summaryrefslogtreecommitdiff
path: root/fs/ubifs/lprops.c
blob: dfd2bcece27a865de970f3d4333468c5ebb5db66 (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
/*
 * 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: Adrian Hunter
 *          Artem Bityutskiy (Битюцкий Артём)
 */

/*
 * This file implements the functions that access LEB properties and their
 * categories. LEBs are categorized based on the needs of UBIFS, and the
 * categories are stored as either heaps or lists to provide a fast way of
 * finding a LEB in a particular category. For example, UBIFS may need to find
 * an empty LEB for the journal, or a very dirty LEB for garbage collection.
 */

#include "ubifs.h"

/**
 * get_heap_comp_val - get the LEB properties value for heap comparisons.
 * @lprops: LEB properties
 * @cat: LEB category
 */
static int get_heap_comp_val(struct ubifs_lprops *lprops, int cat)
{
	switch (cat) {
	case LPROPS_FREE:
		return lprops->free;
	case LPROPS_DIRTY_IDX:
		return lprops->free + lprops->dirty;
	default:
		return lprops->dirty;
	}
}

/**
 * move_up_lpt_heap - move a new heap entry up as far as possible.
 * @c: UBIFS file-system description object
 * @heap: LEB category heap
 * @lprops: LEB properties to move
 * @cat: LEB category
 *
 * New entries to a heap are added at the bottom and then moved up until the
 * parent's value is greater.  In the case of LPT's category heaps, the value
 * is either the amount of free space or the amount of dirty space, depending
 * on the category.
 */
static void move_up_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
			     struct ubifs_lprops *lprops, int cat)
{
	int val1, val2, hpos;

	hpos = lprops->hpos;
	if (!hpos)
		return; /* Already top of the heap */
	val1 = get_heap_comp_val(lprops, cat);
	/* Compare to parent and, if greater, move up the heap */
	do {
		int ppos = (hpos - 1) / 2;

		val2 = get_heap_comp_val(heap->arr[ppos], cat);
		if (val2 >= val1)
			return;
		/* Greater than parent so move up */
		heap->arr[ppos]->hpos = hpos;
		heap->arr[hpos] = heap->arr[ppos];
		heap->arr[ppos] = lprops;
		lprops->hpos = ppos;
		hpos = ppos;
	} while (hpos);
}

/**
 * adjust_lpt_heap - move a changed heap entry up or down the heap.
 * @c: UBIFS file-system description object
 * @heap: LEB category heap
 * @lprops: LEB properties to move
 * @hpos: heap position of @lprops
 * @cat: LEB category
 *
 * Changed entries in a heap are moved up or down until the parent's value is
 * greater.  In the case of LPT's category heaps, the value is either the amount
 * of free space or the amount of dirty space, depending on the category.
 */
static void adjust_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
			    struct ubifs_lprops *lprops, int hpos, int cat)
{
	int val1, val2, val3, cpos;

	val1 = get_heap_comp_val(lprops, cat);
	/* Compare to parent and, if greater than parent, move up the heap */
	if (hpos) {
		int ppos = (hpos - 1) / 2;

		val2 = get_heap_comp_val(heap->arr[ppos], cat);
		if (val1 > val2) {
			/* Greater than parent so move up */
			while (1) {
				heap->arr[ppos]->hpos = hpos;
				heap->arr[hpos] = heap->arr[ppos];
				heap->arr[ppos] = lprops;
				lprops->hpos = ppos;
				hpos = ppos;
				if (!hpos)
					return;
				ppos = (hpos - 1) / 2;
				val2 = get_heap_comp_val(heap->arr[ppos], cat);
				if (val1 <= val2)
					return;
				/* Still greater than parent so keep going */
			}
		}
	}

	/* Not greater than parent, so compare to children */
	while (1) {
		/* Compare to left child */
		cpos = hpos * 2 + 1;
		if (cpos >= heap->cnt)
			return;
		val2 = get_heap_comp_val(heap->arr[cpos], cat);
		if (val1 < val2) {
			/* Less than left child, so promote biggest child */
			if (cpos + 1 < heap->cnt) {
				val3 = get_heap_comp_val(heap->arr[cpos + 1],
							 cat);
				if (val3 > val2)
					cpos += 1; /* Right child is bigger */
			}
			heap->arr[cpos]->hpos = hpos;
			heap->arr[hpos] = heap->arr[cpos];
			heap->arr[cpos] = lprops;
			lprops->hpos = cpos;
			hpos = cpos;
			continue;
		}
		/* Compare to right child */
		cpos += 1;
		if (cpos >= heap->cnt)
			return;
		val3 = get_heap_comp_val(heap->arr[cpos], cat);
		if (val1 < val3) {
			/* Less than right child, so promote right child */
			heap->arr[cpos]->hpos = hpos;
			heap->arr[hpos] = heap->arr[cpos];
			heap->arr[cpos] = lprops;
			lprops->hpos = cpos;
			hpos = cpos;
			continue;
		}
		return;
	}
}

