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Linux 5.8-rc4
[linux/fpc-iii.git] / fs / btrfs / free-space-cache.c
blob55955bd424d7083c9d142092b5f18605220baa26
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2008 Red Hat. All rights reserved.
4 */
5
6 #include <linux/pagemap.h>
7 #include <linux/sched.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
10 #include <linux/math64.h>
11 #include <linux/ratelimit.h>
12 #include <linux/error-injection.h>
13 #include <linux/sched/mm.h>
14 #include "ctree.h"
15 #include "free-space-cache.h"
16 #include "transaction.h"
17 #include "disk-io.h"
18 #include "extent_io.h"
19 #include "inode-map.h"
20 #include "volumes.h"
21 #include "space-info.h"
22 #include "delalloc-space.h"
23 #include "block-group.h"
24 #include "discard.h"
25
26 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
27 #define MAX_CACHE_BYTES_PER_GIG SZ_64K
28 #define FORCE_EXTENT_THRESHOLD SZ_1M
29
30 struct btrfs_trim_range {
31 u64 start;
32 u64 bytes;
33 struct list_head list;
34 };
35
36 static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl,
37 struct btrfs_free_space *bitmap_info);
38 static int link_free_space(struct btrfs_free_space_ctl *ctl,
39 struct btrfs_free_space *info);
40 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
41 struct btrfs_free_space *info);
42 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
43 struct btrfs_trans_handle *trans,
44 struct btrfs_io_ctl *io_ctl,
45 struct btrfs_path *path);
46
47 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
48 struct btrfs_path *path,
49 u64 offset)
50 {
51 struct btrfs_fs_info *fs_info = root->fs_info;
52 struct btrfs_key key;
53 struct btrfs_key location;
54 struct btrfs_disk_key disk_key;
55 struct btrfs_free_space_header *header;
56 struct extent_buffer *leaf;
57 struct inode *inode = NULL;
58 unsigned nofs_flag;
59 int ret;
60
61 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
62 key.offset = offset;
63 key.type = 0;
64
65 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
66 if (ret < 0)
67 return ERR_PTR(ret);
68 if (ret > 0) {
69 btrfs_release_path(path);
70 return ERR_PTR(-ENOENT);
71 }
72
73 leaf = path->nodes[0];
74 header = btrfs_item_ptr(leaf, path->slots[0],
75 struct btrfs_free_space_header);
76 btrfs_free_space_key(leaf, header, &disk_key);
77 btrfs_disk_key_to_cpu(&location, &disk_key);
78 btrfs_release_path(path);
79
80 /*
81 * We are often under a trans handle at this point, so we need to make
82 * sure NOFS is set to keep us from deadlocking.
83 */
84 nofs_flag = memalloc_nofs_save();
85 inode = btrfs_iget_path(fs_info->sb, location.objectid, root, path);
86 btrfs_release_path(path);
87 memalloc_nofs_restore(nofs_flag);
88 if (IS_ERR(inode))
89 return inode;
90
91 mapping_set_gfp_mask(inode->i_mapping,
92 mapping_gfp_constraint(inode->i_mapping,
93 ~(__GFP_FS | __GFP_HIGHMEM)));
94
95 return inode;
96 }
97
98 struct inode *lookup_free_space_inode(struct btrfs_block_group *block_group,
99 struct btrfs_path *path)
100 {
101 struct btrfs_fs_info *fs_info = block_group->fs_info;
102 struct inode *inode = NULL;
103 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
104
105 spin_lock(&block_group->lock);
106 if (block_group->inode)
107 inode = igrab(block_group->inode);
108 spin_unlock(&block_group->lock);
109 if (inode)
110 return inode;
111
112 inode = __lookup_free_space_inode(fs_info->tree_root, path,
113 block_group->start);
114 if (IS_ERR(inode))
115 return inode;
116
117 spin_lock(&block_group->lock);
118 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
119 btrfs_info(fs_info, "Old style space inode found, converting.");
120 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
121 BTRFS_INODE_NODATACOW;
122 block_group->disk_cache_state = BTRFS_DC_CLEAR;
123 }
124
125 if (!block_group->iref) {
126 block_group->inode = igrab(inode);
127 block_group->iref = 1;
128 }
129 spin_unlock(&block_group->lock);
130
131 return inode;
132 }
133
134 static int __create_free_space_inode(struct btrfs_root *root,
135 struct btrfs_trans_handle *trans,
136 struct btrfs_path *path,
137 u64 ino, u64 offset)
138 {
139 struct btrfs_key key;
140 struct btrfs_disk_key disk_key;
141 struct btrfs_free_space_header *header;
142 struct btrfs_inode_item *inode_item;
143 struct extent_buffer *leaf;
144 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
145 int ret;
146
147 ret = btrfs_insert_empty_inode(trans, root, path, ino);
148 if (ret)
149 return ret;
150
151 /* We inline crc's for the free disk space cache */
152 if (ino != BTRFS_FREE_INO_OBJECTID)
153 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
154
155 leaf = path->nodes[0];
156 inode_item = btrfs_item_ptr(leaf, path->slots[0],
157 struct btrfs_inode_item);
158 btrfs_item_key(leaf, &disk_key, path->slots[0]);
159 memzero_extent_buffer(leaf, (unsigned long)inode_item,
160 sizeof(*inode_item));
161 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
162 btrfs_set_inode_size(leaf, inode_item, 0);
163 btrfs_set_inode_nbytes(leaf, inode_item, 0);
164 btrfs_set_inode_uid(leaf, inode_item, 0);
165 btrfs_set_inode_gid(leaf, inode_item, 0);
166 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
167 btrfs_set_inode_flags(leaf, inode_item, flags);
168 btrfs_set_inode_nlink(leaf, inode_item, 1);
169 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
170 btrfs_set_inode_block_group(leaf, inode_item, offset);
171 btrfs_mark_buffer_dirty(leaf);
172 btrfs_release_path(path);
173
174 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
175 key.offset = offset;
176 key.type = 0;
177 ret = btrfs_insert_empty_item(trans, root, path, &key,
178 sizeof(struct btrfs_free_space_header));
179 if (ret < 0) {
180 btrfs_release_path(path);
181 return ret;
182 }
183
184 leaf = path->nodes[0];
185 header = btrfs_item_ptr(leaf, path->slots[0],
186 struct btrfs_free_space_header);
187 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
188 btrfs_set_free_space_key(leaf, header, &disk_key);
189 btrfs_mark_buffer_dirty(leaf);
190 btrfs_release_path(path);
191
192 return 0;
193 }
194
195 int create_free_space_inode(struct btrfs_trans_handle *trans,
196 struct btrfs_block_group *block_group,
197 struct btrfs_path *path)
198 {
199 int ret;
200 u64 ino;
201
202 ret = btrfs_find_free_objectid(trans->fs_info->tree_root, &ino);
203 if (ret < 0)
204 return ret;
205
206 return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
207 ino, block_group->start);
208 }
209
210 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
211 struct btrfs_block_rsv *rsv)
212 {
213 u64 needed_bytes;
214 int ret;
215
216 /* 1 for slack space, 1 for updating the inode */
217 needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
218 btrfs_calc_metadata_size(fs_info, 1);
219
220 spin_lock(&rsv->lock);
221 if (rsv->reserved < needed_bytes)
222 ret = -ENOSPC;
223 else
224 ret = 0;
225 spin_unlock(&rsv->lock);
226 return ret;
227 }
228
229 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
230 struct btrfs_block_group *block_group,
231 struct inode *inode)
232 {
233 struct btrfs_root *root = BTRFS_I(inode)->root;
234 int ret = 0;
235 bool locked = false;
236
237 if (block_group) {
238 struct btrfs_path *path = btrfs_alloc_path();
239
240 if (!path) {
241 ret = -ENOMEM;
242 goto fail;
243 }
244 locked = true;
245 mutex_lock(&trans->transaction->cache_write_mutex);
246 if (!list_empty(&block_group->io_list)) {
247 list_del_init(&block_group->io_list);
248
249 btrfs_wait_cache_io(trans, block_group, path);
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 btrfs_free_path(path);
261 }
262
263 btrfs_i_size_write(BTRFS_I(inode), 0);
264 truncate_pagecache(inode, 0);
265
266 /*
267 * We skip the throttling logic for free space cache inodes, so we don't
268 * need to check for -EAGAIN.
269 */
270 ret = btrfs_truncate_inode_items(trans, root, inode,
271 0, BTRFS_EXTENT_DATA_KEY);
272 if (ret)
273 goto fail;
274
275 ret = btrfs_update_inode(trans, root, inode);
276
277 fail:
278 if (locked)
279 mutex_unlock(&trans->transaction->cache_write_mutex);
280 if (ret)
281 btrfs_abort_transaction(trans, ret);
282
283 return ret;
284 }
285
286 static void readahead_cache(struct inode *inode)
287 {
288 struct file_ra_state *ra;
289 unsigned long last_index;
290
291 ra = kzalloc(sizeof(*ra), GFP_NOFS);
292 if (!ra)
293 return;
294
295 file_ra_state_init(ra, inode->i_mapping);
296 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
297
298 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
299
300 kfree(ra);
301 }
302
303 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
304 int write)
305 {
306 int num_pages;
307 int check_crcs = 0;
308
309 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
310
311 if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
312 check_crcs = 1;
313
314 /* Make sure we can fit our crcs and generation into the first page */
315 if (write && check_crcs &&
316 (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
317 return -ENOSPC;
318
319 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
320
321 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
322 if (!io_ctl->pages)
323 return -ENOMEM;
324
325 io_ctl->num_pages = num_pages;
326 io_ctl->fs_info = btrfs_sb(inode->i_sb);
327 io_ctl->check_crcs = check_crcs;
328 io_ctl->inode = inode;
329
330 return 0;
331 }
332 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
333
334 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
335 {
336 kfree(io_ctl->pages);
337 io_ctl->pages = NULL;
338 }
339
340 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
341 {
342 if (io_ctl->cur) {
343 io_ctl->cur = NULL;
344 io_ctl->orig = NULL;
345 }
346 }
347
348 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
349 {
350 ASSERT(io_ctl->index < io_ctl->num_pages);
351 io_ctl->page = io_ctl->pages[io_ctl->index++];
352 io_ctl->cur = page_address(io_ctl->page);
353 io_ctl->orig = io_ctl->cur;
354 io_ctl->size = PAGE_SIZE;
355 if (clear)
356 clear_page(io_ctl->cur);
357 }
358
359 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
360 {
361 int i;
362
363 io_ctl_unmap_page(io_ctl);
364
365 for (i = 0; i < io_ctl->num_pages; i++) {
366 if (io_ctl->pages[i]) {
367 ClearPageChecked(io_ctl->pages[i]);
368 unlock_page(io_ctl->pages[i]);
369 put_page(io_ctl->pages[i]);
370 }
371 }
372 }
373
374 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, bool uptodate)
375 {
376 struct page *page;
377 struct inode *inode = io_ctl->inode;
378 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
379 int i;
380
381 for (i = 0; i < io_ctl->num_pages; i++) {
382 page = find_or_create_page(inode->i_mapping, i, mask);
383 if (!page) {
384 io_ctl_drop_pages(io_ctl);
385 return -ENOMEM;
386 }
387 io_ctl->pages[i] = page;
388 if (uptodate && !PageUptodate(page)) {
389 btrfs_readpage(NULL, page);
390 lock_page(page);
391 if (page->mapping != inode->i_mapping) {
392 btrfs_err(BTRFS_I(inode)->root->fs_info,
393 "free space cache page truncated");
394 io_ctl_drop_pages(io_ctl);
395 return -EIO;
396 }
397 if (!PageUptodate(page)) {
398 btrfs_err(BTRFS_I(inode)->root->fs_info,
399 "error reading free space cache");
400 io_ctl_drop_pages(io_ctl);
401 return -EIO;
402 }
403 }
404 }
405
406 for (i = 0; i < io_ctl->num_pages; i++) {
407 clear_page_dirty_for_io(io_ctl->pages[i]);
408 set_page_extent_mapped(io_ctl->pages[i]);
409 }
410
411 return 0;
412 }
413
414 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
415 {
416 __le64 *val;
417
418 io_ctl_map_page(io_ctl, 1);
419
420 /*
421 * Skip the csum areas. If we don't check crcs then we just have a
422 * 64bit chunk at the front of the first page.
423 */
424 if (io_ctl->check_crcs) {
425 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
426 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
427 } else {
428 io_ctl->cur += sizeof(u64);
429 io_ctl->size -= sizeof(u64) * 2;
430 }
431
432 val = io_ctl->cur;
433 *val = cpu_to_le64(generation);
434 io_ctl->cur += sizeof(u64);
435 }
436
437 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
438 {
439 __le64 *gen;
440
441 /*
442 * Skip the crc area. If we don't check crcs then we just have a 64bit
443 * chunk at the front of the first page.
444 */
445 if (io_ctl->check_crcs) {
446 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
447 io_ctl->size -= sizeof(u64) +
448 (sizeof(u32) * io_ctl->num_pages);
449 } else {
450 io_ctl->cur += sizeof(u64);
451 io_ctl->size -= sizeof(u64) * 2;
452 }
453
454 gen = io_ctl->cur;
455 if (le64_to_cpu(*gen) != generation) {
456 btrfs_err_rl(io_ctl->fs_info,
457 "space cache generation (%llu) does not match inode (%llu)",
458 *gen, generation);
459 io_ctl_unmap_page(io_ctl);
460 return -EIO;
461 }
462 io_ctl->cur += sizeof(u64);
463 return 0;
464 }
465
466 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
467 {
468 u32 *tmp;
469 u32 crc = ~(u32)0;
470 unsigned offset = 0;
471
472 if (!io_ctl->check_crcs) {
473 io_ctl_unmap_page(io_ctl);
474 return;
475 }
476
477 if (index == 0)
478 offset = sizeof(u32) * io_ctl->num_pages;
479
480 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
481 btrfs_crc32c_final(crc, (u8 *)&crc);
482 io_ctl_unmap_page(io_ctl);
483 tmp = page_address(io_ctl->pages[0]);
484 tmp += index;
485 *tmp = crc;
486 }
487
488 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
489 {
490 u32 *tmp, val;
491 u32 crc = ~(u32)0;
492 unsigned offset = 0;
493
494 if (!io_ctl->check_crcs) {
495 io_ctl_map_page(io_ctl, 0);
496 return 0;
497 }
498
499 if (index == 0)
500 offset = sizeof(u32) * io_ctl->num_pages;
501
502 tmp = page_address(io_ctl->pages[0]);
503 tmp += index;
504 val = *tmp;
505
506 io_ctl_map_page(io_ctl, 0);
507 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
508 btrfs_crc32c_final(crc, (u8 *)&crc);
509 if (val != crc) {
510 btrfs_err_rl(io_ctl->fs_info,
511 "csum mismatch on free space cache");
512 io_ctl_unmap_page(io_ctl);
513 return -EIO;
514 }
515
516 return 0;
517 }
518
519 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
520 void *bitmap)
521 {
522 struct btrfs_free_space_entry *entry;
523
524 if (!io_ctl->cur)
525 return -ENOSPC;
526
527 entry = io_ctl->cur;
528 entry->offset = cpu_to_le64(offset);
529 entry->bytes = cpu_to_le64(bytes);
530 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
531 BTRFS_FREE_SPACE_EXTENT;
532 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
533 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
534
535 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
536 return 0;
537
538 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
539
540 /* No more pages to map */
541 if (io_ctl->index >= io_ctl->num_pages)
542 return 0;
543
544 /* map the next page */
545 io_ctl_map_page(io_ctl, 1);
546 return 0;
547 }
548
549 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
550 {
551 if (!io_ctl->cur)
552 return -ENOSPC;
553
554 /*
555 * If we aren't at the start of the current page, unmap this one and
556 * map the next one if there is any left.
