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DEFINITIONS
This source file includes following definitions.
- hfs_brec_lenoff
- hfs_brec_keylen
- hfs_brec_insert
- hfs_brec_remove
- hfs_bnode_split
- hfs_brec_update_parent
- hfs_btree_inc_height
/*
* linux/fs/hfsplus/brec.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
* Handle individual btree records
*/
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
static int hfs_brec_update_parent(struct hfs_find_data *fd);
static int hfs_btree_inc_height(struct hfs_btree *);
/* Get the length and offset of the given record in the given node */
u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
{
__be16 retval[2];
u16 dataoff;
dataoff = node->tree->node_size - (rec + 2) * 2;
hfs_bnode_read(node, retval, dataoff, 4);
*off = be16_to_cpu(retval[1]);
return be16_to_cpu(retval[0]) - *off;
}
/* Get the length of the key from a keyed record */
u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
{
u16 retval, recoff;
if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
return 0;
if ((node->type == HFS_NODE_INDEX) &&
!(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
retval = node->tree->max_key_len + 2;
} else {
recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
if (!recoff)
return 0;
if (node->tree->attributes & HFS_TREE_BIGKEYS)
retval = hfs_bnode_read_u16(node, recoff) + 2;
else
retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
}
return retval;
}
int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
{
struct hfs_btree *tree;
struct hfs_bnode *node, *new_node;
int size, key_len, rec;
int data_off, end_off;
int idx_rec_off, data_rec_off, end_rec_off;
__be32 cnid;
tree = fd->tree;
if (!fd->bnode) {
if (!tree->root)
hfs_btree_inc_height(tree);
fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
if (IS_ERR(fd->bnode))
return PTR_ERR(fd->bnode);
fd->record = -1;
}
new_node = NULL;
key_len = be16_to_cpu(fd->search_key->key_len) + 2;
again:
/* new record idx and complete record size */
rec = fd->record + 1;
size = key_len + entry_len;
node = fd->bnode;
hfs_bnode_dump(node);
/* get last offset */
end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
end_off = hfs_bnode_read_u16(node, end_rec_off);
end_rec_off -= 2;
dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off);
if (size > end_rec_off - end_off) {
if (new_node)
panic("not enough room!\n");
new_node = hfs_bnode_split(fd);
if (IS_ERR(new_node))
return PTR_ERR(new_node);
goto again;
}
if (node->type == HFS_NODE_LEAF) {
tree->leaf_count++;
mark_inode_dirty(tree->inode);
}
node->num_recs++;
/* write new last offset */
hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
hfs_bnode_write_u16(node, end_rec_off, end_off + size);
data_off = end_off;
data_rec_off = end_rec_off + 2;
idx_rec_off = tree->node_size - (rec + 1) * 2;
if (idx_rec_off == data_rec_off)
goto skip;
/* move all following entries */
do {
data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
hfs_bnode_write_u16(node, data_rec_off, data_off + size);
data_rec_off += 2;
} while (data_rec_off < idx_rec_off);
/* move data away */
hfs_bnode_move(node, data_off + size, data_off,
end_off - data_off);
skip:
hfs_bnode_write(node, fd->search_key, data_off, key_len);
hfs_bnode_write(node, entry, data_off + key_len, entry_len);
hfs_bnode_dump(node);
if (new_node) {
/* update parent key if we inserted a key
* at the start of the first node
*/
if (!rec && new_node != node)
hfs_brec_update_parent(fd);
hfs_bnode_put(fd->bnode);
if (!new_node->parent) {
hfs_btree_inc_height(tree);
new_node->parent = tree->root;
}
fd->bnode = hfs_bnode_find(tree, new_node->parent);
/* create index data entry */
cnid = cpu_to_be32(new_node->this);
entry = &cnid;
entry_len = sizeof(cnid);
/* get index key */
hfs_bnode_read_key(new_node, fd->search_key, 14);
__hfs_brec_find(fd->bnode, fd);
hfs_bnode_put(new_node);
new_node = NULL;
if (tree->attributes & HFS_TREE_VARIDXKEYS)
key_len = be16_to_cpu(fd->search_key->key_len) + 2;
else {
fd->search_key->key_len = cpu_to_be16(tree->max_key_len);
key_len = tree->max_key_len + 2;
}
goto again;
}
if (!rec)
hfs_brec_update_parent(fd);