/**
 * add_to_lpt_heap - add LEB properties to a LEB category heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to add
 * @cat: LEB category
 *
 * This function returns %1 if @lprops is added to the heap for LEB category
 * @cat, otherwise %0 is returned because the heap is full.
 */
static int add_to_lpt_heap(struct ubifs_info *c, struct ubifs_lprops *lprops,
			   int cat)
{
	struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];

	if (heap->cnt >= heap->max_cnt) {
		const int b = LPT_HEAP_SZ / 2 - 1;
		int cpos, val1, val2;

		/* Compare to some other LEB on the bottom of heap */
		/* Pick a position kind of randomly */
		cpos = (((size_t)lprops >> 4) & b) + b;
		ubifs_assert(cpos >= b);
		ubifs_assert(cpos < LPT_HEAP_SZ);
		ubifs_assert(cpos < heap->cnt);

		val1 = get_heap_comp_val(lprops, cat);
		val2 = get_heap_comp_val(heap->arr[cpos], cat);
		if (val1 > val2) {
			struct ubifs_lprops *lp;

			lp = heap->arr[cpos];
			lp->flags &= ~LPROPS_CAT_MASK;
			lp->flags |= LPROPS_UNCAT;
			list_add(&lp->list, &c->uncat_list);
			lprops->hpos = cpos;
			heap->arr[cpos] = lprops;
			move_up_lpt_heap(c, heap, lprops, cat);
			dbg_check_heap(c, heap, cat, lprops->hpos);
			return 1; /* Added to heap */
		}
		dbg_check_heap(c, heap, cat, -1);
		return 0; /* Not added to heap */
	} else {
		lprops->hpos = heap->cnt++;
		heap->arr[lprops->hpos] = lprops;
		move_up_lpt_heap(c, heap, lprops, cat);
		dbg_check_heap(c, heap, cat, lprops->hpos);
		return 1; /* Added to heap */
	}
}

/**
 * remove_from_lpt_heap - remove LEB properties from a LEB category heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to remove
 * @cat: LEB category
 */
static void remove_from_lpt_heap(struct ubifs_info *c,
				 struct ubifs_lprops *lprops, int cat)
{
	struct ubifs_lpt_heap *heap;
	int hpos = lprops->hpos;

	heap = &c->lpt_heap[cat - 1];
	ubifs_assert(hpos >= 0 && hpos < heap->cnt);
	ubifs_assert(heap->arr[hpos] == lprops);
	heap->cnt -= 1;
	if (hpos < heap->cnt) {
		heap->arr[hpos] = heap->arr[heap->cnt];
		heap->arr[hpos]->hpos = hpos;
		adjust_lpt_heap(c, heap, heap->arr[hpos], hpos, cat);
	}
	dbg_check_heap(c, heap, cat, -1);
}

/**
 * lpt_heap_replace - replace lprops in a category heap.
 * @c: UBIFS file-system description object
 * @old_lprops: LEB properties to replace
 * @new_lprops: LEB properties with which to replace
 * @cat: LEB category
 *
 * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
 * and the lprops that the pnode contains.  When that happens, references in
 * the category heaps to those lprops must be updated to point to the new
 * lprops.  This function does that.
 */
static void lpt_heap_replace(struct ubifs_info *c,
			     struct ubifs_lprops *old_lprops,
			     struct ubifs_lprops *new_lprops, int cat)
{
	struct ubifs_lpt_heap *heap;
	int hpos = new_lprops->hpos;

	heap = &c->lpt_heap[cat - 1];
	heap->arr[hpos] = new_lprops;
}

/**
 * ubifs_add_to_cat - add LEB properties to a category list or heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to add
 * @cat: LEB category to which to add
 *
 * LEB properties are categorized to enable fast find operations.
 */
void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
		      int cat)
{
	switch (cat) {
	case LPROPS_DIRTY:
	case LPROPS_DIRTY_IDX:
	case LPROPS_FREE:
		if (add_to_lpt_heap(c, lprops, cat))
			break;
		/* No more room on heap so make it uncategorized */
		cat = LPROPS_UNCAT;
		/* Fall through */
	case LPROPS_UNCAT:
		list_add(&lprops->list, &c->uncat_list);
		break;
	case LPROPS_EMPTY:
		list_add(&lprops->list, &c->empty_list);
		break;
	case LPROPS_FREEABLE:
		list_add(&lprops->list, &c->freeable_list);
		c->freeable_cnt += 1;
		break;
	case LPROPS_FRDI_IDX:
		list_add(&lprops->list, &c->frdi_idx_list);
		break;
	default:
		ubifs_assert(0);
	}
	lprops->flags &= ~LPROPS_CAT_MASK;
	lprops->flags |= cat;
}

/**
 * ubifs_remove_from_cat - remove LEB properties from a category list or heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to remove
 * @cat: LEB category from which to remove
 *
 * LEB properties are categorized to enable fast find operations.
 */
static void ubifs_remove_from_cat(struct ubifs_info *c,
				  struct ubifs_lprops *lprops, int cat)
{
	switch (cat) {
	case LPROPS_DIRTY:
	case LPROPS_DIRTY_IDX:
	case LPROPS_FREE:
		remove_from_lpt_heap(c, lprops, cat);
		break;
	case LPROPS_FREEABLE:
		c->freeable_cnt -= 1;
		ubifs_assert(c->freeable_cnt >= 0);
		/* Fall through */
	case LPROPS_UNCAT:
	case LPROPS_EMPTY:
	case LPROPS_FRDI_IDX:
		ubifs_assert(!list_empty(&lprops->list));
		list_del(&lprops->list);
		break;
	default:
		ubifs_assert(0);
	}
}

