]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/hfsplus/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 "hfsplus_fs.h" | |
12 | #include "hfsplus_raw.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 *); | |
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 | retval = node->tree->max_key_len + 2; | |
41 | } else { | |
42 | recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2); | |
43 | if (!recoff) | |
44 | return 0; | |
13571a69 CH |
45 | |
46 | retval = hfs_bnode_read_u16(node, recoff) + 2; | |
47 | if (retval > node->tree->max_key_len + 2) { | |
48 | printk(KERN_ERR "hfs: keylen %d too large\n", | |
49 | retval); | |
50 | retval = 0; | |
9250f925 | 51 | } |
1da177e4 LT |
52 | } |
53 | return retval; | |
54 | } | |
55 | ||
56 | int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) | |
57 | { | |
58 | struct hfs_btree *tree; | |
59 | struct hfs_bnode *node, *new_node; | |
60 | int size, key_len, rec; | |
61 | int data_off, end_off; | |
62 | int idx_rec_off, data_rec_off, end_rec_off; | |
63 | __be32 cnid; | |
64 | ||
65 | tree = fd->tree; | |
66 | if (!fd->bnode) { | |
67 | if (!tree->root) | |
68 | hfs_btree_inc_height(tree); | |
69 | fd->bnode = hfs_bnode_find(tree, tree->leaf_head); | |
70 | if (IS_ERR(fd->bnode)) | |
71 | return PTR_ERR(fd->bnode); | |
72 | fd->record = -1; | |
73 | } | |
74 | new_node = NULL; | |
75 | key_len = be16_to_cpu(fd->search_key->key_len) + 2; | |
76 | again: | |
77 | /* new record idx and complete record size */ | |
78 | rec = fd->record + 1; | |
79 | size = key_len + entry_len; | |
80 | ||
81 | node = fd->bnode; | |
82 | hfs_bnode_dump(node); | |
83 | /* get last offset */ | |
84 | end_rec_off = tree->node_size - (node->num_recs + 1) * 2; | |
85 | end_off = hfs_bnode_read_u16(node, end_rec_off); | |
86 | end_rec_off -= 2; | |
87 | dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off); | |
88 | if (size > end_rec_off - end_off) { | |
89 | if (new_node) | |
90 | panic("not enough room!\n"); | |
91 | new_node = hfs_bnode_split(fd); | |
92 | if (IS_ERR(new_node)) | |
93 | return PTR_ERR(new_node); | |
94 | goto again; | |
95 | } | |
96 | if (node->type == HFS_NODE_LEAF) { | |
97 | tree->leaf_count++; | |
98 | mark_inode_dirty(tree->inode); | |
99 | } | |
100 | node->num_recs++; | |
101 | /* write new last offset */ | |
102 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | |
103 | hfs_bnode_write_u16(node, end_rec_off, end_off + size); | |
104 | data_off = end_off; | |
105 | data_rec_off = end_rec_off + 2; | |
106 | idx_rec_off = tree->node_size - (rec + 1) * 2; | |
107 | if (idx_rec_off == data_rec_off) | |
108 | goto skip; | |
109 | /* move all following entries */ | |
110 | do { | |
111 | data_off = hfs_bnode_read_u16(node, data_rec_off + 2); | |
112 | hfs_bnode_write_u16(node, data_rec_off, data_off + size); | |
113 | data_rec_off += 2; | |
114 | } while (data_rec_off < idx_rec_off); | |
115 | ||
116 | /* move data away */ | |
117 | hfs_bnode_move(node, data_off + size, data_off, | |
118 | end_off - data_off); | |
119 | ||
120 | skip: | |
121 | hfs_bnode_write(node, fd->search_key, data_off, key_len); | |
122 | hfs_bnode_write(node, entry, data_off + key_len, entry_len); | |
123 | hfs_bnode_dump(node); | |
124 | ||
125 | if (new_node) { | |
126 | /* update parent key if we inserted a key | |
127 | * at the start of the first node | |
128 | */ | |
129 | if (!rec && new_node != node) | |
130 | hfs_brec_update_parent(fd); | |
131 | ||
132 | hfs_bnode_put(fd->bnode); | |
133 | if (!new_node->parent) { | |
134 | hfs_btree_inc_height(tree); | |
135 | new_node->parent = tree->root; | |
136 | } | |
137 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | |
138 | ||
139 | /* create index data entry */ | |
140 | cnid = cpu_to_be32(new_node->this); | |
141 | entry = &cnid; | |
142 | entry_len = sizeof(cnid); | |
143 | ||
144 | /* get index key */ | |
145 | hfs_bnode_read_key(new_node, fd->search_key, 14); | |
146 | __hfs_brec_find(fd->bnode, fd); | |
147 | ||
148 | hfs_bnode_put(new_node); | |
149 | new_node = NULL; | |
150 | ||
