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powerpc: Fix bad inline asm constraint in create_zero_mask()
[deliverable/linux.git] / fs / btrfs / free-space-cache.c
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 #include "volumes.h"
31
32 #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
33 #define MAX_CACHE_BYTES_PER_GIG SZ_32K
34
35 struct btrfs_trim_range {
36 u64 start;
37 u64 bytes;
38 struct list_head list;
39 };
40
41 static int link_free_space(struct btrfs_free_space_ctl *ctl,
42 struct btrfs_free_space *info);
43 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
44 struct btrfs_free_space *info);
45
46 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
47 struct btrfs_path *path,
48 u64 offset)
49 {
50 struct btrfs_key key;
51 struct btrfs_key location;
52 struct btrfs_disk_key disk_key;
53 struct btrfs_free_space_header *header;
54 struct extent_buffer *leaf;
55 struct inode *inode = NULL;
56 int ret;
57
58 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
59 key.offset = offset;
60 key.type = 0;
61
62 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
63 if (ret < 0)
64 return ERR_PTR(ret);
65 if (ret > 0) {
66 btrfs_release_path(path);
67 return ERR_PTR(-ENOENT);
68 }
69
70 leaf = path->nodes[0];
71 header = btrfs_item_ptr(leaf, path->slots[0],
72 struct btrfs_free_space_header);
73 btrfs_free_space_key(leaf, header, &disk_key);
74 btrfs_disk_key_to_cpu(&location, &disk_key);
75 btrfs_release_path(path);
76
77 inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
78 if (!inode)
79 return ERR_PTR(-ENOENT);
80 if (IS_ERR(inode))
81 return inode;
82 if (is_bad_inode(inode)) {
83 iput(inode);
84 return ERR_PTR(-ENOENT);
85 }
86
87 mapping_set_gfp_mask(inode->i_mapping,
88 mapping_gfp_constraint(inode->i_mapping,
89 ~(__GFP_FS | __GFP_HIGHMEM)));
90
91 return inode;
92 }
93
94 struct inode *lookup_free_space_inode(struct btrfs_root *root,
95 struct btrfs_block_group_cache
96 *block_group, struct btrfs_path *path)
97 {
98 struct inode *inode = NULL;
99 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
100
101 spin_lock(&block_group->lock);
102 if (block_group->inode)
103 inode = igrab(block_group->inode);
104 spin_unlock(&block_group->lock);
105 if (inode)
106 return inode;
107
108 inode = __lookup_free_space_inode(root, path,
109 block_group->key.objectid);
110 if (IS_ERR(inode))
111 return inode;
112
113 spin_lock(&block_group->lock);
114 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
115 btrfs_info(root->fs_info,
116 "Old style space inode found, converting.");
117 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
118 BTRFS_INODE_NODATACOW;
119 block_group->disk_cache_state = BTRFS_DC_CLEAR;
120 }
121
122 if (!block_group->iref) {
123 block_group->inode = igrab(inode);
124 block_group->iref = 1;
125 }
126 spin_unlock(&block_group->lock);
127
128 return inode;
129 }
130
131 static int __create_free_space_inode(struct btrfs_root *root,
132 struct btrfs_trans_handle *trans,
133 struct btrfs_path *path,
134 u64 ino, u64 offset)
135 {
136 struct btrfs_key key;
137 struct btrfs_disk_key disk_key;
138 struct btrfs_free_space_header *header;
139 struct btrfs_inode_item *inode_item;
140 struct extent_buffer *leaf;
141 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
142 int ret;
143
144 ret = btrfs_insert_empty_inode(trans, root, path, ino);
145 if (ret)
146 return ret;
147
148 /* We inline crc's for the free disk space cache */
149 if (ino != BTRFS_FREE_INO_OBJECTID)
150 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
151
152 leaf = path->nodes[0];
153 inode_item = btrfs_item_ptr(leaf, path->slots[0],
154 struct btrfs_inode_item);
155 btrfs_item_key(leaf, &disk_key, path->slots[0]);
156 memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
157 sizeof(*inode_item));
158 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
159 btrfs_set_inode_size(leaf, inode_item, 0);
160 btrfs_set_inode_nbytes(leaf, inode_item, 0);
161 btrfs_set_inode_uid(leaf, inode_item, 0);
162 btrfs_set_inode_gid(leaf, inode_item, 0);
163 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
164 btrfs_set_inode_flags(leaf, inode_item, flags);
165 btrfs_set_inode_nlink(leaf, inode_item, 1);
166 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
167 btrfs_set_inode_block_group(leaf, inode_item, offset);
168 btrfs_mark_buffer_dirty(leaf);
169 btrfs_release_path(path);
170
171 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
172 key.offset = offset;
173 key.type = 0;
174 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 sizeof(struct btrfs_free_space_header));
176 if (ret < 0) {
177 btrfs_release_path(path);
178 return ret;
179 }
180
181 leaf = path->nodes[0];
182 header = btrfs_item_ptr(leaf, path->slots[0],
183 struct btrfs_free_space_header);
184 memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
185 btrfs_set_free_space_key(leaf, header, &disk_key);
186 btrfs_mark_buffer_dirty(leaf);
187 btrfs_release_path(path);
188
189 return 0;
190 }
191
192 int create_free_space_inode(struct btrfs_root *root,
193 struct btrfs_trans_handle *trans,
194 struct btrfs_block_group_cache *block_group,
195 struct btrfs_path *path)
196 {
197 int ret;
198 u64 ino;
199
200 ret = btrfs_find_free_objectid(root, &ino);
201 if (ret < 0)
202 return ret;
203
204 return __create_free_space_inode(root, trans, path, ino,
205 block_group->key.objectid);
206 }
207
208 int btrfs_check_trunc_cache_free_space(struct btrfs_root *root,
209 struct btrfs_block_rsv *rsv)
210 {
211 u64 needed_bytes;
212 int ret;
213
214 /* 1 for slack space, 1 for updating the inode */
215 needed_bytes = btrfs_calc_trunc_metadata_size(root, 1) +
216 btrfs_calc_trans_metadata_size(root, 1);
217
218 spin_lock(&rsv->lock);
219 if (rsv->reserved < needed_bytes)
220 ret = -ENOSPC;
221 else
222 ret = 0;
223 spin_unlock(&rsv->lock);
224 return ret;
225 }
226
227 int btrfs_truncate_free_space_cache(struct btrfs_root *root,
228 struct btrfs_trans_handle *trans,
229 struct btrfs_block_group_cache *block_group,
230 struct inode *inode)
231 {
232 int ret = 0;
233 struct btrfs_path *path = btrfs_alloc_path();
234 bool locked = false;
235
236 if (!path) {
237 ret = -ENOMEM;
238 goto fail;
239 }
240
241 if (block_group) {
242 locked = true;
243 mutex_lock(&trans->transaction->cache_write_mutex);
244 if (!list_empty(&block_group->io_list)) {
245 list_del_init(&block_group->io_list);
246
247 btrfs_wait_cache_io(root, trans, block_group,
248 &block_group->io_ctl, path,
249 block_group->key.objectid);
250 btrfs_put_block_group(block_group);
251 }
252
253 /*
254 * now that we've truncated the cache away, its no longer
255 * setup or written
256 */
257 spin_lock(&block_group->lock);
258 block_group->disk_cache_state = BTRFS_DC_CLEAR;
259 spin_unlock(&block_group->lock);
260 }
261 btrfs_free_path(path);
262
263 btrfs_i_size_write(inode, 0);
264 truncate_pagecache(inode, 0);
265
266 /*
267 * We don't need an orphan item because truncating the free space cache
268 * will never be split across transactions.
269 * We don't need to check for -EAGAIN because we're a free space
270 * cache inode
271 */
272 ret = btrfs_truncate_inode_items(trans, root, inode,
273 0, BTRFS_EXTENT_DATA_KEY);
274 if (ret)
275 goto fail;
276
277 ret = btrfs_update_inode(trans, root, inode);
278
279 fail:
280 if (locked)
281 mutex_unlock(&trans->transaction->cache_write_mutex);
282 if (ret)
283 btrfs_abort_transaction(trans, root, ret);
284
285 return ret;
286 }
287
288 static int readahead_cache(struct inode *inode)
289 {
290 struct file_ra_state *ra;
291 unsigned long last_index;
292
293 ra = kzalloc(sizeof(*ra), GFP_NOFS);
294 if (!ra)
295 return -ENOMEM;
296
297 file_ra_state_init(ra, inode->i_mapping);
298 last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
299
300 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
301
302 kfree(ra);
303
304 return 0;
305 }
306
307 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
308 struct btrfs_root *root, int write)
309 {
310 int num_pages;
311 int check_crcs = 0;
312
313 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
314
315 if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
316 check_crcs = 1;
317
318 /* Make sure we can fit our crcs into the first page */
319 if (write && check_crcs &&
320 (num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
321 return -ENOSPC;
322
323 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
324
325 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
326 if (!io_ctl->pages)
327 return -ENOMEM;
328
329 io_ctl->num_pages = num_pages;
330 io_ctl->root = root;
331 io_ctl->check_crcs = check_crcs;
332 io_ctl->inode = inode;
333
334 return 0;
335 }
336
337 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
338 {
339 kfree(io_ctl->pages);
340 io_ctl->pages = NULL;
341 }
342
343 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
344 {
345 if (io_ctl->cur) {
346 io_ctl->cur = NULL;
347 io_ctl->orig = NULL;
348 }
349 }
350
351 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
352 {
353 ASSERT(io_ctl->index < io_ctl->num_pages);
354 io_ctl->page = io_ctl->pages[io_ctl->index++];
355 io_ctl->cur = page_address(io_ctl->page);
356 io_ctl->orig = io_ctl->cur;
357 io_ctl->size = PAGE_CACHE_SIZE;
358 if (clear)
359 memset(io_ctl->cur, 0, PAGE_CACHE_SIZE);
360 }
361
362 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
363 {
364 int i;
365
366 io_ctl_unmap_page(io_ctl);
367
368 for (i = 0; i < io_ctl->num_pages; i++) {
369 if (io_ctl->pages[i]) {
370 ClearPageChecked(io_ctl->pages[i]);
371 unlock_page(io_ctl->pages[i]);
372 page_cache_release(io_ctl->pages[i]);
373 }
374 }
375 }
376
377 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
378 int uptodate)
379 {
380 struct page *page;
381 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
382 int i;
383
384 for (i = 0; i < io_ctl->num_pages; i++) {
385 page = find_or_create_page(inode->i_mapping, i, mask);
386 if (!page) {
387 io_ctl_drop_pages(io_ctl);
388 return -ENOMEM;
389 }
390 io_ctl->pages[i] = page;
391 if (uptodate && !PageUptodate(page)) {
392 btrfs_readpage(NULL, page);
393 lock_page(page);
394 if (!PageUptodate(page)) {
395 btrfs_err(BTRFS_I(inode)->root->fs_info,
396 "error reading free space cache");
397 io_ctl_drop_pages(io_ctl);
398 return -EIO;
399 }
400 }
401 }
402
403 for (i = 0; i < io_ctl->num_pages; i++) {
404 clear_page_dirty_for_io(io_ctl->pages[i]);
405 set_page_extent_mapped(io_ctl->pages[i]);
406 }
407
408 return 0;
409 }
410
411 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
412 {
413 __le64 *val;
414
415 io_ctl_map_page(io_ctl, 1);
416
417 /*
418 * Skip the csum areas. If we don't check crcs then we just have a
419 * 64bit chunk at the front of the first page.
420 */
421 if (io_ctl->check_crcs) {
422 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
423 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
424 } else {
425 io_ctl->cur += sizeof(u64);
426 io_ctl->size -= sizeof(u64) * 2;
427 }
428
429 val = io_ctl->cur;
430 *val = cpu_to_le64(generation);
431 io_ctl->cur += sizeof(u64);
432 }
433
434 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
435 {
436 __le64 *gen;
437
438 /*
439 * Skip the crc area. If we don't check crcs then we just have a 64bit
440 * chunk at the front of the first page.
441 */
442 if (io_ctl->check_crcs) {
443 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
444 io_ctl->size -= sizeof(u64) +
445 (sizeof(u32) * io_ctl->num_pages);
446 } else {
447 io_ctl->cur += sizeof(u64);
448 io_ctl->size -= sizeof(u64) * 2;
449 }
450
451 gen = io_ctl->cur;
452 if (le64_to_cpu(*gen) != generation) {
453 btrfs_err_rl(io_ctl->root->fs_info,
454 "space cache generation (%llu) does not match inode (%llu)",
455 *gen, generation);
456 io_ctl_unmap_page(io_ctl);
457 return -EIO;
458 }
459 io_ctl->cur += sizeof(u64);
460 return 0;
461 }
462
463 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
464 {
465 u32 *tmp;
466 u32 crc = ~(u32)0;
467 unsigned offset = 0;
468
469 if (!io_ctl->check_crcs) {
470 io_ctl_unmap_page(io_ctl);
471 return;
472 }
473
474 if (index == 0)
475 offset = sizeof(u32) * io_ctl->num_pages;
476
477 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
478 PAGE_CACHE_SIZE - offset);
479 btrfs_csum_final(crc, (char *)&crc);
480 io_ctl_unmap_page(io_ctl);
481 tmp = page_address(io_ctl->pages[0]);
482 tmp += index;
483 *tmp = crc;
484 }
485
486 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
487 {
488 u32 *tmp, val;
489 u32 crc = ~(u32)0;
490 unsigned offset = 0;
491
492 if (!io_ctl->check_crcs) {
493 io_ctl_map_page(io_ctl, 0);
494 return 0;
495 }
496
497 if (index == 0)
498 offset = sizeof(u32) * io_ctl->num_pages;
499
500 tmp = page_address(io_ctl->pages[0]);
501 tmp += index;
502 val = *tmp;
503
504 io_ctl_map_page(io_ctl, 0);
505 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
506 PAGE_CACHE_SIZE - offset);
507 btrfs_csum_final(crc, (char *)&crc);
508 if (val != crc) {
509 btrfs_err_rl(io_ctl->root->fs_info,
510 "csum mismatch on free space cache");
511 io_ctl_unmap_page(io_ctl);
512 return -EIO;
513 }
514
515 return 0;
516 }
517
518 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
519 void *bitmap)
520 {
521 struct btrfs_free_space_entry *entry;
522
523 if (!io_ctl->cur)
524 return -ENOSPC;
525
526 entry = io_ctl->cur;
527 entry->offset = cpu_to_le64(offset);
528 entry->bytes = cpu_to_le64(bytes);
529 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
530 BTRFS_FREE_SPACE_EXTENT;
531 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
532 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
533
534 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
535 return 0;
536
537 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
538
539 /* No more pages to map */
540 if (io_ctl->index >= io_ctl->num_pages)
541 return 0;
542
543 /* map the next page */
544 io_ctl_map_page(io_ctl, 1);
545 return 0;
546 }
547
548 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
549 {
550 if (!io_ctl->cur)
551 return -ENOSPC;
552
553 /*
554 * If we aren't at the start of the current page, unmap this one and
555 * map the next one if there is any left.
