Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
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> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
1da177e4 LT |
14 | #include <linux/swap.h> |
15 | ||
16 | #include "btree.h" | |
17 | ||
1da177e4 LT |
18 | void 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 | ||
30 | u16 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 | ||
38 | u8 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 | ||
46 | void 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 | ||
61 | void 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 | ||
73 | void 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 | ||
80 | void 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 | ||
86 | void 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 | ||
98 | void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst, | |
99 | struct hfs_bnode *src_node, int src, int len) | |
100 | { | |
1da177e4 LT |
101 | struct page *src_page, *dst_page; |
102 | ||
c2b3e1f7 | 103 | hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len); |
1da177e4 LT |
104 | if (!len) |
105 | return; | |
1da177e4 LT |
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 | ||
117 | void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len) | |
118 | { | |
119 | struct page *page; | |
120 | void *ptr; | |
121 | ||
c2b3e1f7 | 122 | hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len); |
1da177e4 LT |
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 | ||
134 | void hfs_bnode_dump(struct hfs_bnode *node) | |
135 | { | |
136 | struct hfs_bnode_desc desc; | |
137 | __be32 cnid; | |
138 | int i, off, key_off; | |
139 | ||
c2b3e1f7 | 140 | hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this); |
1da177e4 | 141 | hfs_bnode_read(node, &desc, 0, sizeof(desc)); |
c2b3e1f7 | 142 | hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n", |
1da177e4 LT |
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); | |
c2b3e1f7 | 149 | hfs_dbg_cont(BNODE_MOD, " %d", key_off); |
1da177e4 LT |
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; | |
c2b3e1f7 JP |
157 | hfs_dbg_cont(BNODE_MOD, " (%d,%d", |
158 | tmp, hfs_bnode_read_u8(node, key_off)); | |
1da177e4 | 159 | hfs_bnode_read(node, &cnid, key_off + tmp, 4); |
c2b3e1f7 | 160 | hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid)); |
1da177e4 LT |
161 | } else if (i && node->type == HFS_NODE_LEAF) { |
162 | int tmp; | |
163 | ||
164 | tmp = hfs_bnode_read_u8(node, key_off); | |
c2b3e1f7 | 165 | hfs_dbg_cont(BNODE_MOD, " (%d)", tmp); |
1da177e4 LT |
166 | } |
167 | } | |
c2b3e1f7 | 168 | hfs_dbg_cont(BNODE_MOD, "\n"); |
1da177e4 LT |
169 | } |
170 | ||
171 | void 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) { | |
7cf3cc30 | 202 | printk(KERN_DEBUG "hfs_btree_del_level\n"); |
1da177e4 LT |
203 | } |
204 | if (!node->parent) { | |
205 | tree->root = 0; | |
206 | tree->depth = 0; | |
207 | } | |
208 | set_bit(HFS_BNODE_DELETED, &node->flags); | |
209 | } | |
210 | ||
211 | static 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 | ||
218 | struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid) | |
219 | { | |
220 | struct hfs_bnode *node; | |
221 | ||
222 | if (cnid >= tree->node_count) { | |
d6142673 | 223 | pr_err("request for non-existent node %d in B*Tree\n", cnid); |
1da177e4 LT |
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 | ||
236 | static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid) | |
237 | { | |
1da177e4 LT |
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) { | |
d6142673 | 245 | pr_err("request for non-existent node %d in B*Tree\n", cnid); |
1da177e4 LT |
246 | return NULL; |
247 | } | |
248 | ||
1da177e4 LT |
249 | size = sizeof(struct hfs_bnode) + tree->pages_per_bnode * |
250 | sizeof(struct page *); | |
f8314dc6 | 251 | node = kzalloc(size, GFP_KERNEL); |
1da177e4 LT |
252 | if (!node) |
253 | return NULL; | |
1da177e4 LT |