/**
 * ubifs_replace_cat - replace lprops in a category list or heap.
 * @c: UBIFS file-system description object
 * @old_lprops: LEB properties to replace
 * @new_lprops: LEB properties with which to replace
 *
 * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
 * and the lprops that the pnode contains. When that happens, references in
 * category lists and heaps must be replaced. This function does that.
 */
void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
		       struct ubifs_lprops *new_lprops)
{
	int cat;

	cat = new_lprops->flags & LPROPS_CAT_MASK;
	switch (cat) {
	case LPROPS_DIRTY:
	case LPROPS_DIRTY_IDX:
	case LPROPS_FREE:
		lpt_heap_replace(c, old_lprops, new_lprops, cat);
		break;
	case LPROPS_UNCAT:
	case LPROPS_EMPTY:
	case LPROPS_FREEABLE:
	case LPROPS_FRDI_IDX:
		list_replace(&old_lprops->list, &new_lprops->list);
		break;
	default:
		ubifs_assert(0);
	}
}

/**
 * ubifs_ensure_cat - ensure LEB properties are categorized.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties
 *
 * A LEB may have fallen off of the bottom of a heap, and ended up as
 * uncategorized even though it has enough space for us now. If that is the case
 * this function will put the LEB back onto a heap.
 */
void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops)
{
	int cat = lprops->flags & LPROPS_CAT_MASK;

	if (cat != LPROPS_UNCAT)
		return;
	cat = ubifs_categorize_lprops(c, lprops);
	if (cat == LPROPS_UNCAT)
		return;
	ubifs_remove_from_cat(c, lprops, LPROPS_UNCAT);
	ubifs_add_to_cat(c, lprops, cat);
}

/**
 * ubifs_categorize_lprops - categorize LEB properties.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to categorize
 *
 * LEB properties are categorized to enable fast find operations. This function
 * returns the LEB category to which the LEB properties belong. Note however
 * that if the LEB category is stored as a heap and the heap is full, the
 * LEB properties may have their category changed to %LPROPS_UNCAT.
 */
int ubifs_categorize_lprops(const struct ubifs_info *c,
			    const struct ubifs_lprops *lprops)
{
	if (lprops->flags & LPROPS_TAKEN)
		return LPROPS_UNCAT;

	if (lprops->free == c->leb_size) {
		ubifs_assert(!(lprops->flags & LPROPS_INDEX));
		return LPROPS_EMPTY;
	}

	if (lprops->free + lprops->dirty == c->leb_size) {
		if (lprops->flags & LPROPS_INDEX)
			return LPROPS_FRDI_IDX;
		else
			return LPROPS_FREEABLE;
	}

	if (lprops->flags & LPROPS_INDEX) {
		if (lprops->dirty + lprops->free >= c->min_idx_node_sz)
			return LPROPS_DIRTY_IDX;
	} else {
		if (lprops->dirty >= c->dead_wm &&
		    lprops->dirty > lprops->free)
			return LPROPS_DIRTY;
		if (lprops->free > 0)
			return LPROPS_FREE;
	}

	return LPROPS_UNCAT;
}

/**
 * change_category - change LEB properties category.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to recategorize
 *
 * LEB properties are categorized to enable fast find operations. When the LEB
 * properties change they must be recategorized.
 */
static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
{
	int old_cat = lprops->flags & LPROPS_CAT_MASK;
	int new_cat = ubifs_categorize_lprops(c, lprops);

	if (old_cat == new_cat) {
		struct ubifs_lpt_heap *heap = &c->lpt_heap[new_cat - 1];

		/* lprops on a heap now must be moved up or down */
		if (new_cat < 1 || new_cat > LPROPS_HEAP_CNT)
			return; /* Not on a heap */
		heap = &c->lpt_heap[new_cat - 1];
		adjust_lpt_heap(c, heap, lprops, lprops->hpos, new_cat);
	} else {
		ubifs_remove_from_cat(c, lprops, old_cat);
		ubifs_add_to_cat(c, lprops, new_cat);
	}
}

/**
 * calc_dark - calculate LEB dark space size.
 * @c: the UBIFS file-system description object
 * @spc: amount of free and dirty space in the LEB
 *
 * This function calculates amount of dark space in an LEB which has @spc bytes
 * of free and dirty space. Returns the calculations result.
 *
 * Dark space is the space which is not always usable - it depends on which
 * nodes are written in which order. E.g., if an LEB has only 512 free bytes,
 * it is dark space, because it cannot fit a large data node. So UBIFS cannot
 * count on this LEB and treat these 512 bytes as usable because it is not true
 * if, for example, only big chunks of uncompressible data will be written to
 * the FS.
 */
static int calc_dark(struct ubifs_info *c, int spc)
{
	ubifs_assert(!(spc & 7));

	if (spc < c->dark_wm)
		return spc;

