Linux 3.8-rc7
[cris-mirror.git] / fs / hfs / btree.c
blob1cbdeea1db4441b21c386458046d0b080101bafb
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/slab.h>
13 #include <linux/log2.h>
15 #include "btree.h"
17 /* Get a reference to a B*Tree and do some initial checks */
18 struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
20 struct hfs_btree *tree;
21 struct hfs_btree_header_rec *head;
22 struct address_space *mapping;
23 struct page *page;
24 unsigned int size;
26 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
27 if (!tree)
28 return NULL;
30 mutex_init(&tree->tree_lock);
31 spin_lock_init(&tree->hash_lock);
32 /* Set the correct compare function */
33 tree->sb = sb;
34 tree->cnid = id;
35 tree->keycmp = keycmp;
37 tree->inode = iget_locked(sb, id);
38 if (!tree->inode)
39 goto free_tree;
40 BUG_ON(!(tree->inode->i_state & I_NEW));
42 struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
43 HFS_I(tree->inode)->flags = 0;
44 mutex_init(&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 if (HFS_I(tree->inode)->alloc_blocks >
50 HFS_I(tree->inode)->first_blocks) {
51 printk(KERN_ERR "hfs: invalid btree extent records\n");
52 unlock_new_inode(tree->inode);
53 goto free_inode;
56 tree->inode->i_mapping->a_ops = &hfs_btree_aops;
57 break;
58 case HFS_CAT_CNID:
59 hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
60 mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
62 if (!HFS_I(tree->inode)->first_blocks) {
63 printk(KERN_ERR "hfs: invalid btree extent records "
64 "(0 size).\n");
65 unlock_new_inode(tree->inode);
66 goto free_inode;
69 tree->inode->i_mapping->a_ops = &hfs_btree_aops;
70 break;
71 default:
72 BUG();
75 unlock_new_inode(tree->inode);
77 mapping = tree->inode->i_mapping;
78 page = read_mapping_page(mapping, 0, NULL);
79 if (IS_ERR(page))
80 goto free_inode;
82 /* Load the header */
83 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
84 tree->root = be32_to_cpu(head->root);
85 tree->leaf_count = be32_to_cpu(head->leaf_count);
86 tree->leaf_head = be32_to_cpu(head->leaf_head);
87 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
88 tree->node_count = be32_to_cpu(head->node_count);
89 tree->free_nodes = be32_to_cpu(head->free_nodes);
90 tree->attributes = be32_to_cpu(head->attributes);
91 tree->node_size = be16_to_cpu(head->node_size);
92 tree->max_key_len = be16_to_cpu(head->max_key_len);
93 tree->depth = be16_to_cpu(head->depth);
95 size = tree->node_size;
96 if (!is_power_of_2(size))
97 goto fail_page;
98 if (!tree->node_count)
99 goto fail_page;
100 switch (id) {
101 case HFS_EXT_CNID:
102 if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
103 printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
104 tree->max_key_len);
105 goto fail_page;
107 break;
108 case HFS_CAT_CNID:
109 if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
110 printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
111 tree->max_key_len);
112 goto fail_page;
114 break;
115 default:
116 BUG();
119 tree->node_size_shift = ffs(size) - 1;
120 tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
122 kunmap(page);
123 page_cache_release(page);
124 return tree;
126 fail_page:
127 page_cache_release(page);
128 free_inode:
129 tree->inode->i_mapping->a_ops = &hfs_aops;
130 iput(tree->inode);
131 free_tree:
132 kfree(tree);
133 return NULL;
136 /* Release resources used by a btree */
137 void hfs_btree_close(struct hfs_btree *tree)
139 struct hfs_bnode *node;
140 int i;
142 if (!tree)
143 return;
145 for (i = 0; i < NODE_HASH_SIZE; i++) {
146 while ((node = tree->node_hash[i])) {
147 tree->node_hash[i] = node->next_hash;
148 if (atomic_read(&node->refcnt))
149 printk(KERN_ERR "hfs: node %d:%d still has %d user(s)!\n",
150 node->tree->cnid, node->this, atomic_read(&node->refcnt));
151 hfs_bnode_free(node);
152 tree->node_hash_cnt--;
155 iput(tree->inode);
156 kfree(tree);
159 void hfs_btree_write(struct hfs_btree *tree)
161 struct hfs_btree_header_rec *head;
162 struct hfs_bnode *node;
163 struct page *page;
165 node = hfs_bnode_find(tree, 0);
166 if (IS_ERR(node))
167 /* panic? */
168 return;
169 /* Load the header */
170 page = node->page[0];
171 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
173 head->root = cpu_to_be32(tree->root);
174 head->leaf_count = cpu_to_be32(tree->leaf_count);
175 head->leaf_head = cpu_to_be32(tree->leaf_head);
176 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
177 head->node_count = cpu_to_be32(tree->node_count);
178 head->free_nodes = cpu_to_be32(tree->free_nodes);