return 0;
}
int hfs_brec_remove(struct hfs_find_data *fd)
{
struct hfs_btree *tree;
struct hfs_bnode *node, *parent;
int end_off, rec_off, data_off, size;
tree = fd->tree;
node = fd->bnode;
again:
rec_off = tree->node_size - (fd->record + 2) * 2;
end_off = tree->node_size - (node->num_recs + 1) * 2;
if (node->type == HFS_NODE_LEAF) {
tree->leaf_count--;
mark_inode_dirty(tree->inode);
}
hfs_bnode_dump(node);
dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength);
if (!--node->num_recs) {
hfs_bnode_unlink(node);
if (!node->parent)
return 0;
parent = hfs_bnode_find(tree, node->parent);
if (IS_ERR(parent))
return PTR_ERR(parent);
hfs_bnode_put(node);
node = fd->bnode = parent;
__hfs_brec_find(node, fd);
goto again;
}
hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
if (rec_off == end_off)
goto skip;
size = fd->keylength + fd->entrylength;
do {
data_off = hfs_bnode_read_u16(node, rec_off);
hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
rec_off -= 2;
} while (rec_off >= end_off);
/* fill hole */
hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
data_off - fd->keyoffset - size);
skip:
hfs_bnode_dump(node);
if (!fd->record)
hfs_brec_update_parent(fd);
return 0;
}
static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
{
struct hfs_btree *tree;
struct hfs_bnode *node, *new_node;
struct hfs_bnode_desc node_desc;
int num_recs, new_rec_off, new_off, old_rec_off;
int data_start, data_end, size;
tree = fd->tree;
node = fd->bnode;
new_node = hfs_bmap_alloc(tree);
if (IS_ERR(new_node))
return new_node;
hfs_bnode_get(node);
dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n",
node->this, new_node->this, node->next);
new_node->next = node->next;
new_node->prev = node->this;
new_node->parent = node->parent;
new_node->type = node->type;
new_node->height = node->height;
size = tree->node_size / 2 - node->num_recs * 2 - 14;
old_rec_off = tree->node_size - 4;
num_recs = 1;
for (;;) {
data_start = hfs_bnode_read_u16(node, old_rec_off);
if (data_start > size)
break;
old_rec_off -= 2;
if (++num_recs < node->num_recs)
continue;
/* panic? */
hfs_bnode_put(node);
hfs_bnode_put(new_node);
return ERR_PTR(-ENOSPC);
}
if (fd->record + 1 < num_recs) {
/* new record is in the lower half,
* so leave some more space there
*/
old_rec_off += 2;
num_recs--;
data_start = hfs_bnode_read_u16(node, old_rec_off);
} else {
hfs_bnode_put(node);
hfs_bnode_get(new_node);
fd->bnode = new_node;
fd->record -= num_recs;
fd->keyoffset -= data_start - 14;
fd->entryoffset -= data_start - 14;
}
new_node->num_recs = node->num_recs - num_recs;
node->num_recs = num_recs;
new_rec_off = tree->node_size - 2;
new_off = 14;
size = data_start - new_off;
num_recs = new_node->num_recs;
data_end = data_start;
while (num_recs) {
hfs_bnode_write_u16(new_node, new_rec_off, new_off);
old_rec_off -= 2;
new_rec_off -= 2;
data_end = hfs_bnode_read_u16(node, old_rec_off);
new_off = data_end - size;
num_recs--;
}
hfs_bnode_write_u16(new_node, new_rec_off, new_off);
hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
/* update new bnode header */
node_desc.next = cpu_to_be32(new_node->next);
node_desc.prev = cpu_to_be32(new_node->prev);
node_desc.type = new_node->type;
node_desc.height = new_node->height;
node_desc.num_recs = cpu_to_be16(new_node->num_recs);
node_desc.reserved = 0;
hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
/* update previous bnode header */
node->next = new_node->this;
hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
node_desc.next = cpu_to_be32(node->next);
node_desc.num_recs = cpu_to_be16(node->num_recs);
hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
/* update next bnode header */
if (new_node->next) {
struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next);
next_node->prev = new_node->this;
hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
node_desc.prev = cpu_to_be32(next_node->prev);
hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
hfs_bnode_put(next_node);
} else if (node->this == tree->leaf_tail) {
/* if there is no next node, this might be the new tail */
tree->leaf_tail = new_node->this;
mark_inode_dirty(tree->inode);
