[linux.git] / fs / hfs / btree.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hfs/btree.c
 *
 * Copyright (C) 2001
 * Brad Boyer ([email protected])
 * (C) 2003 Ardis Technologies <[email protected]>
 *
 * Handle opening/closing btree
 */

#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/log2.h>

#include "btree.h"

/* Get a reference to a B*Tree and do some initial checks */
struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
{
	struct hfs_btree *tree;
	struct hfs_btree_header_rec *head;
	struct address_space *mapping;
	struct page *page;
	unsigned int size;

	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
	if (!tree)
		return NULL;

	mutex_init(&tree->tree_lock);
	spin_lock_init(&tree->hash_lock);
	/* Set the correct compare function */
	tree->sb = sb;
	tree->cnid = id;
	tree->keycmp = keycmp;

	tree->inode = iget_locked(sb, id);
	if (!tree->inode)
		goto free_tree;
	BUG_ON(!(tree->inode->i_state & I_NEW));
	{
	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
	HFS_I(tree->inode)->flags = 0;
	mutex_init(&HFS_I(tree->inode)->extents_lock);
	switch (id) {
	case HFS_EXT_CNID:
		hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
				    mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
		if (HFS_I(tree->inode)->alloc_blocks >
					HFS_I(tree->inode)->first_blocks) {
			pr_err("invalid btree extent records\n");
			unlock_new_inode(tree->inode);
			goto free_inode;
		}

		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
		break;
	case HFS_CAT_CNID:
		hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
				    mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));

		if (!HFS_I(tree->inode)->first_blocks) {
			pr_err("invalid btree extent records (0 size)\n");
			unlock_new_inode(tree->inode);
			goto free_inode;
		}

		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
		break;
	default:
		BUG();
	}
	}
	unlock_new_inode(tree->inode);

	mapping = tree->inode->i_mapping;
	page = read_mapping_page(mapping, 0, NULL);
	if (IS_ERR(page))
		goto free_inode;

	/* Load the header */
	head = (struct hfs_btree_header_rec *)(kmap_local_page(page) +
					       sizeof(struct hfs_bnode_desc));
	tree->root = be32_to_cpu(head->root);
	tree->leaf_count = be32_to_cpu(head->leaf_count);
	tree->leaf_head = be32_to_cpu(head->leaf_head);
	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	tree->node_count = be32_to_cpu(head->node_count);
	tree->free_nodes = be32_to_cpu(head->free_nodes);
	tree->attributes = be32_to_cpu(head->attributes);
	tree->node_size = be16_to_cpu(head->node_size);
	tree->max_key_len = be16_to_cpu(head->max_key_len);
	tree->depth = be16_to_cpu(head->depth);

	size = tree->node_size;
	if (!is_power_of_2(size))
		goto fail_page;
	if (!tree->node_count)
		goto fail_page;
	switch (id) {
	case HFS_EXT_CNID:
		if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
			pr_err("invalid extent max_key_len %d\n",
			       tree->max_key_len);
			goto fail_page;
		}
		break;
	case HFS_CAT_CNID:
		if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
			pr_err("invalid catalog max_key_len %d\n",
			       tree->max_key_len);
			goto fail_page;
		}
		break;
	default:
		BUG();
	}

	tree->node_size_shift = ffs(size) - 1;
	tree->pages_per_bnode = (tree->node_size + PAGE_SIZE - 1) >> PAGE_SHIFT;

	kunmap_local(head);
	put_page(page);
	return tree;

fail_page:
	kunmap_local(head);
	put_page(page);
free_inode:
	tree->inode->i_mapping->a_ops = &hfs_aops;
	iput(tree->inode);
free_tree:
	kfree(tree);
	return NULL;
}