254 | node->tree = tree; |
255 | node->this = cnid; | |
256 | set_bit(HFS_BNODE_NEW, &node->flags); | |
257 | atomic_set(&node->refcnt, 1); | |
c2b3e1f7 JP |
258 | hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n", |
259 | node->tree->cnid, node->this); | |
1da177e4 LT |
260 | init_waitqueue_head(&node->lock_wq); |
261 | spin_lock(&tree->hash_lock); | |
262 | node2 = hfs_bnode_findhash(tree, cnid); | |
263 | if (!node2) { | |
264 | hash = hfs_bnode_hash(cnid); | |
265 | node->next_hash = tree->node_hash[hash]; | |
266 | tree->node_hash[hash] = node; | |
267 | tree->node_hash_cnt++; | |
268 | } else { | |
269 | spin_unlock(&tree->hash_lock); | |
270 | kfree(node); | |
271 | wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags)); | |
272 | return node2; | |
273 | } | |
274 | spin_unlock(&tree->hash_lock); | |
275 | ||
276 | mapping = tree->inode->i_mapping; | |
277 | off = (loff_t)cnid * tree->node_size; | |
09cbfeaf KS |
278 | block = off >> PAGE_SHIFT; |
279 | node->page_offset = off & ~PAGE_MASK; | |
1da177e4 | 280 | for (i = 0; i < tree->pages_per_bnode; i++) { |
090d2b18 | 281 | page = read_mapping_page(mapping, block++, NULL); |
1da177e4 LT |
282 | if (IS_ERR(page)) |
283 | goto fail; | |
284 | if (PageError(page)) { | |
09cbfeaf | 285 | put_page(page); |
1da177e4 LT |
286 | goto fail; |
287 | } | |
1da177e4 LT |
288 | node->page[i] = page; |
289 | } | |
290 | ||
291 | return node; | |
292 | fail: | |
293 | set_bit(HFS_BNODE_ERROR, &node->flags); | |
294 | return node; | |
295 | } | |
296 | ||
297 | void hfs_bnode_unhash(struct hfs_bnode *node) | |
298 | { | |
299 | struct hfs_bnode **p; | |
300 | ||
c2b3e1f7 | 301 | hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n", |
1da177e4 LT |
302 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
303 | for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)]; | |
304 | *p && *p != node; p = &(*p)->next_hash) | |
305 | ; | |
4d4ef9ab | 306 | BUG_ON(!*p); |
1da177e4 LT |
307 | *p = node->next_hash; |
308 | node->tree->node_hash_cnt--; | |
309 | } | |
310 | ||
311 | /* Load a particular node out of a tree */ | |
312 | struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num) | |
313 | { | |
314 | struct hfs_bnode *node; | |
315 | struct hfs_bnode_desc *desc; | |
316 | int i, rec_off, off, next_off; | |
317 | int entry_size, key_size; | |
318 | ||
319 | spin_lock(&tree->hash_lock); | |
320 | node = hfs_bnode_findhash(tree, num); | |
321 | if (node) { | |
322 | hfs_bnode_get(node); | |
323 | spin_unlock(&tree->hash_lock); | |
324 | wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags)); | |
325 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) | |
326 | goto node_error; | |
327 | return node; | |
328 | } | |
329 | spin_unlock(&tree->hash_lock); | |
330 | node = __hfs_bnode_create(tree, num); | |
331 | if (!node) | |
332 | return ERR_PTR(-ENOMEM); | |
333 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) | |
334 | goto node_error; | |
335 | if (!test_bit(HFS_BNODE_NEW, &node->flags)) | |
336 | return node; | |
337 | ||
338 | desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset); | |
339 | node->prev = be32_to_cpu(desc->prev); | |
340 | node->next = be32_to_cpu(desc->next); | |
341 | node->num_recs = be16_to_cpu(desc->num_recs); | |
342 | node->type = desc->type; | |
343 | node->height = desc->height; | |
344 | kunmap(node->page[0]); | |
345 | ||
346 | switch (node->type) { | |
347 | case HFS_NODE_HEADER: | |
348 | case HFS_NODE_MAP: | |
349 | if (node->height != 0) | |
350 | goto node_error; | |
351 | break; | |
352 | case HFS_NODE_LEAF: | |
353 | if (node->height != 1) | |
354 | goto node_error; | |
355 | break; | |
356 | case HFS_NODE_INDEX: | |
357 | if (node->height <= 1 || node->height > tree->depth) | |
358 | goto node_error; | |
359 | break; | |
360 | default: | |
361 | goto node_error; | |
362 | } | |
363 | ||
364 | rec_off = tree->node_size - 2; | |
365 | off = hfs_bnode_read_u16(node, rec_off); | |
