[GitHub/mt8127/android_kernel_alcatel_ttab.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;
	/* TODO: 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;
	/* TODO: 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 ||
	    node->tree->cnid == HFSPLUS_ATTR_CNID)
		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);
	/* TODO: 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;

	hfs_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;

	hfs_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;

	hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this);
	hfs_bnode_read(node, &desc, 0, sizeof(desc));
	hfs_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);
		hfs_dbg(BNODE_MOD, " %d", key_off);
		if (i && node->type == HFS_NODE_INDEX) {
			int tmp;

			if (node->tree->attributes & HFS_TREE_VARIDXKEYS ||
					node->tree->cnid == HFSPLUS_ATTR_CNID)
				tmp = hfs_bnode_read_u16(node, key_off) + 2;
			else
				tmp = node->tree->max_key_len + 2;
			hfs_dbg_cont(BNODE_MOD, " (%d", tmp);
			hfs_bnode_read(node, &cnid, key_off + tmp, 4);
			hfs_dbg_cont(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);
			hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
		}
	}
	hfs_dbg_cont(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)
		hfs_dbg(BNODE_MOD, "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) {
		pr_err("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) {
		pr_err("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);
	hfs_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;
		}
		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;

	hfs_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) {
		pr_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);
		hfs_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;

		hfs_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_bnode_clear(node, 0,
				PAGE_CACHE_SIZE * tree->pages_per_bnode);
			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;
21f2296a	45	/* TODO: optimize later... */
1da177e4 LT	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;
21f2296a	53	/* TODO: optimize later... */
1da177e4 LT	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 \|\|
324ef39a VD	65	tree->attributes & HFS_TREE_VARIDXKEYS \|\|
324ef39a VD	66	node->tree->cnid == HFSPLUS_ATTR_CNID)
1da177e4 LT	67	key_len = hfs_bnode_read_u16(node, off) + 2;
	68	else
	69	key_len = tree->max_key_len + 2;
	70
	71	hfs_bnode_read(node, key, off, key_len);
	72	}
	73
	74	void hfs_bnode_write(struct hfs_bnode node, void buf, int off, int len)
	75	{
	76	struct page **pagep;
	77	int l;
	78
	79	off += node->page_offset;
	80	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	81	off &= ~PAGE_CACHE_MASK;
	82
	83	l = min(len, (int)PAGE_CACHE_SIZE - off);
	84	memcpy(kmap(*pagep) + off, buf, l);
	85	set_page_dirty(*pagep);
	86	kunmap(*pagep);
	87
	88	while ((len -= l) != 0) {
	89	buf += l;
	90	l = min(len, (int)PAGE_CACHE_SIZE);
	91	memcpy(kmap(*++pagep), buf, l);
	92	set_page_dirty(*pagep);
	93	kunmap(*pagep);
	94	}
	95	}
	96
	97	void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
	98	{
	99	__be16 v = cpu_to_be16(data);
21f2296a	100	/* TODO: optimize later... */
1da177e4 LT	101	hfs_bnode_write(node, &v, off, 2);