/* Release resources used by a btree */
void hfs_btree_close(struct hfs_btree *tree)
{
	struct hfs_bnode *node;
	int i;

	if (!tree)
		return;

	for (i = 0; i < NODE_HASH_SIZE; i++) {
		while ((node = tree->node_hash[i])) {
			tree->node_hash[i] = node->next_hash;
			if (atomic_read(&node->refcnt))
				pr_err("node %d:%d still has %d user(s)!\n",
				       node->tree->cnid, node->this,
				       atomic_read(&node->refcnt));
			hfs_bnode_free(node);
			tree->node_hash_cnt--;
		}
	}
	iput(tree->inode);
	kfree(tree);
}

void hfs_btree_write(struct hfs_btree *tree)
{
	struct hfs_btree_header_rec *head;
	struct hfs_bnode *node;
	struct page *page;

	node = hfs_bnode_find(tree, 0);
	if (IS_ERR(node))
		/* panic? */
		return;
	/* Load the header */
	page = node->page[0];
	head = (struct hfs_btree_header_rec *)(kmap_local_page(page) +
					       sizeof(struct hfs_bnode_desc));

	head->root = cpu_to_be32(tree->root);
	head->leaf_count = cpu_to_be32(tree->leaf_count);
	head->leaf_head = cpu_to_be32(tree->leaf_head);
	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	head->node_count = cpu_to_be32(tree->node_count);
	head->free_nodes = cpu_to_be32(tree->free_nodes);
	head->attributes = cpu_to_be32(tree->attributes);
	head->depth = cpu_to_be16(tree->depth);

	kunmap_local(head);
	set_page_dirty(page);
	hfs_bnode_put(node);
}

static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
{
	struct hfs_btree *tree = prev->tree;
	struct hfs_bnode *node;
	struct hfs_bnode_desc desc;
	__be32 cnid;

	node = hfs_bnode_create(tree, idx);
	if (IS_ERR(node))
		return node;

	if (!tree->free_nodes)
		panic("FIXME!!!");
	tree->free_nodes--;
	prev->next = idx;
	cnid = cpu_to_be32(idx);
	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);

	node->type = HFS_NODE_MAP;
	node->num_recs = 1;
	hfs_bnode_clear(node, 0, tree->node_size);
	desc.next = 0;
	desc.prev = 0;
	desc.type = HFS_NODE_MAP;
	desc.height = 0;
	desc.num_recs = cpu_to_be16(1);
	desc.reserved = 0;
	hfs_bnode_write(node, &desc, 0, sizeof(desc));
	hfs_bnode_write_u16(node, 14, 0x8000);
	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);

	return node;
}

/* Make sure @tree has enough space for the @rsvd_nodes */
int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes)
{
	struct inode *inode = tree->inode;
	u32 count;
	int res;

	while (tree->free_nodes < rsvd_nodes) {
		res = hfs_extend_file(inode);
		if (res)
			return res;
		HFS_I(inode)->phys_size = inode->i_size =
				(loff_t)HFS_I(inode)->alloc_blocks *
				HFS_SB(tree->sb)->alloc_blksz;
		HFS_I(inode)->fs_blocks = inode->i_size >>
					  tree->sb->s_blocksize_bits;
		inode_set_bytes(inode, inode->i_size);
		count = inode->i_size >> tree->node_size_shift;
		tree->free_nodes += count - tree->node_count;
		tree->node_count = count;
	}
	return 0;
}

struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
{
	struct hfs_bnode *node, *next_node;
	struct page **pagep;
	u32 nidx, idx;
	unsigned off;
	u16 off16;
	u16 len;
	u8 *data, byte, m;
	int i, res;

	res = hfs_bmap_reserve(tree, 1);
	if (res)
		return ERR_PTR(res);

	nidx = 0;
	node = hfs_bnode_find(tree, nidx);
	if (IS_ERR(node))
		return node;
	len = hfs_brec_lenoff(node, 2, &off16);
	off = off16;

	off += node->page_offset;
	pagep = node->page + (off >> PAGE_SHIFT);
	data = kmap_local_page(*pagep);
	off &= ~PAGE_MASK;
	idx = 0;

	for (;;) {
		while (len) {
			byte = data[off];
			if (byte != 0xff) {
				for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
					if (!(byte & m)) {
						idx += i;
						data[off] |= m;
						set_page_dirty(*pagep);
						kunmap_local(data);
						tree->free_nodes--;
						mark_inode_dirty(tree->inode);
						hfs_bnode_put(node);
						return hfs_bnode_create(tree, idx);
					}
				}
			}
			if (++off >= PAGE_SIZE) {
				kunmap_local(data);
				data = kmap_local_page(*++pagep);
				off = 0;
			}
			idx += 8;
			len--;
		}
		kunmap_local(data);
		nidx = node->next;
		if (!nidx) {
			printk(KERN_DEBUG "create new bmap node...\n");
			next_node = hfs_bmap_new_bmap(node, idx);
		} else
			next_node = hfs_bnode_find(tree, nidx);
		hfs_bnode_put(node);
		if (IS_ERR(next_node))
			return next_node;
		node = next_node;

