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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 /*
     22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #include <sys/cred.h>
     27 #include <sys/zfs_context.h>
     28 #include <sys/dmu_objset.h>
     29 #include <sys/dsl_dir.h>
     30 #include <sys/dsl_dataset.h>
     31 #include <sys/dsl_prop.h>
     32 #include <sys/dsl_pool.h>
     33 #include <sys/dsl_synctask.h>
     34 #include <sys/dsl_deleg.h>
     35 #include <sys/dnode.h>
     36 #include <sys/dbuf.h>
     37 #include <sys/zvol.h>
     38 #include <sys/dmu_tx.h>
     39 #include <sys/zio_checksum.h>
     40 #include <sys/zap.h>
     41 #include <sys/zil.h>
     42 #include <sys/dmu_impl.h>
     43 #include <sys/zfs_ioctl.h>
     44 
     45 spa_t *
     46 dmu_objset_spa(objset_t *os)
     47 {
     48 	return (os->os->os_spa);
     49 }
     50 
     51 zilog_t *
     52 dmu_objset_zil(objset_t *os)
     53 {
     54 	return (os->os->os_zil);
     55 }
     56 
     57 dsl_pool_t *
     58 dmu_objset_pool(objset_t *os)
     59 {
     60 	dsl_dataset_t *ds;
     61 
     62 	if ((ds = os->os->os_dsl_dataset) != NULL && ds->ds_dir)
     63 		return (ds->ds_dir->dd_pool);
     64 	else
     65 		return (spa_get_dsl(os->os->os_spa));
     66 }
     67 
     68 dsl_dataset_t *
     69 dmu_objset_ds(objset_t *os)
     70 {
     71 	return (os->os->os_dsl_dataset);
     72 }
     73 
     74 dmu_objset_type_t
     75 dmu_objset_type(objset_t *os)
     76 {
     77 	return (os->os->os_phys->os_type);
     78 }
     79 
     80 void
     81 dmu_objset_name(objset_t *os, char *buf)
     82 {
     83 	dsl_dataset_name(os->os->os_dsl_dataset, buf);
     84 }
     85 
     86 uint64_t
     87 dmu_objset_id(objset_t *os)
     88 {
     89 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
     90 
     91 	return (ds ? ds->ds_object : 0);
     92 }
     93 
     94 static void
     95 checksum_changed_cb(void *arg, uint64_t newval)
     96 {
     97 	objset_impl_t *osi = arg;
     98 
     99 	/*
    100 	 * Inheritance should have been done by now.
    101 	 */
    102 	ASSERT(newval != ZIO_CHECKSUM_INHERIT);
    103 
    104 	osi->os_checksum = zio_checksum_select(newval, ZIO_CHECKSUM_ON_VALUE);
    105 }
    106 
    107 static void
    108 compression_changed_cb(void *arg, uint64_t newval)
    109 {
    110 	objset_impl_t *osi = arg;
    111 
    112 	/*
    113 	 * Inheritance and range checking should have been done by now.
    114 	 */
    115 	ASSERT(newval != ZIO_COMPRESS_INHERIT);
    116 
    117 	osi->os_compress = zio_compress_select(newval, ZIO_COMPRESS_ON_VALUE);
    118 }
    119 
    120 static void
    121 copies_changed_cb(void *arg, uint64_t newval)
    122 {
    123 	objset_impl_t *osi = arg;
    124 
    125 	/*
    126 	 * Inheritance and range checking should have been done by now.
    127 	 */
    128 	ASSERT(newval > 0);
    129 	ASSERT(newval <= spa_max_replication(osi->os_spa));
    130 
    131 	osi->os_copies = newval;
    132 }
    133 
    134 static void
    135 primary_cache_changed_cb(void *arg, uint64_t newval)
    136 {
    137 	objset_impl_t *osi = arg;
    138 
    139 	/*
    140 	 * Inheritance and range checking should have been done by now.
    141 	 */
    142 	ASSERT(newval == ZFS_CACHE_ALL || newval == ZFS_CACHE_NONE ||
    143 	    newval == ZFS_CACHE_METADATA);
    144 
    145 	osi->os_primary_cache = newval;
    146 }
    147 
    148 static void
    149 secondary_cache_changed_cb(void *arg, uint64_t newval)
    150 {
    151 	objset_impl_t *osi = arg;
    152 
    153 	/*
    154 	 * Inheritance and range checking should have been done by now.
    155 	 */
    156 	ASSERT(newval == ZFS_CACHE_ALL || newval == ZFS_CACHE_NONE ||
    157 	    newval == ZFS_CACHE_METADATA);
    158 
    159 	osi->os_secondary_cache = newval;
    160 }
    161 
    162 void
    163 dmu_objset_byteswap(void *buf, size_t size)
    164 {
    165 	objset_phys_t *osp = buf;
    166 
    167 	ASSERT(size == OBJSET_OLD_PHYS_SIZE || size == sizeof (objset_phys_t));
    168 	dnode_byteswap(&osp->os_meta_dnode);
    169 	byteswap_uint64_array(&osp->os_zil_header, sizeof (zil_header_t));
    170 	osp->os_type = BSWAP_64(osp->os_type);
    171 	osp->os_flags = BSWAP_64(osp->os_flags);
    172 	if (size == sizeof (objset_phys_t)) {
    173 		dnode_byteswap(&osp->os_userused_dnode);
    174 		dnode_byteswap(&osp->os_groupused_dnode);
    175 	}
    176 }
    177 
    178 int
    179 dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
    180     objset_impl_t **osip)
    181 {
    182 	objset_impl_t *osi;
    183 	int i, err;
    184 
    185 	ASSERT(ds == NULL || MUTEX_HELD(&ds->ds_opening_lock));
    186 
    187 	osi = kmem_zalloc(sizeof (objset_impl_t), KM_SLEEP);
    188 	osi->os.os = osi;
    189 	osi->os_dsl_dataset = ds;
    190 	osi->os_spa = spa;
    191 	osi->os_rootbp = bp;
    192 	if (!BP_IS_HOLE(osi->os_rootbp)) {
    193 		uint32_t aflags = ARC_WAIT;
    194 		zbookmark_t zb;
    195 		zb.zb_objset = ds ? ds->ds_object : 0;
    196 		zb.zb_object = 0;
    197 		zb.zb_level = -1;
    198 		zb.zb_blkid = 0;
    199 		if (DMU_OS_IS_L2CACHEABLE(osi))
    200 			aflags |= ARC_L2CACHE;
    201 
    202 		dprintf_bp(osi->os_rootbp, "reading %s", "");
    203 		/*
    204 		 * NB: when bprewrite scrub can change the bp,
    205 		 * and this is called from dmu_objset_open_ds_os, the bp
    206 		 * could change, and we'll need a lock.
    207 		 */
    208 		err = arc_read_nolock(NULL, spa, osi->os_rootbp,
    209 		    arc_getbuf_func, &osi->os_phys_buf,
    210 		    ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL, &aflags, &zb);
    211 		if (err) {
    212 			kmem_free(osi, sizeof (objset_impl_t));
    213 			/* convert checksum errors into IO errors */
    214 			if (err == ECKSUM)
    215 				err = EIO;
    216 			return (err);
    217 		}
    218 
    219 		/* Increase the blocksize if we are permitted. */
    220 		if (spa_version(spa) >= SPA_VERSION_USERSPACE &&
    221 		    arc_buf_size(osi->os_phys_buf) < sizeof (objset_phys_t)) {
    222 			arc_buf_t *buf = arc_buf_alloc(spa,
    223 			    sizeof (objset_phys_t), &osi->os_phys_buf,
    224 			    ARC_BUFC_METADATA);
    225 			bzero(buf->b_data, sizeof (objset_phys_t));
    226 			bcopy(osi->os_phys_buf->b_data, buf->b_data,
    227 			    arc_buf_size(osi->os_phys_buf));
    228 			(void) arc_buf_remove_ref(osi->os_phys_buf,
    229 			    &osi->os_phys_buf);
    230 			osi->os_phys_buf = buf;
    231 		}
    232 
    233 		osi->os_phys = osi->os_phys_buf->b_data;
    234 		osi->os_flags = osi->os_phys->os_flags;
    235 	} else {
    236 		int size = spa_version(spa) >= SPA_VERSION_USERSPACE ?
