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drm/panel: panel-himax-hx83102: support for csot-pna957qt1-1 MIPI-DSI panel
[drm/drm-misc.git] / fs / btrfs / free-space-cache.c
blobd42b6f882f57419c7ecaddd51ed096f2cb1599f4
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 <linux/string_choices.h>
15 #include "extent-tree.h"
16 #include "fs.h"
17 #include "messages.h"
18 #include "misc.h"
19 #include "free-space-cache.h"
20 #include "transaction.h"
21 #include "disk-io.h"
22 #include "extent_io.h"
23 #include "space-info.h"
24 #include "block-group.h"
25 #include "discard.h"
26 #include "subpage.h"
27 #include "inode-item.h"
28 #include "accessors.h"
29 #include "file-item.h"
30 #include "file.h"
31 #include "super.h"
32
33 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
34 #define MAX_CACHE_BYTES_PER_GIG SZ_64K
35 #define FORCE_EXTENT_THRESHOLD SZ_1M
36
37 static struct kmem_cache *btrfs_free_space_cachep;
38 static struct kmem_cache *btrfs_free_space_bitmap_cachep;
39
40 struct btrfs_trim_range {
41 u64 start;
42 u64 bytes;
43 struct list_head list;
44 };
45
46 static int link_free_space(struct btrfs_free_space_ctl *ctl,
47 struct btrfs_free_space *info);
48 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
49 struct btrfs_free_space *info, bool update_stat);
50 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
51 struct btrfs_free_space *bitmap_info, u64 *offset,
52 u64 *bytes, bool for_alloc);
53 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
54 struct btrfs_free_space *bitmap_info);
55 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
56 struct btrfs_free_space *info, u64 offset,
57 u64 bytes, bool update_stats);
58
59 static void btrfs_crc32c_final(u32 crc, u8 *result)
60 {
61 put_unaligned_le32(~crc, result);
62 }
63
64 static void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
65 {
66 struct btrfs_free_space *info;
67 struct rb_node *node;
68
69 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
70 info = rb_entry(node, struct btrfs_free_space, offset_index);
71 if (!info->bitmap) {
72 unlink_free_space(ctl, info, true);
73 kmem_cache_free(btrfs_free_space_cachep, info);
74 } else {
75 free_bitmap(ctl, info);
76 }
77
78 cond_resched_lock(&ctl->tree_lock);
79 }
80 }
81
82 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
83 struct btrfs_path *path,
84 u64 offset)
85 {
86 struct btrfs_key key;
87 struct btrfs_key location;
88 struct btrfs_disk_key disk_key;
89 struct btrfs_free_space_header *header;
90 struct extent_buffer *leaf;
91 struct inode *inode = NULL;
92 unsigned nofs_flag;
93 int ret;
94
95 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
96 key.offset = offset;
97 key.type = 0;
98
99 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
100 if (ret < 0)
101 return ERR_PTR(ret);
102 if (ret > 0) {
103 btrfs_release_path(path);
104 return ERR_PTR(-ENOENT);
105 }
106
107 leaf = path->nodes[0];
108 header = btrfs_item_ptr(leaf, path->slots[0],
109 struct btrfs_free_space_header);
110 btrfs_free_space_key(leaf, header, &disk_key);
111 btrfs_disk_key_to_cpu(&location, &disk_key);
112 btrfs_release_path(path);
113
114 /*
115 * We are often under a trans handle at this point, so we need to make
116 * sure NOFS is set to keep us from deadlocking.
117 */
118 nofs_flag = memalloc_nofs_save();
119 inode = btrfs_iget_path(location.objectid, root, path);
120 btrfs_release_path(path);
121 memalloc_nofs_restore(nofs_flag);
122 if (IS_ERR(inode))
123 return inode;
124
125 mapping_set_gfp_mask(inode->i_mapping,
126 mapping_gfp_constraint(inode->i_mapping,
127 ~(__GFP_FS | __GFP_HIGHMEM)));
128
129 return inode;
130 }
131
132 struct inode *lookup_free_space_inode(struct btrfs_block_group *block_group,
133 struct btrfs_path *path)
134 {
135 struct btrfs_fs_info *fs_info = block_group->fs_info;
136 struct inode *inode = NULL;
137 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
138
139 spin_lock(&block_group->lock);
140 if (block_group->inode)
141 inode = igrab(&block_group->inode->vfs_inode);
142 spin_unlock(&block_group->lock);
143 if (inode)
144 return inode;
145
146 inode = __lookup_free_space_inode(fs_info->tree_root, path,
147 block_group->start);
148 if (IS_ERR(inode))
149 return inode;
150
151 spin_lock(&block_group->lock);
152 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
153 btrfs_info(fs_info, "Old style space inode found, converting.");
154 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
155 BTRFS_INODE_NODATACOW;
156 block_group->disk_cache_state = BTRFS_DC_CLEAR;
157 }
158
159 if (!test_and_set_bit(BLOCK_GROUP_FLAG_IREF, &block_group->runtime_flags))
160 block_group->inode = BTRFS_I(igrab(inode));
161 spin_unlock(&block_group->lock);
162
163 return inode;
164 }
165
166 static int __create_free_space_inode(struct btrfs_root *root,
167 struct btrfs_trans_handle *trans,
168 struct btrfs_path *path,
169 u64 ino, u64 offset)
170 {
171 struct btrfs_key key;
172 struct btrfs_disk_key disk_key;
173 struct btrfs_free_space_header *header;
174 struct btrfs_inode_item *inode_item;
175 struct extent_buffer *leaf;
176 /* We inline CRCs for the free disk space cache */
177 const u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC |
178 BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
179 int ret;
180
181 ret = btrfs_insert_empty_inode(trans, root, path, ino);
182 if (ret)
183 return ret;
184
185 leaf = path->nodes[0];
186 inode_item = btrfs_item_ptr(leaf, path->slots[0],
187 struct btrfs_inode_item);
188 btrfs_item_key(leaf, &disk_key, path->slots[0]);
189 memzero_extent_buffer(leaf, (unsigned long)inode_item,
190 sizeof(*inode_item));
191 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
192 btrfs_set_inode_size(leaf, inode_item, 0);
193 btrfs_set_inode_nbytes(leaf, inode_item, 0);
194 btrfs_set_inode_uid(leaf, inode_item, 0);
195 btrfs_set_inode_gid(leaf, inode_item, 0);
196 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
197 btrfs_set_inode_flags(leaf, inode_item, flags);
198 btrfs_set_inode_nlink(leaf, inode_item, 1);
199 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
200 btrfs_set_inode_block_group(leaf, inode_item, offset);
201 btrfs_release_path(path);
202
203 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
204 key.offset = offset;
205 key.type = 0;
206 ret = btrfs_insert_empty_item(trans, root, path, &key,
207 sizeof(struct btrfs_free_space_header));
208 if (ret < 0) {
209 btrfs_release_path(path);
210 return ret;
211 }
212
213 leaf = path->nodes[0];
214 header = btrfs_item_ptr(leaf, path->slots[0],
215 struct btrfs_free_space_header);
216 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
217 btrfs_set_free_space_key(leaf, header, &disk_key);
218 btrfs_release_path(path);
219
220 return 0;
221 }
222
223 int create_free_space_inode(struct btrfs_trans_handle *trans,
224 struct btrfs_block_group *block_group,
225 struct btrfs_path *path)
226 {
227 int ret;
228 u64 ino;
229
230 ret = btrfs_get_free_objectid(trans->fs_info->tree_root, &ino);
231 if (ret < 0)
232 return ret;
233
234 return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
235 ino, block_group->start);
236 }
237
238 /*
239 * inode is an optional sink: if it is NULL, btrfs_remove_free_space_inode
240 * handles lookup, otherwise it takes ownership and iputs the inode.
241 * Don't reuse an inode pointer after passing it into this function.
242 */
243 int btrfs_remove_free_space_inode(struct btrfs_trans_handle *trans,
244 struct inode *inode,
245 struct btrfs_block_group *block_group)
246 {
247 struct btrfs_path *path;
248 struct btrfs_key key;
249 int ret = 0;
250
251 path = btrfs_alloc_path();
252 if (!path)
253 return -ENOMEM;
254
255 if (!inode)
256 inode = lookup_free_space_inode(block_group, path);
257 if (IS_ERR(inode)) {
258 if (PTR_ERR(inode) != -ENOENT)
259 ret = PTR_ERR(inode);
260 goto out;
261 }
262 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
263 if (ret) {
264 btrfs_add_delayed_iput(BTRFS_I(inode));
265 goto out;
266 }
267 clear_nlink(inode);
268 /* One for the block groups ref */
269 spin_lock(&block_group->lock);
270 if (test_and_clear_bit(BLOCK_GROUP_FLAG_IREF, &block_group->runtime_flags)) {
271 block_group->inode = NULL;
272 spin_unlock(&block_group->lock);
273 iput(inode);
274 } else {
275 spin_unlock(&block_group->lock);
276 }
277 /* One for the lookup ref */
278 btrfs_add_delayed_iput(BTRFS_I(inode));
279
280 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
281 key.type = 0;
282 key.offset = block_group->start;
283 ret = btrfs_search_slot(trans, trans->fs_info->tree_root, &key, path,
284 -1, 1);
285 if (ret) {
286 if (ret > 0)
287 ret = 0;
288 goto out;
289 }
290 ret = btrfs_del_item(trans, trans->fs_info->tree_root, path);
291 out:
292 btrfs_free_path(path);
293 return ret;
294 }
295
296 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
297 struct btrfs_block_group *block_group,
298 struct inode *vfs_inode)
299 {
300 struct btrfs_truncate_control control = {
301 .inode = BTRFS_I(vfs_inode),
302 .new_size = 0,
303 .ino = btrfs_ino(BTRFS_I(vfs_inode)),
304 .min_type = BTRFS_EXTENT_DATA_KEY,
305 .clear_extent_range = true,
306 };
307 struct btrfs_inode *inode = BTRFS_I(vfs_inode);
308 struct btrfs_root *root = inode->root;
309 struct extent_state *cached_state = NULL;
310 int ret = 0;
311 bool locked = false;
312
313 if (block_group) {
314 struct btrfs_path *path = btrfs_alloc_path();
315
316 if (!path) {
317 ret = -ENOMEM;
318 goto fail;
319 }
320 locked = true;
321 mutex_lock(&trans->transaction->cache_write_mutex);
322 if (!list_empty(&block_group->io_list)) {
323 list_del_init(&block_group->io_list);
324
325 btrfs_wait_cache_io(trans, block_group, path);
326 btrfs_put_block_group(block_group);
327 }
328
329 /*
330 * now that we've truncated the cache away, its no longer
331 * setup or written
332 */
333 spin_lock(&block_group->lock);
334 block_group->disk_cache_state = BTRFS_DC_CLEAR;
335 spin_unlock(&block_group->lock);
336 btrfs_free_path(path);
337 }
338
339 btrfs_i_size_write(inode, 0);
340 truncate_pagecache(vfs_inode, 0);
341
342 lock_extent(&inode->io_tree, 0, (u64)-1, &cached_state);
343 btrfs_drop_extent_map_range(inode, 0, (u64)-1, false);
344
345 /*
346 * We skip the throttling logic for free space cache inodes, so we don't
347 * need to check for -EAGAIN.
348 */
349 ret = btrfs_truncate_inode_items(trans, root, &control);
350
351 inode_sub_bytes(&inode->vfs_inode, control.sub_bytes);
352 btrfs_inode_safe_disk_i_size_write(inode, control.last_size);
353
354 unlock_extent(&inode->io_tree, 0, (u64)-1, &cached_state);
355 if (ret)
356 goto fail;
357
358 ret = btrfs_update_inode(trans, inode);
359
360 fail:
361 if (locked)
362 mutex_unlock(&trans->transaction->cache_write_mutex);
363 if (ret)
364 btrfs_abort_transaction(trans, ret);
365
366 return ret;
367 }
368
369 static void readahead_cache(struct inode *inode)
370 {
371 struct file_ra_state ra;
372 unsigned long last_index;
373
374 file_ra_state_init(&ra, inode->i_mapping);
375 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
376
377 page_cache_sync_readahead(inode->i_mapping, &ra, NULL, 0, last_index);
378 }
379
380 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
381 int write)
382 {
383 int num_pages;
384
385 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
386
387 /* Make sure we can fit our crcs and generation into the first page */
388 if (write && (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
389 return -ENOSPC;
390
391 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
392
393 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
394 if (!io_ctl->pages)
395 return -ENOMEM;
396
397 io_ctl->num_pages = num_pages;
398 io_ctl->fs_info = inode_to_fs_info(inode);
399 io_ctl->inode = inode;
400
401 return 0;
402 }
403 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
404
405 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
406 {
407 kfree(io_ctl->pages);
408 io_ctl->pages = NULL;
409 }
410
411 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
412 {
413 if (io_ctl->cur) {
414 io_ctl->cur = NULL;
415 io_ctl->orig = NULL;
416 }
417 }
418
419 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
420 {
421 ASSERT(io_ctl->index < io_ctl->num_pages);
422 io_ctl->page = io_ctl->pages[io_ctl->index++];
423 io_ctl->cur = page_address(io_ctl->page);
424 io_ctl->orig = io_ctl->cur;
425 io_ctl->size = PAGE_SIZE;
426 if (clear)
427 clear_page(io_ctl->cur);
428 }
429
430 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
431 {
432 int i;
433
434 io_ctl_unmap_page(io_ctl);
435
436 for (i = 0; i < io_ctl->num_pages; i++) {
437 if (io_ctl->pages[i]) {
438 btrfs_folio_clear_checked(io_ctl->fs_info,
439 page_folio(io_ctl->pages[i]),
440 page_offset(io_ctl->pages[i]),
441 PAGE_SIZE);
442 unlock_page(io_ctl->pages[i]);
443 put_page(io_ctl->pages[i]);
444 }
445 }
446 }
447
448 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, bool uptodate)
449 {
450 struct page *page;
451 struct inode *inode = io_ctl->inode;
452 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
453 int i;
454
455 for (i = 0; i < io_ctl->num_pages; i++) {
456 int ret;
457
458 page = find_or_create_page(inode->i_mapping, i, mask);
459 if (!page) {
460 io_ctl_drop_pages(io_ctl);
461 return -ENOMEM;
462 }
463
464 ret = set_folio_extent_mapped(page_folio(page));
465 if (ret < 0) {
466 unlock_page(page);
467 put_page(page);
468 io_ctl_drop_pages(io_ctl);
469 return ret;
470 }
471
472 io_ctl->pages[i] = page;
473 if (uptodate && !PageUptodate(page)) {
474 btrfs_read_folio(NULL, page_folio(page));
475 lock_page(page);
476 if (page->mapping != inode->i_mapping) {
477 btrfs_err(BTRFS_I(inode)->root->fs_info,
478 "free space cache page truncated");
479 io_ctl_drop_pages(io_ctl);
480 return -EIO;
481 }
482 if (!PageUptodate(page)) {
483 btrfs_err(BTRFS_I(inode)->root->fs_info,
484 "error reading free space cache");
485 io_ctl_drop_pages(io_ctl);
486 return -EIO;
487 }
488 }
489 }
490
491 for (i = 0; i < io_ctl->num_pages; i++)
492 clear_page_dirty_for_io(io_ctl->pages[i]);
493
494 return 0;
495 }
496
497 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
498 {
499 io_ctl_map_page(io_ctl, 1);
500
501 /*
502 * Skip the csum areas. If we don't check crcs then we just have a
503 * 64bit chunk at the front of the first page.
504 */
505 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
506 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
507
508 put_unaligned_le64(generation, io_ctl->cur);
509 io_ctl->cur += sizeof(u64);
510 }
511
512 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
513 {
514 u64 cache_gen;
515
516 /*
517 * Skip the crc area. If we don't check crcs then we just have a 64bit
518 * chunk at the front of the first page.
519 */
520 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
521 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
522
523 cache_gen = get_unaligned_le64(io_ctl->cur);
524 if (cache_gen != generation) {
525 btrfs_err_rl(io_ctl->fs_info,
526 "space cache generation (%llu) does not match inode (%llu)",
527 cache_gen, generation);
528 io_ctl_unmap_page(io_ctl);
529 return -EIO;
530 }
531 io_ctl->cur += sizeof(u64);
532 return 0;
533 }
534
535 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
536 {
537 u32 *tmp;
538 u32 crc = ~(u32)0;
539 unsigned offset = 0;
540
541 if (index == 0)
542 offset = sizeof(u32) * io_ctl->num_pages;
543
544 crc = crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
545 btrfs_crc32c_final(crc, (u8 *)&crc);
546 io_ctl_unmap_page(io_ctl);
547 tmp = page_address(io_ctl->pages[0]);
548 tmp += index;
549 *tmp = crc;
550 }
551
552 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
553 {
554 u32 *tmp, val;
555 u32 crc = ~(u32)0;
556 unsigned offset = 0;
557
558 if (index == 0)
559 offset = sizeof(u32) * io_ctl->num_pages;
560
561 tmp = page_address(io_ctl->pages[0]);
562 tmp += index;
563 val = *tmp;
564
565 io_ctl_map_page(io_ctl, 0);
566 crc = crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
567 btrfs_crc32c_final(crc, (u8 *)&crc);
568 if (val != crc) {
569 btrfs_err_rl(io_ctl->fs_info,
570 "csum mismatch on free space cache");
571 io_ctl_unmap_page(io_ctl);
572 return -EIO;
573 }
574
575 return 0;
576 }
577
578 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
579 void *bitmap)
580 {
581 struct btrfs_free_space_entry *entry;
582
583 if (!io_ctl->cur)
584 return -ENOSPC;
585
586 entry = io_ctl->cur;
587 put_unaligned_le64(offset, &entry->offset);
588 put_unaligned_le64(bytes, &entry->bytes);
589 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
590 BTRFS_FREE_SPACE_EXTENT;
591 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
592 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
593
594 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
595 return 0;
596
597 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
598
599 /* No more pages to map */
600 if (io_ctl->index >= io_ctl->num_pages)
601 return 0;
602
603 /* map the next page */
604 io_ctl_map_page(io_ctl, 1);
605 return 0;
606 }
607
608 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
609 {
610 if (!io_ctl->cur)
611 return -ENOSPC;
612
613 /*
614 * If we aren't at the start of the current page, unmap this one and
615 * map the next one if there is any left.
