summaryrefslogtreecommitdiff
path: root/fs/btrfs/tree-checker.c
blob: 493d4d9e0f79c8292b4efc6c3b5632ed91b95cb5 (plain)
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
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) Qu Wenruo 2017.  All rights reserved.
 */

/*
 * The module is used to catch unexpected/corrupted tree block data.
 * Such behavior can be caused either by a fuzzed image or bugs.
 *
 * The objective is to do leaf/node validation checks when tree block is read
 * from disk, and check *every* possible member, so other code won't
 * need to checking them again.
 *
 * Due to the potential and unwanted damage, every checker needs to be
 * carefully reviewed otherwise so it does not prevent mount of valid images.
 */

#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/error-injection.h>
#include "ctree.h"
#include "tree-checker.h"
#include "disk-io.h"
#include "compression.h"
#include "volumes.h"
#include "misc.h"

/*
 * Error message should follow the following format:
 * corrupt <type>: <identifier>, <reason>[, <bad_value>]
 *
 * @type:	leaf or node
 * @identifier:	the necessary info to locate the leaf/node.
 * 		It's recommended to decode key.objecitd/offset if it's
 * 		meaningful.
 * @reason:	describe the error
 * @bad_value:	optional, it's recommended to output bad value and its
 *		expected value (range).
 *
 * Since comma is used to separate the components, only space is allowed
 * inside each component.
 */

/*
 * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
 * Allows callers to customize the output.
 */
__printf(3, 4)
__cold
static void generic_err(const struct extent_buffer *eb, int slot,
			const char *fmt, ...)
{
	const struct btrfs_fs_info *fs_info = eb->fs_info;
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(fs_info,
		"corrupt %s: root=%llu block=%llu slot=%d, %pV",
		btrfs_header_level(eb) == 0 ? "leaf" : "node",
		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, &vaf);
	va_end(args);
}

/*
 * Customized reporter for extent data item, since its key objectid and
 * offset has its own meaning.
 */
__printf(3, 4)
__cold
static void file_extent_err(const struct extent_buffer *eb, int slot,
			    const char *fmt, ...)
{
	const struct btrfs_fs_info *fs_info = eb->fs_info;
	struct btrfs_key key;
	struct va_format vaf;
	va_list args;

	btrfs_item_key_to_cpu(eb, &key, slot);
	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(fs_info,
	"corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV",
		btrfs_header_level(eb) == 0 ? "leaf" : "node",
		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
		key.objectid, key.offset, &vaf);
	va_end(args);
}

/*
 * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
 * Else return 1
 */
#define CHECK_FE_ALIGNED(leaf, slot, fi, name, alignment)		      \
({									      \
	if (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))) \
		file_extent_err((leaf), (slot),				      \
	"invalid %s for file extent, have %llu, should be aligned to %u",     \
			(#name), btrfs_file_extent_##name((leaf), (fi)),      \
			(alignment));					      \
	(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment)));   \
})

static u64 file_extent_end(struct extent_buffer *leaf,
			   struct btrfs_key *key,
			   struct btrfs_file_extent_item *extent)
{
	u64 end;
	u64 len;

	if (btrfs_file_extent_type(leaf, extent) == BTRFS_FILE_EXTENT_INLINE) {
		len = btrfs_file_extent_ram_bytes(leaf, extent);
		end = ALIGN(key->offset + len, leaf->fs_info->sectorsize);
	} else {
		len = btrfs_file_extent_num_bytes(leaf, extent);
		end = key->offset + len;
	}
	return end;
}

/*
 * Customized report for dir_item, the only new important information is
 * key->objectid, which represents inode number
 */
__printf(3, 4)
__cold
static void dir_item_err(const struct extent_buffer *eb, int slot,
			 const char *fmt, ...)
{
	const struct btrfs_fs_info *fs_info = eb->fs_info;
	struct btrfs_key key;
	struct va_format vaf;
	va_list args;

	btrfs_item_key_to_cpu(eb, &key, slot);
	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(fs_info,
		"corrupt %s: root=%llu block=%llu slot=%d ino=%llu, %pV",
		btrfs_header_level(eb) == 0 ? "leaf" : "node",
		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
		key.objectid, &vaf);
	va_end(args);
}

/*
 * This functions checks prev_key->objectid, to ensure current key and prev_key
 * share the same objectid as inode number.
 *
 * This is to detect missing INODE_ITEM in subvolume trees.
 *
 * Return true if everything is OK or we don't need to check.
 * Return false if anything is wrong.
 */
static bool check_prev_ino(struct extent_buffer *leaf,
			   struct btrfs_key *key, int slot,
			   struct btrfs_key *prev_key)
{
	/* No prev key, skip check */
	if (slot == 0)
		return true;

	/* Only these key->types needs to be checked */
	ASSERT(key->type == BTRFS_XATTR_ITEM_KEY ||
	       key->type == BTRFS_INODE_REF_KEY ||
	       key->type == BTRFS_DIR_INDEX_KEY ||
	       key->type == BTRFS_DIR_ITEM_KEY ||
	       key->type == BTRFS_EXTENT_DATA_KEY);

	/*
	 * Only subvolume trees along with their reloc trees need this check.
	 * Things like log tree doesn't follow this ino requirement.
	 */
	if (!is_fstree(btrfs_header_owner(leaf)))
		return true;

	if (key->objectid == prev_key->objectid)
		return true;

	/* Error found */
	dir_item_err(leaf, slot,
		"invalid previous key objectid, have %llu expect %llu",
		prev_key->objectid, key->objectid);
	return false;
}
static int check_extent_data_item(struct extent_buffer *leaf,
				  struct btrfs_key *key, int slot,
				  struct btrfs_key *prev_key)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	struct btrfs_file_extent_item *fi;
	u32 sectorsize = fs_info->sectorsize;
	u32 item_size = btrfs_item_size_nr(leaf, slot);
	u64 extent_end;

	if (!IS_ALIGNED(key->offset, sectorsize)) {
		file_extent_err(leaf, slot,
"unaligned file_offset for file extent, have %llu should be aligned to %u",
			key->offset, sectorsize);
		return -EUCLEAN;
	}

	/*
	 * Previous key must have the same key->objectid (ino).
	 * It can be XATTR_ITEM, INODE_ITEM or just another EXTENT_DATA.
	 * But if objectids mismatch, it means we have a missing
	 * INODE_ITEM.
	 */
	if (!check_prev_ino(leaf, key, slot, prev_key))
		return -EUCLEAN;

	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);

	/*
	 * Make sure the item contains at least inline header, so the file
	 * extent type is not some garbage.
	 */
	if (item_size < BTRFS_FILE_EXTENT_INLINE_DATA_START) {
		file_extent_err(leaf, slot,
				"invalid item size, have %u expect [%lu, %u)",
				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START,
				SZ_4K);
		return -EUCLEAN;
	}
	if (btrfs_file_extent_type(leaf, fi) >= BTRFS_NR_FILE_EXTENT_TYPES) {
		file_extent_err(leaf, slot,
		"invalid type for file extent, have %u expect range [0, %u]",
			btrfs_file_extent_type(leaf, fi),
			BTRFS_NR_FILE_EXTENT_TYPES - 1);
		return -EUCLEAN;
	}

