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Btrfs: fix xattr loss after power failure
[linux/fpc-iii.git] / fs / btrfs / free-space-cache.c
blobe5b569bebc731e816622b40f0c5f531b3d45b295
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 "ctree.h"
14 #include "free-space-cache.h"
15 #include "transaction.h"
16 #include "disk-io.h"
17 #include "extent_io.h"
18 #include "inode-map.h"
19 #include "volumes.h"
20
21 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
22 #define MAX_CACHE_BYTES_PER_GIG SZ_32K
23
24 struct btrfs_trim_range {
25 u64 start;
26 u64 bytes;
27 struct list_head list;
28 };
29
30 static int link_free_space(struct btrfs_free_space_ctl *ctl,
31 struct btrfs_free_space *info);
32 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
33 struct btrfs_free_space *info);
34 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
35 struct btrfs_trans_handle *trans,
36 struct btrfs_io_ctl *io_ctl,
37 struct btrfs_path *path);
38
39 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
40 struct btrfs_path *path,
41 u64 offset)
42 {
43 struct btrfs_fs_info *fs_info = root->fs_info;
44 struct btrfs_key key;
45 struct btrfs_key location;
46 struct btrfs_disk_key disk_key;
47 struct btrfs_free_space_header *header;
48 struct extent_buffer *leaf;
49 struct inode *inode = NULL;
50 int ret;
51
52 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
53 key.offset = offset;
54 key.type = 0;
55
56 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
57 if (ret < 0)
58 return ERR_PTR(ret);
59 if (ret > 0) {
60 btrfs_release_path(path);
61 return ERR_PTR(-ENOENT);
62 }
63
64 leaf = path->nodes[0];
65 header = btrfs_item_ptr(leaf, path->slots[0],
66 struct btrfs_free_space_header);
67 btrfs_free_space_key(leaf, header, &disk_key);
68 btrfs_disk_key_to_cpu(&location, &disk_key);
69 btrfs_release_path(path);
70
71 inode = btrfs_iget(fs_info->sb, &location, root, NULL);
72 if (IS_ERR(inode))
73 return inode;
74 if (is_bad_inode(inode)) {
75 iput(inode);
76 return ERR_PTR(-ENOENT);
77 }
78
79 mapping_set_gfp_mask(inode->i_mapping,
80 mapping_gfp_constraint(inode->i_mapping,
81 ~(__GFP_FS | __GFP_HIGHMEM)));
82
83 return inode;
84 }
85
86 struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
87 struct btrfs_block_group_cache
88 *block_group, struct btrfs_path *path)
89 {
90 struct inode *inode = NULL;
91 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
92
93 spin_lock(&block_group->lock);
94 if (block_group->inode)
95 inode = igrab(block_group->inode);
96 spin_unlock(&block_group->lock);
97 if (inode)
98 return inode;
99
100 inode = __lookup_free_space_inode(fs_info->tree_root, path,
101 block_group->key.objectid);
102 if (IS_ERR(inode))
103 return inode;
104
105 spin_lock(&block_group->lock);
106 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
107 btrfs_info(fs_info, "Old style space inode found, converting.");
108 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
109 BTRFS_INODE_NODATACOW;
110 block_group->disk_cache_state = BTRFS_DC_CLEAR;
111 }
112
113 if (!block_group->iref) {
114 block_group->inode = igrab(inode);
115 block_group->iref = 1;
116 }
117 spin_unlock(&block_group->lock);
118
119 return inode;
120 }
121
122 static int __create_free_space_inode(struct btrfs_root *root,
123 struct btrfs_trans_handle *trans,
124 struct btrfs_path *path,
125 u64 ino, u64 offset)
126 {
127 struct btrfs_key key;
128 struct btrfs_disk_key disk_key;
129 struct btrfs_free_space_header *header;
130 struct btrfs_inode_item *inode_item;
131 struct extent_buffer *leaf;
132 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
133 int ret;
134
135 ret = btrfs_insert_empty_inode(trans, root, path, ino);
136 if (ret)
137 return ret;
138
139 /* We inline crc's for the free disk space cache */
140 if (ino != BTRFS_FREE_INO_OBJECTID)
141 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
142
143 leaf = path->nodes[0];
144 inode_item = btrfs_item_ptr(leaf, path->slots[0],
145 struct btrfs_inode_item);
146 btrfs_item_key(leaf, &disk_key, path->slots[0]);
147 memzero_extent_buffer(leaf, (unsigned long)inode_item,
148 sizeof(*inode_item));
149 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
150 btrfs_set_inode_size(leaf, inode_item, 0);
151 btrfs_set_inode_nbytes(leaf, inode_item, 0);
152 btrfs_set_inode_uid(leaf, inode_item, 0);
153 btrfs_set_inode_gid(leaf, inode_item, 0);
154 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
155 btrfs_set_inode_flags(leaf, inode_item, flags);
156 btrfs_set_inode_nlink(leaf, inode_item, 1);
157 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
158 btrfs_set_inode_block_group(leaf, inode_item, offset);
159 btrfs_mark_buffer_dirty(leaf);
160 btrfs_release_path(path);
161
162 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
163 key.offset = offset;
164 key.type = 0;
165 ret = btrfs_insert_empty_item(trans, root, path, &key,
166 sizeof(struct btrfs_free_space_header));
167 if (ret < 0) {
168 btrfs_release_path(path);
169 return ret;
170 }
171
172 leaf = path->nodes[0];
173 header = btrfs_item_ptr(leaf, path->slots[0],
174 struct btrfs_free_space_header);
175 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
176 btrfs_set_free_space_key(leaf, header, &disk_key);
177 btrfs_mark_buffer_dirty(leaf);
178 btrfs_release_path(path);
179
180 return 0;
181 }
182
183 int create_free_space_inode(struct btrfs_fs_info *fs_info,
184 struct btrfs_trans_handle *trans,
185 struct btrfs_block_group_cache *block_group,
186 struct btrfs_path *path)
187 {
188 int ret;
189 u64 ino;
190
191 ret = btrfs_find_free_objectid(fs_info->tree_root, &ino);
192 if (ret < 0)
193 return ret;
194
195 return __create_free_space_inode(fs_info->tree_root, trans, path, ino,
196 block_group->key.objectid);
197 }
198
199 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
200 struct btrfs_block_rsv *rsv)
201 {
202 u64 needed_bytes;
203 int ret;
204
205 /* 1 for slack space, 1 for updating the inode */
206 needed_bytes = btrfs_calc_trunc_metadata_size(fs_info, 1) +
207 btrfs_calc_trans_metadata_size(fs_info, 1);
208
209 spin_lock(&rsv->lock);
210 if (rsv->reserved < needed_bytes)
211 ret = -ENOSPC;
212 else
213 ret = 0;
214 spin_unlock(&rsv->lock);
215 return ret;
216 }
217
218 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
219 struct btrfs_block_group_cache *block_group,
220 struct inode *inode)
221 {
222 struct btrfs_root *root = BTRFS_I(inode)->root;
223 int ret = 0;
224 bool locked = false;
225
226 if (block_group) {
227 struct btrfs_path *path = btrfs_alloc_path();
228
229 if (!path) {
230 ret = -ENOMEM;
231 goto fail;
232 }
233 locked = true;
234 mutex_lock(&trans->transaction->cache_write_mutex);
235 if (!list_empty(&block_group->io_list)) {
236 list_del_init(&block_group->io_list);
237
238 btrfs_wait_cache_io(trans, block_group, path);
239 btrfs_put_block_group(block_group);
240 }
241
242 /*
243 * now that we've truncated the cache away, its no longer
244 * setup or written
245 */
246 spin_lock(&block_group->lock);
247 block_group->disk_cache_state = BTRFS_DC_CLEAR;
248 spin_unlock(&block_group->lock);
249 btrfs_free_path(path);
250 }
251
252 btrfs_i_size_write(BTRFS_I(inode), 0);
253 truncate_pagecache(inode, 0);
254
255 /*
256 * We don't need an orphan item because truncating the free space cache
257 * will never be split across transactions.
258 * We don't need to check for -EAGAIN because we're a free space
259 * cache inode
260 */
261 ret = btrfs_truncate_inode_items(trans, root, inode,
262 0, BTRFS_EXTENT_DATA_KEY);
263 if (ret)
264 goto fail;
265
266 ret = btrfs_update_inode(trans, root, inode);
267
268 fail:
269 if (locked)
270 mutex_unlock(&trans->transaction->cache_write_mutex);
271 if (ret)
272 btrfs_abort_transaction(trans, ret);
273
274 return ret;
275 }
276
277 static void readahead_cache(struct inode *inode)
278 {
279 struct file_ra_state *ra;
280 unsigned long last_index;
281
282 ra = kzalloc(sizeof(*ra), GFP_NOFS);
283 if (!ra)
284 return;
285
286 file_ra_state_init(ra, inode->i_mapping);
287 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
288
289 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
290
291 kfree(ra);
292 }
293
294 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
295 int write)
296 {
297 int num_pages;
298 int check_crcs = 0;
299
300 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
301
302 if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
303 check_crcs = 1;
304
305 /* Make sure we can fit our crcs into the first page */
306 if (write && check_crcs &&
307 (num_pages * sizeof(u32)) >= PAGE_SIZE)
308 return -ENOSPC;
309
310 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
311
312 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
313 if (!io_ctl->pages)
314 return -ENOMEM;
315
316 io_ctl->num_pages = num_pages;
317 io_ctl->fs_info = btrfs_sb(inode->i_sb);
318 io_ctl->check_crcs = check_crcs;
319 io_ctl->inode = inode;
320
321 return 0;
322 }
323 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
324
325 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
326 {
327 kfree(io_ctl->pages);
328 io_ctl->pages = NULL;
329 }
330
331 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
332 {
333 if (io_ctl->cur) {
334 io_ctl->cur = NULL;
335 io_ctl->orig = NULL;
336 }
337 }
338
339 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
340 {
341 ASSERT(io_ctl->index < io_ctl->num_pages);
342 io_ctl->page = io_ctl->pages[io_ctl->index++];
343 io_ctl->cur = page_address(io_ctl->page);
344 io_ctl->orig = io_ctl->cur;
345 io_ctl->size = PAGE_SIZE;
346 if (clear)
347 clear_page(io_ctl->cur);
348 }
349
350 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
351 {
352 int i;
353
354 io_ctl_unmap_page(io_ctl);
355
356 for (i = 0; i < io_ctl->num_pages; i++) {
357 if (io_ctl->pages[i]) {
358 ClearPageChecked(io_ctl->pages[i]);
359 unlock_page(io_ctl->pages[i]);
360 put_page(io_ctl->pages[i]);
361 }
362 }
363 }
364
365 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
366 int uptodate)
367 {
368 struct page *page;
369 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
370 int i;
371
372 for (i = 0; i < io_ctl->num_pages; i++) {
373 page = find_or_create_page(inode->i_mapping, i, mask);
374 if (!page) {
375 io_ctl_drop_pages(io_ctl);
376 return -ENOMEM;
377 }
378 io_ctl->pages[i] = page;
379 if (uptodate && !PageUptodate(page)) {
380 btrfs_readpage(NULL, page);
381 lock_page(page);
382 if (!PageUptodate(page)) {
383 btrfs_err(BTRFS_I(inode)->root->fs_info,
384 "error reading free space cache");
385 io_ctl_drop_pages(io_ctl);
386 return -EIO;
387 }
388 }
389 }
390
391 for (i = 0; i < io_ctl->num_pages; i++) {
392 clear_page_dirty_for_io(io_ctl->pages[i]);
393 set_page_extent_mapped(io_ctl->pages[i]);
394 }
395
396 return 0;
397 }
398
399 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
400 {
401 __le64 *val;
402
403 io_ctl_map_page(io_ctl, 1);
404
405 /*
406 * Skip the csum areas. If we don't check crcs then we just have a
407 * 64bit chunk at the front of the first page.
408 */
409 if (io_ctl->check_crcs) {
410 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
411 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
412 } else {
413 io_ctl->cur += sizeof(u64);
414 io_ctl->size -= sizeof(u64) * 2;
415 }
416
417 val = io_ctl->cur;
418 *val = cpu_to_le64(generation);
419 io_ctl->cur += sizeof(u64);
420 }
421
422 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
423 {
424 __le64 *gen;
425
426 /*
427 * Skip the crc area. If we don't check crcs then we just have a 64bit
428 * chunk at the front of the first page.
