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drm: Use srcu to protect drm_device.unplugged
[linux/fpc-iii.git] / fs / btrfs / free-space-cache.c
bloba9f22ac50d6a92095dd43d35e613091b5dc6fc87
1 /*
2 * Copyright (C) 2008 Red Hat. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/pagemap.h>
20 #include <linux/sched.h>
21 #include <linux/sched/signal.h>
22 #include <linux/slab.h>
23 #include <linux/math64.h>
24 #include <linux/ratelimit.h>
25 #include <linux/error-injection.h>
26 #include "ctree.h"
27 #include "free-space-cache.h"
28 #include "transaction.h"
29 #include "disk-io.h"
30 #include "extent_io.h"
31 #include "inode-map.h"
32 #include "volumes.h"
33
34 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
35 #define MAX_CACHE_BYTES_PER_GIG SZ_32K
36
37 struct btrfs_trim_range {
38 u64 start;
39 u64 bytes;
40 struct list_head list;
41 };
42
43 static int link_free_space(struct btrfs_free_space_ctl *ctl,
44 struct btrfs_free_space *info);
45 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
46 struct btrfs_free_space *info);
47 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
48 struct btrfs_trans_handle *trans,
49 struct btrfs_io_ctl *io_ctl,
50 struct btrfs_path *path);
51
52 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
53 struct btrfs_path *path,
54 u64 offset)
55 {
56 struct btrfs_fs_info *fs_info = root->fs_info;
57 struct btrfs_key key;
58 struct btrfs_key location;
59 struct btrfs_disk_key disk_key;
60 struct btrfs_free_space_header *header;
61 struct extent_buffer *leaf;
62 struct inode *inode = NULL;
63 int ret;
64
65 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
66 key.offset = offset;
67 key.type = 0;
68
69 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
70 if (ret < 0)
71 return ERR_PTR(ret);
72 if (ret > 0) {
73 btrfs_release_path(path);
74 return ERR_PTR(-ENOENT);
75 }
76
77 leaf = path->nodes[0];
78 header = btrfs_item_ptr(leaf, path->slots[0],
79 struct btrfs_free_space_header);
80 btrfs_free_space_key(leaf, header, &disk_key);
81 btrfs_disk_key_to_cpu(&location, &disk_key);
82 btrfs_release_path(path);
83
84 inode = btrfs_iget(fs_info->sb, &location, root, NULL);
85 if (IS_ERR(inode))
86 return inode;
87 if (is_bad_inode(inode)) {
88 iput(inode);
89 return ERR_PTR(-ENOENT);
90 }
91
92 mapping_set_gfp_mask(inode->i_mapping,
93 mapping_gfp_constraint(inode->i_mapping,
94 ~(__GFP_FS | __GFP_HIGHMEM)));
95
96 return inode;
97 }
98
99 struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
100 struct btrfs_block_group_cache
101 *block_group, struct btrfs_path *path)
102 {
103 struct inode *inode = NULL;
104 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
105
106 spin_lock(&block_group->lock);
107 if (block_group->inode)
108 inode = igrab(block_group->inode);
109 spin_unlock(&block_group->lock);
110 if (inode)
111 return inode;
112
113 inode = __lookup_free_space_inode(fs_info->tree_root, path,
114 block_group->key.objectid);
115 if (IS_ERR(inode))
116 return inode;
117
118 spin_lock(&block_group->lock);
119 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
120 btrfs_info(fs_info, "Old style space inode found, converting.");
121 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
122 BTRFS_INODE_NODATACOW;
123 block_group->disk_cache_state = BTRFS_DC_CLEAR;
124 }
125
126 if (!block_group->iref) {
127 block_group->inode = igrab(inode);
128 block_group->iref = 1;
129 }
130 spin_unlock(&block_group->lock);
131
132 return inode;
133 }
134
135 static int __create_free_space_inode(struct btrfs_root *root,
136 struct btrfs_trans_handle *trans,
137 struct btrfs_path *path,
138 u64 ino, u64 offset)
139 {
140 struct btrfs_key key;
141 struct btrfs_disk_key disk_key;
142 struct btrfs_free_space_header *header;
143 struct btrfs_inode_item *inode_item;
144 struct extent_buffer *leaf;
145 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
146 int ret;
147
148 ret = btrfs_insert_empty_inode(trans, root, path, ino);
149 if (ret)
150 return ret;
151
152 /* We inline crc's for the free disk space cache */
153 if (ino != BTRFS_FREE_INO_OBJECTID)
154 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
155
156 leaf = path->nodes[0];
157 inode_item = btrfs_item_ptr(leaf, path->slots[0],
158 struct btrfs_inode_item);
159 btrfs_item_key(leaf, &disk_key, path->slots[0]);
160 memzero_extent_buffer(leaf, (unsigned long)inode_item,
161 sizeof(*inode_item));
162 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
163 btrfs_set_inode_size(leaf, inode_item, 0);
164 btrfs_set_inode_nbytes(leaf, inode_item, 0);
165 btrfs_set_inode_uid(leaf, inode_item, 0);
166 btrfs_set_inode_gid(leaf, inode_item, 0);
167 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
168 btrfs_set_inode_flags(leaf, inode_item, flags);
169 btrfs_set_inode_nlink(leaf, inode_item, 1);
170 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
171 btrfs_set_inode_block_group(leaf, inode_item, offset);
172 btrfs_mark_buffer_dirty(leaf);
173 btrfs_release_path(path);
174
175 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
176 key.offset = offset;
177 key.type = 0;
178 ret = btrfs_insert_empty_item(trans, root, path, &key,
179 sizeof(struct btrfs_free_space_header));
180 if (ret < 0) {
181 btrfs_release_path(path);
182 return ret;
183 }
184
185 leaf = path->nodes[0];
186 header = btrfs_item_ptr(leaf, path->slots[0],
187 struct btrfs_free_space_header);
188 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
189 btrfs_set_free_space_key(leaf, header, &disk_key);
190 btrfs_mark_buffer_dirty(leaf);
191 btrfs_release_path(path);
192
193 return 0;
194 }
195
196 int create_free_space_inode(struct btrfs_fs_info *fs_info,
197 struct btrfs_trans_handle *trans,
198 struct btrfs_block_group_cache *block_group,
199 struct btrfs_path *path)
200 {
201 int ret;
202 u64 ino;
203
204 ret = btrfs_find_free_objectid(fs_info->tree_root, &ino);
205 if (ret < 0)
206 return ret;
207
208 return __create_free_space_inode(fs_info->tree_root, trans, path, ino,
209 block_group->key.objectid);
210 }
211
212 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
213 struct btrfs_block_rsv *rsv)
214 {
215 u64 needed_bytes;
216 int ret;
217
218 /* 1 for slack space, 1 for updating the inode */
219 needed_bytes = btrfs_calc_trunc_metadata_size(fs_info, 1) +
220 btrfs_calc_trans_metadata_size(fs_info, 1);
221
222 spin_lock(&rsv->lock);
223 if (rsv->reserved < needed_bytes)
224 ret = -ENOSPC;
225 else
226 ret = 0;
227 spin_unlock(&rsv->lock);
228 return ret;
229 }
230
231 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
232 struct btrfs_block_group_cache *block_group,
233 struct inode *inode)
234 {
235 struct btrfs_root *root = BTRFS_I(inode)->root;
236 int ret = 0;
237 bool locked = false;
238
239 if (block_group) {
240 struct btrfs_path *path = btrfs_alloc_path();
241
242 if (!path) {
243 ret = -ENOMEM;
244 goto fail;
245 }
246 locked = true;
247 mutex_lock(&trans->transaction->cache_write_mutex);
248 if (!list_empty(&block_group->io_list)) {
249 list_del_init(&block_group->io_list);
250
251 btrfs_wait_cache_io(trans, block_group, path);
252 btrfs_put_block_group(block_group);
253 }
254
255 /*
256 * now that we've truncated the cache away, its no longer
257 * setup or written
258 */
259 spin_lock(&block_group->lock);
260 block_group->disk_cache_state = BTRFS_DC_CLEAR;
261 spin_unlock(&block_group->lock);
262 btrfs_free_path(path);
263 }
264
265 btrfs_i_size_write(BTRFS_I(inode), 0);
266 truncate_pagecache(inode, 0);
267
268 /*
269 * We don't need an orphan item because truncating the free space cache
270 * will never be split across transactions.
271 * We don't need to check for -EAGAIN because we're a free space
272 * cache inode
273 */
274 ret = btrfs_truncate_inode_items(trans, root, inode,
275 0, BTRFS_EXTENT_DATA_KEY);
276 if (ret)
277 goto fail;
278
279 ret = btrfs_update_inode(trans, root, inode);
280
281 fail:
282 if (locked)
283 mutex_unlock(&trans->transaction->cache_write_mutex);
284 if (ret)
285 btrfs_abort_transaction(trans, ret);
286
287 return ret;
288 }
289
290 static void readahead_cache(struct inode *inode)
291 {
292 struct file_ra_state *ra;
293 unsigned long last_index;
294
295 ra = kzalloc(sizeof(*ra), GFP_NOFS);
296 if (!ra)
297 return;
298
299 file_ra_state_init(ra, inode->i_mapping);
300 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
301
302 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
303
304 kfree(ra);
305 }
306
307 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
308 int write)
309 {
310 int num_pages;
311 int check_crcs = 0;
312
313 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
314
315 if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
316 check_crcs = 1;
317
318 /* Make sure we can fit our crcs into the first page */
319 if (write && check_crcs &&
320 (num_pages * sizeof(u32)) >= PAGE_SIZE)
321 return -ENOSPC;
322
323 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
324
325 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
326 if (!io_ctl->pages)
327 return -ENOMEM;
328
329 io_ctl->num_pages = num_pages;
330 io_ctl->fs_info = btrfs_sb(inode->i_sb);
331 io_ctl->check_crcs = check_crcs;
332 io_ctl->inode = inode;
333
334 return 0;
335 }
336 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
337
338 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
339 {
340 kfree(io_ctl->pages);
341 io_ctl->pages = NULL;
342 }
343
344 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
345 {
346 if (io_ctl->cur) {
347 io_ctl->cur = NULL;
348 io_ctl->orig = NULL;
349 }
350 }
351
352 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
353 {
354 ASSERT(io_ctl->index < io_ctl->num_pages);
355 io_ctl->page = io_ctl->pages[io_ctl->index++];
356 io_ctl->cur = page_address(io_ctl->page);
357 io_ctl->orig = io_ctl->cur;
358 io_ctl->size = PAGE_SIZE;
359 if (clear)
360 clear_page(io_ctl->cur);
361 }
362
363 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
364 {
365 int i;
366
367 io_ctl_unmap_page(io_ctl);
368
369 for (i = 0; i < io_ctl->num_pages; i++) {
370 if (io_ctl->pages[i]) {
371 ClearPageChecked(io_ctl->pages[i]);
372 unlock_page(io_ctl->pages[i]);
373 put_page(io_ctl->pages[i]);
374 }
375 }
376 }
377
378 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
379 int uptodate)
380 {
381 struct page *page;
382 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
383 int i;
384
385 for (i = 0; i < io_ctl->num_pages; i++) {
386 page = find_or_create_page(inode->i_mapping, i, mask);
387 if (!page) {
388 io_ctl_drop_pages(io_ctl);
389 return -ENOMEM;
390 }
391 io_ctl->pages[i] = page;
392 if (uptodate && !PageUptodate(page)) {
393 btrfs_readpage(NULL, page);
394 lock_page(page);
395 if (!PageUptodate(page)) {
396 btrfs_err(BTRFS_I(inode)->root->fs_info,
397 "error reading free space cache");
398 io_ctl_drop_pages(io_ctl);
399 return -EIO;
400 }
401 }
402 }
403
404 for (i = 0; i < io_ctl->num_pages; i++) {
405 clear_page_dirty_for_io(io_ctl->pages[i]);
406 set_page_extent_mapped(io_ctl->pages[i]);
407 }
408
409 return 0;
410 }
411
412 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
413 {
414 __le64 *val;
415
416 io_ctl_map_page(io_ctl, 1);
417
418 /*
419 * Skip the csum areas. If we don't check crcs then we just have a
420 * 64bit chunk at the front of the first page.
421 */
422 if (io_ctl->check_crcs) {
423 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
424 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
425 } else {
426 io_ctl->cur += sizeof(u64);
427 io_ctl->size -= sizeof(u64) * 2;
428 }
429
430 val = io_ctl->cur;
431 *val = cpu_to_le64(generation);
432 io_ctl->cur += sizeof(u64);
433 }
434
435 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
436 {
437 __le64 *gen;
438
439 /*
440 * Skip the crc area. If we don't check crcs then we just have a 64bit
441 * chunk at the front of the first page.
