Line data Source code
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 <linux/ratelimit.h>
24 : #include "ctree.h"
25 : #include "free-space-cache.h"
26 : #include "transaction.h"
27 : #include "disk-io.h"
28 : #include "extent_io.h"
29 : #include "inode-map.h"
30 :
31 : #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
32 : #define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
33 :
34 : static int link_free_space(struct btrfs_free_space_ctl *ctl,
35 : struct btrfs_free_space *info);
36 : static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
37 : struct btrfs_free_space *info);
38 :
39 657 : static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
40 : struct btrfs_path *path,
41 : u64 offset)
42 : {
43 : struct btrfs_key key;
44 : struct btrfs_key location;
45 : struct btrfs_disk_key disk_key;
46 : struct btrfs_free_space_header *header;
47 : struct extent_buffer *leaf;
48 : struct inode *inode = NULL;
49 : int ret;
50 :
51 657 : key.objectid = BTRFS_FREE_SPACE_OBJECTID;
52 657 : key.offset = offset;
53 657 : key.type = 0;
54 :
55 657 : ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
56 657 : if (ret < 0)
57 0 : return ERR_PTR(ret);
58 657 : if (ret > 0) {
59 342 : btrfs_release_path(path);
60 342 : return ERR_PTR(-ENOENT);
61 : }
62 :
63 315 : leaf = path->nodes[0];
64 630 : header = btrfs_item_ptr(leaf, path->slots[0],
65 : struct btrfs_free_space_header);
66 : btrfs_free_space_key(leaf, header, &disk_key);
67 : btrfs_disk_key_to_cpu(&location, &disk_key);
68 315 : btrfs_release_path(path);
69 :
70 315 : inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
71 315 : if (!inode)
72 : return ERR_PTR(-ENOENT);
73 315 : if (IS_ERR(inode))
74 : return inode;
75 315 : if (is_bad_inode(inode)) {
76 0 : iput(inode);
77 0 : return ERR_PTR(-ENOENT);
78 : }
79 :
80 315 : mapping_set_gfp_mask(inode->i_mapping,
81 315 : mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
82 :
83 315 : return inode;
84 : }
85 :
86 8704 : struct inode *lookup_free_space_inode(struct btrfs_root *root,
87 : struct btrfs_block_group_cache
88 : *block_group, struct btrfs_path *path)
89 : {
90 : struct inode *inode = NULL;
91 : u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
92 :
93 : spin_lock(&block_group->lock);
94 8704 : if (block_group->inode)
95 8047 : inode = igrab(block_group->inode);
96 : spin_unlock(&block_group->lock);
97 8704 : if (inode)
98 : return inode;
99 :
100 657 : inode = __lookup_free_space_inode(root, path,
101 : block_group->key.objectid);
102 657 : if (IS_ERR(inode))
103 : return inode;
104 :
105 : spin_lock(&block_group->lock);
106 315 : if (!((BTRFS_I(inode)->flags & flags) == flags)) {
107 0 : btrfs_info(root->fs_info,
108 : "Old style space inode found, converting.");
109 0 : BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
110 : BTRFS_INODE_NODATACOW;
111 0 : block_group->disk_cache_state = BTRFS_DC_CLEAR;
112 : }
113 :
114 315 : if (!block_group->iref) {
115 315 : block_group->inode = igrab(inode);
116 315 : block_group->iref = 1;
117 : }
118 : spin_unlock(&block_group->lock);
119 :
120 315 : return inode;
121 : }
122 :
123 179 : static int __create_free_space_inode(struct btrfs_root *root,
124 : struct btrfs_trans_handle *trans,
125 : struct btrfs_path *path,
126 : u64 ino, u64 offset)
127 : {
128 : struct btrfs_key key;
129 : struct btrfs_disk_key disk_key;
130 : struct btrfs_free_space_header *header;
131 : struct btrfs_inode_item *inode_item;
132 : struct extent_buffer *leaf;
133 : u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
134 : int ret;
135 :
136 179 : ret = btrfs_insert_empty_inode(trans, root, path, ino);
137 179 : if (ret)
138 : return ret;
139 :
140 : /* We inline crc's for the free disk space cache */
141 179 : if (ino != BTRFS_FREE_INO_OBJECTID)
142 : flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
143 :
144 179 : leaf = path->nodes[0];
145 358 : inode_item = btrfs_item_ptr(leaf, path->slots[0],
146 : struct btrfs_inode_item);
147 179 : btrfs_item_key(leaf, &disk_key, path->slots[0]);
148 179 : memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
149 : sizeof(*inode_item));
150 179 : btrfs_set_inode_generation(leaf, inode_item, trans->transid);
151 : btrfs_set_inode_size(leaf, inode_item, 0);
152 : btrfs_set_inode_nbytes(leaf, inode_item, 0);
153 : btrfs_set_inode_uid(leaf, inode_item, 0);
154 : btrfs_set_inode_gid(leaf, inode_item, 0);
155 : btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
156 : btrfs_set_inode_flags(leaf, inode_item, flags);
157 : btrfs_set_inode_nlink(leaf, inode_item, 1);
158 179 : btrfs_set_inode_transid(leaf, inode_item, trans->transid);
159 : btrfs_set_inode_block_group(leaf, inode_item, offset);
160 179 : btrfs_mark_buffer_dirty(leaf);
161 179 : btrfs_release_path(path);
162 :
163 179 : key.objectid = BTRFS_FREE_SPACE_OBJECTID;
164 179 : key.offset = offset;
165 179 : key.type = 0;
166 :
167 : ret = btrfs_insert_empty_item(trans, root, path, &key,
168 : sizeof(struct btrfs_free_space_header));
169 179 : if (ret < 0) {
170 0 : btrfs_release_path(path);
171 0 : return ret;
172 : }
173 179 : leaf = path->nodes[0];
174 358 : header = btrfs_item_ptr(leaf, path->slots[0],
175 : struct btrfs_free_space_header);
176 179 : memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
177 : btrfs_set_free_space_key(leaf, header, &disk_key);
178 179 : btrfs_mark_buffer_dirty(leaf);
179 179 : btrfs_release_path(path);
180 :
181 179 : return 0;
182 : }
183 :
184 179 : int create_free_space_inode(struct btrfs_root *root,
185 : struct btrfs_trans_handle *trans,
186 : struct btrfs_block_group_cache *block_group,
187 : struct btrfs_path *path)
188 : {
189 : int ret;
190 : u64 ino;
191 :
192 179 : ret = btrfs_find_free_objectid(root, &ino);
193 179 : if (ret < 0)
194 : return ret;
195 :
196 179 : return __create_free_space_inode(root, trans, path, ino,
197 : block_group->key.objectid);
198 : }
199 :
200 3801 : int btrfs_check_trunc_cache_free_space(struct btrfs_root *root,
201 : struct btrfs_block_rsv *rsv)
202 : {
203 : u64 needed_bytes;
204 : int ret;
205 :
206 : /* 1 for slack space, 1 for updating the inode */
207 3801 : needed_bytes = btrfs_calc_trunc_metadata_size(root, 1) +
208 : btrfs_calc_trans_metadata_size(root, 1);
209 :
210 : spin_lock(&rsv->lock);
211 3801 : if (rsv->reserved < needed_bytes)
212 : ret = -ENOSPC;
213 : else
214 : ret = 0;
215 : spin_unlock(&rsv->lock);
216 3801 : return ret;
217 : }
218 :
219 3801 : int btrfs_truncate_free_space_cache(struct btrfs_root *root,
220 : struct btrfs_trans_handle *trans,
221 : struct inode *inode)
222 : {
223 : int ret = 0;
224 :
225 : btrfs_i_size_write(inode, 0);
226 3801 : truncate_pagecache(inode, 0);
227 :
228 : /*
229 : * We don't need an orphan item because truncating the free space cache
230 : * will never be split across transactions.
231 : */
232 3801 : ret = btrfs_truncate_inode_items(trans, root, inode,
233 : 0, BTRFS_EXTENT_DATA_KEY);
234 3801 : if (ret) {
235 0 : btrfs_abort_transaction(trans, root, ret);
236 0 : return ret;
237 : }
238 :
239 3801 : ret = btrfs_update_inode(trans, root, inode);
240 3801 : if (ret)
241 0 : btrfs_abort_transaction(trans, root, ret);
242 :
243 3801 : return ret;
244 : }
245 :
246 270 : static int readahead_cache(struct inode *inode)
247 : {
248 : struct file_ra_state *ra;
249 : unsigned long last_index;
250 :
251 135 : ra = kzalloc(sizeof(*ra), GFP_NOFS);
252 135 : if (!ra)
253 : return -ENOMEM;
254 :
255 135 : file_ra_state_init(ra, inode->i_mapping);
256 135 : last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
257 :
258 135 : page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
259 :
260 135 : kfree(ra);
261 :
262 135 : return 0;
263 : }
264 :
265 : struct io_ctl {
266 : void *cur, *orig;
267 : struct page *page;
268 : struct page **pages;
269 : struct btrfs_root *root;
270 : unsigned long size;
271 : int index;
272 : int num_pages;
273 : unsigned check_crcs:1;
274 : };
275 :
276 4192 : static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode,
277 : struct btrfs_root *root, int write)
278 : {
279 : int num_pages;
280 : int check_crcs = 0;
281 :
282 4192 : num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
283 : PAGE_CACHE_SHIFT;
284 :
285 4192 : if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
286 : check_crcs = 1;
287 :
288 : /* Make sure we can fit our crcs into the first page */
289 8249 : if (write && check_crcs &&
290 4057 : (num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
291 : return -ENOSPC;
292 :
293 4192 : memset(io_ctl, 0, sizeof(struct io_ctl));
294 :
295 4192 : io_ctl->pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS);
296 4192 : if (!io_ctl->pages)
297 : return -ENOMEM;
298 :
299 4192 : io_ctl->num_pages = num_pages;
300 4192 : io_ctl->root = root;
301 4192 : io_ctl->check_crcs = check_crcs;
302 :
303 4192 : return 0;
304 : }
305 :
306 : static void io_ctl_free(struct io_ctl *io_ctl)
307 : {
308 4192 : kfree(io_ctl->pages);
309 : }
310 :
311 : static void io_ctl_unmap_page(struct io_ctl *io_ctl)
312 : {
313 193862 : if (io_ctl->cur) {
314 : kunmap(io_ctl->page);
315 189670 : io_ctl->cur = NULL;
316 189670 : io_ctl->orig = NULL;
317 : }
318 : }
319 :
320 189670 : static void io_ctl_map_page(struct io_ctl *io_ctl, int clear)
321 : {
322 : ASSERT(io_ctl->index < io_ctl->num_pages);
323 189670 : io_ctl->page = io_ctl->pages[io_ctl->index++];
324 189670 : io_ctl->cur = kmap(io_ctl->page);
325 189670 : io_ctl->orig = io_ctl->cur;
326 189670 : io_ctl->size = PAGE_CACHE_SIZE;
327 189670 : if (clear)
328 180806 : memset(io_ctl->cur, 0, PAGE_CACHE_SIZE);
329 189670 : }
330 :
331 4192 : static void io_ctl_drop_pages(struct io_ctl *io_ctl)
332 : {
333 : int i;
334 :
335 : io_ctl_unmap_page(io_ctl);
336 :
337 197920 : for (i = 0; i < io_ctl->num_pages; i++) {
338 197920 : if (io_ctl->pages[i]) {
339 : ClearPageChecked(io_ctl->pages[i]);
340 197920 : unlock_page(io_ctl->pages[i]);
341 197920 : page_cache_release(io_ctl->pages[i]);
342 : }
343 : }
344 4192 : }
345 :
346 4192 : static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
347 : int uptodate)
348 : {
349 : struct page *page;
350 4192 : gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
351 : int i;
352 :
353 202112 : for (i = 0; i < io_ctl->num_pages; i++) {
354 197920 : page = find_or_create_page(inode->i_mapping, i, mask);
355 197920 : if (!page) {
356 0 : io_ctl_drop_pages(io_ctl);
357 0 : return -ENOMEM;
358 : }
359 197920 : io_ctl->pages[i] = page;
360 206304 : if (uptodate && !PageUptodate(page)) {
361 0 : btrfs_readpage(NULL, page);
362 0 : lock_page(page);
363 0 : if (!PageUptodate(page)) {
364 0 : btrfs_err(BTRFS_I(inode)->root->fs_info,
365 : "error reading free space cache");
366 0 : io_ctl_drop_pages(io_ctl);
367 0 : return -EIO;
368 : }
369 : }
370 : }
371 :
372 197920 : for (i = 0; i < io_ctl->num_pages; i++) {
373 197920 : clear_page_dirty_for_io(io_ctl->pages[i]);
374 197920 : set_page_extent_mapped(io_ctl->pages[i]);
375 : }
376 :
377 : return 0;
378 : }
379 :
380 4057 : static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
381 : {
382 : __le64 *val;
383 :
384 4057 : io_ctl_map_page(io_ctl, 1);
385 :
386 : /*
387 : * Skip the csum areas. If we don't check crcs then we just have a
388 : * 64bit chunk at the front of the first page.
389 : */
390 4057 : if (io_ctl->check_crcs) {
391 4057 : io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
392 4057 : io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
393 : } else {
394 0 : io_ctl->cur += sizeof(u64);
395 0 : io_ctl->size -= sizeof(u64) * 2;
396 : }
397 :
398 4057 : val = io_ctl->cur;
399 4057 : *val = cpu_to_le64(generation);
400 4057 : io_ctl->cur += sizeof(u64);
401 4057 : }
402 :
403 135 : static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
404 : {
405 : __le64 *gen;
406 :
407 : /*
408 : * Skip the crc area. If we don't check crcs then we just have a 64bit
409 : * chunk at the front of the first page.
