Commit | Line | Data |
---|---|---|
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 | |
0222e657 JM |
33 | ** |
34 | ** | |
1da177e4 LT |
35 | **/ |
36 | ||
1da177e4 | 37 | #include <linux/time.h> |
5a0e3ad6 | 38 | #include <linux/slab.h> |
1da177e4 | 39 | #include <linux/string.h> |
f466c6fd | 40 | #include "reiserfs.h" |
1da177e4 LT |
41 | #include <linux/buffer_head.h> |
42 | ||
1da177e4 LT |
43 | /* To make any changes in the tree we find a node, that contains item |
44 | to be changed/deleted or position in the node we insert a new item | |
45 | to. We call this node S. To do balancing we need to decide what we | |
46 | will shift to left/right neighbor, or to a new node, where new item | |
47 | will be etc. To make this analysis simpler we build virtual | |
48 | node. Virtual node is an array of items, that will replace items of | |
49 | node S. (For instance if we are going to delete an item, virtual | |
50 | node does not contain it). Virtual node keeps information about | |
51 | item sizes and types, mergeability of first and last items, sizes | |
52 | of all entries in directory item. We use this array of items when | |
53 | calculating what we can shift to neighbors and how many nodes we | |
54 | have to have if we do not any shiftings, if we shift to left/right | |
55 | neighbor or to both. */ | |
56 | ||
1da177e4 | 57 | /* taking item number in virtual node, returns number of item, that it has in source buffer */ |
bd4c625c | 58 | static inline int old_item_num(int new_num, int affected_item_num, int mode) |
1da177e4 | 59 | { |
bd4c625c LT |
60 | if (mode == M_PASTE || mode == M_CUT || new_num < affected_item_num) |
61 | return new_num; | |
1da177e4 | 62 | |
bd4c625c | 63 | if (mode == M_INSERT) { |
1da177e4 | 64 | |
bd4c625c LT |
65 | RFALSE(new_num == 0, |
66 | "vs-8005: for INSERT mode and item number of inserted item"); | |
1da177e4 | 67 | |
bd4c625c LT |
68 | return new_num - 1; |
69 | } | |
1da177e4 | 70 | |
bd4c625c LT |
71 | RFALSE(mode != M_DELETE, |
72 | "vs-8010: old_item_num: mode must be M_DELETE (mode = \'%c\'", | |
73 | mode); | |
74 | /* delete mode */ | |
75 | return new_num + 1; | |
1da177e4 LT |
76 | } |
77 | ||
bd4c625c | 78 | static void create_virtual_node(struct tree_balance *tb, int h) |
1da177e4 | 79 | { |
bd4c625c LT |
80 | struct item_head *ih; |
81 | struct virtual_node *vn = tb->tb_vn; | |
82 | int new_num; | |
83 | struct buffer_head *Sh; /* this comes from tb->S[h] */ | |
1da177e4 | 84 | |
bd4c625c | 85 | Sh = PATH_H_PBUFFER(tb->tb_path, h); |
1da177e4 | 86 | |
bd4c625c LT |
87 | /* size of changed node */ |
88 | vn->vn_size = | |
89 | MAX_CHILD_SIZE(Sh) - B_FREE_SPACE(Sh) + tb->insert_size[h]; | |
1da177e4 | 90 | |
bd4c625c LT |
91 | /* for internal nodes array if virtual items is not created */ |
92 | if (h) { | |
93 | vn->vn_nr_item = (vn->vn_size - DC_SIZE) / (DC_SIZE + KEY_SIZE); | |
94 | return; | |
1da177e4 | 95 | } |
1da177e4 | 96 | |
bd4c625c LT |
97 | /* number of items in virtual node */ |
98 | vn->vn_nr_item = | |
99 | B_NR_ITEMS(Sh) + ((vn->vn_mode == M_INSERT) ? 1 : 0) - | |
100 | ((vn->vn_mode == M_DELETE) ? 1 : 0); | |
101 | ||
102 | /* first virtual item */ | |
103 | vn->vn_vi = (struct virtual_item *)(tb->tb_vn + 1); | |
104 | memset(vn->vn_vi, 0, vn->vn_nr_item * sizeof(struct virtual_item)); | |
105 | vn->vn_free_ptr += vn->vn_nr_item * sizeof(struct virtual_item); | |
106 | ||
107 | /* first item in the node */ | |
108 | ih = B_N_PITEM_HEAD(Sh, 0); | |
109 | ||
110 | /* define the mergeability for 0-th item (if it is not being deleted) */ | |
111 | if (op_is_left_mergeable(&(ih->ih_key), Sh->b_size) | |
112 | && (vn->vn_mode != M_DELETE || vn->vn_affected_item_num)) | |
113 | vn->vn_vi[0].vi_type |= VI_TYPE_LEFT_MERGEABLE; | |
114 | ||
115 | /* go through all items those remain in the virtual node (except for the new (inserted) one) */ | |
116 | for (new_num = 0; new_num < vn->vn_nr_item; new_num++) { | |
117 | int j; | |
118 | struct virtual_item *vi = vn->vn_vi + new_num; | |
119 | int is_affected = | |
120 | ((new_num != vn->vn_affected_item_num) ? 0 : 1); | |
121 | ||
122 | if (is_affected && vn->vn_mode == M_INSERT) | |
123 | continue; | |
124 | ||
125 | /* get item number in source node */ | |
126 | j = old_item_num(new_num, vn->vn_affected_item_num, | |
127 | vn->vn_mode); | |
128 | ||
129 | vi->vi_item_len += ih_item_len(ih + j) + IH_SIZE; | |
130 | vi->vi_ih = ih + j; | |
131 | vi->vi_item = B_I_PITEM(Sh, ih + j); | |
132 | vi->vi_uarea = vn->vn_free_ptr; | |
133 | ||
134 | // FIXME: there is no check, that item operation did not | |
135 | // consume too much memory | |
136 | vn->vn_free_ptr += | |
137 | op_create_vi(vn, vi, is_affected, tb->insert_size[0]); | |
138 | if (tb->vn_buf + tb->vn_buf_size < vn->vn_free_ptr) | |
c3a9c210 | 139 | reiserfs_panic(tb->tb_sb, "vs-8030", |
bd4c625c LT |
140 | "virtual node space consumed"); |
141 | ||
142 | if (!is_affected) | |
143 | /* this is not being changed */ | |
144 | continue; | |
145 | ||
146 | if (vn->vn_mode == M_PASTE || vn->vn_mode == M_CUT) { | |
147 | vn->vn_vi[new_num].vi_item_len += tb->insert_size[0]; | |
148 | vi->vi_new_data = vn->vn_data; // pointer to data which is going to be pasted | |
149 | } | |
1da177e4 | 150 | } |
bd4c625c LT |
151 | |
152 | /* virtual inserted item is not defined yet */ | |
153 | if (vn->vn_mode == M_INSERT) { | |
154 | struct virtual_item *vi = vn->vn_vi + vn->vn_affected_item_num; | |
155 | ||
9dce07f1 | 156 | RFALSE(vn->vn_ins_ih == NULL, |
bd4c625c LT |
157 | "vs-8040: item header of inserted item is not specified"); |
158 | vi->vi_item_len = tb->insert_size[0]; | |
159 | vi->vi_ih = vn->vn_ins_ih; | |
160 | vi->vi_item = vn->vn_data; | |
161 | vi->vi_uarea = vn->vn_free_ptr; | |
162 | ||
163 | op_create_vi(vn, vi, 0 /*not pasted or cut */ , | |
164 | tb->insert_size[0]); | |
165 | } | |
166 | ||
167 | /* set right merge flag we take right delimiting key and check whether it is a mergeable item */ | |
168 | if (tb->CFR[0]) { | |
169 | struct reiserfs_key *key; | |
170 | ||
171 | key = B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0]); | |
172 | if (op_is_left_mergeable(key, Sh->b_size) | |
173 | && (vn->vn_mode != M_DELETE | |
174 | || vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1)) | |
175 | vn->vn_vi[vn->vn_nr_item - 1].vi_type |= | |
176 | VI_TYPE_RIGHT_MERGEABLE; | |
177 | ||
178 | #ifdef CONFIG_REISERFS_CHECK | |
179 | if (op_is_left_mergeable(key, Sh->b_size) && | |
180 | !(vn->vn_mode != M_DELETE | |
181 | || vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1)) { | |
182 | /* we delete last item and it could be merged with right neighbor's first item */ | |
183 | if (! | |
184 | (B_NR_ITEMS(Sh) == 1 | |
185 | && is_direntry_le_ih(B_N_PITEM_HEAD(Sh, 0)) | |
186 | && I_ENTRY_COUNT(B_N_PITEM_HEAD(Sh, 0)) == 1)) { | |
187 | /* node contains more than 1 item, or item is not directory item, or this item contains more than 1 entry */ | |
188 | print_block(Sh, 0, -1, -1); | |
c3a9c210 JM |
189 | reiserfs_panic(tb->tb_sb, "vs-8045", |
190 | "rdkey %k, affected item==%d " | |
191 | "(mode==%c) Must be %c", | |
bd4c625c LT |
192 | key, vn->vn_affected_item_num, |
193 | vn->vn_mode, M_DELETE); | |
cd02b966 | 194 | } |
bd4c625c | 195 | } |
1da177e4 | 196 | #endif |
1da177e4 | 197 | |
bd4c625c LT |
198 | } |
199 | } | |
1da177e4 LT |
200 | |
201 | /* using virtual node check, how many items can be shifted to left | |
202 | neighbor */ | |
bd4c625c | 203 | static void check_left(struct tree_balance *tb, int h, int cur_free) |
1da177e4 | 204 | { |
bd4c625c LT |
205 | int i; |
206 | struct virtual_node *vn = tb->tb_vn; | |
207 | struct virtual_item *vi; | |
208 | int d_size, ih_size; | |
1da177e4 | 209 | |
bd4c625c | 210 | RFALSE(cur_free < 0, "vs-8050: cur_free (%d) < 0", cur_free); |
1da177e4 | 211 | |
bd4c625c LT |
212 | /* internal level */ |
213 | if (h > 0) { | |
214 | tb->lnum[h] = cur_free / (DC_SIZE + KEY_SIZE); | |
215 | return; | |
216 | } | |
1da177e4 | 217 | |
bd4c625c | 218 | /* leaf level */ |
1da177e4 | 219 | |
bd4c625c LT |
220 | if (!cur_free || !vn->vn_nr_item) { |
221 | /* no free space or nothing to move */ | |
222 | tb->lnum[h] = 0; | |
223 | tb->lbytes = -1; | |
224 | return; | |
225 | } | |
1da177e4 | 226 | |
bd4c625c LT |
227 | RFALSE(!PATH_H_PPARENT(tb->tb_path, 0), |
228 | "vs-8055: parent does not exist or invalid"); | |
1da177e4 | 229 | |
bd4c625c LT |
230 | vi = vn->vn_vi; |
231 | if ((unsigned int)cur_free >= | |
232 | (vn->vn_size - | |
233 | ((vi->vi_type & VI_TYPE_LEFT_MERGEABLE) ? IH_SIZE : 0))) { | |
234 | /* all contents of S[0] fits into L[0] */ | |
1da177e4 | 235 | |
bd4c625c LT |
236 | RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE, |
237 | "vs-8055: invalid mode or balance condition failed"); | |
1da177e4 | 238 | |
bd4c625c LT |
239 | tb->lnum[0] = vn->vn_nr_item; |
240 | tb->lbytes = -1; | |
241 | return; | |
1da177e4 | 242 | } |
bd4c625c LT |
243 | |
244 | d_size = 0, ih_size = IH_SIZE; | |
245 | ||
246 | /* first item may be merge with last item in left neighbor */ | |
247 | if (vi->vi_type & VI_TYPE_LEFT_MERGEABLE) | |
248 | d_size = -((int)IH_SIZE), ih_size = 0; | |
249 | ||
250 | tb->lnum[0] = 0; | |
251 | for (i = 0; i < vn->vn_nr_item; | |
252 | i++, ih_size = IH_SIZE, d_size = 0, vi++) { | |
253 | d_size += vi->vi_item_len; | |
254 | if (cur_free >= d_size) { | |
255 | /* the item can be shifted entirely */ | |
256 | cur_free -= d_size; | |
257 | tb->lnum[0]++; | |
258 | continue; | |
259 | } | |
260 | ||
261 | /* the item cannot be shifted entirely, try to split it */ | |
262 | /* check whether L[0] can hold ih and at least one byte of the item body */ | |
263 | if (cur_free <= ih_size) { | |
264 | /* cannot shift even a part of the current item */ | |
265 | tb->lbytes = -1; | |
266 | return; | |
267 | } | |
268 | cur_free -= ih_size; | |
269 | ||
270 | tb->lbytes = op_check_left(vi, cur_free, 0, 0); | |
271 | if (tb->lbytes != -1) | |
272 | /* count partially shifted item */ | |
273 | tb->lnum[0]++; | |
274 | ||
275 | break; | |
1da177e4 | 276 | } |
1da177e4 | 277 | |
bd4c625c LT |
278 | return; |
279 | } | |
1da177e4 LT |
280 | |
281 | /* using virtual node check, how many items can be shifted to right | |
282 | neighbor */ | |
bd4c625c | 283 | static void check_right(struct tree_balance *tb, int h, int cur_free) |
1da177e4 | 284 | { |
bd4c625c LT |
285 | int i; |
286 | struct virtual_node *vn = tb->tb_vn; | |
287 | struct virtual_item *vi; | |
288 | int d_size, ih_size; | |
289 | ||
290 | RFALSE(cur_free < 0, "vs-8070: cur_free < 0"); | |
291 | ||
292 | /* internal level */ | |
293 | if (h > 0) { | |
294 | tb->rnum[h] = cur_free / (DC_SIZE + KEY_SIZE); | |
295 | return; | |
1da177e4 | 296 | } |
bd4c625c LT |
297 | |
298 | /* leaf level */ | |
299 | ||
300 | if (!cur_free || !vn->vn_nr_item) { | |
301 | /* no free space */ | |
302 | tb->rnum[h] = 0; | |
303 | tb->rbytes = -1; | |
304 | return; | |
1da177e4 | 305 | } |
1da177e4 | 306 | |
bd4c625c LT |
307 | RFALSE(!PATH_H_PPARENT(tb->tb_path, 0), |
308 | "vs-8075: parent does not exist or invalid"); | |
309 | ||
310 | vi = vn->vn_vi + vn->vn_nr_item - 1; | |
311 | if ((unsigned int)cur_free >= | |
312 | (vn->vn_size - | |
313 | ((vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) ? IH_SIZE : 0))) { | |
314 | /* all contents of S[0] fits into R[0] */ | |
315 | ||
316 | RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE, | |
317 | "vs-8080: invalid mode or balance condition failed"); | |
318 | ||
319 | tb->rnum[h] = vn->vn_nr_item; | |
320 | tb->rbytes = -1; | |
321 | return; | |
322 | } | |
323 | ||
324 | d_size = 0, ih_size = IH_SIZE; | |
325 | ||
326 | /* last item may be merge with first item in right neighbor */ | |
327 | if (vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) | |
328 | d_size = -(int)IH_SIZE, ih_size = 0; | |
329 | ||
330 | tb->rnum[0] = 0; | |
331 | for (i = vn->vn_nr_item - 1; i >= 0; | |
332 | i--, d_size = 0, ih_size = IH_SIZE, vi--) { | |
333 | d_size += vi->vi_item_len; | |
334 | if (cur_free >= d_size) { | |
335 | /* the item can be shifted entirely */ | |
336 | cur_free -= d_size; | |
337 | tb->rnum[0]++; | |
338 | continue; | |
339 | } | |
340 | ||
341 | /* check whether R[0] can hold ih and at least one byte of the item body */ | |
342 | if (cur_free <= ih_size) { /* cannot shift even a part of the current item */ | |
343 | tb->rbytes = -1; | |
344 | return; | |
345 | } | |
346 | ||
347 | /* R[0] can hold the header of the item and at least one byte of its body */ | |
348 | cur_free -= ih_size; /* cur_free is still > 0 */ | |
349 | ||
350 | tb->rbytes = op_check_right(vi, cur_free); | |
351 | if (tb->rbytes != -1) | |
352 | /* count partially shifted item */ | |
353 | tb->rnum[0]++; | |
354 | ||
355 | break; | |
356 | } | |
357 | ||
358 | return; | |
359 | } | |
1da177e4 LT |
360 | |
361 | /* | |
362 | * from - number of items, which are shifted to left neighbor entirely | |
363 | * to - number of item, which are shifted to right neighbor entirely | |
364 | * from_bytes - number of bytes of boundary item (or directory entries) which are shifted to left neighbor | |
365 | * to_bytes - number of bytes of boundary item (or directory entries) which are shifted to right neighbor */ | |
bd4c625c LT |
366 | static int get_num_ver(int mode, struct tree_balance *tb, int h, |
