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TOMOYO Linux Cross Reference
Linux/fs/reiserfs/do_balan.c

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  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 <linux/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 
 77 static void balance_leaf_when_delete_del(struct tree_balance *tb)
 78 {
 79         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
 80         int item_pos = PATH_LAST_POSITION(tb->tb_path);
 81         struct buffer_info bi;
 82 #ifdef CONFIG_REISERFS_CHECK
 83         struct item_head *ih = item_head(tbS0, item_pos);
 84 #endif
 85 
 86         RFALSE(ih_item_len(ih) + IH_SIZE != -tb->insert_size[0],
 87                "vs-12013: mode Delete, insert size %d, ih to be deleted %h",
 88                -tb->insert_size[0], ih);
 89 
 90         buffer_info_init_tbS0(tb, &bi);
 91         leaf_delete_items(&bi, 0, item_pos, 1, -1);
 92 
 93         if (!item_pos && tb->CFL[0]) {
 94                 if (B_NR_ITEMS(tbS0)) {
 95                         replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
 96                 } else {
 97                         if (!PATH_H_POSITION(tb->tb_path, 1))
 98                                 replace_key(tb, tb->CFL[0], tb->lkey[0],
 99                                             PATH_H_PPARENT(tb->tb_path, 0), 0);
100                 }
101         }
102 
103         RFALSE(!item_pos && !tb->CFL[0],
104                "PAP-12020: tb->CFL[0]==%p, tb->L[0]==%p", tb->CFL[0],
105                tb->L[0]);
106 }
107 
108 /* cut item in S[0] */
109 static void balance_leaf_when_delete_cut(struct tree_balance *tb)
110 {
111         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
112         int item_pos = PATH_LAST_POSITION(tb->tb_path);
113         struct item_head *ih = item_head(tbS0, item_pos);
114         int pos_in_item = tb->tb_path->pos_in_item;
115         struct buffer_info bi;
116         buffer_info_init_tbS0(tb, &bi);
117 
118         if (is_direntry_le_ih(ih)) {
119                 /*
120                  * UFS unlink semantics are such that you can only
121                  * delete one directory entry at a time.
122                  *
123                  * when we cut a directory tb->insert_size[0] means
124                  * number of entries to be cut (always 1)
125                  */
126                 tb->insert_size[0] = -1;
127                 leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
128                                      -tb->insert_size[0]);
129 
130                 RFALSE(!item_pos && !pos_in_item && !tb->CFL[0],
131                        "PAP-12030: can not change delimiting key. CFL[0]=%p",
132                        tb->CFL[0]);
133 
134                 if (!item_pos && !pos_in_item && tb->CFL[0])
135                         replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
136         } else {
137                 leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
138                                      -tb->insert_size[0]);
139 
140                 RFALSE(!ih_item_len(ih),
141                        "PAP-12035: cut must leave non-zero dynamic "
142                        "length of item");
143         }
144 }
145 
146 static int balance_leaf_when_delete_left(struct tree_balance *tb)
147 {
148         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
149         int n = B_NR_ITEMS(tbS0);
150 
151         /* L[0] must be joined with S[0] */
152         if (tb->lnum[0] == -1) {
153                 /* R[0] must be also joined with S[0] */
154                 if (tb->rnum[0] == -1) {
155                         if (tb->FR[0] == PATH_H_PPARENT(tb->tb_path, 0)) {
156                                 /*
157                                  * all contents of all the
158                                  * 3 buffers will be in L[0]
159                                  */
160                                 if (PATH_H_POSITION(tb->tb_path, 1) == 0 &&
161                                     1 < B_NR_ITEMS(tb->FR[0]))
162                                         replace_key(tb, tb->CFL[0],
163                                                     tb->lkey[0], tb->FR[0], 1);
164 
165                                 leaf_move_items(LEAF_FROM_S_TO_L, tb, n, -1,
166                                                 NULL);
167                                 leaf_move_items(LEAF_FROM_R_TO_L, tb,
168                                                 B_NR_ITEMS(tb->R[0]), -1,
169                                                 NULL);
170 
171                                 reiserfs_invalidate_buffer(tb, tbS0);
172                                 reiserfs_invalidate_buffer(tb, tb->R[0]);
173 
174                                 return 0;
175                         }
176 
177                         /* all contents of all the 3 buffers will be in R[0] */
178                         leaf_move_items(LEAF_FROM_S_TO_R, tb, n, -1, NULL);
179                         leaf_move_items(LEAF_FROM_L_TO_R, tb,
180                                         B_NR_ITEMS(tb->L[0]), -1, NULL);
181 
182                         /* right_delimiting_key is correct in R[0] */
183                         replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
184 
185                         reiserfs_invalidate_buffer(tb, tbS0);
186                         reiserfs_invalidate_buffer(tb, tb->L[0]);
187 
188                         return -1;
189                 }
190 
191                 RFALSE(tb->rnum[0] != 0,
192                        "PAP-12045: rnum must be 0 (%d)", tb->rnum[0]);
193                 /* all contents of L[0] and S[0] will be in L[0] */
194                 leaf_shift_left(tb, n, -1);
195 
196                 reiserfs_invalidate_buffer(tb, tbS0);
197 
198                 return 0;
199         }
200 
201         /*
202          * a part of contents of S[0] will be in L[0] and
203          * the rest part of S[0] will be in R[0]
204          */
205 
206         RFALSE((tb->lnum[0] + tb->rnum[0] < n) ||
207                (tb->lnum[0] + tb->rnum[0] > n + 1),
208                "PAP-12050: rnum(%d) and lnum(%d) and item "
209                "number(%d) in S[0] are not consistent",
210                tb->rnum[0], tb->lnum[0], n);
211         RFALSE((tb->lnum[0] + tb->rnum[0] == n) &&
212                (tb->lbytes != -1 || tb->rbytes != -1),
213                "PAP-12055: bad rbytes (%d)/lbytes (%d) "
214                "parameters when items are not split",
215                tb->rbytes, tb->lbytes);
216         RFALSE((tb->lnum[0] + tb->rnum[0] == n + 1) &&
217                (tb->lbytes < 1 || tb->rbytes != -1),
218                "PAP-12060: bad rbytes (%d)/lbytes (%d) "
219                "parameters when items are split",
220                tb->rbytes, tb->lbytes);
221 
222         leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
223         leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
224 
225         reiserfs_invalidate_buffer(tb, tbS0);
226 
227         return 0;
228 }
229 
230 /*
231  * Balance leaf node in case of delete or cut: insert_size[0] < 0
232  *
233  * lnum, rnum can have values >= -1
234  *      -1 means that the neighbor must be joined with S
235  *       0 means that nothing should be done with the neighbor
236  *      >0 means to shift entirely or partly the specified number of items
237  *         to the neighbor
238  */
239 static int balance_leaf_when_delete(struct tree_balance *tb, int flag)
240 {
241         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
242         struct buffer_info bi;
243         int n;
244 
245         RFALSE(tb->FR[0] && B_LEVEL(tb->FR[0]) != DISK_LEAF_NODE_LEVEL + 1,
246                "vs- 12000: level: wrong FR %z", tb->FR[0]);
247         RFALSE(tb->blknum[0] > 1,
248                "PAP-12005: tb->blknum == %d, can not be > 1", tb->blknum[0]);
249         RFALSE(!tb->blknum[0] && !PATH_H_PPARENT(tb->tb_path, 0),
250                "PAP-12010: tree can not be empty");
251 
252         buffer_info_init_tbS0(tb, &bi);
253 
254         /* Delete or truncate the item */
255 
256         BUG_ON(flag != M_DELETE && flag != M_CUT);
257         if (flag == M_DELETE)
258                 balance_leaf_when_delete_del(tb);
259         else /* M_CUT */
260                 balance_leaf_when_delete_cut(tb);
261 
262 
263         /*
264          * the rule is that no shifting occurs unless by shifting
265          * a node can be freed
266          */
267         n = B_NR_ITEMS(tbS0);
268 
269 
270         /* L[0] takes part in balancing */
271         if (tb->lnum[0])
272                 return balance_leaf_when_delete_left(tb);
273 
274         if (tb->rnum[0] == -1) {
275                 /* all contents of R[0] and S[0] will be in R[0] */
276                 leaf_shift_right(tb, n, -1);
277                 reiserfs_invalidate_buffer(tb, tbS0);
278                 return 0;
279         }
280 
281         RFALSE(tb->rnum[0],
282                "PAP-12065: bad rnum parameter must be 0 (%d)", tb->rnum[0]);
283         return 0;
284 }
285 
286 static unsigned int balance_leaf_insert_left(struct tree_balance *tb,
287                                              struct item_head *const ih,
288                                              const char * const body)
289 {
290         int ret;
291         struct buffer_info bi;
292         int n = B_NR_ITEMS(tb->L[0]);
293         unsigned body_shift_bytes = 0;
294 
295         if (tb->item_pos == tb->lnum[0] - 1 && tb->lbytes != -1) {
296                 /* part of new item falls into L[0] */
297                 int new_item_len, shift;
298 
299                 ret = leaf_shift_left(tb, tb->lnum[0] - 1, -1);
300 
301                 /* Calculate item length to insert to S[0] */
302                 new_item_len = ih_item_len(ih) - tb->lbytes;
303 
304                 /* Calculate and check item length to insert to L[0] */