151 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | |
152 | key_len = be16_to_cpu(fd->search_key->key_len) + 2; | |
153 | else { | |
154 | fd->search_key->key_len = cpu_to_be16(tree->max_key_len); | |
155 | key_len = tree->max_key_len + 2; | |
156 | } | |
157 | goto again; | |
158 | } | |
159 | ||
160 | if (!rec) | |
161 | hfs_brec_update_parent(fd); | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
166 | int hfs_brec_remove(struct hfs_find_data *fd) | |
167 | { | |
168 | struct hfs_btree *tree; | |
169 | struct hfs_bnode *node, *parent; | |
170 | int end_off, rec_off, data_off, size; | |
171 | ||
172 | tree = fd->tree; | |
173 | node = fd->bnode; | |
174 | again: | |
175 | rec_off = tree->node_size - (fd->record + 2) * 2; | |
176 | end_off = tree->node_size - (node->num_recs + 1) * 2; | |
177 | ||
178 | if (node->type == HFS_NODE_LEAF) { | |
179 | tree->leaf_count--; | |
180 | mark_inode_dirty(tree->inode); | |
181 | } | |
182 | hfs_bnode_dump(node); | |
183 | dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength); | |
184 | if (!--node->num_recs) { | |
185 | hfs_bnode_unlink(node); | |
186 | if (!node->parent) | |
187 | return 0; | |
188 | parent = hfs_bnode_find(tree, node->parent); | |
189 | if (IS_ERR(parent)) | |
190 | return PTR_ERR(parent); | |
191 | hfs_bnode_put(node); | |
192 | node = fd->bnode = parent; | |
193 | ||
194 | __hfs_brec_find(node, fd); | |
195 | goto again; | |
196 | } | |
197 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | |
198 | ||
199 | if (rec_off == end_off) | |
200 | goto skip; | |
201 | size = fd->keylength + fd->entrylength; | |
202 | ||
203 | do { | |
204 | data_off = hfs_bnode_read_u16(node, rec_off); | |
205 | hfs_bnode_write_u16(node, rec_off + 2, data_off - size); | |
206 | rec_off -= 2; | |
207 | } while (rec_off >= end_off); | |
208 | ||
209 | /* fill hole */ | |
210 | hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, | |
211 | data_off - fd->keyoffset - size); | |
212 | skip: | |
213 | hfs_bnode_dump(node); | |
214 | if (!fd->record) | |
215 | hfs_brec_update_parent(fd); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) | |
220 | { | |
221 | struct hfs_btree *tree; | |
b6b41424 | 222 | struct hfs_bnode *node, *new_node, *next_node; |
1da177e4 LT |
223 | struct hfs_bnode_desc node_desc; |
224 | int num_recs, new_rec_off, new_off, old_rec_off; | |
225 | int data_start, data_end, size; | |
226 | ||
227 | tree = fd->tree; | |
228 | node = fd->bnode; | |
229 | new_node = hfs_bmap_alloc(tree); | |
230 | if (IS_ERR(new_node)) | |
231 | return new_node; | |
232 | hfs_bnode_get(node); | |
233 | dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n", | |
234 | node->this, new_node->this, node->next); | |
235 | new_node->next = node->next; | |
236 | new_node->prev = node->this; | |
237 | new_node->parent = node->parent; | |
238 | new_node->type = node->type; | |
239 | new_node->height = node->height; | |
240 | ||
b6b41424 AV |
241 | if (node->next) |
242 | next_node = hfs_bnode_find(tree, node->next); | |
243 | else | |
244 | next_node = NULL; | |
245 | ||
246 | if (IS_ERR(next_node)) { | |
247 | hfs_bnode_put(node); | |
248 | hfs_bnode_put(new_node); | |
249 | return next_node; | |
250 | } | |
251 | ||
1da177e4 LT |
252 | size = tree->node_size / 2 - node->num_recs * 2 - 14; |
253 | old_rec_off = tree->node_size - 4; | |
254 | num_recs = 1; | |
255 | for (;;) { | |
256 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
257 | if (data_start > size) | |
258 | break; | |
259 | old_rec_off -= 2; | |
260 | if (++num_recs < node->num_recs) | |
261 | continue; | |
262 | /* panic? */ | |
263 | hfs_bnode_put(node); | |
264 | hfs_bnode_put(new_node); | |
b6b41424 AV |
265 | if (next_node) |
266 | hfs_bnode_put(next_node); | |
1da177e4 LT |
267 | return ERR_PTR(-ENOSPC); |
268 | } | |
269 | ||
270 | if (fd->record + 1 < num_recs) { | |
271 | /* new record is in the lower half, | |
272 | * so leave some more space there | |
273 | */ | |
274 | old_rec_off += 2; | |
275 | num_recs--; | |
276 | data_start = hfs_bnode_read_u16(node, old_rec_off); | |