	102	}
	103
	104	void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
	105	{
	106	struct page **pagep;
	107	int l;
	108
	109	off += node->page_offset;
	110	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	111	off &= ~PAGE_CACHE_MASK;
	112
	113	l = min(len, (int)PAGE_CACHE_SIZE - off);
	114	memset(kmap(*pagep) + off, 0, l);
	115	set_page_dirty(*pagep);
	116	kunmap(*pagep);
	117
	118	while ((len -= l) != 0) {
	119	l = min(len, (int)PAGE_CACHE_SIZE);
	120	memset(kmap(*++pagep), 0, l);
	121	set_page_dirty(*pagep);
	122	kunmap(*pagep);
	123	}
	124	}
	125
	126	void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
	127	struct hfs_bnode *src_node, int src, int len)
	128	{
	129	struct hfs_btree *tree;
	130	struct page src_page, dst_page;
	131	int l;
	132
c2b3e1f7	133	hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
1da177e4 LT	134	if (!len)
	135	return;
	136	tree = src_node->tree;
	137	src += src_node->page_offset;
	138	dst += dst_node->page_offset;
	139	src_page = src_node->page + (src >> PAGE_CACHE_SHIFT);
	140	src &= ~PAGE_CACHE_MASK;
	141	dst_page = dst_node->page + (dst >> PAGE_CACHE_SHIFT);
	142	dst &= ~PAGE_CACHE_MASK;
	143
	144	if (src == dst) {
	145	l = min(len, (int)PAGE_CACHE_SIZE - src);
	146	memcpy(kmap(dst_page) + src, kmap(src_page) + src, l);
	147	kunmap(*src_page);
	148	set_page_dirty(*dst_page);
	149	kunmap(*dst_page);
	150
	151	while ((len -= l) != 0) {
	152	l = min(len, (int)PAGE_CACHE_SIZE);
	153	memcpy(kmap(++dst_page), kmap(++src_page), l);
	154	kunmap(*src_page);
	155	set_page_dirty(*dst_page);
	156	kunmap(*dst_page);
	157	}
	158	} else {
	159	void src_ptr, dst_ptr;
	160
	161	do {
	162	src_ptr = kmap(*src_page) + src;
	163	dst_ptr = kmap(*dst_page) + dst;
	164	if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) {
	165	l = PAGE_CACHE_SIZE - src;
	166	src = 0;
	167	dst += l;
	168	} else {
	169	l = PAGE_CACHE_SIZE - dst;
	170	src += l;
	171	dst = 0;
	172	}
	173	l = min(len, l);
	174	memcpy(dst_ptr, src_ptr, l);
	175	kunmap(*src_page);
	176	set_page_dirty(*dst_page);
	177	kunmap(*dst_page);
	178	if (!dst)
	179	dst_page++;
	180	else
	181	src_page++;
	182	} while ((len -= l));
	183	}
	184	}
	185
	186	void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
	187	{
	188	struct page src_page, dst_page;
	189	int l;
	190
c2b3e1f7	191	hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
1da177e4 LT	192	if (!len)
	193	return;
	194	src += node->page_offset;
	195	dst += node->page_offset;
	196	if (dst > src) {
	197	src += len - 1;
	198	src_page = node->page + (src >> PAGE_CACHE_SHIFT);
	199	src = (src & ~PAGE_CACHE_MASK) + 1;
	200	dst += len - 1;
	201	dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
	202	dst = (dst & ~PAGE_CACHE_MASK) + 1;
	203
	204	if (src == dst) {
	205	while (src < len) {
	206	memmove(kmap(dst_page), kmap(src_page), src);
	207	kunmap(*src_page);
	208	set_page_dirty(*dst_page);
	209	kunmap(*dst_page);
	210	len -= src;
	211	src = PAGE_CACHE_SIZE;
	212	src_page--;
	213	dst_page--;
	214	}
	215	src -= len;
2753cc28 AS	216	memmove(kmap(*dst_page) + src,
2753cc28 AS	217	kmap(*src_page) + src, len);
1da177e4 LT	218	kunmap(*src_page);
	219	set_page_dirty(*dst_page);
	220	kunmap(*dst_page);
	221	} else {
	222	void src_ptr, dst_ptr;
	223