442 */
443 if (io_ctl->check_crcs) {
444 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
445 io_ctl->size -= sizeof(u64) +
446 (sizeof(u32) * io_ctl->num_pages);
447 } else {
448 io_ctl->cur += sizeof(u64);
449 io_ctl->size -= sizeof(u64) * 2;
450 }
451
452 gen = io_ctl->cur;
453 if (le64_to_cpu(*gen) != generation) {
454 btrfs_err_rl(io_ctl->fs_info,
455 "space cache generation (%llu) does not match inode (%llu)",
456 *gen, generation);
457 io_ctl_unmap_page(io_ctl);
458 return -EIO;
459 }
460 io_ctl->cur += sizeof(u64);
461 return 0;
462 }
463
464 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
465 {
466 u32 *tmp;
467 u32 crc = ~(u32)0;
468 unsigned offset = 0;
469
470 if (!io_ctl->check_crcs) {
471 io_ctl_unmap_page(io_ctl);
472 return;
473 }
474
475 if (index == 0)
476 offset = sizeof(u32) * io_ctl->num_pages;
477
478 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
479 PAGE_SIZE - offset);
480 btrfs_csum_final(crc, (u8 *)&crc);
481 io_ctl_unmap_page(io_ctl);
482 tmp = page_address(io_ctl->pages[0]);
483 tmp += index;
484 *tmp = crc;
485 }
486
487 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
488 {
489 u32 *tmp, val;
490 u32 crc = ~(u32)0;
491 unsigned offset = 0;
492
493 if (!io_ctl->check_crcs) {
494 io_ctl_map_page(io_ctl, 0);
495 return 0;
496 }
497
498 if (index == 0)
499 offset = sizeof(u32) * io_ctl->num_pages;
500
501 tmp = page_address(io_ctl->pages[0]);
502 tmp += index;
503 val = *tmp;
504
505 io_ctl_map_page(io_ctl, 0);
506 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
507 PAGE_SIZE - offset);
508 btrfs_csum_final(crc, (u8 *)&crc);
509 if (val != crc) {
510 btrfs_err_rl(io_ctl->fs_info,
511 "csum mismatch on free space cache");
512 io_ctl_unmap_page(io_ctl);
513 return -EIO;
514 }
515
516 return 0;
517 }
518
519 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
520 void *bitmap)
521 {
522 struct btrfs_free_space_entry *entry;
523
524 if (!io_ctl->cur)
525 return -ENOSPC;
526
527 entry = io_ctl->cur;
528 entry->offset = cpu_to_le64(offset);
529 entry->bytes = cpu_to_le64(bytes);
530 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
531 BTRFS_FREE_SPACE_EXTENT;
532 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
533 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
534
535 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
536 return 0;
537
538 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
539
540 /* No more pages to map */
541 if (io_ctl->index >= io_ctl->num_pages)
542 return 0;
543
544 /* map the next page */
545 io_ctl_map_page(io_ctl, 1);
546 return 0;
547 }
548
549 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
550 {
551 if (!io_ctl->cur)
552 return -ENOSPC;
553
554 /*
555 * If we aren't at the start of the current page, unmap this one and
556 * map the next one if there is any left.
557 */
558 if (io_ctl->cur != io_ctl->orig) {
559 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
560 if (io_ctl->index >= io_ctl->num_pages)
561 return -ENOSPC;
562 io_ctl_map_page(io_ctl, 0);
563 }
564
565 memcpy(io_ctl->cur, bitmap, PAGE_SIZE);
566 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
567 if (io_ctl->index < io_ctl->num_pages)
568 io_ctl_map_page(io_ctl, 0);
569 return 0;
570 }
571
572 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
573 {
574 /*
575 * If we're not on the boundary we know we've modified the page and we
576 * need to crc the page.
577 */
578 if (io_ctl->cur != io_ctl->orig)
579 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
580 else
581 io_ctl_unmap_page(io_ctl);
582
583 while (io_ctl->index < io_ctl->num_pages) {
584 io_ctl_map_page(io_ctl, 1);
585 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
586 }
587 }
588
589 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
590 struct btrfs_free_space *entry, u8 *type)
591 {
592 struct btrfs_free_space_entry *e;
593 int ret;
594
595 if (!io_ctl->cur) {
596 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
597 if (ret)
598 return ret;
599 }
600
601 e = io_ctl->cur;
602 entry->offset = le64_to_cpu(e->offset);
603 entry->bytes = le64_to_cpu(e->bytes);
604 *type = e->type;
605 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
606 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
607
608 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
609 return 0;
610
611 io_ctl_unmap_page(io_ctl);
612
613 return 0;
614 }
615
616 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
617 struct btrfs_free_space *entry)
618 {
619 int ret;
620
621 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
622 if (ret)
623 return ret;
624
625 memcpy(entry->bitmap, io_ctl->cur, PAGE_SIZE);
626 io_ctl_unmap_page(io_ctl);
627
628 return 0;
629 }
630
631 /*
632 * Since we attach pinned extents after the fact we can have contiguous sections
633 * of free space that are split up in entries. This poses a problem with the
634 * tree logging stuff since it could have allocated across what appears to be 2
635 * entries since we would have merged the entries when adding the pinned extents
636 * back to the free space cache. So run through the space cache that we just
637 * loaded and merge contiguous entries. This will make the log replay stuff not
638 * blow up and it will make for nicer allocator behavior.
639 */
640 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
641 {
642 struct btrfs_free_space *e, *prev = NULL;
643 struct rb_node *n;
644
645 again:
646 spin_lock(&ctl->tree_lock);
647 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
648 e = rb_entry(n, struct btrfs_free_space, offset_index);
649 if (!prev)
650 goto next;
651 if (e->bitmap || prev->bitmap)
652 goto next;
653 if (prev->offset + prev->bytes == e->offset) {
654 unlink_free_space(ctl, prev);
655 unlink_free_space(ctl, e);
656 prev->bytes += e->bytes;
657 kmem_cache_free(btrfs_free_space_cachep, e);
658 link_free_space(ctl, prev);
659 prev = NULL;
660 spin_unlock(&ctl->tree_lock);
661 goto again;
662 }
663 next:
664 prev = e;
665 }
666 spin_unlock(&ctl->tree_lock);
667 }
668
669 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
670 struct btrfs_free_space_ctl *ctl,
671 struct btrfs_path *path, u64 offset)
672 {
673 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
674 struct btrfs_free_space_header *header;
675 struct extent_buffer *leaf;
676 struct btrfs_io_ctl io_ctl;
677 struct btrfs_key key;
678 struct btrfs_free_space *e, *n;
679 LIST_HEAD(bitmaps);
680 u64 num_entries;
681 u64 num_bitmaps;
682 u64 generation;
683 u8 type;
684 int ret = 0;
685
686 /* Nothing in the space cache, goodbye */
687 if (!i_size_read(inode))
688 return 0;
689
690 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
691 key.offset = offset;
692 key.type = 0;
693
694 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
695 if (ret < 0)
696 return 0;
697 else if (ret > 0) {
698 btrfs_release_path(path);
699 return 0;
700 }
701
702 ret = -1;
703
704 leaf = path->nodes[0];
705 header = btrfs_item_ptr(leaf, path->slots[0],
706 struct btrfs_free_space_header);
707 num_entries = btrfs_free_space_entries(leaf, header);
708 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
709 generation = btrfs_free_space_generation(leaf, header);
710 btrfs_release_path(path);
711
712 if (!BTRFS_I(inode)->generation) {
713 btrfs_info(fs_info,
714 "the free space cache file (%llu) is invalid, skip it",
715 offset);
716 return 0;
717 }
718
719 if (BTRFS_I(inode)->generation != generation) {
720 btrfs_err(fs_info,
721 "free space inode generation (%llu) did not match free space cache generation (%llu)",
722 BTRFS_I(inode)->generation, generation);
723 return 0;
724 }
725
726 if (!num_entries)
727 return 0;
728
729 ret = io_ctl_init(&io_ctl, inode, 0);
730 if (ret)
731 return ret;
732
733 readahead_cache(inode);
734
735 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
736 if (ret)
737 goto out;
738
739 ret = io_ctl_check_crc(&io_ctl, 0);
740 if (ret)
741 goto free_cache;
742
743 ret = io_ctl_check_generation(&io_ctl, generation);
744 if (ret)
745 goto free_cache;
746
747 while (num_entries) {
748 e = kmem_cache_zalloc(btrfs_free_space_cachep,
749 GFP_NOFS);
750 if (!e)
751 goto free_cache;
752
753 ret = io_ctl_read_entry(&io_ctl, e, &type);
754 if (ret) {
755 kmem_cache_free(btrfs_free_space_cachep, e);
756 goto free_cache;
757 }
758
759 if (!e->bytes) {
760 kmem_cache_free(btrfs_free_space_cachep, e);
761 goto free_cache;
762 }
763
764 if (type == BTRFS_FREE_SPACE_EXTENT) {
765 spin_lock(&ctl->tree_lock);
766 ret = link_free_space(ctl, e);
767 spin_unlock(&ctl->tree_lock);
768 if (ret) {
769 btrfs_err(fs_info,
770 "Duplicate entries in free space cache, dumping");
771 kmem_cache_free(btrfs_free_space_cachep, e);
772 goto free_cache;
773 }
774 } else {
775 ASSERT(num_bitmaps);
776 num_bitmaps--;
777 e->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
778 if (!e->bitmap) {
779 kmem_cache_free(
780 btrfs_free_space_cachep, e);
781 goto free_cache;
782 }
783 spin_lock(&ctl->tree_lock);
784 ret = link_free_space(ctl, e);
785 ctl->total_bitmaps++;
786 ctl->op->recalc_thresholds(ctl);
787 spin_unlock(&ctl->tree_lock);
788 if (ret) {
789 btrfs_err(fs_info,
790 "Duplicate entries in free space cache, dumping");
791 kmem_cache_free(btrfs_free_space_cachep, e);
792 goto free_cache;
793 }
794 list_add_tail(&e->list, &bitmaps);
795 }
796
797 num_entries--;
798 }
799
800 io_ctl_unmap_page(&io_ctl);
801
802 /*
803 * We add the bitmaps at the end of the entries in order that
804 * the bitmap entries are added to the cache.
805 */
806 list_for_each_entry_safe(e, n, &bitmaps, list) {
807 list_del_init(&e->list);
808 ret = io_ctl_read_bitmap(&io_ctl, e);
809 if (ret)
810 goto free_cache;
811 }
812
813 io_ctl_drop_pages(&io_ctl);
814 merge_space_tree(ctl);
815 ret = 1;
816 out:
817 io_ctl_free(&io_ctl);
818 return ret;
819 free_cache:
820 io_ctl_drop_pages(&io_ctl);
821 __btrfs_remove_free_space_cache(ctl);
822 goto out;
823 }
824
825 int load_free_space_cache(struct btrfs_fs_info *fs_info,
826 struct btrfs_block_group_cache *block_group)
827 {
828 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
829 struct inode *inode;
830 struct btrfs_path *path;
831 int ret = 0;
832 bool matched;
833 u64 used = btrfs_block_group_used(&block_group->item);
834
835 /*
836 * If this block group has been marked to be cleared for one reason or
837 * another then we can't trust the on disk cache, so just return.
838 */
839 spin_lock(&block_group->lock);
840 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
841 spin_unlock(&block_group->lock);
842 return 0;
843 }
844 spin_unlock(&block_group->lock);
845
846 path = btrfs_alloc_path();
847 if (!path)
848 return 0;
849 path->search_commit_root = 1;
850 path->skip_locking = 1;
851
852 inode = lookup_free_space_inode(fs_info, block_group, path);
853 if (IS_ERR(inode)) {
854 btrfs_free_path(path);
855 return 0;
856 }
857
858 /* We may have converted the inode and made the cache invalid. */
859 spin_lock(&block_group->lock);
860 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
861 spin_unlock(&block_group->lock);
862 btrfs_free_path(path);
863 goto out;
864 }
865 spin_unlock(&block_group->lock);
866
867 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
868 path, block_group->key.objectid);
869 btrfs_free_path(path);
870 if (ret <= 0)
871 goto out;
872
873 spin_lock(&ctl->tree_lock);
874 matched = (ctl->free_space == (block_group->key.offset - used -
875 block_group->bytes_super));
876 spin_unlock(&ctl->tree_lock);
877
878 if (!matched) {
879 __btrfs_remove_free_space_cache(ctl);
880 btrfs_warn(fs_info,
881 "block group %llu has wrong amount of free space",
882 block_group->key.objectid);
883 ret = -1;
884 }
885 out:
886 if (ret < 0) {
887 /* This cache is bogus, make sure it gets cleared */
888 spin_lock(&block_group->lock);
889 block_group->disk_cache_state = BTRFS_DC_CLEAR;
890 spin_unlock(&block_group->lock);
891 ret = 0;
892
893 btrfs_warn(fs_info,
894 "failed to load free space cache for block group %llu, rebuilding it now",
895 block_group->key.objectid);
896 }
897
898 iput(inode);
899 return ret;
900 }
901
902 static noinline_for_stack
903 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
904 struct btrfs_free_space_ctl *ctl,
905 struct btrfs_block_group_cache *block_group,
906 int *entries, int *bitmaps,
907 struct list_head *bitmap_list)
908 {
909 int ret;
910 struct btrfs_free_cluster *cluster = NULL;
911 struct btrfs_free_cluster *cluster_locked = NULL;
912 struct rb_node *node = rb_first(&ctl->free_space_offset);
913 struct btrfs_trim_range *trim_entry;
914
915 /* Get the cluster for this block_group if it exists */
916 if (block_group && !list_empty(&block_group->cluster_list)) {
917 cluster = list_entry(block_group->cluster_list.next,
918 struct btrfs_free_cluster,
919 block_group_list);
920 }
921
922 if (!node && cluster) {
923 cluster_locked = cluster;
924 spin_lock(&cluster_locked->lock);
925 node = rb_first(&cluster->root);
926 cluster = NULL;
927 }
928
929 /* Write out the extent entries */
930 while (node) {
931 struct btrfs_free_space *e;
932
933 e = rb_entry(node, struct btrfs_free_space, offset_index);
934 *entries += 1;
935
936 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
937 e->bitmap);
938 if (ret)
939 goto fail;
940
941 if (e->bitmap) {
942 list_add_tail(&e->list, bitmap_list);
943 *bitmaps += 1;
944 }
945 node = rb_next(node);
946 if (!node && cluster) {
947 node = rb_first(&cluster->root);
948 cluster_locked = cluster;
949 spin_lock(&cluster_locked->lock);
950 cluster = NULL;
951 }
952 }
953 if (cluster_locked) {
954 spin_unlock(&cluster_locked->lock);
955 cluster_locked = NULL;
956 }
957
958 /*
959 * Make sure we don't miss any range that was removed from our rbtree
960 * because trimming is running. Otherwise after a umount+mount (or crash
961 * after committing the transaction) we would leak free space and get
962 * an inconsistent free space cache report from fsck.