367 | int from, int from_bytes, | |
368 | int to, int to_bytes, short *snum012, int flow) | |
1da177e4 | 369 | { |
bd4c625c LT |
370 | int i; |
371 | int cur_free; | |
372 | // int bytes; | |
373 | int units; | |
374 | struct virtual_node *vn = tb->tb_vn; | |
375 | // struct virtual_item * vi; | |
376 | ||
377 | int total_node_size, max_node_size, current_item_size; | |
378 | int needed_nodes; | |
379 | int start_item, /* position of item we start filling node from */ | |
380 | end_item, /* position of item we finish filling node by */ | |
0222e657 | 381 | start_bytes, /* number of first bytes (entries for directory) of start_item-th item |
bd4c625c | 382 | we do not include into node that is being filled */ |
0222e657 | 383 | end_bytes; /* number of last bytes (entries for directory) of end_item-th item |
bd4c625c LT |
384 | we do node include into node that is being filled */ |
385 | int split_item_positions[2]; /* these are positions in virtual item of | |
386 | items, that are split between S[0] and | |
387 | S1new and S1new and S2new */ | |
388 | ||
389 | split_item_positions[0] = -1; | |
390 | split_item_positions[1] = -1; | |
391 | ||
392 | /* We only create additional nodes if we are in insert or paste mode | |
393 | or we are in replace mode at the internal level. If h is 0 and | |
394 | the mode is M_REPLACE then in fix_nodes we change the mode to | |
395 | paste or insert before we get here in the code. */ | |
396 | RFALSE(tb->insert_size[h] < 0 || (mode != M_INSERT && mode != M_PASTE), | |
397 | "vs-8100: insert_size < 0 in overflow"); | |
398 | ||
399 | max_node_size = MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, h)); | |
400 | ||
401 | /* snum012 [0-2] - number of items, that lay | |
402 | to S[0], first new node and second new node */ | |
403 | snum012[3] = -1; /* s1bytes */ | |
404 | snum012[4] = -1; /* s2bytes */ | |
405 | ||
406 | /* internal level */ | |
407 | if (h > 0) { | |
408 | i = ((to - from) * (KEY_SIZE + DC_SIZE) + DC_SIZE); | |
409 | if (i == max_node_size) | |
410 | return 1; | |
411 | return (i / max_node_size + 1); | |
1da177e4 LT |
412 | } |
413 | ||
bd4c625c LT |
414 | /* leaf level */ |
415 | needed_nodes = 1; | |
416 | total_node_size = 0; | |
417 | cur_free = max_node_size; | |
418 | ||
419 | // start from 'from'-th item | |
420 | start_item = from; | |
421 | // skip its first 'start_bytes' units | |
422 | start_bytes = ((from_bytes != -1) ? from_bytes : 0); | |
423 | ||
424 | // last included item is the 'end_item'-th one | |
425 | end_item = vn->vn_nr_item - to - 1; | |
426 | // do not count last 'end_bytes' units of 'end_item'-th item | |
427 | end_bytes = (to_bytes != -1) ? to_bytes : 0; | |
428 | ||
429 | /* go through all item beginning from the start_item-th item and ending by | |
430 | the end_item-th item. Do not count first 'start_bytes' units of | |
431 | 'start_item'-th item and last 'end_bytes' of 'end_item'-th item */ | |
432 | ||
433 | for (i = start_item; i <= end_item; i++) { | |
434 | struct virtual_item *vi = vn->vn_vi + i; | |
435 | int skip_from_end = ((i == end_item) ? end_bytes : 0); | |
436 | ||
437 | RFALSE(needed_nodes > 3, "vs-8105: too many nodes are needed"); | |
438 | ||
439 | /* get size of current item */ | |
440 | current_item_size = vi->vi_item_len; | |
441 | ||
442 | /* do not take in calculation head part (from_bytes) of from-th item */ | |
443 | current_item_size -= | |
444 | op_part_size(vi, 0 /*from start */ , start_bytes); | |
445 | ||
446 | /* do not take in calculation tail part of last item */ | |
447 | current_item_size -= | |
448 | op_part_size(vi, 1 /*from end */ , skip_from_end); | |
449 | ||
450 | /* if item fits into current node entierly */ | |
451 | if (total_node_size + current_item_size <= max_node_size) { | |
452 | snum012[needed_nodes - 1]++; | |
453 | total_node_size += current_item_size; | |
454 | start_bytes = 0; | |
455 | continue; | |
456 | } | |
457 | ||
458 | if (current_item_size > max_node_size) { | |
459 | /* virtual item length is longer, than max size of item in | |
460 | a node. It is impossible for direct item */ | |
461 | RFALSE(is_direct_le_ih(vi->vi_ih), | |
462 | "vs-8110: " | |
463 | "direct item length is %d. It can not be longer than %d", | |
464 | current_item_size, max_node_size); | |
465 | /* we will try to split it */ | |
466 | flow = 1; | |
467 | } | |
468 | ||
469 | if (!flow) { | |
470 | /* as we do not split items, take new node and continue */ | |
471 | needed_nodes++; | |
472 | i--; | |
473 | total_node_size = 0; | |
474 | continue; | |
475 | } | |
476 | // calculate number of item units which fit into node being | |
477 | // filled | |
478 | { | |
479 | int free_space; | |
480 | ||
481 | free_space = max_node_size - total_node_size - IH_SIZE; | |
482 | units = | |
483 | op_check_left(vi, free_space, start_bytes, | |
484 | skip_from_end); | |
485 | if (units == -1) { | |
486 | /* nothing fits into current node, take new node and continue */ | |
487 | needed_nodes++, i--, total_node_size = 0; | |
488 | continue; | |
489 | } | |
490 | } | |
491 | ||
492 | /* something fits into the current node */ | |
493 | //if (snum012[3] != -1 || needed_nodes != 1) | |
494 | // reiserfs_panic (tb->tb_sb, "vs-8115: get_num_ver: too many nodes required"); | |
495 | //snum012[needed_nodes - 1 + 3] = op_unit_num (vi) - start_bytes - units; | |
496 | start_bytes += units; | |
497 | snum012[needed_nodes - 1 + 3] = units; | |
498 | ||
499 | if (needed_nodes > 2) | |
45b03d5e JM |
500 | reiserfs_warning(tb->tb_sb, "vs-8111", |
501 | "split_item_position is out of range"); | |
bd4c625c LT |
502 | snum012[needed_nodes - 1]++; |
503 | split_item_positions[needed_nodes - 1] = i; | |
504 | needed_nodes++; | |
505 | /* continue from the same item with start_bytes != -1 */ | |
506 | start_item = i; | |
507 | i--; | |
508 | total_node_size = 0; | |
1da177e4 LT |
509 | } |
510 | ||
bd4c625c LT |
511 | // sum012[4] (if it is not -1) contains number of units of which |
512 | // are to be in S1new, snum012[3] - to be in S0. They are supposed | |
513 | // to be S1bytes and S2bytes correspondingly, so recalculate | |
514 | if (snum012[4] > 0) { | |
515 | int split_item_num; | |
516 | int bytes_to_r, bytes_to_l; | |
517 | int bytes_to_S1new; | |
518 | ||
519 | split_item_num = split_item_positions[1]; | |
520 | bytes_to_l = | |
521 | ((from == split_item_num | |
522 | && from_bytes != -1) ? from_bytes : 0); | |
523 | bytes_to_r = | |
524 | ((end_item == split_item_num | |
525 | && end_bytes != -1) ? end_bytes : 0); | |
526 | bytes_to_S1new = | |
527 | ((split_item_positions[0] == | |
528 | split_item_positions[1]) ? snum012[3] : 0); | |
529 | ||
530 | // s2bytes | |
531 | snum012[4] = | |
532 | op_unit_num(&vn->vn_vi[split_item_num]) - snum012[4] - | |
533 | bytes_to_r - bytes_to_l - bytes_to_S1new; | |
534 | ||
535 | if (vn->vn_vi[split_item_num].vi_index != TYPE_DIRENTRY && | |
536 | vn->vn_vi[split_item_num].vi_index != TYPE_INDIRECT) | |
45b03d5e JM |
537 | reiserfs_warning(tb->tb_sb, "vs-8115", |
538 | "not directory or indirect item"); | |
1da177e4 LT |
539 | } |
540 | ||
bd4c625c LT |
541 | /* now we know S2bytes, calculate S1bytes */ |
542 | if (snum012[3] > 0) { | |
543 | int split_item_num; | |
544 | int bytes_to_r, bytes_to_l; | |
545 | int bytes_to_S2new; | |
546 | ||
547 | split_item_num = split_item_positions[0]; | |
548 | bytes_to_l = | |
549 | ((from == split_item_num | |
550 | && from_bytes != -1) ? from_bytes : 0); | |
551 | bytes_to_r = | |
552 | ((end_item == split_item_num | |
553 | && end_bytes != -1) ? end_bytes : 0); | |
554 | bytes_to_S2new = | |
555 | ((split_item_positions[0] == split_item_positions[1] | |
556 | && snum012[4] != -1) ? snum012[4] : 0); | |
557 | ||
558 | // s1bytes | |
559 | snum012[3] = | |
560 | op_unit_num(&vn->vn_vi[split_item_num]) - snum012[3] - | |
561 | bytes_to_r - bytes_to_l - bytes_to_S2new; | |
1da177e4 LT |
562 | } |
563 | ||
bd4c625c | 564 | return needed_nodes; |
1da177e4 LT |
565 | } |
566 | ||
1da177e4 | 567 | |
1da177e4 LT |
568 | /* Set parameters for balancing. |
569 | * Performs write of results of analysis of balancing into structure tb, | |
0222e657 | 570 | * where it will later be used by the functions that actually do the balancing. |
1da177e4 LT |
571 | * Parameters: |
572 | * tb tree_balance structure; | |
573 | * h current level of the node; | |
574 | * lnum number of items from S[h] that must be shifted to L[h]; | |
575 | * rnum number of items from S[h] that must be shifted to R[h]; | |
576 | * blk_num number of blocks that S[h] will be splitted into; | |
577 | * s012 number of items that fall into splitted nodes. | |
578 | * lbytes number of bytes which flow to the left neighbor from the item that is not | |
579 | * not shifted entirely | |
580 | * rbytes number of bytes which flow to the right neighbor from the item that is not | |
581 | * not shifted entirely | |
582 | * s1bytes number of bytes which flow to the first new node when S[0] splits (this number is contained in s012 array) | |
583 | */ | |
584 | ||
bd4c625c LT |
585 | static void set_parameters(struct tree_balance *tb, int h, int lnum, |
586 | int rnum, int blk_num, short *s012, int lb, int rb) | |
1da177e4 LT |
587 | { |
588 | ||
bd4c625c LT |
589 | tb->lnum[h] = lnum; |
590 | tb->rnum[h] = rnum; | |
591 | tb->blknum[h] = blk_num; | |
1da177e4 | 592 | |
bd4c625c LT |
593 | if (h == 0) { /* only for leaf level */ |
594 | if (s012 != NULL) { | |
595 | tb->s0num = *s012++, | |
596 | tb->s1num = *s012++, tb->s2num = *s012++; | |
597 | tb->s1bytes = *s012++; | |
598 | tb->s2bytes = *s012; | |
599 | } | |
600 | tb->lbytes = lb; | |
601 | tb->rbytes = rb; | |
1da177e4 | 602 | } |
bd4c625c LT |
603 | PROC_INFO_ADD(tb->tb_sb, lnum[h], lnum); |
604 | PROC_INFO_ADD(tb->tb_sb, rnum[h], rnum); | |
1da177e4 | 605 | |
bd4c625c LT |
606 | PROC_INFO_ADD(tb->tb_sb, lbytes[h], lb); |
607 | PROC_INFO_ADD(tb->tb_sb, rbytes[h], rb); | |
608 | } | |
1da177e4 LT |
609 | |
610 | /* check, does node disappear if we shift tb->lnum[0] items to left | |
611 | neighbor and tb->rnum[0] to the right one. */ | |
bd4c625c | 612 | static int is_leaf_removable(struct tree_balance *tb) |
1da177e4 | 613 | { |
bd4c625c LT |
614 | struct virtual_node *vn = tb->tb_vn; |
615 | int to_left, to_right; | |
616 | int size; | |
617 | int remain_items; | |
618 | ||
619 | /* number of items, that will be shifted to left (right) neighbor | |
620 | entirely */ | |
621 | to_left = tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0); | |
622 | to_right = tb->rnum[0] - ((tb->rbytes != -1) ? 1 : 0); | |
623 | remain_items = vn->vn_nr_item; | |
624 | ||
625 | /* how many items remain in S[0] after shiftings to neighbors */ | |
626 | remain_items -= (to_left + to_right); | |
627 | ||
628 | if (remain_items < 1) { | |
629 | /* all content of node can be shifted to neighbors */ | |
630 | set_parameters(tb, 0, to_left, vn->vn_nr_item - to_left, 0, | |
631 | NULL, -1, -1); | |
632 | return 1; | |
633 | } | |
1da177e4 | 634 | |
bd4c625c LT |
635 | if (remain_items > 1 || tb->lbytes == -1 || tb->rbytes == -1) |
636 | /* S[0] is not removable */ | |
637 | return 0; | |
638 | ||
639 | /* check, whether we can divide 1 remaining item between neighbors */ | |
640 | ||
641 | /* get size of remaining item (in item units) */ | |
642 | size = op_unit_num(&(vn->vn_vi[to_left])); | |
643 | ||
644 | if (tb->lbytes + tb->rbytes >= size) { | |
645 | set_parameters(tb, 0, to_left + 1, to_right + 1, 0, NULL, | |
646 | tb->lbytes, -1); | |
647 | return 1; | |
648 | } | |
649 | ||
650 | return 0; | |
651 | } | |
1da177e4 LT |
652 | |
653 | /* check whether L, S, R can be joined in one node */ | |
bd4c625c | 654 | static int are_leaves_removable(struct tree_balance *tb, int lfree, int rfree) |
1da177e4 | 655 | { |
bd4c625c LT |
656 | struct virtual_node *vn = tb->tb_vn; |
657 | int ih_size; | |
658 | struct buffer_head *S0; | |
659 | ||
660 | S0 = PATH_H_PBUFFER(tb->tb_path, 0); | |
661 | ||
662 | ih_size = 0; | |
663 | if (vn->vn_nr_item) { | |
664 | if (vn->vn_vi[0].vi_type & VI_TYPE_LEFT_MERGEABLE) | |
665 | ih_size += IH_SIZE; | |
666 | ||
667 | if (vn->vn_vi[vn->vn_nr_item - 1]. | |
668 | vi_type & VI_TYPE_RIGHT_MERGEABLE) | |
669 | ih_size += IH_SIZE; | |
670 | } else { | |
671 | /* there was only one item and it will be deleted */ | |
672 | struct item_head *ih; | |
673 | ||
674 | RFALSE(B_NR_ITEMS(S0) != 1, | |
675 | "vs-8125: item number must be 1: it is %d", | |
676 | B_NR_ITEMS(S0)); | |
677 | ||
678 | ih = B_N_PITEM_HEAD(S0, 0); | |
679 | if (tb->CFR[0] | |
680 | && !comp_short_le_keys(&(ih->ih_key), | |
681 | B_N_PDELIM_KEY(tb->CFR[0], | |
682 | tb->rkey[0]))) | |
683 | if (is_direntry_le_ih(ih)) { | |
684 | /* Directory must be in correct state here: that is | |
685 | somewhere at the left side should exist first directory | |
686 | item. But the item being deleted can not be that first | |
687 | one because its right neighbor is item of the same | |
688 | directory. (But first item always gets deleted in last | |
689 | turn). So, neighbors of deleted item can be merged, so | |
690 | we can save ih_size */ | |
691 | ih_size = IH_SIZE; | |
692 | ||
693 | /* we might check that left neighbor exists and is of the | |
694 | same directory */ | |
695 | RFALSE(le_ih_k_offset(ih) == DOT_OFFSET, | |
