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fanotify: merge duplicate events on parent and child
[linux/fpc-iii.git] / fs / btrfs / free-space-cache.c
blob0598fd3c6e3f1c97848b4b56308c356fb8002beb
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2008 Red Hat. All rights reserved.
4 */
5
6 #include <linux/pagemap.h>
7 #include <linux/sched.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
10 #include <linux/math64.h>
11 #include <linux/ratelimit.h>
12 #include <linux/error-injection.h>
13 #include <linux/sched/mm.h>
14 #include "ctree.h"
15 #include "free-space-cache.h"
16 #include "transaction.h"
17 #include "disk-io.h"
18 #include "extent_io.h"
19 #include "inode-map.h"
20 #include "volumes.h"
21 #include "space-info.h"
22 #include "delalloc-space.h"
23 #include "block-group.h"
24 #include "discard.h"
25
26 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
27 #define MAX_CACHE_BYTES_PER_GIG SZ_64K
28 #define FORCE_EXTENT_THRESHOLD SZ_1M
29
30 struct btrfs_trim_range {
31 u64 start;
32 u64 bytes;
33 struct list_head list;
34 };
35
36 static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl,
37 struct btrfs_free_space *bitmap_info);
38 static int link_free_space(struct btrfs_free_space_ctl *ctl,
39 struct btrfs_free_space *info);
40 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
41 struct btrfs_free_space *info);
42 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
43 struct btrfs_trans_handle *trans,
44 struct btrfs_io_ctl *io_ctl,
45 struct btrfs_path *path);
46
47 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
48 struct btrfs_path *path,
49 u64 offset)
50 {
51 struct btrfs_fs_info *fs_info = root->fs_info;
52 struct btrfs_key key;
53 struct btrfs_key location;
54 struct btrfs_disk_key disk_key;
55 struct btrfs_free_space_header *header;
56 struct extent_buffer *leaf;
57 struct inode *inode = NULL;
58 unsigned nofs_flag;
59 int ret;
60
61 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
62 key.offset = offset;
63 key.type = 0;
64
65 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
66 if (ret < 0)
67 return ERR_PTR(ret);
68 if (ret > 0) {
69 btrfs_release_path(path);
70 return ERR_PTR(-ENOENT);
71 }
72
73 leaf = path->nodes[0];
74 header = btrfs_item_ptr(leaf, path->slots[0],
75 struct btrfs_free_space_header);
76 btrfs_free_space_key(leaf, header, &disk_key);
77 btrfs_disk_key_to_cpu(&location, &disk_key);
78 btrfs_release_path(path);
79
80 /*
81 * We are often under a trans handle at this point, so we need to make
82 * sure NOFS is set to keep us from deadlocking.
83 */
84 nofs_flag = memalloc_nofs_save();
85 inode = btrfs_iget_path(fs_info->sb, &location, root, path);
86 btrfs_release_path(path);
87 memalloc_nofs_restore(nofs_flag);
88 if (IS_ERR(inode))
89 return inode;
90
91 mapping_set_gfp_mask(inode->i_mapping,
92 mapping_gfp_constraint(inode->i_mapping,
93 ~(__GFP_FS | __GFP_HIGHMEM)));
94
95 return inode;
96 }
97
98 struct inode *lookup_free_space_inode(struct btrfs_block_group *block_group,
99 struct btrfs_path *path)
100 {
101 struct btrfs_fs_info *fs_info = block_group->fs_info;
102 struct inode *inode = NULL;
103 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
104
105 spin_lock(&block_group->lock);
106 if (block_group->inode)
107 inode = igrab(block_group->inode);
108 spin_unlock(&block_group->lock);
109 if (inode)
110 return inode;
111
112 inode = __lookup_free_space_inode(fs_info->tree_root, path,
113 block_group->start);
114 if (IS_ERR(inode))
115 return inode;
116
117 spin_lock(&block_group->lock);
118 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
119 btrfs_info(fs_info, "Old style space inode found, converting.");
120 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
121 BTRFS_INODE_NODATACOW;
122 block_group->disk_cache_state = BTRFS_DC_CLEAR;
123 }
124
125 if (!block_group->iref) {
126 block_group->inode = igrab(inode);
127 block_group->iref = 1;
128 }
129 spin_unlock(&block_group->lock);
130
131 return inode;
132 }
133
134 static int __create_free_space_inode(struct btrfs_root *root,
135 struct btrfs_trans_handle *trans,
136 struct btrfs_path *path,
137 u64 ino, u64 offset)
138 {
139 struct btrfs_key key;
140 struct btrfs_disk_key disk_key;
141 struct btrfs_free_space_header *header;
142 struct btrfs_inode_item *inode_item;
143 struct extent_buffer *leaf;
144 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
145 int ret;
146
147 ret = btrfs_insert_empty_inode(trans, root, path, ino);
148 if (ret)
149 return ret;
150
151 /* We inline crc's for the free disk space cache */
152 if (ino != BTRFS_FREE_INO_OBJECTID)
153 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
154
155 leaf = path->nodes[0];
156 inode_item = btrfs_item_ptr(leaf, path->slots[0],
157 struct btrfs_inode_item);
158 btrfs_item_key(leaf, &disk_key, path->slots[0]);
159 memzero_extent_buffer(leaf, (unsigned long)inode_item,
160 sizeof(*inode_item));
161 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
162 btrfs_set_inode_size(leaf, inode_item, 0);
163 btrfs_set_inode_nbytes(leaf, inode_item, 0);
164 btrfs_set_inode_uid(leaf, inode_item, 0);
165 btrfs_set_inode_gid(leaf, inode_item, 0);
166 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
167 btrfs_set_inode_flags(leaf, inode_item, flags);
168 btrfs_set_inode_nlink(leaf, inode_item, 1);
169 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
170 btrfs_set_inode_block_group(leaf, inode_item, offset);
171 btrfs_mark_buffer_dirty(leaf);
172 btrfs_release_path(path);
173
174 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
175 key.offset = offset;
176 key.type = 0;
177 ret = btrfs_insert_empty_item(trans, root, path, &key,
178 sizeof(struct btrfs_free_space_header));
179 if (ret < 0) {
180 btrfs_release_path(path);
181 return ret;
182 }
183
184 leaf = path->nodes[0];
185 header = btrfs_item_ptr(leaf, path->slots[0],
186 struct btrfs_free_space_header);
187 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
188 btrfs_set_free_space_key(leaf, header, &disk_key);
189 btrfs_mark_buffer_dirty(leaf);
190 btrfs_release_path(path);
191
192 return 0;
193 }
194
195 int create_free_space_inode(struct btrfs_trans_handle *trans,
196 struct btrfs_block_group *block_group,
197 struct btrfs_path *path)
198 {
199 int ret;
200 u64 ino;
201
202 ret = btrfs_find_free_objectid(trans->fs_info->tree_root, &ino);
203 if (ret < 0)
204 return ret;
205
206 return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
207 ino, block_group->start);
208 }
209
210 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
211 struct btrfs_block_rsv *rsv)
212 {
213 u64 needed_bytes;
214 int ret;
215
216 /* 1 for slack space, 1 for updating the inode */
217 needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
218 btrfs_calc_metadata_size(fs_info, 1);
219
220 spin_lock(&rsv->lock);
221 if (rsv->reserved < needed_bytes)
222 ret = -ENOSPC;
223 else
224 ret = 0;
225 spin_unlock(&rsv->lock);
226 return ret;
227 }
228
229 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
230 struct btrfs_block_group *block_group,
231 struct inode *inode)
232 {
233 struct btrfs_root *root = BTRFS_I(inode)->root;
234 int ret = 0;
235 bool locked = false;
236
237 if (block_group) {
238 struct btrfs_path *path = btrfs_alloc_path();
239
240 if (!path) {
241 ret = -ENOMEM;
242 goto fail;
243 }
244 locked = true;
245 mutex_lock(&trans->transaction->cache_write_mutex);
246 if (!list_empty(&block_group->io_list)) {
247 list_del_init(&block_group->io_list);
248
249 btrfs_wait_cache_io(trans, block_group, path);
250 btrfs_put_block_group(block_group);
251 }
252
253 /*
254 * now that we've truncated the cache away, its no longer
255 * setup or written
256 */
257 spin_lock(&block_group->lock);
258 block_group->disk_cache_state = BTRFS_DC_CLEAR;
259 spin_unlock(&block_group->lock);
260 btrfs_free_path(path);
261 }
262
263 btrfs_i_size_write(BTRFS_I(inode), 0);
264 truncate_pagecache(inode, 0);
265
266 /*
267 * We skip the throttling logic for free space cache inodes, so we don't
268 * need to check for -EAGAIN.
269 */
270 ret = btrfs_truncate_inode_items(trans, root, inode,
271 0, BTRFS_EXTENT_DATA_KEY);
272 if (ret)
273 goto fail;
274
275 ret = btrfs_update_inode(trans, root, inode);
276
277 fail:
278 if (locked)
279 mutex_unlock(&trans->transaction->cache_write_mutex);
280 if (ret)
281 btrfs_abort_transaction(trans, ret);
282
283 return ret;
284 }
285
286 static void readahead_cache(struct inode *inode)
287 {
288 struct file_ra_state *ra;
289 unsigned long last_index;
290
291 ra = kzalloc(sizeof(*ra), GFP_NOFS);
292 if (!ra)
293 return;
294
295 file_ra_state_init(ra, inode->i_mapping);
296 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
297
298 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
299
300 kfree(ra);
301 }
302
303 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
304 int write)
305 {
306 int num_pages;
307 int check_crcs = 0;
308
309 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
310
311 if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
312 check_crcs = 1;
313
314 /* Make sure we can fit our crcs and generation into the first page */
315 if (write && check_crcs &&
316 (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
317 return -ENOSPC;
318
319 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
320
321 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
322 if (!io_ctl->pages)
323 return -ENOMEM;
324
325 io_ctl->num_pages = num_pages;
326 io_ctl->fs_info = btrfs_sb(inode->i_sb);
327 io_ctl->check_crcs = check_crcs;
328 io_ctl->inode = inode;
329
330 return 0;
331 }
332 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
333
334 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
335 {
336 kfree(io_ctl->pages);
337 io_ctl->pages = NULL;
338 }
339
340 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
341 {
342 if (io_ctl->cur) {
343 io_ctl->cur = NULL;
344 io_ctl->orig = NULL;
345 }
346 }
347
348 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
349 {
350 ASSERT(io_ctl->index < io_ctl->num_pages);
351 io_ctl->page = io_ctl->pages[io_ctl->index++];
352 io_ctl->cur = page_address(io_ctl->page);
353 io_ctl->orig = io_ctl->cur;
354 io_ctl->size = PAGE_SIZE;
355 if (clear)
356 clear_page(io_ctl->cur);
357 }
358
359 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
360 {
361 int i;
362
363 io_ctl_unmap_page(io_ctl);
364
365 for (i = 0; i < io_ctl->num_pages; i++) {
366 if (io_ctl->pages[i]) {
367 ClearPageChecked(io_ctl->pages[i]);
368 unlock_page(io_ctl->pages[i]);
369 put_page(io_ctl->pages[i]);
370 }
371 }
372 }
373
374 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
375 int uptodate)
376 {
377 struct page *page;
378 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
379 int i;
380
381 for (i = 0; i < io_ctl->num_pages; i++) {
382 page = find_or_create_page(inode->i_mapping, i, mask);
383 if (!page) {
384 io_ctl_drop_pages(io_ctl);
385 return -ENOMEM;
386 }
387 io_ctl->pages[i] = page;
388 if (uptodate && !PageUptodate(page)) {
389 btrfs_readpage(NULL, page);
390 lock_page(page);
391 if (page->mapping != inode->i_mapping) {
392 btrfs_err(BTRFS_I(inode)->root->fs_info,
393 "free space cache page truncated");
394 io_ctl_drop_pages(io_ctl);
395 return -EIO;
396 }
397 if (!PageUptodate(page)) {
398 btrfs_err(BTRFS_I(inode)->root->fs_info,
399 "error reading free space cache");
400 io_ctl_drop_pages(io_ctl);
401 return -EIO;
402 }
403 }
404 }
405
406 for (i = 0; i < io_ctl->num_pages; i++) {
407 clear_page_dirty_for_io(io_ctl->pages[i]);
408 set_page_extent_mapped(io_ctl->pages[i]);
409 }
410
411 return 0;
412 }
413
414 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
415 {
416 __le64 *val;
417
418 io_ctl_map_page(io_ctl, 1);
419
420 /*
421 * Skip the csum areas. If we don't check crcs then we just have a
422 * 64bit chunk at the front of the first page.
423 */
424 if (io_ctl->check_crcs) {
425 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
426 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
427 } else {
428 io_ctl->cur += sizeof(u64);
429 io_ctl->size -= sizeof(u64) * 2;
430 }
431
432 val = io_ctl->cur;
433 *val = cpu_to_le64(generation);
434 io_ctl->cur += sizeof(u64);
435 }
436
437 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
438 {
439 __le64 *gen;
440
441 /*
442 * Skip the crc area. If we don't check crcs then we just have a 64bit
443 * chunk at the front of the first page.
444 */
445 if (io_ctl->check_crcs) {
446 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
447 io_ctl->size -= sizeof(u64) +
448 (sizeof(u32) * io_ctl->num_pages);
449 } else {
450 io_ctl->cur += sizeof(u64);
451 io_ctl->size -= sizeof(u64) * 2;
452 }
453
454 gen = io_ctl->cur;
455 if (le64_to_cpu(*gen) != generation) {
456 btrfs_err_rl(io_ctl->fs_info,
457 "space cache generation (%llu) does not match inode (%llu)",
458 *gen, generation);
459 io_ctl_unmap_page(io_ctl);
460 return -EIO;
461 }
462 io_ctl->cur += sizeof(u64);
463 return 0;
464 }
465
466 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
467 {
468 u32 *tmp;
469 u32 crc = ~(u32)0;
470 unsigned offset = 0;
471
472 if (!io_ctl->check_crcs) {
473 io_ctl_unmap_page(io_ctl);
474 return;
475 }
476
477 if (index == 0)
478 offset = sizeof(u32) * io_ctl->num_pages;
479
480 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
481 btrfs_crc32c_final(crc, (u8 *)&crc);
482 io_ctl_unmap_page(io_ctl);
483 tmp = page_address(io_ctl->pages[0]);
484 tmp += index;
485 *tmp = crc;
486 }
487
488 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
489 {
490 u32 *tmp, val;
491 u32 crc = ~(u32)0;
492 unsigned offset = 0;
493
494 if (!io_ctl->check_crcs) {
495 io_ctl_map_page(io_ctl, 0);
496 return 0;
497 }
498
499 if (index == 0)
500 offset = sizeof(u32) * io_ctl->num_pages;
501
502 tmp = page_address(io_ctl->pages[0]);
503 tmp += index;
504 val = *tmp;
505
506 io_ctl_map_page(io_ctl, 0);
507 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
508 btrfs_crc32c_final(crc, (u8 *)&crc);
509 if (val != crc) {
510 btrfs_err_rl(io_ctl->fs_info,
511 "csum mismatch on free space cache");
512 io_ctl_unmap_page(io_ctl);
513 return -EIO;
514 }
515
516 return 0;
517 }
518
519 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
520 void *bitmap)
521 {
522 struct btrfs_free_space_entry *entry;
523
524 if (!io_ctl->cur)
525 return -ENOSPC;
526
527 entry = io_ctl->cur;
528 entry->offset = cpu_to_le64(offset);
529 entry->bytes = cpu_to_le64(bytes);
530 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
531 BTRFS_FREE_SPACE_EXTENT;
532 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
533 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
534
535 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
536 return 0;
537
538 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
539
540 /* No more pages to map */
541 if (io_ctl->index >= io_ctl->num_pages)
542 return 0;
543
544 /* map the next page */
545 io_ctl_map_page(io_ctl, 1);
546 return 0;
547 }
548
549 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
550 {
551 if (!io_ctl->cur)
552 return -ENOSPC;
553
554 /*
555 * If we aren't at the start of the current page, unmap this one and
556 * map the next one if there is any left.
