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

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

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

#include "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);
	tree->sb = sb;
	tree->cnid = id;
	tree->inode = iget(sb, id);
	if (!tree->inode)
		goto free_tree;

	mapping = tree->inode->i_mapping;
	page = read_mapping_page(mapping, 0, 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);

	/* Set the correct compare function */
	if (id == HFSPLUS_EXT_CNID) {
		tree->keycmp = hfsplus_ext_cmp_key;
	} else if (id == HFSPLUS_CAT_CNID) {
		if ((HFSPLUS_SB(sb).flags & HFSPLUS_SB_HFSX) &&
		    (head->key_type == HFSPLUS_KEY_BINARY))
			tree->keycmp = hfsplus_cat_bin_cmp_key;
		else
			tree->keycmp = hfsplus_cat_case_cmp_key;
	} else {
		printk(KERN_ERR "hfs: unknown B*Tree requested\n");
		goto fail_page;
	}

	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);
	BUG_ON(!node->this);
	tree = node->tree;
	nidx = node->this;
	node = hfs_bnode_find(tree, 0);
	if (IS_ERR(node))
		return;
	len = hfs_brec_lenoff(node, 2, &off);
	while (nidx >= len * 8) {
		u32 i;

		nidx -= len * 8;
		i = node->next;
		hfs_bnode_put(node);
		if (!i) {
			/* panic */;
			printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
			return;
		}
		node = hfs_bnode_find(tree, i);
		if (IS_ERR(node))
			return;
		if (node->type != HFS_NODE_MAP) {
			/* panic */;
			printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
			hfs_bnode_put(node);
			return;
		}
		len = hfs_brec_lenoff(node, 0, &off);
	}
	off += node->page_offset + nidx / 8;
	page = node->page[off >> PAGE_CACHE_SHIFT];
	data = kmap(page);
	off &= ~PAGE_CACHE_MASK;
	m = 1 << (~nidx & 7);
	byte = data[off];
	if (!(byte & m)) {
		printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
		kunmap(page);
		hfs_bnode_put(node);
		return;
	}
	data[off] = byte & ~m;
	set_page_dirty(page);
	kunmap(page);
	hfs_bnode_put(node);
	tree->free_nodes++;
	mark_inode_dirty(tree->inode);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfsplus/btree.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer (flar@allandria.com)
	6	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	7	*
	8	* Handle opening/closing btree
	9	*/
	10
	11	#include <linux/slab.h>
	12	#include <linux/pagemap.h>
	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);
1da177e4 LT	34	tree->sb = sb;
1da177e4 LT	35	tree->cnid = id;
1da177e4 LT	36	tree->inode = iget(sb, id);
	37	if (!tree->inode)
	38	goto free_tree;
	39
	40	mapping = tree->inode->i_mapping;
090d2b18	41	page = read_mapping_page(mapping, 0, NULL);
1da177e4 LT	42	if (IS_ERR(page))
	43	goto free_tree;
	44
	45	/* Load the header */
	46	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	47	tree->root = be32_to_cpu(head->root);
	48	tree->leaf_count = be32_to_cpu(head->leaf_count);
	49	tree->leaf_head = be32_to_cpu(head->leaf_head);
	50	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	51	tree->node_count = be32_to_cpu(head->node_count);
	52	tree->free_nodes = be32_to_cpu(head->free_nodes);
	53	tree->attributes = be32_to_cpu(head->attributes);
	54	tree->node_size = be16_to_cpu(head->node_size);
	55	tree->max_key_len = be16_to_cpu(head->max_key_len);
	56	tree->depth = be16_to_cpu(head->depth);
	57
2179d372 DE	58	/* Set the correct compare function */
	59	if (id == HFSPLUS_EXT_CNID) {
	60	tree->keycmp = hfsplus_ext_cmp_key;
	61	} else if (id == HFSPLUS_CAT_CNID) {
