do_balan.c 51.1 KB
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
/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

/* Now we have all buffers that must be used in balancing of the tree 	*/
/* Further calculations can not cause schedule(), and thus the buffer 	*/
/* tree will be stable until the balancing will be finished 		*/
/* balance the tree according to the analysis made before,		*/
/* and using buffers obtained after all above.				*/

/**
 ** balance_leaf_when_delete
 ** balance_leaf
 ** do_balance
 **
 **/

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

static inline void buffer_info_init_left(struct tree_balance *tb,
                                         struct buffer_info *bi)
{
	bi->tb          = tb;
	bi->bi_bh       = tb->L[0];
	bi->bi_parent   = tb->FL[0];
	bi->bi_position = get_left_neighbor_position(tb, 0);
}

static inline void buffer_info_init_right(struct tree_balance *tb,
                                          struct buffer_info *bi)
{
	bi->tb          = tb;
	bi->bi_bh       = tb->R[0];
	bi->bi_parent   = tb->FR[0];
	bi->bi_position = get_right_neighbor_position(tb, 0);
}

static inline void buffer_info_init_tbS0(struct tree_balance *tb,
                                         struct buffer_info *bi)
{
	bi->tb          = tb;
	bi->bi_bh        = PATH_PLAST_BUFFER(tb->tb_path);
	bi->bi_parent   = PATH_H_PPARENT(tb->tb_path, 0);
	bi->bi_position = PATH_H_POSITION(tb->tb_path, 1);
}

static inline void buffer_info_init_bh(struct tree_balance *tb,
                                       struct buffer_info *bi,
                                       struct buffer_head *bh)
{
	bi->tb          = tb;
	bi->bi_bh       = bh;
	bi->bi_parent   = NULL;
	bi->bi_position = 0;
}

inline void do_balance_mark_leaf_dirty(struct tree_balance *tb,
				       struct buffer_head *bh, int flag)
{
	journal_mark_dirty(tb->transaction_handle,
			   tb->transaction_handle->t_super, bh);
}

#define do_balance_mark_internal_dirty do_balance_mark_leaf_dirty
#define do_balance_mark_sb_dirty do_balance_mark_leaf_dirty

/* summary:
 if deleting something ( tb->insert_size[0] < 0 )
   return(balance_leaf_when_delete()); (flag d handled here)
 else
   if lnum is larger than 0 we put items into the left node
   if rnum is larger than 0 we put items into the right node
   if snum1 is larger than 0 we put items into the new node s1
   if snum2 is larger than 0 we put items into the new node s2
Note that all *num* count new items being created.

It would be easier to read balance_leaf() if each of these summary
lines was a separate procedure rather than being inlined.  I think
that there are many passages here and in balance_leaf_when_delete() in
which two calls to one procedure can replace two passages, and it
might save cache space and improve software maintenance costs to do so.

Vladimir made the perceptive comment that we should offload most of
the decision making in this function into fix_nodes/check_balance, and
then create some sort of structure in tb that says what actions should
be performed by do_balance.

-Hans */

/* Balance leaf node in case of delete or cut: insert_size[0] < 0
 *
 * lnum, rnum can have values >= -1
 *	-1 means that the neighbor must be joined with S
 *	 0 means that nothing should be done with the neighbor
 *	>0 means to shift entirely or partly the specified number of items to the neighbor
 */
static int balance_leaf_when_delete(struct tree_balance *tb, int flag)
{
	struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
	int item_pos = PATH_LAST_POSITION(tb->tb_path);
	int pos_in_item = tb->tb_path->pos_in_item;
	struct buffer_info bi;
	int n;
	struct item_head *ih;

	RFALSE(tb->FR[0] && B_LEVEL(tb->FR[0]) != DISK_LEAF_NODE_LEVEL + 1,
	       "vs- 12000: level: wrong FR %z", tb->FR[0]);
	RFALSE(tb->blknum[0] > 1,
	       "PAP-12005: tb->blknum == %d, can not be > 1", tb->blknum[0]);
	RFALSE(!tb->blknum[0] && !PATH_H_PPARENT(tb->tb_path, 0),
	       "PAP-12010: tree can not be empty");

	ih = B_N_PITEM_HEAD(tbS0, item_pos);
	buffer_info_init_tbS0(tb, &bi);

	/* Delete or truncate the item */

	switch (flag) {
	case M_DELETE:		/* delete item in S[0] */

		RFALSE(ih_item_len(ih) + IH_SIZE != -tb->insert_size[0],
		       "vs-12013: mode Delete, insert size %d, ih to be deleted %h",
		       -tb->insert_size[0], ih);

		leaf_delete_items(&bi, 0, item_pos, 1, -1);

		if (!item_pos && tb->CFL[0]) {
			if (B_NR_ITEMS(tbS0)) {
				replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0,
					    0);
			} else {
				if (!PATH_H_POSITION(tb->tb_path, 1))
					replace_key(tb, tb->CFL[0], tb->lkey[0],
						    PATH_H_PPARENT(tb->tb_path,
								   0), 0);
			}
		}

		RFALSE(!item_pos && !tb->CFL[0],
		       "PAP-12020: tb->CFL[0]==%p, tb->L[0]==%p", tb->CFL[0],
		       tb->L[0]);

		break;

	case M_CUT:{		/* cut item in S[0] */
			if (is_direntry_le_ih(ih)) {

				/* UFS unlink semantics are such that you can only delete one directory entry at a time. */
				/* when we cut a directory tb->insert_size[0] means number of entries to be cut (always 1) */
				tb->insert_size[0] = -1;
				leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
						     -tb->insert_size[0]);

				RFALSE(!item_pos && !pos_in_item && !tb->CFL[0],
				       "PAP-12030: can not change delimiting key. CFL[0]=%p",
				       tb->CFL[0]);

				if (!item_pos && !pos_in_item && tb->CFL[0]) {
					replace_key(tb, tb->CFL[0], tb->lkey[0],
						    tbS0, 0);
				}
			} else {
				leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
						     -tb->insert_size[0]);

				RFALSE(!ih_item_len(ih),
				       "PAP-12035: cut must leave non-zero dynamic length of item");
			}
			break;
		}

	default:
		print_cur_tb("12040");
		reiserfs_panic(tb->tb_sb, "PAP-12040",
			       "unexpected mode: %s(%d)",
			       (flag ==
				M_PASTE) ? "PASTE" : ((flag ==
						       M_INSERT) ? "INSERT" :
						      "UNKNOWN"), flag);
	}

	/* the rule is that no shifting occurs unless by shifting a node can be freed */
	n = B_NR_ITEMS(tbS0);
	if (tb->lnum[0]) {	/* L[0] takes part in balancing */
		if (tb->lnum[0] == -1) {	/* L[0] must be joined with S[0] */
			if (tb->rnum[0] == -1) {	/* R[0] must be also joined with S[0] */
				if (tb->FR[0] == PATH_H_PPARENT(tb->tb_path, 0)) {
					/* all contents of all the 3 buffers will be in L[0] */
					if (PATH_H_POSITION(tb->tb_path, 1) == 0
					    && 1 < B_NR_ITEMS(tb->FR[0]))
						replace_key(tb, tb->CFL[0],
							    tb->lkey[0],
							    tb->FR[0], 1);

					leaf_move_items(LEAF_FROM_S_TO_L, tb, n,
							-1, NULL);
					leaf_move_items(LEAF_FROM_R_TO_L, tb,
							B_NR_ITEMS(tb->R[0]),
							-1, NULL);

					reiserfs_invalidate_buffer(tb, tbS0);
					reiserfs_invalidate_buffer(tb,
								   tb->R[0]);

					return 0;
				}
				/* all contents of all the 3 buffers will be in R[0] */
				leaf_move_items(LEAF_FROM_S_TO_R, tb, n, -1,
						NULL);
				leaf_move_items(LEAF_FROM_L_TO_R, tb,
						B_NR_ITEMS(tb->L[0]), -1, NULL);