696 | "vs-8130: first directory item can not be removed until directory is not empty"); | |
697 | } | |
1da177e4 | 698 | |
bd4c625c LT |
699 | } |
700 | ||
701 | if (MAX_CHILD_SIZE(S0) + vn->vn_size <= rfree + lfree + ih_size) { | |
702 | set_parameters(tb, 0, -1, -1, -1, NULL, -1, -1); | |
703 | PROC_INFO_INC(tb->tb_sb, leaves_removable); | |
704 | return 1; | |
705 | } | |
706 | return 0; | |
1da177e4 | 707 | |
bd4c625c | 708 | } |
1da177e4 LT |
709 | |
710 | /* when we do not split item, lnum and rnum are numbers of entire items */ | |
711 | #define SET_PAR_SHIFT_LEFT \ | |
712 | if (h)\ | |
713 | {\ | |
714 | int to_l;\ | |
715 | \ | |
716 | to_l = (MAX_NR_KEY(Sh)+1 - lpar + vn->vn_nr_item + 1) / 2 -\ | |
717 | (MAX_NR_KEY(Sh) + 1 - lpar);\ | |
718 | \ | |
719 | set_parameters (tb, h, to_l, 0, lnver, NULL, -1, -1);\ | |
720 | }\ | |
721 | else \ | |
722 | {\ | |
723 | if (lset==LEFT_SHIFT_FLOW)\ | |
724 | set_parameters (tb, h, lpar, 0, lnver, snum012+lset,\ | |
725 | tb->lbytes, -1);\ | |
726 | else\ | |
727 | set_parameters (tb, h, lpar - (tb->lbytes!=-1), 0, lnver, snum012+lset,\ | |
728 | -1, -1);\ | |
729 | } | |
730 | ||
1da177e4 LT |
731 | #define SET_PAR_SHIFT_RIGHT \ |
732 | if (h)\ | |
733 | {\ | |
734 | int to_r;\ | |
735 | \ | |
736 | to_r = (MAX_NR_KEY(Sh)+1 - rpar + vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - rpar);\ | |
737 | \ | |
738 | set_parameters (tb, h, 0, to_r, rnver, NULL, -1, -1);\ | |
739 | }\ | |
740 | else \ | |
741 | {\ | |
742 | if (rset==RIGHT_SHIFT_FLOW)\ | |
743 | set_parameters (tb, h, 0, rpar, rnver, snum012+rset,\ | |
744 | -1, tb->rbytes);\ | |
745 | else\ | |
746 | set_parameters (tb, h, 0, rpar - (tb->rbytes!=-1), rnver, snum012+rset,\ | |
747 | -1, -1);\ | |
748 | } | |
749 | ||
a063ae17 | 750 | static void free_buffers_in_tb(struct tree_balance *tb) |
bd4c625c | 751 | { |
ee93961b | 752 | int i; |
bd4c625c | 753 | |
a063ae17 | 754 | pathrelse(tb->tb_path); |
bd4c625c | 755 | |
ee93961b JM |
756 | for (i = 0; i < MAX_HEIGHT; i++) { |
757 | brelse(tb->L[i]); | |
758 | brelse(tb->R[i]); | |
759 | brelse(tb->FL[i]); | |
760 | brelse(tb->FR[i]); | |
761 | brelse(tb->CFL[i]); | |
762 | brelse(tb->CFR[i]); | |
763 | ||
764 | tb->L[i] = NULL; | |
765 | tb->R[i] = NULL; | |
766 | tb->FL[i] = NULL; | |
767 | tb->FR[i] = NULL; | |
768 | tb->CFL[i] = NULL; | |
769 | tb->CFR[i] = NULL; | |
bd4c625c | 770 | } |
1da177e4 LT |
771 | } |
772 | ||
1da177e4 LT |
773 | /* Get new buffers for storing new nodes that are created while balancing. |
774 | * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; | |
775 | * CARRY_ON - schedule didn't occur while the function worked; | |
776 | * NO_DISK_SPACE - no disk space. | |
777 | */ | |
778 | /* The function is NOT SCHEDULE-SAFE! */ | |
ee93961b | 779 | static int get_empty_nodes(struct tree_balance *tb, int h) |
bd4c625c | 780 | { |
d68caa95 | 781 | struct buffer_head *new_bh, |
ee93961b JM |
782 | *Sh = PATH_H_PBUFFER(tb->tb_path, h); |
783 | b_blocknr_t *blocknr, blocknrs[MAX_AMOUNT_NEEDED] = { 0, }; | |
784 | int counter, number_of_freeblk, amount_needed, /* number of needed empty blocks */ | |
785 | retval = CARRY_ON; | |
a063ae17 | 786 | struct super_block *sb = tb->tb_sb; |
bd4c625c LT |
787 | |
788 | /* number_of_freeblk is the number of empty blocks which have been | |
789 | acquired for use by the balancing algorithm minus the number of | |
790 | empty blocks used in the previous levels of the analysis, | |
791 | number_of_freeblk = tb->cur_blknum can be non-zero if a schedule occurs | |
792 | after empty blocks are acquired, and the balancing analysis is | |
793 | then restarted, amount_needed is the number needed by this level | |
ee93961b | 794 | (h) of the balancing analysis. |
bd4c625c LT |
795 | |
796 | Note that for systems with many processes writing, it would be | |
797 | more layout optimal to calculate the total number needed by all | |
798 | levels and then to run reiserfs_new_blocks to get all of them at once. */ | |
799 | ||
800 | /* Initiate number_of_freeblk to the amount acquired prior to the restart of | |
801 | the analysis or 0 if not restarted, then subtract the amount needed | |
ee93961b JM |
802 | by all of the levels of the tree below h. */ |
803 | /* blknum includes S[h], so we subtract 1 in this calculation */ | |
804 | for (counter = 0, number_of_freeblk = tb->cur_blknum; | |
805 | counter < h; counter++) | |
806 | number_of_freeblk -= | |
807 | (tb->blknum[counter]) ? (tb->blknum[counter] - | |
bd4c625c LT |
808 | 1) : 0; |
809 | ||
810 | /* Allocate missing empty blocks. */ | |
d68caa95 | 811 | /* if Sh == 0 then we are getting a new root */ |
ee93961b | 812 | amount_needed = (Sh) ? (tb->blknum[h] - 1) : 1; |
bd4c625c | 813 | /* Amount_needed = the amount that we need more than the amount that we have. */ |
ee93961b JM |
814 | if (amount_needed > number_of_freeblk) |
815 | amount_needed -= number_of_freeblk; | |
bd4c625c LT |
816 | else /* If we have enough already then there is nothing to do. */ |
817 | return CARRY_ON; | |
818 | ||
819 | /* No need to check quota - is not allocated for blocks used for formatted nodes */ | |
ee93961b JM |
820 | if (reiserfs_new_form_blocknrs(tb, blocknrs, |
821 | amount_needed) == NO_DISK_SPACE) | |
bd4c625c LT |
822 | return NO_DISK_SPACE; |
823 | ||
824 | /* for each blocknumber we just got, get a buffer and stick it on FEB */ | |
ee93961b JM |
825 | for (blocknr = blocknrs, counter = 0; |
826 | counter < amount_needed; blocknr++, counter++) { | |
bd4c625c | 827 | |
d68caa95 | 828 | RFALSE(!*blocknr, |
bd4c625c LT |
829 | "PAP-8135: reiserfs_new_blocknrs failed when got new blocks"); |
830 | ||
d68caa95 JM |
831 | new_bh = sb_getblk(sb, *blocknr); |
832 | RFALSE(buffer_dirty(new_bh) || | |
833 | buffer_journaled(new_bh) || | |
834 | buffer_journal_dirty(new_bh), | |
febe29d9 | 835 | "PAP-8140: journaled or dirty buffer %b for the new block", |
d68caa95 | 836 | new_bh); |
bd4c625c LT |
837 | |
838 | /* Put empty buffers into the array. */ | |
a063ae17 | 839 | RFALSE(tb->FEB[tb->cur_blknum], |
bd4c625c LT |
840 | "PAP-8141: busy slot for new buffer"); |
841 | ||
d68caa95 JM |
842 | set_buffer_journal_new(new_bh); |
843 | tb->FEB[tb->cur_blknum++] = new_bh; | |
bd4c625c LT |
844 | } |
845 | ||
ee93961b JM |
846 | if (retval == CARRY_ON && FILESYSTEM_CHANGED_TB(tb)) |
847 | retval = REPEAT_SEARCH; | |
1da177e4 | 848 | |
ee93961b | 849 | return retval; |
bd4c625c | 850 | } |
1da177e4 LT |
851 | |
852 | /* Get free space of the left neighbor, which is stored in the parent | |
853 | * node of the left neighbor. */ | |
bd4c625c | 854 | static int get_lfree(struct tree_balance *tb, int h) |
1da177e4 | 855 | { |
bd4c625c LT |
856 | struct buffer_head *l, *f; |
857 | int order; | |
1da177e4 | 858 | |
9dce07f1 AV |
859 | if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL || |
860 | (l = tb->FL[h]) == NULL) | |
bd4c625c | 861 | return 0; |
1da177e4 | 862 | |
bd4c625c LT |
863 | if (f == l) |
864 | order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) - 1; | |
865 | else { | |
866 | order = B_NR_ITEMS(l); | |
867 | f = l; | |
868 | } | |
1da177e4 | 869 | |
bd4c625c | 870 | return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order))); |
1da177e4 LT |
871 | } |
872 | ||
1da177e4 LT |
873 | /* Get free space of the right neighbor, |
874 | * which is stored in the parent node of the right neighbor. | |
875 | */ | |
bd4c625c | 876 | static int get_rfree(struct tree_balance *tb, int h) |
1da177e4 | 877 | { |
bd4c625c LT |
878 | struct buffer_head *r, *f; |
879 | int order; | |
1da177e4 | 880 | |
9dce07f1 AV |
881 | if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL || |
882 | (r = tb->FR[h]) == NULL) | |
bd4c625c | 883 | return 0; |
1da177e4 | 884 | |
bd4c625c LT |
885 | if (f == r) |
886 | order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) + 1; | |
887 | else { | |
888 | order = 0; | |
889 | f = r; | |
890 | } | |
1da177e4 | 891 | |
bd4c625c | 892 | return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order))); |
1da177e4 LT |
893 | |
894 | } | |
895 | ||
1da177e4 | 896 | /* Check whether left neighbor is in memory. */ |
ee93961b | 897 | static int is_left_neighbor_in_cache(struct tree_balance *tb, int h) |
bd4c625c | 898 | { |
d68caa95 | 899 | struct buffer_head *father, *left; |
a063ae17 | 900 | struct super_block *sb = tb->tb_sb; |
ee93961b JM |
901 | b_blocknr_t left_neighbor_blocknr; |
902 | int left_neighbor_position; | |
bd4c625c | 903 | |
a063ae17 | 904 | /* Father of the left neighbor does not exist. */ |
ee93961b | 905 | if (!tb->FL[h]) |
bd4c625c LT |
906 | return 0; |
907 | ||
908 | /* Calculate father of the node to be balanced. */ | |
ee93961b | 909 | father = PATH_H_PBUFFER(tb->tb_path, h + 1); |
bd4c625c | 910 | |
d68caa95 JM |
911 | RFALSE(!father || |
912 | !B_IS_IN_TREE(father) || | |
ee93961b | 913 | !B_IS_IN_TREE(tb->FL[h]) || |
d68caa95 | 914 | !buffer_uptodate(father) || |
ee93961b | 915 | !buffer_uptodate(tb->FL[h]), |
bd4c625c | 916 | "vs-8165: F[h] (%b) or FL[h] (%b) is invalid", |
ee93961b | 917 | father, tb->FL[h]); |
bd4c625c LT |
918 | |
919 | /* Get position of the pointer to the left neighbor into the left father. */ | |
ee93961b JM |
920 | left_neighbor_position = (father == tb->FL[h]) ? |
921 | tb->lkey[h] : B_NR_ITEMS(tb->FL[h]); | |
bd4c625c | 922 | /* Get left neighbor block number. */ |
ee93961b JM |
923 | left_neighbor_blocknr = |
924 | B_N_CHILD_NUM(tb->FL[h], left_neighbor_position); | |
bd4c625c | 925 | /* Look for the left neighbor in the cache. */ |
ee93961b | 926 | if ((left = sb_find_get_block(sb, left_neighbor_blocknr))) { |
bd4c625c LT |
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 | ||
d68caa95 | 941 | static void decrement_key(struct cpu_key *key) |
1da177e4 | 942 | { |
bd4c625c | 943 | // call item specific function for this key |
d68caa95 | 944 | item_ops[cpu_key_k_type(key)]->decrement_key(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 | */ | |
a063ae17 | 955 | static int get_far_parent(struct tree_balance *tb, |
ee93961b | 956 | int h, |
d68caa95 JM |
957 | struct buffer_head **pfather, |
958 | struct buffer_head **pcom_father, char c_lr_par) | |
1da177e4 | 959 | { |
d68caa95 | 960 | struct buffer_head *parent; |
bd4c625c | 961 | INITIALIZE_PATH(s_path_to_neighbor_father); |
d68caa95 | 962 | struct treepath *path = tb->tb_path; |
bd4c625c | 963 | struct cpu_key s_lr_father_key; |
ee93961b JM |
964 | int counter, |
965 | position = INT_MAX, | |
966 | first_last_position = 0, | |
967 | path_offset = PATH_H_PATH_OFFSET(path, h); | |
bd4c625c | 968 | |
ee93961b JM |
969 | /* Starting from F[h] go upwards in the tree, and look for the common |
970 | ancestor of F[h], and its neighbor l/r, that should be obtained. */ | |
bd4c625c | 971 | |
ee93961b | 972 | counter = path_offset; |
bd4c625c | 973 | |
ee93961b | 974 | RFALSE(counter < FIRST_PATH_ELEMENT_OFFSET, |
bd4c625c LT |
975 | "PAP-8180: invalid path length"); |
976 | ||
ee93961b | 977 | for (; counter > FIRST_PATH_ELEMENT_OFFSET; counter--) { |
bd4c625c LT |
978 | /* Check whether parent of the current buffer in the path is really parent in the tree. */ |
979 | if (!B_IS_IN_TREE | |
ee93961b | 980 | (parent = PATH_OFFSET_PBUFFER(path, counter - 1))) |
bd4c625c LT |
981 | return REPEAT_SEARCH; |
982 | /* Check whether position in the parent is correct. */ | |
ee93961b | 983 | if ((position = |
d68caa95 | 984 | PATH_OFFSET_POSITION(path, |
ee93961b | 985 | counter - 1)) > |
d68caa95 | 986 | B_NR_ITEMS(parent)) |
bd4c625c LT |
987 | return REPEAT_SEARCH; |
988 | /* Check whether parent at the path really points to the child. */ | |
ee93961b JM |
989 | if (B_N_CHILD_NUM(parent, position) != |
990 | PATH_OFFSET_PBUFFER(path, counter)->b_blocknr) | |
bd4c625c LT |
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) | |
ee93961b JM |
994 | first_last_position = B_NR_ITEMS(parent); |
995 | if (position != first_last_position) { | |
d68caa95 JM |
996 | *pcom_father = parent; |
997 | get_bh(*pcom_father); | |
998 | /*(*pcom_father = parent)->b_count++; */ | |
bd4c625c LT |
999 | break; |
1000 | } | |
1da177e4 | 1001 | } |
bd4c625c LT |
1002 | |
1003 | /* if we are in the root of the tree, then there is no common father */ | |
ee93961b | 1004 | if (counter == FIRST_PATH_ELEMENT_OFFSET) { |
bd4c625c LT |
1005 | /* Check whether first buffer in the path is the root of the tree. */ |
1006 | if (PATH_OFFSET_PBUFFER | |
a063ae17 | 1007 | (tb->tb_path, |
bd4c625c | 1008 | FIRST_PATH_ELEMENT_OFFSET)->b_blocknr == |
a063ae17 | 1009 | SB_ROOT_BLOCK(tb->tb_sb)) { |
d68caa95 | 1010 | *pfather = *pcom_father = NULL; |
bd4c625c LT |
1011 | return CARRY_ON; |
1012 | } | |
1013 | return REPEAT_SEARCH; | |
1da177e4 | 1014 | } |
1da177e4 | 1015 | |
d68caa95 | 1016 | RFALSE(B_LEVEL(*pcom_father) <= DISK_LEAF_NODE_LEVEL, |
bd4c625c | 1017 | "PAP-8185: (%b %z) level too small", |
d68caa95 | 1018 | *pcom_father, *pcom_father); |
1da177e4 | 1019 | |
bd4c625c | 1020 | /* Check whether the common parent is locked. */ |
1da177e4 | 1021 | |
d68caa95 | 1022 | if (buffer_locked(*pcom_father)) { |
8ebc4232 FW |
1023 | |
1024 | /* Release the write lock while the buffer is busy */ | |
278f6679 | 1025 | int depth = reiserfs_write_unlock_nested(tb->tb_sb); |
d68caa95 | 1026 | __wait_on_buffer(*pcom_father); |
