]>
Commit | Line | Data |
---|---|---|
fec577fb CM |
1 | #include <stdio.h> |
2 | #include <stdlib.h> | |
3 | #include "kerncompat.h" | |
4 | #include "radix-tree.h" | |
5 | #include "ctree.h" | |
6 | #include "disk-io.h" | |
7 | #include "print-tree.h" | |
8 | ||
037e6390 CM |
9 | static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks, |
10 | u64 search_start, u64 search_end, struct key *ins); | |
11 | static int finish_current_insert(struct ctree_root *extent_root); | |
12 | static int run_pending(struct ctree_root *extent_root); | |
13 | ||
fec577fb CM |
14 | /* |
15 | * pending extents are blocks that we're trying to allocate in the extent | |
16 | * map while trying to grow the map because of other allocations. To avoid | |
17 | * recursing, they are tagged in the radix tree and cleaned up after | |
18 | * other allocations are done. The pending tag is also used in the same | |
19 | * manner for deletes. | |
20 | */ | |
037e6390 | 21 | #define CTREE_EXTENT_PENDING_DEL 0 |
fec577fb | 22 | |
02217ed2 CM |
23 | static int inc_block_ref(struct ctree_root *root, u64 blocknr) |
24 | { | |
25 | struct ctree_path path; | |
26 | int ret; | |
27 | struct key key; | |
28 | struct leaf *l; | |
29 | struct extent_item *item; | |
037e6390 CM |
30 | struct key ins; |
31 | ||
32 | find_free_extent(root->extent_root, 0, 0, (u64)-1, &ins); | |
02217ed2 CM |
33 | init_path(&path); |
34 | key.objectid = blocknr; | |
35 | key.flags = 0; | |
36 | key.offset = 1; | |
37 | ret = search_slot(root->extent_root, &key, &path, 0, 1); | |
a28ec197 CM |
38 | if (ret != 0) |
39 | BUG(); | |
02217ed2 CM |
40 | BUG_ON(ret != 0); |
41 | l = &path.nodes[0]->leaf; | |
42 | item = (struct extent_item *)(l->data + | |
43 | l->items[path.slots[0]].offset); | |
44 | item->refs++; | |
a28ec197 | 45 | |
02217ed2 CM |
46 | BUG_ON(list_empty(&path.nodes[0]->dirty)); |
47 | release_path(root->extent_root, &path); | |
037e6390 CM |
48 | finish_current_insert(root->extent_root); |
49 | run_pending(root->extent_root); | |
02217ed2 CM |
50 | return 0; |
51 | } | |
52 | ||
20524f02 | 53 | static int lookup_block_ref(struct ctree_root *root, u64 blocknr, u32 *refs) |
a28ec197 CM |
54 | { |
55 | struct ctree_path path; | |
56 | int ret; | |
57 | struct key key; | |
58 | struct leaf *l; | |
59 | struct extent_item *item; | |
60 | init_path(&path); | |
61 | key.objectid = blocknr; | |
62 | key.flags = 0; | |
63 | key.offset = 1; | |
64 | ret = search_slot(root->extent_root, &key, &path, 0, 0); | |
65 | if (ret != 0) | |
66 | BUG(); | |
67 | l = &path.nodes[0]->leaf; | |
68 | item = (struct extent_item *)(l->data + | |
69 | l->items[path.slots[0]].offset); | |
70 | *refs = item->refs; | |
71 | release_path(root->extent_root, &path); | |
72 | return 0; | |
73 | } | |
74 | ||
02217ed2 CM |
75 | int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf) |
76 | { | |
77 | u64 blocknr; | |
78 | int i; | |
a28ec197 CM |
79 | |
80 | if (root == root->extent_root) | |
81 | return 0; | |
82 | if (is_leaf(buf->node.header.flags)) | |
83 | return 0; | |
84 | ||
02217ed2 CM |
85 | for (i = 0; i < buf->node.header.nritems; i++) { |