557 */
558 if (io_ctl->cur != io_ctl->orig) {
559 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
560 if (io_ctl->index >= io_ctl->num_pages)
561 return -ENOSPC;
562 io_ctl_map_page(io_ctl, 0);
563 }
564
565 copy_page(io_ctl->cur, bitmap);
566 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
567 if (io_ctl->index < io_ctl->num_pages)
568 io_ctl_map_page(io_ctl, 0);
569 return 0;
570 }
571
572 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
573 {
574 /*
575 * If we're not on the boundary we know we've modified the page and we
576 * need to crc the page.
577 */
578 if (io_ctl->cur != io_ctl->orig)
579 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
580 else
581 io_ctl_unmap_page(io_ctl);
582
583 while (io_ctl->index < io_ctl->num_pages) {
584 io_ctl_map_page(io_ctl, 1);
585 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
586 }
587 }
588
589 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
590 struct btrfs_free_space *entry, u8 *type)
591 {
592 struct btrfs_free_space_entry *e;
593 int ret;
594
595 if (!io_ctl->cur) {
596 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
597 if (ret)
598 return ret;
599 }
600
601 e = io_ctl->cur;
602 entry->offset = le64_to_cpu(e->offset);
603 entry->bytes = le64_to_cpu(e->bytes);
604 *type = e->type;
605 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
606 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
607
608 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
609 return 0;
610
611 io_ctl_unmap_page(io_ctl);
612
613 return 0;
614 }
615
616 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
617 struct btrfs_free_space *entry)
618 {
619 int ret;
620
621 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
622 if (ret)
623 return ret;
624
625 copy_page(entry->bitmap, io_ctl->cur);
626 io_ctl_unmap_page(io_ctl);
627
628 return 0;
629 }
630
631 /*
632 * Since we attach pinned extents after the fact we can have contiguous sections
633 * of free space that are split up in entries. This poses a problem with the
634 * tree logging stuff since it could have allocated across what appears to be 2
635 * entries since we would have merged the entries when adding the pinned extents
636 * back to the free space cache. So run through the space cache that we just
637 * loaded and merge contiguous entries. This will make the log replay stuff not
638 * blow up and it will make for nicer allocator behavior.
639 */
640 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
641 {
642 struct btrfs_free_space *e, *prev = NULL;
643 struct rb_node *n;
644
645 again:
646 spin_lock(&ctl->tree_lock);
647 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
648 e = rb_entry(n, struct btrfs_free_space, offset_index);
649 if (!prev)
650 goto next;
651 if (e->bitmap || prev->bitmap)
652 goto next;
653 if (prev->offset + prev->bytes == e->offset) {
654 unlink_free_space(ctl, prev);
655 unlink_free_space(ctl, e);
656 prev->bytes += e->bytes;
657 kmem_cache_free(btrfs_free_space_cachep, e);
658 link_free_space(ctl, prev);
659 prev = NULL;
660 spin_unlock(&ctl->tree_lock);
661 goto again;
662 }
663 next:
664 prev = e;
665 }
666 spin_unlock(&ctl->tree_lock);
667 }
668
669 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
670 struct btrfs_free_space_ctl *ctl,
671 struct btrfs_path *path, u64 offset)
672 {
673 struct btrfs_fs_info *fs_info = root->fs_info;
674 struct btrfs_free_space_header *header;
675 struct extent_buffer *leaf;
676 struct btrfs_io_ctl io_ctl;
677 struct btrfs_key key;
678 struct btrfs_free_space *e, *n;
679 LIST_HEAD(bitmaps);
680 u64 num_entries;
681 u64 num_bitmaps;
682 u64 generation;
683 u8 type;
684 int ret = 0;
685
686 /* Nothing in the space cache, goodbye */
687 if (!i_size_read(inode))
688 return 0;
689
690 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
691 key.offset = offset;
692 key.type = 0;
693
694 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
695 if (ret < 0)
696 return 0;
697 else if (ret > 0) {
698 btrfs_release_path(path);
699 return 0;
700 }
701
702 ret = -1;
703
704 leaf = path->nodes[0];
705 header = btrfs_item_ptr(leaf, path->slots[0],
706 struct btrfs_free_space_header);
707 num_entries = btrfs_free_space_entries(leaf, header);
708 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
709 generation = btrfs_free_space_generation(leaf, header);
710 btrfs_release_path(path);
711
712 if (!BTRFS_I(inode)->generation) {
713 btrfs_info(fs_info,
714 "the free space cache file (%llu) is invalid, skip it",
715 offset);
716 return 0;
717 }
718
719 if (BTRFS_I(inode)->generation != generation) {
720 btrfs_err(fs_info,
721 "free space inode generation (%llu) did not match free space cache generation (%llu)",
722 BTRFS_I(inode)->generation, generation);
723 return 0;
724 }
725
726 if (!num_entries)
727 return 0;
728
729 ret = io_ctl_init(&io_ctl, inode, 0);
730 if (ret)
731 return ret;
732
733 readahead_cache(inode);
734
735 ret = io_ctl_prepare_pages(&io_ctl, true);
736 if (ret)
737 goto out;
738
739 ret = io_ctl_check_crc(&io_ctl, 0);
740 if (ret)
741 goto free_cache;
742
743 ret = io_ctl_check_generation(&io_ctl, generation);
744 if (ret)
745 goto free_cache;
746
747 while (num_entries) {
748 e = kmem_cache_zalloc(btrfs_free_space_cachep,
749 GFP_NOFS);
750 if (!e)
751 goto free_cache;
752
753 ret = io_ctl_read_entry(&io_ctl, e, &type);
754 if (ret) {
755 kmem_cache_free(btrfs_free_space_cachep, e);
756 goto free_cache;
757 }
758
759 /*
760 * Sync discard ensures that the free space cache is always
761 * trimmed. So when reading this in, the state should reflect
762 * that. We also do this for async as a stop gap for lack of
763 * persistence.
764 */
765 if (btrfs_test_opt(fs_info, DISCARD_SYNC) ||
766 btrfs_test_opt(fs_info, DISCARD_ASYNC))
767 e->trim_state = BTRFS_TRIM_STATE_TRIMMED;
768
769 if (!e->bytes) {
770 kmem_cache_free(btrfs_free_space_cachep, e);
771 goto free_cache;
772 }
773
774 if (type == BTRFS_FREE_SPACE_EXTENT) {
775 spin_lock(&ctl->tree_lock);
776 ret = link_free_space(ctl, e);
777 spin_unlock(&ctl->tree_lock);
778 if (ret) {
779 btrfs_err(fs_info,
780 "Duplicate entries in free space cache, dumping");
781 kmem_cache_free(btrfs_free_space_cachep, e);
782 goto free_cache;
783 }
784 } else {
785 ASSERT(num_bitmaps);
786 num_bitmaps--;
787 e->bitmap = kmem_cache_zalloc(
788 btrfs_free_space_bitmap_cachep, GFP_NOFS);
789 if (!e->bitmap) {
790 kmem_cache_free(
791 btrfs_free_space_cachep, e);
792 goto free_cache;
793 }
794 spin_lock(&ctl->tree_lock);
795 ret = link_free_space(ctl, e);
796 ctl->total_bitmaps++;
797 ctl->op->recalc_thresholds(ctl);
798 spin_unlock(&ctl->tree_lock);
799 if (ret) {
800 btrfs_err(fs_info,
801 "Duplicate entries in free space cache, dumping");
802 kmem_cache_free(btrfs_free_space_cachep, e);
803 goto free_cache;
804 }
805 list_add_tail(&e->list, &bitmaps);
806 }
807
808 num_entries--;
809 }
810
811 io_ctl_unmap_page(&io_ctl);
812
813 /*
814 * We add the bitmaps at the end of the entries in order that
815 * the bitmap entries are added to the cache.
816 */
817 list_for_each_entry_safe(e, n, &bitmaps, list) {
818 list_del_init(&e->list);
819 ret = io_ctl_read_bitmap(&io_ctl, e);
820 if (ret)
821 goto free_cache;
822 e->bitmap_extents = count_bitmap_extents(ctl, e);
823 if (!btrfs_free_space_trimmed(e)) {
824 ctl->discardable_extents[BTRFS_STAT_CURR] +=
825 e->bitmap_extents;
826 ctl->discardable_bytes[BTRFS_STAT_CURR] += e->bytes;
827 }
828 }
829
830 io_ctl_drop_pages(&io_ctl);
831 merge_space_tree(ctl);
832 ret = 1;
833 out:
834 btrfs_discard_update_discardable(ctl->private, ctl);
835 io_ctl_free(&io_ctl);
836 return ret;
837 free_cache:
838 io_ctl_drop_pages(&io_ctl);
839 __btrfs_remove_free_space_cache(ctl);
840 goto out;
841 }
842
843 int load_free_space_cache(struct btrfs_block_group *block_group)
844 {
845 struct btrfs_fs_info *fs_info = block_group->fs_info;
846 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
847 struct inode *inode;
848 struct btrfs_path *path;
849 int ret = 0;
850 bool matched;
851 u64 used = block_group->used;
852
853 /*
854 * If this block group has been marked to be cleared for one reason or
855 * another then we can't trust the on disk cache, so just return.
856 */
857 spin_lock(&block_group->lock);
858 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
859 spin_unlock(&block_group->lock);
860 return 0;
861 }
862 spin_unlock(&block_group->lock);
863
864 path = btrfs_alloc_path();
865 if (!path)
866 return 0;
867 path->search_commit_root = 1;
868 path->skip_locking = 1;
869
870 /*
871 * We must pass a path with search_commit_root set to btrfs_iget in
872 * order to avoid a deadlock when allocating extents for the tree root.
873 *
874 * When we are COWing an extent buffer from the tree root, when looking
875 * for a free extent, at extent-tree.c:find_free_extent(), we can find
876 * block group without its free space cache loaded. When we find one
877 * we must load its space cache which requires reading its free space
878 * cache's inode item from the root tree. If this inode item is located
879 * in the same leaf that we started COWing before, then we end up in
880 * deadlock on the extent buffer (trying to read lock it when we
881 * previously write locked it).
882 *
883 * It's safe to read the inode item using the commit root because
884 * block groups, once loaded, stay in memory forever (until they are
885 * removed) as well as their space caches once loaded. New block groups
886 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
887 * we will never try to read their inode item while the fs is mounted.
888 */
889 inode = lookup_free_space_inode(block_group, path);
890 if (IS_ERR(inode)) {
891 btrfs_free_path(path);
892 return 0;
893 }
894
895 /* We may have converted the inode and made the cache invalid. */
896 spin_lock(&block_group->lock);
897 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
898 spin_unlock(&block_group->lock);
899 btrfs_free_path(path);
900 goto out;
901 }
902 spin_unlock(&block_group->lock);
903
904 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
905 path, block_group->start);
906 btrfs_free_path(path);
907 if (ret <= 0)
908 goto out;
909
910 spin_lock(&ctl->tree_lock);
911 matched = (ctl->free_space == (block_group->length - used -
912 block_group->bytes_super));
913 spin_unlock(&ctl->tree_lock);
914
915 if (!matched) {
916 __btrfs_remove_free_space_cache(ctl);
917 btrfs_warn(fs_info,
918 "block group %llu has wrong amount of free space",
919 block_group->start);
920 ret = -1;
921 }
922 out:
923 if (ret < 0) {
924 /* This cache is bogus, make sure it gets cleared */
925 spin_lock(&block_group->lock);
926 block_group->disk_cache_state = BTRFS_DC_CLEAR;
927 spin_unlock(&block_group->lock);
928 ret = 0;
929
930 btrfs_warn(fs_info,
931 "failed to load free space cache for block group %llu, rebuilding it now",
932 block_group->start);
933 }
934
935 iput(inode);
936 return ret;
937 }
938
939 static noinline_for_stack
940 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
941 struct btrfs_free_space_ctl *ctl,
942 struct btrfs_block_group *block_group,
943 int *entries, int *bitmaps,
944 struct list_head *bitmap_list)
945 {
946 int ret;
947 struct btrfs_free_cluster *cluster = NULL;
948 struct btrfs_free_cluster *cluster_locked = NULL;
949 struct rb_node *node = rb_first(&ctl->free_space_offset);
950 struct btrfs_trim_range *trim_entry;
951
952 /* Get the cluster for this block_group if it exists */
953 if (block_group && !list_empty(&block_group->cluster_list)) {
954 cluster = list_entry(block_group->cluster_list.next,
955 struct btrfs_free_cluster,
956 block_group_list);
957 }
958
959 if (!node && cluster) {
960 cluster_locked = cluster;
961 spin_lock(&cluster_locked->lock);
962 node = rb_first(&cluster->root);
963 cluster = NULL;
964 }
965
966 /* Write out the extent entries */
967 while (node) {
968 struct btrfs_free_space *e;
969
970 e = rb_entry(node, struct btrfs_free_space, offset_index);
971 *entries += 1;
972
973 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
974 e->bitmap);
975 if (ret)
976 goto fail;
977
978 if (e->bitmap) {
979 list_add_tail(&e->list, bitmap_list);
980 *bitmaps += 1;
981 }
982 node = rb_next(node);
983 if (!node && cluster) {
984 node = rb_first(&cluster->root);
985 cluster_locked = cluster;
986 spin_lock(&cluster_locked->lock);
987 cluster = NULL;
988 }
989 }
990 if (cluster_locked) {
991 spin_unlock(&cluster_locked->lock);
992 cluster_locked = NULL;
993 }
994
995 /*
996 * Make sure we don't miss any range that was removed from our rbtree
997 * because trimming is running. Otherwise after a umount+mount (or crash
998 * after committing the transaction) we would leak free space and get
999 * an inconsistent free space cache report from fsck.
