fs/reiserfs/do_balan.c

   1 /*
   2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
   3  */
   4
   5 /*
   6  * Now we have all buffers that must be used in balancing of the tree
   7  * Further calculations can not cause schedule(), and thus the buffer
   8  * tree will be stable until the balancing will be finished
   9  * balance the tree according to the analysis made before,
  10  * and using buffers obtained after all above.
  11  */
  12
  13 #include <asm/uaccess.h>
  14 #include <linux/time.h>
  15 #include "reiserfs.h"
  16 #include <linux/buffer_head.h>
  17 #include <linux/kernel.h>
  18
  19 static inline void buffer_info_init_left(struct tree_balance *tb,
  20                                          struct buffer_info *bi)
  21 {
  22         bi->tb          = tb;
  23         bi->bi_bh       = tb->L[0];
  24         bi->bi_parent   = tb->FL[0];
  25         bi->bi_position = get_left_neighbor_position(tb, 0);
  26 }
  27
  28 static inline void buffer_info_init_right(struct tree_balance *tb,
  29                                           struct buffer_info *bi)
  30 {
  31         bi->tb          = tb;
  32         bi->bi_bh       = tb->R[0];
  33         bi->bi_parent   = tb->FR[0];
  34         bi->bi_position = get_right_neighbor_position(tb, 0);
  35 }
  36
  37 static inline void buffer_info_init_tbS0(struct tree_balance *tb,
  38                                          struct buffer_info *bi)
  39 {
  40         bi->tb          = tb;
  41         bi->bi_bh        = PATH_PLAST_BUFFER(tb->tb_path);
  42         bi->bi_parent   = PATH_H_PPARENT(tb->tb_path, 0);
  43         bi->bi_position = PATH_H_POSITION(tb->tb_path, 1);
  44 }
  45
  46 static inline void buffer_info_init_bh(struct tree_balance *tb,
  47                                        struct buffer_info *bi,
  48                                        struct buffer_head *bh)
  49 {
  50         bi->tb          = tb;
  51         bi->bi_bh       = bh;
  52         bi->bi_parent   = NULL;
  53         bi->bi_position = 0;
  54 }
  55
  56 inline void do_balance_mark_leaf_dirty(struct tree_balance *tb,
  57                                        struct buffer_head *bh, int flag)
  58 {
  59         journal_mark_dirty(tb->transaction_handle, bh);
  60 }
  61
  62 #define do_balance_mark_internal_dirty do_balance_mark_leaf_dirty
  63 #define do_balance_mark_sb_dirty do_balance_mark_leaf_dirty
  64
  65 /*
  66  * summary:
  67  *  if deleting something ( tb->insert_size[0] < 0 )
  68  *    return(balance_leaf_when_delete()); (flag d handled here)
  69  *  else
  70  *    if lnum is larger than 0 we put items into the left node
  71  *    if rnum is larger than 0 we put items into the right node
  72  *    if snum1 is larger than 0 we put items into the new node s1
  73  *    if snum2 is larger than 0 we put items into the new node s2
  74  * Note that all *num* count new items being created.
  75  *
  76  * It would be easier to read balance_leaf() if each of these summary
  77  * lines was a separate procedure rather than being inlined.  I think
  78  * that there are many passages here and in balance_leaf_when_delete() in
  79  * which two calls to one procedure can replace two passages, and it
  80  * might save cache space and improve software maintenance costs to do so.
  81  *
  82  * Vladimir made the perceptive comment that we should offload most of
  83  * the decision making in this function into fix_nodes/check_balance, and
  84  * then create some sort of structure in tb that says what actions should
  85  * be performed by do_balance.
  86  *
  87  * -Hans
  88  */
  89
  90 /*
  91  * Balance leaf node in case of delete or cut: insert_size[0] < 0
  92  *
  93  * lnum, rnum can have values >= -1
  94  *      -1 means that the neighbor must be joined with S
  95  *       0 means that nothing should be done with the neighbor
  96  *      >0 means to shift entirely or partly the specified number of items
  97  *         to the neighbor
  98  */
  99 static int balance_leaf_when_delete(struct tree_balance *tb, int flag)
 100 {
 101         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
 102         int item_pos = PATH_LAST_POSITION(tb->tb_path);
 103         int pos_in_item = tb->tb_path->pos_in_item;
 104         struct buffer_info bi;
 105         int n;
 106         struct item_head *ih;
 107
 108         RFALSE(tb->FR[0] && B_LEVEL(tb->FR[0]) != DISK_LEAF_NODE_LEVEL + 1,
 109                "vs- 12000: level: wrong FR %z", tb->FR[0]);
 110         RFALSE(tb->blknum[0] > 1,
 111                "PAP-12005: tb->blknum == %d, can not be > 1", tb->blknum[0]);
 112         RFALSE(!tb->blknum[0] && !PATH_H_PPARENT(tb->tb_path, 0),
 113                "PAP-12010: tree can not be empty");
 114
 115         ih = item_head(tbS0, item_pos);
 116         buffer_info_init_tbS0(tb, &bi);
 117
 118         /* Delete or truncate the item */
 119
 120         switch (flag) {
 121         case M_DELETE:          /* delete item in S[0] */
 122
 123                 RFALSE(ih_item_len(ih) + IH_SIZE != -tb->insert_size[0],
 124                        "vs-12013: mode Delete, insert size %d, ih to be deleted %h",
 125                        -tb->insert_size[0], ih);
 126
 127                 leaf_delete_items(&bi, 0, item_pos, 1, -1);
 128
 129                 if (!item_pos && tb->CFL[0]) {
 130                         if (B_NR_ITEMS(tbS0)) {
 131                                 replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0,
 132                                             0);
 133                         } else {
 134                                 if (!PATH_H_POSITION(tb->tb_path, 1))
 135                                         replace_key(tb, tb->CFL[0], tb->lkey[0],
 136                                                     PATH_H_PPARENT(tb->tb_path,
 137                                                                    0), 0);
 138                         }
 139                 }
 140
 141                 RFALSE(!item_pos && !tb->CFL[0],
 142                        "PAP-12020: tb->CFL[0]==%p, tb->L[0]==%p", tb->CFL[0],
 143                        tb->L[0]);
 144
 145                 break;
 146
 147         case M_CUT:{            /* cut item in S[0] */
 148                         if (is_direntry_le_ih(ih)) {
 149
 150                                 /*
 151                                  * UFS unlink semantics are such that you
 152                                  * can only delete one directory entry at
 153                                  * a time.
 154                                  */
 155
 156                                 /*
 157                                  * when we cut a directory tb->insert_size[0]
 158                                  * means number of entries to be cut (always 1)
 159                                  */
 160                                 tb->insert_size[0] = -1;
 161                                 leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
 162                                                      -tb->insert_size[0]);
 163
 164                                 RFALSE(!item_pos && !pos_in_item && !tb->CFL[0],
 165                                        "PAP-12030: can not change delimiting key. CFL[0]=%p",
 166                                        tb->CFL[0]);
 167
 168                                 if (!item_pos && !pos_in_item && tb->CFL[0]) {
 169                                         replace_key(tb, tb->CFL[0], tb->lkey[0],
 170                                                     tbS0, 0);
 171                                 }
 172                         } else {
 173                                 leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
 174                                                      -tb->insert_size[0]);
 175
 176                                 RFALSE(!ih_item_len(ih),
 177                                        "PAP-12035: cut must leave non-zero dynamic length of item");
 178                         }
 179                         break;
 180                 }
 181
 182         default:
 183                 print_cur_tb("12040");
 184                 reiserfs_panic(tb->tb_sb, "PAP-12040",
 185                                "unexpected mode: %s(%d)",
 186                                (flag ==
 187                                 M_PASTE) ? "PASTE" : ((flag ==
 188                                                        M_INSERT) ? "INSERT" :
 189                                                       "UNKNOWN"), flag);
 190         }
 191
 192         /*
 193          * the rule is that no shifting occurs unless by shifting
 194          * a node can be freed
 195          */
 196         n = B_NR_ITEMS(tbS0);
 197         /* L[0] takes part in balancing */
 198         if (tb->lnum[0]) {
 199                 /* L[0] must be joined with S[0] */
 200                 if (tb->lnum[0] == -1) {
 201                         /* R[0] must be also joined with S[0] */
 202                         if (tb->rnum[0] == -1) {
