summaryrefslogtreecommitdiffstats
path: root/fs/reiserfs/lbalance.c
blob: d48a9e7507a1d3cb05f31a44c98e017d5d93e2d1 (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
/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

#include <asm/uaccess.h>
#include <linux/string.h>
#include <linux/time.h>
#include "reiserfs.h"
#include <linux/buffer_head.h>

/*
 * copy copy_count entries from source directory item to dest buffer
 * (creating new item if needed)
 */
static void leaf_copy_dir_entries(struct buffer_info *dest_bi,
				  struct buffer_head *source, int last_first,
				  int item_num, int from, int copy_count)
{
	struct buffer_head *dest = dest_bi->bi_bh;
	/*
	 * either the number of target item, or if we must create a
	 * new item, the number of the item we will create it next to
	 */
	int item_num_in_dest;

	struct item_head *ih;
	struct reiserfs_de_head *deh;
	int copy_records_len;	/* length of all records in item to be copied */
	char *records;

	ih = item_head(source, item_num);

	RFALSE(!is_direntry_le_ih(ih), "vs-10000: item must be directory item");

	/*
	 * length of all record to be copied and first byte of
	 * the last of them
	 */
	deh = B_I_DEH(source, ih);
	if (copy_count) {
		copy_records_len = (from ? deh_location(&(deh[from - 1])) :
				    ih_item_len(ih)) -
		    deh_location(&(deh[from + copy_count - 1]));
		records =
		    source->b_data + ih_location(ih) +
		    deh_location(&(deh[from + copy_count - 1]));
	} else {
		copy_records_len = 0;
		records = NULL;
	}

	/* when copy last to first, dest buffer can contain 0 items */
	item_num_in_dest =
	    (last_first ==
	     LAST_TO_FIRST) ? ((B_NR_ITEMS(dest)) ? 0 : -1) : (B_NR_ITEMS(dest)
							       - 1);

	/*
	 * if there are no items in dest or the first/last item in
	 * dest is not item of the same directory
	 */
	if ((item_num_in_dest == -1) ||
	    (last_first == FIRST_TO_LAST && le_ih_k_offset(ih) == DOT_OFFSET) ||
	    (last_first == LAST_TO_FIRST
	     && comp_short_le_keys /*COMP_SHORT_KEYS */ (&ih->ih_key,
							 leaf_key(dest,
								  item_num_in_dest))))
	{
		/* create new item in dest */
		struct item_head new_ih;

		/* form item header */
		memcpy(&new_ih.ih_key, &ih->ih_key, KEY_SIZE);
		put_ih_version(&new_ih, KEY_FORMAT_3_5);
		/* calculate item len */
		put_ih_item_len(&new_ih,
				DEH_SIZE * copy_count + copy_records_len);
		put_ih_entry_count(&new_ih, 0);

		if (last_first == LAST_TO_FIRST) {
			/* form key by the following way */
			if (from < ih_entry_count(ih)) {
				set_le_ih_k_offset(&new_ih,
						   deh_offset(&(deh[from])));
			} else {
				/*
				 * no entries will be copied to this
				 * item in this function
				 */
				set_le_ih_k_offset(&new_ih, U32_MAX);
				/*
				 * this item is not yet valid, but we
				 * want I_IS_DIRECTORY_ITEM to return 1
				 * for it, so we -1
				 */
			}
			set_le_key_k_type(KEY_FORMAT_3_5, &(new_ih.ih_key),
					  TYPE_DIRENTRY);
		}

		/* insert item into dest buffer */
		leaf_insert_into_buf(dest_bi,
				     (last_first ==
				      LAST_TO_FIRST) ? 0 : B_NR_ITEMS(dest),
				     &new_ih, NULL, 0);
	} else {
		/* prepare space for entries */
		leaf_paste_in_buffer(dest_bi,
				     (last_first ==
				      FIRST_TO_LAST) ? (B_NR_ITEMS(dest) -
							1) : 0, MAX_US_INT,
				     DEH_SIZE * copy_count + copy_records_len,
				     records, 0);
	}

	item_num_in_dest =
	    (last_first == FIRST_TO_LAST) ? (B_NR_ITEMS(dest) - 1) : 0;

	leaf_paste_entries(dest_bi, item_num_in_dest,
			   (last_first ==
			    FIRST_TO_LAST) ? ih_entry_count(item_head(dest,
									  item_num_in_dest))
			   : 0, copy_count, deh + from, records,
			   DEH_SIZE * copy_count + copy_records_len);
}

/*
 * Copy the first (if last_first == FIRST_TO_LAST) or last
 * (last_first == LAST_TO_FIRST) item or part of it or nothing
 * (see the return 0 below) from SOURCE to the end (if last_first)
 * or beginning (!last_first) of the DEST
 */
/* returns 1 if anything was copied, else 0 */
static int leaf_copy_boundary_item(struct buffer_info *dest_bi,
				   struct buffer_head *src, int last_first,
				   int bytes_or_entries)
{
	struct buffer_head *dest = dest_bi->bi_bh;
	/* number of items in the source and destination buffers */
	int dest_nr_item, src_nr_item;
	struct item_head *ih;
	struct item_head *dih;

	dest_nr_item = B_NR_ITEMS(dest);

	/*
	 * if ( DEST is empty or first item of SOURCE and last item of
	 * DEST are the items of different objects or of different types )
	 * then there is no need to treat this item differently from the
	 * other items that we copy, so we return
	 */
	if (last_first == FIRST_TO_LAST) {
		ih = item_head(src, 0);
		dih = item_head(dest, dest_nr_item - 1);

		/* there is nothing to merge */
		if (!dest_nr_item
		    || (!op_is_left_mergeable(&(ih->ih_key), src->b_size)))
			return 0;

		RFALSE(!ih_item_len(ih),
		       "vs-10010: item can not have empty length");

		if (is_direntry_le_ih(ih)) {
			if (bytes_or_entries == -1)
				/* copy all entries to dest */
				bytes_or_entries = ih_entry_count(ih);
			leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST, 0, 0,
					      bytes_or_entries);
			return 1;
		}

		/*
		 * copy part of the body of the first item of SOURCE
		 * to the end of the body of the last item of the DEST
		 * part defined by 'bytes_or_entries'; if bytes_or_entries
		 * == -1 copy whole body; don't create new item header
		 */
		if (bytes_or_entries == -1)
			bytes_or_entries = ih_item_len(ih);

