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

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

#include <linux/pagemap.h>
#include <linux/log2.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 (!is_power_of_2(size))
		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 (flar@allandria.com)
	6	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	7	*
	8	* Handle opening/closing btree
	9	*/
	10
	11	#include <linux/pagemap.h>
e1b5c1d3	12	#include <linux/log2.h>
1da177e4 LT	13
	14	#include "btree.h"
	15
	16	/* Get a reference to a BTree and do some initial checks /
	17	struct hfs_btree hfs_btree_open(struct super_block sb, u32 id, btree_keycmp keycmp)
	18	{
	19	struct hfs_btree *tree;
	20	struct hfs_btree_header_rec *head;
	21	struct address_space *mapping;
	22	struct page *page;
	23	unsigned int size;
	24
f8314dc6	25	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
1da177e4 LT	26	if (!tree)
1da177e4 LT	27	return NULL;
1da177e4 LT	28
	29	init_MUTEX(&tree->tree_lock);
	30	spin_lock_init(&tree->hash_lock);
	31	/* Set the correct compare function */
	32	tree->sb = sb;
	33	tree->cnid = id;
	34	tree->keycmp = keycmp;
	35
	36	tree->inode = iget_locked(sb, id);
	37	if (!tree->inode)
	38	goto free_tree;
4d4ef9ab	39	BUG_ON(!(tree->inode->i_state & I_NEW));
1da177e4 LT	40	{
	41	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
	42	HFS_I(tree->inode)->flags = 0;
	43	init_MUTEX(&HFS_I(tree->inode)->extents_lock);
	44	switch (id) {
	45	case HFS_EXT_CNID:
	46	hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
	47	mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
	48	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	49	break;
	50	case HFS_CAT_CNID:
	51	hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
	52	mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
	53	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	54	break;
	55	default:
	56	BUG();
	57	}
	58	}
	59	unlock_new_inode(tree->inode);
	60
	61	mapping = tree->inode->i_mapping;
090d2b18	62	page = read_mapping_page(mapping, 0, NULL);
1da177e4 LT	63	if (IS_ERR(page))
	64	goto free_tree;
	65
	66	/* Load the header */
	67	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	68	tree->root = be32_to_cpu(head->root);
	69	tree->leaf_count = be32_to_cpu(head->leaf_count);
	70	tree->leaf_head = be32_to_cpu(head->leaf_head);
	71	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
	72	tree->node_count = be32_to_cpu(head->node_count);
	73	tree->free_nodes = be32_to_cpu(head->free_nodes);
	74	tree->attributes = be32_to_cpu(head->attributes);
	75	tree->node_size = be16_to_cpu(head->node_size);
	76	tree->max_key_len = be16_to_cpu(head->max_key_len);
	77	tree->depth = be16_to_cpu(head->depth);
	78
	79	size = tree->node_size;
e1b5c1d3	80	if (!is_power_of_2(size))
1da177e4 LT	81	goto fail_page;
	82	if (!tree->node_count)
	83	goto fail_page;
	84	tree->node_size_shift = ffs(size) - 1;
	85	tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
	86
	87	kunmap(page);
	88	page_cache_release(page);
	89	return tree;
	90
	91	fail_page:
	92	tree->inode->i_mapping->a_ops = &hfs_aops;
	93	page_cache_release(page);
	94	free_tree:
	95	iput(tree->inode);
	96	kfree(tree);
	97	return NULL;
	98	}
	99
	100	/* Release resources used by a btree */
	101	void hfs_btree_close(struct hfs_btree *tree)
	102	{
	103	struct hfs_bnode *node;
	104	int i;
	105
	106	if (!tree)
	107	return;
	108
	109	for (i = 0; i < NODE_HASH_SIZE; i++) {
	110	while ((node = tree->node_hash[i])) {
	111	tree->node_hash[i] = node->next_hash;
	112	if (atomic_read(&node->refcnt))
7cf3cc30	113	printk(KERN_ERR "hfs: node %d:%d still has %d user(s)!\n",
1da177e4 LT	114	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	115	hfs_bnode_free(node);
	116	tree->node_hash_cnt--;
	117	}
	118	}
	119	iput(tree->inode);
	120	kfree(tree);
	121	}
	122
	123	void hfs_btree_write(struct hfs_btree *tree)
	124	{
	125	struct hfs_btree_header_rec *head;
	126	struct hfs_bnode *node;
	127	struct page *page;
	128
	129	node = hfs_bnode_find(tree, 0);
	130	if (IS_ERR(node))
	131	/* panic? */
	132	return;
	133	/* Load the header */
	134	page = node->page[0];
	135	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	136
	137	head->root = cpu_to_be32(tree->root);
	138	head->leaf_count = cpu_to_be32(tree->leaf_count);
	139	head->leaf_head = cpu_to_be32(tree->leaf_head);
	140	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	141	head->node_count = cpu_to_be32(tree->node_count);
	142	head->free_nodes = cpu_to_be32(tree->free_nodes);
	143	head->attributes = cpu_to_be32(tree->attributes);
	144	head->depth = cpu_to_be16(tree->depth);
	145
	146	kunmap(page);
