1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/fs/hfs/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 "btree.h" |
13 | |
14 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); |
15 | static int hfs_brec_update_parent(struct hfs_find_data *fd); |
16 | static int hfs_btree_inc_height(struct hfs_btree *tree); |
17 | |
18 | /* Get the length and offset of the given record in the given node */ |
19 | u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) |
20 | { |
21 | __be16 retval[2]; |
22 | u16 dataoff; |
23 | |
24 | dataoff = node->tree->node_size - (rec + 2) * 2; |
25 | hfs_bnode_read(node, retval, dataoff, 4); |
26 | *off = be16_to_cpu(retval[1]); |
27 | return be16_to_cpu(retval[0]) - *off; |
28 | } |
29 | |
30 | /* Get the length of the key from a keyed record */ |
31 | u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) |
32 | { |
33 | u16 retval, recoff; |
34 | |
35 | if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) |
36 | return 0; |
37 | |
38 | if ((node->type == HFS_NODE_INDEX) && |
39 | !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) { |
40 | if (node->tree->attributes & HFS_TREE_BIGKEYS) |
41 | retval = node->tree->max_key_len + 2; |
42 | else |
43 | retval = node->tree->max_key_len + 1; |
44 | } else { |
45 | recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2); |
46 | if (!recoff) |
47 | return 0; |
48 | if (node->tree->attributes & HFS_TREE_BIGKEYS) { |
49 | retval = hfs_bnode_read_u16(node, recoff) + 2; |
50 | if (retval > node->tree->max_key_len + 2) { |
51 | pr_err("keylen %d too large\n" , retval); |
52 | retval = 0; |
53 | } |
54 | } else { |
55 | retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1; |
56 | if (retval > node->tree->max_key_len + 1) { |
57 | pr_err("keylen %d too large\n" , retval); |
58 | retval = 0; |
59 | } |
60 | } |
61 | } |
62 | return retval; |
63 | } |
64 | |
65 | int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) |
66 | { |
67 | struct hfs_btree *tree; |
68 | struct hfs_bnode *node, *new_node; |
69 | int size, key_len, rec; |
70 | int data_off, end_off; |
71 | int idx_rec_off, data_rec_off, end_rec_off; |
72 | __be32 cnid; |
73 | |
74 | tree = fd->tree; |
75 | if (!fd->bnode) { |
76 | if (!tree->root) |
77 | hfs_btree_inc_height(tree); |
78 | node = hfs_bnode_find(tree, tree->leaf_head); |
79 | if (IS_ERR(ptr: node)) |
80 | return PTR_ERR(ptr: node); |
81 | fd->bnode = node; |
82 | fd->record = -1; |
83 | } |
84 | new_node = NULL; |
85 | key_len = (fd->search_key->key_len | 1) + 1; |
86 | again: |
87 | /* new record idx and complete record size */ |
88 | rec = fd->record + 1; |
89 | size = key_len + entry_len; |
90 | |
91 | node = fd->bnode; |
92 | hfs_bnode_dump(node); |
93 | /* get last offset */ |
94 | end_rec_off = tree->node_size - (node->num_recs + 1) * 2; |
95 | end_off = hfs_bnode_read_u16(node, end_rec_off); |
96 | end_rec_off -= 2; |
97 | hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n" , |
98 | rec, size, end_off, end_rec_off); |
99 | if (size > end_rec_off - end_off) { |
100 | if (new_node) |
101 | panic(fmt: "not enough room!\n" ); |
102 | new_node = hfs_bnode_split(fd); |
103 | if (IS_ERR(ptr: new_node)) |
104 | return PTR_ERR(ptr: new_node); |
105 | goto again; |
106 | } |
107 | if (node->type == HFS_NODE_LEAF) { |
108 | tree->leaf_count++; |
109 | mark_inode_dirty(inode: tree->inode); |
110 | } |
111 | node->num_recs++; |
112 | /* write new last offset */ |