616 */
617 if (io_ctl->cur != io_ctl->orig) {
618 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
619 if (io_ctl->index >= io_ctl->num_pages)
620 return -ENOSPC;
621 io_ctl_map_page(io_ctl, 0);
622 }
623
624 copy_page(io_ctl->cur, bitmap);
625 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
626 if (io_ctl->index < io_ctl->num_pages)
627 io_ctl_map_page(io_ctl, 0);
628 return 0;
629 }
630
631 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
632 {
633 /*
634 * If we're not on the boundary we know we've modified the page and we
635 * need to crc the page.
636 */
637 if (io_ctl->cur != io_ctl->orig)
638 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
639 else
640 io_ctl_unmap_page(io_ctl);
641
642 while (io_ctl->index < io_ctl->num_pages) {
643 io_ctl_map_page(io_ctl, 1);
644 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
645 }
646 }
647
648 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
649 struct btrfs_free_space *entry, u8 *type)
650 {
651 struct btrfs_free_space_entry *e;
652 int ret;
653
654 if (!io_ctl->cur) {
655 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
656 if (ret)
657 return ret;
658 }
659
660 e = io_ctl->cur;
661 entry->offset = get_unaligned_le64(&e->offset);
662 entry->bytes = get_unaligned_le64(&e->bytes);
663 *type = e->type;
664 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
665 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
666
667 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
668 return 0;
669
670 io_ctl_unmap_page(io_ctl);
671
672 return 0;
673 }
674
675 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
676 struct btrfs_free_space *entry)
677 {
678 int ret;
679
680 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
681 if (ret)
682 return ret;
683
684 copy_page(entry->bitmap, io_ctl->cur);
685 io_ctl_unmap_page(io_ctl);
686
687 return 0;
688 }
689
690 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
691 {
692 struct btrfs_block_group *block_group = ctl->block_group;
693 u64 max_bytes;
694 u64 bitmap_bytes;
695 u64 extent_bytes;
696 u64 size = block_group->length;
697 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
698 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
699
700 max_bitmaps = max_t(u64, max_bitmaps, 1);
701
702 if (ctl->total_bitmaps > max_bitmaps)
703 btrfs_err(block_group->fs_info,
704 "invalid free space control: bg start=%llu len=%llu total_bitmaps=%u unit=%u max_bitmaps=%llu bytes_per_bg=%llu",
705 block_group->start, block_group->length,
706 ctl->total_bitmaps, ctl->unit, max_bitmaps,
707 bytes_per_bg);
708 ASSERT(ctl->total_bitmaps <= max_bitmaps);
709
710 /*
711 * We are trying to keep the total amount of memory used per 1GiB of
712 * space to be MAX_CACHE_BYTES_PER_GIG. However, with a reclamation
713 * mechanism of pulling extents >= FORCE_EXTENT_THRESHOLD out of
714 * bitmaps, we may end up using more memory than this.
715 */
716 if (size < SZ_1G)
717 max_bytes = MAX_CACHE_BYTES_PER_GIG;
718 else
719 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
720
721 bitmap_bytes = ctl->total_bitmaps * ctl->unit;
722
723 /*
724 * we want the extent entry threshold to always be at most 1/2 the max
725 * bytes we can have, or whatever is less than that.
726 */
727 extent_bytes = max_bytes - bitmap_bytes;
728 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
729
730 ctl->extents_thresh =
731 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
732 }
733
734 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
735 struct btrfs_free_space_ctl *ctl,
736 struct btrfs_path *path, u64 offset)
737 {
738 struct btrfs_fs_info *fs_info = root->fs_info;
739 struct btrfs_free_space_header *header;
740 struct extent_buffer *leaf;
741 struct btrfs_io_ctl io_ctl;
742 struct btrfs_key key;
743 struct btrfs_free_space *e, *n;
744 LIST_HEAD(bitmaps);
745 u64 num_entries;
746 u64 num_bitmaps;
747 u64 generation;
748 u8 type;
749 int ret = 0;
750
751 /* Nothing in the space cache, goodbye */
752 if (!i_size_read(inode))
753 return 0;
754
755 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
756 key.offset = offset;
757 key.type = 0;
758
759 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
760 if (ret < 0)
761 return 0;
762 else if (ret > 0) {
763 btrfs_release_path(path);
764 return 0;
765 }
766
767 ret = -1;
768
769 leaf = path->nodes[0];
770 header = btrfs_item_ptr(leaf, path->slots[0],
771 struct btrfs_free_space_header);
772 num_entries = btrfs_free_space_entries(leaf, header);
773 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
774 generation = btrfs_free_space_generation(leaf, header);
775 btrfs_release_path(path);
776
777 if (!BTRFS_I(inode)->generation) {
778 btrfs_info(fs_info,
779 "the free space cache file (%llu) is invalid, skip it",
780 offset);
781 return 0;
782 }
783
784 if (BTRFS_I(inode)->generation != generation) {
785 btrfs_err(fs_info,
786 "free space inode generation (%llu) did not match free space cache generation (%llu)",
787 BTRFS_I(inode)->generation, generation);
788 return 0;
789 }
790
791 if (!num_entries)
792 return 0;
793
794 ret = io_ctl_init(&io_ctl, inode, 0);
795 if (ret)
796 return ret;
797
798 readahead_cache(inode);
799
800 ret = io_ctl_prepare_pages(&io_ctl, true);
801 if (ret)
802 goto out;
803
804 ret = io_ctl_check_crc(&io_ctl, 0);
805 if (ret)
806 goto free_cache;
807
808 ret = io_ctl_check_generation(&io_ctl, generation);
809 if (ret)
810 goto free_cache;
811
812 while (num_entries) {
813 e = kmem_cache_zalloc(btrfs_free_space_cachep,
814 GFP_NOFS);
815 if (!e) {
816 ret = -ENOMEM;
817 goto free_cache;
818 }
819
820 ret = io_ctl_read_entry(&io_ctl, e, &type);
821 if (ret) {
822 kmem_cache_free(btrfs_free_space_cachep, e);
823 goto free_cache;
824 }
825
826 if (!e->bytes) {
827 ret = -1;
828 kmem_cache_free(btrfs_free_space_cachep, e);
829 goto free_cache;
830 }
831
832 if (type == BTRFS_FREE_SPACE_EXTENT) {
833 spin_lock(&ctl->tree_lock);
834 ret = link_free_space(ctl, e);
835 spin_unlock(&ctl->tree_lock);
836 if (ret) {
837 btrfs_err(fs_info,
838 "Duplicate entries in free space cache, dumping");
839 kmem_cache_free(btrfs_free_space_cachep, e);
840 goto free_cache;
841 }
842 } else {
843 ASSERT(num_bitmaps);
844 num_bitmaps--;
845 e->bitmap = kmem_cache_zalloc(
846 btrfs_free_space_bitmap_cachep, GFP_NOFS);
847 if (!e->bitmap) {
848 ret = -ENOMEM;
849 kmem_cache_free(
850 btrfs_free_space_cachep, e);
851 goto free_cache;
852 }
853 spin_lock(&ctl->tree_lock);
854 ret = link_free_space(ctl, e);
855 if (ret) {
856 spin_unlock(&ctl->tree_lock);
857 btrfs_err(fs_info,
858 "Duplicate entries in free space cache, dumping");
859 kmem_cache_free(btrfs_free_space_bitmap_cachep, e->bitmap);
860 kmem_cache_free(btrfs_free_space_cachep, e);
861 goto free_cache;
862 }
863 ctl->total_bitmaps++;
864 recalculate_thresholds(ctl);
865 spin_unlock(&ctl->tree_lock);
866 list_add_tail(&e->list, &bitmaps);
867 }
868
869 num_entries--;
870 }
871
872 io_ctl_unmap_page(&io_ctl);
873
874 /*
875 * We add the bitmaps at the end of the entries in order that
876 * the bitmap entries are added to the cache.
877 */
878 list_for_each_entry_safe(e, n, &bitmaps, list) {
879 list_del_init(&e->list);
880 ret = io_ctl_read_bitmap(&io_ctl, e);
881 if (ret)
882 goto free_cache;
883 }
884
885 io_ctl_drop_pages(&io_ctl);
886 ret = 1;
887 out:
888 io_ctl_free(&io_ctl);
889 return ret;
890 free_cache:
891 io_ctl_drop_pages(&io_ctl);
892
893 spin_lock(&ctl->tree_lock);
894 __btrfs_remove_free_space_cache(ctl);
895 spin_unlock(&ctl->tree_lock);
896 goto out;
897 }
898
899 static int copy_free_space_cache(struct btrfs_block_group *block_group,
900 struct btrfs_free_space_ctl *ctl)
901 {
902 struct btrfs_free_space *info;
903 struct rb_node *n;
904 int ret = 0;
905
906 while (!ret && (n = rb_first(&ctl->free_space_offset)) != NULL) {
907 info = rb_entry(n, struct btrfs_free_space, offset_index);
908 if (!info->bitmap) {
909 const u64 offset = info->offset;
910 const u64 bytes = info->bytes;
911
912 unlink_free_space(ctl, info, true);
913 spin_unlock(&ctl->tree_lock);
914 kmem_cache_free(btrfs_free_space_cachep, info);
915 ret = btrfs_add_free_space(block_group, offset, bytes);
916 spin_lock(&ctl->tree_lock);
917 } else {
918 u64 offset = info->offset;
919 u64 bytes = ctl->unit;
920
921 ret = search_bitmap(ctl, info, &offset, &bytes, false);
922 if (ret == 0) {
923 bitmap_clear_bits(ctl, info, offset, bytes, true);
924 spin_unlock(&ctl->tree_lock);
925 ret = btrfs_add_free_space(block_group, offset,
926 bytes);
927 spin_lock(&ctl->tree_lock);
928 } else {
929 free_bitmap(ctl, info);
930 ret = 0;
931 }
932 }
933 cond_resched_lock(&ctl->tree_lock);
934 }
935 return ret;
936 }
937
938 static struct lock_class_key btrfs_free_space_inode_key;
939
940 int load_free_space_cache(struct btrfs_block_group *block_group)
941 {
942 struct btrfs_fs_info *fs_info = block_group->fs_info;
943 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
944 struct btrfs_free_space_ctl tmp_ctl = {};
945 struct inode *inode;
946 struct btrfs_path *path;
947 int ret = 0;
948 bool matched;
949 u64 used = block_group->used;
950
951 /*
952 * Because we could potentially discard our loaded free space, we want
953 * to load everything into a temporary structure first, and then if it's
954 * valid copy it all into the actual free space ctl.
955 */
956 btrfs_init_free_space_ctl(block_group, &tmp_ctl);
957
958 /*
959 * If this block group has been marked to be cleared for one reason or
960 * another then we can't trust the on disk cache, so just return.
961 */
962 spin_lock(&block_group->lock);
963 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
964 spin_unlock(&block_group->lock);
965 return 0;
966 }
967 spin_unlock(&block_group->lock);
968
969 path = btrfs_alloc_path();
970 if (!path)
971 return 0;
972 path->search_commit_root = 1;
973 path->skip_locking = 1;
974
975 /*
976 * We must pass a path with search_commit_root set to btrfs_iget in
977 * order to avoid a deadlock when allocating extents for the tree root.
978 *
979 * When we are COWing an extent buffer from the tree root, when looking
980 * for a free extent, at extent-tree.c:find_free_extent(), we can find
981 * block group without its free space cache loaded. When we find one
982 * we must load its space cache which requires reading its free space
983 * cache's inode item from the root tree. If this inode item is located
984 * in the same leaf that we started COWing before, then we end up in
985 * deadlock on the extent buffer (trying to read lock it when we
986 * previously write locked it).
987 *
988 * It's safe to read the inode item using the commit root because
989 * block groups, once loaded, stay in memory forever (until they are
990 * removed) as well as their space caches once loaded. New block groups
991 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
992 * we will never try to read their inode item while the fs is mounted.
993 */
994 inode = lookup_free_space_inode(block_group, path);
995 if (IS_ERR(inode)) {
996 btrfs_free_path(path);
997 return 0;
998 }
999
1000 /* We may have converted the inode and made the cache invalid. */
1001 spin_lock(&block_group->lock);
1002 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
1003 spin_unlock(&block_group->lock);
1004 btrfs_free_path(path);
1005 goto out;
1006 }
1007 spin_unlock(&block_group->lock);
1008
1009 /*
1010 * Reinitialize the class of struct inode's mapping->invalidate_lock for
1011 * free space inodes to prevent false positives related to locks for normal
1012 * inodes.
1013 */
1014 lockdep_set_class(&(&inode->i_data)->invalidate_lock,
1015 &btrfs_free_space_inode_key);
1016
1017 ret = __load_free_space_cache(fs_info->tree_root, inode, &tmp_ctl,
1018 path, block_group->start);
1019 btrfs_free_path(path);
1020 if (ret <= 0)
1021 goto out;
1022
1023 matched = (tmp_ctl.free_space == (block_group->length - used -
1024 block_group->bytes_super));
1025
1026 if (matched) {
1027 spin_lock(&tmp_ctl.tree_lock);
1028 ret = copy_free_space_cache(block_group, &tmp_ctl);
1029 spin_unlock(&tmp_ctl.tree_lock);
1030 /*
1031 * ret == 1 means we successfully loaded the free space cache,
1032 * so we need to re-set it here.
1033 */
1034 if (ret == 0)
1035 ret = 1;
1036 } else {
1037 /*
1038 * We need to call the _locked variant so we don't try to update
1039 * the discard counters.
1040 */
1041 spin_lock(&tmp_ctl.tree_lock);
1042 __btrfs_remove_free_space_cache(&tmp_ctl);
1043 spin_unlock(&tmp_ctl.tree_lock);
1044 btrfs_warn(fs_info,
1045 "block group %llu has wrong amount of free space",
1046 block_group->start);
1047 ret = -1;
1048 }
1049 out:
1050 if (ret < 0) {
1051 /* This cache is bogus, make sure it gets cleared */
1052 spin_lock(&block_group->lock);
1053 block_group->disk_cache_state = BTRFS_DC_CLEAR;
1054 spin_unlock(&block_group->lock);
1055 ret = 0;
1056
1057 btrfs_warn(fs_info,
1058 "failed to load free space cache for block group %llu, rebuilding it now",
1059 block_group->start);
1060 }
1061
1062 spin_lock(&ctl->tree_lock);
1063 btrfs_discard_update_discardable(block_group);
1064 spin_unlock(&ctl->tree_lock);
1065 iput(inode);
1066 return ret;
1067 }
1068
1069 static noinline_for_stack
1070 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
1071 struct btrfs_free_space_ctl *ctl,
1072 struct btrfs_block_group *block_group,
1073 int *entries, int *bitmaps,
1074 struct list_head *bitmap_list)
1075 {
1076 int ret;
1077 struct btrfs_free_cluster *cluster = NULL;
1078 struct btrfs_free_cluster *cluster_locked = NULL;
1079 struct rb_node *node = rb_first(&ctl->free_space_offset);
1080 struct btrfs_trim_range *trim_entry;
1081
1082 /* Get the cluster for this block_group if it exists */
1083 if (block_group && !list_empty(&block_group->cluster_list)) {
1084 cluster = list_entry(block_group->cluster_list.next,
1085 struct btrfs_free_cluster,
1086 block_group_list);
1087 }
1088
1089 if (!node && cluster) {
1090 cluster_locked = cluster;
1091 spin_lock(&cluster_locked->lock);
1092 node = rb_first(&cluster->root);
1093 cluster = NULL;
1094 }
1095
1096 /* Write out the extent entries */
1097 while (node) {
1098 struct btrfs_free_space *e;
1099
1100 e = rb_entry(node, struct btrfs_free_space, offset_index);
1101 *entries += 1;
1102
1103 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
1104 e->bitmap);
1105 if (ret)
1106 goto fail;
1107
1108 if (e->bitmap) {
1109 list_add_tail(&e->list, bitmap_list);
1110 *bitmaps += 1;
1111 }
1112 node = rb_next(node);
1113 if (!node && cluster) {
1114 node = rb_first(&cluster->root);
1115 cluster_locked = cluster;
1116 spin_lock(&cluster_locked->lock);
1117 cluster = NULL;
1118 }
1119 }
1120 if (cluster_locked) {
1121 spin_unlock(&cluster_locked->lock);
1122 cluster_locked = NULL;
1123 }
1124
1125 /*
1126 * Make sure we don't miss any range that was removed from our rbtree
1127 * because trimming is running. Otherwise after a umount+mount (or crash
1128 * after committing the transaction) we would leak free space and get
1129 * an inconsistent free space cache report from fsck.
