diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/hfs/brec.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/hfs/brec.c')
-rw-r--r-- | fs/hfs/brec.c | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/fs/hfs/brec.c b/fs/hfs/brec.c new file mode 100644 index 000000000000..7d8fff2c25fc --- /dev/null +++ b/fs/hfs/brec.c | |||
@@ -0,0 +1,496 @@ | |||
1 | /* | ||
2 | * linux/fs/hfs/brec.c | ||
3 | * | ||
4 | * Copyright (C) 2001 | ||
5 | * Brad Boyer (flar@allandria.com) | ||
6 | * (C) 2003 Ardis Technologies <roman@ardistech.com> | ||
7 | * | ||
8 | * Handle individual btree records | ||
9 | */ | ||
10 | |||
11 | #include "btree.h" | ||
12 | |||
13 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); | ||
14 | static int hfs_brec_update_parent(struct hfs_find_data *fd); | ||
15 | static int hfs_btree_inc_height(struct hfs_btree *tree); | ||
16 | |||
17 | /* Get the length and offset of the given record in the given node */ | ||
18 | u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) | ||
19 | { | ||
20 | __be16 retval[2]; | ||
21 | u16 dataoff; | ||
22 | |||
23 | dataoff = node->tree->node_size - (rec + 2) * 2; | ||
24 | hfs_bnode_read(node, retval, dataoff, 4); | ||
25 | *off = be16_to_cpu(retval[1]); | ||
26 | return be16_to_cpu(retval[0]) - *off; | ||
27 | } | ||
28 | |||
29 | /* Get the length of the key from a keyed record */ | ||
30 | u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) | ||
31 | { | ||
32 | u16 retval, recoff; | ||
33 | |||
34 | if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) | ||
35 | return 0; | ||
36 | |||
37 | if ((node->type == HFS_NODE_INDEX) && | ||
38 | !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) { | ||
39 | if (node->tree->attributes & HFS_TREE_BIGKEYS) | ||
40 | retval = node->tree->max_key_len + 2; | ||
41 | else | ||
42 | retval = node->tree->max_key_len + 1; | ||
43 | } else { | ||
44 | recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2); | ||
45 | if (!recoff) | ||
46 | return 0; | ||
47 | if (node->tree->attributes & HFS_TREE_BIGKEYS) | ||
48 | retval = hfs_bnode_read_u16(node, recoff) + 2; | ||
49 | else | ||
50 | retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1; | ||
51 | } | ||
52 | return retval; | ||
53 | } | ||
54 | |||
55 | int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) | ||
56 | { | ||
57 | struct hfs_btree *tree; | ||
58 | struct hfs_bnode *node, *new_node; | ||
59 | int size, key_len, rec; | ||
60 | int data_off, end_off; | ||
61 | int idx_rec_off, data_rec_off, end_rec_off; | ||
62 | __be32 cnid; | ||
63 | |||
64 | tree = fd->tree; | ||
65 | if (!fd->bnode) { | ||
66 | if (!tree->root) | ||
67 | hfs_btree_inc_height(tree); | ||
68 | fd->bnode = hfs_bnode_find(tree, tree->leaf_head); | ||
69 | if (IS_ERR(fd->bnode)) | ||
70 | return PTR_ERR(fd->bnode); | ||
71 | fd->record = -1; | ||
72 | } | ||
73 | new_node = NULL; | ||
74 | key_len = (fd->search_key->key_len | 1) + 1; | ||
75 | again: | ||
76 | /* new record idx and complete record size */ | ||
77 | rec = fd->record + 1; | ||
78 | size = key_len + entry_len; | ||
79 | |||
80 | node = fd->bnode; | ||
81 | hfs_bnode_dump(node); | ||
82 | /* get last offset */ | ||
83 | end_rec_off = tree->node_size - (node->num_recs + 1) * 2; | ||
84 | end_off = hfs_bnode_read_u16(node, end_rec_off); | ||
85 | end_rec_off -= 2; | ||
86 | dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off); | ||
87 | if (size > end_rec_off - end_off) { | ||
88 | if (new_node) | ||
89 | panic("not enough room!\n"); | ||
90 | new_node = hfs_bnode_split(fd); | ||
91 | if (IS_ERR(new_node)) | ||
