL) {
1917 		uqn = kmem_zalloc(sizeof (*uqn), KM_SLEEP);
1918 		(void) strlcpy(uqn->uqn_id, id, sizeof (uqn->uqn_id));
1919 		avl_insert(avl, uqn, idx);
1920 	}
1921 	uqn->uqn_delta += delta;
1922 }
1923 
1924 static void
1925 do_userquota_update(objset_t *os, userquota_cache_t *cache, uint64_t used,
1926     uint64_t flags, uint64_t user, uint64_t group, uint64_t project,
1927     boolean_t subtract)
1928 {
1929 	if ((flags & DNODE_FLAG_USERUSED_ACCOUNTED)) {
1930 		int64_t delta = DNODE_MIN_SIZE + used;
1931 		char name[20];
1932 
1933 		if (subtract)
1934 			delta = -delta;
1935 
1936 		(void) sprintf(name, "%llx", (longlong_t)user);
1937 		userquota_update_cache(&cache->uqc_user_deltas, name, delta);
1938 
1939 		(void) sprintf(name, "%llx", (longlong_t)group);
1940 		userquota_update_cache(&cache->uqc_group_deltas, name, delta);
1941 
1942 		if (dmu_objset_projectquota_enabled(os)) {
1943 			(void) sprintf(name, "%llx", (longlong_t)project);
1944 			userquota_update_cache(&cache->uqc_project_deltas,
1945 			    name, delta);
1946 		}
1947 	}
1948 }
1949 
1950 static void
1951 do_userobjquota_update(objset_t *os, userquota_cache_t *cache, uint64_t flags,
1952     uint64_t user, uint64_t group, uint64_t project, boolean_t subtract)
1953 {
1954 	if (flags & DNODE_FLAG_USEROBJUSED_ACCOUNTED) {
1955 		char name[20 + DMU_OBJACCT_PREFIX_LEN];
1956 		int delta = subtract ? -1 : 1;
1957 
1958 		(void) snprintf(name, sizeof (name), DMU_OBJACCT_PREFIX "%llx",
1959 		    (longlong_t)user);
1960 		userquota_update_cache(&cache->uqc_user_deltas, name, delta);
1961 
1962 		(void) snprintf(name, sizeof (name), DMU_OBJACCT_PREFIX "%llx",
1963 		    (longlong_t)group);
1964 		userquota_update_cache(&cache->uqc_group_deltas, name, delta);
1965 
1966 		if (dmu_objset_projectquota_enabled(os)) {
1967 			(void) snprintf(name, sizeof (name),
1968 			    DMU_OBJACCT_PREFIX "%llx", (longlong_t)project);
1969 			userquota_update_cache(&cache->uqc_project_deltas,
1970 			    name, delta);
1971 		}
1972 	}
1973 }
1974 
1975 typedef struct userquota_updates_arg {
1976 	objset_t *uua_os;
1977 	int uua_sublist_idx;
1978 	dmu_tx_t *uua_tx;
1979 } userquota_updates_arg_t;
1980 
1981 static void
1982 userquota_updates_task(void *arg)
1983 {
1984 	userquota_updates_arg_t *uua = arg;
1985 	objset_t *os = uua->uua_os;
1986 	dmu_tx_t *tx = uua->uua_tx;
1987 	dnode_t *dn;
1988 	userquota_cache_t cache = { 0 };
1989 
1990 	multilist_sublist_t *list =
1991 	    multilist_sublist_lock(os->os_synced_dnodes, uua->uua_sublist_idx);
1992 
1993 	ASSERT(multilist_sublist_head(list) == NULL ||
1994 	    dmu_objset_userused_enabled(os));
1995 	avl_create(&cache.uqc_user_deltas, userquota_compare,
1996 	    sizeof (userquota_node_t), offsetof(userquota_node_t, uqn_node));
1997 	avl_create(&cache.uqc_group_deltas, userquota_compare,
1998 	    sizeof (userquota_node_t), offsetof(userquota_node_t, uqn_node));
1999 	if (dmu_objset_projectquota_enabled(os))
2000 		avl_create(&cache.uqc_project_deltas, userquota_compare,
2001 		    sizeof (userquota_node_t), offsetof(userquota_node_t,
2002 		    uqn_node));
2003 
2004 	while ((dn = multilist_sublist_head(list)) != NULL) {
2005 		int flags;
2006 		ASSERT(!DMU_OBJECT_IS_SPECIAL(dn->dn_object));
2007 		ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE ||
2008 		    dn->dn_phys->dn_flags &
2009 		    DNODE_FLAG_USERUSED_ACCOUNTED);
2010 
2011 		flags = dn->dn_id_flags;
2012 		ASSERT(flags);
2013 		if (flags & DN_ID_OLD_EXIST)  {
2014 			do_userquota_update(os, &cache, dn->dn_oldused,
2015 			    dn->dn_oldflags, dn->dn_olduid, dn->dn_oldgid,
2016 			    dn->dn_oldprojid, B_TRUE);
2017 			do_userobjquota_update(os, &cache, dn->dn_oldflags,
2018 			    dn->dn_olduid, dn->dn_oldgid,
2019 			    dn->dn_oldprojid, B_TRUE);
2020 		}
2021 		if (flags & DN_ID_NEW_EXIST) {
2022 			do_userquota_update(os, &cache,
2023 			    DN_USED_BYTES(dn->dn_phys), dn->dn_phys->dn_flags,
2024 			    dn->dn_newuid, dn->dn_newgid,
2025 			    dn->dn_newprojid, B_FALSE);
2026 			do_userobjquota_update(os, &cache,
2027 			    dn->dn_phys->dn_flags, dn->dn_newuid, dn->dn_newgid,
2028 			    dn->dn_newprojid, B_FALSE);
2029 		}
2030 
2031 		mutex_enter(&dn->dn_mtx);
2032 		dn->dn_oldused = 0;
2033 		dn->dn_oldflags = 0;
2034 		if (dn->dn_id_flags & DN_ID_NEW_EXIST) {
2035 			dn->dn_olduid = dn->dn_newuid;
2036 			dn->dn_oldgid = dn->dn_newgid;