1130 */
1131 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
1132 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
1133 trim_entry->bytes, NULL);
1134 if (ret)
1135 goto fail;
1136 *entries += 1;
1137 }
1138
1139 return 0;
1140 fail:
1141 if (cluster_locked)
1142 spin_unlock(&cluster_locked->lock);
1143 return -ENOSPC;
1144 }
1145
1146 static noinline_for_stack int
1147 update_cache_item(struct btrfs_trans_handle *trans,
1148 struct btrfs_root *root,
1149 struct inode *inode,
1150 struct btrfs_path *path, u64 offset,
1151 int entries, int bitmaps)
1152 {
1153 struct btrfs_key key;
1154 struct btrfs_free_space_header *header;
1155 struct extent_buffer *leaf;
1156 int ret;
1157
1158 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1159 key.offset = offset;
1160 key.type = 0;
1161
1162 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1163 if (ret < 0) {
1164 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1165 EXTENT_DELALLOC, NULL);
1166 goto fail;
1167 }
1168 leaf = path->nodes[0];
1169 if (ret > 0) {
1170 struct btrfs_key found_key;
1171 ASSERT(path->slots[0]);
1172 path->slots[0]--;
1173 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1174 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1175 found_key.offset != offset) {
1176 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1177 inode->i_size - 1, EXTENT_DELALLOC,
1178 NULL);
1179 btrfs_release_path(path);
1180 goto fail;
1181 }
1182 }
1183
1184 BTRFS_I(inode)->generation = trans->transid;
1185 header = btrfs_item_ptr(leaf, path->slots[0],
1186 struct btrfs_free_space_header);
1187 btrfs_set_free_space_entries(leaf, header, entries);
1188 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1189 btrfs_set_free_space_generation(leaf, header, trans->transid);
1190 btrfs_release_path(path);
1191
1192 return 0;
1193
1194 fail:
1195 return -1;
1196 }
1197
1198 static noinline_for_stack int write_pinned_extent_entries(
1199 struct btrfs_trans_handle *trans,
1200 struct btrfs_block_group *block_group,
1201 struct btrfs_io_ctl *io_ctl,
1202 int *entries)
1203 {
1204 u64 start, extent_start, extent_end, len;
1205 struct extent_io_tree *unpin = NULL;
1206 int ret;
1207
1208 if (!block_group)
1209 return 0;
1210
1211 /*
1212 * We want to add any pinned extents to our free space cache
1213 * so we don't leak the space
1214 *
1215 * We shouldn't have switched the pinned extents yet so this is the
1216 * right one
1217 */
1218 unpin = &trans->transaction->pinned_extents;
1219
1220 start = block_group->start;
1221
1222 while (start < block_group->start + block_group->length) {
1223 if (!find_first_extent_bit(unpin, start,
1224 &extent_start, &extent_end,
1225 EXTENT_DIRTY, NULL))
1226 return 0;
1227
1228 /* This pinned extent is out of our range */
1229 if (extent_start >= block_group->start + block_group->length)
1230 return 0;
1231
1232 extent_start = max(extent_start, start);
1233 extent_end = min(block_group->start + block_group->length,
1234 extent_end + 1);
1235 len = extent_end - extent_start;
1236
1237 *entries += 1;
1238 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1239 if (ret)
1240 return -ENOSPC;
1241
1242 start = extent_end;
1243 }
1244
1245 return 0;
1246 }
1247
1248 static noinline_for_stack int
1249 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1250 {
1251 struct btrfs_free_space *entry, *next;
1252 int ret;
1253
1254 /* Write out the bitmaps */
1255 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1256 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1257 if (ret)
1258 return -ENOSPC;
1259 list_del_init(&entry->list);
1260 }
1261
1262 return 0;
1263 }
1264
1265 static int flush_dirty_cache(struct inode *inode)
1266 {
1267 int ret;
1268
1269 ret = btrfs_wait_ordered_range(BTRFS_I(inode), 0, (u64)-1);
1270 if (ret)
1271 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1272 EXTENT_DELALLOC, NULL);
1273
1274 return ret;
1275 }
1276
1277 static void noinline_for_stack
1278 cleanup_bitmap_list(struct list_head *bitmap_list)
1279 {
1280 struct btrfs_free_space *entry, *next;
1281
1282 list_for_each_entry_safe(entry, next, bitmap_list, list)
1283 list_del_init(&entry->list);
1284 }
1285
1286 static void noinline_for_stack
1287 cleanup_write_cache_enospc(struct inode *inode,
1288 struct btrfs_io_ctl *io_ctl,
1289 struct extent_state **cached_state)
1290 {
1291 io_ctl_drop_pages(io_ctl);
1292 unlock_extent(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1293 cached_state);
1294 }
1295
1296 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1297 struct btrfs_trans_handle *trans,
1298 struct btrfs_block_group *block_group,
1299 struct btrfs_io_ctl *io_ctl,
1300 struct btrfs_path *path, u64 offset)
1301 {
1302 int ret;
1303 struct inode *inode = io_ctl->inode;
1304
1305 if (!inode)
1306 return 0;
1307
1308 /* Flush the dirty pages in the cache file. */
1309 ret = flush_dirty_cache(inode);
1310 if (ret)
1311 goto out;
1312
1313 /* Update the cache item to tell everyone this cache file is valid. */
1314 ret = update_cache_item(trans, root, inode, path, offset,
1315 io_ctl->entries, io_ctl->bitmaps);
1316 out:
1317 if (ret) {
1318 invalidate_inode_pages2(inode->i_mapping);
1319 BTRFS_I(inode)->generation = 0;
1320 if (block_group)
1321 btrfs_debug(root->fs_info,
1322 "failed to write free space cache for block group %llu error %d",
1323 block_group->start, ret);
1324 }
1325 btrfs_update_inode(trans, BTRFS_I(inode));
1326
1327 if (block_group) {
1328 /* the dirty list is protected by the dirty_bgs_lock */
1329 spin_lock(&trans->transaction->dirty_bgs_lock);
1330
1331 /* the disk_cache_state is protected by the block group lock */
1332 spin_lock(&block_group->lock);
1333
1334 /*
1335 * only mark this as written if we didn't get put back on
1336 * the dirty list while waiting for IO. Otherwise our
1337 * cache state won't be right, and we won't get written again
1338 */
1339 if (!ret && list_empty(&block_group->dirty_list))
1340 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1341 else if (ret)
1342 block_group->disk_cache_state = BTRFS_DC_ERROR;
1343
1344 spin_unlock(&block_group->lock);
1345 spin_unlock(&trans->transaction->dirty_bgs_lock);
1346 io_ctl->inode = NULL;
1347 iput(inode);
1348 }
1349
1350 return ret;
1351
1352 }
1353
1354 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1355 struct btrfs_block_group *block_group,
1356 struct btrfs_path *path)
1357 {
1358 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1359 block_group, &block_group->io_ctl,
1360 path, block_group->start);
1361 }
1362
1363 /*
1364 * Write out cached info to an inode.
1365 *
1366 * @inode: freespace inode we are writing out
1367 * @ctl: free space cache we are going to write out
1368 * @block_group: block_group for this cache if it belongs to a block_group
1369 * @io_ctl: holds context for the io
1370 * @trans: the trans handle
1371 *
1372 * This function writes out a free space cache struct to disk for quick recovery
1373 * on mount. This will return 0 if it was successful in writing the cache out,
1374 * or an errno if it was not.
1375 */
1376 static int __btrfs_write_out_cache(struct inode *inode,
1377 struct btrfs_free_space_ctl *ctl,
1378 struct btrfs_block_group *block_group,
1379 struct btrfs_io_ctl *io_ctl,
1380 struct btrfs_trans_handle *trans)
1381 {
1382 struct extent_state *cached_state = NULL;
1383 LIST_HEAD(bitmap_list);
1384 int entries = 0;
1385 int bitmaps = 0;
1386 int ret;
1387 int must_iput = 0;
1388 int i_size;
1389
1390 if (!i_size_read(inode))
1391 return -EIO;
1392
1393 WARN_ON(io_ctl->pages);
1394 ret = io_ctl_init(io_ctl, inode, 1);
1395 if (ret)
1396 return ret;
1397
1398 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1399 down_write(&block_group->data_rwsem);
1400 spin_lock(&block_group->lock);
1401 if (block_group->delalloc_bytes) {
1402 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1403 spin_unlock(&block_group->lock);
1404 up_write(&block_group->data_rwsem);
1405 BTRFS_I(inode)->generation = 0;
1406 ret = 0;
1407 must_iput = 1;
1408 goto out;
1409 }
1410 spin_unlock(&block_group->lock);
1411 }
1412
1413 /* Lock all pages first so we can lock the extent safely. */
1414 ret = io_ctl_prepare_pages(io_ctl, false);
1415 if (ret)
1416 goto out_unlock;
1417
1418 lock_extent(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1419 &cached_state);
1420
1421 io_ctl_set_generation(io_ctl, trans->transid);
1422
1423 mutex_lock(&ctl->cache_writeout_mutex);
1424 /* Write out the extent entries in the free space cache */
1425 spin_lock(&ctl->tree_lock);
1426 ret = write_cache_extent_entries(io_ctl, ctl,
1427 block_group, &entries, &bitmaps,
1428 &bitmap_list);
1429 if (ret)
1430 goto out_nospc_locked;
1431
1432 /*
1433 * Some spaces that are freed in the current transaction are pinned,
1434 * they will be added into free space cache after the transaction is
1435 * committed, we shouldn't lose them.
1436 *
1437 * If this changes while we are working we'll get added back to
1438 * the dirty list and redo it. No locking needed
1439 */
1440 ret = write_pinned_extent_entries(trans, block_group, io_ctl, &entries);
1441 if (ret)
1442 goto out_nospc_locked;
1443
1444 /*
1445 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1446 * locked while doing it because a concurrent trim can be manipulating
1447 * or freeing the bitmap.
1448 */
1449 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1450 spin_unlock(&ctl->tree_lock);
1451 mutex_unlock(&ctl->cache_writeout_mutex);
1452 if (ret)
1453 goto out_nospc;
1454
1455 /* Zero out the rest of the pages just to make sure */
1456 io_ctl_zero_remaining_pages(io_ctl);
1457
1458 /* Everything is written out, now we dirty the pages in the file. */
1459 i_size = i_size_read(inode);
1460 for (int i = 0; i < round_up(i_size, PAGE_SIZE) / PAGE_SIZE; i++) {
1461 u64 dirty_start = i * PAGE_SIZE;
1462 u64 dirty_len = min_t(u64, dirty_start + PAGE_SIZE, i_size) - dirty_start;
1463
1464 ret = btrfs_dirty_folio(BTRFS_I(inode), page_folio(io_ctl->pages[i]),
1465 dirty_start, dirty_len, &cached_state, false);
1466 if (ret < 0)
1467 goto out_nospc;
1468 }
1469
1470 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1471 up_write(&block_group->data_rwsem);
1472 /*
1473 * Release the pages and unlock the extent, we will flush
1474 * them out later
1475 */
1476 io_ctl_drop_pages(io_ctl);
1477 io_ctl_free(io_ctl);
1478
1479 unlock_extent(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1480 &cached_state);
1481
1482 /*
1483 * at this point the pages are under IO and we're happy,
1484 * The caller is responsible for waiting on them and updating
1485 * the cache and the inode
1486 */
1487 io_ctl->entries = entries;
1488 io_ctl->bitmaps = bitmaps;
1489
1490 ret = btrfs_fdatawrite_range(BTRFS_I(inode), 0, (u64)-1);
1491 if (ret)
1492 goto out;
1493
1494 return 0;
1495
1496 out_nospc_locked:
1497 cleanup_bitmap_list(&bitmap_list);
1498 spin_unlock(&ctl->tree_lock);
1499 mutex_unlock(&ctl->cache_writeout_mutex);
1500
1501 out_nospc:
1502 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1503
1504 out_unlock:
1505 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1506 up_write(&block_group->data_rwsem);
1507
1508 out:
1509 io_ctl->inode = NULL;
1510 io_ctl_free(io_ctl);
1511 if (ret) {
1512 invalidate_inode_pages2(inode->i_mapping);
1513 BTRFS_I(inode)->generation = 0;
1514 }
1515 btrfs_update_inode(trans, BTRFS_I(inode));
1516 if (must_iput)
1517 iput(inode);
1518 return ret;
1519 }
1520
1521 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
1522 struct btrfs_block_group *block_group,
1523 struct btrfs_path *path)
1524 {
1525 struct btrfs_fs_info *fs_info = trans->fs_info;
1526 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1527 struct inode *inode;
1528 int ret = 0;
1529
1530 spin_lock(&block_group->lock);
1531 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1532 spin_unlock(&block_group->lock);
1533 return 0;
1534 }
1535 spin_unlock(&block_group->lock);
1536
1537 inode = lookup_free_space_inode(block_group, path);
1538 if (IS_ERR(inode))
1539 return 0;
1540
1541 ret = __btrfs_write_out_cache(inode, ctl, block_group,
1542 &block_group->io_ctl, trans);
1543 if (ret) {
1544 btrfs_debug(fs_info,
1545 "failed to write free space cache for block group %llu error %d",
1546 block_group->start, ret);
1547 spin_lock(&block_group->lock);
1548 block_group->disk_cache_state = BTRFS_DC_ERROR;
1549 spin_unlock(&block_group->lock);
1550
1551 block_group->io_ctl.inode = NULL;
1552 iput(inode);
1553 }
1554
1555 /*
1556 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1557 * to wait for IO and put the inode
1558 */
1559
1560 return ret;
1561 }
1562
1563 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1564 u64 offset)
1565 {
1566 ASSERT(offset >= bitmap_start);
1567 offset -= bitmap_start;
1568 return (unsigned long)(div_u64(offset, unit));
1569 }
1570
1571 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1572 {
1573 return (unsigned long)(div_u64(bytes, unit));
1574 }
1575
1576 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1577 u64 offset)
1578 {
1579 u64 bitmap_start;
1580 u64 bytes_per_bitmap;
1581
1582 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1583 bitmap_start = offset - ctl->start;
1584 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1585 bitmap_start *= bytes_per_bitmap;
1586 bitmap_start += ctl->start;
1587
1588 return bitmap_start;
1589 }
1590
1591 static int tree_insert_offset(struct btrfs_free_space_ctl *ctl,
1592 struct btrfs_free_cluster *cluster,
1593 struct btrfs_free_space *new_entry)
1594 {
1595 struct rb_root *root;
1596 struct rb_node **p;
1597 struct rb_node *parent = NULL;
1598
1599 lockdep_assert_held(&ctl->tree_lock);
1600
1601 if (cluster) {
1602 lockdep_assert_held(&cluster->lock);
1603 root = &cluster->root;
1604 } else {
1605 root = &ctl->free_space_offset;
1606 }
1607
1608 p = &root->rb_node;
1609
1610 while (*p) {
1611 struct btrfs_free_space *info;
1612
1613 parent = *p;
1614 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1615
1616 if (new_entry->offset < info->offset) {
1617 p = &(*p)->rb_left;
1618 } else if (new_entry->offset > info->offset) {
1619 p = &(*p)->rb_right;
1620 } else {
1621 /*
1622 * we could have a bitmap entry and an extent entry
1623 * share the same offset. If this is the case, we want
1624 * the extent entry to always be found first if we do a
1625 * linear search through the tree, since we want to have
1626 * the quickest allocation time, and allocating from an
1627 * extent is faster than allocating from a bitmap. So
1628 * if we're inserting a bitmap and we find an entry at
1629 * this offset, we want to go right, or after this entry
1630 * logically. If we are inserting an extent and we've
1631 * found a bitmap, we want to go left, or before
1632 * logically.
1633 */
1634 if (new_entry->bitmap) {
1635 if (info->bitmap) {
1636 WARN_ON_ONCE(1);
1637 return -EEXIST;
1638 }
1639 p = &(*p)->rb_right;
1640 } else {
1641 if (!info->bitmap) {
1642 WARN_ON_ONCE(1);
1643 return -EEXIST;
1644 }
1645 p = &(*p)->rb_left;
1646 }
1647 }
1648 }
1649
1650 rb_link_node(&new_entry->offset_index, parent, p);
1651 rb_insert_color(&new_entry->offset_index, root);
1652
1653 return 0;
1654 }
1655
1656 /*
1657 * This is a little subtle. We *only* have ->max_extent_size set if we actually
1658 * searched through the bitmap and figured out the largest ->max_extent_size,
1659 * otherwise it's 0. In the case that it's 0 we don't want to tell the
1660 * allocator the wrong thing, we want to use the actual real max_extent_size
1661 * we've found already if it's larger, or we want to use ->bytes.