	224	do {
	225	src_ptr = kmap(*src_page) + src;
	226	dst_ptr = kmap(*dst_page) + dst;
	227	if (src < dst) {
	228	l = src;
	229	src = PAGE_CACHE_SIZE;
	230	dst -= l;
	231	} else {
	232	l = dst;
	233	src -= l;
	234	dst = PAGE_CACHE_SIZE;
	235	}
	236	l = min(len, l);
	237	memmove(dst_ptr - l, src_ptr - l, l);
	238	kunmap(*src_page);
	239	set_page_dirty(*dst_page);
	240	kunmap(*dst_page);
	241	if (dst == PAGE_CACHE_SIZE)
	242	dst_page--;
	243	else
	244	src_page--;
	245	} while ((len -= l));
	246	}
	247	} else {
	248	src_page = node->page + (src >> PAGE_CACHE_SHIFT);
	249	src &= ~PAGE_CACHE_MASK;
	250	dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
	251	dst &= ~PAGE_CACHE_MASK;
	252
	253	if (src == dst) {
	254	l = min(len, (int)PAGE_CACHE_SIZE - src);
2753cc28 AS	255	memmove(kmap(*dst_page) + src,
2753cc28 AS	256	kmap(*src_page) + src, l);
1da177e4 LT	257	kunmap(*src_page);
	258	set_page_dirty(*dst_page);
	259	kunmap(*dst_page);
	260
	261	while ((len -= l) != 0) {
	262	l = min(len, (int)PAGE_CACHE_SIZE);
2753cc28 AS	263	memmove(kmap(*++dst_page),
2753cc28 AS	264	kmap(*++src_page), l);
1da177e4 LT	265	kunmap(*src_page);
	266	set_page_dirty(*dst_page);
	267	kunmap(*dst_page);
	268	}
	269	} else {
	270	void src_ptr, dst_ptr;
	271
	272	do {
	273	src_ptr = kmap(*src_page) + src;
	274	dst_ptr = kmap(*dst_page) + dst;
2753cc28 AS	275	if (PAGE_CACHE_SIZE - src <
2753cc28 AS	276	PAGE_CACHE_SIZE - dst) {
1da177e4 LT	277	l = PAGE_CACHE_SIZE - src;
	278	src = 0;
	279	dst += l;
	280	} else {
	281	l = PAGE_CACHE_SIZE - dst;
	282	src += l;
	283	dst = 0;
	284	}
	285	l = min(len, l);
	286	memmove(dst_ptr, src_ptr, l);
	287	kunmap(*src_page);
	288	set_page_dirty(*dst_page);
	289	kunmap(*dst_page);
	290	if (!dst)
	291	dst_page++;
	292	else
	293	src_page++;
	294	} while ((len -= l));
	295	}
	296	}
	297	}
	298
	299	void hfs_bnode_dump(struct hfs_bnode *node)
	300	{
	301	struct hfs_bnode_desc desc;
	302	__be32 cnid;
	303	int i, off, key_off;
	304
c2b3e1f7	305	hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this);
1da177e4	306	hfs_bnode_read(node, &desc, 0, sizeof(desc));
c2b3e1f7	307	hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n",
1da177e4 LT	308	be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
	309	desc.type, desc.height, be16_to_cpu(desc.num_recs));
	310
	311	off = node->tree->node_size - 2;
	312	for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
	313	key_off = hfs_bnode_read_u16(node, off);
c2b3e1f7	314	hfs_dbg(BNODE_MOD, " %d", key_off);
1da177e4 LT	315	if (i && node->type == HFS_NODE_INDEX) {
	316	int tmp;
	317
324ef39a VD	318	if (node->tree->attributes & HFS_TREE_VARIDXKEYS \|\|
324ef39a VD	319	node->tree->cnid == HFSPLUS_ATTR_CNID)
1da177e4 LT	320	tmp = hfs_bnode_read_u16(node, key_off) + 2;
	321	else
	322	tmp = node->tree->max_key_len + 2;
c2b3e1f7	323	hfs_dbg_cont(BNODE_MOD, " (%d", tmp);
1da177e4	324	hfs_bnode_read(node, &cnid, key_off + tmp, 4);
c2b3e1f7	325	hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid));
1da177e4 LT	326	} else if (i && node->type == HFS_NODE_LEAF) {
	327	int tmp;
	328
	329	tmp = hfs_bnode_read_u16(node, key_off);
c2b3e1f7	330	hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
1da177e4 LT	331	}
1da177e4 LT	332	}
c2b3e1f7	333	hfs_dbg_cont(BNODE_MOD, "\n");
