summaryrefslogtreecommitdiffstats
path: root/fs/ubifs/ubifs.h
blob: 702b79258e30026fdfb4c0561d9ebfdbd51a93db (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
/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * Authors: Artem Bityutskiy (Битюцкий Артём)
 *          Adrian Hunter
 */

#ifndef __UBIFS_H__
#define __UBIFS_H__

#include <asm/div64.h>
#include <linux/statfs.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/mtd/ubi.h>
#include <linux/pagemap.h>
#include <linux/backing-dev.h>
#include "ubifs-media.h"

/* Version of this UBIFS implementation */
#define UBIFS_VERSION 1

/* Normal UBIFS messages */
#define ubifs_msg(fmt, ...) \
		printk(KERN_NOTICE "UBIFS: " fmt "\n", ##__VA_ARGS__)
/* UBIFS error messages */
#define ubifs_err(fmt, ...)                                                  \
	printk(KERN_ERR "UBIFS error (pid %d): %s: " fmt "\n", current->pid, \
	       __func__, ##__VA_ARGS__)
/* UBIFS warning messages */
#define ubifs_warn(fmt, ...)                                         \
	printk(KERN_WARNING "UBIFS warning (pid %d): %s: " fmt "\n", \
	       current->pid, __func__, ##__VA_ARGS__)

/* UBIFS file system VFS magic number */
#define UBIFS_SUPER_MAGIC 0x24051905

/* Number of UBIFS blocks per VFS page */
#define UBIFS_BLOCKS_PER_PAGE (PAGE_CACHE_SIZE / UBIFS_BLOCK_SIZE)
#define UBIFS_BLOCKS_PER_PAGE_SHIFT (PAGE_CACHE_SHIFT - UBIFS_BLOCK_SHIFT)

/* "File system end of life" sequence number watermark */
#define SQNUM_WARN_WATERMARK 0xFFFFFFFF00000000ULL
#define SQNUM_WATERMARK      0xFFFFFFFFFF000000ULL

/*
 * Minimum amount of LEBs reserved for the index. At present the index needs at
 * least 2 LEBs: one for the index head and one for in-the-gaps method (which
 * currently does not cater for the index head and so excludes it from
 * consideration).
 */
#define MIN_INDEX_LEBS 2

/* Minimum amount of data UBIFS writes to the flash */
#define MIN_WRITE_SZ (UBIFS_DATA_NODE_SZ + 8)

/*
 * Currently we do not support inode number overlapping and re-using, so this
 * watermark defines dangerous inode number level. This should be fixed later,
 * although it is difficult to exceed current limit. Another option is to use
 * 64-bit inode numbers, but this means more overhead.
 */
#define INUM_WARN_WATERMARK 0xFFF00000
#define INUM_WATERMARK      0xFFFFFF00

/* Largest key size supported in this implementation */
#define CUR_MAX_KEY_LEN UBIFS_SK_LEN

/* Maximum number of entries in each LPT (LEB category) heap */
#define LPT_HEAP_SZ 256

/*
 * Background thread name pattern. The numbers are UBI device and volume
 * numbers.
 */
#define BGT_NAME_PATTERN "ubifs_bgt%d_%d"

/* Write-buffer synchronization timeout interval in seconds */
#define WBUF_TIMEOUT_SOFTLIMIT 3
#define WBUF_TIMEOUT_HARDLIMIT 5

/* Maximum possible inode number (only 32-bit inodes are supported now) */
#define MAX_INUM 0xFFFFFFFF

/* Number of non-data journal heads */
#define NONDATA_JHEADS_CNT 2

/* Shorter names for journal head numbers for internal usage */
#define GCHD   UBIFS_GC_HEAD
#define BASEHD UBIFS_BASE_HEAD
#define DATAHD UBIFS_DATA_HEAD

/* 'No change' value for 'ubifs_change_lp()' */
#define LPROPS_NC 0x80000001

/*
 * There is no notion of truncation key because truncation nodes do not exist
 * in TNC. However, when replaying, it is handy to introduce fake "truncation"
 * keys for truncation nodes because the code becomes simpler. So we define
 * %UBIFS_TRUN_KEY type.
 *
 * But otherwise, out of the journal reply scope, the truncation keys are
 * invalid.
 */
#define UBIFS_TRUN_KEY    UBIFS_KEY_TYPES_CNT
#define UBIFS_INVALID_KEY UBIFS_KEY_TYPES_CNT

/*
 * How much a directory entry/extended attribute entry adds to the parent/host
 * inode.
 */
#define CALC_DENT_SIZE(name_len) ALIGN(UBIFS_DENT_NODE_SZ + (name_len) + 1, 8)

/* How much an extended attribute adds to the host inode */
#define CALC_XATTR_BYTES(data_len) ALIGN(UBIFS_INO_NODE_SZ + (data_len) + 1, 8)

/*
 * Znodes which were not touched for 'OLD_ZNODE_AGE' seconds are considered
 * "old", and znode which were touched last 'YOUNG_ZNODE_AGE' seconds ago are
 * considered "young". This is used by shrinker when selecting znode to trim
 * off.
 */
#define OLD_ZNODE_AGE 20
#define YOUNG_ZNODE_AGE 5

/*
 * Some compressors, like LZO, may end up with more data then the input buffer.
 * So UBIFS always allocates larger output buffer, to be sure the compressor
 * will not corrupt memory in case of worst case compression.
 */
#define WORST_COMPR_FACTOR 2

/*
 * How much memory is needed for a buffer where we comress a data node.
 */
#define COMPRESSED_DATA_NODE_BUF_SZ \
	(UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR)

/* Maximum expected tree height for use by bottom_up_buf */
#define BOTTOM_UP_HEIGHT 64

/* Maximum number of data nodes to bulk-read */
#define UBIFS_MAX_BULK_READ 32

/*
 * Lockdep classes for UBIFS inode @ui_mutex.
 */
enum {
	WB_MUTEX_1 = 0,
	WB_MUTEX_2 = 1,
	WB_MUTEX_3 = 2,
};

/*
 * Znode flags (actually, bit numbers which store the flags).
 *
 * DIRTY_ZNODE: znode is dirty
 * COW_ZNODE: znode is being committed and a new instance of this znode has to
 *            be created before changing this znode
 * OBSOLETE_ZNODE: znode is obsolete, which means it was deleted, but it is
 *                 still in the commit list and the ongoing commit operation
 *                 will commit it, and delete this znode after it is done
 */
enum {
	DIRTY_ZNODE    = 0,
	COW_ZNODE      = 1,
	OBSOLETE_ZNODE = 2,
};

/*
 * Commit states.
 *
 * COMMIT_RESTING: commit is not wanted
 * COMMIT_BACKGROUND: background commit has been requested
 * COMMIT_REQUIRED: commit is required
 * COMMIT_RUNNING_BACKGROUND: background commit is running
 * COMMIT_RUNNING_REQUIRED: commit is running and it is required
 * COMMIT_BROKEN: commit failed
 */
enum {
	COMMIT_RESTING = 0,
	COMMIT_BACKGROUND,
	COMMIT_REQUIRED,
	COMMIT_RUNNING_BACKGROUND,
	COMMIT_RUNNING_REQUIRED,
	COMMIT_BROKEN,
};

/*
 * 'ubifs_scan_a_node()' return values.
 *
 * SCANNED_GARBAGE:  scanned garbage
 * SCANNED_EMPTY_SPACE: scanned empty space
 * SCANNED_A_NODE: scanned a valid node
 * SCANNED_A_CORRUPT_NODE: scanned a corrupted node
 * SCANNED_A_BAD_PAD_NODE: scanned a padding node with invalid pad length
 *
 * Greater than zero means: 'scanned that number of padding bytes'
 */
enum {
	SCANNED_GARBAGE        = 0,
	SCANNED_EMPTY_SPACE    = -1,
	SCANNED_A_NODE         = -2,
	SCANNED_A_CORRUPT_NODE = -3,
	SCANNED_A_BAD_PAD_NODE = -4,
};