305                 put_ih_item_len(ih, ih_item_len(ih) - new_item_len);
306 
307                 RFALSE(ih_item_len(ih) <= 0,
308                        "PAP-12080: there is nothing to insert into L[0]: "
309                        "ih_item_len=%d", ih_item_len(ih));
310 
311                 /* Insert new item into L[0] */
312                 buffer_info_init_left(tb, &bi);
313                 leaf_insert_into_buf(&bi, n + tb->item_pos - ret, ih, body,
314                              min_t(int, tb->zeroes_num, ih_item_len(ih)));
315 
316                 /*
317                  * Calculate key component, item length and body to
318                  * insert into S[0]
319                  */
320                 shift = 0;
321                 if (is_indirect_le_ih(ih))
322                         shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
323 
324                 add_le_ih_k_offset(ih, tb->lbytes << shift);
325 
326                 put_ih_item_len(ih, new_item_len);
327                 if (tb->lbytes > tb->zeroes_num) {
328                         body_shift_bytes = tb->lbytes - tb->zeroes_num;
329                         tb->zeroes_num = 0;
330                 } else
331                         tb->zeroes_num -= tb->lbytes;
332 
333                 RFALSE(ih_item_len(ih) <= 0,
334                        "PAP-12085: there is nothing to insert into S[0]: "
335                        "ih_item_len=%d", ih_item_len(ih));
336         } else {
337                 /* new item in whole falls into L[0] */
338                 /* Shift lnum[0]-1 items to L[0] */
339                 ret = leaf_shift_left(tb, tb->lnum[0] - 1, tb->lbytes);
340 
341                 /* Insert new item into L[0] */
342                 buffer_info_init_left(tb, &bi);
343                 leaf_insert_into_buf(&bi, n + tb->item_pos - ret, ih, body,
344                                      tb->zeroes_num);
345                 tb->insert_size[0] = 0;
346                 tb->zeroes_num = 0;
347         }
348         return body_shift_bytes;
349 }
350 
351 static void balance_leaf_paste_left_shift_dirent(struct tree_balance *tb,
352                                                  struct item_head * const ih,
353                                                  const char * const body)
354 {
355         int n = B_NR_ITEMS(tb->L[0]);
356         struct buffer_info bi;
357 
358         RFALSE(tb->zeroes_num,
359                "PAP-12090: invalid parameter in case of a directory");
360 
361         /* directory item */
362         if (tb->lbytes > tb->pos_in_item) {
363                 /* new directory entry falls into L[0] */
364                 struct item_head *pasted;
365                 int ret, l_pos_in_item = tb->pos_in_item;
366 
367                 /*
368                  * Shift lnum[0] - 1 items in whole.
369                  * Shift lbytes - 1 entries from given directory item
370                  */
371                 ret = leaf_shift_left(tb, tb->lnum[0], tb->lbytes - 1);
372                 if (ret && !tb->item_pos) {
373                         pasted = item_head(tb->L[0], B_NR_ITEMS(tb->L[0]) - 1);
374                         l_pos_in_item += ih_entry_count(pasted) -
375                                          (tb->lbytes - 1);
376                 }
377 
378                 /* Append given directory entry to directory item */
379                 buffer_info_init_left(tb, &bi);
380                 leaf_paste_in_buffer(&bi, n + tb->item_pos - ret,
381                                      l_pos_in_item, tb->insert_size[0],
382                                      body, tb->zeroes_num);
383 
384                 /*
385                  * previous string prepared space for pasting new entry,
386                  * following string pastes this entry
387                  */
388 
389                 /*
390                  * when we have merge directory item, pos_in_item
391                  * has been changed too
392                  */
393 
394                 /* paste new directory entry. 1 is entry number */
395                 leaf_paste_entries(&bi, n + tb->item_pos - ret,
396                                    l_pos_in_item, 1,
397                                    (struct reiserfs_de_head *) body,
398                                    body + DEH_SIZE, tb->insert_size[0]);
399                 tb->insert_size[0] = 0;
400         } else {
401                 /* new directory item doesn't fall into L[0] */
402                 /*
403                  * Shift lnum[0]-1 items in whole. Shift lbytes
404                  * directory entries from directory item number lnum[0]
405                  */
406                 leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
407         }
408 
409         /* Calculate new position to append in item body */
410         tb->pos_in_item -= tb->lbytes;
411 }
412 
413 static unsigned int balance_leaf_paste_left_shift(struct tree_balance *tb,
414                                                   struct item_head * const ih,
415                                                   const char * const body)
416 {
417         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
418         int n = B_NR_ITEMS(tb->L[0]);
419         struct buffer_info bi;
420         int body_shift_bytes = 0;
421 
422         if (is_direntry_le_ih(item_head(tbS0, tb->item_pos))) {
423                 balance_leaf_paste_left_shift_dirent(tb, ih, body);
424                 return 0;
425         }
426 
427         RFALSE(tb->lbytes <= 0,
428                "PAP-12095: there is nothing to shift to L[0]. "
429                "lbytes=%d", tb->lbytes);
430         RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)),
431                "PAP-12100: incorrect position to paste: "
432                "item_len=%d, pos_in_item=%d",
433                ih_item_len(item_head(tbS0, tb->item_pos)), tb->pos_in_item);
434 
435         /* appended item will be in L[0] in whole */
436         if (tb->lbytes >= tb->pos_in_item) {
437                 struct item_head *tbS0_pos_ih, *tbL0_ih;
438                 struct item_head *tbS0_0_ih;
439                 struct reiserfs_key *left_delim_key;
440                 int ret, l_n, version, temp_l;
441 
442                 tbS0_pos_ih = item_head(tbS0, tb->item_pos);
443                 tbS0_0_ih = item_head(tbS0, 0);
444 
445                 /*
446                  * this bytes number must be appended
447                  * to the last item of L[h]
448                  */
449                 l_n = tb->lbytes - tb->pos_in_item;
450 
451                 /* Calculate new insert_size[0] */
452                 tb->insert_size[0] -= l_n;
453 
454                 RFALSE(tb->insert_size[0] <= 0,
455                        "PAP-12105: there is nothing to paste into "
456                        "L[0]. insert_size=%d", tb->insert_size[0]);
457 
458                 ret = leaf_shift_left(tb, tb->lnum[0],
459                                       ih_item_len(tbS0_pos_ih));
460 
461                 tbL0_ih = item_head(tb->L[0], n + tb->item_pos - ret);
462 
463                 /* Append to body of item in L[0] */
464                 buffer_info_init_left(tb, &bi);
465                 leaf_paste_in_buffer(&bi, n + tb->item_pos - ret,
466                                      ih_item_len(tbL0_ih), l_n, body,
467                                      min_t(int, l_n, tb->zeroes_num));
468 
469                 /*
470                  * 0-th item in S0 can be only of DIRECT type
471                  * when l_n != 0
472                  */
473                 temp_l = l_n;
474 
475                 RFALSE(ih_item_len(tbS0_0_ih),
476                        "PAP-12106: item length must be 0");
477                 RFALSE(comp_short_le_keys(&tbS0_0_ih->ih_key,
478                        leaf_key(tb->L[0], n + tb->item_pos - ret)),
479                        "PAP-12107: items must be of the same file");
480 
481                 if (is_indirect_le_ih(tbL0_ih)) {
482                         int shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
483                         temp_l = l_n << shift;
484                 }
485                 /* update key of first item in S0 */
486                 version = ih_version(tbS0_0_ih);
487                 add_le_key_k_offset(version, &tbS0_0_ih->ih_key, temp_l);
488 
489                 /* update left delimiting key */
490                 left_delim_key = internal_key(tb->CFL[0], tb->lkey[0]);
491                 add_le_key_k_offset(version, left_delim_key, temp_l);
492 
493                 /*
494                  * Calculate new body, position in item and
495                  * insert_size[0]
496                  */
497                 if (l_n > tb->zeroes_num) {
498                         body_shift_bytes = l_n - tb->zeroes_num;
499                         tb->zeroes_num = 0;
500                 } else
501                         tb->zeroes_num -= l_n;
502                 tb->pos_in_item = 0;
503 
504                 RFALSE(comp_short_le_keys(&tbS0_0_ih->ih_key,
505                                           leaf_key(tb->L[0],
506                                                  B_NR_ITEMS(tb->L[0]) - 1)) ||
507                        !op_is_left_mergeable(leaf_key(tbS0, 0), tbS0->b_size) ||
508                        !op_is_left_mergeable(left_delim_key, tbS0->b_size),
509                        "PAP-12120: item must be merge-able with left "
510                        "neighboring item");
511         } else {
512                 /* only part of the appended item will be in L[0] */
513 
514                 /* Calculate position in item for append in S[0] */
515                 tb->pos_in_item -= tb->lbytes;
516 
517                 RFALSE(tb->pos_in_item <= 0,
518                        "PAP-12125: no place for paste. pos_in_item=%d",
519                        tb->pos_in_item);
520 
521                 /*
522                  * Shift lnum[0] - 1 items in whole.