410 : */
411 135 : if (io_ctl->check_crcs) {
412 135 : io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
413 135 : io_ctl->size -= sizeof(u64) +
414 : (sizeof(u32) * io_ctl->num_pages);
415 : } else {
416 0 : io_ctl->cur += sizeof(u64);
417 0 : io_ctl->size -= sizeof(u64) * 2;
418 : }
419 :
420 135 : gen = io_ctl->cur;
421 135 : if (le64_to_cpu(*gen) != generation) {
422 0 : printk_ratelimited(KERN_ERR "BTRFS: space cache generation "
423 : "(%Lu) does not match inode (%Lu)\n", *gen,
424 : generation);
425 : io_ctl_unmap_page(io_ctl);
426 : return -EIO;
427 : }
428 135 : io_ctl->cur += sizeof(u64);
429 135 : return 0;
430 : }
431 :
432 188436 : static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
433 : {
434 : u32 *tmp;
435 188436 : u32 crc = ~(u32)0;
436 : unsigned offset = 0;
437 :
438 188436 : if (!io_ctl->check_crcs) {
439 : io_ctl_unmap_page(io_ctl);
440 188436 : return;
441 : }
442 :
443 188436 : if (index == 0)
444 4057 : offset = sizeof(u32) * io_ctl->num_pages;
445 :
446 188436 : crc = btrfs_csum_data(io_ctl->orig + offset, crc,
447 : PAGE_CACHE_SIZE - offset);
448 188436 : btrfs_csum_final(crc, (char *)&crc);
449 : io_ctl_unmap_page(io_ctl);
450 188436 : tmp = kmap(io_ctl->pages[0]);
451 188436 : tmp += index;
452 188436 : *tmp = crc;
453 : kunmap(io_ctl->pages[0]);
454 : }
455 :
456 136 : static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
457 : {
458 : u32 *tmp, val;
459 136 : u32 crc = ~(u32)0;
460 : unsigned offset = 0;
461 :
462 136 : if (!io_ctl->check_crcs) {
463 0 : io_ctl_map_page(io_ctl, 0);
464 0 : return 0;
465 : }
466 :
467 136 : if (index == 0)
468 135 : offset = sizeof(u32) * io_ctl->num_pages;
469 :
470 136 : tmp = kmap(io_ctl->pages[0]);
471 136 : tmp += index;
472 136 : val = *tmp;
473 : kunmap(io_ctl->pages[0]);
474 :
475 136 : io_ctl_map_page(io_ctl, 0);
476 136 : crc = btrfs_csum_data(io_ctl->orig + offset, crc,
477 : PAGE_CACHE_SIZE - offset);
478 136 : btrfs_csum_final(crc, (char *)&crc);
479 136 : if (val != crc) {
480 0 : printk_ratelimited(KERN_ERR "BTRFS: csum mismatch on free "
481 : "space cache\n");
482 : io_ctl_unmap_page(io_ctl);
483 : return -EIO;
484 : }
485 :
486 : return 0;
487 : }
488 :
489 124062 : static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes,
490 : void *bitmap)
491 : {
492 : struct btrfs_free_space_entry *entry;
493 :
494 124062 : if (!io_ctl->cur)
495 : return -ENOSPC;
496 :
497 : entry = io_ctl->cur;
498 124062 : entry->offset = cpu_to_le64(offset);
499 124062 : entry->bytes = cpu_to_le64(bytes);
500 124062 : entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
501 : BTRFS_FREE_SPACE_EXTENT;
502 124062 : io_ctl->cur += sizeof(struct btrfs_free_space_entry);
503 124062 : io_ctl->size -= sizeof(struct btrfs_free_space_entry);
504 :
505 124062 : if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
506 : return 0;
507 :
508 4 : io_ctl_set_crc(io_ctl, io_ctl->index - 1);
509 :
510 : /* No more pages to map */
511 4 : if (io_ctl->index >= io_ctl->num_pages)
512 : return 0;
513 :
514 : /* map the next page */
515 4 : io_ctl_map_page(io_ctl, 1);
516 4 : return 0;
517 : }
518 :
519 7633 : static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap)
520 : {
521 7633 : if (!io_ctl->cur)
522 : return -ENOSPC;
523 :
524 : /*
525 : * If we aren't at the start of the current page, unmap this one and
526 : * map the next one if there is any left.
527 : */
528 7633 : if (io_ctl->cur != io_ctl->orig) {
529 1097 : io_ctl_set_crc(io_ctl, io_ctl->index - 1);
530 1097 : if (io_ctl->index >= io_ctl->num_pages)
531 : return -ENOSPC;
532 1097 : io_ctl_map_page(io_ctl, 0);
533 : }
534 :
535 7633 : memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE);
536 7633 : io_ctl_set_crc(io_ctl, io_ctl->index - 1);
537 7633 : if (io_ctl->index < io_ctl->num_pages)
538 7633 : io_ctl_map_page(io_ctl, 0);
539 : return 0;
540 : }
541 :
542 4057 : static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl)
543 : {
544 : /*
545 : * If we're not on the boundary we know we've modified the page and we
546 : * need to crc the page.
547 : */
548 4057 : if (io_ctl->cur != io_ctl->orig)
549 2959 : io_ctl_set_crc(io_ctl, io_ctl->index - 1);
550 : else
551 : io_ctl_unmap_page(io_ctl);
552 :
553 180802 : while (io_ctl->index < io_ctl->num_pages) {
554 176745 : io_ctl_map_page(io_ctl, 1);
555 176745 : io_ctl_set_crc(io_ctl, io_ctl->index - 1);
556 : }
557 4057 : }
558 :
559 1614 : static int io_ctl_read_entry(struct io_ctl *io_ctl,
560 : struct btrfs_free_space *entry, u8 *type)
561 : {
562 : struct btrfs_free_space_entry *e;
563 : int ret;
564 :
565 1614 : if (!io_ctl->cur) {
566 0 : ret = io_ctl_check_crc(io_ctl, io_ctl->index);
567 0 : if (ret)
568 : return ret;
569 : }
570 :
571 1614 : e = io_ctl->cur;
572 1614 : entry->offset = le64_to_cpu(e->offset);
573 1614 : entry->bytes = le64_to_cpu(e->bytes);
574 1614 : *type = e->type;
575 1614 : io_ctl->cur += sizeof(struct btrfs_free_space_entry);
576 1614 : io_ctl->size -= sizeof(struct btrfs_free_space_entry);
577 :
578 1614 : if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
579 : return 0;
580 :
581 : io_ctl_unmap_page(io_ctl);
582 :
583 : return 0;
584 : }
585 :
586 1 : static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
587 : struct btrfs_free_space *entry)
588 : {
589 : int ret;
590 :
591 1 : ret = io_ctl_check_crc(io_ctl, io_ctl->index);
592 1 : if (ret)
593 : return ret;
594 :
595 1 : memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE);
596 : io_ctl_unmap_page(io_ctl);
597 :
598 : return 0;
599 : }
600 :
601 : /*
602 : * Since we attach pinned extents after the fact we can have contiguous sections
603 : * of free space that are split up in entries. This poses a problem with the
604 : * tree logging stuff since it could have allocated across what appears to be 2
605 : * entries since we would have merged the entries when adding the pinned extents
606 : * back to the free space cache. So run through the space cache that we just
607 : * loaded and merge contiguous entries. This will make the log replay stuff not
608 : * blow up and it will make for nicer allocator behavior.
609 : */
610 135 : static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
611 : {
612 : struct btrfs_free_space *e, *prev = NULL;
613 : struct rb_node *n;
614 :
615 : again:
616 : spin_lock(&ctl->tree_lock);
617 3922 : for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
618 : e = rb_entry(n, struct btrfs_free_space, offset_index);
619 3787 : if (!prev)
620 : goto next;
621 3412 : if (e->bitmap || prev->bitmap)
622 : goto next;
623 3411 : if (prev->offset + prev->bytes == e->offset) {
624 : unlink_free_space(ctl, prev);
625 : unlink_free_space(ctl, e);
626 240 : prev->bytes += e->bytes;
627 240 : kmem_cache_free(btrfs_free_space_cachep, e);
628 240 : link_free_space(ctl, prev);
629 : prev = NULL;
630 : spin_unlock(&ctl->tree_lock);
631 : goto again;
632 : }
633 : next:
634 : prev = e;
635 : }
636 : spin_unlock(&ctl->tree_lock);
637 135 : }
638 :
639 270 : static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
640 : struct btrfs_free_space_ctl *ctl,
641 : struct btrfs_path *path, u64 offset)
642 : {
643 : struct btrfs_free_space_header *header;
644 : struct extent_buffer *leaf;
645 : struct io_ctl io_ctl;
646 : struct btrfs_key key;
647 : struct btrfs_free_space *e, *n;
648 : struct list_head bitmaps;
649 : u64 num_entries;
650 : u64 num_bitmaps;
651 : u64 generation;
652 : u8 type;
653 : int ret = 0;
654 :
655 : INIT_LIST_HEAD(&bitmaps);
656 :
657 : /* Nothing in the space cache, goodbye */
658 135 : if (!i_size_read(inode))
659 : return 0;
660 :
661 135 : key.objectid = BTRFS_FREE_SPACE_OBJECTID;
662 135 : key.offset = offset;
663 135 : key.type = 0;
664 :
665 135 : ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
666 135 : if (ret < 0)
667 : return 0;
668 135 : else if (ret > 0) {
669 0 : btrfs_release_path(path);
670 0 : return 0;
671 : }
672 :
673 : ret = -1;
674 :
675 135 : leaf = path->nodes[0];
676 270 : header = btrfs_item_ptr(leaf, path->slots[0],
677 : struct btrfs_free_space_header);
678 : num_entries = btrfs_free_space_entries(leaf, header);
679 : num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
680 : generation = btrfs_free_space_generation(leaf, header);
681 135 : btrfs_release_path(path);
682 :
683 135 : if (!BTRFS_I(inode)->generation) {
684 0 : btrfs_info(root->fs_info,
685 : "The free space cache file (%llu) is invalid. skip it\n",
686 : offset);
687 0 : return 0;
688 : }
689 :
690 135 : if (BTRFS_I(inode)->generation != generation) {
691 0 : btrfs_err(root->fs_info,
692 : "free space inode generation (%llu) "
693 : "did not match free space cache generation (%llu)",
694 : BTRFS_I(inode)->generation, generation);
695 0 : return 0;
696 : }
697 :
698 135 : if (!num_entries)
699 : return 0;
700 :
701 135 : ret = io_ctl_init(&io_ctl, inode, root, 0);
702 135 : if (ret)
703 : return ret;
704 :
705 135 : ret = readahead_cache(inode);
706 135 : if (ret)
707 : goto out;
708 :
709 135 : ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
710 135 : if (ret)
711 : goto out;
712 :
713 135 : ret = io_ctl_check_crc(&io_ctl, 0);
714 135 : if (ret)
715 : goto free_cache;
716 :
717 135 : ret = io_ctl_check_generation(&io_ctl, generation);
718 135 : if (ret)
719 : goto free_cache;
720 :
721 1749 : while (num_entries) {
722 1614 : e = kmem_cache_zalloc(btrfs_free_space_cachep,
723 : GFP_NOFS);
724 1614 : if (!e)
725 : goto free_cache;
726 :
727 1614 : ret = io_ctl_read_entry(&io_ctl, e, &type);
728 1614 : if (ret) {
729 0 : kmem_cache_free(btrfs_free_space_cachep, e);
730 0 : goto free_cache;
731 : }
732 :
733 1614 : if (!e->bytes) {
734 0 : kmem_cache_free(btrfs_free_space_cachep, e);
735 0 : goto free_cache;
736 : }
737 :
738 1614 : if (type == BTRFS_FREE_SPACE_EXTENT) {
739 : spin_lock(&ctl->tree_lock);
740 1613 : ret = link_free_space(ctl, e);
741 : spin_unlock(&ctl->tree_lock);
742 1613 : if (ret) {
743 0 : btrfs_err(root->fs_info,
744 : "Duplicate entries in free space cache, dumping");
745 0 : kmem_cache_free(btrfs_free_space_cachep, e);
746 0 : goto free_cache;
747 : }
748 : } else {
749 : ASSERT(num_bitmaps);
750 : num_bitmaps--;
751 1 : e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
752 1 : if (!e->bitmap) {
753 0 : kmem_cache_free(
754 : btrfs_free_space_cachep, e);
755 0 : goto free_cache;
756 : }
757 : spin_lock(&ctl->tree_lock);
758 1 : ret = link_free_space(ctl, e);
759 1 : ctl->total_bitmaps++;
760 1 : ctl->op->recalc_thresholds(ctl);
761 : spin_unlock(&ctl->tree_lock);
762 1 : if (ret) {
763 0 : btrfs_err(root->fs_info,
764 : "Duplicate entries in free space cache, dumping");
765 0 : kmem_cache_free(btrfs_free_space_cachep, e);
766 0 : goto free_cache;
767 : }
768 1 : list_add_tail(&e->list, &bitmaps);
769 : }
770 :
771 1614 : num_entries--;
772 : }
773 :
774 : io_ctl_unmap_page(&io_ctl);
775 :
776 : /*
777 : * We add the bitmaps at the end of the entries in order that
778 : * the bitmap entries are added to the cache.
779 : */
780 136 : list_for_each_entry_safe(e, n, &bitmaps, list) {
781 : list_del_init(&e->list);
782 1 : ret = io_ctl_read_bitmap(&io_ctl, e);
783 1 : if (ret)
784 : goto free_cache;
785 : }
786 :
787 135 : io_ctl_drop_pages(&io_ctl);
788 135 : merge_space_tree(ctl);
789 : ret = 1;
790 : out:
791 135 : io_ctl_free(&io_ctl);
792 135 : return ret;
793 : free_cache:
794 0 : io_ctl_drop_pages(&io_ctl);
795 0 : __btrfs_remove_free_space_cache(ctl);
796 0 : goto out;
797 : }
798 :
799 343 : int load_free_space_cache(struct btrfs_fs_info *fs_info,
800 : struct btrfs_block_group_cache *block_group)
801 : {
802 343 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
803 343 : struct btrfs_root *root = fs_info->tree_root;
804 : struct inode *inode;
805 : struct btrfs_path *path;
806 : int ret = 0;
807 : bool matched;
808 : u64 used = btrfs_block_group_used(&block_group->item);
809 :
810 : /*
811 : * If this block group has been marked to be cleared for one reason or
812 : * another then we can't trust the on disk cache, so just return.
