[net-next-2.6.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);
}

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(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);
}

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) {
			printk(KERN_DEBUG "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
	53	/* Load the header */
	54	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	55	tree->root = be32_to_cpu(head->root);
	56	tree->leaf_count = be32_to_cpu(head->leaf_count);
	57	tree->leaf_head = be32_to_cpu(head->leaf_head);
	58	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	59	tree->node_count = be32_to_cpu(head->node_count);
	60	tree->free_nodes = be32_to_cpu(head->free_nodes);
	61	tree->attributes = be32_to_cpu(head->attributes);
	62	tree->node_size = be16_to_cpu(head->node_size);
	63	tree->max_key_len = be16_to_cpu(head->max_key_len);
	64	tree->depth = be16_to_cpu(head->depth);
	65
9250f925 ES	66	/* Verify the tree and set the correct compare function */
	67	switch (id) {
	68	case HFSPLUS_EXT_CNID:
	69	if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
	70	printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
	71	tree->max_key_len);
	72	goto fail_page;
	73	}
13571a69 CH	74	if (tree->attributes & HFS_TREE_VARIDXKEYS) {
	75	printk(KERN_ERR "hfs: invalid extent btree flag\n");
	76	goto fail_page;
	77	}
	78
2179d372	79	tree->keycmp = hfsplus_ext_cmp_key;
9250f925 ES	80	break;
	81	case HFSPLUS_CAT_CNID:
	82	if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
	83	printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
	84	tree->max_key_len);
	85	goto fail_page;
	86	}
13571a69 CH	87	if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
	88	printk(KERN_ERR "hfs: invalid catalog btree flag\n");
	89	goto fail_page;
	90	}
9250f925	91
84adede3	92	if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
2179d372 DE	93	(head->key_type == HFSPLUS_KEY_BINARY))
2179d372 DE	94	tree->keycmp = hfsplus_cat_bin_cmp_key;
d45bce8f	95	else {
2179d372	96	tree->keycmp = hfsplus_cat_case_cmp_key;
84adede3	97	set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
d45bce8f	98	}
9250f925 ES	99	break;
9250f925 ES	100	default:
2179d372 DE	101	printk(KERN_ERR "hfs: unknown B*Tree requested\n");
	102	goto fail_page;
	103	}
	104
13571a69 CH	105	if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
	106	printk(KERN_ERR "hfs: invalid btree flag\n");
	107	goto fail_page;
	108	}
	109
1da177e4	110	size = tree->node_size;
e1b5c1d3	111	if (!is_power_of_2(size))
1da177e4 LT	112	goto fail_page;
	113	if (!tree->node_count)
	114	goto fail_page;
9250f925	115
1da177e4 LT	116	tree->node_size_shift = ffs(size) - 1;
	117
	118	tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
	119
	120	kunmap(page);
	121	page_cache_release(page);
	122	return tree;
	123
	124	fail_page:
1da177e4	125	page_cache_release(page);
ee527162	126	free_inode:
9250f925	127	tree->inode->i_mapping->a_ops = &hfsplus_aops;
1da177e4	128	iput(tree->inode);
ee527162	129	free_tree:
1da177e4 LT	130	kfree(tree);
	131	return NULL;
	132	}
	133
	134	/* Release resources used by a btree */
	135	void hfs_btree_close(struct hfs_btree *tree)
	136	{
	137	struct hfs_bnode *node;
	138	int i;
	139
	140	if (!tree)
	141	return;
	142
	143	for (i = 0; i < NODE_HASH_SIZE; i++) {
	144	while ((node = tree->node_hash[i])) {
	145	tree->node_hash[i] = node->next_hash;
	146	if (atomic_read(&node->refcnt))
634725a9	147	printk(KERN_CRIT "hfs: node %d:%d still has %d user(s)!\n",
1da177e4 LT	148	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	149	hfs_bnode_free(node);
	150	tree->node_hash_cnt--;
	151	}
	152	}
	153	iput(tree->inode);
	154	kfree(tree);
	155	}
	156
	157	void hfs_btree_write(struct hfs_btree *tree)
	158	{
	159	struct hfs_btree_header_rec *head;
	160	struct hfs_bnode *node;
	161	struct page *page;
	162
	163	node = hfs_bnode_find(tree, 0);
	164	if (IS_ERR(node))
	165	/* panic? */
	166	return;
	167	/* Load the header */
	168	page = node->page[0];
	169	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	170
	171	head->root = cpu_to_be32(tree->root);
	172	head->leaf_count = cpu_to_be32(tree->leaf_count);
	173	head->leaf_head = cpu_to_be32(tree->leaf_head);
	174	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	175	head->node_count = cpu_to_be32(tree->node_count);
	176	head->free_nodes = cpu_to_be32(tree->free_nodes);
	177	head->attributes = cpu_to_be32(tree->attributes);
	178	head->depth = cpu_to_be16(tree->depth);
	179
	180	kunmap(page);
	181	set_page_dirty(page);
	182	hfs_bnode_put(node);
	183	}
	184
	185	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	186	{
	187	struct hfs_btree *tree = prev->tree;
	188	struct hfs_bnode *node;
	189	struct hfs_bnode_desc desc;
	190	__be32 cnid;
	191
