xref: /titanic_51/usr/src/uts/common/fs/zfs/dmu_objset.c (revision 98f04078d5fc5800e80b21e0b18abe0024af1cbe)
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 == 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 }
172 
173 int
174 dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
175     objset_impl_t **osip)
176 {
177 	objset_impl_t *osi;
178 	int i, err;
179 
180 	ASSERT(ds == NULL || MUTEX_HELD(&ds->ds_opening_lock));
181 
182 	osi = kmem_zalloc(sizeof (objset_impl_t), KM_SLEEP);
183 	osi->os.os = osi;
184 	osi->os_dsl_dataset = ds;
185 	osi->os_spa = spa;
186 	osi->os_rootbp = bp;
187 	if (!BP_IS_HOLE(osi->os_rootbp)) {
188 		uint32_t aflags = ARC_WAIT;
189 		zbookmark_t zb;
190 		zb.zb_objset = ds ? ds->ds_object : 0;
191 		zb.zb_object = 0;
192 		zb.zb_level = -1;
193 		zb.zb_blkid = 0;
194 		if (DMU_OS_IS_L2CACHEABLE(osi))
195 			aflags |= ARC_L2CACHE;
196 
197 		dprintf_bp(osi->os_rootbp, "reading %s", "");
198 		/*
199 		 * NB: when bprewrite scrub can change the bp,
200 		 * and this is called from dmu_objset_open_ds_os, the bp
201 		 * could change, and we'll need a lock.
202 		 */
203 		err = arc_read_nolock(NULL, spa, osi->os_rootbp,
204 		    arc_getbuf_func, &osi->os_phys_buf,
205 		    ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL, &aflags, &zb);
206 		if (err) {
207 			kmem_free(osi, sizeof (objset_impl_t));
208 			/* convert checksum errors into IO errors */
209 			if (err == ECKSUM)
210 				err = EIO;
211 			return (err);
212 		}
213 		osi->os_phys = osi->os_phys_buf->b_data;
214 	} else {
215 		osi->os_phys_buf = arc_buf_alloc(spa, sizeof (objset_phys_t),
216 		    &osi->os_phys_buf, ARC_BUFC_METADATA);
217 		osi->os_phys = osi->os_phys_buf->b_data;
218 		bzero(osi->os_phys, sizeof (objset_phys_t));
219 	}
220 
221 	/*
222 	 * Note: the changed_cb will be called once before the register
223 	 * func returns, thus changing the checksum/compression from the
224 	 * default (fletcher2/off).  Snapshots don't need to know about
225 	 * checksum/compression/copies.
226 	 */
227 	if (ds) {
228 		err = dsl_prop_register(ds, "primarycache",
229 		    primary_cache_changed_cb, osi);
230 		if (err == 0)
231 			err = dsl_prop_register(ds, "secondarycache",
232 			    secondary_cache_changed_cb, osi);
233 		if (!dsl_dataset_is_snapshot(ds)) {
234 			if (err == 0)
235 				err = dsl_prop_register(ds, "checksum",
236 				    checksum_changed_cb, osi);
237 			if (err == 0)
238 				err = dsl_prop_register(ds, "compression",
239 				    compression_changed_cb, osi);
240 			if (err == 0)
241 				err = dsl_prop_register(ds, "copies",
242 				    copies_changed_cb, osi);
243 		}
244 		if (err) {
245 			VERIFY(arc_buf_remove_ref(osi->os_phys_buf,
246 			    &osi->os_phys_buf) == 1);
247 			kmem_free(osi, sizeof (objset_impl_t));
248 			return (err);
249 		}
250 	} else if (ds == NULL) {
251 		/* It's the meta-objset. */
252 		osi->os_checksum = ZIO_CHECKSUM_FLETCHER_4;
253 		osi->os_compress = ZIO_COMPRESS_LZJB;
254 		osi->os_copies = spa_max_replication(spa);
255 		osi->os_primary_cache = ZFS_CACHE_ALL;
256 		osi->os_secondary_cache = ZFS_CACHE_ALL;
257 	}
258 
259 	osi->os_zil_header = osi->os_phys->os_zil_header;
260 	osi->os_zil = zil_alloc(&osi->os, &osi->os_zil_header);
261 
262 	for (i = 0; i < TXG_SIZE; i++) {
263 		list_create(&osi->os_dirty_dnodes[i], sizeof (dnode_t),
264 		    offsetof(dnode_t, dn_dirty_link[i]));
265 		list_create(&osi->os_free_dnodes[i], sizeof (dnode_t),
266 		    offsetof(dnode_t, dn_dirty_link[i]));
267 	}
268 	list_create(&osi->os_dnodes, sizeof (dnode_t),
269 	    offsetof(dnode_t, dn_link));
270 	list_create(&osi->os_downgraded_dbufs, sizeof (dmu_buf_impl_t),
