[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 = 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;
	tree->keycmp = keycmp;

	tree->inode = iget_locked(sb, id);
	if (!tree->inode)
		goto free_tree;
	if (!(tree->inode->i_state & I_NEW))
		BUG();
	{
	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_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 = &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("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("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("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("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("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
	24	tree = kmalloc(sizeof(*tree), GFP_KERNEL);
	25	if (!tree)
	26	return NULL;
	27	memset(tree, 0, sizeof(*tree));
	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;
	39	if (!(tree->inode->i_state & I_NEW))
	40	BUG();
	41	{
	42	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
	43	HFS_I(tree->inode)->flags = 0;
	44	init_MUTEX(&HFS_I(tree->inode)->extents_lock);
	45	switch (id) {
	46	case HFS_EXT_CNID:
	47	hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
	48	mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
	49	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	50	break;
	51	case HFS_CAT_CNID:
	52	hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
	53	mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
	54	tree->inode->i_mapping->a_ops = &hfs_btree_aops;
	55	break;
	56	default:
	57	BUG();
	58	}
	59	}
	60	unlock_new_inode(tree->inode);
	61
	62	mapping = tree->inode->i_mapping;
	63	page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL);
	64	if (IS_ERR(page))
65	goto free_tree;
66
67	/* Load the header */
68	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
69	tree->root = be32_to_cpu(head->root);
70	tree->leaf_count = be32_to_cpu(head->leaf_count);
71	tree->leaf_head = be32_to_cpu(head->leaf_head);
72	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
73	tree->node_count = be32_to_cpu(head->node_count);
74	tree->free_nodes = be32_to_cpu(head->free_nodes);
75	tree->attributes = be32_to_cpu(head->attributes);
76	tree->node_size = be16_to_cpu(head->node_size);
77	tree->max_key_len = be16_to_cpu(head->max_key_len);
78	tree->depth = be16_to_cpu(head->depth);
79
80	size = tree->node_size;
81	if (!size \|\| size & (size - 1))
82	goto fail_page;
83	if (!tree->node_count)
84	goto fail_page;
85	tree->node_size_shift = ffs(size) - 1;
86	tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
87
88	kunmap(page);
89	page_cache_release(page);
90	return tree;
91
92	fail_page:
93	tree->inode->i_mapping->a_ops = &hfs_aops;
94	page_cache_release(page);
95	free_tree:
96	iput(tree->inode);
97	kfree(tree);
98	return NULL;
99	}
100
101	/* Release resources used by a btree */
102	void hfs_btree_close(struct hfs_btree *tree)
103	{
104	struct hfs_bnode *node;
105	int i;
106
107	if (!tree)
108	return;
109
110	for (i = 0; i < NODE_HASH_SIZE; i++) {
111	while ((node = tree->node_hash[i])) {
112	tree->node_hash[i] = node->next_hash;
113	if (atomic_read(&node->refcnt))
114	printk("HFS: node %d:%d still has %d user(s)!\n",
115	node->tree->cnid, node->this, atomic_read(&node->refcnt));
116	hfs_bnode_free(node);
117	tree->node_hash_cnt--;
118	}
119	}
120	iput(tree->inode);
121	kfree(tree);
122	}
123
124	void hfs_btree_write(struct hfs_btree *tree)
125	{
126	struct hfs_btree_header_rec *head;
127	struct hfs_bnode *node;
128	struct page *page;
129
130	node = hfs_bnode_find(tree, 0);
131	if (IS_ERR(node))
132	/* panic? */
133	return;
134	/* Load the header */
135	page = node->page[0];
136	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
137
138	head->root = cpu_to_be32(tree->root);
139	head->leaf_count = cpu_to_be32(tree->leaf_count);
140	head->leaf_head = cpu_to_be32(tree->leaf_head);
141	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
142	head->node_count = cpu_to_be32(tree->node_count);
143	head->free_nodes = cpu_to_be32(tree->free_nodes);
144	head->attributes = cpu_to_be32(tree->attributes);
145	head->depth = cpu_to_be16(tree->depth);
146
147	kunmap(page);
148	set_page_dirty(page);
149	hfs_bnode_put(node);
150	}
151
152	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
153	{
154	struct hfs_btree *tree = prev->tree;
155	struct hfs_bnode *node;