	/*
	 * If we have slightly more space then the dark space watermark, we can
	 * anyway safely assume it we'll be able to write a node of the
	 * smallest size there.
	 */
	if (spc - c->dark_wm < MIN_WRITE_SZ)
		return spc - MIN_WRITE_SZ;

	return c->dark_wm;
}

/**
 * is_lprops_dirty - determine if LEB properties are dirty.
 * @c: the UBIFS file-system description object
 * @lprops: LEB properties to test
 */
static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops)
{
	struct ubifs_pnode *pnode;
	int pos;

	pos = (lprops->lnum - c->main_first) & (UBIFS_LPT_FANOUT - 1);
	pnode = (struct ubifs_pnode *)container_of(lprops - pos,
						   struct ubifs_pnode,
						   lprops[0]);
	return !test_bit(COW_ZNODE, &pnode->flags) &&
	       test_bit(DIRTY_CNODE, &pnode->flags);
}

/**
 * ubifs_change_lp - change LEB properties.
 * @c: the UBIFS file-system description object
 * @lp: LEB properties to change
 * @free: new free space amount
 * @dirty: new dirty space amount
 * @flags: new flags
 * @idx_gc_cnt: change to the count of idx_gc list
 *
 * This function changes LEB properties (@free, @dirty or @flag). However, the
 * property which has the %LPROPS_NC value is not changed. Returns a pointer to
 * the updated LEB properties on success and a negative error code on failure.
 *
 * Note, the LEB properties may have had to be copied (due to COW) and
 * consequently the pointer returned may not be the same as the pointer
 * passed.
 */
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)
{
	/*
	 * This is the only function that is allowed to change lprops, so we
	 * discard the const qualifier.
	 */
	struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp;

	dbg_lp("LEB %d, free %d, dirty %d, flags %d",
	       lprops->lnum, free, dirty, flags);

	ubifs_assert(mutex_is_locked(&c->lp_mutex));
	ubifs_assert(c->lst.empty_lebs >= 0 &&
		     c->lst.empty_lebs <= c->main_lebs);
	ubifs_assert(c->freeable_cnt >= 0);
	ubifs_assert(c->freeable_cnt <= c->main_lebs);
	ubifs_assert(c->lst.taken_empty_lebs >= 0);
	ubifs_assert(c->lst.taken_empty_lebs <= c->lst.empty_lebs);
	ubifs_assert(!(c->lst.total_free & 7) && !(c->lst.total_dirty & 7));
	ubifs_assert(!(c->lst.total_dead & 7) && !(c->lst.total_dark & 7));
	ubifs_assert(!(c->lst.total_used & 7));
	ubifs_assert(free == LPROPS_NC || free >= 0);
	ubifs_assert(dirty == LPROPS_NC || dirty >= 0);

	if (!is_lprops_dirty(c, lprops)) {
		lprops = ubifs_lpt_lookup_dirty(c, lprops->lnum);
		if (IS_ERR(lprops))
			return lprops;
	} else
		ubifs_assert(lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum));

	ubifs_assert(!(lprops->free & 7) && !(lprops->dirty & 7));

	spin_lock(&c->space_lock);
	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
		c->lst.taken_empty_lebs -= 1;

	if (!(lprops->flags & LPROPS_INDEX)) {
		int old_spc;

		old_spc = lprops->free + lprops->dirty;
		if (old_spc < c->dead_wm)
			c->lst.total_dead -= old_spc;
		else
			c->lst.total_dark -= calc_dark(c, old_spc);

		c->lst.total_used -= c->leb_size - old_spc;
	}

	if (free != LPROPS_NC) {
		free = ALIGN(free, 8);
		c->lst.total_free += free - lprops->free;

		/* Increase or decrease empty LEBs counter if needed */
		if (free == c->leb_size) {
			if (lprops->free != c->leb_size)
				c->lst.empty_lebs += 1;
		} else if (lprops->free == c->leb_size)
			c->lst.empty_lebs -= 1;
		lprops->free = free;
	}

	if (dirty != LPROPS_NC) {
		dirty = ALIGN(dirty, 8);
		c->lst.total_dirty += dirty - lprops->dirty;
		lprops->dirty = dirty;
	}

	if (flags != LPROPS_NC) {
		/* Take care about indexing LEBs counter if needed */
		if ((lprops->flags & LPROPS_INDEX)) {
			if (!(flags & LPROPS_INDEX))
				c->lst.idx_lebs -= 1;
		} else if (flags & LPROPS_INDEX)
			c->lst.idx_lebs += 1;
		lprops->flags = flags;
	}

	if (!(lprops->flags & LPROPS_INDEX)) {
		int new_spc;

		new_spc = lprops->free + lprops->dirty;
		if (new_spc < c->dead_wm)
			c->lst.total_dead += new_spc;
		else
			c->lst.total_dark += calc_dark(c, new_spc);

		c->lst.total_used += c->leb_size - new_spc;
	}

	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
		c->lst.taken_empty_lebs += 1;

	change_category(c, lprops);
	c->idx_gc_cnt += idx_gc_cnt;
	spin_unlock(&c->space_lock);
	return lprops;
}