179 head->attributes = cpu_to_be32(tree->attributes);
180 head->depth = cpu_to_be16(tree->depth);
182 kunmap(page);
183 set_page_dirty(page);
184 hfs_bnode_put(node);
187 static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
189 struct hfs_btree *tree = prev->tree;
190 struct hfs_bnode *node;
191 struct hfs_bnode_desc desc;
192 __be32 cnid;
194 node = hfs_bnode_create(tree, idx);
195 if (IS_ERR(node))
196 return node;
198 if (!tree->free_nodes)
199 panic("FIXME!!!");
200 tree->free_nodes--;
201 prev->next = idx;
202 cnid = cpu_to_be32(idx);
203 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
205 node->type = HFS_NODE_MAP;
206 node->num_recs = 1;
207 hfs_bnode_clear(node, 0, tree->node_size);
208 desc.next = 0;
209 desc.prev = 0;
210 desc.type = HFS_NODE_MAP;
211 desc.height = 0;
212 desc.num_recs = cpu_to_be16(1);
213 desc.reserved = 0;
214 hfs_bnode_write(node, &desc, 0, sizeof(desc));
215 hfs_bnode_write_u16(node, 14, 0x8000);
216 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
217 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
219 return node;
222 struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
224 struct hfs_bnode *node, *next_node;
225 struct page **pagep;
226 u32 nidx, idx;
227 unsigned off;
228 u16 off16;
229 u16 len;
230 u8 *data, byte, m;
231 int i;
233 while (!tree->free_nodes) {
234 struct inode *inode = tree->inode;
235 u32 count;
236 int res;
238 res = hfs_extend_file(inode);
239 if (res)
240 return ERR_PTR(res);
241 HFS_I(inode)->phys_size = inode->i_size =
242 (loff_t)HFS_I(inode)->alloc_blocks *
243 HFS_SB(tree->sb)->alloc_blksz;
244 HFS_I(inode)->fs_blocks = inode->i_size >>
245 tree->sb->s_blocksize_bits;
246 inode_set_bytes(inode, inode->i_size);
247 count = inode->i_size >> tree->node_size_shift;
248 tree->free_nodes = count - tree->node_count;
249 tree->node_count = count;
252 nidx = 0;
253 node = hfs_bnode_find(tree, nidx);
254 if (IS_ERR(node))
255 return node;
256 len = hfs_brec_lenoff(node, 2, &off16);
257 off = off16;
259 off += node->page_offset;
260 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
261 data = kmap(*pagep);
262 off &= ~PAGE_CACHE_MASK;
263 idx = 0;
265 for (;;) {
266 while (len) {
267 byte = data[off];
268 if (byte != 0xff) {
269 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
270 if (!(byte & m)) {
271 idx += i;
272 data[off] |= m;
273 set_page_dirty(*pagep);
274 kunmap(*pagep);
275 tree->free_nodes--;
276 mark_inode_dirty(tree->inode);
277 hfs_bnode_put(node);
278 return hfs_bnode_create(tree, idx);
282 if (++off >= PAGE_CACHE_SIZE) {
283 kunmap(*pagep);
284 data = kmap(*++pagep);
285 off = 0;
287 idx += 8;
288 len--;
290 kunmap(*pagep);
291 nidx = node->next;
292 if (!nidx) {
293 printk(KERN_DEBUG "hfs: create new bmap node...\n");
294 next_node = hfs_bmap_new_bmap(node, idx);
295 } else
296 next_node = hfs_bnode_find(tree, nidx);
297 hfs_bnode_put(node);
298 if (IS_ERR(next_node))
299 return next_node;
300 node = next_node;
302 len = hfs_brec_lenoff(node, 0, &off16);
303 off = off16;
304 off += node->page_offset;
305 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
306 data = kmap(*pagep);
307 off &= ~PAGE_CACHE_MASK;
311 void hfs_bmap_free(struct hfs_bnode *node)
313 struct hfs_btree *tree;
314 struct page *page;
315 u16 off, len;
316 u32 nidx;
317 u8 *data, byte, m;
319 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
320 tree = node->tree;
321 nidx = node->this;
322 node = hfs_bnode_find(tree, 0);
323 if (IS_ERR(node))
324 return;
325 len = hfs_brec_lenoff(node, 2, &off);
326 while (nidx >= len * 8) {
327 u32 i;
329 nidx -= len * 8;
330 i = node->next;
331 hfs_bnode_put(node);
332 if (!i) {
333 /* panic */;
334 printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
335 return;
337 node = hfs_bnode_find(tree, i);
338 if (IS_ERR(node))
339 return;
340 if (node->type != HFS_NODE_MAP) {
341 /* panic */;
342 printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
343 hfs_bnode_put(node);
344 return;
346 len = hfs_brec_lenoff(node, 0, &off);
348 off += node->page_offset + nidx / 8;
349 page = node->page[off >> PAGE_CACHE_SHIFT];
350 data = kmap(page);
351 off &= ~PAGE_CACHE_MASK;
352 m = 1 << (~nidx & 7);
353 byte = data[off];
354 if (!(byte & m)) {
355 printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
356 kunmap(page);
357 hfs_bnode_put(node);
358 return;
360 data[off] = byte & ~m;
361 set_page_dirty(page);
362 kunmap(page);
363 hfs_bnode_put(node);
364 tree->free_nodes++;
365 mark_inode_dirty(tree->inode);