[net-next-2.6.git] / fs / hfsplus / bnode.c

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

#include <linux/string.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/fs.h>
#include <linux/swap.h>

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

/* Copy a specified range of bytes from the raw data of a node */
void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len)
{
	struct page **pagep;
	int l;

	off += node->page_offset;
	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	off &= ~PAGE_CACHE_MASK;

	l = min(len, (int)PAGE_CACHE_SIZE - off);
	memcpy(buf, kmap(*pagep) + off, l);
	kunmap(*pagep);

	while ((len -= l) != 0) {
		buf += l;
		l = min(len, (int)PAGE_CACHE_SIZE);
		memcpy(buf, kmap(*++pagep), l);
		kunmap(*pagep);
	}
}

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_u16(node, off) + 2;
	else
		key_len = tree->max_key_len + 2;

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

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

	off += node->page_offset;
	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	off &= ~PAGE_CACHE_MASK;

	l = min(len, (int)PAGE_CACHE_SIZE - off);
	memcpy(kmap(*pagep) + off, buf, l);
	set_page_dirty(*pagep);
	kunmap(*pagep);

	while ((len -= l) != 0) {
		buf += l;
		l = min(len, (int)PAGE_CACHE_SIZE);
		memcpy(kmap(*++pagep), buf, l);
		set_page_dirty(*pagep);
		kunmap(*pagep);
	}
}

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_clear(struct hfs_bnode *node, int off, int len)
{
	struct page **pagep;
	int l;

	off += node->page_offset;
	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	off &= ~PAGE_CACHE_MASK;

	l = min(len, (int)PAGE_CACHE_SIZE - off);
	memset(kmap(*pagep) + off, 0, l);
	set_page_dirty(*pagep);
	kunmap(*pagep);

	while ((len -= l) != 0) {
		l = min(len, (int)PAGE_CACHE_SIZE);
		memset(kmap(*++pagep), 0, l);
		set_page_dirty(*pagep);
		kunmap(*pagep);
	}
}

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;
	int l;

	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 + (src >> PAGE_CACHE_SHIFT);
	src &= ~PAGE_CACHE_MASK;
	dst_page = dst_node->page + (dst >> PAGE_CACHE_SHIFT);
	dst &= ~PAGE_CACHE_MASK;

	if (src == dst) {
		l = min(len, (int)PAGE_CACHE_SIZE - src);
		memcpy(kmap(*dst_page) + src, kmap(*src_page) + src, l);
		kunmap(*src_page);
		set_page_dirty(*dst_page);
		kunmap(*dst_page);

		while ((len -= l) != 0) {
			l = min(len, (int)PAGE_CACHE_SIZE);
			memcpy(kmap(*++dst_page), kmap(*++src_page), l);
			kunmap(*src_page);
			set_page_dirty(*dst_page);
			kunmap(*dst_page);
		}
	} else {
		void *src_ptr, *dst_ptr;

		do {
			src_ptr = kmap(*src_page) + src;
			dst_ptr = kmap(*dst_page) + dst;
			if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) {
				l = PAGE_CACHE_SIZE - src;
				src = 0;
				dst += l;
			} else {
				l = PAGE_CACHE_SIZE - dst;
				src += l;
				dst = 0;
			}
			l = min(len, l);
			memcpy(dst_ptr, src_ptr, l);
			kunmap(*src_page);
			set_page_dirty(*dst_page);
			kunmap(*dst_page);
			if (!dst)
				dst_page++;
			else
				src_page++;
		} while ((len -= l));
	}
}