813 : */
814 : spin_lock(&block_group->lock);
815 343 : if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
816 : spin_unlock(&block_group->lock);
817 107 : return 0;
818 : }
819 : spin_unlock(&block_group->lock);
820 :
821 236 : path = btrfs_alloc_path();
822 236 : if (!path)
823 : return 0;
824 236 : path->search_commit_root = 1;
825 236 : path->skip_locking = 1;
826 :
827 236 : inode = lookup_free_space_inode(root, block_group, path);
828 236 : if (IS_ERR(inode)) {
829 101 : btrfs_free_path(path);
830 101 : return 0;
831 : }
832 :
833 : /* We may have converted the inode and made the cache invalid. */
834 : spin_lock(&block_group->lock);
835 135 : if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
836 : spin_unlock(&block_group->lock);
837 0 : btrfs_free_path(path);
838 0 : goto out;
839 : }
840 : spin_unlock(&block_group->lock);
841 :
842 135 : ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
843 : path, block_group->key.objectid);
844 135 : btrfs_free_path(path);
845 135 : if (ret <= 0)
846 : goto out;
847 :
848 : spin_lock(&ctl->tree_lock);
849 270 : matched = (ctl->free_space == (block_group->key.offset - used -
850 135 : block_group->bytes_super));
851 : spin_unlock(&ctl->tree_lock);
852 :
853 135 : if (!matched) {
854 0 : __btrfs_remove_free_space_cache(ctl);
855 0 : btrfs_warn(fs_info, "block group %llu has wrong amount of free space",
856 : block_group->key.objectid);
857 : ret = -1;
858 : }
859 : out:
860 135 : if (ret < 0) {
861 : /* This cache is bogus, make sure it gets cleared */
862 : spin_lock(&block_group->lock);
863 0 : block_group->disk_cache_state = BTRFS_DC_CLEAR;
864 : spin_unlock(&block_group->lock);
865 : ret = 0;
866 :
867 0 : btrfs_warn(fs_info, "failed to load free space cache for block group %llu, rebuild it now",
868 : block_group->key.objectid);
869 : }
870 :
871 135 : iput(inode);
872 135 : return ret;
873 : }
874 :
875 : static noinline_for_stack
876 4057 : int write_cache_extent_entries(struct io_ctl *io_ctl,
877 : struct btrfs_free_space_ctl *ctl,
878 : struct btrfs_block_group_cache *block_group,
879 : int *entries, int *bitmaps,
880 : struct list_head *bitmap_list)
881 : {
882 : int ret;
883 : struct btrfs_free_cluster *cluster = NULL;
884 4057 : struct rb_node *node = rb_first(&ctl->free_space_offset);
885 :
886 : /* Get the cluster for this block_group if it exists */
887 8114 : if (block_group && !list_empty(&block_group->cluster_list)) {
888 1944 : cluster = list_entry(block_group->cluster_list.next,
889 : struct btrfs_free_cluster,
890 : block_group_list);
891 : }
892 :
893 4057 : if (!node && cluster) {
894 229 : node = rb_first(&cluster->root);
895 : cluster = NULL;
896 : }
897 :
898 : /* Write out the extent entries */
899 97893 : while (node) {
900 : struct btrfs_free_space *e;
901 :
902 : e = rb_entry(node, struct btrfs_free_space, offset_index);
903 93836 : *entries += 1;
904 :
905 93836 : ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
906 93836 : e->bitmap);
907 93836 : if (ret)
908 : goto fail;
909 :
910 93836 : if (e->bitmap) {
911 7633 : list_add_tail(&e->list, bitmap_list);
912 7633 : *bitmaps += 1;
913 : }
914 93836 : node = rb_next(node);
915 93836 : if (!node && cluster) {
916 1715 : node = rb_first(&cluster->root);
917 : cluster = NULL;
918 : }
919 : }
920 : return 0;
921 : fail:
922 : return -ENOSPC;
923 : }
924 :
925 : static noinline_for_stack int
926 4057 : update_cache_item(struct btrfs_trans_handle *trans,
927 : struct btrfs_root *root,
928 : struct inode *inode,
929 : struct btrfs_path *path, u64 offset,
930 : int entries, int bitmaps)
931 : {
932 : struct btrfs_key key;
933 : struct btrfs_free_space_header *header;
934 : struct extent_buffer *leaf;
935 : int ret;
936 :
937 4057 : key.objectid = BTRFS_FREE_SPACE_OBJECTID;
938 4057 : key.offset = offset;
939 4057 : key.type = 0;
940 :
941 4057 : ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
942 4057 : if (ret < 0) {
943 0 : clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
944 : EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
945 : GFP_NOFS);
946 0 : goto fail;
947 : }
948 4057 : leaf = path->nodes[0];
949 4057 : if (ret > 0) {
950 : struct btrfs_key found_key;
951 : ASSERT(path->slots[0]);
952 0 : path->slots[0]--;
953 0 : btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
954 0 : if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
955 0 : found_key.offset != offset) {
956 0 : clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
957 0 : inode->i_size - 1,
958 : EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
959 : NULL, GFP_NOFS);
960 0 : btrfs_release_path(path);
961 0 : goto fail;
962 : }
963 : }
964 :
965 4057 : BTRFS_I(inode)->generation = trans->transid;
966 8114 : header = btrfs_item_ptr(leaf, path->slots[0],
967 : struct btrfs_free_space_header);
968 4057 : btrfs_set_free_space_entries(leaf, header, entries);
969 4057 : btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
970 4057 : btrfs_set_free_space_generation(leaf, header, trans->transid);
971 4057 : btrfs_mark_buffer_dirty(leaf);
972 4057 : btrfs_release_path(path);
973 :
974 4057 : return 0;
975 :
976 : fail:
977 : return -1;
978 : }
979 :
980 : static noinline_for_stack int
981 4057 : write_pinned_extent_entries(struct btrfs_root *root,
982 : struct btrfs_block_group_cache *block_group,
983 : struct io_ctl *io_ctl,
984 : int *entries)
985 : {
986 : u64 start, extent_start, extent_end, len;
987 : struct extent_io_tree *unpin = NULL;
988 : int ret;
989 :
990 4057 : if (!block_group)
991 : return 0;
992 :
993 : /*
994 : * We want to add any pinned extents to our free space cache
995 : * so we don't leak the space
996 : *
997 : * We shouldn't have switched the pinned extents yet so this is the
998 : * right one
999 : */
1000 4057 : unpin = root->fs_info->pinned_extents;
1001 :
1002 4057 : start = block_group->key.objectid;
1003 :
1004 34283 : while (start < block_group->key.objectid + block_group->key.offset) {
1005 34280 : ret = find_first_extent_bit(unpin, start,
1006 : &extent_start, &extent_end,
1007 : EXTENT_DIRTY, NULL);
1008 34280 : if (ret)
1009 : return 0;
1010 :
1011 : /* This pinned extent is out of our range */
1012 64162 : if (extent_start >= block_group->key.objectid +
1013 32081 : block_group->key.offset)
1014 : return 0;
1015 :
1016 30226 : extent_start = max(extent_start, start);
1017 30226 : extent_end = min(block_group->key.objectid +
1018 : block_group->key.offset, extent_end + 1);
1019 30226 : len = extent_end - extent_start;
1020 :
1021 30226 : *entries += 1;
1022 30226 : ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1023 30226 : if (ret)
1024 : return -ENOSPC;
1025 :
1026 30226 : start = extent_end;
1027 : }
1028 :
1029 : return 0;
1030 : }
1031 :
1032 : static noinline_for_stack int
1033 4057 : write_bitmap_entries(struct io_ctl *io_ctl, struct list_head *bitmap_list)
1034 : {
1035 : struct list_head *pos, *n;
1036 : int ret;
1037 :
1038 : /* Write out the bitmaps */
1039 11690 : list_for_each_safe(pos, n, bitmap_list) {
1040 : struct btrfs_free_space *entry =
1041 : list_entry(pos, struct btrfs_free_space, list);
1042 :
1043 7633 : ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1044 7633 : if (ret)
1045 : return -ENOSPC;
1046 7633 : list_del_init(&entry->list);
1047 : }
1048 :
1049 : return 0;
1050 : }
1051 :
1052 4057 : static int flush_dirty_cache(struct inode *inode)
1053 : {
1054 : int ret;
1055 :
1056 4057 : ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1057 4057 : if (ret)
1058 0 : clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1059 : EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
1060 : GFP_NOFS);
1061 :
1062 4057 : return ret;
1063 : }
1064 :
1065 : static void noinline_for_stack
1066 0 : cleanup_write_cache_enospc(struct inode *inode,
1067 : struct io_ctl *io_ctl,
1068 : struct extent_state **cached_state,
1069 : struct list_head *bitmap_list)
1070 : {
1071 : struct list_head *pos, *n;
1072 :
1073 0 : list_for_each_safe(pos, n, bitmap_list) {
1074 : struct btrfs_free_space *entry =
1075 : list_entry(pos, struct btrfs_free_space, list);
1076 0 : list_del_init(&entry->list);
1077 : }
1078 0 : io_ctl_drop_pages(io_ctl);
1079 0 : unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1080 0 : i_size_read(inode) - 1, cached_state,
1081 : GFP_NOFS);
1082 0 : }
1083 :
1084 : /**
1085 : * __btrfs_write_out_cache - write out cached info to an inode
1086 : * @root - the root the inode belongs to
1087 : * @ctl - the free space cache we are going to write out
1088 : * @block_group - the block_group for this cache if it belongs to a block_group
1089 : * @trans - the trans handle
1090 : * @path - the path to use
1091 : * @offset - the offset for the key we'll insert
1092 : *
1093 : * This function writes out a free space cache struct to disk for quick recovery
1094 : * on mount. This will return 0 if it was successfull in writing the cache out,
1095 : * and -1 if it was not.
1096 : */
1097 20285 : static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1098 : struct btrfs_free_space_ctl *ctl,
1099 : struct btrfs_block_group_cache *block_group,
1100 : struct btrfs_trans_handle *trans,
1101 : struct btrfs_path *path, u64 offset)
1102 : {
1103 4057 : struct extent_state *cached_state = NULL;
1104 : struct io_ctl io_ctl;
1105 4057 : LIST_HEAD(bitmap_list);
1106 4057 : int entries = 0;
1107 4057 : int bitmaps = 0;
1108 : int ret;
1109 :
1110 4057 : if (!i_size_read(inode))
1111 : return -1;
1112 :
1113 4057 : ret = io_ctl_init(&io_ctl, inode, root, 1);
1114 4057 : if (ret)
1115 : return -1;
1116 :
1117 4057 : if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1118 2042 : down_write(&block_group->data_rwsem);
1119 : spin_lock(&block_group->lock);
1120 2042 : if (block_group->delalloc_bytes) {
1121 0 : block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1122 : spin_unlock(&block_group->lock);
1123 0 : up_write(&block_group->data_rwsem);
1124 0 : BTRFS_I(inode)->generation = 0;
1125 : ret = 0;
1126 0 : goto out;
1127 : }
1128 : spin_unlock(&block_group->lock);
1129 : }
1130 :
1131 : /* Lock all pages first so we can lock the extent safely. */
1132 4057 : io_ctl_prepare_pages(&io_ctl, inode, 0);
1133 :
1134 4057 : lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1135 : 0, &cached_state);
1136 :
1137 4057 : io_ctl_set_generation(&io_ctl, trans->transid);
1138 :
1139 : /* Write out the extent entries in the free space cache */
1140 4057 : ret = write_cache_extent_entries(&io_ctl, ctl,
1141 : block_group, &entries, &bitmaps,
1142 : &bitmap_list);
1143 4057 : if (ret)
1144 : goto out_nospc;
1145 :
1146 : /*
1147 : * Some spaces that are freed in the current transaction are pinned,
1148 : * they will be added into free space cache after the transaction is
1149 : * committed, we shouldn't lose them.
1150 : */
1151 4057 : ret = write_pinned_extent_entries(root, block_group, &io_ctl, &entries);
1152 4057 : if (ret)
1153 : goto out_nospc;
1154 :
1155 : /* At last, we write out all the bitmaps. */
1156 4057 : ret = write_bitmap_entries(&io_ctl, &bitmap_list);
1157 4057 : if (ret)
1158 : goto out_nospc;
1159 :
1160 : /* Zero out the rest of the pages just to make sure */
1161 4057 : io_ctl_zero_remaining_pages(&io_ctl);
1162 :
1163 : /* Everything is written out, now we dirty the pages in the file. */
1164 4057 : ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
1165 : 0, i_size_read(inode), &cached_state);
1166 4057 : if (ret)
1167 : goto out_nospc;
1168 :
1169 4057 : if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1170 2042 : up_write(&block_group->data_rwsem);
1171 : /*
1172 : * Release the pages and unlock the extent, we will flush
1173 : * them out later
1174 : */
1175 4057 : io_ctl_drop_pages(&io_ctl);
1176 :
1177 4057 : unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1178 4057 : i_size_read(inode) - 1, &cached_state, GFP_NOFS);
1179 :
1180 : /* Flush the dirty pages in the cache file. */
1181 4057 : ret = flush_dirty_cache(inode);
1182 4057 : if (ret)
1183 : goto out;
1184 :
1185 : /* Update the cache item to tell everyone this cache file is valid. */
1186 4057 : ret = update_cache_item(trans, root, inode, path, offset,
1187 : entries, bitmaps);
1188 : out:
1189 4057 : io_ctl_free(&io_ctl);
1190 4057 : if (ret) {
1191 0 : invalidate_inode_pages2(inode->i_mapping);
1192 0 : BTRFS_I(inode)->generation = 0;
1193 : }
1194 4057 : btrfs_update_inode(trans, root, inode);
1195 4057 : return ret;
1196 :
1197 : out_nospc:
1198 0 : cleanup_write_cache_enospc(inode, &io_ctl, &cached_state, &bitmap_list);
1199 :
1200 0 : if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1201 0 : up_write(&block_group->data_rwsem);
1202 :
1203 : goto out;
1204 : }
1205 :
1206 4057 : int btrfs_write_out_cache(struct btrfs_root *root,
1207 : struct btrfs_trans_handle *trans,
1208 : struct btrfs_block_group_cache *block_group,
1209 : struct btrfs_path *path)
1210 : {
1211 4057 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1212 : struct inode *inode;
1213 : int ret = 0;
1214 :
1215 4057 : root = root->fs_info->tree_root;
1216 :
1217 : spin_lock(&block_group->lock);
1218 4057 : if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1219 : spin_unlock(&block_group->lock);
1220 0 : return 0;
1221 : }
1222 :
1223 4057 : if (block_group->delalloc_bytes) {
1224 0 : block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1225 : spin_unlock(&block_group->lock);
1226 0 : return 0;
1227 : }
1228 : spin_unlock(&block_group->lock);
1229 :
1230 4057 : inode = lookup_free_space_inode(root, block_group, path);
1231 4057 : if (IS_ERR(inode))
1232 : return 0;
1233 :
1234 4057 : ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans,
1235 : path, block_group->key.objectid);
1236 4057 : if (ret) {
1237 : spin_lock(&block_group->lock);
1238 0 : block_group->disk_cache_state = BTRFS_DC_ERROR;
1239 : spin_unlock(&block_group->lock);
1240 : ret = 0;
1241 : #ifdef DEBUG
1242 : btrfs_err(root->fs_info,
1243 : "failed to write free space cache for block group %llu",
1244 : block_group->key.objectid);
1245 : #endif
1246 : }
1247 :
1248 4057 : iput(inode);
1249 4057 : return ret;
1250 : }
1251 :
1252 : static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1253 : u64 offset)
1254 : {
1255 : ASSERT(offset >= bitmap_start);
1256 58802 : offset -= bitmap_start;
1257 : return (unsigned long)(div_u64(offset, unit));
1258 : }
1259 :
1260 : static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1261 : {
1262 : return (unsigned long)(div_u64(bytes, unit));
1263 : }
1264 :
1265 : static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1266 : u64 offset)
1267 : {
1268 : u64 bitmap_start;
1269 : u64 bytes_per_bitmap;
1270 :
1271 85625 : bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1272 85625 : bitmap_start = offset - ctl->start;
1273 : bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1274 85625 : bitmap_start *= bytes_per_bitmap;
1275 85625 : bitmap_start += ctl->start;
1276 :
1277 : return bitmap_start;
1278 : }
1279 :
1280 80485 : static int tree_insert_offset(struct rb_root *root, u64 offset,
1281 : struct rb_node *node, int bitmap)
1282 : {
1283 80485 : struct rb_node **p = &root->rb_node;
1284 : struct rb_node *parent = NULL;
1285 : struct btrfs_free_space *info;
1286 :
1287 339571 : while (*p) {
1288 : parent = *p;
1289 : info = rb_entry(parent, struct btrfs_free_space, offset_index);
1290 :
1291 178601 : if (offset < info->offset) {
1292 57597 : p = &(*p)->rb_left;
1293 121004 : } else if (offset > info->offset) {
1294 121003 : p = &(*p)->rb_right;
1295 : } else {
1296 : /*
1297 : * we could have a bitmap entry and an extent entry
1298 : * share the same offset. If this is the case, we want
1299 : * the extent entry to always be found first if we do a
1300 : * linear search through the tree, since we want to have
1301 : * the quickest allocation time, and allocating from an
1302 : * extent is faster than allocating from a bitmap. So
1303 : * if we're inserting a bitmap and we find an entry at
1304 : * this offset, we want to go right, or after this entry
1305 : * logically. If we are inserting an extent and we've
1306 : * found a bitmap, we want to go left, or before
1307 : * logically.
