1
2
3
4
5
6
7
8
9
10
11#include <linux/slab.h>
12#include <linux/pagemap.h>
13#include <linux/log2.h>
14
15#include "hfsplus_fs.h"
16#include "hfsplus_raw.h"
17
18
19
20struct 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 inode *inode;
26 struct page *page;
27 unsigned int size;
28
29 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
30 if (!tree)
31 return NULL;
32
33 mutex_init(&tree->tree_lock);
34 spin_lock_init(&tree->hash_lock);
35 tree->sb = sb;
36 tree->cnid = id;
37 inode = hfsplus_iget(sb, id);
38 if (IS_ERR(inode))
39 goto free_tree;
40 tree->inode = inode;
41
42 if (!HFSPLUS_I(tree->inode)->first_blocks) {
43 printk(KERN_ERR
44 "hfs: invalid btree extent records (0 size).\n");
45 goto free_inode;
46 }
47
48 mapping = tree->inode->i_mapping;
49 page = read_mapping_page(mapping, 0, NULL);
50 if (IS_ERR(page))
51 goto free_inode;
52
53
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);
66
67
68 switch (id) {
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",
72 tree->max_key_len);
73 goto fail_page;
74 }
75 if (tree->attributes & HFS_TREE_VARIDXKEYS) {
76 printk(KERN_ERR "hfs: invalid extent btree flag\n");
77 goto fail_page;
78 }
79
80 tree->keycmp = hfsplus_ext_cmp_key;
81 break;
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",
85 tree->max_key_len);
86 goto fail_page;
87 }
88 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
89 printk(KERN_ERR "hfs: invalid catalog btree flag\n");
90 goto fail_page;
91 }
92
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;
96 else {
97 tree->keycmp = hfsplus_cat_case_cmp_key;
98 set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
99 }
100 break;
101 default:
102 printk(KERN_ERR "hfs: unknown B*Tree requested\n");
103 goto fail_page;
104 }
105
106 if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
107 printk(KERN_ERR "hfs: invalid btree flag\n");
108 goto fail_page;
109 }
110
111 size = tree->node_size;
112 if (!is_power_of_2(size))
113 goto fail_page;
114 if (!tree->node_count)
115 goto fail_page;
116
117 tree->node_size_shift = ffs(size) - 1;
118
119 tree->pages_per_bnode =
120 (tree->node_size + PAGE_CACHE_SIZE - 1) >>
121 PAGE_CACHE_SHIFT;
122
123 kunmap(page);
124 page_cache_release(page);
125 return tree;
126
127 fail_page:
128 page_cache_release(page);
129 free_inode:
130 tree->inode->i_mapping->a_ops = &hfsplus_aops;
131 iput(tree->inode);
132 free_tree:
133 kfree(tree);
134 return NULL;
135}
136
137
138void hfs_btree_close(struct hfs_btree *tree)
139{
140 struct hfs_bnode *node;
141 int i;
142
143 if (!tree)
144 return;
145
146 for (i = 0; i < NODE_HASH_SIZE; i++) {
147 while ((node = tree->node_hash[i])) {
148 tree->node_hash[i] = node->next_hash;
149 if (atomic_read(&node->refcnt))
150 printk(KERN_CRIT "hfs: node %d:%d "
151 "still has %d user(s)!\n",
152 node->tree->cnid, node->this,
153 atomic_read(&node->refcnt));
154 hfs_bnode_free(node);
155 tree->node_hash_cnt--;
156 }
157 }
158 iput(tree->inode);
159 kfree(tree);
160}
161
162void hfs_btree_write(struct hfs_btree *tree)
163{
164 struct hfs_btree_header_rec *head;
165 struct hfs_bnode *node;
166 struct page *page;
167
168 node = hfs_bnode_find(tree, 0);
169 if (IS_ERR(node))
170
171 return;
172
173 page = node->page[0];
174 head = (struct hfs_btree_header_rec *)(kmap(page) +
175 sizeof(struct hfs_bnode_desc));
176
177 head->root = cpu_to_be32(tree->root);
178 head->leaf_count = cpu_to_be32(tree->leaf_count);
179 head->leaf_head = cpu_to_be32(tree->leaf_head);
180 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
181 head->node_count = cpu_to_be32(tree->node_count);
182 head->free_nodes = cpu_to_be32(tree->free_nodes);
183 head->attributes = cpu_to_be32(tree->attributes);
184 head->depth = cpu_to_be16(tree->depth);
185
186 kunmap(page);
187 set_page_dirty(page);
188 hfs_bnode_put(node);
189}
190
191static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
192{
193 struct hfs_btree *tree = prev->tree;
194 struct hfs_bnode *node;
195 struct hfs_bnode_desc desc;
196 __be32 cnid;
197
198 node = hfs_bnode_create(tree, idx);
199 if (IS_ERR(node))
200 return node;
201
202 tree->free_nodes--;
203 prev->next = idx;
204 cnid = cpu_to_be32(idx);
205 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