    237 		    sizeof (objset_phys_t) : OBJSET_OLD_PHYS_SIZE;
    238 		osi->os_phys_buf = arc_buf_alloc(spa, size,
    239 		    &osi->os_phys_buf, ARC_BUFC_METADATA);
    240 		osi->os_phys = osi->os_phys_buf->b_data;
    241 		bzero(osi->os_phys, size);
    242 	}
    243 
    244 	/*
    245 	 * Note: the changed_cb will be called once before the register
    246 	 * func returns, thus changing the checksum/compression from the
    247 	 * default (fletcher2/off).  Snapshots don't need to know about
    248 	 * checksum/compression/copies.
    249 	 */
    250 	if (ds) {
    251 		err = dsl_prop_register(ds, "primarycache",
    252 		    primary_cache_changed_cb, osi);
    253 		if (err == 0)
    254 			err = dsl_prop_register(ds, "secondarycache",
    255 			    secondary_cache_changed_cb, osi);
    256 		if (!dsl_dataset_is_snapshot(ds)) {
    257 			if (err == 0)
    258 				err = dsl_prop_register(ds, "checksum",
    259 				    checksum_changed_cb, osi);
    260 			if (err == 0)
    261 				err = dsl_prop_register(ds, "compression",
    262 				    compression_changed_cb, osi);
    263 			if (err == 0)
    264 				err = dsl_prop_register(ds, "copies",
    265 				    copies_changed_cb, osi);
    266 		}
    267 		if (err) {
    268 			VERIFY(arc_buf_remove_ref(osi->os_phys_buf,
    269 			    &osi->os_phys_buf) == 1);
    270 			kmem_free(osi, sizeof (objset_impl_t));
    271 			return (err);
    272 		}
    273 	} else if (ds == NULL) {
    274 		/* It's the meta-objset. */
    275 		osi->os_checksum = ZIO_CHECKSUM_FLETCHER_4;
    276 		osi->os_compress = ZIO_COMPRESS_LZJB;
    277 		osi->os_copies = spa_max_replication(spa);
    278 		osi->os_primary_cache = ZFS_CACHE_ALL;
    279 		osi->os_secondary_cache = ZFS_CACHE_ALL;
    280 	}
    281 
    282 	osi->os_zil_header = osi->os_phys->os_zil_header;
    283 	osi->os_zil = zil_alloc(&osi->os, &osi->os_zil_header);
    284 
    285 	for (i = 0; i < TXG_SIZE; i++) {
    286 		list_create(&osi->os_dirty_dnodes[i], sizeof (dnode_t),
    287 		    offsetof(dnode_t, dn_dirty_link[i]));
    288 		list_create(&osi->os_free_dnodes[i], sizeof (dnode_t),
    289 		    offsetof(dnode_t, dn_dirty_link[i]));
    290 	}
    291 	list_create(&osi->os_dnodes, sizeof (dnode_t),
    292 	    offsetof(dnode_t, dn_link));
    293 	list_create(&osi->os_downgraded_dbufs, sizeof (dmu_buf_impl_t),
    294 	    offsetof(dmu_buf_impl_t, db_link));
    295 
    296 	mutex_init(&osi->os_lock, NULL, MUTEX_DEFAULT, NULL);
    297 	mutex_init(&osi->os_obj_lock, NULL, MUTEX_DEFAULT, NULL);
    298 	mutex_init(&osi->os_user_ptr_lock, NULL, MUTEX_DEFAULT, NULL);
    299 
    300 	osi->os_meta_dnode = dnode_special_open(osi,
    301 	    &osi->os_phys->os_meta_dnode, DMU_META_DNODE_OBJECT);
    302 	if (arc_buf_size(osi->os_phys_buf) >= sizeof (objset_phys_t)) {
    303 		osi->os_userused_dnode = dnode_special_open(osi,
    304 		    &osi->os_phys->os_userused_dnode, DMU_USERUSED_OBJECT);
    305 		osi->os_groupused_dnode = dnode_special_open(osi,
    306 		    &osi->os_phys->os_groupused_dnode, DMU_GROUPUSED_OBJECT);
    307 	}
    308 
    309 	/*
    310 	 * We should be the only thread trying to do this because we
    311 	 * have ds_opening_lock
    312 	 */
    313 	if (ds) {
    314 		VERIFY(NULL == dsl_dataset_set_user_ptr(ds, osi,
    315 		    dmu_objset_evict));
    316 	}
    317 
    318 	*osip = osi;
    319 	return (0);
    320 }
    321 
    322 static int
    323 dmu_objset_open_ds_os(dsl_dataset_t *ds, objset_t *os, dmu_objset_type_t type)
    324 {
    325 	objset_impl_t *osi;
    326 
    327 	mutex_enter(&ds->ds_opening_lock);
    328 	osi = dsl_dataset_get_user_ptr(ds);
    329 	if (osi == NULL) {
    330 		int err;
    331 
    332 		err = dmu_objset_open_impl(dsl_dataset_get_spa(ds),
    333 		    ds, &ds->ds_phys->ds_bp, &osi);
    334 		if (err) {
    335 			mutex_exit(&ds->ds_opening_lock);
    336 			return (err);
    337 		}
    338 	}
    339 	mutex_exit(&ds->ds_opening_lock);
    340 
    341 	os->os = osi;
    342 	os->os_mode = DS_MODE_NOHOLD;
    343 
    344 	if (type != DMU_OST_ANY && type != os->os->os_phys->os_type)
    345 		return (EINVAL);
    346 	return (0);
    347 }
    348 
    349 int
    350 dmu_objset_open_ds(dsl_dataset_t *ds, dmu_objset_type_t type, objset_t **osp)
    351 {
    352 	objset_t *os;
    353 	int err;
    354 
    355 	os = kmem_alloc(sizeof (objset_t), KM_SLEEP);
    356 	err = dmu_objset_open_ds_os(ds, os, type);
    357 	if (err)
    358 		kmem_free(os, sizeof (objset_t));
    359 	else
    360 		*osp = os;
    361 	return (err);
    362 }
    363 
    364 /* called from zpl */
    365 int
    366 dmu_objset_open(const char *name, dmu_objset_type_t type, int mode,
    367     objset_t **osp)
    368 {
    369 	objset_t *os;
    370 	dsl_dataset_t *ds;
    371 	int err;
    372 
    373 	ASSERT(DS_MODE_TYPE(mode) == DS_MODE_USER ||
    374 	    DS_MODE_TYPE(mode) == DS_MODE_OWNER);
    375 
    376 	os = kmem_alloc(sizeof (objset_t), KM_SLEEP);
    377 	if (DS_MODE_TYPE(mode) == DS_MODE_USER)
    378 		err = dsl_dataset_hold(name, os, &ds);
    379 	else
    380 		err = dsl_dataset_own(name, mode, os, &ds);
    381 	if (err) {
    382 		kmem_free(os, sizeof (objset_t));
    383 		return (err);
    384 	}
    385 
    386 	err = dmu_objset_open_ds_os(ds, os, type);
    387 	if (err) {
    388 		if (DS_MODE_TYPE(mode) == DS_MODE_USER)
    389 			dsl_dataset_rele(ds, os);
    390 		else
    391 			dsl_dataset_disown(ds, os);
    392 		kmem_free(os, sizeof (objset_t));
    393 	} else {
    394 		os->os_mode = mode;
    395 		*osp = os;
    396 	}
    397 	return (err);
    398 }
    399 
    400 void
    401 dmu_objset_close(objset_t *os)
    402 {
    403 	ASSERT(DS_MODE_TYPE(os->os_mode) == DS_MODE_USER ||
    404 	    DS_MODE_TYPE(os->os_mode) == DS_MODE_OWNER ||
    405 	    DS_MODE_TYPE(os->os_mode) == DS_MODE_NOHOLD);
    406 
    407 	if (DS_MODE_TYPE(os->os_mode) == DS_MODE_USER)
    408 		dsl_dataset_rele(os->os->os_dsl_dataset, os);
    409 	else if (DS_MODE_TYPE(os->os_mode) == DS_MODE_OWNER)
    410 		dsl_dataset_disown(os->os->os_dsl_dataset, os);
    411 	kmem_free(os, sizeof (objset_t));
    412 }
    413 
    414 int
    415 dmu_objset_evict_dbufs(objset_t *os)
    416 {
    417 	objset_impl_t *osi = os->os;
    418 	dnode_t *dn;
    419 
    420 	mutex_enter(&osi->os_lock);
    421 
    422 	/* process the mdn last, since the other dnodes have holds on it */
    423 	list_remove(&osi->os_dnodes, osi->os_meta_dnode);
    424 	list_insert_tail(&osi->os_dnodes, osi->os_meta_dnode);
    425 
    426 	/*
    427 	 * Find the first dnode with holds.  We have to do this dance
    428 	 * because dnode_add_ref() only works if you already have a
    429 	 * hold.  If there are no holds then it has no dbufs so OK to
    430 	 * skip.
