blob: 0ccef2ab790c048b6b838ed3d4753d09e62fa164 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
14static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
15static int hfs_brec_update_parent(struct hfs_find_data *fd);
16static int hfs_btree_inc_height(struct hfs_btree *);
17
18/* Get the length and offset of the given record in the given node */
19u16 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 */
31u16 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;
45 if (node->tree->attributes & HFS_TREE_BIGKEYS)
46 retval = hfs_bnode_read_u16(node, recoff) + 2;
47 else
48 retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
49 }
50 return retval;
51}
52
53int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
54{
55 struct hfs_btree *tree;
56 struct hfs_bnode *node, *new_node;
57 int size, key_len, rec;
58 int data_off, end_off;
59 int idx_rec_off, data_rec_off, end_rec_off;
60 __be32 cnid;
61
62 tree = fd->tree;
63 if (!fd->bnode) {
64 if (!tree->root)
65 hfs_btree_inc_height(tree);
66 fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
67 if (IS_ERR(fd->bnode))
68 return PTR_ERR(fd->bnode);
69 fd->record = -1;
70 }
71 new_node = NULL;
72 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
73again:
74 /* new record idx and complete record size */
75 rec = fd->record + 1;
76 size = key_len + entry_len;
77
78 node = fd->bnode;
79 hfs_bnode_dump(node);
80 /* get last offset */
81 end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
82 end_off = hfs_bnode_read_u16(node, end_rec_off);
83 end_rec_off -= 2;
84 dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off);
85 if (size > end_rec_off - end_off) {
86 if (new_node)
87 panic("not enough room!\n");
88 new_node = hfs_bnode_split(fd);
89 if (IS_ERR(new_node))
90 return PTR_ERR(new_node);
91 goto again;
92 }
93 if (node->type == HFS_NODE_LEAF) {
94 tree->leaf_count++;
95 mark_inode_dirty(tree->inode);
96 }
97 node->num_recs++;
98 /* write new last offset */
99 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
100 hfs_bnode_write_u16(node, end_rec_off, end_off + size);
101 data_off = end_off;
102 data_rec_off = end_rec_off + 2;
103 idx_rec_off = tree->node_size - (rec + 1) * 2;
104 if (idx_rec_off == data_rec_off)
105 goto skip;
106 /* move all following entries */
107 do {
108 data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
109 hfs_bnode_write_u16(node, data_rec_off, data_off + size);
110 data_rec_off += 2;
111 } while (data_rec_off < idx_rec_off);
112
113 /* move data away */
114 hfs_bnode_move(node, data_off + size, data_off,
115 end_off - data_off);
116
117skip:
118 hfs_bnode_write(node, fd->search_key, data_off, key_len);
119 hfs_bnode_write(node, entry, data_off + key_len, entry_len);
120 hfs_bnode_dump(node);
121
122 if (new_node) {
123 /* update parent key if we inserted a key
124 * at the start of the first node
125 */
126 if (!rec && new_node != node)
127 hfs_brec_update_parent(fd);
128
129 hfs_bnode_put(fd->bnode);
130 if (!new_node->parent) {
131 hfs_btree_inc_height(tree);
132 new_node->parent = tree->root;
133 }
134 fd->bnode = hfs_bnode_find(tree, new_node->parent);
135
136 /* create index data entry */
137 cnid = cpu_to_be32(new_node->this);
138 entry = &cnid;
139 entry_len = sizeof(cnid);
140
141 /* get index key */
142 hfs_bnode_read_key(new_node, fd->search_key, 14);
143 __hfs_brec_find(fd->bnode, fd);
144
145 hfs_bnode_put(new_node);
146 new_node = NULL;
147
148 if (tree->attributes & HFS_TREE_VARIDXKEYS)
149 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
150 else {
151 fd->search_key->key_len = cpu_to_be16(tree->max_key_len);
152 key_len = tree->max_key_len + 2;
153 }
154 goto again;
155 }
156
157 if (!rec)
158 hfs_brec_update_parent(fd);
159
160 return 0;
161}
162
163int hfs_brec_remove(struct hfs_find_data *fd)
164{
165 struct hfs_btree *tree;
166 struct hfs_bnode *node, *parent;
167 int end_off, rec_off, data_off, size;
168
169 tree = fd->tree;
170 node = fd->bnode;
171again:
172 rec_off = tree->node_size - (fd->record + 2) * 2;
173 end_off = tree->node_size - (node->num_recs + 1) * 2;
174
175 if (node->type == HFS_NODE_LEAF) {
176 tree->leaf_count--;
177 mark_inode_dirty(tree->inode);
178 }
179 hfs_bnode_dump(node);
180 dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength);
181 if (!--node->num_recs) {
182 hfs_bnode_unlink(node);
183 if (!node->parent)
184 return 0;
185 parent = hfs_bnode_find(tree, node->parent);
