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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
25 * Copyright (c) 2014, Joyent, Inc. All rights reserved.
26 * Copyright (c) 2012, Martin Matuska <mm@FreeBSD.org>. All rights reserved.
27 * Copyright 2014 HybridCluster. All rights reserved.
28 * Copyright 2016 RackTop Systems.
29 * Copyright (c) 2014 Integros [integros.com]
30 * Copyright (c) 2018, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
31 */
32
33#include <sys/dmu.h>
34#include <sys/dmu_impl.h>
35#include <sys/dmu_tx.h>
36#include <sys/dbuf.h>
37#include <sys/dnode.h>
38#include <sys/zfs_context.h>
39#include <sys/dmu_objset.h>
40#include <sys/dmu_traverse.h>
41#include <sys/dsl_dataset.h>
42#include <sys/dsl_dir.h>
43#include <sys/dsl_prop.h>
44#include <sys/dsl_pool.h>
45#include <sys/dsl_synctask.h>
46#include <sys/zfs_ioctl.h>
47#include <sys/zap.h>
48#include <sys/zio_checksum.h>
49#include <sys/zfs_znode.h>
50#include <zfs_fletcher.h>
51#include <sys/avl.h>
52#include <sys/ddt.h>
53#include <sys/zfs_onexit.h>
54#include <sys/dmu_send.h>
55#include <sys/dsl_destroy.h>
56#include <sys/blkptr.h>
57#include <sys/dsl_bookmark.h>
58#include <sys/zfeature.h>
59#include <sys/bqueue.h>
60#ifdef __FreeBSD__
61#include <sys/zvol.h>
62#endif
63
64#ifdef __FreeBSD__
65#undef dump_write
66#define dump_write dmu_dump_write
67#endif
68
69/* Set this tunable to TRUE to replace corrupt data with 0x2f5baddb10c */
70int zfs_send_corrupt_data = B_FALSE;
71int zfs_send_queue_length = 16 * 1024 * 1024;
72int zfs_recv_queue_length = 16 * 1024 * 1024;
73/* Set this tunable to FALSE to disable setting of DRR_FLAG_FREERECORDS */
74int zfs_send_set_freerecords_bit = B_TRUE;
75
76#ifdef _KERNEL
77TUNABLE_INT("vfs.zfs.send_set_freerecords_bit", &zfs_send_set_freerecords_bit);
78#endif
79
80static char *dmu_recv_tag = "dmu_recv_tag";
81const char *recv_clone_name = "%recv";
82
83/*
84 * Use this to override the recordsize calculation for fast zfs send estimates.
85 */
86uint64_t zfs_override_estimate_recordsize = 0;
87
88#define	BP_SPAN(datablkszsec, indblkshift, level) \
89	(((uint64_t)datablkszsec) << (SPA_MINBLOCKSHIFT + \
90	(level) * (indblkshift - SPA_BLKPTRSHIFT)))
91
92static void byteswap_record(dmu_replay_record_t *drr);
93
94struct send_thread_arg {
95	bqueue_t	q;
96	dsl_dataset_t	*ds;		/* Dataset to traverse */
97	uint64_t	fromtxg;	/* Traverse from this txg */
98	int		flags;		/* flags to pass to traverse_dataset */
99	int		error_code;
100	boolean_t	cancel;
101	zbookmark_phys_t resume;
102};
103
104struct send_block_record {
105	boolean_t		eos_marker; /* Marks the end of the stream */
106	blkptr_t		bp;
107	zbookmark_phys_t	zb;
108	uint8_t			indblkshift;
109	uint16_t		datablkszsec;
110	bqueue_node_t		ln;
111};
112
113static int
114dump_bytes(dmu_sendarg_t *dsp, void *buf, int len)
115{
116	dsl_dataset_t *ds = dmu_objset_ds(dsp->dsa_os);
117	struct uio auio;
118	struct iovec aiov;
119
120	/*
121	 * The code does not rely on this (len being a multiple of 8).  We keep
122	 * this assertion because of the corresponding assertion in
123	 * receive_read().  Keeping this assertion ensures that we do not
124	 * inadvertently break backwards compatibility (causing the assertion
125	 * in receive_read() to trigger on old software).
126	 *
127	 * Removing the assertions could be rolled into a new feature that uses
128	 * data that isn't 8-byte aligned; if the assertions were removed, a
129	 * feature flag would have to be added.
130	 */
131
132	ASSERT0(len % 8);
133
134	aiov.iov_base = buf;
135	aiov.iov_len = len;
136	auio.uio_iov = &aiov;
137	auio.uio_iovcnt = 1;
138	auio.uio_resid = len;
139	auio.uio_segflg = UIO_SYSSPACE;
140	auio.uio_rw = UIO_WRITE;
141	auio.uio_offset = (off_t)-1;
142	auio.uio_td = dsp->dsa_td;
143#ifdef _KERNEL
144	if (dsp->dsa_fp->f_type == DTYPE_VNODE)
145		bwillwrite();
146	dsp->dsa_err = fo_write(dsp->dsa_fp, &auio, dsp->dsa_td->td_ucred, 0,
147	    dsp->dsa_td);
148#else
149	fprintf(stderr, "%s: returning EOPNOTSUPP\n", __func__);
150	dsp->dsa_err = EOPNOTSUPP;
151#endif
152	mutex_enter(&ds->ds_sendstream_lock);
153	*dsp->dsa_off += len;
154	mutex_exit(&ds->ds_sendstream_lock);
155
156	return (dsp->dsa_err);
157}
158
159/*
160 * For all record types except BEGIN, fill in the checksum (overlaid in
161 * drr_u.drr_checksum.drr_checksum).  The checksum verifies everything
162 * up to the start of the checksum itself.
163 */
164static int
165dump_record(dmu_sendarg_t *dsp, void *payload, int payload_len)
166{
167	ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
168	    ==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
169	(void) fletcher_4_incremental_native(dsp->dsa_drr,
170	    offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
171	    &dsp->dsa_zc);
172	if (dsp->dsa_drr->drr_type == DRR_BEGIN) {
173		dsp->dsa_sent_begin = B_TRUE;
174	} else {
175		ASSERT(ZIO_CHECKSUM_IS_ZERO(&dsp->dsa_drr->drr_u.
176		    drr_checksum.drr_checksum));
177		dsp->dsa_drr->drr_u.drr_checksum.drr_checksum = dsp->dsa_zc;
178	}
179	if (dsp->dsa_drr->drr_type == DRR_END) {
180		dsp->dsa_sent_end = B_TRUE;
181	}
182	(void) fletcher_4_incremental_native(&dsp->dsa_drr->
183	    drr_u.drr_checksum.drr_checksum,
184	    sizeof (zio_cksum_t), &dsp->dsa_zc);
185	if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
186		return (SET_ERROR(EINTR));
187	if (payload_len != 0) {
188		(void) fletcher_4_incremental_native(payload, payload_len,
189		    &dsp->dsa_zc);
190		if (dump_bytes(dsp, payload, payload_len) != 0)
191			return (SET_ERROR(EINTR));
192	}
193	return (0);
194}
195
196/*
197 * Fill in the drr_free struct, or perform aggregation if the previous record is
198 * also a free record, and the two are adjacent.
199 *
200 * Note that we send free records even for a full send, because we want to be
201 * able to receive a full send as a clone, which requires a list of all the free
202 * and freeobject records that were generated on the source.
203 */
204static int
205dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
206    uint64_t length)
207{
208	struct drr_free *drrf = &(dsp->dsa_drr->drr_u.drr_free);
209
210	/*
211	 * When we receive a free record, dbuf_free_range() assumes
212	 * that the receiving system doesn't have any dbufs in the range
213	 * being freed.  This is always true because there is a one-record
214	 * constraint: we only send one WRITE record for any given
215	 * object,offset.  We know that the one-record constraint is
216	 * true because we always send data in increasing order by
217	 * object,offset.
218	 *
219	 * If the increasing-order constraint ever changes, we should find
220	 * another way to assert that the one-record constraint is still
221	 * satisfied.
222	 */
223	ASSERT(object > dsp->dsa_last_data_object ||
224	    (object == dsp->dsa_last_data_object &&
225	    offset > dsp->dsa_last_data_offset));
226
227	if (length != -1ULL && offset + length < offset)
228		length = -1ULL;
229
230	/*
231	 * If there is a pending op, but it's not PENDING_FREE, push it out,
232	 * since free block aggregation can only be done for blocks of the
233	 * same type (i.e., DRR_FREE records can only be aggregated with
234	 * other DRR_FREE records.  DRR_FREEOBJECTS records can only be
235	 * aggregated with other DRR_FREEOBJECTS records.
236	 */
237	if (dsp->dsa_pending_op != PENDING_NONE &&
238	    dsp->dsa_pending_op != PENDING_FREE) {
239		if (dump_record(dsp, NULL, 0) != 0)
240			return (SET_ERROR(EINTR));
241		dsp->dsa_pending_op = PENDING_NONE;
242	}
243
244	if (dsp->dsa_pending_op == PENDING_FREE) {
245		/*
246		 * There should never be a PENDING_FREE if length is -1
247		 * (because dump_dnode is the only place where this
248		 * function is called with a -1, and only after flushing
249		 * any pending record).
250		 */
251		ASSERT(length != -1ULL);
252		/*
253		 * Check to see whether this free block can be aggregated
254		 * with pending one.
255		 */
256		if (drrf->drr_object == object && drrf->drr_offset +
257		    drrf->drr_length == offset) {
258			drrf->drr_length += length;
259			return (0);
260		} else {
261			/* not a continuation.  Push out pending record */
262			if (dump_record(dsp, NULL, 0) != 0)
263				return (SET_ERROR(EINTR));
264			dsp->dsa_pending_op = PENDING_NONE;
265		}
266	}
267	/* create a FREE record and make it pending */
268	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
269	dsp->dsa_drr->drr_type = DRR_FREE;
270	drrf->drr_object = object;
271	drrf->drr_offset = offset;
272	drrf->drr_length = length;
273	drrf->drr_toguid = dsp->dsa_toguid;
274	if (length == -1ULL) {
275		if (dump_record(dsp, NULL, 0) != 0)
276			return (SET_ERROR(EINTR));
277	} else {
278		dsp->dsa_pending_op = PENDING_FREE;
279	}
280
281	return (0);
282}
283
284static int
285dump_write(dmu_sendarg_t *dsp, dmu_object_type_t type,
286    uint64_t object, uint64_t offset, int lsize, int psize, const blkptr_t *bp,
287    void *data)
288{
289	uint64_t payload_size;
290	struct drr_write *drrw = &(dsp->dsa_drr->drr_u.drr_write);
291
292	/*
293	 * We send data in increasing object, offset order.
294	 * See comment in dump_free() for details.
295	 */
296	ASSERT(object > dsp->dsa_last_data_object ||
297	    (object == dsp->dsa_last_data_object &&
298	    offset > dsp->dsa_last_data_offset));
299	dsp->dsa_last_data_object = object;
300	dsp->dsa_last_data_offset = offset + lsize - 1;
301
302	/*
303	 * If there is any kind of pending aggregation (currently either
304	 * a grouping of free objects or free blocks), push it out to
305	 * the stream, since aggregation can't be done across operations
306	 * of different types.
307	 */
308	if (dsp->dsa_pending_op != PENDING_NONE) {
309		if (dump_record(dsp, NULL, 0) != 0)
310			return (SET_ERROR(EINTR));
311		dsp->dsa_pending_op = PENDING_NONE;
312	}
313	/* write a WRITE record */
314	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
315	dsp->dsa_drr->drr_type = DRR_WRITE;
316	drrw->drr_object = object;
317	drrw->drr_type = type;
318	drrw->drr_offset = offset;
319	drrw->drr_toguid = dsp->dsa_toguid;
320	drrw->drr_logical_size = lsize;
321
322	/* only set the compression fields if the buf is compressed */
323	if (lsize != psize) {
324		ASSERT(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_COMPRESSED);
325		ASSERT(!BP_IS_EMBEDDED(bp));
326		ASSERT(!BP_SHOULD_BYTESWAP(bp));
327		ASSERT(!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)));
328		ASSERT3U(BP_GET_COMPRESS(bp), !=, ZIO_COMPRESS_OFF);
329		ASSERT3S(psize, >, 0);
330		ASSERT3S(lsize, >=, psize);
331
332		drrw->drr_compressiontype = BP_GET_COMPRESS(bp);
333		drrw->drr_compressed_size = psize;
334		payload_size = drrw->drr_compressed_size;
335	} else {
336		payload_size = drrw->drr_logical_size;
337	}
338
339	if (bp == NULL || BP_IS_EMBEDDED(bp)) {
340		/*
341		 * There's no pre-computed checksum for partial-block
342		 * writes or embedded BP's, so (like
343		 * fletcher4-checkummed blocks) userland will have to
344		 * compute a dedup-capable checksum itself.
345		 */
346		drrw->drr_checksumtype = ZIO_CHECKSUM_OFF;
347	} else {
348		drrw->drr_checksumtype = BP_GET_CHECKSUM(bp);
349		if (zio_checksum_table[drrw->drr_checksumtype].ci_flags &
350		    ZCHECKSUM_FLAG_DEDUP)
351			drrw->drr_checksumflags |= DRR_CHECKSUM_DEDUP;
352		DDK_SET_LSIZE(&drrw->drr_key, BP_GET_LSIZE(bp));
353		DDK_SET_PSIZE(&drrw->drr_key, BP_GET_PSIZE(bp));
354		DDK_SET_COMPRESS(&drrw->drr_key, BP_GET_COMPRESS(bp));
355		drrw->drr_key.ddk_cksum = bp->blk_cksum;
356	}
357
358	if (dump_record(dsp, data, payload_size) != 0)
359		return (SET_ERROR(EINTR));
360	return (0);
361}
362
363static int
364dump_write_embedded(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
365    int blksz, const blkptr_t *bp)
366{
367	char buf[BPE_PAYLOAD_SIZE];
368	struct drr_write_embedded *drrw =
369	    &(dsp->dsa_drr->drr_u.drr_write_embedded);
370
371	if (dsp->dsa_pending_op != PENDING_NONE) {
372		if (dump_record(dsp, NULL, 0) != 0)
373			return (EINTR);
374		dsp->dsa_pending_op = PENDING_NONE;
375	}
376
377	ASSERT(BP_IS_EMBEDDED(bp));
378
379	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
380	dsp->dsa_drr->drr_type = DRR_WRITE_EMBEDDED;
381	drrw->drr_object = object;
382	drrw->drr_offset = offset;
383	drrw->drr_length = blksz;
384	drrw->drr_toguid = dsp->dsa_toguid;
385	drrw->drr_compression = BP_GET_COMPRESS(bp);
386	drrw->drr_etype = BPE_GET_ETYPE(bp);
387	drrw->drr_lsize = BPE_GET_LSIZE(bp);
388	drrw->drr_psize = BPE_GET_PSIZE(bp);
389
390	decode_embedded_bp_compressed(bp, buf);
391
392	if (dump_record(dsp, buf, P2ROUNDUP(drrw->drr_psize, 8)) != 0)
393		return (EINTR);
394	return (0);
395}
396
397static int
398dump_spill(dmu_sendarg_t *dsp, uint64_t object, int blksz, void *data)
399{
400	struct drr_spill *drrs = &(dsp->dsa_drr->drr_u.drr_spill);
401
402	if (dsp->dsa_pending_op != PENDING_NONE) {
403		if (dump_record(dsp, NULL, 0) != 0)
404			return (SET_ERROR(EINTR));
405		dsp->dsa_pending_op = PENDING_NONE;
406	}
407
408	/* write a SPILL record */
409	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
410	dsp->dsa_drr->drr_type = DRR_SPILL;
411	drrs->drr_object = object;
412	drrs->drr_length = blksz;
413	drrs->drr_toguid = dsp->dsa_toguid;
414
415	if (dump_record(dsp, data, blksz) != 0)
416		return (SET_ERROR(EINTR));
417	return (0);
418}
419
420static int
421dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
422{
423	struct drr_freeobjects *drrfo = &(dsp->dsa_drr->drr_u.drr_freeobjects);
424
425	/*
426	 * If there is a pending op, but it's not PENDING_FREEOBJECTS,
427	 * push it out, since free block aggregation can only be done for
428	 * blocks of the same type (i.e., DRR_FREE records can only be
429	 * aggregated with other DRR_FREE records.  DRR_FREEOBJECTS records
430	 * can only be aggregated with other DRR_FREEOBJECTS records.
431	 */
432	if (dsp->dsa_pending_op != PENDING_NONE &&
433	    dsp->dsa_pending_op != PENDING_FREEOBJECTS) {
434		if (dump_record(dsp, NULL, 0) != 0)
435			return (SET_ERROR(EINTR));
436		dsp->dsa_pending_op = PENDING_NONE;
437	}
438	if (dsp->dsa_pending_op == PENDING_FREEOBJECTS) {
439		/*
440		 * See whether this free object array can be aggregated
441		 * with pending one
442		 */
443		if (drrfo->drr_firstobj + drrfo->drr_numobjs == firstobj) {
444			drrfo->drr_numobjs += numobjs;
445			return (0);
446		} else {
447			/* can't be aggregated.  Push out pending record */
448			if (dump_record(dsp, NULL, 0) != 0)
449				return (SET_ERROR(EINTR));
450			dsp->dsa_pending_op = PENDING_NONE;
451		}
452	}
453
454	/* write a FREEOBJECTS record */
455	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
456	dsp->dsa_drr->drr_type = DRR_FREEOBJECTS;
457	drrfo->drr_firstobj = firstobj;
458	drrfo->drr_numobjs = numobjs;
459	drrfo->drr_toguid = dsp->dsa_toguid;
460
461	dsp->dsa_pending_op = PENDING_FREEOBJECTS;
462
463	return (0);
464}
465
466static int
467dump_dnode(dmu_sendarg_t *dsp, uint64_t object, dnode_phys_t *dnp)
468{
469	struct drr_object *drro = &(dsp->dsa_drr->drr_u.drr_object);
470
471	if (object < dsp->dsa_resume_object) {
472		/*
473		 * Note: when resuming, we will visit all the dnodes in
474		 * the block of dnodes that we are resuming from.  In
475		 * this case it's unnecessary to send the dnodes prior to
476		 * the one we are resuming from.  We should be at most one
477		 * block's worth of dnodes behind the resume point.