429 */
430 if (io_ctl->check_crcs) {
431 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
432 io_ctl->size -= sizeof(u64) +
433 (sizeof(u32) * io_ctl->num_pages);
434 } else {
435 io_ctl->cur += sizeof(u64);
436 io_ctl->size -= sizeof(u64) * 2;
437 }
438
439 gen = io_ctl->cur;
440 if (le64_to_cpu(*gen) != generation) {
441 btrfs_err_rl(io_ctl->fs_info,
442 "space cache generation (%llu) does not match inode (%llu)",
443 *gen, generation);
444 io_ctl_unmap_page(io_ctl);
445 return -EIO;
446 }
447 io_ctl->cur += sizeof(u64);
448 return 0;
449 }
450
451 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
452 {
453 u32 *tmp;
454 u32 crc = ~(u32)0;
455 unsigned offset = 0;
456
457 if (!io_ctl->check_crcs) {
458 io_ctl_unmap_page(io_ctl);
459 return;
460 }
461
462 if (index == 0)
463 offset = sizeof(u32) * io_ctl->num_pages;
464
465 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
466 PAGE_SIZE - offset);
467 btrfs_csum_final(crc, (u8 *)&crc);
468 io_ctl_unmap_page(io_ctl);
469 tmp = page_address(io_ctl->pages[0]);
470 tmp += index;
471 *tmp = crc;
472 }
473
474 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
475 {
476 u32 *tmp, val;
477 u32 crc = ~(u32)0;
478 unsigned offset = 0;
479
480 if (!io_ctl->check_crcs) {
481 io_ctl_map_page(io_ctl, 0);
482 return 0;
483 }
484
485 if (index == 0)
486 offset = sizeof(u32) * io_ctl->num_pages;
487
488 tmp = page_address(io_ctl->pages[0]);
489 tmp += index;
490 val = *tmp;
491
492 io_ctl_map_page(io_ctl, 0);
493 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
494 PAGE_SIZE - offset);
495 btrfs_csum_final(crc, (u8 *)&crc);
496 if (val != crc) {
497 btrfs_err_rl(io_ctl->fs_info,
498 "csum mismatch on free space cache");
499 io_ctl_unmap_page(io_ctl);
500 return -EIO;
501 }
502
503 return 0;
504 }
505
506 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
507 void *bitmap)
508 {
509 struct btrfs_free_space_entry *entry;
510
511 if (!io_ctl->cur)
512 return -ENOSPC;
513
514 entry = io_ctl->cur;
515 entry->offset = cpu_to_le64(offset);
516 entry->bytes = cpu_to_le64(bytes);
517 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
518 BTRFS_FREE_SPACE_EXTENT;
519 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
520 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
521
522 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
523 return 0;
524
525 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
526
527 /* No more pages to map */
528 if (io_ctl->index >= io_ctl->num_pages)
529 return 0;
530
531 /* map the next page */
532 io_ctl_map_page(io_ctl, 1);
533 return 0;
534 }
535
536 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
537 {
538 if (!io_ctl->cur)
539 return -ENOSPC;
540
541 /*
542 * If we aren't at the start of the current page, unmap this one and
543 * map the next one if there is any left.
544 */
545 if (io_ctl->cur != io_ctl->orig) {
546 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
547 if (io_ctl->index >= io_ctl->num_pages)
548 return -ENOSPC;
549 io_ctl_map_page(io_ctl, 0);
550 }
551
552 memcpy(io_ctl->cur, bitmap, PAGE_SIZE);
553 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
554 if (io_ctl->index < io_ctl->num_pages)
555 io_ctl_map_page(io_ctl, 0);
556 return 0;
557 }
558
559 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
560 {
561 /*
562 * If we're not on the boundary we know we've modified the page and we
563 * need to crc the page.
564 */
565 if (io_ctl->cur != io_ctl->orig)
566 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
567 else
568 io_ctl_unmap_page(io_ctl);
569
570 while (io_ctl->index < io_ctl->num_pages) {
571 io_ctl_map_page(io_ctl, 1);
572 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
573 }
574 }
575
576 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
577 struct btrfs_free_space *entry, u8 *type)
578 {
579 struct btrfs_free_space_entry *e;
580 int ret;
581
582 if (!io_ctl->cur) {
583 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
584 if (ret)
585 return ret;
586 }
587
588 e = io_ctl->cur;
589 entry->offset = le64_to_cpu(e->offset);
590 entry->bytes = le64_to_cpu(e->bytes);
591 *type = e->type;
592 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
593 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
594
595 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
596 return 0;
597
598 io_ctl_unmap_page(io_ctl);
599
600 return 0;
601 }
602
603 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
604 struct btrfs_free_space *entry)
605 {
606 int ret;
607
608 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
609 if (ret)
610 return ret;
611
612 memcpy(entry->bitmap, io_ctl->cur, PAGE_SIZE);
613 io_ctl_unmap_page(io_ctl);
614
615 return 0;
616 }
617
618 /*
619 * Since we attach pinned extents after the fact we can have contiguous sections
620 * of free space that are split up in entries. This poses a problem with the
621 * tree logging stuff since it could have allocated across what appears to be 2
622 * entries since we would have merged the entries when adding the pinned extents
623 * back to the free space cache. So run through the space cache that we just
624 * loaded and merge contiguous entries. This will make the log replay stuff not
625 * blow up and it will make for nicer allocator behavior.
626 */
627 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
628 {
629 struct btrfs_free_space *e, *prev = NULL;
630 struct rb_node *n;
631
632 again:
633 spin_lock(&ctl->tree_lock);
634 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
635 e = rb_entry(n, struct btrfs_free_space, offset_index);
636 if (!prev)
637 goto next;
638 if (e->bitmap || prev->bitmap)
639 goto next;
640 if (prev->offset + prev->bytes == e->offset) {
641 unlink_free_space(ctl, prev);
642 unlink_free_space(ctl, e);
643 prev->bytes += e->bytes;
644 kmem_cache_free(btrfs_free_space_cachep, e);
645 link_free_space(ctl, prev);
646 prev = NULL;
647 spin_unlock(&ctl->tree_lock);
648 goto again;
649 }
650 next:
651 prev = e;
652 }
653 spin_unlock(&ctl->tree_lock);
654 }
655
656 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
657 struct btrfs_free_space_ctl *ctl,
658 struct btrfs_path *path, u64 offset)
659 {
660 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
661 struct btrfs_free_space_header *header;
662 struct extent_buffer *leaf;
663 struct btrfs_io_ctl io_ctl;
664 struct btrfs_key key;
665 struct btrfs_free_space *e, *n;
666 LIST_HEAD(bitmaps);
667 u64 num_entries;
668 u64 num_bitmaps;
669 u64 generation;
670 u8 type;
671 int ret = 0;
672
673 /* Nothing in the space cache, goodbye */
674 if (!i_size_read(inode))
675 return 0;
676
677 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
678 key.offset = offset;
679 key.type = 0;
680
681 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
682 if (ret < 0)
683 return 0;
684 else if (ret > 0) {
685 btrfs_release_path(path);
686 return 0;
687 }
688
689 ret = -1;
690
691 leaf = path->nodes[0];
692 header = btrfs_item_ptr(leaf, path->slots[0],
693 struct btrfs_free_space_header);
694 num_entries = btrfs_free_space_entries(leaf, header);
695 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
696 generation = btrfs_free_space_generation(leaf, header);
697 btrfs_release_path(path);
698
699 if (!BTRFS_I(inode)->generation) {
700 btrfs_info(fs_info,
701 "the free space cache file (%llu) is invalid, skip it",
702 offset);
703 return 0;
704 }
705
706 if (BTRFS_I(inode)->generation != generation) {
707 btrfs_err(fs_info,
708 "free space inode generation (%llu) did not match free space cache generation (%llu)",
709 BTRFS_I(inode)->generation, generation);
710 return 0;
711 }
712
713 if (!num_entries)
714 return 0;
715
716 ret = io_ctl_init(&io_ctl, inode, 0);
717 if (ret)
718 return ret;
719
720 readahead_cache(inode);
721
722 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
723 if (ret)
724 goto out;
725
726 ret = io_ctl_check_crc(&io_ctl, 0);
727 if (ret)
728 goto free_cache;
729
730 ret = io_ctl_check_generation(&io_ctl, generation);
731 if (ret)
732 goto free_cache;
733
734 while (num_entries) {
735 e = kmem_cache_zalloc(btrfs_free_space_cachep,
736 GFP_NOFS);
737 if (!e)
738 goto free_cache;
739
740 ret = io_ctl_read_entry(&io_ctl, e, &type);
741 if (ret) {
742 kmem_cache_free(btrfs_free_space_cachep, e);
743 goto free_cache;
744 }
745
746 if (!e->bytes) {
747 kmem_cache_free(btrfs_free_space_cachep, e);
748 goto free_cache;
749 }
750
751 if (type == BTRFS_FREE_SPACE_EXTENT) {
752 spin_lock(&ctl->tree_lock);
753 ret = link_free_space(ctl, e);
754 spin_unlock(&ctl->tree_lock);
755 if (ret) {
756 btrfs_err(fs_info,
757 "Duplicate entries in free space cache, dumping");
758 kmem_cache_free(btrfs_free_space_cachep, e);
759 goto free_cache;
760 }
761 } else {
762 ASSERT(num_bitmaps);
763 num_bitmaps--;
764 e->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
765 if (!e->bitmap) {
766 kmem_cache_free(
767 btrfs_free_space_cachep, e);
768 goto free_cache;
769 }
770 spin_lock(&ctl->tree_lock);
771 ret = link_free_space(ctl, e);
772 ctl->total_bitmaps++;
773 ctl->op->recalc_thresholds(ctl);
774 spin_unlock(&ctl->tree_lock);
775 if (ret) {
776 btrfs_err(fs_info,
777 "Duplicate entries in free space cache, dumping");
778 kmem_cache_free(btrfs_free_space_cachep, e);
779 goto free_cache;
780 }
781 list_add_tail(&e->list, &bitmaps);
782 }
783
784 num_entries--;
785 }
786
787 io_ctl_unmap_page(&io_ctl);
788
789 /*
790 * We add the bitmaps at the end of the entries in order that
791 * the bitmap entries are added to the cache.
792 */
793 list_for_each_entry_safe(e, n, &bitmaps, list) {
794 list_del_init(&e->list);
795 ret = io_ctl_read_bitmap(&io_ctl, e);
796 if (ret)
797 goto free_cache;
798 }
799
800 io_ctl_drop_pages(&io_ctl);
801 merge_space_tree(ctl);
802 ret = 1;
803 out:
804 io_ctl_free(&io_ctl);
805 return ret;
806 free_cache:
807 io_ctl_drop_pages(&io_ctl);
808 __btrfs_remove_free_space_cache(ctl);
809 goto out;
810 }
811
812 int load_free_space_cache(struct btrfs_fs_info *fs_info,
813 struct btrfs_block_group_cache *block_group)
814 {
815 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
816 struct inode *inode;
817 struct btrfs_path *path;
818 int ret = 0;
819 bool matched;
820 u64 used = btrfs_block_group_used(&block_group->item);
821
822 /*
823 * If this block group has been marked to be cleared for one reason or
824 * another then we can't trust the on disk cache, so just return.
825 */
826 spin_lock(&block_group->lock);
827 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
828 spin_unlock(&block_group->lock);
829 return 0;
830 }
831 spin_unlock(&block_group->lock);
832
833 path = btrfs_alloc_path();
834 if (!path)
835 return 0;
836 path->search_commit_root = 1;
837 path->skip_locking = 1;
838
839 inode = lookup_free_space_inode(fs_info, block_group, path);
840 if (IS_ERR(inode)) {
841 btrfs_free_path(path);
842 return 0;
843 }
844
845 /* We may have converted the inode and made the cache invalid. */
846 spin_lock(&block_group->lock);
847 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
848 spin_unlock(&block_group->lock);
849 btrfs_free_path(path);
850 goto out;
851 }
852 spin_unlock(&block_group->lock);
853
854 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
855 path, block_group->key.objectid);
856 btrfs_free_path(path);
857 if (ret <= 0)
858 goto out;
859
860 spin_lock(&ctl->tree_lock);
861 matched = (ctl->free_space == (block_group->key.offset - used -
862 block_group->bytes_super));
863 spin_unlock(&ctl->tree_lock);
864
865 if (!matched) {
866 __btrfs_remove_free_space_cache(ctl);
867 btrfs_warn(fs_info,
868 "block group %llu has wrong amount of free space",
869 block_group->key.objectid);
870 ret = -1;
871 }
872 out:
873 if (ret < 0) {
874 /* This cache is bogus, make sure it gets cleared */
875 spin_lock(&block_group->lock);
876 block_group->disk_cache_state = BTRFS_DC_CLEAR;
877 spin_unlock(&block_group->lock);
878 ret = 0;
879
880 btrfs_warn(fs_info,
881 "failed to load free space cache for block group %llu, rebuilding it now",
882 block_group->key.objectid);
883 }
884
885 iput(inode);
886 return ret;
887 }
888
889 static noinline_for_stack
890 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
891 struct btrfs_free_space_ctl *ctl,
892 struct btrfs_block_group_cache *block_group,
893 int *entries, int *bitmaps,
894 struct list_head *bitmap_list)
895 {
896 int ret;
897 struct btrfs_free_cluster *cluster = NULL;
898 struct btrfs_free_cluster *cluster_locked = NULL;
899 struct rb_node *node = rb_first(&ctl->free_space_offset);
900 struct btrfs_trim_range *trim_entry;
901
902 /* Get the cluster for this block_group if it exists */
903 if (block_group && !list_empty(&block_group->cluster_list)) {
904 cluster = list_entry(block_group->cluster_list.next,
905 struct btrfs_free_cluster,
906 block_group_list);
907 }
908
909 if (!node && cluster) {
910 cluster_locked = cluster;
911 spin_lock(&cluster_locked->lock);
912 node = rb_first(&cluster->root);
913 cluster = NULL;
914 }
915
916 /* Write out the extent entries */
917 while (node) {
918 struct btrfs_free_space *e;
919
920 e = rb_entry(node, struct btrfs_free_space, offset_index);
921 *entries += 1;
922
923 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
924 e->bitmap);
925 if (ret)
926 goto fail;
927
928 if (e->bitmap) {
929 list_add_tail(&e->list, bitmap_list);
930 *bitmaps += 1;
931 }
932 node = rb_next(node);
933 if (!node && cluster) {
934 node = rb_first(&cluster->root);
935 cluster_locked = cluster;
936 spin_lock(&cluster_locked->lock);
937 cluster = NULL;
938 }
939 }
940 if (cluster_locked) {
941 spin_unlock(&cluster_locked->lock);
942 cluster_locked = NULL;
943 }
944
945 /*
946 * Make sure we don't miss any range that was removed from our rbtree
947 * because trimming is running. Otherwise after a umount+mount (or crash
948 * after committing the transaction) we would leak free space and get
949 * an inconsistent free space cache report from fsck.
