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-rw-r--r--fs/hfs/bnode.c498
1 files changed, 498 insertions, 0 deletions
diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c
new file mode 100644
index 000000000000..6ad1211f84ed
--- /dev/null
+++ b/fs/hfs/bnode.c
@@ -0,0 +1,498 @@
1/*
2 * linux/fs/hfs/bnode.c
3 *
4 * Copyright (C) 2001
5 * Brad Boyer (flar@allandria.com)
6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
7 *
8 * Handle basic btree node operations
9 */
10
11#include <linux/pagemap.h>
12#include <linux/swap.h>
13
14#include "btree.h"
15
16#define REF_PAGES 0
17
18void hfs_bnode_read(struct hfs_bnode *node, void *buf,
19 int off, int len)
20{
21 struct page *page;
22
23 off += node->page_offset;
24 page = node->page[0];
25
26 memcpy(buf, kmap(page) + off, len);
27 kunmap(page);
28}
29
30u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
31{
32 __be16 data;
33 // optimize later...
34 hfs_bnode_read(node, &data, off, 2);
35 return be16_to_cpu(data);
36}
37
38u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
39{
40 u8 data;
41 // optimize later...
42 hfs_bnode_read(node, &data, off, 1);
43 return data;
44}
45
46void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
47{
48 struct hfs_btree *tree;
49 int key_len;
50
51 tree = node->tree;
52 if (node->type == HFS_NODE_LEAF ||
53 tree->attributes & HFS_TREE_VARIDXKEYS)
54 key_len = hfs_bnode_read_u8(node, off) + 1;
55 else
56 key_len = tree->max_key_len + 1;
57
58 hfs_bnode_read(node, key, off, key_len);
59}
60
61void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
62{
63 struct page *page;
64
65 off += node->page_offset;
66 page = node->page[0];
67
68 memcpy(kmap(page) + off, buf, len);
69 kunmap(page);
70 set_page_dirty(page);
71}
72
73void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
74{
75 __be16 v = cpu_to_be16(data);
76 // optimize later...
77 hfs_bnode_write(node, &v, off, 2);
78}
79
80void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
81{
82 // optimize later...
83 hfs_bnode_write(node, &data, off, 1);
84}
85
86void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
87{
88 struct page *page;
89
90 off += node->page_offset;
91 page = node->page[0];
92
93 memset(kmap(page) + off, 0, len);
94 kunmap(page);
95 set_page_dirty(page);
96}
97
98void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
99 struct hfs_bnode *src_node, int src, int len)
100{
101 struct hfs_btree *tree;
102 struct page *src_page, *dst_page;
103
104 dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
105 if (!len)
106 return;
107 tree = src_node->tree;
108 src += src_node->page_offset;
109 dst += dst_node->page_offset;
110 src_page = src_node->page[0];
111 dst_page = dst_node->page[0];
112
113 memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
114 kunmap(src_page);
115 kunmap(dst_page);
116 set_page_dirty(dst_page);
117}
118
119void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
120{
121 struct page *page;
122 void *ptr;
123
124 dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
125 if (!len)
126 return;
127 src += node->page_offset;
128 dst += node->page_offset;
129 page = node->page[0];
130 ptr = kmap(page);
131 memmove(ptr + dst, ptr + src, len);
132 kunmap(page);
133 set_page_dirty(page);
134}
135
136void hfs_bnode_dump(struct hfs_bnode *node)
137{
138 struct hfs_bnode_desc desc;
139 __be32 cnid;
140 int i, off, key_off;
141
142 dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
143 hfs_bnode_read(node, &desc, 0, sizeof(desc));
144 dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
145 be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
146 desc.type, desc.height, be16_to_cpu(desc.num_recs));
147
148 off = node->tree->node_size - 2;
149 for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
150 key_off = hfs_bnode_read_u16(node, off);
151 dprint(DBG_BNODE_MOD, " %d", key_off);
152 if (i && node->type == HFS_NODE_INDEX) {
153 int tmp;
154
155 if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
156 tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
157 else
158 tmp = node->tree->max_key_len + 1;
159 dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
160 hfs_bnode_read(node, &cnid, key_off + tmp, 4);
161 dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
162 } else if (i && node->type == HFS_NODE_LEAF) {
163 int tmp;
164
165 tmp = hfs_bnode_read_u8(node, key_off);
166 dprint(DBG_BNODE_MOD, " (%d)", tmp);
167 }
168 }
169 dprint(DBG_BNODE_MOD, "\n");
170}
171
172void hfs_bnode_unlink(struct hfs_bnode *node)
173{
174 struct hfs_btree *tree;
175 struct hfs_bnode *tmp;
176 __be32 cnid;
177
178 tree = node->tree;
179 if (node->prev) {
180 tmp = hfs_bnode_find(tree, node->prev);
181 if (IS_ERR(tmp))
182 return;
183 tmp->next = node->next;
184 cnid = cpu_to_be32(tmp->next);
185 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
186 hfs_bnode_put(tmp);
187 } else if (node->type == HFS_NODE_LEAF)
188 tree->leaf_head = node->next;
189
190 if (node->next) {
191 tmp = hfs_bnode_find(tree, node->next);
192 if (IS_ERR(tmp))
193 return;
194 tmp->prev = node->prev;
195 cnid = cpu_to_be32(tmp->prev);
196 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
197 hfs_bnode_put(tmp);
198 } else if (node->type == HFS_NODE_LEAF)
199 tree->leaf_tail = node->prev;
200
201 // move down?
