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1da177e4 LT |
1 | /* |
2 | * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README | |
3 | */ | |
4 | ||
5 | /** | |
6 | ** old_item_num | |
7 | ** old_entry_num | |
8 | ** set_entry_sizes | |
9 | ** create_virtual_node | |
10 | ** check_left | |
11 | ** check_right | |
12 | ** directory_part_size | |
13 | ** get_num_ver | |
14 | ** set_parameters | |
15 | ** is_leaf_removable | |
16 | ** are_leaves_removable | |
17 | ** get_empty_nodes | |
18 | ** get_lfree | |
19 | ** get_rfree | |
20 | ** is_left_neighbor_in_cache | |
21 | ** decrement_key | |
22 | ** get_far_parent | |
23 | ** get_parents | |
24 | ** can_node_be_removed | |
25 | ** ip_check_balance | |
26 | ** dc_check_balance_internal | |
27 | ** dc_check_balance_leaf | |
28 | ** dc_check_balance | |
29 | ** check_balance | |
30 | ** get_direct_parent | |
31 | ** get_neighbors | |
32 | ** fix_nodes | |
33 | ** | |
34 | ** | |
35 | **/ | |
36 | ||
1da177e4 LT |
37 | #include <linux/time.h> |
38 | #include <linux/string.h> | |
39 | #include <linux/reiserfs_fs.h> | |
40 | #include <linux/buffer_head.h> | |
41 | ||
1da177e4 LT |
42 | /* To make any changes in the tree we find a node, that contains item |
43 | to be changed/deleted or position in the node we insert a new item | |
44 | to. We call this node S. To do balancing we need to decide what we | |
45 | will shift to left/right neighbor, or to a new node, where new item | |
46 | will be etc. To make this analysis simpler we build virtual | |
47 | node. Virtual node is an array of items, that will replace items of | |
48 | node S. (For instance if we are going to delete an item, virtual | |
49 | node does not contain it). Virtual node keeps information about | |
50 | item sizes and types, mergeability of first and last items, sizes | |
51 | of all entries in directory item. We use this array of items when | |
52 | calculating what we can shift to neighbors and how many nodes we | |
53 | have to have if we do not any shiftings, if we shift to left/right | |
54 | neighbor or to both. */ | |
55 | ||
1da177e4 | 56 | /* taking item number in virtual node, returns number of item, that it has in source buffer */ |
bd4c625c | 57 | static inline int old_item_num(int new_num, int affected_item_num, int mode) |
1da177e4 | 58 | { |
bd4c625c LT |
59 | if (mode == M_PASTE || mode == M_CUT || new_num < affected_item_num) |
60 | return new_num; | |
1da177e4 | 61 | |
bd4c625c | 62 | if (mode == M_INSERT) { |
1da177e4 | 63 | |
bd4c625c LT |
64 | RFALSE(new_num == 0, |
65 | "vs-8005: for INSERT mode and item number of inserted item"); | |
1da177e4 | 66 | |
bd4c625c LT |
67 | return new_num - 1; |
68 | } | |
1da177e4 | 69 | |
bd4c625c LT |
70 | RFALSE(mode != M_DELETE, |
71 | "vs-8010: old_item_num: mode must be M_DELETE (mode = \'%c\'", | |
72 | mode); | |
73 | /* delete mode */ | |
74 | return new_num + 1; | |
1da177e4 LT |
75 | } |
76 | ||
bd4c625c | 77 | static void create_virtual_node(struct tree_balance *tb, int h) |
1da177e4 | 78 | { |
bd4c625c LT |
79 | struct item_head *ih; |
80 | struct virtual_node *vn = tb->tb_vn; | |
81 | int new_num; | |
82 | struct buffer_head *Sh; /* this comes from tb->S[h] */ | |
1da177e4 | 83 | |
bd4c625c | 84 | Sh = PATH_H_PBUFFER(tb->tb_path, h); |
1da177e4 | 85 | |
bd4c625c LT |
86 | /* size of changed node */ |
87 | vn->vn_size = | |
88 | MAX_CHILD_SIZE(Sh) - B_FREE_SPACE(Sh) + tb->insert_size[h]; | |
1da177e4 | 89 | |
bd4c625c LT |
90 | /* for internal nodes array if virtual items is not created */ |
91 | if (h) { | |
92 | vn->vn_nr_item = (vn->vn_size - DC_SIZE) / (DC_SIZE + KEY_SIZE); | |
93 | return; | |
1da177e4 | 94 | } |
1da177e4 | 95 | |
bd4c625c LT |
96 | /* number of items in virtual node */ |
97 | vn->vn_nr_item = | |
98 | B_NR_ITEMS(Sh) + ((vn->vn_mode == M_INSERT) ? 1 : 0) - | |
99 | ((vn->vn_mode == M_DELETE) ? 1 : 0); | |
100 | ||
101 | /* first virtual item */ | |
102 | vn->vn_vi = (struct virtual_item *)(tb->tb_vn + 1); | |
103 | memset(vn->vn_vi, 0, vn->vn_nr_item * sizeof(struct virtual_item)); | |
104 | vn->vn_free_ptr += vn->vn_nr_item * sizeof(struct virtual_item); | |
105 | ||
106 | /* first item in the node */ | |
107 | ih = B_N_PITEM_HEAD(Sh, 0); | |
108 | ||
109 | /* define the mergeability for 0-th item (if it is not being deleted) */ | |
110 | if (op_is_left_mergeable(&(ih->ih_key), Sh->b_size) | |
111 | && (vn->vn_mode != M_DELETE || vn->vn_affected_item_num)) | |
112 | vn->vn_vi[0].vi_type |= VI_TYPE_LEFT_MERGEABLE; | |
113 | ||
114 | /* go through all items those remain in the virtual node (except for the new (inserted) one) */ | |
115 | for (new_num = 0; new_num < vn->vn_nr_item; new_num++) { | |
116 | int j; | |
117 | struct virtual_item *vi = vn->vn_vi + new_num; | |
118 | int is_affected = | |
119 | ((new_num != vn->vn_affected_item_num) ? 0 : 1); | |
120 | ||
121 | if (is_affected && vn->vn_mode == M_INSERT) | |
122 | continue; | |
123 | ||
124 | /* get item number in source node */ | |
125 | j = old_item_num(new_num, vn->vn_affected_item_num, | |
126 | vn->vn_mode); | |
127 | ||
128 | vi->vi_item_len += ih_item_len(ih + j) + IH_SIZE; | |
129 | vi->vi_ih = ih + j; | |
130 | vi->vi_item = B_I_PITEM(Sh, ih + j); | |
131 | vi->vi_uarea = vn->vn_free_ptr; | |
132 | ||
133 | // FIXME: there is no check, that item operation did not | |
134 | // consume too much memory | |
135 | vn->vn_free_ptr += | |
136 | op_create_vi(vn, vi, is_affected, tb->insert_size[0]); | |
137 | if (tb->vn_buf + tb->vn_buf_size < vn->vn_free_ptr) | |
c3a9c210 | 138 | reiserfs_panic(tb->tb_sb, "vs-8030", |
bd4c625c LT |
139 | "virtual node space consumed"); |
140 | ||
141 | if (!is_affected) | |
142 | /* this is not being changed */ | |
143 | continue; | |
144 | ||
145 | if (vn->vn_mode == M_PASTE || vn->vn_mode == M_CUT) { | |
146 | vn->vn_vi[new_num].vi_item_len += tb->insert_size[0]; | |
147 | vi->vi_new_data = vn->vn_data; // pointer to data which is going to be pasted | |
148 | } | |
1da177e4 | 149 | } |
bd4c625c LT |
150 | |
151 | /* virtual inserted item is not defined yet */ | |
152 | if (vn->vn_mode == M_INSERT) { | |
153 | struct virtual_item *vi = vn->vn_vi + vn->vn_affected_item_num; | |
154 | ||
9dce07f1 | 155 | RFALSE(vn->vn_ins_ih == NULL, |
bd4c625c LT |
156 | "vs-8040: item header of inserted item is not specified"); |
157 | vi->vi_item_len = tb->insert_size[0]; | |
158 | vi->vi_ih = vn->vn_ins_ih; | |
159 | vi->vi_item = vn->vn_data; | |
160 | vi->vi_uarea = vn->vn_free_ptr; | |
161 | ||
162 | op_create_vi(vn, vi, 0 /*not pasted or cut */ , | |
163 | tb->insert_size[0]); | |
164 | } | |
165 | ||
166 | /* set right merge flag we take right delimiting key and check whether it is a mergeable item */ | |
167 | if (tb->CFR[0]) { | |
168 | struct reiserfs_key *key; | |
169 | ||
170 | key = B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0]); | |
171 | if (op_is_left_mergeable(key, Sh->b_size) | |
172 | && (vn->vn_mode != M_DELETE | |
173 | || vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1)) | |
174 | vn->vn_vi[vn->vn_nr_item - 1].vi_type |= | |
175 | VI_TYPE_RIGHT_MERGEABLE; | |
176 | ||
177 | #ifdef CONFIG_REISERFS_CHECK | |
178 | if (op_is_left_mergeable(key, Sh->b_size) && | |
179 | !(vn->vn_mode != M_DELETE | |
180 | || vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1)) { | |
181 | /* we delete last item and it could be merged with right neighbor's first item */ | |
182 | if (! | |
183 | (B_NR_ITEMS(Sh) == 1 | |
184 | && is_direntry_le_ih(B_N_PITEM_HEAD(Sh, 0)) | |
185 | && I_ENTRY_COUNT(B_N_PITEM_HEAD(Sh, 0)) == 1)) { | |
186 | /* node contains more than 1 item, or item is not directory item, or this item contains more than 1 entry */ | |
187 | print_block(Sh, 0, -1, -1); | |
c3a9c210 JM |
188 | reiserfs_panic(tb->tb_sb, "vs-8045", |
189 | "rdkey %k, affected item==%d " | |
190 | "(mode==%c) Must be %c", | |
bd4c625c LT |
191 | key, vn->vn_affected_item_num, |
192 | vn->vn_mode, M_DELETE); | |
cd02b966 | 193 | } |
bd4c625c | 194 | } |
1da177e4 | 195 | #endif |
1da177e4 | 196 | |
bd4c625c LT |
197 | } |
198 | } | |
1da177e4 LT |
199 | |
200 | /* using virtual node check, how many items can be shifted to left | |
201 | neighbor */ | |
bd4c625c | 202 | static void check_left(struct tree_balance *tb, int h, int cur_free) |
1da177e4 | 203 | { |
bd4c625c LT |
204 | int i; |
205 | struct virtual_node *vn = tb->tb_vn; | |
206 | struct virtual_item *vi; | |
207 | int d_size, ih_size; | |
1da177e4 | 208 | |
bd4c625c | 209 | RFALSE(cur_free < 0, "vs-8050: cur_free (%d) < 0", cur_free); |
1da177e4 | 210 | |
bd4c625c LT |
211 | /* internal level */ |
212 | if (h > 0) { | |
213 | tb->lnum[h] = cur_free / (DC_SIZE + KEY_SIZE); | |
214 | return; | |
215 | } | |
1da177e4 | 216 | |
bd4c625c | 217 | /* leaf level */ |
1da177e4 | 218 | |
bd4c625c LT |
219 | if (!cur_free || !vn->vn_nr_item) { |
220 | /* no free space or nothing to move */ | |
221 | tb->lnum[h] = 0; | |
222 | tb->lbytes = -1; | |
223 | return; | |
224 | } | |
1da177e4 | 225 | |
bd4c625c LT |
226 | RFALSE(!PATH_H_PPARENT(tb->tb_path, 0), |
227 | "vs-8055: parent does not exist or invalid"); | |
1da177e4 | 228 | |
bd4c625c LT |
229 | vi = vn->vn_vi; |
230 | if ((unsigned int)cur_free >= | |
231 | (vn->vn_size - | |
232 | ((vi->vi_type & VI_TYPE_LEFT_MERGEABLE) ? IH_SIZE : 0))) { | |
233 | /* all contents of S[0] fits into L[0] */ | |
1da177e4 | 234 | |
bd4c625c LT |
235 | RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE, |
236 | "vs-8055: invalid mode or balance condition failed"); | |
1da177e4 | 237 | |
bd4c625c LT |
238 | tb->lnum[0] = vn->vn_nr_item; |
239 | tb->lbytes = -1; | |
240 | return; | |
1da177e4 | 241 | } |
bd4c625c LT |
242 | |
243 | d_size = 0, ih_size = IH_SIZE; | |
244 | ||
245 | /* first item may be merge with last item in left neighbor */ | |
246 | if (vi->vi_type & VI_TYPE_LEFT_MERGEABLE) | |
247 | d_size = -((int)IH_SIZE), ih_size = 0; | |
248 | ||
249 | tb->lnum[0] = 0; | |
250 | for (i = 0; i < vn->vn_nr_item; | |
251 | i++, ih_size = IH_SIZE, d_size = 0, vi++) { | |
252 | d_size += vi->vi_item_len; | |
253 | if (cur_free >= d_size) { | |
254 | /* the item can be shifted entirely */ | |
255 | cur_free -= d_size; | |
256 | tb->lnum[0]++; | |
257 | continue; | |
258 | } | |
259 | ||
260 | /* the item cannot be shifted entirely, try to split it */ | |
261 | /* check whether L[0] can hold ih and at least one byte of the item body */ | |
262 | if (cur_free <= ih_size) { | |
263 | /* cannot shift even a part of the current item */ | |
264 | tb->lbytes = -1; | |
265 | return; | |
266 | } | |
267 | cur_free -= ih_size; | |
268 | ||
269 | tb->lbytes = op_check_left(vi, cur_free, 0, 0); | |
270 | if (tb->lbytes != -1) | |
271 | /* count partially shifted item */ | |
272 | tb->lnum[0]++; | |
273 | ||
274 | break; | |
1da177e4 | 275 | } |
1da177e4 | 276 | |
bd4c625c LT |
277 | return; |
278 | } | |
1da177e4 LT |
279 | |
280 | /* using virtual node check, how many items can be shifted to right | |
281 | neighbor */ | |
bd4c625c | 282 | static void check_right(struct tree_balance *tb, int h, int cur_free) |
1da177e4 | 283 | { |
bd4c625c LT |
284 | int i; |
285 | struct virtual_node *vn = tb->tb_vn; | |
286 | struct virtual_item *vi; | |
287 | int d_size, ih_size; | |
288 | ||
289 | RFALSE(cur_free < 0, "vs-8070: cur_free < 0"); | |
290 | ||
291 | /* internal level */ | |
292 | if (h > 0) { | |
293 | tb->rnum[h] = cur_free / (DC_SIZE + KEY_SIZE); | |
294 | return; | |
1da177e4 | 295 | } |
bd4c625c LT |
296 | |
297 | /* leaf level */ | |
298 | ||
299 | if (!cur_free || !vn->vn_nr_item) { | |
300 | /* no free space */ | |
301 | tb->rnum[h] = 0; | |
302 | tb->rbytes = -1; | |
303 | return; | |
1da177e4 | 304 | } |
1da177e4 | 305 | |
bd4c625c LT |
306 | RFALSE(!PATH_H_PPARENT(tb->tb_path, 0), |
307 | "vs-8075: parent does not exist or invalid"); | |
308 | ||
309 | vi = vn->vn_vi + vn->vn_nr_item - 1; | |
310 | if ((unsigned int)cur_free >= | |
311 | (vn->vn_size - | |
312 | ((vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) ? IH_SIZE : 0))) { | |
313 | /* all contents of S[0] fits into R[0] */ | |
314 | ||
315 | RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE, | |
316 | "vs-8080: invalid mode or balance condition failed"); | |
317 | ||
318 | tb->rnum[h] = vn->vn_nr_item; | |
319 | tb->rbytes = -1; | |
320 | return; | |
321 | } | |
322 | ||
323 | d_size = 0, ih_size = IH_SIZE; | |
324 | ||
325 | /* last item may be merge with first item in right neighbor */ | |
326 | if (vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) | |
327 | d_size = -(int)IH_SIZE, ih_size = 0; | |
328 | ||
329 | tb->rnum[0] = 0; | |
330 | for (i = vn->vn_nr_item - 1; i >= 0; | |
331 | i--, d_size = 0, ih_size = IH_SIZE, vi--) { | |
332 | d_size += vi->vi_item_len; | |
333 | if (cur_free >= d_size) { | |
334 | /* the item can be shifted entirely */ | |
335 | cur_free -= d_size; | |
336 | tb->rnum[0]++; | |
337 | continue; | |
338 | } | |
339 | ||
340 | /* check whether R[0] can hold ih and at least one byte of the item body */ | |
341 | if (cur_free <= ih_size) { /* cannot shift even a part of the current item */ | |
342 | tb->rbytes = -1; | |
343 | return; | |
344 | } | |
345 | ||
346 | /* R[0] can hold the header of the item and at least one byte of its body */ | |
347 | cur_free -= ih_size; /* cur_free is still > 0 */ | |