556 */
557 if (io_ctl->cur != io_ctl->orig) {
558 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
559 if (io_ctl->index >= io_ctl->num_pages)
560 return -ENOSPC;
561 io_ctl_map_page(io_ctl, 0);
562 }
563
564 memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE);
565 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
566 if (io_ctl->index < io_ctl->num_pages)
567 io_ctl_map_page(io_ctl, 0);
568 return 0;
569 }
570
571 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
572 {
573 /*
574 * If we're not on the boundary we know we've modified the page and we
575 * need to crc the page.
576 */
577 if (io_ctl->cur != io_ctl->orig)
578 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
579 else
580 io_ctl_unmap_page(io_ctl);
581
582 while (io_ctl->index < io_ctl->num_pages) {
583 io_ctl_map_page(io_ctl, 1);
584 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
585 }
586 }
587
588 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
589 struct btrfs_free_space *entry, u8 *type)
590 {
591 struct btrfs_free_space_entry *e;
592 int ret;
593
594 if (!io_ctl->cur) {
595 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
596 if (ret)
597 return ret;
598 }
599
600 e = io_ctl->cur;
601 entry->offset = le64_to_cpu(e->offset);
602 entry->bytes = le64_to_cpu(e->bytes);
603 *type = e->type;
604 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
605 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
606
607 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
608 return 0;
609
610 io_ctl_unmap_page(io_ctl);
611
612 return 0;
613 }
614
615 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
616 struct btrfs_free_space *entry)
617 {
618 int ret;
619
620 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
621 if (ret)
622 return ret;
623
624 memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE);
625 io_ctl_unmap_page(io_ctl);
626
627 return 0;
628 }
629
630 /*
631 * Since we attach pinned extents after the fact we can have contiguous sections
632 * of free space that are split up in entries. This poses a problem with the
633 * tree logging stuff since it could have allocated across what appears to be 2
634 * entries since we would have merged the entries when adding the pinned extents
635 * back to the free space cache. So run through the space cache that we just
636 * loaded and merge contiguous entries. This will make the log replay stuff not
637 * blow up and it will make for nicer allocator behavior.
638 */
639 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
640 {
641 struct btrfs_free_space *e, *prev = NULL;
642 struct rb_node *n;
643
644 again:
645 spin_lock(&ctl->tree_lock);
646 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
647 e = rb_entry(n, struct btrfs_free_space, offset_index);
648 if (!prev)
649 goto next;
650 if (e->bitmap || prev->bitmap)
651 goto next;
652 if (prev->offset + prev->bytes == e->offset) {
653 unlink_free_space(ctl, prev);
654 unlink_free_space(ctl, e);
655 prev->bytes += e->bytes;
656 kmem_cache_free(btrfs_free_space_cachep, e);
657 link_free_space(ctl, prev);
658 prev = NULL;
659 spin_unlock(&ctl->tree_lock);
660 goto again;
661 }
662 next:
663 prev = e;
664 }
665 spin_unlock(&ctl->tree_lock);
666 }
667
668 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
669 struct btrfs_free_space_ctl *ctl,
670 struct btrfs_path *path, u64 offset)
671 {
672 struct btrfs_free_space_header *header;
673 struct extent_buffer *leaf;
674 struct btrfs_io_ctl io_ctl;
675 struct btrfs_key key;
676 struct btrfs_free_space *e, *n;
677 LIST_HEAD(bitmaps);
678 u64 num_entries;
679 u64 num_bitmaps;
680 u64 generation;
681 u8 type;
682 int ret = 0;
683
684 /* Nothing in the space cache, goodbye */
685 if (!i_size_read(inode))
686 return 0;
687
688 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
689 key.offset = offset;
690 key.type = 0;
691
692 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
693 if (ret < 0)
694 return 0;
695 else if (ret > 0) {
696 btrfs_release_path(path);
697 return 0;
698 }
699
700 ret = -1;
701
702 leaf = path->nodes[0];
703 header = btrfs_item_ptr(leaf, path->slots[0],
704 struct btrfs_free_space_header);
705 num_entries = btrfs_free_space_entries(leaf, header);
706 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
707 generation = btrfs_free_space_generation(leaf, header);
708 btrfs_release_path(path);
709
710 if (!BTRFS_I(inode)->generation) {
711 btrfs_info(root->fs_info,
712 "The free space cache file (%llu) is invalid. skip it\n",
713 offset);
714 return 0;
715 }
716
717 if (BTRFS_I(inode)->generation != generation) {
718 btrfs_err(root->fs_info,
719 "free space inode generation (%llu) "
720 "did not match free space cache generation (%llu)",
721 BTRFS_I(inode)->generation, generation);
722 return 0;
723 }
724
725 if (!num_entries)
726 return 0;
727
728 ret = io_ctl_init(&io_ctl, inode, root, 0);
729 if (ret)
730 return ret;
731
732 ret = readahead_cache(inode);
733 if (ret)
734 goto out;
735
736 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
737 if (ret)
738 goto out;
739
740 ret = io_ctl_check_crc(&io_ctl, 0);
741 if (ret)
742 goto free_cache;
743
744 ret = io_ctl_check_generation(&io_ctl, generation);
745 if (ret)
746 goto free_cache;
747
748 while (num_entries) {
749 e = kmem_cache_zalloc(btrfs_free_space_cachep,
750 GFP_NOFS);
751 if (!e)
752 goto free_cache;
753
754 ret = io_ctl_read_entry(&io_ctl, e, &type);
755 if (ret) {
756 kmem_cache_free(btrfs_free_space_cachep, e);
757 goto free_cache;
758 }
759
760 if (!e->bytes) {
761 kmem_cache_free(btrfs_free_space_cachep, e);
762 goto free_cache;
763 }
764
765 if (type == BTRFS_FREE_SPACE_EXTENT) {
766 spin_lock(&ctl->tree_lock);
767 ret = link_free_space(ctl, e);
768 spin_unlock(&ctl->tree_lock);
769 if (ret) {
770 btrfs_err(root->fs_info,
771 "Duplicate entries in free space cache, dumping");
772 kmem_cache_free(btrfs_free_space_cachep, e);
773 goto free_cache;
774 }
775 } else {
776 ASSERT(num_bitmaps);
777 num_bitmaps--;
778 e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
779 if (!e->bitmap) {
780 kmem_cache_free(
781 btrfs_free_space_cachep, e);
782 goto free_cache;
783 }
784 spin_lock(&ctl->tree_lock);
785 ret = link_free_space(ctl, e);
786 ctl->total_bitmaps++;
787 ctl->op->recalc_thresholds(ctl);
788 spin_unlock(&ctl->tree_lock);
789 if (ret) {
790 btrfs_err(root->fs_info,
791 "Duplicate entries in free space cache, dumping");
792 kmem_cache_free(btrfs_free_space_cachep, e);
793 goto free_cache;
794 }
795 list_add_tail(&e->list, &bitmaps);
796 }
797
798 num_entries--;
799 }
800
801 io_ctl_unmap_page(&io_ctl);
802
803 /*
804 * We add the bitmaps at the end of the entries in order that
805 * the bitmap entries are added to the cache.
806 */
807 list_for_each_entry_safe(e, n, &bitmaps, list) {
808 list_del_init(&e->list);
809 ret = io_ctl_read_bitmap(&io_ctl, e);
810 if (ret)
811 goto free_cache;
812 }
813
814 io_ctl_drop_pages(&io_ctl);
815 merge_space_tree(ctl);
816 ret = 1;
817 out:
818 io_ctl_free(&io_ctl);
819 return ret;
820 free_cache:
821 io_ctl_drop_pages(&io_ctl);
822 __btrfs_remove_free_space_cache(ctl);
823 goto out;
824 }
825
826 int load_free_space_cache(struct btrfs_fs_info *fs_info,
827 struct btrfs_block_group_cache *block_group)
828 {
829 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
830 struct btrfs_root *root = fs_info->tree_root;
831 struct inode *inode;
832 struct btrfs_path *path;
833 int ret = 0;
834 bool matched;
835 u64 used = btrfs_block_group_used(&block_group->item);
836
837 /*
838 * If this block group has been marked to be cleared for one reason or
839 * another then we can't trust the on disk cache, so just return.
840 */
841 spin_lock(&block_group->lock);
842 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
843 spin_unlock(&block_group->lock);
844 return 0;
845 }
846 spin_unlock(&block_group->lock);
847
848 path = btrfs_alloc_path();
849 if (!path)
850 return 0;
851 path->search_commit_root = 1;
852 path->skip_locking = 1;
853
854 inode = lookup_free_space_inode(root, block_group, path);
855 if (IS_ERR(inode)) {
856 btrfs_free_path(path);
857 return 0;
858 }
859
860 /* We may have converted the inode and made the cache invalid. */
861 spin_lock(&block_group->lock);
862 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
863 spin_unlock(&block_group->lock);
864 btrfs_free_path(path);
865 goto out;
866 }
867 spin_unlock(&block_group->lock);
868
869 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
870 path, block_group->key.objectid);
871 btrfs_free_path(path);
872 if (ret <= 0)
873 goto out;
874
875 spin_lock(&ctl->tree_lock);
876 matched = (ctl->free_space == (block_group->key.offset - used -
877 block_group->bytes_super));
878 spin_unlock(&ctl->tree_lock);
879
880 if (!matched) {
881 __btrfs_remove_free_space_cache(ctl);
882 btrfs_warn(fs_info, "block group %llu has wrong amount of free space",
883 block_group->key.objectid);
884 ret = -1;
885 }
886 out:
887 if (ret < 0) {
888 /* This cache is bogus, make sure it gets cleared */
889 spin_lock(&block_group->lock);
890 block_group->disk_cache_state = BTRFS_DC_CLEAR;
891 spin_unlock(&block_group->lock);
892 ret = 0;
893
894 btrfs_warn(fs_info, "failed to load free space cache for block group %llu, rebuilding it now",
895 block_group->key.objectid);
896 }
897
898 iput(inode);
899 return ret;
900 }
901
902 static noinline_for_stack
903 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
904 struct btrfs_free_space_ctl *ctl,
905 struct btrfs_block_group_cache *block_group,
906 int *entries, int *bitmaps,
907 struct list_head *bitmap_list)
908 {
909 int ret;
910 struct btrfs_free_cluster *cluster = NULL;
911 struct btrfs_free_cluster *cluster_locked = NULL;
912 struct rb_node *node = rb_first(&ctl->free_space_offset);
913 struct btrfs_trim_range *trim_entry;
914
915 /* Get the cluster for this block_group if it exists */
916 if (block_group && !list_empty(&block_group->cluster_list)) {
917 cluster = list_entry(block_group->cluster_list.next,
918 struct btrfs_free_cluster,
919 block_group_list);
920 }
921
922 if (!node && cluster) {
923 cluster_locked = cluster;
924 spin_lock(&cluster_locked->lock);
925 node = rb_first(&cluster->root);
926 cluster = NULL;
927 }
928
929 /* Write out the extent entries */
930 while (node) {
931 struct btrfs_free_space *e;
932
933 e = rb_entry(node, struct btrfs_free_space, offset_index);
934 *entries += 1;
935
936 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
937 e->bitmap);
938 if (ret)
939 goto fail;
940
941 if (e->bitmap) {
942 list_add_tail(&e->list, bitmap_list);
943 *bitmaps += 1;
944 }
945 node = rb_next(node);
946 if (!node && cluster) {
947 node = rb_first(&cluster->root);
948 cluster_locked = cluster;
949 spin_lock(&cluster_locked->lock);
950 cluster = NULL;
951 }
952 }
953 if (cluster_locked) {
954 spin_unlock(&cluster_locked->lock);
955 cluster_locked = NULL;
956 }
957
958 /*
959 * Make sure we don't miss any range that was removed from our rbtree
960 * because trimming is running. Otherwise after a umount+mount (or crash
961 * after committing the transaction) we would leak free space and get
962 * an inconsistent free space cache report from fsck.