/*
 * LPT cnode flag bits.
 *
 * DIRTY_CNODE: cnode is dirty
 * OBSOLETE_CNODE: cnode is being committed and has been copied (or deleted),
 *                 so it can (and must) be freed when the commit is finished
 * COW_CNODE: cnode is being committed and must be copied before writing
 */
enum {
	DIRTY_CNODE    = 0,
	OBSOLETE_CNODE = 1,
	COW_CNODE      = 2,
};

/*
 * Dirty flag bits (lpt_drty_flgs) for LPT special nodes.
 *
 * LTAB_DIRTY: ltab node is dirty
 * LSAVE_DIRTY: lsave node is dirty
 */
enum {
	LTAB_DIRTY  = 1,
	LSAVE_DIRTY = 2,
};

/*
 * Return codes used by the garbage collector.
 * @LEB_FREED: the logical eraseblock was freed and is ready to use
 * @LEB_FREED_IDX: indexing LEB was freed and can be used only after the commit
 * @LEB_RETAINED: the logical eraseblock was freed and retained for GC purposes
 */
enum {
	LEB_FREED,
	LEB_FREED_IDX,
	LEB_RETAINED,
};

/**
 * struct ubifs_old_idx - index node obsoleted since last commit start.
 * @rb: rb-tree node
 * @lnum: LEB number of obsoleted index node
 * @offs: offset of obsoleted index node
 */
struct ubifs_old_idx {
	struct rb_node rb;
	int lnum;
	int offs;
};

/* The below union makes it easier to deal with keys */
union ubifs_key {
	uint8_t u8[CUR_MAX_KEY_LEN];
	uint32_t u32[CUR_MAX_KEY_LEN/4];
	uint64_t u64[CUR_MAX_KEY_LEN/8];
	__le32 j32[CUR_MAX_KEY_LEN/4];
};

/**
 * struct ubifs_scan_node - UBIFS scanned node information.
 * @list: list of scanned nodes
 * @key: key of node scanned (if it has one)
 * @sqnum: sequence number
 * @type: type of node scanned
 * @offs: offset with LEB of node scanned
 * @len: length of node scanned
 * @node: raw node
 */
struct ubifs_scan_node {
	struct list_head list;
	union ubifs_key key;
	unsigned long long sqnum;
	int type;
	int offs;
	int len;
	void *node;
};

/**
 * struct ubifs_scan_leb - UBIFS scanned LEB information.
 * @lnum: logical eraseblock number
 * @nodes_cnt: number of nodes scanned
 * @nodes: list of struct ubifs_scan_node
 * @endpt: end point (and therefore the start of empty space)
 * @ecc: read returned -EBADMSG
 * @buf: buffer containing entire LEB scanned
 */
struct ubifs_scan_leb {
	int lnum;
	int nodes_cnt;
	struct list_head nodes;
	int endpt;
	int ecc;
	void *buf;
};

/**
 * struct ubifs_gced_idx_leb - garbage-collected indexing LEB.
 * @list: list
 * @lnum: LEB number
 * @unmap: OK to unmap this LEB
 *
 * This data structure is used to temporary store garbage-collected indexing
 * LEBs - they are not released immediately, but only after the next commit.
 * This is needed to guarantee recoverability.
 */
struct ubifs_gced_idx_leb {
	struct list_head list;
	int lnum;
	int unmap;
};

/**
 * struct ubifs_inode - UBIFS in-memory inode description.
 * @vfs_inode: VFS inode description object
 * @creat_sqnum: sequence number at time of creation
 * @del_cmtno: commit number corresponding to the time the inode was deleted,
 *             protected by @c->commit_sem;
 * @xattr_size: summarized size of all extended attributes in bytes
 * @xattr_cnt: count of extended attributes this inode has
 * @xattr_names: sum of lengths of all extended attribute names belonging to
 *               this inode
 * @dirty: non-zero if the inode is dirty
 * @xattr: non-zero if this is an extended attribute inode
 * @bulk_read: non-zero if bulk-read should be used
 * @ui_mutex: serializes inode write-back with the rest of VFS operations,
 *            serializes "clean <-> dirty" state changes, serializes bulk-read,
 *            protects @dirty, @bulk_read, @ui_size, and @xattr_size
 * @ui_lock: protects @synced_i_size
 * @synced_i_size: synchronized size of inode, i.e. the value of inode size
 *                 currently stored on the flash; used only for regular file
 *                 inodes
 * @ui_size: inode size used by UBIFS when writing to flash
 * @flags: inode flags (@UBIFS_COMPR_FL, etc)
 * @compr_type: default compression type used for this inode
 * @last_page_read: page number of last page read (for bulk read)
 * @read_in_a_row: number of consecutive pages read in a row (for bulk read)
 * @data_len: length of the data attached to the inode
 * @data: inode's data
 *
 * @ui_mutex exists for two main reasons. At first it prevents inodes from
 * being written back while UBIFS changing them, being in the middle of an VFS
 * operation. This way UBIFS makes sure the inode fields are consistent. For
 * example, in 'ubifs_rename()' we change 3 inodes simultaneously, and
 * write-back must not write any of them before we have finished.
 *
 * The second reason is budgeting - UBIFS has to budget all operations. If an
 * operation is going to mark an inode dirty, it has to allocate budget for
 * this. It cannot just mark it dirty because there is no guarantee there will
 * be enough flash space to write the inode back later. This means UBIFS has
 * to have full control over inode "clean <-> dirty" transitions (and pages
 * actually). But unfortunately, VFS marks inodes dirty in many places, and it
 * does not ask the file-system if it is allowed to do so (there is a notifier,
 * but it is not enough), i.e., there is no mechanism to synchronize with this.
 * So UBIFS has its own inode dirty flag and its own mutex to serialize
 * "clean <-> dirty" transitions.
 *
 * The @synced_i_size field is used to make sure we never write pages which are
 * beyond last synchronized inode size. See 'ubifs_writepage()' for more
 * information.
 *
 * The @ui_size is a "shadow" variable for @inode->i_size and UBIFS uses
 * @ui_size instead of @inode->i_size. The reason for this is that UBIFS cannot
 * make sure @inode->i_size is always changed under @ui_mutex, because it
 * cannot call 'truncate_setsize()' with @ui_mutex locked, because it would
 * deadlock with 'ubifs_writepage()' (see file.c). All the other inode fields
 * are changed under @ui_mutex, so they do not need "shadow" fields. Note, one
 * could consider to rework locking and base it on "shadow" fields.
 */
struct ubifs_inode {
	struct inode vfs_inode;
	unsigned long long creat_sqnum;
	unsigned long long del_cmtno;
	unsigned int xattr_size;
	unsigned int xattr_cnt;
	unsigned int xattr_names;
	unsigned int dirty:1;
	unsigned int xattr:1;
	unsigned int bulk_read:1;
	unsigned int compr_type:2;
	struct mutex ui_mutex;
	spinlock_t ui_lock;
	loff_t synced_i_size;
	loff_t ui_size;
	int flags;
	pgoff_t last_page_read;
	pgoff_t read_in_a_row;
	int data_len;
	void *data;
};

/**
 * struct ubifs_unclean_leb - records a LEB recovered under read-only mode.
 * @list: list
 * @lnum: LEB number of recovered LEB
 * @endpt: offset where recovery ended
 *
 * This structure records a LEB identified during recovery that needs to be
 * cleaned but was not because UBIFS was mounted read-only. The information
 * is used to clean the LEB when remounting to read-write mode.
 */
struct ubifs_unclean_leb {
	struct list_head list;
	int lnum;
	int endpt;
};