	192	node = hfs_bnode_create(tree, idx);
	193	if (IS_ERR(node))
	194	return node;
	195
	196	tree->free_nodes--;
	197	prev->next = idx;
	198	cnid = cpu_to_be32(idx);
	199	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	200
	201	node->type = HFS_NODE_MAP;
	202	node->num_recs = 1;
	203	hfs_bnode_clear(node, 0, tree->node_size);
	204	desc.next = 0;
	205	desc.prev = 0;
	206	desc.type = HFS_NODE_MAP;
	207	desc.height = 0;
	208	desc.num_recs = cpu_to_be16(1);
	209	desc.reserved = 0;
	210	hfs_bnode_write(node, &desc, 0, sizeof(desc));
	211	hfs_bnode_write_u16(node, 14, 0x8000);
212	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
213	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
214
215	return node;
216	}
217
218	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
219	{
220	struct hfs_bnode node, next_node;
221	struct page **pagep;
222	u32 nidx, idx;
487798df AM	223	unsigned off;
	224	u16 off16;
	225	u16 len;
1da177e4 LT	226	u8 *data, byte, m;
	227	int i;
	228
	229	while (!tree->free_nodes) {
	230	struct inode *inode = tree->inode;
6af502de	231	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	232	u32 count;
	233	int res;
	234
	235	res = hfsplus_file_extend(inode);
	236	if (res)
	237	return ERR_PTR(res);
6af502de CH	238	hip->phys_size = inode->i_size =
6af502de CH	239	(loff_t)hip->alloc_blocks <<
dd73a01a	240	HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
6af502de CH	241	hip->fs_blocks =
6af502de CH	242	hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
1da177e4 LT	243	inode_set_bytes(inode, inode->i_size);
	244	count = inode->i_size >> tree->node_size_shift;
	245	tree->free_nodes = count - tree->node_count;
	246	tree->node_count = count;
	247	}
	248
	249	nidx = 0;
	250	node = hfs_bnode_find(tree, nidx);
	251	if (IS_ERR(node))
	252	return node;
487798df AM	253	len = hfs_brec_lenoff(node, 2, &off16);
487798df AM	254	off = off16;
1da177e4 LT	255
	256	off += node->page_offset;
	257	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	258	data = kmap(*pagep);
	259	off &= ~PAGE_CACHE_MASK;
	260	idx = 0;
	261
	262	for (;;) {
	263	while (len) {
	264	byte = data[off];
	265	if (byte != 0xff) {
	266	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
	267	if (!(byte & m)) {
	268	idx += i;
	269	data[off] \|= m;
	270	set_page_dirty(*pagep);
	271	kunmap(*pagep);
	272	tree->free_nodes--;
	273	mark_inode_dirty(tree->inode);
	274	hfs_bnode_put(node);
1da177e4 LT	275	return hfs_bnode_create(tree, idx);
	276	}
	277	}
	278	}
	279	if (++off >= PAGE_CACHE_SIZE) {
	280	kunmap(*pagep);
	281	data = kmap(*++pagep);
	282	off = 0;
	283	}
	284	idx += 8;
	285	len--;
	286	}
	287	kunmap(*pagep);
	288	nidx = node->next;
	289	if (!nidx) {
634725a9	290	printk(KERN_DEBUG "hfs: create new bmap node...\n");
1da177e4 LT	291	next_node = hfs_bmap_new_bmap(node, idx);
	292	} else
	293	next_node = hfs_bnode_find(tree, nidx);
	294	hfs_bnode_put(node);
	295	if (IS_ERR(next_node))
	296	return next_node;
	297	node = next_node;
	298
487798df AM	299	len = hfs_brec_lenoff(node, 0, &off16);
487798df AM	300	off = off16;
1da177e4 LT	301	off += node->page_offset;
	302	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	303	data = kmap(*pagep);
	304	off &= ~PAGE_CACHE_MASK;
	305	}
	306	}
	307
	308	void hfs_bmap_free(struct hfs_bnode *node)
	309	{
	310	struct hfs_btree *tree;
	311	struct page *page;
	312	u16 off, len;
	313	u32 nidx;
	314	u8 *data, byte, m;
	315
	316	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
0bf3ba53	317	BUG_ON(!node->this);
1da177e4 LT	318	tree = node->tree;
	319	nidx = node->this;
	320	node = hfs_bnode_find(tree, 0);
	321	if (IS_ERR(node))
	322	return;
	323	len = hfs_brec_lenoff(node, 2, &off);
	324	while (nidx >= len * 8) {
	325	u32 i;
	326
	327	nidx -= len * 8;
	328	i = node->next;
	329	hfs_bnode_put(node);
	330	if (!i) {
	331	/* panic */;
634725a9	332	printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
1da177e4 LT	333	return;
	334	}
	335	node = hfs_bnode_find(tree, i);
	336	if (IS_ERR(node))
	337	return;
	338	if (node->type != HFS_NODE_MAP) {
	339	/* panic */;
634725a9	340	printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
1da177e4 LT	341	hfs_bnode_put(node);
	342	return;
	343	}
	344	len = hfs_brec_lenoff(node, 0, &off);
	345	}
	346	off += node->page_offset + nidx / 8;
	347	page = node->page[off >> PAGE_CACHE_SHIFT];
	348	data = kmap(page);
	349	off &= ~PAGE_CACHE_MASK;
	350	m = 1 << (~nidx & 7);
	351	byte = data[off];
	352	if (!(byte & m)) {
634725a9	353	printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
1da177e4 LT	354	kunmap(page);
	355	hfs_bnode_put(node);
	356	return;
	357	}
	358	data[off] = byte & ~m;
	359	set_page_dirty(page);
	360	kunmap(page);
	361	hfs_bnode_put(node);
	362	tree->free_nodes++;
	363	mark_inode_dirty(tree->inode);
	364	}