				/* right_delimiting_key is correct in R[0] */
				replace_key(tb, tb->CFR[0], tb->rkey[0],
					    tb->R[0], 0);

				reiserfs_invalidate_buffer(tb, tbS0);
				reiserfs_invalidate_buffer(tb, tb->L[0]);

				return -1;
			}

			RFALSE(tb->rnum[0] != 0,
			       "PAP-12045: rnum must be 0 (%d)", tb->rnum[0]);
			/* all contents of L[0] and S[0] will be in L[0] */
			leaf_shift_left(tb, n, -1);

			reiserfs_invalidate_buffer(tb, tbS0);

			return 0;
		}
		/* a part of contents of S[0] will be in L[0] and the rest part of S[0] will be in R[0] */

		RFALSE((tb->lnum[0] + tb->rnum[0] < n) ||
		       (tb->lnum[0] + tb->rnum[0] > n + 1),
		       "PAP-12050: rnum(%d) and lnum(%d) and item number(%d) in S[0] are not consistent",
		       tb->rnum[0], tb->lnum[0], n);
		RFALSE((tb->lnum[0] + tb->rnum[0] == n) &&
		       (tb->lbytes != -1 || tb->rbytes != -1),
		       "PAP-12055: bad rbytes (%d)/lbytes (%d) parameters when items are not split",
		       tb->rbytes, tb->lbytes);
		RFALSE((tb->lnum[0] + tb->rnum[0] == n + 1) &&
		       (tb->lbytes < 1 || tb->rbytes != -1),
		       "PAP-12060: bad rbytes (%d)/lbytes (%d) parameters when items are split",
		       tb->rbytes, tb->lbytes);

		leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
		leaf_shift_right(tb, tb->rnum[0], tb->rbytes);

		reiserfs_invalidate_buffer(tb, tbS0);

		return 0;
	}

	if (tb->rnum[0] == -1) {
		/* all contents of R[0] and S[0] will be in R[0] */
		leaf_shift_right(tb, n, -1);
		reiserfs_invalidate_buffer(tb, tbS0);
		return 0;
	}

	RFALSE(tb->rnum[0],
	       "PAP-12065: bad rnum parameter must be 0 (%d)", tb->rnum[0]);
	return 0;
}

static int balance_leaf(struct tree_balance *tb, struct item_head *ih,	/* item header of inserted item (this is on little endian) */
			const char *body,	/* body  of inserted item or bytes to paste */
			int flag,	/* i - insert, d - delete, c - cut, p - paste
					   (see comment to do_balance) */
			struct item_head *insert_key,	/* in our processing of one level we sometimes determine what
							   must be inserted into the next higher level.  This insertion
							   consists of a key or two keys and their corresponding
							   pointers */
			struct buffer_head **insert_ptr	/* inserted node-ptrs for the next level */
    )
{
	struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
	int item_pos = PATH_LAST_POSITION(tb->tb_path);	/*  index into the array of item headers in S[0]
							   of the affected item */
	struct buffer_info bi;
	struct buffer_head *S_new[2];	/* new nodes allocated to hold what could not fit into S */
	int snum[2];		/* number of items that will be placed
				   into S_new (includes partially shifted
				   items) */
	int sbytes[2];		/* if an item is partially shifted into S_new then
				   if it is a directory item
				   it is the number of entries from the item that are shifted into S_new
				   else
				   it is the number of bytes from the item that are shifted into S_new
				 */
	int n, i;
	int ret_val;
	int pos_in_item;
	int zeros_num;

	PROC_INFO_INC(tb->tb_sb, balance_at[0]);

	/* Make balance in case insert_size[0] < 0 */
	if (tb->insert_size[0] < 0)
		return balance_leaf_when_delete(tb, flag);

	zeros_num = 0;
	if (flag == M_INSERT && !body)
		zeros_num = ih_item_len(ih);

	pos_in_item = tb->tb_path->pos_in_item;
	/* for indirect item pos_in_item is measured in unformatted node
	   pointers. Recalculate to bytes */
	if (flag != M_INSERT
	    && is_indirect_le_ih(B_N_PITEM_HEAD(tbS0, item_pos)))
		pos_in_item *= UNFM_P_SIZE;

	if (tb->lnum[0] > 0) {
		/* Shift lnum[0] items from S[0] to the left neighbor L[0] */
		if (item_pos < tb->lnum[0]) {
			/* new item or it part falls to L[0], shift it too */
			n = B_NR_ITEMS(tb->L[0]);

			switch (flag) {
			case M_INSERT:	/* insert item into L[0] */

				if (item_pos == tb->lnum[0] - 1 && tb->lbytes != -1) {
					/* part of new item falls into L[0] */
					int new_item_len;
					int version;

					ret_val = leaf_shift_left(tb, tb->lnum[0] - 1, -1);

					/* Calculate item length to insert to S[0] */
					new_item_len = ih_item_len(ih) - tb->lbytes;
					/* Calculate and check item length to insert to L[0] */
					put_ih_item_len(ih, ih_item_len(ih) - new_item_len);

					RFALSE(ih_item_len(ih) <= 0,
					       "PAP-12080: there is nothing to insert into L[0]: ih_item_len=%d",
					       ih_item_len(ih));

					/* Insert new item into L[0] */
					buffer_info_init_left(tb, &bi);
					leaf_insert_into_buf(&bi,
							n + item_pos - ret_val, ih, body,
							zeros_num > ih_item_len(ih) ? ih_item_len(ih) : zeros_num);

					version = ih_version(ih);

					/* Calculate key component, item length and body to insert into S[0] */
					set_le_ih_k_offset(ih, le_ih_k_offset(ih) +
							(tb-> lbytes << (is_indirect_le_ih(ih) ? tb->tb_sb-> s_blocksize_bits - UNFM_P_SHIFT : 0)));

					put_ih_item_len(ih, new_item_len);
					if (tb->lbytes > zeros_num) {
						body += (tb->lbytes - zeros_num);
						zeros_num = 0;
					} else
						zeros_num -= tb->lbytes;

					RFALSE(ih_item_len(ih) <= 0,
					       "PAP-12085: there is nothing to insert into S[0]: ih_item_len=%d",
					       ih_item_len(ih));
				} else {
					/* new item in whole falls into L[0] */
					/* Shift lnum[0]-1 items to L[0] */
					ret_val = leaf_shift_left(tb, tb->lnum[0] - 1, tb->lbytes);
					/* Insert new item into L[0] */
					buffer_info_init_left(tb, &bi);
					leaf_insert_into_buf(&bi, n + item_pos - ret_val, ih, body, zeros_num);
					tb->insert_size[0] = 0;
					zeros_num = 0;
				}
				break;

			case M_PASTE:	/* append item in L[0] */

				if (item_pos == tb->lnum[0] - 1 && tb->lbytes != -1) {
					/* we must shift the part of the appended item */
					if (is_direntry_le_ih(B_N_PITEM_HEAD(tbS0, item_pos))) {

						RFALSE(zeros_num,
						       "PAP-12090: invalid parameter in case of a directory");
						/* directory item */
						if (tb->lbytes > pos_in_item) {
							/* new directory entry falls into L[0] */
							struct item_head *pasted;
							int l_pos_in_item = pos_in_item;

