[linux.git] / fs / hfs / btree.c

/*
 *  linux/fs/hfs/btree.c
 *
 * Copyright (C) 2001
 * Brad Boyer ([email protected])
 * (C) 2003 Ardis Technologies <[email protected]>
 *
 * Handle opening/closing btree
 */

#include <linux/pagemap.h>

#include "btree.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, btree_keycmp keycmp)
{
	struct hfs_btree *tree;
	struct hfs_btree_header_rec *head;
	struct address_space *mapping;
	struct page *page;
	unsigned int size;

	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
	if (!tree)
		return NULL;

	init_MUTEX(&tree->tree_lock);
	spin_lock_init(&tree->hash_lock);
	/* Set the correct compare function */
	tree->sb = sb;
	tree->cnid = id;
	tree->keycmp = keycmp;

	tree->inode = iget_locked(sb, id);
	if (!tree->inode)
		goto free_tree;
	BUG_ON(!(tree->inode->i_state & I_NEW));
	{
	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
	HFS_I(tree->inode)->flags = 0;
	init_MUTEX(&HFS_I(tree->inode)->extents_lock);
	switch (id) {
	case HFS_EXT_CNID:
		hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
				    mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
		break;
	case HFS_CAT_CNID:
		hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
				    mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
		break;
	default:
		BUG();
	}
	}
	unlock_new_inode(tree->inode);

	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);

	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 = &hfs_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_ERR "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;

