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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/hfsplus/brec.c | |
4 | * | |
5 | * Copyright (C) 2001 | |
6 | * Brad Boyer (flar@allandria.com) | |
7 | * (C) 2003 Ardis Technologies <roman@ardistech.com> | |
8 | * | |
9 | * Handle individual btree records | |
10 | */ | |
11 | ||
12 | #include "hfsplus_fs.h" | |
13 | #include "hfsplus_raw.h" | |
14 | ||
15 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); | |
16 | static int hfs_brec_update_parent(struct hfs_find_data *fd); | |
17 | static int hfs_btree_inc_height(struct hfs_btree *); | |
18 | ||
19 | /* Get the length and offset of the given record in the given node */ | |
20 | u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) | |
21 | { | |
22 | __be16 retval[2]; | |
23 | u16 dataoff; | |
24 | ||
25 | dataoff = node->tree->node_size - (rec + 2) * 2; | |
26 | hfs_bnode_read(node, retval, dataoff, 4); | |
27 | *off = be16_to_cpu(retval[1]); | |
28 | return be16_to_cpu(retval[0]) - *off; | |
29 | } | |
30 | ||
31 | /* Get the length of the key from a keyed record */ | |
32 | u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) | |
33 | { | |
34 | u16 retval, recoff; | |
35 | ||
36 | if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) | |
37 | return 0; | |
38 | ||
39 | if ((node->type == HFS_NODE_INDEX) && | |
324ef39a VD |
40 | !(node->tree->attributes & HFS_TREE_VARIDXKEYS) && |
41 | (node->tree->cnid != HFSPLUS_ATTR_CNID)) { | |
1da177e4 LT |
42 | retval = node->tree->max_key_len + 2; |
43 | } else { | |
2753cc28 AS |
44 | recoff = hfs_bnode_read_u16(node, |
45 | node->tree->node_size - (rec + 1) * 2); | |
1da177e4 LT |
46 | if (!recoff) |
47 | return 0; | |
aac4e419 | 48 | if (recoff > node->tree->node_size - 2) { |
d6142673 | 49 | pr_err("recoff %d too large\n", recoff); |
aac4e419 NA |
50 | return 0; |
51 | } | |
13571a69 CH |
52 | |
53 | retval = hfs_bnode_read_u16(node, recoff) + 2; | |
54 | if (retval > node->tree->max_key_len + 2) { | |
d6142673 | 55 | pr_err("keylen %d too large\n", |
13571a69 CH |
56 | retval); |
57 | retval = 0; | |
9250f925 | 58 | } |
1da177e4 LT |
59 | } |
60 | return retval; | |
61 | } | |
62 | ||
63 | int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) | |
64 | { | |
65 | struct hfs_btree *tree; | |
66 | struct hfs_bnode *node, *new_node; | |
67 | int size, key_len, rec; | |
68 | int data_off, end_off; | |
69 | int idx_rec_off, data_rec_off, end_rec_off; | |
70 | __be32 cnid; | |
71 | ||
72 | tree = fd->tree; | |
73 | if (!fd->bnode) { | |
74 | if (!tree->root) | |
75 | hfs_btree_inc_height(tree); | |
76 | fd->bnode = hfs_bnode_find(tree, tree->leaf_head); | |
77 | if (IS_ERR(fd->bnode)) | |
78 | return PTR_ERR(fd->bnode); | |
79 | fd->record = -1; | |
80 | } | |
81 | new_node = NULL; | |
82 | key_len = be16_to_cpu(fd->search_key->key_len) + 2; | |
83 | again: | |
84 | /* new record idx and complete record size */ | |
85 | rec = fd->record + 1; | |
86 | size = key_len + entry_len; | |
87 | ||
88 | node = fd->bnode; | |
89 | hfs_bnode_dump(node); | |
90 | /* get last offset */ | |
91 | end_rec_off = tree->node_size - (node->num_recs + 1) * 2; | |
92 | end_off = hfs_bnode_read_u16(node, end_rec_off); | |
93 | end_rec_off -= 2; | |
c2b3e1f7 | 94 | hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", |
2753cc28 | 95 | rec, size, end_off, end_rec_off); |
1da177e4 LT |
96 | if (size > end_rec_off - end_off) { |
97 | if (new_node) | |
98 | panic("not enough room!\n"); | |
99 | new_node = hfs_bnode_split(fd); | |
100 | if (IS_ERR(new_node)) | |
101 | return PTR_ERR(new_node); | |
102 | goto again; | |
103 | } | |
104 | if (node->type == HFS_NODE_LEAF) { | |
105 | tree->leaf_count++; | |
106 | mark_inode_dirty(tree->inode); | |
107 | } | |