	62	if ((HFSPLUS_SB(sb).flags & HFSPLUS_SB_HFSX) &&
	63	(head->key_type == HFSPLUS_KEY_BINARY))
	64	tree->keycmp = hfsplus_cat_bin_cmp_key;
	65	else
	66	tree->keycmp = hfsplus_cat_case_cmp_key;
	67	} else {
	68	printk(KERN_ERR "hfs: unknown B*Tree requested\n");
	69	goto fail_page;
	70	}
	71
1da177e4 LT	72	size = tree->node_size;
	73	if (!size \|\| size & (size - 1))
	74	goto fail_page;
	75	if (!tree->node_count)
	76	goto fail_page;
	77	tree->node_size_shift = ffs(size) - 1;
	78
	79	tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
	80
	81	kunmap(page);
	82	page_cache_release(page);
	83	return tree;
	84
	85	fail_page:
	86	tree->inode->i_mapping->a_ops = &hfsplus_aops;
	87	page_cache_release(page);
	88	free_tree:
	89	iput(tree->inode);
	90	kfree(tree);
	91	return NULL;
	92	}
	93
	94	/* Release resources used by a btree */
	95	void hfs_btree_close(struct hfs_btree *tree)
	96	{
	97	struct hfs_bnode *node;
	98	int i;
	99
	100	if (!tree)
	101	return;
	102
	103	for (i = 0; i < NODE_HASH_SIZE; i++) {
	104	while ((node = tree->node_hash[i])) {
	105	tree->node_hash[i] = node->next_hash;
	106	if (atomic_read(&node->refcnt))
634725a9	107	printk(KERN_CRIT "hfs: node %d:%d still has %d user(s)!\n",
1da177e4 LT	108	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	109	hfs_bnode_free(node);
	110	tree->node_hash_cnt--;
	111	}
	112	}
	113	iput(tree->inode);
	114	kfree(tree);
	115	}
	116
	117	void hfs_btree_write(struct hfs_btree *tree)
	118	{
	119	struct hfs_btree_header_rec *head;
	120	struct hfs_bnode *node;
	121	struct page *page;
	122
	123	node = hfs_bnode_find(tree, 0);
	124	if (IS_ERR(node))
	125	/* panic? */
	126	return;
	127	/* Load the header */
	128	page = node->page[0];
	129	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	130
	131	head->root = cpu_to_be32(tree->root);
	132	head->leaf_count = cpu_to_be32(tree->leaf_count);
	133	head->leaf_head = cpu_to_be32(tree->leaf_head);
	134	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	135	head->node_count = cpu_to_be32(tree->node_count);
	136	head->free_nodes = cpu_to_be32(tree->free_nodes);
	137	head->attributes = cpu_to_be32(tree->attributes);
	138	head->depth = cpu_to_be16(tree->depth);
	139
	140	kunmap(page);
	141	set_page_dirty(page);
	142	hfs_bnode_put(node);
	143	}
	144
	145	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	146	{
	147	struct hfs_btree *tree = prev->tree;
	148	struct hfs_bnode *node;
	149	struct hfs_bnode_desc desc;
	150	__be32 cnid;
	151
	152	node = hfs_bnode_create(tree, idx);
	153	if (IS_ERR(node))
	154	return node;
	155
	156	tree->free_nodes--;
	157	prev->next = idx;
	158	cnid = cpu_to_be32(idx);
	159	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	160
	161	node->type = HFS_NODE_MAP;
	162	node->num_recs = 1;
	163	hfs_bnode_clear(node, 0, tree->node_size);
	164	desc.next = 0;
	165	desc.prev = 0;
	166	desc.type = HFS_NODE_MAP;
	167	desc.height = 0;
	168	desc.num_recs = cpu_to_be16(1);
	169	desc.reserved = 0;
	170	hfs_bnode_write(node, &desc, 0, sizeof(desc));
	171	hfs_bnode_write_u16(node, 14, 0x8000);
172	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
173	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
174
175	return node;
176	}
177
178	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
179	{
180	struct hfs_bnode node, next_node;
181	struct page **pagep;
182	u32 nidx, idx;
183	u16 off, len;
184	u8 *data, byte, m;
185	int i;
186
187	while (!tree->free_nodes) {
188	struct inode *inode = tree->inode;
189	u32 count;