271 	    offsetof(dmu_buf_impl_t, db_link));
272 
273 	mutex_init(&osi->os_lock, NULL, MUTEX_DEFAULT, NULL);
274 	mutex_init(&osi->os_obj_lock, NULL, MUTEX_DEFAULT, NULL);
275 	mutex_init(&osi->os_user_ptr_lock, NULL, MUTEX_DEFAULT, NULL);
276 
277 	osi->os_meta_dnode = dnode_special_open(osi,
278 	    &osi->os_phys->os_meta_dnode, DMU_META_DNODE_OBJECT);
279 
280 	/*
281 	 * We should be the only thread trying to do this because we
282 	 * have ds_opening_lock
283 	 */
284 	if (ds) {
285 		VERIFY(NULL == dsl_dataset_set_user_ptr(ds, osi,
286 		    dmu_objset_evict));
287 	}
288 
289 	*osip = osi;
290 	return (0);
291 }
292 
293 static int
294 dmu_objset_open_ds_os(dsl_dataset_t *ds, objset_t *os, dmu_objset_type_t type)
295 {
296 	objset_impl_t *osi;
297 
298 	mutex_enter(&ds->ds_opening_lock);
299 	osi = dsl_dataset_get_user_ptr(ds);
300 	if (osi == NULL) {
301 		int err;
302 
303 		err = dmu_objset_open_impl(dsl_dataset_get_spa(ds),
304 		    ds, &ds->ds_phys->ds_bp, &osi);
305 		if (err) {
306 			mutex_exit(&ds->ds_opening_lock);
307 			return (err);
308 		}
309 	}
310 	mutex_exit(&ds->ds_opening_lock);
311 
312 	os->os = osi;
313 	os->os_mode = DS_MODE_NOHOLD;
314 
315 	if (type != DMU_OST_ANY && type != os->os->os_phys->os_type)
316 		return (EINVAL);
317 	return (0);
318 }
319 
320 int
321 dmu_objset_open_ds(dsl_dataset_t *ds, dmu_objset_type_t type, objset_t **osp)
322 {
323 	objset_t *os;
324 	int err;
325 
326 	os = kmem_alloc(sizeof (objset_t), KM_SLEEP);
327 	err = dmu_objset_open_ds_os(ds, os, type);
328 	if (err)
329 		kmem_free(os, sizeof (objset_t));
330 	else
331 		*osp = os;
332 	return (err);
333 }
334 
335 /* called from zpl */
336 int
337 dmu_objset_open(const char *name, dmu_objset_type_t type, int mode,
338     objset_t **osp)
339 {
340 	objset_t *os;
341 	dsl_dataset_t *ds;
342 	int err;
343 
344 	ASSERT(DS_MODE_TYPE(mode) == DS_MODE_USER ||
345 	    DS_MODE_TYPE(mode) == DS_MODE_OWNER);
346 
347 	os = kmem_alloc(sizeof (objset_t), KM_SLEEP);
348 	if (DS_MODE_TYPE(mode) == DS_MODE_USER)
349 		err = dsl_dataset_hold(name, os, &ds);
350 	else
351 		err = dsl_dataset_own(name, mode, os, &ds);
352 	if (err) {
353 		kmem_free(os, sizeof (objset_t));
354 		return (err);
355 	}
356 
357 	err = dmu_objset_open_ds_os(ds, os, type);
358 	if (err) {
359 		if (DS_MODE_TYPE(mode) == DS_MODE_USER)
360 			dsl_dataset_rele(ds, os);
361 		else
362 			dsl_dataset_disown(ds, os);
363 		kmem_free(os, sizeof (objset_t));
364 	} else {
365 		os->os_mode = mode;
366 		*osp = os;
367 	}
368 	return (err);
369 }
370 
371 void
372 dmu_objset_close(objset_t *os)
373 {
374 	ASSERT(DS_MODE_TYPE(os->os_mode) == DS_MODE_USER ||
375 	    DS_MODE_TYPE(os->os_mode) == DS_MODE_OWNER ||
376 	    DS_MODE_TYPE(os->os_mode) == DS_MODE_NOHOLD);
377 
378 	if (DS_MODE_TYPE(os->os_mode) == DS_MODE_USER)
379 		dsl_dataset_rele(os->os->os_dsl_dataset, os);
380 	else if (DS_MODE_TYPE(os->os_mode) == DS_MODE_OWNER)
381 		dsl_dataset_disown(os->os->os_dsl_dataset, os);
382 	kmem_free(os, sizeof (objset_t));
383 }
384 
385 int
386 dmu_objset_evict_dbufs(objset_t *os)
387 {
388 	objset_impl_t *osi = os->os;
389 	dnode_t *dn;
390 
391 	mutex_enter(&osi->os_lock);
392 
393 	/* process the mdn last, since the other dnodes have holds on it */
394 	list_remove(&osi->os_dnodes, osi->os_meta_dnode);
395 	list_insert_tail(&osi->os_dnodes, osi->os_meta_dnode);
396 
397 	/*
398 	 * Find the first dnode with holds.  We have to do this dance
399 	 * because dnode_add_ref() only works if you already have a
400 	 * hold.  If there are no holds then it has no dbufs so OK to
401 	 * skip.