1308 : */
1309 1 : if (bitmap) {
1310 1 : if (info->bitmap) {
1311 0 : WARN_ON_ONCE(1);
1312 : return -EEXIST;
1313 : }
1314 1 : p = &(*p)->rb_right;
1315 : } else {
1316 0 : if (!info->bitmap) {
1317 0 : WARN_ON_ONCE(1);
1318 : return -EEXIST;
1319 : }
1320 0 : p = &(*p)->rb_left;
1321 : }
1322 : }
1323 : }
1324 :
1325 : rb_link_node(node, parent, p);
1326 80485 : rb_insert_color(node, root);
1327 :
1328 80486 : return 0;
1329 : }
1330 :
1331 : /*
1332 : * searches the tree for the given offset.
1333 : *
1334 : * fuzzy - If this is set, then we are trying to make an allocation, and we just
1335 : * want a section that has at least bytes size and comes at or after the given
1336 : * offset.
1337 : */
1338 : static struct btrfs_free_space *
1339 144316 : tree_search_offset(struct btrfs_free_space_ctl *ctl,
1340 : u64 offset, int bitmap_only, int fuzzy)
1341 : {
1342 144316 : struct rb_node *n = ctl->free_space_offset.rb_node;
1343 : struct btrfs_free_space *entry, *prev = NULL;
1344 :
1345 : /* find entry that is closest to the 'offset' */
1346 : while (1) {
1347 670428 : if (!n) {
1348 : entry = NULL;
1349 : break;
1350 : }
1351 :
1352 : entry = rb_entry(n, struct btrfs_free_space, offset_index);
1353 : prev = entry;
1354 :
1355 540113 : if (offset < entry->offset)
1356 237523 : n = n->rb_left;
1357 302590 : else if (offset > entry->offset)
1358 288589 : n = n->rb_right;
1359 : else
1360 : break;
1361 : }
1362 :
1363 144316 : if (bitmap_only) {
1364 4772 : if (!entry)
1365 : return NULL;
1366 4680 : if (entry->bitmap)
1367 : return entry;
1368 :
1369 : /*
1370 : * bitmap entry and extent entry may share same offset,
1371 : * in that case, bitmap entry comes after extent entry.
1372 : */
1373 162 : n = rb_next(n);
1374 162 : if (!n)
1375 : return NULL;
1376 : entry = rb_entry(n, struct btrfs_free_space, offset_index);
1377 162 : if (entry->offset != offset)
1378 : return NULL;
1379 :
1380 160 : WARN_ON(!entry->bitmap);
1381 : return entry;
1382 139544 : } else if (entry) {
1383 9325 : if (entry->bitmap) {
1384 : /*
1385 : * if previous extent entry covers the offset,
1386 : * we should return it instead of the bitmap entry
1387 : */
1388 5250 : n = rb_prev(&entry->offset_index);
1389 5250 : if (n) {
1390 : prev = rb_entry(n, struct btrfs_free_space,
1391 : offset_index);
1392 6729 : if (!prev->bitmap &&
1393 2987 : prev->offset + prev->bytes > offset)
1394 : entry = prev;
1395 : }
1396 : }
1397 : return entry;
1398 : }
1399 :
1400 130219 : if (!prev)
1401 : return NULL;
1402 :
1403 : /* find last entry before the 'offset' */
1404 : entry = prev;
1405 127706 : if (entry->offset > offset) {
1406 78320 : n = rb_prev(&entry->offset_index);
1407 78320 : if (n) {
1408 : entry = rb_entry(n, struct btrfs_free_space,
1409 : offset_index);
1410 : ASSERT(entry->offset <= offset);
1411 : } else {
1412 67972 : if (fuzzy)
1413 : return entry;
1414 : else
1415 : return NULL;
1416 : }
1417 : }
1418 :
1419 59734 : if (entry->bitmap) {
1420 17952 : n = rb_prev(&entry->offset_index);
1421 17952 : if (n) {
1422 : prev = rb_entry(n, struct btrfs_free_space,
1423 : offset_index);
1424 18326 : if (!prev->bitmap &&
1425 850 : prev->offset + prev->bytes > offset)
1426 : return prev;
1427 : }
1428 17952 : if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1429 : return entry;
1430 41782 : } else if (entry->offset + entry->bytes > offset)
1431 : return entry;
1432 :
1433 55343 : if (!fuzzy)
1434 : return NULL;
1435 :
1436 : while (1) {
1437 3692 : if (entry->bitmap) {
1438 36 : if (entry->offset + BITS_PER_BITMAP *
1439 18 : ctl->unit > offset)
1440 : break;
1441 : } else {
1442 3674 : if (entry->offset + entry->bytes > offset)
1443 : break;
1444 : }
1445 :
1446 1846 : n = rb_next(&entry->offset_index);
1447 1846 : if (!n)
1448 : return NULL;
1449 : entry = rb_entry(n, struct btrfs_free_space, offset_index);
1450 : }
1451 : return entry;
1452 : }
1453 :
1454 : static inline void
1455 : __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1456 : struct btrfs_free_space *info)
1457 : {
1458 77843 : rb_erase(&info->offset_index, &ctl->free_space_offset);
1459 77843 : ctl->free_extents--;
1460 : }
1461 :
1462 : static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1463 : struct btrfs_free_space *info)
1464 : {
1465 : __unlink_free_space(ctl, info);
1466 77571 : ctl->free_space -= info->bytes;
1467 : }
1468 :
1469 78165 : static int link_free_space(struct btrfs_free_space_ctl *ctl,
1470 : struct btrfs_free_space *info)
1471 : {
1472 : int ret = 0;
1473 :
1474 : ASSERT(info->bytes || info->bitmap);
1475 78165 : ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1476 78165 : &info->offset_index, (info->bitmap != NULL));
1477 78165 : if (ret)
1478 : return ret;
1479 :
1480 78165 : ctl->free_space += info->bytes;
1481 78165 : ctl->free_extents++;
1482 78165 : return ret;
1483 : }
1484 :
1485 96 : static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1486 : {
1487 96 : struct btrfs_block_group_cache *block_group = ctl->private;
1488 : u64 max_bytes;
1489 : u64 bitmap_bytes;
1490 : u64 extent_bytes;
1491 96 : u64 size = block_group->key.offset;
1492 : u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1493 : int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1494 :
1495 : max_bitmaps = max(max_bitmaps, 1);
1496 :
1497 : ASSERT(ctl->total_bitmaps <= max_bitmaps);
1498 :
1499 : /*
1500 : * The goal is to keep the total amount of memory used per 1gb of space
1501 : * at or below 32k, so we need to adjust how much memory we allow to be
1502 : * used by extent based free space tracking
1503 : */
1504 96 : if (size < 1024 * 1024 * 1024)
1505 : max_bytes = MAX_CACHE_BYTES_PER_GIG;
1506 : else
1507 96 : max_bytes = MAX_CACHE_BYTES_PER_GIG *
1508 : div64_u64(size, 1024 * 1024 * 1024);
1509 :
1510 : /*
1511 : * we want to account for 1 more bitmap than what we have so we can make
1512 : * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1513 : * we add more bitmaps.
1514 : */
1515 96 : bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE;
1516 :
1517 96 : if (bitmap_bytes >= max_bytes) {
1518 12 : ctl->extents_thresh = 0;
1519 108 : return;
1520 : }
1521 :
1522 : /*
1523 : * we want the extent entry threshold to always be at most 1/2 the maxw
1524 : * bytes we can have, or whatever is less than that.
1525 : */
1526 84 : extent_bytes = max_bytes - bitmap_bytes;
1527 84 : extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
1528 :
1529 84 : ctl->extents_thresh =
1530 : div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
1531 : }
1532 :
1533 : static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1534 : struct btrfs_free_space *info,
1535 : u64 offset, u64 bytes)
1536 : {
1537 : unsigned long start, count;
1538 :
1539 22067 : start = offset_to_bit(info->offset, ctl->unit, offset);
1540 : count = bytes_to_bits(bytes, ctl->unit);
1541 : ASSERT(start + count <= BITS_PER_BITMAP);
1542 :
1543 22067 : bitmap_clear(info->bitmap, start, count);
1544 :
1545 22067 : info->bytes -= bytes;
1546 : }
1547 :
1548 5074 : static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1549 : struct btrfs_free_space *info, u64 offset,
1550 : u64 bytes)
1551 : {
1552 : __bitmap_clear_bits(ctl, info, offset, bytes);
1553 5074 : ctl->free_space -= bytes;
1554 5074 : }
1555 :
1556 12494 : static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1557 : struct btrfs_free_space *info, u64 offset,
1558 : u64 bytes)
1559 : {
1560 : unsigned long start, count;
1561 :
1562 12494 : start = offset_to_bit(info->offset, ctl->unit, offset);
1563 : count = bytes_to_bits(bytes, ctl->unit);
1564 : ASSERT(start + count <= BITS_PER_BITMAP);
1565 :
1566 12494 : bitmap_set(info->bitmap, start, count);
1567 :
1568 12494 : info->bytes += bytes;
1569 12494 : ctl->free_space += bytes;
1570 12494 : }
1571 :
1572 : /*
1573 : * If we can not find suitable extent, we will use bytes to record
1574 : * the size of the max extent.
1575 : */
1576 24237 : static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1577 : struct btrfs_free_space *bitmap_info, u64 *offset,
1578 : u64 *bytes)
1579 : {
1580 : unsigned long found_bits = 0;
1581 : unsigned long max_bits = 0;
1582 : unsigned long bits, i;
1583 : unsigned long next_zero;
1584 : unsigned long extent_bits;
1585 :
1586 24237 : i = offset_to_bit(bitmap_info->offset, ctl->unit,
1587 24237 : max_t(u64, *offset, bitmap_info->offset));
1588 24237 : bits = bytes_to_bits(*bytes, ctl->unit);
1589 :
1590 145153 : for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1591 142983 : next_zero = find_next_zero_bit(bitmap_info->bitmap,
1592 : BITS_PER_BITMAP, i);
1593 142983 : extent_bits = next_zero - i;
1594 142983 : if (extent_bits >= bits) {
1595 : found_bits = extent_bits;
1596 : break;
1597 120916 : } else if (extent_bits > max_bits) {
1598 : max_bits = extent_bits;
1599 : }
1600 : i = next_zero;
1601 : }
1602 :
1603 24237 : if (found_bits) {
1604 22067 : *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1605 22067 : *bytes = (u64)(found_bits) * ctl->unit;
1606 : return 0;
1607 : }
1608 :
1609 2170 : *bytes = (u64)(max_bits) * ctl->unit;
1610 : return -1;
1611 : }
1612 :
1613 : /* Cache the size of the max extent in bytes */
1614 : static struct btrfs_free_space *
1615 145049 : find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1616 : unsigned long align, u64 *max_extent_size)
1617 : {
1618 : struct btrfs_free_space *entry;
1619 : struct rb_node *node;
1620 : u64 tmp;
1621 : u64 align_off;
1622 : int ret;
1623 :
1624 72624 : if (!ctl->free_space_offset.rb_node)
1625 : goto out;
1626 :
1627 144850 : entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1628 72425 : if (!entry)
1629 : goto out;
1630 :
1631 186674 : for (node = &entry->offset_index; node; node = rb_next(node)) {
1632 : entry = rb_entry(node, struct btrfs_free_space, offset_index);
1633 185820 : if (entry->bytes < *bytes) {
1634 112081 : if (entry->bytes > *max_extent_size)
1635 16295 : *max_extent_size = entry->bytes;
1636 112081 : continue;
1637 : }
1638 :
1639 : /* make sure the space returned is big enough
1640 : * to match our requested alignment
1641 : */
1642 73739 : if (*bytes >= align) {
1643 73739 : tmp = entry->offset - ctl->start + align - 1;
1644 73739 : do_div(tmp, align);
1645 73739 : tmp = tmp * align + ctl->start;
1646 73739 : align_off = tmp - entry->offset;
1647 : } else {
1648 : align_off = 0;
1649 0 : tmp = entry->offset;
1650 : }
1651 :
1652 73739 : if (entry->bytes < *bytes + align_off) {
1653 0 : if (entry->bytes > *max_extent_size)
1654 0 : *max_extent_size = entry->bytes;
1655 0 : continue;
1656 : }
1657 :
1658 73739 : if (entry->bitmap) {
1659 7242 : u64 size = *bytes;
1660 :
1661 7242 : ret = search_bitmap(ctl, entry, &tmp, &size);
1662 7242 : if (!ret) {
1663 5074 : *offset = tmp;
1664 5074 : *bytes = size;
1665 5074 : return entry;
1666 2168 : } else if (size > *max_extent_size) {
1667 500 : *max_extent_size = size;
1668 : }
1669 2168 : continue;
1670 : }
1671 :
1672 66497 : *offset = tmp;
1673 66497 : *bytes = entry->bytes - align_off;
1674 66497 : return entry;
1675 : }
1676 : out:
1677 : return NULL;
1678 : }
1679 :
1680 47 : static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1681 : struct btrfs_free_space *info, u64 offset)
1682 : {
1683 47 : info->offset = offset_to_bitmap(ctl, offset);
1684 47 : info->bytes = 0;
1685 47 : INIT_LIST_HEAD(&info->list);
1686 47 : link_free_space(ctl, info);
1687 47 : ctl->total_bitmaps++;
1688 :
1689 47 : ctl->op->recalc_thresholds(ctl);
1690 47 : }
1691 :
1692 48 : static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1693 : struct btrfs_free_space *bitmap_info)
1694 : {
1695 : unlink_free_space(ctl, bitmap_info);
1696 48 : kfree(bitmap_info->bitmap);
1697 48 : kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1698 48 : ctl->total_bitmaps--;
1699 48 : ctl->op->recalc_thresholds(ctl);
1700 48 : }
1701 :
1702 0 : static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1703 : struct btrfs_free_space *bitmap_info,
1704 : u64 *offset, u64 *bytes)
1705 : {
1706 : u64 end;
1707 : u64 search_start, search_bytes;
1708 : int ret;
1709 :
1710 : again:
1711 0 : end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1712 :
1713 : /*
1714 : * We need to search for bits in this bitmap. We could only cover some
1715 : * of the extent in this bitmap thanks to how we add space, so we need
1716 : * to search for as much as it as we can and clear that amount, and then
1717 : * go searching for the next bit.