348 | ||
349 | tb->rbytes = op_check_right(vi, cur_free); | |
350 | if (tb->rbytes != -1) | |
351 | /* count partially shifted item */ | |
352 | tb->rnum[0]++; | |
353 | ||
354 | break; | |
355 | } | |
356 | ||
357 | return; | |
358 | } | |
1da177e4 LT |
359 | |
360 | /* | |
361 | * from - number of items, which are shifted to left neighbor entirely | |
362 | * to - number of item, which are shifted to right neighbor entirely | |
363 | * from_bytes - number of bytes of boundary item (or directory entries) which are shifted to left neighbor | |
364 | * to_bytes - number of bytes of boundary item (or directory entries) which are shifted to right neighbor */ | |
bd4c625c LT |
365 | static int get_num_ver(int mode, struct tree_balance *tb, int h, |
366 | int from, int from_bytes, | |
367 | int to, int to_bytes, short *snum012, int flow) | |
1da177e4 | 368 | { |
bd4c625c LT |
369 | int i; |
370 | int cur_free; | |
371 | // int bytes; | |
372 | int units; | |
373 | struct virtual_node *vn = tb->tb_vn; | |
374 | // struct virtual_item * vi; | |
375 | ||
376 | int total_node_size, max_node_size, current_item_size; | |
377 | int needed_nodes; | |
378 | int start_item, /* position of item we start filling node from */ | |
379 | end_item, /* position of item we finish filling node by */ | |
380 | start_bytes, /* number of first bytes (entries for directory) of start_item-th item | |
381 | we do not include into node that is being filled */ | |
382 | end_bytes; /* number of last bytes (entries for directory) of end_item-th item | |
383 | we do node include into node that is being filled */ | |
384 | int split_item_positions[2]; /* these are positions in virtual item of | |
385 | items, that are split between S[0] and | |
386 | S1new and S1new and S2new */ | |
387 | ||
388 | split_item_positions[0] = -1; | |
389 | split_item_positions[1] = -1; | |
390 | ||
391 | /* We only create additional nodes if we are in insert or paste mode | |
392 | or we are in replace mode at the internal level. If h is 0 and | |
393 | the mode is M_REPLACE then in fix_nodes we change the mode to | |
394 | paste or insert before we get here in the code. */ | |
395 | RFALSE(tb->insert_size[h] < 0 || (mode != M_INSERT && mode != M_PASTE), | |
396 | "vs-8100: insert_size < 0 in overflow"); | |
397 | ||
398 | max_node_size = MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, h)); | |
399 | ||
400 | /* snum012 [0-2] - number of items, that lay | |
401 | to S[0], first new node and second new node */ | |
402 | snum012[3] = -1; /* s1bytes */ | |
403 | snum012[4] = -1; /* s2bytes */ | |
404 | ||
405 | /* internal level */ | |
406 | if (h > 0) { | |
407 | i = ((to - from) * (KEY_SIZE + DC_SIZE) + DC_SIZE); | |
408 | if (i == max_node_size) | |
409 | return 1; | |
410 | return (i / max_node_size + 1); | |
1da177e4 LT |
411 | } |
412 | ||
bd4c625c LT |
413 | /* leaf level */ |
414 | needed_nodes = 1; | |
415 | total_node_size = 0; | |
416 | cur_free = max_node_size; | |
417 | ||
418 | // start from 'from'-th item | |
419 | start_item = from; | |
420 | // skip its first 'start_bytes' units | |
421 | start_bytes = ((from_bytes != -1) ? from_bytes : 0); | |
422 | ||
423 | // last included item is the 'end_item'-th one | |
424 | end_item = vn->vn_nr_item - to - 1; | |
425 | // do not count last 'end_bytes' units of 'end_item'-th item | |
426 | end_bytes = (to_bytes != -1) ? to_bytes : 0; | |
427 | ||
428 | /* go through all item beginning from the start_item-th item and ending by | |
429 | the end_item-th item. Do not count first 'start_bytes' units of | |
430 | 'start_item'-th item and last 'end_bytes' of 'end_item'-th item */ | |
431 | ||
432 | for (i = start_item; i <= end_item; i++) { | |
433 | struct virtual_item *vi = vn->vn_vi + i; | |
434 | int skip_from_end = ((i == end_item) ? end_bytes : 0); | |
435 | ||
436 | RFALSE(needed_nodes > 3, "vs-8105: too many nodes are needed"); | |
437 | ||
438 | /* get size of current item */ | |
439 | current_item_size = vi->vi_item_len; | |
440 | ||
441 | /* do not take in calculation head part (from_bytes) of from-th item */ | |
442 | current_item_size -= | |
443 | op_part_size(vi, 0 /*from start */ , start_bytes); | |
444 | ||
445 | /* do not take in calculation tail part of last item */ | |
446 | current_item_size -= | |
447 | op_part_size(vi, 1 /*from end */ , skip_from_end); | |
448 | ||
449 | /* if item fits into current node entierly */ | |
450 | if (total_node_size + current_item_size <= max_node_size) { | |
451 | snum012[needed_nodes - 1]++; | |
452 | total_node_size += current_item_size; | |
453 | start_bytes = 0; | |
454 | continue; | |
455 | } | |
456 | ||
457 | if (current_item_size > max_node_size) { | |
458 | /* virtual item length is longer, than max size of item in | |
459 | a node. It is impossible for direct item */ | |
460 | RFALSE(is_direct_le_ih(vi->vi_ih), | |
461 | "vs-8110: " | |
462 | "direct item length is %d. It can not be longer than %d", | |
463 | current_item_size, max_node_size); | |
464 | /* we will try to split it */ | |
465 | flow = 1; | |
466 | } | |
467 | ||
468 | if (!flow) { | |
469 | /* as we do not split items, take new node and continue */ | |
470 | needed_nodes++; | |
471 | i--; | |
472 | total_node_size = 0; | |
473 | continue; | |
474 | } | |
475 | // calculate number of item units which fit into node being | |
476 | // filled | |
477 | { | |
478 | int free_space; | |
479 | ||
480 | free_space = max_node_size - total_node_size - IH_SIZE; | |
481 | units = | |
482 | op_check_left(vi, free_space, start_bytes, | |
483 | skip_from_end); | |
484 | if (units == -1) { | |
485 | /* nothing fits into current node, take new node and continue */ | |
486 | needed_nodes++, i--, total_node_size = 0; | |
487 | continue; | |
488 | } | |
489 | } | |
490 | ||
491 | /* something fits into the current node */ | |
492 | //if (snum012[3] != -1 || needed_nodes != 1) | |
493 | // reiserfs_panic (tb->tb_sb, "vs-8115: get_num_ver: too many nodes required"); | |
494 | //snum012[needed_nodes - 1 + 3] = op_unit_num (vi) - start_bytes - units; | |
495 | start_bytes += units; | |
496 | snum012[needed_nodes - 1 + 3] = units; | |
497 | ||
498 | if (needed_nodes > 2) | |
45b03d5e JM |
499 | reiserfs_warning(tb->tb_sb, "vs-8111", |
500 | "split_item_position is out of range"); | |
bd4c625c LT |
501 | snum012[needed_nodes - 1]++; |
502 | split_item_positions[needed_nodes - 1] = i; | |
503 | needed_nodes++; | |
504 | /* continue from the same item with start_bytes != -1 */ | |
505 | start_item = i; | |
506 | i--; | |
507 | total_node_size = 0; | |
1da177e4 LT |
508 | } |
509 | ||
bd4c625c LT |
510 | // sum012[4] (if it is not -1) contains number of units of which |
511 | // are to be in S1new, snum012[3] - to be in S0. They are supposed | |
512 | // to be S1bytes and S2bytes correspondingly, so recalculate | |
513 | if (snum012[4] > 0) { | |
514 | int split_item_num; | |
515 | int bytes_to_r, bytes_to_l; | |
516 | int bytes_to_S1new; | |
517 | ||
518 | split_item_num = split_item_positions[1]; | |
519 | bytes_to_l = | |
520 | ((from == split_item_num | |
521 | && from_bytes != -1) ? from_bytes : 0); | |
522 | bytes_to_r = | |
523 | ((end_item == split_item_num | |
524 | && end_bytes != -1) ? end_bytes : 0); | |
525 | bytes_to_S1new = | |
526 | ((split_item_positions[0] == | |
527 | split_item_positions[1]) ? snum012[3] : 0); | |
528 | ||
529 | // s2bytes | |
530 | snum012[4] = | |
531 | op_unit_num(&vn->vn_vi[split_item_num]) - snum012[4] - | |
532 | bytes_to_r - bytes_to_l - bytes_to_S1new; | |
533 | ||
534 | if (vn->vn_vi[split_item_num].vi_index != TYPE_DIRENTRY && | |
535 | vn->vn_vi[split_item_num].vi_index != TYPE_INDIRECT) | |
45b03d5e JM |
536 | reiserfs_warning(tb->tb_sb, "vs-8115", |
537 | "not directory or indirect item"); | |
1da177e4 LT |
538 | } |
539 | ||
bd4c625c LT |
540 | /* now we know S2bytes, calculate S1bytes */ |
541 | if (snum012[3] > 0) { | |
542 | int split_item_num; | |
543 | int bytes_to_r, bytes_to_l; | |
544 | int bytes_to_S2new; | |
545 | ||
546 | split_item_num = split_item_positions[0]; | |
547 | bytes_to_l = | |
548 | ((from == split_item_num | |
549 | && from_bytes != -1) ? from_bytes : 0); | |
550 | bytes_to_r = | |
551 | ((end_item == split_item_num | |
552 | && end_bytes != -1) ? end_bytes : 0); | |
553 | bytes_to_S2new = | |
554 | ((split_item_positions[0] == split_item_positions[1] | |
555 | && snum012[4] != -1) ? snum012[4] : 0); | |
556 | ||
557 | // s1bytes | |
558 | snum012[3] = | |
559 | op_unit_num(&vn->vn_vi[split_item_num]) - snum012[3] - | |
560 | bytes_to_r - bytes_to_l - bytes_to_S2new; | |
1da177e4 LT |
561 | } |
562 | ||
bd4c625c | 563 | return needed_nodes; |
1da177e4 LT |
564 | } |
565 | ||
1da177e4 | 566 | #ifdef CONFIG_REISERFS_CHECK |
bd4c625c | 567 | extern struct tree_balance *cur_tb; |
1da177e4 LT |
568 | #endif |
569 | ||
1da177e4 LT |
570 | /* Set parameters for balancing. |
571 | * Performs write of results of analysis of balancing into structure tb, | |
572 | * where it will later be used by the functions that actually do the balancing. | |
573 | * Parameters: | |
574 | * tb tree_balance structure; | |
575 | * h current level of the node; | |
576 | * lnum number of items from S[h] that must be shifted to L[h]; | |
577 | * rnum number of items from S[h] that must be shifted to R[h]; | |
578 | * blk_num number of blocks that S[h] will be splitted into; | |
579 | * s012 number of items that fall into splitted nodes. | |
580 | * lbytes number of bytes which flow to the left neighbor from the item that is not | |
581 | * not shifted entirely | |
582 | * rbytes number of bytes which flow to the right neighbor from the item that is not | |
583 | * not shifted entirely | |
584 | * s1bytes number of bytes which flow to the first new node when S[0] splits (this number is contained in s012 array) | |
585 | */ | |
586 | ||
bd4c625c LT |
587 | static void set_parameters(struct tree_balance *tb, int h, int lnum, |
588 | int rnum, int blk_num, short *s012, int lb, int rb) | |
1da177e4 LT |
589 | { |
590 | ||
bd4c625c LT |
591 | tb->lnum[h] = lnum; |
592 | tb->rnum[h] = rnum; | |
593 | tb->blknum[h] = blk_num; | |
1da177e4 | 594 | |
bd4c625c LT |
595 | if (h == 0) { /* only for leaf level */ |
596 | if (s012 != NULL) { | |
597 | tb->s0num = *s012++, | |
598 | tb->s1num = *s012++, tb->s2num = *s012++; | |
599 | tb->s1bytes = *s012++; | |
600 | tb->s2bytes = *s012; | |
601 | } | |
602 | tb->lbytes = lb; | |
603 | tb->rbytes = rb; | |
1da177e4 | 604 | } |
bd4c625c LT |
605 | PROC_INFO_ADD(tb->tb_sb, lnum[h], lnum); |
606 | PROC_INFO_ADD(tb->tb_sb, rnum[h], rnum); | |
1da177e4 | 607 | |
bd4c625c LT |
608 | PROC_INFO_ADD(tb->tb_sb, lbytes[h], lb); |
609 | PROC_INFO_ADD(tb->tb_sb, rbytes[h], rb); | |
610 | } | |
1da177e4 LT |
611 | |
612 | /* check, does node disappear if we shift tb->lnum[0] items to left | |
613 | neighbor and tb->rnum[0] to the right one. */ | |
bd4c625c | 614 | static int is_leaf_removable(struct tree_balance *tb) |
1da177e4 | 615 | { |
bd4c625c LT |
616 | struct virtual_node *vn = tb->tb_vn; |
617 | int to_left, to_right; | |
618 | int size; | |
619 | int remain_items; | |
620 | ||
621 | /* number of items, that will be shifted to left (right) neighbor | |
622 | entirely */ | |
623 | to_left = tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0); | |
624 | to_right = tb->rnum[0] - ((tb->rbytes != -1) ? 1 : 0); | |
625 | remain_items = vn->vn_nr_item; | |
626 | ||
627 | /* how many items remain in S[0] after shiftings to neighbors */ | |
628 | remain_items -= (to_left + to_right); | |
629 | ||
630 | if (remain_items < 1) { | |
631 | /* all content of node can be shifted to neighbors */ | |
632 | set_parameters(tb, 0, to_left, vn->vn_nr_item - to_left, 0, | |
633 | NULL, -1, -1); | |
634 | return 1; | |
635 | } | |
1da177e4 | 636 | |
bd4c625c LT |
637 | if (remain_items > 1 || tb->lbytes == -1 || tb->rbytes == -1) |
638 | /* S[0] is not removable */ | |
639 | return 0; | |
640 | ||
641 | /* check, whether we can divide 1 remaining item between neighbors */ | |
642 | ||
643 | /* get size of remaining item (in item units) */ | |
644 | size = op_unit_num(&(vn->vn_vi[to_left])); | |
645 | ||
646 | if (tb->lbytes + tb->rbytes >= size) { | |
647 | set_parameters(tb, 0, to_left + 1, to_right + 1, 0, NULL, | |
648 | tb->lbytes, -1); | |
649 | return 1; | |
650 | } | |
651 | ||
652 | return 0; | |
653 | } | |
1da177e4 LT |
654 | |
655 | /* check whether L, S, R can be joined in one node */ | |
bd4c625c | 656 | static int are_leaves_removable(struct tree_balance *tb, int lfree, int rfree) |
1da177e4 | 657 | { |
bd4c625c LT |
658 | struct virtual_node *vn = tb->tb_vn; |
659 | int ih_size; | |
660 | struct buffer_head *S0; | |
661 | ||
662 | S0 = PATH_H_PBUFFER(tb->tb_path, 0); | |
663 | ||
664 | ih_size = 0; | |
665 | if (vn->vn_nr_item) { | |
666 | if (vn->vn_vi[0].vi_type & VI_TYPE_LEFT_MERGEABLE) | |
667 | ih_size += IH_SIZE; | |
668 | ||
669 | if (vn->vn_vi[vn->vn_nr_item - 1]. | |
670 | vi_type & VI_TYPE_RIGHT_MERGEABLE) | |
671 | ih_size += IH_SIZE; | |
672 | } else { | |
673 | /* there was only one item and it will be deleted */ | |
674 | struct item_head *ih; | |
675 | ||
676 | RFALSE(B_NR_ITEMS(S0) != 1, | |
677 | "vs-8125: item number must be 1: it is %d", | |
678 | B_NR_ITEMS(S0)); | |