 203                                 if (tb->FR[0] == PATH_H_PPARENT(tb->tb_path, 0)) {
 204                                         /*
 205                                          * all contents of all the 3 buffers
 206                                          * will be in L[0]
 207                                          */
 208                                         if (PATH_H_POSITION(tb->tb_path, 1) == 0
 209                                             && 1 < B_NR_ITEMS(tb->FR[0]))
 210                                                 replace_key(tb, tb->CFL[0],
 211                                                             tb->lkey[0],
 212                                                             tb->FR[0], 1);
 213
 214                                         leaf_move_items(LEAF_FROM_S_TO_L, tb, n,
 215                                                         -1, NULL);
 216                                         leaf_move_items(LEAF_FROM_R_TO_L, tb,
 217                                                         B_NR_ITEMS(tb->R[0]),
 218                                                         -1, NULL);
 219
 220                                         reiserfs_invalidate_buffer(tb, tbS0);
 221                                         reiserfs_invalidate_buffer(tb,
 222                                                                    tb->R[0]);
 223
 224                                         return 0;
 225                                 }
 226                                 /*
 227                                  * all contents of all the 3 buffers will
 228                                  * be in R[0]
 229                                  */
 230                                 leaf_move_items(LEAF_FROM_S_TO_R, tb, n, -1,
 231                                                 NULL);
 232                                 leaf_move_items(LEAF_FROM_L_TO_R, tb,
 233                                                 B_NR_ITEMS(tb->L[0]), -1, NULL);
 234
 235                                 /* right_delimiting_key is correct in R[0] */
 236                                 replace_key(tb, tb->CFR[0], tb->rkey[0],
 237                                             tb->R[0], 0);
 238
 239                                 reiserfs_invalidate_buffer(tb, tbS0);
 240                                 reiserfs_invalidate_buffer(tb, tb->L[0]);
 241
 242                                 return -1;
 243                         }
 244
 245                         RFALSE(tb->rnum[0] != 0,
 246                                "PAP-12045: rnum must be 0 (%d)", tb->rnum[0]);
 247                         /* all contents of L[0] and S[0] will be in L[0] */
 248                         leaf_shift_left(tb, n, -1);
 249
 250                         reiserfs_invalidate_buffer(tb, tbS0);
 251
 252                         return 0;
 253                 }
 254
 255                 /*
 256                  * a part of contents of S[0] will be in L[0] and the
 257                  * rest part of S[0] will be in R[0]
 258                  */
 259
 260                 RFALSE((tb->lnum[0] + tb->rnum[0] < n) ||
 261                        (tb->lnum[0] + tb->rnum[0] > n + 1),
 262                        "PAP-12050: rnum(%d) and lnum(%d) and item number(%d) in S[0] are not consistent",
 263                        tb->rnum[0], tb->lnum[0], n);
 264                 RFALSE((tb->lnum[0] + tb->rnum[0] == n) &&
 265                        (tb->lbytes != -1 || tb->rbytes != -1),
 266                        "PAP-12055: bad rbytes (%d)/lbytes (%d) parameters when items are not split",
 267                        tb->rbytes, tb->lbytes);
 268                 RFALSE((tb->lnum[0] + tb->rnum[0] == n + 1) &&
 269                        (tb->lbytes < 1 || tb->rbytes != -1),
 270                        "PAP-12060: bad rbytes (%d)/lbytes (%d) parameters when items are split",
 271                        tb->rbytes, tb->lbytes);
 272
 273                 leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
 274                 leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
 275
 276                 reiserfs_invalidate_buffer(tb, tbS0);
 277
 278                 return 0;
 279         }
 280
 281         if (tb->rnum[0] == -1) {
 282                 /* all contents of R[0] and S[0] will be in R[0] */
 283                 leaf_shift_right(tb, n, -1);
 284                 reiserfs_invalidate_buffer(tb, tbS0);
 285                 return 0;
 286         }
 287
 288         RFALSE(tb->rnum[0],
 289                "PAP-12065: bad rnum parameter must be 0 (%d)", tb->rnum[0]);
 290         return 0;
 291 }
 292
 293 static void balance_leaf_insert_left(struct tree_balance *tb,
 294                                      struct item_head *ih, const char *body)
 295 {
 296         int ret_val;
 297         struct buffer_info bi;
 298         int n = B_NR_ITEMS(tb->L[0]);
 299
 300                                 if (tb->item_pos == tb->lnum[0] - 1 && tb->lbytes != -1) {
 301                                         /* part of new item falls into L[0] */
 302                                         int new_item_len;
 303                                         int version;
 304
 305                                         ret_val = leaf_shift_left(tb, tb->lnum[0] - 1, -1);
 306
 307                                         /* Calculate item length to insert to S[0] */
 308                                         new_item_len = ih_item_len(ih) - tb->lbytes;
 309                                         /* Calculate and check item length to insert to L[0] */
 310                                         put_ih_item_len(ih, ih_item_len(ih) - new_item_len);
 311
 312                                         RFALSE(ih_item_len(ih) <= 0,
 313                                                "PAP-12080: there is nothing to insert into L[0]: ih_item_len=%d",
 314                                                ih_item_len(ih));
 315
 316                                         /* Insert new item into L[0] */
 317                                         buffer_info_init_left(tb, &bi);
 318                                         leaf_insert_into_buf(&bi,
 319                                                         n + tb->item_pos - ret_val, ih, body,
 320                                                         tb->zeroes_num > ih_item_len(ih) ? ih_item_len(ih) : tb->zeroes_num);
 321
 322                                         version = ih_version(ih);
 323
 324                                         /* Calculate key component, item length and body to insert into S[0] */
 325                                         set_le_ih_k_offset(ih, le_ih_k_offset(ih) +
 326                                                         (tb->lbytes << (is_indirect_le_ih(ih) ? tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT : 0)));
 327
 328                                         put_ih_item_len(ih, new_item_len);
 329                                         if (tb->lbytes > tb->zeroes_num) {
 330                                                 body += (tb->lbytes - tb->zeroes_num);
 331                                                 tb->zeroes_num = 0;
 332                                         } else
 333                                                 tb->zeroes_num -= tb->lbytes;
 334
 335                                         RFALSE(ih_item_len(ih) <= 0,
 336                                                "PAP-12085: there is nothing to insert into S[0]: ih_item_len=%d",
 337                                                ih_item_len(ih));
 338                                 } else {
 339                                         /* new item in whole falls into L[0] */
 340                                         /* Shift lnum[0]-1 items to L[0] */
 341                                         ret_val = leaf_shift_left(tb, tb->lnum[0] - 1, tb->lbytes);
 342                                         /* Insert new item into L[0] */
 343                                         buffer_info_init_left(tb, &bi);
 344                                         leaf_insert_into_buf(&bi, n + tb->item_pos - ret_val, ih, body, tb->zeroes_num);
 345                                         tb->insert_size[0] = 0;
 346                                         tb->zeroes_num = 0;
 347                                 }
 348
 349 }
 350
 351 /**
 352  * balance_leaf - reiserfs tree balancing algorithm
 353  * @tb: tree balance state
 354  * @ih: item header of inserted item (little endian)
 355  * @body: body of inserted item or bytes to paste
 356  * @flag: i - insert, d - delete, c - cut, p - paste (see do_balance)
 357  * passed back:
 358  * @insert_key: key to insert new nodes
 359  * @insert_ptr: array of nodes to insert at the next level
 360  *
 361  * In our processing of one level we sometimes determine what must be
 362  * inserted into the next higher level.  This insertion consists of a
 363  * key or two keys and their corresponding pointers.