557 */
558 if (io_ctl->cur != io_ctl->orig) {
559 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
560 if (io_ctl->index >= io_ctl->num_pages)
561 return -ENOSPC;
562 io_ctl_map_page(io_ctl, 0);
563 }
564
565 copy_page(io_ctl->cur, bitmap);
566 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
567 if (io_ctl->index < io_ctl->num_pages)
568 io_ctl_map_page(io_ctl, 0);
569 return 0;
570 }
571
572 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
573 {
574 /*
575 * If we're not on the boundary we know we've modified the page and we
576 * need to crc the page.
577 */
578 if (io_ctl->cur != io_ctl->orig)
579 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
580 else
581 io_ctl_unmap_page(io_ctl);
582
583 while (io_ctl->index < io_ctl->num_pages) {
584 io_ctl_map_page(io_ctl, 1);
585 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
586 }
587 }
588
589 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
590 struct btrfs_free_space *entry, u8 *type)
591 {
592 struct btrfs_free_space_entry *e;
593 int ret;
594
595 if (!io_ctl->cur) {
596 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
597 if (ret)
598 return ret;
599 }
600
601 e = io_ctl->cur;
602 entry->offset = le64_to_cpu(e->offset);
603 entry->bytes = le64_to_cpu(e->bytes);
604 *type = e->type;
605 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
606 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
607
608 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
609 return 0;
610
611 io_ctl_unmap_page(io_ctl);
612
613 return 0;
614 }
615
616 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
617 struct btrfs_free_space *entry)
618 {
619 int ret;
620
621 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
622 if (ret)
623 return ret;
624
625 copy_page(entry->bitmap, io_ctl->cur);
626 io_ctl_unmap_page(io_ctl);
627
628 return 0;
629 }
630
631 /*
632 * Since we attach pinned extents after the fact we can have contiguous sections
633 * of free space that are split up in entries. This poses a problem with the
634 * tree logging stuff since it could have allocated across what appears to be 2
635 * entries since we would have merged the entries when adding the pinned extents
636 * back to the free space cache. So run through the space cache that we just
637 * loaded and merge contiguous entries. This will make the log replay stuff not
638 * blow up and it will make for nicer allocator behavior.
639 */
640 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
641 {
642 struct btrfs_free_space *e, *prev = NULL;
643 struct rb_node *n;
644
645 again:
646 spin_lock(&ctl->tree_lock);
647 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
648 e = rb_entry(n, struct btrfs_free_space, offset_index);
649 if (!prev)
650 goto next;
651 if (e->bitmap || prev->bitmap)
652 goto next;
653 if (prev->offset + prev->bytes == e->offset) {
654 unlink_free_space(ctl, prev);
655 unlink_free_space(ctl, e);
656 prev->bytes += e->bytes;
657 kmem_cache_free(btrfs_free_space_cachep, e);
658 link_free_space(ctl, prev);
659 prev = NULL;
660 spin_unlock(&ctl->tree_lock);
661 goto again;
662 }
663 next:
664 prev = e;
665 }
666 spin_unlock(&ctl->tree_lock);
667 }
668
669 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
670 struct btrfs_free_space_ctl *ctl,
671 struct btrfs_path *path, u64 offset)
672 {
673 struct btrfs_fs_info *fs_info = root->fs_info;
674 struct btrfs_free_space_header *header;
675 struct extent_buffer *leaf;
676 struct btrfs_io_ctl io_ctl;
677 struct btrfs_key key;
678 struct btrfs_free_space *e, *n;
679 LIST_HEAD(bitmaps);
680 u64 num_entries;
681 u64 num_bitmaps;
682 u64 generation;
683 u8 type;
684 int ret = 0;
685
686 /* Nothing in the space cache, goodbye */
687 if (!i_size_read(inode))
688 return 0;
689
690 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
691 key.offset = offset;
692 key.type = 0;
693
694 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
695 if (ret < 0)
696 return 0;
697 else if (ret > 0) {
698 btrfs_release_path(path);
699 return 0;
700 }
701
702 ret = -1;
703
704 leaf = path->nodes[0];
705 header = btrfs_item_ptr(leaf, path->slots[0],
706 struct btrfs_free_space_header);
707 num_entries = btrfs_free_space_entries(leaf, header);
708 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
709 generation = btrfs_free_space_generation(leaf, header);
710 btrfs_release_path(path);
711
712 if (!BTRFS_I(inode)->generation) {
713 btrfs_info(fs_info,
714 "the free space cache file (%llu) is invalid, skip it",
715 offset);
716 return 0;
717 }
718
719 if (BTRFS_I(inode)->generation != generation) {
720 btrfs_err(fs_info,
721 "free space inode generation (%llu) did not match free space cache generation (%llu)",
722 BTRFS_I(inode)->generation, generation);
723 return 0;
724 }
725
726 if (!num_entries)
727 return 0;
728
729 ret = io_ctl_init(&io_ctl, inode, 0);
730 if (ret)
731 return ret;
732
733 readahead_cache(inode);
734
735 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
736 if (ret)
737 goto out;
738
739 ret = io_ctl_check_crc(&io_ctl, 0);
740 if (ret)
741 goto free_cache;
742
743 ret = io_ctl_check_generation(&io_ctl, generation);
744 if (ret)
745 goto free_cache;
746
747 while (num_entries) {
748 e = kmem_cache_zalloc(btrfs_free_space_cachep,
749 GFP_NOFS);
750 if (!e)
751 goto free_cache;
752
753 ret = io_ctl_read_entry(&io_ctl, e, &type);
754 if (ret) {
755 kmem_cache_free(btrfs_free_space_cachep, e);
756 goto free_cache;
757 }
758
759 /*
760 * Sync discard ensures that the free space cache is always
761 * trimmed. So when reading this in, the state should reflect
762 * that. We also do this for async as a stop gap for lack of
763 * persistence.
764 */
765 if (btrfs_test_opt(fs_info, DISCARD_SYNC) ||
766 btrfs_test_opt(fs_info, DISCARD_ASYNC))
767 e->trim_state = BTRFS_TRIM_STATE_TRIMMED;
768
769 if (!e->bytes) {
770 kmem_cache_free(btrfs_free_space_cachep, e);
771 goto free_cache;
772 }
773
774 if (type == BTRFS_FREE_SPACE_EXTENT) {
775 spin_lock(&ctl->tree_lock);
776 ret = link_free_space(ctl, e);
777 spin_unlock(&ctl->tree_lock);
778 if (ret) {
779 btrfs_err(fs_info,
780 "Duplicate entries in free space cache, dumping");
781 kmem_cache_free(btrfs_free_space_cachep, e);
782 goto free_cache;
783 }
784 } else {
785 ASSERT(num_bitmaps);
786 num_bitmaps--;
787 e->bitmap = kmem_cache_zalloc(
788 btrfs_free_space_bitmap_cachep, GFP_NOFS);
789 if (!e->bitmap) {
790 kmem_cache_free(
791 btrfs_free_space_cachep, e);
792 goto free_cache;
793 }
794 spin_lock(&ctl->tree_lock);
795 ret = link_free_space(ctl, e);
796 ctl->total_bitmaps++;
797 ctl->op->recalc_thresholds(ctl);
798 spin_unlock(&ctl->tree_lock);
799 if (ret) {
800 btrfs_err(fs_info,
801 "Duplicate entries in free space cache, dumping");
802 kmem_cache_free(btrfs_free_space_cachep, e);
803 goto free_cache;
804 }
805 list_add_tail(&e->list, &bitmaps);
806 }
807
808 num_entries--;
809 }
810
811 io_ctl_unmap_page(&io_ctl);
812
813 /*
814 * We add the bitmaps at the end of the entries in order that
815 * the bitmap entries are added to the cache.
816 */
817 list_for_each_entry_safe(e, n, &bitmaps, list) {
818 list_del_init(&e->list);
819 ret = io_ctl_read_bitmap(&io_ctl, e);
820 if (ret)
821 goto free_cache;
822 e->bitmap_extents = count_bitmap_extents(ctl, e);
823 if (!btrfs_free_space_trimmed(e)) {
824 ctl->discardable_extents[BTRFS_STAT_CURR] +=
825 e->bitmap_extents;
826 ctl->discardable_bytes[BTRFS_STAT_CURR] += e->bytes;
827 }
828 }
829
830 io_ctl_drop_pages(&io_ctl);
831 merge_space_tree(ctl);
832 ret = 1;
833 out:
834 btrfs_discard_update_discardable(ctl->private, ctl);
835 io_ctl_free(&io_ctl);
836 return ret;
837 free_cache:
838 io_ctl_drop_pages(&io_ctl);
839 __btrfs_remove_free_space_cache(ctl);
840 goto out;
841 }
842
843 int load_free_space_cache(struct btrfs_block_group *block_group)
844 {
845 struct btrfs_fs_info *fs_info = block_group->fs_info;
846 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
847 struct inode *inode;
848 struct btrfs_path *path;
849 int ret = 0;
850 bool matched;
851 u64 used = block_group->used;
852
853 /*
854 * If this block group has been marked to be cleared for one reason or
855 * another then we can't trust the on disk cache, so just return.
856 */
857 spin_lock(&block_group->lock);
858 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
859 spin_unlock(&block_group->lock);
860 return 0;
861 }
862 spin_unlock(&block_group->lock);
863
864 path = btrfs_alloc_path();
865 if (!path)
866 return 0;
867 path->search_commit_root = 1;
868 path->skip_locking = 1;
869
870 /*
871 * We must pass a path with search_commit_root set to btrfs_iget in
872 * order to avoid a deadlock when allocating extents for the tree root.
873 *
874 * When we are COWing an extent buffer from the tree root, when looking
875 * for a free extent, at extent-tree.c:find_free_extent(), we can find
876 * block group without its free space cache loaded. When we find one
877 * we must load its space cache which requires reading its free space
878 * cache's inode item from the root tree. If this inode item is located
879 * in the same leaf that we started COWing before, then we end up in
880 * deadlock on the extent buffer (trying to read lock it when we
881 * previously write locked it).
882 *
883 * It's safe to read the inode item using the commit root because
884 * block groups, once loaded, stay in memory forever (until they are
885 * removed) as well as their space caches once loaded. New block groups
886 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
887 * we will never try to read their inode item while the fs is mounted.
888 */
889 inode = lookup_free_space_inode(block_group, path);
890 if (IS_ERR(inode)) {
891 btrfs_free_path(path);
892 return 0;
893 }
894
895 /* We may have converted the inode and made the cache invalid. */
896 spin_lock(&block_group->lock);
897 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
898 spin_unlock(&block_group->lock);
899 btrfs_free_path(path);
900 goto out;
901 }
902 spin_unlock(&block_group->lock);
903
904 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
905 path, block_group->start);
906 btrfs_free_path(path);
907 if (ret <= 0)
908 goto out;
909
910 spin_lock(&ctl->tree_lock);
911 matched = (ctl->free_space == (block_group->length - used -
912 block_group->bytes_super));
913 spin_unlock(&ctl->tree_lock);
914
915 if (!matched) {
916 __btrfs_remove_free_space_cache(ctl);
917 btrfs_warn(fs_info,
918 "block group %llu has wrong amount of free space",
919 block_group->start);
920 ret = -1;
921 }
922 out:
923 if (ret < 0) {
924 /* This cache is bogus, make sure it gets cleared */
925 spin_lock(&block_group->lock);
926 block_group->disk_cache_state = BTRFS_DC_CLEAR;
927 spin_unlock(&block_group->lock);
928 ret = 0;
929
930 btrfs_warn(fs_info,
931 "failed to load free space cache for block group %llu, rebuilding it now",
932 block_group->start);
933 }
934
935 iput(inode);
936 return ret;
937 }
938
939 static noinline_for_stack
940 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
941 struct btrfs_free_space_ctl *ctl,
942 struct btrfs_block_group *block_group,
943 int *entries, int *bitmaps,
944 struct list_head *bitmap_list)
945 {
946 int ret;
947 struct btrfs_free_cluster *cluster = NULL;
948 struct btrfs_free_cluster *cluster_locked = NULL;
949 struct rb_node *node = rb_first(&ctl->free_space_offset);
950 struct btrfs_trim_range *trim_entry;
951
952 /* Get the cluster for this block_group if it exists */
953 if (block_group && !list_empty(&block_group->cluster_list)) {
954 cluster = list_entry(block_group->cluster_list.next,
955 struct btrfs_free_cluster,
956 block_group_list);
957 }
958
959 if (!node && cluster) {
960 cluster_locked = cluster;
961 spin_lock(&cluster_locked->lock);
962 node = rb_first(&cluster->root);
963 cluster = NULL;
964 }
965
966 /* Write out the extent entries */
967 while (node) {
968 struct btrfs_free_space *e;
969
970 e = rb_entry(node, struct btrfs_free_space, offset_index);
971 *entries += 1;
972
973 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
974 e->bitmap);
975 if (ret)
976 goto fail;
977
978 if (e->bitmap) {
979 list_add_tail(&e->list, bitmap_list);
980 *bitmaps += 1;
981 }
982 node = rb_next(node);
983 if (!node && cluster) {
984 node = rb_first(&cluster->root);
985 cluster_locked = cluster;
986 spin_lock(&cluster_locked->lock);
987 cluster = NULL;
988 }
989 }
990 if (cluster_locked) {
991 spin_unlock(&cluster_locked->lock);
992 cluster_locked = NULL;
993 }
994
995 /*
996 * Make sure we don't miss any range that was removed from our rbtree
997 * because trimming is running. Otherwise after a umount+mount (or crash
998 * after committing the transaction) we would leak free space and get
999 * an inconsistent free space cache report from fsck.