		len = hfs_brec_lenoff(node, 0, &off16);
		off = off16;
		off += node->page_offset;
		pagep = node->page + (off >> PAGE_SHIFT);
		data = kmap_local_page(*pagep);
		off &= ~PAGE_MASK;
	}
}

void hfs_bmap_free(struct hfs_bnode *node)
{
	struct hfs_btree *tree;
	struct page *page;
	u16 off, len;
	u32 nidx;
	u8 *data, byte, m;

	hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this);
	tree = node->tree;
	nidx = node->this;
	node = hfs_bnode_find(tree, 0);
	if (IS_ERR(node))
		return;
	len = hfs_brec_lenoff(node, 2, &off);
	while (nidx >= len * 8) {
		u32 i;

		nidx -= len * 8;
		i = node->next;
		if (!i) {
			/* panic */;
			pr_crit("unable to free bnode %u. bmap not found!\n",
				node->this);
			hfs_bnode_put(node);
			return;
		}
		hfs_bnode_put(node);
		node = hfs_bnode_find(tree, i);
		if (IS_ERR(node))
			return;
		if (node->type != HFS_NODE_MAP) {
			/* panic */;
			pr_crit("invalid bmap found! (%u,%d)\n",
				node->this, node->type);
			hfs_bnode_put(node);
			return;
		}
		len = hfs_brec_lenoff(node, 0, &off);
	}
	off += node->page_offset + nidx / 8;
	page = node->page[off >> PAGE_SHIFT];
	data = kmap_local_page(page);
	off &= ~PAGE_MASK;
	m = 1 << (~nidx & 7);
	byte = data[off];
	if (!(byte & m)) {
		pr_crit("trying to free free bnode %u(%d)\n",
			node->this, node->type);
		kunmap_local(data);
		hfs_bnode_put(node);
		return;
	}
	data[off] = byte & ~m;
	set_page_dirty(page);
	kunmap_local(data);
	hfs_bnode_put(node);
	tree->free_nodes++;
	mark_inode_dirty(tree->inode);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/hfs/btree.c
	4	*
	5	* Copyright (C) 2001
	6	* Brad Boyer ([email protected])
	7	* (C) 2003 Ardis Technologies <[email protected]>
	8	*
	9	* Handle opening/closing btree
	10	*/
	11
	12	#include <linux/pagemap.h>
5a0e3ad6	13	#include <linux/slab.h>
e1b5c1d3	14	#include <linux/log2.h>
1da177e4 LT	15
	16	#include "btree.h"
	17
	18	/* Get a reference to a BTree and do some initial checks /
	19	struct hfs_btree hfs_btree_open(struct super_block sb, u32 id, btree_keycmp keycmp)
	20	{
	21	struct hfs_btree *tree;
	22	struct hfs_btree_header_rec *head;
	23	struct address_space *mapping;
	24	struct page *page;
	25	unsigned int size;
	26
f8314dc6	27	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
1da177e4 LT	28	if (!tree)
1da177e4 LT	29	return NULL;
1da177e4	30
4a941035	31	mutex_init(&tree->tree_lock);
1da177e4 LT	32	spin_lock_init(&tree->hash_lock);
	33	/* Set the correct compare function */
	34	tree->sb = sb;
	35	tree->cnid = id;
	36	tree->keycmp = keycmp;
	37
	38	tree->inode = iget_locked(sb, id);
	39	if (!tree->inode)
	40	goto free_tree;
4d4ef9ab	41	BUG_ON(!(tree->inode->i_state & I_NEW));
1da177e4 LT	42	{
	43	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
	44	HFS_I(tree->inode)->flags = 0;
39f8d472	45	mutex_init(&HFS_I(tree->inode)->extents_lock);
1da177e4 LT	46	switch (id) {
	47	case HFS_EXT_CNID:
	48	hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
	49	mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
434a964d PL	50	if (HFS_I(tree->inode)->alloc_blocks >
434a964d PL	51	HFS_I(tree->inode)->first_blocks) {
d6142673	52	pr_err("invalid btree extent records\n");
434a964d PL	53	unlock_new_inode(tree->inode);
	54	goto free_inode;
	55	}
	56
1da177e4 LT	57	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	58	break;
