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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
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; | |
cf059462 | 48 | if (node->tree->attributes & HFS_TREE_BIGKEYS) { |
1da177e4 | 49 | retval = hfs_bnode_read_u16(node, recoff) + 2; |
cf059462 | 50 | if (retval > node->tree->max_key_len + 2) { |
d6142673 | 51 | pr_err("keylen %d too large\n", retval); |
55581d01 | 52 | retval = 0; |
cf059462 ES |
53 | } |
54 | } else { | |
1da177e4 | 55 | retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1; |
cf059462 | 56 | if (retval > node->tree->max_key_len + 1) { |
d6142673 | 57 | pr_err("keylen %d too large\n", retval); |
55581d01 | 58 | retval = 0; |
cf059462 ES |
59 | } |
60 | } | |
1da177e4 LT |
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 | fd->bnode = hfs_bnode_find(tree, tree->leaf_head); | |
79 | if (IS_ERR(fd->bnode)) | |
80 | return PTR_ERR(fd->bnode); | |
81 | fd->record = -1; | |
82 | } | |
83 | new_node = NULL; | |
84 | key_len = (fd->search_key->key_len | 1) + 1; | |
85 | again: | |
86 | /* new record idx and complete record size */ | |
87 | rec = fd->record + 1; | |
88 | size = key_len + entry_len; | |
89 | ||
90 | node = fd->bnode; | |
91 | hfs_bnode_dump(node); | |
92 | /* get last offset */ | |
93 | end_rec_off = tree->node_size - (node->num_recs + 1) * 2; | |
94 | end_off = hfs_bnode_read_u16(node, end_rec_off); | |
95 | end_rec_off -= 2; | |
c2b3e1f7 JP |
96 | hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", |
97 | rec, size, end_off, end_rec_off); | |
1da177e4 LT |
98 | if (size > end_rec_off - end_off) { |
99 | if (new_node) | |
100 | panic("not enough room!\n"); | |
101 | new_node = hfs_bnode_split(fd); | |
102 | if (IS_ERR(new_node)) | |
103 | return PTR_ERR(new_node); | |
104 | goto again; | |
105 | } | |
106 | if (node->type == HFS_NODE_LEAF) { | |
107 | tree->leaf_count++; | |
108 | mark_inode_dirty(tree->inode); | |
109 | } | |
110 | node->num_recs++; | |
111 | /* write new last offset */ | |
112 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | |
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 | ||
b4cc0efe HTL |
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 | |
b4cc0efe | 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); | |
159 | __hfs_brec_find(fd->bnode, fd); | |
160 | ||
161 | hfs_bnode_put(new_node); | |
162 | new_node = NULL; | |
163 | ||
164 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | |
165 | key_len = fd->search_key->key_len + 1; | |
166 | else { | |
167 | fd->search_key->key_len = tree->max_key_len; | |
168 | key_len = tree->max_key_len + 1; | |
169 | } | |
170 | goto again; | |
171 | } | |
172 | ||
1da177e4 LT |
173 | return 0; |
174 | } | |
175 | ||
176 | int hfs_brec_remove(struct hfs_find_data *fd) | |
177 | { | |
178 | struct hfs_btree *tree; | |
179 | struct hfs_bnode *node, *parent; | |
180 | int end_off, rec_off, data_off, size; | |
181 | ||
182 | tree = fd->tree; | |
183 | node = fd->bnode; | |
184 | again: | |
185 | rec_off = tree->node_size - (fd->record + 2) * 2; | |
186 | end_off = tree->node_size - (node->num_recs + 1) * 2; | |
187 | ||
188 | if (node->type == HFS_NODE_LEAF) { | |
189 | tree->leaf_count--; | |
190 | mark_inode_dirty(tree->inode); | |
191 | } | |
192 | hfs_bnode_dump(node); | |
c2b3e1f7 JP |
193 | hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n", |
194 | fd->record, fd->keylength + fd->entrylength); | |
1da177e4 LT |
195 | if (!--node->num_recs) { |
196 | hfs_bnode_unlink(node); | |
197 | if (!node->parent) | |
198 | return 0; | |
199 | parent = hfs_bnode_find(tree, node->parent); | |
200 | if (IS_ERR(parent)) | |
201 | return PTR_ERR(parent); | |
202 | hfs_bnode_put(node); | |