1da177e4 LT	334	}
	335
	336	void hfs_bnode_unlink(struct hfs_bnode *node)
	337	{
	338	struct hfs_btree *tree;
	339	struct hfs_bnode *tmp;
	340	__be32 cnid;
	341
	342	tree = node->tree;
	343	if (node->prev) {
	344	tmp = hfs_bnode_find(tree, node->prev);
	345	if (IS_ERR(tmp))
	346	return;
	347	tmp->next = node->next;
	348	cnid = cpu_to_be32(tmp->next);
2753cc28 AS	349	hfs_bnode_write(tmp, &cnid,
2753cc28 AS	350	offsetof(struct hfs_bnode_desc, next), 4);
1da177e4 LT	351	hfs_bnode_put(tmp);
	352	} else if (node->type == HFS_NODE_LEAF)
	353	tree->leaf_head = node->next;
	354
	355	if (node->next) {
	356	tmp = hfs_bnode_find(tree, node->next);
	357	if (IS_ERR(tmp))
	358	return;
	359	tmp->prev = node->prev;
	360	cnid = cpu_to_be32(tmp->prev);
2753cc28 AS	361	hfs_bnode_write(tmp, &cnid,
2753cc28 AS	362	offsetof(struct hfs_bnode_desc, prev), 4);
1da177e4 LT	363	hfs_bnode_put(tmp);
	364	} else if (node->type == HFS_NODE_LEAF)
	365	tree->leaf_tail = node->prev;
	366
21f2296a	367	/* move down? */
b2837fcf	368	if (!node->prev && !node->next)
c2b3e1f7	369	hfs_dbg(BNODE_MOD, "hfs_btree_del_level\n");
1da177e4 LT	370	if (!node->parent) {
	371	tree->root = 0;
	372	tree->depth = 0;
	373	}
	374	set_bit(HFS_BNODE_DELETED, &node->flags);
	375	}
	376
	377	static inline int hfs_bnode_hash(u32 num)
	378	{
	379	num = (num >> 16) + num;
	380	num += num >> 8;
	381	return num & (NODE_HASH_SIZE - 1);
	382	}
	383
	384	struct hfs_bnode hfs_bnode_findhash(struct hfs_btree tree, u32 cnid)
	385	{
	386	struct hfs_bnode *node;
	387
	388	if (cnid >= tree->node_count) {
d6142673	389	pr_err("request for non-existent node "
2753cc28 AS	390	"%d in B*Tree\n",
2753cc28 AS	391	cnid);
1da177e4 LT	392	return NULL;
	393	}
	394
	395	for (node = tree->node_hash[hfs_bnode_hash(cnid)];
b2837fcf AS	396	node; node = node->next_hash)
b2837fcf AS	397	if (node->this == cnid)
1da177e4	398	return node;
1da177e4 LT	399	return NULL;
	400	}
	401
	402	static struct hfs_bnode __hfs_bnode_create(struct hfs_btree tree, u32 cnid)
	403	{
	404	struct super_block *sb;
	405	struct hfs_bnode node, node2;
	406	struct address_space *mapping;
	407	struct page *page;
	408	int size, block, i, hash;
	409	loff_t off;
	410
	411	if (cnid >= tree->node_count) {
d6142673	412	pr_err("request for non-existent node "
2753cc28 AS	413	"%d in B*Tree\n",
2753cc28 AS	414	cnid);
1da177e4 LT	415	return NULL;
	416	}
	417
	418	sb = tree->inode->i_sb;
	419	size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
	420	sizeof(struct page *);
f8314dc6	421	node = kzalloc(size, GFP_KERNEL);
1da177e4 LT	422	if (!node)
1da177e4 LT	423	return NULL;
1da177e4 LT	424	node->tree = tree;
	425	node->this = cnid;
	426	set_bit(HFS_BNODE_NEW, &node->flags);
	427	atomic_set(&node->refcnt, 1);
c2b3e1f7 JP	428	hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n",
c2b3e1f7 JP	429	node->tree->cnid, node->this);
1da177e4 LT	430	init_waitqueue_head(&node->lock_wq);
	431	spin_lock(&tree->hash_lock);
	432	node2 = hfs_bnode_findhash(tree, cnid);
	433	if (!node2) {
	434	hash = hfs_bnode_hash(cnid);
	435	node->next_hash = tree->node_hash[hash];
	436	tree->node_hash[hash] = node;
	437	tree->node_hash_cnt++;
	438	} else {
	439	spin_unlock(&tree->hash_lock);
	440	kfree(node);