278f6679 | 1027 | reiserfs_write_lock_nested(tb->tb_sb, depth); |
a063ae17 | 1028 | if (FILESYSTEM_CHANGED_TB(tb)) { |
d68caa95 | 1029 | brelse(*pcom_father); |
bd4c625c LT |
1030 | return REPEAT_SEARCH; |
1031 | } | |
1da177e4 | 1032 | } |
1da177e4 | 1033 | |
bd4c625c LT |
1034 | /* So, we got common parent of the current node and its left/right neighbor. |
1035 | Now we are geting the parent of the left/right neighbor. */ | |
1da177e4 | 1036 | |
bd4c625c LT |
1037 | /* Form key to get parent of the left/right neighbor. */ |
1038 | le_key2cpu_key(&s_lr_father_key, | |
d68caa95 | 1039 | B_N_PDELIM_KEY(*pcom_father, |
bd4c625c | 1040 | (c_lr_par == |
ee93961b JM |
1041 | LEFT_PARENTS) ? (tb->lkey[h - 1] = |
1042 | position - | |
1043 | 1) : (tb->rkey[h - | |
bd4c625c | 1044 | 1] = |
ee93961b | 1045 | position))); |
1da177e4 | 1046 | |
bd4c625c LT |
1047 | if (c_lr_par == LEFT_PARENTS) |
1048 | decrement_key(&s_lr_father_key); | |
1da177e4 | 1049 | |
bd4c625c | 1050 | if (search_by_key |
a063ae17 | 1051 | (tb->tb_sb, &s_lr_father_key, &s_path_to_neighbor_father, |
ee93961b | 1052 | h + 1) == IO_ERROR) |
bd4c625c LT |
1053 | // path is released |
1054 | return IO_ERROR; | |
1da177e4 | 1055 | |
a063ae17 | 1056 | if (FILESYSTEM_CHANGED_TB(tb)) { |
3cd6dbe6 | 1057 | pathrelse(&s_path_to_neighbor_father); |
d68caa95 | 1058 | brelse(*pcom_father); |
bd4c625c LT |
1059 | return REPEAT_SEARCH; |
1060 | } | |
1da177e4 | 1061 | |
d68caa95 | 1062 | *pfather = PATH_PLAST_BUFFER(&s_path_to_neighbor_father); |
1da177e4 | 1063 | |
ee93961b | 1064 | RFALSE(B_LEVEL(*pfather) != h + 1, |
d68caa95 | 1065 | "PAP-8190: (%b %z) level too small", *pfather, *pfather); |
bd4c625c LT |
1066 | RFALSE(s_path_to_neighbor_father.path_length < |
1067 | FIRST_PATH_ELEMENT_OFFSET, "PAP-8192: path length is too small"); | |
1da177e4 | 1068 | |
bd4c625c | 1069 | s_path_to_neighbor_father.path_length--; |
3cd6dbe6 | 1070 | pathrelse(&s_path_to_neighbor_father); |
bd4c625c | 1071 | return CARRY_ON; |
1da177e4 LT |
1072 | } |
1073 | ||
ee93961b JM |
1074 | /* Get parents of neighbors of node in the path(S[path_offset]) and common parents of |
1075 | * S[path_offset] and L[path_offset]/R[path_offset]: F[path_offset], FL[path_offset], | |
1076 | * FR[path_offset], CFL[path_offset], CFR[path_offset]. | |
1077 | * Calculate numbers of left and right delimiting keys position: lkey[path_offset], rkey[path_offset]. | |
1da177e4 LT |
1078 | * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; |
1079 | * CARRY_ON - schedule didn't occur while the function worked; | |
1080 | */ | |
ee93961b | 1081 | static int get_parents(struct tree_balance *tb, int h) |
1da177e4 | 1082 | { |
d68caa95 | 1083 | struct treepath *path = tb->tb_path; |
ee93961b JM |
1084 | int position, |
1085 | ret, | |
1086 | path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h); | |
d68caa95 | 1087 | struct buffer_head *curf, *curcf; |
bd4c625c LT |
1088 | |
1089 | /* Current node is the root of the tree or will be root of the tree */ | |
ee93961b | 1090 | if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) { |
bd4c625c LT |
1091 | /* The root can not have parents. |
1092 | Release nodes which previously were obtained as parents of the current node neighbors. */ | |
ee93961b JM |
1093 | brelse(tb->FL[h]); |
1094 | brelse(tb->CFL[h]); | |
1095 | brelse(tb->FR[h]); | |
1096 | brelse(tb->CFR[h]); | |
1097 | tb->FL[h] = NULL; | |
1098 | tb->CFL[h] = NULL; | |
1099 | tb->FR[h] = NULL; | |
1100 | tb->CFR[h] = NULL; | |
bd4c625c LT |
1101 | return CARRY_ON; |
1102 | } | |
1103 | ||
ee93961b JM |
1104 | /* Get parent FL[path_offset] of L[path_offset]. */ |
1105 | position = PATH_OFFSET_POSITION(path, path_offset - 1); | |
1106 | if (position) { | |
bd4c625c | 1107 | /* Current node is not the first child of its parent. */ |
ee93961b JM |
1108 | curf = PATH_OFFSET_PBUFFER(path, path_offset - 1); |
1109 | curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1); | |
d68caa95 JM |
1110 | get_bh(curf); |
1111 | get_bh(curf); | |
ee93961b | 1112 | tb->lkey[h] = position - 1; |
bd4c625c | 1113 | } else { |
ee93961b JM |
1114 | /* Calculate current parent of L[path_offset], which is the left neighbor of the current node. |
1115 | Calculate current common parent of L[path_offset] and the current node. Note that | |
1116 | CFL[path_offset] not equal FL[path_offset] and CFL[path_offset] not equal F[path_offset]. | |
1117 | Calculate lkey[path_offset]. */ | |
1118 | if ((ret = get_far_parent(tb, h + 1, &curf, | |
d68caa95 | 1119 | &curcf, |
bd4c625c | 1120 | LEFT_PARENTS)) != CARRY_ON) |
ee93961b | 1121 | return ret; |
bd4c625c LT |
1122 | } |
1123 | ||
ee93961b JM |
1124 | brelse(tb->FL[h]); |
1125 | tb->FL[h] = curf; /* New initialization of FL[h]. */ | |
1126 | brelse(tb->CFL[h]); | |
1127 | tb->CFL[h] = curcf; /* New initialization of CFL[h]. */ | |
bd4c625c | 1128 | |
d68caa95 JM |
1129 | RFALSE((curf && !B_IS_IN_TREE(curf)) || |
1130 | (curcf && !B_IS_IN_TREE(curcf)), | |
1131 | "PAP-8195: FL (%b) or CFL (%b) is invalid", curf, curcf); | |
1da177e4 | 1132 | |
ee93961b | 1133 | /* Get parent FR[h] of R[h]. */ |
1da177e4 | 1134 | |
ee93961b JM |
1135 | /* Current node is the last child of F[h]. FR[h] != F[h]. */ |
1136 | if (position == B_NR_ITEMS(PATH_H_PBUFFER(path, h + 1))) { | |
1137 | /* Calculate current parent of R[h], which is the right neighbor of F[h]. | |
1138 | Calculate current common parent of R[h] and current node. Note that CFR[h] | |
1139 | not equal FR[path_offset] and CFR[h] not equal F[h]. */ | |
1140 | if ((ret = | |
1141 | get_far_parent(tb, h + 1, &curf, &curcf, | |
bd4c625c | 1142 | RIGHT_PARENTS)) != CARRY_ON) |
ee93961b | 1143 | return ret; |
bd4c625c | 1144 | } else { |
ee93961b JM |
1145 | /* Current node is not the last child of its parent F[h]. */ |
1146 | curf = PATH_OFFSET_PBUFFER(path, path_offset - 1); | |
1147 | curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1); | |
d68caa95 JM |
1148 | get_bh(curf); |
1149 | get_bh(curf); | |
ee93961b | 1150 | tb->rkey[h] = position; |
bd4c625c | 1151 | } |
1da177e4 | 1152 | |
ee93961b JM |
1153 | brelse(tb->FR[h]); |
1154 | /* New initialization of FR[path_offset]. */ | |
1155 | tb->FR[h] = curf; | |
bd4c625c | 1156 | |
ee93961b JM |
1157 | brelse(tb->CFR[h]); |
1158 | /* New initialization of CFR[path_offset]. */ | |
1159 | tb->CFR[h] = curcf; | |
bd4c625c | 1160 | |
d68caa95 JM |
1161 | RFALSE((curf && !B_IS_IN_TREE(curf)) || |
1162 | (curcf && !B_IS_IN_TREE(curcf)), | |
1163 | "PAP-8205: FR (%b) or CFR (%b) is invalid", curf, curcf); | |
bd4c625c LT |
1164 | |
1165 | return CARRY_ON; | |
1166 | } | |
1da177e4 LT |
1167 | |
1168 | /* it is possible to remove node as result of shiftings to | |
1169 | neighbors even when we insert or paste item. */ | |
bd4c625c LT |
1170 | static inline int can_node_be_removed(int mode, int lfree, int sfree, int rfree, |
1171 | struct tree_balance *tb, int h) | |
1da177e4 | 1172 | { |
bd4c625c LT |
1173 | struct buffer_head *Sh = PATH_H_PBUFFER(tb->tb_path, h); |
1174 | int levbytes = tb->insert_size[h]; | |
1175 | struct item_head *ih; | |
1176 | struct reiserfs_key *r_key = NULL; | |
1177 | ||
1178 | ih = B_N_PITEM_HEAD(Sh, 0); | |
1179 | if (tb->CFR[h]) | |
1180 | r_key = B_N_PDELIM_KEY(tb->CFR[h], tb->rkey[h]); | |
1181 | ||
1182 | if (lfree + rfree + sfree < MAX_CHILD_SIZE(Sh) + levbytes | |
1183 | /* shifting may merge items which might save space */ | |
1184 | - | |
1185 | ((!h | |
1186 | && op_is_left_mergeable(&(ih->ih_key), Sh->b_size)) ? IH_SIZE : 0) | |
1187 | - | |
1188 | ((!h && r_key | |
1189 | && op_is_left_mergeable(r_key, Sh->b_size)) ? IH_SIZE : 0) | |
1190 | + ((h) ? KEY_SIZE : 0)) { | |
1191 | /* node can not be removed */ | |
1192 | if (sfree >= levbytes) { /* new item fits into node S[h] without any shifting */ | |
1193 | if (!h) | |
1194 | tb->s0num = | |
1195 | B_NR_ITEMS(Sh) + | |
1196 | ((mode == M_INSERT) ? 1 : 0); | |
1197 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1198 | return NO_BALANCING_NEEDED; | |
1199 | } | |
1da177e4 | 1200 | } |
bd4c625c LT |
1201 | PROC_INFO_INC(tb->tb_sb, can_node_be_removed[h]); |
1202 | return !NO_BALANCING_NEEDED; | |
1da177e4 LT |
1203 | } |
1204 | ||
1da177e4 LT |
1205 | /* Check whether current node S[h] is balanced when increasing its size by |
1206 | * Inserting or Pasting. | |
1207 | * Calculate parameters for balancing for current level h. | |
1208 | * Parameters: | |
1209 | * tb tree_balance structure; | |
1210 | * h current level of the node; | |
1211 | * inum item number in S[h]; | |
1212 | * mode i - insert, p - paste; | |
0222e657 | 1213 | * Returns: 1 - schedule occurred; |
1da177e4 LT |
1214 | * 0 - balancing for higher levels needed; |
1215 | * -1 - no balancing for higher levels needed; | |
1216 | * -2 - no disk space. | |
1217 | */ | |
1218 | /* ip means Inserting or Pasting */ | |
bd4c625c | 1219 | static int ip_check_balance(struct tree_balance *tb, int h) |
1da177e4 | 1220 | { |
bd4c625c LT |
1221 | struct virtual_node *vn = tb->tb_vn; |
1222 | int levbytes, /* Number of bytes that must be inserted into (value | |
1223 | is negative if bytes are deleted) buffer which | |
1224 | contains node being balanced. The mnemonic is | |
1225 | that the attempted change in node space used level | |
1226 | is levbytes bytes. */ | |
ee93961b | 1227 | ret; |
bd4c625c LT |
1228 | |
1229 | int lfree, sfree, rfree /* free space in L, S and R */ ; | |
1230 | ||
1231 | /* nver is short for number of vertixes, and lnver is the number if | |
1232 | we shift to the left, rnver is the number if we shift to the | |
1233 | right, and lrnver is the number if we shift in both directions. | |
1234 | The goal is to minimize first the number of vertixes, and second, | |
1235 | the number of vertixes whose contents are changed by shifting, | |
1236 | and third the number of uncached vertixes whose contents are | |
1237 | changed by shifting and must be read from disk. */ | |
1238 | int nver, lnver, rnver, lrnver; | |
1239 | ||
1240 | /* used at leaf level only, S0 = S[0] is the node being balanced, | |
1241 | sInum [ I = 0,1,2 ] is the number of items that will | |
1242 | remain in node SI after balancing. S1 and S2 are new | |
1243 | nodes that might be created. */ | |
1244 | ||
1245 | /* we perform 8 calls to get_num_ver(). For each call we calculate five parameters. | |
1246 | where 4th parameter is s1bytes and 5th - s2bytes | |
1247 | */ | |
0222e657 | 1248 | short snum012[40] = { 0, }; /* s0num, s1num, s2num for 8 cases |
bd4c625c LT |
1249 | 0,1 - do not shift and do not shift but bottle |
1250 | 2 - shift only whole item to left | |
1251 | 3 - shift to left and bottle as much as possible | |
1252 | 4,5 - shift to right (whole items and as much as possible | |
1253 | 6,7 - shift to both directions (whole items and as much as possible) | |
1254 | */ | |
1255 | ||
1256 | /* Sh is the node whose balance is currently being checked */ | |
1257 | struct buffer_head *Sh; | |
1258 | ||
1259 | Sh = PATH_H_PBUFFER(tb->tb_path, h); | |
1260 | levbytes = tb->insert_size[h]; | |
1261 | ||
1262 | /* Calculate balance parameters for creating new root. */ | |
1263 | if (!Sh) { | |
1264 | if (!h) | |
c3a9c210 JM |
1265 | reiserfs_panic(tb->tb_sb, "vs-8210", |
1266 | "S[0] can not be 0"); | |
ee93961b | 1267 | switch (ret = get_empty_nodes(tb, h)) { |
bd4c625c LT |
1268 | case CARRY_ON: |
1269 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1270 | return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ | |
1271 | ||
1272 | case NO_DISK_SPACE: | |
1273 | case REPEAT_SEARCH: | |
ee93961b | 1274 | return ret; |
bd4c625c | 1275 | default: |
c3a9c210 JM |
1276 | reiserfs_panic(tb->tb_sb, "vs-8215", "incorrect " |
1277 | "return value of get_empty_nodes"); | |
bd4c625c | 1278 | } |
1da177e4 | 1279 | } |
1da177e4 | 1280 | |
ee93961b JM |
1281 | if ((ret = get_parents(tb, h)) != CARRY_ON) /* get parents of S[h] neighbors. */ |
1282 | return ret; | |
1da177e4 | 1283 | |
bd4c625c LT |
1284 | sfree = B_FREE_SPACE(Sh); |
1285 | ||
1286 | /* get free space of neighbors */ | |
1287 | rfree = get_rfree(tb, h); | |
1288 | lfree = get_lfree(tb, h); | |
1289 | ||
1290 | if (can_node_be_removed(vn->vn_mode, lfree, sfree, rfree, tb, h) == | |
1291 | NO_BALANCING_NEEDED) | |
1292 | /* and new item fits into node S[h] without any shifting */ | |
1293 | return NO_BALANCING_NEEDED; | |
1da177e4 | 1294 | |
bd4c625c | 1295 | create_virtual_node(tb, h); |
1da177e4 | 1296 | |
0222e657 | 1297 | /* |
bd4c625c LT |
1298 | determine maximal number of items we can shift to the left neighbor (in tb structure) |
1299 | and the maximal number of bytes that can flow to the left neighbor | |
1300 | from the left most liquid item that cannot be shifted from S[0] entirely (returned value) | |
1da177e4 | 1301 | */ |
bd4c625c | 1302 | check_left(tb, h, lfree); |
1da177e4 | 1303 | |
bd4c625c LT |
1304 | /* |
1305 | determine maximal number of items we can shift to the right neighbor (in tb structure) | |
1306 | and the maximal number of bytes that can flow to the right neighbor | |
1307 | from the right most liquid item that cannot be shifted from S[0] entirely (returned value) | |
1308 | */ | |
1309 | check_right(tb, h, rfree); | |
1310 | ||
1311 | /* all contents of internal node S[h] can be moved into its | |
1312 | neighbors, S[h] will be removed after balancing */ | |
