[linux.git] / fs / hfsplus / brec.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hfsplus/brec.c
 *
 * Copyright (C) 2001
 * Brad Boyer ([email protected])
 * (C) 2003 Ardis Technologies <[email protected]>
 *
 * 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) &&
	   (node->tree->cnid != HFSPLUS_ATTR_CNID)) {
		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 (recoff > node->tree->node_size - 2) {
			pr_err("recoff %d too large\n", recoff);
			return 0;
		}

		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;
		}
	}
	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 = 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;
	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_find_rec_by_key);

		hfs_bnode_put(new_node);
		new_node = NULL;

		if ((tree->attributes & HFS_TREE_VARIDXKEYS) ||
				(tree->cnid == HFSPLUS_ATTR_CNID))
			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;
	}

	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, hfs_find_rec_by_key);
		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, hfs_find_rec_by_key);
	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) ||
				(tree->cnid == HFSPLUS_ATTR_CNID))
		newkeylen = hfs_bnode_read_u16(node, 14) + 2;
	else
		fd->keylength = newkeylen = tree->max_key_len + 2;
	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) {

			hfs_dbg(BNODE_MOD, "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;

		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_find_rec_by_key);
		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);
		}
		new_node = NULL;
	}

	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 ||
				tree->cnid == HFSPLUS_ATTR_CNID)
			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) &&
				(tree->cnid != HFSPLUS_ATTR_CNID)) {
			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;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/hfsplus/brec.c
	4	*
	5	* Copyright (C) 2001
	6	* Brad Boyer ([email protected])
	7	* (C) 2003 Ardis Technologies <[email protected]>
	8	*
	9	* Handle individual btree records
	10	*/
	11
	12	#include "hfsplus_fs.h"
	13	#include "hfsplus_raw.h"
	14
	15	static struct hfs_bnode hfs_bnode_split(struct hfs_find_data fd);
	16	static int hfs_brec_update_parent(struct hfs_find_data *fd);
	17	static int hfs_btree_inc_height(struct hfs_btree *);
	18
	19	/* Get the length and offset of the given record in the given node */
	20	u16 hfs_brec_lenoff(struct hfs_bnode node, u16 rec, u16 off)
	21	{
	22	__be16 retval[2];
	23	u16 dataoff;
	24
	25	dataoff = node->tree->node_size - (rec + 2) * 2;
	26	hfs_bnode_read(node, retval, dataoff, 4);
	27	*off = be16_to_cpu(retval[1]);
	28	return be16_to_cpu(retval[0]) - *off;
	29	}
	30
	31	/* Get the length of the key from a keyed record */
	32	u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
	33	{
	34	u16 retval, recoff;
	35
	36	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
	37	return 0;
	38
	39	if ((node->type == HFS_NODE_INDEX) &&
324ef39a VD	40	!(node->tree->attributes & HFS_TREE_VARIDXKEYS) &&
324ef39a VD	41	(node->tree->cnid != HFSPLUS_ATTR_CNID)) {
1da177e4 LT	42	retval = node->tree->max_key_len + 2;
1da177e4 LT	43	} else {
2753cc28 AS	44	recoff = hfs_bnode_read_u16(node,
2753cc28 AS	45	node->tree->node_size - (rec + 1) * 2);
1da177e4 LT	46	if (!recoff)
1da177e4 LT	47	return 0;
aac4e419	48	if (recoff > node->tree->node_size - 2) {
d6142673	49	pr_err("recoff %d too large\n", recoff);
