[linux-2.6-block.git] / fs / hfs / bnode.c

/*
 *  linux/fs/hfs/bnode.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Handle basic btree node operations
 */

#include <linux/pagemap.h>
#include <linux/swap.h>

#include "btree.h"

void hfs_bnode_read(struct hfs_bnode *node, void *buf,
		int off, int len)
{
	struct page *page;

	off += node->page_offset;
	page = node->page[0];

	memcpy(buf, kmap(page) + off, len);
	kunmap(page);
}

u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
{
	__be16 data;
	// optimize later...
	hfs_bnode_read(node, &data, off, 2);
	return be16_to_cpu(data);
}

u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
{
	u8 data;
	// optimize later...
	hfs_bnode_read(node, &data, off, 1);
	return data;
}

void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
{
	struct hfs_btree *tree;
	int key_len;

	tree = node->tree;
	if (node->type == HFS_NODE_LEAF ||
	    tree->attributes & HFS_TREE_VARIDXKEYS)
		key_len = hfs_bnode_read_u8(node, off) + 1;
	else
		key_len = tree->max_key_len + 1;

	hfs_bnode_read(node, key, off, key_len);
}

void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
{
	struct page *page;

	off += node->page_offset;
	page = node->page[0];

	memcpy(kmap(page) + off, buf, len);
	kunmap(page);
	set_page_dirty(page);
}

void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
{
	__be16 v = cpu_to_be16(data);
	// optimize later...
	hfs_bnode_write(node, &v, off, 2);
}

void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
{
	// optimize later...
	hfs_bnode_write(node, &data, off, 1);
}

void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
{
	struct page *page;

	off += node->page_offset;
	page = node->page[0];

	memset(kmap(page) + off, 0, len);
	kunmap(page);
	set_page_dirty(page);
}

void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
		struct hfs_bnode *src_node, int src, int len)
{
	struct hfs_btree *tree;
	struct page *src_page, *dst_page;

	dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
	if (!len)
		return;
	tree = src_node->tree;
	src += src_node->page_offset;
	dst += dst_node->page_offset;
	src_page = src_node->page[0];
	dst_page = dst_node->page[0];

	memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
	kunmap(src_page);
	kunmap(dst_page);
	set_page_dirty(dst_page);
}

void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
{
	struct page *page;
	void *ptr;

	dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
	if (!len)
		return;
	src += node->page_offset;
	dst += node->page_offset;
	page = node->page[0];
	ptr = kmap(page);
	memmove(ptr + dst, ptr + src, len);
	kunmap(page);
	set_page_dirty(page);
}

void hfs_bnode_dump(struct hfs_bnode *node)
{
	struct hfs_bnode_desc desc;
	__be32 cnid;
	int i, off, key_off;

	dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
	hfs_bnode_read(node, &desc, 0, sizeof(desc));
	dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
		be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
		desc.type, desc.height, be16_to_cpu(desc.num_recs));

	off = node->tree->node_size - 2;
	for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
		key_off = hfs_bnode_read_u16(node, off);
		dprint(DBG_BNODE_MOD, " %d", key_off);
		if (i && node->type == HFS_NODE_INDEX) {
			int tmp;

			if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
				tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
			else
				tmp = node->tree->max_key_len + 1;
			dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
			hfs_bnode_read(node, &cnid, key_off + tmp, 4);
			dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
		} else if (i && node->type == HFS_NODE_LEAF) {
			int tmp;

			tmp = hfs_bnode_read_u8(node, key_off);
			dprint(DBG_BNODE_MOD, " (%d)", tmp);
		}
	}
	dprint(DBG_BNODE_MOD, "\n");
}

void hfs_bnode_unlink(struct hfs_bnode *node)
{
	struct hfs_btree *tree;
	struct hfs_bnode *tmp;
	__be32 cnid;

	tree = node->tree;
	if (node->prev) {
		tmp = hfs_bnode_find(tree, node->prev);
		if (IS_ERR(tmp))
			return;
		tmp->next = node->next;
		cnid = cpu_to_be32(tmp->next);
		hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
		hfs_bnode_put(tmp);
	} else if (node->type == HFS_NODE_LEAF)
		tree->leaf_head = node->next;

	if (node->next) {
		tmp = hfs_bnode_find(tree, node->next);
		if (IS_ERR(tmp))
			return;
		tmp->prev = node->prev;
		cnid = cpu_to_be32(tmp->prev);
		hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
		hfs_bnode_put(tmp);
	} else if (node->type == HFS_NODE_LEAF)
		tree->leaf_tail = node->prev;