 364  */
 365 static int balance_leaf(struct tree_balance *tb, struct item_head *ih,
 366                         const char *body, int flag,
 367                         struct item_head *insert_key,
 368                         struct buffer_head **insert_ptr)
 369 {
 370         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
 371         struct buffer_info bi;
 372         int n, i;
 373         int ret_val;
 374
 375         PROC_INFO_INC(tb->tb_sb, balance_at[0]);
 376
 377         /* Make balance in case insert_size[0] < 0 */
 378         if (tb->insert_size[0] < 0)
 379                 return balance_leaf_when_delete(tb, flag);
 380
 381         tb->item_pos = PATH_LAST_POSITION(tb->tb_path),
 382         tb->pos_in_item = tb->tb_path->pos_in_item,
 383         tb->zeroes_num = 0;
 384         if (flag == M_INSERT && !body)
 385                 tb->zeroes_num = ih_item_len(ih);
 386
 387         /*
 388          * for indirect item pos_in_item is measured in unformatted node
 389          * pointers. Recalculate to bytes
 390          */
 391         if (flag != M_INSERT
 392             && is_indirect_le_ih(item_head(tbS0, tb->item_pos)))
 393                 tb->pos_in_item *= UNFM_P_SIZE;
 394
 395         if (tb->lnum[0] > 0) {
 396                 /* Shift lnum[0] items from S[0] to the left neighbor L[0] */
 397                 if (tb->item_pos < tb->lnum[0]) {
 398                         /* new item or it part falls to L[0], shift it too */
 399                         n = B_NR_ITEMS(tb->L[0]);
 400
 401                         switch (flag) {
 402                         case M_INSERT:  /* insert item into L[0] */
 403                                 balance_leaf_insert_left(tb, ih, body);
 404                                 break;
 405
 406                         case M_PASTE:   /* append item in L[0] */
 407
 408                                 if (tb->item_pos == tb->lnum[0] - 1 && tb->lbytes != -1) {
 409                                         /* we must shift the part of the appended item */
 410                                         if (is_direntry_le_ih(item_head(tbS0, tb->item_pos))) {
 411
 412                                                 RFALSE(tb->zeroes_num,
 413                                                        "PAP-12090: invalid parameter in case of a directory");
 414                                                 /* directory item */
 415                                                 if (tb->lbytes > tb->pos_in_item) {
 416                                                         /* new directory entry falls into L[0] */
 417                                                         struct item_head *pasted;
 418                                                         int l_pos_in_item = tb->pos_in_item;
 419
 420                                                         /* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 entries from given directory item */
 421                                                         ret_val = leaf_shift_left(tb, tb->lnum[0], tb->lbytes-1);
 422                                                         if (ret_val && !tb->item_pos) {
 423                                                                 pasted = item_head(tb->L[0], B_NR_ITEMS(tb->L[0]) - 1);
 424                                                                 l_pos_in_item += ih_entry_count(pasted) - (tb->lbytes -1);
 425                                                         }
 426
 427                                                         /* Append given directory entry to directory item */
 428                                                         buffer_info_init_left(tb, &bi);
 429                                                         leaf_paste_in_buffer(&bi, n + tb->item_pos - ret_val, l_pos_in_item, tb->insert_size[0], body, tb->zeroes_num);
 430
 431                                                         /* previous string prepared space for pasting new entry, following string pastes this entry */
 432
 433                                                         /* when we have merge directory item, pos_in_item has been changed too */
 434
 435                                                         /* paste new directory entry. 1 is entry number */
 436                                                         leaf_paste_entries(&bi, n + tb->item_pos - ret_val, l_pos_in_item,
 437                                                                            1, (struct reiserfs_de_head *) body,
 438                                                                            body + DEH_SIZE, tb->insert_size[0]);
 439                                                         tb->insert_size[0] = 0;
 440                                                 } else {
 441                                                         /* new directory item doesn't fall into L[0] */
 442                                                         /* Shift lnum[0]-1 items in whole. Shift lbytes directory entries from directory item number lnum[0] */
 443                                                         leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
 444                                                 }
 445                                                 /* Calculate new position to append in item body */
 446                                                 tb->pos_in_item -= tb->lbytes;
 447                                         } else {
 448                                                 /* regular object */
 449                                                 RFALSE(tb->lbytes <= 0, "PAP-12095: there is nothing to shift to L[0]. lbytes=%d", tb->lbytes);
 450                                                 RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)),
 451                                                        "PAP-12100: incorrect position to paste: item_len=%d, pos_in_item=%d",
 452                                                        ih_item_len(item_head(tbS0, tb->item_pos)), tb->pos_in_item);
 453
 454                                                 if (tb->lbytes >= tb->pos_in_item) {
 455                                                         /* appended item will be in L[0] in whole */
 456                                                         int l_n;
 457
 458                                                         /* this bytes number must be appended to the last item of L[h] */
 459                                                         l_n = tb->lbytes - tb->pos_in_item;
 460
 461                                                         /* Calculate new insert_size[0] */
 462                                                         tb->insert_size[0] -= l_n;
 463
 464                                                         RFALSE(tb->insert_size[0] <= 0,
 465                                                                "PAP-12105: there is nothing to paste into L[0]. insert_size=%d",
 466                                                                tb->insert_size[0]);
 467                                                         ret_val = leaf_shift_left(tb, tb->lnum[0], ih_item_len
 468                                                                             (item_head(tbS0, tb->item_pos)));
 469                                                         /* Append to body of item in L[0] */
 470                                                         buffer_info_init_left(tb, &bi);
 471                                                         leaf_paste_in_buffer
 472                                                             (&bi, n + tb->item_pos - ret_val, ih_item_len
 473                                                              (item_head(tb->L[0], n + tb->item_pos - ret_val)),
 474                                                              l_n, body,
 475                                                              tb->zeroes_num > l_n ? l_n : tb->zeroes_num);
 476                                                         /* 0-th item in S0 can be only of DIRECT type when l_n != 0 */
 477                                                         {
 478                                                                 int version;
 479                                                                 int temp_l = l_n;
 480
 481                                                                 RFALSE(ih_item_len(item_head(tbS0, 0)),
 482                                                                      "PAP-12106: item length must be 0");
 483                                                                 RFALSE(comp_short_le_keys(leaf_key(tbS0, 0), leaf_key
 484                                                                       (tb->L[0], n + tb->item_pos - ret_val)),
 485                                                                      "PAP-12107: items must be of the same file");
 486                                                                 if (is_indirect_le_ih(item_head(tb->L[0], n + tb->item_pos - ret_val))) {
 487                                                                         temp_l = l_n << (tb->tb_sb-> s_blocksize_bits - UNFM_P_SHIFT);
 488                                                                 }
 489                                                                 /* update key of first item in S0 */
 490                                                                 version = ih_version(item_head(tbS0, 0));
 491                                                                 set_le_key_k_offset(version, leaf_key(tbS0, 0),
 492                                                                      le_key_k_offset(version,leaf_key(tbS0, 0)) + temp_l);
 493                                                                 /* update left delimiting key */
 494                                                                 set_le_key_k_offset(version, internal_key(tb->CFL[0], tb->lkey[0]),
 495                                                                      le_key_k_offset(version, internal_key(tb->CFL[0], tb->lkey[0])) + temp_l);
 496                                                         }
 497
 498                                                         /* Calculate new body, position in item and insert_size[0] */
 499                                                         if (l_n > tb->zeroes_num) {
 500                                                                 body += (l_n - tb->zeroes_num);
 501                                                                 tb->zeroes_num = 0;
 502                                                         } else
 503                                                                 tb->zeroes_num -= l_n;
 504                                                         tb->pos_in_item = 0;
 505
 506                                                         RFALSE(comp_short_le_keys(leaf_key(tbS0, 0), leaf_key(tb->L[0], B_NR_ITEMS(tb->L[0]) - 1))
 507                                                              || !op_is_left_mergeable(leaf_key(tbS0, 0), tbS0->b_size)
 508                                                              || !op_is_left_mergeable(internal_key(tb->CFL[0], tb->lkey[0]), tbS0->b_size),
 509                                                              "PAP-12120: item must be merge-able with left neighboring item");
 510                                                 } else {        /* only part of the appended item will be in L[0] */
 511
 512                                                         /* Calculate position in item for append in S[0] */
 513                                                         tb->pos_in_item -= tb->lbytes;
 514
 515                                                         RFALSE(tb->pos_in_item <= 0, "PAP-12125: no place for paste. pos_in_item=%d", tb->pos_in_item);
 516
 517                                                         /* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 byte from item number lnum[0] */
 518                                                         leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
 519                                                 }
 520                                         }
 521                                 } else {        /* appended item will be in L[0] in whole */
 522
 523                                         struct item_head *pasted;
 524
 525                                         if (!tb->item_pos && op_is_left_mergeable(leaf_key(tbS0, 0), tbS0->b_size)) {   /* if we paste into first item of S[0] and it is left mergable */
 526                                                 /* then increment pos_in_item by the size of the last item in L[0] */
 527                                                 pasted = item_head(tb->L[0], n - 1);
 528                                                 if (is_direntry_le_ih(pasted))
 529                                                         tb->pos_in_item += ih_entry_count(pasted);