277 | } else { | |
278 | hfs_bnode_put(node); | |
279 | hfs_bnode_get(new_node); | |
280 | fd->bnode = new_node; | |
281 | fd->record -= num_recs; | |
282 | fd->keyoffset -= data_start - 14; | |
283 | fd->entryoffset -= data_start - 14; | |
284 | } | |
285 | new_node->num_recs = node->num_recs - num_recs; | |
286 | node->num_recs = num_recs; | |
287 | ||
288 | new_rec_off = tree->node_size - 2; | |
289 | new_off = 14; | |
290 | size = data_start - new_off; | |
291 | num_recs = new_node->num_recs; | |
292 | data_end = data_start; | |
293 | while (num_recs) { | |
294 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
295 | old_rec_off -= 2; | |
296 | new_rec_off -= 2; | |
297 | data_end = hfs_bnode_read_u16(node, old_rec_off); | |
298 | new_off = data_end - size; | |
299 | num_recs--; | |
300 | } | |
301 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | |
302 | hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); | |
303 | ||
304 | /* update new bnode header */ | |
305 | node_desc.next = cpu_to_be32(new_node->next); | |
306 | node_desc.prev = cpu_to_be32(new_node->prev); | |
307 | node_desc.type = new_node->type; | |
308 | node_desc.height = new_node->height; | |
309 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
310 | node_desc.reserved = 0; | |
311 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
312 | ||
313 | /* update previous bnode header */ | |
314 | node->next = new_node->this; | |
315 | hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); | |
316 | node_desc.next = cpu_to_be32(node->next); | |
317 | node_desc.num_recs = cpu_to_be16(node->num_recs); | |
318 | hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); | |
319 | ||
320 | /* update next bnode header */ | |
b6b41424 | 321 | if (next_node) { |
1da177e4 LT |
322 | next_node->prev = new_node->this; |
323 | hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); | |
324 | node_desc.prev = cpu_to_be32(next_node->prev); | |
325 | hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); | |
326 | hfs_bnode_put(next_node); | |
327 | } else if (node->this == tree->leaf_tail) { | |
328 | /* if there is no next node, this might be the new tail */ | |
329 | tree->leaf_tail = new_node->this; | |
330 | mark_inode_dirty(tree->inode); | |
331 | } | |
332 | ||
333 | hfs_bnode_dump(node); | |
334 | hfs_bnode_dump(new_node); | |
335 | hfs_bnode_put(node); | |
336 | ||
337 | return new_node; | |
338 | } | |
339 | ||
340 | static int hfs_brec_update_parent(struct hfs_find_data *fd) | |
341 | { | |
342 | struct hfs_btree *tree; | |
343 | struct hfs_bnode *node, *new_node, *parent; | |
344 | int newkeylen, diff; | |
345 | int rec, rec_off, end_rec_off; | |
346 | int start_off, end_off; | |
347 | ||
348 | tree = fd->tree; | |
349 | node = fd->bnode; | |
350 | new_node = NULL; | |
351 | if (!node->parent) | |
352 | return 0; | |
353 | ||
354 | again: | |
355 | parent = hfs_bnode_find(tree, node->parent); | |
356 | if (IS_ERR(parent)) | |
357 | return PTR_ERR(parent); | |
358 | __hfs_brec_find(parent, fd); | |
359 | hfs_bnode_dump(parent); | |
360 | rec = fd->record; | |
361 | ||
362 | /* size difference between old and new key */ | |
363 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | |
364 | newkeylen = hfs_bnode_read_u16(node, 14) + 2; | |
365 | else | |
366 | fd->keylength = newkeylen = tree->max_key_len + 2; | |
367 | dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen); | |
368 | ||
369 | rec_off = tree->node_size - (rec + 2) * 2; | |
370 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | |
371 | diff = newkeylen - fd->keylength; | |
372 | if (!diff) | |
373 | goto skip; | |
374 | if (diff > 0) { | |
375 | end_off = hfs_bnode_read_u16(parent, end_rec_off); | |
376 | if (end_rec_off - end_off < diff) { | |
377 | ||
6d1bbfc4 | 378 | dprint(DBG_BNODE_MOD, "hfs: splitting index node.\n"); |
1da177e4 LT |
379 | fd->bnode = parent; |
380 | new_node = hfs_bnode_split(fd); | |
381 | if (IS_ERR(new_node)) | |
382 | return PTR_ERR(new_node); | |
383 | parent = fd->bnode; | |
384 | rec = fd->record; | |