950 */
951 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
952 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
953 trim_entry->bytes, NULL);
954 if (ret)
955 goto fail;
956 *entries += 1;
957 }
958
959 return 0;
960 fail:
961 if (cluster_locked)
962 spin_unlock(&cluster_locked->lock);
963 return -ENOSPC;
964 }
965
966 static noinline_for_stack int
967 update_cache_item(struct btrfs_trans_handle *trans,
968 struct btrfs_root *root,
969 struct inode *inode,
970 struct btrfs_path *path, u64 offset,
971 int entries, int bitmaps)
972 {
973 struct btrfs_key key;
974 struct btrfs_free_space_header *header;
975 struct extent_buffer *leaf;
976 int ret;
977
978 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
979 key.offset = offset;
980 key.type = 0;
981
982 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
983 if (ret < 0) {
984 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
985 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
986 goto fail;
987 }
988 leaf = path->nodes[0];
989 if (ret > 0) {
990 struct btrfs_key found_key;
991 ASSERT(path->slots[0]);
992 path->slots[0]--;
993 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
994 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
995 found_key.offset != offset) {
996 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
997 inode->i_size - 1,
998 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
999 NULL);
1000 btrfs_release_path(path);
1001 goto fail;
1002 }
1003 }
1004
1005 BTRFS_I(inode)->generation = trans->transid;
1006 header = btrfs_item_ptr(leaf, path->slots[0],
1007 struct btrfs_free_space_header);
1008 btrfs_set_free_space_entries(leaf, header, entries);
1009 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1010 btrfs_set_free_space_generation(leaf, header, trans->transid);
1011 btrfs_mark_buffer_dirty(leaf);
1012 btrfs_release_path(path);
1013
1014 return 0;
1015
1016 fail:
1017 return -1;
1018 }
1019
1020 static noinline_for_stack int
1021 write_pinned_extent_entries(struct btrfs_fs_info *fs_info,
1022 struct btrfs_block_group_cache *block_group,
1023 struct btrfs_io_ctl *io_ctl,
1024 int *entries)
1025 {
1026 u64 start, extent_start, extent_end, len;
1027 struct extent_io_tree *unpin = NULL;
1028 int ret;
1029
1030 if (!block_group)
1031 return 0;
1032
1033 /*
1034 * We want to add any pinned extents to our free space cache
1035 * so we don't leak the space
1036 *
1037 * We shouldn't have switched the pinned extents yet so this is the
1038 * right one
1039 */
1040 unpin = fs_info->pinned_extents;
1041
1042 start = block_group->key.objectid;
1043
1044 while (start < block_group->key.objectid + block_group->key.offset) {
1045 ret = find_first_extent_bit(unpin, start,
1046 &extent_start, &extent_end,
1047 EXTENT_DIRTY, NULL);
1048 if (ret)
1049 return 0;
1050
1051 /* This pinned extent is out of our range */
1052 if (extent_start >= block_group->key.objectid +
1053 block_group->key.offset)
1054 return 0;
1055
1056 extent_start = max(extent_start, start);
1057 extent_end = min(block_group->key.objectid +
1058 block_group->key.offset, extent_end + 1);
1059 len = extent_end - extent_start;
1060
1061 *entries += 1;
1062 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1063 if (ret)
1064 return -ENOSPC;
1065
1066 start = extent_end;
1067 }
1068
1069 return 0;
1070 }
1071
1072 static noinline_for_stack int
1073 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1074 {
1075 struct btrfs_free_space *entry, *next;
1076 int ret;
1077
1078 /* Write out the bitmaps */
1079 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1080 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1081 if (ret)
1082 return -ENOSPC;
1083 list_del_init(&entry->list);
1084 }
1085
1086 return 0;
1087 }
1088
1089 static int flush_dirty_cache(struct inode *inode)
1090 {
1091 int ret;
1092
1093 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1094 if (ret)
1095 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1096 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
1097
1098 return ret;
1099 }
1100
1101 static void noinline_for_stack
1102 cleanup_bitmap_list(struct list_head *bitmap_list)
1103 {
1104 struct btrfs_free_space *entry, *next;
1105
1106 list_for_each_entry_safe(entry, next, bitmap_list, list)
1107 list_del_init(&entry->list);
1108 }
1109
1110 static void noinline_for_stack
1111 cleanup_write_cache_enospc(struct inode *inode,
1112 struct btrfs_io_ctl *io_ctl,
1113 struct extent_state **cached_state)
1114 {
1115 io_ctl_drop_pages(io_ctl);
1116 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1117 i_size_read(inode) - 1, cached_state);
1118 }
1119
1120 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1121 struct btrfs_trans_handle *trans,
1122 struct btrfs_block_group_cache *block_group,
1123 struct btrfs_io_ctl *io_ctl,
1124 struct btrfs_path *path, u64 offset)
1125 {
1126 int ret;
1127 struct inode *inode = io_ctl->inode;
1128 struct btrfs_fs_info *fs_info;
1129
1130 if (!inode)
1131 return 0;
1132
1133 fs_info = btrfs_sb(inode->i_sb);
1134
1135 /* Flush the dirty pages in the cache file. */
1136 ret = flush_dirty_cache(inode);
1137 if (ret)
1138 goto out;
1139
1140 /* Update the cache item to tell everyone this cache file is valid. */
1141 ret = update_cache_item(trans, root, inode, path, offset,
1142 io_ctl->entries, io_ctl->bitmaps);
1143 out:
1144 io_ctl_free(io_ctl);
1145 if (ret) {
1146 invalidate_inode_pages2(inode->i_mapping);
1147 BTRFS_I(inode)->generation = 0;
1148 if (block_group) {
1149 #ifdef DEBUG
1150 btrfs_err(fs_info,
1151 "failed to write free space cache for block group %llu",
1152 block_group->key.objectid);
1153 #endif
1154 }
1155 }
1156 btrfs_update_inode(trans, root, inode);
1157
1158 if (block_group) {
1159 /* the dirty list is protected by the dirty_bgs_lock */
1160 spin_lock(&trans->transaction->dirty_bgs_lock);
1161
1162 /* the disk_cache_state is protected by the block group lock */
1163 spin_lock(&block_group->lock);
1164
1165 /*
1166 * only mark this as written if we didn't get put back on
1167 * the dirty list while waiting for IO. Otherwise our
1168 * cache state won't be right, and we won't get written again
1169 */
1170 if (!ret && list_empty(&block_group->dirty_list))
1171 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1172 else if (ret)
1173 block_group->disk_cache_state = BTRFS_DC_ERROR;
1174
1175 spin_unlock(&block_group->lock);
1176 spin_unlock(&trans->transaction->dirty_bgs_lock);
1177 io_ctl->inode = NULL;
1178 iput(inode);
1179 }
1180
1181 return ret;
1182
1183 }
1184
1185 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
1186 struct btrfs_trans_handle *trans,
1187 struct btrfs_io_ctl *io_ctl,
1188 struct btrfs_path *path)
1189 {
1190 return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
1191 }
1192
1193 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1194 struct btrfs_block_group_cache *block_group,
1195 struct btrfs_path *path)
1196 {
1197 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1198 block_group, &block_group->io_ctl,
1199 path, block_group->key.objectid);
1200 }
1201
1202 /**
1203 * __btrfs_write_out_cache - write out cached info to an inode
1204 * @root - the root the inode belongs to
1205 * @ctl - the free space cache we are going to write out
1206 * @block_group - the block_group for this cache if it belongs to a block_group
1207 * @trans - the trans handle
1208 *
1209 * This function writes out a free space cache struct to disk for quick recovery
1210 * on mount. This will return 0 if it was successful in writing the cache out,
1211 * or an errno if it was not.
1212 */
1213 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1214 struct btrfs_free_space_ctl *ctl,
1215 struct btrfs_block_group_cache *block_group,
1216 struct btrfs_io_ctl *io_ctl,
1217 struct btrfs_trans_handle *trans)
1218 {
1219 struct btrfs_fs_info *fs_info = root->fs_info;
1220 struct extent_state *cached_state = NULL;
1221 LIST_HEAD(bitmap_list);
1222 int entries = 0;
1223 int bitmaps = 0;
1224 int ret;
1225 int must_iput = 0;
1226
1227 if (!i_size_read(inode))
1228 return -EIO;
1229
1230 WARN_ON(io_ctl->pages);
1231 ret = io_ctl_init(io_ctl, inode, 1);
1232 if (ret)
1233 return ret;
1234
1235 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1236 down_write(&block_group->data_rwsem);
1237 spin_lock(&block_group->lock);
1238 if (block_group->delalloc_bytes) {
1239 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1240 spin_unlock(&block_group->lock);
1241 up_write(&block_group->data_rwsem);
1242 BTRFS_I(inode)->generation = 0;
1243 ret = 0;
1244 must_iput = 1;
1245 goto out;
1246 }
1247 spin_unlock(&block_group->lock);
1248 }
1249
1250 /* Lock all pages first so we can lock the extent safely. */
1251 ret = io_ctl_prepare_pages(io_ctl, inode, 0);
1252 if (ret)
1253 goto out_unlock;
1254
1255 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1256 &cached_state);
1257
1258 io_ctl_set_generation(io_ctl, trans->transid);
1259
1260 mutex_lock(&ctl->cache_writeout_mutex);
1261 /* Write out the extent entries in the free space cache */
1262 spin_lock(&ctl->tree_lock);
1263 ret = write_cache_extent_entries(io_ctl, ctl,
1264 block_group, &entries, &bitmaps,
1265 &bitmap_list);
1266 if (ret)
1267 goto out_nospc_locked;
1268
1269 /*
1270 * Some spaces that are freed in the current transaction are pinned,
1271 * they will be added into free space cache after the transaction is
1272 * committed, we shouldn't lose them.
1273 *
1274 * If this changes while we are working we'll get added back to
1275 * the dirty list and redo it. No locking needed
1276 */
1277 ret = write_pinned_extent_entries(fs_info, block_group,
1278 io_ctl, &entries);
1279 if (ret)
1280 goto out_nospc_locked;
1281
1282 /*
1283 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1284 * locked while doing it because a concurrent trim can be manipulating
1285 * or freeing the bitmap.
1286 */
1287 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1288 spin_unlock(&ctl->tree_lock);
1289 mutex_unlock(&ctl->cache_writeout_mutex);
1290 if (ret)
1291 goto out_nospc;
1292
1293 /* Zero out the rest of the pages just to make sure */
1294 io_ctl_zero_remaining_pages(io_ctl);
1295
1296 /* Everything is written out, now we dirty the pages in the file. */
1297 ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
1298 i_size_read(inode), &cached_state);
1299 if (ret)
1300 goto out_nospc;
1301
1302 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1303 up_write(&block_group->data_rwsem);
1304 /*
1305 * Release the pages and unlock the extent, we will flush
1306 * them out later
1307 */
1308 io_ctl_drop_pages(io_ctl);
1309
1310 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1311 i_size_read(inode) - 1, &cached_state);
1312
1313 /*
1314 * at this point the pages are under IO and we're happy,
1315 * The caller is responsible for waiting on them and updating the
1316 * the cache and the inode
1317 */
1318 io_ctl->entries = entries;
1319 io_ctl->bitmaps = bitmaps;
1320
1321 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1322 if (ret)
1323 goto out;
1324
1325 return 0;
1326
1327 out:
1328 io_ctl->inode = NULL;
1329 io_ctl_free(io_ctl);
1330 if (ret) {
1331 invalidate_inode_pages2(inode->i_mapping);
1332 BTRFS_I(inode)->generation = 0;
1333 }
1334 btrfs_update_inode(trans, root, inode);
1335 if (must_iput)
1336 iput(inode);
1337 return ret;
1338
1339 out_nospc_locked:
1340 cleanup_bitmap_list(&bitmap_list);
1341 spin_unlock(&ctl->tree_lock);
1342 mutex_unlock(&ctl->cache_writeout_mutex);
1343
1344 out_nospc:
1345 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1346
1347 out_unlock:
1348 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1349 up_write(&block_group->data_rwsem);
1350
1351 goto out;
1352 }
1353
1354 int btrfs_write_out_cache(struct btrfs_fs_info *fs_info,
1355 struct btrfs_trans_handle *trans,
1356 struct btrfs_block_group_cache *block_group,
1357 struct btrfs_path *path)
1358 {
1359 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1360 struct inode *inode;
1361 int ret = 0;
1362
1363 spin_lock(&block_group->lock);
1364 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1365 spin_unlock(&block_group->lock);
1366 return 0;
1367 }
1368 spin_unlock(&block_group->lock);
1369
1370 inode = lookup_free_space_inode(fs_info, block_group, path);
1371 if (IS_ERR(inode))
1372 return 0;
1373
1374 ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
1375 block_group, &block_group->io_ctl, trans);
1376 if (ret) {
1377 #ifdef DEBUG
1378 btrfs_err(fs_info,
1379 "failed to write free space cache for block group %llu",
1380 block_group->key.objectid);
1381 #endif
1382 spin_lock(&block_group->lock);
1383 block_group->disk_cache_state = BTRFS_DC_ERROR;
1384 spin_unlock(&block_group->lock);
1385
1386 block_group->io_ctl.inode = NULL;
1387 iput(inode);
1388 }
1389
1390 /*
1391 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1392 * to wait for IO and put the inode
1393 */
1394
1395 return ret;
1396 }
1397
1398 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1399 u64 offset)
1400 {
1401 ASSERT(offset >= bitmap_start);
1402 offset -= bitmap_start;
1403 return (unsigned long)(div_u64(offset, unit));
1404 }
1405
1406 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1407 {
1408 return (unsigned long)(div_u64(bytes, unit));
1409 }
1410
1411 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1412 u64 offset)
1413 {
1414 u64 bitmap_start;
1415 u64 bytes_per_bitmap;
1416
1417 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1418 bitmap_start = offset - ctl->start;
1419 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1420 bitmap_start *= bytes_per_bitmap;
1421 bitmap_start += ctl->start;
1422
1423 return bitmap_start;
1424 }
1425
1426 static int tree_insert_offset(struct rb_root *root, u64 offset,
1427 struct rb_node *node, int bitmap)
1428 {
1429 struct rb_node **p = &root->rb_node;
1430 struct rb_node *parent = NULL;
1431 struct btrfs_free_space *info;
1432
1433 while (*p) {
1434 parent = *p;
1435 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1436
1437 if (offset < info->offset) {
1438 p = &(*p)->rb_left;
1439 } else if (offset > info->offset) {
1440 p = &(*p)->rb_right;
1441 } else {
1442 /*
1443 * we could have a bitmap entry and an extent entry
1444 * share the same offset. If this is the case, we want
1445 * the extent entry to always be found first if we do a
1446 * linear search through the tree, since we want to have
1447 * the quickest allocation time, and allocating from an
1448 * extent is faster than allocating from a bitmap. So
1449 * if we're inserting a bitmap and we find an entry at
1450 * this offset, we want to go right, or after this entry
1451 * logically. If we are inserting an extent and we've
1452 * found a bitmap, we want to go left, or before
1453 * logically.
