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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/hfs/brec.c | |
3 | * | |
4 | * Copyright (C) 2001 | |
5 | * Brad Boyer (flar@allandria.com) | |
6 | * (C) 2003 Ardis Technologies <roman@ardistech.com> | |
7 | * | |
8 | * Handle individual btree records | |
9 | */ | |
10 | ||
11 | #include "btree.h" | |
12 | ||
13 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); | |
14 | static int hfs_brec_update_parent(struct hfs_find_data *fd); | |
15 | static int hfs_btree_inc_height(struct hfs_btree *tree); | |
16 | ||
17 | /* Get the length and offset of the given record in the given node */ | |
18 | u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) | |
19 | { | |
20 | __be16 retval[2]; | |
21 | u16 dataoff; | |
22 | ||
23 | dataoff = node->tree->node_size - (rec + 2) * 2; | |
24 | hfs_bnode_read(node, retval, dataoff, 4); | |
25 | *off = be16_to_cpu(retval[1]); | |
26 | return be16_to_cpu(retval[0]) - *off; | |
27 | } | |
28 | ||
29 | /* Get the length of the key from a keyed record */ | |
30 | u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) | |
31 | { | |
32 | u16 retval, recoff; | |
33 | ||
34 | if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) | |
35 | return 0; | |
36 | ||
37 | if ((node->type == HFS_NODE_INDEX) && | |
38 | !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) { | |
39 | if (node->tree->attributes & HFS_TREE_BIGKEYS) | |
40 | retval = node->tree->max_key_len + 2; | |
41 | else | |
42 | retval = node->tree->max_key_len + 1; | |
43 | } else { | |
44 | recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2); | |
45 | if (!recoff) | |
46 | return 0; | |
47 | if (node->tree->attributes & HFS_TREE_BIGKEYS) | |
48 | retval = hfs_bnode_read_u16(node, recoff) + 2; | |
49 | else | |
50 | retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1; | |
51 | } | |
52 | return retval; | |
53 | } | |
54 | ||
55 | int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) | |
56 | { | |
57 | struct hfs_btree *tree; | |
58 | struct hfs_bnode *node, *new_node; | |
59 | int size, key_len, rec; | |
60 | int data_off, end_off; | |
61 | int idx_rec_off, data_rec_off, end_rec_off; | |
62 | __be32 cnid; | |
63 | ||
64 | tree = fd->tree; | |
65 | if (!fd->bnode) { | |
66 | if (!tree->root) | |
67 | hfs_btree_inc_height(tree); | |
68 | fd->bnode = hfs_bnode_find(tree, tree->leaf_head); | |
69 | if (IS_ERR(fd->bnode)) | |
70 | return PTR_ERR(fd->bnode); | |
71 | fd->record = -1; | |
72 | } | |
73 | new_node = NULL; | |
74 | key_len = (fd->search_key->key_len | 1) + 1; | |
75 | again: | |
76 | /* new record idx and complete record size */ | |
77 | rec = fd->record + 1; | |
78 | size = key_len + entry_len; | |
79 | ||
80 | node = fd->bnode; | |
81 | hfs_bnode_dump(node); | |
82 | /* get last offset */ | |
83 | end_rec_off = tree->node_size - (node->num_recs + 1) * 2; | |
84 | end_off = hfs_bnode_read_u16(node, end_rec_off); | |
85 | end_rec_off -= 2; | |
86 | dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off); | |
87 | if (size > end_rec_off - end_off) { | |
88 | if (new_node) | |
89 | panic("not enough room!\n"); | |
90 | new_node = hfs_bnode_split(fd); | |
91 | if (IS_ERR(new_node)) | |
92 | return PTR_ERR(new_node); | |
93 | goto again; | |
94 | } | |
95 | if (node->type == HFS_NODE_LEAF) { | |
96 | tree->leaf_count++; | |
97 | mark_inode_dirty(tree->inode); | |
98 | } | |
99 | node->num_recs++; | |