1313 | if (h && (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1)) { | |
1314 | int to_r; | |
1315 | ||
1316 | /* Since we are working on internal nodes, and our internal | |
1317 | nodes have fixed size entries, then we can balance by the | |
1318 | number of items rather than the space they consume. In this | |
1319 | routine we set the left node equal to the right node, | |
1320 | allowing a difference of less than or equal to 1 child | |
1321 | pointer. */ | |
1322 | to_r = | |
1323 | ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] + | |
1324 | vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - | |
1325 | tb->rnum[h]); | |
1326 | set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL, | |
1327 | -1, -1); | |
1328 | return CARRY_ON; | |
1329 | } | |
1330 | ||
1331 | /* this checks balance condition, that any two neighboring nodes can not fit in one node */ | |
1332 | RFALSE(h && | |
1333 | (tb->lnum[h] >= vn->vn_nr_item + 1 || | |
1334 | tb->rnum[h] >= vn->vn_nr_item + 1), | |
1335 | "vs-8220: tree is not balanced on internal level"); | |
1336 | RFALSE(!h && ((tb->lnum[h] >= vn->vn_nr_item && (tb->lbytes == -1)) || | |
1337 | (tb->rnum[h] >= vn->vn_nr_item && (tb->rbytes == -1))), | |
1338 | "vs-8225: tree is not balanced on leaf level"); | |
1339 | ||
1340 | /* all contents of S[0] can be moved into its neighbors | |
1341 | S[0] will be removed after balancing. */ | |
1342 | if (!h && is_leaf_removable(tb)) | |
1343 | return CARRY_ON; | |
1344 | ||
1345 | /* why do we perform this check here rather than earlier?? | |
1346 | Answer: we can win 1 node in some cases above. Moreover we | |
1347 | checked it above, when we checked, that S[0] is not removable | |
1348 | in principle */ | |
1349 | if (sfree >= levbytes) { /* new item fits into node S[h] without any shifting */ | |
1350 | if (!h) | |
1351 | tb->s0num = vn->vn_nr_item; | |
1352 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1353 | return NO_BALANCING_NEEDED; | |
1354 | } | |
1355 | ||
1356 | { | |
1357 | int lpar, rpar, nset, lset, rset, lrset; | |
0222e657 | 1358 | /* |
bd4c625c LT |
1359 | * regular overflowing of the node |
1360 | */ | |
1361 | ||
0222e657 | 1362 | /* get_num_ver works in 2 modes (FLOW & NO_FLOW) |
bd4c625c | 1363 | lpar, rpar - number of items we can shift to left/right neighbor (including splitting item) |
0222e657 | 1364 | nset, lset, rset, lrset - shows, whether flowing items give better packing |
bd4c625c | 1365 | */ |
1da177e4 | 1366 | #define FLOW 1 |
bd4c625c | 1367 | #define NO_FLOW 0 /* do not any splitting */ |
1da177e4 | 1368 | |
bd4c625c | 1369 | /* we choose one the following */ |
1da177e4 LT |
1370 | #define NOTHING_SHIFT_NO_FLOW 0 |
1371 | #define NOTHING_SHIFT_FLOW 5 | |
1372 | #define LEFT_SHIFT_NO_FLOW 10 | |
1373 | #define LEFT_SHIFT_FLOW 15 | |
1374 | #define RIGHT_SHIFT_NO_FLOW 20 | |
1375 | #define RIGHT_SHIFT_FLOW 25 | |
1376 | #define LR_SHIFT_NO_FLOW 30 | |
1377 | #define LR_SHIFT_FLOW 35 | |
1378 | ||
bd4c625c LT |
1379 | lpar = tb->lnum[h]; |
1380 | rpar = tb->rnum[h]; | |
1381 | ||
1382 | /* calculate number of blocks S[h] must be split into when | |
1383 | nothing is shifted to the neighbors, | |
1384 | as well as number of items in each part of the split node (s012 numbers), | |
1385 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any */ | |
1386 | nset = NOTHING_SHIFT_NO_FLOW; | |
1387 | nver = get_num_ver(vn->vn_mode, tb, h, | |
1388 | 0, -1, h ? vn->vn_nr_item : 0, -1, | |
1389 | snum012, NO_FLOW); | |
1390 | ||
1391 | if (!h) { | |
1392 | int nver1; | |
1393 | ||
1394 | /* note, that in this case we try to bottle between S[0] and S1 (S1 - the first new node) */ | |
1395 | nver1 = get_num_ver(vn->vn_mode, tb, h, | |
1396 | 0, -1, 0, -1, | |
1397 | snum012 + NOTHING_SHIFT_FLOW, FLOW); | |
1398 | if (nver > nver1) | |
1399 | nset = NOTHING_SHIFT_FLOW, nver = nver1; | |
1400 | } | |
1da177e4 | 1401 | |
bd4c625c LT |
1402 | /* calculate number of blocks S[h] must be split into when |
1403 | l_shift_num first items and l_shift_bytes of the right most | |
1404 | liquid item to be shifted are shifted to the left neighbor, | |
1405 | as well as number of items in each part of the splitted node (s012 numbers), | |
1406 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any | |
1407 | */ | |
1408 | lset = LEFT_SHIFT_NO_FLOW; | |
1409 | lnver = get_num_ver(vn->vn_mode, tb, h, | |
1410 | lpar - ((h || tb->lbytes == -1) ? 0 : 1), | |
1411 | -1, h ? vn->vn_nr_item : 0, -1, | |
1412 | snum012 + LEFT_SHIFT_NO_FLOW, NO_FLOW); | |
1413 | if (!h) { | |
1414 | int lnver1; | |
1415 | ||
1416 | lnver1 = get_num_ver(vn->vn_mode, tb, h, | |
1417 | lpar - | |
1418 | ((tb->lbytes != -1) ? 1 : 0), | |
1419 | tb->lbytes, 0, -1, | |
1420 | snum012 + LEFT_SHIFT_FLOW, FLOW); | |
1421 | if (lnver > lnver1) | |
1422 | lset = LEFT_SHIFT_FLOW, lnver = lnver1; | |
1423 | } | |
1da177e4 | 1424 | |
bd4c625c LT |
1425 | /* calculate number of blocks S[h] must be split into when |
1426 | r_shift_num first items and r_shift_bytes of the left most | |
1427 | liquid item to be shifted are shifted to the right neighbor, | |
1428 | as well as number of items in each part of the splitted node (s012 numbers), | |
1429 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any | |
1430 | */ | |
1431 | rset = RIGHT_SHIFT_NO_FLOW; | |
1432 | rnver = get_num_ver(vn->vn_mode, tb, h, | |
1433 | 0, -1, | |
1434 | h ? (vn->vn_nr_item - rpar) : (rpar - | |
1435 | ((tb-> | |
1436 | rbytes != | |
1437 | -1) ? 1 : | |
1438 | 0)), -1, | |
1439 | snum012 + RIGHT_SHIFT_NO_FLOW, NO_FLOW); | |
1440 | if (!h) { | |
1441 | int rnver1; | |
1442 | ||
1443 | rnver1 = get_num_ver(vn->vn_mode, tb, h, | |
1444 | 0, -1, | |
1445 | (rpar - | |
1446 | ((tb->rbytes != -1) ? 1 : 0)), | |
1447 | tb->rbytes, | |
1448 | snum012 + RIGHT_SHIFT_FLOW, FLOW); | |
1449 | ||
1450 | if (rnver > rnver1) | |
1451 | rset = RIGHT_SHIFT_FLOW, rnver = rnver1; | |
1452 | } | |
1da177e4 | 1453 | |
bd4c625c LT |
1454 | /* calculate number of blocks S[h] must be split into when |
1455 | items are shifted in both directions, | |
1456 | as well as number of items in each part of the splitted node (s012 numbers), | |
1457 | and number of bytes (s1bytes) of the shared drop which flow to S1 if any | |
1458 | */ | |
1459 | lrset = LR_SHIFT_NO_FLOW; | |
1460 | lrnver = get_num_ver(vn->vn_mode, tb, h, | |
1461 | lpar - ((h || tb->lbytes == -1) ? 0 : 1), | |
1462 | -1, | |
1463 | h ? (vn->vn_nr_item - rpar) : (rpar - | |
1464 | ((tb-> | |
1465 | rbytes != | |
1466 | -1) ? 1 : | |
1467 | 0)), -1, | |
1468 | snum012 + LR_SHIFT_NO_FLOW, NO_FLOW); | |
1469 | if (!h) { | |
1470 | int lrnver1; | |
1471 | ||
1472 | lrnver1 = get_num_ver(vn->vn_mode, tb, h, | |
1473 | lpar - | |
1474 | ((tb->lbytes != -1) ? 1 : 0), | |
1475 | tb->lbytes, | |
1476 | (rpar - | |
1477 | ((tb->rbytes != -1) ? 1 : 0)), | |
1478 | tb->rbytes, | |
1479 | snum012 + LR_SHIFT_FLOW, FLOW); | |
1480 | if (lrnver > lrnver1) | |
1481 | lrset = LR_SHIFT_FLOW, lrnver = lrnver1; | |
1482 | } | |
1da177e4 | 1483 | |
bd4c625c LT |
1484 | /* Our general shifting strategy is: |
1485 | 1) to minimized number of new nodes; | |
1486 | 2) to minimized number of neighbors involved in shifting; | |
1487 | 3) to minimized number of disk reads; */ | |
1488 | ||
1489 | /* we can win TWO or ONE nodes by shifting in both directions */ | |
1490 | if (lrnver < lnver && lrnver < rnver) { | |
1491 | RFALSE(h && | |
1492 | (tb->lnum[h] != 1 || | |
1493 | tb->rnum[h] != 1 || | |
1494 | lrnver != 1 || rnver != 2 || lnver != 2 | |
1495 | || h != 1), "vs-8230: bad h"); | |
1496 | if (lrset == LR_SHIFT_FLOW) | |
1497 | set_parameters(tb, h, tb->lnum[h], tb->rnum[h], | |
1498 | lrnver, snum012 + lrset, | |
1499 | tb->lbytes, tb->rbytes); | |
1500 | else | |
1501 | set_parameters(tb, h, | |
1502 | tb->lnum[h] - | |
1503 | ((tb->lbytes == -1) ? 0 : 1), | |
1504 | tb->rnum[h] - | |
1505 | ((tb->rbytes == -1) ? 0 : 1), | |
1506 | lrnver, snum012 + lrset, -1, -1); | |
1507 | ||
1508 | return CARRY_ON; | |
1509 | } | |
1da177e4 | 1510 | |
bd4c625c LT |
1511 | /* if shifting doesn't lead to better packing then don't shift */ |
1512 | if (nver == lrnver) { | |
1513 | set_parameters(tb, h, 0, 0, nver, snum012 + nset, -1, | |
1514 | -1); | |
1515 | return CARRY_ON; | |
1516 | } | |
1da177e4 | 1517 | |
bd4c625c LT |
1518 | /* now we know that for better packing shifting in only one |
1519 | direction either to the left or to the right is required */ | |
1da177e4 | 1520 | |
bd4c625c LT |
1521 | /* if shifting to the left is better than shifting to the right */ |
1522 | if (lnver < rnver) { | |
1523 | SET_PAR_SHIFT_LEFT; | |
1524 | return CARRY_ON; | |
1525 | } | |
1da177e4 | 1526 | |
bd4c625c LT |
1527 | /* if shifting to the right is better than shifting to the left */ |
1528 | if (lnver > rnver) { | |
1529 | SET_PAR_SHIFT_RIGHT; | |
1530 | return CARRY_ON; | |
1531 | } | |
1da177e4 | 1532 | |
bd4c625c LT |
1533 | /* now shifting in either direction gives the same number |
1534 | of nodes and we can make use of the cached neighbors */ | |
1535 | if (is_left_neighbor_in_cache(tb, h)) { | |
1536 | SET_PAR_SHIFT_LEFT; | |
1537 | return CARRY_ON; | |
1538 | } | |
1da177e4 | 1539 | |
bd4c625c LT |
1540 | /* shift to the right independently on whether the right neighbor in cache or not */ |
1541 | SET_PAR_SHIFT_RIGHT; | |
1542 | return CARRY_ON; | |
1da177e4 | 1543 | } |
1da177e4 LT |
1544 | } |
1545 | ||
1da177e4 LT |
1546 | /* Check whether current node S[h] is balanced when Decreasing its size by |
1547 | * Deleting or Cutting for INTERNAL node of S+tree. | |
1548 | * Calculate parameters for balancing for current level h. | |
1549 | * Parameters: | |
1550 | * tb tree_balance structure; | |
1551 | * h current level of the node; | |
1552 | * inum item number in S[h]; | |
1553 | * mode i - insert, p - paste; | |
0222e657 | 1554 | * Returns: 1 - schedule occurred; |
1da177e4 LT |
1555 | * 0 - balancing for higher levels needed; |
1556 | * -1 - no balancing for higher levels needed; | |
1557 | * -2 - no disk space. | |
1558 | * | |
1559 | * Note: Items of internal nodes have fixed size, so the balance condition for | |
1560 | * the internal part of S+tree is as for the B-trees. | |
1561 | */ | |
bd4c625c | 1562 | static int dc_check_balance_internal(struct tree_balance *tb, int h) |
1da177e4 | 1563 | { |
bd4c625c | 1564 | struct virtual_node *vn = tb->tb_vn; |
1da177e4 | 1565 | |
bd4c625c LT |
1566 | /* Sh is the node whose balance is currently being checked, |
1567 | and Fh is its father. */ | |
1568 | struct buffer_head *Sh, *Fh; | |
ee93961b | 1569 | int maxsize, ret; |
bd4c625c | 1570 | int lfree, rfree /* free space in L and R */ ; |
1da177e4 | 1571 | |
bd4c625c LT |
1572 | Sh = PATH_H_PBUFFER(tb->tb_path, h); |
1573 | Fh = PATH_H_PPARENT(tb->tb_path, h); | |
1da177e4 | 1574 | |
bd4c625c | 1575 | maxsize = MAX_CHILD_SIZE(Sh); |
1da177e4 LT |
1576 | |
1577 | /* using tb->insert_size[h], which is negative in this case, create_virtual_node calculates: */ | |
1578 | /* new_nr_item = number of items node would have if operation is */ | |
1579 | /* performed without balancing (new_nr_item); */ | |
bd4c625c | 1580 | create_virtual_node(tb, h); |
1da177e4 | 1581 | |
bd4c625c LT |
1582 | if (!Fh) { /* S[h] is the root. */ |
1583 | if (vn->vn_nr_item > 0) { | |
1584 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1585 | return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ | |
1586 | } | |
1587 | /* new_nr_item == 0. | |
1588 | * Current root will be deleted resulting in | |
1589 | * decrementing the tree height. */ | |
1590 | set_parameters(tb, h, 0, 0, 0, NULL, -1, -1); | |
1591 | return CARRY_ON; | |
1592 | } | |
1593 | ||
ee93961b JM |
1594 | if ((ret = get_parents(tb, h)) != CARRY_ON) |
1595 | return ret; | |
bd4c625c LT |
1596 | |
1597 | /* get free space of neighbors */ | |
1598 | rfree = get_rfree(tb, h); | |
1599 | lfree = get_lfree(tb, h); | |
1600 | ||
1601 | /* determine maximal number of items we can fit into neighbors */ | |
1602 | check_left(tb, h, lfree); | |
1603 | check_right(tb, h, rfree); | |
1604 | ||
1605 | if (vn->vn_nr_item >= MIN_NR_KEY(Sh)) { /* Balance condition for the internal node is valid. | |
1606 | * In this case we balance only if it leads to better packing. */ | |
1607 | if (vn->vn_nr_item == MIN_NR_KEY(Sh)) { /* Here we join S[h] with one of its neighbors, | |
1608 | * which is impossible with greater values of new_nr_item. */ | |
1609 | if (tb->lnum[h] >= vn->vn_nr_item + 1) { | |
1610 | /* All contents of S[h] can be moved to L[h]. */ | |
1611 | int n; | |
1612 | int order_L; | |
1613 | ||
1614 | order_L = | |
1615 | ((n = | |
1616 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1617 | h)) == | |
1618 | 0) ? B_NR_ITEMS(tb->FL[h]) : n - 1; | |
1619 | n = dc_size(B_N_CHILD(tb->FL[h], order_L)) / | |
1620 | (DC_SIZE + KEY_SIZE); | |
1621 | set_parameters(tb, h, -n - 1, 0, 0, NULL, -1, | |
1622 | -1); | |
1623 | return CARRY_ON; | |
1624 | } | |
1625 | ||
1626 | if (tb->rnum[h] >= vn->vn_nr_item + 1) { | |
1627 | /* All contents of S[h] can be moved to R[h]. */ | |
1628 | int n; | |
1629 | int order_R; | |
1630 | ||
1631 | order_R = | |
1632 | ((n = | |
1633 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1634 | h)) == | |
1635 | B_NR_ITEMS(Fh)) ? 0 : n + 1; | |