							/* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 entries from given directory item */
							ret_val = leaf_shift_left(tb, tb->lnum[0], tb->lbytes-1);
							if (ret_val && !item_pos) {
								pasted = B_N_PITEM_HEAD(tb->L[0], B_NR_ITEMS(tb->L[0]) - 1);
								l_pos_in_item += I_ENTRY_COUNT(pasted) - (tb->lbytes -1);
							}

							/* Append given directory entry to directory item */
							buffer_info_init_left(tb, &bi);
							leaf_paste_in_buffer(&bi, n + item_pos - ret_val, l_pos_in_item, tb->insert_size[0], body, zeros_num);

							/* previous string prepared space for pasting new entry, following string pastes this entry */

							/* when we have merge directory item, pos_in_item has been changed too */

							/* paste new directory entry. 1 is entry number */
							leaf_paste_entries(&bi, n + item_pos - ret_val, l_pos_in_item,
									   1, (struct reiserfs_de_head *) body,
									   body + DEH_SIZE, tb->insert_size[0]);
							tb->insert_size[0] = 0;
						} else {
							/* new directory item doesn't fall into L[0] */
							/* Shift lnum[0]-1 items in whole. Shift lbytes directory entries from directory item number lnum[0] */
							leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
						}
						/* Calculate new position to append in item body */
						pos_in_item -= tb->lbytes;
					} else {
						/* regular object */
						RFALSE(tb->lbytes <= 0, "PAP-12095: there is nothing to shift to L[0]. lbytes=%d", tb->lbytes);
						RFALSE(pos_in_item != ih_item_len(B_N_PITEM_HEAD(tbS0, item_pos)),
						       "PAP-12100: incorrect position to paste: item_len=%d, pos_in_item=%d",
						       ih_item_len(B_N_PITEM_HEAD(tbS0, item_pos)),pos_in_item);

						if (tb->lbytes >= pos_in_item) {
							/* appended item will be in L[0] in whole */
							int l_n;

							/* this bytes number must be appended to the last item of L[h] */
							l_n = tb->lbytes - pos_in_item;

							/* Calculate new insert_size[0] */
							tb->insert_size[0] -= l_n;

							RFALSE(tb->insert_size[0] <= 0,
							       "PAP-12105: there is nothing to paste into L[0]. insert_size=%d",
							       tb->insert_size[0]);
							ret_val = leaf_shift_left(tb, tb->lnum[0], ih_item_len
									    (B_N_PITEM_HEAD(tbS0, item_pos)));
							/* Append to body of item in L[0] */
							buffer_info_init_left(tb, &bi);
							leaf_paste_in_buffer
							    (&bi, n + item_pos - ret_val, ih_item_len
							     (B_N_PITEM_HEAD(tb->L[0], n + item_pos - ret_val)),
							     l_n, body,
							     zeros_num > l_n ? l_n : zeros_num);
							/* 0-th item in S0 can be only of DIRECT type when l_n != 0 */
							{
								int version;
								int temp_l = l_n;

								RFALSE(ih_item_len(B_N_PITEM_HEAD(tbS0, 0)),
								     "PAP-12106: item length must be 0");
								RFALSE(comp_short_le_keys(B_N_PKEY(tbS0, 0), B_N_PKEY
								      (tb->L[0], n + item_pos - ret_val)),
								     "PAP-12107: items must be of the same file");
								if (is_indirect_le_ih(B_N_PITEM_HEAD(tb->L[0], n + item_pos - ret_val))) {
									temp_l = l_n << (tb->tb_sb-> s_blocksize_bits - UNFM_P_SHIFT);
								}
								/* update key of first item in S0 */
								version = ih_version(B_N_PITEM_HEAD(tbS0, 0));
								set_le_key_k_offset(version, B_N_PKEY(tbS0, 0),
								     le_key_k_offset(version,B_N_PKEY(tbS0, 0)) + temp_l);
								/* update left delimiting key */
								set_le_key_k_offset(version, B_N_PDELIM_KEY(tb->CFL[0], tb->lkey[0]),
								     le_key_k_offset(version, B_N_PDELIM_KEY(tb->CFL[0], tb->lkey[0])) + temp_l);
							}

							/* Calculate new body, position in item and insert_size[0] */
							if (l_n > zeros_num) {
								body += (l_n - zeros_num);
								zeros_num = 0;
							} else
								zeros_num -= l_n;
							pos_in_item = 0;

							RFALSE(comp_short_le_keys(B_N_PKEY(tbS0, 0), B_N_PKEY(tb->L[0], B_NR_ITEMS(tb->L[0]) - 1))
							     || !op_is_left_mergeable(B_N_PKEY(tbS0, 0), tbS0->b_size)
							     || !op_is_left_mergeable(B_N_PDELIM_KEY(tb->CFL[0], tb->lkey[0]), tbS0->b_size),
							     "PAP-12120: item must be merge-able with left neighboring item");
						} else {	/* only part of the appended item will be in L[0] */

							/* Calculate position in item for append in S[0] */
							pos_in_item -= tb->lbytes;

							RFALSE(pos_in_item <= 0, "PAP-12125: no place for paste. pos_in_item=%d", pos_in_item);

							/* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 byte from item number lnum[0] */
							leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
						}
					}
				} else {	/* appended item will be in L[0] in whole */

					struct item_head *pasted;

					if (!item_pos && op_is_left_mergeable(B_N_PKEY(tbS0, 0), tbS0->b_size)) {	/* if we paste into first item of S[0] and it is left mergable */
						/* then increment pos_in_item by the size of the last item in L[0] */
						pasted = B_N_PITEM_HEAD(tb->L[0], n - 1);
						if (is_direntry_le_ih(pasted))
							pos_in_item += ih_entry_count(pasted);
						else
							pos_in_item += ih_item_len(pasted);
					}

					/* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 byte from item number lnum[0] */
					ret_val = leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
					/* Append to body of item in L[0] */
					buffer_info_init_left(tb, &bi);
					leaf_paste_in_buffer(&bi, n + item_pos - ret_val,
							     pos_in_item,
							     tb->insert_size[0],
							     body, zeros_num);

					/* if appended item is directory, paste entry */
					pasted = B_N_PITEM_HEAD(tb->L[0], n + item_pos - ret_val);
					if (is_direntry_le_ih(pasted))
						leaf_paste_entries(&bi, n + item_pos - ret_val,
								   pos_in_item, 1,
								   (struct reiserfs_de_head *) body,
								   body + DEH_SIZE,
								   tb->insert_size[0]);
					/* if appended item is indirect item, put unformatted node into un list */
					if (is_indirect_le_ih(pasted))
						set_ih_free_space(pasted, 0);
					tb->insert_size[0] = 0;
					zeros_num = 0;
				}
				break;
			default:	/* cases d and t */
				reiserfs_panic(tb->tb_sb, "PAP-12130",
					       "lnum > 0: unexpected mode: "
					       " %s(%d)",
					       (flag == M_DELETE) ? "DELETE" : ((flag == M_CUT) ? "CUT" : "UNKNOWN"), flag);
			}
		} else {
			/* new item doesn't fall into L[0] */
			leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
		}
	}

	/* tb->lnum[0] > 0 */
	/* Calculate new item position */
	item_pos -= (tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0));

	if (tb->rnum[0] > 0) {
		/* shift rnum[0] items from S[0] to the right neighbor R[0] */
		n = B_NR_ITEMS(tbS0);
		switch (flag) {

		case M_INSERT:	/* insert item */
			if (n - tb->rnum[0] < item_pos) {	/* new item or its part falls to R[0] */
				if (item_pos == n - tb->rnum[0] + 1 && tb->rbytes != -1) {	/* part of new item falls into R[0] */
					loff_t old_key_comp, old_len, r_zeros_number;
					const char *r_body;
					int version;
					loff_t offset;

					leaf_shift_right(tb, tb->rnum[0] - 1, -1);

					version = ih_version(ih);
					/* Remember key component and item length */
					old_key_comp = le_ih_k_offset(ih);
					old_len = ih_item_len(ih);

