[deliverable/linux.git] / fs / hfsplus / btree.c

/*
 *  linux/fs/hfsplus/btree.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Handle opening/closing btree
 */

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

#include "hfsplus_fs.h"
#include "hfsplus_raw.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)
{
	struct hfs_btree *tree;
	struct hfs_btree_header_rec *head;
	struct address_space *mapping;
	struct inode *inode;
	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);
	tree->sb = sb;
	tree->cnid = id;
	inode = hfsplus_iget(sb, id);
	if (IS_ERR(inode))
		goto free_tree;
	tree->inode = inode;

	if (!HFSPLUS_I(tree->inode)->first_blocks) {
		printk(KERN_ERR
		       "hfs: invalid btree extent records (0 size).\n");
		goto free_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(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);

	/* Verify the tree and set the correct compare function */
	switch (id) {
	case HFSPLUS_EXT_CNID:
		if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
			printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
				tree->max_key_len);
			goto fail_page;
		}
		if (tree->attributes & HFS_TREE_VARIDXKEYS) {
			printk(KERN_ERR "hfs: invalid extent btree flag\n");
			goto fail_page;
		}

		tree->keycmp = hfsplus_ext_cmp_key;
		break;
	case HFSPLUS_CAT_CNID:
		if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
			printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
				tree->max_key_len);
			goto fail_page;
		}
		if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
			printk(KERN_ERR "hfs: invalid catalog btree flag\n");
			goto fail_page;
		}

		if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
		    (head->key_type == HFSPLUS_KEY_BINARY))
			tree->keycmp = hfsplus_cat_bin_cmp_key;
		else {
			tree->keycmp = hfsplus_cat_case_cmp_key;
			set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
		}
		break;
	default:
		printk(KERN_ERR "hfs: unknown B*Tree requested\n");
		goto fail_page;
	}

	if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
		printk(KERN_ERR "hfs: invalid btree flag\n");
		goto fail_page;
	}

	size = tree->node_size;
	if (!is_power_of_2(size))
		goto fail_page;
	if (!tree->node_count)
		goto fail_page;

	tree->node_size_shift = ffs(size) - 1;

	tree->pages_per_bnode =
		(tree->node_size + PAGE_CACHE_SIZE - 1) >>
		PAGE_CACHE_SHIFT;

	kunmap(page);
	page_cache_release(page);
	return tree;

 fail_page:
	page_cache_release(page);
 free_inode:
	tree->inode->i_mapping->a_ops = &hfsplus_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))
				printk(KERN_CRIT "hfs: 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);
}

int 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 -EIO;
	/* Load the header */
	page = node->page[0];
	head = (struct hfs_btree_header_rec *)(kmap(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(page);
	set_page_dirty(page);
	hfs_bnode_put(node);
	return 0;
}

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;

	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;
}

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;

	while (!tree->free_nodes) {
		struct inode *inode = tree->inode;
		struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
		u32 count;
		int res;

		res = hfsplus_file_extend(inode);
		if (res)
			return ERR_PTR(res);
		hip->phys_size = inode->i_size =
			(loff_t)hip->alloc_blocks <<
				HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
		hip->fs_blocks =
			hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
		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;
	}

	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_CACHE_SHIFT);
	data = kmap(*pagep);
	off &= ~PAGE_CACHE_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(*pagep);
						tree->free_nodes--;
						mark_inode_dirty(tree->inode);
						hfs_bnode_put(node);
						return hfs_bnode_create(tree,
							idx);
					}
				}
			}
			if (++off >= PAGE_CACHE_SIZE) {
				kunmap(*pagep);
				data = kmap(*++pagep);
				off = 0;
			}
			idx += 8;
			len--;
		}
		kunmap(*pagep);
		nidx = node->next;
		if (!nidx) {
			dprint(DBG_BNODE_MOD, "hfs: 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_CACHE_SHIFT);
		data = kmap(*pagep);
		off &= ~PAGE_CACHE_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;

