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

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

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

#include "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 page *page;
	unsigned int size;

	tree = kmalloc(sizeof(*tree), GFP_KERNEL);
	if (!tree)
		return NULL;
	memset(tree, 0, sizeof(*tree));

	init_MUTEX(&tree->tree_lock);
	spin_lock_init(&tree->hash_lock);
	/* Set the correct compare function */
	tree->sb = sb;
	tree->cnid = id;
	if (id == HFSPLUS_EXT_CNID) {
		tree->keycmp = hfsplus_ext_cmp_key;
	} else if (id == HFSPLUS_CAT_CNID) {
		tree->keycmp = hfsplus_cat_cmp_key;
	} else {
		printk(KERN_ERR "hfs: unknown B*Tree requested\n");
		goto free_tree;
	}
	tree->inode = iget(sb, id);
	if (!tree->inode)
		goto free_tree;

	mapping = tree->inode->i_mapping;
	page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL);
	if (IS_ERR(page))
		goto free_tree;

	/* 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);

	size = tree->node_size;
	if (!size || size & (size - 1))
		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:
	tree->inode->i_mapping->a_ops = &hfsplus_aops;
	page_cache_release(page);
 free_tree:
	iput(tree->inode);
	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;
	u16 off, len;
	u8 *data, byte, m;
	int i;

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

		res = hfsplus_file_extend(inode);
		if (res)
			return ERR_PTR(res);
		HFSPLUS_I(inode).phys_size = inode->i_size =
				(loff_t)HFSPLUS_I(inode).alloc_blocks <<
				HFSPLUS_SB(tree->sb).alloc_blksz_shift;
		HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).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, &off);

