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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 "ctree.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
37static struct kmem_cache *btrfs_free_space_cachep;
38static struct kmem_cache *btrfs_free_space_bitmap_cachep;
39
40struct btrfs_trim_range {
41 u64 start;
42 u64 bytes;
43 struct list_head list;
44};
45
46static int link_free_space(struct btrfs_free_space_ctl *ctl,
47 struct btrfs_free_space *info);
48static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
49 struct btrfs_free_space *info, bool update_stat);
50static int search_bitmap(struct btrfs_free_space_ctl *ctl,
51 struct btrfs_free_space *bitmap_info, u64 *offset,
52 u64 *bytes, bool for_alloc);
53static void free_bitmap(struct btrfs_free_space_ctl *ctl,
54 struct btrfs_free_space *bitmap_info);
55static 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
59static void btrfs_crc32c_final(u32 crc, u8 *result)
60{
61 put_unaligned_le32(~crc, result);
62}
63
64static 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
82static 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
132struct 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
166static 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_mark_buffer_dirty(trans, leaf);
202 btrfs_release_path(path);
203
204 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
205 key.offset = offset;
206 key.type = 0;
207 ret = btrfs_insert_empty_item(trans, root, path, &key,
208 sizeof(struct btrfs_free_space_header));
209 if (ret < 0) {
210 btrfs_release_path(path);
211 return ret;
212 }
213
214 leaf = path->nodes[0];
215 header = btrfs_item_ptr(leaf, path->slots[0],
216 struct btrfs_free_space_header);
217 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
218 btrfs_set_free_space_key(leaf, header, &disk_key);
219 btrfs_mark_buffer_dirty(trans, leaf);
220 btrfs_release_path(path);
221
222 return 0;
223}
224
225int create_free_space_inode(struct btrfs_trans_handle *trans,
226 struct btrfs_block_group *block_group,
227 struct btrfs_path *path)
228{
229 int ret;
230 u64 ino;
231
232 ret = btrfs_get_free_objectid(trans->fs_info->tree_root, &ino);
233 if (ret < 0)
234 return ret;
235
236 return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
237 ino, block_group->start);
238}
239
240/*
241 * inode is an optional sink: if it is NULL, btrfs_remove_free_space_inode
242 * handles lookup, otherwise it takes ownership and iputs the inode.
243 * Don't reuse an inode pointer after passing it into this function.
244 */
245int btrfs_remove_free_space_inode(struct btrfs_trans_handle *trans,
246 struct inode *inode,
247 struct btrfs_block_group *block_group)
248{
249 struct btrfs_path *path;
250 struct btrfs_key key;
251 int ret = 0;
252
253 path = btrfs_alloc_path();
254 if (!path)
255 return -ENOMEM;
256
257 if (!inode)
258 inode = lookup_free_space_inode(block_group, path);
259 if (IS_ERR(inode)) {
260 if (PTR_ERR(inode) != -ENOENT)
261 ret = PTR_ERR(inode);
262 goto out;
263 }
264 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
265 if (ret) {
266 btrfs_add_delayed_iput(BTRFS_I(inode));
267 goto out;
268 }
269 clear_nlink(inode);
270 /* One for the block groups ref */
271 spin_lock(&block_group->lock);
272 if (test_and_clear_bit(BLOCK_GROUP_FLAG_IREF, &block_group->runtime_flags)) {
273 block_group->inode = NULL;
274 spin_unlock(&block_group->lock);
275 iput(inode);
276 } else {
277 spin_unlock(&block_group->lock);
278 }
279 /* One for the lookup ref */
280 btrfs_add_delayed_iput(BTRFS_I(inode));
281
282 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
283 key.type = 0;
284 key.offset = block_group->start;
285 ret = btrfs_search_slot(trans, trans->fs_info->tree_root, &key, path,
286 -1, 1);
287 if (ret) {
288 if (ret > 0)
289 ret = 0;
290 goto out;
291 }
292 ret = btrfs_del_item(trans, trans->fs_info->tree_root, path);
293out:
294 btrfs_free_path(path);
295 return ret;
296}
297
298int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
299 struct btrfs_block_group *block_group,
300 struct inode *vfs_inode)
301{
302 struct btrfs_truncate_control control = {
303 .inode = BTRFS_I(vfs_inode),
304 .new_size = 0,
305 .ino = btrfs_ino(BTRFS_I(vfs_inode)),
306 .min_type = BTRFS_EXTENT_DATA_KEY,
307 .clear_extent_range = true,
308 };
309 struct btrfs_inode *inode = BTRFS_I(vfs_inode);
310 struct btrfs_root *root = inode->root;
311 struct extent_state *cached_state = NULL;
312 int ret = 0;
313 bool locked = false;
314
315 if (block_group) {
316 struct btrfs_path *path = btrfs_alloc_path();
317
318 if (!path) {
319 ret = -ENOMEM;
320 goto fail;
321 }
322 locked = true;
323 mutex_lock(&trans->transaction->cache_write_mutex);
324 if (!list_empty(&block_group->io_list)) {
325 list_del_init(&block_group->io_list);
326
327 btrfs_wait_cache_io(trans, block_group, path);
328 btrfs_put_block_group(block_group);
329 }
330
331 /*
332 * now that we've truncated the cache away, its no longer
333 * setup or written
334 */
335 spin_lock(&block_group->lock);
336 block_group->disk_cache_state = BTRFS_DC_CLEAR;
337 spin_unlock(&block_group->lock);
338 btrfs_free_path(path);
339 }
340
341 btrfs_i_size_write(inode, 0);
342 truncate_pagecache(vfs_inode, 0);
343
344 lock_extent(&inode->io_tree, 0, (u64)-1, &cached_state);
345 btrfs_drop_extent_map_range(inode, 0, (u64)-1, false);
346
347 /*
348 * We skip the throttling logic for free space cache inodes, so we don't
349 * need to check for -EAGAIN.
350 */
351 ret = btrfs_truncate_inode_items(trans, root, &control);
352
353 inode_sub_bytes(&inode->vfs_inode, control.sub_bytes);
354 btrfs_inode_safe_disk_i_size_write(inode, control.last_size);
355
356 unlock_extent(&inode->io_tree, 0, (u64)-1, &cached_state);
357 if (ret)
358 goto fail;
359
360 ret = btrfs_update_inode(trans, inode);
361
362fail:
363 if (locked)
364 mutex_unlock(&trans->transaction->cache_write_mutex);
365 if (ret)
366 btrfs_abort_transaction(trans, ret);
367
368 return ret;
369}
370
371static void readahead_cache(struct inode *inode)
372{
373 struct file_ra_state ra;
374 unsigned long last_index;
375
376 file_ra_state_init(&ra, inode->i_mapping);
377 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
378
379 page_cache_sync_readahead(inode->i_mapping, &ra, NULL, 0, last_index);
380}
381
382static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
383 int write)
384{
385 int num_pages;
386
387 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
388
389 /* Make sure we can fit our crcs and generation into the first page */
390 if (write && (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
391 return -ENOSPC;
392
393 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
394
395 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
396 if (!io_ctl->pages)
397 return -ENOMEM;
398
399 io_ctl->num_pages = num_pages;
400 io_ctl->fs_info = inode_to_fs_info(inode);
401 io_ctl->inode = inode;
402
403 return 0;
404}
405ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
406
407static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
408{
409 kfree(io_ctl->pages);
410 io_ctl->pages = NULL;
411}
412
413static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
414{
415 if (io_ctl->cur) {
416 io_ctl->cur = NULL;
417 io_ctl->orig = NULL;
418 }
419}
420
421static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
422{
423 ASSERT(io_ctl->index < io_ctl->num_pages);
424 io_ctl->page = io_ctl->pages[io_ctl->index++];
425 io_ctl->cur = page_address(io_ctl->page);
426 io_ctl->orig = io_ctl->cur;
427 io_ctl->size = PAGE_SIZE;
428 if (clear)
429 clear_page(io_ctl->cur);
430}
431
432static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
433{
434 int i;
435
436 io_ctl_unmap_page(io_ctl);
437
438 for (i = 0; i < io_ctl->num_pages; i++) {
439 if (io_ctl->pages[i]) {
440 btrfs_folio_clear_checked(io_ctl->fs_info,
441 page_folio(io_ctl->pages[i]),
442 page_offset(io_ctl->pages[i]),
443 PAGE_SIZE);
444 unlock_page(io_ctl->pages[i]);
445 put_page(io_ctl->pages[i]);
446 }
447 }
448}
449
450static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, bool uptodate)
451{
452 struct page *page;
453 struct inode *inode = io_ctl->inode;
454 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
455 int i;
456
457 for (i = 0; i < io_ctl->num_pages; i++) {
458 int ret;
459
460 page = find_or_create_page(inode->i_mapping, i, mask);
461 if (!page) {
462 io_ctl_drop_pages(io_ctl);
463 return -ENOMEM;
464 }
465
466 ret = set_page_extent_mapped(page);
467 if (ret < 0) {
468 unlock_page(page);
469 put_page(page);
470 io_ctl_drop_pages(io_ctl);
471 return ret;
472 }
473
474 io_ctl->pages[i] = page;
475 if (uptodate && !PageUptodate(page)) {
476 btrfs_read_folio(NULL, page_folio(page));
477 lock_page(page);
478 if (page->mapping != inode->i_mapping) {
479 btrfs_err(BTRFS_I(inode)->root->fs_info,
480 "free space cache page truncated");
481 io_ctl_drop_pages(io_ctl);
482 return -EIO;
483 }
484 if (!PageUptodate(page)) {
485 btrfs_err(BTRFS_I(inode)->root->fs_info,
486 "error reading free space cache");
487 io_ctl_drop_pages(io_ctl);
488 return -EIO;
489 }
490 }
491 }
492
493 for (i = 0; i < io_ctl->num_pages; i++)
494 clear_page_dirty_for_io(io_ctl->pages[i]);
495
496 return 0;
497}
498
499static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
500{
501 io_ctl_map_page(io_ctl, 1);
502
503 /*
504 * Skip the csum areas. If we don't check crcs then we just have a
505 * 64bit chunk at the front of the first page.
506 */
507 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
508 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
509
510 put_unaligned_le64(generation, io_ctl->cur);
511 io_ctl->cur += sizeof(u64);
512}
513
514static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
515{
516 u64 cache_gen;
517
518 /*
519 * Skip the crc area. If we don't check crcs then we just have a 64bit
520 * chunk at the front of the first page.
521 */
522 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
523 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
524
525 cache_gen = get_unaligned_le64(io_ctl->cur);
526 if (cache_gen != generation) {
527 btrfs_err_rl(io_ctl->fs_info,
528 "space cache generation (%llu) does not match inode (%llu)",
529 cache_gen, generation);
530 io_ctl_unmap_page(io_ctl);
531 return -EIO;
532 }
533 io_ctl->cur += sizeof(u64);
534 return 0;
535}
536
537static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
538{
539 u32 *tmp;
540 u32 crc = ~(u32)0;
541 unsigned offset = 0;
542
543 if (index == 0)
544 offset = sizeof(u32) * io_ctl->num_pages;
545
546 crc = crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
547 btrfs_crc32c_final(crc, (u8 *)&crc);
548 io_ctl_unmap_page(io_ctl);
549 tmp = page_address(io_ctl->pages[0]);
550 tmp += index;
551 *tmp = crc;
552}
553
554static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
555{
556 u32 *tmp, val;
557 u32 crc = ~(u32)0;
558 unsigned offset = 0;
559
560 if (index == 0)
561 offset = sizeof(u32) * io_ctl->num_pages;
562
563 tmp = page_address(io_ctl->pages[0]);
564 tmp += index;
565 val = *tmp;
566
567 io_ctl_map_page(io_ctl, 0);
568 crc = crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
569 btrfs_crc32c_final(crc, (u8 *)&crc);
570 if (val != crc) {
571 btrfs_err_rl(io_ctl->fs_info,
572 "csum mismatch on free space cache");
573 io_ctl_unmap_page(io_ctl);
574 return -EIO;
575 }
576
577 return 0;
578}
579
580static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
581 void *bitmap)
582{
583 struct btrfs_free_space_entry *entry;
584
585 if (!io_ctl->cur)
586 return -ENOSPC;
587
588 entry = io_ctl->cur;
589 put_unaligned_le64(offset, &entry->offset);
590 put_unaligned_le64(bytes, &entry->bytes);
591 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
592 BTRFS_FREE_SPACE_EXTENT;
593 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
594 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
595
596 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
597 return 0;
598
599 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
600
601 /* No more pages to map */
602 if (io_ctl->index >= io_ctl->num_pages)
603 return 0;
604
605 /* map the next page */
606 io_ctl_map_page(io_ctl, 1);
607 return 0;
608}
609
610static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
611{
612 if (!io_ctl->cur)
613 return -ENOSPC;
614
615 /*
616 * If we aren't at the start of the current page, unmap this one and
617 * map the next one if there is any left.
618 */
619 if (io_ctl->cur != io_ctl->orig) {
620 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
621 if (io_ctl->index >= io_ctl->num_pages)
622 return -ENOSPC;
623 io_ctl_map_page(io_ctl, 0);
624 }
625
626 copy_page(io_ctl->cur, bitmap);
627 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
628 if (io_ctl->index < io_ctl->num_pages)
629 io_ctl_map_page(io_ctl, 0);
630 return 0;
631}
632
633static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
634{
635 /*
636 * If we're not on the boundary we know we've modified the page and we
637 * need to crc the page.
638 */
639 if (io_ctl->cur != io_ctl->orig)
640 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
641 else
642 io_ctl_unmap_page(io_ctl);
643
644 while (io_ctl->index < io_ctl->num_pages) {
645 io_ctl_map_page(io_ctl, 1);
646 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
647 }
648}
649
650static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
651 struct btrfs_free_space *entry, u8 *type)
652{
653 struct btrfs_free_space_entry *e;
654 int ret;
655
656 if (!io_ctl->cur) {
657 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
658 if (ret)
659 return ret;
660 }
661
662 e = io_ctl->cur;
663 entry->offset = get_unaligned_le64(&e->offset);
664 entry->bytes = get_unaligned_le64(&e->bytes);
665 *type = e->type;
666 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
667 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
668
669 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
670 return 0;
671
672 io_ctl_unmap_page(io_ctl);
673
674 return 0;
675}
676
677static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
678 struct btrfs_free_space *entry)
679{
680 int ret;
681
682 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
683 if (ret)
684 return ret;
685
686 copy_page(entry->bitmap, io_ctl->cur);
687 io_ctl_unmap_page(io_ctl);
688
689 return 0;
690}
691
692static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
693{
694 struct btrfs_block_group *block_group = ctl->block_group;
695 u64 max_bytes;
696 u64 bitmap_bytes;
697 u64 extent_bytes;
698 u64 size = block_group->length;
699 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
700 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
701
702 max_bitmaps = max_t(u64, max_bitmaps, 1);
703
704 if (ctl->total_bitmaps > max_bitmaps)
705 btrfs_err(block_group->fs_info,
706"invalid free space control: bg start=%llu len=%llu total_bitmaps=%u unit=%u max_bitmaps=%llu bytes_per_bg=%llu",
707 block_group->start, block_group->length,
708 ctl->total_bitmaps, ctl->unit, max_bitmaps,
709 bytes_per_bg);
710 ASSERT(ctl->total_bitmaps <= max_bitmaps);
711
712 /*
713 * We are trying to keep the total amount of memory used per 1GiB of
714 * space to be MAX_CACHE_BYTES_PER_GIG. However, with a reclamation
715 * mechanism of pulling extents >= FORCE_EXTENT_THRESHOLD out of
716 * bitmaps, we may end up using more memory than this.
717 */
718 if (size < SZ_1G)
719 max_bytes = MAX_CACHE_BYTES_PER_GIG;
720 else
721 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
722
723 bitmap_bytes = ctl->total_bitmaps * ctl->unit;
724
725 /*
726 * we want the extent entry threshold to always be at most 1/2 the max
727 * bytes we can have, or whatever is less than that.
728 */
729 extent_bytes = max_bytes - bitmap_bytes;
730 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
731
732 ctl->extents_thresh =
733 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
734}
735
736static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
737 struct btrfs_free_space_ctl *ctl,
738 struct btrfs_path *path, u64 offset)
739{
740 struct btrfs_fs_info *fs_info = root->fs_info;
741 struct btrfs_free_space_header *header;
742 struct extent_buffer *leaf;
743 struct btrfs_io_ctl io_ctl;
744 struct btrfs_key key;
745 struct btrfs_free_space *e, *n;
746 LIST_HEAD(bitmaps);
747 u64 num_entries;
748 u64 num_bitmaps;
749 u64 generation;
750 u8 type;
751 int ret = 0;
752
753 /* Nothing in the space cache, goodbye */
754 if (!i_size_read(inode))
755 return 0;
756
757 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
758 key.offset = offset;
759 key.type = 0;
760
761 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
762 if (ret < 0)
763 return 0;
764 else if (ret > 0) {
765 btrfs_release_path(path);
766 return 0;
767 }
768
769 ret = -1;
770
771 leaf = path->nodes[0];
772 header = btrfs_item_ptr(leaf, path->slots[0],
773 struct btrfs_free_space_header);
774 num_entries = btrfs_free_space_entries(leaf, header);
775 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
776 generation = btrfs_free_space_generation(leaf, header);
777 btrfs_release_path(path);
778
779 if (!BTRFS_I(inode)->generation) {
780 btrfs_info(fs_info,
781 "the free space cache file (%llu) is invalid, skip it",
782 offset);
783 return 0;
784 }
785
786 if (BTRFS_I(inode)->generation != generation) {
787 btrfs_err(fs_info,
788 "free space inode generation (%llu) did not match free space cache generation (%llu)",
789 BTRFS_I(inode)->generation, generation);
790 return 0;
791 }
792
793 if (!num_entries)
794 return 0;
795
796 ret = io_ctl_init(&io_ctl, inode, 0);
797 if (ret)
798 return ret;
799
800 readahead_cache(inode);
801
802 ret = io_ctl_prepare_pages(&io_ctl, true);
803 if (ret)
804 goto out;
805
806 ret = io_ctl_check_crc(&io_ctl, 0);
807 if (ret)
808 goto free_cache;
809
810 ret = io_ctl_check_generation(&io_ctl, generation);
811 if (ret)
812 goto free_cache;
813
814 while (num_entries) {
815 e = kmem_cache_zalloc(btrfs_free_space_cachep,
816 GFP_NOFS);
817 if (!e) {
818 ret = -ENOMEM;
819 goto free_cache;
820 }
821
822 ret = io_ctl_read_entry(&io_ctl, e, &type);
823 if (ret) {
824 kmem_cache_free(btrfs_free_space_cachep, e);
825 goto free_cache;
826 }
827
828 if (!e->bytes) {
829 ret = -1;
830 kmem_cache_free(btrfs_free_space_cachep, e);
831 goto free_cache;
832 }
833
834 if (type == BTRFS_FREE_SPACE_EXTENT) {
835 spin_lock(&ctl->tree_lock);
836 ret = link_free_space(ctl, e);
837 spin_unlock(&ctl->tree_lock);
838 if (ret) {
839 btrfs_err(fs_info,
840 "Duplicate entries in free space cache, dumping");
841 kmem_cache_free(btrfs_free_space_cachep, e);
842 goto free_cache;
843 }
844 } else {
845 ASSERT(num_bitmaps);
846 num_bitmaps--;
847 e->bitmap = kmem_cache_zalloc(
848 btrfs_free_space_bitmap_cachep, GFP_NOFS);
849 if (!e->bitmap) {
850 ret = -ENOMEM;
851 kmem_cache_free(
852 btrfs_free_space_cachep, e);
853 goto free_cache;
854 }
855 spin_lock(&ctl->tree_lock);
856 ret = link_free_space(ctl, e);
857 if (ret) {
858 spin_unlock(&ctl->tree_lock);
859 btrfs_err(fs_info,
860 "Duplicate entries in free space cache, dumping");
861 kmem_cache_free(btrfs_free_space_bitmap_cachep, e->bitmap);
862 kmem_cache_free(btrfs_free_space_cachep, e);
863 goto free_cache;
864 }
865 ctl->total_bitmaps++;
866 recalculate_thresholds(ctl);
867 spin_unlock(&ctl->tree_lock);
868 list_add_tail(&e->list, &bitmaps);
869 }
870
871 num_entries--;
872 }
873
874 io_ctl_unmap_page(&io_ctl);
875
876 /*
877 * We add the bitmaps at the end of the entries in order that
878 * the bitmap entries are added to the cache.
879 */
880 list_for_each_entry_safe(e, n, &bitmaps, list) {
881 list_del_init(&e->list);
882 ret = io_ctl_read_bitmap(&io_ctl, e);
883 if (ret)
884 goto free_cache;
885 }
886
887 io_ctl_drop_pages(&io_ctl);
888 ret = 1;
889out:
890 io_ctl_free(&io_ctl);
891 return ret;
892free_cache:
893 io_ctl_drop_pages(&io_ctl);
894
895 spin_lock(&ctl->tree_lock);
896 __btrfs_remove_free_space_cache(ctl);
897 spin_unlock(&ctl->tree_lock);
898 goto out;
899}
900
901static int copy_free_space_cache(struct btrfs_block_group *block_group,
902 struct btrfs_free_space_ctl *ctl)
903{
904 struct btrfs_free_space *info;
905 struct rb_node *n;
906 int ret = 0;
907
908 while (!ret && (n = rb_first(&ctl->free_space_offset)) != NULL) {
909 info = rb_entry(n, struct btrfs_free_space, offset_index);
910 if (!info->bitmap) {
911 const u64 offset = info->offset;
912 const u64 bytes = info->bytes;
913
914 unlink_free_space(ctl, info, true);
915 spin_unlock(&ctl->tree_lock);
916 kmem_cache_free(btrfs_free_space_cachep, info);
917 ret = btrfs_add_free_space(block_group, offset, bytes);
918 spin_lock(&ctl->tree_lock);
919 } else {
920 u64 offset = info->offset;
921 u64 bytes = ctl->unit;
922
923 ret = search_bitmap(ctl, info, &offset, &bytes, false);
924 if (ret == 0) {
925 bitmap_clear_bits(ctl, info, offset, bytes, true);
926 spin_unlock(&ctl->tree_lock);
927 ret = btrfs_add_free_space(block_group, offset,
928 bytes);
929 spin_lock(&ctl->tree_lock);
930 } else {
931 free_bitmap(ctl, info);
932 ret = 0;
933 }
934 }
935 cond_resched_lock(&ctl->tree_lock);
936 }
937 return ret;
938}
939
940static struct lock_class_key btrfs_free_space_inode_key;
941
942int load_free_space_cache(struct btrfs_block_group *block_group)
943{
944 struct btrfs_fs_info *fs_info = block_group->fs_info;
945 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
946 struct btrfs_free_space_ctl tmp_ctl = {};
947 struct inode *inode;
948 struct btrfs_path *path;
949 int ret = 0;
950 bool matched;
951 u64 used = block_group->used;
952
953 /*
954 * Because we could potentially discard our loaded free space, we want
955 * to load everything into a temporary structure first, and then if it's
956 * valid copy it all into the actual free space ctl.
957 */
958 btrfs_init_free_space_ctl(block_group, &tmp_ctl);
959
960 /*
961 * If this block group has been marked to be cleared for one reason or
962 * another then we can't trust the on disk cache, so just return.
963 */
964 spin_lock(&block_group->lock);
965 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
966 spin_unlock(&block_group->lock);
967 return 0;
968 }
969 spin_unlock(&block_group->lock);
970
971 path = btrfs_alloc_path();
972 if (!path)
973 return 0;
974 path->search_commit_root = 1;
975 path->skip_locking = 1;
976
977 /*
978 * We must pass a path with search_commit_root set to btrfs_iget in
979 * order to avoid a deadlock when allocating extents for the tree root.
980 *
981 * When we are COWing an extent buffer from the tree root, when looking
982 * for a free extent, at extent-tree.c:find_free_extent(), we can find
983 * block group without its free space cache loaded. When we find one
984 * we must load its space cache which requires reading its free space
985 * cache's inode item from the root tree. If this inode item is located
986 * in the same leaf that we started COWing before, then we end up in
987 * deadlock on the extent buffer (trying to read lock it when we
988 * previously write locked it).
989 *
990 * It's safe to read the inode item using the commit root because
991 * block groups, once loaded, stay in memory forever (until they are
992 * removed) as well as their space caches once loaded. New block groups
993 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
994 * we will never try to read their inode item while the fs is mounted.
995 */
996 inode = lookup_free_space_inode(block_group, path);
997 if (IS_ERR(inode)) {
998 btrfs_free_path(path);
999 return 0;
1000 }
1001
1002 /* We may have converted the inode and made the cache invalid. */
1003 spin_lock(&block_group->lock);
1004 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
1005 spin_unlock(&block_group->lock);
1006 btrfs_free_path(path);
1007 goto out;
1008 }
1009 spin_unlock(&block_group->lock);
1010
1011 /*
1012 * Reinitialize the class of struct inode's mapping->invalidate_lock for
1013 * free space inodes to prevent false positives related to locks for normal
1014 * inodes.
1015 */
1016 lockdep_set_class(&(&inode->i_data)->invalidate_lock,
1017 &btrfs_free_space_inode_key);
1018
1019 ret = __load_free_space_cache(fs_info->tree_root, inode, &tmp_ctl,
1020 path, block_group->start);
1021 btrfs_free_path(path);
1022 if (ret <= 0)
1023 goto out;
1024
1025 matched = (tmp_ctl.free_space == (block_group->length - used -
1026 block_group->bytes_super));
1027
1028 if (matched) {
1029 spin_lock(&tmp_ctl.tree_lock);
1030 ret = copy_free_space_cache(block_group, &tmp_ctl);
1031 spin_unlock(&tmp_ctl.tree_lock);
1032 /*
1033 * ret == 1 means we successfully loaded the free space cache,
1034 * so we need to re-set it here.
1035 */
1036 if (ret == 0)
1037 ret = 1;
1038 } else {
1039 /*
1040 * We need to call the _locked variant so we don't try to update
1041 * the discard counters.
1042 */
1043 spin_lock(&tmp_ctl.tree_lock);
1044 __btrfs_remove_free_space_cache(&tmp_ctl);
1045 spin_unlock(&tmp_ctl.tree_lock);
1046 btrfs_warn(fs_info,
1047 "block group %llu has wrong amount of free space",
1048 block_group->start);
1049 ret = -1;
1050 }
1051out:
1052 if (ret < 0) {
1053 /* This cache is bogus, make sure it gets cleared */
1054 spin_lock(&block_group->lock);
1055 block_group->disk_cache_state = BTRFS_DC_CLEAR;
1056 spin_unlock(&block_group->lock);
1057 ret = 0;
1058
1059 btrfs_warn(fs_info,
1060 "failed to load free space cache for block group %llu, rebuilding it now",
1061 block_group->start);
1062 }
1063
1064 spin_lock(&ctl->tree_lock);
1065 btrfs_discard_update_discardable(block_group);
1066 spin_unlock(&ctl->tree_lock);
1067 iput(inode);
1068 return ret;
1069}
1070
1071static noinline_for_stack
1072int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
1073 struct btrfs_free_space_ctl *ctl,
1074 struct btrfs_block_group *block_group,
1075 int *entries, int *bitmaps,
1076 struct list_head *bitmap_list)
1077{
1078 int ret;
1079 struct btrfs_free_cluster *cluster = NULL;
1080 struct btrfs_free_cluster *cluster_locked = NULL;
1081 struct rb_node *node = rb_first(&ctl->free_space_offset);
1082 struct btrfs_trim_range *trim_entry;
1083
1084 /* Get the cluster for this block_group if it exists */
1085 if (block_group && !list_empty(&block_group->cluster_list)) {
1086 cluster = list_entry(block_group->cluster_list.next,
1087 struct btrfs_free_cluster,
1088 block_group_list);
1089 }
1090
1091 if (!node && cluster) {
1092 cluster_locked = cluster;
1093 spin_lock(&cluster_locked->lock);
1094 node = rb_first(&cluster->root);
1095 cluster = NULL;
1096 }
1097
1098 /* Write out the extent entries */
1099 while (node) {
1100 struct btrfs_free_space *e;
1101
1102 e = rb_entry(node, struct btrfs_free_space, offset_index);
1103 *entries += 1;
1104
1105 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
1106 e->bitmap);
1107 if (ret)
1108 goto fail;
1109
1110 if (e->bitmap) {
1111 list_add_tail(&e->list, bitmap_list);
1112 *bitmaps += 1;
1113 }
1114 node = rb_next(node);
1115 if (!node && cluster) {
1116 node = rb_first(&cluster->root);
1117 cluster_locked = cluster;
1118 spin_lock(&cluster_locked->lock);
1119 cluster = NULL;
1120 }
1121 }
1122 if (cluster_locked) {
1123 spin_unlock(&cluster_locked->lock);
1124 cluster_locked = NULL;
1125 }
1126
1127 /*
1128 * Make sure we don't miss any range that was removed from our rbtree
1129 * because trimming is running. Otherwise after a umount+mount (or crash
1130 * after committing the transaction) we would leak free space and get
1131 * an inconsistent free space cache report from fsck.