1718 : */
1719 0 : search_start = *offset;
1720 0 : search_bytes = ctl->unit;
1721 0 : search_bytes = min(search_bytes, end - search_start + 1);
1722 0 : ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes);
1723 0 : if (ret < 0 || search_start != *offset)
1724 : return -EINVAL;
1725 :
1726 : /* We may have found more bits than what we need */
1727 0 : search_bytes = min(search_bytes, *bytes);
1728 :
1729 : /* Cannot clear past the end of the bitmap */
1730 0 : search_bytes = min(search_bytes, end - search_start + 1);
1731 :
1732 0 : bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1733 0 : *offset += search_bytes;
1734 0 : *bytes -= search_bytes;
1735 :
1736 0 : if (*bytes) {
1737 0 : struct rb_node *next = rb_next(&bitmap_info->offset_index);
1738 0 : if (!bitmap_info->bytes)
1739 0 : free_bitmap(ctl, bitmap_info);
1740 :
1741 : /*
1742 : * no entry after this bitmap, but we still have bytes to
1743 : * remove, so something has gone wrong.
1744 : */
1745 0 : if (!next)
1746 : return -EINVAL;
1747 :
1748 : bitmap_info = rb_entry(next, struct btrfs_free_space,
1749 : offset_index);
1750 :
1751 : /*
1752 : * if the next entry isn't a bitmap we need to return to let the
1753 : * extent stuff do its work.
1754 : */
1755 0 : if (!bitmap_info->bitmap)
1756 : return -EAGAIN;
1757 :
1758 : /*
1759 : * Ok the next item is a bitmap, but it may not actually hold
1760 : * the information for the rest of this free space stuff, so
1761 : * look for it, and if we don't find it return so we can try
1762 : * everything over again.
1763 : */
1764 0 : search_start = *offset;
1765 0 : search_bytes = ctl->unit;
1766 0 : ret = search_bitmap(ctl, bitmap_info, &search_start,
1767 : &search_bytes);
1768 0 : if (ret < 0 || search_start != *offset)
1769 : return -EAGAIN;
1770 :
1771 : goto again;
1772 0 : } else if (!bitmap_info->bytes)
1773 0 : free_bitmap(ctl, bitmap_info);
1774 :
1775 : return 0;
1776 : }
1777 :
1778 : static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1779 : struct btrfs_free_space *info, u64 offset,
1780 : u64 bytes)
1781 : {
1782 : u64 bytes_to_set = 0;
1783 : u64 end;
1784 :
1785 12494 : end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1786 :
1787 12494 : bytes_to_set = min(end - offset, bytes);
1788 :
1789 12494 : bitmap_set_bits(ctl, info, offset, bytes_to_set);
1790 :
1791 : return bytes_to_set;
1792 :
1793 : }
1794 :
1795 29659 : static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1796 : struct btrfs_free_space *info)
1797 : {
1798 29659 : struct btrfs_block_group_cache *block_group = ctl->private;
1799 :
1800 : /*
1801 : * If we are below the extents threshold then we can add this as an
1802 : * extent, and don't have to deal with the bitmap
1803 : */
1804 29659 : if (ctl->free_extents < ctl->extents_thresh) {
1805 : /*
1806 : * If this block group has some small extents we don't want to
1807 : * use up all of our free slots in the cache with them, we want
1808 : * to reserve them to larger extents, however if we have plent
1809 : * of cache left then go ahead an dadd them, no sense in adding
1810 : * the overhead of a bitmap if we don't have to.
1811 : */
1812 19167 : if (info->bytes <= block_group->sectorsize * 4) {
1813 14564 : if (ctl->free_extents * 2 <= ctl->extents_thresh)
1814 : return false;
1815 : } else {
1816 : return false;
1817 : }
1818 : }
1819 :
1820 : /*
1821 : * The original block groups from mkfs can be really small, like 8
1822 : * megabytes, so don't bother with a bitmap for those entries. However
1823 : * some block groups can be smaller than what a bitmap would cover but
1824 : * are still large enough that they could overflow the 32k memory limit,
1825 : * so allow those block groups to still be allowed to have a bitmap
1826 : * entry.
1827 : */
1828 12618 : if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
1829 : return false;
1830 :
1831 12493 : return true;
1832 : }
1833 :
1834 : static struct btrfs_free_space_op free_space_op = {
1835 : .recalc_thresholds = recalculate_thresholds,
1836 : .use_bitmap = use_bitmap,
1837 : };
1838 :
1839 47582 : static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
1840 : struct btrfs_free_space *info)
1841 : {
1842 : struct btrfs_free_space *bitmap_info;
1843 : struct btrfs_block_group_cache *block_group = NULL;
1844 : int added = 0;
1845 : u64 bytes, offset, bytes_added;
1846 : int ret;
1847 :
1848 29659 : bytes = info->bytes;
1849 29659 : offset = info->offset;
1850 :
1851 29659 : if (!ctl->op->use_bitmap(ctl, info))
1852 : return 0;
1853 :
1854 12493 : if (ctl->op == &free_space_op)
1855 12493 : block_group = ctl->private;
1856 : again:
1857 : /*
1858 : * Since we link bitmaps right into the cluster we need to see if we
1859 : * have a cluster here, and if so and it has our bitmap we need to add
1860 : * the free space to that bitmap.
1861 : */
1862 25176 : if (block_group && !list_empty(&block_group->cluster_list)) {
1863 : struct btrfs_free_cluster *cluster;
1864 : struct rb_node *node;
1865 : struct btrfs_free_space *entry;
1866 :
1867 : cluster = list_entry(block_group->cluster_list.next,
1868 : struct btrfs_free_cluster,
1869 : block_group_list);
1870 : spin_lock(&cluster->lock);
1871 8379 : node = rb_first(&cluster->root);
1872 8379 : if (!node) {
1873 : spin_unlock(&cluster->lock);
1874 : goto no_cluster_bitmap;
1875 : }
1876 :
1877 : entry = rb_entry(node, struct btrfs_free_space, offset_index);
1878 8379 : if (!entry->bitmap) {
1879 : spin_unlock(&cluster->lock);
1880 : goto no_cluster_bitmap;
1881 : }
1882 :
1883 16758 : if (entry->offset == offset_to_bitmap(ctl, offset)) {
1884 : bytes_added = add_bytes_to_bitmap(ctl, entry,
1885 : offset, bytes);
1886 7816 : bytes -= bytes_added;
1887 7816 : offset += bytes_added;
1888 : }
1889 : spin_unlock(&cluster->lock);
1890 8379 : if (!bytes) {
1891 : ret = 1;
1892 : goto out;
1893 : }
1894 : }
1895 :
1896 : no_cluster_bitmap:
1897 4772 : bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1898 : 1, 0);
1899 4772 : if (!bitmap_info) {
1900 : ASSERT(added == 0);
1901 : goto new_bitmap;
1902 : }
1903 :
1904 : bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
1905 4678 : bytes -= bytes_added;
1906 4678 : offset += bytes_added;
1907 : added = 0;
1908 :
1909 4678 : if (!bytes) {
1910 : ret = 1;
1911 : goto out;
1912 : } else
1913 : goto again;
1914 :
1915 : new_bitmap:
1916 94 : if (info && info->bitmap) {
1917 47 : add_new_bitmap(ctl, info, offset);
1918 : added = 1;
1919 : info = NULL;
1920 47 : goto again;
1921 : } else {
1922 : spin_unlock(&ctl->tree_lock);
1923 :
1924 : /* no pre-allocated info, allocate a new one */
1925 47 : if (!info) {
1926 0 : info = kmem_cache_zalloc(btrfs_free_space_cachep,
1927 : GFP_NOFS);
1928 0 : if (!info) {
1929 : spin_lock(&ctl->tree_lock);
1930 : ret = -ENOMEM;
1931 0 : goto out;
1932 : }
1933 : }
1934 :
1935 : /* allocate the bitmap */
1936 47 : info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
1937 : spin_lock(&ctl->tree_lock);
1938 47 : if (!info->bitmap) {
1939 : ret = -ENOMEM;
1940 : goto out;
1941 : }
1942 : goto again;
1943 : }
1944 :
1945 : out:
1946 12493 : if (info) {
1947 12446 : if (info->bitmap)
1948 0 : kfree(info->bitmap);
1949 12446 : kmem_cache_free(btrfs_free_space_cachep, info);
1950 : }
1951 :
1952 12493 : return ret;
1953 : }
1954 :
1955 102648 : static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
1956 : struct btrfs_free_space *info, bool update_stat)
1957 : {
1958 : struct btrfs_free_space *left_info;
1959 : struct btrfs_free_space *right_info;
1960 : bool merged = false;
1961 35745 : u64 offset = info->offset;
1962 35745 : u64 bytes = info->bytes;
1963 :
1964 : /*
1965 : * first we want to see if there is free space adjacent to the range we
1966 : * are adding, if there is remove that struct and add a new one to
1967 : * cover the entire range
1968 : */
1969 71490 : right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
1970 35745 : if (right_info && rb_prev(&right_info->offset_index))
1971 4587 : left_info = rb_entry(rb_prev(&right_info->offset_index),
1972 : struct btrfs_free_space, offset_index);
1973 : else
1974 62316 : left_info = tree_search_offset(ctl, offset - 1, 0, 0);
1975 :
1976 35745 : if (right_info && !right_info->bitmap) {
1977 3230 : if (update_stat)
1978 : unlink_free_space(ctl, right_info);
1979 : else
1980 : __unlink_free_space(ctl, right_info);
1981 3230 : info->bytes += right_info->bytes;
1982 3230 : kmem_cache_free(btrfs_free_space_cachep, right_info);
1983 : merged = true;
1984 : }
1985 :
1986 41410 : if (left_info && !left_info->bitmap &&
1987 5665 : left_info->offset + left_info->bytes == offset) {
1988 3730 : if (update_stat)
1989 : unlink_free_space(ctl, left_info);
1990 : else
1991 : __unlink_free_space(ctl, left_info);
1992 3730 : info->offset = left_info->offset;
1993 3730 : info->bytes += left_info->bytes;
1994 3730 : kmem_cache_free(btrfs_free_space_cachep, left_info);
1995 : merged = true;
1996 : }
1997 :
1998 35745 : return merged;
1999 : }
2000 :
2001 34710 : int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl,
2002 : u64 offset, u64 bytes)
2003 : {
2004 : struct btrfs_free_space *info;
2005 : int ret = 0;
2006 :
2007 34710 : info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2008 34710 : if (!info)
2009 : return -ENOMEM;
2010 :
2011 34710 : info->offset = offset;
2012 34710 : info->bytes = bytes;
2013 :
2014 : spin_lock(&ctl->tree_lock);
2015 :
2016 34710 : if (try_merge_free_space(ctl, info, true))
2017 : goto link;
2018 :
2019 : /*
2020 : * There was no extent directly to the left or right of this new
2021 : * extent then we know we're going to have to allocate a new extent, so
2022 : * before we do that see if we need to drop this into a bitmap
2023 : */
2024 29659 : ret = insert_into_bitmap(ctl, info);
2025 29659 : if (ret < 0) {
2026 : goto out;
2027 29659 : } else if (ret) {
2028 : ret = 0;
2029 : goto out;
2030 : }
2031 : link:
2032 22217 : ret = link_free_space(ctl, info);
2033 22217 : if (ret)
2034 0 : kmem_cache_free(btrfs_free_space_cachep, info);
2035 : out:
2036 : spin_unlock(&ctl->tree_lock);
2037 :
2038 34710 : if (ret) {
2039 0 : printk(KERN_CRIT "BTRFS: unable to add free space :%d\n", ret);
2040 : ASSERT(ret != -EEXIST);
2041 : }
2042 :
2043 34710 : return ret;
2044 : }
2045 :
2046 0 : int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2047 : u64 offset, u64 bytes)
2048 : {
2049 0 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2050 : struct btrfs_free_space *info;
2051 : int ret;
2052 : bool re_search = false;
2053 :
2054 : spin_lock(&ctl->tree_lock);
2055 :
2056 : again:
2057 : ret = 0;
2058 0 : if (!bytes)
2059 : goto out_lock;
2060 :
2061 0 : info = tree_search_offset(ctl, offset, 0, 0);
2062 0 : if (!info) {
2063 : /*
2064 : * oops didn't find an extent that matched the space we wanted
2065 : * to remove, look for a bitmap instead
2066 : */
2067 0 : info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2068 : 1, 0);
2069 0 : if (!info) {
2070 : /*
2071 : * If we found a partial bit of our free space in a
2072 : * bitmap but then couldn't find the other part this may
2073 : * be a problem, so WARN about it.