	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, &off);
		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);
	if (!node->this)
		BUG();
	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>
	13
	14	#include "hfsplus_fs.h"
	15	#include "hfsplus_raw.h"
	16
	17
	18	/* Get a reference to a BTree and do some initial checks /
	19	struct hfs_btree hfs_btree_open(struct super_block sb, u32 id)
	20	{
	21	struct hfs_btree *tree;
	22	struct hfs_btree_header_rec *head;
	23	struct address_space *mapping;
	24	struct page *page;
	25	unsigned int size;
	26
	27	tree = kmalloc(sizeof(*tree), GFP_KERNEL);
	28	if (!tree)
	29	return NULL;
	30	memset(tree, 0, sizeof(*tree));
	31
	32	init_MUTEX(&tree->tree_lock);
	33	spin_lock_init(&tree->hash_lock);
	34	/* Set the correct compare function */
	35	tree->sb = sb;
	36	tree->cnid = id;
	37	if (id == HFSPLUS_EXT_CNID) {
	38	tree->keycmp = hfsplus_ext_cmp_key;
	39	} else if (id == HFSPLUS_CAT_CNID) {
	40	tree->keycmp = hfsplus_cat_cmp_key;
	41	} else {
634725a9	42	printk(KERN_ERR "hfs: unknown B*Tree requested\n");
1da177e4 LT	43	goto free_tree;
	44	}
	45	tree->inode = iget(sb, id);
	46	if (!tree->inode)
	47	goto free_tree;
	48
	49	mapping = tree->inode->i_mapping;
	50	page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL);
	51	if (IS_ERR(page))
	52	goto free_tree;
	53
	54	/* Load the header */
	55	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	56	tree->root = be32_to_cpu(head->root);
	57	tree->leaf_count = be32_to_cpu(head->leaf_count);
	58	tree->leaf_head = be32_to_cpu(head->leaf_head);
	59	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	60	tree->node_count = be32_to_cpu(head->node_count);
	61	tree->free_nodes = be32_to_cpu(head->free_nodes);
	62	tree->attributes = be32_to_cpu(head->attributes);
	63	tree->node_size = be16_to_cpu(head->node_size);
	64	tree->max_key_len = be16_to_cpu(head->max_key_len);
	65	tree->depth = be16_to_cpu(head->depth);
	66
	67	size = tree->node_size;
	68	if (!size \|\| size & (size - 1))
	69	goto fail_page;
	70	if (!tree->node_count)
	71	goto fail_page;
	72	tree->node_size_shift = ffs(size) - 1;
	73
	74	tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
	75
	76	kunmap(page);
	77	page_cache_release(page);
	78	return tree;
	79
	80	fail_page:
	81	tree->inode->i_mapping->a_ops = &hfsplus_aops;
	82	page_cache_release(page);
	83	free_tree:
	84	iput(tree->inode);
	85	kfree(tree);
	86	return NULL;
	87	}
	88
	89	/* Release resources used by a btree */
	90	void hfs_btree_close(struct hfs_btree *tree)
	91	{
	92	struct hfs_bnode *node;
	93	int i;
	94
	95	if (!tree)
	96	return;
	97
	98	for (i = 0; i < NODE_HASH_SIZE; i++) {
	99	while ((node = tree->node_hash[i])) {
	100	tree->node_hash[i] = node->next_hash;
	101	if (atomic_read(&node->refcnt))
634725a9	102	printk(KERN_CRIT "hfs: node %d:%d still has %d user(s)!\n",
1da177e4 LT	103	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	104	hfs_bnode_free(node);
	105	tree->node_hash_cnt--;
	106	}
	107	}
	108	iput(tree->inode);
	109	kfree(tree);
	110	}
	111
	112	void hfs_btree_write(struct hfs_btree *tree)
	113	{
	114	struct hfs_btree_header_rec *head;
	115	struct hfs_bnode *node;
	116	struct page *page;
	117
	118	node = hfs_bnode_find(tree, 0);
	119	if (IS_ERR(node))
	120	/* panic? */
	121	return;
	122	/* Load the header */
	123	page = node->page[0];
	124	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	125
	126	head->root = cpu_to_be32(tree->root);
	127	head->leaf_count = cpu_to_be32(tree->leaf_count);
	128	head->leaf_head = cpu_to_be32(tree->leaf_head);
	129	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	130	head->node_count = cpu_to_be32(tree->node_count);
	131	head->free_nodes = cpu_to_be32(tree->free_nodes);
	132	head->attributes = cpu_to_be32(tree->attributes);
	133	head->depth = cpu_to_be16(tree->depth);
	134
	135	kunmap(page);
	136	set_page_dirty(page);
	137	hfs_bnode_put(node);
	138	}
	139
	140	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	141	{
	142	struct hfs_btree *tree = prev->tree;
	143	struct hfs_bnode *node;
	144	struct hfs_bnode_desc desc;
	145	__be32 cnid;
	146
	147	node = hfs_bnode_create(tree, idx);
	148	if (IS_ERR(node))
	149	return node;
	150
	151	tree->free_nodes--;
	152	prev->next = idx;
	153	cnid = cpu_to_be32(idx);