1132 */
1133 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
1134 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
1135 trim_entry->bytes, NULL);
1136 if (ret)
1137 goto fail;
1138 *entries += 1;
1139 }
1140
1141 return 0;
1142fail:
1143 if (cluster_locked)
1144 spin_unlock(&cluster_locked->lock);
1145 return -ENOSPC;
1146}
1147
1148static noinline_for_stack int
1149update_cache_item(struct btrfs_trans_handle *trans,
1150 struct btrfs_root *root,
1151 struct inode *inode,
1152 struct btrfs_path *path, u64 offset,
1153 int entries, int bitmaps)
1154{
1155 struct btrfs_key key;
1156 struct btrfs_free_space_header *header;
1157 struct extent_buffer *leaf;
1158 int ret;
1159
1160 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1161 key.offset = offset;
1162 key.type = 0;
1163
1164 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1165 if (ret < 0) {
1166 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1167 EXTENT_DELALLOC, NULL);
1168 goto fail;
1169 }
1170 leaf = path->nodes[0];
1171 if (ret > 0) {
1172 struct btrfs_key found_key;
1173 ASSERT(path->slots[0]);
1174 path->slots[0]--;
1175 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1176 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1177 found_key.offset != offset) {
1178 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1179 inode->i_size - 1, EXTENT_DELALLOC,
1180 NULL);
1181 btrfs_release_path(path);
1182 goto fail;
1183 }
1184 }
1185
1186 BTRFS_I(inode)->generation = trans->transid;
1187 header = btrfs_item_ptr(leaf, path->slots[0],
1188 struct btrfs_free_space_header);
1189 btrfs_set_free_space_entries(leaf, header, entries);
1190 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1191 btrfs_set_free_space_generation(leaf, header, trans->transid);
1192 btrfs_mark_buffer_dirty(trans, leaf);
1193 btrfs_release_path(path);
1194
1195 return 0;
1196
1197fail:
1198 return -1;
1199}
1200
1201static noinline_for_stack int write_pinned_extent_entries(
1202 struct btrfs_trans_handle *trans,
1203 struct btrfs_block_group *block_group,
1204 struct btrfs_io_ctl *io_ctl,
1205 int *entries)
1206{
1207 u64 start, extent_start, extent_end, len;
1208 struct extent_io_tree *unpin = NULL;
1209 int ret;
1210
1211 if (!block_group)
1212 return 0;
1213
1214 /*
1215 * We want to add any pinned extents to our free space cache
1216 * so we don't leak the space
1217 *
1218 * We shouldn't have switched the pinned extents yet so this is the
1219 * right one
1220 */
1221 unpin = &trans->transaction->pinned_extents;
1222
1223 start = block_group->start;
1224
1225 while (start < block_group->start + block_group->length) {
1226 if (!find_first_extent_bit(unpin, start,
1227 &extent_start, &extent_end,
1228 EXTENT_DIRTY, NULL))
1229 return 0;
1230
1231 /* This pinned extent is out of our range */
1232 if (extent_start >= block_group->start + block_group->length)
1233 return 0;
1234
1235 extent_start = max(extent_start, start);
1236 extent_end = min(block_group->start + block_group->length,
1237 extent_end + 1);
1238 len = extent_end - extent_start;
1239
1240 *entries += 1;
1241 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1242 if (ret)
1243 return -ENOSPC;
1244
1245 start = extent_end;
1246 }
1247
1248 return 0;
1249}
1250
1251static noinline_for_stack int
1252write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1253{
1254 struct btrfs_free_space *entry, *next;
1255 int ret;
1256
1257 /* Write out the bitmaps */
1258 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1259 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1260 if (ret)
1261 return -ENOSPC;
1262 list_del_init(&entry->list);
1263 }
1264
1265 return 0;
1266}
1267
1268static int flush_dirty_cache(struct inode *inode)
1269{
1270 int ret;
1271
1272 ret = btrfs_wait_ordered_range(BTRFS_I(inode), 0, (u64)-1);
1273 if (ret)
1274 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1275 EXTENT_DELALLOC, NULL);
1276
1277 return ret;
1278}
1279
1280static void noinline_for_stack
1281cleanup_bitmap_list(struct list_head *bitmap_list)
1282{
1283 struct btrfs_free_space *entry, *next;
1284
1285 list_for_each_entry_safe(entry, next, bitmap_list, list)
1286 list_del_init(&entry->list);
1287}
1288
1289static void noinline_for_stack
1290cleanup_write_cache_enospc(struct inode *inode,
1291 struct btrfs_io_ctl *io_ctl,
1292 struct extent_state **cached_state)
1293{
1294 io_ctl_drop_pages(io_ctl);
1295 unlock_extent(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1296 cached_state);
1297}
1298
1299static int __btrfs_wait_cache_io(struct btrfs_root *root,
1300 struct btrfs_trans_handle *trans,
1301 struct btrfs_block_group *block_group,
1302 struct btrfs_io_ctl *io_ctl,
1303 struct btrfs_path *path, u64 offset)
1304{
1305 int ret;
1306 struct inode *inode = io_ctl->inode;
1307
1308 if (!inode)
1309 return 0;
1310
1311 /* Flush the dirty pages in the cache file. */
1312 ret = flush_dirty_cache(inode);
1313 if (ret)
1314 goto out;
1315
1316 /* Update the cache item to tell everyone this cache file is valid. */
1317 ret = update_cache_item(trans, root, inode, path, offset,
1318 io_ctl->entries, io_ctl->bitmaps);
1319out:
1320 if (ret) {
1321 invalidate_inode_pages2(inode->i_mapping);
1322 BTRFS_I(inode)->generation = 0;
1323 if (block_group)
1324 btrfs_debug(root->fs_info,
1325 "failed to write free space cache for block group %llu error %d",
1326 block_group->start, ret);
1327 }
1328 btrfs_update_inode(trans, BTRFS_I(inode));
1329
1330 if (block_group) {
1331 /* the dirty list is protected by the dirty_bgs_lock */
1332 spin_lock(&trans->transaction->dirty_bgs_lock);
1333
1334 /* the disk_cache_state is protected by the block group lock */
1335 spin_lock(&block_group->lock);
1336
1337 /*
1338 * only mark this as written if we didn't get put back on
1339 * the dirty list while waiting for IO. Otherwise our
1340 * cache state won't be right, and we won't get written again
1341 */
1342 if (!ret && list_empty(&block_group->dirty_list))
1343 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1344 else if (ret)
1345 block_group->disk_cache_state = BTRFS_DC_ERROR;
1346
1347 spin_unlock(&block_group->lock);
1348 spin_unlock(&trans->transaction->dirty_bgs_lock);
1349 io_ctl->inode = NULL;
1350 iput(inode);
1351 }
1352
1353 return ret;
1354
1355}
1356
1357int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1358 struct btrfs_block_group *block_group,
1359 struct btrfs_path *path)
1360{
1361 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1362 block_group, &block_group->io_ctl,
1363 path, block_group->start);
1364}
1365
1366/*
1367 * Write out cached info to an inode.
1368 *
1369 * @inode: freespace inode we are writing out
1370 * @ctl: free space cache we are going to write out
1371 * @block_group: block_group for this cache if it belongs to a block_group
1372 * @io_ctl: holds context for the io
1373 * @trans: the trans handle
1374 *
1375 * This function writes out a free space cache struct to disk for quick recovery
1376 * on mount. This will return 0 if it was successful in writing the cache out,
1377 * or an errno if it was not.
1378 */
1379static int __btrfs_write_out_cache(struct inode *inode,
1380 struct btrfs_free_space_ctl *ctl,
1381 struct btrfs_block_group *block_group,
1382 struct btrfs_io_ctl *io_ctl,
1383 struct btrfs_trans_handle *trans)
1384{
1385 struct extent_state *cached_state = NULL;
1386 LIST_HEAD(bitmap_list);
1387 int entries = 0;
1388 int bitmaps = 0;
1389 int ret;
1390 int must_iput = 0;
1391 int i_size;
1392
1393 if (!i_size_read(inode))
1394 return -EIO;
1395
1396 WARN_ON(io_ctl->pages);
1397 ret = io_ctl_init(io_ctl, inode, 1);
1398 if (ret)
1399 return ret;
1400
1401 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1402 down_write(&block_group->data_rwsem);
1403 spin_lock(&block_group->lock);
1404 if (block_group->delalloc_bytes) {
1405 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1406 spin_unlock(&block_group->lock);
1407 up_write(&block_group->data_rwsem);
1408 BTRFS_I(inode)->generation = 0;
1409 ret = 0;
1410 must_iput = 1;
1411 goto out;
1412 }
1413 spin_unlock(&block_group->lock);
1414 }
1415
1416 /* Lock all pages first so we can lock the extent safely. */
1417 ret = io_ctl_prepare_pages(io_ctl, false);
1418 if (ret)
1419 goto out_unlock;
1420
1421 lock_extent(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1422 &cached_state);
1423
1424 io_ctl_set_generation(io_ctl, trans->transid);
1425
1426 mutex_lock(&ctl->cache_writeout_mutex);
1427 /* Write out the extent entries in the free space cache */
1428 spin_lock(&ctl->tree_lock);
1429 ret = write_cache_extent_entries(io_ctl, ctl,
1430 block_group, &entries, &bitmaps,
1431 &bitmap_list);
1432 if (ret)
1433 goto out_nospc_locked;
1434
1435 /*
1436 * Some spaces that are freed in the current transaction are pinned,
1437 * they will be added into free space cache after the transaction is
1438 * committed, we shouldn't lose them.
1439 *
1440 * If this changes while we are working we'll get added back to
1441 * the dirty list and redo it. No locking needed
1442 */
1443 ret = write_pinned_extent_entries(trans, block_group, io_ctl, &entries);
1444 if (ret)
1445 goto out_nospc_locked;
1446
1447 /*
1448 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1449 * locked while doing it because a concurrent trim can be manipulating
1450 * or freeing the bitmap.
1451 */
1452 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1453 spin_unlock(&ctl->tree_lock);
1454 mutex_unlock(&ctl->cache_writeout_mutex);
1455 if (ret)
1456 goto out_nospc;
1457
1458 /* Zero out the rest of the pages just to make sure */
1459 io_ctl_zero_remaining_pages(io_ctl);
1460
1461 /* Everything is written out, now we dirty the pages in the file. */
1462 i_size = i_size_read(inode);
1463 for (int i = 0; i < round_up(i_size, PAGE_SIZE) / PAGE_SIZE; i++) {
1464 u64 dirty_start = i * PAGE_SIZE;
1465 u64 dirty_len = min_t(u64, dirty_start + PAGE_SIZE, i_size) - dirty_start;
1466
1467 ret = btrfs_dirty_folio(BTRFS_I(inode), page_folio(io_ctl->pages[i]),
1468 dirty_start, dirty_len, &cached_state, false);
1469 if (ret < 0)
1470 goto out_nospc;
1471 }
1472
1473 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1474 up_write(&block_group->data_rwsem);
1475 /*
1476 * Release the pages and unlock the extent, we will flush
1477 * them out later
1478 */
1479 io_ctl_drop_pages(io_ctl);
1480 io_ctl_free(io_ctl);
1481
1482 unlock_extent(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1483 &cached_state);
1484
1485 /*
1486 * at this point the pages are under IO and we're happy,
1487 * The caller is responsible for waiting on them and updating
1488 * the cache and the inode
1489 */
1490 io_ctl->entries = entries;
1491 io_ctl->bitmaps = bitmaps;
1492
1493 ret = btrfs_fdatawrite_range(BTRFS_I(inode), 0, (u64)-1);
1494 if (ret)
1495 goto out;
1496
1497 return 0;
1498
1499out_nospc_locked:
1500 cleanup_bitmap_list(&bitmap_list);
1501 spin_unlock(&ctl->tree_lock);
1502 mutex_unlock(&ctl->cache_writeout_mutex);
1503
1504out_nospc:
1505 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1506
1507out_unlock:
1508 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1509 up_write(&block_group->data_rwsem);
1510
1511out:
1512 io_ctl->inode = NULL;
1513 io_ctl_free(io_ctl);
1514 if (ret) {
1515 invalidate_inode_pages2(inode->i_mapping);
1516 BTRFS_I(inode)->generation = 0;
1517 }
1518 btrfs_update_inode(trans, BTRFS_I(inode));
1519 if (must_iput)
1520 iput(inode);
1521 return ret;
1522}
1523
1524int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
1525 struct btrfs_block_group *block_group,
1526 struct btrfs_path *path)
1527{
1528 struct btrfs_fs_info *fs_info = trans->fs_info;
1529 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1530 struct inode *inode;
1531 int ret = 0;
1532
1533 spin_lock(&block_group->lock);
1534 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1535 spin_unlock(&block_group->lock);
1536 return 0;
1537 }
1538 spin_unlock(&block_group->lock);
1539
1540 inode = lookup_free_space_inode(block_group, path);
1541 if (IS_ERR(inode))
1542 return 0;
1543
1544 ret = __btrfs_write_out_cache(inode, ctl, block_group,
1545 &block_group->io_ctl, trans);
1546 if (ret) {
1547 btrfs_debug(fs_info,
1548 "failed to write free space cache for block group %llu error %d",
1549 block_group->start, ret);
1550 spin_lock(&block_group->lock);
1551 block_group->disk_cache_state = BTRFS_DC_ERROR;
1552 spin_unlock(&block_group->lock);
1553
1554 block_group->io_ctl.inode = NULL;
1555 iput(inode);
1556 }
1557
1558 /*
1559 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1560 * to wait for IO and put the inode
1561 */
1562
1563 return ret;
1564}
1565
1566static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1567 u64 offset)
1568{
1569 ASSERT(offset >= bitmap_start);
1570 offset -= bitmap_start;
1571 return (unsigned long)(div_u64(offset, unit));
1572}
1573
1574static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1575{
1576 return (unsigned long)(div_u64(bytes, unit));
1577}
1578
1579static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1580 u64 offset)
1581{
1582 u64 bitmap_start;
1583 u64 bytes_per_bitmap;
1584
1585 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1586 bitmap_start = offset - ctl->start;
1587 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1588 bitmap_start *= bytes_per_bitmap;
1589 bitmap_start += ctl->start;
1590
1591 return bitmap_start;
1592}
1593
1594static int tree_insert_offset(struct btrfs_free_space_ctl *ctl,
1595 struct btrfs_free_cluster *cluster,
1596 struct btrfs_free_space *new_entry)
1597{
1598 struct rb_root *root;
1599 struct rb_node **p;
1600 struct rb_node *parent = NULL;
1601
1602 lockdep_assert_held(&ctl->tree_lock);
1603
1604 if (cluster) {
1605 lockdep_assert_held(&cluster->lock);
1606 root = &cluster->root;
1607 } else {
1608 root = &ctl->free_space_offset;
1609 }
1610
1611 p = &root->rb_node;
1612
1613 while (*p) {
1614 struct btrfs_free_space *info;
1615
1616 parent = *p;
1617 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1618
1619 if (new_entry->offset < info->offset) {
1620 p = &(*p)->rb_left;
1621 } else if (new_entry->offset > info->offset) {
1622 p = &(*p)->rb_right;
1623 } else {
1624 /*
1625 * we could have a bitmap entry and an extent entry
1626 * share the same offset. If this is the case, we want
1627 * the extent entry to always be found first if we do a
1628 * linear search through the tree, since we want to have
1629 * the quickest allocation time, and allocating from an
1630 * extent is faster than allocating from a bitmap. So
1631 * if we're inserting a bitmap and we find an entry at
1632 * this offset, we want to go right, or after this entry
1633 * logically. If we are inserting an extent and we've
1634 * found a bitmap, we want to go left, or before
1635 * logically.
1636 */
1637 if (new_entry->bitmap) {
1638 if (info->bitmap) {
1639 WARN_ON_ONCE(1);
1640 return -EEXIST;
1641 }
1642 p = &(*p)->rb_right;
1643 } else {
1644 if (!info->bitmap) {
1645 WARN_ON_ONCE(1);
1646 return -EEXIST;
1647 }
1648 p = &(*p)->rb_left;
1649 }
1650 }
1651 }
1652
1653 rb_link_node(&new_entry->offset_index, parent, p);
1654 rb_insert_color(&new_entry->offset_index, root);
1655
1656 return 0;
1657}
1658
1659/*
1660 * This is a little subtle. We *only* have ->max_extent_size set if we actually
1661 * searched through the bitmap and figured out the largest ->max_extent_size,
1662 * otherwise it's 0. In the case that it's 0 we don't want to tell the
1663 * allocator the wrong thing, we want to use the actual real max_extent_size
1664 * we've found already if it's larger, or we want to use ->bytes.
1665 *
1666 * This matters because find_free_space() will skip entries who's ->bytes is
1667 * less than the required bytes. So if we didn't search down this bitmap, we
1668 * may pick some previous entry that has a smaller ->max_extent_size than we
1669 * have. For example, assume we have two entries, one that has
1670 * ->max_extent_size set to 4K and ->bytes set to 1M. A second entry hasn't set
1671 * ->max_extent_size yet, has ->bytes set to 8K and it's contiguous. We will
1672 * call into find_free_space(), and return with max_extent_size == 4K, because
1673 * that first bitmap entry had ->max_extent_size set, but the second one did
1674 * not. If instead we returned 8K we'd come in searching for 8K, and find the
1675 * 8K contiguous range.
1676 *
1677 * Consider the other case, we have 2 8K chunks in that second entry and still
1678 * don't have ->max_extent_size set. We'll return 16K, and the next time the
1679 * allocator comes in it'll fully search our second bitmap, and this time it'll
1680 * get an uptodate value of 8K as the maximum chunk size. Then we'll get the
1681 * right allocation the next loop through.
1682 */
1683static inline u64 get_max_extent_size(const struct btrfs_free_space *entry)
1684{
1685 if (entry->bitmap && entry->max_extent_size)
1686 return entry->max_extent_size;
1687 return entry->bytes;
1688}
1689
1690/*
1691 * We want the largest entry to be leftmost, so this is inverted from what you'd
1692 * normally expect.
1693 */
1694static bool entry_less(struct rb_node *node, const struct rb_node *parent)
1695{
1696 const struct btrfs_free_space *entry, *exist;
1697
1698 entry = rb_entry(node, struct btrfs_free_space, bytes_index);
1699 exist = rb_entry(parent, struct btrfs_free_space, bytes_index);
1700 return get_max_extent_size(exist) < get_max_extent_size(entry);
1701}
1702
1703/*
1704 * searches the tree for the given offset.
1705 *
1706 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1707 * want a section that has at least bytes size and comes at or after the given
1708 * offset.
1709 */
1710static struct btrfs_free_space *
1711tree_search_offset(struct btrfs_free_space_ctl *ctl,
1712 u64 offset, int bitmap_only, int fuzzy)
1713{
1714 struct rb_node *n = ctl->free_space_offset.rb_node;
1715 struct btrfs_free_space *entry = NULL, *prev = NULL;
1716
1717 lockdep_assert_held(&ctl->tree_lock);
1718
1719 /* find entry that is closest to the 'offset' */
1720 while (n) {
1721 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1722 prev = entry;
1723
1724 if (offset < entry->offset)
1725 n = n->rb_left;
1726 else if (offset > entry->offset)
1727 n = n->rb_right;
1728 else
1729 break;
1730
1731 entry = NULL;
1732 }
1733
1734 if (bitmap_only) {
1735 if (!entry)
1736 return NULL;
1737 if (entry->bitmap)
1738 return entry;
1739
1740 /*
1741 * bitmap entry and extent entry may share same offset,
1742 * in that case, bitmap entry comes after extent entry.
1743 */
1744 n = rb_next(n);
1745 if (!n)
1746 return NULL;
1747 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1748 if (entry->offset != offset)
1749 return NULL;
1750
1751 WARN_ON(!entry->bitmap);
1752 return entry;
1753 } else if (entry) {
1754 if (entry->bitmap) {
1755 /*
1756 * if previous extent entry covers the offset,
1757 * we should return it instead of the bitmap entry
1758 */
1759 n = rb_prev(&entry->offset_index);
1760 if (n) {
1761 prev = rb_entry(n, struct btrfs_free_space,
1762 offset_index);
1763 if (!prev->bitmap &&
1764 prev->offset + prev->bytes > offset)
1765 entry = prev;
1766 }
1767 }
1768 return entry;
1769 }
1770
1771 if (!prev)
1772 return NULL;
1773
1774 /* find last entry before the 'offset' */
1775 entry = prev;
1776 if (entry->offset > offset) {
1777 n = rb_prev(&entry->offset_index);
1778 if (n) {
1779 entry = rb_entry(n, struct btrfs_free_space,
1780 offset_index);
1781 ASSERT(entry->offset <= offset);
1782 } else {
1783 if (fuzzy)
1784 return entry;
1785 else
1786 return NULL;
1787 }
1788 }
1789
1790 if (entry->bitmap) {
1791 n = rb_prev(&entry->offset_index);
1792 if (n) {
1793 prev = rb_entry(n, struct btrfs_free_space,
1794 offset_index);
1795 if (!prev->bitmap &&
1796 prev->offset + prev->bytes > offset)
1797 return prev;
1798 }
1799 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1800 return entry;
1801 } else if (entry->offset + entry->bytes > offset)
1802 return entry;
1803
1804 if (!fuzzy)
1805 return NULL;
1806
1807 while (1) {
1808 n = rb_next(&entry->offset_index);
1809 if (!n)
1810 return NULL;
1811 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1812 if (entry->bitmap) {
1813 if (entry->offset + BITS_PER_BITMAP *
1814 ctl->unit > offset)
1815 break;
1816 } else {
1817 if (entry->offset + entry->bytes > offset)
1818 break;
1819 }
1820 }
1821 return entry;
1822}
1823
1824static inline void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1825 struct btrfs_free_space *info,
1826 bool update_stat)
1827{
1828 lockdep_assert_held(&ctl->tree_lock);
1829
1830 rb_erase(&info->offset_index, &ctl->free_space_offset);
1831 rb_erase_cached(&info->bytes_index, &ctl->free_space_bytes);
1832 ctl->free_extents--;
1833
1834 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1835 ctl->discardable_extents[BTRFS_STAT_CURR]--;
1836 ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes;
1837 }
1838
1839 if (update_stat)
1840 ctl->free_space -= info->bytes;
1841}
1842
1843static int link_free_space(struct btrfs_free_space_ctl *ctl,
1844 struct btrfs_free_space *info)
1845{
1846 int ret = 0;
1847
1848 lockdep_assert_held(&ctl->tree_lock);
1849
1850 ASSERT(info->bytes || info->bitmap);
1851 ret = tree_insert_offset(ctl, NULL, info);
1852 if (ret)
1853 return ret;
1854
1855 rb_add_cached(&info->bytes_index, &ctl->free_space_bytes, entry_less);
1856
1857 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1858 ctl->discardable_extents[BTRFS_STAT_CURR]++;
1859 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
1860 }
1861
1862 ctl->free_space += info->bytes;
1863 ctl->free_extents++;
1864 return ret;
1865}
1866
1867static void relink_bitmap_entry(struct btrfs_free_space_ctl *ctl,
1868 struct btrfs_free_space *info)
1869{
1870 ASSERT(info->bitmap);
1871
1872 /*
1873 * If our entry is empty it's because we're on a cluster and we don't
1874 * want to re-link it into our ctl bytes index.
1875 */
1876 if (RB_EMPTY_NODE(&info->bytes_index))
1877 return;
1878
1879 lockdep_assert_held(&ctl->tree_lock);
1880
1881 rb_erase_cached(&info->bytes_index, &ctl->free_space_bytes);
1882 rb_add_cached(&info->bytes_index, &ctl->free_space_bytes, entry_less);
1883}
1884
1885static inline void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1886 struct btrfs_free_space *info,
1887 u64 offset, u64 bytes, bool update_stat)
1888{
1889 unsigned long start, count, end;
1890 int extent_delta = -1;
1891
1892 start = offset_to_bit(info->offset, ctl->unit, offset);
1893 count = bytes_to_bits(bytes, ctl->unit);
1894 end = start + count;
1895 ASSERT(end <= BITS_PER_BITMAP);
1896
1897 bitmap_clear(info->bitmap, start, count);
1898
1899 info->bytes -= bytes;
1900 if (info->max_extent_size > ctl->unit)
1901 info->max_extent_size = 0;
1902
1903 relink_bitmap_entry(ctl, info);
1904
1905 if (start && test_bit(start - 1, info->bitmap))
1906 extent_delta++;
1907
1908 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1909 extent_delta++;
1910
1911 info->bitmap_extents += extent_delta;
1912 if (!btrfs_free_space_trimmed(info)) {
1913 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1914 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
1915 }
1916
1917 if (update_stat)
1918 ctl->free_space -= bytes;
1919}
1920
1921static void btrfs_bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1922 struct btrfs_free_space *info, u64 offset,
1923 u64 bytes)
1924{
1925 unsigned long start, count, end;
1926 int extent_delta = 1;
1927
1928 start = offset_to_bit(info->offset, ctl->unit, offset);
1929 count = bytes_to_bits(bytes, ctl->unit);
1930 end = start + count;
1931 ASSERT(end <= BITS_PER_BITMAP);
1932
1933 bitmap_set(info->bitmap, start, count);
1934
1935 /*
1936 * We set some bytes, we have no idea what the max extent size is
1937 * anymore.
1938 */
1939 info->max_extent_size = 0;
1940 info->bytes += bytes;
1941 ctl->free_space += bytes;
1942
1943 relink_bitmap_entry(ctl, info);
1944
1945 if (start && test_bit(start - 1, info->bitmap))
1946 extent_delta--;
1947
1948 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1949 extent_delta--;
1950
1951 info->bitmap_extents += extent_delta;
1952 if (!btrfs_free_space_trimmed(info)) {
1953 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1954 ctl->discardable_bytes[BTRFS_STAT_CURR] += bytes;
1955 }
1956}
1957
1958/*
1959 * If we can not find suitable extent, we will use bytes to record
1960 * the size of the max extent.
1961 */
1962static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1963 struct btrfs_free_space *bitmap_info, u64 *offset,
1964 u64 *bytes, bool for_alloc)
1965{
1966 unsigned long found_bits = 0;
1967 unsigned long max_bits = 0;
1968 unsigned long bits, i;
1969 unsigned long next_zero;
1970 unsigned long extent_bits;
1971
1972 /*
1973 * Skip searching the bitmap if we don't have a contiguous section that
1974 * is large enough for this allocation.