108 | node->num_recs++; | |
109 | /* write new last offset */ | |
2753cc28 AS |
110 | hfs_bnode_write_u16(node, |
111 | offsetof(struct hfs_bnode_desc, num_recs), | |
112 | node->num_recs); | |
1da177e4 LT |
113 | hfs_bnode_write_u16(node, end_rec_off, end_off + size); |
114 | data_off = end_off; | |
115 | data_rec_off = end_rec_off + 2; | |
116 | idx_rec_off = tree->node_size - (rec + 1) * 2; | |
117 | if (idx_rec_off == data_rec_off) | |
118 | goto skip; | |
119 | /* move all following entries */ | |
120 | do { | |
121 | data_off = hfs_bnode_read_u16(node, data_rec_off + 2); | |
122 | hfs_bnode_write_u16(node, data_rec_off, data_off + size); | |
123 | data_rec_off += 2; | |
124 | } while (data_rec_off < idx_rec_off); | |
125 | ||
126 | /* move data away */ | |
127 | hfs_bnode_move(node, data_off + size, data_off, | |
128 | end_off - data_off); | |
129 | ||
130 | skip: | |
131 | hfs_bnode_write(node, fd->search_key, data_off, key_len); | |
132 | hfs_bnode_write(node, entry, data_off + key_len, entry_len); | |
133 | hfs_bnode_dump(node); | |
134 | ||
98cf21c6 SA |
135 | /* |
136 | * update parent key if we inserted a key | |
137 | * at the start of the node and it is not the new node | |
138 | */ | |
139 | if (!rec && new_node != node) { | |
140 | hfs_bnode_read_key(node, fd->search_key, data_off + size); | |
141 | hfs_brec_update_parent(fd); | |
142 | } | |
1da177e4 | 143 | |
98cf21c6 | 144 | if (new_node) { |
1da177e4 LT |
145 | hfs_bnode_put(fd->bnode); |
146 | if (!new_node->parent) { | |
147 | hfs_btree_inc_height(tree); | |
148 | new_node->parent = tree->root; | |
149 | } | |
150 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | |
151 | ||
152 | /* create index data entry */ | |
153 | cnid = cpu_to_be32(new_node->this); | |
154 | entry = &cnid; | |
155 | entry_len = sizeof(cnid); | |
156 | ||
157 | /* get index key */ | |
158 | hfs_bnode_read_key(new_node, fd->search_key, 14); | |
324ef39a | 159 | __hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key); |
1da177e4 LT |
160 | |
161 | hfs_bnode_put(new_node); | |
162 | new_node = NULL; | |
163 | ||
324ef39a VD |
164 | if ((tree->attributes & HFS_TREE_VARIDXKEYS) || |
165 | (tree->cnid == HFSPLUS_ATTR_CNID)) | |
1da177e4 LT |
166 | key_len = be16_to_cpu(fd->search_key->key_len) + 2; |
167 | else { | |
2753cc28 AS |
168 | fd->search_key->key_len = |
169 | cpu_to_be16(tree->max_key_len); | |
1da177e4 LT |
170 | key_len = tree->max_key_len + 2; |
171 | } | |
172 | goto again; | |
173 | } | |
174 | ||
1da177e4 LT |
175 | return 0; |
176 | } | |
177 | ||
178 | int hfs_brec_remove(struct hfs_find_data *fd) | |
179 | { | |
180 | struct hfs_btree *tree; | |
181 | struct hfs_bnode *node, *parent; | |
182 | int end_off, rec_off, data_off, size; | |
183 | ||
184 | tree = fd->tree; | |
185 | node = fd->bnode; | |
186 | again: | |
187 | rec_off = tree->node_size - (fd->record + 2) * 2; | |
188 | end_off = tree->node_size - (node->num_recs + 1) * 2; | |
189 | ||
190 | if (node->type == HFS_NODE_LEAF) { | |
191 | tree->leaf_count--; | |
192 | mark_inode_dirty(tree->inode); | |
193 | } | |
194 | hfs_bnode_dump(node); | |
c2b3e1f7 | 195 | hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n", |
2753cc28 | 196 | fd->record, fd->keylength + fd->entrylength); |
1da177e4 LT |
197 | if (!--node->num_recs) { |
198 | hfs_bnode_unlink(node); | |
199 | if (!node->parent) | |
200 | return 0; | |
201 | parent = hfs_bnode_find(tree, node->parent); | |
202 | if (IS_ERR(parent)) | |
203 | return PTR_ERR(parent); | |
204 | hfs_bnode_put(node); | |
205 | node = fd->bnode = parent; | |
206 | ||
324ef39a | 207 | __hfs_brec_find(node, fd, hfs_find_rec_by_key); |
1da177e4 LT |
208 | goto again; |
209 | } | |
2753cc28 AS |
210 | hfs_bnode_write_u16(node, |
