5 * Brad Boyer (flar@allandria.com)
6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 * Handle opening/closing btree
11 #include <linux/pagemap.h>
15 /* Get a reference to a B*Tree and do some initial checks */
16 struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
18 struct hfs_btree *tree;
19 struct hfs_btree_header_rec *head;
20 struct address_space *mapping;
22 unsigned int shift, size;
24 tree = kmalloc(sizeof(*tree), GFP_KERNEL);
27 memset(tree, 0, sizeof(*tree));
29 init_MUTEX(&tree->tree_lock);
30 spin_lock_init(&tree->hash_lock);
31 /* Set the correct compare function */
34 tree->keycmp = keycmp;
36 tree->inode = iget_locked(sb, id);
39 if (!(tree->inode->i_state & I_NEW))
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);
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;
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;
60 unlock_new_inode(tree->inode);
62 mapping = tree->inode->i_mapping;
63 page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL);
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);
80 size = tree->node_size;
81 if (!size || size & (size - 1))
83 if (!tree->node_count)
85 for (shift = 0; size >>= 1; shift += 1)
87 tree->node_size_shift = shift;
89 tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
92 page_cache_release(page);
96 tree->inode->i_mapping->a_ops = &hfs_aops;
97 page_cache_release(page);
104 /* Release resources used by a btree */
105 void hfs_btree_close(struct hfs_btree *tree)
107 struct hfs_bnode *node;
113 for (i = 0; i < NODE_HASH_SIZE; i++) {
114 while ((node = tree->node_hash[i])) {
115 tree->node_hash[i] = node->next_hash;
116 if (atomic_read(&node->refcnt))
117 printk("HFS: node %d:%d still has %d user(s)!\n",
118 node->tree->cnid, node->this, atomic_read(&node->refcnt));
119 hfs_bnode_free(node);
120 tree->node_hash_cnt--;
127 void hfs_btree_write(struct hfs_btree *tree)
129 struct hfs_btree_header_rec *head;
130 struct hfs_bnode *node;
133 node = hfs_bnode_find(tree, 0);
137 /* Load the header */
138 page = node->page[0];
139 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
141 head->root = cpu_to_be32(tree->root);
142 head->leaf_count = cpu_to_be32(tree->leaf_count);
143 head->leaf_head = cpu_to_be32(tree->leaf_head);
144 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
145 head->node_count = cpu_to_be32(tree->node_count);
146 head->free_nodes = cpu_to_be32(tree->free_nodes);
147 head->attributes = cpu_to_be32(tree->attributes);
148 head->depth = cpu_to_be16(tree->depth);
151 set_page_dirty(page);
155 static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
157 struct hfs_btree *tree = prev->tree;
158 struct hfs_bnode *node;
159 struct hfs_bnode_desc desc;
162 node = hfs_bnode_create(tree, idx);
166 if (!tree->free_nodes)
170 cnid = cpu_to_be32(idx);
171 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
173 node->type = HFS_NODE_MAP;
175 hfs_bnode_clear(node, 0, tree->node_size);
178 desc.type = HFS_NODE_MAP;
180 desc.num_recs = cpu_to_be16(1);
182 hfs_bnode_write(node, &desc, 0, sizeof(desc));
183 hfs_bnode_write_u16(node, 14, 0x8000);
184 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
185 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
190 struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
192 struct hfs_bnode *node, *next_node;
199 while (!tree->free_nodes) {
200 struct inode *inode = tree->inode;
204 res = hfs_extend_file(inode);
207 inode->i_blocks = HFS_I(inode)->alloc_blocks *
208 HFS_SB(tree->sb)->fs_div;
209 HFS_I(inode)->phys_size = inode->i_size =
210 (loff_t)inode->i_blocks << tree->sb->s_blocksize_bits;
211 count = inode->i_size >> tree->node_size_shift;
212 tree->free_nodes = count - tree->node_count;
213 tree->node_count = count;
217 node = hfs_bnode_find(tree, nidx);
220 len = hfs_brec_lenoff(node, 2, &off);
222 off += node->page_offset;
223 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
225 off &= ~PAGE_CACHE_MASK;
232 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
236 set_page_dirty(*pagep);
239 mark_inode_dirty(tree->inode);
241 return hfs_bnode_create(tree, idx);
245 if (++off >= PAGE_CACHE_SIZE) {
247 data = kmap(*++pagep);
256 printk("create new bmap node...\n");
257 next_node = hfs_bmap_new_bmap(node, idx);
259 next_node = hfs_bnode_find(tree, nidx);
261 if (IS_ERR(next_node))
265 len = hfs_brec_lenoff(node, 0, &off);
266 off += node->page_offset;
267 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
269 off &= ~PAGE_CACHE_MASK;
273 void hfs_bmap_free(struct hfs_bnode *node)
275 struct hfs_btree *tree;
281 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
284 node = hfs_bnode_find(tree, 0);
287 len = hfs_brec_lenoff(node, 2, &off);
288 while (nidx >= len * 8) {
296 printk("HFS: unable to free bnode %u. bmap not found!\n", node->this);
299 node = hfs_bnode_find(tree, i);
302 if (node->type != HFS_NODE_MAP) {
304 printk("HFS: invalid bmap found! (%u,%d)\n", node->this, node->type);
308 len = hfs_brec_lenoff(node, 0, &off);
310 off += node->page_offset + nidx / 8;
311 page = node->page[off >> PAGE_CACHE_SHIFT];
313 off &= ~PAGE_CACHE_MASK;
314 m = 1 << (~nidx & 7);
317 printk("HFS: trying to free free bnode %u(%d)\n", node->this, node->type);
322 data[off] = byte & ~m;
323 set_page_dirty(page);
327 mark_inode_dirty(tree->inode);