1975 */
1976 if (for_alloc &&
1977 bitmap_info->max_extent_size &&
1978 bitmap_info->max_extent_size < *bytes) {
1979 *bytes = bitmap_info->max_extent_size;
1980 return -1;
1981 }
1982
1983 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1984 max_t(u64, *offset, bitmap_info->offset));
1985 bits = bytes_to_bits(*bytes, ctl->unit);
1986
1987 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1988 if (for_alloc && bits == 1) {
1989 found_bits = 1;
1990 break;
1991 }
1992 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1993 BITS_PER_BITMAP, i);
1994 extent_bits = next_zero - i;
1995 if (extent_bits >= bits) {
1996 found_bits = extent_bits;
1997 break;
1998 } else if (extent_bits > max_bits) {
1999 max_bits = extent_bits;
2000 }
2001 i = next_zero;
2002 }
2003
2004 if (found_bits) {
2005 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
2006 *bytes = (u64)(found_bits) * ctl->unit;
2007 return 0;
2008 }
2009
2010 *bytes = (u64)(max_bits) * ctl->unit;
2011 bitmap_info->max_extent_size = *bytes;
2012 relink_bitmap_entry(ctl, bitmap_info);
2013 return -1;
2014}
2015
2016/* Cache the size of the max extent in bytes */
2017static struct btrfs_free_space *
2018find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
2019 unsigned long align, u64 *max_extent_size, bool use_bytes_index)
2020{
2021 struct btrfs_free_space *entry;
2022 struct rb_node *node;
2023 u64 tmp;
2024 u64 align_off;
2025 int ret;
2026
2027 if (!ctl->free_space_offset.rb_node)
2028 goto out;
2029again:
2030 if (use_bytes_index) {
2031 node = rb_first_cached(&ctl->free_space_bytes);
2032 } else {
2033 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset),
2034 0, 1);
2035 if (!entry)
2036 goto out;
2037 node = &entry->offset_index;
2038 }
2039
2040 for (; node; node = rb_next(node)) {
2041 if (use_bytes_index)
2042 entry = rb_entry(node, struct btrfs_free_space,
2043 bytes_index);
2044 else
2045 entry = rb_entry(node, struct btrfs_free_space,
2046 offset_index);
2047
2048 /*
2049 * If we are using the bytes index then all subsequent entries
2050 * in this tree are going to be < bytes, so simply set the max
2051 * extent size and exit the loop.
2052 *
2053 * If we're using the offset index then we need to keep going
2054 * through the rest of the tree.
2055 */
2056 if (entry->bytes < *bytes) {
2057 *max_extent_size = max(get_max_extent_size(entry),
2058 *max_extent_size);
2059 if (use_bytes_index)
2060 break;
2061 continue;
2062 }
2063
2064 /* make sure the space returned is big enough
2065 * to match our requested alignment
2066 */
2067 if (*bytes >= align) {
2068 tmp = entry->offset - ctl->start + align - 1;
2069 tmp = div64_u64(tmp, align);
2070 tmp = tmp * align + ctl->start;
2071 align_off = tmp - entry->offset;
2072 } else {
2073 align_off = 0;
2074 tmp = entry->offset;
2075 }
2076
2077 /*
2078 * We don't break here if we're using the bytes index because we
2079 * may have another entry that has the correct alignment that is
2080 * the right size, so we don't want to miss that possibility.
2081 * At worst this adds another loop through the logic, but if we
2082 * broke here we could prematurely ENOSPC.
2083 */
2084 if (entry->bytes < *bytes + align_off) {
2085 *max_extent_size = max(get_max_extent_size(entry),
2086 *max_extent_size);
2087 continue;
2088 }
2089
2090 if (entry->bitmap) {
2091 struct rb_node *old_next = rb_next(node);
2092 u64 size = *bytes;
2093
2094 ret = search_bitmap(ctl, entry, &tmp, &size, true);
2095 if (!ret) {
2096 *offset = tmp;
2097 *bytes = size;
2098 return entry;
2099 } else {
2100 *max_extent_size =
2101 max(get_max_extent_size(entry),
2102 *max_extent_size);
2103 }
2104
2105 /*
2106 * The bitmap may have gotten re-arranged in the space
2107 * index here because the max_extent_size may have been
2108 * updated. Start from the beginning again if this
2109 * happened.
2110 */
2111 if (use_bytes_index && old_next != rb_next(node))
2112 goto again;
2113 continue;
2114 }
2115
2116 *offset = tmp;
2117 *bytes = entry->bytes - align_off;
2118 return entry;
2119 }
2120out:
2121 return NULL;
2122}
2123
2124static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
2125 struct btrfs_free_space *info, u64 offset)
2126{
2127 info->offset = offset_to_bitmap(ctl, offset);
2128 info->bytes = 0;
2129 info->bitmap_extents = 0;
2130 INIT_LIST_HEAD(&info->list);
2131 link_free_space(ctl, info);
2132 ctl->total_bitmaps++;
2133 recalculate_thresholds(ctl);
2134}
2135
2136static void free_bitmap(struct btrfs_free_space_ctl *ctl,
2137 struct btrfs_free_space *bitmap_info)
2138{
2139 /*
2140 * Normally when this is called, the bitmap is completely empty. However,
2141 * if we are blowing up the free space cache for one reason or another
2142 * via __btrfs_remove_free_space_cache(), then it may not be freed and
2143 * we may leave stats on the table.
2144 */
2145 if (bitmap_info->bytes && !btrfs_free_space_trimmed(bitmap_info)) {
2146 ctl->discardable_extents[BTRFS_STAT_CURR] -=
2147 bitmap_info->bitmap_extents;
2148 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bitmap_info->bytes;
2149
2150 }
2151 unlink_free_space(ctl, bitmap_info, true);
2152 kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
2153 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
2154 ctl->total_bitmaps--;
2155 recalculate_thresholds(ctl);
2156}
2157
2158static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
2159 struct btrfs_free_space *bitmap_info,
2160 u64 *offset, u64 *bytes)
2161{
2162 u64 end;
2163 u64 search_start, search_bytes;
2164 int ret;
2165
2166again:
2167 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
2168
2169 /*
2170 * We need to search for bits in this bitmap. We could only cover some
2171 * of the extent in this bitmap thanks to how we add space, so we need
2172 * to search for as much as it as we can and clear that amount, and then
2173 * go searching for the next bit.
2174 */
2175 search_start = *offset;
2176 search_bytes = ctl->unit;
2177 search_bytes = min(search_bytes, end - search_start + 1);
2178 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
2179 false);
2180 if (ret < 0 || search_start != *offset)
2181 return -EINVAL;
2182
2183 /* We may have found more bits than what we need */
2184 search_bytes = min(search_bytes, *bytes);
2185
2186 /* Cannot clear past the end of the bitmap */
2187 search_bytes = min(search_bytes, end - search_start + 1);
2188
2189 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes, true);
2190 *offset += search_bytes;
2191 *bytes -= search_bytes;
2192
2193 if (*bytes) {
2194 struct rb_node *next = rb_next(&bitmap_info->offset_index);
2195 if (!bitmap_info->bytes)
2196 free_bitmap(ctl, bitmap_info);
2197
2198 /*
2199 * no entry after this bitmap, but we still have bytes to
2200 * remove, so something has gone wrong.
2201 */
2202 if (!next)
2203 return -EINVAL;
2204
2205 bitmap_info = rb_entry(next, struct btrfs_free_space,
2206 offset_index);
2207
2208 /*
2209 * if the next entry isn't a bitmap we need to return to let the
2210 * extent stuff do its work.
2211 */
2212 if (!bitmap_info->bitmap)
2213 return -EAGAIN;
2214
2215 /*
2216 * Ok the next item is a bitmap, but it may not actually hold
2217 * the information for the rest of this free space stuff, so
2218 * look for it, and if we don't find it return so we can try
2219 * everything over again.
2220 */
2221 search_start = *offset;
2222 search_bytes = ctl->unit;
2223 ret = search_bitmap(ctl, bitmap_info, &search_start,
2224 &search_bytes, false);
2225 if (ret < 0 || search_start != *offset)
2226 return -EAGAIN;
2227
2228 goto again;
2229 } else if (!bitmap_info->bytes)
2230 free_bitmap(ctl, bitmap_info);
2231
2232 return 0;
2233}
2234
2235static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
2236 struct btrfs_free_space *info, u64 offset,
2237 u64 bytes, enum btrfs_trim_state trim_state)
2238{
2239 u64 bytes_to_set = 0;
2240 u64 end;
2241
2242 /*
2243 * This is a tradeoff to make bitmap trim state minimal. We mark the
2244 * whole bitmap untrimmed if at any point we add untrimmed regions.
2245 */
2246 if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) {
2247 if (btrfs_free_space_trimmed(info)) {
2248 ctl->discardable_extents[BTRFS_STAT_CURR] +=
2249 info->bitmap_extents;
2250 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
2251 }
2252 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2253 }
2254
2255 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
2256
2257 bytes_to_set = min(end - offset, bytes);
2258
2259 btrfs_bitmap_set_bits(ctl, info, offset, bytes_to_set);
2260
2261 return bytes_to_set;
2262
2263}
2264
2265static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
2266 struct btrfs_free_space *info)
2267{
2268 struct btrfs_block_group *block_group = ctl->block_group;
2269 struct btrfs_fs_info *fs_info = block_group->fs_info;
2270 bool forced = false;
2271
2272#ifdef CONFIG_BTRFS_DEBUG
2273 if (btrfs_should_fragment_free_space(block_group))
2274 forced = true;
2275#endif
2276
2277 /* This is a way to reclaim large regions from the bitmaps. */
2278 if (!forced && info->bytes >= FORCE_EXTENT_THRESHOLD)
2279 return false;
2280
2281 /*
2282 * If we are below the extents threshold then we can add this as an
2283 * extent, and don't have to deal with the bitmap
2284 */
2285 if (!forced && ctl->free_extents < ctl->extents_thresh) {
2286 /*
2287 * If this block group has some small extents we don't want to
2288 * use up all of our free slots in the cache with them, we want
2289 * to reserve them to larger extents, however if we have plenty
2290 * of cache left then go ahead an dadd them, no sense in adding
2291 * the overhead of a bitmap if we don't have to.
2292 */
2293 if (info->bytes <= fs_info->sectorsize * 8) {
2294 if (ctl->free_extents * 3 <= ctl->extents_thresh)
2295 return false;
2296 } else {
2297 return false;
2298 }
2299 }
2300
2301 /*
2302 * The original block groups from mkfs can be really small, like 8
2303 * megabytes, so don't bother with a bitmap for those entries. However
2304 * some block groups can be smaller than what a bitmap would cover but
2305 * are still large enough that they could overflow the 32k memory limit,
2306 * so allow those block groups to still be allowed to have a bitmap
2307 * entry.
2308 */
2309 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->length)
2310 return false;
2311
2312 return true;
2313}
2314
2315static const struct btrfs_free_space_op free_space_op = {
2316 .use_bitmap = use_bitmap,
2317};
2318
2319static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2320 struct btrfs_free_space *info)
2321{
2322 struct btrfs_free_space *bitmap_info;
2323 struct btrfs_block_group *block_group = NULL;
2324 int added = 0;
2325 u64 bytes, offset, bytes_added;
2326 enum btrfs_trim_state trim_state;
2327 int ret;
2328
2329 bytes = info->bytes;
2330 offset = info->offset;
2331 trim_state = info->trim_state;
2332
2333 if (!ctl->op->use_bitmap(ctl, info))
2334 return 0;
2335
2336 if (ctl->op == &free_space_op)
2337 block_group = ctl->block_group;
2338again:
2339 /*
2340 * Since we link bitmaps right into the cluster we need to see if we
2341 * have a cluster here, and if so and it has our bitmap we need to add
2342 * the free space to that bitmap.
2343 */
2344 if (block_group && !list_empty(&block_group->cluster_list)) {
2345 struct btrfs_free_cluster *cluster;
2346 struct rb_node *node;
2347 struct btrfs_free_space *entry;
2348
2349 cluster = list_entry(block_group->cluster_list.next,
2350 struct btrfs_free_cluster,
2351 block_group_list);
2352 spin_lock(&cluster->lock);
2353 node = rb_first(&cluster->root);
2354 if (!node) {
2355 spin_unlock(&cluster->lock);
2356 goto no_cluster_bitmap;
2357 }
2358
2359 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2360 if (!entry->bitmap) {
2361 spin_unlock(&cluster->lock);
2362 goto no_cluster_bitmap;
2363 }
2364
2365 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2366 bytes_added = add_bytes_to_bitmap(ctl, entry, offset,
2367 bytes, trim_state);
2368 bytes -= bytes_added;
2369 offset += bytes_added;
2370 }
2371 spin_unlock(&cluster->lock);
2372 if (!bytes) {
2373 ret = 1;
2374 goto out;
2375 }
2376 }
2377
2378no_cluster_bitmap:
2379 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2380 1, 0);
2381 if (!bitmap_info) {
2382 ASSERT(added == 0);
2383 goto new_bitmap;
2384 }
2385
2386 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
2387 trim_state);
2388 bytes -= bytes_added;
2389 offset += bytes_added;
2390 added = 0;
2391
2392 if (!bytes) {
2393 ret = 1;
2394 goto out;
2395 } else
2396 goto again;
2397
2398new_bitmap:
2399 if (info && info->bitmap) {
2400 add_new_bitmap(ctl, info, offset);
2401 added = 1;
2402 info = NULL;
2403 goto again;
2404 } else {
2405 spin_unlock(&ctl->tree_lock);
2406
2407 /* no pre-allocated info, allocate a new one */
2408 if (!info) {
2409 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2410 GFP_NOFS);
2411 if (!info) {
2412 spin_lock(&ctl->tree_lock);
2413 ret = -ENOMEM;
2414 goto out;
2415 }
2416 }
2417
2418 /* allocate the bitmap */
2419 info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
2420 GFP_NOFS);
2421 info->trim_state = BTRFS_TRIM_STATE_TRIMMED;
2422 spin_lock(&ctl->tree_lock);
2423 if (!info->bitmap) {
2424 ret = -ENOMEM;
2425 goto out;
2426 }
2427 goto again;
2428 }
2429
2430out:
2431 if (info) {
2432 if (info->bitmap)
2433 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2434 info->bitmap);
2435 kmem_cache_free(btrfs_free_space_cachep, info);
2436 }
2437
2438 return ret;
2439}
2440
2441/*
2442 * Free space merging rules:
2443 * 1) Merge trimmed areas together
2444 * 2) Let untrimmed areas coalesce with trimmed areas
2445 * 3) Always pull neighboring regions from bitmaps
2446 *
2447 * The above rules are for when we merge free space based on btrfs_trim_state.
2448 * Rules 2 and 3 are subtle because they are suboptimal, but are done for the
2449 * same reason: to promote larger extent regions which makes life easier for
2450 * find_free_extent(). Rule 2 enables coalescing based on the common path
2451 * being returning free space from btrfs_finish_extent_commit(). So when free
2452 * space is trimmed, it will prevent aggregating trimmed new region and
2453 * untrimmed regions in the rb_tree. Rule 3 is purely to obtain larger extents
2454 * and provide find_free_extent() with the largest extents possible hoping for
2455 * the reuse path.
2456 */
2457static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2458 struct btrfs_free_space *info, bool update_stat)
2459{
2460 struct btrfs_free_space *left_info = NULL;
2461 struct btrfs_free_space *right_info;
2462 bool merged = false;
2463 u64 offset = info->offset;
2464 u64 bytes = info->bytes;
2465 const bool is_trimmed = btrfs_free_space_trimmed(info);
2466 struct rb_node *right_prev = NULL;
2467
2468 /*
2469 * first we want to see if there is free space adjacent to the range we
2470 * are adding, if there is remove that struct and add a new one to
2471 * cover the entire range
2472 */
2473 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2474 if (right_info)
2475 right_prev = rb_prev(&right_info->offset_index);
2476
2477 if (right_prev)
2478 left_info = rb_entry(right_prev, struct btrfs_free_space, offset_index);
2479 else if (!right_info)
2480 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2481
2482 /* See try_merge_free_space() comment. */
2483 if (right_info && !right_info->bitmap &&
2484 (!is_trimmed || btrfs_free_space_trimmed(right_info))) {
2485 unlink_free_space(ctl, right_info, update_stat);
2486 info->bytes += right_info->bytes;
2487 kmem_cache_free(btrfs_free_space_cachep, right_info);
2488 merged = true;
2489 }
2490
2491 /* See try_merge_free_space() comment. */
2492 if (left_info && !left_info->bitmap &&
2493 left_info->offset + left_info->bytes == offset &&
2494 (!is_trimmed || btrfs_free_space_trimmed(left_info))) {
2495 unlink_free_space(ctl, left_info, update_stat);
2496 info->offset = left_info->offset;
2497 info->bytes += left_info->bytes;
2498 kmem_cache_free(btrfs_free_space_cachep, left_info);
2499 merged = true;
2500 }
2501
2502 return merged;
2503}
2504
2505static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2506 struct btrfs_free_space *info,
2507 bool update_stat)
2508{
2509 struct btrfs_free_space *bitmap;
2510 unsigned long i;
2511 unsigned long j;
2512 const u64 end = info->offset + info->bytes;
2513 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2514 u64 bytes;
2515
2516 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2517 if (!bitmap)
2518 return false;
2519
2520 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2521 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2522 if (j == i)
2523 return false;
2524 bytes = (j - i) * ctl->unit;
2525 info->bytes += bytes;
2526
2527 /* See try_merge_free_space() comment. */
2528 if (!btrfs_free_space_trimmed(bitmap))
2529 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2530
2531 bitmap_clear_bits(ctl, bitmap, end, bytes, update_stat);
2532
2533 if (!bitmap->bytes)
2534 free_bitmap(ctl, bitmap);
2535
2536 return true;
2537}
2538
2539static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2540 struct btrfs_free_space *info,
2541 bool update_stat)
2542{
2543 struct btrfs_free_space *bitmap;
2544 u64 bitmap_offset;
2545 unsigned long i;
2546 unsigned long j;
2547 unsigned long prev_j;
2548 u64 bytes;
2549
2550 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2551 /* If we're on a boundary, try the previous logical bitmap. */
2552 if (bitmap_offset == info->offset) {
2553 if (info->offset == 0)
2554 return false;
2555 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2556 }
2557
2558 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2559 if (!bitmap)
2560 return false;
2561
2562 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2563 j = 0;
2564 prev_j = (unsigned long)-1;
2565 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2566 if (j > i)
2567 break;
2568 prev_j = j;
2569 }
2570 if (prev_j == i)
2571 return false;
2572
2573 if (prev_j == (unsigned long)-1)
2574 bytes = (i + 1) * ctl->unit;
2575 else
2576 bytes = (i - prev_j) * ctl->unit;
2577
2578 info->offset -= bytes;
2579 info->bytes += bytes;
2580
2581 /* See try_merge_free_space() comment. */
2582 if (!btrfs_free_space_trimmed(bitmap))
2583 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2584
2585 bitmap_clear_bits(ctl, bitmap, info->offset, bytes, update_stat);
2586
2587 if (!bitmap->bytes)
2588 free_bitmap(ctl, bitmap);
2589
2590 return true;
2591}
2592
2593/*
2594 * We prefer always to allocate from extent entries, both for clustered and
2595 * non-clustered allocation requests. So when attempting to add a new extent
2596 * entry, try to see if there's adjacent free space in bitmap entries, and if
2597 * there is, migrate that space from the bitmaps to the extent.
2598 * Like this we get better chances of satisfying space allocation requests
2599 * because we attempt to satisfy them based on a single cache entry, and never
2600 * on 2 or more entries - even if the entries represent a contiguous free space
2601 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2602 * ends).
2603 */
2604static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2605 struct btrfs_free_space *info,
2606 bool update_stat)
2607{
2608 /*
2609 * Only work with disconnected entries, as we can change their offset,
2610 * and must be extent entries.
2611 */
2612 ASSERT(!info->bitmap);
2613 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2614
2615 if (ctl->total_bitmaps > 0) {
2616 bool stole_end;
2617 bool stole_front = false;
2618
2619 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2620 if (ctl->total_bitmaps > 0)
2621 stole_front = steal_from_bitmap_to_front(ctl, info,
2622 update_stat);
2623
2624 if (stole_end || stole_front)
2625 try_merge_free_space(ctl, info, update_stat);
2626 }
2627}
2628
2629static int __btrfs_add_free_space(struct btrfs_block_group *block_group,
2630 u64 offset, u64 bytes,
2631 enum btrfs_trim_state trim_state)
2632{
2633 struct btrfs_fs_info *fs_info = block_group->fs_info;
2634 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2635 struct btrfs_free_space *info;
2636 int ret = 0;
2637 u64 filter_bytes = bytes;
2638
2639 ASSERT(!btrfs_is_zoned(fs_info));
2640
2641 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2642 if (!info)
2643 return -ENOMEM;
2644
2645 info->offset = offset;
2646 info->bytes = bytes;
2647 info->trim_state = trim_state;
2648 RB_CLEAR_NODE(&info->offset_index);
2649 RB_CLEAR_NODE(&info->bytes_index);
2650
2651 spin_lock(&ctl->tree_lock);
2652
2653 if (try_merge_free_space(ctl, info, true))
2654 goto link;
2655
2656 /*
2657 * There was no extent directly to the left or right of this new
2658 * extent then we know we're going to have to allocate a new extent, so
2659 * before we do that see if we need to drop this into a bitmap
2660 */
2661 ret = insert_into_bitmap(ctl, info);
2662 if (ret < 0) {
2663 goto out;
2664 } else if (ret) {
2665 ret = 0;
2666 goto out;
2667 }
2668link:
2669 /*
2670 * Only steal free space from adjacent bitmaps if we're sure we're not
2671 * going to add the new free space to existing bitmap entries - because
2672 * that would mean unnecessary work that would be reverted. Therefore
2673 * attempt to steal space from bitmaps if we're adding an extent entry.
2674 */
2675 steal_from_bitmap(ctl, info, true);
2676
2677 filter_bytes = max(filter_bytes, info->bytes);
2678
2679 ret = link_free_space(ctl, info);
2680 if (ret)
2681 kmem_cache_free(btrfs_free_space_cachep, info);
2682out:
2683 btrfs_discard_update_discardable(block_group);
2684 spin_unlock(&ctl->tree_lock);
2685
2686 if (ret) {
2687 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2688 ASSERT(ret != -EEXIST);
2689 }
2690
2691 if (trim_state != BTRFS_TRIM_STATE_TRIMMED) {
2692 btrfs_discard_check_filter(block_group, filter_bytes);
2693 btrfs_discard_queue_work(&fs_info->discard_ctl, block_group);
2694 }
2695
2696 return ret;
2697}
2698
2699static int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
2700 u64 bytenr, u64 size, bool used)
2701{
2702 struct btrfs_space_info *sinfo = block_group->space_info;
2703 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2704 u64 offset = bytenr - block_group->start;
2705 u64 to_free, to_unusable;
2706 int bg_reclaim_threshold = 0;
2707 bool initial;
2708 u64 reclaimable_unusable;
2709
2710 spin_lock(&block_group->lock);
2711
2712 initial = ((size == block_group->length) && (block_group->alloc_offset == 0));
2713 WARN_ON(!initial && offset + size > block_group->zone_capacity);
2714 if (!initial)
2715 bg_reclaim_threshold = READ_ONCE(sinfo->bg_reclaim_threshold);
2716
2717 if (!used)
2718 to_free = size;
2719 else if (initial)
2720 to_free = block_group->zone_capacity;
2721 else if (offset >= block_group->alloc_offset)
2722 to_free = size;
2723 else if (offset + size <= block_group->alloc_offset)
2724 to_free = 0;
2725 else
2726 to_free = offset + size - block_group->alloc_offset;
2727 to_unusable = size - to_free;
2728
2729 spin_lock(&ctl->tree_lock);
2730 ctl->free_space += to_free;
2731 spin_unlock(&ctl->tree_lock);
2732 /*
2733 * If the block group is read-only, we should account freed space into
2734 * bytes_readonly.
2735 */
2736 if (!block_group->ro) {
2737 block_group->zone_unusable += to_unusable;
2738 WARN_ON(block_group->zone_unusable > block_group->length);
2739 }
2740 if (!used) {
2741 block_group->alloc_offset -= size;
2742 }
2743
2744 reclaimable_unusable = block_group->zone_unusable -
2745 (block_group->length - block_group->zone_capacity);
2746 /* All the region is now unusable. Mark it as unused and reclaim */
2747 if (block_group->zone_unusable == block_group->length) {
2748 btrfs_mark_bg_unused(block_group);
2749 } else if (bg_reclaim_threshold &&
2750 reclaimable_unusable >=
2751 mult_perc(block_group->zone_capacity, bg_reclaim_threshold)) {
2752 btrfs_mark_bg_to_reclaim(block_group);
2753 }
2754
2755 spin_unlock(&block_group->lock);
2756
2757 return 0;
2758}
2759
2760int btrfs_add_free_space(struct btrfs_block_group *block_group,
2761 u64 bytenr, u64 size)
2762{
2763 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2764
2765 if (btrfs_is_zoned(block_group->fs_info))
2766 return __btrfs_add_free_space_zoned(block_group, bytenr, size,
2767 true);
2768
2769 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
2770 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2771
2772 return __btrfs_add_free_space(block_group, bytenr, size, trim_state);
2773}
2774
2775int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
2776 u64 bytenr, u64 size)
2777{
2778 if (btrfs_is_zoned(block_group->fs_info))
2779 return __btrfs_add_free_space_zoned(block_group, bytenr, size,
2780 false);
2781
2782 return btrfs_add_free_space(block_group, bytenr, size);
2783}
2784
2785/*
2786 * This is a subtle distinction because when adding free space back in general,
2787 * we want it to be added as untrimmed for async. But in the case where we add
2788 * it on loading of a block group, we want to consider it trimmed.
2789 */
2790int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
2791 u64 bytenr, u64 size)
2792{
2793 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2794
2795 if (btrfs_is_zoned(block_group->fs_info))
2796 return __btrfs_add_free_space_zoned(block_group, bytenr, size,
2797 true);
2798
2799 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) ||
2800 btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
2801 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2802
2803 return __btrfs_add_free_space(block_group, bytenr, size, trim_state);
2804}
2805
2806int btrfs_remove_free_space(struct btrfs_block_group *block_group,
2807 u64 offset, u64 bytes)
2808{
2809 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2810 struct btrfs_free_space *info;
2811 int ret;
2812 bool re_search = false;
2813
2814 if (btrfs_is_zoned(block_group->fs_info)) {
2815 /*
2816 * This can happen with conventional zones when replaying log.
2817 * Since the allocation info of tree-log nodes are not recorded
2818 * to the extent-tree, calculate_alloc_pointer() failed to
2819 * advance the allocation pointer after last allocated tree log
2820 * node blocks.
2821 *
2822 * This function is called from
2823 * btrfs_pin_extent_for_log_replay() when replaying the log.
2824 * Advance the pointer not to overwrite the tree-log nodes.
2825 */
2826 if (block_group->start + block_group->alloc_offset <
2827 offset + bytes) {
2828 block_group->alloc_offset =
2829 offset + bytes - block_group->start;
2830 }
2831 return 0;
2832 }
2833
2834 spin_lock(&ctl->tree_lock);
2835
2836again:
2837 ret = 0;
2838 if (!bytes)
2839 goto out_lock;
2840
2841 info = tree_search_offset(ctl, offset, 0, 0);
2842 if (!info) {
2843 /*
2844 * oops didn't find an extent that matched the space we wanted
2845 * to remove, look for a bitmap instead
2846 */
2847 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2848 1, 0);
2849 if (!info) {
2850 /*
2851 * If we found a partial bit of our free space in a
2852 * bitmap but then couldn't find the other part this may
2853 * be a problem, so WARN about it.
