[mirror_ubuntu-zesty-kernel.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 <linux/log2.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 = kzalloc(sizeof(*tree), GFP_KERNEL);
	if (!tree)
		return NULL;

	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;
			HFSPLUS_SB(sb).flags |= HFSPLUS_SB_CASEFOLD;
		}
	} else {
		printk(KERN_ERR "hfs: unknown B*Tree requested\n");
		goto fail_page;
	}

	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 = &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>
e1b5c1d3	13	#include <linux/log2.h>
1da177e4 LT	14
	15	#include "hfsplus_fs.h"
	16	#include "hfsplus_raw.h"
	17
	18
	19	/* Get a reference to a BTree and do some initial checks /
	20	struct hfs_btree hfs_btree_open(struct super_block sb, u32 id)
	21	{
	22	struct hfs_btree *tree;
	23	struct hfs_btree_header_rec *head;
	24	struct address_space *mapping;
	25	struct page *page;
	26	unsigned int size;
	27
f8314dc6	28	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
1da177e4 LT	29	if (!tree)
1da177e4 LT	30	return NULL;
1da177e4 LT	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;
d45bce8f	65	else {
2179d372	66	tree->keycmp = hfsplus_cat_case_cmp_key;
d45bce8f DG	67	HFSPLUS_SB(sb).flags \|= HFSPLUS_SB_CASEFOLD;
d45bce8f DG	68	}
2179d372 DE	69	} else {
	70	printk(KERN_ERR "hfs: unknown B*Tree requested\n");
	71	goto fail_page;
	72	}
	73
1da177e4	74	size = tree->node_size;
e1b5c1d3	75	if (!is_power_of_2(size))
1da177e4 LT	76	goto fail_page;
	77	if (!tree->node_count)
	78	goto fail_page;
	79	tree->node_size_shift = ffs(size) - 1;
	80
	81	tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
	82
	83	kunmap(page);
	84	page_cache_release(page);
	85	return tree;
	86
	87	fail_page:
	88	tree->inode->i_mapping->a_ops = &hfsplus_aops;
	89	page_cache_release(page);
	90	free_tree:
	91	iput(tree->inode);
	92	kfree(tree);
	93	return NULL;
	94	}
	95
	96	/* Release resources used by a btree */
	97	void hfs_btree_close(struct hfs_btree *tree)
	98	{
	99	struct hfs_bnode *node;
	100	int i;
	101
	102	if (!tree)
	103	return;
	104
	105	for (i = 0; i < NODE_HASH_SIZE; i++) {
	106	while ((node = tree->node_hash[i])) {
	107	tree->node_hash[i] = node->next_hash;
	108	if (atomic_read(&node->refcnt))
634725a9	109	printk(KERN_CRIT "hfs: node %d:%d still has %d user(s)!\n",
1da177e4 LT	110	node->tree->cnid, node->this, atomic_read(&node->refcnt));
	111	hfs_bnode_free(node);
	112	tree->node_hash_cnt--;
	113	}
	114	}
	115	iput(tree->inode);
	116	kfree(tree);
	117	}
	118
	119	void hfs_btree_write(struct hfs_btree *tree)
	120	{
	121	struct hfs_btree_header_rec *head;
	122	struct hfs_bnode *node;
	123	struct page *page;
	124
	125	node = hfs_bnode_find(tree, 0);
	126	if (IS_ERR(node))
	127	/* panic? */
	128	return;
	129	/* Load the header */
	130	page = node->page[0];
	131	head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
	132
	133	head->root = cpu_to_be32(tree->root);
	134	head->leaf_count = cpu_to_be32(tree->leaf_count);
	135	head->leaf_head = cpu_to_be32(tree->leaf_head);
	136	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
	137	head->node_count = cpu_to_be32(tree->node_count);
	138	head->free_nodes = cpu_to_be32(tree->free_nodes);
	139	head->attributes = cpu_to_be32(tree->attributes);
	140	head->depth = cpu_to_be16(tree->depth);
	141
	142	kunmap(page);
	143	set_page_dirty(page);
	144	hfs_bnode_put(node);
	145	}
	146
	147	static struct hfs_bnode hfs_bmap_new_bmap(struct hfs_bnode prev, u32 idx)
	148	{
	149	struct hfs_btree *tree = prev->tree;
	150	struct hfs_bnode *node;
	151	struct hfs_bnode_desc desc;
	152	__be32 cnid;
	153
	154	node = hfs_bnode_create(tree, idx);
	155	if (IS_ERR(node))
	156	return node;
	157
	158	tree->free_nodes--;
	159	prev->next = idx;
	160	cnid = cpu_to_be32(idx);
	161	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
	162
	163	node->type = HFS_NODE_MAP;
	164	node->num_recs = 1;
	165	hfs_bnode_clear(node, 0, tree->node_size);
	166	desc.next = 0;
	167	desc.prev = 0;
	168	desc.type = HFS_NODE_MAP;
	169	desc.height = 0;
