[mirror_ubuntu-artful-kernel.git] / fs / hfsplus / brec.c

/*
 *  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;

		retval = hfs_bnode_read_u16(node, recoff) + 2;
		if (retval > node->tree->max_key_len + 2) {
			printk(KERN_ERR "hfs: 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);
		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, *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);
	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;

	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_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) {

			dprint(DBG_BNODE_MOD, "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;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfsplus/brec.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer (flar@allandria.com)
	6	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	7	*
	8	* Handle individual btree records
	9	*/
	10
	11	#include "hfsplus_fs.h"
	12	#include "hfsplus_raw.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 *);
	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	retval = node->tree->max_key_len + 2;
	41	} else {
2753cc28 AS	42	recoff = hfs_bnode_read_u16(node,
2753cc28 AS	43	node->tree->node_size - (rec + 1) * 2);
1da177e4 LT	44	if (!recoff)
1da177e4 LT	45	return 0;
13571a69 CH	46
	47	retval = hfs_bnode_read_u16(node, recoff) + 2;
	48	if (retval > node->tree->max_key_len + 2) {
	49	printk(KERN_ERR "hfs: keylen %d too large\n",
	50	retval);
	51	retval = 0;
9250f925	52	}
1da177e4 LT	53	}
	54	return retval;
	55	}
	56
	57	int hfs_brec_insert(struct hfs_find_data fd, void entry, int entry_len)
	58	{
	59	struct hfs_btree *tree;
	60	struct hfs_bnode node, new_node;
	61	int size, key_len, rec;
	62	int data_off, end_off;
	63	int idx_rec_off, data_rec_off, end_rec_off;
	64	__be32 cnid;
	65
	66	tree = fd->tree;
	67	if (!fd->bnode) {
	68	if (!tree->root)
	69	hfs_btree_inc_height(tree);
	70	fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
	71	if (IS_ERR(fd->bnode))
	72	return PTR_ERR(fd->bnode);
	73	fd->record = -1;
	74	}
	75	new_node = NULL;
	76	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
	77	again:
	78	/* new record idx and complete record size */
	79	rec = fd->record + 1;
	80	size = key_len + entry_len;
	81
	82	node = fd->bnode;
	83	hfs_bnode_dump(node);
	84	/* get last offset */
	85	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
	86	end_off = hfs_bnode_read_u16(node, end_rec_off);
	87	end_rec_off -= 2;
2753cc28 AS	88	dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
2753cc28 AS	89	rec, size, end_off, end_rec_off);
1da177e4 LT	90	if (size > end_rec_off - end_off) {
	91	if (new_node)
	92	panic("not enough room!\n");
	93	new_node = hfs_bnode_split(fd);
	94	if (IS_ERR(new_node))
	95	return PTR_ERR(new_node);
	96	goto again;
	97	}
	98	if (node->type == HFS_NODE_LEAF) {
	99	tree->leaf_count++;
	100	mark_inode_dirty(tree->inode);
	101	}
	102	node->num_recs++;
	103	/* write new last offset */
2753cc28 AS	104	hfs_bnode_write_u16(node,
	105	offsetof(struct hfs_bnode_desc, num_recs),
	106	node->num_recs);
1da177e4 LT	107	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
	108	data_off = end_off;
	109	data_rec_off = end_rec_off + 2;
	110	idx_rec_off = tree->node_size - (rec + 1) * 2;
	111	if (idx_rec_off == data_rec_off)
	112	goto skip;
	113	/* move all following entries */
	114	do {
	115	data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
	116	hfs_bnode_write_u16(node, data_rec_off, data_off + size);
	117	data_rec_off += 2;
	118	} while (data_rec_off < idx_rec_off);
	119
	120	/* move data away */
	121	hfs_bnode_move(node, data_off + size, data_off,
	122	end_off - data_off);
	123
	124	skip:
	125	hfs_bnode_write(node, fd->search_key, data_off, key_len);
	126	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
	127	hfs_bnode_dump(node);