    431 	 */
    432 	for (dn = list_head(&osi->os_dnodes);
    433 	    dn && !dnode_add_ref(dn, FTAG);
    434 	    dn = list_next(&osi->os_dnodes, dn))
    435 		continue;
    436 
    437 	while (dn) {
    438 		dnode_t *next_dn = dn;
    439 
    440 		do {
    441 			next_dn = list_next(&osi->os_dnodes, next_dn);
    442 		} while (next_dn && !dnode_add_ref(next_dn, FTAG));
    443 
    444 		mutex_exit(&osi->os_lock);
    445 		dnode_evict_dbufs(dn);
    446 		dnode_rele(dn, FTAG);
    447 		mutex_enter(&osi->os_lock);
    448 		dn = next_dn;
    449 	}
    450 	mutex_exit(&osi->os_lock);
    451 	return (list_head(&osi->os_dnodes) != osi->os_meta_dnode);
    452 }
    453 
    454 void
    455 dmu_objset_evict(dsl_dataset_t *ds, void *arg)
    456 {
    457 	objset_impl_t *osi = arg;
    458 	objset_t os;
    459 	int i;
    460 
    461 	for (i = 0; i < TXG_SIZE; i++) {
    462 		ASSERT(list_head(&osi->os_dirty_dnodes[i]) == NULL);
    463 		ASSERT(list_head(&osi->os_free_dnodes[i]) == NULL);
    464 	}
    465 
    466 	if (ds) {
    467 		if (!dsl_dataset_is_snapshot(ds)) {
    468 			VERIFY(0 == dsl_prop_unregister(ds, "checksum",
    469 			    checksum_changed_cb, osi));
    470 			VERIFY(0 == dsl_prop_unregister(ds, "compression",
    471 			    compression_changed_cb, osi));
    472 			VERIFY(0 == dsl_prop_unregister(ds, "copies",
    473 			    copies_changed_cb, osi));
    474 		}
    475 		VERIFY(0 == dsl_prop_unregister(ds, "primarycache",
    476 		    primary_cache_changed_cb, osi));
    477 		VERIFY(0 == dsl_prop_unregister(ds, "secondarycache",
    478 		    secondary_cache_changed_cb, osi));
    479 	}
    480 
    481 	/*
    482 	 * We should need only a single pass over the dnode list, since
    483 	 * nothing can be added to the list at this point.
    484 	 */
    485 	os.os = osi;
    486 	(void) dmu_objset_evict_dbufs(&os);
    487 
    488 	dnode_special_close(osi->os_meta_dnode);
    489 	if (osi->os_userused_dnode) {
    490 		dnode_special_close(osi->os_userused_dnode);
    491 		dnode_special_close(osi->os_groupused_dnode);
    492 	}
    493 	zil_free(osi->os_zil);
    494 
    495 	ASSERT3P(list_head(&osi->os_dnodes), ==, NULL);
    496 
    497 	VERIFY(arc_buf_remove_ref(osi->os_phys_buf, &osi->os_phys_buf) == 1);
    498 	mutex_destroy(&osi->os_lock);
    499 	mutex_destroy(&osi->os_obj_lock);
    500 	mutex_destroy(&osi->os_user_ptr_lock);
    501 	kmem_free(osi, sizeof (objset_impl_t));
    502 }
    503 
    504 /* called from dsl for meta-objset */
    505 objset_impl_t *
    506 dmu_objset_create_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
    507     dmu_objset_type_t type, dmu_tx_t *tx)
    508 {
    509 	objset_impl_t *osi;
    510 	dnode_t *mdn;
    511 
    512 	ASSERT(dmu_tx_is_syncing(tx));
    513 	if (ds)
    514 		mutex_enter(&ds->ds_opening_lock);
    515 	VERIFY(0 == dmu_objset_open_impl(spa, ds, bp, &osi));
    516 	if (ds)
    517 		mutex_exit(&ds->ds_opening_lock);
    518 	mdn = osi->os_meta_dnode;
    519 
    520 	dnode_allocate(mdn, DMU_OT_DNODE, 1 << DNODE_BLOCK_SHIFT,
    521 	    DN_MAX_INDBLKSHIFT, DMU_OT_NONE, 0, tx);
    522 
    523 	/*
    524 	 * We don't want to have to increase the meta-dnode's nlevels
    525 	 * later, because then we could do it in quescing context while
    526 	 * we are also accessing it in open context.
    527 	 *
    528 	 * This precaution is not necessary for the MOS (ds == NULL),
    529 	 * because the MOS is only updated in syncing context.
    530 	 * This is most fortunate: the MOS is the only objset that
    531 	 * needs to be synced multiple times as spa_sync() iterates
    532 	 * to convergence, so minimizing its dn_nlevels matters.
    533 	 */
    534 	if (ds != NULL) {
    535 		int levels = 1;
    536 
    537 		/*
    538 		 * Determine the number of levels necessary for the meta-dnode
    539 		 * to contain DN_MAX_OBJECT dnodes.
