Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
/*
 * CDDL HEADER START
 *
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2013, 2018 by Delphix. All rights reserved.
 * Copyright 2017 Nexenta Systems, Inc.
 * Copyright 2019, 2020 by Christian Schwarz. All rights reserved.
 */

#include <sys/zfs_context.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_prop.h>
#include <sys/dsl_synctask.h>
#include <sys/dsl_destroy.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/arc.h>
#include <sys/zap.h>
#include <sys/zfeature.h>
#include <sys/spa.h>
#include <sys/dsl_bookmark.h>
#include <zfs_namecheck.h>
#include <sys/dmu_send.h>

static int
dsl_bookmark_hold_ds(dsl_pool_t *dp, const char *fullname,
    dsl_dataset_t **dsp, void *tag, char **shortnamep)
{
	char buf[ZFS_MAX_DATASET_NAME_LEN];
	char *hashp;

	if (strlen(fullname) >= ZFS_MAX_DATASET_NAME_LEN)
		return (SET_ERROR(ENAMETOOLONG));
	hashp = strchr(fullname, '#');
	if (hashp == NULL)
		return (SET_ERROR(EINVAL));

	*shortnamep = hashp + 1;
	if (zfs_component_namecheck(*shortnamep, NULL, NULL))
		return (SET_ERROR(EINVAL));
	(void) strlcpy(buf, fullname, hashp - fullname + 1);
	return (dsl_dataset_hold(dp, buf, tag, dsp));
}

/*
 * When reading BOOKMARK_V1 bookmarks, the BOOKMARK_V2 fields are guaranteed
 * to be zeroed.
 *
 * Returns ESRCH if bookmark is not found.
 * Note, we need to use the ZAP rather than the AVL to look up bookmarks
 * by name, because only the ZAP honors the casesensitivity setting.
 */
int
dsl_bookmark_lookup_impl(dsl_dataset_t *ds, const char *shortname,
    zfs_bookmark_phys_t *bmark_phys)
{
	objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
	uint64_t bmark_zapobj = ds->ds_bookmarks_obj;
	matchtype_t mt = 0;
	int err;

	if (bmark_zapobj == 0)
		return (SET_ERROR(ESRCH));

	if (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_CI_DATASET)
		mt = MT_NORMALIZE;

	/*
	 * Zero out the bookmark in case the one stored on disk
	 * is in an older, shorter format.
	 */
	bzero(bmark_phys, sizeof (*bmark_phys));

	err = zap_lookup_norm(mos, bmark_zapobj, shortname, sizeof (uint64_t),
	    sizeof (*bmark_phys) / sizeof (uint64_t), bmark_phys, mt, NULL, 0,
	    NULL);

	return (err == ENOENT ? SET_ERROR(ESRCH) : err);
}

/*
 * If later_ds is non-NULL, this will return EXDEV if the specified bookmark
 * does not represents an earlier point in later_ds's timeline.  However,
 * bmp will still be filled in if we return EXDEV.
 *
 * Returns ENOENT if the dataset containing the bookmark does not exist.
 * Returns ESRCH if the dataset exists but the bookmark was not found in it.
 */
int
dsl_bookmark_lookup(dsl_pool_t *dp, const char *fullname,
    dsl_dataset_t *later_ds, zfs_bookmark_phys_t *bmp)
{
	char *shortname;
	dsl_dataset_t *ds;
	int error;

	error = dsl_bookmark_hold_ds(dp, fullname, &ds, FTAG, &shortname);
	if (error != 0)
		return (error);

	error = dsl_bookmark_lookup_impl(ds, shortname, bmp);
	if (error == 0 && later_ds != NULL) {
		if (!dsl_dataset_is_before(later_ds, ds, bmp->zbm_creation_txg))
			error = SET_ERROR(EXDEV);
	}
	dsl_dataset_rele(ds, FTAG);
	return (error);
}

/*
 * Validates that
 * - bmark is a full dataset path of a bookmark (bookmark_namecheck)
 * - source is a full path of a snapshot or bookmark
 *   ({bookmark,snapshot}_namecheck)
 *
 * Returns 0 if valid, -1 otherwise.
 */
static int
dsl_bookmark_create_nvl_validate_pair(const char *bmark, const char *source)
{
	if (bookmark_namecheck(bmark, NULL, NULL) != 0)
		return (-1);

	int is_bmark, is_snap;
	is_bmark = bookmark_namecheck(source, NULL, NULL) == 0;
	is_snap = snapshot_namecheck(source, NULL, NULL) == 0;
	if (!is_bmark && !is_snap)
		return (-1);

	return (0);
}

/*
 * Check that the given nvlist corresponds to the following schema:
 *  { newbookmark -> source, ... }
 * where
 * - each pair passes dsl_bookmark_create_nvl_validate_pair
 * - all newbookmarks are in the same pool
 * - all newbookmarks have unique names
 *
 * Note that this function is only validates above schema. Callers must ensure
 * that the bookmarks can be created, e.g. that sources exist.
 *
 * Returns 0 if the nvlist adheres to above schema.
 * Returns -1 if it doesn't.
 */
int
dsl_bookmark_create_nvl_validate(nvlist_t *bmarks)
{
	char *first;
	size_t first_len;

	first = NULL;
	for (nvpair_t *pair = nvlist_next_nvpair(bmarks, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(bmarks, pair)) {

		char *bmark = nvpair_name(pair);
		char *source;

		/* list structure: values must be snapshots XOR bookmarks */
		if (nvpair_value_string(pair, &source) != 0)
			return (-1);
		if (dsl_bookmark_create_nvl_validate_pair(bmark, source) != 0)
			return (-1);

		/* same pool check */
		if (first == NULL) {
			char *cp = strpbrk(bmark, "/#");
			if (cp == NULL)
				return (-1);
			first = bmark;
			first_len = cp - bmark;
		}
		if (strncmp(first, bmark, first_len) != 0)
			return (-1);
		switch (*(bmark + first_len)) {
			case '/': /* fallthrough */
			case '#':
				break;
			default:
				return (-1);
		}

		/* unique newbookmark names; todo: O(n^2) */
		for (nvpair_t *pair2 = nvlist_next_nvpair(bmarks, pair);
		    pair2 != NULL; pair2 = nvlist_next_nvpair(bmarks, pair2)) {
			if (strcmp(nvpair_name(pair), nvpair_name(pair2)) == 0)
				return (-1);
		}

	}
	return (0);
}

/*
 * expects that newbm and source have been validated using
 * dsl_bookmark_create_nvl_validate_pair
 */
static int
dsl_bookmark_create_check_impl(dsl_pool_t *dp,
    const char *newbm, const char *source)
{
	ASSERT0(dsl_bookmark_create_nvl_validate_pair(newbm, source));
	/* defer source namecheck until we know it's a snapshot or bookmark */

	int error;
	dsl_dataset_t *newbm_ds;
	char *newbm_short;
	zfs_bookmark_phys_t bmark_phys;

	error = dsl_bookmark_hold_ds(dp, newbm, &newbm_ds, FTAG, &newbm_short);
	if (error != 0)
		return (error);

	/* Verify that the new bookmark does not already exist */
	error = dsl_bookmark_lookup_impl(newbm_ds, newbm_short, &bmark_phys);
	switch (error) {
	case ESRCH:
		/* happy path: new bmark doesn't exist, proceed after switch */
		error = 0;
		break;
	case 0:
		error = SET_ERROR(EEXIST);
		goto eholdnewbmds;
	default:
		/* dsl_bookmark_lookup_impl already did SET_ERRROR */
		goto eholdnewbmds;
	}