211 | offsetof(struct hfs_bnode_desc, num_recs), | |
212 | node->num_recs); | |
1da177e4 LT |
213 | |
214 | if (rec_off == end_off) | |
215 | goto skip; | |
216 | size = fd->keylength + fd->entrylength; | |
217 | ||
218 | do { | |
219 | data_off = hfs_bnode_read_u16(node, rec_off); | |
220 | hfs_bnode_write_u16(node, rec_off + 2, data_off - size); | |
221 | rec_off -= 2; | |
222 | } while (rec_off >= end_off); | |
223 | ||
224 | /* fill hole */ | |
225 | hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, | |
226 | data_off - fd->keyoffset - size); | |
227 | skip: | |
228 | hfs_bnode_dump(node); | |
229 | if (!fd->record) | |
230 | hfs_brec_update_parent(fd); | |
231 | return 0; | |
232 | } | |
233 | ||
234 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) | |
235 | { | |
236 | struct hfs_btree *tree; | |
b6b41424 | 237 | struct hfs_bnode *node, *new_node, *next_node; |
1da177e4 LT |
238 | struct hfs_bnode_desc node_desc; |
239 | int num_recs, new_rec_off, new_off, old_rec_off; | |
240 | int data_start, data_end, size; | |
241 | ||
242 | tree = fd->tree; | |
243 | node = fd->bnode; | |
244 | new_node = hfs_bmap_alloc(tree); | |
245 | if (IS_ERR(new_node)) | |
246 | return new_node; | |
247 | hfs_bnode_get(node); | |
c2b3e1f7 | 248 | hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n", |
1da177e4 LT |
249 | node->this, new_node->this, node->next); |
250 | new_node->next = node->next; | |
251 | new_node->prev = node->this; | |
252 | new_node->parent = node->parent; | |
253 | new_node->type = node->type; | |
254 | new_node->height = node->height; | |
255 | ||
b6b41424 AV |
256 | if (node->next) |
257 | next_node = hfs_bnode_find(tree, node->next); | |
258 | else | |
259 | next_node = NULL; | |
260 | ||
261 | if (IS_ERR(next_node)) { | |
262 | hfs_bnode_put(node); | |
263 | hfs_bnode_put(new_node); | |
264 | return next_node; | |
265 | } | |
266 | ||
1da177e4 LT |
267 | size = tree->node_size / 2 - node->num_recs * 2 - 14; |
268 | old_rec_off = tree->node_size - 4; | |
269 | num_recs = 1; | |
270 | for (;;) { | |
271 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
272 | if (data_start > size) | |
273 | break; | |
274 | old_rec_off -= 2; | |
275 | if (++num_recs < node->num_recs) | |
276 | continue; | |
277 | /* panic? */ | |
278 | hfs_bnode_put(node); | |
279 | hfs_bnode_put(new_node); | |
b6b41424 AV |
280 | if (next_node) |
281 | hfs_bnode_put(next_node); | |
1da177e4 LT |
282 | return ERR_PTR(-ENOSPC); |
283 | } | |
284 | ||
285 | if (fd->record + 1 < num_recs) { | |
286 | /* new record is in the lower half, | |
287 | * so leave some more space there | |
288 | */ | |
289 | old_rec_off += 2; | |
290 | num_recs--; | |
291 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
292 | } else { | |
293 | hfs_bnode_put(node); | |
294 | hfs_bnode_get(new_node); | |
295 | fd->bnode = new_node; | |
296 | fd->record -= num_recs; | |
297 | fd->keyoffset -= data_start - 14; | |
298 | fd->entryoffset -= data_start - 14; | |
299 | } | |
300 | new_node->num_recs = node->num_recs - num_recs; | |
301 | node->num_recs = num_recs; | |
302 | ||
303 | new_rec_off = tree->node_size - 2; | |
304 | new_off = 14; | |
305 | size = data_start - new_off; | |
306 | num_recs = new_node->num_recs; | |
307 | data_end = data_start; | |
308 | while (num_recs) { | |
309 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
310 | old_rec_off -= 2; | |
311 | new_rec_off -= 2; | |
312 | data_end = hfs_bnode_read_u16(node, old_rec_off); | |
313 | new_off = data_end - size; | |
314 | num_recs--; | |
315 | } | |
316 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
317 | hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); | |
318 | ||
319 | /* update new bnode header */ | |
320 | node_desc.next = cpu_to_be32(new_node->next); | |