203 | node = fd->bnode = parent; | |
204 | ||
205 | __hfs_brec_find(node, fd); | |
206 | goto again; | |
207 | } | |
208 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | |
209 | ||
210 | if (rec_off == end_off) | |
211 | goto skip; | |
212 | size = fd->keylength + fd->entrylength; | |
213 | ||
214 | do { | |
215 | data_off = hfs_bnode_read_u16(node, rec_off); | |
216 | hfs_bnode_write_u16(node, rec_off + 2, data_off - size); | |
217 | rec_off -= 2; | |
218 | } while (rec_off >= end_off); | |
219 | ||
220 | /* fill hole */ | |
221 | hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, | |
222 | data_off - fd->keyoffset - size); | |
223 | skip: | |
224 | hfs_bnode_dump(node); | |
225 | if (!fd->record) | |
226 | hfs_brec_update_parent(fd); | |
227 | return 0; | |
228 | } | |
229 | ||
230 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) | |
231 | { | |
232 | struct hfs_btree *tree; | |
3d10a15d | 233 | struct hfs_bnode *node, *new_node, *next_node; |
1da177e4 LT |
234 | struct hfs_bnode_desc node_desc; |
235 | int num_recs, new_rec_off, new_off, old_rec_off; | |
236 | int data_start, data_end, size; | |
237 | ||
238 | tree = fd->tree; | |
239 | node = fd->bnode; | |
240 | new_node = hfs_bmap_alloc(tree); | |
241 | if (IS_ERR(new_node)) | |
242 | return new_node; | |
243 | hfs_bnode_get(node); | |
c2b3e1f7 | 244 | hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n", |
1da177e4 LT |
245 | node->this, new_node->this, node->next); |
246 | new_node->next = node->next; | |
247 | new_node->prev = node->this; | |
248 | new_node->parent = node->parent; | |
249 | new_node->type = node->type; | |
250 | new_node->height = node->height; | |
251 | ||
3d10a15d AV |
252 | if (node->next) |
253 | next_node = hfs_bnode_find(tree, node->next); | |
254 | else | |
255 | next_node = NULL; | |
256 | ||
257 | if (IS_ERR(next_node)) { | |
258 | hfs_bnode_put(node); | |
259 | hfs_bnode_put(new_node); | |
260 | return next_node; | |
261 | } | |
262 | ||
1da177e4 LT |
263 | size = tree->node_size / 2 - node->num_recs * 2 - 14; |
264 | old_rec_off = tree->node_size - 4; | |
265 | num_recs = 1; | |
266 | for (;;) { | |
267 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
268 | if (data_start > size) | |
269 | break; | |
270 | old_rec_off -= 2; | |
271 | if (++num_recs < node->num_recs) | |
272 | continue; | |
273 | /* panic? */ | |
274 | hfs_bnode_put(node); | |
275 | hfs_bnode_put(new_node); | |
3d10a15d AV |
276 | if (next_node) |
277 | hfs_bnode_put(next_node); | |
1da177e4 LT |
278 | return ERR_PTR(-ENOSPC); |
279 | } | |
280 | ||
281 | if (fd->record + 1 < num_recs) { | |
282 | /* new record is in the lower half, | |
283 | * so leave some more space there | |
284 | */ | |
285 | old_rec_off += 2; | |
286 | num_recs--; | |
287 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
288 | } else { | |
289 | hfs_bnode_put(node); | |
290 | hfs_bnode_get(new_node); | |
291 | fd->bnode = new_node; | |
292 | fd->record -= num_recs; | |
293 | fd->keyoffset -= data_start - 14; | |
294 | fd->entryoffset -= data_start - 14; | |
295 | } | |
296 | new_node->num_recs = node->num_recs - num_recs; | |
297 | node->num_recs = num_recs; | |
298 | ||
299 | new_rec_off = tree->node_size - 2; | |
300 | new_off = 14; | |
301 | size = data_start - new_off; | |
302 | num_recs = new_node->num_recs; | |
303 | data_end = data_start; | |
304 | while (num_recs) { | |
305 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
306 | old_rec_off -= 2; | |
307 | new_rec_off -= 2; | |
308 | data_end = hfs_bnode_read_u16(node, old_rec_off); | |
309 | new_off = data_end - size; | |
310 | num_recs--; | |
311 | } | |
312 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
313 | hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); | |