	// move down?
	if (!node->prev && !node->next) {
		printk(KERN_DEBUG "hfs_btree_del_level\n");
	}
	if (!node->parent) {
		tree->root = 0;
		tree->depth = 0;
	}
	set_bit(HFS_BNODE_DELETED, &node->flags);
}

static inline int hfs_bnode_hash(u32 num)
{
	num = (num >> 16) + num;
	num += num >> 8;
	return num & (NODE_HASH_SIZE - 1);
}

struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
{
	struct hfs_bnode *node;

	if (cnid >= tree->node_count) {
		printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
		return NULL;
	}

	for (node = tree->node_hash[hfs_bnode_hash(cnid)];
	     node; node = node->next_hash) {
		if (node->this == cnid) {
			return node;
		}
	}
	return NULL;
}

static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
{
	struct super_block *sb;
	struct hfs_bnode *node, *node2;
	struct address_space *mapping;
	struct page *page;
	int size, block, i, hash;
	loff_t off;

	if (cnid >= tree->node_count) {
		printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
		return NULL;
	}

	sb = tree->inode->i_sb;
	size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
		sizeof(struct page *);
	node = kzalloc(size, GFP_KERNEL);
	if (!node)
		return NULL;
	node->tree = tree;
	node->this = cnid;
	set_bit(HFS_BNODE_NEW, &node->flags);
	atomic_set(&node->refcnt, 1);
	dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
	       node->tree->cnid, node->this);
	init_waitqueue_head(&node->lock_wq);
	spin_lock(&tree->hash_lock);
	node2 = hfs_bnode_findhash(tree, cnid);
	if (!node2) {
		hash = hfs_bnode_hash(cnid);
		node->next_hash = tree->node_hash[hash];
		tree->node_hash[hash] = node;
		tree->node_hash_cnt++;
	} else {
		spin_unlock(&tree->hash_lock);
		kfree(node);
		wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
		return node2;
	}
	spin_unlock(&tree->hash_lock);

	mapping = tree->inode->i_mapping;
	off = (loff_t)cnid * tree->node_size;
	block = off >> PAGE_CACHE_SHIFT;
	node->page_offset = off & ~PAGE_CACHE_MASK;
	for (i = 0; i < tree->pages_per_bnode; i++) {
		page = read_mapping_page(mapping, block++, NULL);
		if (IS_ERR(page))
			goto fail;
		if (PageError(page)) {
			page_cache_release(page);
			goto fail;
		}
		page_cache_release(page);
		node->page[i] = page;
	}

	return node;
fail:
	set_bit(HFS_BNODE_ERROR, &node->flags);
	return node;
}

void hfs_bnode_unhash(struct hfs_bnode *node)
{
	struct hfs_bnode **p;

	dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
		node->tree->cnid, node->this, atomic_read(&node->refcnt));
	for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
	     *p && *p != node; p = &(*p)->next_hash)
		;
	BUG_ON(!*p);
	*p = node->next_hash;
	node->tree->node_hash_cnt--;
}