113 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); |
114 | hfs_bnode_write_u16(node, end_rec_off, end_off + size); |
115 | data_off = end_off; |
116 | data_rec_off = end_rec_off + 2; |
117 | idx_rec_off = tree->node_size - (rec + 1) * 2; |
118 | if (idx_rec_off == data_rec_off) |
119 | goto skip; |
120 | /* move all following entries */ |
121 | do { |
122 | data_off = hfs_bnode_read_u16(node, data_rec_off + 2); |
123 | hfs_bnode_write_u16(node, data_rec_off, data_off + size); |
124 | data_rec_off += 2; |
125 | } while (data_rec_off < idx_rec_off); |
126 | |
127 | /* move data away */ |
128 | hfs_bnode_move(node, data_off + size, data_off, |
129 | end_off - data_off); |
130 | |
131 | skip: |
132 | hfs_bnode_write(node, fd->search_key, data_off, key_len); |
133 | hfs_bnode_write(node, entry, data_off + key_len, entry_len); |
134 | hfs_bnode_dump(node); |
135 | |
136 | /* |
137 | * update parent key if we inserted a key |
138 | * at the start of the node and it is not the new node |
139 | */ |
140 | if (!rec && new_node != node) { |
141 | hfs_bnode_read_key(node, fd->search_key, data_off + size); |
142 | hfs_brec_update_parent(fd); |
143 | } |
144 | |
145 | if (new_node) { |
146 | hfs_bnode_put(fd->bnode); |
147 | if (!new_node->parent) { |
148 | hfs_btree_inc_height(tree); |
149 | new_node->parent = tree->root; |
150 | } |
151 | fd->bnode = hfs_bnode_find(tree, new_node->parent); |
152 | |
153 | /* create index data entry */ |
154 | cnid = cpu_to_be32(new_node->this); |
155 | entry = &cnid; |
156 | entry_len = sizeof(cnid); |
157 | |
158 | /* get index key */ |
159 | hfs_bnode_read_key(new_node, fd->search_key, 14); |
160 | __hfs_brec_find(fd->bnode, fd); |
161 | |
162 | hfs_bnode_put(new_node); |
163 | new_node = NULL; |
164 | |
165 | if (tree->attributes & HFS_TREE_VARIDXKEYS) |
166 | key_len = fd->search_key->key_len + 1; |
167 | else { |
168 | fd->search_key->key_len = tree->max_key_len; |
169 | key_len = tree->max_key_len + 1; |
170 | } |
171 | goto again; |
172 | } |
173 | |
174 | return 0; |
175 | } |
176 | |
177 | int hfs_brec_remove(struct hfs_find_data *fd) |
178 | { |
179 | struct hfs_btree *tree; |
180 | struct hfs_bnode *node, *parent; |
181 | int end_off, rec_off, data_off, size; |
182 | |
183 | tree = fd->tree; |
184 | node = fd->bnode; |
185 | again: |
186 | rec_off = tree->node_size - (fd->record + 2) * 2; |
187 | end_off = tree->node_size - (node->num_recs + 1) * 2; |
188 | |
189 | if (node->type == HFS_NODE_LEAF) { |
190 | tree->leaf_count--; |
191 | mark_inode_dirty(inode: tree->inode); |
192 | } |
193 | hfs_bnode_dump(node); |
194 | hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n" , |
195 | fd->record, fd->keylength + fd->entrylength); |
196 | if (!--node->num_recs) { |
197 | hfs_bnode_unlink(node); |
198 | if (!node->parent) |
199 | return 0; |
200 | parent = hfs_bnode_find(tree, node->parent); |
201 | if (IS_ERR(ptr: parent)) |
202 | return PTR_ERR(ptr: parent); |
203 | hfs_bnode_put(node); |
204 | node = fd->bnode = parent; |
205 | |
206 | __hfs_brec_find(node, fd); |
207 | goto again; |
208 | } |
209 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); |
210 | |
211 | if (rec_off == end_off) |
212 | goto skip; |
213 | size = fd->keylength + fd->entrylength; |
214 | |
215 | do { |
216 | data_off = hfs_bnode_read_u16(node, rec_off); |
217 | hfs_bnode_write_u16(node, rec_off + 2, data_off - size); |
218 | rec_off -= 2; |