86 | blocknr = buf->node.blockptrs[i]; | |
87 | inc_block_ref(root, blocknr); | |
88 | } | |
89 | return 0; | |
90 | } | |
91 | ||
a28ec197 CM |
92 | int btrfs_finish_extent_commit(struct ctree_root *root) |
93 | { | |
94 | struct ctree_root *extent_root = root->extent_root; | |
95 | unsigned long gang[8]; | |
96 | int ret; | |
97 | int i; | |
98 | ||
99 | while(1) { | |
100 | ret = radix_tree_gang_lookup(&extent_root->pinned_radix, | |
101 | (void **)gang, 0, | |
102 | ARRAY_SIZE(gang)); | |
103 | if (!ret) | |
104 | break; | |
0579da42 | 105 | for (i = 0; i < ret; i++) { |
a28ec197 | 106 | radix_tree_delete(&extent_root->pinned_radix, gang[i]); |
0579da42 | 107 | } |
a28ec197 | 108 | } |
0579da42 CM |
109 | extent_root->last_insert.objectid = 0; |
110 | extent_root->last_insert.offset = 0; | |
a28ec197 CM |
111 | return 0; |
112 | } | |
113 | ||
037e6390 CM |
114 | static int finish_current_insert(struct ctree_root *extent_root) |
115 | { | |
116 | struct key ins; | |
117 | struct extent_item extent_item; | |
118 | int i; | |
119 | int ret; | |
120 | ||
121 | extent_item.refs = 1; | |
122 | extent_item.owner = extent_root->node->node.header.parentid; | |
123 | ins.offset = 1; | |
124 | ins.flags = 0; | |
125 | ||
126 | for (i = 0; i < extent_root->current_insert.flags; i++) { | |
127 | ins.objectid = extent_root->current_insert.objectid + i; | |
128 | ret = insert_item(extent_root, &ins, &extent_item, | |
129 | sizeof(extent_item)); | |
130 | BUG_ON(ret); | |
131 | } | |
132 | extent_root->current_insert.offset = 0; | |
133 | return 0; | |
134 | } | |
135 | ||
fec577fb | 136 | /* |
a28ec197 | 137 | * remove an extent from the root, returns 0 on success |
fec577fb | 138 | */ |
a28ec197 CM |
139 | int __free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) |
140 | { | |
141 | struct ctree_path path; | |
142 | struct key key; | |
143 | struct ctree_root *extent_root = root->extent_root; | |
144 | int ret; | |
145 | struct item *item; | |
146 | struct extent_item *ei; | |
037e6390 CM |
147 | struct key ins; |
148 | ||
a28ec197 CM |
149 | key.objectid = blocknr; |
150 | key.flags = 0; | |
151 | key.offset = num_blocks; | |
152 | ||
037e6390 | 153 | find_free_extent(root, 0, 0, (u64)-1, &ins); |
a28ec197 CM |
154 | init_path(&path); |
155 | ret = search_slot(extent_root, &key, &path, -1, 1); | |
156 | if (ret) { | |
157 | printf("failed to find %Lu\n", key.objectid); | |
158 | print_tree(extent_root, extent_root->node); | |
159 | printf("failed to find %Lu\n", key.objectid); | |
160 | BUG(); | |
161 | } | |
162 | item = path.nodes[0]->leaf.items + path.slots[0]; | |
163 | ei = (struct extent_item *)(path.nodes[0]->leaf.data + item->offset); | |
164 | BUG_ON(ei->refs == 0); | |
165 | ei->refs--; | |
166 | if (ei->refs == 0) { | |
167 | if (root == extent_root) { | |
168 | int err; | |
169 | radix_tree_preload(GFP_KERNEL); | |
170 | err = radix_tree_insert(&extent_root->pinned_radix, | |
171 | blocknr, (void *)blocknr); | |
172 | BUG_ON(err); | |
173 | radix_tree_preload_end(); | |
174 | } | |
175 | ret = del_item(extent_root, &path); | |
0579da42 CM |
176 | if (root != extent_root && |