2037 			dn->dn_oldprojid = dn->dn_newprojid;
2038 			dn->dn_id_flags |= DN_ID_OLD_EXIST;
2039 			if (dn->dn_bonuslen == 0)
2040 				dn->dn_id_flags |= DN_ID_CHKED_SPILL;
2041 			else
2042 				dn->dn_id_flags |= DN_ID_CHKED_BONUS;
2043 		}
2044 		dn->dn_id_flags &= ~(DN_ID_NEW_EXIST);
2045 		if (dn->dn_dirty_txg == spa_syncing_txg(os->os_spa))
2046 			dn->dn_dirty_txg = 0;
2047 		mutex_exit(&dn->dn_mtx);
2048 
2049 		multilist_sublist_remove(list, dn);
2050 		dnode_rele(dn, os->os_synced_dnodes);
2051 	}
2052 	do_userquota_cacheflush(os, &cache, tx);
2053 	multilist_sublist_unlock(list);
2054 	kmem_free(uua, sizeof (*uua));
2055 }
2056 
2057 void
2058 dmu_objset_do_userquota_updates(objset_t *os, dmu_tx_t *tx)
2059 {
2060 	if (!dmu_objset_userused_enabled(os))
2061 		return;
2062 
2063 	/*
2064 	 * If this is a raw receive just return and handle accounting
2065 	 * later when we have the keys loaded. We also don't do user
2066 	 * accounting during claiming since the datasets are not owned
2067 	 * for the duration of claiming and this txg should only be
2068 	 * used for recovery.
2069 	 */
2070 	if (os->os_encrypted && dmu_objset_is_receiving(os))
2071 		return;
2072 
2073 	if (tx->tx_txg <= os->os_spa->spa_claim_max_txg)
2074 		return;
2075 
2076 	/* Allocate the user/group/project used objects if necessary. */
2077 	if (DMU_USERUSED_DNODE(os)->dn_type == DMU_OT_NONE) {
2078 		VERIFY0(zap_create_claim(os,
2079 		    DMU_USERUSED_OBJECT,
2080 		    DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx));
2081 		VERIFY0(zap_create_claim(os,
2082 		    DMU_GROUPUSED_OBJECT,
2083 		    DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx));
2084 	}
2085 
2086 	if (dmu_objset_projectquota_enabled(os) &&
2087 	    DMU_PROJECTUSED_DNODE(os)->dn_type == DMU_OT_NONE) {
2088 		VERIFY0(zap_create_claim(os, DMU_PROJECTUSED_OBJECT,
2089 		    DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx));
2090 	}
2091 
2092 	for (int i = 0;
2093 	    i < multilist_get_num_sublists(os->os_synced_dnodes); i++) {
2094 		userquota_updates_arg_t *uua =
2095 		    kmem_alloc(sizeof (*uua), KM_SLEEP);
2096 		uua->uua_os = os;
2097 		uua->uua_sublist_idx = i;
2098 		uua->uua_tx = tx;
2099 		/* note: caller does taskq_wait() */
2100 		(void) taskq_dispatch(dmu_objset_pool(os)->dp_sync_taskq,
2101 		    userquota_updates_task, uua, 0);
2102 		/* callback frees uua */
2103 	}
2104 }
2105 
2106 /*
2107  * Returns a pointer to data to find uid/gid from
2108  *
2109  * If a dirty record for transaction group that is syncing can't
2110  * be found then NULL is returned.  In the NULL case it is assumed
2111  * the uid/gid aren't changing.
2112  */
2113 static void *
2114 dmu_objset_userquota_find_data(dmu_buf_impl_t *db, dmu_tx_t *tx)
2115 {
2116 	dbuf_dirty_record_t *dr, **drp;
2117 	void *data;
2118 
2119 	if (db->db_dirtycnt == 0)
2120 		return (db->db.db_data);  /* Nothing is changing */
2121 
2122 	for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
2123 		if (dr->dr_txg == tx->tx_txg)
2124 			break;
2125 
2126 	if (dr == NULL) {
2127 		data = NULL;
2128 	} else {
2129 		dnode_t *dn;
2130 
2131 		DB_DNODE_ENTER(dr->dr_dbuf);
2132 		dn = DB_DNODE(dr->dr_dbuf);
2133 
2134 		if (dn->dn_bonuslen == 0 &&
2135 		    dr->dr_dbuf->db_blkid == DMU_SPILL_BLKID)
2136 			data = dr->dt.dl.dr_data->b_data;
2137 		else
2138 			data = dr->dt.dl.dr_data;
2139 
2140 		DB_DNODE_EXIT(dr->dr_dbuf);
2141 	}
2142 
2143 	return (data);
2144 }
2145 
2146 void
2147 dmu_objset_userquota_get_ids(dnode_t *dn, boolean_t before, dmu_tx_t *tx)
2148 {
2149 	objset_t *os = dn->dn_objset;
2150 	void *data = NULL;
2151 	dmu_buf_impl_t *db = NULL;
2152 	uint64_t *user = NULL;
2153 	uint64_t *group = NULL;
2154 	uint64_t *project = NULL;
2155 	int flags = dn->dn_id_flags;
2156 	int error;
2157 	boolean_t have_spill = B_FALSE;
2158 
2159 	if (!dmu_objset_userused_enabled(dn->dn_objset))
2160 		return;
2161 
2162 	/*
2163 	 * Raw receives introduce a problem with user accounting. Raw
2164 	 * receives cannot update the user accounting info because the
2165 	 * user ids and the sizes are encrypted. To guarantee that we
2166 	 * never end up with bad user accounting, we simply disable it
2167 	 * during raw receives. We also disable this for normal receives
2168 	 * so that an incremental raw receive may be done on top of an
2169 	 * existing non-raw receive.