92 | return PTR_ERR(new_node); | ||
93 | goto again; | ||
94 | } | ||
95 | if (node->type == HFS_NODE_LEAF) { | ||
96 | tree->leaf_count++; | ||
97 | mark_inode_dirty(tree->inode); | ||
98 | } | ||
99 | node->num_recs++; | ||
100 | /* write new last offset */ | ||
101 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | ||
102 | hfs_bnode_write_u16(node, end_rec_off, end_off + size); | ||
103 | data_off = end_off; | ||
104 | data_rec_off = end_rec_off + 2; | ||
105 | idx_rec_off = tree->node_size - (rec + 1) * 2; | ||
106 | if (idx_rec_off == data_rec_off) | ||
107 | goto skip; | ||
108 | /* move all following entries */ | ||
109 | do { | ||
110 | data_off = hfs_bnode_read_u16(node, data_rec_off + 2); | ||
111 | hfs_bnode_write_u16(node, data_rec_off, data_off + size); | ||
112 | data_rec_off += 2; | ||
113 | } while (data_rec_off < idx_rec_off); | ||
114 | |||
115 | /* move data away */ | ||
116 | hfs_bnode_move(node, data_off + size, data_off, | ||
117 | end_off - data_off); | ||
118 | |||
119 | skip: | ||
120 | hfs_bnode_write(node, fd->search_key, data_off, key_len); | ||
121 | hfs_bnode_write(node, entry, data_off + key_len, entry_len); | ||
122 | hfs_bnode_dump(node); | ||
123 | |||
124 | if (new_node) { | ||
125 | /* update parent key if we inserted a key | ||
126 | * at the start of the first node | ||
127 | */ | ||
128 | if (!rec && new_node != node) | ||
129 | hfs_brec_update_parent(fd); | ||
130 | |||
131 | hfs_bnode_put(fd->bnode); | ||
132 | if (!new_node->parent) { | ||
133 | hfs_btree_inc_height(tree); | ||
134 | new_node->parent = tree->root; | ||
135 | } | ||
136 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | ||
137 | |||
138 | /* create index data entry */ | ||
139 | cnid = cpu_to_be32(new_node->this); | ||
140 | entry = &cnid; | ||
141 | entry_len = sizeof(cnid); | ||
142 | |||
143 | /* get index key */ | ||
144 | hfs_bnode_read_key(new_node, fd->search_key, 14); | ||
145 | __hfs_brec_find(fd->bnode, fd); | ||
146 | |||
147 | hfs_bnode_put(new_node); | ||
148 | new_node = NULL; | ||
149 | |||
150 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | ||
151 | key_len = fd->search_key->key_len + 1; | ||
152 | else { | ||
153 | fd->search_key->key_len = tree->max_key_len; | ||
154 | key_len = tree->max_key_len + 1; | ||
155 | } | ||
156 | goto again; | ||
157 | } | ||
158 | |||
159 | if (!rec) | ||
160 | hfs_brec_update_parent(fd); | ||
161 | |||
162 | return 0; | ||
163 | } | ||
164 | |||
165 | int hfs_brec_remove(struct hfs_find_data *fd) | ||
166 | { | ||
167 | struct hfs_btree *tree; | ||
168 | struct hfs_bnode *node, *parent; | ||
169 | int end_off, rec_off, data_off, size; | ||
170 | |||
171 | tree = fd->tree; | ||
172 | node = fd->bnode; | ||
173 | again: | ||
174 | rec_off = tree->node_size - (fd->record + 2) * 2; | ||
175 | end_off = tree->node_size - (node->num_recs + 1) * 2; | ||
176 | |||
177 | if (node->type == HFS_NODE_LEAF) { | ||
178 | tree->leaf_count--; | ||
179 | mark_inode_dirty(tree->inode); | ||
180 | } | ||
181 | hfs_bnode_dump(node); | ||
182 | dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength); | ||
183 | if (!--node->num_recs) { | ||
184 | hfs_bnode_unlink(node); | ||
185 | if (!node->parent) | ||
186 | return 0; | ||
187 | parent = hfs_bnode_find(tree, node->parent); | ||
188 | if (IS_ERR(parent)) | ||
189 | return PTR_ERR(parent); | ||
190 | hfs_bnode_put(node); | ||
191 | node = fd->bnode = parent; | ||
192 | |||
193 | __hfs_brec_find(node, fd); | ||
194 | goto again; | ||
195 | } | ||
196 | hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); | ||
197 | |||
198 | if (rec_off == end_off) | ||