177 | extent_root->last_insert.objectid < blocknr) | |
178 | extent_root->last_insert.objectid = blocknr; | |
a28ec197 CM |
179 | if (ret) |
180 | BUG(); | |
181 | } | |
182 | release_path(extent_root, &path); | |
037e6390 | 183 | finish_current_insert(extent_root); |
a28ec197 CM |
184 | return ret; |
185 | } | |
186 | ||
a28ec197 CM |
187 | /* |
188 | * find all the blocks marked as pending in the radix tree and remove | |
189 | * them from the extent map | |
190 | */ | |
191 | static int del_pending_extents(struct ctree_root *extent_root) | |
192 | { | |
193 | int ret; | |
194 | struct tree_buffer *gang[4]; | |
195 | int i; | |
196 | ||
197 | while(1) { | |
198 | ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix, | |
199 | (void **)gang, 0, | |
200 | ARRAY_SIZE(gang), | |
201 | CTREE_EXTENT_PENDING_DEL); | |
202 | if (!ret) | |
203 | break; | |
204 | for (i = 0; i < ret; i++) { | |
205 | ret = __free_extent(extent_root, gang[i]->blocknr, 1); | |
fec577fb CM |
206 | radix_tree_tag_clear(&extent_root->cache_radix, |
207 | gang[i]->blocknr, | |
a28ec197 | 208 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
209 | tree_block_release(extent_root, gang[i]); |
210 | } | |
211 | } | |
212 | return 0; | |
213 | } | |
214 | ||
a28ec197 CM |
215 | static int run_pending(struct ctree_root *extent_root) |
216 | { | |
217 | while(radix_tree_tagged(&extent_root->cache_radix, | |
037e6390 | 218 | CTREE_EXTENT_PENDING_DEL)) |
a28ec197 | 219 | del_pending_extents(extent_root); |
a28ec197 CM |
220 | return 0; |
221 | } | |
222 | ||
223 | ||
fec577fb CM |
224 | /* |
225 | * remove an extent from the root, returns 0 on success | |
226 | */ | |
227 | int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) | |
228 | { | |
fec577fb CM |
229 | struct key key; |
230 | struct ctree_root *extent_root = root->extent_root; | |
231 | struct tree_buffer *t; | |
232 | int pending_ret; | |
233 | int ret; | |
a28ec197 | 234 | |
fec577fb | 235 | if (root == extent_root) { |
a28ec197 | 236 | t = find_tree_block(root, blocknr); |
037e6390 | 237 | radix_tree_tag_set(&root->cache_radix, blocknr, |
a28ec197 | 238 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
239 | return 0; |
240 | } | |
a28ec197 CM |
241 | key.objectid = blocknr; |
242 | key.flags = 0; | |
243 | key.offset = num_blocks; | |
244 | ret = __free_extent(root, blocknr, num_blocks); | |
245 | pending_ret = run_pending(root->extent_root); | |
fec577fb CM |
246 | return ret ? ret : pending_ret; |
247 | } | |
248 | ||
249 | /* | |
250 | * walks the btree of allocated extents and find a hole of a given size. | |
251 | * The key ins is changed to record the hole: | |
252 | * ins->objectid == block start | |
253 | * ins->flags = 0 | |
254 | * ins->offset == number of blocks | |
255 | * Any available blocks before search_start are skipped. | |
256 | */ | |
0f70abe2 CM |
257 | static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks, |
258 | u64 search_start, u64 search_end, struct key *ins) | |
fec577fb CM |
259 | { |
260 | struct ctree_path path; | |
261 | struct key *key; | |
262 | int ret; | |
263 | u64 hole_size = 0; | |
264 | int slot = 0; | |