186 if (IS_ERR(parent))
187 return PTR_ERR(parent);
188 hfs_bnode_put(node);
189 node = fd->bnode = parent;
190
191 __hfs_brec_find(node, fd);
192 goto again;
193 }
194 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
195
196 if (rec_off == end_off)
197 goto skip;
198 size = fd->keylength + fd->entrylength;
199
200 do {
201 data_off = hfs_bnode_read_u16(node, rec_off);
202 hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
203 rec_off -= 2;
204 } while (rec_off >= end_off);
205
206 /* fill hole */
207 hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
208 data_off - fd->keyoffset - size);
209skip:
210 hfs_bnode_dump(node);
211 if (!fd->record)
212 hfs_brec_update_parent(fd);
213 return 0;
214}
215
216static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
217{
218 struct hfs_btree *tree;
219 struct hfs_bnode *node, *new_node;
220 struct hfs_bnode_desc node_desc;
221 int num_recs, new_rec_off, new_off, old_rec_off;
222 int data_start, data_end, size;
223
224 tree = fd->tree;
225 node = fd->bnode;
226 new_node = hfs_bmap_alloc(tree);
227 if (IS_ERR(new_node))
228 return new_node;
229 hfs_bnode_get(node);
230 dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n",
231 node->this, new_node->this, node->next);
232 new_node->next = node->next;
233 new_node->prev = node->this;
234 new_node->parent = node->parent;
235 new_node->type = node->type;
236 new_node->height = node->height;
237
238 size = tree->node_size / 2 - node->num_recs * 2 - 14;
239 old_rec_off = tree->node_size - 4;
240 num_recs = 1;
241 for (;;) {
242 data_start = hfs_bnode_read_u16(node, old_rec_off);
243 if (data_start > size)
244 break;
245 old_rec_off -= 2;
246 if (++num_recs < node->num_recs)
247 continue;
248 /* panic? */
249 hfs_bnode_put(node);
250 hfs_bnode_put(new_node);
251 return ERR_PTR(-ENOSPC);
252 }
253
254 if (fd->record + 1 < num_recs) {
255 /* new record is in the lower half,
256 * so leave some more space there
257 */
258 old_rec_off += 2;
259 num_recs--;
260 data_start = hfs_bnode_read_u16(node, old_rec_off);
261 } else {
262 hfs_bnode_put(node);
263 hfs_bnode_get(new_node);
264 fd->bnode = new_node;
265 fd->record -= num_recs;
266 fd->keyoffset -= data_start - 14;
267 fd->entryoffset -= data_start - 14;
268 }
269 new_node->num_recs = node->num_recs - num_recs;
270 node->num_recs = num_recs;
271
272 new_rec_off = tree->node_size - 2;
273 new_off = 14;
274 size = data_start - new_off;
275 num_recs = new_node->num_recs;
276 data_end = data_start;
277 while (num_recs) {
278 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
279 old_rec_off -= 2;
280 new_rec_off -= 2;
281 data_end = hfs_bnode_read_u16(node, old_rec_off);
282 new_off = data_end - size;
283 num_recs--;
284 }
285 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
286 hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
287
288 /* update new bnode header */
289 node_desc.next = cpu_to_be32(new_node->next);
290 node_desc.prev = cpu_to_be32(new_node->prev);
291 node_desc.type = new_node->type;
292 node_desc.height = new_node->height;
293 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
294 node_desc.reserved = 0;
295 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
296
297 /* update previous bnode header */
298 node->next = new_node->this;
299 hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
300 node_desc.next = cpu_to_be32(node->next);
301 node_desc.num_recs = cpu_to_be16(node->num_recs);
302 hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
303
304 /* update next bnode header */
305 if (new_node->next) {
306 struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next);
307 next_node->prev = new_node->this;
308 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
309 node_desc.prev = cpu_to_be32(next_node->prev);
310 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
311 hfs_bnode_put(next_node);
312 } else if (node->this == tree->leaf_tail) {
313 /* if there is no next node, this might be the new tail */
314 tree->leaf_tail = new_node->this;
315 mark_inode_dirty(tree->inode);
316 }
317
318 hfs_bnode_dump(node);
319 hfs_bnode_dump(new_node);
320 hfs_bnode_put(node);
321
322 return new_node;
323}
324
325static int hfs_brec_update_parent(struct hfs_find_data *fd)
326{
327 struct hfs_btree *tree;
328 struct hfs_bnode *node, *new_node, *parent;
329 int newkeylen, diff;
330 int rec, rec_off, end_rec_off;
331 int start_off, end_off;
332
