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11#include <linux/pagemap.h>
12#include <linux/slab.h>
13#include <linux/log2.h>
14
15#include "btree.h"
16
17
18struct 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
26 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
27 if (!tree)
28 return NULL;
29
30 mutex_init(&tree->tree_lock);
31 spin_lock_init(&tree->hash_lock);
32
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;
40 BUG_ON(!(tree->inode->i_state & I_NEW));
41 {
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 pr_err("invalid btree extent records\n");
52 unlock_new_inode(tree->inode);
53 goto free_inode;
54 }
55
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));
61
62 if (!HFS_I(tree->inode)->first_blocks) {
63 pr_err("invalid btree extent records (0 size)\n");
64 unlock_new_inode(tree->inode);
65 goto free_inode;
66 }
67
68 tree->inode->i_mapping->a_ops = &hfs_btree_aops;
69 break;
70 default:
71 BUG();
72 }
73 }
74 unlock_new_inode(tree->inode);
75
76 mapping = tree->inode->i_mapping;
77 page = read_mapping_page(mapping, 0, NULL);
78 if (IS_ERR(page))
79 goto free_inode;
80
81
82 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
83 tree->root = be32_to_cpu(head->root);
84 tree->leaf_count = be32_to_cpu(head->leaf_count);
85 tree->leaf_head = be32_to_cpu(head->leaf_head);
86 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
87 tree->node_count = be32_to_cpu(head->node_count);
88 tree->free_nodes = be32_to_cpu(head->free_nodes);
89 tree->attributes = be32_to_cpu(head->attributes);
90 tree->node_size = be16_to_cpu(head->node_size);
91 tree->max_key_len = be16_to_cpu(head->max_key_len);
92 tree->depth = be16_to_cpu(head->depth);
93
94 size = tree->node_size;
95 if (!is_power_of_2(size))
96 goto fail_page;
97 if (!tree->node_count)
98 goto fail_page;
99 switch (id) {
100 case HFS_EXT_CNID:
101 if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
102 pr_err("invalid extent max_key_len %d\n",
103 tree->max_key_len);
104 goto fail_page;
105 }
106 break;
107 case HFS_CAT_CNID:
108 if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
109 pr_err("invalid catalog max_key_len %d\n",
110 tree->max_key_len);
111 goto fail_page;
112 }
113 break;
114 default:
115 BUG();
116 }
117
118 tree->node_size_shift = ffs(size) - 1;
119 tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
120
121 kunmap(page);
122 page_cache_release(page);
123 return tree;
124
125fail_page:
126 page_cache_release(page);
127free_inode:
128 tree->inode->i_mapping->a_ops = &hfs_aops;
129 iput(tree->inode);
130free_tree:
131 kfree(tree);
132 return NULL;
133}
134
135
136void hfs_btree_close(struct hfs_btree *tree)
137{
138 struct hfs_bnode *node;
139 int i;
140
141 if (!tree)
142 return;
143
144 for (i = 0; i < NODE_HASH_SIZE; i++) {
145 while ((node = tree->node_hash[i])) {
146 tree->node_hash[i] = node->next_hash;
147 if (atomic_read(&node->refcnt))
148 pr_err("node %d:%d still has %d user(s)!\n",
149 node->tree->cnid, node->this,
150 atomic_read(&node->refcnt));
151 hfs_bnode_free(node);
152 tree->node_hash_cnt--;
153 }
154 }
155 iput(tree->inode);
156 kfree(tree);
157}
158
159void hfs_btree_write(struct hfs_btree *tree)
160{
161 struct hfs_btree_header_rec *head;
162 struct hfs_bnode *node;
163 struct page *page;
164
165 node = hfs_bnode_find(tree, 0);
166 if (IS_ERR(node))
167
168 return;
169
170 page = node->page[0];
171 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
172
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);
181
182 kunmap(page);
183 set_page_dirty(page);
184 hfs_bnode_put(node);
185}
186
187static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
188{
189 struct hfs_btree *tree = prev->tree;
190 struct hfs_bnode *node;
191 struct hfs_bnode_desc desc;
192 __be32 cnid;
193
194 node = hfs_bnode_create(tree, idx);
195 if (IS_ERR(node))
196 return node;
197
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);
204
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);
218
219 return node;
220}
221
222struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
223{
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;
232
233 while (!tree->free_nodes) {
234 struct inode *inode = tree->inode;
235 u32 count;
236 int res;
237
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;
250 }
251
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;
258
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;
264
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);
279 }
280 }
281 }
282 if (++off >= PAGE_CACHE_SIZE) {
283 kunmap(*pagep);
284 data = kmap(*++pagep);
285 off = 0;
286 }
287 idx += 8;
288 len--;
289 }
290 kunmap(*pagep);
291 nidx = node->next;
292 if (!nidx) {
293 printk(KERN_DEBUG "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;
301
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;
308 }
309}
310
311void hfs_bmap_free(struct hfs_bnode *node)
312{
313 struct hfs_btree *tree;
314 struct page *page;
315 u16 off, len;
316 u32 nidx;
317 u8 *data, byte, m;
318
319 hfs_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;
328
329 nidx -= len * 8;
330 i = node->next;
331 hfs_bnode_put(node);
332 if (!i) {
333 ;
334 pr_crit("unable to free bnode %u. bmap not found!\n",
335 node->this);
336 return;
337 }
338 node = hfs_bnode_find(tree, i);
339 if (IS_ERR(node))
340 return;
341 if (node->type != HFS_NODE_MAP) {
342 ;
343 pr_crit("invalid bmap found! (%u,%d)\n",
344 node->this, node->type);
345 hfs_bnode_put(node);
346 return;
347 }
348 len = hfs_brec_lenoff(node, 0, &off);
349 }
350 off += node->page_offset + nidx / 8;
351 page = node->page[off >> PAGE_CACHE_SHIFT];
352 data = kmap(page);
353 off &= ~PAGE_CACHE_MASK;
354 m = 1 << (~nidx & 7);
355 byte = data[off];
356 if (!(byte & m)) {
357 pr_crit("trying to free free bnode %u(%d)\n",
358 node->this, node->type);
359 kunmap(page);
360 hfs_bnode_put(node);
361 return;
362 }
363 data[off] = byte & ~m;
364 set_page_dirty(page);
365 kunmap(page);
366 hfs_bnode_put(node);
367 tree->free_nodes++;
368 mark_inode_dirty(tree->inode);
369}
370