1454 */
1455 if (bitmap) {
1456 if (info->bitmap) {
1457 WARN_ON_ONCE(1);
1458 return -EEXIST;
1459 }
1460 p = &(*p)->rb_right;
1461 } else {
1462 if (!info->bitmap) {
1463 WARN_ON_ONCE(1);
1464 return -EEXIST;
1465 }
1466 p = &(*p)->rb_left;
1467 }
1468 }
1469 }
1470
1471 rb_link_node(node, parent, p);
1472 rb_insert_color(node, root);
1473
1474 return 0;
1475 }
1476
1477 /*
1478 * searches the tree for the given offset.
1479 *
1480 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1481 * want a section that has at least bytes size and comes at or after the given
1482 * offset.
1483 */
1484 static struct btrfs_free_space *
1485 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1486 u64 offset, int bitmap_only, int fuzzy)
1487 {
1488 struct rb_node *n = ctl->free_space_offset.rb_node;
1489 struct btrfs_free_space *entry, *prev = NULL;
1490
1491 /* find entry that is closest to the 'offset' */
1492 while (1) {
1493 if (!n) {
1494 entry = NULL;
1495 break;
1496 }
1497
1498 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1499 prev = entry;
1500
1501 if (offset < entry->offset)
1502 n = n->rb_left;
1503 else if (offset > entry->offset)
1504 n = n->rb_right;
1505 else
1506 break;
1507 }
1508
1509 if (bitmap_only) {
1510 if (!entry)
1511 return NULL;
1512 if (entry->bitmap)
1513 return entry;
1514
1515 /*
1516 * bitmap entry and extent entry may share same offset,
1517 * in that case, bitmap entry comes after extent entry.
1518 */
1519 n = rb_next(n);
1520 if (!n)
1521 return NULL;
1522 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1523 if (entry->offset != offset)
1524 return NULL;
1525
1526 WARN_ON(!entry->bitmap);
1527 return entry;
1528 } else if (entry) {
1529 if (entry->bitmap) {
1530 /*
1531 * if previous extent entry covers the offset,
1532 * we should return it instead of the bitmap entry
1533 */
1534 n = rb_prev(&entry->offset_index);
1535 if (n) {
1536 prev = rb_entry(n, struct btrfs_free_space,
1537 offset_index);
1538 if (!prev->bitmap &&
1539 prev->offset + prev->bytes > offset)
1540 entry = prev;
1541 }
1542 }
1543 return entry;
1544 }
1545
1546 if (!prev)
1547 return NULL;
1548
1549 /* find last entry before the 'offset' */
1550 entry = prev;
1551 if (entry->offset > offset) {
1552 n = rb_prev(&entry->offset_index);
1553 if (n) {
1554 entry = rb_entry(n, struct btrfs_free_space,
1555 offset_index);
1556 ASSERT(entry->offset <= offset);
1557 } else {
1558 if (fuzzy)
1559 return entry;
1560 else
1561 return NULL;
1562 }
1563 }
1564
1565 if (entry->bitmap) {
1566 n = rb_prev(&entry->offset_index);
1567 if (n) {
1568 prev = rb_entry(n, struct btrfs_free_space,
1569 offset_index);
1570 if (!prev->bitmap &&
1571 prev->offset + prev->bytes > offset)
1572 return prev;
1573 }
1574 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1575 return entry;
1576 } else if (entry->offset + entry->bytes > offset)
1577 return entry;
1578
1579 if (!fuzzy)
1580 return NULL;
1581
1582 while (1) {
1583 if (entry->bitmap) {
1584 if (entry->offset + BITS_PER_BITMAP *
1585 ctl->unit > offset)
1586 break;
1587 } else {
1588 if (entry->offset + entry->bytes > offset)
1589 break;
1590 }
1591
1592 n = rb_next(&entry->offset_index);
1593 if (!n)
1594 return NULL;
1595 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1596 }
1597 return entry;
1598 }
1599
1600 static inline void
1601 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1602 struct btrfs_free_space *info)
1603 {
1604 rb_erase(&info->offset_index, &ctl->free_space_offset);
1605 ctl->free_extents--;
1606 }
1607
1608 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1609 struct btrfs_free_space *info)
1610 {
1611 __unlink_free_space(ctl, info);
1612 ctl->free_space -= info->bytes;
1613 }
1614
1615 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1616 struct btrfs_free_space *info)
1617 {
1618 int ret = 0;
1619
1620 ASSERT(info->bytes || info->bitmap);
1621 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1622 &info->offset_index, (info->bitmap != NULL));
1623 if (ret)
1624 return ret;
1625
1626 ctl->free_space += info->bytes;
1627 ctl->free_extents++;
1628 return ret;
1629 }
1630
1631 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1632 {
1633 struct btrfs_block_group_cache *block_group = ctl->private;
1634 u64 max_bytes;
1635 u64 bitmap_bytes;
1636 u64 extent_bytes;
1637 u64 size = block_group->key.offset;
1638 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1639 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1640
1641 max_bitmaps = max_t(u64, max_bitmaps, 1);
1642
1643 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1644
1645 /*
1646 * The goal is to keep the total amount of memory used per 1gb of space
1647 * at or below 32k, so we need to adjust how much memory we allow to be
1648 * used by extent based free space tracking
1649 */
1650 if (size < SZ_1G)
1651 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1652 else
1653 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1654
1655 /*
1656 * we want to account for 1 more bitmap than what we have so we can make
1657 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1658 * we add more bitmaps.
1659 */
1660 bitmap_bytes = (ctl->total_bitmaps + 1) * ctl->unit;
1661
1662 if (bitmap_bytes >= max_bytes) {
1663 ctl->extents_thresh = 0;
1664 return;
1665 }
1666
1667 /*
1668 * we want the extent entry threshold to always be at most 1/2 the max
1669 * bytes we can have, or whatever is less than that.
1670 */
1671 extent_bytes = max_bytes - bitmap_bytes;
1672 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1673
1674 ctl->extents_thresh =
1675 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1676 }
1677
1678 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1679 struct btrfs_free_space *info,
1680 u64 offset, u64 bytes)
1681 {
1682 unsigned long start, count;
1683
1684 start = offset_to_bit(info->offset, ctl->unit, offset);
1685 count = bytes_to_bits(bytes, ctl->unit);
1686 ASSERT(start + count <= BITS_PER_BITMAP);
1687
1688 bitmap_clear(info->bitmap, start, count);
1689
1690 info->bytes -= bytes;
1691 }
1692
1693 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1694 struct btrfs_free_space *info, u64 offset,
1695 u64 bytes)
1696 {
1697 __bitmap_clear_bits(ctl, info, offset, bytes);
1698 ctl->free_space -= bytes;
1699 }
1700
1701 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1702 struct btrfs_free_space *info, u64 offset,
1703 u64 bytes)
1704 {
1705 unsigned long start, count;
1706
1707 start = offset_to_bit(info->offset, ctl->unit, offset);
1708 count = bytes_to_bits(bytes, ctl->unit);
1709 ASSERT(start + count <= BITS_PER_BITMAP);
1710
1711 bitmap_set(info->bitmap, start, count);
1712
1713 info->bytes += bytes;
1714 ctl->free_space += bytes;
1715 }
1716
1717 /*
1718 * If we can not find suitable extent, we will use bytes to record
1719 * the size of the max extent.
1720 */
1721 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1722 struct btrfs_free_space *bitmap_info, u64 *offset,
1723 u64 *bytes, bool for_alloc)
1724 {
1725 unsigned long found_bits = 0;
1726 unsigned long max_bits = 0;
1727 unsigned long bits, i;
1728 unsigned long next_zero;
1729 unsigned long extent_bits;
1730
1731 /*
1732 * Skip searching the bitmap if we don't have a contiguous section that
1733 * is large enough for this allocation.
1734 */
1735 if (for_alloc &&
1736 bitmap_info->max_extent_size &&
1737 bitmap_info->max_extent_size < *bytes) {
1738 *bytes = bitmap_info->max_extent_size;
1739 return -1;
1740 }
1741
1742 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1743 max_t(u64, *offset, bitmap_info->offset));
1744 bits = bytes_to_bits(*bytes, ctl->unit);
1745
1746 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1747 if (for_alloc && bits == 1) {
1748 found_bits = 1;
1749 break;
1750 }
1751 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1752 BITS_PER_BITMAP, i);
1753 extent_bits = next_zero - i;
1754 if (extent_bits >= bits) {
1755 found_bits = extent_bits;
1756 break;
1757 } else if (extent_bits > max_bits) {
1758 max_bits = extent_bits;
1759 }
1760 i = next_zero;
1761 }
1762
1763 if (found_bits) {
1764 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1765 *bytes = (u64)(found_bits) * ctl->unit;
1766 return 0;
1767 }
1768
1769 *bytes = (u64)(max_bits) * ctl->unit;
1770 bitmap_info->max_extent_size = *bytes;
1771 return -1;
1772 }
1773
1774 /* Cache the size of the max extent in bytes */
1775 static struct btrfs_free_space *
1776 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1777 unsigned long align, u64 *max_extent_size)
1778 {
1779 struct btrfs_free_space *entry;
1780 struct rb_node *node;
1781 u64 tmp;
1782 u64 align_off;
1783 int ret;
1784
1785 if (!ctl->free_space_offset.rb_node)
1786 goto out;
1787
1788 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1789 if (!entry)
1790 goto out;
1791
1792 for (node = &entry->offset_index; node; node = rb_next(node)) {
1793 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1794 if (entry->bytes < *bytes) {
1795 if (entry->bytes > *max_extent_size)
1796 *max_extent_size = entry->bytes;
1797 continue;
1798 }
1799
1800 /* make sure the space returned is big enough
1801 * to match our requested alignment
1802 */
1803 if (*bytes >= align) {
1804 tmp = entry->offset - ctl->start + align - 1;
1805 tmp = div64_u64(tmp, align);
1806 tmp = tmp * align + ctl->start;
1807 align_off = tmp - entry->offset;
1808 } else {
1809 align_off = 0;
1810 tmp = entry->offset;
1811 }
1812
1813 if (entry->bytes < *bytes + align_off) {
1814 if (entry->bytes > *max_extent_size)
1815 *max_extent_size = entry->bytes;
1816 continue;
1817 }
1818
1819 if (entry->bitmap) {
1820 u64 size = *bytes;
1821
1822 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1823 if (!ret) {
1824 *offset = tmp;
1825 *bytes = size;
1826 return entry;
1827 } else if (size > *max_extent_size) {
1828 *max_extent_size = size;
1829 }
1830 continue;
1831 }
1832
1833 *offset = tmp;
1834 *bytes = entry->bytes - align_off;
1835 return entry;
1836 }
1837 out:
1838 return NULL;
1839 }
1840
1841 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1842 struct btrfs_free_space *info, u64 offset)
1843 {
1844 info->offset = offset_to_bitmap(ctl, offset);
1845 info->bytes = 0;
1846 INIT_LIST_HEAD(&info->list);
1847 link_free_space(ctl, info);
1848 ctl->total_bitmaps++;
1849
1850 ctl->op->recalc_thresholds(ctl);
1851 }
1852
1853 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1854 struct btrfs_free_space *bitmap_info)
1855 {
1856 unlink_free_space(ctl, bitmap_info);
1857 kfree(bitmap_info->bitmap);
1858 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1859 ctl->total_bitmaps--;
1860 ctl->op->recalc_thresholds(ctl);
1861 }
1862
1863 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1864 struct btrfs_free_space *bitmap_info,
1865 u64 *offset, u64 *bytes)
1866 {
1867 u64 end;
1868 u64 search_start, search_bytes;
1869 int ret;
1870
1871 again:
1872 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1873
1874 /*
1875 * We need to search for bits in this bitmap. We could only cover some
1876 * of the extent in this bitmap thanks to how we add space, so we need
1877 * to search for as much as it as we can and clear that amount, and then
1878 * go searching for the next bit.