199 | goto skip; | ||
200 | size = fd->keylength + fd->entrylength; | ||
201 | |||
202 | do { | ||
203 | data_off = hfs_bnode_read_u16(node, rec_off); | ||
204 | hfs_bnode_write_u16(node, rec_off + 2, data_off - size); | ||
205 | rec_off -= 2; | ||
206 | } while (rec_off >= end_off); | ||
207 | |||
208 | /* fill hole */ | ||
209 | hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, | ||
210 | data_off - fd->keyoffset - size); | ||
211 | skip: | ||
212 | hfs_bnode_dump(node); | ||
213 | if (!fd->record) | ||
214 | hfs_brec_update_parent(fd); | ||
215 | return 0; | ||
216 | } | ||
217 | |||
218 | static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) | ||
219 | { | ||
220 | struct hfs_btree *tree; | ||
221 | struct hfs_bnode *node, *new_node; | ||
222 | struct hfs_bnode_desc node_desc; | ||
223 | int num_recs, new_rec_off, new_off, old_rec_off; | ||
224 | int data_start, data_end, size; | ||
225 | |||
226 | tree = fd->tree; | ||
227 | node = fd->bnode; | ||
228 | new_node = hfs_bmap_alloc(tree); | ||
229 | if (IS_ERR(new_node)) | ||
230 | return new_node; | ||
231 | hfs_bnode_get(node); | ||
232 | dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n", | ||
233 | node->this, new_node->this, node->next); | ||
234 | new_node->next = node->next; | ||
235 | new_node->prev = node->this; | ||
236 | new_node->parent = node->parent; | ||
237 | new_node->type = node->type; | ||
238 | new_node->height = node->height; | ||
239 | |||
240 | size = tree->node_size / 2 - node->num_recs * 2 - 14; | ||
241 | old_rec_off = tree->node_size - 4; | ||
242 | num_recs = 1; | ||
243 | for (;;) { | ||
244 | data_start = hfs_bnode_read_u16(node, old_rec_off); | ||
245 | if (data_start > size) | ||
246 | break; | ||
247 | old_rec_off -= 2; | ||
248 | if (++num_recs < node->num_recs) | ||
249 | continue; | ||
250 | /* panic? */ | ||
251 | hfs_bnode_put(node); | ||
252 | hfs_bnode_put(new_node); | ||
253 | return ERR_PTR(-ENOSPC); | ||
254 | } | ||
255 | |||
256 | if (fd->record + 1 < num_recs) { | ||
257 | /* new record is in the lower half, | ||
258 | * so leave some more space there | ||
259 | */ | ||
260 | old_rec_off += 2; | ||
261 | num_recs--; | ||
262 | data_start = hfs_bnode_read_u16(node, old_rec_off); | ||
263 | } else { | ||
264 | hfs_bnode_put(node); | ||
265 | hfs_bnode_get(new_node); | ||
266 | fd->bnode = new_node; | ||
267 | fd->record -= num_recs; | ||
268 | fd->keyoffset -= data_start - 14; | ||
269 | fd->entryoffset -= data_start - 14; | ||
270 | } | ||
271 | new_node->num_recs = node->num_recs - num_recs; | ||
272 | node->num_recs = num_recs; | ||
273 | |||
274 | new_rec_off = tree->node_size - 2; | ||
275 | new_off = 14; | ||
276 | size = data_start - new_off; | ||
277 | num_recs = new_node->num_recs; | ||
278 | data_end = data_start; | ||
279 | while (num_recs) { | ||
280 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | ||
281 | old_rec_off -= 2; | ||
282 | new_rec_off -= 2; | ||
283 | data_end = hfs_bnode_read_u16(node, old_rec_off); | ||
284 | new_off = data_end - size; | ||
285 | num_recs--; | ||
286 | } | ||
287 | hfs_bnode_write_u16(new_node, new_rec_off, new_off); | ||
288 | hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); | ||
289 | |||
290 | /* update new bnode header */ | ||
291 | node_desc.next = cpu_to_be32(new_node->next); | ||
292 | node_desc.prev = cpu_to_be32(new_node->prev); | ||
293 | node_desc.type = new_node->type; | ||
294 | node_desc.height = new_node->height; | ||
295 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | ||
296 | node_desc.reserved = 0; | ||
297 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | ||
