blob: 2a734cfccc920263faca60a193e6273457df4b52 [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 {
Anton Salikhmetov2753cc22010-12-16 18:08:38 +020042 recoff = hfs_bnode_read_u16(node,
43 node->tree->node_size - (rec + 1) * 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 if (!recoff)
45 return 0;
Naohiro Aotaaac4e412011-07-12 02:54:13 +090046 if (recoff > node->tree->node_size - 2) {
47 printk(KERN_ERR "hfs: recoff %d too large\n", recoff);
48 return 0;
49 }
Christoph Hellwig13571a62010-10-14 09:54:23 -040050
51 retval = hfs_bnode_read_u16(node, recoff) + 2;
52 if (retval > node->tree->max_key_len + 2) {
53 printk(KERN_ERR "hfs: keylen %d too large\n",
54 retval);
55 retval = 0;
Eric Sandeen9250f922010-10-14 09:53:48 -040056 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 }
58 return retval;
59}
60
61int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
62{
63 struct hfs_btree *tree;
64 struct hfs_bnode *node, *new_node;
65 int size, key_len, rec;
66 int data_off, end_off;
67 int idx_rec_off, data_rec_off, end_rec_off;
68 __be32 cnid;
69
70 tree = fd->tree;
71 if (!fd->bnode) {
72 if (!tree->root)
73 hfs_btree_inc_height(tree);
74 fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
75 if (IS_ERR(fd->bnode))
76 return PTR_ERR(fd->bnode);
77 fd->record = -1;
78 }
79 new_node = NULL;
80 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
81again:
82 /* new record idx and complete record size */
83 rec = fd->record + 1;
84 size = key_len + entry_len;
85
86 node = fd->bnode;
87 hfs_bnode_dump(node);
88 /* get last offset */
89 end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
90 end_off = hfs_bnode_read_u16(node, end_rec_off);
91 end_rec_off -= 2;
Anton Salikhmetov2753cc22010-12-16 18:08:38 +020092 dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
93 rec, size, end_off, end_rec_off);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 if (size > end_rec_off - end_off) {
95 if (new_node)
96 panic("not enough room!\n");
97 new_node = hfs_bnode_split(fd);
98 if (IS_ERR(new_node))
99 return PTR_ERR(new_node);
100 goto again;
101 }
102 if (node->type == HFS_NODE_LEAF) {
103 tree->leaf_count++;
104 mark_inode_dirty(tree->inode);
105 }
106 node->num_recs++;
107 /* write new last offset */
Anton Salikhmetov2753cc22010-12-16 18:08:38 +0200108 hfs_bnode_write_u16(node,
109 offsetof(struct hfs_bnode_desc, num_recs),
110 node->num_recs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 hfs_bnode_write_u16(node, end_rec_off, end_off + size);
112 data_off = end_off;
113 data_rec_off = end_rec_off + 2;
114 idx_rec_off = tree->node_size - (rec + 1) * 2;
115 if (idx_rec_off == data_rec_off)
116 goto skip;
117 /* move all following entries */
118 do {
119 data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
120 hfs_bnode_write_u16(node, data_rec_off, data_off + size);
121 data_rec_off += 2;
122 } while (data_rec_off < idx_rec_off);
123
124 /* move data away */
125 hfs_bnode_move(node, data_off + size, data_off,
126 end_off - data_off);
127
128skip:
129 hfs_bnode_write(node, fd->search_key, data_off, key_len);
130 hfs_bnode_write(node, entry, data_off + key_len, entry_len);
131 hfs_bnode_dump(node);
132
133 if (new_node) {
134 /* update parent key if we inserted a key
135 * at the start of the first node
136 */
137 if (!rec && new_node != node)
138 hfs_brec_update_parent(fd);
139
140 hfs_bnode_put(fd->bnode);
141 if (!new_node->parent) {
142 hfs_btree_inc_height(tree);
143 new_node->parent = tree->root;
144 }
145 fd->bnode = hfs_bnode_find(tree, new_node->parent);
146
147 /* create index data entry */
148 cnid = cpu_to_be32(new_node->this);
149 entry = &cnid;