1879 */
1880 search_start = *offset;
1881 search_bytes = ctl->unit;
1882 search_bytes = min(search_bytes, end - search_start + 1);
1883 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1884 false);
1885 if (ret < 0 || search_start != *offset)
1886 return -EINVAL;
1887
1888 /* We may have found more bits than what we need */
1889 search_bytes = min(search_bytes, *bytes);
1890
1891 /* Cannot clear past the end of the bitmap */
1892 search_bytes = min(search_bytes, end - search_start + 1);
1893
1894 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1895 *offset += search_bytes;
1896 *bytes -= search_bytes;
1897
1898 if (*bytes) {
1899 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1900 if (!bitmap_info->bytes)
1901 free_bitmap(ctl, bitmap_info);
1902
1903 /*
1904 * no entry after this bitmap, but we still have bytes to
1905 * remove, so something has gone wrong.
1906 */
1907 if (!next)
1908 return -EINVAL;
1909
1910 bitmap_info = rb_entry(next, struct btrfs_free_space,
1911 offset_index);
1912
1913 /*
1914 * if the next entry isn't a bitmap we need to return to let the
1915 * extent stuff do its work.
1916 */
1917 if (!bitmap_info->bitmap)
1918 return -EAGAIN;
1919
1920 /*
1921 * Ok the next item is a bitmap, but it may not actually hold
1922 * the information for the rest of this free space stuff, so
1923 * look for it, and if we don't find it return so we can try
1924 * everything over again.
1925 */
1926 search_start = *offset;
1927 search_bytes = ctl->unit;
1928 ret = search_bitmap(ctl, bitmap_info, &search_start,
1929 &search_bytes, false);
1930 if (ret < 0 || search_start != *offset)
1931 return -EAGAIN;
1932
1933 goto again;
1934 } else if (!bitmap_info->bytes)
1935 free_bitmap(ctl, bitmap_info);
1936
1937 return 0;
1938 }
1939
1940 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1941 struct btrfs_free_space *info, u64 offset,
1942 u64 bytes)
1943 {
1944 u64 bytes_to_set = 0;
1945 u64 end;
1946
1947 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1948
1949 bytes_to_set = min(end - offset, bytes);
1950
1951 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1952
1953 /*
1954 * We set some bytes, we have no idea what the max extent size is
1955 * anymore.
1956 */
1957 info->max_extent_size = 0;
1958
1959 return bytes_to_set;
1960
1961 }
1962
1963 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1964 struct btrfs_free_space *info)
1965 {
1966 struct btrfs_block_group_cache *block_group = ctl->private;
1967 struct btrfs_fs_info *fs_info = block_group->fs_info;
1968 bool forced = false;
1969
1970 #ifdef CONFIG_BTRFS_DEBUG
1971 if (btrfs_should_fragment_free_space(block_group))
1972 forced = true;
1973 #endif
1974
1975 /*
1976 * If we are below the extents threshold then we can add this as an
1977 * extent, and don't have to deal with the bitmap
1978 */
1979 if (!forced && ctl->free_extents < ctl->extents_thresh) {
1980 /*
1981 * If this block group has some small extents we don't want to
1982 * use up all of our free slots in the cache with them, we want
1983 * to reserve them to larger extents, however if we have plenty
1984 * of cache left then go ahead an dadd them, no sense in adding
1985 * the overhead of a bitmap if we don't have to.
1986 */
1987 if (info->bytes <= fs_info->sectorsize * 4) {
1988 if (ctl->free_extents * 2 <= ctl->extents_thresh)
1989 return false;
1990 } else {
1991 return false;
1992 }
1993 }
1994
1995 /*
1996 * The original block groups from mkfs can be really small, like 8
1997 * megabytes, so don't bother with a bitmap for those entries. However
1998 * some block groups can be smaller than what a bitmap would cover but
1999 * are still large enough that they could overflow the 32k memory limit,
2000 * so allow those block groups to still be allowed to have a bitmap
2001 * entry.
2002 */
2003 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
2004 return false;
2005
2006 return true;
2007 }
2008
2009 static const struct btrfs_free_space_op free_space_op = {
2010 .recalc_thresholds = recalculate_thresholds,
2011 .use_bitmap = use_bitmap,
2012 };
2013
2014 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2015 struct btrfs_free_space *info)
2016 {
2017 struct btrfs_free_space *bitmap_info;
2018 struct btrfs_block_group_cache *block_group = NULL;
2019 int added = 0;
2020 u64 bytes, offset, bytes_added;
2021 int ret;
2022
2023 bytes = info->bytes;
2024 offset = info->offset;
2025
2026 if (!ctl->op->use_bitmap(ctl, info))
2027 return 0;
2028
2029 if (ctl->op == &free_space_op)
2030 block_group = ctl->private;
2031 again:
2032 /*
2033 * Since we link bitmaps right into the cluster we need to see if we
2034 * have a cluster here, and if so and it has our bitmap we need to add
2035 * the free space to that bitmap.
2036 */
2037 if (block_group && !list_empty(&block_group->cluster_list)) {
2038 struct btrfs_free_cluster *cluster;
2039 struct rb_node *node;
2040 struct btrfs_free_space *entry;
2041
2042 cluster = list_entry(block_group->cluster_list.next,
2043 struct btrfs_free_cluster,
2044 block_group_list);
2045 spin_lock(&cluster->lock);
2046 node = rb_first(&cluster->root);
2047 if (!node) {
2048 spin_unlock(&cluster->lock);
2049 goto no_cluster_bitmap;
2050 }
2051
2052 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2053 if (!entry->bitmap) {
2054 spin_unlock(&cluster->lock);
2055 goto no_cluster_bitmap;
2056 }
2057
2058 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2059 bytes_added = add_bytes_to_bitmap(ctl, entry,
2060 offset, bytes);
2061 bytes -= bytes_added;
2062 offset += bytes_added;
2063 }
2064 spin_unlock(&cluster->lock);
2065 if (!bytes) {
2066 ret = 1;
2067 goto out;
2068 }
2069 }
2070
2071 no_cluster_bitmap:
2072 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2073 1, 0);
2074 if (!bitmap_info) {
2075 ASSERT(added == 0);
2076 goto new_bitmap;
2077 }
2078
2079 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
2080 bytes -= bytes_added;
2081 offset += bytes_added;
2082 added = 0;
2083
2084 if (!bytes) {
2085 ret = 1;
2086 goto out;
2087 } else
2088 goto again;
2089
2090 new_bitmap:
2091 if (info && info->bitmap) {
2092 add_new_bitmap(ctl, info, offset);
2093 added = 1;
2094 info = NULL;
2095 goto again;
2096 } else {
2097 spin_unlock(&ctl->tree_lock);
2098
2099 /* no pre-allocated info, allocate a new one */
2100 if (!info) {
2101 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2102 GFP_NOFS);
2103 if (!info) {
2104 spin_lock(&ctl->tree_lock);
2105 ret = -ENOMEM;
2106 goto out;
2107 }
2108 }
2109
2110 /* allocate the bitmap */
2111 info->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
2112 spin_lock(&ctl->tree_lock);
2113 if (!info->bitmap) {
2114 ret = -ENOMEM;
2115 goto out;
2116 }
2117 goto again;
2118 }
2119
2120 out:
2121 if (info) {
2122 if (info->bitmap)
2123 kfree(info->bitmap);
2124 kmem_cache_free(btrfs_free_space_cachep, info);
2125 }
2126
2127 return ret;
2128 }
2129
2130 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2131 struct btrfs_free_space *info, bool update_stat)
2132 {
2133 struct btrfs_free_space *left_info;
2134 struct btrfs_free_space *right_info;
2135 bool merged = false;
2136 u64 offset = info->offset;
2137 u64 bytes = info->bytes;
2138
2139 /*
2140 * first we want to see if there is free space adjacent to the range we
2141 * are adding, if there is remove that struct and add a new one to
2142 * cover the entire range
2143 */
2144 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2145 if (right_info && rb_prev(&right_info->offset_index))
2146 left_info = rb_entry(rb_prev(&right_info->offset_index),
2147 struct btrfs_free_space, offset_index);
2148 else
2149 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2150
2151 if (right_info && !right_info->bitmap) {
2152 if (update_stat)
2153 unlink_free_space(ctl, right_info);
2154 else
2155 __unlink_free_space(ctl, right_info);
2156 info->bytes += right_info->bytes;
2157 kmem_cache_free(btrfs_free_space_cachep, right_info);
2158 merged = true;
2159 }
2160
2161 if (left_info && !left_info->bitmap &&
2162 left_info->offset + left_info->bytes == offset) {
2163 if (update_stat)
2164 unlink_free_space(ctl, left_info);
2165 else
2166 __unlink_free_space(ctl, left_info);
2167 info->offset = left_info->offset;
2168 info->bytes += left_info->bytes;
2169 kmem_cache_free(btrfs_free_space_cachep, left_info);
2170 merged = true;
2171 }
2172
2173 return merged;
2174 }
2175
2176 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2177 struct btrfs_free_space *info,
2178 bool update_stat)
2179 {
2180 struct btrfs_free_space *bitmap;
2181 unsigned long i;
2182 unsigned long j;
2183 const u64 end = info->offset + info->bytes;
2184 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2185 u64 bytes;
2186
2187 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2188 if (!bitmap)
2189 return false;
2190
2191 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2192 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2193 if (j == i)
2194 return false;
2195 bytes = (j - i) * ctl->unit;
2196 info->bytes += bytes;
2197
2198 if (update_stat)
2199 bitmap_clear_bits(ctl, bitmap, end, bytes);
2200 else
2201 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2202
2203 if (!bitmap->bytes)
2204 free_bitmap(ctl, bitmap);
2205
2206 return true;
2207 }
2208
2209 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2210 struct btrfs_free_space *info,
2211 bool update_stat)
2212 {
2213 struct btrfs_free_space *bitmap;
2214 u64 bitmap_offset;
2215 unsigned long i;
2216 unsigned long j;
2217 unsigned long prev_j;
2218 u64 bytes;
2219
2220 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2221 /* If we're on a boundary, try the previous logical bitmap. */
2222 if (bitmap_offset == info->offset) {
2223 if (info->offset == 0)
2224 return false;
2225 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2226 }
2227
2228 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2229 if (!bitmap)
2230 return false;
2231
2232 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2233 j = 0;
2234 prev_j = (unsigned long)-1;
2235 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2236 if (j > i)
2237 break;
2238 prev_j = j;
2239 }
2240 if (prev_j == i)
2241 return false;
2242
2243 if (prev_j == (unsigned long)-1)
2244 bytes = (i + 1) * ctl->unit;
2245 else
2246 bytes = (i - prev_j) * ctl->unit;
2247
2248 info->offset -= bytes;
2249 info->bytes += bytes;
2250
2251 if (update_stat)
2252 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2253 else
2254 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2255
2256 if (!bitmap->bytes)
2257 free_bitmap(ctl, bitmap);
2258
2259 return true;
2260 }
2261
2262 /*
2263 * We prefer always to allocate from extent entries, both for clustered and
2264 * non-clustered allocation requests. So when attempting to add a new extent
2265 * entry, try to see if there's adjacent free space in bitmap entries, and if
2266 * there is, migrate that space from the bitmaps to the extent.
2267 * Like this we get better chances of satisfying space allocation requests
2268 * because we attempt to satisfy them based on a single cache entry, and never
2269 * on 2 or more entries - even if the entries represent a contiguous free space
2270 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2271 * ends).
2272 */
2273 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2274 struct btrfs_free_space *info,
2275 bool update_stat)
2276 {
2277 /*
2278 * Only work with disconnected entries, as we can change their offset,
2279 * and must be extent entries.
2280 */
2281 ASSERT(!info->bitmap);
2282 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2283
2284 if (ctl->total_bitmaps > 0) {
2285 bool stole_end;
2286 bool stole_front = false;
2287
2288 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2289 if (ctl->total_bitmaps > 0)
2290 stole_front = steal_from_bitmap_to_front(ctl, info,
2291 update_stat);
2292
2293 if (stole_end || stole_front)
2294 try_merge_free_space(ctl, info, update_stat);
2295 }
2296 }
2297
2298 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
2299 struct btrfs_free_space_ctl *ctl,
2300 u64 offset, u64 bytes)
2301 {
2302 struct btrfs_free_space *info;
2303 int ret = 0;
2304
2305 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2306 if (!info)
2307 return -ENOMEM;
2308
2309 info->offset = offset;
2310 info->bytes = bytes;
2311 RB_CLEAR_NODE(&info->offset_index);
2312
2313 spin_lock(&ctl->tree_lock);
2314
2315 if (try_merge_free_space(ctl, info, true))
2316 goto link;
2317
2318 /*
2319 * There was no extent directly to the left or right of this new
2320 * extent then we know we're going to have to allocate a new extent, so
2321 * before we do that see if we need to drop this into a bitmap
2322 */
2323 ret = insert_into_bitmap(ctl, info);
2324 if (ret < 0) {
2325 goto out;
2326 } else if (ret) {
2327 ret = 0;
2328 goto out;
2329 }
2330 link:
2331 /*
2332 * Only steal free space from adjacent bitmaps if we're sure we're not
2333 * going to add the new free space to existing bitmap entries - because
2334 * that would mean unnecessary work that would be reverted. Therefore
2335 * attempt to steal space from bitmaps if we're adding an extent entry.
2336 */
2337 steal_from_bitmap(ctl, info, true);
2338
2339 ret = link_free_space(ctl, info);
2340 if (ret)
2341 kmem_cache_free(btrfs_free_space_cachep, info);
2342 out:
2343 spin_unlock(&ctl->tree_lock);
2344
2345 if (ret) {
2346 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2347 ASSERT(ret != -EEXIST);
2348 }
2349
2350 return ret;
2351 }
2352
2353 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2354 u64 offset, u64 bytes)
2355 {
2356 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2357 struct btrfs_free_space *info;
2358 int ret;
2359 bool re_search = false;
2360
2361 spin_lock(&ctl->tree_lock);
2362
2363 again:
2364 ret = 0;
2365 if (!bytes)
2366 goto out_lock;
2367
2368 info = tree_search_offset(ctl, offset, 0, 0);
2369 if (!info) {
2370 /*
2371 * oops didn't find an extent that matched the space we wanted
2372 * to remove, look for a bitmap instead
2373 */
2374 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2375 1, 0);
2376 if (!info) {
2377 /*
2378 * If we found a partial bit of our free space in a
2379 * bitmap but then couldn't find the other part this may
2380 * be a problem, so WARN about it.