    540 		 */
    541 		while ((uint64_t)mdn->dn_nblkptr << (mdn->dn_datablkshift +
    542 		    (levels - 1) * (mdn->dn_indblkshift - SPA_BLKPTRSHIFT)) <
    543 		    DN_MAX_OBJECT * sizeof (dnode_phys_t))
    544 			levels++;
    545 
    546 		mdn->dn_next_nlevels[tx->tx_txg & TXG_MASK] =
    547 		    mdn->dn_nlevels = levels;
    548 	}
    549 
    550 	ASSERT(type != DMU_OST_NONE);
    551 	ASSERT(type != DMU_OST_ANY);
    552 	ASSERT(type < DMU_OST_NUMTYPES);
    553 	osi->os_phys->os_type = type;
    554 	if (dmu_objset_userused_enabled(osi)) {
    555 		osi->os_phys->os_flags |= OBJSET_FLAG_USERACCOUNTING_COMPLETE;
    556 		osi->os_flags = osi->os_phys->os_flags;
    557 	}
    558 
    559 	dsl_dataset_dirty(ds, tx);
    560 
    561 	return (osi);
    562 }
    563 
    564 struct oscarg {
    565 	void (*userfunc)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx);
    566 	void *userarg;
    567 	dsl_dataset_t *clone_parent;
    568 	const char *lastname;
    569 	dmu_objset_type_t type;
    570 	uint64_t flags;
    571 };
    572 
    573 /*ARGSUSED*/
    574 static int
    575 dmu_objset_create_check(void *arg1, void *arg2, dmu_tx_t *tx)
    576 {
    577 	dsl_dir_t *dd = arg1;
    578 	struct oscarg *oa = arg2;
    579 	objset_t *mos = dd->dd_pool->dp_meta_objset;
    580 	int err;
    581 	uint64_t ddobj;
    582 
    583 	err = zap_lookup(mos, dd->dd_phys->dd_child_dir_zapobj,
    584 	    oa->lastname, sizeof (uint64_t), 1, &ddobj);
    585 	if (err != ENOENT)
    586 		return (err ? err : EEXIST);
    587 
    588 	if (oa->clone_parent != NULL) {
    589 		/*
    590 		 * You can't clone across pools.
    591 		 */
    592 		if (oa->clone_parent->ds_dir->dd_pool != dd->dd_pool)
    593 			return (EXDEV);
    594 
    595 		/*
    596 		 * You can only clone snapshots, not the head datasets.
    597 		 */
    598 		if (oa->clone_parent->ds_phys->ds_num_children == 0)
    599 			return (EINVAL);
    600 	}
    601 
    602 	return (0);
    603 }
    604 
    605 static void
    606 dmu_objset_create_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
    607 {
    608 	dsl_dir_t *dd = arg1;
    609 	struct oscarg *oa = arg2;
    610 	dsl_dataset_t *ds;
    611 	blkptr_t *bp;
    612 	uint64_t dsobj;
    613 
    614 	ASSERT(dmu_tx_is_syncing(tx));
    615 
    616 	dsobj = dsl_dataset_create_sync(dd, oa->lastname,
    617 	    oa->clone_parent, oa->flags, cr, tx);
    618 
    619 	VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, dsobj, FTAG, &ds));
    620 	bp = dsl_dataset_get_blkptr(ds);
    621 	if (BP_IS_HOLE(bp)) {
    622 		objset_impl_t *osi;
    623 
    624 		/* This is an empty dmu_objset; not a clone. */
    625 		osi = dmu_objset_create_impl(dsl_dataset_get_spa(ds),
    626 		    ds, bp, oa->type, tx);
    627 
    628 		if (oa->userfunc)
    629 			oa->userfunc(&osi->os, oa->userarg, cr, tx);
    630 	}
    631 
    632 	spa_history_internal_log(LOG_DS_CREATE, dd->dd_pool->dp_spa,
    633 	    tx, cr, "dataset = %llu", dsobj);
    634 
    635 	dsl_dataset_rele(ds, FTAG);
    636 }
    637 
    638 int
    639 dmu_objset_create(const char *name, dmu_objset_type_t type,
    640     objset_t *clone_parent, uint64_t flags,
    641     void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg)
    642 {
    643 	dsl_dir_t *pdd;
    644 	const char *tail;
    645 	int err = 0;
    646 	struct oscarg oa = { 0 };
    647 
    648 	ASSERT(strchr(name, '@') == NULL);
    649 	err = dsl_dir_open(name, FTAG, &pdd, &tail);
    650 	if (err)
    651 		return (err);
    652 	if (tail == NULL) {
    653 		dsl_dir_close(pdd, FTAG);
    654 		return (EEXIST);
    655 	}
    656 
    657 	dprintf("name=%s\n", name);
    658 
    659 	oa.userfunc = func;
    660 	oa.userarg = arg;
    661 	oa.lastname = tail;
    662 	oa.type = type;
    663 	oa.flags = flags;
    664 
    665 	if (clone_parent != NULL) {
    666 		/*
    667 		 * You can't clone to a different type.
    668 		 */
    669 		if (clone_parent->os->os_phys->os_type != type) {
    670 			dsl_dir_close(pdd, FTAG);
    671 			return (EINVAL);
    672 		}
    673 		oa.clone_parent = clone_parent->os->os_dsl_dataset;
    674 	}
    675 	err = dsl_sync_task_do(pdd->dd_pool, dmu_objset_create_check,
    676 	    dmu_objset_create_sync, pdd, &oa, 5);
    677 	dsl_dir_close(pdd, FTAG);
    678 	return (err);
    679 }
    680 
    681 int
    682 dmu_objset_destroy(const char *name)
    683 {
    684 	objset_t *os;
    685 	int error;
    686 
    687 	/*
    688 	 * If it looks like we'll be able to destroy it, and there's
    689 	 * an unplayed replay log sitting around, destroy the log.
    690 	 * It would be nicer to do this in dsl_dataset_destroy_sync(),
    691 	 * but the replay log objset is modified in open context.
    692 	 */
    693 	error = dmu_objset_open(name, DMU_OST_ANY,
    694 	    DS_MODE_OWNER|DS_MODE_READONLY|DS_MODE_INCONSISTENT, &os);
    695 	if (error == 0) {
    696 		dsl_dataset_t *ds = os->os->os_dsl_dataset;
    697 		zil_destroy(dmu_objset_zil(os), B_FALSE);
    698 
    699 		error = dsl_dataset_destroy(ds, os);
    700 		/*
    701 		 * dsl_dataset_destroy() closes the ds.
    702 		 */
    703 		kmem_free(os, sizeof (objset_t));
    704 	}
    705 
    706 	return (error);
    707 }
    708 
    709 /*
    710  * This will close the objset.
    711  */
    712 int
    713 dmu_objset_rollback(objset_t *os)
    714 {
    715 	int err;
    716 	dsl_dataset_t *ds;
    717 
    718 	ds = os->os->os_dsl_dataset;
    719 
    720 	if (!dsl_dataset_tryown(ds, TRUE, os)) {
    721 		dmu_objset_close(os);
    722 		return (EBUSY);
    723 	}
    724 
    725 	err = dsl_dataset_rollback(ds, os->os->os_phys->os_type);
    726 
    727 	/*
    728 	 * NB: we close the objset manually because the rollback
    729 	 * actually implicitly called dmu_objset_evict(), thus freeing
    730 	 * the objset_impl_t.