	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
	BUG_ON(!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;
		hfs_bnode_put(node);
		if (!i) {
			/* panic */;
			printk(KERN_CRIT "hfs: unable to free bnode %u. "
					"bmap not found!\n",
				node->this);
			return;
		}
		node = hfs_bnode_find(tree, i);
		if (IS_ERR(node))
			return;
		if (node->type != HFS_NODE_MAP) {
			/* panic */;
			printk(KERN_CRIT "hfs: 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_CACHE_SHIFT];
	data = kmap(page);
	off &= ~PAGE_CACHE_MASK;
	m = 1 << (~nidx & 7);
	byte = data[off];
	if (!(byte & m)) {
		printk(KERN_CRIT "hfs: trying to free free bnode "
				"%u(%d)\n",
			node->this, node->type);
		kunmap(page);
		hfs_bnode_put(node);
		return;
	}
	data[off] = byte & ~m;
	set_page_dirty(page);
	kunmap(page);
	hfs_bnode_put(node);
	tree->free_nodes++;
	mark_inode_dirty(tree->inode);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfsplus/btree.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer (flar@allandria.com)
	6	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	7	*
	8	* Handle opening/closing btree
	9	*/
	10
	11	#include <linux/slab.h>
	12	#include <linux/pagemap.h>
e1b5c1d3	13	#include <linux/log2.h>
1da177e4 LT	14
	15	#include "hfsplus_fs.h"
	16	#include "hfsplus_raw.h"
	17
	18
	19	/* Get a reference to a BTree and do some initial checks /
	20	struct hfs_btree hfs_btree_open(struct super_block sb, u32 id)
	21	{
	22	struct hfs_btree *tree;
	23	struct hfs_btree_header_rec *head;
	24	struct address_space *mapping;
63525391	25	struct inode *inode;
1da177e4 LT	26	struct page *page;
	27	unsigned int size;
	28
f8314dc6	29	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
1da177e4 LT	30	if (!tree)
1da177e4 LT	31	return NULL;
1da177e4	32
467c3d9c	33	mutex_init(&tree->tree_lock);
1da177e4	34	spin_lock_init(&tree->hash_lock);
1da177e4 LT	35	tree->sb = sb;
1da177e4 LT	36	tree->cnid = id;
63525391 DH	37	inode = hfsplus_iget(sb, id);
63525391 DH	38	if (IS_ERR(inode))
1da177e4	39	goto free_tree;
63525391	40	tree->inode = inode;
1da177e4	41
ee527162 JM	42	if (!HFSPLUS_I(tree->inode)->first_blocks) {
	43	printk(KERN_ERR
	44	"hfs: invalid btree extent records (0 size).\n");
	45	goto free_inode;
	46	}
	47
1da177e4	48	mapping = tree->inode->i_mapping;
090d2b18	49	page = read_mapping_page(mapping, 0, NULL);
1da177e4	50	if (IS_ERR(page))
ee527162	51	goto free_inode;
1da177e4 LT	52
1da177e4 LT	53	/* Load the header */
2753cc28 AS	54	head = (struct hfs_btree_header_rec *)(kmap(page) +
2753cc28 AS	55	sizeof(struct hfs_bnode_desc));
1da177e4 LT	56	tree->root = be32_to_cpu(head->root);
	57	tree->leaf_count = be32_to_cpu(head->leaf_count);
	58	tree->leaf_head = be32_to_cpu(head->leaf_head);
	59	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	60	tree->node_count = be32_to_cpu(head->node_count);
	61	tree->free_nodes = be32_to_cpu(head->free_nodes);
	62	tree->attributes = be32_to_cpu(head->attributes);
	63	tree->node_size = be16_to_cpu(head->node_size);
	64	tree->max_key_len = be16_to_cpu(head->max_key_len);
	65	tree->depth = be16_to_cpu(head->depth);
	66
9250f925 ES	67	/* Verify the tree and set the correct compare function */
	68	switch (id) {
	69	case HFSPLUS_EXT_CNID:
	70	if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
	71	printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
	72	tree->max_key_len);
	73	goto fail_page;
	74	}
13571a69 CH	75	if (tree->attributes & HFS_TREE_VARIDXKEYS) {
	76	printk(KERN_ERR "hfs: invalid extent btree flag\n");
	77	goto fail_page;
	78	}
	79
2179d372	80	tree->keycmp = hfsplus_ext_cmp_key;
9250f925 ES	81	break;
	82	case HFSPLUS_CAT_CNID:
	83	if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
	84	printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
	85	tree->max_key_len);