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

	dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
	if (!len)
		return;
	src += node->page_offset;
	dst += node->page_offset;
	if (dst > src) {
		src += len - 1;
		src_page = node->page + (src >> PAGE_CACHE_SHIFT);
		src = (src & ~PAGE_CACHE_MASK) + 1;
		dst += len - 1;
		dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
		dst = (dst & ~PAGE_CACHE_MASK) + 1;

		if (src == dst) {
			while (src < len) {
				memmove(kmap(*dst_page), kmap(*src_page), src);
				kunmap(*src_page);
				set_page_dirty(*dst_page);
				kunmap(*dst_page);
				len -= src;
				src = PAGE_CACHE_SIZE;
				src_page--;
				dst_page--;
			}
			src -= len;
			memmove(kmap(*dst_page) + src, kmap(*src_page) + src, len);
			kunmap(*src_page);
			set_page_dirty(*dst_page);
			kunmap(*dst_page);
		} else {
			void *src_ptr, *dst_ptr;

			do {
				src_ptr = kmap(*src_page) + src;
				dst_ptr = kmap(*dst_page) + dst;
				if (src < dst) {
					l = src;
					src = PAGE_CACHE_SIZE;
					dst -= l;
				} else {
					l = dst;
					src -= l;
					dst = PAGE_CACHE_SIZE;
				}
				l = min(len, l);
				memmove(dst_ptr - l, src_ptr - l, l);
				kunmap(*src_page);
				set_page_dirty(*dst_page);
				kunmap(*dst_page);
				if (dst == PAGE_CACHE_SIZE)
					dst_page--;
				else
					src_page--;
			} while ((len -= l));
		}
	} else {
		src_page = node->page + (src >> PAGE_CACHE_SHIFT);
		src &= ~PAGE_CACHE_MASK;
		dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
		dst &= ~PAGE_CACHE_MASK;

		if (src == dst) {
			l = min(len, (int)PAGE_CACHE_SIZE - src);
			memmove(kmap(*dst_page) + src, kmap(*src_page) + src, l);
			kunmap(*src_page);
			set_page_dirty(*dst_page);
			kunmap(*dst_page);

			while ((len -= l) != 0) {
				l = min(len, (int)PAGE_CACHE_SIZE);
				memmove(kmap(*++dst_page), kmap(*++src_page), l);
				kunmap(*src_page);
				set_page_dirty(*dst_page);
				kunmap(*dst_page);
			}
		} else {
			void *src_ptr, *dst_ptr;

			do {
				src_ptr = kmap(*src_page) + src;
				dst_ptr = kmap(*dst_page) + dst;
				if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) {
					l = PAGE_CACHE_SIZE - src;
					src = 0;
					dst += l;
				} else {
					l = PAGE_CACHE_SIZE - dst;
					src += l;
					dst = 0;
				}
				l = min(len, l);
				memmove(dst_ptr, src_ptr, l);
				kunmap(*src_page);
				set_page_dirty(*dst_page);
				kunmap(*dst_page);
				if (!dst)
					dst_page++;
				else
					src_page++;
			} while ((len -= l));
		}
	}
}