1000 */
1001 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
1002 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
1003 trim_entry->bytes, NULL);
1004 if (ret)
1005 goto fail;
1006 *entries += 1;
1007 }
1008
1009 return 0;
1010 fail:
1011 if (cluster_locked)
1012 spin_unlock(&cluster_locked->lock);
1013 return -ENOSPC;
1014 }
1015
1016 static noinline_for_stack int
1017 update_cache_item(struct btrfs_trans_handle *trans,
1018 struct btrfs_root *root,
1019 struct inode *inode,
1020 struct btrfs_path *path, u64 offset,
1021 int entries, int bitmaps)
1022 {
1023 struct btrfs_key key;
1024 struct btrfs_free_space_header *header;
1025 struct extent_buffer *leaf;
1026 int ret;
1027
1028 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1029 key.offset = offset;
1030 key.type = 0;
1031
1032 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1033 if (ret < 0) {
1034 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1035 EXTENT_DELALLOC, 0, 0, NULL);
1036 goto fail;
1037 }
1038 leaf = path->nodes[0];
1039 if (ret > 0) {
1040 struct btrfs_key found_key;
1041 ASSERT(path->slots[0]);
1042 path->slots[0]--;
1043 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1044 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1045 found_key.offset != offset) {
1046 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1047 inode->i_size - 1, EXTENT_DELALLOC, 0,
1048 0, NULL);
1049 btrfs_release_path(path);
1050 goto fail;
1051 }
1052 }
1053
1054 BTRFS_I(inode)->generation = trans->transid;
1055 header = btrfs_item_ptr(leaf, path->slots[0],
1056 struct btrfs_free_space_header);
1057 btrfs_set_free_space_entries(leaf, header, entries);
1058 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1059 btrfs_set_free_space_generation(leaf, header, trans->transid);
1060 btrfs_mark_buffer_dirty(leaf);
1061 btrfs_release_path(path);
1062
1063 return 0;
1064
1065 fail:
1066 return -1;
1067 }
1068
1069 static noinline_for_stack int write_pinned_extent_entries(
1070 struct btrfs_block_group *block_group,
1071 struct btrfs_io_ctl *io_ctl,
1072 int *entries)
1073 {
1074 u64 start, extent_start, extent_end, len;
1075 struct extent_io_tree *unpin = NULL;
1076 int ret;
1077
1078 if (!block_group)
1079 return 0;
1080
1081 /*
1082 * We want to add any pinned extents to our free space cache
1083 * so we don't leak the space
1084 *
1085 * We shouldn't have switched the pinned extents yet so this is the
1086 * right one
1087 */
1088 unpin = block_group->fs_info->pinned_extents;
1089
1090 start = block_group->start;
1091
1092 while (start < block_group->start + block_group->length) {
1093 ret = find_first_extent_bit(unpin, start,
1094 &extent_start, &extent_end,
1095 EXTENT_DIRTY, NULL);
1096 if (ret)
1097 return 0;
1098
1099 /* This pinned extent is out of our range */
1100 if (extent_start >= block_group->start + block_group->length)
1101 return 0;
1102
1103 extent_start = max(extent_start, start);
1104 extent_end = min(block_group->start + block_group->length,
1105 extent_end + 1);
1106 len = extent_end - extent_start;
1107
1108 *entries += 1;
1109 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1110 if (ret)
1111 return -ENOSPC;
1112
1113 start = extent_end;
1114 }
1115
1116 return 0;
1117 }
1118
1119 static noinline_for_stack int
1120 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1121 {
1122 struct btrfs_free_space *entry, *next;
1123 int ret;
1124
1125 /* Write out the bitmaps */
1126 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1127 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1128 if (ret)
1129 return -ENOSPC;
1130 list_del_init(&entry->list);
1131 }
1132
1133 return 0;
1134 }
1135
1136 static int flush_dirty_cache(struct inode *inode)
1137 {
1138 int ret;
1139
1140 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1141 if (ret)
1142 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1143 EXTENT_DELALLOC, 0, 0, NULL);
1144
1145 return ret;
1146 }
1147
1148 static void noinline_for_stack
1149 cleanup_bitmap_list(struct list_head *bitmap_list)
1150 {
1151 struct btrfs_free_space *entry, *next;
1152
1153 list_for_each_entry_safe(entry, next, bitmap_list, list)
1154 list_del_init(&entry->list);
1155 }
1156
1157 static void noinline_for_stack
1158 cleanup_write_cache_enospc(struct inode *inode,
1159 struct btrfs_io_ctl *io_ctl,
1160 struct extent_state **cached_state)
1161 {
1162 io_ctl_drop_pages(io_ctl);
1163 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1164 i_size_read(inode) - 1, cached_state);
1165 }
1166
1167 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1168 struct btrfs_trans_handle *trans,
1169 struct btrfs_block_group *block_group,
1170 struct btrfs_io_ctl *io_ctl,
1171 struct btrfs_path *path, u64 offset)
1172 {
1173 int ret;
1174 struct inode *inode = io_ctl->inode;
1175
1176 if (!inode)
1177 return 0;
1178
1179 /* Flush the dirty pages in the cache file. */
1180 ret = flush_dirty_cache(inode);
1181 if (ret)
1182 goto out;
1183
1184 /* Update the cache item to tell everyone this cache file is valid. */
1185 ret = update_cache_item(trans, root, inode, path, offset,
1186 io_ctl->entries, io_ctl->bitmaps);
1187 out:
1188 io_ctl_free(io_ctl);
1189 if (ret) {
1190 invalidate_inode_pages2(inode->i_mapping);
1191 BTRFS_I(inode)->generation = 0;
1192 if (block_group) {
1193 #ifdef DEBUG
1194 btrfs_err(root->fs_info,
1195 "failed to write free space cache for block group %llu",
1196 block_group->start);
1197 #endif
1198 }
1199 }
1200 btrfs_update_inode(trans, root, inode);
1201
1202 if (block_group) {
1203 /* the dirty list is protected by the dirty_bgs_lock */
1204 spin_lock(&trans->transaction->dirty_bgs_lock);
1205
1206 /* the disk_cache_state is protected by the block group lock */
1207 spin_lock(&block_group->lock);
1208
1209 /*
1210 * only mark this as written if we didn't get put back on
1211 * the dirty list while waiting for IO. Otherwise our
1212 * cache state won't be right, and we won't get written again
1213 */
1214 if (!ret && list_empty(&block_group->dirty_list))
1215 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1216 else if (ret)
1217 block_group->disk_cache_state = BTRFS_DC_ERROR;
1218
1219 spin_unlock(&block_group->lock);
1220 spin_unlock(&trans->transaction->dirty_bgs_lock);
1221 io_ctl->inode = NULL;
1222 iput(inode);
1223 }
1224
1225 return ret;
1226
1227 }
1228
1229 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
1230 struct btrfs_trans_handle *trans,
1231 struct btrfs_io_ctl *io_ctl,
1232 struct btrfs_path *path)
1233 {
1234 return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
1235 }
1236
1237 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1238 struct btrfs_block_group *block_group,
1239 struct btrfs_path *path)
1240 {
1241 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1242 block_group, &block_group->io_ctl,
1243 path, block_group->start);
1244 }
1245
1246 /**
1247 * __btrfs_write_out_cache - write out cached info to an inode
1248 * @root - the root the inode belongs to
1249 * @ctl - the free space cache we are going to write out
1250 * @block_group - the block_group for this cache if it belongs to a block_group
1251 * @trans - the trans handle
1252 *
1253 * This function writes out a free space cache struct to disk for quick recovery
1254 * on mount. This will return 0 if it was successful in writing the cache out,
1255 * or an errno if it was not.
1256 */
1257 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1258 struct btrfs_free_space_ctl *ctl,
1259 struct btrfs_block_group *block_group,
1260 struct btrfs_io_ctl *io_ctl,
1261 struct btrfs_trans_handle *trans)
1262 {
1263 struct extent_state *cached_state = NULL;
1264 LIST_HEAD(bitmap_list);
1265 int entries = 0;
1266 int bitmaps = 0;
1267 int ret;
1268 int must_iput = 0;
1269
1270 if (!i_size_read(inode))
1271 return -EIO;
1272
1273 WARN_ON(io_ctl->pages);
1274 ret = io_ctl_init(io_ctl, inode, 1);
1275 if (ret)
1276 return ret;
1277
1278 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1279 down_write(&block_group->data_rwsem);
1280 spin_lock(&block_group->lock);
1281 if (block_group->delalloc_bytes) {
1282 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1283 spin_unlock(&block_group->lock);
1284 up_write(&block_group->data_rwsem);
1285 BTRFS_I(inode)->generation = 0;
1286 ret = 0;
1287 must_iput = 1;
1288 goto out;
1289 }
1290 spin_unlock(&block_group->lock);
1291 }
1292
1293 /* Lock all pages first so we can lock the extent safely. */
1294 ret = io_ctl_prepare_pages(io_ctl, inode, 0);
1295 if (ret)
1296 goto out_unlock;
1297
1298 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1299 &cached_state);
1300
1301 io_ctl_set_generation(io_ctl, trans->transid);
1302
1303 mutex_lock(&ctl->cache_writeout_mutex);
1304 /* Write out the extent entries in the free space cache */
1305 spin_lock(&ctl->tree_lock);
1306 ret = write_cache_extent_entries(io_ctl, ctl,
1307 block_group, &entries, &bitmaps,
1308 &bitmap_list);
1309 if (ret)
1310 goto out_nospc_locked;
1311
1312 /*
1313 * Some spaces that are freed in the current transaction are pinned,
1314 * they will be added into free space cache after the transaction is
1315 * committed, we shouldn't lose them.
1316 *
1317 * If this changes while we are working we'll get added back to
1318 * the dirty list and redo it. No locking needed
1319 */
1320 ret = write_pinned_extent_entries(block_group, io_ctl, &entries);
1321 if (ret)
1322 goto out_nospc_locked;
1323
1324 /*
1325 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1326 * locked while doing it because a concurrent trim can be manipulating
1327 * or freeing the bitmap.
1328 */
1329 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1330 spin_unlock(&ctl->tree_lock);
1331 mutex_unlock(&ctl->cache_writeout_mutex);
1332 if (ret)
1333 goto out_nospc;
1334
1335 /* Zero out the rest of the pages just to make sure */
1336 io_ctl_zero_remaining_pages(io_ctl);
1337
1338 /* Everything is written out, now we dirty the pages in the file. */
1339 ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
1340 i_size_read(inode), &cached_state);
1341 if (ret)
1342 goto out_nospc;
1343
1344 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1345 up_write(&block_group->data_rwsem);
1346 /*
1347 * Release the pages and unlock the extent, we will flush
1348 * them out later
1349 */
1350 io_ctl_drop_pages(io_ctl);
1351
1352 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1353 i_size_read(inode) - 1, &cached_state);
1354
1355 /*
1356 * at this point the pages are under IO and we're happy,
1357 * The caller is responsible for waiting on them and updating the
1358 * the cache and the inode
1359 */
1360 io_ctl->entries = entries;
1361 io_ctl->bitmaps = bitmaps;
1362
1363 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1364 if (ret)
1365 goto out;
1366
1367 return 0;
1368
1369 out:
1370 io_ctl->inode = NULL;
1371 io_ctl_free(io_ctl);
1372 if (ret) {
1373 invalidate_inode_pages2(inode->i_mapping);
1374 BTRFS_I(inode)->generation = 0;
1375 }
1376 btrfs_update_inode(trans, root, inode);
1377 if (must_iput)
1378 iput(inode);
1379 return ret;
1380
1381 out_nospc_locked:
1382 cleanup_bitmap_list(&bitmap_list);
1383 spin_unlock(&ctl->tree_lock);
1384 mutex_unlock(&ctl->cache_writeout_mutex);
1385
1386 out_nospc:
1387 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1388
1389 out_unlock:
1390 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1391 up_write(&block_group->data_rwsem);
1392
1393 goto out;
1394 }
1395
1396 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
1397 struct btrfs_block_group *block_group,
1398 struct btrfs_path *path)
1399 {
1400 struct btrfs_fs_info *fs_info = trans->fs_info;
1401 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1402 struct inode *inode;
1403 int ret = 0;
1404
1405 spin_lock(&block_group->lock);
1406 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1407 spin_unlock(&block_group->lock);
1408 return 0;
1409 }
1410 spin_unlock(&block_group->lock);
1411
1412 inode = lookup_free_space_inode(block_group, path);
1413 if (IS_ERR(inode))
1414 return 0;
1415
1416 ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
1417 block_group, &block_group->io_ctl, trans);
1418 if (ret) {
1419 #ifdef DEBUG
1420 btrfs_err(fs_info,
1421 "failed to write free space cache for block group %llu",
1422 block_group->start);
1423 #endif
1424 spin_lock(&block_group->lock);
1425 block_group->disk_cache_state = BTRFS_DC_ERROR;
1426 spin_unlock(&block_group->lock);
1427
1428 block_group->io_ctl.inode = NULL;
1429 iput(inode);
1430 }
1431
1432 /*
1433 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1434 * to wait for IO and put the inode
1435 */
1436
1437 return ret;
1438 }
1439
1440 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1441 u64 offset)
1442 {
1443 ASSERT(offset >= bitmap_start);
1444 offset -= bitmap_start;
1445 return (unsigned long)(div_u64(offset, unit));
1446 }
1447
1448 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1449 {
1450 return (unsigned long)(div_u64(bytes, unit));
1451 }
1452
1453 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1454 u64 offset)
1455 {
1456 u64 bitmap_start;
1457 u64 bytes_per_bitmap;
1458
1459 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1460 bitmap_start = offset - ctl->start;
1461 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1462 bitmap_start *= bytes_per_bitmap;
1463 bitmap_start += ctl->start;
1464
1465 return bitmap_start;
1466 }
1467
1468 static int tree_insert_offset(struct rb_root *root, u64 offset,
1469 struct rb_node *node, int bitmap)
1470 {
1471 struct rb_node **p = &root->rb_node;
1472 struct rb_node *parent = NULL;
1473 struct btrfs_free_space *info;
1474
1475 while (*p) {
1476 parent = *p;
1477 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1478
1479 if (offset < info->offset) {
1480 p = &(*p)->rb_left;
1481 } else if (offset > info->offset) {
1482 p = &(*p)->rb_right;
1483 } else {
1484 /*
1485 * we could have a bitmap entry and an extent entry
1486 * share the same offset. If this is the case, we want
1487 * the extent entry to always be found first if we do a
1488 * linear search through the tree, since we want to have
1489 * the quickest allocation time, and allocating from an
1490 * extent is faster than allocating from a bitmap. So
1491 * if we're inserting a bitmap and we find an entry at
1492 * this offset, we want to go right, or after this entry
1493 * logically. If we are inserting an extent and we've
1494 * found a bitmap, we want to go left, or before
1495 * logically.
1496 */
1497 if (bitmap) {
1498 if (info->bitmap) {
1499 WARN_ON_ONCE(1);
1500 return -EEXIST;
1501 }
1502 p = &(*p)->rb_right;
1503 } else {
1504 if (!info->bitmap) {
1505 WARN_ON_ONCE(1);
1506 return -EEXIST;
1507 }
1508 p = &(*p)->rb_left;
1509 }
1510 }
1511 }
1512
1513 rb_link_node(node, parent, p);
1514 rb_insert_color(node, root);
1515
1516 return 0;
1517 }
1518
1519 /*
1520 * searches the tree for the given offset.
1521 *
1522 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1523 * want a section that has at least bytes size and comes at or after the given
1524 * offset.
1525 */
1526 static struct btrfs_free_space *
1527 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1528 u64 offset, int bitmap_only, int fuzzy)
1529 {
1530 struct rb_node *n = ctl->free_space_offset.rb_node;
1531 struct btrfs_free_space *entry, *prev = NULL;
1532
1533 /* find entry that is closest to the 'offset' */
1534 while (1) {
1535 if (!n) {
1536 entry = NULL;
1537 break;
1538 }
1539
1540 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1541 prev = entry;
1542
1543 if (offset < entry->offset)
1544 n = n->rb_left;
1545 else if (offset > entry->offset)
1546 n = n->rb_right;
1547 else
1548 break;
1549 }
1550
1551 if (bitmap_only) {
1552 if (!entry)
1553 return NULL;
1554 if (entry->bitmap)
1555 return entry;
1556
1557 /*
1558 * bitmap entry and extent entry may share same offset,
1559 * in that case, bitmap entry comes after extent entry.
1560 */
1561 n = rb_next(n);
1562 if (!n)
1563 return NULL;
1564 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1565 if (entry->offset != offset)
1566 return NULL;
1567
1568 WARN_ON(!entry->bitmap);
1569 return entry;
1570 } else if (entry) {
1571 if (entry->bitmap) {
1572 /*
1573 * if previous extent entry covers the offset,
1574 * we should return it instead of the bitmap entry
1575 */
1576 n = rb_prev(&entry->offset_index);
1577 if (n) {
1578 prev = rb_entry(n, struct btrfs_free_space,
1579 offset_index);
1580 if (!prev->bitmap &&
1581 prev->offset + prev->bytes > offset)
1582 entry = prev;
1583 }
1584 }
1585 return entry;
1586 }
1587
1588 if (!prev)
1589 return NULL;
1590
1591 /* find last entry before the 'offset' */
1592 entry = prev;
1593 if (entry->offset > offset) {
1594 n = rb_prev(&entry->offset_index);
1595 if (n) {
1596 entry = rb_entry(n, struct btrfs_free_space,
1597 offset_index);
1598 ASSERT(entry->offset <= offset);
1599 } else {
1600 if (fuzzy)
1601 return entry;
1602 else
1603 return NULL;
1604 }
1605 }
1606
1607 if (entry->bitmap) {
1608 n = rb_prev(&entry->offset_index);
1609 if (n) {
1610 prev = rb_entry(n, struct btrfs_free_space,
1611 offset_index);
1612 if (!prev->bitmap &&
1613 prev->offset + prev->bytes > offset)
1614 return prev;
1615 }
1616 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1617 return entry;
1618 } else if (entry->offset + entry->bytes > offset)
1619 return entry;
1620
1621 if (!fuzzy)
1622 return NULL;
1623
1624 while (1) {
1625 if (entry->bitmap) {
1626 if (entry->offset + BITS_PER_BITMAP *
1627 ctl->unit > offset)
1628 break;
1629 } else {
1630 if (entry->offset + entry->bytes > offset)
1631 break;
1632 }
1633
1634 n = rb_next(&entry->offset_index);
1635 if (!n)
1636 return NULL;
1637 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1638 }
1639 return entry;
1640 }
1641
1642 static inline void
1643 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1644 struct btrfs_free_space *info)
1645 {
1646 rb_erase(&info->offset_index, &ctl->free_space_offset);
1647 ctl->free_extents--;
1648
1649 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1650 ctl->discardable_extents[BTRFS_STAT_CURR]--;
1651 ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes;
1652 }
1653 }
1654
1655 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1656 struct btrfs_free_space *info)
1657 {
1658 __unlink_free_space(ctl, info);
1659 ctl->free_space -= info->bytes;
1660 }
1661
1662 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1663 struct btrfs_free_space *info)
1664 {
1665 int ret = 0;
1666
1667 ASSERT(info->bytes || info->bitmap);
1668 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1669 &info->offset_index, (info->bitmap != NULL));
1670 if (ret)
1671 return ret;
1672
1673 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1674 ctl->discardable_extents[BTRFS_STAT_CURR]++;
1675 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
1676 }
1677
1678 ctl->free_space += info->bytes;
1679 ctl->free_extents++;
1680 return ret;
1681 }
1682
1683 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1684 {
1685 struct btrfs_block_group *block_group = ctl->private;
1686 u64 max_bytes;
1687 u64 bitmap_bytes;
1688 u64 extent_bytes;
1689 u64 size = block_group->length;
1690 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1691 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1692
1693 max_bitmaps = max_t(u64, max_bitmaps, 1);
1694
1695 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1696
1697 /*
1698 * We are trying to keep the total amount of memory used per 1GiB of
1699 * space to be MAX_CACHE_BYTES_PER_GIG. However, with a reclamation
1700 * mechanism of pulling extents >= FORCE_EXTENT_THRESHOLD out of
1701 * bitmaps, we may end up using more memory than this.
