2 * linux/fs/hfsplus/brec.c
5 * Brad Boyer (flar@allandria.com)
6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 * Handle individual btree records
11 #include "hfsplus_fs.h"
12 #include "hfsplus_raw.h"
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 *);
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)
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;
30 /* Get the length of the key from a keyed record */
31 u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
35 if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
38 if ((node->type == HFS_NODE_INDEX) &&
39 !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
40 retval = node->tree->max_key_len + 2;
42 recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
45 if (node->tree->attributes & HFS_TREE_BIGKEYS) {
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",
53 retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
54 if (retval > node->tree->max_key_len + 1) {
55 printk(KERN_ERR "hfs: keylen %d too large\n",
64 int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
66 struct hfs_btree *tree;
67 struct hfs_bnode *node, *new_node;
68 int size, key_len, rec;
69 int data_off, end_off;
70 int idx_rec_off, data_rec_off, end_rec_off;
76 hfs_btree_inc_height(tree);
77 fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
78 if (IS_ERR(fd->bnode))
79 return PTR_ERR(fd->bnode);
83 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
85 /* new record idx and complete record size */
87 size = key_len + entry_len;
92 end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
93 end_off = hfs_bnode_read_u16(node, end_rec_off);
95 dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off);
96 if (size > end_rec_off - end_off) {
98 panic("not enough room!\n");
99 new_node = hfs_bnode_split(fd);
100 if (IS_ERR(new_node))
101 return PTR_ERR(new_node);
104 if (node->type == HFS_NODE_LEAF) {
106 mark_inode_dirty(tree->inode);
109 /* write new last offset */
110 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
111 hfs_bnode_write_u16(node, end_rec_off, end_off + size);
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)
117 /* move all following entries */
119 data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
120 hfs_bnode_write_u16(node, data_rec_off, data_off + size);
122 } while (data_rec_off < idx_rec_off);
125 hfs_bnode_move(node, data_off + size, data_off,
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);
134 /* update parent key if we inserted a key
135 * at the start of the first node
137 if (!rec && new_node != node)
138 hfs_brec_update_parent(fd);
140 hfs_bnode_put(fd->bnode);
141 if (!new_node->parent) {
142 hfs_btree_inc_height(tree);
143 new_node->parent = tree->root;
145 fd->bnode = hfs_bnode_find(tree, new_node->parent);
147 /* create index data entry */
148 cnid = cpu_to_be32(new_node->this);
150 entry_len = sizeof(cnid);
153 hfs_bnode_read_key(new_node, fd->search_key, 14);
154 __hfs_brec_find(fd->bnode, fd);
156 hfs_bnode_put(new_node);
159 if (tree->attributes & HFS_TREE_VARIDXKEYS)
160 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
162 fd->search_key->key_len = cpu_to_be16(tree->max_key_len);
163 key_len = tree->max_key_len + 2;
169 hfs_brec_update_parent(fd);
174 int hfs_brec_remove(struct hfs_find_data *fd)
176 struct hfs_btree *tree;
177 struct hfs_bnode *node, *parent;
178 int end_off, rec_off, data_off, size;
183 rec_off = tree->node_size - (fd->record + 2) * 2;
184 end_off = tree->node_size - (node->num_recs + 1) * 2;
186 if (node->type == HFS_NODE_LEAF) {
188 mark_inode_dirty(tree->inode);
190 hfs_bnode_dump(node);
191 dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength);
192 if (!--node->num_recs) {
193 hfs_bnode_unlink(node);
196 parent = hfs_bnode_find(tree, node->parent);
198 return PTR_ERR(parent);
200 node = fd->bnode = parent;
202 __hfs_brec_find(node, fd);
205 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
207 if (rec_off == end_off)
209 size = fd->keylength + fd->entrylength;
212 data_off = hfs_bnode_read_u16(node, rec_off);
213 hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
215 } while (rec_off >= end_off);
218 hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
219 data_off - fd->keyoffset - size);
221 hfs_bnode_dump(node);
223 hfs_brec_update_parent(fd);
227 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
229 struct hfs_btree *tree;
230 struct hfs_bnode *node, *new_node, *next_node;
231 struct hfs_bnode_desc node_desc;
232 int num_recs, new_rec_off, new_off, old_rec_off;
233 int data_start, data_end, size;
237 new_node = hfs_bmap_alloc(tree);
238 if (IS_ERR(new_node))
241 dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n",
242 node->this, new_node->this, node->next);
243 new_node->next = node->next;
244 new_node->prev = node->this;
245 new_node->parent = node->parent;
246 new_node->type = node->type;
247 new_node->height = node->height;
250 next_node = hfs_bnode_find(tree, node->next);
254 if (IS_ERR(next_node)) {
256 hfs_bnode_put(new_node);
260 size = tree->node_size / 2 - node->num_recs * 2 - 14;
261 old_rec_off = tree->node_size - 4;
264 data_start = hfs_bnode_read_u16(node, old_rec_off);
265 if (data_start > size)
268 if (++num_recs < node->num_recs)
272 hfs_bnode_put(new_node);
274 hfs_bnode_put(next_node);
275 return ERR_PTR(-ENOSPC);
278 if (fd->record + 1 < num_recs) {
279 /* new record is in the lower half,
280 * so leave some more space there
284 data_start = hfs_bnode_read_u16(node, old_rec_off);