100 | /* write new last offset */ | |
101 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | |
102 | hfs_bnode_write_u16(node, end_rec_off, end_off + size); | |
103 | data_off = end_off; | |
104 | data_rec_off = end_rec_off + 2; | |
105 | idx_rec_off = tree->node_size - (rec + 1) * 2; | |
106 | if (idx_rec_off == data_rec_off) | |
107 | goto skip; | |
108 | /* move all following entries */ | |
109 | do { | |
110 | data_off = hfs_bnode_read_u16(node, data_rec_off + 2); | |
111 | hfs_bnode_write_u16(node, data_rec_off, data_off + size); | |
112 | data_rec_off += 2; | |
113 | } while (data_rec_off < idx_rec_off); | |
114 | ||
115 | /* move data away */ | |
116 | hfs_bnode_move(node, data_off + size, data_off, | |
117 | end_off - data_off); | |
118 | ||
119 | skip: | |
120 | hfs_bnode_write(node, fd->search_key, data_off, key_len); | |
121 | hfs_bnode_write(node, entry, data_off + key_len, entry_len); | |
122 | hfs_bnode_dump(node); | |
123 | ||
124 | if (new_node) { | |
125 | /* update parent key if we inserted a key | |
126 | * at the start of the first node | |
127 | */ | |
128 | if (!rec && new_node != node) | |
129 | hfs_brec_update_parent(fd); | |
130 | ||
131 | hfs_bnode_put(fd->bnode); | |
132 | if (!new_node->parent) { | |
133 | hfs_btree_inc_height(tree); | |
134 | new_node->parent = tree->root; | |
135 | } | |
136 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | |
137 | ||
138 | /* create index data entry */ | |
139 | cnid = cpu_to_be32(new_node->this); | |
140 | entry = &cnid; | |
141 | entry_len = sizeof(cnid); | |
142 | ||
143 | /* get index key */ | |
144 | hfs_bnode_read_key(new_node, fd->search_key, 14); | |
145 | __hfs_brec_find(fd->bnode, fd); | |
146 | ||
147 | hfs_bnode_put(new_node); | |
148 | new_node = NULL; | |
149 | ||
150 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | |
151 | key_len = fd->search_key->key_len + 1; | |
152 | else { | |
153 | fd->search_key->key_len = tree->max_key_len; | |
154 | key_len = tree->max_key_len + 1; | |
155 | } | |
156 | goto again; | |
157 | } | |
158 | ||
159 | if (!rec) | |
160 | hfs_brec_update_parent(fd); | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | int hfs_brec_remove(struct hfs_find_data *fd) | |
166 | { | |
167 | struct hfs_btree *tree; | |
168 | struct hfs_bnode *node, *parent; | |
169 | int end_off, rec_off, data_off, size; | |
170 | ||
171 | tree = fd->tree; | |
172 | node = fd->bnode; | |
173 | again: | |
174 | rec_off = tree->node_size - (fd->record + 2) * 2; | |
175 | end_off = tree->node_size - (node->num_recs + 1) * 2; | |
176 | ||
177 | if (node->type == HFS_NODE_LEAF) { | |
178 | tree->leaf_count--; | |
179 | mark_inode_dirty(tree->inode); | |
180 | } | |
181 | hfs_bnode_dump(node); | |
182 | dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength); | |
183 | if (!--node->num_recs) { | |
184 | hfs_bnode_unlink(node); | |
185 | if (!node->parent) | |
186 | return 0; | |
187 | parent = hfs_bnode_find(tree, node->parent); | |
188 | if (IS_ERR(parent)) | |
189 | return PTR_ERR(parent); | |
190 | hfs_bnode_put(node); | |
191 | node = fd->bnode = parent; | |
192 | ||
193 | __hfs_brec_find(node, fd); | |
194 | goto again; | |
195 | } | |
196 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | |
197 | ||
198 | if (rec_off == end_off) | |
199 | goto skip; | |
200 | size = fd->keylength + fd->entrylength; | |
201 | ||
202 | do { | |
203 | data_off = hfs_bnode_read_u16(node, rec_off); | |