1702 */
1703 if (size < SZ_1G)
1704 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1705 else
1706 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1707
1708 bitmap_bytes = ctl->total_bitmaps * ctl->unit;
1709
1710 /*
1711 * we want the extent entry threshold to always be at most 1/2 the max
1712 * bytes we can have, or whatever is less than that.
1713 */
1714 extent_bytes = max_bytes - bitmap_bytes;
1715 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1716
1717 ctl->extents_thresh =
1718 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1719 }
1720
1721 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1722 struct btrfs_free_space *info,
1723 u64 offset, u64 bytes)
1724 {
1725 unsigned long start, count, end;
1726 int extent_delta = -1;
1727
1728 start = offset_to_bit(info->offset, ctl->unit, offset);
1729 count = bytes_to_bits(bytes, ctl->unit);
1730 end = start + count;
1731 ASSERT(end <= BITS_PER_BITMAP);
1732
1733 bitmap_clear(info->bitmap, start, count);
1734
1735 info->bytes -= bytes;
1736 if (info->max_extent_size > ctl->unit)
1737 info->max_extent_size = 0;
1738
1739 if (start && test_bit(start - 1, info->bitmap))
1740 extent_delta++;
1741
1742 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1743 extent_delta++;
1744
1745 info->bitmap_extents += extent_delta;
1746 if (!btrfs_free_space_trimmed(info)) {
1747 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1748 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
1749 }
1750 }
1751
1752 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1753 struct btrfs_free_space *info, u64 offset,
1754 u64 bytes)
1755 {
1756 __bitmap_clear_bits(ctl, info, offset, bytes);
1757 ctl->free_space -= bytes;
1758 }
1759
1760 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1761 struct btrfs_free_space *info, u64 offset,
1762 u64 bytes)
1763 {
1764 unsigned long start, count, end;
1765 int extent_delta = 1;
1766
1767 start = offset_to_bit(info->offset, ctl->unit, offset);
1768 count = bytes_to_bits(bytes, ctl->unit);
1769 end = start + count;
1770 ASSERT(end <= BITS_PER_BITMAP);
1771
1772 bitmap_set(info->bitmap, start, count);
1773
1774 info->bytes += bytes;
1775 ctl->free_space += bytes;
1776
1777 if (start && test_bit(start - 1, info->bitmap))
1778 extent_delta--;
1779
1780 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1781 extent_delta--;
1782
1783 info->bitmap_extents += extent_delta;
1784 if (!btrfs_free_space_trimmed(info)) {
1785 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1786 ctl->discardable_bytes[BTRFS_STAT_CURR] += bytes;
1787 }
1788 }
1789
1790 /*
1791 * If we can not find suitable extent, we will use bytes to record
1792 * the size of the max extent.
1793 */
1794 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1795 struct btrfs_free_space *bitmap_info, u64 *offset,
1796 u64 *bytes, bool for_alloc)
1797 {
1798 unsigned long found_bits = 0;
1799 unsigned long max_bits = 0;
1800 unsigned long bits, i;
1801 unsigned long next_zero;
1802 unsigned long extent_bits;
1803
1804 /*
1805 * Skip searching the bitmap if we don't have a contiguous section that
1806 * is large enough for this allocation.
1807 */
1808 if (for_alloc &&
1809 bitmap_info->max_extent_size &&
1810 bitmap_info->max_extent_size < *bytes) {
1811 *bytes = bitmap_info->max_extent_size;
1812 return -1;
1813 }
1814
1815 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1816 max_t(u64, *offset, bitmap_info->offset));
1817 bits = bytes_to_bits(*bytes, ctl->unit);
1818
1819 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1820 if (for_alloc && bits == 1) {
1821 found_bits = 1;
1822 break;
1823 }
1824 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1825 BITS_PER_BITMAP, i);
1826 extent_bits = next_zero - i;
1827 if (extent_bits >= bits) {
1828 found_bits = extent_bits;
1829 break;
1830 } else if (extent_bits > max_bits) {
1831 max_bits = extent_bits;
1832 }
1833 i = next_zero;
1834 }
1835
1836 if (found_bits) {
1837 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1838 *bytes = (u64)(found_bits) * ctl->unit;
1839 return 0;
1840 }
1841
1842 *bytes = (u64)(max_bits) * ctl->unit;
1843 bitmap_info->max_extent_size = *bytes;
1844 return -1;
1845 }
1846
1847 static inline u64 get_max_extent_size(struct btrfs_free_space *entry)
1848 {
1849 if (entry->bitmap)
1850 return entry->max_extent_size;
1851 return entry->bytes;
1852 }
1853
1854 /* Cache the size of the max extent in bytes */
1855 static struct btrfs_free_space *
1856 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1857 unsigned long align, u64 *max_extent_size)
1858 {
1859 struct btrfs_free_space *entry;
1860 struct rb_node *node;
1861 u64 tmp;
1862 u64 align_off;
1863 int ret;
1864
1865 if (!ctl->free_space_offset.rb_node)
1866 goto out;
1867
1868 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1869 if (!entry)
1870 goto out;
1871
1872 for (node = &entry->offset_index; node; node = rb_next(node)) {
1873 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1874 if (entry->bytes < *bytes) {
1875 *max_extent_size = max(get_max_extent_size(entry),
1876 *max_extent_size);
1877 continue;
1878 }
1879
1880 /* make sure the space returned is big enough
1881 * to match our requested alignment
1882 */
1883 if (*bytes >= align) {
1884 tmp = entry->offset - ctl->start + align - 1;
1885 tmp = div64_u64(tmp, align);
1886 tmp = tmp * align + ctl->start;
1887 align_off = tmp - entry->offset;
1888 } else {
1889 align_off = 0;
1890 tmp = entry->offset;
1891 }
1892
1893 if (entry->bytes < *bytes + align_off) {
1894 *max_extent_size = max(get_max_extent_size(entry),
1895 *max_extent_size);
1896 continue;
1897 }
1898
1899 if (entry->bitmap) {
1900 u64 size = *bytes;
1901
1902 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1903 if (!ret) {
1904 *offset = tmp;
1905 *bytes = size;
1906 return entry;
1907 } else {
1908 *max_extent_size =
1909 max(get_max_extent_size(entry),
1910 *max_extent_size);
1911 }
1912 continue;
1913 }
1914
1915 *offset = tmp;
1916 *bytes = entry->bytes - align_off;
1917 return entry;
1918 }
1919 out:
1920 return NULL;
1921 }
1922
1923 static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl,
1924 struct btrfs_free_space *bitmap_info)
1925 {
1926 struct btrfs_block_group *block_group = ctl->private;
1927 u64 bytes = bitmap_info->bytes;
1928 unsigned int rs, re;
1929 int count = 0;
1930
1931 if (!block_group || !bytes)
1932 return count;
1933
1934 bitmap_for_each_set_region(bitmap_info->bitmap, rs, re, 0,
1935 BITS_PER_BITMAP) {
1936 bytes -= (rs - re) * ctl->unit;
1937 count++;
1938
1939 if (!bytes)
1940 break;
1941 }
1942
1943 return count;
1944 }
1945
1946 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1947 struct btrfs_free_space *info, u64 offset)
1948 {
1949 info->offset = offset_to_bitmap(ctl, offset);
1950 info->bytes = 0;
1951 info->bitmap_extents = 0;
1952 INIT_LIST_HEAD(&info->list);
1953 link_free_space(ctl, info);
1954 ctl->total_bitmaps++;
1955
1956 ctl->op->recalc_thresholds(ctl);
1957 }
1958
1959 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1960 struct btrfs_free_space *bitmap_info)
1961 {
1962 /*
1963 * Normally when this is called, the bitmap is completely empty. However,
1964 * if we are blowing up the free space cache for one reason or another
1965 * via __btrfs_remove_free_space_cache(), then it may not be freed and
1966 * we may leave stats on the table.
1967 */
1968 if (bitmap_info->bytes && !btrfs_free_space_trimmed(bitmap_info)) {
1969 ctl->discardable_extents[BTRFS_STAT_CURR] -=
1970 bitmap_info->bitmap_extents;
1971 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bitmap_info->bytes;
1972
1973 }
1974 unlink_free_space(ctl, bitmap_info);
1975 kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
1976 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1977 ctl->total_bitmaps--;
1978 ctl->op->recalc_thresholds(ctl);
1979 }
1980
1981 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1982 struct btrfs_free_space *bitmap_info,
1983 u64 *offset, u64 *bytes)
1984 {
1985 u64 end;
1986 u64 search_start, search_bytes;
1987 int ret;
1988
1989 again:
1990 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1991
1992 /*
1993 * We need to search for bits in this bitmap. We could only cover some
1994 * of the extent in this bitmap thanks to how we add space, so we need
1995 * to search for as much as it as we can and clear that amount, and then
1996 * go searching for the next bit.
1997 */
1998 search_start = *offset;
1999 search_bytes = ctl->unit;
2000 search_bytes = min(search_bytes, end - search_start + 1);
2001 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
2002 false);
2003 if (ret < 0 || search_start != *offset)
2004 return -EINVAL;
2005
2006 /* We may have found more bits than what we need */
2007 search_bytes = min(search_bytes, *bytes);
2008
2009 /* Cannot clear past the end of the bitmap */
2010 search_bytes = min(search_bytes, end - search_start + 1);
2011
2012 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
2013 *offset += search_bytes;
2014 *bytes -= search_bytes;
2015
2016 if (*bytes) {
2017 struct rb_node *next = rb_next(&bitmap_info->offset_index);
2018 if (!bitmap_info->bytes)
2019 free_bitmap(ctl, bitmap_info);
2020
2021 /*
2022 * no entry after this bitmap, but we still have bytes to
2023 * remove, so something has gone wrong.
2024 */
2025 if (!next)
2026 return -EINVAL;
2027
2028 bitmap_info = rb_entry(next, struct btrfs_free_space,
2029 offset_index);
2030
2031 /*
2032 * if the next entry isn't a bitmap we need to return to let the
2033 * extent stuff do its work.
2034 */
2035 if (!bitmap_info->bitmap)
2036 return -EAGAIN;
2037
2038 /*
2039 * Ok the next item is a bitmap, but it may not actually hold
2040 * the information for the rest of this free space stuff, so
2041 * look for it, and if we don't find it return so we can try
2042 * everything over again.
2043 */
2044 search_start = *offset;
2045 search_bytes = ctl->unit;
2046 ret = search_bitmap(ctl, bitmap_info, &search_start,
2047 &search_bytes, false);
2048 if (ret < 0 || search_start != *offset)
2049 return -EAGAIN;
2050
2051 goto again;
2052 } else if (!bitmap_info->bytes)
2053 free_bitmap(ctl, bitmap_info);
2054
2055 return 0;
2056 }
2057
2058 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
2059 struct btrfs_free_space *info, u64 offset,
2060 u64 bytes, enum btrfs_trim_state trim_state)
2061 {
2062 u64 bytes_to_set = 0;
2063 u64 end;
2064
2065 /*
2066 * This is a tradeoff to make bitmap trim state minimal. We mark the
2067 * whole bitmap untrimmed if at any point we add untrimmed regions.
2068 */
2069 if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) {
2070 if (btrfs_free_space_trimmed(info)) {
2071 ctl->discardable_extents[BTRFS_STAT_CURR] +=
2072 info->bitmap_extents;
2073 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
2074 }
2075 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2076 }
2077
2078 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
2079
2080 bytes_to_set = min(end - offset, bytes);
2081
2082 bitmap_set_bits(ctl, info, offset, bytes_to_set);
2083
2084 /*
2085 * We set some bytes, we have no idea what the max extent size is
2086 * anymore.
2087 */
2088 info->max_extent_size = 0;
2089
2090 return bytes_to_set;
2091
2092 }
2093
2094 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
2095 struct btrfs_free_space *info)
2096 {
2097 struct btrfs_block_group *block_group = ctl->private;
2098 struct btrfs_fs_info *fs_info = block_group->fs_info;
2099 bool forced = false;
2100
2101 #ifdef CONFIG_BTRFS_DEBUG
2102 if (btrfs_should_fragment_free_space(block_group))
2103 forced = true;
2104 #endif
2105
2106 /* This is a way to reclaim large regions from the bitmaps. */
2107 if (!forced && info->bytes >= FORCE_EXTENT_THRESHOLD)
2108 return false;
2109
2110 /*
2111 * If we are below the extents threshold then we can add this as an
2112 * extent, and don't have to deal with the bitmap
2113 */
2114 if (!forced && ctl->free_extents < ctl->extents_thresh) {
2115 /*
2116 * If this block group has some small extents we don't want to
2117 * use up all of our free slots in the cache with them, we want
2118 * to reserve them to larger extents, however if we have plenty
2119 * of cache left then go ahead an dadd them, no sense in adding
2120 * the overhead of a bitmap if we don't have to.
2121 */
2122 if (info->bytes <= fs_info->sectorsize * 8) {
2123 if (ctl->free_extents * 3 <= ctl->extents_thresh)
2124 return false;
2125 } else {
2126 return false;
2127 }
2128 }
2129
2130 /*
2131 * The original block groups from mkfs can be really small, like 8
2132 * megabytes, so don't bother with a bitmap for those entries. However
2133 * some block groups can be smaller than what a bitmap would cover but
2134 * are still large enough that they could overflow the 32k memory limit,
2135 * so allow those block groups to still be allowed to have a bitmap
2136 * entry.
2137 */
2138 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->length)
2139 return false;
2140
2141 return true;
2142 }
2143
2144 static const struct btrfs_free_space_op free_space_op = {
2145 .recalc_thresholds = recalculate_thresholds,
2146 .use_bitmap = use_bitmap,
2147 };
2148
2149 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2150 struct btrfs_free_space *info)
2151 {
2152 struct btrfs_free_space *bitmap_info;
2153 struct btrfs_block_group *block_group = NULL;
2154 int added = 0;
2155 u64 bytes, offset, bytes_added;
2156 enum btrfs_trim_state trim_state;
2157 int ret;
2158
2159 bytes = info->bytes;
2160 offset = info->offset;
2161 trim_state = info->trim_state;
2162
2163 if (!ctl->op->use_bitmap(ctl, info))
2164 return 0;
2165
2166 if (ctl->op == &free_space_op)
2167 block_group = ctl->private;
2168 again:
2169 /*
2170 * Since we link bitmaps right into the cluster we need to see if we
2171 * have a cluster here, and if so and it has our bitmap we need to add
2172 * the free space to that bitmap.