/* Load a particular node out of a tree */
struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
{
	struct hfs_bnode *node;
	struct hfs_bnode_desc *desc;
	int i, rec_off, off, next_off;
	int entry_size, key_size;

	spin_lock(&tree->hash_lock);
	node = hfs_bnode_findhash(tree, num);
	if (node) {
		hfs_bnode_get(node);
		spin_unlock(&tree->hash_lock);
		wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
		if (test_bit(HFS_BNODE_ERROR, &node->flags))
			goto node_error;
		return node;
	}
	spin_unlock(&tree->hash_lock);
	node = __hfs_bnode_create(tree, num);
	if (!node)
		return ERR_PTR(-ENOMEM);
	if (test_bit(HFS_BNODE_ERROR, &node->flags))
		goto node_error;
	if (!test_bit(HFS_BNODE_NEW, &node->flags))
		return node;

	desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
	node->prev = be32_to_cpu(desc->prev);
	node->next = be32_to_cpu(desc->next);
	node->num_recs = be16_to_cpu(desc->num_recs);
	node->type = desc->type;
	node->height = desc->height;
	kunmap(node->page[0]);

	switch (node->type) {
	case HFS_NODE_HEADER:
	case HFS_NODE_MAP:
		if (node->height != 0)
			goto node_error;
		break;
	case HFS_NODE_LEAF:
		if (node->height != 1)
			goto node_error;
		break;
	case HFS_NODE_INDEX:
		if (node->height <= 1 || node->height > tree->depth)
			goto node_error;
		break;
	default:
		goto node_error;
	}

	rec_off = tree->node_size - 2;
	off = hfs_bnode_read_u16(node, rec_off);
	if (off != sizeof(struct hfs_bnode_desc))
		goto node_error;
	for (i = 1; i <= node->num_recs; off = next_off, i++) {
		rec_off -= 2;
		next_off = hfs_bnode_read_u16(node, rec_off);
		if (next_off <= off ||
		    next_off > tree->node_size ||
		    next_off & 1)
			goto node_error;
		entry_size = next_off - off;
		if (node->type != HFS_NODE_INDEX &&
		    node->type != HFS_NODE_LEAF)
			continue;
		key_size = hfs_bnode_read_u8(node, off) + 1;
		if (key_size >= entry_size /*|| key_size & 1*/)
			goto node_error;
	}
	clear_bit(HFS_BNODE_NEW, &node->flags);
	wake_up(&node->lock_wq);
	return node;

node_error:
	set_bit(HFS_BNODE_ERROR, &node->flags);
	clear_bit(HFS_BNODE_NEW, &node->flags);
	wake_up(&node->lock_wq);
	hfs_bnode_put(node);
	return ERR_PTR(-EIO);
}

void hfs_bnode_free(struct hfs_bnode *node)
{
	//int i;

	//for (i = 0; i < node->tree->pages_per_bnode; i++)
	//	if (node->page[i])
	//		page_cache_release(node->page[i]);
	kfree(node);
}

struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
{
	struct hfs_bnode *node;
	struct page **pagep;
	int i;

	spin_lock(&tree->hash_lock);
	node = hfs_bnode_findhash(tree, num);
	spin_unlock(&tree->hash_lock);
	BUG_ON(node);
	node = __hfs_bnode_create(tree, num);
	if (!node)
		return ERR_PTR(-ENOMEM);
	if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
		hfs_bnode_put(node);
		return ERR_PTR(-EIO);
	}

	pagep = node->page;
	memset(kmap(*pagep) + node->page_offset, 0,
	       min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
	set_page_dirty(*pagep);
	kunmap(*pagep);
	for (i = 1; i < tree->pages_per_bnode; i++) {
		memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
		set_page_dirty(*pagep);
		kunmap(*pagep);
	}
	clear_bit(HFS_BNODE_NEW, &node->flags);
	wake_up(&node->lock_wq);

	return node;
}

void hfs_bnode_get(struct hfs_bnode *node)
{
	if (node) {
		atomic_inc(&node->refcnt);
		dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
		       node->tree->cnid, node->this, atomic_read(&node->refcnt));
	}
}