#ifdef CONFIG_REISERFS_CHECK
		else {
			if (bytes_or_entries == ih_item_len(ih)
			    && is_indirect_le_ih(ih))
				if (get_ih_free_space(ih))
					reiserfs_panic(sb_from_bi(dest_bi),
						       "vs-10020",
						       "last unformatted node "
						       "must be filled "
						       "entirely (%h)", ih);
		}
#endif

		/*
		 * merge first item (or its part) of src buffer with the last
		 * item of dest buffer. Both are of the same file
		 */
		leaf_paste_in_buffer(dest_bi,
				     dest_nr_item - 1, ih_item_len(dih),
				     bytes_or_entries, ih_item_body(src, ih), 0);

		if (is_indirect_le_ih(dih)) {
			RFALSE(get_ih_free_space(dih),
			       "vs-10030: merge to left: last unformatted node of non-last indirect item %h must have zerto free space",
			       ih);
			if (bytes_or_entries == ih_item_len(ih))
				set_ih_free_space(dih, get_ih_free_space(ih));
		}

		return 1;
	}

	/* copy boundary item to right (last_first == LAST_TO_FIRST) */

	/*
	 * (DEST is empty or last item of SOURCE and first item of DEST
	 * are the items of different object or of different types)
	 */
	src_nr_item = B_NR_ITEMS(src);
	ih = item_head(src, src_nr_item - 1);
	dih = item_head(dest, 0);

	if (!dest_nr_item || !op_is_left_mergeable(&(dih->ih_key), src->b_size))
		return 0;

	if (is_direntry_le_ih(ih)) {
		/*
		 * bytes_or_entries = entries number in last
		 * item body of SOURCE
		 */
		if (bytes_or_entries == -1)
			bytes_or_entries = ih_entry_count(ih);

		leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
				      src_nr_item - 1,
				      ih_entry_count(ih) - bytes_or_entries,
				      bytes_or_entries);
		return 1;
	}

	/*
	 * copy part of the body of the last item of SOURCE to the
	 * begin of the body of the first item of the DEST; part defined
	 * by 'bytes_or_entries'; if byte_or_entriess == -1 copy whole body;
	 * change first item key of the DEST; don't create new item header
	 */

	RFALSE(is_indirect_le_ih(ih) && get_ih_free_space(ih),
	       "vs-10040: merge to right: last unformatted node of non-last indirect item must be filled entirely (%h)",
	       ih);

	if (bytes_or_entries == -1) {
		/* bytes_or_entries = length of last item body of SOURCE */
		bytes_or_entries = ih_item_len(ih);

		RFALSE(le_ih_k_offset(dih) !=
		       le_ih_k_offset(ih) + op_bytes_number(ih, src->b_size),
		       "vs-10050: items %h and %h do not match", ih, dih);

		/* change first item key of the DEST */
		set_le_ih_k_offset(dih, le_ih_k_offset(ih));

		/* item becomes non-mergeable */
		/* or mergeable if left item was */
		set_le_ih_k_type(dih, le_ih_k_type(ih));
	} else {
		/* merge to right only part of item */
		RFALSE(ih_item_len(ih) <= bytes_or_entries,
		       "vs-10060: no so much bytes %lu (needed %lu)",
		       (unsigned long)ih_item_len(ih),
		       (unsigned long)bytes_or_entries);

		/* change first item key of the DEST */
		if (is_direct_le_ih(dih)) {
			RFALSE(le_ih_k_offset(dih) <=
			       (unsigned long)bytes_or_entries,
			       "vs-10070: dih %h, bytes_or_entries(%d)", dih,
			       bytes_or_entries);
			set_le_ih_k_offset(dih,
					   le_ih_k_offset(dih) -
					   bytes_or_entries);
		} else {
			RFALSE(le_ih_k_offset(dih) <=
			       (bytes_or_entries / UNFM_P_SIZE) * dest->b_size,
			       "vs-10080: dih %h, bytes_or_entries(%d)",
			       dih,
			       (bytes_or_entries / UNFM_P_SIZE) * dest->b_size);
			set_le_ih_k_offset(dih,
					   le_ih_k_offset(dih) -
					   ((bytes_or_entries / UNFM_P_SIZE) *
					    dest->b_size));
		}
	}

	leaf_paste_in_buffer(dest_bi, 0, 0, bytes_or_entries,
			     ih_item_body(src,
				       ih) + ih_item_len(ih) - bytes_or_entries,
			     0);
	return 1;
}

/*
 * copy cpy_mun items from buffer src to buffer dest
 * last_first == FIRST_TO_LAST means, that we copy cpy_num items beginning
 *                             from first-th item in src to tail of dest
 * last_first == LAST_TO_FIRST means, that we copy cpy_num items beginning
 *                             from first-th item in src to head of dest
 */
static void leaf_copy_items_entirely(struct buffer_info *dest_bi,
				     struct buffer_head *src, int last_first,
				     int first, int cpy_num)
{
	struct buffer_head *dest;
	int nr, free_space;
	int dest_before;
	int last_loc, last_inserted_loc, location;
	int i, j;
	struct block_head *blkh;
	struct item_head *ih;

	RFALSE(last_first != LAST_TO_FIRST && last_first != FIRST_TO_LAST,
	       "vs-10090: bad last_first parameter %d", last_first);
	RFALSE(B_NR_ITEMS(src) - first < cpy_num,
	       "vs-10100: too few items in source %d, required %d from %d",
	       B_NR_ITEMS(src), cpy_num, first);
	RFALSE(cpy_num < 0, "vs-10110: can not copy negative amount of items");
	RFALSE(!dest_bi, "vs-10120: can not copy negative amount of items");

	dest = dest_bi->bi_bh;

	RFALSE(!dest, "vs-10130: can not copy negative amount of items");

	if (cpy_num == 0)
		return;

	blkh = B_BLK_HEAD(dest);
	nr = blkh_nr_item(blkh);
	free_space = blkh_free_space(blkh);

	/*
	 * we will insert items before 0-th or nr-th item in dest buffer.
	 * It depends of last_first parameter
	 */
	dest_before = (last_first == LAST_TO_FIRST) ? 0 : nr;

	/* location of head of first new item */
	ih = item_head(dest, dest_before);