150 entry_len = sizeof(cnid);
151
152 /* get index key */
153 hfs_bnode_read_key(new_node, fd->search_key, 14);
154 __hfs_brec_find(fd->bnode, fd);
155
156 hfs_bnode_put(new_node);
157 new_node = NULL;
158
159 if (tree->attributes & HFS_TREE_VARIDXKEYS)
160 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
161 else {
Anton Salikhmetov2753cc22010-12-16 18:08:38 +0200162 fd->search_key->key_len =
163 cpu_to_be16(tree->max_key_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 key_len = tree->max_key_len + 2;
165 }
166 goto again;
167 }
168
169 if (!rec)
170 hfs_brec_update_parent(fd);
171
172 return 0;
173}
174
175int hfs_brec_remove(struct hfs_find_data *fd)
176{
177 struct hfs_btree *tree;
178 struct hfs_bnode *node, *parent;
179 int end_off, rec_off, data_off, size;
180
181 tree = fd->tree;
182 node = fd->bnode;
183again:
184 rec_off = tree->node_size - (fd->record + 2) * 2;
185 end_off = tree->node_size - (node->num_recs + 1) * 2;
186
187 if (node->type == HFS_NODE_LEAF) {
188 tree->leaf_count--;
189 mark_inode_dirty(tree->inode);
190 }
191 hfs_bnode_dump(node);
Anton Salikhmetov2753cc22010-12-16 18:08:38 +0200192 dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n",
193 fd->record, fd->keylength + fd->entrylength);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 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 }
Anton Salikhmetov2753cc22010-12-16 18:08:38 +0200207 hfs_bnode_write_u16(node,
208 offsetof(struct hfs_bnode_desc, num_recs),
209 node->num_recs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
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);
224skip:
225 hfs_bnode_dump(node);
226 if (!fd->record)
227 hfs_brec_update_parent(fd);
228 return 0;
229}
230
231static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
232{
233 struct hfs_btree *tree;
Al Virob6b41422010-10-14 09:53:42 -0400234 struct hfs_bnode *node, *new_node, *next_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 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(new_node))
243 return new_node;
244 hfs_bnode_get(node);
245 dprint(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
Al Virob6b41422010-10-14 09:53:42 -0400253 if (node->next)
254 next_node = hfs_bnode_find(tree, node->next);
255 else
256 next_node = NULL;
257
258 if (IS_ERR(next_node)) {
259 hfs_bnode_put(node);
260 hfs_bnode_put(new_node);
261 return next_node;
262 }
263
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 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);
Al Virob6b41422010-10-14 09:53:42 -0400277 if (next_node)
278 hfs_bnode_put(next_node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 return ERR_PTR(-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 */
Al Virob6b41422010-10-14 09:53:42 -0400333 if (next_node) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 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(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
352static 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
366again:
367 parent = hfs_bnode_find(tree, node->parent);
368 if (IS_ERR(parent))
369 return PTR_ERR(parent);
370 __hfs_brec_find(parent, fd);
371 hfs_bnode_dump(parent);
372 rec = fd->record;
373
374 /* size difference between old and new key */
375 if (tree->attributes & HFS_TREE_VARIDXKEYS)
376 newkeylen = hfs_bnode_read_u16(node, 14) + 2;
377 else
378 fd->keylength = newkeylen = tree->max_key_len + 2;
Anton Salikhmetov2753cc22010-12-16 18:08:38 +0200379 dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n",
380 rec, fd->keylength, newkeylen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381
382 rec_off = tree->node_size - (rec + 2) * 2;