314 | ||
315 | /* update new bnode header */ | |
316 | node_desc.next = cpu_to_be32(new_node->next); | |
317 | node_desc.prev = cpu_to_be32(new_node->prev); | |
318 | node_desc.type = new_node->type; | |
319 | node_desc.height = new_node->height; | |
320 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
321 | node_desc.reserved = 0; | |
322 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
323 | ||
324 | /* update previous bnode header */ | |
325 | node->next = new_node->this; | |
326 | hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); | |
327 | node_desc.next = cpu_to_be32(node->next); | |
328 | node_desc.num_recs = cpu_to_be16(node->num_recs); | |
329 | hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); | |
330 | ||
331 | /* update next bnode header */ | |
3d10a15d | 332 | if (next_node) { |
1da177e4 LT |
333 | next_node->prev = new_node->this; |
334 | hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); | |
335 | node_desc.prev = cpu_to_be32(next_node->prev); | |
336 | hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); | |
337 | hfs_bnode_put(next_node); | |
338 | } else if (node->this == tree->leaf_tail) { | |
339 | /* if there is no next node, this might be the new tail */ | |
340 | tree->leaf_tail = new_node->this; | |
341 | mark_inode_dirty(tree->inode); | |
342 | } | |
343 | ||
344 | hfs_bnode_dump(node); | |
345 | hfs_bnode_dump(new_node); | |
346 | hfs_bnode_put(node); | |
347 | ||
348 | return new_node; | |
349 | } | |
350 | ||
351 | static int hfs_brec_update_parent(struct hfs_find_data *fd) | |
352 | { | |
353 | struct hfs_btree *tree; | |
354 | struct hfs_bnode *node, *new_node, *parent; | |
355 | int newkeylen, diff; | |
356 | int rec, rec_off, end_rec_off; | |
357 | int start_off, end_off; | |
358 | ||
359 | tree = fd->tree; | |
360 | node = fd->bnode; | |
361 | new_node = NULL; | |
362 | if (!node->parent) | |
363 | return 0; | |
364 | ||
365 | again: | |
366 | parent = hfs_bnode_find(tree, node->parent); | |
367 | if (IS_ERR(parent)) | |
368 | return PTR_ERR(parent); | |
369 | __hfs_brec_find(parent, fd); | |
b4cc0efe HTL |
370 | if (fd->record < 0) |
371 | return -ENOENT; | |
1da177e4 LT |
372 | hfs_bnode_dump(parent); |
373 | rec = fd->record; | |
374 | ||
375 | /* size difference between old and new key */ | |
376 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | |
377 | newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1; | |
378 | else | |
379 | fd->keylength = newkeylen = tree->max_key_len + 1; | |
c2b3e1f7 JP |
380 | hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n", |
381 | rec, fd->keylength, newkeylen); | |
1da177e4 LT |
382 | |
383 | rec_off = tree->node_size - (rec + 2) * 2; | |
384 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | |
385 | diff = newkeylen - fd->keylength; | |
386 | if (!diff) | |
387 | goto skip; | |
388 | if (diff > 0) { | |
389 | end_off = hfs_bnode_read_u16(parent, end_rec_off); | |
390 | if (end_rec_off - end_off < diff) { | |
391 | ||
d6142673 | 392 | printk(KERN_DEBUG "splitting index node...\n"); |
1da177e4 LT |
393 | fd->bnode = parent; |
394 | new_node = hfs_bnode_split(fd); | |
395 | if (IS_ERR(new_node)) | |
396 | return PTR_ERR(new_node); | |
397 | parent = fd->bnode; | |
398 | rec = fd->record; | |
399 | rec_off = tree->node_size - (rec + 2) * 2; | |
400 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | |
401 | } | |
402 | } | |
403 | ||
404 | end_off = start_off = hfs_bnode_read_u16(parent, rec_off); | |
405 | hfs_bnode_write_u16(parent, rec_off, start_off + diff); | |
406 | start_off -= 4; /* move previous cnid too */ | |
407 | ||
408 | while (rec_off > end_rec_off) { | |
409 | rec_off -= 2; | |
410 | end_off = hfs_bnode_read_u16(parent, rec_off); | |