	RFALSE(blkh_free_space(blkh) < cpy_num * IH_SIZE,
	       "vs-10140: not enough free space for headers %d (needed %d)",
	       B_FREE_SPACE(dest), cpy_num * IH_SIZE);

	/* prepare space for headers */
	memmove(ih + cpy_num, ih, (nr - dest_before) * IH_SIZE);

	/* copy item headers */
	memcpy(ih, item_head(src, first), cpy_num * IH_SIZE);

	free_space -= (IH_SIZE * cpy_num);
	set_blkh_free_space(blkh, free_space);

	/* location of unmovable item */
	j = location = (dest_before == 0) ? dest->b_size : ih_location(ih - 1);
	for (i = dest_before; i < nr + cpy_num; i++) {
		location -= ih_item_len(ih + i - dest_before);
		put_ih_location(ih + i - dest_before, location);
	}

	/* prepare space for items */
	last_loc = ih_location(&(ih[nr + cpy_num - 1 - dest_before]));
	last_inserted_loc = ih_location(&(ih[cpy_num - 1]));

	/* check free space */
	RFALSE(free_space < j - last_inserted_loc,
	       "vs-10150: not enough free space for items %d (needed %d)",
	       free_space, j - last_inserted_loc);

	memmove(dest->b_data + last_loc,
		dest->b_data + last_loc + j - last_inserted_loc,
		last_inserted_loc - last_loc);

	/* copy items */
	memcpy(dest->b_data + last_inserted_loc,
	       item_body(src, (first + cpy_num - 1)),
	       j - last_inserted_loc);

	/* sizes, item number */
	set_blkh_nr_item(blkh, nr + cpy_num);
	set_blkh_free_space(blkh, free_space - (j - last_inserted_loc));

	do_balance_mark_leaf_dirty(dest_bi->tb, dest, 0);

	if (dest_bi->bi_parent) {
		struct disk_child *t_dc;
		t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
		RFALSE(dc_block_number(t_dc) != dest->b_blocknr,
		       "vs-10160: block number in bh does not match to field in disk_child structure %lu and %lu",
		       (long unsigned)dest->b_blocknr,
		       (long unsigned)dc_block_number(t_dc));
		put_dc_size(t_dc,
			    dc_size(t_dc) + (j - last_inserted_loc +
					     IH_SIZE * cpy_num));

		do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
					       0);
	}
}

/*
 * This function splits the (liquid) item into two items (useful when
 * shifting part of an item into another node.)
 */
static void leaf_item_bottle(struct buffer_info *dest_bi,
			     struct buffer_head *src, int last_first,
			     int item_num, int cpy_bytes)
{
	struct buffer_head *dest = dest_bi->bi_bh;
	struct item_head *ih;

	RFALSE(cpy_bytes == -1,
	       "vs-10170: bytes == - 1 means: do not split item");

	if (last_first == FIRST_TO_LAST) {
		/*
		 * if ( if item in position item_num in buffer SOURCE
		 * is directory item )
		 */
		ih = item_head(src, item_num);
		if (is_direntry_le_ih(ih))
			leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST,
					      item_num, 0, cpy_bytes);
		else {
			struct item_head n_ih;

			/*
			 * copy part of the body of the item number 'item_num'
			 * of SOURCE to the end of the DEST part defined by
			 * 'cpy_bytes'; create new item header; change old
			 * item_header (????); n_ih = new item_header;
			 */
			memcpy(&n_ih, ih, IH_SIZE);
			put_ih_item_len(&n_ih, cpy_bytes);
			if (is_indirect_le_ih(ih)) {
				RFALSE(cpy_bytes == ih_item_len(ih)
				       && get_ih_free_space(ih),
				       "vs-10180: when whole indirect item is bottle to left neighbor, it must have free_space==0 (not %lu)",
				       (long unsigned)get_ih_free_space(ih));
				set_ih_free_space(&n_ih, 0);
			}

			RFALSE(op_is_left_mergeable(&(ih->ih_key), src->b_size),
			       "vs-10190: bad mergeability of item %h", ih);
			n_ih.ih_version = ih->ih_version;	/* JDM Endian safe, both le */
			leaf_insert_into_buf(dest_bi, B_NR_ITEMS(dest), &n_ih,
					     item_body(src, item_num), 0);
		}
	} else {
		/*
		 * if ( if item in position item_num in buffer
		 * SOURCE is directory item )
		 */
		ih = item_head(src, item_num);
		if (is_direntry_le_ih(ih))
			leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
					      item_num,
					      ih_entry_count(ih) - cpy_bytes,
					      cpy_bytes);
		else {
			struct item_head n_ih;

			/*
			 * copy part of the body of the item number 'item_num'
			 * of SOURCE to the begin of the DEST part defined by
			 * 'cpy_bytes'; create new item header;
			 * n_ih = new item_header;
			 */
			memcpy(&n_ih, ih, SHORT_KEY_SIZE);

			/* Endian safe, both le */
			n_ih.ih_version = ih->ih_version;

			if (is_direct_le_ih(ih)) {
				set_le_ih_k_offset(&n_ih,
						   le_ih_k_offset(ih) +
						   ih_item_len(ih) - cpy_bytes);
				set_le_ih_k_type(&n_ih, TYPE_DIRECT);
				set_ih_free_space(&n_ih, MAX_US_INT);
			} else {
				/* indirect item */
				RFALSE(!cpy_bytes && get_ih_free_space(ih),
				       "vs-10200: ih->ih_free_space must be 0 when indirect item will be appended");
				set_le_ih_k_offset(&n_ih,
						   le_ih_k_offset(ih) +
						   (ih_item_len(ih) -
						    cpy_bytes) / UNFM_P_SIZE *
						   dest->b_size);
				set_le_ih_k_type(&n_ih, TYPE_INDIRECT);
				set_ih_free_space(&n_ih, get_ih_free_space(ih));
			}

			/* set item length */
			put_ih_item_len(&n_ih, cpy_bytes);

			/* Endian safe, both le */
			n_ih.ih_version = ih->ih_version;

			leaf_insert_into_buf(dest_bi, 0, &n_ih,
					     item_body(src, item_num) +
						ih_item_len(ih) - cpy_bytes, 0);
		}
	}
}