2074 : */
2075 0 : WARN_ON(re_search);
2076 : goto out_lock;
2077 : }
2078 : }
2079 :
2080 : re_search = false;
2081 0 : if (!info->bitmap) {
2082 : unlink_free_space(ctl, info);
2083 0 : if (offset == info->offset) {
2084 0 : u64 to_free = min(bytes, info->bytes);
2085 :
2086 0 : info->bytes -= to_free;
2087 0 : info->offset += to_free;
2088 0 : if (info->bytes) {
2089 0 : ret = link_free_space(ctl, info);
2090 0 : WARN_ON(ret);
2091 : } else {
2092 0 : kmem_cache_free(btrfs_free_space_cachep, info);
2093 : }
2094 :
2095 0 : offset += to_free;
2096 0 : bytes -= to_free;
2097 0 : goto again;
2098 : } else {
2099 0 : u64 old_end = info->bytes + info->offset;
2100 :
2101 0 : info->bytes = offset - info->offset;
2102 0 : ret = link_free_space(ctl, info);
2103 0 : WARN_ON(ret);
2104 0 : if (ret)
2105 : goto out_lock;
2106 :
2107 : /* Not enough bytes in this entry to satisfy us */
2108 0 : if (old_end < offset + bytes) {
2109 0 : bytes -= old_end - offset;
2110 0 : offset = old_end;
2111 0 : goto again;
2112 0 : } else if (old_end == offset + bytes) {
2113 : /* all done */
2114 : goto out_lock;
2115 : }
2116 : spin_unlock(&ctl->tree_lock);
2117 :
2118 0 : ret = btrfs_add_free_space(block_group, offset + bytes,
2119 0 : old_end - (offset + bytes));
2120 0 : WARN_ON(ret);
2121 : goto out;
2122 : }
2123 : }
2124 :
2125 0 : ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2126 0 : if (ret == -EAGAIN) {
2127 : re_search = true;
2128 : goto again;
2129 : }
2130 : out_lock:
2131 : spin_unlock(&ctl->tree_lock);
2132 : out:
2133 0 : return ret;
2134 : }
2135 :
2136 0 : void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2137 : u64 bytes)
2138 : {
2139 0 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2140 : struct btrfs_free_space *info;
2141 : struct rb_node *n;
2142 : int count = 0;
2143 :
2144 0 : for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2145 : info = rb_entry(n, struct btrfs_free_space, offset_index);
2146 0 : if (info->bytes >= bytes && !block_group->ro)
2147 0 : count++;
2148 0 : btrfs_crit(block_group->fs_info,
2149 : "entry offset %llu, bytes %llu, bitmap %s",
2150 : info->offset, info->bytes,
2151 : (info->bitmap) ? "yes" : "no");
2152 : }
2153 0 : btrfs_info(block_group->fs_info, "block group has cluster?: %s",
2154 : list_empty(&block_group->cluster_list) ? "no" : "yes");
2155 0 : btrfs_info(block_group->fs_info,
2156 : "%d blocks of free space at or bigger than bytes is", count);
2157 0 : }
2158 :
2159 1228 : void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2160 : {
2161 1228 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2162 :
2163 1228 : spin_lock_init(&ctl->tree_lock);
2164 1228 : ctl->unit = block_group->sectorsize;
2165 1228 : ctl->start = block_group->key.objectid;
2166 1228 : ctl->private = block_group;
2167 1228 : ctl->op = &free_space_op;
2168 :
2169 : /*
2170 : * we only want to have 32k of ram per block group for keeping
2171 : * track of free space, and if we pass 1/2 of that we want to
2172 : * start converting things over to using bitmaps
2173 : */
2174 1228 : ctl->extents_thresh = ((1024 * 32) / 2) /
2175 : sizeof(struct btrfs_free_space);
2176 1228 : }
2177 :
2178 : /*
2179 : * for a given cluster, put all of its extents back into the free
2180 : * space cache. If the block group passed doesn't match the block group
2181 : * pointed to by the cluster, someone else raced in and freed the
2182 : * cluster already. In that case, we just return without changing anything
2183 : */
2184 : static int
2185 217 : __btrfs_return_cluster_to_free_space(
2186 : struct btrfs_block_group_cache *block_group,
2187 : struct btrfs_free_cluster *cluster)
2188 : {
2189 217 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2190 : struct btrfs_free_space *entry;
2191 : struct rb_node *node;
2192 :
2193 : spin_lock(&cluster->lock);
2194 217 : if (cluster->block_group != block_group)
2195 : goto out;
2196 :
2197 217 : cluster->block_group = NULL;
2198 217 : cluster->window_start = 0;
2199 217 : list_del_init(&cluster->block_group_list);
2200 :
2201 217 : node = rb_first(&cluster->root);
2202 1471 : while (node) {
2203 : bool bitmap;
2204 :
2205 : entry = rb_entry(node, struct btrfs_free_space, offset_index);
2206 1037 : node = rb_next(&entry->offset_index);
2207 1037 : rb_erase(&entry->offset_index, &cluster->root);
2208 :
2209 1037 : bitmap = (entry->bitmap != NULL);
2210 1037 : if (!bitmap)
2211 1035 : try_merge_free_space(ctl, entry, false);
2212 1037 : tree_insert_offset(&ctl->free_space_offset,
2213 : entry->offset, &entry->offset_index, bitmap);
2214 : }
2215 217 : cluster->root = RB_ROOT;
2216 :
2217 : out:
2218 : spin_unlock(&cluster->lock);
2219 217 : btrfs_put_block_group(block_group);
2220 217 : return 0;
2221 : }
2222 :
2223 2604 : static void __btrfs_remove_free_space_cache_locked(
2224 : struct btrfs_free_space_ctl *ctl)
2225 : {
2226 : struct btrfs_free_space *info;
2227 : struct rb_node *node;
2228 :
2229 9068 : while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2230 : info = rb_entry(node, struct btrfs_free_space, offset_index);
2231 3860 : if (!info->bitmap) {
2232 : unlink_free_space(ctl, info);
2233 3858 : kmem_cache_free(btrfs_free_space_cachep, info);
2234 : } else {
2235 2 : free_bitmap(ctl, info);
2236 : }
2237 3860 : if (need_resched()) {
2238 : spin_unlock(&ctl->tree_lock);
2239 1 : cond_resched();
2240 : spin_lock(&ctl->tree_lock);
2241 : }
2242 : }
2243 2604 : }
2244 :
2245 1376 : void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2246 : {
2247 : spin_lock(&ctl->tree_lock);
2248 1376 : __btrfs_remove_free_space_cache_locked(ctl);
2249 : spin_unlock(&ctl->tree_lock);
2250 1376 : }
2251 :
2252 1228 : void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2253 : {
2254 1228 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2255 : struct btrfs_free_cluster *cluster;
2256 : struct list_head *head;
2257 :
2258 : spin_lock(&ctl->tree_lock);
2259 2832 : while ((head = block_group->cluster_list.next) !=
2260 1416 : &block_group->cluster_list) {
2261 188 : cluster = list_entry(head, struct btrfs_free_cluster,
2262 : block_group_list);
2263 :
2264 188 : WARN_ON(cluster->block_group != block_group);
2265 188 : __btrfs_return_cluster_to_free_space(block_group, cluster);
2266 188 : if (need_resched()) {
2267 : spin_unlock(&ctl->tree_lock);
2268 0 : cond_resched();
2269 : spin_lock(&ctl->tree_lock);
2270 : }
2271 : }
2272 1228 : __btrfs_remove_free_space_cache_locked(ctl);
2273 : spin_unlock(&ctl->tree_lock);
2274 :
2275 1228 : }
2276 :
2277 72621 : u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2278 : u64 offset, u64 bytes, u64 empty_size,
2279 : u64 *max_extent_size)
2280 : {
2281 72621 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2282 : struct btrfs_free_space *entry = NULL;
2283 72621 : u64 bytes_search = bytes + empty_size;
2284 : u64 ret = 0;
2285 : u64 align_gap = 0;
2286 : u64 align_gap_len = 0;
2287 :
2288 : spin_lock(&ctl->tree_lock);
2289 72624 : entry = find_free_space(ctl, &offset, &bytes_search,
2290 : block_group->full_stripe_len, max_extent_size);
2291 72622 : if (!entry)
2292 : goto out;
2293 :
2294 71571 : ret = offset;
2295 71571 : if (entry->bitmap) {
2296 5074 : bitmap_clear_bits(ctl, entry, offset, bytes);
2297 5074 : if (!entry->bytes)
2298 46 : free_bitmap(ctl, entry);
2299 : } else {
2300 : unlink_free_space(ctl, entry);
2301 66497 : align_gap_len = offset - entry->offset;
2302 : align_gap = entry->offset;
2303 :
2304 66497 : entry->offset = offset + bytes;
2305 66497 : WARN_ON(entry->bytes < bytes + align_gap_len);
2306 :
2307 66498 : entry->bytes -= bytes + align_gap_len;
2308 66498 : if (!entry->bytes)
2309 12451 : kmem_cache_free(btrfs_free_space_cachep, entry);
2310 : else
2311 54047 : link_free_space(ctl, entry);
2312 : }
2313 : out:
2314 : spin_unlock(&ctl->tree_lock);
2315 :
2316 72625 : if (align_gap_len)
2317 0 : __btrfs_add_free_space(ctl, align_gap, align_gap_len);
2318 72625 : return ret;
2319 : }
2320 :
2321 : /*
2322 : * given a cluster, put all of its extents back into the free space
2323 : * cache. If a block group is passed, this function will only free
2324 : * a cluster that belongs to the passed block group.
2325 : *
2326 : * Otherwise, it'll get a reference on the block group pointed to by the
2327 : * cluster and remove the cluster from it.
2328 : */
2329 274 : int btrfs_return_cluster_to_free_space(
2330 : struct btrfs_block_group_cache *block_group,
2331 : struct btrfs_free_cluster *cluster)
2332 : {
2333 : struct btrfs_free_space_ctl *ctl;
2334 : int ret;
2335 :
2336 : /* first, get a safe pointer to the block group */
2337 : spin_lock(&cluster->lock);
2338 274 : if (!block_group) {
2339 130 : block_group = cluster->block_group;
2340 130 : if (!block_group) {
2341 : spin_unlock(&cluster->lock);
2342 101 : return 0;
2343 : }
2344 144 : } else if (cluster->block_group != block_group) {
2345 : /* someone else has already freed it don't redo their work */
2346 : spin_unlock(&cluster->lock);
2347 144 : return 0;
2348 : }
2349 29 : atomic_inc(&block_group->count);
2350 : spin_unlock(&cluster->lock);
2351 :
2352 29 : ctl = block_group->free_space_ctl;
2353 :
2354 : /* now return any extents the cluster had on it */
2355 : spin_lock(&ctl->tree_lock);
2356 29 : ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2357 : spin_unlock(&ctl->tree_lock);
2358 :
2359 : /* finally drop our ref */
2360 29 : btrfs_put_block_group(block_group);
2361 29 : return ret;
2362 : }
2363 :
2364 16995 : static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2365 : struct btrfs_free_cluster *cluster,
2366 : struct btrfs_free_space *entry,
2367 : u64 bytes, u64 min_start,
2368 : u64 *max_extent_size)
2369 : {
2370 33988 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2371 : int err;
2372 16995 : u64 search_start = cluster->window_start;
2373 16995 : u64 search_bytes = bytes;
2374 : u64 ret = 0;
2375 :
2376 16995 : search_start = min_start;
2377 : search_bytes = bytes;
2378 :
2379 16995 : err = search_bitmap(ctl, entry, &search_start, &search_bytes);
2380 16995 : if (err) {
2381 2 : if (search_bytes > *max_extent_size)
2382 0 : *max_extent_size = search_bytes;
2383 : return 0;
2384 : }
2385 :
2386 16993 : ret = search_start;
2387 : __bitmap_clear_bits(ctl, entry, ret, bytes);
2388 :
2389 : return ret;
2390 : }
2391 :
2392 : /*
2393 : * given a cluster, try to allocate 'bytes' from it, returns 0
2394 : * if it couldn't find anything suitably large, or a logical disk offset
2395 : * if things worked out
2396 : */
2397 57691 : u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2398 : struct btrfs_free_cluster *cluster, u64 bytes,
2399 : u64 min_start, u64 *max_extent_size)
2400 : {
2401 40696 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2402 : struct btrfs_free_space *entry = NULL;
2403 : struct rb_node *node;
2404 : u64 ret = 0;
2405 :
2406 : spin_lock(&cluster->lock);
2407 40696 : if (bytes > cluster->max_size)
2408 : goto out;
2409 :
2410 40696 : if (cluster->block_group != block_group)
2411 : goto out;
2412 :
2413 40696 : node = rb_first(&cluster->root);
2414 40695 : if (!node)
2415 : goto out;
2416 :
2417 : entry = rb_entry(node, struct btrfs_free_space, offset_index);
2418 : while (1) {
2419 40695 : if (entry->bytes < bytes && entry->bytes > *max_extent_size)
2420 0 : *max_extent_size = entry->bytes;
2421 :
2422 81391 : if (entry->bytes < bytes ||
2423 64397 : (!entry->bitmap && entry->offset < min_start)) {
2424 0 : node = rb_next(&entry->offset_index);
2425 0 : if (!node)
2426 : break;
2427 : entry = rb_entry(node, struct btrfs_free_space,
2428 : offset_index);
2429 0 : continue;
2430 : }
2431 :
2432 40696 : if (entry->bitmap) {
2433 33990 : ret = btrfs_alloc_from_bitmap(block_group,
2434 : cluster, entry, bytes,
2435 : cluster->window_start,
2436 : max_extent_size);
2437 16995 : if (ret == 0) {
2438 2 : node = rb_next(&entry->offset_index);
2439 2 : if (!node)
2440 : break;
2441 : entry = rb_entry(node, struct btrfs_free_space,
2442 : offset_index);
2443 0 : continue;
2444 : }
2445 16993 : cluster->window_start += bytes;
2446 : } else {
2447 23701 : ret = entry->offset;
2448 :
2449 23701 : entry->offset += bytes;
2450 23701 : entry->bytes -= bytes;
2451 : }
2452 :
2453 40694 : if (entry->bytes == 0)
2454 247 : rb_erase(&entry->offset_index, &cluster->root);
2455 : break;
2456 : }
2457 : out:
2458 : spin_unlock(&cluster->lock);
2459 :
2460 40696 : if (!ret)
2461 : return 0;
2462 :
2463 : spin_lock(&ctl->tree_lock);
2464 :
2465 40694 : ctl->free_space -= bytes;
2466 40694 : if (entry->bytes == 0) {
2467 247 : ctl->free_extents--;
2468 247 : if (entry->bitmap) {
2469 0 : kfree(entry->bitmap);
2470 0 : ctl->total_bitmaps--;
2471 0 : ctl->op->recalc_thresholds(ctl);
2472 : }
2473 247 : kmem_cache_free(btrfs_free_space_cachep, entry);
2474 : }
2475 :
2476 : spin_unlock(&ctl->tree_lock);
2477 :
2478 40694 : return ret;
2479 : }
2480 :
2481 4 : static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2482 : struct btrfs_free_space *entry,
2483 : struct btrfs_free_cluster *cluster,
2484 : u64 offset, u64 bytes,
2485 : u64 cont1_bytes, u64 min_bytes)
2486 : {
2487 4 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2488 : unsigned long next_zero;
2489 : unsigned long i;
2490 : unsigned long want_bits;
2491 : unsigned long min_bits;
2492 : unsigned long found_bits;
2493 : unsigned long start = 0;
2494 : unsigned long total_found = 0;
2495 : int ret;
2496 :
2497 4 : i = offset_to_bit(entry->offset, ctl->unit,
2498 4 : max_t(u64, offset, entry->offset));
2499 : want_bits = bytes_to_bits(bytes, ctl->unit);
2500 : min_bits = bytes_to_bits(min_bytes, ctl->unit);
2501 :
2502 : again:
2503 : found_bits = 0;
2504 6 : for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2505 4 : next_zero = find_next_zero_bit(entry->bitmap,
2506 : BITS_PER_BITMAP, i);
2507 4 : if (next_zero - i >= min_bits) {
2508 : found_bits = next_zero - i;
2509 : break;
2510 : }
2511 : i = next_zero;
2512 : }
2513 :
2514 6 : if (!found_bits)
2515 : return -ENOSPC;
2516 :
2517 4 : if (!total_found) {
2518 : start = i;
2519 2 : cluster->max_size = 0;
2520 : }
2521 :
2522 4 : total_found += found_bits;
2523 :
2524 4 : if (cluster->max_size < found_bits * ctl->unit)
2525 3 : cluster->max_size = found_bits * ctl->unit;
2526 :
2527 4 : if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2528 2 : i = next_zero + 1;
2529 2 : goto again;
2530 : }
2531 :
2532 2 : cluster->window_start = start * ctl->unit + entry->offset;
2533 2 : rb_erase(&entry->offset_index, &ctl->free_space_offset);
2534 2 : ret = tree_insert_offset(&cluster->root, entry->offset,
2535 : &entry->offset_index, 1);
2536 : ASSERT(!ret); /* -EEXIST; Logic error */
2537 :
2538 4 : trace_btrfs_setup_cluster(block_group, cluster,
2539 4 : total_found * ctl->unit, 1);
2540 2 : return 0;
2541 : }
2542 :
2543 : /*
2544 : * This searches the block group for just extents to fill the cluster with.