 530                                                 else
 531                                                         tb->pos_in_item += ih_item_len(pasted);
 532                                         }
 533
 534                                         /* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 byte from item number lnum[0] */
 535                                         ret_val = leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
 536                                         /* Append to body of item in L[0] */
 537                                         buffer_info_init_left(tb, &bi);
 538                                         leaf_paste_in_buffer(&bi, n + tb->item_pos - ret_val,
 539                                                              tb->pos_in_item,
 540                                                              tb->insert_size[0],
 541                                                              body, tb->zeroes_num);
 542
 543                                         /* if appended item is directory, paste entry */
 544                                         pasted = item_head(tb->L[0], n + tb->item_pos - ret_val);
 545                                         if (is_direntry_le_ih(pasted))
 546                                                 leaf_paste_entries(&bi, n + tb->item_pos - ret_val,
 547                                                                    tb->pos_in_item, 1,
 548                                                                    (struct reiserfs_de_head *) body,
 549                                                                    body + DEH_SIZE,
 550                                                                    tb->insert_size[0]);
 551                                         /* if appended item is indirect item, put unformatted node into un list */
 552                                         if (is_indirect_le_ih(pasted))
 553                                                 set_ih_free_space(pasted, 0);
 554                                         tb->insert_size[0] = 0;
 555                                         tb->zeroes_num = 0;
 556                                 }
 557                                 break;
 558                         default:        /* cases d and t */
 559                                 reiserfs_panic(tb->tb_sb, "PAP-12130",
 560                                                "lnum > 0: unexpected mode: "
 561                                                " %s(%d)",
 562                                                (flag == M_DELETE) ? "DELETE" : ((flag == M_CUT) ? "CUT" : "UNKNOWN"), flag);
 563                         }
 564                 } else {
 565                         /* new item doesn't fall into L[0] */
 566                         leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
 567                 }
 568         }
 569
 570         /* tb->lnum[0] > 0 */
 571         /* Calculate new item position */
 572         tb->item_pos -= (tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0));
 573
 574         if (tb->rnum[0] > 0) {
 575                 /* shift rnum[0] items from S[0] to the right neighbor R[0] */
 576                 n = B_NR_ITEMS(tbS0);
 577                 switch (flag) {
 578
 579                 case M_INSERT:  /* insert item */
 580                         if (n - tb->rnum[0] < tb->item_pos) {   /* new item or its part falls to R[0] */
 581                                 if (tb->item_pos == n - tb->rnum[0] + 1 && tb->rbytes != -1) {  /* part of new item falls into R[0] */
 582                                         loff_t old_key_comp, old_len, r_zeroes_number;
 583                                         const char *r_body;
 584                                         int version;
 585                                         loff_t offset;
 586
 587                                         leaf_shift_right(tb, tb->rnum[0] - 1, -1);
 588
 589                                         version = ih_version(ih);
 590                                         /* Remember key component and item length */
 591                                         old_key_comp = le_ih_k_offset(ih);
 592                                         old_len = ih_item_len(ih);
 593
 594                                         /* Calculate key component and item length to insert into R[0] */
 595                                         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));
 596                                         set_le_ih_k_offset(ih, offset);
 597                                         put_ih_item_len(ih, tb->rbytes);
 598                                         /* Insert part of the item into R[0] */
 599                                         buffer_info_init_right(tb, &bi);
 600                                         if ((old_len - tb->rbytes) > tb->zeroes_num) {
 601                                                 r_zeroes_number = 0;
 602                                                 r_body = body + (old_len - tb->rbytes) - tb->zeroes_num;
 603                                         } else {
 604                                                 r_body = body;
 605                                                 r_zeroes_number = tb->zeroes_num - (old_len - tb->rbytes);
 606                                                 tb->zeroes_num -= r_zeroes_number;
 607                                         }
 608
 609                                         leaf_insert_into_buf(&bi, 0, ih, r_body,
 610                                                              r_zeroes_number);
 611
 612                                         /* Replace right delimiting key by first key in R[0] */
 613                                         replace_key(tb, tb->CFR[0], tb->rkey[0],
 614                                                     tb->R[0], 0);
 615
 616                                         /* Calculate key component and item length to insert into S[0] */
 617                                         set_le_ih_k_offset(ih, old_key_comp);
 618                                         put_ih_item_len(ih, old_len - tb->rbytes);
 619
 620                                         tb->insert_size[0] -= tb->rbytes;
 621
 622                                 } else {        /* whole new item falls into R[0] */
 623
 624                                         /* Shift rnum[0]-1 items to R[0] */
 625                                         ret_val = leaf_shift_right(tb, tb->rnum[0] - 1, tb->rbytes);
 626                                         /* Insert new item into R[0] */
 627                                         buffer_info_init_right(tb, &bi);
 628                                         leaf_insert_into_buf(&bi, tb->item_pos - n + tb->rnum[0] - 1,
 629                                                              ih, body, tb->zeroes_num);
 630
 631                                         if (tb->item_pos - n + tb->rnum[0] - 1 == 0) {
 632                                                 replace_key(tb, tb->CFR[0],
 633                                                             tb->rkey[0],
 634                                                             tb->R[0], 0);
 635
 636                                         }
 637                                         tb->zeroes_num = tb->insert_size[0] = 0;
 638                                 }
 639                         } else {        /* new item or part of it doesn't fall into R[0] */
 640
 641                                 leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
 642                         }
 643                         break;
 644
 645                 case M_PASTE:   /* append item */
 646
 647                         if (n - tb->rnum[0] <= tb->item_pos) {  /* pasted item or part of it falls to R[0] */
 648                                 if (tb->item_pos == n - tb->rnum[0] && tb->rbytes != -1) {      /* we must shift the part of the appended item */
 649                                         if (is_direntry_le_ih(item_head(tbS0, tb->item_pos))) { /* we append to directory item */
 650                                                 int entry_count;
 651
 652                                                 RFALSE(tb->zeroes_num,
 653                                                        "PAP-12145: invalid parameter in case of a directory");
 654                                                 entry_count = ih_entry_count(item_head
 655                                                                   (tbS0, tb->item_pos));
 656                                                 if (entry_count - tb->rbytes <
 657                                                     tb->pos_in_item)
 658                                                         /* new directory entry falls into R[0] */
 659                                                 {
 660                                                         int paste_entry_position;
 661
 662                                                         RFALSE(tb->rbytes - 1 >= entry_count || !tb-> insert_size[0],
 663                                                                "PAP-12150: no enough of entries to shift to R[0]: rbytes=%d, entry_count=%d",
 664                                                                tb->rbytes, entry_count);
 665                                                         /* Shift rnum[0]-1 items in whole. Shift rbytes-1 directory entries from directory item number rnum[0] */
 666                                                         leaf_shift_right(tb, tb->rnum[0], tb->rbytes - 1);
 667                                                         /* Paste given directory entry to directory item */
 668                                                         paste_entry_position = tb->pos_in_item - entry_count + tb->rbytes - 1;
 669                                                         buffer_info_init_right(tb, &bi);
 670                                                         leaf_paste_in_buffer(&bi, 0, paste_entry_position, tb->insert_size[0], body, tb->zeroes_num);
 671                                                         /* paste entry */
 672                                                         leaf_paste_entries(&bi, 0, paste_entry_position, 1,
 673                                                                            (struct reiserfs_de_head *) body,
 674                                                                            body + DEH_SIZE, tb->insert_size[0]);
 675
 676                                                         if (paste_entry_position == 0) {
 677                                                                 /* change delimiting keys */
 678                                                                 replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0],0);
 679                                                         }
 680
 681                                                         tb->insert_size[0] = 0;
 682                                                         tb->pos_in_item++;
 683                                                 } else {        /* new directory entry doesn't fall into R[0] */
 684
 685                                                         leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
 686                                                 }
 687                                         } else {        /* regular object */
 688
 689                                                 int n_shift, n_rem, r_zeroes_number;
 690                                                 const char *r_body;
 691
 692                                                 /* Calculate number of bytes which must be shifted from appended item */
 693                                                 if ((n_shift = tb->rbytes - tb->insert_size[0]) < 0)
 694                                                         n_shift = 0;
 695
 696                                                 RFALSE(tb->pos_in_item != ih_item_len
 697                                                        (item_head(tbS0, tb->item_pos)),
 698                                                        "PAP-12155: invalid position to paste. ih_item_len=%d, pos_in_item=%d",
 699                                                        tb->pos_in_item, ih_item_len
 700                                                        (item_head(tbS0, tb->item_pos)));
 701
 702                                                 leaf_shift_right(tb, tb->rnum[0], n_shift);
 703                                                 /* Calculate number of bytes which must remain in body after appending to R[0] */
 704                                                 if ((n_rem = tb->insert_size[0] - tb->rbytes) < 0)
 705                                                         n_rem = 0;
 706
 707                                                 {
 708                                                         int version;
 709                                                         unsigned long temp_rem = n_rem;