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_u16(node, key_off) + 2;
			else
				tmp = node->tree->max_key_len + 2;
			dprint(DBG_BNODE_MOD, " (%d", tmp);
			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_u16(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_shift;
	block = off >> PAGE_CACHE_SHIFT;
	node->page_offset = off & ~PAGE_CACHE_MASK;
	for (i = 0; i < tree->pages_per_bnode; block++, 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_u16(node, off) + 2;
		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);
	if (node) {
		printk(KERN_CRIT "new node %u already hashed?\n", num);
		WARN_ON(1);
		return 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/hfsplus/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/string.h>
	12	#include <linux/slab.h>
	13	#include <linux/pagemap.h>
	14	#include <linux/fs.h>
	15	#include <linux/swap.h>
1da177e4 LT	16
	17	#include "hfsplus_fs.h"
	18	#include "hfsplus_raw.h"
	19
1da177e4 LT	20	/* Copy a specified range of bytes from the raw data of a node */
	21	void hfs_bnode_read(struct hfs_bnode node, void buf, int off, int len)
	22	{
	23	struct page **pagep;
	24	int l;
	25
	26	off += node->page_offset;
	27	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	28	off &= ~PAGE_CACHE_MASK;
	29
	30	l = min(len, (int)PAGE_CACHE_SIZE - off);
	31	memcpy(buf, kmap(*pagep) + off, l);
	32	kunmap(*pagep);
	33
	34	while ((len -= l) != 0) {
	35	buf += l;
	36	l = min(len, (int)PAGE_CACHE_SIZE);
	37	memcpy(buf, kmap(*++pagep), l);
	38	kunmap(*pagep);
	39	}
	40	}
	41
	42	u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
	43	{
	44	__be16 data;
	45	// optimize later...
	46	hfs_bnode_read(node, &data, off, 2);
	47	return be16_to_cpu(data);
	48	}
	49
	50	u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
	51	{
	52	u8 data;
	53	// optimize later...
	54	hfs_bnode_read(node, &data, off, 1);
	55	return data;
	56	}
	57
	58	void hfs_bnode_read_key(struct hfs_bnode node, void key, int off)
	59	{
	60	struct hfs_btree *tree;
	61	int key_len;
	62
	63	tree = node->tree;
	64	if (node->type == HFS_NODE_LEAF \|\|
	65	tree->attributes & HFS_TREE_VARIDXKEYS)
	66	key_len = hfs_bnode_read_u16(node, off) + 2;
	67	else
	68	key_len = tree->max_key_len + 2;
	69
	70	hfs_bnode_read(node, key, off, key_len);
	71	}
	72
	73	void hfs_bnode_write(struct hfs_bnode node, void buf, int off, int len)
	74	{
	75	struct page **pagep;
	76	int l;
	77
	78	off += node->page_offset;
	79	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	80	off &= ~PAGE_CACHE_MASK;
	81
	82	l = min(len, (int)PAGE_CACHE_SIZE - off);
	83	memcpy(kmap(*pagep) + off, buf, l);
84	set_page_dirty(*pagep);
85	kunmap(*pagep);
86
87	while ((len -= l) != 0) {
88	buf += l;
89	l = min(len, (int)PAGE_CACHE_SIZE);
90	memcpy(kmap(*++pagep), buf, l);
91	set_page_dirty(*pagep);
92	kunmap(*pagep);
93	}
94	}
95
96	void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
97	{
98	__be16 v = cpu_to_be16(data);
99	// optimize later...
100	hfs_bnode_write(node, &v, off, 2);
101	}
102
103	void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
104	{
105	struct page **pagep;
106	int l;
107
108	off += node->page_offset;
109	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
110	off &= ~PAGE_CACHE_MASK;
111
112	l = min(len, (int)PAGE_CACHE_SIZE - off);
113	memset(kmap(*pagep) + off, 0, l);
114	set_page_dirty(*pagep);
115	kunmap(*pagep);
116
117	while ((len -= l) != 0) {
118	l = min(len, (int)PAGE_CACHE_SIZE);
119	memset(kmap(*++pagep), 0, l);
120	set_page_dirty(*pagep);
121	kunmap(*pagep);
122	}
123	}
124
