xref: /illumos-gate/usr/src/uts/common/fs/zfs/dmu_send.c (revision bc37da3a)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <sys/dmu.h>
29 #include <sys/dmu_impl.h>
30 #include <sys/dmu_tx.h>
31 #include <sys/dbuf.h>
32 #include <sys/dnode.h>
33 #include <sys/zfs_context.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/dmu_traverse.h>
36 #include <sys/dsl_dataset.h>
37 #include <sys/dsl_dir.h>
38 #include <sys/dsl_pool.h>
39 #include <sys/dsl_synctask.h>
40 #include <sys/zfs_ioctl.h>
41 #include <sys/zap.h>
42 #include <sys/zio_checksum.h>
43 
44 static char *dmu_recv_tag = "dmu_recv_tag";
45 
46 struct backuparg {
47 	dmu_replay_record_t *drr;
48 	vnode_t *vp;
49 	offset_t *off;
50 	objset_t *os;
51 	zio_cksum_t zc;
52 	int err;
53 };
54 
55 static int
56 dump_bytes(struct backuparg *ba, void *buf, int len)
57 {
58 	ssize_t resid; /* have to get resid to get detailed errno */
59 	ASSERT3U(len % 8, ==, 0);
60 
61 	fletcher_4_incremental_native(buf, len, &ba->zc);
62 	ba->err = vn_rdwr(UIO_WRITE, ba->vp,
63 	    (caddr_t)buf, len,
64 	    0, UIO_SYSSPACE, FAPPEND, RLIM64_INFINITY, CRED(), &resid);
65 	*ba->off += len;
66 	return (ba->err);
67 }
68 
69 static int
70 dump_free(struct backuparg *ba, uint64_t object, uint64_t offset,
71     uint64_t length)
72 {
73 	/* write a FREE record */
74 	bzero(ba->drr, sizeof (dmu_replay_record_t));
75 	ba->drr->drr_type = DRR_FREE;
76 	ba->drr->drr_u.drr_free.drr_object = object;
77 	ba->drr->drr_u.drr_free.drr_offset = offset;
78 	ba->drr->drr_u.drr_free.drr_length = length;
79 
80 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
81 		return (EINTR);
82 	return (0);
83 }
84 
85 static int
86 dump_data(struct backuparg *ba, dmu_object_type_t type,
87     uint64_t object, uint64_t offset, int blksz, void *data)
88 {
89 	/* write a DATA record */
90 	bzero(ba->drr, sizeof (dmu_replay_record_t));
91 	ba->drr->drr_type = DRR_WRITE;
92 	ba->drr->drr_u.drr_write.drr_object = object;
93 	ba->drr->drr_u.drr_write.drr_type = type;
94 	ba->drr->drr_u.drr_write.drr_offset = offset;
95 	ba->drr->drr_u.drr_write.drr_length = blksz;
96 
97 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
98 		return (EINTR);
99 	if (dump_bytes(ba, data, blksz))
100 		return (EINTR);
101 	return (0);
102 }
103 
104 static int
105 dump_freeobjects(struct backuparg *ba, uint64_t firstobj, uint64_t numobjs)
106 {
107 	/* write a FREEOBJECTS record */
108 	bzero(ba->drr, sizeof (dmu_replay_record_t));
109 	ba->drr->drr_type = DRR_FREEOBJECTS;
110 	ba->drr->drr_u.drr_freeobjects.drr_firstobj = firstobj;
111 	ba->drr->drr_u.drr_freeobjects.drr_numobjs = numobjs;
112 
113 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
114 		return (EINTR);
115 	return (0);
116 }
117 
118 static int
119 dump_dnode(struct backuparg *ba, uint64_t object, dnode_phys_t *dnp)
120 {
121 	if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
122 		return (dump_freeobjects(ba, object, 1));
123 
124 	/* write an OBJECT record */
125 	bzero(ba->drr, sizeof (dmu_replay_record_t));
126 	ba->drr->drr_type = DRR_OBJECT;
127 	ba->drr->drr_u.drr_object.drr_object = object;
128 	ba->drr->drr_u.drr_object.drr_type = dnp->dn_type;
129 	ba->drr->drr_u.drr_object.drr_bonustype = dnp->dn_bonustype;
130 	ba->drr->drr_u.drr_object.drr_blksz =
131 	    dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
132 	ba->drr->drr_u.drr_object.drr_bonuslen = dnp->dn_bonuslen;
133 	ba->drr->drr_u.drr_object.drr_checksum = dnp->dn_checksum;
134 	ba->drr->drr_u.drr_object.drr_compress = dnp->dn_compress;
135 
136 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
137 		return (EINTR);
138 
139 	if (dump_bytes(ba, DN_BONUS(dnp), P2ROUNDUP(dnp->dn_bonuslen, 8)))
140 		return (EINTR);
141 
142 	/* free anything past the end of the file */
143 	if (dump_free(ba, object, (dnp->dn_maxblkid + 1) *
144 	    (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL))
145 		return (EINTR);
146 	if (ba->err)
147 		return (EINTR);
148 	return (0);
149 }
150 
151 #define	BP_SPAN(dnp, level) \
152 	(((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
153 	(level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
154 
155 static int
156 backup_cb(traverse_blk_cache_t *bc, spa_t *spa, void *arg)
157 {
158 	struct backuparg *ba = arg;