	59	case HFS_CAT_CNID:
	60	hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
	61	mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
434a964d PL	62
434a964d PL	63	if (!HFS_I(tree->inode)->first_blocks) {
d6142673	64	pr_err("invalid btree extent records (0 size)\n");
434a964d PL	65	unlock_new_inode(tree->inode);
	66	goto free_inode;
	67	}
	68
1da177e4 LT	69	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	70	break;
	71	default:
	72	BUG();
	73	}
	74	}
	75	unlock_new_inode(tree->inode);
	76
	77	mapping = tree->inode->i_mapping;
090d2b18	78	page = read_mapping_page(mapping, 0, NULL);
1da177e4	79	if (IS_ERR(page))
46a39c1c	80	goto free_inode;
1da177e4 LT	81
1da177e4 LT	82	/* Load the header */
21490eff FDF	83	head = (struct hfs_btree_header_rec *)(kmap_local_page(page) +
21490eff FDF	84	sizeof(struct hfs_bnode_desc));
1da177e4 LT	85	tree->root = be32_to_cpu(head->root);
	86	tree->leaf_count = be32_to_cpu(head->leaf_count);
	87	tree->leaf_head = be32_to_cpu(head->leaf_head);
	88	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	89	tree->node_count = be32_to_cpu(head->node_count);
	90	tree->free_nodes = be32_to_cpu(head->free_nodes);
	91	tree->attributes = be32_to_cpu(head->attributes);
	92	tree->node_size = be16_to_cpu(head->node_size);
	93	tree->max_key_len = be16_to_cpu(head->max_key_len);
	94	tree->depth = be16_to_cpu(head->depth);
	95
	96	size = tree->node_size;
e1b5c1d3	97	if (!is_power_of_2(size))
1da177e4 LT	98	goto fail_page;
	99	if (!tree->node_count)
	100	goto fail_page;
55581d01 ES	101	switch (id) {
	102	case HFS_EXT_CNID:
	103	if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
d6142673 JP	104	pr_err("invalid extent max_key_len %d\n",
d6142673 JP	105	tree->max_key_len);
55581d01 ES	106	goto fail_page;
	107	}
	108	break;
	109	case HFS_CAT_CNID:
	110	if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
d6142673 JP	111	pr_err("invalid catalog max_key_len %d\n",
d6142673 JP	112	tree->max_key_len);
55581d01 ES	113	goto fail_page;
	114	}
	115	break;
	116	default:
	117	BUG();
cf059462 ES	118	}
cf059462 ES	119
1da177e4	120	tree->node_size_shift = ffs(size) - 1;
09cbfeaf	121	tree->pages_per_bnode = (tree->node_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1da177e4	122
21490eff	123	kunmap_local(head);
09cbfeaf	124	put_page(page);
1da177e4 LT	125	return tree;
1da177e4 LT	126
46a39c1c	127	fail_page:
21490eff	128	kunmap_local(head);
09cbfeaf	129	put_page(page);
46a39c1c	130	free_inode:
cf059462	131	tree->inode->i_mapping->a_ops = &hfs_aops;
1da177e4	132	iput(tree->inode);
46a39c1c	133	free_tree:
1da177e4 LT	134	kfree(tree);
	135	return NULL;
	136	}
	137
	138	/* Release resources used by a btree */
	139	void hfs_btree_close(struct hfs_btree *tree)
	140	{
	141	struct hfs_bnode *node;
	142	int i;
	143
	144	if (!tree)
	145	return;
	146
	147	for (i = 0; i < NODE_HASH_SIZE; i++) {
	148	while ((node = tree->node_hash[i])) {
	149	tree->node_hash[i] = node->next_hash;
	150	if (atomic_read(&node->refcnt))
d6142673 JP	151	pr_err("node %d:%d still has %d user(s)!\n",
	152	node->tree->cnid, node->this,
	153	atomic_read(&node->refcnt));
1da177e4 LT	154	hfs_bnode_free(node);
	155	tree->node_hash_cnt--;
	156	}
	157	}
	158	iput(tree->inode);
	159	kfree(tree);
	160	}
	161
	162	void hfs_btree_write(struct hfs_btree *tree)