	170	desc.num_recs = cpu_to_be16(1);
	171	desc.reserved = 0;
	172	hfs_bnode_write(node, &desc, 0, sizeof(desc));
	173	hfs_bnode_write_u16(node, 14, 0x8000);
174	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
175	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
176
177	return node;
178	}
179
180	struct hfs_bnode hfs_bmap_alloc(struct hfs_btree tree)
181	{
182	struct hfs_bnode node, next_node;
183	struct page **pagep;
184	u32 nidx, idx;
185	u16 off, len;
186	u8 *data, byte, m;
187	int i;
188
189	while (!tree->free_nodes) {
190	struct inode *inode = tree->inode;
191	u32 count;
192	int res;
193
194	res = hfsplus_file_extend(inode);
195	if (res)
196	return ERR_PTR(res);
197	HFSPLUS_I(inode).phys_size = inode->i_size =
198	(loff_t)HFSPLUS_I(inode).alloc_blocks <<
199	HFSPLUS_SB(tree->sb).alloc_blksz_shift;
200	HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).alloc_blocks <<
201	HFSPLUS_SB(tree->sb).fs_shift;
202	inode_set_bytes(inode, inode->i_size);
203	count = inode->i_size >> tree->node_size_shift;
204	tree->free_nodes = count - tree->node_count;
205	tree->node_count = count;
206	}
207
208	nidx = 0;
209	node = hfs_bnode_find(tree, nidx);
210	if (IS_ERR(node))
211	return node;
212	len = hfs_brec_lenoff(node, 2, &off);
213
214	off += node->page_offset;
215	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
216	data = kmap(*pagep);
217	off &= ~PAGE_CACHE_MASK;
218	idx = 0;
219
220	for (;;) {
221	while (len) {
222	byte = data[off];
223	if (byte != 0xff) {
224	for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
225	if (!(byte & m)) {
226	idx += i;
227	data[off] \|= m;
228	set_page_dirty(*pagep);
229	kunmap(*pagep);
230	tree->free_nodes--;
231	mark_inode_dirty(tree->inode);
232	hfs_bnode_put(node);
1da177e4 LT	233	return hfs_bnode_create(tree, idx);
	234	}
	235	}
	236	}
	237	if (++off >= PAGE_CACHE_SIZE) {
	238	kunmap(*pagep);
	239	data = kmap(*++pagep);
	240	off = 0;
	241	}
	242	idx += 8;
	243	len--;
	244	}
	245	kunmap(*pagep);
	246	nidx = node->next;
	247	if (!nidx) {
634725a9	248	printk(KERN_DEBUG "hfs: create new bmap node...\n");
1da177e4 LT	249	next_node = hfs_bmap_new_bmap(node, idx);
	250	} else
	251	next_node = hfs_bnode_find(tree, nidx);
	252	hfs_bnode_put(node);
	253	if (IS_ERR(next_node))
	254	return next_node;
	255	node = next_node;
	256
	257	len = hfs_brec_lenoff(node, 0, &off);
	258	off += node->page_offset;
	259	pagep = node->page + (off >> PAGE_CACHE_SHIFT);
	260	data = kmap(*pagep);
	261	off &= ~PAGE_CACHE_MASK;
	262	}
	263	}
	264
	265	void hfs_bmap_free(struct hfs_bnode *node)
	266	{
	267	struct hfs_btree *tree;
	268	struct page *page;
	269	u16 off, len;
	270	u32 nidx;
	271	u8 *data, byte, m;
	272
	273	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
0bf3ba53	274	BUG_ON(!node->this);
1da177e4 LT	275	tree = node->tree;
	276	nidx = node->this;
	277	node = hfs_bnode_find(tree, 0);
	278	if (IS_ERR(node))
	279	return;
	280	len = hfs_brec_lenoff(node, 2, &off);
	281	while (nidx >= len * 8) {
	282	u32 i;
	283
	284	nidx -= len * 8;
	285	i = node->next;
	286	hfs_bnode_put(node);
	287	if (!i) {
	288	/* panic */;
634725a9	289	printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
1da177e4 LT	290	return;
	291	}
	292	node = hfs_bnode_find(tree, i);
	293	if (IS_ERR(node))
	294	return;
	295	if (node->type != HFS_NODE_MAP) {
	296	/* panic */;
634725a9	297	printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
1da177e4 LT	298	hfs_bnode_put(node);
	299	return;
	300	}
	301	len = hfs_brec_lenoff(node, 0, &off);
	302	}
	303	off += node->page_offset + nidx / 8;
	304	page = node->page[off >> PAGE_CACHE_SHIFT];
	305	data = kmap(page);
	306	off &= ~PAGE_CACHE_MASK;
	307	m = 1 << (~nidx & 7);
	308	byte = data[off];
	309	if (!(byte & m)) {
634725a9	310	printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
1da177e4 LT	311	kunmap(page);
	312	hfs_bnode_put(node);
	313	return;
	314	}
	315	data[off] = byte & ~m;
	316	set_page_dirty(page);
	317	kunmap(page);
	318	hfs_bnode_put(node);
	319	tree->free_nodes++;
	320	mark_inode_dirty(tree->inode);
	321	}