321 | node_desc.prev = cpu_to_be32(new_node->prev); | |
322 | node_desc.type = new_node->type; | |
323 | node_desc.height = new_node->height; | |
324 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
325 | node_desc.reserved = 0; | |
326 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
327 | ||
328 | /* update previous bnode header */ | |
329 | node->next = new_node->this; | |
330 | hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); | |
331 | node_desc.next = cpu_to_be32(node->next); | |
332 | node_desc.num_recs = cpu_to_be16(node->num_recs); | |
333 | hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); | |
334 | ||
335 | /* update next bnode header */ | |
b6b41424 | 336 | if (next_node) { |
1da177e4 LT |
337 | next_node->prev = new_node->this; |
338 | hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); | |
339 | node_desc.prev = cpu_to_be32(next_node->prev); | |
340 | hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); | |
341 | hfs_bnode_put(next_node); | |
342 | } else if (node->this == tree->leaf_tail) { | |
343 | /* if there is no next node, this might be the new tail */ | |
344 | tree->leaf_tail = new_node->this; | |
345 | mark_inode_dirty(tree->inode); | |
346 | } | |
347 | ||
348 | hfs_bnode_dump(node); | |
349 | hfs_bnode_dump(new_node); | |
350 | hfs_bnode_put(node); | |
351 | ||
352 | return new_node; | |
353 | } | |
354 | ||
355 | static int hfs_brec_update_parent(struct hfs_find_data *fd) | |
356 | { | |
357 | struct hfs_btree *tree; | |
358 | struct hfs_bnode *node, *new_node, *parent; | |
359 | int newkeylen, diff; | |
360 | int rec, rec_off, end_rec_off; | |
361 | int start_off, end_off; | |
362 | ||
363 | tree = fd->tree; | |
364 | node = fd->bnode; | |
365 | new_node = NULL; | |
366 | if (!node->parent) | |
367 | return 0; | |
368 | ||
369 | again: | |
370 | parent = hfs_bnode_find(tree, node->parent); | |
371 | if (IS_ERR(parent)) | |
372 | return PTR_ERR(parent); | |
324ef39a | 373 | __hfs_brec_find(parent, fd, hfs_find_rec_by_key); |
98cf21c6 SA |
374 | if (fd->record < 0) |
375 | return -ENOENT; | |
1da177e4 LT |
376 | hfs_bnode_dump(parent); |
377 | rec = fd->record; | |
378 | ||
379 | /* size difference between old and new key */ | |
324ef39a VD |
380 | if ((tree->attributes & HFS_TREE_VARIDXKEYS) || |
381 | (tree->cnid == HFSPLUS_ATTR_CNID)) | |
1da177e4 LT |
382 | newkeylen = hfs_bnode_read_u16(node, 14) + 2; |
383 | else | |
384 | fd->keylength = newkeylen = tree->max_key_len + 2; | |
c2b3e1f7 | 385 | hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n", |
2753cc28 | 386 | rec, fd->keylength, newkeylen); |
1da177e4 LT |
387 | |
388 | rec_off = tree->node_size - (rec + 2) * 2; | |
389 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | |
390 | diff = newkeylen - fd->keylength; | |
391 | if (!diff) | |
392 | goto skip; | |
393 | if (diff > 0) { | |
394 | end_off = hfs_bnode_read_u16(parent, end_rec_off); | |
395 | if (end_rec_off - end_off < diff) { | |
396 | ||
c2b3e1f7 | 397 | hfs_dbg(BNODE_MOD, "splitting index node\n"); |
1da177e4 LT |
398 | fd->bnode = parent; |
399 | new_node = hfs_bnode_split(fd); | |
400 | if (IS_ERR(new_node)) | |
401 | return PTR_ERR(new_node); | |
402 | parent = fd->bnode; | |
403 | rec = fd->record; | |
404 | rec_off = tree->node_size - (rec + 2) * 2; | |
2753cc28 AS |
405 | end_rec_off = tree->node_size - |
406 | (parent->num_recs + 1) * 2; | |
1da177e4 LT |
407 | } |
408 | } | |
409 | ||
410 | end_off = start_off = hfs_bnode_read_u16(parent, rec_off); | |
411 | hfs_bnode_write_u16(parent, rec_off, start_off + diff); | |
412 | start_off -= 4; /* move previous cnid too */ | |
413 | ||
414 | while (rec_off > end_rec_off) { | |
415 | rec_off -= 2; | |
416 | end_off = hfs_bnode_read_u16(parent, rec_off); | |