2170 	 */
2171 	if (os->os_encrypted && dmu_objset_is_receiving(os))
2172 		return;
2173 
2174 	if (before && (flags & (DN_ID_CHKED_BONUS|DN_ID_OLD_EXIST|
2175 	    DN_ID_CHKED_SPILL)))
2176 		return;
2177 
2178 	if (before && dn->dn_bonuslen != 0)
2179 		data = DN_BONUS(dn->dn_phys);
2180 	else if (!before && dn->dn_bonuslen != 0) {
2181 		if (dn->dn_bonus) {
2182 			db = dn->dn_bonus;
2183 			mutex_enter(&db->db_mtx);
2184 			data = dmu_objset_userquota_find_data(db, tx);
2185 		} else {
2186 			data = DN_BONUS(dn->dn_phys);
2187 		}
2188 	} else if (dn->dn_bonuslen == 0 && dn->dn_bonustype == DMU_OT_SA) {
2189 			int rf = 0;
2190 
2191 			if (RW_WRITE_HELD(&dn->dn_struct_rwlock))
2192 				rf |= DB_RF_HAVESTRUCT;
2193 			error = dmu_spill_hold_by_dnode(dn,
2194 			    rf | DB_RF_MUST_SUCCEED,
2195 			    FTAG, (dmu_buf_t **)&db);
2196 			ASSERT(error == 0);
2197 			mutex_enter(&db->db_mtx);
2198 			data = (before) ? db->db.db_data :
2199 			    dmu_objset_userquota_find_data(db, tx);
2200 			have_spill = B_TRUE;
2201 	} else {
2202 		mutex_enter(&dn->dn_mtx);
2203 		dn->dn_id_flags |= DN_ID_CHKED_BONUS;
2204 		mutex_exit(&dn->dn_mtx);
2205 		return;
2206 	}
2207 
2208 	if (before) {
2209 		ASSERT(data);
2210 		user = &dn->dn_olduid;
2211 		group = &dn->dn_oldgid;
2212 		project = &dn->dn_oldprojid;
2213 	} else if (data) {
2214 		user = &dn->dn_newuid;
2215 		group = &dn->dn_newgid;
2216 		project = &dn->dn_newprojid;
2217 	}
2218 
2219 	/*
2220 	 * Must always call the callback in case the object
2221 	 * type has changed and that type isn't an object type to track
2222 	 */
2223 	error = used_cbs[os->os_phys->os_type](dn->dn_bonustype, data,
2224 	    user, group, project);
2225 
2226 	/*
2227 	 * Preserve existing uid/gid when the callback can't determine
2228 	 * what the new uid/gid are and the callback returned EEXIST.
2229 	 * The EEXIST error tells us to just use the existing uid/gid.
2230 	 * If we don't know what the old values are then just assign
2231 	 * them to 0, since that is a new file  being created.
2232 	 */
2233 	if (!before && data == NULL && error == EEXIST) {
2234 		if (flags & DN_ID_OLD_EXIST) {
2235 			dn->dn_newuid = dn->dn_olduid;
2236 			dn->dn_newgid = dn->dn_oldgid;
2237 			dn->dn_newprojid = dn->dn_oldprojid;
2238 		} else {
2239 			dn->dn_newuid = 0;
2240 			dn->dn_newgid = 0;
2241 			dn->dn_newprojid = ZFS_DEFAULT_PROJID;
2242 		}
2243 		error = 0;
2244 	}
2245 
2246 	if (db)
2247 		mutex_exit(&db->db_mtx);
2248 
2249 	mutex_enter(&dn->dn_mtx);
2250 	if (error == 0 && before)
2251 		dn->dn_id_flags |= DN_ID_OLD_EXIST;
2252 	if (error == 0 && !before)
2253 		dn->dn_id_flags |= DN_ID_NEW_EXIST;
2254 
2255 	if (have_spill) {
2256 		dn->dn_id_flags |= DN_ID_CHKED_SPILL;
2257 	} else {
2258 		dn->dn_id_flags |= DN_ID_CHKED_BONUS;
2259 	}
2260 	mutex_exit(&dn->dn_mtx);
2261 	if (have_spill)
2262 		dmu_buf_rele((dmu_buf_t *)db, FTAG);
2263 }
2264 
2265 boolean_t
2266 dmu_objset_userspace_present(objset_t *os)
2267 {
2268 	return (os->os_phys->os_flags &
2269 	    OBJSET_FLAG_USERACCOUNTING_COMPLETE);
2270 }
2271 
2272 boolean_t
2273 dmu_objset_userobjspace_present(objset_t *os)
2274 {
2275 	return (os->os_phys->os_flags &
2276 	    OBJSET_FLAG_USEROBJACCOUNTING_COMPLETE);
2277 }
2278 
2279 boolean_t
2280 dmu_objset_projectquota_present(objset_t *os)
2281 {
2282 	return (os->os_phys->os_flags &
2283 	    OBJSET_FLAG_PROJECTQUOTA_COMPLETE);
2284 }
2285 
2286 static int
2287 dmu_objset_space_upgrade(objset_t *os)
2288 {
2289 	uint64_t obj;
2290 	int err = 0;
2291 
2292 	/*
2293 	 * We simply need to mark every object dirty, so that it will be
2294 	 * synced out and now accounted.  If this is called
2295 	 * concurrently, or if we already did some work before crashing,
2296 	 * that's fine, since we track each object's accounted state
2297 	 * independently.