219 | } while (rec_off >= end_off); |
220 | |
221 | /* fill hole */ |
222 | hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, |
223 | data_off - fd->keyoffset - size); |
224 | skip: |
225 | hfs_bnode_dump(node); |
226 | if (!fd->record) |
227 | hfs_brec_update_parent(fd); |
228 | return 0; |
229 | } |
230 | |
231 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) |
232 | { |
233 | struct hfs_btree *tree; |
234 | struct hfs_bnode *node, *new_node, *next_node; |
235 | struct hfs_bnode_desc node_desc; |
236 | int num_recs, new_rec_off, new_off, old_rec_off; |
237 | int data_start, data_end, size; |
238 | |
239 | tree = fd->tree; |
240 | node = fd->bnode; |
241 | new_node = hfs_bmap_alloc(tree); |
242 | if (IS_ERR(ptr: new_node)) |
243 | return new_node; |
244 | hfs_bnode_get(node); |
245 | hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n" , |
246 | node->this, new_node->this, node->next); |
247 | new_node->next = node->next; |
248 | new_node->prev = node->this; |
249 | new_node->parent = node->parent; |
250 | new_node->type = node->type; |
251 | new_node->height = node->height; |
252 | |
253 | if (node->next) |
254 | next_node = hfs_bnode_find(tree, node->next); |
255 | else |
256 | next_node = NULL; |
257 | |
258 | if (IS_ERR(ptr: next_node)) { |
259 | hfs_bnode_put(node); |
260 | hfs_bnode_put(new_node); |
261 | return next_node; |
262 | } |
263 | |
264 | size = tree->node_size / 2 - node->num_recs * 2 - 14; |
265 | old_rec_off = tree->node_size - 4; |
266 | num_recs = 1; |
267 | for (;;) { |
268 | data_start = hfs_bnode_read_u16(node, old_rec_off); |
269 | if (data_start > size) |
270 | break; |
271 | old_rec_off -= 2; |
272 | if (++num_recs < node->num_recs) |
273 | continue; |
274 | /* panic? */ |
275 | hfs_bnode_put(node); |
276 | hfs_bnode_put(new_node); |
277 | if (next_node) |
278 | hfs_bnode_put(next_node); |
279 | return ERR_PTR(error: -ENOSPC); |
280 | } |
281 | |
282 | if (fd->record + 1 < num_recs) { |
283 | /* new record is in the lower half, |
284 | * so leave some more space there |
285 | */ |
286 | old_rec_off += 2; |
287 | num_recs--; |
288 | data_start = hfs_bnode_read_u16(node, old_rec_off); |
289 | } else { |
290 | hfs_bnode_put(node); |
291 | hfs_bnode_get(new_node); |
292 | fd->bnode = new_node; |
293 | fd->record -= num_recs; |
294 | fd->keyoffset -= data_start - 14; |
295 | fd->entryoffset -= data_start - 14; |
296 | } |
297 | new_node->num_recs = node->num_recs - num_recs; |
298 | node->num_recs = num_recs; |
299 | |
300 | new_rec_off = tree->node_size - 2; |
301 | new_off = 14; |
302 | size = data_start - new_off; |
303 | num_recs = new_node->num_recs; |
304 | data_end = data_start; |
305 | while (num_recs) { |
306 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); |
307 | old_rec_off -= 2; |
308 | new_rec_off -= 2; |
309 | data_end = hfs_bnode_read_u16(node, old_rec_off); |
310 | new_off = data_end - size; |
311 | num_recs--; |
312 | } |
313 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); |
314 | hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); |
315 | |
316 | /* update new bnode header */ |
317 | node_desc.next = cpu_to_be32(new_node->next); |
318 | node_desc.prev = cpu_to_be32(new_node->prev); |
319 | node_desc.type = new_node->type; |
320 | node_desc.height = new_node->height; |
321 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); |
322 | node_desc.reserved = 0; |
323 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); |