/*
 * LEB properties flags.
 *
 * LPROPS_UNCAT: not categorized
 * LPROPS_DIRTY: dirty > free, dirty >= @c->dead_wm, not index
 * LPROPS_DIRTY_IDX: dirty + free > @c->min_idx_node_sze and index
 * LPROPS_FREE: free > 0, dirty < @c->dead_wm, not empty, not index
 * LPROPS_HEAP_CNT: number of heaps used for storing categorized LEBs
 * LPROPS_EMPTY: LEB is empty, not taken
 * LPROPS_FREEABLE: free + dirty == leb_size, not index, not taken
 * LPROPS_FRDI_IDX: free + dirty == leb_size and index, may be taken
 * LPROPS_CAT_MASK: mask for the LEB categories above
 * LPROPS_TAKEN: LEB was taken (this flag is not saved on the media)
 * LPROPS_INDEX: LEB contains indexing nodes (this flag also exists on flash)
 */
enum {
	LPROPS_UNCAT     =  0,
	LPROPS_DIRTY     =  1,
	LPROPS_DIRTY_IDX =  2,
	LPROPS_FREE      =  3,
	LPROPS_HEAP_CNT  =  3,
	LPROPS_EMPTY     =  4,
	LPROPS_FREEABLE  =  5,
	LPROPS_FRDI_IDX  =  6,
	LPROPS_CAT_MASK  = 15,
	LPROPS_TAKEN     = 16,
	LPROPS_INDEX     = 32,
};

/**
 * struct ubifs_lprops - logical eraseblock properties.
 * @free: amount of free space in bytes
 * @dirty: amount of dirty space in bytes
 * @flags: LEB properties flags (see above)
 * @lnum: LEB number
 * @list: list of same-category lprops (for LPROPS_EMPTY and LPROPS_FREEABLE)
 * @hpos: heap position in heap of same-category lprops (other categories)
 */
struct ubifs_lprops {
	int free;
	int dirty;
	int flags;
	int lnum;
	union {
		struct list_head list;
		int hpos;
	};
};

/**
 * struct ubifs_lpt_lprops - LPT logical eraseblock properties.
 * @free: amount of free space in bytes
 * @dirty: amount of dirty space in bytes
 * @tgc: trivial GC flag (1 => unmap after commit end)
 * @cmt: commit flag (1 => reserved for commit)
 */
struct ubifs_lpt_lprops {
	int free;
	int dirty;
	unsigned tgc:1;
	unsigned cmt:1;
};

/**
 * struct ubifs_lp_stats - statistics of eraseblocks in the main area.
 * @empty_lebs: number of empty LEBs
 * @taken_empty_lebs: number of taken LEBs
 * @idx_lebs: number of indexing LEBs
 * @total_free: total free space in bytes (includes all LEBs)
 * @total_dirty: total dirty space in bytes (includes all LEBs)
 * @total_used: total used space in bytes (does not include index LEBs)
 * @total_dead: total dead space in bytes (does not include index LEBs)
 * @total_dark: total dark space in bytes (does not include index LEBs)
 *
 * The @taken_empty_lebs field counts the LEBs that are in the transient state
 * of having been "taken" for use but not yet written to. @taken_empty_lebs is
 * needed to account correctly for @gc_lnum, otherwise @empty_lebs could be
 * used by itself (in which case 'unused_lebs' would be a better name). In the
 * case of @gc_lnum, it is "taken" at mount time or whenever a LEB is retained
 * by GC, but unlike other empty LEBs that are "taken", it may not be written
 * straight away (i.e. before the next commit start or unmount), so either
 * @gc_lnum must be specially accounted for, or the current approach followed
 * i.e. count it under @taken_empty_lebs.
 *
 * @empty_lebs includes @taken_empty_lebs.
 *
 * @total_used, @total_dead and @total_dark fields do not account indexing
 * LEBs.
 */
struct ubifs_lp_stats {
	int empty_lebs;
	int taken_empty_lebs;
	int idx_lebs;
	long long total_free;
	long long total_dirty;
	long long total_used;
	long long total_dead;
	long long total_dark;
};

struct ubifs_nnode;

/**
 * struct ubifs_cnode - LEB Properties Tree common node.
 * @parent: parent nnode
 * @cnext: next cnode to commit
 * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
 * @iip: index in parent
 * @level: level in the tree (zero for pnodes, greater than zero for nnodes)
 * @num: node number
 */
struct ubifs_cnode {
	struct ubifs_nnode *parent;
	struct ubifs_cnode *cnext;
	unsigned long flags;
	int iip;
	int level;
	int num;
};

/**
 * struct ubifs_pnode - LEB Properties Tree leaf node.
 * @parent: parent nnode
 * @cnext: next cnode to commit
 * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
 * @iip: index in parent
 * @level: level in the tree (always zero for pnodes)
 * @num: node number
 * @lprops: LEB properties array
 */
struct ubifs_pnode {
	struct ubifs_nnode *parent;
	struct ubifs_cnode *cnext;
	unsigned long flags;
	int iip;
	int level;
	int num;
	struct ubifs_lprops lprops[UBIFS_LPT_FANOUT];
};

/**
 * struct ubifs_nbranch - LEB Properties Tree internal node branch.
 * @lnum: LEB number of child
 * @offs: offset of child
 * @nnode: nnode child
 * @pnode: pnode child
 * @cnode: cnode child
 */
struct ubifs_nbranch {
	int lnum;
	int offs;
	union {
		struct ubifs_nnode *nnode;
		struct ubifs_pnode *pnode;
		struct ubifs_cnode *cnode;
	};
};

/**
 * struct ubifs_nnode - LEB Properties Tree internal node.
 * @parent: parent nnode
 * @cnext: next cnode to commit
 * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
 * @iip: index in parent
 * @level: level in the tree (always greater than zero for nnodes)
 * @num: node number
 * @nbranch: branches to child nodes
 */
struct ubifs_nnode {
	struct ubifs_nnode *parent;
	struct ubifs_cnode *cnext;
	unsigned long flags;
	int iip;
	int level;
	int num;
	struct ubifs_nbranch nbranch[UBIFS_LPT_FANOUT];
};

/**
 * struct ubifs_lpt_heap - heap of categorized lprops.
 * @arr: heap array
 * @cnt: number in heap
 * @max_cnt: maximum number allowed in heap
 *
 * There are %LPROPS_HEAP_CNT heaps.
 */
struct ubifs_lpt_heap {
	struct ubifs_lprops **arr;
	int cnt;
	int max_cnt;
};

/*
 * Return codes for LPT scan callback function.
 *
 * LPT_SCAN_CONTINUE: continue scanning
 * LPT_SCAN_ADD: add the LEB properties scanned to the tree in memory
 * LPT_SCAN_STOP: stop scanning
 */
enum {
	LPT_SCAN_CONTINUE = 0,
	LPT_SCAN_ADD = 1,
	LPT_SCAN_STOP = 2,
};

struct ubifs_info;

/* Callback used by the 'ubifs_lpt_scan_nolock()' function */
typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c,
				       const struct ubifs_lprops *lprops,
				       int in_tree, void *data);

/**
 * struct ubifs_wbuf - UBIFS write-buffer.
 * @c: UBIFS file-system description object
 * @buf: write-buffer (of min. flash I/O unit size)
 * @lnum: logical eraseblock number the write-buffer points to
 * @offs: write-buffer offset in this logical eraseblock
 * @avail: number of bytes available in the write-buffer
 * @used:  number of used bytes in the write-buffer
 * @size: write-buffer size (in [@c->min_io_size, @c->max_write_size] range)
 * @dtype: type of data stored in this LEB (%UBI_LONGTERM, %UBI_SHORTTERM,
 * %UBI_UNKNOWN)
 * @jhead: journal head the mutex belongs to (note, needed only to shut lockdep
 *         up by 'mutex_lock_nested()).
 * @sync_callback: write-buffer synchronization callback
 * @io_mutex: serializes write-buffer I/O
 * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes
 *        fields
 * @softlimit: soft write-buffer timeout interval
 * @delta: hard and soft timeouts delta (the timer expire inteval is @softlimit
 *         and @softlimit + @delta)
 * @timer: write-buffer timer
 * @no_timer: non-zero if this write-buffer does not have a timer
 * @need_sync: non-zero if the timer expired and the wbuf needs sync'ing
 * @next_ino: points to the next position of the following inode number
 * @inodes: stores the inode numbers of the nodes which are in wbuf
 *
 * The write-buffer synchronization callback is called when the write-buffer is
 * synchronized in order to notify how much space was wasted due to
 * write-buffer padding and how much free space is left in the LEB.
 *
 * Note: the fields @buf, @lnum, @offs, @avail and @used can be read under
 * spin-lock or mutex because they are written under both mutex and spin-lock.
 * @buf is appended to under mutex but overwritten under both mutex and
 * spin-lock. Thus the data between @buf and @buf + @used can be read under
 * spinlock.
 */
struct ubifs_wbuf {
	struct ubifs_info *c;
	void *buf;
	int lnum;
	int offs;
	int avail;
	int used;
	int size;
	int dtype;
	int jhead;
	int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad);
	struct mutex io_mutex;
	spinlock_t lock;
	ktime_t softlimit;
	unsigned long long delta;
	struct hrtimer timer;
	unsigned int no_timer:1;
	unsigned int need_sync:1;
	int next_ino;
	ino_t *inodes;
};

