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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/zap.h>
     40 #include <sys/zil.h>
     41 #include <sys/dmu_impl.h>
     42 #include <sys/zfs_ioctl.h>
     43 
     44 spa_t *
     45 dmu_objset_spa(objset_t *os)
     46 {
     47 	return (os->os_spa);
     48 }
     49 
     50 zilog_t *
     51 dmu_objset_zil(objset_t *os)
     52 {
     53 	return (os->os_zil);
     54 }
     55 
     56 dsl_pool_t *
     57 dmu_objset_pool(objset_t *os)
     58 {
     59 	dsl_dataset_t *ds;
     60 
     61 	if ((ds = os->os_dsl_dataset) != NULL && ds->ds_dir)
     62 		return (ds->ds_dir->dd_pool);
     63 	else
     64 		return (spa_get_dsl(os->os_spa));
     65 }
     66 
     67 dsl_dataset_t *
     68 dmu_objset_ds(objset_t *os)
     69 {
     70 	return (os->os_dsl_dataset);
     71 }
     72 
     73 dmu_objset_type_t
     74 dmu_objset_type(objset_t *os)
     75 {
     76 	return (os->os_phys->os_type);
     77 }
     78 
     79 void
     80 dmu_objset_name(objset_t *os, char *buf)
     81 {
     82 	dsl_dataset_name(os->os_dsl_dataset, buf);
     83 }
     84 
     85 uint64_t
     86 dmu_objset_id(objset_t *os)
     87 {
     88 	dsl_dataset_t *ds = os->os_dsl_dataset;
     89 
     90 	return (ds ? ds->ds_object : 0);
     91 }
     92 
     93 uint64_t
     94 dmu_objset_logbias(objset_t *os)
     95 {
     96 	return (os->os_logbias);
     97 }
     98 
     99 static void
    100 checksum_changed_cb(void *arg, uint64_t newval)
    101 {
    102 	objset_t *os = arg;
    103 
    104 	/*
    105 	 * Inheritance should have been done by now.
    106 	 */
    107 	ASSERT(newval != ZIO_CHECKSUM_INHERIT);
    108 
    109 	os->os_checksum = zio_checksum_select(newval, ZIO_CHECKSUM_ON_VALUE);
    110 }
    111 
    112 static void
    113 compression_changed_cb(void *arg, uint64_t newval)
    114 {
    115 	objset_t *os = arg;
    116 
    117 	/*
    118 	 * Inheritance and range checking should have been done by now.
    119 	 */
    120 	ASSERT(newval != ZIO_COMPRESS_INHERIT);
    121 
    122 	os->os_compress = zio_compress_select(newval, ZIO_COMPRESS_ON_VALUE);
    123 }
    124 
    125 static void
    126 copies_changed_cb(void *arg, uint64_t newval)
    127 {
    128 	objset_t *os = arg;
    129 
    130 	/*
    131 	 * Inheritance and range checking should have been done by now.
    132 	 */
    133 	ASSERT(newval > 0);
    134 	ASSERT(newval <= spa_max_replication(os->os_spa));
    135 
    136 	os->os_copies = newval;
    137 }
    138 
    139 static void
    140 dedup_changed_cb(void *arg, uint64_t newval)
    141 {
    142 	objset_t *os = arg;
    143 	spa_t *spa = os->os_spa;
    144 	enum zio_checksum checksum;
    145 
    146 	/*
    147 	 * Inheritance should have been done by now.
    148 	 */
    149 	ASSERT(newval != ZIO_CHECKSUM_INHERIT);
    150 
    151 	checksum = zio_checksum_dedup_select(spa, newval, ZIO_CHECKSUM_OFF);
    152 
    153 	os->os_dedup_checksum = checksum & ZIO_CHECKSUM_MASK;
    154 	os->os_dedup_verify = !!(checksum & ZIO_CHECKSUM_VERIFY);
    155 }
    156 
    157 static void
    158 primary_cache_changed_cb(void *arg, uint64_t newval)
    159 {
    160 	objset_t *os = arg;
    161 
    162 	/*
    163 	 * Inheritance and range checking should have been done by now.
    164 	 */
    165 	ASSERT(newval == ZFS_CACHE_ALL || newval == ZFS_CACHE_NONE ||
    166 	    newval == ZFS_CACHE_METADATA);
    167 
    168 	os->os_primary_cache = newval;
    169 }
    170 
    171 static void
    172 secondary_cache_changed_cb(void *arg, uint64_t newval)
    173 {
    174 	objset_t *os = arg;
    175 
    176 	/*
    177 	 * Inheritance and range checking should have been done by now.
    178 	 */
    179 	ASSERT(newval == ZFS_CACHE_ALL || newval == ZFS_CACHE_NONE ||
    180 	    newval == ZFS_CACHE_METADATA);
    181 
    182 	os->os_secondary_cache = newval;
    183 }
    184 
    185 static void
    186 logbias_changed_cb(void *arg, uint64_t newval)
    187 {
    188 	objset_t *os = arg;
    189 
    190 	ASSERT(newval == ZFS_LOGBIAS_LATENCY ||
    191 	    newval == ZFS_LOGBIAS_THROUGHPUT);
    192 	os->os_logbias = newval;
    193 	if (os->os_zil)
    194 		zil_set_logbias(os->os_zil, newval);
    195 }
    196 
    197 void
    198 dmu_objset_byteswap(void *buf, size_t size)
    199 {
    200 	objset_phys_t *osp = buf;
    201 
    202 	ASSERT(size == OBJSET_OLD_PHYS_SIZE || size == sizeof (objset_phys_t));
    203 	dnode_byteswap(&osp->os_meta_dnode);
    204 	byteswap_uint64_array(&osp->os_zil_header, sizeof (zil_header_t));
    205 	osp->os_type = BSWAP_64(osp->os_type);
    206 	osp->os_flags = BSWAP_64(osp->os_flags);
    207 	if (size == sizeof (objset_phys_t)) {
    208 		dnode_byteswap(&osp->os_userused_dnode);
    209 		dnode_byteswap(&osp->os_groupused_dnode);
    210 	}
    211 }
    212 
    213 int
    214 dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
    215     objset_t **osp)
    216 {
    217 	objset_t *os;
    218 	int i, err;
    219 
    220 	ASSERT(ds == NULL || MUTEX_HELD(&ds->ds_opening_lock));
    221 
    222 	os = kmem_zalloc(sizeof (objset_t), KM_SLEEP);
    223 	os->os_dsl_dataset = ds;
    224 	os->os_spa = spa;
    225 	os->os_rootbp = bp;
    226 	if (!BP_IS_HOLE(os->os_rootbp)) {
    227 		uint32_t aflags = ARC_WAIT;
    228 		zbookmark_t zb;
    229 		SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
    230 		    ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
    231 
    232 		if (DMU_OS_IS_L2CACHEABLE(os))
    233 			aflags |= ARC_L2CACHE;
    234 
    235 		dprintf_bp(os->os_rootbp, "reading %s", "");
    236 		/*
    237 		 * NB: when bprewrite scrub can change the bp,
    238 		 * and this is called from dmu_objset_open_ds_os, the bp
    239 		 * could change, and we'll need a lock.