/*
 * If cpy_bytes equals minus one than copy cpy_num whole items from SOURCE
 * to DEST.  If cpy_bytes not equal to minus one than copy cpy_num-1 whole
 * items from SOURCE to DEST.  From last item copy cpy_num bytes for regular
 * item and cpy_num directory entries for directory item.
 */
static int leaf_copy_items(struct buffer_info *dest_bi, struct buffer_head *src,
			   int last_first, int cpy_num, int cpy_bytes)
{
	struct buffer_head *dest;
	int pos, i, src_nr_item, bytes;

	dest = dest_bi->bi_bh;
	RFALSE(!dest || !src, "vs-10210: !dest || !src");
	RFALSE(last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST,
	       "vs-10220:last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST");
	RFALSE(B_NR_ITEMS(src) < cpy_num,
	       "vs-10230: No enough items: %d, req. %d", B_NR_ITEMS(src),
	       cpy_num);
	RFALSE(cpy_num < 0, "vs-10240: cpy_num < 0 (%d)", cpy_num);

	if (cpy_num == 0)
		return 0;

	if (last_first == FIRST_TO_LAST) {
		/* copy items to left */
		pos = 0;
		if (cpy_num == 1)
			bytes = cpy_bytes;
		else
			bytes = -1;

		/*
		 * copy the first item or it part or nothing to the end of
		 * the DEST (i = leaf_copy_boundary_item(DEST,SOURCE,0,bytes))
		 */
		i = leaf_copy_boundary_item(dest_bi, src, FIRST_TO_LAST, bytes);
		cpy_num -= i;
		if (cpy_num == 0)
			return i;
		pos += i;
		if (cpy_bytes == -1)
			/*
			 * copy first cpy_num items starting from position
			 * 'pos' of SOURCE to end of DEST
			 */
			leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
						 pos, cpy_num);
		else {
			/*
			 * copy first cpy_num-1 items starting from position
			 * 'pos-1' of the SOURCE to the end of the DEST
			 */
			leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
						 pos, cpy_num - 1);

			/*
			 * copy part of the item which number is
			 * cpy_num+pos-1 to the end of the DEST
			 */
			leaf_item_bottle(dest_bi, src, FIRST_TO_LAST,
					 cpy_num + pos - 1, cpy_bytes);
		}
	} else {
		/* copy items to right */
		src_nr_item = B_NR_ITEMS(src);
		if (cpy_num == 1)
			bytes = cpy_bytes;
		else
			bytes = -1;

		/*
		 * copy the last item or it part or nothing to the
		 * begin of the DEST
		 * (i = leaf_copy_boundary_item(DEST,SOURCE,1,bytes));
		 */
		i = leaf_copy_boundary_item(dest_bi, src, LAST_TO_FIRST, bytes);

		cpy_num -= i;
		if (cpy_num == 0)
			return i;

		pos = src_nr_item - cpy_num - i;
		if (cpy_bytes == -1) {
			/*
			 * starting from position 'pos' copy last cpy_num
			 * items of SOURCE to begin of DEST
			 */
			leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
						 pos, cpy_num);
		} else {
			/*
			 * copy last cpy_num-1 items starting from position
			 * 'pos+1' of the SOURCE to the begin of the DEST;
			 */
			leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
						 pos + 1, cpy_num - 1);

			/*
			 * copy part of the item which number is pos to
			 * the begin of the DEST
			 */
			leaf_item_bottle(dest_bi, src, LAST_TO_FIRST, pos,
					 cpy_bytes);
		}
	}
	return i;
}

/*
 * there are types of coping: from S[0] to L[0], from S[0] to R[0],
 * from R[0] to L[0]. for each of these we have to define parent and
 * positions of destination and source buffers
 */
static void leaf_define_dest_src_infos(int shift_mode, struct tree_balance *tb,
				       struct buffer_info *dest_bi,
				       struct buffer_info *src_bi,
				       int *first_last,
				       struct buffer_head *Snew)
{
	memset(dest_bi, 0, sizeof(struct buffer_info));
	memset(src_bi, 0, sizeof(struct buffer_info));

	/* define dest, src, dest parent, dest position */
	switch (shift_mode) {
	case LEAF_FROM_S_TO_L:	/* it is used in leaf_shift_left */
		src_bi->tb = tb;
		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);

		/* src->b_item_order */
		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
		dest_bi->tb = tb;
		dest_bi->bi_bh = tb->L[0];
		dest_bi->bi_parent = tb->FL[0];
		dest_bi->bi_position = get_left_neighbor_position(tb, 0);
		*first_last = FIRST_TO_LAST;
		break;

	case LEAF_FROM_S_TO_R:	/* it is used in leaf_shift_right */
		src_bi->tb = tb;
		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
		dest_bi->tb = tb;
		dest_bi->bi_bh = tb->R[0];
		dest_bi->bi_parent = tb->FR[0];
		dest_bi->bi_position = get_right_neighbor_position(tb, 0);
		*first_last = LAST_TO_FIRST;
		break;

	case LEAF_FROM_R_TO_L:	/* it is used in balance_leaf_when_delete */
		src_bi->tb = tb;
		src_bi->bi_bh = tb->R[0];
		src_bi->bi_parent = tb->FR[0];
		src_bi->bi_position = get_right_neighbor_position(tb, 0);
		dest_bi->tb = tb;
		dest_bi->bi_bh = tb->L[0];
		dest_bi->bi_parent = tb->FL[0];
		dest_bi->bi_position = get_left_neighbor_position(tb, 0);
		*first_last = FIRST_TO_LAST;
		break;

	case LEAF_FROM_L_TO_R:	/* it is used in balance_leaf_when_delete */
		src_bi->tb = tb;
		src_bi->bi_bh = tb->L[0];
		src_bi->bi_parent = tb->FL[0];
		src_bi->bi_position = get_left_neighbor_position(tb, 0);
		dest_bi->tb = tb;
		dest_bi->bi_bh = tb->R[0];
		dest_bi->bi_parent = tb->FR[0];
		dest_bi->bi_position = get_right_neighbor_position(tb, 0);
		*first_last = LAST_TO_FIRST;
		break;

	case LEAF_FROM_S_TO_SNEW:
		src_bi->tb = tb;
		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
		dest_bi->tb = tb;
		dest_bi->bi_bh = Snew;
		dest_bi->bi_parent = NULL;
		dest_bi->bi_position = 0;
		*first_last = LAST_TO_FIRST;
		break;

	default:
		reiserfs_panic(sb_from_bi(src_bi), "vs-10250",
			       "shift type is unknown (%d)", shift_mode);
	}
	RFALSE(!src_bi->bi_bh || !dest_bi->bi_bh,
	       "vs-10260: mode==%d, source (%p) or dest (%p) buffer is initialized incorrectly",
	       shift_mode, src_bi->bi_bh, dest_bi->bi_bh);
}