963 */
964 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
965 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
966 trim_entry->bytes, NULL);
967 if (ret)
968 goto fail;
969 *entries += 1;
970 }
971
972 return 0;
973 fail:
974 if (cluster_locked)
975 spin_unlock(&cluster_locked->lock);
976 return -ENOSPC;
977 }
978
979 static noinline_for_stack int
980 update_cache_item(struct btrfs_trans_handle *trans,
981 struct btrfs_root *root,
982 struct inode *inode,
983 struct btrfs_path *path, u64 offset,
984 int entries, int bitmaps)
985 {
986 struct btrfs_key key;
987 struct btrfs_free_space_header *header;
988 struct extent_buffer *leaf;
989 int ret;
990
991 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
992 key.offset = offset;
993 key.type = 0;
994
995 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
996 if (ret < 0) {
997 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
998 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
999 GFP_NOFS);
1000 goto fail;
1001 }
1002 leaf = path->nodes[0];
1003 if (ret > 0) {
1004 struct btrfs_key found_key;
1005 ASSERT(path->slots[0]);
1006 path->slots[0]--;
1007 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1008 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1009 found_key.offset != offset) {
1010 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1011 inode->i_size - 1,
1012 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
1013 NULL, GFP_NOFS);
1014 btrfs_release_path(path);
1015 goto fail;
1016 }
1017 }
1018
1019 BTRFS_I(inode)->generation = trans->transid;
1020 header = btrfs_item_ptr(leaf, path->slots[0],
1021 struct btrfs_free_space_header);
1022 btrfs_set_free_space_entries(leaf, header, entries);
1023 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1024 btrfs_set_free_space_generation(leaf, header, trans->transid);
1025 btrfs_mark_buffer_dirty(leaf);
1026 btrfs_release_path(path);
1027
1028 return 0;
1029
1030 fail:
1031 return -1;
1032 }
1033
1034 static noinline_for_stack int
1035 write_pinned_extent_entries(struct btrfs_root *root,
1036 struct btrfs_block_group_cache *block_group,
1037 struct btrfs_io_ctl *io_ctl,
1038 int *entries)
1039 {
1040 u64 start, extent_start, extent_end, len;
1041 struct extent_io_tree *unpin = NULL;
1042 int ret;
1043
1044 if (!block_group)
1045 return 0;
1046
1047 /*
1048 * We want to add any pinned extents to our free space cache
1049 * so we don't leak the space
1050 *
1051 * We shouldn't have switched the pinned extents yet so this is the
1052 * right one
1053 */
1054 unpin = root->fs_info->pinned_extents;
1055
1056 start = block_group->key.objectid;
1057
1058 while (start < block_group->key.objectid + block_group->key.offset) {
1059 ret = find_first_extent_bit(unpin, start,
1060 &extent_start, &extent_end,
1061 EXTENT_DIRTY, NULL);
1062 if (ret)
1063 return 0;
1064
1065 /* This pinned extent is out of our range */
1066 if (extent_start >= block_group->key.objectid +
1067 block_group->key.offset)
1068 return 0;
1069
1070 extent_start = max(extent_start, start);
1071 extent_end = min(block_group->key.objectid +
1072 block_group->key.offset, extent_end + 1);
1073 len = extent_end - extent_start;
1074
1075 *entries += 1;
1076 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1077 if (ret)
1078 return -ENOSPC;
1079
1080 start = extent_end;
1081 }
1082
1083 return 0;
1084 }
1085
1086 static noinline_for_stack int
1087 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1088 {
1089 struct btrfs_free_space *entry, *next;
1090 int ret;
1091
1092 /* Write out the bitmaps */
1093 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1094 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1095 if (ret)
1096 return -ENOSPC;
1097 list_del_init(&entry->list);
1098 }
1099
1100 return 0;
1101 }
1102
1103 static int flush_dirty_cache(struct inode *inode)
1104 {
1105 int ret;
1106
1107 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1108 if (ret)
1109 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1110 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
1111 GFP_NOFS);
1112
1113 return ret;
1114 }
1115
1116 static void noinline_for_stack
1117 cleanup_bitmap_list(struct list_head *bitmap_list)
1118 {
1119 struct btrfs_free_space *entry, *next;
1120
1121 list_for_each_entry_safe(entry, next, bitmap_list, list)
1122 list_del_init(&entry->list);
1123 }
1124
1125 static void noinline_for_stack
1126 cleanup_write_cache_enospc(struct inode *inode,
1127 struct btrfs_io_ctl *io_ctl,
1128 struct extent_state **cached_state,
1129 struct list_head *bitmap_list)
1130 {
1131 io_ctl_drop_pages(io_ctl);
1132 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1133 i_size_read(inode) - 1, cached_state,
1134 GFP_NOFS);
1135 }
1136
1137 int btrfs_wait_cache_io(struct btrfs_root *root,
1138 struct btrfs_trans_handle *trans,
1139 struct btrfs_block_group_cache *block_group,
1140 struct btrfs_io_ctl *io_ctl,
1141 struct btrfs_path *path, u64 offset)
1142 {
1143 int ret;
1144 struct inode *inode = io_ctl->inode;
1145
1146 if (!inode)
1147 return 0;
1148
1149 if (block_group)
1150 root = root->fs_info->tree_root;
1151
1152 /* Flush the dirty pages in the cache file. */
1153 ret = flush_dirty_cache(inode);
1154 if (ret)
1155 goto out;
1156
1157 /* Update the cache item to tell everyone this cache file is valid. */
1158 ret = update_cache_item(trans, root, inode, path, offset,
1159 io_ctl->entries, io_ctl->bitmaps);
1160 out:
1161 io_ctl_free(io_ctl);
1162 if (ret) {
1163 invalidate_inode_pages2(inode->i_mapping);
1164 BTRFS_I(inode)->generation = 0;
1165 if (block_group) {
1166 #ifdef DEBUG
1167 btrfs_err(root->fs_info,
1168 "failed to write free space cache for block group %llu",
1169 block_group->key.objectid);
1170 #endif
1171 }
1172 }
1173 btrfs_update_inode(trans, root, inode);
1174
1175 if (block_group) {
1176 /* the dirty list is protected by the dirty_bgs_lock */
1177 spin_lock(&trans->transaction->dirty_bgs_lock);
1178
1179 /* the disk_cache_state is protected by the block group lock */
1180 spin_lock(&block_group->lock);
1181
1182 /*
1183 * only mark this as written if we didn't get put back on
1184 * the dirty list while waiting for IO. Otherwise our
1185 * cache state won't be right, and we won't get written again
1186 */
1187 if (!ret && list_empty(&block_group->dirty_list))
1188 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1189 else if (ret)
1190 block_group->disk_cache_state = BTRFS_DC_ERROR;
1191
1192 spin_unlock(&block_group->lock);
1193 spin_unlock(&trans->transaction->dirty_bgs_lock);
1194 io_ctl->inode = NULL;
1195 iput(inode);
1196 }
1197
1198 return ret;
1199
1200 }
1201
1202 /**
1203 * __btrfs_write_out_cache - write out cached info to an inode
1204 * @root - the root the inode belongs to
1205 * @ctl - the free space cache we are going to write out
1206 * @block_group - the block_group for this cache if it belongs to a block_group
1207 * @trans - the trans handle
1208 * @path - the path to use
1209 * @offset - the offset for the key we'll insert
1210 *
1211 * This function writes out a free space cache struct to disk for quick recovery
1212 * on mount. This will return 0 if it was successful in writing the cache out,
1213 * or an errno if it was not.
1214 */
1215 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1216 struct btrfs_free_space_ctl *ctl,
1217 struct btrfs_block_group_cache *block_group,
1218 struct btrfs_io_ctl *io_ctl,
1219 struct btrfs_trans_handle *trans,
1220 struct btrfs_path *path, u64 offset)
1221 {
1222 struct extent_state *cached_state = NULL;
1223 LIST_HEAD(bitmap_list);
1224 int entries = 0;
1225 int bitmaps = 0;
1226 int ret;
1227 int must_iput = 0;
1228
1229 if (!i_size_read(inode))
1230 return -EIO;
1231
1232 WARN_ON(io_ctl->pages);
1233 ret = io_ctl_init(io_ctl, inode, root, 1);
1234 if (ret)
1235 return ret;
1236
1237 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1238 down_write(&block_group->data_rwsem);
1239 spin_lock(&block_group->lock);
1240 if (block_group->delalloc_bytes) {
1241 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1242 spin_unlock(&block_group->lock);
1243 up_write(&block_group->data_rwsem);
1244 BTRFS_I(inode)->generation = 0;
1245 ret = 0;
1246 must_iput = 1;
1247 goto out;
1248 }
1249 spin_unlock(&block_group->lock);
1250 }
1251
1252 /* Lock all pages first so we can lock the extent safely. */
1253 ret = io_ctl_prepare_pages(io_ctl, inode, 0);
1254 if (ret)
1255 goto out;
1256
1257 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1258 &cached_state);
1259
1260 io_ctl_set_generation(io_ctl, trans->transid);
1261
1262 mutex_lock(&ctl->cache_writeout_mutex);
1263 /* Write out the extent entries in the free space cache */
1264 spin_lock(&ctl->tree_lock);
1265 ret = write_cache_extent_entries(io_ctl, ctl,
1266 block_group, &entries, &bitmaps,
1267 &bitmap_list);
1268 if (ret)
1269 goto out_nospc_locked;
1270
1271 /*
1272 * Some spaces that are freed in the current transaction are pinned,
1273 * they will be added into free space cache after the transaction is
1274 * committed, we shouldn't lose them.
1275 *
1276 * If this changes while we are working we'll get added back to
1277 * the dirty list and redo it. No locking needed
1278 */
1279 ret = write_pinned_extent_entries(root, block_group, io_ctl, &entries);
1280 if (ret)
1281 goto out_nospc_locked;
1282
1283 /*
1284 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1285 * locked while doing it because a concurrent trim can be manipulating
1286 * or freeing the bitmap.
1287 */
1288 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1289 spin_unlock(&ctl->tree_lock);
1290 mutex_unlock(&ctl->cache_writeout_mutex);
1291 if (ret)
1292 goto out_nospc;
1293
1294 /* Zero out the rest of the pages just to make sure */
1295 io_ctl_zero_remaining_pages(io_ctl);
1296
1297 /* Everything is written out, now we dirty the pages in the file. */
1298 ret = btrfs_dirty_pages(root, inode, io_ctl->pages, io_ctl->num_pages,
1299 0, i_size_read(inode), &cached_state);
1300 if (ret)
1301 goto out_nospc;
1302
1303 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1304 up_write(&block_group->data_rwsem);
1305 /*
1306 * Release the pages and unlock the extent, we will flush
1307 * them out later
1308 */
1309 io_ctl_drop_pages(io_ctl);
1310
1311 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1312 i_size_read(inode) - 1, &cached_state, GFP_NOFS);
1313
1314 /*
1315 * at this point the pages are under IO and we're happy,
1316 * The caller is responsible for waiting on them and updating the
1317 * the cache and the inode
1318 */
1319 io_ctl->entries = entries;
1320 io_ctl->bitmaps = bitmaps;
1321
1322 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1323 if (ret)
1324 goto out;
1325
1326 return 0;
1327
1328 out:
1329 io_ctl->inode = NULL;
1330 io_ctl_free(io_ctl);
1331 if (ret) {
1332 invalidate_inode_pages2(inode->i_mapping);
1333 BTRFS_I(inode)->generation = 0;
1334 }
1335 btrfs_update_inode(trans, root, inode);
1336 if (must_iput)
1337 iput(inode);
1338 return ret;
1339
1340 out_nospc_locked:
1341 cleanup_bitmap_list(&bitmap_list);
1342 spin_unlock(&ctl->tree_lock);
1343 mutex_unlock(&ctl->cache_writeout_mutex);
1344
1345 out_nospc:
1346 cleanup_write_cache_enospc(inode, io_ctl, &cached_state, &bitmap_list);
1347
1348 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1349 up_write(&block_group->data_rwsem);
1350
1351 goto out;
1352 }
1353
1354 int btrfs_write_out_cache(struct btrfs_root *root,
1355 struct btrfs_trans_handle *trans,
1356 struct btrfs_block_group_cache *block_group,
1357 struct btrfs_path *path)
1358 {
1359 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1360 struct inode *inode;
1361 int ret = 0;
1362
1363 root = root->fs_info->tree_root;
1364
1365 spin_lock(&block_group->lock);
1366 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1367 spin_unlock(&block_group->lock);
1368 return 0;
1369 }
1370 spin_unlock(&block_group->lock);
1371
1372 inode = lookup_free_space_inode(root, block_group, path);
1373 if (IS_ERR(inode))
1374 return 0;
1375
1376 ret = __btrfs_write_out_cache(root, inode, ctl, block_group,
1377 &block_group->io_ctl, trans,
1378 path, block_group->key.objectid);
1379 if (ret) {
1380 #ifdef DEBUG
1381 btrfs_err(root->fs_info,
1382 "failed to write free space cache for block group %llu",
1383 block_group->key.objectid);
1384 #endif
1385 spin_lock(&block_group->lock);
1386 block_group->disk_cache_state = BTRFS_DC_ERROR;
1387 spin_unlock(&block_group->lock);
1388
1389 block_group->io_ctl.inode = NULL;
1390 iput(inode);
1391 }
1392
1393 /*
1394 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1395 * to wait for IO and put the inode
1396 */
1397
1398 return ret;
1399 }
1400
1401 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1402 u64 offset)
1403 {
1404 ASSERT(offset >= bitmap_start);
1405 offset -= bitmap_start;
1406 return (unsigned long)(div_u64(offset, unit));
1407 }
1408
1409 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1410 {
1411 return (unsigned long)(div_u64(bytes, unit));
1412 }
1413
1414 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1415 u64 offset)
1416 {
1417 u64 bitmap_start;
1418 u32 bytes_per_bitmap;
1419
1420 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1421 bitmap_start = offset - ctl->start;
1422 bitmap_start = div_u64(bitmap_start, bytes_per_bitmap);
1423 bitmap_start *= bytes_per_bitmap;
1424 bitmap_start += ctl->start;
1425
1426 return bitmap_start;
1427 }
1428
1429 static int tree_insert_offset(struct rb_root *root, u64 offset,
1430 struct rb_node *node, int bitmap)
1431 {
1432 struct rb_node **p = &root->rb_node;
1433 struct rb_node *parent = NULL;
1434 struct btrfs_free_space *info;
1435
1436 while (*p) {
1437 parent = *p;
1438 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1439
1440 if (offset < info->offset) {
1441 p = &(*p)->rb_left;
1442 } else if (offset > info->offset) {
1443 p = &(*p)->rb_right;
1444 } else {
1445 /*
1446 * we could have a bitmap entry and an extent entry
1447 * share the same offset. If this is the case, we want
1448 * the extent entry to always be found first if we do a
1449 * linear search through the tree, since we want to have
1450 * the quickest allocation time, and allocating from an
1451 * extent is faster than allocating from a bitmap. So
1452 * if we're inserting a bitmap and we find an entry at
1453 * this offset, we want to go right, or after this entry
1454 * logically. If we are inserting an extent and we've
1455 * found a bitmap, we want to go left, or before
1456 * logically.
