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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/slab.h>
13#include <linux/swap.h>
14
15#include "btree.h"
16
17void hfs_bnode_read(struct hfs_bnode *node, void *buf,
18 int off, int len)
19{
20 struct page *page;
21
22 off += node->page_offset;
23 page = node->page[0];
24
25 memcpy(buf, kmap(page) + off, len);
26 kunmap(page);
27}
28
29u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
30{
31 __be16 data;
32 // optimize later...
33 hfs_bnode_read(node, &data, off, 2);
34 return be16_to_cpu(data);
35}
36
37u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
38{
39 u8 data;
40 // optimize later...
41 hfs_bnode_read(node, &data, off, 1);
42 return data;
43}
44
45void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
46{
47 struct hfs_btree *tree;
48 int key_len;
49
50 tree = node->tree;
51 if (node->type == HFS_NODE_LEAF ||
52 tree->attributes & HFS_TREE_VARIDXKEYS)
53 key_len = hfs_bnode_read_u8(node, off) + 1;
54 else
55 key_len = tree->max_key_len + 1;
56
57 hfs_bnode_read(node, key, off, key_len);
58}
59
60void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
61{
62 struct page *page;
63
64 off += node->page_offset;
65 page = node->page[0];
66
67 memcpy(kmap(page) + off, buf, len);
68 kunmap(page);
69 set_page_dirty(page);
70}
71
72void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
73{
74 __be16 v = cpu_to_be16(data);
75 // optimize later...
76 hfs_bnode_write(node, &v, off, 2);
77}
78
79void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
80{
81 // optimize later...
82 hfs_bnode_write(node, &data, off, 1);
83}
84
85void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
86{
87 struct page *page;
88
89 off += node->page_offset;
90 page = node->page[0];
91
92 memset(kmap(page) + off, 0, len);
93 kunmap(page);
94 set_page_dirty(page);
95}
96
97void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
98 struct hfs_bnode *src_node, int src, int len)
99{
100 struct hfs_btree *tree;
101 struct page *src_page, *dst_page;
102
103 dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
104 if (!len)
105 return;
106 tree = src_node->tree;
107 src += src_node->page_offset;
108 dst += dst_node->page_offset;
109 src_page = src_node->page[0];
110 dst_page = dst_node->page[0];
111
112 memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
113 kunmap(src_page);
114 kunmap(dst_page);
115 set_page_dirty(dst_page);
116}
117
118void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
119{
120 struct page *page;
121 void *ptr;
122
123 dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
124 if (!len)
125 return;
126 src += node->page_offset;
127 dst += node->page_offset;
128 page = node->page[0];
129 ptr = kmap(page);
130 memmove(ptr + dst, ptr + src, len);
131 kunmap(page);
132 set_page_dirty(page);
133}
134
135void hfs_bnode_dump(struct hfs_bnode *node)
136{
137 struct hfs_bnode_desc desc;
138 __be32 cnid;
139 int i, off, key_off;
140
141 dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
142 hfs_bnode_read(node, &desc, 0, sizeof(desc));
143 dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
144 be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
145 desc.type, desc.height, be16_to_cpu(desc.num_recs));
146
147 off = node->tree->node_size - 2;
148 for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
149 key_off = hfs_bnode_read_u16(node, off);
150 dprint(DBG_BNODE_MOD, " %d", key_off);
151 if (i && node->type == HFS_NODE_INDEX) {
152 int tmp;
153
154 if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
155 tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
156 else
157 tmp = node->tree->max_key_len + 1;
158 dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
159 hfs_bnode_read(node, &cnid, key_off + tmp, 4);
160 dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
161 } else if (i && node->type == HFS_NODE_LEAF) {
162 int tmp;
163
164 tmp = hfs_bnode_read_u8(node, key_off);
165 dprint(DBG_BNODE_MOD, " (%d)", tmp);
166 }
167 }
168 dprint(DBG_BNODE_MOD, "\n");
169}
170
171void hfs_bnode_unlink(struct hfs_bnode *node)
172{
173 struct hfs_btree *tree;
174 struct hfs_bnode *tmp;
175 __be32 cnid;
176
177 tree = node->tree;
178 if (node->prev) {
179 tmp = hfs_bnode_find(tree, node->prev);
180 if (IS_ERR(tmp))
181 return;
182 tmp->next = node->next;
183 cnid = cpu_to_be32(tmp->next);
184 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
185 hfs_bnode_put(tmp);
186 } else if (node->type == HFS_NODE_LEAF)
187 tree->leaf_head = node->next;
188
189 if (node->next) {
190 tmp = hfs_bnode_find(tree, node->next);
191 if (IS_ERR(tmp))
192 return;
193 tmp->prev = node->prev;
194 cnid = cpu_to_be32(tmp->prev);
195 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
196 hfs_bnode_put(tmp);
197 } else if (node->type == HFS_NODE_LEAF)
198 tree->leaf_tail = node->prev;
199
200 // move down?