2545 : * Try to find a cluster with at least bytes total bytes, at least one
2546 : * extent of cont1_bytes, and other clusters of at least min_bytes.
2547 : */
2548 : static noinline int
2549 217 : setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2550 : struct btrfs_free_cluster *cluster,
2551 : struct list_head *bitmaps, u64 offset, u64 bytes,
2552 : u64 cont1_bytes, u64 min_bytes)
2553 : {
2554 217 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2555 : struct btrfs_free_space *first = NULL;
2556 : struct btrfs_free_space *entry = NULL;
2557 : struct btrfs_free_space *last;
2558 : struct rb_node *node;
2559 : u64 window_free;
2560 : u64 max_extent;
2561 : u64 total_size = 0;
2562 :
2563 217 : entry = tree_search_offset(ctl, offset, 0, 1);
2564 217 : if (!entry)
2565 : return -ENOSPC;
2566 :
2567 : /*
2568 : * We don't want bitmaps, so just move along until we find a normal
2569 : * extent entry.
2570 : */
2571 224 : while (entry->bitmap || entry->bytes < min_bytes) {
2572 18 : if (entry->bitmap && list_empty(&entry->list))
2573 : list_add_tail(&entry->list, bitmaps);
2574 9 : node = rb_next(&entry->offset_index);
2575 9 : if (!node)
2576 : return -ENOSPC;
2577 : entry = rb_entry(node, struct btrfs_free_space, offset_index);
2578 : }
2579 :
2580 : window_free = entry->bytes;
2581 : max_extent = entry->bytes;
2582 : first = entry;
2583 : last = entry;
2584 :
2585 1497 : for (node = rb_next(&entry->offset_index); node;
2586 1067 : node = rb_next(&entry->offset_index)) {
2587 : entry = rb_entry(node, struct btrfs_free_space, offset_index);
2588 :
2589 1067 : if (entry->bitmap) {
2590 0 : if (list_empty(&entry->list))
2591 : list_add_tail(&entry->list, bitmaps);
2592 0 : continue;
2593 : }
2594 :
2595 1067 : if (entry->bytes < min_bytes)
2596 0 : continue;
2597 :
2598 : last = entry;
2599 1067 : window_free += entry->bytes;
2600 1067 : if (entry->bytes > max_extent)
2601 : max_extent = entry->bytes;
2602 : }
2603 :
2604 215 : if (window_free < bytes || max_extent < cont1_bytes)
2605 : return -ENOSPC;
2606 :
2607 215 : cluster->window_start = first->offset;
2608 :
2609 : node = &first->offset_index;
2610 :
2611 : /*
2612 : * now we've found our entries, pull them out of the free space
2613 : * cache and put them into the cluster rbtree
2614 : */
2615 : do {
2616 : int ret;
2617 :
2618 : entry = rb_entry(node, struct btrfs_free_space, offset_index);
2619 1282 : node = rb_next(&entry->offset_index);
2620 1282 : if (entry->bitmap || entry->bytes < min_bytes)
2621 0 : continue;
2622 :
2623 1282 : rb_erase(&entry->offset_index, &ctl->free_space_offset);
2624 1282 : ret = tree_insert_offset(&cluster->root, entry->offset,
2625 : &entry->offset_index, 0);
2626 1282 : total_size += entry->bytes;
2627 : ASSERT(!ret); /* -EEXIST; Logic error */
2628 1282 : } while (node && entry != last);
2629 :
2630 215 : cluster->max_size = max_extent;
2631 215 : trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2632 215 : return 0;
2633 : }
2634 :
2635 : /*
2636 : * This specifically looks for bitmaps that may work in the cluster, we assume
2637 : * that we have already failed to find extents that will work.
2638 : */
2639 : static noinline int
2640 2 : setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
2641 : struct btrfs_free_cluster *cluster,
2642 : struct list_head *bitmaps, u64 offset, u64 bytes,
2643 : u64 cont1_bytes, u64 min_bytes)
2644 : {
2645 2 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2646 : struct btrfs_free_space *entry;
2647 : int ret = -ENOSPC;
2648 : u64 bitmap_offset = offset_to_bitmap(ctl, offset);
2649 :
2650 2 : if (ctl->total_bitmaps == 0)
2651 : return -ENOSPC;
2652 :
2653 : /*
2654 : * The bitmap that covers offset won't be in the list unless offset
2655 : * is just its start offset.
2656 : */
2657 2 : entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
2658 2 : if (entry->offset != bitmap_offset) {
2659 0 : entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
2660 0 : if (entry && list_empty(&entry->list))
2661 : list_add(&entry->list, bitmaps);
2662 : }
2663 :
2664 4 : list_for_each_entry(entry, bitmaps, list) {
2665 4 : if (entry->bytes < bytes)
2666 0 : continue;
2667 4 : ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
2668 : bytes, cont1_bytes, min_bytes);
2669 4 : if (!ret)
2670 : return 0;
2671 : }
2672 :
2673 : /*
2674 : * The bitmaps list has all the bitmaps that record free space
2675 : * starting after offset, so no more search is required.
2676 : */
2677 : return -ENOSPC;
2678 : }
2679 :
2680 : /*
2681 : * here we try to find a cluster of blocks in a block group. The goal
2682 : * is to find at least bytes+empty_size.
2683 : * We might not find them all in one contiguous area.
2684 : *
2685 : * returns zero and sets up cluster if things worked out, otherwise
2686 : * it returns -enospc
2687 : */
2688 394 : int btrfs_find_space_cluster(struct btrfs_root *root,
2689 : struct btrfs_block_group_cache *block_group,
2690 : struct btrfs_free_cluster *cluster,
2691 : u64 offset, u64 bytes, u64 empty_size)
2692 : {
2693 394 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2694 : struct btrfs_free_space *entry, *tmp;
2695 394 : LIST_HEAD(bitmaps);
2696 : u64 min_bytes;
2697 : u64 cont1_bytes;
2698 : int ret;
2699 :
2700 : /*
2701 : * Choose the minimum extent size we'll require for this
2702 : * cluster. For SSD_SPREAD, don't allow any fragmentation.
2703 : * For metadata, allow allocates with smaller extents. For
2704 : * data, keep it dense.
2705 : */
2706 394 : if (btrfs_test_opt(root, SSD_SPREAD)) {
2707 0 : cont1_bytes = min_bytes = bytes + empty_size;
2708 394 : } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
2709 : cont1_bytes = bytes;
2710 394 : min_bytes = block_group->sectorsize;
2711 : } else {
2712 0 : cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
2713 0 : min_bytes = block_group->sectorsize;
2714 : }
2715 :
2716 : spin_lock(&ctl->tree_lock);
2717 :
2718 : /*
2719 : * If we know we don't have enough space to make a cluster don't even
2720 : * bother doing all the work to try and find one.