	if (!tree->free_nodes)
		panic("FIXME!!!");
	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 = hfs_extend_file(inode);
		if (res)
			return ERR_PTR(res);
		HFS_I(inode)->phys_size = inode->i_size =
				(loff_t)HFS_I(inode)->alloc_blocks *
				HFS_SB(tree->sb)->alloc_blksz;
		HFS_I(inode)->fs_blocks = inode->i_size >>
					  tree->sb->s_blocksize_bits;
		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);
	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/hfs/btree.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer ([email protected])
	6	* (C) 2003 Ardis Technologies <[email protected]>
	7	*
	8	* Handle opening/closing btree
	9	*/
	10
	11	#include <linux/pagemap.h>
	12
	13	#include "btree.h"
	14
	15	/* Get a reference to a BTree and do some initial checks /
	16	struct hfs_btree hfs_btree_open(struct super_block sb, u32 id, btree_keycmp keycmp)
	17	{
	18	struct hfs_btree *tree;
	19	struct hfs_btree_header_rec *head;
	20	struct address_space *mapping;
	21	struct page *page;
	22	unsigned int size;
	23
f8314dc6	24	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
1da177e4 LT	25	if (!tree)
1da177e4 LT	26	return NULL;
1da177e4 LT	27
	28	init_MUTEX(&tree->tree_lock);
	29	spin_lock_init(&tree->hash_lock);
	30	/* Set the correct compare function */
	31	tree->sb = sb;
	32	tree->cnid = id;
	33	tree->keycmp = keycmp;
	34
	35	tree->inode = iget_locked(sb, id);
	36	if (!tree->inode)
	37	goto free_tree;
4d4ef9ab	38	BUG_ON(!(tree->inode->i_state & I_NEW));
1da177e4 LT	39	{
	40	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
	41	HFS_I(tree->inode)->flags = 0;
	42	init_MUTEX(&HFS_I(tree->inode)->extents_lock);
	43	switch (id) {
	44	case HFS_EXT_CNID:
	45	hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
	46	mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
	47	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	48	break;
	49	case HFS_CAT_CNID:
	50	hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
	51	mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
	52	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	53	break;
	54	default:
	55	BUG();
	56	}
	57	}
	58	unlock_new_inode(tree->inode);
	59
	60	mapping = tree->inode->i_mapping;
090d2b18	61	page = read_mapping_page(mapping, 0, NULL);
1da177e4 LT	62	if (IS_ERR(page))
	63	goto free_tree;
	64
	65	/* Load the header */
	66	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	67	tree->root = be32_to_cpu(head->root);
	68	tree->leaf_count = be32_to_cpu(head->leaf_count);
	69	tree->leaf_head = be32_to_cpu(head->leaf_head);
	70	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	71	tree->node_count = be32_to_cpu(head->node_count);
	72	tree->free_nodes = be32_to_cpu(head->free_nodes);
	73	tree->attributes = be32_to_cpu(head->attributes);
	74	tree->node_size = be16_to_cpu(head->node_size);
	75	tree->max_key_len = be16_to_cpu(head->max_key_len);
	76	tree->depth = be16_to_cpu(head->depth);
	77
	78	size = tree->node_size;
	79	if (!size \|\| size & (size - 1))
	80	goto fail_page;
	81	if (!tree->node_count)
	82	goto fail_page;
	83	tree->node_size_shift = ffs(size) - 1;
	84	tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
	85
	86	kunmap(page);
	87	page_cache_release(page);
	88	return tree;
	89
	90	fail_page:
	91	tree->inode->i_mapping->a_ops = &hfs_aops;
	92	page_cache_release(page);
	93	free_tree:
	94	iput(tree->inode);
	95	kfree(tree);
	96	return NULL;
	97	}
	98
	99	/* Release resources used by a btree */
	100	void hfs_btree_close(struct hfs_btree *tree)
	101	{
	102	struct hfs_bnode *node;
	103	int i;
	104
	105	if (!tree)
	106	return;
	107
	108	for (i = 0; i < NODE_HASH_SIZE; i++) {
	109	while ((node = tree->node_hash[i])) {
	110	tree->node_hash[i] = node->next_hash;
	111	if (atomic_read(&node->refcnt))
7cf3cc30	112	printk(KERN_ERR "hfs: node %d:%d still has %d user(s)!\n",
1da177e4 LT	113	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	114	hfs_bnode_free(node);
	115	tree->node_hash_cnt--;
	116	}
	117	}
	118	iput(tree->inode);
	119	kfree(tree);
	120	}
	121
	122	void hfs_btree_write(struct hfs_btree *tree)
	123	{
	124	struct hfs_btree_header_rec *head;
	125	struct hfs_bnode *node;
	126	struct page *page;
	127
	128	node = hfs_bnode_find(tree, 0);
	129	if (IS_ERR(node))
	130	/* panic? */
	131	return;
	132	/* Load the header */
	133	page = node->page[0];
	134	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	135
	136	head->root = cpu_to_be32(tree->root);
	137	head->leaf_count = cpu_to_be32(tree->leaf_count);
	138	head->leaf_head = cpu_to_be32(tree->leaf_head);
	139	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	140	head->node_count = cpu_to_be32(tree->node_count);
	141	head->free_nodes = cpu_to_be32(tree->free_nodes);
	142	head->attributes = cpu_to_be32(tree->attributes);