/* Dispose of resources used by a node */
void hfs_bnode_put(struct hfs_bnode *node)
{
	if (node) {
		struct hfs_btree *tree = node->tree;
		int i;

		dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
		       node->tree->cnid, node->this, atomic_read(&node->refcnt));
		BUG_ON(!atomic_read(&node->refcnt));
		if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
			return;
		for (i = 0; i < tree->pages_per_bnode; i++) {
			if (!node->page[i])
				continue;
			mark_page_accessed(node->page[i]);
		}

		if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
			hfs_bnode_unhash(node);
			spin_unlock(&tree->hash_lock);
			hfs_bmap_free(node);
			hfs_bnode_free(node);
			return;
		}
		spin_unlock(&tree->hash_lock);
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfs/bnode.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer (flar@allandria.com)
	6	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	7	*
	8	* Handle basic btree node operations
	9	*/
	10
	11	#include <linux/pagemap.h>
	12	#include <linux/swap.h>
	13
	14	#include "btree.h"
	15
1da177e4 LT	16	void hfs_bnode_read(struct hfs_bnode node, void buf,
	17	int off, int len)
	18	{
	19	struct page *page;
	20
	21	off += node->page_offset;
	22	page = node->page[0];
	23
	24	memcpy(buf, kmap(page) + off, len);
	25	kunmap(page);
	26	}
	27
	28	u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
	29	{
	30	__be16 data;
	31	// optimize later...
	32	hfs_bnode_read(node, &data, off, 2);
	33	return be16_to_cpu(data);
	34	}
	35
	36	u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
	37	{
	38	u8 data;
	39	// optimize later...
	40	hfs_bnode_read(node, &data, off, 1);
	41	return data;
	42	}
	43
	44	void hfs_bnode_read_key(struct hfs_bnode node, void key, int off)
	45	{
	46	struct hfs_btree *tree;
	47	int key_len;
	48
	49	tree = node->tree;
	50	if (node->type == HFS_NODE_LEAF \|\|
	51	tree->attributes & HFS_TREE_VARIDXKEYS)
	52	key_len = hfs_bnode_read_u8(node, off) + 1;
	53	else
	54	key_len = tree->max_key_len + 1;
	55
	56	hfs_bnode_read(node, key, off, key_len);
	57	}
	58
	59	void hfs_bnode_write(struct hfs_bnode node, void buf, int off, int len)
	60	{
	61	struct page *page;
	62
	63	off += node->page_offset;
	64	page = node->page[0];
	65
	66	memcpy(kmap(page) + off, buf, len);
	67	kunmap(page);
	68	set_page_dirty(page);
	69	}
	70
	71	void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
	72	{
	73	__be16 v = cpu_to_be16(data);
	74	// optimize later...
	75	hfs_bnode_write(node, &v, off, 2);
	76	}
	77
	78	void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
	79	{
80	// optimize later...
81	hfs_bnode_write(node, &data, off, 1);
82	}
83
84	void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
85	{
86	struct page *page;
87
88	off += node->page_offset;
89	page = node->page[0];
90
91	memset(kmap(page) + off, 0, len);
92	kunmap(page);
93	set_page_dirty(page);
94	}
95
96	void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
97	struct hfs_bnode *src_node, int src, int len)
98	{
99	struct hfs_btree *tree;
100	struct page src_page, dst_page;
101
102	dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
103	if (!len)
104	return;
105	tree = src_node->tree;
106	src += src_node->page_offset;
107	dst += dst_node->page_offset;
108	src_page = src_node->page[0];
109	dst_page = dst_node->page[0];
110
111	memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
112	kunmap(src_page);
113	kunmap(dst_page);
114	set_page_dirty(dst_page);
115	}
116