159 	uint64_t object = bc->bc_bookmark.zb_object;
160 	int level = bc->bc_bookmark.zb_level;
161 	uint64_t blkid = bc->bc_bookmark.zb_blkid;
162 	blkptr_t *bp = bc->bc_blkptr.blk_birth ? &bc->bc_blkptr : NULL;
163 	dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
164 	void *data = bc->bc_data;
165 	int err = 0;
166 
167 	if (issig(JUSTLOOKING) && issig(FORREAL))
168 		return (EINTR);
169 
170 	ASSERT(data || bp == NULL);
171 
172 	if (bp == NULL && object == 0) {
173 		uint64_t span = BP_SPAN(bc->bc_dnode, level);
174 		uint64_t dnobj = (blkid * span) >> DNODE_SHIFT;
175 		err = dump_freeobjects(ba, dnobj, span >> DNODE_SHIFT);
176 	} else if (bp == NULL) {
177 		uint64_t span = BP_SPAN(bc->bc_dnode, level);
178 		err = dump_free(ba, object, blkid * span, span);
179 	} else if (data && level == 0 && type == DMU_OT_DNODE) {
180 		dnode_phys_t *blk = data;
181 		int i;
182 		int blksz = BP_GET_LSIZE(bp);
183 
184 		for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
185 			uint64_t dnobj =
186 			    (blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
187 			err = dump_dnode(ba, dnobj, blk+i);
188 			if (err)
189 				break;
190 		}
191 	} else if (level == 0 &&
192 	    type != DMU_OT_DNODE && type != DMU_OT_OBJSET) {
193 		int blksz = BP_GET_LSIZE(bp);
194 		if (data == NULL) {
195 			uint32_t aflags = ARC_WAIT;
196 			arc_buf_t *abuf;
197 			zbookmark_t zb;
198 
199 			zb.zb_objset = ba->os->os->os_dsl_dataset->ds_object;
200 			zb.zb_object = object;
201 			zb.zb_level = level;
202 			zb.zb_blkid = blkid;
203 			(void) arc_read(NULL, spa, bp,
204 			    dmu_ot[type].ot_byteswap, arc_getbuf_func, &abuf,
205 			    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_MUSTSUCCEED,
206 			    &aflags, &zb);
207 
208 			if (abuf) {
209 				err = dump_data(ba, type, object, blkid * blksz,
210 				    blksz, abuf->b_data);
211 				(void) arc_buf_remove_ref(abuf, &abuf);
212 			}
213 		} else {
214 			err = dump_data(ba, type, object, blkid * blksz,
215 			    blksz, data);
216 		}
217 	}
218 
219 	ASSERT(err == 0 || err == EINTR);
220 	return (err);
221 }
222 
223 int
224 dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
225     vnode_t *vp, offset_t *off)
226 {
227 	dsl_dataset_t *ds = tosnap->os->os_dsl_dataset;
228 	dsl_dataset_t *fromds = fromsnap ? fromsnap->os->os_dsl_dataset : NULL;
229 	dmu_replay_record_t *drr;
230 	struct backuparg ba;
231 	int err;
232 	uint64_t fromtxg = 0;
233 
234 	/* tosnap must be a snapshot */
235 	if (ds->ds_phys->ds_next_snap_obj == 0)
236 		return (EINVAL);
237 
238 	/* fromsnap must be an earlier snapshot from the same fs as tosnap */
239 	if (fromds && (ds->ds_dir != fromds->ds_dir ||
240 	    fromds->ds_phys->ds_creation_txg >= ds->ds_phys->ds_creation_txg))
241 		return (EXDEV);
242 
243 	if (fromorigin) {
244 		if (fromsnap)
245 			return (EINVAL);
246 
247 		if (ds->ds_dir->dd_phys->dd_origin_obj != NULL) {
248 			dsl_pool_t *dp = ds->ds_dir->dd_pool;
249 			rw_enter(&dp->dp_config_rwlock, RW_READER);
250 			err = dsl_dataset_open_obj(dp,
251 			    ds->ds_dir->dd_phys->dd_origin_obj, NULL,
252 			    DS_MODE_NONE, FTAG, &fromds);
253 			rw_exit(&dp->dp_config_rwlock);
254 			if (err)
255 				return (err);
256 		} else {
257 			fromorigin = B_FALSE;
258 		}
259 	}
260 
261 
262 	drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
263 	drr->drr_type = DRR_BEGIN;
264 	drr->drr_u.drr_begin.drr_magic = DMU_BACKUP_MAGIC;
265 	drr->drr_u.drr_begin.drr_version = DMU_BACKUP_STREAM_VERSION;
266 	drr->drr_u.drr_begin.drr_creation_time =
267 	    ds->ds_phys->ds_creation_time;
268 	drr->drr_u.drr_begin.drr_type = tosnap->os->os_phys->os_type;
269 	if (fromorigin)
270 		drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CLONE;
271 	drr->drr_u.drr_begin.drr_toguid = ds->ds_phys->ds_guid;
272 	if (fromds)
273 		drr->drr_u.drr_begin.drr_fromguid = fromds->ds_phys->ds_guid;
274 	dsl_dataset_name(ds, drr->drr_u.drr_begin.drr_toname);
275 
276 	if (fromds)
277 		fromtxg = fromds->ds_phys->ds_creation_txg;
278 	if (fromorigin)
279 		dsl_dataset_close(fromds, DS_MODE_NONE, FTAG);
280 
281 	ba.drr = drr;
282 	ba.vp = vp;
283 	ba.os = tosnap;
284 	ba.off = off;
285 	ZIO_SET_CHECKSUM(&ba.zc, 0, 0, 0, 0);
286 
287 	if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t))) {