265 | u64 last_block; | |
037e6390 | 266 | u64 test_block; |
fec577fb CM |
267 | int start_found; |
268 | struct leaf *l; | |
269 | struct ctree_root * root = orig_root->extent_root; | |
0579da42 | 270 | int total_needed = num_blocks; |
fec577fb | 271 | |
0579da42 CM |
272 | total_needed += (node_level(root->node->node.header.flags) + 1) * 3; |
273 | if (root->last_insert.objectid > search_start) | |
274 | search_start = root->last_insert.objectid; | |
fec577fb CM |
275 | check_failed: |
276 | init_path(&path); | |
277 | ins->objectid = search_start; | |
278 | ins->offset = 0; | |
279 | ins->flags = 0; | |
280 | start_found = 0; | |
02217ed2 | 281 | ret = search_slot(root, ins, &path, 0, 0); |
0f70abe2 CM |
282 | if (ret < 0) |
283 | goto error; | |
aa5d6bed | 284 | |
0579da42 CM |
285 | if (path.slots[0] > 0) |
286 | path.slots[0]--; | |
287 | ||
fec577fb CM |
288 | while (1) { |
289 | l = &path.nodes[0]->leaf; | |
290 | slot = path.slots[0]; | |
291 | if (slot >= l->header.nritems) { | |
292 | ret = next_leaf(root, &path); | |
293 | if (ret == 0) | |
294 | continue; | |
0f70abe2 CM |
295 | if (ret < 0) |
296 | goto error; | |
fec577fb CM |
297 | if (!start_found) { |
298 | ins->objectid = search_start; | |
037e6390 | 299 | ins->offset = (u64)-1; |
fec577fb CM |
300 | start_found = 1; |
301 | goto check_pending; | |
302 | } | |
303 | ins->objectid = last_block > search_start ? | |
304 | last_block : search_start; | |
037e6390 | 305 | ins->offset = (u64)-1; |
fec577fb CM |
306 | goto check_pending; |
307 | } | |
308 | key = &l->items[slot].key; | |
309 | if (key->objectid >= search_start) { | |
310 | if (start_found) { | |
0579da42 CM |
311 | if (last_block < search_start) |
312 | last_block = search_start; | |
fec577fb | 313 | hole_size = key->objectid - last_block; |
037e6390 | 314 | if (hole_size > total_needed) { |
fec577fb | 315 | ins->objectid = last_block; |
037e6390 | 316 | ins->offset = hole_size; |
fec577fb CM |
317 | goto check_pending; |
318 | } | |
0579da42 | 319 | } |
fec577fb | 320 | } |
0579da42 CM |
321 | start_found = 1; |
322 | last_block = key->objectid + key->offset; | |
fec577fb CM |
323 | path.slots[0]++; |
324 | } | |
325 | // FIXME -ENOSPC | |
326 | check_pending: | |
327 | /* we have to make sure we didn't find an extent that has already | |
328 | * been allocated by the map tree or the original allocation | |
329 | */ | |
330 | release_path(root, &path); | |
331 | BUG_ON(ins->objectid < search_start); | |
037e6390 CM |
332 | for (test_block = ins->objectid; |
333 | test_block < ins->objectid + total_needed; test_block++) { | |
334 | if (radix_tree_lookup(&root->pinned_radix, test_block)) { | |
335 | search_start = test_block + 1; | |
fec577fb CM |
336 | goto check_failed; |
337 | } | |
338 | } | |
037e6390 | 339 | BUG_ON(root->current_insert.offset); |
0579da42 | 340 | root->current_insert.offset = total_needed - num_blocks; |
037e6390 CM |
341 | root->current_insert.objectid = ins->objectid + num_blocks; |
342 | root->current_insert.flags = 0; | |
0579da42 | 343 | root->last_insert.objectid = ins->objectid; |
037e6390 | 344 | ins->offset = num_blocks; |