679 | ||
680 | ih = B_N_PITEM_HEAD(S0, 0); | |
681 | if (tb->CFR[0] | |
682 | && !comp_short_le_keys(&(ih->ih_key), | |
683 | B_N_PDELIM_KEY(tb->CFR[0], | |
684 | tb->rkey[0]))) | |
685 | if (is_direntry_le_ih(ih)) { | |
686 | /* Directory must be in correct state here: that is | |
687 | somewhere at the left side should exist first directory | |
688 | item. But the item being deleted can not be that first | |
689 | one because its right neighbor is item of the same | |
690 | directory. (But first item always gets deleted in last | |
691 | turn). So, neighbors of deleted item can be merged, so | |
692 | we can save ih_size */ | |
693 | ih_size = IH_SIZE; | |
694 | ||
695 | /* we might check that left neighbor exists and is of the | |
696 | same directory */ | |
697 | RFALSE(le_ih_k_offset(ih) == DOT_OFFSET, | |
698 | "vs-8130: first directory item can not be removed until directory is not empty"); | |
699 | } | |
1da177e4 | 700 | |
bd4c625c LT |
701 | } |
702 | ||
703 | if (MAX_CHILD_SIZE(S0) + vn->vn_size <= rfree + lfree + ih_size) { | |
704 | set_parameters(tb, 0, -1, -1, -1, NULL, -1, -1); | |
705 | PROC_INFO_INC(tb->tb_sb, leaves_removable); | |
706 | return 1; | |
707 | } | |
708 | return 0; | |
1da177e4 | 709 | |
bd4c625c | 710 | } |
1da177e4 LT |
711 | |
712 | /* when we do not split item, lnum and rnum are numbers of entire items */ | |
713 | #define SET_PAR_SHIFT_LEFT \ | |
714 | if (h)\ | |
715 | {\ | |
716 | int to_l;\ | |
717 | \ | |
718 | to_l = (MAX_NR_KEY(Sh)+1 - lpar + vn->vn_nr_item + 1) / 2 -\ | |
719 | (MAX_NR_KEY(Sh) + 1 - lpar);\ | |
720 | \ | |
721 | set_parameters (tb, h, to_l, 0, lnver, NULL, -1, -1);\ | |
722 | }\ | |
723 | else \ | |
724 | {\ | |
725 | if (lset==LEFT_SHIFT_FLOW)\ | |
726 | set_parameters (tb, h, lpar, 0, lnver, snum012+lset,\ | |
727 | tb->lbytes, -1);\ | |
728 | else\ | |
729 | set_parameters (tb, h, lpar - (tb->lbytes!=-1), 0, lnver, snum012+lset,\ | |
730 | -1, -1);\ | |
731 | } | |
732 | ||
1da177e4 LT |
733 | #define SET_PAR_SHIFT_RIGHT \ |
734 | if (h)\ | |
735 | {\ | |
736 | int to_r;\ | |
737 | \ | |
738 | to_r = (MAX_NR_KEY(Sh)+1 - rpar + vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - rpar);\ | |
739 | \ | |
740 | set_parameters (tb, h, 0, to_r, rnver, NULL, -1, -1);\ | |
741 | }\ | |
742 | else \ | |
743 | {\ | |
744 | if (rset==RIGHT_SHIFT_FLOW)\ | |
745 | set_parameters (tb, h, 0, rpar, rnver, snum012+rset,\ | |
746 | -1, tb->rbytes);\ | |
747 | else\ | |
748 | set_parameters (tb, h, 0, rpar - (tb->rbytes!=-1), rnver, snum012+rset,\ | |
749 | -1, -1);\ | |
750 | } | |
751 | ||
bd4c625c LT |
752 | static void free_buffers_in_tb(struct tree_balance *p_s_tb) |
753 | { | |
754 | int n_counter; | |
755 | ||
756 | decrement_counters_in_path(p_s_tb->tb_path); | |
757 | ||
758 | for (n_counter = 0; n_counter < MAX_HEIGHT; n_counter++) { | |
759 | decrement_bcount(p_s_tb->L[n_counter]); | |
760 | p_s_tb->L[n_counter] = NULL; | |
761 | decrement_bcount(p_s_tb->R[n_counter]); | |
762 | p_s_tb->R[n_counter] = NULL; | |
763 | decrement_bcount(p_s_tb->FL[n_counter]); | |
764 | p_s_tb->FL[n_counter] = NULL; | |
765 | decrement_bcount(p_s_tb->FR[n_counter]); | |
766 | p_s_tb->FR[n_counter] = NULL; | |
767 | decrement_bcount(p_s_tb->CFL[n_counter]); | |
768 | p_s_tb->CFL[n_counter] = NULL; | |
769 | decrement_bcount(p_s_tb->CFR[n_counter]); | |
770 | p_s_tb->CFR[n_counter] = NULL; | |
771 | } | |
1da177e4 LT |
772 | } |
773 | ||
1da177e4 LT |
774 | /* Get new buffers for storing new nodes that are created while balancing. |
775 | * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; | |
776 | * CARRY_ON - schedule didn't occur while the function worked; | |
777 | * NO_DISK_SPACE - no disk space. | |
778 | */ | |
779 | /* The function is NOT SCHEDULE-SAFE! */ | |
bd4c625c LT |
780 | static int get_empty_nodes(struct tree_balance *p_s_tb, int n_h) |
781 | { | |
782 | struct buffer_head *p_s_new_bh, | |
783 | *p_s_Sh = PATH_H_PBUFFER(p_s_tb->tb_path, n_h); | |
784 | b_blocknr_t *p_n_blocknr, a_n_blocknrs[MAX_AMOUNT_NEEDED] = { 0, }; | |
785 | int n_counter, n_number_of_freeblk, n_amount_needed, /* number of needed empty blocks */ | |
786 | n_retval = CARRY_ON; | |
787 | struct super_block *p_s_sb = p_s_tb->tb_sb; | |
788 | ||
789 | /* number_of_freeblk is the number of empty blocks which have been | |
790 | acquired for use by the balancing algorithm minus the number of | |
791 | empty blocks used in the previous levels of the analysis, | |
792 | number_of_freeblk = tb->cur_blknum can be non-zero if a schedule occurs | |
793 | after empty blocks are acquired, and the balancing analysis is | |
794 | then restarted, amount_needed is the number needed by this level | |
795 | (n_h) of the balancing analysis. | |
796 | ||
797 | Note that for systems with many processes writing, it would be | |
798 | more layout optimal to calculate the total number needed by all | |
799 | levels and then to run reiserfs_new_blocks to get all of them at once. */ | |
800 | ||
801 | /* Initiate number_of_freeblk to the amount acquired prior to the restart of | |
802 | the analysis or 0 if not restarted, then subtract the amount needed | |
803 | by all of the levels of the tree below n_h. */ | |
804 | /* blknum includes S[n_h], so we subtract 1 in this calculation */ | |
805 | for (n_counter = 0, n_number_of_freeblk = p_s_tb->cur_blknum; | |
806 | n_counter < n_h; n_counter++) | |
807 | n_number_of_freeblk -= | |
808 | (p_s_tb->blknum[n_counter]) ? (p_s_tb->blknum[n_counter] - | |
809 | 1) : 0; | |
810 | ||
811 | /* Allocate missing empty blocks. */ | |
812 | /* if p_s_Sh == 0 then we are getting a new root */ | |
813 | n_amount_needed = (p_s_Sh) ? (p_s_tb->blknum[n_h] - 1) : 1; | |
814 | /* Amount_needed = the amount that we need more than the amount that we have. */ | |
815 | if (n_amount_needed > n_number_of_freeblk) | |
816 | n_amount_needed -= n_number_of_freeblk; | |
817 | else /* If we have enough already then there is nothing to do. */ | |
818 | return CARRY_ON; | |
819 | ||
820 | /* No need to check quota - is not allocated for blocks used for formatted nodes */ | |
821 | if (reiserfs_new_form_blocknrs(p_s_tb, a_n_blocknrs, | |
822 | n_amount_needed) == NO_DISK_SPACE) | |
823 | return NO_DISK_SPACE; | |
824 | ||
825 | /* for each blocknumber we just got, get a buffer and stick it on FEB */ | |
826 | for (p_n_blocknr = a_n_blocknrs, n_counter = 0; | |
827 | n_counter < n_amount_needed; p_n_blocknr++, n_counter++) { | |
828 | ||
829 | RFALSE(!*p_n_blocknr, | |
830 | "PAP-8135: reiserfs_new_blocknrs failed when got new blocks"); | |
831 | ||
832 | p_s_new_bh = sb_getblk(p_s_sb, *p_n_blocknr); | |
833 | RFALSE(buffer_dirty(p_s_new_bh) || | |
834 | buffer_journaled(p_s_new_bh) || | |
835 | buffer_journal_dirty(p_s_new_bh), | |
836 | "PAP-8140: journlaled or dirty buffer %b for the new block", | |
837 | p_s_new_bh); | |
838 | ||
839 | /* Put empty buffers into the array. */ | |
840 | RFALSE(p_s_tb->FEB[p_s_tb->cur_blknum], | |
841 | "PAP-8141: busy slot for new buffer"); | |
842 | ||
843 | set_buffer_journal_new(p_s_new_bh); | |
844 | p_s_tb->FEB[p_s_tb->cur_blknum++] = p_s_new_bh; | |
845 | } | |
846 | ||
847 | if (n_retval == CARRY_ON && FILESYSTEM_CHANGED_TB(p_s_tb)) | |
848 | n_retval = REPEAT_SEARCH; | |
1da177e4 | 849 | |
bd4c625c LT |
850 | return n_retval; |
851 | } | |
1da177e4 LT |
852 | |
853 | /* Get free space of the left neighbor, which is stored in the parent | |
854 | * node of the left neighbor. */ | |
bd4c625c | 855 | static int get_lfree(struct tree_balance *tb, int h) |
1da177e4 | 856 | { |
bd4c625c LT |
857 | struct buffer_head *l, *f; |
858 | int order; | |
1da177e4 | 859 | |
9dce07f1 AV |
860 | if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL || |
861 | (l = tb->FL[h]) == NULL) | |
bd4c625c | 862 | return 0; |
1da177e4 | 863 | |
bd4c625c LT |
864 | if (f == l) |
865 | order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) - 1; | |
866 | else { | |
867 | order = B_NR_ITEMS(l); | |
868 | f = l; | |
869 | } | |
1da177e4 | 870 | |
bd4c625c | 871 | return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order))); |
1da177e4 LT |
872 | } |
873 | ||
1da177e4 LT |
874 | /* Get free space of the right neighbor, |
875 | * which is stored in the parent node of the right neighbor. | |
876 | */ | |
bd4c625c | 877 | static int get_rfree(struct tree_balance *tb, int h) |
1da177e4 | 878 | { |
bd4c625c LT |
879 | struct buffer_head *r, *f; |
880 | int order; | |
1da177e4 | 881 | |
9dce07f1 AV |
882 | if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL || |
883 | (r = tb->FR[h]) == NULL) | |
bd4c625c | 884 | return 0; |
1da177e4 | 885 | |
bd4c625c LT |
886 | if (f == r) |
887 | order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) + 1; | |
888 | else { | |
889 | order = 0; | |
890 | f = r; | |
891 | } | |
1da177e4 | 892 | |
bd4c625c | 893 | return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order))); |
1da177e4 LT |
894 | |
895 | } | |
896 | ||
1da177e4 | 897 | /* Check whether left neighbor is in memory. */ |
bd4c625c LT |
898 | static int is_left_neighbor_in_cache(struct tree_balance *p_s_tb, int n_h) |
899 | { | |
900 | struct buffer_head *p_s_father, *left; | |
901 | struct super_block *p_s_sb = p_s_tb->tb_sb; | |
902 | b_blocknr_t n_left_neighbor_blocknr; | |
903 | int n_left_neighbor_position; | |
904 | ||
905 | if (!p_s_tb->FL[n_h]) /* Father of the left neighbor does not exist. */ | |
906 | return 0; | |
907 | ||
908 | /* Calculate father of the node to be balanced. */ | |
909 | p_s_father = PATH_H_PBUFFER(p_s_tb->tb_path, n_h + 1); | |
910 | ||
911 | RFALSE(!p_s_father || | |
912 | !B_IS_IN_TREE(p_s_father) || | |
913 | !B_IS_IN_TREE(p_s_tb->FL[n_h]) || | |
914 | !buffer_uptodate(p_s_father) || | |
915 | !buffer_uptodate(p_s_tb->FL[n_h]), | |
916 | "vs-8165: F[h] (%b) or FL[h] (%b) is invalid", | |
917 | p_s_father, p_s_tb->FL[n_h]); | |
918 | ||
919 | /* Get position of the pointer to the left neighbor into the left father. */ | |
920 | n_left_neighbor_position = (p_s_father == p_s_tb->FL[n_h]) ? | |
921 | p_s_tb->lkey[n_h] : B_NR_ITEMS(p_s_tb->FL[n_h]); | |
922 | /* Get left neighbor block number. */ | |
923 | n_left_neighbor_blocknr = | |
924 | B_N_CHILD_NUM(p_s_tb->FL[n_h], n_left_neighbor_position); | |
925 | /* Look for the left neighbor in the cache. */ | |
926 | if ((left = sb_find_get_block(p_s_sb, n_left_neighbor_blocknr))) { | |
927 | ||
928 | RFALSE(buffer_uptodate(left) && !B_IS_IN_TREE(left), | |
929 | "vs-8170: left neighbor (%b %z) is not in the tree", | |
930 | left, left); | |
931 | put_bh(left); | |
932 | return 1; | |
933 | } | |
1da177e4 | 934 | |
bd4c625c LT |
935 | return 0; |
936 | } | |
1da177e4 LT |
937 | |
938 | #define LEFT_PARENTS 'l' | |
939 | #define RIGHT_PARENTS 'r' | |
940 | ||
bd4c625c | 941 | static void decrement_key(struct cpu_key *p_s_key) |
1da177e4 | 942 | { |
bd4c625c LT |
943 | // call item specific function for this key |
944 | item_ops[cpu_key_k_type(p_s_key)]->decrement_key(p_s_key); | |
1da177e4 LT |
945 | } |
946 | ||
1da177e4 LT |
947 | /* Calculate far left/right parent of the left/right neighbor of the current node, that |
948 | * is calculate the left/right (FL[h]/FR[h]) neighbor of the parent F[h]. | |
949 | * Calculate left/right common parent of the current node and L[h]/R[h]. | |
950 | * Calculate left/right delimiting key position. | |
951 | * Returns: PATH_INCORRECT - path in the tree is not correct; | |
952 | SCHEDULE_OCCURRED - schedule occurred while the function worked; | |
953 | * CARRY_ON - schedule didn't occur while the function worked; | |
954 | */ | |
bd4c625c LT |
955 | static int get_far_parent(struct tree_balance *p_s_tb, |
956 | int n_h, | |
957 | struct buffer_head **pp_s_father, | |
958 | struct buffer_head **pp_s_com_father, char c_lr_par) | |
1da177e4 | 959 | { |
bd4c625c LT |
960 | struct buffer_head *p_s_parent; |
961 | INITIALIZE_PATH(s_path_to_neighbor_father); | |
fec6d055 | 962 | struct treepath *p_s_path = p_s_tb->tb_path; |
bd4c625c LT |
963 | struct cpu_key s_lr_father_key; |
964 | int n_counter, | |
965 | n_position = INT_MAX, | |
966 | n_first_last_position = 0, | |
967 | n_path_offset = PATH_H_PATH_OFFSET(p_s_path, n_h); | |
968 | ||
969 | /* Starting from F[n_h] go upwards in the tree, and look for the common | |
970 | ancestor of F[n_h], and its neighbor l/r, that should be obtained. */ | |
971 | ||
972 | n_counter = n_path_offset; | |
973 | ||
974 | RFALSE(n_counter < FIRST_PATH_ELEMENT_OFFSET, | |
975 | "PAP-8180: invalid path length"); | |
976 | ||
977 | for (; n_counter > FIRST_PATH_ELEMENT_OFFSET; n_counter--) { | |
978 | /* Check whether parent of the current buffer in the path is really parent in the tree. */ | |
979 | if (!B_IS_IN_TREE | |
980 | (p_s_parent = PATH_OFFSET_PBUFFER(p_s_path, n_counter - 1))) | |
981 | return REPEAT_SEARCH; | |
982 | /* Check whether position in the parent is correct. */ | |
983 | if ((n_position = | |
984 | PATH_OFFSET_POSITION(p_s_path, | |
985 | n_counter - 1)) > | |
986 | B_NR_ITEMS(p_s_parent)) | |
987 | return REPEAT_SEARCH; | |
988 | /* Check whether parent at the path really points to the child. */ | |
989 | if (B_N_CHILD_NUM(p_s_parent, n_position) != | |
990 | PATH_OFFSET_PBUFFER(p_s_path, n_counter)->b_blocknr) | |
991 | return REPEAT_SEARCH; | |