2173 */
2174 if (block_group && !list_empty(&block_group->cluster_list)) {
2175 struct btrfs_free_cluster *cluster;
2176 struct rb_node *node;
2177 struct btrfs_free_space *entry;
2178
2179 cluster = list_entry(block_group->cluster_list.next,
2180 struct btrfs_free_cluster,
2181 block_group_list);
2182 spin_lock(&cluster->lock);
2183 node = rb_first(&cluster->root);
2184 if (!node) {
2185 spin_unlock(&cluster->lock);
2186 goto no_cluster_bitmap;
2187 }
2188
2189 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2190 if (!entry->bitmap) {
2191 spin_unlock(&cluster->lock);
2192 goto no_cluster_bitmap;
2193 }
2194
2195 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2196 bytes_added = add_bytes_to_bitmap(ctl, entry, offset,
2197 bytes, trim_state);
2198 bytes -= bytes_added;
2199 offset += bytes_added;
2200 }
2201 spin_unlock(&cluster->lock);
2202 if (!bytes) {
2203 ret = 1;
2204 goto out;
2205 }
2206 }
2207
2208 no_cluster_bitmap:
2209 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2210 1, 0);
2211 if (!bitmap_info) {
2212 ASSERT(added == 0);
2213 goto new_bitmap;
2214 }
2215
2216 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
2217 trim_state);
2218 bytes -= bytes_added;
2219 offset += bytes_added;
2220 added = 0;
2221
2222 if (!bytes) {
2223 ret = 1;
2224 goto out;
2225 } else
2226 goto again;
2227
2228 new_bitmap:
2229 if (info && info->bitmap) {
2230 add_new_bitmap(ctl, info, offset);
2231 added = 1;
2232 info = NULL;
2233 goto again;
2234 } else {
2235 spin_unlock(&ctl->tree_lock);
2236
2237 /* no pre-allocated info, allocate a new one */
2238 if (!info) {
2239 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2240 GFP_NOFS);
2241 if (!info) {
2242 spin_lock(&ctl->tree_lock);
2243 ret = -ENOMEM;
2244 goto out;
2245 }
2246 }
2247
2248 /* allocate the bitmap */
2249 info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
2250 GFP_NOFS);
2251 info->trim_state = BTRFS_TRIM_STATE_TRIMMED;
2252 spin_lock(&ctl->tree_lock);
2253 if (!info->bitmap) {
2254 ret = -ENOMEM;
2255 goto out;
2256 }
2257 goto again;
2258 }
2259
2260 out:
2261 if (info) {
2262 if (info->bitmap)
2263 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2264 info->bitmap);
2265 kmem_cache_free(btrfs_free_space_cachep, info);
2266 }
2267
2268 return ret;
2269 }
2270
2271 /*
2272 * Free space merging rules:
2273 * 1) Merge trimmed areas together
2274 * 2) Let untrimmed areas coalesce with trimmed areas
2275 * 3) Always pull neighboring regions from bitmaps
2276 *
2277 * The above rules are for when we merge free space based on btrfs_trim_state.
2278 * Rules 2 and 3 are subtle because they are suboptimal, but are done for the
2279 * same reason: to promote larger extent regions which makes life easier for
2280 * find_free_extent(). Rule 2 enables coalescing based on the common path
2281 * being returning free space from btrfs_finish_extent_commit(). So when free
2282 * space is trimmed, it will prevent aggregating trimmed new region and
2283 * untrimmed regions in the rb_tree. Rule 3 is purely to obtain larger extents
2284 * and provide find_free_extent() with the largest extents possible hoping for
2285 * the reuse path.
2286 */
2287 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2288 struct btrfs_free_space *info, bool update_stat)
2289 {
2290 struct btrfs_free_space *left_info;
2291 struct btrfs_free_space *right_info;
2292 bool merged = false;
2293 u64 offset = info->offset;
2294 u64 bytes = info->bytes;
2295 const bool is_trimmed = btrfs_free_space_trimmed(info);
2296
2297 /*
2298 * first we want to see if there is free space adjacent to the range we
2299 * are adding, if there is remove that struct and add a new one to
2300 * cover the entire range
2301 */
2302 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2303 if (right_info && rb_prev(&right_info->offset_index))
2304 left_info = rb_entry(rb_prev(&right_info->offset_index),
2305 struct btrfs_free_space, offset_index);
2306 else
2307 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2308
2309 /* See try_merge_free_space() comment. */
2310 if (right_info && !right_info->bitmap &&
2311 (!is_trimmed || btrfs_free_space_trimmed(right_info))) {
2312 if (update_stat)
2313 unlink_free_space(ctl, right_info);
2314 else
2315 __unlink_free_space(ctl, right_info);
2316 info->bytes += right_info->bytes;
2317 kmem_cache_free(btrfs_free_space_cachep, right_info);
2318 merged = true;
2319 }
2320
2321 /* See try_merge_free_space() comment. */
2322 if (left_info && !left_info->bitmap &&
2323 left_info->offset + left_info->bytes == offset &&
2324 (!is_trimmed || btrfs_free_space_trimmed(left_info))) {
2325 if (update_stat)
2326 unlink_free_space(ctl, left_info);
2327 else
2328 __unlink_free_space(ctl, left_info);
2329 info->offset = left_info->offset;
2330 info->bytes += left_info->bytes;
2331 kmem_cache_free(btrfs_free_space_cachep, left_info);
2332 merged = true;
2333 }
2334
2335 return merged;
2336 }
2337
2338 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2339 struct btrfs_free_space *info,
2340 bool update_stat)
2341 {
2342 struct btrfs_free_space *bitmap;
2343 unsigned long i;
2344 unsigned long j;
2345 const u64 end = info->offset + info->bytes;
2346 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2347 u64 bytes;
2348
2349 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2350 if (!bitmap)
2351 return false;
2352
2353 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2354 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2355 if (j == i)
2356 return false;
2357 bytes = (j - i) * ctl->unit;
2358 info->bytes += bytes;
2359
2360 /* See try_merge_free_space() comment. */
2361 if (!btrfs_free_space_trimmed(bitmap))
2362 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2363
2364 if (update_stat)
2365 bitmap_clear_bits(ctl, bitmap, end, bytes);
2366 else
2367 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2368
2369 if (!bitmap->bytes)
2370 free_bitmap(ctl, bitmap);
2371
2372 return true;
2373 }
2374
2375 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2376 struct btrfs_free_space *info,
2377 bool update_stat)
2378 {
2379 struct btrfs_free_space *bitmap;
2380 u64 bitmap_offset;
2381 unsigned long i;
2382 unsigned long j;
2383 unsigned long prev_j;
2384 u64 bytes;
2385
2386 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2387 /* If we're on a boundary, try the previous logical bitmap. */
2388 if (bitmap_offset == info->offset) {
2389 if (info->offset == 0)
2390 return false;
2391 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2392 }
2393
2394 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2395 if (!bitmap)
2396 return false;
2397
2398 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2399 j = 0;
2400 prev_j = (unsigned long)-1;
2401 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2402 if (j > i)
2403 break;
2404 prev_j = j;
2405 }
2406 if (prev_j == i)
2407 return false;
2408
2409 if (prev_j == (unsigned long)-1)
2410 bytes = (i + 1) * ctl->unit;
2411 else
2412 bytes = (i - prev_j) * ctl->unit;
2413
2414 info->offset -= bytes;
2415 info->bytes += bytes;
2416
2417 /* See try_merge_free_space() comment. */
2418 if (!btrfs_free_space_trimmed(bitmap))
2419 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2420
2421 if (update_stat)
2422 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2423 else
2424 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2425
2426 if (!bitmap->bytes)
2427 free_bitmap(ctl, bitmap);
2428
2429 return true;
2430 }
2431
2432 /*
2433 * We prefer always to allocate from extent entries, both for clustered and
2434 * non-clustered allocation requests. So when attempting to add a new extent
2435 * entry, try to see if there's adjacent free space in bitmap entries, and if
2436 * there is, migrate that space from the bitmaps to the extent.
2437 * Like this we get better chances of satisfying space allocation requests
2438 * because we attempt to satisfy them based on a single cache entry, and never
2439 * on 2 or more entries - even if the entries represent a contiguous free space
2440 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2441 * ends).
2442 */
2443 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2444 struct btrfs_free_space *info,
2445 bool update_stat)
2446 {
2447 /*
2448 * Only work with disconnected entries, as we can change their offset,
2449 * and must be extent entries.
2450 */
2451 ASSERT(!info->bitmap);
2452 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2453
2454 if (ctl->total_bitmaps > 0) {
2455 bool stole_end;
2456 bool stole_front = false;
2457
2458 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2459 if (ctl->total_bitmaps > 0)
2460 stole_front = steal_from_bitmap_to_front(ctl, info,
2461 update_stat);
2462
2463 if (stole_end || stole_front)
2464 try_merge_free_space(ctl, info, update_stat);
2465 }
2466 }
2467
2468 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
2469 struct btrfs_free_space_ctl *ctl,
2470 u64 offset, u64 bytes,
2471 enum btrfs_trim_state trim_state)
2472 {
2473 struct btrfs_block_group *block_group = ctl->private;
2474 struct btrfs_free_space *info;
2475 int ret = 0;
2476 u64 filter_bytes = bytes;
2477
2478 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2479 if (!info)
2480 return -ENOMEM;
2481
2482 info->offset = offset;
2483 info->bytes = bytes;
2484 info->trim_state = trim_state;
2485 RB_CLEAR_NODE(&info->offset_index);
2486
2487 spin_lock(&ctl->tree_lock);
2488
2489 if (try_merge_free_space(ctl, info, true))
2490 goto link;
2491
2492 /*
2493 * There was no extent directly to the left or right of this new
2494 * extent then we know we're going to have to allocate a new extent, so
2495 * before we do that see if we need to drop this into a bitmap
2496 */
2497 ret = insert_into_bitmap(ctl, info);
2498 if (ret < 0) {
2499 goto out;
2500 } else if (ret) {
2501 ret = 0;
2502 goto out;
2503 }
2504 link:
2505 /*
2506 * Only steal free space from adjacent bitmaps if we're sure we're not
2507 * going to add the new free space to existing bitmap entries - because
2508 * that would mean unnecessary work that would be reverted. Therefore
2509 * attempt to steal space from bitmaps if we're adding an extent entry.
2510 */
2511 steal_from_bitmap(ctl, info, true);
2512
2513 filter_bytes = max(filter_bytes, info->bytes);
2514
2515 ret = link_free_space(ctl, info);
2516 if (ret)
2517 kmem_cache_free(btrfs_free_space_cachep, info);
2518 out:
2519 btrfs_discard_update_discardable(block_group, ctl);
2520 spin_unlock(&ctl->tree_lock);
2521
2522 if (ret) {
2523 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2524 ASSERT(ret != -EEXIST);
2525 }
2526
2527 if (trim_state != BTRFS_TRIM_STATE_TRIMMED) {
2528 btrfs_discard_check_filter(block_group, filter_bytes);
2529 btrfs_discard_queue_work(&fs_info->discard_ctl, block_group);
2530 }
2531
2532 return ret;
2533 }
2534
2535 int btrfs_add_free_space(struct btrfs_block_group *block_group,
2536 u64 bytenr, u64 size)
2537 {
2538 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2539
2540 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
2541 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2542
2543 return __btrfs_add_free_space(block_group->fs_info,
2544 block_group->free_space_ctl,
2545 bytenr, size, trim_state);
2546 }
2547
2548 /*
2549 * This is a subtle distinction because when adding free space back in general,
2550 * we want it to be added as untrimmed for async. But in the case where we add
2551 * it on loading of a block group, we want to consider it trimmed.
2552 */
2553 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
2554 u64 bytenr, u64 size)
2555 {
2556 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2557
2558 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) ||
2559 btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
2560 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2561
2562 return __btrfs_add_free_space(block_group->fs_info,
2563 block_group->free_space_ctl,
2564 bytenr, size, trim_state);
2565 }
2566
2567 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
2568 u64 offset, u64 bytes)
2569 {
2570 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2571 struct btrfs_free_space *info;
2572 int ret;
2573 bool re_search = false;
2574
2575 spin_lock(&ctl->tree_lock);
2576
2577 again:
2578 ret = 0;
2579 if (!bytes)
2580 goto out_lock;
2581
2582 info = tree_search_offset(ctl, offset, 0, 0);
2583 if (!info) {
2584 /*
2585 * oops didn't find an extent that matched the space we wanted
2586 * to remove, look for a bitmap instead
2587 */
2588 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2589 1, 0);
2590 if (!info) {
2591 /*
2592 * If we found a partial bit of our free space in a
2593 * bitmap but then couldn't find the other part this may
2594 * be a problem, so WARN about it.