288 		kmem_free(drr, sizeof (dmu_replay_record_t));
289 		return (ba.err);
290 	}
291 
292 	err = traverse_dsl_dataset(ds, fromtxg,
293 	    ADVANCE_PRE | ADVANCE_HOLES | ADVANCE_DATA | ADVANCE_NOLOCK,
294 	    backup_cb, &ba);
295 
296 	if (err) {
297 		if (err == EINTR && ba.err)
298 			err = ba.err;
299 		kmem_free(drr, sizeof (dmu_replay_record_t));
300 		return (err);
301 	}
302 
303 	bzero(drr, sizeof (dmu_replay_record_t));
304 	drr->drr_type = DRR_END;
305 	drr->drr_u.drr_end.drr_checksum = ba.zc;
306 
307 	if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t))) {
308 		kmem_free(drr, sizeof (dmu_replay_record_t));
309 		return (ba.err);
310 	}
311 
312 	kmem_free(drr, sizeof (dmu_replay_record_t));
313 
314 	return (0);
315 }
316 
317 struct recvbeginsyncarg {
318 	const char *tofs;
319 	const char *tosnap;
320 	dsl_dataset_t *origin;
321 	uint64_t fromguid;
322 	dmu_objset_type_t type;
323 	void *tag;
324 	boolean_t force;
325 	char clonelastname[MAXNAMELEN];
326 	dsl_dataset_t *ds; /* the ds to recv into; returned from the syncfunc */
327 };
328 
329 static dsl_dataset_t *
330 recv_full_sync_impl(dsl_pool_t *dp, uint64_t dsobj, dmu_objset_type_t type,
331     cred_t *cr, dmu_tx_t *tx)
332 {
333 	dsl_dataset_t *ds;
334 
335 	VERIFY(0 == dsl_dataset_open_obj(dp, dsobj, NULL,
336 	    DS_MODE_EXCLUSIVE, dmu_recv_tag, &ds));
337 
338 	if (type != DMU_OST_NONE) {
339 		(void) dmu_objset_create_impl(dp->dp_spa,
340 		    ds, &ds->ds_phys->ds_bp, type, tx);
341 	}
342 
343 	dmu_buf_will_dirty(ds->ds_dbuf, tx);
344 	ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
345 
346 	spa_history_internal_log(LOG_DS_REPLAY_FULL_SYNC,
347 	    ds->ds_dir->dd_pool->dp_spa, tx, cr, "dataset = %lld",
348 	    ds->ds_phys->ds_dir_obj);
349 
350 	return (ds);
351 }
352 
353 /* ARGSUSED */
354 static int
355 recv_full_check(void *arg1, void *arg2, dmu_tx_t *tx)
356 {
357 	dsl_dir_t *dd = arg1;
358 	struct recvbeginsyncarg *rbsa = arg2;
359 	objset_t *mos = dd->dd_pool->dp_meta_objset;
360 	uint64_t val;
361 	int err;
362 
363 	err = zap_lookup(mos, dd->dd_phys->dd_child_dir_zapobj,
364 	    strrchr(rbsa->tofs, '/') + 1, sizeof (uint64_t), 1, &val);
365 
366 	if (err != ENOENT)
367 		return (err ? err : EEXIST);
368 
369 	if (rbsa->origin) {
370 		/* make sure it's a snap in the same pool */
371 		if (rbsa->origin->ds_dir->dd_pool != dd->dd_pool)
372 			return (EXDEV);
373 		if (rbsa->origin->ds_phys->ds_num_children == 0)
374 			return (EINVAL);
375 		if (rbsa->origin->ds_phys->ds_guid != rbsa->fromguid)
376 			return (ENODEV);
377 	}
378 
379 	return (0);
380 }
381 
382 static void
383 recv_full_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
384 {
385 	dsl_dir_t *dd = arg1;
386 	struct recvbeginsyncarg *rbsa = arg2;
387 	uint64_t dsobj;
388 
389 	dsobj = dsl_dataset_create_sync(dd, strrchr(rbsa->tofs, '/') + 1,
390 	    rbsa->origin, cr, tx);
391 
392 	rbsa->ds = recv_full_sync_impl(dd->dd_pool, dsobj,
393 	    rbsa->origin ? DMU_OST_NONE : rbsa->type, cr, tx);
394 }
395 
396 static int
397 recv_full_existing_check(void *arg1, void *arg2, dmu_tx_t *tx)
398 {
399 	dsl_dataset_t *ds = arg1;
400 	struct recvbeginsyncarg *rbsa = arg2;
401 	int err;
402 
403 	/* must be a head ds */
404 	if (ds->ds_phys->ds_next_snap_obj != 0)
405 		return (EINVAL);
406 
407 	/* must not be a clone ds */
408 	if (ds->ds_prev != NULL)
409 		return (EINVAL);
410 
411 	err = dsl_dataset_destroy_check(ds, rbsa->tag, tx);
412 	if (err)
413 		return (err);
414 
415 	if (rbsa->origin) {
416 		/* make sure it's a snap in the same pool */
417 		if (rbsa->origin->ds_dir->dd_pool != ds->ds_dir->dd_pool)
418 			return (EXDEV);
419 		if (rbsa->origin->ds_phys->ds_num_children == 0)
420 			return (EINVAL);
421 		if (rbsa->origin->ds_phys->ds_guid != rbsa->fromguid)
422 			return (ENODEV);
423 	}
424 
425 	return (0);
426 }
427 
428 static void
429 recv_full_existing_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
430 {
431 	dsl_dataset_t *ds = arg1;
432 	struct recvbeginsyncarg *rbsa = arg2;
433 	dsl_dir_t *dd = ds->ds_dir;
434 	uint64_t dsobj;
435 
436 	/*
437 	 * NB: caller must provide an extra hold on the dsl_dir_t, so it
438 	 * won't go away when dsl_dataset_destroy_sync() closes the
439 	 * dataset.