1457 */
1458 if (bitmap) {
1459 if (info->bitmap) {
1460 WARN_ON_ONCE(1);
1461 return -EEXIST;
1462 }
1463 p = &(*p)->rb_right;
1464 } else {
1465 if (!info->bitmap) {
1466 WARN_ON_ONCE(1);
1467 return -EEXIST;
1468 }
1469 p = &(*p)->rb_left;
1470 }
1471 }
1472 }
1473
1474 rb_link_node(node, parent, p);
1475 rb_insert_color(node, root);
1476
1477 return 0;
1478 }
1479
1480 /*
1481 * searches the tree for the given offset.
1482 *
1483 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1484 * want a section that has at least bytes size and comes at or after the given
1485 * offset.
1486 */
1487 static struct btrfs_free_space *
1488 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1489 u64 offset, int bitmap_only, int fuzzy)
1490 {
1491 struct rb_node *n = ctl->free_space_offset.rb_node;
1492 struct btrfs_free_space *entry, *prev = NULL;
1493
1494 /* find entry that is closest to the 'offset' */
1495 while (1) {
1496 if (!n) {
1497 entry = NULL;
1498 break;
1499 }
1500
1501 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1502 prev = entry;
1503
1504 if (offset < entry->offset)
1505 n = n->rb_left;
1506 else if (offset > entry->offset)
1507 n = n->rb_right;
1508 else
1509 break;
1510 }
1511
1512 if (bitmap_only) {
1513 if (!entry)
1514 return NULL;
1515 if (entry->bitmap)
1516 return entry;
1517
1518 /*
1519 * bitmap entry and extent entry may share same offset,
1520 * in that case, bitmap entry comes after extent entry.
1521 */
1522 n = rb_next(n);
1523 if (!n)
1524 return NULL;
1525 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1526 if (entry->offset != offset)
1527 return NULL;
1528
1529 WARN_ON(!entry->bitmap);
1530 return entry;
1531 } else if (entry) {
1532 if (entry->bitmap) {
1533 /*
1534 * if previous extent entry covers the offset,
1535 * we should return it instead of the bitmap entry
1536 */
1537 n = rb_prev(&entry->offset_index);
1538 if (n) {
1539 prev = rb_entry(n, struct btrfs_free_space,
1540 offset_index);
1541 if (!prev->bitmap &&
1542 prev->offset + prev->bytes > offset)
1543 entry = prev;
1544 }
1545 }
1546 return entry;
1547 }
1548
1549 if (!prev)
1550 return NULL;
1551
1552 /* find last entry before the 'offset' */
1553 entry = prev;
1554 if (entry->offset > offset) {
1555 n = rb_prev(&entry->offset_index);
1556 if (n) {
1557 entry = rb_entry(n, struct btrfs_free_space,
1558 offset_index);
1559 ASSERT(entry->offset <= offset);
1560 } else {
1561 if (fuzzy)
1562 return entry;
1563 else
1564 return NULL;
1565 }
1566 }
1567
1568 if (entry->bitmap) {
1569 n = rb_prev(&entry->offset_index);
1570 if (n) {
1571 prev = rb_entry(n, struct btrfs_free_space,
1572 offset_index);
1573 if (!prev->bitmap &&
1574 prev->offset + prev->bytes > offset)
1575 return prev;
1576 }
1577 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1578 return entry;
1579 } else if (entry->offset + entry->bytes > offset)
1580 return entry;
1581
1582 if (!fuzzy)
1583 return NULL;
1584
1585 while (1) {
1586 if (entry->bitmap) {
1587 if (entry->offset + BITS_PER_BITMAP *
1588 ctl->unit > offset)
1589 break;
1590 } else {
1591 if (entry->offset + entry->bytes > offset)
1592 break;
1593 }
1594
1595 n = rb_next(&entry->offset_index);
1596 if (!n)
1597 return NULL;
1598 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1599 }
1600 return entry;
1601 }
1602
1603 static inline void
1604 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1605 struct btrfs_free_space *info)
1606 {
1607 rb_erase(&info->offset_index, &ctl->free_space_offset);
1608 ctl->free_extents--;
1609 }
1610
1611 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1612 struct btrfs_free_space *info)
1613 {
1614 __unlink_free_space(ctl, info);
1615 ctl->free_space -= info->bytes;
1616 }
1617
1618 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1619 struct btrfs_free_space *info)
1620 {
1621 int ret = 0;
1622
1623 ASSERT(info->bytes || info->bitmap);
1624 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1625 &info->offset_index, (info->bitmap != NULL));
1626 if (ret)
1627 return ret;
1628
1629 ctl->free_space += info->bytes;
1630 ctl->free_extents++;
1631 return ret;
1632 }
1633
1634 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1635 {
1636 struct btrfs_block_group_cache *block_group = ctl->private;
1637 u64 max_bytes;
1638 u64 bitmap_bytes;
1639 u64 extent_bytes;
1640 u64 size = block_group->key.offset;
1641 u32 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1642 u32 max_bitmaps = div_u64(size + bytes_per_bg - 1, bytes_per_bg);
1643
1644 max_bitmaps = max_t(u32, max_bitmaps, 1);
1645
1646 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1647
1648 /*
1649 * The goal is to keep the total amount of memory used per 1gb of space
1650 * at or below 32k, so we need to adjust how much memory we allow to be
1651 * used by extent based free space tracking
1652 */
1653 if (size < SZ_1G)
1654 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1655 else
1656 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1657
1658 /*
1659 * we want to account for 1 more bitmap than what we have so we can make
1660 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1661 * we add more bitmaps.
1662 */
1663 bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE;
1664
1665 if (bitmap_bytes >= max_bytes) {
1666 ctl->extents_thresh = 0;
1667 return;
1668 }
1669
1670 /*
1671 * we want the extent entry threshold to always be at most 1/2 the max
1672 * bytes we can have, or whatever is less than that.
1673 */
1674 extent_bytes = max_bytes - bitmap_bytes;
1675 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1676
1677 ctl->extents_thresh =
1678 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1679 }
1680
1681 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1682 struct btrfs_free_space *info,
1683 u64 offset, u64 bytes)
1684 {
1685 unsigned long start, count;
1686
1687 start = offset_to_bit(info->offset, ctl->unit, offset);
1688 count = bytes_to_bits(bytes, ctl->unit);
1689 ASSERT(start + count <= BITS_PER_BITMAP);
1690
1691 bitmap_clear(info->bitmap, start, count);
1692
1693 info->bytes -= bytes;
1694 }
1695
1696 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1697 struct btrfs_free_space *info, u64 offset,
1698 u64 bytes)
1699 {
1700 __bitmap_clear_bits(ctl, info, offset, bytes);
1701 ctl->free_space -= bytes;
1702 }
1703
1704 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1705 struct btrfs_free_space *info, u64 offset,
1706 u64 bytes)
1707 {
1708 unsigned long start, count;
1709
1710 start = offset_to_bit(info->offset, ctl->unit, offset);
1711 count = bytes_to_bits(bytes, ctl->unit);
1712 ASSERT(start + count <= BITS_PER_BITMAP);
1713
1714 bitmap_set(info->bitmap, start, count);
1715
1716 info->bytes += bytes;
1717 ctl->free_space += bytes;
1718 }
1719
1720 /*
1721 * If we can not find suitable extent, we will use bytes to record
1722 * the size of the max extent.
1723 */
1724 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1725 struct btrfs_free_space *bitmap_info, u64 *offset,
1726 u64 *bytes, bool for_alloc)
1727 {
1728 unsigned long found_bits = 0;
1729 unsigned long max_bits = 0;
1730 unsigned long bits, i;
1731 unsigned long next_zero;
1732 unsigned long extent_bits;
1733
1734 /*
1735 * Skip searching the bitmap if we don't have a contiguous section that
1736 * is large enough for this allocation.
1737 */
1738 if (for_alloc &&
1739 bitmap_info->max_extent_size &&
1740 bitmap_info->max_extent_size < *bytes) {
1741 *bytes = bitmap_info->max_extent_size;
1742 return -1;
1743 }
1744
1745 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1746 max_t(u64, *offset, bitmap_info->offset));
1747 bits = bytes_to_bits(*bytes, ctl->unit);
1748
1749 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1750 if (for_alloc && bits == 1) {
1751 found_bits = 1;
1752 break;
1753 }
1754 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1755 BITS_PER_BITMAP, i);
1756 extent_bits = next_zero - i;
1757 if (extent_bits >= bits) {
1758 found_bits = extent_bits;
1759 break;
1760 } else if (extent_bits > max_bits) {
1761 max_bits = extent_bits;
1762 }
1763 i = next_zero;
1764 }
1765
1766 if (found_bits) {
1767 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1768 *bytes = (u64)(found_bits) * ctl->unit;
1769 return 0;
1770 }
1771
1772 *bytes = (u64)(max_bits) * ctl->unit;
1773 bitmap_info->max_extent_size = *bytes;
1774 return -1;
1775 }
1776
1777 /* Cache the size of the max extent in bytes */
1778 static struct btrfs_free_space *
1779 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1780 unsigned long align, u64 *max_extent_size)
1781 {
1782 struct btrfs_free_space *entry;
1783 struct rb_node *node;
1784 u64 tmp;
1785 u64 align_off;
1786 int ret;
1787
1788 if (!ctl->free_space_offset.rb_node)
1789 goto out;
1790
1791 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1792 if (!entry)
1793 goto out;
1794
1795 for (node = &entry->offset_index; node; node = rb_next(node)) {
1796 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1797 if (entry->bytes < *bytes) {
1798 if (entry->bytes > *max_extent_size)
1799 *max_extent_size = entry->bytes;
1800 continue;
1801 }
1802
1803 /* make sure the space returned is big enough
1804 * to match our requested alignment
1805 */
1806 if (*bytes >= align) {
1807 tmp = entry->offset - ctl->start + align - 1;
1808 tmp = div64_u64(tmp, align);
1809 tmp = tmp * align + ctl->start;
1810 align_off = tmp - entry->offset;
1811 } else {
1812 align_off = 0;
1813 tmp = entry->offset;
1814 }
1815
1816 if (entry->bytes < *bytes + align_off) {
1817 if (entry->bytes > *max_extent_size)
1818 *max_extent_size = entry->bytes;
1819 continue;
1820 }
1821
1822 if (entry->bitmap) {
1823 u64 size = *bytes;
1824
1825 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1826 if (!ret) {
1827 *offset = tmp;
1828 *bytes = size;
1829 return entry;
1830 } else if (size > *max_extent_size) {
1831 *max_extent_size = size;
1832 }
1833 continue;
1834 }
1835
1836 *offset = tmp;
1837 *bytes = entry->bytes - align_off;
1838 return entry;
1839 }
1840 out:
1841 return NULL;
1842 }
1843
1844 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1845 struct btrfs_free_space *info, u64 offset)
1846 {
1847 info->offset = offset_to_bitmap(ctl, offset);
1848 info->bytes = 0;
1849 INIT_LIST_HEAD(&info->list);
1850 link_free_space(ctl, info);
1851 ctl->total_bitmaps++;
1852
1853 ctl->op->recalc_thresholds(ctl);
1854 }
1855
1856 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1857 struct btrfs_free_space *bitmap_info)
1858 {
1859 unlink_free_space(ctl, bitmap_info);
1860 kfree(bitmap_info->bitmap);
1861 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1862 ctl->total_bitmaps--;
1863 ctl->op->recalc_thresholds(ctl);
1864 }
1865
1866 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1867 struct btrfs_free_space *bitmap_info,
1868 u64 *offset, u64 *bytes)
1869 {
1870 u64 end;
1871 u64 search_start, search_bytes;
1872 int ret;
1873
1874 again:
1875 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1876
1877 /*
1878 * We need to search for bits in this bitmap. We could only cover some
1879 * of the extent in this bitmap thanks to how we add space, so we need
1880 * to search for as much as it as we can and clear that amount, and then
1881 * go searching for the next bit.
1882 */
1883 search_start = *offset;
1884 search_bytes = ctl->unit;
1885 search_bytes = min(search_bytes, end - search_start + 1);
1886 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1887 false);
1888 if (ret < 0 || search_start != *offset)
1889 return -EINVAL;
1890
1891 /* We may have found more bits than what we need */
1892 search_bytes = min(search_bytes, *bytes);
1893
1894 /* Cannot clear past the end of the bitmap */
1895 search_bytes = min(search_bytes, end - search_start + 1);
1896
1897 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1898 *offset += search_bytes;
1899 *bytes -= search_bytes;
1900
1901 if (*bytes) {
1902 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1903 if (!bitmap_info->bytes)
1904 free_bitmap(ctl, bitmap_info);
1905
1906 /*
1907 * no entry after this bitmap, but we still have bytes to
1908 * remove, so something has gone wrong.
