1
2
3
4
5
6
7
8
9
10
11#include <linux/pagemap.h>
12#include <linux/swap.h>
13
14#include "btree.h"
15
16void hfs_bnode_read(struct hfs_bnode *node, void *buf,
17 int off, int len)
18{
19 struct page *page;
20
21 off += node->page_offset;
22 page = node->page[0];
23
24 memcpy(buf, kmap(page) + off, len);
25 kunmap(page);
26}
27
28u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
29{
30 __be16 data;
31
32 hfs_bnode_read(node, &data, off, 2);
33 return be16_to_cpu(data);
34}
35
36u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
37{
38 u8 data;
39
40 hfs_bnode_read(node, &data, off, 1);
41 return data;
42}
43
44void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
45{
46 struct hfs_btree *tree;
47 int key_len;
48
49 tree = node->tree;
50 if (node->type == HFS_NODE_LEAF ||
51 tree->attributes & HFS_TREE_VARIDXKEYS)
52 key_len = hfs_bnode_read_u8(node, off) + 1;
53 else
54 key_len = tree->max_key_len + 1;
55
56 hfs_bnode_read(node, key, off, key_len);
57}
58
59void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
60{
61 struct page *page;
62
63 off += node->page_offset;
64 page = node->page[0];
65
66 memcpy(kmap(page) + off, buf, len);
67 kunmap(page);
68 set_page_dirty(page);
69}
70
71void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
72{
73 __be16 v = cpu_to_be16(data);
74
75 hfs_bnode_write(node, &v, off, 2);
76}
77
78void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
79{
80
81 hfs_bnode_write(node, &data, off, 1);
82}
83
84void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
85{
86 struct page *page;
87
88 off += node->page_offset;
89 page = node->page[0];
90
91 memset(kmap(page) + off, 0, len);
92 kunmap(page);
93 set_page_dirty(page);
94}
95
96void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
97 struct hfs_bnode *src_node, int src, int len)
98{
99 struct hfs_btree *tree;
100 struct page *src_page, *dst_page;
101
102 dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
103 if (!len)
104 return;
105 tree = src_node->tree;
106 src += src_node->page_offset;
107 dst += dst_node->page_offset;
108 src_page = src_node->page[0];
109 dst_page = dst_node->page[0];
110
111 memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
112 kunmap(src_page);
113 kunmap(dst_page);
114 set_page_dirty(dst_page);
115}
116
117void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
118{
119 struct page *page;
120 void *ptr;
121
122 dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
123 if (!len)
124 return;
125 src += node->page_offset;
126 dst += node->page_offset;
127 page = node->page[0];
128 ptr = kmap(page);
129 memmove(ptr + dst, ptr + src, len);
130 kunmap(page);
131 set_page_dirty(page);
132}
133
134void hfs_bnode_dump(struct hfs_bnode *node)
135{
136 struct hfs_bnode_desc desc;
137 __be32 cnid;
138 int i, off, key_off;
139
140 dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
141 hfs_bnode_read(node, &desc, 0, sizeof(desc));
142 dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
143 be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
144 desc.type, desc.height, be16_to_cpu(desc.num_recs));
145
146 off = node->tree->node_size - 2;
147 for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
148 key_off = hfs_bnode_read_u16(node, off);
149 dprint(DBG_BNODE_MOD, " %d", key_off);
150 if (i && node->type == HFS_NODE_INDEX) {
151 int tmp;
152
153 if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
154 tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
155 else
156 tmp = node->tree->max_key_len + 1;
157 dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
158 hfs_bnode_read(node, &cnid, key_off + tmp, 4);
159 dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
160 } else if (i && node->type == HFS_NODE_LEAF) {
161 int tmp;
162
163 tmp = hfs_bnode_read_u8(node, key_off);
164 dprint(DBG_BNODE_MOD, " (%d)", tmp);
165 }
166 }
167 dprint(DBG_BNODE_MOD, "\n");
168}
169
170void hfs_bnode_unlink(struct hfs_bnode *node)
171{
172 struct hfs_btree *tree;