204 | hfs_bnode_write_u16(node, rec_off + 2, data_off - size); | |
205 | rec_off -= 2; | |
206 | } while (rec_off >= end_off); | |
207 | ||
208 | /* fill hole */ | |
209 | hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, | |
210 | data_off - fd->keyoffset - size); | |
211 | skip: | |
212 | hfs_bnode_dump(node); | |
213 | if (!fd->record) | |
214 | hfs_brec_update_parent(fd); | |
215 | return 0; | |
216 | } | |
217 | ||
218 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) | |
219 | { | |
220 | struct hfs_btree *tree; | |
221 | struct hfs_bnode *node, *new_node; | |
222 | struct hfs_bnode_desc node_desc; | |
223 | int num_recs, new_rec_off, new_off, old_rec_off; | |
224 | int data_start, data_end, size; | |
225 | ||
226 | tree = fd->tree; | |
227 | node = fd->bnode; | |
228 | new_node = hfs_bmap_alloc(tree); | |
229 | if (IS_ERR(new_node)) | |
230 | return new_node; | |
231 | hfs_bnode_get(node); | |
232 | dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n", | |
233 | node->this, new_node->this, node->next); | |
234 | new_node->next = node->next; | |
235 | new_node->prev = node->this; | |
236 | new_node->parent = node->parent; | |
237 | new_node->type = node->type; | |
238 | new_node->height = node->height; | |
239 | ||
240 | size = tree->node_size / 2 - node->num_recs * 2 - 14; | |
241 | old_rec_off = tree->node_size - 4; | |
242 | num_recs = 1; | |
243 | for (;;) { | |
244 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
245 | if (data_start > size) | |
246 | break; | |
247 | old_rec_off -= 2; | |
248 | if (++num_recs < node->num_recs) | |
249 | continue; | |
250 | /* panic? */ | |
251 | hfs_bnode_put(node); | |
252 | hfs_bnode_put(new_node); | |
253 | return ERR_PTR(-ENOSPC); | |
254 | } | |
255 | ||
256 | if (fd->record + 1 < num_recs) { | |
257 | /* new record is in the lower half, | |
258 | * so leave some more space there | |
259 | */ | |
260 | old_rec_off += 2; | |
261 | num_recs--; | |
262 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
263 | } else { | |
264 | hfs_bnode_put(node); | |
265 | hfs_bnode_get(new_node); | |
266 | fd->bnode = new_node; | |
267 | fd->record -= num_recs; | |
268 | fd->keyoffset -= data_start - 14; | |
269 | fd->entryoffset -= data_start - 14; | |
270 | } | |
271 | new_node->num_recs = node->num_recs - num_recs; | |
272 | node->num_recs = num_recs; | |
273 | ||
274 | new_rec_off = tree->node_size - 2; | |
275 | new_off = 14; | |
276 | size = data_start - new_off; | |
277 | num_recs = new_node->num_recs; | |
278 | data_end = data_start; | |
279 | while (num_recs) { | |
280 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
281 | old_rec_off -= 2; | |
282 | new_rec_off -= 2; | |
283 | data_end = hfs_bnode_read_u16(node, old_rec_off); | |
284 | new_off = data_end - size; | |
285 | num_recs--; | |
286 | } | |
287 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
288 | hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); | |
289 | ||
290 | /* update new bnode header */ | |
291 | node_desc.next = cpu_to_be32(new_node->next); | |
292 | node_desc.prev = cpu_to_be32(new_node->prev); | |
293 | node_desc.type = new_node->type; | |
294 | node_desc.height = new_node->height; | |
295 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
296 | node_desc.reserved = 0; | |
297 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
298 | ||
299 | /* update previous bnode header */ | |
300 | node->next = new_node->this; | |