298 | |||
299 | /* update previous bnode header */ | ||
300 | node->next = new_node->this; | ||
301 | hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); | ||
302 | node_desc.next = cpu_to_be32(node->next); | ||
303 | node_desc.num_recs = cpu_to_be16(node->num_recs); | ||
304 | hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); | ||
305 | |||
306 | /* update next bnode header */ | ||
307 | if (new_node->next) { | ||
308 | struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next); | ||
309 | next_node->prev = new_node->this; | ||
310 | hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); | ||
311 | node_desc.prev = cpu_to_be32(next_node->prev); | ||
312 | hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); | ||
313 | hfs_bnode_put(next_node); | ||
314 | } else if (node->this == tree->leaf_tail) { | ||
315 | /* if there is no next node, this might be the new tail */ | ||
316 | tree->leaf_tail = new_node->this; | ||
317 | mark_inode_dirty(tree->inode); | ||
318 | } | ||
319 | |||
320 | hfs_bnode_dump(node); | ||
321 | hfs_bnode_dump(new_node); | ||
322 | hfs_bnode_put(node); | ||
323 | |||
324 | return new_node; | ||
325 | } | ||
326 | |||
327 | static int hfs_brec_update_parent(struct hfs_find_data *fd) | ||
328 | { | ||
329 | struct hfs_btree *tree; | ||
330 | struct hfs_bnode *node, *new_node, *parent; | ||
331 | int newkeylen, diff; | ||
332 | int rec, rec_off, end_rec_off; | ||
333 | int start_off, end_off; | ||
334 | |||
335 | tree = fd->tree; | ||
336 | node = fd->bnode; | ||
337 | new_node = NULL; | ||
338 | if (!node->parent) | ||
339 | return 0; | ||
340 | |||
341 | again: | ||
342 | parent = hfs_bnode_find(tree, node->parent); | ||
343 | if (IS_ERR(parent)) | ||
344 | return PTR_ERR(parent); | ||
345 | __hfs_brec_find(parent, fd); | ||
346 | hfs_bnode_dump(parent); | ||
347 | rec = fd->record; | ||
348 | |||
349 | /* size difference between old and new key */ | ||
350 | if (tree->attributes & HFS_TREE_VARIDXKEYS) | ||
351 | newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1; | ||
352 | else | ||
353 | fd->keylength = newkeylen = tree->max_key_len + 1; | ||
354 | dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen); | ||
355 | |||
356 | rec_off = tree->node_size - (rec + 2) * 2; | ||
357 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | ||
358 | diff = newkeylen - fd->keylength; | ||
359 | if (!diff) | ||
360 | goto skip; | ||
361 | if (diff > 0) { | ||
362 | end_off = hfs_bnode_read_u16(parent, end_rec_off); | ||
363 | if (end_rec_off - end_off < diff) { | ||
364 | |||
365 | printk("splitting index node...\n"); | ||
366 | fd->bnode = parent; | ||
367 | new_node = hfs_bnode_split(fd); | ||
368 | if (IS_ERR(new_node)) | ||
369 | return PTR_ERR(new_node); | ||
370 | parent = fd->bnode; | ||
371 | rec = fd->record; | ||
372 | rec_off = tree->node_size - (rec + 2) * 2; | ||
373 | end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; | ||
374 | } | ||
375 | } | ||
376 | |||
377 | end_off = start_off = hfs_bnode_read_u16(parent, rec_off); | ||
378 | hfs_bnode_write_u16(parent, rec_off, start_off + diff); | ||
379 | start_off -= 4; /* move previous cnid too */ | ||
380 | |||
381 | while (rec_off > end_rec_off) { | ||
382 | rec_off -= 2; | ||
383 | end_off = hfs_bnode_read_u16(parent, rec_off); | ||
384 | hfs_bnode_write_u16(parent, rec_off, end_off + diff); | ||
385 | } | ||
386 | hfs_bnode_move(parent, start_off + diff, start_off, | ||
387 | end_off - start_off); | ||
388 | skip: | ||
389 | hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); | ||