2298 	 */
2299 
2300 	for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 0)) {
2301 		dmu_tx_t *tx;
2302 		dmu_buf_t *db;
2303 		int objerr;
2304 
2305 		mutex_enter(&os->os_upgrade_lock);
2306 		if (os->os_upgrade_exit)
2307 			err = SET_ERROR(EINTR);
2308 		mutex_exit(&os->os_upgrade_lock);
2309 		if (err != 0)
2310 			return (err);
2311 
2312 		/*
2313 		 * The following is only valid on Linux since we cannot send
2314 		 * a signal to a kernel thread on illumos (because we have no
2315 		 * lwp and never return to user-land).
2316 		 *
2317 		 * if (issig(JUSTLOOKING) && issig(FORREAL))
2318 		 *    return (SET_ERROR(EINTR));
2319 		 */
2320 
2321 		objerr = dmu_bonus_hold(os, obj, FTAG, &db);
2322 		if (objerr != 0)
2323 			continue;
2324 		tx = dmu_tx_create(os);
2325 		dmu_tx_hold_bonus(tx, obj);
2326 		objerr = dmu_tx_assign(tx, TXG_WAIT);
2327 		if (objerr != 0) {
2328 			dmu_buf_rele(db, FTAG);
2329 			dmu_tx_abort(tx);
2330 			continue;
2331 		}
2332 		dmu_buf_will_dirty(db, tx);
2333 		dmu_buf_rele(db, FTAG);
2334 		dmu_tx_commit(tx);
2335 	}
2336 	return (0);
2337 }
2338 
2339 int
2340 dmu_objset_userspace_upgrade(objset_t *os)
2341 {
2342 	int err = 0;
2343 
2344 	if (dmu_objset_userspace_present(os))
2345 		return (0);
2346 	if (dmu_objset_is_snapshot(os))
2347 		return (SET_ERROR(EINVAL));
2348 	if (!dmu_objset_userused_enabled(os))
2349 		return (SET_ERROR(ENOTSUP));
2350 
2351 	err = dmu_objset_space_upgrade(os);
2352 	if (err)
2353 		return (err);
2354 
2355 	os->os_flags |= OBJSET_FLAG_USERACCOUNTING_COMPLETE;
2356 	txg_wait_synced(dmu_objset_pool(os), 0);
2357 	return (0);
2358 }
2359 
2360 static int
2361 dmu_objset_id_quota_upgrade_cb(objset_t *os)
2362 {
2363 	int err = 0;
2364 
2365 	if (dmu_objset_userobjspace_present(os) &&
2366 	    dmu_objset_projectquota_present(os))
2367 		return (0);
2368 	if (dmu_objset_is_snapshot(os))
2369 		return (SET_ERROR(EINVAL));
2370 	if (!dmu_objset_userobjused_enabled(os))
2371 		return (SET_ERROR(ENOTSUP));
2372 	if (!dmu_objset_projectquota_enabled(os) &&
2373 	    dmu_objset_userobjspace_present(os))
2374 		return (SET_ERROR(ENOTSUP));
2375 
2376 	dmu_objset_ds(os)->ds_feature_activation_needed[
2377 	    SPA_FEATURE_USEROBJ_ACCOUNTING] = B_TRUE;
2378 	if (dmu_objset_projectquota_enabled(os))
2379 		dmu_objset_ds(os)->ds_feature_activation_needed[
2380 		    SPA_FEATURE_PROJECT_QUOTA] = B_TRUE;
2381 
2382 	err = dmu_objset_space_upgrade(os);
2383 	if (err)
2384 		return (err);
2385 
2386 	os->os_flags |= OBJSET_FLAG_USEROBJACCOUNTING_COMPLETE;
2387 	if (dmu_objset_projectquota_enabled(os))
2388 		os->os_flags |= OBJSET_FLAG_PROJECTQUOTA_COMPLETE;
2389 
2390 	txg_wait_synced(dmu_objset_pool(os), 0);
2391 	return (0);
2392 }
2393 
2394 void
2395 dmu_objset_id_quota_upgrade(objset_t *os)
2396 {
2397 	dmu_objset_upgrade(os, dmu_objset_id_quota_upgrade_cb);
2398 }
2399 
2400 boolean_t
2401 dmu_objset_userobjspace_upgradable(objset_t *os)
2402 {
2403 	return (dmu_objset_type(os) == DMU_OST_ZFS &&
2404 	    !dmu_objset_is_snapshot(os) &&
2405 	    dmu_objset_userobjused_enabled(os) &&
2406 	    !dmu_objset_userobjspace_present(os) &&
2407 	    spa_writeable(dmu_objset_spa(os)));
2408 }
2409 
2410 boolean_t
2411 dmu_objset_projectquota_upgradable(objset_t *os)
2412 {
2413 	return (dmu_objset_type(os) == DMU_OST_ZFS &&
2414 	    !dmu_objset_is_snapshot(os) &&
2415 	    dmu_objset_projectquota_enabled(os) &&
2416 	    !dmu_objset_projectquota_present(os) &&
2417 	    spa_writeable(dmu_objset_spa(os)));
2418 }
2419 
2420 void
2421 dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
2422     uint64_t *usedobjsp, uint64_t *availobjsp)
2423 {
2424 	dsl_dataset_space(os->os_dsl_dataset, refdbytesp, availbytesp,
2425 	    usedobjsp, availobjsp);
2426 }
2427 
2428 uint64_t
2429 dmu_objset_fsid_guid(objset_t *os)
2430 {
2431 	return (dsl_dataset_fsid_guid(os->os_dsl_dataset));
2432 }
2433 
2434 void
2435 dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat)
2436 {
2437 	stat->dds_type = os->os_phys->os_type;
2438 	if (os->os_dsl_dataset)
2439 		dsl_dataset_fast_stat(os->os_dsl_dataset, stat);
2440 }
2441 
2442 void
2443 dmu_objset_stats(objset_t *os, nvlist_t *nv)
2444 {
2445 	ASSERT(os->os_dsl_dataset ||