fec577fb | 345 | return 0; |
0f70abe2 CM |
346 | error: |
347 | release_path(root, &path); | |
348 | return ret; | |
fec577fb CM |
349 | } |
350 | ||
fec577fb CM |
351 | /* |
352 | * finds a free extent and does all the dirty work required for allocation | |
353 | * returns the key for the extent through ins, and a tree buffer for | |
354 | * the first block of the extent through buf. | |
355 | * | |
356 | * returns 0 if everything worked, non-zero otherwise. | |
357 | */ | |
358 | int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start, | |
037e6390 | 359 | u64 search_end, u64 owner, struct key *ins) |
fec577fb CM |
360 | { |
361 | int ret; | |
362 | int pending_ret; | |
037e6390 | 363 | struct ctree_root *extent_root = root->extent_root; |
fec577fb | 364 | struct extent_item extent_item; |
037e6390 | 365 | |
fec577fb CM |
366 | extent_item.refs = 1; |
367 | extent_item.owner = owner; | |
368 | ||
037e6390 CM |
369 | if (root == extent_root) { |
370 | BUG_ON(extent_root->current_insert.offset == 0); | |
371 | BUG_ON(num_blocks != 1); | |
372 | BUG_ON(extent_root->current_insert.flags == | |
373 | extent_root->current_insert.offset); | |
374 | ins->offset = 1; | |
375 | ins->objectid = extent_root->current_insert.objectid + | |
376 | extent_root->current_insert.flags++; | |
fec577fb CM |
377 | return 0; |
378 | } | |
037e6390 CM |
379 | ret = find_free_extent(root, num_blocks, search_start, |
380 | search_end, ins); | |
381 | if (ret) | |
382 | return ret; | |
fec577fb | 383 | |
037e6390 CM |
384 | ret = insert_item(extent_root, ins, &extent_item, |
385 | sizeof(extent_item)); | |
386 | ||
387 | finish_current_insert(extent_root); | |
388 | pending_ret = run_pending(extent_root); | |
389 | if (ret) | |
390 | return ret; | |
391 | if (pending_ret) | |
392 | return pending_ret; | |
393 | return 0; | |
fec577fb CM |
394 | } |
395 | ||
396 | /* | |
397 | * helper function to allocate a block for a given tree | |
398 | * returns the tree buffer or NULL. | |
399 | */ | |
400 | struct tree_buffer *alloc_free_block(struct ctree_root *root) | |
401 | { | |
402 | struct key ins; | |
403 | int ret; | |
037e6390 | 404 | struct tree_buffer *buf; |
fec577fb CM |
405 | |
406 | ret = alloc_extent(root, 1, 0, (unsigned long)-1, | |
407 | root->node->node.header.parentid, | |
037e6390 | 408 | &ins); |
fec577fb CM |
409 | if (ret) { |
410 | BUG(); | |
411 | return NULL; | |
412 | } | |
037e6390 CM |
413 | buf = find_tree_block(root, ins.objectid); |
414 | dirty_tree_block(root, buf); | |
fec577fb CM |
415 | return buf; |
416 | } | |
a28ec197 | 417 | |
20524f02 CM |
418 | int walk_down_tree(struct ctree_root *root, struct ctree_path *path, int *level) |
419 | { | |
420 | struct tree_buffer *next; | |
421 | struct tree_buffer *cur; | |
422 | u64 blocknr; | |
423 | int ret; | |
424 | u32 refs; | |
425 | ||
426 | ret = lookup_block_ref(root, path->nodes[*level]->blocknr, &refs); | |
427 | BUG_ON(ret); | |
428 | if (refs > 1) | |
429 | goto out; | |
430 | while(*level > 0) { | |
431 | cur = path->nodes[*level]; | |
432 | if (path->slots[*level] >= cur->node.header.nritems) | |
433 | break; | |