					/* Calculate key component and item length to insert into R[0] */
					offset = le_ih_k_offset(ih) + ((old_len - tb->rbytes) << (is_indirect_le_ih(ih) ? tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT : 0));
					set_le_ih_k_offset(ih, offset);
					put_ih_item_len(ih, tb->rbytes);
					/* Insert part of the item into R[0] */
					buffer_info_init_right(tb, &bi);
					if ((old_len - tb->rbytes) > zeros_num) {
						r_zeros_number = 0;
						r_body = body + (old_len - tb->rbytes) - zeros_num;
					} else {
						r_body = body;
						r_zeros_number = zeros_num - (old_len - tb->rbytes);
						zeros_num -= r_zeros_number;
					}

					leaf_insert_into_buf(&bi, 0, ih, r_body,
							     r_zeros_number);

					/* Replace right delimiting key by first key in R[0] */
					replace_key(tb, tb->CFR[0], tb->rkey[0],
						    tb->R[0], 0);

					/* Calculate key component and item length to insert into S[0] */
					set_le_ih_k_offset(ih, old_key_comp);
					put_ih_item_len(ih, old_len - tb->rbytes);

					tb->insert_size[0] -= tb->rbytes;

				} else {	/* whole new item falls into R[0] */

					/* Shift rnum[0]-1 items to R[0] */
					ret_val = leaf_shift_right(tb, tb->rnum[0] - 1, tb->rbytes);
					/* Insert new item into R[0] */
					buffer_info_init_right(tb, &bi);
					leaf_insert_into_buf(&bi, item_pos - n + tb->rnum[0] - 1,
							     ih, body, zeros_num);

					if (item_pos - n + tb->rnum[0] - 1 == 0) {
						replace_key(tb, tb->CFR[0],
							    tb->rkey[0],
							    tb->R[0], 0);

					}
					zeros_num = tb->insert_size[0] = 0;
				}
			} else {	/* new item or part of it doesn't fall into R[0] */

				leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
			}
			break;

		case M_PASTE:	/* append item */

			if (n - tb->rnum[0] <= item_pos) {	/* pasted item or part of it falls to R[0] */
				if (item_pos == n - tb->rnum[0] && tb->rbytes != -1) {	/* we must shift the part of the appended item */
					if (is_direntry_le_ih(B_N_PITEM_HEAD(tbS0, item_pos))) {	/* we append to directory item */
						int entry_count;

						RFALSE(zeros_num,
						       "PAP-12145: invalid parameter in case of a directory");
						entry_count = I_ENTRY_COUNT(B_N_PITEM_HEAD
								  (tbS0, item_pos));
						if (entry_count - tb->rbytes <
						    pos_in_item)
							/* new directory entry falls into R[0] */
						{
							int paste_entry_position;

							RFALSE(tb->rbytes - 1 >= entry_count || !tb-> insert_size[0],
							       "PAP-12150: no enough of entries to shift to R[0]: rbytes=%d, entry_count=%d",
							       tb->rbytes, entry_count);
							/* Shift rnum[0]-1 items in whole. Shift rbytes-1 directory entries from directory item number rnum[0] */
							leaf_shift_right(tb, tb->rnum[0], tb->rbytes - 1);
							/* Paste given directory entry to directory item */
							paste_entry_position = pos_in_item - entry_count + tb->rbytes - 1;
							buffer_info_init_right(tb, &bi);
							leaf_paste_in_buffer(&bi, 0, paste_entry_position, tb->insert_size[0], body, zeros_num);
							/* paste entry */
							leaf_paste_entries(&bi, 0, paste_entry_position, 1,
									   (struct reiserfs_de_head *) body,
									   body + DEH_SIZE, tb->insert_size[0]);

							if (paste_entry_position == 0) {
								/* change delimiting keys */
								replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0],0);
							}

							tb->insert_size[0] = 0;
							pos_in_item++;
						} else {	/* new directory entry doesn't fall into R[0] */

							leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
						}
					} else {	/* regular object */

						int n_shift, n_rem, r_zeros_number;
						const char *r_body;

						/* Calculate number of bytes which must be shifted from appended item */
						if ((n_shift = tb->rbytes - tb->insert_size[0]) < 0)
							n_shift = 0;

						RFALSE(pos_in_item != ih_item_len
						       (B_N_PITEM_HEAD(tbS0, item_pos)),
						       "PAP-12155: invalid position to paste. ih_item_len=%d, pos_in_item=%d",
						       pos_in_item, ih_item_len
						       (B_N_PITEM_HEAD(tbS0, item_pos)));

						leaf_shift_right(tb, tb->rnum[0], n_shift);
						/* Calculate number of bytes which must remain in body after appending to R[0] */
						if ((n_rem = tb->insert_size[0] - tb->rbytes) < 0)
							n_rem = 0;

						{
							int version;
							unsigned long temp_rem = n_rem;

							version = ih_version(B_N_PITEM_HEAD(tb->R[0], 0));
							if (is_indirect_le_key(version, B_N_PKEY(tb->R[0], 0))) {
								temp_rem = n_rem << (tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT);
							}
							set_le_key_k_offset(version, B_N_PKEY(tb->R[0], 0),
							     le_key_k_offset(version, B_N_PKEY(tb->R[0], 0)) + temp_rem);
							set_le_key_k_offset(version, B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0]),
							     le_key_k_offset(version, B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0])) + temp_rem);
						}
/*		  k_offset (B_N_PKEY(tb->R[0],0)) += n_rem;
		  k_offset (B_N_PDELIM_KEY(tb->CFR[0],tb->rkey[0])) += n_rem;*/
						do_balance_mark_internal_dirty(tb, tb->CFR[0], 0);

						/* Append part of body into R[0] */
						buffer_info_init_right(tb, &bi);
						if (n_rem > zeros_num) {
							r_zeros_number = 0;
							r_body = body + n_rem - zeros_num;
						} else {
							r_body = body;
							r_zeros_number = zeros_num - n_rem;
							zeros_num -= r_zeros_number;
						}

						leaf_paste_in_buffer(&bi, 0, n_shift,
								     tb->insert_size[0] - n_rem,
								     r_body, r_zeros_number);

						if (is_indirect_le_ih(B_N_PITEM_HEAD(tb->R[0], 0))) {
#if 0
							RFALSE(n_rem,
							       "PAP-12160: paste more than one unformatted node pointer");
#endif
							set_ih_free_space(B_N_PITEM_HEAD(tb->R[0], 0), 0);
						}
						tb->insert_size[0] = n_rem;
						if (!n_rem)
							pos_in_item++;
					}
				} else {	/* pasted item in whole falls into R[0] */

					struct item_head *pasted;

					ret_val = leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
					/* append item in R[0] */
					if (pos_in_item >= 0) {
						buffer_info_init_right(tb, &bi);
						leaf_paste_in_buffer(&bi, item_pos - n + tb->rnum[0], pos_in_item,
								     tb->insert_size[0], body, zeros_num);
					}

					/* paste new entry, if item is directory item */
					pasted = B_N_PITEM_HEAD(tb->R[0], item_pos - n + tb->rnum[0]);
					if (is_direntry_le_ih(pasted) && pos_in_item >= 0) {
						leaf_paste_entries(&bi, item_pos - n + tb->rnum[0],
								   pos_in_item, 1,
								   (struct reiserfs_de_head *) body,
								   body + DEH_SIZE, tb->insert_size[0]);
						if (!pos_in_item) {