2446 	    os->os_phys->os_type == DMU_OST_META);
2447 
2448 	if (os->os_dsl_dataset != NULL)
2449 		dsl_dataset_stats(os->os_dsl_dataset, nv);
2450 
2451 	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_TYPE,
2452 	    os->os_phys->os_type);
2453 	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERACCOUNTING,
2454 	    dmu_objset_userspace_present(os));
2455 }
2456 
2457 int
2458 dmu_objset_is_snapshot(objset_t *os)
2459 {
2460 	if (os->os_dsl_dataset != NULL)
2461 		return (os->os_dsl_dataset->ds_is_snapshot);
2462 	else
2463 		return (B_FALSE);
2464 }
2465 
2466 int
2467 dmu_snapshot_realname(objset_t *os, char *name, char *real, int maxlen,
2468     boolean_t *conflict)
2469 {
2470 	dsl_dataset_t *ds = os->os_dsl_dataset;
2471 	uint64_t ignored;
2472 
2473 	if (dsl_dataset_phys(ds)->ds_snapnames_zapobj == 0)
2474 		return (SET_ERROR(ENOENT));
2475 
2476 	return (zap_lookup_norm(ds->ds_dir->dd_pool->dp_meta_objset,
2477 	    dsl_dataset_phys(ds)->ds_snapnames_zapobj, name, 8, 1, &ignored,
2478 	    MT_NORMALIZE, real, maxlen, conflict));
2479 }
2480 
2481 int
2482 dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
2483     uint64_t *idp, uint64_t *offp, boolean_t *case_conflict)
2484 {
2485 	dsl_dataset_t *ds = os->os_dsl_dataset;
2486 	zap_cursor_t cursor;
2487 	zap_attribute_t attr;
2488 
2489 	ASSERT(dsl_pool_config_held(dmu_objset_pool(os)));
2490 
2491 	if (dsl_dataset_phys(ds)->ds_snapnames_zapobj == 0)
2492 		return (SET_ERROR(ENOENT));
2493 
2494 	zap_cursor_init_serialized(&cursor,
2495 	    ds->ds_dir->dd_pool->dp_meta_objset,
2496 	    dsl_dataset_phys(ds)->ds_snapnames_zapobj, *offp);
2497 
2498 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
2499 		zap_cursor_fini(&cursor);
2500 		return (SET_ERROR(ENOENT));
2501 	}
2502 
2503 	if (strlen(attr.za_name) + 1 > namelen) {
2504 		zap_cursor_fini(&cursor);
2505 		return (SET_ERROR(ENAMETOOLONG));
2506 	}
2507 
2508 	(void) strcpy(name, attr.za_name);
2509 	if (idp)
2510 		*idp = attr.za_first_integer;
2511 	if (case_conflict)
2512 		*case_conflict = attr.za_normalization_conflict;
2513 	zap_cursor_advance(&cursor);
2514 	*offp = zap_cursor_serialize(&cursor);
2515 	zap_cursor_fini(&cursor);
2516 
2517 	return (0);
2518 }
2519 
2520 int
2521 dmu_dir_list_next(objset_t *os, int namelen, char *name,
2522     uint64_t *idp, uint64_t *offp)
2523 {
2524 	dsl_dir_t *dd = os->os_dsl_dataset->ds_dir;
2525 	zap_cursor_t cursor;
2526 	zap_attribute_t attr;
2527 
2528 	/* there is no next dir on a snapshot! */
2529 	if (os->os_dsl_dataset->ds_object !=
2530 	    dsl_dir_phys(dd)->dd_head_dataset_obj)
2531 		return (SET_ERROR(ENOENT));
2532 
2533 	zap_cursor_init_serialized(&cursor,
2534 	    dd->dd_pool->dp_meta_objset,
2535 	    dsl_dir_phys(dd)->dd_child_dir_zapobj, *offp);
2536 
2537 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
2538 		zap_cursor_fini(&cursor);
2539 		return (SET_ERROR(ENOENT));
2540 	}
2541 
2542 	if (strlen(attr.za_name) + 1 > namelen) {
2543 		zap_cursor_fini(&cursor);
2544 		return (SET_ERROR(ENAMETOOLONG));
2545 	}
2546 
2547 	(void) strcpy(name, attr.za_name);
2548 	if (idp)
2549 		*idp = attr.za_first_integer;
2550 	zap_cursor_advance(&cursor);
2551 	*offp = zap_cursor_serialize(&cursor);
2552 	zap_cursor_fini(&cursor);
2553 
2554 	return (0);
2555 }
2556 
2557 typedef struct dmu_objset_find_ctx {
2558 	taskq_t		*dc_tq;
2559 	dsl_pool_t	*dc_dp;
2560 	uint64_t	dc_ddobj;
2561 	char		*dc_ddname; /* last component of ddobj's name */
2562 	int		(*dc_func)(dsl_pool_t *, dsl_dataset_t *, void *);
2563 	void		*dc_arg;
2564 	int		dc_flags;
2565 	kmutex_t	*dc_error_lock;
2566 	int		*dc_error;
2567 } dmu_objset_find_ctx_t;
2568 
2569 static void
2570 dmu_objset_find_dp_impl(dmu_objset_find_ctx_t *dcp)
2571 {
2572 	dsl_pool_t *dp = dcp->dc_dp;
2573 	dsl_dir_t *dd;
2574 	dsl_dataset_t *ds;
2575 	zap_cursor_t zc;
2576 	zap_attribute_t *attr;
2577 	uint64_t thisobj;
2578 	int err = 0;
2579 
2580 	/* don't process if there already was an error */
2581 	if (*dcp->dc_error != 0)
2582 		goto out;
2583 
2584 	/*
2585 	 * Note: passing the name (dc_ddname) here is optional, but it
2586 	 * improves performance because we don't need to call
2587 	 * zap_value_search() to determine the name.