125	void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
126	struct hfs_bnode *src_node, int src, int len)
127	{
128	struct hfs_btree *tree;
129	struct page src_page, dst_page;
130	int l;
131
132	dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
133	if (!len)
134	return;
135	tree = src_node->tree;
136	src += src_node->page_offset;
137	dst += dst_node->page_offset;
138	src_page = src_node->page + (src >> PAGE_CACHE_SHIFT);
139	src &= ~PAGE_CACHE_MASK;
140	dst_page = dst_node->page + (dst >> PAGE_CACHE_SHIFT);
141	dst &= ~PAGE_CACHE_MASK;
142
143	if (src == dst) {
144	l = min(len, (int)PAGE_CACHE_SIZE - src);
145	memcpy(kmap(dst_page) + src, kmap(src_page) + src, l);
146	kunmap(*src_page);
147	set_page_dirty(*dst_page);
148	kunmap(*dst_page);
149
150	while ((len -= l) != 0) {
151	l = min(len, (int)PAGE_CACHE_SIZE);
152	memcpy(kmap(++dst_page), kmap(++src_page), l);
153	kunmap(*src_page);
154	set_page_dirty(*dst_page);
155	kunmap(*dst_page);
156	}
157	} else {
158	void src_ptr, dst_ptr;
159
160	do {
161	src_ptr = kmap(*src_page) + src;
162	dst_ptr = kmap(*dst_page) + dst;
163	if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) {
164	l = PAGE_CACHE_SIZE - src;
165	src = 0;
166	dst += l;
167	} else {
168	l = PAGE_CACHE_SIZE - dst;
169	src += l;
170	dst = 0;
171	}
172	l = min(len, l);
173	memcpy(dst_ptr, src_ptr, l);
174	kunmap(*src_page);
175	set_page_dirty(*dst_page);
176	kunmap(*dst_page);
177	if (!dst)
178	dst_page++;
179	else
180	src_page++;
181	} while ((len -= l));
182	}
183	}
184
185	void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
186	{
187	struct page src_page, dst_page;
188	int l;
189
190	dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
191	if (!len)
192	return;
193	src += node->page_offset;
194	dst += node->page_offset;
195	if (dst > src) {
196	src += len - 1;
197	src_page = node->page + (src >> PAGE_CACHE_SHIFT);
198	src = (src & ~PAGE_CACHE_MASK) + 1;
199	dst += len - 1;
200	dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
201	dst = (dst & ~PAGE_CACHE_MASK) + 1;
202
203	if (src == dst) {
204	while (src < len) {
205	memmove(kmap(dst_page), kmap(src_page), src);
206	kunmap(*src_page);
207	set_page_dirty(*dst_page);
208	kunmap(*dst_page);
209	len -= src;
210	src = PAGE_CACHE_SIZE;
211	src_page--;
212	dst_page--;
213	}
214	src -= len;
215	memmove(kmap(dst_page) + src, kmap(src_page) + src, len);
216	kunmap(*src_page);
217	set_page_dirty(*dst_page);
218	kunmap(*dst_page);
219	} else {
220	void src_ptr, dst_ptr;
221
222	do {
223	src_ptr = kmap(*src_page) + src;
224	dst_ptr = kmap(*dst_page) + dst;
225	if (src < dst) {
226	l = src;
227	src = PAGE_CACHE_SIZE;
228	dst -= l;
229	} else {
230	l = dst;
231	src -= l;
232	dst = PAGE_CACHE_SIZE;
233	}
234	l = min(len, l);
235	memmove(dst_ptr - l, src_ptr - l, l);
236	kunmap(*src_page);
237	set_page_dirty(*dst_page);
238	kunmap(*dst_page);
239	if (dst == PAGE_CACHE_SIZE)
240	dst_page--;
241	else
242	src_page--;
243	} while ((len -= l));
244	}
245	} else {
246	src_page = node->page + (src >> PAGE_CACHE_SHIFT);
247	src &= ~PAGE_CACHE_MASK;
248	dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
249	dst &= ~PAGE_CACHE_MASK;
250
251	if (src == dst) {
252	l = min(len, (int)PAGE_CACHE_SIZE - src);
253	memmove(kmap(dst_page) + src, kmap(src_page) + src, l);
254	kunmap(*src_page);
255	set_page_dirty(*dst_page);
256	kunmap(*dst_page);
257
258	while ((len -= l) != 0) {
259	l = min(len, (int)PAGE_CACHE_SIZE);
260	memmove(kmap(++dst_page), kmap(++src_page), l);
261	kunmap(*src_page);
262	set_page_dirty(*dst_page);
263	kunmap(*dst_page);
264	}
265	} else {