	/* error is retval of the following if-cascade */
	if (strchr(source, '@') != NULL) {
		dsl_dataset_t *source_snap_ds;
		ASSERT3S(snapshot_namecheck(source, NULL, NULL), ==, 0);
		error = dsl_dataset_hold(dp, source, FTAG, &source_snap_ds);
		if (error == 0) {
			VERIFY(source_snap_ds->ds_is_snapshot);
			/*
			 * Verify that source snapshot is an earlier point in
			 * newbm_ds's timeline (source may be newbm_ds's origin)
			 */
			if (!dsl_dataset_is_before(newbm_ds, source_snap_ds, 0))
				error = SET_ERROR(
				    ZFS_ERR_BOOKMARK_SOURCE_NOT_ANCESTOR);
			dsl_dataset_rele(source_snap_ds, FTAG);
		}
	} else if (strchr(source, '#') != NULL) {
		zfs_bookmark_phys_t source_phys;
		ASSERT3S(bookmark_namecheck(source, NULL, NULL), ==, 0);
		/*
		 * Source must exists and be an earlier point in newbm_ds's
		 * timeline (newbm_ds's origin may be a snap of source's ds)
		 */
		error = dsl_bookmark_lookup(dp, source, newbm_ds, &source_phys);
		switch (error) {
		case 0:
			break; /* happy path */
		case EXDEV:
			error = SET_ERROR(ZFS_ERR_BOOKMARK_SOURCE_NOT_ANCESTOR);
			break;
		default:
			/* dsl_bookmark_lookup already did SET_ERRROR */
			break;
		}
	} else {
		/*
		 * dsl_bookmark_create_nvl_validate validates that source is
		 * either snapshot or bookmark
		 */
		panic("unreachable code: %s", source);
	}

eholdnewbmds:
	dsl_dataset_rele(newbm_ds, FTAG);
	return (error);
}

int
dsl_bookmark_create_check(void *arg, dmu_tx_t *tx)
{
	dsl_bookmark_create_arg_t *dbca = arg;
	int rv = 0;
	int schema_err = 0;
	ASSERT3P(dbca, !=, NULL);
	ASSERT3P(dbca->dbca_bmarks, !=, NULL);
	/* dbca->dbca_errors is allowed to be NULL */

	dsl_pool_t *dp = dmu_tx_pool(tx);

	if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_BOOKMARKS))
		return (SET_ERROR(ENOTSUP));

	if (dsl_bookmark_create_nvl_validate(dbca->dbca_bmarks) != 0)
		rv = schema_err = SET_ERROR(EINVAL);

	for (nvpair_t *pair = nvlist_next_nvpair(dbca->dbca_bmarks, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(dbca->dbca_bmarks, pair)) {
		char *new = nvpair_name(pair);

		int error = schema_err;
		if (error == 0) {
			char *source = fnvpair_value_string(pair);
			error = dsl_bookmark_create_check_impl(dp, new, source);
			if (error != 0)
				error = SET_ERROR(error);
		}

		if (error != 0) {
			rv = error;
			if (dbca->dbca_errors != NULL)
				fnvlist_add_int32(dbca->dbca_errors,
				    new, error);
		}
	}

	return (rv);
}

static dsl_bookmark_node_t *
dsl_bookmark_node_alloc(char *shortname)
{
	dsl_bookmark_node_t *dbn = kmem_alloc(sizeof (*dbn), KM_SLEEP);
	dbn->dbn_name = spa_strdup(shortname);
	dbn->dbn_dirty = B_FALSE;
	mutex_init(&dbn->dbn_lock, NULL, MUTEX_DEFAULT, NULL);
	return (dbn);
}

/*
 * Set the fields in the zfs_bookmark_phys_t based on the specified snapshot.
 */
static void
dsl_bookmark_set_phys(zfs_bookmark_phys_t *zbm, dsl_dataset_t *snap)
{
	spa_t *spa = dsl_dataset_get_spa(snap);
	objset_t *mos = spa_get_dsl(spa)->dp_meta_objset;
	dsl_dataset_phys_t *dsp = dsl_dataset_phys(snap);
	zbm->zbm_guid = dsp->ds_guid;
	zbm->zbm_creation_txg = dsp->ds_creation_txg;
	zbm->zbm_creation_time = dsp->ds_creation_time;
	zbm->zbm_redaction_obj = 0;

	/*
	 * If the dataset is encrypted create a larger bookmark to
	 * accommodate the IVset guid. The IVset guid was added
	 * after the encryption feature to prevent a problem with
	 * raw sends. If we encounter an encrypted dataset without
	 * an IVset guid we fall back to a normal bookmark.
	 */
	if (snap->ds_dir->dd_crypto_obj != 0 &&
	    spa_feature_is_enabled(spa, SPA_FEATURE_BOOKMARK_V2)) {
		(void) zap_lookup(mos, snap->ds_object,
		    DS_FIELD_IVSET_GUID, sizeof (uint64_t), 1,
		    &zbm->zbm_ivset_guid);
	}

	if (spa_feature_is_enabled(spa, SPA_FEATURE_BOOKMARK_WRITTEN)) {
		zbm->zbm_flags = ZBM_FLAG_SNAPSHOT_EXISTS | ZBM_FLAG_HAS_FBN;
		zbm->zbm_referenced_bytes_refd = dsp->ds_referenced_bytes;
		zbm->zbm_compressed_bytes_refd = dsp->ds_compressed_bytes;
		zbm->zbm_uncompressed_bytes_refd = dsp->ds_uncompressed_bytes;

		dsl_dataset_t *nextds;
		VERIFY0(dsl_dataset_hold_obj(snap->ds_dir->dd_pool,
		    dsp->ds_next_snap_obj, FTAG, &nextds));
		dsl_deadlist_space(&nextds->ds_deadlist,
		    &zbm->zbm_referenced_freed_before_next_snap,
		    &zbm->zbm_compressed_freed_before_next_snap,
		    &zbm->zbm_uncompressed_freed_before_next_snap);
		dsl_dataset_rele(nextds, FTAG);
	} else {
		bzero(&zbm->zbm_flags,
		    sizeof (zfs_bookmark_phys_t) -
		    offsetof(zfs_bookmark_phys_t, zbm_flags));
	}
}

/*
 * Add dsl_bookmark_node_t `dbn` to the given dataset and increment appropriate
 * SPA feature counters.
 */
void
dsl_bookmark_node_add(dsl_dataset_t *hds, dsl_bookmark_node_t *dbn,
    dmu_tx_t *tx)
{
	dsl_pool_t *dp = dmu_tx_pool(tx);
	objset_t *mos = dp->dp_meta_objset;

	if (hds->ds_bookmarks_obj == 0) {
		hds->ds_bookmarks_obj = zap_create_norm(mos,
		    U8_TEXTPREP_TOUPPER, DMU_OTN_ZAP_METADATA, DMU_OT_NONE, 0,
		    tx);
		spa_feature_incr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx);

		dsl_dataset_zapify(hds, tx);
		VERIFY0(zap_add(mos, hds->ds_object,
		    DS_FIELD_BOOKMARK_NAMES,
		    sizeof (hds->ds_bookmarks_obj), 1,
		    &hds->ds_bookmarks_obj, tx));
	}

	avl_add(&hds->ds_bookmarks, dbn);

	/*
	 * To maintain backwards compatibility with software that doesn't
	 * understand SPA_FEATURE_BOOKMARK_V2, we need to use the smallest
	 * possible bookmark size.
	 */
	uint64_t bookmark_phys_size = BOOKMARK_PHYS_SIZE_V1;
	if (spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_BOOKMARK_V2) &&
	    (dbn->dbn_phys.zbm_ivset_guid != 0 || dbn->dbn_phys.zbm_flags &
	    ZBM_FLAG_HAS_FBN || dbn->dbn_phys.zbm_redaction_obj != 0)) {
		bookmark_phys_size = BOOKMARK_PHYS_SIZE_V2;
		spa_feature_incr(dp->dp_spa, SPA_FEATURE_BOOKMARK_V2, tx);
	}

	__attribute__((unused)) zfs_bookmark_phys_t zero_phys = { 0 };
	ASSERT0(bcmp(((char *)&dbn->dbn_phys) + bookmark_phys_size,
	    &zero_phys, sizeof (zfs_bookmark_phys_t) - bookmark_phys_size));

	VERIFY0(zap_add(mos, hds->ds_bookmarks_obj, dbn->dbn_name,
	    sizeof (uint64_t), bookmark_phys_size / sizeof (uint64_t),
	    &dbn->dbn_phys, tx));
}

/*
 * If redaction_list is non-null, we create a redacted bookmark and redaction
 * list, and store the object number of the redaction list in redact_obj.
 */
static void
dsl_bookmark_create_sync_impl_snap(const char *bookmark, const char *snapshot,
    dmu_tx_t *tx, uint64_t num_redact_snaps, uint64_t *redact_snaps, void *tag,
    redaction_list_t **redaction_list)
{
	dsl_pool_t *dp = dmu_tx_pool(tx);
	objset_t *mos = dp->dp_meta_objset;
	dsl_dataset_t *snapds, *bmark_fs;
	char *shortname;
	boolean_t bookmark_redacted;
	uint64_t *dsredactsnaps;
	uint64_t dsnumsnaps;