478		 */
479		ASSERT3U(dsp->dsa_resume_object - object, <,
480		    1 << (DNODE_BLOCK_SHIFT - DNODE_SHIFT));
481		return (0);
482	}
483
484	if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
485		return (dump_freeobjects(dsp, object, 1));
486
487	if (dsp->dsa_pending_op != PENDING_NONE) {
488		if (dump_record(dsp, NULL, 0) != 0)
489			return (SET_ERROR(EINTR));
490		dsp->dsa_pending_op = PENDING_NONE;
491	}
492
493	/* write an OBJECT record */
494	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
495	dsp->dsa_drr->drr_type = DRR_OBJECT;
496	drro->drr_object = object;
497	drro->drr_type = dnp->dn_type;
498	drro->drr_bonustype = dnp->dn_bonustype;
499	drro->drr_blksz = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
500	drro->drr_bonuslen = dnp->dn_bonuslen;
501	drro->drr_dn_slots = dnp->dn_extra_slots + 1;
502	drro->drr_checksumtype = dnp->dn_checksum;
503	drro->drr_compress = dnp->dn_compress;
504	drro->drr_toguid = dsp->dsa_toguid;
505
506	if (!(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
507	    drro->drr_blksz > SPA_OLD_MAXBLOCKSIZE)
508		drro->drr_blksz = SPA_OLD_MAXBLOCKSIZE;
509
510	if (dump_record(dsp, DN_BONUS(dnp),
511	    P2ROUNDUP(dnp->dn_bonuslen, 8)) != 0) {
512		return (SET_ERROR(EINTR));
513	}
514
515	/* Free anything past the end of the file. */
516	if (dump_free(dsp, object, (dnp->dn_maxblkid + 1) *
517	    (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL) != 0)
518		return (SET_ERROR(EINTR));
519	if (dsp->dsa_err != 0)
520		return (SET_ERROR(EINTR));
521	return (0);
522}
523
524static boolean_t
525backup_do_embed(dmu_sendarg_t *dsp, const blkptr_t *bp)
526{
527	if (!BP_IS_EMBEDDED(bp))
528		return (B_FALSE);
529
530	/*
531	 * Compression function must be legacy, or explicitly enabled.
532	 */
533	if ((BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_LEGACY_FUNCTIONS &&
534	    !(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_LZ4)))
535		return (B_FALSE);
536
537	/*
538	 * Embed type must be explicitly enabled.
539	 */
540	switch (BPE_GET_ETYPE(bp)) {
541	case BP_EMBEDDED_TYPE_DATA:
542		if (dsp->dsa_featureflags & DMU_BACKUP_FEATURE_EMBED_DATA)
543			return (B_TRUE);
544		break;
545	default:
546		return (B_FALSE);
547	}
548	return (B_FALSE);
549}
550
551/*
552 * This is the callback function to traverse_dataset that acts as the worker
553 * thread for dmu_send_impl.
554 */
555/*ARGSUSED*/
556static int
557send_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
558    const zbookmark_phys_t *zb, const struct dnode_phys *dnp, void *arg)
559{
560	struct send_thread_arg *sta = arg;
561	struct send_block_record *record;
562	uint64_t record_size;
563	int err = 0;
564
565	ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT ||
566	    zb->zb_object >= sta->resume.zb_object);
567
568	if (sta->cancel)
569		return (SET_ERROR(EINTR));
570
571	if (bp == NULL) {
572		ASSERT3U(zb->zb_level, ==, ZB_DNODE_LEVEL);
573		return (0);
574	} else if (zb->zb_level < 0) {
575		return (0);
576	}
577
578	record = kmem_zalloc(sizeof (struct send_block_record), KM_SLEEP);
579	record->eos_marker = B_FALSE;
580	record->bp = *bp;
581	record->zb = *zb;
582	record->indblkshift = dnp->dn_indblkshift;
583	record->datablkszsec = dnp->dn_datablkszsec;
584	record_size = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
585	bqueue_enqueue(&sta->q, record, record_size);
586
587	return (err);
588}
589
590/*
591 * This function kicks off the traverse_dataset.  It also handles setting the
592 * error code of the thread in case something goes wrong, and pushes the End of
593 * Stream record when the traverse_dataset call has finished.  If there is no
594 * dataset to traverse, the thread immediately pushes End of Stream marker.
595 */
596static void
597send_traverse_thread(void *arg)
598{
599	struct send_thread_arg *st_arg = arg;
600	int err;
601	struct send_block_record *data;
602
603	if (st_arg->ds != NULL) {
604		err = traverse_dataset_resume(st_arg->ds,
605		    st_arg->fromtxg, &st_arg->resume,
606		    st_arg->flags, send_cb, st_arg);
607
608		if (err != EINTR)
609			st_arg->error_code = err;
610	}
611	data = kmem_zalloc(sizeof (*data), KM_SLEEP);
612	data->eos_marker = B_TRUE;
613	bqueue_enqueue(&st_arg->q, data, 1);
614	thread_exit();
615}
616
617/*
618 * This function actually handles figuring out what kind of record needs to be
619 * dumped, reading the data (which has hopefully been prefetched), and calling
620 * the appropriate helper function.
621 */
622static int
623do_dump(dmu_sendarg_t *dsa, struct send_block_record *data)
624{
625	dsl_dataset_t *ds = dmu_objset_ds(dsa->dsa_os);
626	const blkptr_t *bp = &data->bp;
627	const zbookmark_phys_t *zb = &data->zb;
628	uint8_t indblkshift = data->indblkshift;
629	uint16_t dblkszsec = data->datablkszsec;
630	spa_t *spa = ds->ds_dir->dd_pool->dp_spa;
631	dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
632	int err = 0;
633
634	ASSERT3U(zb->zb_level, >=, 0);
635
636	ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT ||
637	    zb->zb_object >= dsa->dsa_resume_object);
638
639	if (zb->zb_object != DMU_META_DNODE_OBJECT &&
640	    DMU_OBJECT_IS_SPECIAL(zb->zb_object)) {
641		return (0);
642	} else if (BP_IS_HOLE(bp) &&
643	    zb->zb_object == DMU_META_DNODE_OBJECT) {
644		uint64_t span = BP_SPAN(dblkszsec, indblkshift, zb->zb_level);
645		uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
646		err = dump_freeobjects(dsa, dnobj, span >> DNODE_SHIFT);
647	} else if (BP_IS_HOLE(bp)) {
648		uint64_t span = BP_SPAN(dblkszsec, indblkshift, zb->zb_level);
649		uint64_t offset = zb->zb_blkid * span;
650		err = dump_free(dsa, zb->zb_object, offset, span);
651	} else if (zb->zb_level > 0 || type == DMU_OT_OBJSET) {
652		return (0);
653	} else if (type == DMU_OT_DNODE) {
654		int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
655		arc_flags_t aflags = ARC_FLAG_WAIT;
656		arc_buf_t *abuf;
657
658		ASSERT0(zb->zb_level);
659
660		if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
661		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
662		    &aflags, zb) != 0)
663			return (SET_ERROR(EIO));
664
665		dnode_phys_t *blk = abuf->b_data;
666		uint64_t dnobj = zb->zb_blkid * epb;
667		for (int i = 0; i < epb; i += blk[i].dn_extra_slots + 1) {
668			err = dump_dnode(dsa, dnobj + i, blk + i);
669			if (err != 0)
670				break;
671		}
672		arc_buf_destroy(abuf, &abuf);
673	} else if (type == DMU_OT_SA) {
674		arc_flags_t aflags = ARC_FLAG_WAIT;
675		arc_buf_t *abuf;
676		int blksz = BP_GET_LSIZE(bp);
677
678		if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
679		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
680		    &aflags, zb) != 0)
681			return (SET_ERROR(EIO));
682
683		err = dump_spill(dsa, zb->zb_object, blksz, abuf->b_data);
684		arc_buf_destroy(abuf, &abuf);
685	} else if (backup_do_embed(dsa, bp)) {
686		/* it's an embedded level-0 block of a regular object */
687		int blksz = dblkszsec << SPA_MINBLOCKSHIFT;
688		ASSERT0(zb->zb_level);
689		err = dump_write_embedded(dsa, zb->zb_object,
690		    zb->zb_blkid * blksz, blksz, bp);
691	} else {
692		/* it's a level-0 block of a regular object */
693		arc_flags_t aflags = ARC_FLAG_WAIT;
694		arc_buf_t *abuf;
695		int blksz = dblkszsec << SPA_MINBLOCKSHIFT;
696		uint64_t offset;
697
698		/*
699		 * If we have large blocks stored on disk but the send flags
700		 * don't allow us to send large blocks, we split the data from
701		 * the arc buf into chunks.
702		 */
703		boolean_t split_large_blocks = blksz > SPA_OLD_MAXBLOCKSIZE &&
704		    !(dsa->dsa_featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS);
705		/*
706		 * We should only request compressed data from the ARC if all
707		 * the following are true:
708		 *  - stream compression was requested
709		 *  - we aren't splitting large blocks into smaller chunks
710		 *  - the data won't need to be byteswapped before sending
711		 *  - this isn't an embedded block
712		 *  - this isn't metadata (if receiving on a different endian
713		 *    system it can be byteswapped more easily)
714		 */
715		boolean_t request_compressed =
716		    (dsa->dsa_featureflags & DMU_BACKUP_FEATURE_COMPRESSED) &&
717		    !split_large_blocks && !BP_SHOULD_BYTESWAP(bp) &&
718		    !BP_IS_EMBEDDED(bp) && !DMU_OT_IS_METADATA(BP_GET_TYPE(bp));
719
720		ASSERT0(zb->zb_level);
721		ASSERT(zb->zb_object > dsa->dsa_resume_object ||
722		    (zb->zb_object == dsa->dsa_resume_object &&
723		    zb->zb_blkid * blksz >= dsa->dsa_resume_offset));
724
725		ASSERT0(zb->zb_level);
726		ASSERT(zb->zb_object > dsa->dsa_resume_object ||
727		    (zb->zb_object == dsa->dsa_resume_object &&
728		    zb->zb_blkid * blksz >= dsa->dsa_resume_offset));
729
730		ASSERT3U(blksz, ==, BP_GET_LSIZE(bp));
731
732		enum zio_flag zioflags = ZIO_FLAG_CANFAIL;
733		if (request_compressed)
734			zioflags |= ZIO_FLAG_RAW;
735		if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
736		    ZIO_PRIORITY_ASYNC_READ, zioflags, &aflags, zb) != 0) {
737			if (zfs_send_corrupt_data) {
738				/* Send a block filled with 0x"zfs badd bloc" */
739				abuf = arc_alloc_buf(spa, &abuf, ARC_BUFC_DATA,
740				    blksz);
741				uint64_t *ptr;
742				for (ptr = abuf->b_data;
743				    (char *)ptr < (char *)abuf->b_data + blksz;
744				    ptr++)
745					*ptr = 0x2f5baddb10cULL;
746			} else {
747				return (SET_ERROR(EIO));
748			}
749		}
750
751		offset = zb->zb_blkid * blksz;
752
753		if (split_large_blocks) {
754			ASSERT3U(arc_get_compression(abuf), ==,
755			    ZIO_COMPRESS_OFF);
756			char *buf = abuf->b_data;
757			while (blksz > 0 && err == 0) {
758				int n = MIN(blksz, SPA_OLD_MAXBLOCKSIZE);
759				err = dump_write(dsa, type, zb->zb_object,
760				    offset, n, n, NULL, buf);
761				offset += n;
762				buf += n;
763				blksz -= n;
764			}
765		} else {
766			err = dump_write(dsa, type, zb->zb_object, offset,
767			    blksz, arc_buf_size(abuf), bp, abuf->b_data);
768		}
769		arc_buf_destroy(abuf, &abuf);
770	}
771
772	ASSERT(err == 0 || err == EINTR);
773	return (err);
774}
775
776/*
777 * Pop the new data off the queue, and free the old data.
778 */
779static struct send_block_record *
780get_next_record(bqueue_t *bq, struct send_block_record *data)
781{
782	struct send_block_record *tmp = bqueue_dequeue(bq);
783	kmem_free(data, sizeof (*data));
784	return (tmp);
785}
786
787/*
788 * Actually do the bulk of the work in a zfs send.
789 *
790 * Note: Releases dp using the specified tag.
