Linux 2.6.28.1
[linux/fpc-iii.git] / fs / hfs / btree.c
blob9b9d6395bad36127b04a67b8048d149e2bc89d3a
1 /*
2 * linux/fs/hfs/btree.c
4 * Copyright (C) 2001
5 * Brad Boyer (flar@allandria.com)
6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 * Handle opening/closing btree
9 */
11 #include <linux/pagemap.h>
12 #include <linux/log2.h>
14 #include "btree.h"
16 /* Get a reference to a B*Tree and do some initial checks */
17 struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
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;
25 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
26 if (!tree)
27 return NULL;
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;
36 tree->inode = iget_locked(sb, id);
37 if (!tree->inode)
38 goto free_tree;
39 BUG_ON(!(tree->inode->i_state & I_NEW));
41 struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
42 HFS_I(tree->inode)->flags = 0;
43 mutex_init(&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();
59 unlock_new_inode(tree->inode);
61 mapping = tree->inode->i_mapping;
62 page = read_mapping_page(mapping, 0, NULL);
63 if (IS_ERR(page))
64 goto free_inode;
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);
79 size = tree->node_size;
80 if (!is_power_of_2(size))
81 goto fail_page;
82 if (!tree->node_count)
83 goto fail_page;
84 switch (id) {
85 case HFS_EXT_CNID:
86 if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
87 printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
88 tree->max_key_len);
89 goto fail_page;
91 break;
92 case HFS_CAT_CNID:
93 if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
94 printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
95 tree->max_key_len);
96 goto fail_page;
98 break;
99 default:
100 BUG();
103 tree->node_size_shift = ffs(size) - 1;
104 tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
106 kunmap(page);
107 page_cache_release(page);
108 return tree;
110 fail_page:
111 page_cache_release(page);
112 free_inode:
113 tree->inode->i_mapping->a_ops = &hfs_aops;
114 iput(tree->inode);
115 free_tree:
116 kfree(tree);
117 return NULL;
120 /* Release resources used by a btree */
121 void hfs_btree_close(struct hfs_btree *tree)
123 struct hfs_bnode *node;
124 int i;
126 if (!tree)
127 return;
129 for (i = 0; i < NODE_HASH_SIZE; i++) {
130 while ((node = tree->node_hash[i])) {
131 tree->node_hash[i] = node->next_hash;
132 if (atomic_read(&node->refcnt))
133 printk(KERN_ERR "hfs: node %d:%d still has %d user(s)!\n",
134 node->tree->cnid, node->this, atomic_read(&node->refcnt));
135 hfs_bnode_free(node);
136 tree->node_hash_cnt--;
139 iput(tree->inode);
140 kfree(tree);
143 void hfs_btree_write(struct hfs_btree *tree)
145 struct hfs_btree_header_rec *head;
146 struct hfs_bnode *node;
147 struct page *page;
149 node = hfs_bnode_find(tree, 0);
150 if (IS_ERR(node))
151 /* panic? */
152 return;
153 /* Load the header */
154 page = node->page[0];
155 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
157 head->root = cpu_to_be32(tree->root);
158 head->leaf_count = cpu_to_be32(tree->leaf_count);
159 head->leaf_head = cpu_to_be32(tree->leaf_head);
160 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
161 head->node_count = cpu_to_be32(tree->node_count);
162 head->free_nodes = cpu_to_be32(tree->free_nodes);
163 head->attributes = cpu_to_be32(tree->attributes);
164 head->depth = cpu_to_be16(tree->depth);
166 kunmap(page);
167 set_page_dirty(page);
168 hfs_bnode_put(node);
171 static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
173 struct hfs_btree *tree = prev->tree;
174 struct hfs_bnode *node;
175 struct hfs_bnode_desc desc;
176 __be32 cnid;
178 node = hfs_bnode_create(tree, idx);
179 if (IS_ERR(node))
180 return node;
182 if (!tree->free_nodes)
183 panic("FIXME!!!");
184 tree->free_nodes--;
185 prev->next = idx;
186 cnid = cpu_to_be32(idx);
187 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