    240 		 */
    241 		err = arc_read_nolock(NULL, spa, os->os_rootbp,
    242 		    arc_getbuf_func, &os->os_phys_buf,
    243 		    ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL, &aflags, &zb);
    244 		if (err) {
    245 			kmem_free(os, sizeof (objset_t));
    246 			/* convert checksum errors into IO errors */
    247 			if (err == ECKSUM)
    248 				err = EIO;
    249 			return (err);
    250 		}
    251 
    252 		/* Increase the blocksize if we are permitted. */
    253 		if (spa_version(spa) >= SPA_VERSION_USERSPACE &&
    254 		    arc_buf_size(os->os_phys_buf) < sizeof (objset_phys_t)) {
    255 			arc_buf_t *buf = arc_buf_alloc(spa,
    256 			    sizeof (objset_phys_t), &os->os_phys_buf,
    257 			    ARC_BUFC_METADATA);
    258 			bzero(buf->b_data, sizeof (objset_phys_t));
    259 			bcopy(os->os_phys_buf->b_data, buf->b_data,
    260 			    arc_buf_size(os->os_phys_buf));
    261 			(void) arc_buf_remove_ref(os->os_phys_buf,
    262 			    &os->os_phys_buf);
    263 			os->os_phys_buf = buf;
    264 		}
    265 
    266 		os->os_phys = os->os_phys_buf->b_data;
    267 		os->os_flags = os->os_phys->os_flags;
    268 	} else {
    269 		int size = spa_version(spa) >= SPA_VERSION_USERSPACE ?
    270 		    sizeof (objset_phys_t) : OBJSET_OLD_PHYS_SIZE;
    271 		os->os_phys_buf = arc_buf_alloc(spa, size,
    272 		    &os->os_phys_buf, ARC_BUFC_METADATA);
    273 		os->os_phys = os->os_phys_buf->b_data;
    274 		bzero(os->os_phys, size);
    275 	}
    276 
    277 	/*
    278 	 * Note: the changed_cb will be called once before the register
    279 	 * func returns, thus changing the checksum/compression from the
    280 	 * default (fletcher2/off).  Snapshots don't need to know about
    281 	 * checksum/compression/copies.
    282 	 */
    283 	if (ds) {
    284 		err = dsl_prop_register(ds, "primarycache",
    285 		    primary_cache_changed_cb, os);
    286 		if (err == 0)
    287 			err = dsl_prop_register(ds, "secondarycache",
    288 			    secondary_cache_changed_cb, os);
    289 		if (!dsl_dataset_is_snapshot(ds)) {
    290 			if (err == 0)
    291 				err = dsl_prop_register(ds, "checksum",
    292 				    checksum_changed_cb, os);
    293 			if (err == 0)
    294 				err = dsl_prop_register(ds, "compression",
    295 				    compression_changed_cb, os);
    296 			if (err == 0)
    297 				err = dsl_prop_register(ds, "copies",
    298 				    copies_changed_cb, os);
    299 			if (err == 0)
    300 				err = dsl_prop_register(ds, "dedup",
    301 				    dedup_changed_cb, os);
    302 			if (err == 0)
    303 				err = dsl_prop_register(ds, "logbias",
    304 				    logbias_changed_cb, os);
    305 		}
    306 		if (err) {
    307 			VERIFY(arc_buf_remove_ref(os->os_phys_buf,
    308 			    &os->os_phys_buf) == 1);
    309 			kmem_free(os, sizeof (objset_t));
    310 			return (err);
    311 		}
    312 	} else if (ds == NULL) {
    313 		/* It's the meta-objset. */
    314 		os->os_checksum = ZIO_CHECKSUM_FLETCHER_4;
    315 		os->os_compress = ZIO_COMPRESS_LZJB;
    316 		os->os_copies = spa_max_replication(spa);
    317 		os->os_dedup_checksum = ZIO_CHECKSUM_OFF;
    318 		os->os_dedup_verify = 0;
    319 		os->os_logbias = 0;
    320 		os->os_primary_cache = ZFS_CACHE_ALL;
    321 		os->os_secondary_cache = ZFS_CACHE_ALL;
    322 	}
    323 
    324 	os->os_zil_header = os->os_phys->os_zil_header;
    325 	os->os_zil = zil_alloc(os, &os->os_zil_header);
    326 
    327 	for (i = 0; i < TXG_SIZE; i++) {
    328 		list_create(&os->os_dirty_dnodes[i], sizeof (dnode_t),
    329 		    offsetof(dnode_t, dn_dirty_link[i]));
    330 		list_create(&os->os_free_dnodes[i], sizeof (dnode_t),
    331 		    offsetof(dnode_t, dn_dirty_link[i]));
    332 	}
    333 	list_create(&os->os_dnodes, sizeof (dnode_t),
    334 	    offsetof(dnode_t, dn_link));
    335 	list_create(&os->os_downgraded_dbufs, sizeof (dmu_buf_impl_t),
    336 	    offsetof(dmu_buf_impl_t, db_link));
    337 
    338 	mutex_init(&os->os_lock, NULL, MUTEX_DEFAULT, NULL);
    339 	mutex_init(&os->os_obj_lock, NULL, MUTEX_DEFAULT, NULL);
    340 	mutex_init(&os->os_user_ptr_lock, NULL, MUTEX_DEFAULT, NULL);
    341 
    342 	os->os_meta_dnode = dnode_special_open(os,
    343 	    &os->os_phys->os_meta_dnode, DMU_META_DNODE_OBJECT);
    344 	if (arc_buf_size(os->os_phys_buf) >= sizeof (objset_phys_t)) {
    345 		os->os_userused_dnode = dnode_special_open(os,
    346 		    &os->os_phys->os_userused_dnode, DMU_USERUSED_OBJECT);
    347 		os->os_groupused_dnode = dnode_special_open(os,
    348 		    &os->os_phys->os_groupused_dnode, DMU_GROUPUSED_OBJECT);
    349 	}
    350 
    351 	/*
    352 	 * We should be the only thread trying to do this because we
    353 	 * have ds_opening_lock
    354 	 */
    355 	if (ds) {
    356 		mutex_enter(&ds->ds_lock);
    357 		ASSERT(ds->ds_objset == NULL);
    358 		ds->ds_objset = os;
    359 		mutex_exit(&ds->ds_lock);
    360 	}
    361 
    362 	*osp = os;
    363 	return (0);
    364 }
    365 
    366 int
    367 dmu_objset_from_ds(dsl_dataset_t *ds, objset_t **osp)
    368 {
    369 	int err = 0;
    370 
    371 	mutex_enter(&ds->ds_opening_lock);
    372 	*osp = ds->ds_objset;
    373 	if (*osp == NULL) {
    374 		err = dmu_objset_open_impl(dsl_dataset_get_spa(ds),
    375 		    ds, &ds->ds_phys->ds_bp, osp);
    376 	}
    377 	mutex_exit(&ds->ds_opening_lock);
    378 	return (err);
    379 }
    380 
    381 /* called from zpl */
    382 int
    383 dmu_objset_hold(const char *name, void *tag, objset_t **osp)
    384 {
    385 	dsl_dataset_t *ds;
    386 	int err;
    387 
    388 	err = dsl_dataset_hold(name, tag, &ds);
    389 	if (err)
    390 		return (err);
    391 
    392 	err = dmu_objset_from_ds(ds, osp);
    393 	if (err)
    394 		dsl_dataset_rele(ds, tag);
    395 
    396 	return (err);
    397 }
    398 
    399 /* called from zpl */
    400 int
    401 dmu_objset_own(const char *name, dmu_objset_type_t type,
    402     boolean_t readonly, void *tag, objset_t **osp)
    403 {
    404 	dsl_dataset_t *ds;
    405 	int err;
    406 
    407 	err = dsl_dataset_own(name, B_FALSE, tag, &ds);
    408 	if (err)
    409 		return (err);
    410 
    411 	err = dmu_objset_from_ds(ds, osp);
    412 	if (err) {
    413 		dsl_dataset_disown(ds, tag);
    414 	} else if (type != DMU_OST_ANY && type != (*osp)->os_phys->os_type) {
    415 		dmu_objset_disown(*osp, tag);
    416 		return (EINVAL);
    417 	} else if (!readonly && dsl_dataset_is_snapshot(ds)) {
    418 		dmu_objset_disown(*osp, tag);
    419 		return (EROFS);
    420 	}
    421 	return (err);
    422 }
    423 
    424 void
    425 dmu_objset_rele(objset_t *os, void *tag)
    426 {
    427 	dsl_dataset_rele(os->os_dsl_dataset, tag);
    428 }
    429 
    430 void
    431 dmu_objset_disown(objset_t *os, void *tag)
    432 {
    433 	dsl_dataset_disown(os->os_dsl_dataset, tag);
    434 }
    435 
    436 int
    437 dmu_objset_evict_dbufs(objset_t *os)
    438 {
    439 	dnode_t *dn;
    440 
    441 	mutex_enter(&os->os_lock);
    442 
    443 	/* process the mdn last, since the other dnodes have holds on it */
    444 	list_remove(&os->os_dnodes, os->os_meta_dnode);
    445 	list_insert_tail(&os->os_dnodes, os->os_meta_dnode);
    446 
    447 	/*
    448 	 * Find the first dnode with holds.  We have to do this dance
    449 	 * because dnode_add_ref() only works if you already have a
    450 	 * hold.  If there are no holds then it has no dbufs so OK to
    451 	 * skip.