1000 */
1001 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
1002 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
1003 trim_entry->bytes, NULL);
1004 if (ret)
1005 goto fail;
1006 *entries += 1;
1007 }
1008
1009 return 0;
1010 fail:
1011 if (cluster_locked)
1012 spin_unlock(&cluster_locked->lock);
1013 return -ENOSPC;
1014 }
1015
1016 static noinline_for_stack int
1017 update_cache_item(struct btrfs_trans_handle *trans,
1018 struct btrfs_root *root,
1019 struct inode *inode,
1020 struct btrfs_path *path, u64 offset,
1021 int entries, int bitmaps)
1022 {
1023 struct btrfs_key key;
1024 struct btrfs_free_space_header *header;
1025 struct extent_buffer *leaf;
1026 int ret;
1027
1028 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1029 key.offset = offset;
1030 key.type = 0;
1031
1032 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1033 if (ret < 0) {
1034 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1035 EXTENT_DELALLOC, 0, 0, NULL);
1036 goto fail;
1037 }
1038 leaf = path->nodes[0];
1039 if (ret > 0) {
1040 struct btrfs_key found_key;
1041 ASSERT(path->slots[0]);
1042 path->slots[0]--;
1043 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1044 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1045 found_key.offset != offset) {
1046 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1047 inode->i_size - 1, EXTENT_DELALLOC, 0,
1048 0, NULL);
1049 btrfs_release_path(path);
1050 goto fail;
1051 }
1052 }
1053
1054 BTRFS_I(inode)->generation = trans->transid;
1055 header = btrfs_item_ptr(leaf, path->slots[0],
1056 struct btrfs_free_space_header);
1057 btrfs_set_free_space_entries(leaf, header, entries);
1058 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1059 btrfs_set_free_space_generation(leaf, header, trans->transid);
1060 btrfs_mark_buffer_dirty(leaf);
1061 btrfs_release_path(path);
1062
1063 return 0;
1064
1065 fail:
1066 return -1;
1067 }
1068
1069 static noinline_for_stack int write_pinned_extent_entries(
1070 struct btrfs_trans_handle *trans,
1071 struct btrfs_block_group *block_group,
1072 struct btrfs_io_ctl *io_ctl,
1073 int *entries)
1074 {
1075 u64 start, extent_start, extent_end, len;
1076 struct extent_io_tree *unpin = NULL;
1077 int ret;
1078
1079 if (!block_group)
1080 return 0;
1081
1082 /*
1083 * We want to add any pinned extents to our free space cache
1084 * so we don't leak the space
1085 *
1086 * We shouldn't have switched the pinned extents yet so this is the
1087 * right one
1088 */
1089 unpin = &trans->transaction->pinned_extents;
1090
1091 start = block_group->start;
1092
1093 while (start < block_group->start + block_group->length) {
1094 ret = find_first_extent_bit(unpin, start,
1095 &extent_start, &extent_end,
1096 EXTENT_DIRTY, NULL);
1097 if (ret)
1098 return 0;
1099
1100 /* This pinned extent is out of our range */
1101 if (extent_start >= block_group->start + block_group->length)
1102 return 0;
1103
1104 extent_start = max(extent_start, start);
1105 extent_end = min(block_group->start + block_group->length,
1106 extent_end + 1);
1107 len = extent_end - extent_start;
1108
1109 *entries += 1;
1110 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1111 if (ret)
1112 return -ENOSPC;
1113
1114 start = extent_end;
1115 }
1116
1117 return 0;
1118 }
1119
1120 static noinline_for_stack int
1121 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1122 {
1123 struct btrfs_free_space *entry, *next;
1124 int ret;
1125
1126 /* Write out the bitmaps */
1127 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1128 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1129 if (ret)
1130 return -ENOSPC;
1131 list_del_init(&entry->list);
1132 }
1133
1134 return 0;
1135 }
1136
1137 static int flush_dirty_cache(struct inode *inode)
1138 {
1139 int ret;
1140
1141 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1142 if (ret)
1143 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1144 EXTENT_DELALLOC, 0, 0, NULL);
1145
1146 return ret;
1147 }
1148
1149 static void noinline_for_stack
1150 cleanup_bitmap_list(struct list_head *bitmap_list)
1151 {
1152 struct btrfs_free_space *entry, *next;
1153
1154 list_for_each_entry_safe(entry, next, bitmap_list, list)
1155 list_del_init(&entry->list);
1156 }
1157
1158 static void noinline_for_stack
1159 cleanup_write_cache_enospc(struct inode *inode,
1160 struct btrfs_io_ctl *io_ctl,
1161 struct extent_state **cached_state)
1162 {
1163 io_ctl_drop_pages(io_ctl);
1164 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1165 i_size_read(inode) - 1, cached_state);
1166 }
1167
1168 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1169 struct btrfs_trans_handle *trans,
1170 struct btrfs_block_group *block_group,
1171 struct btrfs_io_ctl *io_ctl,
1172 struct btrfs_path *path, u64 offset)
1173 {
1174 int ret;
1175 struct inode *inode = io_ctl->inode;
1176
1177 if (!inode)
1178 return 0;
1179
1180 /* Flush the dirty pages in the cache file. */
1181 ret = flush_dirty_cache(inode);
1182 if (ret)
1183 goto out;
1184
1185 /* Update the cache item to tell everyone this cache file is valid. */
1186 ret = update_cache_item(trans, root, inode, path, offset,
1187 io_ctl->entries, io_ctl->bitmaps);
1188 out:
1189 io_ctl_free(io_ctl);
1190 if (ret) {
1191 invalidate_inode_pages2(inode->i_mapping);
1192 BTRFS_I(inode)->generation = 0;
1193 if (block_group)
1194 btrfs_debug(root->fs_info,
1195 "failed to write free space cache for block group %llu error %d",
1196 block_group->start, ret);
1197 }
1198 btrfs_update_inode(trans, root, inode);
1199
1200 if (block_group) {
1201 /* the dirty list is protected by the dirty_bgs_lock */
1202 spin_lock(&trans->transaction->dirty_bgs_lock);
1203
1204 /* the disk_cache_state is protected by the block group lock */
1205 spin_lock(&block_group->lock);
1206
1207 /*
1208 * only mark this as written if we didn't get put back on
1209 * the dirty list while waiting for IO. Otherwise our
1210 * cache state won't be right, and we won't get written again
1211 */
1212 if (!ret && list_empty(&block_group->dirty_list))
1213 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1214 else if (ret)
1215 block_group->disk_cache_state = BTRFS_DC_ERROR;
1216
1217 spin_unlock(&block_group->lock);
1218 spin_unlock(&trans->transaction->dirty_bgs_lock);
1219 io_ctl->inode = NULL;
1220 iput(inode);
1221 }
1222
1223 return ret;
1224
1225 }
1226
1227 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
1228 struct btrfs_trans_handle *trans,
1229 struct btrfs_io_ctl *io_ctl,
1230 struct btrfs_path *path)
1231 {
1232 return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
1233 }
1234
1235 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1236 struct btrfs_block_group *block_group,
1237 struct btrfs_path *path)
1238 {
1239 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1240 block_group, &block_group->io_ctl,
1241 path, block_group->start);
1242 }
1243
1244 /**
1245 * __btrfs_write_out_cache - write out cached info to an inode
1246 * @root - the root the inode belongs to
1247 * @ctl - the free space cache we are going to write out
1248 * @block_group - the block_group for this cache if it belongs to a block_group
1249 * @trans - the trans handle
1250 *
1251 * This function writes out a free space cache struct to disk for quick recovery
1252 * on mount. This will return 0 if it was successful in writing the cache out,
1253 * or an errno if it was not.
1254 */
1255 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1256 struct btrfs_free_space_ctl *ctl,
1257 struct btrfs_block_group *block_group,
1258 struct btrfs_io_ctl *io_ctl,
1259 struct btrfs_trans_handle *trans)
1260 {
1261 struct extent_state *cached_state = NULL;
1262 LIST_HEAD(bitmap_list);
1263 int entries = 0;
1264 int bitmaps = 0;
1265 int ret;
1266 int must_iput = 0;
1267
1268 if (!i_size_read(inode))
1269 return -EIO;
1270
1271 WARN_ON(io_ctl->pages);
1272 ret = io_ctl_init(io_ctl, inode, 1);
1273 if (ret)
1274 return ret;
1275
1276 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1277 down_write(&block_group->data_rwsem);
1278 spin_lock(&block_group->lock);
1279 if (block_group->delalloc_bytes) {
1280 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1281 spin_unlock(&block_group->lock);
1282 up_write(&block_group->data_rwsem);
1283 BTRFS_I(inode)->generation = 0;
1284 ret = 0;
1285 must_iput = 1;
1286 goto out;
1287 }
1288 spin_unlock(&block_group->lock);
1289 }
1290
1291 /* Lock all pages first so we can lock the extent safely. */
1292 ret = io_ctl_prepare_pages(io_ctl, false);
1293 if (ret)
1294 goto out_unlock;
1295
1296 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1297 &cached_state);
1298
1299 io_ctl_set_generation(io_ctl, trans->transid);
1300
1301 mutex_lock(&ctl->cache_writeout_mutex);
1302 /* Write out the extent entries in the free space cache */
1303 spin_lock(&ctl->tree_lock);
1304 ret = write_cache_extent_entries(io_ctl, ctl,
1305 block_group, &entries, &bitmaps,
1306 &bitmap_list);
1307 if (ret)
1308 goto out_nospc_locked;
1309
1310 /*
1311 * Some spaces that are freed in the current transaction are pinned,
1312 * they will be added into free space cache after the transaction is
1313 * committed, we shouldn't lose them.
1314 *
1315 * If this changes while we are working we'll get added back to
1316 * the dirty list and redo it. No locking needed
1317 */
1318 ret = write_pinned_extent_entries(trans, block_group, io_ctl, &entries);
1319 if (ret)
1320 goto out_nospc_locked;
1321
1322 /*
1323 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1324 * locked while doing it because a concurrent trim can be manipulating
1325 * or freeing the bitmap.
1326 */
1327 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1328 spin_unlock(&ctl->tree_lock);
1329 mutex_unlock(&ctl->cache_writeout_mutex);
1330 if (ret)
1331 goto out_nospc;
1332
1333 /* Zero out the rest of the pages just to make sure */
1334 io_ctl_zero_remaining_pages(io_ctl);
1335
1336 /* Everything is written out, now we dirty the pages in the file. */
1337 ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
1338 i_size_read(inode), &cached_state);
1339 if (ret)
1340 goto out_nospc;
1341
1342 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1343 up_write(&block_group->data_rwsem);
1344 /*
1345 * Release the pages and unlock the extent, we will flush
1346 * them out later
1347 */
1348 io_ctl_drop_pages(io_ctl);
1349
1350 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1351 i_size_read(inode) - 1, &cached_state);
1352
1353 /*
1354 * at this point the pages are under IO and we're happy,
1355 * The caller is responsible for waiting on them and updating the
1356 * the cache and the inode
1357 */
1358 io_ctl->entries = entries;
1359 io_ctl->bitmaps = bitmaps;
1360
1361 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1362 if (ret)
1363 goto out;
1364
1365 return 0;
1366
1367 out_nospc_locked:
1368 cleanup_bitmap_list(&bitmap_list);
1369 spin_unlock(&ctl->tree_lock);
1370 mutex_unlock(&ctl->cache_writeout_mutex);
1371
1372 out_nospc:
1373 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1374
1375 out_unlock:
1376 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1377 up_write(&block_group->data_rwsem);
1378
1379 out:
1380 io_ctl->inode = NULL;
1381 io_ctl_free(io_ctl);
1382 if (ret) {
1383 invalidate_inode_pages2(inode->i_mapping);
1384 BTRFS_I(inode)->generation = 0;
1385 }
1386 btrfs_update_inode(trans, root, inode);
1387 if (must_iput)
1388 iput(inode);
1389 return ret;
1390 }
1391
1392 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
1393 struct btrfs_block_group *block_group,
1394 struct btrfs_path *path)
1395 {
1396 struct btrfs_fs_info *fs_info = trans->fs_info;
1397 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1398 struct inode *inode;
1399 int ret = 0;
1400
1401 spin_lock(&block_group->lock);
1402 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1403 spin_unlock(&block_group->lock);
1404 return 0;
1405 }
1406 spin_unlock(&block_group->lock);
1407
1408 inode = lookup_free_space_inode(block_group, path);
1409 if (IS_ERR(inode))
1410 return 0;
1411
1412 ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
1413 block_group, &block_group->io_ctl, trans);
1414 if (ret) {
1415 btrfs_debug(fs_info,
1416 "failed to write free space cache for block group %llu error %d",
1417 block_group->start, ret);
1418 spin_lock(&block_group->lock);
1419 block_group->disk_cache_state = BTRFS_DC_ERROR;
1420 spin_unlock(&block_group->lock);
1421
1422 block_group->io_ctl.inode = NULL;
1423 iput(inode);
1424 }
1425
1426 /*
1427 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1428 * to wait for IO and put the inode
1429 */
1430
1431 return ret;
1432 }
1433
1434 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1435 u64 offset)
1436 {
1437 ASSERT(offset >= bitmap_start);
1438 offset -= bitmap_start;
1439 return (unsigned long)(div_u64(offset, unit));
1440 }
1441
1442 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1443 {
1444 return (unsigned long)(div_u64(bytes, unit));
1445 }
1446
1447 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1448 u64 offset)
1449 {
1450 u64 bitmap_start;
1451 u64 bytes_per_bitmap;
1452
1453 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1454 bitmap_start = offset - ctl->start;
1455 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1456 bitmap_start *= bytes_per_bitmap;
1457 bitmap_start += ctl->start;
1458
1459 return bitmap_start;
1460 }
1461
1462 static int tree_insert_offset(struct rb_root *root, u64 offset,
1463 struct rb_node *node, int bitmap)
1464 {
1465 struct rb_node **p = &root->rb_node;
1466 struct rb_node *parent = NULL;
1467 struct btrfs_free_space *info;
1468
1469 while (*p) {
1470 parent = *p;
1471 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1472
1473 if (offset < info->offset) {
1474 p = &(*p)->rb_left;
1475 } else if (offset > info->offset) {
1476 p = &(*p)->rb_right;
1477 } else {
1478 /*
1479 * we could have a bitmap entry and an extent entry
1480 * share the same offset. If this is the case, we want
1481 * the extent entry to always be found first if we do a
1482 * linear search through the tree, since we want to have
1483 * the quickest allocation time, and allocating from an
1484 * extent is faster than allocating from a bitmap. So
1485 * if we're inserting a bitmap and we find an entry at
1486 * this offset, we want to go right, or after this entry
1487 * logically. If we are inserting an extent and we've
1488 * found a bitmap, we want to go left, or before
1489 * logically.
1490 */
1491 if (bitmap) {
1492 if (info->bitmap) {
1493 WARN_ON_ONCE(1);
1494 return -EEXIST;
1495 }
1496 p = &(*p)->rb_right;
1497 } else {
1498 if (!info->bitmap) {
1499 WARN_ON_ONCE(1);
1500 return -EEXIST;
1501 }
1502 p = &(*p)->rb_left;
1503 }
1504 }
1505 }
1506
1507 rb_link_node(node, parent, p);
1508 rb_insert_color(node, root);
1509
1510 return 0;
1511 }
1512
1513 /*
1514 * searches the tree for the given offset.
1515 *
1516 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1517 * want a section that has at least bytes size and comes at or after the given
1518 * offset.
1519 */
1520 static struct btrfs_free_space *
1521 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1522 u64 offset, int bitmap_only, int fuzzy)
1523 {
1524 struct rb_node *n = ctl->free_space_offset.rb_node;
1525 struct btrfs_free_space *entry, *prev = NULL;
1526
1527 /* find entry that is closest to the 'offset' */
1528 while (1) {
1529 if (!n) {
1530 entry = NULL;
1531 break;
1532 }
1533
1534 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1535 prev = entry;
1536
1537 if (offset < entry->offset)
1538 n = n->rb_left;
1539 else if (offset > entry->offset)
1540 n = n->rb_right;
1541 else
1542 break;
1543 }
1544
1545 if (bitmap_only) {
1546 if (!entry)
1547 return NULL;
1548 if (entry->bitmap)
1549 return entry;
1550
1551 /*
1552 * bitmap entry and extent entry may share same offset,
1553 * in that case, bitmap entry comes after extent entry.