202 if (!node->prev && !node->next) {
203 printk("hfs_btree_del_level\n");
204 }
205 if (!node->parent) {
206 tree->root = 0;
207 tree->depth = 0;
208 }
209 set_bit(HFS_BNODE_DELETED, &node->flags);
210}
211
212static inline int hfs_bnode_hash(u32 num)
213{
214 num = (num >> 16) + num;
215 num += num >> 8;
216 return num & (NODE_HASH_SIZE - 1);
217}
218
219struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
220{
221 struct hfs_bnode *node;
222
223 if (cnid >= tree->node_count) {
224 printk("HFS: request for non-existent node %d in B*Tree\n", cnid);
225 return NULL;
226 }
227
228 for (node = tree->node_hash[hfs_bnode_hash(cnid)];
229 node; node = node->next_hash) {
230 if (node->this == cnid) {
231 return node;
232 }
233 }
234 return NULL;
235}
236
237static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
238{
239 struct super_block *sb;
240 struct hfs_bnode *node, *node2;
241 struct address_space *mapping;
242 struct page *page;
243 int size, block, i, hash;
244 loff_t off;
245
246 if (cnid >= tree->node_count) {
247 printk("HFS: request for non-existent node %d in B*Tree\n", cnid);
248 return NULL;
249 }
250
251 sb = tree->inode->i_sb;
252 size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
253 sizeof(struct page *);
254 node = kmalloc(size, GFP_KERNEL);
255 if (!node)
256 return NULL;
257 memset(node, 0, size);
258 node->tree = tree;
259 node->this = cnid;
260 set_bit(HFS_BNODE_NEW, &node->flags);
261 atomic_set(&node->refcnt, 1);
262 dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
263 node->tree->cnid, node->this);
264 init_waitqueue_head(&node->lock_wq);
265 spin_lock(&tree->hash_lock);
266 node2 = hfs_bnode_findhash(tree, cnid);
267 if (!node2) {
268 hash = hfs_bnode_hash(cnid);
269 node->next_hash = tree->node_hash[hash];
270 tree->node_hash[hash] = node;
271 tree->node_hash_cnt++;
272 } else {
273 spin_unlock(&tree->hash_lock);
274 kfree(node);
275 wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
276 return node2;
277 }
278 spin_unlock(&tree->hash_lock);
279
280 mapping = tree->inode->i_mapping;
281 off = (loff_t)cnid * tree->node_size;
282 block = off >> PAGE_CACHE_SHIFT;
283 node->page_offset = off & ~PAGE_CACHE_MASK;
284 for (i = 0; i < tree->pages_per_bnode; i++) {
285 page = read_cache_page(mapping, block++, (filler_t *)mapping->a_ops->readpage, NULL);
286 if (IS_ERR(page))
287 goto fail;
288 if (PageError(page)) {
289 page_cache_release(page);
290 goto fail;
291 }
292#if !REF_PAGES
293 page_cache_release(page);
294#endif
295 node->page[i] = page;
296 }
297
298 return node;
299fail:
300 set_bit(HFS_BNODE_ERROR, &node->flags);
301 return node;
302}
303
304void hfs_bnode_unhash(struct hfs_bnode *node)
305{
306 struct hfs_bnode **p;
307
308 dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
309 node->tree->cnid, node->this, atomic_read(&node->refcnt));
310 for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
311 *p && *p != node; p = &(*p)->next_hash)
312 ;
313 if (!*p)
314 BUG();
315 *p = node->next_hash;
316 node->tree->node_hash_cnt--;
317}
318
319/* Load a particular node out of a tree */
320struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
321{
322 struct hfs_bnode *node;
323 struct hfs_bnode_desc *desc;
324 int i, rec_off, off, next_off;
325 int entry_size, key_size;
326
327 spin_lock(&tree->hash_lock);
328 node = hfs_bnode_findhash(tree, num);
329 if (node) {
330 hfs_bnode_get(node);
331 spin_unlock(&tree->hash_lock);
332 wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
333 if (test_bit(HFS_BNODE_ERROR, &node->flags))
334 goto node_error;
335 return node;
336 }
337 spin_unlock(&tree->hash_lock);
338 node = __hfs_bnode_create(tree, num);
339 if (!node)
340 return ERR_PTR(-ENOMEM);
341 if (test_bit(HFS_BNODE_ERROR, &node->flags))
342 goto node_error;
343 if (!test_bit(HFS_BNODE_NEW, &node->flags))
344 return node;
345
346 desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
347 node->prev = be32_to_cpu(desc->prev);