    731 	 */
    732 	dsl_dataset_disown(ds, os);
    733 	kmem_free(os, sizeof (objset_t));
    734 	return (err);
    735 }
    736 
    737 struct snaparg {
    738 	dsl_sync_task_group_t *dstg;
    739 	char *snapname;
    740 	char failed[MAXPATHLEN];
    741 	boolean_t checkperms;
    742 	nvlist_t *props;
    743 };
    744 
    745 static int
    746 snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
    747 {
    748 	objset_t *os = arg1;
    749 	struct snaparg *sn = arg2;
    750 
    751 	/* The props have already been checked by zfs_check_userprops(). */
    752 
    753 	return (dsl_dataset_snapshot_check(os->os->os_dsl_dataset,
    754 	    sn->snapname, tx));
    755 }
    756 
    757 static void
    758 snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
    759 {
    760 	objset_t *os = arg1;
    761 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
    762 	struct snaparg *sn = arg2;
    763 
    764 	dsl_dataset_snapshot_sync(ds, sn->snapname, cr, tx);
    765 
    766 	if (sn->props)
    767 		dsl_props_set_sync(ds->ds_prev, sn->props, cr, tx);
    768 }
    769 
    770 static int
    771 dmu_objset_snapshot_one(char *name, void *arg)
    772 {
    773 	struct snaparg *sn = arg;
    774 	objset_t *os;
    775 	int err;
    776 
    777 	(void) strcpy(sn->failed, name);
    778 
    779 	/*
    780 	 * Check permissions only when requested.  This only applies when
    781 	 * doing a recursive snapshot.  The permission checks for the starting
    782 	 * dataset have already been performed in zfs_secpolicy_snapshot()
    783 	 */
    784 	if (sn->checkperms == B_TRUE &&
    785 	    (err = zfs_secpolicy_snapshot_perms(name, CRED())))
    786 		return (err);
    787 
    788 	err = dmu_objset_open(name, DMU_OST_ANY, DS_MODE_USER, &os);
    789 	if (err != 0)
    790 		return (err);
    791 
    792 	/* If the objset is in an inconsistent state, return busy */
    793 	if (os->os->os_dsl_dataset->ds_phys->ds_flags & DS_FLAG_INCONSISTENT) {
    794 		dmu_objset_close(os);
    795 		return (EBUSY);
    796 	}
    797 
    798 	/*
    799 	 * NB: we need to wait for all in-flight changes to get to disk,
    800 	 * so that we snapshot those changes.  zil_suspend does this as
    801 	 * a side effect.
    802 	 */
    803 	err = zil_suspend(dmu_objset_zil(os));
    804 	if (err == 0) {
    805 		dsl_sync_task_create(sn->dstg, snapshot_check,
    806 		    snapshot_sync, os, sn, 3);
    807 	} else {
    808 		dmu_objset_close(os);
    809 	}
    810 
    811 	return (err);
    812 }
    813 
    814 int
    815 dmu_objset_snapshot(char *fsname, char *snapname,
    816     nvlist_t *props, boolean_t recursive)
    817 {
    818 	dsl_sync_task_t *dst;
    819 	struct snaparg sn;
    820 	spa_t *spa;
    821 	int err;
    822 
    823 	(void) strcpy(sn.failed, fsname);
    824 
    825 	err = spa_open(fsname, &spa, FTAG);
    826 	if (err)
    827 		return (err);
    828 
    829 	sn.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
    830 	sn.snapname = snapname;
    831 	sn.props = props;
    832 
    833 	if (recursive) {
    834 		sn.checkperms = B_TRUE;
    835 		err = dmu_objset_find(fsname,
    836 		    dmu_objset_snapshot_one, &sn, DS_FIND_CHILDREN);
    837 	} else {
    838 		sn.checkperms = B_FALSE;
    839 		err = dmu_objset_snapshot_one(fsname, &sn);
    840 	}
    841 
    842 	if (err == 0)
    843 		err = dsl_sync_task_group_wait(sn.dstg);
    844 
    845 	for (dst = list_head(&sn.dstg->dstg_tasks); dst;
    846 	    dst = list_next(&sn.dstg->dstg_tasks, dst)) {
    847 		objset_t *os = dst->dst_arg1;
    848 		dsl_dataset_t *ds = os->os->os_dsl_dataset;
    849 		if (dst->dst_err)
    850 			dsl_dataset_name(ds, sn.failed);
    851 		zil_resume(dmu_objset_zil(os));
    852 		dmu_objset_close(os);
    853 	}
    854 
    855 	if (err)
    856 		(void) strcpy(fsname, sn.failed);
    857 	dsl_sync_task_group_destroy(sn.dstg);
    858 	spa_close(spa, FTAG);
    859 	return (err);
    860 }
    861 
    862 static void
    863 dmu_objset_sync_dnodes(list_t *list, list_t *newlist, dmu_tx_t *tx)
    864 {
    865 	dnode_t *dn;
    866 
    867 	while (dn = list_head(list)) {
    868 		ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
    869 		ASSERT(dn->dn_dbuf->db_data_pending);
    870 		/*
    871 		 * Initialize dn_zio outside dnode_sync() because the
    872 		 * meta-dnode needs to set it ouside dnode_sync().
    873 		 */
    874 		dn->dn_zio = dn->dn_dbuf->db_data_pending->dr_zio;
    875 		ASSERT(dn->dn_zio);
    876 
    877 		ASSERT3U(dn->dn_nlevels, <=, DN_MAX_LEVELS);
    878 		list_remove(list, dn);
    879 
    880 		if (newlist) {
    881 			(void) dnode_add_ref(dn, newlist);
    882 			list_insert_tail(newlist, dn);
    883 		}
    884 
    885 		dnode_sync(dn, tx);
    886 	}
    887 }
    888 
    889 /* ARGSUSED */
    890 static void
    891 ready(zio_t *zio, arc_buf_t *abuf, void *arg)
    892 {
    893 	blkptr_t *bp = zio->io_bp;
    894 	blkptr_t *bp_orig = &zio->io_bp_orig;
    895 	objset_impl_t *os = arg;
    896 	dnode_phys_t *dnp = &os->os_phys->os_meta_dnode;
    897 
    898 	ASSERT(bp == os->os_rootbp);
    899 	ASSERT(BP_GET_TYPE(bp) == DMU_OT_OBJSET);
    900 	ASSERT(BP_GET_LEVEL(bp) == 0);
    901 
    902 	/*
    903 	 * Update rootbp fill count: it should be the number of objects
    904 	 * allocated in the object set (not counting the "special"
    905 	 * objects that are stored in the objset_phys_t -- the meta
    906 	 * dnode and user/group accounting objects).
    907 	 */
    908 	bp->blk_fill = 0;
    909 	for (int i = 0; i < dnp->dn_nblkptr; i++)
    910 		bp->blk_fill += dnp->dn_blkptr[i].blk_fill;
    911 
    912 	if (zio->io_flags & ZIO_FLAG_IO_REWRITE) {
    913 		ASSERT(DVA_EQUAL(BP_IDENTITY(bp), BP_IDENTITY(bp_orig)));
    914 	} else {
    915 		if (zio->io_bp_orig.blk_birth == os->os_synctx->tx_txg)
    916 			(void) dsl_dataset_block_kill(os->os_dsl_dataset,
    917 			    &zio->io_bp_orig, zio, os->os_synctx);
    918 		dsl_dataset_block_born(os->os_dsl_dataset, bp, os->os_synctx);
    919 	}
    920 }
    921 
    922 /* called from dsl */
    923 void
    924 dmu_objset_sync(objset_impl_t *os, zio_t *pio, dmu_tx_t *tx)
    925 {
    926 	int txgoff;
    927 	zbookmark_t zb;
    928 	writeprops_t wp = { 0 };
    929 	zio_t *zio;
    930 	list_t *list;
    931 	list_t *newlist = NULL;
    932 	dbuf_dirty_record_t *dr;
    933 
    934 	dprintf_ds(os->os_dsl_dataset, "txg=%llu\n", tx->tx_txg);
    935 
    936 	ASSERT(dmu_tx_is_syncing(tx));
    937 	/* XXX the write_done callback should really give us the tx... */
    938 	os->os_synctx = tx;
    939 
    940 	if (os->os_dsl_dataset == NULL) {
    941 		/*
    942 		 * This is the MOS.  If we have upgraded,
    943 		 * spa_max_replication() could change, so reset
    944 		 * os_copies here.