963 */
964 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
965 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
966 trim_entry->bytes, NULL);
967 if (ret)
968 goto fail;
969 *entries += 1;
970 }
971
972 return 0;
973 fail:
974 if (cluster_locked)
975 spin_unlock(&cluster_locked->lock);
976 return -ENOSPC;
977 }
978
979 static noinline_for_stack int
980 update_cache_item(struct btrfs_trans_handle *trans,
981 struct btrfs_root *root,
982 struct inode *inode,
983 struct btrfs_path *path, u64 offset,
984 int entries, int bitmaps)
985 {
986 struct btrfs_key key;
987 struct btrfs_free_space_header *header;
988 struct extent_buffer *leaf;
989 int ret;
990
991 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
992 key.offset = offset;
993 key.type = 0;
994
995 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
996 if (ret < 0) {
997 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
998 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
999 goto fail;
1000 }
1001 leaf = path->nodes[0];
1002 if (ret > 0) {
1003 struct btrfs_key found_key;
1004 ASSERT(path->slots[0]);
1005 path->slots[0]--;
1006 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1007 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1008 found_key.offset != offset) {
1009 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1010 inode->i_size - 1,
1011 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
1012 NULL);
1013 btrfs_release_path(path);
1014 goto fail;
1015 }
1016 }
1017
1018 BTRFS_I(inode)->generation = trans->transid;
1019 header = btrfs_item_ptr(leaf, path->slots[0],
1020 struct btrfs_free_space_header);
1021 btrfs_set_free_space_entries(leaf, header, entries);
1022 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1023 btrfs_set_free_space_generation(leaf, header, trans->transid);
1024 btrfs_mark_buffer_dirty(leaf);
1025 btrfs_release_path(path);
1026
1027 return 0;
1028
1029 fail:
1030 return -1;
1031 }
1032
1033 static noinline_for_stack int
1034 write_pinned_extent_entries(struct btrfs_fs_info *fs_info,
1035 struct btrfs_block_group_cache *block_group,
1036 struct btrfs_io_ctl *io_ctl,
1037 int *entries)
1038 {
1039 u64 start, extent_start, extent_end, len;
1040 struct extent_io_tree *unpin = NULL;
1041 int ret;
1042
1043 if (!block_group)
1044 return 0;
1045
1046 /*
1047 * We want to add any pinned extents to our free space cache
1048 * so we don't leak the space
1049 *
1050 * We shouldn't have switched the pinned extents yet so this is the
1051 * right one
1052 */
1053 unpin = fs_info->pinned_extents;
1054
1055 start = block_group->key.objectid;
1056
1057 while (start < block_group->key.objectid + block_group->key.offset) {
1058 ret = find_first_extent_bit(unpin, start,
1059 &extent_start, &extent_end,
1060 EXTENT_DIRTY, NULL);
1061 if (ret)
1062 return 0;
1063
1064 /* This pinned extent is out of our range */
1065 if (extent_start >= block_group->key.objectid +
1066 block_group->key.offset)
1067 return 0;
1068
1069 extent_start = max(extent_start, start);
1070 extent_end = min(block_group->key.objectid +
1071 block_group->key.offset, extent_end + 1);
1072 len = extent_end - extent_start;
1073
1074 *entries += 1;
1075 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1076 if (ret)
1077 return -ENOSPC;
1078
1079 start = extent_end;
1080 }
1081
1082 return 0;
1083 }
1084
1085 static noinline_for_stack int
1086 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1087 {
1088 struct btrfs_free_space *entry, *next;
1089 int ret;
1090
1091 /* Write out the bitmaps */
1092 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1093 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1094 if (ret)
1095 return -ENOSPC;
1096 list_del_init(&entry->list);
1097 }
1098
1099 return 0;
1100 }
1101
1102 static int flush_dirty_cache(struct inode *inode)
1103 {
1104 int ret;
1105
1106 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1107 if (ret)
1108 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1109 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
1110
1111 return ret;
1112 }
1113
1114 static void noinline_for_stack
1115 cleanup_bitmap_list(struct list_head *bitmap_list)
1116 {
1117 struct btrfs_free_space *entry, *next;
1118
1119 list_for_each_entry_safe(entry, next, bitmap_list, list)
1120 list_del_init(&entry->list);
1121 }
1122
1123 static void noinline_for_stack
1124 cleanup_write_cache_enospc(struct inode *inode,
1125 struct btrfs_io_ctl *io_ctl,
1126 struct extent_state **cached_state)
1127 {
1128 io_ctl_drop_pages(io_ctl);
1129 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1130 i_size_read(inode) - 1, cached_state);
1131 }
1132
1133 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1134 struct btrfs_trans_handle *trans,
1135 struct btrfs_block_group_cache *block_group,
1136 struct btrfs_io_ctl *io_ctl,
1137 struct btrfs_path *path, u64 offset)
1138 {
1139 int ret;
1140 struct inode *inode = io_ctl->inode;
1141 struct btrfs_fs_info *fs_info;
1142
1143 if (!inode)
1144 return 0;
1145
1146 fs_info = btrfs_sb(inode->i_sb);
1147
1148 /* Flush the dirty pages in the cache file. */
1149 ret = flush_dirty_cache(inode);
1150 if (ret)
1151 goto out;
1152
1153 /* Update the cache item to tell everyone this cache file is valid. */
1154 ret = update_cache_item(trans, root, inode, path, offset,
1155 io_ctl->entries, io_ctl->bitmaps);
1156 out:
1157 io_ctl_free(io_ctl);
1158 if (ret) {
1159 invalidate_inode_pages2(inode->i_mapping);
1160 BTRFS_I(inode)->generation = 0;
1161 if (block_group) {
1162 #ifdef DEBUG
1163 btrfs_err(fs_info,
1164 "failed to write free space cache for block group %llu",
1165 block_group->key.objectid);
1166 #endif
1167 }
1168 }
1169 btrfs_update_inode(trans, root, inode);
1170
1171 if (block_group) {
1172 /* the dirty list is protected by the dirty_bgs_lock */
1173 spin_lock(&trans->transaction->dirty_bgs_lock);
1174
1175 /* the disk_cache_state is protected by the block group lock */
1176 spin_lock(&block_group->lock);
1177
1178 /*
1179 * only mark this as written if we didn't get put back on
1180 * the dirty list while waiting for IO. Otherwise our
1181 * cache state won't be right, and we won't get written again
1182 */
1183 if (!ret && list_empty(&block_group->dirty_list))
1184 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1185 else if (ret)
1186 block_group->disk_cache_state = BTRFS_DC_ERROR;
1187
1188 spin_unlock(&block_group->lock);
1189 spin_unlock(&trans->transaction->dirty_bgs_lock);
1190 io_ctl->inode = NULL;
1191 iput(inode);
1192 }
1193
1194 return ret;
1195
1196 }
1197
1198 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
1199 struct btrfs_trans_handle *trans,
1200 struct btrfs_io_ctl *io_ctl,
1201 struct btrfs_path *path)
1202 {
1203 return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
1204 }
1205
1206 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1207 struct btrfs_block_group_cache *block_group,
1208 struct btrfs_path *path)
1209 {
1210 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1211 block_group, &block_group->io_ctl,
1212 path, block_group->key.objectid);
1213 }
1214
1215 /**
1216 * __btrfs_write_out_cache - write out cached info to an inode
1217 * @root - the root the inode belongs to
1218 * @ctl - the free space cache we are going to write out
1219 * @block_group - the block_group for this cache if it belongs to a block_group
1220 * @trans - the trans handle
1221 *
1222 * This function writes out a free space cache struct to disk for quick recovery
1223 * on mount. This will return 0 if it was successful in writing the cache out,
1224 * or an errno if it was not.
1225 */
1226 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1227 struct btrfs_free_space_ctl *ctl,
1228 struct btrfs_block_group_cache *block_group,
1229 struct btrfs_io_ctl *io_ctl,
1230 struct btrfs_trans_handle *trans)
1231 {
1232 struct btrfs_fs_info *fs_info = root->fs_info;
1233 struct extent_state *cached_state = NULL;
1234 LIST_HEAD(bitmap_list);
1235 int entries = 0;
1236 int bitmaps = 0;
1237 int ret;
1238 int must_iput = 0;
1239
1240 if (!i_size_read(inode))
1241 return -EIO;
1242
1243 WARN_ON(io_ctl->pages);
1244 ret = io_ctl_init(io_ctl, inode, 1);
1245 if (ret)
1246 return ret;
1247
1248 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1249 down_write(&block_group->data_rwsem);
1250 spin_lock(&block_group->lock);
1251 if (block_group->delalloc_bytes) {
1252 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1253 spin_unlock(&block_group->lock);
1254 up_write(&block_group->data_rwsem);
1255 BTRFS_I(inode)->generation = 0;
1256 ret = 0;
1257 must_iput = 1;
1258 goto out;
1259 }
1260 spin_unlock(&block_group->lock);
1261 }
1262
1263 /* Lock all pages first so we can lock the extent safely. */
1264 ret = io_ctl_prepare_pages(io_ctl, inode, 0);
1265 if (ret)
1266 goto out_unlock;
1267
1268 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1269 &cached_state);
1270
1271 io_ctl_set_generation(io_ctl, trans->transid);
1272
1273 mutex_lock(&ctl->cache_writeout_mutex);
1274 /* Write out the extent entries in the free space cache */
1275 spin_lock(&ctl->tree_lock);
1276 ret = write_cache_extent_entries(io_ctl, ctl,
1277 block_group, &entries, &bitmaps,
1278 &bitmap_list);
1279 if (ret)
1280 goto out_nospc_locked;
1281
1282 /*
1283 * Some spaces that are freed in the current transaction are pinned,
1284 * they will be added into free space cache after the transaction is
1285 * committed, we shouldn't lose them.
1286 *
1287 * If this changes while we are working we'll get added back to
1288 * the dirty list and redo it. No locking needed
1289 */
1290 ret = write_pinned_extent_entries(fs_info, block_group,
1291 io_ctl, &entries);
1292 if (ret)
1293 goto out_nospc_locked;
1294
1295 /*
1296 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1297 * locked while doing it because a concurrent trim can be manipulating
1298 * or freeing the bitmap.
1299 */
1300 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1301 spin_unlock(&ctl->tree_lock);
1302 mutex_unlock(&ctl->cache_writeout_mutex);
1303 if (ret)
1304 goto out_nospc;
1305
1306 /* Zero out the rest of the pages just to make sure */
1307 io_ctl_zero_remaining_pages(io_ctl);
1308
1309 /* Everything is written out, now we dirty the pages in the file. */
1310 ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
1311 i_size_read(inode), &cached_state);
1312 if (ret)
1313 goto out_nospc;
1314
1315 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1316 up_write(&block_group->data_rwsem);
1317 /*
1318 * Release the pages and unlock the extent, we will flush
1319 * them out later
1320 */
1321 io_ctl_drop_pages(io_ctl);
1322
1323 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1324 i_size_read(inode) - 1, &cached_state);
1325
1326 /*
1327 * at this point the pages are under IO and we're happy,
1328 * The caller is responsible for waiting on them and updating the
1329 * the cache and the inode
1330 */
1331 io_ctl->entries = entries;
1332 io_ctl->bitmaps = bitmaps;
1333
1334 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1335 if (ret)
1336 goto out;
1337
1338 return 0;
1339
1340 out:
1341 io_ctl->inode = NULL;
1342 io_ctl_free(io_ctl);
1343 if (ret) {
1344 invalidate_inode_pages2(inode->i_mapping);
1345 BTRFS_I(inode)->generation = 0;
1346 }
1347 btrfs_update_inode(trans, root, inode);
1348 if (must_iput)
1349 iput(inode);
1350 return ret;
1351
1352 out_nospc_locked:
1353 cleanup_bitmap_list(&bitmap_list);
1354 spin_unlock(&ctl->tree_lock);
1355 mutex_unlock(&ctl->cache_writeout_mutex);
1356
1357 out_nospc:
1358 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1359
1360 out_unlock:
1361 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1362 up_write(&block_group->data_rwsem);
1363
1364 goto out;
1365 }
1366
1367 int btrfs_write_out_cache(struct btrfs_fs_info *fs_info,
1368 struct btrfs_trans_handle *trans,
1369 struct btrfs_block_group_cache *block_group,
1370 struct btrfs_path *path)
1371 {
1372 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1373 struct inode *inode;
1374 int ret = 0;
1375
1376 spin_lock(&block_group->lock);
1377 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1378 spin_unlock(&block_group->lock);
1379 return 0;
1380 }
1381 spin_unlock(&block_group->lock);
1382
1383 inode = lookup_free_space_inode(fs_info, block_group, path);
1384 if (IS_ERR(inode))
1385 return 0;
1386
1387 ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
1388 block_group, &block_group->io_ctl, trans);
1389 if (ret) {
1390 #ifdef DEBUG
1391 btrfs_err(fs_info,
1392 "failed to write free space cache for block group %llu",
1393 block_group->key.objectid);
1394 #endif
1395 spin_lock(&block_group->lock);
1396 block_group->disk_cache_state = BTRFS_DC_ERROR;
1397 spin_unlock(&block_group->lock);
1398
1399 block_group->io_ctl.inode = NULL;
1400 iput(inode);
1401 }
1402
1403 /*
1404 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1405 * to wait for IO and put the inode
1406 */
1407
1408 return ret;
1409 }
1410
1411 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1412 u64 offset)
1413 {
1414 ASSERT(offset >= bitmap_start);
1415 offset -= bitmap_start;
1416 return (unsigned long)(div_u64(offset, unit));
1417 }
1418
1419 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1420 {
1421 return (unsigned long)(div_u64(bytes, unit));
1422 }
1423
1424 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1425 u64 offset)
1426 {
1427 u64 bitmap_start;
1428 u64 bytes_per_bitmap;
1429
1430 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1431 bitmap_start = offset - ctl->start;
1432 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1433 bitmap_start *= bytes_per_bitmap;
1434 bitmap_start += ctl->start;
1435
1436 return bitmap_start;
1437 }
1438
1439 static int tree_insert_offset(struct rb_root *root, u64 offset,
1440 struct rb_node *node, int bitmap)
1441 {
1442 struct rb_node **p = &root->rb_node;
1443 struct rb_node *parent = NULL;
1444 struct btrfs_free_space *info;
1445
1446 while (*p) {
1447 parent = *p;
1448 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1449
1450 if (offset < info->offset) {
1451 p = &(*p)->rb_left;
1452 } else if (offset > info->offset) {
1453 p = &(*p)->rb_right;
1454 } else {
1455 /*
1456 * we could have a bitmap entry and an extent entry
1457 * share the same offset. If this is the case, we want
1458 * the extent entry to always be found first if we do a
1459 * linear search through the tree, since we want to have
1460 * the quickest allocation time, and allocating from an
1461 * extent is faster than allocating from a bitmap. So
1462 * if we're inserting a bitmap and we find an entry at
1463 * this offset, we want to go right, or after this entry
1464 * logically. If we are inserting an extent and we've
1465 * found a bitmap, we want to go left, or before
1466 * logically.