    452 	 */
    453 	for (dn = list_head(&os->os_dnodes);
    454 	    dn && !dnode_add_ref(dn, FTAG);
    455 	    dn = list_next(&os->os_dnodes, dn))
    456 		continue;
    457 
    458 	while (dn) {
    459 		dnode_t *next_dn = dn;
    460 
    461 		do {
    462 			next_dn = list_next(&os->os_dnodes, next_dn);
    463 		} while (next_dn && !dnode_add_ref(next_dn, FTAG));
    464 
    465 		mutex_exit(&os->os_lock);
    466 		dnode_evict_dbufs(dn);
    467 		dnode_rele(dn, FTAG);
    468 		mutex_enter(&os->os_lock);
    469 		dn = next_dn;
    470 	}
    471 	mutex_exit(&os->os_lock);
    472 	return (list_head(&os->os_dnodes) != os->os_meta_dnode);
    473 }
    474 
    475 void
    476 dmu_objset_evict(objset_t *os)
    477 {
    478 	dsl_dataset_t *ds = os->os_dsl_dataset;
    479 
    480 	for (int t = 0; t < TXG_SIZE; t++)
    481 		ASSERT(!dmu_objset_is_dirty(os, t));
    482 
    483 	if (ds) {
    484 		if (!dsl_dataset_is_snapshot(ds)) {
    485 			VERIFY(0 == dsl_prop_unregister(ds, "checksum",
    486 			    checksum_changed_cb, os));
    487 			VERIFY(0 == dsl_prop_unregister(ds, "compression",
    488 			    compression_changed_cb, os));
    489 			VERIFY(0 == dsl_prop_unregister(ds, "copies",
    490 			    copies_changed_cb, os));
    491 			VERIFY(0 == dsl_prop_unregister(ds, "dedup",
    492 			    dedup_changed_cb, os));
    493 			VERIFY(0 == dsl_prop_unregister(ds, "logbias",
    494 			    logbias_changed_cb, os));
    495 		}
    496 		VERIFY(0 == dsl_prop_unregister(ds, "primarycache",
    497 		    primary_cache_changed_cb, os));
    498 		VERIFY(0 == dsl_prop_unregister(ds, "secondarycache",
    499 		    secondary_cache_changed_cb, os));
    500 	}
    501 
    502 	/*
    503 	 * We should need only a single pass over the dnode list, since
    504 	 * nothing can be added to the list at this point.
    505 	 */
    506 	(void) dmu_objset_evict_dbufs(os);
    507 
    508 	dnode_special_close(os->os_meta_dnode);
    509 	if (os->os_userused_dnode) {
    510 		dnode_special_close(os->os_userused_dnode);
    511 		dnode_special_close(os->os_groupused_dnode);
    512 	}
    513 	zil_free(os->os_zil);
    514 
    515 	ASSERT3P(list_head(&os->os_dnodes), ==, NULL);
    516 
    517 	VERIFY(arc_buf_remove_ref(os->os_phys_buf, &os->os_phys_buf) == 1);
    518 	mutex_destroy(&os->os_lock);
    519 	mutex_destroy(&os->os_obj_lock);
    520 	mutex_destroy(&os->os_user_ptr_lock);
    521 	kmem_free(os, sizeof (objset_t));
    522 }
    523 
    524 timestruc_t
    525 dmu_objset_snap_cmtime(objset_t *os)
    526 {
    527 	return (dsl_dir_snap_cmtime(os->os_dsl_dataset->ds_dir));
    528 }
    529 
    530 /* called from dsl for meta-objset */
    531 objset_t *
    532 dmu_objset_create_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
    533     dmu_objset_type_t type, dmu_tx_t *tx)
    534 {
    535 	objset_t *os;
    536 	dnode_t *mdn;
    537 
    538 	ASSERT(dmu_tx_is_syncing(tx));
    539 	if (ds)
    540 		mutex_enter(&ds->ds_opening_lock);
    541 	VERIFY(0 == dmu_objset_open_impl(spa, ds, bp, &os));
    542 	if (ds)
    543 		mutex_exit(&ds->ds_opening_lock);
    544 	mdn = os->os_meta_dnode;
    545 
    546 	dnode_allocate(mdn, DMU_OT_DNODE, 1 << DNODE_BLOCK_SHIFT,
    547 	    DN_MAX_INDBLKSHIFT, DMU_OT_NONE, 0, tx);
    548 
    549 	/*
    550 	 * We don't want to have to increase the meta-dnode's nlevels
    551 	 * later, because then we could do it in quescing context while
    552 	 * we are also accessing it in open context.
    553 	 *
    554 	 * This precaution is not necessary for the MOS (ds == NULL),
    555 	 * because the MOS is only updated in syncing context.
    556 	 * This is most fortunate: the MOS is the only objset that
    557 	 * needs to be synced multiple times as spa_sync() iterates
    558 	 * to convergence, so minimizing its dn_nlevels matters.
    559 	 */
    560 	if (ds != NULL) {
    561 		int levels = 1;
    562 
    563 		/*
    564 		 * Determine the number of levels necessary for the meta-dnode
    565 		 * to contain DN_MAX_OBJECT dnodes.