1554 */
1555 n = rb_next(n);
1556 if (!n)
1557 return NULL;
1558 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1559 if (entry->offset != offset)
1560 return NULL;
1561
1562 WARN_ON(!entry->bitmap);
1563 return entry;
1564 } else if (entry) {
1565 if (entry->bitmap) {
1566 /*
1567 * if previous extent entry covers the offset,
1568 * we should return it instead of the bitmap entry
1569 */
1570 n = rb_prev(&entry->offset_index);
1571 if (n) {
1572 prev = rb_entry(n, struct btrfs_free_space,
1573 offset_index);
1574 if (!prev->bitmap &&
1575 prev->offset + prev->bytes > offset)
1576 entry = prev;
1577 }
1578 }
1579 return entry;
1580 }
1581
1582 if (!prev)
1583 return NULL;
1584
1585 /* find last entry before the 'offset' */
1586 entry = prev;
1587 if (entry->offset > offset) {
1588 n = rb_prev(&entry->offset_index);
1589 if (n) {
1590 entry = rb_entry(n, struct btrfs_free_space,
1591 offset_index);
1592 ASSERT(entry->offset <= offset);
1593 } else {
1594 if (fuzzy)
1595 return entry;
1596 else
1597 return NULL;
1598 }
1599 }
1600
1601 if (entry->bitmap) {
1602 n = rb_prev(&entry->offset_index);
1603 if (n) {
1604 prev = rb_entry(n, struct btrfs_free_space,
1605 offset_index);
1606 if (!prev->bitmap &&
1607 prev->offset + prev->bytes > offset)
1608 return prev;
1609 }
1610 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1611 return entry;
1612 } else if (entry->offset + entry->bytes > offset)
1613 return entry;
1614
1615 if (!fuzzy)
1616 return NULL;
1617
1618 while (1) {
1619 if (entry->bitmap) {
1620 if (entry->offset + BITS_PER_BITMAP *
1621 ctl->unit > offset)
1622 break;
1623 } else {
1624 if (entry->offset + entry->bytes > offset)
1625 break;
1626 }
1627
1628 n = rb_next(&entry->offset_index);
1629 if (!n)
1630 return NULL;
1631 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1632 }
1633 return entry;
1634 }
1635
1636 static inline void
1637 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1638 struct btrfs_free_space *info)
1639 {
1640 rb_erase(&info->offset_index, &ctl->free_space_offset);
1641 ctl->free_extents--;
1642
1643 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1644 ctl->discardable_extents[BTRFS_STAT_CURR]--;
1645 ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes;
1646 }
1647 }
1648
1649 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1650 struct btrfs_free_space *info)
1651 {
1652 __unlink_free_space(ctl, info);
1653 ctl->free_space -= info->bytes;
1654 }
1655
1656 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1657 struct btrfs_free_space *info)
1658 {
1659 int ret = 0;
1660
1661 ASSERT(info->bytes || info->bitmap);
1662 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1663 &info->offset_index, (info->bitmap != NULL));
1664 if (ret)
1665 return ret;
1666
1667 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1668 ctl->discardable_extents[BTRFS_STAT_CURR]++;
1669 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
1670 }
1671
1672 ctl->free_space += info->bytes;
1673 ctl->free_extents++;
1674 return ret;
1675 }
1676
1677 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1678 {
1679 struct btrfs_block_group *block_group = ctl->private;
1680 u64 max_bytes;
1681 u64 bitmap_bytes;
1682 u64 extent_bytes;
1683 u64 size = block_group->length;
1684 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1685 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1686
1687 max_bitmaps = max_t(u64, max_bitmaps, 1);
1688
1689 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1690
1691 /*
1692 * We are trying to keep the total amount of memory used per 1GiB of
1693 * space to be MAX_CACHE_BYTES_PER_GIG. However, with a reclamation
1694 * mechanism of pulling extents >= FORCE_EXTENT_THRESHOLD out of
1695 * bitmaps, we may end up using more memory than this.
1696 */
1697 if (size < SZ_1G)
1698 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1699 else
1700 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1701
1702 bitmap_bytes = ctl->total_bitmaps * ctl->unit;
1703
1704 /*
1705 * we want the extent entry threshold to always be at most 1/2 the max
1706 * bytes we can have, or whatever is less than that.
1707 */
1708 extent_bytes = max_bytes - bitmap_bytes;
1709 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1710
1711 ctl->extents_thresh =
1712 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1713 }
1714
1715 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1716 struct btrfs_free_space *info,
1717 u64 offset, u64 bytes)
1718 {
1719 unsigned long start, count, end;
1720 int extent_delta = -1;
1721
1722 start = offset_to_bit(info->offset, ctl->unit, offset);
1723 count = bytes_to_bits(bytes, ctl->unit);
1724 end = start + count;
1725 ASSERT(end <= BITS_PER_BITMAP);
1726
1727 bitmap_clear(info->bitmap, start, count);
1728
1729 info->bytes -= bytes;
1730 if (info->max_extent_size > ctl->unit)
1731 info->max_extent_size = 0;
1732
1733 if (start && test_bit(start - 1, info->bitmap))
1734 extent_delta++;
1735
1736 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1737 extent_delta++;
1738
1739 info->bitmap_extents += extent_delta;
1740 if (!btrfs_free_space_trimmed(info)) {
1741 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1742 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
1743 }
1744 }
1745
1746 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1747 struct btrfs_free_space *info, u64 offset,
1748 u64 bytes)
1749 {
1750 __bitmap_clear_bits(ctl, info, offset, bytes);
1751 ctl->free_space -= bytes;
1752 }
1753
1754 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1755 struct btrfs_free_space *info, u64 offset,
1756 u64 bytes)
1757 {
1758 unsigned long start, count, end;
1759 int extent_delta = 1;
1760
1761 start = offset_to_bit(info->offset, ctl->unit, offset);
1762 count = bytes_to_bits(bytes, ctl->unit);
1763 end = start + count;
1764 ASSERT(end <= BITS_PER_BITMAP);
1765
1766 bitmap_set(info->bitmap, start, count);
1767
1768 info->bytes += bytes;
1769 ctl->free_space += bytes;
1770
1771 if (start && test_bit(start - 1, info->bitmap))
1772 extent_delta--;
1773
1774 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1775 extent_delta--;
1776
1777 info->bitmap_extents += extent_delta;
1778 if (!btrfs_free_space_trimmed(info)) {
1779 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1780 ctl->discardable_bytes[BTRFS_STAT_CURR] += bytes;
1781 }
1782 }
1783
1784 /*
1785 * If we can not find suitable extent, we will use bytes to record
1786 * the size of the max extent.
1787 */
1788 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1789 struct btrfs_free_space *bitmap_info, u64 *offset,
1790 u64 *bytes, bool for_alloc)
1791 {
1792 unsigned long found_bits = 0;
1793 unsigned long max_bits = 0;
1794 unsigned long bits, i;
1795 unsigned long next_zero;
1796 unsigned long extent_bits;
1797
1798 /*
1799 * Skip searching the bitmap if we don't have a contiguous section that
1800 * is large enough for this allocation.
1801 */
1802 if (for_alloc &&
1803 bitmap_info->max_extent_size &&
1804 bitmap_info->max_extent_size < *bytes) {
1805 *bytes = bitmap_info->max_extent_size;
1806 return -1;
1807 }
1808
1809 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1810 max_t(u64, *offset, bitmap_info->offset));
1811 bits = bytes_to_bits(*bytes, ctl->unit);
1812
1813 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1814 if (for_alloc && bits == 1) {
1815 found_bits = 1;
1816 break;
1817 }
1818 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1819 BITS_PER_BITMAP, i);
1820 extent_bits = next_zero - i;
1821 if (extent_bits >= bits) {
1822 found_bits = extent_bits;
1823 break;
1824 } else if (extent_bits > max_bits) {
1825 max_bits = extent_bits;
1826 }
1827 i = next_zero;
1828 }
1829
1830 if (found_bits) {
1831 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1832 *bytes = (u64)(found_bits) * ctl->unit;
1833 return 0;
1834 }
1835
1836 *bytes = (u64)(max_bits) * ctl->unit;
1837 bitmap_info->max_extent_size = *bytes;
1838 return -1;
1839 }
1840
1841 static inline u64 get_max_extent_size(struct btrfs_free_space *entry)
1842 {
1843 if (entry->bitmap)
1844 return entry->max_extent_size;
1845 return entry->bytes;
1846 }
1847
1848 /* Cache the size of the max extent in bytes */
1849 static struct btrfs_free_space *
1850 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1851 unsigned long align, u64 *max_extent_size)
1852 {
1853 struct btrfs_free_space *entry;
1854 struct rb_node *node;
1855 u64 tmp;
1856 u64 align_off;
1857 int ret;
1858
1859 if (!ctl->free_space_offset.rb_node)
1860 goto out;
1861
1862 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1863 if (!entry)
1864 goto out;
1865
1866 for (node = &entry->offset_index; node; node = rb_next(node)) {
1867 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1868 if (entry->bytes < *bytes) {
1869 *max_extent_size = max(get_max_extent_size(entry),
1870 *max_extent_size);
1871 continue;
1872 }
1873
1874 /* make sure the space returned is big enough
1875 * to match our requested alignment
1876 */
1877 if (*bytes >= align) {
1878 tmp = entry->offset - ctl->start + align - 1;
1879 tmp = div64_u64(tmp, align);
1880 tmp = tmp * align + ctl->start;
1881 align_off = tmp - entry->offset;
1882 } else {
1883 align_off = 0;
1884 tmp = entry->offset;
1885 }
1886
1887 if (entry->bytes < *bytes + align_off) {
1888 *max_extent_size = max(get_max_extent_size(entry),
1889 *max_extent_size);
1890 continue;
1891 }
1892
1893 if (entry->bitmap) {
1894 u64 size = *bytes;
1895
1896 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1897 if (!ret) {
1898 *offset = tmp;
1899 *bytes = size;
1900 return entry;
1901 } else {
1902 *max_extent_size =
1903 max(get_max_extent_size(entry),
1904 *max_extent_size);
1905 }
1906 continue;
1907 }
1908
1909 *offset = tmp;
1910 *bytes = entry->bytes - align_off;
1911 return entry;
1912 }
1913 out:
1914 return NULL;
1915 }
1916
1917 static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl,
1918 struct btrfs_free_space *bitmap_info)
1919 {
1920 struct btrfs_block_group *block_group = ctl->private;
1921 u64 bytes = bitmap_info->bytes;
1922 unsigned int rs, re;
1923 int count = 0;
1924
1925 if (!block_group || !bytes)
1926 return count;
1927
1928 bitmap_for_each_set_region(bitmap_info->bitmap, rs, re, 0,
1929 BITS_PER_BITMAP) {
1930 bytes -= (rs - re) * ctl->unit;
1931 count++;
1932
1933 if (!bytes)
1934 break;
1935 }
1936
1937 return count;
1938 }
1939
1940 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1941 struct btrfs_free_space *info, u64 offset)
1942 {
1943 info->offset = offset_to_bitmap(ctl, offset);
1944 info->bytes = 0;
1945 info->bitmap_extents = 0;
1946 INIT_LIST_HEAD(&info->list);
1947 link_free_space(ctl, info);
1948 ctl->total_bitmaps++;
1949
1950 ctl->op->recalc_thresholds(ctl);
1951 }
1952
1953 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1954 struct btrfs_free_space *bitmap_info)
1955 {
1956 /*
1957 * Normally when this is called, the bitmap is completely empty. However,
1958 * if we are blowing up the free space cache for one reason or another
1959 * via __btrfs_remove_free_space_cache(), then it may not be freed and
1960 * we may leave stats on the table.
1961 */
1962 if (bitmap_info->bytes && !btrfs_free_space_trimmed(bitmap_info)) {
1963 ctl->discardable_extents[BTRFS_STAT_CURR] -=
1964 bitmap_info->bitmap_extents;
1965 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bitmap_info->bytes;
1966
1967 }
1968 unlink_free_space(ctl, bitmap_info);
1969 kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
1970 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1971 ctl->total_bitmaps--;
1972 ctl->op->recalc_thresholds(ctl);
1973 }
1974
1975 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1976 struct btrfs_free_space *bitmap_info,
1977 u64 *offset, u64 *bytes)
1978 {
1979 u64 end;
1980 u64 search_start, search_bytes;
1981 int ret;
1982
1983 again:
1984 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1985
1986 /*
1987 * We need to search for bits in this bitmap. We could only cover some
1988 * of the extent in this bitmap thanks to how we add space, so we need
1989 * to search for as much as it as we can and clear that amount, and then
1990 * go searching for the next bit.
1991 */
1992 search_start = *offset;
1993 search_bytes = ctl->unit;
1994 search_bytes = min(search_bytes, end - search_start + 1);
1995 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1996 false);
1997 if (ret < 0 || search_start != *offset)
1998 return -EINVAL;
1999
2000 /* We may have found more bits than what we need */
2001 search_bytes = min(search_bytes, *bytes);
2002
2003 /* Cannot clear past the end of the bitmap */
2004 search_bytes = min(search_bytes, end - search_start + 1);
2005
2006 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
2007 *offset += search_bytes;
2008 *bytes -= search_bytes;
2009
2010 if (*bytes) {
2011 struct rb_node *next = rb_next(&bitmap_info->offset_index);
2012 if (!bitmap_info->bytes)
2013 free_bitmap(ctl, bitmap_info);
2014
2015 /*
2016 * no entry after this bitmap, but we still have bytes to
2017 * remove, so something has gone wrong.
2018 */
2019 if (!next)
2020 return -EINVAL;
2021
2022 bitmap_info = rb_entry(next, struct btrfs_free_space,
2023 offset_index);
2024
2025 /*
2026 * if the next entry isn't a bitmap we need to return to let the
2027 * extent stuff do its work.
2028 */
2029 if (!bitmap_info->bitmap)
2030 return -EAGAIN;
2031
2032 /*
2033 * Ok the next item is a bitmap, but it may not actually hold
2034 * the information for the rest of this free space stuff, so
2035 * look for it, and if we don't find it return so we can try
2036 * everything over again.
2037 */
2038 search_start = *offset;
2039 search_bytes = ctl->unit;
2040 ret = search_bitmap(ctl, bitmap_info, &search_start,
2041 &search_bytes, false);
2042 if (ret < 0 || search_start != *offset)
2043 return -EAGAIN;
2044
2045 goto again;
2046 } else if (!bitmap_info->bytes)
2047 free_bitmap(ctl, bitmap_info);
2048
2049 return 0;
2050 }
2051
2052 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
2053 struct btrfs_free_space *info, u64 offset,
2054 u64 bytes, enum btrfs_trim_state trim_state)
2055 {
2056 u64 bytes_to_set = 0;
2057 u64 end;
2058
2059 /*
2060 * This is a tradeoff to make bitmap trim state minimal. We mark the
2061 * whole bitmap untrimmed if at any point we add untrimmed regions.
2062 */
2063 if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) {
2064 if (btrfs_free_space_trimmed(info)) {
2065 ctl->discardable_extents[BTRFS_STAT_CURR] +=
2066 info->bitmap_extents;
2067 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
2068 }
2069 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2070 }
2071
2072 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
2073
2074 bytes_to_set = min(end - offset, bytes);
2075
2076 bitmap_set_bits(ctl, info, offset, bytes_to_set);
2077
2078 /*
2079 * We set some bytes, we have no idea what the max extent size is
2080 * anymore.
2081 */
2082 info->max_extent_size = 0;
2083
2084 return bytes_to_set;
2085
2086 }
2087
2088 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
2089 struct btrfs_free_space *info)
2090 {
2091 struct btrfs_block_group *block_group = ctl->private;
2092 struct btrfs_fs_info *fs_info = block_group->fs_info;
2093 bool forced = false;
2094
2095 #ifdef CONFIG_BTRFS_DEBUG
2096 if (btrfs_should_fragment_free_space(block_group))
2097 forced = true;
2098 #endif
2099
2100 /* This is a way to reclaim large regions from the bitmaps. */
2101 if (!forced && info->bytes >= FORCE_EXTENT_THRESHOLD)
2102 return false;
2103
2104 /*
2105 * If we are below the extents threshold then we can add this as an
2106 * extent, and don't have to deal with the bitmap
2107 */
2108 if (!forced && ctl->free_extents < ctl->extents_thresh) {
2109 /*
2110 * If this block group has some small extents we don't want to
2111 * use up all of our free slots in the cache with them, we want
2112 * to reserve them to larger extents, however if we have plenty
2113 * of cache left then go ahead an dadd them, no sense in adding
2114 * the overhead of a bitmap if we don't have to.
2115 */
2116 if (info->bytes <= fs_info->sectorsize * 8) {
2117 if (ctl->free_extents * 3 <= ctl->extents_thresh)
2118 return false;
2119 } else {
2120 return false;
2121 }
2122 }
2123
2124 /*
2125 * The original block groups from mkfs can be really small, like 8
2126 * megabytes, so don't bother with a bitmap for those entries. However
2127 * some block groups can be smaller than what a bitmap would cover but
2128 * are still large enough that they could overflow the 32k memory limit,
2129 * so allow those block groups to still be allowed to have a bitmap
2130 * entry.