523                  * Shift lbytes - 1 byte from item number lnum[0]
524                  */
525                 leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
526         }
527         return body_shift_bytes;
528 }
529 
530 
531 /* appended item will be in L[0] in whole */
532 static void balance_leaf_paste_left_whole(struct tree_balance *tb,
533                                           struct item_head * const ih,
534                                           const char * const body)
535 {
536         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
537         int n = B_NR_ITEMS(tb->L[0]);
538         struct buffer_info bi;
539         struct item_head *pasted;
540         int ret;
541 
542         /* if we paste into first item of S[0] and it is left mergable */
543         if (!tb->item_pos &&
544             op_is_left_mergeable(leaf_key(tbS0, 0), tbS0->b_size)) {
545                 /*
546                  * then increment pos_in_item by the size of the
547                  * last item in L[0]
548                  */
549                 pasted = item_head(tb->L[0], n - 1);
550                 if (is_direntry_le_ih(pasted))
551                         tb->pos_in_item += ih_entry_count(pasted);
552                 else
553                         tb->pos_in_item += ih_item_len(pasted);
554         }
555 
556         /*
557          * Shift lnum[0] - 1 items in whole.
558          * Shift lbytes - 1 byte from item number lnum[0]
559          */
560         ret = leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
561 
562         /* Append to body of item in L[0] */
563         buffer_info_init_left(tb, &bi);
564         leaf_paste_in_buffer(&bi, n + tb->item_pos - ret, tb->pos_in_item,
565                              tb->insert_size[0], body, tb->zeroes_num);
566 
567         /* if appended item is directory, paste entry */
568         pasted = item_head(tb->L[0], n + tb->item_pos - ret);
569         if (is_direntry_le_ih(pasted))
570                 leaf_paste_entries(&bi, n + tb->item_pos - ret,
571                                    tb->pos_in_item, 1,
572                                    (struct reiserfs_de_head *)body,
573                                    body + DEH_SIZE, tb->insert_size[0]);
574 
575         /*
576          * if appended item is indirect item, put unformatted node
577          * into un list
578          */
579         if (is_indirect_le_ih(pasted))
580                 set_ih_free_space(pasted, 0);
581 
582         tb->insert_size[0] = 0;
583         tb->zeroes_num = 0;
584 }
585 
586 static unsigned int balance_leaf_paste_left(struct tree_balance *tb,
587                                             struct item_head * const ih,
588                                             const char * const body)
589 {
590         /* we must shift the part of the appended item */
591         if (tb->item_pos == tb->lnum[0] - 1 && tb->lbytes != -1)
592                 return balance_leaf_paste_left_shift(tb, ih, body);
593         else
594                 balance_leaf_paste_left_whole(tb, ih, body);
595         return 0;
596 }
597 
598 /* Shift lnum[0] items from S[0] to the left neighbor L[0] */
599 static unsigned int balance_leaf_left(struct tree_balance *tb,
600                                       struct item_head * const ih,
601                                       const char * const body, int flag)
602 {
603         if (tb->lnum[0] <= 0)
604                 return 0;
605 
606         /* new item or it part falls to L[0], shift it too */
607         if (tb->item_pos < tb->lnum[0]) {
608                 BUG_ON(flag != M_INSERT && flag != M_PASTE);
609 
610                 if (flag == M_INSERT)
611                         return balance_leaf_insert_left(tb, ih, body);
612                 else /* M_PASTE */
613                         return balance_leaf_paste_left(tb, ih, body);
614         } else
615                 /* new item doesn't fall into L[0] */
616                 leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
617         return 0;
618 }
619 
620 
621 static void balance_leaf_insert_right(struct tree_balance *tb,
622                                       struct item_head * const ih,
623                                       const char * const body)
624 {
625 
626         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
627         int n = B_NR_ITEMS(tbS0);
628         struct buffer_info bi;
629 
630         /* new item or part of it doesn't fall into R[0] */
631         if (n - tb->rnum[0] >= tb->item_pos) {
632                 leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
633                 return;
634         }
635 
636         /* new item or its part falls to R[0] */
637 
638         /* part of new item falls into R[0] */
639         if (tb->item_pos == n - tb->rnum[0] + 1 && tb->rbytes != -1) {
640                 loff_t old_key_comp, old_len, r_zeroes_number;
641                 const char *r_body;
642                 int shift;
643                 loff_t offset;
644 
645                 leaf_shift_right(tb, tb->rnum[0] - 1, -1);
646 
647                 /* Remember key component and item length */
648                 old_key_comp = le_ih_k_offset(ih);
649                 old_len = ih_item_len(ih);
650 
651                 /*
652                  * Calculate key component and item length to insert
653                  * into R[0]
654                  */
655                 shift = 0;
656                 if (is_indirect_le_ih(ih))
657                         shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
658                 offset = le_ih_k_offset(ih) + ((old_len - tb->rbytes) << shift);
659                 set_le_ih_k_offset(ih, offset);
660                 put_ih_item_len(ih, tb->rbytes);
661 
662                 /* Insert part of the item into R[0] */
663                 buffer_info_init_right(tb, &bi);
664                 if ((old_len - tb->rbytes) > tb->zeroes_num) {
665                         r_zeroes_number = 0;
666                         r_body = body + (old_len - tb->rbytes) - tb->zeroes_num;
667                 } else {
668                         r_body = body;
669                         r_zeroes_number = tb->zeroes_num -
670                                           (old_len - tb->rbytes);
671                         tb->zeroes_num -= r_zeroes_number;
672                 }
673 
674                 leaf_insert_into_buf(&bi, 0, ih, r_body, r_zeroes_number);
675 
676                 /* Replace right delimiting key by first key in R[0] */
677                 replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
678 
679                 /*
680                  * Calculate key component and item length to
681                  * insert into S[0]
682                  */
683                 set_le_ih_k_offset(ih, old_key_comp);
684                 put_ih_item_len(ih, old_len - tb->rbytes);
685 
686                 tb->insert_size[0] -= tb->rbytes;
687 
688         } else {
689                 /* whole new item falls into R[0] */
690 
691                 /* Shift rnum[0]-1 items to R[0] */
692                 leaf_shift_right(tb, tb->rnum[0] - 1, tb->rbytes);
693 
694                 /* Insert new item into R[0] */
695                 buffer_info_init_right(tb, &bi);
696                 leaf_insert_into_buf(&bi, tb->item_pos - n + tb->rnum[0] - 1,
697                                      ih, body, tb->zeroes_num);
698 
699                 if (tb->item_pos - n + tb->rnum[0] - 1 == 0)
700                         replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
701 
702                 tb->zeroes_num = tb->insert_size[0] = 0;
703         }
704 }
705 
706 
707 static void balance_leaf_paste_right_shift_dirent(struct tree_balance *tb,
708                                      struct item_head * const ih,
709                                      const char * const body)
710 {
711         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
712         struct buffer_info bi;
713         int entry_count;
714 
715         RFALSE(tb->zeroes_num,
716                "PAP-12145: invalid parameter in case of a directory");
717         entry_count = ih_entry_count(item_head(tbS0, tb->item_pos));
718 
719         /* new directory entry falls into R[0] */
720         if (entry_count - tb->rbytes < tb->pos_in_item) {
721                 int paste_entry_position;
722 
723                 RFALSE(tb->rbytes - 1 >= entry_count || !tb->insert_size[0],
724                        "PAP-12150: no enough of entries to shift to R[0]: "
725                        "rbytes=%d, entry_count=%d", tb->rbytes, entry_count);
726 
727                 /*
728                  * Shift rnum[0]-1 items in whole.