1909 */
1910 if (!next)
1911 return -EINVAL;
1912
1913 bitmap_info = rb_entry(next, struct btrfs_free_space,
1914 offset_index);
1915
1916 /*
1917 * if the next entry isn't a bitmap we need to return to let the
1918 * extent stuff do its work.
1919 */
1920 if (!bitmap_info->bitmap)
1921 return -EAGAIN;
1922
1923 /*
1924 * Ok the next item is a bitmap, but it may not actually hold
1925 * the information for the rest of this free space stuff, so
1926 * look for it, and if we don't find it return so we can try
1927 * everything over again.
1928 */
1929 search_start = *offset;
1930 search_bytes = ctl->unit;
1931 ret = search_bitmap(ctl, bitmap_info, &search_start,
1932 &search_bytes, false);
1933 if (ret < 0 || search_start != *offset)
1934 return -EAGAIN;
1935
1936 goto again;
1937 } else if (!bitmap_info->bytes)
1938 free_bitmap(ctl, bitmap_info);
1939
1940 return 0;
1941 }
1942
1943 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1944 struct btrfs_free_space *info, u64 offset,
1945 u64 bytes)
1946 {
1947 u64 bytes_to_set = 0;
1948 u64 end;
1949
1950 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1951
1952 bytes_to_set = min(end - offset, bytes);
1953
1954 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1955
1956 /*
1957 * We set some bytes, we have no idea what the max extent size is
1958 * anymore.
1959 */
1960 info->max_extent_size = 0;
1961
1962 return bytes_to_set;
1963
1964 }
1965
1966 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1967 struct btrfs_free_space *info)
1968 {
1969 struct btrfs_block_group_cache *block_group = ctl->private;
1970 bool forced = false;
1971
1972 #ifdef CONFIG_BTRFS_DEBUG
1973 if (btrfs_should_fragment_free_space(block_group->fs_info->extent_root,
1974 block_group))
1975 forced = true;
1976 #endif
1977
1978 /*
1979 * If we are below the extents threshold then we can add this as an
1980 * extent, and don't have to deal with the bitmap
1981 */
1982 if (!forced && ctl->free_extents < ctl->extents_thresh) {
1983 /*
1984 * If this block group has some small extents we don't want to
1985 * use up all of our free slots in the cache with them, we want
1986 * to reserve them to larger extents, however if we have plent
1987 * of cache left then go ahead an dadd them, no sense in adding
1988 * the overhead of a bitmap if we don't have to.
1989 */
1990 if (info->bytes <= block_group->sectorsize * 4) {
1991 if (ctl->free_extents * 2 <= ctl->extents_thresh)
1992 return false;
1993 } else {
1994 return false;
1995 }
1996 }
1997
1998 /*
1999 * The original block groups from mkfs can be really small, like 8
2000 * megabytes, so don't bother with a bitmap for those entries. However
2001 * some block groups can be smaller than what a bitmap would cover but
2002 * are still large enough that they could overflow the 32k memory limit,
2003 * so allow those block groups to still be allowed to have a bitmap
2004 * entry.
2005 */
2006 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
2007 return false;
2008
2009 return true;
2010 }
2011
2012 static const struct btrfs_free_space_op free_space_op = {
2013 .recalc_thresholds = recalculate_thresholds,
2014 .use_bitmap = use_bitmap,
2015 };
2016
2017 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2018 struct btrfs_free_space *info)
2019 {
2020 struct btrfs_free_space *bitmap_info;
2021 struct btrfs_block_group_cache *block_group = NULL;
2022 int added = 0;
2023 u64 bytes, offset, bytes_added;
2024 int ret;
2025
2026 bytes = info->bytes;
2027 offset = info->offset;
2028
2029 if (!ctl->op->use_bitmap(ctl, info))
2030 return 0;
2031
2032 if (ctl->op == &free_space_op)
2033 block_group = ctl->private;
2034 again:
2035 /*
2036 * Since we link bitmaps right into the cluster we need to see if we
2037 * have a cluster here, and if so and it has our bitmap we need to add
2038 * the free space to that bitmap.
2039 */
2040 if (block_group && !list_empty(&block_group->cluster_list)) {
2041 struct btrfs_free_cluster *cluster;
2042 struct rb_node *node;
2043 struct btrfs_free_space *entry;
2044
2045 cluster = list_entry(block_group->cluster_list.next,
2046 struct btrfs_free_cluster,
2047 block_group_list);
2048 spin_lock(&cluster->lock);
2049 node = rb_first(&cluster->root);
2050 if (!node) {
2051 spin_unlock(&cluster->lock);
2052 goto no_cluster_bitmap;
2053 }
2054
2055 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2056 if (!entry->bitmap) {
2057 spin_unlock(&cluster->lock);
2058 goto no_cluster_bitmap;
2059 }
2060
2061 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2062 bytes_added = add_bytes_to_bitmap(ctl, entry,
2063 offset, bytes);
2064 bytes -= bytes_added;
2065 offset += bytes_added;
2066 }
2067 spin_unlock(&cluster->lock);
2068 if (!bytes) {
2069 ret = 1;
2070 goto out;
2071 }
2072 }
2073
2074 no_cluster_bitmap:
2075 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2076 1, 0);
2077 if (!bitmap_info) {
2078 ASSERT(added == 0);
2079 goto new_bitmap;
2080 }
2081
2082 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
2083 bytes -= bytes_added;
2084 offset += bytes_added;
2085 added = 0;
2086
2087 if (!bytes) {
2088 ret = 1;
2089 goto out;
2090 } else
2091 goto again;
2092
2093 new_bitmap:
2094 if (info && info->bitmap) {
2095 add_new_bitmap(ctl, info, offset);
2096 added = 1;
2097 info = NULL;
2098 goto again;
2099 } else {
2100 spin_unlock(&ctl->tree_lock);
2101
2102 /* no pre-allocated info, allocate a new one */
2103 if (!info) {
2104 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2105 GFP_NOFS);
2106 if (!info) {
2107 spin_lock(&ctl->tree_lock);
2108 ret = -ENOMEM;
2109 goto out;
2110 }
2111 }
2112
2113 /* allocate the bitmap */
2114 info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
2115 spin_lock(&ctl->tree_lock);
2116 if (!info->bitmap) {
2117 ret = -ENOMEM;
2118 goto out;
2119 }
2120 goto again;
2121 }
2122
2123 out:
2124 if (info) {
2125 if (info->bitmap)
2126 kfree(info->bitmap);
2127 kmem_cache_free(btrfs_free_space_cachep, info);
2128 }
2129
2130 return ret;
2131 }
2132
2133 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2134 struct btrfs_free_space *info, bool update_stat)
2135 {
2136 struct btrfs_free_space *left_info;
2137 struct btrfs_free_space *right_info;
2138 bool merged = false;
2139 u64 offset = info->offset;
2140 u64 bytes = info->bytes;
2141
2142 /*
2143 * first we want to see if there is free space adjacent to the range we
2144 * are adding, if there is remove that struct and add a new one to
2145 * cover the entire range
2146 */
2147 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2148 if (right_info && rb_prev(&right_info->offset_index))
2149 left_info = rb_entry(rb_prev(&right_info->offset_index),
2150 struct btrfs_free_space, offset_index);
2151 else
2152 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2153
2154 if (right_info && !right_info->bitmap) {
2155 if (update_stat)
2156 unlink_free_space(ctl, right_info);
2157 else
2158 __unlink_free_space(ctl, right_info);
2159 info->bytes += right_info->bytes;
2160 kmem_cache_free(btrfs_free_space_cachep, right_info);
2161 merged = true;
2162 }
2163
2164 if (left_info && !left_info->bitmap &&
2165 left_info->offset + left_info->bytes == offset) {
2166 if (update_stat)
2167 unlink_free_space(ctl, left_info);
2168 else
2169 __unlink_free_space(ctl, left_info);
2170 info->offset = left_info->offset;
2171 info->bytes += left_info->bytes;
2172 kmem_cache_free(btrfs_free_space_cachep, left_info);
2173 merged = true;
2174 }
2175
2176 return merged;
2177 }
2178
2179 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2180 struct btrfs_free_space *info,
2181 bool update_stat)
2182 {
2183 struct btrfs_free_space *bitmap;
2184 unsigned long i;
2185 unsigned long j;
2186 const u64 end = info->offset + info->bytes;
2187 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2188 u64 bytes;
2189
2190 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2191 if (!bitmap)
2192 return false;
2193
2194 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2195 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2196 if (j == i)
2197 return false;
2198 bytes = (j - i) * ctl->unit;
2199 info->bytes += bytes;
2200
2201 if (update_stat)
2202 bitmap_clear_bits(ctl, bitmap, end, bytes);
2203 else
2204 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2205
2206 if (!bitmap->bytes)
2207 free_bitmap(ctl, bitmap);
2208
2209 return true;
2210 }
2211
2212 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2213 struct btrfs_free_space *info,
2214 bool update_stat)
2215 {
2216 struct btrfs_free_space *bitmap;
2217 u64 bitmap_offset;
2218 unsigned long i;
2219 unsigned long j;
2220 unsigned long prev_j;
2221 u64 bytes;
2222
2223 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2224 /* If we're on a boundary, try the previous logical bitmap. */
2225 if (bitmap_offset == info->offset) {
2226 if (info->offset == 0)
2227 return false;
2228 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2229 }
2230
2231 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2232 if (!bitmap)
2233 return false;
2234
2235 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2236 j = 0;
2237 prev_j = (unsigned long)-1;
2238 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2239 if (j > i)
2240 break;
2241 prev_j = j;
2242 }
2243 if (prev_j == i)
2244 return false;
2245
2246 if (prev_j == (unsigned long)-1)
2247 bytes = (i + 1) * ctl->unit;
2248 else
2249 bytes = (i - prev_j) * ctl->unit;
2250
2251 info->offset -= bytes;
2252 info->bytes += bytes;
2253
2254 if (update_stat)
2255 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2256 else
2257 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2258
2259 if (!bitmap->bytes)
2260 free_bitmap(ctl, bitmap);
2261
2262 return true;
2263 }
2264
2265 /*
2266 * We prefer always to allocate from extent entries, both for clustered and
2267 * non-clustered allocation requests. So when attempting to add a new extent
2268 * entry, try to see if there's adjacent free space in bitmap entries, and if
2269 * there is, migrate that space from the bitmaps to the extent.
2270 * Like this we get better chances of satisfying space allocation requests
2271 * because we attempt to satisfy them based on a single cache entry, and never
2272 * on 2 or more entries - even if the entries represent a contiguous free space
2273 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2274 * ends).
2275 */
2276 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2277 struct btrfs_free_space *info,
2278 bool update_stat)
2279 {
2280 /*
2281 * Only work with disconnected entries, as we can change their offset,
2282 * and must be extent entries.
2283 */
2284 ASSERT(!info->bitmap);
2285 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2286
2287 if (ctl->total_bitmaps > 0) {
2288 bool stole_end;
2289 bool stole_front = false;
2290
2291 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2292 if (ctl->total_bitmaps > 0)
2293 stole_front = steal_from_bitmap_to_front(ctl, info,
2294 update_stat);
2295
2296 if (stole_end || stole_front)
2297 try_merge_free_space(ctl, info, update_stat);
2298 }
2299 }
2300
2301 int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl,
2302 u64 offset, u64 bytes)
2303 {
2304 struct btrfs_free_space *info;
2305 int ret = 0;
2306
2307 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2308 if (!info)
2309 return -ENOMEM;
2310
2311 info->offset = offset;
2312 info->bytes = bytes;
2313 RB_CLEAR_NODE(&info->offset_index);
2314
2315 spin_lock(&ctl->tree_lock);
2316
2317 if (try_merge_free_space(ctl, info, true))
2318 goto link;
2319
2320 /*
2321 * There was no extent directly to the left or right of this new
2322 * extent then we know we're going to have to allocate a new extent, so
2323 * before we do that see if we need to drop this into a bitmap
2324 */
2325 ret = insert_into_bitmap(ctl, info);
2326 if (ret < 0) {
2327 goto out;
2328 } else if (ret) {
2329 ret = 0;
2330 goto out;
2331 }
2332 link:
2333 /*
2334 * Only steal free space from adjacent bitmaps if we're sure we're not
2335 * going to add the new free space to existing bitmap entries - because
2336 * that would mean unnecessary work that would be reverted. Therefore
2337 * attempt to steal space from bitmaps if we're adding an extent entry.
2338 */
2339 steal_from_bitmap(ctl, info, true);
2340
2341 ret = link_free_space(ctl, info);
2342 if (ret)
2343 kmem_cache_free(btrfs_free_space_cachep, info);
2344 out:
2345 spin_unlock(&ctl->tree_lock);
2346
2347 if (ret) {
2348 printk(KERN_CRIT "BTRFS: unable to add free space :%d\n", ret);
2349 ASSERT(ret != -EEXIST);
2350 }
2351
2352 return ret;
2353 }
2354
2355 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2356 u64 offset, u64 bytes)
2357 {
2358 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2359 struct btrfs_free_space *info;
2360 int ret;
2361 bool re_search = false;
2362
2363 spin_lock(&ctl->tree_lock);
2364
2365 again:
2366 ret = 0;
2367 if (!bytes)
2368 goto out_lock;
2369
2370 info = tree_search_offset(ctl, offset, 0, 0);
2371 if (!info) {
2372 /*
2373 * oops didn't find an extent that matched the space we wanted
2374 * to remove, look for a bitmap instead
2375 */
2376 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2377 1, 0);
2378 if (!info) {
2379 /*
2380 * If we found a partial bit of our free space in a
2381 * bitmap but then couldn't find the other part this may
2382 * be a problem, so WARN about it.