2131 */
2132 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->length)
2133 return false;
2134
2135 return true;
2136 }
2137
2138 static const struct btrfs_free_space_op free_space_op = {
2139 .recalc_thresholds = recalculate_thresholds,
2140 .use_bitmap = use_bitmap,
2141 };
2142
2143 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2144 struct btrfs_free_space *info)
2145 {
2146 struct btrfs_free_space *bitmap_info;
2147 struct btrfs_block_group *block_group = NULL;
2148 int added = 0;
2149 u64 bytes, offset, bytes_added;
2150 enum btrfs_trim_state trim_state;
2151 int ret;
2152
2153 bytes = info->bytes;
2154 offset = info->offset;
2155 trim_state = info->trim_state;
2156
2157 if (!ctl->op->use_bitmap(ctl, info))
2158 return 0;
2159
2160 if (ctl->op == &free_space_op)
2161 block_group = ctl->private;
2162 again:
2163 /*
2164 * Since we link bitmaps right into the cluster we need to see if we
2165 * have a cluster here, and if so and it has our bitmap we need to add
2166 * the free space to that bitmap.
2167 */
2168 if (block_group && !list_empty(&block_group->cluster_list)) {
2169 struct btrfs_free_cluster *cluster;
2170 struct rb_node *node;
2171 struct btrfs_free_space *entry;
2172
2173 cluster = list_entry(block_group->cluster_list.next,
2174 struct btrfs_free_cluster,
2175 block_group_list);
2176 spin_lock(&cluster->lock);
2177 node = rb_first(&cluster->root);
2178 if (!node) {
2179 spin_unlock(&cluster->lock);
2180 goto no_cluster_bitmap;
2181 }
2182
2183 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2184 if (!entry->bitmap) {
2185 spin_unlock(&cluster->lock);
2186 goto no_cluster_bitmap;
2187 }
2188
2189 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2190 bytes_added = add_bytes_to_bitmap(ctl, entry, offset,
2191 bytes, trim_state);
2192 bytes -= bytes_added;
2193 offset += bytes_added;
2194 }
2195 spin_unlock(&cluster->lock);
2196 if (!bytes) {
2197 ret = 1;
2198 goto out;
2199 }
2200 }
2201
2202 no_cluster_bitmap:
2203 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2204 1, 0);
2205 if (!bitmap_info) {
2206 ASSERT(added == 0);
2207 goto new_bitmap;
2208 }
2209
2210 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
2211 trim_state);
2212 bytes -= bytes_added;
2213 offset += bytes_added;
2214 added = 0;
2215
2216 if (!bytes) {
2217 ret = 1;
2218 goto out;
2219 } else
2220 goto again;
2221
2222 new_bitmap:
2223 if (info && info->bitmap) {
2224 add_new_bitmap(ctl, info, offset);
2225 added = 1;
2226 info = NULL;
2227 goto again;
2228 } else {
2229 spin_unlock(&ctl->tree_lock);
2230
2231 /* no pre-allocated info, allocate a new one */
2232 if (!info) {
2233 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2234 GFP_NOFS);
2235 if (!info) {
2236 spin_lock(&ctl->tree_lock);
2237 ret = -ENOMEM;
2238 goto out;
2239 }
2240 }
2241
2242 /* allocate the bitmap */
2243 info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
2244 GFP_NOFS);
2245 info->trim_state = BTRFS_TRIM_STATE_TRIMMED;
2246 spin_lock(&ctl->tree_lock);
2247 if (!info->bitmap) {
2248 ret = -ENOMEM;
2249 goto out;
2250 }
2251 goto again;
2252 }
2253
2254 out:
2255 if (info) {
2256 if (info->bitmap)
2257 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2258 info->bitmap);
2259 kmem_cache_free(btrfs_free_space_cachep, info);
2260 }
2261
2262 return ret;
2263 }
2264
2265 /*
2266 * Free space merging rules:
2267 * 1) Merge trimmed areas together
2268 * 2) Let untrimmed areas coalesce with trimmed areas
2269 * 3) Always pull neighboring regions from bitmaps
2270 *
2271 * The above rules are for when we merge free space based on btrfs_trim_state.
2272 * Rules 2 and 3 are subtle because they are suboptimal, but are done for the
2273 * same reason: to promote larger extent regions which makes life easier for
2274 * find_free_extent(). Rule 2 enables coalescing based on the common path
2275 * being returning free space from btrfs_finish_extent_commit(). So when free
2276 * space is trimmed, it will prevent aggregating trimmed new region and
2277 * untrimmed regions in the rb_tree. Rule 3 is purely to obtain larger extents
2278 * and provide find_free_extent() with the largest extents possible hoping for
2279 * the reuse path.
2280 */
2281 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2282 struct btrfs_free_space *info, bool update_stat)
2283 {
2284 struct btrfs_free_space *left_info;
2285 struct btrfs_free_space *right_info;
2286 bool merged = false;
2287 u64 offset = info->offset;
2288 u64 bytes = info->bytes;
2289 const bool is_trimmed = btrfs_free_space_trimmed(info);
2290
2291 /*
2292 * first we want to see if there is free space adjacent to the range we
2293 * are adding, if there is remove that struct and add a new one to
2294 * cover the entire range
2295 */
2296 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2297 if (right_info && rb_prev(&right_info->offset_index))
2298 left_info = rb_entry(rb_prev(&right_info->offset_index),
2299 struct btrfs_free_space, offset_index);
2300 else
2301 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2302
2303 /* See try_merge_free_space() comment. */
2304 if (right_info && !right_info->bitmap &&
2305 (!is_trimmed || btrfs_free_space_trimmed(right_info))) {
2306 if (update_stat)
2307 unlink_free_space(ctl, right_info);
2308 else
2309 __unlink_free_space(ctl, right_info);
2310 info->bytes += right_info->bytes;
2311 kmem_cache_free(btrfs_free_space_cachep, right_info);
2312 merged = true;
2313 }
2314
2315 /* See try_merge_free_space() comment. */
2316 if (left_info && !left_info->bitmap &&
2317 left_info->offset + left_info->bytes == offset &&
2318 (!is_trimmed || btrfs_free_space_trimmed(left_info))) {
2319 if (update_stat)
2320 unlink_free_space(ctl, left_info);
2321 else
2322 __unlink_free_space(ctl, left_info);
2323 info->offset = left_info->offset;
2324 info->bytes += left_info->bytes;
2325 kmem_cache_free(btrfs_free_space_cachep, left_info);
2326 merged = true;
2327 }
2328
2329 return merged;
2330 }
2331
2332 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2333 struct btrfs_free_space *info,
2334 bool update_stat)
2335 {
2336 struct btrfs_free_space *bitmap;
2337 unsigned long i;
2338 unsigned long j;
2339 const u64 end = info->offset + info->bytes;
2340 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2341 u64 bytes;
2342
2343 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2344 if (!bitmap)
2345 return false;
2346
2347 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2348 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2349 if (j == i)
2350 return false;
2351 bytes = (j - i) * ctl->unit;
2352 info->bytes += bytes;
2353
2354 /* See try_merge_free_space() comment. */
2355 if (!btrfs_free_space_trimmed(bitmap))
2356 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2357
2358 if (update_stat)
2359 bitmap_clear_bits(ctl, bitmap, end, bytes);
2360 else
2361 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2362
2363 if (!bitmap->bytes)
2364 free_bitmap(ctl, bitmap);
2365
2366 return true;
2367 }
2368
2369 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2370 struct btrfs_free_space *info,
2371 bool update_stat)
2372 {
2373 struct btrfs_free_space *bitmap;
2374 u64 bitmap_offset;
2375 unsigned long i;
2376 unsigned long j;
2377 unsigned long prev_j;
2378 u64 bytes;
2379
2380 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2381 /* If we're on a boundary, try the previous logical bitmap. */
2382 if (bitmap_offset == info->offset) {
2383 if (info->offset == 0)
2384 return false;
2385 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2386 }
2387
2388 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2389 if (!bitmap)
2390 return false;
2391
2392 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2393 j = 0;
2394 prev_j = (unsigned long)-1;
2395 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2396 if (j > i)
2397 break;
2398 prev_j = j;
2399 }
2400 if (prev_j == i)
2401 return false;
2402
2403 if (prev_j == (unsigned long)-1)
2404 bytes = (i + 1) * ctl->unit;
2405 else
2406 bytes = (i - prev_j) * ctl->unit;
2407
2408 info->offset -= bytes;
2409 info->bytes += bytes;
2410
2411 /* See try_merge_free_space() comment. */
2412 if (!btrfs_free_space_trimmed(bitmap))
2413 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2414
2415 if (update_stat)
2416 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2417 else
2418 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2419
2420 if (!bitmap->bytes)
2421 free_bitmap(ctl, bitmap);
2422
2423 return true;
2424 }
2425
2426 /*
2427 * We prefer always to allocate from extent entries, both for clustered and
2428 * non-clustered allocation requests. So when attempting to add a new extent
2429 * entry, try to see if there's adjacent free space in bitmap entries, and if
2430 * there is, migrate that space from the bitmaps to the extent.
2431 * Like this we get better chances of satisfying space allocation requests
2432 * because we attempt to satisfy them based on a single cache entry, and never
2433 * on 2 or more entries - even if the entries represent a contiguous free space
2434 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2435 * ends).
2436 */
2437 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2438 struct btrfs_free_space *info,
2439 bool update_stat)
2440 {
2441 /*
2442 * Only work with disconnected entries, as we can change their offset,
2443 * and must be extent entries.
2444 */
2445 ASSERT(!info->bitmap);
2446 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2447
2448 if (ctl->total_bitmaps > 0) {
2449 bool stole_end;
2450 bool stole_front = false;
2451
2452 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2453 if (ctl->total_bitmaps > 0)
2454 stole_front = steal_from_bitmap_to_front(ctl, info,
2455 update_stat);
2456
2457 if (stole_end || stole_front)
2458 try_merge_free_space(ctl, info, update_stat);
2459 }
2460 }
2461
2462 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
2463 struct btrfs_free_space_ctl *ctl,
2464 u64 offset, u64 bytes,
2465 enum btrfs_trim_state trim_state)
2466 {
2467 struct btrfs_block_group *block_group = ctl->private;
2468 struct btrfs_free_space *info;
2469 int ret = 0;
2470 u64 filter_bytes = bytes;
2471
2472 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2473 if (!info)
2474 return -ENOMEM;
2475
2476 info->offset = offset;
2477 info->bytes = bytes;
2478 info->trim_state = trim_state;
2479 RB_CLEAR_NODE(&info->offset_index);
2480
2481 spin_lock(&ctl->tree_lock);
2482
2483 if (try_merge_free_space(ctl, info, true))
2484 goto link;
2485
2486 /*
2487 * There was no extent directly to the left or right of this new
2488 * extent then we know we're going to have to allocate a new extent, so
2489 * before we do that see if we need to drop this into a bitmap
2490 */
2491 ret = insert_into_bitmap(ctl, info);
2492 if (ret < 0) {
2493 goto out;
2494 } else if (ret) {
2495 ret = 0;
2496 goto out;
2497 }
2498 link:
2499 /*
2500 * Only steal free space from adjacent bitmaps if we're sure we're not
2501 * going to add the new free space to existing bitmap entries - because
2502 * that would mean unnecessary work that would be reverted. Therefore
2503 * attempt to steal space from bitmaps if we're adding an extent entry.
2504 */
2505 steal_from_bitmap(ctl, info, true);
2506
2507 filter_bytes = max(filter_bytes, info->bytes);
2508
2509 ret = link_free_space(ctl, info);
2510 if (ret)
2511 kmem_cache_free(btrfs_free_space_cachep, info);
2512 out:
2513 btrfs_discard_update_discardable(block_group, ctl);
2514 spin_unlock(&ctl->tree_lock);
2515
2516 if (ret) {
2517 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2518 ASSERT(ret != -EEXIST);
2519 }
2520
2521 if (trim_state != BTRFS_TRIM_STATE_TRIMMED) {
2522 btrfs_discard_check_filter(block_group, filter_bytes);
2523 btrfs_discard_queue_work(&fs_info->discard_ctl, block_group);
2524 }
2525
2526 return ret;
2527 }
2528
2529 int btrfs_add_free_space(struct btrfs_block_group *block_group,
2530 u64 bytenr, u64 size)
2531 {
2532 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2533
2534 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
2535 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2536
2537 return __btrfs_add_free_space(block_group->fs_info,
2538 block_group->free_space_ctl,
2539 bytenr, size, trim_state);
2540 }
2541
2542 /*
2543 * This is a subtle distinction because when adding free space back in general,
2544 * we want it to be added as untrimmed for async. But in the case where we add
2545 * it on loading of a block group, we want to consider it trimmed.
2546 */
2547 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
2548 u64 bytenr, u64 size)
2549 {
2550 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2551
2552 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) ||
2553 btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
2554 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2555
2556 return __btrfs_add_free_space(block_group->fs_info,
2557 block_group->free_space_ctl,
2558 bytenr, size, trim_state);
2559 }
2560
2561 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
2562 u64 offset, u64 bytes)
2563 {
2564 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2565 struct btrfs_free_space *info;
2566 int ret;
2567 bool re_search = false;
2568
2569 spin_lock(&ctl->tree_lock);
2570
2571 again:
2572 ret = 0;
2573 if (!bytes)
2574 goto out_lock;
2575
2576 info = tree_search_offset(ctl, offset, 0, 0);
2577 if (!info) {
2578 /*
2579 * oops didn't find an extent that matched the space we wanted
2580 * to remove, look for a bitmap instead
2581 */
2582 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2583 1, 0);
2584 if (!info) {
2585 /*
2586 * If we found a partial bit of our free space in a
2587 * bitmap but then couldn't find the other part this may
2588 * be a problem, so WARN about it.