    945 		 */
    946 		os->os_copies = spa_max_replication(os->os_spa);
    947 	}
    948 
    949 	/*
    950 	 * Create the root block IO
    951 	 */
    952 	zb.zb_objset = os->os_dsl_dataset ? os->os_dsl_dataset->ds_object : 0;
    953 	zb.zb_object = 0;
    954 	zb.zb_level = -1;	/* for block ordering; it's level 0 on disk */
    955 	zb.zb_blkid = 0;
    956 
    957 	wp.wp_type = DMU_OT_OBJSET;
    958 	wp.wp_level = 0;	/* on-disk BP level; see above */
    959 	wp.wp_copies = os->os_copies;
    960 	wp.wp_oschecksum = os->os_checksum;
    961 	wp.wp_oscompress = os->os_compress;
    962 
    963 	if (BP_IS_OLDER(os->os_rootbp, tx->tx_txg)) {
    964 		(void) dsl_dataset_block_kill(os->os_dsl_dataset,
    965 		    os->os_rootbp, pio, tx);
    966 	}
    967 
    968 	arc_release(os->os_phys_buf, &os->os_phys_buf);
    969 
    970 	zio = arc_write(pio, os->os_spa, &wp, DMU_OS_IS_L2CACHEABLE(os),
    971 	    tx->tx_txg, os->os_rootbp, os->os_phys_buf, ready, NULL, os,
    972 	    ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
    973 
    974 	/*
    975 	 * Sync special dnodes - the parent IO for the sync is the root block
    976 	 */
    977 	os->os_meta_dnode->dn_zio = zio;
    978 	dnode_sync(os->os_meta_dnode, tx);
    979 
    980 	os->os_phys->os_flags = os->os_flags;
    981 
    982 	if (os->os_userused_dnode &&
    983 	    os->os_userused_dnode->dn_type != DMU_OT_NONE) {
    984 		os->os_userused_dnode->dn_zio = zio;
    985 		dnode_sync(os->os_userused_dnode, tx);
    986 		os->os_groupused_dnode->dn_zio = zio;
    987 		dnode_sync(os->os_groupused_dnode, tx);
    988 	}
    989 
    990 	txgoff = tx->tx_txg & TXG_MASK;
    991 
    992 	if (dmu_objset_userused_enabled(os)) {
    993 		newlist = &os->os_synced_dnodes;
    994 		/*
    995 		 * We must create the list here because it uses the
    996 		 * dn_dirty_link[] of this txg.
    997 		 */
    998 		list_create(newlist, sizeof (dnode_t),
    999 		    offsetof(dnode_t, dn_dirty_link[txgoff]));
   1000 	}
   1001 
   1002 	dmu_objset_sync_dnodes(&os->os_free_dnodes[txgoff], newlist, tx);
   1003 	dmu_objset_sync_dnodes(&os->os_dirty_dnodes[txgoff], newlist, tx);
   1004 
   1005 	list = &os->os_meta_dnode->dn_dirty_records[txgoff];
   1006 	while (dr = list_head(list)) {
   1007 		ASSERT(dr->dr_dbuf->db_level == 0);
   1008 		list_remove(list, dr);
   1009 		if (dr->dr_zio)
   1010 			zio_nowait(dr->dr_zio);
   1011 	}
   1012 	/*
   1013 	 * Free intent log blocks up to this tx.
   1014 	 */
   1015 	zil_sync(os->os_zil, tx);
   1016 	os->os_phys->os_zil_header = os->os_zil_header;
   1017 	zio_nowait(zio);
   1018 }
   1019 
   1020 static objset_used_cb_t *used_cbs[DMU_OST_NUMTYPES];
   1021 
   1022 void
   1023 dmu_objset_register_type(dmu_objset_type_t ost, objset_used_cb_t *cb)
   1024 {
   1025 	used_cbs[ost] = cb;
   1026 }
   1027 
   1028 boolean_t
   1029 dmu_objset_userused_enabled(objset_impl_t *os)
   1030 {
   1031 	return (spa_version(os->os_spa) >= SPA_VERSION_USERSPACE &&
   1032 	    used_cbs[os->os_phys->os_type] &&
   1033 	    os->os_userused_dnode);
   1034 }
   1035 
   1036 void
   1037 dmu_objset_do_userquota_callbacks(objset_impl_t *os, dmu_tx_t *tx)
   1038 {
   1039 	dnode_t *dn;
   1040 	list_t *list = &os->os_synced_dnodes;
   1041 	static const char zerobuf[DN_MAX_BONUSLEN] = {0};
   1042 
   1043 	ASSERT(list_head(list) == NULL || dmu_objset_userused_enabled(os));
   1044 
   1045 	while (dn = list_head(list)) {
   1046 		dmu_object_type_t bonustype;
   1047 
   1048 		ASSERT(!DMU_OBJECT_IS_SPECIAL(dn->dn_object));
   1049 		ASSERT(dn->dn_oldphys);
   1050 		ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE ||
   1051 		    dn->dn_phys->dn_flags &
   1052 		    DNODE_FLAG_USERUSED_ACCOUNTED);
   1053 
   1054 		/* Allocate the user/groupused objects if necessary. */
   1055 		if (os->os_userused_dnode->dn_type == DMU_OT_NONE) {
   1056 			VERIFY(0 == zap_create_claim(&os->os,
   1057 			    DMU_USERUSED_OBJECT,
   1058 			    DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx));
   1059 			VERIFY(0 == zap_create_claim(&os->os,
   1060 			    DMU_GROUPUSED_OBJECT,
   1061 			    DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx));
   1062 		}
   1063 
   1064 		/*
   1065 		 * If the object was not previously
   1066 		 * accounted, pretend that it was free.
   1067 		 */
   1068 		if (!(dn->dn_oldphys->dn_flags &
   1069 		    DNODE_FLAG_USERUSED_ACCOUNTED)) {
   1070 			bzero(dn->dn_oldphys, sizeof (dnode_phys_t));
   1071 		}
   1072 
   1073 		/*
   1074 		 * If the object was freed, use the previous bonustype.
   1075 		 */
   1076 		bonustype = dn->dn_phys->dn_bonustype ?
   1077 		    dn->dn_phys->dn_bonustype : dn->dn_oldphys->dn_bonustype;
   1078 		ASSERT(dn->dn_phys->dn_type != 0 ||
   1079 		    (bcmp(DN_BONUS(dn->dn_phys), zerobuf,
   1080 		    DN_MAX_BONUSLEN) == 0 &&
   1081 		    DN_USED_BYTES(dn->dn_phys) == 0));
   1082 		ASSERT(dn->dn_oldphys->dn_type != 0 ||
   1083 		    (bcmp(DN_BONUS(dn->dn_oldphys), zerobuf,
   1084 		    DN_MAX_BONUSLEN) == 0 &&
   1085 		    DN_USED_BYTES(dn->dn_oldphys) == 0));
   1086 		used_cbs[os->os_phys->os_type](&os->os, bonustype,
   1087 		    DN_BONUS(dn->dn_oldphys), DN_BONUS(dn->dn_phys),
   1088 		    DN_USED_BYTES(dn->dn_oldphys),
   1089 		    DN_USED_BYTES(dn->dn_phys), tx);
   1090 
   1091 		/*
   1092 		 * The mutex is needed here for interlock with dnode_allocate.