1467 */
1468 if (bitmap) {
1469 if (info->bitmap) {
1470 WARN_ON_ONCE(1);
1471 return -EEXIST;
1472 }
1473 p = &(*p)->rb_right;
1474 } else {
1475 if (!info->bitmap) {
1476 WARN_ON_ONCE(1);
1477 return -EEXIST;
1478 }
1479 p = &(*p)->rb_left;
1480 }
1481 }
1482 }
1483
1484 rb_link_node(node, parent, p);
1485 rb_insert_color(node, root);
1486
1487 return 0;
1488 }
1489
1490 /*
1491 * searches the tree for the given offset.
1492 *
1493 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1494 * want a section that has at least bytes size and comes at or after the given
1495 * offset.
1496 */
1497 static struct btrfs_free_space *
1498 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1499 u64 offset, int bitmap_only, int fuzzy)
1500 {
1501 struct rb_node *n = ctl->free_space_offset.rb_node;
1502 struct btrfs_free_space *entry, *prev = NULL;
1503
1504 /* find entry that is closest to the 'offset' */
1505 while (1) {
1506 if (!n) {
1507 entry = NULL;
1508 break;
1509 }
1510
1511 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1512 prev = entry;
1513
1514 if (offset < entry->offset)
1515 n = n->rb_left;
1516 else if (offset > entry->offset)
1517 n = n->rb_right;
1518 else
1519 break;
1520 }
1521
1522 if (bitmap_only) {
1523 if (!entry)
1524 return NULL;
1525 if (entry->bitmap)
1526 return entry;
1527
1528 /*
1529 * bitmap entry and extent entry may share same offset,
1530 * in that case, bitmap entry comes after extent entry.
1531 */
1532 n = rb_next(n);
1533 if (!n)
1534 return NULL;
1535 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1536 if (entry->offset != offset)
1537 return NULL;
1538
1539 WARN_ON(!entry->bitmap);
1540 return entry;
1541 } else if (entry) {
1542 if (entry->bitmap) {
1543 /*
1544 * if previous extent entry covers the offset,
1545 * we should return it instead of the bitmap entry
1546 */
1547 n = rb_prev(&entry->offset_index);
1548 if (n) {
1549 prev = rb_entry(n, struct btrfs_free_space,
1550 offset_index);
1551 if (!prev->bitmap &&
1552 prev->offset + prev->bytes > offset)
1553 entry = prev;
1554 }
1555 }
1556 return entry;
1557 }
1558
1559 if (!prev)
1560 return NULL;
1561
1562 /* find last entry before the 'offset' */
1563 entry = prev;
1564 if (entry->offset > offset) {
1565 n = rb_prev(&entry->offset_index);
1566 if (n) {
1567 entry = rb_entry(n, struct btrfs_free_space,
1568 offset_index);
1569 ASSERT(entry->offset <= offset);
1570 } else {
1571 if (fuzzy)
1572 return entry;
1573 else
1574 return NULL;
1575 }
1576 }
1577
1578 if (entry->bitmap) {
1579 n = rb_prev(&entry->offset_index);
1580 if (n) {
1581 prev = rb_entry(n, struct btrfs_free_space,
1582 offset_index);
1583 if (!prev->bitmap &&
1584 prev->offset + prev->bytes > offset)
1585 return prev;
1586 }
1587 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1588 return entry;
1589 } else if (entry->offset + entry->bytes > offset)
1590 return entry;
1591
1592 if (!fuzzy)
1593 return NULL;
1594
1595 while (1) {
1596 if (entry->bitmap) {
1597 if (entry->offset + BITS_PER_BITMAP *
1598 ctl->unit > offset)
1599 break;
1600 } else {
1601 if (entry->offset + entry->bytes > offset)
1602 break;
1603 }
1604
1605 n = rb_next(&entry->offset_index);
1606 if (!n)
1607 return NULL;
1608 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1609 }
1610 return entry;
1611 }
1612
1613 static inline void
1614 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1615 struct btrfs_free_space *info)
1616 {
1617 rb_erase(&info->offset_index, &ctl->free_space_offset);
1618 ctl->free_extents--;
1619 }
1620
1621 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1622 struct btrfs_free_space *info)
1623 {
1624 __unlink_free_space(ctl, info);
1625 ctl->free_space -= info->bytes;
1626 }
1627
1628 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1629 struct btrfs_free_space *info)
1630 {
1631 int ret = 0;
1632
1633 ASSERT(info->bytes || info->bitmap);
1634 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1635 &info->offset_index, (info->bitmap != NULL));
1636 if (ret)
1637 return ret;
1638
1639 ctl->free_space += info->bytes;
1640 ctl->free_extents++;
1641 return ret;
1642 }
1643
1644 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1645 {
1646 struct btrfs_block_group_cache *block_group = ctl->private;
1647 u64 max_bytes;
1648 u64 bitmap_bytes;
1649 u64 extent_bytes;
1650 u64 size = block_group->key.offset;
1651 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1652 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1653
1654 max_bitmaps = max_t(u64, max_bitmaps, 1);
1655
1656 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1657
1658 /*
1659 * The goal is to keep the total amount of memory used per 1gb of space
1660 * at or below 32k, so we need to adjust how much memory we allow to be
1661 * used by extent based free space tracking
1662 */
1663 if (size < SZ_1G)
1664 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1665 else
1666 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1667
1668 /*
1669 * we want to account for 1 more bitmap than what we have so we can make
1670 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1671 * we add more bitmaps.
1672 */
1673 bitmap_bytes = (ctl->total_bitmaps + 1) * ctl->unit;
1674
1675 if (bitmap_bytes >= max_bytes) {
1676 ctl->extents_thresh = 0;
1677 return;
1678 }
1679
1680 /*
1681 * we want the extent entry threshold to always be at most 1/2 the max
1682 * bytes we can have, or whatever is less than that.
1683 */
1684 extent_bytes = max_bytes - bitmap_bytes;
1685 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1686
1687 ctl->extents_thresh =
1688 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1689 }
1690
1691 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1692 struct btrfs_free_space *info,
1693 u64 offset, u64 bytes)
1694 {
1695 unsigned long start, count;
1696
1697 start = offset_to_bit(info->offset, ctl->unit, offset);
1698 count = bytes_to_bits(bytes, ctl->unit);
1699 ASSERT(start + count <= BITS_PER_BITMAP);
1700
1701 bitmap_clear(info->bitmap, start, count);
1702
1703 info->bytes -= bytes;
1704 }
1705
1706 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1707 struct btrfs_free_space *info, u64 offset,
1708 u64 bytes)
1709 {
1710 __bitmap_clear_bits(ctl, info, offset, bytes);
1711 ctl->free_space -= bytes;
1712 }
1713
1714 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1715 struct btrfs_free_space *info, u64 offset,
1716 u64 bytes)
1717 {
1718 unsigned long start, count;
1719
1720 start = offset_to_bit(info->offset, ctl->unit, offset);
1721 count = bytes_to_bits(bytes, ctl->unit);
1722 ASSERT(start + count <= BITS_PER_BITMAP);
1723
1724 bitmap_set(info->bitmap, start, count);
1725
1726 info->bytes += bytes;
1727 ctl->free_space += bytes;
1728 }
1729
1730 /*
1731 * If we can not find suitable extent, we will use bytes to record
1732 * the size of the max extent.
1733 */
1734 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1735 struct btrfs_free_space *bitmap_info, u64 *offset,
1736 u64 *bytes, bool for_alloc)
1737 {
1738 unsigned long found_bits = 0;
1739 unsigned long max_bits = 0;
1740 unsigned long bits, i;
1741 unsigned long next_zero;
1742 unsigned long extent_bits;
1743
1744 /*
1745 * Skip searching the bitmap if we don't have a contiguous section that
1746 * is large enough for this allocation.
1747 */
1748 if (for_alloc &&
1749 bitmap_info->max_extent_size &&
1750 bitmap_info->max_extent_size < *bytes) {
1751 *bytes = bitmap_info->max_extent_size;
1752 return -1;
1753 }
1754
1755 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1756 max_t(u64, *offset, bitmap_info->offset));
1757 bits = bytes_to_bits(*bytes, ctl->unit);
1758
1759 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1760 if (for_alloc && bits == 1) {
1761 found_bits = 1;
1762 break;
1763 }
1764 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1765 BITS_PER_BITMAP, i);
1766 extent_bits = next_zero - i;
1767 if (extent_bits >= bits) {
1768 found_bits = extent_bits;
1769 break;
1770 } else if (extent_bits > max_bits) {
1771 max_bits = extent_bits;
1772 }
1773 i = next_zero;
1774 }
1775
1776 if (found_bits) {
1777 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1778 *bytes = (u64)(found_bits) * ctl->unit;
1779 return 0;
1780 }
1781
1782 *bytes = (u64)(max_bits) * ctl->unit;
1783 bitmap_info->max_extent_size = *bytes;
1784 return -1;
1785 }
1786
1787 /* Cache the size of the max extent in bytes */
1788 static struct btrfs_free_space *
1789 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1790 unsigned long align, u64 *max_extent_size)
1791 {
1792 struct btrfs_free_space *entry;
1793 struct rb_node *node;
1794 u64 tmp;
1795 u64 align_off;
1796 int ret;
1797
1798 if (!ctl->free_space_offset.rb_node)
1799 goto out;
1800
1801 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1802 if (!entry)
1803 goto out;
1804
1805 for (node = &entry->offset_index; node; node = rb_next(node)) {
1806 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1807 if (entry->bytes < *bytes) {
1808 if (entry->bytes > *max_extent_size)
1809 *max_extent_size = entry->bytes;
1810 continue;
1811 }
1812
1813 /* make sure the space returned is big enough
1814 * to match our requested alignment
1815 */
1816 if (*bytes >= align) {
1817 tmp = entry->offset - ctl->start + align - 1;
1818 tmp = div64_u64(tmp, align);
1819 tmp = tmp * align + ctl->start;
1820 align_off = tmp - entry->offset;
1821 } else {
1822 align_off = 0;
1823 tmp = entry->offset;
1824 }
1825
1826 if (entry->bytes < *bytes + align_off) {
1827 if (entry->bytes > *max_extent_size)
1828 *max_extent_size = entry->bytes;
1829 continue;
1830 }
1831
1832 if (entry->bitmap) {
1833 u64 size = *bytes;
1834
1835 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1836 if (!ret) {
1837 *offset = tmp;
1838 *bytes = size;
1839 return entry;
1840 } else if (size > *max_extent_size) {
1841 *max_extent_size = size;
1842 }
1843 continue;
1844 }
1845
1846 *offset = tmp;
1847 *bytes = entry->bytes - align_off;
1848 return entry;
1849 }
1850 out:
1851 return NULL;
1852 }
1853
1854 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1855 struct btrfs_free_space *info, u64 offset)
1856 {
1857 info->offset = offset_to_bitmap(ctl, offset);
1858 info->bytes = 0;
1859 INIT_LIST_HEAD(&info->list);
1860 link_free_space(ctl, info);
1861 ctl->total_bitmaps++;
1862
1863 ctl->op->recalc_thresholds(ctl);
1864 }
1865
1866 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1867 struct btrfs_free_space *bitmap_info)
1868 {
1869 unlink_free_space(ctl, bitmap_info);
1870 kfree(bitmap_info->bitmap);
1871 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1872 ctl->total_bitmaps--;
1873 ctl->op->recalc_thresholds(ctl);
1874 }
1875
1876 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1877 struct btrfs_free_space *bitmap_info,
1878 u64 *offset, u64 *bytes)
1879 {
1880 u64 end;
1881 u64 search_start, search_bytes;
1882 int ret;
1883
1884 again:
1885 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1886
1887 /*
1888 * We need to search for bits in this bitmap. We could only cover some
1889 * of the extent in this bitmap thanks to how we add space, so we need
1890 * to search for as much as it as we can and clear that amount, and then
1891 * go searching for the next bit.