2854 */
2855 WARN_ON(re_search);
2856 goto out_lock;
2857 }
2858 }
2859
2860 re_search = false;
2861 if (!info->bitmap) {
2862 unlink_free_space(ctl, info, true);
2863 if (offset == info->offset) {
2864 u64 to_free = min(bytes, info->bytes);
2865
2866 info->bytes -= to_free;
2867 info->offset += to_free;
2868 if (info->bytes) {
2869 ret = link_free_space(ctl, info);
2870 WARN_ON(ret);
2871 } else {
2872 kmem_cache_free(btrfs_free_space_cachep, info);
2873 }
2874
2875 offset += to_free;
2876 bytes -= to_free;
2877 goto again;
2878 } else {
2879 u64 old_end = info->bytes + info->offset;
2880
2881 info->bytes = offset - info->offset;
2882 ret = link_free_space(ctl, info);
2883 WARN_ON(ret);
2884 if (ret)
2885 goto out_lock;
2886
2887 /* Not enough bytes in this entry to satisfy us */
2888 if (old_end < offset + bytes) {
2889 bytes -= old_end - offset;
2890 offset = old_end;
2891 goto again;
2892 } else if (old_end == offset + bytes) {
2893 /* all done */
2894 goto out_lock;
2895 }
2896 spin_unlock(&ctl->tree_lock);
2897
2898 ret = __btrfs_add_free_space(block_group,
2899 offset + bytes,
2900 old_end - (offset + bytes),
2901 info->trim_state);
2902 WARN_ON(ret);
2903 goto out;
2904 }
2905 }
2906
2907 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2908 if (ret == -EAGAIN) {
2909 re_search = true;
2910 goto again;
2911 }
2912out_lock:
2913 btrfs_discard_update_discardable(block_group);
2914 spin_unlock(&ctl->tree_lock);
2915out:
2916 return ret;
2917}
2918
2919void btrfs_dump_free_space(struct btrfs_block_group *block_group,
2920 u64 bytes)
2921{
2922 struct btrfs_fs_info *fs_info = block_group->fs_info;
2923 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2924 struct btrfs_free_space *info;
2925 struct rb_node *n;
2926 int count = 0;
2927
2928 /*
2929 * Zoned btrfs does not use free space tree and cluster. Just print
2930 * out the free space after the allocation offset.
2931 */
2932 if (btrfs_is_zoned(fs_info)) {
2933 btrfs_info(fs_info, "free space %llu active %d",
2934 block_group->zone_capacity - block_group->alloc_offset,
2935 test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
2936 &block_group->runtime_flags));
2937 return;
2938 }
2939
2940 spin_lock(&ctl->tree_lock);
2941 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2942 info = rb_entry(n, struct btrfs_free_space, offset_index);
2943 if (info->bytes >= bytes && !block_group->ro)
2944 count++;
2945 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2946 info->offset, info->bytes, str_yes_no(info->bitmap));
2947 }
2948 spin_unlock(&ctl->tree_lock);
2949 btrfs_info(fs_info, "block group has cluster?: %s",
2950 str_no_yes(list_empty(&block_group->cluster_list)));
2951 btrfs_info(fs_info,
2952 "%d free space entries at or bigger than %llu bytes",
2953 count, bytes);
2954}
2955
2956void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group,
2957 struct btrfs_free_space_ctl *ctl)
2958{
2959 struct btrfs_fs_info *fs_info = block_group->fs_info;
2960
2961 spin_lock_init(&ctl->tree_lock);
2962 ctl->unit = fs_info->sectorsize;
2963 ctl->start = block_group->start;
2964 ctl->block_group = block_group;
2965 ctl->op = &free_space_op;
2966 ctl->free_space_bytes = RB_ROOT_CACHED;
2967 INIT_LIST_HEAD(&ctl->trimming_ranges);
2968 mutex_init(&ctl->cache_writeout_mutex);
2969
2970 /*
2971 * we only want to have 32k of ram per block group for keeping
2972 * track of free space, and if we pass 1/2 of that we want to
2973 * start converting things over to using bitmaps
2974 */
2975 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2976}
2977
2978/*
2979 * for a given cluster, put all of its extents back into the free
2980 * space cache. If the block group passed doesn't match the block group
2981 * pointed to by the cluster, someone else raced in and freed the
2982 * cluster already. In that case, we just return without changing anything
2983 */
2984static void __btrfs_return_cluster_to_free_space(
2985 struct btrfs_block_group *block_group,
2986 struct btrfs_free_cluster *cluster)
2987{
2988 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2989 struct rb_node *node;
2990
2991 lockdep_assert_held(&ctl->tree_lock);
2992
2993 spin_lock(&cluster->lock);
2994 if (cluster->block_group != block_group) {
2995 spin_unlock(&cluster->lock);
2996 return;
2997 }
2998
2999 cluster->block_group = NULL;
3000 cluster->window_start = 0;
3001 list_del_init(&cluster->block_group_list);
3002
3003 node = rb_first(&cluster->root);
3004 while (node) {
3005 struct btrfs_free_space *entry;
3006
3007 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3008 node = rb_next(&entry->offset_index);
3009 rb_erase(&entry->offset_index, &cluster->root);
3010 RB_CLEAR_NODE(&entry->offset_index);
3011
3012 if (!entry->bitmap) {
3013 /* Merging treats extents as if they were new */
3014 if (!btrfs_free_space_trimmed(entry)) {
3015 ctl->discardable_extents[BTRFS_STAT_CURR]--;
3016 ctl->discardable_bytes[BTRFS_STAT_CURR] -=
3017 entry->bytes;
3018 }
3019
3020 try_merge_free_space(ctl, entry, false);
3021 steal_from_bitmap(ctl, entry, false);
3022
3023 /* As we insert directly, update these statistics */
3024 if (!btrfs_free_space_trimmed(entry)) {
3025 ctl->discardable_extents[BTRFS_STAT_CURR]++;
3026 ctl->discardable_bytes[BTRFS_STAT_CURR] +=
3027 entry->bytes;
3028 }
3029 }
3030 tree_insert_offset(ctl, NULL, entry);
3031 rb_add_cached(&entry->bytes_index, &ctl->free_space_bytes,
3032 entry_less);
3033 }
3034 cluster->root = RB_ROOT;
3035 spin_unlock(&cluster->lock);
3036 btrfs_put_block_group(block_group);
3037}
3038
3039void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group)
3040{
3041 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3042 struct btrfs_free_cluster *cluster;
3043 struct list_head *head;
3044
3045 spin_lock(&ctl->tree_lock);
3046 while ((head = block_group->cluster_list.next) !=
3047 &block_group->cluster_list) {
3048 cluster = list_entry(head, struct btrfs_free_cluster,
3049 block_group_list);
3050
3051 WARN_ON(cluster->block_group != block_group);
3052 __btrfs_return_cluster_to_free_space(block_group, cluster);
3053
3054 cond_resched_lock(&ctl->tree_lock);
3055 }
3056 __btrfs_remove_free_space_cache(ctl);
3057 btrfs_discard_update_discardable(block_group);
3058 spin_unlock(&ctl->tree_lock);
3059
3060}
3061
3062/*
3063 * Walk @block_group's free space rb_tree to determine if everything is trimmed.
3064 */
3065bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group)
3066{
3067 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3068 struct btrfs_free_space *info;
3069 struct rb_node *node;
3070 bool ret = true;
3071
3072 spin_lock(&ctl->tree_lock);
3073 node = rb_first(&ctl->free_space_offset);
3074
3075 while (node) {
3076 info = rb_entry(node, struct btrfs_free_space, offset_index);
3077
3078 if (!btrfs_free_space_trimmed(info)) {
3079 ret = false;
3080 break;
3081 }
3082
3083 node = rb_next(node);
3084 }
3085
3086 spin_unlock(&ctl->tree_lock);
3087 return ret;
3088}
3089
3090u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
3091 u64 offset, u64 bytes, u64 empty_size,
3092 u64 *max_extent_size)
3093{
3094 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3095 struct btrfs_discard_ctl *discard_ctl =
3096 &block_group->fs_info->discard_ctl;
3097 struct btrfs_free_space *entry = NULL;
3098 u64 bytes_search = bytes + empty_size;
3099 u64 ret = 0;
3100 u64 align_gap = 0;
3101 u64 align_gap_len = 0;
3102 enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3103 bool use_bytes_index = (offset == block_group->start);
3104
3105 ASSERT(!btrfs_is_zoned(block_group->fs_info));
3106
3107 spin_lock(&ctl->tree_lock);
3108 entry = find_free_space(ctl, &offset, &bytes_search,
3109 block_group->full_stripe_len, max_extent_size,
3110 use_bytes_index);
3111 if (!entry)
3112 goto out;
3113
3114 ret = offset;
3115 if (entry->bitmap) {
3116 bitmap_clear_bits(ctl, entry, offset, bytes, true);
3117
3118 if (!btrfs_free_space_trimmed(entry))
3119 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3120
3121 if (!entry->bytes)
3122 free_bitmap(ctl, entry);
3123 } else {
3124 unlink_free_space(ctl, entry, true);
3125 align_gap_len = offset - entry->offset;
3126 align_gap = entry->offset;
3127 align_gap_trim_state = entry->trim_state;
3128
3129 if (!btrfs_free_space_trimmed(entry))
3130 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3131
3132 entry->offset = offset + bytes;
3133 WARN_ON(entry->bytes < bytes + align_gap_len);
3134
3135 entry->bytes -= bytes + align_gap_len;
3136 if (!entry->bytes)
3137 kmem_cache_free(btrfs_free_space_cachep, entry);
3138 else
3139 link_free_space(ctl, entry);
3140 }
3141out:
3142 btrfs_discard_update_discardable(block_group);
3143 spin_unlock(&ctl->tree_lock);
3144
3145 if (align_gap_len)
3146 __btrfs_add_free_space(block_group, align_gap, align_gap_len,
3147 align_gap_trim_state);
3148 return ret;
3149}
3150
3151/*
3152 * given a cluster, put all of its extents back into the free space
3153 * cache. If a block group is passed, this function will only free
3154 * a cluster that belongs to the passed block group.
3155 *
3156 * Otherwise, it'll get a reference on the block group pointed to by the
3157 * cluster and remove the cluster from it.
3158 */
3159void btrfs_return_cluster_to_free_space(
3160 struct btrfs_block_group *block_group,
3161 struct btrfs_free_cluster *cluster)
3162{
3163 struct btrfs_free_space_ctl *ctl;
3164
3165 /* first, get a safe pointer to the block group */
3166 spin_lock(&cluster->lock);
3167 if (!block_group) {
3168 block_group = cluster->block_group;
3169 if (!block_group) {
3170 spin_unlock(&cluster->lock);
3171 return;
3172 }
3173 } else if (cluster->block_group != block_group) {
3174 /* someone else has already freed it don't redo their work */
3175 spin_unlock(&cluster->lock);
3176 return;
3177 }
3178 btrfs_get_block_group(block_group);
3179 spin_unlock(&cluster->lock);
3180
3181 ctl = block_group->free_space_ctl;
3182
3183 /* now return any extents the cluster had on it */
3184 spin_lock(&ctl->tree_lock);
3185 __btrfs_return_cluster_to_free_space(block_group, cluster);
3186 spin_unlock(&ctl->tree_lock);
3187
3188 btrfs_discard_queue_work(&block_group->fs_info->discard_ctl, block_group);
3189
3190 /* finally drop our ref */
3191 btrfs_put_block_group(block_group);
3192}
3193
3194static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group *block_group,
3195 struct btrfs_free_cluster *cluster,
3196 struct btrfs_free_space *entry,
3197 u64 bytes, u64 min_start,
3198 u64 *max_extent_size)
3199{
3200 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3201 int err;
3202 u64 search_start = cluster->window_start;
3203 u64 search_bytes = bytes;
3204 u64 ret = 0;
3205
3206 search_start = min_start;
3207 search_bytes = bytes;
3208
3209 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
3210 if (err) {
3211 *max_extent_size = max(get_max_extent_size(entry),
3212 *max_extent_size);
3213 return 0;
3214 }
3215
3216 ret = search_start;
3217 bitmap_clear_bits(ctl, entry, ret, bytes, false);
3218
3219 return ret;
3220}
3221
3222/*
3223 * given a cluster, try to allocate 'bytes' from it, returns 0
3224 * if it couldn't find anything suitably large, or a logical disk offset
3225 * if things worked out
3226 */
3227u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
3228 struct btrfs_free_cluster *cluster, u64 bytes,
3229 u64 min_start, u64 *max_extent_size)
3230{
3231 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3232 struct btrfs_discard_ctl *discard_ctl =
3233 &block_group->fs_info->discard_ctl;
3234 struct btrfs_free_space *entry = NULL;
3235 struct rb_node *node;
3236 u64 ret = 0;
3237
3238 ASSERT(!btrfs_is_zoned(block_group->fs_info));
3239
3240 spin_lock(&cluster->lock);
3241 if (bytes > cluster->max_size)
3242 goto out;
3243
3244 if (cluster->block_group != block_group)
3245 goto out;
3246
3247 node = rb_first(&cluster->root);
3248 if (!node)
3249 goto out;
3250
3251 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3252 while (1) {
3253 if (entry->bytes < bytes)
3254 *max_extent_size = max(get_max_extent_size(entry),
3255 *max_extent_size);
3256
3257 if (entry->bytes < bytes ||
3258 (!entry->bitmap && entry->offset < min_start)) {
3259 node = rb_next(&entry->offset_index);
3260 if (!node)
3261 break;
3262 entry = rb_entry(node, struct btrfs_free_space,
3263 offset_index);
3264 continue;
3265 }
3266
3267 if (entry->bitmap) {
3268 ret = btrfs_alloc_from_bitmap(block_group,
3269 cluster, entry, bytes,
3270 cluster->window_start,
3271 max_extent_size);
3272 if (ret == 0) {
3273 node = rb_next(&entry->offset_index);
3274 if (!node)
3275 break;
3276 entry = rb_entry(node, struct btrfs_free_space,
3277 offset_index);
3278 continue;
3279 }
3280 cluster->window_start += bytes;
3281 } else {
3282 ret = entry->offset;
3283
3284 entry->offset += bytes;
3285 entry->bytes -= bytes;
3286 }
3287
3288 break;
3289 }
3290out:
3291 spin_unlock(&cluster->lock);
3292
3293 if (!ret)
3294 return 0;
3295
3296 spin_lock(&ctl->tree_lock);
3297
3298 if (!btrfs_free_space_trimmed(entry))
3299 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3300
3301 ctl->free_space -= bytes;
3302 if (!entry->bitmap && !btrfs_free_space_trimmed(entry))
3303 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
3304
3305 spin_lock(&cluster->lock);
3306 if (entry->bytes == 0) {
3307 rb_erase(&entry->offset_index, &cluster->root);
3308 ctl->free_extents--;
3309 if (entry->bitmap) {
3310 kmem_cache_free(btrfs_free_space_bitmap_cachep,
3311 entry->bitmap);
3312 ctl->total_bitmaps--;
3313 recalculate_thresholds(ctl);
3314 } else if (!btrfs_free_space_trimmed(entry)) {
3315 ctl->discardable_extents[BTRFS_STAT_CURR]--;
3316 }
3317 kmem_cache_free(btrfs_free_space_cachep, entry);
3318 }
3319
3320 spin_unlock(&cluster->lock);
3321 spin_unlock(&ctl->tree_lock);
3322
3323 return ret;
3324}
3325
3326static int btrfs_bitmap_cluster(struct btrfs_block_group *block_group,
3327 struct btrfs_free_space *entry,
3328 struct btrfs_free_cluster *cluster,
3329 u64 offset, u64 bytes,
3330 u64 cont1_bytes, u64 min_bytes)
3331{
3332 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3333 unsigned long next_zero;
3334 unsigned long i;
3335 unsigned long want_bits;
3336 unsigned long min_bits;
3337 unsigned long found_bits;
3338 unsigned long max_bits = 0;
3339 unsigned long start = 0;
3340 unsigned long total_found = 0;
3341 int ret;
3342
3343 lockdep_assert_held(&ctl->tree_lock);
3344
3345 i = offset_to_bit(entry->offset, ctl->unit,
3346 max_t(u64, offset, entry->offset));
3347 want_bits = bytes_to_bits(bytes, ctl->unit);
3348 min_bits = bytes_to_bits(min_bytes, ctl->unit);
3349
3350 /*
3351 * Don't bother looking for a cluster in this bitmap if it's heavily
3352 * fragmented.
3353 */
3354 if (entry->max_extent_size &&
3355 entry->max_extent_size < cont1_bytes)
3356 return -ENOSPC;
3357again:
3358 found_bits = 0;
3359 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
3360 next_zero = find_next_zero_bit(entry->bitmap,
3361 BITS_PER_BITMAP, i);
3362 if (next_zero - i >= min_bits) {
3363 found_bits = next_zero - i;
3364 if (found_bits > max_bits)
3365 max_bits = found_bits;
3366 break;
3367 }
3368 if (next_zero - i > max_bits)
3369 max_bits = next_zero - i;
3370 i = next_zero;
3371 }
3372
3373 if (!found_bits) {
3374 entry->max_extent_size = (u64)max_bits * ctl->unit;
3375 return -ENOSPC;
3376 }
3377
3378 if (!total_found) {
3379 start = i;
3380 cluster->max_size = 0;
3381 }
3382
3383 total_found += found_bits;
3384
3385 if (cluster->max_size < found_bits * ctl->unit)
3386 cluster->max_size = found_bits * ctl->unit;
3387
3388 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
3389 i = next_zero + 1;
3390 goto again;
3391 }
3392
3393 cluster->window_start = start * ctl->unit + entry->offset;
3394 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3395 rb_erase_cached(&entry->bytes_index, &ctl->free_space_bytes);
3396
3397 /*
3398 * We need to know if we're currently on the normal space index when we
3399 * manipulate the bitmap so that we know we need to remove and re-insert
3400 * it into the space_index tree. Clear the bytes_index node here so the
3401 * bitmap manipulation helpers know not to mess with the space_index
3402 * until this bitmap entry is added back into the normal cache.
3403 */
3404 RB_CLEAR_NODE(&entry->bytes_index);
3405
3406 ret = tree_insert_offset(ctl, cluster, entry);
3407 ASSERT(!ret); /* -EEXIST; Logic error */
3408
3409 trace_btrfs_setup_cluster(block_group, cluster,
3410 total_found * ctl->unit, 1);
3411 return 0;
3412}
3413
3414/*
3415 * This searches the block group for just extents to fill the cluster with.
3416 * Try to find a cluster with at least bytes total bytes, at least one
3417 * extent of cont1_bytes, and other clusters of at least min_bytes.
3418 */
3419static noinline int
3420setup_cluster_no_bitmap(struct btrfs_block_group *block_group,
3421 struct btrfs_free_cluster *cluster,
3422 struct list_head *bitmaps, u64 offset, u64 bytes,
3423 u64 cont1_bytes, u64 min_bytes)
3424{
3425 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3426 struct btrfs_free_space *first = NULL;
3427 struct btrfs_free_space *entry = NULL;
3428 struct btrfs_free_space *last;
3429 struct rb_node *node;
3430 u64 window_free;
3431 u64 max_extent;
3432 u64 total_size = 0;
3433
3434 lockdep_assert_held(&ctl->tree_lock);
3435
3436 entry = tree_search_offset(ctl, offset, 0, 1);
3437 if (!entry)
3438 return -ENOSPC;
3439
3440 /*
3441 * We don't want bitmaps, so just move along until we find a normal
3442 * extent entry.
3443 */
3444 while (entry->bitmap || entry->bytes < min_bytes) {
3445 if (entry->bitmap && list_empty(&entry->list))
3446 list_add_tail(&entry->list, bitmaps);
3447 node = rb_next(&entry->offset_index);
3448 if (!node)
3449 return -ENOSPC;
3450 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3451 }
3452
3453 window_free = entry->bytes;
3454 max_extent = entry->bytes;
3455 first = entry;
3456 last = entry;
3457
3458 for (node = rb_next(&entry->offset_index); node;
3459 node = rb_next(&entry->offset_index)) {
3460 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3461
3462 if (entry->bitmap) {
3463 if (list_empty(&entry->list))
3464 list_add_tail(&entry->list, bitmaps);
3465 continue;
3466 }
3467
3468 if (entry->bytes < min_bytes)
3469 continue;
3470
3471 last = entry;
3472 window_free += entry->bytes;
3473 if (entry->bytes > max_extent)
3474 max_extent = entry->bytes;
3475 }
3476
3477 if (window_free < bytes || max_extent < cont1_bytes)
3478 return -ENOSPC;
3479
3480 cluster->window_start = first->offset;
3481
3482 node = &first->offset_index;
3483
3484 /*
3485 * now we've found our entries, pull them out of the free space
3486 * cache and put them into the cluster rbtree
3487 */
3488 do {
3489 int ret;
3490
3491 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3492 node = rb_next(&entry->offset_index);
3493 if (entry->bitmap || entry->bytes < min_bytes)
3494 continue;
3495
3496 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3497 rb_erase_cached(&entry->bytes_index, &ctl->free_space_bytes);
3498 ret = tree_insert_offset(ctl, cluster, entry);
3499 total_size += entry->bytes;
3500 ASSERT(!ret); /* -EEXIST; Logic error */
3501 } while (node && entry != last);
3502
3503 cluster->max_size = max_extent;
3504 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
3505 return 0;
3506}
3507
3508/*
3509 * This specifically looks for bitmaps that may work in the cluster, we assume
3510 * that we have already failed to find extents that will work.
3511 */
3512static noinline int
3513setup_cluster_bitmap(struct btrfs_block_group *block_group,
3514 struct btrfs_free_cluster *cluster,
3515 struct list_head *bitmaps, u64 offset, u64 bytes,
3516 u64 cont1_bytes, u64 min_bytes)
3517{
3518 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3519 struct btrfs_free_space *entry = NULL;
3520 int ret = -ENOSPC;
3521 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
3522
3523 if (ctl->total_bitmaps == 0)
3524 return -ENOSPC;
3525
3526 /*
3527 * The bitmap that covers offset won't be in the list unless offset
3528 * is just its start offset.
3529 */
3530 if (!list_empty(bitmaps))
3531 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
3532
3533 if (!entry || entry->offset != bitmap_offset) {
3534 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
3535 if (entry && list_empty(&entry->list))
3536 list_add(&entry->list, bitmaps);
3537 }
3538
3539 list_for_each_entry(entry, bitmaps, list) {
3540 if (entry->bytes < bytes)
3541 continue;
3542 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3543 bytes, cont1_bytes, min_bytes);
3544 if (!ret)
3545 return 0;
3546 }
3547
3548 /*
3549 * The bitmaps list has all the bitmaps that record free space
3550 * starting after offset, so no more search is required.
3551 */
3552 return -ENOSPC;
3553}
3554
3555/*
3556 * here we try to find a cluster of blocks in a block group. The goal
3557 * is to find at least bytes+empty_size.
3558 * We might not find them all in one contiguous area.
3559 *
3560 * returns zero and sets up cluster if things worked out, otherwise
3561 * it returns -enospc
3562 */
3563int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
3564 struct btrfs_free_cluster *cluster,
3565 u64 offset, u64 bytes, u64 empty_size)
3566{
3567 struct btrfs_fs_info *fs_info = block_group->fs_info;
3568 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3569 struct btrfs_free_space *entry, *tmp;
3570 LIST_HEAD(bitmaps);
3571 u64 min_bytes;
3572 u64 cont1_bytes;
3573 int ret;
3574
3575 /*
3576 * Choose the minimum extent size we'll require for this
3577 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3578 * For metadata, allow allocates with smaller extents. For
3579 * data, keep it dense.
3580 */
3581 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3582 cont1_bytes = bytes + empty_size;
3583 min_bytes = cont1_bytes;
3584 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3585 cont1_bytes = bytes;
3586 min_bytes = fs_info->sectorsize;
3587 } else {
3588 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3589 min_bytes = fs_info->sectorsize;
3590 }
3591
3592 spin_lock(&ctl->tree_lock);
3593
3594 /*
3595 * If we know we don't have enough space to make a cluster don't even
3596 * bother doing all the work to try and find one.
3597 */
3598 if (ctl->free_space < bytes) {
3599 spin_unlock(&ctl->tree_lock);
3600 return -ENOSPC;
3601 }
3602
3603 spin_lock(&cluster->lock);
3604
3605 /* someone already found a cluster, hooray */
3606 if (cluster->block_group) {
3607 ret = 0;
3608 goto out;
3609 }
3610
3611 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3612 min_bytes);
3613
3614 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3615 bytes + empty_size,
3616 cont1_bytes, min_bytes);
3617 if (ret)
3618 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3619 offset, bytes + empty_size,
3620 cont1_bytes, min_bytes);
3621
3622 /* Clear our temporary list */
3623 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3624 list_del_init(&entry->list);
3625
3626 if (!ret) {
3627 btrfs_get_block_group(block_group);
3628 list_add_tail(&cluster->block_group_list,
3629 &block_group->cluster_list);
3630 cluster->block_group = block_group;
3631 } else {
3632 trace_btrfs_failed_cluster_setup(block_group);
3633 }
3634out:
3635 spin_unlock(&cluster->lock);
3636 spin_unlock(&ctl->tree_lock);
3637
3638 return ret;
3639}
3640
3641/*
3642 * simple code to zero out a cluster
3643 */
3644void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3645{
3646 spin_lock_init(&cluster->lock);
3647 spin_lock_init(&cluster->refill_lock);
3648 cluster->root = RB_ROOT;
3649 cluster->max_size = 0;
3650 cluster->fragmented = false;
3651 INIT_LIST_HEAD(&cluster->block_group_list);
3652 cluster->block_group = NULL;
3653}
3654
3655static int do_trimming(struct btrfs_block_group *block_group,
3656 u64 *total_trimmed, u64 start, u64 bytes,
3657 u64 reserved_start, u64 reserved_bytes,
3658 enum btrfs_trim_state reserved_trim_state,
3659 struct btrfs_trim_range *trim_entry)
3660{
3661 struct btrfs_space_info *space_info = block_group->space_info;
3662 struct btrfs_fs_info *fs_info = block_group->fs_info;
3663 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3664 int ret;
3665 int update = 0;
3666 const u64 end = start + bytes;
3667 const u64 reserved_end = reserved_start + reserved_bytes;
3668 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3669 u64 trimmed = 0;
3670
3671 spin_lock(&space_info->lock);
3672 spin_lock(&block_group->lock);
3673 if (!block_group->ro) {
3674 block_group->reserved += reserved_bytes;
3675 space_info->bytes_reserved += reserved_bytes;
3676 update = 1;
3677 }
3678 spin_unlock(&block_group->lock);
3679 spin_unlock(&space_info->lock);
3680
3681 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3682 if (!ret) {
3683 *total_trimmed += trimmed;
3684 trim_state = BTRFS_TRIM_STATE_TRIMMED;
3685 }
3686
3687 mutex_lock(&ctl->cache_writeout_mutex);
3688 if (reserved_start < start)
3689 __btrfs_add_free_space(block_group, reserved_start,
3690 start - reserved_start,
3691 reserved_trim_state);
3692 if (end < reserved_end)
3693 __btrfs_add_free_space(block_group, end, reserved_end - end,
3694 reserved_trim_state);
3695 __btrfs_add_free_space(block_group, start, bytes, trim_state);
3696 list_del(&trim_entry->list);
3697 mutex_unlock(&ctl->cache_writeout_mutex);
3698
3699 if (update) {
3700 spin_lock(&space_info->lock);
3701 spin_lock(&block_group->lock);
3702 if (block_group->ro)
3703 space_info->bytes_readonly += reserved_bytes;
3704 block_group->reserved -= reserved_bytes;
3705 space_info->bytes_reserved -= reserved_bytes;
3706 spin_unlock(&block_group->lock);
3707 spin_unlock(&space_info->lock);
3708 }
3709
3710 return ret;
3711}
3712
3713/*
3714 * If @async is set, then we will trim 1 region and return.