	163	{
	164	struct hfs_btree_header_rec *head;
	165	struct hfs_bnode *node;
	166	struct page *page;
	167
	168	node = hfs_bnode_find(tree, 0);
	169	if (IS_ERR(node))
	170	/* panic? */
	171	return;
	172	/* Load the header */
	173	page = node->page[0];
21490eff FDF	174	head = (struct hfs_btree_header_rec *)(kmap_local_page(page) +
21490eff FDF	175	sizeof(struct hfs_bnode_desc));
1da177e4 LT	176
	177	head->root = cpu_to_be32(tree->root);
	178	head->leaf_count = cpu_to_be32(tree->leaf_count);
	179	head->leaf_head = cpu_to_be32(tree->leaf_head);
	180	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	181	head->node_count = cpu_to_be32(tree->node_count);
	182	head->free_nodes = cpu_to_be32(tree->free_nodes);
	183	head->attributes = cpu_to_be32(tree->attributes);
	184	head->depth = cpu_to_be16(tree->depth);
	185
21490eff	186	kunmap_local(head);
1da177e4 LT	187	set_page_dirty(page);
	188	hfs_bnode_put(node);
	189	}
	190
	191	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	192	{
	193	struct hfs_btree *tree = prev->tree;
	194	struct hfs_bnode *node;
	195	struct hfs_bnode_desc desc;
	196	__be32 cnid;
	197
	198	node = hfs_bnode_create(tree, idx);
	199	if (IS_ERR(node))
	200	return node;
	201
	202	if (!tree->free_nodes)
	203	panic("FIXME!!!");
	204	tree->free_nodes--;
	205	prev->next = idx;
	206	cnid = cpu_to_be32(idx);
	207	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	208
	209	node->type = HFS_NODE_MAP;
	210	node->num_recs = 1;
	211	hfs_bnode_clear(node, 0, tree->node_size);
	212	desc.next = 0;
	213	desc.prev = 0;
	214	desc.type = HFS_NODE_MAP;
	215	desc.height = 0;
	216	desc.num_recs = cpu_to_be16(1);
	217	desc.reserved = 0;
	218	hfs_bnode_write(node, &desc, 0, sizeof(desc));
	219	hfs_bnode_write_u16(node, 14, 0x8000);
	220	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
	221	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
	222
	223	return node;
	224	}
	225
54640c75 EF	226	/* Make sure @tree has enough space for the @rsvd_nodes */
54640c75 EF	227	int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes)
1da177e4	228	{
54640c75 EF	229	struct inode *inode = tree->inode;
	230	u32 count;
	231	int res;
1da177e4	232
54640c75	233	while (tree->free_nodes < rsvd_nodes) {
1da177e4 LT	234	res = hfs_extend_file(inode);
1da177e4 LT	235	if (res)
54640c75	236	return res;
1da177e4 LT	237	HFS_I(inode)->phys_size = inode->i_size =
	238	(loff_t)HFS_I(inode)->alloc_blocks *
	239	HFS_SB(tree->sb)->alloc_blksz;
	240	HFS_I(inode)->fs_blocks = inode->i_size >>
	241	tree->sb->s_blocksize_bits;
	242	inode_set_bytes(inode, inode->i_size);
	243	count = inode->i_size >> tree->node_size_shift;
54640c75	244	tree->free_nodes += count - tree->node_count;
1da177e4 LT	245	tree->node_count = count;
1da177e4 LT	246	}
54640c75 EF	247	return 0;
	248	}
	249
	250	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
	251	{
	252	struct hfs_bnode node, next_node;
	253	struct page **pagep;
	254	u32 nidx, idx;
	255	unsigned off;
	256	u16 off16;
	257	u16 len;
	258	u8 *data, byte, m;
	259	int i, res;
	260
	261	res = hfs_bmap_reserve(tree, 1);
	262	if (res)
	263	return ERR_PTR(res);
1da177e4 LT	264
	265	nidx = 0;
	266	node = hfs_bnode_find(tree, nidx);
	267	if (IS_ERR(node))
	268	return node;
3e5a5097 AM	269	len = hfs_brec_lenoff(node, 2, &off16);