440 	 */
441 	dsl_dataset_destroy_sync(ds, rbsa->tag, cr, tx);
442 
443 	dsobj = dsl_dataset_create_sync_impl(dd, rbsa->origin, tx);
444 
445 	rbsa->ds = recv_full_sync_impl(dd->dd_pool, dsobj,
446 	    rbsa->origin ? DMU_OST_NONE : rbsa->type, cr, tx);
447 }
448 
449 /* ARGSUSED */
450 static int
451 recv_incremental_check(void *arg1, void *arg2, dmu_tx_t *tx)
452 {
453 	dsl_dataset_t *ds = arg1;
454 	struct recvbeginsyncarg *rbsa = arg2;
455 	int err;
456 	uint64_t val;
457 
458 	/* must not have any changes since most recent snapshot */
459 	if (!rbsa->force && dsl_dataset_modified_since_lastsnap(ds))
460 		return (ETXTBSY);
461 
462 	/* must already be a snapshot of this fs */
463 	if (ds->ds_phys->ds_prev_snap_obj == 0)
464 		return (ENODEV);
465 
466 	/* most recent snapshot must match fromguid */
467 	if (ds->ds_prev->ds_phys->ds_guid != rbsa->fromguid)
468 		return (ENODEV);
469 
470 	/* new snapshot name must not exist */
471 	err = zap_lookup(ds->ds_dir->dd_pool->dp_meta_objset,
472 	    ds->ds_phys->ds_snapnames_zapobj, rbsa->tosnap, 8, 1, &val);
473 	if (err == 0)
474 		return (EEXIST);
475 	if (err != ENOENT)
476 		return (err);
477 	return (0);
478 }
479 
480 /* ARGSUSED */
481 static void
482 recv_online_incremental_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
483 {
484 	dsl_dataset_t *ohds = arg1;
485 	struct recvbeginsyncarg *rbsa = arg2;
486 	dsl_pool_t *dp = ohds->ds_dir->dd_pool;
487 	dsl_dataset_t *ods, *cds;
488 	uint64_t dsobj;
489 
490 	/* create the temporary clone */
491 	VERIFY(0 == dsl_dataset_open_obj(dp, ohds->ds_phys->ds_prev_snap_obj,
492 	    NULL, DS_MODE_STANDARD, FTAG, &ods));
493 	dsobj = dsl_dataset_create_sync(ohds->ds_dir,
494 	    rbsa->clonelastname, ods, cr, tx);
495 	dsl_dataset_close(ods, DS_MODE_STANDARD, FTAG);
496 
497 	/* open the temporary clone */
498 	VERIFY(0 == dsl_dataset_open_obj(dp, dsobj, NULL,
499 	    DS_MODE_EXCLUSIVE, dmu_recv_tag, &cds));
500 
501 	/* copy the refquota from the target fs to the clone */
502 	if (ohds->ds_quota > 0)
503 		dsl_dataset_set_quota_sync(cds, &ohds->ds_quota, cr, tx);
504 
505 	dmu_buf_will_dirty(cds->ds_dbuf, tx);
506 	cds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
507 
508 	rbsa->ds = cds;
509 
510 	spa_history_internal_log(LOG_DS_REPLAY_INC_SYNC,
511 	    dp->dp_spa, tx, cr, "dataset = %lld",
512 	    cds->ds_phys->ds_dir_obj);
513 }
514 
515 /* ARGSUSED */
516 static void
517 recv_offline_incremental_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
518 {
519 	dsl_dataset_t *ds = arg1;
520 
521 	dmu_buf_will_dirty(ds->ds_dbuf, tx);
522 	ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
523 
524 	spa_history_internal_log(LOG_DS_REPLAY_INC_SYNC,
525 	    ds->ds_dir->dd_pool->dp_spa, tx, cr, "dataset = %lld",
526 	    ds->ds_phys->ds_dir_obj);
527 }
528 
529 /*
530  * NB: callers *MUST* call dmu_recv_stream() if dmu_recv_begin()
531  * succeeds; otherwise we will leak the holds on the datasets.
532  */
533 int
534 dmu_recv_begin(char *tofs, char *tosnap, struct drr_begin *drrb,
535     boolean_t force, objset_t *origin, boolean_t online, dmu_recv_cookie_t *drc)
536 {
537 	int err = 0;
538 	boolean_t byteswap;
539 	struct recvbeginsyncarg rbsa;
540 	uint64_t version;
541 	int flags;
542 	dsl_dataset_t *ds;
543 
544 	if (drrb->drr_magic == DMU_BACKUP_MAGIC)
545 		byteswap = FALSE;
546 	else if (drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC))
547 		byteswap = TRUE;
548 	else
549 		return (EINVAL);
550 
551 	rbsa.tofs = tofs;
552 	rbsa.tosnap = tosnap;
553 	rbsa.origin = origin ? origin->os->os_dsl_dataset : NULL;
554 	rbsa.fromguid = drrb->drr_fromguid;
555 	rbsa.type = drrb->drr_type;
556 	rbsa.tag = FTAG;
557 	version = drrb->drr_version;
558 	flags = drrb->drr_flags;
559 
560 	if (byteswap) {
561 		rbsa.type = BSWAP_32(rbsa.type);
562 		rbsa.fromguid = BSWAP_64(rbsa.fromguid);
563 		version = BSWAP_64(version);
564 		flags = BSWAP_32(flags);
565 	}
566 
567 	if (version != DMU_BACKUP_STREAM_VERSION ||
568 	    rbsa.type >= DMU_OST_NUMTYPES ||
569 	    ((flags & DRR_FLAG_CLONE) && origin == NULL))
570 		return (EINVAL);
571 
572 	bzero(drc, sizeof (dmu_recv_cookie_t));
573 	drc->drc_drrb = drrb;
574 	drc->drc_tosnap = tosnap;
575 	drc->drc_force = force;
576 
577 	/*
578 	 * Process the begin in syncing context.
