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11#include <linux/pagemap.h>
12#include <linux/log2.h>
13
14#include "btree.h"
15
16
17struct 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
25 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
26 if (!tree)
27 return NULL;
28
29 init_MUTEX(&tree->tree_lock);
30 spin_lock_init(&tree->hash_lock);
31
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;
39 BUG_ON(!(tree->inode->i_state & I_NEW));
40 {
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();
57 }
58 }
59 unlock_new_inode(tree->inode);
60
61 if (!HFS_I(tree->inode)->first_blocks) {
62 printk(KERN_ERR "hfs: invalid btree extent records (0 size).\n");
63 goto free_inode;
64 }
65
66 mapping = tree->inode->i_mapping;
67 page = read_mapping_page(mapping, 0, NULL);
68 if (IS_ERR(page))
69 goto free_inode;
70
71
72 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
73 tree->root = be32_to_cpu(head->root);
74 tree->leaf_count = be32_to_cpu(head->leaf_count);
75 tree->leaf_head = be32_to_cpu(head->leaf_head);
76 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
77 tree->node_count = be32_to_cpu(head->node_count);
78 tree->free_nodes = be32_to_cpu(head->free_nodes);
79 tree->attributes = be32_to_cpu(head->attributes);
80 tree->node_size = be16_to_cpu(head->node_size);
81 tree->max_key_len = be16_to_cpu(head->max_key_len);
82 tree->depth = be16_to_cpu(head->depth);
83
84 size = tree->node_size;
85 if (!is_power_of_2(size))
86 goto fail_page;
87 if (!tree->node_count)
88 goto fail_page;
89 switch (id) {
90 case HFS_EXT_CNID:
91 if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
92 printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
93 tree->max_key_len);
94 goto fail_page;
95 }
96 break;
97 case HFS_CAT_CNID:
98 if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
99 printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
100 tree->max_key_len);
101 goto fail_page;
102 }
103 break;
104 default:
105 BUG();
106 }
107
108 tree->node_size_shift = ffs(size) - 1;
109 tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
110
111 kunmap(page);
112 page_cache_release(page);
113 return tree;
114
115fail_page:
116 page_cache_release(page);
117free_inode:
118 tree->inode->i_mapping->a_ops = &hfs_aops;
119 iput(tree->inode);
120free_tree:
121 kfree(tree);
122 return NULL;
123}
124
125
126void hfs_btree_close(struct hfs_btree *tree)
127{
128 struct hfs_bnode *node;
129 int i;
130
131 if (!tree)
132 return;
133
134 for (i = 0; i < NODE_HASH_SIZE; i++) {
135 while ((node = tree->node_hash[i])) {
136 tree->node_hash[i] = node->next_hash;
137 if (atomic_read(&node->refcnt))
138 printk(KERN_ERR "hfs: node %d:%d still has %d user(s)!\n",
139 node->tree->cnid, node->this, atomic_read(&node->refcnt));
140 hfs_bnode_free(node);
141 tree->node_hash_cnt--;
142 }
143 }
144 iput(tree->inode);
145 kfree(tree);
146}
147
148void hfs_btree_write(struct hfs_btree *tree)
149{
150 struct hfs_btree_header_rec *head;
151 struct hfs_bnode *node;
152 struct page *page;
153
154 node = hfs_bnode_find(tree, 0);
155 if (IS_ERR(node))
156
157 return;
158
159 page = node->page[0];
160 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
161
162 head->root = cpu_to_be32(tree->root);
163 head->leaf_count = cpu_to_be32(tree->leaf_count);
164 head->leaf_head = cpu_to_be32(tree->leaf_head);
165 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
166 head->node_count = cpu_to_be32(tree->node_count);
167 head->free_nodes = cpu_to_be32(tree->free_nodes);
168 head->attributes = cpu_to_be32(tree->attributes);
169 head->depth = cpu_to_be16(tree->depth);
170
171 kunmap(page);
172 set_page_dirty(page);
173 hfs_bnode_put(node);
174}
175
176static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
177{
178 struct hfs_btree *tree = prev->tree;
179 struct hfs_bnode *node;
180 struct hfs_bnode_desc desc;
181 __be32 cnid;
182
183 node = hfs_bnode_create(tree, idx);
184 if (IS_ERR(node))
185 return node;
186
187 if (!tree->free_nodes)
188 panic("FIXME!!!");
189 tree->free_nodes--;
190 prev->next = idx;
191 cnid = cpu_to_be32(idx);