	VERIFY0(dsl_dataset_hold(dp, snapshot, FTAG, &snapds));
	VERIFY0(dsl_bookmark_hold_ds(dp, bookmark, &bmark_fs, FTAG,
	    &shortname));

	dsl_bookmark_node_t *dbn = dsl_bookmark_node_alloc(shortname);
	dsl_bookmark_set_phys(&dbn->dbn_phys, snapds);

	bookmark_redacted = dsl_dataset_get_uint64_array_feature(snapds,
	    SPA_FEATURE_REDACTED_DATASETS, &dsnumsnaps, &dsredactsnaps);
	if (redaction_list != NULL || bookmark_redacted) {
		redaction_list_t *local_rl;
		if (bookmark_redacted) {
			redact_snaps = dsredactsnaps;
			num_redact_snaps = dsnumsnaps;
		}
		dbn->dbn_phys.zbm_redaction_obj = dmu_object_alloc(mos,
		    DMU_OTN_UINT64_METADATA, SPA_OLD_MAXBLOCKSIZE,
		    DMU_OTN_UINT64_METADATA, sizeof (redaction_list_phys_t) +
		    num_redact_snaps * sizeof (uint64_t), tx);
		spa_feature_incr(dp->dp_spa,
		    SPA_FEATURE_REDACTION_BOOKMARKS, tx);

		VERIFY0(dsl_redaction_list_hold_obj(dp,
		    dbn->dbn_phys.zbm_redaction_obj, tag, &local_rl));
		dsl_redaction_list_long_hold(dp, local_rl, tag);

		ASSERT3U((local_rl)->rl_dbuf->db_size, >=,
		    sizeof (redaction_list_phys_t) + num_redact_snaps *
		    sizeof (uint64_t));
		dmu_buf_will_dirty(local_rl->rl_dbuf, tx);
		bcopy(redact_snaps, local_rl->rl_phys->rlp_snaps,
		    sizeof (uint64_t) * num_redact_snaps);
		local_rl->rl_phys->rlp_num_snaps = num_redact_snaps;
		if (bookmark_redacted) {
			ASSERT3P(redaction_list, ==, NULL);
			local_rl->rl_phys->rlp_last_blkid = UINT64_MAX;
			local_rl->rl_phys->rlp_last_object = UINT64_MAX;
			dsl_redaction_list_long_rele(local_rl, tag);
			dsl_redaction_list_rele(local_rl, tag);
		} else {
			*redaction_list = local_rl;
		}
	}

	if (dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN) {
		spa_feature_incr(dp->dp_spa,
		    SPA_FEATURE_BOOKMARK_WRITTEN, tx);
	}

	dsl_bookmark_node_add(bmark_fs, dbn, tx);

	spa_history_log_internal_ds(bmark_fs, "bookmark", tx,
	    "name=%s creation_txg=%llu target_snap=%llu redact_obj=%llu",
	    shortname, (longlong_t)dbn->dbn_phys.zbm_creation_txg,
	    (longlong_t)snapds->ds_object,
	    (longlong_t)dbn->dbn_phys.zbm_redaction_obj);

	dsl_dataset_rele(bmark_fs, FTAG);
	dsl_dataset_rele(snapds, FTAG);
}


static void
dsl_bookmark_create_sync_impl_book(
    const char *new_name, const char *source_name, dmu_tx_t *tx)
{
	dsl_pool_t *dp = dmu_tx_pool(tx);
	dsl_dataset_t *bmark_fs_source, *bmark_fs_new;
	char *source_shortname, *new_shortname;
	zfs_bookmark_phys_t source_phys;

	VERIFY0(dsl_bookmark_hold_ds(dp, source_name, &bmark_fs_source, FTAG,
	    &source_shortname));
	VERIFY0(dsl_bookmark_hold_ds(dp, new_name, &bmark_fs_new, FTAG,
	    &new_shortname));

	/*
	 * create a copy of the source bookmark by copying most of its members
	 *
	 * Caveat: bookmarking a redaction bookmark yields a normal bookmark
	 * -----------------------------------------------------------------
	 * Reasoning:
	 * - The zbm_redaction_obj would be referred to by both source and new
	 *   bookmark, but would be destroyed once either source or new is
	 *   destroyed, resulting in use-after-free of the referrred object.
	 * - User expectation when issuing the `zfs bookmark` command is that
	 *   a normal bookmark of the source is created
	 *
	 * Design Alternatives For Full Redaction Bookmark Copying:
	 * - reference-count the redaction object => would require on-disk
	 *   format change for existing redaction objects
	 * - Copy the redaction object => cannot be done in syncing context
	 *   because the redaction object might be too large
	 */

	VERIFY0(dsl_bookmark_lookup_impl(bmark_fs_source, source_shortname,
	    &source_phys));
	dsl_bookmark_node_t *new_dbn = dsl_bookmark_node_alloc(new_shortname);

	memcpy(&new_dbn->dbn_phys, &source_phys, sizeof (source_phys));
	new_dbn->dbn_phys.zbm_redaction_obj = 0;

	/* update feature counters */
	if (new_dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN) {
		spa_feature_incr(dp->dp_spa,
		    SPA_FEATURE_BOOKMARK_WRITTEN, tx);
	}
	/* no need for redaction bookmark counter; nulled zbm_redaction_obj */
	/* dsl_bookmark_node_add bumps bookmarks and v2-bookmarks counter */

	/*
	 * write new bookmark
	 *
	 * Note that dsl_bookmark_lookup_impl guarantees that, if source is a
	 * v1 bookmark, the v2-only fields are zeroed.
	 * And dsl_bookmark_node_add writes back a v1-sized bookmark if
	 * v2 bookmarks are disabled and/or v2-only fields are zeroed.
	 * => bookmark copying works on pre-bookmark-v2 pools
	 */
	dsl_bookmark_node_add(bmark_fs_new, new_dbn, tx);

	spa_history_log_internal_ds(bmark_fs_source, "bookmark", tx,
	    "name=%s creation_txg=%llu source_guid=%llu",
	    new_shortname, (longlong_t)new_dbn->dbn_phys.zbm_creation_txg,
	    (longlong_t)source_phys.zbm_guid);

	dsl_dataset_rele(bmark_fs_source, FTAG);
	dsl_dataset_rele(bmark_fs_new, FTAG);
}

void
dsl_bookmark_create_sync(void *arg, dmu_tx_t *tx)
{
	dsl_bookmark_create_arg_t *dbca = arg;

	ASSERT(spa_feature_is_enabled(dmu_tx_pool(tx)->dp_spa,
	    SPA_FEATURE_BOOKMARKS));

	for (nvpair_t *pair = nvlist_next_nvpair(dbca->dbca_bmarks, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(dbca->dbca_bmarks, pair)) {

		char *new = nvpair_name(pair);
		char *source = fnvpair_value_string(pair);

		if (strchr(source, '@') != NULL) {
			dsl_bookmark_create_sync_impl_snap(new, source, tx,
			    0, NULL, NULL, NULL);
		} else if (strchr(source, '#') != NULL) {
			dsl_bookmark_create_sync_impl_book(new, source, tx);
		} else {
			panic("unreachable code");
		}

	}
}

/*
 * The bookmarks must all be in the same pool.
 */
int
dsl_bookmark_create(nvlist_t *bmarks, nvlist_t *errors)
{
	nvpair_t *pair;
	dsl_bookmark_create_arg_t dbca;

	pair = nvlist_next_nvpair(bmarks, NULL);
	if (pair == NULL)
		return (0);

	dbca.dbca_bmarks = bmarks;
	dbca.dbca_errors = errors;

	return (dsl_sync_task(nvpair_name(pair), dsl_bookmark_create_check,
	    dsl_bookmark_create_sync, &dbca,
	    fnvlist_num_pairs(bmarks), ZFS_SPACE_CHECK_NORMAL));
}

static int
dsl_bookmark_create_redacted_check(void *arg, dmu_tx_t *tx)
{
	dsl_bookmark_create_redacted_arg_t *dbcra = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	int rv = 0;

	if (!spa_feature_is_enabled(dp->dp_spa,
	    SPA_FEATURE_REDACTION_BOOKMARKS))
		return (SET_ERROR(ENOTSUP));
	/*
	 * If the list of redact snaps will not fit in the bonus buffer with
	 * the furthest reached object and offset, fail.
	 */
	if (dbcra->dbcra_numsnaps > (dmu_bonus_max() -
	    sizeof (redaction_list_phys_t)) / sizeof (uint64_t))
		return (SET_ERROR(E2BIG));

	if (dsl_bookmark_create_nvl_validate_pair(
	    dbcra->dbcra_bmark, dbcra->dbcra_snap) != 0)
		return (SET_ERROR(EINVAL));

	rv = dsl_bookmark_create_check_impl(dp,
	    dbcra->dbcra_bmark, dbcra->dbcra_snap);
	return (rv);
}

static void
dsl_bookmark_create_redacted_sync(void *arg, dmu_tx_t *tx)
{
	dsl_bookmark_create_redacted_arg_t *dbcra = arg;
	dsl_bookmark_create_sync_impl_snap(dbcra->dbcra_bmark,
	    dbcra->dbcra_snap, tx, dbcra->dbcra_numsnaps, dbcra->dbcra_snaps,
	    dbcra->dbcra_tag, dbcra->dbcra_rl);
}

int
dsl_bookmark_create_redacted(const char *bookmark, const char *snapshot,
    uint64_t numsnaps, uint64_t *snapguids, void *tag, redaction_list_t **rl)
{
	dsl_bookmark_create_redacted_arg_t dbcra;

	dbcra.dbcra_bmark = bookmark;
	dbcra.dbcra_snap = snapshot;
	dbcra.dbcra_rl = rl;
	dbcra.dbcra_numsnaps = numsnaps;
	dbcra.dbcra_snaps = snapguids;
	dbcra.dbcra_tag = tag;

	return (dsl_sync_task(bookmark, dsl_bookmark_create_redacted_check,
	    dsl_bookmark_create_redacted_sync, &dbcra, 5,
	    ZFS_SPACE_CHECK_NORMAL));
}