 710
 711                                                         version = ih_version(item_head(tb->R[0], 0));
 712                                                         if (is_indirect_le_key(version, leaf_key(tb->R[0], 0))) {
 713                                                                 temp_rem = n_rem << (tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT);
 714                                                         }
 715                                                         set_le_key_k_offset(version, leaf_key(tb->R[0], 0),
 716                                                              le_key_k_offset(version, leaf_key(tb->R[0], 0)) + temp_rem);
 717                                                         set_le_key_k_offset(version, internal_key(tb->CFR[0], tb->rkey[0]),
 718                                                              le_key_k_offset(version, internal_key(tb->CFR[0], tb->rkey[0])) + temp_rem);
 719                                                 }
 720 /*                k_offset (leaf_key(tb->R[0],0)) += n_rem;
 721                   k_offset (internal_key(tb->CFR[0],tb->rkey[0])) += n_rem;*/
 722                                                 do_balance_mark_internal_dirty(tb, tb->CFR[0], 0);
 723
 724                                                 /* Append part of body into R[0] */
 725                                                 buffer_info_init_right(tb, &bi);
 726                                                 if (n_rem > tb->zeroes_num) {
 727                                                         r_zeroes_number = 0;
 728                                                         r_body = body + n_rem - tb->zeroes_num;
 729                                                 } else {
 730                                                         r_body = body;
 731                                                         r_zeroes_number = tb->zeroes_num - n_rem;
 732                                                         tb->zeroes_num -= r_zeroes_number;
 733                                                 }
 734
 735                                                 leaf_paste_in_buffer(&bi, 0, n_shift,
 736                                                                      tb->insert_size[0] - n_rem,
 737                                                                      r_body, r_zeroes_number);
 738
 739                                                 if (is_indirect_le_ih(item_head(tb->R[0], 0))) {
 740 #if 0
 741                                                         RFALSE(n_rem,
 742                                                                "PAP-12160: paste more than one unformatted node pointer");
 743 #endif
 744                                                         set_ih_free_space(item_head(tb->R[0], 0), 0);
 745                                                 }
 746                                                 tb->insert_size[0] = n_rem;
 747                                                 if (!n_rem)
 748                                                         tb->pos_in_item++;
 749                                         }
 750                                 } else {        /* pasted item in whole falls into R[0] */
 751
 752                                         struct item_head *pasted;
 753
 754                                         ret_val = leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
 755                                         /* append item in R[0] */
 756                                         if (tb->pos_in_item >= 0) {
 757                                                 buffer_info_init_right(tb, &bi);
 758                                                 leaf_paste_in_buffer(&bi, tb->item_pos - n + tb->rnum[0], tb->pos_in_item,
 759                                                                      tb->insert_size[0], body, tb->zeroes_num);
 760                                         }
 761
 762                                         /* paste new entry, if item is directory item */
 763                                         pasted = item_head(tb->R[0], tb->item_pos - n + tb->rnum[0]);
 764                                         if (is_direntry_le_ih(pasted) && tb->pos_in_item >= 0) {
 765                                                 leaf_paste_entries(&bi, tb->item_pos - n + tb->rnum[0],
 766                                                                    tb->pos_in_item, 1,
 767                                                                    (struct reiserfs_de_head *) body,
 768                                                                    body + DEH_SIZE, tb->insert_size[0]);
 769                                                 if (!tb->pos_in_item) {
 770
 771                                                         RFALSE(tb->item_pos - n + tb->rnum[0],
 772                                                                "PAP-12165: directory item must be first item of node when pasting is in 0th position");
 773
 774                                                         /* update delimiting keys */
 775                                                         replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
 776                                                 }
 777                                         }
 778
 779                                         if (is_indirect_le_ih(pasted))
 780                                                 set_ih_free_space(pasted, 0);
 781                                         tb->zeroes_num = tb->insert_size[0] = 0;
 782                                 }
 783                         } else {        /* new item doesn't fall into R[0] */
 784
 785                                 leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
 786                         }
 787                         break;
 788                 default:        /* cases d and t */
 789                         reiserfs_panic(tb->tb_sb, "PAP-12175",
 790                                        "rnum > 0: unexpected mode: %s(%d)",
 791                                        (flag == M_DELETE) ? "DELETE" : ((flag == M_CUT) ? "CUT" : "UNKNOWN"), flag);
 792                 }
 793
 794         }
 795
 796         /* tb->rnum[0] > 0 */
 797         RFALSE(tb->blknum[0] > 3,
 798                "PAP-12180: blknum can not be %d. It must be <= 3", tb->blknum[0]);
 799         RFALSE(tb->blknum[0] < 0,
 800                "PAP-12185: blknum can not be %d. It must be >= 0", tb->blknum[0]);
 801
 802         /*
 803          * if while adding to a node we discover that it is possible to split
 804          * it in two, and merge the left part into the left neighbor and the
 805          * right part into the right neighbor, eliminating the node
 806          */
 807         if (tb->blknum[0] == 0) {       /* node S[0] is empty now */
 808
 809                 RFALSE(!tb->lnum[0] || !tb->rnum[0],
 810                        "PAP-12190: lnum and rnum must not be zero");
 811                 /*
 812                  * if insertion was done before 0-th position in R[0], right
 813                  * delimiting key of the tb->L[0]'s and left delimiting key are
 814                  * not set correctly
 815                  */
 816                 if (tb->CFL[0]) {
 817                         if (!tb->CFR[0])
 818                                 reiserfs_panic(tb->tb_sb, "vs-12195",
 819                                                "CFR not initialized");
 820                         copy_key(internal_key(tb->CFL[0], tb->lkey[0]),
 821                                  internal_key(tb->CFR[0], tb->rkey[0]));
 822                         do_balance_mark_internal_dirty(tb, tb->CFL[0], 0);
 823                 }
 824
 825                 reiserfs_invalidate_buffer(tb, tbS0);
 826                 return 0;
 827         }
 828
 829         /* Fill new nodes that appear in place of S[0] */
 830         for (i = tb->blknum[0] - 2; i >= 0; i--) {
 831
 832                 RFALSE(!tb->snum[i],
 833                        "PAP-12200: snum[%d] == %d. Must be > 0", i,
 834                        tb->snum[i]);
 835
 836                 /* here we shift from S to S_new nodes */
 837
 838                 tb->S_new[i] = get_FEB(tb);
 839
 840                 /* initialized block type and tree level */
 841                 set_blkh_level(B_BLK_HEAD(tb->S_new[i]), DISK_LEAF_NODE_LEVEL);
 842
 843                 n = B_NR_ITEMS(tbS0);
 844
 845                 switch (flag) {
 846                 case M_INSERT:  /* insert item */
 847
 848                         if (n - tb->snum[i] < tb->item_pos) {   /* new item or it's part falls to first new node S_new[i] */
 849                                 if (tb->item_pos == n - tb->snum[i] + 1 && tb->sbytes[i] != -1) {       /* part of new item falls into S_new[i] */
 850                                         int old_key_comp, old_len, r_zeroes_number;
 851                                         const char *r_body;
 852                                         int version;
 853
 854                                         /* Move snum[i]-1 items from S[0] to S_new[i] */
 855                                         leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
 856                                                         tb->snum[i] - 1, -1,
 857                                                         tb->S_new[i]);
 858                                         /* Remember key component and item length */
 859                                         version = ih_version(ih);
 860                                         old_key_comp = le_ih_k_offset(ih);
 861                                         old_len = ih_item_len(ih);
 862
 863                                         /* Calculate key component and item length to insert into S_new[i] */
 864                                         set_le_ih_k_offset(ih, le_ih_k_offset(ih) +
 865                                                            ((old_len - tb->sbytes[i]) << (is_indirect_le_ih(ih) ? tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT : 0)));
 866
 867                                         put_ih_item_len(ih, tb->sbytes[i]);
 868
 869                                         /* Insert part of the item into S_new[i] before 0-th item */
 870                                         buffer_info_init_bh(tb, &bi, tb->S_new[i]);
 871
 872                                         if ((old_len - tb->sbytes[i]) > tb->zeroes_num) {
 873                                                 r_zeroes_number = 0;
 874                                                 r_body = body + (old_len - tb->sbytes[i]) - tb->zeroes_num;
 875                                         } else {
 876                                                 r_body = body;
 877                                                 r_zeroes_number = tb->zeroes_num - (old_len - tb->sbytes[i]);
 878                                                 tb->zeroes_num -= r_zeroes_number;
 879                                         }
 880
 881                                         leaf_insert_into_buf(&bi, 0, ih, r_body, r_zeroes_number);
 882
 883                                         /* Calculate key component and item length to insert into S[i] */
 884                                         set_le_ih_k_offset(ih, old_key_comp);
 885                                         put_ih_item_len(ih, old_len - tb->sbytes[i]);
 886                                         tb->insert_size[0] -= tb->sbytes[i];
 887                                 } else {        /* whole new item falls into S_new[i] */
 888
 889                                         /* Shift snum[0] - 1 items to S_new[i] (sbytes[i] of split item) */
 890                                         leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
 891                                                         tb->snum[i] - 1, tb->sbytes[i], tb->S_new[i]);
 892
 893                                         /* Insert new item into S_new[i] */
 894                                         buffer_info_init_bh(tb, &bi, tb->S_new[i]);
 895                                         leaf_insert_into_buf(&bi, tb->item_pos - n + tb->snum[i] - 1,
 896                                                              ih, body, tb->zeroes_num);
 897
 898                                         tb->zeroes_num = tb->insert_size[0] = 0;
 899                                 }
 900                         }
 901
 902                         else {  /* new item or it part don't falls into S_new[i] */
 903
 904                                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
 905                                                 tb->snum[i], tb->sbytes[i], tb->S_new[i]);
 906                         }
 907                         break;
 908
 909                 case M_PASTE:   /* append item */
 910
 911                         if (n - tb->snum[i] <= tb->item_pos) {  /* pasted item or part if it falls to S_new[i] */