287 hfs_bnode_get(new_node);
288 fd->bnode = new_node;
289 fd->record -= num_recs;
290 fd->keyoffset -= data_start - 14;
291 fd->entryoffset -= data_start - 14;
293 new_node->num_recs = node->num_recs - num_recs;
294 node->num_recs = num_recs;
296 new_rec_off = tree->node_size - 2;
298 size = data_start - new_off;
299 num_recs = new_node->num_recs;
300 data_end = data_start;
302 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
305 data_end = hfs_bnode_read_u16(node, old_rec_off);
306 new_off = data_end - size;
309 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
310 hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
312 /* update new bnode header */
313 node_desc.next = cpu_to_be32(new_node->next);
314 node_desc.prev = cpu_to_be32(new_node->prev);
315 node_desc.type = new_node->type;
316 node_desc.height = new_node->height;
317 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
318 node_desc.reserved = 0;
319 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
321 /* update previous bnode header */
322 node->next = new_node->this;
323 hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
324 node_desc.next = cpu_to_be32(node->next);
325 node_desc.num_recs = cpu_to_be16(node->num_recs);
326 hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
328 /* update next bnode header */
330 next_node->prev = new_node->this;
331 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
332 node_desc.prev = cpu_to_be32(next_node->prev);
333 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
334 hfs_bnode_put(next_node);
335 } else if (node->this == tree->leaf_tail) {
336 /* if there is no next node, this might be the new tail */
337 tree->leaf_tail = new_node->this;
338 mark_inode_dirty(tree->inode);
341 hfs_bnode_dump(node);
342 hfs_bnode_dump(new_node);
348 static int hfs_brec_update_parent(struct hfs_find_data *fd)
350 struct hfs_btree *tree;
351 struct hfs_bnode *node, *new_node, *parent;
353 int rec, rec_off, end_rec_off;
354 int start_off, end_off;
363 parent = hfs_bnode_find(tree, node->parent);
365 return PTR_ERR(parent);
366 __hfs_brec_find(parent, fd);
367 hfs_bnode_dump(parent);
370 /* size difference between old and new key */
371 if (tree->attributes & HFS_TREE_VARIDXKEYS)
372 newkeylen = hfs_bnode_read_u16(node, 14) + 2;
374 fd->keylength = newkeylen = tree->max_key_len + 2;
375 dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen);
377 rec_off = tree->node_size - (rec + 2) * 2;
378 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
379 diff = newkeylen - fd->keylength;
383 end_off = hfs_bnode_read_u16(parent, end_rec_off);
384 if (end_rec_off - end_off < diff) {
386 printk(KERN_DEBUG "hfs: splitting index node...\n");
388 new_node = hfs_bnode_split(fd);
389 if (IS_ERR(new_node))
390 return PTR_ERR(new_node);
393 rec_off = tree->node_size - (rec + 2) * 2;
394 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
398 end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
399 hfs_bnode_write_u16(parent, rec_off, start_off + diff);
400 start_off -= 4; /* move previous cnid too */
402 while (rec_off > end_rec_off) {
404 end_off = hfs_bnode_read_u16(parent, rec_off);
405 hfs_bnode_write_u16(parent, rec_off, end_off + diff);
407 hfs_bnode_move(parent, start_off + diff, start_off,
408 end_off - start_off);
410 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
411 hfs_bnode_dump(parent);
419 fd->bnode = hfs_bnode_find(tree, new_node->parent);
420 /* create index key and entry */
421 hfs_bnode_read_key(new_node, fd->search_key, 14);
422 cnid = cpu_to_be32(new_node->this);
424 __hfs_brec_find(fd->bnode, fd);
425 hfs_brec_insert(fd, &cnid, sizeof(cnid));
426 hfs_bnode_put(fd->bnode);
427 hfs_bnode_put(new_node);
430 if (new_node == node)
432 /* restore search_key */
433 hfs_bnode_read_key(node, fd->search_key, 14);
437 if (!rec && node->parent)
444 static int hfs_btree_inc_height(struct hfs_btree *tree)
446 struct hfs_bnode *node, *new_node;
447 struct hfs_bnode_desc node_desc;
453 node = hfs_bnode_find(tree, tree->root);
455 return PTR_ERR(node);
457 new_node = hfs_bmap_alloc(tree);
458 if (IS_ERR(new_node)) {
460 return PTR_ERR(new_node);
463 tree->root = new_node->this;
465 tree->leaf_head = tree->leaf_tail = new_node->this;
466 new_node->type = HFS_NODE_LEAF;
467 new_node->num_recs = 0;
469 new_node->type = HFS_NODE_INDEX;
470 new_node->num_recs = 1;
472 new_node->parent = 0;
475 new_node->height = ++tree->depth;
477 node_desc.next = cpu_to_be32(new_node->next);
478 node_desc.prev = cpu_to_be32(new_node->prev);
479 node_desc.type = new_node->type;
480 node_desc.height = new_node->height;
481 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
482 node_desc.reserved = 0;
483 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
485 rec = tree->node_size - 2;
486 hfs_bnode_write_u16(new_node, rec, 14);
489 /* insert old root idx into new root */
490 node->parent = tree->root;
491 if (node->type == HFS_NODE_LEAF ||
492 tree->attributes & HFS_TREE_VARIDXKEYS)
493 key_size = hfs_bnode_read_u16(node, 14) + 2;
495 key_size = tree->max_key_len + 2;
496 hfs_bnode_copy(new_node, 14, node, 14, key_size);
498 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
499 key_size = tree->max_key_len + 2;
500 hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
502 cnid = cpu_to_be32(node->this);
503 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
506 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
510 hfs_bnode_put(new_node);
511 mark_inode_dirty(tree->inode);