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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/hfs/btree.c | |
3 | * | |
4 | * Copyright (C) 2001 | |
5 | * Brad Boyer (flar@allandria.com) | |
6 | * (C) 2003 Ardis Technologies <roman@ardistech.com> | |
7 | * | |
8 | * Handle opening/closing btree | |
9 | */ | |
10 | ||
11 | #include <linux/pagemap.h> | |
5a0e3ad6 | 12 | #include <linux/slab.h> |
e1b5c1d3 | 13 | #include <linux/log2.h> |
1da177e4 LT |
14 | |
15 | #include "btree.h" | |
16 | ||
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) | |
19 | { | |
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; | |
25 | ||
f8314dc6 | 26 | tree = kzalloc(sizeof(*tree), GFP_KERNEL); |
1da177e4 LT |
27 | if (!tree) |
28 | return NULL; | |
1da177e4 LT |
29 | |
30 | init_MUTEX(&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; | |
36 | ||
37 | tree->inode = iget_locked(sb, id); | |
38 | if (!tree->inode) | |
39 | goto free_tree; | |
4d4ef9ab | 40 | BUG_ON(!(tree->inode->i_state & I_NEW)); |
1da177e4 LT |
41 | { |
42 | struct hfs_mdb *mdb = HFS_SB(sb)->mdb; | |
43 | HFS_I(tree->inode)->flags = 0; | |
39f8d472 | 44 | mutex_init(&HFS_I(tree->inode)->extents_lock); |
1da177e4 LT |
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 | tree->inode->i_mapping->a_ops = &hfs_btree_aops; | |
50 | break; | |
51 | case HFS_CAT_CNID: | |
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; | |
55 | break; | |
56 | default: | |
57 | BUG(); | |
58 | } | |
59 | } | |
60 | unlock_new_inode(tree->inode); | |
61 | ||
47f365eb JM |
62 | if (!HFS_I(tree->inode)->first_blocks) { |
63 | printk(KERN_ERR "hfs: invalid btree extent records (0 size).\n"); | |
64 | goto free_inode; | |
65 | } | |
66 | ||
1da177e4 | 67 | mapping = tree->inode->i_mapping; |
090d2b18 | 68 | page = read_mapping_page(mapping, 0, NULL); |
1da177e4 | 69 | if (IS_ERR(page)) |
46a39c1c | 70 | goto free_inode; |
1da177e4 LT |
71 | |
72 | /* Load the header */ | |
73 | head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); | |
74 | tree->root = be32_to_cpu(head->root); | |
75 | tree->leaf_count = be32_to_cpu(head->leaf_count); | |
76 | tree->leaf_head = be32_to_cpu(head->leaf_head); | |
77 | tree->leaf_tail = be32_to_cpu(head->leaf_tail); | |
78 | tree->node_count = be32_to_cpu(head->node_count); | |
79 | tree->free_nodes = be32_to_cpu(head->free_nodes); | |
80 | tree->attributes = be32_to_cpu(head->attributes); | |
81 | tree->node_size = be16_to_cpu(head->node_size); | |
82 | tree->max_key_len = be16_to_cpu(head->max_key_len); | |
83 | tree->depth = be16_to_cpu(head->depth); | |
84 | ||
85 | size = tree->node_size; | |
e1b5c1d3 | 86 | if (!is_power_of_2(size)) |
1da177e4 LT |
87 | goto fail_page; |
88 | if (!tree->node_count) | |
89 | goto fail_page; | |
55581d01 ES |
90 | switch (id) { |
91 | case HFS_EXT_CNID: | |
92 | if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) { | |
93 | printk(KERN_ERR "hfs: invalid extent max_key_len %d\n", | |
94 | tree->max_key_len); | |
95 | goto fail_page; | |
96 | } | |
97 | break; | |
98 | case HFS_CAT_CNID: | |
99 | if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) { | |
100 | printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n", | |
101 | tree->max_key_len); | |
102 | goto fail_page; | |
103 | } | |
104 | break; | |
105 | default: | |
106 | BUG(); | |
cf059462 ES |
107 | } |
108 | ||
1da177e4 LT |
109 | tree->node_size_shift = ffs(size) - 1; |
110 | tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
111 | ||
112 | kunmap(page); | |
113 | page_cache_release(page); | |
114 | return tree; | |
115 | ||
46a39c1c | 116 | fail_page: |
1da177e4 | 117 | page_cache_release(page); |
46a39c1c | 118 | free_inode: |
cf059462 | 119 | tree->inode->i_mapping->a_ops = &hfs_aops; |
1da177e4 | 120 | iput(tree->inode); |