402 	 */
403 	for (dn = list_head(&osi->os_dnodes);
404 	    dn && !dnode_add_ref(dn, FTAG);
405 	    dn = list_next(&osi->os_dnodes, dn))
406 		continue;
407 
408 	while (dn) {
409 		dnode_t *next_dn = dn;
410 
411 		do {
412 			next_dn = list_next(&osi->os_dnodes, next_dn);
413 		} while (next_dn && !dnode_add_ref(next_dn, FTAG));
414 
415 		mutex_exit(&osi->os_lock);
416 		dnode_evict_dbufs(dn);
417 		dnode_rele(dn, FTAG);
418 		mutex_enter(&osi->os_lock);
419 		dn = next_dn;
420 	}
421 	mutex_exit(&osi->os_lock);
422 	return (list_head(&osi->os_dnodes) != osi->os_meta_dnode);
423 }
424 
425 void
426 dmu_objset_evict(dsl_dataset_t *ds, void *arg)
427 {
428 	objset_impl_t *osi = arg;
429 	objset_t os;
430 	int i;
431 
432 	for (i = 0; i < TXG_SIZE; i++) {
433 		ASSERT(list_head(&osi->os_dirty_dnodes[i]) == NULL);
434 		ASSERT(list_head(&osi->os_free_dnodes[i]) == NULL);
435 	}
436 
437 	if (ds) {
438 		if (!dsl_dataset_is_snapshot(ds)) {
439 			VERIFY(0 == dsl_prop_unregister(ds, "checksum",
440 			    checksum_changed_cb, osi));
441 			VERIFY(0 == dsl_prop_unregister(ds, "compression",
442 			    compression_changed_cb, osi));
443 			VERIFY(0 == dsl_prop_unregister(ds, "copies",
444 			    copies_changed_cb, osi));
445 		}
446 		VERIFY(0 == dsl_prop_unregister(ds, "primarycache",
447 		    primary_cache_changed_cb, osi));
448 		VERIFY(0 == dsl_prop_unregister(ds, "secondarycache",
449 		    secondary_cache_changed_cb, osi));
450 	}
451 
452 	/*
453 	 * We should need only a single pass over the dnode list, since
454 	 * nothing can be added to the list at this point.
455 	 */
456 	os.os = osi;
457 	(void) dmu_objset_evict_dbufs(&os);
458 
459 	ASSERT3P(list_head(&osi->os_dnodes), ==, osi->os_meta_dnode);
460 	ASSERT3P(list_tail(&osi->os_dnodes), ==, osi->os_meta_dnode);
461 	ASSERT3P(list_head(&osi->os_meta_dnode->dn_dbufs), ==, NULL);
462 
463 	dnode_special_close(osi->os_meta_dnode);
464 	zil_free(osi->os_zil);
465 
466 	VERIFY(arc_buf_remove_ref(osi->os_phys_buf, &osi->os_phys_buf) == 1);
467 	mutex_destroy(&osi->os_lock);
468 	mutex_destroy(&osi->os_obj_lock);
469 	mutex_destroy(&osi->os_user_ptr_lock);
470 	kmem_free(osi, sizeof (objset_impl_t));
471 }
472 
473 /* called from dsl for meta-objset */
474 objset_impl_t *
475 dmu_objset_create_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
476     dmu_objset_type_t type, dmu_tx_t *tx)
477 {
478 	objset_impl_t *osi;
479 	dnode_t *mdn;
480 
481 	ASSERT(dmu_tx_is_syncing(tx));
482 	if (ds)
483 		mutex_enter(&ds->ds_opening_lock);
484 	VERIFY(0 == dmu_objset_open_impl(spa, ds, bp, &osi));
485 	if (ds)
486 		mutex_exit(&ds->ds_opening_lock);
487 	mdn = osi->os_meta_dnode;
488 
489 	dnode_allocate(mdn, DMU_OT_DNODE, 1 << DNODE_BLOCK_SHIFT,
490 	    DN_MAX_INDBLKSHIFT, DMU_OT_NONE, 0, tx);
491 
492 	/*
493 	 * We don't want to have to increase the meta-dnode's nlevels
494 	 * later, because then we could do it in quescing context while
495 	 * we are also accessing it in open context.
496 	 *
497 	 * This precaution is not necessary for the MOS (ds == NULL),
498 	 * because the MOS is only updated in syncing context.
499 	 * This is most fortunate: the MOS is the only objset that
500 	 * needs to be synced multiple times as spa_sync() iterates
501 	 * to convergence, so minimizing its dn_nlevels matters.
502 	 */
503 	if (ds != NULL) {
504 		int levels = 1;
505 
506 		/*
507 		 * Determine the number of levels necessary for the meta-dnode
508 		 * to contain DN_MAX_OBJECT dnodes.
509 		 */
510 		while ((uint64_t)mdn->dn_nblkptr << (mdn->dn_datablkshift +
511 		    (levels - 1) * (mdn->dn_indblkshift - SPA_BLKPTRSHIFT)) <
512 		    DN_MAX_OBJECT * sizeof (dnode_phys_t))
513 			levels++;
514 
515 		mdn->dn_next_nlevels[tx->tx_txg & TXG_MASK] =
516 		    mdn->dn_nlevels = levels;
517 	}
518 
519 	ASSERT(type != DMU_OST_NONE);
520 	ASSERT(type != DMU_OST_ANY);
521 	ASSERT(type < DMU_OST_NUMTYPES);
522 	osi->os_phys->os_type = type;
523 
524 	dsl_dataset_dirty(ds, tx);
525 
526 	return (osi);
527 }
528 
529 struct oscarg {
530 	void (*userfunc)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx);
531 	void *userarg;
532 	dsl_dataset_t *clone_parent;
533 	const char *lastname;
534 	dmu_objset_type_t type;
535 	uint64_t flags;
536 };
537 
538 /*ARGSUSED*/
539 static int
540 dmu_objset_create_check(void *arg1, void *arg2, dmu_tx_t *tx)
541 {
542 	dsl_dir_t *dd = arg1;
543 	struct oscarg *oa = arg2;
544 	objset_t *mos = dd->dd_pool->dp_meta_objset;
545 	int err;
546 	uint64_t ddobj;
547 
548 	err = zap_lookup(mos, dd->dd_phys->dd_child_dir_zapobj,
549 	    oa->lastname, sizeof (uint64_t), 1, &ddobj);
550 	if (err != ENOENT)
551 		return (err ? err : EEXIST);
552 
553 	if (oa->clone_parent != NULL) {
554 		/*
555 		 * You can't clone across pools.