266	void src_ptr, dst_ptr;
267
268	do {
269	src_ptr = kmap(*src_page) + src;
270	dst_ptr = kmap(*dst_page) + dst;
271	if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) {
272	l = PAGE_CACHE_SIZE - src;
273	src = 0;
274	dst += l;
275	} else {
276	l = PAGE_CACHE_SIZE - dst;
277	src += l;
278	dst = 0;
279	}
280	l = min(len, l);
281	memmove(dst_ptr, src_ptr, l);
282	kunmap(*src_page);
283	set_page_dirty(*dst_page);
284	kunmap(*dst_page);
285	if (!dst)
286	dst_page++;
287	else
288	src_page++;
289	} while ((len -= l));
290	}
291	}
292	}
293
294	void hfs_bnode_dump(struct hfs_bnode *node)
295	{
296	struct hfs_bnode_desc desc;
297	__be32 cnid;
298	int i, off, key_off;
299
300	dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
301	hfs_bnode_read(node, &desc, 0, sizeof(desc));
302	dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
303	be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
304	desc.type, desc.height, be16_to_cpu(desc.num_recs));
305
306	off = node->tree->node_size - 2;
307	for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
308	key_off = hfs_bnode_read_u16(node, off);
309	dprint(DBG_BNODE_MOD, " %d", key_off);
310	if (i && node->type == HFS_NODE_INDEX) {
311	int tmp;
312
313	if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
314	tmp = hfs_bnode_read_u16(node, key_off) + 2;
315	else
316	tmp = node->tree->max_key_len + 2;
317	dprint(DBG_BNODE_MOD, " (%d", tmp);
318	hfs_bnode_read(node, &cnid, key_off + tmp, 4);
319	dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
320	} else if (i && node->type == HFS_NODE_LEAF) {
321	int tmp;
322
323	tmp = hfs_bnode_read_u16(node, key_off);
324	dprint(DBG_BNODE_MOD, " (%d)", tmp);
325	}
326	}
327	dprint(DBG_BNODE_MOD, "\n");
328	}
329
330	void hfs_bnode_unlink(struct hfs_bnode *node)
331	{
332	struct hfs_btree *tree;
333	struct hfs_bnode *tmp;
334	__be32 cnid;
335
336	tree = node->tree;
337	if (node->prev) {
338	tmp = hfs_bnode_find(tree, node->prev);
339	if (IS_ERR(tmp))
340	return;
341	tmp->next = node->next;
342	cnid = cpu_to_be32(tmp->next);
343	hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
344	hfs_bnode_put(tmp);
345	} else if (node->type == HFS_NODE_LEAF)
346	tree->leaf_head = node->next;
347
348	if (node->next) {
349	tmp = hfs_bnode_find(tree, node->next);
350	if (IS_ERR(tmp))
351	return;
352	tmp->prev = node->prev;
353	cnid = cpu_to_be32(tmp->prev);
354	hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
355	hfs_bnode_put(tmp);
356	} else if (node->type == HFS_NODE_LEAF)
357	tree->leaf_tail = node->prev;
358
359	// move down?
360	if (!node->prev && !node->next) {
634725a9	361	printk(KERN_DEBUG "hfs_btree_del_level\n");
1da177e4 LT	362	}
	363	if (!node->parent) {
	364	tree->root = 0;
	365	tree->depth = 0;
	366	}
	367	set_bit(HFS_BNODE_DELETED, &node->flags);
	368	}
	369
	370	static inline int hfs_bnode_hash(u32 num)
	371	{
	372	num = (num >> 16) + num;
	373	num += num >> 8;
	374	return num & (NODE_HASH_SIZE - 1);
	375	}
	376
	377	struct hfs_bnode hfs_bnode_findhash(struct hfs_btree tree, u32 cnid)
	378	{
	379	struct hfs_bnode *node;
	380
	381	if (cnid >= tree->node_count) {
634725a9	382	printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
1da177e4 LT	383	return NULL;
	384	}
	385
	386	for (node = tree->node_hash[hfs_bnode_hash(cnid)];
	387	node; node = node->next_hash) {
	388	if (node->this == cnid) {
	389	return node;
	390	}
	391	}
	392	return NULL;
	393	}
	394
	395	static struct hfs_bnode __hfs_bnode_create(struct hfs_btree tree, u32 cnid)
	396	{
	397	struct super_block *sb;
	398	struct hfs_bnode node, node2;