201 if (!node->prev && !node->next) {
202 printk(KERN_DEBUG "hfs_btree_del_level\n");
203 }
204 if (!node->parent) {
205 tree->root = 0;
206 tree->depth = 0;
207 }
208 set_bit(HFS_BNODE_DELETED, &node->flags);
209}
210
211static inline int hfs_bnode_hash(u32 num)
212{
213 num = (num >> 16) + num;
214 num += num >> 8;
215 return num & (NODE_HASH_SIZE - 1);
216}
217
218struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
219{
220 struct hfs_bnode *node;
221
222 if (cnid >= tree->node_count) {
223 printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
224 return NULL;
225 }
226
227 for (node = tree->node_hash[hfs_bnode_hash(cnid)];
228 node; node = node->next_hash) {
229 if (node->this == cnid) {
230 return node;
231 }
232 }
233 return NULL;
234}
235
236static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
237{
238 struct super_block *sb;
239 struct hfs_bnode *node, *node2;
240 struct address_space *mapping;
241 struct page *page;
242 int size, block, i, hash;
243 loff_t off;
244
245 if (cnid >= tree->node_count) {
246 printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
247 return NULL;
248 }
249
250 sb = tree->inode->i_sb;
251 size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
252 sizeof(struct page *);
253 node = kzalloc(size, GFP_KERNEL);
254 if (!node)
255 return NULL;
256 node->tree = tree;
257 node->this = cnid;
258 set_bit(HFS_BNODE_NEW, &node->flags);
259 atomic_set(&node->refcnt, 1);
260 dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
261 node->tree->cnid, node->this);
262 init_waitqueue_head(&node->lock_wq);
263 spin_lock(&tree->hash_lock);
264 node2 = hfs_bnode_findhash(tree, cnid);
265 if (!node2) {
266 hash = hfs_bnode_hash(cnid);
267 node->next_hash = tree->node_hash[hash];
268 tree->node_hash[hash] = node;
269 tree->node_hash_cnt++;
270 } else {
271 spin_unlock(&tree->hash_lock);
272 kfree(node);
273 wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
274 return node2;
275 }
276 spin_unlock(&tree->hash_lock);
277
278 mapping = tree->inode->i_mapping;
279 off = (loff_t)cnid * tree->node_size;
280 block = off >> PAGE_CACHE_SHIFT;
281 node->page_offset = off & ~PAGE_CACHE_MASK;
282 for (i = 0; i < tree->pages_per_bnode; i++) {
283 page = read_mapping_page(mapping, block++, NULL);
284 if (IS_ERR(page))
285 goto fail;
286 if (PageError(page)) {
287 page_cache_release(page);
288 goto fail;
289 }
290 page_cache_release(page);
291 node->page[i] = page;
292 }
293
294 return node;
295fail:
296 set_bit(HFS_BNODE_ERROR, &node->flags);
297 return node;
298}
299
300void hfs_bnode_unhash(struct hfs_bnode *node)
301{
302 struct hfs_bnode **p;
303
304 dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
305 node->tree->cnid, node->this, atomic_read(&node->refcnt));
306 for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
307 *p && *p != node; p = &(*p)->next_hash)
308 ;
309 BUG_ON(!*p);
310 *p = node->next_hash;
311 node->tree->node_hash_cnt--;
312}
313
314/* Load a particular node out of a tree */
315struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
316{
317 struct hfs_bnode *node;
318 struct hfs_bnode_desc *desc;
319 int i, rec_off, off, next_off;
320 int entry_size, key_size;
321
322 spin_lock(&tree->hash_lock);