	86	goto fail_page;
	87	}
13571a69 CH	88	if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
	89	printk(KERN_ERR "hfs: invalid catalog btree flag\n");
	90	goto fail_page;
	91	}
9250f925	92
84adede3	93	if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
2179d372 DE	94	(head->key_type == HFSPLUS_KEY_BINARY))
2179d372 DE	95	tree->keycmp = hfsplus_cat_bin_cmp_key;
d45bce8f	96	else {
2179d372	97	tree->keycmp = hfsplus_cat_case_cmp_key;
84adede3	98	set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
d45bce8f	99	}
9250f925 ES	100	break;
9250f925 ES	101	default:
2179d372 DE	102	printk(KERN_ERR "hfs: unknown B*Tree requested\n");
	103	goto fail_page;
	104	}
	105
13571a69 CH	106	if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
	107	printk(KERN_ERR "hfs: invalid btree flag\n");
	108	goto fail_page;
	109	}
	110
1da177e4	111	size = tree->node_size;
e1b5c1d3	112	if (!is_power_of_2(size))
1da177e4 LT	113	goto fail_page;
	114	if (!tree->node_count)
	115	goto fail_page;
9250f925	116
1da177e4 LT	117	tree->node_size_shift = ffs(size) - 1;
1da177e4 LT	118
2753cc28 AS	119	tree->pages_per_bnode =
	120	(tree->node_size + PAGE_CACHE_SIZE - 1) >>
	121	PAGE_CACHE_SHIFT;
1da177e4 LT	122
	123	kunmap(page);
	124	page_cache_release(page);
	125	return tree;
	126
	127	fail_page:
1da177e4	128	page_cache_release(page);
ee527162	129	free_inode:
9250f925	130	tree->inode->i_mapping->a_ops = &hfsplus_aops;
1da177e4	131	iput(tree->inode);
ee527162	132	free_tree:
1da177e4 LT	133	kfree(tree);
	134	return NULL;
	135	}
	136
	137	/* Release resources used by a btree */
	138	void hfs_btree_close(struct hfs_btree *tree)
	139	{
	140	struct hfs_bnode *node;
	141	int i;
	142
	143	if (!tree)
	144	return;
	145
	146	for (i = 0; i < NODE_HASH_SIZE; i++) {
	147	while ((node = tree->node_hash[i])) {
	148	tree->node_hash[i] = node->next_hash;
	149	if (atomic_read(&node->refcnt))
2753cc28 AS	150	printk(KERN_CRIT "hfs: node %d:%d "
	151	"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
81cc7fad	162	int hfs_btree_write(struct hfs_btree *tree)
1da177e4 LT	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? */
81cc7fad	171	return -EIO;
1da177e4 LT	172	/* Load the header */
1da177e4 LT	173	page = node->page[0];
2753cc28 AS	174	head = (struct hfs_btree_header_rec *)(kmap(page) +
2753cc28 AS	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
	186	kunmap(page);
	187	set_page_dirty(page);
	188	hfs_bnode_put(node);
81cc7fad	189	return 0;
1da177e4 LT	190	}
	191
	192	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	193	{
	194	struct hfs_btree *tree = prev->tree;
	195	struct hfs_bnode *node;
	196	struct hfs_bnode_desc desc;
	197	__be32 cnid;
	198
	199	node = hfs_bnode_create(tree, idx);
	200	if (IS_ERR(node))
	201	return node;
	202
	203	tree->free_nodes--;
	204	prev->next = idx;
	205	cnid = cpu_to_be32(idx);
	206	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	207
	208	node->type = HFS_NODE_MAP;
	209	node->num_recs = 1;
	210	hfs_bnode_clear(node, 0, tree->node_size);
	211	desc.next = 0;
	212	desc.prev = 0;
	213	desc.type = HFS_NODE_MAP;
	214	desc.height = 0;
	215	desc.num_recs = cpu_to_be16(1);
	216	desc.reserved = 0;
	217	hfs_bnode_write(node, &desc, 0, sizeof(desc));
	218	hfs_bnode_write_u16(node, 14, 0x8000);
	219	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
	220	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
	221
	222	return node;
	223	}
	224
	225	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
	226	{
	227	struct hfs_bnode node, next_node;
	228	struct page **pagep;
	229	u32 nidx, idx;
487798df AM	230	unsigned off;
	231	u16 off16;
	232	u16 len;
1da177e4 LT	233	u8 *data, byte, m;
	234	int i;
	235
	236	while (!tree->free_nodes) {
	237	struct inode *inode = tree->inode;
6af502de	238	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	239	u32 count;