411 | hfs_bnode_write_u16(parent, rec_off, end_off + diff); | |
412 | } | |
413 | hfs_bnode_move(parent, start_off + diff, start_off, | |
414 | end_off - start_off); | |
415 | skip: | |
416 | hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); | |
417 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) | |
418 | hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1); | |
419 | hfs_bnode_dump(parent); | |
420 | ||
421 | hfs_bnode_put(node); | |
422 | node = parent; | |
423 | ||
424 | if (new_node) { | |
425 | __be32 cnid; | |
426 | ||
427 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | |
428 | /* create index key and entry */ | |
429 | hfs_bnode_read_key(new_node, fd->search_key, 14); | |
430 | cnid = cpu_to_be32(new_node->this); | |
431 | ||
432 | __hfs_brec_find(fd->bnode, fd); | |
433 | hfs_brec_insert(fd, &cnid, sizeof(cnid)); | |
434 | hfs_bnode_put(fd->bnode); | |
435 | hfs_bnode_put(new_node); | |
436 | ||
437 | if (!rec) { | |
438 | if (new_node == node) | |
439 | goto out; | |
440 | /* restore search_key */ | |
441 | hfs_bnode_read_key(node, fd->search_key, 14); | |
442 | } | |
443 | } | |
444 | ||
445 | if (!rec && node->parent) | |
446 | goto again; | |
447 | out: | |
448 | fd->bnode = node; | |
449 | return 0; | |
450 | } | |
451 | ||
452 | static int hfs_btree_inc_height(struct hfs_btree *tree) | |
453 | { | |
454 | struct hfs_bnode *node, *new_node; | |
455 | struct hfs_bnode_desc node_desc; | |
456 | int key_size, rec; | |
457 | __be32 cnid; | |
458 | ||
459 | node = NULL; | |
460 | if (tree->root) { | |
461 | node = hfs_bnode_find(tree, tree->root); | |
462 | if (IS_ERR(node)) | |
463 | return PTR_ERR(node); | |
464 | } | |
465 | new_node = hfs_bmap_alloc(tree); | |
466 | if (IS_ERR(new_node)) { | |
467 | hfs_bnode_put(node); | |
468 | return PTR_ERR(new_node); | |
469 | } | |
470 | ||
471 | tree->root = new_node->this; | |
472 | if (!tree->depth) { | |
473 | tree->leaf_head = tree->leaf_tail = new_node->this; | |
474 | new_node->type = HFS_NODE_LEAF; | |
475 | new_node->num_recs = 0; | |
476 | } else { | |
477 | new_node->type = HFS_NODE_INDEX; | |
478 | new_node->num_recs = 1; | |
479 | } | |
480 | new_node->parent = 0; | |
481 | new_node->next = 0; | |
482 | new_node->prev = 0; | |
483 | new_node->height = ++tree->depth; | |
484 | ||
485 | node_desc.next = cpu_to_be32(new_node->next); | |
486 | node_desc.prev = cpu_to_be32(new_node->prev); | |
487 | node_desc.type = new_node->type; | |
488 | node_desc.height = new_node->height; | |
489 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
490 | node_desc.reserved = 0; | |
491 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
492 | ||
493 | rec = tree->node_size - 2; | |
494 | hfs_bnode_write_u16(new_node, rec, 14); | |
495 | ||
496 | if (node) { | |
497 | /* insert old root idx into new root */ | |
498 | node->parent = tree->root; | |
499 | if (node->type == HFS_NODE_LEAF || | |
500 | tree->attributes & HFS_TREE_VARIDXKEYS) | |
501 | key_size = hfs_bnode_read_u8(node, 14) + 1; | |
502 | else | |
503 | key_size = tree->max_key_len + 1; | |
504 | hfs_bnode_copy(new_node, 14, node, 14, key_size); | |
505 | ||
506 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { | |
507 | key_size = tree->max_key_len + 1; | |
508 | hfs_bnode_write_u8(new_node, 14, tree->max_key_len); | |
509 | } | |
510 | key_size = (key_size + 1) & -2; | |
511 | cnid = cpu_to_be32(node->this); | |
512 | hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); | |
513 | ||
514 | rec -= 2; | |
515 | hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); | |
516 | ||
517 | hfs_bnode_put(node); | |
518 | } | |
519 | hfs_bnode_put(new_node); | |
520 | mark_inode_dirty(tree->inode); | |
521 | ||
522 | return 0; | |
523 | } |