2589 */
2590 WARN_ON(re_search);
2591 goto out_lock;
2592 }
2593 }
2594
2595 re_search = false;
2596 if (!info->bitmap) {
2597 unlink_free_space(ctl, info);
2598 if (offset == info->offset) {
2599 u64 to_free = min(bytes, info->bytes);
2600
2601 info->bytes -= to_free;
2602 info->offset += to_free;
2603 if (info->bytes) {
2604 ret = link_free_space(ctl, info);
2605 WARN_ON(ret);
2606 } else {
2607 kmem_cache_free(btrfs_free_space_cachep, info);
2608 }
2609
2610 offset += to_free;
2611 bytes -= to_free;
2612 goto again;
2613 } else {
2614 u64 old_end = info->bytes + info->offset;
2615
2616 info->bytes = offset - info->offset;
2617 ret = link_free_space(ctl, info);
2618 WARN_ON(ret);
2619 if (ret)
2620 goto out_lock;
2621
2622 /* Not enough bytes in this entry to satisfy us */
2623 if (old_end < offset + bytes) {
2624 bytes -= old_end - offset;
2625 offset = old_end;
2626 goto again;
2627 } else if (old_end == offset + bytes) {
2628 /* all done */
2629 goto out_lock;
2630 }
2631 spin_unlock(&ctl->tree_lock);
2632
2633 ret = __btrfs_add_free_space(block_group->fs_info, ctl,
2634 offset + bytes,
2635 old_end - (offset + bytes),
2636 info->trim_state);
2637 WARN_ON(ret);
2638 goto out;
2639 }
2640 }
2641
2642 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2643 if (ret == -EAGAIN) {
2644 re_search = true;
2645 goto again;
2646 }
2647 out_lock:
2648 btrfs_discard_update_discardable(block_group, ctl);
2649 spin_unlock(&ctl->tree_lock);
2650 out:
2651 return ret;
2652 }
2653
2654 void btrfs_dump_free_space(struct btrfs_block_group *block_group,
2655 u64 bytes)
2656 {
2657 struct btrfs_fs_info *fs_info = block_group->fs_info;
2658 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2659 struct btrfs_free_space *info;
2660 struct rb_node *n;
2661 int count = 0;
2662
2663 spin_lock(&ctl->tree_lock);
2664 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2665 info = rb_entry(n, struct btrfs_free_space, offset_index);
2666 if (info->bytes >= bytes && !block_group->ro)
2667 count++;
2668 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2669 info->offset, info->bytes,
2670 (info->bitmap) ? "yes" : "no");
2671 }
2672 spin_unlock(&ctl->tree_lock);
2673 btrfs_info(fs_info, "block group has cluster?: %s",
2674 list_empty(&block_group->cluster_list) ? "no" : "yes");
2675 btrfs_info(fs_info,
2676 "%d blocks of free space at or bigger than bytes is", count);
2677 }
2678
2679 void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group)
2680 {
2681 struct btrfs_fs_info *fs_info = block_group->fs_info;
2682 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2683
2684 spin_lock_init(&ctl->tree_lock);
2685 ctl->unit = fs_info->sectorsize;
2686 ctl->start = block_group->start;
2687 ctl->private = block_group;
2688 ctl->op = &free_space_op;
2689 INIT_LIST_HEAD(&ctl->trimming_ranges);
2690 mutex_init(&ctl->cache_writeout_mutex);
2691
2692 /*
2693 * we only want to have 32k of ram per block group for keeping
2694 * track of free space, and if we pass 1/2 of that we want to
2695 * start converting things over to using bitmaps
2696 */
2697 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2698 }
2699
2700 /*
2701 * for a given cluster, put all of its extents back into the free
2702 * space cache. If the block group passed doesn't match the block group
2703 * pointed to by the cluster, someone else raced in and freed the
2704 * cluster already. In that case, we just return without changing anything
2705 */
2706 static int
2707 __btrfs_return_cluster_to_free_space(
2708 struct btrfs_block_group *block_group,
2709 struct btrfs_free_cluster *cluster)
2710 {
2711 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2712 struct btrfs_free_space *entry;
2713 struct rb_node *node;
2714
2715 spin_lock(&cluster->lock);
2716 if (cluster->block_group != block_group)
2717 goto out;
2718
2719 cluster->block_group = NULL;
2720 cluster->window_start = 0;
2721 list_del_init(&cluster->block_group_list);
2722
2723 node = rb_first(&cluster->root);
2724 while (node) {
2725 bool bitmap;
2726
2727 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2728 node = rb_next(&entry->offset_index);
2729 rb_erase(&entry->offset_index, &cluster->root);
2730 RB_CLEAR_NODE(&entry->offset_index);
2731
2732 bitmap = (entry->bitmap != NULL);
2733 if (!bitmap) {
2734 /* Merging treats extents as if they were new */
2735 if (!btrfs_free_space_trimmed(entry)) {
2736 ctl->discardable_extents[BTRFS_STAT_CURR]--;
2737 ctl->discardable_bytes[BTRFS_STAT_CURR] -=
2738 entry->bytes;
2739 }
2740
2741 try_merge_free_space(ctl, entry, false);
2742 steal_from_bitmap(ctl, entry, false);
2743
2744 /* As we insert directly, update these statistics */
2745 if (!btrfs_free_space_trimmed(entry)) {
2746 ctl->discardable_extents[BTRFS_STAT_CURR]++;
2747 ctl->discardable_bytes[BTRFS_STAT_CURR] +=
2748 entry->bytes;
2749 }
2750 }
2751 tree_insert_offset(&ctl->free_space_offset,
2752 entry->offset, &entry->offset_index, bitmap);
2753 }
2754 cluster->root = RB_ROOT;
2755
2756 out:
2757 spin_unlock(&cluster->lock);
2758 btrfs_put_block_group(block_group);
2759 return 0;
2760 }
2761
2762 static void __btrfs_remove_free_space_cache_locked(
2763 struct btrfs_free_space_ctl *ctl)
2764 {
2765 struct btrfs_free_space *info;
2766 struct rb_node *node;
2767
2768 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2769 info = rb_entry(node, struct btrfs_free_space, offset_index);
2770 if (!info->bitmap) {
2771 unlink_free_space(ctl, info);
2772 kmem_cache_free(btrfs_free_space_cachep, info);
2773 } else {
2774 free_bitmap(ctl, info);
2775 }
2776
2777 cond_resched_lock(&ctl->tree_lock);
2778 }
2779 }
2780
2781 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2782 {
2783 spin_lock(&ctl->tree_lock);
2784 __btrfs_remove_free_space_cache_locked(ctl);
2785 if (ctl->private)
2786 btrfs_discard_update_discardable(ctl->private, ctl);
2787 spin_unlock(&ctl->tree_lock);
2788 }
2789
2790 void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group)
2791 {
2792 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2793 struct btrfs_free_cluster *cluster;
2794 struct list_head *head;
2795
2796 spin_lock(&ctl->tree_lock);
2797 while ((head = block_group->cluster_list.next) !=
2798 &block_group->cluster_list) {
2799 cluster = list_entry(head, struct btrfs_free_cluster,
2800 block_group_list);
2801
2802 WARN_ON(cluster->block_group != block_group);
2803 __btrfs_return_cluster_to_free_space(block_group, cluster);
2804
2805 cond_resched_lock(&ctl->tree_lock);
2806 }
2807 __btrfs_remove_free_space_cache_locked(ctl);
2808 btrfs_discard_update_discardable(block_group, ctl);
2809 spin_unlock(&ctl->tree_lock);
2810
2811 }
2812
2813 /**
2814 * btrfs_is_free_space_trimmed - see if everything is trimmed
2815 * @block_group: block_group of interest
2816 *
2817 * Walk @block_group's free space rb_tree to determine if everything is trimmed.
2818 */
2819 bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group)
2820 {
2821 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2822 struct btrfs_free_space *info;
2823 struct rb_node *node;
2824 bool ret = true;
2825
2826 spin_lock(&ctl->tree_lock);
2827 node = rb_first(&ctl->free_space_offset);
2828
2829 while (node) {
2830 info = rb_entry(node, struct btrfs_free_space, offset_index);
2831
2832 if (!btrfs_free_space_trimmed(info)) {
2833 ret = false;
2834 break;
2835 }
2836
2837 node = rb_next(node);
2838 }
2839
2840 spin_unlock(&ctl->tree_lock);
2841 return ret;
2842 }
2843
2844 u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
2845 u64 offset, u64 bytes, u64 empty_size,
2846 u64 *max_extent_size)
2847 {
2848 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2849 struct btrfs_discard_ctl *discard_ctl =
2850 &block_group->fs_info->discard_ctl;
2851 struct btrfs_free_space *entry = NULL;
2852 u64 bytes_search = bytes + empty_size;
2853 u64 ret = 0;
2854 u64 align_gap = 0;
2855 u64 align_gap_len = 0;
2856 enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2857
2858 spin_lock(&ctl->tree_lock);
2859 entry = find_free_space(ctl, &offset, &bytes_search,
2860 block_group->full_stripe_len, max_extent_size);
2861 if (!entry)
2862 goto out;
2863
2864 ret = offset;
2865 if (entry->bitmap) {
2866 bitmap_clear_bits(ctl, entry, offset, bytes);
2867
2868 if (!btrfs_free_space_trimmed(entry))
2869 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
2870
2871 if (!entry->bytes)
2872 free_bitmap(ctl, entry);
2873 } else {
2874 unlink_free_space(ctl, entry);
2875 align_gap_len = offset - entry->offset;
2876 align_gap = entry->offset;
2877 align_gap_trim_state = entry->trim_state;
2878
2879 if (!btrfs_free_space_trimmed(entry))
2880 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
2881
2882 entry->offset = offset + bytes;
2883 WARN_ON(entry->bytes < bytes + align_gap_len);
2884
2885 entry->bytes -= bytes + align_gap_len;
2886 if (!entry->bytes)
2887 kmem_cache_free(btrfs_free_space_cachep, entry);
2888 else
2889 link_free_space(ctl, entry);
2890 }
2891 out:
2892 btrfs_discard_update_discardable(block_group, ctl);
2893 spin_unlock(&ctl->tree_lock);
2894
2895 if (align_gap_len)
2896 __btrfs_add_free_space(block_group->fs_info, ctl,
2897 align_gap, align_gap_len,
2898 align_gap_trim_state);
2899 return ret;
2900 }
2901
2902 /*
2903 * given a cluster, put all of its extents back into the free space
2904 * cache. If a block group is passed, this function will only free
2905 * a cluster that belongs to the passed block group.
2906 *
2907 * Otherwise, it'll get a reference on the block group pointed to by the
2908 * cluster and remove the cluster from it.
2909 */
2910 int btrfs_return_cluster_to_free_space(
2911 struct btrfs_block_group *block_group,
2912 struct btrfs_free_cluster *cluster)
2913 {
2914 struct btrfs_free_space_ctl *ctl;
2915 int ret;
2916
2917 /* first, get a safe pointer to the block group */
2918 spin_lock(&cluster->lock);
2919 if (!block_group) {
2920 block_group = cluster->block_group;
2921 if (!block_group) {
2922 spin_unlock(&cluster->lock);
2923 return 0;
2924 }
2925 } else if (cluster->block_group != block_group) {
2926 /* someone else has already freed it don't redo their work */
2927 spin_unlock(&cluster->lock);
2928 return 0;
2929 }
2930 atomic_inc(&block_group->count);
2931 spin_unlock(&cluster->lock);
2932
2933 ctl = block_group->free_space_ctl;
2934
2935 /* now return any extents the cluster had on it */
2936 spin_lock(&ctl->tree_lock);
2937 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2938 spin_unlock(&ctl->tree_lock);
2939
2940 btrfs_discard_queue_work(&block_group->fs_info->discard_ctl, block_group);
2941
2942 /* finally drop our ref */
2943 btrfs_put_block_group(block_group);
2944 return ret;
2945 }
2946
2947 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group *block_group,
2948 struct btrfs_free_cluster *cluster,
2949 struct btrfs_free_space *entry,
2950 u64 bytes, u64 min_start,
2951 u64 *max_extent_size)
2952 {
2953 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2954 int err;
2955 u64 search_start = cluster->window_start;
2956 u64 search_bytes = bytes;
2957 u64 ret = 0;
2958
2959 search_start = min_start;
2960 search_bytes = bytes;
2961
2962 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2963 if (err) {
2964 *max_extent_size = max(get_max_extent_size(entry),
2965 *max_extent_size);
2966 return 0;
2967 }
2968
2969 ret = search_start;
2970 __bitmap_clear_bits(ctl, entry, ret, bytes);
2971
2972 return ret;
2973 }
2974
2975 /*
2976 * given a cluster, try to allocate 'bytes' from it, returns 0
2977 * if it couldn't find anything suitably large, or a logical disk offset
2978 * if things worked out
2979 */
2980 u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
2981 struct btrfs_free_cluster *cluster, u64 bytes,
2982 u64 min_start, u64 *max_extent_size)
2983 {
2984 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2985 struct btrfs_discard_ctl *discard_ctl =
2986 &block_group->fs_info->discard_ctl;
2987 struct btrfs_free_space *entry = NULL;
2988 struct rb_node *node;
2989 u64 ret = 0;
2990
2991 spin_lock(&cluster->lock);
2992 if (bytes > cluster->max_size)
2993 goto out;
2994
2995 if (cluster->block_group != block_group)
2996 goto out;
2997
2998 node = rb_first(&cluster->root);
2999 if (!node)
3000 goto out;
3001
3002 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3003 while (1) {
3004 if (entry->bytes < bytes)
3005 *max_extent_size = max(get_max_extent_size(entry),
3006 *max_extent_size);
3007
3008 if (entry->bytes < bytes ||
3009 (!entry->bitmap && entry->offset < min_start)) {
3010 node = rb_next(&entry->offset_index);
3011 if (!node)
3012 break;
3013 entry = rb_entry(node, struct btrfs_free_space,
3014 offset_index);
3015 continue;
3016 }
3017
3018 if (entry->bitmap) {
3019 ret = btrfs_alloc_from_bitmap(block_group,
3020 cluster, entry, bytes,
3021 cluster->window_start,
3022 max_extent_size);
3023 if (ret == 0) {
3024 node = rb_next(&entry->offset_index);
3025 if (!node)
3026 break;
3027 entry = rb_entry(node, struct btrfs_free_space,
3028 offset_index);
3029 continue;
3030 }
3031 cluster->window_start += bytes;
3032 } else {
3033 ret = entry->offset;
3034
3035 entry->offset += bytes;
3036 entry->bytes -= bytes;
3037 }
3038
3039 if (entry->bytes == 0)
3040 rb_erase(&entry->offset_index, &cluster->root);
3041 break;
3042 }
3043 out:
3044 spin_unlock(&cluster->lock);
3045
3046 if (!ret)
3047 return 0;
3048
3049 spin_lock(&ctl->tree_lock);
3050
3051 if (!btrfs_free_space_trimmed(entry))
3052 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3053
3054 ctl->free_space -= bytes;
3055 if (!entry->bitmap && !btrfs_free_space_trimmed(entry))
3056 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
3057 if (entry->bytes == 0) {
3058 ctl->free_extents--;
3059 if (entry->bitmap) {
3060 kmem_cache_free(btrfs_free_space_bitmap_cachep,
3061 entry->bitmap);
3062 ctl->total_bitmaps--;
3063 ctl->op->recalc_thresholds(ctl);
3064 } else if (!btrfs_free_space_trimmed(entry)) {
3065 ctl->discardable_extents[BTRFS_STAT_CURR]--;
3066 }
3067 kmem_cache_free(btrfs_free_space_cachep, entry);
3068 }
3069
3070 spin_unlock(&ctl->tree_lock);
3071
3072 return ret;
3073 }
3074
3075 static int btrfs_bitmap_cluster(struct btrfs_block_group *block_group,
3076 struct btrfs_free_space *entry,
3077 struct btrfs_free_cluster *cluster,
3078 u64 offset, u64 bytes,
3079 u64 cont1_bytes, u64 min_bytes)
3080 {
3081 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3082 unsigned long next_zero;
3083 unsigned long i;
3084 unsigned long want_bits;
3085 unsigned long min_bits;
3086 unsigned long found_bits;
3087 unsigned long max_bits = 0;
3088 unsigned long start = 0;
3089 unsigned long total_found = 0;
3090 int ret;
3091
3092 i = offset_to_bit(entry->offset, ctl->unit,
3093 max_t(u64, offset, entry->offset));
3094 want_bits = bytes_to_bits(bytes, ctl->unit);
3095 min_bits = bytes_to_bits(min_bytes, ctl->unit);
3096
3097 /*
3098 * Don't bother looking for a cluster in this bitmap if it's heavily
3099 * fragmented.
3100 */
3101 if (entry->max_extent_size &&
3102 entry->max_extent_size < cont1_bytes)
3103 return -ENOSPC;
3104 again:
3105 found_bits = 0;
3106 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
3107 next_zero = find_next_zero_bit(entry->bitmap,
3108 BITS_PER_BITMAP, i);
3109 if (next_zero - i >= min_bits) {
3110 found_bits = next_zero - i;
3111 if (found_bits > max_bits)
3112 max_bits = found_bits;
3113 break;
3114 }
3115 if (next_zero - i > max_bits)
3116 max_bits = next_zero - i;
3117 i = next_zero;
3118 }
3119
3120 if (!found_bits) {
3121 entry->max_extent_size = (u64)max_bits * ctl->unit;
3122 return -ENOSPC;
3123 }
3124
3125 if (!total_found) {
3126 start = i;
3127 cluster->max_size = 0;
3128 }
3129
3130 total_found += found_bits;
3131
3132 if (cluster->max_size < found_bits * ctl->unit)
3133 cluster->max_size = found_bits * ctl->unit;
3134
3135 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
3136 i = next_zero + 1;
3137 goto again;
3138 }
3139
3140 cluster->window_start = start * ctl->unit + entry->offset;
3141 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3142 ret = tree_insert_offset(&cluster->root, entry->offset,
3143 &entry->offset_index, 1);
3144 ASSERT(!ret); /* -EEXIST; Logic error */
3145
3146 trace_btrfs_setup_cluster(block_group, cluster,
3147 total_found * ctl->unit, 1);
3148 return 0;
3149 }
3150
3151 /*
3152 * This searches the block group for just extents to fill the cluster with.