729                  * Shift rbytes-1 directory entries from directory
730                  * item number rnum[0]
731                  */
732                 leaf_shift_right(tb, tb->rnum[0], tb->rbytes - 1);
733 
734                 /* Paste given directory entry to directory item */
735                 paste_entry_position = tb->pos_in_item - entry_count +
736                                        tb->rbytes - 1;
737                 buffer_info_init_right(tb, &bi);
738                 leaf_paste_in_buffer(&bi, 0, paste_entry_position,
739                                      tb->insert_size[0], body, tb->zeroes_num);
740 
741                 /* paste entry */
742                 leaf_paste_entries(&bi, 0, paste_entry_position, 1,
743                                    (struct reiserfs_de_head *) body,
744                                    body + DEH_SIZE, tb->insert_size[0]);
745 
746                 /* change delimiting keys */
747                 if (paste_entry_position == 0)
748                         replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
749 
750                 tb->insert_size[0] = 0;
751                 tb->pos_in_item++;
752         } else {
753                 /* new directory entry doesn't fall into R[0] */
754                 leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
755         }
756 }
757 
758 static void balance_leaf_paste_right_shift(struct tree_balance *tb,
759                                      struct item_head * const ih,
760                                      const char * const body)
761 {
762         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
763         int n_shift, n_rem, r_zeroes_number, version;
764         unsigned long temp_rem;
765         const char *r_body;
766         struct buffer_info bi;
767 
768         /* we append to directory item */
769         if (is_direntry_le_ih(item_head(tbS0, tb->item_pos))) {
770                 balance_leaf_paste_right_shift_dirent(tb, ih, body);
771                 return;
772         }
773 
774         /* regular object */
775 
776         /*
777          * Calculate number of bytes which must be shifted
778          * from appended item
779          */
780         n_shift = tb->rbytes - tb->insert_size[0];
781         if (n_shift < 0)
782                 n_shift = 0;
783 
784         RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)),
785                "PAP-12155: invalid position to paste. ih_item_len=%d, "
786                "pos_in_item=%d", tb->pos_in_item,
787                ih_item_len(item_head(tbS0, tb->item_pos)));
788 
789         leaf_shift_right(tb, tb->rnum[0], n_shift);
790 
791         /*
792          * Calculate number of bytes which must remain in body
793          * after appending to R[0]
794          */
795         n_rem = tb->insert_size[0] - tb->rbytes;
796         if (n_rem < 0)
797                 n_rem = 0;
798 
799         temp_rem = n_rem;
800 
801         version = ih_version(item_head(tb->R[0], 0));
802 
803         if (is_indirect_le_key(version, leaf_key(tb->R[0], 0))) {
804                 int shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
805                 temp_rem = n_rem << shift;
806         }
807 
808         add_le_key_k_offset(version, leaf_key(tb->R[0], 0), temp_rem);
809         add_le_key_k_offset(version, internal_key(tb->CFR[0], tb->rkey[0]),
810                             temp_rem);
811 
812         do_balance_mark_internal_dirty(tb, tb->CFR[0], 0);
813 
814         /* Append part of body into R[0] */
815         buffer_info_init_right(tb, &bi);
816         if (n_rem > tb->zeroes_num) {
817                 r_zeroes_number = 0;
818                 r_body = body + n_rem - tb->zeroes_num;
819         } else {
820                 r_body = body;
821                 r_zeroes_number = tb->zeroes_num - n_rem;
822                 tb->zeroes_num -= r_zeroes_number;
823         }
824 
825         leaf_paste_in_buffer(&bi, 0, n_shift, tb->insert_size[0] - n_rem,
826                              r_body, r_zeroes_number);
827 
828         if (is_indirect_le_ih(item_head(tb->R[0], 0)))
829                 set_ih_free_space(item_head(tb->R[0], 0), 0);
830 
831         tb->insert_size[0] = n_rem;
832         if (!n_rem)
833                 tb->pos_in_item++;
834 }
835 
836 static void balance_leaf_paste_right_whole(struct tree_balance *tb,
837                                      struct item_head * const ih,
838                                      const char * const body)
839 {
840         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
841         int n = B_NR_ITEMS(tbS0);
842         struct item_head *pasted;
843         struct buffer_info bi;
844 
845                                                         buffer_info_init_right(tb, &bi);
846         leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
847 
848         /* append item in R[0] */
849         if (tb->pos_in_item >= 0) {
850                 buffer_info_init_right(tb, &bi);
851                 leaf_paste_in_buffer(&bi, tb->item_pos - n + tb->rnum[0],
852                                      tb->pos_in_item, tb->insert_size[0], body,
853                                      tb->zeroes_num);
854         }
855 
856         /* paste new entry, if item is directory item */
857         pasted = item_head(tb->R[0], tb->item_pos - n + tb->rnum[0]);
858         if (is_direntry_le_ih(pasted) && tb->pos_in_item >= 0) {
859                 leaf_paste_entries(&bi, tb->item_pos - n + tb->rnum[0],
860                                    tb->pos_in_item, 1,
861                                    (struct reiserfs_de_head *)body,
862                                    body + DEH_SIZE, tb->insert_size[0]);
863 
864                 if (!tb->pos_in_item) {
865 
866                         RFALSE(tb->item_pos - n + tb->rnum[0],
867                                "PAP-12165: directory item must be first "
868                                "item of node when pasting is in 0th position");
869 
870                         /* update delimiting keys */
871                         replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
872                 }
873         }
874 
875         if (is_indirect_le_ih(pasted))
876                 set_ih_free_space(pasted, 0);
877         tb->zeroes_num = tb->insert_size[0] = 0;
878 }
879 
880 static void balance_leaf_paste_right(struct tree_balance *tb,
881                                      struct item_head * const ih,
882                                      const char * const body)
883 {
884         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
885         int n = B_NR_ITEMS(tbS0);
886 
887         /* new item doesn't fall into R[0] */
888         if (n - tb->rnum[0] > tb->item_pos) {
889                 leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
890                 return;
891         }
892 
893         /* pasted item or part of it falls to R[0] */
894 
895         if (tb->item_pos == n - tb->rnum[0] && tb->rbytes != -1)
896                 /* we must shift the part of the appended item */
897                 balance_leaf_paste_right_shift(tb, ih, body);
898         else
899                 /* pasted item in whole falls into R[0] */
900                 balance_leaf_paste_right_whole(tb, ih, body);
901 }
902 
903 /* shift rnum[0] items from S[0] to the right neighbor R[0] */
904 static void balance_leaf_right(struct tree_balance *tb,
905                                struct item_head * const ih,
906                                const char * const body, int flag)
907 {
908         if (tb->rnum[0] <= 0)
909                 return;
910 
911         BUG_ON(flag != M_INSERT && flag != M_PASTE);
912 
913         if (flag == M_INSERT)
914                 balance_leaf_insert_right(tb, ih, body);
915         else /* M_PASTE */
916                 balance_leaf_paste_right(tb, ih, body);
917 }
918 
919 static void balance_leaf_new_nodes_insert(struct tree_balance *tb,
920                                           struct item_head * const ih,
921                                           const char * const body,
922                                           struct item_head *insert_key,
923                                           struct buffer_head **insert_ptr,
924                                           int i)
925 {
926         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
927         int n = B_NR_ITEMS(tbS0);
928         struct buffer_info bi;
929         int shift;
930 
931         /* new item or it part don't falls into S_new[i] */
932         if (n - tb->snum[i] >= tb->item_pos) {
933                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
934                                 tb->snum[i], tb->sbytes[i], tb->S_new[i]);
935                 return;
936         }
937 
938         /* new item or it's part falls to first new node S_new[i] */
939 
940         /* part of new item falls into S_new[i] */
941         if (tb->item_pos == n - tb->snum[i] + 1 && tb->sbytes[i] != -1) {
942                 int old_key_comp, old_len, r_zeroes_number;
943                 const char *r_body;
944 
945                 /* Move snum[i]-1 items from S[0] to S_new[i] */
946                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i] - 1, -1,
947                                 tb->S_new[i]);
948 
949                 /* Remember key component and item length */
950                 old_key_comp = le_ih_k_offset(ih);
951                 old_len = ih_item_len(ih);
952 
953                 /*
954                  * Calculate key component and item length to insert
955                  * into S_new[i]
956                  */
957                 shift = 0;
958                 if (is_indirect_le_ih(ih))
959                         shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
960                 set_le_ih_k_offset(ih,
961                                    le_ih_k_offset(ih) +
962                                    ((old_len - tb->sbytes[i]) << shift));
963 
964                 put_ih_item_len(ih, tb->sbytes[i]);
965 
966                 /* Insert part of the item into S_new[i] before 0-th item */
967                 buffer_info_init_bh(tb, &bi, tb->S_new[i]);
968 
969                 if ((old_len - tb->sbytes[i]) > tb->zeroes_num) {
970                         r_zeroes_number = 0;
971                         r_body = body + (old_len - tb->sbytes[i]) -
972                                          tb->zeroes_num;
973                 } else {
974                         r_body = body;
975                         r_zeroes_number = tb->zeroes_num - (old_len -
976                                           tb->sbytes[i]);
977                         tb->zeroes_num -= r_zeroes_number;
978                 }
979 
980                 leaf_insert_into_buf(&bi, 0, ih, r_body, r_zeroes_number);
981 
982                 /*
983                  * Calculate key component and item length to
984                  * insert into S[i]
985                  */
986                 set_le_ih_k_offset(ih, old_key_comp);
987                 put_ih_item_len(ih, old_len - tb->sbytes[i]);
988                 tb->insert_size[0] -= tb->sbytes[i];
989         } else {
990                 /* whole new item falls into S_new[i] */
991 
992                 /*
993                  * Shift snum[0] - 1 items to S_new[i]
994                  * (sbytes[i] of split item)
995                  */
996                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
997                                 tb->snum[i] - 1, tb->sbytes[i], tb->S_new[i]);
998 
999                 /* Insert new item into S_new[i] */
1000                 buffer_info_init_bh(tb, &bi, tb->S_new[i]);
1001                 leaf_insert_into_buf(&bi, tb->item_pos - n + tb->snum[i] - 1,
1002                                      ih, body, tb->zeroes_num);
1003 
1004                 tb->zeroes_num = tb->insert_size[0] = 0;
1005         }
1006 }
1007 
1008 /* we append to directory item */
1009 static void balance_leaf_new_nodes_paste_dirent(struct tree_balance *tb,
1010                                          struct item_head * const ih,
1011                                          const char * const body,
1012                                          struct item_head *insert_key,
1013                                          struct buffer_head **insert_ptr,
1014                                          int i)
1015 {
1016         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1017         struct item_head *aux_ih = item_head(tbS0, tb->item_pos);
1018         int entry_count = ih_entry_count(aux_ih);
1019         struct buffer_info bi;
1020 
1021         if (entry_count - tb->sbytes[i] < tb->pos_in_item &&
1022             tb->pos_in_item <= entry_count) {
1023                 /* new directory entry falls into S_new[i] */
1024 
1025                 RFALSE(!tb->insert_size[0],
1026                        "PAP-12215: insert_size is already 0");
1027                 RFALSE(tb->sbytes[i] - 1 >= entry_count,
1028                        "PAP-12220: there are no so much entries (%d), only %d",
1029                        tb->sbytes[i] - 1, entry_count);
1030 
1031                 /*
1032                  * Shift snum[i]-1 items in whole.