173 struct hfs_bnode *tmp;
174 __be32 cnid;
175
176 tree = node->tree;
177 if (node->prev) {
178 tmp = hfs_bnode_find(tree, node->prev);
179 if (IS_ERR(tmp))
180 return;
181 tmp->next = node->next;
182 cnid = cpu_to_be32(tmp->next);
183 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
184 hfs_bnode_put(tmp);
185 } else if (node->type == HFS_NODE_LEAF)
186 tree->leaf_head = node->next;
187
188 if (node->next) {
189 tmp = hfs_bnode_find(tree, node->next);
190 if (IS_ERR(tmp))
191 return;
192 tmp->prev = node->prev;
193 cnid = cpu_to_be32(tmp->prev);
194 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
195 hfs_bnode_put(tmp);
196 } else if (node->type == HFS_NODE_LEAF)
197 tree->leaf_tail = node->prev;
198
199
200 if (!node->prev && !node->next) {
201 printk(KERN_DEBUG "hfs_btree_del_level\n");
202 }
203 if (!node->parent) {
204 tree->root = 0;
205 tree->depth = 0;
206 }
207 set_bit(HFS_BNODE_DELETED, &node->flags);
208}
209
210static inline int hfs_bnode_hash(u32 num)
211{
212 num = (num >> 16) + num;
213 num += num >> 8;
214 return num & (NODE_HASH_SIZE - 1);
215}
216
217struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
218{
219 struct hfs_bnode *node;
220
221 if (cnid >= tree->node_count) {
222 printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
223 return NULL;
224 }
225
226 for (node = tree->node_hash[hfs_bnode_hash(cnid)];
227 node; node = node->next_hash) {
228 if (node->this == cnid) {
229 return node;
230 }
231 }
232 return NULL;
233}
234
235static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
236{
237 struct super_block *sb;
238 struct hfs_bnode *node, *node2;
239 struct address_space *mapping;
240 struct page *page;
241 int size, block, i, hash;
242 loff_t off;
243
244 if (cnid >= tree->node_count) {
245 printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
246 return NULL;
247 }
248
249 sb = tree->inode->i_sb;
250 size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
251 sizeof(struct page *);
252 node = kzalloc(size, GFP_KERNEL);
253 if (!node)
254 return NULL;
255 node->tree = tree;
256 node->this = cnid;
257 set_bit(HFS_BNODE_NEW, &node->flags);
258 atomic_set(&node->refcnt, 1);
259 dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
260 node->tree->cnid, node->this);
261 init_waitqueue_head(&node->lock_wq);
262 spin_lock(&tree->hash_lock);
263 node2 = hfs_bnode_findhash(tree, cnid);
264 if (!node2) {
265 hash = hfs_bnode_hash(cnid);
266 node->next_hash = tree->node_hash[hash];
267 tree->node_hash[hash] = node;
268 tree->node_hash_cnt++;
269 } else {
270 spin_unlock(&tree->hash_lock);
271 kfree(node);
272 wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
273 return node2;
274 }
275 spin_unlock(&tree->hash_lock);
276
277 mapping = tree->inode->i_mapping;
278 off = (loff_t)cnid * tree->node_size;
279 block = off >> PAGE_CACHE_SHIFT;
280 node->page_offset = off & ~PAGE_CACHE_MASK;
281 for (i = 0; i < tree->pages_per_bnode; i++) {
282 page = read_mapping_page(mapping, block++, NULL);
283 if (IS_ERR(page))
284 goto fail;
285 if (PageError(page)) {
286 page_cache_release(page);
287 goto fail;
288 }
289 page_cache_release(page);
290 node->page[i] = page;
291 }
292
293 return node;
294fail:
295 set_bit(HFS_BNODE_ERROR, &node->flags);
296 return node;
297}
298
299void hfs_bnode_unhash(struct hfs_bnode *node)
300{
301 struct hfs_bnode **p;
302
303 dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
304 node->tree->cnid, node->this, atomic_read(&node->refcnt));
305 for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
306 *p && *p != node; p = &(*p)->next_hash)
307 ;
308 BUG_ON(!*p);
309 *p = node->next_hash;
310 node->tree->node_hash_cnt--;
311}
312
313
314struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
315{
316 struct hfs_bnode *node;
317 struct hfs_bnode_desc *desc;
318 int i, rec_off, off, next_off;
319 int entry_size, key_size;
320
321 spin_lock(&tree->hash_lock);
322 node = hfs_bnode_findhash(tree, num);
323 if (node) {
324 hfs_bnode_get(node);