3715 */
3716static int trim_no_bitmap(struct btrfs_block_group *block_group,
3717 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3718 bool async)
3719{
3720 struct btrfs_discard_ctl *discard_ctl =
3721 &block_group->fs_info->discard_ctl;
3722 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3723 struct btrfs_free_space *entry;
3724 struct rb_node *node;
3725 int ret = 0;
3726 u64 extent_start;
3727 u64 extent_bytes;
3728 enum btrfs_trim_state extent_trim_state;
3729 u64 bytes;
3730 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3731
3732 while (start < end) {
3733 struct btrfs_trim_range trim_entry;
3734
3735 mutex_lock(&ctl->cache_writeout_mutex);
3736 spin_lock(&ctl->tree_lock);
3737
3738 if (ctl->free_space < minlen)
3739 goto out_unlock;
3740
3741 entry = tree_search_offset(ctl, start, 0, 1);
3742 if (!entry)
3743 goto out_unlock;
3744
3745 /* Skip bitmaps and if async, already trimmed entries */
3746 while (entry->bitmap ||
3747 (async && btrfs_free_space_trimmed(entry))) {
3748 node = rb_next(&entry->offset_index);
3749 if (!node)
3750 goto out_unlock;
3751 entry = rb_entry(node, struct btrfs_free_space,
3752 offset_index);
3753 }
3754
3755 if (entry->offset >= end)
3756 goto out_unlock;
3757
3758 extent_start = entry->offset;
3759 extent_bytes = entry->bytes;
3760 extent_trim_state = entry->trim_state;
3761 if (async) {
3762 start = entry->offset;
3763 bytes = entry->bytes;
3764 if (bytes < minlen) {
3765 spin_unlock(&ctl->tree_lock);
3766 mutex_unlock(&ctl->cache_writeout_mutex);
3767 goto next;
3768 }
3769 unlink_free_space(ctl, entry, true);
3770 /*
3771 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3772 * If X < BTRFS_ASYNC_DISCARD_MIN_FILTER, we won't trim
3773 * X when we come back around. So trim it now.
3774 */
3775 if (max_discard_size &&
3776 bytes >= (max_discard_size +
3777 BTRFS_ASYNC_DISCARD_MIN_FILTER)) {
3778 bytes = max_discard_size;
3779 extent_bytes = max_discard_size;
3780 entry->offset += max_discard_size;
3781 entry->bytes -= max_discard_size;
3782 link_free_space(ctl, entry);
3783 } else {
3784 kmem_cache_free(btrfs_free_space_cachep, entry);
3785 }
3786 } else {
3787 start = max(start, extent_start);
3788 bytes = min(extent_start + extent_bytes, end) - start;
3789 if (bytes < minlen) {
3790 spin_unlock(&ctl->tree_lock);
3791 mutex_unlock(&ctl->cache_writeout_mutex);
3792 goto next;
3793 }
3794
3795 unlink_free_space(ctl, entry, true);
3796 kmem_cache_free(btrfs_free_space_cachep, entry);
3797 }
3798
3799 spin_unlock(&ctl->tree_lock);
3800 trim_entry.start = extent_start;
3801 trim_entry.bytes = extent_bytes;
3802 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3803 mutex_unlock(&ctl->cache_writeout_mutex);
3804
3805 ret = do_trimming(block_group, total_trimmed, start, bytes,
3806 extent_start, extent_bytes, extent_trim_state,
3807 &trim_entry);
3808 if (ret) {
3809 block_group->discard_cursor = start + bytes;
3810 break;
3811 }
3812next:
3813 start += bytes;
3814 block_group->discard_cursor = start;
3815 if (async && *total_trimmed)
3816 break;
3817
3818 if (btrfs_trim_interrupted()) {
3819 ret = -ERESTARTSYS;
3820 break;
3821 }
3822
3823 cond_resched();
3824 }
3825
3826 return ret;
3827
3828out_unlock:
3829 block_group->discard_cursor = btrfs_block_group_end(block_group);
3830 spin_unlock(&ctl->tree_lock);
3831 mutex_unlock(&ctl->cache_writeout_mutex);
3832
3833 return ret;
3834}
3835
3836/*
3837 * If we break out of trimming a bitmap prematurely, we should reset the
3838 * trimming bit. In a rather contrieved case, it's possible to race here so
3839 * reset the state to BTRFS_TRIM_STATE_UNTRIMMED.
3840 *
3841 * start = start of bitmap
3842 * end = near end of bitmap
3843 *
3844 * Thread 1: Thread 2:
3845 * trim_bitmaps(start)
3846 * trim_bitmaps(end)
3847 * end_trimming_bitmap()
3848 * reset_trimming_bitmap()
3849 */
3850static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset)
3851{
3852 struct btrfs_free_space *entry;
3853
3854 spin_lock(&ctl->tree_lock);
3855 entry = tree_search_offset(ctl, offset, 1, 0);
3856 if (entry) {
3857 if (btrfs_free_space_trimmed(entry)) {
3858 ctl->discardable_extents[BTRFS_STAT_CURR] +=
3859 entry->bitmap_extents;
3860 ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes;
3861 }
3862 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3863 }
3864
3865 spin_unlock(&ctl->tree_lock);
3866}
3867
3868static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl,
3869 struct btrfs_free_space *entry)
3870{
3871 if (btrfs_free_space_trimming_bitmap(entry)) {
3872 entry->trim_state = BTRFS_TRIM_STATE_TRIMMED;
3873 ctl->discardable_extents[BTRFS_STAT_CURR] -=
3874 entry->bitmap_extents;
3875 ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes;
3876 }
3877}
3878
3879/*
3880 * If @async is set, then we will trim 1 region and return.
3881 */
3882static int trim_bitmaps(struct btrfs_block_group *block_group,
3883 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3884 u64 maxlen, bool async)
3885{
3886 struct btrfs_discard_ctl *discard_ctl =
3887 &block_group->fs_info->discard_ctl;
3888 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3889 struct btrfs_free_space *entry;
3890 int ret = 0;
3891 int ret2;
3892 u64 bytes;
3893 u64 offset = offset_to_bitmap(ctl, start);
3894 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3895
3896 while (offset < end) {
3897 bool next_bitmap = false;
3898 struct btrfs_trim_range trim_entry;
3899
3900 mutex_lock(&ctl->cache_writeout_mutex);
3901 spin_lock(&ctl->tree_lock);
3902
3903 if (ctl->free_space < minlen) {
3904 block_group->discard_cursor =
3905 btrfs_block_group_end(block_group);
3906 spin_unlock(&ctl->tree_lock);
3907 mutex_unlock(&ctl->cache_writeout_mutex);
3908 break;
3909 }
3910
3911 entry = tree_search_offset(ctl, offset, 1, 0);
3912 /*
3913 * Bitmaps are marked trimmed lossily now to prevent constant
3914 * discarding of the same bitmap (the reason why we are bound
3915 * by the filters). So, retrim the block group bitmaps when we
3916 * are preparing to punt to the unused_bgs list. This uses
3917 * @minlen to determine if we are in BTRFS_DISCARD_INDEX_UNUSED
3918 * which is the only discard index which sets minlen to 0.
3919 */
3920 if (!entry || (async && minlen && start == offset &&
3921 btrfs_free_space_trimmed(entry))) {
3922 spin_unlock(&ctl->tree_lock);
3923 mutex_unlock(&ctl->cache_writeout_mutex);
3924 next_bitmap = true;
3925 goto next;
3926 }
3927
3928 /*
3929 * Async discard bitmap trimming begins at by setting the start
3930 * to be key.objectid and the offset_to_bitmap() aligns to the
3931 * start of the bitmap. This lets us know we are fully
3932 * scanning the bitmap rather than only some portion of it.
3933 */
3934 if (start == offset)
3935 entry->trim_state = BTRFS_TRIM_STATE_TRIMMING;
3936
3937 bytes = minlen;
3938 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3939 if (ret2 || start >= end) {
3940 /*
3941 * We lossily consider a bitmap trimmed if we only skip
3942 * over regions <= BTRFS_ASYNC_DISCARD_MIN_FILTER.
3943 */
3944 if (ret2 && minlen <= BTRFS_ASYNC_DISCARD_MIN_FILTER)
3945 end_trimming_bitmap(ctl, entry);
3946 else
3947 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3948 spin_unlock(&ctl->tree_lock);
3949 mutex_unlock(&ctl->cache_writeout_mutex);
3950 next_bitmap = true;
3951 goto next;
3952 }
3953
3954 /*
3955 * We already trimmed a region, but are using the locking above
3956 * to reset the trim_state.
3957 */
3958 if (async && *total_trimmed) {
3959 spin_unlock(&ctl->tree_lock);
3960 mutex_unlock(&ctl->cache_writeout_mutex);
3961 goto out;
3962 }
3963
3964 bytes = min(bytes, end - start);
3965 if (bytes < minlen || (async && maxlen && bytes > maxlen)) {
3966 spin_unlock(&ctl->tree_lock);
3967 mutex_unlock(&ctl->cache_writeout_mutex);
3968 goto next;
3969 }
3970
3971 /*
3972 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3973 * If X < @minlen, we won't trim X when we come back around.
3974 * So trim it now. We differ here from trimming extents as we
3975 * don't keep individual state per bit.
3976 */
3977 if (async &&
3978 max_discard_size &&
3979 bytes > (max_discard_size + minlen))
3980 bytes = max_discard_size;
3981
3982 bitmap_clear_bits(ctl, entry, start, bytes, true);
3983 if (entry->bytes == 0)
3984 free_bitmap(ctl, entry);
3985
3986 spin_unlock(&ctl->tree_lock);
3987 trim_entry.start = start;
3988 trim_entry.bytes = bytes;
3989 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3990 mutex_unlock(&ctl->cache_writeout_mutex);
3991
3992 ret = do_trimming(block_group, total_trimmed, start, bytes,
3993 start, bytes, 0, &trim_entry);
3994 if (ret) {
3995 reset_trimming_bitmap(ctl, offset);
3996 block_group->discard_cursor =
3997 btrfs_block_group_end(block_group);
3998 break;
3999 }
4000next:
4001 if (next_bitmap) {
4002 offset += BITS_PER_BITMAP * ctl->unit;
4003 start = offset;
4004 } else {
4005 start += bytes;
4006 }
4007 block_group->discard_cursor = start;
4008
4009 if (btrfs_trim_interrupted()) {
4010 if (start != offset)
4011 reset_trimming_bitmap(ctl, offset);
4012 ret = -ERESTARTSYS;
4013 break;
4014 }
4015
4016 cond_resched();
4017 }
4018
4019 if (offset >= end)
4020 block_group->discard_cursor = end;
4021
4022out:
4023 return ret;
4024}
4025
4026int btrfs_trim_block_group(struct btrfs_block_group *block_group,
4027 u64 *trimmed, u64 start, u64 end, u64 minlen)
4028{
4029 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
4030 int ret;
4031 u64 rem = 0;
4032
4033 ASSERT(!btrfs_is_zoned(block_group->fs_info));
4034
4035 *trimmed = 0;
4036
4037 spin_lock(&block_group->lock);
4038 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags)) {
4039 spin_unlock(&block_group->lock);
4040 return 0;
4041 }
4042 btrfs_freeze_block_group(block_group);
4043 spin_unlock(&block_group->lock);
4044
4045 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, false);
4046 if (ret)
4047 goto out;
4048
4049 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, 0, false);
4050 div64_u64_rem(end, BITS_PER_BITMAP * ctl->unit, &rem);
4051 /* If we ended in the middle of a bitmap, reset the trimming flag */
4052 if (rem)
4053 reset_trimming_bitmap(ctl, offset_to_bitmap(ctl, end));
4054out:
4055 btrfs_unfreeze_block_group(block_group);
4056 return ret;
4057}
4058
4059int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
4060 u64 *trimmed, u64 start, u64 end, u64 minlen,
4061 bool async)
4062{
4063 int ret;
4064
4065 *trimmed = 0;
4066
4067 spin_lock(&block_group->lock);
4068 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags)) {
4069 spin_unlock(&block_group->lock);
4070 return 0;
4071 }
4072 btrfs_freeze_block_group(block_group);
4073 spin_unlock(&block_group->lock);
4074
4075 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, async);
4076 btrfs_unfreeze_block_group(block_group);
4077
4078 return ret;
4079}
4080
4081int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
4082 u64 *trimmed, u64 start, u64 end, u64 minlen,
4083 u64 maxlen, bool async)
4084{
4085 int ret;
4086
4087 *trimmed = 0;
4088
4089 spin_lock(&block_group->lock);
4090 if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags)) {
4091 spin_unlock(&block_group->lock);
4092 return 0;
4093 }
4094 btrfs_freeze_block_group(block_group);
4095 spin_unlock(&block_group->lock);
4096
4097 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, maxlen,
4098 async);
4099
4100 btrfs_unfreeze_block_group(block_group);
4101
4102 return ret;
4103}
4104
4105bool btrfs_free_space_cache_v1_active(struct btrfs_fs_info *fs_info)
4106{
4107 return btrfs_super_cache_generation(fs_info->super_copy);
4108}
4109
4110static int cleanup_free_space_cache_v1(struct btrfs_fs_info *fs_info,
4111 struct btrfs_trans_handle *trans)
4112{
4113 struct btrfs_block_group *block_group;
4114 struct rb_node *node;
4115 int ret = 0;
4116
4117 btrfs_info(fs_info, "cleaning free space cache v1");
4118
4119 node = rb_first_cached(&fs_info->block_group_cache_tree);
4120 while (node) {
4121 block_group = rb_entry(node, struct btrfs_block_group, cache_node);
4122 ret = btrfs_remove_free_space_inode(trans, NULL, block_group);
4123 if (ret)
4124 goto out;
4125 node = rb_next(node);
4126 }
4127out:
4128 return ret;
4129}
4130
4131int btrfs_set_free_space_cache_v1_active(struct btrfs_fs_info *fs_info, bool active)
4132{
4133 struct btrfs_trans_handle *trans;
4134 int ret;
4135
4136 /*
4137 * update_super_roots will appropriately set or unset
4138 * super_copy->cache_generation based on SPACE_CACHE and
4139 * BTRFS_FS_CLEANUP_SPACE_CACHE_V1. For this reason, we need a
4140 * transaction commit whether we are enabling space cache v1 and don't
4141 * have any other work to do, or are disabling it and removing free
4142 * space inodes.
4143 */
4144 trans = btrfs_start_transaction(fs_info->tree_root, 0);
4145 if (IS_ERR(trans))
4146 return PTR_ERR(trans);
4147
4148 if (!active) {
4149 set_bit(BTRFS_FS_CLEANUP_SPACE_CACHE_V1, &fs_info->flags);
4150 ret = cleanup_free_space_cache_v1(fs_info, trans);
4151 if (ret) {
4152 btrfs_abort_transaction(trans, ret);
4153 btrfs_end_transaction(trans);
4154 goto out;
4155 }
4156 }
4157
4158 ret = btrfs_commit_transaction(trans);
4159out:
4160 clear_bit(BTRFS_FS_CLEANUP_SPACE_CACHE_V1, &fs_info->flags);
4161
4162 return ret;
4163}
4164
4165int __init btrfs_free_space_init(void)
4166{
4167 btrfs_free_space_cachep = KMEM_CACHE(btrfs_free_space, 0);
4168 if (!btrfs_free_space_cachep)
4169 return -ENOMEM;
4170
4171 btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap",
4172 PAGE_SIZE, PAGE_SIZE,
4173 0, NULL);
4174 if (!btrfs_free_space_bitmap_cachep) {
4175 kmem_cache_destroy(btrfs_free_space_cachep);
4176 return -ENOMEM;
4177 }
4178
4179 return 0;
4180}
4181
4182void __cold btrfs_free_space_exit(void)
4183{
4184 kmem_cache_destroy(btrfs_free_space_cachep);
4185 kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
4186}
4187
4188#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4189/*
4190 * Use this if you need to make a bitmap or extent entry specifically, it
4191 * doesn't do any of the merging that add_free_space does, this acts a lot like
4192 * how the free space cache loading stuff works, so you can get really weird
4193 * configurations.
4194 */
4195int test_add_free_space_entry(struct btrfs_block_group *cache,
4196 u64 offset, u64 bytes, bool bitmap)
4197{
4198 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4199 struct btrfs_free_space *info = NULL, *bitmap_info;
4200 void *map = NULL;
4201 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_TRIMMED;
4202 u64 bytes_added;
4203 int ret;
4204
4205again:
4206 if (!info) {
4207 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
4208 if (!info)
4209 return -ENOMEM;
4210 }
4211
4212 if (!bitmap) {
4213 spin_lock(&ctl->tree_lock);
4214 info->offset = offset;
4215 info->bytes = bytes;
4216 info->max_extent_size = 0;
4217 ret = link_free_space(ctl, info);
4218 spin_unlock(&ctl->tree_lock);
4219 if (ret)
4220 kmem_cache_free(btrfs_free_space_cachep, info);
4221 return ret;
4222 }
4223
4224 if (!map) {
4225 map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
4226 if (!map) {
4227 kmem_cache_free(btrfs_free_space_cachep, info);
4228 return -ENOMEM;
4229 }
4230 }
4231
4232 spin_lock(&ctl->tree_lock);
4233 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4234 1, 0);
4235 if (!bitmap_info) {
4236 info->bitmap = map;
4237 map = NULL;
4238 add_new_bitmap(ctl, info, offset);
4239 bitmap_info = info;
4240 info = NULL;
4241 }
4242
4243 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
4244 trim_state);
4245
4246 bytes -= bytes_added;
4247 offset += bytes_added;
4248 spin_unlock(&ctl->tree_lock);
4249
4250 if (bytes)
4251 goto again;
4252
4253 if (info)
4254 kmem_cache_free(btrfs_free_space_cachep, info);
4255 if (map)
4256 kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
4257 return 0;
4258}
4259
4260/*
4261 * Checks to see if the given range is in the free space cache. This is really
4262 * just used to check the absence of space, so if there is free space in the
4263 * range at all we will return 1.
4264 */
4265int test_check_exists(struct btrfs_block_group *cache,
4266 u64 offset, u64 bytes)
4267{
4268 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4269 struct btrfs_free_space *info;
4270 int ret = 0;
4271
4272 spin_lock(&ctl->tree_lock);
4273 info = tree_search_offset(ctl, offset, 0, 0);
4274 if (!info) {
4275 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4276 1, 0);
4277 if (!info)
4278 goto out;
4279 }
4280
4281have_info:
4282 if (info->bitmap) {
4283 u64 bit_off, bit_bytes;
4284 struct rb_node *n;
4285 struct btrfs_free_space *tmp;
4286
4287 bit_off = offset;
4288 bit_bytes = ctl->unit;
4289 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
4290 if (!ret) {
4291 if (bit_off == offset) {
4292 ret = 1;
4293 goto out;
4294 } else if (bit_off > offset &&
4295 offset + bytes > bit_off) {
4296 ret = 1;
4297 goto out;
4298 }
4299 }
4300
4301 n = rb_prev(&info->offset_index);
4302 while (n) {
4303 tmp = rb_entry(n, struct btrfs_free_space,
4304 offset_index);
4305 if (tmp->offset + tmp->bytes < offset)
4306 break;
4307 if (offset + bytes < tmp->offset) {
4308 n = rb_prev(&tmp->offset_index);
4309 continue;
4310 }
4311 info = tmp;
4312 goto have_info;
4313 }
4314
4315 n = rb_next(&info->offset_index);
4316 while (n) {
4317 tmp = rb_entry(n, struct btrfs_free_space,
4318 offset_index);
4319 if (offset + bytes < tmp->offset)
4320 break;
4321 if (tmp->offset + tmp->bytes < offset) {
4322 n = rb_next(&tmp->offset_index);
4323 continue;
4324 }
4325 info = tmp;
4326 goto have_info;
4327 }
4328
4329 ret = 0;
4330 goto out;
4331 }
4332
4333 if (info->offset == offset) {
4334 ret = 1;
4335 goto out;
4336 }
4337
4338 if (offset > info->offset && offset < info->offset + info->bytes)
4339 ret = 1;
4340out:
4341 spin_unlock(&ctl->tree_lock);
4342 return ret;
4343}
4344#endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
1/*
2 * Copyright (C) 2008 Red Hat. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/pagemap.h>
20#include <linux/sched.h>
21#include <linux/slab.h>
22#include <linux/math64.h>
23#include <linux/ratelimit.h>
24#include "ctree.h"
25#include "free-space-cache.h"
26#include "transaction.h"
27#include "disk-io.h"
28#include "extent_io.h"
29#include "inode-map.h"
30
31#define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
32#define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
33
34static int link_free_space(struct btrfs_free_space_ctl *ctl,
35 struct btrfs_free_space *info);
36static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
37 struct btrfs_free_space *info);
38
39static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
40 struct btrfs_path *path,
41 u64 offset)
42{
43 struct btrfs_key key;
44 struct btrfs_key location;
45 struct btrfs_disk_key disk_key;
46 struct btrfs_free_space_header *header;
47 struct extent_buffer *leaf;
48 struct inode *inode = NULL;
49 int ret;
50
51 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
52 key.offset = offset;
53 key.type = 0;
54
55 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
56 if (ret < 0)
57 return ERR_PTR(ret);
58 if (ret > 0) {
59 btrfs_release_path(path);
60 return ERR_PTR(-ENOENT);
61 }
62
63 leaf = path->nodes[0];
64 header = btrfs_item_ptr(leaf, path->slots[0],
65 struct btrfs_free_space_header);
66 btrfs_free_space_key(leaf, header, &disk_key);
67 btrfs_disk_key_to_cpu(&location, &disk_key);
68 btrfs_release_path(path);
69
70 inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
71 if (!inode)
72 return ERR_PTR(-ENOENT);
73 if (IS_ERR(inode))
74 return inode;
75 if (is_bad_inode(inode)) {
76 iput(inode);
77 return ERR_PTR(-ENOENT);
78 }
79
80 mapping_set_gfp_mask(inode->i_mapping,
81 mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
82
83 return inode;
84}
85
86struct inode *lookup_free_space_inode(struct btrfs_root *root,
87 struct btrfs_block_group_cache
88 *block_group, struct btrfs_path *path)
89{
90 struct inode *inode = NULL;
91 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
92
93 spin_lock(&block_group->lock);
94 if (block_group->inode)
95 inode = igrab(block_group->inode);
96 spin_unlock(&block_group->lock);
97 if (inode)
98 return inode;
99
100 inode = __lookup_free_space_inode(root, path,
101 block_group->key.objectid);
102 if (IS_ERR(inode))
103 return inode;
104
105 spin_lock(&block_group->lock);
106 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
107 btrfs_info(root->fs_info,
108 "Old style space inode found, converting.");
109 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
110 BTRFS_INODE_NODATACOW;
111 block_group->disk_cache_state = BTRFS_DC_CLEAR;
112 }
113
114 if (!block_group->iref) {
115 block_group->inode = igrab(inode);
116 block_group->iref = 1;
117 }
118 spin_unlock(&block_group->lock);
119
120 return inode;
121}
122
123static int __create_free_space_inode(struct btrfs_root *root,
124 struct btrfs_trans_handle *trans,
125 struct btrfs_path *path,
126 u64 ino, u64 offset)
127{
128 struct btrfs_key key;
129 struct btrfs_disk_key disk_key;
130 struct btrfs_free_space_header *header;
131 struct btrfs_inode_item *inode_item;
132 struct extent_buffer *leaf;
133 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
134 int ret;
135
136 ret = btrfs_insert_empty_inode(trans, root, path, ino);
137 if (ret)
138 return ret;
139
140 /* We inline crc's for the free disk space cache */
141 if (ino != BTRFS_FREE_INO_OBJECTID)
142 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
143
144 leaf = path->nodes[0];
145 inode_item = btrfs_item_ptr(leaf, path->slots[0],
146 struct btrfs_inode_item);
147 btrfs_item_key(leaf, &disk_key, path->slots[0]);
148 memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
149 sizeof(*inode_item));
150 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
151 btrfs_set_inode_size(leaf, inode_item, 0);
152 btrfs_set_inode_nbytes(leaf, inode_item, 0);
153 btrfs_set_inode_uid(leaf, inode_item, 0);
154 btrfs_set_inode_gid(leaf, inode_item, 0);
155 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
156 btrfs_set_inode_flags(leaf, inode_item, flags);
157 btrfs_set_inode_nlink(leaf, inode_item, 1);
158 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
159 btrfs_set_inode_block_group(leaf, inode_item, offset);
160 btrfs_mark_buffer_dirty(leaf);
161 btrfs_release_path(path);
162
163 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
164 key.offset = offset;
165 key.type = 0;
166
167 ret = btrfs_insert_empty_item(trans, root, path, &key,
168 sizeof(struct btrfs_free_space_header));
169 if (ret < 0) {
170 btrfs_release_path(path);
171 return ret;
172 }
173 leaf = path->nodes[0];
174 header = btrfs_item_ptr(leaf, path->slots[0],
175 struct btrfs_free_space_header);
176 memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
177 btrfs_set_free_space_key(leaf, header, &disk_key);
178 btrfs_mark_buffer_dirty(leaf);
179 btrfs_release_path(path);
180
181 return 0;
182}
183
184int create_free_space_inode(struct btrfs_root *root,
185 struct btrfs_trans_handle *trans,
186 struct btrfs_block_group_cache *block_group,
187 struct btrfs_path *path)
188{
189 int ret;
190 u64 ino;
191
192 ret = btrfs_find_free_objectid(root, &ino);
193 if (ret < 0)
194 return ret;
195
196 return __create_free_space_inode(root, trans, path, ino,
197 block_group->key.objectid);
198}
199
200int btrfs_check_trunc_cache_free_space(struct btrfs_root *root,
201 struct btrfs_block_rsv *rsv)
202{
203 u64 needed_bytes;
204 int ret;
205
206 /* 1 for slack space, 1 for updating the inode */
207 needed_bytes = btrfs_calc_trunc_metadata_size(root, 1) +
208 btrfs_calc_trans_metadata_size(root, 1);
209
210 spin_lock(&rsv->lock);
211 if (rsv->reserved < needed_bytes)
212 ret = -ENOSPC;
213 else
214 ret = 0;
215 spin_unlock(&rsv->lock);
216 return ret;
217}
218
219int btrfs_truncate_free_space_cache(struct btrfs_root *root,
220 struct btrfs_trans_handle *trans,
221 struct inode *inode)
222{
223 int ret = 0;
224
225 btrfs_i_size_write(inode, 0);
226 truncate_pagecache(inode, 0);
227
228 /*
229 * We don't need an orphan item because truncating the free space cache
230 * will never be split across transactions.