/**
 * ubifs_get_lp_stats - get lprops statistics.
 * @c: UBIFS file-system description object
 * @st: return statistics
 */
void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *st)
{
	spin_lock(&c->space_lock);
	memcpy(st, &c->lst, sizeof(struct ubifs_lp_stats));
	spin_unlock(&c->space_lock);
}

/**
 * ubifs_change_one_lp - change LEB properties.
 * @c: the UBIFS file-system description object
 * @lnum: LEB to change properties for
 * @free: amount of free space
 * @dirty: amount of dirty space
 * @flags_set: flags to set
 * @flags_clean: flags to clean
 * @idx_gc_cnt: change to the count of idx_gc list
 *
 * This function changes properties of LEB @lnum. It is a helper wrapper over
 * 'ubifs_change_lp()' which hides lprops get/release. The arguments are the
 * same as in case of 'ubifs_change_lp()'. Returns zero in case of success and
 * a negative error code in case of failure.
 */
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 err = 0, flags;
	const struct ubifs_lprops *lp;

	ubifs_get_lprops(c);

	lp = ubifs_lpt_lookup_dirty(c, lnum);
	if (IS_ERR(lp)) {
		err = PTR_ERR(lp);
		goto out;
	}

	flags = (lp->flags | flags_set) & ~flags_clean;
	lp = ubifs_change_lp(c, lp, free, dirty, flags, idx_gc_cnt);
	if (IS_ERR(lp))
		err = PTR_ERR(lp);

out:
	ubifs_release_lprops(c);
	return err;
}

/**
 * ubifs_update_one_lp - update LEB properties.
 * @c: the UBIFS file-system description object
 * @lnum: LEB to change properties for
 * @free: amount of free space
 * @dirty: amount of dirty space to add
 * @flags_set: flags to set
 * @flags_clean: flags to clean
 *
 * This function is the same as 'ubifs_change_one_lp()' but @dirty is added to
 * current dirty space, not substitutes it.
 */
int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
			int flags_set, int flags_clean)
{
	int err = 0, flags;
	const struct ubifs_lprops *lp;

	ubifs_get_lprops(c);

	lp = ubifs_lpt_lookup_dirty(c, lnum);
	if (IS_ERR(lp)) {
		err = PTR_ERR(lp);
		goto out;
	}

	flags = (lp->flags | flags_set) & ~flags_clean;
	lp = ubifs_change_lp(c, lp, free, lp->dirty + dirty, flags, 0);
	if (IS_ERR(lp))
		err = PTR_ERR(lp);

out:
	ubifs_release_lprops(c);
	return err;
}

/**
 * ubifs_read_one_lp - read LEB properties.
 * @c: the UBIFS file-system description object
 * @lnum: LEB to read properties for
 * @lp: where to store read properties
 *
 * This helper function reads properties of a LEB @lnum and stores them in @lp.
 * Returns zero in case of success and a negative error code in case of
 * failure.
 */
int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp)
{
	int err = 0;
	const struct ubifs_lprops *lpp;

	ubifs_get_lprops(c);

	lpp = ubifs_lpt_lookup(c, lnum);
	if (IS_ERR(lpp)) {
		err = PTR_ERR(lpp);
		goto out;
	}

	memcpy(lp, lpp, sizeof(struct ubifs_lprops));

out:
	ubifs_release_lprops(c);
	return err;
}

/**
 * ubifs_fast_find_free - try to find a LEB with free space quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for a LEB with free space or %NULL if
 * the function is unable to find a LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;
	struct ubifs_lpt_heap *heap;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	heap = &c->lpt_heap[LPROPS_FREE - 1];
	if (heap->cnt == 0)
		return NULL;

	lprops = heap->arr[0];
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
	return lprops;
}

/**
 * ubifs_fast_find_empty - try to find an empty LEB quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for an empty LEB or %NULL if the
 * function is unable to find an empty LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	if (list_empty(&c->empty_list))
		return NULL;

	lprops = list_entry(c->empty_list.next, struct ubifs_lprops, list);
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
	ubifs_assert(lprops->free == c->leb_size);
	return lprops;
}

/**
 * ubifs_fast_find_freeable - try to find a freeable LEB quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for a freeable LEB or %NULL if the
 * function is unable to find a freeable LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	if (list_empty(&c->freeable_list))
		return NULL;

	lprops = list_entry(c->freeable_list.next, struct ubifs_lprops, list);
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
	ubifs_assert(c->freeable_cnt > 0);
	return lprops;
}

/**
 * ubifs_fast_find_frdi_idx - try to find a freeable index LEB quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for a freeable index LEB or %NULL if the
 * function is unable to find a freeable index LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	if (list_empty(&c->frdi_idx_list))
		return NULL;

	lprops = list_entry(c->frdi_idx_list.next, struct ubifs_lprops, list);
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert((lprops->flags & LPROPS_INDEX));
	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
	return lprops;
}