1636 | n = dc_size(B_N_CHILD(tb->FR[h], order_R)) / | |
1637 | (DC_SIZE + KEY_SIZE); | |
1638 | set_parameters(tb, h, 0, -n - 1, 0, NULL, -1, | |
1639 | -1); | |
1640 | return CARRY_ON; | |
1641 | } | |
1642 | } | |
1643 | ||
1644 | if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) { | |
1645 | /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */ | |
1646 | int to_r; | |
1647 | ||
1648 | to_r = | |
1649 | ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - | |
1650 | tb->rnum[h] + vn->vn_nr_item + 1) / 2 - | |
1651 | (MAX_NR_KEY(Sh) + 1 - tb->rnum[h]); | |
1652 | set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, | |
1653 | 0, NULL, -1, -1); | |
1654 | return CARRY_ON; | |
1655 | } | |
1656 | ||
1657 | /* Balancing does not lead to better packing. */ | |
1658 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1659 | return NO_BALANCING_NEEDED; | |
1da177e4 | 1660 | } |
bd4c625c LT |
1661 | |
1662 | /* Current node contain insufficient number of items. Balancing is required. */ | |
1663 | /* Check whether we can merge S[h] with left neighbor. */ | |
1664 | if (tb->lnum[h] >= vn->vn_nr_item + 1) | |
1665 | if (is_left_neighbor_in_cache(tb, h) | |
1666 | || tb->rnum[h] < vn->vn_nr_item + 1 || !tb->FR[h]) { | |
1667 | int n; | |
1668 | int order_L; | |
1669 | ||
1670 | order_L = | |
1671 | ((n = | |
1672 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1673 | h)) == | |
1674 | 0) ? B_NR_ITEMS(tb->FL[h]) : n - 1; | |
1675 | n = dc_size(B_N_CHILD(tb->FL[h], order_L)) / (DC_SIZE + | |
1676 | KEY_SIZE); | |
1677 | set_parameters(tb, h, -n - 1, 0, 0, NULL, -1, -1); | |
1678 | return CARRY_ON; | |
1679 | } | |
1680 | ||
1681 | /* Check whether we can merge S[h] with right neighbor. */ | |
1682 | if (tb->rnum[h] >= vn->vn_nr_item + 1) { | |
1683 | int n; | |
1684 | int order_R; | |
1685 | ||
1686 | order_R = | |
1687 | ((n = | |
1688 | PATH_H_B_ITEM_ORDER(tb->tb_path, | |
1689 | h)) == B_NR_ITEMS(Fh)) ? 0 : (n + 1); | |
1690 | n = dc_size(B_N_CHILD(tb->FR[h], order_R)) / (DC_SIZE + | |
1691 | KEY_SIZE); | |
1692 | set_parameters(tb, h, 0, -n - 1, 0, NULL, -1, -1); | |
1693 | return CARRY_ON; | |
1da177e4 LT |
1694 | } |
1695 | ||
bd4c625c LT |
1696 | /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */ |
1697 | if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) { | |
1698 | int to_r; | |
1699 | ||
1700 | to_r = | |
1701 | ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] + | |
1702 | vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - | |
1703 | tb->rnum[h]); | |
1704 | set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL, | |
1705 | -1, -1); | |
1706 | return CARRY_ON; | |
1707 | } | |
1da177e4 | 1708 | |
bd4c625c LT |
1709 | /* For internal nodes try to borrow item from a neighbor */ |
1710 | RFALSE(!tb->FL[h] && !tb->FR[h], "vs-8235: trying to borrow for root"); | |
1711 | ||
1712 | /* Borrow one or two items from caching neighbor */ | |
1713 | if (is_left_neighbor_in_cache(tb, h) || !tb->FR[h]) { | |
1714 | int from_l; | |
1715 | ||
1716 | from_l = | |
1717 | (MAX_NR_KEY(Sh) + 1 - tb->lnum[h] + vn->vn_nr_item + | |
1718 | 1) / 2 - (vn->vn_nr_item + 1); | |
1719 | set_parameters(tb, h, -from_l, 0, 1, NULL, -1, -1); | |
1720 | return CARRY_ON; | |
1da177e4 LT |
1721 | } |
1722 | ||
bd4c625c LT |
1723 | set_parameters(tb, h, 0, |
1724 | -((MAX_NR_KEY(Sh) + 1 - tb->rnum[h] + vn->vn_nr_item + | |
1725 | 1) / 2 - (vn->vn_nr_item + 1)), 1, NULL, -1, -1); | |
1da177e4 | 1726 | return CARRY_ON; |
1da177e4 LT |
1727 | } |
1728 | ||
1da177e4 LT |
1729 | /* Check whether current node S[h] is balanced when Decreasing its size by |
1730 | * Deleting or Truncating for LEAF node of S+tree. | |
1731 | * Calculate parameters for balancing for current level h. | |
1732 | * Parameters: | |
1733 | * tb tree_balance structure; | |
1734 | * h current level of the node; | |
1735 | * inum item number in S[h]; | |
1736 | * mode i - insert, p - paste; | |
0222e657 | 1737 | * Returns: 1 - schedule occurred; |
1da177e4 LT |
1738 | * 0 - balancing for higher levels needed; |
1739 | * -1 - no balancing for higher levels needed; | |
1740 | * -2 - no disk space. | |
1741 | */ | |
bd4c625c | 1742 | static int dc_check_balance_leaf(struct tree_balance *tb, int h) |
1da177e4 | 1743 | { |
bd4c625c LT |
1744 | struct virtual_node *vn = tb->tb_vn; |
1745 | ||
1746 | /* Number of bytes that must be deleted from | |
1747 | (value is negative if bytes are deleted) buffer which | |
1748 | contains node being balanced. The mnemonic is that the | |
1749 | attempted change in node space used level is levbytes bytes. */ | |
1750 | int levbytes; | |
1751 | /* the maximal item size */ | |
ee93961b | 1752 | int maxsize, ret; |
bd4c625c LT |
1753 | /* S0 is the node whose balance is currently being checked, |
1754 | and F0 is its father. */ | |
1755 | struct buffer_head *S0, *F0; | |
1756 | int lfree, rfree /* free space in L and R */ ; | |
1757 | ||
1758 | S0 = PATH_H_PBUFFER(tb->tb_path, 0); | |
1759 | F0 = PATH_H_PPARENT(tb->tb_path, 0); | |
1da177e4 | 1760 | |
bd4c625c | 1761 | levbytes = tb->insert_size[h]; |
1da177e4 | 1762 | |
bd4c625c LT |
1763 | maxsize = MAX_CHILD_SIZE(S0); /* maximal possible size of an item */ |
1764 | ||
1765 | if (!F0) { /* S[0] is the root now. */ | |
1766 | ||
1767 | RFALSE(-levbytes >= maxsize - B_FREE_SPACE(S0), | |
1768 | "vs-8240: attempt to create empty buffer tree"); | |
1769 | ||
1770 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1771 | return NO_BALANCING_NEEDED; | |
1772 | } | |
1773 | ||
ee93961b JM |
1774 | if ((ret = get_parents(tb, h)) != CARRY_ON) |
1775 | return ret; | |
bd4c625c LT |
1776 | |
1777 | /* get free space of neighbors */ | |
1778 | rfree = get_rfree(tb, h); | |
1779 | lfree = get_lfree(tb, h); | |
1780 | ||
1781 | create_virtual_node(tb, h); | |
1782 | ||
1783 | /* if 3 leaves can be merge to one, set parameters and return */ | |
1784 | if (are_leaves_removable(tb, lfree, rfree)) | |
1785 | return CARRY_ON; | |
1786 | ||
1787 | /* determine maximal number of items we can shift to the left/right neighbor | |
1788 | and the maximal number of bytes that can flow to the left/right neighbor | |
1789 | from the left/right most liquid item that cannot be shifted from S[0] entirely | |
1790 | */ | |
1791 | check_left(tb, h, lfree); | |
1792 | check_right(tb, h, rfree); | |
1793 | ||
1794 | /* check whether we can merge S with left neighbor. */ | |
1795 | if (tb->lnum[0] >= vn->vn_nr_item && tb->lbytes == -1) | |
1796 | 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 */ | |
1797 | !tb->FR[h]) { | |
1798 | ||
1799 | RFALSE(!tb->FL[h], | |
1800 | "vs-8245: dc_check_balance_leaf: FL[h] must exist"); | |
1801 | ||
1802 | /* set parameter to merge S[0] with its left neighbor */ | |
1803 | set_parameters(tb, h, -1, 0, 0, NULL, -1, -1); | |
1804 | return CARRY_ON; | |
1805 | } | |
1806 | ||
1807 | /* check whether we can merge S[0] with right neighbor. */ | |
1808 | if (tb->rnum[0] >= vn->vn_nr_item && tb->rbytes == -1) { | |
1809 | set_parameters(tb, h, 0, -1, 0, NULL, -1, -1); | |
1810 | return CARRY_ON; | |
1811 | } | |
1812 | ||
1813 | /* All contents of S[0] can be moved to the neighbors (L[0] & R[0]). Set parameters and return */ | |
1814 | if (is_leaf_removable(tb)) | |
1815 | return CARRY_ON; | |
1816 | ||
1817 | /* Balancing is not required. */ | |
1818 | tb->s0num = vn->vn_nr_item; | |
1819 | set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); | |
1820 | return NO_BALANCING_NEEDED; | |
1821 | } | |
1da177e4 LT |
1822 | |
1823 | /* Check whether current node S[h] is balanced when Decreasing its size by | |
1824 | * Deleting or Cutting. | |
1825 | * Calculate parameters for balancing for current level h. | |
1826 | * Parameters: | |
1827 | * tb tree_balance structure; | |
1828 | * h current level of the node; | |
1829 | * inum item number in S[h]; | |
1830 | * mode d - delete, c - cut. | |
0222e657 | 1831 | * Returns: 1 - schedule occurred; |
1da177e4 LT |
1832 | * 0 - balancing for higher levels needed; |
1833 | * -1 - no balancing for higher levels needed; | |
1834 | * -2 - no disk space. | |
1835 | */ | |
bd4c625c | 1836 | static int dc_check_balance(struct tree_balance *tb, int h) |
1da177e4 | 1837 | { |
bd4c625c LT |
1838 | RFALSE(!(PATH_H_PBUFFER(tb->tb_path, h)), |
1839 | "vs-8250: S is not initialized"); | |
1da177e4 | 1840 | |
bd4c625c LT |
1841 | if (h) |
1842 | return dc_check_balance_internal(tb, h); | |
1843 | else | |
1844 | return dc_check_balance_leaf(tb, h); | |
1da177e4 LT |
1845 | } |
1846 | ||
1da177e4 LT |
1847 | /* Check whether current node S[h] is balanced. |
1848 | * Calculate parameters for balancing for current level h. | |
1849 | * Parameters: | |
1850 | * | |
1851 | * tb tree_balance structure: | |
1852 | * | |
1853 | * tb is a large structure that must be read about in the header file | |
1854 | * at the same time as this procedure if the reader is to successfully | |
1855 | * understand this procedure | |
1856 | * | |
1857 | * h current level of the node; | |
1858 | * inum item number in S[h]; | |
1859 | * mode i - insert, p - paste, d - delete, c - cut. | |
0222e657 | 1860 | * Returns: 1 - schedule occurred; |
1da177e4 LT |
1861 | * 0 - balancing for higher levels needed; |
1862 | * -1 - no balancing for higher levels needed; | |
1863 | * -2 - no disk space. | |
1864 | */ | |
bd4c625c LT |
1865 | static int check_balance(int mode, |
1866 | struct tree_balance *tb, | |
1867 | int h, | |
1868 | int inum, | |
1869 | int pos_in_item, | |
1870 | struct item_head *ins_ih, const void *data) | |
1da177e4 | 1871 | { |
bd4c625c | 1872 | struct virtual_node *vn; |
1da177e4 | 1873 | |
bd4c625c LT |
1874 | vn = tb->tb_vn = (struct virtual_node *)(tb->vn_buf); |
1875 | vn->vn_free_ptr = (char *)(tb->tb_vn + 1); | |
1876 | vn->vn_mode = mode; | |
1877 | vn->vn_affected_item_num = inum; | |
1878 | vn->vn_pos_in_item = pos_in_item; | |
1879 | vn->vn_ins_ih = ins_ih; | |
1880 | vn->vn_data = data; | |
1da177e4 | 1881 | |
bd4c625c LT |
1882 | RFALSE(mode == M_INSERT && !vn->vn_ins_ih, |
1883 | "vs-8255: ins_ih can not be 0 in insert mode"); | |
1da177e4 | 1884 | |
bd4c625c LT |
1885 | if (tb->insert_size[h] > 0) |
1886 | /* Calculate balance parameters when size of node is increasing. */ | |
1887 | return ip_check_balance(tb, h); | |
1da177e4 | 1888 | |
bd4c625c LT |
1889 | /* Calculate balance parameters when size of node is decreasing. */ |
1890 | return dc_check_balance(tb, h); | |
1da177e4 LT |
1891 | } |
1892 | ||
bd4c625c | 1893 | /* Check whether parent at the path is the really parent of the current node.*/ |
ee93961b | 1894 | static int get_direct_parent(struct tree_balance *tb, int h) |
bd4c625c | 1895 | { |
ad31a4fc | 1896 | struct buffer_head *bh; |
d68caa95 | 1897 | struct treepath *path = tb->tb_path; |
ee93961b JM |
1898 | int position, |
1899 | path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h); | |
bd4c625c LT |
1900 | |
1901 | /* We are in the root or in the new root. */ | |
ee93961b | 1902 | if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) { |
bd4c625c | 1903 | |
ee93961b | 1904 | RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET - 1, |
bd4c625c LT |
1905 | "PAP-8260: invalid offset in the path"); |
1906 | ||
d68caa95 | 1907 | if (PATH_OFFSET_PBUFFER(path, FIRST_PATH_ELEMENT_OFFSET)-> |
a063ae17 | 1908 | b_blocknr == SB_ROOT_BLOCK(tb->tb_sb)) { |
bd4c625c | 1909 | /* Root is not changed. */ |
ee93961b JM |
1910 | PATH_OFFSET_PBUFFER(path, path_offset - 1) = NULL; |
1911 | PATH_OFFSET_POSITION(path, path_offset - 1) = 0; | |
bd4c625c LT |
1912 | return CARRY_ON; |
1913 | } | |
1914 | return REPEAT_SEARCH; /* Root is changed and we must recalculate the path. */ | |
1915 | } | |
1916 | ||
1917 | if (!B_IS_IN_TREE | |
ee93961b | 1918 | (bh = PATH_OFFSET_PBUFFER(path, path_offset - 1))) |
bd4c625c | 1919 | return REPEAT_SEARCH; /* Parent in the path is not in the tree. */ |
1da177e4 | 1920 | |
ee93961b | 1921 | if ((position = |
d68caa95 | 1922 | PATH_OFFSET_POSITION(path, |
ee93961b | 1923 | path_offset - 1)) > B_NR_ITEMS(bh)) |
bd4c625c | 1924 | return REPEAT_SEARCH; |
1da177e4 | 1925 | |
ee93961b JM |
1926 | if (B_N_CHILD_NUM(bh, position) != |
1927 | PATH_OFFSET_PBUFFER(path, path_offset)->b_blocknr) | |
bd4c625c LT |
1928 | /* Parent in the path is not parent of the current node in the tree. */ |
1929 | return REPEAT_SEARCH; | |
1930 | ||
ad31a4fc | 1931 | if (buffer_locked(bh)) { |
278f6679 | 1932 | int depth = reiserfs_write_unlock_nested(tb->tb_sb); |
ad31a4fc | 1933 | __wait_on_buffer(bh); |
278f6679 | 1934 | reiserfs_write_lock_nested(tb->tb_sb, depth); |
a063ae17 | 1935 | if (FILESYSTEM_CHANGED_TB(tb)) |
bd4c625c | 1936 | return REPEAT_SEARCH; |
1da177e4 | 1937 | } |
1da177e4 | 1938 | |
bd4c625c LT |
1939 | return CARRY_ON; /* Parent in the path is unlocked and really parent of the current node. */ |
1940 | } | |
1da177e4 | 1941 | |
ee93961b JM |
1942 | /* Using lnum[h] and rnum[h] we should determine what neighbors |
1943 | * of S[h] we | |
1944 | * need in order to balance S[h], and get them if necessary. | |
1da177e4 LT |
1945 | * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; |
1946 | * CARRY_ON - schedule didn't occur while the function worked; | |
1947 | */ | |
ee93961b | 1948 | static int get_neighbors(struct tree_balance *tb, int h) |
bd4c625c | 1949 | { |
ee93961b JM |