/*
 * copy mov_num items and mov_bytes of the (mov_num-1)th item to
 * neighbor. Delete them from source
 */
int leaf_move_items(int shift_mode, struct tree_balance *tb, int mov_num,
		    int mov_bytes, struct buffer_head *Snew)
{
	int ret_value;
	struct buffer_info dest_bi, src_bi;
	int first_last;

	leaf_define_dest_src_infos(shift_mode, tb, &dest_bi, &src_bi,
				   &first_last, Snew);

	ret_value =
	    leaf_copy_items(&dest_bi, src_bi.bi_bh, first_last, mov_num,
			    mov_bytes);

	leaf_delete_items(&src_bi, first_last,
			  (first_last ==
			   FIRST_TO_LAST) ? 0 : (B_NR_ITEMS(src_bi.bi_bh) -
						 mov_num), mov_num, mov_bytes);

	return ret_value;
}

/*
 * Shift shift_num items (and shift_bytes of last shifted item if
 * shift_bytes != -1) from S[0] to L[0] and replace the delimiting key
 */
int leaf_shift_left(struct tree_balance *tb, int shift_num, int shift_bytes)
{
	struct buffer_head *S0 = PATH_PLAST_BUFFER(tb->tb_path);
	int i;

	/*
	 * move shift_num (and shift_bytes bytes) items from S[0]
	 * to left neighbor L[0]
	 */
	i = leaf_move_items(LEAF_FROM_S_TO_L, tb, shift_num, shift_bytes, NULL);

	if (shift_num) {
		/* number of items in S[0] == 0 */
		if (B_NR_ITEMS(S0) == 0) {

			RFALSE(shift_bytes != -1,
			       "vs-10270: S0 is empty now, but shift_bytes != -1 (%d)",
			       shift_bytes);
#ifdef CONFIG_REISERFS_CHECK
			if (tb->tb_mode == M_PASTE || tb->tb_mode == M_INSERT) {
				print_cur_tb("vs-10275");
				reiserfs_panic(tb->tb_sb, "vs-10275",
					       "balance condition corrupted "
					       "(%c)", tb->tb_mode);
			}
#endif

			if (PATH_H_POSITION(tb->tb_path, 1) == 0)
				replace_key(tb, tb->CFL[0], tb->lkey[0],
					    PATH_H_PPARENT(tb->tb_path, 0), 0);

		} else {
			/* replace lkey in CFL[0] by 0-th key from S[0]; */
			replace_key(tb, tb->CFL[0], tb->lkey[0], S0, 0);

			RFALSE((shift_bytes != -1 &&
				!(is_direntry_le_ih(item_head(S0, 0))
				  && !ih_entry_count(item_head(S0, 0)))) &&
			       (!op_is_left_mergeable
				(leaf_key(S0, 0), S0->b_size)),
			       "vs-10280: item must be mergeable");
		}
	}

	return i;
}

/* CLEANING STOPPED HERE */

/*
 * Shift shift_num (shift_bytes) items from S[0] to the right neighbor,
 * and replace the delimiting key
 */
int leaf_shift_right(struct tree_balance *tb, int shift_num, int shift_bytes)
{
	int ret_value;

	/*
	 * move shift_num (and shift_bytes) items from S[0] to
	 * right neighbor R[0]
	 */
	ret_value =
	    leaf_move_items(LEAF_FROM_S_TO_R, tb, shift_num, shift_bytes, NULL);

	/* replace rkey in CFR[0] by the 0-th key from R[0] */
	if (shift_num) {
		replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);

	}

	return ret_value;
}

static void leaf_delete_items_entirely(struct buffer_info *bi,
				       int first, int del_num);
/*
 * If del_bytes == -1, starting from position 'first' delete del_num
 * items in whole in buffer CUR.
 *   If not.
 *   If last_first == 0. Starting from position 'first' delete del_num-1
 *   items in whole. Delete part of body of the first item. Part defined by
 *   del_bytes. Don't delete first item header
 *   If last_first == 1. Starting from position 'first+1' delete del_num-1
 *   items in whole. Delete part of body of the last item . Part defined by
 *   del_bytes. Don't delete last item header.
*/
void leaf_delete_items(struct buffer_info *cur_bi, int last_first,
		       int first, int del_num, int del_bytes)
{
	struct buffer_head *bh;
	int item_amount = B_NR_ITEMS(bh = cur_bi->bi_bh);

	RFALSE(!bh, "10155: bh is not defined");
	RFALSE(del_num < 0, "10160: del_num can not be < 0. del_num==%d",
	       del_num);
	RFALSE(first < 0
	       || first + del_num > item_amount,
	       "10165: invalid number of first item to be deleted (%d) or "
	       "no so much items (%d) to delete (only %d)", first,
	       first + del_num, item_amount);

	if (del_num == 0)
		return;

	if (first == 0 && del_num == item_amount && del_bytes == -1) {
		make_empty_node(cur_bi);
		do_balance_mark_leaf_dirty(cur_bi->tb, bh, 0);
		return;
	}

	if (del_bytes == -1)
		/* delete del_num items beginning from item in position first */
		leaf_delete_items_entirely(cur_bi, first, del_num);
	else {
		if (last_first == FIRST_TO_LAST) {
			/*
			 * delete del_num-1 items beginning from
			 * item in position first
			 */
			leaf_delete_items_entirely(cur_bi, first, del_num - 1);

			/*
			 * delete the part of the first item of the bh
			 * do not delete item header
			 */
			leaf_cut_from_buffer(cur_bi, 0, 0, del_bytes);
		} else {
			struct item_head *ih;
			int len;

			/*
			 * delete del_num-1 items beginning from
			 * item in position first+1
			 */
			leaf_delete_items_entirely(cur_bi, first + 1,
						   del_num - 1);

			ih = item_head(bh, B_NR_ITEMS(bh) - 1);
			if (is_direntry_le_ih(ih))
				/* the last item is directory  */
				/*
				 * len = numbers of directory entries
				 * in this item
				 */
				len = ih_entry_count(ih);
			else
				/* len = body len of item */
				len = ih_item_len(ih);