325 spin_unlock(&tree->hash_lock);
326 wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
327 if (test_bit(HFS_BNODE_ERROR, &node->flags))
328 goto node_error;
329 return node;
330 }
331 spin_unlock(&tree->hash_lock);
332 node = __hfs_bnode_create(tree, num);
333 if (!node)
334 return ERR_PTR(-ENOMEM);
335 if (test_bit(HFS_BNODE_ERROR, &node->flags))
336 goto node_error;
337 if (!test_bit(HFS_BNODE_NEW, &node->flags))
338 return node;
339
340 desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
341 node->prev = be32_to_cpu(desc->prev);
342 node->next = be32_to_cpu(desc->next);
343 node->num_recs = be16_to_cpu(desc->num_recs);
344 node->type = desc->type;
345 node->height = desc->height;
346 kunmap(node->page[0]);
347
348 switch (node->type) {
349 case HFS_NODE_HEADER:
350 case HFS_NODE_MAP:
351 if (node->height != 0)
352 goto node_error;
353 break;
354 case HFS_NODE_LEAF:
355 if (node->height != 1)
356 goto node_error;
357 break;
358 case HFS_NODE_INDEX:
359 if (node->height <= 1 || node->height > tree->depth)
360 goto node_error;
361 break;
362 default:
363 goto node_error;
364 }
365
366 rec_off = tree->node_size - 2;
367 off = hfs_bnode_read_u16(node, rec_off);
368 if (off != sizeof(struct hfs_bnode_desc))
369 goto node_error;
370 for (i = 1; i <= node->num_recs; off = next_off, i++) {
371 rec_off -= 2;
372 next_off = hfs_bnode_read_u16(node, rec_off);
373 if (next_off <= off ||
374 next_off > tree->node_size ||
375 next_off & 1)
376 goto node_error;
377 entry_size = next_off - off;
378 if (node->type != HFS_NODE_INDEX &&
379 node->type != HFS_NODE_LEAF)
380 continue;
381 key_size = hfs_bnode_read_u8(node, off) + 1;
382 if (key_size >= entry_size )
383 goto node_error;
384 }
385 clear_bit(HFS_BNODE_NEW, &node->flags);
386 wake_up(&node->lock_wq);
387 return node;
388
389node_error:
390 set_bit(HFS_BNODE_ERROR, &node->flags);
391 clear_bit(HFS_BNODE_NEW, &node->flags);
392 wake_up(&node->lock_wq);
393 hfs_bnode_put(node);
394 return ERR_PTR(-EIO);
395}
396
397void hfs_bnode_free(struct hfs_bnode *node)
398{
399
400
401
402
403
404 kfree(node);
405}
406
407struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
408{
409 struct hfs_bnode *node;
410 struct page **pagep;
411 int i;
412
413 spin_lock(&tree->hash_lock);
414 node = hfs_bnode_findhash(tree, num);
415 spin_unlock(&tree->hash_lock);
416 BUG_ON(node);
417 node = __hfs_bnode_create(tree, num);
418 if (!node)
419 return ERR_PTR(-ENOMEM);
420 if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
421 hfs_bnode_put(node);
422 return ERR_PTR(-EIO);
423 }
424
425 pagep = node->page;
426 memset(kmap(*pagep) + node->page_offset, 0,
427 min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
428 set_page_dirty(*pagep);
429 kunmap(*pagep);
430 for (i = 1; i < tree->pages_per_bnode; i++) {
431 memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
432 set_page_dirty(*pagep);
433 kunmap(*pagep);
434 }
435 clear_bit(HFS_BNODE_NEW, &node->flags);
436 wake_up(&node->lock_wq);
437
438 return node;
439}
440
441void hfs_bnode_get(struct hfs_bnode *node)
442{
443 if (node) {
444 atomic_inc(&node->refcnt);
445 dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
446 node->tree->cnid, node->this, atomic_read(&node->refcnt));
447 }
448}
449
450
451void hfs_bnode_put(struct hfs_bnode *node)
452{
453 if (node) {
454 struct hfs_btree *tree = node->tree;
455 int i;
456
457 dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
458 node->tree->cnid, node->this, atomic_read(&node->refcnt));
459 BUG_ON(!atomic_read(&node->refcnt));
460 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
461 return;
462 for (i = 0; i < tree->pages_per_bnode; i++) {
463 if (!node->page[i])
464 continue;
465 mark_page_accessed(node->page[i]);
466 }
467
468 if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
469 hfs_bnode_unhash(node);
470 spin_unlock(&tree->hash_lock);
471 hfs_bmap_free(node);
472 hfs_bnode_free(node);
473 return;
474 }
475 spin_unlock(&tree->hash_lock);
476 }
477}
478