301 | hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); | |
302 | node_desc.next = cpu_to_be32(node->next); | |
303 | node_desc.num_recs = cpu_to_be16(node->num_recs); | |
304 | hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); | |
305 | ||
306 | /* update next bnode header */ | |
307 | if (new_node->next) { | |
308 | struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next); | |
309 | next_node->prev = new_node->this; | |
310 | hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); | |
311 | node_desc.prev = cpu_to_be32(next_node->prev); | |
312 | hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); | |
313 | hfs_bnode_put(next_node); | |
314 | } else if (node->this == tree->leaf_tail) { | |
315 | /* if there is no next node, this might be the new tail */ | |
316 | tree->leaf_tail = new_node->this; | |
317 | mark_inode_dirty(tree->inode); | |
318 | } | |
319 | ||
320 | hfs_bnode_dump(node); | |
321 | hfs_bnode_dump(new_node); | |
322 | hfs_bnode_put(node); | |
323 | ||
324 | return new_node; | |
325 | } | |
326 | ||
327 | static int hfs_brec_update_parent(struct hfs_find_data *fd) | |
328 | { | |
329 | struct hfs_btree *tree; | |
330 | struct hfs_bnode *node, *new_node, *parent; | |
331 | int newkeylen, diff; | |
332 | int rec, rec_off, end_rec_off; | |
333 | int start_off, end_off; | |
334 | ||
335 | tree = fd->tree; | |
336 | node = fd->bnode; | |
337 | new_node = NULL; | |
338 | if (!node->parent) | |
339 | return 0; | |
340 | ||
341 | again: | |
342 | parent = hfs_bnode_find(tree, node->parent); | |
343 | if (IS_ERR(parent)) | |
344 | return PTR_ERR(parent); | |
345 | __hfs_brec_find(parent, fd); | |
346 | hfs_bnode_dump(parent); | |
347 | rec = fd->record; | |
348 | ||
349 | /* size difference between old and new key */ | |
350 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | |
351 | newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1; | |
352 | else | |
353 | fd->keylength = newkeylen = tree->max_key_len + 1; | |
354 | dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen); | |
355 | ||
356 | rec_off = tree->node_size - (rec + 2) * 2; | |
357 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | |
358 | diff = newkeylen - fd->keylength; | |
359 | if (!diff) | |
360 | goto skip; | |
361 | if (diff > 0) { | |
362 | end_off = hfs_bnode_read_u16(parent, end_rec_off); | |
363 | if (end_rec_off - end_off < diff) { | |
364 | ||
7cf3cc30 | 365 | printk(KERN_DEBUG "hfs: splitting index node...\n"); |
1da177e4 LT |
366 | fd->bnode = parent; |
367 | new_node = hfs_bnode_split(fd); | |
368 | if (IS_ERR(new_node)) | |
369 | return PTR_ERR(new_node); | |
370 | parent = fd->bnode; | |
371 | rec = fd->record; | |
372 | rec_off = tree->node_size - (rec + 2) * 2; | |
373 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | |
374 | } | |
375 | } | |
376 | ||
377 | end_off = start_off = hfs_bnode_read_u16(parent, rec_off); | |
378 | hfs_bnode_write_u16(parent, rec_off, start_off + diff); | |
379 | start_off -= 4; /* move previous cnid too */ | |
380 | ||
381 | while (rec_off > end_rec_off) { | |
382 | rec_off -= 2; | |
383 | end_off = hfs_bnode_read_u16(parent, rec_off); | |
384 | hfs_bnode_write_u16(parent, rec_off, end_off + diff); | |
385 | } | |
386 | hfs_bnode_move(parent, start_off + diff, start_off, | |
387 | end_off - start_off); | |
388 | skip: | |
389 | hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); | |
390 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) | |