2381 */
2382 WARN_ON(re_search);
2383 goto out_lock;
2384 }
2385 }
2386
2387 re_search = false;
2388 if (!info->bitmap) {
2389 unlink_free_space(ctl, info);
2390 if (offset == info->offset) {
2391 u64 to_free = min(bytes, info->bytes);
2392
2393 info->bytes -= to_free;
2394 info->offset += to_free;
2395 if (info->bytes) {
2396 ret = link_free_space(ctl, info);
2397 WARN_ON(ret);
2398 } else {
2399 kmem_cache_free(btrfs_free_space_cachep, info);
2400 }
2401
2402 offset += to_free;
2403 bytes -= to_free;
2404 goto again;
2405 } else {
2406 u64 old_end = info->bytes + info->offset;
2407
2408 info->bytes = offset - info->offset;
2409 ret = link_free_space(ctl, info);
2410 WARN_ON(ret);
2411 if (ret)
2412 goto out_lock;
2413
2414 /* Not enough bytes in this entry to satisfy us */
2415 if (old_end < offset + bytes) {
2416 bytes -= old_end - offset;
2417 offset = old_end;
2418 goto again;
2419 } else if (old_end == offset + bytes) {
2420 /* all done */
2421 goto out_lock;
2422 }
2423 spin_unlock(&ctl->tree_lock);
2424
2425 ret = btrfs_add_free_space(block_group, offset + bytes,
2426 old_end - (offset + bytes));
2427 WARN_ON(ret);
2428 goto out;
2429 }
2430 }
2431
2432 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2433 if (ret == -EAGAIN) {
2434 re_search = true;
2435 goto again;
2436 }
2437 out_lock:
2438 spin_unlock(&ctl->tree_lock);
2439 out:
2440 return ret;
2441 }
2442
2443 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2444 u64 bytes)
2445 {
2446 struct btrfs_fs_info *fs_info = block_group->fs_info;
2447 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2448 struct btrfs_free_space *info;
2449 struct rb_node *n;
2450 int count = 0;
2451
2452 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2453 info = rb_entry(n, struct btrfs_free_space, offset_index);
2454 if (info->bytes >= bytes && !block_group->ro)
2455 count++;
2456 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2457 info->offset, info->bytes,
2458 (info->bitmap) ? "yes" : "no");
2459 }
2460 btrfs_info(fs_info, "block group has cluster?: %s",
2461 list_empty(&block_group->cluster_list) ? "no" : "yes");
2462 btrfs_info(fs_info,
2463 "%d blocks of free space at or bigger than bytes is", count);
2464 }
2465
2466 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2467 {
2468 struct btrfs_fs_info *fs_info = block_group->fs_info;
2469 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2470
2471 spin_lock_init(&ctl->tree_lock);
2472 ctl->unit = fs_info->sectorsize;
2473 ctl->start = block_group->key.objectid;
2474 ctl->private = block_group;
2475 ctl->op = &free_space_op;
2476 INIT_LIST_HEAD(&ctl->trimming_ranges);
2477 mutex_init(&ctl->cache_writeout_mutex);
2478
2479 /*
2480 * we only want to have 32k of ram per block group for keeping
2481 * track of free space, and if we pass 1/2 of that we want to
2482 * start converting things over to using bitmaps
2483 */
2484 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2485 }
2486
2487 /*
2488 * for a given cluster, put all of its extents back into the free
2489 * space cache. If the block group passed doesn't match the block group
2490 * pointed to by the cluster, someone else raced in and freed the
2491 * cluster already. In that case, we just return without changing anything
2492 */
2493 static int
2494 __btrfs_return_cluster_to_free_space(
2495 struct btrfs_block_group_cache *block_group,
2496 struct btrfs_free_cluster *cluster)
2497 {
2498 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2499 struct btrfs_free_space *entry;
2500 struct rb_node *node;
2501
2502 spin_lock(&cluster->lock);
2503 if (cluster->block_group != block_group)
2504 goto out;
2505
2506 cluster->block_group = NULL;
2507 cluster->window_start = 0;
2508 list_del_init(&cluster->block_group_list);
2509
2510 node = rb_first(&cluster->root);
2511 while (node) {
2512 bool bitmap;
2513
2514 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2515 node = rb_next(&entry->offset_index);
2516 rb_erase(&entry->offset_index, &cluster->root);
2517 RB_CLEAR_NODE(&entry->offset_index);
2518
2519 bitmap = (entry->bitmap != NULL);
2520 if (!bitmap) {
2521 try_merge_free_space(ctl, entry, false);
2522 steal_from_bitmap(ctl, entry, false);
2523 }
2524 tree_insert_offset(&ctl->free_space_offset,
2525 entry->offset, &entry->offset_index, bitmap);
2526 }
2527 cluster->root = RB_ROOT;
2528
2529 out:
2530 spin_unlock(&cluster->lock);
2531 btrfs_put_block_group(block_group);
2532 return 0;
2533 }
2534
2535 static void __btrfs_remove_free_space_cache_locked(
2536 struct btrfs_free_space_ctl *ctl)
2537 {
2538 struct btrfs_free_space *info;
2539 struct rb_node *node;
2540
2541 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2542 info = rb_entry(node, struct btrfs_free_space, offset_index);
2543 if (!info->bitmap) {
2544 unlink_free_space(ctl, info);
2545 kmem_cache_free(btrfs_free_space_cachep, info);
2546 } else {
2547 free_bitmap(ctl, info);
2548 }
2549
2550 cond_resched_lock(&ctl->tree_lock);
2551 }
2552 }
2553
2554 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2555 {
2556 spin_lock(&ctl->tree_lock);
2557 __btrfs_remove_free_space_cache_locked(ctl);
2558 spin_unlock(&ctl->tree_lock);
2559 }
2560
2561 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2562 {
2563 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2564 struct btrfs_free_cluster *cluster;
2565 struct list_head *head;
2566
2567 spin_lock(&ctl->tree_lock);
2568 while ((head = block_group->cluster_list.next) !=
2569 &block_group->cluster_list) {
2570 cluster = list_entry(head, struct btrfs_free_cluster,
2571 block_group_list);
2572
2573 WARN_ON(cluster->block_group != block_group);
2574 __btrfs_return_cluster_to_free_space(block_group, cluster);
2575
2576 cond_resched_lock(&ctl->tree_lock);
2577 }
2578 __btrfs_remove_free_space_cache_locked(ctl);
2579 spin_unlock(&ctl->tree_lock);
2580
2581 }
2582
2583 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2584 u64 offset, u64 bytes, u64 empty_size,
2585 u64 *max_extent_size)
2586 {
2587 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2588 struct btrfs_free_space *entry = NULL;
2589 u64 bytes_search = bytes + empty_size;
2590 u64 ret = 0;
2591 u64 align_gap = 0;
2592 u64 align_gap_len = 0;
2593
2594 spin_lock(&ctl->tree_lock);
2595 entry = find_free_space(ctl, &offset, &bytes_search,
2596 block_group->full_stripe_len, max_extent_size);
2597 if (!entry)
2598 goto out;
2599
2600 ret = offset;
2601 if (entry->bitmap) {
2602 bitmap_clear_bits(ctl, entry, offset, bytes);
2603 if (!entry->bytes)
2604 free_bitmap(ctl, entry);
2605 } else {
2606 unlink_free_space(ctl, entry);
2607 align_gap_len = offset - entry->offset;
2608 align_gap = entry->offset;
2609
2610 entry->offset = offset + bytes;
2611 WARN_ON(entry->bytes < bytes + align_gap_len);
2612
2613 entry->bytes -= bytes + align_gap_len;
2614 if (!entry->bytes)
2615 kmem_cache_free(btrfs_free_space_cachep, entry);
2616 else
2617 link_free_space(ctl, entry);
2618 }
2619 out:
2620 spin_unlock(&ctl->tree_lock);
2621
2622 if (align_gap_len)
2623 __btrfs_add_free_space(block_group->fs_info, ctl,
2624 align_gap, align_gap_len);
2625 return ret;
2626 }
2627
2628 /*
2629 * given a cluster, put all of its extents back into the free space
2630 * cache. If a block group is passed, this function will only free
2631 * a cluster that belongs to the passed block group.
2632 *
2633 * Otherwise, it'll get a reference on the block group pointed to by the
2634 * cluster and remove the cluster from it.
2635 */
2636 int btrfs_return_cluster_to_free_space(
2637 struct btrfs_block_group_cache *block_group,
2638 struct btrfs_free_cluster *cluster)
2639 {
2640 struct btrfs_free_space_ctl *ctl;
2641 int ret;
2642
2643 /* first, get a safe pointer to the block group */
2644 spin_lock(&cluster->lock);
2645 if (!block_group) {
2646 block_group = cluster->block_group;
2647 if (!block_group) {
2648 spin_unlock(&cluster->lock);
2649 return 0;
2650 }
2651 } else if (cluster->block_group != block_group) {
2652 /* someone else has already freed it don't redo their work */
2653 spin_unlock(&cluster->lock);
2654 return 0;
2655 }
2656 atomic_inc(&block_group->count);
2657 spin_unlock(&cluster->lock);
2658
2659 ctl = block_group->free_space_ctl;
2660
2661 /* now return any extents the cluster had on it */
2662 spin_lock(&ctl->tree_lock);
2663 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2664 spin_unlock(&ctl->tree_lock);
2665
2666 /* finally drop our ref */
2667 btrfs_put_block_group(block_group);
2668 return ret;
2669 }
2670
2671 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2672 struct btrfs_free_cluster *cluster,
2673 struct btrfs_free_space *entry,
2674 u64 bytes, u64 min_start,
2675 u64 *max_extent_size)
2676 {
2677 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2678 int err;
2679 u64 search_start = cluster->window_start;
2680 u64 search_bytes = bytes;
2681 u64 ret = 0;
2682
2683 search_start = min_start;
2684 search_bytes = bytes;
2685
2686 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2687 if (err) {
2688 if (search_bytes > *max_extent_size)
2689 *max_extent_size = search_bytes;
2690 return 0;
2691 }
2692
2693 ret = search_start;
2694 __bitmap_clear_bits(ctl, entry, ret, bytes);
2695
2696 return ret;
2697 }
2698
2699 /*
2700 * given a cluster, try to allocate 'bytes' from it, returns 0
2701 * if it couldn't find anything suitably large, or a logical disk offset
2702 * if things worked out
2703 */
2704 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2705 struct btrfs_free_cluster *cluster, u64 bytes,
2706 u64 min_start, u64 *max_extent_size)
2707 {
2708 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2709 struct btrfs_free_space *entry = NULL;
2710 struct rb_node *node;
2711 u64 ret = 0;
2712
2713 spin_lock(&cluster->lock);
2714 if (bytes > cluster->max_size)
2715 goto out;
2716
2717 if (cluster->block_group != block_group)
2718 goto out;
2719
2720 node = rb_first(&cluster->root);
2721 if (!node)
2722 goto out;
2723
2724 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2725 while (1) {
2726 if (entry->bytes < bytes && entry->bytes > *max_extent_size)
2727 *max_extent_size = entry->bytes;
2728
2729 if (entry->bytes < bytes ||
2730 (!entry->bitmap && entry->offset < min_start)) {
2731 node = rb_next(&entry->offset_index);
2732 if (!node)
2733 break;
2734 entry = rb_entry(node, struct btrfs_free_space,
2735 offset_index);
2736 continue;
2737 }
2738
2739 if (entry->bitmap) {
2740 ret = btrfs_alloc_from_bitmap(block_group,
2741 cluster, entry, bytes,
2742 cluster->window_start,
2743 max_extent_size);
2744 if (ret == 0) {
2745 node = rb_next(&entry->offset_index);
2746 if (!node)
2747 break;
2748 entry = rb_entry(node, struct btrfs_free_space,
2749 offset_index);
2750 continue;
2751 }
2752 cluster->window_start += bytes;
2753 } else {
2754 ret = entry->offset;
2755
2756 entry->offset += bytes;
2757 entry->bytes -= bytes;
2758 }
2759
2760 if (entry->bytes == 0)
2761 rb_erase(&entry->offset_index, &cluster->root);
2762 break;
2763 }
2764 out:
2765 spin_unlock(&cluster->lock);
2766
2767 if (!ret)
2768 return 0;
2769
2770 spin_lock(&ctl->tree_lock);
2771
2772 ctl->free_space -= bytes;
2773 if (entry->bytes == 0) {
2774 ctl->free_extents--;
2775 if (entry->bitmap) {
2776 kfree(entry->bitmap);
2777 ctl->total_bitmaps--;
2778 ctl->op->recalc_thresholds(ctl);
2779 }
2780 kmem_cache_free(btrfs_free_space_cachep, entry);
2781 }
2782
2783 spin_unlock(&ctl->tree_lock);
2784
2785 return ret;
2786 }
2787
2788 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2789 struct btrfs_free_space *entry,
2790 struct btrfs_free_cluster *cluster,
2791 u64 offset, u64 bytes,
2792 u64 cont1_bytes, u64 min_bytes)
2793 {
2794 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2795 unsigned long next_zero;
2796 unsigned long i;
2797 unsigned long want_bits;
2798 unsigned long min_bits;
2799 unsigned long found_bits;
2800 unsigned long max_bits = 0;
2801 unsigned long start = 0;
2802 unsigned long total_found = 0;
2803 int ret;
2804
2805 i = offset_to_bit(entry->offset, ctl->unit,
2806 max_t(u64, offset, entry->offset));
2807 want_bits = bytes_to_bits(bytes, ctl->unit);
2808 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2809
2810 /*
2811 * Don't bother looking for a cluster in this bitmap if it's heavily
2812 * fragmented.