323 node = hfs_bnode_findhash(tree, num);
324 if (node) {
325 hfs_bnode_get(node);
326 spin_unlock(&tree->hash_lock);
327 wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
328 if (test_bit(HFS_BNODE_ERROR, &node->flags))
329 goto node_error;
330 return node;
331 }
332 spin_unlock(&tree->hash_lock);
333 node = __hfs_bnode_create(tree, num);
334 if (!node)
335 return ERR_PTR(-ENOMEM);
336 if (test_bit(HFS_BNODE_ERROR, &node->flags))
337 goto node_error;
338 if (!test_bit(HFS_BNODE_NEW, &node->flags))
339 return node;
340
341 desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
342 node->prev = be32_to_cpu(desc->prev);
343 node->next = be32_to_cpu(desc->next);
344 node->num_recs = be16_to_cpu(desc->num_recs);
345 node->type = desc->type;
346 node->height = desc->height;
347 kunmap(node->page[0]);
348
349 switch (node->type) {
350 case HFS_NODE_HEADER:
351 case HFS_NODE_MAP:
352 if (node->height != 0)
353 goto node_error;
354 break;
355 case HFS_NODE_LEAF:
356 if (node->height != 1)
357 goto node_error;
358 break;
359 case HFS_NODE_INDEX:
360 if (node->height <= 1 || node->height > tree->depth)
361 goto node_error;
362 break;
363 default:
364 goto node_error;
365 }
366
367 rec_off = tree->node_size - 2;
368 off = hfs_bnode_read_u16(node, rec_off);
369 if (off != sizeof(struct hfs_bnode_desc))
370 goto node_error;
371 for (i = 1; i <= node->num_recs; off = next_off, i++) {
372 rec_off -= 2;
373 next_off = hfs_bnode_read_u16(node, rec_off);
374 if (next_off <= off ||
375 next_off > tree->node_size ||
376 next_off & 1)
377 goto node_error;
378 entry_size = next_off - off;
379 if (node->type != HFS_NODE_INDEX &&
380 node->type != HFS_NODE_LEAF)
381 continue;
382 key_size = hfs_bnode_read_u8(node, off) + 1;
383 if (key_size >= entry_size /*|| key_size & 1*/)
384 goto node_error;
385 }
386 clear_bit(HFS_BNODE_NEW, &node->flags);
387 wake_up(&node->lock_wq);
388 return node;
389
390node_error:
391 set_bit(HFS_BNODE_ERROR, &node->flags);
392 clear_bit(HFS_BNODE_NEW, &node->flags);
393 wake_up(&node->lock_wq);
394 hfs_bnode_put(node);
395 return ERR_PTR(-EIO);
396}
397
398void hfs_bnode_free(struct hfs_bnode *node)
399{
400 //int i;
401
402 //for (i = 0; i < node->tree->pages_per_bnode; i++)
403 // if (node->page[i])
404 // page_cache_release(node->page[i]);
405 kfree(node);
406}
407
408struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
409{
410 struct hfs_bnode *node;
411 struct page **pagep;
412 int i;
413
414 spin_lock(&tree->hash_lock);
415 node = hfs_bnode_findhash(tree, num);
416 spin_unlock(&tree->hash_lock);
417 BUG_ON(node);
418 node = __hfs_bnode_create(tree, num);
419 if (!node)
420 return ERR_PTR(-ENOMEM);
421 if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
422 hfs_bnode_put(node);
423 return ERR_PTR(-EIO);
424 }
425
426 pagep = node->page;
427 memset(kmap(*pagep) + node->page_offset, 0,
428 min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
429 set_page_dirty(*pagep);
430 kunmap(*pagep);
431 for (i = 1; i < tree->pages_per_bnode; i++) {
432 memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
433 set_page_dirty(*pagep);
434 kunmap(*pagep);
435 }
436 clear_bit(HFS_BNODE_NEW, &node->flags);
437 wake_up(&node->lock_wq);
438
439 return node;
440}
441