231 */
232 ret = btrfs_truncate_inode_items(trans, root, inode,
233 0, BTRFS_EXTENT_DATA_KEY);
234 if (ret) {
235 btrfs_abort_transaction(trans, root, ret);
236 return ret;
237 }
238
239 ret = btrfs_update_inode(trans, root, inode);
240 if (ret)
241 btrfs_abort_transaction(trans, root, ret);
242
243 return ret;
244}
245
246static int readahead_cache(struct inode *inode)
247{
248 struct file_ra_state *ra;
249 unsigned long last_index;
250
251 ra = kzalloc(sizeof(*ra), GFP_NOFS);
252 if (!ra)
253 return -ENOMEM;
254
255 file_ra_state_init(ra, inode->i_mapping);
256 last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
257
258 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
259
260 kfree(ra);
261
262 return 0;
263}
264
265struct io_ctl {
266 void *cur, *orig;
267 struct page *page;
268 struct page **pages;
269 struct btrfs_root *root;
270 unsigned long size;
271 int index;
272 int num_pages;
273 unsigned check_crcs:1;
274};
275
276static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode,
277 struct btrfs_root *root)
278{
279 memset(io_ctl, 0, sizeof(struct io_ctl));
280 io_ctl->num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
281 PAGE_CACHE_SHIFT;
282 io_ctl->pages = kzalloc(sizeof(struct page *) * io_ctl->num_pages,
283 GFP_NOFS);
284 if (!io_ctl->pages)
285 return -ENOMEM;
286 io_ctl->root = root;
287 if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
288 io_ctl->check_crcs = 1;
289 return 0;
290}
291
292static void io_ctl_free(struct io_ctl *io_ctl)
293{
294 kfree(io_ctl->pages);
295}
296
297static void io_ctl_unmap_page(struct io_ctl *io_ctl)
298{
299 if (io_ctl->cur) {
300 kunmap(io_ctl->page);
301 io_ctl->cur = NULL;
302 io_ctl->orig = NULL;
303 }
304}
305
306static void io_ctl_map_page(struct io_ctl *io_ctl, int clear)
307{
308 ASSERT(io_ctl->index < io_ctl->num_pages);
309 io_ctl->page = io_ctl->pages[io_ctl->index++];
310 io_ctl->cur = kmap(io_ctl->page);
311 io_ctl->orig = io_ctl->cur;
312 io_ctl->size = PAGE_CACHE_SIZE;
313 if (clear)
314 memset(io_ctl->cur, 0, PAGE_CACHE_SIZE);
315}
316
317static void io_ctl_drop_pages(struct io_ctl *io_ctl)
318{
319 int i;
320
321 io_ctl_unmap_page(io_ctl);
322
323 for (i = 0; i < io_ctl->num_pages; i++) {
324 if (io_ctl->pages[i]) {
325 ClearPageChecked(io_ctl->pages[i]);
326 unlock_page(io_ctl->pages[i]);
327 page_cache_release(io_ctl->pages[i]);
328 }
329 }
330}
331
332static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
333 int uptodate)
334{
335 struct page *page;
336 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
337 int i;
338
339 for (i = 0; i < io_ctl->num_pages; i++) {
340 page = find_or_create_page(inode->i_mapping, i, mask);
341 if (!page) {
342 io_ctl_drop_pages(io_ctl);
343 return -ENOMEM;
344 }
345 io_ctl->pages[i] = page;
346 if (uptodate && !PageUptodate(page)) {
347 btrfs_readpage(NULL, page);
348 lock_page(page);
349 if (!PageUptodate(page)) {
350 btrfs_err(BTRFS_I(inode)->root->fs_info,
351 "error reading free space cache");
352 io_ctl_drop_pages(io_ctl);
353 return -EIO;
354 }
355 }
356 }
357
358 for (i = 0; i < io_ctl->num_pages; i++) {
359 clear_page_dirty_for_io(io_ctl->pages[i]);
360 set_page_extent_mapped(io_ctl->pages[i]);
361 }
362
363 return 0;
364}
365
366static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
367{
368 __le64 *val;
369
370 io_ctl_map_page(io_ctl, 1);
371
372 /*
373 * Skip the csum areas. If we don't check crcs then we just have a
374 * 64bit chunk at the front of the first page.
375 */
376 if (io_ctl->check_crcs) {
377 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
378 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
379 } else {
380 io_ctl->cur += sizeof(u64);
381 io_ctl->size -= sizeof(u64) * 2;
382 }
383
384 val = io_ctl->cur;
385 *val = cpu_to_le64(generation);
386 io_ctl->cur += sizeof(u64);
387}
388
389static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
390{
391 __le64 *gen;
392
393 /*
394 * Skip the crc area. If we don't check crcs then we just have a 64bit
395 * chunk at the front of the first page.
396 */
397 if (io_ctl->check_crcs) {
398 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
399 io_ctl->size -= sizeof(u64) +
400 (sizeof(u32) * io_ctl->num_pages);
401 } else {
402 io_ctl->cur += sizeof(u64);
403 io_ctl->size -= sizeof(u64) * 2;
404 }
405
406 gen = io_ctl->cur;
407 if (le64_to_cpu(*gen) != generation) {
408 printk_ratelimited(KERN_ERR "BTRFS: space cache generation "
409 "(%Lu) does not match inode (%Lu)\n", *gen,
410 generation);
411 io_ctl_unmap_page(io_ctl);
412 return -EIO;
413 }
414 io_ctl->cur += sizeof(u64);
415 return 0;
416}
417
418static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
419{
420 u32 *tmp;
421 u32 crc = ~(u32)0;
422 unsigned offset = 0;
423
424 if (!io_ctl->check_crcs) {
425 io_ctl_unmap_page(io_ctl);
426 return;
427 }
428
429 if (index == 0)
430 offset = sizeof(u32) * io_ctl->num_pages;
431
432 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
433 PAGE_CACHE_SIZE - offset);
434 btrfs_csum_final(crc, (char *)&crc);
435 io_ctl_unmap_page(io_ctl);
436 tmp = kmap(io_ctl->pages[0]);
437 tmp += index;
438 *tmp = crc;
439 kunmap(io_ctl->pages[0]);
440}
441
442static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
443{
444 u32 *tmp, val;
445 u32 crc = ~(u32)0;
446 unsigned offset = 0;
447
448 if (!io_ctl->check_crcs) {
449 io_ctl_map_page(io_ctl, 0);
450 return 0;
451 }
452
453 if (index == 0)
454 offset = sizeof(u32) * io_ctl->num_pages;
455
456 tmp = kmap(io_ctl->pages[0]);
457 tmp += index;
458 val = *tmp;
459 kunmap(io_ctl->pages[0]);
460
461 io_ctl_map_page(io_ctl, 0);
462 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
463 PAGE_CACHE_SIZE - offset);
464 btrfs_csum_final(crc, (char *)&crc);
465 if (val != crc) {
466 printk_ratelimited(KERN_ERR "BTRFS: csum mismatch on free "
467 "space cache\n");
468 io_ctl_unmap_page(io_ctl);
469 return -EIO;
470 }
471
472 return 0;
473}
474
475static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes,
476 void *bitmap)
477{
478 struct btrfs_free_space_entry *entry;
479
480 if (!io_ctl->cur)
481 return -ENOSPC;
482
483 entry = io_ctl->cur;
484 entry->offset = cpu_to_le64(offset);
485 entry->bytes = cpu_to_le64(bytes);
486 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
487 BTRFS_FREE_SPACE_EXTENT;
488 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
489 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
490
491 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
492 return 0;
493
494 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
495
496 /* No more pages to map */
497 if (io_ctl->index >= io_ctl->num_pages)
498 return 0;
499
500 /* map the next page */
501 io_ctl_map_page(io_ctl, 1);
502 return 0;
503}
504
505static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap)
506{
507 if (!io_ctl->cur)
508 return -ENOSPC;
509
510 /*
511 * If we aren't at the start of the current page, unmap this one and
512 * map the next one if there is any left.
513 */
514 if (io_ctl->cur != io_ctl->orig) {
515 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
516 if (io_ctl->index >= io_ctl->num_pages)
517 return -ENOSPC;
518 io_ctl_map_page(io_ctl, 0);
519 }
520
521 memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE);
522 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
523 if (io_ctl->index < io_ctl->num_pages)
524 io_ctl_map_page(io_ctl, 0);
525 return 0;
526}
527
528static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl)
529{
530 /*
531 * If we're not on the boundary we know we've modified the page and we
532 * need to crc the page.
533 */
534 if (io_ctl->cur != io_ctl->orig)
535 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
536 else
537 io_ctl_unmap_page(io_ctl);
538
539 while (io_ctl->index < io_ctl->num_pages) {
540 io_ctl_map_page(io_ctl, 1);
541 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
542 }
543}
544
545static int io_ctl_read_entry(struct io_ctl *io_ctl,
546 struct btrfs_free_space *entry, u8 *type)
547{
548 struct btrfs_free_space_entry *e;
549 int ret;
550
551 if (!io_ctl->cur) {
552 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
553 if (ret)
554 return ret;
555 }
556
557 e = io_ctl->cur;
558 entry->offset = le64_to_cpu(e->offset);
559 entry->bytes = le64_to_cpu(e->bytes);
560 *type = e->type;
561 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
562 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
563
564 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
565 return 0;
566
567 io_ctl_unmap_page(io_ctl);
568
569 return 0;
570}
571
572static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
573 struct btrfs_free_space *entry)
574{
575 int ret;
576
577 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
578 if (ret)
579 return ret;
580
581 memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE);
582 io_ctl_unmap_page(io_ctl);
583
584 return 0;
585}
586
587/*
588 * Since we attach pinned extents after the fact we can have contiguous sections
589 * of free space that are split up in entries. This poses a problem with the
590 * tree logging stuff since it could have allocated across what appears to be 2
591 * entries since we would have merged the entries when adding the pinned extents
592 * back to the free space cache. So run through the space cache that we just
593 * loaded and merge contiguous entries. This will make the log replay stuff not
594 * blow up and it will make for nicer allocator behavior.
595 */
596static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
597{
598 struct btrfs_free_space *e, *prev = NULL;
599 struct rb_node *n;
600
601again:
602 spin_lock(&ctl->tree_lock);
603 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
604 e = rb_entry(n, struct btrfs_free_space, offset_index);
605 if (!prev)
606 goto next;
607 if (e->bitmap || prev->bitmap)
608 goto next;
609 if (prev->offset + prev->bytes == e->offset) {
610 unlink_free_space(ctl, prev);
611 unlink_free_space(ctl, e);
612 prev->bytes += e->bytes;
613 kmem_cache_free(btrfs_free_space_cachep, e);
614 link_free_space(ctl, prev);
615 prev = NULL;
616 spin_unlock(&ctl->tree_lock);
617 goto again;
618 }
619next:
620 prev = e;
621 }
622 spin_unlock(&ctl->tree_lock);
623}
624
625static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
626 struct btrfs_free_space_ctl *ctl,
627 struct btrfs_path *path, u64 offset)
628{
629 struct btrfs_free_space_header *header;
630 struct extent_buffer *leaf;
631 struct io_ctl io_ctl;
632 struct btrfs_key key;
633 struct btrfs_free_space *e, *n;
634 struct list_head bitmaps;
635 u64 num_entries;
636 u64 num_bitmaps;
637 u64 generation;
638 u8 type;
639 int ret = 0;
640
641 INIT_LIST_HEAD(&bitmaps);
642
643 /* Nothing in the space cache, goodbye */
644 if (!i_size_read(inode))
645 return 0;
646
647 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
648 key.offset = offset;
649 key.type = 0;
650
651 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
652 if (ret < 0)
653 return 0;
654 else if (ret > 0) {
655 btrfs_release_path(path);
656 return 0;
657 }
658
659 ret = -1;
660
661 leaf = path->nodes[0];
662 header = btrfs_item_ptr(leaf, path->slots[0],
663 struct btrfs_free_space_header);
664 num_entries = btrfs_free_space_entries(leaf, header);
665 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
666 generation = btrfs_free_space_generation(leaf, header);
667 btrfs_release_path(path);
668
669 if (BTRFS_I(inode)->generation != generation) {
670 btrfs_err(root->fs_info,
671 "free space inode generation (%llu) "
672 "did not match free space cache generation (%llu)",
673 BTRFS_I(inode)->generation, generation);
674 return 0;
675 }
676
677 if (!num_entries)
678 return 0;
679
680 ret = io_ctl_init(&io_ctl, inode, root);
681 if (ret)
682 return ret;
683
684 ret = readahead_cache(inode);
685 if (ret)
686 goto out;
687
688 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
689 if (ret)
690 goto out;
691
692 ret = io_ctl_check_crc(&io_ctl, 0);
693 if (ret)
694 goto free_cache;
695
696 ret = io_ctl_check_generation(&io_ctl, generation);
697 if (ret)
698 goto free_cache;
699
700 while (num_entries) {
701 e = kmem_cache_zalloc(btrfs_free_space_cachep,
702 GFP_NOFS);
703 if (!e)
704 goto free_cache;
705
706 ret = io_ctl_read_entry(&io_ctl, e, &type);
707 if (ret) {
708 kmem_cache_free(btrfs_free_space_cachep, e);
709 goto free_cache;
710 }
711
712 if (!e->bytes) {
713 kmem_cache_free(btrfs_free_space_cachep, e);
714 goto free_cache;
715 }
716
717 if (type == BTRFS_FREE_SPACE_EXTENT) {
718 spin_lock(&ctl->tree_lock);
719 ret = link_free_space(ctl, e);
720 spin_unlock(&ctl->tree_lock);
721 if (ret) {
722 btrfs_err(root->fs_info,
723 "Duplicate entries in free space cache, dumping");
724 kmem_cache_free(btrfs_free_space_cachep, e);
725 goto free_cache;
726 }
727 } else {
728 ASSERT(num_bitmaps);
729 num_bitmaps--;
730 e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
731 if (!e->bitmap) {
732 kmem_cache_free(
733 btrfs_free_space_cachep, e);
734 goto free_cache;
735 }
736 spin_lock(&ctl->tree_lock);
737 ret = link_free_space(ctl, e);
738 ctl->total_bitmaps++;
739 ctl->op->recalc_thresholds(ctl);
740 spin_unlock(&ctl->tree_lock);
741 if (ret) {
742 btrfs_err(root->fs_info,
743 "Duplicate entries in free space cache, dumping");
744 kmem_cache_free(btrfs_free_space_cachep, e);
745 goto free_cache;
746 }
747 list_add_tail(&e->list, &bitmaps);
748 }
749
750 num_entries--;
751 }
752
753 io_ctl_unmap_page(&io_ctl);
754
755 /*
756 * We add the bitmaps at the end of the entries in order that
757 * the bitmap entries are added to the cache.
758 */
759 list_for_each_entry_safe(e, n, &bitmaps, list) {
760 list_del_init(&e->list);
761 ret = io_ctl_read_bitmap(&io_ctl, e);
762 if (ret)
763 goto free_cache;
764 }
765
766 io_ctl_drop_pages(&io_ctl);
767 merge_space_tree(ctl);
768 ret = 1;
769out:
770 io_ctl_free(&io_ctl);
771 return ret;
772free_cache:
773 io_ctl_drop_pages(&io_ctl);
774 __btrfs_remove_free_space_cache(ctl);
775 goto out;
776}
777
778int load_free_space_cache(struct btrfs_fs_info *fs_info,
779 struct btrfs_block_group_cache *block_group)
780{
781 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
782 struct btrfs_root *root = fs_info->tree_root;
783 struct inode *inode;
784 struct btrfs_path *path;
785 int ret = 0;
786 bool matched;
787 u64 used = btrfs_block_group_used(&block_group->item);
788
789 /*
790 * If this block group has been marked to be cleared for one reason or
791 * another then we can't trust the on disk cache, so just return.
792 */
793 spin_lock(&block_group->lock);
794 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
795 spin_unlock(&block_group->lock);
796 return 0;
797 }
798 spin_unlock(&block_group->lock);
799
800 path = btrfs_alloc_path();
801 if (!path)
802 return 0;
803 path->search_commit_root = 1;
804 path->skip_locking = 1;
805
806 inode = lookup_free_space_inode(root, block_group, path);
807 if (IS_ERR(inode)) {
808 btrfs_free_path(path);
809 return 0;
810 }
811
812 /* We may have converted the inode and made the cache invalid. */
813 spin_lock(&block_group->lock);
814 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
815 spin_unlock(&block_group->lock);
816 btrfs_free_path(path);
817 goto out;
818 }
819 spin_unlock(&block_group->lock);
820
821 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
822 path, block_group->key.objectid);
823 btrfs_free_path(path);
824 if (ret <= 0)
825 goto out;
826
827 spin_lock(&ctl->tree_lock);
828 matched = (ctl->free_space == (block_group->key.offset - used -
829 block_group->bytes_super));
830 spin_unlock(&ctl->tree_lock);
831
832 if (!matched) {
833 __btrfs_remove_free_space_cache(ctl);
834 btrfs_err(fs_info, "block group %llu has wrong amount of free space",
835 block_group->key.objectid);
836 ret = -1;
837 }
838out:
839 if (ret < 0) {
840 /* This cache is bogus, make sure it gets cleared */
841 spin_lock(&block_group->lock);
842 block_group->disk_cache_state = BTRFS_DC_CLEAR;
843 spin_unlock(&block_group->lock);
844 ret = 0;
845
846 btrfs_err(fs_info, "failed to load free space cache for block group %llu",
847 block_group->key.objectid);
848 }
849
850 iput(inode);
851 return ret;
852}
853
854/**
855 * __btrfs_write_out_cache - write out cached info to an inode
856 * @root - the root the inode belongs to
857 * @ctl - the free space cache we are going to write out
858 * @block_group - the block_group for this cache if it belongs to a block_group
859 * @trans - the trans handle
860 * @path - the path to use
861 * @offset - the offset for the key we'll insert
862 *
863 * This function writes out a free space cache struct to disk for quick recovery
864 * on mount. This will return 0 if it was successfull in writing the cache out,
865 * and -1 if it was not.
866 */
867static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
868 struct btrfs_free_space_ctl *ctl,
869 struct btrfs_block_group_cache *block_group,
870 struct btrfs_trans_handle *trans,
871 struct btrfs_path *path, u64 offset)
872{
873 struct btrfs_free_space_header *header;
874 struct extent_buffer *leaf;
875 struct rb_node *node;
876 struct list_head *pos, *n;
877 struct extent_state *cached_state = NULL;
878 struct btrfs_free_cluster *cluster = NULL;
879 struct extent_io_tree *unpin = NULL;
880 struct io_ctl io_ctl;
881 struct list_head bitmap_list;
882 struct btrfs_key key;
883 u64 start, extent_start, extent_end, len;
884 int entries = 0;
885 int bitmaps = 0;
886 int ret;
887 int err = -1;
888
889 INIT_LIST_HEAD(&bitmap_list);
890
891 if (!i_size_read(inode))
892 return -1;
893
894 ret = io_ctl_init(&io_ctl, inode, root);
895 if (ret)
896 return -1;
897
898 /* Get the cluster for this block_group if it exists */
899 if (block_group && !list_empty(&block_group->cluster_list))
900 cluster = list_entry(block_group->cluster_list.next,
901 struct btrfs_free_cluster,
902 block_group_list);
903
904 /* Lock all pages first so we can lock the extent safely. */
905 io_ctl_prepare_pages(&io_ctl, inode, 0);
906
907 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
908 0, &cached_state);
909
910 node = rb_first(&ctl->free_space_offset);
911 if (!node && cluster) {
912 node = rb_first(&cluster->root);
913 cluster = NULL;
914 }
915
916 /* Make sure we can fit our crcs into the first page */
917 if (io_ctl.check_crcs &&
918 (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
919 goto out_nospc;
920
921 io_ctl_set_generation(&io_ctl, trans->transid);
922
923 /* Write out the extent entries */
924 while (node) {
925 struct btrfs_free_space *e;
926
927 e = rb_entry(node, struct btrfs_free_space, offset_index);
928 entries++;
929
930 ret = io_ctl_add_entry(&io_ctl, e->offset, e->bytes,
931 e->bitmap);
932 if (ret)
933 goto out_nospc;
934
935 if (e->bitmap) {
936 list_add_tail(&e->list, &bitmap_list);
937 bitmaps++;
938 }
939 node = rb_next(node);
940 if (!node && cluster) {
941 node = rb_first(&cluster->root);
942 cluster = NULL;
943 }
944 }
945
946 /*
947 * We want to add any pinned extents to our free space cache
948 * so we don't leak the space
949 */
950
951 /*
952 * We shouldn't have switched the pinned extents yet so this is the
953 * right one
954 */
955 unpin = root->fs_info->pinned_extents;
956
957 if (block_group)
958 start = block_group->key.objectid;
959
960 while (block_group && (start < block_group->key.objectid +
961 block_group->key.offset)) {
962 ret = find_first_extent_bit(unpin, start,
963 &extent_start, &extent_end,
964 EXTENT_DIRTY, NULL);
965 if (ret) {
966 ret = 0;
967 break;
968 }
969
970 /* This pinned extent is out of our range */
971 if (extent_start >= block_group->key.objectid +
972 block_group->key.offset)
973 break;
974
975 extent_start = max(extent_start, start);
976 extent_end = min(block_group->key.objectid +
977 block_group->key.offset, extent_end + 1);
978 len = extent_end - extent_start;
979
980 entries++;
981 ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL);
982 if (ret)
983 goto out_nospc;
984
985 start = extent_end;
986 }
987
988 /* Write out the bitmaps */
989 list_for_each_safe(pos, n, &bitmap_list) {
990 struct btrfs_free_space *entry =
991 list_entry(pos, struct btrfs_free_space, list);
992
993 ret = io_ctl_add_bitmap(&io_ctl, entry->bitmap);
994 if (ret)
995 goto out_nospc;
996 list_del_init(&entry->list);
997 }
998
999 /* Zero out the rest of the pages just to make sure */
1000 io_ctl_zero_remaining_pages(&io_ctl);
1001
1002 ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
1003 0, i_size_read(inode), &cached_state);
1004 io_ctl_drop_pages(&io_ctl);
1005 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1006 i_size_read(inode) - 1, &cached_state, GFP_NOFS);
1007
1008 if (ret)
1009 goto out;
1010
1011 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1012 if (ret) {
1013 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1014 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
1015 GFP_NOFS);
1016 goto out;
1017 }
1018
1019 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1020 key.offset = offset;
1021 key.type = 0;
1022
1023 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1024 if (ret < 0) {
1025 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1026 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
1027 GFP_NOFS);
1028 goto out;
1029 }
1030 leaf = path->nodes[0];
1031 if (ret > 0) {
1032 struct btrfs_key found_key;
1033 ASSERT(path->slots[0]);
1034 path->slots[0]--;
1035 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1036 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1037 found_key.offset != offset) {
1038 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1039 inode->i_size - 1,
1040 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
1041 NULL, GFP_NOFS);
1042 btrfs_release_path(path);
1043 goto out;
1044 }
1045 }
1046
1047 BTRFS_I(inode)->generation = trans->transid;
1048 header = btrfs_item_ptr(leaf, path->slots[0],
1049 struct btrfs_free_space_header);
1050 btrfs_set_free_space_entries(leaf, header, entries);
1051 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1052 btrfs_set_free_space_generation(leaf, header, trans->transid);
1053 btrfs_mark_buffer_dirty(leaf);
1054 btrfs_release_path(path);
1055
1056 err = 0;
1057out:
1058 io_ctl_free(&io_ctl);
1059 if (err) {
1060 invalidate_inode_pages2(inode->i_mapping);
1061 BTRFS_I(inode)->generation = 0;
1062 }
1063 btrfs_update_inode(trans, root, inode);
1064 return err;
1065
1066out_nospc:
1067 list_for_each_safe(pos, n, &bitmap_list) {
1068 struct btrfs_free_space *entry =
1069 list_entry(pos, struct btrfs_free_space, list);
1070 list_del_init(&entry->list);
1071 }
1072 io_ctl_drop_pages(&io_ctl);
1073 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1074 i_size_read(inode) - 1, &cached_state, GFP_NOFS);
1075 goto out;
1076}
1077
1078int btrfs_write_out_cache(struct btrfs_root *root,
1079 struct btrfs_trans_handle *trans,
1080 struct btrfs_block_group_cache *block_group,
1081 struct btrfs_path *path)
1082{
1083 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1084 struct inode *inode;
1085 int ret = 0;
1086
1087 root = root->fs_info->tree_root;
1088
1089 spin_lock(&block_group->lock);
1090 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1091 spin_unlock(&block_group->lock);
1092 return 0;
1093 }
1094 spin_unlock(&block_group->lock);
1095
1096 inode = lookup_free_space_inode(root, block_group, path);
1097 if (IS_ERR(inode))
1098 return 0;
1099
1100 ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans,
1101 path, block_group->key.objectid);
1102 if (ret) {
1103 spin_lock(&block_group->lock);
1104 block_group->disk_cache_state = BTRFS_DC_ERROR;
1105 spin_unlock(&block_group->lock);
1106 ret = 0;
1107#ifdef DEBUG
1108 btrfs_err(root->fs_info,
1109 "failed to write free space cache for block group %llu",
1110 block_group->key.objectid);
1111#endif
1112 }
1113
1114 iput(inode);
1115 return ret;
1116}
1117
1118static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1119 u64 offset)
1120{
1121 ASSERT(offset >= bitmap_start);
1122 offset -= bitmap_start;
1123 return (unsigned long)(div_u64(offset, unit));
1124}
1125
1126static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1127{
1128 return (unsigned long)(div_u64(bytes, unit));
1129}
1130
1131static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1132 u64 offset)
1133{
1134 u64 bitmap_start;
1135 u64 bytes_per_bitmap;
1136
1137 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1138 bitmap_start = offset - ctl->start;
1139 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1140 bitmap_start *= bytes_per_bitmap;
1141 bitmap_start += ctl->start;
1142
1143 return bitmap_start;
1144}
1145
1146static int tree_insert_offset(struct rb_root *root, u64 offset,
1147 struct rb_node *node, int bitmap)
1148{
1149 struct rb_node **p = &root->rb_node;
1150 struct rb_node *parent = NULL;
1151 struct btrfs_free_space *info;
1152
1153 while (*p) {
1154 parent = *p;
1155 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1156
1157 if (offset < info->offset) {
1158 p = &(*p)->rb_left;
1159 } else if (offset > info->offset) {
1160 p = &(*p)->rb_right;
1161 } else {
1162 /*
1163 * we could have a bitmap entry and an extent entry
1164 * share the same offset. If this is the case, we want
1165 * the extent entry to always be found first if we do a
1166 * linear search through the tree, since we want to have
1167 * the quickest allocation time, and allocating from an
1168 * extent is faster than allocating from a bitmap. So
1169 * if we're inserting a bitmap and we find an entry at
1170 * this offset, we want to go right, or after this entry
1171 * logically. If we are inserting an extent and we've
1172 * found a bitmap, we want to go left, or before
1173 * logically.
1174 */
1175 if (bitmap) {
1176 if (info->bitmap) {
1177 WARN_ON_ONCE(1);
1178 return -EEXIST;
1179 }
1180 p = &(*p)->rb_right;
1181 } else {
1182 if (!info->bitmap) {
1183 WARN_ON_ONCE(1);
1184 return -EEXIST;
1185 }
1186 p = &(*p)->rb_left;
1187 }
1188 }
1189 }
1190
1191 rb_link_node(node, parent, p);
1192 rb_insert_color(node, root);
1193
1194 return 0;
1195}
1196
1197/*
1198 * searches the tree for the given offset.
1199 *
1200 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1201 * want a section that has at least bytes size and comes at or after the given
1202 * offset.
1203 */
1204static struct btrfs_free_space *
1205tree_search_offset(struct btrfs_free_space_ctl *ctl,
1206 u64 offset, int bitmap_only, int fuzzy)
1207{
1208 struct rb_node *n = ctl->free_space_offset.rb_node;
1209 struct btrfs_free_space *entry, *prev = NULL;
1210
1211 /* find entry that is closest to the 'offset' */
1212 while (1) {
1213 if (!n) {
1214 entry = NULL;
1215 break;
1216 }
1217
1218 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1219 prev = entry;
1220
1221 if (offset < entry->offset)
1222 n = n->rb_left;
1223 else if (offset > entry->offset)
1224 n = n->rb_right;
1225 else
1226 break;
1227 }
1228
1229 if (bitmap_only) {
1230 if (!entry)
1231 return NULL;
1232 if (entry->bitmap)
1233 return entry;
1234
1235 /*
1236 * bitmap entry and extent entry may share same offset,
1237 * in that case, bitmap entry comes after extent entry.