							RFALSE(item_pos - n + tb->rnum[0],
							       "PAP-12165: directory item must be first item of node when pasting is in 0th position");

							/* update delimiting keys */
							replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
						}
					}

					if (is_indirect_le_ih(pasted))
						set_ih_free_space(pasted, 0);
					zeros_num = tb->insert_size[0] = 0;
				}
			} else {	/* new item doesn't fall into R[0] */

				leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
			}
			break;
		default:	/* cases d and t */
			reiserfs_panic(tb->tb_sb, "PAP-12175",
				       "rnum > 0: unexpected mode: %s(%d)",
				       (flag == M_DELETE) ? "DELETE" : ((flag == M_CUT) ? "CUT" : "UNKNOWN"), flag);
		}

	}

	/* tb->rnum[0] > 0 */
	RFALSE(tb->blknum[0] > 3,
	       "PAP-12180: blknum can not be %d. It must be <= 3", tb->blknum[0]);
	RFALSE(tb->blknum[0] < 0,
	       "PAP-12185: blknum can not be %d. It must be >= 0", tb->blknum[0]);

	/* if while adding to a node we discover that it is possible to split
	   it in two, and merge the left part into the left neighbor and the
	   right part into the right neighbor, eliminating the node */
	if (tb->blknum[0] == 0) {	/* node S[0] is empty now */

		RFALSE(!tb->lnum[0] || !tb->rnum[0],
		       "PAP-12190: lnum and rnum must not be zero");
		/* if insertion was done before 0-th position in R[0], right
		   delimiting key of the tb->L[0]'s and left delimiting key are
		   not set correctly */
		if (tb->CFL[0]) {
			if (!tb->CFR[0])
				reiserfs_panic(tb->tb_sb, "vs-12195",
					       "CFR not initialized");
			copy_key(B_N_PDELIM_KEY(tb->CFL[0], tb->lkey[0]),
				 B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0]));
			do_balance_mark_internal_dirty(tb, tb->CFL[0], 0);
		}

		reiserfs_invalidate_buffer(tb, tbS0);
		return 0;
	}

	/* Fill new nodes that appear in place of S[0] */

	/* I am told that this copying is because we need an array to enable
	   the looping code. -Hans */
	snum[0] = tb->s1num, snum[1] = tb->s2num;
	sbytes[0] = tb->s1bytes;
	sbytes[1] = tb->s2bytes;
	for (i = tb->blknum[0] - 2; i >= 0; i--) {

		RFALSE(!snum[i], "PAP-12200: snum[%d] == %d. Must be > 0", i,
		       snum[i]);

		/* here we shift from S to S_new nodes */

		S_new[i] = get_FEB(tb);

		/* initialized block type and tree level */
		set_blkh_level(B_BLK_HEAD(S_new[i]), DISK_LEAF_NODE_LEVEL);

		n = B_NR_ITEMS(tbS0);

		switch (flag) {
		case M_INSERT:	/* insert item */

			if (n - snum[i] < item_pos) {	/* new item or it's part falls to first new node S_new[i] */
				if (item_pos == n - snum[i] + 1 && sbytes[i] != -1) {	/* part of new item falls into S_new[i] */
					int old_key_comp, old_len, r_zeros_number;
					const char *r_body;
					int version;

					/* Move snum[i]-1 items from S[0] to S_new[i] */
					leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
							snum[i] - 1, -1,
							S_new[i]);
					/* Remember key component and item length */
					version = ih_version(ih);
					old_key_comp = le_ih_k_offset(ih);
					old_len = ih_item_len(ih);

					/* Calculate key component and item length to insert into S_new[i] */
					set_le_ih_k_offset(ih, le_ih_k_offset(ih) +
							   ((old_len - sbytes[i]) << (is_indirect_le_ih(ih) ? tb->tb_sb-> s_blocksize_bits - UNFM_P_SHIFT : 0)));

					put_ih_item_len(ih, sbytes[i]);

					/* Insert part of the item into S_new[i] before 0-th item */
					buffer_info_init_bh(tb, &bi, S_new[i]);

					if ((old_len - sbytes[i]) > zeros_num) {
						r_zeros_number = 0;
						r_body = body + (old_len - sbytes[i]) - zeros_num;
					} else {
						r_body = body;
						r_zeros_number = zeros_num - (old_len - sbytes[i]);
						zeros_num -= r_zeros_number;
					}

					leaf_insert_into_buf(&bi, 0, ih, r_body, r_zeros_number);

					/* Calculate key component and item length to insert into S[i] */
					set_le_ih_k_offset(ih, old_key_comp);
					put_ih_item_len(ih, old_len - sbytes[i]);
					tb->insert_size[0] -= sbytes[i];
				} else {	/* whole new item falls into S_new[i] */

					/* Shift snum[0] - 1 items to S_new[i] (sbytes[i] of split item) */
					leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
							snum[i] - 1, sbytes[i], S_new[i]);

					/* Insert new item into S_new[i] */
					buffer_info_init_bh(tb, &bi, S_new[i]);
					leaf_insert_into_buf(&bi, item_pos - n + snum[i] - 1,
							     ih, body, zeros_num);

					zeros_num = tb->insert_size[0] = 0;
				}
			}

			else {	/* new item or it part don't falls into S_new[i] */

				leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
						snum[i], sbytes[i], S_new[i]);
			}
			break;

		case M_PASTE:	/* append item */

			if (n - snum[i] <= item_pos) {	/* pasted item or part if it falls to S_new[i] */
				if (item_pos == n - snum[i] && sbytes[i] != -1) {	/* we must shift part of the appended item */
					struct item_head *aux_ih;

					RFALSE(ih, "PAP-12210: ih must be 0");

					aux_ih = B_N_PITEM_HEAD(tbS0, item_pos);
					if (is_direntry_le_ih(aux_ih)) {
						/* we append to directory item */

						int entry_count;

						entry_count = ih_entry_count(aux_ih);

						if (entry_count - sbytes[i] < pos_in_item && pos_in_item <= entry_count) {
							/* new directory entry falls into S_new[i] */

							RFALSE(!tb->insert_size[0], "PAP-12215: insert_size is already 0");
							RFALSE(sbytes[i] - 1 >= entry_count,
							       "PAP-12220: there are no so much entries (%d), only %d",
							       sbytes[i] - 1, entry_count);

							/* Shift snum[i]-1 items in whole. Shift sbytes[i] directory entries from directory item number snum[i] */
							leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, snum[i], sbytes[i] - 1, S_new[i]);
							/* Paste given directory entry to directory item */
							buffer_info_init_bh(tb, &bi, S_new[i]);
							leaf_paste_in_buffer(&bi, 0, pos_in_item - entry_count + sbytes[i] - 1,
							     tb->insert_size[0], body, zeros_num);
							/* paste new directory entry */
							leaf_paste_entries(&bi, 0, pos_in_item - entry_count + sbytes[i] - 1, 1,
									   (struct reiserfs_de_head *) body,
									   body + DEH_SIZE, tb->insert_size[0]);
							tb->insert_size[0] = 0;
							pos_in_item++;
						} else {	/* new directory entry doesn't fall into S_new[i] */
							leaf_move_items(LEAF_FROM_S_TO_SNEW,tb, snum[i], sbytes[i], S_new[i]);
						}
					} else {	/* regular object */

						int n_shift, n_rem, r_zeros_number;
						const char *r_body;

						RFALSE(pos_in_item != ih_item_len(B_N_PITEM_HEAD(tbS0, item_pos)) || tb->insert_size[0] <= 0,
						       "PAP-12225: item too short or insert_size <= 0");