442void hfs_bnode_get(struct hfs_bnode *node)
443{
444 if (node) {
445 atomic_inc(&node->refcnt);
446 dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
447 node->tree->cnid, node->this, atomic_read(&node->refcnt));
448 }
449}
450
451/* Dispose of resources used by a node */
452void hfs_bnode_put(struct hfs_bnode *node)
453{
454 if (node) {
455 struct hfs_btree *tree = node->tree;
456 int i;
457
458 dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
459 node->tree->cnid, node->this, atomic_read(&node->refcnt));
460 BUG_ON(!atomic_read(&node->refcnt));
461 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
462 return;
463 for (i = 0; i < tree->pages_per_bnode; i++) {
464 if (!node->page[i])
465 continue;
466 mark_page_accessed(node->page[i]);
467 }
468
469 if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
470 hfs_bnode_unhash(node);
471 spin_unlock(&tree->hash_lock);
472 hfs_bmap_free(node);
473 hfs_bnode_free(node);
474 return;
475 }
476 spin_unlock(&tree->hash_lock);
477 }
478}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/hfs/bnode.c
4 *
5 * Copyright (C) 2001
6 * Brad Boyer (flar@allandria.com)
7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 *
9 * Handle basic btree node operations
10 */
11
12#include <linux/pagemap.h>
13#include <linux/slab.h>
14#include <linux/swap.h>
15
16#include "btree.h"
17
18void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len)
19{
20 struct page *page;
21 int pagenum;
22 int bytes_read;
23 int bytes_to_read;
24 void *vaddr;
25
26 off += node->page_offset;
27 pagenum = off >> PAGE_SHIFT;
28 off &= ~PAGE_MASK; /* compute page offset for the first page */
29
30 for (bytes_read = 0; bytes_read < len; bytes_read += bytes_to_read) {
31 if (pagenum >= node->tree->pages_per_bnode)
32 break;
33 page = node->page[pagenum];
34 bytes_to_read = min_t(int, len - bytes_read, PAGE_SIZE - off);
35
36 vaddr = kmap_atomic(page);
37 memcpy(buf + bytes_read, vaddr + off, bytes_to_read);
38 kunmap_atomic(vaddr);
39
40 pagenum++;
41 off = 0; /* page offset only applies to the first page */
42 }
43}
44
45u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
46{
47 __be16 data;
48 // optimize later...
49 hfs_bnode_read(node, &data, off, 2);
50 return be16_to_cpu(data);
51}
52
53u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
54{
55 u8 data;
56 // optimize later...
57 hfs_bnode_read(node, &data, off, 1);
58 return data;
59}
60
61void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
62{
63 struct hfs_btree *tree;
64 int key_len;
65
66 tree = node->tree;
67 if (node->type == HFS_NODE_LEAF ||
68 tree->attributes & HFS_TREE_VARIDXKEYS)
69 key_len = hfs_bnode_read_u8(node, off) + 1;
70 else
71 key_len = tree->max_key_len + 1;
72
73 hfs_bnode_read(node, key, off, key_len);
74}
75
76void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
77{
78 struct page *page;
79
80 off += node->page_offset;
81 page = node->page[0];
82
83 memcpy(kmap(page) + off, buf, len);
84 kunmap(page);
85 set_page_dirty(page);
86}
87
88void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
89{
90 __be16 v = cpu_to_be16(data);
91 // optimize later...
92 hfs_bnode_write(node, &v, off, 2);
93}
94
95void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
96{
97 // optimize later...