/**
 * struct ubifs_bud - bud logical eraseblock.
 * @lnum: logical eraseblock number
 * @start: where the (uncommitted) bud data starts
 * @jhead: journal head number this bud belongs to
 * @list: link in the list buds belonging to the same journal head
 * @rb: link in the tree of all buds
 */
struct ubifs_bud {
	int lnum;
	int start;
	int jhead;
	struct list_head list;
	struct rb_node rb;
};

/**
 * struct ubifs_jhead - journal head.
 * @wbuf: head's write-buffer
 * @buds_list: list of bud LEBs belonging to this journal head
 * @grouped: non-zero if UBIFS groups nodes when writing to this journal head
 *
 * Note, the @buds list is protected by the @c->buds_lock.
 */
struct ubifs_jhead {
	struct ubifs_wbuf wbuf;
	struct list_head buds_list;
	unsigned int grouped:1;
};

/**
 * struct ubifs_zbranch - key/coordinate/length branch stored in znodes.
 * @key: key
 * @znode: znode address in memory
 * @lnum: LEB number of the target node (indexing node or data node)
 * @offs: target node offset within @lnum
 * @len: target node length
 */
struct ubifs_zbranch {
	union ubifs_key key;
	union {
		struct ubifs_znode *znode;
		void *leaf;
	};
	int lnum;
	int offs;
	int len;
};

/**
 * struct ubifs_znode - in-memory representation of an indexing node.
 * @parent: parent znode or NULL if it is the root
 * @cnext: next znode to commit
 * @flags: znode flags (%DIRTY_ZNODE, %COW_ZNODE or %OBSOLETE_ZNODE)
 * @time: last access time (seconds)
 * @level: level of the entry in the TNC tree
 * @child_cnt: count of child znodes
 * @iip: index in parent's zbranch array
 * @alt: lower bound of key range has altered i.e. child inserted at slot 0
 * @lnum: LEB number of the corresponding indexing node
 * @offs: offset of the corresponding indexing node
 * @len: length  of the corresponding indexing node
 * @zbranch: array of znode branches (@c->fanout elements)
 */
struct ubifs_znode {
	struct ubifs_znode *parent;
	struct ubifs_znode *cnext;
	unsigned long flags;
	unsigned long time;
	int level;
	int child_cnt;
	int iip;
	int alt;
#ifdef CONFIG_UBIFS_FS_DEBUG
	int lnum, offs, len;
#endif
	struct ubifs_zbranch zbranch[];
};

/**
 * struct bu_info - bulk-read information.
 * @key: first data node key
 * @zbranch: zbranches of data nodes to bulk read
 * @buf: buffer to read into
 * @buf_len: buffer length
 * @gc_seq: GC sequence number to detect races with GC
 * @cnt: number of data nodes for bulk read
 * @blk_cnt: number of data blocks including holes
 * @oef: end of file reached
 */
struct bu_info {
	union ubifs_key key;
	struct ubifs_zbranch zbranch[UBIFS_MAX_BULK_READ];
	void *buf;
	int buf_len;
	int gc_seq;
	int cnt;
	int blk_cnt;
	int eof;
};

/**
 * struct ubifs_node_range - node length range description data structure.
 * @len: fixed node length
 * @min_len: minimum possible node length
 * @max_len: maximum possible node length
 *
 * If @max_len is %0, the node has fixed length @len.
 */
struct ubifs_node_range {
	union {
		int len;
		int min_len;
	};
	int max_len;
};

/**
 * struct ubifs_compressor - UBIFS compressor description structure.
 * @compr_type: compressor type (%UBIFS_COMPR_LZO, etc)
 * @cc: cryptoapi compressor handle
 * @comp_mutex: mutex used during compression
 * @decomp_mutex: mutex used during decompression
 * @name: compressor name
 * @capi_name: cryptoapi compressor name
 */
struct ubifs_compressor {
	int compr_type;
	struct crypto_comp *cc;
	struct mutex *comp_mutex;
	struct mutex *decomp_mutex;
	const char *name;
	const char *capi_name;
};

/**
 * struct ubifs_budget_req - budget requirements of an operation.
 *
 * @fast: non-zero if the budgeting should try to acquire budget quickly and
 *        should not try to call write-back
 * @recalculate: non-zero if @idx_growth, @data_growth, and @dd_growth fields
 *               have to be re-calculated
 * @new_page: non-zero if the operation adds a new page
 * @dirtied_page: non-zero if the operation makes a page dirty
 * @new_dent: non-zero if the operation adds a new directory entry
 * @mod_dent: non-zero if the operation removes or modifies an existing
 *            directory entry
 * @new_ino: non-zero if the operation adds a new inode
 * @new_ino_d: now much data newly created inode contains
 * @dirtied_ino: how many inodes the operation makes dirty
 * @dirtied_ino_d: now much data dirtied inode contains
 * @idx_growth: how much the index will supposedly grow
 * @data_growth: how much new data the operation will supposedly add
 * @dd_growth: how much data that makes other data dirty the operation will
 *             supposedly add
 *
 * @idx_growth, @data_growth and @dd_growth are not used in budget request. The
 * budgeting subsystem caches index and data growth values there to avoid
 * re-calculating them when the budget is released. However, if @idx_growth is
 * %-1, it is calculated by the release function using other fields.
 *
 * An inode may contain 4KiB of data at max., thus the widths of @new_ino_d
 * is 13 bits, and @dirtied_ino_d - 15, because up to 4 inodes may be made
 * dirty by the re-name operation.
 *
 * Note, UBIFS aligns node lengths to 8-bytes boundary, so the requester has to
 * make sure the amount of inode data which contribute to @new_ino_d and
 * @dirtied_ino_d fields are aligned.
 */
struct ubifs_budget_req {
	unsigned int fast:1;
	unsigned int recalculate:1;
#ifndef UBIFS_DEBUG
	unsigned int new_page:1;
	unsigned int dirtied_page:1;
	unsigned int new_dent:1;
	unsigned int mod_dent:1;
	unsigned int new_ino:1;
	unsigned int new_ino_d:13;
	unsigned int dirtied_ino:4;
	unsigned int dirtied_ino_d:15;
#else
	/* Not bit-fields to check for overflows */
	unsigned int new_page;
	unsigned int dirtied_page;
	unsigned int new_dent;
	unsigned int mod_dent;
	unsigned int new_ino;
	unsigned int new_ino_d;
	unsigned int dirtied_ino;
	unsigned int dirtied_ino_d;
#endif
	int idx_growth;
	int data_growth;
	int dd_growth;
};

/**
 * struct ubifs_orphan - stores the inode number of an orphan.
 * @rb: rb-tree node of rb-tree of orphans sorted by inode number
 * @list: list head of list of orphans in order added
 * @new_list: list head of list of orphans added since the last commit
 * @cnext: next orphan to commit
 * @dnext: next orphan to delete
 * @inum: inode number
 * @new: %1 => added since the last commit, otherwise %0
 */
struct ubifs_orphan {
	struct rb_node rb;
	struct list_head list;
	struct list_head new_list;
	struct ubifs_orphan *cnext;
	struct ubifs_orphan *dnext;
	ino_t inum;
	int new;
};

