blob: 92fb358ce824325e6b8275388b111e70728463dc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
13static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
14static int hfs_brec_update_parent(struct hfs_find_data *fd);
15static int hfs_btree_inc_height(struct hfs_btree *tree);
16
17/* Get the length and offset of the given record in the given node */
18u16 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 */
30u16 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;
Eric Sandeencf059462008-01-08 15:33:20 -080047 if (node->tree->attributes & HFS_TREE_BIGKEYS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 retval = hfs_bnode_read_u16(node, recoff) + 2;
Eric Sandeencf059462008-01-08 15:33:20 -080049 if (retval > node->tree->max_key_len + 2) {
50 printk(KERN_ERR "hfs: keylen %d too large\n",
51 retval);
Eric Sandeen55581d02008-02-06 01:37:10 -080052 retval = 0;
Eric Sandeencf059462008-01-08 15:33:20 -080053 }
54 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
Eric Sandeencf059462008-01-08 15:33:20 -080056 if (retval > node->tree->max_key_len + 1) {
57 printk(KERN_ERR "hfs: keylen %d too large\n",
58 retval);
Eric Sandeen55581d02008-02-06 01:37:10 -080059 retval = 0;
Eric Sandeencf059462008-01-08 15:33:20 -080060 }
61 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 }
63 return retval;
64}
65
66int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
67{
68 struct hfs_btree *tree;
69 struct hfs_bnode *node, *new_node;
70 int size, key_len, rec;
71 int data_off, end_off;
72 int idx_rec_off, data_rec_off, end_rec_off;
73 __be32 cnid;
74
75 tree = fd->tree;
76 if (!fd->bnode) {
77 if (!tree->root)
78 hfs_btree_inc_height(tree);
79 fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
80 if (IS_ERR(fd->bnode))
81 return PTR_ERR(fd->bnode);
82 fd->record = -1;
83 }
84 new_node = NULL;
85 key_len = (fd->search_key->key_len | 1) + 1;
86again:
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 dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off);
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
130skip:
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
135 if (new_node) {
136 /* update parent key if we inserted a key
137 * at the start of the first node
138 */
139 if (!rec && new_node != node)
140 hfs_brec_update_parent(fd);
141
142 hfs_bnode_put(fd->bnode);
143 if (!new_node->parent) {
144 hfs_btree_inc_height(tree);
145 new_node->parent = tree->root;
146 }
147 fd->bnode = hfs_bnode_find(tree, new_node->parent);
148
149 /* create index data entry */
150 cnid = cpu_to_be32(new_node->this);
151 entry = &cnid;
152 entry_len = sizeof(cnid);
153
154 /* get index key */
155 hfs_bnode_read_key(new_node, fd->search_key, 14);
156 __hfs_brec_find(fd->bnode, fd);
157
158 hfs_bnode_put(new_node);
159 new_node = NULL;
160
161 if (tree->attributes & HFS_TREE_VARIDXKEYS)
162 key_len = fd->search_key->key_len + 1;
163 else {
164 fd->search_key->key_len = tree->max_key_len;
165 key_len = tree->max_key_len + 1;
166 }
167 goto again;
168 }
169
170 if (!rec)
171 hfs_brec_update_parent(fd);
172
173 return 0;
174}
175
176int 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;
184again:
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);
193 dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength);
194 if (!--node->num_recs) {
195 hfs_bnode_unlink(node);
196 if (!node->parent)
197 return 0;
198 parent = hfs_bnode_find(tree, node->parent);
199 if (IS_ERR(parent))
200 return PTR_ERR(parent);
201 hfs_bnode_put(node);
202 node = fd->bnode = parent;
203
204 __hfs_brec_find(node, fd);
205 goto again;
206 }
207 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
208
209 if (rec_off == end_off)
210 goto skip;
211 size = fd->keylength + fd->entrylength;
212
213 do {
214 data_off = hfs_bnode_read_u16(node, rec_off);
215 hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
216 rec_off -= 2;
217 } while (rec_off >= end_off);
218
219 /* fill hole */
220 hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
221 data_off - fd->keyoffset - size);
222skip:
223 hfs_bnode_dump(node);
224 if (!fd->record)
225 hfs_brec_update_parent(fd);
226 return 0;
227}
228
229static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
230{
231 struct hfs_btree *tree;
Al Viro3d10a152008-03-16 22:48:08 +0000232 struct hfs_bnode *node, *new_node, *next_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 struct hfs_bnode_desc node_desc;