579 	 */
580 	if (rbsa.fromguid && !(flags & DRR_FLAG_CLONE) && !online) {
581 		/* offline incremental receive */
582 		err = dsl_dataset_open(tofs,
583 		    DS_MODE_EXCLUSIVE, dmu_recv_tag, &ds);
584 		if (err)
585 			return (err);
586 
587 		/*
588 		 * Only do the rollback if the most recent snapshot
589 		 * matches the incremental source
590 		 */
591 		if (force) {
592 			if (ds->ds_prev == NULL ||
593 			    ds->ds_prev->ds_phys->ds_guid !=
594 			    rbsa.fromguid) {
595 				dsl_dataset_close(ds, DS_MODE_EXCLUSIVE,
596 				    dmu_recv_tag);
597 				return (ENODEV);
598 			}
599 			(void) dsl_dataset_rollback(ds, DMU_OST_NONE);
600 		}
601 		rbsa.force = B_FALSE;
602 		err = dsl_sync_task_do(ds->ds_dir->dd_pool,
603 		    recv_incremental_check,
604 		    recv_offline_incremental_sync,
605 		    ds, &rbsa, 1);
606 		if (err) {
607 			dsl_dataset_close(ds, DS_MODE_EXCLUSIVE, dmu_recv_tag);
608 			return (err);
609 		}
610 		drc->drc_logical_ds = drc->drc_real_ds = ds;
611 	} else if (rbsa.fromguid && !(flags & DRR_FLAG_CLONE)) {
612 		/* online incremental receive */
613 
614 		/* tmp clone name is: tofs/%tosnap" */
615 		(void) snprintf(rbsa.clonelastname, sizeof (rbsa.clonelastname),
616 		    "%%%s", tosnap);
617 
618 		/* open the dataset we are logically receiving into */
619 		err = dsl_dataset_open(tofs,
620 		    DS_MODE_STANDARD, dmu_recv_tag, &ds);
621 		if (err)
622 			return (err);
623 
624 		rbsa.force = force;
625 		err = dsl_sync_task_do(ds->ds_dir->dd_pool,
626 		    recv_incremental_check,
627 		    recv_online_incremental_sync, ds, &rbsa, 5);
628 		if (err) {
629 			dsl_dataset_close(ds, DS_MODE_STANDARD, dmu_recv_tag);
630 			return (err);
631 		}
632 		drc->drc_logical_ds = ds;
633 		drc->drc_real_ds = rbsa.ds;
634 	} else {
635 		/* create new fs -- full backup or clone */
636 		dsl_dir_t *dd = NULL;
637 		const char *tail;
638 
639 		err = dsl_dir_open(tofs, FTAG, &dd, &tail);
640 		if (err)
641 			return (err);
642 		if (tail == NULL) {
643 			if (!force) {
644 				dsl_dir_close(dd, FTAG);
645 				return (EEXIST);
646 			}
647 
648 			rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
649 			err = dsl_dataset_open_obj(dd->dd_pool,
650 			    dd->dd_phys->dd_head_dataset_obj, NULL,
651 			    DS_MODE_EXCLUSIVE | DS_MODE_INCONSISTENT,
652 			    FTAG, &ds);
653 			rw_exit(&dd->dd_pool->dp_config_rwlock);
654 			if (err) {
655 				dsl_dir_close(dd, FTAG);
656 				return (err);
657 			}
658 
659 			err = dsl_sync_task_do(dd->dd_pool,
660 			    recv_full_existing_check,
661 			    recv_full_existing_sync, ds, &rbsa, 5);
662 			/* if successful, sync task closes the ds for us */
663 			if (err)
664 				dsl_dataset_close(ds, DS_MODE_EXCLUSIVE, FTAG);
665 		} else {
666 			err = dsl_sync_task_do(dd->dd_pool, recv_full_check,
667 			    recv_full_sync, dd, &rbsa, 5);
668 			if (err)
669 				return (err);
670 		}
671 		dsl_dir_close(dd, FTAG);
672 		if (err)
673 			return (err);
674 		drc->drc_logical_ds = drc->drc_real_ds = rbsa.ds;
675 		drc->drc_newfs = B_TRUE;
676 	}
677 
678 	/* downgrade our hold on the ds from EXCLUSIVE to PRIMARY */
679 	dsl_dataset_downgrade(drc->drc_real_ds,
680 	    DS_MODE_EXCLUSIVE, DS_MODE_PRIMARY);
681 
682 	return (0);
683 }
684 
685 struct restorearg {
686 	int err;
687 	int byteswap;
688 	vnode_t *vp;
689 	char *buf;
690 	uint64_t voff;
691 	int bufsize; /* amount of memory allocated for buf */
692 	zio_cksum_t cksum;
693 };
694 
695 static void *
696 restore_read(struct restorearg *ra, int len)
697 {
698 	void *rv;
699 	int done = 0;
700 
701 	/* some things will require 8-byte alignment, so everything must */
702 	ASSERT3U(len % 8, ==, 0);
703 
704 	while (done < len) {
705 		ssize_t resid;
706 
707 		ra->err = vn_rdwr(UIO_READ, ra->vp,
708 		    (caddr_t)ra->buf + done, len - done,
709 		    ra->voff, UIO_SYSSPACE, FAPPEND,
710 		    RLIM64_INFINITY, CRED(), &resid);
711 
712 		if (resid == len - done)
713 			ra->err = EINVAL;
714 		ra->voff += len - done - resid;
715 		done = len - resid;
716 		if (ra->err)
717 			return (NULL);
718 	}
719 
720 	ASSERT3U(done, ==, len);
721 	rv = ra->buf;
722 	if (ra->byteswap)
723 		fletcher_4_incremental_byteswap(rv, len, &ra->cksum);
724 	else
725 		fletcher_4_incremental_native(rv, len, &ra->cksum);
726 	return (rv);
727 }
728 
729 static void
730 backup_byteswap(dmu_replay_record_t *drr)
731 {
732 #define	DO64(X) (drr->drr_u.X = BSWAP_64(drr->drr_u.X))
733 #define	DO32(X) (drr->drr_u.X = BSWAP_32(drr->drr_u.X))
734 	drr->drr_type = BSWAP_32(drr->drr_type);
735 	drr->drr_payloadlen = BSWAP_32(drr->drr_payloadlen);
736 	switch (drr->drr_type) {
737 	case DRR_BEGIN:
738 		DO64(drr_begin.drr_magic);
739 		DO64(drr_begin.drr_version);
740 		DO64(drr_begin.drr_creation_time);
741 		DO32(drr_begin.drr_type);
742 		DO32(drr_begin.drr_flags);