1033                  * Shift sbytes[i] directory entries
1034                  * from directory item number snum[i]
1035                  */
1036                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i],
1037                                 tb->sbytes[i] - 1, tb->S_new[i]);
1038 
1039                 /*
1040                  * Paste given directory entry to
1041                  * directory item
1042                  */
1043                 buffer_info_init_bh(tb, &bi, tb->S_new[i]);
1044                 leaf_paste_in_buffer(&bi, 0, tb->pos_in_item - entry_count +
1045                                      tb->sbytes[i] - 1, tb->insert_size[0],
1046                                      body, tb->zeroes_num);
1047 
1048                 /* paste new directory entry */
1049                 leaf_paste_entries(&bi, 0, tb->pos_in_item - entry_count +
1050                                    tb->sbytes[i] - 1, 1,
1051                                    (struct reiserfs_de_head *) body,
1052                                    body + DEH_SIZE, tb->insert_size[0]);
1053 
1054                 tb->insert_size[0] = 0;
1055                 tb->pos_in_item++;
1056         } else {
1057                 /* new directory entry doesn't fall into S_new[i] */
1058                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i],
1059                                 tb->sbytes[i], tb->S_new[i]);
1060         }
1061 
1062 }
1063 
1064 static void balance_leaf_new_nodes_paste_shift(struct tree_balance *tb,
1065                                          struct item_head * const ih,
1066                                          const char * const body,
1067                                          struct item_head *insert_key,
1068                                          struct buffer_head **insert_ptr,
1069                                          int i)
1070 {
1071         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1072         struct item_head *aux_ih = item_head(tbS0, tb->item_pos);
1073         int n_shift, n_rem, r_zeroes_number, shift;
1074         const char *r_body;
1075         struct item_head *tmp;
1076         struct buffer_info bi;
1077 
1078         RFALSE(ih, "PAP-12210: ih must be 0");
1079 
1080         if (is_direntry_le_ih(aux_ih)) {
1081                 balance_leaf_new_nodes_paste_dirent(tb, ih, body, insert_key,
1082                                                     insert_ptr, i);
1083                 return;
1084         }
1085 
1086         /* regular object */
1087 
1088 
1089         RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)) ||
1090                tb->insert_size[0] <= 0,
1091                "PAP-12225: item too short or insert_size <= 0");
1092 
1093         /*
1094          * Calculate number of bytes which must be shifted from appended item
1095          */
1096         n_shift = tb->sbytes[i] - tb->insert_size[0];
1097         if (n_shift < 0)
1098                 n_shift = 0;
1099         leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i], n_shift,
1100                         tb->S_new[i]);
1101 
1102         /*
1103          * Calculate number of bytes which must remain in body after
1104          * append to S_new[i]
1105          */
1106         n_rem = tb->insert_size[0] - tb->sbytes[i];
1107         if (n_rem < 0)
1108                 n_rem = 0;
1109 
1110         /* Append part of body into S_new[0] */
1111         buffer_info_init_bh(tb, &bi, tb->S_new[i]);
1112         if (n_rem > tb->zeroes_num) {
1113                 r_zeroes_number = 0;
1114                 r_body = body + n_rem - tb->zeroes_num;
1115         } else {
1116                 r_body = body;
1117                 r_zeroes_number = tb->zeroes_num - n_rem;
1118                 tb->zeroes_num -= r_zeroes_number;
1119         }
1120 
1121         leaf_paste_in_buffer(&bi, 0, n_shift, tb->insert_size[0] - n_rem,
1122                              r_body, r_zeroes_number);
1123 
1124         tmp = item_head(tb->S_new[i], 0);
1125         shift = 0;
1126         if (is_indirect_le_ih(tmp)) {
1127                 set_ih_free_space(tmp, 0);
1128                 shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
1129         }
1130         add_le_ih_k_offset(tmp, n_rem << shift);
1131 
1132         tb->insert_size[0] = n_rem;
1133         if (!n_rem)
1134                 tb->pos_in_item++;
1135 }
1136 
1137 static void balance_leaf_new_nodes_paste_whole(struct tree_balance *tb,
1138                                                struct item_head * const ih,
1139                                                const char * const body,
1140                                                struct item_head *insert_key,
1141                                                struct buffer_head **insert_ptr,
1142                                                int i)
1143 
1144 {
1145         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1146         int n = B_NR_ITEMS(tbS0);
1147         int leaf_mi;
1148         struct item_head *pasted;
1149         struct buffer_info bi;
1150 
1151 #ifdef CONFIG_REISERFS_CHECK
1152         struct item_head *ih_check = item_head(tbS0, tb->item_pos);
1153 
1154         if (!is_direntry_le_ih(ih_check) &&
1155             (tb->pos_in_item != ih_item_len(ih_check) ||
1156             tb->insert_size[0] <= 0))
1157                 reiserfs_panic(tb->tb_sb,
1158                              "PAP-12235",
1159                              "pos_in_item must be equal to ih_item_len");
1160 #endif
1161 
1162         leaf_mi = leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i],
1163                                   tb->sbytes[i], tb->S_new[i]);
1164 
1165         RFALSE(leaf_mi,
1166                "PAP-12240: unexpected value returned by leaf_move_items (%d)",
1167                leaf_mi);
1168 
1169         /* paste into item */
1170         buffer_info_init_bh(tb, &bi, tb->S_new[i]);
1171         leaf_paste_in_buffer(&bi, tb->item_pos - n + tb->snum[i],
1172                              tb->pos_in_item, tb->insert_size[0],
1173                              body, tb->zeroes_num);
1174 
1175         pasted = item_head(tb->S_new[i], tb->item_pos - n +
1176                            tb->snum[i]);
1177         if (is_direntry_le_ih(pasted))
1178                 leaf_paste_entries(&bi, tb->item_pos - n + tb->snum[i],
1179                                    tb->pos_in_item, 1,
1180                                    (struct reiserfs_de_head *)body,
1181                                    body + DEH_SIZE, tb->insert_size[0]);
1182 
1183         /* if we paste to indirect item update ih_free_space */
1184         if (is_indirect_le_ih(pasted))
1185                 set_ih_free_space(pasted, 0);
1186 
1187         tb->zeroes_num = tb->insert_size[0] = 0;
1188 
1189 }
1190 static void balance_leaf_new_nodes_paste(struct tree_balance *tb,
1191                                          struct item_head * const ih,
1192                                          const char * const body,
1193                                          struct item_head *insert_key,
1194                                          struct buffer_head **insert_ptr,
1195                                          int i)
1196 {
1197         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1198         int n = B_NR_ITEMS(tbS0);
1199 
1200         /* pasted item doesn't fall into S_new[i] */
1201         if (n - tb->snum[i] > tb->item_pos) {
1202                 leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
1203                                 tb->snum[i], tb->sbytes[i], tb->S_new[i]);
1204                 return;
1205         }
1206 
1207         /* pasted item or part if it falls to S_new[i] */
1208 
1209         if (tb->item_pos == n - tb->snum[i] && tb->sbytes[i] != -1)
1210                 /* we must shift part of the appended item */
1211                 balance_leaf_new_nodes_paste_shift(tb, ih, body, insert_key,
1212                                                    insert_ptr, i);
1213         else
1214                 /* item falls wholly into S_new[i] */
1215                 balance_leaf_new_nodes_paste_whole(tb, ih, body, insert_key,
1216                                                    insert_ptr, i);
1217 }
1218 
1219 /* Fill new nodes that appear in place of S[0] */
1220 static void balance_leaf_new_nodes(struct tree_balance *tb,
1221                                    struct item_head * const ih,
1222                                    const char * const body,
1223                                    struct item_head *insert_key,
1224                                    struct buffer_head **insert_ptr,
1225                                    int flag)
1226 {
1227         int i;
1228         for (i = tb->blknum[0] - 2; i >= 0; i--) {
1229                 BUG_ON(flag != M_INSERT && flag != M_PASTE);
1230 
1231                 RFALSE(!tb->snum[i],
1232                        "PAP-12200: snum[%d] == %d. Must be > 0", i,
1233                        tb->snum[i]);
1234 
1235                 /* here we shift from S to S_new nodes */