206
207 node->type = HFS_NODE_MAP;
208 node->num_recs = 1;
209 hfs_bnode_clear(node, 0, tree->node_size);
210 desc.next = 0;
211 desc.prev = 0;
212 desc.type = HFS_NODE_MAP;
213 desc.height = 0;
214 desc.num_recs = cpu_to_be16(1);
215 desc.reserved = 0;
216 hfs_bnode_write(node, &desc, 0, sizeof(desc));
217 hfs_bnode_write_u16(node, 14, 0x8000);
218 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
219 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
220
221 return node;
222}
223
224struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
225{
226 struct hfs_bnode *node, *next_node;
227 struct page **pagep;
228 u32 nidx, idx;
229 unsigned off;
230 u16 off16;
231 u16 len;
232 u8 *data, byte, m;
233 int i;
234
235 while (!tree->free_nodes) {
236 struct inode *inode = tree->inode;
237 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
238 u32 count;
239 int res;
240
241 res = hfsplus_file_extend(inode);
242 if (res)
243 return ERR_PTR(res);
244 hip->phys_size = inode->i_size =
245 (loff_t)hip->alloc_blocks <<
246 HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
247 hip->fs_blocks =
248 hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
249 inode_set_bytes(inode, inode->i_size);
250 count = inode->i_size >> tree->node_size_shift;
251 tree->free_nodes = count - tree->node_count;
252 tree->node_count = count;
253 }
254
255 nidx = 0;
256 node = hfs_bnode_find(tree, nidx);
257 if (IS_ERR(node))
258 return node;
259 len = hfs_brec_lenoff(node, 2, &off16);
260 off = off16;
261
262 off += node->page_offset;
263 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
264 data = kmap(*pagep);
265 off &= ~PAGE_CACHE_MASK;
266 idx = 0;
267
268 for (;;) {
269 while (len) {
270 byte = data[off];
271 if (byte != 0xff) {
272 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
273 if (!(byte & m)) {
274 idx += i;
275 data[off] |= m;
276 set_page_dirty(*pagep);
277 kunmap(*pagep);
278 tree->free_nodes--;
279 mark_inode_dirty(tree->inode);
280 hfs_bnode_put(node);
281 return hfs_bnode_create(tree,
282 idx);
283 }
284 }
285 }
286 if (++off >= PAGE_CACHE_SIZE) {
287 kunmap(*pagep);
288 data = kmap(*++pagep);
289 off = 0;
290 }
291 idx += 8;
292 len--;
293 }
294 kunmap(*pagep);
295 nidx = node->next;
296 if (!nidx) {
297 dprint(DBG_BNODE_MOD, "hfs: create new bmap node.\n");
298 next_node = hfs_bmap_new_bmap(node, idx);
299 } else
300 next_node = hfs_bnode_find(tree, nidx);
301 hfs_bnode_put(node);
302 if (IS_ERR(next_node))
303 return next_node;
304 node = next_node;
305
306 len = hfs_brec_lenoff(node, 0, &off16);
307 off = off16;
308 off += node->page_offset;
309 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
310 data = kmap(*pagep);
311 off &= ~PAGE_CACHE_MASK;
312 }
313}
314
315void hfs_bmap_free(struct hfs_bnode *node)
316{
317 struct hfs_btree *tree;
318 struct page *page;
319 u16 off, len;
320 u32 nidx;
321 u8 *data, byte, m;
322
323 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
324 BUG_ON(!node->this);
325 tree = node->tree;
326 nidx = node->this;
327 node = hfs_bnode_find(tree, 0);
328 if (IS_ERR(node))
329 return;
330 len = hfs_brec_lenoff(node, 2, &off);
331 while (nidx >= len * 8) {
332 u32 i;
333
334 nidx -= len * 8;
335 i = node->next;
336 hfs_bnode_put(node);
337 if (!i) {
338 ;
339 printk(KERN_CRIT "hfs: unable to free bnode %u. "
340 "bmap not found!\n",
341 node->this);
342 return;
343 }
344 node = hfs_bnode_find(tree, i);
345 if (IS_ERR(node))
346 return;
347 if (node->type != HFS_NODE_MAP) {
348 ;
349 printk(KERN_CRIT "hfs: invalid bmap found! "
350 "(%u,%d)\n",
351 node->this, node->type);
352 hfs_bnode_put(node);
353 return;
354 }
355 len = hfs_brec_lenoff(node, 0, &off);
356 }
357 off += node->page_offset + nidx / 8;
358 page = node->page[off >> PAGE_CACHE_SHIFT];
359 data = kmap(page);
360 off &= ~PAGE_CACHE_MASK;
361 m = 1 << (~nidx & 7);
362 byte = data[off];
363 if (!(byte & m)) {
364 printk(KERN_CRIT "hfs: trying to free free bnode "
365 "%u(%d)\n",
366 node->this, node->type);
367 kunmap(page);
368 hfs_bnode_put(node);
369 return;
370 }
371 data[off] = byte & ~m;
372 set_page_dirty(page);
373 kunmap(page);
374 hfs_bnode_put(node);
375 tree->free_nodes++;
376 mark_inode_dirty(tree->inode);
377}
378