743 		DO64(drr_begin.drr_toguid);
744 		DO64(drr_begin.drr_fromguid);
745 		break;
746 	case DRR_OBJECT:
747 		DO64(drr_object.drr_object);
748 		/* DO64(drr_object.drr_allocation_txg); */
749 		DO32(drr_object.drr_type);
750 		DO32(drr_object.drr_bonustype);
751 		DO32(drr_object.drr_blksz);
752 		DO32(drr_object.drr_bonuslen);
753 		break;
754 	case DRR_FREEOBJECTS:
755 		DO64(drr_freeobjects.drr_firstobj);
756 		DO64(drr_freeobjects.drr_numobjs);
757 		break;
758 	case DRR_WRITE:
759 		DO64(drr_write.drr_object);
760 		DO32(drr_write.drr_type);
761 		DO64(drr_write.drr_offset);
762 		DO64(drr_write.drr_length);
763 		break;
764 	case DRR_FREE:
765 		DO64(drr_free.drr_object);
766 		DO64(drr_free.drr_offset);
767 		DO64(drr_free.drr_length);
768 		break;
769 	case DRR_END:
770 		DO64(drr_end.drr_checksum.zc_word[0]);
771 		DO64(drr_end.drr_checksum.zc_word[1]);
772 		DO64(drr_end.drr_checksum.zc_word[2]);
773 		DO64(drr_end.drr_checksum.zc_word[3]);
774 		break;
775 	}
776 #undef DO64
777 #undef DO32
778 }
779 
780 static int
781 restore_object(struct restorearg *ra, objset_t *os, struct drr_object *drro)
782 {
783 	int err;
784 	dmu_tx_t *tx;
785 
786 	err = dmu_object_info(os, drro->drr_object, NULL);
787 
788 	if (err != 0 && err != ENOENT)
789 		return (EINVAL);
790 
791 	if (drro->drr_type == DMU_OT_NONE ||
792 	    drro->drr_type >= DMU_OT_NUMTYPES ||
793 	    drro->drr_bonustype >= DMU_OT_NUMTYPES ||
794 	    drro->drr_checksum >= ZIO_CHECKSUM_FUNCTIONS ||
795 	    drro->drr_compress >= ZIO_COMPRESS_FUNCTIONS ||
796 	    P2PHASE(drro->drr_blksz, SPA_MINBLOCKSIZE) ||
797 	    drro->drr_blksz < SPA_MINBLOCKSIZE ||
798 	    drro->drr_blksz > SPA_MAXBLOCKSIZE ||
799 	    drro->drr_bonuslen > DN_MAX_BONUSLEN) {
800 		return (EINVAL);
801 	}
802 
803 	tx = dmu_tx_create(os);
804 
805 	if (err == ENOENT) {
806 		/* currently free, want to be allocated */
807 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
808 		dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, 1);
809 		err = dmu_tx_assign(tx, TXG_WAIT);
810 		if (err) {
811 			dmu_tx_abort(tx);
812 			return (err);
813 		}
814 		err = dmu_object_claim(os, drro->drr_object,
815 		    drro->drr_type, drro->drr_blksz,
816 		    drro->drr_bonustype, drro->drr_bonuslen, tx);
817 	} else {
818 		/* currently allocated, want to be allocated */
819 		dmu_tx_hold_bonus(tx, drro->drr_object);
820 		/*
821 		 * We may change blocksize, so need to
822 		 * hold_write
823 		 */
824 		dmu_tx_hold_write(tx, drro->drr_object, 0, 1);
825 		err = dmu_tx_assign(tx, TXG_WAIT);
826 		if (err) {
827 			dmu_tx_abort(tx);
828 			return (err);
829 		}
830 
831 		err = dmu_object_reclaim(os, drro->drr_object,
832 		    drro->drr_type, drro->drr_blksz,
833 		    drro->drr_bonustype, drro->drr_bonuslen, tx);
834 	}
835 	if (err) {
836 		dmu_tx_commit(tx);
837 		return (EINVAL);
838 	}
839 
840 	dmu_object_set_checksum(os, drro->drr_object, drro->drr_checksum, tx);
841 	dmu_object_set_compress(os, drro->drr_object, drro->drr_compress, tx);
842 
843 	if (drro->drr_bonuslen) {
844 		dmu_buf_t *db;
845 		void *data;
846 		VERIFY(0 == dmu_bonus_hold(os, drro->drr_object, FTAG, &db));
847 		dmu_buf_will_dirty(db, tx);
848 
849 		ASSERT3U(db->db_size, >=, drro->drr_bonuslen);
850 		data = restore_read(ra, P2ROUNDUP(drro->drr_bonuslen, 8));
851 		if (data == NULL) {
852 			dmu_tx_commit(tx);
853 			return (ra->err);
854 		}
855 		bcopy(data, db->db_data, drro->drr_bonuslen);
856 		if (ra->byteswap) {
857 			dmu_ot[drro->drr_bonustype].ot_byteswap(db->db_data,
858 			    drro->drr_bonuslen);
859 		}
860 		dmu_buf_rele(db, FTAG);
861 	}
862 	dmu_tx_commit(tx);
863 	return (0);
864 }
865 
866 /* ARGSUSED */
867 static int
868 restore_freeobjects(struct restorearg *ra, objset_t *os,
869     struct drr_freeobjects *drrfo)
870 {
871 	uint64_t obj;
872 
873 	if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
874 		return (EINVAL);
875 
876 	for (obj = drrfo->drr_firstobj;
877 	    obj < drrfo->drr_firstobj + drrfo->drr_numobjs;
878 	    (void) dmu_object_next(os, &obj, FALSE, 0)) {
879 		dmu_tx_t *tx;
880 		int err;
881 
882 		if (dmu_object_info(os, obj, NULL) != 0)
883 			continue;
884 
885 		tx = dmu_tx_create(os);
886 		dmu_tx_hold_bonus(tx, obj);
887 		err = dmu_tx_assign(tx, TXG_WAIT);
888 		if (err) {
889 			dmu_tx_abort(tx);
890 			return (err);
891 		}
892 		err = dmu_object_free(os, obj, tx);
893 		dmu_tx_commit(tx);
894 		if (err && err != ENOENT)
895 			return (EINVAL);
896 	}
897 	return (0);
898 }
899 
900 static int
901 restore_write(struct restorearg *ra, objset_t *os,
902     struct drr_write *drrw)
903 {
904 	dmu_tx_t *tx;
905 	void *data;
906 	int err;
907 
908 	if (drrw->drr_offset + drrw->drr_length < drrw->drr_offset ||
909 	    drrw->drr_type >= DMU_OT_NUMTYPES)
910 		return (EINVAL);