	/*
	 * Support for new compression/encryption must introduce incompat flag,
	 * and must be caught in open_ctree().
	 */
	if (btrfs_file_extent_compression(leaf, fi) >= BTRFS_NR_COMPRESS_TYPES) {
		file_extent_err(leaf, slot,
	"invalid compression for file extent, have %u expect range [0, %u]",
			btrfs_file_extent_compression(leaf, fi),
			BTRFS_NR_COMPRESS_TYPES - 1);
		return -EUCLEAN;
	}
	if (btrfs_file_extent_encryption(leaf, fi)) {
		file_extent_err(leaf, slot,
			"invalid encryption for file extent, have %u expect 0",
			btrfs_file_extent_encryption(leaf, fi));
		return -EUCLEAN;
	}
	if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
		/* Inline extent must have 0 as key offset */
		if (key->offset) {
			file_extent_err(leaf, slot,
		"invalid file_offset for inline file extent, have %llu expect 0",
				key->offset);
			return -EUCLEAN;
		}

		/* Compressed inline extent has no on-disk size, skip it */
		if (btrfs_file_extent_compression(leaf, fi) !=
		    BTRFS_COMPRESS_NONE)
			return 0;

		/* Uncompressed inline extent size must match item size */
		if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
		    btrfs_file_extent_ram_bytes(leaf, fi)) {
			file_extent_err(leaf, slot,
	"invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
				btrfs_file_extent_ram_bytes(leaf, fi));
			return -EUCLEAN;
		}
		return 0;
	}

	/* Regular or preallocated extent has fixed item size */
	if (item_size != sizeof(*fi)) {
		file_extent_err(leaf, slot,
	"invalid item size for reg/prealloc file extent, have %u expect %zu",
			item_size, sizeof(*fi));
		return -EUCLEAN;
	}
	if (CHECK_FE_ALIGNED(leaf, slot, fi, ram_bytes, sectorsize) ||
	    CHECK_FE_ALIGNED(leaf, slot, fi, disk_bytenr, sectorsize) ||
	    CHECK_FE_ALIGNED(leaf, slot, fi, disk_num_bytes, sectorsize) ||
	    CHECK_FE_ALIGNED(leaf, slot, fi, offset, sectorsize) ||
	    CHECK_FE_ALIGNED(leaf, slot, fi, num_bytes, sectorsize))
		return -EUCLEAN;

	/* Catch extent end overflow */
	if (check_add_overflow(btrfs_file_extent_num_bytes(leaf, fi),
			       key->offset, &extent_end)) {
		file_extent_err(leaf, slot,
	"extent end overflow, have file offset %llu extent num bytes %llu",
				key->offset,
				btrfs_file_extent_num_bytes(leaf, fi));
		return -EUCLEAN;
	}

	/*
	 * Check that no two consecutive file extent items, in the same leaf,
	 * present ranges that overlap each other.
	 */
	if (slot > 0 &&
	    prev_key->objectid == key->objectid &&
	    prev_key->type == BTRFS_EXTENT_DATA_KEY) {
		struct btrfs_file_extent_item *prev_fi;
		u64 prev_end;

		prev_fi = btrfs_item_ptr(leaf, slot - 1,
					 struct btrfs_file_extent_item);
		prev_end = file_extent_end(leaf, prev_key, prev_fi);
		if (prev_end > key->offset) {
			file_extent_err(leaf, slot - 1,
"file extent end range (%llu) goes beyond start offset (%llu) of the next file extent",
					prev_end, key->offset);
			return -EUCLEAN;
		}
	}

	return 0;
}

static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
			   int slot)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	u32 sectorsize = fs_info->sectorsize;
	u32 csumsize = btrfs_super_csum_size(fs_info->super_copy);

	if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) {
		generic_err(leaf, slot,
		"invalid key objectid for csum item, have %llu expect %llu",
			key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
		return -EUCLEAN;
	}
	if (!IS_ALIGNED(key->offset, sectorsize)) {
		generic_err(leaf, slot,
	"unaligned key offset for csum item, have %llu should be aligned to %u",
			key->offset, sectorsize);
		return -EUCLEAN;
	}
	if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) {
		generic_err(leaf, slot,
	"unaligned item size for csum item, have %u should be aligned to %u",
			btrfs_item_size_nr(leaf, slot), csumsize);
		return -EUCLEAN;
	}
	return 0;
}

static int check_dir_item(struct extent_buffer *leaf,
			  struct btrfs_key *key, struct btrfs_key *prev_key,
			  int slot)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	struct btrfs_dir_item *di;
	u32 item_size = btrfs_item_size_nr(leaf, slot);
	u32 cur = 0;

	if (!check_prev_ino(leaf, key, slot, prev_key))
		return -EUCLEAN;
	di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
	while (cur < item_size) {
		u32 name_len;
		u32 data_len;
		u32 max_name_len;
		u32 total_size;
		u32 name_hash;
		u8 dir_type;

		/* header itself should not cross item boundary */
		if (cur + sizeof(*di) > item_size) {
			dir_item_err(leaf, slot,
		"dir item header crosses item boundary, have %zu boundary %u",
				cur + sizeof(*di), item_size);
			return -EUCLEAN;
		}

		/* dir type check */
		dir_type = btrfs_dir_type(leaf, di);
		if (dir_type >= BTRFS_FT_MAX) {
			dir_item_err(leaf, slot,
			"invalid dir item type, have %u expect [0, %u)",
				dir_type, BTRFS_FT_MAX);
			return -EUCLEAN;
		}

		if (key->type == BTRFS_XATTR_ITEM_KEY &&
		    dir_type != BTRFS_FT_XATTR) {
			dir_item_err(leaf, slot,
		"invalid dir item type for XATTR key, have %u expect %u",
				dir_type, BTRFS_FT_XATTR);
			return -EUCLEAN;
		}
		if (dir_type == BTRFS_FT_XATTR &&
		    key->type != BTRFS_XATTR_ITEM_KEY) {
			dir_item_err(leaf, slot,
			"xattr dir type found for non-XATTR key");
			return -EUCLEAN;
		}
		if (dir_type == BTRFS_FT_XATTR)
			max_name_len = XATTR_NAME_MAX;
		else
			max_name_len = BTRFS_NAME_LEN;

		/* Name/data length check */
		name_len = btrfs_dir_name_len(leaf, di);
		data_len = btrfs_dir_data_len(leaf, di);
		if (name_len > max_name_len) {
			dir_item_err(leaf, slot,
			"dir item name len too long, have %u max %u",
				name_len, max_name_len);
			return -EUCLEAN;
		}
		if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(fs_info)) {
			dir_item_err(leaf, slot,
			"dir item name and data len too long, have %u max %u",
				name_len + data_len,
				BTRFS_MAX_XATTR_SIZE(fs_info));
			return -EUCLEAN;
		}

		if (data_len && dir_type != BTRFS_FT_XATTR) {
			dir_item_err(leaf, slot,
			"dir item with invalid data len, have %u expect 0",
				data_len);
			return -EUCLEAN;
		}

		total_size = sizeof(*di) + name_len + data_len;

		/* header and name/data should not cross item boundary */
		if (cur + total_size > item_size) {
			dir_item_err(leaf, slot,
		"dir item data crosses item boundary, have %u boundary %u",
				cur + total_size, item_size);
			return -EUCLEAN;
		}

		/*
		 * Special check for XATTR/DIR_ITEM, as key->offset is name
		 * hash, should match its name
		 */
		if (key->type == BTRFS_DIR_ITEM_KEY ||
		    key->type == BTRFS_XATTR_ITEM_KEY) {
			char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)];

			read_extent_buffer(leaf, namebuf,
					(unsigned long)(di + 1), name_len);
			name_hash = btrfs_name_hash(namebuf, name_len);
			if (key->offset != name_hash) {
				dir_item_err(leaf, slot,
		"name hash mismatch with key, have 0x%016x expect 0x%016llx",
					name_hash, key->offset);
				return -EUCLEAN;
			}
		}
		cur += total_size;
		di = (struct btrfs_dir_item *)((void *)di + total_size);
	}
	return 0;
}

__printf(3, 4)
__cold
static void block_group_err(const struct extent_buffer *eb, int slot,
			    const char *fmt, ...)
{
	const struct btrfs_fs_info *fs_info = eb->fs_info;
	struct btrfs_key key;
	struct va_format vaf;
	va_list args;

	btrfs_item_key_to_cpu(eb, &key, slot);
	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(fs_info,
	"corrupt %s: root=%llu block=%llu slot=%d bg_start=%llu bg_len=%llu, %pV",
		btrfs_header_level(eb) == 0 ? "leaf" : "node",
		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
		key.objectid, key.offset, &vaf);
	va_end(args);
}

static int check_block_group_item(struct extent_buffer *leaf,
				  struct btrfs_key *key, int slot)
{
	struct btrfs_block_group_item bgi;
	u32 item_size = btrfs_item_size_nr(leaf, slot);
	u64 flags;
	u64 type;

	/*
	 * Here we don't really care about alignment since extent allocator can
	 * handle it.  We care more about the size.
	 */
	if (key->offset == 0) {
		block_group_err(leaf, slot,
				"invalid block group size 0");
		return -EUCLEAN;
	}

	if (item_size != sizeof(bgi)) {
		block_group_err(leaf, slot,
			"invalid item size, have %u expect %zu",
				item_size, sizeof(bgi));
		return -EUCLEAN;
	}

	read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
			   sizeof(bgi));
	if (btrfs_stack_block_group_chunk_objectid(&bgi) !=
	    BTRFS_FIRST_CHUNK_TREE_OBJECTID) {
		block_group_err(leaf, slot,
		"invalid block group chunk objectid, have %llu expect %llu",
				btrfs_stack_block_group_chunk_objectid(&bgi),
				BTRFS_FIRST_CHUNK_TREE_OBJECTID);
		return -EUCLEAN;
	}

	if (btrfs_stack_block_group_used(&bgi) > key->offset) {
		block_group_err(leaf, slot,
			"invalid block group used, have %llu expect [0, %llu)",
				btrfs_stack_block_group_used(&bgi), key->offset);
		return -EUCLEAN;
	}

	flags = btrfs_stack_block_group_flags(&bgi);
	if (hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1) {
		block_group_err(leaf, slot,
"invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set",
			flags & BTRFS_BLOCK_GROUP_PROFILE_MASK,
			hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK));
		return -EUCLEAN;
	}

	type = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
	if (type != BTRFS_BLOCK_GROUP_DATA &&
	    type != BTRFS_BLOCK_GROUP_METADATA &&
	    type != BTRFS_BLOCK_GROUP_SYSTEM &&
	    type != (BTRFS_BLOCK_GROUP_METADATA |
			   BTRFS_BLOCK_GROUP_DATA)) {
		block_group_err(leaf, slot,
"invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llx or 0x%llx",
			type, hweight64(type),
			BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA,
			BTRFS_BLOCK_GROUP_SYSTEM,
			BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA);
		return -EUCLEAN;
	}
	return 0;
}

__printf(4, 5)
__cold
static void chunk_err(const struct extent_buffer *leaf,
		      const struct btrfs_chunk *chunk, u64 logical,
		      const char *fmt, ...)
{
	const struct btrfs_fs_info *fs_info = leaf->fs_info;
	bool is_sb;
	struct va_format vaf;
	va_list args;
	int i;
	int slot = -1;

	/* Only superblock eb is able to have such small offset */
	is_sb = (leaf->start == BTRFS_SUPER_INFO_OFFSET);

	if (!is_sb) {
		/*
		 * Get the slot number by iterating through all slots, this
		 * would provide better readability.
		 */
		for (i = 0; i < btrfs_header_nritems(leaf); i++) {
			if (btrfs_item_ptr_offset(leaf, i) ==
					(unsigned long)chunk) {
				slot = i;
				break;
			}
		}
	}
	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;

	if (is_sb)
		btrfs_crit(fs_info,
		"corrupt superblock syschunk array: chunk_start=%llu, %pV",
			   logical, &vaf);
	else
		btrfs_crit(fs_info,
	"corrupt leaf: root=%llu block=%llu slot=%d chunk_start=%llu, %pV",
			   BTRFS_CHUNK_TREE_OBJECTID, leaf->start, slot,
			   logical, &vaf);
	va_end(args);
}

/*
 * The common chunk check which could also work on super block sys chunk array.
 *
 * Return -EUCLEAN if anything is corrupted.
 * Return 0 if everything is OK.
 */
int btrfs_check_chunk_valid(struct extent_buffer *leaf,
			    struct btrfs_chunk *chunk, u64 logical)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	u64 length;
	u64 stripe_len;
	u16 num_stripes;
	u16 sub_stripes;
	u64 type;
	u64 features;
	bool mixed = false;

	length = btrfs_chunk_length(leaf, chunk);
	stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
	sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
	type = btrfs_chunk_type(leaf, chunk);

	if (!num_stripes) {
		chunk_err(leaf, chunk, logical,
			  "invalid chunk num_stripes, have %u", num_stripes);
		return -EUCLEAN;
	}
	if (!IS_ALIGNED(logical, fs_info->sectorsize)) {
		chunk_err(leaf, chunk, logical,
		"invalid chunk logical, have %llu should aligned to %u",
			  logical, fs_info->sectorsize);
		return -EUCLEAN;
	}
	if (btrfs_chunk_sector_size(leaf, chunk) != fs_info->sectorsize) {
		chunk_err(leaf, chunk, logical,
			  "invalid chunk sectorsize, have %u expect %u",
			  btrfs_chunk_sector_size(leaf, chunk),
			  fs_info->sectorsize);
		return -EUCLEAN;
	}
	if (!length || !IS_ALIGNED(length, fs_info->sectorsize)) {
		chunk_err(leaf, chunk, logical,
			  "invalid chunk length, have %llu", length);
		return -EUCLEAN;
	}
	if (!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN) {
		chunk_err(leaf, chunk, logical,
			  "invalid chunk stripe length: %llu",
			  stripe_len);
		return -EUCLEAN;
	}
	if (~(BTRFS_BLOCK_GROUP_TYPE_MASK | BTRFS_BLOCK_GROUP_PROFILE_MASK) &
	    type) {
		chunk_err(leaf, chunk, logical,
			  "unrecognized chunk type: 0x%llx",
			  ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
			    BTRFS_BLOCK_GROUP_PROFILE_MASK) &
			  btrfs_chunk_type(leaf, chunk));
		return -EUCLEAN;
	}

	if (!has_single_bit_set(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
	    (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0) {
		chunk_err(leaf, chunk, logical,
		"invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set",
			  type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
		return -EUCLEAN;
	}
	if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) {
		chunk_err(leaf, chunk, logical,
	"missing chunk type flag, have 0x%llx one bit must be set in 0x%llx",
			  type, BTRFS_BLOCK_GROUP_TYPE_MASK);
		return -EUCLEAN;
	}

	if ((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
	    (type & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA))) {
		chunk_err(leaf, chunk, logical,
			  "system chunk with data or metadata type: 0x%llx",
			  type);
		return -EUCLEAN;
	}

	features = btrfs_super_incompat_flags(fs_info->super_copy);
	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
		mixed = true;

	if (!mixed) {
		if ((type & BTRFS_BLOCK_GROUP_METADATA) &&
		    (type & BTRFS_BLOCK_GROUP_DATA)) {
			chunk_err(leaf, chunk, logical,
			"mixed chunk type in non-mixed mode: 0x%llx", type);
			return -EUCLEAN;
		}
	}

	if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
	    (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes != 2) ||
	    (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
	    (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
	    (type & BTRFS_BLOCK_GROUP_DUP && num_stripes != 2) ||
	    ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 && num_stripes != 1)) {
		chunk_err(leaf, chunk, logical,
			"invalid num_stripes:sub_stripes %u:%u for profile %llu",
			num_stripes, sub_stripes,
			type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
		return -EUCLEAN;
	}

	return 0;
}

__printf(3, 4)
__cold
static void dev_item_err(const struct extent_buffer *eb, int slot,
			 const char *fmt, ...)
{
	struct btrfs_key key;
	struct va_format vaf;
	va_list args;

	btrfs_item_key_to_cpu(eb, &key, slot);
	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(eb->fs_info,
	"corrupt %s: root=%llu block=%llu slot=%d devid=%llu %pV",
		btrfs_header_level(eb) == 0 ? "leaf" : "node",
		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
		key.objectid, &vaf);
	va_end(args);
}

static int check_dev_item(struct extent_buffer *leaf,
			  struct btrfs_key *key, int slot)
{
	struct btrfs_dev_item *ditem;

	if (key->objectid != BTRFS_DEV_ITEMS_OBJECTID) {
		dev_item_err(leaf, slot,
			     "invalid objectid: has=%llu expect=%llu",
			     key->objectid, BTRFS_DEV_ITEMS_OBJECTID);
		return -EUCLEAN;
	}
	ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item);
	if (btrfs_device_id(leaf, ditem) != key->offset) {
		dev_item_err(leaf, slot,
			     "devid mismatch: key has=%llu item has=%llu",
			     key->offset, btrfs_device_id(leaf, ditem));
		return -EUCLEAN;
	}

	/*
	 * For device total_bytes, we don't have reliable way to check it, as
	 * it can be 0 for device removal. Device size check can only be done
	 * by dev extents check.
	 */
	if (btrfs_device_bytes_used(leaf, ditem) >
	    btrfs_device_total_bytes(leaf, ditem)) {
		dev_item_err(leaf, slot,
			     "invalid bytes used: have %llu expect [0, %llu]",
			     btrfs_device_bytes_used(leaf, ditem),
			     btrfs_device_total_bytes(leaf, ditem));
		return -EUCLEAN;
	}
	/*
	 * Remaining members like io_align/type/gen/dev_group aren't really
	 * utilized.  Skip them to make later usage of them easier.
	 */
	return 0;
}

/* Inode item error output has the same format as dir_item_err() */
#define inode_item_err(fs_info, eb, slot, fmt, ...)			\
	dir_item_err(eb, slot, fmt, __VA_ARGS__)

static int check_inode_item(struct extent_buffer *leaf,
			    struct btrfs_key *key, int slot)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	struct btrfs_inode_item *iitem;
	u64 super_gen = btrfs_super_generation(fs_info->super_copy);
	u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
	u32 mode;

	if ((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
	     key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
	    key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
	    key->objectid != BTRFS_FREE_INO_OBJECTID) {
		generic_err(leaf, slot,
	"invalid key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
			    key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
			    BTRFS_FIRST_FREE_OBJECTID,
			    BTRFS_LAST_FREE_OBJECTID,
			    BTRFS_FREE_INO_OBJECTID);
		return -EUCLEAN;
	}
	if (key->offset != 0) {
		inode_item_err(fs_info, leaf, slot,
			"invalid key offset: has %llu expect 0",
			key->offset);
		return -EUCLEAN;
	}
	iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);

	/* Here we use super block generation + 1 to handle log tree */
	if (btrfs_inode_generation(leaf, iitem) > super_gen + 1) {
		inode_item_err(fs_info, leaf, slot,
			"invalid inode generation: has %llu expect (0, %llu]",
			       btrfs_inode_generation(leaf, iitem),
			       super_gen + 1);
		return -EUCLEAN;
	}
	/* Note for ROOT_TREE_DIR_ITEM, mkfs could set its transid 0 */
	if (btrfs_inode_transid(leaf, iitem) > super_gen + 1) {
		inode_item_err(fs_info, leaf, slot,
			"invalid inode generation: has %llu expect [0, %llu]",
			       btrfs_inode_transid(leaf, iitem), super_gen + 1);
		return -EUCLEAN;
	}

	/*
	 * For size and nbytes it's better not to be too strict, as for dir
	 * item its size/nbytes can easily get wrong, but doesn't affect
	 * anything in the fs. So here we skip the check.
	 */
	mode = btrfs_inode_mode(leaf, iitem);
	if (mode & ~valid_mask) {
		inode_item_err(fs_info, leaf, slot,
			       "unknown mode bit detected: 0x%x",
			       mode & ~valid_mask);
		return -EUCLEAN;
	}

	/*
	 * S_IFMT is not bit mapped so we can't completely rely on
	 * is_power_of_2/has_single_bit_set, but it can save us from checking
	 * FIFO/CHR/DIR/REG.  Only needs to check BLK, LNK and SOCKS
	 */
	if (!has_single_bit_set(mode & S_IFMT)) {
		if (!S_ISLNK(mode) && !S_ISBLK(mode) && !S_ISSOCK(mode)) {
			inode_item_err(fs_info, leaf, slot,
			"invalid mode: has 0%o expect valid S_IF* bit(s)",
				       mode & S_IFMT);
			return -EUCLEAN;
		}
	}
	if (S_ISDIR(mode) && btrfs_inode_nlink(leaf, iitem) > 1) {
		inode_item_err(fs_info, leaf, slot,
		       "invalid nlink: has %u expect no more than 1 for dir",
			btrfs_inode_nlink(leaf, iitem));
		return -EUCLEAN;
	}
	if (btrfs_inode_flags(leaf, iitem) & ~BTRFS_INODE_FLAG_MASK) {
		inode_item_err(fs_info, leaf, slot,
			       "unknown flags detected: 0x%llx",
			       btrfs_inode_flags(leaf, iitem) &
			       ~BTRFS_INODE_FLAG_MASK);
		return -EUCLEAN;
	}
	return 0;
}

static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
			   int slot)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	struct btrfs_root_item ri;
	const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY |
				     BTRFS_ROOT_SUBVOL_DEAD;

	/* No such tree id */
	if (key->objectid == 0) {
		generic_err(leaf, slot, "invalid root id 0");
		return -EUCLEAN;
	}

	/*
	 * Some older kernel may create ROOT_ITEM with non-zero offset, so here
	 * we only check offset for reloc tree whose key->offset must be a
	 * valid tree.
	 */
	if (key->objectid == BTRFS_TREE_RELOC_OBJECTID && key->offset == 0) {
		generic_err(leaf, slot, "invalid root id 0 for reloc tree");
		return -EUCLEAN;
	}

	if (btrfs_item_size_nr(leaf, slot) != sizeof(ri)) {
		generic_err(leaf, slot,
			    "invalid root item size, have %u expect %zu",
			    btrfs_item_size_nr(leaf, slot), sizeof(ri));
	}

	read_extent_buffer(leaf, &ri, btrfs_item_ptr_offset(leaf, slot),
			   sizeof(ri));

	/* Generation related */
	if (btrfs_root_generation(&ri) >
	    btrfs_super_generation(fs_info->super_copy) + 1) {
		generic_err(leaf, slot,
			"invalid root generation, have %llu expect (0, %llu]",
			    btrfs_root_generation(&ri),
			    btrfs_super_generation(fs_info->super_copy) + 1);
		return -EUCLEAN;
	}
	if (btrfs_root_generation_v2(&ri) >
	    btrfs_super_generation(fs_info->super_copy) + 1) {
		generic_err(leaf, slot,
		"invalid root v2 generation, have %llu expect (0, %llu]",
			    btrfs_root_generation_v2(&ri),
			    btrfs_super_generation(fs_info->super_copy) + 1);
		return -EUCLEAN;
	}
	if (btrfs_root_last_snapshot(&ri) >
	    btrfs_super_generation(fs_info->super_copy) + 1) {
		generic_err(leaf, slot,
		"invalid root last_snapshot, have %llu expect (0, %llu]",
			    btrfs_root_last_snapshot(&ri),
			    btrfs_super_generation(fs_info->super_copy) + 1);
		return -EUCLEAN;
	}

	/* Alignment and level check */
	if (!IS_ALIGNED(btrfs_root_bytenr(&ri), fs_info->sectorsize)) {
		generic_err(leaf, slot,
		"invalid root bytenr, have %llu expect to be aligned to %u",
			    btrfs_root_bytenr(&ri), fs_info->sectorsize);
		return -EUCLEAN;
	}
	if (btrfs_root_level(&ri) >= BTRFS_MAX_LEVEL) {
		generic_err(leaf, slot,
			    "invalid root level, have %u expect [0, %u]",
			    btrfs_root_level(&ri), BTRFS_MAX_LEVEL - 1);
		return -EUCLEAN;
	}
	if (ri.drop_level >= BTRFS_MAX_LEVEL) {
		generic_err(leaf, slot,
			    "invalid root level, have %u expect [0, %u]",
			    ri.drop_level, BTRFS_MAX_LEVEL - 1);
		return -EUCLEAN;
	}

	/* Flags check */
	if (btrfs_root_flags(&ri) & ~valid_root_flags) {
		generic_err(leaf, slot,
			    "invalid root flags, have 0x%llx expect mask 0x%llx",
			    btrfs_root_flags(&ri), valid_root_flags);
		return -EUCLEAN;
	}
	return 0;
}

__printf(3,4)
__cold
static void extent_err(const struct extent_buffer *eb, int slot,
		       const char *fmt, ...)
{
	struct btrfs_key key;
	struct va_format vaf;
	va_list args;
	u64 bytenr;
	u64 len;

	btrfs_item_key_to_cpu(eb, &key, slot);
	bytenr = key.objectid;
	if (key.type == BTRFS_METADATA_ITEM_KEY ||
	    key.type == BTRFS_TREE_BLOCK_REF_KEY ||
	    key.type == BTRFS_SHARED_BLOCK_REF_KEY)
		len = eb->fs_info->nodesize;
	else
		len = key.offset;
	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	btrfs_crit(eb->fs_info,
	"corrupt %s: block=%llu slot=%d extent bytenr=%llu len=%llu %pV",
		btrfs_header_level(eb) == 0 ? "leaf" : "node",
		eb->start, slot, bytenr, len, &vaf);
	va_end(args);
}

static int check_extent_item(struct extent_buffer *leaf,
			     struct btrfs_key *key, int slot)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	struct btrfs_extent_item *ei;
	bool is_tree_block = false;
	unsigned long ptr;	/* Current pointer inside inline refs */
	unsigned long end;	/* Extent item end */
	const u32 item_size = btrfs_item_size_nr(leaf, slot);
	u64 flags;
	u64 generation;
	u64 total_refs;		/* Total refs in btrfs_extent_item */
	u64 inline_refs = 0;	/* found total inline refs */

	if (key->type == BTRFS_METADATA_ITEM_KEY &&
	    !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
		generic_err(leaf, slot,
"invalid key type, METADATA_ITEM type invalid when SKINNY_METADATA feature disabled");
		return -EUCLEAN;
	}
	/* key->objectid is the bytenr for both key types */
	if (!IS_ALIGNED(key->objectid, fs_info->sectorsize)) {
		generic_err(leaf, slot,
		"invalid key objectid, have %llu expect to be aligned to %u",
			   key->objectid, fs_info->sectorsize);
		return -EUCLEAN;
	}

	/* key->offset is tree level for METADATA_ITEM_KEY */
	if (key->type == BTRFS_METADATA_ITEM_KEY &&
	    key->offset >= BTRFS_MAX_LEVEL) {
		extent_err(leaf, slot,
			   "invalid tree level, have %llu expect [0, %u]",
			   key->offset, BTRFS_MAX_LEVEL - 1);
		return -EUCLEAN;
	}

	/*
	 * EXTENT/METADATA_ITEM consists of:
	 * 1) One btrfs_extent_item
	 *    Records the total refs, type and generation of the extent.
	 *
	 * 2) One btrfs_tree_block_info (for EXTENT_ITEM and tree backref only)
	 *    Records the first key and level of the tree block.
	 *
	 * 2) Zero or more btrfs_extent_inline_ref(s)
	 *    Each inline ref has one btrfs_extent_inline_ref shows:
	 *    2.1) The ref type, one of the 4
	 *         TREE_BLOCK_REF	Tree block only
	 *         SHARED_BLOCK_REF	Tree block only
	 *         EXTENT_DATA_REF	Data only
	 *         SHARED_DATA_REF	Data only
	 *    2.2) Ref type specific data
	 *         Either using btrfs_extent_inline_ref::offset, or specific
	 *         data structure.
	 */
	if (item_size < sizeof(*ei)) {
		extent_err(leaf, slot,
			   "invalid item size, have %u expect [%zu, %u)",
			   item_size, sizeof(*ei),
			   BTRFS_LEAF_DATA_SIZE(fs_info));
		return -EUCLEAN;
	}
	end = item_size + btrfs_item_ptr_offset(leaf, slot);

	/* Checks against extent_item */
	ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
	flags = btrfs_extent_flags(leaf, ei);
	total_refs = btrfs_extent_refs(leaf, ei);
	generation = btrfs_extent_generation(leaf, ei);
	if (generation > btrfs_super_generation(fs_info->super_copy) + 1) {
		extent_err(leaf, slot,
			   "invalid generation, have %llu expect (0, %llu]",
			   generation,
			   btrfs_super_generation(fs_info->super_copy) + 1);
		return -EUCLEAN;
	}
	if (!has_single_bit_set(flags & (BTRFS_EXTENT_FLAG_DATA |
					 BTRFS_EXTENT_FLAG_TREE_BLOCK))) {
		extent_err(leaf, slot,
		"invalid extent flag, have 0x%llx expect 1 bit set in 0x%llx",
			flags, BTRFS_EXTENT_FLAG_DATA |
			BTRFS_EXTENT_FLAG_TREE_BLOCK);
		return -EUCLEAN;
	}
	is_tree_block = !!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK);
	if (is_tree_block) {
		if (key->type == BTRFS_EXTENT_ITEM_KEY &&
		    key->offset != fs_info->nodesize) {
			extent_err(leaf, slot,
				   "invalid extent length, have %llu expect %u",
				   key->offset, fs_info->nodesize);
			return -EUCLEAN;
		}
	} else {
		if (key->type != BTRFS_EXTENT_ITEM_KEY) {
			extent_err(leaf, slot,
			"invalid key type, have %u expect %u for data backref",
				   key->type, BTRFS_EXTENT_ITEM_KEY);
			return -EUCLEAN;
		}
		if (!IS_ALIGNED(key->offset, fs_info->sectorsize)) {
			extent_err(leaf, slot,
			"invalid extent length, have %llu expect aligned to %u",
				   key->offset, fs_info->sectorsize);
			return -EUCLEAN;
		}
	}
	ptr = (unsigned long)(struct btrfs_extent_item *)(ei + 1);

	/* Check the special case of btrfs_tree_block_info */
	if (is_tree_block && key->type != BTRFS_METADATA_ITEM_KEY) {
		struct btrfs_tree_block_info *info;

		info = (struct btrfs_tree_block_info *)ptr;
		if (btrfs_tree_block_level(leaf, info) >= BTRFS_MAX_LEVEL) {
			extent_err(leaf, slot,
			"invalid tree block info level, have %u expect [0, %u]",
				   btrfs_tree_block_level(leaf, info),
				   BTRFS_MAX_LEVEL - 1);
			return -EUCLEAN;
		}
		ptr = (unsigned long)(struct btrfs_tree_block_info *)(info + 1);
	}

	/* Check inline refs */
	while (ptr < end) {
		struct btrfs_extent_inline_ref *iref;
		struct btrfs_extent_data_ref *dref;
		struct btrfs_shared_data_ref *sref;
		u64 dref_offset;
		u64 inline_offset;
		u8 inline_type;

		if (ptr + sizeof(*iref) > end) {
			extent_err(leaf, slot,
"inline ref item overflows extent item, ptr %lu iref size %zu end %lu",
				   ptr, sizeof(*iref), end);
			return -EUCLEAN;
		}
		iref = (struct btrfs_extent_inline_ref *)ptr;
		inline_type = btrfs_extent_inline_ref_type(leaf, iref);
		inline_offset = btrfs_extent_inline_ref_offset(leaf, iref);
		if (ptr + btrfs_extent_inline_ref_size(inline_type) > end) {
			extent_err(leaf, slot,
"inline ref item overflows extent item, ptr %lu iref size %u end %lu",
				   ptr, inline_type, end);
			return -EUCLEAN;
		}

		switch (inline_type) {
		/* inline_offset is subvolid of the owner, no need to check */
		case BTRFS_TREE_BLOCK_REF_KEY:
			inline_refs++;
			break;
		/* Contains parent bytenr */
		case BTRFS_SHARED_BLOCK_REF_KEY:
			if (!IS_ALIGNED(inline_offset, fs_info->sectorsize)) {
				extent_err(leaf, slot,
		"invalid tree parent bytenr, have %llu expect aligned to %u",
					   inline_offset, fs_info->sectorsize);
				return -EUCLEAN;
			}
			inline_refs++;
			break;
		/*
		 * Contains owner subvolid, owner key objectid, adjusted offset.
		 * The only obvious corruption can happen in that offset.
		 */
		case BTRFS_EXTENT_DATA_REF_KEY:
			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
			dref_offset = btrfs_extent_data_ref_offset(leaf, dref);
			if (!IS_ALIGNED(dref_offset, fs_info->sectorsize)) {
				extent_err(leaf, slot,
		"invalid data ref offset, have %llu expect aligned to %u",
					   dref_offset, fs_info->sectorsize);
				return -EUCLEAN;
			}
			inline_refs += btrfs_extent_data_ref_count(leaf, dref);
			break;
		/* Contains parent bytenr and ref count */
		case BTRFS_SHARED_DATA_REF_KEY:
			sref = (struct btrfs_shared_data_ref *)(iref + 1);
			if (!IS_ALIGNED(inline_offset, fs_info->sectorsize)) {
				extent_err(leaf, slot,
		"invalid data parent bytenr, have %llu expect aligned to %u",
					   inline_offset, fs_info->sectorsize);
				return -EUCLEAN;
			}
			inline_refs += btrfs_shared_data_ref_count(leaf, sref);
			break;
		default:
			extent_err(leaf, slot, "unknown inline ref type: %u",
				   inline_type);
			return -EUCLEAN;
		}
		ptr += btrfs_extent_inline_ref_size(inline_type);
	}
	/* No padding is allowed */
	if (ptr != end) {
		extent_err(leaf, slot,
			   "invalid extent item size, padding bytes found");
		return -EUCLEAN;
	}