	143	head->depth = cpu_to_be16(tree->depth);
	144
	145	kunmap(page);
	146	set_page_dirty(page);
	147	hfs_bnode_put(node);
	148	}
	149
	150	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	151	{
	152	struct hfs_btree *tree = prev->tree;
	153	struct hfs_bnode *node;
	154	struct hfs_bnode_desc desc;
	155	__be32 cnid;
	156
	157	node = hfs_bnode_create(tree, idx);
	158	if (IS_ERR(node))
	159	return node;
	160
	161	if (!tree->free_nodes)
	162	panic("FIXME!!!");
	163	tree->free_nodes--;
	164	prev->next = idx;
	165	cnid = cpu_to_be32(idx);
	166	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	167
	168	node->type = HFS_NODE_MAP;
	169	node->num_recs = 1;
	170	hfs_bnode_clear(node, 0, tree->node_size);
	171	desc.next = 0;
	172	desc.prev = 0;
	173	desc.type = HFS_NODE_MAP;
	174	desc.height = 0;
	175	desc.num_recs = cpu_to_be16(1);
	176	desc.reserved = 0;
177	hfs_bnode_write(node, &desc, 0, sizeof(desc));
178	hfs_bnode_write_u16(node, 14, 0x8000);
179	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
180	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
181
182	return node;
183	}
184
185	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
186	{
187	struct hfs_bnode node, next_node;
188	struct page **pagep;
189	u32 nidx, idx;
190	u16 off, len;
191	u8 *data, byte, m;
192	int i;
193
194	while (!tree->free_nodes) {
195	struct inode *inode = tree->inode;
196	u32 count;
197	int res;
198
199	res = hfs_extend_file(inode);
200	if (res)
201	return ERR_PTR(res);
202	HFS_I(inode)->phys_size = inode->i_size =
203	(loff_t)HFS_I(inode)->alloc_blocks *
204	HFS_SB(tree->sb)->alloc_blksz;
205	HFS_I(inode)->fs_blocks = inode->i_size >>
206	tree->sb->s_blocksize_bits;
207	inode_set_bytes(inode, inode->i_size);
208	count = inode->i_size >> tree->node_size_shift;
209	tree->free_nodes = count - tree->node_count;
210	tree->node_count = count;
211	}
212
213	nidx = 0;
214	node = hfs_bnode_find(tree, nidx);
215	if (IS_ERR(node))
216	return node;
217	len = hfs_brec_lenoff(node, 2, &off);
218
219	off += node->page_offset;
220	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
221	data = kmap(*pagep);
222	off &= ~PAGE_CACHE_MASK;
223	idx = 0;
224
225	for (;;) {
226	while (len) {
227	byte = data[off];
228	if (byte != 0xff) {
229	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
230	if (!(byte & m)) {
231	idx += i;
232	data[off] \|= m;
233	set_page_dirty(*pagep);
234	kunmap(*pagep);
235	tree->free_nodes--;
236	mark_inode_dirty(tree->inode);
237	hfs_bnode_put(node);
238	return hfs_bnode_create(tree, idx);
239	}
240	}
241	}
242	if (++off >= PAGE_CACHE_SIZE) {
243	kunmap(*pagep);
244	data = kmap(*++pagep);
245	off = 0;
246	}
247	idx += 8;
248	len--;
249	}
250	kunmap(*pagep);
251	nidx = node->next;
252	if (!nidx) {
7cf3cc30	253	printk(KERN_DEBUG "hfs: create new bmap node...\n");
1da177e4 LT	254	next_node = hfs_bmap_new_bmap(node, idx);
	255	} else
	256	next_node = hfs_bnode_find(tree, nidx);
	257	hfs_bnode_put(node);
	258	if (IS_ERR(next_node))
	259	return next_node;
	260	node = next_node;
	261
	262	len = hfs_brec_lenoff(node, 0, &off);
	263	off += node->page_offset;
	264	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	265	data = kmap(*pagep);
	266	off &= ~PAGE_CACHE_MASK;
	267	}
	268	}
	269
	270	void hfs_bmap_free(struct hfs_bnode *node)
	271	{
	272	struct hfs_btree *tree;
	273	struct page *page;
	274	u16 off, len;
	275	u32 nidx;
	276	u8 *data, byte, m;
	277
	278	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
	279	tree = node->tree;
	280	nidx = node->this;
	281	node = hfs_bnode_find(tree, 0);
	282	if (IS_ERR(node))
	283	return;
	284	len = hfs_brec_lenoff(node, 2, &off);
	285	while (nidx >= len * 8) {
	286	u32 i;
	287
	288	nidx -= len * 8;
	289	i = node->next;
	290	hfs_bnode_put(node);
	291	if (!i) {
	292	/* panic */;
7cf3cc30	293	printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
1da177e4 LT	294	return;
	295	}
	296	node = hfs_bnode_find(tree, i);
	297	if (IS_ERR(node))
	298	return;
	299	if (node->type != HFS_NODE_MAP) {
	300	/* panic */;
7cf3cc30	301	printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
1da177e4 LT	302	hfs_bnode_put(node);
	303	return;
	304	}
	305	len = hfs_brec_lenoff(node, 0, &off);
	306	}
	307	off += node->page_offset + nidx / 8;
	308	page = node->page[off >> PAGE_CACHE_SHIFT];
	309	data = kmap(page);
	310	off &= ~PAGE_CACHE_MASK;
	311	m = 1 << (~nidx & 7);
	312	byte = data[off];
	313	if (!(byte & m)) {
7cf3cc30	314	printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
1da177e4 LT	315	kunmap(page);
	316	hfs_bnode_put(node);
	317	return;
	318	}
	319	data[off] = byte & ~m;
	320	set_page_dirty(page);
	321	kunmap(page);
	322	hfs_bnode_put(node);
	323	tree->free_nodes++;
	324	mark_inode_dirty(tree->inode);
	325	}