98 hfs_bnode_write(node, &data, off, 1);
99}
100
101void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
102{
103 struct page *page;
104
105 off += node->page_offset;
106 page = node->page[0];
107
108 memset(kmap(page) + off, 0, len);
109 kunmap(page);
110 set_page_dirty(page);
111}
112
113void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
114 struct hfs_bnode *src_node, int src, int len)
115{
116 struct page *src_page, *dst_page;
117
118 hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
119 if (!len)
120 return;
121 src += src_node->page_offset;
122 dst += dst_node->page_offset;
123 src_page = src_node->page[0];
124 dst_page = dst_node->page[0];
125
126 memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
127 kunmap(src_page);
128 kunmap(dst_page);
129 set_page_dirty(dst_page);
130}
131
132void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
133{
134 struct page *page;
135 void *ptr;
136
137 hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
138 if (!len)
139 return;
140 src += node->page_offset;
141 dst += node->page_offset;
142 page = node->page[0];
143 ptr = kmap(page);
144 memmove(ptr + dst, ptr + src, len);
145 kunmap(page);
146 set_page_dirty(page);
147}
148
149void hfs_bnode_dump(struct hfs_bnode *node)
150{
151 struct hfs_bnode_desc desc;
152 __be32 cnid;
153 int i, off, key_off;
154
155 hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this);
156 hfs_bnode_read(node, &desc, 0, sizeof(desc));
157 hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n",
158 be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
159 desc.type, desc.height, be16_to_cpu(desc.num_recs));
160
161 off = node->tree->node_size - 2;
162 for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
163 key_off = hfs_bnode_read_u16(node, off);
164 hfs_dbg_cont(BNODE_MOD, " %d", key_off);
165 if (i && node->type == HFS_NODE_INDEX) {
166 int tmp;
167
168 if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
169 tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
170 else
171 tmp = node->tree->max_key_len + 1;
172 hfs_dbg_cont(BNODE_MOD, " (%d,%d",
173 tmp, hfs_bnode_read_u8(node, key_off));
174 hfs_bnode_read(node, &cnid, key_off + tmp, 4);
175 hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid));
176 } else if (i && node->type == HFS_NODE_LEAF) {
177 int tmp;
178
179 tmp = hfs_bnode_read_u8(node, key_off);
180 hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
181 }
182 }
183 hfs_dbg_cont(BNODE_MOD, "\n");
184}
185
186void hfs_bnode_unlink(struct hfs_bnode *node)
187{
188 struct hfs_btree *tree;
189 struct hfs_bnode *tmp;
190 __be32 cnid;
191
192 tree = node->tree;
193 if (node->prev) {
194 tmp = hfs_bnode_find(tree, node->prev);
195 if (IS_ERR(tmp))
196 return;
197 tmp->next = node->next;
198 cnid = cpu_to_be32(tmp->next);
199 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
200 hfs_bnode_put(tmp);
201 } else if (node->type == HFS_NODE_LEAF)
202 tree->leaf_head = node->next;
203
204 if (node->next) {
205 tmp = hfs_bnode_find(tree, node->next);
206 if (IS_ERR(tmp))
207 return;
208 tmp->prev = node->prev;
209 cnid = cpu_to_be32(tmp->prev);
210 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
211 hfs_bnode_put(tmp);
212 } else if (node->type == HFS_NODE_LEAF)
213 tree->leaf_tail = node->prev;
214
215 // move down?