	128
	129	if (new_node) {
	130	/* update parent key if we inserted a key
	131	* at the start of the first node
	132	*/
	133	if (!rec && new_node != node)
	134	hfs_brec_update_parent(fd);
	135
	136	hfs_bnode_put(fd->bnode);
	137	if (!new_node->parent) {
	138	hfs_btree_inc_height(tree);
	139	new_node->parent = tree->root;
	140	}
	141	fd->bnode = hfs_bnode_find(tree, new_node->parent);
	142
	143	/* create index data entry */
	144	cnid = cpu_to_be32(new_node->this);
	145	entry = &cnid;
	146	entry_len = sizeof(cnid);
	147
	148	/* get index key */
	149	hfs_bnode_read_key(new_node, fd->search_key, 14);
	150	__hfs_brec_find(fd->bnode, fd);
	151
	152	hfs_bnode_put(new_node);
	153	new_node = NULL;
	154
	155	if (tree->attributes & HFS_TREE_VARIDXKEYS)
	156	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
	157	else {
2753cc28 AS	158	fd->search_key->key_len =
2753cc28 AS	159	cpu_to_be16(tree->max_key_len);
1da177e4 LT	160	key_len = tree->max_key_len + 2;
	161	}
	162	goto again;
	163	}
	164
	165	if (!rec)
	166	hfs_brec_update_parent(fd);
	167
	168	return 0;
	169	}
	170
	171	int hfs_brec_remove(struct hfs_find_data *fd)
	172	{
	173	struct hfs_btree *tree;
	174	struct hfs_bnode node, parent;
	175	int end_off, rec_off, data_off, size;
	176
	177	tree = fd->tree;
	178	node = fd->bnode;
	179	again:
	180	rec_off = tree->node_size - (fd->record + 2) * 2;
	181	end_off = tree->node_size - (node->num_recs + 1) * 2;
	182
	183	if (node->type == HFS_NODE_LEAF) {
	184	tree->leaf_count--;
	185	mark_inode_dirty(tree->inode);
	186	}
	187	hfs_bnode_dump(node);
2753cc28 AS	188	dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n",
2753cc28 AS	189	fd->record, fd->keylength + fd->entrylength);
1da177e4 LT	190	if (!--node->num_recs) {
	191	hfs_bnode_unlink(node);
	192	if (!node->parent)
	193	return 0;
	194	parent = hfs_bnode_find(tree, node->parent);
	195	if (IS_ERR(parent))
	196	return PTR_ERR(parent);
	197	hfs_bnode_put(node);
	198	node = fd->bnode = parent;
	199
	200	__hfs_brec_find(node, fd);
	201	goto again;
	202	}
2753cc28 AS	203	hfs_bnode_write_u16(node,
	204	offsetof(struct hfs_bnode_desc, num_recs),
	205	node->num_recs);
1da177e4 LT	206
	207	if (rec_off == end_off)
	208	goto skip;
	209	size = fd->keylength + fd->entrylength;
	210
	211	do {
	212	data_off = hfs_bnode_read_u16(node, rec_off);
	213	hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
	214	rec_off -= 2;
	215	} while (rec_off >= end_off);
	216
	217	/* fill hole */
	218	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
	219	data_off - fd->keyoffset - size);
	220	skip:
	221	hfs_bnode_dump(node);
	222	if (!fd->record)
	223	hfs_brec_update_parent(fd);
	224	return 0;
	225	}
	226
	227	static struct hfs_bnode hfs_bnode_split(struct hfs_find_data fd)
	228	{
	229	struct hfs_btree *tree;
b6b41424	230	struct hfs_bnode node, new_node, *next_node;
1da177e4 LT	231	struct hfs_bnode_desc node_desc;
	232	int num_recs, new_rec_off, new_off, old_rec_off;
	233	int data_start, data_end, size;
	234
	235	tree = fd->tree;
	236	node = fd->bnode;
	237	new_node = hfs_bmap_alloc(tree);
	238	if (IS_ERR(new_node))
	239	return new_node;
	240	hfs_bnode_get(node);
	241	dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n",
	242	node->this, new_node->this, node->next);
	243	new_node->next = node->next;
	244	new_node->prev = node->this;
	245	new_node->parent = node->parent;
	246	new_node->type = node->type;
	247	new_node->height = node->height;
	248
b6b41424 AV	249	if (node->next)
	250	next_node = hfs_bnode_find(tree, node->next);
	251	else
	252	next_node = NULL;
	253
	254	if (IS_ERR(next_node)) {
	255	hfs_bnode_put(node);
	256	hfs_bnode_put(new_node);
	257	return next_node;
	258	}
	259
1da177e4 LT	260	size = tree->node_size / 2 - node->num_recs * 2 - 14;
	261	old_rec_off = tree->node_size - 4;
	262	num_recs = 1;
	263	for (;;) {