911 
912 	data = restore_read(ra, drrw->drr_length);
913 	if (data == NULL)
914 		return (ra->err);
915 
916 	if (dmu_object_info(os, drrw->drr_object, NULL) != 0)
917 		return (EINVAL);
918 
919 	tx = dmu_tx_create(os);
920 
921 	dmu_tx_hold_write(tx, drrw->drr_object,
922 	    drrw->drr_offset, drrw->drr_length);
923 	err = dmu_tx_assign(tx, TXG_WAIT);
924 	if (err) {
925 		dmu_tx_abort(tx);
926 		return (err);
927 	}
928 	if (ra->byteswap)
929 		dmu_ot[drrw->drr_type].ot_byteswap(data, drrw->drr_length);
930 	dmu_write(os, drrw->drr_object,
931 	    drrw->drr_offset, drrw->drr_length, data, tx);
932 	dmu_tx_commit(tx);
933 	return (0);
934 }
935 
936 /* ARGSUSED */
937 static int
938 restore_free(struct restorearg *ra, objset_t *os,
939     struct drr_free *drrf)
940 {
941 	dmu_tx_t *tx;
942 	int err;
943 
944 	if (drrf->drr_length != -1ULL &&
945 	    drrf->drr_offset + drrf->drr_length < drrf->drr_offset)
946 		return (EINVAL);
947 
948 	if (dmu_object_info(os, drrf->drr_object, NULL) != 0)
949 		return (EINVAL);
950 
951 	tx = dmu_tx_create(os);
952 
953 	dmu_tx_hold_free(tx, drrf->drr_object,
954 	    drrf->drr_offset, drrf->drr_length);
955 	err = dmu_tx_assign(tx, TXG_WAIT);
956 	if (err) {
957 		dmu_tx_abort(tx);
958 		return (err);
959 	}
960 	err = dmu_free_range(os, drrf->drr_object,
961 	    drrf->drr_offset, drrf->drr_length, tx);
962 	dmu_tx_commit(tx);
963 	return (err);
964 }
965 
966 static void
967 recv_abort_cleanup(dmu_recv_cookie_t *drc)
968 {
969 	if (drc->drc_newfs || drc->drc_real_ds != drc->drc_logical_ds) {
970 		/*
971 		 * online incremental or new fs: destroy the fs (which
972 		 * may be a clone) that we created
973 		 */
974 		(void) dsl_dataset_destroy(drc->drc_real_ds, dmu_recv_tag);
975 		if (drc->drc_real_ds != drc->drc_logical_ds) {
976 			dsl_dataset_close(drc->drc_logical_ds,
977 			    DS_MODE_STANDARD, dmu_recv_tag);
978 		}
979 	} else {
980 		/*
981 		 * offline incremental: rollback to most recent snapshot.
982 		 */
983 		int lmode = DS_MODE_PRIMARY;
984 		if (dsl_dataset_tryupgrade(drc->drc_real_ds,
985 		    DS_MODE_PRIMARY, DS_MODE_EXCLUSIVE)) {
986 			lmode = DS_MODE_EXCLUSIVE;
987 			(void) dsl_dataset_rollback(drc->drc_real_ds,
988 			    DMU_OST_NONE);
989 		}
990 		dsl_dataset_close(drc->drc_real_ds, lmode, FTAG);
991 	}
992 }
993 
994 /*
995  * NB: callers *must* call dmu_recv_end() if this succeeds.
996  */
997 int
998 dmu_recv_stream(dmu_recv_cookie_t *drc, vnode_t *vp, offset_t *voffp)
999 {
1000 	struct restorearg ra = { 0 };
1001 	dmu_replay_record_t *drr;
1002 	objset_t *os;
1003 	zio_cksum_t pcksum;
1004 
1005 	if (drc->drc_drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC))
1006 		ra.byteswap = TRUE;
1007 
1008 	{
1009 		/* compute checksum of drr_begin record */
1010 		dmu_replay_record_t *drr;
1011 		drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
1012 
1013 		drr->drr_type = DRR_BEGIN;
1014 		drr->drr_u.drr_begin = *drc->drc_drrb;
1015 		if (ra.byteswap) {
1016 			fletcher_4_incremental_byteswap(drr,
1017 			    sizeof (dmu_replay_record_t), &ra.cksum);
1018 		} else {
1019 			fletcher_4_incremental_native(drr,
1020 			    sizeof (dmu_replay_record_t), &ra.cksum);
1021 		}
1022 		kmem_free(drr, sizeof (dmu_replay_record_t));
1023 	}
1024 
1025 	if (ra.byteswap) {
1026 		struct drr_begin *drrb = drc->drc_drrb;
1027 		drrb->drr_magic = BSWAP_64(drrb->drr_magic);
1028 		drrb->drr_version = BSWAP_64(drrb->drr_version);
1029 		drrb->drr_creation_time = BSWAP_64(drrb->drr_creation_time);
1030 		drrb->drr_type = BSWAP_32(drrb->drr_type);
1031 		drrb->drr_toguid = BSWAP_64(drrb->drr_toguid);
1032 		drrb->drr_fromguid = BSWAP_64(drrb->drr_fromguid);
1033 	}
1034 
1035 	ra.vp = vp;
1036 	ra.voff = *voffp;
1037 	ra.bufsize = 1<<20;
1038 	ra.buf = kmem_alloc(ra.bufsize, KM_SLEEP);
1039 
1040 	/* these were verified in dmu_recv_begin */
1041 	ASSERT(drc->drc_drrb->drr_version == DMU_BACKUP_STREAM_VERSION);
1042 	ASSERT(drc->drc_drrb->drr_type < DMU_OST_NUMTYPES);
1043 
1044 	/*
1045 	 * Open the objset we are modifying.
1046 	 */
1047 	VERIFY(dmu_objset_open_ds(drc->drc_real_ds, DMU_OST_ANY, &os) == 0);
1048 
1049 	ASSERT(drc->drc_real_ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT);
1050 
1051 	/*
1052 	 * Read records and process them.
1053 	 */
1054 	pcksum = ra.cksum;
1055 	while (ra.err == 0 &&
1056 	    NULL != (drr = restore_read(&ra, sizeof (*drr)))) {
1057 		if (issig(JUSTLOOKING) && issig(FORREAL)) {
1058 			ra.err = EINTR;
1059 			goto out;
1060 		}
1061 
1062 		if (ra.byteswap)
1063 			backup_byteswap(drr);
1064 
1065 		switch (drr->drr_type) {
1066 		case DRR_OBJECT:
1067 		{
1068 			/*
1069 			 * We need to make a copy of the record header,
1070 			 * because restore_{object,write} may need to
1071 			 * restore_read(), which will invalidate drr.