2753cc28 AS	441	wait_event(node2->lock_wq,
2753cc28 AS	442	!test_bit(HFS_BNODE_NEW, &node2->flags));
1da177e4 LT	443	return node2;
	444	}
	445	spin_unlock(&tree->hash_lock);
	446
	447	mapping = tree->inode->i_mapping;
	448	off = (loff_t)cnid << tree->node_size_shift;
	449	block = off >> PAGE_CACHE_SHIFT;
	450	node->page_offset = off & ~PAGE_CACHE_MASK;
	451	for (i = 0; i < tree->pages_per_bnode; block++, i++) {
090d2b18	452	page = read_mapping_page(mapping, block, NULL);
1da177e4 LT	453	if (IS_ERR(page))
	454	goto fail;
	455	if (PageError(page)) {
	456	page_cache_release(page);
	457	goto fail;
	458	}
1da177e4 LT	459	node->page[i] = page;
	460	}
	461
	462	return node;
	463	fail:
	464	set_bit(HFS_BNODE_ERROR, &node->flags);
	465	return node;
	466	}
	467
	468	void hfs_bnode_unhash(struct hfs_bnode *node)
	469	{
	470	struct hfs_bnode **p;
	471
c2b3e1f7	472	hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n",
1da177e4 LT	473	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	474	for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
	475	p && p != node; p = &(*p)->next_hash)
	476	;
0bf3ba53	477	BUG_ON(!*p);
1da177e4 LT	478	*p = node->next_hash;
	479	node->tree->node_hash_cnt--;
	480	}
	481
	482	/* Load a particular node out of a tree */
	483	struct hfs_bnode hfs_bnode_find(struct hfs_btree tree, u32 num)
	484	{
	485	struct hfs_bnode *node;
	486	struct hfs_bnode_desc *desc;
	487	int i, rec_off, off, next_off;
	488	int entry_size, key_size;
	489
	490	spin_lock(&tree->hash_lock);
	491	node = hfs_bnode_findhash(tree, num);
	492	if (node) {
	493	hfs_bnode_get(node);
	494	spin_unlock(&tree->hash_lock);
2753cc28 AS	495	wait_event(node->lock_wq,
2753cc28 AS	496	!test_bit(HFS_BNODE_NEW, &node->flags));
1da177e4 LT	497	if (test_bit(HFS_BNODE_ERROR, &node->flags))
	498	goto node_error;
	499	return node;
	500	}
	501	spin_unlock(&tree->hash_lock);
	502	node = __hfs_bnode_create(tree, num);
	503	if (!node)
	504	return ERR_PTR(-ENOMEM);
	505	if (test_bit(HFS_BNODE_ERROR, &node->flags))
	506	goto node_error;
	507	if (!test_bit(HFS_BNODE_NEW, &node->flags))
	508	return node;
	509
2753cc28 AS	510	desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) +
2753cc28 AS	511	node->page_offset);
1da177e4 LT	512	node->prev = be32_to_cpu(desc->prev);
	513	node->next = be32_to_cpu(desc->next);
	514	node->num_recs = be16_to_cpu(desc->num_recs);
	515	node->type = desc->type;
	516	node->height = desc->height;
	517	kunmap(node->page[0]);
	518
	519	switch (node->type) {
	520	case HFS_NODE_HEADER:
	521	case HFS_NODE_MAP:
	522	if (node->height != 0)
	523	goto node_error;
	524	break;
	525	case HFS_NODE_LEAF:
	526	if (node->height != 1)
	527	goto node_error;
	528	break;
	529	case HFS_NODE_INDEX:
	530	if (node->height <= 1 \|\| node->height > tree->depth)
	531	goto node_error;
	532	break;
	533	default:
	534	goto node_error;
	535	}
	536
	537	rec_off = tree->node_size - 2;
	538	off = hfs_bnode_read_u16(node, rec_off);
	539	if (off != sizeof(struct hfs_bnode_desc))
	540	goto node_error;
	541	for (i = 1; i <= node->num_recs; off = next_off, i++) {
	542	rec_off -= 2;
	543	next_off = hfs_bnode_read_u16(node, rec_off);
	544	if (next_off <= off \|\|
	545	next_off > tree->node_size \|\|
	546	next_off & 1)
	547	goto node_error;