2588 	 */
2589 	err = dsl_dir_hold_obj(dp, dcp->dc_ddobj, dcp->dc_ddname, FTAG, &dd);
2590 	if (err != 0)
2591 		goto out;
2592 
2593 	/* Don't visit hidden ($MOS & $ORIGIN) objsets. */
2594 	if (dd->dd_myname[0] == '$') {
2595 		dsl_dir_rele(dd, FTAG);
2596 		goto out;
2597 	}
2598 
2599 	thisobj = dsl_dir_phys(dd)->dd_head_dataset_obj;
2600 	attr = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
2601 
2602 	/*
2603 	 * Iterate over all children.
2604 	 */
2605 	if (dcp->dc_flags & DS_FIND_CHILDREN) {
2606 		for (zap_cursor_init(&zc, dp->dp_meta_objset,
2607 		    dsl_dir_phys(dd)->dd_child_dir_zapobj);
2608 		    zap_cursor_retrieve(&zc, attr) == 0;
2609 		    (void) zap_cursor_advance(&zc)) {
2610 			ASSERT3U(attr->za_integer_length, ==,
2611 			    sizeof (uint64_t));
2612 			ASSERT3U(attr->za_num_integers, ==, 1);
2613 
2614 			dmu_objset_find_ctx_t *child_dcp =
2615 			    kmem_alloc(sizeof (*child_dcp), KM_SLEEP);
2616 			*child_dcp = *dcp;
2617 			child_dcp->dc_ddobj = attr->za_first_integer;
2618 			child_dcp->dc_ddname = spa_strdup(attr->za_name);
2619 			if (dcp->dc_tq != NULL)
2620 				(void) taskq_dispatch(dcp->dc_tq,
2621 				    dmu_objset_find_dp_cb, child_dcp, TQ_SLEEP);
2622 			else
2623 				dmu_objset_find_dp_impl(child_dcp);
2624 		}
2625 		zap_cursor_fini(&zc);
2626 	}
2627 
2628 	/*
2629 	 * Iterate over all snapshots.
2630 	 */
2631 	if (dcp->dc_flags & DS_FIND_SNAPSHOTS) {
2632 		dsl_dataset_t *ds;
2633 		err = dsl_dataset_hold_obj(dp, thisobj, FTAG, &ds);
2634 
2635 		if (err == 0) {
2636 			uint64_t snapobj;
2637 
2638 			snapobj = dsl_dataset_phys(ds)->ds_snapnames_zapobj;
2639 			dsl_dataset_rele(ds, FTAG);
2640 
2641 			for (zap_cursor_init(&zc, dp->dp_meta_objset, snapobj);
2642 			    zap_cursor_retrieve(&zc, attr) == 0;
2643 			    (void) zap_cursor_advance(&zc)) {
2644 				ASSERT3U(attr->za_integer_length, ==,
2645 				    sizeof (uint64_t));
2646 				ASSERT3U(attr->za_num_integers, ==, 1);
2647 
2648 				err = dsl_dataset_hold_obj(dp,
2649 				    attr->za_first_integer, FTAG, &ds);
2650 				if (err != 0)
2651 					break;
2652 				err = dcp->dc_func(dp, ds, dcp->dc_arg);
2653 				dsl_dataset_rele(ds, FTAG);
2654 				if (err != 0)
2655 					break;
2656 			}
2657 			zap_cursor_fini(&zc);
2658 		}
2659 	}
2660 
2661 	kmem_free(attr, sizeof (zap_attribute_t));
2662 
2663 	if (err != 0) {
2664 		dsl_dir_rele(dd, FTAG);
2665 		goto out;
2666 	}
2667 
2668 	/*
2669 	 * Apply to self.
2670 	 */
2671 	err = dsl_dataset_hold_obj(dp, thisobj, FTAG, &ds);
2672 
2673 	/*
2674 	 * Note: we hold the dir while calling dsl_dataset_hold_obj() so
2675 	 * that the dir will remain cached, and we won't have to re-instantiate
2676 	 * it (which could be expensive due to finding its name via
2677 	 * zap_value_search()).
2678 	 */
2679 	dsl_dir_rele(dd, FTAG);
2680 	if (err != 0)
2681 		goto out;
2682 	err = dcp->dc_func(dp, ds, dcp->dc_arg);
2683 	dsl_dataset_rele(ds, FTAG);
2684 
2685 out:
2686 	if (err != 0) {
2687 		mutex_enter(dcp->dc_error_lock);
2688 		/* only keep first error */
2689 		if (*dcp->dc_error == 0)
2690 			*dcp->dc_error = err;
2691 		mutex_exit(dcp->dc_error_lock);
2692 	}
2693 
2694 	if (dcp->dc_ddname != NULL)
2695 		spa_strfree(dcp->dc_ddname);
2696 	kmem_free(dcp, sizeof (*dcp));
2697 }
2698 
2699 static void
2700 dmu_objset_find_dp_cb(void *arg)
2701 {
2702 	dmu_objset_find_ctx_t *dcp = arg;
2703 	dsl_pool_t *dp = dcp->dc_dp;
2704 
2705 	/*
2706 	 * We need to get a pool_config_lock here, as there are several
2707 	 * asssert(pool_config_held) down the stack. Getting a lock via
2708 	 * dsl_pool_config_enter is risky, as it might be stalled by a
2709 	 * pending writer. This would deadlock, as the write lock can
2710 	 * only be granted when our parent thread gives up the lock.