3153 * Try to find a cluster with at least bytes total bytes, at least one
3154 * extent of cont1_bytes, and other clusters of at least min_bytes.
3155 */
3156 static noinline int
3157 setup_cluster_no_bitmap(struct btrfs_block_group *block_group,
3158 struct btrfs_free_cluster *cluster,
3159 struct list_head *bitmaps, u64 offset, u64 bytes,
3160 u64 cont1_bytes, u64 min_bytes)
3161 {
3162 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3163 struct btrfs_free_space *first = NULL;
3164 struct btrfs_free_space *entry = NULL;
3165 struct btrfs_free_space *last;
3166 struct rb_node *node;
3167 u64 window_free;
3168 u64 max_extent;
3169 u64 total_size = 0;
3170
3171 entry = tree_search_offset(ctl, offset, 0, 1);
3172 if (!entry)
3173 return -ENOSPC;
3174
3175 /*
3176 * We don't want bitmaps, so just move along until we find a normal
3177 * extent entry.
3178 */
3179 while (entry->bitmap || entry->bytes < min_bytes) {
3180 if (entry->bitmap && list_empty(&entry->list))
3181 list_add_tail(&entry->list, bitmaps);
3182 node = rb_next(&entry->offset_index);
3183 if (!node)
3184 return -ENOSPC;
3185 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3186 }
3187
3188 window_free = entry->bytes;
3189 max_extent = entry->bytes;
3190 first = entry;
3191 last = entry;
3192
3193 for (node = rb_next(&entry->offset_index); node;
3194 node = rb_next(&entry->offset_index)) {
3195 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3196
3197 if (entry->bitmap) {
3198 if (list_empty(&entry->list))
3199 list_add_tail(&entry->list, bitmaps);
3200 continue;
3201 }
3202
3203 if (entry->bytes < min_bytes)
3204 continue;
3205
3206 last = entry;
3207 window_free += entry->bytes;
3208 if (entry->bytes > max_extent)
3209 max_extent = entry->bytes;
3210 }
3211
3212 if (window_free < bytes || max_extent < cont1_bytes)
3213 return -ENOSPC;
3214
3215 cluster->window_start = first->offset;
3216
3217 node = &first->offset_index;
3218
3219 /*
3220 * now we've found our entries, pull them out of the free space
3221 * cache and put them into the cluster rbtree
3222 */
3223 do {
3224 int ret;
3225
3226 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3227 node = rb_next(&entry->offset_index);
3228 if (entry->bitmap || entry->bytes < min_bytes)
3229 continue;
3230
3231 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3232 ret = tree_insert_offset(&cluster->root, entry->offset,
3233 &entry->offset_index, 0);
3234 total_size += entry->bytes;
3235 ASSERT(!ret); /* -EEXIST; Logic error */
3236 } while (node && entry != last);
3237
3238 cluster->max_size = max_extent;
3239 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
3240 return 0;
3241 }
3242
3243 /*
3244 * This specifically looks for bitmaps that may work in the cluster, we assume
3245 * that we have already failed to find extents that will work.
3246 */
3247 static noinline int
3248 setup_cluster_bitmap(struct btrfs_block_group *block_group,
3249 struct btrfs_free_cluster *cluster,
3250 struct list_head *bitmaps, u64 offset, u64 bytes,
3251 u64 cont1_bytes, u64 min_bytes)
3252 {
3253 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3254 struct btrfs_free_space *entry = NULL;
3255 int ret = -ENOSPC;
3256 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
3257
3258 if (ctl->total_bitmaps == 0)
3259 return -ENOSPC;
3260
3261 /*
3262 * The bitmap that covers offset won't be in the list unless offset
3263 * is just its start offset.
3264 */
3265 if (!list_empty(bitmaps))
3266 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
3267
3268 if (!entry || entry->offset != bitmap_offset) {
3269 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
3270 if (entry && list_empty(&entry->list))
3271 list_add(&entry->list, bitmaps);
3272 }
3273
3274 list_for_each_entry(entry, bitmaps, list) {
3275 if (entry->bytes < bytes)
3276 continue;
3277 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3278 bytes, cont1_bytes, min_bytes);
3279 if (!ret)
3280 return 0;
3281 }
3282
3283 /*
3284 * The bitmaps list has all the bitmaps that record free space
3285 * starting after offset, so no more search is required.
3286 */
3287 return -ENOSPC;
3288 }
3289
3290 /*
3291 * here we try to find a cluster of blocks in a block group. The goal
3292 * is to find at least bytes+empty_size.
3293 * We might not find them all in one contiguous area.
3294 *
3295 * returns zero and sets up cluster if things worked out, otherwise
3296 * it returns -enospc
3297 */
3298 int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
3299 struct btrfs_free_cluster *cluster,
3300 u64 offset, u64 bytes, u64 empty_size)
3301 {
3302 struct btrfs_fs_info *fs_info = block_group->fs_info;
3303 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3304 struct btrfs_free_space *entry, *tmp;
3305 LIST_HEAD(bitmaps);
3306 u64 min_bytes;
3307 u64 cont1_bytes;
3308 int ret;
3309
3310 /*
3311 * Choose the minimum extent size we'll require for this
3312 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3313 * For metadata, allow allocates with smaller extents. For
3314 * data, keep it dense.
3315 */
3316 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3317 cont1_bytes = min_bytes = bytes + empty_size;
3318 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3319 cont1_bytes = bytes;
3320 min_bytes = fs_info->sectorsize;
3321 } else {
3322 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3323 min_bytes = fs_info->sectorsize;
3324 }
3325
3326 spin_lock(&ctl->tree_lock);
3327
3328 /*
3329 * If we know we don't have enough space to make a cluster don't even
3330 * bother doing all the work to try and find one.
3331 */
3332 if (ctl->free_space < bytes) {
3333 spin_unlock(&ctl->tree_lock);
3334 return -ENOSPC;
3335 }
3336
3337 spin_lock(&cluster->lock);
3338
3339 /* someone already found a cluster, hooray */
3340 if (cluster->block_group) {
3341 ret = 0;
3342 goto out;
3343 }
3344
3345 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3346 min_bytes);
3347
3348 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3349 bytes + empty_size,
3350 cont1_bytes, min_bytes);
3351 if (ret)
3352 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3353 offset, bytes + empty_size,
3354 cont1_bytes, min_bytes);
3355
3356 /* Clear our temporary list */
3357 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3358 list_del_init(&entry->list);
3359
3360 if (!ret) {
3361 atomic_inc(&block_group->count);
3362 list_add_tail(&cluster->block_group_list,
3363 &block_group->cluster_list);
3364 cluster->block_group = block_group;
3365 } else {
3366 trace_btrfs_failed_cluster_setup(block_group);
3367 }
3368 out:
3369 spin_unlock(&cluster->lock);
3370 spin_unlock(&ctl->tree_lock);
3371
3372 return ret;
3373 }
3374
3375 /*
3376 * simple code to zero out a cluster
3377 */
3378 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3379 {
3380 spin_lock_init(&cluster->lock);
3381 spin_lock_init(&cluster->refill_lock);
3382 cluster->root = RB_ROOT;
3383 cluster->max_size = 0;
3384 cluster->fragmented = false;
3385 INIT_LIST_HEAD(&cluster->block_group_list);
3386 cluster->block_group = NULL;
3387 }
3388
3389 static int do_trimming(struct btrfs_block_group *block_group,
3390 u64 *total_trimmed, u64 start, u64 bytes,
3391 u64 reserved_start, u64 reserved_bytes,
3392 enum btrfs_trim_state reserved_trim_state,
3393 struct btrfs_trim_range *trim_entry)
3394 {
3395 struct btrfs_space_info *space_info = block_group->space_info;
3396 struct btrfs_fs_info *fs_info = block_group->fs_info;
3397 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3398 int ret;
3399 int update = 0;
3400 const u64 end = start + bytes;
3401 const u64 reserved_end = reserved_start + reserved_bytes;
3402 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3403 u64 trimmed = 0;
3404
3405 spin_lock(&space_info->lock);
3406 spin_lock(&block_group->lock);
3407 if (!block_group->ro) {
3408 block_group->reserved += reserved_bytes;
3409 space_info->bytes_reserved += reserved_bytes;
3410 update = 1;
3411 }
3412 spin_unlock(&block_group->lock);
3413 spin_unlock(&space_info->lock);
3414
3415 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3416 if (!ret) {
3417 *total_trimmed += trimmed;
3418 trim_state = BTRFS_TRIM_STATE_TRIMMED;
3419 }
3420
3421 mutex_lock(&ctl->cache_writeout_mutex);
3422 if (reserved_start < start)
3423 __btrfs_add_free_space(fs_info, ctl, reserved_start,
3424 start - reserved_start,
3425 reserved_trim_state);
3426 if (start + bytes < reserved_start + reserved_bytes)
3427 __btrfs_add_free_space(fs_info, ctl, end, reserved_end - end,
3428 reserved_trim_state);
3429 __btrfs_add_free_space(fs_info, ctl, start, bytes, trim_state);
3430 list_del(&trim_entry->list);
3431 mutex_unlock(&ctl->cache_writeout_mutex);
3432
3433 if (update) {
3434 spin_lock(&space_info->lock);
3435 spin_lock(&block_group->lock);
3436 if (block_group->ro)
3437 space_info->bytes_readonly += reserved_bytes;
3438 block_group->reserved -= reserved_bytes;
3439 space_info->bytes_reserved -= reserved_bytes;
3440 spin_unlock(&block_group->lock);
3441 spin_unlock(&space_info->lock);
3442 }
3443
3444 return ret;
3445 }
3446
3447 /*
3448 * If @async is set, then we will trim 1 region and return.
3449 */
3450 static int trim_no_bitmap(struct btrfs_block_group *block_group,
3451 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3452 bool async)
3453 {
3454 struct btrfs_discard_ctl *discard_ctl =
3455 &block_group->fs_info->discard_ctl;
3456 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3457 struct btrfs_free_space *entry;
3458 struct rb_node *node;
3459 int ret = 0;
3460 u64 extent_start;
3461 u64 extent_bytes;
3462 enum btrfs_trim_state extent_trim_state;
3463 u64 bytes;
3464 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3465
3466 while (start < end) {
3467 struct btrfs_trim_range trim_entry;
3468
3469 mutex_lock(&ctl->cache_writeout_mutex);
3470 spin_lock(&ctl->tree_lock);
3471
3472 if (ctl->free_space < minlen)
3473 goto out_unlock;
3474
3475 entry = tree_search_offset(ctl, start, 0, 1);
3476 if (!entry)
3477 goto out_unlock;
3478
3479 /* Skip bitmaps and if async, already trimmed entries */
3480 while (entry->bitmap ||
3481 (async && btrfs_free_space_trimmed(entry))) {
3482 node = rb_next(&entry->offset_index);
3483 if (!node)
3484 goto out_unlock;
3485 entry = rb_entry(node, struct btrfs_free_space,
3486 offset_index);
3487 }
3488
3489 if (entry->offset >= end)
3490 goto out_unlock;
3491
3492 extent_start = entry->offset;
3493 extent_bytes = entry->bytes;
3494 extent_trim_state = entry->trim_state;
3495 if (async) {
3496 start = entry->offset;
3497 bytes = entry->bytes;
3498 if (bytes < minlen) {
3499 spin_unlock(&ctl->tree_lock);
3500 mutex_unlock(&ctl->cache_writeout_mutex);
3501 goto next;
3502 }
3503 unlink_free_space(ctl, entry);
3504 /*
3505 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3506 * If X < BTRFS_ASYNC_DISCARD_MIN_FILTER, we won't trim
3507 * X when we come back around. So trim it now.
3508 */
3509 if (max_discard_size &&
3510 bytes >= (max_discard_size +
3511 BTRFS_ASYNC_DISCARD_MIN_FILTER)) {
3512 bytes = max_discard_size;
3513 extent_bytes = max_discard_size;
3514 entry->offset += max_discard_size;
3515 entry->bytes -= max_discard_size;
3516 link_free_space(ctl, entry);
3517 } else {
3518 kmem_cache_free(btrfs_free_space_cachep, entry);
3519 }
3520 } else {
3521 start = max(start, extent_start);
3522 bytes = min(extent_start + extent_bytes, end) - start;
3523 if (bytes < minlen) {
3524 spin_unlock(&ctl->tree_lock);
3525 mutex_unlock(&ctl->cache_writeout_mutex);
3526 goto next;
3527 }
3528
3529 unlink_free_space(ctl, entry);
3530 kmem_cache_free(btrfs_free_space_cachep, entry);
3531 }
3532
3533 spin_unlock(&ctl->tree_lock);
3534 trim_entry.start = extent_start;
3535 trim_entry.bytes = extent_bytes;
3536 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3537 mutex_unlock(&ctl->cache_writeout_mutex);
3538
3539 ret = do_trimming(block_group, total_trimmed, start, bytes,
3540 extent_start, extent_bytes, extent_trim_state,
3541 &trim_entry);
3542 if (ret) {
3543 block_group->discard_cursor = start + bytes;
3544 break;
3545 }
3546 next:
3547 start += bytes;
3548 block_group->discard_cursor = start;
3549 if (async && *total_trimmed)
3550 break;
3551
3552 if (fatal_signal_pending(current)) {
3553 ret = -ERESTARTSYS;
3554 break;
3555 }
3556
3557 cond_resched();
3558 }
3559
3560 return ret;
3561
3562 out_unlock:
3563 block_group->discard_cursor = btrfs_block_group_end(block_group);
3564 spin_unlock(&ctl->tree_lock);
3565 mutex_unlock(&ctl->cache_writeout_mutex);
3566
3567 return ret;
3568 }
3569
3570 /*
3571 * If we break out of trimming a bitmap prematurely, we should reset the
3572 * trimming bit. In a rather contrieved case, it's possible to race here so
3573 * reset the state to BTRFS_TRIM_STATE_UNTRIMMED.
3574 *
3575 * start = start of bitmap
3576 * end = near end of bitmap
3577 *
3578 * Thread 1: Thread 2:
3579 * trim_bitmaps(start)
3580 * trim_bitmaps(end)
3581 * end_trimming_bitmap()
3582 * reset_trimming_bitmap()
3583 */
3584 static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset)
3585 {
3586 struct btrfs_free_space *entry;
3587
3588 spin_lock(&ctl->tree_lock);
3589 entry = tree_search_offset(ctl, offset, 1, 0);
3590 if (entry) {
3591 if (btrfs_free_space_trimmed(entry)) {
3592 ctl->discardable_extents[BTRFS_STAT_CURR] +=
3593 entry->bitmap_extents;
3594 ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes;
3595 }
3596 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3597 }
3598
3599 spin_unlock(&ctl->tree_lock);
3600 }
3601
3602 static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl,
3603 struct btrfs_free_space *entry)
3604 {
3605 if (btrfs_free_space_trimming_bitmap(entry)) {
3606 entry->trim_state = BTRFS_TRIM_STATE_TRIMMED;
3607 ctl->discardable_extents[BTRFS_STAT_CURR] -=
3608 entry->bitmap_extents;
3609 ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes;
3610 }
3611 }
3612
3613 /*
3614 * If @async is set, then we will trim 1 region and return.