1892 */
1893 search_start = *offset;
1894 search_bytes = ctl->unit;
1895 search_bytes = min(search_bytes, end - search_start + 1);
1896 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1897 false);
1898 if (ret < 0 || search_start != *offset)
1899 return -EINVAL;
1900
1901 /* We may have found more bits than what we need */
1902 search_bytes = min(search_bytes, *bytes);
1903
1904 /* Cannot clear past the end of the bitmap */
1905 search_bytes = min(search_bytes, end - search_start + 1);
1906
1907 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1908 *offset += search_bytes;
1909 *bytes -= search_bytes;
1910
1911 if (*bytes) {
1912 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1913 if (!bitmap_info->bytes)
1914 free_bitmap(ctl, bitmap_info);
1915
1916 /*
1917 * no entry after this bitmap, but we still have bytes to
1918 * remove, so something has gone wrong.
1919 */
1920 if (!next)
1921 return -EINVAL;
1922
1923 bitmap_info = rb_entry(next, struct btrfs_free_space,
1924 offset_index);
1925
1926 /*
1927 * if the next entry isn't a bitmap we need to return to let the
1928 * extent stuff do its work.
1929 */
1930 if (!bitmap_info->bitmap)
1931 return -EAGAIN;
1932
1933 /*
1934 * Ok the next item is a bitmap, but it may not actually hold
1935 * the information for the rest of this free space stuff, so
1936 * look for it, and if we don't find it return so we can try
1937 * everything over again.
1938 */
1939 search_start = *offset;
1940 search_bytes = ctl->unit;
1941 ret = search_bitmap(ctl, bitmap_info, &search_start,
1942 &search_bytes, false);
1943 if (ret < 0 || search_start != *offset)
1944 return -EAGAIN;
1945
1946 goto again;
1947 } else if (!bitmap_info->bytes)
1948 free_bitmap(ctl, bitmap_info);
1949
1950 return 0;
1951 }
1952
1953 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1954 struct btrfs_free_space *info, u64 offset,
1955 u64 bytes)
1956 {
1957 u64 bytes_to_set = 0;
1958 u64 end;
1959
1960 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1961
1962 bytes_to_set = min(end - offset, bytes);
1963
1964 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1965
1966 /*
1967 * We set some bytes, we have no idea what the max extent size is
1968 * anymore.
1969 */
1970 info->max_extent_size = 0;
1971
1972 return bytes_to_set;
1973
1974 }
1975
1976 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1977 struct btrfs_free_space *info)
1978 {
1979 struct btrfs_block_group_cache *block_group = ctl->private;
1980 struct btrfs_fs_info *fs_info = block_group->fs_info;
1981 bool forced = false;
1982
1983 #ifdef CONFIG_BTRFS_DEBUG
1984 if (btrfs_should_fragment_free_space(block_group))
1985 forced = true;
1986 #endif
1987
1988 /*
1989 * If we are below the extents threshold then we can add this as an
1990 * extent, and don't have to deal with the bitmap
1991 */
1992 if (!forced && ctl->free_extents < ctl->extents_thresh) {
1993 /*
1994 * If this block group has some small extents we don't want to
1995 * use up all of our free slots in the cache with them, we want
1996 * to reserve them to larger extents, however if we have plenty
1997 * of cache left then go ahead an dadd them, no sense in adding
1998 * the overhead of a bitmap if we don't have to.
1999 */
2000 if (info->bytes <= fs_info->sectorsize * 4) {
2001 if (ctl->free_extents * 2 <= ctl->extents_thresh)
2002 return false;
2003 } else {
2004 return false;
2005 }
2006 }
2007
2008 /*
2009 * The original block groups from mkfs can be really small, like 8
2010 * megabytes, so don't bother with a bitmap for those entries. However
2011 * some block groups can be smaller than what a bitmap would cover but
2012 * are still large enough that they could overflow the 32k memory limit,
2013 * so allow those block groups to still be allowed to have a bitmap
2014 * entry.
2015 */
2016 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
2017 return false;
2018
2019 return true;
2020 }
2021
2022 static const struct btrfs_free_space_op free_space_op = {
2023 .recalc_thresholds = recalculate_thresholds,
2024 .use_bitmap = use_bitmap,
2025 };
2026
2027 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2028 struct btrfs_free_space *info)
2029 {
2030 struct btrfs_free_space *bitmap_info;
2031 struct btrfs_block_group_cache *block_group = NULL;
2032 int added = 0;
2033 u64 bytes, offset, bytes_added;
2034 int ret;
2035
2036 bytes = info->bytes;
2037 offset = info->offset;
2038
2039 if (!ctl->op->use_bitmap(ctl, info))
2040 return 0;
2041
2042 if (ctl->op == &free_space_op)
2043 block_group = ctl->private;
2044 again:
2045 /*
2046 * Since we link bitmaps right into the cluster we need to see if we
2047 * have a cluster here, and if so and it has our bitmap we need to add
2048 * the free space to that bitmap.
2049 */
2050 if (block_group && !list_empty(&block_group->cluster_list)) {
2051 struct btrfs_free_cluster *cluster;
2052 struct rb_node *node;
2053 struct btrfs_free_space *entry;
2054
2055 cluster = list_entry(block_group->cluster_list.next,
2056 struct btrfs_free_cluster,
2057 block_group_list);
2058 spin_lock(&cluster->lock);
2059 node = rb_first(&cluster->root);
2060 if (!node) {
2061 spin_unlock(&cluster->lock);
2062 goto no_cluster_bitmap;
2063 }
2064
2065 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2066 if (!entry->bitmap) {
2067 spin_unlock(&cluster->lock);
2068 goto no_cluster_bitmap;
2069 }
2070
2071 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2072 bytes_added = add_bytes_to_bitmap(ctl, entry,
2073 offset, bytes);
2074 bytes -= bytes_added;
2075 offset += bytes_added;
2076 }
2077 spin_unlock(&cluster->lock);
2078 if (!bytes) {
2079 ret = 1;
2080 goto out;
2081 }
2082 }
2083
2084 no_cluster_bitmap:
2085 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2086 1, 0);
2087 if (!bitmap_info) {
2088 ASSERT(added == 0);
2089 goto new_bitmap;
2090 }
2091
2092 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
2093 bytes -= bytes_added;
2094 offset += bytes_added;
2095 added = 0;
2096
2097 if (!bytes) {
2098 ret = 1;
2099 goto out;
2100 } else
2101 goto again;
2102
2103 new_bitmap:
2104 if (info && info->bitmap) {
2105 add_new_bitmap(ctl, info, offset);
2106 added = 1;
2107 info = NULL;
2108 goto again;
2109 } else {
2110 spin_unlock(&ctl->tree_lock);
2111
2112 /* no pre-allocated info, allocate a new one */
2113 if (!info) {
2114 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2115 GFP_NOFS);
2116 if (!info) {
2117 spin_lock(&ctl->tree_lock);
2118 ret = -ENOMEM;
2119 goto out;
2120 }
2121 }
2122
2123 /* allocate the bitmap */
2124 info->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
2125 spin_lock(&ctl->tree_lock);
2126 if (!info->bitmap) {
2127 ret = -ENOMEM;
2128 goto out;
2129 }
2130 goto again;
2131 }
2132
2133 out:
2134 if (info) {
2135 if (info->bitmap)
2136 kfree(info->bitmap);
2137 kmem_cache_free(btrfs_free_space_cachep, info);
2138 }
2139
2140 return ret;
2141 }
2142
2143 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2144 struct btrfs_free_space *info, bool update_stat)
2145 {
2146 struct btrfs_free_space *left_info;
2147 struct btrfs_free_space *right_info;
2148 bool merged = false;
2149 u64 offset = info->offset;
2150 u64 bytes = info->bytes;
2151
2152 /*
2153 * first we want to see if there is free space adjacent to the range we
2154 * are adding, if there is remove that struct and add a new one to
2155 * cover the entire range
2156 */
2157 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2158 if (right_info && rb_prev(&right_info->offset_index))
2159 left_info = rb_entry(rb_prev(&right_info->offset_index),
2160 struct btrfs_free_space, offset_index);
2161 else
2162 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2163
2164 if (right_info && !right_info->bitmap) {
2165 if (update_stat)
2166 unlink_free_space(ctl, right_info);
2167 else
2168 __unlink_free_space(ctl, right_info);
2169 info->bytes += right_info->bytes;
2170 kmem_cache_free(btrfs_free_space_cachep, right_info);
2171 merged = true;
2172 }
2173
2174 if (left_info && !left_info->bitmap &&
2175 left_info->offset + left_info->bytes == offset) {
2176 if (update_stat)
2177 unlink_free_space(ctl, left_info);
2178 else
2179 __unlink_free_space(ctl, left_info);
2180 info->offset = left_info->offset;
2181 info->bytes += left_info->bytes;
2182 kmem_cache_free(btrfs_free_space_cachep, left_info);
2183 merged = true;
2184 }
2185
2186 return merged;
2187 }
2188
2189 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2190 struct btrfs_free_space *info,
2191 bool update_stat)
2192 {
2193 struct btrfs_free_space *bitmap;
2194 unsigned long i;
2195 unsigned long j;
2196 const u64 end = info->offset + info->bytes;
2197 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2198 u64 bytes;
2199
2200 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2201 if (!bitmap)
2202 return false;
2203
2204 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2205 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2206 if (j == i)
2207 return false;
2208 bytes = (j - i) * ctl->unit;
2209 info->bytes += bytes;
2210
2211 if (update_stat)
2212 bitmap_clear_bits(ctl, bitmap, end, bytes);
2213 else
2214 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2215
2216 if (!bitmap->bytes)
2217 free_bitmap(ctl, bitmap);
2218
2219 return true;
2220 }
2221
2222 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2223 struct btrfs_free_space *info,
2224 bool update_stat)
2225 {
2226 struct btrfs_free_space *bitmap;
2227 u64 bitmap_offset;
2228 unsigned long i;
2229 unsigned long j;
2230 unsigned long prev_j;
2231 u64 bytes;
2232
2233 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2234 /* If we're on a boundary, try the previous logical bitmap. */
2235 if (bitmap_offset == info->offset) {
2236 if (info->offset == 0)
2237 return false;
2238 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2239 }
2240
2241 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2242 if (!bitmap)
2243 return false;
2244
2245 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2246 j = 0;
2247 prev_j = (unsigned long)-1;
2248 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2249 if (j > i)
2250 break;
2251 prev_j = j;
2252 }
2253 if (prev_j == i)
2254 return false;
2255
2256 if (prev_j == (unsigned long)-1)
2257 bytes = (i + 1) * ctl->unit;
2258 else
2259 bytes = (i - prev_j) * ctl->unit;
2260
2261 info->offset -= bytes;
2262 info->bytes += bytes;
2263
2264 if (update_stat)
2265 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2266 else
2267 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2268
2269 if (!bitmap->bytes)
2270 free_bitmap(ctl, bitmap);
2271
2272 return true;
2273 }
2274
2275 /*
2276 * We prefer always to allocate from extent entries, both for clustered and
2277 * non-clustered allocation requests. So when attempting to add a new extent
2278 * entry, try to see if there's adjacent free space in bitmap entries, and if
2279 * there is, migrate that space from the bitmaps to the extent.
2280 * Like this we get better chances of satisfying space allocation requests
2281 * because we attempt to satisfy them based on a single cache entry, and never
2282 * on 2 or more entries - even if the entries represent a contiguous free space
2283 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2284 * ends).
2285 */
2286 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2287 struct btrfs_free_space *info,
2288 bool update_stat)
2289 {
2290 /*
2291 * Only work with disconnected entries, as we can change their offset,
2292 * and must be extent entries.
2293 */
2294 ASSERT(!info->bitmap);
2295 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2296
2297 if (ctl->total_bitmaps > 0) {
2298 bool stole_end;
2299 bool stole_front = false;
2300
2301 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2302 if (ctl->total_bitmaps > 0)
2303 stole_front = steal_from_bitmap_to_front(ctl, info,
2304 update_stat);
2305
2306 if (stole_end || stole_front)
2307 try_merge_free_space(ctl, info, update_stat);
2308 }
2309 }
2310
2311 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
2312 struct btrfs_free_space_ctl *ctl,
2313 u64 offset, u64 bytes)
2314 {
2315 struct btrfs_free_space *info;
2316 int ret = 0;
2317
2318 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2319 if (!info)
2320 return -ENOMEM;
2321
2322 info->offset = offset;
2323 info->bytes = bytes;
2324 RB_CLEAR_NODE(&info->offset_index);
2325
2326 spin_lock(&ctl->tree_lock);
2327
2328 if (try_merge_free_space(ctl, info, true))
2329 goto link;
2330
2331 /*
2332 * There was no extent directly to the left or right of this new
2333 * extent then we know we're going to have to allocate a new extent, so
2334 * before we do that see if we need to drop this into a bitmap
2335 */
2336 ret = insert_into_bitmap(ctl, info);
2337 if (ret < 0) {
2338 goto out;
2339 } else if (ret) {
2340 ret = 0;
2341 goto out;
2342 }
2343 link:
2344 /*
2345 * Only steal free space from adjacent bitmaps if we're sure we're not
2346 * going to add the new free space to existing bitmap entries - because
2347 * that would mean unnecessary work that would be reverted. Therefore
2348 * attempt to steal space from bitmaps if we're adding an extent entry.