385 | rec_off = tree->node_size - (rec + 2) * 2; | |
386 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | |
387 | } | |
388 | } | |
389 | ||
390 | end_off = start_off = hfs_bnode_read_u16(parent, rec_off); | |
391 | hfs_bnode_write_u16(parent, rec_off, start_off + diff); | |
392 | start_off -= 4; /* move previous cnid too */ | |
393 | ||
394 | while (rec_off > end_rec_off) { | |
395 | rec_off -= 2; | |
396 | end_off = hfs_bnode_read_u16(parent, rec_off); | |
397 | hfs_bnode_write_u16(parent, rec_off, end_off + diff); | |
398 | } | |
399 | hfs_bnode_move(parent, start_off + diff, start_off, | |
400 | end_off - start_off); | |
401 | skip: | |
402 | hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); | |
403 | hfs_bnode_dump(parent); | |
404 | ||
405 | hfs_bnode_put(node); | |
406 | node = parent; | |
407 | ||
408 | if (new_node) { | |
409 | __be32 cnid; | |
410 | ||
411 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | |
412 | /* create index key and entry */ | |
413 | hfs_bnode_read_key(new_node, fd->search_key, 14); | |
414 | cnid = cpu_to_be32(new_node->this); | |
415 | ||
416 | __hfs_brec_find(fd->bnode, fd); | |
417 | hfs_brec_insert(fd, &cnid, sizeof(cnid)); | |
418 | hfs_bnode_put(fd->bnode); | |
419 | hfs_bnode_put(new_node); | |
420 | ||
421 | if (!rec) { | |
422 | if (new_node == node) | |
423 | goto out; | |
424 | /* restore search_key */ | |
425 | hfs_bnode_read_key(node, fd->search_key, 14); | |
426 | } | |
427 | } | |
428 | ||
429 | if (!rec && node->parent) | |
430 | goto again; | |
431 | out: | |
432 | fd->bnode = node; | |
433 | return 0; | |
434 | } | |
435 | ||
436 | static int hfs_btree_inc_height(struct hfs_btree *tree) | |
437 | { | |
438 | struct hfs_bnode *node, *new_node; | |
439 | struct hfs_bnode_desc node_desc; | |
440 | int key_size, rec; | |
441 | __be32 cnid; | |
442 | ||
443 | node = NULL; | |
444 | if (tree->root) { | |
445 | node = hfs_bnode_find(tree, tree->root); | |
446 | if (IS_ERR(node)) | |
447 | return PTR_ERR(node); | |
448 | } | |
449 | new_node = hfs_bmap_alloc(tree); | |
450 | if (IS_ERR(new_node)) { | |
451 | hfs_bnode_put(node); | |
452 | return PTR_ERR(new_node); | |
453 | } | |
454 | ||
455 | tree->root = new_node->this; | |
456 | if (!tree->depth) { | |
457 | tree->leaf_head = tree->leaf_tail = new_node->this; | |
458 | new_node->type = HFS_NODE_LEAF; | |
459 | new_node->num_recs = 0; | |
460 | } else { | |
461 | new_node->type = HFS_NODE_INDEX; | |
462 | new_node->num_recs = 1; | |
463 | } | |
464 | new_node->parent = 0; | |
465 | new_node->next = 0; | |
466 | new_node->prev = 0; | |
467 | new_node->height = ++tree->depth; | |
468 | ||
469 | node_desc.next = cpu_to_be32(new_node->next); | |
470 | node_desc.prev = cpu_to_be32(new_node->prev); | |
471 | node_desc.type = new_node->type; | |
472 | node_desc.height = new_node->height; | |
473 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | |
474 | node_desc.reserved = 0; | |
475 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | |
476 | ||
477 | rec = tree->node_size - 2; | |
478 | hfs_bnode_write_u16(new_node, rec, 14); | |
479 | ||
480 | if (node) { | |
481 | /* insert old root idx into new root */ | |
482 | node->parent = tree->root; | |
483 | if (node->type == HFS_NODE_LEAF || | |
484 | tree->attributes & HFS_TREE_VARIDXKEYS) | |
485 | key_size = hfs_bnode_read_u16(node, 14) + 2; | |
486 | else | |
487 | key_size = tree->max_key_len + 2; | |
488 | hfs_bnode_copy(new_node, 14, node, 14, key_size); | |
489 | ||
490 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { | |
491 | key_size = tree->max_key_len + 2; | |
492 | hfs_bnode_write_u16(new_node, 14, tree->max_key_len); | |
493 | } | |
494 | cnid = cpu_to_be32(node->this); | |
495 | hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); | |
496 | ||
497 | rec -= 2; | |
498 | hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); | |
499 | ||
500 | hfs_bnode_put(node); | |
501 | } | |
502 | hfs_bnode_put(new_node); | |
503 | mark_inode_dirty(tree->inode); | |
504 | ||
505 | return 0; | |
506 | } |