    566 		 */
    567 		while ((uint64_t)mdn->dn_nblkptr << (mdn->dn_datablkshift +
    568 		    (levels - 1) * (mdn->dn_indblkshift - SPA_BLKPTRSHIFT)) <
    569 		    DN_MAX_OBJECT * sizeof (dnode_phys_t))
    570 			levels++;
    571 
    572 		mdn->dn_next_nlevels[tx->tx_txg & TXG_MASK] =
    573 		    mdn->dn_nlevels = levels;
    574 	}
    575 
    576 	ASSERT(type != DMU_OST_NONE);
    577 	ASSERT(type != DMU_OST_ANY);
    578 	ASSERT(type < DMU_OST_NUMTYPES);
    579 	os->os_phys->os_type = type;
    580 	if (dmu_objset_userused_enabled(os)) {
    581 		os->os_phys->os_flags |= OBJSET_FLAG_USERACCOUNTING_COMPLETE;
    582 		os->os_flags = os->os_phys->os_flags;
    583 	}
    584 
    585 	dsl_dataset_dirty(ds, tx);
    586 
    587 	return (os);
    588 }
    589 
    590 struct oscarg {
    591 	void (*userfunc)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx);
    592 	void *userarg;
    593 	dsl_dataset_t *clone_origin;
    594 	const char *lastname;
    595 	dmu_objset_type_t type;
    596 	uint64_t flags;
    597 };
    598 
    599 /*ARGSUSED*/
    600 static int
    601 dmu_objset_create_check(void *arg1, void *arg2, dmu_tx_t *tx)
    602 {
    603 	dsl_dir_t *dd = arg1;
    604 	struct oscarg *oa = arg2;
    605 	objset_t *mos = dd->dd_pool->dp_meta_objset;
    606 	int err;
    607 	uint64_t ddobj;
    608 
    609 	err = zap_lookup(mos, dd->dd_phys->dd_child_dir_zapobj,
    610 	    oa->lastname, sizeof (uint64_t), 1, &ddobj);
    611 	if (err != ENOENT)
    612 		return (err ? err : EEXIST);
    613 
    614 	if (oa->clone_origin != NULL) {
    615 		/* You can't clone across pools. */
    616 		if (oa->clone_origin->ds_dir->dd_pool != dd->dd_pool)
    617 			return (EXDEV);
    618 
    619 		/* You can only clone snapshots, not the head datasets. */
    620 		if (!dsl_dataset_is_snapshot(oa->clone_origin))
    621 			return (EINVAL);
    622 	}
    623 
    624 	return (0);
    625 }
    626 
    627 static void
    628 dmu_objset_create_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
    629 {
    630 	dsl_dir_t *dd = arg1;
    631 	struct oscarg *oa = arg2;
    632 	uint64_t dsobj;
    633 
    634 	ASSERT(dmu_tx_is_syncing(tx));
    635 
    636 	dsobj = dsl_dataset_create_sync(dd, oa->lastname,
    637 	    oa->clone_origin, oa->flags, cr, tx);
    638 
    639 	if (oa->clone_origin == NULL) {
    640 		dsl_dataset_t *ds;
    641 		blkptr_t *bp;
    642 		objset_t *os;
    643 
    644 		VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, dsobj,
    645 		    FTAG, &ds));
    646 		bp = dsl_dataset_get_blkptr(ds);
    647 		ASSERT(BP_IS_HOLE(bp));
    648 
    649 		os = dmu_objset_create_impl(dsl_dataset_get_spa(ds),
    650 		    ds, bp, oa->type, tx);
    651 
    652 		if (oa->userfunc)
    653 			oa->userfunc(os, oa->userarg, cr, tx);
    654 		dsl_dataset_rele(ds, FTAG);
    655 	}
    656 
    657 	spa_history_internal_log(LOG_DS_CREATE, dd->dd_pool->dp_spa,
    658 	    tx, cr, "dataset = %llu", dsobj);
    659 }
    660 
    661 int
    662 dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
    663     void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg)
    664 {
    665 	dsl_dir_t *pdd;
    666 	const char *tail;
    667 	int err = 0;
    668 	struct oscarg oa = { 0 };
    669 
    670 	ASSERT(strchr(name, '@') == NULL);
    671 	err = dsl_dir_open(name, FTAG, &pdd, &tail);
    672 	if (err)
    673 		return (err);
    674 	if (tail == NULL) {
    675 		dsl_dir_close(pdd, FTAG);
    676 		return (EEXIST);
    677 	}
    678 
    679 	oa.userfunc = func;
    680 	oa.userarg = arg;
    681 	oa.lastname = tail;
    682 	oa.type = type;
    683 	oa.flags = flags;
    684 
    685 	err = dsl_sync_task_do(pdd->dd_pool, dmu_objset_create_check,
    686 	    dmu_objset_create_sync, pdd, &oa, 5);
    687 	dsl_dir_close(pdd, FTAG);
    688 	return (err);
    689 }
    690 
    691 int
    692 dmu_objset_clone(const char *name, dsl_dataset_t *clone_origin, uint64_t flags)
    693 {
    694 	dsl_dir_t *pdd;
    695 	const char *tail;
    696 	int err = 0;
    697 	struct oscarg oa = { 0 };
    698 
    699 	ASSERT(strchr(name, '@') == NULL);
    700 	err = dsl_dir_open(name, FTAG, &pdd, &tail);
    701 	if (err)
    702 		return (err);
    703 	if (tail == NULL) {
    704 		dsl_dir_close(pdd, FTAG);
    705 		return (EEXIST);
    706 	}
    707 
    708 	oa.lastname = tail;
    709 	oa.clone_origin = clone_origin;
    710 	oa.flags = flags;
    711 
    712 	err = dsl_sync_task_do(pdd->dd_pool, dmu_objset_create_check,
    713 	    dmu_objset_create_sync, pdd, &oa, 5);
    714 	dsl_dir_close(pdd, FTAG);
    715 	return (err);
    716 }
    717 
    718 int
    719 dmu_objset_destroy(const char *name, boolean_t defer)
    720 {
    721 	dsl_dataset_t *ds;
    722 	int error;
    723 
    724 	/*
    725 	 * dsl_dataset_destroy() can free any claimed-but-unplayed
    726 	 * intent log, but if there is an active log, it has blocks that
    727 	 * are allocated, but may not yet be reflected in the on-disk
    728 	 * structure.  Only the ZIL knows how to free them, so we have
    729 	 * to call into it here.
    730 	 */
    731 	error = dsl_dataset_own(name, B_TRUE, FTAG, &ds);
    732 	if (error == 0) {
    733 		objset_t *os;
    734 		if (dmu_objset_from_ds(ds, &os) == 0)
    735 			zil_destroy(dmu_objset_zil(os), B_FALSE);
    736 		error = dsl_dataset_destroy(ds, FTAG, defer);
    737 		/* dsl_dataset_destroy() closes the ds. */
    738 	}
    739 
    740 	return (error);
    741 }
    742 
    743 struct snaparg {
    744 	dsl_sync_task_group_t *dstg;
    745 	char *snapname;
    746 	char failed[MAXPATHLEN];
    747 	boolean_t checkperms;
    748 	nvlist_t *props;
    749 };
    750 
    751 static int
    752 snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
    753 {
    754 	objset_t *os = arg1;
    755 	struct snaparg *sn = arg2;
    756 
    757 	/* The props have already been checked by zfs_check_userprops(). */
    758 
    759 	return (dsl_dataset_snapshot_check(os->os_dsl_dataset,
    760 	    sn->snapname, tx));
    761 }
    762 
    763 static void
    764 snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
    765 {
    766 	objset_t *os = arg1;
    767 	dsl_dataset_t *ds = os->os_dsl_dataset;
    768 	struct snaparg *sn = arg2;
    769 
    770 	dsl_dataset_snapshot_sync(ds, sn->snapname, cr, tx);
    771 
    772 	if (sn->props)
    773 		dsl_props_set_sync(ds->ds_prev, sn->props, cr, tx);
    774 }
    775 
    776 static int
    777 dmu_objset_snapshot_one(char *name, void *arg)
    778 {
    779 	struct snaparg *sn = arg;
    780 	objset_t *os;
    781 	int err;
    782 
    783 	(void) strcpy(sn->failed, name);
    784 
    785 	/*
    786 	 * Check permissions only when requested.  This only applies when
    787 	 * doing a recursive snapshot.  The permission checks for the starting
    788 	 * dataset have already been performed in zfs_secpolicy_snapshot()
    789 	 */
    790 	if (sn->checkperms == B_TRUE &&
    791 	    (err = zfs_secpolicy_snapshot_perms(name, CRED())))
    792 		return (err);
    793 
    794 	err = dmu_objset_hold(name, sn, &os);
    795 	if (err != 0)
    796 		return (err);
    797 
    798 	/* If the objset is in an inconsistent state, return busy */
    799 	if (os->os_dsl_dataset->ds_phys->ds_flags & DS_FLAG_INCONSISTENT) {
    800 		dmu_objset_rele(os, sn);
    801 		return (EBUSY);
    802 	}
    803 
    804 	/*
    805 	 * NB: we need to wait for all in-flight changes to get to disk,
    806 	 * so that we snapshot those changes.  zil_suspend does this as
    807 	 * a side effect.
