2 * linux/fs/hfsplus/btree.c
5 * Brad Boyer (flar@allandria.com)
6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 * Handle opening/closing btree
11 #include <linux/slab.h>
12 #include <linux/pagemap.h>
13 #include <linux/log2.h>
15 #include "hfsplus_fs.h"
16 #include "hfsplus_raw.h"
19 /* Get a reference to a B*Tree and do some initial checks */
20 struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id)
22 struct hfs_btree *tree;
23 struct hfs_btree_header_rec *head;
24 struct address_space *mapping;
29 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
33 mutex_init(&tree->tree_lock);
34 spin_lock_init(&tree->hash_lock);
37 inode = hfsplus_iget(sb, id);
42 if (!HFSPLUS_I(tree->inode)->first_blocks) {
44 "hfs: invalid btree extent records (0 size).\n");
48 mapping = tree->inode->i_mapping;
49 page = read_mapping_page(mapping, 0, NULL);
54 head = (struct hfs_btree_header_rec *)(kmap(page) +
55 sizeof(struct hfs_bnode_desc));
56 tree->root = be32_to_cpu(head->root);
57 tree->leaf_count = be32_to_cpu(head->leaf_count);
58 tree->leaf_head = be32_to_cpu(head->leaf_head);
59 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
60 tree->node_count = be32_to_cpu(head->node_count);
61 tree->free_nodes = be32_to_cpu(head->free_nodes);
62 tree->attributes = be32_to_cpu(head->attributes);
63 tree->node_size = be16_to_cpu(head->node_size);
64 tree->max_key_len = be16_to_cpu(head->max_key_len);
65 tree->depth = be16_to_cpu(head->depth);
67 /* Verify the tree and set the correct compare function */
69 case HFSPLUS_EXT_CNID:
70 if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
71 printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
75 if (tree->attributes & HFS_TREE_VARIDXKEYS) {
76 printk(KERN_ERR "hfs: invalid extent btree flag\n");
80 tree->keycmp = hfsplus_ext_cmp_key;
82 case HFSPLUS_CAT_CNID:
83 if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
84 printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
88 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
89 printk(KERN_ERR "hfs: invalid catalog btree flag\n");
93 if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
94 (head->key_type == HFSPLUS_KEY_BINARY))
95 tree->keycmp = hfsplus_cat_bin_cmp_key;
97 tree->keycmp = hfsplus_cat_case_cmp_key;
98 set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
101 case HFSPLUS_ATTR_CNID:
102 if (tree->max_key_len != HFSPLUS_ATTR_KEYLEN - sizeof(u16)) {
103 printk(KERN_ERR "hfs: invalid attributes max_key_len %d\n",
107 tree->keycmp = hfsplus_attr_bin_cmp_key;
110 printk(KERN_ERR "hfs: unknown B*Tree requested\n");
114 if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
115 printk(KERN_ERR "hfs: invalid btree flag\n");
119 size = tree->node_size;
120 if (!is_power_of_2(size))
122 if (!tree->node_count)
125 tree->node_size_shift = ffs(size) - 1;
127 tree->pages_per_bnode =
128 (tree->node_size + PAGE_CACHE_SIZE - 1) >>
132 page_cache_release(page);
136 page_cache_release(page);
138 tree->inode->i_mapping->a_ops = &hfsplus_aops;
145 /* Release resources used by a btree */
146 void hfs_btree_close(struct hfs_btree *tree)
148 struct hfs_bnode *node;
154 for (i = 0; i < NODE_HASH_SIZE; i++) {
155 while ((node = tree->node_hash[i])) {
156 tree->node_hash[i] = node->next_hash;
157 if (atomic_read(&node->refcnt))
158 printk(KERN_CRIT "hfs: node %d:%d "
159 "still has %d user(s)!\n",
160 node->tree->cnid, node->this,
161 atomic_read(&node->refcnt));
162 hfs_bnode_free(node);
163 tree->node_hash_cnt--;
170 void hfs_btree_write(struct hfs_btree *tree)