2383 */
2384 WARN_ON(re_search);
2385 goto out_lock;
2386 }
2387 }
2388
2389 re_search = false;
2390 if (!info->bitmap) {
2391 unlink_free_space(ctl, info);
2392 if (offset == info->offset) {
2393 u64 to_free = min(bytes, info->bytes);
2394
2395 info->bytes -= to_free;
2396 info->offset += to_free;
2397 if (info->bytes) {
2398 ret = link_free_space(ctl, info);
2399 WARN_ON(ret);
2400 } else {
2401 kmem_cache_free(btrfs_free_space_cachep, info);
2402 }
2403
2404 offset += to_free;
2405 bytes -= to_free;
2406 goto again;
2407 } else {
2408 u64 old_end = info->bytes + info->offset;
2409
2410 info->bytes = offset - info->offset;
2411 ret = link_free_space(ctl, info);
2412 WARN_ON(ret);
2413 if (ret)
2414 goto out_lock;
2415
2416 /* Not enough bytes in this entry to satisfy us */
2417 if (old_end < offset + bytes) {
2418 bytes -= old_end - offset;
2419 offset = old_end;
2420 goto again;
2421 } else if (old_end == offset + bytes) {
2422 /* all done */
2423 goto out_lock;
2424 }
2425 spin_unlock(&ctl->tree_lock);
2426
2427 ret = btrfs_add_free_space(block_group, offset + bytes,
2428 old_end - (offset + bytes));
2429 WARN_ON(ret);
2430 goto out;
2431 }
2432 }
2433
2434 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2435 if (ret == -EAGAIN) {
2436 re_search = true;
2437 goto again;
2438 }
2439 out_lock:
2440 spin_unlock(&ctl->tree_lock);
2441 out:
2442 return ret;
2443 }
2444
2445 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2446 u64 bytes)
2447 {
2448 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2449 struct btrfs_free_space *info;
2450 struct rb_node *n;
2451 int count = 0;
2452
2453 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2454 info = rb_entry(n, struct btrfs_free_space, offset_index);
2455 if (info->bytes >= bytes && !block_group->ro)
2456 count++;
2457 btrfs_crit(block_group->fs_info,
2458 "entry offset %llu, bytes %llu, bitmap %s",
2459 info->offset, info->bytes,
2460 (info->bitmap) ? "yes" : "no");
2461 }
2462 btrfs_info(block_group->fs_info, "block group has cluster?: %s",
2463 list_empty(&block_group->cluster_list) ? "no" : "yes");
2464 btrfs_info(block_group->fs_info,
2465 "%d blocks of free space at or bigger than bytes is", count);
2466 }
2467
2468 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2469 {
2470 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2471
2472 spin_lock_init(&ctl->tree_lock);
2473 ctl->unit = block_group->sectorsize;
2474 ctl->start = block_group->key.objectid;
2475 ctl->private = block_group;
2476 ctl->op = &free_space_op;
2477 INIT_LIST_HEAD(&ctl->trimming_ranges);
2478 mutex_init(&ctl->cache_writeout_mutex);
2479
2480 /*
2481 * we only want to have 32k of ram per block group for keeping
2482 * track of free space, and if we pass 1/2 of that we want to
2483 * start converting things over to using bitmaps
2484 */
2485 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2486 }
2487
2488 /*
2489 * for a given cluster, put all of its extents back into the free
2490 * space cache. If the block group passed doesn't match the block group
2491 * pointed to by the cluster, someone else raced in and freed the
2492 * cluster already. In that case, we just return without changing anything
2493 */
2494 static int
2495 __btrfs_return_cluster_to_free_space(
2496 struct btrfs_block_group_cache *block_group,
2497 struct btrfs_free_cluster *cluster)
2498 {
2499 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2500 struct btrfs_free_space *entry;
2501 struct rb_node *node;
2502
2503 spin_lock(&cluster->lock);
2504 if (cluster->block_group != block_group)
2505 goto out;
2506
2507 cluster->block_group = NULL;
2508 cluster->window_start = 0;
2509 list_del_init(&cluster->block_group_list);
2510
2511 node = rb_first(&cluster->root);
2512 while (node) {
2513 bool bitmap;
2514
2515 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2516 node = rb_next(&entry->offset_index);
2517 rb_erase(&entry->offset_index, &cluster->root);
2518 RB_CLEAR_NODE(&entry->offset_index);
2519
2520 bitmap = (entry->bitmap != NULL);
2521 if (!bitmap) {
2522 try_merge_free_space(ctl, entry, false);
2523 steal_from_bitmap(ctl, entry, false);
2524 }
2525 tree_insert_offset(&ctl->free_space_offset,
2526 entry->offset, &entry->offset_index, bitmap);
2527 }
2528 cluster->root = RB_ROOT;
2529
2530 out:
2531 spin_unlock(&cluster->lock);
2532 btrfs_put_block_group(block_group);
2533 return 0;
2534 }
2535
2536 static void __btrfs_remove_free_space_cache_locked(
2537 struct btrfs_free_space_ctl *ctl)
2538 {
2539 struct btrfs_free_space *info;
2540 struct rb_node *node;
2541
2542 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2543 info = rb_entry(node, struct btrfs_free_space, offset_index);
2544 if (!info->bitmap) {
2545 unlink_free_space(ctl, info);
2546 kmem_cache_free(btrfs_free_space_cachep, info);
2547 } else {
2548 free_bitmap(ctl, info);
2549 }
2550
2551 cond_resched_lock(&ctl->tree_lock);
2552 }
2553 }
2554
2555 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2556 {
2557 spin_lock(&ctl->tree_lock);
2558 __btrfs_remove_free_space_cache_locked(ctl);
2559 spin_unlock(&ctl->tree_lock);
2560 }
2561
2562 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2563 {
2564 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2565 struct btrfs_free_cluster *cluster;
2566 struct list_head *head;
2567
2568 spin_lock(&ctl->tree_lock);
2569 while ((head = block_group->cluster_list.next) !=
2570 &block_group->cluster_list) {
2571 cluster = list_entry(head, struct btrfs_free_cluster,
2572 block_group_list);
2573
2574 WARN_ON(cluster->block_group != block_group);
2575 __btrfs_return_cluster_to_free_space(block_group, cluster);
2576
2577 cond_resched_lock(&ctl->tree_lock);
2578 }
2579 __btrfs_remove_free_space_cache_locked(ctl);
2580 spin_unlock(&ctl->tree_lock);
2581
2582 }
2583
2584 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2585 u64 offset, u64 bytes, u64 empty_size,
2586 u64 *max_extent_size)
2587 {
2588 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2589 struct btrfs_free_space *entry = NULL;
2590 u64 bytes_search = bytes + empty_size;
2591 u64 ret = 0;
2592 u64 align_gap = 0;
2593 u64 align_gap_len = 0;
2594
2595 spin_lock(&ctl->tree_lock);
2596 entry = find_free_space(ctl, &offset, &bytes_search,
2597 block_group->full_stripe_len, max_extent_size);
2598 if (!entry)
2599 goto out;
2600
2601 ret = offset;
2602 if (entry->bitmap) {
2603 bitmap_clear_bits(ctl, entry, offset, bytes);
2604 if (!entry->bytes)
2605 free_bitmap(ctl, entry);
2606 } else {
2607 unlink_free_space(ctl, entry);
2608 align_gap_len = offset - entry->offset;
2609 align_gap = entry->offset;
2610
2611 entry->offset = offset + bytes;
2612 WARN_ON(entry->bytes < bytes + align_gap_len);
2613
2614 entry->bytes -= bytes + align_gap_len;
2615 if (!entry->bytes)
2616 kmem_cache_free(btrfs_free_space_cachep, entry);
2617 else
2618 link_free_space(ctl, entry);
2619 }
2620 out:
2621 spin_unlock(&ctl->tree_lock);
2622
2623 if (align_gap_len)
2624 __btrfs_add_free_space(ctl, align_gap, align_gap_len);
2625 return ret;
2626 }
2627
2628 /*
2629 * given a cluster, put all of its extents back into the free space
2630 * cache. If a block group is passed, this function will only free
2631 * a cluster that belongs to the passed block group.
2632 *
2633 * Otherwise, it'll get a reference on the block group pointed to by the
2634 * cluster and remove the cluster from it.
2635 */
2636 int btrfs_return_cluster_to_free_space(
2637 struct btrfs_block_group_cache *block_group,
2638 struct btrfs_free_cluster *cluster)
2639 {
2640 struct btrfs_free_space_ctl *ctl;
2641 int ret;
2642
2643 /* first, get a safe pointer to the block group */
2644 spin_lock(&cluster->lock);
2645 if (!block_group) {
2646 block_group = cluster->block_group;
2647 if (!block_group) {
2648 spin_unlock(&cluster->lock);
2649 return 0;
2650 }
2651 } else if (cluster->block_group != block_group) {
2652 /* someone else has already freed it don't redo their work */
2653 spin_unlock(&cluster->lock);
2654 return 0;
2655 }
2656 atomic_inc(&block_group->count);
2657 spin_unlock(&cluster->lock);
2658
2659 ctl = block_group->free_space_ctl;
2660
2661 /* now return any extents the cluster had on it */
2662 spin_lock(&ctl->tree_lock);
2663 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2664 spin_unlock(&ctl->tree_lock);
2665
2666 /* finally drop our ref */
2667 btrfs_put_block_group(block_group);
2668 return ret;
2669 }
2670
2671 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2672 struct btrfs_free_cluster *cluster,
2673 struct btrfs_free_space *entry,
2674 u64 bytes, u64 min_start,
2675 u64 *max_extent_size)
2676 {
2677 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2678 int err;
2679 u64 search_start = cluster->window_start;
2680 u64 search_bytes = bytes;
2681 u64 ret = 0;
2682
2683 search_start = min_start;
2684 search_bytes = bytes;
2685
2686 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2687 if (err) {
2688 if (search_bytes > *max_extent_size)
2689 *max_extent_size = search_bytes;
2690 return 0;
2691 }
2692
2693 ret = search_start;
2694 __bitmap_clear_bits(ctl, entry, ret, bytes);
2695
2696 return ret;
2697 }
2698
2699 /*
2700 * given a cluster, try to allocate 'bytes' from it, returns 0
2701 * if it couldn't find anything suitably large, or a logical disk offset
2702 * if things worked out
2703 */
2704 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2705 struct btrfs_free_cluster *cluster, u64 bytes,
2706 u64 min_start, u64 *max_extent_size)
2707 {
2708 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2709 struct btrfs_free_space *entry = NULL;
2710 struct rb_node *node;
2711 u64 ret = 0;
2712
2713 spin_lock(&cluster->lock);
2714 if (bytes > cluster->max_size)
2715 goto out;
2716
2717 if (cluster->block_group != block_group)
2718 goto out;
2719
2720 node = rb_first(&cluster->root);
2721 if (!node)
2722 goto out;
2723
2724 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2725 while (1) {
2726 if (entry->bytes < bytes && entry->bytes > *max_extent_size)
2727 *max_extent_size = entry->bytes;
2728
2729 if (entry->bytes < bytes ||
2730 (!entry->bitmap && entry->offset < min_start)) {
2731 node = rb_next(&entry->offset_index);
2732 if (!node)
2733 break;
2734 entry = rb_entry(node, struct btrfs_free_space,
2735 offset_index);
2736 continue;
2737 }
2738
2739 if (entry->bitmap) {
2740 ret = btrfs_alloc_from_bitmap(block_group,
2741 cluster, entry, bytes,
2742 cluster->window_start,
2743 max_extent_size);
2744 if (ret == 0) {
2745 node = rb_next(&entry->offset_index);
2746 if (!node)
2747 break;
2748 entry = rb_entry(node, struct btrfs_free_space,
2749 offset_index);
2750 continue;
2751 }
2752 cluster->window_start += bytes;
2753 } else {
2754 ret = entry->offset;
2755
2756 entry->offset += bytes;
2757 entry->bytes -= bytes;
2758 }
2759
2760 if (entry->bytes == 0)
2761 rb_erase(&entry->offset_index, &cluster->root);
2762 break;
2763 }
2764 out:
2765 spin_unlock(&cluster->lock);
2766
2767 if (!ret)
2768 return 0;
2769
2770 spin_lock(&ctl->tree_lock);
2771
2772 ctl->free_space -= bytes;
2773 if (entry->bytes == 0) {
2774 ctl->free_extents--;
2775 if (entry->bitmap) {
2776 kfree(entry->bitmap);
2777 ctl->total_bitmaps--;
2778 ctl->op->recalc_thresholds(ctl);
2779 }
2780 kmem_cache_free(btrfs_free_space_cachep, entry);
2781 }
2782
2783 spin_unlock(&ctl->tree_lock);
2784
2785 return ret;
2786 }
2787
2788 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2789 struct btrfs_free_space *entry,
2790 struct btrfs_free_cluster *cluster,
2791 u64 offset, u64 bytes,
2792 u64 cont1_bytes, u64 min_bytes)
2793 {
2794 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2795 unsigned long next_zero;
2796 unsigned long i;
2797 unsigned long want_bits;
2798 unsigned long min_bits;
2799 unsigned long found_bits;
2800 unsigned long max_bits = 0;
2801 unsigned long start = 0;
2802 unsigned long total_found = 0;
2803 int ret;
2804
2805 i = offset_to_bit(entry->offset, ctl->unit,
2806 max_t(u64, offset, entry->offset));
2807 want_bits = bytes_to_bits(bytes, ctl->unit);
2808 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2809
2810 /*
2811 * Don't bother looking for a cluster in this bitmap if it's heavily
2812 * fragmented.