						/* Calculate number of bytes which must be shifted from appended item */
						n_shift = sbytes[i] - tb->insert_size[0];
						if (n_shift < 0)
							n_shift = 0;
						leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, snum[i], n_shift, S_new[i]);

						/* Calculate number of bytes which must remain in body after append to S_new[i] */
						n_rem = tb->insert_size[0] - sbytes[i];
						if (n_rem < 0)
							n_rem = 0;
						/* Append part of body into S_new[0] */
						buffer_info_init_bh(tb, &bi, S_new[i]);
						if (n_rem > zeros_num) {
							r_zeros_number = 0;
							r_body = body + n_rem - zeros_num;
						} else {
							r_body = body;
							r_zeros_number = zeros_num - n_rem;
							zeros_num -= r_zeros_number;
						}

						leaf_paste_in_buffer(&bi, 0, n_shift,
								     tb->insert_size[0] - n_rem,
								     r_body, r_zeros_number);
						{
							struct item_head *tmp;

							tmp = B_N_PITEM_HEAD(S_new[i], 0);
							if (is_indirect_le_ih
							    (tmp)) {
								set_ih_free_space(tmp, 0);
								set_le_ih_k_offset(tmp, le_ih_k_offset(tmp) + (n_rem << (tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT)));
							} else {
								set_le_ih_k_offset(tmp, le_ih_k_offset(tmp) + n_rem);
							}
						}

						tb->insert_size[0] = n_rem;
						if (!n_rem)
							pos_in_item++;
					}
				} else
					/* item falls wholly into S_new[i] */
				{
					int leaf_mi;
					struct item_head *pasted;

#ifdef CONFIG_REISERFS_CHECK
					struct item_head *ih_check = B_N_PITEM_HEAD(tbS0, item_pos);

					if (!is_direntry_le_ih(ih_check)
					    && (pos_in_item != ih_item_len(ih_check)
						|| tb->insert_size[0] <= 0))
						reiserfs_panic(tb->tb_sb,
							     "PAP-12235",
							     "pos_in_item "
							     "must be equal "
							     "to ih_item_len");
#endif				/* CONFIG_REISERFS_CHECK */

					leaf_mi = leaf_move_items(LEAF_FROM_S_TO_SNEW,
							    tb, snum[i],
							    sbytes[i],
							    S_new[i]);

					RFALSE(leaf_mi,
					       "PAP-12240: unexpected value returned by leaf_move_items (%d)",
					       leaf_mi);

					/* paste into item */
					buffer_info_init_bh(tb, &bi, S_new[i]);
					leaf_paste_in_buffer(&bi,
							     item_pos - n + snum[i],
							     pos_in_item,
							     tb->insert_size[0],
							     body, zeros_num);

					pasted = B_N_PITEM_HEAD(S_new[i], item_pos - n + snum[i]);
					if (is_direntry_le_ih(pasted)) {
						leaf_paste_entries(&bi,
								   item_pos - n + snum[i],
								   pos_in_item, 1,
								   (struct reiserfs_de_head *)body,
								   body + DEH_SIZE,
								   tb->insert_size[0]
						    );
					}

					/* if we paste to indirect item update ih_free_space */
					if (is_indirect_le_ih(pasted))
						set_ih_free_space(pasted, 0);
					zeros_num = tb->insert_size[0] = 0;
				}
			}

			else {	/* pasted item doesn't fall into S_new[i] */

				leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
						snum[i], sbytes[i], S_new[i]);
			}
			break;
		default:	/* cases d and t */
			reiserfs_panic(tb->tb_sb, "PAP-12245",
				       "blknum > 2: unexpected mode: %s(%d)",
				       (flag == M_DELETE) ? "DELETE" : ((flag == M_CUT) ? "CUT" : "UNKNOWN"), flag);
		}

		memcpy(insert_key + i, B_N_PKEY(S_new[i], 0), KEY_SIZE);
		insert_ptr[i] = S_new[i];

		RFALSE(!buffer_journaled(S_new[i])
		       || buffer_journal_dirty(S_new[i])
		       || buffer_dirty(S_new[i]), "PAP-12247: S_new[%d] : (%b)",
		       i, S_new[i]);
	}

	/* if the affected item was not wholly shifted then we perform all necessary operations on that part or whole of the
	   affected item which remains in S */
	if (0 <= item_pos && item_pos < tb->s0num) {	/* if we must insert or append into buffer S[0] */

		switch (flag) {
		case M_INSERT:	/* insert item into S[0] */
			buffer_info_init_tbS0(tb, &bi);
			leaf_insert_into_buf(&bi, item_pos, ih, body,
					     zeros_num);

			/* If we insert the first key change the delimiting key */
			if (item_pos == 0) {
				if (tb->CFL[0])	/* can be 0 in reiserfsck */
					replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
			}
			break;

		case M_PASTE:{	/* append item in S[0] */
				struct item_head *pasted;

				pasted = B_N_PITEM_HEAD(tbS0, item_pos);
				/* when directory, may be new entry already pasted */
				if (is_direntry_le_ih(pasted)) {
					if (pos_in_item >= 0 && pos_in_item <= ih_entry_count(pasted)) {

						RFALSE(!tb->insert_size[0],
						       "PAP-12260: insert_size is 0 already");

						/* prepare space */
						buffer_info_init_tbS0(tb, &bi);
						leaf_paste_in_buffer(&bi, item_pos, pos_in_item,
								     tb->insert_size[0], body,
								     zeros_num);

						/* paste entry */
						leaf_paste_entries(&bi, item_pos, pos_in_item, 1,
								   (struct reiserfs_de_head *)body,
								   body + DEH_SIZE,
								   tb->insert_size[0]);
						if (!item_pos && !pos_in_item) {
							RFALSE(!tb->CFL[0] || !tb->L[0],
							       "PAP-12270: CFL[0]/L[0] must be specified");
							if (tb->CFL[0])
								replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
						}
						tb->insert_size[0] = 0;
					}
				} else {	/* regular object */
					if (pos_in_item == ih_item_len(pasted)) {

						RFALSE(tb->insert_size[0] <= 0,
						       "PAP-12275: insert size must not be %d",
						       tb->insert_size[0]);
						buffer_info_init_tbS0(tb, &bi);
						leaf_paste_in_buffer(&bi, item_pos, pos_in_item,
								     tb->insert_size[0], body, zeros_num);

						if (is_indirect_le_ih(pasted)) {
#if 0
							RFALSE(tb->
							       insert_size[0] !=
							       UNFM_P_SIZE,
							       "PAP-12280: insert_size for indirect item must be %d, not %d",
							       UNFM_P_SIZE,
							       tb->
							       insert_size[0]);
#endif
							set_ih_free_space(pasted, 0);
						}
						tb->insert_size[0] = 0;
					}
#ifdef CONFIG_REISERFS_CHECK
					else {
						if (tb->insert_size[0]) {
							print_cur_tb("12285");
							reiserfs_panic(tb->tb_sb,
							    "PAP-12285",
							    "insert_size "
							    "must be 0 "
							    "(%d)",
							    tb->insert_size[0]);
						}
					}
#endif				/* CONFIG_REISERFS_CHECK */

				}
			}	/* case M_PASTE: */
		}
	}
#ifdef CONFIG_REISERFS_CHECK
	if (flag == M_PASTE && tb->insert_size[0]) {
		print_cur_tb("12290");
		reiserfs_panic(tb->tb_sb,
			       "PAP-12290", "insert_size is still not 0 (%d)",
			       tb->insert_size[0]);
	}
#endif				/* CONFIG_REISERFS_CHECK */
	return 0;
}				/* Leaf level of the tree is balanced (end of balance_leaf) */