#ifdef CONFIG_UBIFS_FS_DEBUG

/**
 * dbg_check_cats - check category heaps and lists.
 * @c: UBIFS file-system description object
 *
 * This function returns %0 on success and a negative error code on failure.
 */
int dbg_check_cats(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;
	struct list_head *pos;
	int i, cat;

	if (!(ubifs_chk_flags & (UBIFS_CHK_GEN | UBIFS_CHK_LPROPS)))
		return 0;

	list_for_each_entry(lprops, &c->empty_list, list) {
		if (lprops->free != c->leb_size) {
			ubifs_err("non-empty LEB %d on empty list "
				  "(free %d dirty %d flags %d)", lprops->lnum,
				  lprops->free, lprops->dirty, lprops->flags);
			return -EINVAL;
		}
		if (lprops->flags & LPROPS_TAKEN) {
			ubifs_err("taken LEB %d on empty list "
				  "(free %d dirty %d flags %d)", lprops->lnum,
				  lprops->free, lprops->dirty, lprops->flags);
			return -EINVAL;
		}
	}

	i = 0;
	list_for_each_entry(lprops, &c->freeable_list, list) {
		if (lprops->free + lprops->dirty != c->leb_size) {
			ubifs_err("non-freeable LEB %d on freeable list "
				  "(free %d dirty %d flags %d)", lprops->lnum,
				  lprops->free, lprops->dirty, lprops->flags);
			return -EINVAL;
		}
		if (lprops->flags & LPROPS_TAKEN) {
			ubifs_err("taken LEB %d on freeable list "
				  "(free %d dirty %d flags %d)", lprops->lnum,
				  lprops->free, lprops->dirty, lprops->flags);
			return -EINVAL;
		}
		i += 1;
	}
	if (i != c->freeable_cnt) {
		ubifs_err("freeable list count %d expected %d", i,
			  c->freeable_cnt);
		return -EINVAL;
	}

	i = 0;
	list_for_each(pos, &c->idx_gc)
		i += 1;
	if (i != c->idx_gc_cnt) {
		ubifs_err("idx_gc list count %d expected %d", i,
			  c->idx_gc_cnt);
		return -EINVAL;
	}

	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
		if (lprops->free + lprops->dirty != c->leb_size) {
			ubifs_err("non-freeable LEB %d on frdi_idx list "
				  "(free %d dirty %d flags %d)", lprops->lnum,
				  lprops->free, lprops->dirty, lprops->flags);
			return -EINVAL;
		}
		if (lprops->flags & LPROPS_TAKEN) {
			ubifs_err("taken LEB %d on frdi_idx list "
				  "(free %d dirty %d flags %d)", lprops->lnum,
				  lprops->free, lprops->dirty, lprops->flags);
			return -EINVAL;
		}
		if (!(lprops->flags & LPROPS_INDEX)) {
			ubifs_err("non-index LEB %d on frdi_idx list "
				  "(free %d dirty %d flags %d)", lprops->lnum,
				  lprops->free, lprops->dirty, lprops->flags);
			return -EINVAL;
		}
	}

	for (cat = 1; cat <= LPROPS_HEAP_CNT; cat++) {
		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];

		for (i = 0; i < heap->cnt; i++) {
			lprops = heap->arr[i];
			if (!lprops) {
				ubifs_err("null ptr in LPT heap cat %d", cat);
				return -EINVAL;
			}
			if (lprops->hpos != i) {
				ubifs_err("bad ptr in LPT heap cat %d", cat);
				return -EINVAL;
			}
			if (lprops->flags & LPROPS_TAKEN) {
				ubifs_err("taken LEB in LPT heap cat %d", cat);
				return -EINVAL;
			}
		}
	}

	return 0;
}

void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
		    int add_pos)
{
	int i = 0, j, err = 0;

	if (!(ubifs_chk_flags & (UBIFS_CHK_GEN | UBIFS_CHK_LPROPS)))
		return;

	for (i = 0; i < heap->cnt; i++) {
		struct ubifs_lprops *lprops = heap->arr[i];
		struct ubifs_lprops *lp;

		if (i != add_pos)
			if ((lprops->flags & LPROPS_CAT_MASK) != cat) {
				err = 1;
				goto out;
			}
		if (lprops->hpos != i) {
			err = 2;
			goto out;
		}
		lp = ubifs_lpt_lookup(c, lprops->lnum);
		if (IS_ERR(lp)) {
			err = 3;
			goto out;
		}
		if (lprops != lp) {
			dbg_msg("lprops %zx lp %zx lprops->lnum %d lp->lnum %d",
				(size_t)lprops, (size_t)lp, lprops->lnum,
				lp->lnum);
			err = 4;
			goto out;
		}
		for (j = 0; j < i; j++) {
			lp = heap->arr[j];
			if (lp == lprops) {
				err = 5;
				goto out;
			}
			if (lp->lnum == lprops->lnum) {
				err = 6;
				goto out;
			}
		}
	}
out:
	if (err) {
		dbg_msg("failed cat %d hpos %d err %d", cat, i, err);
		dbg_dump_stack();
		dbg_dump_heap(c, heap, cat);
	}
}

