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;
48 retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
53 int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
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;
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);
72 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
74 /* new record idx and complete record size */
76 size = key_len + entry_len;
81 end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
82 end_off = hfs_bnode_read_u16(node, end_rec_off);
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) {
87 panic("not enough room!\n");
88 new_node = hfs_bnode_split(fd);
90 return PTR_ERR(new_node);
93 if (node->type == HFS_NODE_LEAF) {
95 mark_inode_dirty(tree->inode);
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);
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)
106 /* move all following entries */
108 data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
109 hfs_bnode_write_u16(node, data_rec_off, data_off + size);
111 } while (data_rec_off < idx_rec_off);
114 hfs_bnode_move(node, data_off + size, data_off,
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);
123 /* update parent key if we inserted a key
124 * at the start of the first node
126 if (!rec && new_node != node)
127 hfs_brec_update_parent(fd);
129 hfs_bnode_put(fd->bnode);
130 if (!new_node->parent) {
131 hfs_btree_inc_height(tree);
132 new_node->parent = tree->root;
134 fd->bnode = hfs_bnode_find(tree, new_node->parent);
136 /* create index data entry */
137 cnid = cpu_to_be32(new_node->this);
139 entry_len = sizeof(cnid);
142 hfs_bnode_read_key(new_node, fd->search_key, 14);
143 __hfs_brec_find(fd->bnode, fd);
145 hfs_bnode_put(new_node);
148 if (tree->attributes & HFS_TREE_VARIDXKEYS)
149 key_len = be16_to_cpu(fd->search_key->key_len) + 2;
151 fd->search_key->key_len = cpu_to_be16(tree->max_key_len);
152 key_len = tree->max_key_len + 2;
158 hfs_brec_update_parent(fd);
163 int hfs_brec_remove(struct hfs_find_data *fd)
165 struct hfs_btree *tree;
166 struct hfs_bnode *node, *parent;
167 int end_off, rec_off, data_off, size;
172 rec_off = tree->node_size - (fd->record + 2) * 2;
173 end_off = tree->node_size - (node->num_recs + 1) * 2;
175 if (node->type == HFS_NODE_LEAF) {
177 mark_inode_dirty(tree->inode);
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);
185 parent = hfs_bnode_find(tree, node->parent);
187 return PTR_ERR(parent);
189 node = fd->bnode = parent;
191 __hfs_brec_find(node, fd);
194 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
196 if (rec_off == end_off)
198 size = fd->keylength + fd->entrylength;
201 data_off = hfs_bnode_read_u16(node, rec_off);
202 hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
204 } while (rec_off >= end_off);
207 hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
208 data_off - fd->keyoffset - size);
210 hfs_bnode_dump(node);
212 hfs_brec_update_parent(fd);
216 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
218 struct hfs_btree *tree;
219 struct hfs_bnode *node, *new_node, *next_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;
226 new_node = hfs_bmap_alloc(tree);
227 if (IS_ERR(new_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;
239 next_node = hfs_bnode_find(tree, node->next);
243 if (IS_ERR(next_node)) {
245 hfs_bnode_put(new_node);
249 size = tree->node_size / 2 - node->num_recs * 2 - 14;
250 old_rec_off = tree->node_size - 4;
253 data_start = hfs_bnode_read_u16(node, old_rec_off);
254 if (data_start > size)
257 if (++num_recs < node->num_recs)
261 hfs_bnode_put(new_node);
263 hfs_bnode_put(next_node);
264 return ERR_PTR(-ENOSPC);
267 if (fd->record + 1 < num_recs) {
268 /* new record is in the lower half,
269 * so leave some more space there
273 data_start = hfs_bnode_read_u16(node, old_rec_off);
276 hfs_bnode_get(new_node);
277 fd->bnode = new_node;
278 fd->record -= num_recs;
279 fd->keyoffset -= data_start - 14;
280 fd->entryoffset -= data_start - 14;
282 new_node->num_recs = node->num_recs - num_recs;
283 node->num_recs = num_recs;
285 new_rec_off = tree->node_size - 2;
287 size = data_start - new_off;
288 num_recs = new_node->num_recs;
289 data_end = data_start;
291 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
294 data_end = hfs_bnode_read_u16(node, old_rec_off);
295 new_off = data_end - size;
298 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
299 hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
301 /* update new bnode header */
302 node_desc.next = cpu_to_be32(new_node->next);
303 node_desc.prev = cpu_to_be32(new_node->prev);
304 node_desc.type = new_node->type;
305 node_desc.height = new_node->height;