556 		 */
557 		if (oa->clone_parent->ds_dir->dd_pool != dd->dd_pool)
558 			return (EXDEV);
559 
560 		/*
561 		 * You can only clone snapshots, not the head datasets.
562 		 */
563 		if (oa->clone_parent->ds_phys->ds_num_children == 0)
564 			return (EINVAL);
565 	}
566 
567 	return (0);
568 }
569 
570 static void
571 dmu_objset_create_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
572 {
573 	dsl_dir_t *dd = arg1;
574 	struct oscarg *oa = arg2;
575 	dsl_dataset_t *ds;
576 	blkptr_t *bp;
577 	uint64_t dsobj;
578 
579 	ASSERT(dmu_tx_is_syncing(tx));
580 
581 	dsobj = dsl_dataset_create_sync(dd, oa->lastname,
582 	    oa->clone_parent, oa->flags, cr, tx);
583 
584 	VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, dsobj, FTAG, &ds));
585 	bp = dsl_dataset_get_blkptr(ds);
586 	if (BP_IS_HOLE(bp)) {
587 		objset_impl_t *osi;
588 
589 		/* This is an empty dmu_objset; not a clone. */
590 		osi = dmu_objset_create_impl(dsl_dataset_get_spa(ds),
591 		    ds, bp, oa->type, tx);
592 
593 		if (oa->userfunc)
594 			oa->userfunc(&osi->os, oa->userarg, cr, tx);
595 	}
596 
597 	spa_history_internal_log(LOG_DS_CREATE, dd->dd_pool->dp_spa,
598 	    tx, cr, "dataset = %llu", dsobj);
599 
600 	dsl_dataset_rele(ds, FTAG);
601 }
602 
603 int
604 dmu_objset_create(const char *name, dmu_objset_type_t type,
605     objset_t *clone_parent, uint64_t flags,
606     void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg)
607 {
608 	dsl_dir_t *pdd;
609 	const char *tail;
610 	int err = 0;
611 	struct oscarg oa = { 0 };
612 
613 	ASSERT(strchr(name, '@') == NULL);
614 	err = dsl_dir_open(name, FTAG, &pdd, &tail);
615 	if (err)
616 		return (err);
617 	if (tail == NULL) {
618 		dsl_dir_close(pdd, FTAG);
619 		return (EEXIST);
620 	}
621 
622 	dprintf("name=%s\n", name);
623 
624 	oa.userfunc = func;
625 	oa.userarg = arg;
626 	oa.lastname = tail;
627 	oa.type = type;
628 	oa.flags = flags;
629 
630 	if (clone_parent != NULL) {
631 		/*
632 		 * You can't clone to a different type.
633 		 */
634 		if (clone_parent->os->os_phys->os_type != type) {
635 			dsl_dir_close(pdd, FTAG);
636 			return (EINVAL);
637 		}
638 		oa.clone_parent = clone_parent->os->os_dsl_dataset;
639 	}
640 	err = dsl_sync_task_do(pdd->dd_pool, dmu_objset_create_check,
641 	    dmu_objset_create_sync, pdd, &oa, 5);
642 	dsl_dir_close(pdd, FTAG);
643 	return (err);
644 }
645 
646 int
647 dmu_objset_destroy(const char *name)
648 {
649 	objset_t *os;
650 	int error;
651 
652 	/*
653 	 * If it looks like we'll be able to destroy it, and there's
654 	 * an unplayed replay log sitting around, destroy the log.
655 	 * It would be nicer to do this in dsl_dataset_destroy_sync(),
656 	 * but the replay log objset is modified in open context.
657 	 */
658 	error = dmu_objset_open(name, DMU_OST_ANY,
659 	    DS_MODE_OWNER|DS_MODE_READONLY|DS_MODE_INCONSISTENT, &os);
660 	if (error == 0) {
661 		dsl_dataset_t *ds = os->os->os_dsl_dataset;
662 		zil_destroy(dmu_objset_zil(os), B_FALSE);
663 
664 		error = dsl_dataset_destroy(ds, os);
665 		/*
666 		 * dsl_dataset_destroy() closes the ds.
667 		 */
668 		kmem_free(os, sizeof (objset_t));
669 	}
670 
671 	return (error);
672 }
673 
674 /*
675  * This will close the objset.
676  */
677 int
678 dmu_objset_rollback(objset_t *os)
679 {
680 	int err;
681 	dsl_dataset_t *ds;
682 
683 	ds = os->os->os_dsl_dataset;
684 
685 	if (!dsl_dataset_tryown(ds, TRUE, os)) {
686 		dmu_objset_close(os);
687 		return (EBUSY);
688 	}
689 
690 	err = dsl_dataset_rollback(ds, os->os->os_phys->os_type);
691 
692 	/*
693 	 * NB: we close the objset manually because the rollback
694 	 * actually implicitly called dmu_objset_evict(), thus freeing
695 	 * the objset_impl_t.