aac4e419 NA	50	return 0;
aac4e419 NA	51	}
13571a69 CH	52
	53	retval = hfs_bnode_read_u16(node, recoff) + 2;
	54	if (retval > node->tree->max_key_len + 2) {
d6142673	55	pr_err("keylen %d too large\n",
13571a69 CH	56	retval);
13571a69 CH	57	retval = 0;
9250f925	58	}
1da177e4 LT	59	}
	60	return retval;
	61	}
	62
	63	int hfs_brec_insert(struct hfs_find_data fd, void entry, int entry_len)
	64	{
	65	struct hfs_btree *tree;
	66	struct hfs_bnode node, new_node;
	67	int size, key_len, rec;
	68	int data_off, end_off;
	69	int idx_rec_off, data_rec_off, end_rec_off;
	70	__be32 cnid;
	71
	72	tree = fd->tree;
	73	if (!fd->bnode) {
	74	if (!tree->root)
	75	hfs_btree_inc_height(tree);
aba93a92 EF	76	node = hfs_bnode_find(tree, tree->leaf_head);
	77	if (IS_ERR(node))
	78	return PTR_ERR(node);
	79	fd->bnode = node;
1da177e4 LT	80	fd->record = -1;
	81	}
	82	new_node = NULL;
	83	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
	84	again:
	85	/* new record idx and complete record size */
	86	rec = fd->record + 1;
	87	size = key_len + entry_len;
	88
	89	node = fd->bnode;
	90	hfs_bnode_dump(node);
	91	/* get last offset */
	92	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
	93	end_off = hfs_bnode_read_u16(node, end_rec_off);
	94	end_rec_off -= 2;
c2b3e1f7	95	hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
2753cc28	96	rec, size, end_off, end_rec_off);
1da177e4 LT	97	if (size > end_rec_off - end_off) {
	98	if (new_node)
	99	panic("not enough room!\n");
	100	new_node = hfs_bnode_split(fd);
	101	if (IS_ERR(new_node))
	102	return PTR_ERR(new_node);
	103	goto again;
	104	}
	105	if (node->type == HFS_NODE_LEAF) {
	106	tree->leaf_count++;
	107	mark_inode_dirty(tree->inode);
	108	}
	109	node->num_recs++;
	110	/* write new last offset */
2753cc28 AS	111	hfs_bnode_write_u16(node,
	112	offsetof(struct hfs_bnode_desc, num_recs),
	113	node->num_recs);
1da177e4 LT	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
98cf21c6 SA	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
98cf21c6	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);
324ef39a	160	__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);
1da177e4 LT	161
	162	hfs_bnode_put(new_node);
	163	new_node = NULL;
	164
324ef39a VD	165	if ((tree->attributes & HFS_TREE_VARIDXKEYS) \|\|
324ef39a VD	166	(tree->cnid == HFSPLUS_ATTR_CNID))
1da177e4 LT	167	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
1da177e4 LT	168	else {
2753cc28 AS	169	fd->search_key->key_len =
2753cc28 AS	170	cpu_to_be16(tree->max_key_len);
1da177e4 LT	171	key_len = tree->max_key_len + 2;
	172	}
	173	goto again;
	174	}
	175
1da177e4 LT	176	return 0;
	177	}
	178
	179	int hfs_brec_remove(struct hfs_find_data *fd)
	180	{
	181	struct hfs_btree *tree;
	182	struct hfs_bnode node, parent;
	183	int end_off, rec_off, data_off, size;
	184
	185	tree = fd->tree;
	186	node = fd->bnode;
	187	again:
	188	rec_off = tree->node_size - (fd->record + 2) * 2;
	189	end_off = tree->node_size - (node->num_recs + 1) * 2;
	190
	191	if (node->type == HFS_NODE_LEAF) {
	192	tree->leaf_count--;
	193	mark_inode_dirty(tree->inode);
	194	}
	195	hfs_bnode_dump(node);
c2b3e1f7	196	hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
2753cc28	197	fd->record, fd->keylength + fd->entrylength);
1da177e4 LT	198	if (!--node->num_recs) {
	199	hfs_bnode_unlink(node);
	200	if (!node->parent)
	201	return 0;
	202	parent = hfs_bnode_find(tree, node->parent);