190	int res;
191
192	res = hfsplus_file_extend(inode);
193	if (res)
194	return ERR_PTR(res);
195	HFSPLUS_I(inode).phys_size = inode->i_size =
196	(loff_t)HFSPLUS_I(inode).alloc_blocks <<
197	HFSPLUS_SB(tree->sb).alloc_blksz_shift;
198	HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).alloc_blocks <<
199	HFSPLUS_SB(tree->sb).fs_shift;
200	inode_set_bytes(inode, inode->i_size);
201	count = inode->i_size >> tree->node_size_shift;
202	tree->free_nodes = count - tree->node_count;
203	tree->node_count = count;
204	}
205
206	nidx = 0;
207	node = hfs_bnode_find(tree, nidx);
208	if (IS_ERR(node))
209	return node;
210	len = hfs_brec_lenoff(node, 2, &off);
211
212	off += node->page_offset;
213	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
214	data = kmap(*pagep);
215	off &= ~PAGE_CACHE_MASK;
216	idx = 0;
217
218	for (;;) {
219	while (len) {
220	byte = data[off];
221	if (byte != 0xff) {
222	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
223	if (!(byte & m)) {
224	idx += i;
225	data[off] \|= m;
226	set_page_dirty(*pagep);
227	kunmap(*pagep);
228	tree->free_nodes--;
229	mark_inode_dirty(tree->inode);
230	hfs_bnode_put(node);
1da177e4 LT	231	return hfs_bnode_create(tree, idx);
	232	}
	233	}
	234	}
	235	if (++off >= PAGE_CACHE_SIZE) {
	236	kunmap(*pagep);
	237	data = kmap(*++pagep);
	238	off = 0;
	239	}
	240	idx += 8;
	241	len--;
	242	}
	243	kunmap(*pagep);
	244	nidx = node->next;
	245	if (!nidx) {
634725a9	246	printk(KERN_DEBUG "hfs: create new bmap node...\n");
1da177e4 LT	247	next_node = hfs_bmap_new_bmap(node, idx);
	248	} else
	249	next_node = hfs_bnode_find(tree, nidx);
	250	hfs_bnode_put(node);
	251	if (IS_ERR(next_node))
	252	return next_node;
	253	node = next_node;
	254
	255	len = hfs_brec_lenoff(node, 0, &off);
	256	off += node->page_offset;
	257	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	258	data = kmap(*pagep);
	259	off &= ~PAGE_CACHE_MASK;
	260	}
	261	}
	262
	263	void hfs_bmap_free(struct hfs_bnode *node)
	264	{
	265	struct hfs_btree *tree;
	266	struct page *page;
	267	u16 off, len;
	268	u32 nidx;
	269	u8 *data, byte, m;
	270
	271	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
0bf3ba53	272	BUG_ON(!node->this);
1da177e4 LT	273	tree = node->tree;
	274	nidx = node->this;
	275	node = hfs_bnode_find(tree, 0);
	276	if (IS_ERR(node))
	277	return;
	278	len = hfs_brec_lenoff(node, 2, &off);
	279	while (nidx >= len * 8) {
	280	u32 i;
	281
	282	nidx -= len * 8;
	283	i = node->next;
	284	hfs_bnode_put(node);
	285	if (!i) {
	286	/* panic */;
634725a9	287	printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
1da177e4 LT	288	return;
	289	}
	290	node = hfs_bnode_find(tree, i);
	291	if (IS_ERR(node))
	292	return;
	293	if (node->type != HFS_NODE_MAP) {
	294	/* panic */;
634725a9	295	printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
1da177e4 LT	296	hfs_bnode_put(node);
	297	return;
	298	}
	299	len = hfs_brec_lenoff(node, 0, &off);
	300	}
	301	off += node->page_offset + nidx / 8;
	302	page = node->page[off >> PAGE_CACHE_SHIFT];
	303	data = kmap(page);
	304	off &= ~PAGE_CACHE_MASK;
	305	m = 1 << (~nidx & 7);
	306	byte = data[off];
	307	if (!(byte & m)) {
634725a9	308	printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
1da177e4 LT	309	kunmap(page);
	310	hfs_bnode_put(node);
	311	return;
	312	}
	313	data[off] = byte & ~m;
	314	set_page_dirty(page);
	315	kunmap(page);
	316	hfs_bnode_put(node);
	317	tree->free_nodes++;
	318	mark_inode_dirty(tree->inode);
	319	}