156	struct hfs_bnode_desc desc;
157	__be32 cnid;
158
159	node = hfs_bnode_create(tree, idx);
160	if (IS_ERR(node))
161	return node;
162
163	if (!tree->free_nodes)
164	panic("FIXME!!!");
165	tree->free_nodes--;
166	prev->next = idx;
167	cnid = cpu_to_be32(idx);
168	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
169
170	node->type = HFS_NODE_MAP;
171	node->num_recs = 1;
172	hfs_bnode_clear(node, 0, tree->node_size);
173	desc.next = 0;
174	desc.prev = 0;
175	desc.type = HFS_NODE_MAP;
176	desc.height = 0;
177	desc.num_recs = cpu_to_be16(1);
178	desc.reserved = 0;
179	hfs_bnode_write(node, &desc, 0, sizeof(desc));
180	hfs_bnode_write_u16(node, 14, 0x8000);
181	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
182	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
183
184	return node;
185	}
186
187	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
188	{
189	struct hfs_bnode node, next_node;
190	struct page **pagep;
191	u32 nidx, idx;
192	u16 off, len;
193	u8 *data, byte, m;
194	int i;
195
196	while (!tree->free_nodes) {
197	struct inode *inode = tree->inode;
198	u32 count;
199	int res;
200
201	res = hfs_extend_file(inode);
202	if (res)
203	return ERR_PTR(res);
204	HFS_I(inode)->phys_size = inode->i_size =
205	(loff_t)HFS_I(inode)->alloc_blocks *
206	HFS_SB(tree->sb)->alloc_blksz;
207	HFS_I(inode)->fs_blocks = inode->i_size >>
208	tree->sb->s_blocksize_bits;
209	inode_set_bytes(inode, inode->i_size);
210	count = inode->i_size >> tree->node_size_shift;
211	tree->free_nodes = count - tree->node_count;
212	tree->node_count = count;
213	}
214
215	nidx = 0;
216	node = hfs_bnode_find(tree, nidx);
217	if (IS_ERR(node))
218	return node;
219	len = hfs_brec_lenoff(node, 2, &off);
220
221	off += node->page_offset;
222	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
223	data = kmap(*pagep);
224	off &= ~PAGE_CACHE_MASK;
225	idx = 0;
226
227	for (;;) {
228	while (len) {
229	byte = data[off];
230	if (byte != 0xff) {
231	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
232	if (!(byte & m)) {
233	idx += i;
234	data[off] \|= m;
235	set_page_dirty(*pagep);
236	kunmap(*pagep);
237	tree->free_nodes--;
238	mark_inode_dirty(tree->inode);
239	hfs_bnode_put(node);
240	return hfs_bnode_create(tree, idx);
241	}
242	}
243	}
244	if (++off >= PAGE_CACHE_SIZE) {
245	kunmap(*pagep);
246	data = kmap(*++pagep);
247	off = 0;
248	}
249	idx += 8;
250	len--;
251	}
252	kunmap(*pagep);
253	nidx = node->next;
254	if (!nidx) {
255	printk("create new bmap node...\n");
256	next_node = hfs_bmap_new_bmap(node, idx);
257	} else
258	next_node = hfs_bnode_find(tree, nidx);
259	hfs_bnode_put(node);
260	if (IS_ERR(next_node))
261	return next_node;
262	node = next_node;
263
264	len = hfs_brec_lenoff(node, 0, &off);
265	off += node->page_offset;
266	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
267	data = kmap(*pagep);
268	off &= ~PAGE_CACHE_MASK;
269	}
270	}
271
272	void hfs_bmap_free(struct hfs_bnode *node)
273	{
274	struct hfs_btree *tree;
275	struct page *page;
276	u16 off, len;
277	u32 nidx;
278	u8 *data, byte, m;
279
280	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
281	tree = node->tree;
282	nidx = node->this;
283	node = hfs_bnode_find(tree, 0);
284	if (IS_ERR(node))
285	return;
286	len = hfs_brec_lenoff(node, 2, &off);
287	while (nidx >= len * 8) {
288	u32 i;
289
290	nidx -= len * 8;
291	i = node->next;
292	hfs_bnode_put(node);
293	if (!i) {
294	/* panic */;
295	printk("HFS: unable to free bnode %u. bmap not found!\n", node->this);
296	return;
297	}
298	node = hfs_bnode_find(tree, i);
299	if (IS_ERR(node))
300	return;
301	if (node->type != HFS_NODE_MAP) {
302	/* panic */;
303	printk("HFS: invalid bmap found! (%u,%d)\n", node->this, node->type);
304	hfs_bnode_put(node);
305	return;
306	}
307	len = hfs_brec_lenoff(node, 0, &off);
308	}
309	off += node->page_offset + nidx / 8;
310	page = node->page[off >> PAGE_CACHE_SHIFT];
311	data = kmap(page);
312	off &= ~PAGE_CACHE_MASK;
313	m = 1 << (~nidx & 7);
314	byte = data[off];
315	if (!(byte & m)) {
316	printk("HFS: trying to free free bnode %u(%d)\n", node->this, node->type);
317	kunmap(page);
318	hfs_bnode_put(node);
319	return;
320	}
321	data[off] = byte & ~m;
322	set_page_dirty(page);
323	kunmap(page);
324	hfs_bnode_put(node);
325	tree->free_nodes++;
326	mark_inode_dirty(tree->inode);
327	}