366 | if (off != sizeof(struct hfs_bnode_desc)) | |
367 | goto node_error; | |
368 | for (i = 1; i <= node->num_recs; off = next_off, i++) { | |
369 | rec_off -= 2; | |
370 | next_off = hfs_bnode_read_u16(node, rec_off); | |
371 | if (next_off <= off || | |
372 | next_off > tree->node_size || | |
373 | next_off & 1) | |
374 | goto node_error; | |
375 | entry_size = next_off - off; | |
376 | if (node->type != HFS_NODE_INDEX && | |
377 | node->type != HFS_NODE_LEAF) | |
378 | continue; | |
379 | key_size = hfs_bnode_read_u8(node, off) + 1; | |
380 | if (key_size >= entry_size /*|| key_size & 1*/) | |
381 | goto node_error; | |
382 | } | |
383 | clear_bit(HFS_BNODE_NEW, &node->flags); | |
384 | wake_up(&node->lock_wq); | |
385 | return node; | |
386 | ||
387 | node_error: | |
388 | set_bit(HFS_BNODE_ERROR, &node->flags); | |
389 | clear_bit(HFS_BNODE_NEW, &node->flags); | |
390 | wake_up(&node->lock_wq); | |
391 | hfs_bnode_put(node); | |
392 | return ERR_PTR(-EIO); | |
393 | } | |
394 | ||
395 | void hfs_bnode_free(struct hfs_bnode *node) | |
396 | { | |
7cb74be6 | 397 | int i; |
1da177e4 | 398 | |
7cb74be6 HTL |
399 | for (i = 0; i < node->tree->pages_per_bnode; i++) |
400 | if (node->page[i]) | |
09cbfeaf | 401 | put_page(node->page[i]); |
1da177e4 LT |
402 | kfree(node); |
403 | } | |
404 | ||
405 | struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num) | |
406 | { | |
407 | struct hfs_bnode *node; | |
408 | struct page **pagep; | |
409 | int i; | |
410 | ||
411 | spin_lock(&tree->hash_lock); | |
412 | node = hfs_bnode_findhash(tree, num); | |
413 | spin_unlock(&tree->hash_lock); | |
fb09c373 JM |
414 | if (node) { |
415 | pr_crit("new node %u already hashed?\n", num); | |
416 | WARN_ON(1); | |
417 | return node; | |
418 | } | |
1da177e4 LT |
419 | node = __hfs_bnode_create(tree, num); |
420 | if (!node) | |
421 | return ERR_PTR(-ENOMEM); | |
422 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) { | |
423 | hfs_bnode_put(node); | |
424 | return ERR_PTR(-EIO); | |
425 | } | |
426 | ||
427 | pagep = node->page; | |
428 | memset(kmap(*pagep) + node->page_offset, 0, | |
09cbfeaf | 429 | min((int)PAGE_SIZE, (int)tree->node_size)); |
1da177e4 LT |
430 | set_page_dirty(*pagep); |
431 | kunmap(*pagep); | |
432 | for (i = 1; i < tree->pages_per_bnode; i++) { | |
09cbfeaf | 433 | memset(kmap(*++pagep), 0, PAGE_SIZE); |
1da177e4 LT |
434 | set_page_dirty(*pagep); |
435 | kunmap(*pagep); | |
436 | } | |
437 | clear_bit(HFS_BNODE_NEW, &node->flags); | |
438 | wake_up(&node->lock_wq); | |
439 | ||
440 | return node; | |
441 | } | |
442 | ||
443 | void hfs_bnode_get(struct hfs_bnode *node) | |
444 | { | |
445 | if (node) { | |
446 | atomic_inc(&node->refcnt); | |
c2b3e1f7 JP |
447 | hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n", |
448 | node->tree->cnid, node->this, | |
449 | atomic_read(&node->refcnt)); | |
1da177e4 LT |
450 | } |
451 | } | |
452 | ||
453 | /* Dispose of resources used by a node */ | |
454 | void hfs_bnode_put(struct hfs_bnode *node) | |
455 | { | |
456 | if (node) { | |
457 | struct hfs_btree *tree = node->tree; | |
458 | int i; | |
459 | ||
c2b3e1f7 JP |
460 | hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n", |
461 | node->tree->cnid, node->this, | |
462 | atomic_read(&node->refcnt)); | |
4d4ef9ab | 463 | BUG_ON(!atomic_read(&node->refcnt)); |
a5e3985f | 464 | if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) |
1da177e4 | 465 | return; |
1da177e4 | 466 | for (i = 0; i < tree->pages_per_bnode; i++) { |
74f9c9c2 RZ |
467 | if (!node->page[i]) |
468 | continue; | |
1da177e4 | 469 | mark_page_accessed(node->page[i]); |
1da177e4 LT |
470 | } |
471 | ||
472 | if (test_bit(HFS_BNODE_DELETED, &node->flags)) { | |
473 | hfs_bnode_unhash(node); | |
474 | spin_unlock(&tree->hash_lock); | |
475 | hfs_bmap_free(node); | |
476 | hfs_bnode_free(node); | |
477 | return; | |
478 | } | |
479 | spin_unlock(&tree->hash_lock); | |
480 | } | |
481 | } |