383 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
384 diff = newkeylen - fd->keylength;
385 if (!diff)
386 goto skip;
387 if (diff > 0) {
388 end_off = hfs_bnode_read_u16(parent, end_rec_off);
389 if (end_rec_off - end_off < diff) {
390
Christoph Hellwig6d1bbfc2010-11-23 14:37:40 +0100391 dprint(DBG_BNODE_MOD, "hfs: splitting index node.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 fd->bnode = parent;
393 new_node = hfs_bnode_split(fd);
394 if (IS_ERR(new_node))
395 return PTR_ERR(new_node);
396 parent = fd->bnode;
397 rec = fd->record;
398 rec_off = tree->node_size - (rec + 2) * 2;
Anton Salikhmetov2753cc22010-12-16 18:08:38 +0200399 end_rec_off = tree->node_size -
400 (parent->num_recs + 1) * 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 }
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);
415skip:
416 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
417 hfs_bnode_dump(parent);
418
419 hfs_bnode_put(node);
420 node = parent;
421
422 if (new_node) {
423 __be32 cnid;
424
425 fd->bnode = hfs_bnode_find(tree, new_node->parent);
426 /* create index key and entry */
427 hfs_bnode_read_key(new_node, fd->search_key, 14);
428 cnid = cpu_to_be32(new_node->this);
429
430 __hfs_brec_find(fd->bnode, fd);
431 hfs_brec_insert(fd, &cnid, sizeof(cnid));
432 hfs_bnode_put(fd->bnode);
433 hfs_bnode_put(new_node);
434
435 if (!rec) {
436 if (new_node == node)
437 goto out;
438 /* restore search_key */
439 hfs_bnode_read_key(node, fd->search_key, 14);
440 }
441 }
442
443 if (!rec && node->parent)
444 goto again;
445out:
446 fd->bnode = node;
447 return 0;
448}
449
450static int hfs_btree_inc_height(struct hfs_btree *tree)
451{
452 struct hfs_bnode *node, *new_node;
453 struct hfs_bnode_desc node_desc;
454 int key_size, rec;
455 __be32 cnid;
456
457 node = NULL;
458 if (tree->root) {
459 node = hfs_bnode_find(tree, tree->root);
460 if (IS_ERR(node))
461 return PTR_ERR(node);
462 }
463 new_node = hfs_bmap_alloc(tree);
464 if (IS_ERR(new_node)) {
465 hfs_bnode_put(node);
466 return PTR_ERR(new_node);
467 }
468
469 tree->root = new_node->this;
470 if (!tree->depth) {
471 tree->leaf_head = tree->leaf_tail = new_node->this;
472 new_node->type = HFS_NODE_LEAF;
473 new_node->num_recs = 0;
474 } else {
475 new_node->type = HFS_NODE_INDEX;
476 new_node->num_recs = 1;
477 }
478 new_node->parent = 0;
479 new_node->next = 0;
480 new_node->prev = 0;
481 new_node->height = ++tree->depth;
482
483 node_desc.next = cpu_to_be32(new_node->next);
484 node_desc.prev = cpu_to_be32(new_node->prev);
485 node_desc.type = new_node->type;
486 node_desc.height = new_node->height;
487 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
488 node_desc.reserved = 0;
489 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
490
491 rec = tree->node_size - 2;
492 hfs_bnode_write_u16(new_node, rec, 14);
493
494 if (node) {
495 /* insert old root idx into new root */
496 node->parent = tree->root;
497 if (node->type == HFS_NODE_LEAF ||
498 tree->attributes & HFS_TREE_VARIDXKEYS)
499 key_size = hfs_bnode_read_u16(node, 14) + 2;
500 else
501 key_size = tree->max_key_len + 2;
502 hfs_bnode_copy(new_node, 14, node, 14, key_size);
503
504 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
505 key_size = tree->max_key_len + 2;
506 hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
507 }
508 cnid = cpu_to_be32(node->this);
509 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
510
511 rec -= 2;
512 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
513
514 hfs_bnode_put(node);
515 }
516 hfs_bnode_put(new_node);
517 mark_inode_dirty(tree->inode);
518
519 return 0;
520}