2813 */
2814 if (entry->max_extent_size &&
2815 entry->max_extent_size < cont1_bytes)
2816 return -ENOSPC;
2817 again:
2818 found_bits = 0;
2819 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2820 next_zero = find_next_zero_bit(entry->bitmap,
2821 BITS_PER_BITMAP, i);
2822 if (next_zero - i >= min_bits) {
2823 found_bits = next_zero - i;
2824 if (found_bits > max_bits)
2825 max_bits = found_bits;
2826 break;
2827 }
2828 if (next_zero - i > max_bits)
2829 max_bits = next_zero - i;
2830 i = next_zero;
2831 }
2832
2833 if (!found_bits) {
2834 entry->max_extent_size = (u64)max_bits * ctl->unit;
2835 return -ENOSPC;
2836 }
2837
2838 if (!total_found) {
2839 start = i;
2840 cluster->max_size = 0;
2841 }
2842
2843 total_found += found_bits;
2844
2845 if (cluster->max_size < found_bits * ctl->unit)
2846 cluster->max_size = found_bits * ctl->unit;
2847
2848 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2849 i = next_zero + 1;
2850 goto again;
2851 }
2852
2853 cluster->window_start = start * ctl->unit + entry->offset;
2854 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2855 ret = tree_insert_offset(&cluster->root, entry->offset,
2856 &entry->offset_index, 1);
2857 ASSERT(!ret); /* -EEXIST; Logic error */
2858
2859 trace_btrfs_setup_cluster(block_group, cluster,
2860 total_found * ctl->unit, 1);
2861 return 0;
2862 }
2863
2864 /*
2865 * This searches the block group for just extents to fill the cluster with.
2866 * Try to find a cluster with at least bytes total bytes, at least one
2867 * extent of cont1_bytes, and other clusters of at least min_bytes.
2868 */
2869 static noinline int
2870 setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2871 struct btrfs_free_cluster *cluster,
2872 struct list_head *bitmaps, u64 offset, u64 bytes,
2873 u64 cont1_bytes, u64 min_bytes)
2874 {
2875 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2876 struct btrfs_free_space *first = NULL;
2877 struct btrfs_free_space *entry = NULL;
2878 struct btrfs_free_space *last;
2879 struct rb_node *node;
2880 u64 window_free;
2881 u64 max_extent;
2882 u64 total_size = 0;
2883
2884 entry = tree_search_offset(ctl, offset, 0, 1);
2885 if (!entry)
2886 return -ENOSPC;
2887
2888 /*
2889 * We don't want bitmaps, so just move along until we find a normal
2890 * extent entry.
2891 */
2892 while (entry->bitmap || entry->bytes < min_bytes) {
2893 if (entry->bitmap && list_empty(&entry->list))
2894 list_add_tail(&entry->list, bitmaps);
2895 node = rb_next(&entry->offset_index);
2896 if (!node)
2897 return -ENOSPC;
2898 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2899 }
2900
2901 window_free = entry->bytes;
2902 max_extent = entry->bytes;
2903 first = entry;
2904 last = entry;
2905
2906 for (node = rb_next(&entry->offset_index); node;
2907 node = rb_next(&entry->offset_index)) {
2908 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2909
2910 if (entry->bitmap) {
2911 if (list_empty(&entry->list))
2912 list_add_tail(&entry->list, bitmaps);
2913 continue;
2914 }
2915
2916 if (entry->bytes < min_bytes)
2917 continue;
2918
2919 last = entry;
2920 window_free += entry->bytes;
2921 if (entry->bytes > max_extent)
2922 max_extent = entry->bytes;
2923 }
2924
2925 if (window_free < bytes || max_extent < cont1_bytes)
2926 return -ENOSPC;
2927
2928 cluster->window_start = first->offset;
2929
2930 node = &first->offset_index;
2931
2932 /*
2933 * now we've found our entries, pull them out of the free space
2934 * cache and put them into the cluster rbtree
2935 */
2936 do {
2937 int ret;
2938
2939 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2940 node = rb_next(&entry->offset_index);
2941 if (entry->bitmap || entry->bytes < min_bytes)
2942 continue;
2943
2944 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2945 ret = tree_insert_offset(&cluster->root, entry->offset,
2946 &entry->offset_index, 0);
2947 total_size += entry->bytes;
2948 ASSERT(!ret); /* -EEXIST; Logic error */
2949 } while (node && entry != last);
2950
2951 cluster->max_size = max_extent;
2952 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2953 return 0;
2954 }
2955
2956 /*
2957 * This specifically looks for bitmaps that may work in the cluster, we assume
2958 * that we have already failed to find extents that will work.
2959 */
2960 static noinline int
2961 setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
2962 struct btrfs_free_cluster *cluster,
2963 struct list_head *bitmaps, u64 offset, u64 bytes,
2964 u64 cont1_bytes, u64 min_bytes)
2965 {
2966 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2967 struct btrfs_free_space *entry = NULL;
2968 int ret = -ENOSPC;
2969 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
2970
2971 if (ctl->total_bitmaps == 0)
2972 return -ENOSPC;
2973
2974 /*
2975 * The bitmap that covers offset won't be in the list unless offset
2976 * is just its start offset.
2977 */
2978 if (!list_empty(bitmaps))
2979 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
2980
2981 if (!entry || entry->offset != bitmap_offset) {
2982 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
2983 if (entry && list_empty(&entry->list))
2984 list_add(&entry->list, bitmaps);
2985 }
2986
2987 list_for_each_entry(entry, bitmaps, list) {
2988 if (entry->bytes < bytes)
2989 continue;
2990 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
2991 bytes, cont1_bytes, min_bytes);
2992 if (!ret)
2993 return 0;
2994 }
2995
2996 /*
2997 * The bitmaps list has all the bitmaps that record free space
2998 * starting after offset, so no more search is required.
2999 */
3000 return -ENOSPC;
3001 }
3002
3003 /*
3004 * here we try to find a cluster of blocks in a block group. The goal
3005 * is to find at least bytes+empty_size.
3006 * We might not find them all in one contiguous area.
3007 *
3008 * returns zero and sets up cluster if things worked out, otherwise
3009 * it returns -enospc
3010 */
3011 int btrfs_find_space_cluster(struct btrfs_root *root,
3012 struct btrfs_block_group_cache *block_group,
3013 struct btrfs_free_cluster *cluster,
3014 u64 offset, u64 bytes, u64 empty_size)
3015 {
3016 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3017 struct btrfs_free_space *entry, *tmp;
3018 LIST_HEAD(bitmaps);
3019 u64 min_bytes;
3020 u64 cont1_bytes;
3021 int ret;
3022
3023 /*
3024 * Choose the minimum extent size we'll require for this
3025 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3026 * For metadata, allow allocates with smaller extents. For
3027 * data, keep it dense.
3028 */
3029 if (btrfs_test_opt(root, SSD_SPREAD)) {
3030 cont1_bytes = min_bytes = bytes + empty_size;
3031 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3032 cont1_bytes = bytes;
3033 min_bytes = block_group->sectorsize;
3034 } else {
3035 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3036 min_bytes = block_group->sectorsize;
3037 }
3038
3039 spin_lock(&ctl->tree_lock);
3040
3041 /*
3042 * If we know we don't have enough space to make a cluster don't even
3043 * bother doing all the work to try and find one.
3044 */
3045 if (ctl->free_space < bytes) {
3046 spin_unlock(&ctl->tree_lock);
3047 return -ENOSPC;
3048 }
3049
3050 spin_lock(&cluster->lock);
3051
3052 /* someone already found a cluster, hooray */
3053 if (cluster->block_group) {
3054 ret = 0;
3055 goto out;
3056 }
3057
3058 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3059 min_bytes);
3060
3061 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3062 bytes + empty_size,
3063 cont1_bytes, min_bytes);
3064 if (ret)
3065 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3066 offset, bytes + empty_size,
3067 cont1_bytes, min_bytes);
3068
3069 /* Clear our temporary list */
3070 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3071 list_del_init(&entry->list);
3072
3073 if (!ret) {
3074 atomic_inc(&block_group->count);
3075 list_add_tail(&cluster->block_group_list,
3076 &block_group->cluster_list);
3077 cluster->block_group = block_group;
3078 } else {
3079 trace_btrfs_failed_cluster_setup(block_group);
3080 }
3081 out:
3082 spin_unlock(&cluster->lock);
3083 spin_unlock(&ctl->tree_lock);
3084
3085 return ret;
3086 }
3087
3088 /*
3089 * simple code to zero out a cluster
3090 */
3091 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3092 {
3093 spin_lock_init(&cluster->lock);
3094 spin_lock_init(&cluster->refill_lock);
3095 cluster->root = RB_ROOT;
3096 cluster->max_size = 0;
3097 cluster->fragmented = false;
3098 INIT_LIST_HEAD(&cluster->block_group_list);
3099 cluster->block_group = NULL;
3100 }
3101
3102 static int do_trimming(struct btrfs_block_group_cache *block_group,
3103 u64 *total_trimmed, u64 start, u64 bytes,
3104 u64 reserved_start, u64 reserved_bytes,
3105 struct btrfs_trim_range *trim_entry)
3106 {
3107 struct btrfs_space_info *space_info = block_group->space_info;
3108 struct btrfs_fs_info *fs_info = block_group->fs_info;
3109 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3110 int ret;
3111 int update = 0;
3112 u64 trimmed = 0;
3113
3114 spin_lock(&space_info->lock);
3115 spin_lock(&block_group->lock);
3116 if (!block_group->ro) {
3117 block_group->reserved += reserved_bytes;
3118 space_info->bytes_reserved += reserved_bytes;
3119 update = 1;
3120 }
3121 spin_unlock(&block_group->lock);
3122 spin_unlock(&space_info->lock);
3123
3124 ret = btrfs_discard_extent(fs_info->extent_root,
3125 start, bytes, &trimmed);
3126 if (!ret)
3127 *total_trimmed += trimmed;
3128
3129 mutex_lock(&ctl->cache_writeout_mutex);
3130 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
3131 list_del(&trim_entry->list);
3132 mutex_unlock(&ctl->cache_writeout_mutex);
3133
3134 if (update) {
3135 spin_lock(&space_info->lock);
3136 spin_lock(&block_group->lock);
3137 if (block_group->ro)
3138 space_info->bytes_readonly += reserved_bytes;
3139 block_group->reserved -= reserved_bytes;
3140 space_info->bytes_reserved -= reserved_bytes;
3141 spin_unlock(&space_info->lock);
3142 spin_unlock(&block_group->lock);
3143 }
3144
3145 return ret;
3146 }
3147
3148 static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
3149 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3150 {
3151 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3152 struct btrfs_free_space *entry;
3153 struct rb_node *node;
3154 int ret = 0;
3155 u64 extent_start;
3156 u64 extent_bytes;
3157 u64 bytes;
3158
3159 while (start < end) {
3160 struct btrfs_trim_range trim_entry;
3161
3162 mutex_lock(&ctl->cache_writeout_mutex);
3163 spin_lock(&ctl->tree_lock);
3164
3165 if (ctl->free_space < minlen) {
3166 spin_unlock(&ctl->tree_lock);
3167 mutex_unlock(&ctl->cache_writeout_mutex);
3168 break;
3169 }
3170
3171 entry = tree_search_offset(ctl, start, 0, 1);
3172 if (!entry) {
3173 spin_unlock(&ctl->tree_lock);
3174 mutex_unlock(&ctl->cache_writeout_mutex);
3175 break;
3176 }
3177
3178 /* skip bitmaps */
3179 while (entry->bitmap) {
3180 node = rb_next(&entry->offset_index);
3181 if (!node) {
3182 spin_unlock(&ctl->tree_lock);
3183 mutex_unlock(&ctl->cache_writeout_mutex);
3184 goto out;
3185 }
3186 entry = rb_entry(node, struct btrfs_free_space,
3187 offset_index);
3188 }
3189
3190 if (entry->offset >= end) {
3191 spin_unlock(&ctl->tree_lock);
3192 mutex_unlock(&ctl->cache_writeout_mutex);
3193 break;
3194 }
3195
3196 extent_start = entry->offset;
3197 extent_bytes = entry->bytes;
3198 start = max(start, extent_start);
3199 bytes = min(extent_start + extent_bytes, end) - start;
3200 if (bytes < minlen) {
3201 spin_unlock(&ctl->tree_lock);
3202 mutex_unlock(&ctl->cache_writeout_mutex);
3203 goto next;
3204 }
3205
3206 unlink_free_space(ctl, entry);
3207 kmem_cache_free(btrfs_free_space_cachep, entry);
3208
3209 spin_unlock(&ctl->tree_lock);
3210 trim_entry.start = extent_start;
3211 trim_entry.bytes = extent_bytes;
3212 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3213 mutex_unlock(&ctl->cache_writeout_mutex);
3214
3215 ret = do_trimming(block_group, total_trimmed, start, bytes,
3216 extent_start, extent_bytes, &trim_entry);
3217 if (ret)
3218 break;
3219 next:
3220 start += bytes;
3221
3222 if (fatal_signal_pending(current)) {
3223 ret = -ERESTARTSYS;
3224 break;
3225 }
3226
3227 cond_resched();
3228 }
3229 out:
3230 return ret;
3231 }
3232
3233 static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
3234 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3235 {
3236 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3237 struct btrfs_free_space *entry;
3238 int ret = 0;
3239 int ret2;
3240 u64 bytes;
3241 u64 offset = offset_to_bitmap(ctl, start);
3242
3243 while (offset < end) {
3244 bool next_bitmap = false;
3245 struct btrfs_trim_range trim_entry;
3246
3247 mutex_lock(&ctl->cache_writeout_mutex);
3248 spin_lock(&ctl->tree_lock);
3249
3250 if (ctl->free_space < minlen) {
3251 spin_unlock(&ctl->tree_lock);
3252 mutex_unlock(&ctl->cache_writeout_mutex);
3253 break;
3254 }
3255
3256 entry = tree_search_offset(ctl, offset, 1, 0);
3257 if (!entry) {
3258 spin_unlock(&ctl->tree_lock);
3259 mutex_unlock(&ctl->cache_writeout_mutex);
3260 next_bitmap = true;
3261 goto next;
3262 }
3263
3264 bytes = minlen;
3265 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3266 if (ret2 || start >= end) {
3267 spin_unlock(&ctl->tree_lock);
3268 mutex_unlock(&ctl->cache_writeout_mutex);
3269 next_bitmap = true;
3270 goto next;
3271 }
3272
3273 bytes = min(bytes, end - start);
3274 if (bytes < minlen) {
3275 spin_unlock(&ctl->tree_lock);
3276 mutex_unlock(&ctl->cache_writeout_mutex);
3277 goto next;
3278 }
3279
3280 bitmap_clear_bits(ctl, entry, start, bytes);
3281 if (entry->bytes == 0)
3282 free_bitmap(ctl, entry);
3283
3284 spin_unlock(&ctl->tree_lock);
3285 trim_entry.start = start;
3286 trim_entry.bytes = bytes;
3287 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3288 mutex_unlock(&ctl->cache_writeout_mutex);
3289
3290 ret = do_trimming(block_group, total_trimmed, start, bytes,
3291 start, bytes, &trim_entry);
3292 if (ret)
3293 break;
3294 next:
3295 if (next_bitmap) {
3296 offset += BITS_PER_BITMAP * ctl->unit;
3297 } else {
3298 start += bytes;
3299 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
3300 offset += BITS_PER_BITMAP * ctl->unit;
3301 }
3302
3303 if (fatal_signal_pending(current)) {
3304 ret = -ERESTARTSYS;
3305 break;
3306 }
3307
3308 cond_resched();
3309 }
3310
3311 return ret;
3312 }
3313
3314 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
3315 {
3316 atomic_inc(&cache->trimming);
3317 }
3318
3319 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
3320 {
3321 struct extent_map_tree *em_tree;
3322 struct extent_map *em;
3323 bool cleanup;
3324
3325 spin_lock(&block_group->lock);
3326 cleanup = (atomic_dec_and_test(&block_group->trimming) &&
3327 block_group->removed);
3328 spin_unlock(&block_group->lock);
3329
3330 if (cleanup) {
3331 lock_chunks(block_group->fs_info->chunk_root);
3332 em_tree = &block_group->fs_info->mapping_tree.map_tree;
3333 write_lock(&em_tree->lock);
3334 em = lookup_extent_mapping(em_tree, block_group->key.objectid,
3335 1);
3336 BUG_ON(!em); /* logic error, can't happen */
3337 /*
3338 * remove_extent_mapping() will delete us from the pinned_chunks
3339 * list, which is protected by the chunk mutex.