992 | /* Return delimiting key if position in the parent is not equal to first/last one. */ | |
993 | if (c_lr_par == RIGHT_PARENTS) | |
994 | n_first_last_position = B_NR_ITEMS(p_s_parent); | |
995 | if (n_position != n_first_last_position) { | |
996 | *pp_s_com_father = p_s_parent; | |
997 | get_bh(*pp_s_com_father); | |
998 | /*(*pp_s_com_father = p_s_parent)->b_count++; */ | |
999 | break; | |
1000 | } | |
1da177e4 | 1001 | } |
bd4c625c LT |
1002 | |
1003 | /* if we are in the root of the tree, then there is no common father */ | |
1004 | if (n_counter == FIRST_PATH_ELEMENT_OFFSET) { | |
1005 | /* Check whether first buffer in the path is the root of the tree. */ | |
1006 | if (PATH_OFFSET_PBUFFER | |
1007 | (p_s_tb->tb_path, | |
1008 | FIRST_PATH_ELEMENT_OFFSET)->b_blocknr == | |
1009 | SB_ROOT_BLOCK(p_s_tb->tb_sb)) { | |
1010 | *pp_s_father = *pp_s_com_father = NULL; | |
1011 | return CARRY_ON; | |
1012 | } | |
1013 | return REPEAT_SEARCH; | |
1da177e4 | 1014 | } |
1da177e4 | 1015 | |
bd4c625c LT |
1016 | RFALSE(B_LEVEL(*pp_s_com_father) <= DISK_LEAF_NODE_LEVEL, |
1017 | "PAP-8185: (%b %z) level too small", | |
1018 | *pp_s_com_father, *pp_s_com_father); | |
1da177e4 | 1019 | |
bd4c625c | 1020 | /* Check whether the common parent is locked. */ |
1da177e4 | 1021 | |
bd4c625c LT |
1022 | if (buffer_locked(*pp_s_com_father)) { |
1023 | __wait_on_buffer(*pp_s_com_father); | |
1024 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) { | |
1025 | decrement_bcount(*pp_s_com_father); | |
1026 | return REPEAT_SEARCH; | |
1027 | } | |
1da177e4 | 1028 | } |
1da177e4 | 1029 | |
bd4c625c LT |
1030 | /* So, we got common parent of the current node and its left/right neighbor. |
1031 | Now we are geting the parent of the left/right neighbor. */ | |
1da177e4 | 1032 | |
bd4c625c LT |
1033 | /* Form key to get parent of the left/right neighbor. */ |
1034 | le_key2cpu_key(&s_lr_father_key, | |
1035 | B_N_PDELIM_KEY(*pp_s_com_father, | |
1036 | (c_lr_par == | |
1037 | LEFT_PARENTS) ? (p_s_tb->lkey[n_h - 1] = | |
1038 | n_position - | |
1039 | 1) : (p_s_tb->rkey[n_h - | |
1040 | 1] = | |
1041 | n_position))); | |
1da177e4 | 1042 | |
bd4c625c LT |
1043 | if (c_lr_par == LEFT_PARENTS) |
1044 | decrement_key(&s_lr_father_key); | |
1da177e4 | 1045 | |
bd4c625c LT |
1046 | if (search_by_key |
1047 | (p_s_tb->tb_sb, &s_lr_father_key, &s_path_to_neighbor_father, | |
1048 | n_h + 1) == IO_ERROR) | |
1049 | // path is released | |
1050 | return IO_ERROR; | |
1da177e4 | 1051 | |
bd4c625c LT |
1052 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) { |
1053 | decrement_counters_in_path(&s_path_to_neighbor_father); | |
1054 | decrement_bcount(*pp_s_com_father); | |
1055 | return REPEAT_SEARCH; | |
1056 | } | |
1da177e4 | 1057 | |
bd4c625c | 1058 | *pp_s_father = PATH_PLAST_BUFFER(&s_path_to_neighbor_father); |
1da177e4 | 1059 | |
bd4c625c LT |
1060 | RFALSE(B_LEVEL(*pp_s_father) != n_h + 1, |
1061 | "PAP-8190: (%b %z) level too small", *pp_s_father, *pp_s_father); | |
1062 | RFALSE(s_path_to_neighbor_father.path_length < | |
1063 | FIRST_PATH_ELEMENT_OFFSET, "PAP-8192: path length is too small"); | |
1da177e4 | 1064 | |
bd4c625c LT |
1065 | s_path_to_neighbor_father.path_length--; |
1066 | decrement_counters_in_path(&s_path_to_neighbor_father); | |
1067 | return CARRY_ON; | |
1da177e4 LT |
1068 | } |
1069 | ||
1da177e4 LT |
1070 | /* Get parents of neighbors of node in the path(S[n_path_offset]) and common parents of |
1071 | * S[n_path_offset] and L[n_path_offset]/R[n_path_offset]: F[n_path_offset], FL[n_path_offset], | |
1072 | * FR[n_path_offset], CFL[n_path_offset], CFR[n_path_offset]. | |
1073 | * Calculate numbers of left and right delimiting keys position: lkey[n_path_offset], rkey[n_path_offset]. | |
1074 | * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; | |
1075 | * CARRY_ON - schedule didn't occur while the function worked; | |
1076 | */ | |
bd4c625c | 1077 | static int get_parents(struct tree_balance *p_s_tb, int n_h) |
1da177e4 | 1078 | { |
fec6d055 | 1079 | struct treepath *p_s_path = p_s_tb->tb_path; |
bd4c625c LT |
1080 | int n_position, |
1081 | n_ret_value, | |
1082 | n_path_offset = PATH_H_PATH_OFFSET(p_s_tb->tb_path, n_h); | |
1083 | struct buffer_head *p_s_curf, *p_s_curcf; | |
1084 | ||
1085 | /* Current node is the root of the tree or will be root of the tree */ | |
1086 | if (n_path_offset <= FIRST_PATH_ELEMENT_OFFSET) { | |
1087 | /* The root can not have parents. | |
1088 | Release nodes which previously were obtained as parents of the current node neighbors. */ | |
1089 | decrement_bcount(p_s_tb->FL[n_h]); | |
1090 | decrement_bcount(p_s_tb->CFL[n_h]); | |
1091 | decrement_bcount(p_s_tb->FR[n_h]); | |
1092 | decrement_bcount(p_s_tb->CFR[n_h]); | |
1093 | p_s_tb->FL[n_h] = p_s_tb->CFL[n_h] = p_s_tb->FR[n_h] = | |
1094 | p_s_tb->CFR[n_h] = NULL; | |
1095 | return CARRY_ON; | |
1096 | } | |
1097 | ||
1098 | /* Get parent FL[n_path_offset] of L[n_path_offset]. */ | |
1099 | if ((n_position = PATH_OFFSET_POSITION(p_s_path, n_path_offset - 1))) { | |
1100 | /* Current node is not the first child of its parent. */ | |
1101 | /*(p_s_curf = p_s_curcf = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1))->b_count += 2; */ | |
1102 | p_s_curf = p_s_curcf = | |
1103 | PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1); | |
1104 | get_bh(p_s_curf); | |
1105 | get_bh(p_s_curf); | |
1106 | p_s_tb->lkey[n_h] = n_position - 1; | |
1107 | } else { | |
1108 | /* Calculate current parent of L[n_path_offset], which is the left neighbor of the current node. | |
1109 | Calculate current common parent of L[n_path_offset] and the current node. Note that | |
1110 | CFL[n_path_offset] not equal FL[n_path_offset] and CFL[n_path_offset] not equal F[n_path_offset]. | |
1111 | Calculate lkey[n_path_offset]. */ | |
1112 | if ((n_ret_value = get_far_parent(p_s_tb, n_h + 1, &p_s_curf, | |
1113 | &p_s_curcf, | |
1114 | LEFT_PARENTS)) != CARRY_ON) | |
1115 | return n_ret_value; | |
1116 | } | |
1117 | ||
1da177e4 | 1118 | decrement_bcount(p_s_tb->FL[n_h]); |
bd4c625c | 1119 | p_s_tb->FL[n_h] = p_s_curf; /* New initialization of FL[n_h]. */ |
1da177e4 | 1120 | decrement_bcount(p_s_tb->CFL[n_h]); |
bd4c625c LT |
1121 | p_s_tb->CFL[n_h] = p_s_curcf; /* New initialization of CFL[n_h]. */ |
1122 | ||
1123 | RFALSE((p_s_curf && !B_IS_IN_TREE(p_s_curf)) || | |
1124 | (p_s_curcf && !B_IS_IN_TREE(p_s_curcf)), | |
1125 | "PAP-8195: FL (%b) or CFL (%b) is invalid", p_s_curf, p_s_curcf); | |
1da177e4 LT |
1126 | |
1127 | /* Get parent FR[n_h] of R[n_h]. */ | |
1128 | ||
1129 | /* Current node is the last child of F[n_h]. FR[n_h] != F[n_h]. */ | |
bd4c625c | 1130 | if (n_position == B_NR_ITEMS(PATH_H_PBUFFER(p_s_path, n_h + 1))) { |
1da177e4 LT |
1131 | /* Calculate current parent of R[n_h], which is the right neighbor of F[n_h]. |
1132 | Calculate current common parent of R[n_h] and current node. Note that CFR[n_h] | |
1133 | not equal FR[n_path_offset] and CFR[n_h] not equal F[n_h]. */ | |
bd4c625c LT |
1134 | if ((n_ret_value = |
1135 | get_far_parent(p_s_tb, n_h + 1, &p_s_curf, &p_s_curcf, | |
1136 | RIGHT_PARENTS)) != CARRY_ON) | |
1137 | return n_ret_value; | |
1138 | } else { | |
1da177e4 | 1139 | /* Current node is not the last child of its parent F[n_h]. */ |
bd4c625c LT |
1140 | /*(p_s_curf = p_s_curcf = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1))->b_count += 2; */ |
1141 | p_s_curf = p_s_curcf = | |
1142 | PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1); | |
1143 | get_bh(p_s_curf); | |
1144 | get_bh(p_s_curf); | |
1145 | p_s_tb->rkey[n_h] = n_position; | |
1146 | } | |
1da177e4 | 1147 | |
bd4c625c LT |
1148 | decrement_bcount(p_s_tb->FR[n_h]); |
1149 | p_s_tb->FR[n_h] = p_s_curf; /* New initialization of FR[n_path_offset]. */ | |
1150 | ||
1151 | decrement_bcount(p_s_tb->CFR[n_h]); | |
1152 | p_s_tb->CFR[n_h] = p_s_curcf; /* New initialization of CFR[n_path_offset]. */ | |
1153 | ||
1154 | RFALSE((p_s_curf && !B_IS_IN_TREE(p_s_curf)) || | |
1155 | (p_s_curcf && !B_IS_IN_TREE(p_s_curcf)), | |
1156 | "PAP-8205: FR (%b) or CFR (%b) is invalid", p_s_curf, p_s_curcf); | |
1157 | ||
1158 | return CARRY_ON; | |
1159 | } | |
1da177e4 LT |
1160 | |
1161 | /* it is possible to remove node as result of shiftings to | |
1162 | neighbors even when we insert or paste item. */ | |
bd4c625c LT |
1163 | static inline int can_node_be_removed(int mode, int lfree, int sfree, int rfree, |
1164 | struct tree_balance *tb, int h) | |
1da177e4 | 1165 | { |
bd4c625c LT |
1166 | struct buffer_head *Sh = PATH_H_PBUFFER(tb->tb_path, h); |
1167 | int levbytes = tb->insert_size[h]; | |
1168 | struct item_head *ih; | |
1169 | struct reiserfs_key *r_key = NULL; | |
1170 | ||
1171 | ih = B_N_PITEM_HEAD(Sh, 0); | |
1172 | if (tb->CFR[h]) | |
1173 | r_key = B_N_PDELIM_KEY(tb->CFR[h], tb->rkey[h]); | |
1174 | ||
1175 | if (lfree + rfree + sfree < MAX_CHILD_SIZE(Sh) + levbytes | |
1176 | /* shifting may merge items which might save space */ | |
1177 | - | |
1178 | ((!h | |
1179 | && op_is_left_mergeable(&(ih->ih_key), Sh->b_size)) ? IH_SIZE : 0) | |
1180 | - | |
1181 | ((!h && r_key | |
1182 | && op_is_left_mergeable(r_key, Sh->b_size)) ? IH_SIZE : 0) | |
1183 | + ((h) ? KEY_SIZE : 0)) { | |
1184 | /* node can not be removed */ | |
1185 | if (sfree >= levbytes) { /* new item fits into node S[h] without any shifting */ | |
1186 | if (!h) | |
1187 | tb->s0num = | |
1188 | B_NR_ITEMS(Sh) + | |
1189 | ((mode == M_INSERT) ? 1 : 0); | |
1190 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1191 | return NO_BALANCING_NEEDED; | |
1192 | } | |
1da177e4 | 1193 | } |
bd4c625c LT |
1194 | PROC_INFO_INC(tb->tb_sb, can_node_be_removed[h]); |
1195 | return !NO_BALANCING_NEEDED; | |
1da177e4 LT |
1196 | } |
1197 | ||
1da177e4 LT |
1198 | /* Check whether current node S[h] is balanced when increasing its size by |
1199 | * Inserting or Pasting. | |
1200 | * Calculate parameters for balancing for current level h. | |
1201 | * Parameters: | |
1202 | * tb tree_balance structure; | |
1203 | * h current level of the node; | |
1204 | * inum item number in S[h]; | |
1205 | * mode i - insert, p - paste; | |
1206 | * Returns: 1 - schedule occurred; | |
1207 | * 0 - balancing for higher levels needed; | |
1208 | * -1 - no balancing for higher levels needed; | |
1209 | * -2 - no disk space. | |
1210 | */ | |
1211 | /* ip means Inserting or Pasting */ | |
bd4c625c | 1212 | static int ip_check_balance(struct tree_balance *tb, int h) |
1da177e4 | 1213 | { |
bd4c625c LT |
1214 | struct virtual_node *vn = tb->tb_vn; |
1215 | int levbytes, /* Number of bytes that must be inserted into (value | |
1216 | is negative if bytes are deleted) buffer which | |
1217 | contains node being balanced. The mnemonic is | |
1218 | that the attempted change in node space used level | |
1219 | is levbytes bytes. */ | |
1220 | n_ret_value; | |
1221 | ||
1222 | int lfree, sfree, rfree /* free space in L, S and R */ ; | |
1223 | ||
1224 | /* nver is short for number of vertixes, and lnver is the number if | |
1225 | we shift to the left, rnver is the number if we shift to the | |
1226 | right, and lrnver is the number if we shift in both directions. | |
1227 | The goal is to minimize first the number of vertixes, and second, | |
1228 | the number of vertixes whose contents are changed by shifting, | |
1229 | and third the number of uncached vertixes whose contents are | |
1230 | changed by shifting and must be read from disk. */ | |
1231 | int nver, lnver, rnver, lrnver; | |
1232 | ||
1233 | /* used at leaf level only, S0 = S[0] is the node being balanced, | |
1234 | sInum [ I = 0,1,2 ] is the number of items that will | |
1235 | remain in node SI after balancing. S1 and S2 are new | |
1236 | nodes that might be created. */ | |
1237 | ||
1238 | /* we perform 8 calls to get_num_ver(). For each call we calculate five parameters. | |
1239 | where 4th parameter is s1bytes and 5th - s2bytes | |
1240 | */ | |
1241 | short snum012[40] = { 0, }; /* s0num, s1num, s2num for 8 cases | |
1242 | 0,1 - do not shift and do not shift but bottle | |
1243 | 2 - shift only whole item to left | |
1244 | 3 - shift to left and bottle as much as possible | |
1245 | 4,5 - shift to right (whole items and as much as possible | |
1246 | 6,7 - shift to both directions (whole items and as much as possible) | |
1247 | */ | |
1248 | ||
1249 | /* Sh is the node whose balance is currently being checked */ | |
1250 | struct buffer_head *Sh; | |
1251 | ||
1252 | Sh = PATH_H_PBUFFER(tb->tb_path, h); | |
1253 | levbytes = tb->insert_size[h]; | |
1254 | ||
1255 | /* Calculate balance parameters for creating new root. */ | |
1256 | if (!Sh) { | |
1257 | if (!h) | |
c3a9c210 JM |
1258 | reiserfs_panic(tb->tb_sb, "vs-8210", |
1259 | "S[0] can not be 0"); | |
bd4c625c LT |
1260 | switch (n_ret_value = get_empty_nodes(tb, h)) { |
1261 | case CARRY_ON: | |
1262 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1263 | return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ | |
1264 | ||
1265 | case NO_DISK_SPACE: | |
1266 | case REPEAT_SEARCH: | |
1267 | return n_ret_value; | |
1268 | default: | |
c3a9c210 JM |
1269 | reiserfs_panic(tb->tb_sb, "vs-8215", "incorrect " |
1270 | "return value of get_empty_nodes"); | |
bd4c625c | 1271 | } |
1da177e4 | 1272 | } |
1da177e4 | 1273 | |
bd4c625c LT |