2595 */
2596 WARN_ON(re_search);
2597 goto out_lock;
2598 }
2599 }
2600
2601 re_search = false;
2602 if (!info->bitmap) {
2603 unlink_free_space(ctl, info);
2604 if (offset == info->offset) {
2605 u64 to_free = min(bytes, info->bytes);
2606
2607 info->bytes -= to_free;
2608 info->offset += to_free;
2609 if (info->bytes) {
2610 ret = link_free_space(ctl, info);
2611 WARN_ON(ret);
2612 } else {
2613 kmem_cache_free(btrfs_free_space_cachep, info);
2614 }
2615
2616 offset += to_free;
2617 bytes -= to_free;
2618 goto again;
2619 } else {
2620 u64 old_end = info->bytes + info->offset;
2621
2622 info->bytes = offset - info->offset;
2623 ret = link_free_space(ctl, info);
2624 WARN_ON(ret);
2625 if (ret)
2626 goto out_lock;
2627
2628 /* Not enough bytes in this entry to satisfy us */
2629 if (old_end < offset + bytes) {
2630 bytes -= old_end - offset;
2631 offset = old_end;
2632 goto again;
2633 } else if (old_end == offset + bytes) {
2634 /* all done */
2635 goto out_lock;
2636 }
2637 spin_unlock(&ctl->tree_lock);
2638
2639 ret = __btrfs_add_free_space(block_group->fs_info, ctl,
2640 offset + bytes,
2641 old_end - (offset + bytes),
2642 info->trim_state);
2643 WARN_ON(ret);
2644 goto out;
2645 }
2646 }
2647
2648 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2649 if (ret == -EAGAIN) {
2650 re_search = true;
2651 goto again;
2652 }
2653 out_lock:
2654 btrfs_discard_update_discardable(block_group, ctl);
2655 spin_unlock(&ctl->tree_lock);
2656 out:
2657 return ret;
2658 }
2659
2660 void btrfs_dump_free_space(struct btrfs_block_group *block_group,
2661 u64 bytes)
2662 {
2663 struct btrfs_fs_info *fs_info = block_group->fs_info;
2664 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2665 struct btrfs_free_space *info;
2666 struct rb_node *n;
2667 int count = 0;
2668
2669 spin_lock(&ctl->tree_lock);
2670 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2671 info = rb_entry(n, struct btrfs_free_space, offset_index);
2672 if (info->bytes >= bytes && !block_group->ro)
2673 count++;
2674 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2675 info->offset, info->bytes,
2676 (info->bitmap) ? "yes" : "no");
2677 }
2678 spin_unlock(&ctl->tree_lock);
2679 btrfs_info(fs_info, "block group has cluster?: %s",
2680 list_empty(&block_group->cluster_list) ? "no" : "yes");
2681 btrfs_info(fs_info,
2682 "%d blocks of free space at or bigger than bytes is", count);
2683 }
2684
2685 void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group)
2686 {
2687 struct btrfs_fs_info *fs_info = block_group->fs_info;
2688 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2689
2690 spin_lock_init(&ctl->tree_lock);
2691 ctl->unit = fs_info->sectorsize;
2692 ctl->start = block_group->start;
2693 ctl->private = block_group;
2694 ctl->op = &free_space_op;
2695 INIT_LIST_HEAD(&ctl->trimming_ranges);
2696 mutex_init(&ctl->cache_writeout_mutex);
2697
2698 /*
2699 * we only want to have 32k of ram per block group for keeping
2700 * track of free space, and if we pass 1/2 of that we want to
2701 * start converting things over to using bitmaps
2702 */
2703 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2704 }
2705
2706 /*
2707 * for a given cluster, put all of its extents back into the free
2708 * space cache. If the block group passed doesn't match the block group
2709 * pointed to by the cluster, someone else raced in and freed the
2710 * cluster already. In that case, we just return without changing anything
2711 */
2712 static int
2713 __btrfs_return_cluster_to_free_space(
2714 struct btrfs_block_group *block_group,
2715 struct btrfs_free_cluster *cluster)
2716 {
2717 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2718 struct btrfs_free_space *entry;
2719 struct rb_node *node;
2720
2721 spin_lock(&cluster->lock);
2722 if (cluster->block_group != block_group)
2723 goto out;
2724
2725 cluster->block_group = NULL;
2726 cluster->window_start = 0;
2727 list_del_init(&cluster->block_group_list);
2728
2729 node = rb_first(&cluster->root);
2730 while (node) {
2731 bool bitmap;
2732
2733 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2734 node = rb_next(&entry->offset_index);
2735 rb_erase(&entry->offset_index, &cluster->root);
2736 RB_CLEAR_NODE(&entry->offset_index);
2737
2738 bitmap = (entry->bitmap != NULL);
2739 if (!bitmap) {
2740 /* Merging treats extents as if they were new */
2741 if (!btrfs_free_space_trimmed(entry)) {
2742 ctl->discardable_extents[BTRFS_STAT_CURR]--;
2743 ctl->discardable_bytes[BTRFS_STAT_CURR] -=
2744 entry->bytes;
2745 }
2746
2747 try_merge_free_space(ctl, entry, false);
2748 steal_from_bitmap(ctl, entry, false);
2749
2750 /* As we insert directly, update these statistics */
2751 if (!btrfs_free_space_trimmed(entry)) {
2752 ctl->discardable_extents[BTRFS_STAT_CURR]++;
2753 ctl->discardable_bytes[BTRFS_STAT_CURR] +=
2754 entry->bytes;
2755 }
2756 }
2757 tree_insert_offset(&ctl->free_space_offset,
2758 entry->offset, &entry->offset_index, bitmap);
2759 }
2760 cluster->root = RB_ROOT;
2761
2762 out:
2763 spin_unlock(&cluster->lock);
2764 btrfs_put_block_group(block_group);
2765 return 0;
2766 }
2767
2768 static void __btrfs_remove_free_space_cache_locked(
2769 struct btrfs_free_space_ctl *ctl)
2770 {
2771 struct btrfs_free_space *info;
2772 struct rb_node *node;
2773
2774 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2775 info = rb_entry(node, struct btrfs_free_space, offset_index);
2776 if (!info->bitmap) {
2777 unlink_free_space(ctl, info);
2778 kmem_cache_free(btrfs_free_space_cachep, info);
2779 } else {
2780 free_bitmap(ctl, info);
2781 }
2782
2783 cond_resched_lock(&ctl->tree_lock);
2784 }
2785 }
2786
2787 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2788 {
2789 spin_lock(&ctl->tree_lock);
2790 __btrfs_remove_free_space_cache_locked(ctl);
2791 if (ctl->private)
2792 btrfs_discard_update_discardable(ctl->private, ctl);
2793 spin_unlock(&ctl->tree_lock);
2794 }
2795
2796 void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group)
2797 {
2798 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2799 struct btrfs_free_cluster *cluster;
2800 struct list_head *head;
2801
2802 spin_lock(&ctl->tree_lock);
2803 while ((head = block_group->cluster_list.next) !=
2804 &block_group->cluster_list) {
2805 cluster = list_entry(head, struct btrfs_free_cluster,
2806 block_group_list);
2807
2808 WARN_ON(cluster->block_group != block_group);
2809 __btrfs_return_cluster_to_free_space(block_group, cluster);
2810
2811 cond_resched_lock(&ctl->tree_lock);
2812 }
2813 __btrfs_remove_free_space_cache_locked(ctl);
2814 btrfs_discard_update_discardable(block_group, ctl);
2815 spin_unlock(&ctl->tree_lock);
2816
2817 }
2818
2819 /**
2820 * btrfs_is_free_space_trimmed - see if everything is trimmed
2821 * @block_group: block_group of interest
2822 *
2823 * Walk @block_group's free space rb_tree to determine if everything is trimmed.
2824 */
2825 bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group)
2826 {
2827 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2828 struct btrfs_free_space *info;
2829 struct rb_node *node;
2830 bool ret = true;
2831
2832 spin_lock(&ctl->tree_lock);
2833 node = rb_first(&ctl->free_space_offset);
2834
2835 while (node) {
2836 info = rb_entry(node, struct btrfs_free_space, offset_index);
2837
2838 if (!btrfs_free_space_trimmed(info)) {
2839 ret = false;
2840 break;
2841 }
2842
2843 node = rb_next(node);
2844 }
2845
2846 spin_unlock(&ctl->tree_lock);
2847 return ret;
2848 }
2849
2850 u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
2851 u64 offset, u64 bytes, u64 empty_size,
2852 u64 *max_extent_size)
2853 {
2854 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2855 struct btrfs_discard_ctl *discard_ctl =
2856 &block_group->fs_info->discard_ctl;
2857 struct btrfs_free_space *entry = NULL;
2858 u64 bytes_search = bytes + empty_size;
2859 u64 ret = 0;
2860 u64 align_gap = 0;
2861 u64 align_gap_len = 0;
2862 enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2863
2864 spin_lock(&ctl->tree_lock);
2865 entry = find_free_space(ctl, &offset, &bytes_search,
2866 block_group->full_stripe_len, max_extent_size);
2867 if (!entry)
2868 goto out;
2869
2870 ret = offset;
2871 if (entry->bitmap) {
2872 bitmap_clear_bits(ctl, entry, offset, bytes);
2873
2874 if (!btrfs_free_space_trimmed(entry))
2875 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
2876
2877 if (!entry->bytes)
2878 free_bitmap(ctl, entry);
2879 } else {
2880 unlink_free_space(ctl, entry);
2881 align_gap_len = offset - entry->offset;
2882 align_gap = entry->offset;
2883 align_gap_trim_state = entry->trim_state;
2884
2885 if (!btrfs_free_space_trimmed(entry))
2886 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
2887
2888 entry->offset = offset + bytes;
2889 WARN_ON(entry->bytes < bytes + align_gap_len);
2890
2891 entry->bytes -= bytes + align_gap_len;
2892 if (!entry->bytes)
2893 kmem_cache_free(btrfs_free_space_cachep, entry);
2894 else
2895 link_free_space(ctl, entry);
2896 }
2897 out:
2898 btrfs_discard_update_discardable(block_group, ctl);
2899 spin_unlock(&ctl->tree_lock);
2900
2901 if (align_gap_len)
2902 __btrfs_add_free_space(block_group->fs_info, ctl,
2903 align_gap, align_gap_len,
2904 align_gap_trim_state);
2905 return ret;
2906 }
2907
2908 /*
2909 * given a cluster, put all of its extents back into the free space
2910 * cache. If a block group is passed, this function will only free
2911 * a cluster that belongs to the passed block group.
2912 *
2913 * Otherwise, it'll get a reference on the block group pointed to by the
2914 * cluster and remove the cluster from it.
2915 */
2916 int btrfs_return_cluster_to_free_space(
2917 struct btrfs_block_group *block_group,
2918 struct btrfs_free_cluster *cluster)
2919 {
2920 struct btrfs_free_space_ctl *ctl;
2921 int ret;
2922
2923 /* first, get a safe pointer to the block group */
2924 spin_lock(&cluster->lock);
2925 if (!block_group) {
2926 block_group = cluster->block_group;
2927 if (!block_group) {
2928 spin_unlock(&cluster->lock);
2929 return 0;
2930 }
2931 } else if (cluster->block_group != block_group) {
2932 /* someone else has already freed it don't redo their work */
2933 spin_unlock(&cluster->lock);
2934 return 0;
2935 }
2936 atomic_inc(&block_group->count);
2937 spin_unlock(&cluster->lock);
2938
2939 ctl = block_group->free_space_ctl;
2940
2941 /* now return any extents the cluster had on it */
2942 spin_lock(&ctl->tree_lock);
2943 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2944 spin_unlock(&ctl->tree_lock);
2945
2946 btrfs_discard_queue_work(&block_group->fs_info->discard_ctl, block_group);
2947
2948 /* finally drop our ref */
2949 btrfs_put_block_group(block_group);
2950 return ret;
2951 }
2952
2953 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group *block_group,
2954 struct btrfs_free_cluster *cluster,
2955 struct btrfs_free_space *entry,
2956 u64 bytes, u64 min_start,
2957 u64 *max_extent_size)
2958 {
2959 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2960 int err;
2961 u64 search_start = cluster->window_start;
2962 u64 search_bytes = bytes;
2963 u64 ret = 0;
2964
2965 search_start = min_start;
2966 search_bytes = bytes;
2967
2968 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2969 if (err) {
2970 *max_extent_size = max(get_max_extent_size(entry),
2971 *max_extent_size);
2972 return 0;
2973 }
2974
2975 ret = search_start;
2976 __bitmap_clear_bits(ctl, entry, ret, bytes);
2977
2978 return ret;
2979 }
2980
2981 /*
2982 * given a cluster, try to allocate 'bytes' from it, returns 0
2983 * if it couldn't find anything suitably large, or a logical disk offset
2984 * if things worked out
2985 */
2986 u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
2987 struct btrfs_free_cluster *cluster, u64 bytes,
2988 u64 min_start, u64 *max_extent_size)
2989 {
2990 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2991 struct btrfs_discard_ctl *discard_ctl =
2992 &block_group->fs_info->discard_ctl;
2993 struct btrfs_free_space *entry = NULL;
2994 struct rb_node *node;
2995 u64 ret = 0;
2996
2997 spin_lock(&cluster->lock);
2998 if (bytes > cluster->max_size)
2999 goto out;
3000
3001 if (cluster->block_group != block_group)
3002 goto out;
3003
3004 node = rb_first(&cluster->root);
3005 if (!node)
3006 goto out;
3007
3008 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3009 while (1) {
3010 if (entry->bytes < bytes)
3011 *max_extent_size = max(get_max_extent_size(entry),
3012 *max_extent_size);
3013
3014 if (entry->bytes < bytes ||
3015 (!entry->bitmap && entry->offset < min_start)) {
3016 node = rb_next(&entry->offset_index);
3017 if (!node)
3018 break;
3019 entry = rb_entry(node, struct btrfs_free_space,
3020 offset_index);
3021 continue;
3022 }
3023
3024 if (entry->bitmap) {
3025 ret = btrfs_alloc_from_bitmap(block_group,
3026 cluster, entry, bytes,
3027 cluster->window_start,
3028 max_extent_size);
3029 if (ret == 0) {
3030 node = rb_next(&entry->offset_index);
3031 if (!node)
3032 break;
3033 entry = rb_entry(node, struct btrfs_free_space,
3034 offset_index);
3035 continue;
3036 }
3037 cluster->window_start += bytes;
3038 } else {
3039 ret = entry->offset;
3040
3041 entry->offset += bytes;
3042 entry->bytes -= bytes;
3043 }
3044
3045 if (entry->bytes == 0)
3046 rb_erase(&entry->offset_index, &cluster->root);
3047 break;
3048 }
3049 out:
3050 spin_unlock(&cluster->lock);
3051
3052 if (!ret)
3053 return 0;
3054
3055 spin_lock(&ctl->tree_lock);
3056
3057 if (!btrfs_free_space_trimmed(entry))
3058 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3059
3060 ctl->free_space -= bytes;
3061 if (!entry->bitmap && !btrfs_free_space_trimmed(entry))
3062 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
3063 if (entry->bytes == 0) {
3064 ctl->free_extents--;
3065 if (entry->bitmap) {
3066 kmem_cache_free(btrfs_free_space_bitmap_cachep,
3067 entry->bitmap);
3068 ctl->total_bitmaps--;
3069 ctl->op->recalc_thresholds(ctl);
3070 } else if (!btrfs_free_space_trimmed(entry)) {
3071 ctl->discardable_extents[BTRFS_STAT_CURR]--;
3072 }
3073 kmem_cache_free(btrfs_free_space_cachep, entry);
3074 }
3075
3076 spin_unlock(&ctl->tree_lock);
3077
3078 return ret;
3079 }
3080
3081 static int btrfs_bitmap_cluster(struct btrfs_block_group *block_group,
3082 struct btrfs_free_space *entry,
3083 struct btrfs_free_cluster *cluster,
3084 u64 offset, u64 bytes,
3085 u64 cont1_bytes, u64 min_bytes)
3086 {
3087 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3088 unsigned long next_zero;
3089 unsigned long i;
3090 unsigned long want_bits;
3091 unsigned long min_bits;
3092 unsigned long found_bits;
3093 unsigned long max_bits = 0;
3094 unsigned long start = 0;
3095 unsigned long total_found = 0;
3096 int ret;
3097
3098 i = offset_to_bit(entry->offset, ctl->unit,
3099 max_t(u64, offset, entry->offset));
3100 want_bits = bytes_to_bits(bytes, ctl->unit);
3101 min_bits = bytes_to_bits(min_bytes, ctl->unit);
3102
3103 /*
3104 * Don't bother looking for a cluster in this bitmap if it's heavily
3105 * fragmented.
3106 */
3107 if (entry->max_extent_size &&
3108 entry->max_extent_size < cont1_bytes)
3109 return -ENOSPC;
3110 again:
3111 found_bits = 0;
3112 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
3113 next_zero = find_next_zero_bit(entry->bitmap,
3114 BITS_PER_BITMAP, i);
3115 if (next_zero - i >= min_bits) {
3116 found_bits = next_zero - i;
3117 if (found_bits > max_bits)
3118 max_bits = found_bits;
3119 break;
3120 }
3121 if (next_zero - i > max_bits)
3122 max_bits = next_zero - i;
3123 i = next_zero;
3124 }
3125
3126 if (!found_bits) {
3127 entry->max_extent_size = (u64)max_bits * ctl->unit;
3128 return -ENOSPC;
3129 }
3130
3131 if (!total_found) {
3132 start = i;
3133 cluster->max_size = 0;
3134 }
3135
3136 total_found += found_bits;
3137
3138 if (cluster->max_size < found_bits * ctl->unit)
3139 cluster->max_size = found_bits * ctl->unit;
3140
3141 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
3142 i = next_zero + 1;
3143 goto again;
3144 }
3145
3146 cluster->window_start = start * ctl->unit + entry->offset;
3147 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3148 ret = tree_insert_offset(&cluster->root, entry->offset,
3149 &entry->offset_index, 1);
3150 ASSERT(!ret); /* -EEXIST; Logic error */
3151
3152 trace_btrfs_setup_cluster(block_group, cluster,
3153 total_found * ctl->unit, 1);
3154 return 0;
3155 }
3156
3157 /*
3158 * This searches the block group for just extents to fill the cluster with.
3159 * Try to find a cluster with at least bytes total bytes, at least one
3160 * extent of cont1_bytes, and other clusters of at least min_bytes.
3161 */
3162 static noinline int
3163 setup_cluster_no_bitmap(struct btrfs_block_group *block_group,
3164 struct btrfs_free_cluster *cluster,
3165 struct list_head *bitmaps, u64 offset, u64 bytes,
3166 u64 cont1_bytes, u64 min_bytes)
3167 {
3168 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3169 struct btrfs_free_space *first = NULL;
3170 struct btrfs_free_space *entry = NULL;
3171 struct btrfs_free_space *last;
3172 struct rb_node *node;
3173 u64 window_free;
3174 u64 max_extent;
3175 u64 total_size = 0;
3176
3177 entry = tree_search_offset(ctl, offset, 0, 1);
3178 if (!entry)
3179 return -ENOSPC;
3180
3181 /*
3182 * We don't want bitmaps, so just move along until we find a normal
3183 * extent entry.