 912                                 if (tb->item_pos == n - tb->snum[i] && tb->sbytes[i] != -1) {   /* we must shift part of the appended item */
 913                                         struct item_head *aux_ih;
 914
 915                                         RFALSE(ih, "PAP-12210: ih must be 0");
 916
 917                                         aux_ih = item_head(tbS0, tb->item_pos);
 918                                         if (is_direntry_le_ih(aux_ih)) {
 919                                                 /* we append to directory item */
 920
 921                                                 int entry_count;
 922
 923                                                 entry_count = ih_entry_count(aux_ih);
 924
 925                                                 if (entry_count - tb->sbytes[i] < tb->pos_in_item && tb->pos_in_item <= entry_count) {
 926                                                         /* new directory entry falls into S_new[i] */
 927
 928                                                         RFALSE(!tb->insert_size[0], "PAP-12215: insert_size is already 0");
 929                                                         RFALSE(tb->sbytes[i] - 1 >= entry_count,
 930                                                                "PAP-12220: there are no so much entries (%d), only %d",
 931                                                                tb->sbytes[i] - 1, entry_count);
 932
 933                                                         /* Shift snum[i]-1 items in whole. Shift sbytes[i] directory entries from directory item number snum[i] */
 934                                                         leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i], tb->sbytes[i] - 1, tb->S_new[i]);
 935                                                         /* Paste given directory entry to directory item */
 936                                                         buffer_info_init_bh(tb, &bi, tb->S_new[i]);
 937                                                         leaf_paste_in_buffer(&bi, 0, tb->pos_in_item - entry_count + tb->sbytes[i] - 1,
 938                                                              tb->insert_size[0], body, tb->zeroes_num);
 939                                                         /* paste new directory entry */
 940                                                         leaf_paste_entries(&bi, 0, tb->pos_in_item - entry_count + tb->sbytes[i] - 1, 1,
 941                                                                            (struct reiserfs_de_head *) body,
 942                                                                            body + DEH_SIZE, tb->insert_size[0]);
 943                                                         tb->insert_size[0] = 0;
 944                                                         tb->pos_in_item++;
 945                                                 } else {        /* new directory entry doesn't fall into S_new[i] */
 946                                                         leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i], tb->sbytes[i], tb->S_new[i]);
 947                                                 }
 948                                         } else {        /* regular object */
 949
 950                                                 int n_shift, n_rem, r_zeroes_number;
 951                                                 const char *r_body;
 952
 953                                                 RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)) || tb->insert_size[0] <= 0,
 954                                                        "PAP-12225: item too short or insert_size <= 0");
 955
 956                                                 /* Calculate number of bytes which must be shifted from appended item */
 957                                                 n_shift = tb->sbytes[i] - tb->insert_size[0];
 958                                                 if (n_shift < 0)
 959                                                         n_shift = 0;
 960                                                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i], n_shift, tb->S_new[i]);
 961
 962                                                 /* Calculate number of bytes which must remain in body after append to S_new[i] */
 963                                                 n_rem = tb->insert_size[0] - tb->sbytes[i];
 964                                                 if (n_rem < 0)
 965                                                         n_rem = 0;
 966                                                 /* Append part of body into S_new[0] */
 967                                                 buffer_info_init_bh(tb, &bi, tb->S_new[i]);
 968                                                 if (n_rem > tb->zeroes_num) {
 969                                                         r_zeroes_number = 0;
 970                                                         r_body = body + n_rem - tb->zeroes_num;
 971                                                 } else {
 972                                                         r_body = body;
 973                                                         r_zeroes_number = tb->zeroes_num - n_rem;
 974                                                         tb->zeroes_num -= r_zeroes_number;
 975                                                 }
 976
 977                                                 leaf_paste_in_buffer(&bi, 0, n_shift,
 978                                                                      tb->insert_size[0] - n_rem,
 979                                                                      r_body, r_zeroes_number);
 980                                                 {
 981                                                         struct item_head *tmp;
 982
 983                                                         tmp = item_head(tb->S_new[i], 0);
 984                                                         if (is_indirect_le_ih
 985                                                             (tmp)) {
 986                                                                 set_ih_free_space(tmp, 0);
 987                                                                 set_le_ih_k_offset(tmp, le_ih_k_offset(tmp) + (n_rem << (tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT)));
 988                                                         } else {
 989                                                                 set_le_ih_k_offset(tmp, le_ih_k_offset(tmp) + n_rem);
 990                                                         }
 991                                                 }
 992
 993                                                 tb->insert_size[0] = n_rem;
 994                                                 if (!n_rem)
 995                                                         tb->pos_in_item++;
 996                                         }
 997                                 } else
 998                                         /* item falls wholly into S_new[i] */
 999                                 {
1000                                         int leaf_mi;
1001                                         struct item_head *pasted;
1002
1003 #ifdef CONFIG_REISERFS_CHECK
1004                                         struct item_head *ih_check = item_head(tbS0, tb->item_pos);
1005
1006                                         if (!is_direntry_le_ih(ih_check)
1007                                             && (tb->pos_in_item != ih_item_len(ih_check)
1008                                                 || tb->insert_size[0] <= 0))
1009                                                 reiserfs_panic(tb->tb_sb,
1010                                                              "PAP-12235",
1011                                                              "pos_in_item "
1012                                                              "must be equal "
1013                                                              "to ih_item_len");
1014 #endif                          /* CONFIG_REISERFS_CHECK */
1015
1016                                         leaf_mi = leaf_move_items(LEAF_FROM_S_TO_SNEW,
1017                                                             tb, tb->snum[i],
1018                                                             tb->sbytes[i],
1019                                                             tb->S_new[i]);
1020
1021                                         RFALSE(leaf_mi,
1022                                                "PAP-12240: unexpected value returned by leaf_move_items (%d)",
1023                                                leaf_mi);
1024
1025                                         /* paste into item */
1026                                         buffer_info_init_bh(tb, &bi, tb->S_new[i]);
1027                                         leaf_paste_in_buffer(&bi,
1028                                                              tb->item_pos - n + tb->snum[i],
1029                                                              tb->pos_in_item,
1030                                                              tb->insert_size[0],
1031                                                              body, tb->zeroes_num);
1032
1033                                         pasted = item_head(tb->S_new[i], tb->item_pos - n + tb->snum[i]);
1034                                         if (is_direntry_le_ih(pasted)) {
1035                                                 leaf_paste_entries(&bi,
1036                                                                    tb->item_pos - n + tb->snum[i],
1037                                                                    tb->pos_in_item, 1,
1038                                                                    (struct reiserfs_de_head *)body,
1039                                                                    body + DEH_SIZE,
1040                                                                    tb->insert_size[0]
1041                                                     );
1042                                         }
1043
1044                                         /* if we paste to indirect item update ih_free_space */
1045                                         if (is_indirect_le_ih(pasted))
1046                                                 set_ih_free_space(pasted, 0);
1047                                         tb->zeroes_num = tb->insert_size[0] = 0;
1048                                 }
1049                         }
1050
1051                         else {  /* pasted item doesn't fall into S_new[i] */
1052
1053                                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
1054                                                 tb->snum[i], tb->sbytes[i], tb->S_new[i]);
1055                         }
1056                         break;
1057                 default:        /* cases d and t */
1058                         reiserfs_panic(tb->tb_sb, "PAP-12245",
1059                                        "blknum > 2: unexpected mode: %s(%d)",
1060                                        (flag == M_DELETE) ? "DELETE" : ((flag == M_CUT) ? "CUT" : "UNKNOWN"), flag);
1061                 }
1062
1063                 memcpy(insert_key + i, leaf_key(tb->S_new[i], 0), KEY_SIZE);
1064                 insert_ptr[i] = tb->S_new[i];
1065
1066                 RFALSE(!buffer_journaled(tb->S_new[i])
1067                        || buffer_journal_dirty(tb->S_new[i])
1068                        || buffer_dirty(tb->S_new[i]),
1069                        "PAP-12247: S_new[%d] : (%b)",
1070                        i, tb->S_new[i]);
1071         }
1072
1073         /* if the affected item was not wholly shifted then we perform all necessary operations on that part or whole of the
1074            affected item which remains in S */
1075         if (0 <= tb->item_pos && tb->item_pos < tb->s0num) {    /* if we must insert or append into buffer S[0] */
1076
1077                 switch (flag) {
1078                 case M_INSERT:  /* insert item into S[0] */
1079                         buffer_info_init_tbS0(tb, &bi);
1080                         leaf_insert_into_buf(&bi, tb->item_pos, ih,
1081                                              body, tb->zeroes_num);
1082
1083                         /* If we insert the first key change the delimiting key */
1084                         if (tb->item_pos == 0) {
1085                                 if (tb->CFL[0]) /* can be 0 in reiserfsck */
1086                                         replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
1087                         }
1088                         break;
1089
1090                 case M_PASTE:{  /* append item in S[0] */
1091                                 struct item_head *pasted;
1092
1093                                 pasted = item_head(tbS0, tb->item_pos);
1094                                 /* when directory, may be new entry already pasted */