216 if (!node->prev && !node->next) {
217 printk(KERN_DEBUG "hfs_btree_del_level\n");
218 }
219 if (!node->parent) {
220 tree->root = 0;
221 tree->depth = 0;
222 }
223 set_bit(HFS_BNODE_DELETED, &node->flags);
224}
225
226static inline int hfs_bnode_hash(u32 num)
227{
228 num = (num >> 16) + num;
229 num += num >> 8;
230 return num & (NODE_HASH_SIZE - 1);
231}
232
233struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
234{
235 struct hfs_bnode *node;
236
237 if (cnid >= tree->node_count) {
238 pr_err("request for non-existent node %d in B*Tree\n", cnid);
239 return NULL;
240 }
241
242 for (node = tree->node_hash[hfs_bnode_hash(cnid)];
243 node; node = node->next_hash) {
244 if (node->this == cnid) {
245 return node;
246 }
247 }
248 return NULL;
249}
250
251static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
252{
253 struct hfs_bnode *node, *node2;
254 struct address_space *mapping;
255 struct page *page;
256 int size, block, i, hash;
257 loff_t off;
258
259 if (cnid >= tree->node_count) {
260 pr_err("request for non-existent node %d in B*Tree\n", cnid);
261 return NULL;
262 }
263
264 size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
265 sizeof(struct page *);
266 node = kzalloc(size, GFP_KERNEL);
267 if (!node)
268 return NULL;
269 node->tree = tree;
270 node->this = cnid;
271 set_bit(HFS_BNODE_NEW, &node->flags);
272 atomic_set(&node->refcnt, 1);
273 hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n",
274 node->tree->cnid, node->this);
275 init_waitqueue_head(&node->lock_wq);
276 spin_lock(&tree->hash_lock);
277 node2 = hfs_bnode_findhash(tree, cnid);
278 if (!node2) {
279 hash = hfs_bnode_hash(cnid);
280 node->next_hash = tree->node_hash[hash];
281 tree->node_hash[hash] = node;
282 tree->node_hash_cnt++;
283 } else {
284 spin_unlock(&tree->hash_lock);
285 kfree(node);
286 wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
287 return node2;
288 }
289 spin_unlock(&tree->hash_lock);
290
291 mapping = tree->inode->i_mapping;
292 off = (loff_t)cnid * tree->node_size;
293 block = off >> PAGE_SHIFT;
294 node->page_offset = off & ~PAGE_MASK;
295 for (i = 0; i < tree->pages_per_bnode; i++) {
296 page = read_mapping_page(mapping, block++, NULL);
297 if (IS_ERR(page))
298 goto fail;
299 if (PageError(page)) {
300 put_page(page);
301 goto fail;
302 }
303 node->page[i] = page;
304 }
305
306 return node;
307fail:
308 set_bit(HFS_BNODE_ERROR, &node->flags);
309 return node;
310}
311
312void hfs_bnode_unhash(struct hfs_bnode *node)
313{
314 struct hfs_bnode **p;
315
316 hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n",
317 node->tree->cnid, node->this, atomic_read(&node->refcnt));
318 for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
319 *p && *p != node; p = &(*p)->next_hash)
320 ;
321 BUG_ON(!*p);
322 *p = node->next_hash;
323 node->tree->node_hash_cnt--;
324}
325
326/* Load a particular node out of a tree */
327struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
328{
329 struct hfs_bnode *node;
330 struct hfs_bnode_desc *desc;
331 int i, rec_off, off, next_off;
332 int entry_size, key_size;
333
334 spin_lock(&tree->hash_lock);
335 node = hfs_bnode_findhash(tree, num);
336 if (node) {
337 hfs_bnode_get(node);
338 spin_unlock(&tree->hash_lock);
339 wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
340 if (test_bit(HFS_BNODE_ERROR, &node->flags))
341 goto node_error;
342 return node;
343 }
344 spin_unlock(&tree->hash_lock);
345 node = __hfs_bnode_create(tree, num);
346 if (!node)
347 return ERR_PTR(-ENOMEM);
348 if (test_bit(HFS_BNODE_ERROR, &node->flags))
349 goto node_error;
350 if (!test_bit(HFS_BNODE_NEW, &node->flags))
351 return node;
352
353 desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