1236 
1237                 tb->S_new[i] = get_FEB(tb);
1238 
1239                 /* initialized block type and tree level */
1240                 set_blkh_level(B_BLK_HEAD(tb->S_new[i]), DISK_LEAF_NODE_LEVEL);
1241 
1242                 if (flag == M_INSERT)
1243                         balance_leaf_new_nodes_insert(tb, ih, body, insert_key,
1244                                                       insert_ptr, i);
1245                 else /* M_PASTE */
1246                         balance_leaf_new_nodes_paste(tb, ih, body, insert_key,
1247                                                      insert_ptr, i);
1248 
1249                 memcpy(insert_key + i, leaf_key(tb->S_new[i], 0), KEY_SIZE);
1250                 insert_ptr[i] = tb->S_new[i];
1251 
1252                 RFALSE(!buffer_journaled(tb->S_new[i])
1253                        || buffer_journal_dirty(tb->S_new[i])
1254                        || buffer_dirty(tb->S_new[i]),
1255                        "PAP-12247: S_new[%d] : (%b)",
1256                        i, tb->S_new[i]);
1257         }
1258 }
1259 
1260 static void balance_leaf_finish_node_insert(struct tree_balance *tb,
1261                                             struct item_head * const ih,
1262                                             const char * const body)
1263 {
1264         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1265         struct buffer_info bi;
1266         buffer_info_init_tbS0(tb, &bi);
1267         leaf_insert_into_buf(&bi, tb->item_pos, ih, body, tb->zeroes_num);
1268 
1269         /* If we insert the first key change the delimiting key */
1270         if (tb->item_pos == 0) {
1271                 if (tb->CFL[0]) /* can be 0 in reiserfsck */
1272                         replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
1273 
1274         }
1275 }
1276 
1277 static void balance_leaf_finish_node_paste_dirent(struct tree_balance *tb,
1278                                                   struct item_head * const ih,
1279                                                   const char * const body)
1280 {
1281         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1282         struct item_head *pasted = item_head(tbS0, tb->item_pos);
1283         struct buffer_info bi;
1284 
1285         if (tb->pos_in_item >= 0 && tb->pos_in_item <= ih_entry_count(pasted)) {
1286                 RFALSE(!tb->insert_size[0],
1287                        "PAP-12260: insert_size is 0 already");
1288 
1289                 /* prepare space */
1290                 buffer_info_init_tbS0(tb, &bi);
1291                 leaf_paste_in_buffer(&bi, tb->item_pos, tb->pos_in_item,
1292                                      tb->insert_size[0], body, tb->zeroes_num);
1293 
1294                 /* paste entry */
1295                 leaf_paste_entries(&bi, tb->item_pos, tb->pos_in_item, 1,
1296                                    (struct reiserfs_de_head *)body,
1297                                    body + DEH_SIZE, tb->insert_size[0]);
1298 
1299                 if (!tb->item_pos && !tb->pos_in_item) {
1300                         RFALSE(!tb->CFL[0] || !tb->L[0],
1301                                "PAP-12270: CFL[0]/L[0] must  be specified");
1302                         if (tb->CFL[0])
1303                                 replace_key(tb, tb->CFL[0], tb->lkey[0],
1304                                             tbS0, 0);
1305                 }
1306 
1307                 tb->insert_size[0] = 0;
1308         }
1309 }
1310 
1311 static void balance_leaf_finish_node_paste(struct tree_balance *tb,
1312                                            struct item_head * const ih,
1313                                            const char * const body)
1314 {
1315         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1316         struct buffer_info bi;
1317         struct item_head *pasted = item_head(tbS0, tb->item_pos);
1318 
1319         /* when directory, may be new entry already pasted */
1320         if (is_direntry_le_ih(pasted)) {
1321                 balance_leaf_finish_node_paste_dirent(tb, ih, body);
1322                 return;
1323         }
1324 
1325         /* regular object */
1326 
1327         if (tb->pos_in_item == ih_item_len(pasted)) {
1328                 RFALSE(tb->insert_size[0] <= 0,
1329                        "PAP-12275: insert size must not be %d",
1330                        tb->insert_size[0]);
1331                 buffer_info_init_tbS0(tb, &bi);
1332                 leaf_paste_in_buffer(&bi, tb->item_pos,
1333                                      tb->pos_in_item, tb->insert_size[0], body,
1334                                      tb->zeroes_num);
1335 
1336                 if (is_indirect_le_ih(pasted))
1337                         set_ih_free_space(pasted, 0);
1338 
1339                 tb->insert_size[0] = 0;
1340         }
1341 #ifdef CONFIG_REISERFS_CHECK
1342         else if (tb->insert_size[0]) {
1343                 print_cur_tb("12285");
1344                 reiserfs_panic(tb->tb_sb, "PAP-12285",
1345                     "insert_size must be 0 (%d)", tb->insert_size[0]);
1346         }
1347 #endif
1348 }
1349 
1350 /*
1351  * if the affected item was not wholly shifted then we
1352  * perform all necessary operations on that part or whole
1353  * of the affected item which remains in S
1354  */
1355 static void balance_leaf_finish_node(struct tree_balance *tb,
1356                                       struct item_head * const ih,
1357                                       const char * const body, int flag)
1358 {
1359         /* if we must insert or append into buffer S[0] */
1360         if (0 <= tb->item_pos && tb->item_pos < tb->s0num) {
1361                 if (flag == M_INSERT)
1362                         balance_leaf_finish_node_insert(tb, ih, body);
1363                 else /* M_PASTE */
1364                         balance_leaf_finish_node_paste(tb, ih, body);
1365         }
1366 }
1367 
1368 /**
1369  * balance_leaf - reiserfs tree balancing algorithm
1370  * @tb: tree balance state
1371  * @ih: item header of inserted item (little endian)
1372  * @body: body of inserted item or bytes to paste
1373  * @flag: i - insert, d - delete, c - cut, p - paste (see do_balance)
1374  * passed back:
1375  * @insert_key: key to insert new nodes
1376  * @insert_ptr: array of nodes to insert at the next level
1377  *
1378  * In our processing of one level we sometimes determine what must be
1379  * inserted into the next higher level.  This insertion consists of a
1380  * key or two keys and their corresponding pointers.
1381  */
1382 static int balance_leaf(struct tree_balance *tb, struct item_head *ih,
1383                         const char *body, int flag,
1384                         struct item_head *insert_key,
1385                         struct buffer_head **insert_ptr)
1386 {
1387         struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
1388 
1389         PROC_INFO_INC(tb->tb_sb, balance_at[0]);
1390 
1391         /* Make balance in case insert_size[0] < 0 */
1392         if (tb->insert_size[0] < 0)
1393                 return balance_leaf_when_delete(tb, flag);
1394 
1395         tb->item_pos = PATH_LAST_POSITION(tb->tb_path),
1396         tb->pos_in_item = tb->tb_path->pos_in_item,
1397         tb->zeroes_num = 0;
1398         if (flag == M_INSERT && !body)
1399                 tb->zeroes_num = ih_item_len(ih);
1400 
1401         /*
1402          * for indirect item pos_in_item is measured in unformatted node
1403          * pointers. Recalculate to bytes
1404          */
1405         if (flag != M_INSERT
1406             && is_indirect_le_ih(item_head(tbS0, tb->item_pos)))
1407                 tb->pos_in_item *= UNFM_P_SIZE;
1408 
1409         body += balance_leaf_left(tb, ih, body, flag);
1410 
1411         /* tb->lnum[0] > 0 */
1412         /* Calculate new item position */
1413         tb->item_pos -= (tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0));
1414 
1415         balance_leaf_right(tb, ih, body, flag);
1416 
1417         /* tb->rnum[0] > 0 */
1418         RFALSE(tb->blknum[0] > 3,
1419                "PAP-12180: blknum can not be %d. It must be <= 3", tb->blknum[0]);
1420         RFALSE(tb->blknum[0] < 0,
1421                "PAP-12185: blknum can not be %d. It must be >= 0", tb->blknum[0]);
1422 
1423         /*
1424          * if while adding to a node we discover that it is possible to split
1425          * it in two, and merge the left part into the left neighbor and the
1426          * right part into the right neighbor, eliminating the node
1427          */
1428         if (tb->blknum[0] == 0) {       /* node S[0] is empty now */
1429 
1430                 RFALSE(!tb->lnum[0] || !tb->rnum[0],
1431                        "PAP-12190: lnum and rnum must not be zero");
1432                 /*
1433                  * if insertion was done before 0-th position in R[0], right
1434                  * delimiting key of the tb->L[0]'s and left delimiting key are
1435                  * not set correctly
1436                  */