2349 */
2350 steal_from_bitmap(ctl, info, true);
2351
2352 ret = link_free_space(ctl, info);
2353 if (ret)
2354 kmem_cache_free(btrfs_free_space_cachep, info);
2355 out:
2356 spin_unlock(&ctl->tree_lock);
2357
2358 if (ret) {
2359 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2360 ASSERT(ret != -EEXIST);
2361 }
2362
2363 return ret;
2364 }
2365
2366 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2367 u64 offset, u64 bytes)
2368 {
2369 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2370 struct btrfs_free_space *info;
2371 int ret;
2372 bool re_search = false;
2373
2374 spin_lock(&ctl->tree_lock);
2375
2376 again:
2377 ret = 0;
2378 if (!bytes)
2379 goto out_lock;
2380
2381 info = tree_search_offset(ctl, offset, 0, 0);
2382 if (!info) {
2383 /*
2384 * oops didn't find an extent that matched the space we wanted
2385 * to remove, look for a bitmap instead
2386 */
2387 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2388 1, 0);
2389 if (!info) {
2390 /*
2391 * If we found a partial bit of our free space in a
2392 * bitmap but then couldn't find the other part this may
2393 * be a problem, so WARN about it.
2394 */
2395 WARN_ON(re_search);
2396 goto out_lock;
2397 }
2398 }
2399
2400 re_search = false;
2401 if (!info->bitmap) {
2402 unlink_free_space(ctl, info);
2403 if (offset == info->offset) {
2404 u64 to_free = min(bytes, info->bytes);
2405
2406 info->bytes -= to_free;
2407 info->offset += to_free;
2408 if (info->bytes) {
2409 ret = link_free_space(ctl, info);
2410 WARN_ON(ret);
2411 } else {
2412 kmem_cache_free(btrfs_free_space_cachep, info);
2413 }
2414
2415 offset += to_free;
2416 bytes -= to_free;
2417 goto again;
2418 } else {
2419 u64 old_end = info->bytes + info->offset;
2420
2421 info->bytes = offset - info->offset;
2422 ret = link_free_space(ctl, info);
2423 WARN_ON(ret);
2424 if (ret)
2425 goto out_lock;
2426
2427 /* Not enough bytes in this entry to satisfy us */
2428 if (old_end < offset + bytes) {
2429 bytes -= old_end - offset;
2430 offset = old_end;
2431 goto again;
2432 } else if (old_end == offset + bytes) {
2433 /* all done */
2434 goto out_lock;
2435 }
2436 spin_unlock(&ctl->tree_lock);
2437
2438 ret = btrfs_add_free_space(block_group, offset + bytes,
2439 old_end - (offset + bytes));
2440 WARN_ON(ret);
2441 goto out;
2442 }
2443 }
2444
2445 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2446 if (ret == -EAGAIN) {
2447 re_search = true;
2448 goto again;
2449 }
2450 out_lock:
2451 spin_unlock(&ctl->tree_lock);
2452 out:
2453 return ret;
2454 }
2455
2456 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2457 u64 bytes)
2458 {
2459 struct btrfs_fs_info *fs_info = block_group->fs_info;
2460 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2461 struct btrfs_free_space *info;
2462 struct rb_node *n;
2463 int count = 0;
2464
2465 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2466 info = rb_entry(n, struct btrfs_free_space, offset_index);
2467 if (info->bytes >= bytes && !block_group->ro)
2468 count++;
2469 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2470 info->offset, info->bytes,
2471 (info->bitmap) ? "yes" : "no");
2472 }
2473 btrfs_info(fs_info, "block group has cluster?: %s",
2474 list_empty(&block_group->cluster_list) ? "no" : "yes");
2475 btrfs_info(fs_info,
2476 "%d blocks of free space at or bigger than bytes is", count);
2477 }
2478
2479 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2480 {
2481 struct btrfs_fs_info *fs_info = block_group->fs_info;
2482 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2483
2484 spin_lock_init(&ctl->tree_lock);
2485 ctl->unit = fs_info->sectorsize;
2486 ctl->start = block_group->key.objectid;
2487 ctl->private = block_group;
2488 ctl->op = &free_space_op;
2489 INIT_LIST_HEAD(&ctl->trimming_ranges);
2490 mutex_init(&ctl->cache_writeout_mutex);
2491
2492 /*
2493 * we only want to have 32k of ram per block group for keeping
2494 * track of free space, and if we pass 1/2 of that we want to
2495 * start converting things over to using bitmaps
2496 */
2497 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2498 }
2499
2500 /*
2501 * for a given cluster, put all of its extents back into the free
2502 * space cache. If the block group passed doesn't match the block group
2503 * pointed to by the cluster, someone else raced in and freed the
2504 * cluster already. In that case, we just return without changing anything
2505 */
2506 static int
2507 __btrfs_return_cluster_to_free_space(
2508 struct btrfs_block_group_cache *block_group,
2509 struct btrfs_free_cluster *cluster)
2510 {
2511 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2512 struct btrfs_free_space *entry;
2513 struct rb_node *node;
2514
2515 spin_lock(&cluster->lock);
2516 if (cluster->block_group != block_group)
2517 goto out;
2518
2519 cluster->block_group = NULL;
2520 cluster->window_start = 0;
2521 list_del_init(&cluster->block_group_list);
2522
2523 node = rb_first(&cluster->root);
2524 while (node) {
2525 bool bitmap;
2526
2527 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2528 node = rb_next(&entry->offset_index);
2529 rb_erase(&entry->offset_index, &cluster->root);
2530 RB_CLEAR_NODE(&entry->offset_index);
2531
2532 bitmap = (entry->bitmap != NULL);
2533 if (!bitmap) {
2534 try_merge_free_space(ctl, entry, false);
2535 steal_from_bitmap(ctl, entry, false);
2536 }
2537 tree_insert_offset(&ctl->free_space_offset,
2538 entry->offset, &entry->offset_index, bitmap);
2539 }
2540 cluster->root = RB_ROOT;
2541
2542 out:
2543 spin_unlock(&cluster->lock);
2544 btrfs_put_block_group(block_group);
2545 return 0;
2546 }
2547
2548 static void __btrfs_remove_free_space_cache_locked(
2549 struct btrfs_free_space_ctl *ctl)
2550 {
2551 struct btrfs_free_space *info;
2552 struct rb_node *node;
2553
2554 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2555 info = rb_entry(node, struct btrfs_free_space, offset_index);
2556 if (!info->bitmap) {
2557 unlink_free_space(ctl, info);
2558 kmem_cache_free(btrfs_free_space_cachep, info);
2559 } else {
2560 free_bitmap(ctl, info);
2561 }
2562
2563 cond_resched_lock(&ctl->tree_lock);
2564 }
2565 }
2566
2567 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2568 {
2569 spin_lock(&ctl->tree_lock);
2570 __btrfs_remove_free_space_cache_locked(ctl);
2571 spin_unlock(&ctl->tree_lock);
2572 }
2573
2574 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2575 {
2576 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2577 struct btrfs_free_cluster *cluster;
2578 struct list_head *head;
2579
2580 spin_lock(&ctl->tree_lock);
2581 while ((head = block_group->cluster_list.next) !=
2582 &block_group->cluster_list) {
2583 cluster = list_entry(head, struct btrfs_free_cluster,
2584 block_group_list);
2585
2586 WARN_ON(cluster->block_group != block_group);
2587 __btrfs_return_cluster_to_free_space(block_group, cluster);
2588
2589 cond_resched_lock(&ctl->tree_lock);
2590 }
2591 __btrfs_remove_free_space_cache_locked(ctl);
2592 spin_unlock(&ctl->tree_lock);
2593
2594 }
2595
2596 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2597 u64 offset, u64 bytes, u64 empty_size,
2598 u64 *max_extent_size)
2599 {
2600 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2601 struct btrfs_free_space *entry = NULL;
2602 u64 bytes_search = bytes + empty_size;
2603 u64 ret = 0;
2604 u64 align_gap = 0;
2605 u64 align_gap_len = 0;
2606
2607 spin_lock(&ctl->tree_lock);
2608 entry = find_free_space(ctl, &offset, &bytes_search,
2609 block_group->full_stripe_len, max_extent_size);
2610 if (!entry)
2611 goto out;
2612
2613 ret = offset;
2614 if (entry->bitmap) {
2615 bitmap_clear_bits(ctl, entry, offset, bytes);
2616 if (!entry->bytes)
2617 free_bitmap(ctl, entry);
2618 } else {
2619 unlink_free_space(ctl, entry);
2620 align_gap_len = offset - entry->offset;
2621 align_gap = entry->offset;
2622
2623 entry->offset = offset + bytes;
2624 WARN_ON(entry->bytes < bytes + align_gap_len);
2625
2626 entry->bytes -= bytes + align_gap_len;
2627 if (!entry->bytes)
2628 kmem_cache_free(btrfs_free_space_cachep, entry);
2629 else
2630 link_free_space(ctl, entry);
2631 }
2632 out:
2633 spin_unlock(&ctl->tree_lock);
2634
2635 if (align_gap_len)
2636 __btrfs_add_free_space(block_group->fs_info, ctl,
2637 align_gap, align_gap_len);
2638 return ret;
2639 }
2640
2641 /*
2642 * given a cluster, put all of its extents back into the free space
2643 * cache. If a block group is passed, this function will only free
2644 * a cluster that belongs to the passed block group.
2645 *
2646 * Otherwise, it'll get a reference on the block group pointed to by the
2647 * cluster and remove the cluster from it.
2648 */
2649 int btrfs_return_cluster_to_free_space(
2650 struct btrfs_block_group_cache *block_group,
2651 struct btrfs_free_cluster *cluster)
2652 {
2653 struct btrfs_free_space_ctl *ctl;
2654 int ret;
2655
2656 /* first, get a safe pointer to the block group */
2657 spin_lock(&cluster->lock);
2658 if (!block_group) {
2659 block_group = cluster->block_group;
2660 if (!block_group) {
2661 spin_unlock(&cluster->lock);
2662 return 0;
2663 }
2664 } else if (cluster->block_group != block_group) {
2665 /* someone else has already freed it don't redo their work */
2666 spin_unlock(&cluster->lock);
2667 return 0;
2668 }
2669 atomic_inc(&block_group->count);
2670 spin_unlock(&cluster->lock);
2671
2672 ctl = block_group->free_space_ctl;
2673
2674 /* now return any extents the cluster had on it */
2675 spin_lock(&ctl->tree_lock);
2676 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2677 spin_unlock(&ctl->tree_lock);
2678
2679 /* finally drop our ref */
2680 btrfs_put_block_group(block_group);
2681 return ret;
2682 }
2683
2684 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2685 struct btrfs_free_cluster *cluster,
2686 struct btrfs_free_space *entry,
2687 u64 bytes, u64 min_start,
2688 u64 *max_extent_size)
2689 {
2690 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2691 int err;
2692 u64 search_start = cluster->window_start;
2693 u64 search_bytes = bytes;
2694 u64 ret = 0;
2695
2696 search_start = min_start;
2697 search_bytes = bytes;
2698
2699 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2700 if (err) {
2701 if (search_bytes > *max_extent_size)
2702 *max_extent_size = search_bytes;
2703 return 0;
2704 }
2705
2706 ret = search_start;
2707 __bitmap_clear_bits(ctl, entry, ret, bytes);
2708
2709 return ret;
2710 }
2711
2712 /*
2713 * given a cluster, try to allocate 'bytes' from it, returns 0
2714 * if it couldn't find anything suitably large, or a logical disk offset
2715 * if things worked out
2716 */
2717 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2718 struct btrfs_free_cluster *cluster, u64 bytes,
2719 u64 min_start, u64 *max_extent_size)
2720 {
2721 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2722 struct btrfs_free_space *entry = NULL;
2723 struct rb_node *node;
2724 u64 ret = 0;
2725
2726 spin_lock(&cluster->lock);
2727 if (bytes > cluster->max_size)
2728 goto out;
2729
2730 if (cluster->block_group != block_group)
2731 goto out;
2732
2733 node = rb_first(&cluster->root);
2734 if (!node)
2735 goto out;
2736
2737 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2738 while (1) {
2739 if (entry->bytes < bytes && entry->bytes > *max_extent_size)
2740 *max_extent_size = entry->bytes;
2741
2742 if (entry->bytes < bytes ||
2743 (!entry->bitmap && entry->offset < min_start)) {
2744 node = rb_next(&entry->offset_index);
2745 if (!node)
2746 break;
2747 entry = rb_entry(node, struct btrfs_free_space,
2748 offset_index);
2749 continue;
2750 }
2751
2752 if (entry->bitmap) {
2753 ret = btrfs_alloc_from_bitmap(block_group,
2754 cluster, entry, bytes,
2755 cluster->window_start,
2756 max_extent_size);
2757 if (ret == 0) {
2758 node = rb_next(&entry->offset_index);
2759 if (!node)
2760 break;
2761 entry = rb_entry(node, struct btrfs_free_space,
2762 offset_index);
2763 continue;
2764 }
2765 cluster->window_start += bytes;
2766 } else {
2767 ret = entry->offset;
2768
2769 entry->offset += bytes;
2770 entry->bytes -= bytes;
2771 }
2772
2773 if (entry->bytes == 0)
2774 rb_erase(&entry->offset_index, &cluster->root);
2775 break;
2776 }
2777 out:
2778 spin_unlock(&cluster->lock);
2779
2780 if (!ret)
2781 return 0;
2782
2783 spin_lock(&ctl->tree_lock);
2784
2785 ctl->free_space -= bytes;
2786 if (entry->bytes == 0) {
2787 ctl->free_extents--;
2788 if (entry->bitmap) {
2789 kfree(entry->bitmap);
2790 ctl->total_bitmaps--;
2791 ctl->op->recalc_thresholds(ctl);
2792 }
2793 kmem_cache_free(btrfs_free_space_cachep, entry);
2794 }
2795
2796 spin_unlock(&ctl->tree_lock);
2797
2798 return ret;
2799 }
2800
2801 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2802 struct btrfs_free_space *entry,
2803 struct btrfs_free_cluster *cluster,
2804 u64 offset, u64 bytes,
2805 u64 cont1_bytes, u64 min_bytes)
2806 {
2807 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2808 unsigned long next_zero;
2809 unsigned long i;
2810 unsigned long want_bits;
2811 unsigned long min_bits;
2812 unsigned long found_bits;
2813 unsigned long max_bits = 0;
2814 unsigned long start = 0;
2815 unsigned long total_found = 0;
2816 int ret;
2817
2818 i = offset_to_bit(entry->offset, ctl->unit,
2819 max_t(u64, offset, entry->offset));
2820 want_bits = bytes_to_bits(bytes, ctl->unit);
2821 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2822
2823 /*
2824 * Don't bother looking for a cluster in this bitmap if it's heavily
2825 * fragmented.