/*
 * Retrieve the list of properties given in the 'props' nvlist for a bookmark.
 * If 'props' is NULL, retrieves all properties.
 */
static void
dsl_bookmark_fetch_props(dsl_pool_t *dp, zfs_bookmark_phys_t *bmark_phys,
    nvlist_t *props, nvlist_t *out_props)
{
	ASSERT3P(dp, !=, NULL);
	ASSERT3P(bmark_phys, !=, NULL);
	ASSERT3P(out_props, !=, NULL);
	ASSERT(RRW_LOCK_HELD(&dp->dp_config_rwlock));

	if (props == NULL || nvlist_exists(props,
	    zfs_prop_to_name(ZFS_PROP_GUID))) {
		dsl_prop_nvlist_add_uint64(out_props,
		    ZFS_PROP_GUID, bmark_phys->zbm_guid);
	}
	if (props == NULL || nvlist_exists(props,
	    zfs_prop_to_name(ZFS_PROP_CREATETXG))) {
		dsl_prop_nvlist_add_uint64(out_props,
		    ZFS_PROP_CREATETXG, bmark_phys->zbm_creation_txg);
	}
	if (props == NULL || nvlist_exists(props,
	    zfs_prop_to_name(ZFS_PROP_CREATION))) {
		dsl_prop_nvlist_add_uint64(out_props,
		    ZFS_PROP_CREATION, bmark_phys->zbm_creation_time);
	}
	if (props == NULL || nvlist_exists(props,
	    zfs_prop_to_name(ZFS_PROP_IVSET_GUID))) {
		dsl_prop_nvlist_add_uint64(out_props,
		    ZFS_PROP_IVSET_GUID, bmark_phys->zbm_ivset_guid);
	}
	if (bmark_phys->zbm_flags & ZBM_FLAG_HAS_FBN) {
		if (props == NULL || nvlist_exists(props,
		    zfs_prop_to_name(ZFS_PROP_REFERENCED))) {
			dsl_prop_nvlist_add_uint64(out_props,
			    ZFS_PROP_REFERENCED,
			    bmark_phys->zbm_referenced_bytes_refd);
		}
		if (props == NULL || nvlist_exists(props,
		    zfs_prop_to_name(ZFS_PROP_LOGICALREFERENCED))) {
			dsl_prop_nvlist_add_uint64(out_props,
			    ZFS_PROP_LOGICALREFERENCED,
			    bmark_phys->zbm_uncompressed_bytes_refd);
		}
		if (props == NULL || nvlist_exists(props,
		    zfs_prop_to_name(ZFS_PROP_REFRATIO))) {
			uint64_t ratio =
			    bmark_phys->zbm_compressed_bytes_refd == 0 ? 100 :
			    bmark_phys->zbm_uncompressed_bytes_refd * 100 /
			    bmark_phys->zbm_compressed_bytes_refd;
			dsl_prop_nvlist_add_uint64(out_props,
			    ZFS_PROP_REFRATIO, ratio);
		}
	}

	if ((props == NULL || nvlist_exists(props, "redact_snaps") ||
	    nvlist_exists(props, "redact_complete")) &&
	    bmark_phys->zbm_redaction_obj != 0) {
		redaction_list_t *rl;
		int err = dsl_redaction_list_hold_obj(dp,
		    bmark_phys->zbm_redaction_obj, FTAG, &rl);
		if (err == 0) {
			if (nvlist_exists(props, "redact_snaps")) {
				nvlist_t *nvl;
				nvl = fnvlist_alloc();
				fnvlist_add_uint64_array(nvl, ZPROP_VALUE,
				    rl->rl_phys->rlp_snaps,
				    rl->rl_phys->rlp_num_snaps);
				fnvlist_add_nvlist(out_props, "redact_snaps",
				    nvl);
				nvlist_free(nvl);
			}
			if (nvlist_exists(props, "redact_complete")) {
				nvlist_t *nvl;
				nvl = fnvlist_alloc();
				fnvlist_add_boolean_value(nvl, ZPROP_VALUE,
				    rl->rl_phys->rlp_last_blkid == UINT64_MAX &&
				    rl->rl_phys->rlp_last_object == UINT64_MAX);
				fnvlist_add_nvlist(out_props, "redact_complete",
				    nvl);
				nvlist_free(nvl);
			}
			dsl_redaction_list_rele(rl, FTAG);
		}
	}
}

int
dsl_get_bookmarks_impl(dsl_dataset_t *ds, nvlist_t *props, nvlist_t *outnvl)
{
	dsl_pool_t *dp = ds->ds_dir->dd_pool;

	ASSERT(dsl_pool_config_held(dp));

	if (dsl_dataset_is_snapshot(ds))
		return (SET_ERROR(EINVAL));

	for (dsl_bookmark_node_t *dbn = avl_first(&ds->ds_bookmarks);
	    dbn != NULL; dbn = AVL_NEXT(&ds->ds_bookmarks, dbn)) {
		nvlist_t *out_props = fnvlist_alloc();

		dsl_bookmark_fetch_props(dp, &dbn->dbn_phys, props, out_props);

		fnvlist_add_nvlist(outnvl, dbn->dbn_name, out_props);
		fnvlist_free(out_props);
	}
	return (0);
}

/*
 * Comparison func for ds_bookmarks AVL tree.  We sort the bookmarks by
 * their TXG, then by their FBN-ness.  The "FBN-ness" component ensures
 * that all bookmarks at the same TXG that HAS_FBN are adjacent, which
 * dsl_bookmark_destroy_sync_impl() depends on.  Note that there may be
 * multiple bookmarks at the same TXG (with the same FBN-ness).  In this
 * case we differentiate them by an arbitrary metric (in this case,
 * their names).
 */
static int
dsl_bookmark_compare(const void *l, const void *r)
{
	const dsl_bookmark_node_t *ldbn = l;
	const dsl_bookmark_node_t *rdbn = r;

	int64_t cmp = TREE_CMP(ldbn->dbn_phys.zbm_creation_txg,
	    rdbn->dbn_phys.zbm_creation_txg);
	if (likely(cmp))
		return (cmp);
	cmp = TREE_CMP((ldbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN),
	    (rdbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN));
	if (likely(cmp))
		return (cmp);
	cmp = strcmp(ldbn->dbn_name, rdbn->dbn_name);
	return (TREE_ISIGN(cmp));
}

/*
 * Cache this (head) dataset's bookmarks in the ds_bookmarks AVL tree.
 */
int
dsl_bookmark_init_ds(dsl_dataset_t *ds)
{
	dsl_pool_t *dp = ds->ds_dir->dd_pool;
	objset_t *mos = dp->dp_meta_objset;