391 | hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1); | |
392 | hfs_bnode_dump(parent); | |
393 | ||
394 | hfs_bnode_put(node); | |
395 | node = parent; | |
396 | ||
397 | if (new_node) { | |
398 | __be32 cnid; | |
399 | ||
400 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | |
401 | /* create index key and entry */ | |
402 | hfs_bnode_read_key(new_node, fd->search_key, 14); | |
403 | cnid = cpu_to_be32(new_node->this); | |
404 | ||
405 | __hfs_brec_find(fd->bnode, fd); | |
406 | hfs_brec_insert(fd, &cnid, sizeof(cnid)); | |
407 | hfs_bnode_put(fd->bnode); | |
408 | hfs_bnode_put(new_node); | |
409 | ||
410 | if (!rec) { | |
411 | if (new_node == node) | |
412 | goto out; | |
413 | /* restore search_key */ | |
414 | hfs_bnode_read_key(node, fd->search_key, 14); | |
415 | } | |
416 | } | |
417 | ||
418 | if (!rec && node->parent) | |
419 | goto again; | |
420 | out: | |
421 | fd->bnode = node; | |
422 | return 0; | |
423 | } | |
424 | ||
425 | static int hfs_btree_inc_height(struct hfs_btree *tree) | |
426 | { | |
427 | struct hfs_bnode *node, *new_node; | |
428 | struct hfs_bnode_desc node_desc; | |
429 | int key_size, rec; | |
430 | __be32 cnid; | |
431 | ||
432 | node = NULL; | |
433 | if (tree->root) { | |
434 | node = hfs_bnode_find(tree, tree->root); | |
435 | if (IS_ERR(node)) | |
436 | return PTR_ERR(node); | |
437 | } | |
438 | new_node = hfs_bmap_alloc(tree); | |
439 | if (IS_ERR(new_node)) { | |
440 | hfs_bnode_put(node); | |
441 | return PTR_ERR(new_node); | |
442 | } | |
443 | ||
444 | tree->root = new_node->this; | |
445 | if (!tree->depth) { | |
446 | tree->leaf_head = tree->leaf_tail = new_node->this; | |
447 | new_node->type = HFS_NODE_LEAF; | |
448 | new_node->num_recs = 0; | |
449 | } else { | |
450 | new_node->type = HFS_NODE_INDEX; | |
451 | new_node->num_recs = 1; | |
452 | } | |
453 | new_node->parent = 0; | |
454 | new_node->next = 0; | |
455 | new_node->prev = 0; | |
456 | new_node->height = ++tree->depth; | |
457 | ||
458 | node_desc.next = cpu_to_be32(new_node->next); | |
459 | node_desc.prev = cpu_to_be32(new_node->prev); | |
460 | node_desc.type = new_node->type; | |
461 | node_desc.height = new_node->height; | |
462 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
463 | node_desc.reserved = 0; | |
464 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
465 | ||
466 | rec = tree->node_size - 2; | |
467 | hfs_bnode_write_u16(new_node, rec, 14); | |
468 | ||
469 | if (node) { | |
470 | /* insert old root idx into new root */ | |
471 | node->parent = tree->root; | |
472 | if (node->type == HFS_NODE_LEAF || | |
473 | tree->attributes & HFS_TREE_VARIDXKEYS) | |
474 | key_size = hfs_bnode_read_u8(node, 14) + 1; | |
475 | else | |
476 | key_size = tree->max_key_len + 1; | |
477 | hfs_bnode_copy(new_node, 14, node, 14, key_size); | |
478 | ||
479 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { | |
480 | key_size = tree->max_key_len + 1; | |
481 | hfs_bnode_write_u8(new_node, 14, tree->max_key_len); | |
482 | } | |
483 | key_size = (key_size + 1) & -2; | |
484 | cnid = cpu_to_be32(node->this); | |
485 | hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); | |
486 | ||
487 | rec -= 2; | |
488 | hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); | |
489 | ||
490 | hfs_bnode_put(node); | |
491 | } | |
492 | hfs_bnode_put(new_node); | |
493 | mark_inode_dirty(tree->inode); | |
494 | ||
495 | return 0; | |
496 | } |