696 	 */
697 	dsl_dataset_disown(ds, os);
698 	kmem_free(os, sizeof (objset_t));
699 	return (err);
700 }
701 
702 struct snaparg {
703 	dsl_sync_task_group_t *dstg;
704 	char *snapname;
705 	char failed[MAXPATHLEN];
706 	boolean_t checkperms;
707 	nvlist_t *props;
708 };
709 
710 static int
711 snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
712 {
713 	objset_t *os = arg1;
714 	struct snaparg *sn = arg2;
715 
716 	/* The props have already been checked by zfs_check_userprops(). */
717 
718 	return (dsl_dataset_snapshot_check(os->os->os_dsl_dataset,
719 	    sn->snapname, tx));
720 }
721 
722 static void
723 snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
724 {
725 	objset_t *os = arg1;
726 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
727 	struct snaparg *sn = arg2;
728 
729 	dsl_dataset_snapshot_sync(ds, sn->snapname, cr, tx);
730 
731 	if (sn->props)
732 		dsl_props_set_sync(ds->ds_prev, sn->props, cr, tx);
733 }
734 
735 static int
736 dmu_objset_snapshot_one(char *name, void *arg)
737 {
738 	struct snaparg *sn = arg;
739 	objset_t *os;
740 	int err;
741 
742 	(void) strcpy(sn->failed, name);
743 
744 	/*
745 	 * Check permissions only when requested.  This only applies when
746 	 * doing a recursive snapshot.  The permission checks for the starting
747 	 * dataset have already been performed in zfs_secpolicy_snapshot()
748 	 */
749 	if (sn->checkperms == B_TRUE &&
750 	    (err = zfs_secpolicy_snapshot_perms(name, CRED())))
751 		return (err);
752 
753 	err = dmu_objset_open(name, DMU_OST_ANY, DS_MODE_USER, &os);
754 	if (err != 0)
755 		return (err);
756 
757 	/* If the objset is in an inconsistent state, return busy */
758 	if (os->os->os_dsl_dataset->ds_phys->ds_flags & DS_FLAG_INCONSISTENT) {
759 		dmu_objset_close(os);
760 		return (EBUSY);
761 	}
762 
763 	/*
764 	 * NB: we need to wait for all in-flight changes to get to disk,
765 	 * so that we snapshot those changes.  zil_suspend does this as
766 	 * a side effect.
767 	 */
768 	err = zil_suspend(dmu_objset_zil(os));
769 	if (err == 0) {
770 		dsl_sync_task_create(sn->dstg, snapshot_check,
771 		    snapshot_sync, os, sn, 3);
772 	} else {
773 		dmu_objset_close(os);
774 	}
775 
776 	return (err);
777 }
778 
779 int
780 dmu_objset_snapshot(char *fsname, char *snapname,
781     nvlist_t *props, boolean_t recursive)
782 {
783 	dsl_sync_task_t *dst;
784 	struct snaparg sn;
785 	spa_t *spa;
786 	int err;
787 
788 	(void) strcpy(sn.failed, fsname);
789 
790 	err = spa_open(fsname, &spa, FTAG);
791 	if (err)
792 		return (err);
793 
794 	sn.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
795 	sn.snapname = snapname;
796 	sn.props = props;
797 
798 	if (recursive) {
799 		sn.checkperms = B_TRUE;
800 		err = dmu_objset_find(fsname,
801 		    dmu_objset_snapshot_one, &sn, DS_FIND_CHILDREN);
802 	} else {
803 		sn.checkperms = B_FALSE;
804 		err = dmu_objset_snapshot_one(fsname, &sn);
805 	}
806 
807 	if (err == 0)
808 		err = dsl_sync_task_group_wait(sn.dstg);
809 
810 	for (dst = list_head(&sn.dstg->dstg_tasks); dst;
811 	    dst = list_next(&sn.dstg->dstg_tasks, dst)) {
812 		objset_t *os = dst->dst_arg1;
813 		dsl_dataset_t *ds = os->os->os_dsl_dataset;
814 		if (dst->dst_err)
815 			dsl_dataset_name(ds, sn.failed);
816 		zil_resume(dmu_objset_zil(os));
817 		dmu_objset_close(os);
818 	}
819 
820 	if (err)
821 		(void) strcpy(fsname, sn.failed);
822 	dsl_sync_task_group_destroy(sn.dstg);
823 	spa_close(spa, FTAG);
824 	return (err);
825 }
826 
827 static void
828 dmu_objset_sync_dnodes(list_t *list, dmu_tx_t *tx)
829 {
830 	dnode_t *dn;
831 
832 	while (dn = list_head(list)) {
833 		ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
834 		ASSERT(dn->dn_dbuf->db_data_pending);
835 		/*
836 		 * Initialize dn_zio outside dnode_sync()
837 		 * to accomodate meta-dnode
838 		 */
839 		dn->dn_zio = dn->dn_dbuf->db_data_pending->dr_zio;
840 		ASSERT(dn->dn_zio);
841 
842 		ASSERT3U(dn->dn_nlevels, <=, DN_MAX_LEVELS);
843 		list_remove(list, dn);
844 		dnode_sync(dn, tx);
845 	}
846 }
847 
848 /* ARGSUSED */
849 static void
850 ready(zio_t *zio, arc_buf_t *abuf, void *arg)
851 {
852 	blkptr_t *bp = zio->io_bp;
853 	blkptr_t *bp_orig = &zio->io_bp_orig;
854 	objset_impl_t *os = arg;
855 	dnode_phys_t *dnp = &os->os_phys->os_meta_dnode;
856 
857 	ASSERT(bp == os->os_rootbp);
858 	ASSERT(BP_GET_TYPE(bp) == DMU_OT_OBJSET);
859 	ASSERT(BP_GET_LEVEL(bp) == 0);
860 
861 	/*
862 	 * Update rootbp fill count.