192 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
193
194 node->type = HFS_NODE_MAP;
195 node->num_recs = 1;
196 hfs_bnode_clear(node, 0, tree->node_size);
197 desc.next = 0;
198 desc.prev = 0;
199 desc.type = HFS_NODE_MAP;
200 desc.height = 0;
201 desc.num_recs = cpu_to_be16(1);
202 desc.reserved = 0;
203 hfs_bnode_write(node, &desc, 0, sizeof(desc));
204 hfs_bnode_write_u16(node, 14, 0x8000);
205 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
206 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
207
208 return node;
209}
210
211struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
212{
213 struct hfs_bnode *node, *next_node;
214 struct page **pagep;
215 u32 nidx, idx;
216 unsigned off;
217 u16 off16;
218 u16 len;
219 u8 *data, byte, m;
220 int i;
221
222 while (!tree->free_nodes) {
223 struct inode *inode = tree->inode;
224 u32 count;
225 int res;
226
227 res = hfs_extend_file(inode);
228 if (res)
229 return ERR_PTR(res);
230 HFS_I(inode)->phys_size = inode->i_size =
231 (loff_t)HFS_I(inode)->alloc_blocks *
232 HFS_SB(tree->sb)->alloc_blksz;
233 HFS_I(inode)->fs_blocks = inode->i_size >>
234 tree->sb->s_blocksize_bits;
235 inode_set_bytes(inode, inode->i_size);
236 count = inode->i_size >> tree->node_size_shift;
237 tree->free_nodes = count - tree->node_count;
238 tree->node_count = count;
239 }
240
241 nidx = 0;
242 node = hfs_bnode_find(tree, nidx);
243 if (IS_ERR(node))
244 return node;
245 len = hfs_brec_lenoff(node, 2, &off16);
246 off = off16;
247
248 off += node->page_offset;
249 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
250 data = kmap(*pagep);
251 off &= ~PAGE_CACHE_MASK;
252 idx = 0;
253
254 for (;;) {
255 while (len) {
256 byte = data[off];
257 if (byte != 0xff) {
258 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
259 if (!(byte & m)) {
260 idx += i;
261 data[off] |= m;
262 set_page_dirty(*pagep);
263 kunmap(*pagep);
264 tree->free_nodes--;
265 mark_inode_dirty(tree->inode);
266 hfs_bnode_put(node);
267 return hfs_bnode_create(tree, idx);
268 }
269 }
270 }
271 if (++off >= PAGE_CACHE_SIZE) {
272 kunmap(*pagep);
273 data = kmap(*++pagep);
274 off = 0;
275 }
276 idx += 8;
277 len--;
278 }
279 kunmap(*pagep);
280 nidx = node->next;
281 if (!nidx) {
282 printk(KERN_DEBUG "hfs: create new bmap node...\n");
283 next_node = hfs_bmap_new_bmap(node, idx);
284 } else
285 next_node = hfs_bnode_find(tree, nidx);
286 hfs_bnode_put(node);
287 if (IS_ERR(next_node))
288 return next_node;
289 node = next_node;
290
291 len = hfs_brec_lenoff(node, 0, &off16);
292 off = off16;
293 off += node->page_offset;
294 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
295 data = kmap(*pagep);
296 off &= ~PAGE_CACHE_MASK;
297 }
298}
299
300void hfs_bmap_free(struct hfs_bnode *node)
301{
302 struct hfs_btree *tree;
303 struct page *page;
304 u16 off, len;
305 u32 nidx;
306 u8 *data, byte, m;
307
308 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
309 tree = node->tree;
310 nidx = node->this;
311 node = hfs_bnode_find(tree, 0);
312 if (IS_ERR(node))
313 return;
314 len = hfs_brec_lenoff(node, 2, &off);
315 while (nidx >= len * 8) {
316 u32 i;
317
318 nidx -= len * 8;
319 i = node->next;
320 hfs_bnode_put(node);
321 if (!i) {
322 ;
323 printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this);
324 return;
325 }
326 node = hfs_bnode_find(tree, i);
327 if (IS_ERR(node))
328 return;
329 if (node->type != HFS_NODE_MAP) {
330 ;
331 printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type);
332 hfs_bnode_put(node);
333 return;
334 }
335 len = hfs_brec_lenoff(node, 0, &off);
336 }
337 off += node->page_offset + nidx / 8;
338 page = node->page[off >> PAGE_CACHE_SHIFT];
339 data = kmap(page);
340 off &= ~PAGE_CACHE_MASK;
341 m = 1 << (~nidx & 7);
342 byte = data[off];
343 if (!(byte & m)) {
344 printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type);
345 kunmap(page);
346 hfs_bnode_put(node);
347 return;
348 }
349 data[off] = byte & ~m;
350 set_page_dirty(page);
351 kunmap(page);
352 hfs_bnode_put(node);
353 tree->free_nodes++;
354 mark_inode_dirty(tree->inode);
355}
356