	203	if (IS_ERR(parent))
	204	return PTR_ERR(parent);
	205	hfs_bnode_put(node);
	206	node = fd->bnode = parent;
	207
324ef39a	208	__hfs_brec_find(node, fd, hfs_find_rec_by_key);
1da177e4 LT	209	goto again;
1da177e4 LT	210	}
2753cc28 AS	211	hfs_bnode_write_u16(node,
	212	offsetof(struct hfs_bnode_desc, num_recs),
	213	node->num_recs);
1da177e4 LT	214
	215	if (rec_off == end_off)
	216	goto skip;
	217	size = fd->keylength + fd->entrylength;
	218
	219	do {
	220	data_off = hfs_bnode_read_u16(node, rec_off);
	221	hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
	222	rec_off -= 2;
	223	} while (rec_off >= end_off);
	224
	225	/* fill hole */
	226	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
	227	data_off - fd->keyoffset - size);
	228	skip:
	229	hfs_bnode_dump(node);
	230	if (!fd->record)
	231	hfs_brec_update_parent(fd);
	232	return 0;
	233	}
	234
	235	static struct hfs_bnode hfs_bnode_split(struct hfs_find_data fd)
	236	{
	237	struct hfs_btree *tree;
b6b41424	238	struct hfs_bnode node, new_node, *next_node;
1da177e4 LT	239	struct hfs_bnode_desc node_desc;
	240	int num_recs, new_rec_off, new_off, old_rec_off;
	241	int data_start, data_end, size;
	242
	243	tree = fd->tree;
	244	node = fd->bnode;
	245	new_node = hfs_bmap_alloc(tree);
	246	if (IS_ERR(new_node))
	247	return new_node;
	248	hfs_bnode_get(node);
c2b3e1f7	249	hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
1da177e4 LT	250	node->this, new_node->this, node->next);
	251	new_node->next = node->next;
	252	new_node->prev = node->this;
	253	new_node->parent = node->parent;
	254	new_node->type = node->type;
	255	new_node->height = node->height;
	256
b6b41424 AV	257	if (node->next)
	258	next_node = hfs_bnode_find(tree, node->next);
	259	else
	260	next_node = NULL;
	261
	262	if (IS_ERR(next_node)) {
	263	hfs_bnode_put(node);
	264	hfs_bnode_put(new_node);
	265	return next_node;
	266	}
	267
1da177e4 LT	268	size = tree->node_size / 2 - node->num_recs * 2 - 14;
	269	old_rec_off = tree->node_size - 4;
	270	num_recs = 1;
	271	for (;;) {
	272	data_start = hfs_bnode_read_u16(node, old_rec_off);
	273	if (data_start > size)
	274	break;
	275	old_rec_off -= 2;
	276	if (++num_recs < node->num_recs)
	277	continue;
	278	/* panic? */
	279	hfs_bnode_put(node);
	280	hfs_bnode_put(new_node);
b6b41424 AV	281	if (next_node)
b6b41424 AV	282	hfs_bnode_put(next_node);
1da177e4 LT	283	return ERR_PTR(-ENOSPC);
	284	}
	285
	286	if (fd->record + 1 < num_recs) {
	287	/* new record is in the lower half,
	288	* so leave some more space there
	289	*/
	290	old_rec_off += 2;
	291	num_recs--;
	292	data_start = hfs_bnode_read_u16(node, old_rec_off);
	293	} else {
	294	hfs_bnode_put(node);
	295	hfs_bnode_get(new_node);
	296	fd->bnode = new_node;
	297	fd->record -= num_recs;
	298	fd->keyoffset -= data_start - 14;
	299	fd->entryoffset -= data_start - 14;
	300	}
	301	new_node->num_recs = node->num_recs - num_recs;
	302	node->num_recs = num_recs;
	303
	304	new_rec_off = tree->node_size - 2;
	305	new_off = 14;
	306	size = data_start - new_off;
	307	num_recs = new_node->num_recs;
	308	data_end = data_start;
	309	while (num_recs) {
	310	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	311	old_rec_off -= 2;
	312	new_rec_off -= 2;
	313	data_end = hfs_bnode_read_u16(node, old_rec_off);
	314	new_off = data_end - size;
	315	num_recs--;
	316	}
	317	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	318	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