2721 : */
2722 394 : if (ctl->free_space < bytes) {
2723 : spin_unlock(&ctl->tree_lock);
2724 177 : return -ENOSPC;
2725 : }
2726 :
2727 : spin_lock(&cluster->lock);
2728 :
2729 : /* someone already found a cluster, hooray */
2730 217 : if (cluster->block_group) {
2731 : ret = 0;
2732 : goto out;
2733 : }
2734 :
2735 217 : trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
2736 : min_bytes);
2737 :
2738 : INIT_LIST_HEAD(&bitmaps);
2739 217 : ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
2740 : bytes + empty_size,
2741 : cont1_bytes, min_bytes);
2742 217 : if (ret)
2743 2 : ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
2744 : offset, bytes + empty_size,
2745 : cont1_bytes, min_bytes);
2746 :
2747 : /* Clear our temporary list */
2748 226 : list_for_each_entry_safe(entry, tmp, &bitmaps, list)
2749 : list_del_init(&entry->list);
2750 :
2751 217 : if (!ret) {
2752 217 : atomic_inc(&block_group->count);
2753 217 : list_add_tail(&cluster->block_group_list,
2754 : &block_group->cluster_list);
2755 217 : cluster->block_group = block_group;
2756 : } else {
2757 0 : trace_btrfs_failed_cluster_setup(block_group);
2758 : }
2759 : out:
2760 : spin_unlock(&cluster->lock);
2761 : spin_unlock(&ctl->tree_lock);
2762 :
2763 217 : return ret;
2764 : }
2765 :
2766 : /*
2767 : * simple code to zero out a cluster
2768 : */
2769 442 : void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
2770 : {
2771 442 : spin_lock_init(&cluster->lock);
2772 442 : spin_lock_init(&cluster->refill_lock);
2773 442 : cluster->root = RB_ROOT;
2774 442 : cluster->max_size = 0;
2775 442 : INIT_LIST_HEAD(&cluster->block_group_list);
2776 442 : cluster->block_group = NULL;
2777 442 : }
2778 :
2779 0 : static int do_trimming(struct btrfs_block_group_cache *block_group,
2780 : u64 *total_trimmed, u64 start, u64 bytes,
2781 : u64 reserved_start, u64 reserved_bytes)
2782 : {
2783 0 : struct btrfs_space_info *space_info = block_group->space_info;
2784 0 : struct btrfs_fs_info *fs_info = block_group->fs_info;
2785 : int ret;
2786 : int update = 0;
2787 0 : u64 trimmed = 0;
2788 :
2789 : spin_lock(&space_info->lock);
2790 : spin_lock(&block_group->lock);
2791 0 : if (!block_group->ro) {
2792 0 : block_group->reserved += reserved_bytes;
2793 0 : space_info->bytes_reserved += reserved_bytes;
2794 : update = 1;
2795 : }
2796 : spin_unlock(&block_group->lock);
2797 : spin_unlock(&space_info->lock);
2798 :
2799 0 : ret = btrfs_error_discard_extent(fs_info->extent_root,
2800 : start, bytes, &trimmed);
2801 0 : if (!ret)
2802 0 : *total_trimmed += trimmed;
2803 :
2804 : btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
2805 :
2806 0 : if (update) {
2807 : spin_lock(&space_info->lock);
2808 : spin_lock(&block_group->lock);
2809 0 : if (block_group->ro)
2810 0 : space_info->bytes_readonly += reserved_bytes;
2811 0 : block_group->reserved -= reserved_bytes;
2812 0 : space_info->bytes_reserved -= reserved_bytes;
2813 : spin_unlock(&space_info->lock);
2814 : spin_unlock(&block_group->lock);
2815 : }
2816 :
2817 0 : return ret;
2818 : }
2819 :
2820 0 : static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
2821 : u64 *total_trimmed, u64 start, u64 end, u64 minlen)
2822 : {
2823 0 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2824 : struct btrfs_free_space *entry;
2825 : struct rb_node *node;
2826 : int ret = 0;
2827 : u64 extent_start;
2828 : u64 extent_bytes;
2829 : u64 bytes;
2830 :
2831 0 : while (start < end) {
2832 : spin_lock(&ctl->tree_lock);
2833 :
2834 0 : if (ctl->free_space < minlen) {
2835 : spin_unlock(&ctl->tree_lock);
2836 : break;
2837 : }
2838 :
2839 0 : entry = tree_search_offset(ctl, start, 0, 1);
2840 0 : if (!entry) {
2841 : spin_unlock(&ctl->tree_lock);
2842 : break;
2843 : }
2844 :
2845 : /* skip bitmaps */
2846 0 : while (entry->bitmap) {
2847 0 : node = rb_next(&entry->offset_index);
2848 0 : if (!node) {
2849 : spin_unlock(&ctl->tree_lock);
2850 : goto out;
2851 : }
2852 : entry = rb_entry(node, struct btrfs_free_space,
2853 : offset_index);
2854 : }
2855 :
2856 0 : if (entry->offset >= end) {
2857 : spin_unlock(&ctl->tree_lock);
2858 : break;
2859 : }
2860 :
2861 : extent_start = entry->offset;
2862 0 : extent_bytes = entry->bytes;
2863 0 : start = max(start, extent_start);
2864 0 : bytes = min(extent_start + extent_bytes, end) - start;
2865 0 : if (bytes < minlen) {
2866 : spin_unlock(&ctl->tree_lock);
2867 : goto next;
2868 : }
2869 :
2870 : unlink_free_space(ctl, entry);
2871 0 : kmem_cache_free(btrfs_free_space_cachep, entry);
2872 :
2873 : spin_unlock(&ctl->tree_lock);
2874 :
2875 0 : ret = do_trimming(block_group, total_trimmed, start, bytes,
2876 : extent_start, extent_bytes);
2877 0 : if (ret)
2878 : break;
2879 : next:
2880 : start += bytes;
2881 :
2882 0 : if (fatal_signal_pending(current)) {
2883 : ret = -ERESTARTSYS;
2884 : break;
2885 : }
2886 :
2887 0 : cond_resched();
2888 : }
2889 : out:
2890 0 : return ret;
2891 : }
2892 :
2893 0 : static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
2894 : u64 *total_trimmed, u64 start, u64 end, u64 minlen)
2895 : {
2896 0 : struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2897 : struct btrfs_free_space *entry;
2898 : int ret = 0;
2899 : int ret2;
2900 : u64 bytes;
2901 0 : u64 offset = offset_to_bitmap(ctl, start);
2902 :
2903 0 : while (offset < end) {
2904 : bool next_bitmap = false;
2905 :
2906 : spin_lock(&ctl->tree_lock);
2907 :
2908 0 : if (ctl->free_space < minlen) {
2909 : spin_unlock(&ctl->tree_lock);
2910 : break;
2911 : }
2912 :
2913 0 : entry = tree_search_offset(ctl, offset, 1, 0);
2914 0 : if (!entry) {
2915 : spin_unlock(&ctl->tree_lock);
2916 : next_bitmap = true;
2917 0 : goto next;
2918 : }
2919 :
2920 0 : bytes = minlen;
2921 0 : ret2 = search_bitmap(ctl, entry, &start, &bytes);
2922 0 : if (ret2 || start >= end) {
2923 : spin_unlock(&ctl->tree_lock);
2924 : next_bitmap = true;
2925 0 : goto next;
2926 : }
2927 :
2928 0 : bytes = min(bytes, end - start);
2929 0 : if (bytes < minlen) {
2930 : spin_unlock(&ctl->tree_lock);
2931 : goto next;
2932 : }
2933 :
2934 0 : bitmap_clear_bits(ctl, entry, start, bytes);
2935 0 : if (entry->bytes == 0)
2936 0 : free_bitmap(ctl, entry);
2937 :
2938 : spin_unlock(&ctl->tree_lock);
2939 :
2940 0 : ret = do_trimming(block_group, total_trimmed, start, bytes,
2941 : start, bytes);
2942 0 : if (ret)
2943 : break;
2944 : next:
2945 0 : if (next_bitmap) {
2946 0 : offset += BITS_PER_BITMAP * ctl->unit;
2947 : } else {
2948 0 : start += bytes;
2949 0 : if (start >= offset + BITS_PER_BITMAP * ctl->unit)
2950 : offset += BITS_PER_BITMAP * ctl->unit;
2951 : }
2952 :
2953 0 : if (fatal_signal_pending(current)) {
2954 : ret = -ERESTARTSYS;
2955 : break;
2956 : }
2957 :
2958 0 : cond_resched();
2959 : }
2960 :
2961 0 : return ret;
2962 : }
2963 :
2964 0 : int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
2965 : u64 *trimmed, u64 start, u64 end, u64 minlen)
2966 : {
2967 : int ret;
2968 :
2969 0 : *trimmed = 0;
2970 :
2971 0 : ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
2972 0 : if (ret)
2973 : return ret;
2974 :
2975 0 : ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
2976 :
2977 0 : return ret;
2978 : }
2979 :
2980 : /*
2981 : * Find the left-most item in the cache tree, and then return the
2982 : * smallest inode number in the item.
2983 : *
2984 : * Note: the returned inode number may not be the smallest one in
2985 : * the tree, if the left-most item is a bitmap.
2986 : */
2987 0 : u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
2988 : {
2989 0 : struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
2990 : struct btrfs_free_space *entry = NULL;
2991 : u64 ino = 0;
2992 :
2993 : spin_lock(&ctl->tree_lock);
2994 :
2995 0 : if (RB_EMPTY_ROOT(&ctl->free_space_offset))
2996 : goto out;
2997 :
2998 0 : entry = rb_entry(rb_first(&ctl->free_space_offset),
2999 : struct btrfs_free_space, offset_index);
3000 :
3001 0 : if (!entry->bitmap) {
3002 0 : ino = entry->offset;
3003 :
3004 : unlink_free_space(ctl, entry);
3005 0 : entry->offset++;
3006 0 : entry->bytes--;
3007 0 : if (!entry->bytes)
3008 0 : kmem_cache_free(btrfs_free_space_cachep, entry);
3009 : else
3010 0 : link_free_space(ctl, entry);
3011 : } else {
3012 0 : u64 offset = 0;
3013 0 : u64 count = 1;
3014 : int ret;
3015 :
3016 0 : ret = search_bitmap(ctl, entry, &offset, &count);
3017 : /* Logic error; Should be empty if it can't find anything */
3018 : ASSERT(!ret);
3019 :
3020 0 : ino = offset;
3021 0 : bitmap_clear_bits(ctl, entry, offset, 1);
3022 0 : if (entry->bytes == 0)
3023 0 : free_bitmap(ctl, entry);
3024 : }
3025 : out:
3026 : spin_unlock(&ctl->tree_lock);
3027 :
3028 0 : return ino;
3029 : }
3030 :
3031 0 : struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3032 : struct btrfs_path *path)
3033 : {
3034 : struct inode *inode = NULL;
3035 :
3036 : spin_lock(&root->cache_lock);
3037 0 : if (root->cache_inode)
3038 0 : inode = igrab(root->cache_inode);
3039 : spin_unlock(&root->cache_lock);
3040 0 : if (inode)
3041 : return inode;
3042 :
3043 0 : inode = __lookup_free_space_inode(root, path, 0);
3044 0 : if (IS_ERR(inode))
3045 : return inode;
3046 :
3047 : spin_lock(&root->cache_lock);
3048 0 : if (!btrfs_fs_closing(root->fs_info))
3049 0 : root->cache_inode = igrab(inode);
3050 : spin_unlock(&root->cache_lock);
3051 :
3052 0 : return inode;
3053 : }
3054 :
3055 0 : int create_free_ino_inode(struct btrfs_root *root,
3056 : struct btrfs_trans_handle *trans,
3057 : struct btrfs_path *path)
3058 : {
3059 0 : return __create_free_space_inode(root, trans, path,
3060 : BTRFS_FREE_INO_OBJECTID, 0);
3061 : }
3062 :
3063 0 : int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3064 : {
3065 0 : struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3066 : struct btrfs_path *path;
3067 : struct inode *inode;
3068 : int ret = 0;
3069 : u64 root_gen = btrfs_root_generation(&root->root_item);
3070 :
3071 0 : if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3072 : return 0;
3073 :
3074 : /*
3075 : * If we're unmounting then just return, since this does a search on the
3076 : * normal root and not the commit root and we could deadlock.
3077 : */
3078 0 : if (btrfs_fs_closing(fs_info))
3079 : return 0;
3080 :
3081 0 : path = btrfs_alloc_path();
3082 0 : if (!path)
3083 : return 0;
3084 :
3085 0 : inode = lookup_free_ino_inode(root, path);
3086 0 : if (IS_ERR(inode))
3087 : goto out;
3088 :
3089 0 : if (root_gen != BTRFS_I(inode)->generation)
3090 : goto out_put;
3091 :
3092 0 : ret = __load_free_space_cache(root, inode, ctl, path, 0);
3093 :
3094 0 : if (ret < 0)
3095 0 : btrfs_err(fs_info,
3096 : "failed to load free ino cache for root %llu",
3097 : root->root_key.objectid);
3098 : out_put:
3099 0 : iput(inode);
3100 : out:
3101 0 : btrfs_free_path(path);
3102 0 : return ret;
3103 : }
3104 :
3105 0 : int btrfs_write_out_ino_cache(struct btrfs_root *root,
3106 : struct btrfs_trans_handle *trans,
3107 : struct btrfs_path *path,
3108 : struct inode *inode)
3109 : {
3110 0 : struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3111 : int ret;
3112 :
3113 0 : if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3114 : return 0;
3115 :
3116 0 : ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0);
3117 0 : if (ret) {
3118 0 : btrfs_delalloc_release_metadata(inode, inode->i_size);
3119 : #ifdef DEBUG
3120 : btrfs_err(root->fs_info,
3121 : "failed to write free ino cache for root %llu",
3122 : root->root_key.objectid);
3123 : #endif
3124 : }
3125 :
3126 0 : return ret;
3127 : }
3128 :
3129 : #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3130 : /*
3131 : * Use this if you need to make a bitmap or extent entry specifically, it
3132 : * doesn't do any of the merging that add_free_space does, this acts a lot like
3133 : * how the free space cache loading stuff works, so you can get really weird
3134 : * configurations.
3135 : */
3136 : int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3137 : u64 offset, u64 bytes, bool bitmap)
3138 : {
3139 : struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3140 : struct btrfs_free_space *info = NULL, *bitmap_info;
3141 : void *map = NULL;
3142 : u64 bytes_added;
3143 : int ret;
3144 :
3145 : again:
3146 : if (!info) {
3147 : info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3148 : if (!info)
3149 : return -ENOMEM;
3150 : }
3151 :
3152 : if (!bitmap) {
3153 : spin_lock(&ctl->tree_lock);
3154 : info->offset = offset;
3155 : info->bytes = bytes;
3156 : ret = link_free_space(ctl, info);
3157 : spin_unlock(&ctl->tree_lock);
3158 : if (ret)
3159 : kmem_cache_free(btrfs_free_space_cachep, info);
3160 : return ret;
3161 : }
3162 :
3163 : if (!map) {
3164 : map = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
3165 : if (!map) {
3166 : kmem_cache_free(btrfs_free_space_cachep, info);
3167 : return -ENOMEM;
3168 : }
3169 : }
3170 :
3171 : spin_lock(&ctl->tree_lock);
3172 : bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3173 : 1, 0);
3174 : if (!bitmap_info) {
3175 : info->bitmap = map;
3176 : map = NULL;
3177 : add_new_bitmap(ctl, info, offset);
3178 : bitmap_info = info;
3179 : }
3180 :
3181 : bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3182 : bytes -= bytes_added;
3183 : offset += bytes_added;
3184 : spin_unlock(&ctl->tree_lock);
3185 :
3186 : if (bytes)
3187 : goto again;
3188 :
3189 : if (map)
3190 : kfree(map);
3191 : return 0;
3192 : }
3193 :
3194 : /*
3195 : * Checks to see if the given range is in the free space cache. This is really
3196 : * just used to check the absence of space, so if there is free space in the
3197 : * range at all we will return 1.
3198 : */
3199 : int test_check_exists(struct btrfs_block_group_cache *cache,
3200 : u64 offset, u64 bytes)
3201 : {
3202 : struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3203 : struct btrfs_free_space *info;
3204 : int ret = 0;
3205 :
3206 : spin_lock(&ctl->tree_lock);
3207 : info = tree_search_offset(ctl, offset, 0, 0);
3208 : if (!info) {
3209 : info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3210 : 1, 0);
3211 : if (!info)
3212 : goto out;
3213 : }
3214 :
3215 : have_info:
3216 : if (info->bitmap) {
3217 : u64 bit_off, bit_bytes;
3218 : struct rb_node *n;
3219 : struct btrfs_free_space *tmp;
3220 :
3221 : bit_off = offset;
3222 : bit_bytes = ctl->unit;
3223 : ret = search_bitmap(ctl, info, &bit_off, &bit_bytes);
3224 : if (!ret) {
3225 : if (bit_off == offset) {
3226 : ret = 1;
3227 : goto out;
3228 : } else if (bit_off > offset &&
3229 : offset + bytes > bit_off) {
3230 : ret = 1;
3231 : goto out;
3232 : }
3233 : }
3234 :
3235 : n = rb_prev(&info->offset_index);
3236 : while (n) {
3237 : tmp = rb_entry(n, struct btrfs_free_space,
3238 : offset_index);
3239 : if (tmp->offset + tmp->bytes < offset)
3240 : break;
3241 : if (offset + bytes < tmp->offset) {
3242 : n = rb_prev(&info->offset_index);
3243 : continue;
3244 : }
3245 : info = tmp;
3246 : goto have_info;
3247 : }
3248 :
3249 : n = rb_next(&info->offset_index);
3250 : while (n) {
3251 : tmp = rb_entry(n, struct btrfs_free_space,
3252 : offset_index);
3253 : if (offset + bytes < tmp->offset)
3254 : break;
3255 : if (tmp->offset + tmp->bytes < offset) {
3256 : n = rb_next(&info->offset_index);
3257 : continue;
3258 : }
3259 : info = tmp;
3260 : goto have_info;
3261 : }
3262 :
3263 : goto out;
3264 : }
3265 :
3266 : if (info->offset == offset) {
3267 : ret = 1;
3268 : goto out;
3269 : }
3270 :
3271 : if (offset > info->offset && offset < info->offset + info->bytes)
3272 : ret = 1;
3273 : out:
3274 : spin_unlock(&ctl->tree_lock);
3275 : return ret;
3276 : }
3277 : #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
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