	264	data_start = hfs_bnode_read_u16(node, old_rec_off);
	265	if (data_start > size)
	266	break;
	267	old_rec_off -= 2;
	268	if (++num_recs < node->num_recs)
	269	continue;
	270	/* panic? */
	271	hfs_bnode_put(node);
	272	hfs_bnode_put(new_node);
b6b41424 AV	273	if (next_node)
b6b41424 AV	274	hfs_bnode_put(next_node);
1da177e4 LT	275	return ERR_PTR(-ENOSPC);
	276	}
	277
	278	if (fd->record + 1 < num_recs) {
	279	/* new record is in the lower half,
	280	* so leave some more space there
	281	*/
	282	old_rec_off += 2;
	283	num_recs--;
	284	data_start = hfs_bnode_read_u16(node, old_rec_off);
	285	} else {
	286	hfs_bnode_put(node);
	287	hfs_bnode_get(new_node);
	288	fd->bnode = new_node;
	289	fd->record -= num_recs;
	290	fd->keyoffset -= data_start - 14;
	291	fd->entryoffset -= data_start - 14;
	292	}
	293	new_node->num_recs = node->num_recs - num_recs;
	294	node->num_recs = num_recs;
	295
	296	new_rec_off = tree->node_size - 2;
	297	new_off = 14;
	298	size = data_start - new_off;
	299	num_recs = new_node->num_recs;
	300	data_end = data_start;
	301	while (num_recs) {
	302	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	303	old_rec_off -= 2;
	304	new_rec_off -= 2;
	305	data_end = hfs_bnode_read_u16(node, old_rec_off);
	306	new_off = data_end - size;
	307	num_recs--;
	308	}
	309	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	310	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
	311
	312	/* update new bnode header */
	313	node_desc.next = cpu_to_be32(new_node->next);
	314	node_desc.prev = cpu_to_be32(new_node->prev);
	315	node_desc.type = new_node->type;
	316	node_desc.height = new_node->height;
	317	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	318	node_desc.reserved = 0;
	319	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
	320
	321	/* update previous bnode header */
	322	node->next = new_node->this;
	323	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
	324	node_desc.next = cpu_to_be32(node->next);
	325	node_desc.num_recs = cpu_to_be16(node->num_recs);
	326	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
	327
	328	/* update next bnode header */
b6b41424	329	if (next_node) {
1da177e4 LT	330	next_node->prev = new_node->this;
	331	hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
	332	node_desc.prev = cpu_to_be32(next_node->prev);
	333	hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
	334	hfs_bnode_put(next_node);
	335	} else if (node->this == tree->leaf_tail) {
	336	/* if there is no next node, this might be the new tail */
	337	tree->leaf_tail = new_node->this;
	338	mark_inode_dirty(tree->inode);
	339	}
	340
	341	hfs_bnode_dump(node);
	342	hfs_bnode_dump(new_node);
	343	hfs_bnode_put(node);
	344
	345	return new_node;
	346	}
	347
	348	static int hfs_brec_update_parent(struct hfs_find_data *fd)
	349	{
	350	struct hfs_btree *tree;
	351	struct hfs_bnode node, new_node, *parent;
	352	int newkeylen, diff;
	353	int rec, rec_off, end_rec_off;
	354	int start_off, end_off;
	355
	356	tree = fd->tree;
	357	node = fd->bnode;
	358	new_node = NULL;
	359	if (!node->parent)
	360	return 0;
	361
	362	again:
	363	parent = hfs_bnode_find(tree, node->parent);
	364	if (IS_ERR(parent))
	365	return PTR_ERR(parent);
	366	__hfs_brec_find(parent, fd);
	367	hfs_bnode_dump(parent);
	368	rec = fd->record;
	369
	370	/* size difference between old and new key */
	371	if (tree->attributes & HFS_TREE_VARIDXKEYS)
	372	newkeylen = hfs_bnode_read_u16(node, 14) + 2;
	373	else
	374	fd->keylength = newkeylen = tree->max_key_len + 2;
2753cc28 AS	375	dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n",
2753cc28 AS	376	rec, fd->keylength, newkeylen);
1da177e4 LT	377
	378	rec_off = tree->node_size - (rec + 2) * 2;
	379	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
	380	diff = newkeylen - fd->keylength;
	381	if (!diff)
	382	goto skip;