2826 */
2827 if (entry->max_extent_size &&
2828 entry->max_extent_size < cont1_bytes)
2829 return -ENOSPC;
2830 again:
2831 found_bits = 0;
2832 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2833 next_zero = find_next_zero_bit(entry->bitmap,
2834 BITS_PER_BITMAP, i);
2835 if (next_zero - i >= min_bits) {
2836 found_bits = next_zero - i;
2837 if (found_bits > max_bits)
2838 max_bits = found_bits;
2839 break;
2840 }
2841 if (next_zero - i > max_bits)
2842 max_bits = next_zero - i;
2843 i = next_zero;
2844 }
2845
2846 if (!found_bits) {
2847 entry->max_extent_size = (u64)max_bits * ctl->unit;
2848 return -ENOSPC;
2849 }
2850
2851 if (!total_found) {
2852 start = i;
2853 cluster->max_size = 0;
2854 }
2855
2856 total_found += found_bits;
2857
2858 if (cluster->max_size < found_bits * ctl->unit)
2859 cluster->max_size = found_bits * ctl->unit;
2860
2861 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2862 i = next_zero + 1;
2863 goto again;
2864 }
2865
2866 cluster->window_start = start * ctl->unit + entry->offset;
2867 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2868 ret = tree_insert_offset(&cluster->root, entry->offset,
2869 &entry->offset_index, 1);
2870 ASSERT(!ret); /* -EEXIST; Logic error */
2871
2872 trace_btrfs_setup_cluster(block_group, cluster,
2873 total_found * ctl->unit, 1);
2874 return 0;
2875 }
2876
2877 /*
2878 * This searches the block group for just extents to fill the cluster with.
2879 * Try to find a cluster with at least bytes total bytes, at least one
2880 * extent of cont1_bytes, and other clusters of at least min_bytes.
2881 */
2882 static noinline int
2883 setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2884 struct btrfs_free_cluster *cluster,
2885 struct list_head *bitmaps, u64 offset, u64 bytes,
2886 u64 cont1_bytes, u64 min_bytes)
2887 {
2888 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2889 struct btrfs_free_space *first = NULL;
2890 struct btrfs_free_space *entry = NULL;
2891 struct btrfs_free_space *last;
2892 struct rb_node *node;
2893 u64 window_free;
2894 u64 max_extent;
2895 u64 total_size = 0;
2896
2897 entry = tree_search_offset(ctl, offset, 0, 1);
2898 if (!entry)
2899 return -ENOSPC;
2900
2901 /*
2902 * We don't want bitmaps, so just move along until we find a normal
2903 * extent entry.
2904 */
2905 while (entry->bitmap || entry->bytes < min_bytes) {
2906 if (entry->bitmap && list_empty(&entry->list))
2907 list_add_tail(&entry->list, bitmaps);
2908 node = rb_next(&entry->offset_index);
2909 if (!node)
2910 return -ENOSPC;
2911 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2912 }
2913
2914 window_free = entry->bytes;
2915 max_extent = entry->bytes;
2916 first = entry;
2917 last = entry;
2918
2919 for (node = rb_next(&entry->offset_index); node;
2920 node = rb_next(&entry->offset_index)) {
2921 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2922
2923 if (entry->bitmap) {
2924 if (list_empty(&entry->list))
2925 list_add_tail(&entry->list, bitmaps);
2926 continue;
2927 }
2928
2929 if (entry->bytes < min_bytes)
2930 continue;
2931
2932 last = entry;
2933 window_free += entry->bytes;
2934 if (entry->bytes > max_extent)
2935 max_extent = entry->bytes;
2936 }
2937
2938 if (window_free < bytes || max_extent < cont1_bytes)
2939 return -ENOSPC;
2940
2941 cluster->window_start = first->offset;
2942
2943 node = &first->offset_index;
2944
2945 /*
2946 * now we've found our entries, pull them out of the free space
2947 * cache and put them into the cluster rbtree
2948 */
2949 do {
2950 int ret;
2951
2952 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2953 node = rb_next(&entry->offset_index);
2954 if (entry->bitmap || entry->bytes < min_bytes)
2955 continue;
2956
2957 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2958 ret = tree_insert_offset(&cluster->root, entry->offset,
2959 &entry->offset_index, 0);
2960 total_size += entry->bytes;
2961 ASSERT(!ret); /* -EEXIST; Logic error */
2962 } while (node && entry != last);
2963
2964 cluster->max_size = max_extent;
2965 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2966 return 0;
2967 }
2968
2969 /*
2970 * This specifically looks for bitmaps that may work in the cluster, we assume
2971 * that we have already failed to find extents that will work.
2972 */
2973 static noinline int
2974 setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
2975 struct btrfs_free_cluster *cluster,
2976 struct list_head *bitmaps, u64 offset, u64 bytes,
2977 u64 cont1_bytes, u64 min_bytes)
2978 {
2979 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2980 struct btrfs_free_space *entry = NULL;
2981 int ret = -ENOSPC;
2982 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
2983
2984 if (ctl->total_bitmaps == 0)
2985 return -ENOSPC;
2986
2987 /*
2988 * The bitmap that covers offset won't be in the list unless offset
2989 * is just its start offset.
2990 */
2991 if (!list_empty(bitmaps))
2992 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
2993
2994 if (!entry || entry->offset != bitmap_offset) {
2995 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
2996 if (entry && list_empty(&entry->list))
2997 list_add(&entry->list, bitmaps);
2998 }
2999
3000 list_for_each_entry(entry, bitmaps, list) {
3001 if (entry->bytes < bytes)
3002 continue;
3003 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3004 bytes, cont1_bytes, min_bytes);
3005 if (!ret)
3006 return 0;
3007 }
3008
3009 /*
3010 * The bitmaps list has all the bitmaps that record free space
3011 * starting after offset, so no more search is required.
3012 */
3013 return -ENOSPC;
3014 }
3015
3016 /*
3017 * here we try to find a cluster of blocks in a block group. The goal
3018 * is to find at least bytes+empty_size.
3019 * We might not find them all in one contiguous area.
3020 *
3021 * returns zero and sets up cluster if things worked out, otherwise
3022 * it returns -enospc
3023 */
3024 int btrfs_find_space_cluster(struct btrfs_fs_info *fs_info,
3025 struct btrfs_block_group_cache *block_group,
3026 struct btrfs_free_cluster *cluster,
3027 u64 offset, u64 bytes, u64 empty_size)
3028 {
3029 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3030 struct btrfs_free_space *entry, *tmp;
3031 LIST_HEAD(bitmaps);
3032 u64 min_bytes;
3033 u64 cont1_bytes;
3034 int ret;
3035
3036 /*
3037 * Choose the minimum extent size we'll require for this
3038 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3039 * For metadata, allow allocates with smaller extents. For
3040 * data, keep it dense.
3041 */
3042 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3043 cont1_bytes = min_bytes = bytes + empty_size;
3044 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3045 cont1_bytes = bytes;
3046 min_bytes = fs_info->sectorsize;
3047 } else {
3048 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3049 min_bytes = fs_info->sectorsize;
3050 }
3051
3052 spin_lock(&ctl->tree_lock);
3053
3054 /*
3055 * If we know we don't have enough space to make a cluster don't even
3056 * bother doing all the work to try and find one.
3057 */
3058 if (ctl->free_space < bytes) {
3059 spin_unlock(&ctl->tree_lock);
3060 return -ENOSPC;
3061 }
3062
3063 spin_lock(&cluster->lock);
3064
3065 /* someone already found a cluster, hooray */
3066 if (cluster->block_group) {
3067 ret = 0;
3068 goto out;
3069 }
3070
3071 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3072 min_bytes);
3073
3074 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3075 bytes + empty_size,
3076 cont1_bytes, min_bytes);
3077 if (ret)
3078 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3079 offset, bytes + empty_size,
3080 cont1_bytes, min_bytes);
3081
3082 /* Clear our temporary list */
3083 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3084 list_del_init(&entry->list);
3085
3086 if (!ret) {
3087 atomic_inc(&block_group->count);
3088 list_add_tail(&cluster->block_group_list,
3089 &block_group->cluster_list);
3090 cluster->block_group = block_group;
3091 } else {
3092 trace_btrfs_failed_cluster_setup(block_group);
3093 }
3094 out:
3095 spin_unlock(&cluster->lock);
3096 spin_unlock(&ctl->tree_lock);
3097
3098 return ret;
3099 }
3100
3101 /*
3102 * simple code to zero out a cluster
3103 */
3104 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3105 {
3106 spin_lock_init(&cluster->lock);
3107 spin_lock_init(&cluster->refill_lock);
3108 cluster->root = RB_ROOT;
3109 cluster->max_size = 0;
3110 cluster->fragmented = false;
3111 INIT_LIST_HEAD(&cluster->block_group_list);
3112 cluster->block_group = NULL;
3113 }
3114
3115 static int do_trimming(struct btrfs_block_group_cache *block_group,
3116 u64 *total_trimmed, u64 start, u64 bytes,
3117 u64 reserved_start, u64 reserved_bytes,
3118 struct btrfs_trim_range *trim_entry)
3119 {
3120 struct btrfs_space_info *space_info = block_group->space_info;
3121 struct btrfs_fs_info *fs_info = block_group->fs_info;
3122 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3123 int ret;
3124 int update = 0;
3125 u64 trimmed = 0;
3126
3127 spin_lock(&space_info->lock);
3128 spin_lock(&block_group->lock);
3129 if (!block_group->ro) {
3130 block_group->reserved += reserved_bytes;
3131 space_info->bytes_reserved += reserved_bytes;
3132 update = 1;
3133 }
3134 spin_unlock(&block_group->lock);
3135 spin_unlock(&space_info->lock);
3136
3137 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3138 if (!ret)
3139 *total_trimmed += trimmed;
3140
3141 mutex_lock(&ctl->cache_writeout_mutex);
3142 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
3143 list_del(&trim_entry->list);
3144 mutex_unlock(&ctl->cache_writeout_mutex);
3145
3146 if (update) {
3147 spin_lock(&space_info->lock);
3148 spin_lock(&block_group->lock);
3149 if (block_group->ro)
3150 space_info->bytes_readonly += reserved_bytes;
3151 block_group->reserved -= reserved_bytes;
3152 space_info->bytes_reserved -= reserved_bytes;
3153 spin_unlock(&space_info->lock);
3154 spin_unlock(&block_group->lock);
3155 }
3156
3157 return ret;
3158 }
3159
3160 static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
3161 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3162 {
3163 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3164 struct btrfs_free_space *entry;
3165 struct rb_node *node;
3166 int ret = 0;
3167 u64 extent_start;
3168 u64 extent_bytes;
3169 u64 bytes;
3170
3171 while (start < end) {
3172 struct btrfs_trim_range trim_entry;
3173
3174 mutex_lock(&ctl->cache_writeout_mutex);
3175 spin_lock(&ctl->tree_lock);
3176
3177 if (ctl->free_space < minlen) {
3178 spin_unlock(&ctl->tree_lock);
3179 mutex_unlock(&ctl->cache_writeout_mutex);
3180 break;
3181 }
3182
3183 entry = tree_search_offset(ctl, start, 0, 1);
3184 if (!entry) {
3185 spin_unlock(&ctl->tree_lock);
3186 mutex_unlock(&ctl->cache_writeout_mutex);
3187 break;
3188 }
3189
3190 /* skip bitmaps */
3191 while (entry->bitmap) {
3192 node = rb_next(&entry->offset_index);
3193 if (!node) {
3194 spin_unlock(&ctl->tree_lock);
3195 mutex_unlock(&ctl->cache_writeout_mutex);
3196 goto out;
3197 }
3198 entry = rb_entry(node, struct btrfs_free_space,
3199 offset_index);
3200 }
3201
3202 if (entry->offset >= end) {
3203 spin_unlock(&ctl->tree_lock);
3204 mutex_unlock(&ctl->cache_writeout_mutex);
3205 break;
3206 }
3207
3208 extent_start = entry->offset;
3209 extent_bytes = entry->bytes;
3210 start = max(start, extent_start);
3211 bytes = min(extent_start + extent_bytes, end) - start;
3212 if (bytes < minlen) {
3213 spin_unlock(&ctl->tree_lock);
3214 mutex_unlock(&ctl->cache_writeout_mutex);
3215 goto next;
3216 }
3217
3218 unlink_free_space(ctl, entry);
3219 kmem_cache_free(btrfs_free_space_cachep, entry);
3220
3221 spin_unlock(&ctl->tree_lock);
3222 trim_entry.start = extent_start;
3223 trim_entry.bytes = extent_bytes;
3224 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3225 mutex_unlock(&ctl->cache_writeout_mutex);
3226
3227 ret = do_trimming(block_group, total_trimmed, start, bytes,
3228 extent_start, extent_bytes, &trim_entry);
3229 if (ret)
3230 break;
3231 next:
3232 start += bytes;
3233
3234 if (fatal_signal_pending(current)) {
3235 ret = -ERESTARTSYS;
3236 break;
3237 }
3238
3239 cond_resched();
3240 }
3241 out:
3242 return ret;
3243 }
3244
3245 static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
3246 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3247 {
3248 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3249 struct btrfs_free_space *entry;
3250 int ret = 0;
3251 int ret2;
3252 u64 bytes;
3253 u64 offset = offset_to_bitmap(ctl, start);
3254
3255 while (offset < end) {
3256 bool next_bitmap = false;
3257 struct btrfs_trim_range trim_entry;
3258
3259 mutex_lock(&ctl->cache_writeout_mutex);
3260 spin_lock(&ctl->tree_lock);
3261
3262 if (ctl->free_space < minlen) {
3263 spin_unlock(&ctl->tree_lock);
3264 mutex_unlock(&ctl->cache_writeout_mutex);
3265 break;
3266 }
3267
3268 entry = tree_search_offset(ctl, offset, 1, 0);
3269 if (!entry) {
3270 spin_unlock(&ctl->tree_lock);
3271 mutex_unlock(&ctl->cache_writeout_mutex);
3272 next_bitmap = true;
3273 goto next;
3274 }
3275
3276 bytes = minlen;
3277 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3278 if (ret2 || start >= end) {
3279 spin_unlock(&ctl->tree_lock);
3280 mutex_unlock(&ctl->cache_writeout_mutex);
3281 next_bitmap = true;
3282 goto next;
3283 }
3284
3285 bytes = min(bytes, end - start);
3286 if (bytes < minlen) {
3287 spin_unlock(&ctl->tree_lock);
3288 mutex_unlock(&ctl->cache_writeout_mutex);
3289 goto next;
3290 }
3291
3292 bitmap_clear_bits(ctl, entry, start, bytes);
3293 if (entry->bytes == 0)
3294 free_bitmap(ctl, entry);
3295
3296 spin_unlock(&ctl->tree_lock);
3297 trim_entry.start = start;
3298 trim_entry.bytes = bytes;
3299 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3300 mutex_unlock(&ctl->cache_writeout_mutex);
3301
3302 ret = do_trimming(block_group, total_trimmed, start, bytes,
3303 start, bytes, &trim_entry);
3304 if (ret)
3305 break;
3306 next:
3307 if (next_bitmap) {
3308 offset += BITS_PER_BITMAP * ctl->unit;
3309 } else {
3310 start += bytes;
3311 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
3312 offset += BITS_PER_BITMAP * ctl->unit;
3313 }
3314
3315 if (fatal_signal_pending(current)) {
3316 ret = -ERESTARTSYS;
3317 break;
3318 }
3319
3320 cond_resched();
3321 }
3322
3323 return ret;
3324 }
3325
3326 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
3327 {
3328 atomic_inc(&cache->trimming);
3329 }
3330
3331 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
3332 {
3333 struct btrfs_fs_info *fs_info = block_group->fs_info;
3334 struct extent_map_tree *em_tree;
3335 struct extent_map *em;
3336 bool cleanup;
3337
3338 spin_lock(&block_group->lock);
3339 cleanup = (atomic_dec_and_test(&block_group->trimming) &&
3340 block_group->removed);
3341 spin_unlock(&block_group->lock);
3342
3343 if (cleanup) {
3344 mutex_lock(&fs_info->chunk_mutex);
3345 em_tree = &fs_info->mapping_tree.map_tree;
3346 write_lock(&em_tree->lock);
3347 em = lookup_extent_mapping(em_tree, block_group->key.objectid,
3348 1);
3349 BUG_ON(!em); /* logic error, can't happen */
3350 /*
3351 * remove_extent_mapping() will delete us from the pinned_chunks
3352 * list, which is protected by the chunk mutex.