333 tree = fd->tree;
334 node = fd->bnode;
335 new_node = NULL;
336 if (!node->parent)
337 return 0;
338
339again:
340 parent = hfs_bnode_find(tree, node->parent);
341 if (IS_ERR(parent))
342 return PTR_ERR(parent);
343 __hfs_brec_find(parent, fd);
344 hfs_bnode_dump(parent);
345 rec = fd->record;
346
347 /* size difference between old and new key */
348 if (tree->attributes & HFS_TREE_VARIDXKEYS)
349 newkeylen = hfs_bnode_read_u16(node, 14) + 2;
350 else
351 fd->keylength = newkeylen = tree->max_key_len + 2;
352 dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen);
353
354 rec_off = tree->node_size - (rec + 2) * 2;
355 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
356 diff = newkeylen - fd->keylength;
357 if (!diff)
358 goto skip;
359 if (diff > 0) {
360 end_off = hfs_bnode_read_u16(parent, end_rec_off);
361 if (end_rec_off - end_off < diff) {
362
363 printk("splitting index node...\n");
364 fd->bnode = parent;
365 new_node = hfs_bnode_split(fd);
366 if (IS_ERR(new_node))
367 return PTR_ERR(new_node);
368 parent = fd->bnode;
369 rec = fd->record;
370 rec_off = tree->node_size - (rec + 2) * 2;
371 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
372 }
373 }
374
375 end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
376 hfs_bnode_write_u16(parent, rec_off, start_off + diff);
377 start_off -= 4; /* move previous cnid too */
378
379 while (rec_off > end_rec_off) {
380 rec_off -= 2;
381 end_off = hfs_bnode_read_u16(parent, rec_off);
382 hfs_bnode_write_u16(parent, rec_off, end_off + diff);
383 }
384 hfs_bnode_move(parent, start_off + diff, start_off,
385 end_off - start_off);
386skip:
387 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
388 hfs_bnode_dump(parent);
389
390 hfs_bnode_put(node);
391 node = parent;
392
393 if (new_node) {
394 __be32 cnid;
395
396 fd->bnode = hfs_bnode_find(tree, new_node->parent);
397 /* create index key and entry */
398 hfs_bnode_read_key(new_node, fd->search_key, 14);
399 cnid = cpu_to_be32(new_node->this);
400
401 __hfs_brec_find(fd->bnode, fd);
402 hfs_brec_insert(fd, &cnid, sizeof(cnid));
403 hfs_bnode_put(fd->bnode);
404 hfs_bnode_put(new_node);
405
406 if (!rec) {
407 if (new_node == node)
408 goto out;
409 /* restore search_key */
410 hfs_bnode_read_key(node, fd->search_key, 14);
411 }
412 }
413
414 if (!rec && node->parent)
415 goto again;
416out:
417 fd->bnode = node;
418 return 0;
419}
420
421static int hfs_btree_inc_height(struct hfs_btree *tree)
422{
423 struct hfs_bnode *node, *new_node;
424 struct hfs_bnode_desc node_desc;
425 int key_size, rec;
426 __be32 cnid;
427
428 node = NULL;
429 if (tree->root) {
430 node = hfs_bnode_find(tree, tree->root);
431 if (IS_ERR(node))
432 return PTR_ERR(node);
433 }
434 new_node = hfs_bmap_alloc(tree);
435 if (IS_ERR(new_node)) {
436 hfs_bnode_put(node);
437 return PTR_ERR(new_node);
438 }
439
440 tree->root = new_node->this;
441 if (!tree->depth) {
442 tree->leaf_head = tree->leaf_tail = new_node->this;
443 new_node->type = HFS_NODE_LEAF;
444 new_node->num_recs = 0;
445 } else {
446 new_node->type = HFS_NODE_INDEX;
447 new_node->num_recs = 1;
448 }
449 new_node->parent = 0;
450 new_node->next = 0;
451 new_node->prev = 0;
452 new_node->height = ++tree->depth;
453
454 node_desc.next = cpu_to_be32(new_node->next);
455 node_desc.prev = cpu_to_be32(new_node->prev);
456 node_desc.type = new_node->type;
457 node_desc.height = new_node->height;
458 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
459 node_desc.reserved = 0;
460 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
461
462 rec = tree->node_size - 2;
463 hfs_bnode_write_u16(new_node, rec, 14);
464
465 if (node) {
466 /* insert old root idx into new root */
467 node->parent = tree->root;
468 if (node->type == HFS_NODE_LEAF ||
469 tree->attributes & HFS_TREE_VARIDXKEYS)
470 key_size = hfs_bnode_read_u16(node, 14) + 2;
471 else
472 key_size = tree->max_key_len + 2;
473 hfs_bnode_copy(new_node, 14, node, 14, key_size);
474
475 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
476 key_size = tree->max_key_len + 2;
477 hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
478 }
479 cnid = cpu_to_be32(node->this);
480 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
481
482 rec -= 2;
483 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
484
485 hfs_bnode_put(node);
486 }
487 hfs_bnode_put(new_node);
488 mark_inode_dirty(tree->inode);
489
490 return 0;
491}