/**
 * struct scan_check_data - data provided to scan callback function.
 * @lst: LEB properties statistics
 * @err: error code
 */
struct scan_check_data {
	struct ubifs_lp_stats lst;
	int err;
};

/**
 * scan_check_cb - scan callback.
 * @c: the UBIFS file-system description object
 * @lp: LEB properties to scan
 * @in_tree: whether the LEB properties are in main memory
 * @data: information passed to and from the caller of the scan
 *
 * This function returns a code that indicates whether the scan should continue
 * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
 * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
 * (%LPT_SCAN_STOP).
 */
static int scan_check_cb(struct ubifs_info *c,
			 const struct ubifs_lprops *lp, int in_tree,
			 struct scan_check_data *data)
{
	struct ubifs_scan_leb *sleb;
	struct ubifs_scan_node *snod;
	struct ubifs_lp_stats *lst = &data->lst;
	int cat, lnum = lp->lnum, is_idx = 0, used = 0, free, dirty;

	cat = lp->flags & LPROPS_CAT_MASK;
	if (cat != LPROPS_UNCAT) {
		cat = ubifs_categorize_lprops(c, lp);
		if (cat != (lp->flags & LPROPS_CAT_MASK)) {
			ubifs_err("bad LEB category %d expected %d",
				  (lp->flags & LPROPS_CAT_MASK), cat);
			goto out;
		}
	}

	/* Check lp is on its category list (if it has one) */
	if (in_tree) {
		struct list_head *list = NULL;

		switch (cat) {
		case LPROPS_EMPTY:
			list = &c->empty_list;
			break;
		case LPROPS_FREEABLE:
			list = &c->freeable_list;
			break;
		case LPROPS_FRDI_IDX:
			list = &c->frdi_idx_list;
			break;
		case LPROPS_UNCAT:
			list = &c->uncat_list;
			break;
		}
		if (list) {
			struct ubifs_lprops *lprops;
			int found = 0;

			list_for_each_entry(lprops, list, list) {
				if (lprops == lp) {
					found = 1;
					break;
				}
			}
			if (!found) {
				ubifs_err("bad LPT list (category %d)", cat);
				goto out;
			}
		}
	}

	/* Check lp is on its category heap (if it has one) */
	if (in_tree && cat > 0 && cat <= LPROPS_HEAP_CNT) {
		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];

		if ((lp->hpos != -1 && heap->arr[lp->hpos]->lnum != lnum) ||
		    lp != heap->arr[lp->hpos]) {
			ubifs_err("bad LPT heap (category %d)", cat);
			goto out;
		}
	}

	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf);
	if (IS_ERR(sleb)) {
		/*
		 * After an unclean unmount, empty and freeable LEBs
		 * may contain garbage.
		 */
		if (lp->free == c->leb_size) {
			ubifs_err("scan errors were in empty LEB "
				  "- continuing checking");
			lst->empty_lebs += 1;
			lst->total_free += c->leb_size;
			lst->total_dark += calc_dark(c, c->leb_size);
			return LPT_SCAN_CONTINUE;
		}

		if (lp->free + lp->dirty == c->leb_size &&
		    !(lp->flags & LPROPS_INDEX)) {
			ubifs_err("scan errors were in freeable LEB "
				  "- continuing checking");
			lst->total_free  += lp->free;
			lst->total_dirty += lp->dirty;
			lst->total_dark  +=  calc_dark(c, c->leb_size);
			return LPT_SCAN_CONTINUE;
		}
		data->err = PTR_ERR(sleb);
		return LPT_SCAN_STOP;
	}

	is_idx = -1;
	list_for_each_entry(snod, &sleb->nodes, list) {
		int found, level = 0;

		cond_resched();

		if (is_idx == -1)
			is_idx = (snod->type == UBIFS_IDX_NODE) ? 1 : 0;

		if (is_idx && snod->type != UBIFS_IDX_NODE) {
			ubifs_err("indexing node in data LEB %d:%d",
				  lnum, snod->offs);
			goto out_destroy;
		}

		if (snod->type == UBIFS_IDX_NODE) {
			struct ubifs_idx_node *idx = snod->node;

			key_read(c, ubifs_idx_key(c, idx), &snod->key);
			level = le16_to_cpu(idx->level);
		}

		found = ubifs_tnc_has_node(c, &snod->key, level, lnum,
					   snod->offs, is_idx);
		if (found) {
			if (found < 0)
				goto out_destroy;
			used += ALIGN(snod->len, 8);
		}
	}

	free = c->leb_size - sleb->endpt;
	dirty = sleb->endpt - used;

	if (free > c->leb_size || free < 0 || dirty > c->leb_size ||
	    dirty < 0) {
		ubifs_err("bad calculated accounting for LEB %d: "
			  "free %d, dirty %d", lnum, free, dirty);
		goto out_destroy;
	}

	if (lp->free + lp->dirty == c->leb_size &&
	    free + dirty == c->leb_size)
		if ((is_idx && !(lp->flags & LPROPS_INDEX)) ||
		    (!is_idx && free == c->leb_size) ||
		    lp->free == c->leb_size) {
			/*
			 * Empty or freeable LEBs could contain index
			 * nodes from an uncompleted commit due to an
			 * unclean unmount. Or they could be empty for
			 * the same reason. Or it may simply not have been
			 * unmapped.
			 */
			free = lp->free;
			dirty = lp->dirty;
			is_idx = 0;
		    }