354 node->prev = be32_to_cpu(desc->prev);
355 node->next = be32_to_cpu(desc->next);
356 node->num_recs = be16_to_cpu(desc->num_recs);
357 node->type = desc->type;
358 node->height = desc->height;
359 kunmap(node->page[0]);
360
361 switch (node->type) {
362 case HFS_NODE_HEADER:
363 case HFS_NODE_MAP:
364 if (node->height != 0)
365 goto node_error;
366 break;
367 case HFS_NODE_LEAF:
368 if (node->height != 1)
369 goto node_error;
370 break;
371 case HFS_NODE_INDEX:
372 if (node->height <= 1 || node->height > tree->depth)
373 goto node_error;
374 break;
375 default:
376 goto node_error;
377 }
378
379 rec_off = tree->node_size - 2;
380 off = hfs_bnode_read_u16(node, rec_off);
381 if (off != sizeof(struct hfs_bnode_desc))
382 goto node_error;
383 for (i = 1; i <= node->num_recs; off = next_off, i++) {
384 rec_off -= 2;
385 next_off = hfs_bnode_read_u16(node, rec_off);
386 if (next_off <= off ||
387 next_off > tree->node_size ||
388 next_off & 1)
389 goto node_error;
390 entry_size = next_off - off;
391 if (node->type != HFS_NODE_INDEX &&
392 node->type != HFS_NODE_LEAF)
393 continue;
394 key_size = hfs_bnode_read_u8(node, off) + 1;
395 if (key_size >= entry_size /*|| key_size & 1*/)
396 goto node_error;
397 }
398 clear_bit(HFS_BNODE_NEW, &node->flags);
399 wake_up(&node->lock_wq);
400 return node;
401
402node_error:
403 set_bit(HFS_BNODE_ERROR, &node->flags);
404 clear_bit(HFS_BNODE_NEW, &node->flags);
405 wake_up(&node->lock_wq);
406 hfs_bnode_put(node);
407 return ERR_PTR(-EIO);
408}
409
410void hfs_bnode_free(struct hfs_bnode *node)
411{
412 int i;
413
414 for (i = 0; i < node->tree->pages_per_bnode; i++)
415 if (node->page[i])
416 put_page(node->page[i]);
417 kfree(node);
418}
419
420struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
421{
422 struct hfs_bnode *node;
423 struct page **pagep;
424 int i;
425
426 spin_lock(&tree->hash_lock);
427 node = hfs_bnode_findhash(tree, num);
428 spin_unlock(&tree->hash_lock);
429 if (node) {
430 pr_crit("new node %u already hashed?\n", num);
431 WARN_ON(1);
432 return node;
433 }
434 node = __hfs_bnode_create(tree, num);
435 if (!node)
436 return ERR_PTR(-ENOMEM);
437 if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
438 hfs_bnode_put(node);
439 return ERR_PTR(-EIO);
440 }
441
442 pagep = node->page;
443 memset(kmap(*pagep) + node->page_offset, 0,
444 min((int)PAGE_SIZE, (int)tree->node_size));
445 set_page_dirty(*pagep);
446 kunmap(*pagep);
447 for (i = 1; i < tree->pages_per_bnode; i++) {
448 memset(kmap(*++pagep), 0, PAGE_SIZE);
449 set_page_dirty(*pagep);
450 kunmap(*pagep);
451 }
452 clear_bit(HFS_BNODE_NEW, &node->flags);
453 wake_up(&node->lock_wq);
454
455 return node;
456}
457
458void hfs_bnode_get(struct hfs_bnode *node)
459{
460 if (node) {
461 atomic_inc(&node->refcnt);
462 hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n",
463 node->tree->cnid, node->this,
464 atomic_read(&node->refcnt));
465 }
466}
467
468/* Dispose of resources used by a node */
469void hfs_bnode_put(struct hfs_bnode *node)
470{
471 if (node) {
472 struct hfs_btree *tree = node->tree;
473 int i;
474
475 hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n",
476 node->tree->cnid, node->this,
477 atomic_read(&node->refcnt));
478 BUG_ON(!atomic_read(&node->refcnt));
479 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
480 return;
481 for (i = 0; i < tree->pages_per_bnode; i++) {
482 if (!node->page[i])
483 continue;
484 mark_page_accessed(node->page[i]);
485 }
486
487 if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
488 hfs_bnode_unhash(node);
489 spin_unlock(&tree->hash_lock);
490 hfs_bmap_free(node);
491 hfs_bnode_free(node);
492 return;
493 }
494 spin_unlock(&tree->hash_lock);
495 }
496}