	147	set_page_dirty(page);
	148	hfs_bnode_put(node);
	149	}
	150
	151	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	152	{
	153	struct hfs_btree *tree = prev->tree;
	154	struct hfs_bnode *node;
	155	struct hfs_bnode_desc desc;
	156	__be32 cnid;
	157
	158	node = hfs_bnode_create(tree, idx);
	159	if (IS_ERR(node))
	160	return node;
	161
	162	if (!tree->free_nodes)
	163	panic("FIXME!!!");
	164	tree->free_nodes--;
	165	prev->next = idx;
	166	cnid = cpu_to_be32(idx);
	167	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	168
	169	node->type = HFS_NODE_MAP;
	170	node->num_recs = 1;
	171	hfs_bnode_clear(node, 0, tree->node_size);
	172	desc.next = 0;
	173	desc.prev = 0;
	174	desc.type = HFS_NODE_MAP;
	175	desc.height = 0;
	176	desc.num_recs = cpu_to_be16(1);
	177	desc.reserved = 0;
178	hfs_bnode_write(node, &desc, 0, sizeof(desc));
179	hfs_bnode_write_u16(node, 14, 0x8000);
180	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
181	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
182
183	return node;
184	}
185
186	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
187	{
188	struct hfs_bnode node, next_node;
189	struct page **pagep;
190	u32 nidx, idx;
191	u16 off, len;
192	u8 *data, byte, m;
193	int i;
194
195	while (!tree->free_nodes) {
196	struct inode *inode = tree->inode;
197	u32 count;
198	int res;
199
200	res = hfs_extend_file(inode);
201	if (res)
202	return ERR_PTR(res);
203	HFS_I(inode)->phys_size = inode->i_size =
204	(loff_t)HFS_I(inode)->alloc_blocks *
205	HFS_SB(tree->sb)->alloc_blksz;
206	HFS_I(inode)->fs_blocks = inode->i_size >>
207	tree->sb->s_blocksize_bits;
208	inode_set_bytes(inode, inode->i_size);
209	count = inode->i_size >> tree->node_size_shift;
210	tree->free_nodes = count - tree->node_count;
211	tree->node_count = count;
212	}
213
214	nidx = 0;
215	node = hfs_bnode_find(tree, nidx);
216	if (IS_ERR(node))
217	return node;
218	len = hfs_brec_lenoff(node, 2, &off);
219
220	off += node->page_offset;
221	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
222	data = kmap(*pagep);
223	off &= ~PAGE_CACHE_MASK;
224	idx = 0;
225
226	for (;;) {
227	while (len) {
228	byte = data[off];
229	if (byte != 0xff) {
230	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
231	if (!(byte & m)) {
232	idx += i;
233	data[off] \|= m;
234	set_page_dirty(*pagep);
235	kunmap(*pagep);
236	tree->free_nodes--;
237	mark_inode_dirty(tree->inode);
238	hfs_bnode_put(node);
239	return hfs_bnode_create(tree, idx);
240	}
241	}
242	}
243	if (++off >= PAGE_CACHE_SIZE) {
244	kunmap(*pagep);
245	data = kmap(*++pagep);
246	off = 0;
247	}
248	idx += 8;
249	len--;
250	}
251	kunmap(*pagep);
252	nidx = node->next;
253	if (!nidx) {
7cf3cc30	254	printk(KERN_DEBUG "hfs: create new bmap node...\n");
1da177e4 LT	255	next_node = hfs_bmap_new_bmap(node, idx);
	256	} else
	257	next_node = hfs_bnode_find(tree, nidx);
	258	hfs_bnode_put(node);
	259	if (IS_ERR(next_node))
	260	return next_node;
	261	node = next_node;
	262
	263	len = hfs_brec_lenoff(node, 0, &off);
	264	off += node->page_offset;
	265	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	266	data = kmap(*pagep);
	267	off &= ~PAGE_CACHE_MASK;
	268	}
	269	}
	270
	271	void hfs_bmap_free(struct hfs_bnode *node)
	272	{
	273	struct hfs_btree *tree;
	274	struct page *page;
	275	u16 off, len;
	276	u32 nidx;
	277	u8 *data, byte, m;
	278
	279	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
	280	tree = node->tree;
	281	nidx = node->this;
	282	node = hfs_bnode_find(tree, 0);
	283	if (IS_ERR(node))
	284	return;
	285	len = hfs_brec_lenoff(node, 2, &off);
	286	while (nidx >= len * 8) {
	287	u32 i;
	288
	289	nidx -= len * 8;
	290	i = node->next;
	291	hfs_bnode_put(node);
	292	if (!i) {
	293	/* panic */;
7cf3cc30	294	printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
1da177e4 LT	295	return;
	296	}
	297	node = hfs_bnode_find(tree, i);
	298	if (IS_ERR(node))
	299	return;
	300	if (node->type != HFS_NODE_MAP) {
	301	/* panic */;
7cf3cc30	302	printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
1da177e4 LT	303	hfs_bnode_put(node);
	304	return;
	305	}
	306	len = hfs_brec_lenoff(node, 0, &off);
	307	}
	308	off += node->page_offset + nidx / 8;
	309	page = node->page[off >> PAGE_CACHE_SHIFT];
	310	data = kmap(page);
	311	off &= ~PAGE_CACHE_MASK;
	312	m = 1 << (~nidx & 7);
	313	byte = data[off];
	314	if (!(byte & m)) {
7cf3cc30	315	printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
1da177e4 LT	316	kunmap(page);
	317	hfs_bnode_put(node);
	318	return;
	319	}
	320	data[off] = byte & ~m;
	321	set_page_dirty(page);
	322	kunmap(page);
	323	hfs_bnode_put(node);
	324	tree->free_nodes++;
	325	mark_inode_dirty(tree->inode);
	326	}