	319
	320	/* update new bnode header */
	321	node_desc.next = cpu_to_be32(new_node->next);
	322	node_desc.prev = cpu_to_be32(new_node->prev);
	323	node_desc.type = new_node->type;
	324	node_desc.height = new_node->height;
	325	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	326	node_desc.reserved = 0;
	327	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
	328
	329	/* update previous bnode header */
	330	node->next = new_node->this;
	331	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
	332	node_desc.next = cpu_to_be32(node->next);
	333	node_desc.num_recs = cpu_to_be16(node->num_recs);
	334	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
	335
	336	/* update next bnode header */
b6b41424	337	if (next_node) {
1da177e4 LT	338	next_node->prev = new_node->this;
	339	hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
	340	node_desc.prev = cpu_to_be32(next_node->prev);
	341	hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
	342	hfs_bnode_put(next_node);
	343	} else if (node->this == tree->leaf_tail) {
	344	/* if there is no next node, this might be the new tail */
	345	tree->leaf_tail = new_node->this;
	346	mark_inode_dirty(tree->inode);
	347	}
	348
	349	hfs_bnode_dump(node);
	350	hfs_bnode_dump(new_node);
	351	hfs_bnode_put(node);
	352
	353	return new_node;
	354	}
	355
	356	static int hfs_brec_update_parent(struct hfs_find_data *fd)
	357	{
	358	struct hfs_btree *tree;
	359	struct hfs_bnode node, new_node, *parent;
	360	int newkeylen, diff;
	361	int rec, rec_off, end_rec_off;
	362	int start_off, end_off;
	363
	364	tree = fd->tree;
	365	node = fd->bnode;
	366	new_node = NULL;
	367	if (!node->parent)
	368	return 0;
	369
	370	again:
	371	parent = hfs_bnode_find(tree, node->parent);
	372	if (IS_ERR(parent))
	373	return PTR_ERR(parent);
324ef39a	374	__hfs_brec_find(parent, fd, hfs_find_rec_by_key);
98cf21c6 SA	375	if (fd->record < 0)
98cf21c6 SA	376	return -ENOENT;
1da177e4 LT	377	hfs_bnode_dump(parent);
	378	rec = fd->record;
	379
	380	/* size difference between old and new key */
324ef39a VD	381	if ((tree->attributes & HFS_TREE_VARIDXKEYS) \|\|
324ef39a VD	382	(tree->cnid == HFSPLUS_ATTR_CNID))
1da177e4 LT	383	newkeylen = hfs_bnode_read_u16(node, 14) + 2;
	384	else
	385	fd->keylength = newkeylen = tree->max_key_len + 2;
c2b3e1f7	386	hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
2753cc28	387	rec, fd->keylength, newkeylen);
1da177e4 LT	388
	389	rec_off = tree->node_size - (rec + 2) * 2;
	390	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
	391	diff = newkeylen - fd->keylength;
	392	if (!diff)
	393	goto skip;
	394	if (diff > 0) {
	395	end_off = hfs_bnode_read_u16(parent, end_rec_off);
	396	if (end_rec_off - end_off < diff) {
	397
c2b3e1f7	398	hfs_dbg(BNODE_MOD, "splitting index node\n");
1da177e4 LT	399	fd->bnode = parent;
	400	new_node = hfs_bnode_split(fd);
	401	if (IS_ERR(new_node))
	402	return PTR_ERR(new_node);
	403	parent = fd->bnode;
	404	rec = fd->record;
	405	rec_off = tree->node_size - (rec + 2) * 2;
2753cc28 AS	406	end_rec_off = tree->node_size -
2753cc28 AS	407	(parent->num_recs + 1) * 2;
1da177e4 LT	408	}
	409	}
	410
	411	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
	412	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
	413	start_off -= 4; /* move previous cnid too */
	414
	415	while (rec_off > end_rec_off) {
	416	rec_off -= 2;
	417	end_off = hfs_bnode_read_u16(parent, rec_off);
