2 * linux/fs/hfsplus/bfind.c
5 * Brad Boyer (flar@allandria.com)
6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 * Search routines for btrees
11 #include <linux/slab.h>
12 #include "hfsplus_fs.h"
14 int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
20 ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
24 fd->key = ptr + tree->max_key_len + 2;
25 dprint(DBG_BNODE_REFS, "find_init: %d (%p)\n",
26 tree->cnid, __builtin_return_address(0));
28 case HFSPLUS_CAT_CNID:
29 mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
31 case HFSPLUS_EXT_CNID:
32 mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
34 case HFSPLUS_ATTR_CNID:
35 mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
43 void hfs_find_exit(struct hfs_find_data *fd)
45 hfs_bnode_put(fd->bnode);
46 kfree(fd->search_key);
47 dprint(DBG_BNODE_REFS, "find_exit: %d (%p)\n",
48 fd->tree->cnid, __builtin_return_address(0));
49 mutex_unlock(&fd->tree->tree_lock);
53 int hfs_find_1st_rec_by_cnid(struct hfs_bnode *bnode,
54 struct hfs_find_data *fd,
59 __be32 cur_cnid, search_cnid;
61 if (bnode->tree->cnid == HFSPLUS_EXT_CNID) {
62 cur_cnid = fd->key->ext.cnid;
63 search_cnid = fd->search_key->ext.cnid;
64 } else if (bnode->tree->cnid == HFSPLUS_CAT_CNID) {
65 cur_cnid = fd->key->cat.parent;
66 search_cnid = fd->search_key->cat.parent;
67 } else if (bnode->tree->cnid == HFSPLUS_ATTR_CNID) {
68 cur_cnid = fd->key->attr.cnid;
69 search_cnid = fd->search_key->attr.cnid;
73 if (cur_cnid == search_cnid) {
75 if ((*begin) == (*end))
78 if (be32_to_cpu(cur_cnid) < be32_to_cpu(search_cnid))
79 (*begin) = (*cur_rec) + 1;
81 (*end) = (*cur_rec) - 1;
87 int hfs_find_rec_by_key(struct hfs_bnode *bnode,
88 struct hfs_find_data *fd,
95 cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
101 (*begin) = (*cur_rec) + 1;
103 *(end) = (*cur_rec) - 1;
108 /* Find the record in bnode that best matches key (not greater than...)*/
109 int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd,
110 search_strategy_t rec_found)
112 u16 off, len, keylen;
121 e = bnode->num_recs - 1;
125 len = hfs_brec_lenoff(bnode, rec, &off);
126 keylen = hfs_brec_keylen(bnode, rec);
131 hfs_bnode_read(bnode, fd->key, off, keylen);
132 if (rec_found(bnode, fd, &b, &e, &rec)) {
138 if (rec != e && e >= 0) {
139 len = hfs_brec_lenoff(bnode, e, &off);
140 keylen = hfs_brec_keylen(bnode, e);
145 hfs_bnode_read(bnode, fd->key, off, keylen);
151 fd->keylength = keylen;
152 fd->entryoffset = off + keylen;
153 fd->entrylength = len - keylen;
159 /* Traverse a B*Tree from the root to a leaf finding best fit to key */
160 /* Return allocated copy of node found, set recnum to best record */
161 int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
163 struct hfs_btree *tree;
164 struct hfs_bnode *bnode;
171 hfs_bnode_put(fd->bnode);
176 height = tree->depth;
180 bnode = hfs_bnode_find(tree, nidx);
182 res = PTR_ERR(bnode);
186 if (bnode->height != height)
188 if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
190 bnode->parent = parent;
192 res = __hfs_brec_find(bnode, fd, do_key_compare);
199 hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
200 nidx = be32_to_cpu(data);
201 hfs_bnode_put(bnode);
207 printk(KERN_ERR "hfs: inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
208 height, bnode->height, bnode->type, nidx, parent);
211 hfs_bnode_put(bnode);
215 int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)
219 res = hfs_brec_find(fd, hfs_find_rec_by_key);
222 if (fd->entrylength > rec_len)
224 hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
228 int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
230 struct hfs_btree *tree;
231 struct hfs_bnode *bnode;
233 u16 off, len, keylen;
240 while (cnt > fd->record) {
241 cnt -= fd->record + 1;
242 fd->record = bnode->num_recs - 1;
248 hfs_bnode_put(bnode);
249 bnode = hfs_bnode_find(tree, idx);
251 res = PTR_ERR(bnode);
258 while (cnt >= bnode->num_recs - fd->record) {
259 cnt -= bnode->num_recs - fd->record;
266 hfs_bnode_put(bnode);
267 bnode = hfs_bnode_find(tree, idx);
269 res = PTR_ERR(bnode);
277 len = hfs_brec_lenoff(bnode, fd->record, &off);
278 keylen = hfs_brec_keylen(bnode, fd->record);
284 fd->keylength = keylen;
285 fd->entryoffset = off + keylen;
286 fd->entrylength = len - keylen;
287 hfs_bnode_read(bnode, fd->key, off, keylen);