1095                                 if (is_direntry_le_ih(pasted)) {
1096                                         if (tb->pos_in_item >= 0 && tb->pos_in_item <= ih_entry_count(pasted)) {
1097
1098                                                 RFALSE(!tb->insert_size[0],
1099                                                        "PAP-12260: insert_size is 0 already");
1100
1101                                                 /* prepare space */
1102                                                 buffer_info_init_tbS0(tb, &bi);
1103                                                 leaf_paste_in_buffer(&bi, tb->item_pos, tb->pos_in_item,
1104                                                                      tb->insert_size[0], body,
1105                                                                      tb->zeroes_num);
1106
1107                                                 /* paste entry */
1108                                                 leaf_paste_entries(&bi, tb->item_pos, tb->pos_in_item, 1,
1109                                                                    (struct reiserfs_de_head *)body,
1110                                                                    body + DEH_SIZE,
1111                                                                    tb->insert_size[0]);
1112                                                 if (!tb->item_pos && !tb->pos_in_item) {
1113                                                         RFALSE(!tb->CFL[0] || !tb->L[0],
1114                                                                "PAP-12270: CFL[0]/L[0] must be specified");
1115                                                         if (tb->CFL[0])
1116                                                                 replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
1117                                                 }
1118                                                 tb->insert_size[0] = 0;
1119                                         }
1120                                 } else {        /* regular object */
1121                                         if (tb->pos_in_item == ih_item_len(pasted)) {
1122
1123                                                 RFALSE(tb->insert_size[0] <= 0,
1124                                                        "PAP-12275: insert size must not be %d",
1125                                                        tb->insert_size[0]);
1126                                                 buffer_info_init_tbS0(tb, &bi);
1127                                                 leaf_paste_in_buffer(&bi, tb->item_pos, tb->pos_in_item,
1128                                                                      tb->insert_size[0], body, tb->zeroes_num);
1129
1130                                                 if (is_indirect_le_ih(pasted)) {
1131 #if 0
1132                                                         RFALSE(tb->
1133                                                                insert_size[0] !=
1134                                                                UNFM_P_SIZE,
1135                                                                "PAP-12280: insert_size for indirect item must be %d, not %d",
1136                                                                UNFM_P_SIZE,
1137                                                                tb->
1138                                                                insert_size[0]);
1139 #endif
1140                                                         set_ih_free_space(pasted, 0);
1141                                                 }
1142                                                 tb->insert_size[0] = 0;
1143                                         }
1144 #ifdef CONFIG_REISERFS_CHECK
1145                                         else {
1146                                                 if (tb->insert_size[0]) {
1147                                                         print_cur_tb("12285");
1148                                                         reiserfs_panic(tb->tb_sb,
1149                                                             "PAP-12285",
1150                                                             "insert_size "
1151                                                             "must be 0 "
1152                                                             "(%d)",
1153                                                             tb->insert_size[0]);
1154                                                 }
1155                                         }
1156 #endif                          /* CONFIG_REISERFS_CHECK */
1157
1158                                 }
1159                         }       /* case M_PASTE: */
1160                 }
1161         }
1162 #ifdef CONFIG_REISERFS_CHECK
1163         if (flag == M_PASTE && tb->insert_size[0]) {
1164                 print_cur_tb("12290");
1165                 reiserfs_panic(tb->tb_sb,
1166                                "PAP-12290", "insert_size is still not 0 (%d)",
1167                                tb->insert_size[0]);
1168         }
1169 #endif
1170
1171         /* Leaf level of the tree is balanced (end of balance_leaf) */
1172         return 0;
1173 }
1174
1175 /* Make empty node */
1176 void make_empty_node(struct buffer_info *bi)
1177 {
1178         struct block_head *blkh;
1179
1180         RFALSE(bi->bi_bh == NULL, "PAP-12295: pointer to the buffer is NULL");
1181
1182         blkh = B_BLK_HEAD(bi->bi_bh);
1183         set_blkh_nr_item(blkh, 0);
1184         set_blkh_free_space(blkh, MAX_CHILD_SIZE(bi->bi_bh));
1185
1186         if (bi->bi_parent)
1187                 B_N_CHILD(bi->bi_parent, bi->bi_position)->dc_size = 0; /* Endian safe if 0 */
1188 }
1189
1190 /* Get first empty buffer */
1191 struct buffer_head *get_FEB(struct tree_balance *tb)
1192 {
1193         int i;
1194         struct buffer_info bi;
1195
1196         for (i = 0; i < MAX_FEB_SIZE; i++)
1197                 if (tb->FEB[i] != NULL)
1198                         break;
1199
1200         if (i == MAX_FEB_SIZE)
1201                 reiserfs_panic(tb->tb_sb, "vs-12300", "FEB list is empty");
1202
1203         buffer_info_init_bh(tb, &bi, tb->FEB[i]);
1204         make_empty_node(&bi);
1205         set_buffer_uptodate(tb->FEB[i]);
1206         tb->used[i] = tb->FEB[i];
1207         tb->FEB[i] = NULL;
1208
1209         return tb->used[i];
1210 }
1211
1212 /* This is now used because reiserfs_free_block has to be able to schedule. */
1213 static void store_thrown(struct tree_balance *tb, struct buffer_head *bh)
1214 {
1215         int i;
1216
1217         if (buffer_dirty(bh))
1218                 reiserfs_warning(tb->tb_sb, "reiserfs-12320",
1219                                  "called with dirty buffer");
1220         for (i = 0; i < ARRAY_SIZE(tb->thrown); i++)
1221                 if (!tb->thrown[i]) {
1222                         tb->thrown[i] = bh;
1223                         get_bh(bh);     /* free_thrown puts this */
1224                         return;
1225                 }
1226         reiserfs_warning(tb->tb_sb, "reiserfs-12321",
1227                          "too many thrown buffers");
1228 }
1229
1230 static void free_thrown(struct tree_balance *tb)
1231 {
1232         int i;
1233         b_blocknr_t blocknr;
1234         for (i = 0; i < ARRAY_SIZE(tb->thrown); i++) {
1235                 if (tb->thrown[i]) {
1236                         blocknr = tb->thrown[i]->b_blocknr;
1237                         if (buffer_dirty(tb->thrown[i]))
1238                                 reiserfs_warning(tb->tb_sb, "reiserfs-12322",
1239                                                  "called with dirty buffer %d",
1240                                                  blocknr);
1241                         brelse(tb->thrown[i]);  /* incremented in store_thrown */
1242                         reiserfs_free_block(tb->transaction_handle, NULL,
1243                                             blocknr, 0);
1244                 }
1245         }
1246 }
1247
1248 void reiserfs_invalidate_buffer(struct tree_balance *tb, struct buffer_head *bh)
1249 {
1250         struct block_head *blkh;
1251         blkh = B_BLK_HEAD(bh);
1252         set_blkh_level(blkh, FREE_LEVEL);
1253         set_blkh_nr_item(blkh, 0);
1254
1255         clear_buffer_dirty(bh);
1256         store_thrown(tb, bh);
1257 }
1258
1259 /* Replace n_dest'th key in buffer dest by n_src'th key of buffer src.*/
1260 void replace_key(struct tree_balance *tb, struct buffer_head *dest, int n_dest,
1261                  struct buffer_head *src, int n_src)
1262 {
1263
1264         RFALSE(dest == NULL || src == NULL,
1265                "vs-12305: source or destination buffer is 0 (src=%p, dest=%p)",
1266                src, dest);
1267         RFALSE(!B_IS_KEYS_LEVEL(dest),
1268                "vs-12310: invalid level (%z) for destination buffer. dest must be leaf",
1269                dest);
1270         RFALSE(n_dest < 0 || n_src < 0,
1271                "vs-12315: src(%d) or dest(%d) key number < 0", n_src, n_dest);
1272         RFALSE(n_dest >= B_NR_ITEMS(dest) || n_src >= B_NR_ITEMS(src),
1273                "vs-12320: src(%d(%d)) or dest(%d(%d)) key number is too big",
1274                n_src, B_NR_ITEMS(src), n_dest, B_NR_ITEMS(dest));
1275
1276         if (B_IS_ITEMS_LEVEL(src))
1277                 /* source buffer contains leaf node */
1278                 memcpy(internal_key(dest, n_dest), item_head(src, n_src),
1279                        KEY_SIZE);
1280         else
1281                 memcpy(internal_key(dest, n_dest), internal_key(src, n_src),
1282                        KEY_SIZE);
1283
1284         do_balance_mark_internal_dirty(tb, dest, 0);
1285 }
1286
1287 int get_left_neighbor_position(struct tree_balance *tb, int h)
1288 {
1289         int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
1290
1291         RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FL[h] == NULL,
1292                "vs-12325: FL[%d](%p) or F[%d](%p) does not exist",
1293                h, tb->FL[h], h, PATH_H_PPARENT(tb->tb_path, h));
1294
1295         if (Sh_position == 0)
1296                 return B_NR_ITEMS(tb->FL[h]);
1297         else
1298                 return Sh_position - 1;
1299 }
1300
1301 int get_right_neighbor_position(struct tree_balance *tb, int h)
1302 {
1303         int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
1304
1305         RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FR[h] == NULL,
1306                "vs-12330: F[%d](%p) or FR[%d](%p) does not exist",
1307                h, PATH_H_PPARENT(tb->tb_path, h), h, tb->FR[h]);
1308
1309         if (Sh_position == B_NR_ITEMS(PATH_H_PPARENT(tb->tb_path, h)))
1310                 return 0;
1311         else
1312                 return Sh_position + 1;
1313 }
1314
1315 #ifdef CONFIG_REISERFS_CHECK
1316
1317 int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value);
1318 static void check_internal_node(struct super_block *s, struct buffer_head *bh,
1319                                 char *mes)
1320 {
1321         struct disk_child *dc;
1322         int i;
1323
1324         RFALSE(!bh, "PAP-12336: bh == 0");
1325
1326         if (!bh || !B_IS_IN_TREE(bh))
1327                 return;
1328
1329         RFALSE(!buffer_dirty(bh) &&
1330                !(buffer_journaled(bh) || buffer_journal_dirty(bh)),
1331                "PAP-12337: buffer (%b) must be dirty", bh);
1332         dc = B_N_CHILD(bh, 0);
1333
1334         for (i = 0; i <= B_NR_ITEMS(bh); i++, dc++) {
1335                 if (!is_reusable(s, dc_block_number(dc), 1)) {
1336                         print_cur_tb(mes);
1337                         reiserfs_panic(s, "PAP-12338",
1338                                        "invalid child pointer %y in %b",
1339                                        dc, bh);
1340                 }
1341         }
1342 }
1343
1344 static int locked_or_not_in_tree(struct tree_balance *tb,
1345                                   struct buffer_head *bh, char *which)
1346 {
1347         if ((!buffer_journal_prepared(bh) && buffer_locked(bh)) ||
1348             !B_IS_IN_TREE(bh)) {
1349                 reiserfs_warning(tb->tb_sb, "vs-12339", "%s (%b)", which, bh);
1350                 return 1;
1351         }
1352         return 0;
1353 }
1354
1355 static int check_before_balancing(struct tree_balance *tb)
1356 {
1357         int retval = 0;
1358
1359         if (REISERFS_SB(tb->tb_sb)->cur_tb) {
1360                 reiserfs_panic(tb->tb_sb, "vs-12335", "suspect that schedule "
1361                                "occurred based on cur_tb not being null at "
1362                                "this point in code. do_balance cannot properly "
1363                                "handle concurrent tree accesses on a same "
1364                                "mount point.");
1365         }
1366
1367         /*
1368          * double check that buffers that we will modify are unlocked.
1369          * (fix_nodes should already have prepped all of these for us).