/**
 * struct ubifs_mount_opts - UBIFS-specific mount options information.
 * @unmount_mode: selected unmount mode (%0 default, %1 normal, %2 fast)
 * @bulk_read: enable/disable bulk-reads (%0 default, %1 disabe, %2 enable)
 * @chk_data_crc: enable/disable CRC data checking when reading data nodes
 *                (%0 default, %1 disabe, %2 enable)
 * @override_compr: override default compressor (%0 - do not override and use
 *                  superblock compressor, %1 - override and use compressor
 *                  specified in @compr_type)
 * @compr_type: compressor type to override the superblock compressor with
 *              (%UBIFS_COMPR_NONE, etc)
 */
struct ubifs_mount_opts {
	unsigned int unmount_mode:2;
	unsigned int bulk_read:2;
	unsigned int chk_data_crc:2;
	unsigned int override_compr:1;
	unsigned int compr_type:2;
};

/**
 * struct ubifs_budg_info - UBIFS budgeting information.
 * @idx_growth: amount of bytes budgeted for index growth
 * @data_growth: amount of bytes budgeted for cached data
 * @dd_growth: amount of bytes budgeted for cached data that will make
 *             other data dirty
 * @uncommitted_idx: amount of bytes were budgeted for growth of the index, but
 *                   which still have to be taken into account because the index
 *                   has not been committed so far
 * @old_idx_sz: size of index on flash
 * @min_idx_lebs: minimum number of LEBs required for the index
 * @nospace: non-zero if the file-system does not have flash space (used as
 *           optimization)
 * @nospace_rp: the same as @nospace, but additionally means that even reserved
 *              pool is full
 * @page_budget: budget for a page (constant, nenver changed after mount)
 * @inode_budget: budget for an inode (constant, nenver changed after mount)
 * @dent_budget: budget for a directory entry (constant, nenver changed after
 *               mount)
 */
struct ubifs_budg_info {
	long long idx_growth;
	long long data_growth;
	long long dd_growth;
	long long uncommitted_idx;
	unsigned long long old_idx_sz;
	int min_idx_lebs;
	unsigned int nospace:1;
	unsigned int nospace_rp:1;
	int page_budget;
	int inode_budget;
	int dent_budget;
};

struct ubifs_debug_info;