234 int num_recs, new_rec_off, new_off, old_rec_off;
235 int data_start, data_end, size;
236
237 tree = fd->tree;
238 node = fd->bnode;
239 new_node = hfs_bmap_alloc(tree);
240 if (IS_ERR(new_node))
241 return new_node;
242 hfs_bnode_get(node);
243 dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n",
244 node->this, new_node->this, node->next);
245 new_node->next = node->next;
246 new_node->prev = node->this;
247 new_node->parent = node->parent;
248 new_node->type = node->type;
249 new_node->height = node->height;
250
Al Viro3d10a152008-03-16 22:48:08 +0000251 if (node->next)
252 next_node = hfs_bnode_find(tree, node->next);
253 else
254 next_node = NULL;
255
256 if (IS_ERR(next_node)) {
257 hfs_bnode_put(node);
258 hfs_bnode_put(new_node);
259 return next_node;
260 }
261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 size = tree->node_size / 2 - node->num_recs * 2 - 14;
263 old_rec_off = tree->node_size - 4;
264 num_recs = 1;
265 for (;;) {
266 data_start = hfs_bnode_read_u16(node, old_rec_off);
267 if (data_start > size)
268 break;
269 old_rec_off -= 2;
270 if (++num_recs < node->num_recs)
271 continue;
272 /* panic? */
273 hfs_bnode_put(node);
274 hfs_bnode_put(new_node);
Al Viro3d10a152008-03-16 22:48:08 +0000275 if (next_node)
276 hfs_bnode_put(next_node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 return ERR_PTR(-ENOSPC);
278 }
279
280 if (fd->record + 1 < num_recs) {
281 /* new record is in the lower half,
282 * so leave some more space there
283 */
284 old_rec_off += 2;
285 num_recs--;
286 data_start = hfs_bnode_read_u16(node, old_rec_off);
287 } else {
288 hfs_bnode_put(node);
289 hfs_bnode_get(new_node);
290 fd->bnode = new_node;
291 fd->record -= num_recs;
292 fd->keyoffset -= data_start - 14;
293 fd->entryoffset -= data_start - 14;
294 }
295 new_node->num_recs = node->num_recs - num_recs;
296 node->num_recs = num_recs;
297
298 new_rec_off = tree->node_size - 2;
299 new_off = 14;
300 size = data_start - new_off;
301 num_recs = new_node->num_recs;
302 data_end = data_start;
303 while (num_recs) {
304 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
305 old_rec_off -= 2;
306 new_rec_off -= 2;
307 data_end = hfs_bnode_read_u16(node, old_rec_off);
308 new_off = data_end - size;
309 num_recs--;
310 }
311 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
312 hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
313
314 /* update new bnode header */
315 node_desc.next = cpu_to_be32(new_node->next);
316 node_desc.prev = cpu_to_be32(new_node->prev);
317 node_desc.type = new_node->type;
318 node_desc.height = new_node->height;
319 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
320 node_desc.reserved = 0;
321 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
322
323 /* update previous bnode header */
324 node->next = new_node->this;
325 hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
326 node_desc.next = cpu_to_be32(node->next);
327 node_desc.num_recs = cpu_to_be16(node->num_recs);
328 hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
329
330 /* update next bnode header */
Al Viro3d10a152008-03-16 22:48:08 +0000331 if (next_node) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 next_node->prev = new_node->this;
333 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
334 node_desc.prev = cpu_to_be32(next_node->prev);
335 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
336 hfs_bnode_put(next_node);
337 } else if (node->this == tree->leaf_tail) {
338 /* if there is no next node, this might be the new tail */
339 tree->leaf_tail = new_node->this;
340 mark_inode_dirty(tree->inode);
341 }
342
343 hfs_bnode_dump(node);
344 hfs_bnode_dump(new_node);
345 hfs_bnode_put(node);
346
347 return new_node;
348}
349
350static int hfs_brec_update_parent(struct hfs_find_data *fd)
351{
352 struct hfs_btree *tree;
353 struct hfs_bnode *node, *new_node, *parent;
354 int newkeylen, diff;
355 int rec, rec_off, end_rec_off;
356 int start_off, end_off;
357
358 tree = fd->tree;
359 node = fd->bnode;
360 new_node = NULL;
361 if (!node->parent)
362 return 0;
363
364again:
365 parent = hfs_bnode_find(tree, node->parent);
366 if (IS_ERR(parent))
367 return PTR_ERR(parent);
368 __hfs_brec_find(parent, fd);
369 hfs_bnode_dump(parent);
370 rec = fd->record;
371