1238 */
1239 n = rb_next(n);
1240 if (!n)
1241 return NULL;
1242 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1243 if (entry->offset != offset)
1244 return NULL;
1245
1246 WARN_ON(!entry->bitmap);
1247 return entry;
1248 } else if (entry) {
1249 if (entry->bitmap) {
1250 /*
1251 * if previous extent entry covers the offset,
1252 * we should return it instead of the bitmap entry
1253 */
1254 n = rb_prev(&entry->offset_index);
1255 if (n) {
1256 prev = rb_entry(n, struct btrfs_free_space,
1257 offset_index);
1258 if (!prev->bitmap &&
1259 prev->offset + prev->bytes > offset)
1260 entry = prev;
1261 }
1262 }
1263 return entry;
1264 }
1265
1266 if (!prev)
1267 return NULL;
1268
1269 /* find last entry before the 'offset' */
1270 entry = prev;
1271 if (entry->offset > offset) {
1272 n = rb_prev(&entry->offset_index);
1273 if (n) {
1274 entry = rb_entry(n, struct btrfs_free_space,
1275 offset_index);
1276 ASSERT(entry->offset <= offset);
1277 } else {
1278 if (fuzzy)
1279 return entry;
1280 else
1281 return NULL;
1282 }
1283 }
1284
1285 if (entry->bitmap) {
1286 n = rb_prev(&entry->offset_index);
1287 if (n) {
1288 prev = rb_entry(n, struct btrfs_free_space,
1289 offset_index);
1290 if (!prev->bitmap &&
1291 prev->offset + prev->bytes > offset)
1292 return prev;
1293 }
1294 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1295 return entry;
1296 } else if (entry->offset + entry->bytes > offset)
1297 return entry;
1298
1299 if (!fuzzy)
1300 return NULL;
1301
1302 while (1) {
1303 if (entry->bitmap) {
1304 if (entry->offset + BITS_PER_BITMAP *
1305 ctl->unit > offset)
1306 break;
1307 } else {
1308 if (entry->offset + entry->bytes > offset)
1309 break;
1310 }
1311
1312 n = rb_next(&entry->offset_index);
1313 if (!n)
1314 return NULL;
1315 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1316 }
1317 return entry;
1318}
1319
1320static inline void
1321__unlink_free_space(struct btrfs_free_space_ctl *ctl,
1322 struct btrfs_free_space *info)
1323{
1324 rb_erase(&info->offset_index, &ctl->free_space_offset);
1325 ctl->free_extents--;
1326}
1327
1328static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1329 struct btrfs_free_space *info)
1330{
1331 __unlink_free_space(ctl, info);
1332 ctl->free_space -= info->bytes;
1333}
1334
1335static int link_free_space(struct btrfs_free_space_ctl *ctl,
1336 struct btrfs_free_space *info)
1337{
1338 int ret = 0;
1339
1340 ASSERT(info->bytes || info->bitmap);
1341 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1342 &info->offset_index, (info->bitmap != NULL));
1343 if (ret)
1344 return ret;
1345
1346 ctl->free_space += info->bytes;
1347 ctl->free_extents++;
1348 return ret;
1349}
1350
1351static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1352{
1353 struct btrfs_block_group_cache *block_group = ctl->private;
1354 u64 max_bytes;
1355 u64 bitmap_bytes;
1356 u64 extent_bytes;
1357 u64 size = block_group->key.offset;
1358 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1359 int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1360
1361 max_bitmaps = max(max_bitmaps, 1);
1362
1363 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1364
1365 /*
1366 * The goal is to keep the total amount of memory used per 1gb of space
1367 * at or below 32k, so we need to adjust how much memory we allow to be
1368 * used by extent based free space tracking
1369 */
1370 if (size < 1024 * 1024 * 1024)
1371 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1372 else
1373 max_bytes = MAX_CACHE_BYTES_PER_GIG *
1374 div64_u64(size, 1024 * 1024 * 1024);
1375
1376 /*
1377 * we want to account for 1 more bitmap than what we have so we can make
1378 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1379 * we add more bitmaps.
1380 */
1381 bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE;
1382
1383 if (bitmap_bytes >= max_bytes) {
1384 ctl->extents_thresh = 0;
1385 return;
1386 }
1387
1388 /*
1389 * we want the extent entry threshold to always be at most 1/2 the maxw
1390 * bytes we can have, or whatever is less than that.
1391 */
1392 extent_bytes = max_bytes - bitmap_bytes;
1393 extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
1394
1395 ctl->extents_thresh =
1396 div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
1397}
1398
1399static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1400 struct btrfs_free_space *info,
1401 u64 offset, u64 bytes)
1402{
1403 unsigned long start, count;
1404
1405 start = offset_to_bit(info->offset, ctl->unit, offset);
1406 count = bytes_to_bits(bytes, ctl->unit);
1407 ASSERT(start + count <= BITS_PER_BITMAP);
1408
1409 bitmap_clear(info->bitmap, start, count);
1410
1411 info->bytes -= bytes;
1412}
1413
1414static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1415 struct btrfs_free_space *info, u64 offset,
1416 u64 bytes)
1417{
1418 __bitmap_clear_bits(ctl, info, offset, bytes);
1419 ctl->free_space -= bytes;
1420}
1421
1422static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1423 struct btrfs_free_space *info, u64 offset,
1424 u64 bytes)
1425{
1426 unsigned long start, count;
1427
1428 start = offset_to_bit(info->offset, ctl->unit, offset);
1429 count = bytes_to_bits(bytes, ctl->unit);
1430 ASSERT(start + count <= BITS_PER_BITMAP);
1431
1432 bitmap_set(info->bitmap, start, count);
1433
1434 info->bytes += bytes;
1435 ctl->free_space += bytes;
1436}
1437
1438/*
1439 * If we can not find suitable extent, we will use bytes to record
1440 * the size of the max extent.
1441 */
1442static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1443 struct btrfs_free_space *bitmap_info, u64 *offset,
1444 u64 *bytes)
1445{
1446 unsigned long found_bits = 0;
1447 unsigned long max_bits = 0;
1448 unsigned long bits, i;
1449 unsigned long next_zero;
1450 unsigned long extent_bits;
1451
1452 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1453 max_t(u64, *offset, bitmap_info->offset));
1454 bits = bytes_to_bits(*bytes, ctl->unit);
1455
1456 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1457 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1458 BITS_PER_BITMAP, i);
1459 extent_bits = next_zero - i;
1460 if (extent_bits >= bits) {
1461 found_bits = extent_bits;
1462 break;
1463 } else if (extent_bits > max_bits) {
1464 max_bits = extent_bits;
1465 }
1466 i = next_zero;
1467 }
1468
1469 if (found_bits) {
1470 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1471 *bytes = (u64)(found_bits) * ctl->unit;
1472 return 0;
1473 }
1474
1475 *bytes = (u64)(max_bits) * ctl->unit;
1476 return -1;
1477}
1478
1479/* Cache the size of the max extent in bytes */
1480static struct btrfs_free_space *
1481find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1482 unsigned long align, u64 *max_extent_size)
1483{
1484 struct btrfs_free_space *entry;
1485 struct rb_node *node;
1486 u64 tmp;
1487 u64 align_off;
1488 int ret;
1489
1490 if (!ctl->free_space_offset.rb_node)
1491 goto out;
1492
1493 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1494 if (!entry)
1495 goto out;
1496
1497 for (node = &entry->offset_index; node; node = rb_next(node)) {
1498 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1499 if (entry->bytes < *bytes) {
1500 if (entry->bytes > *max_extent_size)
1501 *max_extent_size = entry->bytes;
1502 continue;
1503 }
1504
1505 /* make sure the space returned is big enough
1506 * to match our requested alignment
1507 */
1508 if (*bytes >= align) {
1509 tmp = entry->offset - ctl->start + align - 1;
1510 do_div(tmp, align);
1511 tmp = tmp * align + ctl->start;
1512 align_off = tmp - entry->offset;
1513 } else {
1514 align_off = 0;
1515 tmp = entry->offset;
1516 }
1517
1518 if (entry->bytes < *bytes + align_off) {
1519 if (entry->bytes > *max_extent_size)
1520 *max_extent_size = entry->bytes;
1521 continue;
1522 }
1523
1524 if (entry->bitmap) {
1525 u64 size = *bytes;
1526
1527 ret = search_bitmap(ctl, entry, &tmp, &size);
1528 if (!ret) {
1529 *offset = tmp;
1530 *bytes = size;
1531 return entry;
1532 } else if (size > *max_extent_size) {
1533 *max_extent_size = size;
1534 }
1535 continue;
1536 }
1537
1538 *offset = tmp;
1539 *bytes = entry->bytes - align_off;
1540 return entry;
1541 }
1542out:
1543 return NULL;
1544}
1545
1546static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1547 struct btrfs_free_space *info, u64 offset)
1548{
1549 info->offset = offset_to_bitmap(ctl, offset);
1550 info->bytes = 0;
1551 INIT_LIST_HEAD(&info->list);
1552 link_free_space(ctl, info);
1553 ctl->total_bitmaps++;
1554
1555 ctl->op->recalc_thresholds(ctl);
1556}
1557
1558static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1559 struct btrfs_free_space *bitmap_info)
1560{
1561 unlink_free_space(ctl, bitmap_info);
1562 kfree(bitmap_info->bitmap);
1563 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1564 ctl->total_bitmaps--;
1565 ctl->op->recalc_thresholds(ctl);
1566}
1567
1568static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1569 struct btrfs_free_space *bitmap_info,
1570 u64 *offset, u64 *bytes)
1571{
1572 u64 end;
1573 u64 search_start, search_bytes;
1574 int ret;
1575
1576again:
1577 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1578
1579 /*
1580 * We need to search for bits in this bitmap. We could only cover some
1581 * of the extent in this bitmap thanks to how we add space, so we need
1582 * to search for as much as it as we can and clear that amount, and then
1583 * go searching for the next bit.
1584 */
1585 search_start = *offset;
1586 search_bytes = ctl->unit;
1587 search_bytes = min(search_bytes, end - search_start + 1);
1588 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes);
1589 if (ret < 0 || search_start != *offset)
1590 return -EINVAL;
1591
1592 /* We may have found more bits than what we need */
1593 search_bytes = min(search_bytes, *bytes);
1594
1595 /* Cannot clear past the end of the bitmap */
1596 search_bytes = min(search_bytes, end - search_start + 1);
1597
1598 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1599 *offset += search_bytes;
1600 *bytes -= search_bytes;
1601
1602 if (*bytes) {
1603 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1604 if (!bitmap_info->bytes)
1605 free_bitmap(ctl, bitmap_info);
1606
1607 /*
1608 * no entry after this bitmap, but we still have bytes to
1609 * remove, so something has gone wrong.
1610 */
1611 if (!next)
1612 return -EINVAL;
1613
1614 bitmap_info = rb_entry(next, struct btrfs_free_space,
1615 offset_index);
1616
1617 /*
1618 * if the next entry isn't a bitmap we need to return to let the
1619 * extent stuff do its work.
1620 */
1621 if (!bitmap_info->bitmap)
1622 return -EAGAIN;
1623
1624 /*
1625 * Ok the next item is a bitmap, but it may not actually hold
1626 * the information for the rest of this free space stuff, so
1627 * look for it, and if we don't find it return so we can try
1628 * everything over again.
1629 */
1630 search_start = *offset;
1631 search_bytes = ctl->unit;
1632 ret = search_bitmap(ctl, bitmap_info, &search_start,
1633 &search_bytes);
1634 if (ret < 0 || search_start != *offset)
1635 return -EAGAIN;
1636
1637 goto again;
1638 } else if (!bitmap_info->bytes)
1639 free_bitmap(ctl, bitmap_info);
1640
1641 return 0;
1642}
1643
1644static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1645 struct btrfs_free_space *info, u64 offset,
1646 u64 bytes)
1647{
1648 u64 bytes_to_set = 0;
1649 u64 end;
1650
1651 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1652
1653 bytes_to_set = min(end - offset, bytes);
1654
1655 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1656
1657 return bytes_to_set;
1658
1659}
1660
1661static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1662 struct btrfs_free_space *info)
1663{
1664 struct btrfs_block_group_cache *block_group = ctl->private;
1665
1666 /*
1667 * If we are below the extents threshold then we can add this as an
1668 * extent, and don't have to deal with the bitmap
1669 */
1670 if (ctl->free_extents < ctl->extents_thresh) {
1671 /*
1672 * If this block group has some small extents we don't want to
1673 * use up all of our free slots in the cache with them, we want
1674 * to reserve them to larger extents, however if we have plent
1675 * of cache left then go ahead an dadd them, no sense in adding
1676 * the overhead of a bitmap if we don't have to.
1677 */
1678 if (info->bytes <= block_group->sectorsize * 4) {
1679 if (ctl->free_extents * 2 <= ctl->extents_thresh)
1680 return false;
1681 } else {
1682 return false;
1683 }
1684 }
1685
1686 /*
1687 * The original block groups from mkfs can be really small, like 8
1688 * megabytes, so don't bother with a bitmap for those entries. However
1689 * some block groups can be smaller than what a bitmap would cover but
1690 * are still large enough that they could overflow the 32k memory limit,
1691 * so allow those block groups to still be allowed to have a bitmap
1692 * entry.
1693 */
1694 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
1695 return false;
1696
1697 return true;
1698}
1699
1700static struct btrfs_free_space_op free_space_op = {
1701 .recalc_thresholds = recalculate_thresholds,
1702 .use_bitmap = use_bitmap,
1703};
1704
1705static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
1706 struct btrfs_free_space *info)
1707{
1708 struct btrfs_free_space *bitmap_info;
1709 struct btrfs_block_group_cache *block_group = NULL;
1710 int added = 0;
1711 u64 bytes, offset, bytes_added;
1712 int ret;
1713
1714 bytes = info->bytes;
1715 offset = info->offset;
1716
1717 if (!ctl->op->use_bitmap(ctl, info))
1718 return 0;
1719
1720 if (ctl->op == &free_space_op)
1721 block_group = ctl->private;
1722again:
1723 /*
1724 * Since we link bitmaps right into the cluster we need to see if we
1725 * have a cluster here, and if so and it has our bitmap we need to add
1726 * the free space to that bitmap.
1727 */
1728 if (block_group && !list_empty(&block_group->cluster_list)) {
1729 struct btrfs_free_cluster *cluster;
1730 struct rb_node *node;
1731 struct btrfs_free_space *entry;
1732
1733 cluster = list_entry(block_group->cluster_list.next,
1734 struct btrfs_free_cluster,
1735 block_group_list);
1736 spin_lock(&cluster->lock);
1737 node = rb_first(&cluster->root);
1738 if (!node) {
1739 spin_unlock(&cluster->lock);
1740 goto no_cluster_bitmap;
1741 }
1742
1743 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1744 if (!entry->bitmap) {
1745 spin_unlock(&cluster->lock);
1746 goto no_cluster_bitmap;
1747 }
1748
1749 if (entry->offset == offset_to_bitmap(ctl, offset)) {
1750 bytes_added = add_bytes_to_bitmap(ctl, entry,
1751 offset, bytes);
1752 bytes -= bytes_added;
1753 offset += bytes_added;
1754 }
1755 spin_unlock(&cluster->lock);
1756 if (!bytes) {
1757 ret = 1;
1758 goto out;
1759 }
1760 }
1761
1762no_cluster_bitmap:
1763 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1764 1, 0);
1765 if (!bitmap_info) {
1766 ASSERT(added == 0);
1767 goto new_bitmap;
1768 }
1769
1770 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
1771 bytes -= bytes_added;
1772 offset += bytes_added;
1773 added = 0;
1774
1775 if (!bytes) {
1776 ret = 1;
1777 goto out;
1778 } else
1779 goto again;
1780
1781new_bitmap:
1782 if (info && info->bitmap) {
1783 add_new_bitmap(ctl, info, offset);
1784 added = 1;
1785 info = NULL;
1786 goto again;
1787 } else {
1788 spin_unlock(&ctl->tree_lock);
1789
1790 /* no pre-allocated info, allocate a new one */
1791 if (!info) {
1792 info = kmem_cache_zalloc(btrfs_free_space_cachep,
1793 GFP_NOFS);
1794 if (!info) {
1795 spin_lock(&ctl->tree_lock);
1796 ret = -ENOMEM;
1797 goto out;
1798 }
1799 }
1800
1801 /* allocate the bitmap */
1802 info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
1803 spin_lock(&ctl->tree_lock);
1804 if (!info->bitmap) {
1805 ret = -ENOMEM;
1806 goto out;
1807 }
1808 goto again;
1809 }
1810
1811out:
1812 if (info) {
1813 if (info->bitmap)
1814 kfree(info->bitmap);
1815 kmem_cache_free(btrfs_free_space_cachep, info);
1816 }
1817
1818 return ret;
1819}
1820
1821static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
1822 struct btrfs_free_space *info, bool update_stat)
1823{
1824 struct btrfs_free_space *left_info;
1825 struct btrfs_free_space *right_info;
1826 bool merged = false;
1827 u64 offset = info->offset;
1828 u64 bytes = info->bytes;
1829
1830 /*
1831 * first we want to see if there is free space adjacent to the range we
1832 * are adding, if there is remove that struct and add a new one to
1833 * cover the entire range
1834 */
1835 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
1836 if (right_info && rb_prev(&right_info->offset_index))
1837 left_info = rb_entry(rb_prev(&right_info->offset_index),
1838 struct btrfs_free_space, offset_index);
1839 else
1840 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
1841
1842 if (right_info && !right_info->bitmap) {
1843 if (update_stat)
1844 unlink_free_space(ctl, right_info);
1845 else
1846 __unlink_free_space(ctl, right_info);
1847 info->bytes += right_info->bytes;
1848 kmem_cache_free(btrfs_free_space_cachep, right_info);
1849 merged = true;
1850 }
1851
1852 if (left_info && !left_info->bitmap &&
1853 left_info->offset + left_info->bytes == offset) {
1854 if (update_stat)
1855 unlink_free_space(ctl, left_info);
1856 else
1857 __unlink_free_space(ctl, left_info);
1858 info->offset = left_info->offset;
1859 info->bytes += left_info->bytes;
1860 kmem_cache_free(btrfs_free_space_cachep, left_info);
1861 merged = true;
1862 }
1863
1864 return merged;
1865}
1866
1867int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl,
1868 u64 offset, u64 bytes)
1869{
1870 struct btrfs_free_space *info;
1871 int ret = 0;
1872
1873 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
1874 if (!info)
1875 return -ENOMEM;
1876
1877 info->offset = offset;
1878 info->bytes = bytes;
1879
1880 spin_lock(&ctl->tree_lock);
1881
1882 if (try_merge_free_space(ctl, info, true))
1883 goto link;
1884
1885 /*
1886 * There was no extent directly to the left or right of this new
1887 * extent then we know we're going to have to allocate a new extent, so
1888 * before we do that see if we need to drop this into a bitmap
1889 */
1890 ret = insert_into_bitmap(ctl, info);
1891 if (ret < 0) {
1892 goto out;
1893 } else if (ret) {
1894 ret = 0;
1895 goto out;
1896 }
1897link:
1898 ret = link_free_space(ctl, info);
1899 if (ret)
1900 kmem_cache_free(btrfs_free_space_cachep, info);
1901out:
1902 spin_unlock(&ctl->tree_lock);
1903
1904 if (ret) {
1905 printk(KERN_CRIT "BTRFS: unable to add free space :%d\n", ret);
1906 ASSERT(ret != -EEXIST);
1907 }
1908
1909 return ret;
1910}
1911
1912int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
1913 u64 offset, u64 bytes)
1914{
1915 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1916 struct btrfs_free_space *info;
1917 int ret;
1918 bool re_search = false;
1919
1920 spin_lock(&ctl->tree_lock);
1921
1922again:
1923 ret = 0;
1924 if (!bytes)
1925 goto out_lock;
1926
1927 info = tree_search_offset(ctl, offset, 0, 0);
1928 if (!info) {
1929 /*
1930 * oops didn't find an extent that matched the space we wanted
1931 * to remove, look for a bitmap instead
1932 */
1933 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1934 1, 0);
1935 if (!info) {
1936 /*
1937 * If we found a partial bit of our free space in a
1938 * bitmap but then couldn't find the other part this may
1939 * be a problem, so WARN about it.
1940 */
1941 WARN_ON(re_search);
1942 goto out_lock;
1943 }
1944 }
1945
1946 re_search = false;
1947 if (!info->bitmap) {
1948 unlink_free_space(ctl, info);
1949 if (offset == info->offset) {
1950 u64 to_free = min(bytes, info->bytes);
1951
1952 info->bytes -= to_free;
1953 info->offset += to_free;
1954 if (info->bytes) {
1955 ret = link_free_space(ctl, info);
1956 WARN_ON(ret);
1957 } else {
1958 kmem_cache_free(btrfs_free_space_cachep, info);
1959 }
1960
1961 offset += to_free;
1962 bytes -= to_free;
1963 goto again;
1964 } else {
1965 u64 old_end = info->bytes + info->offset;
1966
1967 info->bytes = offset - info->offset;
1968 ret = link_free_space(ctl, info);
1969 WARN_ON(ret);
1970 if (ret)
1971 goto out_lock;
1972
1973 /* Not enough bytes in this entry to satisfy us */
1974 if (old_end < offset + bytes) {
1975 bytes -= old_end - offset;
1976 offset = old_end;
1977 goto again;
1978 } else if (old_end == offset + bytes) {
1979 /* all done */
1980 goto out_lock;
1981 }
1982 spin_unlock(&ctl->tree_lock);
1983
1984 ret = btrfs_add_free_space(block_group, offset + bytes,
1985 old_end - (offset + bytes));
1986 WARN_ON(ret);
1987 goto out;
1988 }
1989 }
1990
1991 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
1992 if (ret == -EAGAIN) {
1993 re_search = true;
1994 goto again;
1995 }
1996out_lock:
1997 spin_unlock(&ctl->tree_lock);
1998out:
1999 return ret;
2000}
2001
2002void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2003 u64 bytes)
2004{
2005 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2006 struct btrfs_free_space *info;
2007 struct rb_node *n;
2008 int count = 0;
2009
2010 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2011 info = rb_entry(n, struct btrfs_free_space, offset_index);
2012 if (info->bytes >= bytes && !block_group->ro)
2013 count++;
2014 btrfs_crit(block_group->fs_info,
2015 "entry offset %llu, bytes %llu, bitmap %s",
2016 info->offset, info->bytes,
2017 (info->bitmap) ? "yes" : "no");
2018 }
2019 btrfs_info(block_group->fs_info, "block group has cluster?: %s",
2020 list_empty(&block_group->cluster_list) ? "no" : "yes");
2021 btrfs_info(block_group->fs_info,
2022 "%d blocks of free space at or bigger than bytes is", count);
2023}
2024
2025void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2026{
2027 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2028
2029 spin_lock_init(&ctl->tree_lock);
2030 ctl->unit = block_group->sectorsize;
2031 ctl->start = block_group->key.objectid;
2032 ctl->private = block_group;
2033 ctl->op = &free_space_op;
2034
2035 /*
2036 * we only want to have 32k of ram per block group for keeping
2037 * track of free space, and if we pass 1/2 of that we want to
2038 * start converting things over to using bitmaps
2039 */
2040 ctl->extents_thresh = ((1024 * 32) / 2) /
2041 sizeof(struct btrfs_free_space);
2042}
2043
2044/*
2045 * for a given cluster, put all of its extents back into the free
2046 * space cache. If the block group passed doesn't match the block group
2047 * pointed to by the cluster, someone else raced in and freed the
2048 * cluster already. In that case, we just return without changing anything
2049 */
2050static int
2051__btrfs_return_cluster_to_free_space(
2052 struct btrfs_block_group_cache *block_group,
2053 struct btrfs_free_cluster *cluster)
2054{
2055 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2056 struct btrfs_free_space *entry;
2057 struct rb_node *node;
2058
2059 spin_lock(&cluster->lock);
2060 if (cluster->block_group != block_group)
2061 goto out;
2062
2063 cluster->block_group = NULL;
2064 cluster->window_start = 0;
2065 list_del_init(&cluster->block_group_list);
2066
2067 node = rb_first(&cluster->root);
2068 while (node) {
2069 bool bitmap;
2070
2071 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2072 node = rb_next(&entry->offset_index);
2073 rb_erase(&entry->offset_index, &cluster->root);
2074
2075 bitmap = (entry->bitmap != NULL);
2076 if (!bitmap)
2077 try_merge_free_space(ctl, entry, false);
2078 tree_insert_offset(&ctl->free_space_offset,
2079 entry->offset, &entry->offset_index, bitmap);
2080 }
2081 cluster->root = RB_ROOT;
2082
2083out:
2084 spin_unlock(&cluster->lock);
2085 btrfs_put_block_group(block_group);
2086 return 0;
2087}
2088
2089static void __btrfs_remove_free_space_cache_locked(
2090 struct btrfs_free_space_ctl *ctl)
2091{
2092 struct btrfs_free_space *info;
2093 struct rb_node *node;
2094
2095 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2096 info = rb_entry(node, struct btrfs_free_space, offset_index);
2097 if (!info->bitmap) {
2098 unlink_free_space(ctl, info);
2099 kmem_cache_free(btrfs_free_space_cachep, info);
2100 } else {
2101 free_bitmap(ctl, info);
2102 }
2103 if (need_resched()) {
2104 spin_unlock(&ctl->tree_lock);
2105 cond_resched();
2106 spin_lock(&ctl->tree_lock);
2107 }
2108 }
2109}
2110
2111void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2112{
2113 spin_lock(&ctl->tree_lock);
2114 __btrfs_remove_free_space_cache_locked(ctl);
2115 spin_unlock(&ctl->tree_lock);
2116}
2117
2118void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2119{
2120 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2121 struct btrfs_free_cluster *cluster;
2122 struct list_head *head;
2123
2124 spin_lock(&ctl->tree_lock);
2125 while ((head = block_group->cluster_list.next) !=
2126 &block_group->cluster_list) {
2127 cluster = list_entry(head, struct btrfs_free_cluster,
2128 block_group_list);
2129
2130 WARN_ON(cluster->block_group != block_group);
2131 __btrfs_return_cluster_to_free_space(block_group, cluster);
2132 if (need_resched()) {
2133 spin_unlock(&ctl->tree_lock);
2134 cond_resched();
2135 spin_lock(&ctl->tree_lock);
2136 }
2137 }
2138 __btrfs_remove_free_space_cache_locked(ctl);
2139 spin_unlock(&ctl->tree_lock);
2140
2141}
2142
2143u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2144 u64 offset, u64 bytes, u64 empty_size,
2145 u64 *max_extent_size)
2146{
2147 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2148 struct btrfs_free_space *entry = NULL;
2149 u64 bytes_search = bytes + empty_size;
2150 u64 ret = 0;
2151 u64 align_gap = 0;
2152 u64 align_gap_len = 0;
2153
2154 spin_lock(&ctl->tree_lock);
2155 entry = find_free_space(ctl, &offset, &bytes_search,
2156 block_group->full_stripe_len, max_extent_size);
2157 if (!entry)
2158 goto out;
2159
2160 ret = offset;
2161 if (entry->bitmap) {
2162 bitmap_clear_bits(ctl, entry, offset, bytes);
2163 if (!entry->bytes)
2164 free_bitmap(ctl, entry);
2165 } else {
2166 unlink_free_space(ctl, entry);
2167 align_gap_len = offset - entry->offset;
2168 align_gap = entry->offset;
2169
2170 entry->offset = offset + bytes;
2171 WARN_ON(entry->bytes < bytes + align_gap_len);
2172
2173 entry->bytes -= bytes + align_gap_len;
2174 if (!entry->bytes)
2175 kmem_cache_free(btrfs_free_space_cachep, entry);
2176 else
2177 link_free_space(ctl, entry);
2178 }
2179out:
2180 spin_unlock(&ctl->tree_lock);
2181
2182 if (align_gap_len)
2183 __btrfs_add_free_space(ctl, align_gap, align_gap_len);
2184 return ret;
2185}
2186
2187/*
2188 * given a cluster, put all of its extents back into the free space
2189 * cache. If a block group is passed, this function will only free
2190 * a cluster that belongs to the passed block group.