	399	struct address_space *mapping;
	400	struct page *page;
	401	int size, block, i, hash;
	402	loff_t off;
	403
	404	if (cnid >= tree->node_count) {
634725a9	405	printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
1da177e4 LT	406	return NULL;
	407	}
	408
	409	sb = tree->inode->i_sb;
	410	size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
	411	sizeof(struct page *);
f8314dc6	412	node = kzalloc(size, GFP_KERNEL);
1da177e4 LT	413	if (!node)
1da177e4 LT	414	return NULL;
1da177e4 LT	415	node->tree = tree;
	416	node->this = cnid;
	417	set_bit(HFS_BNODE_NEW, &node->flags);
	418	atomic_set(&node->refcnt, 1);
	419	dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
	420	node->tree->cnid, node->this);
	421	init_waitqueue_head(&node->lock_wq);
	422	spin_lock(&tree->hash_lock);
	423	node2 = hfs_bnode_findhash(tree, cnid);
	424	if (!node2) {
	425	hash = hfs_bnode_hash(cnid);
	426	node->next_hash = tree->node_hash[hash];
	427	tree->node_hash[hash] = node;
	428	tree->node_hash_cnt++;
	429	} else {
	430	spin_unlock(&tree->hash_lock);
	431	kfree(node);
	432	wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
	433	return node2;
	434	}
	435	spin_unlock(&tree->hash_lock);
	436
	437	mapping = tree->inode->i_mapping;
	438	off = (loff_t)cnid << tree->node_size_shift;
	439	block = off >> PAGE_CACHE_SHIFT;
	440	node->page_offset = off & ~PAGE_CACHE_MASK;
	441	for (i = 0; i < tree->pages_per_bnode; block++, i++) {
090d2b18	442	page = read_mapping_page(mapping, block, NULL);
1da177e4 LT	443	if (IS_ERR(page))
	444	goto fail;
	445	if (PageError(page)) {
	446	page_cache_release(page);
	447	goto fail;
	448	}
1da177e4	449	page_cache_release(page);
1da177e4 LT	450	node->page[i] = page;
	451	}
	452
	453	return node;
	454	fail:
	455	set_bit(HFS_BNODE_ERROR, &node->flags);
	456	return node;
	457	}
	458
	459	void hfs_bnode_unhash(struct hfs_bnode *node)
	460	{
	461	struct hfs_bnode **p;
	462
	463	dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
	464	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	465	for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
	466	p && p != node; p = &(*p)->next_hash)
	467	;
0bf3ba53	468	BUG_ON(!*p);
1da177e4 LT	469	*p = node->next_hash;
	470	node->tree->node_hash_cnt--;
	471	}
	472
	473	/* Load a particular node out of a tree */
	474	struct hfs_bnode hfs_bnode_find(struct hfs_btree tree, u32 num)
	475	{
	476	struct hfs_bnode *node;
	477	struct hfs_bnode_desc *desc;
	478	int i, rec_off, off, next_off;
	479	int entry_size, key_size;
	480
	481	spin_lock(&tree->hash_lock);
	482	node = hfs_bnode_findhash(tree, num);
	483	if (node) {
	484	hfs_bnode_get(node);
	485	spin_unlock(&tree->hash_lock);
	486	wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
	487	if (test_bit(HFS_BNODE_ERROR, &node->flags))
	488	goto node_error;
	489	return node;
	490	}
	491	spin_unlock(&tree->hash_lock);
	492	node = __hfs_bnode_create(tree, num);
	493	if (!node)
	494	return ERR_PTR(-ENOMEM);
	495	if (test_bit(HFS_BNODE_ERROR, &node->flags))
	496	goto node_error;
	497	if (!test_bit(HFS_BNODE_NEW, &node->flags))
	498	return node;
	499
	500	desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
	501	node->prev = be32_to_cpu(desc->prev);
	502	node->next = be32_to_cpu(desc->next);
	503	node->num_recs = be16_to_cpu(desc->num_recs);
	504	node->type = desc->type;
	505	node->height = desc->height;
	506	kunmap(node->page[0]);
	507
	508	switch (node->type) {
	509	case HFS_NODE_HEADER:
	510	case HFS_NODE_MAP:
	511	if (node->height != 0)
	512	goto node_error;
	513	break;
	514	case HFS_NODE_LEAF:
	515	if (node->height != 1)
