[mirror_ubuntu-hirsute-kernel.git] / fs / hfs / brec.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hfs/brec.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Handle individual btree records
 */

#include "btree.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 *tree);

/* 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)) {
		if (node->tree->attributes & HFS_TREE_BIGKEYS)
			retval = node->tree->max_key_len + 2;
		else
			retval = node->tree->max_key_len + 1;
	} 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;
			if (retval > node->tree->max_key_len + 2) {
				pr_err("keylen %d too large\n", retval);
				retval = 0;
			}
		} else {
			retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
			if (retval > node->tree->max_key_len + 1) {
				pr_err("keylen %d too large\n", retval);
				retval = 0;
			}
		}
	}
	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);
		node = hfs_bnode_find(tree, tree->leaf_head);
		if (IS_ERR(node))
			return PTR_ERR(node);
		fd->bnode = node;
		fd->record = -1;
	}
	new_node = NULL;
	key_len = (fd->search_key->key_len | 1) + 1;
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;
	hfs_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);

	/*
	 * update parent key if we inserted a key
	 * at the start of the node and it is not the new node
	 */
	if (!rec && new_node != node) {
		hfs_bnode_read_key(node, fd->search_key, data_off + size);
		hfs_brec_update_parent(fd);
	}

	if (new_node) {
		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 = fd->search_key->key_len + 1;
		else {
			fd->search_key->key_len = tree->max_key_len;
			key_len = tree->max_key_len + 1;
		}
		goto again;
	}

	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);
	hfs_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, *next_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);
	hfs_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;

	if (node->next)
		next_node = hfs_bnode_find(tree, node->next);
	else
		next_node = NULL;

	if (IS_ERR(next_node)) {
		hfs_bnode_put(node);
		hfs_bnode_put(new_node);
		return next_node;
	}

	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);
		if (next_node)
			hfs_bnode_put(next_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 (next_node) {
		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);
	if (fd->record < 0)
		return -ENOENT;
	hfs_bnode_dump(parent);
	rec = fd->record;

	/* size difference between old and new key */
	if (tree->attributes & HFS_TREE_VARIDXKEYS)
		newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1;
	else
		fd->keylength = newkeylen = tree->max_key_len + 1;
	hfs_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 "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);
	if (!(tree->attributes & HFS_TREE_VARIDXKEYS))
		hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1);
	hfs_bnode_dump(parent);

	hfs_bnode_put(node);
	node = parent;

	if (new_node) {
		__be32 cnid;

		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 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_u8(node, 14) + 1;
		else
			key_size = tree->max_key_len + 1;
		hfs_bnode_copy(new_node, 14, node, 14, key_size);