1662 *
1663 * This matters because find_free_space() will skip entries who's ->bytes is
1664 * less than the required bytes. So if we didn't search down this bitmap, we
1665 * may pick some previous entry that has a smaller ->max_extent_size than we
1666 * have. For example, assume we have two entries, one that has
1667 * ->max_extent_size set to 4K and ->bytes set to 1M. A second entry hasn't set
1668 * ->max_extent_size yet, has ->bytes set to 8K and it's contiguous. We will
1669 * call into find_free_space(), and return with max_extent_size == 4K, because
1670 * that first bitmap entry had ->max_extent_size set, but the second one did
1671 * not. If instead we returned 8K we'd come in searching for 8K, and find the
1672 * 8K contiguous range.
1673 *
1674 * Consider the other case, we have 2 8K chunks in that second entry and still
1675 * don't have ->max_extent_size set. We'll return 16K, and the next time the
1676 * allocator comes in it'll fully search our second bitmap, and this time it'll
1677 * get an uptodate value of 8K as the maximum chunk size. Then we'll get the
1678 * right allocation the next loop through.
1679 */
1680 static inline u64 get_max_extent_size(const struct btrfs_free_space *entry)
1681 {
1682 if (entry->bitmap && entry->max_extent_size)
1683 return entry->max_extent_size;
1684 return entry->bytes;
1685 }
1686
1687 /*
1688 * We want the largest entry to be leftmost, so this is inverted from what you'd
1689 * normally expect.
1690 */
1691 static bool entry_less(struct rb_node *node, const struct rb_node *parent)
1692 {
1693 const struct btrfs_free_space *entry, *exist;
1694
1695 entry = rb_entry(node, struct btrfs_free_space, bytes_index);
1696 exist = rb_entry(parent, struct btrfs_free_space, bytes_index);
1697 return get_max_extent_size(exist) < get_max_extent_size(entry);
1698 }
1699
1700 /*
1701 * searches the tree for the given offset.
1702 *
1703 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1704 * want a section that has at least bytes size and comes at or after the given
1705 * offset.
1706 */
1707 static struct btrfs_free_space *
1708 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1709 u64 offset, int bitmap_only, int fuzzy)
1710 {
1711 struct rb_node *n = ctl->free_space_offset.rb_node;
1712 struct btrfs_free_space *entry = NULL, *prev = NULL;
1713
1714 lockdep_assert_held(&ctl->tree_lock);
1715
1716 /* find entry that is closest to the 'offset' */
1717 while (n) {
1718 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1719 prev = entry;
1720
1721 if (offset < entry->offset)
1722 n = n->rb_left;
1723 else if (offset > entry->offset)
1724 n = n->rb_right;
1725 else
1726 break;
1727
1728 entry = NULL;
1729 }
1730
1731 if (bitmap_only) {
1732 if (!entry)
1733 return NULL;
1734 if (entry->bitmap)
1735 return entry;
1736
1737 /*
1738 * bitmap entry and extent entry may share same offset,
1739 * in that case, bitmap entry comes after extent entry.
1740 */
1741 n = rb_next(n);
1742 if (!n)
1743 return NULL;
1744 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1745 if (entry->offset != offset)
1746 return NULL;
1747
1748 WARN_ON(!entry->bitmap);
1749 return entry;
1750 } else if (entry) {
1751 if (entry->bitmap) {
1752 /*
1753 * if previous extent entry covers the offset,
1754 * we should return it instead of the bitmap entry
1755 */
1756 n = rb_prev(&entry->offset_index);
1757 if (n) {
1758 prev = rb_entry(n, struct btrfs_free_space,
1759 offset_index);
1760 if (!prev->bitmap &&
1761 prev->offset + prev->bytes > offset)
1762 entry = prev;
1763 }
1764 }
1765 return entry;
1766 }
1767
1768 if (!prev)
1769 return NULL;
1770
1771 /* find last entry before the 'offset' */
1772 entry = prev;
1773 if (entry->offset > offset) {
1774 n = rb_prev(&entry->offset_index);
1775 if (n) {
1776 entry = rb_entry(n, struct btrfs_free_space,
1777 offset_index);
1778 ASSERT(entry->offset <= offset);
1779 } else {
1780 if (fuzzy)
1781 return entry;
1782 else
1783 return NULL;
1784 }
1785 }
1786
1787 if (entry->bitmap) {
1788 n = rb_prev(&entry->offset_index);
1789 if (n) {
1790 prev = rb_entry(n, struct btrfs_free_space,
1791 offset_index);
1792 if (!prev->bitmap &&
1793 prev->offset + prev->bytes > offset)
1794 return prev;
1795 }
1796 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1797 return entry;
1798 } else if (entry->offset + entry->bytes > offset)
1799 return entry;
1800
1801 if (!fuzzy)
1802 return NULL;
1803
1804 while (1) {
1805 n = rb_next(&entry->offset_index);
1806 if (!n)
1807 return NULL;
1808 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1809 if (entry->bitmap) {
1810 if (entry->offset + BITS_PER_BITMAP *
1811 ctl->unit > offset)
1812 break;
1813 } else {
1814 if (entry->offset + entry->bytes > offset)
1815 break;
1816 }
1817 }
1818 return entry;
1819 }
1820
1821 static inline void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1822 struct btrfs_free_space *info,
1823 bool update_stat)
1824 {
1825 lockdep_assert_held(&ctl->tree_lock);
1826
1827 rb_erase(&info->offset_index, &ctl->free_space_offset);
1828 rb_erase_cached(&info->bytes_index, &ctl->free_space_bytes);
1829 ctl->free_extents--;
1830
1831 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1832 ctl->discardable_extents[BTRFS_STAT_CURR]--;
1833 ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes;
1834 }
1835
1836 if (update_stat)
1837 ctl->free_space -= info->bytes;
1838 }
1839
1840 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1841 struct btrfs_free_space *info)
1842 {
1843 int ret = 0;
1844
1845 lockdep_assert_held(&ctl->tree_lock);
1846
1847 ASSERT(info->bytes || info->bitmap);
1848 ret = tree_insert_offset(ctl, NULL, info);
1849 if (ret)
1850 return ret;
1851
1852 rb_add_cached(&info->bytes_index, &ctl->free_space_bytes, entry_less);
1853
1854 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1855 ctl->discardable_extents[BTRFS_STAT_CURR]++;
1856 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
1857 }
1858
1859 ctl->free_space += info->bytes;
1860 ctl->free_extents++;
1861 return ret;
1862 }
1863
1864 static void relink_bitmap_entry(struct btrfs_free_space_ctl *ctl,
1865 struct btrfs_free_space *info)
1866 {
1867 ASSERT(info->bitmap);
1868
1869 /*
1870 * If our entry is empty it's because we're on a cluster and we don't
1871 * want to re-link it into our ctl bytes index.
1872 */
1873 if (RB_EMPTY_NODE(&info->bytes_index))
1874 return;
1875
1876 lockdep_assert_held(&ctl->tree_lock);
1877
1878 rb_erase_cached(&info->bytes_index, &ctl->free_space_bytes);
1879 rb_add_cached(&info->bytes_index, &ctl->free_space_bytes, entry_less);
1880 }
1881
1882 static inline void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1883 struct btrfs_free_space *info,
1884 u64 offset, u64 bytes, bool update_stat)
1885 {
1886 unsigned long start, count, end;
1887 int extent_delta = -1;
1888
1889 start = offset_to_bit(info->offset, ctl->unit, offset);
1890 count = bytes_to_bits(bytes, ctl->unit);
1891 end = start + count;
1892 ASSERT(end <= BITS_PER_BITMAP);
1893
1894 bitmap_clear(info->bitmap, start, count);
1895
1896 info->bytes -= bytes;
1897 if (info->max_extent_size > ctl->unit)
1898 info->max_extent_size = 0;
1899
1900 relink_bitmap_entry(ctl, info);
1901
1902 if (start && test_bit(start - 1, info->bitmap))
1903 extent_delta++;
1904
1905 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1906 extent_delta++;
1907
1908 info->bitmap_extents += extent_delta;
1909 if (!btrfs_free_space_trimmed(info)) {
1910 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1911 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
1912 }
1913
1914 if (update_stat)
1915 ctl->free_space -= bytes;
1916 }
1917
1918 static void btrfs_bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1919 struct btrfs_free_space *info, u64 offset,
1920 u64 bytes)
1921 {
1922 unsigned long start, count, end;
1923 int extent_delta = 1;
1924
1925 start = offset_to_bit(info->offset, ctl->unit, offset);
1926 count = bytes_to_bits(bytes, ctl->unit);
1927 end = start + count;
1928 ASSERT(end <= BITS_PER_BITMAP);
1929
1930 bitmap_set(info->bitmap, start, count);
1931
1932 /*
1933 * We set some bytes, we have no idea what the max extent size is
1934 * anymore.
1935 */
1936 info->max_extent_size = 0;
1937 info->bytes += bytes;
1938 ctl->free_space += bytes;
1939
1940 relink_bitmap_entry(ctl, info);
1941
1942 if (start && test_bit(start - 1, info->bitmap))
1943 extent_delta--;
1944
1945 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1946 extent_delta--;
1947
1948 info->bitmap_extents += extent_delta;
1949 if (!btrfs_free_space_trimmed(info)) {
1950 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1951 ctl->discardable_bytes[BTRFS_STAT_CURR] += bytes;
1952 }
1953 }
1954
1955 /*
1956 * If we can not find suitable extent, we will use bytes to record
1957 * the size of the max extent.
1958 */
1959 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1960 struct btrfs_free_space *bitmap_info, u64 *offset,
1961 u64 *bytes, bool for_alloc)
1962 {
1963 unsigned long found_bits = 0;
1964 unsigned long max_bits = 0;
1965 unsigned long bits, i;
1966 unsigned long next_zero;
1967 unsigned long extent_bits;
1968
1969 /*
1970 * Skip searching the bitmap if we don't have a contiguous section that
1971 * is large enough for this allocation.
1972 */
1973 if (for_alloc &&
1974 bitmap_info->max_extent_size &&
1975 bitmap_info->max_extent_size < *bytes) {
1976 *bytes = bitmap_info->max_extent_size;
1977 return -1;
1978 }
1979
1980 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1981 max_t(u64, *offset, bitmap_info->offset));
1982 bits = bytes_to_bits(*bytes, ctl->unit);
1983
1984 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1985 if (for_alloc && bits == 1) {
1986 found_bits = 1;
1987 break;
1988 }
1989 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1990 BITS_PER_BITMAP, i);
1991 extent_bits = next_zero - i;
1992 if (extent_bits >= bits) {
1993 found_bits = extent_bits;
1994 break;
1995 } else if (extent_bits > max_bits) {
1996 max_bits = extent_bits;
1997 }
1998 i = next_zero;
1999 }
2000
2001 if (found_bits) {
2002 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
2003 *bytes = (u64)(found_bits) * ctl->unit;
2004 return 0;
2005 }
2006
2007 *bytes = (u64)(max_bits) * ctl->unit;
2008 bitmap_info->max_extent_size = *bytes;
2009 relink_bitmap_entry(ctl, bitmap_info);
2010 return -1;
2011 }
2012
2013 /* Cache the size of the max extent in bytes */
2014 static struct btrfs_free_space *
2015 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
2016 unsigned long align, u64 *max_extent_size, bool use_bytes_index)
2017 {
2018 struct btrfs_free_space *entry;
2019 struct rb_node *node;
2020 u64 tmp;
2021 u64 align_off;
2022 int ret;
2023
2024 if (!ctl->free_space_offset.rb_node)
2025 goto out;
2026 again:
2027 if (use_bytes_index) {
2028 node = rb_first_cached(&ctl->free_space_bytes);
2029 } else {
2030 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset),
2031 0, 1);
2032 if (!entry)
2033 goto out;
2034 node = &entry->offset_index;
2035 }
2036
2037 for (; node; node = rb_next(node)) {
2038 if (use_bytes_index)
2039 entry = rb_entry(node, struct btrfs_free_space,
2040 bytes_index);
2041 else
2042 entry = rb_entry(node, struct btrfs_free_space,
2043 offset_index);
2044
2045 /*
2046 * If we are using the bytes index then all subsequent entries
2047 * in this tree are going to be < bytes, so simply set the max
2048 * extent size and exit the loop.
2049 *
2050 * If we're using the offset index then we need to keep going
2051 * through the rest of the tree.
2052 */
2053 if (entry->bytes < *bytes) {
2054 *max_extent_size = max(get_max_extent_size(entry),
2055 *max_extent_size);
2056 if (use_bytes_index)
2057 break;
2058 continue;
2059 }
2060
2061 /* make sure the space returned is big enough
2062 * to match our requested alignment
2063 */
2064 if (*bytes >= align) {
2065 tmp = entry->offset - ctl->start + align - 1;
2066 tmp = div64_u64(tmp, align);
2067 tmp = tmp * align + ctl->start;
2068 align_off = tmp - entry->offset;
2069 } else {
2070 align_off = 0;
2071 tmp = entry->offset;
2072 }
2073
2074 /*
2075 * We don't break here if we're using the bytes index because we
2076 * may have another entry that has the correct alignment that is
2077 * the right size, so we don't want to miss that possibility.
2078 * At worst this adds another loop through the logic, but if we
2079 * broke here we could prematurely ENOSPC.
2080 */
2081 if (entry->bytes < *bytes + align_off) {
2082 *max_extent_size = max(get_max_extent_size(entry),
2083 *max_extent_size);
2084 continue;
2085 }
2086
2087 if (entry->bitmap) {
2088 struct rb_node *old_next = rb_next(node);
2089 u64 size = *bytes;
2090
2091 ret = search_bitmap(ctl, entry, &tmp, &size, true);
2092 if (!ret) {
2093 *offset = tmp;
2094 *bytes = size;
2095 return entry;
2096 } else {
2097 *max_extent_size =
2098 max(get_max_extent_size(entry),
2099 *max_extent_size);
2100 }
2101
2102 /*
2103 * The bitmap may have gotten re-arranged in the space
2104 * index here because the max_extent_size may have been
2105 * updated. Start from the beginning again if this
2106 * happened.
2107 */
2108 if (use_bytes_index && old_next != rb_next(node))
2109 goto again;
2110 continue;
2111 }
2112
2113 *offset = tmp;
2114 *bytes = entry->bytes - align_off;
2115 return entry;
2116 }
2117 out:
2118 return NULL;
2119 }
2120
2121 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
2122 struct btrfs_free_space *info, u64 offset)
2123 {
2124 info->offset = offset_to_bitmap(ctl, offset);
2125 info->bytes = 0;
2126 info->bitmap_extents = 0;
2127 INIT_LIST_HEAD(&info->list);
2128 link_free_space(ctl, info);
2129 ctl->total_bitmaps++;
2130 recalculate_thresholds(ctl);
2131 }
2132
2133 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
2134 struct btrfs_free_space *bitmap_info)
2135 {
2136 /*
2137 * Normally when this is called, the bitmap is completely empty. However,
2138 * if we are blowing up the free space cache for one reason or another
2139 * via __btrfs_remove_free_space_cache(), then it may not be freed and
2140 * we may leave stats on the table.
2141 */
2142 if (bitmap_info->bytes && !btrfs_free_space_trimmed(bitmap_info)) {
2143 ctl->discardable_extents[BTRFS_STAT_CURR] -=
2144 bitmap_info->bitmap_extents;
2145 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bitmap_info->bytes;
2146
2147 }
2148 unlink_free_space(ctl, bitmap_info, true);
2149 kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
2150 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
2151 ctl->total_bitmaps--;
2152 recalculate_thresholds(ctl);
2153 }
2154
2155 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
2156 struct btrfs_free_space *bitmap_info,
2157 u64 *offset, u64 *bytes)
2158 {
2159 u64 end;
2160 u64 search_start, search_bytes;
2161 int ret;
2162
2163 again:
2164 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
2165
2166 /*
2167 * We need to search for bits in this bitmap. We could only cover some
2168 * of the extent in this bitmap thanks to how we add space, so we need
2169 * to search for as much as it as we can and clear that amount, and then
2170 * go searching for the next bit.
2171 */
2172 search_start = *offset;
2173 search_bytes = ctl->unit;
2174 search_bytes = min(search_bytes, end - search_start + 1);
2175 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
2176 false);
2177 if (ret < 0 || search_start != *offset)
2178 return -EINVAL;
2179
2180 /* We may have found more bits than what we need */
2181 search_bytes = min(search_bytes, *bytes);
2182
2183 /* Cannot clear past the end of the bitmap */
2184 search_bytes = min(search_bytes, end - search_start + 1);
2185
2186 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes, true);
2187 *offset += search_bytes;
2188 *bytes -= search_bytes;
2189
2190 if (*bytes) {
2191 struct rb_node *next = rb_next(&bitmap_info->offset_index);
2192 if (!bitmap_info->bytes)
2193 free_bitmap(ctl, bitmap_info);
2194
2195 /*
2196 * no entry after this bitmap, but we still have bytes to
2197 * remove, so something has gone wrong.
2198 */
2199 if (!next)
2200 return -EINVAL;
2201
2202 bitmap_info = rb_entry(next, struct btrfs_free_space,
2203 offset_index);
2204
2205 /*
2206 * if the next entry isn't a bitmap we need to return to let the
2207 * extent stuff do its work.
2208 */
2209 if (!bitmap_info->bitmap)
2210 return -EAGAIN;
2211
2212 /*
2213 * Ok the next item is a bitmap, but it may not actually hold
2214 * the information for the rest of this free space stuff, so
2215 * look for it, and if we don't find it return so we can try
2216 * everything over again.