390 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) | ||
391 | hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1); | ||
392 | hfs_bnode_dump(parent); | ||
393 | |||
394 | hfs_bnode_put(node); | ||
395 | node = parent; | ||
396 | |||
397 | if (new_node) { | ||
398 | __be32 cnid; | ||
399 | |||
400 | fd->bnode = hfs_bnode_find(tree, new_node->parent); | ||
401 | /* create index key and entry */ | ||
402 | hfs_bnode_read_key(new_node, fd->search_key, 14); | ||
403 | cnid = cpu_to_be32(new_node->this); | ||
404 | |||
405 | __hfs_brec_find(fd->bnode, fd); | ||
406 | hfs_brec_insert(fd, &cnid, sizeof(cnid)); | ||
407 | hfs_bnode_put(fd->bnode); | ||
408 | hfs_bnode_put(new_node); | ||
409 | |||
410 | if (!rec) { | ||
411 | if (new_node == node) | ||
412 | goto out; | ||
413 | /* restore search_key */ | ||
414 | hfs_bnode_read_key(node, fd->search_key, 14); | ||
415 | } | ||
416 | } | ||
417 | |||
418 | if (!rec && node->parent) | ||
419 | goto again; | ||
420 | out: | ||
421 | fd->bnode = node; | ||
422 | return 0; | ||
423 | } | ||
424 | |||
425 | static int hfs_btree_inc_height(struct hfs_btree *tree) | ||
426 | { | ||
427 | struct hfs_bnode *node, *new_node; | ||
428 | struct hfs_bnode_desc node_desc; | ||
429 | int key_size, rec; | ||
430 | __be32 cnid; | ||
431 | |||
432 | node = NULL; | ||
433 | if (tree->root) { | ||
434 | node = hfs_bnode_find(tree, tree->root); | ||
435 | if (IS_ERR(node)) | ||
436 | return PTR_ERR(node); | ||
437 | } | ||
438 | new_node = hfs_bmap_alloc(tree); | ||
439 | if (IS_ERR(new_node)) { | ||
440 | hfs_bnode_put(node); | ||
441 | return PTR_ERR(new_node); | ||
442 | } | ||
443 | |||
444 | tree->root = new_node->this; | ||
445 | if (!tree->depth) { | ||
446 | tree->leaf_head = tree->leaf_tail = new_node->this; | ||
447 | new_node->type = HFS_NODE_LEAF; | ||
448 | new_node->num_recs = 0; | ||
449 | } else { | ||
450 | new_node->type = HFS_NODE_INDEX; | ||
451 | new_node->num_recs = 1; | ||
452 | } | ||
453 | new_node->parent = 0; | ||
454 | new_node->next = 0; | ||
455 | new_node->prev = 0; | ||
456 | new_node->height = ++tree->depth; | ||
457 | |||
458 | node_desc.next = cpu_to_be32(new_node->next); | ||
459 | node_desc.prev = cpu_to_be32(new_node->prev); | ||
460 | node_desc.type = new_node->type; | ||
461 | node_desc.height = new_node->height; | ||
462 | node_desc.num_recs = cpu_to_be16(new_node->num_recs); | ||
463 | node_desc.reserved = 0; | ||
464 | hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); | ||
465 | |||
466 | rec = tree->node_size - 2; | ||
467 | hfs_bnode_write_u16(new_node, rec, 14); | ||
468 | |||
469 | if (node) { | ||
470 | /* insert old root idx into new root */ | ||
471 | node->parent = tree->root; | ||
472 | if (node->type == HFS_NODE_LEAF || | ||
473 | tree->attributes & HFS_TREE_VARIDXKEYS) | ||
474 | key_size = hfs_bnode_read_u8(node, 14) + 1; | ||
475 | else | ||
476 | key_size = tree->max_key_len + 1; | ||
477 | hfs_bnode_copy(new_node, 14, node, 14, key_size); | ||
478 | |||
479 | if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { | ||
480 | key_size = tree->max_key_len + 1; | ||
481 | hfs_bnode_write_u8(new_node, 14, tree->max_key_len); | ||
482 | } | ||
483 | key_size = (key_size + 1) & -2; | ||
484 | cnid = cpu_to_be32(node->this); | ||
485 | hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); | ||
486 | |||
487 | rec -= 2; | ||
488 | hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); | ||
489 | |||
490 | hfs_bnode_put(node); | ||
491 | } | ||
492 | hfs_bnode_put(new_node); | ||
493 | mark_inode_dirty(tree->inode); | ||
494 | |||
495 | return 0; | ||
496 | } | ||