1370          */
1371         if (tb->lnum[0]) {
1372                 retval |= locked_or_not_in_tree(tb, tb->L[0], "L[0]");
1373                 retval |= locked_or_not_in_tree(tb, tb->FL[0], "FL[0]");
1374                 retval |= locked_or_not_in_tree(tb, tb->CFL[0], "CFL[0]");
1375                 check_leaf(tb->L[0]);
1376         }
1377         if (tb->rnum[0]) {
1378                 retval |= locked_or_not_in_tree(tb, tb->R[0], "R[0]");
1379                 retval |= locked_or_not_in_tree(tb, tb->FR[0], "FR[0]");
1380                 retval |= locked_or_not_in_tree(tb, tb->CFR[0], "CFR[0]");
1381                 check_leaf(tb->R[0]);
1382         }
1383         retval |= locked_or_not_in_tree(tb, PATH_PLAST_BUFFER(tb->tb_path),
1384                                         "S[0]");
1385         check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
1386
1387         return retval;
1388 }
1389
1390 static void check_after_balance_leaf(struct tree_balance *tb)
1391 {
1392         if (tb->lnum[0]) {
1393                 if (B_FREE_SPACE(tb->L[0]) !=
1394                     MAX_CHILD_SIZE(tb->L[0]) -
1395                     dc_size(B_N_CHILD
1396                             (tb->FL[0], get_left_neighbor_position(tb, 0)))) {
1397                         print_cur_tb("12221");
1398                         reiserfs_panic(tb->tb_sb, "PAP-12355",
1399                                        "shift to left was incorrect");
1400                 }
1401         }
1402         if (tb->rnum[0]) {
1403                 if (B_FREE_SPACE(tb->R[0]) !=
1404                     MAX_CHILD_SIZE(tb->R[0]) -
1405                     dc_size(B_N_CHILD
1406                             (tb->FR[0], get_right_neighbor_position(tb, 0)))) {
1407                         print_cur_tb("12222");
1408                         reiserfs_panic(tb->tb_sb, "PAP-12360",
1409                                        "shift to right was incorrect");
1410                 }
1411         }
1412         if (PATH_H_PBUFFER(tb->tb_path, 1) &&
1413             (B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0)) !=
1414              (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
1415               dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
1416                                 PATH_H_POSITION(tb->tb_path, 1)))))) {
1417                 int left = B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0));
1418                 int right = (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
1419                              dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
1420                                                PATH_H_POSITION(tb->tb_path,
1421                                                                1))));
1422                 print_cur_tb("12223");
1423                 reiserfs_warning(tb->tb_sb, "reiserfs-12363",
1424                                  "B_FREE_SPACE (PATH_H_PBUFFER(tb->tb_path,0)) = %d; "
1425                                  "MAX_CHILD_SIZE (%d) - dc_size( %y, %d ) [%d] = %d",
1426                                  left,
1427                                  MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)),
1428                                  PATH_H_PBUFFER(tb->tb_path, 1),
1429                                  PATH_H_POSITION(tb->tb_path, 1),
1430                                  dc_size(B_N_CHILD
1431                                          (PATH_H_PBUFFER(tb->tb_path, 1),
1432                                           PATH_H_POSITION(tb->tb_path, 1))),
1433                                  right);
1434                 reiserfs_panic(tb->tb_sb, "PAP-12365", "S is incorrect");
1435         }
1436 }
1437
1438 static void check_leaf_level(struct tree_balance *tb)
1439 {
1440         check_leaf(tb->L[0]);
1441         check_leaf(tb->R[0]);
1442         check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
1443 }
1444
1445 static void check_internal_levels(struct tree_balance *tb)
1446 {
1447         int h;
1448
1449         /* check all internal nodes */
1450         for (h = 1; tb->insert_size[h]; h++) {
1451                 check_internal_node(tb->tb_sb, PATH_H_PBUFFER(tb->tb_path, h),
1452                                     "BAD BUFFER ON PATH");
1453                 if (tb->lnum[h])
1454                         check_internal_node(tb->tb_sb, tb->L[h], "BAD L");
1455                 if (tb->rnum[h])
1456                         check_internal_node(tb->tb_sb, tb->R[h], "BAD R");
1457         }
1458
1459 }
1460
1461 #endif
1462
1463 /*
1464  * Now we have all of the buffers that must be used in balancing of
1465  * the tree.  We rely on the assumption that schedule() will not occur
1466  * while do_balance works. ( Only interrupt handlers are acceptable.)
1467  * We balance the tree according to the analysis made before this,
1468  * using buffers already obtained.  For SMP support it will someday be
1469  * necessary to add ordered locking of tb.
1470  */
1471
1472 /*
1473  * Some interesting rules of balancing:
1474  * we delete a maximum of two nodes per level per balancing: we never
1475  * delete R, when we delete two of three nodes L, S, R then we move
1476  * them into R.
1477  *
1478  * we only delete L if we are deleting two nodes, if we delete only
1479  * one node we delete S
1480  *
1481  * if we shift leaves then we shift as much as we can: this is a
1482  * deliberate policy of extremism in node packing which results in
1483  * higher average utilization after repeated random balance operations
1484  * at the cost of more memory copies and more balancing as a result of
1485  * small insertions to full nodes.
1486  *
1487  * if we shift internal nodes we try to evenly balance the node
1488  * utilization, with consequent less balancing at the cost of lower
1489  * utilization.
1490  *
1491  * one could argue that the policy for directories in leaves should be
1492  * that of internal nodes, but we will wait until another day to
1493  * evaluate this....  It would be nice to someday measure and prove
1494  * these assumptions as to what is optimal....
1495  */
1496
1497 static inline void do_balance_starts(struct tree_balance *tb)
1498 {
1499         /* use print_cur_tb() to see initial state of struct tree_balance */
1500
1501         /* store_print_tb (tb); */
1502
1503         /* do not delete, just comment it out */
1504         /*
1505         print_tb(flag, PATH_LAST_POSITION(tb->tb_path),
1506                  tb->tb_path->pos_in_item, tb, "check");
1507         */
1508         RFALSE(check_before_balancing(tb), "PAP-12340: locked buffers in TB");
1509 #ifdef CONFIG_REISERFS_CHECK
1510         REISERFS_SB(tb->tb_sb)->cur_tb = tb;
1511 #endif
1512 }
1513
1514 static inline void do_balance_completed(struct tree_balance *tb)
1515 {
1516
1517 #ifdef CONFIG_REISERFS_CHECK
1518         check_leaf_level(tb);
1519         check_internal_levels(tb);
1520         REISERFS_SB(tb->tb_sb)->cur_tb = NULL;
1521 #endif
1522
1523         /*
1524          * reiserfs_free_block is no longer schedule safe.  So, we need to
1525          * put the buffers we want freed on the thrown list during do_balance,
1526          * and then free them now
1527          */
1528
1529         REISERFS_SB(tb->tb_sb)->s_do_balance++;
1530
1531         /* release all nodes hold to perform the balancing */
1532         unfix_nodes(tb);
1533
1534         free_thrown(tb);
1535 }
1536
1537 /*
1538  * do_balance - balance the tree
1539  *
1540  * @tb: tree_balance structure
1541  * @ih: item header of inserted item
1542  * @body: body of inserted item or bytes to paste
1543  * @flag: 'i' - insert, 'd' - delete, 'c' - cut, 'p' paste
1544  *
1545  * Cut means delete part of an item (includes removing an entry from a
1546  * directory).
1547  *
1548  * Delete means delete whole item.
1549  *
1550  * Insert means add a new item into the tree.
1551  *
1552  * Paste means to append to the end of an existing file or to
1553  * insert a directory entry.
1554  */
1555 void do_balance(struct tree_balance *tb, struct item_head *ih,
1556                 const char *body, int flag)
1557 {
1558         int child_pos;          /* position of a child node in its parent */
1559         int h;                  /* level of the tree being processed */
1560
1561         /*
1562          * in our processing of one level we sometimes determine what
1563          * must be inserted into the next higher level.  This insertion
1564          * consists of a key or two keys and their corresponding
1565          * pointers
1566          */
1567         struct item_head insert_key[2];
1568
1569         /* inserted node-ptrs for the next level */
1570         struct buffer_head *insert_ptr[2];
1571
1572         tb->tb_mode = flag;
1573         tb->need_balance_dirty = 0;
1574
1575         if (FILESYSTEM_CHANGED_TB(tb)) {
1576                 reiserfs_panic(tb->tb_sb, "clm-6000", "fs generation has "
1577                                "changed");
1578         }
1579         /* if we have no real work to do  */
1580         if (!tb->insert_size[0]) {
1581                 reiserfs_warning(tb->tb_sb, "PAP-12350",
1582                                  "insert_size == 0, mode == %c", flag);
1583                 unfix_nodes(tb);
1584                 return;
1585         }
1586
1587         atomic_inc(&fs_generation(tb->tb_sb));
1588         do_balance_starts(tb);
1589
1590         /*
1591          * balance_leaf returns 0 except if combining L R and S into
1592          * one node.  see balance_internal() for explanation of this
1593          * line of code.
1594          */
1595         child_pos = PATH_H_B_ITEM_ORDER(tb->tb_path, 0) +
1596             balance_leaf(tb, ih, body, flag, insert_key, insert_ptr);
1597
1598 #ifdef CONFIG_REISERFS_CHECK
1599         check_after_balance_leaf(tb);
1600 #endif
1601
1602         /* Balance internal level of the tree. */
1603         for (h = 1; h < MAX_HEIGHT && tb->insert_size[h]; h++)
1604                 child_pos =
1605                     balance_internal(tb, h, child_pos, insert_key, insert_ptr);
1606
1607         do_balance_completed(tb);
1608
1609 }