2813 */
2814 if (entry->max_extent_size &&
2815 entry->max_extent_size < cont1_bytes)
2816 return -ENOSPC;
2817 again:
2818 found_bits = 0;
2819 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2820 next_zero = find_next_zero_bit(entry->bitmap,
2821 BITS_PER_BITMAP, i);
2822 if (next_zero - i >= min_bits) {
2823 found_bits = next_zero - i;
2824 if (found_bits > max_bits)
2825 max_bits = found_bits;
2826 break;
2827 }
2828 if (next_zero - i > max_bits)
2829 max_bits = next_zero - i;
2830 i = next_zero;
2831 }
2832
2833 if (!found_bits) {
2834 entry->max_extent_size = (u64)max_bits * ctl->unit;
2835 return -ENOSPC;
2836 }
2837
2838 if (!total_found) {
2839 start = i;
2840 cluster->max_size = 0;
2841 }
2842
2843 total_found += found_bits;
2844
2845 if (cluster->max_size < found_bits * ctl->unit)
2846 cluster->max_size = found_bits * ctl->unit;
2847
2848 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2849 i = next_zero + 1;
2850 goto again;
2851 }
2852
2853 cluster->window_start = start * ctl->unit + entry->offset;
2854 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2855 ret = tree_insert_offset(&cluster->root, entry->offset,
2856 &entry->offset_index, 1);
2857 ASSERT(!ret); /* -EEXIST; Logic error */
2858
2859 trace_btrfs_setup_cluster(block_group, cluster,
2860 total_found * ctl->unit, 1);
2861 return 0;
2862 }
2863
2864 /*
2865 * This searches the block group for just extents to fill the cluster with.
2866 * Try to find a cluster with at least bytes total bytes, at least one
2867 * extent of cont1_bytes, and other clusters of at least min_bytes.
2868 */
2869 static noinline int
2870 setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2871 struct btrfs_free_cluster *cluster,
2872 struct list_head *bitmaps, u64 offset, u64 bytes,
2873 u64 cont1_bytes, u64 min_bytes)
2874 {
2875 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2876 struct btrfs_free_space *first = NULL;
2877 struct btrfs_free_space *entry = NULL;
2878 struct btrfs_free_space *last;
2879 struct rb_node *node;
2880 u64 window_free;
2881 u64 max_extent;
2882 u64 total_size = 0;
2883
2884 entry = tree_search_offset(ctl, offset, 0, 1);
2885 if (!entry)
2886 return -ENOSPC;
2887
2888 /*
2889 * We don't want bitmaps, so just move along until we find a normal
2890 * extent entry.
2891 */
2892 while (entry->bitmap || entry->bytes < min_bytes) {
2893 if (entry->bitmap && list_empty(&entry->list))
2894 list_add_tail(&entry->list, bitmaps);
2895 node = rb_next(&entry->offset_index);
2896 if (!node)
2897 return -ENOSPC;
2898 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2899 }
2900
2901 window_free = entry->bytes;
2902 max_extent = entry->bytes;
2903 first = entry;
2904 last = entry;
2905
2906 for (node = rb_next(&entry->offset_index); node;
2907 node = rb_next(&entry->offset_index)) {
2908 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2909
2910 if (entry->bitmap) {
2911 if (list_empty(&entry->list))
2912 list_add_tail(&entry->list, bitmaps);
2913 continue;
2914 }
2915
2916 if (entry->bytes < min_bytes)
2917 continue;
2918
2919 last = entry;
2920 window_free += entry->bytes;
2921 if (entry->bytes > max_extent)
2922 max_extent = entry->bytes;
2923 }
2924
2925 if (window_free < bytes || max_extent < cont1_bytes)
2926 return -ENOSPC;
2927
2928 cluster->window_start = first->offset;
2929
2930 node = &first->offset_index;
2931
2932 /*
2933 * now we've found our entries, pull them out of the free space
2934 * cache and put them into the cluster rbtree
2935 */
2936 do {
2937 int ret;
2938
2939 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2940 node = rb_next(&entry->offset_index);
2941 if (entry->bitmap || entry->bytes < min_bytes)
2942 continue;
2943
2944 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2945 ret = tree_insert_offset(&cluster->root, entry->offset,
2946 &entry->offset_index, 0);
2947 total_size += entry->bytes;
2948 ASSERT(!ret); /* -EEXIST; Logic error */
2949 } while (node && entry != last);
2950
2951 cluster->max_size = max_extent;
2952 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2953 return 0;
2954 }
2955
2956 /*
2957 * This specifically looks for bitmaps that may work in the cluster, we assume
2958 * that we have already failed to find extents that will work.
2959 */
2960 static noinline int
2961 setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
2962 struct btrfs_free_cluster *cluster,
2963 struct list_head *bitmaps, u64 offset, u64 bytes,
2964 u64 cont1_bytes, u64 min_bytes)
2965 {
2966 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2967 struct btrfs_free_space *entry = NULL;
2968 int ret = -ENOSPC;
2969 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
2970
2971 if (ctl->total_bitmaps == 0)
2972 return -ENOSPC;
2973
2974 /*
2975 * The bitmap that covers offset won't be in the list unless offset
2976 * is just its start offset.
2977 */
2978 if (!list_empty(bitmaps))
2979 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
2980
2981 if (!entry || entry->offset != bitmap_offset) {
2982 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
2983 if (entry && list_empty(&entry->list))
2984 list_add(&entry->list, bitmaps);
2985 }
2986
2987 list_for_each_entry(entry, bitmaps, list) {
2988 if (entry->bytes < bytes)
2989 continue;
2990 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
2991 bytes, cont1_bytes, min_bytes);
2992 if (!ret)
2993 return 0;
2994 }
2995
2996 /*
2997 * The bitmaps list has all the bitmaps that record free space
2998 * starting after offset, so no more search is required.
2999 */
3000 return -ENOSPC;
3001 }
3002
3003 /*
3004 * here we try to find a cluster of blocks in a block group. The goal
3005 * is to find at least bytes+empty_size.
3006 * We might not find them all in one contiguous area.
3007 *
3008 * returns zero and sets up cluster if things worked out, otherwise
3009 * it returns -enospc
3010 */
3011 int btrfs_find_space_cluster(struct btrfs_fs_info *fs_info,
3012 struct btrfs_block_group_cache *block_group,
3013 struct btrfs_free_cluster *cluster,
3014 u64 offset, u64 bytes, u64 empty_size)
3015 {
3016 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3017 struct btrfs_free_space *entry, *tmp;
3018 LIST_HEAD(bitmaps);
3019 u64 min_bytes;
3020 u64 cont1_bytes;
3021 int ret;
3022
3023 /*
3024 * Choose the minimum extent size we'll require for this
3025 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3026 * For metadata, allow allocates with smaller extents. For
3027 * data, keep it dense.
3028 */
3029 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3030 cont1_bytes = min_bytes = bytes + empty_size;
3031 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3032 cont1_bytes = bytes;
3033 min_bytes = fs_info->sectorsize;
3034 } else {
3035 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3036 min_bytes = fs_info->sectorsize;
3037 }
3038
3039 spin_lock(&ctl->tree_lock);
3040
3041 /*
3042 * If we know we don't have enough space to make a cluster don't even
3043 * bother doing all the work to try and find one.
3044 */
3045 if (ctl->free_space < bytes) {
3046 spin_unlock(&ctl->tree_lock);
3047 return -ENOSPC;
3048 }
3049
3050 spin_lock(&cluster->lock);
3051
3052 /* someone already found a cluster, hooray */
3053 if (cluster->block_group) {
3054 ret = 0;
3055 goto out;
3056 }
3057
3058 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3059 min_bytes);
3060
3061 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3062 bytes + empty_size,
3063 cont1_bytes, min_bytes);
3064 if (ret)
3065 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3066 offset, bytes + empty_size,
3067 cont1_bytes, min_bytes);
3068
3069 /* Clear our temporary list */
3070 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3071 list_del_init(&entry->list);
3072
3073 if (!ret) {
3074 atomic_inc(&block_group->count);
3075 list_add_tail(&cluster->block_group_list,
3076 &block_group->cluster_list);
3077 cluster->block_group = block_group;
3078 } else {
3079 trace_btrfs_failed_cluster_setup(block_group);
3080 }
3081 out:
3082 spin_unlock(&cluster->lock);
3083 spin_unlock(&ctl->tree_lock);
3084
3085 return ret;
3086 }
3087
3088 /*
3089 * simple code to zero out a cluster
3090 */
3091 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3092 {
3093 spin_lock_init(&cluster->lock);
3094 spin_lock_init(&cluster->refill_lock);
3095 cluster->root = RB_ROOT;
3096 cluster->max_size = 0;
3097 cluster->fragmented = false;
3098 INIT_LIST_HEAD(&cluster->block_group_list);
3099 cluster->block_group = NULL;
3100 }
3101
3102 static int do_trimming(struct btrfs_block_group_cache *block_group,
3103 u64 *total_trimmed, u64 start, u64 bytes,
3104 u64 reserved_start, u64 reserved_bytes,
3105 struct btrfs_trim_range *trim_entry)
3106 {
3107 struct btrfs_space_info *space_info = block_group->space_info;
3108 struct btrfs_fs_info *fs_info = block_group->fs_info;
3109 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3110 int ret;
3111 int update = 0;
3112 u64 trimmed = 0;
3113
3114 spin_lock(&space_info->lock);
3115 spin_lock(&block_group->lock);
3116 if (!block_group->ro) {
3117 block_group->reserved += reserved_bytes;
3118 space_info->bytes_reserved += reserved_bytes;
3119 update = 1;
3120 }
3121 spin_unlock(&block_group->lock);
3122 spin_unlock(&space_info->lock);
3123
3124 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3125 if (!ret)
3126 *total_trimmed += trimmed;
3127
3128 mutex_lock(&ctl->cache_writeout_mutex);
3129 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
3130 list_del(&trim_entry->list);
3131 mutex_unlock(&ctl->cache_writeout_mutex);
3132
3133 if (update) {
3134 spin_lock(&space_info->lock);
3135 spin_lock(&block_group->lock);
3136 if (block_group->ro)
3137 space_info->bytes_readonly += reserved_bytes;
3138 block_group->reserved -= reserved_bytes;
3139 space_info->bytes_reserved -= reserved_bytes;
3140 spin_unlock(&space_info->lock);
3141 spin_unlock(&block_group->lock);
3142 }
3143
3144 return ret;
3145 }
3146
3147 static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
3148 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3149 {
3150 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3151 struct btrfs_free_space *entry;
3152 struct rb_node *node;
3153 int ret = 0;
3154 u64 extent_start;
3155 u64 extent_bytes;
3156 u64 bytes;
3157
3158 while (start < end) {
3159 struct btrfs_trim_range trim_entry;
3160
3161 mutex_lock(&ctl->cache_writeout_mutex);
3162 spin_lock(&ctl->tree_lock);
3163
3164 if (ctl->free_space < minlen) {
3165 spin_unlock(&ctl->tree_lock);
3166 mutex_unlock(&ctl->cache_writeout_mutex);
3167 break;
3168 }
3169
3170 entry = tree_search_offset(ctl, start, 0, 1);
3171 if (!entry) {
3172 spin_unlock(&ctl->tree_lock);
3173 mutex_unlock(&ctl->cache_writeout_mutex);
3174 break;
3175 }
3176
3177 /* skip bitmaps */
3178 while (entry->bitmap) {
3179 node = rb_next(&entry->offset_index);
3180 if (!node) {
3181 spin_unlock(&ctl->tree_lock);
3182 mutex_unlock(&ctl->cache_writeout_mutex);
3183 goto out;
3184 }
3185 entry = rb_entry(node, struct btrfs_free_space,
3186 offset_index);
3187 }
3188
3189 if (entry->offset >= end) {
3190 spin_unlock(&ctl->tree_lock);
3191 mutex_unlock(&ctl->cache_writeout_mutex);
3192 break;
3193 }
3194
3195 extent_start = entry->offset;
3196 extent_bytes = entry->bytes;
3197 start = max(start, extent_start);
3198 bytes = min(extent_start + extent_bytes, end) - start;
3199 if (bytes < minlen) {
3200 spin_unlock(&ctl->tree_lock);
3201 mutex_unlock(&ctl->cache_writeout_mutex);
3202 goto next;
3203 }
3204
3205 unlink_free_space(ctl, entry);
3206 kmem_cache_free(btrfs_free_space_cachep, entry);
3207
3208 spin_unlock(&ctl->tree_lock);
3209 trim_entry.start = extent_start;
3210 trim_entry.bytes = extent_bytes;
3211 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3212 mutex_unlock(&ctl->cache_writeout_mutex);
3213
3214 ret = do_trimming(block_group, total_trimmed, start, bytes,
3215 extent_start, extent_bytes, &trim_entry);
3216 if (ret)
3217 break;
3218 next:
3219 start += bytes;
3220
3221 if (fatal_signal_pending(current)) {
3222 ret = -ERESTARTSYS;
3223 break;
3224 }
3225
3226 cond_resched();
3227 }
3228 out:
3229 return ret;
3230 }
3231
3232 static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
3233 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3234 {
3235 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3236 struct btrfs_free_space *entry;
3237 int ret = 0;
3238 int ret2;
3239 u64 bytes;
3240 u64 offset = offset_to_bitmap(ctl, start);
3241
3242 while (offset < end) {
3243 bool next_bitmap = false;
3244 struct btrfs_trim_range trim_entry;
3245
3246 mutex_lock(&ctl->cache_writeout_mutex);
3247 spin_lock(&ctl->tree_lock);
3248
3249 if (ctl->free_space < minlen) {
3250 spin_unlock(&ctl->tree_lock);
3251 mutex_unlock(&ctl->cache_writeout_mutex);
3252 break;
3253 }
3254
3255 entry = tree_search_offset(ctl, offset, 1, 0);
3256 if (!entry) {
3257 spin_unlock(&ctl->tree_lock);
3258 mutex_unlock(&ctl->cache_writeout_mutex);
3259 next_bitmap = true;
3260 goto next;
3261 }
3262
3263 bytes = minlen;
3264 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3265 if (ret2 || start >= end) {
3266 spin_unlock(&ctl->tree_lock);
3267 mutex_unlock(&ctl->cache_writeout_mutex);
3268 next_bitmap = true;
3269 goto next;
3270 }
3271
3272 bytes = min(bytes, end - start);
3273 if (bytes < minlen) {
3274 spin_unlock(&ctl->tree_lock);
3275 mutex_unlock(&ctl->cache_writeout_mutex);
3276 goto next;
3277 }
3278
3279 bitmap_clear_bits(ctl, entry, start, bytes);
3280 if (entry->bytes == 0)
3281 free_bitmap(ctl, entry);
3282
3283 spin_unlock(&ctl->tree_lock);
3284 trim_entry.start = start;
3285 trim_entry.bytes = bytes;
3286 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3287 mutex_unlock(&ctl->cache_writeout_mutex);
3288
3289 ret = do_trimming(block_group, total_trimmed, start, bytes,
3290 start, bytes, &trim_entry);
3291 if (ret)
3292 break;
3293 next:
3294 if (next_bitmap) {
3295 offset += BITS_PER_BITMAP * ctl->unit;
3296 } else {
3297 start += bytes;
3298 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
3299 offset += BITS_PER_BITMAP * ctl->unit;
3300 }
3301
3302 if (fatal_signal_pending(current)) {
3303 ret = -ERESTARTSYS;
3304 break;
3305 }
3306
3307 cond_resched();
3308 }
3309
3310 return ret;
3311 }
3312
3313 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
3314 {
3315 atomic_inc(&cache->trimming);
3316 }
3317
3318 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
3319 {
3320 struct btrfs_fs_info *fs_info = block_group->fs_info;
3321 struct extent_map_tree *em_tree;
3322 struct extent_map *em;
3323 bool cleanup;
3324
3325 spin_lock(&block_group->lock);
3326 cleanup = (atomic_dec_and_test(&block_group->trimming) &&
3327 block_group->removed);
3328 spin_unlock(&block_group->lock);
3329
3330 if (cleanup) {
3331 mutex_lock(&fs_info->chunk_mutex);
3332 em_tree = &fs_info->mapping_tree.map_tree;
3333 write_lock(&em_tree->lock);
3334 em = lookup_extent_mapping(em_tree, block_group->key.objectid,
3335 1);
3336 BUG_ON(!em); /* logic error, can't happen */
3337 /*
3338 * remove_extent_mapping() will delete us from the pinned_chunks
3339 * list, which is protected by the chunk mutex.