    808 	 */
    809 	err = zil_suspend(dmu_objset_zil(os));
    810 	if (err == 0) {
    811 		dsl_sync_task_create(sn->dstg, snapshot_check,
    812 		    snapshot_sync, os, sn, 3);
    813 	} else {
    814 		dmu_objset_rele(os, sn);
    815 	}
    816 
    817 	return (err);
    818 }
    819 
    820 int
    821 dmu_objset_snapshot(char *fsname, char *snapname,
    822     nvlist_t *props, boolean_t recursive)
    823 {
    824 	dsl_sync_task_t *dst;
    825 	struct snaparg sn;
    826 	spa_t *spa;
    827 	int err;
    828 
    829 	(void) strcpy(sn.failed, fsname);
    830 
    831 	err = spa_open(fsname, &spa, FTAG);
    832 	if (err)
    833 		return (err);
    834 
    835 	sn.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
    836 	sn.snapname = snapname;
    837 	sn.props = props;
    838 
    839 	if (recursive) {
    840 		sn.checkperms = B_TRUE;
    841 		err = dmu_objset_find(fsname,
    842 		    dmu_objset_snapshot_one, &sn, DS_FIND_CHILDREN);
    843 	} else {
    844 		sn.checkperms = B_FALSE;
    845 		err = dmu_objset_snapshot_one(fsname, &sn);
    846 	}
    847 
    848 	if (err == 0)
    849 		err = dsl_sync_task_group_wait(sn.dstg);
    850 
    851 	for (dst = list_head(&sn.dstg->dstg_tasks); dst;
    852 	    dst = list_next(&sn.dstg->dstg_tasks, dst)) {
    853 		objset_t *os = dst->dst_arg1;
    854 		dsl_dataset_t *ds = os->os_dsl_dataset;
    855 		if (dst->dst_err)
    856 			dsl_dataset_name(ds, sn.failed);
    857 		zil_resume(dmu_objset_zil(os));
    858 		dmu_objset_rele(os, &sn);
    859 	}
    860 
    861 	if (err)
    862 		(void) strcpy(fsname, sn.failed);
    863 	dsl_sync_task_group_destroy(sn.dstg);
    864 	spa_close(spa, FTAG);
    865 	return (err);
    866 }
    867 
    868 static void
    869 dmu_objset_sync_dnodes(list_t *list, list_t *newlist, dmu_tx_t *tx)
    870 {
    871 	dnode_t *dn;
    872 
    873 	while (dn = list_head(list)) {
    874 		ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
    875 		ASSERT(dn->dn_dbuf->db_data_pending);
    876 		/*
    877 		 * Initialize dn_zio outside dnode_sync() because the
    878 		 * meta-dnode needs to set it ouside dnode_sync().
    879 		 */
    880 		dn->dn_zio = dn->dn_dbuf->db_data_pending->dr_zio;
    881 		ASSERT(dn->dn_zio);
    882 
    883 		ASSERT3U(dn->dn_nlevels, <=, DN_MAX_LEVELS);
    884 		list_remove(list, dn);
    885 
    886 		if (newlist) {
    887 			(void) dnode_add_ref(dn, newlist);
    888 			list_insert_tail(newlist, dn);
    889 		}
    890 
    891 		dnode_sync(dn, tx);
    892 	}
    893 }
    894 
    895 /* ARGSUSED */
    896 static void
    897 dmu_objset_write_ready(zio_t *zio, arc_buf_t *abuf, void *arg)
    898 {
    899 	blkptr_t *bp = zio->io_bp;
    900 	objset_t *os = arg;
    901 	dnode_phys_t *dnp = &os->os_phys->os_meta_dnode;
    902 
    903 	ASSERT(bp == os->os_rootbp);
    904 	ASSERT(BP_GET_TYPE(bp) == DMU_OT_OBJSET);
    905 	ASSERT(BP_GET_LEVEL(bp) == 0);
    906 
    907 	/*
    908 	 * Update rootbp fill count: it should be the number of objects
    909 	 * allocated in the object set (not counting the "special"
    910 	 * objects that are stored in the objset_phys_t -- the meta
    911 	 * dnode and user/group accounting objects).
    912 	 */
    913 	bp->blk_fill = 0;
    914 	for (int i = 0; i < dnp->dn_nblkptr; i++)
    915 		bp->blk_fill += dnp->dn_blkptr[i].blk_fill;
    916 }
    917 
    918 /* ARGSUSED */
    919 static void
    920 dmu_objset_write_done(zio_t *zio, arc_buf_t *abuf, void *arg)
    921 {
    922 	blkptr_t *bp = zio->io_bp;
    923 	blkptr_t *bp_orig = &zio->io_bp_orig;
    924 	objset_t *os = arg;
    925 
    926 	if (zio->io_flags & ZIO_FLAG_IO_REWRITE) {
    927 		ASSERT(BP_EQUAL(bp, bp_orig));
    928 	} else {
    929 		dsl_dataset_t *ds = os->os_dsl_dataset;
    930 		dmu_tx_t *tx = os->os_synctx;
    931 
    932 		(void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE);
    933 		dsl_dataset_block_born(ds, bp, tx);
    934 	}
    935 }
    936 
    937 /* called from dsl */
    938 void
    939 dmu_objset_sync(objset_t *os, zio_t *pio, dmu_tx_t *tx)
    940 {
    941 	int txgoff;
    942 	zbookmark_t zb;
    943 	zio_prop_t zp;
    944 	zio_t *zio;
    945 	list_t *list;
    946 	list_t *newlist = NULL;
    947 	dbuf_dirty_record_t *dr;
    948 
    949 	dprintf_ds(os->os_dsl_dataset, "txg=%llu\n", tx->tx_txg);
    950 
    951 	ASSERT(dmu_tx_is_syncing(tx));
    952 	/* XXX the write_done callback should really give us the tx... */
    953 	os->os_synctx = tx;
    954 
    955 	if (os->os_dsl_dataset == NULL) {
    956 		/*
    957 		 * This is the MOS.  If we have upgraded,
    958 		 * spa_max_replication() could change, so reset
    959 		 * os_copies here.
