Commit | Line | Data |
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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; | |
7518a238 | 82 | if (btrfs_is_leaf(&buf->node)) |
a28ec197 CM |
83 | return 0; |
84 | ||
7518a238 | 85 | for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) { |
02217ed2 CM |
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; | |
7518a238 CM |
122 | extent_item.owner = |
123 | btrfs_header_parentid(&extent_root->node->node.header); | |
037e6390 CM |
124 | ins.offset = 1; |
125 | ins.flags = 0; | |
126 | ||
127 | for (i = 0; i < extent_root->current_insert.flags; i++) { | |
128 | ins.objectid = extent_root->current_insert.objectid + i; | |
129 | ret = insert_item(extent_root, &ins, &extent_item, | |
130 | sizeof(extent_item)); | |
131 | BUG_ON(ret); | |
132 | } | |
133 | extent_root->current_insert.offset = 0; | |
134 | return 0; | |
135 | } | |
136 | ||
fec577fb | 137 | /* |
a28ec197 | 138 | * remove an extent from the root, returns 0 on success |
fec577fb | 139 | */ |
a28ec197 CM |
140 | int __free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) |
141 | { | |
142 | struct ctree_path path; | |
143 | struct key key; | |
144 | struct ctree_root *extent_root = root->extent_root; | |
145 | int ret; | |
146 | struct item *item; | |
147 | struct extent_item *ei; | |
037e6390 CM |
148 | struct key ins; |
149 | ||
a28ec197 CM |
150 | key.objectid = blocknr; |
151 | key.flags = 0; | |
152 | key.offset = num_blocks; | |
153 | ||
037e6390 | 154 | find_free_extent(root, 0, 0, (u64)-1, &ins); |
a28ec197 CM |
155 | init_path(&path); |
156 | ret = search_slot(extent_root, &key, &path, -1, 1); | |
157 | if (ret) { | |
158 | printf("failed to find %Lu\n", key.objectid); | |
159 | print_tree(extent_root, extent_root->node); | |
160 | printf("failed to find %Lu\n", key.objectid); | |
161 | BUG(); | |
162 | } | |
163 | item = path.nodes[0]->leaf.items + path.slots[0]; | |
164 | ei = (struct extent_item *)(path.nodes[0]->leaf.data + item->offset); | |
165 | BUG_ON(ei->refs == 0); | |
166 | ei->refs--; | |
167 | if (ei->refs == 0) { | |
168 | if (root == extent_root) { | |
169 | int err; | |
170 | radix_tree_preload(GFP_KERNEL); | |
171 | err = radix_tree_insert(&extent_root->pinned_radix, | |
172 | blocknr, (void *)blocknr); | |
173 | BUG_ON(err); | |
174 | radix_tree_preload_end(); | |
175 | } | |
176 | ret = del_item(extent_root, &path); | |
0579da42 CM |
177 | if (root != extent_root && |
178 | extent_root->last_insert.objectid < blocknr) | |
179 | extent_root->last_insert.objectid = blocknr; | |
a28ec197 CM |
180 | if (ret) |
181 | BUG(); | |
182 | } | |
183 | release_path(extent_root, &path); | |
037e6390 | 184 | finish_current_insert(extent_root); |
a28ec197 CM |
185 | return ret; |
186 | } | |
187 | ||
a28ec197 CM |
188 | /* |
189 | * find all the blocks marked as pending in the radix tree and remove | |
190 | * them from the extent map | |
191 | */ | |
192 | static int del_pending_extents(struct ctree_root *extent_root) | |
193 | { | |
194 | int ret; | |
195 | struct tree_buffer *gang[4]; | |
196 | int i; | |
197 | ||
198 | while(1) { | |
199 | ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix, | |
200 | (void **)gang, 0, | |
201 | ARRAY_SIZE(gang), | |
202 | CTREE_EXTENT_PENDING_DEL); | |
203 | if (!ret) | |
204 | break; | |
205 | for (i = 0; i < ret; i++) { | |
206 | ret = __free_extent(extent_root, gang[i]->blocknr, 1); | |
fec577fb CM |
207 | radix_tree_tag_clear(&extent_root->cache_radix, |
208 | gang[i]->blocknr, | |
a28ec197 | 209 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
210 | tree_block_release(extent_root, gang[i]); |