3615 */
3616 static int trim_bitmaps(struct btrfs_block_group *block_group,
3617 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3618 u64 maxlen, bool async)
3619 {
3620 struct btrfs_discard_ctl *discard_ctl =
3621 &block_group->fs_info->discard_ctl;
3622 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3623 struct btrfs_free_space *entry;
3624 int ret = 0;
3625 int ret2;
3626 u64 bytes;
3627 u64 offset = offset_to_bitmap(ctl, start);
3628 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3629
3630 while (offset < end) {
3631 bool next_bitmap = false;
3632 struct btrfs_trim_range trim_entry;
3633
3634 mutex_lock(&ctl->cache_writeout_mutex);
3635 spin_lock(&ctl->tree_lock);
3636
3637 if (ctl->free_space < minlen) {
3638 block_group->discard_cursor =
3639 btrfs_block_group_end(block_group);
3640 spin_unlock(&ctl->tree_lock);
3641 mutex_unlock(&ctl->cache_writeout_mutex);
3642 break;
3643 }
3644
3645 entry = tree_search_offset(ctl, offset, 1, 0);
3646 /*
3647 * Bitmaps are marked trimmed lossily now to prevent constant
3648 * discarding of the same bitmap (the reason why we are bound
3649 * by the filters). So, retrim the block group bitmaps when we
3650 * are preparing to punt to the unused_bgs list. This uses
3651 * @minlen to determine if we are in BTRFS_DISCARD_INDEX_UNUSED
3652 * which is the only discard index which sets minlen to 0.
3653 */
3654 if (!entry || (async && minlen && start == offset &&
3655 btrfs_free_space_trimmed(entry))) {
3656 spin_unlock(&ctl->tree_lock);
3657 mutex_unlock(&ctl->cache_writeout_mutex);
3658 next_bitmap = true;
3659 goto next;
3660 }
3661
3662 /*
3663 * Async discard bitmap trimming begins at by setting the start
3664 * to be key.objectid and the offset_to_bitmap() aligns to the
3665 * start of the bitmap. This lets us know we are fully
3666 * scanning the bitmap rather than only some portion of it.
3667 */
3668 if (start == offset)
3669 entry->trim_state = BTRFS_TRIM_STATE_TRIMMING;
3670
3671 bytes = minlen;
3672 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3673 if (ret2 || start >= end) {
3674 /*
3675 * We lossily consider a bitmap trimmed if we only skip
3676 * over regions <= BTRFS_ASYNC_DISCARD_MIN_FILTER.
3677 */
3678 if (ret2 && minlen <= BTRFS_ASYNC_DISCARD_MIN_FILTER)
3679 end_trimming_bitmap(ctl, entry);
3680 else
3681 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3682 spin_unlock(&ctl->tree_lock);
3683 mutex_unlock(&ctl->cache_writeout_mutex);
3684 next_bitmap = true;
3685 goto next;
3686 }
3687
3688 /*
3689 * We already trimmed a region, but are using the locking above
3690 * to reset the trim_state.
3691 */
3692 if (async && *total_trimmed) {
3693 spin_unlock(&ctl->tree_lock);
3694 mutex_unlock(&ctl->cache_writeout_mutex);
3695 goto out;
3696 }
3697
3698 bytes = min(bytes, end - start);
3699 if (bytes < minlen || (async && maxlen && bytes > maxlen)) {
3700 spin_unlock(&ctl->tree_lock);
3701 mutex_unlock(&ctl->cache_writeout_mutex);
3702 goto next;
3703 }
3704
3705 /*
3706 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3707 * If X < @minlen, we won't trim X when we come back around.
3708 * So trim it now. We differ here from trimming extents as we
3709 * don't keep individual state per bit.
3710 */
3711 if (async &&
3712 max_discard_size &&
3713 bytes > (max_discard_size + minlen))
3714 bytes = max_discard_size;
3715
3716 bitmap_clear_bits(ctl, entry, start, bytes);
3717 if (entry->bytes == 0)
3718 free_bitmap(ctl, entry);
3719
3720 spin_unlock(&ctl->tree_lock);
3721 trim_entry.start = start;
3722 trim_entry.bytes = bytes;
3723 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3724 mutex_unlock(&ctl->cache_writeout_mutex);
3725
3726 ret = do_trimming(block_group, total_trimmed, start, bytes,
3727 start, bytes, 0, &trim_entry);
3728 if (ret) {
3729 reset_trimming_bitmap(ctl, offset);
3730 block_group->discard_cursor =
3731 btrfs_block_group_end(block_group);
3732 break;
3733 }
3734 next:
3735 if (next_bitmap) {
3736 offset += BITS_PER_BITMAP * ctl->unit;
3737 start = offset;
3738 } else {
3739 start += bytes;
3740 }
3741 block_group->discard_cursor = start;
3742
3743 if (fatal_signal_pending(current)) {
3744 if (start != offset)
3745 reset_trimming_bitmap(ctl, offset);
3746 ret = -ERESTARTSYS;
3747 break;
3748 }
3749
3750 cond_resched();
3751 }
3752
3753 if (offset >= end)
3754 block_group->discard_cursor = end;
3755
3756 out:
3757 return ret;
3758 }
3759
3760 int btrfs_trim_block_group(struct btrfs_block_group *block_group,
3761 u64 *trimmed, u64 start, u64 end, u64 minlen)
3762 {
3763 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3764 int ret;
3765 u64 rem = 0;
3766
3767 *trimmed = 0;
3768
3769 spin_lock(&block_group->lock);
3770 if (block_group->removed) {
3771 spin_unlock(&block_group->lock);
3772 return 0;
3773 }
3774 btrfs_freeze_block_group(block_group);
3775 spin_unlock(&block_group->lock);
3776
3777 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, false);
3778 if (ret)
3779 goto out;
3780
3781 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, 0, false);
3782 div64_u64_rem(end, BITS_PER_BITMAP * ctl->unit, &rem);
3783 /* If we ended in the middle of a bitmap, reset the trimming flag */
3784 if (rem)
3785 reset_trimming_bitmap(ctl, offset_to_bitmap(ctl, end));
3786 out:
3787 btrfs_unfreeze_block_group(block_group);
3788 return ret;
3789 }
3790
3791 int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
3792 u64 *trimmed, u64 start, u64 end, u64 minlen,
3793 bool async)
3794 {
3795 int ret;
3796
3797 *trimmed = 0;
3798
3799 spin_lock(&block_group->lock);
3800 if (block_group->removed) {
3801 spin_unlock(&block_group->lock);
3802 return 0;
3803 }
3804 btrfs_freeze_block_group(block_group);
3805 spin_unlock(&block_group->lock);
3806
3807 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, async);
3808 btrfs_unfreeze_block_group(block_group);
3809
3810 return ret;
3811 }
3812
3813 int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
3814 u64 *trimmed, u64 start, u64 end, u64 minlen,
3815 u64 maxlen, bool async)
3816 {
3817 int ret;
3818
3819 *trimmed = 0;
3820
3821 spin_lock(&block_group->lock);
3822 if (block_group->removed) {
3823 spin_unlock(&block_group->lock);
3824 return 0;
3825 }
3826 btrfs_freeze_block_group(block_group);
3827 spin_unlock(&block_group->lock);
3828
3829 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, maxlen,
3830 async);
3831
3832 btrfs_unfreeze_block_group(block_group);
3833
3834 return ret;
3835 }
3836
3837 /*
3838 * Find the left-most item in the cache tree, and then return the
3839 * smallest inode number in the item.
3840 *
3841 * Note: the returned inode number may not be the smallest one in
3842 * the tree, if the left-most item is a bitmap.
3843 */
3844 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3845 {
3846 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3847 struct btrfs_free_space *entry = NULL;
3848 u64 ino = 0;
3849
3850 spin_lock(&ctl->tree_lock);
3851
3852 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3853 goto out;
3854
3855 entry = rb_entry(rb_first(&ctl->free_space_offset),
3856 struct btrfs_free_space, offset_index);
3857
3858 if (!entry->bitmap) {
3859 ino = entry->offset;
3860
3861 unlink_free_space(ctl, entry);
3862 entry->offset++;
3863 entry->bytes--;
3864 if (!entry->bytes)
3865 kmem_cache_free(btrfs_free_space_cachep, entry);
3866 else
3867 link_free_space(ctl, entry);
3868 } else {
3869 u64 offset = 0;
3870 u64 count = 1;
3871 int ret;
3872
3873 ret = search_bitmap(ctl, entry, &offset, &count, true);
3874 /* Logic error; Should be empty if it can't find anything */
3875 ASSERT(!ret);
3876
3877 ino = offset;
3878 bitmap_clear_bits(ctl, entry, offset, 1);
3879 if (entry->bytes == 0)
3880 free_bitmap(ctl, entry);
3881 }
3882 out:
3883 spin_unlock(&ctl->tree_lock);
3884
3885 return ino;
3886 }
3887
3888 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3889 struct btrfs_path *path)
3890 {
3891 struct inode *inode = NULL;
3892
3893 spin_lock(&root->ino_cache_lock);
3894 if (root->ino_cache_inode)
3895 inode = igrab(root->ino_cache_inode);
3896 spin_unlock(&root->ino_cache_lock);
3897 if (inode)
3898 return inode;
3899
3900 inode = __lookup_free_space_inode(root, path, 0);
3901 if (IS_ERR(inode))
3902 return inode;
3903
3904 spin_lock(&root->ino_cache_lock);
3905 if (!btrfs_fs_closing(root->fs_info))
3906 root->ino_cache_inode = igrab(inode);
3907 spin_unlock(&root->ino_cache_lock);
3908
3909 return inode;
3910 }
3911
3912 int create_free_ino_inode(struct btrfs_root *root,
3913 struct btrfs_trans_handle *trans,
3914 struct btrfs_path *path)
3915 {
3916 return __create_free_space_inode(root, trans, path,
3917 BTRFS_FREE_INO_OBJECTID, 0);
3918 }
3919
3920 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3921 {
3922 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3923 struct btrfs_path *path;
3924 struct inode *inode;
3925 int ret = 0;
3926 u64 root_gen = btrfs_root_generation(&root->root_item);
3927
3928 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3929 return 0;
3930
3931 /*
3932 * If we're unmounting then just return, since this does a search on the
3933 * normal root and not the commit root and we could deadlock.
3934 */
3935 if (btrfs_fs_closing(fs_info))
3936 return 0;
3937
3938 path = btrfs_alloc_path();
3939 if (!path)
3940 return 0;
3941
3942 inode = lookup_free_ino_inode(root, path);
3943 if (IS_ERR(inode))
3944 goto out;
3945
3946 if (root_gen != BTRFS_I(inode)->generation)
3947 goto out_put;
3948
3949 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3950
3951 if (ret < 0)
3952 btrfs_err(fs_info,
3953 "failed to load free ino cache for root %llu",
3954 root->root_key.objectid);
3955 out_put:
3956 iput(inode);
3957 out:
3958 btrfs_free_path(path);
3959 return ret;
3960 }
3961
3962 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3963 struct btrfs_trans_handle *trans,
3964 struct btrfs_path *path,
3965 struct inode *inode)
3966 {
3967 struct btrfs_fs_info *fs_info = root->fs_info;
3968 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3969 int ret;
3970 struct btrfs_io_ctl io_ctl;
3971 bool release_metadata = true;
3972
3973 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3974 return 0;
3975
3976 memset(&io_ctl, 0, sizeof(io_ctl));
3977 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
3978 if (!ret) {
3979 /*
3980 * At this point writepages() didn't error out, so our metadata
3981 * reservation is released when the writeback finishes, at
3982 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3983 * with or without an error.
3984 */
3985 release_metadata = false;
3986 ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
3987 }
3988
3989 if (ret) {
3990 if (release_metadata)
3991 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3992 inode->i_size, true);
3993 btrfs_debug(fs_info,
3994 "failed to write free ino cache for root %llu error %d",
3995 root->root_key.objectid, ret);
3996 }
3997
3998 return ret;
3999 }
4000
4001 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4002 /*
4003 * Use this if you need to make a bitmap or extent entry specifically, it
4004 * doesn't do any of the merging that add_free_space does, this acts a lot like
4005 * how the free space cache loading stuff works, so you can get really weird
4006 * configurations.
4007 */
4008 int test_add_free_space_entry(struct btrfs_block_group *cache,
4009 u64 offset, u64 bytes, bool bitmap)
4010 {
4011 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4012 struct btrfs_free_space *info = NULL, *bitmap_info;
4013 void *map = NULL;
4014 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_TRIMMED;
4015 u64 bytes_added;
4016 int ret;
4017
4018 again:
4019 if (!info) {
4020 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
4021 if (!info)
4022 return -ENOMEM;
4023 }
4024
4025 if (!bitmap) {
4026 spin_lock(&ctl->tree_lock);
4027 info->offset = offset;
4028 info->bytes = bytes;
4029 info->max_extent_size = 0;
4030 ret = link_free_space(ctl, info);
4031 spin_unlock(&ctl->tree_lock);
4032 if (ret)
4033 kmem_cache_free(btrfs_free_space_cachep, info);
4034 return ret;
4035 }
4036
4037 if (!map) {
4038 map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
4039 if (!map) {
4040 kmem_cache_free(btrfs_free_space_cachep, info);
4041 return -ENOMEM;
4042 }
4043 }
4044
4045 spin_lock(&ctl->tree_lock);
4046 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4047 1, 0);
4048 if (!bitmap_info) {
4049 info->bitmap = map;
4050 map = NULL;
4051 add_new_bitmap(ctl, info, offset);
4052 bitmap_info = info;
4053 info = NULL;
4054 }
4055
4056 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
4057 trim_state);
4058
4059 bytes -= bytes_added;
4060 offset += bytes_added;
4061 spin_unlock(&ctl->tree_lock);
4062
4063 if (bytes)
4064 goto again;
4065
4066 if (info)
4067 kmem_cache_free(btrfs_free_space_cachep, info);
4068 if (map)
4069 kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
4070 return 0;
4071 }
4072
4073 /*
4074 * Checks to see if the given range is in the free space cache. This is really
4075 * just used to check the absence of space, so if there is free space in the
4076 * range at all we will return 1.
4077 */
4078 int test_check_exists(struct btrfs_block_group *cache,
4079 u64 offset, u64 bytes)
4080 {
4081 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4082 struct btrfs_free_space *info;
4083 int ret = 0;
4084
4085 spin_lock(&ctl->tree_lock);
4086 info = tree_search_offset(ctl, offset, 0, 0);
4087 if (!info) {
4088 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4089 1, 0);
4090 if (!info)
4091 goto out;
4092 }
4093
4094 have_info:
4095 if (info->bitmap) {
4096 u64 bit_off, bit_bytes;
4097 struct rb_node *n;
4098 struct btrfs_free_space *tmp;
4099
4100 bit_off = offset;
4101 bit_bytes = ctl->unit;
4102 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
4103 if (!ret) {
4104 if (bit_off == offset) {
4105 ret = 1;
4106 goto out;
4107 } else if (bit_off > offset &&
4108 offset + bytes > bit_off) {
4109 ret = 1;
4110 goto out;
4111 }
4112 }
4113
4114 n = rb_prev(&info->offset_index);
4115 while (n) {
4116 tmp = rb_entry(n, struct btrfs_free_space,
4117 offset_index);
4118 if (tmp->offset + tmp->bytes < offset)
4119 break;
4120 if (offset + bytes < tmp->offset) {
4121 n = rb_prev(&tmp->offset_index);
4122 continue;
4123 }
4124 info = tmp;
4125 goto have_info;
4126 }
4127
4128 n = rb_next(&info->offset_index);
4129 while (n) {
4130 tmp = rb_entry(n, struct btrfs_free_space,
4131 offset_index);
4132 if (offset + bytes < tmp->offset)
4133 break;
4134 if (tmp->offset + tmp->bytes < offset) {
4135 n = rb_next(&tmp->offset_index);
4136 continue;
4137 }
4138 info = tmp;
4139 goto have_info;
4140 }
4141
4142 ret = 0;
4143 goto out;
4144 }
4145
4146 if (info->offset == offset) {
4147 ret = 1;
4148 goto out;
4149 }
4150
4151 if (offset > info->offset && offset < info->offset + info->bytes)
4152 ret = 1;
4153 out:
4154 spin_unlock(&ctl->tree_lock);
4155 return ret;
4156 }
4157 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Linux with added FPC-III support