863 	 */
864 	bp->blk_fill = 1;	/* count the meta-dnode */
865 	for (int i = 0; i < dnp->dn_nblkptr; i++)
866 		bp->blk_fill += dnp->dn_blkptr[i].blk_fill;
867 
868 	if (zio->io_flags & ZIO_FLAG_IO_REWRITE) {
869 		ASSERT(DVA_EQUAL(BP_IDENTITY(bp), BP_IDENTITY(bp_orig)));
870 	} else {
871 		if (zio->io_bp_orig.blk_birth == os->os_synctx->tx_txg)
872 			(void) dsl_dataset_block_kill(os->os_dsl_dataset,
873 			    &zio->io_bp_orig, zio, os->os_synctx);
874 		dsl_dataset_block_born(os->os_dsl_dataset, bp, os->os_synctx);
875 	}
876 }
877 
878 /* called from dsl */
879 void
880 dmu_objset_sync(objset_impl_t *os, zio_t *pio, dmu_tx_t *tx)
881 {
882 	int txgoff;
883 	zbookmark_t zb;
884 	writeprops_t wp = { 0 };
885 	zio_t *zio;
886 	list_t *list;
887 	dbuf_dirty_record_t *dr;
888 
889 	dprintf_ds(os->os_dsl_dataset, "txg=%llu\n", tx->tx_txg);
890 
891 	ASSERT(dmu_tx_is_syncing(tx));
892 	/* XXX the write_done callback should really give us the tx... */
893 	os->os_synctx = tx;
894 
895 	if (os->os_dsl_dataset == NULL) {
896 		/*
897 		 * This is the MOS.  If we have upgraded,
898 		 * spa_max_replication() could change, so reset
899 		 * os_copies here.
900 		 */
901 		os->os_copies = spa_max_replication(os->os_spa);
902 	}
903 
904 	/*
905 	 * Create the root block IO
906 	 */
907 	zb.zb_objset = os->os_dsl_dataset ? os->os_dsl_dataset->ds_object : 0;
908 	zb.zb_object = 0;
909 	zb.zb_level = -1;	/* for block ordering; it's level 0 on disk */
910 	zb.zb_blkid = 0;
911 
912 	wp.wp_type = DMU_OT_OBJSET;
913 	wp.wp_level = 0;	/* on-disk BP level; see above */
914 	wp.wp_copies = os->os_copies;
915 	wp.wp_oschecksum = os->os_checksum;
916 	wp.wp_oscompress = os->os_compress;
917 
918 	if (BP_IS_OLDER(os->os_rootbp, tx->tx_txg)) {
919 		(void) dsl_dataset_block_kill(os->os_dsl_dataset,
920 		    os->os_rootbp, pio, tx);
921 	}
922 
923 	arc_release(os->os_phys_buf, &os->os_phys_buf);
924 	zio = arc_write(pio, os->os_spa, &wp, DMU_OS_IS_L2CACHEABLE(os),
925 	    tx->tx_txg, os->os_rootbp, os->os_phys_buf, ready, NULL, os,
926 	    ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
927 
928 	/*
929 	 * Sync meta-dnode - the parent IO for the sync is the root block
930 	 */
931 	os->os_meta_dnode->dn_zio = zio;
932 	dnode_sync(os->os_meta_dnode, tx);
933 
934 	txgoff = tx->tx_txg & TXG_MASK;
935 
936 	dmu_objset_sync_dnodes(&os->os_free_dnodes[txgoff], tx);
937 	dmu_objset_sync_dnodes(&os->os_dirty_dnodes[txgoff], tx);
938 
939 	list = &os->os_meta_dnode->dn_dirty_records[txgoff];
940 	while (dr = list_head(list)) {
941 		ASSERT(dr->dr_dbuf->db_level == 0);
942 		list_remove(list, dr);
943 		if (dr->dr_zio)
944 			zio_nowait(dr->dr_zio);
945 	}
946 	/*
947 	 * Free intent log blocks up to this tx.