			/*
			 * delete the part of the last item of the bh
			 * do not delete item header
			 */
			leaf_cut_from_buffer(cur_bi, B_NR_ITEMS(bh) - 1,
					     len - del_bytes, del_bytes);
		}
	}
}

/* insert item into the leaf node in position before */
void leaf_insert_into_buf(struct buffer_info *bi, int before,
			  struct item_head *inserted_item_ih,
			  const char *inserted_item_body, int zeros_number)
{
	struct buffer_head *bh = bi->bi_bh;
	int nr, free_space;
	struct block_head *blkh;
	struct item_head *ih;
	int i;
	int last_loc, unmoved_loc;
	char *to;

	blkh = B_BLK_HEAD(bh);
	nr = blkh_nr_item(blkh);
	free_space = blkh_free_space(blkh);

	/* check free space */
	RFALSE(free_space < ih_item_len(inserted_item_ih) + IH_SIZE,
	       "vs-10170: not enough free space in block %z, new item %h",
	       bh, inserted_item_ih);
	RFALSE(zeros_number > ih_item_len(inserted_item_ih),
	       "vs-10172: zero number == %d, item length == %d",
	       zeros_number, ih_item_len(inserted_item_ih));

	/* get item new item must be inserted before */
	ih = item_head(bh, before);

	/* prepare space for the body of new item */
	last_loc = nr ? ih_location(&(ih[nr - before - 1])) : bh->b_size;
	unmoved_loc = before ? ih_location(ih - 1) : bh->b_size;

	memmove(bh->b_data + last_loc - ih_item_len(inserted_item_ih),
		bh->b_data + last_loc, unmoved_loc - last_loc);

	to = bh->b_data + unmoved_loc - ih_item_len(inserted_item_ih);
	memset(to, 0, zeros_number);
	to += zeros_number;

	/* copy body to prepared space */
	if (inserted_item_body)
		memmove(to, inserted_item_body,
			ih_item_len(inserted_item_ih) - zeros_number);
	else
		memset(to, '\0', ih_item_len(inserted_item_ih) - zeros_number);

	/* insert item header */
	memmove(ih + 1, ih, IH_SIZE * (nr - before));
	memmove(ih, inserted_item_ih, IH_SIZE);

	/* change locations */
	for (i = before; i < nr + 1; i++) {
		unmoved_loc -= ih_item_len(&(ih[i - before]));
		put_ih_location(&(ih[i - before]), unmoved_loc);
	}

	/* sizes, free space, item number */
	set_blkh_nr_item(blkh, blkh_nr_item(blkh) + 1);
	set_blkh_free_space(blkh,
			    free_space - (IH_SIZE +
					  ih_item_len(inserted_item_ih)));
	do_balance_mark_leaf_dirty(bi->tb, bh, 1);

	if (bi->bi_parent) {
		struct disk_child *t_dc;
		t_dc = B_N_CHILD(bi->bi_parent, bi->bi_position);
		put_dc_size(t_dc,
			    dc_size(t_dc) + (IH_SIZE +
					     ih_item_len(inserted_item_ih)));
		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
	}
}

/*
 * paste paste_size bytes to affected_item_num-th item.
 * When item is a directory, this only prepare space for new entries
 */
void leaf_paste_in_buffer(struct buffer_info *bi, int affected_item_num,
			  int pos_in_item, int paste_size,
			  const char *body, int zeros_number)
{
	struct buffer_head *bh = bi->bi_bh;
	int nr, free_space;
	struct block_head *blkh;
	struct item_head *ih;
	int i;
	int last_loc, unmoved_loc;

	blkh = B_BLK_HEAD(bh);
	nr = blkh_nr_item(blkh);
	free_space = blkh_free_space(blkh);

	/* check free space */
	RFALSE(free_space < paste_size,
	       "vs-10175: not enough free space: needed %d, available %d",
	       paste_size, free_space);

#ifdef CONFIG_REISERFS_CHECK
	if (zeros_number > paste_size) {
		struct super_block *sb = NULL;
		if (bi && bi->tb)
			sb = bi->tb->tb_sb;
		print_cur_tb("10177");
		reiserfs_panic(sb, "vs-10177",
			       "zeros_number == %d, paste_size == %d",
			       zeros_number, paste_size);
	}
#endif				/* CONFIG_REISERFS_CHECK */

	/* item to be appended */
	ih = item_head(bh, affected_item_num);

	last_loc = ih_location(&(ih[nr - affected_item_num - 1]));
	unmoved_loc = affected_item_num ? ih_location(ih - 1) : bh->b_size;

	/* prepare space */
	memmove(bh->b_data + last_loc - paste_size, bh->b_data + last_loc,
		unmoved_loc - last_loc);

	/* change locations */
	for (i = affected_item_num; i < nr; i++)
		put_ih_location(&(ih[i - affected_item_num]),
				ih_location(&(ih[i - affected_item_num])) -
				paste_size);

	if (body) {
		if (!is_direntry_le_ih(ih)) {
			if (!pos_in_item) {
				/* shift data to right */
				memmove(bh->b_data + ih_location(ih) +
					paste_size,
					bh->b_data + ih_location(ih),
					ih_item_len(ih));
				/* paste data in the head of item */
				memset(bh->b_data + ih_location(ih), 0,
				       zeros_number);
				memcpy(bh->b_data + ih_location(ih) +
				       zeros_number, body,
				       paste_size - zeros_number);
			} else {
				memset(bh->b_data + unmoved_loc - paste_size, 0,
				       zeros_number);
				memcpy(bh->b_data + unmoved_loc - paste_size +
				       zeros_number, body,
				       paste_size - zeros_number);
			}
		}
	} else
		memset(bh->b_data + unmoved_loc - paste_size, '\0', paste_size);

	put_ih_item_len(ih, ih_item_len(ih) + paste_size);

	/* change free space */
	set_blkh_free_space(blkh, free_space - paste_size);

	do_balance_mark_leaf_dirty(bi->tb, bh, 0);

	if (bi->bi_parent) {
		struct disk_child *t_dc =
		    B_N_CHILD(bi->bi_parent, bi->bi_position);
		put_dc_size(t_dc, dc_size(t_dc) + paste_size);
		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
	}
}