   1093 		 */
   1094 		mutex_enter(&dn->dn_mtx);
   1095 		zio_buf_free(dn->dn_oldphys, sizeof (dnode_phys_t));
   1096 		dn->dn_oldphys = NULL;
   1097 		mutex_exit(&dn->dn_mtx);
   1098 
   1099 		list_remove(list, dn);
   1100 		dnode_rele(dn, list);
   1101 	}
   1102 }
   1103 
   1104 boolean_t
   1105 dmu_objset_userspace_present(objset_t *os)
   1106 {
   1107 	return (os->os->os_phys->os_flags &
   1108 	    OBJSET_FLAG_USERACCOUNTING_COMPLETE);
   1109 }
   1110 
   1111 int
   1112 dmu_objset_userspace_upgrade(objset_t *os)
   1113 {
   1114 	uint64_t obj;
   1115 	int err = 0;
   1116 
   1117 	if (dmu_objset_userspace_present(os))
   1118 		return (0);
   1119 	if (!dmu_objset_userused_enabled(os->os))
   1120 		return (ENOTSUP);
   1121 	if (dmu_objset_is_snapshot(os))
   1122 		return (EINVAL);
   1123 
   1124 	/*
   1125 	 * We simply need to mark every object dirty, so that it will be
   1126 	 * synced out and now accounted.  If this is called
   1127 	 * concurrently, or if we already did some work before crashing,
   1128 	 * that's fine, since we track each object's accounted state
   1129 	 * independently.
   1130 	 */
   1131 
   1132 	for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 0)) {
   1133 		dmu_tx_t *tx;
   1134 		dmu_buf_t *db;
   1135 		int objerr;
   1136 
   1137 		if (issig(JUSTLOOKING) && issig(FORREAL))
   1138 			return (EINTR);
   1139 
   1140 		objerr = dmu_bonus_hold(os, obj, FTAG, &db);
   1141 		if (objerr)
   1142 			continue;
   1143 		tx = dmu_tx_create(os);
   1144 		dmu_tx_hold_bonus(tx, obj);
   1145 		objerr = dmu_tx_assign(tx, TXG_WAIT);
   1146 		if (objerr) {
   1147 			dmu_tx_abort(tx);
   1148 			continue;
   1149 		}
   1150 		dmu_buf_will_dirty(db, tx);
   1151 		dmu_buf_rele(db, FTAG);
   1152 		dmu_tx_commit(tx);
   1153 	}
   1154 
   1155 	os->os->os_flags |= OBJSET_FLAG_USERACCOUNTING_COMPLETE;
   1156 	txg_wait_synced(dmu_objset_pool(os), 0);
   1157 	return (0);
   1158 }
   1159 
   1160 void
   1161 dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
   1162     uint64_t *usedobjsp, uint64_t *availobjsp)
   1163 {
   1164 	dsl_dataset_space(os->os->os_dsl_dataset, refdbytesp, availbytesp,
   1165 	    usedobjsp, availobjsp);
   1166 }
   1167 
   1168 uint64_t
   1169 dmu_objset_fsid_guid(objset_t *os)
   1170 {
   1171 	return (dsl_dataset_fsid_guid(os->os->os_dsl_dataset));
   1172 }
   1173 
   1174 void
   1175 dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat)
   1176 {
   1177 	stat->dds_type = os->os->os_phys->os_type;
   1178 	if (os->os->os_dsl_dataset)
   1179 		dsl_dataset_fast_stat(os->os->os_dsl_dataset, stat);
   1180 }
   1181 
   1182 void
   1183 dmu_objset_stats(objset_t *os, nvlist_t *nv)
   1184 {
   1185 	ASSERT(os->os->os_dsl_dataset ||
   1186 	    os->os->os_phys->os_type == DMU_OST_META);
   1187 
   1188 	if (os->os->os_dsl_dataset != NULL)
   1189 		dsl_dataset_stats(os->os->os_dsl_dataset, nv);
   1190 
   1191 	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_TYPE,
   1192 	    os->os->os_phys->os_type);
   1193 	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERACCOUNTING,
   1194 	    dmu_objset_userspace_present(os));
   1195 }
   1196 
   1197 int
   1198 dmu_objset_is_snapshot(objset_t *os)
   1199 {
   1200 	if (os->os->os_dsl_dataset != NULL)
   1201 		return (dsl_dataset_is_snapshot(os->os->os_dsl_dataset));
   1202 	else
   1203 		return (B_FALSE);
   1204 }
   1205 
   1206 int
   1207 dmu_snapshot_realname(objset_t *os, char *name, char *real, int maxlen,
   1208     boolean_t *conflict)
   1209 {
   1210 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
   1211 	uint64_t ignored;
   1212 
   1213 	if (ds->ds_phys->ds_snapnames_zapobj == 0)
   1214 		return (ENOENT);
   1215 
   1216 	return (zap_lookup_norm(ds->ds_dir->dd_pool->dp_meta_objset,
   1217 	    ds->ds_phys->ds_snapnames_zapobj, name, 8, 1, &ignored, MT_FIRST,
   1218 	    real, maxlen, conflict));
   1219 }
   1220 
   1221 int
   1222 dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
   1223     uint64_t *idp, uint64_t *offp, boolean_t *case_conflict)
   1224 {
   1225 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
   1226 	zap_cursor_t cursor;
   1227 	zap_attribute_t attr;
   1228 
   1229 	if (ds->ds_phys->ds_snapnames_zapobj == 0)
   1230 		return (ENOENT);
   1231 
   1232 	zap_cursor_init_serialized(&cursor,
   1233 	    ds->ds_dir->dd_pool->dp_meta_objset,
   1234 	    ds->ds_phys->ds_snapnames_zapobj, *offp);
   1235 
   1236 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
   1237 		zap_cursor_fini(&cursor);
   1238 		return (ENOENT);
   1239 	}
   1240 
   1241 	if (strlen(attr.za_name) + 1 > namelen) {
   1242 		zap_cursor_fini(&cursor);
   1243 		return (ENAMETOOLONG);
   1244 	}
   1245 
   1246 	(void) strcpy(name, attr.za_name);
   1247 	if (idp)
   1248 		*idp = attr.za_first_integer;
   1249 	if (case_conflict)
   1250 		*case_conflict = attr.za_normalization_conflict;
   1251 	zap_cursor_advance(&cursor);
   1252 	*offp = zap_cursor_serialize(&cursor);
   1253 	zap_cursor_fini(&cursor);
   1254 
   1255 	return (0);
   1256 }
   1257 
   1258 int
   1259 dmu_dir_list_next(objset_t *os, int namelen, char *name,
   1260     uint64_t *idp, uint64_t *offp)
   1261 {
   1262 	dsl_dir_t *dd = os->os->os_dsl_dataset->ds_dir;
   1263 	zap_cursor_t cursor;
   1264 	zap_attribute_t attr;
   1265 
   1266 	/* there is no next dir on a snapshot! */
   1267 	if (os->os->os_dsl_dataset->ds_object !=
   1268 	    dd->dd_phys->dd_head_dataset_obj)
   1269 		return (ENOENT);
   1270 
   1271 	zap_cursor_init_serialized(&cursor,
   1272 	    dd->dd_pool->dp_meta_objset,
   1273 	    dd->dd_phys->dd_child_dir_zapobj, *offp);
   1274 
   1275 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
   1276 		zap_cursor_fini(&cursor);
   1277 		return (ENOENT);
   1278 	}
   1279 
   1280 	if (strlen(attr.za_name) + 1 > namelen) {
   1281 		zap_cursor_fini(&cursor);
   1282 		return (ENAMETOOLONG);
   1283 	}
   1284 
   1285 	(void) strcpy(name, attr.za_name);
   1286 	if (idp)
   1287 		*idp = attr.za_first_integer;
   1288 	zap_cursor_advance(&cursor);
   1289 	*offp = zap_cursor_serialize(&cursor);
   1290 	zap_cursor_fini(&cursor);
   1291 
   1292 	return (0);
   1293 }
   1294 
   1295 struct findarg {
   1296 	int (*func)(char *, void *);
   1297 	void *arg;
   1298 };
   1299 
   1300 /* ARGSUSED */
   1301 static int
   1302 findfunc(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
   1303 {
   1304 	struct findarg *fa = arg;
   1305 	return (fa->func((char *)dsname, fa->arg));
   1306 }
   1307 
   1308 /*
   1309  * Find all objsets under name, and for each, call 'func(child_name, arg)'.