    960 		 */
    961 		os->os_copies = spa_max_replication(os->os_spa);
    962 	}
    963 
    964 	/*
    965 	 * Create the root block IO
    966 	 */
    967 	arc_release(os->os_phys_buf, &os->os_phys_buf);
    968 
    969 	SET_BOOKMARK(&zb, os->os_dsl_dataset ?
    970 	    os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
    971 	    ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
    972 
    973 	dmu_write_policy(os, NULL, 0, 0, &zp);
    974 
    975 	zio = arc_write(pio, os->os_spa, tx->tx_txg,
    976 	    os->os_rootbp, os->os_phys_buf, DMU_OS_IS_L2CACHEABLE(os), &zp,
    977 	    dmu_objset_write_ready, dmu_objset_write_done, os,
    978 	    ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
    979 
    980 	/*
    981 	 * Sync special dnodes - the parent IO for the sync is the root block
    982 	 */
    983 	os->os_meta_dnode->dn_zio = zio;
    984 	dnode_sync(os->os_meta_dnode, tx);
    985 
    986 	os->os_phys->os_flags = os->os_flags;
    987 
    988 	if (os->os_userused_dnode &&
    989 	    os->os_userused_dnode->dn_type != DMU_OT_NONE) {
    990 		os->os_userused_dnode->dn_zio = zio;
    991 		dnode_sync(os->os_userused_dnode, tx);
    992 		os->os_groupused_dnode->dn_zio = zio;
    993 		dnode_sync(os->os_groupused_dnode, tx);
    994 	}
    995 
    996 	txgoff = tx->tx_txg & TXG_MASK;
    997 
    998 	if (dmu_objset_userused_enabled(os)) {
    999 		newlist = &os->os_synced_dnodes;
   1000 		/*
   1001 		 * We must create the list here because it uses the
   1002 		 * dn_dirty_link[] of this txg.
   1003 		 */
   1004 		list_create(newlist, sizeof (dnode_t),
   1005 		    offsetof(dnode_t, dn_dirty_link[txgoff]));
   1006 	}
   1007 
   1008 	dmu_objset_sync_dnodes(&os->os_free_dnodes[txgoff], newlist, tx);
   1009 	dmu_objset_sync_dnodes(&os->os_dirty_dnodes[txgoff], newlist, tx);
   1010 
   1011 	list = &os->os_meta_dnode->dn_dirty_records[txgoff];
   1012 	while (dr = list_head(list)) {
   1013 		ASSERT(dr->dr_dbuf->db_level == 0);
   1014 		list_remove(list, dr);
   1015 		if (dr->dr_zio)
   1016 			zio_nowait(dr->dr_zio);
   1017 	}
   1018 	/*
   1019 	 * Free intent log blocks up to this tx.
   1020 	 */
   1021 	zil_sync(os->os_zil, tx);
   1022 	os->os_phys->os_zil_header = os->os_zil_header;
   1023 	zio_nowait(zio);
   1024 }
   1025 
   1026 boolean_t
   1027 dmu_objset_is_dirty(objset_t *os, uint64_t txg)
   1028 {
   1029 	return (!list_is_empty(&os->os_dirty_dnodes[txg & TXG_MASK]) ||
   1030 	    !list_is_empty(&os->os_free_dnodes[txg & TXG_MASK]));
   1031 }
   1032 
   1033 static objset_used_cb_t *used_cbs[DMU_OST_NUMTYPES];
   1034 
   1035 void
   1036 dmu_objset_register_type(dmu_objset_type_t ost, objset_used_cb_t *cb)
   1037 {
   1038 	used_cbs[ost] = cb;
   1039 }
   1040 
   1041 boolean_t
   1042 dmu_objset_userused_enabled(objset_t *os)
   1043 {
   1044 	return (spa_version(os->os_spa) >= SPA_VERSION_USERSPACE &&
   1045 	    used_cbs[os->os_phys->os_type] &&
   1046 	    os->os_userused_dnode);
   1047 }
   1048 
   1049 static void
   1050 do_userquota_callback(objset_t *os, dnode_phys_t *dnp,
   1051     boolean_t subtract, dmu_tx_t *tx)
   1052 {
   1053 	static const char zerobuf[DN_MAX_BONUSLEN] = {0};
   1054 	uint64_t user, group;
   1055 
   1056 	ASSERT(dnp->dn_type != 0 ||
   1057 	    (bcmp(DN_BONUS(dnp), zerobuf, DN_MAX_BONUSLEN) == 0 &&
   1058 	    DN_USED_BYTES(dnp) == 0));
   1059 
   1060 	if ((dnp->dn_flags & DNODE_FLAG_USERUSED_ACCOUNTED) &&
   1061 	    0 == used_cbs[os->os_phys->os_type](dnp->dn_bonustype,
   1062 	    DN_BONUS(dnp), &user, &group)) {
   1063 		int64_t delta = DNODE_SIZE + DN_USED_BYTES(dnp);
   1064 		if (subtract)
   1065 			delta = -delta;
   1066 		VERIFY3U(0, ==, zap_increment_int(os, DMU_USERUSED_OBJECT,
   1067 		    user, delta, tx));
   1068 		VERIFY3U(0, ==, zap_increment_int(os, DMU_GROUPUSED_OBJECT,
   1069 		    group, delta, tx));
   1070 	}
   1071 }
   1072 
   1073 void
   1074 dmu_objset_do_userquota_callbacks(objset_t *os, dmu_tx_t *tx)
   1075 {
   1076 	dnode_t *dn;
   1077 	list_t *list = &os->os_synced_dnodes;
   1078 
   1079 	ASSERT(list_head(list) == NULL || dmu_objset_userused_enabled(os));
   1080 
   1081 	while (dn = list_head(list)) {
   1082 		ASSERT(!DMU_OBJECT_IS_SPECIAL(dn->dn_object));
   1083 		ASSERT(dn->dn_oldphys);
   1084 		ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE ||
   1085 		    dn->dn_phys->dn_flags &
   1086 		    DNODE_FLAG_USERUSED_ACCOUNTED);
   1087 
   1088 		/* Allocate the user/groupused objects if necessary. */
   1089 		if (os->os_userused_dnode->dn_type == DMU_OT_NONE) {
   1090 			VERIFY(0 == zap_create_claim(os,
   1091 			    DMU_USERUSED_OBJECT,
   1092 			    DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx));
   1093 			VERIFY(0 == zap_create_claim(os,
   1094 			    DMU_GROUPUSED_OBJECT,
   1095 			    DMU_OT_USERGROUP_USED, DMU_OT_NONE, 0, tx));
   1096 		}
   1097 
   1098 		/*
   1099 		 * We intentionally modify the zap object even if the
   1100 		 * net delta (due to phys-oldphys) is zero.  Otherwise
   1101 		 * the block of the zap obj could be shared between
   1102 		 * datasets but need to be different between them after
   1103 		 * a bprewrite.
   1104 		 */
   1105 		do_userquota_callback(os, dn->dn_oldphys, B_TRUE, tx);
   1106 		do_userquota_callback(os, dn->dn_phys, B_FALSE, tx);
   1107 
   1108 		/*
   1109 		 * The mutex is needed here for interlock with dnode_allocate.