791 */
792static int
793dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
794    zfs_bookmark_phys_t *ancestor_zb, boolean_t is_clone,
795    boolean_t embedok, boolean_t large_block_ok, boolean_t compressok,
796    int outfd, uint64_t resumeobj, uint64_t resumeoff,
797#ifdef illumos
798    vnode_t *vp, offset_t *off)
799#else
800    struct file *fp, offset_t *off)
801#endif
802{
803	objset_t *os;
804	dmu_replay_record_t *drr;
805	dmu_sendarg_t *dsp;
806	int err;
807	uint64_t fromtxg = 0;
808	uint64_t featureflags = 0;
809	struct send_thread_arg to_arg = { 0 };
810
811	err = dmu_objset_from_ds(to_ds, &os);
812	if (err != 0) {
813		dsl_pool_rele(dp, tag);
814		return (err);
815	}
816
817	drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
818	drr->drr_type = DRR_BEGIN;
819	drr->drr_u.drr_begin.drr_magic = DMU_BACKUP_MAGIC;
820	DMU_SET_STREAM_HDRTYPE(drr->drr_u.drr_begin.drr_versioninfo,
821	    DMU_SUBSTREAM);
822
823#ifdef _KERNEL
824	if (dmu_objset_type(os) == DMU_OST_ZFS) {
825		uint64_t version;
826		if (zfs_get_zplprop(os, ZFS_PROP_VERSION, &version) != 0) {
827			kmem_free(drr, sizeof (dmu_replay_record_t));
828			dsl_pool_rele(dp, tag);
829			return (SET_ERROR(EINVAL));
830		}
831		if (version >= ZPL_VERSION_SA) {
832			featureflags |= DMU_BACKUP_FEATURE_SA_SPILL;
833		}
834	}
835#endif
836
837	if (large_block_ok && to_ds->ds_feature_inuse[SPA_FEATURE_LARGE_BLOCKS])
838		featureflags |= DMU_BACKUP_FEATURE_LARGE_BLOCKS;
839	if (to_ds->ds_feature_inuse[SPA_FEATURE_LARGE_DNODE])
840		featureflags |= DMU_BACKUP_FEATURE_LARGE_DNODE;
841	if (embedok &&
842	    spa_feature_is_active(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA)) {
843		featureflags |= DMU_BACKUP_FEATURE_EMBED_DATA;
844		if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
845			featureflags |= DMU_BACKUP_FEATURE_LZ4;
846	}
847	if (compressok) {
848		featureflags |= DMU_BACKUP_FEATURE_COMPRESSED;
849	}
850	if ((featureflags &
851	    (DMU_BACKUP_FEATURE_EMBED_DATA | DMU_BACKUP_FEATURE_COMPRESSED)) !=
852	    0 && spa_feature_is_active(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS)) {
853		featureflags |= DMU_BACKUP_FEATURE_LZ4;
854	}
855
856	if (resumeobj != 0 || resumeoff != 0) {
857		featureflags |= DMU_BACKUP_FEATURE_RESUMING;
858	}
859
860	DMU_SET_FEATUREFLAGS(drr->drr_u.drr_begin.drr_versioninfo,
861	    featureflags);
862
863	drr->drr_u.drr_begin.drr_creation_time =
864	    dsl_dataset_phys(to_ds)->ds_creation_time;
865	drr->drr_u.drr_begin.drr_type = dmu_objset_type(os);
866	if (is_clone)
867		drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CLONE;
868	drr->drr_u.drr_begin.drr_toguid = dsl_dataset_phys(to_ds)->ds_guid;
869	if (dsl_dataset_phys(to_ds)->ds_flags & DS_FLAG_CI_DATASET)
870		drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CI_DATA;
871	if (zfs_send_set_freerecords_bit)
872		drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_FREERECORDS;
873
874	if (ancestor_zb != NULL) {
875		drr->drr_u.drr_begin.drr_fromguid =
876		    ancestor_zb->zbm_guid;
877		fromtxg = ancestor_zb->zbm_creation_txg;
878	}
879	dsl_dataset_name(to_ds, drr->drr_u.drr_begin.drr_toname);
880	if (!to_ds->ds_is_snapshot) {
881		(void) strlcat(drr->drr_u.drr_begin.drr_toname, "@--head--",
882		    sizeof (drr->drr_u.drr_begin.drr_toname));
883	}
884
885	dsp = kmem_zalloc(sizeof (dmu_sendarg_t), KM_SLEEP);
886
887	dsp->dsa_drr = drr;
888	dsp->dsa_outfd = outfd;
889	dsp->dsa_proc = curproc;
890	dsp->dsa_td = curthread;
891	dsp->dsa_fp = fp;
892	dsp->dsa_os = os;
893	dsp->dsa_off = off;
894	dsp->dsa_toguid = dsl_dataset_phys(to_ds)->ds_guid;
895	dsp->dsa_pending_op = PENDING_NONE;
896	dsp->dsa_featureflags = featureflags;
897	dsp->dsa_resume_object = resumeobj;
898	dsp->dsa_resume_offset = resumeoff;
899
900	mutex_enter(&to_ds->ds_sendstream_lock);
901	list_insert_head(&to_ds->ds_sendstreams, dsp);
902	mutex_exit(&to_ds->ds_sendstream_lock);
903
904	dsl_dataset_long_hold(to_ds, FTAG);
905	dsl_pool_rele(dp, tag);
906
907	void *payload = NULL;
908	size_t payload_len = 0;
909	if (resumeobj != 0 || resumeoff != 0) {
910		dmu_object_info_t to_doi;
911		err = dmu_object_info(os, resumeobj, &to_doi);
912		if (err != 0)
913			goto out;
914		SET_BOOKMARK(&to_arg.resume, to_ds->ds_object, resumeobj, 0,
915		    resumeoff / to_doi.doi_data_block_size);
916
917		nvlist_t *nvl = fnvlist_alloc();
918		fnvlist_add_uint64(nvl, "resume_object", resumeobj);
919		fnvlist_add_uint64(nvl, "resume_offset", resumeoff);
920		payload = fnvlist_pack(nvl, &payload_len);
921		drr->drr_payloadlen = payload_len;
922		fnvlist_free(nvl);
923	}
924
925	err = dump_record(dsp, payload, payload_len);
926	fnvlist_pack_free(payload, payload_len);
927	if (err != 0) {
928		err = dsp->dsa_err;
929		goto out;
930	}
931
932	err = bqueue_init(&to_arg.q, zfs_send_queue_length,
933	    offsetof(struct send_block_record, ln));
934	to_arg.error_code = 0;
935	to_arg.cancel = B_FALSE;
936	to_arg.ds = to_ds;
937	to_arg.fromtxg = fromtxg;
938	to_arg.flags = TRAVERSE_PRE | TRAVERSE_PREFETCH;
939	(void) thread_create(NULL, 0, send_traverse_thread, &to_arg, 0, &p0,
940	    TS_RUN, minclsyspri);
941
942	struct send_block_record *to_data;
943	to_data = bqueue_dequeue(&to_arg.q);
944
945	while (!to_data->eos_marker && err == 0) {
946		err = do_dump(dsp, to_data);
947		to_data = get_next_record(&to_arg.q, to_data);
948		if (issig(JUSTLOOKING) && issig(FORREAL))
949			err = EINTR;
950	}
951
952	if (err != 0) {
953		to_arg.cancel = B_TRUE;
954		while (!to_data->eos_marker) {
955			to_data = get_next_record(&to_arg.q, to_data);
956		}
957	}
958	kmem_free(to_data, sizeof (*to_data));
959
960	bqueue_destroy(&to_arg.q);
961
962	if (err == 0 && to_arg.error_code != 0)
963		err = to_arg.error_code;
964
965	if (err != 0)
966		goto out;
967
968	if (dsp->dsa_pending_op != PENDING_NONE)
969		if (dump_record(dsp, NULL, 0) != 0)
970			err = SET_ERROR(EINTR);
971
972	if (err != 0) {
973		if (err == EINTR && dsp->dsa_err != 0)
974			err = dsp->dsa_err;
975		goto out;
976	}
977
978	bzero(drr, sizeof (dmu_replay_record_t));
979	drr->drr_type = DRR_END;
980	drr->drr_u.drr_end.drr_checksum = dsp->dsa_zc;
981	drr->drr_u.drr_end.drr_toguid = dsp->dsa_toguid;
982
983	if (dump_record(dsp, NULL, 0) != 0)
984		err = dsp->dsa_err;
985
986out:
987	mutex_enter(&to_ds->ds_sendstream_lock);
988	list_remove(&to_ds->ds_sendstreams, dsp);
989	mutex_exit(&to_ds->ds_sendstream_lock);
990
991	VERIFY(err != 0 || (dsp->dsa_sent_begin && dsp->dsa_sent_end));
992
993	kmem_free(drr, sizeof (dmu_replay_record_t));
994	kmem_free(dsp, sizeof (dmu_sendarg_t));
995
996	dsl_dataset_long_rele(to_ds, FTAG);
997
998	return (err);
999}
1000
1001int
1002dmu_send_obj(const char *pool, uint64_t tosnap, uint64_t fromsnap,
1003    boolean_t embedok, boolean_t large_block_ok, boolean_t compressok,
1004#ifdef illumos
1005    int outfd, vnode_t *vp, offset_t *off)
1006#else
1007    int outfd, struct file *fp, offset_t *off)
1008#endif
1009{
1010	dsl_pool_t *dp;
1011	dsl_dataset_t *ds;
1012	dsl_dataset_t *fromds = NULL;
1013	int err;
1014
1015	err = dsl_pool_hold(pool, FTAG, &dp);
1016	if (err != 0)
1017		return (err);
1018
1019	err = dsl_dataset_hold_obj(dp, tosnap, FTAG, &ds);
1020	if (err != 0) {
1021		dsl_pool_rele(dp, FTAG);
1022		return (err);
1023	}
1024
1025	if (fromsnap != 0) {
1026		zfs_bookmark_phys_t zb;
1027		boolean_t is_clone;
1028
1029		err = dsl_dataset_hold_obj(dp, fromsnap, FTAG, &fromds);
1030		if (err != 0) {
1031			dsl_dataset_rele(ds, FTAG);
1032			dsl_pool_rele(dp, FTAG);
1033			return (err);
1034		}
1035		if (!dsl_dataset_is_before(ds, fromds, 0))
1036			err = SET_ERROR(EXDEV);
1037		zb.zbm_creation_time =
1038		    dsl_dataset_phys(fromds)->ds_creation_time;
1039		zb.zbm_creation_txg = dsl_dataset_phys(fromds)->ds_creation_txg;
1040		zb.zbm_guid = dsl_dataset_phys(fromds)->ds_guid;
1041		is_clone = (fromds->ds_dir != ds->ds_dir);
1042		dsl_dataset_rele(fromds, FTAG);
1043		err = dmu_send_impl(FTAG, dp, ds, &zb, is_clone,
1044		    embedok, large_block_ok, compressok, outfd, 0, 0, fp, off);
1045	} else {
1046		err = dmu_send_impl(FTAG, dp, ds, NULL, B_FALSE,
1047		    embedok, large_block_ok, compressok, outfd, 0, 0, fp, off);
1048	}
1049	dsl_dataset_rele(ds, FTAG);
1050	return (err);
1051}
1052
1053int
1054dmu_send(const char *tosnap, const char *fromsnap, boolean_t embedok,
1055    boolean_t large_block_ok, boolean_t compressok, int outfd,
1056    uint64_t resumeobj, uint64_t resumeoff,
1057#ifdef illumos
1058    vnode_t *vp, offset_t *off)
1059#else
1060    struct file *fp, offset_t *off)
1061#endif
1062{
1063	dsl_pool_t *dp;
1064	dsl_dataset_t *ds;
1065	int err;
1066	boolean_t owned = B_FALSE;
1067
1068	if (fromsnap != NULL && strpbrk(fromsnap, "@#") == NULL)
1069		return (SET_ERROR(EINVAL));
1070
1071	err = dsl_pool_hold(tosnap, FTAG, &dp);
1072	if (err != 0)
1073		return (err);
1074
1075	if (strchr(tosnap, '@') == NULL && spa_writeable(dp->dp_spa)) {
1076		/*
1077		 * We are sending a filesystem or volume.  Ensure
1078		 * that it doesn't change by owning the dataset.
1079		 */
1080		err = dsl_dataset_own(dp, tosnap, FTAG, &ds);
1081		owned = B_TRUE;
1082	} else {
1083		err = dsl_dataset_hold(dp, tosnap, FTAG, &ds);
1084	}
1085	if (err != 0) {
1086		dsl_pool_rele(dp, FTAG);
1087		return (err);
1088	}
1089
1090	if (fromsnap != NULL) {
1091		zfs_bookmark_phys_t zb;
1092		boolean_t is_clone = B_FALSE;
1093		int fsnamelen = strchr(tosnap, '@') - tosnap;
1094
1095		/*
1096		 * If the fromsnap is in a different filesystem, then
1097		 * mark the send stream as a clone.
1098		 */
1099		if (strncmp(tosnap, fromsnap, fsnamelen) != 0 ||
1100		    (fromsnap[fsnamelen] != '@' &&
1101		    fromsnap[fsnamelen] != '#')) {
1102			is_clone = B_TRUE;
1103		}
1104
1105		if (strchr(fromsnap, '@')) {
1106			dsl_dataset_t *fromds;
1107			err = dsl_dataset_hold(dp, fromsnap, FTAG, &fromds);
1108			if (err == 0) {
1109				if (!dsl_dataset_is_before(ds, fromds, 0))
1110					err = SET_ERROR(EXDEV);
1111				zb.zbm_creation_time =
1112				    dsl_dataset_phys(fromds)->ds_creation_time;
1113				zb.zbm_creation_txg =
1114				    dsl_dataset_phys(fromds)->ds_creation_txg;
1115				zb.zbm_guid = dsl_dataset_phys(fromds)->ds_guid;
1116				is_clone = (ds->ds_dir != fromds->ds_dir);
1117				dsl_dataset_rele(fromds, FTAG);
1118			}
1119		} else {
1120			err = dsl_bookmark_lookup(dp, fromsnap, ds, &zb);
1121		}
1122		if (err != 0) {
1123			dsl_dataset_rele(ds, FTAG);
1124			dsl_pool_rele(dp, FTAG);
1125			return (err);
1126		}
1127		err = dmu_send_impl(FTAG, dp, ds, &zb, is_clone,
1128		    embedok, large_block_ok, compressok,
1129		    outfd, resumeobj, resumeoff, fp, off);
1130	} else {
1131		err = dmu_send_impl(FTAG, dp, ds, NULL, B_FALSE,
1132		    embedok, large_block_ok, compressok,
1133		    outfd, resumeobj, resumeoff, fp, off);
1134	}
1135	if (owned)
1136		dsl_dataset_disown(ds, FTAG);
1137	else
1138		dsl_dataset_rele(ds, FTAG);
1139	return (err);
1140}
1141
1142static int
1143dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t uncompressed,
1144    uint64_t compressed, boolean_t stream_compressed, uint64_t *sizep)
1145{
1146	int err = 0;
1147	uint64_t size;
1148	/*
1149	 * Assume that space (both on-disk and in-stream) is dominated by
1150	 * data.  We will adjust for indirect blocks and the copies property,
1151	 * but ignore per-object space used (eg, dnodes and DRR_OBJECT records).
1152	 */
1153	uint64_t recordsize;
1154	uint64_t record_count;
1155	objset_t *os;
1156	VERIFY0(dmu_objset_from_ds(ds, &os));
1157
1158	/* Assume all (uncompressed) blocks are recordsize. */
1159	if (zfs_override_estimate_recordsize != 0) {
1160		recordsize = zfs_override_estimate_recordsize;
1161	} else if (os->os_phys->os_type == DMU_OST_ZVOL) {
1162		err = dsl_prop_get_int_ds(ds,
1163		    zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &recordsize);
1164	} else {
1165		err = dsl_prop_get_int_ds(ds,
1166		    zfs_prop_to_name(ZFS_PROP_RECORDSIZE), &recordsize);
1167	}
1168	if (err != 0)
1169		return (err);
1170	record_count = uncompressed / recordsize;
1171
1172	/*
1173	 * If we're estimating a send size for a compressed stream, use the
1174	 * compressed data size to estimate the stream size. Otherwise, use the
1175	 * uncompressed data size.
1176	 */
1177	size = stream_compressed ? compressed : uncompressed;
1178
1179	/*
1180	 * Subtract out approximate space used by indirect blocks.
1181	 * Assume most space is used by data blocks (non-indirect, non-dnode).
1182	 * Assume no ditto blocks or internal fragmentation.
1183	 *
1184	 * Therefore, space used by indirect blocks is sizeof(blkptr_t) per
1185	 * block.
1186	 */
1187	size -= record_count * sizeof (blkptr_t);
1188
1189	/* Add in the space for the record associated with each block. */
1190	size += record_count * sizeof (dmu_replay_record_t);
1191
1192	*sizep = size;
1193
1194	return (0);
1195}
1196
1197int
1198dmu_send_estimate(dsl_dataset_t *ds, dsl_dataset_t *fromds,
1199    boolean_t stream_compressed, uint64_t *sizep)
1200{
1201	dsl_pool_t *dp = ds->ds_dir->dd_pool;
1202	int err;
1203	uint64_t uncomp, comp;
1204
1205	ASSERT(dsl_pool_config_held(dp));
1206
1207	/* tosnap must be a snapshot */
1208	if (!ds->ds_is_snapshot)
1209		return (SET_ERROR(EINVAL));
1210
1211	/* fromsnap, if provided, must be a snapshot */
1212	if (fromds != NULL && !fromds->ds_is_snapshot)
1213		return (SET_ERROR(EINVAL));
1214
1215	/*
1216	 * fromsnap must be an earlier snapshot from the same fs as tosnap,
1217	 * or the origin's fs.
1218	 */
1219	if (fromds != NULL && !dsl_dataset_is_before(ds, fromds, 0))
1220		return (SET_ERROR(EXDEV));
1221
1222	/* Get compressed and uncompressed size estimates of changed data. */
1223	if (fromds == NULL) {
1224		uncomp = dsl_dataset_phys(ds)->ds_uncompressed_bytes;
1225		comp = dsl_dataset_phys(ds)->ds_compressed_bytes;
1226	} else {
1227		uint64_t used;
1228		err = dsl_dataset_space_written(fromds, ds,
1229		    &used, &comp, &uncomp);
1230		if (err != 0)
1231			return (err);
1232	}
1233
1234	err = dmu_adjust_send_estimate_for_indirects(ds, uncomp, comp,
1235	    stream_compressed, sizep);
1236	/*
1237	 * Add the size of the BEGIN and END records to the estimate.
1238	 */
1239	*sizep += 2 * sizeof (dmu_replay_record_t);
1240	return (err);
1241}
1242
1243struct calculate_send_arg {
1244	uint64_t uncompressed;
1245	uint64_t compressed;
1246};
1247
1248/*
1249 * Simple callback used to traverse the blocks of a snapshot and sum their
1250 * uncompressed and compressed sizes.
1251 */
1252/* ARGSUSED */
1253static int
1254dmu_calculate_send_traversal(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1255    const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
1256{
1257	struct calculate_send_arg *space = arg;
1258	if (bp != NULL && !BP_IS_HOLE(bp)) {
1259		space->uncompressed += BP_GET_UCSIZE(bp);
1260		space->compressed += BP_GET_PSIZE(bp);
1261	}
1262	return (0);
1263}
1264
1265/*
1266 * Given a desination snapshot and a TXG, calculate the approximate size of a
1267 * send stream sent from that TXG. from_txg may be zero, indicating that the
1268 * whole snapshot will be sent.
1269 */
1270int
1271dmu_send_estimate_from_txg(dsl_dataset_t *ds, uint64_t from_txg,
1272    boolean_t stream_compressed, uint64_t *sizep)
1273{
1274	dsl_pool_t *dp = ds->ds_dir->dd_pool;
1275	int err;
1276	struct calculate_send_arg size = { 0 };
1277
1278	ASSERT(dsl_pool_config_held(dp));
1279
1280	/* tosnap must be a snapshot */
1281	if (!ds->ds_is_snapshot)
1282		return (SET_ERROR(EINVAL));
1283
1284	/* verify that from_txg is before the provided snapshot was taken */
1285	if (from_txg >= dsl_dataset_phys(ds)->ds_creation_txg) {
1286		return (SET_ERROR(EXDEV));
1287	}
1288
1289	/*
1290	 * traverse the blocks of the snapshot with birth times after
1291	 * from_txg, summing their uncompressed size
1292	 */
1293	err = traverse_dataset(ds, from_txg, TRAVERSE_POST,
1294	    dmu_calculate_send_traversal, &size);
1295	if (err)
1296		return (err);
1297
1298	err = dmu_adjust_send_estimate_for_indirects(ds, size.uncompressed,
1299	    size.compressed, stream_compressed, sizep);
1300	return (err);
1301}
1302
1303typedef struct dmu_recv_begin_arg {
1304	const char *drba_origin;
1305	dmu_recv_cookie_t *drba_cookie;
1306	cred_t *drba_cred;
1307	uint64_t drba_snapobj;
1308} dmu_recv_begin_arg_t;
1309
1310static int
1311recv_begin_check_existing_impl(dmu_recv_begin_arg_t *drba, dsl_dataset_t *ds,
1312    uint64_t fromguid)
1313{
1314	uint64_t val;
1315	uint64_t children;
1316	int error;
1317	dsl_pool_t *dp = ds->ds_dir->dd_pool;
1318
1319	/* Temporary clone name must not exist. */
1320	error = zap_lookup(dp->dp_meta_objset,
1321	    dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, recv_clone_name,
1322	    8, 1, &val);
1323	if (error != ENOENT)
1324		return (error == 0 ? SET_ERROR(EBUSY) : error);
1325
1326	/* Resume state must not be set. */
1327	if (dsl_dataset_has_resume_receive_state(ds))
1328		return (SET_ERROR(EBUSY));
1329
1330	/* New snapshot name must not exist. */
1331	error = zap_lookup(dp->dp_meta_objset,
1332	    dsl_dataset_phys(ds)->ds_snapnames_zapobj,
1333	    drba->drba_cookie->drc_tosnap, 8, 1, &val);
1334	if (error != ENOENT)
1335		return (error == 0 ? SET_ERROR(EEXIST) : error);
1336
1337	/* must not have children if receiving a ZVOL */
1338	error = zap_count(dp->dp_meta_objset,
1339	    dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, &children);
1340	if (error != 0)
1341		return (error);
1342	if (drba->drba_cookie->drc_drrb->drr_type != DMU_OST_ZFS &&
1343	    children > 0)
1344		return (SET_ERROR(ZFS_ERR_WRONG_PARENT));
1345
1346	/*
1347	 * Check snapshot limit before receiving. We'll recheck again at the
1348	 * end, but might as well abort before receiving if we're already over
1349	 * the limit.
1350	 *
1351	 * Note that we do not check the file system limit with
1352	 * dsl_dir_fscount_check because the temporary %clones don't count
1353	 * against that limit.