/**
 * struct ubifs_info - UBIFS file-system description data structure
 * (per-superblock).
 * @vfs_sb: VFS @struct super_block object
 * @bdi: backing device info object to make VFS happy and disable read-ahead
 *
 * @highest_inum: highest used inode number
 * @max_sqnum: current global sequence number
 * @cmt_no: commit number of the last successfully completed commit, protected
 *          by @commit_sem
 * @cnt_lock: protects @highest_inum and @max_sqnum counters
 * @fmt_version: UBIFS on-flash format version
 * @ro_compat_version: R/O compatibility version
 * @uuid: UUID from super block
 *
 * @lhead_lnum: log head logical eraseblock number
 * @lhead_offs: log head offset
 * @ltail_lnum: log tail logical eraseblock number (offset is always 0)
 * @log_mutex: protects the log, @lhead_lnum, @lhead_offs, @ltail_lnum, and
 *             @bud_bytes
 * @min_log_bytes: minimum required number of bytes in the log
 * @cmt_bud_bytes: used during commit to temporarily amount of bytes in
 *                 committed buds
 *
 * @buds: tree of all buds indexed by bud LEB number
 * @bud_bytes: how many bytes of flash is used by buds
 * @buds_lock: protects the @buds tree, @bud_bytes, and per-journal head bud
 *             lists
 * @jhead_cnt: count of journal heads
 * @jheads: journal heads (head zero is base head)
 * @max_bud_bytes: maximum number of bytes allowed in buds
 * @bg_bud_bytes: number of bud bytes when background commit is initiated
 * @old_buds: buds to be released after commit ends
 * @max_bud_cnt: maximum number of buds
 *
 * @commit_sem: synchronizes committer with other processes
 * @cmt_state: commit state
 * @cs_lock: commit state lock
 * @cmt_wq: wait queue to sleep on if the log is full and a commit is running
 *
 * @big_lpt: flag that LPT is too big to write whole during commit
 * @space_fixup: flag indicating that free space in LEBs needs to be cleaned up
 * @no_chk_data_crc: do not check CRCs when reading data nodes (except during
 *                   recovery)
 * @bulk_read: enable bulk-reads
 * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
 * @rw_incompat: the media is not R/W compatible
 *
 * @tnc_mutex: protects the Tree Node Cache (TNC), @zroot, @cnext, @enext, and
 *             @calc_idx_sz
 * @zroot: zbranch which points to the root index node and znode
 * @cnext: next znode to commit
 * @enext: next znode to commit to empty space
 * @gap_lebs: array of LEBs used by the in-gaps commit method
 * @cbuf: commit buffer
 * @ileb_buf: buffer for commit in-the-gaps method
 * @ileb_len: length of data in ileb_buf
 * @ihead_lnum: LEB number of index head
 * @ihead_offs: offset of index head
 * @ilebs: pre-allocated index LEBs
 * @ileb_cnt: number of pre-allocated index LEBs
 * @ileb_nxt: next pre-allocated index LEBs
 * @old_idx: tree of index nodes obsoleted since the last commit start
 * @bottom_up_buf: a buffer which is used by 'dirty_cow_bottom_up()' in tnc.c
 *
 * @mst_node: master node
 * @mst_offs: offset of valid master node
 * @mst_mutex: protects the master node area, @mst_node, and @mst_offs
 *
 * @max_bu_buf_len: maximum bulk-read buffer length
 * @bu_mutex: protects the pre-allocated bulk-read buffer and @c->bu
 * @bu: pre-allocated bulk-read information
 *
 * @write_reserve_mutex: protects @write_reserve_buf
 * @write_reserve_buf: on the write path we allocate memory, which might
 *                     sometimes be unavailable, in which case we use this
 *                     write reserve buffer
 *
 * @log_lebs: number of logical eraseblocks in the log
 * @log_bytes: log size in bytes
 * @log_last: last LEB of the log
 * @lpt_lebs: number of LEBs used for lprops table
 * @lpt_first: first LEB of the lprops table area
 * @lpt_last: last LEB of the lprops table area
 * @orph_lebs: number of LEBs used for the orphan area
 * @orph_first: first LEB of the orphan area
 * @orph_last: last LEB of the orphan area
 * @main_lebs: count of LEBs in the main area
 * @main_first: first LEB of the main area
 * @main_bytes: main area size in bytes
 *
 * @key_hash_type: type of the key hash
 * @key_hash: direntry key hash function
 * @key_fmt: key format
 * @key_len: key length
 * @fanout: fanout of the index tree (number of links per indexing node)
 *
 * @min_io_size: minimal input/output unit size
 * @min_io_shift: number of bits in @min_io_size minus one
 * @max_write_size: maximum amount of bytes the underlying flash can write at a
 *                  time (MTD write buffer size)
 * @max_write_shift: number of bits in @max_write_size minus one
 * @leb_size: logical eraseblock size in bytes
 * @leb_start: starting offset of logical eraseblocks within physical
 *             eraseblocks
 * @half_leb_size: half LEB size
 * @idx_leb_size: how many bytes of an LEB are effectively available when it is
 *                used to store indexing nodes (@leb_size - @max_idx_node_sz)
 * @leb_cnt: count of logical eraseblocks
 * @max_leb_cnt: maximum count of logical eraseblocks
 * @old_leb_cnt: count of logical eraseblocks before re-size
 * @ro_media: the underlying UBI volume is read-only
 * @ro_mount: the file-system was mounted as read-only
 * @ro_error: UBIFS switched to R/O mode because an error happened
 *
 * @dirty_pg_cnt: number of dirty pages (not used)
 * @dirty_zn_cnt: number of dirty znodes
 * @clean_zn_cnt: number of clean znodes
 *
 * @space_lock: protects @bi and @lst
 * @lst: lprops statistics
 * @bi: budgeting information
 * @calc_idx_sz: temporary variable which is used to calculate new index size
 *               (contains accurate new index size at end of TNC commit start)
 *
 * @ref_node_alsz: size of the LEB reference node aligned to the min. flash
 *                 I/O unit
 * @mst_node_alsz: master node aligned size
 * @min_idx_node_sz: minimum indexing node aligned on 8-bytes boundary
 * @max_idx_node_sz: maximum indexing node aligned on 8-bytes boundary
 * @max_inode_sz: maximum possible inode size in bytes
 * @max_znode_sz: size of znode in bytes
 *
 * @leb_overhead: how many bytes are wasted in an LEB when it is filled with
 *                data nodes of maximum size - used in free space reporting
 * @dead_wm: LEB dead space watermark
 * @dark_wm: LEB dark space watermark
 * @block_cnt: count of 4KiB blocks on the FS
 *
 * @ranges: UBIFS node length ranges
 * @ubi: UBI volume descriptor
 * @di: UBI device information
 * @vi: UBI volume information
 *
 * @orph_tree: rb-tree of orphan inode numbers
 * @orph_list: list of orphan inode numbers in order added
 * @orph_new: list of orphan inode numbers added since last commit
 * @orph_cnext: next orphan to commit
 * @orph_dnext: next orphan to delete
 * @orphan_lock: lock for orph_tree and orph_new
 * @orph_buf: buffer for orphan nodes
 * @new_orphans: number of orphans since last commit
 * @cmt_orphans: number of orphans being committed
 * @tot_orphans: number of orphans in the rb_tree
 * @max_orphans: maximum number of orphans allowed
 * @ohead_lnum: orphan head LEB number
 * @ohead_offs: orphan head offset
 * @no_orphs: non-zero if there are no orphans
 *
 * @bgt: UBIFS background thread
 * @bgt_name: background thread name
 * @need_bgt: if background thread should run
 * @need_wbuf_sync: if write-buffers have to be synchronized
 *
 * @gc_lnum: LEB number used for garbage collection
 * @sbuf: a buffer of LEB size used by GC and replay for scanning
 * @idx_gc: list of index LEBs that have been garbage collected
 * @idx_gc_cnt: number of elements on the idx_gc list
 * @gc_seq: incremented for every non-index LEB garbage collected
 * @gced_lnum: last non-index LEB that was garbage collected
 *
 * @infos_list: links all 'ubifs_info' objects
 * @umount_mutex: serializes shrinker and un-mount
 * @shrinker_run_no: shrinker run number
 *
 * @space_bits: number of bits needed to record free or dirty space
 * @lpt_lnum_bits: number of bits needed to record a LEB number in the LPT
 * @lpt_offs_bits: number of bits needed to record an offset in the LPT
 * @lpt_spc_bits: number of bits needed to space in the LPT
 * @pcnt_bits: number of bits needed to record pnode or nnode number
 * @lnum_bits: number of bits needed to record LEB number
 * @nnode_sz: size of on-flash nnode
 * @pnode_sz: size of on-flash pnode
 * @ltab_sz: size of on-flash LPT lprops table
 * @lsave_sz: size of on-flash LPT save table
 * @pnode_cnt: number of pnodes
 * @nnode_cnt: number of nnodes
 * @lpt_hght: height of the LPT
 * @pnodes_have: number of pnodes in memory
 *
 * @lp_mutex: protects lprops table and all the other lprops-related fields
 * @lpt_lnum: LEB number of the root nnode of the LPT
 * @lpt_offs: offset of the root nnode of the LPT
 * @nhead_lnum: LEB number of LPT head
 * @nhead_offs: offset of LPT head
 * @lpt_drty_flgs: dirty flags for LPT special nodes e.g. ltab
 * @dirty_nn_cnt: number of dirty nnodes
 * @dirty_pn_cnt: number of dirty pnodes
 * @check_lpt_free: flag that indicates LPT GC may be needed
 * @lpt_sz: LPT size
 * @lpt_nod_buf: buffer for an on-flash nnode or pnode
 * @lpt_buf: buffer of LEB size used by LPT
 * @nroot: address in memory of the root nnode of the LPT
 * @lpt_cnext: next LPT node to commit
 * @lpt_heap: array of heaps of categorized lprops
 * @dirty_idx: a (reverse sorted) copy of the LPROPS_DIRTY_IDX heap as at
 *             previous commit start
 * @uncat_list: list of un-categorized LEBs
 * @empty_list: list of empty LEBs
 * @freeable_list: list of freeable non-index LEBs (free + dirty == @leb_size)
 * @frdi_idx_list: list of freeable index LEBs (free + dirty == @leb_size)
 * @freeable_cnt: number of freeable LEBs in @freeable_list
 *
 * @ltab_lnum: LEB number of LPT's own lprops table
 * @ltab_offs: offset of LPT's own lprops table
 * @ltab: LPT's own lprops table
 * @ltab_cmt: LPT's own lprops table (commit copy)
 * @lsave_cnt: number of LEB numbers in LPT's save table
 * @lsave_lnum: LEB number of LPT's save table
 * @lsave_offs: offset of LPT's save table
 * @lsave: LPT's save table
 * @lscan_lnum: LEB number of last LPT scan
 *
 * @rp_size: size of the reserved pool in bytes
 * @report_rp_size: size of the reserved pool reported to user-space
 * @rp_uid: reserved pool user ID
 * @rp_gid: reserved pool group ID
 *
 * @empty: %1 if the UBI device is empty
 * @need_recovery: %1 if the file-system needs recovery
 * @replaying: %1 during journal replay
 * @mounting: %1 while mounting
 * @remounting_rw: %1 while re-mounting from R/O mode to R/W mode
 * @replay_list: temporary list used during journal replay
 * @replay_buds: list of buds to replay
 * @cs_sqnum: sequence number of first node in the log (commit start node)
 * @replay_sqnum: sequence number of node currently being replayed
 * @unclean_leb_list: LEBs to recover when re-mounting R/O mounted FS to R/W
 *                    mode
 * @rcvrd_mst_node: recovered master node to write when re-mounting R/O mounted
 *                  FS to R/W mode
 * @size_tree: inode size information for recovery
 * @mount_opts: UBIFS-specific mount options
 *
 * @dbg: debugging-related information
 */
struct ubifs_info {
	struct super_block *vfs_sb;
	struct backing_dev_info bdi;

	ino_t highest_inum;
	unsigned long long max_sqnum;
	unsigned long long cmt_no;
	spinlock_t cnt_lock;
	int fmt_version;
	int ro_compat_version;
	unsigned char uuid[16];

	int lhead_lnum;
	int lhead_offs;
	int ltail_lnum;
	struct mutex log_mutex;
	int min_log_bytes;
	long long cmt_bud_bytes;

	struct rb_root buds;
	long long bud_bytes;
	spinlock_t buds_lock;
	int jhead_cnt;
	struct ubifs_jhead *jheads;
	long long max_bud_bytes;
	long long bg_bud_bytes;
	struct list_head old_buds;
	int max_bud_cnt;

	struct rw_semaphore commit_sem;
	int cmt_state;
	spinlock_t cs_lock;
	wait_queue_head_t cmt_wq;

	unsigned int big_lpt:1;
	unsigned int space_fixup:1;
	unsigned int no_chk_data_crc:1;
	unsigned int bulk_read:1;
	unsigned int default_compr:2;
	unsigned int rw_incompat:1;

	struct mutex tnc_mutex;
	struct ubifs_zbranch zroot;
	struct ubifs_znode *cnext;
	struct ubifs_znode *enext;
	int *gap_lebs;
	void *cbuf;
	void *ileb_buf;
	int ileb_len;
	int ihead_lnum;
	int ihead_offs;
	int *ilebs;
	int ileb_cnt;
	int ileb_nxt;
	struct rb_root old_idx;
	int *bottom_up_buf;