948 	 */
949 	zil_sync(os->os_zil, tx);
950 	os->os_phys->os_zil_header = os->os_zil_header;
951 	zio_nowait(zio);
952 }
953 
954 void
955 dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
956     uint64_t *usedobjsp, uint64_t *availobjsp)
957 {
958 	dsl_dataset_space(os->os->os_dsl_dataset, refdbytesp, availbytesp,
959 	    usedobjsp, availobjsp);
960 }
961 
962 uint64_t
963 dmu_objset_fsid_guid(objset_t *os)
964 {
965 	return (dsl_dataset_fsid_guid(os->os->os_dsl_dataset));
966 }
967 
968 void
969 dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat)
970 {
971 	stat->dds_type = os->os->os_phys->os_type;
972 	if (os->os->os_dsl_dataset)
973 		dsl_dataset_fast_stat(os->os->os_dsl_dataset, stat);
974 }
975 
976 void
977 dmu_objset_stats(objset_t *os, nvlist_t *nv)
978 {
979 	ASSERT(os->os->os_dsl_dataset ||
980 	    os->os->os_phys->os_type == DMU_OST_META);
981 
982 	if (os->os->os_dsl_dataset != NULL)
983 		dsl_dataset_stats(os->os->os_dsl_dataset, nv);
984 
985 	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_TYPE,
986 	    os->os->os_phys->os_type);
987 }
988 
989 int
990 dmu_objset_is_snapshot(objset_t *os)
991 {
992 	if (os->os->os_dsl_dataset != NULL)
993 		return (dsl_dataset_is_snapshot(os->os->os_dsl_dataset));
994 	else
995 		return (B_FALSE);
996 }
997 
998 int
999 dmu_snapshot_realname(objset_t *os, char *name, char *real, int maxlen,
1000     boolean_t *conflict)
1001 {
1002 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
1003 	uint64_t ignored;
1004 
1005 	if (ds->ds_phys->ds_snapnames_zapobj == 0)
1006 		return (ENOENT);
1007 
1008 	return (zap_lookup_norm(ds->ds_dir->dd_pool->dp_meta_objset,
1009 	    ds->ds_phys->ds_snapnames_zapobj, name, 8, 1, &ignored, MT_FIRST,
1010 	    real, maxlen, conflict));
1011 }
1012 
1013 int
1014 dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
1015     uint64_t *idp, uint64_t *offp, boolean_t *case_conflict)
1016 {
1017 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
1018 	zap_cursor_t cursor;
1019 	zap_attribute_t attr;
1020 
1021 	if (ds->ds_phys->ds_snapnames_zapobj == 0)
1022 		return (ENOENT);
1023 
1024 	zap_cursor_init_serialized(&cursor,
1025 	    ds->ds_dir->dd_pool->dp_meta_objset,
1026 	    ds->ds_phys->ds_snapnames_zapobj, *offp);
1027 
1028 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
1029 		zap_cursor_fini(&cursor);
1030 		return (ENOENT);
1031 	}
1032 
1033 	if (strlen(attr.za_name) + 1 > namelen) {
1034 		zap_cursor_fini(&cursor);
1035 		return (ENAMETOOLONG);
1036 	}
1037 
1038 	(void) strcpy(name, attr.za_name);
1039 	if (idp)
1040 		*idp = attr.za_first_integer;
1041 	if (case_conflict)
1042 		*case_conflict = attr.za_normalization_conflict;
1043 	zap_cursor_advance(&cursor);
1044 	*offp = zap_cursor_serialize(&cursor);
1045 	zap_cursor_fini(&cursor);
1046 
1047 	return (0);
1048 }
1049 
1050 int
1051 dmu_dir_list_next(objset_t *os, int namelen, char *name,
1052     uint64_t *idp, uint64_t *offp)
1053 {
1054 	dsl_dir_t *dd = os->os->os_dsl_dataset->ds_dir;
1055 	zap_cursor_t cursor;
1056 	zap_attribute_t attr;
1057 
1058 	/* there is no next dir on a snapshot! */
1059 	if (os->os->os_dsl_dataset->ds_object !=
1060 	    dd->dd_phys->dd_head_dataset_obj)
1061 		return (ENOENT);
1062 
1063 	zap_cursor_init_serialized(&cursor,
1064 	    dd->dd_pool->dp_meta_objset,
1065 	    dd->dd_phys->dd_child_dir_zapobj, *offp);
1066 
1067 	if (zap_cursor_retrieve(&cursor, &attr) != 0) {
1068 		zap_cursor_fini(&cursor);
1069 		return (ENOENT);
1070 	}
1071 
1072 	if (strlen(attr.za_name) + 1 > namelen) {
1073 		zap_cursor_fini(&cursor);
1074 		return (ENAMETOOLONG);
1075 	}
1076 
1077 	(void) strcpy(name, attr.za_name);
1078 	if (idp)
1079 		*idp = attr.za_first_integer;
1080 	zap_cursor_advance(&cursor);
1081 	*offp = zap_cursor_serialize(&cursor);
1082 	zap_cursor_fini(&cursor);
1083 
1084 	return (0);
1085 }
1086 
1087 struct findarg {
1088 	int (*func)(char *, void *);
1089 	void *arg;
1090 };
1091 
1092 /* ARGSUSED */
1093 static int
1094 findfunc(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
1095 {
1096 	struct findarg *fa = arg;
1097 	return (fa->func((char *)dsname, fa->arg));
1098 }
1099 
1100 /*
1101  * Find all objsets under name, and for each, call 'func(child_name, arg)'.
1102  * Perhaps change all callers to use dmu_objset_find_spa()?
1103  */
1104 int
1105 dmu_objset_find(char *name, int func(char *, void *), void *arg, int flags)
1106 {
1107 	struct findarg fa;
1108 	fa.func = func;
1109 	fa.arg = arg;
1110 	return (dmu_objset_find_spa(NULL, name, findfunc, &fa, flags));
1111 }
1112 
1113 /*
1114  * Find all objsets under name, call func on each
1115  */
1116 int
1117 dmu_objset_find_spa(spa_t *spa, const char *name,
1118     int func(spa_t *, uint64_t, const char *, void *), void *arg, int flags)
1119 {
1120 	dsl_dir_t *dd;
1121 	dsl_pool_t *dp;
1122 	dsl_dataset_t *ds;
1123 	zap_cursor_t zc;
1124 	zap_attribute_t *attr;
1125 	char *child;
1126 	uint64_t thisobj;
1127 	int err;
1128 
1129 	if (name == NULL)
1130 		name = spa_name(spa);
1131 	err = dsl_dir_open_spa(spa, name, FTAG, &dd, NULL);
1132 	if (err)
1133 		return (err);
1134 
1135 	/* Don't visit hidden ($MOS & $ORIGIN) objsets. */
1136 	if (dd->dd_myname[0] == '$') {
1137 		dsl_dir_close(dd, FTAG);
1138 		return (0);
1139 	}
1140 
1141 	thisobj = dd->dd_phys->dd_head_dataset_obj;
1142 	attr = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
1143 	dp = dd->dd_pool;
1144 
1145 	/*
1146 	 * Iterate over all children.