   1310  * Perhaps change all callers to use dmu_objset_find_spa()?
   1311  */
   1312 int
   1313 dmu_objset_find(char *name, int func(char *, void *), void *arg, int flags)
   1314 {
   1315 	struct findarg fa;
   1316 	fa.func = func;
   1317 	fa.arg = arg;
   1318 	return (dmu_objset_find_spa(NULL, name, findfunc, &fa, flags));
   1319 }
   1320 
   1321 /*
   1322  * Find all objsets under name, call func on each
   1323  */
   1324 int
   1325 dmu_objset_find_spa(spa_t *spa, const char *name,
   1326     int func(spa_t *, uint64_t, const char *, void *), void *arg, int flags)
   1327 {
   1328 	dsl_dir_t *dd;
   1329 	dsl_pool_t *dp;
   1330 	dsl_dataset_t *ds;
   1331 	zap_cursor_t zc;
   1332 	zap_attribute_t *attr;
   1333 	char *child;
   1334 	uint64_t thisobj;
   1335 	int err;
   1336 
   1337 	if (name == NULL)
   1338 		name = spa_name(spa);
   1339 	err = dsl_dir_open_spa(spa, name, FTAG, &dd, NULL);
   1340 	if (err)
   1341 		return (err);
   1342 
   1343 	/* Don't visit hidden ($MOS & $ORIGIN) objsets. */
   1344 	if (dd->dd_myname[0] == '$') {
   1345 		dsl_dir_close(dd, FTAG);
   1346 		return (0);
   1347 	}
   1348 
   1349 	thisobj = dd->dd_phys->dd_head_dataset_obj;
   1350 	attr = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
   1351 	dp = dd->dd_pool;
   1352 
   1353 	/*
   1354 	 * Iterate over all children.
   1355 	 */
   1356 	if (flags & DS_FIND_CHILDREN) {
   1357 		for (zap_cursor_init(&zc, dp->dp_meta_objset,
   1358 		    dd->dd_phys->dd_child_dir_zapobj);
   1359 		    zap_cursor_retrieve(&zc, attr) == 0;
   1360 		    (void) zap_cursor_advance(&zc)) {
   1361 			ASSERT(attr->za_integer_length == sizeof (uint64_t));
   1362 			ASSERT(attr->za_num_integers == 1);
   1363 
   1364 			child = kmem_alloc(MAXPATHLEN, KM_SLEEP);
   1365 			(void) strcpy(child, name);
   1366 			(void) strcat(child, "/");
   1367 			(void) strcat(child, attr->za_name);
   1368 			err = dmu_objset_find_spa(spa, child, func, arg, flags);
   1369 			kmem_free(child, MAXPATHLEN);
   1370 			if (err)
   1371 				break;
   1372 		}
   1373 		zap_cursor_fini(&zc);
   1374 
   1375 		if (err) {
   1376 			dsl_dir_close(dd, FTAG);
   1377 			kmem_free(attr, sizeof (zap_attribute_t));
   1378 			return (err);
   1379 		}
   1380 	}
   1381 
   1382 	/*
   1383 	 * Iterate over all snapshots.
   1384 	 */
   1385 	if (flags & DS_FIND_SNAPSHOTS) {
   1386 		if (!dsl_pool_sync_context(dp))
   1387 			rw_enter(&dp->dp_config_rwlock, RW_READER);
   1388 		err = dsl_dataset_hold_obj(dp, thisobj, FTAG, &ds);
   1389 		if (!dsl_pool_sync_context(dp))
   1390 			rw_exit(&dp->dp_config_rwlock);
   1391 
   1392 		if (err == 0) {
   1393 			uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
   1394 			dsl_dataset_rele(ds, FTAG);
   1395 
   1396 			for (zap_cursor_init(&zc, dp->dp_meta_objset, snapobj);
   1397 			    zap_cursor_retrieve(&zc, attr) == 0;
   1398 			    (void) zap_cursor_advance(&zc)) {
   1399 				ASSERT(attr->za_integer_length ==
   1400 				    sizeof (uint64_t));
   1401 				ASSERT(attr->za_num_integers == 1);
   1402 
   1403 				child = kmem_alloc(MAXPATHLEN, KM_SLEEP);
   1404 				(void) strcpy(child, name);
   1405 				(void) strcat(child, "@");
   1406 				(void) strcat(child, attr->za_name);
   1407 				err = func(spa, attr->za_first_integer,
   1408 				    child, arg);
   1409 				kmem_free(child, MAXPATHLEN);
   1410 				if (err)
   1411 					break;
   1412 			}
   1413 			zap_cursor_fini(&zc);
   1414 		}
   1415 	}
   1416 
   1417 	dsl_dir_close(dd, FTAG);
   1418 	kmem_free(attr, sizeof (zap_attribute_t));
   1419 
   1420 	if (err)
   1421 		return (err);
   1422 
   1423 	/*
   1424 	 * Apply to self if appropriate.
   1425 	 */
   1426 	err = func(spa, thisobj, name, arg);
   1427 	return (err);
   1428 }
   1429 
   1430 /* ARGSUSED */
   1431 int
   1432 dmu_objset_prefetch(char *name, void *arg)
   1433 {
   1434 	dsl_dataset_t *ds;
   1435 
   1436 	if (dsl_dataset_hold(name, FTAG, &ds))
   1437 		return (0);
   1438 
   1439 	if (!BP_IS_HOLE(&ds->ds_phys->ds_bp)) {
   1440 		mutex_enter(&ds->ds_opening_lock);
   1441 		if (!dsl_dataset_get_user_ptr(ds)) {
   1442 			uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
   1443 			zbookmark_t zb;
   1444 
   1445 			zb.zb_objset = ds->ds_object;
   1446 			zb.zb_object = 0;
   1447 			zb.zb_level = -1;
   1448 			zb.zb_blkid = 0;
   1449 
   1450 			(void) arc_read_nolock(NULL, dsl_dataset_get_spa(ds),
   1451 			    &ds->ds_phys->ds_bp, NULL, NULL,
   1452 			    ZIO_PRIORITY_ASYNC_READ,
   1453 			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
   1454 			    &aflags, &zb);
   1455 		}
   1456 		mutex_exit(&ds->ds_opening_lock);
   1457 	}
   1458 
   1459 	dsl_dataset_rele(ds, FTAG);
   1460 	return (0);
   1461 }
   1462 
   1463 void
   1464 dmu_objset_set_user(objset_t *os, void *user_ptr)
   1465 {
   1466 	ASSERT(MUTEX_HELD(&os->os->os_user_ptr_lock));
   1467 	os->os->os_user_ptr = user_ptr;
   1468 }
   1469 
   1470 void *
   1471 dmu_objset_get_user(objset_t *os)
   1472 {
   1473 	ASSERT(MUTEX_HELD(&os->os->os_user_ptr_lock));
   1474 	return (os->os->os_user_ptr);
   1475 }
   1476