1437                 if (tb->CFL[0]) {
1438                         if (!tb->CFR[0])
1439                                 reiserfs_panic(tb->tb_sb, "vs-12195",
1440                                                "CFR not initialized");
1441                         copy_key(internal_key(tb->CFL[0], tb->lkey[0]),
1442                                  internal_key(tb->CFR[0], tb->rkey[0]));
1443                         do_balance_mark_internal_dirty(tb, tb->CFL[0], 0);
1444                 }
1445 
1446                 reiserfs_invalidate_buffer(tb, tbS0);
1447                 return 0;
1448         }
1449 
1450         balance_leaf_new_nodes(tb, ih, body, insert_key, insert_ptr, flag);
1451 
1452         balance_leaf_finish_node(tb, ih, body, flag);
1453 
1454 #ifdef CONFIG_REISERFS_CHECK
1455         if (flag == M_PASTE && tb->insert_size[0]) {
1456                 print_cur_tb("12290");
1457                 reiserfs_panic(tb->tb_sb,
1458                                "PAP-12290", "insert_size is still not 0 (%d)",
1459                                tb->insert_size[0]);
1460         }
1461 #endif
1462 
1463         /* Leaf level of the tree is balanced (end of balance_leaf) */
1464         return 0;
1465 }
1466 
1467 /* Make empty node */
1468 void make_empty_node(struct buffer_info *bi)
1469 {
1470         struct block_head *blkh;
1471 
1472         RFALSE(bi->bi_bh == NULL, "PAP-12295: pointer to the buffer is NULL");
1473 
1474         blkh = B_BLK_HEAD(bi->bi_bh);
1475         set_blkh_nr_item(blkh, 0);
1476         set_blkh_free_space(blkh, MAX_CHILD_SIZE(bi->bi_bh));
1477 
1478         if (bi->bi_parent)
1479                 B_N_CHILD(bi->bi_parent, bi->bi_position)->dc_size = 0; /* Endian safe if 0 */
1480 }
1481 
1482 /* Get first empty buffer */
1483 struct buffer_head *get_FEB(struct tree_balance *tb)
1484 {
1485         int i;
1486         struct buffer_info bi;
1487 
1488         for (i = 0; i < MAX_FEB_SIZE; i++)
1489                 if (tb->FEB[i] != NULL)
1490                         break;
1491 
1492         if (i == MAX_FEB_SIZE)
1493                 reiserfs_panic(tb->tb_sb, "vs-12300", "FEB list is empty");
1494 
1495         buffer_info_init_bh(tb, &bi, tb->FEB[i]);
1496         make_empty_node(&bi);
1497         set_buffer_uptodate(tb->FEB[i]);
1498         tb->used[i] = tb->FEB[i];
1499         tb->FEB[i] = NULL;
1500 
1501         return tb->used[i];
1502 }
1503 
1504 /* This is now used because reiserfs_free_block has to be able to schedule. */
1505 static void store_thrown(struct tree_balance *tb, struct buffer_head *bh)
1506 {
1507         int i;
1508 
1509         if (buffer_dirty(bh))
1510                 reiserfs_warning(tb->tb_sb, "reiserfs-12320",
1511                                  "called with dirty buffer");
1512         for (i = 0; i < ARRAY_SIZE(tb->thrown); i++)
1513                 if (!tb->thrown[i]) {
1514                         tb->thrown[i] = bh;
1515                         get_bh(bh);     /* free_thrown puts this */
1516                         return;
1517                 }
1518         reiserfs_warning(tb->tb_sb, "reiserfs-12321",
1519                          "too many thrown buffers");
1520 }
1521 
1522 static void free_thrown(struct tree_balance *tb)
1523 {
1524         int i;
1525         b_blocknr_t blocknr;
1526         for (i = 0; i < ARRAY_SIZE(tb->thrown); i++) {
1527                 if (tb->thrown[i]) {
1528                         blocknr = tb->thrown[i]->b_blocknr;
1529                         if (buffer_dirty(tb->thrown[i]))
1530                                 reiserfs_warning(tb->tb_sb, "reiserfs-12322",
1531                                                  "called with dirty buffer %d",
1532                                                  blocknr);
1533                         brelse(tb->thrown[i]);  /* incremented in store_thrown */
1534                         reiserfs_free_block(tb->transaction_handle, NULL,
1535                                             blocknr, 0);
1536                 }
1537         }
1538 }
1539 
1540 void reiserfs_invalidate_buffer(struct tree_balance *tb, struct buffer_head *bh)
1541 {
1542         struct block_head *blkh;
1543         blkh = B_BLK_HEAD(bh);
1544         set_blkh_level(blkh, FREE_LEVEL);
1545         set_blkh_nr_item(blkh, 0);
1546 
1547         clear_buffer_dirty(bh);
1548         store_thrown(tb, bh);
1549 }
1550 
1551 /* Replace n_dest'th key in buffer dest by n_src'th key of buffer src.*/
1552 void replace_key(struct tree_balance *tb, struct buffer_head *dest, int n_dest,
1553                  struct buffer_head *src, int n_src)
1554 {
1555 
1556         RFALSE(dest == NULL || src == NULL,
1557                "vs-12305: source or destination buffer is 0 (src=%p, dest=%p)",
1558                src, dest);
1559         RFALSE(!B_IS_KEYS_LEVEL(dest),
1560                "vs-12310: invalid level (%z) for destination buffer. dest must be leaf",
1561                dest);
1562         RFALSE(n_dest < 0 || n_src < 0,
1563                "vs-12315: src(%d) or dest(%d) key number < 0", n_src, n_dest);
1564         RFALSE(n_dest >= B_NR_ITEMS(dest) || n_src >= B_NR_ITEMS(src),
1565                "vs-12320: src(%d(%d)) or dest(%d(%d)) key number is too big",
1566                n_src, B_NR_ITEMS(src), n_dest, B_NR_ITEMS(dest));
1567 
1568         if (B_IS_ITEMS_LEVEL(src))
1569                 /* source buffer contains leaf node */
1570                 memcpy(internal_key(dest, n_dest), item_head(src, n_src),
1571                        KEY_SIZE);
1572         else
1573                 memcpy(internal_key(dest, n_dest), internal_key(src, n_src),
1574                        KEY_SIZE);
1575 
1576         do_balance_mark_internal_dirty(tb, dest, 0);
1577 }
1578 
1579 int get_left_neighbor_position(struct tree_balance *tb, int h)
1580 {
1581         int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
1582 
1583         RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FL[h] == NULL,
1584                "vs-12325: FL[%d](%p) or F[%d](%p) does not exist",
1585                h, tb->FL[h], h, PATH_H_PPARENT(tb->tb_path, h));
1586 
1587         if (Sh_position == 0)
1588                 return B_NR_ITEMS(tb->FL[h]);
1589         else
1590                 return Sh_position - 1;
1591 }
1592 
1593 int get_right_neighbor_position(struct tree_balance *tb, int h)
1594 {
1595         int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
1596 
1597         RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FR[h] == NULL,
1598                "vs-12330: F[%d](%p) or FR[%d](%p) does not exist",
1599                h, PATH_H_PPARENT(tb->tb_path, h), h, tb->FR[h]);
1600 
1601         if (Sh_position == B_NR_ITEMS(PATH_H_PPARENT(tb->tb_path, h)))
1602                 return 0;
1603         else
1604                 return Sh_position + 1;
1605 }
1606 
1607 #ifdef CONFIG_REISERFS_CHECK
1608 
1609 int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value);
1610 static void check_internal_node(struct super_block *s, struct buffer_head *bh,
1611                                 char *mes)
1612 {
1613         struct disk_child *dc;
1614         int i;
1615 
1616         RFALSE(!bh, "PAP-12336: bh == 0");
1617 
1618         if (!bh || !B_IS_IN_TREE(bh))
1619                 return;
1620 
1621         RFALSE(!buffer_dirty(bh) &&
1622                !(buffer_journaled(bh) || buffer_journal_dirty(bh)),
1623                "PAP-12337: buffer (%b) must be dirty", bh);
1624         dc = B_N_CHILD(bh, 0);
1625 
1626         for (i = 0; i <= B_NR_ITEMS(bh); i++, dc++) {
1627                 if (!is_reusable(s, dc_block_number(dc), 1)) {
1628                         print_cur_tb(mes);
1629                         reiserfs_panic(s, "PAP-12338",
1630                                        "invalid child pointer %y in %b",
1631                                        dc, bh);
1632                 }
1633         }
1634 }
1635 
1636 static int locked_or_not_in_tree(struct tree_balance *tb,
1637                                   struct buffer_head *bh, char *which)
1638 {
1639         if ((!buffer_journal_prepared(bh) && buffer_locked(bh)) ||
1640             !B_IS_IN_TREE(bh)) {
1641                 reiserfs_warning(tb->tb_sb, "vs-12339", "%s (%b)", which, bh);
1642                 return 1;
1643         }
1644         return 0;
1645 }
1646 
1647 static int check_before_balancing(struct tree_balance *tb)
1648 {
1649         int retval = 0;
1650 
1651         if (REISERFS_SB(tb->tb_sb)->cur_tb) {
1652                 reiserfs_panic(tb->tb_sb, "vs-12335", "suspect that schedule "
1653                                "occurred based on cur_tb not being null at "
1654                                "this point in code. do_balance cannot properly "
1655                                "handle concurrent tree accesses on a same "
1656                                "mount point.");
1657         }
1658 
1659         /*
1660          * double check that buffers that we will modify are unlocked.
1661          * (fix_nodes should already have prepped all of these for us).