2191 *
2192 * Otherwise, it'll get a reference on the block group pointed to by the
2193 * cluster and remove the cluster from it.
2194 */
2195int btrfs_return_cluster_to_free_space(
2196 struct btrfs_block_group_cache *block_group,
2197 struct btrfs_free_cluster *cluster)
2198{
2199 struct btrfs_free_space_ctl *ctl;
2200 int ret;
2201
2202 /* first, get a safe pointer to the block group */
2203 spin_lock(&cluster->lock);
2204 if (!block_group) {
2205 block_group = cluster->block_group;
2206 if (!block_group) {
2207 spin_unlock(&cluster->lock);
2208 return 0;
2209 }
2210 } else if (cluster->block_group != block_group) {
2211 /* someone else has already freed it don't redo their work */
2212 spin_unlock(&cluster->lock);
2213 return 0;
2214 }
2215 atomic_inc(&block_group->count);
2216 spin_unlock(&cluster->lock);
2217
2218 ctl = block_group->free_space_ctl;
2219
2220 /* now return any extents the cluster had on it */
2221 spin_lock(&ctl->tree_lock);
2222 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2223 spin_unlock(&ctl->tree_lock);
2224
2225 /* finally drop our ref */
2226 btrfs_put_block_group(block_group);
2227 return ret;
2228}
2229
2230static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2231 struct btrfs_free_cluster *cluster,
2232 struct btrfs_free_space *entry,
2233 u64 bytes, u64 min_start,
2234 u64 *max_extent_size)
2235{
2236 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2237 int err;
2238 u64 search_start = cluster->window_start;
2239 u64 search_bytes = bytes;
2240 u64 ret = 0;
2241
2242 search_start = min_start;
2243 search_bytes = bytes;
2244
2245 err = search_bitmap(ctl, entry, &search_start, &search_bytes);
2246 if (err) {
2247 if (search_bytes > *max_extent_size)
2248 *max_extent_size = search_bytes;
2249 return 0;
2250 }
2251
2252 ret = search_start;
2253 __bitmap_clear_bits(ctl, entry, ret, bytes);
2254
2255 return ret;
2256}
2257
2258/*
2259 * given a cluster, try to allocate 'bytes' from it, returns 0
2260 * if it couldn't find anything suitably large, or a logical disk offset
2261 * if things worked out
2262 */
2263u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2264 struct btrfs_free_cluster *cluster, u64 bytes,
2265 u64 min_start, u64 *max_extent_size)
2266{
2267 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2268 struct btrfs_free_space *entry = NULL;
2269 struct rb_node *node;
2270 u64 ret = 0;
2271
2272 spin_lock(&cluster->lock);
2273 if (bytes > cluster->max_size)
2274 goto out;
2275
2276 if (cluster->block_group != block_group)
2277 goto out;
2278
2279 node = rb_first(&cluster->root);
2280 if (!node)
2281 goto out;
2282
2283 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2284 while (1) {
2285 if (entry->bytes < bytes && entry->bytes > *max_extent_size)
2286 *max_extent_size = entry->bytes;
2287
2288 if (entry->bytes < bytes ||
2289 (!entry->bitmap && entry->offset < min_start)) {
2290 node = rb_next(&entry->offset_index);
2291 if (!node)
2292 break;
2293 entry = rb_entry(node, struct btrfs_free_space,
2294 offset_index);
2295 continue;
2296 }
2297
2298 if (entry->bitmap) {
2299 ret = btrfs_alloc_from_bitmap(block_group,
2300 cluster, entry, bytes,
2301 cluster->window_start,
2302 max_extent_size);
2303 if (ret == 0) {
2304 node = rb_next(&entry->offset_index);
2305 if (!node)
2306 break;
2307 entry = rb_entry(node, struct btrfs_free_space,
2308 offset_index);
2309 continue;
2310 }
2311 cluster->window_start += bytes;
2312 } else {
2313 ret = entry->offset;
2314
2315 entry->offset += bytes;
2316 entry->bytes -= bytes;
2317 }
2318
2319 if (entry->bytes == 0)
2320 rb_erase(&entry->offset_index, &cluster->root);
2321 break;
2322 }
2323out:
2324 spin_unlock(&cluster->lock);
2325
2326 if (!ret)
2327 return 0;
2328
2329 spin_lock(&ctl->tree_lock);
2330
2331 ctl->free_space -= bytes;
2332 if (entry->bytes == 0) {
2333 ctl->free_extents--;
2334 if (entry->bitmap) {
2335 kfree(entry->bitmap);
2336 ctl->total_bitmaps--;
2337 ctl->op->recalc_thresholds(ctl);
2338 }
2339 kmem_cache_free(btrfs_free_space_cachep, entry);
2340 }
2341
2342 spin_unlock(&ctl->tree_lock);
2343
2344 return ret;
2345}
2346
2347static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2348 struct btrfs_free_space *entry,
2349 struct btrfs_free_cluster *cluster,
2350 u64 offset, u64 bytes,
2351 u64 cont1_bytes, u64 min_bytes)
2352{
2353 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2354 unsigned long next_zero;
2355 unsigned long i;
2356 unsigned long want_bits;
2357 unsigned long min_bits;
2358 unsigned long found_bits;
2359 unsigned long start = 0;
2360 unsigned long total_found = 0;
2361 int ret;
2362
2363 i = offset_to_bit(entry->offset, ctl->unit,
2364 max_t(u64, offset, entry->offset));
2365 want_bits = bytes_to_bits(bytes, ctl->unit);
2366 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2367
2368again:
2369 found_bits = 0;
2370 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2371 next_zero = find_next_zero_bit(entry->bitmap,
2372 BITS_PER_BITMAP, i);
2373 if (next_zero - i >= min_bits) {
2374 found_bits = next_zero - i;
2375 break;
2376 }
2377 i = next_zero;
2378 }
2379
2380 if (!found_bits)
2381 return -ENOSPC;
2382
2383 if (!total_found) {
2384 start = i;
2385 cluster->max_size = 0;
2386 }
2387
2388 total_found += found_bits;
2389
2390 if (cluster->max_size < found_bits * ctl->unit)
2391 cluster->max_size = found_bits * ctl->unit;
2392
2393 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2394 i = next_zero + 1;
2395 goto again;
2396 }
2397
2398 cluster->window_start = start * ctl->unit + entry->offset;
2399 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2400 ret = tree_insert_offset(&cluster->root, entry->offset,
2401 &entry->offset_index, 1);
2402 ASSERT(!ret); /* -EEXIST; Logic error */
2403
2404 trace_btrfs_setup_cluster(block_group, cluster,
2405 total_found * ctl->unit, 1);
2406 return 0;
2407}
2408
2409/*
2410 * This searches the block group for just extents to fill the cluster with.
2411 * Try to find a cluster with at least bytes total bytes, at least one
2412 * extent of cont1_bytes, and other clusters of at least min_bytes.
2413 */
2414static noinline int
2415setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2416 struct btrfs_free_cluster *cluster,
2417 struct list_head *bitmaps, u64 offset, u64 bytes,
2418 u64 cont1_bytes, u64 min_bytes)
2419{
2420 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2421 struct btrfs_free_space *first = NULL;
2422 struct btrfs_free_space *entry = NULL;
2423 struct btrfs_free_space *last;
2424 struct rb_node *node;
2425 u64 window_free;
2426 u64 max_extent;
2427 u64 total_size = 0;
2428
2429 entry = tree_search_offset(ctl, offset, 0, 1);
2430 if (!entry)
2431 return -ENOSPC;
2432
2433 /*
2434 * We don't want bitmaps, so just move along until we find a normal
2435 * extent entry.
2436 */
2437 while (entry->bitmap || entry->bytes < min_bytes) {
2438 if (entry->bitmap && list_empty(&entry->list))
2439 list_add_tail(&entry->list, bitmaps);
2440 node = rb_next(&entry->offset_index);
2441 if (!node)
2442 return -ENOSPC;
2443 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2444 }
2445
2446 window_free = entry->bytes;
2447 max_extent = entry->bytes;
2448 first = entry;
2449 last = entry;
2450
2451 for (node = rb_next(&entry->offset_index); node;
2452 node = rb_next(&entry->offset_index)) {
2453 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2454
2455 if (entry->bitmap) {
2456 if (list_empty(&entry->list))
2457 list_add_tail(&entry->list, bitmaps);
2458 continue;
2459 }
2460
2461 if (entry->bytes < min_bytes)
2462 continue;
2463
2464 last = entry;
2465 window_free += entry->bytes;
2466 if (entry->bytes > max_extent)
2467 max_extent = entry->bytes;
2468 }
2469
2470 if (window_free < bytes || max_extent < cont1_bytes)
2471 return -ENOSPC;
2472
2473 cluster->window_start = first->offset;
2474
2475 node = &first->offset_index;
2476
2477 /*
2478 * now we've found our entries, pull them out of the free space
2479 * cache and put them into the cluster rbtree
2480 */
2481 do {
2482 int ret;
2483
2484 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2485 node = rb_next(&entry->offset_index);
2486 if (entry->bitmap || entry->bytes < min_bytes)
2487 continue;
2488
2489 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2490 ret = tree_insert_offset(&cluster->root, entry->offset,
2491 &entry->offset_index, 0);
2492 total_size += entry->bytes;
2493 ASSERT(!ret); /* -EEXIST; Logic error */
2494 } while (node && entry != last);
2495
2496 cluster->max_size = max_extent;
2497 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2498 return 0;
2499}
2500
2501/*
2502 * This specifically looks for bitmaps that may work in the cluster, we assume
2503 * that we have already failed to find extents that will work.
2504 */
2505static noinline int
2506setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
2507 struct btrfs_free_cluster *cluster,
2508 struct list_head *bitmaps, u64 offset, u64 bytes,
2509 u64 cont1_bytes, u64 min_bytes)
2510{
2511 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2512 struct btrfs_free_space *entry;
2513 int ret = -ENOSPC;
2514 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
2515
2516 if (ctl->total_bitmaps == 0)
2517 return -ENOSPC;
2518
2519 /*
2520 * The bitmap that covers offset won't be in the list unless offset
2521 * is just its start offset.
2522 */
2523 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
2524 if (entry->offset != bitmap_offset) {
2525 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
2526 if (entry && list_empty(&entry->list))
2527 list_add(&entry->list, bitmaps);
2528 }
2529
2530 list_for_each_entry(entry, bitmaps, list) {
2531 if (entry->bytes < bytes)
2532 continue;
2533 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
2534 bytes, cont1_bytes, min_bytes);
2535 if (!ret)
2536 return 0;
2537 }
2538
2539 /*
2540 * The bitmaps list has all the bitmaps that record free space
2541 * starting after offset, so no more search is required.
2542 */
2543 return -ENOSPC;
2544}
2545
2546/*
2547 * here we try to find a cluster of blocks in a block group. The goal
2548 * is to find at least bytes+empty_size.
2549 * We might not find them all in one contiguous area.
2550 *
2551 * returns zero and sets up cluster if things worked out, otherwise
2552 * it returns -enospc
2553 */
2554int btrfs_find_space_cluster(struct btrfs_root *root,
2555 struct btrfs_block_group_cache *block_group,
2556 struct btrfs_free_cluster *cluster,
2557 u64 offset, u64 bytes, u64 empty_size)
2558{
2559 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2560 struct btrfs_free_space *entry, *tmp;
2561 LIST_HEAD(bitmaps);
2562 u64 min_bytes;
2563 u64 cont1_bytes;
2564 int ret;
2565
2566 /*
2567 * Choose the minimum extent size we'll require for this
2568 * cluster. For SSD_SPREAD, don't allow any fragmentation.
2569 * For metadata, allow allocates with smaller extents. For
2570 * data, keep it dense.
2571 */
2572 if (btrfs_test_opt(root, SSD_SPREAD)) {
2573 cont1_bytes = min_bytes = bytes + empty_size;
2574 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
2575 cont1_bytes = bytes;
2576 min_bytes = block_group->sectorsize;
2577 } else {
2578 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
2579 min_bytes = block_group->sectorsize;
2580 }
2581
2582 spin_lock(&ctl->tree_lock);
2583
2584 /*
2585 * If we know we don't have enough space to make a cluster don't even
2586 * bother doing all the work to try and find one.
2587 */
2588 if (ctl->free_space < bytes) {
2589 spin_unlock(&ctl->tree_lock);
2590 return -ENOSPC;
2591 }
2592
2593 spin_lock(&cluster->lock);
2594
2595 /* someone already found a cluster, hooray */
2596 if (cluster->block_group) {
2597 ret = 0;
2598 goto out;
2599 }
2600
2601 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
2602 min_bytes);
2603
2604 INIT_LIST_HEAD(&bitmaps);
2605 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
2606 bytes + empty_size,
2607 cont1_bytes, min_bytes);
2608 if (ret)
2609 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
2610 offset, bytes + empty_size,
2611 cont1_bytes, min_bytes);
2612
2613 /* Clear our temporary list */
2614 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
2615 list_del_init(&entry->list);
2616
2617 if (!ret) {
2618 atomic_inc(&block_group->count);
2619 list_add_tail(&cluster->block_group_list,
2620 &block_group->cluster_list);
2621 cluster->block_group = block_group;
2622 } else {
2623 trace_btrfs_failed_cluster_setup(block_group);
2624 }
2625out:
2626 spin_unlock(&cluster->lock);
2627 spin_unlock(&ctl->tree_lock);
2628
2629 return ret;
2630}
2631
2632/*
2633 * simple code to zero out a cluster
2634 */
2635void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
2636{
2637 spin_lock_init(&cluster->lock);
2638 spin_lock_init(&cluster->refill_lock);
2639 cluster->root = RB_ROOT;
2640 cluster->max_size = 0;
2641 INIT_LIST_HEAD(&cluster->block_group_list);
2642 cluster->block_group = NULL;
2643}
2644
2645static int do_trimming(struct btrfs_block_group_cache *block_group,
2646 u64 *total_trimmed, u64 start, u64 bytes,
2647 u64 reserved_start, u64 reserved_bytes)
2648{
2649 struct btrfs_space_info *space_info = block_group->space_info;
2650 struct btrfs_fs_info *fs_info = block_group->fs_info;
2651 int ret;
2652 int update = 0;
2653 u64 trimmed = 0;
2654
2655 spin_lock(&space_info->lock);
2656 spin_lock(&block_group->lock);
2657 if (!block_group->ro) {
2658 block_group->reserved += reserved_bytes;
2659 space_info->bytes_reserved += reserved_bytes;
2660 update = 1;
2661 }
2662 spin_unlock(&block_group->lock);
2663 spin_unlock(&space_info->lock);
2664
2665 ret = btrfs_error_discard_extent(fs_info->extent_root,
2666 start, bytes, &trimmed);
2667 if (!ret)
2668 *total_trimmed += trimmed;
2669
2670 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
2671
2672 if (update) {
2673 spin_lock(&space_info->lock);
2674 spin_lock(&block_group->lock);
2675 if (block_group->ro)
2676 space_info->bytes_readonly += reserved_bytes;
2677 block_group->reserved -= reserved_bytes;
2678 space_info->bytes_reserved -= reserved_bytes;
2679 spin_unlock(&space_info->lock);
2680 spin_unlock(&block_group->lock);
2681 }
2682
2683 return ret;
2684}
2685
2686static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
2687 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
2688{
2689 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2690 struct btrfs_free_space *entry;
2691 struct rb_node *node;
2692 int ret = 0;
2693 u64 extent_start;
2694 u64 extent_bytes;
2695 u64 bytes;
2696
2697 while (start < end) {
2698 spin_lock(&ctl->tree_lock);
2699
2700 if (ctl->free_space < minlen) {
2701 spin_unlock(&ctl->tree_lock);
2702 break;
2703 }
2704
2705 entry = tree_search_offset(ctl, start, 0, 1);
2706 if (!entry) {
2707 spin_unlock(&ctl->tree_lock);
2708 break;
2709 }
2710
2711 /* skip bitmaps */
2712 while (entry->bitmap) {
2713 node = rb_next(&entry->offset_index);
2714 if (!node) {
2715 spin_unlock(&ctl->tree_lock);
2716 goto out;
2717 }
2718 entry = rb_entry(node, struct btrfs_free_space,
2719 offset_index);
2720 }
2721
2722 if (entry->offset >= end) {
2723 spin_unlock(&ctl->tree_lock);
2724 break;
2725 }
2726
2727 extent_start = entry->offset;
2728 extent_bytes = entry->bytes;
2729 start = max(start, extent_start);
2730 bytes = min(extent_start + extent_bytes, end) - start;
2731 if (bytes < minlen) {
2732 spin_unlock(&ctl->tree_lock);
2733 goto next;
2734 }
2735
2736 unlink_free_space(ctl, entry);
2737 kmem_cache_free(btrfs_free_space_cachep, entry);
2738
2739 spin_unlock(&ctl->tree_lock);
2740
2741 ret = do_trimming(block_group, total_trimmed, start, bytes,
2742 extent_start, extent_bytes);
2743 if (ret)
2744 break;
2745next:
2746 start += bytes;
2747
2748 if (fatal_signal_pending(current)) {
2749 ret = -ERESTARTSYS;
2750 break;
2751 }
2752
2753 cond_resched();
2754 }
2755out:
2756 return ret;
2757}
2758
2759static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
2760 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
2761{
2762 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2763 struct btrfs_free_space *entry;
2764 int ret = 0;
2765 int ret2;
2766 u64 bytes;
2767 u64 offset = offset_to_bitmap(ctl, start);
2768
2769 while (offset < end) {
2770 bool next_bitmap = false;
2771
2772 spin_lock(&ctl->tree_lock);
2773
2774 if (ctl->free_space < minlen) {
2775 spin_unlock(&ctl->tree_lock);
2776 break;
2777 }
2778
2779 entry = tree_search_offset(ctl, offset, 1, 0);
2780 if (!entry) {
2781 spin_unlock(&ctl->tree_lock);
2782 next_bitmap = true;
2783 goto next;
2784 }
2785
2786 bytes = minlen;
2787 ret2 = search_bitmap(ctl, entry, &start, &bytes);
2788 if (ret2 || start >= end) {
2789 spin_unlock(&ctl->tree_lock);
2790 next_bitmap = true;
2791 goto next;
2792 }
2793
2794 bytes = min(bytes, end - start);
2795 if (bytes < minlen) {
2796 spin_unlock(&ctl->tree_lock);
2797 goto next;
2798 }
2799
2800 bitmap_clear_bits(ctl, entry, start, bytes);
2801 if (entry->bytes == 0)
2802 free_bitmap(ctl, entry);
2803
2804 spin_unlock(&ctl->tree_lock);
2805
2806 ret = do_trimming(block_group, total_trimmed, start, bytes,
2807 start, bytes);
2808 if (ret)
2809 break;
2810next:
2811 if (next_bitmap) {
2812 offset += BITS_PER_BITMAP * ctl->unit;
2813 } else {
2814 start += bytes;
2815 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
2816 offset += BITS_PER_BITMAP * ctl->unit;
2817 }
2818
2819 if (fatal_signal_pending(current)) {
2820 ret = -ERESTARTSYS;
2821 break;
2822 }
2823
2824 cond_resched();
2825 }
2826
2827 return ret;
2828}
2829
2830int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
2831 u64 *trimmed, u64 start, u64 end, u64 minlen)
2832{
2833 int ret;
2834
2835 *trimmed = 0;
2836
2837 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
2838 if (ret)
2839 return ret;
2840
2841 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
2842
2843 return ret;
2844}
2845
2846/*
2847 * Find the left-most item in the cache tree, and then return the
2848 * smallest inode number in the item.
2849 *
2850 * Note: the returned inode number may not be the smallest one in
2851 * the tree, if the left-most item is a bitmap.
2852 */
2853u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
2854{
2855 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
2856 struct btrfs_free_space *entry = NULL;
2857 u64 ino = 0;
2858
2859 spin_lock(&ctl->tree_lock);
2860
2861 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
2862 goto out;
2863
2864 entry = rb_entry(rb_first(&ctl->free_space_offset),
2865 struct btrfs_free_space, offset_index);
2866
2867 if (!entry->bitmap) {
2868 ino = entry->offset;
2869
2870 unlink_free_space(ctl, entry);
2871 entry->offset++;
2872 entry->bytes--;
2873 if (!entry->bytes)
2874 kmem_cache_free(btrfs_free_space_cachep, entry);
2875 else
2876 link_free_space(ctl, entry);
2877 } else {
2878 u64 offset = 0;
2879 u64 count = 1;
2880 int ret;
2881
2882 ret = search_bitmap(ctl, entry, &offset, &count);
2883 /* Logic error; Should be empty if it can't find anything */
2884 ASSERT(!ret);
2885
2886 ino = offset;
2887 bitmap_clear_bits(ctl, entry, offset, 1);
2888 if (entry->bytes == 0)
2889 free_bitmap(ctl, entry);
2890 }
2891out:
2892 spin_unlock(&ctl->tree_lock);
2893
2894 return ino;
2895}
2896
2897struct inode *lookup_free_ino_inode(struct btrfs_root *root,
2898 struct btrfs_path *path)
2899{
2900 struct inode *inode = NULL;
2901
2902 spin_lock(&root->cache_lock);
2903 if (root->cache_inode)
2904 inode = igrab(root->cache_inode);
2905 spin_unlock(&root->cache_lock);
2906 if (inode)
2907 return inode;
2908
2909 inode = __lookup_free_space_inode(root, path, 0);
2910 if (IS_ERR(inode))
2911 return inode;
2912
2913 spin_lock(&root->cache_lock);
2914 if (!btrfs_fs_closing(root->fs_info))
2915 root->cache_inode = igrab(inode);
2916 spin_unlock(&root->cache_lock);
2917
2918 return inode;
2919}
2920
2921int create_free_ino_inode(struct btrfs_root *root,
2922 struct btrfs_trans_handle *trans,
2923 struct btrfs_path *path)
2924{
2925 return __create_free_space_inode(root, trans, path,
2926 BTRFS_FREE_INO_OBJECTID, 0);
2927}
2928
2929int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2930{
2931 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
2932 struct btrfs_path *path;
2933 struct inode *inode;
2934 int ret = 0;
2935 u64 root_gen = btrfs_root_generation(&root->root_item);
2936
2937 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
2938 return 0;
2939
2940 /*
2941 * If we're unmounting then just return, since this does a search on the
2942 * normal root and not the commit root and we could deadlock.
2943 */
2944 if (btrfs_fs_closing(fs_info))
2945 return 0;
2946
2947 path = btrfs_alloc_path();
2948 if (!path)
2949 return 0;
2950
2951 inode = lookup_free_ino_inode(root, path);
2952 if (IS_ERR(inode))
2953 goto out;
2954
2955 if (root_gen != BTRFS_I(inode)->generation)
2956 goto out_put;
2957
2958 ret = __load_free_space_cache(root, inode, ctl, path, 0);
2959
2960 if (ret < 0)
2961 btrfs_err(fs_info,
2962 "failed to load free ino cache for root %llu",
2963 root->root_key.objectid);
2964out_put:
2965 iput(inode);
2966out:
2967 btrfs_free_path(path);
2968 return ret;
2969}
2970
2971int btrfs_write_out_ino_cache(struct btrfs_root *root,
2972 struct btrfs_trans_handle *trans,
2973 struct btrfs_path *path,
2974 struct inode *inode)
2975{
2976 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
2977 int ret;
2978
2979 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
2980 return 0;
2981
2982 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0);
2983 if (ret) {
2984 btrfs_delalloc_release_metadata(inode, inode->i_size);
2985#ifdef DEBUG
2986 btrfs_err(root->fs_info,
2987 "failed to write free ino cache for root %llu",
2988 root->root_key.objectid);
2989#endif
2990 }
2991
2992 return ret;
2993}
2994
2995#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
2996/*
2997 * Use this if you need to make a bitmap or extent entry specifically, it
2998 * doesn't do any of the merging that add_free_space does, this acts a lot like
2999 * how the free space cache loading stuff works, so you can get really weird
3000 * configurations.
3001 */
3002int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3003 u64 offset, u64 bytes, bool bitmap)
3004{
3005 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3006 struct btrfs_free_space *info = NULL, *bitmap_info;
3007 void *map = NULL;
3008 u64 bytes_added;
3009 int ret;
3010
3011again:
3012 if (!info) {
3013 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3014 if (!info)
3015 return -ENOMEM;
3016 }
3017
3018 if (!bitmap) {
3019 spin_lock(&ctl->tree_lock);
3020 info->offset = offset;
3021 info->bytes = bytes;
3022 ret = link_free_space(ctl, info);
3023 spin_unlock(&ctl->tree_lock);
3024 if (ret)
3025 kmem_cache_free(btrfs_free_space_cachep, info);
3026 return ret;
3027 }
3028
3029 if (!map) {
3030 map = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
3031 if (!map) {
3032 kmem_cache_free(btrfs_free_space_cachep, info);
3033 return -ENOMEM;
3034 }
3035 }
3036
3037 spin_lock(&ctl->tree_lock);
3038 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3039 1, 0);
3040 if (!bitmap_info) {
3041 info->bitmap = map;
3042 map = NULL;
3043 add_new_bitmap(ctl, info, offset);
3044 bitmap_info = info;
3045 }
3046
3047 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3048 bytes -= bytes_added;
3049 offset += bytes_added;
3050 spin_unlock(&ctl->tree_lock);
3051
3052 if (bytes)
3053 goto again;
3054
3055 if (map)
3056 kfree(map);
3057 return 0;
3058}
3059
3060/*
3061 * Checks to see if the given range is in the free space cache. This is really
3062 * just used to check the absence of space, so if there is free space in the
3063 * range at all we will return 1.
3064 */
3065int test_check_exists(struct btrfs_block_group_cache *cache,
3066 u64 offset, u64 bytes)
3067{
3068 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3069 struct btrfs_free_space *info;
3070 int ret = 0;
3071
3072 spin_lock(&ctl->tree_lock);
3073 info = tree_search_offset(ctl, offset, 0, 0);
3074 if (!info) {
3075 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3076 1, 0);
3077 if (!info)
3078 goto out;
3079 }
3080
3081have_info:
3082 if (info->bitmap) {
3083 u64 bit_off, bit_bytes;
3084 struct rb_node *n;
3085 struct btrfs_free_space *tmp;
3086
3087 bit_off = offset;
3088 bit_bytes = ctl->unit;
3089 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes);
3090 if (!ret) {
3091 if (bit_off == offset) {
3092 ret = 1;
3093 goto out;
3094 } else if (bit_off > offset &&
3095 offset + bytes > bit_off) {
3096 ret = 1;
3097 goto out;
3098 }
3099 }
3100
3101 n = rb_prev(&info->offset_index);
3102 while (n) {
3103 tmp = rb_entry(n, struct btrfs_free_space,
3104 offset_index);
3105 if (tmp->offset + tmp->bytes < offset)
3106 break;
3107 if (offset + bytes < tmp->offset) {
3108 n = rb_prev(&info->offset_index);
3109 continue;
3110 }
3111 info = tmp;
3112 goto have_info;
3113 }
3114
3115 n = rb_next(&info->offset_index);
3116 while (n) {
3117 tmp = rb_entry(n, struct btrfs_free_space,
3118 offset_index);
3119 if (offset + bytes < tmp->offset)
3120 break;
3121 if (tmp->offset + tmp->bytes < offset) {
3122 n = rb_next(&info->offset_index);
3123 continue;
3124 }
3125 info = tmp;
3126 goto have_info;
3127 }
3128
3129 goto out;
3130 }
3131
3132 if (info->offset == offset) {
3133 ret = 1;
3134 goto out;
3135 }
3136
3137 if (offset > info->offset && offset < info->offset + info->bytes)
3138 ret = 1;
3139out:
3140 spin_unlock(&ctl->tree_lock);
3141 return ret;
3142}
3143#endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */