summaryrefslogtreecommitdiffstats
path: root/fs/ntfs3/index.c
blob: 440328147e7e39f011a0ee7b11bbfaf7f93b4d45 (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
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
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
// SPDX-License-Identifier: GPL-2.0
/*
 *
 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
 *
 */

#include <linux/blkdev.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/kernel.h>

#include "debug.h"
#include "ntfs.h"
#include "ntfs_fs.h"

static const struct INDEX_NAMES {
	const __le16 *name;
	u8 name_len;
} s_index_names[INDEX_MUTEX_TOTAL] = {
	{ I30_NAME, ARRAY_SIZE(I30_NAME) }, { SII_NAME, ARRAY_SIZE(SII_NAME) },
	{ SDH_NAME, ARRAY_SIZE(SDH_NAME) }, { SO_NAME, ARRAY_SIZE(SO_NAME) },
	{ SQ_NAME, ARRAY_SIZE(SQ_NAME) },   { SR_NAME, ARRAY_SIZE(SR_NAME) },
};

/*
 * cmp_fnames - Compare two names in index.
 *
 * if l1 != 0
 *   Both names are little endian on-disk ATTR_FILE_NAME structs.
 * else
 *   key1 - cpu_str, key2 - ATTR_FILE_NAME
 */
static int cmp_fnames(const void *key1, size_t l1, const void *key2, size_t l2,
		      const void *data)
{
	const struct ATTR_FILE_NAME *f2 = key2;
	const struct ntfs_sb_info *sbi = data;
	const struct ATTR_FILE_NAME *f1;
	u16 fsize2;
	bool both_case;

	if (l2 <= offsetof(struct ATTR_FILE_NAME, name))
		return -1;

	fsize2 = fname_full_size(f2);
	if (l2 < fsize2)
		return -1;

	both_case = f2->type != FILE_NAME_DOS /*&& !sbi->options.nocase*/;
	if (!l1) {
		const struct le_str *s2 = (struct le_str *)&f2->name_len;

		/*
		 * If names are equal (case insensitive)
		 * try to compare it case sensitive.
		 */
		return ntfs_cmp_names_cpu(key1, s2, sbi->upcase, both_case);
	}

	f1 = key1;
	return ntfs_cmp_names(f1->name, f1->name_len, f2->name, f2->name_len,
			      sbi->upcase, both_case);
}

/*
 * cmp_uint - $SII of $Secure and $Q of Quota
 */
static int cmp_uint(const void *key1, size_t l1, const void *key2, size_t l2,
		    const void *data)
{
	const u32 *k1 = key1;
	const u32 *k2 = key2;

	if (l2 < sizeof(u32))
		return -1;

	if (*k1 < *k2)
		return -1;
	if (*k1 > *k2)
		return 1;
	return 0;
}

/*
 * cmp_sdh - $SDH of $Secure
 */
static int cmp_sdh(const void *key1, size_t l1, const void *key2, size_t l2,
		   const void *data)
{
	const struct SECURITY_KEY *k1 = key1;
	const struct SECURITY_KEY *k2 = key2;
	u32 t1, t2;

	if (l2 < sizeof(struct SECURITY_KEY))
		return -1;

	t1 = le32_to_cpu(k1->hash);
	t2 = le32_to_cpu(k2->hash);

	/* First value is a hash value itself. */
	if (t1 < t2)
		return -1;
	if (t1 > t2)
		return 1;

	/* Second value is security Id. */
	if (data) {
		t1 = le32_to_cpu(k1->sec_id);
		t2 = le32_to_cpu(k2->sec_id);
		if (t1 < t2)
			return -1;
		if (t1 > t2)
			return 1;
	}

	return 0;
}

/*
 * cmp_uints - $O of ObjId and "$R" for Reparse.
 */
static int cmp_uints(const void *key1, size_t l1, const void *key2, size_t l2,
		     const void *data)
{
	const __le32 *k1 = key1;
	const __le32 *k2 = key2;
	size_t count;

	if ((size_t)data == 1) {
		/*
		 * ni_delete_all -> ntfs_remove_reparse ->
		 * delete all with this reference.
		 * k1, k2 - pointers to REPARSE_KEY
		 */

		k1 += 1; // Skip REPARSE_KEY.ReparseTag
		k2 += 1; // Skip REPARSE_KEY.ReparseTag
		if (l2 <= sizeof(int))
			return -1;
		l2 -= sizeof(int);
		if (l1 <= sizeof(int))
			return 1;
		l1 -= sizeof(int);
	}

	if (l2 < sizeof(int))
		return -1;

	for (count = min(l1, l2) >> 2; count > 0; --count, ++k1, ++k2) {
		u32 t1 = le32_to_cpu(*k1);
		u32 t2 = le32_to_cpu(*k2);

		if (t1 > t2)
			return 1;
		if (t1 < t2)
			return -1;
	}

	if (l1 > l2)
		return 1;
	if (l1 < l2)
		return -1;

	return 0;
}

static inline NTFS_CMP_FUNC get_cmp_func(const struct INDEX_ROOT *root)
{
	switch (root->type) {
	case ATTR_NAME:
		if (root->rule == NTFS_COLLATION_TYPE_FILENAME)
			return &cmp_fnames;
		break;
	case ATTR_ZERO:
		switch (root->rule) {
		case NTFS_COLLATION_TYPE_UINT:
			return &cmp_uint;
		case NTFS_COLLATION_TYPE_SECURITY_HASH:
			return &cmp_sdh;
		case NTFS_COLLATION_TYPE_UINTS:
			return &cmp_uints;
		default:
			break;
		}
		break;
	default:
		break;
	}

	return NULL;
}

struct bmp_buf {
	struct ATTRIB *b;
	struct mft_inode *mi;
	struct buffer_head *bh;
	ulong *buf;
	size_t bit;
	u32 nbits;
	u64 new_valid;
};

static int bmp_buf_get(struct ntfs_index *indx, struct ntfs_inode *ni,
		       size_t bit, struct bmp_buf *bbuf)
{
	struct ATTRIB *b;
	size_t data_size, valid_size, vbo, off = bit >> 3;
	struct ntfs_sb_info *sbi = ni->mi.sbi;
	CLST vcn = off >> sbi->cluster_bits;
	struct ATTR_LIST_ENTRY *le = NULL;
	struct buffer_head *bh;
	struct super_block *sb;
	u32 blocksize;
	const struct INDEX_NAMES *in = &s_index_names[indx->type];

	bbuf->bh = NULL;

	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
			 &vcn, &bbuf->mi);
	bbuf->b = b;
	if (!b)
		return -EINVAL;

	if (!b->non_res) {
		data_size = le32_to_cpu(b->res.data_size);

		if (off >= data_size)
			return -EINVAL;

		bbuf->buf = (ulong *)resident_data(b);
		bbuf->bit = 0;
		bbuf->nbits = data_size * 8;

		return 0;
	}

	data_size = le64_to_cpu(b->nres.data_size);
	if (WARN_ON(off >= data_size)) {
		/* Looks like filesystem error. */
		return -EINVAL;
	}

	valid_size = le64_to_cpu(b->nres.valid_size);

	bh = ntfs_bread_run(sbi, &indx->bitmap_run, off);
	if (!bh)
		return -EIO;

	if (IS_ERR(bh))
		return PTR_ERR(bh);

	bbuf->bh = bh;

	if (buffer_locked(bh))
		__wait_on_buffer(bh);

	lock_buffer(bh);

	sb = sbi->sb;
	blocksize = sb->s_blocksize;

	vbo = off & ~(size_t)sbi->block_mask;

	bbuf->new_valid = vbo + blocksize;
	if (bbuf->new_valid <= valid_size)
		bbuf->new_valid = 0;
	else if (bbuf->new_valid > data_size)
		bbuf->new_valid = data_size;

	if (vbo >= valid_size) {
		memset(bh->b_data, 0, blocksize);
	} else if (vbo + blocksize > valid_size) {
		u32 voff = valid_size & sbi->block_mask;

		memset(bh->b_data + voff, 0, blocksize - voff);
	}

	bbuf->buf = (ulong *)bh->b_data;
	bbuf->bit = 8 * (off & ~(size_t)sbi->block_mask);
	bbuf->nbits = 8 * blocksize;

	return 0;
}

static void bmp_buf_put(struct bmp_buf *bbuf, bool dirty)
{
	struct buffer_head *bh = bbuf->bh;
	struct ATTRIB *b = bbuf->b;

	if (!bh) {
		if (b && !b->non_res && dirty)
			bbuf->mi->dirty = true;
		return;
	}

	if (!dirty)
		goto out;

	if (bbuf->new_valid) {
		b->nres.valid_size = cpu_to_le64(bbuf->new_valid);
		bbuf->mi->dirty = true;
	}

	set_buffer_uptodate(bh);
	mark_buffer_dirty(bh);

out:
	unlock_buffer(bh);
	put_bh(bh);
}

/*
 * indx_mark_used - Mark the bit @bit as used.
 */
static int indx_mark_used(struct ntfs_index *indx, struct ntfs_inode *ni,
			  size_t bit)
{
	int err;
	struct bmp_buf bbuf;

	err = bmp_buf_get(indx, ni, bit, &bbuf);
	if (err)
		return err;

	__set_bit(bit - bbuf.bit, bbuf.buf);

	bmp_buf_put(&bbuf, true);

	return 0;
}

/*
 * indx_mark_free - Mark the bit @bit as free.
 */
static int indx_mark_free(struct ntfs_index *indx, struct ntfs_inode *ni,
			  size_t bit)
{
	int err;
	struct bmp_buf bbuf;

	err = bmp_buf_get(indx, ni, bit, &bbuf);
	if (err)
		return err;

	__clear_bit(bit - bbuf.bit, bbuf.buf);

	bmp_buf_put(&bbuf, true);

	return 0;
}

/*
 * scan_nres_bitmap
 *
 * If ntfs_readdir calls this function (indx_used_bit -> scan_nres_bitmap),
 * inode is shared locked and no ni_lock.
 * Use rw_semaphore for read/write access to bitmap_run.
 */
static int scan_nres_bitmap(struct ntfs_inode *ni, struct ATTRIB *bitmap,
			    struct ntfs_index *indx, size_t from,
			    bool (*fn)(const ulong *buf, u32 bit, u32 bits,
				       size_t *ret),
			    size_t *ret)
{
	struct ntfs_sb_info *sbi = ni->mi.sbi;
	struct super_block *sb = sbi->sb;
	struct runs_tree *run = &indx->bitmap_run;
	struct rw_semaphore *lock = &indx->run_lock;
	u32 nbits = sb->s_blocksize * 8;
	u32 blocksize = sb->s_blocksize;
	u64 valid_size = le64_to_cpu(bitmap->nres.valid_size);
	u64 data_size = le64_to_cpu(bitmap->nres.data_size);
	sector_t eblock = bytes_to_block(sb, data_size);
	size_t vbo = from >> 3;
	sector_t blk = (vbo & sbi->cluster_mask) >> sb->s_blocksize_bits;
	sector_t vblock = vbo >> sb->s_blocksize_bits;
	sector_t blen, block;
	CLST lcn, clen, vcn, vcn_next;
	size_t idx;
	struct buffer_head *bh;
	bool ok;

	*ret = MINUS_ONE_T;

	if (vblock >= eblock)
		return 0;

	from &= nbits - 1;
	vcn = vbo >> sbi->cluster_bits;

	down_read(lock);
	ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
	up_read(lock);

next_run:
	if (!ok) {
		int err;
		const struct INDEX_NAMES *name = &s_index_names[indx->type];

		down_write(lock);
		err = attr_load_runs_vcn(ni, ATTR_BITMAP, name->name,
					 name->name_len, run, vcn);
		up_write(lock);
		if (err)
			return err;
		down_read(lock);
		ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
		up_read(lock);
		if (!ok)
			return -EINVAL;
	}

	blen = (sector_t)clen * sbi->blocks_per_cluster;
	block = (sector_t)lcn * sbi->blocks_per_cluster;

	for (; blk < blen; blk++, from = 0) {
		bh = ntfs_bread(sb, block + blk);
		if (!bh)
			return -EIO;

		vbo = (u64)vblock << sb->s_blocksize_bits;
		if (vbo >= valid_size) {
			memset(bh->b_data, 0, blocksize);
		} else if (vbo + blocksize > valid_size) {
			u32 voff = valid_size & sbi->block_mask;

			memset(bh->b_data + voff, 0, blocksize - voff);
		}

		if (vbo + blocksize > data_size)
			nbits = 8 * (data_size - vbo);

		ok = nbits > from ? (*fn)((ulong *)bh->b_data, from, nbits, ret)
				  : false;
		put_bh(bh);

		if (ok) {
			*ret += 8 * vbo;
			return 0;
		}

		if (++vblock >= eblock) {
			*ret = MINUS_ONE_T;
			return 0;
		}
	}
	blk = 0;
	vcn_next = vcn + clen;
	down_read(lock);
	ok = run_get_entry(run, ++idx, &vcn, &lcn, &clen) && vcn == vcn_next;
	if (!ok)
		vcn = vcn_next;
	up_read(lock);
	goto next_run;
}

static bool scan_for_free(const ulong *buf, u32 bit, u32 bits, size_t *ret)
{
	size_t pos = find_next_zero_bit(buf, bits, bit);

	if (pos >= bits)
		return false;
	*ret = pos;
	return true;
}

/*
 * indx_find_free - Look for free bit.
 *
 * Return: -1 if no free bits.
 */
static int indx_find_free(struct ntfs_index *indx, struct ntfs_inode *ni,
			  size_t *bit, struct ATTRIB **bitmap)
{
	struct ATTRIB *b;
	struct ATTR_LIST_ENTRY *le = NULL;
	const struct INDEX_NAMES *in = &s_index_names[indx->type];
	int err;

	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
			 NULL, NULL);

	if (!b)
		return -ENOENT;

	*bitmap = b;
	*bit = MINUS_ONE_T;

	if (!b->non_res) {
		u32 nbits = 8 * le32_to_cpu(b->res.data_size);
		size_t pos = find_next_zero_bit(resident_data(b), nbits, 0);

		if (pos < nbits)
			*bit = pos;
	} else {
		err = scan_nres_bitmap(ni, b, indx, 0, &scan_for_free, bit);

		if (err)
			return err;
	}

	return 0;
}

static bool scan_for_used(const ulong *buf, u32 bit, u32 bits, size_t *ret)
{
	size_t pos = find_next_bit(buf, bits, bit);

	if (pos >= bits)
		return false;
	*ret = pos;
	return true;
}

/*
 * indx_used_bit - Look for used bit.
 *
 * Return: MINUS_ONE_T if no used bits.
 */
int indx_used_bit(struct ntfs_index *indx, struct ntfs_inode *ni, size_t *bit)
{
	struct ATTRIB *b;
	struct ATTR_LIST_ENTRY *le = NULL;
	size_t from = *bit;
	const struct INDEX_NAMES *in = &s_index_names[indx->type];
	int err;

	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
			 NULL, NULL);

	if (!b)
		return -ENOENT;

	*bit = MINUS_ONE_T;

	if (!b->non_res) {
		u32 nbits = le32_to_cpu(b->res.data_size) * 8;
		size_t pos = find_next_bit(resident_data(b), nbits, from);

		if (pos < nbits)
			*bit = pos;
	} else {
		err = scan_nres_bitmap(ni, b, indx, from, &scan_for_used, bit);
		if (err)
			return err;
	}

	return 0;
}

/*
 * hdr_find_split
 *
 * Find a point at which the index allocation buffer would like to be split.
 * NOTE: This function should never return 'END' entry NULL returns on error.
 */
static const struct NTFS_DE *hdr_find_split(const struct INDEX_HDR *hdr)
{
	size_t o;
	const struct NTFS_DE *e = hdr_first_de(hdr);
	u32 used_2 = le32_to_cpu(hdr->used) >> 1;
	u16 esize;

	if (!e || de_is_last(e))
		return NULL;

	esize = le16_to_cpu(e->size);
	for (o = le32_to_cpu(hdr->de_off) + esize; o < used_2; o += esize) {
		const struct NTFS_DE *p = e;

		e = Add2Ptr(hdr, o);

		/* We must not return END entry. */
		if (de_is_last(e))
			return p;

		esize = le16_to_cpu(e->size);
	}

	return e;
}

/*
 * hdr_insert_head - Insert some entries at the beginning of the buffer.
 *
 * It is used to insert entries into a newly-created buffer.
 */
static const struct NTFS_DE *hdr_insert_head(struct INDEX_HDR *hdr,
					     const void *ins, u32 ins_bytes)
{
	u32 to_move;
	struct NTFS_DE *e = hdr_first_de(hdr);
	u32 used = le32_to_cpu(hdr->used);

	if (!e)
		return NULL;

	/* Now we just make room for the inserted entries and jam it in. */
	to_move = used - le32_to_cpu(hdr->de_off);
	memmove(Add2Ptr(e, ins_bytes), e, to_move);
	memcpy(e, ins, ins_bytes);
	hdr->used = cpu_to_le32(used + ins_bytes);

	return e;
}

void fnd_clear(struct ntfs_fnd *fnd)
{
	int i;

	for (i = 0; i < fnd->level; i++) {
		struct indx_node *n = fnd->nodes[i];

		if (!n)
			continue;

		put_indx_node(n);
		fnd->nodes[i] = NULL;
	}
	fnd->level = 0;
	fnd->root_de = NULL;
}

static int fnd_push(struct ntfs_fnd *fnd, struct indx_node *n,
		    struct NTFS_DE *e)
{
	int i;

	i = fnd->level;
	if (i < 0 || i >= ARRAY_SIZE(fnd->nodes))
		return -EINVAL;
	fnd->nodes[i] = n;
	fnd->de[i] = e;
	fnd->level += 1;
	return 0;
}

static struct indx_node *fnd_pop(struct ntfs_fnd *fnd)
{
	struct indx_node *n;
	int i = fnd->level;

	i -= 1;
	n = fnd->nodes[i];
	fnd->nodes[i] = NULL;
	fnd->level = i;

	return n;
}

static bool fnd_is_empty(struct ntfs_fnd *fnd)
{
	if (!fnd->level)
		return !fnd->root_de;

	return !fnd->de[fnd->level - 1];
}

/*
 * hdr_find_e - Locate an entry the index buffer.
 *
 * If no matching entry is found, it returns the first entry which is greater
 * than the desired entry If the search key is greater than all the entries the
 * buffer, it returns the 'end' entry. This function does a binary search of the
 * current index buffer, for the first entry that is <= to the search value.
 *
 * Return: NULL if error.
 */
static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx,
				  const struct INDEX_HDR *hdr, const void *key,
				  size_t key_len, const void *ctx, int *diff)
{
	struct NTFS_DE *e, *found = NULL;
	NTFS_CMP_FUNC cmp = indx->cmp;
	int min_idx = 0, mid_idx, max_idx = 0;
	int diff2;
	int table_size = 8;
	u32 e_size, e_key_len;
	u32 end = le32_to_cpu(hdr->used);
	u32 off = le32_to_cpu(hdr->de_off);
	u16 offs[128];

fill_table:
	if (off + sizeof(struct NTFS_DE) > end)
		return NULL;

	e = Add2Ptr(hdr, off);
	e_size = le16_to_cpu(e->size);

	if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)
		return NULL;

	if (!de_is_last(e)) {
		offs[max_idx] = off;
		off += e_size;

		max_idx++;
		if (max_idx < table_size)
			goto fill_table;

		max_idx--;
	}

binary_search:
	e_key_len = le16_to_cpu(e->key_size);

	diff2 = (*cmp)(key, key_len, e + 1, e_key_len, ctx);
	if (diff2 > 0) {
		if (found) {
			min_idx = mid_idx + 1;
		} else {
			if (de_is_last(e))
				return NULL;

			max_idx = 0;
			table_size = min(table_size * 2,
					 (int)ARRAY_SIZE(offs));
			goto fill_table;
		}
	} else if (diff2 < 0) {
		if (found)
			max_idx = mid_idx - 1;
		else
			max_idx--;

		found = e;
	} else {
		*diff = 0;
		return e;
	}

	if (min_idx > max_idx) {
		*diff = -1;
		return found;
	}

	mid_idx = (min_idx + max_idx) >> 1;
	e = Add2Ptr(hdr, offs[mid_idx]);

	goto binary_search;
}

/*
 * hdr_insert_de - Insert an index entry into the buffer.
 *
 * 'before' should be a pointer previously returned from hdr_find_e.
 */
static struct NTFS_DE *hdr_insert_de(const struct ntfs_index *indx,
				     struct INDEX_HDR *hdr,
				     const struct NTFS_DE *de,
				     struct NTFS_DE *before, const void *ctx)
{
	int diff;
	size_t off = PtrOffset(hdr, before);
	u32 used = le32_to_cpu(hdr->used);
	u32 total = le32_to_cpu(hdr->total);
	u16 de_size = le16_to_cpu(de->size);

	/* First, check to see if there's enough room. */
	if (used + de_size > total)
		return NULL;

	/* We know there's enough space, so we know we'll succeed. */
	if (before) {
		/* Check that before is inside Index. */
		if (off >= used || off < le32_to_cpu(hdr->de_off) ||
		    off + le16_to_cpu(before->size) > total) {
			return NULL;
		}
		goto ok;
	}
	/* No insert point is applied. Get it manually. */
	before = hdr_find_e(indx, hdr, de + 1, le16_to_cpu(de->key_size), ctx,
			    &diff);
	if (!before)
		return NULL;
	off = PtrOffset(hdr, before);

ok:
	/* Now we just make room for the entry and jam it in. */
	memmove(Add2Ptr(before, de_size), before, used - off);

	hdr->used = cpu_to_le32(used + de_size);
	memcpy(before, de, de_size);

	return before;
}

/*
 * hdr_delete_de - Remove an entry from the index buffer.
 */
static inline struct NTFS_DE *hdr_delete_de(struct INDEX_HDR *hdr,
					    struct NTFS_DE *re)
{
	u32 used = le32_to_cpu(hdr->used);
	u16 esize = le16_to_cpu(re->size);
	u32 off = PtrOffset(hdr, re);
	int bytes = used - (off + esize);

	if (off >= used || esize < sizeof(struct NTFS_DE) ||
	    bytes < sizeof(struct NTFS_DE))
		return NULL;

	hdr->used = cpu_to_le32(used - esize);
	memmove(re, Add2Ptr(re, esize), bytes);

	return re;
}

void indx_clear(struct ntfs_index *indx)
{
	run_close(&indx->alloc_run);
	run_close(&indx->bitmap_run);
}

int indx_init(struct ntfs_index *indx, struct ntfs_sb_info *sbi,
	      const struct ATTRIB *attr, enum index_mutex_classed type)
{
	u32 t32;
	const struct INDEX_ROOT *root = resident_data(attr);

	/* Check root fields. */
	if (!root->index_block_clst)
		return -EINVAL;

	indx->type = type;
	indx->idx2vbn_bits = __ffs(root->index_block_clst);

	t32 = le32_to_cpu(root->index_block_size);
	indx->index_bits = blksize_bits(t32);

	/* Check index record size. */
	if (t32 < sbi->cluster_size) {
		/* Index record is smaller than a cluster, use 512 blocks. */
		if (t32 != root->index_block_clst * SECTOR_SIZE)
			return -EINVAL;

		/* Check alignment to a cluster. */
		if ((sbi->cluster_size >> SECTOR_SHIFT) &
		    (root->index_block_clst - 1)) {
			return -EINVAL;
		}

		indx->vbn2vbo_bits = SECTOR_SHIFT;
	} else {
		/* Index record must be a multiple of cluster size. */
		if (t32 != root->index_block_clst << sbi->cluster_bits)
			return -EINVAL;

		indx->vbn2vbo_bits = sbi->cluster_bits;
	}

	init_rwsem(&indx->run_lock);

	indx->cmp = get_cmp_func(root);
	return indx->cmp ? 0 : -EINVAL;
}

static struct indx_node *indx_new(struct ntfs_index *indx,
				  struct ntfs_inode *ni, CLST vbn,
				  const __le64 *sub_vbn)
{
	int err;
	struct NTFS_DE *e;
	struct indx_node *r;
	struct INDEX_HDR *hdr;
	struct INDEX_BUFFER *index;
	u64 vbo = (u64)vbn << indx->vbn2vbo_bits;
	u32 bytes = 1u << indx->index_bits;
	u16 fn;
	u32 eo;

	r = kzalloc(sizeof(struct indx_node), GFP_NOFS);
	if (!r)
		return ERR_PTR(-ENOMEM);

	index = kzalloc(bytes, GFP_NOFS);
	if (!index) {
		kfree(r);
		return ERR_PTR(-ENOMEM);
	}

	err = ntfs_get_bh(ni->mi.sbi, &indx->alloc_run, vbo, bytes, &r->nb);

	if (err) {
		kfree(index);
		kfree(r);
		return ERR_PTR(err);
	}

	/* Create header. */
	index->rhdr.sign = NTFS_INDX_SIGNATURE;
	index->rhdr.fix_off = cpu_to_le16(sizeof(struct INDEX_BUFFER)); // 0x28
	fn = (bytes >> SECTOR_SHIFT) + 1; // 9
	index->rhdr.fix_num = cpu_to_le16(fn);
	index->vbn = cpu_to_le64(vbn);
	hdr = &index->ihdr;
	eo = ALIGN(sizeof(struct INDEX_BUFFER) + fn * sizeof(short), 8);
	hdr->de_off = cpu_to_le32(eo);

	e = Add2Ptr(hdr, eo);

	if (sub_vbn) {
		e->flags = NTFS_IE_LAST | NTFS_IE_HAS_SUBNODES;
		e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
		hdr->used =
			cpu_to_le32(eo + sizeof(struct NTFS_DE) + sizeof(u64));
		de_set_vbn_le(e, *sub_vbn);
		hdr->flags = 1;
	} else {
		e->size = cpu_to_le16(sizeof(struct NTFS_DE));
		hdr->used = cpu_to_le32(eo + sizeof(struct NTFS_DE));
		e->flags = NTFS_IE_LAST;
	}

	hdr->total = cpu_to_le32(bytes - offsetof(struct INDEX_BUFFER, ihdr));

	r->index = index;
	return r;
}

struct INDEX_ROOT *indx_get_root(struct ntfs_index *indx, struct ntfs_inode *ni,
				 struct ATTRIB **attr, struct mft_inode **mi)
{
	struct ATTR_LIST_ENTRY *le = NULL;
	struct ATTRIB *a;
	const struct INDEX_NAMES *in = &s_index_names[indx->type];

	a = ni_find_attr(ni, NULL, &le, ATTR_ROOT, in->name, in->name_len, NULL,
			 mi);
	if (!a)
		return NULL;

	if (attr)
		*attr = a;

	return resident_data_ex(a, sizeof(struct INDEX_ROOT));
}

static int indx_write(struct ntfs_index *indx, struct ntfs_inode *ni,
		      struct indx_node *node, int sync)
{
	struct INDEX_BUFFER *ib = node->index;

	return ntfs_write_bh(ni->mi.sbi, &ib->rhdr, &node->nb, sync);
}

/*
 * indx_read
 *
 * If ntfs_readdir calls this function
 * inode is shared locked and no ni_lock.
 * Use rw_semaphore for read/write access to alloc_run.
 */
int indx_read(struct ntfs_index *indx, struct ntfs_inode *ni, CLST vbn,
	      struct indx_node **node)
{
	int err;
	struct INDEX_BUFFER *ib;
	struct runs_tree *run = &indx->alloc_run;
	struct rw_semaphore *lock = &indx->run_lock;
	u64 vbo = (u64)vbn << indx->vbn2vbo_bits;
	u32 bytes = 1u << indx->index_bits;
	struct indx_node *in = *node;
	const struct INDEX_NAMES *name;

	if (!in) {
		in = kzalloc(sizeof(struct indx_node), GFP_NOFS);
		if (!in)
			return -ENOMEM;
	} else {
		nb_put(&in->nb);
	}

	ib = in->index;
	if (!ib) {
		ib = kmalloc(bytes, GFP_NOFS);
		if (!ib) {
			err = -ENOMEM;
			goto out;
		}
	}

	down_read(lock);
	err = ntfs_read_bh(ni->mi.sbi, run, vbo, &ib->rhdr, bytes, &in->nb);
	up_read(lock);
	if (!err)
		goto ok;

	if (err == -E_NTFS_FIXUP)
		goto ok;

	if (err != -ENOENT)
		goto out;

	name = &s_index_names[indx->type];
	down_write(lock);
	err = attr_load_runs_range(ni, ATTR_ALLOC, name->name, name->name_len,
				   run, vbo, vbo + bytes);
	up_write(lock);
	if (err)
		goto out;

	down_read(lock);
	err = ntfs_read_bh(ni->mi.sbi, run, vbo, &ib->rhdr, bytes, &in->nb);
	up_read(lock);
	if (err == -E_NTFS_FIXUP)
		goto ok;

	if (err)
		goto out;

ok:
	if (err == -E_NTFS_FIXUP) {
		ntfs_write_bh(ni->mi.sbi, &ib->rhdr, &in->nb, 0);
		err = 0;
	}

	in->index = ib;
	*node = in;

out:
	if (ib != in->index)
		kfree(ib);

	if (*node != in) {
		nb_put(&in->nb);
		kfree(in);
	}

	return err;
}

/*
 * indx_find - Scan NTFS directory for given entry.
 */
int indx_find(struct ntfs_index *indx, struct ntfs_inode *ni,
	      const struct INDEX_ROOT *root, const void *key, size_t key_len,
	      const void *ctx, int *diff, struct NTFS_DE **entry,
	      struct ntfs_fnd *fnd)
{
	int err;
	struct NTFS_DE *e;
	struct indx_node *node;

	if (!root)
		root = indx_get_root(&ni->dir, ni, NULL, NULL);

	if (!root) {
		/* Should not happen. */
		return -EINVAL;
	}

	/* Check cache. */
	e = fnd->level ? fnd->de[fnd->level - 1] : fnd->root_de;
	if (e && !de_is_last(e) &&
	    !(*indx->cmp)(key, key_len, e + 1, le16_to_cpu(e->key_size), ctx)) {
		*entry = e;
		*diff = 0;
		return 0;
	}

	/* Soft finder reset. */
	fnd_clear(fnd);

	/* Lookup entry that is <= to the search value. */
	e = hdr_find_e(indx, &root->ihdr, key, key_len, ctx, diff);
	if (!e)
		return -EINVAL;

	fnd->root_de = e;

	for (;;) {
		node = NULL;
		if (*diff >= 0 || !de_has_vcn_ex(e))
			break;

		/* Read next level. */
		err = indx_read(indx, ni, de_get_vbn(e), &node);
		if (err)
			return err;

		/* Lookup entry that is <= to the search value. */
		e = hdr_find_e(indx, &node->index->ihdr, key, key_len, ctx,
			       diff);
		if (!e) {
			put_indx_node(node);
			return -EINVAL;
		}

		fnd_push(fnd, node, e);
	}

	*entry = e;
	return 0;
}

int indx_find_sort(struct ntfs_index *indx, struct ntfs_inode *ni,
		   const struct INDEX_ROOT *root, struct NTFS_DE **entry,
		   struct ntfs_fnd *fnd)
{
	int err;
	struct indx_node *n = NULL;
	struct NTFS_DE *e;
	size_t iter = 0;
	int level = fnd->level;

	if (!*entry) {
		/* Start find. */
		e = hdr_first_de(&root->ihdr);
		if (!e)
			return 0;
		fnd_clear(fnd);
		fnd->root_de = e;
	} else if (!level) {
		if (de_is_last(fnd->root_de)) {
			*entry = NULL;
			return 0;
		}

		e = hdr_next_de(&root->ihdr, fnd->root_de);
		if (!e)
			return -EINVAL;
		fnd->root_de = e;
	} else {
		n = fnd->nodes[level - 1];
		e = fnd->de[level - 1];

		if (de_is_last(e))
			goto pop_level;

		e = hdr_next_de(&n->index->ihdr, e);
		if (!e)
			return -EINVAL;

		fnd->de[level - 1] = e;
	}

	/* Just to avoid tree cycle. */
next_iter:
	if (iter++ >= 1000)
		return -EINVAL;

	while (de_has_vcn_ex(e)) {
		if (le16_to_cpu(e->size) <
		    sizeof(struct NTFS_DE) + sizeof(u64)) {
			if (n) {
				fnd_pop(fnd);
				kfree(n);
			}
			return -EINVAL;
		}

		/* Read next level. */
		err = indx_read(indx, ni, de_get_vbn(e), &n);
		if (err)
			return err;

		/* Try next level. */
		e = hdr_first_de(&n->index->ihdr);
		if (!e) {
			kfree(n);
			return -EINVAL;
		}

		fnd_push(fnd, n, e);
	}

	if (le16_to_cpu(e->size) > sizeof(struct NTFS_DE)) {
		*entry = e;
		return 0;
	}

pop_level:
	for (;;) {
		if (!de_is_last(e))
			goto next_iter;

		/* Pop one level. */
		if (n) {
			fnd_pop(fnd);
			kfree(n);
		}

		level = fnd->level;

		if (level) {
			n = fnd->nodes[level - 1];
			e = fnd->de[level - 1];
		} else if (fnd->root_de) {
			n = NULL;
			e = fnd->root_de;
			fnd->root_de = NULL;
		} else {
			*entry = NULL;
			return 0;
		}

		if (le16_to_cpu(e->size) > sizeof(struct NTFS_DE)) {
			*entry = e;
			if (!fnd->root_de)
				fnd->root_de = e;
			return 0;
		}
	}
}

int indx_find_raw(struct ntfs_index *indx, struct ntfs_inode *ni,
		  const struct INDEX_ROOT *root, struct NTFS_DE **entry,
		  size_t *off, struct ntfs_fnd *fnd)
{
	int err;
	struct indx_node *n = NULL;
	struct NTFS_DE *e = NULL;
	struct NTFS_DE *e2;
	size_t bit;
	CLST next_used_vbn;
	CLST next_vbn;
	u32 record_size = ni->mi.sbi->record_size;

	/* Use non sorted algorithm. */
	if (!*entry) {
		/* This is the first call. */
		e = hdr_first_de(&root->ihdr);
		if (!e)
			return 0;
		fnd_clear(fnd);
		fnd->root_de = e;

		/* The first call with setup of initial element. */
		if (*off >= record_size) {
			next_vbn = (((*off - record_size) >> indx->index_bits))
				   << indx->idx2vbn_bits;
			/* Jump inside cycle 'for'. */
			goto next;
		}

		/* Start enumeration from root. */
		*off = 0;
	} else if (!fnd->root_de)
		return -EINVAL;

	for (;;) {
		/* Check if current entry can be used. */
		if (e && le16_to_cpu(e->size) > sizeof(struct NTFS_DE))
			goto ok;

		if (!fnd->level) {
			/* Continue to enumerate root. */
			if (!de_is_last(fnd->root_de)) {
				e = hdr_next_de(&root->ihdr, fnd->root_de);
				if (!e)
					return -EINVAL;
				fnd->root_de = e;
				continue;
			}

			/* Start to enumerate indexes from 0. */
			next_vbn = 0;
		} else {
			/* Continue to enumerate indexes. */
			e2 = fnd->de[fnd->level - 1];

			n = fnd->nodes[fnd->level - 1];

			if (!de_is_last(e2)) {
				e = hdr_next_de(&n->index->ihdr, e2);
				if (!e)
					return -EINVAL;
				fnd->de[fnd->level - 1] = e;
				continue;
			}

			/* Continue with next index. */
			next_vbn = le64_to_cpu(n->index->vbn) +
				   root->index_block_clst;
		}

next:
		/* Release current index. */
		if (n) {
			fnd_pop(fnd);
			put_indx_node(n);
			n = NULL;
		}

		/* Skip all free indexes. */
		bit = next_vbn >> indx->idx2vbn_bits;
		err = indx_used_bit(indx, ni, &bit);
		if (err == -ENOENT || bit == MINUS_ONE_T) {
			/* No used indexes. */
			*entry = NULL;
			return 0;
		}

		next_used_vbn = bit << indx->idx2vbn_bits;

		/* Read buffer into memory. */
		err = indx_read(indx, ni, next_used_vbn, &n);
		if (err)
			return err;

		e = hdr_first_de(&n->index->ihdr);
		fnd_push(fnd, n, e);
		if (!e)
			return -EINVAL;
	}

ok:
	/* Return offset to restore enumerator if necessary. */
	if (!n) {
		/* 'e' points in root, */
		*off = PtrOffset(&root->ihdr, e);
	} else {
		/* 'e' points in index, */
		*off = (le64_to_cpu(n->index->vbn) << indx->vbn2vbo_bits) +
		       record_size + PtrOffset(&n->index->ihdr, e);
	}

	*entry = e;
	return 0;
}

/*
 * indx_create_allocate - Create "Allocation + Bitmap" attributes.
 */
static int indx_create_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
				CLST *vbn)
{
	int err;
	struct ntfs_sb_info *sbi = ni->mi.sbi;
	struct ATTRIB *bitmap;
	struct ATTRIB *alloc;
	u32 data_size = 1u << indx->index_bits;
	u32 alloc_size = ntfs_up_cluster(sbi, data_size);
	CLST len = alloc_size >> sbi->cluster_bits;
	const struct INDEX_NAMES *in = &s_index_names[indx->type];
	CLST alen;
	struct runs_tree run;

	run_init(&run);

	err = attr_allocate_clusters(sbi, &run, 0, 0, len, NULL, 0, &alen, 0,
				     NULL);
	if (err)
		goto out;

	err = ni_insert_nonresident(ni, ATTR_ALLOC, in->name, in->name_len,
				    &run, 0, len, 0, &alloc, NULL, NULL);
	if (err)
		goto out1;

	alloc->nres.valid_size = alloc->nres.data_size = cpu_to_le64(data_size);

	err = ni_insert_resident(ni, bitmap_size(1), ATTR_BITMAP, in->name,
				 in->name_len, &bitmap, NULL, NULL);
	if (err)
		goto out2;

	if (in->name == I30_NAME) {
		ni->vfs_inode.i_size = data_size;
		inode_set_bytes(&ni->vfs_inode, alloc_size);
	}

	memcpy(&indx->alloc_run, &run, sizeof(run));

	*vbn = 0;

	return 0;

out2:
	mi_remove_attr(NULL, &ni->mi, alloc);

out1:
	run_deallocate(sbi, &run, false);

out:
	return err;
}

/*
 * indx_add_allocate - Add clusters to index.
 */
static int indx_add_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
			     CLST *vbn)
{
	int err;
	size_t bit;
	u64 data_size;
	u64 bmp_size, bmp_size_v;
	struct ATTRIB *bmp, *alloc;
	struct mft_inode *mi;
	const struct INDEX_NAMES *in = &s_index_names[indx->type];

	err = indx_find_free(indx, ni, &bit, &bmp);
	if (err)
		goto out1;

	if (bit != MINUS_ONE_T) {
		bmp = NULL;
	} else {
		if (bmp->non_res) {
			bmp_size = le64_to_cpu(bmp->nres.data_size);
			bmp_size_v = le64_to_cpu(bmp->nres.valid_size);
		} else {
			bmp_size = bmp_size_v = le32_to_cpu(bmp->res.data_size);
		}

		bit = bmp_size << 3;
	}

	data_size = (u64)(bit + 1) << indx->index_bits;

	if (bmp) {
		/* Increase bitmap. */
		err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
				    &indx->bitmap_run, bitmap_size(bit + 1),
				    NULL, true, NULL);
		if (err)
			goto out1;
	}

	alloc = ni_find_attr(ni, NULL, NULL, ATTR_ALLOC, in->name, in->name_len,
			     NULL, &mi);
	if (!alloc) {
		err = -EINVAL;
		if (bmp)
			goto out2;
		goto out1;
	}

	/* Increase allocation. */
	err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
			    &indx->alloc_run, data_size, &data_size, true,
			    NULL);
	if (err) {
		if (bmp)
			goto out2;
		goto out1;
	}

	*vbn = bit << indx->idx2vbn_bits;

	return 0;

out2:
	/* Ops. No space? */
	attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
		      &indx->bitmap_run, bmp_size, &bmp_size_v, false, NULL);

out1:
	return err;
}

/*
 * indx_insert_into_root - Attempt to insert an entry into the index root.
 *
 * @undo - True if we undoing previous remove.
 * If necessary, it will twiddle the index b-tree.
 */
static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
				 const struct NTFS_DE *new_de,
				 struct NTFS_DE *root_de, const void *ctx,
				 struct ntfs_fnd *fnd, bool undo)
{
	int err = 0;
	struct NTFS_DE *e, *e0, *re;
	struct mft_inode *mi;
	struct ATTRIB *attr;
	struct INDEX_HDR *hdr;
	struct indx_node *n;
	CLST new_vbn;
	__le64 *sub_vbn, t_vbn;
	u16 new_de_size;
	u32 hdr_used, hdr_total, asize, to_move;
	u32 root_size, new_root_size;
	struct ntfs_sb_info *sbi;
	int ds_root;
	struct INDEX_ROOT *root, *a_root;

	/* Get the record this root placed in. */
	root = indx_get_root(indx, ni, &attr, &mi);
	if (!root)
		return -EINVAL;

	/*
	 * Try easy case:
	 * hdr_insert_de will succeed if there's
	 * room the root for the new entry.
	 */
	hdr = &root->ihdr;
	sbi = ni->mi.sbi;
	new_de_size = le16_to_cpu(new_de->size);
	hdr_used = le32_to_cpu(hdr->used);
	hdr_total = le32_to_cpu(hdr->total);
	asize = le32_to_cpu(attr->size);
	root_size = le32_to_cpu(attr->res.data_size);

	ds_root = new_de_size + hdr_used - hdr_total;

	/* If 'undo' is set then reduce requirements. */
	if ((undo || asize + ds_root < sbi->max_bytes_per_attr) &&
	    mi_resize_attr(mi, attr, ds_root)) {
		hdr->total = cpu_to_le32(hdr_total + ds_root);
		e = hdr_insert_de(indx, hdr, new_de, root_de, ctx);
		WARN_ON(!e);
		fnd_clear(fnd);
		fnd->root_de = e;

		return 0;
	}

	/* Make a copy of root attribute to restore if error. */
	a_root = kmemdup(attr, asize, GFP_NOFS);
	if (!a_root)
		return -ENOMEM;

	/*
	 * Copy all the non-end entries from
	 * the index root to the new buffer.
	 */
	to_move = 0;
	e0 = hdr_first_de(hdr);

	/* Calculate the size to copy. */
	for (e = e0;; e = hdr_next_de(hdr, e)) {
		if (!e) {
			err = -EINVAL;
			goto out_free_root;
		}

		if (de_is_last(e))
			break;
		to_move += le16_to_cpu(e->size);
	}

	if (!to_move) {
		re = NULL;
	} else {
		re = kmemdup(e0, to_move, GFP_NOFS);
		if (!re) {
			err = -ENOMEM;
			goto out_free_root;
		}
	}

	sub_vbn = NULL;
	if (de_has_vcn(e)) {
		t_vbn = de_get_vbn_le(e);
		sub_vbn = &t_vbn;
	}

	new_root_size = sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE) +
			sizeof(u64);
	ds_root = new_root_size - root_size;

	if (ds_root > 0 && asize + ds_root > sbi->max_bytes_per_attr) {
		/* Make root external. */
		err = -EOPNOTSUPP;
		goto out_free_re;
	}

	if (ds_root)
		mi_resize_attr(mi, attr, ds_root);

	/* Fill first entry (vcn will be set later). */
	e = (struct NTFS_DE *)(root + 1);
	memset(e, 0, sizeof(struct NTFS_DE));
	e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
	e->flags = NTFS_IE_HAS_SUBNODES | NTFS_IE_LAST;

	hdr->flags = 1;
	hdr->used = hdr->total =
		cpu_to_le32(new_root_size - offsetof(struct INDEX_ROOT, ihdr));

	fnd->root_de = hdr_first_de(hdr);
	mi->dirty = true;

	/* Create alloc and bitmap attributes (if not). */
	err = run_is_empty(&indx->alloc_run)
		      ? indx_create_allocate(indx, ni, &new_vbn)
		      : indx_add_allocate(indx, ni, &new_vbn);

	/* Layout of record may be changed, so rescan root. */
	root = indx_get_root(indx, ni, &attr, &mi);
	if (!root) {
		/* Bug? */
		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
		err = -EINVAL;
		goto out_free_re;
	}

	if (err) {
		/* Restore root. */
		if (mi_resize_attr(mi, attr, -ds_root))
			memcpy(attr, a_root, asize);
		else {
			/* Bug? */
			ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
		}
		goto out_free_re;
	}

	e = (struct NTFS_DE *)(root + 1);
	*(__le64 *)(e + 1) = cpu_to_le64(new_vbn);
	mi->dirty = true;

	/* Now we can create/format the new buffer and copy the entries into. */
	n = indx_new(indx, ni, new_vbn, sub_vbn);
	if (IS_ERR(n)) {
		err = PTR_ERR(n);
		goto out_free_re;
	}

	hdr = &n->index->ihdr;
	hdr_used = le32_to_cpu(hdr->used);
	hdr_total = le32_to_cpu(hdr->total);

	/* Copy root entries into new buffer. */
	hdr_insert_head(hdr, re, to_move);

	/* Update bitmap attribute. */
	indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);

	/* Check if we can insert new entry new index buffer. */
	if (hdr_used + new_de_size > hdr_total) {
		/*
		 * This occurs if MFT record is the same or bigger than index
		 * buffer. Move all root new index and have no space to add
		 * new entry classic case when MFT record is 1K and index
		 * buffer 4K the problem should not occurs.
		 */
		kfree(re);
		indx_write(indx, ni, n, 0);

		put_indx_node(n);
		fnd_clear(fnd);
		err = indx_insert_entry(indx, ni, new_de, ctx, fnd, undo);
		goto out_free_root;
	}

	/*
	 * Now root is a parent for new index buffer.
	 * Insert NewEntry a new buffer.
	 */
	e = hdr_insert_de(indx, hdr, new_de, NULL, ctx);
	if (!e) {
		err = -EINVAL;
		goto out_put_n;
	}
	fnd_push(fnd, n, e);

	/* Just write updates index into disk. */
	indx_write(indx, ni, n, 0);

	n = NULL;

out_put_n:
	put_indx_node(n);
out_free_re:
	kfree(re);
out_free_root:
	kfree(a_root);
	return err;
}

/*
 * indx_insert_into_buffer
 *
 * Attempt to insert an entry into an Index Allocation Buffer.
 * If necessary, it will split the buffer.
 */
static int
indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
			struct INDEX_ROOT *root, const struct NTFS_DE *new_de,
			const void *ctx, int level, struct ntfs_fnd *fnd)
{
	int err;
	const struct NTFS_DE *sp;
	struct NTFS_DE *e, *de_t, *up_e;
	struct indx_node *n2;
	struct indx_node *n1 = fnd->nodes[level];
	struct INDEX_HDR *hdr1 = &n1->index->ihdr;
	struct INDEX_HDR *hdr2;
	u32 to_copy, used;
	CLST new_vbn;
	__le64 t_vbn, *sub_vbn;
	u16 sp_size;

	/* Try the most easy case. */
	e = fnd->level - 1 == level ? fnd->de[level] : NULL;
	e = hdr_insert_de(indx, hdr1, new_de, e, ctx);
	fnd->de[level] = e;
	if (e) {
		/* Just write updated index into disk. */
		indx_write(indx, ni, n1, 0);
		return 0;
	}

	/*
	 * No space to insert into buffer. Split it.
	 * To split we:
	 *  - Save split point ('cause index buffers will be changed)
	 * - Allocate NewBuffer and copy all entries <= sp into new buffer
	 * - Remove all entries (sp including) from TargetBuffer
	 * - Insert NewEntry into left or right buffer (depending on sp <=>
	 *     NewEntry)
	 * - Insert sp into parent buffer (or root)
	 * - Make sp a parent for new buffer
	 */
	sp = hdr_find_split(hdr1);
	if (!sp)
		return -EINVAL;

	sp_size = le16_to_cpu(sp->size);
	up_e = kmalloc(sp_size + sizeof(u64), GFP_NOFS);
	if (!up_e)
		return -ENOMEM;
	memcpy(up_e, sp, sp_size);

	if (!hdr1->flags) {
		up_e->flags |= NTFS_IE_HAS_SUBNODES;
		up_e->size = cpu_to_le16(sp_size + sizeof(u64));
		sub_vbn = NULL;
	} else {
		t_vbn = de_get_vbn_le(up_e);
		sub_vbn = &t_vbn;
	}

	/* Allocate on disk a new index allocation buffer. */
	err = indx_add_allocate(indx, ni, &new_vbn);
	if (err)
		goto out;

	/* Allocate and format memory a new index buffer. */
	n2 = indx_new(indx, ni, new_vbn, sub_vbn);
	if (IS_ERR(n2)) {
		err = PTR_ERR(n2);
		goto out;
	}

	hdr2 = &n2->index->ihdr;

	/* Make sp a parent for new buffer. */
	de_set_vbn(up_e, new_vbn);

	/* Copy all the entries <= sp into the new buffer. */
	de_t = hdr_first_de(hdr1);
	to_copy = PtrOffset(de_t, sp);
	hdr_insert_head(hdr2, de_t, to_copy);

	/* Remove all entries (sp including) from hdr1. */
	used = le32_to_cpu(hdr1->used) - to_copy - sp_size;
	memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off));
	hdr1->used = cpu_to_le32(used);

	/*
	 * Insert new entry into left or right buffer
	 * (depending on sp <=> new_de).
	 */
	hdr_insert_de(indx,
		      (*indx->cmp)(new_de + 1, le16_to_cpu(new_de->key_size),
				   up_e + 1, le16_to_cpu(up_e->key_size),
				   ctx) < 0
			      ? hdr2
			      : hdr1,
		      new_de, NULL, ctx);

	indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);

	indx_write(indx, ni, n1, 0);
	indx_write(indx, ni, n2, 0);

	put_indx_node(n2);

	/*
	 * We've finished splitting everybody, so we are ready to
	 * insert the promoted entry into the parent.
	 */
	if (!level) {
		/* Insert in root. */
		err = indx_insert_into_root(indx, ni, up_e, NULL, ctx, fnd, 0);
		if (err)
			goto out;
	} else {
		/*
		 * The target buffer's parent is another index buffer.
		 * TODO: Remove recursion.
		 */
		err = indx_insert_into_buffer(indx, ni, root, up_e, ctx,
					      level - 1, fnd);
		if (err)
			goto out;
	}

out:
	kfree(up_e);

	return err;
}

/*
 * indx_insert_entry - Insert new entry into index.
 *
 * @undo - True if we undoing previous remove.
 */
int indx_insert_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
		      const struct NTFS_DE *new_de, const void *ctx,
		      struct ntfs_fnd *fnd, bool undo)
{
	int err;
	int diff;
	struct NTFS_DE *e;
	struct ntfs_fnd *fnd_a = NULL;
	struct INDEX_ROOT *root;

	if (!fnd) {
		fnd_a = fnd_get();
		if (!fnd_a) {
			err = -ENOMEM;
			goto out1;
		}
		fnd = fnd_a;
	}

	root = indx_get_root(indx, ni, NULL, NULL);
	if (!root) {
		err = -EINVAL;
		goto out;
	}

	if (fnd_is_empty(fnd)) {
		/*
		 * Find the spot the tree where we want to
		 * insert the new entry.
		 */
		err = indx_find(indx, ni, root, new_de + 1,
				le16_to_cpu(new_de->key_size), ctx, &diff, &e,
				fnd);
		if (err)
			goto out;

		if (!diff) {
			err = -EEXIST;
			goto out;
		}
	}

	if (!fnd->level) {
		/*
		 * The root is also a leaf, so we'll insert the
		 * new entry into it.
		 */
		err = indx_insert_into_root(indx, ni, new_de, fnd->root_de, ctx,
					    fnd, undo);
		if (err)
			goto out;
	} else {
		/*
		 * Found a leaf buffer, so we'll insert the new entry into it.
		 */
		err = indx_insert_into_buffer(indx, ni, root, new_de, ctx,
					      fnd->level - 1, fnd);
		if (err)
			goto out;
	}

out:
	fnd_put(fnd_a);
out1:
	return err;
}

/*
 * indx_find_buffer - Locate a buffer from the tree.
 */
static struct indx_node *indx_find_buffer(struct ntfs_index *indx,
					  struct ntfs_inode *ni,
					  const struct INDEX_ROOT *root,
					  __le64 vbn, struct indx_node *n)
{
	int err;
	const struct NTFS_DE *e;
	struct indx_node *r;
	const struct INDEX_HDR *hdr = n ? &n->index->ihdr : &root->ihdr;

	/* Step 1: Scan one level. */
	for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
		if (!e)
			return ERR_PTR(-EINVAL);

		if (de_has_vcn(e) && vbn == de_get_vbn_le(e))
			return n;

		if (de_is_last(e))
			break;
	}

	/* Step2: Do recursion. */
	e = Add2Ptr(hdr, le32_to_cpu(hdr->de_off));
	for (;;) {
		if (de_has_vcn_ex(e)) {
			err = indx_read(indx, ni, de_get_vbn(e), &n);
			if (err)
				return ERR_PTR(err);

			r = indx_find_buffer(indx, ni, root, vbn, n);
			if (r)
				return r;
		}

		if (de_is_last(e))
			break;

		e = Add2Ptr(e, le16_to_cpu(e->size));
	}

	return NULL;
}

/*
 * indx_shrink - Deallocate unused tail indexes.
 */
static int indx_shrink(struct ntfs_index *indx, struct ntfs_inode *ni,
		       size_t bit)
{
	int err = 0;
	u64 bpb, new_data;
	size_t nbits;
	struct ATTRIB *b;
	struct ATTR_LIST_ENTRY *le = NULL;
	const struct INDEX_NAMES *in = &s_index_names[indx->type];

	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
			 NULL, NULL);

	if (!b)
		return -ENOENT;

	if (!b->non_res) {
		unsigned long pos;
		const unsigned long *bm = resident_data(b);

		nbits = (size_t)le32_to_cpu(b->res.data_size) * 8;

		if (bit >= nbits)
			return 0;

		pos = find_next_bit(bm, nbits, bit);
		if (pos < nbits)
			return 0;
	} else {
		size_t used = MINUS_ONE_T;

		nbits = le64_to_cpu(b->nres.data_size) * 8;

		if (bit >= nbits)
			return 0;

		err = scan_nres_bitmap(ni, b, indx, bit, &scan_for_used, &used);
		if (err)
			return err;

		if (used != MINUS_ONE_T)
			return 0;
	}

	new_data = (u64)bit << indx->index_bits;

	err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
			    &indx->alloc_run, new_data, &new_data, false, NULL);
	if (err)
		return err;

	bpb = bitmap_size(bit);
	if (bpb * 8 == nbits)
		return 0;

	err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
			    &indx->bitmap_run, bpb, &bpb, false, NULL);

	return err;
}

static int indx_free_children(struct ntfs_index *indx, struct ntfs_inode *ni,
			      const struct NTFS_DE *e, bool trim)
{
	int err;
	struct indx_node *n = NULL;
	struct INDEX_HDR *hdr;
	CLST vbn = de_get_vbn(e);
	size_t i;

	err = indx_read(indx, ni, vbn, &n);
	if (err)
		return err;

	hdr = &n->index->ihdr;
	/* First, recurse into the children, if any. */
	if (hdr_has_subnode(hdr)) {
		for (e = hdr_first_de(hdr); e; e = hdr_next_de(hdr, e)) {
			indx_free_children(indx, ni, e, false);
			if (de_is_last(e))
				break;
		}
	}

	put_indx_node(n);

	i = vbn >> indx->idx2vbn_bits;
	/*
	 * We've gotten rid of the children; add this buffer to the free list.
	 */
	indx_mark_free(indx, ni, i);

	if (!trim)
		return 0;

	/*
	 * If there are no used indexes after current free index
	 * then we can truncate allocation and bitmap.
	 * Use bitmap to estimate the case.
	 */
	indx_shrink(indx, ni, i + 1);
	return 0;
}

/*
 * indx_get_entry_to_replace
 *
 * Find a replacement entry for a deleted entry.
 * Always returns a node entry:
 * NTFS_IE_HAS_SUBNODES is set the flags and the size includes the sub_vcn.
 */
static int indx_get_entry_to_replace(struct ntfs_index *indx,
				     struct ntfs_inode *ni,
				     const struct NTFS_DE *de_next,
				     struct NTFS_DE **de_to_replace,
				     struct ntfs_fnd *fnd)
{
	int err;
	int level = -1;
	CLST vbn;
	struct NTFS_DE *e, *te, *re;
	struct indx_node *n;
	struct INDEX_BUFFER *ib;

	*de_to_replace = NULL;

	/* Find first leaf entry down from de_next. */
	vbn = de_get_vbn(de_next);
	for (;;) {
		n = NULL;
		err = indx_read(indx, ni, vbn, &n);
		if (err)
			goto out;

		e = hdr_first_de(&n->index->ihdr);
		fnd_push(fnd, n, e);

		if (!de_is_last(e)) {
			/*
			 * This buffer is non-empty, so its first entry
			 * could be used as the replacement entry.
			 */
			level = fnd->level - 1;
		}

		if (!de_has_vcn(e))
			break;

		/* This buffer is a node. Continue to go down. */
		vbn = de_get_vbn(e);
	}

	if (level == -1)
		goto out;

	n = fnd->nodes[level];
	te = hdr_first_de(&n->index->ihdr);
	/* Copy the candidate entry into the replacement entry buffer. */
	re = kmalloc(le16_to_cpu(te->size) + sizeof(u64), GFP_NOFS);
	if (!re) {
		err = -ENOMEM;
		goto out;
	}

	*de_to_replace = re;
	memcpy(re, te, le16_to_cpu(te->size));

	if (!de_has_vcn(re)) {
		/*
		 * The replacement entry we found doesn't have a sub_vcn.
		 * increase its size to hold one.
		 */
		le16_add_cpu(&re->size, sizeof(u64));
		re->flags |= NTFS_IE_HAS_SUBNODES;
	} else {
		/*
		 * The replacement entry we found was a node entry, which
		 * means that all its child buffers are empty. Return them
		 * to the free pool.
		 */
		indx_free_children(indx, ni, te, true);
	}

	/*
	 * Expunge the replacement entry from its former location,
	 * and then write that buffer.
	 */
	ib = n->index;
	e = hdr_delete_de(&ib->ihdr, te);

	fnd->de[level] = e;
	indx_write(indx, ni, n, 0);

	/* Check to see if this action created an empty leaf. */
	if (ib_is_leaf(ib) && ib_is_empty(ib))
		return 0;

out:
	fnd_clear(fnd);
	return err;
}

/*
 * indx_delete_entry - Delete an entry from the index.
 */
int indx_delete_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
		      const void *key, u32 key_len, const void *ctx)
{
	int err, diff;
	struct INDEX_ROOT *root;
	struct INDEX_HDR *hdr;
	struct ntfs_fnd *fnd, *fnd2;
	struct INDEX_BUFFER *ib;
	struct NTFS_DE *e, *re, *next, *prev, *me;
	struct indx_node *n, *n2d = NULL;
	__le64 sub_vbn;
	int level, level2;
	struct ATTRIB *attr;
	struct mft_inode *mi;
	u32 e_size, root_size, new_root_size;
	size_t trim_bit;
	const struct INDEX_NAMES *in;

	fnd = fnd_get();
	if (!fnd) {
		err = -ENOMEM;
		goto out2;
	}

	fnd2 = fnd_get();
	if (!fnd2) {
		err = -ENOMEM;
		goto out1;
	}

	root = indx_get_root(indx, ni, &attr, &mi);
	if (!root) {
		err = -EINVAL;
		goto out;
	}

	/* Locate the entry to remove. */
	err = indx_find(indx, ni, root, key, key_len, ctx, &diff, &e, fnd);
	if (err)
		goto out;

	if (!e || diff) {
		err = -ENOENT;
		goto out;
	}

	level = fnd->level;

	if (level) {
		n = fnd->nodes[level - 1];
		e = fnd->de[level - 1];
		ib = n->index;
		hdr = &ib->ihdr;
	} else {
		hdr = &root->ihdr;
		e = fnd->root_de;
		n = NULL;
	}

	e_size = le16_to_cpu(e->size);

	if (!de_has_vcn_ex(e)) {
		/* The entry to delete is a leaf, so we can just rip it out. */
		hdr_delete_de(hdr, e);

		if (!level) {
			hdr->total = hdr->used;

			/* Shrink resident root attribute. */
			mi_resize_attr(mi, attr, 0 - e_size);
			goto out;
		}

		indx_write(indx, ni, n, 0);

		/*
		 * Check to see if removing that entry made
		 * the leaf empty.
		 */
		if (ib_is_leaf(ib) && ib_is_empty(ib)) {
			fnd_pop(fnd);
			fnd_push(fnd2, n, e);
		}
	} else {
		/*
		 * The entry we wish to delete is a node buffer, so we
		 * have to find a replacement for it.
		 */
		next = de_get_next(e);

		err = indx_get_entry_to_replace(indx, ni, next, &re, fnd2);
		if (err)
			goto out;

		if (re) {
			de_set_vbn_le(re, de_get_vbn_le(e));
			hdr_delete_de(hdr, e);

			err = level ? indx_insert_into_buffer(indx, ni, root,
							      re, ctx,
							      fnd->level - 1,
							      fnd)
				    : indx_insert_into_root(indx, ni, re, e,
							    ctx, fnd, 0);
			kfree(re);

			if (err)
				goto out;
		} else {
			/*
			 * There is no replacement for the current entry.
			 * This means that the subtree rooted at its node
			 * is empty, and can be deleted, which turn means
			 * that the node can just inherit the deleted
			 * entry sub_vcn.
			 */
			indx_free_children(indx, ni, next, true);

			de_set_vbn_le(next, de_get_vbn_le(e));
			hdr_delete_de(hdr, e);
			if (level) {
				indx_write(indx, ni, n, 0);
			} else {
				hdr->total = hdr->used;

				/* Shrink resident root attribute. */
				mi_resize_attr(mi, attr, 0 - e_size);
			}
		}
	}

	/* Delete a branch of tree. */
	if (!fnd2 || !fnd2->level)
		goto out;

	/* Reinit root 'cause it can be changed. */
	root = indx_get_root(indx, ni, &attr, &mi);
	if (!root) {
		err = -EINVAL;
		goto out;
	}

	n2d = NULL;
	sub_vbn = fnd2->nodes[0]->index->vbn;
	level2 = 0;
	level = fnd->level;

	hdr = level ? &fnd->nodes[level - 1]->index->ihdr : &root->ihdr;

	/* Scan current level. */
	for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
		if (!e) {
			err = -EINVAL;
			goto out;
		}

		if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
			break;

		if (de_is_last(e)) {
			e = NULL;
			break;
		}
	}

	if (!e) {
		/* Do slow search from root. */
		struct indx_node *in;

		fnd_clear(fnd);

		in = indx_find_buffer(indx, ni, root, sub_vbn, NULL);
		if (IS_ERR(in)) {
			err = PTR_ERR(in);
			goto out;
		}

		if (in)
			fnd_push(fnd, in, NULL);
	}

	/* Merge fnd2 -> fnd. */
	for (level = 0; level < fnd2->level; level++) {
		fnd_push(fnd, fnd2->nodes[level], fnd2->de[level]);
		fnd2->nodes[level] = NULL;
	}
	fnd2->level = 0;

	hdr = NULL;
	for (level = fnd->level; level; level--) {
		struct indx_node *in = fnd->nodes[level - 1];

		ib = in->index;
		if (ib_is_empty(ib)) {
			sub_vbn = ib->vbn;
		} else {
			hdr = &ib->ihdr;
			n2d = in;
			level2 = level;
			break;
		}
	}

	if (!hdr)
		hdr = &root->ihdr;

	e = hdr_first_de(hdr);
	if (!e) {
		err = -EINVAL;
		goto out;
	}

	if (hdr != &root->ihdr || !de_is_last(e)) {
		prev = NULL;
		while (!de_is_last(e)) {
			if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
				break;
			prev = e;
			e = hdr_next_de(hdr, e);
			if (!e) {
				err = -EINVAL;
				goto out;
			}
		}

		if (sub_vbn != de_get_vbn_le(e)) {
			/*
			 * Didn't find the parent entry, although this buffer
			 * is the parent trail. Something is corrupt.
			 */
			err = -EINVAL;
			goto out;
		}

		if (de_is_last(e)) {
			/*
			 * Since we can't remove the end entry, we'll remove
			 * its predecessor instead. This means we have to
			 * transfer the predecessor's sub_vcn to the end entry.
			 * Note: This index block is not empty, so the
			 * predecessor must exist.
			 */
			if (!prev) {
				err = -EINVAL;
				goto out;
			}

			if (de_has_vcn(prev)) {
				de_set_vbn_le(e, de_get_vbn_le(prev));
			} else if (de_has_vcn(e)) {
				le16_sub_cpu(&e->size, sizeof(u64));
				e->flags &= ~NTFS_IE_HAS_SUBNODES;
				le32_sub_cpu(&hdr->used, sizeof(u64));
			}
			e = prev;
		}

		/*
		 * Copy the current entry into a temporary buffer (stripping
		 * off its down-pointer, if any) and delete it from the current
		 * buffer or root, as appropriate.
		 */
		e_size = le16_to_cpu(e->size);
		me = kmemdup(e, e_size, GFP_NOFS);
		if (!me) {
			err = -ENOMEM;
			goto out;
		}

		if (de_has_vcn(me)) {
			me->flags &= ~NTFS_IE_HAS_SUBNODES;
			le16_sub_cpu(&me->size, sizeof(u64));
		}

		hdr_delete_de(hdr, e);

		if (hdr == &root->ihdr) {
			level = 0;
			hdr->total = hdr->used;

			/* Shrink resident root attribute. */
			mi_resize_attr(mi, attr, 0 - e_size);
		} else {
			indx_write(indx, ni, n2d, 0);
			level = level2;
		}

		/* Mark unused buffers as free. */
		trim_bit = -1;
		for (; level < fnd->level; level++) {
			ib = fnd->nodes[level]->index;
			if (ib_is_empty(ib)) {
				size_t k = le64_to_cpu(ib->vbn) >>
					   indx->idx2vbn_bits;

				indx_mark_free(indx, ni, k);
				if (k < trim_bit)
					trim_bit = k;
			}
		}

		fnd_clear(fnd);
		/*fnd->root_de = NULL;*/

		/*
		 * Re-insert the entry into the tree.
		 * Find the spot the tree where we want to insert the new entry.
		 */
		err = indx_insert_entry(indx, ni, me, ctx, fnd, 0);
		kfree(me);
		if (err)
			goto out;

		if (trim_bit != -1)
			indx_shrink(indx, ni, trim_bit);
	} else {
		/*
		 * This tree needs to be collapsed down to an empty root.
		 * Recreate the index root as an empty leaf and free all
		 * the bits the index allocation bitmap.
		 */
		fnd_clear(fnd);
		fnd_clear(fnd2);

		in = &s_index_names[indx->type];

		err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
				    &indx->alloc_run, 0, NULL, false, NULL);
		err = ni_remove_attr(ni, ATTR_ALLOC, in->name, in->name_len,
				     false, NULL);
		run_close(&indx->alloc_run);

		err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
				    &indx->bitmap_run, 0, NULL, false, NULL);
		err = ni_remove_attr(ni, ATTR_BITMAP, in->name, in->name_len,
				     false, NULL);
		run_close(&indx->bitmap_run);

		root = indx_get_root(indx, ni, &attr, &mi);
		if (!root) {
			err = -EINVAL;
			goto out;
		}

		root_size = le32_to_cpu(attr->res.data_size);
		new_root_size =
			sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE);

		if (new_root_size != root_size &&
		    !mi_resize_attr(mi, attr, new_root_size - root_size)) {
			err = -EINVAL;
			goto out;
		}

		/* Fill first entry. */
		e = (struct NTFS_DE *)(root + 1);
		e->ref.low = 0;
		e->ref.high = 0;
		e->ref.seq = 0;
		e->size = cpu_to_le16(sizeof(struct NTFS_DE));
		e->flags = NTFS_IE_LAST; // 0x02
		e->key_size = 0;
		e->res = 0;

		hdr = &root->ihdr;
		hdr->flags = 0;
		hdr->used = hdr->total = cpu_to_le32(
			new_root_size - offsetof(struct INDEX_ROOT, ihdr));
		mi->dirty = true;
	}

out:
	fnd_put(fnd2);
out1:
	fnd_put(fnd);
out2:
	return err;
}

/*
 * Update duplicated information in directory entry
 * 'dup' - info from MFT record
 */
int indx_update_dup(struct ntfs_inode *ni, struct ntfs_sb_info *sbi,
		    const struct ATTR_FILE_NAME *fname,
		    const struct NTFS_DUP_INFO *dup, int sync)
{
	int err, diff;
	struct NTFS_DE *e = NULL;
	struct ATTR_FILE_NAME *e_fname;
	struct ntfs_fnd *fnd;
	struct INDEX_ROOT *root;
	struct mft_inode *mi;
	struct ntfs_index *indx = &ni->dir;

	fnd = fnd_get();
	if (!fnd)
		return -ENOMEM;

	root = indx_get_root(indx, ni, NULL, &mi);
	if (!root) {
		err = -EINVAL;
		goto out;
	}

	/* Find entry in directory. */
	err = indx_find(indx, ni, root, fname, fname_full_size(fname), sbi,
			&diff, &e, fnd);
	if (err)
		goto out;

	if (!e) {
		err = -EINVAL;
		goto out;
	}

	if (diff) {
		err = -EINVAL;
		goto out;
	}

	e_fname = (struct ATTR_FILE_NAME *)(e + 1);

	if (!memcmp(&e_fname->dup, dup, sizeof(*dup))) {
		/*
		 * Nothing to update in index! Try to avoid this call.
		 */
		goto out;
	}

	memcpy(&e_fname->dup, dup, sizeof(*dup));

	if (fnd->level) {
		/* Directory entry in index. */
		err = indx_write(indx, ni, fnd->nodes[fnd->level - 1], sync);
	} else {
		/* Directory entry in directory MFT record. */
		mi->dirty = true;
		if (sync)
			err = mi_write(mi, 1);
		else
			mark_inode_dirty(&ni->vfs_inode);
	}

out:
	fnd_put(fnd);
	return err;
}