324 | |
325 | /* update previous bnode header */ |
326 | node->next = new_node->this; |
327 | hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); |
328 | node_desc.next = cpu_to_be32(node->next); |
329 | node_desc.num_recs = cpu_to_be16(node->num_recs); |
330 | hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); |
331 | |
332 | /* update next bnode header */ |
333 | if (next_node) { |
334 | next_node->prev = new_node->this; |
335 | hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); |
336 | node_desc.prev = cpu_to_be32(next_node->prev); |
337 | hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); |
338 | hfs_bnode_put(next_node); |
339 | } else if (node->this == tree->leaf_tail) { |
340 | /* if there is no next node, this might be the new tail */ |
341 | tree->leaf_tail = new_node->this; |
342 | mark_inode_dirty(inode: tree->inode); |
343 | } |
344 | |
345 | hfs_bnode_dump(node); |
346 | hfs_bnode_dump(new_node); |
347 | hfs_bnode_put(node); |
348 | |
349 | return new_node; |
350 | } |
351 | |
352 | static int hfs_brec_update_parent(struct hfs_find_data *fd) |
353 | { |
354 | struct hfs_btree *tree; |
355 | struct hfs_bnode *node, *new_node, *parent; |
356 | int newkeylen, diff; |
357 | int rec, rec_off, end_rec_off; |
358 | int start_off, end_off; |
359 | |
360 | tree = fd->tree; |
361 | node = fd->bnode; |
362 | new_node = NULL; |
363 | if (!node->parent) |
364 | return 0; |
365 | |
366 | again: |
367 | parent = hfs_bnode_find(tree, node->parent); |
368 | if (IS_ERR(ptr: parent)) |
369 | return PTR_ERR(ptr: parent); |
370 | __hfs_brec_find(parent, fd); |
371 | if (fd->record < 0) |
372 | return -ENOENT; |
373 | hfs_bnode_dump(parent); |
374 | rec = fd->record; |
375 | |
376 | /* size difference between old and new key */ |
377 | if (tree->attributes & HFS_TREE_VARIDXKEYS) |
378 | newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1; |
379 | else |
380 | fd->keylength = newkeylen = tree->max_key_len + 1; |
381 | hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n" , |
382 | rec, fd->keylength, newkeylen); |
383 | |
384 | rec_off = tree->node_size - (rec + 2) * 2; |
385 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; |
386 | diff = newkeylen - fd->keylength; |
387 | if (!diff) |
388 | goto skip; |
389 | if (diff > 0) { |
390 | end_off = hfs_bnode_read_u16(parent, end_rec_off); |
391 | if (end_rec_off - end_off < diff) { |
392 | |
393 | printk(KERN_DEBUG "splitting index node...\n" ); |
394 | fd->bnode = parent; |
395 | new_node = hfs_bnode_split(fd); |
396 | if (IS_ERR(ptr: new_node)) |
397 | return PTR_ERR(ptr: new_node); |
398 | parent = fd->bnode; |
399 | rec = fd->record; |
400 | rec_off = tree->node_size - (rec + 2) * 2; |
401 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; |
402 | } |
403 | } |
404 | |
405 | end_off = start_off = hfs_bnode_read_u16(parent, rec_off); |
406 | hfs_bnode_write_u16(parent, rec_off, start_off + diff); |
407 | start_off -= 4; /* move previous cnid too */ |
408 | |
409 | while (rec_off > end_rec_off) { |
410 | rec_off -= 2; |
411 | end_off = hfs_bnode_read_u16(parent, rec_off); |
412 | hfs_bnode_write_u16(parent, rec_off, end_off + diff); |
413 | } |
414 | hfs_bnode_move(parent, start_off + diff, start_off, |
415 | end_off - start_off); |
416 | skip: |
417 | hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); |
418 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) |