		if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
			key_size = tree->max_key_len + 1;
			hfs_bnode_write_u8(new_node, 14, tree->max_key_len);
		}
		key_size = (key_size + 1) & -2;
		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;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/hfs/brec.c
	4	*
	5	* Copyright (C) 2001
	6	* Brad Boyer (flar@allandria.com)
	7	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	8	*
	9	* Handle individual btree records
	10	*/
	11
	12	#include "btree.h"
	13
	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 *tree);
	17
	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)
	20	{
	21	__be16 retval[2];
	22	u16 dataoff;
	23
	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;
	28	}
	29
	30	/* Get the length of the key from a keyed record */
	31	u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
	32	{
	33	u16 retval, recoff;
	34
	35	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
	36	return 0;
	37
	38	if ((node->type == HFS_NODE_INDEX) &&
	39	!(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
	40	if (node->tree->attributes & HFS_TREE_BIGKEYS)
	41	retval = node->tree->max_key_len + 2;
	42	else
	43	retval = node->tree->max_key_len + 1;
	44	} else {
	45	recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
	46	if (!recoff)
	47	return 0;
cf059462	48	if (node->tree->attributes & HFS_TREE_BIGKEYS) {
1da177e4	49	retval = hfs_bnode_read_u16(node, recoff) + 2;
cf059462	50	if (retval > node->tree->max_key_len + 2) {
d6142673	51	pr_err("keylen %d too large\n", retval);
55581d01	52	retval = 0;
cf059462 ES	53	}
cf059462 ES	54	} else {
1da177e4	55	retval = (hfs_bnode_read_u8(node, recoff) \| 1) + 1;
cf059462	56	if (retval > node->tree->max_key_len + 1) {
d6142673	57	pr_err("keylen %d too large\n", retval);
55581d01	58	retval = 0;
cf059462 ES	59	}
cf059462 ES	60	}
1da177e4 LT	61	}
	62	return retval;
	63	}
	64
	65	int hfs_brec_insert(struct hfs_find_data fd, void entry, int entry_len)
	66	{
	67	struct hfs_btree *tree;
	68	struct hfs_bnode node, new_node;
	69	int size, key_len, rec;
	70	int data_off, end_off;
	71	int idx_rec_off, data_rec_off, end_rec_off;
	72	__be32 cnid;
	73
	74	tree = fd->tree;
	75	if (!fd->bnode) {
	76	if (!tree->root)
	77	hfs_btree_inc_height(tree);
dc257279 EF	78	node = hfs_bnode_find(tree, tree->leaf_head);
	79	if (IS_ERR(node))
	80	return PTR_ERR(node);
	81	fd->bnode = node;
1da177e4 LT	82	fd->record = -1;
	83	}
	84	new_node = NULL;
	85	key_len = (fd->search_key->key_len \| 1) + 1;
	86	again:
	87	/* new record idx and complete record size */
	88	rec = fd->record + 1;
	89	size = key_len + entry_len;
	90
	91	node = fd->bnode;
	92	hfs_bnode_dump(node);
	93	/* get last offset */
	94	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
	95	end_off = hfs_bnode_read_u16(node, end_rec_off);
	96	end_rec_off -= 2;
c2b3e1f7 JP	97	hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
c2b3e1f7 JP	98	rec, size, end_off, end_rec_off);
1da177e4 LT	99	if (size > end_rec_off - end_off) {
	100	if (new_node)
	101	panic("not enough room!\n");
	102	new_node = hfs_bnode_split(fd);
	103	if (IS_ERR(new_node))
	104	return PTR_ERR(new_node);
	105	goto again;
	106	}
	107	if (node->type == HFS_NODE_LEAF) {
	108	tree->leaf_count++;
	109	mark_inode_dirty(tree->inode);
	110	}
	111	node->num_recs++;
	112	/* write new last offset */
	113	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
	114	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
	115	data_off = end_off;
	116	data_rec_off = end_rec_off + 2;
	117	idx_rec_off = tree->node_size - (rec + 1) * 2;
	118	if (idx_rec_off == data_rec_off)
	119	goto skip;
	120	/* move all following entries */
	121	do {
	122	data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
	123	hfs_bnode_write_u16(node, data_rec_off, data_off + size);
	124	data_rec_off += 2;
	125	} while (data_rec_off < idx_rec_off);
	126
	127	/* move data away */
	128	hfs_bnode_move(node, data_off + size, data_off,
	129	end_off - data_off);