	ASSERT(!ds->ds_is_snapshot);

	avl_create(&ds->ds_bookmarks, dsl_bookmark_compare,
	    sizeof (dsl_bookmark_node_t),
	    offsetof(dsl_bookmark_node_t, dbn_node));

	if (!dsl_dataset_is_zapified(ds))
		return (0);

	int zaperr = zap_lookup(mos, ds->ds_object, DS_FIELD_BOOKMARK_NAMES,
	    sizeof (ds->ds_bookmarks_obj), 1, &ds->ds_bookmarks_obj);
	if (zaperr == ENOENT)
		return (0);
	if (zaperr != 0)
		return (zaperr);

	if (ds->ds_bookmarks_obj == 0)
		return (0);

	int err = 0;
	zap_cursor_t zc;
	zap_attribute_t attr;

	for (zap_cursor_init(&zc, mos, ds->ds_bookmarks_obj);
	    (err = zap_cursor_retrieve(&zc, &attr)) == 0;
	    zap_cursor_advance(&zc)) {
		dsl_bookmark_node_t *dbn =
		    dsl_bookmark_node_alloc(attr.za_name);

		err = dsl_bookmark_lookup_impl(ds,
		    dbn->dbn_name, &dbn->dbn_phys);
		ASSERT3U(err, !=, ENOENT);
		if (err != 0) {
			kmem_free(dbn, sizeof (*dbn));
			break;
		}
		avl_add(&ds->ds_bookmarks, dbn);
	}
	zap_cursor_fini(&zc);
	if (err == ENOENT)
		err = 0;
	return (err);
}

void
dsl_bookmark_fini_ds(dsl_dataset_t *ds)
{
	void *cookie = NULL;
	dsl_bookmark_node_t *dbn;

	if (ds->ds_is_snapshot)
		return;

	while ((dbn = avl_destroy_nodes(&ds->ds_bookmarks, &cookie)) != NULL) {
		spa_strfree(dbn->dbn_name);
		mutex_destroy(&dbn->dbn_lock);
		kmem_free(dbn, sizeof (*dbn));
	}
	avl_destroy(&ds->ds_bookmarks);
}

/*
 * Retrieve the bookmarks that exist in the specified dataset, and the
 * requested properties of each bookmark.
 *
 * The "props" nvlist specifies which properties are requested.
 * See lzc_get_bookmarks() for the list of valid properties.
 */
int
dsl_get_bookmarks(const char *dsname, nvlist_t *props, nvlist_t *outnvl)
{
	dsl_pool_t *dp;
	dsl_dataset_t *ds;
	int err;

	err = dsl_pool_hold(dsname, FTAG, &dp);
	if (err != 0)
		return (err);
	err = dsl_dataset_hold(dp, dsname, FTAG, &ds);
	if (err != 0) {
		dsl_pool_rele(dp, FTAG);
		return (err);
	}

	err = dsl_get_bookmarks_impl(ds, props, outnvl);

	dsl_dataset_rele(ds, FTAG);
	dsl_pool_rele(dp, FTAG);
	return (err);
}

/*
 * Retrieve all properties for a single bookmark in the given dataset.
 */
int
dsl_get_bookmark_props(const char *dsname, const char *bmname, nvlist_t *props)
{
	dsl_pool_t *dp;
	dsl_dataset_t *ds;
	zfs_bookmark_phys_t bmark_phys = { 0 };
	int err;

	err = dsl_pool_hold(dsname, FTAG, &dp);
	if (err != 0)
		return (err);
	err = dsl_dataset_hold(dp, dsname, FTAG, &ds);
	if (err != 0) {
		dsl_pool_rele(dp, FTAG);
		return (err);
	}

	err = dsl_bookmark_lookup_impl(ds, bmname, &bmark_phys);
	if (err != 0)
		goto out;

	dsl_bookmark_fetch_props(dp, &bmark_phys, NULL, props);
out:
	dsl_dataset_rele(ds, FTAG);
	dsl_pool_rele(dp, FTAG);
	return (err);
}

typedef struct dsl_bookmark_destroy_arg {
	nvlist_t *dbda_bmarks;
	nvlist_t *dbda_success;
	nvlist_t *dbda_errors;
} dsl_bookmark_destroy_arg_t;

static void
dsl_bookmark_destroy_sync_impl(dsl_dataset_t *ds, const char *name,
    dmu_tx_t *tx)
{
	objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
	uint64_t bmark_zapobj = ds->ds_bookmarks_obj;
	matchtype_t mt = 0;
	uint64_t int_size, num_ints;
	/*
	 * 'search' must be zeroed so that dbn_flags (which is used in
	 * dsl_bookmark_compare()) will be zeroed even if the on-disk
	 * (in ZAP) bookmark is shorter than offsetof(dbn_flags).
	 */
	dsl_bookmark_node_t search = { 0 };
	char realname[ZFS_MAX_DATASET_NAME_LEN];

	/*
	 * Find the real name of this bookmark, which may be different
	 * from the given name if the dataset is case-insensitive.  Then
	 * use the real name to find the node in the ds_bookmarks AVL tree.
	 */

	if (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_CI_DATASET)
		mt = MT_NORMALIZE;

	VERIFY0(zap_length(mos, bmark_zapobj, name, &int_size, &num_ints));

	ASSERT3U(int_size, ==, sizeof (uint64_t));

	if (num_ints * int_size > BOOKMARK_PHYS_SIZE_V1) {
		spa_feature_decr(dmu_objset_spa(mos),
		    SPA_FEATURE_BOOKMARK_V2, tx);
	}
	VERIFY0(zap_lookup_norm(mos, bmark_zapobj, name, sizeof (uint64_t),
	    num_ints, &search.dbn_phys, mt, realname, sizeof (realname), NULL));

	search.dbn_name = realname;
	dsl_bookmark_node_t *dbn = avl_find(&ds->ds_bookmarks, &search, NULL);
	ASSERT(dbn != NULL);

	if (dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN) {
		/*
		 * If this bookmark HAS_FBN, and it is before the most
		 * recent snapshot, then its TXG is a key in the head's
		 * deadlist (and all clones' heads' deadlists).  If this is
		 * the last thing keeping the key (i.e. there are no more
		 * bookmarks with HAS_FBN at this TXG, and there is no
		 * snapshot at this TXG), then remove the key.
		 *
		 * Note that this algorithm depends on ds_bookmarks being
		 * sorted such that all bookmarks at the same TXG with
		 * HAS_FBN are adjacent (with no non-HAS_FBN bookmarks
		 * at the same TXG in between them).  If this were not
		 * the case, we would need to examine *all* bookmarks
		 * at this TXG, rather than just the adjacent ones.
		 */

		dsl_bookmark_node_t *dbn_prev =
		    AVL_PREV(&ds->ds_bookmarks, dbn);
		dsl_bookmark_node_t *dbn_next =
		    AVL_NEXT(&ds->ds_bookmarks, dbn);

		boolean_t more_bookmarks_at_this_txg =
		    (dbn_prev != NULL && dbn_prev->dbn_phys.zbm_creation_txg ==
		    dbn->dbn_phys.zbm_creation_txg &&
		    (dbn_prev->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN)) ||
		    (dbn_next != NULL && dbn_next->dbn_phys.zbm_creation_txg ==
		    dbn->dbn_phys.zbm_creation_txg &&
		    (dbn_next->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN));

		if (!(dbn->dbn_phys.zbm_flags & ZBM_FLAG_SNAPSHOT_EXISTS) &&
		    !more_bookmarks_at_this_txg &&
		    dbn->dbn_phys.zbm_creation_txg <
		    dsl_dataset_phys(ds)->ds_prev_snap_txg) {
			dsl_dir_remove_clones_key(ds->ds_dir,
			    dbn->dbn_phys.zbm_creation_txg, tx);
			dsl_deadlist_remove_key(&ds->ds_deadlist,
			    dbn->dbn_phys.zbm_creation_txg, tx);
		}

		spa_feature_decr(dmu_objset_spa(mos),
		    SPA_FEATURE_BOOKMARK_WRITTEN, tx);
	}

	if (dbn->dbn_phys.zbm_redaction_obj != 0) {
		VERIFY0(dmu_object_free(mos,
		    dbn->dbn_phys.zbm_redaction_obj, tx));
		spa_feature_decr(dmu_objset_spa(mos),
		    SPA_FEATURE_REDACTION_BOOKMARKS, tx);
	}

	avl_remove(&ds->ds_bookmarks, dbn);
	spa_strfree(dbn->dbn_name);
	mutex_destroy(&dbn->dbn_lock);
	kmem_free(dbn, sizeof (*dbn));

	VERIFY0(zap_remove_norm(mos, bmark_zapobj, name, mt, tx));
}

static int
dsl_bookmark_destroy_check(void *arg, dmu_tx_t *tx)
{
	dsl_bookmark_destroy_arg_t *dbda = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	int rv = 0;