1354	 */
1355	error = dsl_fs_ss_limit_check(ds->ds_dir, 1, ZFS_PROP_SNAPSHOT_LIMIT,
1356	    NULL, drba->drba_cred);
1357	if (error != 0)
1358		return (error);
1359
1360	if (fromguid != 0) {
1361		dsl_dataset_t *snap;
1362		uint64_t obj = dsl_dataset_phys(ds)->ds_prev_snap_obj;
1363
1364		/* Find snapshot in this dir that matches fromguid. */
1365		while (obj != 0) {
1366			error = dsl_dataset_hold_obj(dp, obj, FTAG,
1367			    &snap);
1368			if (error != 0)
1369				return (SET_ERROR(ENODEV));
1370			if (snap->ds_dir != ds->ds_dir) {
1371				dsl_dataset_rele(snap, FTAG);
1372				return (SET_ERROR(ENODEV));
1373			}
1374			if (dsl_dataset_phys(snap)->ds_guid == fromguid)
1375				break;
1376			obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
1377			dsl_dataset_rele(snap, FTAG);
1378		}
1379		if (obj == 0)
1380			return (SET_ERROR(ENODEV));
1381
1382		if (drba->drba_cookie->drc_force) {
1383			drba->drba_snapobj = obj;
1384		} else {
1385			/*
1386			 * If we are not forcing, there must be no
1387			 * changes since fromsnap.
1388			 */
1389			if (dsl_dataset_modified_since_snap(ds, snap)) {
1390				dsl_dataset_rele(snap, FTAG);
1391				return (SET_ERROR(ETXTBSY));
1392			}
1393			drba->drba_snapobj = ds->ds_prev->ds_object;
1394		}
1395
1396		dsl_dataset_rele(snap, FTAG);
1397	} else {
1398		/* if full, then must be forced */
1399		if (!drba->drba_cookie->drc_force)
1400			return (SET_ERROR(EEXIST));
1401		/* start from $ORIGIN@$ORIGIN, if supported */
1402		drba->drba_snapobj = dp->dp_origin_snap != NULL ?
1403		    dp->dp_origin_snap->ds_object : 0;
1404	}
1405
1406	return (0);
1407
1408}
1409
1410static int
1411dmu_recv_begin_check(void *arg, dmu_tx_t *tx)
1412{
1413	dmu_recv_begin_arg_t *drba = arg;
1414	dsl_pool_t *dp = dmu_tx_pool(tx);
1415	struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
1416	uint64_t fromguid = drrb->drr_fromguid;
1417	int flags = drrb->drr_flags;
1418	int error;
1419	uint64_t featureflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
1420	dsl_dataset_t *ds;
1421	const char *tofs = drba->drba_cookie->drc_tofs;
1422
1423	/* already checked */
1424	ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
1425	ASSERT(!(featureflags & DMU_BACKUP_FEATURE_RESUMING));
1426
1427	if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
1428	    DMU_COMPOUNDSTREAM ||
1429	    drrb->drr_type >= DMU_OST_NUMTYPES ||
1430	    ((flags & DRR_FLAG_CLONE) && drba->drba_origin == NULL))
1431		return (SET_ERROR(EINVAL));
1432
1433	/* Verify pool version supports SA if SA_SPILL feature set */
1434	if ((featureflags & DMU_BACKUP_FEATURE_SA_SPILL) &&
1435	    spa_version(dp->dp_spa) < SPA_VERSION_SA)
1436		return (SET_ERROR(ENOTSUP));
1437
1438	if (drba->drba_cookie->drc_resumable &&
1439	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EXTENSIBLE_DATASET))
1440		return (SET_ERROR(ENOTSUP));
1441
1442	/*
1443	 * The receiving code doesn't know how to translate a WRITE_EMBEDDED
1444	 * record to a plain WRITE record, so the pool must have the
1445	 * EMBEDDED_DATA feature enabled if the stream has WRITE_EMBEDDED
1446	 * records.  Same with WRITE_EMBEDDED records that use LZ4 compression.
1447	 */
1448	if ((featureflags & DMU_BACKUP_FEATURE_EMBED_DATA) &&
1449	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA))
1450		return (SET_ERROR(ENOTSUP));
1451	if ((featureflags & DMU_BACKUP_FEATURE_LZ4) &&
1452	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
1453		return (SET_ERROR(ENOTSUP));
1454
1455	/*
1456	 * The receiving code doesn't know how to translate large blocks
1457	 * to smaller ones, so the pool must have the LARGE_BLOCKS
1458	 * feature enabled if the stream has LARGE_BLOCKS. Same with
1459	 * large dnodes.
1460	 */
1461	if ((featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
1462	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS))
1463		return (SET_ERROR(ENOTSUP));
1464	if ((featureflags & DMU_BACKUP_FEATURE_LARGE_DNODE) &&
1465	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LARGE_DNODE))
1466		return (SET_ERROR(ENOTSUP));
1467
1468	error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
1469	if (error == 0) {
1470		/* target fs already exists; recv into temp clone */
1471
1472		/* Can't recv a clone into an existing fs */
1473		if (flags & DRR_FLAG_CLONE || drba->drba_origin) {
1474			dsl_dataset_rele(ds, FTAG);
1475			return (SET_ERROR(EINVAL));
1476		}
1477
1478		error = recv_begin_check_existing_impl(drba, ds, fromguid);
1479		dsl_dataset_rele(ds, FTAG);
1480	} else if (error == ENOENT) {
1481		/* target fs does not exist; must be a full backup or clone */
1482		char buf[ZFS_MAX_DATASET_NAME_LEN];
1483		objset_t *os;
1484
1485		/*
1486		 * If it's a non-clone incremental, we are missing the
1487		 * target fs, so fail the recv.
1488		 */
1489		if (fromguid != 0 && !(flags & DRR_FLAG_CLONE ||
1490		    drba->drba_origin))
1491			return (SET_ERROR(ENOENT));
1492
1493		/*
1494		 * If we're receiving a full send as a clone, and it doesn't
1495		 * contain all the necessary free records and freeobject
1496		 * records, reject it.
1497		 */
1498		if (fromguid == 0 && drba->drba_origin &&
1499		    !(flags & DRR_FLAG_FREERECORDS))
1500			return (SET_ERROR(EINVAL));
1501
1502		/* Open the parent of tofs */
1503		ASSERT3U(strlen(tofs), <, sizeof (buf));
1504		(void) strlcpy(buf, tofs, strrchr(tofs, '/') - tofs + 1);
1505		error = dsl_dataset_hold(dp, buf, FTAG, &ds);
1506		if (error != 0)
1507			return (error);
1508
1509		/*
1510		 * Check filesystem and snapshot limits before receiving. We'll
1511		 * recheck snapshot limits again at the end (we create the
1512		 * filesystems and increment those counts during begin_sync).
1513		 */
1514		error = dsl_fs_ss_limit_check(ds->ds_dir, 1,
1515		    ZFS_PROP_FILESYSTEM_LIMIT, NULL, drba->drba_cred);
1516		if (error != 0) {
1517			dsl_dataset_rele(ds, FTAG);
1518			return (error);
1519		}
1520
1521		error = dsl_fs_ss_limit_check(ds->ds_dir, 1,
1522		    ZFS_PROP_SNAPSHOT_LIMIT, NULL, drba->drba_cred);
1523		if (error != 0) {
1524			dsl_dataset_rele(ds, FTAG);
1525			return (error);
1526		}
1527
1528		/* can't recv below anything but filesystems (eg. no ZVOLs) */
1529		error = dmu_objset_from_ds(ds, &os);
1530		if (error != 0) {
1531			dsl_dataset_rele(ds, FTAG);
1532			return (error);
1533		}
1534		if (dmu_objset_type(os) != DMU_OST_ZFS) {
1535			dsl_dataset_rele(ds, FTAG);
1536			return (SET_ERROR(ZFS_ERR_WRONG_PARENT));
1537		}
1538
1539		if (drba->drba_origin != NULL) {
1540			dsl_dataset_t *origin;
1541			error = dsl_dataset_hold(dp, drba->drba_origin,
1542			    FTAG, &origin);
1543			if (error != 0) {
1544				dsl_dataset_rele(ds, FTAG);
1545				return (error);
1546			}
1547			if (!origin->ds_is_snapshot) {
1548				dsl_dataset_rele(origin, FTAG);
1549				dsl_dataset_rele(ds, FTAG);
1550				return (SET_ERROR(EINVAL));
1551			}
1552			if (dsl_dataset_phys(origin)->ds_guid != fromguid &&
1553			    fromguid != 0) {
1554				dsl_dataset_rele(origin, FTAG);
1555				dsl_dataset_rele(ds, FTAG);
1556				return (SET_ERROR(ENODEV));
1557			}
1558			dsl_dataset_rele(origin, FTAG);
1559		}
1560
1561		dsl_dataset_rele(ds, FTAG);
1562		error = 0;
1563	}
1564	return (error);
1565}
1566
1567static void
1568dmu_recv_begin_sync(void *arg, dmu_tx_t *tx)
1569{
1570	dmu_recv_begin_arg_t *drba = arg;
1571	dsl_pool_t *dp = dmu_tx_pool(tx);
1572	objset_t *mos = dp->dp_meta_objset;
1573	struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
1574	const char *tofs = drba->drba_cookie->drc_tofs;
1575	dsl_dataset_t *ds, *newds;
1576	uint64_t dsobj;
1577	int error;
1578	uint64_t crflags = 0;
1579
1580	if (drrb->drr_flags & DRR_FLAG_CI_DATA)
1581		crflags |= DS_FLAG_CI_DATASET;
1582
1583	error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
1584	if (error == 0) {
1585		/* create temporary clone */
1586		dsl_dataset_t *snap = NULL;
1587		if (drba->drba_snapobj != 0) {
1588			VERIFY0(dsl_dataset_hold_obj(dp,
1589			    drba->drba_snapobj, FTAG, &snap));
1590		}
1591		dsobj = dsl_dataset_create_sync(ds->ds_dir, recv_clone_name,
1592		    snap, crflags, drba->drba_cred, tx);
1593		if (drba->drba_snapobj != 0)
1594			dsl_dataset_rele(snap, FTAG);
1595		dsl_dataset_rele(ds, FTAG);
1596	} else {
1597		dsl_dir_t *dd;
1598		const char *tail;
1599		dsl_dataset_t *origin = NULL;
1600
1601		VERIFY0(dsl_dir_hold(dp, tofs, FTAG, &dd, &tail));
1602
1603		if (drba->drba_origin != NULL) {
1604			VERIFY0(dsl_dataset_hold(dp, drba->drba_origin,
1605			    FTAG, &origin));
1606		}
1607
1608		/* Create new dataset. */
1609		dsobj = dsl_dataset_create_sync(dd,
1610		    strrchr(tofs, '/') + 1,
1611		    origin, crflags, drba->drba_cred, tx);
1612		if (origin != NULL)
1613			dsl_dataset_rele(origin, FTAG);
1614		dsl_dir_rele(dd, FTAG);
1615		drba->drba_cookie->drc_newfs = B_TRUE;
1616	}
1617	VERIFY0(dsl_dataset_own_obj(dp, dsobj, dmu_recv_tag, &newds));
1618
1619	if (drba->drba_cookie->drc_resumable) {
1620		dsl_dataset_zapify(newds, tx);
1621		if (drrb->drr_fromguid != 0) {
1622			VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_FROMGUID,
1623			    8, 1, &drrb->drr_fromguid, tx));
1624		}
1625		VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_TOGUID,
1626		    8, 1, &drrb->drr_toguid, tx));
1627		VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_TONAME,
1628		    1, strlen(drrb->drr_toname) + 1, drrb->drr_toname, tx));
1629		uint64_t one = 1;
1630		uint64_t zero = 0;
1631		VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_OBJECT,
1632		    8, 1, &one, tx));
1633		VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_OFFSET,
1634		    8, 1, &zero, tx));
1635		VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_BYTES,
1636		    8, 1, &zero, tx));
1637		if (DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
1638		    DMU_BACKUP_FEATURE_LARGE_BLOCKS) {
1639			VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_LARGEBLOCK,
1640			    8, 1, &one, tx));
1641		}
1642		if (DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
1643		    DMU_BACKUP_FEATURE_EMBED_DATA) {
1644			VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_EMBEDOK,
1645			    8, 1, &one, tx));
1646		}
1647		if (DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
1648		    DMU_BACKUP_FEATURE_COMPRESSED) {
1649			VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_COMPRESSOK,
1650			    8, 1, &one, tx));
1651		}
1652	}
1653
1654	dmu_buf_will_dirty(newds->ds_dbuf, tx);
1655	dsl_dataset_phys(newds)->ds_flags |= DS_FLAG_INCONSISTENT;
1656
1657	/*
1658	 * If we actually created a non-clone, we need to create the
1659	 * objset in our new dataset.
1660	 */
1661	rrw_enter(&newds->ds_bp_rwlock, RW_READER, FTAG);
1662	if (BP_IS_HOLE(dsl_dataset_get_blkptr(newds))) {
1663		(void) dmu_objset_create_impl(dp->dp_spa,
1664		    newds, dsl_dataset_get_blkptr(newds), drrb->drr_type, tx);
1665	}
1666	rrw_exit(&newds->ds_bp_rwlock, FTAG);
1667
1668	drba->drba_cookie->drc_ds = newds;
1669
1670	spa_history_log_internal_ds(newds, "receive", tx, "");
1671}
1672
1673static int
1674dmu_recv_resume_begin_check(void *arg, dmu_tx_t *tx)
1675{
1676	dmu_recv_begin_arg_t *drba = arg;
1677	dsl_pool_t *dp = dmu_tx_pool(tx);
1678	struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
1679	int error;
1680	uint64_t featureflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
1681	dsl_dataset_t *ds;
1682	const char *tofs = drba->drba_cookie->drc_tofs;
1683
1684	/* 6 extra bytes for /%recv */
1685	char recvname[ZFS_MAX_DATASET_NAME_LEN + 6];
1686
1687	/* already checked */
1688	ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
1689	ASSERT(featureflags & DMU_BACKUP_FEATURE_RESUMING);
1690
1691	if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
1692	    DMU_COMPOUNDSTREAM ||
1693	    drrb->drr_type >= DMU_OST_NUMTYPES)
1694		return (SET_ERROR(EINVAL));
1695
1696	/* Verify pool version supports SA if SA_SPILL feature set */
1697	if ((featureflags & DMU_BACKUP_FEATURE_SA_SPILL) &&
1698	    spa_version(dp->dp_spa) < SPA_VERSION_SA)
1699		return (SET_ERROR(ENOTSUP));
1700
1701	/*
1702	 * The receiving code doesn't know how to translate a WRITE_EMBEDDED
1703	 * record to a plain WRITE record, so the pool must have the
1704	 * EMBEDDED_DATA feature enabled if the stream has WRITE_EMBEDDED
1705	 * records.  Same with WRITE_EMBEDDED records that use LZ4 compression.
1706	 */
1707	if ((featureflags & DMU_BACKUP_FEATURE_EMBED_DATA) &&
1708	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA))
1709		return (SET_ERROR(ENOTSUP));
1710	if ((featureflags & DMU_BACKUP_FEATURE_LZ4) &&
1711	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
1712		return (SET_ERROR(ENOTSUP));
1713
1714	/*
1715	 * The receiving code doesn't know how to translate large blocks
1716	 * to smaller ones, so the pool must have the LARGE_BLOCKS
1717	 * feature enabled if the stream has LARGE_BLOCKS. Same with
1718	 * large dnodes.
1719	 */
1720	if ((featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
1721	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS))
1722		return (SET_ERROR(ENOTSUP));
1723	if ((featureflags & DMU_BACKUP_FEATURE_LARGE_DNODE) &&
1724	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LARGE_DNODE))
1725		return (SET_ERROR(ENOTSUP));
1726
1727	(void) snprintf(recvname, sizeof (recvname), "%s/%s",
1728	    tofs, recv_clone_name);
1729
1730	if (dsl_dataset_hold(dp, recvname, FTAG, &ds) != 0) {
1731		/* %recv does not exist; continue in tofs */
1732		error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
1733		if (error != 0)
1734			return (error);
1735	}
1736
1737	/* check that ds is marked inconsistent */
1738	if (!DS_IS_INCONSISTENT(ds)) {
1739		dsl_dataset_rele(ds, FTAG);
1740		return (SET_ERROR(EINVAL));
1741	}
1742
1743	/* check that there is resuming data, and that the toguid matches */
1744	if (!dsl_dataset_is_zapified(ds)) {
1745		dsl_dataset_rele(ds, FTAG);
1746		return (SET_ERROR(EINVAL));
1747	}
1748	uint64_t val;
1749	error = zap_lookup(dp->dp_meta_objset, ds->ds_object,
1750	    DS_FIELD_RESUME_TOGUID, sizeof (val), 1, &val);
1751	if (error != 0 || drrb->drr_toguid != val) {
1752		dsl_dataset_rele(ds, FTAG);
1753		return (SET_ERROR(EINVAL));
1754	}
1755
1756	/*
1757	 * Check if the receive is still running.  If so, it will be owned.
1758	 * Note that nothing else can own the dataset (e.g. after the receive
1759	 * fails) because it will be marked inconsistent.
1760	 */
1761	if (dsl_dataset_has_owner(ds)) {
1762		dsl_dataset_rele(ds, FTAG);
1763		return (SET_ERROR(EBUSY));
1764	}
1765
1766	/* There should not be any snapshots of this fs yet. */
1767	if (ds->ds_prev != NULL && ds->ds_prev->ds_dir == ds->ds_dir) {
1768		dsl_dataset_rele(ds, FTAG);
1769		return (SET_ERROR(EINVAL));
1770	}
1771
1772	/*
1773	 * Note: resume point will be checked when we process the first WRITE
1774	 * record.