1274 | if ((n_ret_value = get_parents(tb, h)) != CARRY_ON) /* get parents of S[h] neighbors. */ |
1275 | return n_ret_value; | |
1da177e4 | 1276 | |
bd4c625c LT |
1277 | sfree = B_FREE_SPACE(Sh); |
1278 | ||
1279 | /* get free space of neighbors */ | |
1280 | rfree = get_rfree(tb, h); | |
1281 | lfree = get_lfree(tb, h); | |
1282 | ||
1283 | if (can_node_be_removed(vn->vn_mode, lfree, sfree, rfree, tb, h) == | |
1284 | NO_BALANCING_NEEDED) | |
1285 | /* and new item fits into node S[h] without any shifting */ | |
1286 | return NO_BALANCING_NEEDED; | |
1da177e4 | 1287 | |
bd4c625c | 1288 | create_virtual_node(tb, h); |
1da177e4 | 1289 | |
bd4c625c LT |
1290 | /* |
1291 | determine maximal number of items we can shift to the left neighbor (in tb structure) | |
1292 | and the maximal number of bytes that can flow to the left neighbor | |
1293 | from the left most liquid item that cannot be shifted from S[0] entirely (returned value) | |
1da177e4 | 1294 | */ |
bd4c625c | 1295 | check_left(tb, h, lfree); |
1da177e4 | 1296 | |
bd4c625c LT |
1297 | /* |
1298 | determine maximal number of items we can shift to the right neighbor (in tb structure) | |
1299 | and the maximal number of bytes that can flow to the right neighbor | |
1300 | from the right most liquid item that cannot be shifted from S[0] entirely (returned value) | |
1301 | */ | |
1302 | check_right(tb, h, rfree); | |
1303 | ||
1304 | /* all contents of internal node S[h] can be moved into its | |
1305 | neighbors, S[h] will be removed after balancing */ | |
1306 | if (h && (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1)) { | |
1307 | int to_r; | |
1308 | ||
1309 | /* Since we are working on internal nodes, and our internal | |
1310 | nodes have fixed size entries, then we can balance by the | |
1311 | number of items rather than the space they consume. In this | |
1312 | routine we set the left node equal to the right node, | |
1313 | allowing a difference of less than or equal to 1 child | |
1314 | pointer. */ | |
1315 | to_r = | |
1316 | ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] + | |
1317 | vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - | |
1318 | tb->rnum[h]); | |
1319 | set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL, | |
1320 | -1, -1); | |
1321 | return CARRY_ON; | |
1322 | } | |
1323 | ||
1324 | /* this checks balance condition, that any two neighboring nodes can not fit in one node */ | |
1325 | RFALSE(h && | |
1326 | (tb->lnum[h] >= vn->vn_nr_item + 1 || | |
1327 | tb->rnum[h] >= vn->vn_nr_item + 1), | |
1328 | "vs-8220: tree is not balanced on internal level"); | |
1329 | RFALSE(!h && ((tb->lnum[h] >= vn->vn_nr_item && (tb->lbytes == -1)) || | |
1330 | (tb->rnum[h] >= vn->vn_nr_item && (tb->rbytes == -1))), | |
1331 | "vs-8225: tree is not balanced on leaf level"); | |
1332 | ||
1333 | /* all contents of S[0] can be moved into its neighbors | |
1334 | S[0] will be removed after balancing. */ | |
1335 | if (!h && is_leaf_removable(tb)) | |
1336 | return CARRY_ON; | |
1337 | ||
1338 | /* why do we perform this check here rather than earlier?? | |
1339 | Answer: we can win 1 node in some cases above. Moreover we | |
1340 | checked it above, when we checked, that S[0] is not removable | |
1341 | in principle */ | |
1342 | if (sfree >= levbytes) { /* new item fits into node S[h] without any shifting */ | |
1343 | if (!h) | |
1344 | tb->s0num = vn->vn_nr_item; | |
1345 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1346 | return NO_BALANCING_NEEDED; | |
1347 | } | |
1348 | ||
1349 | { | |
1350 | int lpar, rpar, nset, lset, rset, lrset; | |
1351 | /* | |
1352 | * regular overflowing of the node | |
1353 | */ | |
1354 | ||
1355 | /* get_num_ver works in 2 modes (FLOW & NO_FLOW) | |
1356 | lpar, rpar - number of items we can shift to left/right neighbor (including splitting item) | |
1357 | nset, lset, rset, lrset - shows, whether flowing items give better packing | |
1358 | */ | |
1da177e4 | 1359 | #define FLOW 1 |
bd4c625c | 1360 | #define NO_FLOW 0 /* do not any splitting */ |
1da177e4 | 1361 | |
bd4c625c | 1362 | /* we choose one the following */ |
1da177e4 LT |
1363 | #define NOTHING_SHIFT_NO_FLOW 0 |
1364 | #define NOTHING_SHIFT_FLOW 5 | |
1365 | #define LEFT_SHIFT_NO_FLOW 10 | |
1366 | #define LEFT_SHIFT_FLOW 15 | |
1367 | #define RIGHT_SHIFT_NO_FLOW 20 | |
1368 | #define RIGHT_SHIFT_FLOW 25 | |
1369 | #define LR_SHIFT_NO_FLOW 30 | |
1370 | #define LR_SHIFT_FLOW 35 | |
1371 | ||
bd4c625c LT |
1372 | lpar = tb->lnum[h]; |
1373 | rpar = tb->rnum[h]; | |
1374 | ||
1375 | /* calculate number of blocks S[h] must be split into when | |
1376 | nothing is shifted to the neighbors, | |
1377 | as well as number of items in each part of the split node (s012 numbers), | |
1378 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any */ | |
1379 | nset = NOTHING_SHIFT_NO_FLOW; | |
1380 | nver = get_num_ver(vn->vn_mode, tb, h, | |
1381 | 0, -1, h ? vn->vn_nr_item : 0, -1, | |
1382 | snum012, NO_FLOW); | |
1383 | ||
1384 | if (!h) { | |
1385 | int nver1; | |
1386 | ||
1387 | /* note, that in this case we try to bottle between S[0] and S1 (S1 - the first new node) */ | |
1388 | nver1 = get_num_ver(vn->vn_mode, tb, h, | |
1389 | 0, -1, 0, -1, | |
1390 | snum012 + NOTHING_SHIFT_FLOW, FLOW); | |
1391 | if (nver > nver1) | |
1392 | nset = NOTHING_SHIFT_FLOW, nver = nver1; | |
1393 | } | |
1da177e4 | 1394 | |
bd4c625c LT |
1395 | /* calculate number of blocks S[h] must be split into when |
1396 | l_shift_num first items and l_shift_bytes of the right most | |
1397 | liquid item to be shifted are shifted to the left neighbor, | |
1398 | as well as number of items in each part of the splitted node (s012 numbers), | |
1399 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any | |
1400 | */ | |
1401 | lset = LEFT_SHIFT_NO_FLOW; | |
1402 | lnver = get_num_ver(vn->vn_mode, tb, h, | |
1403 | lpar - ((h || tb->lbytes == -1) ? 0 : 1), | |
1404 | -1, h ? vn->vn_nr_item : 0, -1, | |
1405 | snum012 + LEFT_SHIFT_NO_FLOW, NO_FLOW); | |
1406 | if (!h) { | |
1407 | int lnver1; | |
1408 | ||
1409 | lnver1 = get_num_ver(vn->vn_mode, tb, h, | |
1410 | lpar - | |
1411 | ((tb->lbytes != -1) ? 1 : 0), | |
1412 | tb->lbytes, 0, -1, | |
1413 | snum012 + LEFT_SHIFT_FLOW, FLOW); | |
1414 | if (lnver > lnver1) | |
1415 | lset = LEFT_SHIFT_FLOW, lnver = lnver1; | |
1416 | } | |
1da177e4 | 1417 | |
bd4c625c LT |
1418 | /* calculate number of blocks S[h] must be split into when |
1419 | r_shift_num first items and r_shift_bytes of the left most | |
1420 | liquid item to be shifted are shifted to the right neighbor, | |
1421 | as well as number of items in each part of the splitted node (s012 numbers), | |
1422 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any | |
1423 | */ | |
1424 | rset = RIGHT_SHIFT_NO_FLOW; | |
1425 | rnver = get_num_ver(vn->vn_mode, tb, h, | |
1426 | 0, -1, | |
1427 | h ? (vn->vn_nr_item - rpar) : (rpar - | |
1428 | ((tb-> | |
1429 | rbytes != | |
1430 | -1) ? 1 : | |
1431 | 0)), -1, | |
1432 | snum012 + RIGHT_SHIFT_NO_FLOW, NO_FLOW); | |
1433 | if (!h) { | |
1434 | int rnver1; | |
1435 | ||
1436 | rnver1 = get_num_ver(vn->vn_mode, tb, h, | |
1437 | 0, -1, | |
1438 | (rpar - | |
1439 | ((tb->rbytes != -1) ? 1 : 0)), | |
1440 | tb->rbytes, | |
1441 | snum012 + RIGHT_SHIFT_FLOW, FLOW); | |
1442 | ||
1443 | if (rnver > rnver1) | |
1444 | rset = RIGHT_SHIFT_FLOW, rnver = rnver1; | |
1445 | } | |
1da177e4 | 1446 | |
bd4c625c LT |
1447 | /* calculate number of blocks S[h] must be split into when |
1448 | items are shifted in both directions, | |
1449 | as well as number of items in each part of the splitted node (s012 numbers), | |
1450 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any | |
1451 | */ | |
1452 | lrset = LR_SHIFT_NO_FLOW; | |
1453 | lrnver = get_num_ver(vn->vn_mode, tb, h, | |
1454 | lpar - ((h || tb->lbytes == -1) ? 0 : 1), | |
1455 | -1, | |
1456 | h ? (vn->vn_nr_item - rpar) : (rpar - | |
1457 | ((tb-> | |
1458 | rbytes != | |
1459 | -1) ? 1 : | |
1460 | 0)), -1, | |
1461 | snum012 + LR_SHIFT_NO_FLOW, NO_FLOW); | |
1462 | if (!h) { | |
1463 | int lrnver1; | |
1464 | ||
1465 | lrnver1 = get_num_ver(vn->vn_mode, tb, h, | |
1466 | lpar - | |
1467 | ((tb->lbytes != -1) ? 1 : 0), | |
1468 | tb->lbytes, | |
1469 | (rpar - | |
1470 | ((tb->rbytes != -1) ? 1 : 0)), | |
1471 | tb->rbytes, | |
1472 | snum012 + LR_SHIFT_FLOW, FLOW); | |
1473 | if (lrnver > lrnver1) | |
1474 | lrset = LR_SHIFT_FLOW, lrnver = lrnver1; | |
1475 | } | |
1da177e4 | 1476 | |
bd4c625c LT |
1477 | /* Our general shifting strategy is: |
1478 | 1) to minimized number of new nodes; | |
1479 | 2) to minimized number of neighbors involved in shifting; | |
1480 | 3) to minimized number of disk reads; */ | |
1481 | ||
1482 | /* we can win TWO or ONE nodes by shifting in both directions */ | |
1483 | if (lrnver < lnver && lrnver < rnver) { | |
1484 | RFALSE(h && | |
1485 | (tb->lnum[h] != 1 || | |
1486 | tb->rnum[h] != 1 || | |
1487 | lrnver != 1 || rnver != 2 || lnver != 2 | |
1488 | || h != 1), "vs-8230: bad h"); | |
1489 | if (lrset == LR_SHIFT_FLOW) | |
1490 | set_parameters(tb, h, tb->lnum[h], tb->rnum[h], | |
1491 | lrnver, snum012 + lrset, | |
1492 | tb->lbytes, tb->rbytes); | |
1493 | else | |
1494 | set_parameters(tb, h, | |
1495 | tb->lnum[h] - | |
1496 | ((tb->lbytes == -1) ? 0 : 1), | |
1497 | tb->rnum[h] - | |
1498 | ((tb->rbytes == -1) ? 0 : 1), | |
1499 | lrnver, snum012 + lrset, -1, -1); | |
1500 | ||
1501 | return CARRY_ON; | |
1502 | } | |
1da177e4 | 1503 | |
bd4c625c LT |
1504 | /* if shifting doesn't lead to better packing then don't shift */ |
1505 | if (nver == lrnver) { | |
1506 | set_parameters(tb, h, 0, 0, nver, snum012 + nset, -1, | |
1507 | -1); | |
1508 | return CARRY_ON; | |
1509 | } | |
1da177e4 | 1510 | |
bd4c625c LT |
1511 | /* now we know that for better packing shifting in only one |
1512 | direction either to the left or to the right is required */ | |
1da177e4 | 1513 | |
bd4c625c LT |
1514 | /* if shifting to the left is better than shifting to the right */ |
1515 | if (lnver < rnver) { | |
1516 | SET_PAR_SHIFT_LEFT; | |
1517 | return CARRY_ON; | |
1518 | } | |
1da177e4 | 1519 | |
bd4c625c LT |
1520 | /* if shifting to the right is better than shifting to the left */ |
1521 | if (lnver > rnver) { | |
1522 | SET_PAR_SHIFT_RIGHT; | |
1523 | return CARRY_ON; | |
1524 | } | |
1da177e4 | 1525 | |
bd4c625c LT |
1526 | /* now shifting in either direction gives the same number |
1527 | of nodes and we can make use of the cached neighbors */ | |
1528 | if (is_left_neighbor_in_cache(tb, h)) { | |
1529 | SET_PAR_SHIFT_LEFT; | |
1530 | return CARRY_ON; | |
1531 | } | |
1da177e4 | 1532 | |
bd4c625c LT |
1533 | /* shift to the right independently on whether the right neighbor in cache or not */ |
1534 | SET_PAR_SHIFT_RIGHT; | |
1535 | return CARRY_ON; | |
1da177e4 | 1536 | } |
1da177e4 LT |
1537 | } |
1538 | ||
1da177e4 LT |
1539 | /* Check whether current node S[h] is balanced when Decreasing its size by |
1540 | * Deleting or Cutting for INTERNAL node of S+tree. | |
1541 | * Calculate parameters for balancing for current level h. | |
1542 | * Parameters: | |
1543 | * tb tree_balance structure; | |
1544 | * h current level of the node; | |
1545 | * inum item number in S[h]; | |
1546 | * mode i - insert, p - paste; | |
1547 | * Returns: 1 - schedule occurred; | |
1548 | * 0 - balancing for higher levels needed; | |
1549 | * -1 - no balancing for higher levels needed; | |
1550 | * -2 - no disk space. | |
1551 | * | |
1552 | * Note: Items of internal nodes have fixed size, so the balance condition for | |
1553 | * the internal part of S+tree is as for the B-trees. | |
1554 | */ | |
bd4c625c | 1555 | static int dc_check_balance_internal(struct tree_balance *tb, int h) |
1da177e4 | 1556 | { |
bd4c625c | 1557 | struct virtual_node *vn = tb->tb_vn; |
1da177e4 | 1558 | |
bd4c625c LT |
1559 | /* Sh is the node whose balance is currently being checked, |
1560 | and Fh is its father. */ | |
1561 | struct buffer_head *Sh, *Fh; | |
1562 | int maxsize, n_ret_value; | |
1563 | int lfree, rfree /* free space in L and R */ ; | |
1da177e4 | 1564 | |
bd4c625c LT |
1565 | Sh = PATH_H_PBUFFER(tb->tb_path, h); |
1566 | Fh = PATH_H_PPARENT(tb->tb_path, h); | |
1da177e4 | 1567 | |
bd4c625c | 1568 | maxsize = MAX_CHILD_SIZE(Sh); |
1da177e4 LT |
1569 | |
1570 | /* using tb->insert_size[h], which is negative in this case, create_virtual_node calculates: */ | |
1571 | /* new_nr_item = number of items node would have if operation is */ | |
1572 | /* performed without balancing (new_nr_item); */ | |
bd4c625c | 1573 | create_virtual_node(tb, h); |
1da177e4 | 1574 | |
bd4c625c LT |
1575 | if (!Fh) { /* S[h] is the root. */ |
1576 | if (vn->vn_nr_item > 0) { | |
1577 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1578 | return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ | |
1579 | } | |
1580 | /* new_nr_item == 0. | |
1581 | * Current root will be deleted resulting in | |
1582 | * decrementing the tree height. */ | |
1583 | set_parameters(tb, h, 0, 0, 0, NULL, -1, -1); | |
1584 | return CARRY_ON; | |
1585 | } | |
1586 | ||
1587 | if ((n_ret_value = get_parents(tb, h)) != CARRY_ON) | |
1588 | return n_ret_value; | |
1589 | ||
1590 | /* get free space of neighbors */ | |
1591 | rfree = get_rfree(tb, h); | |