2217 */
2218 search_start = *offset;
2219 search_bytes = ctl->unit;
2220 ret = search_bitmap(ctl, bitmap_info, &search_start,
2221 &search_bytes, false);
2222 if (ret < 0 || search_start != *offset)
2223 return -EAGAIN;
2224
2225 goto again;
2226 } else if (!bitmap_info->bytes)
2227 free_bitmap(ctl, bitmap_info);
2228
2229 return 0;
2230 }
2231
2232 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
2233 struct btrfs_free_space *info, u64 offset,
2234 u64 bytes, enum btrfs_trim_state trim_state)
2235 {
2236 u64 bytes_to_set = 0;
2237 u64 end;
2238
2239 /*
2240 * This is a tradeoff to make bitmap trim state minimal. We mark the
2241 * whole bitmap untrimmed if at any point we add untrimmed regions.
2242 */
2243 if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) {
2244 if (btrfs_free_space_trimmed(info)) {
2245 ctl->discardable_extents[BTRFS_STAT_CURR] +=
2246 info->bitmap_extents;
2247 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
2248 }
2249 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2250 }
2251
2252 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
2253
2254 bytes_to_set = min(end - offset, bytes);
2255
2256 btrfs_bitmap_set_bits(ctl, info, offset, bytes_to_set);
2257
2258 return bytes_to_set;
2259
2260 }
2261
2262 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
2263 struct btrfs_free_space *info)
2264 {
2265 struct btrfs_block_group *block_group = ctl->block_group;
2266 struct btrfs_fs_info *fs_info = block_group->fs_info;
2267 bool forced = false;
2268
2269 #ifdef CONFIG_BTRFS_DEBUG
2270 if (btrfs_should_fragment_free_space(block_group))
2271 forced = true;
2272 #endif
2273
2274 /* This is a way to reclaim large regions from the bitmaps. */
2275 if (!forced && info->bytes >= FORCE_EXTENT_THRESHOLD)
2276 return false;
2277
2278 /*
2279 * If we are below the extents threshold then we can add this as an
2280 * extent, and don't have to deal with the bitmap
2281 */
2282 if (!forced && ctl->free_extents < ctl->extents_thresh) {
2283 /*
2284 * If this block group has some small extents we don't want to
2285 * use up all of our free slots in the cache with them, we want
2286 * to reserve them to larger extents, however if we have plenty
2287 * of cache left then go ahead an dadd them, no sense in adding
2288 * the overhead of a bitmap if we don't have to.
2289 */
2290 if (info->bytes <= fs_info->sectorsize * 8) {
2291 if (ctl->free_extents * 3 <= ctl->extents_thresh)
2292 return false;
2293 } else {
2294 return false;
2295 }
2296 }
2297
2298 /*
2299 * The original block groups from mkfs can be really small, like 8
2300 * megabytes, so don't bother with a bitmap for those entries. However
2301 * some block groups can be smaller than what a bitmap would cover but
2302 * are still large enough that they could overflow the 32k memory limit,
2303 * so allow those block groups to still be allowed to have a bitmap
2304 * entry.
2305 */
2306 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->length)
2307 return false;
2308
2309 return true;
2310 }
2311
2312 static const struct btrfs_free_space_op free_space_op = {
2313 .use_bitmap = use_bitmap,
2314 };
2315
2316 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2317 struct btrfs_free_space *info)
2318 {
2319 struct btrfs_free_space *bitmap_info;
2320 struct btrfs_block_group *block_group = NULL;
2321 int added = 0;
2322 u64 bytes, offset, bytes_added;
2323 enum btrfs_trim_state trim_state;
2324 int ret;
2325
2326 bytes = info->bytes;
2327 offset = info->offset;
2328 trim_state = info->trim_state;
2329
2330 if (!ctl->op->use_bitmap(ctl, info))
2331 return 0;
2332
2333 if (ctl->op == &free_space_op)
2334 block_group = ctl->block_group;
2335 again:
2336 /*
2337 * Since we link bitmaps right into the cluster we need to see if we
2338 * have a cluster here, and if so and it has our bitmap we need to add
2339 * the free space to that bitmap.
2340 */
2341 if (block_group && !list_empty(&block_group->cluster_list)) {
2342 struct btrfs_free_cluster *cluster;
2343 struct rb_node *node;
2344 struct btrfs_free_space *entry;
2345
2346 cluster = list_entry(block_group->cluster_list.next,
2347 struct btrfs_free_cluster,
2348 block_group_list);
2349 spin_lock(&cluster->lock);
2350 node = rb_first(&cluster->root);
2351 if (!node) {
2352 spin_unlock(&cluster->lock);
2353 goto no_cluster_bitmap;
2354 }
2355
2356 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2357 if (!entry->bitmap) {
2358 spin_unlock(&cluster->lock);
2359 goto no_cluster_bitmap;
2360 }
2361
2362 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2363 bytes_added = add_bytes_to_bitmap(ctl, entry, offset,
2364 bytes, trim_state);
2365 bytes -= bytes_added;
2366 offset += bytes_added;
2367 }
2368 spin_unlock(&cluster->lock);
2369 if (!bytes) {
2370 ret = 1;
2371 goto out;
2372 }
2373 }
2374
2375 no_cluster_bitmap:
2376 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2377 1, 0);
2378 if (!bitmap_info) {
2379 ASSERT(added == 0);
2380 goto new_bitmap;
2381 }
2382
2383 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
2384 trim_state);
2385 bytes -= bytes_added;
2386 offset += bytes_added;
2387 added = 0;
2388
2389 if (!bytes) {
2390 ret = 1;
2391 goto out;
2392 } else
2393 goto again;
2394
2395 new_bitmap:
2396 if (info && info->bitmap) {
2397 add_new_bitmap(ctl, info, offset);
2398 added = 1;
2399 info = NULL;
2400 goto again;
2401 } else {
2402 spin_unlock(&ctl->tree_lock);
2403
2404 /* no pre-allocated info, allocate a new one */
2405 if (!info) {
2406 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2407 GFP_NOFS);
2408 if (!info) {
2409 spin_lock(&ctl->tree_lock);
2410 ret = -ENOMEM;
2411 goto out;
2412 }
2413 }
2414
2415 /* allocate the bitmap */
2416 info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
2417 GFP_NOFS);
2418 info->trim_state = BTRFS_TRIM_STATE_TRIMMED;
2419 spin_lock(&ctl->tree_lock);
2420 if (!info->bitmap) {
2421 ret = -ENOMEM;
2422 goto out;
2423 }
2424 goto again;
2425 }
2426
2427 out:
2428 if (info) {
2429 if (info->bitmap)
2430 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2431 info->bitmap);
2432 kmem_cache_free(btrfs_free_space_cachep, info);
2433 }
2434
2435 return ret;
2436 }
2437
2438 /*
2439 * Free space merging rules:
2440 * 1) Merge trimmed areas together
2441 * 2) Let untrimmed areas coalesce with trimmed areas
2442 * 3) Always pull neighboring regions from bitmaps
2443 *
2444 * The above rules are for when we merge free space based on btrfs_trim_state.
2445 * Rules 2 and 3 are subtle because they are suboptimal, but are done for the
2446 * same reason: to promote larger extent regions which makes life easier for
2447 * find_free_extent(). Rule 2 enables coalescing based on the common path
2448 * being returning free space from btrfs_finish_extent_commit(). So when free
2449 * space is trimmed, it will prevent aggregating trimmed new region and
2450 * untrimmed regions in the rb_tree. Rule 3 is purely to obtain larger extents
2451 * and provide find_free_extent() with the largest extents possible hoping for
2452 * the reuse path.
2453 */
2454 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2455 struct btrfs_free_space *info, bool update_stat)
2456 {
2457 struct btrfs_free_space *left_info = NULL;
2458 struct btrfs_free_space *right_info;
2459 bool merged = false;
2460 u64 offset = info->offset;
2461 u64 bytes = info->bytes;
2462 const bool is_trimmed = btrfs_free_space_trimmed(info);
2463 struct rb_node *right_prev = NULL;
2464
2465 /*
2466 * first we want to see if there is free space adjacent to the range we
2467 * are adding, if there is remove that struct and add a new one to
2468 * cover the entire range
2469 */
2470 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2471 if (right_info)
2472 right_prev = rb_prev(&right_info->offset_index);
2473
2474 if (right_prev)
2475 left_info = rb_entry(right_prev, struct btrfs_free_space, offset_index);
2476 else if (!right_info)
2477 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2478
2479 /* See try_merge_free_space() comment. */
2480 if (right_info && !right_info->bitmap &&
2481 (!is_trimmed || btrfs_free_space_trimmed(right_info))) {
2482 unlink_free_space(ctl, right_info, update_stat);
2483 info->bytes += right_info->bytes;
2484 kmem_cache_free(btrfs_free_space_cachep, right_info);
2485 merged = true;
2486 }
2487
2488 /* See try_merge_free_space() comment. */
2489 if (left_info && !left_info->bitmap &&
2490 left_info->offset + left_info->bytes == offset &&
2491 (!is_trimmed || btrfs_free_space_trimmed(left_info))) {
2492 unlink_free_space(ctl, left_info, update_stat);
2493 info->offset = left_info->offset;
2494 info->bytes += left_info->bytes;
2495 kmem_cache_free(btrfs_free_space_cachep, left_info);
2496 merged = true;
2497 }
2498
2499 return merged;
2500 }
2501
2502 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2503 struct btrfs_free_space *info,
2504 bool update_stat)
2505 {
2506 struct btrfs_free_space *bitmap;
2507 unsigned long i;
2508 unsigned long j;
2509 const u64 end = info->offset + info->bytes;
2510 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2511 u64 bytes;
2512
2513 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2514 if (!bitmap)
2515 return false;
2516
2517 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2518 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2519 if (j == i)
2520 return false;
2521 bytes = (j - i) * ctl->unit;
2522 info->bytes += bytes;
2523
2524 /* See try_merge_free_space() comment. */
2525 if (!btrfs_free_space_trimmed(bitmap))
2526 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2527
2528 bitmap_clear_bits(ctl, bitmap, end, bytes, update_stat);
2529
2530 if (!bitmap->bytes)
2531 free_bitmap(ctl, bitmap);
2532
2533 return true;
2534 }
2535
2536 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2537 struct btrfs_free_space *info,
2538 bool update_stat)
2539 {
2540 struct btrfs_free_space *bitmap;
2541 u64 bitmap_offset;
2542 unsigned long i;
2543 unsigned long j;
2544 unsigned long prev_j;
2545 u64 bytes;
2546
2547 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2548 /* If we're on a boundary, try the previous logical bitmap. */
2549 if (bitmap_offset == info->offset) {
2550 if (info->offset == 0)
2551 return false;
2552 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2553 }
2554
2555 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2556 if (!bitmap)
2557 return false;
2558
2559 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2560 j = 0;
2561 prev_j = (unsigned long)-1;
2562 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2563 if (j > i)
2564 break;
2565 prev_j = j;
2566 }
2567 if (prev_j == i)
2568 return false;
2569
2570 if (prev_j == (unsigned long)-1)
2571 bytes = (i + 1) * ctl->unit;
2572 else
2573 bytes = (i - prev_j) * ctl->unit;
2574
2575 info->offset -= bytes;
2576 info->bytes += bytes;
2577
2578 /* See try_merge_free_space() comment. */
2579 if (!btrfs_free_space_trimmed(bitmap))
2580 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2581
2582 bitmap_clear_bits(ctl, bitmap, info->offset, bytes, update_stat);
2583
2584 if (!bitmap->bytes)
2585 free_bitmap(ctl, bitmap);
2586
2587 return true;
2588 }
2589
2590 /*
2591 * We prefer always to allocate from extent entries, both for clustered and
2592 * non-clustered allocation requests. So when attempting to add a new extent
2593 * entry, try to see if there's adjacent free space in bitmap entries, and if
2594 * there is, migrate that space from the bitmaps to the extent.
2595 * Like this we get better chances of satisfying space allocation requests
2596 * because we attempt to satisfy them based on a single cache entry, and never
2597 * on 2 or more entries - even if the entries represent a contiguous free space
2598 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2599 * ends).
2600 */
2601 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2602 struct btrfs_free_space *info,
2603 bool update_stat)
2604 {
2605 /*
2606 * Only work with disconnected entries, as we can change their offset,
2607 * and must be extent entries.
2608 */
2609 ASSERT(!info->bitmap);
2610 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2611
2612 if (ctl->total_bitmaps > 0) {
2613 bool stole_end;
2614 bool stole_front = false;
2615
2616 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2617 if (ctl->total_bitmaps > 0)
2618 stole_front = steal_from_bitmap_to_front(ctl, info,
2619 update_stat);
2620
2621 if (stole_end || stole_front)
2622 try_merge_free_space(ctl, info, update_stat);
2623 }
2624 }
2625
2626 static int __btrfs_add_free_space(struct btrfs_block_group *block_group,
2627 u64 offset, u64 bytes,
2628 enum btrfs_trim_state trim_state)
2629 {
2630 struct btrfs_fs_info *fs_info = block_group->fs_info;
2631 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2632 struct btrfs_free_space *info;
2633 int ret = 0;
2634 u64 filter_bytes = bytes;
2635
2636 ASSERT(!btrfs_is_zoned(fs_info));
2637
2638 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2639 if (!info)
2640 return -ENOMEM;
2641
2642 info->offset = offset;
2643 info->bytes = bytes;
2644 info->trim_state = trim_state;
2645 RB_CLEAR_NODE(&info->offset_index);
2646 RB_CLEAR_NODE(&info->bytes_index);
2647
2648 spin_lock(&ctl->tree_lock);
2649
2650 if (try_merge_free_space(ctl, info, true))
2651 goto link;
2652
2653 /*
2654 * There was no extent directly to the left or right of this new
2655 * extent then we know we're going to have to allocate a new extent, so
2656 * before we do that see if we need to drop this into a bitmap
2657 */
2658 ret = insert_into_bitmap(ctl, info);
2659 if (ret < 0) {
2660 goto out;
2661 } else if (ret) {
2662 ret = 0;
2663 goto out;
2664 }
2665 link:
2666 /*
2667 * Only steal free space from adjacent bitmaps if we're sure we're not
2668 * going to add the new free space to existing bitmap entries - because
2669 * that would mean unnecessary work that would be reverted. Therefore
2670 * attempt to steal space from bitmaps if we're adding an extent entry.
2671 */
2672 steal_from_bitmap(ctl, info, true);
2673
2674 filter_bytes = max(filter_bytes, info->bytes);
2675
2676 ret = link_free_space(ctl, info);
2677 if (ret)
2678 kmem_cache_free(btrfs_free_space_cachep, info);
2679 out:
2680 btrfs_discard_update_discardable(block_group);
2681 spin_unlock(&ctl->tree_lock);
2682
2683 if (ret) {
2684 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2685 ASSERT(ret != -EEXIST);
2686 }
2687
2688 if (trim_state != BTRFS_TRIM_STATE_TRIMMED) {
2689 btrfs_discard_check_filter(block_group, filter_bytes);
2690 btrfs_discard_queue_work(&fs_info->discard_ctl, block_group);
2691 }
2692
2693 return ret;
2694 }
2695
2696 static int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
2697 u64 bytenr, u64 size, bool used)
2698 {
2699 struct btrfs_space_info *sinfo = block_group->space_info;
2700 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2701 u64 offset = bytenr - block_group->start;
2702 u64 to_free, to_unusable;
2703 int bg_reclaim_threshold = 0;
2704 bool initial;
2705 u64 reclaimable_unusable;
2706
2707 spin_lock(&block_group->lock);
2708
2709 initial = ((size == block_group->length) && (block_group->alloc_offset == 0));
2710 WARN_ON(!initial && offset + size > block_group->zone_capacity);
2711 if (!initial)
2712 bg_reclaim_threshold = READ_ONCE(sinfo->bg_reclaim_threshold);
2713
2714 if (!used)
2715 to_free = size;
2716 else if (initial)
2717 to_free = block_group->zone_capacity;
2718 else if (offset >= block_group->alloc_offset)
2719 to_free = size;
2720 else if (offset + size <= block_group->alloc_offset)
2721 to_free = 0;
2722 else
2723 to_free = offset + size - block_group->alloc_offset;
2724 to_unusable = size - to_free;
2725
2726 spin_lock(&ctl->tree_lock);
2727 ctl->free_space += to_free;
2728 spin_unlock(&ctl->tree_lock);
2729 /*
2730 * If the block group is read-only, we should account freed space into
2731 * bytes_readonly.