46a39c1c | 121 | free_tree: |
1da177e4 LT |
122 | kfree(tree); |
123 | return NULL; | |
124 | } | |
125 | ||
126 | /* Release resources used by a btree */ | |
127 | void hfs_btree_close(struct hfs_btree *tree) | |
128 | { | |
129 | struct hfs_bnode *node; | |
130 | int i; | |
131 | ||
132 | if (!tree) | |
133 | return; | |
134 | ||
135 | for (i = 0; i < NODE_HASH_SIZE; i++) { | |
136 | while ((node = tree->node_hash[i])) { | |
137 | tree->node_hash[i] = node->next_hash; | |
138 | if (atomic_read(&node->refcnt)) | |
7cf3cc30 | 139 | printk(KERN_ERR "hfs: node %d:%d still has %d user(s)!\n", |
1da177e4 LT |
140 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
141 | hfs_bnode_free(node); | |
142 | tree->node_hash_cnt--; | |
143 | } | |
144 | } | |
145 | iput(tree->inode); | |
146 | kfree(tree); | |
147 | } | |
148 | ||
149 | void hfs_btree_write(struct hfs_btree *tree) | |
150 | { | |
151 | struct hfs_btree_header_rec *head; | |
152 | struct hfs_bnode *node; | |
153 | struct page *page; | |
154 | ||
155 | node = hfs_bnode_find(tree, 0); | |
156 | if (IS_ERR(node)) | |
157 | /* panic? */ | |
158 | return; | |
159 | /* Load the header */ | |
160 | page = node->page[0]; | |
161 | head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); | |
162 | ||
163 | head->root = cpu_to_be32(tree->root); | |
164 | head->leaf_count = cpu_to_be32(tree->leaf_count); | |
165 | head->leaf_head = cpu_to_be32(tree->leaf_head); | |
166 | head->leaf_tail = cpu_to_be32(tree->leaf_tail); | |
167 | head->node_count = cpu_to_be32(tree->node_count); | |
168 | head->free_nodes = cpu_to_be32(tree->free_nodes); | |
169 | head->attributes = cpu_to_be32(tree->attributes); | |
170 | head->depth = cpu_to_be16(tree->depth); | |
171 | ||
172 | kunmap(page); | |
173 | set_page_dirty(page); | |
174 | hfs_bnode_put(node); | |
175 | } | |
176 | ||
177 | static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx) | |
178 | { | |
179 | struct hfs_btree *tree = prev->tree; | |
180 | struct hfs_bnode *node; | |
181 | struct hfs_bnode_desc desc; | |
182 | __be32 cnid; | |
183 | ||
184 | node = hfs_bnode_create(tree, idx); | |
185 | if (IS_ERR(node)) | |
186 | return node; | |
187 | ||
188 | if (!tree->free_nodes) | |
189 | panic("FIXME!!!"); | |
190 | tree->free_nodes--; | |
191 | prev->next = idx; | |
192 | cnid = cpu_to_be32(idx); | |
193 | hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4); | |
194 | ||
195 | node->type = HFS_NODE_MAP; | |
196 | node->num_recs = 1; | |
197 | hfs_bnode_clear(node, 0, tree->node_size); | |
198 | desc.next = 0; | |
199 | desc.prev = 0; | |
200 | desc.type = HFS_NODE_MAP; | |
201 | desc.height = 0; | |
202 | desc.num_recs = cpu_to_be16(1); | |
203 | desc.reserved = 0; | |
204 | hfs_bnode_write(node, &desc, 0, sizeof(desc)); | |
205 | hfs_bnode_write_u16(node, 14, 0x8000); | |
206 | hfs_bnode_write_u16(node, tree->node_size - 2, 14); | |
207 | hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6); | |
208 | ||
209 | return node; | |
210 | } | |
211 | ||
212 | struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) | |
213 | { | |
214 | struct hfs_bnode *node, *next_node; | |
215 | struct page **pagep; | |
216 | u32 nidx, idx; | |
3e5a5097 AM |
217 | unsigned off; |
218 | u16 off16; | |
219 | u16 len; | |
1da177e4 LT |
220 | u8 *data, byte, m; |
221 | int i; | |
222 | ||
223 | while (!tree->free_nodes) { | |
224 | struct inode *inode = tree->inode; | |
225 | u32 count; | |
226 | int res; | |
227 | ||
228 | res = hfs_extend_file(inode); | |
229 | if (res) | |
230 | return ERR_PTR(res); | |
231 | HFS_I(inode)->phys_size = inode->i_size = | |
232 | (loff_t)HFS_I(inode)->alloc_blocks * | |
233 | HFS_SB(tree->sb)->alloc_blksz; | |
234 | HFS_I(inode)->fs_blocks = inode->i_size >> | |
235 | tree->sb->s_blocksize_bits; | |