	ASSERT(nvlist_empty(dbda->dbda_success));
	ASSERT(nvlist_empty(dbda->dbda_errors));

	if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_BOOKMARKS))
		return (0);

	for (nvpair_t *pair = nvlist_next_nvpair(dbda->dbda_bmarks, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(dbda->dbda_bmarks, pair)) {
		const char *fullname = nvpair_name(pair);
		dsl_dataset_t *ds;
		zfs_bookmark_phys_t bm;
		int error;
		char *shortname;

		error = dsl_bookmark_hold_ds(dp, fullname, &ds,
		    FTAG, &shortname);
		if (error == ENOENT) {
			/* ignore it; the bookmark is "already destroyed" */
			continue;
		}
		if (error == 0) {
			error = dsl_bookmark_lookup_impl(ds, shortname, &bm);
			dsl_dataset_rele(ds, FTAG);
			if (error == ESRCH) {
				/*
				 * ignore it; the bookmark is
				 * "already destroyed"
				 */
				continue;
			}
			if (error == 0 && bm.zbm_redaction_obj != 0) {
				redaction_list_t *rl = NULL;
				error = dsl_redaction_list_hold_obj(tx->tx_pool,
				    bm.zbm_redaction_obj, FTAG, &rl);
				if (error == ENOENT) {
					error = 0;
				} else if (error == 0 &&
				    dsl_redaction_list_long_held(rl)) {
					error = SET_ERROR(EBUSY);
				}
				if (rl != NULL) {
					dsl_redaction_list_rele(rl, FTAG);
				}
			}
		}
		if (error == 0) {
			if (dmu_tx_is_syncing(tx)) {
				fnvlist_add_boolean(dbda->dbda_success,
				    fullname);
			}
		} else {
			fnvlist_add_int32(dbda->dbda_errors, fullname, error);
			rv = error;
		}
	}
	return (rv);
}

static void
dsl_bookmark_destroy_sync(void *arg, dmu_tx_t *tx)
{
	dsl_bookmark_destroy_arg_t *dbda = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	objset_t *mos = dp->dp_meta_objset;

	for (nvpair_t *pair = nvlist_next_nvpair(dbda->dbda_success, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(dbda->dbda_success, pair)) {
		dsl_dataset_t *ds;
		char *shortname;
		uint64_t zap_cnt;

		VERIFY0(dsl_bookmark_hold_ds(dp, nvpair_name(pair),
		    &ds, FTAG, &shortname));
		dsl_bookmark_destroy_sync_impl(ds, shortname, tx);

		/*
		 * If all of this dataset's bookmarks have been destroyed,
		 * free the zap object and decrement the feature's use count.
		 */
		VERIFY0(zap_count(mos, ds->ds_bookmarks_obj, &zap_cnt));
		if (zap_cnt == 0) {
			dmu_buf_will_dirty(ds->ds_dbuf, tx);
			VERIFY0(zap_destroy(mos, ds->ds_bookmarks_obj, tx));
			ds->ds_bookmarks_obj = 0;
			spa_feature_decr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx);
			VERIFY0(zap_remove(mos, ds->ds_object,
			    DS_FIELD_BOOKMARK_NAMES, tx));
		}

		spa_history_log_internal_ds(ds, "remove bookmark", tx,
		    "name=%s", shortname);

		dsl_dataset_rele(ds, FTAG);
	}
}

/*
 * The bookmarks must all be in the same pool.
 */
int
dsl_bookmark_destroy(nvlist_t *bmarks, nvlist_t *errors)
{
	int rv;
	dsl_bookmark_destroy_arg_t dbda;
	nvpair_t *pair = nvlist_next_nvpair(bmarks, NULL);
	if (pair == NULL)
		return (0);

	dbda.dbda_bmarks = bmarks;
	dbda.dbda_errors = errors;
	dbda.dbda_success = fnvlist_alloc();

	rv = dsl_sync_task(nvpair_name(pair), dsl_bookmark_destroy_check,
	    dsl_bookmark_destroy_sync, &dbda, fnvlist_num_pairs(bmarks),
	    ZFS_SPACE_CHECK_RESERVED);
	fnvlist_free(dbda.dbda_success);
	return (rv);
}

/* Return B_TRUE if there are any long holds on this dataset. */
boolean_t
dsl_redaction_list_long_held(redaction_list_t *rl)
{
	return (!zfs_refcount_is_zero(&rl->rl_longholds));
}

void
dsl_redaction_list_long_hold(dsl_pool_t *dp, redaction_list_t *rl, void *tag)
{
	ASSERT(dsl_pool_config_held(dp));
	(void) zfs_refcount_add(&rl->rl_longholds, tag);
}

void
dsl_redaction_list_long_rele(redaction_list_t *rl, void *tag)
{
	(void) zfs_refcount_remove(&rl->rl_longholds, tag);
}

/* ARGSUSED */
static void
redaction_list_evict_sync(void *rlu)
{
	redaction_list_t *rl = rlu;
	zfs_refcount_destroy(&rl->rl_longholds);

	kmem_free(rl, sizeof (redaction_list_t));
}

void
dsl_redaction_list_rele(redaction_list_t *rl, void *tag)
{
	dmu_buf_rele(rl->rl_dbuf, tag);
}

int
dsl_redaction_list_hold_obj(dsl_pool_t *dp, uint64_t rlobj, void *tag,
    redaction_list_t **rlp)
{
	objset_t *mos = dp->dp_meta_objset;
	dmu_buf_t *dbuf;
	redaction_list_t *rl;
	int err;

	ASSERT(dsl_pool_config_held(dp));

	err = dmu_bonus_hold(mos, rlobj, tag, &dbuf);
	if (err != 0)
		return (err);

	rl = dmu_buf_get_user(dbuf);
	if (rl == NULL) {
		redaction_list_t *winner = NULL;

		rl = kmem_zalloc(sizeof (redaction_list_t), KM_SLEEP);
		rl->rl_dbuf = dbuf;
		rl->rl_object = rlobj;
		rl->rl_phys = dbuf->db_data;
		rl->rl_mos = dp->dp_meta_objset;
		zfs_refcount_create(&rl->rl_longholds);
		dmu_buf_init_user(&rl->rl_dbu, redaction_list_evict_sync, NULL,
		    &rl->rl_dbuf);
		if ((winner = dmu_buf_set_user_ie(dbuf, &rl->rl_dbu)) != NULL) {
			kmem_free(rl, sizeof (*rl));
			rl = winner;
		}
	}
	*rlp = rl;
	return (0);
}

/*
 * Snapshot ds is being destroyed.
 *
 * Adjust the "freed_before_next" of any bookmarks between this snap
 * and the previous snapshot, because their "next snapshot" is changing.
 *
 * If there are any bookmarks with HAS_FBN at this snapshot, remove
 * their HAS_SNAP flag (note: there can be at most one snapshot of
 * each filesystem at a given txg), and return B_TRUE.  In this case
 * the caller can not remove the key in the deadlist at this TXG, because
 * the HAS_FBN bookmarks require the key be there.
 *
 * Returns B_FALSE if there are no bookmarks with HAS_FBN at this
 * snapshot's TXG.  In this case the caller can remove the key in the
 * deadlist at this TXG.
 */
boolean_t
dsl_bookmark_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx)
{
	dsl_pool_t *dp = ds->ds_dir->dd_pool;

	dsl_dataset_t *head, *next;
	VERIFY0(dsl_dataset_hold_obj(dp,
	    dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &head));
	VERIFY0(dsl_dataset_hold_obj(dp,
	    dsl_dataset_phys(ds)->ds_next_snap_obj, FTAG, &next));

	/*
	 * Find the first bookmark that HAS_FBN at or after the
	 * previous snapshot.
	 */
	dsl_bookmark_node_t search = { 0 };
	avl_index_t idx;
	search.dbn_phys.zbm_creation_txg =
	    dsl_dataset_phys(ds)->ds_prev_snap_txg;
	search.dbn_phys.zbm_flags = ZBM_FLAG_HAS_FBN;
	/*
	 * The empty-string name can't be in the AVL, and it compares
	 * before any entries with this TXG.
	 */
	search.dbn_name = "";
	VERIFY3P(avl_find(&head->ds_bookmarks, &search, &idx), ==, NULL);
	dsl_bookmark_node_t *dbn =
	    avl_nearest(&head->ds_bookmarks, idx, AVL_AFTER);

