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> | |
e1b5c1d3 | 12 | #include <linux/log2.h> |
1da177e4 LT |
13 | |
14 | #include "btree.h" | |
15 | ||
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) | |
18 | { | |
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; | |
24 | ||
f8314dc6 | 25 | tree = kzalloc(sizeof(*tree), GFP_KERNEL); |
1da177e4 LT |
26 | if (!tree) |
27 | return NULL; | |
1da177e4 LT |
28 | |
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; | |
35 | ||
36 | tree->inode = iget_locked(sb, id); | |
37 | if (!tree->inode) | |
38 | goto free_tree; | |
4d4ef9ab | 39 | BUG_ON(!(tree->inode->i_state & I_NEW)); |
1da177e4 LT |
40 | { |
41 | struct hfs_mdb *mdb = HFS_SB(sb)->mdb; | |
42 | HFS_I(tree->inode)->flags = 0; | |
43 | init_MUTEX(&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(); | |
57 | } | |
58 | } | |
59 | unlock_new_inode(tree->inode); | |
60 | ||
61 | mapping = tree->inode->i_mapping; | |
090d2b18 | 62 | page = read_mapping_page(mapping, 0, NULL); |
1da177e4 LT |
63 | if (IS_ERR(page)) |
64 | goto free_tree; | |
65 | ||
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); | |
78 | ||
79 | size = tree->node_size; | |
e1b5c1d3 | 80 | if (!is_power_of_2(size)) |
1da177e4 LT |
81 | goto fail_page; |
82 | if (!tree->node_count) | |
83 | goto fail_page; | |
84 | tree->node_size_shift = ffs(size) - 1; | |
85 | tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
86 | ||
87 | kunmap(page); | |
88 | page_cache_release(page); | |
89 | return tree; | |
90 | ||
91 | fail_page: | |
92 | tree->inode->i_mapping->a_ops = &hfs_aops; | |
93 | page_cache_release(page); | |
94 | free_tree: | |
95 | iput(tree->inode); | |
96 | kfree(tree); | |
97 | return NULL; | |
98 | } | |
99 | ||
100 | /* Release resources used by a btree */ | |
101 | void hfs_btree_close(struct hfs_btree *tree) | |
102 | { | |
103 | struct hfs_bnode *node; | |
104 | int i; | |
105 | ||
106 | if (!tree) | |
107 | return; | |
108 | ||
109 | for (i = 0; i < NODE_HASH_SIZE; i++) { | |
110 | while ((node = tree->node_hash[i])) { | |
111 | tree->node_hash[i] = node->next_hash; | |
112 | if (atomic_read(&node->refcnt)) | |
7cf3cc30 | 113 | printk(KERN_ERR "hfs: node %d:%d still has %d user(s)!\n", |
1da177e4 LT |
114 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
115 | hfs_bnode_free(node); | |
116 | tree->node_hash_cnt--; | |
117 | } | |
118 | } | |
119 | iput(tree->inode); | |
120 | kfree(tree); | |
121 | } | |
122 | ||
123 | void hfs_btree_write(struct hfs_btree *tree) | |
124 | { | |
125 | struct hfs_btree_header_rec *head; | |
126 | struct hfs_bnode *node; | |
127 | struct page *page; | |
128 | ||
129 | node = hfs_bnode_find(tree, 0); | |
130 | if (IS_ERR(node)) | |
131 | /* panic? */ | |
132 | return; | |
133 | /* Load the header */ | |
134 | page = node->page[0]; | |
135 | head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); | |
136 | ||
137 | head->root = cpu_to_be32(tree->root); | |
138 | head->leaf_count = cpu_to_be32(tree->leaf_count); | |
139 | head->leaf_head = cpu_to_be32(tree->leaf_head); | |
140 | head->leaf_tail = cpu_to_be32(tree->leaf_tail); | |
141 | head->node_count = cpu_to_be32(tree->node_count); | |
142 | head->free_nodes = cpu_to_be32(tree->free_nodes); | |
143 | head->attributes = cpu_to_be32(tree->attributes); | |
144 | head->depth = cpu_to_be16(tree->depth); | |
145 | ||
146 | kunmap(page); | |
147 | set_page_dirty(page); | |
148 | hfs_bnode_put(node); | |
149 | } | |
150 | ||
151 | static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx) | |
152 | { | |
153 | struct hfs_btree *tree = prev->tree; | |
154 | struct hfs_bnode *node; | |
155 | struct hfs_bnode_desc desc; | |
156 | __be32 cnid; | |
157 | ||
158 | node = hfs_bnode_create(tree, idx); | |
159 | if (IS_ERR(node)) | |
160 | return node; | |
161 | ||
162 | if (!tree->free_nodes) | |
163 | panic("FIXME!!!"); | |
164 | tree->free_nodes--; | |
165 | prev->next = idx; | |
166 | cnid = cpu_to_be32(idx); | |
167 | hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4); | |
168 | ||
169 | node->type = HFS_NODE_MAP; | |
170 | node->num_recs = 1; | |
171 | hfs_bnode_clear(node, 0, tree->node_size); | |
172 | desc.next = 0; | |
173 | desc.prev = 0; | |
174 | desc.type = HFS_NODE_MAP; | |
175 | desc.height = 0; | |
176 | desc.num_recs = cpu_to_be16(1); | |
177 | desc.reserved = 0; | |
178 | hfs_bnode_write(node, &desc, 0, sizeof(desc)); | |
179 | hfs_bnode_write_u16(node, 14, 0x8000); | |
180 | hfs_bnode_write_u16(node, tree->node_size - 2, 14); | |