2732 */
2733 if (!block_group->ro) {
2734 block_group->zone_unusable += to_unusable;
2735 WARN_ON(block_group->zone_unusable > block_group->length);
2736 }
2737 if (!used) {
2738 block_group->alloc_offset -= size;
2739 }
2740
2741 reclaimable_unusable = block_group->zone_unusable -
2742 (block_group->length - block_group->zone_capacity);
2743 /* All the region is now unusable. Mark it as unused and reclaim */
2744 if (block_group->zone_unusable == block_group->length) {
2745 btrfs_mark_bg_unused(block_group);
2746 } else if (bg_reclaim_threshold &&
2747 reclaimable_unusable >=
2748 mult_perc(block_group->zone_capacity, bg_reclaim_threshold)) {
2749 btrfs_mark_bg_to_reclaim(block_group);
2750 }
2751
2752 spin_unlock(&block_group->lock);
2753
2754 return 0;
2755 }
2756
2757 int btrfs_add_free_space(struct btrfs_block_group *block_group,
2758 u64 bytenr, u64 size)
2759 {
2760 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2761
2762 if (btrfs_is_zoned(block_group->fs_info))
2763 return __btrfs_add_free_space_zoned(block_group, bytenr, size,
2764 true);
2765
2766 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
2767 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2768
2769 return __btrfs_add_free_space(block_group, bytenr, size, trim_state);
2770 }
2771
2772 int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
2773 u64 bytenr, u64 size)
2774 {
2775 if (btrfs_is_zoned(block_group->fs_info))
2776 return __btrfs_add_free_space_zoned(block_group, bytenr, size,
2777 false);
2778
2779 return btrfs_add_free_space(block_group, bytenr, size);
2780 }
2781
2782 /*
2783 * This is a subtle distinction because when adding free space back in general,
2784 * we want it to be added as untrimmed for async. But in the case where we add
2785 * it on loading of a block group, we want to consider it trimmed.
2786 */
2787 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
2788 u64 bytenr, u64 size)
2789 {
2790 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2791
2792 if (btrfs_is_zoned(block_group->fs_info))
2793 return __btrfs_add_free_space_zoned(block_group, bytenr, size,
2794 true);
2795
2796 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) ||
2797 btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
2798 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2799
2800 return __btrfs_add_free_space(block_group, bytenr, size, trim_state);
2801 }
2802
2803 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
2804 u64 offset, u64 bytes)
2805 {
2806 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2807 struct btrfs_free_space *info;
2808 int ret;
2809 bool re_search = false;
2810
2811 if (btrfs_is_zoned(block_group->fs_info)) {
2812 /*
2813 * This can happen with conventional zones when replaying log.
2814 * Since the allocation info of tree-log nodes are not recorded
2815 * to the extent-tree, calculate_alloc_pointer() failed to
2816 * advance the allocation pointer after last allocated tree log
2817 * node blocks.
2818 *
2819 * This function is called from
2820 * btrfs_pin_extent_for_log_replay() when replaying the log.
2821 * Advance the pointer not to overwrite the tree-log nodes.
2822 */
2823 if (block_group->start + block_group->alloc_offset <
2824 offset + bytes) {
2825 block_group->alloc_offset =
2826 offset + bytes - block_group->start;
2827 }
2828 return 0;
2829 }
2830
2831 spin_lock(&ctl->tree_lock);
2832
2833 again:
2834 ret = 0;
2835 if (!bytes)
2836 goto out_lock;
2837
2838 info = tree_search_offset(ctl, offset, 0, 0);
2839 if (!info) {
2840 /*
2841 * oops didn't find an extent that matched the space we wanted
2842 * to remove, look for a bitmap instead
2843 */
2844 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2845 1, 0);
2846 if (!info) {
2847 /*
2848 * If we found a partial bit of our free space in a
2849 * bitmap but then couldn't find the other part this may
2850 * be a problem, so WARN about it.
2851 */
2852 WARN_ON(re_search);
2853 goto out_lock;
2854 }
2855 }
2856
2857 re_search = false;
2858 if (!info->bitmap) {
2859 unlink_free_space(ctl, info, true);
2860 if (offset == info->offset) {
2861 u64 to_free = min(bytes, info->bytes);
2862
2863 info->bytes -= to_free;
2864 info->offset += to_free;
2865 if (info->bytes) {
2866 ret = link_free_space(ctl, info);
2867 WARN_ON(ret);
2868 } else {
2869 kmem_cache_free(btrfs_free_space_cachep, info);
2870 }
2871
2872 offset += to_free;
2873 bytes -= to_free;
2874 goto again;
2875 } else {
2876 u64 old_end = info->bytes + info->offset;
2877
2878 info->bytes = offset - info->offset;
2879 ret = link_free_space(ctl, info);
2880 WARN_ON(ret);
2881 if (ret)
2882 goto out_lock;
2883
2884 /* Not enough bytes in this entry to satisfy us */
2885 if (old_end < offset + bytes) {
2886 bytes -= old_end - offset;
2887 offset = old_end;
2888 goto again;
2889 } else if (old_end == offset + bytes) {
2890 /* all done */
2891 goto out_lock;
2892 }
2893 spin_unlock(&ctl->tree_lock);
2894
2895 ret = __btrfs_add_free_space(block_group,
2896 offset + bytes,
2897 old_end - (offset + bytes),
2898 info->trim_state);
2899 WARN_ON(ret);
2900 goto out;
2901 }
2902 }
2903
2904 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2905 if (ret == -EAGAIN) {
2906 re_search = true;
2907 goto again;
2908 }
2909 out_lock:
2910 btrfs_discard_update_discardable(block_group);
2911 spin_unlock(&ctl->tree_lock);
2912 out:
2913 return ret;
2914 }
2915
2916 void btrfs_dump_free_space(struct btrfs_block_group *block_group,
2917 u64 bytes)
2918 {
2919 struct btrfs_fs_info *fs_info = block_group->fs_info;
2920 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2921 struct btrfs_free_space *info;
2922 struct rb_node *n;
2923 int count = 0;
2924
2925 /*
2926 * Zoned btrfs does not use free space tree and cluster. Just print
2927 * out the free space after the allocation offset.
2928 */
2929 if (btrfs_is_zoned(fs_info)) {
2930 btrfs_info(fs_info, "free space %llu active %d",
2931 block_group->zone_capacity - block_group->alloc_offset,
2932 test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
2933 &block_group->runtime_flags));
2934 return;
2935 }
2936
2937 spin_lock(&ctl->tree_lock);
2938 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2939 info = rb_entry(n, struct btrfs_free_space, offset_index);
2940 if (info->bytes >= bytes && !block_group->ro)
2941 count++;
2942 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2943 info->offset, info->bytes, str_yes_no(info->bitmap));
2944 }
2945 spin_unlock(&ctl->tree_lock);
2946 btrfs_info(fs_info, "block group has cluster?: %s",
2947 str_no_yes(list_empty(&block_group->cluster_list)));
2948 btrfs_info(fs_info,
2949 "%d free space entries at or bigger than %llu bytes",
2950 count, bytes);
2951 }
2952
2953 void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group,
2954 struct btrfs_free_space_ctl *ctl)
2955 {
2956 struct btrfs_fs_info *fs_info = block_group->fs_info;
2957
2958 spin_lock_init(&ctl->tree_lock);
2959 ctl->unit = fs_info->sectorsize;
2960 ctl->start = block_group->start;
2961 ctl->block_group = block_group;
2962 ctl->op = &free_space_op;
2963 ctl->free_space_bytes = RB_ROOT_CACHED;
2964 INIT_LIST_HEAD(&ctl->trimming_ranges);
2965 mutex_init(&ctl->cache_writeout_mutex);
2966
2967 /*
2968 * we only want to have 32k of ram per block group for keeping
2969 * track of free space, and if we pass 1/2 of that we want to
2970 * start converting things over to using bitmaps
2971 */
2972 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2973 }
2974
2975 /*
2976 * for a given cluster, put all of its extents back into the free
2977 * space cache. If the block group passed doesn't match the block group
2978 * pointed to by the cluster, someone else raced in and freed the
2979 * cluster already. In that case, we just return without changing anything
2980 */
2981 static void __btrfs_return_cluster_to_free_space(
2982 struct btrfs_block_group *block_group,
2983 struct btrfs_free_cluster *cluster)
2984 {
2985 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2986 struct rb_node *node;
2987
2988 lockdep_assert_held(&ctl->tree_lock);
2989
2990 spin_lock(&cluster->lock);
2991 if (cluster->block_group != block_group) {
2992 spin_unlock(&cluster->lock);
2993 return;
2994 }
2995
2996 cluster->block_group = NULL;
2997 cluster->window_start = 0;
2998 list_del_init(&cluster->block_group_list);
2999
3000 node = rb_first(&cluster->root);
3001 while (node) {
3002 struct btrfs_free_space *entry;
3003
3004 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3005 node = rb_next(&entry->offset_index);
3006 rb_erase(&entry->offset_index, &cluster->root);
3007 RB_CLEAR_NODE(&entry->offset_index);
3008
3009 if (!entry->bitmap) {
3010 /* Merging treats extents as if they were new */
3011 if (!btrfs_free_space_trimmed(entry)) {
3012 ctl->discardable_extents[BTRFS_STAT_CURR]--;
3013 ctl->discardable_bytes[BTRFS_STAT_CURR] -=
3014 entry->bytes;
3015 }
3016
3017 try_merge_free_space(ctl, entry, false);
3018 steal_from_bitmap(ctl, entry, false);
3019
3020 /* As we insert directly, update these statistics */
3021 if (!btrfs_free_space_trimmed(entry)) {
3022 ctl->discardable_extents[BTRFS_STAT_CURR]++;
3023 ctl->discardable_bytes[BTRFS_STAT_CURR] +=
3024 entry->bytes;
3025 }
3026 }
3027 tree_insert_offset(ctl, NULL, entry);
3028 rb_add_cached(&entry->bytes_index, &ctl->free_space_bytes,
3029 entry_less);
3030 }
3031 cluster->root = RB_ROOT;
3032 spin_unlock(&cluster->lock);
3033 btrfs_put_block_group(block_group);
3034 }
3035
3036 void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group)
3037 {
3038 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3039 struct btrfs_free_cluster *cluster;
3040 struct list_head *head;
3041
3042 spin_lock(&ctl->tree_lock);
3043 while ((head = block_group->cluster_list.next) !=
3044 &block_group->cluster_list) {
3045 cluster = list_entry(head, struct btrfs_free_cluster,
3046 block_group_list);
3047
3048 WARN_ON(cluster->block_group != block_group);
3049 __btrfs_return_cluster_to_free_space(block_group, cluster);
3050
3051 cond_resched_lock(&ctl->tree_lock);
3052 }
3053 __btrfs_remove_free_space_cache(ctl);
3054 btrfs_discard_update_discardable(block_group);
3055 spin_unlock(&ctl->tree_lock);
3056
3057 }
3058
3059 /*
3060 * Walk @block_group's free space rb_tree to determine if everything is trimmed.
3061 */
3062 bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group)
3063 {
3064 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3065 struct btrfs_free_space *info;
3066 struct rb_node *node;
3067 bool ret = true;
3068
3069 spin_lock(&ctl->tree_lock);
3070 node = rb_first(&ctl->free_space_offset);
3071
3072 while (node) {
3073 info = rb_entry(node, struct btrfs_free_space, offset_index);
3074
3075 if (!btrfs_free_space_trimmed(info)) {
3076 ret = false;
3077 break;
3078 }
3079
3080 node = rb_next(node);
3081 }
3082
3083 spin_unlock(&ctl->tree_lock);
3084 return ret;
3085 }
3086
3087 u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
3088 u64 offset, u64 bytes, u64 empty_size,
3089 u64 *max_extent_size)
3090 {
3091 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3092 struct btrfs_discard_ctl *discard_ctl =
3093 &block_group->fs_info->discard_ctl;
3094 struct btrfs_free_space *entry = NULL;
3095 u64 bytes_search = bytes + empty_size;
3096 u64 ret = 0;
3097 u64 align_gap = 0;
3098 u64 align_gap_len = 0;
3099 enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3100 bool use_bytes_index = (offset == block_group->start);
3101
3102 ASSERT(!btrfs_is_zoned(block_group->fs_info));
3103
3104 spin_lock(&ctl->tree_lock);
3105 entry = find_free_space(ctl, &offset, &bytes_search,
3106 block_group->full_stripe_len, max_extent_size,
3107 use_bytes_index);
3108 if (!entry)
3109 goto out;
3110
3111 ret = offset;
3112 if (entry->bitmap) {
3113 bitmap_clear_bits(ctl, entry, offset, bytes, true);
3114
3115 if (!btrfs_free_space_trimmed(entry))
3116 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3117
3118 if (!entry->bytes)
3119 free_bitmap(ctl, entry);
3120 } else {
3121 unlink_free_space(ctl, entry, true);
3122 align_gap_len = offset - entry->offset;
3123 align_gap = entry->offset;
3124 align_gap_trim_state = entry->trim_state;
3125
3126 if (!btrfs_free_space_trimmed(entry))
3127 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3128
3129 entry->offset = offset + bytes;
3130 WARN_ON(entry->bytes < bytes + align_gap_len);
3131
3132 entry->bytes -= bytes + align_gap_len;
3133 if (!entry->bytes)
3134 kmem_cache_free(btrfs_free_space_cachep, entry);
3135 else
3136 link_free_space(ctl, entry);
3137 }
3138 out:
3139 btrfs_discard_update_discardable(block_group);
3140 spin_unlock(&ctl->tree_lock);
3141
3142 if (align_gap_len)
3143 __btrfs_add_free_space(block_group, align_gap, align_gap_len,
3144 align_gap_trim_state);
3145 return ret;
3146 }
3147
3148 /*
3149 * given a cluster, put all of its extents back into the free space
3150 * cache. If a block group is passed, this function will only free
3151 * a cluster that belongs to the passed block group.
3152 *
3153 * Otherwise, it'll get a reference on the block group pointed to by the
3154 * cluster and remove the cluster from it.
3155 */
3156 void btrfs_return_cluster_to_free_space(
3157 struct btrfs_block_group *block_group,
3158 struct btrfs_free_cluster *cluster)
3159 {
3160 struct btrfs_free_space_ctl *ctl;
3161
3162 /* first, get a safe pointer to the block group */
3163 spin_lock(&cluster->lock);
3164 if (!block_group) {
3165 block_group = cluster->block_group;
3166 if (!block_group) {
3167 spin_unlock(&cluster->lock);
3168 return;
3169 }
3170 } else if (cluster->block_group != block_group) {
3171 /* someone else has already freed it don't redo their work */
3172 spin_unlock(&cluster->lock);
3173 return;
3174 }
3175 btrfs_get_block_group(block_group);
3176 spin_unlock(&cluster->lock);
3177
3178 ctl = block_group->free_space_ctl;
3179
3180 /* now return any extents the cluster had on it */
3181 spin_lock(&ctl->tree_lock);
3182 __btrfs_return_cluster_to_free_space(block_group, cluster);
3183 spin_unlock(&ctl->tree_lock);
3184
3185 btrfs_discard_queue_work(&block_group->fs_info->discard_ctl, block_group);
3186
3187 /* finally drop our ref */
3188 btrfs_put_block_group(block_group);
3189 }
3190
3191 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group *block_group,
3192 struct btrfs_free_cluster *cluster,
3193 struct btrfs_free_space *entry,
3194 u64 bytes, u64 min_start,
3195 u64 *max_extent_size)
3196 {
3197 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3198 int err;
3199 u64 search_start = cluster->window_start;
3200 u64 search_bytes = bytes;
3201 u64 ret = 0;
3202
3203 search_start = min_start;
3204 search_bytes = bytes;
3205
3206 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
3207 if (err) {
3208 *max_extent_size = max(get_max_extent_size(entry),
3209 *max_extent_size);
3210 return 0;
3211 }
3212
3213 ret = search_start;
3214 bitmap_clear_bits(ctl, entry, ret, bytes, false);
3215
3216 return ret;
3217 }
3218
3219 /*
3220 * given a cluster, try to allocate 'bytes' from it, returns 0
3221 * if it couldn't find anything suitably large, or a logical disk offset
3222 * if things worked out
3223 */
3224 u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
3225 struct btrfs_free_cluster *cluster, u64 bytes,
3226 u64 min_start, u64 *max_extent_size)
3227 {
3228 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3229 struct btrfs_discard_ctl *discard_ctl =
3230 &block_group->fs_info->discard_ctl;
3231 struct btrfs_free_space *entry = NULL;
3232 struct rb_node *node;
3233 u64 ret = 0;
3234
3235 ASSERT(!btrfs_is_zoned(block_group->fs_info));
3236
3237 spin_lock(&cluster->lock);
3238 if (bytes > cluster->max_size)
3239 goto out;
3240
3241 if (cluster->block_group != block_group)
3242 goto out;
3243
3244 node = rb_first(&cluster->root);
3245 if (!node)
3246 goto out;
3247
3248 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3249 while (1) {
3250 if (entry->bytes < bytes)
3251 *max_extent_size = max(get_max_extent_size(entry),
3252 *max_extent_size);
3253
3254 if (entry->bytes < bytes ||
3255 (!entry->bitmap && entry->offset < min_start)) {
3256 node = rb_next(&entry->offset_index);
3257 if (!node)
3258 break;
3259 entry = rb_entry(node, struct btrfs_free_space,
3260 offset_index);
3261 continue;
3262 }
3263
3264 if (entry->bitmap) {
3265 ret = btrfs_alloc_from_bitmap(block_group,
3266 cluster, entry, bytes,
3267 cluster->window_start,
3268 max_extent_size);
3269 if (ret == 0) {
3270 node = rb_next(&entry->offset_index);
3271 if (!node)
3272 break;
3273 entry = rb_entry(node, struct btrfs_free_space,
3274 offset_index);
3275 continue;
3276 }
3277 cluster->window_start += bytes;
3278 } else {
3279 ret = entry->offset;
3280
3281 entry->offset += bytes;
3282 entry->bytes -= bytes;
3283 }
3284
3285 break;
3286 }
3287 out:
3288 spin_unlock(&cluster->lock);
3289
3290 if (!ret)
3291 return 0;
3292
3293 spin_lock(&ctl->tree_lock);
3294
3295 if (!btrfs_free_space_trimmed(entry))
3296 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3297
3298 ctl->free_space -= bytes;
3299 if (!entry->bitmap && !btrfs_free_space_trimmed(entry))
3300 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
3301
3302 spin_lock(&cluster->lock);
3303 if (entry->bytes == 0) {
3304 rb_erase(&entry->offset_index, &cluster->root);
3305 ctl->free_extents--;
3306 if (entry->bitmap) {
3307 kmem_cache_free(btrfs_free_space_bitmap_cachep,
3308 entry->bitmap);
3309 ctl->total_bitmaps--;
3310 recalculate_thresholds(ctl);
3311 } else if (!btrfs_free_space_trimmed(entry)) {
3312 ctl->discardable_extents[BTRFS_STAT_CURR]--;
3313 }
3314 kmem_cache_free(btrfs_free_space_cachep, entry);
3315 }
3316
3317 spin_unlock(&cluster->lock);
3318 spin_unlock(&ctl->tree_lock);
3319
3320 return ret;
3321 }
3322
3323 static int btrfs_bitmap_cluster(struct btrfs_block_group *block_group,
3324 struct btrfs_free_space *entry,
3325 struct btrfs_free_cluster *cluster,
3326 u64 offset, u64 bytes,
3327 u64 cont1_bytes, u64 min_bytes)
3328 {
3329 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3330 unsigned long next_zero;
3331 unsigned long i;
3332 unsigned long want_bits;
3333 unsigned long min_bits;
3334 unsigned long found_bits;
3335 unsigned long max_bits = 0;
3336 unsigned long start = 0;
3337 unsigned long total_found = 0;
3338 int ret;
3339
3340 lockdep_assert_held(&ctl->tree_lock);
3341
3342 i = offset_to_bit(entry->offset, ctl->unit,
3343 max_t(u64, offset, entry->offset));
3344 want_bits = bytes_to_bits(bytes, ctl->unit);
3345 min_bits = bytes_to_bits(min_bytes, ctl->unit);
3346
3347 /*
3348 * Don't bother looking for a cluster in this bitmap if it's heavily
3349 * fragmented.