	/* Finally, check the inline refs against total refs */
	if (inline_refs > total_refs) {
		extent_err(leaf, slot,
			"invalid extent refs, have %llu expect >= inline %llu",
			   total_refs, inline_refs);
		return -EUCLEAN;
	}
	return 0;
}

static int check_simple_keyed_refs(struct extent_buffer *leaf,
				   struct btrfs_key *key, int slot)
{
	u32 expect_item_size = 0;

	if (key->type == BTRFS_SHARED_DATA_REF_KEY)
		expect_item_size = sizeof(struct btrfs_shared_data_ref);

	if (btrfs_item_size_nr(leaf, slot) != expect_item_size) {
		generic_err(leaf, slot,
		"invalid item size, have %u expect %u for key type %u",
			    btrfs_item_size_nr(leaf, slot),
			    expect_item_size, key->type);
		return -EUCLEAN;
	}
	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
		generic_err(leaf, slot,
"invalid key objectid for shared block ref, have %llu expect aligned to %u",
			    key->objectid, leaf->fs_info->sectorsize);
		return -EUCLEAN;
	}
	if (key->type != BTRFS_TREE_BLOCK_REF_KEY &&
	    !IS_ALIGNED(key->offset, leaf->fs_info->sectorsize)) {
		extent_err(leaf, slot,
		"invalid tree parent bytenr, have %llu expect aligned to %u",
			   key->offset, leaf->fs_info->sectorsize);
		return -EUCLEAN;
	}
	return 0;
}

static int check_extent_data_ref(struct extent_buffer *leaf,
				 struct btrfs_key *key, int slot)
{
	struct btrfs_extent_data_ref *dref;
	unsigned long ptr = btrfs_item_ptr_offset(leaf, slot);
	const unsigned long end = ptr + btrfs_item_size_nr(leaf, slot);

	if (btrfs_item_size_nr(leaf, slot) % sizeof(*dref) != 0) {
		generic_err(leaf, slot,
	"invalid item size, have %u expect aligned to %zu for key type %u",
			    btrfs_item_size_nr(leaf, slot),
			    sizeof(*dref), key->type);
	}
	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
		generic_err(leaf, slot,
"invalid key objectid for shared block ref, have %llu expect aligned to %u",
			    key->objectid, leaf->fs_info->sectorsize);
		return -EUCLEAN;
	}
	for (; ptr < end; ptr += sizeof(*dref)) {
		u64 root_objectid;
		u64 owner;
		u64 offset;
		u64 hash;

		dref = (struct btrfs_extent_data_ref *)ptr;
		root_objectid = btrfs_extent_data_ref_root(leaf, dref);
		owner = btrfs_extent_data_ref_objectid(leaf, dref);
		offset = btrfs_extent_data_ref_offset(leaf, dref);
		hash = hash_extent_data_ref(root_objectid, owner, offset);
		if (hash != key->offset) {
			extent_err(leaf, slot,
	"invalid extent data ref hash, item has 0x%016llx key has 0x%016llx",
				   hash, key->offset);
			return -EUCLEAN;
		}
		if (!IS_ALIGNED(offset, leaf->fs_info->sectorsize)) {
			extent_err(leaf, slot,
	"invalid extent data backref offset, have %llu expect aligned to %u",
				   offset, leaf->fs_info->sectorsize);
		}
	}
	return 0;
}

#define inode_ref_err(fs_info, eb, slot, fmt, args...)			\
	inode_item_err(fs_info, eb, slot, fmt, ##args)
static int check_inode_ref(struct extent_buffer *leaf,
			   struct btrfs_key *key, struct btrfs_key *prev_key,
			   int slot)
{
	struct btrfs_inode_ref *iref;
	unsigned long ptr;
	unsigned long end;

	if (!check_prev_ino(leaf, key, slot, prev_key))
		return -EUCLEAN;
	/* namelen can't be 0, so item_size == sizeof() is also invalid */
	if (btrfs_item_size_nr(leaf, slot) <= sizeof(*iref)) {
		inode_ref_err(fs_info, leaf, slot,
			"invalid item size, have %u expect (%zu, %u)",
			btrfs_item_size_nr(leaf, slot),
			sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
		return -EUCLEAN;
	}

	ptr = btrfs_item_ptr_offset(leaf, slot);
	end = ptr + btrfs_item_size_nr(leaf, slot);
	while (ptr < end) {
		u16 namelen;

		if (ptr + sizeof(iref) > end) {
			inode_ref_err(fs_info, leaf, slot,
			"inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
				ptr, end, sizeof(iref));
			return -EUCLEAN;
		}

		iref = (struct btrfs_inode_ref *)ptr;
		namelen = btrfs_inode_ref_name_len(leaf, iref);
		if (ptr + sizeof(*iref) + namelen > end) {
			inode_ref_err(fs_info, leaf, slot,
				"inode ref overflow, ptr %lu end %lu namelen %u",
				ptr, end, namelen);
			return -EUCLEAN;
		}

		/*
		 * NOTE: In theory we should record all found index numbers
		 * to find any duplicated indexes, but that will be too time
		 * consuming for inodes with too many hard links.
		 */
		ptr += sizeof(*iref) + namelen;
	}
	return 0;
}

/*
 * Common point to switch the item-specific validation.
 */
static int check_leaf_item(struct extent_buffer *leaf,
			   struct btrfs_key *key, int slot,
			   struct btrfs_key *prev_key)
{
	int ret = 0;
	struct btrfs_chunk *chunk;

	switch (key->type) {
	case BTRFS_EXTENT_DATA_KEY:
		ret = check_extent_data_item(leaf, key, slot, prev_key);
		break;
	case BTRFS_EXTENT_CSUM_KEY:
		ret = check_csum_item(leaf, key, slot);
		break;
	case BTRFS_DIR_ITEM_KEY:
	case BTRFS_DIR_INDEX_KEY:
	case BTRFS_XATTR_ITEM_KEY:
		ret = check_dir_item(leaf, key, prev_key, slot);
		break;
	case BTRFS_INODE_REF_KEY:
		ret = check_inode_ref(leaf, key, prev_key, slot);
		break;
	case BTRFS_BLOCK_GROUP_ITEM_KEY:
		ret = check_block_group_item(leaf, key, slot);
		break;
	case BTRFS_CHUNK_ITEM_KEY:
		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
		ret = btrfs_check_chunk_valid(leaf, chunk, key->offset);
		break;
	case BTRFS_DEV_ITEM_KEY:
		ret = check_dev_item(leaf, key, slot);
		break;
	case BTRFS_INODE_ITEM_KEY:
		ret = check_inode_item(leaf, key, slot);
		break;
	case BTRFS_ROOT_ITEM_KEY:
		ret = check_root_item(leaf, key, slot);
		break;
	case BTRFS_EXTENT_ITEM_KEY:
	case BTRFS_METADATA_ITEM_KEY:
		ret = check_extent_item(leaf, key, slot);
		break;
	case BTRFS_TREE_BLOCK_REF_KEY:
	case BTRFS_SHARED_DATA_REF_KEY:
	case BTRFS_SHARED_BLOCK_REF_KEY:
		ret = check_simple_keyed_refs(leaf, key, slot);
		break;
	case BTRFS_EXTENT_DATA_REF_KEY:
		ret = check_extent_data_ref(leaf, key, slot);
		break;
	}
	return ret;
}

static int check_leaf(struct extent_buffer *leaf, bool check_item_data)
{
	struct btrfs_fs_info *fs_info = leaf->fs_info;
	/* No valid key type is 0, so all key should be larger than this key */
	struct btrfs_key prev_key = {0, 0, 0};
	struct btrfs_key key;
	u32 nritems = btrfs_header_nritems(leaf);
	int slot;

	if (btrfs_header_level(leaf) != 0) {
		generic_err(leaf, 0,
			"invalid level for leaf, have %d expect 0",
			btrfs_header_level(leaf));
		return -EUCLEAN;
	}