	struct ubifs_mst_node *mst_node;
	int mst_offs;
	struct mutex mst_mutex;

	int max_bu_buf_len;
	struct mutex bu_mutex;
	struct bu_info bu;

	struct mutex write_reserve_mutex;
	void *write_reserve_buf;

	int log_lebs;
	long long log_bytes;
	int log_last;
	int lpt_lebs;
	int lpt_first;
	int lpt_last;
	int orph_lebs;
	int orph_first;
	int orph_last;
	int main_lebs;
	int main_first;
	long long main_bytes;

	uint8_t key_hash_type;
	uint32_t (*key_hash)(const char *str, int len);
	int key_fmt;
	int key_len;
	int fanout;

	int min_io_size;
	int min_io_shift;
	int max_write_size;
	int max_write_shift;
	int leb_size;
	int leb_start;
	int half_leb_size;
	int idx_leb_size;
	int leb_cnt;
	int max_leb_cnt;
	int old_leb_cnt;
	unsigned int ro_media:1;
	unsigned int ro_mount:1;
	unsigned int ro_error:1;

	atomic_long_t dirty_pg_cnt;
	atomic_long_t dirty_zn_cnt;
	atomic_long_t clean_zn_cnt;

	spinlock_t space_lock;
	struct ubifs_lp_stats lst;
	struct ubifs_budg_info bi;
	unsigned long long calc_idx_sz;

	int ref_node_alsz;
	int mst_node_alsz;
	int min_idx_node_sz;
	int max_idx_node_sz;
	long long max_inode_sz;
	int max_znode_sz;

	int leb_overhead;
	int dead_wm;
	int dark_wm;
	int block_cnt;

	struct ubifs_node_range ranges[UBIFS_NODE_TYPES_CNT];
	struct ubi_volume_desc *ubi;
	struct ubi_device_info di;
	struct ubi_volume_info vi;

	struct rb_root orph_tree;
	struct list_head orph_list;
	struct list_head orph_new;
	struct ubifs_orphan *orph_cnext;
	struct ubifs_orphan *orph_dnext;
	spinlock_t orphan_lock;
	void *orph_buf;
	int new_orphans;
	int cmt_orphans;
	int tot_orphans;
	int max_orphans;
	int ohead_lnum;
	int ohead_offs;
	int no_orphs;

	struct task_struct *bgt;
	char bgt_name[sizeof(BGT_NAME_PATTERN) + 9];
	int need_bgt;
	int need_wbuf_sync;

	int gc_lnum;
	void *sbuf;
	struct list_head idx_gc;
	int idx_gc_cnt;
	int gc_seq;
	int gced_lnum;

	struct list_head infos_list;
	struct mutex umount_mutex;
	unsigned int shrinker_run_no;

	int space_bits;
	int lpt_lnum_bits;
	int lpt_offs_bits;
	int lpt_spc_bits;
	int pcnt_bits;
	int lnum_bits;
	int nnode_sz;
	int pnode_sz;
	int ltab_sz;
	int lsave_sz;
	int pnode_cnt;
	int nnode_cnt;
	int lpt_hght;
	int pnodes_have;

	struct mutex lp_mutex;
	int lpt_lnum;
	int lpt_offs;
	int nhead_lnum;
	int nhead_offs;
	int lpt_drty_flgs;
	int dirty_nn_cnt;
	int dirty_pn_cnt;
	int check_lpt_free;
	long long lpt_sz;
	void *lpt_nod_buf;
	void *lpt_buf;
	struct ubifs_nnode *nroot;
	struct ubifs_cnode *lpt_cnext;
	struct ubifs_lpt_heap lpt_heap[LPROPS_HEAP_CNT];
	struct ubifs_lpt_heap dirty_idx;
	struct list_head uncat_list;
	struct list_head empty_list;
	struct list_head freeable_list;
	struct list_head frdi_idx_list;
	int freeable_cnt;

	int ltab_lnum;
	int ltab_offs;
	struct ubifs_lpt_lprops *ltab;
	struct ubifs_lpt_lprops *ltab_cmt;
	int lsave_cnt;
	int lsave_lnum;
	int lsave_offs;
	int *lsave;
	int lscan_lnum;

	long long rp_size;
	long long report_rp_size;
	uid_t rp_uid;
	gid_t rp_gid;

	/* The below fields are used only during mounting and re-mounting */
	unsigned int empty:1;
	unsigned int need_recovery:1;
	unsigned int replaying:1;
	unsigned int mounting:1;
	unsigned int remounting_rw:1;
	struct list_head replay_list;
	struct list_head replay_buds;
	unsigned long long cs_sqnum;
	unsigned long long replay_sqnum;
	struct list_head unclean_leb_list;
	struct ubifs_mst_node *rcvrd_mst_node;
	struct rb_root size_tree;
	struct ubifs_mount_opts mount_opts;

#ifdef CONFIG_UBIFS_FS_DEBUG
	struct ubifs_debug_info *dbg;
#endif
};

extern struct list_head ubifs_infos;
extern spinlock_t ubifs_infos_lock;
extern atomic_long_t ubifs_clean_zn_cnt;
extern struct kmem_cache *ubifs_inode_slab;
extern const struct super_operations ubifs_super_operations;
extern const struct address_space_operations ubifs_file_address_operations;
extern const struct file_operations ubifs_file_operations;
extern const struct inode_operations ubifs_file_inode_operations;
extern const struct file_operations ubifs_dir_operations;
extern const struct inode_operations ubifs_dir_inode_operations;
extern const struct inode_operations ubifs_symlink_inode_operations;
extern struct backing_dev_info ubifs_backing_dev_info;
extern struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];

/* io.c */
void ubifs_ro_mode(struct ubifs_info *c, int err);
int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs,
		   int len, int even_ebadmsg);
int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs,
		    int len, int dtype);
int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len,
		     int dtype);
int ubifs_leb_unmap(struct ubifs_info *c, int lnum);
int ubifs_leb_map(struct ubifs_info *c, int lnum, int dtype);
int ubifs_is_mapped(const struct ubifs_info *c, int lnum);
int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len);
int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs,
			   int dtype);
int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf);
int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
		    int lnum, int offs);
int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
			 int lnum, int offs);
int ubifs_write_node(struct ubifs_info *c, void *node, int len, int lnum,
		     int offs, int dtype);
int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
		     int offs, int quiet, int must_chk_crc);
void ubifs_prepare_node(struct ubifs_info *c, void *buf, int len, int pad);
void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last);
int ubifs_io_init(struct ubifs_info *c);
void ubifs_pad(const struct ubifs_info *c, void *buf, int pad);
int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf);
int ubifs_bg_wbufs_sync(struct ubifs_info *c);
void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum);
int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode);

/* scan.c */
struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum,
				  int offs, void *sbuf, int quiet);
void ubifs_scan_destroy(struct ubifs_scan_leb *sleb);
int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum,
		      int offs, int quiet);
struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum,
					int offs, void *sbuf);
void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
		    int lnum, int offs);
int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
		   void *buf, int offs);
void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
			      void *buf);

/* log.c */
void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud);
void ubifs_create_buds_lists(struct ubifs_info *c);
int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs);
struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum);
struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum);
int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum);
int ubifs_log_end_commit(struct ubifs_info *c, int new_ltail_lnum);
int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum);
int ubifs_consolidate_log(struct ubifs_info *c);

/* journal.c */
int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
		     const struct qstr *nm, const struct inode *inode,
		     int deletion, int xent);
int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
			 const union ubifs_key *key, const void *buf, int len);
int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode);
int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode);
int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
		     const struct dentry *old_dentry,
		     const struct inode *new_dir,
		     const struct dentry *new_dentry, int sync);
int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
		       loff_t old_size, loff_t new_size);
int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,
			   const struct inode *inode, const struct qstr *nm);
int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode1,
			   const struct inode *inode2);