	130
	131	skip:
	132	hfs_bnode_write(node, fd->search_key, data_off, key_len);
	133	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
	134	hfs_bnode_dump(node);
	135
b4cc0efe HTL	136	/*
	137	* update parent key if we inserted a key
	138	* at the start of the node and it is not the new node
	139	*/
	140	if (!rec && new_node != node) {
	141	hfs_bnode_read_key(node, fd->search_key, data_off + size);
	142	hfs_brec_update_parent(fd);
	143	}
1da177e4	144
b4cc0efe	145	if (new_node) {
1da177e4 LT	146	hfs_bnode_put(fd->bnode);
	147	if (!new_node->parent) {
	148	hfs_btree_inc_height(tree);
	149	new_node->parent = tree->root;
	150	}
	151	fd->bnode = hfs_bnode_find(tree, new_node->parent);
	152
	153	/* create index data entry */
	154	cnid = cpu_to_be32(new_node->this);
	155	entry = &cnid;
	156	entry_len = sizeof(cnid);
	157
	158	/* get index key */
	159	hfs_bnode_read_key(new_node, fd->search_key, 14);
	160	__hfs_brec_find(fd->bnode, fd);
	161
	162	hfs_bnode_put(new_node);
	163	new_node = NULL;
	164
	165	if (tree->attributes & HFS_TREE_VARIDXKEYS)
	166	key_len = fd->search_key->key_len + 1;
	167	else {
	168	fd->search_key->key_len = tree->max_key_len;
	169	key_len = tree->max_key_len + 1;
	170	}
	171	goto again;
	172	}
	173
1da177e4 LT	174	return 0;
	175	}
	176
	177	int hfs_brec_remove(struct hfs_find_data *fd)
	178	{
	179	struct hfs_btree *tree;
	180	struct hfs_bnode node, parent;
	181	int end_off, rec_off, data_off, size;
	182
	183	tree = fd->tree;
	184	node = fd->bnode;
	185	again:
	186	rec_off = tree->node_size - (fd->record + 2) * 2;
	187	end_off = tree->node_size - (node->num_recs + 1) * 2;
	188
	189	if (node->type == HFS_NODE_LEAF) {
	190	tree->leaf_count--;
	191	mark_inode_dirty(tree->inode);
	192	}
	193	hfs_bnode_dump(node);
c2b3e1f7 JP	194	hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
c2b3e1f7 JP	195	fd->record, fd->keylength + fd->entrylength);
1da177e4 LT	196	if (!--node->num_recs) {
	197	hfs_bnode_unlink(node);
	198	if (!node->parent)
	199	return 0;
	200	parent = hfs_bnode_find(tree, node->parent);
	201	if (IS_ERR(parent))
	202	return PTR_ERR(parent);
	203	hfs_bnode_put(node);
	204	node = fd->bnode = parent;
	205
	206	__hfs_brec_find(node, fd);
	207	goto again;
	208	}
	209	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
	210
	211	if (rec_off == end_off)
	212	goto skip;
	213	size = fd->keylength + fd->entrylength;
	214
	215	do {
	216	data_off = hfs_bnode_read_u16(node, rec_off);
	217	hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
	218	rec_off -= 2;
	219	} while (rec_off >= end_off);
	220
	221	/* fill hole */
	222	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
	223	data_off - fd->keyoffset - size);
	224	skip:
	225	hfs_bnode_dump(node);
	226	if (!fd->record)
	227	hfs_brec_update_parent(fd);
	228	return 0;
	229	}
	230
	231	static struct hfs_bnode hfs_bnode_split(struct hfs_find_data fd)
	232	{
	233	struct hfs_btree *tree;
3d10a15d	234	struct hfs_bnode node, new_node, *next_node;
1da177e4 LT	235	struct hfs_bnode_desc node_desc;
	236	int num_recs, new_rec_off, new_off, old_rec_off;
	237	int data_start, data_end, size;
	238
	239	tree = fd->tree;
	240	node = fd->bnode;
	241	new_node = hfs_bmap_alloc(tree);
	242	if (IS_ERR(new_node))
	243	return new_node;
	244	hfs_bnode_get(node);
c2b3e1f7	245	hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
1da177e4 LT	246	node->this, new_node->this, node->next);
	247	new_node->next = node->next;
	248	new_node->prev = node->this;
	249	new_node->parent = node->parent;
	250	new_node->type = node->type;
	251	new_node->height = node->height;
	252
3d10a15d AV	253	if (node->next)
	254	next_node = hfs_bnode_find(tree, node->next);
	255	else
	256	next_node = NULL;
	257
	258	if (IS_ERR(next_node)) {
	259	hfs_bnode_put(node);
	260	hfs_bnode_put(new_node);
	261	return next_node;
	262	}
	263
1da177e4 LT	264	size = tree->node_size / 2 - node->num_recs * 2 - 14;
	265	old_rec_off = tree->node_size - 4;
	266	num_recs = 1;
	267	for (;;) {