3184 */
3185 while (entry->bitmap || entry->bytes < min_bytes) {
3186 if (entry->bitmap && list_empty(&entry->list))
3187 list_add_tail(&entry->list, bitmaps);
3188 node = rb_next(&entry->offset_index);
3189 if (!node)
3190 return -ENOSPC;
3191 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3192 }
3193
3194 window_free = entry->bytes;
3195 max_extent = entry->bytes;
3196 first = entry;
3197 last = entry;
3198
3199 for (node = rb_next(&entry->offset_index); node;
3200 node = rb_next(&entry->offset_index)) {
3201 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3202
3203 if (entry->bitmap) {
3204 if (list_empty(&entry->list))
3205 list_add_tail(&entry->list, bitmaps);
3206 continue;
3207 }
3208
3209 if (entry->bytes < min_bytes)
3210 continue;
3211
3212 last = entry;
3213 window_free += entry->bytes;
3214 if (entry->bytes > max_extent)
3215 max_extent = entry->bytes;
3216 }
3217
3218 if (window_free < bytes || max_extent < cont1_bytes)
3219 return -ENOSPC;
3220
3221 cluster->window_start = first->offset;
3222
3223 node = &first->offset_index;
3224
3225 /*
3226 * now we've found our entries, pull them out of the free space
3227 * cache and put them into the cluster rbtree
3228 */
3229 do {
3230 int ret;
3231
3232 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3233 node = rb_next(&entry->offset_index);
3234 if (entry->bitmap || entry->bytes < min_bytes)
3235 continue;
3236
3237 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3238 ret = tree_insert_offset(&cluster->root, entry->offset,
3239 &entry->offset_index, 0);
3240 total_size += entry->bytes;
3241 ASSERT(!ret); /* -EEXIST; Logic error */
3242 } while (node && entry != last);
3243
3244 cluster->max_size = max_extent;
3245 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
3246 return 0;
3247 }
3248
3249 /*
3250 * This specifically looks for bitmaps that may work in the cluster, we assume
3251 * that we have already failed to find extents that will work.
3252 */
3253 static noinline int
3254 setup_cluster_bitmap(struct btrfs_block_group *block_group,
3255 struct btrfs_free_cluster *cluster,
3256 struct list_head *bitmaps, u64 offset, u64 bytes,
3257 u64 cont1_bytes, u64 min_bytes)
3258 {
3259 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3260 struct btrfs_free_space *entry = NULL;
3261 int ret = -ENOSPC;
3262 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
3263
3264 if (ctl->total_bitmaps == 0)
3265 return -ENOSPC;
3266
3267 /*
3268 * The bitmap that covers offset won't be in the list unless offset
3269 * is just its start offset.
3270 */
3271 if (!list_empty(bitmaps))
3272 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
3273
3274 if (!entry || entry->offset != bitmap_offset) {
3275 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
3276 if (entry && list_empty(&entry->list))
3277 list_add(&entry->list, bitmaps);
3278 }
3279
3280 list_for_each_entry(entry, bitmaps, list) {
3281 if (entry->bytes < bytes)
3282 continue;
3283 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3284 bytes, cont1_bytes, min_bytes);
3285 if (!ret)
3286 return 0;
3287 }
3288
3289 /*
3290 * The bitmaps list has all the bitmaps that record free space
3291 * starting after offset, so no more search is required.
3292 */
3293 return -ENOSPC;
3294 }
3295
3296 /*
3297 * here we try to find a cluster of blocks in a block group. The goal
3298 * is to find at least bytes+empty_size.
3299 * We might not find them all in one contiguous area.
3300 *
3301 * returns zero and sets up cluster if things worked out, otherwise
3302 * it returns -enospc
3303 */
3304 int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
3305 struct btrfs_free_cluster *cluster,
3306 u64 offset, u64 bytes, u64 empty_size)
3307 {
3308 struct btrfs_fs_info *fs_info = block_group->fs_info;
3309 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3310 struct btrfs_free_space *entry, *tmp;
3311 LIST_HEAD(bitmaps);
3312 u64 min_bytes;
3313 u64 cont1_bytes;
3314 int ret;
3315
3316 /*
3317 * Choose the minimum extent size we'll require for this
3318 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3319 * For metadata, allow allocates with smaller extents. For
3320 * data, keep it dense.
3321 */
3322 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3323 cont1_bytes = min_bytes = bytes + empty_size;
3324 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3325 cont1_bytes = bytes;
3326 min_bytes = fs_info->sectorsize;
3327 } else {
3328 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3329 min_bytes = fs_info->sectorsize;
3330 }
3331
3332 spin_lock(&ctl->tree_lock);
3333
3334 /*
3335 * If we know we don't have enough space to make a cluster don't even
3336 * bother doing all the work to try and find one.
3337 */
3338 if (ctl->free_space < bytes) {
3339 spin_unlock(&ctl->tree_lock);
3340 return -ENOSPC;
3341 }
3342
3343 spin_lock(&cluster->lock);
3344
3345 /* someone already found a cluster, hooray */
3346 if (cluster->block_group) {
3347 ret = 0;
3348 goto out;
3349 }
3350
3351 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3352 min_bytes);
3353
3354 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3355 bytes + empty_size,
3356 cont1_bytes, min_bytes);
3357 if (ret)
3358 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3359 offset, bytes + empty_size,
3360 cont1_bytes, min_bytes);
3361
3362 /* Clear our temporary list */
3363 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3364 list_del_init(&entry->list);
3365
3366 if (!ret) {
3367 atomic_inc(&block_group->count);
3368 list_add_tail(&cluster->block_group_list,
3369 &block_group->cluster_list);
3370 cluster->block_group = block_group;
3371 } else {
3372 trace_btrfs_failed_cluster_setup(block_group);
3373 }
3374 out:
3375 spin_unlock(&cluster->lock);
3376 spin_unlock(&ctl->tree_lock);
3377
3378 return ret;
3379 }
3380
3381 /*
3382 * simple code to zero out a cluster
3383 */
3384 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3385 {
3386 spin_lock_init(&cluster->lock);
3387 spin_lock_init(&cluster->refill_lock);
3388 cluster->root = RB_ROOT;
3389 cluster->max_size = 0;
3390 cluster->fragmented = false;
3391 INIT_LIST_HEAD(&cluster->block_group_list);
3392 cluster->block_group = NULL;
3393 }
3394
3395 static int do_trimming(struct btrfs_block_group *block_group,
3396 u64 *total_trimmed, u64 start, u64 bytes,
3397 u64 reserved_start, u64 reserved_bytes,
3398 enum btrfs_trim_state reserved_trim_state,
3399 struct btrfs_trim_range *trim_entry)
3400 {
3401 struct btrfs_space_info *space_info = block_group->space_info;
3402 struct btrfs_fs_info *fs_info = block_group->fs_info;
3403 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3404 int ret;
3405 int update = 0;
3406 const u64 end = start + bytes;
3407 const u64 reserved_end = reserved_start + reserved_bytes;
3408 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3409 u64 trimmed = 0;
3410
3411 spin_lock(&space_info->lock);
3412 spin_lock(&block_group->lock);
3413 if (!block_group->ro) {
3414 block_group->reserved += reserved_bytes;
3415 space_info->bytes_reserved += reserved_bytes;
3416 update = 1;
3417 }
3418 spin_unlock(&block_group->lock);
3419 spin_unlock(&space_info->lock);
3420
3421 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3422 if (!ret) {
3423 *total_trimmed += trimmed;
3424 trim_state = BTRFS_TRIM_STATE_TRIMMED;
3425 }
3426
3427 mutex_lock(&ctl->cache_writeout_mutex);
3428 if (reserved_start < start)
3429 __btrfs_add_free_space(fs_info, ctl, reserved_start,
3430 start - reserved_start,
3431 reserved_trim_state);
3432 if (start + bytes < reserved_start + reserved_bytes)
3433 __btrfs_add_free_space(fs_info, ctl, end, reserved_end - end,
3434 reserved_trim_state);
3435 __btrfs_add_free_space(fs_info, ctl, start, bytes, trim_state);
3436 list_del(&trim_entry->list);
3437 mutex_unlock(&ctl->cache_writeout_mutex);
3438
3439 if (update) {
3440 spin_lock(&space_info->lock);
3441 spin_lock(&block_group->lock);
3442 if (block_group->ro)
3443 space_info->bytes_readonly += reserved_bytes;
3444 block_group->reserved -= reserved_bytes;
3445 space_info->bytes_reserved -= reserved_bytes;
3446 spin_unlock(&block_group->lock);
3447 spin_unlock(&space_info->lock);
3448 }
3449
3450 return ret;
3451 }
3452
3453 /*
3454 * If @async is set, then we will trim 1 region and return.
3455 */
3456 static int trim_no_bitmap(struct btrfs_block_group *block_group,
3457 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3458 bool async)
3459 {
3460 struct btrfs_discard_ctl *discard_ctl =
3461 &block_group->fs_info->discard_ctl;
3462 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3463 struct btrfs_free_space *entry;
3464 struct rb_node *node;
3465 int ret = 0;
3466 u64 extent_start;
3467 u64 extent_bytes;
3468 enum btrfs_trim_state extent_trim_state;
3469 u64 bytes;
3470 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3471
3472 while (start < end) {
3473 struct btrfs_trim_range trim_entry;
3474
3475 mutex_lock(&ctl->cache_writeout_mutex);
3476 spin_lock(&ctl->tree_lock);
3477
3478 if (ctl->free_space < minlen)
3479 goto out_unlock;
3480
3481 entry = tree_search_offset(ctl, start, 0, 1);
3482 if (!entry)
3483 goto out_unlock;
3484
3485 /* Skip bitmaps and if async, already trimmed entries */
3486 while (entry->bitmap ||
3487 (async && btrfs_free_space_trimmed(entry))) {
3488 node = rb_next(&entry->offset_index);
3489 if (!node)
3490 goto out_unlock;
3491 entry = rb_entry(node, struct btrfs_free_space,
3492 offset_index);
3493 }
3494
3495 if (entry->offset >= end)
3496 goto out_unlock;
3497
3498 extent_start = entry->offset;
3499 extent_bytes = entry->bytes;
3500 extent_trim_state = entry->trim_state;
3501 if (async) {
3502 start = entry->offset;
3503 bytes = entry->bytes;
3504 if (bytes < minlen) {
3505 spin_unlock(&ctl->tree_lock);
3506 mutex_unlock(&ctl->cache_writeout_mutex);
3507 goto next;
3508 }
3509 unlink_free_space(ctl, entry);
3510 /*
3511 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3512 * If X < BTRFS_ASYNC_DISCARD_MIN_FILTER, we won't trim
3513 * X when we come back around. So trim it now.
3514 */
3515 if (max_discard_size &&
3516 bytes >= (max_discard_size +
3517 BTRFS_ASYNC_DISCARD_MIN_FILTER)) {
3518 bytes = max_discard_size;
3519 extent_bytes = max_discard_size;
3520 entry->offset += max_discard_size;
3521 entry->bytes -= max_discard_size;
3522 link_free_space(ctl, entry);
3523 } else {
3524 kmem_cache_free(btrfs_free_space_cachep, entry);
3525 }
3526 } else {
3527 start = max(start, extent_start);
3528 bytes = min(extent_start + extent_bytes, end) - start;
3529 if (bytes < minlen) {
3530 spin_unlock(&ctl->tree_lock);
3531 mutex_unlock(&ctl->cache_writeout_mutex);
3532 goto next;
3533 }
3534
3535 unlink_free_space(ctl, entry);
3536 kmem_cache_free(btrfs_free_space_cachep, entry);
3537 }
3538
3539 spin_unlock(&ctl->tree_lock);
3540 trim_entry.start = extent_start;
3541 trim_entry.bytes = extent_bytes;
3542 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3543 mutex_unlock(&ctl->cache_writeout_mutex);
3544
3545 ret = do_trimming(block_group, total_trimmed, start, bytes,
3546 extent_start, extent_bytes, extent_trim_state,
3547 &trim_entry);
3548 if (ret) {
3549 block_group->discard_cursor = start + bytes;
3550 break;
3551 }
3552 next:
3553 start += bytes;
3554 block_group->discard_cursor = start;
3555 if (async && *total_trimmed)
3556 break;
3557
3558 if (fatal_signal_pending(current)) {
3559 ret = -ERESTARTSYS;
3560 break;
3561 }
3562
3563 cond_resched();
3564 }
3565
3566 return ret;
3567
3568 out_unlock:
3569 block_group->discard_cursor = btrfs_block_group_end(block_group);
3570 spin_unlock(&ctl->tree_lock);
3571 mutex_unlock(&ctl->cache_writeout_mutex);
3572
3573 return ret;
3574 }
3575
3576 /*
3577 * If we break out of trimming a bitmap prematurely, we should reset the
3578 * trimming bit. In a rather contrieved case, it's possible to race here so
3579 * reset the state to BTRFS_TRIM_STATE_UNTRIMMED.
3580 *
3581 * start = start of bitmap
3582 * end = near end of bitmap
3583 *
3584 * Thread 1: Thread 2:
3585 * trim_bitmaps(start)
3586 * trim_bitmaps(end)
3587 * end_trimming_bitmap()
3588 * reset_trimming_bitmap()
3589 */
3590 static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset)
3591 {
3592 struct btrfs_free_space *entry;
3593
3594 spin_lock(&ctl->tree_lock);
3595 entry = tree_search_offset(ctl, offset, 1, 0);
3596 if (entry) {
3597 if (btrfs_free_space_trimmed(entry)) {
3598 ctl->discardable_extents[BTRFS_STAT_CURR] +=
3599 entry->bitmap_extents;
3600 ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes;
3601 }
3602 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3603 }
3604
3605 spin_unlock(&ctl->tree_lock);
3606 }
3607
3608 static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl,
3609 struct btrfs_free_space *entry)
3610 {
3611 if (btrfs_free_space_trimming_bitmap(entry)) {
3612 entry->trim_state = BTRFS_TRIM_STATE_TRIMMED;
3613 ctl->discardable_extents[BTRFS_STAT_CURR] -=
3614 entry->bitmap_extents;
3615 ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes;
3616 }
3617 }
3618
3619 /*
3620 * If @async is set, then we will trim 1 region and return.
3621 */
3622 static int trim_bitmaps(struct btrfs_block_group *block_group,
3623 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3624 u64 maxlen, bool async)
3625 {
3626 struct btrfs_discard_ctl *discard_ctl =
3627 &block_group->fs_info->discard_ctl;
3628 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3629 struct btrfs_free_space *entry;
3630 int ret = 0;
3631 int ret2;
3632 u64 bytes;
3633 u64 offset = offset_to_bitmap(ctl, start);
3634 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3635
3636 while (offset < end) {
3637 bool next_bitmap = false;
3638 struct btrfs_trim_range trim_entry;
3639
3640 mutex_lock(&ctl->cache_writeout_mutex);
3641 spin_lock(&ctl->tree_lock);
3642
3643 if (ctl->free_space < minlen) {
3644 block_group->discard_cursor =
3645 btrfs_block_group_end(block_group);
3646 spin_unlock(&ctl->tree_lock);
3647 mutex_unlock(&ctl->cache_writeout_mutex);
3648 break;
3649 }
3650
3651 entry = tree_search_offset(ctl, offset, 1, 0);
3652 /*
3653 * Bitmaps are marked trimmed lossily now to prevent constant
3654 * discarding of the same bitmap (the reason why we are bound
3655 * by the filters). So, retrim the block group bitmaps when we
3656 * are preparing to punt to the unused_bgs list. This uses
3657 * @minlen to determine if we are in BTRFS_DISCARD_INDEX_UNUSED
3658 * which is the only discard index which sets minlen to 0.
3659 */
3660 if (!entry || (async && minlen && start == offset &&
3661 btrfs_free_space_trimmed(entry))) {
3662 spin_unlock(&ctl->tree_lock);
3663 mutex_unlock(&ctl->cache_writeout_mutex);
3664 next_bitmap = true;
3665 goto next;
3666 }
3667
3668 /*
3669 * Async discard bitmap trimming begins at by setting the start
3670 * to be key.objectid and the offset_to_bitmap() aligns to the
3671 * start of the bitmap. This lets us know we are fully
3672 * scanning the bitmap rather than only some portion of it.