/* Make empty node */
void make_empty_node(struct buffer_info *bi)
{
	struct block_head *blkh;

	RFALSE(bi->bi_bh == NULL, "PAP-12295: pointer to the buffer is NULL");

	blkh = B_BLK_HEAD(bi->bi_bh);
	set_blkh_nr_item(blkh, 0);
	set_blkh_free_space(blkh, MAX_CHILD_SIZE(bi->bi_bh));

	if (bi->bi_parent)
		B_N_CHILD(bi->bi_parent, bi->bi_position)->dc_size = 0;	/* Endian safe if 0 */
}

/* Get first empty buffer */
struct buffer_head *get_FEB(struct tree_balance *tb)
{
	int i;
	struct buffer_info bi;

	for (i = 0; i < MAX_FEB_SIZE; i++)
		if (tb->FEB[i] != NULL)
			break;

	if (i == MAX_FEB_SIZE)
		reiserfs_panic(tb->tb_sb, "vs-12300", "FEB list is empty");

	buffer_info_init_bh(tb, &bi, tb->FEB[i]);
	make_empty_node(&bi);
	set_buffer_uptodate(tb->FEB[i]);
	tb->used[i] = tb->FEB[i];
	tb->FEB[i] = NULL;

	return tb->used[i];
}

/* This is now used because reiserfs_free_block has to be able to
** schedule.
*/
static void store_thrown(struct tree_balance *tb, struct buffer_head *bh)
{
	int i;

	if (buffer_dirty(bh))
		reiserfs_warning(tb->tb_sb, "reiserfs-12320",
				 "called with dirty buffer");
	for (i = 0; i < ARRAY_SIZE(tb->thrown); i++)
		if (!tb->thrown[i]) {
			tb->thrown[i] = bh;
			get_bh(bh);	/* free_thrown puts this */
			return;
		}
	reiserfs_warning(tb->tb_sb, "reiserfs-12321",
			 "too many thrown buffers");
}

static void free_thrown(struct tree_balance *tb)
{
	int i;
	b_blocknr_t blocknr;
	for (i = 0; i < ARRAY_SIZE(tb->thrown); i++) {
		if (tb->thrown[i]) {
			blocknr = tb->thrown[i]->b_blocknr;
			if (buffer_dirty(tb->thrown[i]))
				reiserfs_warning(tb->tb_sb, "reiserfs-12322",
						 "called with dirty buffer %d",
						 blocknr);
			brelse(tb->thrown[i]);	/* incremented in store_thrown */
			reiserfs_free_block(tb->transaction_handle, NULL,
					    blocknr, 0);
		}
	}
}

void reiserfs_invalidate_buffer(struct tree_balance *tb, struct buffer_head *bh)
{
	struct block_head *blkh;
	blkh = B_BLK_HEAD(bh);
	set_blkh_level(blkh, FREE_LEVEL);
	set_blkh_nr_item(blkh, 0);

	clear_buffer_dirty(bh);
	store_thrown(tb, bh);
}

/* Replace n_dest'th key in buffer dest by n_src'th key of buffer src.*/
void replace_key(struct tree_balance *tb, struct buffer_head *dest, int n_dest,
		 struct buffer_head *src, int n_src)
{

	RFALSE(dest == NULL || src == NULL,
	       "vs-12305: source or destination buffer is 0 (src=%p, dest=%p)",
	       src, dest);
	RFALSE(!B_IS_KEYS_LEVEL(dest),
	       "vs-12310: invalid level (%z) for destination buffer. dest must be leaf",
	       dest);
	RFALSE(n_dest < 0 || n_src < 0,
	       "vs-12315: src(%d) or dest(%d) key number < 0", n_src, n_dest);
	RFALSE(n_dest >= B_NR_ITEMS(dest) || n_src >= B_NR_ITEMS(src),
	       "vs-12320: src(%d(%d)) or dest(%d(%d)) key number is too big",
	       n_src, B_NR_ITEMS(src), n_dest, B_NR_ITEMS(dest));

	if (B_IS_ITEMS_LEVEL(src))
		/* source buffer contains leaf node */
		memcpy(B_N_PDELIM_KEY(dest, n_dest), B_N_PITEM_HEAD(src, n_src),
		       KEY_SIZE);
	else
		memcpy(B_N_PDELIM_KEY(dest, n_dest), B_N_PDELIM_KEY(src, n_src),
		       KEY_SIZE);

	do_balance_mark_internal_dirty(tb, dest, 0);
}

int get_left_neighbor_position(struct tree_balance *tb, int h)
{
	int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);

	RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FL[h] == NULL,
	       "vs-12325: FL[%d](%p) or F[%d](%p) does not exist",
	       h, tb->FL[h], h, PATH_H_PPARENT(tb->tb_path, h));

	if (Sh_position == 0)
		return B_NR_ITEMS(tb->FL[h]);
	else
		return Sh_position - 1;
}

int get_right_neighbor_position(struct tree_balance *tb, int h)
{
	int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);

	RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FR[h] == NULL,
	       "vs-12330: F[%d](%p) or FR[%d](%p) does not exist",
	       h, PATH_H_PPARENT(tb->tb_path, h), h, tb->FR[h]);

	if (Sh_position == B_NR_ITEMS(PATH_H_PPARENT(tb->tb_path, h)))
		return 0;
	else
		return Sh_position + 1;
}

#ifdef CONFIG_REISERFS_CHECK

int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value);
static void check_internal_node(struct super_block *s, struct buffer_head *bh,
				char *mes)
{
	struct disk_child *dc;
	int i;

	RFALSE(!bh, "PAP-12336: bh == 0");

	if (!bh || !B_IS_IN_TREE(bh))
		return;

	RFALSE(!buffer_dirty(bh) &&
	       !(buffer_journaled(bh) || buffer_journal_dirty(bh)),
	       "PAP-12337: buffer (%b) must be dirty", bh);
	dc = B_N_CHILD(bh, 0);

	for (i = 0; i <= B_NR_ITEMS(bh); i++, dc++) {
		if (!is_reusable(s, dc_block_number(dc), 1)) {
			print_cur_tb(mes);
			reiserfs_panic(s, "PAP-12338",
				       "invalid child pointer %y in %b",
				       dc, bh);
		}
	}
}

static int locked_or_not_in_tree(struct tree_balance *tb,
				  struct buffer_head *bh, char *which)
{
	if ((!buffer_journal_prepared(bh) && buffer_locked(bh)) ||
	    !B_IS_IN_TREE(bh)) {
		reiserfs_warning(tb->tb_sb, "vs-12339", "%s (%b)", which, bh);
		return 1;
	}
	return 0;
}

static int check_before_balancing(struct tree_balance *tb)
{
	int retval = 0;

	if (REISERFS_SB(tb->tb_sb)->cur_tb) {
		reiserfs_panic(tb->tb_sb, "vs-12335", "suspect that schedule "
			       "occurred based on cur_tb not being null at "
			       "this point in code. do_balance cannot properly "
			       "handle concurrent tree accesses on a same "
			       "mount point.");
	}