/*
 * cuts DEL_COUNT entries beginning from FROM-th entry. Directory item
 * does not have free space, so it moves DEHs and remaining records as
 * necessary. Return value is size of removed part of directory item
 * in bytes.
 */
static int leaf_cut_entries(struct buffer_head *bh,
			    struct item_head *ih, int from, int del_count)
{
	char *item;
	struct reiserfs_de_head *deh;
	int prev_record_offset;	/* offset of record, that is (from-1)th */
	char *prev_record;	/* */
	int cut_records_len;	/* length of all removed records */
	int i;

	/*
	 * make sure that item is directory and there are enough entries to
	 * remove
	 */
	RFALSE(!is_direntry_le_ih(ih), "10180: item is not directory item");
	RFALSE(ih_entry_count(ih) < from + del_count,
	       "10185: item contains not enough entries: entry_count = %d, from = %d, to delete = %d",
	       ih_entry_count(ih), from, del_count);

	if (del_count == 0)
		return 0;

	/* first byte of item */
	item = bh->b_data + ih_location(ih);

	/* entry head array */
	deh = B_I_DEH(bh, ih);

	/*
	 * first byte of remaining entries, those are BEFORE cut entries
	 * (prev_record) and length of all removed records (cut_records_len)
	 */
	prev_record_offset =
	    (from ? deh_location(&(deh[from - 1])) : ih_item_len(ih));
	cut_records_len = prev_record_offset /*from_record */  -
	    deh_location(&(deh[from + del_count - 1]));
	prev_record = item + prev_record_offset;

	/* adjust locations of remaining entries */
	for (i = ih_entry_count(ih) - 1; i > from + del_count - 1; i--)
		put_deh_location(&(deh[i]),
				 deh_location(&deh[i]) -
				 (DEH_SIZE * del_count));

	for (i = 0; i < from; i++)
		put_deh_location(&(deh[i]),
				 deh_location(&deh[i]) - (DEH_SIZE * del_count +
							  cut_records_len));

	put_ih_entry_count(ih, ih_entry_count(ih) - del_count);

	/* shift entry head array and entries those are AFTER removed entries */
	memmove((char *)(deh + from),
		deh + from + del_count,
		prev_record - cut_records_len - (char *)(deh + from +
							 del_count));

	/* shift records, those are BEFORE removed entries */
	memmove(prev_record - cut_records_len - DEH_SIZE * del_count,
		prev_record, item + ih_item_len(ih) - prev_record);

	return DEH_SIZE * del_count + cut_records_len;
}

/*
 * when cut item is part of regular file
 *      pos_in_item - first byte that must be cut
 *      cut_size - number of bytes to be cut beginning from pos_in_item
 *
 * when cut item is part of directory
 *      pos_in_item - number of first deleted entry
 *      cut_size - count of deleted entries
 */
void leaf_cut_from_buffer(struct buffer_info *bi, int cut_item_num,
			  int pos_in_item, int cut_size)
{
	int nr;
	struct buffer_head *bh = bi->bi_bh;
	struct block_head *blkh;
	struct item_head *ih;
	int last_loc, unmoved_loc;
	int i;

	blkh = B_BLK_HEAD(bh);
	nr = blkh_nr_item(blkh);

	/* item head of truncated item */
	ih = item_head(bh, cut_item_num);

	if (is_direntry_le_ih(ih)) {
		/* first cut entry () */
		cut_size = leaf_cut_entries(bh, ih, pos_in_item, cut_size);
		if (pos_in_item == 0) {
			/* change key */
			RFALSE(cut_item_num,
			       "when 0-th enrty of item is cut, that item must be first in the node, not %d-th",
			       cut_item_num);
			/* change item key by key of first entry in the item */
			set_le_ih_k_offset(ih, deh_offset(B_I_DEH(bh, ih)));
		}
	} else {
		/* item is direct or indirect */
		RFALSE(is_statdata_le_ih(ih), "10195: item is stat data");
		RFALSE(pos_in_item && pos_in_item + cut_size != ih_item_len(ih),
		       "10200: invalid offset (%lu) or trunc_size (%lu) or ih_item_len (%lu)",
		       (long unsigned)pos_in_item, (long unsigned)cut_size,
		       (long unsigned)ih_item_len(ih));

		/* shift item body to left if cut is from the head of item */
		if (pos_in_item == 0) {
			memmove(bh->b_data + ih_location(ih),
				bh->b_data + ih_location(ih) + cut_size,
				ih_item_len(ih) - cut_size);

			/* change key of item */
			if (is_direct_le_ih(ih))
				set_le_ih_k_offset(ih,
						   le_ih_k_offset(ih) +
						   cut_size);
			else {
				set_le_ih_k_offset(ih,
						   le_ih_k_offset(ih) +
						   (cut_size / UNFM_P_SIZE) *
						   bh->b_size);
				RFALSE(ih_item_len(ih) == cut_size
				       && get_ih_free_space(ih),
				       "10205: invalid ih_free_space (%h)", ih);
			}
		}
	}

	/* location of the last item */
	last_loc = ih_location(&(ih[nr - cut_item_num - 1]));

	/* location of the item, which is remaining at the same place */
	unmoved_loc = cut_item_num ? ih_location(ih - 1) : bh->b_size;

	/* shift */
	memmove(bh->b_data + last_loc + cut_size, bh->b_data + last_loc,
		unmoved_loc - last_loc - cut_size);

	/* change item length */
	put_ih_item_len(ih, ih_item_len(ih) - cut_size);

	if (is_indirect_le_ih(ih)) {
		if (pos_in_item)
			set_ih_free_space(ih, 0);
	}

	/* change locations */
	for (i = cut_item_num; i < nr; i++)
		put_ih_location(&(ih[i - cut_item_num]),
				ih_location(&ih[i - cut_item_num]) + cut_size);

	/* size, free space */
	set_blkh_free_space(blkh, blkh_free_space(blkh) + cut_size);

	do_balance_mark_leaf_dirty(bi->tb, bh, 0);

	if (bi->bi_parent) {
		struct disk_child *t_dc;
		t_dc = B_N_CHILD(bi->bi_parent, bi->bi_position);
		put_dc_size(t_dc, dc_size(t_dc) - cut_size);
		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
	}
}