	/*
	 * Iterate over all bookmarks that are at or after the previous
	 * snapshot, and before this (being deleted) snapshot.  Adjust
	 * their FBN based on their new next snapshot.
	 */
	for (; dbn != NULL && dbn->dbn_phys.zbm_creation_txg <
	    dsl_dataset_phys(ds)->ds_creation_txg;
	    dbn = AVL_NEXT(&head->ds_bookmarks, dbn)) {
		if (!(dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN))
			continue;
		/*
		 * Increase our FBN by the amount of space that was live
		 * (referenced) at the time of this bookmark (i.e.
		 * birth <= zbm_creation_txg), and killed between this
		 * (being deleted) snapshot and the next snapshot (i.e.
		 * on the next snapshot's deadlist).  (Space killed before
		 * this are already on our FBN.)
		 */
		uint64_t referenced, compressed, uncompressed;
		dsl_deadlist_space_range(&next->ds_deadlist,
		    0, dbn->dbn_phys.zbm_creation_txg,
		    &referenced, &compressed, &uncompressed);
		dbn->dbn_phys.zbm_referenced_freed_before_next_snap +=
		    referenced;
		dbn->dbn_phys.zbm_compressed_freed_before_next_snap +=
		    compressed;
		dbn->dbn_phys.zbm_uncompressed_freed_before_next_snap +=
		    uncompressed;
		VERIFY0(zap_update(dp->dp_meta_objset, head->ds_bookmarks_obj,
		    dbn->dbn_name, sizeof (uint64_t),
		    sizeof (zfs_bookmark_phys_t) / sizeof (uint64_t),
		    &dbn->dbn_phys, tx));
	}
	dsl_dataset_rele(next, FTAG);

	/*
	 * There may be several bookmarks at this txg (the TXG of the
	 * snapshot being deleted).  We need to clear the SNAPSHOT_EXISTS
	 * flag on all of them, and return TRUE if there is at least 1
	 * bookmark here with HAS_FBN (thus preventing the deadlist
	 * key from being removed).
	 */
	boolean_t rv = B_FALSE;
	for (; dbn != NULL && dbn->dbn_phys.zbm_creation_txg ==
	    dsl_dataset_phys(ds)->ds_creation_txg;
	    dbn = AVL_NEXT(&head->ds_bookmarks, dbn)) {
		if (!(dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN)) {
			ASSERT(!(dbn->dbn_phys.zbm_flags &
			    ZBM_FLAG_SNAPSHOT_EXISTS));
			continue;
		}
		ASSERT(dbn->dbn_phys.zbm_flags & ZBM_FLAG_SNAPSHOT_EXISTS);
		dbn->dbn_phys.zbm_flags &= ~ZBM_FLAG_SNAPSHOT_EXISTS;
		VERIFY0(zap_update(dp->dp_meta_objset, head->ds_bookmarks_obj,
		    dbn->dbn_name, sizeof (uint64_t),
		    sizeof (zfs_bookmark_phys_t) / sizeof (uint64_t),
		    &dbn->dbn_phys, tx));
		rv = B_TRUE;
	}
	dsl_dataset_rele(head, FTAG);
	return (rv);
}

/*
 * A snapshot is being created of this (head) dataset.
 *
 * We don't keep keys in the deadlist for the most recent snapshot, or any
 * bookmarks at or after it, because there can't be any blocks on the
 * deadlist in this range.  Now that the most recent snapshot is after
 * all bookmarks, we need to add these keys.  Note that the caller always
 * adds a key at the previous snapshot, so we only add keys for bookmarks
 * after that.
 */
void
dsl_bookmark_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx)
{
	uint64_t last_key_added = UINT64_MAX;
	for (dsl_bookmark_node_t *dbn = avl_last(&ds->ds_bookmarks);
	    dbn != NULL && dbn->dbn_phys.zbm_creation_txg >
	    dsl_dataset_phys(ds)->ds_prev_snap_txg;
	    dbn = AVL_PREV(&ds->ds_bookmarks, dbn)) {
		uint64_t creation_txg = dbn->dbn_phys.zbm_creation_txg;
		ASSERT3U(creation_txg, <=, last_key_added);
		/*
		 * Note, there may be multiple bookmarks at this TXG,
		 * and we only want to add the key for this TXG once.
		 * The ds_bookmarks AVL is sorted by TXG, so we will visit
		 * these bookmarks in sequence.
		 */
		if ((dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN) &&
		    creation_txg != last_key_added) {
			dsl_deadlist_add_key(&ds->ds_deadlist,
			    creation_txg, tx);
			last_key_added = creation_txg;
		}
	}
}

/*
 * The next snapshot of the origin dataset has changed, due to
 * promote or clone swap.  If there are any bookmarks at this dataset,
 * we need to update their zbm_*_freed_before_next_snap to reflect this.
 * The head dataset has the relevant bookmarks in ds_bookmarks.
 */
void
dsl_bookmark_next_changed(dsl_dataset_t *head, dsl_dataset_t *origin,
    dmu_tx_t *tx)
{
	dsl_pool_t *dp = dmu_tx_pool(tx);

	/*
	 * Find the first bookmark that HAS_FBN at the origin snapshot.
	 */
	dsl_bookmark_node_t search = { 0 };
	avl_index_t idx;
	search.dbn_phys.zbm_creation_txg =
	    dsl_dataset_phys(origin)->ds_creation_txg;
	search.dbn_phys.zbm_flags = ZBM_FLAG_HAS_FBN;
	/*
	 * The empty-string name can't be in the AVL, and it compares
	 * before any entries with this TXG.
	 */
	search.dbn_name = "";
	VERIFY3P(avl_find(&head->ds_bookmarks, &search, &idx), ==, NULL);
	dsl_bookmark_node_t *dbn =
	    avl_nearest(&head->ds_bookmarks, idx, AVL_AFTER);

	/*
	 * Iterate over all bookmarks that are at the origin txg.
	 * Adjust their FBN based on their new next snapshot.
	 */
	for (; dbn != NULL && dbn->dbn_phys.zbm_creation_txg ==
	    dsl_dataset_phys(origin)->ds_creation_txg &&
	    (dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN);
	    dbn = AVL_NEXT(&head->ds_bookmarks, dbn)) {

		/*
		 * Bookmark is at the origin, therefore its
		 * "next dataset" is changing, so we need
		 * to reset its FBN by recomputing it in
		 * dsl_bookmark_set_phys().
		 */
		ASSERT3U(dbn->dbn_phys.zbm_guid, ==,
		    dsl_dataset_phys(origin)->ds_guid);
		ASSERT3U(dbn->dbn_phys.zbm_referenced_bytes_refd, ==,
		    dsl_dataset_phys(origin)->ds_referenced_bytes);
		ASSERT(dbn->dbn_phys.zbm_flags &
		    ZBM_FLAG_SNAPSHOT_EXISTS);
		/*
		 * Save and restore the zbm_redaction_obj, which
		 * is zeroed by dsl_bookmark_set_phys().
		 */
		uint64_t redaction_obj =
		    dbn->dbn_phys.zbm_redaction_obj;
		dsl_bookmark_set_phys(&dbn->dbn_phys, origin);
		dbn->dbn_phys.zbm_redaction_obj = redaction_obj;

		VERIFY0(zap_update(dp->dp_meta_objset, head->ds_bookmarks_obj,
		    dbn->dbn_name, sizeof (uint64_t),
		    sizeof (zfs_bookmark_phys_t) / sizeof (uint64_t),
		    &dbn->dbn_phys, tx));
	}
}

/*
 * This block is no longer referenced by this (head) dataset.
 *
 * Adjust the FBN of any bookmarks that reference this block, whose "next"
 * is the head dataset.
 */
/* ARGSUSED */
void
dsl_bookmark_block_killed(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
{
	/*
	 * Iterate over bookmarks whose "next" is the head dataset.
	 */
	for (dsl_bookmark_node_t *dbn = avl_last(&ds->ds_bookmarks);
	    dbn != NULL && dbn->dbn_phys.zbm_creation_txg >=
	    dsl_dataset_phys(ds)->ds_prev_snap_txg;
	    dbn = AVL_PREV(&ds->ds_bookmarks, dbn)) {
		/*
		 * If the block was live (referenced) at the time of this
		 * bookmark, add its space to the bookmark's FBN.
		 */
		if (bp->blk_birth <= dbn->dbn_phys.zbm_creation_txg &&
		    (dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN)) {
			mutex_enter(&dbn->dbn_lock);
			dbn->dbn_phys.zbm_referenced_freed_before_next_snap +=
			    bp_get_dsize_sync(dsl_dataset_get_spa(ds), bp);
			dbn->dbn_phys.zbm_compressed_freed_before_next_snap +=
			    BP_GET_PSIZE(bp);
			dbn->dbn_phys.zbm_uncompressed_freed_before_next_snap +=
			    BP_GET_UCSIZE(bp);
			/*
			 * Changing the ZAP object here would be too
			 * expensive.  Also, we may be called from the zio
			 * interrupt thread, which can't block on i/o.
			 * Therefore, we mark this bookmark as dirty and
			 * modify the ZAP once per txg, in
			 * dsl_bookmark_sync_done().
			 */
			dbn->dbn_dirty = B_TRUE;
			mutex_exit(&dbn->dbn_lock);
		}
	}
}

void
dsl_bookmark_sync_done(dsl_dataset_t *ds, dmu_tx_t *tx)
{
	dsl_pool_t *dp = dmu_tx_pool(tx);

	if (dsl_dataset_is_snapshot(ds))
		return;