1775	 */
1776
1777	/* check that the origin matches */
1778	val = 0;
1779	(void) zap_lookup(dp->dp_meta_objset, ds->ds_object,
1780	    DS_FIELD_RESUME_FROMGUID, sizeof (val), 1, &val);
1781	if (drrb->drr_fromguid != val) {
1782		dsl_dataset_rele(ds, FTAG);
1783		return (SET_ERROR(EINVAL));
1784	}
1785
1786	dsl_dataset_rele(ds, FTAG);
1787	return (0);
1788}
1789
1790static void
1791dmu_recv_resume_begin_sync(void *arg, dmu_tx_t *tx)
1792{
1793	dmu_recv_begin_arg_t *drba = arg;
1794	dsl_pool_t *dp = dmu_tx_pool(tx);
1795	const char *tofs = drba->drba_cookie->drc_tofs;
1796	dsl_dataset_t *ds;
1797	uint64_t dsobj;
1798	/* 6 extra bytes for /%recv */
1799	char recvname[ZFS_MAX_DATASET_NAME_LEN + 6];
1800
1801	(void) snprintf(recvname, sizeof (recvname), "%s/%s",
1802	    tofs, recv_clone_name);
1803
1804	if (dsl_dataset_hold(dp, recvname, FTAG, &ds) != 0) {
1805		/* %recv does not exist; continue in tofs */
1806		VERIFY0(dsl_dataset_hold(dp, tofs, FTAG, &ds));
1807		drba->drba_cookie->drc_newfs = B_TRUE;
1808	}
1809
1810	/* clear the inconsistent flag so that we can own it */
1811	ASSERT(DS_IS_INCONSISTENT(ds));
1812	dmu_buf_will_dirty(ds->ds_dbuf, tx);
1813	dsl_dataset_phys(ds)->ds_flags &= ~DS_FLAG_INCONSISTENT;
1814	dsobj = ds->ds_object;
1815	dsl_dataset_rele(ds, FTAG);
1816
1817	VERIFY0(dsl_dataset_own_obj(dp, dsobj, dmu_recv_tag, &ds));
1818
1819	dmu_buf_will_dirty(ds->ds_dbuf, tx);
1820	dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_INCONSISTENT;
1821
1822	rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
1823	ASSERT(!BP_IS_HOLE(dsl_dataset_get_blkptr(ds)));
1824	rrw_exit(&ds->ds_bp_rwlock, FTAG);
1825
1826	drba->drba_cookie->drc_ds = ds;
1827
1828	spa_history_log_internal_ds(ds, "resume receive", tx, "");
1829}
1830
1831/*
1832 * NB: callers *MUST* call dmu_recv_stream() if dmu_recv_begin()
1833 * succeeds; otherwise we will leak the holds on the datasets.
1834 */
1835int
1836dmu_recv_begin(char *tofs, char *tosnap, dmu_replay_record_t *drr_begin,
1837    boolean_t force, boolean_t resumable, char *origin, dmu_recv_cookie_t *drc)
1838{
1839	dmu_recv_begin_arg_t drba = { 0 };
1840
1841	bzero(drc, sizeof (dmu_recv_cookie_t));
1842	drc->drc_drr_begin = drr_begin;
1843	drc->drc_drrb = &drr_begin->drr_u.drr_begin;
1844	drc->drc_tosnap = tosnap;
1845	drc->drc_tofs = tofs;
1846	drc->drc_force = force;
1847	drc->drc_resumable = resumable;
1848	drc->drc_cred = CRED();
1849	drc->drc_clone = (origin != NULL);
1850
1851	if (drc->drc_drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC)) {
1852		drc->drc_byteswap = B_TRUE;
1853		(void) fletcher_4_incremental_byteswap(drr_begin,
1854		    sizeof (dmu_replay_record_t), &drc->drc_cksum);
1855		byteswap_record(drr_begin);
1856	} else if (drc->drc_drrb->drr_magic == DMU_BACKUP_MAGIC) {
1857		(void) fletcher_4_incremental_native(drr_begin,
1858		    sizeof (dmu_replay_record_t), &drc->drc_cksum);
1859	} else {
1860		return (SET_ERROR(EINVAL));
1861	}
1862
1863	drba.drba_origin = origin;
1864	drba.drba_cookie = drc;
1865	drba.drba_cred = CRED();
1866
1867	if (DMU_GET_FEATUREFLAGS(drc->drc_drrb->drr_versioninfo) &
1868	    DMU_BACKUP_FEATURE_RESUMING) {
1869		return (dsl_sync_task(tofs,
1870		    dmu_recv_resume_begin_check, dmu_recv_resume_begin_sync,
1871		    &drba, 5, ZFS_SPACE_CHECK_NORMAL));
1872	} else  {
1873		return (dsl_sync_task(tofs,
1874		    dmu_recv_begin_check, dmu_recv_begin_sync,
1875		    &drba, 5, ZFS_SPACE_CHECK_NORMAL));
1876	}
1877}
1878
1879struct receive_record_arg {
1880	dmu_replay_record_t header;
1881	void *payload; /* Pointer to a buffer containing the payload */
1882	/*
1883	 * If the record is a write, pointer to the arc_buf_t containing the
1884	 * payload.
1885	 */
1886	arc_buf_t *write_buf;
1887	int payload_size;
1888	uint64_t bytes_read; /* bytes read from stream when record created */
1889	boolean_t eos_marker; /* Marks the end of the stream */
1890	bqueue_node_t node;
1891};
1892
1893struct receive_writer_arg {
1894	objset_t *os;
1895	boolean_t byteswap;
1896	bqueue_t q;
1897
1898	/*
1899	 * These three args are used to signal to the main thread that we're
1900	 * done.
1901	 */
1902	kmutex_t mutex;
1903	kcondvar_t cv;
1904	boolean_t done;
1905
1906	int err;
1907	/* A map from guid to dataset to help handle dedup'd streams. */
1908	avl_tree_t *guid_to_ds_map;
1909	boolean_t resumable;
1910	uint64_t last_object;
1911	uint64_t last_offset;
1912	uint64_t max_object; /* highest object ID referenced in stream */
1913	uint64_t bytes_read; /* bytes read when current record created */
1914};
1915
1916struct objlist {
1917	list_t list; /* List of struct receive_objnode. */
1918	/*
1919	 * Last object looked up. Used to assert that objects are being looked
1920	 * up in ascending order.
1921	 */
1922	uint64_t last_lookup;
1923};
1924
1925struct receive_objnode {
1926	list_node_t node;
1927	uint64_t object;
1928};
1929
1930struct receive_arg {
1931	objset_t *os;
1932	kthread_t *td;
1933	struct file *fp;
1934	uint64_t voff; /* The current offset in the stream */
1935	uint64_t bytes_read;
1936	/*
1937	 * A record that has had its payload read in, but hasn't yet been handed
1938	 * off to the worker thread.
1939	 */
1940	struct receive_record_arg *rrd;
1941	/* A record that has had its header read in, but not its payload. */
1942	struct receive_record_arg *next_rrd;
1943	zio_cksum_t cksum;
1944	zio_cksum_t prev_cksum;
1945	int err;
1946	boolean_t byteswap;
1947	/* Sorted list of objects not to issue prefetches for. */
1948	struct objlist ignore_objlist;
1949};
1950
1951typedef struct guid_map_entry {
1952	uint64_t	guid;
1953	dsl_dataset_t	*gme_ds;
1954	avl_node_t	avlnode;
1955} guid_map_entry_t;
1956
1957static int
1958guid_compare(const void *arg1, const void *arg2)
1959{
1960	const guid_map_entry_t *gmep1 = (const guid_map_entry_t *)arg1;
1961	const guid_map_entry_t *gmep2 = (const guid_map_entry_t *)arg2;
1962
1963	return (AVL_CMP(gmep1->guid, gmep2->guid));
1964}
1965
1966static void
1967free_guid_map_onexit(void *arg)
1968{
1969	avl_tree_t *ca = arg;
1970	void *cookie = NULL;
1971	guid_map_entry_t *gmep;
1972
1973	while ((gmep = avl_destroy_nodes(ca, &cookie)) != NULL) {
1974		dsl_dataset_long_rele(gmep->gme_ds, gmep);
1975		dsl_dataset_rele(gmep->gme_ds, gmep);
1976		kmem_free(gmep, sizeof (guid_map_entry_t));
1977	}
1978	avl_destroy(ca);
1979	kmem_free(ca, sizeof (avl_tree_t));
1980}
1981
1982static int
1983restore_bytes(struct receive_arg *ra, void *buf, int len, off_t off, ssize_t *resid)
1984{
1985	struct uio auio;
1986	struct iovec aiov;
1987	int error;
1988
1989	aiov.iov_base = buf;
1990	aiov.iov_len = len;
1991	auio.uio_iov = &aiov;
1992	auio.uio_iovcnt = 1;
1993	auio.uio_resid = len;
1994	auio.uio_segflg = UIO_SYSSPACE;
1995	auio.uio_rw = UIO_READ;
1996	auio.uio_offset = off;
1997	auio.uio_td = ra->td;
1998#ifdef _KERNEL
1999	error = fo_read(ra->fp, &auio, ra->td->td_ucred, FOF_OFFSET, ra->td);
2000#else
2001	fprintf(stderr, "%s: returning EOPNOTSUPP\n", __func__);
2002	error = EOPNOTSUPP;
2003#endif
2004	*resid = auio.uio_resid;
2005	return (error);
2006}
2007
2008static int
2009receive_read(struct receive_arg *ra, int len, void *buf)
2010{
2011	int done = 0;
2012
2013	/*
2014	 * The code doesn't rely on this (lengths being multiples of 8).  See
2015	 * comment in dump_bytes.
2016	 */
2017	ASSERT0(len % 8);
2018
2019	while (done < len) {
2020		ssize_t resid;
2021
2022		ra->err = restore_bytes(ra, buf + done,
2023		    len - done, ra->voff, &resid);
2024
2025		if (resid == len - done) {
2026			/*
2027			 * Note: ECKSUM indicates that the receive
2028			 * was interrupted and can potentially be resumed.
2029			 */
2030			ra->err = SET_ERROR(ECKSUM);
2031		}
2032		ra->voff += len - done - resid;
2033		done = len - resid;
2034		if (ra->err != 0)
2035			return (ra->err);
2036	}
2037
2038	ra->bytes_read += len;
2039
2040	ASSERT3U(done, ==, len);
2041	return (0);
2042}
2043
2044noinline static void
2045byteswap_record(dmu_replay_record_t *drr)
2046{
2047#define	DO64(X) (drr->drr_u.X = BSWAP_64(drr->drr_u.X))
2048#define	DO32(X) (drr->drr_u.X = BSWAP_32(drr->drr_u.X))
2049	drr->drr_type = BSWAP_32(drr->drr_type);
2050	drr->drr_payloadlen = BSWAP_32(drr->drr_payloadlen);
2051
2052	switch (drr->drr_type) {
2053	case DRR_BEGIN:
2054		DO64(drr_begin.drr_magic);
2055		DO64(drr_begin.drr_versioninfo);
2056		DO64(drr_begin.drr_creation_time);
2057		DO32(drr_begin.drr_type);
2058		DO32(drr_begin.drr_flags);
2059		DO64(drr_begin.drr_toguid);
2060		DO64(drr_begin.drr_fromguid);
2061		break;
2062	case DRR_OBJECT:
2063		DO64(drr_object.drr_object);
2064		DO32(drr_object.drr_type);
2065		DO32(drr_object.drr_bonustype);
2066		DO32(drr_object.drr_blksz);
2067		DO32(drr_object.drr_bonuslen);
2068		DO64(drr_object.drr_toguid);
2069		break;
2070	case DRR_FREEOBJECTS:
2071		DO64(drr_freeobjects.drr_firstobj);
2072		DO64(drr_freeobjects.drr_numobjs);
2073		DO64(drr_freeobjects.drr_toguid);
2074		break;
2075	case DRR_WRITE:
2076		DO64(drr_write.drr_object);
2077		DO32(drr_write.drr_type);
2078		DO64(drr_write.drr_offset);
2079		DO64(drr_write.drr_logical_size);
2080		DO64(drr_write.drr_toguid);
2081		ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_write.drr_key.ddk_cksum);
2082		DO64(drr_write.drr_key.ddk_prop);
2083		DO64(drr_write.drr_compressed_size);
2084		break;
2085	case DRR_WRITE_BYREF:
2086		DO64(drr_write_byref.drr_object);
2087		DO64(drr_write_byref.drr_offset);
2088		DO64(drr_write_byref.drr_length);
2089		DO64(drr_write_byref.drr_toguid);
2090		DO64(drr_write_byref.drr_refguid);
2091		DO64(drr_write_byref.drr_refobject);
2092		DO64(drr_write_byref.drr_refoffset);
2093		ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_write_byref.
2094		    drr_key.ddk_cksum);
2095		DO64(drr_write_byref.drr_key.ddk_prop);
2096		break;
2097	case DRR_WRITE_EMBEDDED:
2098		DO64(drr_write_embedded.drr_object);
2099		DO64(drr_write_embedded.drr_offset);
2100		DO64(drr_write_embedded.drr_length);
2101		DO64(drr_write_embedded.drr_toguid);
2102		DO32(drr_write_embedded.drr_lsize);
2103		DO32(drr_write_embedded.drr_psize);
2104		break;
2105	case DRR_FREE:
2106		DO64(drr_free.drr_object);
2107		DO64(drr_free.drr_offset);
2108		DO64(drr_free.drr_length);
2109		DO64(drr_free.drr_toguid);
2110		break;
2111	case DRR_SPILL:
2112		DO64(drr_spill.drr_object);
2113		DO64(drr_spill.drr_length);
2114		DO64(drr_spill.drr_toguid);
2115		break;
2116	case DRR_END:
2117		DO64(drr_end.drr_toguid);
2118		ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_end.drr_checksum);
2119		break;
2120	}
2121
2122	if (drr->drr_type != DRR_BEGIN) {
2123		ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_checksum.drr_checksum);
2124	}
2125
2126#undef DO64
2127#undef DO32
2128}
2129
2130static inline uint8_t
2131deduce_nblkptr(dmu_object_type_t bonus_type, uint64_t bonus_size)
2132{
2133	if (bonus_type == DMU_OT_SA) {
2134		return (1);
2135	} else {
2136		return (1 +
2137		    ((DN_OLD_MAX_BONUSLEN -
2138		    MIN(DN_OLD_MAX_BONUSLEN, bonus_size)) >> SPA_BLKPTRSHIFT));
2139	}
2140}
2141
2142static void
2143save_resume_state(struct receive_writer_arg *rwa,
2144    uint64_t object, uint64_t offset, dmu_tx_t *tx)
2145{
2146	int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
2147
2148	if (!rwa->resumable)
2149		return;
2150
2151	/*
2152	 * We use ds_resume_bytes[] != 0 to indicate that we need to
2153	 * update this on disk, so it must not be 0.
2154	 */
2155	ASSERT(rwa->bytes_read != 0);
2156
2157	/*
2158	 * We only resume from write records, which have a valid
2159	 * (non-meta-dnode) object number.
2160	 */
2161	ASSERT(object != 0);
2162
2163	/*
2164	 * For resuming to work correctly, we must receive records in order,
2165	 * sorted by object,offset.  This is checked by the callers, but
2166	 * assert it here for good measure.
2167	 */
2168	ASSERT3U(object, >=, rwa->os->os_dsl_dataset->ds_resume_object[txgoff]);
2169	ASSERT(object != rwa->os->os_dsl_dataset->ds_resume_object[txgoff] ||
2170	    offset >= rwa->os->os_dsl_dataset->ds_resume_offset[txgoff]);
2171	ASSERT3U(rwa->bytes_read, >=,
2172	    rwa->os->os_dsl_dataset->ds_resume_bytes[txgoff]);
2173
2174	rwa->os->os_dsl_dataset->ds_resume_object[txgoff] = object;
2175	rwa->os->os_dsl_dataset->ds_resume_offset[txgoff] = offset;
2176	rwa->os->os_dsl_dataset->ds_resume_bytes[txgoff] = rwa->bytes_read;
2177}
2178
2179noinline static int
2180receive_object(struct receive_writer_arg *rwa, struct drr_object *drro,
2181    void *data)
2182{
2183	dmu_object_info_t doi;
2184	dmu_tx_t *tx;
2185	uint64_t object;
2186	int err;
2187	uint8_t dn_slots = drro->drr_dn_slots != 0 ?
2188	    drro->drr_dn_slots : DNODE_MIN_SLOTS;
2189
2190	if (drro->drr_type == DMU_OT_NONE ||
2191	    !DMU_OT_IS_VALID(drro->drr_type) ||
2192	    !DMU_OT_IS_VALID(drro->drr_bonustype) ||
2193	    drro->drr_checksumtype >= ZIO_CHECKSUM_FUNCTIONS ||
2194	    drro->drr_compress >= ZIO_COMPRESS_FUNCTIONS ||
2195	    P2PHASE(drro->drr_blksz, SPA_MINBLOCKSIZE) ||
2196	    drro->drr_blksz < SPA_MINBLOCKSIZE ||
2197	    drro->drr_blksz > spa_maxblocksize(dmu_objset_spa(rwa->os)) ||
2198	    drro->drr_bonuslen >
2199	    DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(rwa->os))) ||
2200	    dn_slots >
2201	    (spa_maxdnodesize(dmu_objset_spa(rwa->os)) >> DNODE_SHIFT)) {
2202		return (SET_ERROR(EINVAL));
2203	}
2204
2205	err = dmu_object_info(rwa->os, drro->drr_object, &doi);
2206
2207	if (err != 0 && err != ENOENT && err != EEXIST)
2208		return (SET_ERROR(EINVAL));
2209
2210	if (drro->drr_object > rwa->max_object)
2211		rwa->max_object = drro->drr_object;
2212
2213	/*
2214	 * If we are losing blkptrs or changing the block size this must
2215	 * be a new file instance.  We must clear out the previous file
2216	 * contents before we can change this type of metadata in the dnode.