117	void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
118	{
119	struct page *page;
120	void *ptr;
121
122	dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
123	if (!len)
124	return;
125	src += node->page_offset;
126	dst += node->page_offset;
127	page = node->page[0];
128	ptr = kmap(page);
129	memmove(ptr + dst, ptr + src, len);
130	kunmap(page);
131	set_page_dirty(page);
132	}
133
134	void hfs_bnode_dump(struct hfs_bnode *node)
135	{
136	struct hfs_bnode_desc desc;
137	__be32 cnid;
138	int i, off, key_off;
139
140	dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
141	hfs_bnode_read(node, &desc, 0, sizeof(desc));
142	dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
143	be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
144	desc.type, desc.height, be16_to_cpu(desc.num_recs));
145
146	off = node->tree->node_size - 2;
147	for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
148	key_off = hfs_bnode_read_u16(node, off);
149	dprint(DBG_BNODE_MOD, " %d", key_off);
150	if (i && node->type == HFS_NODE_INDEX) {
151	int tmp;
152
153	if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
154	tmp = (hfs_bnode_read_u8(node, key_off) \| 1) + 1;
155	else
156	tmp = node->tree->max_key_len + 1;
157	dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
158	hfs_bnode_read(node, &cnid, key_off + tmp, 4);
159	dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
160	} else if (i && node->type == HFS_NODE_LEAF) {
161	int tmp;
162
163	tmp = hfs_bnode_read_u8(node, key_off);
164	dprint(DBG_BNODE_MOD, " (%d)", tmp);
165	}
166	}
167	dprint(DBG_BNODE_MOD, "\n");
168	}
169
170	void hfs_bnode_unlink(struct hfs_bnode *node)
171	{
172	struct hfs_btree *tree;
173	struct hfs_bnode *tmp;
174	__be32 cnid;
175
176	tree = node->tree;
177	if (node->prev) {
178	tmp = hfs_bnode_find(tree, node->prev);
179	if (IS_ERR(tmp))
180	return;
181	tmp->next = node->next;
182	cnid = cpu_to_be32(tmp->next);
183	hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
184	hfs_bnode_put(tmp);
185	} else if (node->type == HFS_NODE_LEAF)
186	tree->leaf_head = node->next;
187
188	if (node->next) {
189	tmp = hfs_bnode_find(tree, node->next);
190	if (IS_ERR(tmp))
191	return;
192	tmp->prev = node->prev;
193	cnid = cpu_to_be32(tmp->prev);
194	hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
195	hfs_bnode_put(tmp);
196	} else if (node->type == HFS_NODE_LEAF)
197	tree->leaf_tail = node->prev;
198
199	// move down?
200	if (!node->prev && !node->next) {
7cf3cc30	201	printk(KERN_DEBUG "hfs_btree_del_level\n");
1da177e4 LT	202	}
	203	if (!node->parent) {
	204	tree->root = 0;
	205	tree->depth = 0;
	206	}
	207	set_bit(HFS_BNODE_DELETED, &node->flags);
	208	}
	209
	210	static inline int hfs_bnode_hash(u32 num)
	211	{
	212	num = (num >> 16) + num;
	213	num += num >> 8;
	214	return num & (NODE_HASH_SIZE - 1);
	215	}
	216
	217	struct hfs_bnode hfs_bnode_findhash(struct hfs_btree tree, u32 cnid)
	218	{
	219	struct hfs_bnode *node;
	220
	221	if (cnid >= tree->node_count) {
7cf3cc30	222	printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
1da177e4 LT	223	return NULL;
	224	}
	225
	226	for (node = tree->node_hash[hfs_bnode_hash(cnid)];
	227	node; node = node->next_hash) {
	228	if (node->this == cnid) {
	229	return node;
	230	}
	231	}
	232	return NULL;
	233	}
	234
	235	static struct hfs_bnode __hfs_bnode_create(struct hfs_btree tree, u32 cnid)
	236	{
	237	struct super_block *sb;
	238	struct hfs_bnode node, node2;
	239	struct address_space *mapping;
	240	struct page *page;