1662          */
1663         if (tb->lnum[0]) {
1664                 retval |= locked_or_not_in_tree(tb, tb->L[0], "L[0]");
1665                 retval |= locked_or_not_in_tree(tb, tb->FL[0], "FL[0]");
1666                 retval |= locked_or_not_in_tree(tb, tb->CFL[0], "CFL[0]");
1667                 check_leaf(tb->L[0]);
1668         }
1669         if (tb->rnum[0]) {
1670                 retval |= locked_or_not_in_tree(tb, tb->R[0], "R[0]");
1671                 retval |= locked_or_not_in_tree(tb, tb->FR[0], "FR[0]");
1672                 retval |= locked_or_not_in_tree(tb, tb->CFR[0], "CFR[0]");
1673                 check_leaf(tb->R[0]);
1674         }
1675         retval |= locked_or_not_in_tree(tb, PATH_PLAST_BUFFER(tb->tb_path),
1676                                         "S[0]");
1677         check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
1678 
1679         return retval;
1680 }
1681 
1682 static void check_after_balance_leaf(struct tree_balance *tb)
1683 {
1684         if (tb->lnum[0]) {
1685                 if (B_FREE_SPACE(tb->L[0]) !=
1686                     MAX_CHILD_SIZE(tb->L[0]) -
1687                     dc_size(B_N_CHILD
1688                             (tb->FL[0], get_left_neighbor_position(tb, 0)))) {
1689                         print_cur_tb("12221");
1690                         reiserfs_panic(tb->tb_sb, "PAP-12355",
1691                                        "shift to left was incorrect");
1692                 }
1693         }
1694         if (tb->rnum[0]) {
1695                 if (B_FREE_SPACE(tb->R[0]) !=
1696                     MAX_CHILD_SIZE(tb->R[0]) -
1697                     dc_size(B_N_CHILD
1698                             (tb->FR[0], get_right_neighbor_position(tb, 0)))) {
1699                         print_cur_tb("12222");
1700                         reiserfs_panic(tb->tb_sb, "PAP-12360",
1701                                        "shift to right was incorrect");
1702                 }
1703         }
1704         if (PATH_H_PBUFFER(tb->tb_path, 1) &&
1705             (B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0)) !=
1706              (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
1707               dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
1708                                 PATH_H_POSITION(tb->tb_path, 1)))))) {
1709                 int left = B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0));
1710                 int right = (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
1711                              dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
1712                                                PATH_H_POSITION(tb->tb_path,
1713                                                                1))));
1714                 print_cur_tb("12223");
1715                 reiserfs_warning(tb->tb_sb, "reiserfs-12363",
1716                                  "B_FREE_SPACE (PATH_H_PBUFFER(tb->tb_path,0)) = %d; "
1717                                  "MAX_CHILD_SIZE (%d) - dc_size( %y, %d ) [%d] = %d",
1718                                  left,
1719                                  MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)),
1720                                  PATH_H_PBUFFER(tb->tb_path, 1),
1721                                  PATH_H_POSITION(tb->tb_path, 1),
1722                                  dc_size(B_N_CHILD
1723                                          (PATH_H_PBUFFER(tb->tb_path, 1),
1724                                           PATH_H_POSITION(tb->tb_path, 1))),
1725                                  right);
1726                 reiserfs_panic(tb->tb_sb, "PAP-12365", "S is incorrect");
1727         }
1728 }
1729 
1730 static void check_leaf_level(struct tree_balance *tb)
1731 {
1732         check_leaf(tb->L[0]);
1733         check_leaf(tb->R[0]);
1734         check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
1735 }
1736 
1737 static void check_internal_levels(struct tree_balance *tb)
1738 {
1739         int h;
1740 
1741         /* check all internal nodes */
1742         for (h = 1; tb->insert_size[h]; h++) {
1743                 check_internal_node(tb->tb_sb, PATH_H_PBUFFER(tb->tb_path, h),
1744                                     "BAD BUFFER ON PATH");
1745                 if (tb->lnum[h])
1746                         check_internal_node(tb->tb_sb, tb->L[h], "BAD L");
1747                 if (tb->rnum[h])
1748                         check_internal_node(tb->tb_sb, tb->R[h], "BAD R");
1749         }
1750 
1751 }
1752 
1753 #endif
1754 
1755 /*
1756  * Now we have all of the buffers that must be used in balancing of
1757  * the tree.  We rely on the assumption that schedule() will not occur
1758  * while do_balance works. ( Only interrupt handlers are acceptable.)
1759  * We balance the tree according to the analysis made before this,
1760  * using buffers already obtained.  For SMP support it will someday be
1761  * necessary to add ordered locking of tb.
1762  */
1763 
1764 /*
1765  * Some interesting rules of balancing:
1766  * we delete a maximum of two nodes per level per balancing: we never
1767  * delete R, when we delete two of three nodes L, S, R then we move
1768  * them into R.
1769  *
1770  * we only delete L if we are deleting two nodes, if we delete only
1771  * one node we delete S
1772  *
1773  * if we shift leaves then we shift as much as we can: this is a
1774  * deliberate policy of extremism in node packing which results in
1775  * higher average utilization after repeated random balance operations
1776  * at the cost of more memory copies and more balancing as a result of
1777  * small insertions to full nodes.
1778  *
1779  * if we shift internal nodes we try to evenly balance the node
1780  * utilization, with consequent less balancing at the cost of lower
1781  * utilization.
1782  *
1783  * one could argue that the policy for directories in leaves should be
1784  * that of internal nodes, but we will wait until another day to
1785  * evaluate this....  It would be nice to someday measure and prove
1786  * these assumptions as to what is optimal....
1787  */
1788 
1789 static inline void do_balance_starts(struct tree_balance *tb)
1790 {
1791         /* use print_cur_tb() to see initial state of struct tree_balance */
1792 
1793         /* store_print_tb (tb); */
1794 
1795         /* do not delete, just comment it out */
1796         /*
1797         print_tb(flag, PATH_LAST_POSITION(tb->tb_path),
1798                  tb->tb_path->pos_in_item, tb, "check");
1799         */
1800         RFALSE(check_before_balancing(tb), "PAP-12340: locked buffers in TB");
1801 #ifdef CONFIG_REISERFS_CHECK
1802         REISERFS_SB(tb->tb_sb)->cur_tb = tb;
1803 #endif
1804 }
1805 
1806 static inline void do_balance_completed(struct tree_balance *tb)
1807 {
1808 
1809 #ifdef CONFIG_REISERFS_CHECK
1810         check_leaf_level(tb);
1811         check_internal_levels(tb);
1812         REISERFS_SB(tb->tb_sb)->cur_tb = NULL;
1813 #endif
1814 
1815         /*
1816          * reiserfs_free_block is no longer schedule safe.  So, we need to
1817          * put the buffers we want freed on the thrown list during do_balance,
1818          * and then free them now
1819          */
1820 
1821         REISERFS_SB(tb->tb_sb)->s_do_balance++;
1822 
1823         /* release all nodes hold to perform the balancing */
1824         unfix_nodes(tb);
1825 
1826         free_thrown(tb);
1827 }
1828 
1829 /*
1830  * do_balance - balance the tree
1831  *
1832  * @tb: tree_balance structure
1833  * @ih: item header of inserted item
1834  * @body: body of inserted item or bytes to paste
1835  * @flag: 'i' - insert, 'd' - delete, 'c' - cut, 'p' paste
1836  *
1837  * Cut means delete part of an item (includes removing an entry from a
1838  * directory).
1839  *
1840  * Delete means delete whole item.
1841  *
1842  * Insert means add a new item into the tree.
1843  *
1844  * Paste means to append to the end of an existing file or to
1845  * insert a directory entry.
1846  */
1847 void do_balance(struct tree_balance *tb, struct item_head *ih,
1848                 const char *body, int flag)
1849 {
1850         int child_pos;          /* position of a child node in its parent */
1851         int h;                  /* level of the tree being processed */
1852 
1853         /*
1854          * in our processing of one level we sometimes determine what
1855          * must be inserted into the next higher level.  This insertion
1856          * consists of a key or two keys and their corresponding
1857          * pointers
1858          */
1859         struct item_head insert_key[2];
1860 
1861         /* inserted node-ptrs for the next level */
1862         struct buffer_head *insert_ptr[2];
1863 
1864         tb->tb_mode = flag;
1865         tb->need_balance_dirty = 0;
1866 
1867         if (FILESYSTEM_CHANGED_TB(tb)) {
1868                 reiserfs_panic(tb->tb_sb, "clm-6000", "fs generation has "
1869                                "changed");
1870         }
1871         /* if we have no real work to do  */
1872         if (!tb->insert_size[0]) {
1873                 reiserfs_warning(tb->tb_sb, "PAP-12350",
1874                                  "insert_size == 0, mode == %c", flag);
1875                 unfix_nodes(tb);
1876                 return;
1877         }
1878 
1879         atomic_inc(&fs_generation(tb->tb_sb));
1880         do_balance_starts(tb);
1881 
1882         /*
1883          * balance_leaf returns 0 except if combining L R and S into
1884          * one node.  see balance_internal() for explanation of this
1885          * line of code.
1886          */
1887         child_pos = PATH_H_B_ITEM_ORDER(tb->tb_path, 0) +
1888             balance_leaf(tb, ih, body, flag, insert_key, insert_ptr);
1889 
1890 #ifdef CONFIG_REISERFS_CHECK
1891         check_after_balance_leaf(tb);
1892 #endif
1893 
1894         /* Balance internal level of the tree. */
1895         for (h = 1; h < MAX_HEIGHT && tb->insert_size[h]; h++)
1896                 child_pos = balance_internal(tb, h, child_pos, insert_key,
1897                                              insert_ptr);
1898 
1899         do_balance_completed(tb);
1900 }
1901 

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