/* delete del_num items from buffer starting from the first'th item */
static void leaf_delete_items_entirely(struct buffer_info *bi,
				       int first, int del_num)
{
	struct buffer_head *bh = bi->bi_bh;
	int nr;
	int i, j;
	int last_loc, last_removed_loc;
	struct block_head *blkh;
	struct item_head *ih;

	RFALSE(bh == NULL, "10210: buffer is 0");
	RFALSE(del_num < 0, "10215: del_num less than 0 (%d)", del_num);

	if (del_num == 0)
		return;

	blkh = B_BLK_HEAD(bh);
	nr = blkh_nr_item(blkh);

	RFALSE(first < 0 || first + del_num > nr,
	       "10220: first=%d, number=%d, there is %d items", first, del_num,
	       nr);

	if (first == 0 && del_num == nr) {
		/* this does not work */
		make_empty_node(bi);

		do_balance_mark_leaf_dirty(bi->tb, bh, 0);
		return;
	}

	ih = item_head(bh, first);

	/* location of unmovable item */
	j = (first == 0) ? bh->b_size : ih_location(ih - 1);

	/* delete items */
	last_loc = ih_location(&(ih[nr - 1 - first]));
	last_removed_loc = ih_location(&(ih[del_num - 1]));

	memmove(bh->b_data + last_loc + j - last_removed_loc,
		bh->b_data + last_loc, last_removed_loc - last_loc);

	/* delete item headers */
	memmove(ih, ih + del_num, (nr - first - del_num) * IH_SIZE);

	/* change item location */
	for (i = first; i < nr - del_num; i++)
		put_ih_location(&(ih[i - first]),
				ih_location(&(ih[i - first])) + (j -
								 last_removed_loc));

	/* sizes, item number */
	set_blkh_nr_item(blkh, blkh_nr_item(blkh) - del_num);
	set_blkh_free_space(blkh,
			    blkh_free_space(blkh) + (j - last_removed_loc +
						     IH_SIZE * del_num));

	do_balance_mark_leaf_dirty(bi->tb, bh, 0);

	if (bi->bi_parent) {
		struct disk_child *t_dc =
		    B_N_CHILD(bi->bi_parent, bi->bi_position);
		put_dc_size(t_dc,
			    dc_size(t_dc) - (j - last_removed_loc +
					     IH_SIZE * del_num));
		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
	}
}

/*
 * paste new_entry_count entries (new_dehs, records) into position
 * before to item_num-th item
 */
void leaf_paste_entries(struct buffer_info *bi,
			int item_num,
			int before,
			int new_entry_count,
			struct reiserfs_de_head *new_dehs,
			const char *records, int paste_size)
{
	struct item_head *ih;
	char *item;
	struct reiserfs_de_head *deh;
	char *insert_point;
	int i, old_entry_num;
	struct buffer_head *bh = bi->bi_bh;

	if (new_entry_count == 0)
		return;

	ih = item_head(bh, item_num);

	/*
	 * make sure, that item is directory, and there are enough
	 * records in it
	 */
	RFALSE(!is_direntry_le_ih(ih), "10225: item is not directory item");
	RFALSE(ih_entry_count(ih) < before,
	       "10230: there are no entry we paste entries before. entry_count = %d, before = %d",
	       ih_entry_count(ih), before);

	/* first byte of dest item */
	item = bh->b_data + ih_location(ih);

	/* entry head array */
	deh = B_I_DEH(bh, ih);

	/* new records will be pasted at this point */
	insert_point =
	    item +
	    (before ? deh_location(&(deh[before - 1]))
	     : (ih_item_len(ih) - paste_size));

	/* adjust locations of records that will be AFTER new records */
	for (i = ih_entry_count(ih) - 1; i >= before; i--)
		put_deh_location(&(deh[i]),
				 deh_location(&(deh[i])) +
				 (DEH_SIZE * new_entry_count));

	/* adjust locations of records that will be BEFORE new records */
	for (i = 0; i < before; i++)
		put_deh_location(&(deh[i]),
				 deh_location(&(deh[i])) + paste_size);

	old_entry_num = ih_entry_count(ih);
	put_ih_entry_count(ih, ih_entry_count(ih) + new_entry_count);

	/* prepare space for pasted records */
	memmove(insert_point + paste_size, insert_point,
		item + (ih_item_len(ih) - paste_size) - insert_point);

	/* copy new records */
	memcpy(insert_point + DEH_SIZE * new_entry_count, records,
	       paste_size - DEH_SIZE * new_entry_count);

	/* prepare space for new entry heads */
	deh += before;
	memmove((char *)(deh + new_entry_count), deh,
		insert_point - (char *)deh);

	/* copy new entry heads */
	deh = (struct reiserfs_de_head *)((char *)deh);
	memcpy(deh, new_dehs, DEH_SIZE * new_entry_count);

	/* set locations of new records */
	for (i = 0; i < new_entry_count; i++) {
		put_deh_location(&(deh[i]),
				 deh_location(&(deh[i])) +
				 (-deh_location
				  (&(new_dehs[new_entry_count - 1])) +
				  insert_point + DEH_SIZE * new_entry_count -
				  item));
	}

	/* change item key if necessary (when we paste before 0-th entry */
	if (!before) {
		set_le_ih_k_offset(ih, deh_offset(new_dehs));
	}
#ifdef CONFIG_REISERFS_CHECK
	{
		int prev, next;
		/* check record locations */
		deh = B_I_DEH(bh, ih);
		for (i = 0; i < ih_entry_count(ih); i++) {
			next =
			    (i <
			     ih_entry_count(ih) -
			     1) ? deh_location(&(deh[i + 1])) : 0;
			prev = (i != 0) ? deh_location(&(deh[i - 1])) : 0;

			if (prev && prev <= deh_location(&(deh[i])))
				reiserfs_error(sb_from_bi(bi), "vs-10240",
					       "directory item (%h) "
					       "corrupted (prev %a, "
					       "cur(%d) %a)",
					       ih, deh + i - 1, i, deh + i);
			if (next && next >= deh_location(&(deh[i])))
				reiserfs_error(sb_from_bi(bi), "vs-10250",
					       "directory item (%h) "
					       "corrupted (cur(%d) %a, "
					       "next %a)",
					       ih, i, deh + i, deh + i + 1);
		}
	}
#endif

}