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1 | /* | |
2 | * Copyright (C) 2008 Red Hat. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
19 | #include <linux/pagemap.h> | |
20 | #include <linux/sched.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/math64.h> | |
23 | #include "ctree.h" | |
24 | #include "free-space-cache.h" | |
25 | #include "transaction.h" | |
26 | #include "disk-io.h" | |
27 | #include "extent_io.h" | |
28 | #include "inode-map.h" | |
29 | ||
30 | #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) | |
31 | #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) | |
32 | ||
33 | static int link_free_space(struct btrfs_free_space_ctl *ctl, | |
34 | struct btrfs_free_space *info); | |
35 | ||
36 | static struct inode *__lookup_free_space_inode(struct btrfs_root *root, | |
37 | struct btrfs_path *path, | |
38 | u64 offset) | |
39 | { | |
40 | struct btrfs_key key; | |
41 | struct btrfs_key location; | |
42 | struct btrfs_disk_key disk_key; | |
43 | struct btrfs_free_space_header *header; | |
44 | struct extent_buffer *leaf; | |
45 | struct inode *inode = NULL; | |
46 | int ret; | |
47 | ||
48 | key.objectid = BTRFS_FREE_SPACE_OBJECTID; | |
49 | key.offset = offset; | |
50 | key.type = 0; | |
51 | ||
52 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
53 | if (ret < 0) | |
54 | return ERR_PTR(ret); | |
55 | if (ret > 0) { | |
56 | btrfs_release_path(path); | |
57 | return ERR_PTR(-ENOENT); | |
58 | } | |
59 | ||
60 | leaf = path->nodes[0]; | |
61 | header = btrfs_item_ptr(leaf, path->slots[0], | |
62 | struct btrfs_free_space_header); | |
63 | btrfs_free_space_key(leaf, header, &disk_key); | |
64 | btrfs_disk_key_to_cpu(&location, &disk_key); | |
65 | btrfs_release_path(path); | |
66 | ||
67 | inode = btrfs_iget(root->fs_info->sb, &location, root, NULL); | |
68 | if (!inode) | |
69 | return ERR_PTR(-ENOENT); | |
70 | if (IS_ERR(inode)) | |
71 | return inode; | |
72 | if (is_bad_inode(inode)) { | |
73 | iput(inode); | |
74 | return ERR_PTR(-ENOENT); | |
75 | } | |
76 | ||
77 | inode->i_mapping->flags &= ~__GFP_FS; | |
78 | ||
79 | return inode; | |
80 | } | |
81 | ||
82 | struct inode *lookup_free_space_inode(struct btrfs_root *root, | |
83 | struct btrfs_block_group_cache | |
84 | *block_group, struct btrfs_path *path) | |
85 | { | |
86 | struct inode *inode = NULL; | |
87 | ||
88 | spin_lock(&block_group->lock); | |
89 | if (block_group->inode) | |
90 | inode = igrab(block_group->inode); | |
91 | spin_unlock(&block_group->lock); | |
92 | if (inode) | |
93 | return inode; | |
94 | ||
95 | inode = __lookup_free_space_inode(root, path, | |
96 | block_group->key.objectid); | |
97 | if (IS_ERR(inode)) | |
98 | return inode; | |
99 | ||
100 | spin_lock(&block_group->lock); | |
101 | if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) { | |
102 | printk(KERN_INFO "Old style space inode found, converting.\n"); | |
103 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_NODATASUM; | |
104 | block_group->disk_cache_state = BTRFS_DC_CLEAR; | |
105 | } | |
106 | ||
107 | if (!btrfs_fs_closing(root->fs_info)) { | |
108 | block_group->inode = igrab(inode); | |
109 | block_group->iref = 1; | |
110 | } | |
111 | spin_unlock(&block_group->lock); | |
112 | ||
113 | return inode; | |
114 | } | |
115 | ||
116 | int __create_free_space_inode(struct btrfs_root *root, | |
117 | struct btrfs_trans_handle *trans, | |
118 | struct btrfs_path *path, u64 ino, u64 offset) | |
119 | { | |
120 | struct btrfs_key key; | |
121 | struct btrfs_disk_key disk_key; | |
122 | struct btrfs_free_space_header *header; | |
123 | struct btrfs_inode_item *inode_item; | |
124 | struct extent_buffer *leaf; | |
125 | int ret; | |
126 | ||
127 | ret = btrfs_insert_empty_inode(trans, root, path, ino); | |
128 | if (ret) | |
129 | return ret; | |
130 | ||
131 | leaf = path->nodes[0]; | |
132 | inode_item = btrfs_item_ptr(leaf, path->slots[0], | |
133 | struct btrfs_inode_item); | |
134 | btrfs_item_key(leaf, &disk_key, path->slots[0]); | |
135 | memset_extent_buffer(leaf, 0, (unsigned long)inode_item, | |
136 | sizeof(*inode_item)); | |
137 | btrfs_set_inode_generation(leaf, inode_item, trans->transid); | |
138 | btrfs_set_inode_size(leaf, inode_item, 0); | |
139 | btrfs_set_inode_nbytes(leaf, inode_item, 0); | |
140 | btrfs_set_inode_uid(leaf, inode_item, 0); | |
141 | btrfs_set_inode_gid(leaf, inode_item, 0); | |
142 | btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600); | |
143 | btrfs_set_inode_flags(leaf, inode_item, BTRFS_INODE_NOCOMPRESS | | |
144 | BTRFS_INODE_PREALLOC); | |
145 | btrfs_set_inode_nlink(leaf, inode_item, 1); | |
146 | btrfs_set_inode_transid(leaf, inode_item, trans->transid); | |
147 | btrfs_set_inode_block_group(leaf, inode_item, offset); | |
148 | btrfs_mark_buffer_dirty(leaf); | |
149 | btrfs_release_path(path); | |
150 | ||
151 | key.objectid = BTRFS_FREE_SPACE_OBJECTID; | |
152 | key.offset = offset; | |
153 | key.type = 0; | |
154 | ||
155 | ret = btrfs_insert_empty_item(trans, root, path, &key, | |
156 | sizeof(struct btrfs_free_space_header)); | |
157 | if (ret < 0) { | |
158 | btrfs_release_path(path); | |
159 | return ret; | |
160 | } | |
161 | leaf = path->nodes[0]; | |
162 | header = btrfs_item_ptr(leaf, path->slots[0], | |
163 | struct btrfs_free_space_header); | |
164 | memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header)); | |
165 | btrfs_set_free_space_key(leaf, header, &disk_key); | |
166 | btrfs_mark_buffer_dirty(leaf); | |
167 | btrfs_release_path(path); | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | int create_free_space_inode(struct btrfs_root *root, | |
173 | struct btrfs_trans_handle *trans, | |
174 | struct btrfs_block_group_cache *block_group, | |
175 | struct btrfs_path *path) | |
176 | { | |
177 | int ret; | |
178 | u64 ino; | |
179 | ||
180 | ret = btrfs_find_free_objectid(root, &ino); | |
181 | if (ret < 0) | |
182 | return ret; | |
183 | ||
184 | return __create_free_space_inode(root, trans, path, ino, | |
185 | block_group->key.objectid); | |
186 | } | |
187 | ||
188 | int btrfs_truncate_free_space_cache(struct btrfs_root *root, | |
189 | struct btrfs_trans_handle *trans, | |
190 | struct btrfs_path *path, | |
191 | struct inode *inode) | |
192 | { | |
193 | loff_t oldsize; | |
194 | int ret = 0; | |
195 | ||
196 | trans->block_rsv = root->orphan_block_rsv; | |
197 | ret = btrfs_block_rsv_check(trans, root, | |
198 | root->orphan_block_rsv, | |
199 | 0, 5); | |
200 | if (ret) | |
201 | return ret; | |
202 | ||
203 | oldsize = i_size_read(inode); | |
204 | btrfs_i_size_write(inode, 0); | |
205 | truncate_pagecache(inode, oldsize, 0); | |
206 | ||
207 | /* | |
208 | * We don't need an orphan item because truncating the free space cache | |
209 | * will never be split across transactions. | |
210 | */ | |
211 | ret = btrfs_truncate_inode_items(trans, root, inode, | |
212 | 0, BTRFS_EXTENT_DATA_KEY); | |
213 | if (ret) { | |
214 | WARN_ON(1); | |
215 | return ret; | |
216 | } | |
217 | ||
218 | ret = btrfs_update_inode(trans, root, inode); | |
219 | return ret; | |
220 | } | |
221 | ||
222 | static int readahead_cache(struct inode *inode) | |
223 | { | |
224 | struct file_ra_state *ra; | |
225 | unsigned long last_index; | |
226 | ||
227 | ra = kzalloc(sizeof(*ra), GFP_NOFS); | |
228 | if (!ra) | |
229 | return -ENOMEM; | |
230 | ||
231 | file_ra_state_init(ra, inode->i_mapping); | |
232 | last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT; | |
233 | ||
234 | page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index); | |
235 | ||
236 | kfree(ra); | |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
241 | int __load_free_space_cache(struct btrfs_root *root, struct inode *inode, | |
242 | struct btrfs_free_space_ctl *ctl, | |
243 | struct btrfs_path *path, u64 offset) | |
244 | { | |
245 | struct btrfs_free_space_header *header; | |
246 | struct extent_buffer *leaf; | |
247 | struct page *page; | |
248 | struct btrfs_key key; | |
249 | struct list_head bitmaps; | |
250 | u64 num_entries; | |
251 | u64 num_bitmaps; | |
252 | u64 generation; | |
253 | pgoff_t index = 0; | |
254 | int ret = 0; | |
255 | ||
256 | INIT_LIST_HEAD(&bitmaps); | |
257 | ||
258 | /* Nothing in the space cache, goodbye */ | |
259 | if (!i_size_read(inode)) | |
260 | goto out; | |
261 | ||
262 | key.objectid = BTRFS_FREE_SPACE_OBJECTID; | |
263 | key.offset = offset; | |
264 | key.type = 0; | |
265 | ||
266 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
267 | if (ret < 0) | |
268 | goto out; | |
269 | else if (ret > 0) { | |
270 | btrfs_release_path(path); | |
271 | ret = 0; | |
272 | goto out; | |
273 | } | |
274 | ||
275 | ret = -1; | |
276 | ||
277 | leaf = path->nodes[0]; | |
278 | header = btrfs_item_ptr(leaf, path->slots[0], | |
279 | struct btrfs_free_space_header); | |
280 | num_entries = btrfs_free_space_entries(leaf, header); | |
281 | num_bitmaps = btrfs_free_space_bitmaps(leaf, header); | |
282 | generation = btrfs_free_space_generation(leaf, header); | |
283 | btrfs_release_path(path); | |
284 | ||
285 | if (BTRFS_I(inode)->generation != generation) { | |
286 | printk(KERN_ERR "btrfs: free space inode generation (%llu) did" | |
287 | " not match free space cache generation (%llu)\n", | |
288 | (unsigned long long)BTRFS_I(inode)->generation, | |
289 | (unsigned long long)generation); | |
290 | goto out; | |
291 | } | |
292 | ||
293 | if (!num_entries) | |
294 | goto out; | |
295 | ||
296 | ret = readahead_cache(inode); | |
297 | if (ret) | |
298 | goto out; | |
299 | ||
300 | while (1) { | |
301 | struct btrfs_free_space_entry *entry; | |
302 | struct btrfs_free_space *e; | |
303 | void *addr; | |
304 | unsigned long offset = 0; | |
305 | int need_loop = 0; | |
306 | ||
307 | if (!num_entries && !num_bitmaps) | |
308 | break; | |
309 | ||
310 | page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); | |
311 | if (!page) | |
312 | goto free_cache; | |
313 | ||
314 | if (!PageUptodate(page)) { | |
315 | btrfs_readpage(NULL, page); | |
316 | lock_page(page); | |
317 | if (!PageUptodate(page)) { | |
318 | unlock_page(page); | |
319 | page_cache_release(page); | |
320 | printk(KERN_ERR "btrfs: error reading free " | |
321 | "space cache\n"); | |
322 | goto free_cache; | |
323 | } | |
324 | } | |
325 | addr = kmap(page); | |
326 | ||
327 | if (index == 0) { | |
328 | u64 *gen; | |
329 | ||
330 | /* | |
331 | * We put a bogus crc in the front of the first page in | |
332 | * case old kernels try to mount a fs with the new | |
333 | * format to make sure they discard the cache. | |
334 | */ | |
335 | addr += sizeof(u64); | |
336 | offset += sizeof(u64); | |
337 | ||
338 | gen = addr; | |
339 | if (*gen != BTRFS_I(inode)->generation) { | |
340 | printk(KERN_ERR "btrfs: space cache generation" | |
341 | " (%llu) does not match inode (%llu)\n", | |
342 | (unsigned long long)*gen, | |