434 | blocknr = cur->node.blockptrs[path->slots[*level]]; | |
435 | ret = lookup_block_ref(root, blocknr, &refs); | |
436 | if (refs != 1 || *level == 1) { | |
437 | path->slots[*level]++; | |
438 | ret = free_extent(root, blocknr, 1); | |
439 | BUG_ON(ret); | |
440 | continue; | |
441 | } | |
442 | BUG_ON(ret); | |
443 | next = read_tree_block(root, blocknr); | |
444 | if (path->nodes[*level-1]) { | |
445 | tree_block_release(root, path->nodes[*level-1]); | |
446 | } | |
447 | path->nodes[*level-1] = next; | |
448 | *level = node_level(next->node.header.flags); | |
449 | path->slots[*level] = 0; | |
450 | } | |
451 | out: | |
452 | ret = free_extent(root, path->nodes[*level]->blocknr, 1); | |
453 | path->nodes[*level] = NULL; | |
454 | *level += 1; | |
455 | BUG_ON(ret); | |
456 | return 0; | |
457 | } | |
458 | ||
459 | int walk_up_tree(struct ctree_root *root, struct ctree_path *path, int *level) | |
460 | { | |
461 | int i; | |
462 | int slot; | |
463 | int ret; | |
464 | for(i = *level; i < MAX_LEVEL - 1 && path->nodes[i]; i++) { | |
465 | slot = path->slots[i]; | |
466 | if (slot < path->nodes[i]->node.header.nritems - 1) { | |
467 | path->slots[i]++; | |
468 | *level = i; | |
469 | return 0; | |
470 | } else { | |
471 | ret = free_extent(root, | |
472 | path->nodes[*level]->blocknr, 1); | |
473 | *level = i + 1; | |
474 | BUG_ON(ret); | |
475 | } | |
476 | } | |
477 | return 1; | |
478 | } | |
479 | ||
480 | int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap) | |
481 | { | |
482 | int ret; | |
483 | int level; | |
484 | struct ctree_path path; | |
485 | int i; | |
486 | int orig_level; | |
487 | ||
488 | init_path(&path); | |
489 | ||
490 | level = node_level(snap->node.header.flags); | |
491 | orig_level = level; | |
492 | path.nodes[level] = snap; | |
493 | path.slots[level] = 0; | |
494 | while(1) { | |
495 | ret = walk_down_tree(root, &path, &level); | |
496 | if (ret > 0) | |
497 | break; | |
498 | ret = walk_up_tree(root, &path, &level); | |
499 | if (ret > 0) | |
500 | break; | |
501 | } | |
502 | for (i = 0; i < orig_level; i++) { | |
503 | if (path.nodes[i]) | |
504 | tree_block_release(root, path.nodes[i]); | |
505 | } | |
506 | ||
507 | return 0; | |
508 | } | |
509 | ||
510 | ||
511 | #if 0 | |
a28ec197 CM |
512 | int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap) |
513 | { | |
514 | int ret; | |
515 | int level; | |
516 | int refs; | |
517 | u64 blocknr = snap->blocknr; | |
518 | ||
519 | level = node_level(snap->node.header.flags); | |
520 | ret = lookup_block_ref(root, snap->blocknr, &refs); | |
521 | BUG_ON(ret); | |
522 | if (refs == 1 && level != 0) { | |
523 | struct node *n = &snap->node; | |
524 | struct tree_buffer *b; | |
525 | int i; | |
526 | for (i = 0; i < n->header.nritems; i++) { | |
527 | b = read_tree_block(root, n->blockptrs[i]); | |
528 | /* FIXME, don't recurse here */ | |
529 | ret = btrfs_drop_snapshot(root, b); | |
530 | BUG_ON(ret); | |
531 | tree_block_release(root, b); | |
532 | } | |
533 | } | |
534 | ret = free_extent(root, blocknr, 1); | |
535 | BUG_ON(ret); | |
536 | return 0; | |
537 | } | |
20524f02 | 538 | #endif |