2711 	 * The _prio interface gives us priority over a pending writer.
2712 	 */
2713 	dsl_pool_config_enter_prio(dp, FTAG);
2714 
2715 	dmu_objset_find_dp_impl(dcp);
2716 
2717 	dsl_pool_config_exit(dp, FTAG);
2718 }
2719 
2720 /*
2721  * Find objsets under and including ddobj, call func(ds) on each.
2722  * The order for the enumeration is completely undefined.
2723  * func is called with dsl_pool_config held.
2724  */
2725 int
2726 dmu_objset_find_dp(dsl_pool_t *dp, uint64_t ddobj,
2727     int func(dsl_pool_t *, dsl_dataset_t *, void *), void *arg, int flags)
2728 {
2729 	int error = 0;
2730 	taskq_t *tq = NULL;
2731 	int ntasks;
2732 	dmu_objset_find_ctx_t *dcp;
2733 	kmutex_t err_lock;
2734 
2735 	mutex_init(&err_lock, NULL, MUTEX_DEFAULT, NULL);
2736 	dcp = kmem_alloc(sizeof (*dcp), KM_SLEEP);
2737 	dcp->dc_tq = NULL;
2738 	dcp->dc_dp = dp;
2739 	dcp->dc_ddobj = ddobj;
2740 	dcp->dc_ddname = NULL;
2741 	dcp->dc_func = func;
2742 	dcp->dc_arg = arg;
2743 	dcp->dc_flags = flags;
2744 	dcp->dc_error_lock = &err_lock;
2745 	dcp->dc_error = &error;
2746 
2747 	if ((flags & DS_FIND_SERIALIZE) || dsl_pool_config_held_writer(dp)) {
2748 		/*
2749 		 * In case a write lock is held we can't make use of
2750 		 * parallelism, as down the stack of the worker threads
2751 		 * the lock is asserted via dsl_pool_config_held.
2752 		 * In case of a read lock this is solved by getting a read
2753 		 * lock in each worker thread, which isn't possible in case
2754 		 * of a writer lock. So we fall back to the synchronous path
2755 		 * here.
2756 		 * In the future it might be possible to get some magic into
2757 		 * dsl_pool_config_held in a way that it returns true for
2758 		 * the worker threads so that a single lock held from this
2759 		 * thread suffices. For now, stay single threaded.
2760 		 */
2761 		dmu_objset_find_dp_impl(dcp);
2762 		mutex_destroy(&err_lock);
2763 
2764 		return (error);
2765 	}
2766 
2767 	ntasks = dmu_find_threads;
2768 	if (ntasks == 0)
2769 		ntasks = vdev_count_leaves(dp->dp_spa) * 4;
2770 	tq = taskq_create("dmu_objset_find", ntasks, minclsyspri, ntasks,
2771 	    INT_MAX, 0);
2772 	if (tq == NULL) {
2773 		kmem_free(dcp, sizeof (*dcp));
2774 		mutex_destroy(&err_lock);
2775 
2776 		return (SET_ERROR(ENOMEM));
2777 	}
2778 	dcp->dc_tq = tq;
2779 
2780 	/* dcp will be freed by task */
2781 	(void) taskq_dispatch(tq, dmu_objset_find_dp_cb, dcp, TQ_SLEEP);
2782 
2783 	/*
2784 	 * PORTING: this code relies on the property of taskq_wait to wait
2785 	 * until no more tasks are queued and no more tasks are active. As
2786 	 * we always queue new tasks from within other tasks, task_wait
2787 	 * reliably waits for the full recursion to finish, even though we
2788 	 * enqueue new tasks after taskq_wait has been called.
2789 	 * On platforms other than illumos, taskq_wait may not have this
2790 	 * property.
2791 	 */
2792 	taskq_wait(tq);
2793 	taskq_destroy(tq);
2794 	mutex_destroy(&err_lock);
2795 
2796 	return (error);
2797 }
2798 
2799 /*
2800  * Find all objsets under name, and for each, call 'func(child_name, arg)'.
2801  * The dp_config_rwlock must not be held when this is called, and it
2802  * will not be held when the callback is called.
2803  * Therefore this function should only be used when the pool is not changing
2804  * (e.g. in syncing context), or the callback can deal with the possible races.
2805  */
2806 static int
2807 dmu_objset_find_impl(spa_t *spa, const char *name,
2808     int func(const char *, void *), void *arg, int flags)
2809 {
2810 	dsl_dir_t *dd;
2811 	dsl_pool_t *dp = spa_get_dsl(spa);
2812 	dsl_dataset_t *ds;
2813 	zap_cursor_t zc;
2814 	zap_attribute_t *attr;
2815 	char *child;
2816 	uint64_t thisobj;
2817 	int err;
2818 
2819 	dsl_pool_config_enter(dp, FTAG);
2820 
2821 	err = dsl_dir_hold(dp, name, FTAG, &dd, NULL);
2822 	if (err != 0) {
2823 		dsl_pool_config_exit(dp, FTAG);
2824 		return (err);
2825 	}
2826 
2827 	/* Don't visit hidden ($MOS & $ORIGIN) objsets. */
2828 	if (dd->dd_myname[0] == '$') {
2829 		dsl_dir_rele(dd, FTAG);
2830 		dsl_pool_config_exit(dp, FTAG);
2831 		return (0);
2832 	}
2833 
2834 	thisobj = dsl_dir_phys(dd)->dd_head_dataset_obj;
2835 	attr = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
2836 
2837 	/*
2838 	 * Iterate over all children.