236 | inode_set_bytes(inode, inode->i_size); | |
237 | count = inode->i_size >> tree->node_size_shift; | |
238 | tree->free_nodes = count - tree->node_count; | |
239 | tree->node_count = count; | |
240 | } | |
241 | ||
242 | nidx = 0; | |
243 | node = hfs_bnode_find(tree, nidx); | |
244 | if (IS_ERR(node)) | |
245 | return node; | |
3e5a5097 AM |
246 | len = hfs_brec_lenoff(node, 2, &off16); |
247 | off = off16; | |
1da177e4 LT |
248 | |
249 | off += node->page_offset; | |
250 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | |
251 | data = kmap(*pagep); | |
252 | off &= ~PAGE_CACHE_MASK; | |
253 | idx = 0; | |
254 | ||
255 | for (;;) { | |
256 | while (len) { | |
257 | byte = data[off]; | |
258 | if (byte != 0xff) { | |
259 | for (m = 0x80, i = 0; i < 8; m >>= 1, i++) { | |
260 | if (!(byte & m)) { | |
261 | idx += i; | |
262 | data[off] |= m; | |
263 | set_page_dirty(*pagep); | |
264 | kunmap(*pagep); | |
265 | tree->free_nodes--; | |
266 | mark_inode_dirty(tree->inode); | |
267 | hfs_bnode_put(node); | |
268 | return hfs_bnode_create(tree, idx); | |
269 | } | |
270 | } | |
271 | } | |
272 | if (++off >= PAGE_CACHE_SIZE) { | |
273 | kunmap(*pagep); | |
274 | data = kmap(*++pagep); | |
275 | off = 0; | |
276 | } | |
277 | idx += 8; | |
278 | len--; | |
279 | } | |
280 | kunmap(*pagep); | |
281 | nidx = node->next; | |
282 | if (!nidx) { | |
7cf3cc30 | 283 | printk(KERN_DEBUG "hfs: create new bmap node...\n"); |
1da177e4 LT |
284 | next_node = hfs_bmap_new_bmap(node, idx); |
285 | } else | |
286 | next_node = hfs_bnode_find(tree, nidx); | |
287 | hfs_bnode_put(node); | |
288 | if (IS_ERR(next_node)) | |
289 | return next_node; | |
290 | node = next_node; | |
291 | ||
3e5a5097 AM |
292 | len = hfs_brec_lenoff(node, 0, &off16); |
293 | off = off16; | |
1da177e4 LT |
294 | off += node->page_offset; |
295 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | |
296 | data = kmap(*pagep); | |
297 | off &= ~PAGE_CACHE_MASK; | |
298 | } | |
299 | } | |
300 | ||
301 | void hfs_bmap_free(struct hfs_bnode *node) | |
302 | { | |
303 | struct hfs_btree *tree; | |
304 | struct page *page; | |
305 | u16 off, len; | |
306 | u32 nidx; | |
307 | u8 *data, byte, m; | |
308 | ||
309 | dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this); | |
310 | tree = node->tree; | |
311 | nidx = node->this; | |
312 | node = hfs_bnode_find(tree, 0); | |
313 | if (IS_ERR(node)) | |
314 | return; | |
315 | len = hfs_brec_lenoff(node, 2, &off); | |
316 | while (nidx >= len * 8) { | |
317 | u32 i; | |
318 | ||
319 | nidx -= len * 8; | |
320 | i = node->next; | |
321 | hfs_bnode_put(node); | |
322 | if (!i) { | |
323 | /* panic */; | |
7cf3cc30 | 324 | printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this); |
1da177e4 LT |
325 | return; |
326 | } | |
327 | node = hfs_bnode_find(tree, i); | |
328 | if (IS_ERR(node)) | |
329 | return; | |
330 | if (node->type != HFS_NODE_MAP) { | |
331 | /* panic */; | |
7cf3cc30 | 332 | printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type); |
1da177e4 LT |
333 | hfs_bnode_put(node); |
334 | return; | |
335 | } | |
336 | len = hfs_brec_lenoff(node, 0, &off); | |
337 | } | |
338 | off += node->page_offset + nidx / 8; | |
339 | page = node->page[off >> PAGE_CACHE_SHIFT]; | |
340 | data = kmap(page); | |
341 | off &= ~PAGE_CACHE_MASK; | |
342 | m = 1 << (~nidx & 7); | |
343 | byte = data[off]; | |
344 | if (!(byte & m)) { | |
7cf3cc30 | 345 | printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type); |
1da177e4 LT |
346 | kunmap(page); |
347 | hfs_bnode_put(node); | |
348 | return; | |
349 | } | |
350 | data[off] = byte & ~m; | |
351 | set_page_dirty(page); | |
352 | kunmap(page); | |
353 | hfs_bnode_put(node); | |
354 | tree->free_nodes++; | |
355 | mark_inode_dirty(tree->inode); | |
356 | } |