419 | hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1); |
420 | hfs_bnode_dump(parent); |
421 | |
422 | hfs_bnode_put(node); |
423 | node = parent; |
424 | |
425 | if (new_node) { |
426 | __be32 cnid; |
427 | |
428 | if (!new_node->parent) { |
429 | hfs_btree_inc_height(tree); |
430 | new_node->parent = tree->root; |
431 | } |
432 | fd->bnode = hfs_bnode_find(tree, new_node->parent); |
433 | /* create index key and entry */ |
434 | hfs_bnode_read_key(new_node, fd->search_key, 14); |
435 | cnid = cpu_to_be32(new_node->this); |
436 | |
437 | __hfs_brec_find(fd->bnode, fd); |
438 | hfs_brec_insert(fd, entry: &cnid, entry_len: sizeof(cnid)); |
439 | hfs_bnode_put(fd->bnode); |
440 | hfs_bnode_put(new_node); |
441 | |
442 | if (!rec) { |
443 | if (new_node == node) |
444 | goto out; |
445 | /* restore search_key */ |
446 | hfs_bnode_read_key(node, fd->search_key, 14); |
447 | } |
448 | new_node = NULL; |
449 | } |
450 | |
451 | if (!rec && node->parent) |
452 | goto again; |
453 | out: |
454 | fd->bnode = node; |
455 | return 0; |
456 | } |
457 | |
458 | static int hfs_btree_inc_height(struct hfs_btree *tree) |
459 | { |
460 | struct hfs_bnode *node, *new_node; |
461 | struct hfs_bnode_desc node_desc; |
462 | int key_size, rec; |
463 | __be32 cnid; |
464 | |
465 | node = NULL; |
466 | if (tree->root) { |
467 | node = hfs_bnode_find(tree, tree->root); |
468 | if (IS_ERR(ptr: node)) |
469 | return PTR_ERR(ptr: node); |
470 | } |
471 | new_node = hfs_bmap_alloc(tree); |
472 | if (IS_ERR(ptr: new_node)) { |
473 | hfs_bnode_put(node); |
474 | return PTR_ERR(ptr: new_node); |
475 | } |
476 | |
477 | tree->root = new_node->this; |
478 | if (!tree->depth) { |
479 | tree->leaf_head = tree->leaf_tail = new_node->this; |
480 | new_node->type = HFS_NODE_LEAF; |
481 | new_node->num_recs = 0; |
482 | } else { |
483 | new_node->type = HFS_NODE_INDEX; |
484 | new_node->num_recs = 1; |
485 | } |
486 | new_node->parent = 0; |
487 | new_node->next = 0; |
488 | new_node->prev = 0; |
489 | new_node->height = ++tree->depth; |
490 | |
491 | node_desc.next = cpu_to_be32(new_node->next); |
492 | node_desc.prev = cpu_to_be32(new_node->prev); |
493 | node_desc.type = new_node->type; |
494 | node_desc.height = new_node->height; |
495 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); |
496 | node_desc.reserved = 0; |
497 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); |
498 | |
499 | rec = tree->node_size - 2; |
500 | hfs_bnode_write_u16(new_node, rec, 14); |
501 | |
502 | if (node) { |
503 | /* insert old root idx into new root */ |
504 | node->parent = tree->root; |
505 | if (node->type == HFS_NODE_LEAF || |
506 | tree->attributes & HFS_TREE_VARIDXKEYS) |
507 | key_size = hfs_bnode_read_u8(node, 14) + 1; |
508 | else |
509 | key_size = tree->max_key_len + 1; |
510 | hfs_bnode_copy(new_node, 14, node, 14, key_size); |
511 | |
512 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { |
513 | key_size = tree->max_key_len + 1; |
514 | hfs_bnode_write_u8(new_node, 14, tree->max_key_len); |
515 | } |
516 | key_size = (key_size + 1) & -2; |
517 | cnid = cpu_to_be32(node->this); |
518 | hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); |
519 | |
520 | rec -= 2; |
521 | hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); |
522 | |
523 | hfs_bnode_put(node); |
524 | } |
525 | hfs_bnode_put(new_node); |
526 | mark_inode_dirty(inode: tree->inode); |
527 | |
528 | return 0; |
529 | } |
530 | |