306 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
307 node_desc.reserved = 0;
308 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
310 /* update previous bnode header */
311 node->next = new_node->this;
312 hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
313 node_desc.next = cpu_to_be32(node->next);
314 node_desc.num_recs = cpu_to_be16(node->num_recs);
315 hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
317 /* update next bnode header */
319 next_node->prev = new_node->this;
320 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
321 node_desc.prev = cpu_to_be32(next_node->prev);
322 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
323 hfs_bnode_put(next_node);
324 } else if (node->this == tree->leaf_tail) {
325 /* if there is no next node, this might be the new tail */
326 tree->leaf_tail = new_node->this;
327 mark_inode_dirty(tree->inode);
330 hfs_bnode_dump(node);
331 hfs_bnode_dump(new_node);
337 static int hfs_brec_update_parent(struct hfs_find_data *fd)
339 struct hfs_btree *tree;
340 struct hfs_bnode *node, *new_node, *parent;
342 int rec, rec_off, end_rec_off;
343 int start_off, end_off;
352 parent = hfs_bnode_find(tree, node->parent);
354 return PTR_ERR(parent);
355 __hfs_brec_find(parent, fd);
356 hfs_bnode_dump(parent);
359 /* size difference between old and new key */
360 if (tree->attributes & HFS_TREE_VARIDXKEYS)
361 newkeylen = hfs_bnode_read_u16(node, 14) + 2;
363 fd->keylength = newkeylen = tree->max_key_len + 2;
364 dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen);
366 rec_off = tree->node_size - (rec + 2) * 2;
367 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
368 diff = newkeylen - fd->keylength;
372 end_off = hfs_bnode_read_u16(parent, end_rec_off);
373 if (end_rec_off - end_off < diff) {
375 printk(KERN_DEBUG "hfs: splitting index node...\n");
377 new_node = hfs_bnode_split(fd);
378 if (IS_ERR(new_node))
379 return PTR_ERR(new_node);
382 rec_off = tree->node_size - (rec + 2) * 2;
383 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
387 end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
388 hfs_bnode_write_u16(parent, rec_off, start_off + diff);
389 start_off -= 4; /* move previous cnid too */
391 while (rec_off > end_rec_off) {
393 end_off = hfs_bnode_read_u16(parent, rec_off);
394 hfs_bnode_write_u16(parent, rec_off, end_off + diff);
396 hfs_bnode_move(parent, start_off + diff, start_off,
397 end_off - start_off);
399 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
400 hfs_bnode_dump(parent);
408 fd->bnode = hfs_bnode_find(tree, new_node->parent);
409 /* create index key and entry */
410 hfs_bnode_read_key(new_node, fd->search_key, 14);
411 cnid = cpu_to_be32(new_node->this);
413 __hfs_brec_find(fd->bnode, fd);
414 hfs_brec_insert(fd, &cnid, sizeof(cnid));
415 hfs_bnode_put(fd->bnode);
416 hfs_bnode_put(new_node);
419 if (new_node == node)
421 /* restore search_key */
422 hfs_bnode_read_key(node, fd->search_key, 14);
426 if (!rec && node->parent)
433 static int hfs_btree_inc_height(struct hfs_btree *tree)
435 struct hfs_bnode *node, *new_node;
436 struct hfs_bnode_desc node_desc;
442 node = hfs_bnode_find(tree, tree->root);
444 return PTR_ERR(node);
446 new_node = hfs_bmap_alloc(tree);
447 if (IS_ERR(new_node)) {
449 return PTR_ERR(new_node);
452 tree->root = new_node->this;
454 tree->leaf_head = tree->leaf_tail = new_node->this;
455 new_node->type = HFS_NODE_LEAF;
456 new_node->num_recs = 0;
458 new_node->type = HFS_NODE_INDEX;
459 new_node->num_recs = 1;
461 new_node->parent = 0;
464 new_node->height = ++tree->depth;
466 node_desc.next = cpu_to_be32(new_node->next);
467 node_desc.prev = cpu_to_be32(new_node->prev);
468 node_desc.type = new_node->type;
469 node_desc.height = new_node->height;
470 node_desc.num_recs = cpu_to_be16(new_node->num_recs);
471 node_desc.reserved = 0;
472 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
474 rec = tree->node_size - 2;
475 hfs_bnode_write_u16(new_node, rec, 14);
478 /* insert old root idx into new root */
479 node->parent = tree->root;
480 if (node->type == HFS_NODE_LEAF ||
481 tree->attributes & HFS_TREE_VARIDXKEYS)
482 key_size = hfs_bnode_read_u16(node, 14) + 2;
484 key_size = tree->max_key_len + 2;
485 hfs_bnode_copy(new_node, 14, node, 14, key_size);
487 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
488 key_size = tree->max_key_len + 2;
489 hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
491 cnid = cpu_to_be32(node->this);
492 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
495 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
499 hfs_bnode_put(new_node);
500 mark_inode_dirty(tree->inode);