	if (is_idx && lp->free + lp->dirty == free + dirty &&
	    lnum != c->ihead_lnum) {
		/*
		 * After an unclean unmount, an index LEB could have a different
		 * amount of free space than the value recorded by lprops. That
		 * is because the in-the-gaps method may use free space or
		 * create free space (as a side-effect of using ubi_leb_change
		 * and not writing the whole LEB). The incorrect free space
		 * value is not a problem because the index is only ever
		 * allocated empty LEBs, so there will never be an attempt to
		 * write to the free space at the end of an index LEB - except
		 * by the in-the-gaps method for which it is not a problem.
		 */
		free = lp->free;
		dirty = lp->dirty;
	}

	if (lp->free != free || lp->dirty != dirty)
		goto out_print;

	if (is_idx && !(lp->flags & LPROPS_INDEX)) {
		if (free == c->leb_size)
			/* Free but not unmapped LEB, it's fine */
			is_idx = 0;
		else {
			ubifs_err("indexing node without indexing "
				  "flag");
			goto out_print;
		}
	}

	if (!is_idx && (lp->flags & LPROPS_INDEX)) {
		ubifs_err("data node with indexing flag");
		goto out_print;
	}

	if (free == c->leb_size)
		lst->empty_lebs += 1;

	if (is_idx)
		lst->idx_lebs += 1;

	if (!(lp->flags & LPROPS_INDEX))
		lst->total_used += c->leb_size - free - dirty;
	lst->total_free += free;
	lst->total_dirty += dirty;

	if (!(lp->flags & LPROPS_INDEX)) {
		int spc = free + dirty;

		if (spc < c->dead_wm)
			lst->total_dead += spc;
		else
			lst->total_dark += calc_dark(c, spc);
	}

	ubifs_scan_destroy(sleb);
	return LPT_SCAN_CONTINUE;

out_print:
	ubifs_err("bad accounting of LEB %d: free %d, dirty %d flags %#x, "
		  "should be free %d, dirty %d",
		  lnum, lp->free, lp->dirty, lp->flags, free, dirty);
	dbg_dump_leb(c, lnum);
out_destroy:
	ubifs_scan_destroy(sleb);
out:
	data->err = -EINVAL;
	return LPT_SCAN_STOP;
}

/**
 * dbg_check_lprops - check all LEB properties.
 * @c: UBIFS file-system description object
 *
 * This function checks all LEB properties and makes sure they are all correct.
 * It returns zero if everything is fine, %-EINVAL if there is an inconsistency
 * and other negative error codes in case of other errors. This function is
 * called while the file system is locked (because of commit start), so no
 * additional locking is required. Note that locking the LPT mutex would cause
 * a circular lock dependency with the TNC mutex.
 */
int dbg_check_lprops(struct ubifs_info *c)
{
	int i, err;
	struct scan_check_data data;
	struct ubifs_lp_stats *lst = &data.lst;

	if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
		return 0;

	/*
	 * As we are going to scan the media, the write buffers have to be
	 * synchronized.
	 */
	for (i = 0; i < c->jhead_cnt; i++) {
		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
		if (err)
			return err;
	}

	memset(lst, 0, sizeof(struct ubifs_lp_stats));

	data.err = 0;
	err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1,
				    (ubifs_lpt_scan_callback)scan_check_cb,
				    &data);
	if (err && err != -ENOSPC)
		goto out;
	if (data.err) {
		err = data.err;
		goto out;
	}

	if (lst->empty_lebs != c->lst.empty_lebs ||
	    lst->idx_lebs != c->lst.idx_lebs ||
	    lst->total_free != c->lst.total_free ||
	    lst->total_dirty != c->lst.total_dirty ||
	    lst->total_used != c->lst.total_used) {
		ubifs_err("bad overall accounting");
		ubifs_err("calculated: empty_lebs %d, idx_lebs %d, "
			  "total_free %lld, total_dirty %lld, total_used %lld",
			  lst->empty_lebs, lst->idx_lebs, lst->total_free,
			  lst->total_dirty, lst->total_used);
		ubifs_err("read from lprops: empty_lebs %d, idx_lebs %d, "
			  "total_free %lld, total_dirty %lld, total_used %lld",
			  c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free,
			  c->lst.total_dirty, c->lst.total_used);
		err = -EINVAL;
		goto out;
	}

	if (lst->total_dead != c->lst.total_dead ||
	    lst->total_dark != c->lst.total_dark) {
		ubifs_err("bad dead/dark space accounting");
		ubifs_err("calculated: total_dead %lld, total_dark %lld",
			  lst->total_dead, lst->total_dark);
		ubifs_err("read from lprops: total_dead %lld, total_dark %lld",
			  c->lst.total_dead, c->lst.total_dark);
		err = -EINVAL;
		goto out;
	}

	err = dbg_check_cats(c);
out:
	return err;
}

#endif /* CONFIG_UBIFS_FS_DEBUG */