	548	entry_size = next_off - off;
	549	if (node->type != HFS_NODE_INDEX &&
	550	node->type != HFS_NODE_LEAF)
	551	continue;
	552	key_size = hfs_bnode_read_u16(node, off) + 2;
	553	if (key_size >= entry_size \|\| key_size & 1)
	554	goto node_error;
	555	}
	556	clear_bit(HFS_BNODE_NEW, &node->flags);
	557	wake_up(&node->lock_wq);
	558	return node;
	559
	560	node_error:
	561	set_bit(HFS_BNODE_ERROR, &node->flags);
	562	clear_bit(HFS_BNODE_NEW, &node->flags);
	563	wake_up(&node->lock_wq);
	564	hfs_bnode_put(node);
	565	return ERR_PTR(-EIO);
	566	}
	567
	568	void hfs_bnode_free(struct hfs_bnode *node)
	569	{
21f2296a	570	int i;
1da177e4	571
21f2296a AS	572	for (i = 0; i < node->tree->pages_per_bnode; i++)
	573	if (node->page[i])
	574	page_cache_release(node->page[i]);
1da177e4 LT	575	kfree(node);
	576	}
	577
	578	struct hfs_bnode hfs_bnode_create(struct hfs_btree tree, u32 num)
	579	{
	580	struct hfs_bnode *node;
	581	struct page **pagep;
	582	int i;
	583
	584	spin_lock(&tree->hash_lock);
	585	node = hfs_bnode_findhash(tree, num);
	586	spin_unlock(&tree->hash_lock);
	587	if (node) {
d6142673	588	pr_crit("new node %u already hashed?\n", num);
634725a9 RZ	589	WARN_ON(1);
634725a9 RZ	590	return node;
1da177e4 LT	591	}
	592	node = __hfs_bnode_create(tree, num);
	593	if (!node)
	594	return ERR_PTR(-ENOMEM);
	595	if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
	596	hfs_bnode_put(node);
	597	return ERR_PTR(-EIO);
	598	}
	599
	600	pagep = node->page;
	601	memset(kmap(*pagep) + node->page_offset, 0,
	602	min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
	603	set_page_dirty(*pagep);
	604	kunmap(*pagep);
	605	for (i = 1; i < tree->pages_per_bnode; i++) {
	606	memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
	607	set_page_dirty(*pagep);
	608	kunmap(*pagep);
	609	}
	610	clear_bit(HFS_BNODE_NEW, &node->flags);
	611	wake_up(&node->lock_wq);
	612
	613	return node;
	614	}
	615
	616	void hfs_bnode_get(struct hfs_bnode *node)
	617	{
	618	if (node) {
	619	atomic_inc(&node->refcnt);
c2b3e1f7	620	hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n",
2753cc28 AS	621	node->tree->cnid, node->this,
2753cc28 AS	622	atomic_read(&node->refcnt));
1da177e4 LT	623	}
	624	}
	625
	626	/* Dispose of resources used by a node */
	627	void hfs_bnode_put(struct hfs_bnode *node)
	628	{
	629	if (node) {
	630	struct hfs_btree *tree = node->tree;
	631	int i;
	632
c2b3e1f7	633	hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n",
2753cc28 AS	634	node->tree->cnid, node->this,
2753cc28 AS	635	atomic_read(&node->refcnt));
0bf3ba53	636	BUG_ON(!atomic_read(&node->refcnt));
a5e3985f	637	if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
1da177e4	638	return;
1da177e4	639	for (i = 0; i < tree->pages_per_bnode; i++) {
74f9c9c2 RZ	640	if (!node->page[i])
74f9c9c2 RZ	641	continue;
1da177e4	642	mark_page_accessed(node->page[i]);
1da177e4 LT	643	}
	644
	645	if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
	646	hfs_bnode_unhash(node);
	647	spin_unlock(&tree->hash_lock);
899bed05 VD	648	hfs_bnode_clear(node, 0,
899bed05 VD	649	PAGE_CACHE_SIZE * tree->pages_per_bnode);
1da177e4 LT	650	hfs_bmap_free(node);
	651	hfs_bnode_free(node);
	652	return;
	653	}
	654	spin_unlock(&tree->hash_lock);
	655	}
	656	}
	657