2217	 */
2218	if (err == 0) {
2219		int nblkptr;
2220
2221		object = drro->drr_object;
2222
2223		nblkptr = deduce_nblkptr(drro->drr_bonustype,
2224		    drro->drr_bonuslen);
2225
2226		if (drro->drr_blksz != doi.doi_data_block_size ||
2227		    nblkptr < doi.doi_nblkptr ||
2228		    dn_slots != doi.doi_dnodesize >> DNODE_SHIFT) {
2229			err = dmu_free_long_range(rwa->os, drro->drr_object,
2230			    0, DMU_OBJECT_END);
2231			if (err != 0)
2232				return (SET_ERROR(EINVAL));
2233		}
2234	} else if (err == EEXIST) {
2235		/*
2236		 * The object requested is currently an interior slot of a
2237		 * multi-slot dnode. This will be resolved when the next txg
2238		 * is synced out, since the send stream will have told us
2239		 * to free this slot when we freed the associated dnode
2240		 * earlier in the stream.
2241		 */
2242		txg_wait_synced(dmu_objset_pool(rwa->os), 0);
2243		object = drro->drr_object;
2244	} else {
2245		/* object is free and we are about to allocate a new one */
2246		object = DMU_NEW_OBJECT;
2247	}
2248
2249	/*
2250	 * If this is a multi-slot dnode there is a chance that this
2251	 * object will expand into a slot that is already used by
2252	 * another object from the previous snapshot. We must free
2253	 * these objects before we attempt to allocate the new dnode.
2254	 */
2255	if (dn_slots > 1) {
2256		boolean_t need_sync = B_FALSE;
2257
2258		for (uint64_t slot = drro->drr_object + 1;
2259		    slot < drro->drr_object + dn_slots;
2260		    slot++) {
2261			dmu_object_info_t slot_doi;
2262
2263			err = dmu_object_info(rwa->os, slot, &slot_doi);
2264			if (err == ENOENT || err == EEXIST)
2265				continue;
2266			else if (err != 0)
2267				return (err);
2268
2269			err = dmu_free_long_object(rwa->os, slot);
2270
2271			if (err != 0)
2272				return (err);
2273
2274			need_sync = B_TRUE;
2275		}
2276
2277		if (need_sync)
2278			txg_wait_synced(dmu_objset_pool(rwa->os), 0);
2279	}
2280
2281	tx = dmu_tx_create(rwa->os);
2282	dmu_tx_hold_bonus(tx, object);
2283	err = dmu_tx_assign(tx, TXG_WAIT);
2284	if (err != 0) {
2285		dmu_tx_abort(tx);
2286		return (err);
2287	}
2288
2289	if (object == DMU_NEW_OBJECT) {
2290		/* currently free, want to be allocated */
2291		err = dmu_object_claim_dnsize(rwa->os, drro->drr_object,
2292		    drro->drr_type, drro->drr_blksz,
2293		    drro->drr_bonustype, drro->drr_bonuslen,
2294		    dn_slots << DNODE_SHIFT, tx);
2295	} else if (drro->drr_type != doi.doi_type ||
2296	    drro->drr_blksz != doi.doi_data_block_size ||
2297	    drro->drr_bonustype != doi.doi_bonus_type ||
2298	    drro->drr_bonuslen != doi.doi_bonus_size ||
2299	    drro->drr_dn_slots != (doi.doi_dnodesize >> DNODE_SHIFT)) {
2300		/* currently allocated, but with different properties */
2301		err = dmu_object_reclaim_dnsize(rwa->os, drro->drr_object,
2302		    drro->drr_type, drro->drr_blksz,
2303		    drro->drr_bonustype, drro->drr_bonuslen,
2304		    drro->drr_dn_slots << DNODE_SHIFT, tx);
2305	}
2306	if (err != 0) {
2307		dmu_tx_commit(tx);
2308		return (SET_ERROR(EINVAL));
2309	}
2310
2311	dmu_object_set_checksum(rwa->os, drro->drr_object,
2312	    drro->drr_checksumtype, tx);
2313	dmu_object_set_compress(rwa->os, drro->drr_object,
2314	    drro->drr_compress, tx);
2315
2316	if (data != NULL) {
2317		dmu_buf_t *db;
2318
2319		VERIFY0(dmu_bonus_hold(rwa->os, drro->drr_object, FTAG, &db));
2320		dmu_buf_will_dirty(db, tx);
2321
2322		ASSERT3U(db->db_size, >=, drro->drr_bonuslen);
2323		bcopy(data, db->db_data, drro->drr_bonuslen);
2324		if (rwa->byteswap) {
2325			dmu_object_byteswap_t byteswap =
2326			    DMU_OT_BYTESWAP(drro->drr_bonustype);
2327			dmu_ot_byteswap[byteswap].ob_func(db->db_data,
2328			    drro->drr_bonuslen);
2329		}
2330		dmu_buf_rele(db, FTAG);
2331	}
2332	dmu_tx_commit(tx);
2333
2334	return (0);
2335}
2336
2337/* ARGSUSED */
2338noinline static int
2339receive_freeobjects(struct receive_writer_arg *rwa,
2340    struct drr_freeobjects *drrfo)
2341{
2342	uint64_t obj;
2343	int next_err = 0;
2344
2345	if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
2346		return (SET_ERROR(EINVAL));
2347
2348	for (obj = drrfo->drr_firstobj == 0 ? 1 : drrfo->drr_firstobj;
2349	    obj < drrfo->drr_firstobj + drrfo->drr_numobjs && next_err == 0;
2350	    next_err = dmu_object_next(rwa->os, &obj, FALSE, 0)) {
2351		dmu_object_info_t doi;
2352		int err;
2353
2354		err = dmu_object_info(rwa->os, obj, NULL);
2355		if (err == ENOENT)
2356			continue;
2357		else if (err != 0)
2358			return (err);
2359
2360		err = dmu_free_long_object(rwa->os, obj);
2361		if (err != 0)
2362			return (err);
2363
2364		if (obj > rwa->max_object)
2365			rwa->max_object = obj;
2366	}
2367	if (next_err != ESRCH)
2368		return (next_err);
2369	return (0);
2370}
2371
2372noinline static int
2373receive_write(struct receive_writer_arg *rwa, struct drr_write *drrw,
2374    arc_buf_t *abuf)
2375{
2376	dmu_tx_t *tx;
2377	int err;
2378
2379	if (drrw->drr_offset + drrw->drr_logical_size < drrw->drr_offset ||
2380	    !DMU_OT_IS_VALID(drrw->drr_type))
2381		return (SET_ERROR(EINVAL));
2382
2383	/*
2384	 * For resuming to work, records must be in increasing order
2385	 * by (object, offset).
2386	 */
2387	if (drrw->drr_object < rwa->last_object ||
2388	    (drrw->drr_object == rwa->last_object &&
2389	    drrw->drr_offset < rwa->last_offset)) {
2390		return (SET_ERROR(EINVAL));
2391	}
2392	rwa->last_object = drrw->drr_object;
2393	rwa->last_offset = drrw->drr_offset;
2394
2395	if (rwa->last_object > rwa->max_object)
2396		rwa->max_object = rwa->last_object;
2397
2398	if (dmu_object_info(rwa->os, drrw->drr_object, NULL) != 0)
2399		return (SET_ERROR(EINVAL));
2400
2401	tx = dmu_tx_create(rwa->os);
2402	dmu_tx_hold_write(tx, drrw->drr_object,
2403	    drrw->drr_offset, drrw->drr_logical_size);
2404	err = dmu_tx_assign(tx, TXG_WAIT);
2405	if (err != 0) {
2406		dmu_tx_abort(tx);
2407		return (err);
2408	}
2409	if (rwa->byteswap) {
2410		dmu_object_byteswap_t byteswap =
2411		    DMU_OT_BYTESWAP(drrw->drr_type);
2412		dmu_ot_byteswap[byteswap].ob_func(abuf->b_data,
2413		    DRR_WRITE_PAYLOAD_SIZE(drrw));
2414	}
2415
2416	/* use the bonus buf to look up the dnode in dmu_assign_arcbuf */
2417	dmu_buf_t *bonus;
2418	if (dmu_bonus_hold(rwa->os, drrw->drr_object, FTAG, &bonus) != 0)
2419		return (SET_ERROR(EINVAL));
2420	dmu_assign_arcbuf(bonus, drrw->drr_offset, abuf, tx);
2421
2422	/*
2423	 * Note: If the receive fails, we want the resume stream to start
2424	 * with the same record that we last successfully received (as opposed
2425	 * to the next record), so that we can verify that we are
2426	 * resuming from the correct location.
2427	 */
2428	save_resume_state(rwa, drrw->drr_object, drrw->drr_offset, tx);
2429	dmu_tx_commit(tx);
2430	dmu_buf_rele(bonus, FTAG);
2431
2432	return (0);
2433}
2434
2435/*
2436 * Handle a DRR_WRITE_BYREF record.  This record is used in dedup'ed
2437 * streams to refer to a copy of the data that is already on the
2438 * system because it came in earlier in the stream.  This function
2439 * finds the earlier copy of the data, and uses that copy instead of
2440 * data from the stream to fulfill this write.
2441 */
2442static int
2443receive_write_byref(struct receive_writer_arg *rwa,
2444    struct drr_write_byref *drrwbr)
2445{
2446	dmu_tx_t *tx;
2447	int err;
2448	guid_map_entry_t gmesrch;
2449	guid_map_entry_t *gmep;
2450	avl_index_t where;
2451	objset_t *ref_os = NULL;
2452	dmu_buf_t *dbp;
2453
2454	if (drrwbr->drr_offset + drrwbr->drr_length < drrwbr->drr_offset)
2455		return (SET_ERROR(EINVAL));
2456
2457	/*
2458	 * If the GUID of the referenced dataset is different from the
2459	 * GUID of the target dataset, find the referenced dataset.
2460	 */
2461	if (drrwbr->drr_toguid != drrwbr->drr_refguid) {
2462		gmesrch.guid = drrwbr->drr_refguid;
2463		if ((gmep = avl_find(rwa->guid_to_ds_map, &gmesrch,
2464		    &where)) == NULL) {
2465			return (SET_ERROR(EINVAL));
2466		}
2467		if (dmu_objset_from_ds(gmep->gme_ds, &ref_os))
2468			return (SET_ERROR(EINVAL));
2469	} else {
2470		ref_os = rwa->os;
2471	}
2472
2473	if (drrwbr->drr_object > rwa->max_object)
2474		rwa->max_object = drrwbr->drr_object;
2475
2476	err = dmu_buf_hold(ref_os, drrwbr->drr_refobject,
2477	    drrwbr->drr_refoffset, FTAG, &dbp, DMU_READ_PREFETCH);
2478	if (err != 0)
2479		return (err);
2480
2481	tx = dmu_tx_create(rwa->os);
2482
2483	dmu_tx_hold_write(tx, drrwbr->drr_object,
2484	    drrwbr->drr_offset, drrwbr->drr_length);
2485	err = dmu_tx_assign(tx, TXG_WAIT);
2486	if (err != 0) {
2487		dmu_tx_abort(tx);
2488		return (err);
2489	}
2490	dmu_write(rwa->os, drrwbr->drr_object,
2491	    drrwbr->drr_offset, drrwbr->drr_length, dbp->db_data, tx);
2492	dmu_buf_rele(dbp, FTAG);
2493
2494	/* See comment in restore_write. */
2495	save_resume_state(rwa, drrwbr->drr_object, drrwbr->drr_offset, tx);
2496	dmu_tx_commit(tx);
2497	return (0);
2498}
2499
2500static int
2501receive_write_embedded(struct receive_writer_arg *rwa,
2502    struct drr_write_embedded *drrwe, void *data)
2503{
2504	dmu_tx_t *tx;
2505	int err;
2506
2507	if (drrwe->drr_offset + drrwe->drr_length < drrwe->drr_offset)
2508		return (EINVAL);
2509
2510	if (drrwe->drr_psize > BPE_PAYLOAD_SIZE)
2511		return (EINVAL);
2512
2513	if (drrwe->drr_etype >= NUM_BP_EMBEDDED_TYPES)
2514		return (EINVAL);
2515	if (drrwe->drr_compression >= ZIO_COMPRESS_FUNCTIONS)
2516		return (EINVAL);
2517
2518	if (drrwe->drr_object > rwa->max_object)
2519		rwa->max_object = drrwe->drr_object;
2520
2521	tx = dmu_tx_create(rwa->os);
2522
2523	dmu_tx_hold_write(tx, drrwe->drr_object,
2524	    drrwe->drr_offset, drrwe->drr_length);
2525	err = dmu_tx_assign(tx, TXG_WAIT);
2526	if (err != 0) {
2527		dmu_tx_abort(tx);
2528		return (err);
2529	}
2530
2531	dmu_write_embedded(rwa->os, drrwe->drr_object,
2532	    drrwe->drr_offset, data, drrwe->drr_etype,
2533	    drrwe->drr_compression, drrwe->drr_lsize, drrwe->drr_psize,
2534	    rwa->byteswap ^ ZFS_HOST_BYTEORDER, tx);
2535
2536	/* See comment in restore_write. */
2537	save_resume_state(rwa, drrwe->drr_object, drrwe->drr_offset, tx);
2538	dmu_tx_commit(tx);
2539	return (0);
2540}
2541
2542static int
2543receive_spill(struct receive_writer_arg *rwa, struct drr_spill *drrs,
2544    void *data)
2545{
2546	dmu_tx_t *tx;
2547	dmu_buf_t *db, *db_spill;
2548	int err;
2549
2550	if (drrs->drr_length < SPA_MINBLOCKSIZE ||
2551	    drrs->drr_length > spa_maxblocksize(dmu_objset_spa(rwa->os)))
2552		return (SET_ERROR(EINVAL));
2553
2554	if (dmu_object_info(rwa->os, drrs->drr_object, NULL) != 0)
2555		return (SET_ERROR(EINVAL));
2556
2557	if (drrs->drr_object > rwa->max_object)
2558		rwa->max_object = drrs->drr_object;
2559
2560	VERIFY0(dmu_bonus_hold(rwa->os, drrs->drr_object, FTAG, &db));
2561	if ((err = dmu_spill_hold_by_bonus(db, FTAG, &db_spill)) != 0) {
2562		dmu_buf_rele(db, FTAG);
2563		return (err);
2564	}
2565
2566	tx = dmu_tx_create(rwa->os);
2567
2568	dmu_tx_hold_spill(tx, db->db_object);
2569
2570	err = dmu_tx_assign(tx, TXG_WAIT);
2571	if (err != 0) {
2572		dmu_buf_rele(db, FTAG);
2573		dmu_buf_rele(db_spill, FTAG);
2574		dmu_tx_abort(tx);
2575		return (err);
2576	}
2577	dmu_buf_will_dirty(db_spill, tx);
2578
2579	if (db_spill->db_size < drrs->drr_length)
2580		VERIFY(0 == dbuf_spill_set_blksz(db_spill,
2581		    drrs->drr_length, tx));
2582	bcopy(data, db_spill->db_data, drrs->drr_length);
2583
2584	dmu_buf_rele(db, FTAG);
2585	dmu_buf_rele(db_spill, FTAG);
2586
2587	dmu_tx_commit(tx);
2588	return (0);
2589}
2590
2591/* ARGSUSED */
2592noinline static int
2593receive_free(struct receive_writer_arg *rwa, struct drr_free *drrf)
2594{
2595	int err;
2596
2597	if (drrf->drr_length != -1ULL &&
2598	    drrf->drr_offset + drrf->drr_length < drrf->drr_offset)
2599		return (SET_ERROR(EINVAL));
2600
2601	if (dmu_object_info(rwa->os, drrf->drr_object, NULL) != 0)
2602		return (SET_ERROR(EINVAL));
2603
2604	if (drrf->drr_object > rwa->max_object)
2605		rwa->max_object = drrf->drr_object;
2606
2607	err = dmu_free_long_range(rwa->os, drrf->drr_object,
2608	    drrf->drr_offset, drrf->drr_length);
2609
2610	return (err);
2611}
2612
2613/* used to destroy the drc_ds on error */
2614static void
2615dmu_recv_cleanup_ds(dmu_recv_cookie_t *drc)
2616{
2617	if (drc->drc_resumable) {
2618		/* wait for our resume state to be written to disk */
2619		txg_wait_synced(drc->drc_ds->ds_dir->dd_pool, 0);
2620		dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
2621	} else {
2622		char name[ZFS_MAX_DATASET_NAME_LEN];
2623		dsl_dataset_name(drc->drc_ds, name);
2624		dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
2625		(void) dsl_destroy_head(name);
2626	}
2627}
2628
2629static void
2630receive_cksum(struct receive_arg *ra, int len, void *buf)
2631{
2632	if (ra->byteswap) {
2633		(void) fletcher_4_incremental_byteswap(buf, len, &ra->cksum);
2634	} else {
2635		(void) fletcher_4_incremental_native(buf, len, &ra->cksum);
2636	}
2637}
2638
2639/*
2640 * Read the payload into a buffer of size len, and update the current record's
2641 * payload field.
2642 * Allocate ra->next_rrd and read the next record's header into
2643 * ra->next_rrd->header.
2644 * Verify checksum of payload and next record.