1950 | int child_position, |
1951 | path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h + 1); | |
1952 | unsigned long son_number; | |
a063ae17 | 1953 | struct super_block *sb = tb->tb_sb; |
ad31a4fc | 1954 | struct buffer_head *bh; |
278f6679 | 1955 | int depth; |
bd4c625c | 1956 | |
ee93961b | 1957 | PROC_INFO_INC(sb, get_neighbors[h]); |
bd4c625c | 1958 | |
ee93961b JM |
1959 | if (tb->lnum[h]) { |
1960 | /* We need left neighbor to balance S[h]. */ | |
1961 | PROC_INFO_INC(sb, need_l_neighbor[h]); | |
1962 | bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset); | |
bd4c625c | 1963 | |
ee93961b JM |
1964 | RFALSE(bh == tb->FL[h] && |
1965 | !PATH_OFFSET_POSITION(tb->tb_path, path_offset), | |
bd4c625c LT |
1966 | "PAP-8270: invalid position in the parent"); |
1967 | ||
ee93961b | 1968 | child_position = |
ad31a4fc | 1969 | (bh == |
ee93961b JM |
1970 | tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb-> |
1971 | FL[h]); | |
1972 | son_number = B_N_CHILD_NUM(tb->FL[h], child_position); | |
278f6679 | 1973 | depth = reiserfs_write_unlock_nested(tb->tb_sb); |
ee93961b | 1974 | bh = sb_bread(sb, son_number); |
278f6679 | 1975 | reiserfs_write_lock_nested(tb->tb_sb, depth); |
ad31a4fc | 1976 | if (!bh) |
bd4c625c | 1977 | return IO_ERROR; |
a063ae17 | 1978 | if (FILESYSTEM_CHANGED_TB(tb)) { |
ad31a4fc | 1979 | brelse(bh); |
ee93961b | 1980 | PROC_INFO_INC(sb, get_neighbors_restart[h]); |
bd4c625c LT |
1981 | return REPEAT_SEARCH; |
1982 | } | |
1983 | ||
ee93961b JM |
1984 | RFALSE(!B_IS_IN_TREE(tb->FL[h]) || |
1985 | child_position > B_NR_ITEMS(tb->FL[h]) || | |
1986 | B_N_CHILD_NUM(tb->FL[h], child_position) != | |
ad31a4fc JM |
1987 | bh->b_blocknr, "PAP-8275: invalid parent"); |
1988 | RFALSE(!B_IS_IN_TREE(bh), "PAP-8280: invalid child"); | |
ee93961b | 1989 | RFALSE(!h && |
ad31a4fc JM |
1990 | B_FREE_SPACE(bh) != |
1991 | MAX_CHILD_SIZE(bh) - | |
ee93961b | 1992 | dc_size(B_N_CHILD(tb->FL[0], child_position)), |
bd4c625c LT |
1993 | "PAP-8290: invalid child size of left neighbor"); |
1994 | ||
ee93961b JM |
1995 | brelse(tb->L[h]); |
1996 | tb->L[h] = bh; | |
1da177e4 | 1997 | } |
bd4c625c | 1998 | |
ee93961b JM |
1999 | /* We need right neighbor to balance S[path_offset]. */ |
2000 | if (tb->rnum[h]) { /* We need right neighbor to balance S[path_offset]. */ | |
2001 | PROC_INFO_INC(sb, need_r_neighbor[h]); | |
2002 | bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset); | |
bd4c625c | 2003 | |
ee93961b | 2004 | RFALSE(bh == tb->FR[h] && |
a063ae17 | 2005 | PATH_OFFSET_POSITION(tb->tb_path, |
ee93961b | 2006 | path_offset) >= |
ad31a4fc | 2007 | B_NR_ITEMS(bh), |
bd4c625c LT |
2008 | "PAP-8295: invalid position in the parent"); |
2009 | ||
ee93961b JM |
2010 | child_position = |
2011 | (bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0; | |
2012 | son_number = B_N_CHILD_NUM(tb->FR[h], child_position); | |
278f6679 | 2013 | depth = reiserfs_write_unlock_nested(tb->tb_sb); |
ee93961b | 2014 | bh = sb_bread(sb, son_number); |
278f6679 | 2015 | reiserfs_write_lock_nested(tb->tb_sb, depth); |
ad31a4fc | 2016 | if (!bh) |
bd4c625c | 2017 | return IO_ERROR; |
a063ae17 | 2018 | if (FILESYSTEM_CHANGED_TB(tb)) { |
ad31a4fc | 2019 | brelse(bh); |
ee93961b | 2020 | PROC_INFO_INC(sb, get_neighbors_restart[h]); |
bd4c625c LT |
2021 | return REPEAT_SEARCH; |
2022 | } | |
ee93961b JM |
2023 | brelse(tb->R[h]); |
2024 | tb->R[h] = bh; | |
bd4c625c | 2025 | |
ee93961b | 2026 | RFALSE(!h |
ad31a4fc JM |
2027 | && B_FREE_SPACE(bh) != |
2028 | MAX_CHILD_SIZE(bh) - | |
ee93961b | 2029 | dc_size(B_N_CHILD(tb->FR[0], child_position)), |
bd4c625c | 2030 | "PAP-8300: invalid child size of right neighbor (%d != %d - %d)", |
ad31a4fc | 2031 | B_FREE_SPACE(bh), MAX_CHILD_SIZE(bh), |
ee93961b | 2032 | dc_size(B_N_CHILD(tb->FR[0], child_position))); |
bd4c625c | 2033 | |
1da177e4 | 2034 | } |
bd4c625c | 2035 | return CARRY_ON; |
1da177e4 LT |
2036 | } |
2037 | ||
bd4c625c | 2038 | static int get_virtual_node_size(struct super_block *sb, struct buffer_head *bh) |
1da177e4 | 2039 | { |
bd4c625c LT |
2040 | int max_num_of_items; |
2041 | int max_num_of_entries; | |
2042 | unsigned long blocksize = sb->s_blocksize; | |
1da177e4 LT |
2043 | |
2044 | #define MIN_NAME_LEN 1 | |
2045 | ||
bd4c625c LT |
2046 | max_num_of_items = (blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN); |
2047 | max_num_of_entries = (blocksize - BLKH_SIZE - IH_SIZE) / | |
2048 | (DEH_SIZE + MIN_NAME_LEN); | |
1da177e4 | 2049 | |
bd4c625c LT |
2050 | return sizeof(struct virtual_node) + |
2051 | max(max_num_of_items * sizeof(struct virtual_item), | |
2052 | sizeof(struct virtual_item) + sizeof(struct direntry_uarea) + | |
2053 | (max_num_of_entries - 1) * sizeof(__u16)); | |
1da177e4 LT |
2054 | } |
2055 | ||
1da177e4 LT |
2056 | /* maybe we should fail balancing we are going to perform when kmalloc |
2057 | fails several times. But now it will loop until kmalloc gets | |
2058 | required memory */ | |
bd4c625c | 2059 | static int get_mem_for_virtual_node(struct tree_balance *tb) |
1da177e4 | 2060 | { |
bd4c625c LT |
2061 | int check_fs = 0; |
2062 | int size; | |
2063 | char *buf; | |
2064 | ||
2065 | size = get_virtual_node_size(tb->tb_sb, PATH_PLAST_BUFFER(tb->tb_path)); | |
2066 | ||
2067 | if (size > tb->vn_buf_size) { | |
2068 | /* we have to allocate more memory for virtual node */ | |
2069 | if (tb->vn_buf) { | |
2070 | /* free memory allocated before */ | |
d739b42b | 2071 | kfree(tb->vn_buf); |
bd4c625c LT |
2072 | /* this is not needed if kfree is atomic */ |
2073 | check_fs = 1; | |
2074 | } | |
1da177e4 | 2075 | |
bd4c625c LT |
2076 | /* virtual node requires now more memory */ |
2077 | tb->vn_buf_size = size; | |
2078 | ||
2079 | /* get memory for virtual item */ | |
d739b42b | 2080 | buf = kmalloc(size, GFP_ATOMIC | __GFP_NOWARN); |
bd4c625c LT |
2081 | if (!buf) { |
2082 | /* getting memory with GFP_KERNEL priority may involve | |
2083 | balancing now (due to indirect_to_direct conversion on | |
2084 | dcache shrinking). So, release path and collected | |
2085 | resources here */ | |
2086 | free_buffers_in_tb(tb); | |
d739b42b | 2087 | buf = kmalloc(size, GFP_NOFS); |
bd4c625c | 2088 | if (!buf) { |
bd4c625c LT |
2089 | tb->vn_buf_size = 0; |
2090 | } | |
2091 | tb->vn_buf = buf; | |
2092 | schedule(); | |
2093 | return REPEAT_SEARCH; | |
2094 | } | |
1da177e4 | 2095 | |
bd4c625c LT |
2096 | tb->vn_buf = buf; |
2097 | } | |
1da177e4 | 2098 | |
bd4c625c LT |
2099 | if (check_fs && FILESYSTEM_CHANGED_TB(tb)) |
2100 | return REPEAT_SEARCH; | |
1da177e4 | 2101 | |
bd4c625c | 2102 | return CARRY_ON; |
1da177e4 LT |
2103 | } |
2104 | ||
1da177e4 | 2105 | #ifdef CONFIG_REISERFS_CHECK |
a9dd3643 | 2106 | static void tb_buffer_sanity_check(struct super_block *sb, |
ad31a4fc | 2107 | struct buffer_head *bh, |
bd4c625c | 2108 | const char *descr, int level) |
1da177e4 | 2109 | { |
ad31a4fc JM |
2110 | if (bh) { |
2111 | if (atomic_read(&(bh->b_count)) <= 0) | |
1da177e4 | 2112 | |
a9dd3643 | 2113 | reiserfs_panic(sb, "jmacd-1", "negative or zero " |
c3a9c210 | 2114 | "reference counter for buffer %s[%d] " |
ad31a4fc | 2115 | "(%b)", descr, level, bh); |
1da177e4 | 2116 | |
ad31a4fc | 2117 | if (!buffer_uptodate(bh)) |
a9dd3643 | 2118 | reiserfs_panic(sb, "jmacd-2", "buffer is not up " |
c3a9c210 | 2119 | "to date %s[%d] (%b)", |
ad31a4fc | 2120 | descr, level, bh); |
1da177e4 | 2121 | |
ad31a4fc | 2122 | if (!B_IS_IN_TREE(bh)) |
a9dd3643 | 2123 | reiserfs_panic(sb, "jmacd-3", "buffer is not " |
c3a9c210 | 2124 | "in tree %s[%d] (%b)", |
ad31a4fc | 2125 | descr, level, bh); |
1da177e4 | 2126 | |
ad31a4fc | 2127 | if (bh->b_bdev != sb->s_bdev) |
a9dd3643 | 2128 | reiserfs_panic(sb, "jmacd-4", "buffer has wrong " |
c3a9c210 | 2129 | "device %s[%d] (%b)", |
ad31a4fc | 2130 | descr, level, bh); |
1da177e4 | 2131 | |
ad31a4fc | 2132 | if (bh->b_size != sb->s_blocksize) |
a9dd3643 | 2133 | reiserfs_panic(sb, "jmacd-5", "buffer has wrong " |
c3a9c210 | 2134 | "blocksize %s[%d] (%b)", |
ad31a4fc | 2135 | descr, level, bh); |
1da177e4 | 2136 | |
ad31a4fc | 2137 | if (bh->b_blocknr > SB_BLOCK_COUNT(sb)) |
a9dd3643 | 2138 | reiserfs_panic(sb, "jmacd-6", "buffer block " |
c3a9c210 | 2139 | "number too high %s[%d] (%b)", |
ad31a4fc | 2140 | descr, level, bh); |
bd4c625c LT |
2141 | } |
2142 | } | |
2143 | #else | |
a9dd3643 | 2144 | static void tb_buffer_sanity_check(struct super_block *sb, |
ad31a4fc | 2145 | struct buffer_head *bh, |
bd4c625c LT |
2146 | const char *descr, int level) |
2147 | {; | |
2148 | } | |
2149 | #endif | |
1da177e4 | 2150 | |
bd4c625c LT |
2151 | static int clear_all_dirty_bits(struct super_block *s, struct buffer_head *bh) |
2152 | { | |
2153 | return reiserfs_prepare_for_journal(s, bh, 0); | |
2154 | } | |
1da177e4 | 2155 | |
a063ae17 | 2156 | static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) |
bd4c625c LT |
2157 | { |
2158 | struct buffer_head *locked; | |
2159 | #ifdef CONFIG_REISERFS_CHECK | |
2160 | int repeat_counter = 0; | |
2161 | #endif | |
2162 | int i; | |
1da177e4 | 2163 | |
bd4c625c | 2164 | do { |
1da177e4 | 2165 | |
bd4c625c LT |
2166 | locked = NULL; |
2167 | ||
a063ae17 | 2168 | for (i = tb->tb_path->path_length; |
bd4c625c | 2169 | !locked && i > ILLEGAL_PATH_ELEMENT_OFFSET; i--) { |
a063ae17 | 2170 | if (PATH_OFFSET_PBUFFER(tb->tb_path, i)) { |
bd4c625c LT |
2171 | /* if I understand correctly, we can only be sure the last buffer |
2172 | ** in the path is in the tree --clm | |
2173 | */ | |
2174 | #ifdef CONFIG_REISERFS_CHECK | |
a063ae17 JM |
2175 | if (PATH_PLAST_BUFFER(tb->tb_path) == |
2176 | PATH_OFFSET_PBUFFER(tb->tb_path, i)) | |
2177 | tb_buffer_sanity_check(tb->tb_sb, | |
bd4c625c | 2178 | PATH_OFFSET_PBUFFER |
a063ae17 | 2179 | (tb->tb_path, |
bd4c625c | 2180 | i), "S", |
a063ae17 | 2181 | tb->tb_path-> |
bd4c625c | 2182 | path_length - i); |
bd4c625c | 2183 | #endif |
a063ae17 | 2184 | if (!clear_all_dirty_bits(tb->tb_sb, |
bd4c625c | 2185 | PATH_OFFSET_PBUFFER |
a063ae17 | 2186 | (tb->tb_path, |
bd4c625c LT |
2187 | i))) { |
2188 | locked = | |
a063ae17 | 2189 | PATH_OFFSET_PBUFFER(tb->tb_path, |
bd4c625c LT |
2190 | i); |
2191 | } | |
2192 | } | |
1da177e4 LT |
2193 | } |
2194 | ||
a063ae17 | 2195 | for (i = 0; !locked && i < MAX_HEIGHT && tb->insert_size[i]; |
bd4c625c LT |
2196 | i++) { |
2197 | ||
a063ae17 | 2198 | if (tb->lnum[i]) { |
bd4c625c | 2199 | |
a063ae17 JM |
2200 | if (tb->L[i]) { |
2201 | tb_buffer_sanity_check(tb->tb_sb, | |
2202 | tb->L[i], | |
bd4c625c LT |
2203 | "L", i); |
2204 | if (!clear_all_dirty_bits | |
a063ae17 JM |
2205 | (tb->tb_sb, tb->L[i])) |
2206 | locked = tb->L[i]; | |
bd4c625c LT |
2207 | } |
2208 | ||
a063ae17 JM |
2209 | if (!locked && tb->FL[i]) { |
2210 | tb_buffer_sanity_check(tb->tb_sb, | |
2211 | tb->FL[i], | |
bd4c625c LT |
2212 | "FL", i); |
2213 | if (!clear_all_dirty_bits | |
a063ae17 JM |
2214 | (tb->tb_sb, tb->FL[i])) |
2215 | locked = tb->FL[i]; | |
bd4c625c LT |
2216 | } |
2217 | ||
a063ae17 JM |
2218 | if (!locked && tb->CFL[i]) { |
2219 | tb_buffer_sanity_check(tb->tb_sb, | |
2220 | tb->CFL[i], | |
bd4c625c LT |
2221 | "CFL", i); |
2222 | if (!clear_all_dirty_bits | |
a063ae17 JM |
2223 | (tb->tb_sb, tb->CFL[i])) |
2224 | locked = tb->CFL[i]; | |
bd4c625c LT |
2225 | } |
2226 | ||
2227 | } | |
2228 | ||
a063ae17 | 2229 | if (!locked && (tb->rnum[i])) { |
bd4c625c | 2230 | |
a063ae17 JM |
2231 | if (tb->R[i]) { |
2232 | tb_buffer_sanity_check(tb->tb_sb, | |
2233 | tb->R[i], | |
bd4c625c LT |
2234 | "R", i); |
2235 | if (!clear_all_dirty_bits | |
a063ae17 JM |
2236 | (tb->tb_sb, tb->R[i])) |
2237 | locked = tb->R[i]; | |
bd4c625c LT |
2238 | } |
2239 | ||
a063ae17 JM |
2240 | if (!locked && tb->FR[i]) { |
2241 | tb_buffer_sanity_check(tb->tb_sb, | |
2242 | tb->FR[i], | |
bd4c625c LT |
2243 | "FR", i); |
2244 | if (!clear_all_dirty_bits | |
a063ae17 JM |
2245 | (tb->tb_sb, tb->FR[i])) |
2246 | locked = tb->FR[i]; | |
bd4c625c LT |
2247 | } |
2248 | ||
a063ae17 JM |
2249 | if (!locked && tb->CFR[i]) { |
2250 | tb_buffer_sanity_check(tb->tb_sb, | |
2251 | tb->CFR[i], | |
bd4c625c LT |
2252 | "CFR", i); |
2253 | if (!clear_all_dirty_bits | |
a063ae17 JM |
2254 | (tb->tb_sb, tb->CFR[i])) |
2255 | locked = tb->CFR[i]; | |
bd4c625c LT |
2256 | } |
2257 | } | |
2258 | } | |
2259 | /* as far as I can tell, this is not required. The FEB list seems | |
2260 | ** to be full of newly allocated nodes, which will never be locked, | |
2261 | ** dirty, or anything else. | |
2262 | ** To be safe, I'm putting in the checks and waits in. For the moment, | |
2263 | ** they are needed to keep the code in journal.c from complaining | |
2264 | ** about the buffer. That code is inside CONFIG_REISERFS_CHECK as well. | |
2265 | ** --clm | |
2266 | */ | |
2267 | for (i = 0; !locked && i < MAX_FEB_SIZE; i++) { | |
a063ae17 | 2268 | if (tb->FEB[i]) { |
bd4c625c | 2269 | if (!clear_all_dirty_bits |
a063ae17 JM |
2270 | (tb->tb_sb, tb->FEB[i])) |
2271 | locked = tb->FEB[i]; | |
bd4c625c | 2272 | } |
1da177e4 | 2273 | } |
1da177e4 | 2274 | |
bd4c625c | 2275 | if (locked) { |
278f6679 | 2276 | int depth; |
1da177e4 | 2277 | #ifdef CONFIG_REISERFS_CHECK |
bd4c625c LT |
2278 | repeat_counter++; |
2279 | if ((repeat_counter % 10000) == 0) { | |
a063ae17 | 2280 | reiserfs_warning(tb->tb_sb, "reiserfs-8200", |
45b03d5e JM |