	383	if (diff > 0) {
	384	end_off = hfs_bnode_read_u16(parent, end_rec_off);
	385	if (end_rec_off - end_off < diff) {
	386
6d1bbfc4	387	dprint(DBG_BNODE_MOD, "hfs: splitting index node.\n");
1da177e4 LT	388	fd->bnode = parent;
	389	new_node = hfs_bnode_split(fd);
	390	if (IS_ERR(new_node))
	391	return PTR_ERR(new_node);
	392	parent = fd->bnode;
	393	rec = fd->record;
	394	rec_off = tree->node_size - (rec + 2) * 2;
2753cc28 AS	395	end_rec_off = tree->node_size -
2753cc28 AS	396	(parent->num_recs + 1) * 2;
1da177e4 LT	397	}
	398	}
	399
	400	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
	401	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
	402	start_off -= 4; /* move previous cnid too */
	403
	404	while (rec_off > end_rec_off) {
	405	rec_off -= 2;
	406	end_off = hfs_bnode_read_u16(parent, rec_off);
	407	hfs_bnode_write_u16(parent, rec_off, end_off + diff);
	408	}
	409	hfs_bnode_move(parent, start_off + diff, start_off,
	410	end_off - start_off);
	411	skip:
	412	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
	413	hfs_bnode_dump(parent);
	414
	415	hfs_bnode_put(node);
	416	node = parent;
	417
	418	if (new_node) {
	419	__be32 cnid;
	420
	421	fd->bnode = hfs_bnode_find(tree, new_node->parent);
	422	/* create index key and entry */
	423	hfs_bnode_read_key(new_node, fd->search_key, 14);
	424	cnid = cpu_to_be32(new_node->this);
	425
	426	__hfs_brec_find(fd->bnode, fd);
	427	hfs_brec_insert(fd, &cnid, sizeof(cnid));
	428	hfs_bnode_put(fd->bnode);
	429	hfs_bnode_put(new_node);
	430
	431	if (!rec) {
	432	if (new_node == node)
	433	goto out;
	434	/* restore search_key */
	435	hfs_bnode_read_key(node, fd->search_key, 14);
	436	}
	437	}
	438
	439	if (!rec && node->parent)
	440	goto again;
	441	out:
	442	fd->bnode = node;
	443	return 0;
	444	}
	445
	446	static int hfs_btree_inc_height(struct hfs_btree *tree)
	447	{
	448	struct hfs_bnode node, new_node;
	449	struct hfs_bnode_desc node_desc;
	450	int key_size, rec;
	451	__be32 cnid;
	452
	453	node = NULL;
	454	if (tree->root) {
	455	node = hfs_bnode_find(tree, tree->root);
	456	if (IS_ERR(node))
	457	return PTR_ERR(node);
	458	}
	459	new_node = hfs_bmap_alloc(tree);
	460	if (IS_ERR(new_node)) {
461	hfs_bnode_put(node);
462	return PTR_ERR(new_node);
463	}
464
465	tree->root = new_node->this;
466	if (!tree->depth) {
467	tree->leaf_head = tree->leaf_tail = new_node->this;
468	new_node->type = HFS_NODE_LEAF;
469	new_node->num_recs = 0;
470	} else {
471	new_node->type = HFS_NODE_INDEX;
472	new_node->num_recs = 1;
473	}
474	new_node->parent = 0;
475	new_node->next = 0;
476	new_node->prev = 0;
477	new_node->height = ++tree->depth;
478
479	node_desc.next = cpu_to_be32(new_node->next);
480	node_desc.prev = cpu_to_be32(new_node->prev);
481	node_desc.type = new_node->type;
482	node_desc.height = new_node->height;
483	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
484	node_desc.reserved = 0;
485	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
486
487	rec = tree->node_size - 2;
488	hfs_bnode_write_u16(new_node, rec, 14);
489
490	if (node) {
491	/* insert old root idx into new root */
492	node->parent = tree->root;
493	if (node->type == HFS_NODE_LEAF \|\|
494	tree->attributes & HFS_TREE_VARIDXKEYS)
495	key_size = hfs_bnode_read_u16(node, 14) + 2;
496	else
497	key_size = tree->max_key_len + 2;
498	hfs_bnode_copy(new_node, 14, node, 14, key_size);
499
500	if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
501	key_size = tree->max_key_len + 2;
502	hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
503	}
504	cnid = cpu_to_be32(node->this);
505	hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
506
507	rec -= 2;
508	hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
509
510	hfs_bnode_put(node);
511	}
512	hfs_bnode_put(new_node);
513	mark_inode_dirty(tree->inode);
514
515	return 0;
516	}