1592 | lfree = get_lfree(tb, h); | |
1593 | ||
1594 | /* determine maximal number of items we can fit into neighbors */ | |
1595 | check_left(tb, h, lfree); | |
1596 | check_right(tb, h, rfree); | |
1597 | ||
1598 | if (vn->vn_nr_item >= MIN_NR_KEY(Sh)) { /* Balance condition for the internal node is valid. | |
1599 | * In this case we balance only if it leads to better packing. */ | |
1600 | if (vn->vn_nr_item == MIN_NR_KEY(Sh)) { /* Here we join S[h] with one of its neighbors, | |
1601 | * which is impossible with greater values of new_nr_item. */ | |
1602 | if (tb->lnum[h] >= vn->vn_nr_item + 1) { | |
1603 | /* All contents of S[h] can be moved to L[h]. */ | |
1604 | int n; | |
1605 | int order_L; | |
1606 | ||
1607 | order_L = | |
1608 | ((n = | |
1609 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1610 | h)) == | |
1611 | 0) ? B_NR_ITEMS(tb->FL[h]) : n - 1; | |
1612 | n = dc_size(B_N_CHILD(tb->FL[h], order_L)) / | |
1613 | (DC_SIZE + KEY_SIZE); | |
1614 | set_parameters(tb, h, -n - 1, 0, 0, NULL, -1, | |
1615 | -1); | |
1616 | return CARRY_ON; | |
1617 | } | |
1618 | ||
1619 | if (tb->rnum[h] >= vn->vn_nr_item + 1) { | |
1620 | /* All contents of S[h] can be moved to R[h]. */ | |
1621 | int n; | |
1622 | int order_R; | |
1623 | ||
1624 | order_R = | |
1625 | ((n = | |
1626 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1627 | h)) == | |
1628 | B_NR_ITEMS(Fh)) ? 0 : n + 1; | |
1629 | n = dc_size(B_N_CHILD(tb->FR[h], order_R)) / | |
1630 | (DC_SIZE + KEY_SIZE); | |
1631 | set_parameters(tb, h, 0, -n - 1, 0, NULL, -1, | |
1632 | -1); | |
1633 | return CARRY_ON; | |
1634 | } | |
1635 | } | |
1636 | ||
1637 | if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) { | |
1638 | /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */ | |
1639 | int to_r; | |
1640 | ||
1641 | to_r = | |
1642 | ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - | |
1643 | tb->rnum[h] + vn->vn_nr_item + 1) / 2 - | |
1644 | (MAX_NR_KEY(Sh) + 1 - tb->rnum[h]); | |
1645 | set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, | |
1646 | 0, NULL, -1, -1); | |
1647 | return CARRY_ON; | |
1648 | } | |
1649 | ||
1650 | /* Balancing does not lead to better packing. */ | |
1651 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1652 | return NO_BALANCING_NEEDED; | |
1da177e4 | 1653 | } |
bd4c625c LT |
1654 | |
1655 | /* Current node contain insufficient number of items. Balancing is required. */ | |
1656 | /* Check whether we can merge S[h] with left neighbor. */ | |
1657 | if (tb->lnum[h] >= vn->vn_nr_item + 1) | |
1658 | if (is_left_neighbor_in_cache(tb, h) | |
1659 | || tb->rnum[h] < vn->vn_nr_item + 1 || !tb->FR[h]) { | |
1660 | int n; | |
1661 | int order_L; | |
1662 | ||
1663 | order_L = | |
1664 | ((n = | |
1665 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1666 | h)) == | |
1667 | 0) ? B_NR_ITEMS(tb->FL[h]) : n - 1; | |
1668 | n = dc_size(B_N_CHILD(tb->FL[h], order_L)) / (DC_SIZE + | |
1669 | KEY_SIZE); | |
1670 | set_parameters(tb, h, -n - 1, 0, 0, NULL, -1, -1); | |
1671 | return CARRY_ON; | |
1672 | } | |
1673 | ||
1674 | /* Check whether we can merge S[h] with right neighbor. */ | |
1675 | if (tb->rnum[h] >= vn->vn_nr_item + 1) { | |
1676 | int n; | |
1677 | int order_R; | |
1678 | ||
1679 | order_R = | |
1680 | ((n = | |
1681 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1682 | h)) == B_NR_ITEMS(Fh)) ? 0 : (n + 1); | |
1683 | n = dc_size(B_N_CHILD(tb->FR[h], order_R)) / (DC_SIZE + | |
1684 | KEY_SIZE); | |
1685 | set_parameters(tb, h, 0, -n - 1, 0, NULL, -1, -1); | |
1686 | return CARRY_ON; | |
1da177e4 LT |
1687 | } |
1688 | ||
bd4c625c LT |
1689 | /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */ |
1690 | if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) { | |
1691 | int to_r; | |
1692 | ||
1693 | to_r = | |
1694 | ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] + | |
1695 | vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - | |
1696 | tb->rnum[h]); | |
1697 | set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL, | |
1698 | -1, -1); | |
1699 | return CARRY_ON; | |
1700 | } | |
1da177e4 | 1701 | |
bd4c625c LT |
1702 | /* For internal nodes try to borrow item from a neighbor */ |
1703 | RFALSE(!tb->FL[h] && !tb->FR[h], "vs-8235: trying to borrow for root"); | |
1704 | ||
1705 | /* Borrow one or two items from caching neighbor */ | |
1706 | if (is_left_neighbor_in_cache(tb, h) || !tb->FR[h]) { | |
1707 | int from_l; | |
1708 | ||
1709 | from_l = | |
1710 | (MAX_NR_KEY(Sh) + 1 - tb->lnum[h] + vn->vn_nr_item + | |
1711 | 1) / 2 - (vn->vn_nr_item + 1); | |
1712 | set_parameters(tb, h, -from_l, 0, 1, NULL, -1, -1); | |
1713 | return CARRY_ON; | |
1da177e4 LT |
1714 | } |
1715 | ||
bd4c625c LT |
1716 | set_parameters(tb, h, 0, |
1717 | -((MAX_NR_KEY(Sh) + 1 - tb->rnum[h] + vn->vn_nr_item + | |
1718 | 1) / 2 - (vn->vn_nr_item + 1)), 1, NULL, -1, -1); | |
1da177e4 | 1719 | return CARRY_ON; |
1da177e4 LT |
1720 | } |
1721 | ||
1da177e4 LT |
1722 | /* Check whether current node S[h] is balanced when Decreasing its size by |
1723 | * Deleting or Truncating for LEAF node of S+tree. | |
1724 | * Calculate parameters for balancing for current level h. | |
1725 | * Parameters: | |
1726 | * tb tree_balance structure; | |
1727 | * h current level of the node; | |
1728 | * inum item number in S[h]; | |
1729 | * mode i - insert, p - paste; | |
1730 | * Returns: 1 - schedule occurred; | |
1731 | * 0 - balancing for higher levels needed; | |
1732 | * -1 - no balancing for higher levels needed; | |
1733 | * -2 - no disk space. | |
1734 | */ | |
bd4c625c | 1735 | static int dc_check_balance_leaf(struct tree_balance *tb, int h) |
1da177e4 | 1736 | { |
bd4c625c LT |
1737 | struct virtual_node *vn = tb->tb_vn; |
1738 | ||
1739 | /* Number of bytes that must be deleted from | |
1740 | (value is negative if bytes are deleted) buffer which | |
1741 | contains node being balanced. The mnemonic is that the | |
1742 | attempted change in node space used level is levbytes bytes. */ | |
1743 | int levbytes; | |
1744 | /* the maximal item size */ | |
1745 | int maxsize, n_ret_value; | |
1746 | /* S0 is the node whose balance is currently being checked, | |
1747 | and F0 is its father. */ | |
1748 | struct buffer_head *S0, *F0; | |
1749 | int lfree, rfree /* free space in L and R */ ; | |
1750 | ||
1751 | S0 = PATH_H_PBUFFER(tb->tb_path, 0); | |
1752 | F0 = PATH_H_PPARENT(tb->tb_path, 0); | |
1da177e4 | 1753 | |
bd4c625c | 1754 | levbytes = tb->insert_size[h]; |
1da177e4 | 1755 | |
bd4c625c LT |
1756 | maxsize = MAX_CHILD_SIZE(S0); /* maximal possible size of an item */ |
1757 | ||
1758 | if (!F0) { /* S[0] is the root now. */ | |
1759 | ||
1760 | RFALSE(-levbytes >= maxsize - B_FREE_SPACE(S0), | |
1761 | "vs-8240: attempt to create empty buffer tree"); | |
1762 | ||
1763 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1764 | return NO_BALANCING_NEEDED; | |
1765 | } | |
1766 | ||
1767 | if ((n_ret_value = get_parents(tb, h)) != CARRY_ON) | |
1768 | return n_ret_value; | |
1769 | ||
1770 | /* get free space of neighbors */ | |
1771 | rfree = get_rfree(tb, h); | |
1772 | lfree = get_lfree(tb, h); | |
1773 | ||
1774 | create_virtual_node(tb, h); | |
1775 | ||
1776 | /* if 3 leaves can be merge to one, set parameters and return */ | |
1777 | if (are_leaves_removable(tb, lfree, rfree)) | |
1778 | return CARRY_ON; | |
1779 | ||
1780 | /* determine maximal number of items we can shift to the left/right neighbor | |
1781 | and the maximal number of bytes that can flow to the left/right neighbor | |
1782 | from the left/right most liquid item that cannot be shifted from S[0] entirely | |
1783 | */ | |
1784 | check_left(tb, h, lfree); | |
1785 | check_right(tb, h, rfree); | |
1786 | ||
1787 | /* check whether we can merge S with left neighbor. */ | |
1788 | if (tb->lnum[0] >= vn->vn_nr_item && tb->lbytes == -1) | |
1789 | if (is_left_neighbor_in_cache(tb, h) || ((tb->rnum[0] - ((tb->rbytes == -1) ? 0 : 1)) < vn->vn_nr_item) || /* S can not be merged with R */ | |
1790 | !tb->FR[h]) { | |
1791 | ||
1792 | RFALSE(!tb->FL[h], | |
1793 | "vs-8245: dc_check_balance_leaf: FL[h] must exist"); | |
1794 | ||
1795 | /* set parameter to merge S[0] with its left neighbor */ | |
1796 | set_parameters(tb, h, -1, 0, 0, NULL, -1, -1); | |
1797 | return CARRY_ON; | |
1798 | } | |
1799 | ||
1800 | /* check whether we can merge S[0] with right neighbor. */ | |
1801 | if (tb->rnum[0] >= vn->vn_nr_item && tb->rbytes == -1) { | |
1802 | set_parameters(tb, h, 0, -1, 0, NULL, -1, -1); | |
1803 | return CARRY_ON; | |
1804 | } | |
1805 | ||
1806 | /* All contents of S[0] can be moved to the neighbors (L[0] & R[0]). Set parameters and return */ | |
1807 | if (is_leaf_removable(tb)) | |
1808 | return CARRY_ON; | |
1809 | ||
1810 | /* Balancing is not required. */ | |
1811 | tb->s0num = vn->vn_nr_item; | |
1812 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1813 | return NO_BALANCING_NEEDED; | |
1814 | } | |
1da177e4 LT |
1815 | |
1816 | /* Check whether current node S[h] is balanced when Decreasing its size by | |
1817 | * Deleting or Cutting. | |
1818 | * Calculate parameters for balancing for current level h. | |
1819 | * Parameters: | |
1820 | * tb tree_balance structure; | |
1821 | * h current level of the node; | |
1822 | * inum item number in S[h]; | |
1823 | * mode d - delete, c - cut. | |
1824 | * Returns: 1 - schedule occurred; | |
1825 | * 0 - balancing for higher levels needed; | |
1826 | * -1 - no balancing for higher levels needed; | |
1827 | * -2 - no disk space. | |
1828 | */ | |
bd4c625c | 1829 | static int dc_check_balance(struct tree_balance *tb, int h) |
1da177e4 | 1830 | { |
bd4c625c LT |
1831 | RFALSE(!(PATH_H_PBUFFER(tb->tb_path, h)), |
1832 | "vs-8250: S is not initialized"); | |
1da177e4 | 1833 | |
bd4c625c LT |
1834 | if (h) |
1835 | return dc_check_balance_internal(tb, h); | |
1836 | else | |
1837 | return dc_check_balance_leaf(tb, h); | |
1da177e4 LT |
1838 | } |
1839 | ||
1da177e4 LT |
1840 | /* Check whether current node S[h] is balanced. |
1841 | * Calculate parameters for balancing for current level h. | |
1842 | * Parameters: | |
1843 | * | |
1844 | * tb tree_balance structure: | |
1845 | * | |
1846 | * tb is a large structure that must be read about in the header file | |
1847 | * at the same time as this procedure if the reader is to successfully | |
1848 | * understand this procedure | |
1849 | * | |
1850 | * h current level of the node; | |
1851 | * inum item number in S[h]; | |
1852 | * mode i - insert, p - paste, d - delete, c - cut. | |
1853 | * Returns: 1 - schedule occurred; | |
1854 | * 0 - balancing for higher levels needed; | |
1855 | * -1 - no balancing for higher levels needed; | |
1856 | * -2 - no disk space. | |
1857 | */ | |
bd4c625c LT |
1858 | static int check_balance(int mode, |
1859 | struct tree_balance *tb, | |
1860 | int h, | |
1861 | int inum, | |
1862 | int pos_in_item, | |
1863 | struct item_head *ins_ih, const void *data) | |
1da177e4 | 1864 | { |
bd4c625c | 1865 | struct virtual_node *vn; |
1da177e4 | 1866 | |
bd4c625c LT |
1867 | vn = tb->tb_vn = (struct virtual_node *)(tb->vn_buf); |
1868 | vn->vn_free_ptr = (char *)(tb->tb_vn + 1); | |
1869 | vn->vn_mode = mode; | |
1870 | vn->vn_affected_item_num = inum; | |
1871 | vn->vn_pos_in_item = pos_in_item; | |
1872 | vn->vn_ins_ih = ins_ih; | |
1873 | vn->vn_data = data; | |
1da177e4 | 1874 | |
bd4c625c LT |
1875 | RFALSE(mode == M_INSERT && !vn->vn_ins_ih, |
1876 | "vs-8255: ins_ih can not be 0 in insert mode"); | |
1da177e4 | 1877 | |
bd4c625c LT |
1878 | if (tb->insert_size[h] > 0) |
1879 | /* Calculate balance parameters when size of node is increasing. */ | |
1880 | return ip_check_balance(tb, h); | |
1da177e4 | 1881 | |
bd4c625c LT |
1882 | /* Calculate balance parameters when size of node is decreasing. */ |
1883 | return dc_check_balance(tb, h); | |
1da177e4 LT |
1884 | } |
1885 | ||
bd4c625c LT |
1886 | /* Check whether parent at the path is the really parent of the current node.*/ |
1887 | static int get_direct_parent(struct tree_balance *p_s_tb, int n_h) | |
1888 | { | |
1889 | struct buffer_head *p_s_bh; | |
fec6d055 | 1890 | struct treepath *p_s_path = p_s_tb->tb_path; |
bd4c625c LT |
1891 | int n_position, |
1892 | n_path_offset = PATH_H_PATH_OFFSET(p_s_tb->tb_path, n_h); | |
1893 | ||
1894 | /* We are in the root or in the new root. */ | |
1895 | if (n_path_offset <= FIRST_PATH_ELEMENT_OFFSET) { | |
1896 | ||
1897 | RFALSE(n_path_offset < FIRST_PATH_ELEMENT_OFFSET - 1, | |
1898 | "PAP-8260: invalid offset in the path"); | |
1899 | ||
1900 | if (PATH_OFFSET_PBUFFER(p_s_path, FIRST_PATH_ELEMENT_OFFSET)-> | |
1901 | b_blocknr == SB_ROOT_BLOCK(p_s_tb->tb_sb)) { | |
1902 | /* Root is not changed. */ | |
1903 | PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1) = NULL; | |
1904 | PATH_OFFSET_POSITION(p_s_path, n_path_offset - 1) = 0; | |
1905 | return CARRY_ON; | |
1906 | } | |
1907 | return REPEAT_SEARCH; /* Root is changed and we must recalculate the path. */ | |
1908 | } | |
1909 | ||
1910 | if (!B_IS_IN_TREE | |
1911 | (p_s_bh = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1))) | |
1912 | return REPEAT_SEARCH; /* Parent in the path is not in the tree. */ | |
1da177e4 | 1913 | |
bd4c625c LT |
1914 | if ((n_position = |
1915 | PATH_OFFSET_POSITION(p_s_path, | |