2645 */
2646static int
2647receive_read_payload_and_next_header(struct receive_arg *ra, int len, void *buf)
2648{
2649	int err;
2650
2651	if (len != 0) {
2652		ASSERT3U(len, <=, SPA_MAXBLOCKSIZE);
2653		err = receive_read(ra, len, buf);
2654		if (err != 0)
2655			return (err);
2656		receive_cksum(ra, len, buf);
2657
2658		/* note: rrd is NULL when reading the begin record's payload */
2659		if (ra->rrd != NULL) {
2660			ra->rrd->payload = buf;
2661			ra->rrd->payload_size = len;
2662			ra->rrd->bytes_read = ra->bytes_read;
2663		}
2664	}
2665
2666	ra->prev_cksum = ra->cksum;
2667
2668	ra->next_rrd = kmem_zalloc(sizeof (*ra->next_rrd), KM_SLEEP);
2669	err = receive_read(ra, sizeof (ra->next_rrd->header),
2670	    &ra->next_rrd->header);
2671	ra->next_rrd->bytes_read = ra->bytes_read;
2672	if (err != 0) {
2673		kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
2674		ra->next_rrd = NULL;
2675		return (err);
2676	}
2677	if (ra->next_rrd->header.drr_type == DRR_BEGIN) {
2678		kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
2679		ra->next_rrd = NULL;
2680		return (SET_ERROR(EINVAL));
2681	}
2682
2683	/*
2684	 * Note: checksum is of everything up to but not including the
2685	 * checksum itself.
2686	 */
2687	ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
2688	    ==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
2689	receive_cksum(ra,
2690	    offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
2691	    &ra->next_rrd->header);
2692
2693	zio_cksum_t cksum_orig =
2694	    ra->next_rrd->header.drr_u.drr_checksum.drr_checksum;
2695	zio_cksum_t *cksump =
2696	    &ra->next_rrd->header.drr_u.drr_checksum.drr_checksum;
2697
2698	if (ra->byteswap)
2699		byteswap_record(&ra->next_rrd->header);
2700
2701	if ((!ZIO_CHECKSUM_IS_ZERO(cksump)) &&
2702	    !ZIO_CHECKSUM_EQUAL(ra->cksum, *cksump)) {
2703		kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
2704		ra->next_rrd = NULL;
2705		return (SET_ERROR(ECKSUM));
2706	}
2707
2708	receive_cksum(ra, sizeof (cksum_orig), &cksum_orig);
2709
2710	return (0);
2711}
2712
2713static void
2714objlist_create(struct objlist *list)
2715{
2716	list_create(&list->list, sizeof (struct receive_objnode),
2717	    offsetof(struct receive_objnode, node));
2718	list->last_lookup = 0;
2719}
2720
2721static void
2722objlist_destroy(struct objlist *list)
2723{
2724	for (struct receive_objnode *n = list_remove_head(&list->list);
2725	    n != NULL; n = list_remove_head(&list->list)) {
2726		kmem_free(n, sizeof (*n));
2727	}
2728	list_destroy(&list->list);
2729}
2730
2731/*
2732 * This function looks through the objlist to see if the specified object number
2733 * is contained in the objlist.  In the process, it will remove all object
2734 * numbers in the list that are smaller than the specified object number.  Thus,
2735 * any lookup of an object number smaller than a previously looked up object
2736 * number will always return false; therefore, all lookups should be done in
2737 * ascending order.
2738 */
2739static boolean_t
2740objlist_exists(struct objlist *list, uint64_t object)
2741{
2742	struct receive_objnode *node = list_head(&list->list);
2743	ASSERT3U(object, >=, list->last_lookup);
2744	list->last_lookup = object;
2745	while (node != NULL && node->object < object) {
2746		VERIFY3P(node, ==, list_remove_head(&list->list));
2747		kmem_free(node, sizeof (*node));
2748		node = list_head(&list->list);
2749	}
2750	return (node != NULL && node->object == object);
2751}
2752
2753/*
2754 * The objlist is a list of object numbers stored in ascending order.  However,
2755 * the insertion of new object numbers does not seek out the correct location to
2756 * store a new object number; instead, it appends it to the list for simplicity.
2757 * Thus, any users must take care to only insert new object numbers in ascending
2758 * order.
2759 */
2760static void
2761objlist_insert(struct objlist *list, uint64_t object)
2762{
2763	struct receive_objnode *node = kmem_zalloc(sizeof (*node), KM_SLEEP);
2764	node->object = object;
2765#ifdef ZFS_DEBUG
2766	struct receive_objnode *last_object = list_tail(&list->list);
2767	uint64_t last_objnum = (last_object != NULL ? last_object->object : 0);
2768	ASSERT3U(node->object, >, last_objnum);
2769#endif
2770	list_insert_tail(&list->list, node);
2771}
2772
2773/*
2774 * Issue the prefetch reads for any necessary indirect blocks.
2775 *
2776 * We use the object ignore list to tell us whether or not to issue prefetches
2777 * for a given object.  We do this for both correctness (in case the blocksize
2778 * of an object has changed) and performance (if the object doesn't exist, don't
2779 * needlessly try to issue prefetches).  We also trim the list as we go through
2780 * the stream to prevent it from growing to an unbounded size.
2781 *
2782 * The object numbers within will always be in sorted order, and any write
2783 * records we see will also be in sorted order, but they're not sorted with
2784 * respect to each other (i.e. we can get several object records before
2785 * receiving each object's write records).  As a result, once we've reached a
2786 * given object number, we can safely remove any reference to lower object
2787 * numbers in the ignore list. In practice, we receive up to 32 object records
2788 * before receiving write records, so the list can have up to 32 nodes in it.
2789 */
2790/* ARGSUSED */
2791static void
2792receive_read_prefetch(struct receive_arg *ra,
2793    uint64_t object, uint64_t offset, uint64_t length)
2794{
2795	if (!objlist_exists(&ra->ignore_objlist, object)) {
2796		dmu_prefetch(ra->os, object, 1, offset, length,
2797		    ZIO_PRIORITY_SYNC_READ);
2798	}
2799}
2800
2801/*
2802 * Read records off the stream, issuing any necessary prefetches.
2803 */
2804static int
2805receive_read_record(struct receive_arg *ra)
2806{
2807	int err;
2808
2809	switch (ra->rrd->header.drr_type) {
2810	case DRR_OBJECT:
2811	{
2812		struct drr_object *drro = &ra->rrd->header.drr_u.drr_object;
2813		uint32_t size = P2ROUNDUP(drro->drr_bonuslen, 8);
2814		void *buf = kmem_zalloc(size, KM_SLEEP);
2815		dmu_object_info_t doi;
2816		err = receive_read_payload_and_next_header(ra, size, buf);
2817		if (err != 0) {
2818			kmem_free(buf, size);
2819			return (err);
2820		}
2821		err = dmu_object_info(ra->os, drro->drr_object, &doi);
2822		/*
2823		 * See receive_read_prefetch for an explanation why we're
2824		 * storing this object in the ignore_obj_list.
2825		 */
2826		if (err == ENOENT ||
2827		    (err == 0 && doi.doi_data_block_size != drro->drr_blksz)) {
2828			objlist_insert(&ra->ignore_objlist, drro->drr_object);
2829			err = 0;
2830		}
2831		return (err);
2832	}
2833	case DRR_FREEOBJECTS:
2834	{
2835		err = receive_read_payload_and_next_header(ra, 0, NULL);
2836		return (err);
2837	}
2838	case DRR_WRITE:
2839	{
2840		struct drr_write *drrw = &ra->rrd->header.drr_u.drr_write;
2841		arc_buf_t *abuf;
2842		boolean_t is_meta = DMU_OT_IS_METADATA(drrw->drr_type);
2843		if (DRR_WRITE_COMPRESSED(drrw)) {
2844			ASSERT3U(drrw->drr_compressed_size, >, 0);
2845			ASSERT3U(drrw->drr_logical_size, >=,
2846			    drrw->drr_compressed_size);
2847			ASSERT(!is_meta);
2848			abuf = arc_loan_compressed_buf(
2849			    dmu_objset_spa(ra->os),
2850			    drrw->drr_compressed_size, drrw->drr_logical_size,
2851			    drrw->drr_compressiontype);
2852		} else {
2853			abuf = arc_loan_buf(dmu_objset_spa(ra->os),
2854			    is_meta, drrw->drr_logical_size);
2855		}
2856
2857		err = receive_read_payload_and_next_header(ra,
2858		    DRR_WRITE_PAYLOAD_SIZE(drrw), abuf->b_data);
2859		if (err != 0) {
2860			dmu_return_arcbuf(abuf);
2861			return (err);
2862		}
2863		ra->rrd->write_buf = abuf;
2864		receive_read_prefetch(ra, drrw->drr_object, drrw->drr_offset,
2865		    drrw->drr_logical_size);
2866		return (err);
2867	}
2868	case DRR_WRITE_BYREF:
2869	{
2870		struct drr_write_byref *drrwb =
2871		    &ra->rrd->header.drr_u.drr_write_byref;
2872		err = receive_read_payload_and_next_header(ra, 0, NULL);
2873		receive_read_prefetch(ra, drrwb->drr_object, drrwb->drr_offset,
2874		    drrwb->drr_length);
2875		return (err);
2876	}
2877	case DRR_WRITE_EMBEDDED:
2878	{
2879		struct drr_write_embedded *drrwe =
2880		    &ra->rrd->header.drr_u.drr_write_embedded;
2881		uint32_t size = P2ROUNDUP(drrwe->drr_psize, 8);
2882		void *buf = kmem_zalloc(size, KM_SLEEP);
2883
2884		err = receive_read_payload_and_next_header(ra, size, buf);
2885		if (err != 0) {
2886			kmem_free(buf, size);
2887			return (err);
2888		}
2889
2890		receive_read_prefetch(ra, drrwe->drr_object, drrwe->drr_offset,
2891		    drrwe->drr_length);
2892		return (err);
2893	}
2894	case DRR_FREE:
2895	{
2896		/*
2897		 * It might be beneficial to prefetch indirect blocks here, but
2898		 * we don't really have the data to decide for sure.
2899		 */
2900		err = receive_read_payload_and_next_header(ra, 0, NULL);
2901		return (err);
2902	}
2903	case DRR_END:
2904	{
2905		struct drr_end *drre = &ra->rrd->header.drr_u.drr_end;
2906		if (!ZIO_CHECKSUM_EQUAL(ra->prev_cksum, drre->drr_checksum))
2907			return (SET_ERROR(ECKSUM));
2908		return (0);
2909	}
2910	case DRR_SPILL:
2911	{
2912		struct drr_spill *drrs = &ra->rrd->header.drr_u.drr_spill;
2913		void *buf = kmem_zalloc(drrs->drr_length, KM_SLEEP);
2914		err = receive_read_payload_and_next_header(ra, drrs->drr_length,
2915		    buf);
2916		if (err != 0)
2917			kmem_free(buf, drrs->drr_length);
2918		return (err);
2919	}
2920	default:
2921		return (SET_ERROR(EINVAL));
2922	}
2923}
2924
2925/*
2926 * Commit the records to the pool.
2927 */
2928static int
2929receive_process_record(struct receive_writer_arg *rwa,
2930    struct receive_record_arg *rrd)
2931{
2932	int err;
2933
2934	/* Processing in order, therefore bytes_read should be increasing. */
2935	ASSERT3U(rrd->bytes_read, >=, rwa->bytes_read);
2936	rwa->bytes_read = rrd->bytes_read;
2937
2938	switch (rrd->header.drr_type) {
2939	case DRR_OBJECT:
2940	{
2941		struct drr_object *drro = &rrd->header.drr_u.drr_object;
2942		err = receive_object(rwa, drro, rrd->payload);
2943		kmem_free(rrd->payload, rrd->payload_size);
2944		rrd->payload = NULL;
2945		return (err);
2946	}
2947	case DRR_FREEOBJECTS:
2948	{
2949		struct drr_freeobjects *drrfo =
2950		    &rrd->header.drr_u.drr_freeobjects;
2951		return (receive_freeobjects(rwa, drrfo));
2952	}
2953	case DRR_WRITE:
2954	{
2955		struct drr_write *drrw = &rrd->header.drr_u.drr_write;
2956		err = receive_write(rwa, drrw, rrd->write_buf);
2957		/* if receive_write() is successful, it consumes the arc_buf */
2958		if (err != 0)
2959			dmu_return_arcbuf(rrd->write_buf);
2960		rrd->write_buf = NULL;
2961		rrd->payload = NULL;
2962		return (err);
2963	}
2964	case DRR_WRITE_BYREF:
2965	{
2966		struct drr_write_byref *drrwbr =
2967		    &rrd->header.drr_u.drr_write_byref;
2968		return (receive_write_byref(rwa, drrwbr));
2969	}
2970	case DRR_WRITE_EMBEDDED:
2971	{
2972		struct drr_write_embedded *drrwe =
2973		    &rrd->header.drr_u.drr_write_embedded;
2974		err = receive_write_embedded(rwa, drrwe, rrd->payload);
2975		kmem_free(rrd->payload, rrd->payload_size);
2976		rrd->payload = NULL;
2977		return (err);
2978	}
2979	case DRR_FREE:
2980	{
2981		struct drr_free *drrf = &rrd->header.drr_u.drr_free;
2982		return (receive_free(rwa, drrf));
2983	}
2984	case DRR_SPILL:
2985	{
2986		struct drr_spill *drrs = &rrd->header.drr_u.drr_spill;
2987		err = receive_spill(rwa, drrs, rrd->payload);
2988		kmem_free(rrd->payload, rrd->payload_size);
2989		rrd->payload = NULL;
2990		return (err);
2991	}
2992	default:
2993		return (SET_ERROR(EINVAL));
2994	}
2995}
2996
2997/*
2998 * dmu_recv_stream's worker thread; pull records off the queue, and then call
2999 * receive_process_record  When we're done, signal the main thread and exit.
3000 */
3001static void
3002receive_writer_thread(void *arg)
3003{
3004	struct receive_writer_arg *rwa = arg;
3005	struct receive_record_arg *rrd;
3006	for (rrd = bqueue_dequeue(&rwa->q); !rrd->eos_marker;
3007	    rrd = bqueue_dequeue(&rwa->q)) {
3008		/*
3009		 * If there's an error, the main thread will stop putting things
3010		 * on the queue, but we need to clear everything in it before we
3011		 * can exit.
3012		 */
3013		if (rwa->err == 0) {
3014			rwa->err = receive_process_record(rwa, rrd);
3015		} else if (rrd->write_buf != NULL) {
3016			dmu_return_arcbuf(rrd->write_buf);
3017			rrd->write_buf = NULL;
3018			rrd->payload = NULL;
3019		} else if (rrd->payload != NULL) {
3020			kmem_free(rrd->payload, rrd->payload_size);
3021			rrd->payload = NULL;
3022		}
3023		kmem_free(rrd, sizeof (*rrd));
3024	}
3025	kmem_free(rrd, sizeof (*rrd));
3026	mutex_enter(&rwa->mutex);
3027	rwa->done = B_TRUE;
3028	cv_signal(&rwa->cv);
3029	mutex_exit(&rwa->mutex);
3030	thread_exit();
3031}
3032
3033static int
3034resume_check(struct receive_arg *ra, nvlist_t *begin_nvl)
3035{
3036	uint64_t val;
3037	objset_t *mos = dmu_objset_pool(ra->os)->dp_meta_objset;
3038	uint64_t dsobj = dmu_objset_id(ra->os);
3039	uint64_t resume_obj, resume_off;
3040
3041	if (nvlist_lookup_uint64(begin_nvl,
3042	    "resume_object", &resume_obj) != 0 ||
3043	    nvlist_lookup_uint64(begin_nvl,
3044	    "resume_offset", &resume_off) != 0) {
3045		return (SET_ERROR(EINVAL));
3046	}
3047	VERIFY0(zap_lookup(mos, dsobj,
3048	    DS_FIELD_RESUME_OBJECT, sizeof (val), 1, &val));
3049	if (resume_obj != val)
3050		return (SET_ERROR(EINVAL));
3051	VERIFY0(zap_lookup(mos, dsobj,
3052	    DS_FIELD_RESUME_OFFSET, sizeof (val), 1, &val));
3053	if (resume_off != val)
3054		return (SET_ERROR(EINVAL));
3055
3056	return (0);
3057}
3058
3059/*
3060 * Read in the stream's records, one by one, and apply them to the pool.  There
3061 * are two threads involved; the thread that calls this function will spin up a
3062 * worker thread, read the records off the stream one by one, and issue
3063 * prefetches for any necessary indirect blocks.  It will then push the records
3064 * onto an internal blocking queue.  The worker thread will pull the records off
3065 * the queue, and actually write the data into the DMU.  This way, the worker
3066 * thread doesn't have to wait for reads to complete, since everything it needs
3067 * (the indirect blocks) will be prefetched.
3068 *
3069 * NB: callers *must* call dmu_recv_end() if this succeeds.
3070 */
3071int
3072dmu_recv_stream(dmu_recv_cookie_t *drc, struct file *fp, offset_t *voffp,
3073    int cleanup_fd, uint64_t *action_handlep)
3074{
3075	int err = 0;
3076	struct receive_arg ra = { 0 };
3077	struct receive_writer_arg rwa = { 0 };
3078	int featureflags;
3079	nvlist_t *begin_nvl = NULL;
3080
3081	ra.byteswap = drc->drc_byteswap;
3082	ra.cksum = drc->drc_cksum;
3083	ra.td = curthread;
3084	ra.fp = fp;
3085	ra.voff = *voffp;
3086
3087	if (dsl_dataset_is_zapified(drc->drc_ds)) {
3088		(void) zap_lookup(drc->drc_ds->ds_dir->dd_pool->dp_meta_objset,
3089		    drc->drc_ds->ds_object, DS_FIELD_RESUME_BYTES,
3090		    sizeof (ra.bytes_read), 1, &ra.bytes_read);
3091	}
3092
3093	objlist_create(&ra.ignore_objlist);
3094
3095	/* these were verified in dmu_recv_begin */
3096	ASSERT3U(DMU_GET_STREAM_HDRTYPE(drc->drc_drrb->drr_versioninfo), ==,
3097	    DMU_SUBSTREAM);
3098	ASSERT3U(drc->drc_drrb->drr_type, <, DMU_OST_NUMTYPES);
3099
3100	/*
3101	 * Open the objset we are modifying.