1072 			 */
1073 			struct drr_object drro = drr->drr_u.drr_object;
1074 			ra.err = restore_object(&ra, os, &drro);
1075 			break;
1076 		}
1077 		case DRR_FREEOBJECTS:
1078 		{
1079 			struct drr_freeobjects drrfo =
1080 			    drr->drr_u.drr_freeobjects;
1081 			ra.err = restore_freeobjects(&ra, os, &drrfo);
1082 			break;
1083 		}
1084 		case DRR_WRITE:
1085 		{
1086 			struct drr_write drrw = drr->drr_u.drr_write;
1087 			ra.err = restore_write(&ra, os, &drrw);
1088 			break;
1089 		}
1090 		case DRR_FREE:
1091 		{
1092 			struct drr_free drrf = drr->drr_u.drr_free;
1093 			ra.err = restore_free(&ra, os, &drrf);
1094 			break;
1095 		}
1096 		case DRR_END:
1097 		{
1098 			struct drr_end drre = drr->drr_u.drr_end;
1099 			/*
1100 			 * We compare against the *previous* checksum
1101 			 * value, because the stored checksum is of
1102 			 * everything before the DRR_END record.
1103 			 */
1104 			if (drre.drr_checksum.zc_word[0] != 0 &&
1105 			    !ZIO_CHECKSUM_EQUAL(drre.drr_checksum, pcksum)) {
1106 				ra.err = ECKSUM;
1107 				goto out;
1108 			}
1109 			goto out;
1110 		}
1111 		default:
1112 			ra.err = EINVAL;
1113 			goto out;
1114 		}
1115 		pcksum = ra.cksum;
1116 	}
1117 
1118 out:
1119 	dmu_objset_close(os);
1120 
1121 	if (ra.err != 0) {
1122 		/*
1123 		 * rollback or destroy what we created, so we don't
1124 		 * leave it in the restoring state.
1125 		 */
1126 		txg_wait_synced(drc->drc_real_ds->ds_dir->dd_pool, 0);
1127 		recv_abort_cleanup(drc);
1128 	}
1129 
1130 	kmem_free(ra.buf, ra.bufsize);
1131 	*voffp = ra.voff;
1132 	return (ra.err);
1133 }
1134 
1135 struct recvendsyncarg {
1136 	char *tosnap;
1137 	uint64_t creation_time;
1138 	uint64_t toguid;
1139 };
1140 
1141 static int
1142 recv_end_check(void *arg1, void *arg2, dmu_tx_t *tx)
1143 {
1144 	dsl_dataset_t *ds = arg1;
1145 	struct recvendsyncarg *resa = arg2;
1146 
1147 	return (dsl_dataset_snapshot_check(ds, resa->tosnap, tx));
1148 }
1149 
1150 static void
1151 recv_end_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
1152 {
1153 	dsl_dataset_t *ds = arg1;
1154 	struct recvendsyncarg *resa = arg2;
1155 
1156 	dsl_dataset_snapshot_sync(ds, resa->tosnap, cr, tx);
1157 
1158 	/* set snapshot's creation time and guid */
1159 	dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1160 	ds->ds_prev->ds_phys->ds_creation_time = resa->creation_time;
1161 	ds->ds_prev->ds_phys->ds_guid = resa->toguid;
1162 	ds->ds_prev->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
1163 
1164 	dmu_buf_will_dirty(ds->ds_dbuf, tx);
1165 	ds->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
1166 }
1167 
1168 int
1169 dmu_recv_end(dmu_recv_cookie_t *drc)
1170 {
1171 	int err = 0;
1172 	int lmode;
1173 
1174 	/*
1175 	 * XXX hack; seems the ds is still dirty and
1176 	 * dsl_pool_zil_clean() expects it to have a ds_user_ptr (and
1177 	 * zil), but clone_swap() can close it.
1178 	 */
1179 	txg_wait_synced(drc->drc_real_ds->ds_dir->dd_pool, 0);
1180 
1181 	if (dsl_dataset_tryupgrade(drc->drc_real_ds,
1182 	    DS_MODE_PRIMARY, DS_MODE_EXCLUSIVE)) {
1183 		lmode = DS_MODE_EXCLUSIVE;
1184 	} else {
1185 		recv_abort_cleanup(drc);
1186 		return (EBUSY);
1187 	}
1188 
1189 	if (drc->drc_logical_ds != drc->drc_real_ds) {
1190 		if (err == 0 && dsl_dataset_tryupgrade(drc->drc_logical_ds,
1191 		    DS_MODE_STANDARD, DS_MODE_EXCLUSIVE)) {
1192 			lmode = DS_MODE_EXCLUSIVE;
1193 			err = dsl_dataset_clone_swap(drc->drc_real_ds,
1194 			    drc->drc_logical_ds, drc->drc_force);
1195 		} else {
1196 			lmode = DS_MODE_STANDARD;
1197 			err = EBUSY;
1198 		}
1199 	}
1200 
1201 	if (err == 0) {
1202 		struct recvendsyncarg resa;
1203 
1204 		resa.creation_time = drc->drc_drrb->drr_creation_time;
1205 		resa.toguid = drc->drc_drrb->drr_toguid;
1206 		resa.tosnap = drc->drc_tosnap;
1207 
1208 		err = dsl_sync_task_do(drc->drc_real_ds->ds_dir->dd_pool,
1209 		    recv_end_check, recv_end_sync,
1210 		    drc->drc_logical_ds, &resa, 3);
1211 		if (err) {
1212 			if (drc->drc_newfs) {
1213 				ASSERT(drc->drc_logical_ds == drc->drc_real_ds);
1214 				(void) dsl_dataset_destroy(drc->drc_real_ds,
1215 				    dmu_recv_tag);
1216 				return (err);
1217 			} else {
1218 				(void) dsl_dataset_rollback(drc->drc_logical_ds,
1219 				    DMU_OST_NONE);
1220 			}
1221 		}
1222 	}
1223 
1224 	if (drc->drc_logical_ds != drc->drc_real_ds) {
1225 		/* dsl_dataset_destroy() will close the ds */
1226 		(void) dsl_dataset_destroy(drc->drc_real_ds, dmu_recv_tag);
1227 	}
1228 	/* close the hold from dmu_recv_begin */
1229 	dsl_dataset_close(drc->drc_logical_ds, lmode, dmu_recv_tag);
1230 	return (err);
1231 }
1232