1916 | n_path_offset - 1)) > B_NR_ITEMS(p_s_bh)) | |
1917 | return REPEAT_SEARCH; | |
1da177e4 | 1918 | |
bd4c625c LT |
1919 | if (B_N_CHILD_NUM(p_s_bh, n_position) != |
1920 | PATH_OFFSET_PBUFFER(p_s_path, n_path_offset)->b_blocknr) | |
1921 | /* Parent in the path is not parent of the current node in the tree. */ | |
1922 | return REPEAT_SEARCH; | |
1923 | ||
1924 | if (buffer_locked(p_s_bh)) { | |
1925 | __wait_on_buffer(p_s_bh); | |
1926 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) | |
1927 | return REPEAT_SEARCH; | |
1da177e4 | 1928 | } |
1da177e4 | 1929 | |
bd4c625c LT |
1930 | return CARRY_ON; /* Parent in the path is unlocked and really parent of the current node. */ |
1931 | } | |
1da177e4 LT |
1932 | |
1933 | /* Using lnum[n_h] and rnum[n_h] we should determine what neighbors | |
1934 | * of S[n_h] we | |
1935 | * need in order to balance S[n_h], and get them if necessary. | |
1936 | * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; | |
1937 | * CARRY_ON - schedule didn't occur while the function worked; | |
1938 | */ | |
bd4c625c LT |
1939 | static int get_neighbors(struct tree_balance *p_s_tb, int n_h) |
1940 | { | |
1941 | int n_child_position, | |
1942 | n_path_offset = PATH_H_PATH_OFFSET(p_s_tb->tb_path, n_h + 1); | |
1943 | unsigned long n_son_number; | |
1944 | struct super_block *p_s_sb = p_s_tb->tb_sb; | |
1945 | struct buffer_head *p_s_bh; | |
1946 | ||
1947 | PROC_INFO_INC(p_s_sb, get_neighbors[n_h]); | |
1948 | ||
1949 | if (p_s_tb->lnum[n_h]) { | |
1950 | /* We need left neighbor to balance S[n_h]. */ | |
1951 | PROC_INFO_INC(p_s_sb, need_l_neighbor[n_h]); | |
1952 | p_s_bh = PATH_OFFSET_PBUFFER(p_s_tb->tb_path, n_path_offset); | |
1953 | ||
1954 | RFALSE(p_s_bh == p_s_tb->FL[n_h] && | |
1955 | !PATH_OFFSET_POSITION(p_s_tb->tb_path, n_path_offset), | |
1956 | "PAP-8270: invalid position in the parent"); | |
1957 | ||
1958 | n_child_position = | |
1959 | (p_s_bh == | |
1960 | p_s_tb->FL[n_h]) ? p_s_tb->lkey[n_h] : B_NR_ITEMS(p_s_tb-> | |
1961 | FL[n_h]); | |
1962 | n_son_number = B_N_CHILD_NUM(p_s_tb->FL[n_h], n_child_position); | |
1963 | p_s_bh = sb_bread(p_s_sb, n_son_number); | |
1964 | if (!p_s_bh) | |
1965 | return IO_ERROR; | |
1966 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) { | |
1967 | decrement_bcount(p_s_bh); | |
1968 | PROC_INFO_INC(p_s_sb, get_neighbors_restart[n_h]); | |
1969 | return REPEAT_SEARCH; | |
1970 | } | |
1971 | ||
1972 | RFALSE(!B_IS_IN_TREE(p_s_tb->FL[n_h]) || | |
1973 | n_child_position > B_NR_ITEMS(p_s_tb->FL[n_h]) || | |
1974 | B_N_CHILD_NUM(p_s_tb->FL[n_h], n_child_position) != | |
1975 | p_s_bh->b_blocknr, "PAP-8275: invalid parent"); | |
1976 | RFALSE(!B_IS_IN_TREE(p_s_bh), "PAP-8280: invalid child"); | |
1977 | RFALSE(!n_h && | |
1978 | B_FREE_SPACE(p_s_bh) != | |
1979 | MAX_CHILD_SIZE(p_s_bh) - | |
1980 | dc_size(B_N_CHILD(p_s_tb->FL[0], n_child_position)), | |
1981 | "PAP-8290: invalid child size of left neighbor"); | |
1982 | ||
1983 | decrement_bcount(p_s_tb->L[n_h]); | |
1984 | p_s_tb->L[n_h] = p_s_bh; | |
1da177e4 | 1985 | } |
bd4c625c LT |
1986 | |
1987 | if (p_s_tb->rnum[n_h]) { /* We need right neighbor to balance S[n_path_offset]. */ | |
1988 | PROC_INFO_INC(p_s_sb, need_r_neighbor[n_h]); | |
1989 | p_s_bh = PATH_OFFSET_PBUFFER(p_s_tb->tb_path, n_path_offset); | |
1990 | ||
1991 | RFALSE(p_s_bh == p_s_tb->FR[n_h] && | |
1992 | PATH_OFFSET_POSITION(p_s_tb->tb_path, | |
1993 | n_path_offset) >= | |
1994 | B_NR_ITEMS(p_s_bh), | |
1995 | "PAP-8295: invalid position in the parent"); | |
1996 | ||
1997 | n_child_position = | |
1998 | (p_s_bh == p_s_tb->FR[n_h]) ? p_s_tb->rkey[n_h] + 1 : 0; | |
1999 | n_son_number = B_N_CHILD_NUM(p_s_tb->FR[n_h], n_child_position); | |
2000 | p_s_bh = sb_bread(p_s_sb, n_son_number); | |
2001 | if (!p_s_bh) | |
2002 | return IO_ERROR; | |
2003 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) { | |
2004 | decrement_bcount(p_s_bh); | |
2005 | PROC_INFO_INC(p_s_sb, get_neighbors_restart[n_h]); | |
2006 | return REPEAT_SEARCH; | |
2007 | } | |
2008 | decrement_bcount(p_s_tb->R[n_h]); | |
2009 | p_s_tb->R[n_h] = p_s_bh; | |
2010 | ||
2011 | RFALSE(!n_h | |
2012 | && B_FREE_SPACE(p_s_bh) != | |
2013 | MAX_CHILD_SIZE(p_s_bh) - | |
2014 | dc_size(B_N_CHILD(p_s_tb->FR[0], n_child_position)), | |
2015 | "PAP-8300: invalid child size of right neighbor (%d != %d - %d)", | |
2016 | B_FREE_SPACE(p_s_bh), MAX_CHILD_SIZE(p_s_bh), | |
2017 | dc_size(B_N_CHILD(p_s_tb->FR[0], n_child_position))); | |
2018 | ||
1da177e4 | 2019 | } |
bd4c625c | 2020 | return CARRY_ON; |
1da177e4 LT |
2021 | } |
2022 | ||
bd4c625c | 2023 | static int get_virtual_node_size(struct super_block *sb, struct buffer_head *bh) |
1da177e4 | 2024 | { |
bd4c625c LT |
2025 | int max_num_of_items; |
2026 | int max_num_of_entries; | |
2027 | unsigned long blocksize = sb->s_blocksize; | |
1da177e4 LT |
2028 | |
2029 | #define MIN_NAME_LEN 1 | |
2030 | ||
bd4c625c LT |
2031 | max_num_of_items = (blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN); |
2032 | max_num_of_entries = (blocksize - BLKH_SIZE - IH_SIZE) / | |
2033 | (DEH_SIZE + MIN_NAME_LEN); | |
1da177e4 | 2034 | |
bd4c625c LT |
2035 | return sizeof(struct virtual_node) + |
2036 | max(max_num_of_items * sizeof(struct virtual_item), | |
2037 | sizeof(struct virtual_item) + sizeof(struct direntry_uarea) + | |
2038 | (max_num_of_entries - 1) * sizeof(__u16)); | |
1da177e4 LT |
2039 | } |
2040 | ||
1da177e4 LT |
2041 | /* maybe we should fail balancing we are going to perform when kmalloc |
2042 | fails several times. But now it will loop until kmalloc gets | |
2043 | required memory */ | |
bd4c625c | 2044 | static int get_mem_for_virtual_node(struct tree_balance *tb) |
1da177e4 | 2045 | { |
bd4c625c LT |
2046 | int check_fs = 0; |
2047 | int size; | |
2048 | char *buf; | |
2049 | ||
2050 | size = get_virtual_node_size(tb->tb_sb, PATH_PLAST_BUFFER(tb->tb_path)); | |
2051 | ||
2052 | if (size > tb->vn_buf_size) { | |
2053 | /* we have to allocate more memory for virtual node */ | |
2054 | if (tb->vn_buf) { | |
2055 | /* free memory allocated before */ | |
d739b42b | 2056 | kfree(tb->vn_buf); |
bd4c625c LT |
2057 | /* this is not needed if kfree is atomic */ |
2058 | check_fs = 1; | |
2059 | } | |
1da177e4 | 2060 | |
bd4c625c LT |
2061 | /* virtual node requires now more memory */ |
2062 | tb->vn_buf_size = size; | |
2063 | ||
2064 | /* get memory for virtual item */ | |
d739b42b | 2065 | buf = kmalloc(size, GFP_ATOMIC | __GFP_NOWARN); |
bd4c625c LT |
2066 | if (!buf) { |
2067 | /* getting memory with GFP_KERNEL priority may involve | |
2068 | balancing now (due to indirect_to_direct conversion on | |
2069 | dcache shrinking). So, release path and collected | |
2070 | resources here */ | |
2071 | free_buffers_in_tb(tb); | |
d739b42b | 2072 | buf = kmalloc(size, GFP_NOFS); |
bd4c625c | 2073 | if (!buf) { |
bd4c625c LT |
2074 | tb->vn_buf_size = 0; |
2075 | } | |
2076 | tb->vn_buf = buf; | |
2077 | schedule(); | |
2078 | return REPEAT_SEARCH; | |
2079 | } | |
1da177e4 | 2080 | |
bd4c625c LT |
2081 | tb->vn_buf = buf; |
2082 | } | |
1da177e4 | 2083 | |
bd4c625c LT |
2084 | if (check_fs && FILESYSTEM_CHANGED_TB(tb)) |
2085 | return REPEAT_SEARCH; | |
1da177e4 | 2086 | |
bd4c625c | 2087 | return CARRY_ON; |
1da177e4 LT |
2088 | } |
2089 | ||
1da177e4 | 2090 | #ifdef CONFIG_REISERFS_CHECK |
bd4c625c LT |
2091 | static void tb_buffer_sanity_check(struct super_block *p_s_sb, |
2092 | struct buffer_head *p_s_bh, | |
2093 | const char *descr, int level) | |
1da177e4 | 2094 | { |
bd4c625c LT |
2095 | if (p_s_bh) { |
2096 | if (atomic_read(&(p_s_bh->b_count)) <= 0) { | |
1da177e4 | 2097 | |
c3a9c210 JM |
2098 | reiserfs_panic(p_s_sb, "jmacd-1", "negative or zero " |
2099 | "reference counter for buffer %s[%d] " | |
2100 | "(%b)", descr, level, p_s_bh); | |
1da177e4 | 2101 | } |
1da177e4 | 2102 | |
bd4c625c | 2103 | if (!buffer_uptodate(p_s_bh)) { |
c3a9c210 JM |
2104 | reiserfs_panic(p_s_sb, "jmacd-2", "buffer is not up " |
2105 | "to date %s[%d] (%b)", | |
bd4c625c LT |
2106 | descr, level, p_s_bh); |
2107 | } | |
1da177e4 | 2108 | |
bd4c625c | 2109 | if (!B_IS_IN_TREE(p_s_bh)) { |
c3a9c210 JM |
2110 | reiserfs_panic(p_s_sb, "jmacd-3", "buffer is not " |
2111 | "in tree %s[%d] (%b)", | |
bd4c625c LT |
2112 | descr, level, p_s_bh); |
2113 | } | |
1da177e4 | 2114 | |
bd4c625c | 2115 | if (p_s_bh->b_bdev != p_s_sb->s_bdev) { |
c3a9c210 JM |
2116 | reiserfs_panic(p_s_sb, "jmacd-4", "buffer has wrong " |
2117 | "device %s[%d] (%b)", | |
bd4c625c | 2118 | descr, level, p_s_bh); |
1da177e4 LT |
2119 | } |
2120 | ||
bd4c625c | 2121 | if (p_s_bh->b_size != p_s_sb->s_blocksize) { |
c3a9c210 JM |
2122 | reiserfs_panic(p_s_sb, "jmacd-5", "buffer has wrong " |
2123 | "blocksize %s[%d] (%b)", | |
bd4c625c | 2124 | descr, level, p_s_bh); |
1da177e4 LT |
2125 | } |
2126 | ||
bd4c625c | 2127 | if (p_s_bh->b_blocknr > SB_BLOCK_COUNT(p_s_sb)) { |
c3a9c210 JM |
2128 | reiserfs_panic(p_s_sb, "jmacd-6", "buffer block " |
2129 | "number too high %s[%d] (%b)", | |
bd4c625c | 2130 | descr, level, p_s_bh); |
1da177e4 | 2131 | } |
bd4c625c LT |
2132 | } |
2133 | } | |
2134 | #else | |
2135 | static void tb_buffer_sanity_check(struct super_block *p_s_sb, | |
2136 | struct buffer_head *p_s_bh, | |
2137 | const char *descr, int level) | |
2138 | {; | |
2139 | } | |
2140 | #endif | |
1da177e4 | 2141 | |
bd4c625c LT |
2142 | static int clear_all_dirty_bits(struct super_block *s, struct buffer_head *bh) |
2143 | { | |
2144 | return reiserfs_prepare_for_journal(s, bh, 0); | |
2145 | } | |
1da177e4 | 2146 | |
bd4c625c LT |
2147 | static int wait_tb_buffers_until_unlocked(struct tree_balance *p_s_tb) |
2148 | { | |
2149 | struct buffer_head *locked; | |
2150 | #ifdef CONFIG_REISERFS_CHECK | |
2151 | int repeat_counter = 0; | |
2152 | #endif | |
2153 | int i; | |
1da177e4 | 2154 | |
bd4c625c | 2155 | do { |
1da177e4 | 2156 | |
bd4c625c LT |
2157 | locked = NULL; |
2158 | ||
2159 | for (i = p_s_tb->tb_path->path_length; | |
2160 | !locked && i > ILLEGAL_PATH_ELEMENT_OFFSET; i--) { | |
2161 | if (PATH_OFFSET_PBUFFER(p_s_tb->tb_path, i)) { | |
2162 | /* if I understand correctly, we can only be sure the last buffer | |
2163 | ** in the path is in the tree --clm | |
2164 | */ | |
2165 | #ifdef CONFIG_REISERFS_CHECK | |
2166 | if (PATH_PLAST_BUFFER(p_s_tb->tb_path) == | |
2167 | PATH_OFFSET_PBUFFER(p_s_tb->tb_path, i)) { | |
2168 | tb_buffer_sanity_check(p_s_tb->tb_sb, | |
2169 | PATH_OFFSET_PBUFFER | |
2170 | (p_s_tb->tb_path, | |
2171 | i), "S", | |
2172 | p_s_tb->tb_path-> | |
2173 | path_length - i); | |
2174 | } | |
2175 | #endif | |
2176 | if (!clear_all_dirty_bits(p_s_tb->tb_sb, | |
2177 | PATH_OFFSET_PBUFFER | |
2178 | (p_s_tb->tb_path, | |
2179 | i))) { | |
2180 | locked = | |
2181 | PATH_OFFSET_PBUFFER(p_s_tb->tb_path, | |
2182 | i); | |
2183 | } | |
2184 | } | |
1da177e4 LT |
2185 | } |
2186 | ||
bd4c625c LT |
2187 | for (i = 0; !locked && i < MAX_HEIGHT && p_s_tb->insert_size[i]; |
2188 | i++) { | |
2189 | ||
2190 | if (p_s_tb->lnum[i]) { | |
2191 | ||
2192 | if (p_s_tb->L[i]) { | |
2193 | tb_buffer_sanity_check(p_s_tb->tb_sb, | |
2194 | p_s_tb->L[i], | |
2195 | "L", i); | |
2196 | if (!clear_all_dirty_bits | |
2197 | (p_s_tb->tb_sb, p_s_tb->L[i])) | |
2198 | locked = p_s_tb->L[i]; | |
2199 | } | |
2200 | ||
2201 | if (!locked && p_s_tb->FL[i]) { | |
2202 | tb_buffer_sanity_check(p_s_tb->tb_sb, | |
2203 | p_s_tb->FL[i], | |
2204 | "FL", i); | |
2205 | if (!clear_all_dirty_bits | |
2206 | (p_s_tb->tb_sb, p_s_tb->FL[i])) | |
2207 | locked = p_s_tb->FL[i]; | |
2208 | } | |
2209 | ||
2210 | if (!locked && p_s_tb->CFL[i]) { | |
2211 | tb_buffer_sanity_check(p_s_tb->tb_sb, | |
2212 | p_s_tb->CFL[i], | |
2213 | "CFL", i); | |
2214 | if (!clear_all_dirty_bits | |
2215 | (p_s_tb->tb_sb, p_s_tb->CFL[i])) | |
2216 | locked = p_s_tb->CFL[i]; | |
2217 | } | |
2218 | ||
2219 | } | |
2220 | ||
2221 | if (!locked && (p_s_tb->rnum[i])) { | |
2222 | ||
2223 | if (p_s_tb->R[i]) { | |
2224 | tb_buffer_sanity_check(p_s_tb->tb_sb, | |
2225 | p_s_tb->R[i], | |
2226 | "R", i); | |
2227 | if (!clear_all_dirty_bits | |
2228 | (p_s_tb->tb_sb, p_s_tb->R[i])) | |
2229 | locked = p_s_tb->R[i]; | |
2230 | } | |
2231 | ||
2232 | if (!locked && p_s_tb->FR[i]) { | |
2233 | tb_buffer_sanity_check(p_s_tb->tb_sb, | |
2234 | p_s_tb->FR[i], | |
2235 | "FR", i); | |
2236 | if (!clear_all_dirty_bits | |
2237 | (p_s_tb->tb_sb, p_s_tb->FR[i])) | |
2238 | locked = p_s_tb->FR[i]; | |
2239 | } | |
2240 | ||
2241 | if (!locked && p_s_tb->CFR[i]) { | |
2242 | tb_buffer_sanity_check(p_s_tb->tb_sb, | |
2243 | p_s_tb->CFR[i], | |
2244 | "CFR", i); | |
2245 | if (!clear_all_dirty_bits | |
2246 | (p_s_tb->tb_sb, p_s_tb->CFR[i])) | |
2247 | locked = p_s_tb->CFR[i]; | |
2248 | } | |
2249 | } | |
2250 | } | |
2251 | /* as far as I can tell, this is not required. The FEB list seems | |
2252 | ** to be full of newly allocated nodes, which will never be locked, | |
2253 | ** dirty, or anything else. | |
2254 | ** To be safe, I'm putting in the checks and waits in. For the moment, | |
2255 | ** they are needed to keep the code in journal.c from complaining | |
2256 | ** about the buffer. That code is inside CONFIG_REISERFS_CHECK as well. | |
2257 | ** --clm | |
2258 | */ | |
2259 | for (i = 0; !locked && i < MAX_FEB_SIZE; i++) { | |