/* budget.c */
int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req);
void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req);
void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
				      struct ubifs_inode *ui);
int ubifs_budget_inode_op(struct ubifs_info *c, struct inode *inode,
			  struct ubifs_budget_req *req);
void ubifs_release_ino_dirty(struct ubifs_info *c, struct inode *inode,
				struct ubifs_budget_req *req);
void ubifs_cancel_ino_op(struct ubifs_info *c, struct inode *inode,
			 struct ubifs_budget_req *req);
long long ubifs_get_free_space(struct ubifs_info *c);
long long ubifs_get_free_space_nolock(struct ubifs_info *c);
int ubifs_calc_min_idx_lebs(struct ubifs_info *c);
void ubifs_convert_page_budget(struct ubifs_info *c);
long long ubifs_reported_space(const struct ubifs_info *c, long long free);
long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs);

/* find.c */
int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *offs,
			  int squeeze);
int ubifs_find_free_leb_for_idx(struct ubifs_info *c);
int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
			 int min_space, int pick_free);
int ubifs_find_dirty_idx_leb(struct ubifs_info *c);
int ubifs_save_dirty_idx_lnums(struct ubifs_info *c);

/* tnc.c */
int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
			struct ubifs_znode **zn, int *n);
int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
			void *node, const struct qstr *nm);
int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
		     void *node, int *lnum, int *offs);
int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
		  int offs, int len);
int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
		      int old_lnum, int old_offs, int lnum, int offs, int len);
int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
		     int lnum, int offs, int len, const struct qstr *nm);
int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key);
int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
			const struct qstr *nm);
int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
			   union ubifs_key *to_key);
int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum);
struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
					   union ubifs_key *key,
					   const struct qstr *nm);
void ubifs_tnc_close(struct ubifs_info *c);
int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level,
		       int lnum, int offs, int is_idx);
int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level,
			 int lnum, int offs);
/* Shared by tnc.c for tnc_commit.c */
void destroy_old_idx(struct ubifs_info *c);
int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level,
		       int lnum, int offs);
int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode);
int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu);
int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu);

/* tnc_misc.c */
struct ubifs_znode *ubifs_tnc_levelorder_next(struct ubifs_znode *zr,
					      struct ubifs_znode *znode);
int ubifs_search_zbranch(const struct ubifs_info *c,
			 const struct ubifs_znode *znode,
			 const union ubifs_key *key, int *n);
struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode);
struct ubifs_znode *ubifs_tnc_postorder_next(struct ubifs_znode *znode);
long ubifs_destroy_tnc_subtree(struct ubifs_znode *zr);
struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c,
				     struct ubifs_zbranch *zbr,
				     struct ubifs_znode *parent, int iip);
int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr,
			void *node);

/* tnc_commit.c */
int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot);
int ubifs_tnc_end_commit(struct ubifs_info *c);

/* shrinker.c */
int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc);

/* commit.c */
int ubifs_bg_thread(void *info);
void ubifs_commit_required(struct ubifs_info *c);
void ubifs_request_bg_commit(struct ubifs_info *c);
int ubifs_run_commit(struct ubifs_info *c);
void ubifs_recovery_commit(struct ubifs_info *c);
int ubifs_gc_should_commit(struct ubifs_info *c);
void ubifs_wait_for_commit(struct ubifs_info *c);

/* master.c */
int ubifs_read_master(struct ubifs_info *c);
int ubifs_write_master(struct ubifs_info *c);

/* sb.c */
int ubifs_read_superblock(struct ubifs_info *c);
struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c);
int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup);
int ubifs_fixup_free_space(struct ubifs_info *c);

/* replay.c */
int ubifs_validate_entry(struct ubifs_info *c,
			 const struct ubifs_dent_node *dent);
int ubifs_replay_journal(struct ubifs_info *c);

/* gc.c */
int ubifs_garbage_collect(struct ubifs_info *c, int anyway);
int ubifs_gc_start_commit(struct ubifs_info *c);
int ubifs_gc_end_commit(struct ubifs_info *c);
void ubifs_destroy_idx_gc(struct ubifs_info *c);
int ubifs_get_idx_gc_leb(struct ubifs_info *c);
int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp);

/* orphan.c */
int ubifs_add_orphan(struct ubifs_info *c, ino_t inum);
void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum);
int ubifs_orphan_start_commit(struct ubifs_info *c);
int ubifs_orphan_end_commit(struct ubifs_info *c);
int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only);
int ubifs_clear_orphans(struct ubifs_info *c);

/* lpt.c */
int ubifs_calc_lpt_geom(struct ubifs_info *c);
int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
			  int *lpt_lebs, int *big_lpt);
int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr);
struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum);
struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum);
int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
			  ubifs_lpt_scan_callback scan_cb, void *data);

/* Shared by lpt.c for lpt_commit.c */
void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave);
void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
		     struct ubifs_lpt_lprops *ltab);
void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
		      struct ubifs_pnode *pnode);
void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
		      struct ubifs_nnode *nnode);
struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
				    struct ubifs_nnode *parent, int iip);
struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
				    struct ubifs_nnode *parent, int iip);
int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip);
void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty);
void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode);
uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits);
struct ubifs_nnode *ubifs_first_nnode(struct ubifs_info *c, int *hght);
/* Needed only in debugging code in lpt_commit.c */
int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
		       struct ubifs_nnode *nnode);

/* lpt_commit.c */
int ubifs_lpt_start_commit(struct ubifs_info *c);
int ubifs_lpt_end_commit(struct ubifs_info *c);
int ubifs_lpt_post_commit(struct ubifs_info *c);
void ubifs_lpt_free(struct ubifs_info *c, int wr_only);

/* lprops.c */
const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
					   const struct ubifs_lprops *lp,
					   int free, int dirty, int flags,
					   int idx_gc_cnt);
void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst);
void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
		      int cat);
void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
		       struct ubifs_lprops *new_lprops);
void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops);
int ubifs_categorize_lprops(const struct ubifs_info *c,
			    const struct ubifs_lprops *lprops);
int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
			int flags_set, int flags_clean, int idx_gc_cnt);
int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
			int flags_set, int flags_clean);
int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp);
const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c);
const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c);
const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c);
const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c);
int ubifs_calc_dark(const struct ubifs_info *c, int spc);

/* file.c */
int ubifs_fsync(struct file *file, int datasync);
int ubifs_setattr(struct dentry *dentry, struct iattr *attr);

/* dir.c */
struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
			      int mode);
int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
		  struct kstat *stat);

/* xattr.c */
int ubifs_setxattr(struct dentry *dentry, const char *name,
		   const void *value, size_t size, int flags);
ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
		       size_t size);
ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size);
int ubifs_removexattr(struct dentry *dentry, const char *name);

/* super.c */
struct inode *ubifs_iget(struct super_block *sb, unsigned long inum);

/* recovery.c */
int ubifs_recover_master_node(struct ubifs_info *c);
int ubifs_write_rcvrd_mst_node(struct ubifs_info *c);
struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
					 int offs, void *sbuf, int jhead);
struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum,
					     int offs, void *sbuf);
int ubifs_recover_inl_heads(struct ubifs_info *c, void *sbuf);
int ubifs_clean_lebs(struct ubifs_info *c, void *sbuf);
int ubifs_rcvry_gc_commit(struct ubifs_info *c);
int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key,
			     int deletion, loff_t new_size);
int ubifs_recover_size(struct ubifs_info *c);
void ubifs_destroy_size_tree(struct ubifs_info *c);

/* ioctl.c */
long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
void ubifs_set_inode_flags(struct inode *inode);
#ifdef CONFIG_COMPAT
long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
#endif

/* compressor.c */
int __init ubifs_compressors_init(void);
void ubifs_compressors_exit(void);
void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
		    int *compr_type);
int ubifs_decompress(const void *buf, int len, void *out, int *out_len,
		     int compr_type);

#include "debug.h"
#include "misc.h"
#include "key.h"

#endif /* !__UBIFS_H__ */