	240	int res;
	241
	242	res = hfsplus_file_extend(inode);
	243	if (res)
	244	return ERR_PTR(res);
6af502de CH	245	hip->phys_size = inode->i_size =
6af502de CH	246	(loff_t)hip->alloc_blocks <<
dd73a01a	247	HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
6af502de CH	248	hip->fs_blocks =
6af502de CH	249	hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
1da177e4 LT	250	inode_set_bytes(inode, inode->i_size);
	251	count = inode->i_size >> tree->node_size_shift;
	252	tree->free_nodes = count - tree->node_count;
	253	tree->node_count = count;
	254	}
	255
	256	nidx = 0;
	257	node = hfs_bnode_find(tree, nidx);
	258	if (IS_ERR(node))
	259	return node;
487798df AM	260	len = hfs_brec_lenoff(node, 2, &off16);
487798df AM	261	off = off16;
1da177e4 LT	262
	263	off += node->page_offset;
	264	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	265	data = kmap(*pagep);
	266	off &= ~PAGE_CACHE_MASK;
	267	idx = 0;
	268
	269	for (;;) {
	270	while (len) {
	271	byte = data[off];
	272	if (byte != 0xff) {
	273	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
	274	if (!(byte & m)) {
	275	idx += i;
	276	data[off] \|= m;
	277	set_page_dirty(*pagep);
	278	kunmap(*pagep);
	279	tree->free_nodes--;
	280	mark_inode_dirty(tree->inode);
	281	hfs_bnode_put(node);
2753cc28 AS	282	return hfs_bnode_create(tree,
2753cc28 AS	283	idx);
1da177e4 LT	284	}
	285	}
	286	}
	287	if (++off >= PAGE_CACHE_SIZE) {
	288	kunmap(*pagep);
	289	data = kmap(*++pagep);
	290	off = 0;
	291	}
	292	idx += 8;
	293	len--;
	294	}
	295	kunmap(*pagep);
	296	nidx = node->next;
	297	if (!nidx) {
6d1bbfc4	298	dprint(DBG_BNODE_MOD, "hfs: create new bmap node.\n");
1da177e4 LT	299	next_node = hfs_bmap_new_bmap(node, idx);
	300	} else
	301	next_node = hfs_bnode_find(tree, nidx);
	302	hfs_bnode_put(node);
	303	if (IS_ERR(next_node))
	304	return next_node;
	305	node = next_node;
	306
487798df AM	307	len = hfs_brec_lenoff(node, 0, &off16);
487798df AM	308	off = off16;
1da177e4 LT	309	off += node->page_offset;
	310	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	311	data = kmap(*pagep);
	312	off &= ~PAGE_CACHE_MASK;
	313	}
	314	}
	315
	316	void hfs_bmap_free(struct hfs_bnode *node)
	317	{
	318	struct hfs_btree *tree;
	319	struct page *page;
	320	u16 off, len;
	321	u32 nidx;
	322	u8 *data, byte, m;
	323
	324	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
0bf3ba53	325	BUG_ON(!node->this);
1da177e4 LT	326	tree = node->tree;
	327	nidx = node->this;
	328	node = hfs_bnode_find(tree, 0);
	329	if (IS_ERR(node))
	330	return;
	331	len = hfs_brec_lenoff(node, 2, &off);
	332	while (nidx >= len * 8) {
	333	u32 i;
	334
	335	nidx -= len * 8;
	336	i = node->next;
	337	hfs_bnode_put(node);
	338	if (!i) {
	339	/* panic */;
2753cc28 AS	340	printk(KERN_CRIT "hfs: unable to free bnode %u. "
	341	"bmap not found!\n",
	342	node->this);
1da177e4 LT	343	return;
	344	}
	345	node = hfs_bnode_find(tree, i);
	346	if (IS_ERR(node))
	347	return;
	348	if (node->type != HFS_NODE_MAP) {
	349	/* panic */;
2753cc28 AS	350	printk(KERN_CRIT "hfs: invalid bmap found! "
	351	"(%u,%d)\n",
	352	node->this, node->type);
1da177e4 LT	353	hfs_bnode_put(node);
	354	return;
	355	}
	356	len = hfs_brec_lenoff(node, 0, &off);
	357	}
	358	off += node->page_offset + nidx / 8;
	359	page = node->page[off >> PAGE_CACHE_SHIFT];
	360	data = kmap(page);
	361	off &= ~PAGE_CACHE_MASK;
	362	m = 1 << (~nidx & 7);
	363	byte = data[off];
	364	if (!(byte & m)) {
2753cc28 AS	365	printk(KERN_CRIT "hfs: trying to free free bnode "
	366	"%u(%d)\n",
	367	node->this, node->type);
1da177e4 LT	368	kunmap(page);
	369	hfs_bnode_put(node);
	370	return;
	371	}
	372	data[off] = byte & ~m;
	373	set_page_dirty(page);
	374	kunmap(page);
	375	hfs_bnode_put(node);
	376	tree->free_nodes++;
	377	mark_inode_dirty(tree->inode);
	378	}