2281 | "too many iterations waiting " |
2282 | "for buffer to unlock " | |
bd4c625c LT |
2283 | "(%b)", locked); |
2284 | ||
2285 | /* Don't loop forever. Try to recover from possible error. */ | |
2286 | ||
a063ae17 | 2287 | return (FILESYSTEM_CHANGED_TB(tb)) ? |
bd4c625c LT |
2288 | REPEAT_SEARCH : CARRY_ON; |
2289 | } | |
1da177e4 | 2290 | #endif |
278f6679 | 2291 | depth = reiserfs_write_unlock_nested(tb->tb_sb); |
bd4c625c | 2292 | __wait_on_buffer(locked); |
278f6679 | 2293 | reiserfs_write_lock_nested(tb->tb_sb, depth); |
a063ae17 | 2294 | if (FILESYSTEM_CHANGED_TB(tb)) |
bd4c625c | 2295 | return REPEAT_SEARCH; |
bd4c625c | 2296 | } |
1da177e4 | 2297 | |
bd4c625c | 2298 | } while (locked); |
1da177e4 | 2299 | |
bd4c625c | 2300 | return CARRY_ON; |
1da177e4 LT |
2301 | } |
2302 | ||
1da177e4 LT |
2303 | /* Prepare for balancing, that is |
2304 | * get all necessary parents, and neighbors; | |
2305 | * analyze what and where should be moved; | |
2306 | * get sufficient number of new nodes; | |
2307 | * Balancing will start only after all resources will be collected at a time. | |
0222e657 | 2308 | * |
1da177e4 LT |
2309 | * When ported to SMP kernels, only at the last moment after all needed nodes |
2310 | * are collected in cache, will the resources be locked using the usual | |
2311 | * textbook ordered lock acquisition algorithms. Note that ensuring that | |
2312 | * this code neither write locks what it does not need to write lock nor locks out of order | |
2313 | * will be a pain in the butt that could have been avoided. Grumble grumble. -Hans | |
0222e657 | 2314 | * |
1da177e4 | 2315 | * fix is meant in the sense of render unchanging |
0222e657 | 2316 | * |
1da177e4 LT |
2317 | * Latency might be improved by first gathering a list of what buffers are needed |
2318 | * and then getting as many of them in parallel as possible? -Hans | |
2319 | * | |
2320 | * Parameters: | |
2321 | * op_mode i - insert, d - delete, c - cut (truncate), p - paste (append) | |
2322 | * tb tree_balance structure; | |
2323 | * inum item number in S[h]; | |
2324 | * pos_in_item - comment this if you can | |
a063ae17 JM |
2325 | * ins_ih item head of item being inserted |
2326 | * data inserted item or data to be pasted | |
1da177e4 LT |
2327 | * Returns: 1 - schedule occurred while the function worked; |
2328 | * 0 - schedule didn't occur while the function worked; | |
0222e657 | 2329 | * -1 - if no_disk_space |
1da177e4 LT |
2330 | */ |
2331 | ||
ee93961b | 2332 | int fix_nodes(int op_mode, struct tree_balance *tb, |
d68caa95 | 2333 | struct item_head *ins_ih, const void *data) |
bd4c625c | 2334 | { |
ee93961b JM |
2335 | int ret, h, item_num = PATH_LAST_POSITION(tb->tb_path); |
2336 | int pos_in_item; | |
1da177e4 | 2337 | |
bd4c625c LT |
2338 | /* we set wait_tb_buffers_run when we have to restore any dirty bits cleared |
2339 | ** during wait_tb_buffers_run | |
2340 | */ | |
2341 | int wait_tb_buffers_run = 0; | |
a063ae17 | 2342 | struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path); |
1da177e4 | 2343 | |
a063ae17 | 2344 | ++REISERFS_SB(tb->tb_sb)->s_fix_nodes; |
bd4c625c | 2345 | |
ee93961b | 2346 | pos_in_item = tb->tb_path->pos_in_item; |
bd4c625c | 2347 | |
a063ae17 | 2348 | tb->fs_gen = get_generation(tb->tb_sb); |
1da177e4 | 2349 | |
bd4c625c LT |
2350 | /* we prepare and log the super here so it will already be in the |
2351 | ** transaction when do_balance needs to change it. | |
2352 | ** This way do_balance won't have to schedule when trying to prepare | |
2353 | ** the super for logging | |
2354 | */ | |
a063ae17 JM |
2355 | reiserfs_prepare_for_journal(tb->tb_sb, |
2356 | SB_BUFFER_WITH_SB(tb->tb_sb), 1); | |
2357 | journal_mark_dirty(tb->transaction_handle, tb->tb_sb, | |
2358 | SB_BUFFER_WITH_SB(tb->tb_sb)); | |
2359 | if (FILESYSTEM_CHANGED_TB(tb)) | |
bd4c625c | 2360 | return REPEAT_SEARCH; |
1da177e4 | 2361 | |
bd4c625c | 2362 | /* if it possible in indirect_to_direct conversion */ |
a063ae17 | 2363 | if (buffer_locked(tbS0)) { |
278f6679 | 2364 | int depth = reiserfs_write_unlock_nested(tb->tb_sb); |
a063ae17 | 2365 | __wait_on_buffer(tbS0); |
278f6679 | 2366 | reiserfs_write_lock_nested(tb->tb_sb, depth); |
a063ae17 | 2367 | if (FILESYSTEM_CHANGED_TB(tb)) |
bd4c625c LT |
2368 | return REPEAT_SEARCH; |
2369 | } | |
2370 | #ifdef CONFIG_REISERFS_CHECK | |
08f14fc8 | 2371 | if (REISERFS_SB(tb->tb_sb)->cur_tb) { |
bd4c625c | 2372 | print_cur_tb("fix_nodes"); |
a063ae17 | 2373 | reiserfs_panic(tb->tb_sb, "PAP-8305", |
c3a9c210 | 2374 | "there is pending do_balance"); |
bd4c625c | 2375 | } |
1da177e4 | 2376 | |
a063ae17 JM |
2377 | if (!buffer_uptodate(tbS0) || !B_IS_IN_TREE(tbS0)) |
2378 | reiserfs_panic(tb->tb_sb, "PAP-8320", "S[0] (%b %z) is " | |
c3a9c210 JM |
2379 | "not uptodate at the beginning of fix_nodes " |
2380 | "or not in tree (mode %c)", | |
ee93961b | 2381 | tbS0, tbS0, op_mode); |
1da177e4 | 2382 | |
bd4c625c | 2383 | /* Check parameters. */ |
ee93961b | 2384 | switch (op_mode) { |
bd4c625c | 2385 | case M_INSERT: |
ee93961b | 2386 | if (item_num <= 0 || item_num > B_NR_ITEMS(tbS0)) |
a063ae17 | 2387 | reiserfs_panic(tb->tb_sb, "PAP-8330", "Incorrect " |
c3a9c210 | 2388 | "item number %d (in S0 - %d) in case " |
ee93961b | 2389 | "of insert", item_num, |
a063ae17 | 2390 | B_NR_ITEMS(tbS0)); |
bd4c625c LT |
2391 | break; |
2392 | case M_PASTE: | |
2393 | case M_DELETE: | |
2394 | case M_CUT: | |
ee93961b | 2395 | if (item_num < 0 || item_num >= B_NR_ITEMS(tbS0)) { |
a063ae17 JM |
2396 | print_block(tbS0, 0, -1, -1); |
2397 | reiserfs_panic(tb->tb_sb, "PAP-8335", "Incorrect " | |
c3a9c210 JM |
2398 | "item number(%d); mode = %c " |
2399 | "insert_size = %d", | |
ee93961b | 2400 | item_num, op_mode, |
a063ae17 | 2401 | tb->insert_size[0]); |
1da177e4 | 2402 | } |
1da177e4 | 2403 | break; |
bd4c625c | 2404 | default: |
a063ae17 | 2405 | reiserfs_panic(tb->tb_sb, "PAP-8340", "Incorrect mode " |
c3a9c210 | 2406 | "of operation"); |
1da177e4 | 2407 | } |
bd4c625c | 2408 | #endif |
1da177e4 | 2409 | |
a063ae17 | 2410 | if (get_mem_for_virtual_node(tb) == REPEAT_SEARCH) |
bd4c625c LT |
2411 | // FIXME: maybe -ENOMEM when tb->vn_buf == 0? Now just repeat |
2412 | return REPEAT_SEARCH; | |
1da177e4 | 2413 | |
ee93961b JM |
2414 | /* Starting from the leaf level; for all levels h of the tree. */ |
2415 | for (h = 0; h < MAX_HEIGHT && tb->insert_size[h]; h++) { | |
2416 | ret = get_direct_parent(tb, h); | |
2417 | if (ret != CARRY_ON) | |
bd4c625c | 2418 | goto repeat; |
1da177e4 | 2419 | |
ee93961b JM |
2420 | ret = check_balance(op_mode, tb, h, item_num, |
2421 | pos_in_item, ins_ih, data); | |
2422 | if (ret != CARRY_ON) { | |
2423 | if (ret == NO_BALANCING_NEEDED) { | |
bd4c625c | 2424 | /* No balancing for higher levels needed. */ |
ee93961b JM |
2425 | ret = get_neighbors(tb, h); |
2426 | if (ret != CARRY_ON) | |
bd4c625c | 2427 | goto repeat; |
ee93961b JM |
2428 | if (h != MAX_HEIGHT - 1) |
2429 | tb->insert_size[h + 1] = 0; | |
bd4c625c LT |
2430 | /* ok, analysis and resource gathering are complete */ |
2431 | break; | |
2432 | } | |
2433 | goto repeat; | |
2434 | } | |
1da177e4 | 2435 | |
ee93961b JM |
2436 | ret = get_neighbors(tb, h); |
2437 | if (ret != CARRY_ON) | |
bd4c625c | 2438 | goto repeat; |
bd4c625c | 2439 | |
a063ae17 JM |
2440 | /* No disk space, or schedule occurred and analysis may be |
2441 | * invalid and needs to be redone. */ | |
ee93961b JM |
2442 | ret = get_empty_nodes(tb, h); |
2443 | if (ret != CARRY_ON) | |
a063ae17 | 2444 | goto repeat; |
bd4c625c | 2445 | |
ee93961b | 2446 | if (!PATH_H_PBUFFER(tb->tb_path, h)) { |
bd4c625c LT |
2447 | /* We have a positive insert size but no nodes exist on this |
2448 | level, this means that we are creating a new root. */ | |
2449 | ||
ee93961b | 2450 | RFALSE(tb->blknum[h] != 1, |
bd4c625c LT |
2451 | "PAP-8350: creating new empty root"); |
2452 | ||
ee93961b JM |
2453 | if (h < MAX_HEIGHT - 1) |
2454 | tb->insert_size[h + 1] = 0; | |
2455 | } else if (!PATH_H_PBUFFER(tb->tb_path, h + 1)) { | |
2456 | if (tb->blknum[h] > 1) { | |
2457 | /* The tree needs to be grown, so this node S[h] | |
bd4c625c | 2458 | which is the root node is split into two nodes, |
ee93961b | 2459 | and a new node (S[h+1]) will be created to |
bd4c625c LT |
2460 | become the root node. */ |
2461 | ||
ee93961b | 2462 | RFALSE(h == MAX_HEIGHT - 1, |
bd4c625c LT |
2463 | "PAP-8355: attempt to create too high of a tree"); |
2464 | ||
ee93961b | 2465 | tb->insert_size[h + 1] = |
bd4c625c | 2466 | (DC_SIZE + |
ee93961b | 2467 | KEY_SIZE) * (tb->blknum[h] - 1) + |
bd4c625c | 2468 | DC_SIZE; |
ee93961b JM |
2469 | } else if (h < MAX_HEIGHT - 1) |
2470 | tb->insert_size[h + 1] = 0; | |
bd4c625c | 2471 | } else |
ee93961b JM |
2472 | tb->insert_size[h + 1] = |
2473 | (DC_SIZE + KEY_SIZE) * (tb->blknum[h] - 1); | |
1da177e4 | 2474 | } |
1da177e4 | 2475 | |
ee93961b JM |
2476 | ret = wait_tb_buffers_until_unlocked(tb); |
2477 | if (ret == CARRY_ON) { | |
a063ae17 | 2478 | if (FILESYSTEM_CHANGED_TB(tb)) { |
bd4c625c | 2479 | wait_tb_buffers_run = 1; |
ee93961b | 2480 | ret = REPEAT_SEARCH; |
bd4c625c LT |
2481 | goto repeat; |
2482 | } else { | |
2483 | return CARRY_ON; | |
2484 | } | |
1da177e4 | 2485 | } else { |
bd4c625c LT |
2486 | wait_tb_buffers_run = 1; |
2487 | goto repeat; | |
1da177e4 LT |
2488 | } |
2489 | ||
bd4c625c LT |
2490 | repeat: |
2491 | // fix_nodes was unable to perform its calculation due to | |
2492 | // filesystem got changed under us, lack of free disk space or i/o | |
2493 | // failure. If the first is the case - the search will be | |
2494 | // repeated. For now - free all resources acquired so far except | |
2495 | // for the new allocated nodes | |
2496 | { | |
2497 | int i; | |
2498 | ||
2499 | /* Release path buffers. */ | |
2500 | if (wait_tb_buffers_run) { | |
a063ae17 | 2501 | pathrelse_and_restore(tb->tb_sb, tb->tb_path); |
bd4c625c | 2502 | } else { |
a063ae17 | 2503 | pathrelse(tb->tb_path); |
bd4c625c LT |
2504 | } |
2505 | /* brelse all resources collected for balancing */ | |
2506 | for (i = 0; i < MAX_HEIGHT; i++) { | |
2507 | if (wait_tb_buffers_run) { | |
a063ae17 JM |
2508 | reiserfs_restore_prepared_buffer(tb->tb_sb, |
2509 | tb->L[i]); | |
2510 | reiserfs_restore_prepared_buffer(tb->tb_sb, | |
2511 | tb->R[i]); | |
2512 | reiserfs_restore_prepared_buffer(tb->tb_sb, | |
2513 | tb->FL[i]); | |
2514 | reiserfs_restore_prepared_buffer(tb->tb_sb, | |
2515 | tb->FR[i]); | |
2516 | reiserfs_restore_prepared_buffer(tb->tb_sb, | |
2517 | tb-> | |
bd4c625c | 2518 | CFL[i]); |
a063ae17 JM |
2519 | reiserfs_restore_prepared_buffer(tb->tb_sb, |
2520 | tb-> | |
bd4c625c LT |
2521 | CFR[i]); |
2522 | } | |
2523 | ||
a063ae17 JM |
2524 | brelse(tb->L[i]); |
2525 | brelse(tb->R[i]); | |
2526 | brelse(tb->FL[i]); | |
2527 | brelse(tb->FR[i]); | |
2528 | brelse(tb->CFL[i]); | |
2529 | brelse(tb->CFR[i]); | |
2530 | ||
2531 | tb->L[i] = NULL; | |
2532 | tb->R[i] = NULL; | |
2533 | tb->FL[i] = NULL; | |
2534 | tb->FR[i] = NULL; | |
2535 | tb->CFL[i] = NULL; | |
2536 | tb->CFR[i] = NULL; | |
bd4c625c LT |
2537 | } |
2538 | ||
2539 | if (wait_tb_buffers_run) { | |
2540 | for (i = 0; i < MAX_FEB_SIZE; i++) { | |
a063ae17 | 2541 | if (tb->FEB[i]) |
bd4c625c | 2542 | reiserfs_restore_prepared_buffer |
a063ae17 | 2543 | (tb->tb_sb, tb->FEB[i]); |
bd4c625c | 2544 | } |
1da177e4 | 2545 | } |
ee93961b | 2546 | return ret; |
1da177e4 | 2547 | } |
1da177e4 LT |
2548 | |
2549 | } | |
2550 | ||
a063ae17 | 2551 | /* Anatoly will probably forgive me renaming tb to tb. I just |
1da177e4 | 2552 | wanted to make lines shorter */ |
bd4c625c | 2553 | void unfix_nodes(struct tree_balance *tb) |
1da177e4 | 2554 | { |
bd4c625c | 2555 | int i; |
1da177e4 | 2556 | |
bd4c625c LT |
2557 | /* Release path buffers. */ |
2558 | pathrelse_and_restore(tb->tb_sb, tb->tb_path); | |
1da177e4 | 2559 | |
bd4c625c LT |
2560 | /* brelse all resources collected for balancing */ |
2561 | for (i = 0; i < MAX_HEIGHT; i++) { | |
2562 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->L[i]); | |
2563 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->R[i]); | |
2564 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FL[i]); | |
2565 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FR[i]); | |
2566 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFL[i]); | |
2567 | reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFR[i]); | |
2568 | ||
2569 | brelse(tb->L[i]); | |
2570 | brelse(tb->R[i]); | |
2571 | brelse(tb->FL[i]); | |
2572 | brelse(tb->FR[i]); | |
2573 | brelse(tb->CFL[i]); | |
2574 | brelse(tb->CFR[i]); | |
2575 | } | |
1da177e4 | 2576 | |
bd4c625c LT |
2577 | /* deal with list of allocated (used and unused) nodes */ |
2578 | for (i = 0; i < MAX_FEB_SIZE; i++) { | |
2579 | if (tb->FEB[i]) { | |
2580 | b_blocknr_t blocknr = tb->FEB[i]->b_blocknr; | |
2581 | /* de-allocated block which was not used by balancing and | |
2582 | bforget about buffer for it */ | |
2583 | brelse(tb->FEB[i]); | |
2584 | reiserfs_free_block(tb->transaction_handle, NULL, | |
2585 | blocknr, 0); | |
2586 | } | |
2587 | if (tb->used[i]) { | |
2588 | /* release used as new nodes including a new root */ | |
2589 | brelse(tb->used[i]); | |
2590 | } | |
2591 | } | |
1da177e4 | 2592 | |
d739b42b | 2593 | kfree(tb->vn_buf); |
1da177e4 | 2594 | |
bd4c625c | 2595 | } |