3350 */
3351 if (entry->max_extent_size &&
3352 entry->max_extent_size < cont1_bytes)
3353 return -ENOSPC;
3354 again:
3355 found_bits = 0;
3356 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
3357 next_zero = find_next_zero_bit(entry->bitmap,
3358 BITS_PER_BITMAP, i);
3359 if (next_zero - i >= min_bits) {
3360 found_bits = next_zero - i;
3361 if (found_bits > max_bits)
3362 max_bits = found_bits;
3363 break;
3364 }
3365 if (next_zero - i > max_bits)
3366 max_bits = next_zero - i;
3367 i = next_zero;
3368 }
3369
3370 if (!found_bits) {
3371 entry->max_extent_size = (u64)max_bits * ctl->unit;
3372 return -ENOSPC;
3373 }
3374
3375 if (!total_found) {
3376 start = i;
3377 cluster->max_size = 0;
3378 }
3379
3380 total_found += found_bits;
3381
3382 if (cluster->max_size < found_bits * ctl->unit)
3383 cluster->max_size = found_bits * ctl->unit;
3384
3385 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
3386 i = next_zero + 1;
3387 goto again;
3388 }
3389
3390 cluster->window_start = start * ctl->unit + entry->offset;
3391 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3392 rb_erase_cached(&entry->bytes_index, &ctl->free_space_bytes);
3393
3394 /*
3395 * We need to know if we're currently on the normal space index when we
3396 * manipulate the bitmap so that we know we need to remove and re-insert
3397 * it into the space_index tree. Clear the bytes_index node here so the
3398 * bitmap manipulation helpers know not to mess with the space_index
3399 * until this bitmap entry is added back into the normal cache.
3400 */
3401 RB_CLEAR_NODE(&entry->bytes_index);
3402
3403 ret = tree_insert_offset(ctl, cluster, entry);
3404 ASSERT(!ret); /* -EEXIST; Logic error */
3405
3406 trace_btrfs_setup_cluster(block_group, cluster,
3407 total_found * ctl->unit, 1);
3408 return 0;
3409 }
3410
3411 /*
3412 * This searches the block group for just extents to fill the cluster with.
3413 * Try to find a cluster with at least bytes total bytes, at least one
3414 * extent of cont1_bytes, and other clusters of at least min_bytes.
3415 */
3416 static noinline int
3417 setup_cluster_no_bitmap(struct btrfs_block_group *block_group,
3418 struct btrfs_free_cluster *cluster,
3419 struct list_head *bitmaps, u64 offset, u64 bytes,
3420 u64 cont1_bytes, u64 min_bytes)
3421 {
3422 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3423 struct btrfs_free_space *first = NULL;
3424 struct btrfs_free_space *entry = NULL;
3425 struct btrfs_free_space *last;
3426 struct rb_node *node;
3427 u64 window_free;
3428 u64 max_extent;
3429 u64 total_size = 0;
3430
3431 lockdep_assert_held(&ctl->tree_lock);
3432
3433 entry = tree_search_offset(ctl, offset, 0, 1);
3434 if (!entry)
3435 return -ENOSPC;
3436
3437 /*
3438 * We don't want bitmaps, so just move along until we find a normal
3439 * extent entry.
3440 */
3441 while (entry->bitmap || entry->bytes < min_bytes) {
3442 if (entry->bitmap && list_empty(&entry->list))
3443 list_add_tail(&entry->list, bitmaps);
3444 node = rb_next(&entry->offset_index);
3445 if (!node)
3446 return -ENOSPC;
3447 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3448 }
3449
3450 window_free = entry->bytes;
3451 max_extent = entry->bytes;
3452 first = entry;
3453 last = entry;
3454
3455 for (node = rb_next(&entry->offset_index); node;
3456 node = rb_next(&entry->offset_index)) {
3457 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3458
3459 if (entry->bitmap) {
3460 if (list_empty(&entry->list))
3461 list_add_tail(&entry->list, bitmaps);
3462 continue;
3463 }
3464
3465 if (entry->bytes < min_bytes)
3466 continue;
3467
3468 last = entry;
3469 window_free += entry->bytes;
3470 if (entry->bytes > max_extent)
3471 max_extent = entry->bytes;
3472 }
3473
3474 if (window_free < bytes || max_extent < cont1_bytes)
3475 return -ENOSPC;
3476
3477 cluster->window_start = first->offset;
3478
3479 node = &first->offset_index;
3480
3481 /*
3482 * now we've found our entries, pull them out of the free space
3483 * cache and put them into the cluster rbtree
3484 */
3485 do {
3486 int ret;
3487
3488 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3489 node = rb_next(&entry->offset_index);
3490 if (entry->bitmap || entry->bytes < min_bytes)
3491 continue;
3492
3493 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3494 rb_erase_cached(&entry->bytes_index, &ctl->free_space_bytes);
3495 ret = tree_insert_offset(ctl, cluster, entry);
3496 total_size += entry->bytes;
3497 ASSERT(!ret); /* -EEXIST; Logic error */
3498 } while (node && entry != last);
3499
3500 cluster->max_size = max_extent;
3501 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
3502 return 0;
3503 }
3504
3505 /*
3506 * This specifically looks for bitmaps that may work in the cluster, we assume
3507 * that we have already failed to find extents that will work.
3508 */
3509 static noinline int
3510 setup_cluster_bitmap(struct btrfs_block_group *block_group,
3511 struct btrfs_free_cluster *cluster,
3512 struct list_head *bitmaps, u64 offset, u64 bytes,
3513 u64 cont1_bytes, u64 min_bytes)
3514 {
3515 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3516 struct btrfs_free_space *entry = NULL;
3517 int ret = -ENOSPC;
3518 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
3519
3520 if (ctl->total_bitmaps == 0)
3521 return -ENOSPC;
3522
3523 /*
3524 * The bitmap that covers offset won't be in the list unless offset
3525 * is just its start offset.
3526 */
3527 if (!list_empty(bitmaps))
3528 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
3529
3530 if (!entry || entry->offset != bitmap_offset) {
3531 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
3532 if (entry && list_empty(&entry->list))
3533 list_add(&entry->list, bitmaps);
3534 }
3535
3536 list_for_each_entry(entry, bitmaps, list) {
3537 if (entry->bytes < bytes)
3538 continue;
3539 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3540 bytes, cont1_bytes, min_bytes);
3541 if (!ret)
3542 return 0;
3543 }
3544
3545 /*
3546 * The bitmaps list has all the bitmaps that record free space
3547 * starting after offset, so no more search is required.
3548 */
3549 return -ENOSPC;
3550 }
3551
3552 /*
3553 * here we try to find a cluster of blocks in a block group. The goal
3554 * is to find at least bytes+empty_size.
3555 * We might not find them all in one contiguous area.
3556 *
3557 * returns zero and sets up cluster if things worked out, otherwise
3558 * it returns -enospc
3559 */
3560 int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
3561 struct btrfs_free_cluster *cluster,
3562 u64 offset, u64 bytes, u64 empty_size)
3563 {
3564 struct btrfs_fs_info *fs_info = block_group->fs_info;
3565 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3566 struct btrfs_free_space *entry, *tmp;
3567 LIST_HEAD(bitmaps);
3568 u64 min_bytes;
3569 u64 cont1_bytes;
3570 int ret;
3571
3572 /*
3573 * Choose the minimum extent size we'll require for this
3574 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3575 * For metadata, allow allocates with smaller extents. For
3576 * data, keep it dense.
3577 */
3578 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3579 cont1_bytes = bytes + empty_size;
3580 min_bytes = cont1_bytes;
3581 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3582 cont1_bytes = bytes;
3583 min_bytes = fs_info->sectorsize;
3584 } else {
3585 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3586 min_bytes = fs_info->sectorsize;
3587 }
3588
3589 spin_lock(&ctl->tree_lock);
3590
3591 /*
3592 * If we know we don't have enough space to make a cluster don't even
3593 * bother doing all the work to try and find one.
3594 */
3595 if (ctl->free_space < bytes) {
3596 spin_unlock(&ctl->tree_lock);
3597 return -ENOSPC;
3598 }
3599
3600 spin_lock(&cluster->lock);
3601
3602 /* someone already found a cluster, hooray */
3603 if (cluster->block_group) {
3604 ret = 0;
3605 goto out;
3606 }
3607
3608 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3609 min_bytes);
3610
3611 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3612 bytes + empty_size,
3613 cont1_bytes, min_bytes);
3614 if (ret)
3615 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3616 offset, bytes + empty_size,
3617 cont1_bytes, min_bytes);
3618
3619 /* Clear our temporary list */
3620 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3621 list_del_init(&entry->list);
3622
3623 if (!ret) {
3624 btrfs_get_block_group(block_group);
3625 list_add_tail(&cluster->block_group_list,
3626 &block_group->cluster_list);
3627 cluster->block_group = block_group;
3628 } else {
3629 trace_btrfs_failed_cluster_setup(block_group);
3630 }
3631 out:
3632 spin_unlock(&cluster->lock);
3633 spin_unlock(&ctl->tree_lock);
3634
3635 return ret;
3636 }
3637
3638 /*
3639 * simple code to zero out a cluster
3640 */
3641 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3642 {
3643 spin_lock_init(&cluster->lock);
3644 spin_lock_init(&cluster->refill_lock);
3645 cluster->root = RB_ROOT;
3646 cluster->max_size = 0;
3647 cluster->fragmented = false;
3648 INIT_LIST_HEAD(&cluster->block_group_list);
3649 cluster->block_group = NULL;
3650 }
3651
3652 static int do_trimming(struct btrfs_block_group *block_group,
3653 u64 *total_trimmed, u64 start, u64 bytes,
3654 u64 reserved_start, u64 reserved_bytes,
3655 enum btrfs_trim_state reserved_trim_state,
3656 struct btrfs_trim_range *trim_entry)
3657 {
3658 struct btrfs_space_info *space_info = block_group->space_info;
3659 struct btrfs_fs_info *fs_info = block_group->fs_info;
3660 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3661 int ret;
3662 int update = 0;
3663 const u64 end = start + bytes;
3664 const u64 reserved_end = reserved_start + reserved_bytes;
3665 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3666 u64 trimmed = 0;
3667
3668 spin_lock(&space_info->lock);
3669 spin_lock(&block_group->lock);
3670 if (!block_group->ro) {
3671 block_group->reserved += reserved_bytes;
3672 space_info->bytes_reserved += reserved_bytes;
3673 update = 1;
3674 }
3675 spin_unlock(&block_group->lock);
3676 spin_unlock(&space_info->lock);
3677
3678 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3679 if (!ret) {
3680 *total_trimmed += trimmed;
3681 trim_state = BTRFS_TRIM_STATE_TRIMMED;
3682 }
3683
3684 mutex_lock(&ctl->cache_writeout_mutex);
3685 if (reserved_start < start)
3686 __btrfs_add_free_space(block_group, reserved_start,
3687 start - reserved_start,
3688 reserved_trim_state);
3689 if (end < reserved_end)
3690 __btrfs_add_free_space(block_group, end, reserved_end - end,
3691 reserved_trim_state);
3692 __btrfs_add_free_space(block_group, start, bytes, trim_state);
3693 list_del(&trim_entry->list);
3694 mutex_unlock(&ctl->cache_writeout_mutex);
3695
3696 if (update) {
3697 spin_lock(&space_info->lock);
3698 spin_lock(&block_group->lock);
3699 if (block_group->ro)
3700 space_info->bytes_readonly += reserved_bytes;
3701 block_group->reserved -= reserved_bytes;
3702 space_info->bytes_reserved -= reserved_bytes;
3703 spin_unlock(&block_group->lock);
3704 spin_unlock(&space_info->lock);
3705 }
3706
3707 return ret;
3708 }
3709
3710 /*
3711 * If @async is set, then we will trim 1 region and return.
3712 */
3713 static int trim_no_bitmap(struct btrfs_block_group *block_group,
3714 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3715 bool async)
3716 {
3717 struct btrfs_discard_ctl *discard_ctl =
3718 &block_group->fs_info->discard_ctl;
3719 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3720 struct btrfs_free_space *entry;
3721 struct rb_node *node;
3722 int ret = 0;
3723 u64 extent_start;
3724 u64 extent_bytes;
3725 enum btrfs_trim_state extent_trim_state;
3726 u64 bytes;
3727 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3728
3729 while (start < end) {
3730 struct btrfs_trim_range trim_entry;
3731
3732 mutex_lock(&ctl->cache_writeout_mutex);
3733 spin_lock(&ctl->tree_lock);
3734
3735 if (ctl->free_space < minlen)
3736 goto out_unlock;
3737
3738 entry = tree_search_offset(ctl, start, 0, 1);
3739 if (!entry)
3740 goto out_unlock;
3741
3742 /* Skip bitmaps and if async, already trimmed entries */
3743 while (entry->bitmap ||
3744 (async && btrfs_free_space_trimmed(entry))) {
3745 node = rb_next(&entry->offset_index);
3746 if (!node)
3747 goto out_unlock;
3748 entry = rb_entry(node, struct btrfs_free_space,
3749 offset_index);
3750 }
3751
3752 if (entry->offset >= end)
3753 goto out_unlock;
3754
3755 extent_start = entry->offset;
3756 extent_bytes = entry->bytes;
3757 extent_trim_state = entry->trim_state;
3758 if (async) {
3759 start = entry->offset;
3760 bytes = entry->bytes;
3761 if (bytes < minlen) {
3762 spin_unlock(&ctl->tree_lock);
3763 mutex_unlock(&ctl->cache_writeout_mutex);
3764 goto next;
3765 }
3766 unlink_free_space(ctl, entry, true);
3767 /*
3768 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3769 * If X < BTRFS_ASYNC_DISCARD_MIN_FILTER, we won't trim
3770 * X when we come back around. So trim it now.
3771 */
3772 if (max_discard_size &&
3773 bytes >= (max_discard_size +
3774 BTRFS_ASYNC_DISCARD_MIN_FILTER)) {
3775 bytes = max_discard_size;
3776 extent_bytes = max_discard_size;
3777 entry->offset += max_discard_size;
3778 entry->bytes -= max_discard_size;
3779 link_free_space(ctl, entry);
3780 } else {
3781 kmem_cache_free(btrfs_free_space_cachep, entry);
3782 }
3783 } else {
3784 start = max(start, extent_start);
3785 bytes = min(extent_start + extent_bytes, end) - start;
3786 if (bytes < minlen) {
3787 spin_unlock(&ctl->tree_lock);
3788 mutex_unlock(&ctl->cache_writeout_mutex);
3789 goto next;
3790 }
3791
3792 unlink_free_space(ctl, entry, true);
3793 kmem_cache_free(btrfs_free_space_cachep, entry);
3794 }
3795
3796 spin_unlock(&ctl->tree_lock);
3797 trim_entry.start = extent_start;
3798 trim_entry.bytes = extent_bytes;
3799 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3800 mutex_unlock(&ctl->cache_writeout_mutex);
3801
3802 ret = do_trimming(block_group, total_trimmed, start, bytes,
3803 extent_start, extent_bytes, extent_trim_state,
3804 &trim_entry);
3805 if (ret) {
3806 block_group->discard_cursor = start + bytes;
3807 break;
3808 }
3809 next:
3810 start += bytes;
3811 block_group->discard_cursor = start;
3812 if (async && *total_trimmed)
3813 break;
3814
3815 if (btrfs_trim_interrupted()) {
3816 ret = -ERESTARTSYS;
3817 break;
3818 }
3819
3820 cond_resched();
3821 }
3822
3823 return ret;
3824
3825 out_unlock:
3826 block_group->discard_cursor = btrfs_block_group_end(block_group);
3827 spin_unlock(&ctl->tree_lock);
3828 mutex_unlock(&ctl->cache_writeout_mutex);
3829
3830 return ret;
3831 }
3832
3833 /*
3834 * If we break out of trimming a bitmap prematurely, we should reset the
3835 * trimming bit. In a rather contrieved case, it's possible to race here so
3836 * reset the state to BTRFS_TRIM_STATE_UNTRIMMED.