417 | hfs_bnode_write_u16(parent, rec_off, end_off + diff); | |
418 | } | |
419 | hfs_bnode_move(parent, start_off + diff, start_off, | |
420 | end_off - start_off); | |
421 | skip: | |
422 | hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); | |
423 | hfs_bnode_dump(parent); | |
424 | ||
425 | hfs_bnode_put(node); | |
426 | node = parent; | |
427 | ||
428 | if (new_node) { | |
429 | __be32 cnid; | |
430 | ||
431 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | |
432 | /* create index key and entry */ | |
433 | hfs_bnode_read_key(new_node, fd->search_key, 14); | |
434 | cnid = cpu_to_be32(new_node->this); | |
435 | ||
324ef39a | 436 | __hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key); |
1da177e4 LT |
437 | hfs_brec_insert(fd, &cnid, sizeof(cnid)); |
438 | hfs_bnode_put(fd->bnode); | |
439 | hfs_bnode_put(new_node); | |
440 | ||
441 | if (!rec) { | |
442 | if (new_node == node) | |
443 | goto out; | |
444 | /* restore search_key */ | |
445 | hfs_bnode_read_key(node, fd->search_key, 14); | |
446 | } | |
447 | } | |
448 | ||
449 | if (!rec && node->parent) | |
450 | goto again; | |
451 | out: | |
452 | fd->bnode = node; | |
453 | return 0; | |
454 | } | |
455 | ||
456 | static int hfs_btree_inc_height(struct hfs_btree *tree) | |
457 | { | |
458 | struct hfs_bnode *node, *new_node; | |
459 | struct hfs_bnode_desc node_desc; | |
460 | int key_size, rec; | |
461 | __be32 cnid; | |
462 | ||
463 | node = NULL; | |
464 | if (tree->root) { | |
465 | node = hfs_bnode_find(tree, tree->root); | |
466 | if (IS_ERR(node)) | |
467 | return PTR_ERR(node); | |
468 | } | |
469 | new_node = hfs_bmap_alloc(tree); | |
470 | if (IS_ERR(new_node)) { | |
471 | hfs_bnode_put(node); | |
472 | return PTR_ERR(new_node); | |
473 | } | |
474 | ||
475 | tree->root = new_node->this; | |
476 | if (!tree->depth) { | |
477 | tree->leaf_head = tree->leaf_tail = new_node->this; | |
478 | new_node->type = HFS_NODE_LEAF; | |
479 | new_node->num_recs = 0; | |
480 | } else { | |
481 | new_node->type = HFS_NODE_INDEX; | |
482 | new_node->num_recs = 1; | |
483 | } | |
484 | new_node->parent = 0; | |
485 | new_node->next = 0; | |
486 | new_node->prev = 0; | |
487 | new_node->height = ++tree->depth; | |
488 | ||
489 | node_desc.next = cpu_to_be32(new_node->next); | |
490 | node_desc.prev = cpu_to_be32(new_node->prev); | |
491 | node_desc.type = new_node->type; | |
492 | node_desc.height = new_node->height; | |
493 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
494 | node_desc.reserved = 0; | |
495 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
496 | ||
497 | rec = tree->node_size - 2; | |
498 | hfs_bnode_write_u16(new_node, rec, 14); | |
499 | ||
500 | if (node) { | |
501 | /* insert old root idx into new root */ | |
502 | node->parent = tree->root; | |
503 | if (node->type == HFS_NODE_LEAF || | |
324ef39a VD |
504 | tree->attributes & HFS_TREE_VARIDXKEYS || |
505 | tree->cnid == HFSPLUS_ATTR_CNID) | |
1da177e4 LT |
506 | key_size = hfs_bnode_read_u16(node, 14) + 2; |
507 | else | |
508 | key_size = tree->max_key_len + 2; | |
509 | hfs_bnode_copy(new_node, 14, node, 14, key_size); | |
510 | ||
324ef39a VD |
511 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS) && |
512 | (tree->cnid != HFSPLUS_ATTR_CNID)) { | |
1da177e4 LT |
513 | key_size = tree->max_key_len + 2; |
514 | hfs_bnode_write_u16(new_node, 14, tree->max_key_len); | |
515 | } | |
516 | cnid = cpu_to_be32(node->this); | |
517 | hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); | |
518 | ||
519 | rec -= 2; | |
520 | hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); | |
521 | ||
522 | hfs_bnode_put(node); | |
523 | } | |
524 | hfs_bnode_put(new_node); | |
525 | mark_inode_dirty(tree->inode); | |
526 | ||
527 | return 0; | |
528 | } |