   1110 		 */
   1111 		mutex_enter(&dn->dn_mtx);
   1112 		zio_buf_free(dn->dn_oldphys, sizeof (dnode_phys_t));
   1113 		dn->dn_oldphys = NULL;
   1114 		mutex_exit(&dn->dn_mtx);
   1115 
   1116 		list_remove(list, dn);
   1117 		dnode_rele(dn, list);
   1118 	}
   1119 }
   1120 
   1121 boolean_t
   1122 dmu_objset_userspace_present(objset_t *os)
   1123 {
   1124 	return (os->os_phys->os_flags &
   1125 	    OBJSET_FLAG_USERACCOUNTING_COMPLETE);
   1126 }
   1127 
   1128 int
   1129 dmu_objset_userspace_upgrade(objset_t *os)
   1130 {
   1131 	uint64_t obj;
   1132 	int err = 0;
   1133 
   1134 	if (dmu_objset_userspace_present(os))
   1135 		return (0);
   1136 	if (!dmu_objset_userused_enabled(os))
   1137 		return (ENOTSUP);
   1138 	if (dmu_objset_is_snapshot(os))
   1139 		return (EINVAL);
   1140 
   1141 	/*
   1142 	 * We simply need to mark every object dirty, so that it will be
   1143 	 * synced out and now accounted.  If this is called
   1144 	 * concurrently, or if we already did some work before crashing,
   1145 	 * that's fine, since we track each object's accounted state
   1146 	 * independently.
   1147 	 */
   1148 
   1149 	for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 0)) {
   1150 		dmu_tx_t *tx;
   1151 		dmu_buf_t *db;
   1152 		int objerr;
   1153 
   1154 		if (issig(JUSTLOOKING) && issig(FORREAL))
   1155 			return (EINTR);
   1156 
   1157 		objerr = dmu_bonus_hold(os, obj, FTAG, &db);
   1158 		if (objerr)
   1159 			continue;
   1160 		tx = dmu_tx_create(os);
   1161 		dmu_tx_hold_bonus(tx, obj);
   1162 		objerr = dmu_tx_assign(tx, TXG_WAIT);
   1163 		if (objerr) {
   1164 			dmu_tx_abort(tx);
   1165 			continue;
   1166 		}
   1167 		dmu_buf_will_dirty(db, tx);
   1168 		dmu_buf_rele(db, FTAG);
   1169 		dmu_tx_commit(tx);
   1170 	}
   1171 
   1172 	os->os_flags |= OBJSET_FLAG_USERACCOUNTING_COMPLETE;
   1173 	txg_wait_synced(dmu_objset_pool(os), 0);
   1174 	return (0);
   1175 }
   1176 
   1177 void
   1178 dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
   1179     uint64_t *usedobjsp, uint64_t *availobjsp)
   1180 {
   1181 	dsl_dataset_space(os->os_dsl_dataset, refdbytesp, availbytesp,
   1182 	    usedobjsp, availobjsp);
   1183 }
   1184 
   1185 uint64_t
   1186 dmu_objset_fsid_guid(objset_t *os)
   1187 {
   1188 	return (dsl_dataset_fsid_guid(os->os_dsl_dataset));
   1189 }
   1190 
   1191 void
   1192 dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat)
   1193 {
   1194 	stat->dds_type = os->os_phys->os_type;
   1195 	if (os->os_dsl_dataset)
   1196 		dsl_dataset_fast_stat(os->os_dsl_dataset, stat);
   1197 }
   1198 
   1199 void
   1200 dmu_objset_stats(objset_t *os, nvlist_t *nv)
   1201 {
   1202 	ASSERT(os->os_dsl_dataset ||
   1203 	    os->os_phys->os_type == DMU_OST_META);
   1204 
   1205 	if (os->os_dsl_dataset != NULL)
   1206 		dsl_dataset_stats(os->os_dsl_dataset, nv);
   1207 
   1208 	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_TYPE,
   1209 	    os->os_phys->os_type);
   1210 	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERACCOUNTING,
   1211 	    dmu_objset_userspace_present(os));
   1212 }
   1213 
   1214 int
   1215 dmu_objset_is_snapshot(objset_t *os)
   1216 {
   1217 	if (os->os_dsl_dataset != NULL)
   1218 		return (dsl_dataset_is_snapshot(os->os_dsl_dataset));
   1219 	else
   1220 		return (B_FALSE);
   1221 }
   1222 
   1223 int
   1224 dmu_snapshot_realname(objset_t *os, char *name, char *real, int maxlen,
   1225     boolean_t *conflict)
   1226 {
   1227 	dsl_dataset_t *ds = os->os_dsl_dataset;
   1228 	uint64_t ignored;
   1229 
   1230 	if (ds->ds_phys->ds_snapnames_zapobj == 0)
   1231 		return (ENOENT);
   1232 
   1233 	return (zap_lookup_norm(ds->ds_dir->dd_pool->dp_meta_objset,
   1234 	    ds->ds_phys->ds_snapnames_zapobj, name, 8, 1, &ignored, MT_FIRST,
   1235 	    real, maxlen, conflict));
   1236 }
   1237 
   1238 int
   1239 dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
   1240     uint64_t *idp, uint64_t *offp, boolean_t *case_conflict)
   1241 {
   1242 	dsl_dataset_t *ds = os->os_dsl_dataset;
   1243 	zap_cursor_t cursor;
   1244 	zap_attribute_t attr;
   1245 
   1246 	if (ds->ds_phys->ds_snapnames_zapobj == 0)
   1247 		return (ENOENT);
   1248 
   1249 	zap_cursor_init_serialized(&cursor,
   1250 	    ds->ds_dir->dd_pool->dp_meta_objset,
   1251 	    ds->ds_phys->ds_snapnames_zapobj, *offp);
   1252 
   1253 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
   1254 		zap_cursor_fini(&cursor);
   1255 		return (ENOENT);
   1256 	}
   1257 
   1258 	if (strlen(attr.za_name) + 1 > namelen) {
   1259 		zap_cursor_fini(&cursor);
   1260 		return (ENAMETOOLONG);
   1261 	}
   1262 
   1263 	(void) strcpy(name, attr.za_name);
   1264 	if (idp)
   1265 		*idp = attr.za_first_integer;
   1266 	if (case_conflict)
   1267 		*case_conflict = attr.za_normalization_conflict;
   1268 	zap_cursor_advance(&cursor);
   1269 	*offp = zap_cursor_serialize(&cursor);
   1270 	zap_cursor_fini(&cursor);
   1271 
   1272 	return (0);
   1273 }
   1274 
   1275 int
   1276 dmu_dir_list_next(objset_t *os, int namelen, char *name,
   1277     uint64_t *idp, uint64_t *offp)
   1278 {
   1279 	dsl_dir_t *dd = os->os_dsl_dataset->ds_dir;
   1280 	zap_cursor_t cursor;
   1281 	zap_attribute_t attr;
   1282 
   1283 	/* there is no next dir on a snapshot! */
   1284 	if (os->os_dsl_dataset->ds_object !=
   1285 	    dd->dd_phys->dd_head_dataset_obj)
   1286 		return (ENOENT);
   1287 
   1288 	zap_cursor_init_serialized(&cursor,
   1289 	    dd->dd_pool->dp_meta_objset,
   1290 	    dd->dd_phys->dd_child_dir_zapobj, *offp);
   1291 
   1292 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
   1293 		zap_cursor_fini(&cursor);
   1294 		return (ENOENT);
   1295 	}
   1296 
   1297 	if (strlen(attr.za_name) + 1 > namelen) {
   1298 		zap_cursor_fini(&cursor);
   1299 		return (ENAMETOOLONG);
   1300 	}
   1301 
   1302 	(void) strcpy(name, attr.za_name);
   1303 	if (idp)
   1304 		*idp = attr.za_first_integer;
   1305 	zap_cursor_advance(&cursor);
   1306 	*offp = zap_cursor_serialize(&cursor);
   1307 	zap_cursor_fini(&cursor);
   1308 
   1309 	return (0);
   1310 }
   1311 
   1312 struct findarg {
   1313 	int (*func)(char *, void *);
   1314 	void *arg;
   1315 };
   1316 
   1317 /* ARGSUSED */
   1318 static int
   1319 findfunc(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
   1320 {
   1321 	struct findarg *fa = arg;
   1322 	return (fa->func((char *)dsname, fa->arg));
   1323 }
   1324 
   1325 /*
   1326  * Find all objsets under name, and for each, call 'func(child_name, arg)'.