211 | } | |
212 | } | |
213 | return 0; | |
214 | } | |
215 | ||
a28ec197 CM |
216 | static int run_pending(struct ctree_root *extent_root) |
217 | { | |
218 | while(radix_tree_tagged(&extent_root->cache_radix, | |
037e6390 | 219 | CTREE_EXTENT_PENDING_DEL)) |
a28ec197 | 220 | del_pending_extents(extent_root); |
a28ec197 CM |
221 | return 0; |
222 | } | |
223 | ||
224 | ||
fec577fb CM |
225 | /* |
226 | * remove an extent from the root, returns 0 on success | |
227 | */ | |
228 | int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) | |
229 | { | |
fec577fb CM |
230 | struct key key; |
231 | struct ctree_root *extent_root = root->extent_root; | |
232 | struct tree_buffer *t; | |
233 | int pending_ret; | |
234 | int ret; | |
a28ec197 | 235 | |
fec577fb | 236 | if (root == extent_root) { |
a28ec197 | 237 | t = find_tree_block(root, blocknr); |
037e6390 | 238 | radix_tree_tag_set(&root->cache_radix, blocknr, |
a28ec197 | 239 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
240 | return 0; |
241 | } | |
a28ec197 CM |
242 | key.objectid = blocknr; |
243 | key.flags = 0; | |
244 | key.offset = num_blocks; | |
245 | ret = __free_extent(root, blocknr, num_blocks); | |
246 | pending_ret = run_pending(root->extent_root); | |
fec577fb CM |
247 | return ret ? ret : pending_ret; |
248 | } | |
249 | ||
250 | /* | |
251 | * walks the btree of allocated extents and find a hole of a given size. | |
252 | * The key ins is changed to record the hole: | |
253 | * ins->objectid == block start | |
254 | * ins->flags = 0 | |
255 | * ins->offset == number of blocks | |
256 | * Any available blocks before search_start are skipped. | |
257 | */ | |
0f70abe2 CM |
258 | static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks, |
259 | u64 search_start, u64 search_end, struct key *ins) | |
fec577fb CM |
260 | { |
261 | struct ctree_path path; | |
262 | struct key *key; | |
263 | int ret; | |
264 | u64 hole_size = 0; | |
265 | int slot = 0; | |
266 | u64 last_block; | |
037e6390 | 267 | u64 test_block; |
fec577fb CM |
268 | int start_found; |
269 | struct leaf *l; | |
270 | struct ctree_root * root = orig_root->extent_root; | |
0579da42 | 271 | int total_needed = num_blocks; |
fec577fb | 272 | |
7518a238 | 273 | total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3; |
0579da42 CM |
274 | if (root->last_insert.objectid > search_start) |
275 | search_start = root->last_insert.objectid; | |
fec577fb CM |
276 | check_failed: |
277 | init_path(&path); | |
278 | ins->objectid = search_start; | |
279 | ins->offset = 0; | |
280 | ins->flags = 0; | |
281 | start_found = 0; | |
02217ed2 | 282 | ret = search_slot(root, ins, &path, 0, 0); |
0f70abe2 CM |
283 | if (ret < 0) |
284 | goto error; | |
aa5d6bed | 285 | |
0579da42 CM |
286 | if (path.slots[0] > 0) |
287 | path.slots[0]--; | |
288 | ||
fec577fb CM |
289 | while (1) { |
290 | l = &path.nodes[0]->leaf; | |
291 | slot = path.slots[0]; | |
7518a238 | 292 | if (slot >= btrfs_header_nritems(&l->header)) { |
fec577fb CM |
293 | ret = next_leaf(root, &path); |
294 | if (ret == 0) | |
295 | continue; | |
0f70abe2 CM |
296 | if (ret < 0) |
297 | goto error; | |
fec577fb CM |
298 | if (!start_found) { |
299 | ins->objectid = search_start; | |
037e6390 | 300 | ins->offset = (u64)-1; |
fec577fb CM |
301 | start_found = 1; |
302 | goto check_pending; | |
303 | } | |
304 | ins->objectid = last_block > search_start ? | |
305 | last_block : search_start; | |
037e6390 | 306 | ins->offset = (u64)-1; |
fec577fb CM |
307 | goto check_pending; |
308 | } | |
309 | key = &l->items[slot].key; | |
310 | if (key->objectid >= search_start) { | |
311 | if (start_found) { | |
0579da42 CM |
312 | if (last_block < search_start) |
313 | last_block = search_start; | |
fec577fb | 314 | hole_size = key->objectid - last_block; |
037e6390 | 315 | if (hole_size > total_needed) { |
fec577fb | 316 | ins->objectid = last_block; |
037e6390 | 317 | ins->offset = hole_size; |
fec577fb CM |
318 | goto check_pending; |
319 | } | |
0579da42 | 320 | } |
fec577fb | 321 | } |
0579da42 CM |
322 | start_found = 1; |
323 | last_block = key->objectid + key->offset; | |
fec577fb CM |
324 | path.slots[0]++; |
325 | } | |
326 | // FIXME -ENOSPC | |
327 | check_pending: | |
328 | /* we have to make sure we didn't find an extent that has already | |
329 | * been allocated by the map tree or the original allocation | |
330 | */ | |
331 | release_path(root, &path); | |
332 | BUG_ON(ins->objectid < search_start); | |
037e6390 CM |
333 | for (test_block = ins->objectid; |
334 | test_block < ins->objectid + total_needed; test_block++) { | |
335 | if (radix_tree_lookup(&root->pinned_radix, test_block)) { | |
336 | search_start = test_block + 1; | |
fec577fb CM |
337 | goto check_failed; |
338 | } | |
339 | } | |
037e6390 | 340 | BUG_ON(root->current_insert.offset); |
0579da42 | 341 | root->current_insert.offset = total_needed - num_blocks; |
037e6390 CM |
342 | root->current_insert.objectid = ins->objectid + num_blocks; |
343 | root->current_insert.flags = 0; | |
0579da42 | 344 | root->last_insert.objectid = ins->objectid; |
037e6390 | 345 | ins->offset = num_blocks; |
fec577fb | 346 | return 0; |
0f70abe2 CM |
347 | error: |
348 | release_path(root, &path); | |
349 | return ret; | |
fec577fb CM |
350 | } |
351 | ||
fec577fb CM |
352 | /* |
353 | * finds a free extent and does all the dirty work required for allocation | |
354 | * returns the key for the extent through ins, and a tree buffer for | |
355 | * the first block of the extent through buf. | |
356 | * | |
357 | * returns 0 if everything worked, non-zero otherwise. | |
358 | */ | |
359 | int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start, | |
037e6390 | 360 | u64 search_end, u64 owner, struct key *ins) |
fec577fb CM |
361 | { |
362 | int ret; | |
363 | int pending_ret; | |
037e6390 | 364 | struct ctree_root *extent_root = root->extent_root; |
fec577fb | 365 | struct extent_item extent_item; |
037e6390 | 366 | |
fec577fb CM |
367 | extent_item.refs = 1; |
368 | extent_item.owner = owner; | |
369 | ||
037e6390 CM |
370 | if (root == extent_root) { |
371 | BUG_ON(extent_root->current_insert.offset == 0); | |
372 | BUG_ON(num_blocks != 1); | |
373 | BUG_ON(extent_root->current_insert.flags == | |
374 | extent_root->current_insert.offset); | |
375 | ins->offset = 1; | |
376 | ins->objectid = extent_root->current_insert.objectid + | |
377 | extent_root->current_insert.flags++; | |
fec577fb CM |
378 | return 0; |
379 | } | |
037e6390 CM |
380 | ret = find_free_extent(root, num_blocks, search_start, |
381 | search_end, ins); | |
382 | if (ret) | |
383 | return ret; | |
fec577fb | 384 | |
037e6390 CM |
385 | ret = insert_item(extent_root, ins, &extent_item, |
386 | sizeof(extent_item)); | |
387 | ||
388 | finish_current_insert(extent_root); | |
389 | pending_ret = run_pending(extent_root); | |
390 | if (ret) | |
391 | return ret; | |
392 | if (pending_ret) | |
393 | return pending_ret; | |
394 | return 0; | |
fec577fb CM |
395 | } |
396 | ||
397 | /* | |
398 | * helper function to allocate a block for a given tree | |
399 | * returns the tree buffer or NULL. | |
400 | */ | |
401 | struct tree_buffer *alloc_free_block(struct ctree_root *root) | |
402 | { | |
403 | struct key ins; | |
404 | int ret; | |
037e6390 | 405 | struct tree_buffer *buf; |
fec577fb CM |
406 | |
407 | ret = alloc_extent(root, 1, 0, (unsigned long)-1, | |
7518a238 | 408 | btrfs_header_parentid(&root->node->node.header), |
037e6390 | 409 | &ins); |
fec577fb CM |
410 | if (ret) { |
411 | BUG(); | |
412 | return NULL; | |
413 | } | |
037e6390 CM |
414 | buf = find_tree_block(root, ins.objectid); |
415 | dirty_tree_block(root, buf); | |
fec577fb CM |
416 | return buf; |
417 | } | |
a28ec197 | 418 | |
20524f02 CM |
419 | int walk_down_tree(struct ctree_root *root, struct ctree_path *path, int *level) |
420 | { | |
421 | struct tree_buffer *next; | |
422 | struct tree_buffer *cur; | |
423 | u64 blocknr; | |
424 | int ret; | |
425 | u32 refs; | |
426 | ||
427 | ret = lookup_block_ref(root, path->nodes[*level]->blocknr, &refs); | |
428 | BUG_ON(ret); | |
429 | if (refs > 1) | |
430 | goto out; | |
431 | while(*level > 0) { | |
432 | cur = path->nodes[*level]; | |
7518a238 CM |
433 | if (path->slots[*level] >= |
434 | btrfs_header_nritems(&cur->node.header)) | |
20524f02 CM |
435 | break; |
436 | blocknr = cur->node.blockptrs[path->slots[*level]]; | |
437 | ret = lookup_block_ref(root, blocknr, &refs); | |
438 | if (refs != 1 || *level == 1) { | |
439 | path->slots[*level]++; | |
440 | ret = free_extent(root, blocknr, 1); | |
441 | BUG_ON(ret); | |
442 | continue; | |
443 | } | |
444 | BUG_ON(ret); | |
445 | next = read_tree_block(root, blocknr); | |
83e15a28 | 446 | if (path->nodes[*level-1]) |
20524f02 | 447 | tree_block_release(root, path->nodes[*level-1]); |
20524f02 | 448 | path->nodes[*level-1] = next; |
7518a238 | 449 | *level = btrfs_header_level(&next->node.header); |
20524f02 CM |
450 | path->slots[*level] = 0; |
451 | } | |
452 | out: | |
453 | ret = free_extent(root, path->nodes[*level]->blocknr, 1); | |
83e15a28 | 454 | tree_block_release(root, path->nodes[*level]); |
20524f02 CM |
455 | path->nodes[*level] = NULL; |
456 | *level += 1; | |
457 | BUG_ON(ret); | |
458 | return 0; | |
459 | } | |
460 | ||
461 | int walk_up_tree(struct ctree_root *root, struct ctree_path *path, int *level) | |
462 | { | |
463 | int i; | |
464 | int slot; | |
465 | int ret; | |
466 | for(i = *level; i < MAX_LEVEL - 1 && path->nodes[i]; i++) { | |
467 | slot = path->slots[i]; | |
7518a238 CM |
468 | if (slot < |
469 | btrfs_header_nritems(&path->nodes[i]->node.header)- 1) { | |
20524f02 CM |
470 | path->slots[i]++; |
471 | *level = i; | |
472 | return 0; | |
473 | } else { | |
474 | ret = free_extent(root, | |
475 | path->nodes[*level]->blocknr, 1); | |
83e15a28 CM |
476 | tree_block_release(root, path->nodes[*level]); |
477 | path->nodes[*level] = NULL; | |
20524f02 CM |
478 | *level = i + 1; |
479 | BUG_ON(ret); | |
480 | } | |
481 | } | |
482 | return 1; | |
483 | } | |
484 | ||
485 | int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap) | |
486 | { | |
487 | int ret; | |
488 | int level; | |
489 | struct ctree_path path; | |
490 | int i; | |
491 | int orig_level; | |
492 | ||
493 | init_path(&path); | |
494 | ||
7518a238 | 495 | level = btrfs_header_level(&snap->node.header); |
20524f02 CM |
496 | orig_level = level; |
497 | path.nodes[level] = snap; | |
498 | path.slots[level] = 0; | |
499 | while(1) { | |
500 | ret = walk_down_tree(root, &path, &level); | |
501 | if (ret > 0) | |
502 | break; | |
503 | ret = walk_up_tree(root, &path, &level); | |
504 | if (ret > 0) | |
505 | break; | |
506 | } | |
83e15a28 CM |
507 | for (i = 0; i <= orig_level; i++) { |
508 | if (path.nodes[i]) { | |
20524f02 | 509 | tree_block_release(root, path.nodes[i]); |
83e15a28 | 510 | } |
20524f02 CM |
511 | } |
512 | ||
513 | return 0; | |
514 | } |