	241	int size, block, i, hash;
	242	loff_t off;
	243
	244	if (cnid >= tree->node_count) {
7cf3cc30	245	printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
1da177e4 LT	246	return NULL;
	247	}
	248
	249	sb = tree->inode->i_sb;
	250	size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
	251	sizeof(struct page *);
f8314dc6	252	node = kzalloc(size, GFP_KERNEL);
1da177e4 LT	253	if (!node)
1da177e4 LT	254	return NULL;
1da177e4 LT	255	node->tree = tree;
	256	node->this = cnid;
	257	set_bit(HFS_BNODE_NEW, &node->flags);
	258	atomic_set(&node->refcnt, 1);
	259	dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
	260	node->tree->cnid, node->this);
	261	init_waitqueue_head(&node->lock_wq);
	262	spin_lock(&tree->hash_lock);
	263	node2 = hfs_bnode_findhash(tree, cnid);
	264	if (!node2) {
	265	hash = hfs_bnode_hash(cnid);
	266	node->next_hash = tree->node_hash[hash];
	267	tree->node_hash[hash] = node;
	268	tree->node_hash_cnt++;
	269	} else {
	270	spin_unlock(&tree->hash_lock);
	271	kfree(node);
	272	wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
	273	return node2;
	274	}
	275	spin_unlock(&tree->hash_lock);
	276
	277	mapping = tree->inode->i_mapping;
	278	off = (loff_t)cnid * tree->node_size;
	279	block = off >> PAGE_CACHE_SHIFT;
	280	node->page_offset = off & ~PAGE_CACHE_MASK;
	281	for (i = 0; i < tree->pages_per_bnode; i++) {
090d2b18	282	page = read_mapping_page(mapping, block++, NULL);
1da177e4 LT	283	if (IS_ERR(page))
	284	goto fail;
	285	if (PageError(page)) {
	286	page_cache_release(page);
	287	goto fail;
	288	}
1da177e4	289	page_cache_release(page);
1da177e4 LT	290	node->page[i] = page;
	291	}
	292
	293	return node;
	294	fail:
	295	set_bit(HFS_BNODE_ERROR, &node->flags);
	296	return node;
	297	}
	298
	299	void hfs_bnode_unhash(struct hfs_bnode *node)
	300	{
	301	struct hfs_bnode **p;
	302
	303	dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
	304	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	305	for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
	306	p && p != node; p = &(*p)->next_hash)
	307	;
4d4ef9ab	308	BUG_ON(!*p);
1da177e4 LT	309	*p = node->next_hash;
	310	node->tree->node_hash_cnt--;
	311	}
	312
	313	/* Load a particular node out of a tree */
	314	struct hfs_bnode hfs_bnode_find(struct hfs_btree tree, u32 num)
	315	{
	316	struct hfs_bnode *node;
	317	struct hfs_bnode_desc *desc;
	318	int i, rec_off, off, next_off;
	319	int entry_size, key_size;
	320
	321	spin_lock(&tree->hash_lock);
	322	node = hfs_bnode_findhash(tree, num);
	323	if (node) {
	324	hfs_bnode_get(node);
	325	spin_unlock(&tree->hash_lock);
	326	wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
	327	if (test_bit(HFS_BNODE_ERROR, &node->flags))
	328	goto node_error;
	329	return node;
	330	}
	331	spin_unlock(&tree->hash_lock);
	332	node = __hfs_bnode_create(tree, num);
	333	if (!node)
	334	return ERR_PTR(-ENOMEM);
	335	if (test_bit(HFS_BNODE_ERROR, &node->flags))
	336	goto node_error;
	337	if (!test_bit(HFS_BNODE_NEW, &node->flags))
	338	return node;
	339
	340	desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
	341	node->prev = be32_to_cpu(desc->prev);
	342	node->next = be32_to_cpu(desc->next);
	343	node->num_recs = be16_to_cpu(desc->num_recs);
	344	node->type = desc->type;
	345	node->height = desc->height;
	346	kunmap(node->page[0]);
	347
	348	switch (node->type) {
	349	case HFS_NODE_HEADER:
	350	case HFS_NODE_MAP:
	351	if (node->height != 0)
	352	goto node_error;
	353	break;
	354	case HFS_NODE_LEAF:
	355	if (node->height != 1)
	356	goto node_error;
	357	break;
	358	case HFS_NODE_INDEX:
	359	if (node->height <= 1 \|\| node->height > tree->depth)
	360	goto node_error;
	361	break;
	362	default:
	363	goto node_error;
	364	}
	365
	366	rec_off = tree->node_size - 2;
	367	off = hfs_bnode_read_u16(node, rec_off);
	368	if (off != sizeof(struct hfs_bnode_desc))
	369	goto node_error;
	370	for (i = 1; i <= node->num_recs; off = next_off, i++) {
	371	rec_off -= 2;
	372	next_off = hfs_bnode_read_u16(node, rec_off);
373	if (next_off <= off \|\|
374	next_off > tree->node_size \|\|
375	next_off & 1)
376	goto node_error;
377	entry_size = next_off - off;
378	if (node->type != HFS_NODE_INDEX &&
379	node->type != HFS_NODE_LEAF)
380	continue;
381	key_size = hfs_bnode_read_u8(node, off) + 1;
382	if (key_size >= entry_size /\|\| key_size & 1/)
383	goto node_error;
384	}
385	clear_bit(HFS_BNODE_NEW, &node->flags);
386	wake_up(&node->lock_wq);
387	return node;
388
389	node_error:
390	set_bit(HFS_BNODE_ERROR, &node->flags);
391	clear_bit(HFS_BNODE_NEW, &node->flags);
392	wake_up(&node->lock_wq);
393	hfs_bnode_put(node);
394	return ERR_PTR(-EIO);
395	}
396
397	void hfs_bnode_free(struct hfs_bnode *node)
398	{
399	//int i;
400
401	//for (i = 0; i < node->tree->pages_per_bnode; i++)
402	// if (node->page[i])
403	// page_cache_release(node->page[i]);
404	kfree(node);
405	}
406
407	struct hfs_bnode hfs_bnode_create(struct hfs_btree tree, u32 num)
408	{
409	struct hfs_bnode *node;
410	struct page **pagep;
411	int i;
412
413	spin_lock(&tree->hash_lock);
414	node = hfs_bnode_findhash(tree, num);
415	spin_unlock(&tree->hash_lock);
4d4ef9ab	416	BUG_ON(node);
1da177e4 LT	417	node = __hfs_bnode_create(tree, num);
	418	if (!node)
	419	return ERR_PTR(-ENOMEM);
	420	if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
	421	hfs_bnode_put(node);
	422	return ERR_PTR(-EIO);
	423	}
	424
	425	pagep = node->page;
	426	memset(kmap(*pagep) + node->page_offset, 0,
	427	min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
	428	set_page_dirty(*pagep);
	429	kunmap(*pagep);
	430	for (i = 1; i < tree->pages_per_bnode; i++) {
	431	memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
	432	set_page_dirty(*pagep);
	433	kunmap(*pagep);
	434	}
	435	clear_bit(HFS_BNODE_NEW, &node->flags);
	436	wake_up(&node->lock_wq);
	437
	438	return node;
	439	}
	440
	441	void hfs_bnode_get(struct hfs_bnode *node)
	442	{
	443	if (node) {
	444	atomic_inc(&node->refcnt);
1da177e4 LT	445	dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
	446	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	447	}
	448	}
	449
	450	/* Dispose of resources used by a node */
	451	void hfs_bnode_put(struct hfs_bnode *node)
	452	{
	453	if (node) {
	454	struct hfs_btree *tree = node->tree;
	455	int i;
	456
	457	dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
	458	node->tree->cnid, node->this, atomic_read(&node->refcnt));
4d4ef9ab	459	BUG_ON(!atomic_read(&node->refcnt));
a5e3985f	460	if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
1da177e4	461	return;
1da177e4	462	for (i = 0; i < tree->pages_per_bnode; i++) {
74f9c9c2 RZ	463	if (!node->page[i])
74f9c9c2 RZ	464	continue;
1da177e4	465	mark_page_accessed(node->page[i]);
1da177e4 LT	466	}
	467
	468	if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
	469	hfs_bnode_unhash(node);
	470	spin_unlock(&tree->hash_lock);
	471	hfs_bmap_free(node);
	472	hfs_bnode_free(node);
	473	return;
	474	}
	475	spin_unlock(&tree->hash_lock);
	476	}
	477	}