	/*
	 * We only dirty bookmarks that are at or after the most recent
	 * snapshot.  We can't create snapshots between
	 * dsl_bookmark_block_killed() and dsl_bookmark_sync_done(), so we
	 * don't need to look at any bookmarks before ds_prev_snap_txg.
	 */
	for (dsl_bookmark_node_t *dbn = avl_last(&ds->ds_bookmarks);
	    dbn != NULL && dbn->dbn_phys.zbm_creation_txg >=
	    dsl_dataset_phys(ds)->ds_prev_snap_txg;
	    dbn = AVL_PREV(&ds->ds_bookmarks, dbn)) {
		if (dbn->dbn_dirty) {
			/*
			 * We only dirty nodes with HAS_FBN, therefore
			 * we can always use the current bookmark struct size.
			 */
			ASSERT(dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN);
			VERIFY0(zap_update(dp->dp_meta_objset,
			    ds->ds_bookmarks_obj,
			    dbn->dbn_name, sizeof (uint64_t),
			    sizeof (zfs_bookmark_phys_t) / sizeof (uint64_t),
			    &dbn->dbn_phys, tx));
			dbn->dbn_dirty = B_FALSE;
		}
	}
#ifdef ZFS_DEBUG
	for (dsl_bookmark_node_t *dbn = avl_first(&ds->ds_bookmarks);
	    dbn != NULL; dbn = AVL_NEXT(&ds->ds_bookmarks, dbn)) {
		ASSERT(!dbn->dbn_dirty);
	}
#endif
}

/*
 * Return the TXG of the most recent bookmark (or 0 if there are no bookmarks).
 */
uint64_t
dsl_bookmark_latest_txg(dsl_dataset_t *ds)
{
	ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
	dsl_bookmark_node_t *dbn = avl_last(&ds->ds_bookmarks);
	if (dbn == NULL)
		return (0);
	return (dbn->dbn_phys.zbm_creation_txg);
}

static inline unsigned int
redact_block_buf_num_entries(unsigned int size)
{
	return (size / sizeof (redact_block_phys_t));
}

/*
 * This function calculates the offset of the last entry in the array of
 * redact_block_phys_t.  If we're reading the redaction list into buffers of
 * size bufsize, then for all but the last buffer, the last valid entry in the
 * array will be the last entry in the array.  However, for the last buffer, any
 * amount of it may be filled.  Thus, we check to see if we're looking at the
 * last buffer in the redaction list, and if so, we return the total number of
 * entries modulo the number of entries per buffer.  Otherwise, we return the
 * number of entries per buffer minus one.
 */
static inline unsigned int
last_entry(redaction_list_t *rl, unsigned int bufsize, uint64_t bufid)
{
	if (bufid == (rl->rl_phys->rlp_num_entries - 1) /
	    redact_block_buf_num_entries(bufsize)) {
		return ((rl->rl_phys->rlp_num_entries - 1) %
		    redact_block_buf_num_entries(bufsize));
	}
	return (redact_block_buf_num_entries(bufsize) - 1);
}

/*
 * Compare the redact_block_phys_t to the bookmark. If the last block in the
 * redact_block_phys_t is before the bookmark, return -1.  If the first block in
 * the redact_block_phys_t is after the bookmark, return 1.  Otherwise, the
 * bookmark is inside the range of the redact_block_phys_t, and we return 0.
 */
static int
redact_block_zb_compare(redact_block_phys_t *first,
    zbookmark_phys_t *second)
{
	/*
	 * If the block_phys is for a previous object, or the last block in the
	 * block_phys is strictly before the block in the bookmark, the
	 * block_phys is earlier.
	 */
	if (first->rbp_object < second->zb_object ||
	    (first->rbp_object == second->zb_object &&
	    first->rbp_blkid + (redact_block_get_count(first) - 1) <
	    second->zb_blkid)) {
		return (-1);
	}

	/*
	 * If the bookmark is for a previous object, or the block in the
	 * bookmark is strictly before the first block in the block_phys, the
	 * bookmark is earlier.
	 */
	if (first->rbp_object > second->zb_object ||
	    (first->rbp_object == second->zb_object &&
	    first->rbp_blkid > second->zb_blkid)) {
		return (1);
	}

	return (0);
}

/*
 * Traverse the redaction list in the provided object, and call the callback for
 * each entry we find. Don't call the callback for any records before resume.
 */
int
dsl_redaction_list_traverse(redaction_list_t *rl, zbookmark_phys_t *resume,
    rl_traverse_callback_t cb, void *arg)
{
	objset_t *mos = rl->rl_mos;
	redact_block_phys_t *buf;
	unsigned int bufsize = SPA_OLD_MAXBLOCKSIZE;
	int err = 0;

	if (rl->rl_phys->rlp_last_object != UINT64_MAX ||
	    rl->rl_phys->rlp_last_blkid != UINT64_MAX) {
		/*
		 * When we finish a send, we update the last object and offset
		 * to UINT64_MAX.  If a send fails partway through, the last
		 * object and offset will have some other value, indicating how
		 * far the send got. The redaction list must be complete before
		 * it can be traversed, so return EINVAL if the last object and
		 * blkid are not set to UINT64_MAX.
		 */
		return (SET_ERROR(EINVAL));
	}

	/*
	 * Binary search for the point to resume from.  The goal is to minimize
	 * the number of disk reads we have to perform.
	 */
	buf = zio_data_buf_alloc(bufsize);
	uint64_t maxbufid = (rl->rl_phys->rlp_num_entries - 1) /
	    redact_block_buf_num_entries(bufsize);
	uint64_t minbufid = 0;
	while (resume != NULL && maxbufid - minbufid >= 1) {
		ASSERT3U(maxbufid, >, minbufid);
		uint64_t midbufid = minbufid + ((maxbufid - minbufid) / 2);
		err = dmu_read(mos, rl->rl_object, midbufid * bufsize, bufsize,
		    buf, DMU_READ_NO_PREFETCH);
		if (err != 0)
			break;

		int cmp0 = redact_block_zb_compare(&buf[0], resume);
		int cmpn = redact_block_zb_compare(
		    &buf[last_entry(rl, bufsize, maxbufid)], resume);

		/*
		 * If the first block is before or equal to the resume point,
		 * and the last one is equal or after, then the resume point is
		 * in this buf, and we should start here.
		 */
		if (cmp0 <= 0 && cmpn >= 0)
			break;

		if (cmp0 > 0)
			maxbufid = midbufid - 1;
		else if (cmpn < 0)
			minbufid = midbufid + 1;
		else
			panic("No progress in binary search for resume point");
	}

	for (uint64_t curidx = minbufid * redact_block_buf_num_entries(bufsize);
	    err == 0 && curidx < rl->rl_phys->rlp_num_entries;
	    curidx++) {
		/*
		 * We read in the redaction list one block at a time.  Once we
		 * finish with all the entries in a given block, we read in a
		 * new one.  The predictive prefetcher will take care of any
		 * prefetching, and this code shouldn't be the bottleneck, so we
		 * don't need to do manual prefetching.
		 */
		if (curidx % redact_block_buf_num_entries(bufsize) == 0) {
			err = dmu_read(mos, rl->rl_object, curidx *
			    sizeof (*buf), bufsize, buf,
			    DMU_READ_PREFETCH);
			if (err != 0)
				break;
		}
		redact_block_phys_t *rb = &buf[curidx %
		    redact_block_buf_num_entries(bufsize)];
		/*
		 * If resume is non-null, we should either not send the data, or
		 * null out resume so we don't have to keep doing these
		 * comparisons.
		 */
		if (resume != NULL) {
			if (redact_block_zb_compare(rb, resume) < 0) {
				continue;
			} else {
				/*
				 * If the place to resume is in the middle of
				 * the range described by this
				 * redact_block_phys, then modify the
				 * redact_block_phys in memory so we generate
				 * the right records.
				 */
				if (resume->zb_object == rb->rbp_object &&
				    resume->zb_blkid > rb->rbp_blkid) {
					uint64_t diff = resume->zb_blkid -
					    rb->rbp_blkid;
					rb->rbp_blkid = resume->zb_blkid;
					redact_block_set_count(rb,
					    redact_block_get_count(rb) - diff);
				}
				resume = NULL;
			}
		}

		if (cb(rb, arg) != 0)
			break;
	}

	zio_data_buf_free(buf, bufsize);
	return (err);
}