	268	data_start = hfs_bnode_read_u16(node, old_rec_off);
	269	if (data_start > size)
	270	break;
	271	old_rec_off -= 2;
	272	if (++num_recs < node->num_recs)
	273	continue;
	274	/* panic? */
	275	hfs_bnode_put(node);
	276	hfs_bnode_put(new_node);
3d10a15d AV	277	if (next_node)
3d10a15d AV	278	hfs_bnode_put(next_node);
1da177e4 LT	279	return ERR_PTR(-ENOSPC);
	280	}
	281
	282	if (fd->record + 1 < num_recs) {
	283	/* new record is in the lower half,
	284	* so leave some more space there
	285	*/
	286	old_rec_off += 2;
	287	num_recs--;
	288	data_start = hfs_bnode_read_u16(node, old_rec_off);
	289	} else {
	290	hfs_bnode_put(node);
	291	hfs_bnode_get(new_node);
	292	fd->bnode = new_node;
	293	fd->record -= num_recs;
	294	fd->keyoffset -= data_start - 14;
	295	fd->entryoffset -= data_start - 14;
	296	}
	297	new_node->num_recs = node->num_recs - num_recs;
	298	node->num_recs = num_recs;
	299
	300	new_rec_off = tree->node_size - 2;
	301	new_off = 14;
	302	size = data_start - new_off;
	303	num_recs = new_node->num_recs;
	304	data_end = data_start;
	305	while (num_recs) {
	306	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	307	old_rec_off -= 2;
	308	new_rec_off -= 2;
	309	data_end = hfs_bnode_read_u16(node, old_rec_off);
	310	new_off = data_end - size;
	311	num_recs--;
	312	}
	313	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	314	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
	315
	316	/* update new bnode header */
	317	node_desc.next = cpu_to_be32(new_node->next);
	318	node_desc.prev = cpu_to_be32(new_node->prev);
	319	node_desc.type = new_node->type;
	320	node_desc.height = new_node->height;
	321	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	322	node_desc.reserved = 0;
	323	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
	324
	325	/* update previous bnode header */
	326	node->next = new_node->this;
	327	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
	328	node_desc.next = cpu_to_be32(node->next);
	329	node_desc.num_recs = cpu_to_be16(node->num_recs);
	330	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
	331
	332	/* update next bnode header */
3d10a15d	333	if (next_node) {
1da177e4 LT	334	next_node->prev = new_node->this;
	335	hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
	336	node_desc.prev = cpu_to_be32(next_node->prev);
	337	hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
	338	hfs_bnode_put(next_node);
	339	} else if (node->this == tree->leaf_tail) {
	340	/* if there is no next node, this might be the new tail */
	341	tree->leaf_tail = new_node->this;
	342	mark_inode_dirty(tree->inode);
	343	}
	344
	345	hfs_bnode_dump(node);
	346	hfs_bnode_dump(new_node);
	347	hfs_bnode_put(node);
	348
	349	return new_node;
	350	}
	351
	352	static int hfs_brec_update_parent(struct hfs_find_data *fd)
	353	{
	354	struct hfs_btree *tree;
	355	struct hfs_bnode node, new_node, *parent;
	356	int newkeylen, diff;
	357	int rec, rec_off, end_rec_off;
	358	int start_off, end_off;
	359
	360	tree = fd->tree;
	361	node = fd->bnode;
	362	new_node = NULL;
	363	if (!node->parent)
	364	return 0;
	365
	366	again:
	367	parent = hfs_bnode_find(tree, node->parent);
	368	if (IS_ERR(parent))
	369	return PTR_ERR(parent);
	370	__hfs_brec_find(parent, fd);
b4cc0efe HTL	371	if (fd->record < 0)
b4cc0efe HTL	372	return -ENOENT;
1da177e4 LT	373	hfs_bnode_dump(parent);
	374	rec = fd->record;
	375
	376	/* size difference between old and new key */
	377	if (tree->attributes & HFS_TREE_VARIDXKEYS)
	378	newkeylen = (hfs_bnode_read_u8(node, 14) \| 1) + 1;
	379	else
	380	fd->keylength = newkeylen = tree->max_key_len + 1;
c2b3e1f7 JP	381	hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
c2b3e1f7 JP	382	rec, fd->keylength, newkeylen);
1da177e4 LT	383
	384	rec_off = tree->node_size - (rec + 2) * 2;
	385	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
	386	diff = newkeylen - fd->keylength;
	387	if (!diff)
	388	goto skip;
	389	if (diff > 0) {
	390	end_off = hfs_bnode_read_u16(parent, end_rec_off);
