/* Return allocated copy of node found, set recnum to best record */
int hfsplus_btree_find(struct hfsplus_find_data *fd)
{
hfsplus_btree *tree;
hfsplus_bnode *bnode;
u32 data, nidx, parent;
int height, err;
tree = fd->tree;
if (fd->bnode)
hfsplus_put_bnode(fd->bnode);
fd->bnode = NULL;
fd->exact = 0;
nidx = tree->root;
if (!nidx)
return -ENOENT;
height = tree->depth;
err = 0;
parent = 0;
for (;;) {
bnode = hfsplus_find_bnode(tree, nidx);
if (!bnode) {
err = -EIO;
break;
}
if (bnode->height != height)
goto invalid;
if (bnode->kind != (--height ? HFSPLUS_NODE_NDX : HFSPLUS_NODE_LEAF))
goto invalid;
bnode->parent = parent;
hfsplus_find_rec(bnode, fd);
if (fd->record < 0) {
err = -ENOENT;
goto release;
}
if (!height) {
if (!fd->exact)
err = -ENOENT;
break;
}
parent = nidx;
hfsplus_bnode_readbytes(bnode, &data, fd->entryoffset, 4);
nidx = be32_to_cpu(data);
hfsplus_put_bnode(bnode);
}
fd->bnode = bnode;
return err;
invalid:
printk("HFS+-fs: inconsistency in B*Tree\n");
err = -EIO;
release:
hfsplus_put_bnode(bnode);
return err;
}
int hfsplus_btree_find_entry(struct hfsplus_find_data *fd,
void *entry, int entry_len)
{
int res;
res = hfsplus_btree_find(fd);
if (res)
return res;
if (fd->entrylength > entry_len)
return -EINVAL;
hfsplus_bnode_readbytes(fd->bnode, entry, fd->entryoffset, fd->entrylength);
return 0;
}
/* Find the record in bnode that best matches key (not greater than...)*/
void hfsplus_find_rec(hfsplus_bnode *bnode, struct hfsplus_find_data *fd)
{
int cmpval;
u16 off, len, keylen;
int rec;
int b, e;
b = 0;
e = bnode->num_recs - 1;
do {
rec = (e + b) / 2;
len = hfsplus_brec_lenoff(bnode, rec, &off);
keylen = hfsplus_brec_keylen(bnode, rec);
hfsplus_bnode_readbytes(bnode, fd->key, off, keylen);
cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
if (!cmpval) {
fd->exact = 1;
e = rec;
break;
}
if (cmpval < 0)
b = rec + 1;
else
e = rec - 1;
} while (b <= e);
//printk("%d: %d,%d,%d\n", bnode->this, b, e, rec);
if (rec != e && e >= 0) {
len = hfsplus_brec_lenoff(bnode, e, &off);
keylen = hfsplus_brec_keylen(bnode, e);
hfsplus_bnode_readbytes(bnode, fd->key, off, keylen);
}
fd->record = e;
fd->keyoffset = off;
fd->keylength = keylen;
fd->entryoffset = off + keylen;
fd->entrylength = len - keylen;
}
int hfsplus_btiter_move(struct hfsplus_find_data *fd, int cnt)
{
struct hfsplus_btree *tree;
hfsplus_bnode *bnode;
int idx, res = 0;
u16 off, len, keylen;
bnode = fd->bnode;
tree = bnode->tree;
if (cnt < -0xFFFF || cnt > 0xFFFF)
return -EINVAL;
if (cnt < 0) {
cnt = -cnt;
while (cnt > fd->record) {
cnt -= fd->record + 1;
fd->record = bnode->num_recs - 1;
idx = bnode->prev;
if (!idx) {
res = -ENOENT;
goto out;
}
hfsplus_put_bnode(bnode);
bnode = hfsplus_find_bnode(tree, idx);
if (!bnode) {
res = -EIO;
goto out;
}
}
fd->record -= cnt;
} else {
while (cnt >= bnode->num_recs - fd->record) {
cnt -= bnode->num_recs - fd->record;
fd->record = 0;
idx = bnode->next;
if (!idx) {
res = -ENOENT;
goto out;
}
hfsplus_put_bnode(bnode);
bnode = hfsplus_find_bnode(tree, idx);
if (!bnode) {
res = -EIO;
goto out;
}
}
fd->record += cnt;
}
len = hfsplus_brec_lenoff(bnode, fd->record, &off);
keylen = hfsplus_brec_keylen(bnode, fd->record);
fd->keyoffset = off;
fd->keylength = keylen;
fd->entryoffset = off + keylen;
fd->entrylength = len - keylen;
hfsplus_bnode_readbytes(bnode, fd->key, off, keylen);
out:
fd->bnode = bnode;
return res;
}