189 node->type = HFS_NODE_MAP;
190 node->num_recs = 1;
191 hfs_bnode_clear(node, 0, tree->node_size);
192 desc.next = 0;
193 desc.prev = 0;
194 desc.type = HFS_NODE_MAP;
195 desc.height = 0;
196 desc.num_recs = cpu_to_be16(1);
197 desc.reserved = 0;
198 hfs_bnode_write(node, &desc, 0, sizeof(desc));
199 hfs_bnode_write_u16(node, 14, 0x8000);
200 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
201 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
203 return node;
206 struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
208 struct hfs_bnode *node, *next_node;
209 struct page **pagep;
210 u32 nidx, idx;
211 unsigned off;
212 u16 off16;
213 u16 len;
214 u8 *data, byte, m;
215 int i;
217 while (!tree->free_nodes) {
218 struct inode *inode = tree->inode;
219 u32 count;
220 int res;
222 res = hfs_extend_file(inode);
223 if (res)
224 return ERR_PTR(res);
225 HFS_I(inode)->phys_size = inode->i_size =
226 (loff_t)HFS_I(inode)->alloc_blocks *
227 HFS_SB(tree->sb)->alloc_blksz;
228 HFS_I(inode)->fs_blocks = inode->i_size >>
229 tree->sb->s_blocksize_bits;
230 inode_set_bytes(inode, inode->i_size);
231 count = inode->i_size >> tree->node_size_shift;
232 tree->free_nodes = count - tree->node_count;
233 tree->node_count = count;
236 nidx = 0;
237 node = hfs_bnode_find(tree, nidx);
238 if (IS_ERR(node))
239 return node;
240 len = hfs_brec_lenoff(node, 2, &off16);
241 off = off16;
243 off += node->page_offset;
244 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
245 data = kmap(*pagep);
246 off &= ~PAGE_CACHE_MASK;
247 idx = 0;
249 for (;;) {
250 while (len) {
251 byte = data[off];
252 if (byte != 0xff) {
253 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
254 if (!(byte & m)) {
255 idx += i;
256 data[off] |= m;
257 set_page_dirty(*pagep);
258 kunmap(*pagep);
259 tree->free_nodes--;
260 mark_inode_dirty(tree->inode);
261 hfs_bnode_put(node);
262 return hfs_bnode_create(tree, idx);
266 if (++off >= PAGE_CACHE_SIZE) {
267 kunmap(*pagep);
268 data = kmap(*++pagep);
269 off = 0;
271 idx += 8;
272 len--;
274 kunmap(*pagep);
275 nidx = node->next;
276 if (!nidx) {
277 printk(KERN_DEBUG "hfs: create new bmap node...\n");
278 next_node = hfs_bmap_new_bmap(node, idx);
279 } else
280 next_node = hfs_bnode_find(tree, nidx);
281 hfs_bnode_put(node);
282 if (IS_ERR(next_node))
283 return next_node;
284 node = next_node;
286 len = hfs_brec_lenoff(node, 0, &off16);
287 off = off16;
288 off += node->page_offset;
289 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
290 data = kmap(*pagep);
291 off &= ~PAGE_CACHE_MASK;
295 void hfs_bmap_free(struct hfs_bnode *node)
297 struct hfs_btree *tree;
298 struct page *page;
299 u16 off, len;
300 u32 nidx;
301 u8 *data, byte, m;
303 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
304 tree = node->tree;
305 nidx = node->this;
306 node = hfs_bnode_find(tree, 0);
307 if (IS_ERR(node))
308 return;
309 len = hfs_brec_lenoff(node, 2, &off);
310 while (nidx >= len * 8) {
311 u32 i;
313 nidx -= len * 8;
314 i = node->next;
315 hfs_bnode_put(node);
316 if (!i) {
317 /* panic */;
318 printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
319 return;
321 node = hfs_bnode_find(tree, i);
322 if (IS_ERR(node))
323 return;
324 if (node->type != HFS_NODE_MAP) {
325 /* panic */;
326 printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
327 hfs_bnode_put(node);
328 return;
330 len = hfs_brec_lenoff(node, 0, &off);
332 off += node->page_offset + nidx / 8;
333 page = node->page[off >> PAGE_CACHE_SHIFT];
334 data = kmap(page);
335 off &= ~PAGE_CACHE_MASK;
336 m = 1 << (~nidx & 7);
337 byte = data[off];
338 if (!(byte & m)) {
339 printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
340 kunmap(page);
341 hfs_bnode_put(node);
342 return;
344 data[off] = byte & ~m;
345 set_page_dirty(page);
346 kunmap(page);
347 hfs_bnode_put(node);
348 tree->free_nodes++;
349 mark_inode_dirty(tree->inode);