	391	if (end_rec_off - end_off < diff) {
	392
d6142673	393	printk(KERN_DEBUG "splitting index node...\n");
1da177e4 LT	394	fd->bnode = parent;
	395	new_node = hfs_bnode_split(fd);
	396	if (IS_ERR(new_node))
	397	return PTR_ERR(new_node);
	398	parent = fd->bnode;
	399	rec = fd->record;
	400	rec_off = tree->node_size - (rec + 2) * 2;
	401	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
	402	}
	403	}
	404
	405	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
	406	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
	407	start_off -= 4; /* move previous cnid too */
	408
	409	while (rec_off > end_rec_off) {
	410	rec_off -= 2;
	411	end_off = hfs_bnode_read_u16(parent, rec_off);
	412	hfs_bnode_write_u16(parent, rec_off, end_off + diff);
	413	}
	414	hfs_bnode_move(parent, start_off + diff, start_off,
	415	end_off - start_off);
	416	skip:
	417	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
	418	if (!(tree->attributes & HFS_TREE_VARIDXKEYS))
	419	hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1);
	420	hfs_bnode_dump(parent);
	421
	422	hfs_bnode_put(node);
	423	node = parent;
	424
	425	if (new_node) {
	426	__be32 cnid;
	427
d057c036 EF	428	if (!new_node->parent) {
	429	hfs_btree_inc_height(tree);
	430	new_node->parent = tree->root;
	431	}
1da177e4 LT	432	fd->bnode = hfs_bnode_find(tree, new_node->parent);
	433	/* create index key and entry */
	434	hfs_bnode_read_key(new_node, fd->search_key, 14);
	435	cnid = cpu_to_be32(new_node->this);
	436
	437	__hfs_brec_find(fd->bnode, fd);
	438	hfs_brec_insert(fd, &cnid, sizeof(cnid));
	439	hfs_bnode_put(fd->bnode);
	440	hfs_bnode_put(new_node);
	441
	442	if (!rec) {
	443	if (new_node == node)
	444	goto out;
	445	/* restore search_key */
	446	hfs_bnode_read_key(node, fd->search_key, 14);
	447	}
	448	}
	449
	450	if (!rec && node->parent)
	451	goto again;
	452	out:
	453	fd->bnode = node;
	454	return 0;
	455	}
	456
	457	static int hfs_btree_inc_height(struct hfs_btree *tree)
	458	{
	459	struct hfs_bnode node, new_node;
	460	struct hfs_bnode_desc node_desc;
	461	int key_size, rec;
	462	__be32 cnid;
	463
	464	node = NULL;
	465	if (tree->root) {
	466	node = hfs_bnode_find(tree, tree->root);
	467	if (IS_ERR(node))
	468	return PTR_ERR(node);
	469	}
	470	new_node = hfs_bmap_alloc(tree);
	471	if (IS_ERR(new_node)) {
	472	hfs_bnode_put(node);
	473	return PTR_ERR(new_node);
	474	}
	475
	476	tree->root = new_node->this;
	477	if (!tree->depth) {
	478	tree->leaf_head = tree->leaf_tail = new_node->this;
	479	new_node->type = HFS_NODE_LEAF;
	480	new_node->num_recs = 0;
	481	} else {
	482	new_node->type = HFS_NODE_INDEX;
	483	new_node->num_recs = 1;
	484	}
	485	new_node->parent = 0;
	486	new_node->next = 0;
	487	new_node->prev = 0;
	488	new_node->height = ++tree->depth;
	489
	490	node_desc.next = cpu_to_be32(new_node->next);
	491	node_desc.prev = cpu_to_be32(new_node->prev);
	492	node_desc.type = new_node->type;
	493	node_desc.height = new_node->height;
	494	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	495	node_desc.reserved = 0;
496	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
497
498	rec = tree->node_size - 2;
499	hfs_bnode_write_u16(new_node, rec, 14);
500
501	if (node) {
502	/* insert old root idx into new root */
503	node->parent = tree->root;
504	if (node->type == HFS_NODE_LEAF \|\|
505	tree->attributes & HFS_TREE_VARIDXKEYS)
506	key_size = hfs_bnode_read_u8(node, 14) + 1;
507	else
508	key_size = tree->max_key_len + 1;
509	hfs_bnode_copy(new_node, 14, node, 14, key_size);
510
511	if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
512	key_size = tree->max_key_len + 1;
513	hfs_bnode_write_u8(new_node, 14, tree->max_key_len);
514	}
515	key_size = (key_size + 1) & -2;
516	cnid = cpu_to_be32(node->this);
517	hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
518
519	rec -= 2;
520	hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
521
522	hfs_bnode_put(node);
523	}
524	hfs_bnode_put(new_node);
525	mark_inode_dirty(tree->inode);
526
527	return 0;
528	}