2260 | if (p_s_tb->FEB[i]) { | |
2261 | if (!clear_all_dirty_bits | |
2262 | (p_s_tb->tb_sb, p_s_tb->FEB[i])) | |
2263 | locked = p_s_tb->FEB[i]; | |
2264 | } | |
1da177e4 | 2265 | } |
1da177e4 | 2266 | |
bd4c625c | 2267 | if (locked) { |
1da177e4 | 2268 | #ifdef CONFIG_REISERFS_CHECK |
bd4c625c LT |
2269 | repeat_counter++; |
2270 | if ((repeat_counter % 10000) == 0) { | |
45b03d5e JM |
2271 | reiserfs_warning(p_s_tb->tb_sb, "reiserfs-8200", |
2272 | "too many iterations waiting " | |
2273 | "for buffer to unlock " | |
bd4c625c LT |
2274 | "(%b)", locked); |
2275 | ||
2276 | /* Don't loop forever. Try to recover from possible error. */ | |
2277 | ||
2278 | return (FILESYSTEM_CHANGED_TB(p_s_tb)) ? | |
2279 | REPEAT_SEARCH : CARRY_ON; | |
2280 | } | |
1da177e4 | 2281 | #endif |
bd4c625c LT |
2282 | __wait_on_buffer(locked); |
2283 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) { | |
2284 | return REPEAT_SEARCH; | |
2285 | } | |
2286 | } | |
1da177e4 | 2287 | |
bd4c625c | 2288 | } while (locked); |
1da177e4 | 2289 | |
bd4c625c | 2290 | return CARRY_ON; |
1da177e4 LT |
2291 | } |
2292 | ||
1da177e4 LT |
2293 | /* Prepare for balancing, that is |
2294 | * get all necessary parents, and neighbors; | |
2295 | * analyze what and where should be moved; | |
2296 | * get sufficient number of new nodes; | |
2297 | * Balancing will start only after all resources will be collected at a time. | |
2298 | * | |
2299 | * When ported to SMP kernels, only at the last moment after all needed nodes | |
2300 | * are collected in cache, will the resources be locked using the usual | |
2301 | * textbook ordered lock acquisition algorithms. Note that ensuring that | |
2302 | * this code neither write locks what it does not need to write lock nor locks out of order | |
2303 | * will be a pain in the butt that could have been avoided. Grumble grumble. -Hans | |
2304 | * | |
2305 | * fix is meant in the sense of render unchanging | |
2306 | * | |
2307 | * Latency might be improved by first gathering a list of what buffers are needed | |
2308 | * and then getting as many of them in parallel as possible? -Hans | |
2309 | * | |
2310 | * Parameters: | |
2311 | * op_mode i - insert, d - delete, c - cut (truncate), p - paste (append) | |
2312 | * tb tree_balance structure; | |
2313 | * inum item number in S[h]; | |
2314 | * pos_in_item - comment this if you can | |
2315 | * ins_ih & ins_sd are used when inserting | |
2316 | * Returns: 1 - schedule occurred while the function worked; | |
2317 | * 0 - schedule didn't occur while the function worked; | |
2318 | * -1 - if no_disk_space | |
2319 | */ | |
2320 | ||
bd4c625c LT |
2321 | int fix_nodes(int n_op_mode, struct tree_balance *p_s_tb, struct item_head *p_s_ins_ih, // item head of item being inserted |
2322 | const void *data // inserted item or data to be pasted | |
2323 | ) | |
2324 | { | |
2325 | int n_ret_value, n_h, n_item_num = PATH_LAST_POSITION(p_s_tb->tb_path); | |
2326 | int n_pos_in_item; | |
1da177e4 | 2327 | |
bd4c625c LT |
2328 | /* we set wait_tb_buffers_run when we have to restore any dirty bits cleared |
2329 | ** during wait_tb_buffers_run | |
2330 | */ | |
2331 | int wait_tb_buffers_run = 0; | |
2332 | struct buffer_head *p_s_tbS0 = PATH_PLAST_BUFFER(p_s_tb->tb_path); | |
1da177e4 | 2333 | |
bd4c625c LT |
2334 | ++REISERFS_SB(p_s_tb->tb_sb)->s_fix_nodes; |
2335 | ||
2336 | n_pos_in_item = p_s_tb->tb_path->pos_in_item; | |
2337 | ||
2338 | p_s_tb->fs_gen = get_generation(p_s_tb->tb_sb); | |
1da177e4 | 2339 | |
bd4c625c LT |
2340 | /* we prepare and log the super here so it will already be in the |
2341 | ** transaction when do_balance needs to change it. | |
2342 | ** This way do_balance won't have to schedule when trying to prepare | |
2343 | ** the super for logging | |
2344 | */ | |
2345 | reiserfs_prepare_for_journal(p_s_tb->tb_sb, | |
2346 | SB_BUFFER_WITH_SB(p_s_tb->tb_sb), 1); | |
2347 | journal_mark_dirty(p_s_tb->transaction_handle, p_s_tb->tb_sb, | |
2348 | SB_BUFFER_WITH_SB(p_s_tb->tb_sb)); | |
2349 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) | |
2350 | return REPEAT_SEARCH; | |
1da177e4 | 2351 | |
bd4c625c LT |
2352 | /* if it possible in indirect_to_direct conversion */ |
2353 | if (buffer_locked(p_s_tbS0)) { | |
2354 | __wait_on_buffer(p_s_tbS0); | |
2355 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) | |
2356 | return REPEAT_SEARCH; | |
2357 | } | |
2358 | #ifdef CONFIG_REISERFS_CHECK | |
2359 | if (cur_tb) { | |
2360 | print_cur_tb("fix_nodes"); | |
c3a9c210 JM |
2361 | reiserfs_panic(p_s_tb->tb_sb, "PAP-8305", |
2362 | "there is pending do_balance"); | |
bd4c625c | 2363 | } |
1da177e4 | 2364 | |
bd4c625c | 2365 | if (!buffer_uptodate(p_s_tbS0) || !B_IS_IN_TREE(p_s_tbS0)) { |
c3a9c210 JM |
2366 | reiserfs_panic(p_s_tb->tb_sb, "PAP-8320", "S[0] (%b %z) is " |
2367 | "not uptodate at the beginning of fix_nodes " | |
2368 | "or not in tree (mode %c)", | |
bd4c625c | 2369 | p_s_tbS0, p_s_tbS0, n_op_mode); |
1da177e4 LT |
2370 | } |
2371 | ||
bd4c625c LT |
2372 | /* Check parameters. */ |
2373 | switch (n_op_mode) { | |
2374 | case M_INSERT: | |
2375 | if (n_item_num <= 0 || n_item_num > B_NR_ITEMS(p_s_tbS0)) | |
c3a9c210 JM |
2376 | reiserfs_panic(p_s_tb->tb_sb, "PAP-8330", "Incorrect " |
2377 | "item number %d (in S0 - %d) in case " | |
2378 | "of insert", n_item_num, | |
2379 | B_NR_ITEMS(p_s_tbS0)); | |
bd4c625c LT |
2380 | break; |
2381 | case M_PASTE: | |
2382 | case M_DELETE: | |
2383 | case M_CUT: | |
2384 | if (n_item_num < 0 || n_item_num >= B_NR_ITEMS(p_s_tbS0)) { | |
2385 | print_block(p_s_tbS0, 0, -1, -1); | |
c3a9c210 JM |
2386 | reiserfs_panic(p_s_tb->tb_sb, "PAP-8335", "Incorrect " |
2387 | "item number(%d); mode = %c " | |
2388 | "insert_size = %d", | |
bd4c625c LT |
2389 | n_item_num, n_op_mode, |
2390 | p_s_tb->insert_size[0]); | |
1da177e4 | 2391 | } |
1da177e4 | 2392 | break; |
bd4c625c | 2393 | default: |
c3a9c210 JM |
2394 | reiserfs_panic(p_s_tb->tb_sb, "PAP-8340", "Incorrect mode " |
2395 | "of operation"); | |
1da177e4 | 2396 | } |
bd4c625c | 2397 | #endif |
1da177e4 | 2398 | |
bd4c625c LT |
2399 | if (get_mem_for_virtual_node(p_s_tb) == REPEAT_SEARCH) |
2400 | // FIXME: maybe -ENOMEM when tb->vn_buf == 0? Now just repeat | |
2401 | return REPEAT_SEARCH; | |
1da177e4 | 2402 | |
bd4c625c LT |
2403 | /* Starting from the leaf level; for all levels n_h of the tree. */ |
2404 | for (n_h = 0; n_h < MAX_HEIGHT && p_s_tb->insert_size[n_h]; n_h++) { | |
2405 | if ((n_ret_value = get_direct_parent(p_s_tb, n_h)) != CARRY_ON) { | |
2406 | goto repeat; | |
2407 | } | |
1da177e4 | 2408 | |
bd4c625c LT |
2409 | if ((n_ret_value = |
2410 | check_balance(n_op_mode, p_s_tb, n_h, n_item_num, | |
2411 | n_pos_in_item, p_s_ins_ih, | |
2412 | data)) != CARRY_ON) { | |
2413 | if (n_ret_value == NO_BALANCING_NEEDED) { | |
2414 | /* No balancing for higher levels needed. */ | |
2415 | if ((n_ret_value = | |
2416 | get_neighbors(p_s_tb, n_h)) != CARRY_ON) { | |
2417 | goto repeat; | |
2418 | } | |
2419 | if (n_h != MAX_HEIGHT - 1) | |
2420 | p_s_tb->insert_size[n_h + 1] = 0; | |
2421 | /* ok, analysis and resource gathering are complete */ | |
2422 | break; | |
2423 | } | |
2424 | goto repeat; | |
2425 | } | |
1da177e4 | 2426 | |
bd4c625c LT |
2427 | if ((n_ret_value = get_neighbors(p_s_tb, n_h)) != CARRY_ON) { |
2428 | goto repeat; | |
1da177e4 | 2429 | } |
bd4c625c LT |
2430 | |
2431 | if ((n_ret_value = get_empty_nodes(p_s_tb, n_h)) != CARRY_ON) { | |
2432 | goto repeat; /* No disk space, or schedule occurred and | |
2433 | analysis may be invalid and needs to be redone. */ | |
2434 | } | |
2435 | ||
2436 | if (!PATH_H_PBUFFER(p_s_tb->tb_path, n_h)) { | |
2437 | /* We have a positive insert size but no nodes exist on this | |
2438 | level, this means that we are creating a new root. */ | |
2439 | ||
2440 | RFALSE(p_s_tb->blknum[n_h] != 1, | |
2441 | "PAP-8350: creating new empty root"); | |
2442 | ||
2443 | if (n_h < MAX_HEIGHT - 1) | |
2444 | p_s_tb->insert_size[n_h + 1] = 0; | |
2445 | } else if (!PATH_H_PBUFFER(p_s_tb->tb_path, n_h + 1)) { | |
2446 | if (p_s_tb->blknum[n_h] > 1) { | |
2447 | /* The tree needs to be grown, so this node S[n_h] | |
2448 | which is the root node is split into two nodes, | |
2449 | and a new node (S[n_h+1]) will be created to | |
2450 | become the root node. */ | |
2451 | ||
2452 | RFALSE(n_h == MAX_HEIGHT - 1, | |
2453 | "PAP-8355: attempt to create too high of a tree"); | |
2454 | ||
2455 | p_s_tb->insert_size[n_h + 1] = | |
2456 | (DC_SIZE + | |
2457 | KEY_SIZE) * (p_s_tb->blknum[n_h] - 1) + | |
2458 | DC_SIZE; | |
2459 | } else if (n_h < MAX_HEIGHT - 1) | |
2460 | p_s_tb->insert_size[n_h + 1] = 0; | |
2461 | } else | |
2462 | p_s_tb->insert_size[n_h + 1] = | |
2463 | (DC_SIZE + KEY_SIZE) * (p_s_tb->blknum[n_h] - 1); | |
1da177e4 | 2464 | } |
1da177e4 | 2465 | |
bd4c625c LT |
2466 | if ((n_ret_value = wait_tb_buffers_until_unlocked(p_s_tb)) == CARRY_ON) { |
2467 | if (FILESYSTEM_CHANGED_TB(p_s_tb)) { | |
2468 | wait_tb_buffers_run = 1; | |
2469 | n_ret_value = REPEAT_SEARCH; | |
2470 | goto repeat; | |
2471 | } else { | |
2472 | return CARRY_ON; | |
2473 | } | |
1da177e4 | 2474 | } else { |
bd4c625c LT |
2475 | wait_tb_buffers_run = 1; |
2476 | goto repeat; | |
1da177e4 LT |
2477 | } |
2478 | ||
bd4c625c LT |
2479 | repeat: |
2480 | // fix_nodes was unable to perform its calculation due to | |
2481 | // filesystem got changed under us, lack of free disk space or i/o | |
2482 | // failure. If the first is the case - the search will be | |
2483 | // repeated. For now - free all resources acquired so far except | |
2484 | // for the new allocated nodes | |
2485 | { | |
2486 | int i; | |
2487 | ||
2488 | /* Release path buffers. */ | |
2489 | if (wait_tb_buffers_run) { | |
2490 | pathrelse_and_restore(p_s_tb->tb_sb, p_s_tb->tb_path); | |
2491 | } else { | |
2492 | pathrelse(p_s_tb->tb_path); | |
2493 | } | |
2494 | /* brelse all resources collected for balancing */ | |
2495 | for (i = 0; i < MAX_HEIGHT; i++) { | |
2496 | if (wait_tb_buffers_run) { | |
2497 | reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, | |
2498 | p_s_tb->L[i]); | |
2499 | reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, | |
2500 | p_s_tb->R[i]); | |
2501 | reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, | |
2502 | p_s_tb->FL[i]); | |
2503 | reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, | |
2504 | p_s_tb->FR[i]); | |
2505 | reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, | |
2506 | p_s_tb-> | |
2507 | CFL[i]); | |
2508 | reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, | |
2509 | p_s_tb-> | |
2510 | CFR[i]); | |
2511 | } | |
2512 | ||
2513 | brelse(p_s_tb->L[i]); | |
2514 | p_s_tb->L[i] = NULL; | |
2515 | brelse(p_s_tb->R[i]); | |
2516 | p_s_tb->R[i] = NULL; | |
2517 | brelse(p_s_tb->FL[i]); | |
2518 | p_s_tb->FL[i] = NULL; | |
2519 | brelse(p_s_tb->FR[i]); | |
2520 | p_s_tb->FR[i] = NULL; | |
2521 | brelse(p_s_tb->CFL[i]); | |
2522 | p_s_tb->CFL[i] = NULL; | |
2523 | brelse(p_s_tb->CFR[i]); | |
2524 | p_s_tb->CFR[i] = NULL; | |
2525 | } | |
2526 | ||
2527 | if (wait_tb_buffers_run) { | |
2528 | for (i = 0; i < MAX_FEB_SIZE; i++) { | |
2529 | if (p_s_tb->FEB[i]) { | |
2530 | reiserfs_restore_prepared_buffer | |
2531 | (p_s_tb->tb_sb, p_s_tb->FEB[i]); | |
2532 | } | |
2533 | } | |
1da177e4 | 2534 | } |
bd4c625c | 2535 | return n_ret_value; |
1da177e4 | 2536 | } |
1da177e4 LT |
2537 | |
2538 | } | |
2539 | ||
1da177e4 LT |
2540 | /* Anatoly will probably forgive me renaming p_s_tb to tb. I just |
2541 | wanted to make lines shorter */ | |
bd4c625c | 2542 | void unfix_nodes(struct tree_balance *tb) |
1da177e4 | 2543 | { |
bd4c625c | 2544 | int i; |
1da177e4 | 2545 | |
bd4c625c LT |
2546 | /* Release path buffers. */ |
2547 | pathrelse_and_restore(tb->tb_sb, tb->tb_path); | |
1da177e4 | 2548 | |
bd4c625c LT |
2549 | /* brelse all resources collected for balancing */ |
2550 | for (i = 0; i < MAX_HEIGHT; i++) { | |
2551 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->L[i]); | |
2552 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->R[i]); | |
2553 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FL[i]); | |
2554 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FR[i]); | |
2555 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFL[i]); | |
2556 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFR[i]); | |
2557 | ||
2558 | brelse(tb->L[i]); | |
2559 | brelse(tb->R[i]); | |
2560 | brelse(tb->FL[i]); | |
2561 | brelse(tb->FR[i]); | |
2562 | brelse(tb->CFL[i]); | |
2563 | brelse(tb->CFR[i]); | |
2564 | } | |
1da177e4 | 2565 | |
bd4c625c LT |
2566 | /* deal with list of allocated (used and unused) nodes */ |
2567 | for (i = 0; i < MAX_FEB_SIZE; i++) { | |
2568 | if (tb->FEB[i]) { | |
2569 | b_blocknr_t blocknr = tb->FEB[i]->b_blocknr; | |
2570 | /* de-allocated block which was not used by balancing and | |
2571 | bforget about buffer for it */ | |
2572 | brelse(tb->FEB[i]); | |
2573 | reiserfs_free_block(tb->transaction_handle, NULL, | |
2574 | blocknr, 0); | |
2575 | } | |
2576 | if (tb->used[i]) { | |
2577 | /* release used as new nodes including a new root */ | |
2578 | brelse(tb->used[i]); | |
2579 | } | |
2580 | } | |
1da177e4 | 2581 | |
d739b42b | 2582 | kfree(tb->vn_buf); |
1da177e4 | 2583 | |
bd4c625c | 2584 | } |