	/* double check that buffers that we will modify are unlocked. (fix_nodes should already have
	   prepped all of these for us). */
	if (tb->lnum[0]) {
		retval |= locked_or_not_in_tree(tb, tb->L[0], "L[0]");
		retval |= locked_or_not_in_tree(tb, tb->FL[0], "FL[0]");
		retval |= locked_or_not_in_tree(tb, tb->CFL[0], "CFL[0]");
		check_leaf(tb->L[0]);
	}
	if (tb->rnum[0]) {
		retval |= locked_or_not_in_tree(tb, tb->R[0], "R[0]");
		retval |= locked_or_not_in_tree(tb, tb->FR[0], "FR[0]");
		retval |= locked_or_not_in_tree(tb, tb->CFR[0], "CFR[0]");
		check_leaf(tb->R[0]);
	}
	retval |= locked_or_not_in_tree(tb, PATH_PLAST_BUFFER(tb->tb_path),
					"S[0]");
	check_leaf(PATH_PLAST_BUFFER(tb->tb_path));

	return retval;
}

static void check_after_balance_leaf(struct tree_balance *tb)
{
	if (tb->lnum[0]) {
		if (B_FREE_SPACE(tb->L[0]) !=
		    MAX_CHILD_SIZE(tb->L[0]) -
		    dc_size(B_N_CHILD
			    (tb->FL[0], get_left_neighbor_position(tb, 0)))) {
			print_cur_tb("12221");
			reiserfs_panic(tb->tb_sb, "PAP-12355",
				       "shift to left was incorrect");
		}
	}
	if (tb->rnum[0]) {
		if (B_FREE_SPACE(tb->R[0]) !=
		    MAX_CHILD_SIZE(tb->R[0]) -
		    dc_size(B_N_CHILD
			    (tb->FR[0], get_right_neighbor_position(tb, 0)))) {
			print_cur_tb("12222");
			reiserfs_panic(tb->tb_sb, "PAP-12360",
				       "shift to right was incorrect");
		}
	}
	if (PATH_H_PBUFFER(tb->tb_path, 1) &&
	    (B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0)) !=
	     (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
	      dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
				PATH_H_POSITION(tb->tb_path, 1)))))) {
		int left = B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0));
		int right = (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
			     dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
					       PATH_H_POSITION(tb->tb_path,
							       1))));
		print_cur_tb("12223");
		reiserfs_warning(tb->tb_sb, "reiserfs-12363",
				 "B_FREE_SPACE (PATH_H_PBUFFER(tb->tb_path,0)) = %d; "
				 "MAX_CHILD_SIZE (%d) - dc_size( %y, %d ) [%d] = %d",
				 left,
				 MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)),
				 PATH_H_PBUFFER(tb->tb_path, 1),
				 PATH_H_POSITION(tb->tb_path, 1),
				 dc_size(B_N_CHILD
					 (PATH_H_PBUFFER(tb->tb_path, 1),
					  PATH_H_POSITION(tb->tb_path, 1))),
				 right);
		reiserfs_panic(tb->tb_sb, "PAP-12365", "S is incorrect");
	}
}

static void check_leaf_level(struct tree_balance *tb)
{
	check_leaf(tb->L[0]);
	check_leaf(tb->R[0]);
	check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
}

static void check_internal_levels(struct tree_balance *tb)
{
	int h;

	/* check all internal nodes */
	for (h = 1; tb->insert_size[h]; h++) {
		check_internal_node(tb->tb_sb, PATH_H_PBUFFER(tb->tb_path, h),
				    "BAD BUFFER ON PATH");
		if (tb->lnum[h])
			check_internal_node(tb->tb_sb, tb->L[h], "BAD L");
		if (tb->rnum[h])
			check_internal_node(tb->tb_sb, tb->R[h], "BAD R");
	}

}

#endif

/* Now we have all of the buffers that must be used in balancing of
   the tree.  We rely on the assumption that schedule() will not occur
   while do_balance works. ( Only interrupt handlers are acceptable.)
   We balance the tree according to the analysis made before this,
   using buffers already obtained.  For SMP support it will someday be
   necessary to add ordered locking of tb. */

/* Some interesting rules of balancing:

   we delete a maximum of two nodes per level per balancing: we never
   delete R, when we delete two of three nodes L, S, R then we move
   them into R.

   we only delete L if we are deleting two nodes, if we delete only
   one node we delete S

   if we shift leaves then we shift as much as we can: this is a
   deliberate policy of extremism in node packing which results in
   higher average utilization after repeated random balance operations
   at the cost of more memory copies and more balancing as a result of
   small insertions to full nodes.

   if we shift internal nodes we try to evenly balance the node
   utilization, with consequent less balancing at the cost of lower
   utilization.

   one could argue that the policy for directories in leaves should be
   that of internal nodes, but we will wait until another day to
   evaluate this....  It would be nice to someday measure and prove
   these assumptions as to what is optimal....

*/

static inline void do_balance_starts(struct tree_balance *tb)
{
	/* use print_cur_tb() to see initial state of struct
	   tree_balance */

	/* store_print_tb (tb); */

	/* do not delete, just comment it out */
/*    print_tb(flag, PATH_LAST_POSITION(tb->tb_path), tb->tb_path->pos_in_item, tb,
	     "check");*/
	RFALSE(check_before_balancing(tb), "PAP-12340: locked buffers in TB");
#ifdef CONFIG_REISERFS_CHECK
	REISERFS_SB(tb->tb_sb)->cur_tb = tb;
#endif
}

static inline void do_balance_completed(struct tree_balance *tb)
{

#ifdef CONFIG_REISERFS_CHECK
	check_leaf_level(tb);
	check_internal_levels(tb);
	REISERFS_SB(tb->tb_sb)->cur_tb = NULL;
#endif

	/* reiserfs_free_block is no longer schedule safe.  So, we need to
	 ** put the buffers we want freed on the thrown list during do_balance,
	 ** and then free them now
	 */

	REISERFS_SB(tb->tb_sb)->s_do_balance++;

	/* release all nodes hold to perform the balancing */
	unfix_nodes(tb);

	free_thrown(tb);
}

void do_balance(struct tree_balance *tb,	/* tree_balance structure */
		struct item_head *ih,	/* item header of inserted item */
		const char *body,	/* body  of inserted item or bytes to paste */
		int flag)
{				/* i - insert, d - delete
				   c - cut, p - paste

				   Cut means delete part of an item
				   (includes removing an entry from a
				   directory).

				   Delete means delete whole item.

				   Insert means add a new item into the
				   tree.

				   Paste means to append to the end of an
				   existing file or to insert a directory
				   entry.  */
	int child_pos,		/* position of a child node in its parent */
	 h;			/* level of the tree being processed */
	struct item_head insert_key[2];	/* in our processing of one level
					   we sometimes determine what
					   must be inserted into the next
					   higher level.  This insertion
					   consists of a key or two keys
					   and their corresponding
					   pointers */
	struct buffer_head *insert_ptr[2];	/* inserted node-ptrs for the next
						   level */

	tb->tb_mode = flag;
	tb->need_balance_dirty = 0;

	if (FILESYSTEM_CHANGED_TB(tb)) {
		reiserfs_panic(tb->tb_sb, "clm-6000", "fs generation has "
			       "changed");
	}
	/* if we have no real work to do  */
	if (!tb->insert_size[0]) {
		reiserfs_warning(tb->tb_sb, "PAP-12350",
				 "insert_size == 0, mode == %c", flag);
		unfix_nodes(tb);
		return;
	}

	atomic_inc(&(fs_generation(tb->tb_sb)));
	do_balance_starts(tb);

	/* balance leaf returns 0 except if combining L R and S into
	   one node.  see balance_internal() for explanation of this
	   line of code. */
	child_pos = PATH_H_B_ITEM_ORDER(tb->tb_path, 0) +
	    balance_leaf(tb, ih, body, flag, insert_key, insert_ptr);

#ifdef CONFIG_REISERFS_CHECK
	check_after_balance_leaf(tb);
#endif

	/* Balance internal level of the tree. */
	for (h = 1; h < MAX_HEIGHT && tb->insert_size[h]; h++)
		child_pos =
		    balance_internal(tb, h, child_pos, insert_key, insert_ptr);

	do_balance_completed(tb);

}