3837 *
3838 * start = start of bitmap
3839 * end = near end of bitmap
3840 *
3841 * Thread 1: Thread 2:
3842 * trim_bitmaps(start)
3843 * trim_bitmaps(end)
3844 * end_trimming_bitmap()
3845 * reset_trimming_bitmap()
3846 */
3847 static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset)
3848 {
3849 struct btrfs_free_space *entry;
3850
3851 spin_lock(&ctl->tree_lock);
3852 entry = tree_search_offset(ctl, offset, 1, 0);
3853 if (entry) {
3854 if (btrfs_free_space_trimmed(entry)) {
3855 ctl->discardable_extents[BTRFS_STAT_CURR] +=
3856 entry->bitmap_extents;
3857 ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes;
3858 }
3859 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3860 }
3861
3862 spin_unlock(&ctl->tree_lock);
3863 }
3864
3865 static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl,
3866 struct btrfs_free_space *entry)
3867 {
3868 if (btrfs_free_space_trimming_bitmap(entry)) {
3869 entry->trim_state = BTRFS_TRIM_STATE_TRIMMED;
3870 ctl->discardable_extents[BTRFS_STAT_CURR] -=
3871 entry->bitmap_extents;
3872 ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes;
3873 }
3874 }
3875
3876 /*
3877 * If @async is set, then we will trim 1 region and return.
3878 */
3879 static int trim_bitmaps(struct btrfs_block_group *block_group,
3880 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3881 u64 maxlen, bool async)
3882 {
3883 struct btrfs_discard_ctl *discard_ctl =
3884 &block_group->fs_info->discard_ctl;
3885 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3886 struct btrfs_free_space *entry;
3887 int ret = 0;
3888 int ret2;
3889 u64 bytes;
3890 u64 offset = offset_to_bitmap(ctl, start);
3891 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3892
3893 while (offset < end) {
3894 bool next_bitmap = false;
3895 struct btrfs_trim_range trim_entry;
3896
3897 mutex_lock(&ctl->cache_writeout_mutex);
3898 spin_lock(&ctl->tree_lock);
3899
3900 if (ctl->free_space < minlen) {
3901 block_group->discard_cursor =
3902 btrfs_block_group_end(block_group);
3903 spin_unlock(&ctl->tree_lock);
3904 mutex_unlock(&ctl->cache_writeout_mutex);
3905 break;
3906 }
3907
3908 entry = tree_search_offset(ctl, offset, 1, 0);
3909 /*
3910 * Bitmaps are marked trimmed lossily now to prevent constant
3911 * discarding of the same bitmap (the reason why we are bound
3912 * by the filters). So, retrim the block group bitmaps when we
3913 * are preparing to punt to the unused_bgs list. This uses
3914 * @minlen to determine if we are in BTRFS_DISCARD_INDEX_UNUSED
3915 * which is the only discard index which sets minlen to 0.
3916 */
3917 if (!entry || (async && minlen && start == offset &&
3918 btrfs_free_space_trimmed(entry))) {
3919 spin_unlock(&ctl->tree_lock);
3920 mutex_unlock(&ctl->cache_writeout_mutex);
3921 next_bitmap = true;
3922 goto next;
3923 }
3924
3925 /*
3926 * Async discard bitmap trimming begins at by setting the start
3927 * to be key.objectid and the offset_to_bitmap() aligns to the
3928 * start of the bitmap. This lets us know we are fully
3929 * scanning the bitmap rather than only some portion of it.
3930 */
3931 if (start == offset)
3932 entry->trim_state = BTRFS_TRIM_STATE_TRIMMING;
3933
3934 bytes = minlen;
3935 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3936 if (ret2 || start >= end) {
3937 /*
3938 * We lossily consider a bitmap trimmed if we only skip
3939 * over regions <= BTRFS_ASYNC_DISCARD_MIN_FILTER.
3940 */
3941 if (ret2 && minlen <= BTRFS_ASYNC_DISCARD_MIN_FILTER)
3942 end_trimming_bitmap(ctl, entry);
3943 else
3944 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3945 spin_unlock(&ctl->tree_lock);
3946 mutex_unlock(&ctl->cache_writeout_mutex);
3947 next_bitmap = true;
3948 goto next;
3949 }
3950
3951 /*
3952 * We already trimmed a region, but are using the locking above
3953 * to reset the trim_state.
3954 */
3955 if (async && *total_trimmed) {
3956 spin_unlock(&ctl->tree_lock);
3957 mutex_unlock(&ctl->cache_writeout_mutex);
3958 goto out;
3959 }
3960
3961 bytes = min(bytes, end - start);
3962 if (bytes < minlen || (async && maxlen && bytes > maxlen)) {
3963 spin_unlock(&ctl->tree_lock);
3964 mutex_unlock(&ctl->cache_writeout_mutex);
3965 goto next;
3966 }
3967
3968 /*
3969 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3970 * If X < @minlen, we won't trim X when we come back around.
3971 * So trim it now. We differ here from trimming extents as we
3972 * don't keep individual state per bit.
3973 */
3974 if (async &&
3975 max_discard_size &&
3976 bytes > (max_discard_size + minlen))
3977 bytes = max_discard_size;
3978
3979 bitmap_clear_bits(ctl, entry, start, bytes, true);
3980 if (entry->bytes == 0)
3981 free_bitmap(ctl, entry);
3982
3983 spin_unlock(&ctl->tree_lock);
3984 trim_entry.start = start;
3985 trim_entry.bytes = bytes;
3986 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3987 mutex_unlock(&ctl->cache_writeout_mutex);
3988
3989 ret = do_trimming(block_group, total_trimmed, start, bytes,
3990 start, bytes, 0, &trim_entry);
3991 if (ret) {
3992 reset_trimming_bitmap(ctl, offset);
3993 block_group->discard_cursor =
3994 btrfs_block_group_end(block_group);
3995 break;
3996 }
3997 next:
3998 if (next_bitmap) {
3999 offset += BITS_PER_BITMAP * ctl->unit;
4000 start = offset;
4001 } else {
4002 start += bytes;
4003 }
4004 block_group->discard_cursor = start;
4005
4006 if (btrfs_trim_interrupted()) {
4007 if (start != offset)
4008 reset_trimming_bitmap(ctl, offset);
4009 ret = -ERESTARTSYS;
4010 break;
4011 }
4012
4013 cond_resched();
4014 }
4015
4016 if (offset >= end)
4017 block_group->discard_cursor = end;
4018
4019 out:
4020 return ret;
4021 }
4022
4023 int btrfs_trim_block_group(struct btrfs_block_group *block_group,
4024 u64 *trimmed, u64 start, u64 end, u64 minlen)
4025 {
4026 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
4027 int ret;
4028 u64 rem = 0;
4029
4030 ASSERT(!btrfs_is_zoned(block_group->fs_info));
4031
4032 *trimmed = 0;
4033
4034 spin_lock(&block_group->lock);
4035 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags)) {
4036 spin_unlock(&block_group->lock);
4037 return 0;
4038 }
4039 btrfs_freeze_block_group(block_group);
4040 spin_unlock(&block_group->lock);
4041
4042 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, false);
4043 if (ret)
4044 goto out;
4045
4046 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, 0, false);
4047 div64_u64_rem(end, BITS_PER_BITMAP * ctl->unit, &rem);
4048 /* If we ended in the middle of a bitmap, reset the trimming flag */
4049 if (rem)
4050 reset_trimming_bitmap(ctl, offset_to_bitmap(ctl, end));
4051 out:
4052 btrfs_unfreeze_block_group(block_group);
4053 return ret;
4054 }
4055
4056 int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
4057 u64 *trimmed, u64 start, u64 end, u64 minlen,
4058 bool async)
4059 {
4060 int ret;
4061
4062 *trimmed = 0;
4063
4064 spin_lock(&block_group->lock);
4065 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags)) {
4066 spin_unlock(&block_group->lock);
4067 return 0;
4068 }
4069 btrfs_freeze_block_group(block_group);
4070 spin_unlock(&block_group->lock);
4071
4072 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, async);
4073 btrfs_unfreeze_block_group(block_group);
4074
4075 return ret;
4076 }
4077
4078 int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
4079 u64 *trimmed, u64 start, u64 end, u64 minlen,
4080 u64 maxlen, bool async)
4081 {
4082 int ret;
4083
4084 *trimmed = 0;
4085
4086 spin_lock(&block_group->lock);
4087 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags)) {
4088 spin_unlock(&block_group->lock);
4089 return 0;
4090 }
4091 btrfs_freeze_block_group(block_group);
4092 spin_unlock(&block_group->lock);
4093
4094 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, maxlen,
4095 async);
4096
4097 btrfs_unfreeze_block_group(block_group);
4098
4099 return ret;
4100 }
4101
4102 bool btrfs_free_space_cache_v1_active(struct btrfs_fs_info *fs_info)
4103 {
4104 return btrfs_super_cache_generation(fs_info->super_copy);
4105 }
4106
4107 static int cleanup_free_space_cache_v1(struct btrfs_fs_info *fs_info,
4108 struct btrfs_trans_handle *trans)
4109 {
4110 struct btrfs_block_group *block_group;
4111 struct rb_node *node;
4112 int ret = 0;
4113
4114 btrfs_info(fs_info, "cleaning free space cache v1");
4115
4116 node = rb_first_cached(&fs_info->block_group_cache_tree);
4117 while (node) {
4118 block_group = rb_entry(node, struct btrfs_block_group, cache_node);
4119 ret = btrfs_remove_free_space_inode(trans, NULL, block_group);
4120 if (ret)
4121 goto out;
4122 node = rb_next(node);
4123 }
4124 out:
4125 return ret;
4126 }
4127
4128 int btrfs_set_free_space_cache_v1_active(struct btrfs_fs_info *fs_info, bool active)
4129 {
4130 struct btrfs_trans_handle *trans;
4131 int ret;
4132
4133 /*
4134 * update_super_roots will appropriately set or unset
4135 * super_copy->cache_generation based on SPACE_CACHE and
4136 * BTRFS_FS_CLEANUP_SPACE_CACHE_V1. For this reason, we need a
4137 * transaction commit whether we are enabling space cache v1 and don't
4138 * have any other work to do, or are disabling it and removing free
4139 * space inodes.
4140 */
4141 trans = btrfs_start_transaction(fs_info->tree_root, 0);
4142 if (IS_ERR(trans))
4143 return PTR_ERR(trans);
4144
4145 if (!active) {
4146 set_bit(BTRFS_FS_CLEANUP_SPACE_CACHE_V1, &fs_info->flags);
4147 ret = cleanup_free_space_cache_v1(fs_info, trans);
4148 if (ret) {
4149 btrfs_abort_transaction(trans, ret);
4150 btrfs_end_transaction(trans);
4151 goto out;
4152 }
4153 }
4154
4155 ret = btrfs_commit_transaction(trans);
4156 out:
4157 clear_bit(BTRFS_FS_CLEANUP_SPACE_CACHE_V1, &fs_info->flags);
4158
4159 return ret;
4160 }
4161
4162 int __init btrfs_free_space_init(void)
4163 {
4164 btrfs_free_space_cachep = KMEM_CACHE(btrfs_free_space, 0);
4165 if (!btrfs_free_space_cachep)
4166 return -ENOMEM;
4167
4168 btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap",
4169 PAGE_SIZE, PAGE_SIZE,
4170 0, NULL);
4171 if (!btrfs_free_space_bitmap_cachep) {
4172 kmem_cache_destroy(btrfs_free_space_cachep);
4173 return -ENOMEM;
4174 }
4175
4176 return 0;
4177 }
4178
4179 void __cold btrfs_free_space_exit(void)
4180 {
4181 kmem_cache_destroy(btrfs_free_space_cachep);
4182 kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
4183 }
4184
4185 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4186 /*
4187 * Use this if you need to make a bitmap or extent entry specifically, it
4188 * doesn't do any of the merging that add_free_space does, this acts a lot like
4189 * how the free space cache loading stuff works, so you can get really weird
4190 * configurations.
4191 */
4192 int test_add_free_space_entry(struct btrfs_block_group *cache,
4193 u64 offset, u64 bytes, bool bitmap)
4194 {
4195 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4196 struct btrfs_free_space *info = NULL, *bitmap_info;
4197 void *map = NULL;
4198 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_TRIMMED;
4199 u64 bytes_added;
4200 int ret;
4201
4202 again:
4203 if (!info) {
4204 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
4205 if (!info)
4206 return -ENOMEM;
4207 }
4208
4209 if (!bitmap) {
4210 spin_lock(&ctl->tree_lock);
4211 info->offset = offset;
4212 info->bytes = bytes;
4213 info->max_extent_size = 0;
4214 ret = link_free_space(ctl, info);
4215 spin_unlock(&ctl->tree_lock);
4216 if (ret)
4217 kmem_cache_free(btrfs_free_space_cachep, info);
4218 return ret;
4219 }
4220
4221 if (!map) {
4222 map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
4223 if (!map) {
4224 kmem_cache_free(btrfs_free_space_cachep, info);
4225 return -ENOMEM;
4226 }
4227 }
4228
4229 spin_lock(&ctl->tree_lock);
4230 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4231 1, 0);
4232 if (!bitmap_info) {
4233 info->bitmap = map;
4234 map = NULL;
4235 add_new_bitmap(ctl, info, offset);
4236 bitmap_info = info;
4237 info = NULL;
4238 }
4239
4240 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
4241 trim_state);
4242
4243 bytes -= bytes_added;
4244 offset += bytes_added;
4245 spin_unlock(&ctl->tree_lock);
4246
4247 if (bytes)
4248 goto again;
4249
4250 if (info)
4251 kmem_cache_free(btrfs_free_space_cachep, info);
4252 if (map)
4253 kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
4254 return 0;
4255 }
4256
4257 /*
4258 * Checks to see if the given range is in the free space cache. This is really
4259 * just used to check the absence of space, so if there is free space in the
4260 * range at all we will return 1.
4261 */
4262 int test_check_exists(struct btrfs_block_group *cache,
4263 u64 offset, u64 bytes)
4264 {
4265 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4266 struct btrfs_free_space *info;
4267 int ret = 0;
4268
4269 spin_lock(&ctl->tree_lock);
4270 info = tree_search_offset(ctl, offset, 0, 0);
4271 if (!info) {
4272 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4273 1, 0);
4274 if (!info)
4275 goto out;
4276 }
4277
4278 have_info:
4279 if (info->bitmap) {
4280 u64 bit_off, bit_bytes;
4281 struct rb_node *n;
4282 struct btrfs_free_space *tmp;
4283
4284 bit_off = offset;
4285 bit_bytes = ctl->unit;
4286 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
4287 if (!ret) {
4288 if (bit_off == offset) {
4289 ret = 1;
4290 goto out;
4291 } else if (bit_off > offset &&
4292 offset + bytes > bit_off) {
4293 ret = 1;
4294 goto out;
4295 }
4296 }
4297
4298 n = rb_prev(&info->offset_index);
4299 while (n) {
4300 tmp = rb_entry(n, struct btrfs_free_space,
4301 offset_index);
4302 if (tmp->offset + tmp->bytes < offset)
4303 break;
4304 if (offset + bytes < tmp->offset) {
4305 n = rb_prev(&tmp->offset_index);
4306 continue;
4307 }
4308 info = tmp;
4309 goto have_info;
4310 }
4311
4312 n = rb_next(&info->offset_index);
4313 while (n) {
4314 tmp = rb_entry(n, struct btrfs_free_space,
4315 offset_index);
4316 if (offset + bytes < tmp->offset)
4317 break;
4318 if (tmp->offset + tmp->bytes < offset) {
4319 n = rb_next(&tmp->offset_index);
4320 continue;
4321 }
4322 info = tmp;
4323 goto have_info;
4324 }
4325
4326 ret = 0;
4327 goto out;
4328 }
4329
4330 if (info->offset == offset) {
4331 ret = 1;
4332 goto out;
4333 }
4334
4335 if (offset > info->offset && offset < info->offset + info->bytes)
4336 ret = 1;
4337 out:
4338 spin_unlock(&ctl->tree_lock);
4339 return ret;
4340 }
4341 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Kernel DRM miscellaneous fixes and cross-tree changes