172 struct hfs_btree_header_rec *head;
173 struct hfs_bnode *node;
176 node = hfs_bnode_find(tree, 0);
180 /* Load the header */
181 page = node->page[0];
182 head = (struct hfs_btree_header_rec *)(kmap(page) +
183 sizeof(struct hfs_bnode_desc));
185 head->root = cpu_to_be32(tree->root);
186 head->leaf_count = cpu_to_be32(tree->leaf_count);
187 head->leaf_head = cpu_to_be32(tree->leaf_head);
188 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
189 head->node_count = cpu_to_be32(tree->node_count);
190 head->free_nodes = cpu_to_be32(tree->free_nodes);
191 head->attributes = cpu_to_be32(tree->attributes);
192 head->depth = cpu_to_be16(tree->depth);
195 set_page_dirty(page);
199 static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
201 struct hfs_btree *tree = prev->tree;
202 struct hfs_bnode *node;
203 struct hfs_bnode_desc desc;
206 node = hfs_bnode_create(tree, idx);
212 cnid = cpu_to_be32(idx);
213 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
215 node->type = HFS_NODE_MAP;
217 hfs_bnode_clear(node, 0, tree->node_size);
220 desc.type = HFS_NODE_MAP;
222 desc.num_recs = cpu_to_be16(1);
224 hfs_bnode_write(node, &desc, 0, sizeof(desc));
225 hfs_bnode_write_u16(node, 14, 0x8000);
226 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
227 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
232 struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
234 struct hfs_bnode *node, *next_node;
243 while (!tree->free_nodes) {
244 struct inode *inode = tree->inode;
245 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
249 res = hfsplus_file_extend(inode);
252 hip->phys_size = inode->i_size =
253 (loff_t)hip->alloc_blocks <<
254 HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
256 hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
257 inode_set_bytes(inode, inode->i_size);
258 count = inode->i_size >> tree->node_size_shift;
259 tree->free_nodes = count - tree->node_count;
260 tree->node_count = count;
264 node = hfs_bnode_find(tree, nidx);
267 len = hfs_brec_lenoff(node, 2, &off16);
270 off += node->page_offset;
271 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
273 off &= ~PAGE_CACHE_MASK;
280 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
284 set_page_dirty(*pagep);
287 mark_inode_dirty(tree->inode);
289 return hfs_bnode_create(tree,
294 if (++off >= PAGE_CACHE_SIZE) {
296 data = kmap(*++pagep);
305 dprint(DBG_BNODE_MOD, "hfs: create new bmap node.\n");
306 next_node = hfs_bmap_new_bmap(node, idx);
308 next_node = hfs_bnode_find(tree, nidx);
310 if (IS_ERR(next_node))
314 len = hfs_brec_lenoff(node, 0, &off16);
316 off += node->page_offset;
317 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
319 off &= ~PAGE_CACHE_MASK;
323 void hfs_bmap_free(struct hfs_bnode *node)
325 struct hfs_btree *tree;
331 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
335 node = hfs_bnode_find(tree, 0);
338 len = hfs_brec_lenoff(node, 2, &off);
339 while (nidx >= len * 8) {
347 printk(KERN_CRIT "hfs: unable to free bnode %u. "
352 node = hfs_bnode_find(tree, i);
355 if (node->type != HFS_NODE_MAP) {
357 printk(KERN_CRIT "hfs: invalid bmap found! "
359 node->this, node->type);
363 len = hfs_brec_lenoff(node, 0, &off);
365 off += node->page_offset + nidx / 8;
366 page = node->page[off >> PAGE_CACHE_SHIFT];
368 off &= ~PAGE_CACHE_MASK;
369 m = 1 << (~nidx & 7);
372 printk(KERN_CRIT "hfs: trying to free free bnode "
374 node->this, node->type);
379 data[off] = byte & ~m;
380 set_page_dirty(page);
384 mark_inode_dirty(tree->inode);