3340 */
3341 remove_extent_mapping(em_tree, em);
3342 write_unlock(&em_tree->lock);
3343 mutex_unlock(&fs_info->chunk_mutex);
3344
3345 /* once for us and once for the tree */
3346 free_extent_map(em);
3347 free_extent_map(em);
3348
3349 /*
3350 * We've left one free space entry and other tasks trimming
3351 * this block group have left 1 entry each one. Free them.
3352 */
3353 __btrfs_remove_free_space_cache(block_group->free_space_ctl);
3354 }
3355 }
3356
3357 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
3358 u64 *trimmed, u64 start, u64 end, u64 minlen)
3359 {
3360 int ret;
3361
3362 *trimmed = 0;
3363
3364 spin_lock(&block_group->lock);
3365 if (block_group->removed) {
3366 spin_unlock(&block_group->lock);
3367 return 0;
3368 }
3369 btrfs_get_block_group_trimming(block_group);
3370 spin_unlock(&block_group->lock);
3371
3372 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
3373 if (ret)
3374 goto out;
3375
3376 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
3377 out:
3378 btrfs_put_block_group_trimming(block_group);
3379 return ret;
3380 }
3381
3382 /*
3383 * Find the left-most item in the cache tree, and then return the
3384 * smallest inode number in the item.
3385 *
3386 * Note: the returned inode number may not be the smallest one in
3387 * the tree, if the left-most item is a bitmap.
3388 */
3389 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3390 {
3391 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3392 struct btrfs_free_space *entry = NULL;
3393 u64 ino = 0;
3394
3395 spin_lock(&ctl->tree_lock);
3396
3397 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3398 goto out;
3399
3400 entry = rb_entry(rb_first(&ctl->free_space_offset),
3401 struct btrfs_free_space, offset_index);
3402
3403 if (!entry->bitmap) {
3404 ino = entry->offset;
3405
3406 unlink_free_space(ctl, entry);
3407 entry->offset++;
3408 entry->bytes--;
3409 if (!entry->bytes)
3410 kmem_cache_free(btrfs_free_space_cachep, entry);
3411 else
3412 link_free_space(ctl, entry);
3413 } else {
3414 u64 offset = 0;
3415 u64 count = 1;
3416 int ret;
3417
3418 ret = search_bitmap(ctl, entry, &offset, &count, true);
3419 /* Logic error; Should be empty if it can't find anything */
3420 ASSERT(!ret);
3421
3422 ino = offset;
3423 bitmap_clear_bits(ctl, entry, offset, 1);
3424 if (entry->bytes == 0)
3425 free_bitmap(ctl, entry);
3426 }
3427 out:
3428 spin_unlock(&ctl->tree_lock);
3429
3430 return ino;
3431 }
3432
3433 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3434 struct btrfs_path *path)
3435 {
3436 struct inode *inode = NULL;
3437
3438 spin_lock(&root->ino_cache_lock);
3439 if (root->ino_cache_inode)
3440 inode = igrab(root->ino_cache_inode);
3441 spin_unlock(&root->ino_cache_lock);
3442 if (inode)
3443 return inode;
3444
3445 inode = __lookup_free_space_inode(root, path, 0);
3446 if (IS_ERR(inode))
3447 return inode;
3448
3449 spin_lock(&root->ino_cache_lock);
3450 if (!btrfs_fs_closing(root->fs_info))
3451 root->ino_cache_inode = igrab(inode);
3452 spin_unlock(&root->ino_cache_lock);
3453
3454 return inode;
3455 }
3456
3457 int create_free_ino_inode(struct btrfs_root *root,
3458 struct btrfs_trans_handle *trans,
3459 struct btrfs_path *path)
3460 {
3461 return __create_free_space_inode(root, trans, path,
3462 BTRFS_FREE_INO_OBJECTID, 0);
3463 }
3464
3465 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3466 {
3467 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3468 struct btrfs_path *path;
3469 struct inode *inode;
3470 int ret = 0;
3471 u64 root_gen = btrfs_root_generation(&root->root_item);
3472
3473 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3474 return 0;
3475
3476 /*
3477 * If we're unmounting then just return, since this does a search on the
3478 * normal root and not the commit root and we could deadlock.
3479 */
3480 if (btrfs_fs_closing(fs_info))
3481 return 0;
3482
3483 path = btrfs_alloc_path();
3484 if (!path)
3485 return 0;
3486
3487 inode = lookup_free_ino_inode(root, path);
3488 if (IS_ERR(inode))
3489 goto out;
3490
3491 if (root_gen != BTRFS_I(inode)->generation)
3492 goto out_put;
3493
3494 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3495
3496 if (ret < 0)
3497 btrfs_err(fs_info,
3498 "failed to load free ino cache for root %llu",
3499 root->root_key.objectid);
3500 out_put:
3501 iput(inode);
3502 out:
3503 btrfs_free_path(path);
3504 return ret;
3505 }
3506
3507 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3508 struct btrfs_trans_handle *trans,
3509 struct btrfs_path *path,
3510 struct inode *inode)
3511 {
3512 struct btrfs_fs_info *fs_info = root->fs_info;
3513 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3514 int ret;
3515 struct btrfs_io_ctl io_ctl;
3516 bool release_metadata = true;
3517
3518 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3519 return 0;
3520
3521 memset(&io_ctl, 0, sizeof(io_ctl));
3522 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
3523 if (!ret) {
3524 /*
3525 * At this point writepages() didn't error out, so our metadata
3526 * reservation is released when the writeback finishes, at
3527 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3528 * with or without an error.
3529 */
3530 release_metadata = false;
3531 ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
3532 }
3533
3534 if (ret) {
3535 if (release_metadata)
3536 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3537 inode->i_size, true);
3538 #ifdef DEBUG
3539 btrfs_err(fs_info,
3540 "failed to write free ino cache for root %llu",
3541 root->root_key.objectid);
3542 #endif
3543 }
3544
3545 return ret;
3546 }
3547
3548 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3549 /*
3550 * Use this if you need to make a bitmap or extent entry specifically, it
3551 * doesn't do any of the merging that add_free_space does, this acts a lot like
3552 * how the free space cache loading stuff works, so you can get really weird
3553 * configurations.
3554 */
3555 int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3556 u64 offset, u64 bytes, bool bitmap)
3557 {
3558 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3559 struct btrfs_free_space *info = NULL, *bitmap_info;
3560 void *map = NULL;
3561 u64 bytes_added;
3562 int ret;
3563
3564 again:
3565 if (!info) {
3566 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3567 if (!info)
3568 return -ENOMEM;
3569 }
3570
3571 if (!bitmap) {
3572 spin_lock(&ctl->tree_lock);
3573 info->offset = offset;
3574 info->bytes = bytes;
3575 info->max_extent_size = 0;
3576 ret = link_free_space(ctl, info);
3577 spin_unlock(&ctl->tree_lock);
3578 if (ret)
3579 kmem_cache_free(btrfs_free_space_cachep, info);
3580 return ret;
3581 }
3582
3583 if (!map) {
3584 map = kzalloc(PAGE_SIZE, GFP_NOFS);
3585 if (!map) {
3586 kmem_cache_free(btrfs_free_space_cachep, info);
3587 return -ENOMEM;
3588 }
3589 }
3590
3591 spin_lock(&ctl->tree_lock);
3592 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3593 1, 0);
3594 if (!bitmap_info) {
3595 info->bitmap = map;
3596 map = NULL;
3597 add_new_bitmap(ctl, info, offset);
3598 bitmap_info = info;
3599 info = NULL;
3600 }
3601
3602 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3603
3604 bytes -= bytes_added;
3605 offset += bytes_added;
3606 spin_unlock(&ctl->tree_lock);
3607
3608 if (bytes)
3609 goto again;
3610
3611 if (info)
3612 kmem_cache_free(btrfs_free_space_cachep, info);
3613 if (map)
3614 kfree(map);
3615 return 0;
3616 }
3617
3618 /*
3619 * Checks to see if the given range is in the free space cache. This is really
3620 * just used to check the absence of space, so if there is free space in the
3621 * range at all we will return 1.
3622 */
3623 int test_check_exists(struct btrfs_block_group_cache *cache,
3624 u64 offset, u64 bytes)
3625 {
3626 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3627 struct btrfs_free_space *info;
3628 int ret = 0;
3629
3630 spin_lock(&ctl->tree_lock);
3631 info = tree_search_offset(ctl, offset, 0, 0);
3632 if (!info) {
3633 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3634 1, 0);
3635 if (!info)
3636 goto out;
3637 }
3638
3639 have_info:
3640 if (info->bitmap) {
3641 u64 bit_off, bit_bytes;
3642 struct rb_node *n;
3643 struct btrfs_free_space *tmp;
3644
3645 bit_off = offset;
3646 bit_bytes = ctl->unit;
3647 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
3648 if (!ret) {
3649 if (bit_off == offset) {
3650 ret = 1;
3651 goto out;
3652 } else if (bit_off > offset &&
3653 offset + bytes > bit_off) {
3654 ret = 1;
3655 goto out;
3656 }
3657 }
3658
3659 n = rb_prev(&info->offset_index);
3660 while (n) {
3661 tmp = rb_entry(n, struct btrfs_free_space,
3662 offset_index);
3663 if (tmp->offset + tmp->bytes < offset)
3664 break;
3665 if (offset + bytes < tmp->offset) {
3666 n = rb_prev(&tmp->offset_index);
3667 continue;
3668 }
3669 info = tmp;
3670 goto have_info;
3671 }
3672
3673 n = rb_next(&info->offset_index);
3674 while (n) {
3675 tmp = rb_entry(n, struct btrfs_free_space,
3676 offset_index);
3677 if (offset + bytes < tmp->offset)
3678 break;
3679 if (tmp->offset + tmp->bytes < offset) {
3680 n = rb_next(&tmp->offset_index);
3681 continue;
3682 }
3683 info = tmp;
3684 goto have_info;
3685 }
3686
3687 ret = 0;
3688 goto out;
3689 }
3690
3691 if (info->offset == offset) {
3692 ret = 1;
3693 goto out;
3694 }
3695
3696 if (offset > info->offset && offset < info->offset + info->bytes)
3697 ret = 1;
3698 out:
3699 spin_unlock(&ctl->tree_lock);
3700 return ret;
3701 }
3702 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Linux with added FPC-III support