	154	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	155
	156	node->type = HFS_NODE_MAP;
	157	node->num_recs = 1;
	158	hfs_bnode_clear(node, 0, tree->node_size);
	159	desc.next = 0;
	160	desc.prev = 0;
	161	desc.type = HFS_NODE_MAP;
	162	desc.height = 0;
	163	desc.num_recs = cpu_to_be16(1);
	164	desc.reserved = 0;
	165	hfs_bnode_write(node, &desc, 0, sizeof(desc));
	166	hfs_bnode_write_u16(node, 14, 0x8000);
167	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
168	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
169
170	return node;
171	}
172
173	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
174	{
175	struct hfs_bnode node, next_node;
176	struct page **pagep;
177	u32 nidx, idx;
178	u16 off, len;
179	u8 *data, byte, m;
180	int i;
181
182	while (!tree->free_nodes) {
183	struct inode *inode = tree->inode;
184	u32 count;
185	int res;
186
187	res = hfsplus_file_extend(inode);
188	if (res)
189	return ERR_PTR(res);
190	HFSPLUS_I(inode).phys_size = inode->i_size =
191	(loff_t)HFSPLUS_I(inode).alloc_blocks <<
192	HFSPLUS_SB(tree->sb).alloc_blksz_shift;
193	HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).alloc_blocks <<
194	HFSPLUS_SB(tree->sb).fs_shift;
195	inode_set_bytes(inode, inode->i_size);
196	count = inode->i_size >> tree->node_size_shift;
197	tree->free_nodes = count - tree->node_count;
198	tree->node_count = count;
199	}
200
201	nidx = 0;
202	node = hfs_bnode_find(tree, nidx);
203	if (IS_ERR(node))
204	return node;
205	len = hfs_brec_lenoff(node, 2, &off);
206
207	off += node->page_offset;
208	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
209	data = kmap(*pagep);
210	off &= ~PAGE_CACHE_MASK;
211	idx = 0;
212
213	for (;;) {
214	while (len) {
215	byte = data[off];
216	if (byte != 0xff) {
217	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
218	if (!(byte & m)) {
219	idx += i;
220	data[off] \|= m;
221	set_page_dirty(*pagep);
222	kunmap(*pagep);
223	tree->free_nodes--;
224	mark_inode_dirty(tree->inode);
225	hfs_bnode_put(node);
1da177e4 LT	226	return hfs_bnode_create(tree, idx);
	227	}
	228	}
	229	}
	230	if (++off >= PAGE_CACHE_SIZE) {
	231	kunmap(*pagep);
	232	data = kmap(*++pagep);
	233	off = 0;
	234	}
	235	idx += 8;
	236	len--;
	237	}
	238	kunmap(*pagep);
	239	nidx = node->next;
	240	if (!nidx) {
634725a9	241	printk(KERN_DEBUG "hfs: create new bmap node...\n");
1da177e4 LT	242	next_node = hfs_bmap_new_bmap(node, idx);
	243	} else
	244	next_node = hfs_bnode_find(tree, nidx);
	245	hfs_bnode_put(node);
	246	if (IS_ERR(next_node))
	247	return next_node;
	248	node = next_node;
	249
	250	len = hfs_brec_lenoff(node, 0, &off);
	251	off += node->page_offset;
	252	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	253	data = kmap(*pagep);
	254	off &= ~PAGE_CACHE_MASK;
	255	}
	256	}
	257
	258	void hfs_bmap_free(struct hfs_bnode *node)
	259	{
	260	struct hfs_btree *tree;
	261	struct page *page;
	262	u16 off, len;
	263	u32 nidx;
	264	u8 *data, byte, m;
	265
	266	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
	267	if (!node->this)
	268	BUG();
	269	tree = node->tree;
	270	nidx = node->this;
	271	node = hfs_bnode_find(tree, 0);
	272	if (IS_ERR(node))
	273	return;
	274	len = hfs_brec_lenoff(node, 2, &off);
	275	while (nidx >= len * 8) {
	276	u32 i;
	277
	278	nidx -= len * 8;
	279	i = node->next;
	280	hfs_bnode_put(node);
	281	if (!i) {
	282	/* panic */;
634725a9	283	printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
1da177e4 LT	284	return;
	285	}
	286	node = hfs_bnode_find(tree, i);
	287	if (IS_ERR(node))
	288	return;
	289	if (node->type != HFS_NODE_MAP) {
	290	/* panic */;
634725a9	291	printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
1da177e4 LT	292	hfs_bnode_put(node);
	293	return;
	294	}
	295	len = hfs_brec_lenoff(node, 0, &off);
	296	}
	297	off += node->page_offset + nidx / 8;
	298	page = node->page[off >> PAGE_CACHE_SHIFT];
	299	data = kmap(page);
	300	off &= ~PAGE_CACHE_MASK;
	301	m = 1 << (~nidx & 7);
	302	byte = data[off];
	303	if (!(byte & m)) {
634725a9	304	printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
1da177e4 LT	305	kunmap(page);
	306	hfs_bnode_put(node);
	307	return;
	308	}
	309	data[off] = byte & ~m;
	310	set_page_dirty(page);
	311	kunmap(page);
	312	hfs_bnode_put(node);
	313	tree->free_nodes++;
	314	mark_inode_dirty(tree->inode);
	315	}