   1327  * Perhaps change all callers to use dmu_objset_find_spa()?
   1328  */
   1329 int
   1330 dmu_objset_find(char *name, int func(char *, void *), void *arg, int flags)
   1331 {
   1332 	struct findarg fa;
   1333 	fa.func = func;
   1334 	fa.arg = arg;
   1335 	return (dmu_objset_find_spa(NULL, name, findfunc, &fa, flags));
   1336 }
   1337 
   1338 /*
   1339  * Find all objsets under name, call func on each
   1340  */
   1341 int
   1342 dmu_objset_find_spa(spa_t *spa, const char *name,
   1343     int func(spa_t *, uint64_t, const char *, void *), void *arg, int flags)
   1344 {
   1345 	dsl_dir_t *dd;
   1346 	dsl_pool_t *dp;
   1347 	dsl_dataset_t *ds;
   1348 	zap_cursor_t zc;
   1349 	zap_attribute_t *attr;
   1350 	char *child;
   1351 	uint64_t thisobj;
   1352 	int err;
   1353 
   1354 	if (name == NULL)
   1355 		name = spa_name(spa);
   1356 	err = dsl_dir_open_spa(spa, name, FTAG, &dd, NULL);
   1357 	if (err)
   1358 		return (err);
   1359 
   1360 	/* Don't visit hidden ($MOS & $ORIGIN) objsets. */
   1361 	if (dd->dd_myname[0] == '$') {
   1362 		dsl_dir_close(dd, FTAG);
   1363 		return (0);
   1364 	}
   1365 
   1366 	thisobj = dd->dd_phys->dd_head_dataset_obj;
   1367 	attr = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
   1368 	dp = dd->dd_pool;
   1369 
   1370 	/*
   1371 	 * Iterate over all children.
   1372 	 */
   1373 	if (flags & DS_FIND_CHILDREN) {
   1374 		for (zap_cursor_init(&zc, dp->dp_meta_objset,
   1375 		    dd->dd_phys->dd_child_dir_zapobj);
   1376 		    zap_cursor_retrieve(&zc, attr) == 0;
   1377 		    (void) zap_cursor_advance(&zc)) {
   1378 			ASSERT(attr->za_integer_length == sizeof (uint64_t));
   1379 			ASSERT(attr->za_num_integers == 1);
   1380 
   1381 			child = kmem_alloc(MAXPATHLEN, KM_SLEEP);
   1382 			(void) strcpy(child, name);
   1383 			(void) strcat(child, "/");
   1384 			(void) strcat(child, attr->za_name);
   1385 			err = dmu_objset_find_spa(spa, child, func, arg, flags);
   1386 			kmem_free(child, MAXPATHLEN);
   1387 			if (err)
   1388 				break;
   1389 		}
   1390 		zap_cursor_fini(&zc);
   1391 
   1392 		if (err) {
   1393 			dsl_dir_close(dd, FTAG);
   1394 			kmem_free(attr, sizeof (zap_attribute_t));
   1395 			return (err);
   1396 		}
   1397 	}
   1398 
   1399 	/*
   1400 	 * Iterate over all snapshots.
   1401 	 */
   1402 	if (flags & DS_FIND_SNAPSHOTS) {
   1403 		if (!dsl_pool_sync_context(dp))
   1404 			rw_enter(&dp->dp_config_rwlock, RW_READER);
   1405 		err = dsl_dataset_hold_obj(dp, thisobj, FTAG, &ds);
   1406 		if (!dsl_pool_sync_context(dp))
   1407 			rw_exit(&dp->dp_config_rwlock);
   1408 
   1409 		if (err == 0) {
   1410 			uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
   1411 			dsl_dataset_rele(ds, FTAG);
   1412 
   1413 			for (zap_cursor_init(&zc, dp->dp_meta_objset, snapobj);
   1414 			    zap_cursor_retrieve(&zc, attr) == 0;
   1415 			    (void) zap_cursor_advance(&zc)) {
   1416 				ASSERT(attr->za_integer_length ==
   1417 				    sizeof (uint64_t));
   1418 				ASSERT(attr->za_num_integers == 1);
   1419 
   1420 				child = kmem_alloc(MAXPATHLEN, KM_SLEEP);
   1421 				(void) strcpy(child, name);
   1422 				(void) strcat(child, "@");
   1423 				(void) strcat(child, attr->za_name);
   1424 				err = func(spa, attr->za_first_integer,
   1425 				    child, arg);
   1426 				kmem_free(child, MAXPATHLEN);
   1427 				if (err)
   1428 					break;
   1429 			}
   1430 			zap_cursor_fini(&zc);
   1431 		}
   1432 	}
   1433 
   1434 	dsl_dir_close(dd, FTAG);
   1435 	kmem_free(attr, sizeof (zap_attribute_t));
   1436 
   1437 	if (err)
   1438 		return (err);
   1439 
   1440 	/*
   1441 	 * Apply to self if appropriate.
   1442 	 */
   1443 	err = func(spa, thisobj, name, arg);
   1444 	return (err);
   1445 }
   1446 
   1447 /* ARGSUSED */
   1448 int
   1449 dmu_objset_prefetch(char *name, void *arg)
   1450 {
   1451 	dsl_dataset_t *ds;
   1452 
   1453 	if (dsl_dataset_hold(name, FTAG, &ds))
   1454 		return (0);
   1455 
   1456 	if (!BP_IS_HOLE(&ds->ds_phys->ds_bp)) {
   1457 		mutex_enter(&ds->ds_opening_lock);
   1458 		if (ds->ds_objset == NULL) {
   1459 			uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
   1460 			zbookmark_t zb;
   1461 
   1462 			SET_BOOKMARK(&zb, ds->ds_object, ZB_ROOT_OBJECT,
   1463 			    ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
   1464 
   1465 			(void) arc_read_nolock(NULL, dsl_dataset_get_spa(ds),
   1466 			    &ds->ds_phys->ds_bp, NULL, NULL,
   1467 			    ZIO_PRIORITY_ASYNC_READ,
   1468 			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
   1469 			    &aflags, &zb);
   1470 		}
   1471 		mutex_exit(&ds->ds_opening_lock);
   1472 	}
   1473 
   1474 	dsl_dataset_rele(ds, FTAG);
   1475 	return (0);
   1476 }
   1477 
   1478 void
   1479 dmu_objset_set_user(objset_t *os, void *user_ptr)
   1480 {
   1481 	ASSERT(MUTEX_HELD(&os->os_user_ptr_lock));
   1482 	os->os_user_ptr = user_ptr;
   1483 }
   1484 
   1485 void *
   1486 dmu_objset_get_user(objset_t *os)
   1487 {
   1488 	ASSERT(MUTEX_HELD(&os->os_user_ptr_lock));
   1489 	return (os->os_user_ptr);
   1490 }
   1491