3340 */
3341 remove_extent_mapping(em_tree, em);
3342 write_unlock(&em_tree->lock);
3343 unlock_chunks(block_group->fs_info->chunk_root);
3344
3345 /* once for us and once for the tree */
3346 free_extent_map(em);
3347 free_extent_map(em);
3348
3349 /*
3350 * We've left one free space entry and other tasks trimming
3351 * this block group have left 1 entry each one. Free them.
3352 */
3353 __btrfs_remove_free_space_cache(block_group->free_space_ctl);
3354 }
3355 }
3356
3357 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
3358 u64 *trimmed, u64 start, u64 end, u64 minlen)
3359 {
3360 int ret;
3361
3362 *trimmed = 0;
3363
3364 spin_lock(&block_group->lock);
3365 if (block_group->removed) {
3366 spin_unlock(&block_group->lock);
3367 return 0;
3368 }
3369 btrfs_get_block_group_trimming(block_group);
3370 spin_unlock(&block_group->lock);
3371
3372 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
3373 if (ret)
3374 goto out;
3375
3376 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
3377 out:
3378 btrfs_put_block_group_trimming(block_group);
3379 return ret;
3380 }
3381
3382 /*
3383 * Find the left-most item in the cache tree, and then return the
3384 * smallest inode number in the item.
3385 *
3386 * Note: the returned inode number may not be the smallest one in
3387 * the tree, if the left-most item is a bitmap.
3388 */
3389 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3390 {
3391 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3392 struct btrfs_free_space *entry = NULL;
3393 u64 ino = 0;
3394
3395 spin_lock(&ctl->tree_lock);
3396
3397 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3398 goto out;
3399
3400 entry = rb_entry(rb_first(&ctl->free_space_offset),
3401 struct btrfs_free_space, offset_index);
3402
3403 if (!entry->bitmap) {
3404 ino = entry->offset;
3405
3406 unlink_free_space(ctl, entry);
3407 entry->offset++;
3408 entry->bytes--;
3409 if (!entry->bytes)
3410 kmem_cache_free(btrfs_free_space_cachep, entry);
3411 else
3412 link_free_space(ctl, entry);
3413 } else {
3414 u64 offset = 0;
3415 u64 count = 1;
3416 int ret;
3417
3418 ret = search_bitmap(ctl, entry, &offset, &count, true);
3419 /* Logic error; Should be empty if it can't find anything */
3420 ASSERT(!ret);
3421
3422 ino = offset;
3423 bitmap_clear_bits(ctl, entry, offset, 1);
3424 if (entry->bytes == 0)
3425 free_bitmap(ctl, entry);
3426 }
3427 out:
3428 spin_unlock(&ctl->tree_lock);
3429
3430 return ino;
3431 }
3432
3433 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3434 struct btrfs_path *path)
3435 {
3436 struct inode *inode = NULL;
3437
3438 spin_lock(&root->ino_cache_lock);
3439 if (root->ino_cache_inode)
3440 inode = igrab(root->ino_cache_inode);
3441 spin_unlock(&root->ino_cache_lock);
3442 if (inode)
3443 return inode;
3444
3445 inode = __lookup_free_space_inode(root, path, 0);
3446 if (IS_ERR(inode))
3447 return inode;
3448
3449 spin_lock(&root->ino_cache_lock);
3450 if (!btrfs_fs_closing(root->fs_info))
3451 root->ino_cache_inode = igrab(inode);
3452 spin_unlock(&root->ino_cache_lock);
3453
3454 return inode;
3455 }
3456
3457 int create_free_ino_inode(struct btrfs_root *root,
3458 struct btrfs_trans_handle *trans,
3459 struct btrfs_path *path)
3460 {
3461 return __create_free_space_inode(root, trans, path,
3462 BTRFS_FREE_INO_OBJECTID, 0);
3463 }
3464
3465 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3466 {
3467 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3468 struct btrfs_path *path;
3469 struct inode *inode;
3470 int ret = 0;
3471 u64 root_gen = btrfs_root_generation(&root->root_item);
3472
3473 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3474 return 0;
3475
3476 /*
3477 * If we're unmounting then just return, since this does a search on the
3478 * normal root and not the commit root and we could deadlock.
3479 */
3480 if (btrfs_fs_closing(fs_info))
3481 return 0;
3482
3483 path = btrfs_alloc_path();
3484 if (!path)
3485 return 0;
3486
3487 inode = lookup_free_ino_inode(root, path);
3488 if (IS_ERR(inode))
3489 goto out;
3490
3491 if (root_gen != BTRFS_I(inode)->generation)
3492 goto out_put;
3493
3494 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3495
3496 if (ret < 0)
3497 btrfs_err(fs_info,
3498 "failed to load free ino cache for root %llu",
3499 root->root_key.objectid);
3500 out_put:
3501 iput(inode);
3502 out:
3503 btrfs_free_path(path);
3504 return ret;
3505 }
3506
3507 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3508 struct btrfs_trans_handle *trans,
3509 struct btrfs_path *path,
3510 struct inode *inode)
3511 {
3512 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3513 int ret;
3514 struct btrfs_io_ctl io_ctl;
3515 bool release_metadata = true;
3516
3517 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3518 return 0;
3519
3520 memset(&io_ctl, 0, sizeof(io_ctl));
3521 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl,
3522 trans, path, 0);
3523 if (!ret) {
3524 /*
3525 * At this point writepages() didn't error out, so our metadata
3526 * reservation is released when the writeback finishes, at
3527 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3528 * with or without an error.
3529 */
3530 release_metadata = false;
3531 ret = btrfs_wait_cache_io(root, trans, NULL, &io_ctl, path, 0);
3532 }
3533
3534 if (ret) {
3535 if (release_metadata)
3536 btrfs_delalloc_release_metadata(inode, inode->i_size);
3537 #ifdef DEBUG
3538 btrfs_err(root->fs_info,
3539 "failed to write free ino cache for root %llu",
3540 root->root_key.objectid);
3541 #endif
3542 }
3543
3544 return ret;
3545 }
3546
3547 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3548 /*
3549 * Use this if you need to make a bitmap or extent entry specifically, it
3550 * doesn't do any of the merging that add_free_space does, this acts a lot like
3551 * how the free space cache loading stuff works, so you can get really weird
3552 * configurations.
3553 */
3554 int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3555 u64 offset, u64 bytes, bool bitmap)
3556 {
3557 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3558 struct btrfs_free_space *info = NULL, *bitmap_info;
3559 void *map = NULL;
3560 u64 bytes_added;
3561 int ret;
3562
3563 again:
3564 if (!info) {
3565 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3566 if (!info)
3567 return -ENOMEM;
3568 }
3569
3570 if (!bitmap) {
3571 spin_lock(&ctl->tree_lock);
3572 info->offset = offset;
3573 info->bytes = bytes;
3574 info->max_extent_size = 0;
3575 ret = link_free_space(ctl, info);
3576 spin_unlock(&ctl->tree_lock);
3577 if (ret)
3578 kmem_cache_free(btrfs_free_space_cachep, info);
3579 return ret;
3580 }
3581
3582 if (!map) {
3583 map = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
3584 if (!map) {
3585 kmem_cache_free(btrfs_free_space_cachep, info);
3586 return -ENOMEM;
3587 }
3588 }
3589
3590 spin_lock(&ctl->tree_lock);
3591 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3592 1, 0);
3593 if (!bitmap_info) {
3594 info->bitmap = map;
3595 map = NULL;
3596 add_new_bitmap(ctl, info, offset);
3597 bitmap_info = info;
3598 info = NULL;
3599 }
3600
3601 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3602
3603 bytes -= bytes_added;
3604 offset += bytes_added;
3605 spin_unlock(&ctl->tree_lock);
3606
3607 if (bytes)
3608 goto again;
3609
3610 if (info)
3611 kmem_cache_free(btrfs_free_space_cachep, info);
3612 if (map)
3613 kfree(map);
3614 return 0;
3615 }
3616
3617 /*
3618 * Checks to see if the given range is in the free space cache. This is really
3619 * just used to check the absence of space, so if there is free space in the
3620 * range at all we will return 1.
3621 */
3622 int test_check_exists(struct btrfs_block_group_cache *cache,
3623 u64 offset, u64 bytes)
3624 {
3625 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3626 struct btrfs_free_space *info;
3627 int ret = 0;
3628
3629 spin_lock(&ctl->tree_lock);
3630 info = tree_search_offset(ctl, offset, 0, 0);
3631 if (!info) {
3632 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3633 1, 0);
3634 if (!info)
3635 goto out;
3636 }
3637
3638 have_info:
3639 if (info->bitmap) {
3640 u64 bit_off, bit_bytes;
3641 struct rb_node *n;
3642 struct btrfs_free_space *tmp;
3643
3644 bit_off = offset;
3645 bit_bytes = ctl->unit;
3646 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
3647 if (!ret) {
3648 if (bit_off == offset) {
3649 ret = 1;
3650 goto out;
3651 } else if (bit_off > offset &&
3652 offset + bytes > bit_off) {
3653 ret = 1;
3654 goto out;
3655 }
3656 }
3657
3658 n = rb_prev(&info->offset_index);
3659 while (n) {
3660 tmp = rb_entry(n, struct btrfs_free_space,
3661 offset_index);
3662 if (tmp->offset + tmp->bytes < offset)
3663 break;
3664 if (offset + bytes < tmp->offset) {
3665 n = rb_prev(&info->offset_index);
3666 continue;
3667 }
3668 info = tmp;
3669 goto have_info;
3670 }
3671
3672 n = rb_next(&info->offset_index);
3673 while (n) {
3674 tmp = rb_entry(n, struct btrfs_free_space,
3675 offset_index);
3676 if (offset + bytes < tmp->offset)
3677 break;
3678 if (tmp->offset + tmp->bytes < offset) {
3679 n = rb_next(&info->offset_index);
3680 continue;
3681 }
3682 info = tmp;
3683 goto have_info;
3684 }
3685
3686 ret = 0;
3687 goto out;
3688 }
3689
3690 if (info->offset == offset) {
3691 ret = 1;
3692 goto out;
3693 }
3694
3695 if (offset > info->offset && offset < info->offset + info->bytes)
3696 ret = 1;
3697 out:
3698 spin_unlock(&ctl->tree_lock);
3699 return ret;
3700 }
3701 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Linux kernel - Deliverables
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