3353 */
3354 remove_extent_mapping(em_tree, em);
3355 write_unlock(&em_tree->lock);
3356 mutex_unlock(&fs_info->chunk_mutex);
3357
3358 /* once for us and once for the tree */
3359 free_extent_map(em);
3360 free_extent_map(em);
3361
3362 /*
3363 * We've left one free space entry and other tasks trimming
3364 * this block group have left 1 entry each one. Free them.
3365 */
3366 __btrfs_remove_free_space_cache(block_group->free_space_ctl);
3367 }
3368 }
3369
3370 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
3371 u64 *trimmed, u64 start, u64 end, u64 minlen)
3372 {
3373 int ret;
3374
3375 *trimmed = 0;
3376
3377 spin_lock(&block_group->lock);
3378 if (block_group->removed) {
3379 spin_unlock(&block_group->lock);
3380 return 0;
3381 }
3382 btrfs_get_block_group_trimming(block_group);
3383 spin_unlock(&block_group->lock);
3384
3385 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
3386 if (ret)
3387 goto out;
3388
3389 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
3390 out:
3391 btrfs_put_block_group_trimming(block_group);
3392 return ret;
3393 }
3394
3395 /*
3396 * Find the left-most item in the cache tree, and then return the
3397 * smallest inode number in the item.
3398 *
3399 * Note: the returned inode number may not be the smallest one in
3400 * the tree, if the left-most item is a bitmap.
3401 */
3402 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3403 {
3404 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3405 struct btrfs_free_space *entry = NULL;
3406 u64 ino = 0;
3407
3408 spin_lock(&ctl->tree_lock);
3409
3410 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3411 goto out;
3412
3413 entry = rb_entry(rb_first(&ctl->free_space_offset),
3414 struct btrfs_free_space, offset_index);
3415
3416 if (!entry->bitmap) {
3417 ino = entry->offset;
3418
3419 unlink_free_space(ctl, entry);
3420 entry->offset++;
3421 entry->bytes--;
3422 if (!entry->bytes)
3423 kmem_cache_free(btrfs_free_space_cachep, entry);
3424 else
3425 link_free_space(ctl, entry);
3426 } else {
3427 u64 offset = 0;
3428 u64 count = 1;
3429 int ret;
3430
3431 ret = search_bitmap(ctl, entry, &offset, &count, true);
3432 /* Logic error; Should be empty if it can't find anything */
3433 ASSERT(!ret);
3434
3435 ino = offset;
3436 bitmap_clear_bits(ctl, entry, offset, 1);
3437 if (entry->bytes == 0)
3438 free_bitmap(ctl, entry);
3439 }
3440 out:
3441 spin_unlock(&ctl->tree_lock);
3442
3443 return ino;
3444 }
3445
3446 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3447 struct btrfs_path *path)
3448 {
3449 struct inode *inode = NULL;
3450
3451 spin_lock(&root->ino_cache_lock);
3452 if (root->ino_cache_inode)
3453 inode = igrab(root->ino_cache_inode);
3454 spin_unlock(&root->ino_cache_lock);
3455 if (inode)
3456 return inode;
3457
3458 inode = __lookup_free_space_inode(root, path, 0);
3459 if (IS_ERR(inode))
3460 return inode;
3461
3462 spin_lock(&root->ino_cache_lock);
3463 if (!btrfs_fs_closing(root->fs_info))
3464 root->ino_cache_inode = igrab(inode);
3465 spin_unlock(&root->ino_cache_lock);
3466
3467 return inode;
3468 }
3469
3470 int create_free_ino_inode(struct btrfs_root *root,
3471 struct btrfs_trans_handle *trans,
3472 struct btrfs_path *path)
3473 {
3474 return __create_free_space_inode(root, trans, path,
3475 BTRFS_FREE_INO_OBJECTID, 0);
3476 }
3477
3478 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3479 {
3480 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3481 struct btrfs_path *path;
3482 struct inode *inode;
3483 int ret = 0;
3484 u64 root_gen = btrfs_root_generation(&root->root_item);
3485
3486 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3487 return 0;
3488
3489 /*
3490 * If we're unmounting then just return, since this does a search on the
3491 * normal root and not the commit root and we could deadlock.
3492 */
3493 if (btrfs_fs_closing(fs_info))
3494 return 0;
3495
3496 path = btrfs_alloc_path();
3497 if (!path)
3498 return 0;
3499
3500 inode = lookup_free_ino_inode(root, path);
3501 if (IS_ERR(inode))
3502 goto out;
3503
3504 if (root_gen != BTRFS_I(inode)->generation)
3505 goto out_put;
3506
3507 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3508
3509 if (ret < 0)
3510 btrfs_err(fs_info,
3511 "failed to load free ino cache for root %llu",
3512 root->root_key.objectid);
3513 out_put:
3514 iput(inode);
3515 out:
3516 btrfs_free_path(path);
3517 return ret;
3518 }
3519
3520 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3521 struct btrfs_trans_handle *trans,
3522 struct btrfs_path *path,
3523 struct inode *inode)
3524 {
3525 struct btrfs_fs_info *fs_info = root->fs_info;
3526 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3527 int ret;
3528 struct btrfs_io_ctl io_ctl;
3529 bool release_metadata = true;
3530
3531 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3532 return 0;
3533
3534 memset(&io_ctl, 0, sizeof(io_ctl));
3535 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
3536 if (!ret) {
3537 /*
3538 * At this point writepages() didn't error out, so our metadata
3539 * reservation is released when the writeback finishes, at
3540 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3541 * with or without an error.
3542 */
3543 release_metadata = false;
3544 ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
3545 }
3546
3547 if (ret) {
3548 if (release_metadata)
3549 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3550 inode->i_size);
3551 #ifdef DEBUG
3552 btrfs_err(fs_info,
3553 "failed to write free ino cache for root %llu",
3554 root->root_key.objectid);
3555 #endif
3556 }
3557
3558 return ret;
3559 }
3560
3561 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3562 /*
3563 * Use this if you need to make a bitmap or extent entry specifically, it
3564 * doesn't do any of the merging that add_free_space does, this acts a lot like
3565 * how the free space cache loading stuff works, so you can get really weird
3566 * configurations.
3567 */
3568 int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3569 u64 offset, u64 bytes, bool bitmap)
3570 {
3571 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3572 struct btrfs_free_space *info = NULL, *bitmap_info;
3573 void *map = NULL;
3574 u64 bytes_added;
3575 int ret;
3576
3577 again:
3578 if (!info) {
3579 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3580 if (!info)
3581 return -ENOMEM;
3582 }
3583
3584 if (!bitmap) {
3585 spin_lock(&ctl->tree_lock);
3586 info->offset = offset;
3587 info->bytes = bytes;
3588 info->max_extent_size = 0;
3589 ret = link_free_space(ctl, info);
3590 spin_unlock(&ctl->tree_lock);
3591 if (ret)
3592 kmem_cache_free(btrfs_free_space_cachep, info);
3593 return ret;
3594 }
3595
3596 if (!map) {
3597 map = kzalloc(PAGE_SIZE, GFP_NOFS);
3598 if (!map) {
3599 kmem_cache_free(btrfs_free_space_cachep, info);
3600 return -ENOMEM;
3601 }
3602 }
3603
3604 spin_lock(&ctl->tree_lock);
3605 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3606 1, 0);
3607 if (!bitmap_info) {
3608 info->bitmap = map;
3609 map = NULL;
3610 add_new_bitmap(ctl, info, offset);
3611 bitmap_info = info;
3612 info = NULL;
3613 }
3614
3615 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3616
3617 bytes -= bytes_added;
3618 offset += bytes_added;
3619 spin_unlock(&ctl->tree_lock);
3620
3621 if (bytes)
3622 goto again;
3623
3624 if (info)
3625 kmem_cache_free(btrfs_free_space_cachep, info);
3626 if (map)
3627 kfree(map);
3628 return 0;
3629 }
3630
3631 /*
3632 * Checks to see if the given range is in the free space cache. This is really
3633 * just used to check the absence of space, so if there is free space in the
3634 * range at all we will return 1.
3635 */
3636 int test_check_exists(struct btrfs_block_group_cache *cache,
3637 u64 offset, u64 bytes)
3638 {
3639 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3640 struct btrfs_free_space *info;
3641 int ret = 0;
3642
3643 spin_lock(&ctl->tree_lock);
3644 info = tree_search_offset(ctl, offset, 0, 0);
3645 if (!info) {
3646 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3647 1, 0);
3648 if (!info)
3649 goto out;
3650 }
3651
3652 have_info:
3653 if (info->bitmap) {
3654 u64 bit_off, bit_bytes;
3655 struct rb_node *n;
3656 struct btrfs_free_space *tmp;
3657
3658 bit_off = offset;
3659 bit_bytes = ctl->unit;
3660 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
3661 if (!ret) {
3662 if (bit_off == offset) {
3663 ret = 1;
3664 goto out;
3665 } else if (bit_off > offset &&
3666 offset + bytes > bit_off) {
3667 ret = 1;
3668 goto out;
3669 }
3670 }
3671
3672 n = rb_prev(&info->offset_index);
3673 while (n) {
3674 tmp = rb_entry(n, struct btrfs_free_space,
3675 offset_index);
3676 if (tmp->offset + tmp->bytes < offset)
3677 break;
3678 if (offset + bytes < tmp->offset) {
3679 n = rb_prev(&tmp->offset_index);
3680 continue;
3681 }
3682 info = tmp;
3683 goto have_info;
3684 }
3685
3686 n = rb_next(&info->offset_index);
3687 while (n) {
3688 tmp = rb_entry(n, struct btrfs_free_space,
3689 offset_index);
3690 if (offset + bytes < tmp->offset)
3691 break;
3692 if (tmp->offset + tmp->bytes < offset) {
3693 n = rb_next(&tmp->offset_index);
3694 continue;
3695 }
3696 info = tmp;
3697 goto have_info;
3698 }
3699
3700 ret = 0;
3701 goto out;
3702 }
3703
3704 if (info->offset == offset) {
3705 ret = 1;
3706 goto out;
3707 }
3708
3709 if (offset > info->offset && offset < info->offset + info->bytes)
3710 ret = 1;
3711 out:
3712 spin_unlock(&ctl->tree_lock);
3713 return ret;
3714 }
3715 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Linux with added FPC-III support