348 node->next = be32_to_cpu(desc->next);
349 node->num_recs = be16_to_cpu(desc->num_recs);
350 node->type = desc->type;
351 node->height = desc->height;
352 kunmap(node->page[0]);
353
354 switch (node->type) {
355 case HFS_NODE_HEADER:
356 case HFS_NODE_MAP:
357 if (node->height != 0)
358 goto node_error;
359 break;
360 case HFS_NODE_LEAF:
361 if (node->height != 1)
362 goto node_error;
363 break;
364 case HFS_NODE_INDEX:
365 if (node->height <= 1 || node->height > tree->depth)
366 goto node_error;
367 break;
368 default:
369 goto node_error;
370 }
371
372 rec_off = tree->node_size - 2;
373 off = hfs_bnode_read_u16(node, rec_off);
374 if (off != sizeof(struct hfs_bnode_desc))
375 goto node_error;
376 for (i = 1; i <= node->num_recs; off = next_off, i++) {
377 rec_off -= 2;
378 next_off = hfs_bnode_read_u16(node, rec_off);
379 if (next_off <= off ||
380 next_off > tree->node_size ||
381 next_off & 1)
382 goto node_error;
383 entry_size = next_off - off;
384 if (node->type != HFS_NODE_INDEX &&
385 node->type != HFS_NODE_LEAF)
386 continue;
387 key_size = hfs_bnode_read_u8(node, off) + 1;
388 if (key_size >= entry_size /*|| key_size & 1*/)
389 goto node_error;
390 }
391 clear_bit(HFS_BNODE_NEW, &node->flags);
392 wake_up(&node->lock_wq);
393 return node;
394
395node_error:
396 set_bit(HFS_BNODE_ERROR, &node->flags);
397 clear_bit(HFS_BNODE_NEW, &node->flags);
398 wake_up(&node->lock_wq);
399 hfs_bnode_put(node);
400 return ERR_PTR(-EIO);
401}
402
403void hfs_bnode_free(struct hfs_bnode *node)
404{
405 //int i;
406
407 //for (i = 0; i < node->tree->pages_per_bnode; i++)
408 // if (node->page[i])
409 // page_cache_release(node->page[i]);
410 kfree(node);
411}
412
413struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
414{
415 struct hfs_bnode *node;
416 struct page **pagep;
417 int i;
418
419 spin_lock(&tree->hash_lock);
420 node = hfs_bnode_findhash(tree, num);
421 spin_unlock(&tree->hash_lock);
422 if (node)
423 BUG();
424 node = __hfs_bnode_create(tree, num);
425 if (!node)
426 return ERR_PTR(-ENOMEM);
427 if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
428 hfs_bnode_put(node);
429 return ERR_PTR(-EIO);
430 }
431
432 pagep = node->page;
433 memset(kmap(*pagep) + node->page_offset, 0,
434 min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
435 set_page_dirty(*pagep);
436 kunmap(*pagep);
437 for (i = 1; i < tree->pages_per_bnode; i++) {
438 memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
439 set_page_dirty(*pagep);
440 kunmap(*pagep);
441 }
442 clear_bit(HFS_BNODE_NEW, &node->flags);
443 wake_up(&node->lock_wq);
444
445 return node;
446}
447
448void hfs_bnode_get(struct hfs_bnode *node)
449{
450 if (node) {
451 atomic_inc(&node->refcnt);
452#if REF_PAGES
453 {
454 int i;
455 for (i = 0; i < node->tree->pages_per_bnode; i++)
456 get_page(node->page[i]);
457 }
458#endif
459 dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
460 node->tree->cnid, node->this, atomic_read(&node->refcnt));
461 }
462}
463
464/* Dispose of resources used by a node */
465void hfs_bnode_put(struct hfs_bnode *node)
466{
467 if (node) {
468 struct hfs_btree *tree = node->tree;
469 int i;
470
471 dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
472 node->tree->cnid, node->this, atomic_read(&node->refcnt));
473 if (!atomic_read(&node->refcnt))
474 BUG();
475 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) {
476#if REF_PAGES
477 for (i = 0; i < tree->pages_per_bnode; i++)
478 put_page(node->page[i]);
479#endif
480 return;
481 }
482 for (i = 0; i < tree->pages_per_bnode; i++) {
483 mark_page_accessed(node->page[i]);
484#if REF_PAGES
485 put_page(node->page[i]);
486#endif
487 }
488
489 if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
490 hfs_bnode_unhash(node);
491 spin_unlock(&tree->hash_lock);
492 hfs_bmap_free(node);
493 hfs_bnode_free(node);
494 return;
495 }
496 spin_unlock(&tree->hash_lock);
497 }
498}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-22 22:39:56 -0500