	418	hfs_bnode_write_u16(parent, rec_off, end_off + diff);
	419	}
	420	hfs_bnode_move(parent, start_off + diff, start_off,
	421	end_off - start_off);
	422	skip:
	423	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
	424	hfs_bnode_dump(parent);
	425
	426	hfs_bnode_put(node);
	427	node = parent;
	428
	429	if (new_node) {
	430	__be32 cnid;
	431
0a3021d4 EF	432	if (!new_node->parent) {
	433	hfs_btree_inc_height(tree);
	434	new_node->parent = tree->root;
	435	}
1da177e4 LT	436	fd->bnode = hfs_bnode_find(tree, new_node->parent);
	437	/* create index key and entry */
	438	hfs_bnode_read_key(new_node, fd->search_key, 14);
	439	cnid = cpu_to_be32(new_node->this);
	440
324ef39a	441	__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);
1da177e4 LT	442	hfs_brec_insert(fd, &cnid, sizeof(cnid));
	443	hfs_bnode_put(fd->bnode);
	444	hfs_bnode_put(new_node);
	445
	446	if (!rec) {
	447	if (new_node == node)
	448	goto out;
	449	/* restore search_key */
	450	hfs_bnode_read_key(node, fd->search_key, 14);
	451	}
19a9d0f1	452	new_node = NULL;
1da177e4 LT	453	}
	454
	455	if (!rec && node->parent)
	456	goto again;
	457	out:
	458	fd->bnode = node;
	459	return 0;
	460	}
	461
	462	static int hfs_btree_inc_height(struct hfs_btree *tree)
	463	{
	464	struct hfs_bnode node, new_node;
	465	struct hfs_bnode_desc node_desc;
	466	int key_size, rec;
	467	__be32 cnid;
	468
	469	node = NULL;
	470	if (tree->root) {
	471	node = hfs_bnode_find(tree, tree->root);
	472	if (IS_ERR(node))
	473	return PTR_ERR(node);
	474	}
	475	new_node = hfs_bmap_alloc(tree);
	476	if (IS_ERR(new_node)) {
	477	hfs_bnode_put(node);
	478	return PTR_ERR(new_node);
	479	}
	480
	481	tree->root = new_node->this;
	482	if (!tree->depth) {
	483	tree->leaf_head = tree->leaf_tail = new_node->this;
	484	new_node->type = HFS_NODE_LEAF;
	485	new_node->num_recs = 0;
	486	} else {
	487	new_node->type = HFS_NODE_INDEX;
	488	new_node->num_recs = 1;
	489	}
	490	new_node->parent = 0;
	491	new_node->next = 0;
	492	new_node->prev = 0;
	493	new_node->height = ++tree->depth;
	494
	495	node_desc.next = cpu_to_be32(new_node->next);
	496	node_desc.prev = cpu_to_be32(new_node->prev);
	497	node_desc.type = new_node->type;
	498	node_desc.height = new_node->height;
	499	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	500	node_desc.reserved = 0;
	501	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
	502
	503	rec = tree->node_size - 2;
	504	hfs_bnode_write_u16(new_node, rec, 14);
	505
	506	if (node) {
	507	/* insert old root idx into new root */
	508	node->parent = tree->root;
	509	if (node->type == HFS_NODE_LEAF \|\|
324ef39a VD	510	tree->attributes & HFS_TREE_VARIDXKEYS \|\|
324ef39a VD	511	tree->cnid == HFSPLUS_ATTR_CNID)
1da177e4 LT	512	key_size = hfs_bnode_read_u16(node, 14) + 2;
	513	else
	514	key_size = tree->max_key_len + 2;
	515	hfs_bnode_copy(new_node, 14, node, 14, key_size);
	516
324ef39a VD	517	if (!(tree->attributes & HFS_TREE_VARIDXKEYS) &&
324ef39a VD	518	(tree->cnid != HFSPLUS_ATTR_CNID)) {
1da177e4 LT	519	key_size = tree->max_key_len + 2;
	520	hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
	521	}
	522	cnid = cpu_to_be32(node->this);
	523	hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
	524
	525	rec -= 2;
	526	hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
	527
	528	hfs_bnode_put(node);
	529	}
	530	hfs_bnode_put(new_node);
	531	mark_inode_dirty(tree->inode);
	532
	533	return 0;
	534	}