	/*
	 * Extent buffers from a relocation tree have a owner field that
	 * corresponds to the subvolume tree they are based on. So just from an
	 * extent buffer alone we can not find out what is the id of the
	 * corresponding subvolume tree, so we can not figure out if the extent
	 * buffer corresponds to the root of the relocation tree or not. So
	 * skip this check for relocation trees.
	 */
	if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
		u64 owner = btrfs_header_owner(leaf);

		/* These trees must never be empty */
		if (owner == BTRFS_ROOT_TREE_OBJECTID ||
		    owner == BTRFS_CHUNK_TREE_OBJECTID ||
		    owner == BTRFS_EXTENT_TREE_OBJECTID ||
		    owner == BTRFS_DEV_TREE_OBJECTID ||
		    owner == BTRFS_FS_TREE_OBJECTID ||
		    owner == BTRFS_DATA_RELOC_TREE_OBJECTID) {
			generic_err(leaf, 0,
			"invalid root, root %llu must never be empty",
				    owner);
			return -EUCLEAN;
		}
		/* Unknown tree */
		if (owner == 0) {
			generic_err(leaf, 0,
				"invalid owner, root 0 is not defined");
			return -EUCLEAN;
		}
		return 0;
	}

	if (nritems == 0)
		return 0;

	/*
	 * Check the following things to make sure this is a good leaf, and
	 * leaf users won't need to bother with similar sanity checks:
	 *
	 * 1) key ordering
	 * 2) item offset and size
	 *    No overlap, no hole, all inside the leaf.
	 * 3) item content
	 *    If possible, do comprehensive sanity check.
	 *    NOTE: All checks must only rely on the item data itself.
	 */
	for (slot = 0; slot < nritems; slot++) {
		u32 item_end_expected;
		int ret;

		btrfs_item_key_to_cpu(leaf, &key, slot);

		/* Make sure the keys are in the right order */
		if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) {
			generic_err(leaf, slot,
	"bad key order, prev (%llu %u %llu) current (%llu %u %llu)",
				prev_key.objectid, prev_key.type,
				prev_key.offset, key.objectid, key.type,
				key.offset);
			return -EUCLEAN;
		}

		/*
		 * Make sure the offset and ends are right, remember that the
		 * item data starts at the end of the leaf and grows towards the
		 * front.
		 */
		if (slot == 0)
			item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info);
		else
			item_end_expected = btrfs_item_offset_nr(leaf,
								 slot - 1);
		if (btrfs_item_end_nr(leaf, slot) != item_end_expected) {
			generic_err(leaf, slot,
				"unexpected item end, have %u expect %u",
				btrfs_item_end_nr(leaf, slot),
				item_end_expected);
			return -EUCLEAN;
		}

		/*
		 * Check to make sure that we don't point outside of the leaf,
		 * just in case all the items are consistent to each other, but
		 * all point outside of the leaf.
		 */
		if (btrfs_item_end_nr(leaf, slot) >
		    BTRFS_LEAF_DATA_SIZE(fs_info)) {
			generic_err(leaf, slot,
			"slot end outside of leaf, have %u expect range [0, %u]",
				btrfs_item_end_nr(leaf, slot),
				BTRFS_LEAF_DATA_SIZE(fs_info));
			return -EUCLEAN;
		}

		/* Also check if the item pointer overlaps with btrfs item. */
		if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) >
		    btrfs_item_ptr_offset(leaf, slot)) {
			generic_err(leaf, slot,
		"slot overlaps with its data, item end %lu data start %lu",
				btrfs_item_nr_offset(slot) +
				sizeof(struct btrfs_item),
				btrfs_item_ptr_offset(leaf, slot));
			return -EUCLEAN;
		}

		if (check_item_data) {
			/*
			 * Check if the item size and content meet other
			 * criteria
			 */
			ret = check_leaf_item(leaf, &key, slot, &prev_key);
			if (ret < 0)
				return ret;
		}

		prev_key.objectid = key.objectid;
		prev_key.type = key.type;
		prev_key.offset = key.offset;
	}

	return 0;
}

int btrfs_check_leaf_full(struct extent_buffer *leaf)
{
	return check_leaf(leaf, true);
}
ALLOW_ERROR_INJECTION(btrfs_check_leaf_full, ERRNO);

int btrfs_check_leaf_relaxed(struct extent_buffer *leaf)
{
	return check_leaf(leaf, false);
}

int btrfs_check_node(struct extent_buffer *node)
{
	struct btrfs_fs_info *fs_info = node->fs_info;
	unsigned long nr = btrfs_header_nritems(node);
	struct btrfs_key key, next_key;
	int slot;
	int level = btrfs_header_level(node);
	u64 bytenr;
	int ret = 0;

	if (level <= 0 || level >= BTRFS_MAX_LEVEL) {
		generic_err(node, 0,
			"invalid level for node, have %d expect [1, %d]",
			level, BTRFS_MAX_LEVEL - 1);
		return -EUCLEAN;
	}
	if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info)) {
		btrfs_crit(fs_info,
"corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
			   btrfs_header_owner(node), node->start,
			   nr == 0 ? "small" : "large", nr,
			   BTRFS_NODEPTRS_PER_BLOCK(fs_info));
		return -EUCLEAN;
	}

	for (slot = 0; slot < nr - 1; slot++) {
		bytenr = btrfs_node_blockptr(node, slot);
		btrfs_node_key_to_cpu(node, &key, slot);
		btrfs_node_key_to_cpu(node, &next_key, slot + 1);

		if (!bytenr) {
			generic_err(node, slot,
				"invalid NULL node pointer");
			ret = -EUCLEAN;
			goto out;
		}
		if (!IS_ALIGNED(bytenr, fs_info->sectorsize)) {
			generic_err(node, slot,
			"unaligned pointer, have %llu should be aligned to %u",
				bytenr, fs_info->sectorsize);
			ret = -EUCLEAN;
			goto out;
		}

		if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
			generic_err(node, slot,
	"bad key order, current (%llu %u %llu) next (%llu %u %llu)",
				key.objectid, key.type, key.offset,
				next_key.objectid, next_key.type,
				next_key.offset);
			ret = -EUCLEAN;
			goto out;
		}
	}
out:
	return ret;
}
ALLOW_ERROR_INJECTION(btrfs_check_node, ERRNO);