372 /* size difference between old and new key */
373 if (tree->attributes & HFS_TREE_VARIDXKEYS)
374 newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1;
375 else
376 fd->keylength = newkeylen = tree->max_key_len + 1;
377 dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen);
378
379 rec_off = tree->node_size - (rec + 2) * 2;
380 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
381 diff = newkeylen - fd->keylength;
382 if (!diff)
383 goto skip;
384 if (diff > 0) {
385 end_off = hfs_bnode_read_u16(parent, end_rec_off);
386 if (end_rec_off - end_off < diff) {
387
Roman Zippel7cf3cc32006-01-18 17:43:07 -0800388 printk(KERN_DEBUG "hfs: splitting index node...\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 fd->bnode = parent;
390 new_node = hfs_bnode_split(fd);
391 if (IS_ERR(new_node))
392 return PTR_ERR(new_node);
393 parent = fd->bnode;
394 rec = fd->record;
395 rec_off = tree->node_size - (rec + 2) * 2;
396 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
397 }
398 }
399
400 end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
401 hfs_bnode_write_u16(parent, rec_off, start_off + diff);
402 start_off -= 4; /* move previous cnid too */
403
404 while (rec_off > end_rec_off) {
405 rec_off -= 2;
406 end_off = hfs_bnode_read_u16(parent, rec_off);
407 hfs_bnode_write_u16(parent, rec_off, end_off + diff);
408 }
409 hfs_bnode_move(parent, start_off + diff, start_off,
410 end_off - start_off);
411skip:
412 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
413 if (!(tree->attributes & HFS_TREE_VARIDXKEYS))
414 hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1);
415 hfs_bnode_dump(parent);
416
417 hfs_bnode_put(node);
418 node = parent;
419
420 if (new_node) {
421 __be32 cnid;
422
423 fd->bnode = hfs_bnode_find(tree, new_node->parent);
424 /* create index key and entry */
425 hfs_bnode_read_key(new_node, fd->search_key, 14);
426 cnid = cpu_to_be32(new_node->this);
427
428 __hfs_brec_find(fd->bnode, fd);
429 hfs_brec_insert(fd, &cnid, sizeof(cnid));
430 hfs_bnode_put(fd->bnode);
431 hfs_bnode_put(new_node);
432
433 if (!rec) {
434 if (new_node == node)
435 goto out;
436 /* restore search_key */
437 hfs_bnode_read_key(node, fd->search_key, 14);
438 }
439 }
440
441 if (!rec && node->parent)
442 goto again;
443out:
444 fd->bnode = node;
445 return 0;
446}
447
448static int hfs_btree_inc_height(struct hfs_btree *tree)
449{
450 struct hfs_bnode *node, *new_node;
451 struct hfs_bnode_desc node_desc;
452 int key_size, rec;
453 __be32 cnid;
454
455 node = NULL;
456 if (tree->root) {
457 node = hfs_bnode_find(tree, tree->root);
458 if (IS_ERR(node))
459 return PTR_ERR(node);
460 }
461 new_node = hfs_bmap_alloc(tree);
462 if (IS_ERR(new_node)) {
463 hfs_bnode_put(node);
464 return PTR_ERR(new_node);
465 }
466
467 tree->root = new_node->this;
468 if (!tree->depth) {
469 tree->leaf_head = tree->leaf_tail = new_node->this;
470 new_node->type = HFS_NODE_LEAF;
471 new_node->num_recs = 0;
472 } else {
473 new_node->type = HFS_NODE_INDEX;
474 new_node->num_recs = 1;
475 }
476 new_node->parent = 0;
477 new_node->next = 0;
478 new_node->prev = 0;
479 new_node->height = ++tree->depth;
480
481 node_desc.next = cpu_to_be32(new_node->next);
482 node_desc.prev = cpu_to_be32(new_node->prev);
483 node_desc.type = new_node->type;
484 node_desc.height = new_node->height;
485 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
486 node_desc.reserved = 0;
487 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
488
489 rec = tree->node_size - 2;
490 hfs_bnode_write_u16(new_node, rec, 14);
491
492 if (node) {
493 /* insert old root idx into new root */
494 node->parent = tree->root;
495 if (node->type == HFS_NODE_LEAF ||
496 tree->attributes & HFS_TREE_VARIDXKEYS)
497 key_size = hfs_bnode_read_u8(node, 14) + 1;
498 else
499 key_size = tree->max_key_len + 1;
500 hfs_bnode_copy(new_node, 14, node, 14, key_size);
501
502 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
503 key_size = tree->max_key_len + 1;
504 hfs_bnode_write_u8(new_node, 14, tree->max_key_len);
505 }
506 key_size = (key_size + 1) & -2;
507 cnid = cpu_to_be32(node->this);
508 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
509
510 rec -= 2;
511 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
512
513 hfs_bnode_put(node);
514 }
515 hfs_bnode_put(new_node);
516 mark_inode_dirty(tree->inode);
517
518 return 0;
519}