2839 	 */
2840 	if (flags & DS_FIND_CHILDREN) {
2841 		for (zap_cursor_init(&zc, dp->dp_meta_objset,
2842 		    dsl_dir_phys(dd)->dd_child_dir_zapobj);
2843 		    zap_cursor_retrieve(&zc, attr) == 0;
2844 		    (void) zap_cursor_advance(&zc)) {
2845 			ASSERT3U(attr->za_integer_length, ==,
2846 			    sizeof (uint64_t));
2847 			ASSERT3U(attr->za_num_integers, ==, 1);
2848 
2849 			child = kmem_asprintf("%s/%s", name, attr->za_name);
2850 			dsl_pool_config_exit(dp, FTAG);
2851 			err = dmu_objset_find_impl(spa, child,
2852 			    func, arg, flags);
2853 			dsl_pool_config_enter(dp, FTAG);
2854 			strfree(child);
2855 			if (err != 0)
2856 				break;
2857 		}
2858 		zap_cursor_fini(&zc);
2859 
2860 		if (err != 0) {
2861 			dsl_dir_rele(dd, FTAG);
2862 			dsl_pool_config_exit(dp, FTAG);
2863 			kmem_free(attr, sizeof (zap_attribute_t));
2864 			return (err);
2865 		}
2866 	}
2867 
2868 	/*
2869 	 * Iterate over all snapshots.
2870 	 */
2871 	if (flags & DS_FIND_SNAPSHOTS) {
2872 		err = dsl_dataset_hold_obj(dp, thisobj, FTAG, &ds);
2873 
2874 		if (err == 0) {
2875 			uint64_t snapobj;
2876 
2877 			snapobj = dsl_dataset_phys(ds)->ds_snapnames_zapobj;
2878 			dsl_dataset_rele(ds, FTAG);
2879 
2880 			for (zap_cursor_init(&zc, dp->dp_meta_objset, snapobj);
2881 			    zap_cursor_retrieve(&zc, attr) == 0;
2882 			    (void) zap_cursor_advance(&zc)) {
2883 				ASSERT3U(attr->za_integer_length, ==,
2884 				    sizeof (uint64_t));
2885 				ASSERT3U(attr->za_num_integers, ==, 1);
2886 
2887 				child = kmem_asprintf("%s@%s",
2888 				    name, attr->za_name);
2889 				dsl_pool_config_exit(dp, FTAG);
2890 				err = func(child, arg);
2891 				dsl_pool_config_enter(dp, FTAG);
2892 				strfree(child);
2893 				if (err != 0)
2894 					break;
2895 			}
2896 			zap_cursor_fini(&zc);
2897 		}
2898 	}
2899 
2900 	dsl_dir_rele(dd, FTAG);
2901 	kmem_free(attr, sizeof (zap_attribute_t));
2902 	dsl_pool_config_exit(dp, FTAG);
2903 
2904 	if (err != 0)
2905 		return (err);
2906 
2907 	/* Apply to self. */
2908 	return (func(name, arg));
2909 }
2910 
2911 /*
2912  * See comment above dmu_objset_find_impl().
2913  */
2914 int
2915 dmu_objset_find(char *name, int func(const char *, void *), void *arg,
2916     int flags)
2917 {
2918 	spa_t *spa;
2919 	int error;
2920 
2921 	error = spa_open(name, &spa, FTAG);
2922 	if (error != 0)
2923 		return (error);
2924 	error = dmu_objset_find_impl(spa, name, func, arg, flags);
2925 	spa_close(spa, FTAG);
2926 	return (error);
2927 }
2928 
2929 boolean_t
2930 dmu_objset_incompatible_encryption_version(objset_t *os)
2931 {
2932 	return (dsl_dir_incompatible_encryption_version(
2933 	    os->os_dsl_dataset->ds_dir));
2934 }
2935 
2936 void
2937 dmu_objset_set_user(objset_t *os, void *user_ptr)
2938 {
2939 	ASSERT(MUTEX_HELD(&os->os_user_ptr_lock));
2940 	os->os_user_ptr = user_ptr;
2941 }
2942 
2943 void *
2944 dmu_objset_get_user(objset_t *os)
2945 {
2946 	ASSERT(MUTEX_HELD(&os->os_user_ptr_lock));
2947 	return (os->os_user_ptr);
2948 }
2949 
2950 /*
2951  * Determine name of filesystem, given name of snapshot.
2952  * buf must be at least ZFS_MAX_DATASET_NAME_LEN bytes
2953  */
2954 int
2955 dmu_fsname(const char *snapname, char *buf)
2956 {
2957 	char *atp = strchr(snapname, '@');
2958 	if (atp == NULL)
2959 		return (SET_ERROR(EINVAL));
2960 	if (atp - snapname >= ZFS_MAX_DATASET_NAME_LEN)
2961 		return (SET_ERROR(ENAMETOOLONG));
2962 	(void) strlcpy(buf, snapname, atp - snapname + 1);
2963 	return (0);
2964 }
2965 
2966 /*
2967  * Call when we think we're going to write/free space in open context to track
2968  * the amount of dirty data in the open txg, which is also the amount
2969  * of memory that can not be evicted until this txg syncs.
2970  */
2971 void
2972 dmu_objset_willuse_space(objset_t *os, int64_t space, dmu_tx_t *tx)
2973 {
2974 	dsl_dataset_t *ds = os->os_dsl_dataset;
2975 	int64_t aspace = spa_get_worst_case_asize(os->os_spa, space);
2976 
2977 	if (ds != NULL) {
2978 		dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
2979 		dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
2980 	}
2981 }
2982