3673 */
3674 if (start == offset)
3675 entry->trim_state = BTRFS_TRIM_STATE_TRIMMING;
3676
3677 bytes = minlen;
3678 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3679 if (ret2 || start >= end) {
3680 /*
3681 * We lossily consider a bitmap trimmed if we only skip
3682 * over regions <= BTRFS_ASYNC_DISCARD_MIN_FILTER.
3683 */
3684 if (ret2 && minlen <= BTRFS_ASYNC_DISCARD_MIN_FILTER)
3685 end_trimming_bitmap(ctl, entry);
3686 else
3687 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3688 spin_unlock(&ctl->tree_lock);
3689 mutex_unlock(&ctl->cache_writeout_mutex);
3690 next_bitmap = true;
3691 goto next;
3692 }
3693
3694 /*
3695 * We already trimmed a region, but are using the locking above
3696 * to reset the trim_state.
3697 */
3698 if (async && *total_trimmed) {
3699 spin_unlock(&ctl->tree_lock);
3700 mutex_unlock(&ctl->cache_writeout_mutex);
3701 goto out;
3702 }
3703
3704 bytes = min(bytes, end - start);
3705 if (bytes < minlen || (async && maxlen && bytes > maxlen)) {
3706 spin_unlock(&ctl->tree_lock);
3707 mutex_unlock(&ctl->cache_writeout_mutex);
3708 goto next;
3709 }
3710
3711 /*
3712 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3713 * If X < @minlen, we won't trim X when we come back around.
3714 * So trim it now. We differ here from trimming extents as we
3715 * don't keep individual state per bit.
3716 */
3717 if (async &&
3718 max_discard_size &&
3719 bytes > (max_discard_size + minlen))
3720 bytes = max_discard_size;
3721
3722 bitmap_clear_bits(ctl, entry, start, bytes);
3723 if (entry->bytes == 0)
3724 free_bitmap(ctl, entry);
3725
3726 spin_unlock(&ctl->tree_lock);
3727 trim_entry.start = start;
3728 trim_entry.bytes = bytes;
3729 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3730 mutex_unlock(&ctl->cache_writeout_mutex);
3731
3732 ret = do_trimming(block_group, total_trimmed, start, bytes,
3733 start, bytes, 0, &trim_entry);
3734 if (ret) {
3735 reset_trimming_bitmap(ctl, offset);
3736 block_group->discard_cursor =
3737 btrfs_block_group_end(block_group);
3738 break;
3739 }
3740 next:
3741 if (next_bitmap) {
3742 offset += BITS_PER_BITMAP * ctl->unit;
3743 start = offset;
3744 } else {
3745 start += bytes;
3746 }
3747 block_group->discard_cursor = start;
3748
3749 if (fatal_signal_pending(current)) {
3750 if (start != offset)
3751 reset_trimming_bitmap(ctl, offset);
3752 ret = -ERESTARTSYS;
3753 break;
3754 }
3755
3756 cond_resched();
3757 }
3758
3759 if (offset >= end)
3760 block_group->discard_cursor = end;
3761
3762 out:
3763 return ret;
3764 }
3765
3766 void btrfs_get_block_group_trimming(struct btrfs_block_group *cache)
3767 {
3768 atomic_inc(&cache->trimming);
3769 }
3770
3771 void btrfs_put_block_group_trimming(struct btrfs_block_group *block_group)
3772 {
3773 struct btrfs_fs_info *fs_info = block_group->fs_info;
3774 struct extent_map_tree *em_tree;
3775 struct extent_map *em;
3776 bool cleanup;
3777
3778 spin_lock(&block_group->lock);
3779 cleanup = (atomic_dec_and_test(&block_group->trimming) &&
3780 block_group->removed);
3781 spin_unlock(&block_group->lock);
3782
3783 if (cleanup) {
3784 mutex_lock(&fs_info->chunk_mutex);
3785 em_tree = &fs_info->mapping_tree;
3786 write_lock(&em_tree->lock);
3787 em = lookup_extent_mapping(em_tree, block_group->start,
3788 1);
3789 BUG_ON(!em); /* logic error, can't happen */
3790 remove_extent_mapping(em_tree, em);
3791 write_unlock(&em_tree->lock);
3792 mutex_unlock(&fs_info->chunk_mutex);
3793
3794 /* once for us and once for the tree */
3795 free_extent_map(em);
3796 free_extent_map(em);
3797
3798 /*
3799 * We've left one free space entry and other tasks trimming
3800 * this block group have left 1 entry each one. Free them.
3801 */
3802 __btrfs_remove_free_space_cache(block_group->free_space_ctl);
3803 }
3804 }
3805
3806 int btrfs_trim_block_group(struct btrfs_block_group *block_group,
3807 u64 *trimmed, u64 start, u64 end, u64 minlen)
3808 {
3809 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3810 int ret;
3811 u64 rem = 0;
3812
3813 *trimmed = 0;
3814
3815 spin_lock(&block_group->lock);
3816 if (block_group->removed) {
3817 spin_unlock(&block_group->lock);
3818 return 0;
3819 }
3820 btrfs_get_block_group_trimming(block_group);
3821 spin_unlock(&block_group->lock);
3822
3823 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, false);
3824 if (ret)
3825 goto out;
3826
3827 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, 0, false);
3828 div64_u64_rem(end, BITS_PER_BITMAP * ctl->unit, &rem);
3829 /* If we ended in the middle of a bitmap, reset the trimming flag */
3830 if (rem)
3831 reset_trimming_bitmap(ctl, offset_to_bitmap(ctl, end));
3832 out:
3833 btrfs_put_block_group_trimming(block_group);
3834 return ret;
3835 }
3836
3837 int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
3838 u64 *trimmed, u64 start, u64 end, u64 minlen,
3839 bool async)
3840 {
3841 int ret;
3842
3843 *trimmed = 0;
3844
3845 spin_lock(&block_group->lock);
3846 if (block_group->removed) {
3847 spin_unlock(&block_group->lock);
3848 return 0;
3849 }
3850 btrfs_get_block_group_trimming(block_group);
3851 spin_unlock(&block_group->lock);
3852
3853 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, async);
3854 btrfs_put_block_group_trimming(block_group);
3855
3856 return ret;
3857 }
3858
3859 int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
3860 u64 *trimmed, u64 start, u64 end, u64 minlen,
3861 u64 maxlen, bool async)
3862 {
3863 int ret;
3864
3865 *trimmed = 0;
3866
3867 spin_lock(&block_group->lock);
3868 if (block_group->removed) {
3869 spin_unlock(&block_group->lock);
3870 return 0;
3871 }
3872 btrfs_get_block_group_trimming(block_group);
3873 spin_unlock(&block_group->lock);
3874
3875 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, maxlen,
3876 async);
3877
3878 btrfs_put_block_group_trimming(block_group);
3879
3880 return ret;
3881 }
3882
3883 /*
3884 * Find the left-most item in the cache tree, and then return the
3885 * smallest inode number in the item.
3886 *
3887 * Note: the returned inode number may not be the smallest one in
3888 * the tree, if the left-most item is a bitmap.
3889 */
3890 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3891 {
3892 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3893 struct btrfs_free_space *entry = NULL;
3894 u64 ino = 0;
3895
3896 spin_lock(&ctl->tree_lock);
3897
3898 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3899 goto out;
3900
3901 entry = rb_entry(rb_first(&ctl->free_space_offset),
3902 struct btrfs_free_space, offset_index);
3903
3904 if (!entry->bitmap) {
3905 ino = entry->offset;
3906
3907 unlink_free_space(ctl, entry);
3908 entry->offset++;
3909 entry->bytes--;
3910 if (!entry->bytes)
3911 kmem_cache_free(btrfs_free_space_cachep, entry);
3912 else
3913 link_free_space(ctl, entry);
3914 } else {
3915 u64 offset = 0;
3916 u64 count = 1;
3917 int ret;
3918
3919 ret = search_bitmap(ctl, entry, &offset, &count, true);
3920 /* Logic error; Should be empty if it can't find anything */
3921 ASSERT(!ret);
3922
3923 ino = offset;
3924 bitmap_clear_bits(ctl, entry, offset, 1);
3925 if (entry->bytes == 0)
3926 free_bitmap(ctl, entry);
3927 }
3928 out:
3929 spin_unlock(&ctl->tree_lock);
3930
3931 return ino;
3932 }
3933
3934 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3935 struct btrfs_path *path)
3936 {
3937 struct inode *inode = NULL;
3938
3939 spin_lock(&root->ino_cache_lock);
3940 if (root->ino_cache_inode)
3941 inode = igrab(root->ino_cache_inode);
3942 spin_unlock(&root->ino_cache_lock);
3943 if (inode)
3944 return inode;
3945
3946 inode = __lookup_free_space_inode(root, path, 0);
3947 if (IS_ERR(inode))
3948 return inode;
3949
3950 spin_lock(&root->ino_cache_lock);
3951 if (!btrfs_fs_closing(root->fs_info))
3952 root->ino_cache_inode = igrab(inode);
3953 spin_unlock(&root->ino_cache_lock);
3954
3955 return inode;
3956 }
3957
3958 int create_free_ino_inode(struct btrfs_root *root,
3959 struct btrfs_trans_handle *trans,
3960 struct btrfs_path *path)
3961 {
3962 return __create_free_space_inode(root, trans, path,
3963 BTRFS_FREE_INO_OBJECTID, 0);
3964 }
3965
3966 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3967 {
3968 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3969 struct btrfs_path *path;
3970 struct inode *inode;
3971 int ret = 0;
3972 u64 root_gen = btrfs_root_generation(&root->root_item);
3973
3974 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3975 return 0;
3976
3977 /*
3978 * If we're unmounting then just return, since this does a search on the
3979 * normal root and not the commit root and we could deadlock.
3980 */
3981 if (btrfs_fs_closing(fs_info))
3982 return 0;
3983
3984 path = btrfs_alloc_path();
3985 if (!path)
3986 return 0;
3987
3988 inode = lookup_free_ino_inode(root, path);
3989 if (IS_ERR(inode))
3990 goto out;
3991
3992 if (root_gen != BTRFS_I(inode)->generation)
3993 goto out_put;
3994
3995 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3996
3997 if (ret < 0)
3998 btrfs_err(fs_info,
3999 "failed to load free ino cache for root %llu",
4000 root->root_key.objectid);
4001 out_put:
4002 iput(inode);
4003 out:
4004 btrfs_free_path(path);
4005 return ret;
4006 }
4007
4008 int btrfs_write_out_ino_cache(struct btrfs_root *root,
4009 struct btrfs_trans_handle *trans,
4010 struct btrfs_path *path,
4011 struct inode *inode)
4012 {
4013 struct btrfs_fs_info *fs_info = root->fs_info;
4014 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
4015 int ret;
4016 struct btrfs_io_ctl io_ctl;
4017 bool release_metadata = true;
4018
4019 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
4020 return 0;
4021
4022 memset(&io_ctl, 0, sizeof(io_ctl));
4023 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
4024 if (!ret) {
4025 /*
4026 * At this point writepages() didn't error out, so our metadata
4027 * reservation is released when the writeback finishes, at
4028 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
4029 * with or without an error.
4030 */
4031 release_metadata = false;
4032 ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
4033 }
4034
4035 if (ret) {
4036 if (release_metadata)
4037 btrfs_delalloc_release_metadata(BTRFS_I(inode),
4038 inode->i_size, true);
4039 #ifdef DEBUG
4040 btrfs_err(fs_info,
4041 "failed to write free ino cache for root %llu",
4042 root->root_key.objectid);
4043 #endif
4044 }
4045
4046 return ret;
4047 }
4048
4049 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4050 /*
4051 * Use this if you need to make a bitmap or extent entry specifically, it
4052 * doesn't do any of the merging that add_free_space does, this acts a lot like
4053 * how the free space cache loading stuff works, so you can get really weird
4054 * configurations.
4055 */
4056 int test_add_free_space_entry(struct btrfs_block_group *cache,
4057 u64 offset, u64 bytes, bool bitmap)
4058 {
4059 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4060 struct btrfs_free_space *info = NULL, *bitmap_info;
4061 void *map = NULL;
4062 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_TRIMMED;
4063 u64 bytes_added;
4064 int ret;
4065
4066 again:
4067 if (!info) {
4068 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
4069 if (!info)
4070 return -ENOMEM;
4071 }
4072
4073 if (!bitmap) {
4074 spin_lock(&ctl->tree_lock);
4075 info->offset = offset;
4076 info->bytes = bytes;
4077 info->max_extent_size = 0;
4078 ret = link_free_space(ctl, info);
4079 spin_unlock(&ctl->tree_lock);
4080 if (ret)
4081 kmem_cache_free(btrfs_free_space_cachep, info);
4082 return ret;
4083 }
4084
4085 if (!map) {
4086 map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
4087 if (!map) {
4088 kmem_cache_free(btrfs_free_space_cachep, info);
4089 return -ENOMEM;
4090 }
4091 }
4092
4093 spin_lock(&ctl->tree_lock);
4094 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4095 1, 0);
4096 if (!bitmap_info) {
4097 info->bitmap = map;
4098 map = NULL;
4099 add_new_bitmap(ctl, info, offset);
4100 bitmap_info = info;
4101 info = NULL;
4102 }
4103
4104 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
4105 trim_state);
4106
4107 bytes -= bytes_added;
4108 offset += bytes_added;
4109 spin_unlock(&ctl->tree_lock);
4110
4111 if (bytes)
4112 goto again;
4113
4114 if (info)
4115 kmem_cache_free(btrfs_free_space_cachep, info);
4116 if (map)
4117 kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
4118 return 0;
4119 }
4120
4121 /*
4122 * Checks to see if the given range is in the free space cache. This is really
4123 * just used to check the absence of space, so if there is free space in the
4124 * range at all we will return 1.
4125 */
4126 int test_check_exists(struct btrfs_block_group *cache,
4127 u64 offset, u64 bytes)
4128 {
4129 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4130 struct btrfs_free_space *info;
4131 int ret = 0;
4132
4133 spin_lock(&ctl->tree_lock);
4134 info = tree_search_offset(ctl, offset, 0, 0);
4135 if (!info) {
4136 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4137 1, 0);
4138 if (!info)
4139 goto out;
4140 }
4141
4142 have_info:
4143 if (info->bitmap) {
4144 u64 bit_off, bit_bytes;
4145 struct rb_node *n;
4146 struct btrfs_free_space *tmp;
4147
4148 bit_off = offset;
4149 bit_bytes = ctl->unit;
4150 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
4151 if (!ret) {
4152 if (bit_off == offset) {
4153 ret = 1;
4154 goto out;
4155 } else if (bit_off > offset &&
4156 offset + bytes > bit_off) {
4157 ret = 1;
4158 goto out;
4159 }
4160 }
4161
4162 n = rb_prev(&info->offset_index);
4163 while (n) {
4164 tmp = rb_entry(n, struct btrfs_free_space,
4165 offset_index);
4166 if (tmp->offset + tmp->bytes < offset)
4167 break;
4168 if (offset + bytes < tmp->offset) {
4169 n = rb_prev(&tmp->offset_index);
4170 continue;
4171 }
4172 info = tmp;
4173 goto have_info;
4174 }
4175
4176 n = rb_next(&info->offset_index);
4177 while (n) {
4178 tmp = rb_entry(n, struct btrfs_free_space,
4179 offset_index);
4180 if (offset + bytes < tmp->offset)
4181 break;
4182 if (tmp->offset + tmp->bytes < offset) {
4183 n = rb_next(&tmp->offset_index);
4184 continue;
4185 }
4186 info = tmp;
4187 goto have_info;
4188 }
4189
4190 ret = 0;
4191 goto out;
4192 }
4193
4194 if (info->offset == offset) {
4195 ret = 1;
4196 goto out;
4197 }
4198
4199 if (offset > info->offset && offset < info->offset + info->bytes)
4200 ret = 1;
4201 out:
4202 spin_unlock(&ctl->tree_lock);
4203 return ret;
4204 }
4205 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Linux with added FPC-III support