343 | (unsigned long long) | |
344 | BTRFS_I(inode)->generation); | |
345 | kunmap(page); | |
346 | unlock_page(page); | |
347 | page_cache_release(page); | |
348 | goto free_cache; | |
349 | } | |
350 | addr += sizeof(u64); | |
351 | offset += sizeof(u64); | |
352 | } | |
353 | entry = addr; | |
354 | ||
355 | while (1) { | |
356 | if (!num_entries) | |
357 | break; | |
358 | ||
359 | need_loop = 1; | |
360 | e = kmem_cache_zalloc(btrfs_free_space_cachep, | |
361 | GFP_NOFS); | |
362 | if (!e) { | |
363 | kunmap(page); | |
364 | unlock_page(page); | |
365 | page_cache_release(page); | |
366 | goto free_cache; | |
367 | } | |
368 | ||
369 | e->offset = le64_to_cpu(entry->offset); | |
370 | e->bytes = le64_to_cpu(entry->bytes); | |
371 | if (!e->bytes) { | |
372 | kunmap(page); | |
373 | kmem_cache_free(btrfs_free_space_cachep, e); | |
374 | unlock_page(page); | |
375 | page_cache_release(page); | |
376 | goto free_cache; | |
377 | } | |
378 | ||
379 | if (entry->type == BTRFS_FREE_SPACE_EXTENT) { | |
380 | spin_lock(&ctl->tree_lock); | |
381 | ret = link_free_space(ctl, e); | |
382 | spin_unlock(&ctl->tree_lock); | |
383 | if (ret) { | |
384 | printk(KERN_ERR "Duplicate entries in " | |
385 | "free space cache, dumping\n"); | |
386 | kunmap(page); | |
387 | unlock_page(page); | |
388 | page_cache_release(page); | |
389 | goto free_cache; | |
390 | } | |
391 | } else { | |
392 | e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); | |
393 | if (!e->bitmap) { | |
394 | kunmap(page); | |
395 | kmem_cache_free( | |
396 | btrfs_free_space_cachep, e); | |
397 | unlock_page(page); | |
398 | page_cache_release(page); | |
399 | goto free_cache; | |
400 | } | |
401 | spin_lock(&ctl->tree_lock); | |
402 | ret = link_free_space(ctl, e); | |
403 | ctl->total_bitmaps++; | |
404 | ctl->op->recalc_thresholds(ctl); | |
405 | spin_unlock(&ctl->tree_lock); | |
406 | if (ret) { | |
407 | printk(KERN_ERR "Duplicate entries in " | |
408 | "free space cache, dumping\n"); | |
409 | kunmap(page); | |
410 | unlock_page(page); | |
411 | page_cache_release(page); | |
412 | goto free_cache; | |
413 | } | |
414 | list_add_tail(&e->list, &bitmaps); | |
415 | } | |
416 | ||
417 | num_entries--; | |
418 | offset += sizeof(struct btrfs_free_space_entry); | |
419 | if (offset + sizeof(struct btrfs_free_space_entry) >= | |
420 | PAGE_CACHE_SIZE) | |
421 | break; | |
422 | entry++; | |
423 | } | |
424 | ||
425 | /* | |
426 | * We read an entry out of this page, we need to move on to the | |
427 | * next page. | |
428 | */ | |
429 | if (need_loop) { | |
430 | kunmap(page); | |
431 | goto next; | |
432 | } | |
433 | ||
434 | /* | |
435 | * We add the bitmaps at the end of the entries in order that | |
436 | * the bitmap entries are added to the cache. | |
437 | */ | |
438 | e = list_entry(bitmaps.next, struct btrfs_free_space, list); | |
439 | list_del_init(&e->list); | |
440 | memcpy(e->bitmap, addr, PAGE_CACHE_SIZE); | |
441 | kunmap(page); | |
442 | num_bitmaps--; | |
443 | next: | |
444 | unlock_page(page); | |
445 | page_cache_release(page); | |
446 | index++; | |
447 | } | |
448 | ||
449 | ret = 1; | |
450 | out: | |
451 | return ret; | |
452 | free_cache: | |
453 | __btrfs_remove_free_space_cache(ctl); | |
454 | goto out; | |
455 | } | |
456 | ||
457 | int load_free_space_cache(struct btrfs_fs_info *fs_info, | |
458 | struct btrfs_block_group_cache *block_group) | |
459 | { | |
460 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
461 | struct btrfs_root *root = fs_info->tree_root; | |
462 | struct inode *inode; | |
463 | struct btrfs_path *path; | |
464 | int ret; | |
465 | bool matched; | |
466 | u64 used = btrfs_block_group_used(&block_group->item); | |
467 | ||
468 | /* | |
469 | * If we're unmounting then just return, since this does a search on the | |
470 | * normal root and not the commit root and we could deadlock. | |
471 | */ | |
472 | if (btrfs_fs_closing(fs_info)) | |
473 | return 0; | |
474 | ||
475 | /* | |
476 | * If this block group has been marked to be cleared for one reason or | |
477 | * another then we can't trust the on disk cache, so just return. | |
478 | */ | |
479 | spin_lock(&block_group->lock); | |
480 | if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) { | |
481 | spin_unlock(&block_group->lock); | |
482 | return 0; | |
483 | } | |
484 | spin_unlock(&block_group->lock); | |
485 | ||
486 | path = btrfs_alloc_path(); | |
487 | if (!path) | |
488 | return 0; | |
489 | ||
490 | inode = lookup_free_space_inode(root, block_group, path); | |
491 | if (IS_ERR(inode)) { | |
492 | btrfs_free_path(path); | |
493 | return 0; | |
494 | } | |
495 | ||
496 | ret = __load_free_space_cache(fs_info->tree_root, inode, ctl, | |
497 | path, block_group->key.objectid); | |
498 | btrfs_free_path(path); | |
499 | if (ret <= 0) | |
500 | goto out; | |
501 | ||
502 | spin_lock(&ctl->tree_lock); | |
503 | matched = (ctl->free_space == (block_group->key.offset - used - | |
504 | block_group->bytes_super)); | |
505 | spin_unlock(&ctl->tree_lock); | |
506 | ||
507 | if (!matched) { | |
508 | __btrfs_remove_free_space_cache(ctl); | |
509 | printk(KERN_ERR "block group %llu has an wrong amount of free " | |
510 | "space\n", block_group->key.objectid); | |
511 | ret = -1; | |
512 | } | |
513 | out: | |
514 | if (ret < 0) { | |
515 | /* This cache is bogus, make sure it gets cleared */ | |
516 | spin_lock(&block_group->lock); | |
517 | block_group->disk_cache_state = BTRFS_DC_CLEAR; | |
518 | spin_unlock(&block_group->lock); | |
519 | ret = 0; | |
520 | ||
521 | printk(KERN_ERR "btrfs: failed to load free space cache " | |
522 | "for block group %llu\n", block_group->key.objectid); | |
523 | } | |
524 | ||
525 | iput(inode); | |
526 | return ret; | |
527 | } | |
528 | ||
529 | int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, | |
530 | struct btrfs_free_space_ctl *ctl, | |
531 | struct btrfs_block_group_cache *block_group, | |
532 | struct btrfs_trans_handle *trans, | |
533 | struct btrfs_path *path, u64 offset) | |
534 | { | |
535 | struct btrfs_free_space_header *header; | |
536 | struct extent_buffer *leaf; | |
537 | struct rb_node *node; | |
538 | struct list_head *pos, *n; | |
539 | struct page **pages; | |
540 | struct page *page; | |
541 | struct extent_state *cached_state = NULL; | |
542 | struct btrfs_free_cluster *cluster = NULL; | |
543 | struct extent_io_tree *unpin = NULL; | |
544 | struct list_head bitmap_list; | |
545 | struct btrfs_key key; | |
546 | u64 start, end, len; | |
547 | u64 bytes = 0; | |
548 | u32 crc = ~(u32)0; | |
549 | int index = 0, num_pages = 0; | |
550 | int entries = 0; | |
551 | int bitmaps = 0; | |
552 | int ret = -1; | |
553 | bool next_page = false; | |
554 | bool out_of_space = false; | |
555 | ||
556 | INIT_LIST_HEAD(&bitmap_list); | |
557 | ||
558 | node = rb_first(&ctl->free_space_offset); | |
559 | if (!node) | |
560 | return 0; | |
561 | ||
562 | if (!i_size_read(inode)) | |
563 | return -1; | |
564 | ||
565 | num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> | |
566 | PAGE_CACHE_SHIFT; | |
567 | ||
568 | filemap_write_and_wait(inode->i_mapping); | |
569 | btrfs_wait_ordered_range(inode, inode->i_size & | |
570 | ~(root->sectorsize - 1), (u64)-1); | |
571 | ||
572 | pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS); | |
573 | if (!pages) | |
574 | return -1; | |
575 | ||
576 | /* Get the cluster for this block_group if it exists */ | |
577 | if (block_group && !list_empty(&block_group->cluster_list)) | |
578 | cluster = list_entry(block_group->cluster_list.next, | |
579 | struct btrfs_free_cluster, | |
580 | block_group_list); | |
581 | ||
582 | /* | |
583 | * We shouldn't have switched the pinned extents yet so this is the | |
584 | * right one | |
585 | */ | |
586 | unpin = root->fs_info->pinned_extents; | |
587 | ||
588 | /* | |
589 | * Lock all pages first so we can lock the extent safely. | |
590 | * | |
591 | * NOTE: Because we hold the ref the entire time we're going to write to | |
592 | * the page find_get_page should never fail, so we don't do a check | |
593 | * after find_get_page at this point. Just putting this here so people | |
594 | * know and don't freak out. | |
595 | */ | |
596 | while (index < num_pages) { | |
597 | page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); | |
598 | if (!page) { | |
599 | int i; | |
600 | ||
601 | for (i = 0; i < num_pages; i++) { | |
602 | unlock_page(pages[i]); | |
603 | page_cache_release(pages[i]); | |
604 | } | |
605 | goto out; | |
606 | } | |
607 | pages[index] = page; | |
608 | index++; | |
609 | } | |
610 | ||
611 | index = 0; | |
612 | lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, | |
613 | 0, &cached_state, GFP_NOFS); | |
614 | ||
615 | /* | |
616 | * When searching for pinned extents, we need to start at our start | |
617 | * offset. | |
618 | */ | |
619 | if (block_group) | |
620 | start = block_group->key.objectid; | |
621 | ||
622 | /* Write out the extent entries */ | |
623 | do { | |
624 | struct btrfs_free_space_entry *entry; | |
625 | void *addr, *orig; | |
626 | unsigned long offset = 0; | |
627 | ||
628 | next_page = false; | |
629 | ||
630 | if (index >= num_pages) { | |
631 | out_of_space = true; | |
632 | break; | |
633 | } | |
634 | ||
635 | page = pages[index]; | |
636 | ||
637 | orig = addr = kmap(page); | |
638 | if (index == 0) { | |
639 | u64 *gen; | |
640 | ||
641 | /* | |
642 | * We're going to put in a bogus crc for this page to | |
643 | * make sure that old kernels who aren't aware of this | |
644 | * format will be sure to discard the cache. | |
645 | */ | |
646 | addr += sizeof(u64); | |
647 | offset += sizeof(u64); | |
648 | ||
649 | gen = addr; | |
650 | *gen = trans->transid; | |
651 | addr += sizeof(u64); | |
652 | offset += sizeof(u64); | |
653 | } | |
654 | entry = addr; | |
655 | ||
656 | memset(addr, 0, PAGE_CACHE_SIZE - offset); | |
657 | while (node && !next_page) { | |
658 | struct btrfs_free_space *e; | |
659 | ||
660 | e = rb_entry(node, struct btrfs_free_space, offset_index); | |
661 | entries++; | |
662 | ||
663 | entry->offset = cpu_to_le64(e->offset); | |
664 | entry->bytes = cpu_to_le64(e->bytes); | |
665 | if (e->bitmap) { | |
666 | entry->type = BTRFS_FREE_SPACE_BITMAP; | |
667 | list_add_tail(&e->list, &bitmap_list); | |
668 | bitmaps++; | |
669 | } else { | |
670 | entry->type = BTRFS_FREE_SPACE_EXTENT; | |
671 | } | |
672 | node = rb_next(node); | |
673 | if (!node && cluster) { | |
674 | node = rb_first(&cluster->root); | |
675 | cluster = NULL; | |
676 | } | |
677 | offset += sizeof(struct btrfs_free_space_entry); | |
678 | if (offset + sizeof(struct btrfs_free_space_entry) >= | |
679 | PAGE_CACHE_SIZE) | |
680 | next_page = true; | |
681 | entry++; | |
682 | } | |
683 | ||
684 | /* | |
685 | * We want to add any pinned extents to our free space cache | |
686 | * so we don't leak the space | |
687 | */ | |
688 | while (block_group && !next_page && | |
689 | (start < block_group->key.objectid + | |
690 | block_group->key.offset)) { | |
691 | ret = find_first_extent_bit(unpin, start, &start, &end, | |
692 | EXTENT_DIRTY); | |
693 | if (ret) { | |
694 | ret = 0; | |
695 | break; | |
696 | } | |
697 | ||
698 | /* This pinned extent is out of our range */ | |
699 | if (start >= block_group->key.objectid + | |
700 | block_group->key.offset) | |
701 | break; | |
702 | ||
703 | len = block_group->key.objectid + | |
704 | block_group->key.offset - start; | |
705 | len = min(len, end + 1 - start); | |
706 | ||
707 | entries++; | |
708 | entry->offset = cpu_to_le64(start); | |
709 | entry->bytes = cpu_to_le64(len); | |
710 | entry->type = BTRFS_FREE_SPACE_EXTENT; | |
711 | ||
712 | start = end + 1; | |
713 | offset += sizeof(struct btrfs_free_space_entry); | |
714 | if (offset + sizeof(struct btrfs_free_space_entry) >= | |
715 | PAGE_CACHE_SIZE) | |
716 | next_page = true; | |
717 | entry++; | |
718 | } | |
719 | ||
720 | /* Generate bogus crc value */ | |
721 | if (index == 0) { | |
722 | u32 *tmp; | |
723 | crc = btrfs_csum_data(root, orig + sizeof(u64), crc, | |
724 | PAGE_CACHE_SIZE - sizeof(u64)); | |
725 | btrfs_csum_final(crc, (char *)&crc); | |
726 | crc++; | |
727 | tmp = orig; | |
728 | *tmp = crc; | |
729 | } | |
730 | ||
731 | kunmap(page); | |
732 | ||
733 | bytes += PAGE_CACHE_SIZE; | |
734 | ||
735 | index++; | |
736 | } while (node || next_page); | |
737 | ||
738 | /* Write out the bitmaps */ | |
739 | list_for_each_safe(pos, n, &bitmap_list) { | |
740 | void *addr; | |
741 | struct btrfs_free_space *entry = | |
742 | list_entry(pos, struct btrfs_free_space, list); | |
743 | ||
744 | if (index >= num_pages) { | |
745 | out_of_space = true; | |
746 | break; | |
747 | } | |
748 | page = pages[index]; | |
749 | ||
750 | addr = kmap(page); | |
751 | memcpy(addr, entry->bitmap, PAGE_CACHE_SIZE); | |
752 | kunmap(page); | |
753 | bytes += PAGE_CACHE_SIZE; | |
754 | ||
755 | list_del_init(&entry->list); | |
756 | index++; | |
757 | } | |
758 | ||
759 | if (out_of_space) { | |
760 | btrfs_drop_pages(pages, num_pages); | |
761 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, | |
762 | i_size_read(inode) - 1, &cached_state, | |
763 | GFP_NOFS); | |
764 | ret = 0; | |
765 | goto out; | |
766 | } | |
767 | ||
768 | /* Zero out the rest of the pages just to make sure */ | |
769 | while (index < num_pages) { | |
770 | void *addr; | |
771 | ||
772 | page = pages[index]; | |
773 | addr = kmap(page); | |
774 | memset(addr, 0, PAGE_CACHE_SIZE); | |
775 | kunmap(page); | |
776 | bytes += PAGE_CACHE_SIZE; | |
777 | index++; | |
778 | } | |
779 | ||
780 | ret = btrfs_dirty_pages(root, inode, pages, num_pages, 0, | |
781 | bytes, &cached_state); | |
782 | btrfs_drop_pages(pages, num_pages); | |
783 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, | |
784 | i_size_read(inode) - 1, &cached_state, GFP_NOFS); | |
785 | ||
786 | if (ret) { | |
787 | ret = 0; | |
788 | goto out; | |
789 | } | |
790 | ||
791 | BTRFS_I(inode)->generation = trans->transid; | |
792 | ||
793 | filemap_write_and_wait(inode->i_mapping); | |
794 | ||
795 | key.objectid = BTRFS_FREE_SPACE_OBJECTID; | |
796 | key.offset = offset; | |
797 | key.type = 0; | |
798 | ||
799 | ret = btrfs_search_slot(trans, root, &key, path, 1, 1); | |
800 | if (ret < 0) { | |
801 | ret = -1; | |
802 | clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, | |
803 | EXTENT_DIRTY | EXTENT_DELALLOC | | |
804 | EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS); | |
805 | goto out; | |
806 | } | |
807 | leaf = path->nodes[0]; | |
808 | if (ret > 0) { | |
809 | struct btrfs_key found_key; | |
810 | BUG_ON(!path->slots[0]); | |
811 | path->slots[0]--; | |
812 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
813 | if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID || | |
814 | found_key.offset != offset) { | |
815 | ret = -1; | |
816 | clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, | |
817 | EXTENT_DIRTY | EXTENT_DELALLOC | | |
818 | EXTENT_DO_ACCOUNTING, 0, 0, NULL, | |
819 | GFP_NOFS); | |
820 | btrfs_release_path(path); | |
821 | goto out; | |
822 | } | |
823 | } | |
824 | header = btrfs_item_ptr(leaf, path->slots[0], | |
825 | struct btrfs_free_space_header); | |
826 | btrfs_set_free_space_entries(leaf, header, entries); | |
827 | btrfs_set_free_space_bitmaps(leaf, header, bitmaps); | |
828 | btrfs_set_free_space_generation(leaf, header, trans->transid); | |
829 | btrfs_mark_buffer_dirty(leaf); | |
830 | btrfs_release_path(path); | |
831 | ||
832 | ret = 1; | |
833 | ||
834 | out: | |
835 | kfree(pages); | |
836 | if (ret != 1) { | |
837 | invalidate_inode_pages2_range(inode->i_mapping, 0, index); | |
838 | BTRFS_I(inode)->generation = 0; | |
839 | } | |
840 | btrfs_update_inode(trans, root, inode); | |
841 | return ret; | |
842 | } | |
843 | ||
844 | int btrfs_write_out_cache(struct btrfs_root *root, | |
845 | struct btrfs_trans_handle *trans, | |
846 | struct btrfs_block_group_cache *block_group, | |
847 | struct btrfs_path *path) | |
848 | { | |
849 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
850 | struct inode *inode; | |
851 | int ret = 0; | |
852 | ||
853 | root = root->fs_info->tree_root; | |
854 | ||
855 | spin_lock(&block_group->lock); | |
856 | if (block_group->disk_cache_state < BTRFS_DC_SETUP) { | |
857 | spin_unlock(&block_group->lock); | |
858 | return 0; | |
859 | } | |
860 | spin_unlock(&block_group->lock); | |
861 | ||
862 | inode = lookup_free_space_inode(root, block_group, path); | |
863 | if (IS_ERR(inode)) | |
864 | return 0; | |
865 | ||
866 | ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans, | |
867 | path, block_group->key.objectid); | |
868 | if (ret < 0) { | |
869 | spin_lock(&block_group->lock); | |
870 | block_group->disk_cache_state = BTRFS_DC_ERROR; | |
871 | spin_unlock(&block_group->lock); | |
872 | ret = 0; | |
873 | ||
874 | printk(KERN_ERR "btrfs: failed to write free space cace " | |
875 | "for block group %llu\n", block_group->key.objectid); | |
876 | } | |
877 | ||
878 | iput(inode); | |
879 | return ret; | |
880 | } | |
881 | ||
882 | static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit, | |
883 | u64 offset) | |
884 | { | |
885 | BUG_ON(offset < bitmap_start); | |
886 | offset -= bitmap_start; | |
887 | return (unsigned long)(div_u64(offset, unit)); | |
888 | } | |
889 | ||
890 | static inline unsigned long bytes_to_bits(u64 bytes, u32 unit) | |
891 | { | |
892 | return (unsigned long)(div_u64(bytes, unit)); | |
893 | } | |
894 | ||
895 | static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl, | |
896 | u64 offset) | |
897 | { | |
898 | u64 bitmap_start; | |
899 | u64 bytes_per_bitmap; | |
900 | ||
901 | bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit; | |
902 | bitmap_start = offset - ctl->start; | |
903 | bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap); | |
904 | bitmap_start *= bytes_per_bitmap; | |
905 | bitmap_start += ctl->start; | |
906 | ||
907 | return bitmap_start; | |
908 | } | |
909 | ||
910 | static int tree_insert_offset(struct rb_root *root, u64 offset, | |
911 | struct rb_node *node, int bitmap) | |
912 | { | |
913 | struct rb_node **p = &root->rb_node; | |
914 | struct rb_node *parent = NULL; | |
915 | struct btrfs_free_space *info; | |
916 | ||
917 | while (*p) { | |
918 | parent = *p; | |
919 | info = rb_entry(parent, struct btrfs_free_space, offset_index); | |
920 | ||
921 | if (offset < info->offset) { | |
922 | p = &(*p)->rb_left; | |
923 | } else if (offset > info->offset) { | |
924 | p = &(*p)->rb_right; | |
925 | } else { | |
926 | /* | |
927 | * we could have a bitmap entry and an extent entry | |
928 | * share the same offset. If this is the case, we want | |
929 | * the extent entry to always be found first if we do a | |
930 | * linear search through the tree, since we want to have | |
931 | * the quickest allocation time, and allocating from an | |
932 | * extent is faster than allocating from a bitmap. So | |
933 | * if we're inserting a bitmap and we find an entry at | |
934 | * this offset, we want to go right, or after this entry | |
935 | * logically. If we are inserting an extent and we've | |
936 | * found a bitmap, we want to go left, or before | |
937 | * logically. | |
938 | */ | |
939 | if (bitmap) { | |
940 | if (info->bitmap) { | |
941 | WARN_ON_ONCE(1); | |
942 | return -EEXIST; | |
943 | } | |
944 | p = &(*p)->rb_right; | |
945 | } else { | |
946 | if (!info->bitmap) { | |
947 | WARN_ON_ONCE(1); | |
948 | return -EEXIST; | |
949 | } | |
950 | p = &(*p)->rb_left; | |
951 | } | |
952 | } | |
953 | } | |
954 | ||
955 | rb_link_node(node, parent, p); | |
956 | rb_insert_color(node, root); | |
957 | ||
958 | return 0; | |
959 | } | |
960 | ||
961 | /* | |
962 | * searches the tree for the given offset. | |
963 | * | |
964 | * fuzzy - If this is set, then we are trying to make an allocation, and we just | |
965 | * want a section that has at least bytes size and comes at or after the given | |
966 | * offset. | |
967 | */ | |
968 | static struct btrfs_free_space * | |
969 | tree_search_offset(struct btrfs_free_space_ctl *ctl, | |
970 | u64 offset, int bitmap_only, int fuzzy) | |
971 | { | |
972 | struct rb_node *n = ctl->free_space_offset.rb_node; | |
973 | struct btrfs_free_space *entry, *prev = NULL; | |
974 | ||
975 | /* find entry that is closest to the 'offset' */ | |
976 | while (1) { | |
977 | if (!n) { | |
978 | entry = NULL; | |
979 | break; | |
980 | } | |
981 | ||
982 | entry = rb_entry(n, struct btrfs_free_space, offset_index); | |
983 | prev = entry; | |
984 | ||
985 | if (offset < entry->offset) | |
986 | n = n->rb_left; | |
987 | else if (offset > entry->offset) | |
988 | n = n->rb_right; | |
989 | else | |
990 | break; | |
991 | } | |
992 | ||
993 | if (bitmap_only) { | |
994 | if (!entry) | |
995 | return NULL; | |
996 | if (entry->bitmap) | |
997 | return entry; | |
998 | ||
999 | /* | |
1000 | * bitmap entry and extent entry may share same offset, | |
1001 | * in that case, bitmap entry comes after extent entry. | |
1002 | */ | |
1003 | n = rb_next(n); | |
1004 | if (!n) | |
1005 | return NULL; | |
1006 | entry = rb_entry(n, struct btrfs_free_space, offset_index); | |
1007 | if (entry->offset != offset) | |
1008 | return NULL; | |
1009 | ||
1010 | WARN_ON(!entry->bitmap); | |
1011 | return entry; | |
1012 | } else if (entry) { | |
1013 | if (entry->bitmap) { | |
1014 | /* | |
1015 | * if previous extent entry covers the offset, | |
1016 | * we should return it instead of the bitmap entry | |
1017 | */ | |
1018 | n = &entry->offset_index; | |
1019 | while (1) { | |
1020 | n = rb_prev(n); | |
1021 | if (!n) | |
1022 | break; | |
1023 | prev = rb_entry(n, struct btrfs_free_space, | |
1024 | offset_index); | |
1025 | if (!prev->bitmap) { | |
1026 | if (prev->offset + prev->bytes > offset) | |
1027 | entry = prev; | |
1028 | break; | |
1029 | } | |
1030 | } | |
1031 | } | |
1032 | return entry; | |
1033 | } | |
1034 | ||
1035 | if (!prev) | |
1036 | return NULL; | |
1037 | ||
1038 | /* find last entry before the 'offset' */ | |
1039 | entry = prev; | |
1040 | if (entry->offset > offset) { | |
1041 | n = rb_prev(&entry->offset_index); | |
1042 | if (n) { | |
1043 | entry = rb_entry(n, struct btrfs_free_space, | |
1044 | offset_index); | |
1045 | BUG_ON(entry->offset > offset); | |
1046 | } else { | |
1047 | if (fuzzy) | |
1048 | return entry; | |
1049 | else | |
1050 | return NULL; | |
1051 | } | |
1052 | } | |
1053 | ||
1054 | if (entry->bitmap) { | |
1055 | n = &entry->offset_index; | |
1056 | while (1) { | |
1057 | n = rb_prev(n); | |
1058 | if (!n) | |
1059 | break; | |
1060 | prev = rb_entry(n, struct btrfs_free_space, | |
1061 | offset_index); | |
1062 | if (!prev->bitmap) { | |
1063 | if (prev->offset + prev->bytes > offset) | |
1064 | return prev; | |
1065 | break; | |
1066 | } | |
1067 | } | |
1068 | if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset) | |
1069 | return entry; | |
1070 | } else if (entry->offset + entry->bytes > offset) | |
1071 | return entry; | |
1072 | ||
1073 | if (!fuzzy) | |
1074 | return NULL; | |
1075 | ||
1076 | while (1) { | |
1077 | if (entry->bitmap) { | |
1078 | if (entry->offset + BITS_PER_BITMAP * | |
1079 | ctl->unit > offset) | |
1080 | break; | |
1081 | } else { | |
1082 | if (entry->offset + entry->bytes > offset) | |
1083 | break; | |
1084 | } | |
1085 | ||
1086 | n = rb_next(&entry->offset_index); | |
1087 | if (!n) | |
1088 | return NULL; | |
1089 | entry = rb_entry(n, struct btrfs_free_space, offset_index); | |
1090 | } | |
1091 | return entry; | |
1092 | } | |
1093 | ||
1094 | static inline void | |
1095 | __unlink_free_space(struct btrfs_free_space_ctl *ctl, | |
1096 | struct btrfs_free_space *info) | |
1097 | { | |
1098 | rb_erase(&info->offset_index, &ctl->free_space_offset); | |
1099 | ctl->free_extents--; | |
1100 | } | |
1101 | ||
1102 | static void unlink_free_space(struct btrfs_free_space_ctl *ctl, | |
1103 | struct btrfs_free_space *info) | |
1104 | { | |
1105 | __unlink_free_space(ctl, info); | |
1106 | ctl->free_space -= info->bytes; | |
1107 | } | |
1108 | ||
1109 | static int link_free_space(struct btrfs_free_space_ctl *ctl, | |
1110 | struct btrfs_free_space *info) | |
1111 | { | |
1112 | int ret = 0; | |
1113 | ||
1114 | BUG_ON(!info->bitmap && !info->bytes); | |
1115 | ret = tree_insert_offset(&ctl->free_space_offset, info->offset, | |
1116 | &info->offset_index, (info->bitmap != NULL)); | |
1117 | if (ret) | |
1118 | return ret; | |
1119 | ||
1120 | ctl->free_space += info->bytes; | |
1121 | ctl->free_extents++; | |
1122 | return ret; | |
1123 | } | |
1124 | ||
1125 | static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) | |
1126 | { | |
1127 | struct btrfs_block_group_cache *block_group = ctl->private; | |
1128 | u64 max_bytes; | |
1129 | u64 bitmap_bytes; | |
1130 | u64 extent_bytes; | |
1131 | u64 size = block_group->key.offset; | |
1132 | u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize; | |
1133 | int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg); | |
1134 | ||
1135 | BUG_ON(ctl->total_bitmaps > max_bitmaps); | |
1136 | ||
1137 | /* | |
1138 | * The goal is to keep the total amount of memory used per 1gb of space | |
1139 | * at or below 32k, so we need to adjust how much memory we allow to be | |
1140 | * used by extent based free space tracking | |
1141 | */ | |
1142 | if (size < 1024 * 1024 * 1024) | |
1143 | max_bytes = MAX_CACHE_BYTES_PER_GIG; | |
1144 | else | |
1145 | max_bytes = MAX_CACHE_BYTES_PER_GIG * | |
1146 | div64_u64(size, 1024 * 1024 * 1024); | |
1147 | ||
1148 | /* | |
1149 | * we want to account for 1 more bitmap than what we have so we can make | |
1150 | * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as | |
1151 | * we add more bitmaps. | |
1152 | */ | |
1153 | bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE; | |
1154 | ||
1155 | if (bitmap_bytes >= max_bytes) { | |
1156 | ctl->extents_thresh = 0; | |
1157 | return; | |
1158 | } | |
1159 | ||
1160 | /* | |
1161 | * we want the extent entry threshold to always be at most 1/2 the maxw | |
1162 | * bytes we can have, or whatever is less than that. | |
1163 | */ | |
1164 | extent_bytes = max_bytes - bitmap_bytes; | |
1165 | extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2)); | |
1166 | ||
1167 | ctl->extents_thresh = | |
1168 | div64_u64(extent_bytes, (sizeof(struct btrfs_free_space))); | |
1169 | } | |
1170 | ||
1171 | static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl, | |
1172 | struct btrfs_free_space *info, u64 offset, | |
1173 | u64 bytes) | |
1174 | { | |
1175 | unsigned long start, count; | |
1176 | ||
1177 | start = offset_to_bit(info->offset, ctl->unit, offset); | |
1178 | count = bytes_to_bits(bytes, ctl->unit); | |
1179 | BUG_ON(start + count > BITS_PER_BITMAP); | |
1180 | ||
1181 | bitmap_clear(info->bitmap, start, count); | |
1182 | ||
1183 | info->bytes -= bytes; | |
1184 | ctl->free_space -= bytes; | |
1185 | } | |
1186 | ||
1187 | static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl, | |
1188 | struct btrfs_free_space *info, u64 offset, | |
1189 | u64 bytes) | |
1190 | { | |
1191 | unsigned long start, count; | |
1192 | ||
1193 | start = offset_to_bit(info->offset, ctl->unit, offset); | |
1194 | count = bytes_to_bits(bytes, ctl->unit); | |
1195 | BUG_ON(start + count > BITS_PER_BITMAP); | |
1196 | ||
1197 | bitmap_set(info->bitmap, start, count); | |
1198 | ||
1199 | info->bytes += bytes; | |
1200 | ctl->free_space += bytes; | |
1201 | } | |
1202 | ||
1203 | static int search_bitmap(struct btrfs_free_space_ctl *ctl, | |
1204 | struct btrfs_free_space *bitmap_info, u64 *offset, | |
1205 | u64 *bytes) | |
1206 | { | |
1207 | unsigned long found_bits = 0; | |
1208 | unsigned long bits, i; | |
1209 | unsigned long next_zero; | |
1210 | ||
1211 | i = offset_to_bit(bitmap_info->offset, ctl->unit, | |
1212 | max_t(u64, *offset, bitmap_info->offset)); | |
1213 | bits = bytes_to_bits(*bytes, ctl->unit); | |
1214 | ||
1215 | for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i); | |
1216 | i < BITS_PER_BITMAP; | |
1217 | i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i + 1)) { | |
1218 | next_zero = find_next_zero_bit(bitmap_info->bitmap, | |
1219 | BITS_PER_BITMAP, i); | |
1220 | if ((next_zero - i) >= bits) { | |
1221 | found_bits = next_zero - i; | |
1222 | break; | |
1223 | } | |
1224 | i = next_zero; | |
1225 | } | |
1226 | ||
1227 | if (found_bits) { | |
1228 | *offset = (u64)(i * ctl->unit) + bitmap_info->offset; | |
1229 | *bytes = (u64)(found_bits) * ctl->unit; | |
1230 | return 0; | |
1231 | } | |
1232 | ||
1233 | return -1; | |
1234 | } | |
1235 | ||
1236 | static struct btrfs_free_space * | |
1237 | find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes) | |
1238 | { | |
1239 | struct btrfs_free_space *entry; | |
1240 | struct rb_node *node; | |
1241 | int ret; | |
1242 | ||
1243 | if (!ctl->free_space_offset.rb_node) | |
1244 | return NULL; | |
1245 | ||
1246 | entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1); | |
1247 | if (!entry) | |
1248 | return NULL; | |
1249 | ||
1250 | for (node = &entry->offset_index; node; node = rb_next(node)) { | |
1251 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1252 | if (entry->bytes < *bytes) | |
1253 | continue; | |
1254 | ||
1255 | if (entry->bitmap) { | |
1256 | ret = search_bitmap(ctl, entry, offset, bytes); | |
1257 | if (!ret) | |
1258 | return entry; | |
1259 | continue; | |
1260 | } | |
1261 | ||
1262 | *offset = entry->offset; | |
1263 | *bytes = entry->bytes; | |
1264 | return entry; | |
1265 | } | |
1266 | ||
1267 | return NULL; | |
1268 | } | |
1269 | ||
1270 | static void add_new_bitmap(struct btrfs_free_space_ctl *ctl, | |
1271 | struct btrfs_free_space *info, u64 offset) | |
1272 | { | |
1273 | info->offset = offset_to_bitmap(ctl, offset); | |
1274 | info->bytes = 0; | |
1275 | link_free_space(ctl, info); | |
1276 | ctl->total_bitmaps++; | |
1277 | ||
1278 | ctl->op->recalc_thresholds(ctl); | |
1279 | } | |
1280 | ||
1281 | static void free_bitmap(struct btrfs_free_space_ctl *ctl, | |
1282 | struct btrfs_free_space *bitmap_info) | |
1283 | { | |
1284 | unlink_free_space(ctl, bitmap_info); | |
1285 | kfree(bitmap_info->bitmap); | |
1286 | kmem_cache_free(btrfs_free_space_cachep, bitmap_info); | |
1287 | ctl->total_bitmaps--; | |
1288 | ctl->op->recalc_thresholds(ctl); | |
1289 | } | |
1290 | ||
1291 | static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl, | |
1292 | struct btrfs_free_space *bitmap_info, | |
1293 | u64 *offset, u64 *bytes) | |
1294 | { | |
1295 | u64 end; | |
1296 | u64 search_start, search_bytes; | |
1297 | int ret; | |
1298 | ||
1299 | again: | |
1300 | end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1; | |
1301 | ||
1302 | /* | |
1303 | * XXX - this can go away after a few releases. | |
1304 | * | |
1305 | * since the only user of btrfs_remove_free_space is the tree logging | |
1306 | * stuff, and the only way to test that is under crash conditions, we | |
1307 | * want to have this debug stuff here just in case somethings not | |
1308 | * working. Search the bitmap for the space we are trying to use to | |
1309 | * make sure its actually there. If its not there then we need to stop | |
1310 | * because something has gone wrong. | |
1311 | */ | |
1312 | search_start = *offset; | |
1313 | search_bytes = *bytes; | |
1314 | search_bytes = min(search_bytes, end - search_start + 1); | |
1315 | ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes); | |
1316 | BUG_ON(ret < 0 || search_start != *offset); | |
1317 | ||
1318 | if (*offset > bitmap_info->offset && *offset + *bytes > end) { | |
1319 | bitmap_clear_bits(ctl, bitmap_info, *offset, end - *offset + 1); | |
1320 | *bytes -= end - *offset + 1; | |
1321 | *offset = end + 1; | |
1322 | } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) { | |
1323 | bitmap_clear_bits(ctl, bitmap_info, *offset, *bytes); | |
1324 | *bytes = 0; | |
1325 | } | |
1326 | ||
1327 | if (*bytes) { | |
1328 | struct rb_node *next = rb_next(&bitmap_info->offset_index); | |
1329 | if (!bitmap_info->bytes) | |
1330 | free_bitmap(ctl, bitmap_info); | |
1331 | ||
1332 | /* | |
1333 | * no entry after this bitmap, but we still have bytes to | |
1334 | * remove, so something has gone wrong. | |
1335 | */ | |
1336 | if (!next) | |
1337 | return -EINVAL; | |
1338 | ||
1339 | bitmap_info = rb_entry(next, struct btrfs_free_space, | |
1340 | offset_index); | |
1341 | ||
1342 | /* | |
1343 | * if the next entry isn't a bitmap we need to return to let the | |
1344 | * extent stuff do its work. | |
1345 | */ | |
1346 | if (!bitmap_info->bitmap) | |
1347 | return -EAGAIN; | |
1348 | ||
1349 | /* | |
1350 | * Ok the next item is a bitmap, but it may not actually hold | |
1351 | * the information for the rest of this free space stuff, so | |
1352 | * look for it, and if we don't find it return so we can try | |
1353 | * everything over again. | |
1354 | */ | |
1355 | search_start = *offset; | |
1356 | search_bytes = *bytes; | |
1357 | ret = search_bitmap(ctl, bitmap_info, &search_start, | |
1358 | &search_bytes); | |
1359 | if (ret < 0 || search_start != *offset) | |
1360 | return -EAGAIN; | |
1361 | ||
1362 | goto again; | |
1363 | } else if (!bitmap_info->bytes) | |
1364 | free_bitmap(ctl, bitmap_info); | |
1365 | ||
1366 | return 0; | |
1367 | } | |
1368 | ||
1369 | static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl, | |
1370 | struct btrfs_free_space *info, u64 offset, | |
1371 | u64 bytes) | |
1372 | { | |
1373 | u64 bytes_to_set = 0; | |
1374 | u64 end; | |
1375 | ||
1376 | end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit); | |
1377 | ||
1378 | bytes_to_set = min(end - offset, bytes); | |
1379 | ||
1380 | bitmap_set_bits(ctl, info, offset, bytes_to_set); | |
1381 | ||
1382 | return bytes_to_set; | |
1383 | ||
1384 | } | |
1385 | ||
1386 | static bool use_bitmap(struct btrfs_free_space_ctl *ctl, | |
1387 | struct btrfs_free_space *info) | |
1388 | { | |
1389 | struct btrfs_block_group_cache *block_group = ctl->private; | |
1390 | ||
1391 | /* | |
1392 | * If we are below the extents threshold then we can add this as an | |
1393 | * extent, and don't have to deal with the bitmap | |
1394 | */ | |
1395 | if (ctl->free_extents < ctl->extents_thresh) { | |
1396 | /* | |
1397 | * If this block group has some small extents we don't want to | |
1398 | * use up all of our free slots in the cache with them, we want | |
1399 | * to reserve them to larger extents, however if we have plent | |
1400 | * of cache left then go ahead an dadd them, no sense in adding | |
1401 | * the overhead of a bitmap if we don't have to. | |
1402 | */ | |
1403 | if (info->bytes <= block_group->sectorsize * 4) { | |
1404 | if (ctl->free_extents * 2 <= ctl->extents_thresh) | |
1405 | return false; | |
1406 | } else { | |
1407 | return false; | |
1408 | } | |
1409 | } | |
1410 | ||
1411 | /* | |
1412 | * some block groups are so tiny they can't be enveloped by a bitmap, so | |
1413 | * don't even bother to create a bitmap for this | |
1414 | */ | |
1415 | if (BITS_PER_BITMAP * block_group->sectorsize > | |
1416 | block_group->key.offset) | |
1417 | return false; | |
1418 | ||
1419 | return true; | |
1420 | } | |
1421 | ||
1422 | static struct btrfs_free_space_op free_space_op = { | |
1423 | .recalc_thresholds = recalculate_thresholds, | |
1424 | .use_bitmap = use_bitmap, | |
1425 | }; | |
1426 | ||
1427 | static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl, | |
1428 | struct btrfs_free_space *info) | |
1429 | { | |
1430 | struct btrfs_free_space *bitmap_info; | |
1431 | struct btrfs_block_group_cache *block_group = NULL; | |
1432 | int added = 0; | |
1433 | u64 bytes, offset, bytes_added; | |
1434 | int ret; | |
1435 | ||
1436 | bytes = info->bytes; | |
1437 | offset = info->offset; | |
1438 | ||
1439 | if (!ctl->op->use_bitmap(ctl, info)) | |
1440 | return 0; | |
1441 | ||
1442 | if (ctl->op == &free_space_op) | |
1443 | block_group = ctl->private; | |
1444 | again: | |
1445 | /* | |
1446 | * Since we link bitmaps right into the cluster we need to see if we | |
1447 | * have a cluster here, and if so and it has our bitmap we need to add | |
1448 | * the free space to that bitmap. | |
1449 | */ | |
1450 | if (block_group && !list_empty(&block_group->cluster_list)) { | |
1451 | struct btrfs_free_cluster *cluster; | |
1452 | struct rb_node *node; | |
1453 | struct btrfs_free_space *entry; | |
1454 | ||
1455 | cluster = list_entry(block_group->cluster_list.next, | |
1456 | struct btrfs_free_cluster, | |
1457 | block_group_list); | |
1458 | spin_lock(&cluster->lock); | |
1459 | node = rb_first(&cluster->root); | |
1460 | if (!node) { | |
1461 | spin_unlock(&cluster->lock); | |
1462 | goto no_cluster_bitmap; | |
1463 | } | |
1464 | ||
1465 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1466 | if (!entry->bitmap) { | |
1467 | spin_unlock(&cluster->lock); | |
1468 | goto no_cluster_bitmap; | |
1469 | } | |
1470 | ||
1471 | if (entry->offset == offset_to_bitmap(ctl, offset)) { | |
1472 | bytes_added = add_bytes_to_bitmap(ctl, entry, | |
1473 | offset, bytes); | |
1474 | bytes -= bytes_added; | |
1475 | offset += bytes_added; | |
1476 | } | |
1477 | spin_unlock(&cluster->lock); | |
1478 | if (!bytes) { | |
1479 | ret = 1; | |
1480 | goto out; | |
1481 | } | |
1482 | } | |
1483 | ||
1484 | no_cluster_bitmap: | |
1485 | bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), | |
1486 | 1, 0); | |
1487 | if (!bitmap_info) { | |
1488 | BUG_ON(added); | |
1489 | goto new_bitmap; | |
1490 | } | |
1491 | ||
1492 | bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes); | |
1493 | bytes -= bytes_added; | |
1494 | offset += bytes_added; | |
1495 | added = 0; | |
1496 | ||
1497 | if (!bytes) { | |
1498 | ret = 1; | |
1499 | goto out; | |
1500 | } else | |
1501 | goto again; | |
1502 | ||
1503 | new_bitmap: | |
1504 | if (info && info->bitmap) { | |
1505 | add_new_bitmap(ctl, info, offset); | |
1506 | added = 1; | |
1507 | info = NULL; | |
1508 | goto again; | |
1509 | } else { | |
1510 | spin_unlock(&ctl->tree_lock); | |
1511 | ||
1512 | /* no pre-allocated info, allocate a new one */ | |
1513 | if (!info) { | |
1514 | info = kmem_cache_zalloc(btrfs_free_space_cachep, | |
1515 | GFP_NOFS); | |
1516 | if (!info) { | |
1517 | spin_lock(&ctl->tree_lock); | |
1518 | ret = -ENOMEM; | |
1519 | goto out; | |
1520 | } | |
1521 | } | |
1522 | ||
1523 | /* allocate the bitmap */ | |
1524 | info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); | |
1525 | spin_lock(&ctl->tree_lock); | |
1526 | if (!info->bitmap) { | |
1527 | ret = -ENOMEM; | |
1528 | goto out; | |
1529 | } | |
1530 | goto again; | |
1531 | } | |
1532 | ||
1533 | out: | |
1534 | if (info) { | |
1535 | if (info->bitmap) | |
1536 | kfree(info->bitmap); | |
1537 | kmem_cache_free(btrfs_free_space_cachep, info); | |
1538 | } | |
1539 | ||
1540 | return ret; | |
1541 | } | |
1542 | ||
1543 | static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl, | |
1544 | struct btrfs_free_space *info, bool update_stat) | |
1545 | { | |
1546 | struct btrfs_free_space *left_info; | |
1547 | struct btrfs_free_space *right_info; | |
1548 | bool merged = false; | |
1549 | u64 offset = info->offset; | |
1550 | u64 bytes = info->bytes; | |
1551 | ||
1552 | /* | |
1553 | * first we want to see if there is free space adjacent to the range we | |
1554 | * are adding, if there is remove that struct and add a new one to | |
1555 | * cover the entire range | |
1556 | */ | |
1557 | right_info = tree_search_offset(ctl, offset + bytes, 0, 0); | |
1558 | if (right_info && rb_prev(&right_info->offset_index)) | |
1559 | left_info = rb_entry(rb_prev(&right_info->offset_index), | |
1560 | struct btrfs_free_space, offset_index); | |
1561 | else | |
1562 | left_info = tree_search_offset(ctl, offset - 1, 0, 0); | |
1563 | ||
1564 | if (right_info && !right_info->bitmap) { | |
1565 | if (update_stat) | |
1566 | unlink_free_space(ctl, right_info); | |
1567 | else | |
1568 | __unlink_free_space(ctl, right_info); | |
1569 | info->bytes += right_info->bytes; | |
1570 | kmem_cache_free(btrfs_free_space_cachep, right_info); | |
1571 | merged = true; | |
1572 | } | |
1573 | ||
1574 | if (left_info && !left_info->bitmap && | |
1575 | left_info->offset + left_info->bytes == offset) { | |
1576 | if (update_stat) | |
1577 | unlink_free_space(ctl, left_info); | |
1578 | else | |
1579 | __unlink_free_space(ctl, left_info); | |
1580 | info->offset = left_info->offset; | |
1581 | info->bytes += left_info->bytes; | |
1582 | kmem_cache_free(btrfs_free_space_cachep, left_info); | |
1583 | merged = true; | |
1584 | } | |
1585 | ||
1586 | return merged; | |
1587 | } | |
1588 | ||
1589 | int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl, | |
1590 | u64 offset, u64 bytes) | |
1591 | { | |
1592 | struct btrfs_free_space *info; | |
1593 | int ret = 0; | |
1594 | ||
1595 | info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS); | |
1596 | if (!info) | |
1597 | return -ENOMEM; | |
1598 | ||
1599 | info->offset = offset; | |
1600 | info->bytes = bytes; | |
1601 | ||
1602 | spin_lock(&ctl->tree_lock); | |
1603 | ||
1604 | if (try_merge_free_space(ctl, info, true)) | |
1605 | goto link; | |
1606 | ||
1607 | /* | |
1608 | * There was no extent directly to the left or right of this new | |
1609 | * extent then we know we're going to have to allocate a new extent, so | |
1610 | * before we do that see if we need to drop this into a bitmap | |
1611 | */ | |
1612 | ret = insert_into_bitmap(ctl, info); | |
1613 | if (ret < 0) { | |
1614 | goto out; | |
1615 | } else if (ret) { | |
1616 | ret = 0; | |
1617 | goto out; | |
1618 | } | |
1619 | link: | |
1620 | ret = link_free_space(ctl, info); | |
1621 | if (ret) | |
1622 | kmem_cache_free(btrfs_free_space_cachep, info); | |
1623 | out: | |
1624 | spin_unlock(&ctl->tree_lock); | |
1625 | ||
1626 | if (ret) { | |
1627 | printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret); | |
1628 | BUG_ON(ret == -EEXIST); | |
1629 | } | |
1630 | ||
1631 | return ret; | |
1632 | } | |
1633 | ||
1634 | int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group, | |
1635 | u64 offset, u64 bytes) | |
1636 | { | |
1637 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
1638 | struct btrfs_free_space *info; | |
1639 | struct btrfs_free_space *next_info = NULL; | |
1640 | int ret = 0; | |
1641 | ||
1642 | spin_lock(&ctl->tree_lock); | |
1643 | ||
1644 | again: | |
1645 | info = tree_search_offset(ctl, offset, 0, 0); | |
1646 | if (!info) { | |
1647 | /* | |
1648 | * oops didn't find an extent that matched the space we wanted | |
1649 | * to remove, look for a bitmap instead | |
1650 | */ | |
1651 | info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), | |
1652 | 1, 0); | |
1653 | if (!info) { | |
1654 | WARN_ON(1); | |
1655 | goto out_lock; | |
1656 | } | |
1657 | } | |
1658 | ||
1659 | if (info->bytes < bytes && rb_next(&info->offset_index)) { | |
1660 | u64 end; | |
1661 | next_info = rb_entry(rb_next(&info->offset_index), | |
1662 | struct btrfs_free_space, | |
1663 | offset_index); | |
1664 | ||
1665 | if (next_info->bitmap) | |
1666 | end = next_info->offset + | |
1667 | BITS_PER_BITMAP * ctl->unit - 1; | |
1668 | else | |
1669 | end = next_info->offset + next_info->bytes; | |
1670 | ||
1671 | if (next_info->bytes < bytes || | |
1672 | next_info->offset > offset || offset > end) { | |
1673 | printk(KERN_CRIT "Found free space at %llu, size %llu," | |
1674 | " trying to use %llu\n", | |
1675 | (unsigned long long)info->offset, | |
1676 | (unsigned long long)info->bytes, | |
1677 | (unsigned long long)bytes); | |
1678 | WARN_ON(1); | |
1679 | ret = -EINVAL; | |
1680 | goto out_lock; | |
1681 | } | |
1682 | ||
1683 | info = next_info; | |
1684 | } | |
1685 | ||
1686 | if (info->bytes == bytes) { | |
1687 | unlink_free_space(ctl, info); | |
1688 | if (info->bitmap) { | |
1689 | kfree(info->bitmap); | |
1690 | ctl->total_bitmaps--; | |
1691 | } | |
1692 | kmem_cache_free(btrfs_free_space_cachep, info); | |
1693 | goto out_lock; | |
1694 | } | |
1695 | ||
1696 | if (!info->bitmap && info->offset == offset) { | |
1697 | unlink_free_space(ctl, info); | |
1698 | info->offset += bytes; | |
1699 | info->bytes -= bytes; | |
1700 | link_free_space(ctl, info); | |
1701 | goto out_lock; | |
1702 | } | |
1703 | ||
1704 | if (!info->bitmap && info->offset <= offset && | |
1705 | info->offset + info->bytes >= offset + bytes) { | |
1706 | u64 old_start = info->offset; | |
1707 | /* | |
1708 | * we're freeing space in the middle of the info, | |
1709 | * this can happen during tree log replay | |
1710 | * | |
1711 | * first unlink the old info and then | |
1712 | * insert it again after the hole we're creating | |
1713 | */ | |
1714 | unlink_free_space(ctl, info); | |
1715 | if (offset + bytes < info->offset + info->bytes) { | |
1716 | u64 old_end = info->offset + info->bytes; | |
1717 | ||
1718 | info->offset = offset + bytes; | |
1719 | info->bytes = old_end - info->offset; | |
1720 | ret = link_free_space(ctl, info); | |
1721 | WARN_ON(ret); | |
1722 | if (ret) | |
1723 | goto out_lock; | |
1724 | } else { | |
1725 | /* the hole we're creating ends at the end | |
1726 | * of the info struct, just free the info | |
1727 | */ | |
1728 | kmem_cache_free(btrfs_free_space_cachep, info); | |
1729 | } | |
1730 | spin_unlock(&ctl->tree_lock); | |
1731 | ||
1732 | /* step two, insert a new info struct to cover | |
1733 | * anything before the hole | |
1734 | */ | |
1735 | ret = btrfs_add_free_space(block_group, old_start, | |
1736 | offset - old_start); | |
1737 | WARN_ON(ret); | |
1738 | goto out; | |
1739 | } | |
1740 | ||
1741 | ret = remove_from_bitmap(ctl, info, &offset, &bytes); | |
1742 | if (ret == -EAGAIN) | |
1743 | goto again; | |
1744 | BUG_ON(ret); | |
1745 | out_lock: | |
1746 | spin_unlock(&ctl->tree_lock); | |
1747 | out: | |
1748 | return ret; | |
1749 | } | |
1750 | ||
1751 | void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group, | |
1752 | u64 bytes) | |
1753 | { | |
1754 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
1755 | struct btrfs_free_space *info; | |
1756 | struct rb_node *n; | |
1757 | int count = 0; | |
1758 | ||
1759 | for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) { | |
1760 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
1761 | if (info->bytes >= bytes) | |
1762 | count++; | |
1763 | printk(KERN_CRIT "entry offset %llu, bytes %llu, bitmap %s\n", | |
1764 | (unsigned long long)info->offset, | |
1765 | (unsigned long long)info->bytes, | |
1766 | (info->bitmap) ? "yes" : "no"); | |
1767 | } | |
1768 | printk(KERN_INFO "block group has cluster?: %s\n", | |
1769 | list_empty(&block_group->cluster_list) ? "no" : "yes"); | |
1770 | printk(KERN_INFO "%d blocks of free space at or bigger than bytes is" | |
1771 | "\n", count); | |
1772 | } | |
1773 | ||
1774 | void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group) | |
1775 | { | |
1776 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
1777 | ||
1778 | spin_lock_init(&ctl->tree_lock); | |
1779 | ctl->unit = block_group->sectorsize; | |
1780 | ctl->start = block_group->key.objectid; | |
1781 | ctl->private = block_group; | |
1782 | ctl->op = &free_space_op; | |
1783 | ||
1784 | /* | |
1785 | * we only want to have 32k of ram per block group for keeping | |
1786 | * track of free space, and if we pass 1/2 of that we want to | |
1787 | * start converting things over to using bitmaps | |
1788 | */ | |
1789 | ctl->extents_thresh = ((1024 * 32) / 2) / | |
1790 | sizeof(struct btrfs_free_space); | |
1791 | } | |
1792 | ||
1793 | /* | |
1794 | * for a given cluster, put all of its extents back into the free | |
1795 | * space cache. If the block group passed doesn't match the block group | |
1796 | * pointed to by the cluster, someone else raced in and freed the | |
1797 | * cluster already. In that case, we just return without changing anything | |
1798 | */ | |
1799 | static int | |
1800 | __btrfs_return_cluster_to_free_space( | |
1801 | struct btrfs_block_group_cache *block_group, | |
1802 | struct btrfs_free_cluster *cluster) | |
1803 | { | |
1804 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
1805 | struct btrfs_free_space *entry; | |
1806 | struct rb_node *node; | |
1807 | ||
1808 | spin_lock(&cluster->lock); | |
1809 | if (cluster->block_group != block_group) | |
1810 | goto out; | |
1811 | ||
1812 | cluster->block_group = NULL; | |
1813 | cluster->window_start = 0; | |
1814 | list_del_init(&cluster->block_group_list); | |
1815 | ||
1816 | node = rb_first(&cluster->root); | |
1817 | while (node) { | |
1818 | bool bitmap; | |
1819 | ||
1820 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1821 | node = rb_next(&entry->offset_index); | |
1822 | rb_erase(&entry->offset_index, &cluster->root); | |
1823 | ||
1824 | bitmap = (entry->bitmap != NULL); | |
1825 | if (!bitmap) | |
1826 | try_merge_free_space(ctl, entry, false); | |
1827 | tree_insert_offset(&ctl->free_space_offset, | |
1828 | entry->offset, &entry->offset_index, bitmap); | |
1829 | } | |
1830 | cluster->root = RB_ROOT; | |
1831 | ||
1832 | out: | |
1833 | spin_unlock(&cluster->lock); | |
1834 | btrfs_put_block_group(block_group); | |
1835 | return 0; | |
1836 | } | |
1837 | ||
1838 | void __btrfs_remove_free_space_cache_locked(struct btrfs_free_space_ctl *ctl) | |
1839 | { | |
1840 | struct btrfs_free_space *info; | |
1841 | struct rb_node *node; | |
1842 | ||
1843 | while ((node = rb_last(&ctl->free_space_offset)) != NULL) { | |
1844 | info = rb_entry(node, struct btrfs_free_space, offset_index); | |
1845 | if (!info->bitmap) { | |
1846 | unlink_free_space(ctl, info); | |
1847 | kmem_cache_free(btrfs_free_space_cachep, info); | |
1848 | } else { | |
1849 | free_bitmap(ctl, info); | |
1850 | } | |
1851 | if (need_resched()) { | |
1852 | spin_unlock(&ctl->tree_lock); | |
1853 | cond_resched(); | |
1854 | spin_lock(&ctl->tree_lock); | |
1855 | } | |
1856 | } | |
1857 | } | |
1858 | ||
1859 | void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl) | |
1860 | { | |
1861 | spin_lock(&ctl->tree_lock); | |
1862 | __btrfs_remove_free_space_cache_locked(ctl); | |
1863 | spin_unlock(&ctl->tree_lock); | |
1864 | } | |
1865 | ||
1866 | void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group) | |
1867 | { | |
1868 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
1869 | struct btrfs_free_cluster *cluster; | |
1870 | struct list_head *head; | |
1871 | ||
1872 | spin_lock(&ctl->tree_lock); | |
1873 | while ((head = block_group->cluster_list.next) != | |
1874 | &block_group->cluster_list) { | |
1875 | cluster = list_entry(head, struct btrfs_free_cluster, | |
1876 | block_group_list); | |
1877 | ||
1878 | WARN_ON(cluster->block_group != block_group); | |
1879 | __btrfs_return_cluster_to_free_space(block_group, cluster); | |
1880 | if (need_resched()) { | |
1881 | spin_unlock(&ctl->tree_lock); | |
1882 | cond_resched(); | |
1883 | spin_lock(&ctl->tree_lock); | |
1884 | } | |
1885 | } | |
1886 | __btrfs_remove_free_space_cache_locked(ctl); | |
1887 | spin_unlock(&ctl->tree_lock); | |
1888 | ||
1889 | } | |
1890 | ||
1891 | u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group, | |
1892 | u64 offset, u64 bytes, u64 empty_size) | |
1893 | { | |
1894 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
1895 | struct btrfs_free_space *entry = NULL; | |
1896 | u64 bytes_search = bytes + empty_size; | |
1897 | u64 ret = 0; | |
1898 | ||
1899 | spin_lock(&ctl->tree_lock); | |
1900 | entry = find_free_space(ctl, &offset, &bytes_search); | |
1901 | if (!entry) | |
1902 | goto out; | |
1903 | ||
1904 | ret = offset; | |
1905 | if (entry->bitmap) { | |
1906 | bitmap_clear_bits(ctl, entry, offset, bytes); | |
1907 | if (!entry->bytes) | |
1908 | free_bitmap(ctl, entry); | |
1909 | } else { | |
1910 | unlink_free_space(ctl, entry); | |
1911 | entry->offset += bytes; | |
1912 | entry->bytes -= bytes; | |
1913 | if (!entry->bytes) | |
1914 | kmem_cache_free(btrfs_free_space_cachep, entry); | |
1915 | else | |
1916 | link_free_space(ctl, entry); | |
1917 | } | |
1918 | ||
1919 | out: | |
1920 | spin_unlock(&ctl->tree_lock); | |
1921 | ||
1922 | return ret; | |
1923 | } | |
1924 | ||
1925 | /* | |
1926 | * given a cluster, put all of its extents back into the free space | |
1927 | * cache. If a block group is passed, this function will only free | |
1928 | * a cluster that belongs to the passed block group. | |
1929 | * | |
1930 | * Otherwise, it'll get a reference on the block group pointed to by the | |
1931 | * cluster and remove the cluster from it. | |
1932 | */ | |
1933 | int btrfs_return_cluster_to_free_space( | |
1934 | struct btrfs_block_group_cache *block_group, | |
1935 | struct btrfs_free_cluster *cluster) | |
1936 | { | |
1937 | struct btrfs_free_space_ctl *ctl; | |
1938 | int ret; | |
1939 | ||
1940 | /* first, get a safe pointer to the block group */ | |
1941 | spin_lock(&cluster->lock); | |
1942 | if (!block_group) { | |
1943 | block_group = cluster->block_group; | |
1944 | if (!block_group) { | |
1945 | spin_unlock(&cluster->lock); | |
1946 | return 0; | |
1947 | } | |
1948 | } else if (cluster->block_group != block_group) { | |
1949 | /* someone else has already freed it don't redo their work */ | |
1950 | spin_unlock(&cluster->lock); | |
1951 | return 0; | |
1952 | } | |
1953 | atomic_inc(&block_group->count); | |
1954 | spin_unlock(&cluster->lock); | |
1955 | ||
1956 | ctl = block_group->free_space_ctl; | |
1957 | ||
1958 | /* now return any extents the cluster had on it */ | |
1959 | spin_lock(&ctl->tree_lock); | |
1960 | ret = __btrfs_return_cluster_to_free_space(block_group, cluster); | |
1961 | spin_unlock(&ctl->tree_lock); | |
1962 | ||
1963 | /* finally drop our ref */ | |
1964 | btrfs_put_block_group(block_group); | |
1965 | return ret; | |
1966 | } | |
1967 | ||
1968 | static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group, | |
1969 | struct btrfs_free_cluster *cluster, | |
1970 | struct btrfs_free_space *entry, | |
1971 | u64 bytes, u64 min_start) | |
1972 | { | |
1973 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
1974 | int err; | |
1975 | u64 search_start = cluster->window_start; | |
1976 | u64 search_bytes = bytes; | |
1977 | u64 ret = 0; | |
1978 | ||
1979 | search_start = min_start; | |
1980 | search_bytes = bytes; | |
1981 | ||
1982 | err = search_bitmap(ctl, entry, &search_start, &search_bytes); | |
1983 | if (err) | |
1984 | return 0; | |
1985 | ||
1986 | ret = search_start; | |
1987 | bitmap_clear_bits(ctl, entry, ret, bytes); | |
1988 | ||
1989 | return ret; | |
1990 | } | |
1991 | ||
1992 | /* | |
1993 | * given a cluster, try to allocate 'bytes' from it, returns 0 | |
1994 | * if it couldn't find anything suitably large, or a logical disk offset | |
1995 | * if things worked out | |
1996 | */ | |
1997 | u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group, | |
1998 | struct btrfs_free_cluster *cluster, u64 bytes, | |
1999 | u64 min_start) | |
2000 | { | |
2001 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
2002 | struct btrfs_free_space *entry = NULL; | |
2003 | struct rb_node *node; | |
2004 | u64 ret = 0; | |
2005 | ||
2006 | spin_lock(&cluster->lock); | |
2007 | if (bytes > cluster->max_size) | |
2008 | goto out; | |
2009 | ||
2010 | if (cluster->block_group != block_group) | |
2011 | goto out; | |
2012 | ||
2013 | node = rb_first(&cluster->root); | |
2014 | if (!node) | |
2015 | goto out; | |
2016 | ||
2017 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
2018 | while(1) { | |
2019 | if (entry->bytes < bytes || | |
2020 | (!entry->bitmap && entry->offset < min_start)) { | |
2021 | node = rb_next(&entry->offset_index); | |
2022 | if (!node) | |
2023 | break; | |
2024 | entry = rb_entry(node, struct btrfs_free_space, | |
2025 | offset_index); | |
2026 | continue; | |
2027 | } | |
2028 | ||
2029 | if (entry->bitmap) { | |
2030 | ret = btrfs_alloc_from_bitmap(block_group, | |
2031 | cluster, entry, bytes, | |
2032 | min_start); | |
2033 | if (ret == 0) { | |
2034 | node = rb_next(&entry->offset_index); | |
2035 | if (!node) | |
2036 | break; | |
2037 | entry = rb_entry(node, struct btrfs_free_space, | |
2038 | offset_index); | |
2039 | continue; | |
2040 | } | |
2041 | } else { | |
2042 | ||
2043 | ret = entry->offset; | |
2044 | ||
2045 | entry->offset += bytes; | |
2046 | entry->bytes -= bytes; | |
2047 | } | |
2048 | ||
2049 | if (entry->bytes == 0) | |
2050 | rb_erase(&entry->offset_index, &cluster->root); | |
2051 | break; | |
2052 | } | |
2053 | out: | |
2054 | spin_unlock(&cluster->lock); | |
2055 | ||
2056 | if (!ret) | |
2057 | return 0; | |
2058 | ||
2059 | spin_lock(&ctl->tree_lock); | |
2060 | ||
2061 | ctl->free_space -= bytes; | |
2062 | if (entry->bytes == 0) { | |
2063 | ctl->free_extents--; | |
2064 | if (entry->bitmap) { | |
2065 | kfree(entry->bitmap); | |
2066 | ctl->total_bitmaps--; | |
2067 | ctl->op->recalc_thresholds(ctl); | |
2068 | } | |
2069 | kmem_cache_free(btrfs_free_space_cachep, entry); | |
2070 | } | |
2071 | ||
2072 | spin_unlock(&ctl->tree_lock); | |
2073 | ||
2074 | return ret; | |
2075 | } | |
2076 | ||
2077 | static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group, | |
2078 | struct btrfs_free_space *entry, | |
2079 | struct btrfs_free_cluster *cluster, | |
2080 | u64 offset, u64 bytes, u64 min_bytes) | |
2081 | { | |
2082 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
2083 | unsigned long next_zero; | |
2084 | unsigned long i; | |
2085 | unsigned long search_bits; | |
2086 | unsigned long total_bits; | |
2087 | unsigned long found_bits; | |
2088 | unsigned long start = 0; | |
2089 | unsigned long total_found = 0; | |
2090 | int ret; | |
2091 | bool found = false; | |
2092 | ||
2093 | i = offset_to_bit(entry->offset, block_group->sectorsize, | |
2094 | max_t(u64, offset, entry->offset)); | |
2095 | search_bits = bytes_to_bits(bytes, block_group->sectorsize); | |
2096 | total_bits = bytes_to_bits(min_bytes, block_group->sectorsize); | |
2097 | ||
2098 | again: | |
2099 | found_bits = 0; | |
2100 | for (i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i); | |
2101 | i < BITS_PER_BITMAP; | |
2102 | i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) { | |
2103 | next_zero = find_next_zero_bit(entry->bitmap, | |
2104 | BITS_PER_BITMAP, i); | |
2105 | if (next_zero - i >= search_bits) { | |
2106 | found_bits = next_zero - i; | |
2107 | break; | |
2108 | } | |
2109 | i = next_zero; | |
2110 | } | |
2111 | ||
2112 | if (!found_bits) | |
2113 | return -ENOSPC; | |
2114 | ||
2115 | if (!found) { | |
2116 | start = i; | |
2117 | found = true; | |
2118 | } | |
2119 | ||
2120 | total_found += found_bits; | |
2121 | ||
2122 | if (cluster->max_size < found_bits * block_group->sectorsize) | |
2123 | cluster->max_size = found_bits * block_group->sectorsize; | |
2124 | ||
2125 | if (total_found < total_bits) { | |
2126 | i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, next_zero); | |
2127 | if (i - start > total_bits * 2) { | |
2128 | total_found = 0; | |
2129 | cluster->max_size = 0; | |
2130 | found = false; | |
2131 | } | |
2132 | goto again; | |
2133 | } | |
2134 | ||
2135 | cluster->window_start = start * block_group->sectorsize + | |
2136 | entry->offset; | |
2137 | rb_erase(&entry->offset_index, &ctl->free_space_offset); | |
2138 | ret = tree_insert_offset(&cluster->root, entry->offset, | |
2139 | &entry->offset_index, 1); | |
2140 | BUG_ON(ret); | |
2141 | ||
2142 | return 0; | |
2143 | } | |
2144 | ||
2145 | /* | |
2146 | * This searches the block group for just extents to fill the cluster with. | |
2147 | */ | |
2148 | static noinline int | |
2149 | setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group, | |
2150 | struct btrfs_free_cluster *cluster, | |
2151 | struct list_head *bitmaps, u64 offset, u64 bytes, | |
2152 | u64 min_bytes) | |
2153 | { | |
2154 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
2155 | struct btrfs_free_space *first = NULL; | |
2156 | struct btrfs_free_space *entry = NULL; | |
2157 | struct btrfs_free_space *prev = NULL; | |
2158 | struct btrfs_free_space *last; | |
2159 | struct rb_node *node; | |
2160 | u64 window_start; | |
2161 | u64 window_free; | |
2162 | u64 max_extent; | |
2163 | u64 max_gap = 128 * 1024; | |
2164 | ||
2165 | entry = tree_search_offset(ctl, offset, 0, 1); | |
2166 | if (!entry) | |
2167 | return -ENOSPC; | |
2168 | ||
2169 | /* | |
2170 | * We don't want bitmaps, so just move along until we find a normal | |
2171 | * extent entry. | |
2172 | */ | |
2173 | while (entry->bitmap) { | |
2174 | if (list_empty(&entry->list)) | |
2175 | list_add_tail(&entry->list, bitmaps); | |
2176 | node = rb_next(&entry->offset_index); | |
2177 | if (!node) | |
2178 | return -ENOSPC; | |
2179 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
2180 | } | |
2181 | ||
2182 | window_start = entry->offset; | |
2183 | window_free = entry->bytes; | |
2184 | max_extent = entry->bytes; | |
2185 | first = entry; | |
2186 | last = entry; | |
2187 | prev = entry; | |
2188 | ||
2189 | while (window_free <= min_bytes) { | |
2190 | node = rb_next(&entry->offset_index); | |
2191 | if (!node) | |
2192 | return -ENOSPC; | |
2193 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
2194 | ||
2195 | if (entry->bitmap) { | |
2196 | if (list_empty(&entry->list)) | |
2197 | list_add_tail(&entry->list, bitmaps); | |
2198 | continue; | |
2199 | } | |
2200 | ||
2201 | /* | |
2202 | * we haven't filled the empty size and the window is | |
2203 | * very large. reset and try again | |
2204 | */ | |
2205 | if (entry->offset - (prev->offset + prev->bytes) > max_gap || | |
2206 | entry->offset - window_start > (min_bytes * 2)) { | |
2207 | first = entry; | |
2208 | window_start = entry->offset; | |
2209 | window_free = entry->bytes; | |
2210 | last = entry; | |
2211 | max_extent = entry->bytes; | |
2212 | } else { | |
2213 | last = entry; | |
2214 | window_free += entry->bytes; | |
2215 | if (entry->bytes > max_extent) | |
2216 | max_extent = entry->bytes; | |
2217 | } | |
2218 | prev = entry; | |
2219 | } | |
2220 | ||
2221 | cluster->window_start = first->offset; | |
2222 | ||
2223 | node = &first->offset_index; | |
2224 | ||
2225 | /* | |
2226 | * now we've found our entries, pull them out of the free space | |
2227 | * cache and put them into the cluster rbtree | |
2228 | */ | |
2229 | do { | |
2230 | int ret; | |
2231 | ||
2232 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
2233 | node = rb_next(&entry->offset_index); | |
2234 | if (entry->bitmap) | |
2235 | continue; | |
2236 | ||
2237 | rb_erase(&entry->offset_index, &ctl->free_space_offset); | |
2238 | ret = tree_insert_offset(&cluster->root, entry->offset, | |
2239 | &entry->offset_index, 0); | |
2240 | BUG_ON(ret); | |
2241 | } while (node && entry != last); | |
2242 | ||
2243 | cluster->max_size = max_extent; | |
2244 | ||
2245 | return 0; | |
2246 | } | |
2247 | ||
2248 | /* | |
2249 | * This specifically looks for bitmaps that may work in the cluster, we assume | |
2250 | * that we have already failed to find extents that will work. | |
2251 | */ | |
2252 | static noinline int | |
2253 | setup_cluster_bitmap(struct btrfs_block_group_cache *block_group, | |
2254 | struct btrfs_free_cluster *cluster, | |
2255 | struct list_head *bitmaps, u64 offset, u64 bytes, | |
2256 | u64 min_bytes) | |
2257 | { | |
2258 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
2259 | struct btrfs_free_space *entry; | |
2260 | struct rb_node *node; | |
2261 | int ret = -ENOSPC; | |
2262 | ||
2263 | if (ctl->total_bitmaps == 0) | |
2264 | return -ENOSPC; | |
2265 | ||
2266 | /* | |
2267 | * First check our cached list of bitmaps and see if there is an entry | |
2268 | * here that will work. | |
2269 | */ | |
2270 | list_for_each_entry(entry, bitmaps, list) { | |
2271 | if (entry->bytes < min_bytes) | |
2272 | continue; | |
2273 | ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset, | |
2274 | bytes, min_bytes); | |
2275 | if (!ret) | |
2276 | return 0; | |
2277 | } | |
2278 | ||
2279 | /* | |
2280 | * If we do have entries on our list and we are here then we didn't find | |
2281 | * anything, so go ahead and get the next entry after the last entry in | |
2282 | * this list and start the search from there. | |
2283 | */ | |
2284 | if (!list_empty(bitmaps)) { | |
2285 | entry = list_entry(bitmaps->prev, struct btrfs_free_space, | |
2286 | list); | |
2287 | node = rb_next(&entry->offset_index); | |
2288 | if (!node) | |
2289 | return -ENOSPC; | |
2290 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
2291 | goto search; | |
2292 | } | |
2293 | ||
2294 | entry = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), 0, 1); | |
2295 | if (!entry) | |
2296 | return -ENOSPC; | |
2297 | ||
2298 | search: | |
2299 | node = &entry->offset_index; | |
2300 | do { | |
2301 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
2302 | node = rb_next(&entry->offset_index); | |
2303 | if (!entry->bitmap) | |
2304 | continue; | |
2305 | if (entry->bytes < min_bytes) | |
2306 | continue; | |
2307 | ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset, | |
2308 | bytes, min_bytes); | |
2309 | } while (ret && node); | |
2310 | ||
2311 | return ret; | |
2312 | } | |
2313 | ||
2314 | /* | |
2315 | * here we try to find a cluster of blocks in a block group. The goal | |
2316 | * is to find at least bytes free and up to empty_size + bytes free. | |
2317 | * We might not find them all in one contiguous area. | |
2318 | * | |
2319 | * returns zero and sets up cluster if things worked out, otherwise | |
2320 | * it returns -enospc | |
2321 | */ | |
2322 | int btrfs_find_space_cluster(struct btrfs_trans_handle *trans, | |
2323 | struct btrfs_root *root, | |
2324 | struct btrfs_block_group_cache *block_group, | |
2325 | struct btrfs_free_cluster *cluster, | |
2326 | u64 offset, u64 bytes, u64 empty_size) | |
2327 | { | |
2328 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
2329 | struct list_head bitmaps; | |
2330 | struct btrfs_free_space *entry, *tmp; | |
2331 | u64 min_bytes; | |
2332 | int ret; | |
2333 | ||
2334 | /* for metadata, allow allocates with more holes */ | |
2335 | if (btrfs_test_opt(root, SSD_SPREAD)) { | |
2336 | min_bytes = bytes + empty_size; | |
2337 | } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) { | |
2338 | /* | |
2339 | * we want to do larger allocations when we are | |
2340 | * flushing out the delayed refs, it helps prevent | |
2341 | * making more work as we go along. | |
2342 | */ | |
2343 | if (trans->transaction->delayed_refs.flushing) | |
2344 | min_bytes = max(bytes, (bytes + empty_size) >> 1); | |
2345 | else | |
2346 | min_bytes = max(bytes, (bytes + empty_size) >> 4); | |
2347 | } else | |
2348 | min_bytes = max(bytes, (bytes + empty_size) >> 2); | |
2349 | ||
2350 | spin_lock(&ctl->tree_lock); | |
2351 | ||
2352 | /* | |
2353 | * If we know we don't have enough space to make a cluster don't even | |
2354 | * bother doing all the work to try and find one. | |
2355 | */ | |
2356 | if (ctl->free_space < min_bytes) { | |
2357 | spin_unlock(&ctl->tree_lock); | |
2358 | return -ENOSPC; | |
2359 | } | |
2360 | ||
2361 | spin_lock(&cluster->lock); | |
2362 | ||
2363 | /* someone already found a cluster, hooray */ | |
2364 | if (cluster->block_group) { | |
2365 | ret = 0; | |
2366 | goto out; | |
2367 | } | |
2368 | ||
2369 | INIT_LIST_HEAD(&bitmaps); | |
2370 | ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset, | |
2371 | bytes, min_bytes); | |
2372 | if (ret) | |
2373 | ret = setup_cluster_bitmap(block_group, cluster, &bitmaps, | |
2374 | offset, bytes, min_bytes); | |
2375 | ||
2376 | /* Clear our temporary list */ | |
2377 | list_for_each_entry_safe(entry, tmp, &bitmaps, list) | |
2378 | list_del_init(&entry->list); | |
2379 | ||
2380 | if (!ret) { | |
2381 | atomic_inc(&block_group->count); | |
2382 | list_add_tail(&cluster->block_group_list, | |
2383 | &block_group->cluster_list); | |
2384 | cluster->block_group = block_group; | |
2385 | } | |
2386 | out: | |
2387 | spin_unlock(&cluster->lock); | |
2388 | spin_unlock(&ctl->tree_lock); | |
2389 | ||
2390 | return ret; | |
2391 | } | |
2392 | ||
2393 | /* | |
2394 | * simple code to zero out a cluster | |
2395 | */ | |
2396 | void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster) | |
2397 | { | |
2398 | spin_lock_init(&cluster->lock); | |
2399 | spin_lock_init(&cluster->refill_lock); | |
2400 | cluster->root = RB_ROOT; | |
2401 | cluster->max_size = 0; | |
2402 | INIT_LIST_HEAD(&cluster->block_group_list); | |
2403 | cluster->block_group = NULL; | |
2404 | } | |
2405 | ||
2406 | int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, | |
2407 | u64 *trimmed, u64 start, u64 end, u64 minlen) | |
2408 | { | |
2409 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; | |
2410 | struct btrfs_free_space *entry = NULL; | |
2411 | struct btrfs_fs_info *fs_info = block_group->fs_info; | |
2412 | u64 bytes = 0; | |
2413 | u64 actually_trimmed; | |
2414 | int ret = 0; | |
2415 | ||
2416 | *trimmed = 0; | |
2417 | ||
2418 | while (start < end) { | |
2419 | spin_lock(&ctl->tree_lock); | |
2420 | ||
2421 | if (ctl->free_space < minlen) { | |
2422 | spin_unlock(&ctl->tree_lock); | |
2423 | break; | |
2424 | } | |
2425 | ||
2426 | entry = tree_search_offset(ctl, start, 0, 1); | |
2427 | if (!entry) | |
2428 | entry = tree_search_offset(ctl, | |
2429 | offset_to_bitmap(ctl, start), | |
2430 | 1, 1); | |
2431 | ||
2432 | if (!entry || entry->offset >= end) { | |
2433 | spin_unlock(&ctl->tree_lock); | |
2434 | break; | |
2435 | } | |
2436 | ||
2437 | if (entry->bitmap) { | |
2438 | ret = search_bitmap(ctl, entry, &start, &bytes); | |
2439 | if (!ret) { | |
2440 | if (start >= end) { | |
2441 | spin_unlock(&ctl->tree_lock); | |
2442 | break; | |
2443 | } | |
2444 | bytes = min(bytes, end - start); | |
2445 | bitmap_clear_bits(ctl, entry, start, bytes); | |
2446 | if (entry->bytes == 0) | |
2447 | free_bitmap(ctl, entry); | |
2448 | } else { | |
2449 | start = entry->offset + BITS_PER_BITMAP * | |
2450 | block_group->sectorsize; | |
2451 | spin_unlock(&ctl->tree_lock); | |
2452 | ret = 0; | |
2453 | continue; | |
2454 | } | |
2455 | } else { | |
2456 | start = entry->offset; | |
2457 | bytes = min(entry->bytes, end - start); | |
2458 | unlink_free_space(ctl, entry); | |
2459 | kmem_cache_free(btrfs_free_space_cachep, entry); | |
2460 | } | |
2461 | ||
2462 | spin_unlock(&ctl->tree_lock); | |
2463 | ||
2464 | if (bytes >= minlen) { | |
2465 | int update_ret; | |
2466 | update_ret = btrfs_update_reserved_bytes(block_group, | |
2467 | bytes, 1, 1); | |
2468 | ||
2469 | ret = btrfs_error_discard_extent(fs_info->extent_root, | |
2470 | start, | |
2471 | bytes, | |
2472 | &actually_trimmed); | |
2473 | ||
2474 | btrfs_add_free_space(block_group, start, bytes); | |
2475 | if (!update_ret) | |
2476 | btrfs_update_reserved_bytes(block_group, | |
2477 | bytes, 0, 1); | |
2478 | ||
2479 | if (ret) | |
2480 | break; | |
2481 | *trimmed += actually_trimmed; | |
2482 | } | |
2483 | start += bytes; | |
2484 | bytes = 0; | |
2485 | ||
2486 | if (fatal_signal_pending(current)) { | |
2487 | ret = -ERESTARTSYS; | |
2488 | break; | |
2489 | } | |
2490 | ||
2491 | cond_resched(); | |
2492 | } | |
2493 | ||
2494 | return ret; | |
2495 | } | |
2496 | ||
2497 | /* | |
2498 | * Find the left-most item in the cache tree, and then return the | |
2499 | * smallest inode number in the item. | |
2500 | * | |
2501 | * Note: the returned inode number may not be the smallest one in | |
2502 | * the tree, if the left-most item is a bitmap. | |
2503 | */ | |
2504 | u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root) | |
2505 | { | |
2506 | struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl; | |
2507 | struct btrfs_free_space *entry = NULL; | |
2508 | u64 ino = 0; | |
2509 | ||
2510 | spin_lock(&ctl->tree_lock); | |
2511 | ||
2512 | if (RB_EMPTY_ROOT(&ctl->free_space_offset)) | |
2513 | goto out; | |
2514 | ||
2515 | entry = rb_entry(rb_first(&ctl->free_space_offset), | |
2516 | struct btrfs_free_space, offset_index); | |
2517 | ||
2518 | if (!entry->bitmap) { | |
2519 | ino = entry->offset; | |
2520 | ||
2521 | unlink_free_space(ctl, entry); | |
2522 | entry->offset++; | |
2523 | entry->bytes--; | |
2524 | if (!entry->bytes) | |
2525 | kmem_cache_free(btrfs_free_space_cachep, entry); | |
2526 | else | |
2527 | link_free_space(ctl, entry); | |
2528 | } else { | |
2529 | u64 offset = 0; | |
2530 | u64 count = 1; | |
2531 | int ret; | |
2532 | ||
2533 | ret = search_bitmap(ctl, entry, &offset, &count); | |
2534 | BUG_ON(ret); | |
2535 | ||
2536 | ino = offset; | |
2537 | bitmap_clear_bits(ctl, entry, offset, 1); | |
2538 | if (entry->bytes == 0) | |
2539 | free_bitmap(ctl, entry); | |
2540 | } | |
2541 | out: | |
2542 | spin_unlock(&ctl->tree_lock); | |
2543 | ||
2544 | return ino; | |
2545 | } | |
2546 | ||
2547 | struct inode *lookup_free_ino_inode(struct btrfs_root *root, | |
2548 | struct btrfs_path *path) | |
2549 | { | |
2550 | struct inode *inode = NULL; | |
2551 | ||
2552 | spin_lock(&root->cache_lock); | |
2553 | if (root->cache_inode) | |
2554 | inode = igrab(root->cache_inode); | |
2555 | spin_unlock(&root->cache_lock); | |
2556 | if (inode) | |
2557 | return inode; | |
2558 | ||
2559 | inode = __lookup_free_space_inode(root, path, 0); | |
2560 | if (IS_ERR(inode)) | |
2561 | return inode; | |
2562 | ||
2563 | spin_lock(&root->cache_lock); | |
2564 | if (!btrfs_fs_closing(root->fs_info)) | |
2565 | root->cache_inode = igrab(inode); | |
2566 | spin_unlock(&root->cache_lock); | |
2567 | ||
2568 | return inode; | |
2569 | } | |
2570 | ||
2571 | int create_free_ino_inode(struct btrfs_root *root, | |
2572 | struct btrfs_trans_handle *trans, | |
2573 | struct btrfs_path *path) | |
2574 | { | |
2575 | return __create_free_space_inode(root, trans, path, | |
2576 | BTRFS_FREE_INO_OBJECTID, 0); | |
2577 | } | |
2578 | ||
2579 | int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root) | |
2580 | { | |
2581 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
2582 | struct btrfs_path *path; | |
2583 | struct inode *inode; | |
2584 | int ret = 0; | |
2585 | u64 root_gen = btrfs_root_generation(&root->root_item); | |
2586 | ||
2587 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) | |
2588 | return 0; | |
2589 | ||
2590 | /* | |
2591 | * If we're unmounting then just return, since this does a search on the | |
2592 | * normal root and not the commit root and we could deadlock. | |
2593 | */ | |
2594 | if (btrfs_fs_closing(fs_info)) | |
2595 | return 0; | |
2596 | ||
2597 | path = btrfs_alloc_path(); | |
2598 | if (!path) | |
2599 | return 0; | |
2600 | ||
2601 | inode = lookup_free_ino_inode(root, path); | |
2602 | if (IS_ERR(inode)) | |
2603 | goto out; | |
2604 | ||
2605 | if (root_gen != BTRFS_I(inode)->generation) | |
2606 | goto out_put; | |
2607 | ||
2608 | ret = __load_free_space_cache(root, inode, ctl, path, 0); | |
2609 | ||
2610 | if (ret < 0) | |
2611 | printk(KERN_ERR "btrfs: failed to load free ino cache for " | |
2612 | "root %llu\n", root->root_key.objectid); | |
2613 | out_put: | |
2614 | iput(inode); | |
2615 | out: | |
2616 | btrfs_free_path(path); | |
2617 | return ret; | |
2618 | } | |
2619 | ||
2620 | int btrfs_write_out_ino_cache(struct btrfs_root *root, | |
2621 | struct btrfs_trans_handle *trans, | |
2622 | struct btrfs_path *path) | |
2623 | { | |
2624 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
2625 | struct inode *inode; | |
2626 | int ret; | |
2627 | ||
2628 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) | |
2629 | return 0; | |
2630 | ||
2631 | inode = lookup_free_ino_inode(root, path); | |
2632 | if (IS_ERR(inode)) | |
2633 | return 0; | |
2634 | ||
2635 | ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0); | |
2636 | if (ret < 0) | |
2637 | printk(KERN_ERR "btrfs: failed to write free ino cache " | |
2638 | "for root %llu\n", root->root_key.objectid); | |
2639 | ||
2640 | iput(inode); | |
2641 | return ret; | |
2642 | } |