3e5a5097 AM	270	off = off16;
1da177e4 LT	271
1da177e4 LT	272	off += node->page_offset;
09cbfeaf	273	pagep = node->page + (off >> PAGE_SHIFT);
21490eff	274	data = kmap_local_page(*pagep);
09cbfeaf	275	off &= ~PAGE_MASK;
1da177e4 LT	276	idx = 0;
	277
	278	for (;;) {
	279	while (len) {
	280	byte = data[off];
	281	if (byte != 0xff) {
	282	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
	283	if (!(byte & m)) {
	284	idx += i;
	285	data[off] \|= m;
	286	set_page_dirty(*pagep);
21490eff	287	kunmap_local(data);
1da177e4 LT	288	tree->free_nodes--;
	289	mark_inode_dirty(tree->inode);
	290	hfs_bnode_put(node);
	291	return hfs_bnode_create(tree, idx);
	292	}
	293	}
	294	}
09cbfeaf	295	if (++off >= PAGE_SIZE) {
21490eff FDF	296	kunmap_local(data);
21490eff FDF	297	data = kmap_local_page(*++pagep);
1da177e4 LT	298	off = 0;
	299	}
	300	idx += 8;
	301	len--;
	302	}
21490eff	303	kunmap_local(data);
1da177e4 LT	304	nidx = node->next;
1da177e4 LT	305	if (!nidx) {
d6142673	306	printk(KERN_DEBUG "create new bmap node...\n");
1da177e4 LT	307	next_node = hfs_bmap_new_bmap(node, idx);
	308	} else
	309	next_node = hfs_bnode_find(tree, nidx);
	310	hfs_bnode_put(node);
	311	if (IS_ERR(next_node))
	312	return next_node;
	313	node = next_node;
	314
3e5a5097 AM	315	len = hfs_brec_lenoff(node, 0, &off16);
3e5a5097 AM	316	off = off16;
1da177e4	317	off += node->page_offset;
09cbfeaf	318	pagep = node->page + (off >> PAGE_SHIFT);
21490eff	319	data = kmap_local_page(*pagep);
09cbfeaf	320	off &= ~PAGE_MASK;
1da177e4 LT	321	}
	322	}
	323
	324	void hfs_bmap_free(struct hfs_bnode *node)
	325	{
	326	struct hfs_btree *tree;
	327	struct page *page;
	328	u16 off, len;
	329	u32 nidx;
	330	u8 *data, byte, m;
	331
c2b3e1f7	332	hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this);
1da177e4 LT	333	tree = node->tree;
	334	nidx = node->this;
	335	node = hfs_bnode_find(tree, 0);
	336	if (IS_ERR(node))
	337	return;
	338	len = hfs_brec_lenoff(node, 2, &off);
	339	while (nidx >= len * 8) {
	340	u32 i;
	341
	342	nidx -= len * 8;
	343	i = node->next;
1da177e4 LT	344	if (!i) {
1da177e4 LT	345	/* panic */;
d6142673 JP	346	pr_crit("unable to free bnode %u. bmap not found!\n",
d6142673 JP	347	node->this);
ce96a407	348	hfs_bnode_put(node);
1da177e4 LT	349	return;
1da177e4 LT	350	}
ce96a407	351	hfs_bnode_put(node);
1da177e4 LT	352	node = hfs_bnode_find(tree, i);
	353	if (IS_ERR(node))
	354	return;
	355	if (node->type != HFS_NODE_MAP) {
	356	/* panic */;
d6142673 JP	357	pr_crit("invalid bmap found! (%u,%d)\n",
d6142673 JP	358	node->this, node->type);
1da177e4 LT	359	hfs_bnode_put(node);
	360	return;
	361	}
	362	len = hfs_brec_lenoff(node, 0, &off);
	363	}
	364	off += node->page_offset + nidx / 8;
09cbfeaf	365	page = node->page[off >> PAGE_SHIFT];
21490eff	366	data = kmap_local_page(page);
09cbfeaf	367	off &= ~PAGE_MASK;
1da177e4 LT	368	m = 1 << (~nidx & 7);
	369	byte = data[off];
	370	if (!(byte & m)) {
d6142673 JP	371	pr_crit("trying to free free bnode %u(%d)\n",
d6142673 JP	372	node->this, node->type);
21490eff	373	kunmap_local(data);
1da177e4 LT	374	hfs_bnode_put(node);
	375	return;
	376	}
	377	data[off] = byte & ~m;
	378	set_page_dirty(page);
21490eff	379	kunmap_local(data);
1da177e4 LT	380	hfs_bnode_put(node);
	381	tree->free_nodes++;
	382	mark_inode_dirty(tree->inode);
	383	}