	516	goto node_error;
	517	break;
	518	case HFS_NODE_INDEX:
	519	if (node->height <= 1 \|\| node->height > tree->depth)
	520	goto node_error;
	521	break;
	522	default:
	523	goto node_error;
	524	}
	525
	526	rec_off = tree->node_size - 2;
	527	off = hfs_bnode_read_u16(node, rec_off);
	528	if (off != sizeof(struct hfs_bnode_desc))
	529	goto node_error;
	530	for (i = 1; i <= node->num_recs; off = next_off, i++) {
	531	rec_off -= 2;
	532	next_off = hfs_bnode_read_u16(node, rec_off);
533	if (next_off <= off \|\|
534	next_off > tree->node_size \|\|
535	next_off & 1)
536	goto node_error;
537	entry_size = next_off - off;
538	if (node->type != HFS_NODE_INDEX &&
539	node->type != HFS_NODE_LEAF)
540	continue;
541	key_size = hfs_bnode_read_u16(node, off) + 2;
542	if (key_size >= entry_size \|\| key_size & 1)
543	goto node_error;
544	}
545	clear_bit(HFS_BNODE_NEW, &node->flags);
546	wake_up(&node->lock_wq);
547	return node;
548
549	node_error:
550	set_bit(HFS_BNODE_ERROR, &node->flags);
551	clear_bit(HFS_BNODE_NEW, &node->flags);
552	wake_up(&node->lock_wq);
553	hfs_bnode_put(node);
554	return ERR_PTR(-EIO);
555	}
556
557	void hfs_bnode_free(struct hfs_bnode *node)
558	{
559	//int i;
560
561	//for (i = 0; i < node->tree->pages_per_bnode; i++)
562	// if (node->page[i])
563	// page_cache_release(node->page[i]);
564	kfree(node);
565	}
566
567	struct hfs_bnode hfs_bnode_create(struct hfs_btree tree, u32 num)
568	{
569	struct hfs_bnode *node;
570	struct page **pagep;
571	int i;
572
573	spin_lock(&tree->hash_lock);
574	node = hfs_bnode_findhash(tree, num);
575	spin_unlock(&tree->hash_lock);
576	if (node) {
634725a9 RZ	577	printk(KERN_CRIT "new node %u already hashed?\n", num);
	578	WARN_ON(1);
	579	return node;
1da177e4 LT	580	}
	581	node = __hfs_bnode_create(tree, num);
	582	if (!node)
	583	return ERR_PTR(-ENOMEM);
	584	if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
	585	hfs_bnode_put(node);
	586	return ERR_PTR(-EIO);
	587	}
	588
	589	pagep = node->page;
	590	memset(kmap(*pagep) + node->page_offset, 0,
	591	min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
	592	set_page_dirty(*pagep);
	593	kunmap(*pagep);
	594	for (i = 1; i < tree->pages_per_bnode; i++) {
	595	memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
	596	set_page_dirty(*pagep);
	597	kunmap(*pagep);
	598	}
	599	clear_bit(HFS_BNODE_NEW, &node->flags);
	600	wake_up(&node->lock_wq);
	601
	602	return node;
	603	}
	604
	605	void hfs_bnode_get(struct hfs_bnode *node)
	606	{
	607	if (node) {
	608	atomic_inc(&node->refcnt);
1da177e4 LT	609	dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
	610	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	611	}
	612	}
	613
	614	/* Dispose of resources used by a node */
	615	void hfs_bnode_put(struct hfs_bnode *node)
	616	{
	617	if (node) {
	618	struct hfs_btree *tree = node->tree;
	619	int i;
	620
	621	dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
	622	node->tree->cnid, node->this, atomic_read(&node->refcnt));
0bf3ba53	623	BUG_ON(!atomic_read(&node->refcnt));
a5e3985f	624	if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
1da177e4	625	return;
1da177e4	626	for (i = 0; i < tree->pages_per_bnode; i++) {
74f9c9c2 RZ	627	if (!node->page[i])
74f9c9c2 RZ	628	continue;
1da177e4	629	mark_page_accessed(node->page[i]);
1da177e4 LT	630	}
	631
	632	if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
	633	hfs_bnode_unhash(node);
	634	spin_unlock(&tree->hash_lock);
	635	hfs_bmap_free(node);
	636	hfs_bnode_free(node);
	637	return;
	638	}
	639	spin_unlock(&tree->hash_lock);
	640	}
	641	}
	642