1147 	 */
1148 	if (flags & DS_FIND_CHILDREN) {
1149 		for (zap_cursor_init(&zc, dp->dp_meta_objset,
1150 		    dd->dd_phys->dd_child_dir_zapobj);
1151 		    zap_cursor_retrieve(&zc, attr) == 0;
1152 		    (void) zap_cursor_advance(&zc)) {
1153 			ASSERT(attr->za_integer_length == sizeof (uint64_t));
1154 			ASSERT(attr->za_num_integers == 1);
1155 
1156 			child = kmem_alloc(MAXPATHLEN, KM_SLEEP);
1157 			(void) strcpy(child, name);
1158 			(void) strcat(child, "/");
1159 			(void) strcat(child, attr->za_name);
1160 			err = dmu_objset_find_spa(spa, child, func, arg, flags);
1161 			kmem_free(child, MAXPATHLEN);
1162 			if (err)
1163 				break;
1164 		}
1165 		zap_cursor_fini(&zc);
1166 
1167 		if (err) {
1168 			dsl_dir_close(dd, FTAG);
1169 			kmem_free(attr, sizeof (zap_attribute_t));
1170 			return (err);
1171 		}
1172 	}
1173 
1174 	/*
1175 	 * Iterate over all snapshots.
1176 	 */
1177 	if (flags & DS_FIND_SNAPSHOTS) {
1178 		if (!dsl_pool_sync_context(dp))
1179 			rw_enter(&dp->dp_config_rwlock, RW_READER);
1180 		err = dsl_dataset_hold_obj(dp, thisobj, FTAG, &ds);
1181 		if (!dsl_pool_sync_context(dp))
1182 			rw_exit(&dp->dp_config_rwlock);
1183 
1184 		if (err == 0) {
1185 			uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
1186 			dsl_dataset_rele(ds, FTAG);
1187 
1188 			for (zap_cursor_init(&zc, dp->dp_meta_objset, snapobj);
1189 			    zap_cursor_retrieve(&zc, attr) == 0;
1190 			    (void) zap_cursor_advance(&zc)) {
1191 				ASSERT(attr->za_integer_length ==
1192 				    sizeof (uint64_t));
1193 				ASSERT(attr->za_num_integers == 1);
1194 
1195 				child = kmem_alloc(MAXPATHLEN, KM_SLEEP);
1196 				(void) strcpy(child, name);
1197 				(void) strcat(child, "@");
1198 				(void) strcat(child, attr->za_name);
1199 				err = func(spa, attr->za_first_integer,
1200 				    child, arg);
1201 				kmem_free(child, MAXPATHLEN);
1202 				if (err)
1203 					break;
1204 			}
1205 			zap_cursor_fini(&zc);
1206 		}
1207 	}
1208 
1209 	dsl_dir_close(dd, FTAG);
1210 	kmem_free(attr, sizeof (zap_attribute_t));
1211 
1212 	if (err)
1213 		return (err);
1214 
1215 	/*
1216 	 * Apply to self if appropriate.
1217 	 */
1218 	err = func(spa, thisobj, name, arg);
1219 	return (err);
1220 }
1221 
1222 /* ARGSUSED */
1223 int
1224 dmu_objset_prefetch(char *name, void *arg)
1225 {
1226 	dsl_dataset_t *ds;
1227 
1228 	if (dsl_dataset_hold(name, FTAG, &ds))
1229 		return (0);
1230 
1231 	if (!BP_IS_HOLE(&ds->ds_phys->ds_bp)) {
1232 		mutex_enter(&ds->ds_opening_lock);
1233 		if (!dsl_dataset_get_user_ptr(ds)) {
1234 			uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
1235 			zbookmark_t zb;
1236 
1237 			zb.zb_objset = ds->ds_object;
1238 			zb.zb_object = 0;
1239 			zb.zb_level = -1;
1240 			zb.zb_blkid = 0;
1241 
1242 			(void) arc_read_nolock(NULL, dsl_dataset_get_spa(ds),
1243 			    &ds->ds_phys->ds_bp, NULL, NULL,
1244 			    ZIO_PRIORITY_ASYNC_READ,
1245 			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
1246 			    &aflags, &zb);
1247 		}
1248 		mutex_exit(&ds->ds_opening_lock);
1249 	}
1250 
1251 	dsl_dataset_rele(ds, FTAG);
1252 	return (0);
1253 }
1254 
1255 void
1256 dmu_objset_set_user(objset_t *os, void *user_ptr)
1257 {
1258 	ASSERT(MUTEX_HELD(&os->os->os_user_ptr_lock));
1259 	os->os->os_user_ptr = user_ptr;
1260 }
1261 
1262 void *
1263 dmu_objset_get_user(objset_t *os)
1264 {
1265 	ASSERT(MUTEX_HELD(&os->os->os_user_ptr_lock));
1266 	return (os->os->os_user_ptr);
1267 }
1268