181 | hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6); | |
182 | ||
183 | return node; | |
184 | } | |
185 | ||
186 | struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) | |
187 | { | |
188 | struct hfs_bnode *node, *next_node; | |
189 | struct page **pagep; | |
190 | u32 nidx, idx; | |
191 | u16 off, len; | |
192 | u8 *data, byte, m; | |
193 | int i; | |
194 | ||
195 | while (!tree->free_nodes) { | |
196 | struct inode *inode = tree->inode; | |
197 | u32 count; | |
198 | int res; | |
199 | ||
200 | res = hfs_extend_file(inode); | |
201 | if (res) | |
202 | return ERR_PTR(res); | |
203 | HFS_I(inode)->phys_size = inode->i_size = | |
204 | (loff_t)HFS_I(inode)->alloc_blocks * | |
205 | HFS_SB(tree->sb)->alloc_blksz; | |
206 | HFS_I(inode)->fs_blocks = inode->i_size >> | |
207 | tree->sb->s_blocksize_bits; | |
208 | inode_set_bytes(inode, inode->i_size); | |
209 | count = inode->i_size >> tree->node_size_shift; | |
210 | tree->free_nodes = count - tree->node_count; | |
211 | tree->node_count = count; | |
212 | } | |
213 | ||
214 | nidx = 0; | |
215 | node = hfs_bnode_find(tree, nidx); | |
216 | if (IS_ERR(node)) | |
217 | return node; | |
218 | len = hfs_brec_lenoff(node, 2, &off); | |
219 | ||
220 | off += node->page_offset; | |
221 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | |
222 | data = kmap(*pagep); | |
223 | off &= ~PAGE_CACHE_MASK; | |
224 | idx = 0; | |
225 | ||
226 | for (;;) { | |
227 | while (len) { | |
228 | byte = data[off]; | |
229 | if (byte != 0xff) { | |
230 | for (m = 0x80, i = 0; i < 8; m >>= 1, i++) { | |
231 | if (!(byte & m)) { | |
232 | idx += i; | |
233 | data[off] |= m; | |
234 | set_page_dirty(*pagep); | |
235 | kunmap(*pagep); | |
236 | tree->free_nodes--; | |
237 | mark_inode_dirty(tree->inode); | |
238 | hfs_bnode_put(node); | |
239 | return hfs_bnode_create(tree, idx); | |
240 | } | |
241 | } | |
242 | } | |
243 | if (++off >= PAGE_CACHE_SIZE) { | |
244 | kunmap(*pagep); | |
245 | data = kmap(*++pagep); | |
246 | off = 0; | |
247 | } | |
248 | idx += 8; | |
249 | len--; | |
250 | } | |
251 | kunmap(*pagep); | |
252 | nidx = node->next; | |
253 | if (!nidx) { | |
7cf3cc30 | 254 | printk(KERN_DEBUG "hfs: create new bmap node...\n"); |
1da177e4 LT |
255 | next_node = hfs_bmap_new_bmap(node, idx); |
256 | } else | |
257 | next_node = hfs_bnode_find(tree, nidx); | |
258 | hfs_bnode_put(node); | |
259 | if (IS_ERR(next_node)) | |
260 | return next_node; | |
261 | node = next_node; | |
262 | ||
263 | len = hfs_brec_lenoff(node, 0, &off); | |
264 | off += node->page_offset; | |
265 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | |
266 | data = kmap(*pagep); | |
267 | off &= ~PAGE_CACHE_MASK; | |
268 | } | |
269 | } | |
270 | ||
271 | void hfs_bmap_free(struct hfs_bnode *node) | |
272 | { | |
273 | struct hfs_btree *tree; | |
274 | struct page *page; | |
275 | u16 off, len; | |
276 | u32 nidx; | |
277 | u8 *data, byte, m; | |
278 | ||
279 | dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this); | |
280 | tree = node->tree; | |
281 | nidx = node->this; | |
282 | node = hfs_bnode_find(tree, 0); | |
283 | if (IS_ERR(node)) | |
284 | return; | |
285 | len = hfs_brec_lenoff(node, 2, &off); | |
286 | while (nidx >= len * 8) { | |
287 | u32 i; | |
288 | ||
289 | nidx -= len * 8; | |
290 | i = node->next; | |
291 | hfs_bnode_put(node); | |
292 | if (!i) { | |
293 | /* panic */; | |
7cf3cc30 | 294 | printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this); |
1da177e4 LT |
295 | return; |
296 | } | |
297 | node = hfs_bnode_find(tree, i); | |
298 | if (IS_ERR(node)) | |
299 | return; | |
300 | if (node->type != HFS_NODE_MAP) { | |
301 | /* panic */; | |
7cf3cc30 | 302 | printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type); |
1da177e4 LT |
303 | hfs_bnode_put(node); |
304 | return; | |
305 | } | |
306 | len = hfs_brec_lenoff(node, 0, &off); | |
307 | } | |
308 | off += node->page_offset + nidx / 8; | |
309 | page = node->page[off >> PAGE_CACHE_SHIFT]; | |
310 | data = kmap(page); | |
311 | off &= ~PAGE_CACHE_MASK; | |
312 | m = 1 << (~nidx & 7); | |
313 | byte = data[off]; | |
314 | if (!(byte & m)) { | |
7cf3cc30 | 315 | printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type); |
1da177e4 LT |
316 | kunmap(page); |
317 | hfs_bnode_put(node); | |
318 | return; | |
319 | } | |
320 | data[off] = byte & ~m; | |
321 | set_page_dirty(page); | |
322 | kunmap(page); | |
323 | hfs_bnode_put(node); | |
324 | tree->free_nodes++; | |
325 | mark_inode_dirty(tree->inode); | |
326 | } |