3102	 */
3103	VERIFY0(dmu_objset_from_ds(drc->drc_ds, &ra.os));
3104
3105	ASSERT(dsl_dataset_phys(drc->drc_ds)->ds_flags & DS_FLAG_INCONSISTENT);
3106
3107	featureflags = DMU_GET_FEATUREFLAGS(drc->drc_drrb->drr_versioninfo);
3108
3109	/* if this stream is dedup'ed, set up the avl tree for guid mapping */
3110	if (featureflags & DMU_BACKUP_FEATURE_DEDUP) {
3111		minor_t minor;
3112
3113		if (cleanup_fd == -1) {
3114			ra.err = SET_ERROR(EBADF);
3115			goto out;
3116		}
3117		ra.err = zfs_onexit_fd_hold(cleanup_fd, &minor);
3118		if (ra.err != 0) {
3119			cleanup_fd = -1;
3120			goto out;
3121		}
3122
3123		if (*action_handlep == 0) {
3124			rwa.guid_to_ds_map =
3125			    kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
3126			avl_create(rwa.guid_to_ds_map, guid_compare,
3127			    sizeof (guid_map_entry_t),
3128			    offsetof(guid_map_entry_t, avlnode));
3129			err = zfs_onexit_add_cb(minor,
3130			    free_guid_map_onexit, rwa.guid_to_ds_map,
3131			    action_handlep);
3132			if (ra.err != 0)
3133				goto out;
3134		} else {
3135			err = zfs_onexit_cb_data(minor, *action_handlep,
3136			    (void **)&rwa.guid_to_ds_map);
3137			if (ra.err != 0)
3138				goto out;
3139		}
3140
3141		drc->drc_guid_to_ds_map = rwa.guid_to_ds_map;
3142	}
3143
3144	uint32_t payloadlen = drc->drc_drr_begin->drr_payloadlen;
3145	void *payload = NULL;
3146	if (payloadlen != 0)
3147		payload = kmem_alloc(payloadlen, KM_SLEEP);
3148
3149	err = receive_read_payload_and_next_header(&ra, payloadlen, payload);
3150	if (err != 0) {
3151		if (payloadlen != 0)
3152			kmem_free(payload, payloadlen);
3153		goto out;
3154	}
3155	if (payloadlen != 0) {
3156		err = nvlist_unpack(payload, payloadlen, &begin_nvl, KM_SLEEP);
3157		kmem_free(payload, payloadlen);
3158		if (err != 0)
3159			goto out;
3160	}
3161
3162	if (featureflags & DMU_BACKUP_FEATURE_RESUMING) {
3163		err = resume_check(&ra, begin_nvl);
3164		if (err != 0)
3165			goto out;
3166	}
3167
3168	(void) bqueue_init(&rwa.q, zfs_recv_queue_length,
3169	    offsetof(struct receive_record_arg, node));
3170	cv_init(&rwa.cv, NULL, CV_DEFAULT, NULL);
3171	mutex_init(&rwa.mutex, NULL, MUTEX_DEFAULT, NULL);
3172	rwa.os = ra.os;
3173	rwa.byteswap = drc->drc_byteswap;
3174	rwa.resumable = drc->drc_resumable;
3175
3176	(void) thread_create(NULL, 0, receive_writer_thread, &rwa, 0, &p0,
3177	    TS_RUN, minclsyspri);
3178	/*
3179	 * We're reading rwa.err without locks, which is safe since we are the
3180	 * only reader, and the worker thread is the only writer.  It's ok if we
3181	 * miss a write for an iteration or two of the loop, since the writer
3182	 * thread will keep freeing records we send it until we send it an eos
3183	 * marker.
3184	 *
3185	 * We can leave this loop in 3 ways:  First, if rwa.err is
3186	 * non-zero.  In that case, the writer thread will free the rrd we just
3187	 * pushed.  Second, if  we're interrupted; in that case, either it's the
3188	 * first loop and ra.rrd was never allocated, or it's later, and ra.rrd
3189	 * has been handed off to the writer thread who will free it.  Finally,
3190	 * if receive_read_record fails or we're at the end of the stream, then
3191	 * we free ra.rrd and exit.
3192	 */
3193	while (rwa.err == 0) {
3194		if (issig(JUSTLOOKING) && issig(FORREAL)) {
3195			err = SET_ERROR(EINTR);
3196			break;
3197		}
3198
3199		ASSERT3P(ra.rrd, ==, NULL);
3200		ra.rrd = ra.next_rrd;
3201		ra.next_rrd = NULL;
3202		/* Allocates and loads header into ra.next_rrd */
3203		err = receive_read_record(&ra);
3204
3205		if (ra.rrd->header.drr_type == DRR_END || err != 0) {
3206			kmem_free(ra.rrd, sizeof (*ra.rrd));
3207			ra.rrd = NULL;
3208			break;
3209		}
3210
3211		bqueue_enqueue(&rwa.q, ra.rrd,
3212		    sizeof (struct receive_record_arg) + ra.rrd->payload_size);
3213		ra.rrd = NULL;
3214	}
3215	if (ra.next_rrd == NULL)
3216		ra.next_rrd = kmem_zalloc(sizeof (*ra.next_rrd), KM_SLEEP);
3217	ra.next_rrd->eos_marker = B_TRUE;
3218	bqueue_enqueue(&rwa.q, ra.next_rrd, 1);
3219
3220	mutex_enter(&rwa.mutex);
3221	while (!rwa.done) {
3222		cv_wait(&rwa.cv, &rwa.mutex);
3223	}
3224	mutex_exit(&rwa.mutex);
3225
3226	/*
3227	 * If we are receiving a full stream as a clone, all object IDs which
3228	 * are greater than the maximum ID referenced in the stream are
3229	 * by definition unused and must be freed. Note that it's possible that
3230	 * we've resumed this send and the first record we received was the END
3231	 * record. In that case, max_object would be 0, but we shouldn't start
3232	 * freeing all objects from there; instead we should start from the
3233	 * resumeobj.
3234	 */
3235	if (drc->drc_clone && drc->drc_drrb->drr_fromguid == 0) {
3236		uint64_t obj;
3237		if (nvlist_lookup_uint64(begin_nvl, "resume_object", &obj) != 0)
3238			obj = 0;
3239		if (rwa.max_object > obj)
3240			obj = rwa.max_object;
3241		obj++;
3242		int free_err = 0;
3243		int next_err = 0;
3244
3245		while (next_err == 0) {
3246			free_err = dmu_free_long_object(rwa.os, obj);
3247			if (free_err != 0 && free_err != ENOENT)
3248				break;
3249
3250			next_err = dmu_object_next(rwa.os, &obj, FALSE, 0);
3251		}
3252
3253		if (err == 0) {
3254			if (free_err != 0 && free_err != ENOENT)
3255				err = free_err;
3256			else if (next_err != ESRCH)
3257				err = next_err;
3258		}
3259	}
3260
3261	cv_destroy(&rwa.cv);
3262	mutex_destroy(&rwa.mutex);
3263	bqueue_destroy(&rwa.q);
3264	if (err == 0)
3265		err = rwa.err;
3266
3267out:
3268	nvlist_free(begin_nvl);
3269	if ((featureflags & DMU_BACKUP_FEATURE_DEDUP) && (cleanup_fd != -1))
3270		zfs_onexit_fd_rele(cleanup_fd);
3271
3272	if (err != 0) {
3273		/*
3274		 * Clean up references. If receive is not resumable,
3275		 * destroy what we created, so we don't leave it in
3276		 * the inconsistent state.
3277		 */
3278		dmu_recv_cleanup_ds(drc);
3279	}
3280
3281	*voffp = ra.voff;
3282	objlist_destroy(&ra.ignore_objlist);
3283	return (err);
3284}
3285
3286static int
3287dmu_recv_end_check(void *arg, dmu_tx_t *tx)
3288{
3289	dmu_recv_cookie_t *drc = arg;
3290	dsl_pool_t *dp = dmu_tx_pool(tx);
3291	int error;
3292
3293	ASSERT3P(drc->drc_ds->ds_owner, ==, dmu_recv_tag);
3294
3295	if (!drc->drc_newfs) {
3296		dsl_dataset_t *origin_head;
3297
3298		error = dsl_dataset_hold(dp, drc->drc_tofs, FTAG, &origin_head);
3299		if (error != 0)
3300			return (error);
3301		if (drc->drc_force) {
3302			/*
3303			 * We will destroy any snapshots in tofs (i.e. before
3304			 * origin_head) that are after the origin (which is
3305			 * the snap before drc_ds, because drc_ds can not
3306			 * have any snaps of its own).
3307			 */
3308			uint64_t obj;
3309
3310			obj = dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
3311			while (obj !=
3312			    dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj) {
3313				dsl_dataset_t *snap;
3314				error = dsl_dataset_hold_obj(dp, obj, FTAG,
3315				    &snap);
3316				if (error != 0)
3317					break;
3318				if (snap->ds_dir != origin_head->ds_dir)
3319					error = SET_ERROR(EINVAL);
3320				if (error == 0)  {
3321					error = dsl_destroy_snapshot_check_impl(
3322					    snap, B_FALSE);
3323				}
3324				obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
3325				dsl_dataset_rele(snap, FTAG);
3326				if (error != 0)
3327					break;
3328			}
3329			if (error != 0) {
3330				dsl_dataset_rele(origin_head, FTAG);
3331				return (error);
3332			}
3333		}
3334		error = dsl_dataset_clone_swap_check_impl(drc->drc_ds,
3335		    origin_head, drc->drc_force, drc->drc_owner, tx);
3336		if (error != 0) {
3337			dsl_dataset_rele(origin_head, FTAG);
3338			return (error);
3339		}
3340		error = dsl_dataset_snapshot_check_impl(origin_head,
3341		    drc->drc_tosnap, tx, B_TRUE, 1, drc->drc_cred);
3342		dsl_dataset_rele(origin_head, FTAG);
3343		if (error != 0)
3344			return (error);
3345
3346		error = dsl_destroy_head_check_impl(drc->drc_ds, 1);
3347	} else {
3348		error = dsl_dataset_snapshot_check_impl(drc->drc_ds,
3349		    drc->drc_tosnap, tx, B_TRUE, 1, drc->drc_cred);
3350	}
3351	return (error);
3352}
3353
3354static void
3355dmu_recv_end_sync(void *arg, dmu_tx_t *tx)
3356{
3357	dmu_recv_cookie_t *drc = arg;
3358	dsl_pool_t *dp = dmu_tx_pool(tx);
3359
3360	spa_history_log_internal_ds(drc->drc_ds, "finish receiving",
3361	    tx, "snap=%s", drc->drc_tosnap);
3362
3363	if (!drc->drc_newfs) {
3364		dsl_dataset_t *origin_head;
3365
3366		VERIFY0(dsl_dataset_hold(dp, drc->drc_tofs, FTAG,
3367		    &origin_head));
3368
3369		if (drc->drc_force) {
3370			/*
3371			 * Destroy any snapshots of drc_tofs (origin_head)
3372			 * after the origin (the snap before drc_ds).
3373			 */
3374			uint64_t obj;
3375
3376			obj = dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
3377			while (obj !=
3378			    dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj) {
3379				dsl_dataset_t *snap;
3380				VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG,
3381				    &snap));
3382				ASSERT3P(snap->ds_dir, ==, origin_head->ds_dir);
3383				obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
3384				dsl_destroy_snapshot_sync_impl(snap,
3385				    B_FALSE, tx);
3386				dsl_dataset_rele(snap, FTAG);
3387			}
3388		}
3389		VERIFY3P(drc->drc_ds->ds_prev, ==,
3390		    origin_head->ds_prev);
3391
3392		dsl_dataset_clone_swap_sync_impl(drc->drc_ds,
3393		    origin_head, tx);
3394		dsl_dataset_snapshot_sync_impl(origin_head,
3395		    drc->drc_tosnap, tx);
3396
3397		/* set snapshot's creation time and guid */
3398		dmu_buf_will_dirty(origin_head->ds_prev->ds_dbuf, tx);
3399		dsl_dataset_phys(origin_head->ds_prev)->ds_creation_time =
3400		    drc->drc_drrb->drr_creation_time;
3401		dsl_dataset_phys(origin_head->ds_prev)->ds_guid =
3402		    drc->drc_drrb->drr_toguid;
3403		dsl_dataset_phys(origin_head->ds_prev)->ds_flags &=
3404		    ~DS_FLAG_INCONSISTENT;
3405
3406		dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
3407		dsl_dataset_phys(origin_head)->ds_flags &=
3408		    ~DS_FLAG_INCONSISTENT;
3409
3410		drc->drc_newsnapobj =
3411		    dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
3412
3413		dsl_dataset_rele(origin_head, FTAG);
3414		dsl_destroy_head_sync_impl(drc->drc_ds, tx);
3415
3416		if (drc->drc_owner != NULL)
3417			VERIFY3P(origin_head->ds_owner, ==, drc->drc_owner);
3418	} else {
3419		dsl_dataset_t *ds = drc->drc_ds;
3420
3421		dsl_dataset_snapshot_sync_impl(ds, drc->drc_tosnap, tx);
3422
3423		/* set snapshot's creation time and guid */
3424		dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
3425		dsl_dataset_phys(ds->ds_prev)->ds_creation_time =
3426		    drc->drc_drrb->drr_creation_time;
3427		dsl_dataset_phys(ds->ds_prev)->ds_guid =
3428		    drc->drc_drrb->drr_toguid;
3429		dsl_dataset_phys(ds->ds_prev)->ds_flags &=
3430		    ~DS_FLAG_INCONSISTENT;
3431
3432		dmu_buf_will_dirty(ds->ds_dbuf, tx);
3433		dsl_dataset_phys(ds)->ds_flags &= ~DS_FLAG_INCONSISTENT;
3434		if (dsl_dataset_has_resume_receive_state(ds)) {
3435			(void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3436			    DS_FIELD_RESUME_FROMGUID, tx);
3437			(void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3438			    DS_FIELD_RESUME_OBJECT, tx);
3439			(void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3440			    DS_FIELD_RESUME_OFFSET, tx);
3441			(void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3442			    DS_FIELD_RESUME_BYTES, tx);
3443			(void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3444			    DS_FIELD_RESUME_TOGUID, tx);
3445			(void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3446			    DS_FIELD_RESUME_TONAME, tx);
3447		}
3448		drc->drc_newsnapobj =
3449		    dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj;
3450	}
3451
3452#if defined(__FreeBSD__) && defined(_KERNEL)
3453	zvol_create_minors(dp->dp_spa, drc->drc_tofs);
3454#endif
3455
3456	/*
3457	 * Release the hold from dmu_recv_begin.  This must be done before
3458	 * we return to open context, so that when we free the dataset's dnode,
3459	 * we can evict its bonus buffer.
3460	 */
3461	dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
3462	drc->drc_ds = NULL;
3463}
3464
3465static int
3466add_ds_to_guidmap(const char *name, avl_tree_t *guid_map, uint64_t snapobj)
3467{
3468	dsl_pool_t *dp;
3469	dsl_dataset_t *snapds;
3470	guid_map_entry_t *gmep;
3471	int err;
3472
3473	ASSERT(guid_map != NULL);
3474
3475	err = dsl_pool_hold(name, FTAG, &dp);
3476	if (err != 0)
3477		return (err);
3478	gmep = kmem_alloc(sizeof (*gmep), KM_SLEEP);
3479	err = dsl_dataset_hold_obj(dp, snapobj, gmep, &snapds);
3480	if (err == 0) {
3481		gmep->guid = dsl_dataset_phys(snapds)->ds_guid;
3482		gmep->gme_ds = snapds;
3483		avl_add(guid_map, gmep);
3484		dsl_dataset_long_hold(snapds, gmep);
3485	} else
3486		kmem_free(gmep, sizeof (*gmep));
3487
3488	dsl_pool_rele(dp, FTAG);
3489	return (err);
3490}
3491
3492static int dmu_recv_end_modified_blocks = 3;
3493
3494static int
3495dmu_recv_existing_end(dmu_recv_cookie_t *drc)
3496{
3497#ifdef _KERNEL
3498	/*
3499	 * We will be destroying the ds; make sure its origin is unmounted if
3500	 * necessary.
3501	 */
3502	char name[ZFS_MAX_DATASET_NAME_LEN];
3503	dsl_dataset_name(drc->drc_ds, name);
3504	zfs_destroy_unmount_origin(name);
3505#endif
3506
3507	return (dsl_sync_task(drc->drc_tofs,
3508	    dmu_recv_end_check, dmu_recv_end_sync, drc,
3509	    dmu_recv_end_modified_blocks, ZFS_SPACE_CHECK_NORMAL));
3510}
3511
3512static int
3513dmu_recv_new_end(dmu_recv_cookie_t *drc)
3514{
3515	return (dsl_sync_task(drc->drc_tofs,
3516	    dmu_recv_end_check, dmu_recv_end_sync, drc,
3517	    dmu_recv_end_modified_blocks, ZFS_SPACE_CHECK_NORMAL));
3518}
3519
3520int
3521dmu_recv_end(dmu_recv_cookie_t *drc, void *owner)
3522{
3523	int error;
3524
3525	drc->drc_owner = owner;
3526
3527	if (drc->drc_newfs)
3528		error = dmu_recv_new_end(drc);
3529	else
3530		error = dmu_recv_existing_end(drc);
3531
3532	if (error != 0) {
3533		dmu_recv_cleanup_ds(drc);
3534	} else if (drc->drc_guid_to_ds_map != NULL) {
3535		(void) add_ds_to_guidmap(drc->drc_tofs,
3536		    drc->drc_guid_to_ds_map,
3537		    drc->drc_newsnapobj);
3538	}
3539	return (error);
3540}
3541
3542/*
3543 * Return TRUE if this objset is currently being received into.
3544 */
3545boolean_t
3546dmu_objset_is_receiving(objset_t *os)
3547{
3548	return (os->os_dsl_dataset != NULL &&
3549	    os->os_dsl_dataset->ds_owner == dmu_recv_tag);
3550}
3551