}
hfs_bnode_dump(node);
hfs_bnode_dump(new_node);
hfs_bnode_put(node);
return new_node;
}
static int hfs_brec_update_parent(struct hfs_find_data *fd)
{
struct hfs_btree *tree;
struct hfs_bnode *node, *new_node, *parent;
int newkeylen, diff;
int rec, rec_off, end_rec_off;
int start_off, end_off;
tree = fd->tree;
node = fd->bnode;
new_node = NULL;
if (!node->parent)
return 0;
again:
parent = hfs_bnode_find(tree, node->parent);
if (IS_ERR(parent))
return PTR_ERR(parent);
__hfs_brec_find(parent, fd);
hfs_bnode_dump(parent);
rec = fd->record;
/* size difference between old and new key */
if (tree->attributes & HFS_TREE_VARIDXKEYS)
newkeylen = hfs_bnode_read_u16(node, 14) + 2;
else
fd->keylength = newkeylen = tree->max_key_len + 2;
dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen);
rec_off = tree->node_size - (rec + 2) * 2;
end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
diff = newkeylen - fd->keylength;
if (!diff)
goto skip;
if (diff > 0) {
end_off = hfs_bnode_read_u16(parent, end_rec_off);
if (end_rec_off - end_off < diff) {
printk(KERN_DEBUG "hfs: splitting index node...\n");
fd->bnode = parent;
new_node = hfs_bnode_split(fd);
if (IS_ERR(new_node))
return PTR_ERR(new_node);
parent = fd->bnode;
rec = fd->record;
rec_off = tree->node_size - (rec + 2) * 2;
end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
}
}
end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
hfs_bnode_write_u16(parent, rec_off, start_off + diff);
start_off -= 4; /* move previous cnid too */
while (rec_off > end_rec_off) {
rec_off -= 2;
end_off = hfs_bnode_read_u16(parent, rec_off);
hfs_bnode_write_u16(parent, rec_off, end_off + diff);
}
hfs_bnode_move(parent, start_off + diff, start_off,
end_off - start_off);
skip:
hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
hfs_bnode_dump(parent);
hfs_bnode_put(node);
node = parent;
if (new_node) {
__be32 cnid;
fd->bnode = hfs_bnode_find(tree, new_node->parent);
/* create index key and entry */
hfs_bnode_read_key(new_node, fd->search_key, 14);
cnid = cpu_to_be32(new_node->this);
__hfs_brec_find(fd->bnode, fd);
hfs_brec_insert(fd, &cnid, sizeof(cnid));
hfs_bnode_put(fd->bnode);
hfs_bnode_put(new_node);
if (!rec) {
if (new_node == node)
goto out;
/* restore search_key */
hfs_bnode_read_key(node, fd->search_key, 14);
}
}
if (!rec && node->parent)
goto again;
out:
fd->bnode = node;
return 0;
}
static int hfs_btree_inc_height(struct hfs_btree *tree)
{
struct hfs_bnode *node, *new_node;
struct hfs_bnode_desc node_desc;
int key_size, rec;
__be32 cnid;
node = NULL;
if (tree->root) {
node = hfs_bnode_find(tree, tree->root);
if (IS_ERR(node))
return PTR_ERR(node);
}
new_node = hfs_bmap_alloc(tree);
if (IS_ERR(new_node)) {
hfs_bnode_put(node);
return PTR_ERR(new_node);
}
tree->root = new_node->this;
if (!tree->depth) {
tree->leaf_head = tree->leaf_tail = new_node->this;
new_node->type = HFS_NODE_LEAF;
new_node->num_recs = 0;
} else {
new_node->type = HFS_NODE_INDEX;
new_node->num_recs = 1;
}
new_node->parent = 0;
new_node->next = 0;
new_node->prev = 0;
new_node->height = ++tree->depth;
node_desc.next = cpu_to_be32(new_node->next);
node_desc.prev = cpu_to_be32(new_node->prev);
node_desc.type = new_node->type;
node_desc.height = new_node->height;
node_desc.num_recs = cpu_to_be16(new_node->num_recs);
node_desc.reserved = 0;
hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
rec = tree->node_size - 2;
hfs_bnode_write_u16(new_node, rec, 14);
if (node) {
/* insert old root idx into new root */
node->parent = tree->root;
if (node->type == HFS_NODE_LEAF ||
tree->attributes & HFS_TREE_VARIDXKEYS)
key_size = hfs_bnode_read_u16(node, 14) + 2;
else
key_size = tree->max_key_len + 2;
hfs_bnode_copy(new_node, 14, node, 14, key_size);
if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
key_size = tree->max_key_len + 2;
hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
}
cnid = cpu_to_be32(node->this);
hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
rec -= 2;
hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
hfs_bnode_put(node);
}
hfs_bnode_put(new_node);
mark_inode_dirty(tree->inode);
return 0;
}